+/*
+ * Copyright (c) 2008 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+
+
+
+/* ----------------------------------------------------------------------------------
+Application of kernel control for interface creation
+
+Theory of operation:
+utun (user tunnel) acts as glue between kernel control sockets and network interfaces.
+This kernel control will register an interface for every client that connects.
+---------------------------------------------------------------------------------- */
+
+#include <sys/systm.h>
+#include <sys/kern_control.h>
+#include <net/kpi_protocol.h>
+#include <net/kpi_interface.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <net/if_types.h>
+#include <net/bpf.h>
+#include <net/if_utun.h>
+#include <libkern/OSMalloc.h>
+#include <libkern/OSAtomic.h>
+#include <sys/mbuf.h>
+#include <sys/sockio.h>
+#include <netinet/in.h>
+#include <netinet6/in6_var.h>
+#include <netinet6/in6_var.h>
+#include <sys/kauth.h>
+
+
+/* Kernel Control functions */
+static errno_t utun_ctl_connect(kern_ctl_ref kctlref, struct sockaddr_ctl *sac,
+ void **unitinfo);
+static errno_t utun_ctl_disconnect(kern_ctl_ref kctlref, u_int32_t unit,
+ void *unitinfo);
+static errno_t utun_ctl_send(kern_ctl_ref kctlref, u_int32_t unit,
+ void *unitinfo, mbuf_t m, int flags);
+static errno_t utun_ctl_getopt(kern_ctl_ref kctlref, u_int32_t unit, void *unitinfo,
+ int opt, void *data, size_t *len);
+static errno_t utun_ctl_setopt(kern_ctl_ref kctlref, u_int32_t unit, void *unitinfo,
+ int opt, void *data, size_t len);
+
+/* Network Interface functions */
+static errno_t utun_output(ifnet_t interface, mbuf_t data);
+static errno_t utun_demux(ifnet_t interface, mbuf_t data, char *frame_header,
+ protocol_family_t *protocol);
+static errno_t utun_framer(ifnet_t interface, mbuf_t *packet,
+ const struct sockaddr *dest, const char *desk_linkaddr,
+ const char *frame_type);
+static errno_t utun_add_proto(ifnet_t interface, protocol_family_t protocol,
+ const struct ifnet_demux_desc *demux_array,
+ u_int32_t demux_count);
+static errno_t utun_del_proto(ifnet_t interface, protocol_family_t protocol);
+static errno_t utun_ioctl(ifnet_t interface, u_long cmd, void *data);
+static void utun_detached(ifnet_t interface);
+
+/* Protocol handlers */
+static errno_t utun_attach_proto(ifnet_t interface, protocol_family_t proto);
+static errno_t utun_proto_input(ifnet_t interface, protocol_family_t protocol,
+ mbuf_t m, char *frame_header);
+static errno_t utun_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);
+
+/* Control block allocated for each kernel control connection */
+struct utun_pcb {
+ kern_ctl_ref ctlref;
+ u_int32_t unit;
+ ifnet_t ifp;
+ u_int32_t flags;
+};
+
+static kern_ctl_ref utun_kctlref;
+static u_int32_t utun_family;
+static OSMallocTag utun_malloc_tag;
+static SInt32 utun_ifcount = 0;
+
+/* Prepend length */
+static void*
+utun_alloc(size_t size)
+{
+ size_t *mem = OSMalloc(size + sizeof(size_t), utun_malloc_tag);
+
+ if (mem) {
+ *mem = size + sizeof(size_t);
+ mem++;
+ }
+
+ return (void*)mem;
+}
+
+static void
+utun_free(void *ptr)
+{
+ size_t *size = ptr;
+ size--;
+ OSFree(size, *size, utun_malloc_tag);
+}
+
+errno_t
+utun_register_control(void)
+{
+ struct kern_ctl_reg kern_ctl;
+ errno_t result = 0;
+
+ /* Create a tag to allocate memory */
+ utun_malloc_tag = OSMalloc_Tagalloc(UTUN_CONTROL_NAME, OSMT_DEFAULT);
+
+ /* Find a unique value for our interface family */
+ result = mbuf_tag_id_find(UTUN_CONTROL_NAME, &utun_family);
+ if (result != 0) {
+ printf("utun_register_control - mbuf_tag_id_find_internal failed: %d\n", result);
+ return result;
+ }
+
+ bzero(&kern_ctl, sizeof(kern_ctl));
+ strncpy(kern_ctl.ctl_name, UTUN_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_connect = utun_ctl_connect;
+ kern_ctl.ctl_disconnect = utun_ctl_disconnect;
+ kern_ctl.ctl_send = utun_ctl_send;
+ kern_ctl.ctl_setopt = utun_ctl_setopt;
+ kern_ctl.ctl_getopt = utun_ctl_getopt;
+
+ result = ctl_register(&kern_ctl, &utun_kctlref);
+ if (result != 0) {
+ printf("utun_register_control - ctl_register failed: %d\n", result);
+ return result;
+ }
+
+ /* Register the protocol plumbers */
+ if ((result = proto_register_plumber(PF_INET, utun_family,
+ utun_attach_proto, NULL)) != 0) {
+ printf("utun_register_control - proto_register_plumber(PF_INET, %d) failed: %d\n",
+ utun_family, result);
+ ctl_deregister(utun_kctlref);
+ return result;
+ }
+
+ /* Register the protocol plumbers */
+ if ((result = proto_register_plumber(PF_INET6, utun_family,
+ utun_attach_proto, NULL)) != 0) {
+ proto_unregister_plumber(PF_INET, utun_family);
+ ctl_deregister(utun_kctlref);
+ printf("utun_register_control - proto_register_plumber(PF_INET6, %d) failed: %d\n",
+ utun_family, result);
+ return result;
+ }
+
+ return 0;
+}
+
+/* Kernel control functions */
+
+static errno_t
+utun_ctl_connect(
+ kern_ctl_ref kctlref,
+ struct sockaddr_ctl *sac,
+ void **unitinfo)
+{
+ struct ifnet_init_params utun_init;
+ struct utun_pcb *pcb;
+ errno_t result;
+
+ /* kernel control allocates, interface frees */
+ pcb = utun_alloc(sizeof(*pcb));
+ if (pcb == NULL)
+ return ENOMEM;
+
+ /* Setup the protocol control block */
+ bzero(pcb, sizeof(*pcb));
+ *unitinfo = pcb;
+ pcb->ctlref = kctlref;
+ pcb->unit = sac->sc_unit;
+
+ printf("utun_ctl_connect: creating interface utun%d\n", pcb->unit - 1);
+
+ /* Create the interface */
+ bzero(&utun_init, sizeof(utun_init));
+ utun_init.name = "utun";
+ utun_init.unit = pcb->unit - 1;
+ utun_init.family = utun_family;
+ utun_init.type = IFT_OTHER;
+ utun_init.output = utun_output;
+ utun_init.demux = utun_demux;
+ utun_init.framer = utun_framer;
+ utun_init.add_proto = utun_add_proto;
+ utun_init.del_proto = utun_del_proto;
+ utun_init.softc = pcb;
+ utun_init.ioctl = utun_ioctl;
+ utun_init.detach = utun_detached;
+
+ result = ifnet_allocate(&utun_init, &pcb->ifp);
+ if (result != 0) {
+ printf("utun_ctl_connect - ifnet_allocate failed: %d\n", result);
+ utun_free(pcb);
+ return result;
+ }
+ OSIncrementAtomic(&utun_ifcount);
+
+ /* Set flags and additional information. */
+ ifnet_set_mtu(pcb->ifp, 1500);
+ ifnet_set_flags(pcb->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->ifp, IFEF_NOAUTOIPV6LL, IFEF_NOAUTOIPV6LL);
+
+ /* Attach the interface */
+ result = ifnet_attach(pcb->ifp, NULL);
+ if (result != 0) {
+ printf("utun_ctl_connect - ifnet_allocate failed: %d\n", result);
+ ifnet_release(pcb->ifp);
+ utun_free(pcb);
+ }
+
+ /* Attach to bpf */
+ if (result == 0)
+ bpfattach(pcb->ifp, DLT_NULL, 4);
+
+ return result;
+}
+
+static errno_t
+utun_detach_ip(
+ ifnet_t interface,
+ protocol_family_t protocol,
+ socket_t pf_socket)
+{
+ errno_t result = EPROTONOSUPPORT;
+
+ /* Attempt a detach */
+ if (protocol == PF_INET) {
+ struct ifreq ifr;
+
+ bzero(&ifr, sizeof(ifr));
+ snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d",
+ ifnet_name(interface), ifnet_unit(interface));
+
+ result = sock_ioctl(pf_socket, SIOCPROTODETACH, &ifr);
+ }
+ else if (protocol == PF_INET6) {
+ struct in6_ifreq ifr6;
+
+ bzero(&ifr6, sizeof(ifr6));
+ snprintf(ifr6.ifr_name, sizeof(ifr6.ifr_name), "%s%d",
+ ifnet_name(interface), ifnet_unit(interface));
+
+ result = sock_ioctl(pf_socket, SIOCPROTODETACH_IN6, &ifr6);
+ }
+
+ return result;
+}
+
+static void
+utun_remove_address(
+ ifnet_t interface,
+ protocol_family_t protocol,
+ ifaddr_t address,
+ socket_t pf_socket)
+{
+ errno_t result = 0;
+
+ /* Attempt a detach */
+ if (protocol == PF_INET) {
+ struct ifreq ifr;
+
+ bzero(&ifr, sizeof(ifr));
+ snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d",
+ ifnet_name(interface), ifnet_unit(interface));
+ result = ifaddr_address(address, &ifr.ifr_addr, sizeof(ifr.ifr_addr));
+ if (result != 0) {
+ printf("utun_remove_address - ifaddr_address failed: %d", result);
+ }
+ else {
+ result = sock_ioctl(pf_socket, SIOCDIFADDR, &ifr);
+ if (result != 0) {
+ printf("utun_remove_address - SIOCDIFADDR failed: %d", result);
+ }
+ }
+ }
+ else if (protocol == PF_INET6) {
+ struct in6_ifreq ifr6;
+
+ bzero(&ifr6, sizeof(ifr6));
+ snprintf(ifr6.ifr_name, sizeof(ifr6.ifr_name), "%s%d",
+ ifnet_name(interface), ifnet_unit(interface));
+ result = ifaddr_address(address, (struct sockaddr*)&ifr6.ifr_addr,
+ sizeof(ifr6.ifr_addr));
+ if (result != 0) {
+ printf("utun_remove_address - ifaddr_address failed (v6): %d",
+ result);
+ }
+ else {
+ result = sock_ioctl(pf_socket, SIOCDIFADDR_IN6, &ifr6);
+ if (result != 0) {
+ printf("utun_remove_address - SIOCDIFADDR_IN6 failed: %d",
+ result);
+ }
+ }
+ }
+}
+
+static void
+utun_cleanup_family(
+ ifnet_t interface,
+ protocol_family_t protocol)
+{
+ errno_t result = 0;
+ socket_t pf_socket = NULL;
+ ifaddr_t *addresses = NULL;
+ int i;
+
+ if (protocol != PF_INET && protocol != PF_INET6) {
+ printf("utun_cleanup_family - invalid protocol family %d\n", protocol);
+ return;
+ }
+
+ /* Create a socket for removing addresses and detaching the protocol */
+ result = sock_socket(protocol, SOCK_DGRAM, 0, NULL, NULL, &pf_socket);
+ if (result != 0) {
+ if (result != EAFNOSUPPORT)
+ printf("utun_cleanup_family - failed to create %s socket: %d\n",
+ protocol == PF_INET ? "IP" : "IPv6", result);
+ goto cleanup;
+ }
+
+ result = utun_detach_ip(interface, protocol, pf_socket);
+ if (result == 0 || result == ENXIO) {
+ /* We are done! We either detached or weren't attached. */
+ goto cleanup;
+ }
+ else if (result != EBUSY) {
+ /* Uh, not really sure what happened here... */
+ printf("utun_cleanup_family - utun_detach_ip failed: %d\n", result);
+ goto cleanup;
+ }
+
+ /*
+ * At this point, we received an EBUSY error. This means there are
+ * addresses attached. We should detach them and then try again.
+ */
+ result = ifnet_get_address_list_family(interface, &addresses, protocol);
+ if (result != 0) {
+ printf("fnet_get_address_list_family(%s%d, 0xblah, %s) - failed: %d\n",
+ ifnet_name(interface), ifnet_unit(interface),
+ protocol == PF_INET ? "PF_INET" : "PF_INET6", result);
+ goto cleanup;
+ }
+
+ for (i = 0; addresses[i] != 0; i++) {
+ utun_remove_address(interface, protocol, addresses[i], pf_socket);
+ }
+ ifnet_free_address_list(addresses);
+ addresses = NULL;
+
+ /*
+ * The addresses should be gone, we should try the remove again.
+ */
+ result = utun_detach_ip(interface, protocol, pf_socket);
+ if (result != 0 && result != ENXIO) {
+ printf("utun_cleanup_family - utun_detach_ip failed: %d\n", result);
+ }
+
+cleanup:
+ if (pf_socket != NULL)
+ sock_close(pf_socket);
+
+ if (addresses != NULL)
+ ifnet_free_address_list(addresses);
+}
+
+static errno_t
+utun_ctl_disconnect(
+ __unused kern_ctl_ref kctlref,
+ __unused u_int32_t unit,
+ void *unitinfo)
+{
+ struct utun_pcb *pcb = unitinfo;
+ ifnet_t ifp = pcb->ifp;
+ errno_t result = 0;
+
+ pcb->ctlref = NULL;
+ pcb->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.
+ */
+ utun_cleanup_family(ifp, AF_INET);
+ utun_cleanup_family(ifp, AF_INET6);
+
+ if ((result = ifnet_detach(ifp)) != 0) {
+ printf("utun_ctl_disconnect - ifnet_detach failed: %d\n", result);
+ }
+
+ if ((result = ifnet_release(ifp)) != 0) {
+ printf("utun_ctl_disconnect - ifnet_release failed: %d\n", result);
+ }
+
+ return 0;
+}
+
+static errno_t
+utun_ctl_send(
+ __unused kern_ctl_ref kctlref,
+ __unused u_int32_t unit,
+ void *unitinfo,
+ mbuf_t m,
+ __unused int flags)
+{
+ struct utun_pcb *pcb = unitinfo;
+ struct ifnet_stat_increment_param incs;
+ errno_t result;
+
+ mbuf_pkthdr_setrcvif(m, pcb->ifp);
+
+ bpf_tap_in(pcb->ifp, DLT_NULL, m, 0, 0);
+
+ if (pcb->flags & UTUN_FLAGS_NO_INPUT) {
+ /* flush data */
+ mbuf_freem(m);
+ return 0;
+ }
+
+ bzero(&incs, sizeof(incs));
+ incs.packets_in = 1;
+ incs.bytes_in = mbuf_pkthdr_len(m);
+ result = ifnet_input(pcb->ifp, m, &incs);
+ if (result != 0) {
+ ifnet_stat_increment_in(pcb->ifp, 0, 0, 1);
+ printf("utun_ctl_send - ifnet_input failed: %d\n", result);
+ mbuf_freem(m);
+ }
+
+ return 0;
+}
+
+static errno_t
+utun_ctl_setopt(
+ __unused kern_ctl_ref kctlref,
+ __unused u_int32_t unit,
+ void *unitinfo,
+ int opt,
+ void *data,
+ size_t len)
+{
+ struct utun_pcb *pcb = unitinfo;
+ errno_t result = 0;
+
+ /* check for privileges for privileged options */
+ switch (opt) {
+ case UTUN_OPT_FLAGS:
+ if (kauth_cred_issuser(kauth_cred_get()) == 0) {
+ return EPERM;
+ }
+ break;
+ }
+
+ switch (opt) {
+ case UTUN_OPT_FLAGS:
+ if (len != sizeof(u_int32_t))
+ result = EMSGSIZE;
+ else
+ pcb->flags = *(u_int32_t *)data;
+ break;
+ default:
+ result = ENOPROTOOPT;
+ break;
+ }
+
+ return result;
+}
+
+static errno_t
+utun_ctl_getopt(
+ __unused kern_ctl_ref kctlref,
+ __unused u_int32_t unit,
+ void *unitinfo,
+ int opt,
+ void *data,
+ size_t *len)
+{
+ struct utun_pcb *pcb = unitinfo;
+ errno_t result = 0;
+
+ switch (opt) {
+ case UTUN_OPT_FLAGS:
+ if (*len != sizeof(u_int32_t))
+ result = EMSGSIZE;
+ else
+ *(u_int32_t *)data = pcb->flags;
+ break;
+ case UTUN_OPT_IFNAME:
+ *len = snprintf(data, *len, "%s%d", ifnet_name(pcb->ifp), ifnet_unit(pcb->ifp)) + 1;
+ break;
+ default:
+ result = ENOPROTOOPT;
+ break;
+ }
+
+ return result;
+}
+
+/* Network Interface functions */
+static errno_t
+utun_output(
+ ifnet_t interface,
+ mbuf_t data)
+{
+ struct utun_pcb *pcb = ifnet_softc(interface);
+ errno_t result;
+
+ bpf_tap_out(pcb->ifp, DLT_NULL, data, 0, 0);
+
+ if (pcb->flags & UTUN_FLAGS_NO_OUTPUT) {
+ /* flush data */
+ mbuf_freem(data);
+ return 0;
+ }
+
+ if (pcb->ctlref) {
+ int length = mbuf_pkthdr_len(data);
+ result = ctl_enqueuembuf(pcb->ctlref, pcb->unit, data, CTL_DATA_EOR);
+ if (result != 0) {
+ mbuf_freem(data);
+ printf("utun_output - ctl_enqueuembuf failed: %d\n", result);
+ ifnet_stat_increment_out(interface, 0, 0, 1);
+ }
+ else {
+ ifnet_stat_increment_out(interface, 1, length, 0);
+ }
+ }
+ else
+ mbuf_freem(data);
+
+ return 0;
+}
+
+/* Network Interface functions */
+static errno_t
+utun_demux(
+ __unused ifnet_t interface,
+ mbuf_t data,
+ __unused char *frame_header,
+ protocol_family_t *protocol)
+{
+
+ while (data != NULL && mbuf_len(data) < 1) {
+ data = mbuf_next(data);
+ }
+
+ if (data == NULL)
+ return ENOENT;
+
+ *protocol = ntohl(*(u_int32_t *)mbuf_data(data));
+ return 0;
+}
+
+static errno_t
+utun_framer(
+ __unused ifnet_t interface,
+ mbuf_t *packet,
+ __unused const struct sockaddr *dest,
+ __unused const char *desk_linkaddr,
+ const char *frame_type)
+{
+
+ if (mbuf_prepend(packet, sizeof(protocol_family_t), MBUF_DONTWAIT) != 0) {
+ printf("utun_framer - ifnet_output prepend failed\n");
+ ifnet_stat_increment_out(interface, 0, 0, 1);
+ // just return, because the buffer was freed in mbuf_prepend
+ return EJUSTRETURN;
+ }
+
+ // place protocol number at the beginning of the mbuf
+ *(protocol_family_t *)mbuf_data(*packet) = htonl(*(protocol_family_t *)(uintptr_t)(size_t)frame_type);
+
+ return 0;
+}
+
+static errno_t
+utun_add_proto(
+ __unused ifnet_t interface,
+ protocol_family_t protocol,
+ __unused const struct ifnet_demux_desc *demux_array,
+ __unused u_int32_t demux_count)
+{
+ switch(protocol) {
+ case PF_INET:
+ return 0;
+ case PF_INET6:
+ return 0;
+ default:
+ break;
+ }
+
+ return ENOPROTOOPT;
+}
+
+static errno_t
+utun_del_proto(
+ __unused ifnet_t interface,
+ __unused protocol_family_t protocol)
+{
+ return 0;
+}
+
+static errno_t
+utun_ioctl(
+ __unused ifnet_t interface,
+ __unused u_long command,
+ void *data)
+{
+ errno_t result = 0;
+ struct ifaddr *ifa = (struct ifaddr *)data;
+
+ switch(command) {
+ case SIOCSIFMTU:
+ ifnet_set_mtu(interface, ((struct ifreq*)data)->ifr_mtu);
+ break;
+
+ case SIOCSIFADDR:
+ case SIOCAIFADDR:
+ /* This will be called for called for IPv6 Address additions */
+ if (ifa->ifa_addr->sa_family == AF_INET6)
+ break;
+ /* Fall though for other families like IPv4 */
+
+ default:
+ result = EOPNOTSUPP;
+ }
+
+ return result;
+}
+
+static void
+utun_detached(
+ ifnet_t interface)
+{
+ struct utun_pcb *pcb = ifnet_softc(interface);
+
+ utun_free(pcb);
+
+ OSDecrementAtomic(&utun_ifcount);
+}
+
+/* Protocol Handlers */
+
+static errno_t
+utun_proto_input(
+ __unused ifnet_t interface,
+ protocol_family_t protocol,
+ mbuf_t m,
+ __unused char *frame_header)
+{
+
+ // remove protocol family first
+ mbuf_adj(m, sizeof(u_int32_t));
+
+ proto_input(protocol, m);
+
+ return 0;
+}
+
+static errno_t
+utun_proto_pre_output(
+ __unused ifnet_t interface,
+ protocol_family_t protocol,
+ __unused mbuf_t *packet,
+ __unused const struct sockaddr *dest,
+ __unused void *route,
+ __unused char *frame_type,
+ __unused char *link_layer_dest)
+{
+
+ *(protocol_family_t *)(void *)frame_type = protocol;
+ return 0;
+}
+
+static errno_t
+utun_attach_proto(
+ ifnet_t interface,
+ protocol_family_t protocol)
+{
+ struct ifnet_attach_proto_param proto;
+ errno_t result;
+
+ bzero(&proto, sizeof(proto));
+ proto.input = utun_proto_input;
+ proto.pre_output = utun_proto_pre_output;
+
+ result = ifnet_attach_protocol(interface, protocol, &proto);
+ if (result != 0 && result != EEXIST) {
+ printf("utun_attach_inet - ifnet_attach_protocol %d failed: %d\n",
+ protocol, result);
+ }
+
+ return result;
+}
+
projects / apple / xnu.git / blobdiff