]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/net/if_ipsec.c
xnu-4903.241.1.tar.gz
[apple/xnu.git] / bsd / net / if_ipsec.c
index e1aac8335dfade2a1139120ffa5d4f074d92d9cf..22a1441ddba747f442e58e8c6d02bd97ee3dd5b8 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012 Apple Inc. All rights reserved.
+ * Copyright (c) 2012-2018 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 
+
 #include <sys/systm.h>
 #include <sys/kern_control.h>
 #include <net/kpi_protocol.h>
 #include <net/kpi_interface.h>
 #include <sys/socket.h>
+#include <sys/socketvar.h>
 #include <net/if.h>
 #include <net/if_types.h>
 #include <net/bpf.h>
 #include <net/if_ipsec.h>
-#include <libkern/OSMalloc.h>
-#include <libkern/OSAtomic.h>
 #include <sys/mbuf.h>
 #include <sys/sockio.h>
 #include <netinet/in.h>
 #include <sys/kauth.h>
 #include <netinet6/ipsec.h>
 #include <netinet6/ipsec6.h>
+#include <netinet6/esp.h>
+#include <netinet6/esp6.h>
 #include <netinet/ip.h>
 #include <net/flowadv.h>
+#include <net/necp.h>
+#include <netkey/key.h>
+#include <net/pktap.h>
+#include <kern/zalloc.h>
+
+#define IPSEC_NEXUS 0
+
+extern int net_qos_policy_restricted;
+extern int net_qos_policy_restrict_avapps;
 
 /* Kernel Control functions */
+static errno_t ipsec_ctl_bind(kern_ctl_ref kctlref, struct sockaddr_ctl *sac,
+                                                          void **unitinfo);
 static errno_t ipsec_ctl_connect(kern_ctl_ref kctlref, struct sockaddr_ctl *sac,
                                                                  void **unitinfo);
 static errno_t ipsec_ctl_disconnect(kern_ctl_ref kctlref, u_int32_t unit,
@@ -61,166 +74,2213 @@ static errno_t   ipsec_ctl_getopt(kern_ctl_ref kctlref, u_int32_t unit, void *unit
 static errno_t ipsec_ctl_setopt(kern_ctl_ref kctlref, u_int32_t unit, void *unitinfo,
                                                                 int opt, void *data, size_t len);
 
-/* Network Interface functions */
-static void     ipsec_start(ifnet_t    interface);
-static errno_t ipsec_output(ifnet_t interface, mbuf_t data);
-static errno_t ipsec_demux(ifnet_t interface, mbuf_t data, char *frame_header,
-                                                       protocol_family_t *protocol);
-static errno_t ipsec_add_proto(ifnet_t interface, protocol_family_t protocol,
-                                                               const struct ifnet_demux_desc *demux_array,
-                                                               u_int32_t demux_count);
-static errno_t ipsec_del_proto(ifnet_t interface, protocol_family_t protocol);
-static errno_t ipsec_ioctl(ifnet_t interface, u_long cmd, void *data);
-static void            ipsec_detached(ifnet_t interface);
+/* Network Interface functions */
+static void     ipsec_start(ifnet_t    interface);
+static errno_t ipsec_output(ifnet_t interface, mbuf_t data);
+static errno_t ipsec_demux(ifnet_t interface, mbuf_t data, char *frame_header,
+                                                       protocol_family_t *protocol);
+static errno_t ipsec_add_proto(ifnet_t interface, protocol_family_t protocol,
+                                                               const struct ifnet_demux_desc *demux_array,
+                                                               u_int32_t demux_count);
+static errno_t ipsec_del_proto(ifnet_t interface, protocol_family_t protocol);
+static errno_t ipsec_ioctl(ifnet_t interface, u_long cmd, void *data);
+static void            ipsec_detached(ifnet_t interface);
+
+/* Protocol handlers */
+static errno_t ipsec_attach_proto(ifnet_t interface, protocol_family_t proto);
+static errno_t ipsec_proto_input(ifnet_t interface, protocol_family_t protocol,
+                                                                 mbuf_t m, char *frame_header);
+static errno_t ipsec_proto_pre_output(ifnet_t interface, protocol_family_t protocol,
+                                                                         mbuf_t *packet, const struct sockaddr *dest, void *route,
+                                                                         char *frame_type, char *link_layer_dest);
+
+static kern_ctl_ref    ipsec_kctlref;
+static u_int32_t       ipsec_family;
+static lck_attr_t *ipsec_lck_attr;
+static lck_grp_attr_t *ipsec_lck_grp_attr;
+static lck_grp_t *ipsec_lck_grp;
+static lck_mtx_t ipsec_lock;
+
+#if IPSEC_NEXUS
+
+SYSCTL_DECL(_net_ipsec);
+SYSCTL_NODE(_net, OID_AUTO, ipsec, CTLFLAG_RW | CTLFLAG_LOCKED, 0, "IPsec");
+static int if_ipsec_verify_interface_creation = 0;
+SYSCTL_INT(_net_ipsec, OID_AUTO, verify_interface_creation, CTLFLAG_RW | CTLFLAG_LOCKED, &if_ipsec_verify_interface_creation, 0, "");
+
+#define IPSEC_IF_VERIFY(_e)            if (__improbable(if_ipsec_verify_interface_creation)) { VERIFY(_e); }
+
+#define IPSEC_IF_DEFAULT_SLOT_SIZE 2048
+#define IPSEC_IF_DEFAULT_RING_SIZE 64
+#define IPSEC_IF_DEFAULT_TX_FSW_RING_SIZE 64
+#define IPSEC_IF_DEFAULT_RX_FSW_RING_SIZE 128
+#define        IPSEC_IF_DEFAULT_BUF_SEG_SIZE   skmem_usr_buf_seg_size
+
+#define IPSEC_IF_MIN_RING_SIZE 16
+#define IPSEC_IF_MAX_RING_SIZE 1024
+
+#define IPSEC_IF_MIN_SLOT_SIZE 1024
+#define IPSEC_IF_MAX_SLOT_SIZE 4096
+
+static int sysctl_if_ipsec_ring_size SYSCTL_HANDLER_ARGS;
+static int sysctl_if_ipsec_tx_fsw_ring_size SYSCTL_HANDLER_ARGS;
+static int sysctl_if_ipsec_rx_fsw_ring_size SYSCTL_HANDLER_ARGS;
+
+static int if_ipsec_ring_size = IPSEC_IF_DEFAULT_RING_SIZE;
+static int if_ipsec_tx_fsw_ring_size = IPSEC_IF_DEFAULT_TX_FSW_RING_SIZE;
+static int if_ipsec_rx_fsw_ring_size = IPSEC_IF_DEFAULT_RX_FSW_RING_SIZE;
+
+SYSCTL_PROC(_net_ipsec, OID_AUTO, ring_size, CTLTYPE_INT | CTLFLAG_LOCKED | CTLFLAG_RW,
+                       &if_ipsec_ring_size, IPSEC_IF_DEFAULT_RING_SIZE, &sysctl_if_ipsec_ring_size, "I", "");
+SYSCTL_PROC(_net_ipsec, OID_AUTO, tx_fsw_ring_size, CTLTYPE_INT | CTLFLAG_LOCKED | CTLFLAG_RW,
+                       &if_ipsec_tx_fsw_ring_size, IPSEC_IF_DEFAULT_TX_FSW_RING_SIZE, &sysctl_if_ipsec_tx_fsw_ring_size, "I", "");
+SYSCTL_PROC(_net_ipsec, OID_AUTO, rx_fsw_ring_size, CTLTYPE_INT | CTLFLAG_LOCKED | CTLFLAG_RW,
+                       &if_ipsec_rx_fsw_ring_size, IPSEC_IF_DEFAULT_RX_FSW_RING_SIZE, &sysctl_if_ipsec_rx_fsw_ring_size, "I", "");
+
+static errno_t
+ipsec_register_nexus(void);
+
+typedef struct ipsec_nx {
+       uuid_t if_provider;
+       uuid_t if_instance;
+       uuid_t ms_provider;
+       uuid_t ms_instance;
+       uuid_t ms_device;
+       uuid_t ms_host;
+       uuid_t ms_agent;
+} *ipsec_nx_t;
+
+static nexus_controller_t ipsec_ncd;
+static int ipsec_ncd_refcount;
+static uuid_t ipsec_kpipe_uuid;
+
+#endif // IPSEC_NEXUS
+
+/* Control block allocated for each kernel control connection */
+struct ipsec_pcb {
+       TAILQ_ENTRY(ipsec_pcb)  ipsec_chain;
+       kern_ctl_ref            ipsec_ctlref;
+       ifnet_t                         ipsec_ifp;
+       u_int32_t                       ipsec_unit;
+       u_int32_t                       ipsec_unique_id;
+       u_int32_t                       ipsec_flags;
+       u_int32_t                       ipsec_input_frag_size;
+       bool                            ipsec_frag_size_set;
+       int                                     ipsec_ext_ifdata_stats;
+       mbuf_svc_class_t        ipsec_output_service_class;
+       char                            ipsec_if_xname[IFXNAMSIZ];
+       char                            ipsec_unique_name[IFXNAMSIZ];
+       // PCB lock protects state fields, like ipsec_kpipe_enabled
+       decl_lck_rw_data(, ipsec_pcb_lock);
+
+#if IPSEC_NEXUS
+       lck_mtx_t                       ipsec_input_chain_lock;
+       struct mbuf *           ipsec_input_chain;
+       struct mbuf *           ipsec_input_chain_last;
+       // Input chain lock protects the list of input mbufs
+       // The input chain lock must be taken AFTER the PCB lock if both are held
+       struct ipsec_nx         ipsec_nx;
+       int                                     ipsec_kpipe_enabled;
+       uuid_t                          ipsec_kpipe_uuid;
+       void *                          ipsec_kpipe_rxring;
+       void *                          ipsec_kpipe_txring;
+       kern_pbufpool_t                 ipsec_kpipe_pp;
+
+       kern_nexus_t            ipsec_netif_nexus;
+       kern_pbufpool_t                 ipsec_netif_pp;
+       void *                          ipsec_netif_rxring;
+       void *                          ipsec_netif_txring;
+       uint64_t                        ipsec_netif_txring_size;
+
+       u_int32_t                       ipsec_slot_size;
+       u_int32_t                       ipsec_netif_ring_size;
+       u_int32_t                       ipsec_tx_fsw_ring_size;
+       u_int32_t                       ipsec_rx_fsw_ring_size;
+       bool                            ipsec_use_netif;
+       bool                            ipsec_needs_netagent;
+#endif // IPSEC_NEXUS
+};
+
+TAILQ_HEAD(ipsec_list, ipsec_pcb) ipsec_head;
+
+#define        IPSEC_PCB_ZONE_MAX              32
+#define        IPSEC_PCB_ZONE_NAME             "net.if_ipsec"
+
+static unsigned int ipsec_pcb_size;            /* size of zone element */
+static struct zone *ipsec_pcb_zone;            /* zone for ipsec_pcb */
+
+#define IPSECQ_MAXLEN 256
+
+#if IPSEC_NEXUS
+static int
+sysctl_if_ipsec_ring_size SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+       int value = if_ipsec_ring_size;
+
+       int error = sysctl_handle_int(oidp, &value, 0, req);
+       if (error || !req->newptr) {
+               return (error);
+       }
+
+       if (value < IPSEC_IF_MIN_RING_SIZE ||
+               value > IPSEC_IF_MAX_RING_SIZE) {
+               return (EINVAL);
+       }
+
+       if_ipsec_ring_size = value;
+
+       return (0);
+}
+
+static int
+sysctl_if_ipsec_tx_fsw_ring_size SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+       int value = if_ipsec_tx_fsw_ring_size;
+
+       int error = sysctl_handle_int(oidp, &value, 0, req);
+       if (error || !req->newptr) {
+               return (error);
+       }
+
+       if (value < IPSEC_IF_MIN_RING_SIZE ||
+               value > IPSEC_IF_MAX_RING_SIZE) {
+               return (EINVAL);
+       }
+
+       if_ipsec_tx_fsw_ring_size = value;
+
+       return (0);
+}
+
+static int
+sysctl_if_ipsec_rx_fsw_ring_size SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+       int value = if_ipsec_rx_fsw_ring_size;
+
+       int error = sysctl_handle_int(oidp, &value, 0, req);
+       if (error || !req->newptr) {
+               return (error);
+       }
+
+       if (value < IPSEC_IF_MIN_RING_SIZE ||
+               value > IPSEC_IF_MAX_RING_SIZE) {
+               return (EINVAL);
+       }
+
+       if_ipsec_rx_fsw_ring_size = value;
+
+       return (0);
+}
+#endif // IPSEC_NEXUS
+
+errno_t
+ipsec_register_control(void)
+{
+       struct kern_ctl_reg     kern_ctl;
+       errno_t                         result = 0;
+       
+       /* Find a unique value for our interface family */
+       result = mbuf_tag_id_find(IPSEC_CONTROL_NAME, &ipsec_family);
+       if (result != 0) {
+               printf("ipsec_register_control - mbuf_tag_id_find_internal failed: %d\n", result);
+               return result;
+       }
+
+       ipsec_pcb_size = sizeof(struct ipsec_pcb);
+       ipsec_pcb_zone = zinit(ipsec_pcb_size,
+                                                  IPSEC_PCB_ZONE_MAX * ipsec_pcb_size,
+                                                  0, IPSEC_PCB_ZONE_NAME);
+       if (ipsec_pcb_zone == NULL) {
+               printf("ipsec_register_control - zinit(ipsec_pcb) failed");
+               return ENOMEM;
+       }
+
+#if IPSEC_NEXUS
+       ipsec_register_nexus();
+#endif // IPSEC_NEXUS
+
+       TAILQ_INIT(&ipsec_head);
+       
+       bzero(&kern_ctl, sizeof(kern_ctl));
+       strlcpy(kern_ctl.ctl_name, IPSEC_CONTROL_NAME, sizeof(kern_ctl.ctl_name));
+       kern_ctl.ctl_name[sizeof(kern_ctl.ctl_name) - 1] = 0;
+       kern_ctl.ctl_flags = CTL_FLAG_PRIVILEGED; /* Require root */
+       kern_ctl.ctl_sendsize = 64 * 1024;
+       kern_ctl.ctl_recvsize = 64 * 1024;
+       kern_ctl.ctl_bind = ipsec_ctl_bind;
+       kern_ctl.ctl_connect = ipsec_ctl_connect;
+       kern_ctl.ctl_disconnect = ipsec_ctl_disconnect;
+       kern_ctl.ctl_send = ipsec_ctl_send;
+       kern_ctl.ctl_setopt = ipsec_ctl_setopt;
+       kern_ctl.ctl_getopt = ipsec_ctl_getopt;
+       
+       result = ctl_register(&kern_ctl, &ipsec_kctlref);
+       if (result != 0) {
+               printf("ipsec_register_control - ctl_register failed: %d\n", result);
+               return result;
+       }
+       
+       /* Register the protocol plumbers */
+       if ((result = proto_register_plumber(PF_INET, ipsec_family,
+                                                                                ipsec_attach_proto, NULL)) != 0) {
+               printf("ipsec_register_control - proto_register_plumber(PF_INET, %d) failed: %d\n",
+                          ipsec_family, result);
+               ctl_deregister(ipsec_kctlref);
+               return result;
+       }
+       
+       /* Register the protocol plumbers */
+       if ((result = proto_register_plumber(PF_INET6, ipsec_family,
+                                                                                ipsec_attach_proto, NULL)) != 0) {
+               proto_unregister_plumber(PF_INET, ipsec_family);
+               ctl_deregister(ipsec_kctlref);
+               printf("ipsec_register_control - proto_register_plumber(PF_INET6, %d) failed: %d\n",
+                          ipsec_family, result);
+               return result;
+       }
+
+       ipsec_lck_attr = lck_attr_alloc_init();
+       ipsec_lck_grp_attr = lck_grp_attr_alloc_init();
+       ipsec_lck_grp = lck_grp_alloc_init("ipsec", ipsec_lck_grp_attr);
+       lck_mtx_init(&ipsec_lock, ipsec_lck_grp, ipsec_lck_attr);
+       
+       return 0;
+}
+
+/* Helpers */
+int
+ipsec_interface_isvalid (ifnet_t interface)
+{
+    struct ipsec_pcb *pcb = NULL;
+    
+    if (interface == NULL)
+        return 0;
+    
+    pcb = ifnet_softc(interface);
+    
+    if (pcb == NULL)
+        return 0;
+    
+    /* When ctl disconnects, ipsec_unit is set to 0 */
+    if (pcb->ipsec_unit == 0)
+        return 0;
+    
+    return 1;
+}
+
+#if IPSEC_NEXUS
+boolean_t
+ipsec_interface_needs_netagent(ifnet_t interface)
+{
+       struct ipsec_pcb *pcb = NULL;
+
+       if (interface == NULL) {
+               return (FALSE);
+       }
+
+       pcb = ifnet_softc(interface);
+
+       if (pcb == NULL) {
+               return (FALSE);
+       }
+
+       return (pcb->ipsec_needs_netagent == true);
+}
+#endif // IPSEC_NEXUS
+
+static errno_t
+ipsec_ifnet_set_attrs(ifnet_t ifp)
+{
+       /* Set flags and additional information. */
+       ifnet_set_mtu(ifp, 1500);
+       ifnet_set_flags(ifp, IFF_UP | IFF_MULTICAST | IFF_POINTOPOINT, 0xffff);
+
+       /* The interface must generate its own IPv6 LinkLocal address,
+        * if possible following the recommendation of RFC2472 to the 64bit interface ID
+        */
+       ifnet_set_eflags(ifp, IFEF_NOAUTOIPV6LL, IFEF_NOAUTOIPV6LL);
+
+#if !IPSEC_NEXUS
+       /* Reset the stats in case as the interface may have been recycled */
+       struct ifnet_stats_param stats;
+       bzero(&stats, sizeof(struct ifnet_stats_param));
+       ifnet_set_stat(ifp, &stats);
+#endif // !IPSEC_NEXUS
+
+       return (0);
+}
+
+#if IPSEC_NEXUS
+
+static uuid_t ipsec_nx_dom_prov;
+
+static errno_t
+ipsec_nxdp_init(__unused kern_nexus_domain_provider_t domprov)
+{
+       return 0;
+}
+
+static void
+ipsec_nxdp_fini(__unused kern_nexus_domain_provider_t domprov)
+{
+       // Ignore
+}
+
+static errno_t
+ipsec_register_nexus(void)
+{
+       const struct kern_nexus_domain_provider_init dp_init = {
+               .nxdpi_version = KERN_NEXUS_DOMAIN_PROVIDER_CURRENT_VERSION,
+               .nxdpi_flags = 0,
+               .nxdpi_init = ipsec_nxdp_init,
+               .nxdpi_fini = ipsec_nxdp_fini
+       };
+       errno_t err = 0;
+
+       /* ipsec_nxdp_init() is called before this function returns */
+       err = kern_nexus_register_domain_provider(NEXUS_TYPE_NET_IF,
+                                                                                         (const uint8_t *) "com.apple.ipsec",
+                                                                                         &dp_init, sizeof(dp_init),
+                                                                                         &ipsec_nx_dom_prov);
+       if (err != 0) {
+               printf("%s: failed to register domain provider\n", __func__);
+               return (err);
+       }
+       return (0);
+}
+
+static errno_t
+ipsec_netif_prepare(kern_nexus_t nexus, ifnet_t ifp)
+{
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       pcb->ipsec_netif_nexus = nexus;
+       return (ipsec_ifnet_set_attrs(ifp));
+}
+
+static errno_t
+ipsec_nexus_pre_connect(kern_nexus_provider_t nxprov,
+                                               proc_t p, kern_nexus_t nexus,
+                                               nexus_port_t nexus_port, kern_channel_t channel, void **ch_ctx)
+{
+#pragma unused(nxprov, p)
+#pragma unused(nexus, nexus_port, channel, ch_ctx)
+       return (0);
+}
+
+static errno_t
+ipsec_nexus_connected(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                         kern_channel_t channel)
+{
+#pragma unused(nxprov, channel)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       boolean_t ok = ifnet_is_attached(pcb->ipsec_ifp, 1);
+       return (ok ? 0 : ENXIO);
+}
+
+static void
+ipsec_nexus_pre_disconnect(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                                  kern_channel_t channel)
+{
+#pragma unused(nxprov, nexus, channel)
+}
+
+static void
+ipsec_netif_pre_disconnect(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                                  kern_channel_t channel)
+{
+#pragma unused(nxprov, nexus, channel)
+}
+
+static void
+ipsec_nexus_disconnected(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                                kern_channel_t channel)
+{
+#pragma unused(nxprov, channel)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       if (pcb->ipsec_netif_nexus == nexus) {
+               pcb->ipsec_netif_nexus = NULL;
+       }
+       ifnet_decr_iorefcnt(pcb->ipsec_ifp);
+}
+
+static errno_t
+ipsec_kpipe_ring_init(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                         kern_channel_t channel, kern_channel_ring_t ring, boolean_t is_tx_ring,
+                                         void **ring_ctx)
+{
+#pragma unused(nxprov)
+#pragma unused(channel)
+#pragma unused(ring_ctx)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       if (!is_tx_ring) {
+               VERIFY(pcb->ipsec_kpipe_rxring == NULL);
+               pcb->ipsec_kpipe_rxring = ring;
+       } else {
+               VERIFY(pcb->ipsec_kpipe_txring == NULL);
+               pcb->ipsec_kpipe_txring = ring;
+       }
+       return 0;
+}
+
+static void
+ipsec_kpipe_ring_fini(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                               kern_channel_ring_t ring)
+{
+#pragma unused(nxprov)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       if (pcb->ipsec_kpipe_rxring == ring) {
+               pcb->ipsec_kpipe_rxring = NULL;
+       } else if (pcb->ipsec_kpipe_txring == ring) {
+               pcb->ipsec_kpipe_txring = NULL;
+       }
+}
+
+static errno_t
+ipsec_kpipe_sync_tx(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                         kern_channel_ring_t tx_ring, uint32_t flags)
+{
+#pragma unused(nxprov)
+#pragma unused(flags)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+
+       lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+       int channel_enabled = pcb->ipsec_kpipe_enabled;
+       if (!channel_enabled) {
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               return 0;
+       }
+
+       kern_channel_slot_t tx_slot = kern_channel_get_next_slot(tx_ring, NULL, NULL);
+       if (tx_slot == NULL) {
+               // Nothing to write, bail
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               return 0;
+       }
+
+       // Signal the netif ring to read
+       kern_channel_ring_t rx_ring = pcb->ipsec_netif_rxring;
+       lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+
+       if (rx_ring != NULL) {
+               kern_channel_notify(rx_ring, 0);
+       }
+       return 0;
+}
+
+static mbuf_t
+ipsec_encrypt_mbuf(ifnet_t interface,
+                                  mbuf_t data)
+{
+       struct ipsec_output_state ipsec_state;
+       int error = 0;
+       uint32_t af;
+
+       // Make sure this packet isn't looping through the interface
+       if (necp_get_last_interface_index_from_packet(data) == interface->if_index) {
+               error = -1;
+               goto ipsec_output_err;
+       }
+
+       // Mark the interface so NECP can evaluate tunnel policy
+       necp_mark_packet_from_interface(data, interface);
+
+       struct ip *ip = mtod(data, struct ip *);
+       u_int ip_version = ip->ip_v;
+
+       switch (ip_version) {
+               case 4: {
+                       af = AF_INET;
+
+                       memset(&ipsec_state, 0, sizeof(ipsec_state));
+                       ipsec_state.m = data;
+                       ipsec_state.dst = (struct sockaddr *)&ip->ip_dst;
+                       memset(&ipsec_state.ro, 0, sizeof(ipsec_state.ro));
+
+                       error = ipsec4_interface_output(&ipsec_state, interface);
+                       if (error == 0 && ipsec_state.tunneled == 6) {
+                               // Tunneled in IPv6 - packet is gone
+                               // TODO: Don't lose mbuf
+                               data = NULL;
+                               goto done;
+                       }
+
+                       data = ipsec_state.m;
+                       if (error || data == NULL) {
+                               if (error) {
+                                       printf("ipsec_encrypt_mbuf: ipsec4_output error %d\n", error);
+                               }
+                               goto ipsec_output_err;
+                       }
+                       goto done;
+               }
+               case 6: {
+                       af = AF_INET6;
+
+                       data = ipsec6_splithdr(data);
+                       if (data == NULL) {
+                               printf("ipsec_encrypt_mbuf: ipsec6_splithdr returned NULL\n");
+                               goto ipsec_output_err;
+                       }
+
+                       struct ip6_hdr *ip6 = mtod(data, struct ip6_hdr *);
+
+                       memset(&ipsec_state, 0, sizeof(ipsec_state));
+                       ipsec_state.m = data;
+                       ipsec_state.dst = (struct sockaddr *)&ip6->ip6_dst;
+                       memset(&ipsec_state.ro, 0, sizeof(ipsec_state.ro));
+
+                       error = ipsec6_interface_output(&ipsec_state, interface, &ip6->ip6_nxt, ipsec_state.m);
+                       if (error == 0 && ipsec_state.tunneled == 4) {
+                               // Tunneled in IPv4 - packet is gone
+                               // TODO: Don't lose mbuf
+                               data = NULL;
+                               goto done;
+                       }
+                       data = ipsec_state.m;
+                       if (error || data == NULL) {
+                               if (error) {
+                                       printf("ipsec_encrypt_mbuf: ipsec6_output error %d\n", error);
+                               }
+                               goto ipsec_output_err;
+                       }
+                       goto done;
+               }
+               default: {
+                       printf("ipsec_encrypt_mbuf: Received unknown packet version %d\n", ip_version);
+                       error = -1;
+                       goto ipsec_output_err;
+               }
+       }
+
+done:
+       return data;
+
+ipsec_output_err:
+       if (data) {
+               mbuf_freem(data);
+       }
+       return NULL;
+}
+
+static errno_t
+ipsec_kpipe_sync_rx(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                         kern_channel_ring_t rx_ring, uint32_t flags)
+{
+#pragma unused(nxprov)
+#pragma unused(flags)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       struct kern_channel_ring_stat_increment rx_ring_stats;
+
+       lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+
+       int channel_enabled = pcb->ipsec_kpipe_enabled;
+       if (!channel_enabled) {
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               return 0;
+       }
+
+       // Reclaim user-released slots
+       (void) kern_channel_reclaim(rx_ring);
+
+       uint32_t avail = kern_channel_available_slot_count(rx_ring);
+       if (avail == 0) {
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               return 0;
+       }
+
+       kern_channel_ring_t tx_ring = pcb->ipsec_netif_txring;
+       if (tx_ring == NULL) {
+               // Net-If TX ring not set up yet, nothing to read
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               return 0;
+       }
+
+       struct netif_stats *nifs = &NX_NETIF_PRIVATE(pcb->ipsec_netif_nexus)->nif_stats;
+
+       // Unlock ipsec before entering ring
+       lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+
+       (void)kr_enter(tx_ring, TRUE);
+
+       // Lock again after entering and validate
+       lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+       if (tx_ring != pcb->ipsec_netif_txring) {
+               // Ring no longer valid
+               // Unlock first, then exit ring
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               kr_exit(tx_ring);
+               return 0;
+       }
+
+
+       struct kern_channel_ring_stat_increment tx_ring_stats;
+       bzero(&tx_ring_stats, sizeof(tx_ring_stats));
+       kern_channel_slot_t tx_pslot = NULL;
+       kern_channel_slot_t tx_slot = kern_channel_get_next_slot(tx_ring, NULL, NULL);
+       if (tx_slot == NULL) {
+               // Nothing to read, don't bother signalling
+               // Unlock first, then exit ring
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               kr_exit(tx_ring);
+               return 0;
+       }
+
+       struct kern_pbufpool *rx_pp = rx_ring->ckr_pp;
+       VERIFY(rx_pp != NULL);
+       bzero(&rx_ring_stats, sizeof(rx_ring_stats));
+       kern_channel_slot_t rx_pslot = NULL;
+       kern_channel_slot_t rx_slot = kern_channel_get_next_slot(rx_ring, NULL, NULL);
+
+       while (rx_slot != NULL && tx_slot != NULL) {
+               size_t length = 0;
+               mbuf_t data = NULL;
+               errno_t error = 0;
+
+               // Allocate rx packet
+               kern_packet_t rx_ph = 0;
+               error = kern_pbufpool_alloc_nosleep(rx_pp, 1, &rx_ph);
+               if (__improbable(error != 0)) {
+                       printf("ipsec_kpipe_sync_rx %s: failed to allocate packet\n",
+                                  pcb->ipsec_ifp->if_xname);
+                       break;
+               }
+
+               kern_packet_t tx_ph = kern_channel_slot_get_packet(tx_ring, tx_slot);
+
+               // Advance TX ring
+               tx_pslot = tx_slot;
+               tx_slot = kern_channel_get_next_slot(tx_ring, tx_slot, NULL);
+
+               if (tx_ph == 0) {
+                       kern_pbufpool_free(rx_pp, rx_ph);
+                       continue;
+               }
+               
+               kern_buflet_t tx_buf = kern_packet_get_next_buflet(tx_ph, NULL);
+               VERIFY(tx_buf != NULL);
+               uint8_t *tx_baddr = kern_buflet_get_object_address(tx_buf);
+               VERIFY(tx_baddr != NULL);
+               tx_baddr += kern_buflet_get_data_offset(tx_buf);
+
+               bpf_tap_packet_out(pcb->ipsec_ifp, DLT_RAW, tx_ph, NULL, 0);
+
+               length = MIN(kern_packet_get_data_length(tx_ph),
+                                        pcb->ipsec_slot_size);
+
+               // Increment TX stats
+               tx_ring_stats.kcrsi_slots_transferred++;
+               tx_ring_stats.kcrsi_bytes_transferred += length;
+
+               if (length > 0) {
+                       error = mbuf_gethdr(MBUF_DONTWAIT, MBUF_TYPE_HEADER, &data);
+                       if (error == 0) {
+                               error = mbuf_copyback(data, 0, length, tx_baddr, MBUF_DONTWAIT);
+                               if (error == 0) {
+                                       // Encrypt and send packet
+                                       data = ipsec_encrypt_mbuf(pcb->ipsec_ifp, data);
+                               } else {
+                                       printf("ipsec_kpipe_sync_rx %s - mbuf_copyback(%zu) error %d\n", pcb->ipsec_ifp->if_xname, length, error);
+                                       STATS_INC(nifs, NETIF_STATS_NOMEM_MBUF);
+                                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                       mbuf_freem(data);
+                                       data = NULL;
+                               }
+                       } else {
+                               printf("ipsec_kpipe_sync_rx %s - mbuf_gethdr error %d\n", pcb->ipsec_ifp->if_xname, error);
+                               STATS_INC(nifs, NETIF_STATS_NOMEM_MBUF);
+                               STATS_INC(nifs, NETIF_STATS_DROPPED);
+                       }
+               } else {
+                       printf("ipsec_kpipe_sync_rx %s - 0 length packet\n", pcb->ipsec_ifp->if_xname);
+                       STATS_INC(nifs, NETIF_STATS_BADLEN);
+                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+               }
+
+               if (data == NULL) {
+                       printf("ipsec_kpipe_sync_rx %s: no encrypted packet to send\n", pcb->ipsec_ifp->if_xname);
+                       kern_pbufpool_free(rx_pp, rx_ph);
+                       break;
+               }
+
+               length = mbuf_pkthdr_len(data);
+               if (length > rx_pp->pp_buflet_size) {
+                       // Flush data
+                       mbuf_freem(data);
+                       kern_pbufpool_free(rx_pp, rx_ph);
+                       printf("ipsec_kpipe_sync_rx %s: encrypted packet length %zu > %u\n",
+                                  pcb->ipsec_ifp->if_xname, length, rx_pp->pp_buflet_size);
+                       continue;
+               }
+
+               // Fillout rx packet
+               kern_buflet_t rx_buf = kern_packet_get_next_buflet(rx_ph, NULL);
+               VERIFY(rx_buf != NULL);
+               void *rx_baddr = kern_buflet_get_object_address(rx_buf);
+               VERIFY(rx_baddr != NULL);
+
+               // Copy-in data from mbuf to buflet
+               mbuf_copydata(data, 0, length, (void *)rx_baddr);
+               kern_packet_clear_flow_uuid(rx_ph);     // Zero flow id
+
+               // Finalize and attach the packet
+               error = kern_buflet_set_data_offset(rx_buf, 0);
+               VERIFY(error == 0);
+               error = kern_buflet_set_data_length(rx_buf, length);
+               VERIFY(error == 0);
+               error = kern_packet_finalize(rx_ph);
+               VERIFY(error == 0);
+               error = kern_channel_slot_attach_packet(rx_ring, rx_slot, rx_ph);
+               VERIFY(error == 0);
+
+               STATS_INC(nifs, NETIF_STATS_TXPKTS);
+               STATS_INC(nifs, NETIF_STATS_TXCOPY_DIRECT);
+
+               rx_ring_stats.kcrsi_slots_transferred++;
+               rx_ring_stats.kcrsi_bytes_transferred += length;
+
+               if (!pcb->ipsec_ext_ifdata_stats) {
+                       ifnet_stat_increment_out(pcb->ipsec_ifp, 1, length, 0);
+               }
+
+               mbuf_freem(data);
+
+               rx_pslot = rx_slot;
+               rx_slot = kern_channel_get_next_slot(rx_ring, rx_slot, NULL);
+       }
+
+       if (rx_pslot) {
+               kern_channel_advance_slot(rx_ring, rx_pslot);
+               kern_channel_increment_ring_net_stats(rx_ring, pcb->ipsec_ifp, &rx_ring_stats);
+       }
+
+       if (tx_pslot) {
+               kern_channel_advance_slot(tx_ring, tx_pslot);
+               kern_channel_increment_ring_net_stats(tx_ring, pcb->ipsec_ifp, &tx_ring_stats);
+               (void)kern_channel_reclaim(tx_ring);
+       }
+
+       /* always reenable output */
+       errno_t error = ifnet_enable_output(pcb->ipsec_ifp);
+       if (error != 0) {
+               printf("ipsec_kpipe_sync_rx: ifnet_enable_output returned error %d\n", error);
+       }
+
+       // Unlock first, then exit ring
+       lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+
+       if (tx_pslot != NULL) {
+               kern_channel_notify(tx_ring, 0);
+       }
+       kr_exit(tx_ring);
+
+       return 0;
+}
+
+static errno_t
+ipsec_netif_ring_init(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                         kern_channel_t channel, kern_channel_ring_t ring, boolean_t is_tx_ring,
+                                         void **ring_ctx)
+{
+#pragma unused(nxprov)
+#pragma unused(channel)
+#pragma unused(ring_ctx)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       if (!is_tx_ring) {
+               VERIFY(pcb->ipsec_netif_rxring == NULL);
+               pcb->ipsec_netif_rxring = ring;
+       } else {
+               VERIFY(pcb->ipsec_netif_txring == NULL);
+               pcb->ipsec_netif_txring = ring;
+       }
+       return 0;
+}
+
+static void
+ipsec_netif_ring_fini(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                         kern_channel_ring_t ring)
+{
+#pragma unused(nxprov)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       if (pcb->ipsec_netif_rxring == ring) {
+               pcb->ipsec_netif_rxring = NULL;
+       } else if (pcb->ipsec_netif_txring == ring) {
+               pcb->ipsec_netif_txring = NULL;
+       }
+}
+
+static bool
+ipsec_netif_check_policy(mbuf_t data)
+{
+       necp_kernel_policy_result necp_result = 0;
+       necp_kernel_policy_result_parameter necp_result_parameter = {};
+       uint32_t necp_matched_policy_id = 0;
+
+       // This packet has been marked with IP level policy, do not mark again.
+       if (data && data->m_pkthdr.necp_mtag.necp_policy_id >= NECP_KERNEL_POLICY_ID_FIRST_VALID_IP) {
+               return (true);
+       }
+
+       size_t length = mbuf_pkthdr_len(data);
+       if (length < sizeof(struct ip)) {
+               return (false);
+       }
+
+       struct ip *ip = mtod(data, struct ip *);
+       u_int ip_version = ip->ip_v;
+       switch (ip_version) {
+               case 4: {
+                       necp_matched_policy_id = necp_ip_output_find_policy_match(data, 0, NULL,
+                                                                                                                                         &necp_result, &necp_result_parameter);
+                       break;
+               }
+               case 6: {
+                       necp_matched_policy_id = necp_ip6_output_find_policy_match(data, 0, NULL,
+                                                                                                                                          &necp_result, &necp_result_parameter);
+                       break;
+               }
+               default: {
+                       return (false);
+               }
+       }
+
+       if (necp_result == NECP_KERNEL_POLICY_RESULT_DROP ||
+               necp_result == NECP_KERNEL_POLICY_RESULT_SOCKET_DIVERT) {
+               /* Drop and flow divert packets should be blocked at the IP layer */
+               return (false);
+       }
+
+       necp_mark_packet_from_ip(data, necp_matched_policy_id);
+       return (true);
+}
+
+static errno_t
+ipsec_netif_sync_tx(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                       kern_channel_ring_t tx_ring, uint32_t flags)
+{
+#pragma unused(nxprov)
+#pragma unused(flags)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+
+       struct netif_stats *nifs = &NX_NETIF_PRIVATE(nexus)->nif_stats;
+
+       lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+
+       struct kern_channel_ring_stat_increment tx_ring_stats;
+       bzero(&tx_ring_stats, sizeof(tx_ring_stats));
+       kern_channel_slot_t tx_pslot = NULL;
+       kern_channel_slot_t tx_slot = kern_channel_get_next_slot(tx_ring, NULL, NULL);
+
+       STATS_INC(nifs, NETIF_STATS_TXSYNC);
+
+       if (tx_slot == NULL) {
+               // Nothing to write, don't bother signalling
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               return 0;
+       }
+
+       if (pcb->ipsec_kpipe_enabled) {
+               kern_channel_ring_t rx_ring = pcb->ipsec_kpipe_rxring;
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+
+               // Signal the kernel pipe ring to read
+               if (rx_ring != NULL) {
+                       kern_channel_notify(rx_ring, 0);
+               }
+               return 0;
+       }
+
+       // If we're here, we're injecting into the BSD stack
+       while (tx_slot != NULL) {
+               size_t length = 0;
+               mbuf_t data = NULL;
+
+               kern_packet_t tx_ph = kern_channel_slot_get_packet(tx_ring, tx_slot);
+
+               // Advance TX ring
+               tx_pslot = tx_slot;
+               tx_slot = kern_channel_get_next_slot(tx_ring, tx_slot, NULL);
+
+               if (tx_ph == 0) {
+                       continue;
+               }
+
+               kern_buflet_t tx_buf = kern_packet_get_next_buflet(tx_ph, NULL);
+               VERIFY(tx_buf != NULL);
+               uint8_t *tx_baddr = kern_buflet_get_object_address(tx_buf);
+               VERIFY(tx_baddr != 0);
+               tx_baddr += kern_buflet_get_data_offset(tx_buf);
+
+               bpf_tap_packet_out(pcb->ipsec_ifp, DLT_RAW, tx_ph, NULL, 0);
+
+               length = MIN(kern_packet_get_data_length(tx_ph),
+                                        pcb->ipsec_slot_size);
+
+               if (length > 0) {
+                       errno_t error = mbuf_gethdr(MBUF_DONTWAIT, MBUF_TYPE_HEADER, &data);
+                       if (error == 0) {
+                               error = mbuf_copyback(data, 0, length, tx_baddr, MBUF_DONTWAIT);
+                               if (error == 0) {
+                                       // Mark packet from policy
+                                       uint32_t policy_id = kern_packet_get_policy_id(tx_ph);
+                                       necp_mark_packet_from_ip(data, policy_id);
+
+                                       // Check policy with NECP
+                                       if (!ipsec_netif_check_policy(data)) {
+                                               printf("ipsec_netif_sync_tx %s - failed policy check\n", pcb->ipsec_ifp->if_xname);
+                                               STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                               mbuf_freem(data);
+                                               data = NULL;
+                                       } else {
+                                               // Send through encryption
+                                               error = ipsec_output(pcb->ipsec_ifp, data);
+                                               if (error != 0) {
+                                                       printf("ipsec_netif_sync_tx %s - ipsec_output error %d\n", pcb->ipsec_ifp->if_xname, error);
+                                               }
+                                       }
+                               } else {
+                                       printf("ipsec_netif_sync_tx %s - mbuf_copyback(%zu) error %d\n", pcb->ipsec_ifp->if_xname, length, error);
+                                       STATS_INC(nifs, NETIF_STATS_NOMEM_MBUF);
+                                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                       mbuf_freem(data);
+                                       data = NULL;
+                               }
+                       } else {
+                               printf("ipsec_netif_sync_tx %s - mbuf_gethdr error %d\n", pcb->ipsec_ifp->if_xname, error);
+                               STATS_INC(nifs, NETIF_STATS_NOMEM_MBUF);
+                               STATS_INC(nifs, NETIF_STATS_DROPPED);
+                       }
+               } else {
+                       printf("ipsec_netif_sync_tx %s - 0 length packet\n", pcb->ipsec_ifp->if_xname);
+                       STATS_INC(nifs, NETIF_STATS_BADLEN);
+                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+               }
+
+               if (data == NULL) {
+                       printf("ipsec_netif_sync_tx %s: no encrypted packet to send\n", pcb->ipsec_ifp->if_xname);
+                       break;
+               }
+
+               STATS_INC(nifs, NETIF_STATS_TXPKTS);
+               STATS_INC(nifs, NETIF_STATS_TXCOPY_MBUF);
+
+               tx_ring_stats.kcrsi_slots_transferred++;
+               tx_ring_stats.kcrsi_bytes_transferred += length;
+       }
+
+       if (tx_pslot) {
+               kern_channel_advance_slot(tx_ring, tx_pslot);
+               kern_channel_increment_ring_net_stats(tx_ring, pcb->ipsec_ifp, &tx_ring_stats);
+               (void)kern_channel_reclaim(tx_ring);
+       }
+
+       lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+
+       return 0;
+}
+
+static errno_t
+ipsec_netif_tx_doorbell(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                               kern_channel_ring_t ring, __unused uint32_t flags)
+{
+#pragma unused(nxprov)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       boolean_t more = false;
+       errno_t rc = 0;
+
+       /*
+        * Refill and sync the ring; we may be racing against another thread doing
+        * an RX sync that also wants to do kr_enter(), and so use the blocking
+        * variant here.
+        */
+       rc = kern_channel_tx_refill_canblock(ring, UINT32_MAX, UINT32_MAX, true, &more);
+       if (rc != 0 && rc != EAGAIN && rc != EBUSY) {
+               printf("%s, tx refill failed %d\n", __func__, rc);
+       }
+
+       (void) kr_enter(ring, TRUE);
+       lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+
+       if (pcb->ipsec_kpipe_enabled) {
+               uint32_t tx_available = kern_channel_available_slot_count(ring);
+               if (pcb->ipsec_netif_txring_size > 0 &&
+                       tx_available >= pcb->ipsec_netif_txring_size - 1) {
+                       // No room left in tx ring, disable output for now
+                       errno_t error = ifnet_disable_output(pcb->ipsec_ifp);
+                       if (error != 0) {
+                               printf("ipsec_netif_tx_doorbell: ifnet_disable_output returned error %d\n", error);
+                       }
+               }
+       }
+
+       if (pcb->ipsec_kpipe_enabled) {
+               kern_channel_ring_t rx_ring = pcb->ipsec_kpipe_rxring;
+
+               // Unlock while calling notify
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               // Signal the kernel pipe ring to read
+               if (rx_ring != NULL) {
+                       kern_channel_notify(rx_ring, 0);
+               }
+       } else {
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+       }
+
+       kr_exit(ring);
+
+       return (0);
+}
+
+static errno_t
+ipsec_netif_sync_rx(kern_nexus_provider_t nxprov, kern_nexus_t nexus,
+                                       kern_channel_ring_t rx_ring, uint32_t flags)
+{
+#pragma unused(nxprov)
+#pragma unused(flags)
+       struct ipsec_pcb *pcb = kern_nexus_get_context(nexus);
+       struct kern_channel_ring_stat_increment rx_ring_stats;
+
+       struct netif_stats *nifs = &NX_NETIF_PRIVATE(nexus)->nif_stats;
+
+       lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+
+       // Reclaim user-released slots
+       (void) kern_channel_reclaim(rx_ring);
+
+       STATS_INC(nifs, NETIF_STATS_RXSYNC);
+
+       uint32_t avail = kern_channel_available_slot_count(rx_ring);
+       if (avail == 0) {
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+               return 0;
+       }
+
+       struct kern_pbufpool *rx_pp = rx_ring->ckr_pp;
+       VERIFY(rx_pp != NULL);
+       bzero(&rx_ring_stats, sizeof(rx_ring_stats));
+       kern_channel_slot_t rx_pslot = NULL;
+       kern_channel_slot_t rx_slot = kern_channel_get_next_slot(rx_ring, NULL, NULL);
+
+       while (rx_slot != NULL) {
+               // Check for a waiting packet
+               lck_mtx_lock(&pcb->ipsec_input_chain_lock);
+               mbuf_t data = pcb->ipsec_input_chain;
+               if (data == NULL) {
+                       lck_mtx_unlock(&pcb->ipsec_input_chain_lock);
+                       break;
+               }
+
+               // Allocate rx packet
+               kern_packet_t rx_ph = 0;
+               errno_t error = kern_pbufpool_alloc_nosleep(rx_pp, 1, &rx_ph);
+               if (__improbable(error != 0)) {
+                       STATS_INC(nifs, NETIF_STATS_NOMEM_PKT);
+                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                       lck_mtx_unlock(&pcb->ipsec_input_chain_lock);
+                       break;
+               }
+
+               // Advance waiting packets
+               pcb->ipsec_input_chain = data->m_nextpkt;
+               data->m_nextpkt = NULL;
+               if (pcb->ipsec_input_chain == NULL) {
+                       pcb->ipsec_input_chain_last = NULL;
+               }
+               lck_mtx_unlock(&pcb->ipsec_input_chain_lock);
+
+               size_t length = mbuf_pkthdr_len(data);
+
+               if (length < sizeof(struct ip)) {
+                       // Flush data
+                       mbuf_freem(data);
+                       kern_pbufpool_free(rx_pp, rx_ph);
+                       STATS_INC(nifs, NETIF_STATS_BADLEN);
+                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                       printf("ipsec_netif_sync_rx %s: legacy decrypted packet length cannot hold IP %zu < %zu\n",
+                                  pcb->ipsec_ifp->if_xname, length, sizeof(struct ip));
+                       continue;
+               }
+
+               uint32_t af = 0;
+               struct ip *ip = mtod(data, struct ip *);
+               u_int ip_version = ip->ip_v;
+               switch (ip_version) {
+                       case 4: {
+                               af = AF_INET;
+                               break;
+                       }
+                       case 6: {
+                               af = AF_INET6;
+                               break;
+                       }
+                       default: {
+                               printf("ipsec_netif_sync_rx %s: legacy unknown ip version %u\n",
+                                          pcb->ipsec_ifp->if_xname, ip_version);
+                               break;
+                       }
+               }
+
+               if (length > rx_pp->pp_buflet_size ||
+                       (pcb->ipsec_frag_size_set && length > pcb->ipsec_input_frag_size)) {
+
+                       // We need to fragment to send up into the netif
+
+                       u_int32_t fragment_mtu = rx_pp->pp_buflet_size;
+                       if (pcb->ipsec_frag_size_set &&
+                               pcb->ipsec_input_frag_size < rx_pp->pp_buflet_size) {
+                               fragment_mtu = pcb->ipsec_input_frag_size;
+                       }
+
+                       mbuf_t fragment_chain = NULL;
+                       switch (af) {
+                               case AF_INET: {
+                                       // ip_fragment expects the length in host order
+                                       ip->ip_len = ntohs(ip->ip_len);
+
+                                       // ip_fragment will modify the original data, don't free
+                                       int fragment_error = ip_fragment(data, pcb->ipsec_ifp, fragment_mtu, TRUE);
+                                       if (fragment_error == 0 && data != NULL) {
+                                               fragment_chain = data;
+                                       } else {
+                                               STATS_INC(nifs, NETIF_STATS_BADLEN);
+                                               STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                               printf("ipsec_netif_sync_rx %s: failed to fragment IPv4 packet of length %zu (%d)\n",
+                                                          pcb->ipsec_ifp->if_xname, length, fragment_error);
+                                       }
+                                       break;
+                               }
+                               case AF_INET6: {
+                                       if (length < sizeof(struct ip6_hdr)) {
+                                               mbuf_freem(data);
+                                               STATS_INC(nifs, NETIF_STATS_BADLEN);
+                                               STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                               printf("ipsec_netif_sync_rx %s: failed to fragment IPv6 packet of length %zu < %zu\n",
+                                                          pcb->ipsec_ifp->if_xname, length, sizeof(struct ip6_hdr));
+                                       } else {
+
+                                               // ip6_do_fragmentation will free the original data on success only
+                                               struct ip6_hdr *ip6 = mtod(data, struct ip6_hdr *);
+                                               struct ip6_exthdrs exthdrs;
+                                               memset(&exthdrs, 0, sizeof(exthdrs));
+
+                                               int fragment_error = ip6_do_fragmentation(&data, 0, pcb->ipsec_ifp, sizeof(struct ip6_hdr),
+                                                                                                                                 ip6, &exthdrs, fragment_mtu, ip6->ip6_nxt);
+                                               if (fragment_error == 0 && data != NULL) {
+                                                       fragment_chain = data;
+                                               } else {
+                                                       mbuf_freem(data);
+                                                       STATS_INC(nifs, NETIF_STATS_BADLEN);
+                                                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                                       printf("ipsec_netif_sync_rx %s: failed to fragment IPv6 packet of length %zu (%d)\n",
+                                                                  pcb->ipsec_ifp->if_xname, length, fragment_error);
+                                               }
+                                       }
+                                       break;
+                               }
+                               default: {
+                                       // Cannot fragment unknown families
+                                       mbuf_freem(data);
+                                       STATS_INC(nifs, NETIF_STATS_BADLEN);
+                                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                       printf("ipsec_netif_sync_rx %s: uknown legacy decrypted packet length %zu > %u\n",
+                                                  pcb->ipsec_ifp->if_xname, length, rx_pp->pp_buflet_size);
+                                       break;
+                               }
+                       }
+
+                       if (fragment_chain != NULL) {
+                               // Add fragments to chain before continuing
+                               lck_mtx_lock(&pcb->ipsec_input_chain_lock);
+                               if (pcb->ipsec_input_chain != NULL) {
+                                       pcb->ipsec_input_chain_last->m_nextpkt = fragment_chain;
+                               } else {
+                                       pcb->ipsec_input_chain = fragment_chain;
+                               }
+                               while (fragment_chain->m_nextpkt) {
+                                       VERIFY(fragment_chain != fragment_chain->m_nextpkt);
+                                       fragment_chain = fragment_chain->m_nextpkt;
+                               }
+                               pcb->ipsec_input_chain_last = fragment_chain;
+                               lck_mtx_unlock(&pcb->ipsec_input_chain_lock);
+                       }
+
+                       // Make sure to free unused rx packet
+                       kern_pbufpool_free(rx_pp, rx_ph);
+
+                       continue;
+               }
+
+               mbuf_pkthdr_setrcvif(data, pcb->ipsec_ifp);
+
+               // Fillout rx packet
+               kern_buflet_t rx_buf = kern_packet_get_next_buflet(rx_ph, NULL);
+               VERIFY(rx_buf != NULL);
+               void *rx_baddr = kern_buflet_get_object_address(rx_buf);
+               VERIFY(rx_baddr != NULL);
+
+               // Copy-in data from mbuf to buflet
+               mbuf_copydata(data, 0, length, (void *)rx_baddr);
+               kern_packet_clear_flow_uuid(rx_ph);     // Zero flow id
+
+               // Finalize and attach the packet
+               error = kern_buflet_set_data_offset(rx_buf, 0);
+               VERIFY(error == 0);
+               error = kern_buflet_set_data_length(rx_buf, length);
+               VERIFY(error == 0);
+               error = kern_packet_set_link_header_offset(rx_ph, 0);
+               VERIFY(error == 0);
+               error = kern_packet_set_network_header_offset(rx_ph, 0);
+               VERIFY(error == 0);
+               error = kern_packet_finalize(rx_ph);
+               VERIFY(error == 0);
+               error = kern_channel_slot_attach_packet(rx_ring, rx_slot, rx_ph);
+               VERIFY(error == 0);
+
+               STATS_INC(nifs, NETIF_STATS_RXPKTS);
+               STATS_INC(nifs, NETIF_STATS_RXCOPY_MBUF);
+               bpf_tap_packet_in(pcb->ipsec_ifp, DLT_RAW, rx_ph, NULL, 0);
+
+               rx_ring_stats.kcrsi_slots_transferred++;
+               rx_ring_stats.kcrsi_bytes_transferred += length;
+
+               if (!pcb->ipsec_ext_ifdata_stats) {
+                       ifnet_stat_increment_in(pcb->ipsec_ifp, 1, length, 0);
+               }
+
+               mbuf_freem(data);
+
+               // Advance ring
+               rx_pslot = rx_slot;
+               rx_slot = kern_channel_get_next_slot(rx_ring, rx_slot, NULL);
+       }
+
+       struct kern_channel_ring_stat_increment tx_ring_stats;
+       bzero(&tx_ring_stats, sizeof(tx_ring_stats));
+       kern_channel_ring_t tx_ring = pcb->ipsec_kpipe_txring;
+       kern_channel_slot_t tx_pslot = NULL;
+       kern_channel_slot_t tx_slot = NULL;
+       if (tx_ring == NULL) {
+               // Net-If TX ring not set up yet, nothing to read
+               goto done;
+       }
+
+
+       // Unlock ipsec before entering ring
+       lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+
+       (void)kr_enter(tx_ring, TRUE);
+
+       // Lock again after entering and validate
+       lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+
+       if (tx_ring != pcb->ipsec_kpipe_txring) {
+               goto done;
+       }
+
+       tx_slot = kern_channel_get_next_slot(tx_ring, NULL, NULL);
+       if (tx_slot == NULL) {
+               // Nothing to read, don't bother signalling
+               goto done;
+       }
+
+       while (rx_slot != NULL && tx_slot != NULL) {
+               size_t length = 0;
+               mbuf_t data = NULL;
+               errno_t error = 0;
+               uint32_t af;
+
+               // Allocate rx packet
+               kern_packet_t rx_ph = 0;
+               error = kern_pbufpool_alloc_nosleep(rx_pp, 1, &rx_ph);
+               if (__improbable(error != 0)) {
+                       STATS_INC(nifs, NETIF_STATS_NOMEM_PKT);
+                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                       break;
+               }
+
+               kern_packet_t tx_ph = kern_channel_slot_get_packet(tx_ring, tx_slot);
+
+               // Advance TX ring
+               tx_pslot = tx_slot;
+               tx_slot = kern_channel_get_next_slot(tx_ring, tx_slot, NULL);
+
+               if (tx_ph == 0) {
+                       kern_pbufpool_free(rx_pp, rx_ph);
+                       continue;
+               }
+
+               kern_buflet_t tx_buf = kern_packet_get_next_buflet(tx_ph, NULL);
+               VERIFY(tx_buf != NULL);
+               uint8_t *tx_baddr = kern_buflet_get_object_address(tx_buf);
+               VERIFY(tx_baddr != 0);
+               tx_baddr += kern_buflet_get_data_offset(tx_buf);
+
+               length = MIN(kern_packet_get_data_length(tx_ph),
+                                        pcb->ipsec_slot_size);
+
+               // Increment TX stats
+               tx_ring_stats.kcrsi_slots_transferred++;
+               tx_ring_stats.kcrsi_bytes_transferred += length;
+
+               if (length >= sizeof(struct ip)) {
+                       error = mbuf_gethdr(MBUF_DONTWAIT, MBUF_TYPE_HEADER, &data);
+                       if (error == 0) {
+                               error = mbuf_copyback(data, 0, length, tx_baddr, MBUF_DONTWAIT);
+                               if (error == 0) {
+                                       struct ip *ip = mtod(data, struct ip *);
+                                       u_int ip_version = ip->ip_v;
+                                       switch (ip_version) {
+                                               case 4: {
+                                                       af = AF_INET;
+                                                       ip->ip_len = ntohs(ip->ip_len) - sizeof(struct ip);
+                                                       ip->ip_off = ntohs(ip->ip_off);
+
+                                                       if (length < ip->ip_len) {
+                                                               printf("ipsec_netif_sync_rx %s: IPv4 packet length too short (%zu < %u)\n",
+                                                                          pcb->ipsec_ifp->if_xname, length, ip->ip_len);
+                                                               STATS_INC(nifs, NETIF_STATS_BADLEN);
+                                                               STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                                               mbuf_freem(data);
+                                                               data = NULL;
+                                                       } else {
+                                                               data = esp4_input_extended(data, sizeof(struct ip), pcb->ipsec_ifp);
+                                                       }
+                                                       break;
+                                               }
+                                               case 6: {
+                                                       if (length < sizeof(struct ip6_hdr)) {
+                                                               printf("ipsec_netif_sync_rx %s: IPv6 packet length too short for header %zu\n",
+                                                                          pcb->ipsec_ifp->if_xname, length);
+                                                               STATS_INC(nifs, NETIF_STATS_BADLEN);
+                                                               STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                                               mbuf_freem(data);
+                                                               data = NULL;
+                                                       } else {
+                                                               af = AF_INET6;
+                                                               struct ip6_hdr *ip6 = mtod(data, struct ip6_hdr *);
+                                                               const size_t ip6_len = sizeof(*ip6) + ntohs(ip6->ip6_plen);
+                                                               if (length < ip6_len) {
+                                                                       printf("ipsec_netif_sync_rx %s: IPv6 packet length too short (%zu < %zu)\n",
+                                                                                  pcb->ipsec_ifp->if_xname, length, ip6_len);
+                                                                       STATS_INC(nifs, NETIF_STATS_BADLEN);
+                                                                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                                                       mbuf_freem(data);
+                                                                       data = NULL;
+                                                               } else {
+                                                                       int offset = sizeof(struct ip6_hdr);
+                                                                       esp6_input_extended(&data, &offset, ip6->ip6_nxt, pcb->ipsec_ifp);
+                                                               }
+                                                       }
+                                                       break;
+                                               }
+                                               default: {
+                                                       printf("ipsec_netif_sync_rx %s: unknown ip version %u\n",
+                                                                  pcb->ipsec_ifp->if_xname, ip_version);
+                                                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                                       mbuf_freem(data);
+                                                       data = NULL;
+                                                       break;
+                                               }
+                                       }
+                               } else {
+                                       printf("ipsec_netif_sync_rx %s - mbuf_copyback(%zu) error %d\n", pcb->ipsec_ifp->if_xname, length, error);
+                                       STATS_INC(nifs, NETIF_STATS_NOMEM_MBUF);
+                                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                                       mbuf_freem(data);
+                                       data = NULL;
+                               }
+                       } else {
+                               printf("ipsec_netif_sync_rx %s - mbuf_gethdr error %d\n", pcb->ipsec_ifp->if_xname, error);
+                               STATS_INC(nifs, NETIF_STATS_NOMEM_MBUF);
+                               STATS_INC(nifs, NETIF_STATS_DROPPED);
+                       }
+               } else {
+                       printf("ipsec_netif_sync_rx %s - bad packet length %zu\n", pcb->ipsec_ifp->if_xname, length);
+                       STATS_INC(nifs, NETIF_STATS_BADLEN);
+                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+               }
+
+               if (data == NULL) {
+                       // Failed to get decrypted data data
+                       kern_pbufpool_free(rx_pp, rx_ph);
+                       continue;
+               }
+
+               length = mbuf_pkthdr_len(data);
+               if (length > rx_pp->pp_buflet_size) {
+                       // Flush data
+                       mbuf_freem(data);
+                       kern_pbufpool_free(rx_pp, rx_ph);
+                       STATS_INC(nifs, NETIF_STATS_BADLEN);
+                       STATS_INC(nifs, NETIF_STATS_DROPPED);
+                       printf("ipsec_netif_sync_rx %s: decrypted packet length %zu > %u\n",
+                                  pcb->ipsec_ifp->if_xname, length, rx_pp->pp_buflet_size);
+                       continue;
+               }
+
+               mbuf_pkthdr_setrcvif(data, pcb->ipsec_ifp);
+
+               // Fillout rx packet
+               kern_buflet_t rx_buf = kern_packet_get_next_buflet(rx_ph, NULL);
+               VERIFY(rx_buf != NULL);
+               void *rx_baddr = kern_buflet_get_object_address(rx_buf);
+               VERIFY(rx_baddr != NULL);
+
+               // Copy-in data from mbuf to buflet
+               mbuf_copydata(data, 0, length, (void *)rx_baddr);
+               kern_packet_clear_flow_uuid(rx_ph);     // Zero flow id
+
+               // Finalize and attach the packet
+               error = kern_buflet_set_data_offset(rx_buf, 0);
+               VERIFY(error == 0);
+               error = kern_buflet_set_data_length(rx_buf, length);
+               VERIFY(error == 0);
+               error = kern_packet_set_link_header_offset(rx_ph, 0);
+               VERIFY(error == 0);
+               error = kern_packet_set_network_header_offset(rx_ph, 0);
+               VERIFY(error == 0);
+               error = kern_packet_finalize(rx_ph);
+               VERIFY(error == 0);
+               error = kern_channel_slot_attach_packet(rx_ring, rx_slot, rx_ph);
+               VERIFY(error == 0);
+
+               STATS_INC(nifs, NETIF_STATS_RXPKTS);
+               STATS_INC(nifs, NETIF_STATS_RXCOPY_DIRECT);
+               bpf_tap_packet_in(pcb->ipsec_ifp, DLT_RAW, rx_ph, NULL, 0);
+
+               rx_ring_stats.kcrsi_slots_transferred++;
+               rx_ring_stats.kcrsi_bytes_transferred += length;
+
+               if (!pcb->ipsec_ext_ifdata_stats) {
+                       ifnet_stat_increment_in(pcb->ipsec_ifp, 1, length, 0);
+               }
+
+               mbuf_freem(data);
+
+               rx_pslot = rx_slot;
+               rx_slot = kern_channel_get_next_slot(rx_ring, rx_slot, NULL);
+       }
+
+done:
+       if (rx_pslot) {
+               kern_channel_advance_slot(rx_ring, rx_pslot);
+               kern_channel_increment_ring_net_stats(rx_ring, pcb->ipsec_ifp, &rx_ring_stats);
+       }
+
+       if (tx_pslot) {
+               kern_channel_advance_slot(tx_ring, tx_pslot);
+               kern_channel_increment_ring_net_stats(tx_ring, pcb->ipsec_ifp, &tx_ring_stats);
+               (void)kern_channel_reclaim(tx_ring);
+       }
+
+       // Unlock first, then exit ring
+       lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+       if (tx_ring != NULL) {
+               if (tx_pslot != NULL) {
+                       kern_channel_notify(tx_ring, 0);
+               }
+               kr_exit(tx_ring);
+       }
+
+       return 0;
+}
+
+static errno_t
+ipsec_nexus_ifattach(struct ipsec_pcb *pcb,
+                                        struct ifnet_init_eparams *init_params,
+                                        struct ifnet **ifp)
+{
+       errno_t err;
+       nexus_controller_t controller = kern_nexus_shared_controller();
+       struct kern_nexus_net_init net_init;
+       struct kern_pbufpool_init pp_init;
+
+       nexus_name_t provider_name;
+       snprintf((char *)provider_name, sizeof(provider_name),
+                        "com.apple.netif.%s", pcb->ipsec_if_xname);
+
+       struct kern_nexus_provider_init prov_init = {
+               .nxpi_version = KERN_NEXUS_DOMAIN_PROVIDER_CURRENT_VERSION,
+               .nxpi_flags = NXPIF_VIRTUAL_DEVICE,
+               .nxpi_pre_connect = ipsec_nexus_pre_connect,
+               .nxpi_connected = ipsec_nexus_connected,
+               .nxpi_pre_disconnect = ipsec_netif_pre_disconnect,
+               .nxpi_disconnected = ipsec_nexus_disconnected,
+               .nxpi_ring_init = ipsec_netif_ring_init,
+               .nxpi_ring_fini = ipsec_netif_ring_fini,
+               .nxpi_slot_init = NULL,
+               .nxpi_slot_fini = NULL,
+               .nxpi_sync_tx = ipsec_netif_sync_tx,
+               .nxpi_sync_rx = ipsec_netif_sync_rx,
+               .nxpi_tx_doorbell = ipsec_netif_tx_doorbell,
+       };
+
+       nexus_attr_t nxa = NULL;
+       err = kern_nexus_attr_create(&nxa);
+       IPSEC_IF_VERIFY(err == 0);
+       if (err != 0) {
+               printf("%s: kern_nexus_attr_create failed: %d\n",
+                          __func__, err);
+               goto failed;
+       }
+
+       uint64_t slot_buffer_size = pcb->ipsec_slot_size;
+       err = kern_nexus_attr_set(nxa, NEXUS_ATTR_SLOT_BUF_SIZE, slot_buffer_size);
+       VERIFY(err == 0);
+
+       // Reset ring size for netif nexus to limit memory usage
+       uint64_t ring_size = pcb->ipsec_netif_ring_size;
+       err = kern_nexus_attr_set(nxa, NEXUS_ATTR_TX_SLOTS, ring_size);
+       VERIFY(err == 0);
+       err = kern_nexus_attr_set(nxa, NEXUS_ATTR_RX_SLOTS, ring_size);
+       VERIFY(err == 0);
+
+       pcb->ipsec_netif_txring_size = ring_size;
+
+       bzero(&pp_init, sizeof (pp_init));
+       pp_init.kbi_version = KERN_PBUFPOOL_CURRENT_VERSION;
+       pp_init.kbi_packets = pcb->ipsec_netif_ring_size * 2;
+       pp_init.kbi_bufsize = pcb->ipsec_slot_size;
+       pp_init.kbi_buf_seg_size = IPSEC_IF_DEFAULT_BUF_SEG_SIZE;
+       pp_init.kbi_max_frags = 1;
+       (void) snprintf((char *)pp_init.kbi_name, sizeof (pp_init.kbi_name),
+           "%s", provider_name);
+
+       err = kern_pbufpool_create(&pp_init, &pp_init, &pcb->ipsec_netif_pp, NULL);
+       if (err != 0) {
+               printf("%s pbufbool create failed, error %d\n", __func__, err);
+               goto failed;
+       }
+
+       err = kern_nexus_controller_register_provider(controller,
+                                                                                                 ipsec_nx_dom_prov,
+                                                                                                 provider_name,
+                                                                                                 &prov_init,
+                                                                                                 sizeof(prov_init),
+                                                                                                 nxa,
+                                                                                                 &pcb->ipsec_nx.if_provider);
+       IPSEC_IF_VERIFY(err == 0);
+       if (err != 0) {
+               printf("%s register provider failed, error %d\n",
+                          __func__, err);
+               goto failed;
+       }
+
+       bzero(&net_init, sizeof(net_init));
+       net_init.nxneti_version = KERN_NEXUS_NET_CURRENT_VERSION;
+       net_init.nxneti_flags = 0;
+       net_init.nxneti_eparams = init_params;
+       net_init.nxneti_lladdr = NULL;
+       net_init.nxneti_prepare = ipsec_netif_prepare;
+       net_init.nxneti_tx_pbufpool = pcb->ipsec_netif_pp;
+       err = kern_nexus_controller_alloc_net_provider_instance(controller,
+                                                                                                                       pcb->ipsec_nx.if_provider,
+                                                                                                                       pcb,
+                                                                                                                       &pcb->ipsec_nx.if_instance,
+                                                                                                                       &net_init,
+                                                                                                                       ifp);
+       IPSEC_IF_VERIFY(err == 0);
+       if (err != 0) {
+               printf("%s alloc_net_provider_instance failed, %d\n",
+                          __func__, err);
+               kern_nexus_controller_deregister_provider(controller,
+                                                                                                 pcb->ipsec_nx.if_provider);
+               uuid_clear(pcb->ipsec_nx.if_provider);
+               goto failed;
+       }
+
+failed:
+       if (nxa) {
+               kern_nexus_attr_destroy(nxa);
+       }
+       if (err && pcb->ipsec_netif_pp != NULL) {
+               kern_pbufpool_destroy(pcb->ipsec_netif_pp);
+               pcb->ipsec_netif_pp = NULL;
+       }
+       return (err);
+}
+
+static void
+ipsec_detach_provider_and_instance(uuid_t provider, uuid_t instance)
+{
+       nexus_controller_t controller = kern_nexus_shared_controller();
+       errno_t err;
+
+       if (!uuid_is_null(instance)) {
+               err = kern_nexus_controller_free_provider_instance(controller,
+                                                                                                                  instance);
+               if (err != 0) {
+                       printf("%s free_provider_instance failed %d\n",
+                                  __func__, err);
+               }
+               uuid_clear(instance);
+       }
+       if (!uuid_is_null(provider)) {
+               err = kern_nexus_controller_deregister_provider(controller,
+                                                                                                               provider);
+               if (err != 0) {
+                       printf("%s deregister_provider %d\n", __func__, err);
+               }
+               uuid_clear(provider);
+       }
+       return;
+}
+
+static void
+ipsec_nexus_detach(struct ipsec_pcb *pcb)
+{
+       ipsec_nx_t nx = &pcb->ipsec_nx;
+       nexus_controller_t controller = kern_nexus_shared_controller();
+       errno_t err;
+
+       if (!uuid_is_null(nx->ms_host)) {
+               err = kern_nexus_ifdetach(controller,
+                                                                 nx->ms_instance,
+                                                                 nx->ms_host);
+               if (err != 0) {
+                       printf("%s: kern_nexus_ifdetach ms host failed %d\n",
+                                  __func__, err);
+               }
+       }
+
+       if (!uuid_is_null(nx->ms_device)) {
+               err = kern_nexus_ifdetach(controller,
+                                                                 nx->ms_instance,
+                                                                 nx->ms_device);
+               if (err != 0) {
+                       printf("%s: kern_nexus_ifdetach ms device failed %d\n",
+                                  __func__, err);
+               }
+       }
+
+       ipsec_detach_provider_and_instance(nx->if_provider,
+                                                                          nx->if_instance);
+       ipsec_detach_provider_and_instance(nx->ms_provider,
+                                                                          nx->ms_instance);
+
+       if (pcb->ipsec_netif_pp != NULL) {
+               kern_pbufpool_destroy(pcb->ipsec_netif_pp);
+               pcb->ipsec_netif_pp = NULL;
+
+       }
+       memset(nx, 0, sizeof(*nx));
+}
+
+static errno_t
+ipsec_create_fs_provider_and_instance(struct ipsec_pcb *pcb,
+                                                                         uint32_t subtype, const char *type_name,
+                                                                         const char *ifname,
+                                                                         uuid_t *provider, uuid_t *instance)
+{
+       nexus_attr_t attr = NULL;
+       nexus_controller_t controller = kern_nexus_shared_controller();
+       uuid_t dom_prov;
+       errno_t err;
+       struct kern_nexus_init init;
+       nexus_name_t    provider_name;
+
+       err = kern_nexus_get_builtin_domain_provider(NEXUS_TYPE_FLOW_SWITCH,
+                                                                                                &dom_prov);
+       IPSEC_IF_VERIFY(err == 0);
+       if (err != 0) {
+               printf("%s can't get %s provider, error %d\n",
+                          __func__, type_name, err);
+               goto failed;
+       }
+
+       err = kern_nexus_attr_create(&attr);
+       IPSEC_IF_VERIFY(err == 0);
+       if (err != 0) {
+               printf("%s: kern_nexus_attr_create failed: %d\n",
+                          __func__, err);
+               goto failed;
+       }
+
+       err = kern_nexus_attr_set(attr, NEXUS_ATTR_EXTENSIONS, subtype);
+       VERIFY(err == 0);
+
+       uint64_t slot_buffer_size = pcb->ipsec_slot_size;
+       err = kern_nexus_attr_set(attr, NEXUS_ATTR_SLOT_BUF_SIZE, slot_buffer_size);
+       VERIFY(err == 0);
+
+       // Reset ring size for flowswitch nexus to limit memory usage. Larger RX than netif.
+       uint64_t tx_ring_size = pcb->ipsec_tx_fsw_ring_size;
+       err = kern_nexus_attr_set(attr, NEXUS_ATTR_TX_SLOTS, tx_ring_size);
+       VERIFY(err == 0);
+       uint64_t rx_ring_size = pcb->ipsec_rx_fsw_ring_size;
+       err = kern_nexus_attr_set(attr, NEXUS_ATTR_RX_SLOTS, rx_ring_size);
+       VERIFY(err == 0);
+
+       snprintf((char *)provider_name, sizeof(provider_name),
+                        "com.apple.%s.%s", type_name, ifname);
+       err = kern_nexus_controller_register_provider(controller,
+                                                                                                 dom_prov,
+                                                                                                 provider_name,
+                                                                                                 NULL,
+                                                                                                 0,
+                                                                                                 attr,
+                                                                                                 provider);
+       kern_nexus_attr_destroy(attr);
+       attr = NULL;
+       IPSEC_IF_VERIFY(err == 0);
+       if (err != 0) {
+               printf("%s register %s provider failed, error %d\n",
+                          __func__, type_name, err);
+               goto failed;
+       }
+       bzero(&init, sizeof (init));
+       init.nxi_version = KERN_NEXUS_CURRENT_VERSION;
+       err = kern_nexus_controller_alloc_provider_instance(controller,
+                                                                                                               *provider,
+                                                                                                               NULL,
+                                                                                                               instance, &init);
+       IPSEC_IF_VERIFY(err == 0);
+       if (err != 0) {
+               printf("%s alloc_provider_instance %s failed, %d\n",
+                          __func__, type_name, err);
+               kern_nexus_controller_deregister_provider(controller,
+                                                                                                 *provider);
+               uuid_clear(*provider);
+       }
+failed:
+       return (err);
+}
+
+static errno_t
+ipsec_multistack_attach(struct ipsec_pcb *pcb)
+{
+       nexus_controller_t controller = kern_nexus_shared_controller();
+       errno_t err = 0;
+       ipsec_nx_t nx = &pcb->ipsec_nx;
+
+       // Allocate multistack flowswitch
+       err = ipsec_create_fs_provider_and_instance(pcb,
+                                                                                               NEXUS_EXTENSION_FSW_TYPE_MULTISTACK,
+                                                                                               "multistack",
+                                                                                               pcb->ipsec_ifp->if_xname,
+                                                                                               &nx->ms_provider,
+                                                                                               &nx->ms_instance);
+       if (err != 0) {
+               printf("%s: failed to create bridge provider and instance\n",
+                          __func__);
+               goto failed;
+       }
+
+       // Attach multistack to device port
+       err = kern_nexus_ifattach(controller, nx->ms_instance,
+                                                         NULL, nx->if_instance,
+                                                         FALSE, &nx->ms_device);
+       if (err != 0) {
+               printf("%s kern_nexus_ifattach ms device %d\n", __func__, err);
+               goto failed;
+       }
+
+       // Attach multistack to host port
+       err = kern_nexus_ifattach(controller, nx->ms_instance,
+                                                         NULL, nx->if_instance,
+                                                         TRUE, &nx->ms_host);
+       if (err != 0) {
+               printf("%s kern_nexus_ifattach ms host %d\n", __func__, err);
+               goto failed;
+       }
 
-/* Protocol handlers */
-static errno_t ipsec_attach_proto(ifnet_t interface, protocol_family_t proto);
-static errno_t ipsec_proto_input(ifnet_t interface, protocol_family_t protocol,
-                                                                 mbuf_t m, char *frame_header);
-static errno_t ipsec_proto_pre_output(ifnet_t interface, protocol_family_t protocol,
-                                                                         mbuf_t *packet, const struct sockaddr *dest, void *route,
-                                                                         char *frame_type, char *link_layer_dest);
+       // Extract the agent UUID and save for later
+       struct kern_nexus *multistack_nx = nx_find(nx->ms_instance, false);
+       if (multistack_nx != NULL) {
+               struct nx_flowswitch *flowswitch = NX_FSW_PRIVATE(multistack_nx);
+               if (flowswitch != NULL) {
+                       FSW_RLOCK(flowswitch);
+                       struct fsw_ms_context *ms_context = (struct fsw_ms_context *)flowswitch->fsw_ops_private;
+                       if (ms_context != NULL) {
+                               uuid_copy(nx->ms_agent, ms_context->mc_agent_uuid);
+                       } else {
+                               printf("ipsec_multistack_attach - fsw_ms_context is NULL\n");
+                       }
+                       FSW_UNLOCK(flowswitch);
+               } else {
+                       printf("ipsec_multistack_attach - flowswitch is NULL\n");
+               }
+               nx_release(multistack_nx);
+       } else {
+               printf("ipsec_multistack_attach - unable to find multistack nexus\n");
+       }
 
-static kern_ctl_ref    ipsec_kctlref;
-static u_int32_t       ipsec_family;
-static OSMallocTag     ipsec_malloc_tag;
-static SInt32          ipsec_ifcount = 0;
+       return (0);
 
-#define IPSECQ_MAXLEN 256
+failed:
+       ipsec_nexus_detach(pcb);
+
+       errno_t detach_error = 0;
+       if ((detach_error = ifnet_detach(pcb->ipsec_ifp)) != 0) {
+               panic("ipsec_multistack_attach - ifnet_detach failed: %d\n", detach_error);
+               /* NOT REACHED */
+       }
 
-/* Prepend length */
-static void*
-ipsec_alloc(size_t size)
+       return (err);
+}
+
+#pragma mark Kernel Pipe Nexus
+
+static errno_t
+ipsec_register_kernel_pipe_nexus(void)
 {
-       size_t  *mem = OSMalloc(size + sizeof(size_t), ipsec_malloc_tag);
-       
-       if (mem) {
-               *mem = size + sizeof(size_t);
-               mem++;
+       nexus_attr_t nxa = NULL;
+       errno_t result;
+
+       lck_mtx_lock(&ipsec_lock);
+       if (ipsec_ncd_refcount++) {
+               lck_mtx_unlock(&ipsec_lock);
+               return 0;
        }
-       
-       return (void*)mem;
+
+       result = kern_nexus_controller_create(&ipsec_ncd);
+       if (result) {
+               printf("%s: kern_nexus_controller_create failed: %d\n",
+                          __FUNCTION__, result);
+               goto done;
+       }
+
+       uuid_t dom_prov;
+       result = kern_nexus_get_builtin_domain_provider(
+                                                                                                       NEXUS_TYPE_KERNEL_PIPE, &dom_prov);
+       if (result) {
+               printf("%s: kern_nexus_get_builtin_domain_provider failed: %d\n",
+                          __FUNCTION__, result);
+               goto done;
+       }
+
+       struct kern_nexus_provider_init prov_init = {
+               .nxpi_version = KERN_NEXUS_DOMAIN_PROVIDER_CURRENT_VERSION,
+               .nxpi_flags = NXPIF_VIRTUAL_DEVICE,
+               .nxpi_pre_connect = ipsec_nexus_pre_connect,
+               .nxpi_connected = ipsec_nexus_connected,
+               .nxpi_pre_disconnect = ipsec_nexus_pre_disconnect,
+               .nxpi_disconnected = ipsec_nexus_disconnected,
+               .nxpi_ring_init = ipsec_kpipe_ring_init,
+               .nxpi_ring_fini = ipsec_kpipe_ring_fini,
+               .nxpi_slot_init = NULL,
+               .nxpi_slot_fini = NULL,
+               .nxpi_sync_tx = ipsec_kpipe_sync_tx,
+               .nxpi_sync_rx = ipsec_kpipe_sync_rx,
+               .nxpi_tx_doorbell = NULL,
+       };
+
+       result = kern_nexus_attr_create(&nxa);
+       if (result) {
+               printf("%s: kern_nexus_attr_create failed: %d\n",
+                          __FUNCTION__, result);
+               goto done;
+       }
+
+       uint64_t slot_buffer_size = IPSEC_IF_DEFAULT_SLOT_SIZE;
+       result = kern_nexus_attr_set(nxa, NEXUS_ATTR_SLOT_BUF_SIZE, slot_buffer_size);
+       VERIFY(result == 0);
+
+       // Reset ring size for kernel pipe nexus to limit memory usage
+       uint64_t ring_size = if_ipsec_ring_size;
+       result = kern_nexus_attr_set(nxa, NEXUS_ATTR_TX_SLOTS, ring_size);
+       VERIFY(result == 0);
+       result = kern_nexus_attr_set(nxa, NEXUS_ATTR_RX_SLOTS, ring_size);
+       VERIFY(result == 0);
+
+       result = kern_nexus_controller_register_provider(ipsec_ncd,
+                                                                                                        dom_prov,
+                                                                                                        (const uint8_t *)"com.apple.nexus.ipsec.kpipe",
+                                                                                                        &prov_init,
+                                                                                                        sizeof(prov_init),
+                                                                                                        nxa,
+                                                                                                        &ipsec_kpipe_uuid);
+       if (result) {
+               printf("%s: kern_nexus_controller_register_provider failed: %d\n",
+                          __FUNCTION__, result);
+               goto done;
+       }
+
+done:
+       if (nxa) {
+               kern_nexus_attr_destroy(nxa);
+       }
+
+       if (result) {
+               if (ipsec_ncd) {
+                       kern_nexus_controller_destroy(ipsec_ncd);
+                       ipsec_ncd = NULL;
+               }
+               ipsec_ncd_refcount = 0;
+       }
+
+       lck_mtx_unlock(&ipsec_lock);
+
+       return result;
 }
 
 static void
-ipsec_free(void *ptr)
+ipsec_unregister_kernel_pipe_nexus(void)
 {
-       size_t  *size = ptr;
-       size--;
-       OSFree(size, *size, ipsec_malloc_tag);
+       lck_mtx_lock(&ipsec_lock);
+
+       VERIFY(ipsec_ncd_refcount > 0);
+
+       if (--ipsec_ncd_refcount == 0) {
+               kern_nexus_controller_destroy(ipsec_ncd);
+               ipsec_ncd = NULL;
+       }
+
+       lck_mtx_unlock(&ipsec_lock);
 }
 
-errno_t
-ipsec_register_control(void)
+// For use by socket option, not internally
+static errno_t
+ipsec_disable_channel(struct ipsec_pcb *pcb)
 {
-       struct kern_ctl_reg     kern_ctl;
-       errno_t                         result = 0;
-       
-       /* Create a tag to allocate memory */
-       ipsec_malloc_tag = OSMalloc_Tagalloc(IPSEC_CONTROL_NAME, OSMT_DEFAULT);
-       
-       /* Find a unique value for our interface family */
-       result = mbuf_tag_id_find(IPSEC_CONTROL_NAME, &ipsec_family);
-       if (result != 0) {
-               printf("ipsec_register_control - mbuf_tag_id_find_internal failed: %d\n", result);
-               return result;
+       errno_t result;
+       int enabled;
+       uuid_t uuid;
+
+       lck_rw_lock_exclusive(&pcb->ipsec_pcb_lock);
+
+       enabled = pcb->ipsec_kpipe_enabled;
+       uuid_copy(uuid, pcb->ipsec_kpipe_uuid);
+
+       VERIFY(uuid_is_null(pcb->ipsec_kpipe_uuid) == !enabled);
+
+       pcb->ipsec_kpipe_enabled = 0;
+       uuid_clear(pcb->ipsec_kpipe_uuid);
+
+       lck_rw_unlock_exclusive(&pcb->ipsec_pcb_lock);
+
+       if (enabled) {
+               result = kern_nexus_controller_free_provider_instance(ipsec_ncd, uuid);
+       } else {
+               result = ENXIO;
        }
-       
-       bzero(&kern_ctl, sizeof(kern_ctl));
-       strncpy(kern_ctl.ctl_name, IPSEC_CONTROL_NAME, sizeof(kern_ctl.ctl_name));
-       kern_ctl.ctl_name[sizeof(kern_ctl.ctl_name) - 1] = 0;
-       kern_ctl.ctl_flags = CTL_FLAG_PRIVILEGED; /* Require root */
-       kern_ctl.ctl_sendsize = 64 * 1024;
-       kern_ctl.ctl_recvsize = 64 * 1024;
-       kern_ctl.ctl_connect = ipsec_ctl_connect;
-       kern_ctl.ctl_disconnect = ipsec_ctl_disconnect;
-       kern_ctl.ctl_send = ipsec_ctl_send;
-       kern_ctl.ctl_setopt = ipsec_ctl_setopt;
-       kern_ctl.ctl_getopt = ipsec_ctl_getopt;
-       
-       result = ctl_register(&kern_ctl, &ipsec_kctlref);
-       if (result != 0) {
-               printf("ipsec_register_control - ctl_register failed: %d\n", result);
+
+       if (!result) {
+               if (pcb->ipsec_kpipe_pp != NULL) {
+                       kern_pbufpool_destroy(pcb->ipsec_kpipe_pp);
+                       pcb->ipsec_kpipe_pp = NULL;
+               }
+               ipsec_unregister_kernel_pipe_nexus();
+       }
+
+       return result;
+}
+
+static errno_t
+ipsec_enable_channel(struct ipsec_pcb *pcb, struct proc *proc)
+{
+       struct kern_nexus_init init;
+       struct kern_pbufpool_init pp_init;
+       errno_t result;
+
+       kauth_cred_t cred = kauth_cred_get();
+       result = priv_check_cred(cred, PRIV_SKYWALK_REGISTER_KERNEL_PIPE, 0);
+       if (result) {
                return result;
        }
-       
-       /* Register the protocol plumbers */
-       if ((result = proto_register_plumber(PF_INET, ipsec_family,
-                                                                                ipsec_attach_proto, NULL)) != 0) {
-               printf("ipsec_register_control - proto_register_plumber(PF_INET, %d) failed: %d\n",
-                          ipsec_family, result);
-               ctl_deregister(ipsec_kctlref);
+
+       result = ipsec_register_kernel_pipe_nexus();
+       if (result) {
                return result;
        }
+
+       VERIFY(ipsec_ncd);
+
+       lck_rw_lock_exclusive(&pcb->ipsec_pcb_lock);
+
+       /* ipsec driver doesn't support channels without a netif */
+       if (!pcb->ipsec_use_netif) {
+               result = EOPNOTSUPP;
+               goto done;
+       }
+
+       if (pcb->ipsec_kpipe_enabled) {
+               result = EEXIST; // return success instead?
+               goto done;
+       }
+
+       bzero(&pp_init, sizeof (pp_init));
+       pp_init.kbi_version = KERN_PBUFPOOL_CURRENT_VERSION;
+       pp_init.kbi_packets = pcb->ipsec_netif_ring_size * 2;
+       pp_init.kbi_bufsize = pcb->ipsec_slot_size;
+       pp_init.kbi_buf_seg_size = IPSEC_IF_DEFAULT_BUF_SEG_SIZE;
+       pp_init.kbi_max_frags = 1;
+       pp_init.kbi_flags |= KBIF_QUANTUM;
+       (void) snprintf((char *)pp_init.kbi_name, sizeof (pp_init.kbi_name),
+           "com.apple.kpipe.%s", pcb->ipsec_if_xname);
+
+       result = kern_pbufpool_create(&pp_init, &pp_init, &pcb->ipsec_kpipe_pp,
+           NULL);
+       if (result != 0) {
+               printf("%s pbufbool create failed, error %d\n", __func__, result);
+               goto done;
+       }
+
+       VERIFY(uuid_is_null(pcb->ipsec_kpipe_uuid));
+       bzero(&init, sizeof (init));
+       init.nxi_version = KERN_NEXUS_CURRENT_VERSION;
+       init.nxi_tx_pbufpool = pcb->ipsec_kpipe_pp;
+       result = kern_nexus_controller_alloc_provider_instance(ipsec_ncd,
+                                                                                                                  ipsec_kpipe_uuid, pcb, &pcb->ipsec_kpipe_uuid, &init);
+       if (result) {
+               goto done;
+       }
+
+       nexus_port_t port = NEXUS_PORT_KERNEL_PIPE_CLIENT;
+       result = kern_nexus_controller_bind_provider_instance(ipsec_ncd,
+                                                                                                                 pcb->ipsec_kpipe_uuid, &port,
+                                                                                                                 proc_pid(proc), NULL, NULL, 0, NEXUS_BIND_PID);
+       if (result) {
+               kern_nexus_controller_free_provider_instance(ipsec_ncd,
+                                                                                                        pcb->ipsec_kpipe_uuid);
+               uuid_clear(pcb->ipsec_kpipe_uuid);
+               goto done;
+       }
+
+       pcb->ipsec_kpipe_enabled = 1;
+
+done:
+       lck_rw_unlock_exclusive(&pcb->ipsec_pcb_lock);
        
-       /* Register the protocol plumbers */
-       if ((result = proto_register_plumber(PF_INET6, ipsec_family,
-                                                                                ipsec_attach_proto, NULL)) != 0) {
-               proto_unregister_plumber(PF_INET, ipsec_family);
-               ctl_deregister(ipsec_kctlref);
-               printf("ipsec_register_control - proto_register_plumber(PF_INET6, %d) failed: %d\n",
-                          ipsec_family, result);
-               return result;
+       if (result) {
+               if (pcb->ipsec_kpipe_pp != NULL) {
+                       kern_pbufpool_destroy(pcb->ipsec_kpipe_pp);
+                       pcb->ipsec_kpipe_pp = NULL;
+               }
+               ipsec_unregister_kernel_pipe_nexus();
        }
        
-       return 0;
+       return result;
 }
 
-/* Helpers */
-int
-ipsec_interface_isvalid (ifnet_t interface)
-{
-    struct ipsec_pcb *pcb = NULL;
-    
-    if (interface == NULL)
-        return 0;
-    
-    pcb = ifnet_softc(interface);
-    
-    if (pcb == NULL)
-        return 0;
-    
-    /* When ctl disconnects, ipsec_unit is set to 0 */
-    if (pcb->ipsec_unit == 0)
-        return 0;
-    
-    return 1;
-}
+#endif // IPSEC_NEXUS
+
 
 /* Kernel control functions */
 
+static inline void
+ipsec_free_pcb(struct ipsec_pcb *pcb, bool in_list)
+{
+#if IPSEC_NEXUS
+       mbuf_freem_list(pcb->ipsec_input_chain);
+       lck_mtx_destroy(&pcb->ipsec_input_chain_lock, ipsec_lck_grp);
+#endif // IPSEC_NEXUS
+       lck_rw_destroy(&pcb->ipsec_pcb_lock, ipsec_lck_grp);
+       if (in_list) {
+               lck_mtx_lock(&ipsec_lock);
+               TAILQ_REMOVE(&ipsec_head, pcb, ipsec_chain);
+               lck_mtx_unlock(&ipsec_lock);
+       }
+       zfree(ipsec_pcb_zone, pcb);
+}
+
 static errno_t
-ipsec_ctl_connect(kern_ctl_ref         kctlref,
-                                 struct sockaddr_ctl   *sac,
-                                 void                          **unitinfo)
+ipsec_ctl_bind(kern_ctl_ref kctlref,
+                          struct sockaddr_ctl *sac,
+                          void **unitinfo)
 {
-       struct ifnet_init_eparams       ipsec_init;
-       struct ipsec_pcb                                *pcb;
-       errno_t                                         result;
-       struct ifnet_stats_param        stats;
-       
-       /* kernel control allocates, interface frees */
-       pcb = ipsec_alloc(sizeof(*pcb));
-       if (pcb == NULL)
-               return ENOMEM;
-       
+       struct ipsec_pcb *pcb = zalloc(ipsec_pcb_zone);
+       memset(pcb, 0, sizeof(*pcb));
+
        /* Setup the protocol control block */
-       bzero(pcb, sizeof(*pcb));
        *unitinfo = pcb;
        pcb->ipsec_ctlref = kctlref;
        pcb->ipsec_unit = sac->sc_unit;
-       
-       printf("ipsec_ctl_connect: creating interface ipsec%d\n", pcb->ipsec_unit - 1);
-       
+       pcb->ipsec_output_service_class = MBUF_SC_OAM;
+
+#if IPSEC_NEXUS
+       pcb->ipsec_use_netif = false;
+       pcb->ipsec_slot_size = IPSEC_IF_DEFAULT_SLOT_SIZE;
+       pcb->ipsec_netif_ring_size = IPSEC_IF_DEFAULT_RING_SIZE;
+       pcb->ipsec_tx_fsw_ring_size = IPSEC_IF_DEFAULT_TX_FSW_RING_SIZE;
+       pcb->ipsec_rx_fsw_ring_size = IPSEC_IF_DEFAULT_RX_FSW_RING_SIZE;
+#endif // IPSEC_NEXUS
+
+       lck_rw_init(&pcb->ipsec_pcb_lock, ipsec_lck_grp, ipsec_lck_attr);
+#if IPSEC_NEXUS
+       lck_mtx_init(&pcb->ipsec_input_chain_lock, ipsec_lck_grp, ipsec_lck_attr);
+#endif // IPSEC_NEXUS
+
+       return (0);
+}
+
+static errno_t
+ipsec_ctl_connect(kern_ctl_ref kctlref,
+                                 struct sockaddr_ctl *sac,
+                                 void **unitinfo)
+{
+       struct ifnet_init_eparams ipsec_init = {};
+       errno_t result = 0;
+
+       if (*unitinfo == NULL) {
+               (void)ipsec_ctl_bind(kctlref, sac, unitinfo);
+       }
+
+       struct ipsec_pcb *pcb = *unitinfo;
+
+       lck_mtx_lock(&ipsec_lock);
+
+       /* Find some open interface id */
+       u_int32_t chosen_unique_id = 1;
+       struct ipsec_pcb *next_pcb = TAILQ_LAST(&ipsec_head, ipsec_list);
+       if (next_pcb != NULL) {
+               /* List was not empty, add one to the last item */
+               chosen_unique_id = next_pcb->ipsec_unique_id + 1;
+               next_pcb = NULL;
+
+               /*
+                * If this wrapped the id number, start looking at
+                * the front of the list for an unused id.
+                */
+               if (chosen_unique_id == 0) {
+                       /* Find the next unused ID */
+                       chosen_unique_id = 1;
+                       TAILQ_FOREACH(next_pcb, &ipsec_head, ipsec_chain) {
+                               if (next_pcb->ipsec_unique_id > chosen_unique_id) {
+                                       /* We found a gap */
+                                       break;
+                               }
+
+                               chosen_unique_id = next_pcb->ipsec_unique_id + 1;
+                       }
+               }
+       }
+
+       pcb->ipsec_unique_id = chosen_unique_id;
+
+       if (next_pcb != NULL) {
+               TAILQ_INSERT_BEFORE(next_pcb, pcb, ipsec_chain);
+       } else {
+               TAILQ_INSERT_TAIL(&ipsec_head, pcb, ipsec_chain);
+       }
+       lck_mtx_unlock(&ipsec_lock);
+
+       snprintf(pcb->ipsec_if_xname, sizeof(pcb->ipsec_if_xname), "ipsec%d", pcb->ipsec_unit - 1);
+       snprintf(pcb->ipsec_unique_name, sizeof(pcb->ipsec_unique_name), "ipsecid%d", pcb->ipsec_unique_id - 1);
+       printf("ipsec_ctl_connect: creating interface %s (id %s)\n", pcb->ipsec_if_xname, pcb->ipsec_unique_name);
+
        /* Create the interface */
        bzero(&ipsec_init, sizeof(ipsec_init));
        ipsec_init.ver = IFNET_INIT_CURRENT_VERSION;
        ipsec_init.len = sizeof (ipsec_init);
+
+#if IPSEC_NEXUS
+       if (pcb->ipsec_use_netif) {
+               ipsec_init.flags = (IFNET_INIT_SKYWALK_NATIVE | IFNET_INIT_NX_NOAUTO);
+       } else
+#endif // IPSEC_NEXUS
+       {
+               ipsec_init.flags = IFNET_INIT_NX_NOAUTO;
+               ipsec_init.start = ipsec_start;
+       }
        ipsec_init.name = "ipsec";
-    ipsec_init.start = ipsec_start;
-    ipsec_init.sndq_maxlen = IPSECQ_MAXLEN;
        ipsec_init.unit = pcb->ipsec_unit - 1;
+       ipsec_init.uniqueid = pcb->ipsec_unique_name;
+       ipsec_init.uniqueid_len = strlen(pcb->ipsec_unique_name);
        ipsec_init.family = ipsec_family;
+       ipsec_init.subfamily = IFNET_SUBFAMILY_IPSEC;
        ipsec_init.type = IFT_OTHER;
        ipsec_init.demux = ipsec_demux;
        ipsec_init.add_proto = ipsec_add_proto;
@@ -228,45 +2288,56 @@ ipsec_ctl_connect(kern_ctl_ref           kctlref,
        ipsec_init.softc = pcb;
        ipsec_init.ioctl = ipsec_ioctl;
        ipsec_init.detach = ipsec_detached;
-       
-       result = ifnet_allocate_extended(&ipsec_init, &pcb->ipsec_ifp);
-       if (result != 0) {
-               printf("ipsec_ctl_connect - ifnet_allocate failed: %d\n", result);
-               ipsec_free(pcb);
-               return result;
-       }
-       OSIncrementAtomic(&ipsec_ifcount);
-       
-       /* Set flags and additional information. */
-       ifnet_set_mtu(pcb->ipsec_ifp, 1500);
-       ifnet_set_flags(pcb->ipsec_ifp, IFF_UP | IFF_MULTICAST | IFF_POINTOPOINT, 0xffff);
-       
-       /* The interface must generate its own IPv6 LinkLocal address,
-        * if possible following the recommendation of RFC2472 to the 64bit interface ID
-        */
-       ifnet_set_eflags(pcb->ipsec_ifp, IFEF_NOAUTOIPV6LL, IFEF_NOAUTOIPV6LL);
-       
-       /* Reset the stats in case as the interface may have been recycled */
-       bzero(&stats, sizeof(struct ifnet_stats_param));
-       ifnet_set_stat(pcb->ipsec_ifp, &stats);
-       
-       /* Attach the interface */
-       result = ifnet_attach(pcb->ipsec_ifp, NULL);
-       if (result != 0) {
-               printf("ipsec_ctl_connect - ifnet_allocate failed: %d\n", result);
-               ifnet_release(pcb->ipsec_ifp);
-               ipsec_free(pcb);
+
+#if IPSEC_NEXUS
+       if (pcb->ipsec_use_netif) {
+               result = ipsec_nexus_ifattach(pcb, &ipsec_init, &pcb->ipsec_ifp);
+               if (result != 0) {
+                       printf("ipsec_ctl_connect - ipsec_nexus_ifattach failed: %d\n", result);
+                       ipsec_free_pcb(pcb, true);
+                       *unitinfo = NULL;
+                       return result;
+               }
+
+               result = ipsec_multistack_attach(pcb);
+               if (result != 0) {
+                       printf("ipsec_ctl_connect - ipsec_multistack_attach failed: %d\n", result);
+                       *unitinfo = NULL;
+                       return result;
+               }
+
+               /* Attach to bpf */
+               bpfattach(pcb->ipsec_ifp, DLT_RAW, 0);
+       } else
+#endif // IPSEC_NEXUS
+       {
+               result = ifnet_allocate_extended(&ipsec_init, &pcb->ipsec_ifp);
+               if (result != 0) {
+                       printf("ipsec_ctl_connect - ifnet_allocate failed: %d\n", result);
+                       ipsec_free_pcb(pcb, true);
+                       *unitinfo = NULL;
+                       return result;
+               }
+               ipsec_ifnet_set_attrs(pcb->ipsec_ifp);
+
+               /* Attach the interface */
+               result = ifnet_attach(pcb->ipsec_ifp, NULL);
+               if (result != 0) {
+                       printf("ipsec_ctl_connect - ifnet_attach failed: %d\n", result);
+                       ifnet_release(pcb->ipsec_ifp);
+                       ipsec_free_pcb(pcb, true);
+                       *unitinfo = NULL;
+                       return (result);
+               }
+
+               /* Attach to bpf */
+               bpfattach(pcb->ipsec_ifp, DLT_NULL, 0);
        }
-       
-       /* Attach to bpf */
-       if (result == 0)
-               bpfattach(pcb->ipsec_ifp, DLT_NULL, 4);
-       
+
        /* The interfaces resoures allocated, mark it as running */
-       if (result == 0)
-               ifnet_set_flags(pcb->ipsec_ifp, IFF_RUNNING, IFF_RUNNING);
-       
-       return result;
+       ifnet_set_flags(pcb->ipsec_ifp, IFF_RUNNING, IFF_RUNNING);
+
+       return (0);
 }
 
 static errno_t
@@ -423,26 +2494,115 @@ ipsec_ctl_disconnect(__unused kern_ctl_ref      kctlref,
                                         __unused u_int32_t             unit,
                                         void                                   *unitinfo)
 {
-       struct ipsec_pcb        *pcb = unitinfo;
-       ifnet_t                 ifp = pcb->ipsec_ifp;
-       errno_t                 result = 0;
-       
+       struct ipsec_pcb *pcb = unitinfo;
+       ifnet_t ifp = NULL;
+       errno_t result = 0;
+
+       if (pcb == NULL) {
+               return EINVAL;
+       }
+
+#if IPSEC_NEXUS
+       // Tell the nexus to stop all rings
+       if (pcb->ipsec_netif_nexus != NULL) {
+               kern_nexus_stop(pcb->ipsec_netif_nexus);
+       }
+#endif // IPSEC_NEXUS
+
+       lck_rw_lock_exclusive(&pcb->ipsec_pcb_lock);
+
+#if IPSEC_NEXUS
+       uuid_t kpipe_uuid;
+       uuid_copy(kpipe_uuid, pcb->ipsec_kpipe_uuid);
+       uuid_clear(pcb->ipsec_kpipe_uuid);
+       pcb->ipsec_kpipe_enabled = FALSE;
+#endif // IPSEC_NEXUS
+
        pcb->ipsec_ctlref = NULL;
-       pcb->ipsec_unit = 0;
-       
-       /*
-        * We want to do everything in our power to ensure that the interface
-        * really goes away when the socket is closed. We must remove IP/IPv6
-        * addresses and detach the protocols. Finally, we can remove and
-        * release the interface.
-        */
-    key_delsp_for_ipsec_if(ifp);
-    
-       ipsec_cleanup_family(ifp, AF_INET);
-       ipsec_cleanup_family(ifp, AF_INET6);
-       
-       if ((result = ifnet_detach(ifp)) != 0) {
-               printf("ipsec_ctl_disconnect - ifnet_detach failed: %d\n", result);
+
+       ifp = pcb->ipsec_ifp;
+       if (ifp != NULL) {
+#if IPSEC_NEXUS
+               if (pcb->ipsec_netif_nexus != NULL) {
+                       /*
+                        * Quiesce the interface and flush any pending outbound packets.
+                        */
+                       if_down(ifp);
+
+                       /* Increment refcnt, but detach interface */
+                       ifnet_incr_iorefcnt(ifp);
+                       if ((result = ifnet_detach(ifp)) != 0) {
+                               panic("ipsec_ctl_disconnect - ifnet_detach failed: %d\n", result);
+                               /* NOT REACHED */
+                       }
+
+                       /*
+                        * We want to do everything in our power to ensure that the interface
+                        * really goes away when the socket is closed. We must remove IP/IPv6
+                        * addresses and detach the protocols. Finally, we can remove and
+                        * release the interface.
+                        */
+                       key_delsp_for_ipsec_if(ifp);
+
+                       ipsec_cleanup_family(ifp, AF_INET);
+                       ipsec_cleanup_family(ifp, AF_INET6);
+
+                       lck_rw_unlock_exclusive(&pcb->ipsec_pcb_lock);
+
+                       if (!uuid_is_null(kpipe_uuid)) {
+                               if (kern_nexus_controller_free_provider_instance(ipsec_ncd, kpipe_uuid) == 0) {
+                                       if (pcb->ipsec_kpipe_pp != NULL) {
+                                               kern_pbufpool_destroy(pcb->ipsec_kpipe_pp);
+                                               pcb->ipsec_kpipe_pp = NULL;
+                                       }
+                                       ipsec_unregister_kernel_pipe_nexus();
+                               }
+                       }
+                       ipsec_nexus_detach(pcb);
+
+                       /* Decrement refcnt to finish detaching and freeing */
+                       ifnet_decr_iorefcnt(ifp);
+               } else
+#endif // IPSEC_NEXUS
+               {
+                       lck_rw_unlock_exclusive(&pcb->ipsec_pcb_lock);
+
+#if IPSEC_NEXUS
+                       if (!uuid_is_null(kpipe_uuid)) {
+                               if (kern_nexus_controller_free_provider_instance(ipsec_ncd, kpipe_uuid) == 0) {
+                                       if (pcb->ipsec_kpipe_pp != NULL) {
+                                               kern_pbufpool_destroy(pcb->ipsec_kpipe_pp);
+                                               pcb->ipsec_kpipe_pp = NULL;
+                                       }
+                                       ipsec_unregister_kernel_pipe_nexus();
+                               }
+                       }
+#endif // IPSEC_NEXUS
+
+                       /*
+                        * We want to do everything in our power to ensure that the interface
+                        * really goes away when the socket is closed. We must remove IP/IPv6
+                        * addresses and detach the protocols. Finally, we can remove and
+                        * release the interface.
+                        */
+                       key_delsp_for_ipsec_if(ifp);
+
+                       ipsec_cleanup_family(ifp, AF_INET);
+                       ipsec_cleanup_family(ifp, AF_INET6);
+
+                       /*
+                        * Detach now; ipsec_detach() will be called asynchronously once
+                        * the I/O reference count drops to 0.  There we will invoke
+                        * ifnet_release().
+                        */
+                       if ((result = ifnet_detach(ifp)) != 0) {
+                               printf("ipsec_ctl_disconnect - ifnet_detach failed: %d\n", result);
+                       }
+               }
+       } else {
+               // Bound, but not connected
+               lck_rw_unlock_exclusive(&pcb->ipsec_pcb_lock);
+               ipsec_free_pcb(pcb, false);
        }
        
        return 0;
@@ -476,6 +2636,7 @@ ipsec_ctl_setopt(__unused kern_ctl_ref     kctlref,
                case IPSEC_OPT_FLAGS:
                case IPSEC_OPT_EXT_IFDATA_STATS:
                case IPSEC_OPT_SET_DELEGATE_INTERFACE:
+               case IPSEC_OPT_OUTPUT_TRAFFIC_CLASS:
                        if (kauth_cred_issuser(kauth_cred_get()) == 0) {
                                return EPERM;
                        }
@@ -484,10 +2645,11 @@ ipsec_ctl_setopt(__unused kern_ctl_ref   kctlref,
        
        switch (opt) {
                case IPSEC_OPT_FLAGS:
-                       if (len != sizeof(u_int32_t))
+                       if (len != sizeof(u_int32_t)) {
                                result = EMSGSIZE;
-                       else
+                       } else {
                                pcb->ipsec_flags = *(u_int32_t *)data;
+                       }
                        break;
                        
                case IPSEC_OPT_EXT_IFDATA_STATS:
@@ -495,6 +2657,11 @@ ipsec_ctl_setopt(__unused kern_ctl_ref    kctlref,
                                result = EMSGSIZE;
                                break;
                        }
+                       if (pcb->ipsec_ifp == NULL) {
+                               // Only can set after connecting
+                               result = EINVAL;
+                               break;
+                       }
                        pcb->ipsec_ext_ifdata_stats = (*(int *)data) ? 1 : 0;
                        break;
                        
@@ -506,6 +2673,11 @@ ipsec_ctl_setopt(__unused kern_ctl_ref    kctlref,
                                result = EINVAL;
                                break;
                        }
+                       if (pcb->ipsec_ifp == NULL) {
+                               // Only can set after connecting
+                               result = EINVAL;
+                               break;
+                       }
                        if (!pcb->ipsec_ext_ifdata_stats) {
                                result = EINVAL;
                                break;
@@ -527,12 +2699,21 @@ ipsec_ctl_setopt(__unused kern_ctl_ref   kctlref,
                                result = EMSGSIZE;
                                break;
                        }
+                       if (pcb->ipsec_ifp == NULL) {
+                               // Only can set after connecting
+                               result = EINVAL;
+                               break;
+                       }
                        if (len != 0) {   /* if len==0, del_ifp will be NULL causing the delegate to be removed */
                                bcopy(data, name, len);
                                name[len] = 0;
                                result = ifnet_find_by_name(name, &del_ifp);
                        }
                        if (result == 0) {
+                               printf("%s IPSEC_OPT_SET_DELEGATE_INTERFACE %s to %s\n",
+                                       __func__, pcb->ipsec_ifp->if_xname, 
+                                       del_ifp ? del_ifp->if_xname : "NULL");
+
                                result = ifnet_set_delegate(pcb->ipsec_ifp, del_ifp);
                                if (del_ifp)
                                        ifnet_release(del_ifp);
@@ -540,6 +2721,182 @@ ipsec_ctl_setopt(__unused kern_ctl_ref   kctlref,
                        break;
                }
                        
+               case IPSEC_OPT_OUTPUT_TRAFFIC_CLASS: {
+                       if (len != sizeof(int)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       if (pcb->ipsec_ifp == NULL) {
+                               // Only can set after connecting
+                               result = EINVAL;
+                               break;
+                       }
+                       mbuf_svc_class_t output_service_class = so_tc2msc(*(int *)data);
+                       if (output_service_class == MBUF_SC_UNSPEC) {
+                               pcb->ipsec_output_service_class = MBUF_SC_OAM;
+                       } else {
+                               pcb->ipsec_output_service_class = output_service_class;
+                       }
+                       printf("%s IPSEC_OPT_OUTPUT_TRAFFIC_CLASS %s svc %d\n",
+                               __func__, pcb->ipsec_ifp->if_xname, 
+                               pcb->ipsec_output_service_class);
+                       break;
+               }
+
+#if IPSEC_NEXUS
+               case IPSEC_OPT_ENABLE_CHANNEL: {
+                       if (len != sizeof(int)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       if (pcb->ipsec_ifp == NULL) {
+                               // Only can set after connecting
+                               result = EINVAL;
+                               break;
+                       }
+                       if (*(int *)data) {
+                               result = ipsec_enable_channel(pcb, current_proc());
+                       } else {
+                               result = ipsec_disable_channel(pcb);
+                       }
+                       break;
+               }
+
+               case IPSEC_OPT_ENABLE_FLOWSWITCH: {
+                       if (len != sizeof(int)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       if (pcb->ipsec_ifp == NULL) {
+                               // Only can set after connecting
+                               result = EINVAL;
+                               break;
+                       }
+                       if (!if_is_netagent_enabled()) {
+                               result = ENOTSUP;
+                               break;
+                       }
+                       if (uuid_is_null(pcb->ipsec_nx.ms_agent)) {
+                               result = ENOENT;
+                               break;
+                       }
+
+                       if (*(int *)data) {
+                               if_add_netagent(pcb->ipsec_ifp, pcb->ipsec_nx.ms_agent);
+                               pcb->ipsec_needs_netagent = true;
+                       } else {
+                               pcb->ipsec_needs_netagent = false;
+                               if_delete_netagent(pcb->ipsec_ifp, pcb->ipsec_nx.ms_agent);
+                       }
+                       break;
+               }
+
+               case IPSEC_OPT_INPUT_FRAG_SIZE: {
+                       if (len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       u_int32_t input_frag_size = *(u_int32_t *)data;
+                       if (input_frag_size <= sizeof(struct ip6_hdr)) {
+                               pcb->ipsec_frag_size_set = FALSE;
+                               pcb->ipsec_input_frag_size = 0;
+                       } else {
+                               printf("SET FRAG SIZE TO %u\n", input_frag_size);
+                               pcb->ipsec_frag_size_set = TRUE;
+                               pcb->ipsec_input_frag_size = input_frag_size;
+                       }
+                       break;
+               }
+               case IPSEC_OPT_ENABLE_NETIF: {
+                       if (len != sizeof(int)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       if (pcb->ipsec_ifp != NULL) {
+                               // Only can set before connecting
+                               result = EINVAL;
+                               break;
+                       }
+                       lck_rw_lock_exclusive(&pcb->ipsec_pcb_lock);
+                       pcb->ipsec_use_netif = !!(*(int *)data);
+                       lck_rw_unlock_exclusive(&pcb->ipsec_pcb_lock);
+                       break;
+               }
+               case IPSEC_OPT_SLOT_SIZE: {
+                       if (len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       if (pcb->ipsec_ifp != NULL) {
+                               // Only can set before connecting
+                               result = EINVAL;
+                               break;
+                       }
+                       u_int32_t slot_size = *(u_int32_t *)data;
+                       if (slot_size < IPSEC_IF_MIN_SLOT_SIZE ||
+                               slot_size > IPSEC_IF_MAX_SLOT_SIZE) {
+                               return (EINVAL);
+                       }
+                       pcb->ipsec_slot_size = slot_size;
+                       break;
+               }
+               case IPSEC_OPT_NETIF_RING_SIZE: {
+                       if (len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       if (pcb->ipsec_ifp != NULL) {
+                               // Only can set before connecting
+                               result = EINVAL;
+                               break;
+                       }
+                       u_int32_t ring_size = *(u_int32_t *)data;
+                       if (ring_size < IPSEC_IF_MIN_RING_SIZE ||
+                               ring_size > IPSEC_IF_MAX_RING_SIZE) {
+                               return (EINVAL);
+                       }
+                       pcb->ipsec_netif_ring_size = ring_size;
+                       break;
+               }
+               case IPSEC_OPT_TX_FSW_RING_SIZE: {
+                       if (len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       if (pcb->ipsec_ifp != NULL) {
+                               // Only can set before connecting
+                               result = EINVAL;
+                               break;
+                       }
+                       u_int32_t ring_size = *(u_int32_t *)data;
+                       if (ring_size < IPSEC_IF_MIN_RING_SIZE ||
+                               ring_size > IPSEC_IF_MAX_RING_SIZE) {
+                               return (EINVAL);
+                       }
+                       pcb->ipsec_tx_fsw_ring_size = ring_size;
+                       break;
+               }
+               case IPSEC_OPT_RX_FSW_RING_SIZE: {
+                       if (len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                               break;
+                       }
+                       if (pcb->ipsec_ifp != NULL) {
+                               // Only can set before connecting
+                               result = EINVAL;
+                               break;
+                       }
+                       u_int32_t ring_size = *(u_int32_t *)data;
+                       if (ring_size < IPSEC_IF_MIN_RING_SIZE ||
+                               ring_size > IPSEC_IF_MAX_RING_SIZE) {
+                               return (EINVAL);
+                       }
+                       pcb->ipsec_rx_fsw_ring_size = ring_size;
+                       break;
+               }
+
+#endif // IPSEC_NEXUS
+                       
                default:
                        result = ENOPROTOOPT;
                        break;
@@ -549,38 +2906,151 @@ ipsec_ctl_setopt(__unused kern_ctl_ref  kctlref,
 }
 
 static errno_t
-ipsec_ctl_getopt(__unused kern_ctl_ref kctlref,
-                                __unused u_int32_t             unit,
-                                void                                   *unitinfo,
-                                int                                            opt,
-                                void                                   *data,
-                                size_t                                 *len)
+ipsec_ctl_getopt(__unused kern_ctl_ref kctlref,
+                                __unused u_int32_t unit,
+                                void *unitinfo,
+                                int opt,
+                                void *data,
+                                size_t *len)
 {
-       struct ipsec_pcb                        *pcb = unitinfo;
-       errno_t                                 result = 0;
+       struct ipsec_pcb *pcb = unitinfo;
+       errno_t result = 0;
        
        switch (opt) {
-               case IPSEC_OPT_FLAGS:
-                       if (*len != sizeof(u_int32_t))
+               case IPSEC_OPT_FLAGS: {
+                       if (*len != sizeof(u_int32_t)) {
                                result = EMSGSIZE;
-                       else
+                       } else {
                                *(u_int32_t *)data = pcb->ipsec_flags;
+                       }
                        break;
+               }
                        
-               case IPSEC_OPT_EXT_IFDATA_STATS:
-                       if (*len != sizeof(int))
+               case IPSEC_OPT_EXT_IFDATA_STATS: {
+                       if (*len != sizeof(int)) {
                                result = EMSGSIZE;
-                       else
+                       } else {
                                *(int *)data = (pcb->ipsec_ext_ifdata_stats) ? 1 : 0;
+                       }
                        break;
+               }
                        
-               case IPSEC_OPT_IFNAME:
-                       *len = snprintf(data, *len, "%s%d", ifnet_name(pcb->ipsec_ifp), ifnet_unit(pcb->ipsec_ifp)) + 1;
+               case IPSEC_OPT_IFNAME: {
+                       if (*len < MIN(strlen(pcb->ipsec_if_xname) + 1, sizeof(pcb->ipsec_if_xname))) {
+                               result = EMSGSIZE;
+                       } else {
+                               if (pcb->ipsec_ifp == NULL) {
+                                       // Only can get after connecting
+                                       result = EINVAL;
+                                       break;
+                               }
+                               *len = snprintf(data, *len, "%s", pcb->ipsec_if_xname) + 1;
+                       }
                        break;
+               }
                        
-               default:
+               case IPSEC_OPT_OUTPUT_TRAFFIC_CLASS: {
+                       if (*len != sizeof(int)) {
+                               result = EMSGSIZE;
+                       } else {
+                               *(int *)data = so_svc2tc(pcb->ipsec_output_service_class);
+                       }
+                       break;
+               }
+
+#if IPSEC_NEXUS
+
+               case IPSEC_OPT_ENABLE_CHANNEL: {
+                       if (*len != sizeof(int)) {
+                               result = EMSGSIZE;
+                       } else {
+                               lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+                               *(int *)data = pcb->ipsec_kpipe_enabled;
+                               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+                       }
+                       break;
+               }
+
+               case IPSEC_OPT_ENABLE_FLOWSWITCH: {
+                       if (*len != sizeof(int)) {
+                               result = EMSGSIZE;
+                       } else {
+                               *(int *)data = if_check_netagent(pcb->ipsec_ifp, pcb->ipsec_nx.ms_agent);
+                       }
+                       break;
+               }
+
+               case IPSEC_OPT_ENABLE_NETIF: {
+                       if (*len != sizeof(int)) {
+                               result = EMSGSIZE;
+                       } else {
+                               lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+                               *(int *)data = !!pcb->ipsec_use_netif;
+                               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+                       }
+                       break;
+               }
+
+               case IPSEC_OPT_GET_CHANNEL_UUID: {
+                       lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+                       if (uuid_is_null(pcb->ipsec_kpipe_uuid)) {
+                               result = ENXIO;
+                       } else if (*len != sizeof(uuid_t)) {
+                               result = EMSGSIZE;
+                       } else {
+                               uuid_copy(data, pcb->ipsec_kpipe_uuid);
+                       }
+                       lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+                       break;
+               }
+
+               case IPSEC_OPT_INPUT_FRAG_SIZE: {
+                       if (*len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                       } else {
+                               *(u_int32_t *)data = pcb->ipsec_input_frag_size;
+                       }
+                       break;
+               }
+               case IPSEC_OPT_SLOT_SIZE: {
+                       if (*len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                       } else {
+                               *(u_int32_t *)data = pcb->ipsec_slot_size;
+                       }
+                       break;
+               }
+               case IPSEC_OPT_NETIF_RING_SIZE: {
+                       if (*len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                       } else {
+                               *(u_int32_t *)data = pcb->ipsec_netif_ring_size;
+                       }
+                       break;
+               }
+               case IPSEC_OPT_TX_FSW_RING_SIZE: {
+                       if (*len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                       } else {
+                               *(u_int32_t *)data = pcb->ipsec_tx_fsw_ring_size;
+                       }
+                       break;
+               }
+               case IPSEC_OPT_RX_FSW_RING_SIZE: {
+                       if (*len != sizeof(u_int32_t)) {
+                               result = EMSGSIZE;
+                       } else {
+                               *(u_int32_t *)data = pcb->ipsec_rx_fsw_ring_size;
+                       }
+                       break;
+               }
+
+#endif // IPSEC_NEXUS
+
+               default: {
                        result = ENOPROTOOPT;
                        break;
+               }
        }
        
        return result;
@@ -588,67 +3058,67 @@ ipsec_ctl_getopt(__unused kern_ctl_ref   kctlref,
 
 /* Network Interface functions */
 static errno_t
-ipsec_output(ifnet_t   interface,
-             mbuf_t     data)
+ipsec_output(ifnet_t interface,
+             mbuf_t data)
 {
-       struct ipsec_pcb        *pcb = ifnet_softc(interface);
+       struct ipsec_pcb *pcb = ifnet_softc(interface);
     struct ipsec_output_state ipsec_state;
     struct route ro;
     struct route_in6 ro6;
     int        length;
     struct ip *ip;
     struct ip6_hdr *ip6;
-    struct secpolicy *sp = NULL;
     struct ip_out_args ipoa;
     struct ip6_out_args ip6oa;
     int error = 0;
     u_int ip_version = 0;
-    uint32_t af;
-    int flags = 0;;
-    int out_interface_index = 0;
+    int flags = 0;
     struct flowadv *adv = NULL;
     
-    uint32_t policy_id = 0;
-    
-    /* Find policy using ID in mbuf */
-    policy_id = data->m_pkthdr.ipsec_policy;
-       sp = key_getspbyid(policy_id);
+       // Make sure this packet isn't looping through the interface
+       if (necp_get_last_interface_index_from_packet(data) == interface->if_index) {
+               error = EINVAL;
+               goto ipsec_output_err;
+       }
+       
+       // Mark the interface so NECP can evaluate tunnel policy
+       necp_mark_packet_from_interface(data, interface);
        
-    if (sp == NULL) {
-        printf("ipsec_output: No policy specified, dropping packet.\n");
-        goto ipsec_output_err;
-    }
-    
-    /* Validate policy */
-    if (sp->ipsec_if != pcb->ipsec_ifp) {
-        printf("ipsec_output: Selected policy does not match %s interface.\n", pcb->ipsec_ifp->if_xname);
-        goto ipsec_output_err;
-    }
-    
     ip = mtod(data, struct ip *);
     ip_version = ip->ip_v;
-    
+       
     switch (ip_version) {
-        case 4:
-            /* Tap */
-            af = AF_INET;
-            bpf_tap_out(pcb->ipsec_ifp, DLT_NULL, data, &af, sizeof(af));
-                       
+               case 4: {
+#if IPSEC_NEXUS
+                       if (!pcb->ipsec_use_netif)
+#endif // IPSEC_NEXUS
+                       {
+                               int af = AF_INET;
+                               bpf_tap_out(pcb->ipsec_ifp, DLT_NULL, data, &af, sizeof(af));
+                       }
+
             /* Apply encryption */
-            bzero(&ipsec_state, sizeof(ipsec_state));
+            memset(&ipsec_state, 0, sizeof(ipsec_state));
             ipsec_state.m = data;
-            ipsec_state.dst = (struct sockaddr *)&sp->spidx.dst;
-            bzero(&ipsec_state.ro, sizeof(ipsec_state.ro));
+            ipsec_state.dst = (struct sockaddr *)&ip->ip_dst;
+            memset(&ipsec_state.ro, 0, sizeof(ipsec_state.ro));
                        
-            error = ipsec4_output(&ipsec_state, sp, 0);
+            error = ipsec4_interface_output(&ipsec_state, interface);
+            /* Tunneled in IPv6 - packet is gone */
+            if (error == 0 && ipsec_state.tunneled == 6) {
+                goto done;
+            }
+
             data = ipsec_state.m;
             if (error || data == NULL) {
-                printf("ipsec_output: ipsec4_output error.\n");
+                               if (error) {
+                                       printf("ipsec_output: ipsec4_output error %d.\n", error);
+                               }
                 goto ipsec_output_err;
             }
             
-            /* Set traffic class to OAM, set flow */
-            m_set_service_class(data, MBUF_SC_OAM);
+            /* Set traffic class, set flow */
+            m_set_service_class(data, pcb->ipsec_output_service_class);
             data->m_pkthdr.pkt_flowsrc = FLOWSRC_IFNET;
             data->m_pkthdr.pkt_flowid = interface->if_flowhash;
             data->m_pkthdr.pkt_proto = ip->ip_p;
@@ -664,26 +3134,23 @@ ipsec_output(ifnet_t     interface,
             ifnet_stat_increment_out(interface, 1, length, 0);
                        
             /* Send to ip_output */
-            bzero(&ro, sizeof(ro));
-                       
-            flags = IP_OUTARGS |        /* Passing out args to specify interface */
-                       IP_NOIPSEC;         /* To ensure the packet doesn't go through ipsec twice */
+            memset(&ro, 0, sizeof(ro));
                        
-            if (sp->outgoing_if != NULL) {
-                out_interface_index = sp->outgoing_if->if_index;
-            }
+            flags = (IP_OUTARGS |      /* Passing out args to specify interface */
+                                        IP_NOIPSEC);   /* To ensure the packet doesn't go through ipsec twice */
                        
-            bzero(&ipoa, sizeof(ipoa));
+            memset(&ipoa, 0, sizeof(ipoa));
             ipoa.ipoa_flowadv.code = 0;
             ipoa.ipoa_flags = IPOAF_SELECT_SRCIF | IPOAF_BOUND_SRCADDR;
-            if (out_interface_index) {
-                ipoa.ipoa_boundif = out_interface_index;
+            if (ipsec_state.outgoing_if) {
+                ipoa.ipoa_boundif = ipsec_state.outgoing_if;
                 ipoa.ipoa_flags |= IPOAF_BOUND_IF;
             }
+            ipsec_set_ipoa_for_interface(pcb->ipsec_ifp, &ipoa);
             
             adv = &ipoa.ipoa_flowadv;
             
-            (void) ip_output(data, NULL, &ro, flags, NULL, &ipoa);
+            (void)ip_output(data, NULL, &ro, flags, NULL, &ipoa);
             data = NULL;
             
             if (adv->code == FADV_FLOW_CONTROLLED || adv->code == FADV_SUSPENDED) {
@@ -692,33 +3159,46 @@ ipsec_output(ifnet_t     interface,
             }
             
             goto done;
-        case 6:
-            af = AF_INET6;
-            bpf_tap_out(pcb->ipsec_ifp, DLT_NULL, data, &af, sizeof(af));
-            
+               }
+               case 6: {
+#if IPSEC_NEXUS
+                       if (!pcb->ipsec_use_netif)
+#endif // IPSEC_NEXUS
+                       {
+                               int af = AF_INET6;
+                               bpf_tap_out(pcb->ipsec_ifp, DLT_NULL, data, &af, sizeof(af));
+                       }
+
+            data = ipsec6_splithdr(data);
+                       if (data == NULL) {
+                               printf("ipsec_output: ipsec6_splithdr returned NULL\n");
+                               goto ipsec_output_err;
+                       }
+
             ip6 = mtod(data, struct ip6_hdr *);
+                       
+            memset(&ipsec_state, 0, sizeof(ipsec_state));
+            ipsec_state.m = data;
+            ipsec_state.dst = (struct sockaddr *)&ip6->ip6_dst;
+            memset(&ipsec_state.ro, 0, sizeof(ipsec_state.ro));
             
-            u_char *nexthdrp = &ip6->ip6_nxt;
-            struct mbuf *mprev = data;
-            
-            int needipsectun = 0;
-            error = ipsec6_output_trans(&ipsec_state, nexthdrp, mprev, sp, flags, &needipsectun);
-            if (needipsectun) {
-                error = ipsec6_output_tunnel(&ipsec_state, sp, flags);
-                if (ipsec_state.tunneled == 4) /* tunneled in IPv4 - packet is gone */
-                    goto done;
-            }
+            error = ipsec6_interface_output(&ipsec_state, interface, &ip6->ip6_nxt, ipsec_state.m);
+                       if (error == 0 && ipsec_state.tunneled == 4) {  /* tunneled in IPv4 - packet is gone */
+                               goto done;
+                       }
             data = ipsec_state.m;
             if (error || data == NULL) {
-                printf("ipsec_output: ipsec6_output error.\n");
+                               if (error) {
+                                       printf("ipsec_output: ipsec6_output error %d\n", error);
+                               }
                 goto ipsec_output_err;
             }
             
-            /* Set traffic class to OAM, set flow */
-            m_set_service_class(data, MBUF_SC_OAM);
+            /* Set traffic class, set flow */
+            m_set_service_class(data, pcb->ipsec_output_service_class);
             data->m_pkthdr.pkt_flowsrc = FLOWSRC_IFNET;
             data->m_pkthdr.pkt_flowid = interface->if_flowhash;
-            data->m_pkthdr.pkt_proto = ip->ip_p;
+            data->m_pkthdr.pkt_proto = ip6->ip6_nxt;
             data->m_pkthdr.pkt_flags = (PKTF_FLOW_ID | PKTF_FLOW_ADV | PKTF_FLOW_LOCALSRC);
             
             /* Increment statistics */
@@ -726,21 +3206,18 @@ ipsec_output(ifnet_t     interface,
             ifnet_stat_increment_out(interface, 1, length, 0);
             
             /* Send to ip6_output */
-            bzero(&ro6, sizeof(ro6));
+            memset(&ro6, 0, sizeof(ro6));
             
             flags = IPV6_OUTARGS;
             
-            if (sp->outgoing_if != NULL) {
-                out_interface_index = sp->outgoing_if->if_index;
-            }
-            
-            bzero(&ip6oa, sizeof(ip6oa));
+            memset(&ip6oa, 0, sizeof(ip6oa));
             ip6oa.ip6oa_flowadv.code = 0;
-            ip6oa.ip6oa_flags = IPOAF_SELECT_SRCIF | IPOAF_BOUND_SRCADDR;
-            if (out_interface_index) {
-                ip6oa.ip6oa_boundif = out_interface_index;
-                ip6oa.ip6oa_flags |= IPOAF_BOUND_IF;
+            ip6oa.ip6oa_flags = IP6OAF_SELECT_SRCIF | IP6OAF_BOUND_SRCADDR;
+            if (ipsec_state.outgoing_if) {
+                ip6oa.ip6oa_boundif = ipsec_state.outgoing_if;
+                ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
             }
+            ipsec_set_ip6oa_for_interface(pcb->ipsec_ifp, &ip6oa);
             
             adv = &ip6oa.ip6oa_flowadv;
             
@@ -753,16 +3230,15 @@ ipsec_output(ifnet_t     interface,
             }
             
             goto done;
-        default:
+               }
+               default: {
             printf("ipsec_output: Received unknown packet version %d.\n", ip_version);
-            error = -1;
+            error = EINVAL;
             goto ipsec_output_err;
+               }
     }
        
 done:
-    if (sp != NULL) {
-        key_freesp(sp, KEY_SADB_UNLOCKED);
-    }
     return error;
     
 ipsec_output_err:
@@ -774,13 +3250,16 @@ ipsec_output_err:
 static void
 ipsec_start(ifnet_t    interface)
 {
-    mbuf_t data;
-    
-    for (;;) {
-        if (ifnet_dequeue(interface, &data) != 0)
-            break;
-        (void) ipsec_output(interface, data);
-    }
+       mbuf_t data;
+       struct ipsec_pcb *pcb = ifnet_softc(interface);
+
+       VERIFY(pcb != NULL);
+       for (;;) {
+               if (ifnet_dequeue(interface, &data) != 0)
+                       break;
+               if (ipsec_output(interface, data) != 0)
+                       break;
+       }
 }
 
 /* Network Interface functions */
@@ -843,16 +3322,32 @@ ipsec_del_proto(__unused ifnet_t                         interface,
 }
 
 static errno_t
-ipsec_ioctl(ifnet_t            interface,
-                       u_long          command,
-                       void            *data)
+ipsec_ioctl(ifnet_t interface,
+                       u_long command,
+                       void *data)
 {
+#if IPSEC_NEXUS
+       struct ipsec_pcb *pcb = ifnet_softc(interface);
+#endif
        errno_t result = 0;
        
        switch(command) {
-               case SIOCSIFMTU:
-                       ifnet_set_mtu(interface, ((struct ifreq*)data)->ifr_mtu);
+               case SIOCSIFMTU: {
+#if IPSEC_NEXUS
+                       if (pcb->ipsec_use_netif) {
+                               // Make sure we can fit packets in the channel buffers
+                               if (((uint64_t)((struct ifreq*)data)->ifr_mtu) > pcb->ipsec_slot_size) {
+                                       result = EINVAL;
+                               } else {
+                                       ifnet_set_mtu(interface, (uint32_t)((struct ifreq*)data)->ifr_mtu);
+                               }
+                       } else
+#endif // IPSEC_NEXUS
+                       {
+                               ifnet_set_mtu(interface, ((struct ifreq*)data)->ifr_mtu);
+                       }
                        break;
+               }
                        
                case SIOCSIFFLAGS:
                        /* ifioctl() takes care of it */
@@ -866,27 +3361,46 @@ ipsec_ioctl(ifnet_t              interface,
 }
 
 static void
-ipsec_detached(
-                          ifnet_t      interface)
+ipsec_detached(ifnet_t interface)
 {
-       struct ipsec_pcb        *pcb = ifnet_softc(interface);
-    
-       ifnet_release(pcb->ipsec_ifp);
-       ipsec_free(pcb);
-    
-       OSDecrementAtomic(&ipsec_ifcount);
+       struct ipsec_pcb *pcb = ifnet_softc(interface);
+       (void)ifnet_release(interface);
+       ipsec_free_pcb(pcb, true);
 }
 
 /* Protocol Handlers */
 
 static errno_t
-ipsec_proto_input(__unused ifnet_t     interface,
+ipsec_proto_input(ifnet_t interface,
                                  protocol_family_t     protocol,
-                                 mbuf_t                                m,
-                                 __unused char         *frame_header)
+                                 mbuf_t m,
+                                 __unused char *frame_header)
 {
-       if (proto_input(protocol, m) != 0)
+       mbuf_pkthdr_setrcvif(m, interface);
+
+#if IPSEC_NEXUS
+       struct ipsec_pcb *pcb = ifnet_softc(interface);
+       if (!pcb->ipsec_use_netif)
+#endif // IPSEC_NEXUS
+       {
+               uint32_t af = 0;
+               struct ip *ip = mtod(m, struct ip *);
+               if (ip->ip_v == 4) {
+                       af = AF_INET;
+               } else if (ip->ip_v == 6) {
+                       af = AF_INET6;
+               }
+               bpf_tap_in(interface, DLT_NULL, m, &af, sizeof(af));
+               pktap_input(interface, protocol, m, NULL);
+       }
+
+    int32_t pktlen = m->m_pkthdr.len;
+       if (proto_input(protocol, m) != 0) {
+               ifnet_stat_increment_in(interface, 0, 0, 1);
                m_freem(m);
+       } else {
+               ifnet_stat_increment_in(interface, 1, pktlen, 0);
+       }
        
        return 0;
 }
@@ -924,3 +3438,111 @@ ipsec_attach_proto(ifnet_t                               interface,
        
        return result;
 }
+
+errno_t
+ipsec_inject_inbound_packet(ifnet_t    interface,
+                           mbuf_t      packet)
+{
+#if IPSEC_NEXUS
+       struct ipsec_pcb *pcb = ifnet_softc(interface);
+
+       if (pcb->ipsec_use_netif) {
+               lck_rw_lock_shared(&pcb->ipsec_pcb_lock);
+
+               lck_mtx_lock(&pcb->ipsec_input_chain_lock);
+               if (pcb->ipsec_input_chain != NULL) {
+                       pcb->ipsec_input_chain_last->m_nextpkt = packet;
+               } else {
+                       pcb->ipsec_input_chain = packet;
+               }
+               while (packet->m_nextpkt) {
+                       VERIFY(packet != packet->m_nextpkt);
+                       packet = packet->m_nextpkt;
+               }
+               pcb->ipsec_input_chain_last = packet;
+               lck_mtx_unlock(&pcb->ipsec_input_chain_lock);
+
+               kern_channel_ring_t rx_ring = pcb->ipsec_netif_rxring;
+               lck_rw_unlock_shared(&pcb->ipsec_pcb_lock);
+
+               if (rx_ring != NULL) {
+                       kern_channel_notify(rx_ring, 0);
+               }
+
+               return (0);
+       } else
+#endif // IPSEC_NEXUS
+       {
+               errno_t error;
+               protocol_family_t protocol;
+               if ((error = ipsec_demux(interface, packet, NULL, &protocol)) != 0) {
+                       return error;
+               }
+
+               return ipsec_proto_input(interface, protocol, packet, NULL);
+       }
+}
+
+void
+ipsec_set_pkthdr_for_interface(ifnet_t interface, mbuf_t packet, int family)
+{
+       if (packet != NULL && interface != NULL) {
+               struct ipsec_pcb *pcb = ifnet_softc(interface);
+               if (pcb != NULL) {
+                       /* Set traffic class, set flow */
+                       m_set_service_class(packet, pcb->ipsec_output_service_class);
+                       packet->m_pkthdr.pkt_flowsrc = FLOWSRC_IFNET;
+                       packet->m_pkthdr.pkt_flowid = interface->if_flowhash;
+                       if (family == AF_INET) {
+                               struct ip *ip = mtod(packet, struct ip *);
+                               packet->m_pkthdr.pkt_proto = ip->ip_p;
+                       } else if (family == AF_INET6) {
+                               struct ip6_hdr *ip6 = mtod(packet, struct ip6_hdr *);
+                               packet->m_pkthdr.pkt_proto = ip6->ip6_nxt;
+                       }
+                       packet->m_pkthdr.pkt_flags = (PKTF_FLOW_ID | PKTF_FLOW_ADV | PKTF_FLOW_LOCALSRC);
+               }
+       }
+}
+
+void
+ipsec_set_ipoa_for_interface(ifnet_t interface, struct ip_out_args *ipoa)
+{
+       struct ipsec_pcb *pcb;
+       
+       if (interface == NULL || ipoa == NULL)
+               return;
+       pcb = ifnet_softc(interface);
+       
+       if (net_qos_policy_restricted == 0) {
+               ipoa->ipoa_flags |= IPOAF_QOSMARKING_ALLOWED;
+               ipoa->ipoa_sotc = so_svc2tc(pcb->ipsec_output_service_class);
+       } else if (pcb->ipsec_output_service_class != MBUF_SC_VO ||
+          net_qos_policy_restrict_avapps != 0) {
+               ipoa->ipoa_flags &= ~IPOAF_QOSMARKING_ALLOWED;
+       } else {
+               ipoa->ipoa_flags |= IP6OAF_QOSMARKING_ALLOWED;
+               ipoa->ipoa_sotc = SO_TC_VO;
+       }
+}
+
+void
+ipsec_set_ip6oa_for_interface(ifnet_t interface, struct ip6_out_args *ip6oa)
+{
+       struct ipsec_pcb *pcb;
+       
+       if (interface == NULL || ip6oa == NULL)
+               return;
+       pcb = ifnet_softc(interface);
+       
+       if (net_qos_policy_restricted == 0) {
+               ip6oa->ip6oa_flags |= IPOAF_QOSMARKING_ALLOWED;
+               ip6oa->ip6oa_sotc = so_svc2tc(pcb->ipsec_output_service_class);
+       } else if (pcb->ipsec_output_service_class != MBUF_SC_VO ||
+          net_qos_policy_restrict_avapps != 0) {
+               ip6oa->ip6oa_flags &= ~IPOAF_QOSMARKING_ALLOWED;
+       } else {
+               ip6oa->ip6oa_flags |= IP6OAF_QOSMARKING_ALLOWED;
+               ip6oa->ip6oa_sotc = SO_TC_VO;
+       }
+}