xnu-1504.15.3.tar.gz

[apple/xnu.git] / bsd / net / dlil.c

/*
 * Copyright (c) 1999-2010 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@
 */
/*
 *      Data Link Inteface Layer
 *      Author: Ted Walker
 */
/*
 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/domain.h>
#include <sys/user.h>
#include <sys/random.h>
#include <net/if_dl.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_var.h>
#include <net/dlil.h>
#include <net/if_arp.h>
#include <sys/kern_event.h>
#include <sys/kdebug.h>

#include <kern/assert.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/sched_prim.h>
#include <kern/locks.h>
#include <net/kpi_protocol.h>

#include <net/if_types.h>
#include <net/kpi_interfacefilter.h>

#include <libkern/OSAtomic.h>

#include <machine/machine_routines.h>

#include <mach/thread_act.h>

#if CONFIG_MACF_NET
#include <security/mac_framework.h>
#endif /* MAC_NET */

#if PF
#include <net/pfvar.h>
#endif /* PF */

#define DBG_LAYER_BEG                   DLILDBG_CODE(DBG_DLIL_STATIC, 0)
#define DBG_LAYER_END                   DLILDBG_CODE(DBG_DLIL_STATIC, 2)
#define DBG_FNC_DLIL_INPUT      DLILDBG_CODE(DBG_DLIL_STATIC, (1 << 8))
#define DBG_FNC_DLIL_OUTPUT     DLILDBG_CODE(DBG_DLIL_STATIC, (2 << 8))
#define DBG_FNC_DLIL_IFOUT      DLILDBG_CODE(DBG_DLIL_STATIC, (3 << 8))


#define MAX_FRAME_TYPE_SIZE 4 /* LONGWORDS */
#define MAX_LINKADDR        4 /* LONGWORDS */
#define M_NKE M_IFADDR

#if 1
#define DLIL_PRINTF     printf
#else
#define DLIL_PRINTF     kprintf
#endif

#define atomic_add_32(a, n)                                             \
        ((void) OSAddAtomic(n, (volatile SInt32 *)a))

#if PKT_PRIORITY
#define _CASSERT(x)     \
        switch (0) { case 0: case (x): ; }

#define IF_DATA_REQUIRE_ALIGNED_32(f)   \
        _CASSERT(!(offsetof(struct if_data_internal, f) % sizeof (u_int32_t)))

#define IFNET_IF_DATA_REQUIRE_ALIGNED_32(f)     \
        _CASSERT(!(offsetof(struct ifnet, if_data.f) % sizeof (u_int32_t)))
#endif /* PKT_PRIORITY */

enum {
        kProtoKPI_v1    = 1,
        kProtoKPI_v2    = 2
};

struct if_proto {
    SLIST_ENTRY(if_proto)        next_hash;
    int                                          refcount;
    int                                          detaching;
    struct ifnet                         *ifp;
    struct domain                        *dl_domain;
    protocol_family_t           protocol_family;
    int                                         proto_kpi;
    union {
                struct {
                        proto_media_input                       input;
                        proto_media_preout                      pre_output;
                        proto_media_event                       event;
                        proto_media_ioctl                       ioctl;
                        proto_media_detached            detached;
                        proto_media_resolve_multi       resolve_multi;
                        proto_media_send_arp            send_arp;
                } v1;
                struct {
                        proto_media_input_v2            input;
                        proto_media_preout                      pre_output;
                        proto_media_event                       event;
                        proto_media_ioctl                       ioctl;
                        proto_media_detached            detached;
                        proto_media_resolve_multi       resolve_multi;
                        proto_media_send_arp            send_arp;
                } v2;
        } kpi;
};

SLIST_HEAD(proto_hash_entry, if_proto);


struct dlil_ifnet {
    /* ifnet and drvr_ext are used by the stack and drivers
    drvr_ext extends the public ifnet and must follow dl_if */
    struct ifnet        dl_if;                  /* public ifnet */
    
    /* dlil private fields */
    TAILQ_ENTRY(dlil_ifnet) dl_if_link; /* dlil_ifnet are link together */
                                                                /* it is not the ifnet list */
    void                *if_uniqueid;   /* unique id identifying the interface */
    size_t              if_uniqueid_len;/* length of the unique id */
    char                if_namestorage[IFNAMSIZ]; /* interface name storage */
};

struct ifnet_filter {
        TAILQ_ENTRY(ifnet_filter)       filt_next;
    ifnet_t                                             filt_ifp;
    int                                                 filt_detaching;
    
        const char                                      *filt_name;
        void                                            *filt_cookie;
    protocol_family_t                   filt_protocol;
    iff_input_func                              filt_input;
    iff_output_func                             filt_output;
    iff_event_func                              filt_event;
    iff_ioctl_func                              filt_ioctl;
    iff_detached_func                   filt_detached;
};

struct proto_input_entry;

static TAILQ_HEAD(, dlil_ifnet) dlil_ifnet_head;
static lck_grp_t *dlil_lock_group;
static lck_grp_t *ifnet_lock_group;
static lck_grp_t *ifnet_head_lock_group;
static lck_attr_t *ifnet_lock_attr;
static lck_rw_t *ifnet_head_mutex;
static lck_mtx_t *dlil_ifnet_mutex;
static lck_mtx_t *dlil_mutex;
static u_int32_t dlil_read_count = 0;
static u_int32_t dlil_detach_waiting = 0;
u_int32_t dlil_filter_count = 0;
extern u_int32_t        ipv4_ll_arp_aware;

#if IFNET_ROUTE_REFCNT
/*
 * Updating this variable should be done by first acquiring the global
 * radix node head (rnh_lock), in tandem with settting/clearing the
 * PR_AGGDRAIN for routedomain.
 */
u_int32_t ifnet_aggressive_drainers;
static u_int32_t net_rtref;
#endif /* IFNET_ROUTE_REFCNT */

static struct dlil_threading_info dlil_lo_thread;
__private_extern__  struct dlil_threading_info *dlil_lo_thread_ptr = &dlil_lo_thread;

static struct mbuf *dlil_lo_input_mbuf_head = NULL;
static struct mbuf *dlil_lo_input_mbuf_tail = NULL;

#if IFNET_INPUT_SANITY_CHK
static int dlil_lo_input_mbuf_count = 0;
int dlil_input_sanity_check = 0;        /* sanity checking of input packet lists received */
#endif
int dlil_multithreaded_input = 1;
static int cur_dlil_input_threads = 0; 

static int dlil_event_internal(struct ifnet *ifp, struct kev_msg *msg);
static int dlil_detach_filter_internal(interface_filter_t filter, int detached);
static void dlil_call_delayed_detach_thread(void);

static void     dlil_read_begin(void);
static __inline__ void  dlil_read_end(void);
static int      dlil_write_begin(void);
static void     dlil_write_end(void);

#if DEBUG
__private_extern__ int dlil_verbose = 1;
#else
__private_extern__ int dlil_verbose = 0;
#endif /* DEBUG */

unsigned int net_affinity = 1;
static kern_return_t dlil_affinity_set(struct thread *, u_int32_t);

extern void bpfdetach(struct ifnet*);
extern void proto_input_run(void); // new run_netisr

void dlil_input_packet_list(struct ifnet  *ifp, struct mbuf *m);
static void dlil_input_thread_func(struct dlil_threading_info *inpthread); 
__private_extern__ int dlil_create_input_thread(
                ifnet_t, struct dlil_threading_info *);
__private_extern__ void dlil_terminate_input_thread(
                struct dlil_threading_info *);

__private_extern__ void link_rtrequest(int, struct rtentry *, struct sockaddr *);

int dlil_expand_mcl;

extern u_int32_t        inject_buckets;

static const u_int32_t dlil_writer_waiting = 0x80000000;
static  lck_grp_attr_t  *dlil_grp_attributes = NULL;
static  lck_attr_t      *dlil_lck_attributes = NULL;
static  lck_grp_t       *dlil_input_lock_grp = NULL;

static inline void*
_cast_non_const(const void * ptr) {
        union {
                const void*             cval;
                void*                   val;
        } ret;
        
        ret.cval = ptr;
        return (ret.val);
}

/* Should these be inline? */
static void
dlil_read_begin(void)
{
        u_int32_t new_value;
        u_int32_t old_value;
        struct uthread *uth = get_bsdthread_info(current_thread());
        
        if (uth->dlil_incremented_read == dlil_writer_waiting)
                panic("dlil_read_begin - thread is already a writer");
        
        do {
again:
                old_value = dlil_read_count;
                
                if ((old_value & dlil_writer_waiting) != 0 && uth->dlil_incremented_read == 0)
                {
                        tsleep(&dlil_read_count, PRIBIO, "dlil_read_count", 1);
                        goto again;
                }
                
                new_value = old_value + 1;
        } while (!OSCompareAndSwap((UInt32)old_value, (UInt32)new_value, (UInt32*)&dlil_read_count));
        
        uth->dlil_incremented_read++;
}

static void
dlil_read_end(void)
{
        struct uthread *uth = get_bsdthread_info(current_thread());
        
        OSDecrementAtomic(&dlil_read_count);
        uth->dlil_incremented_read--;
        if (dlil_read_count == dlil_writer_waiting)
                wakeup(_cast_non_const(&dlil_writer_waiting));
}

static int
dlil_write_begin(void)
{
        struct uthread *uth = get_bsdthread_info(current_thread());
        
        if (uth->dlil_incremented_read != 0) {
                return EDEADLK;
        }
        lck_mtx_lock(dlil_mutex);
        OSBitOrAtomic((UInt32)dlil_writer_waiting, &dlil_read_count);
again:
        if (dlil_read_count == dlil_writer_waiting) {
                uth->dlil_incremented_read = dlil_writer_waiting;
                return 0;
        }
        else {
                tsleep(_cast_non_const(&dlil_writer_waiting), PRIBIO, "dlil_writer_waiting", 1);
                goto again;
        }
}

static void
dlil_write_end(void)
{
        struct uthread *uth = get_bsdthread_info(current_thread());
        
        if (uth->dlil_incremented_read != dlil_writer_waiting)
                panic("dlil_write_end - thread is not a writer");
        OSBitAndAtomic((UInt32)~dlil_writer_waiting, &dlil_read_count);
        lck_mtx_unlock(dlil_mutex);
        uth->dlil_incremented_read = 0;
        wakeup(&dlil_read_count);
}

#define PROTO_HASH_SLOTS        0x5

/*
 * Internal functions.
 */

static int
proto_hash_value(u_int32_t protocol_family)
{
        /*
         * dlil_proto_unplumb_all() depends on the mapping between
         * the hash bucket index and the protocol family defined
         * here; future changes must be applied there as well.
         */
        switch(protocol_family) {
                case PF_INET:
                        return 0;
                case PF_INET6:
                        return 1;
                case PF_APPLETALK:
                        return 2;
                case PF_VLAN:
                        return 3;
                default:
                        return 4;
        }
}

static struct if_proto*
find_attached_proto(struct ifnet *ifp, u_int32_t protocol_family)
{
        struct if_proto *proto = NULL;
        u_int32_t i = proto_hash_value(protocol_family);
        if (ifp->if_proto_hash) {
                proto = SLIST_FIRST(&ifp->if_proto_hash[i]);
        }
        
        while(proto && proto->protocol_family != protocol_family) {
                proto = SLIST_NEXT(proto, next_hash);
        }
        
        return proto;
}

static void
if_proto_ref(struct if_proto *proto)
{
        OSAddAtomic(1, &proto->refcount);
}

static void
if_proto_free(struct if_proto *proto)
{
        int oldval = OSAddAtomic(-1, &proto->refcount);
        
        if (oldval == 1) { /* This was the last reference */
                FREE(proto, M_IFADDR);
        }
}

__private_extern__ void
ifnet_lock_assert(
        __unused struct ifnet *ifp,
        __unused int what)
{
#if IFNET_RW_LOCK
        /*
         * Not implemented for rw locks.
         *
         * Function exists so when/if we use mutex we can
         * enable this check.
         */
#else
        lck_mtx_assert(ifp->if_lock, what);
#endif
}

__private_extern__ void
ifnet_lock_shared(
        struct ifnet *ifp)
{
#if IFNET_RW_LOCK
        lck_rw_lock_shared(ifp->if_lock);
#else
        lck_mtx_assert(ifp->if_lock, LCK_MTX_ASSERT_NOTOWNED);
        lck_mtx_lock(ifp->if_lock);
#endif
}

__private_extern__ void
ifnet_lock_exclusive(
        struct ifnet *ifp)
{
#if IFNET_RW_LOCK
        lck_rw_lock_exclusive(ifp->if_lock);
#else
        lck_mtx_assert(ifp->if_lock, LCK_MTX_ASSERT_NOTOWNED);
        lck_mtx_lock(ifp->if_lock);
#endif
}

__private_extern__ void
ifnet_lock_done(
        struct ifnet *ifp)
{
#if IFNET_RW_LOCK
        lck_rw_done(ifp->if_lock);
#else
        lck_mtx_assert(ifp->if_lock, LCK_MTX_ASSERT_OWNED);
        lck_mtx_unlock(ifp->if_lock);
#endif
}

__private_extern__ void
ifnet_head_lock_shared(void)
{
        lck_rw_lock_shared(ifnet_head_mutex);
}

__private_extern__ void
ifnet_head_lock_exclusive(void)
{
        lck_rw_lock_exclusive(ifnet_head_mutex);
}

__private_extern__ void
ifnet_head_done(void)
{
        lck_rw_done(ifnet_head_mutex);
}

static int dlil_ifp_proto_count(struct ifnet * ifp) 
{
        int                             count = 0;
        int                             i;
        
        if (ifp->if_proto_hash != NULL) {       
                for (i = 0; i < PROTO_HASH_SLOTS; i++) {
                        struct if_proto *proto;
                        SLIST_FOREACH(proto, &ifp->if_proto_hash[i], next_hash) {
                                count++;
                        }
                }
        }
        
        return count;
}

__private_extern__ void
dlil_post_msg(struct ifnet *ifp, u_int32_t event_subclass, u_int32_t event_code, 
                   struct net_event_data *event_data, u_int32_t event_data_len) 
{
        struct net_event_data   ev_data;
        struct kev_msg                  ev_msg;
        
        /* 
         * a net event always starts with a net_event_data structure
         * but the caller can generate a simple net event or
         * provide a longer event structure to post
         */
        
        ev_msg.vendor_code    = KEV_VENDOR_APPLE;
        ev_msg.kev_class      = KEV_NETWORK_CLASS;
        ev_msg.kev_subclass   = event_subclass;
        ev_msg.event_code         = event_code;    
        
        if (event_data == 0) {
                event_data = &ev_data;
                event_data_len = sizeof(struct net_event_data);
        }
        
        strncpy(&event_data->if_name[0], ifp->if_name, IFNAMSIZ);
        event_data->if_family = ifp->if_family;
        event_data->if_unit   = (u_int32_t) ifp->if_unit;
        
        ev_msg.dv[0].data_length = event_data_len;
        ev_msg.dv[0].data_ptr    = event_data;  
        ev_msg.dv[1].data_length = 0;
        
        dlil_event_internal(ifp, &ev_msg);
}

__private_extern__ int
dlil_create_input_thread(
        ifnet_t ifp, struct dlil_threading_info *inputthread)
{
        int error;

        bzero(inputthread, sizeof(*inputthread));
        // loopback ifp may not be configured at dlil_init time.
        if (ifp == lo_ifp)
                strlcat(inputthread->input_name, "dlil_input_main_thread_mtx", 32);
        else
                snprintf(inputthread->input_name, 32, "dlil_input_%s%d_mtx", ifp->if_name, ifp->if_unit);       

        inputthread->lck_grp = lck_grp_alloc_init(inputthread->input_name, dlil_grp_attributes);
        inputthread->input_lck  = lck_mtx_alloc_init(inputthread->lck_grp, dlil_lck_attributes);

        error= kernel_thread_start((thread_continue_t)dlil_input_thread_func, inputthread, &inputthread->input_thread);
        if (error == 0) {
                ml_thread_policy(inputthread->input_thread, MACHINE_GROUP,
                                 (MACHINE_NETWORK_GROUP|MACHINE_NETWORK_NETISR));
                /*
                 * Except for the loopback dlil input thread, we create
                 * an affinity set so that the matching workloop thread
                 * can be scheduled on the same processor set.
                 */
                if (net_affinity && inputthread != dlil_lo_thread_ptr) {
                        struct thread *tp = inputthread->input_thread;
                        u_int32_t tag;
                        /*
                         * Randomize to reduce the probability
                         * of affinity tag namespace collision.
                         */
                        read_random(&tag, sizeof (tag));
                        if (dlil_affinity_set(tp, tag) == KERN_SUCCESS) {
                                thread_reference(tp);
                                inputthread->tag = tag;
                                inputthread->net_affinity = TRUE;
                        }
                }
        } else {
                panic("dlil_create_input_thread: couldn't create thread\n");
        }
        OSAddAtomic(1, &cur_dlil_input_threads);
#if DLIL_DEBUG
        printf("dlil_create_input_thread: threadinfo: %p input_thread=%p threads: cur=%d max=%d\n", 
                inputthread, inputthread->input_thread, dlil_multithreaded_input, cur_dlil_input_threads);
#endif
        return error;
}
__private_extern__ void
dlil_terminate_input_thread(
        struct dlil_threading_info *inputthread)
{
        OSAddAtomic(-1, &cur_dlil_input_threads);

        lck_mtx_unlock(inputthread->input_lck);
        lck_mtx_free(inputthread->input_lck, inputthread->lck_grp);
        lck_grp_free(inputthread->lck_grp);

        FREE(inputthread, M_NKE);

        /* For the extra reference count from kernel_thread_start() */
        thread_deallocate(current_thread());

        thread_terminate(current_thread());
}

static kern_return_t
dlil_affinity_set(struct thread *tp, u_int32_t tag)
{
        thread_affinity_policy_data_t policy;

        bzero(&policy, sizeof (policy));
        policy.affinity_tag = tag;
        return (thread_policy_set(tp, THREAD_AFFINITY_POLICY,
            (thread_policy_t)&policy, THREAD_AFFINITY_POLICY_COUNT));
}

void
dlil_init(void)
{
        thread_t                thread = THREAD_NULL;

        PE_parse_boot_argn("net_affinity", &net_affinity, sizeof (net_affinity));
#if IFNET_ROUTE_REFCNT
        PE_parse_boot_argn("net_rtref", &net_rtref, sizeof (net_rtref));
#endif /* IFNET_ROUTE_REFCNT */

        TAILQ_INIT(&dlil_ifnet_head);
        TAILQ_INIT(&ifnet_head);
        
        /* Setup the lock groups we will use */
        dlil_grp_attributes = lck_grp_attr_alloc_init();

        dlil_lock_group = lck_grp_alloc_init("dlil internal locks", dlil_grp_attributes);
        ifnet_lock_group = lck_grp_alloc_init("ifnet locks", dlil_grp_attributes);
        ifnet_head_lock_group = lck_grp_alloc_init("ifnet head lock", dlil_grp_attributes);
        dlil_input_lock_grp = lck_grp_alloc_init("dlil input lock", dlil_grp_attributes);
        
        /* Setup the lock attributes we will use */
        dlil_lck_attributes = lck_attr_alloc_init();
        
        ifnet_lock_attr = lck_attr_alloc_init();
        
        
        ifnet_head_mutex = lck_rw_alloc_init(ifnet_head_lock_group, dlil_lck_attributes);
        dlil_ifnet_mutex = lck_mtx_alloc_init(dlil_lock_group, dlil_lck_attributes);
        dlil_mutex = lck_mtx_alloc_init(dlil_lock_group, dlil_lck_attributes);
        
        lck_attr_free(dlil_lck_attributes);
        dlil_lck_attributes = NULL;
        
        /*
         * Create and start up the first dlil input thread once everything is initialized
         */
        dlil_create_input_thread(0, dlil_lo_thread_ptr);

        (void) kernel_thread_start((thread_continue_t)dlil_call_delayed_detach_thread, NULL, &thread);
        thread_deallocate(thread);
#if PF
        /* Initialize the packet filter */
        pfinit();
#endif /* PF */
}

__private_extern__ int
dlil_attach_filter(
        struct ifnet                    *ifp,
        const struct iff_filter *if_filter,
        interface_filter_t              *filter_ref)
{
    int retval = 0;
    struct ifnet_filter *filter;
    
        MALLOC(filter, struct ifnet_filter *, sizeof(*filter), M_NKE, M_WAITOK);
        if (filter == NULL)
                return ENOMEM;
        bzero(filter, sizeof(*filter));

    
        filter->filt_ifp = ifp;
        filter->filt_cookie = if_filter->iff_cookie;
        filter->filt_name = if_filter->iff_name;
        filter->filt_protocol = if_filter->iff_protocol;
        filter->filt_input = if_filter->iff_input;
        filter->filt_output = if_filter->iff_output;
        filter->filt_event = if_filter->iff_event;
        filter->filt_ioctl = if_filter->iff_ioctl;
        filter->filt_detached = if_filter->iff_detached;
        
        if ((retval = dlil_write_begin()) != 0) {
                /* Failed to acquire the write lock */
                FREE(filter, M_NKE);
                return retval;
        }
        TAILQ_INSERT_TAIL(&ifp->if_flt_head, filter, filt_next);
        dlil_write_end();
        *filter_ref = filter;

        /*
         * Bump filter count and route_generation ID to let TCP
         * know it shouldn't do TSO on this connection
         */
        OSAddAtomic(1, &dlil_filter_count);
        if (use_routegenid)
                routegenid_update();

        return retval;
}

static int
dlil_detach_filter_internal(
        interface_filter_t      filter,
        int                                     detached)
{
        int retval = 0;
        
        if (detached == 0) {
                ifnet_t                         ifp = NULL;
                interface_filter_t      entry = NULL;

                /* Take the write lock */
                retval = dlil_write_begin();
                if (retval != 0 && retval != EDEADLK)
                        return retval;
                
                /*
                 * At this point either we have the write lock (retval == 0)
                 * or we couldn't get it (retval == EDEADLK) because someone
                 * else up the stack is holding the read lock. It is safe to
                 * read, either the read or write is held. Verify the filter
                 * parameter before proceeding.
                 */
                ifnet_head_lock_shared();
                TAILQ_FOREACH(ifp, &ifnet_head, if_link) {
                        TAILQ_FOREACH(entry, &ifp->if_flt_head, filt_next) {
                                if (entry == filter)
                                        break;
                        }
                        if (entry == filter)
                                break;
                }
                ifnet_head_done();
                
                if (entry != filter) {
                        /* filter parameter is not a valid filter ref */
                        if (retval == 0) {
                                dlil_write_end();
                        }
                        return EINVAL;
                }
                
                if (retval == EDEADLK) {
                        /* Perform a delayed detach */
                        filter->filt_detaching = 1;
                        dlil_detach_waiting = 1;
                        wakeup(&dlil_detach_waiting);
                        return 0;
                }
                
                /* Remove the filter from the list */
                TAILQ_REMOVE(&ifp->if_flt_head, filter, filt_next);
                dlil_write_end();
        }
        
        /* Call the detached funciton if there is one */
        if (filter->filt_detached)
                filter->filt_detached(filter->filt_cookie, filter->filt_ifp);

        /* Free the filter */
        FREE(filter, M_NKE);
        
        /*
         * Decrease filter count and route_generation ID to let TCP
         * know it should reevalute doing TSO or not
         */
        OSAddAtomic(-1, &dlil_filter_count);
        if (use_routegenid)
                routegenid_update();

        return retval;
}

__private_extern__ void
dlil_detach_filter(interface_filter_t filter)
{
        if (filter == NULL)
                return;
        dlil_detach_filter_internal(filter, 0);
}

static void
dlil_input_thread_func(
        struct dlil_threading_info *inputthread)
{
        while (1) {
                struct mbuf *m = NULL, *m_loop = NULL;
#if IFNET_INPUT_SANITY_CHK
                int             loop_cnt = 0, mbuf_cnt;
                int             count;
                struct mbuf *m1;
#endif /* IFNET_INPUT_SANITY_CHK */
                
                lck_mtx_lock(inputthread->input_lck);
                
                /* Wait until there is work to be done */
                while ((inputthread->input_waiting & ~DLIL_INPUT_RUNNING) == 0) {
                        inputthread->input_waiting &= ~DLIL_INPUT_RUNNING;
                        msleep(&inputthread->input_waiting, inputthread->input_lck, 0, inputthread->input_name, 0);
                }

        
                lck_mtx_assert(inputthread->input_lck, LCK_MTX_ASSERT_OWNED);

                m = inputthread->mbuf_head;
                inputthread->mbuf_head = NULL;
                inputthread->mbuf_tail = NULL;

                if (inputthread->input_waiting & DLIL_INPUT_TERMINATE) {
                                if (m)
                                        mbuf_freem_list(m);
                                /* this is the end */
                                dlil_terminate_input_thread(inputthread);
                                return;
                }

                inputthread->input_waiting |= DLIL_INPUT_RUNNING;
                inputthread->input_waiting &= ~DLIL_INPUT_WAITING;

                if (inputthread == dlil_lo_thread_ptr) {
                        m_loop = dlil_lo_input_mbuf_head;
                        dlil_lo_input_mbuf_head = NULL;
                        dlil_lo_input_mbuf_tail = NULL;
                }

#if IFNET_INPUT_SANITY_CHK
                if (dlil_input_sanity_check != 0) {
                        mbuf_cnt = inputthread->mbuf_count;
                        inputthread->mbuf_count = 0;
                        if (inputthread == dlil_lo_thread_ptr) {
                                loop_cnt = dlil_lo_input_mbuf_count;
                                dlil_lo_input_mbuf_count = 0;
                        }
                
                        lck_mtx_unlock(inputthread->input_lck);
                
                        for (m1 = m, count = 0; m1; m1 = mbuf_nextpkt(m1)) {
                                count++;
                        }
                        if (count != mbuf_cnt) {
                                panic("dlil_input_func - thread=%p reg. loop queue has %d packets, should have %d\n",
                                          inputthread, count, mbuf_cnt);
                        }
        
                        if (inputthread == dlil_lo_thread_ptr) {
                                for (m1 = m_loop, count = 0; m1; m1 = mbuf_nextpkt(m1)) {
                                        count++;
                                }
                                if (count != loop_cnt) {
                                        panic("dlil_input_func - thread=%p loop queue has %d packets, should have %d\n",
                                          inputthread, count, loop_cnt);
                                }
                        }
                } else 
#endif /* IFNET_INPUT_SANITY_CHK */
                {
                        lck_mtx_unlock(inputthread->input_lck);
                }


                /*
                * NOTE warning %%% attention !!!!
                * We should think about putting some thread starvation safeguards if 
                * we deal with long chains of packets.
                */
                if (m_loop) {
                        if (inputthread == dlil_lo_thread_ptr)
                                dlil_input_packet_list(lo_ifp, m_loop);
#if IFNET_INPUT_SANITY_CHK
                        else
                                panic("dlil_input_func - thread=%p loop queue has %d packets, should have none!\n",
                                  inputthread, loop_cnt);
#endif /* IFNET_INPUT_SANITY_CHK */
                }


                if (m)
                        dlil_input_packet_list(0, m);


                lck_mtx_lock(inputthread->input_lck);

                if ((inputthread->input_waiting & (DLIL_PROTO_WAITING | DLIL_PROTO_REGISTER)) != 0)  {
                        lck_mtx_unlock(inputthread->input_lck);
                        proto_input_run();
                }       
                else    
                        lck_mtx_unlock(inputthread->input_lck);
        }
}

errno_t
ifnet_input(
        ifnet_t                                                                 ifp,
        mbuf_t                                                                  m_head,
        const struct ifnet_stat_increment_param *stats)
{
        struct thread *tp = current_thread();
        mbuf_t          m_tail;
        struct dlil_threading_info *inp;
#if IFNET_INPUT_SANITY_CHK
        u_int32_t       pkt_count = 0;
#endif /* IFNET_INPUT_SANITY_CHK */

        if (ifp == NULL || m_head == NULL) {
                if (m_head)
                        mbuf_freem_list(m_head);
                return EINVAL;
        }

        m_tail = m_head;
        while (1) {
#if IFNET_INPUT_SANITY_CHK
                if (dlil_input_sanity_check != 0) {
                        ifnet_t rcvif;
                
                        rcvif = mbuf_pkthdr_rcvif(m_tail);
                        pkt_count++;
                
                        if (rcvif == NULL ||
                                (ifp->if_type != IFT_LOOP && rcvif != ifp) ||
                                (mbuf_flags(m_head) & MBUF_PKTHDR) == 0) {
                                panic("ifnet_input - invalid mbuf %p\n", m_tail);
                        }
                }
#endif /* IFNET_INPUT_SANITY_CHK */
                if (mbuf_nextpkt(m_tail) == NULL)
                        break;
                m_tail = mbuf_nextpkt(m_tail);
        }

        inp = ifp->if_input_thread;

        if (dlil_multithreaded_input == 0 || inp == NULL) 
                inp = dlil_lo_thread_ptr;

        /*
         * If there is a matching dlil input thread associated with an
         * affinity set, associate this workloop thread with the same set.
         * We will only do this once.
         */
        lck_mtx_lock(inp->input_lck);
        if (inp->net_affinity && inp->workloop_thread == NULL) {
                u_int32_t tag = inp->tag;
                inp->workloop_thread = tp;
                lck_mtx_unlock(inp->input_lck);

                /* Associated the current thread with the new affinity tag */
                (void) dlil_affinity_set(tp, tag);

                /*
                 * Take a reference on the workloop (current) thread; during
                 * detach, we will need to refer to it in order ot tear down
                 * its affinity.
                 */
                thread_reference(tp);
                lck_mtx_lock(inp->input_lck);
        }

        /* WARNING
         * Because of loopbacked multicast we cannot stuff the ifp in
         * the rcvif of the packet header: loopback has its own dlil
         * input queue
         */

        if (inp == dlil_lo_thread_ptr && ifp->if_type == IFT_LOOP) {
                if (dlil_lo_input_mbuf_head == NULL)
                        dlil_lo_input_mbuf_head = m_head;
                else if (dlil_lo_input_mbuf_tail != NULL)
                        dlil_lo_input_mbuf_tail->m_nextpkt = m_head;
                dlil_lo_input_mbuf_tail = m_tail;
#if IFNET_INPUT_SANITY_CHK
                if (dlil_input_sanity_check != 0) {
                        dlil_lo_input_mbuf_count += pkt_count;
                        inp->input_mbuf_cnt += pkt_count;
                        inp->input_wake_cnt++;

                        lck_mtx_assert(inp->input_lck, LCK_MTX_ASSERT_OWNED);
                }
#endif
        }
        else {
                if (inp->mbuf_head == NULL)
                        inp->mbuf_head = m_head;
                else if (inp->mbuf_tail != NULL)
                        inp->mbuf_tail->m_nextpkt = m_head;
                inp->mbuf_tail = m_tail;
#if IFNET_INPUT_SANITY_CHK
                if (dlil_input_sanity_check != 0) {
                        inp->mbuf_count += pkt_count;
                        inp->input_mbuf_cnt += pkt_count;
                        inp->input_wake_cnt++;

                        lck_mtx_assert(inp->input_lck, LCK_MTX_ASSERT_OWNED);
                }
#endif
        }


        inp->input_waiting |= DLIL_INPUT_WAITING;
        if ((inp->input_waiting & DLIL_INPUT_RUNNING) == 0) {
                wakeup((caddr_t)&inp->input_waiting);
        }
        if (stats) {
                ifp->if_data.ifi_ipackets += stats->packets_in;
                ifp->if_data.ifi_ibytes += stats->bytes_in;
                ifp->if_data.ifi_ierrors += stats->errors_in;
        
                ifp->if_data.ifi_opackets += stats->packets_out;
                ifp->if_data.ifi_obytes += stats->bytes_out;
                ifp->if_data.ifi_oerrors += stats->errors_out;
        
                ifp->if_data.ifi_collisions += stats->collisions;
                ifp->if_data.ifi_iqdrops += stats->dropped;
        }

        lck_mtx_unlock(inp->input_lck);
        
        return 0; 
}

static int
dlil_interface_filters_input(struct ifnet * ifp, struct mbuf * * m_p,
                             char * * frame_header_p,
                             protocol_family_t protocol_family)
{
        struct ifnet_filter *           filter;

        TAILQ_FOREACH(filter, &ifp->if_flt_head, filt_next) {
                int result;

                if (filter->filt_input 
                    && (filter->filt_protocol == 0
                        || filter->filt_protocol == protocol_family)) {
                        result = (*filter->filt_input)(filter->filt_cookie,
                                                       ifp, protocol_family,
                                                       m_p, frame_header_p);
                        if (result != 0) {
                                return (result);
                        }
                }
        }

        /*
         * Strip away M_PROTO1 bit prior to sending packet up the stack as 
         * it is meant to be local to a subsystem -- if_bridge for M_PROTO1
         */
        if (*m_p != NULL)
                (*m_p)->m_flags &= ~M_PROTO1;

        return (0);
}

static void
dlil_ifproto_input(struct if_proto * ifproto, mbuf_t m)
{
        int error;

        if (ifproto->proto_kpi == kProtoKPI_v1) {
                /* Version 1 protocols get one packet at a time */
                while (m != NULL) {
                        char *  frame_header;
                        mbuf_t  next_packet;
                        
                        next_packet = m->m_nextpkt;
                        m->m_nextpkt = NULL;
                        frame_header = m->m_pkthdr.header;
                        m->m_pkthdr.header = NULL;
                        error = (*ifproto->kpi.v1.input)(ifproto->ifp, 
                                                         ifproto->protocol_family,
                                                         m, frame_header);
                        if (error != 0 && error != EJUSTRETURN)
                                m_freem(m);
                        m = next_packet;
                }
        }
        else if (ifproto->proto_kpi == kProtoKPI_v2) {
                /* Version 2 protocols support packet lists */
                error = (*ifproto->kpi.v2.input)(ifproto->ifp,
                                                 ifproto->protocol_family,
                                                 m);
                if (error != 0 && error != EJUSTRETURN)
                        m_freem_list(m);
        }
        return;
}

__private_extern__ void
dlil_input_packet_list(struct ifnet * ifp_param, struct mbuf *m)
{
        int                             error = 0;
        int                             locked = 0;
        protocol_family_t               protocol_family;
        mbuf_t                          next_packet;
        ifnet_t                         ifp = ifp_param;
        char *                          frame_header;
        struct if_proto *               last_ifproto = NULL;
        mbuf_t                          pkt_first = NULL;
        mbuf_t *                        pkt_next = NULL;

        KERNEL_DEBUG(DBG_FNC_DLIL_INPUT | DBG_FUNC_START,0,0,0,0,0);

        while (m != NULL) {
                struct if_proto *       ifproto = NULL;

                next_packet = m->m_nextpkt;
                m->m_nextpkt = NULL;
                if (ifp_param == NULL)
                        ifp = m->m_pkthdr.rcvif;
                frame_header = m->m_pkthdr.header;
                m->m_pkthdr.header = NULL;

                if (locked == 0) {
                        /* dlil lock protects the demux and interface filters */
                        locked = 1;
                        dlil_read_begin();
                }

#if PKT_PRIORITY
                switch (m->m_pkthdr.prio) {
                        case MBUF_TC_BK:
                                ifp->if_tc.ifi_ibkpackets++;
                                ifp->if_tc.ifi_ibkbytes += m->m_pkthdr.len;
                                break;
                        case MBUF_TC_VI:
                                ifp->if_tc.ifi_ivipackets++;
                                ifp->if_tc.ifi_ivibytes += m->m_pkthdr.len;
                                break;
                        case MBUF_TC_VO:
                                ifp->if_tc.ifi_ivopackets++;
                                ifp->if_tc.ifi_ivobytes += m->m_pkthdr.len;
                                break;
                        default:
                                break;
                }
#endif PKT_PRIORITY

                /* find which protocol family this packet is for */
                error = (*ifp->if_demux)(ifp, m, frame_header,
                                         &protocol_family);
                if (error != 0) {
                        if (error == EJUSTRETURN) {
                                goto next;
                        }
                        protocol_family = 0;
                }
                
                /* DANGER!!! */
                if (m->m_flags & (M_BCAST|M_MCAST))
                        ifp->if_imcasts++;

                /* run interface filters, exclude VLAN packets PR-3586856 */
                if ((m->m_pkthdr.csum_flags & CSUM_VLAN_TAG_VALID) == 0) {
                        int     filter_result;

                        filter_result = dlil_interface_filters_input(ifp, &m, 
                                                          &frame_header,
                                                          protocol_family);
                        if (filter_result != 0) {
                                if (filter_result != EJUSTRETURN) {
                                        m_freem(m);
                                }
                                goto next;
                        }
                }
                if (error != 0 || ((m->m_flags & M_PROMISC) != 0) ) {
                        m_freem(m);
                        goto next;
                }
                
                /* Lookup the protocol attachment to this interface */
                if (protocol_family == 0) {
                        ifproto = NULL;
                }
                else if (last_ifproto != NULL
                         && last_ifproto->ifp == ifp
                         && (last_ifproto->protocol_family
                             == protocol_family)) {
                        ifproto = last_ifproto;
                }
                else {
                        ifproto = find_attached_proto(ifp, protocol_family);
                }
                if (ifproto == NULL) {
                        /* no protocol for this packet, discard */
                        m_freem(m);
                        goto next;
                }
                if (ifproto != last_ifproto) {
                        /* make sure ifproto can't go away during input */
                        if_proto_ref(ifproto);
                        if (last_ifproto != NULL) {
                                /* pass up the list for the previous protocol */
                                dlil_read_end();
                                
                                dlil_ifproto_input(last_ifproto, pkt_first);
                                pkt_first = NULL;
                                if_proto_free(last_ifproto);
                                dlil_read_begin();
                        }
                        last_ifproto = ifproto;
                }
                /* extend the list */
                m->m_pkthdr.header = frame_header;
                if (pkt_first == NULL) {
                        pkt_first = m;
                } else {
                        *pkt_next = m;
                }
                pkt_next = &m->m_nextpkt;

        next:
                if (next_packet == NULL && last_ifproto != NULL) {
                        /* pass up the last list of packets */
                        dlil_read_end();

                        dlil_ifproto_input(last_ifproto, pkt_first);
                        if_proto_free(last_ifproto);
                        locked = 0;
                }
                m = next_packet;

        }
        if (locked != 0) {
                dlil_read_end();
        }
        KERNEL_DEBUG(DBG_FNC_DLIL_INPUT | DBG_FUNC_END,0,0,0,0,0);
        return;
}

static int
dlil_event_internal(struct ifnet *ifp, struct kev_msg *event)
{
        struct ifnet_filter *filter;
        
        if (ifp_use(ifp, kIfNetUseCount_MustNotBeZero) == 0) {
                dlil_read_begin();
                
                /* Pass the event to the interface filters */
                TAILQ_FOREACH(filter, &ifp->if_flt_head, filt_next) {
                        if (filter->filt_event)
                                filter->filt_event(filter->filt_cookie, ifp, filter->filt_protocol, event);
                }
                
                if (ifp->if_proto_hash) {
                        int i;

                        for (i = 0; i < PROTO_HASH_SLOTS; i++) {
                                struct if_proto *proto;
                                
                                SLIST_FOREACH(proto, &ifp->if_proto_hash[i], next_hash) {
                                        proto_media_event eventp = proto->proto_kpi == kProtoKPI_v1
                                                 ? proto->kpi.v1.event : proto->kpi.v2.event;
                                        
                                        if (eventp)
                                                eventp(ifp, proto->protocol_family, event);
                                }
                        }
                }
                
                dlil_read_end();
                
                /* Pass the event to the interface */
                if (ifp->if_event)
                        ifp->if_event(ifp, event);
                
                if (ifp_unuse(ifp))
                        ifp_use_reached_zero(ifp);
        }
        
        return kev_post_msg(event);
}

errno_t
ifnet_event(
        ifnet_t                                 ifp,
        struct kern_event_msg   *event)
{
        struct kev_msg               kev_msg;
        int result = 0;

        if (ifp == NULL || event == NULL) return EINVAL;

        kev_msg.vendor_code    = event->vendor_code;
        kev_msg.kev_class      = event->kev_class;
        kev_msg.kev_subclass   = event->kev_subclass;
        kev_msg.event_code     = event->event_code;
        kev_msg.dv[0].data_ptr = &event->event_data[0];
        kev_msg.dv[0].data_length = event->total_size - KEV_MSG_HEADER_SIZE;
        kev_msg.dv[1].data_length = 0;
        
        result = dlil_event_internal(ifp, &kev_msg);

        return result;
}

#if CONFIG_MACF_NET
#include <netinet/ip6.h>
#include <netinet/ip.h>
static int dlil_get_socket_type(struct mbuf **mp, int family, int raw)
{
        struct mbuf *m;
        struct ip *ip;
        struct ip6_hdr *ip6;
        int type = SOCK_RAW;

        if (!raw) {
                switch (family) {
                case PF_INET:
                        m = m_pullup(*mp, sizeof(struct ip));
                        if (m == NULL)
                                break;
                        *mp = m;
                        ip = mtod(m, struct ip *);
                        if (ip->ip_p == IPPROTO_TCP)
                                type = SOCK_STREAM;
                        else if (ip->ip_p == IPPROTO_UDP)
                                type = SOCK_DGRAM;
                        break;
                case PF_INET6:
                        m = m_pullup(*mp, sizeof(struct ip6_hdr));
                        if (m == NULL)
                                break;
                        *mp = m;
                        ip6 = mtod(m, struct ip6_hdr *);
                        if (ip6->ip6_nxt == IPPROTO_TCP)
                                type = SOCK_STREAM;
                        else if (ip6->ip6_nxt == IPPROTO_UDP)
                                type = SOCK_DGRAM;
                        break;
                }
        }

        return (type);
}
#endif

static void
if_inc_traffic_class_out(ifnet_t ifp, mbuf_t m)
{
#if !PKT_PRIORITY
#pragma unused(ifp)
#pragma unused(m)
        return;
#else
        if (!(m->m_flags & M_PKTHDR))
                return;

        switch (m->m_pkthdr.prio) {
                case MBUF_TC_BK:
                        ifp->if_tc.ifi_obkpackets++;
                        ifp->if_tc.ifi_obkbytes += m->m_pkthdr.len;
                        break;
                case MBUF_TC_VI:
                        ifp->if_tc.ifi_ovipackets++;
                        ifp->if_tc.ifi_ovibytes += m->m_pkthdr.len;
                        break;
                case MBUF_TC_VO:
                        ifp->if_tc.ifi_ovopackets++;
                        ifp->if_tc.ifi_ovobytes += m->m_pkthdr.len;
                        break;
                default:
                        break;
        }
#endif PKT_PRIORITY
}

#if 0
int
dlil_output_list(
        struct ifnet* ifp,
        u_long proto_family,
        struct mbuf             *packetlist,
        caddr_t         route,
        const struct sockaddr   *dest,
        int                                             raw)
{
        char                    *frame_type = NULL;
        char                    *dst_linkaddr = NULL;
        int                             retval = 0;
        char                    frame_type_buffer[MAX_FRAME_TYPE_SIZE * 4];
        char                    dst_linkaddr_buffer[MAX_LINKADDR * 4];
        struct ifnet_filter *filter;
        struct if_proto *proto = 0;
        mbuf_t  m;
        mbuf_t  send_head = NULL;
        mbuf_t  *send_tail = &send_head;
        
        KERNEL_DEBUG(DBG_FNC_DLIL_OUTPUT | DBG_FUNC_START,0,0,0,0,0);
        
        dlil_read_begin();
        
        frame_type         = frame_type_buffer;
        dst_linkaddr   = dst_linkaddr_buffer;
        
        if (raw == 0) {
                proto = find_attached_proto(ifp, proto_family);
                if (proto == NULL) {
                        retval = ENXIO;
                        goto cleanup;
                }
        }
        
preout_again:
        if (packetlist == NULL)
                goto cleanup;
        m = packetlist;
        packetlist = packetlist->m_nextpkt;
        m->m_nextpkt = NULL;
        
        if (raw == 0) {
                proto_media_preout preoutp = proto->proto_kpi == kProtoKPI_v1
                         ? proto->kpi.v1.pre_output : proto->kpi.v2.pre_output;
                retval = 0;
                if (preoutp)
                        retval = preoutp(ifp, proto_family, &m, dest, route, frame_type, dst_linkaddr);
        
                if (retval) {
                        if (retval == EJUSTRETURN) {
                                goto preout_again;
                        }
                        
                        m_freem(m);
                        goto cleanup;
                }
        }

        do {
#if CONFIG_MACF_NET
                retval = mac_ifnet_check_transmit(ifp, m, proto_family,
                    dlil_get_socket_type(&m, proto_family, raw));
                if (retval) {
                        m_freem(m);
                        goto cleanup;
                }
#endif
        
                if (raw == 0 && ifp->if_framer) {
                        retval = ifp->if_framer(ifp, &m, dest, dst_linkaddr, frame_type); 
                        if (retval) {
                                if (retval != EJUSTRETURN) {
                                        m_freem(m);
                                }
                                goto next;
                        }
                }
        
                /* 
                 * Let interface filters (if any) do their thing ...
                 */
                /* Do not pass VLAN tagged packets to filters PR-3586856 */
                if ((m->m_pkthdr.csum_flags & CSUM_VLAN_TAG_VALID) == 0) {
                        TAILQ_FOREACH(filter, &ifp->if_flt_head, filt_next) {
                                if ((filter->filt_protocol == 0 || (filter->filt_protocol == proto_family)) &&
                                        filter->filt_output) {
                                        retval = filter->filt_output(filter->filt_cookie, ifp, proto_family, &m);
                                        if (retval) {
                                                if (retval != EJUSTRETURN)
                                                        m_freem(m);
                                                goto next;
                                        }
                                }
                        }
                }
                /*
                 * Strip away M_PROTO1 bit prior to sending packet to the driver 
                 * as this field may be used by the driver
                 */
                m->m_flags &= ~M_PROTO1;
                
                /*
                 * Finally, call the driver.
                 */
        
                if ((ifp->if_eflags & IFEF_SENDLIST) != 0) {
                        *send_tail = m;
                        send_tail = &m->m_nextpkt;
                }
                else {
                        KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_START, 0,0,0,0,0);
                        retval = ifp->if_output(ifp, m);
                        if (retval && dlil_verbose) {
                                printf("dlil_output: output error on %s%d retval = %d\n", 
                                        ifp->if_name, ifp->if_unit, retval);
                        }
                        KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_END, 0,0,0,0,0);
                }
                KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_END, 0,0,0,0,0);

next:
                m = packetlist;
                if (m) {
                        packetlist = packetlist->m_nextpkt;
                        m->m_nextpkt = NULL;
                }
        } while (m);

        if (send_head) {
                KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_START, 0,0,0,0,0);
                retval = ifp->if_output(ifp, send_head);
                if (retval && dlil_verbose) {
                        printf("dlil_output: output error on %s%d retval = %d\n",
                                ifp->if_name, ifp->if_unit, retval);
                }
                KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_END, 0,0,0,0,0);
        }
        
        KERNEL_DEBUG(DBG_FNC_DLIL_OUTPUT | DBG_FUNC_END,0,0,0,0,0);

cleanup:
        dlil_read_end();
        if (packetlist) /* if any packet left, clean up */
                mbuf_freem_list(packetlist);
        if (retval == EJUSTRETURN)
                retval = 0;
        return retval;
}
#endif

/*
 * dlil_output
 *
 * Caller should have a lock on the protocol domain if the protocol
 * doesn't support finer grained locking. In most cases, the lock
 * will be held from the socket layer and won't be released until
 * we return back to the socket layer.
 *
 * This does mean that we must take a protocol lock before we take
 * an interface lock if we're going to take both. This makes sense
 * because a protocol is likely to interact with an ifp while it
 * is under the protocol lock.
 */
__private_extern__ errno_t
dlil_output(
        ifnet_t                                 ifp,
        protocol_family_t               proto_family,
        mbuf_t                                  packetlist,
        void                                    *route,
        const struct sockaddr   *dest,
        int                                             raw)
{
        char                    *frame_type = NULL;
        char                    *dst_linkaddr = NULL;
        int                             retval = 0;
        char                    frame_type_buffer[MAX_FRAME_TYPE_SIZE * 4];
        char                    dst_linkaddr_buffer[MAX_LINKADDR * 4];
        struct ifnet_filter *filter;
        struct if_proto *proto = 0;
        mbuf_t  m;
        mbuf_t  send_head = NULL;
        mbuf_t  *send_tail = &send_head;
        
        KERNEL_DEBUG(DBG_FNC_DLIL_OUTPUT | DBG_FUNC_START,0,0,0,0,0);
        
        dlil_read_begin();
        
        frame_type         = frame_type_buffer;
        dst_linkaddr   = dst_linkaddr_buffer;
        
        if (raw == 0) {
                proto = find_attached_proto(ifp, proto_family);
                if (proto == NULL) {
                        retval = ENXIO;
                        goto cleanup;
                }
        }
        
preout_again:
        if (packetlist == NULL)
                goto cleanup;
        m = packetlist;
        packetlist = packetlist->m_nextpkt;
        m->m_nextpkt = NULL;
        
        if (raw == 0) {
                proto_media_preout preoutp = proto->proto_kpi == kProtoKPI_v1
                         ? proto->kpi.v1.pre_output : proto->kpi.v2.pre_output;
                retval = 0;
                if (preoutp)
                        retval = preoutp(ifp, proto_family, &m, dest, route, frame_type, dst_linkaddr);
        
                if (retval) {
                        if (retval == EJUSTRETURN) {
                                goto preout_again;
                        }
                        
                        m_freem(m);
                        goto cleanup;
                }
        }

#if CONFIG_MACF_NET
        retval = mac_ifnet_check_transmit(ifp, m, proto_family,
            dlil_get_socket_type(&m, proto_family, raw));
        if (retval) {
                m_freem(m);
                goto cleanup;
        }
#endif

        do {
                if (raw == 0 && ifp->if_framer) {
                        int rcvif_set = 0;

                        /*
                         * If this is a broadcast packet that needs to be
                         * looped back into the system, set the inbound ifp
                         * to that of the outbound ifp.  This will allow
                         * us to determine that it is a legitimate packet
                         * for the system.  Only set the ifp if it's not
                         * already set, just to be safe.
                         */
                        if ((m->m_flags & (M_BCAST | M_LOOP)) &&
                            m->m_pkthdr.rcvif == NULL) {
                                m->m_pkthdr.rcvif = ifp;
                                rcvif_set = 1;
                        }

                        retval = ifp->if_framer(ifp, &m, dest, dst_linkaddr, frame_type); 
                        if (retval) {
                                if (retval != EJUSTRETURN) {
                                        m_freem(m);
                                }
                                goto next;
                        }

                        /*
                         * Clear the ifp if it was set above, and to be
                         * safe, only if it is still the same as the
                         * outbound ifp we have in context.  If it was
                         * looped back, then a copy of it was sent to the
                         * loopback interface with the rcvif set, and we
                         * are clearing the one that will go down to the
                         * layer below.
                         */
                        if (rcvif_set && m->m_pkthdr.rcvif == ifp)
                                m->m_pkthdr.rcvif = NULL;
                }
        
                /* 
                 * Let interface filters (if any) do their thing ...
                 */
                /* Do not pass VLAN tagged packets to filters PR-3586856 */
                if ((m->m_pkthdr.csum_flags & CSUM_VLAN_TAG_VALID) == 0) {
                        TAILQ_FOREACH(filter, &ifp->if_flt_head, filt_next) {
                                if ((filter->filt_protocol == 0 || (filter->filt_protocol == proto_family)) &&
                                        filter->filt_output) {
                                        retval = filter->filt_output(filter->filt_cookie, ifp, proto_family, &m);
                                        if (retval) {
                                                if (retval != EJUSTRETURN)
                                                        m_freem(m);
                                                goto next;
                                        }
                                }
                        }
                }

                /*
                 * Strip away M_PROTO1 bit prior to sending packet to the driver
                 * as this field may be used by the driver
                 */
                m->m_flags &= ~M_PROTO1;

                /*
                 * If the underlying interface is not capable of handling a
                 * packet whose data portion spans across physically disjoint
                 * pages, we need to "normalize" the packet so that we pass
                 * down a chain of mbufs where each mbuf points to a span that
                 * resides in the system page boundary.  If the packet does
                 * not cross page(s), the following is a no-op.
                 */
                if (!(ifp->if_hwassist & IFNET_MULTIPAGES)) {
                        if ((m = m_normalize(m)) == NULL)
                                goto next;
                }

                /* 
                 * If this is a TSO packet, make sure the interface still advertise TSO capability
                 */

                if ((m->m_pkthdr.csum_flags & CSUM_TSO_IPV4) && !(ifp->if_hwassist & IFNET_TSO_IPV4)) {
                                retval = EMSGSIZE;
                                m_freem(m);
                                goto cleanup;
                }

                if ((m->m_pkthdr.csum_flags & CSUM_TSO_IPV6) && !(ifp->if_hwassist & IFNET_TSO_IPV6)) {
                                retval = EMSGSIZE;
                                m_freem(m);
                                goto cleanup;
                }
                /*
                 * Finally, call the driver.
                 */
        
                if ((ifp->if_eflags & IFEF_SENDLIST) != 0) {
                        *send_tail = m;
                        send_tail = &m->m_nextpkt;
                }
                else {
                        KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_START, 0,0,0,0,0);
                        
                        if_inc_traffic_class_out(ifp, m);

                        retval = ifp->if_output(ifp, m);
                        if (retval && dlil_verbose) {
                                printf("dlil_output: output error on %s%d retval = %d\n", 
                                        ifp->if_name, ifp->if_unit, retval);
                        }
                        KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_END, 0,0,0,0,0);
                }
                KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_END, 0,0,0,0,0);

next:
                m = packetlist;
                if (m) {
                        packetlist = packetlist->m_nextpkt;
                        m->m_nextpkt = NULL;
                }
        } while (m);

        if (send_head) {
                KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_START, 0,0,0,0,0);
                
                if_inc_traffic_class_out(ifp, send_head);

                retval = ifp->if_output(ifp, send_head);
                if (retval && dlil_verbose) {
                        printf("dlil_output: output error on %s%d retval = %d\n", 
                                ifp->if_name, ifp->if_unit, retval);
                }
                KERNEL_DEBUG(DBG_FNC_DLIL_IFOUT | DBG_FUNC_END, 0,0,0,0,0);
        }
        
        KERNEL_DEBUG(DBG_FNC_DLIL_OUTPUT | DBG_FUNC_END,0,0,0,0,0);

cleanup:
        dlil_read_end();
        if (packetlist) /* if any packet left, clean up */
                mbuf_freem_list(packetlist);
        if (retval == EJUSTRETURN)
                retval = 0;
        return retval;
}

errno_t
ifnet_ioctl(
        ifnet_t                         ifp,
        protocol_family_t       proto_fam,
        u_long                  ioctl_code,
        void                            *ioctl_arg)
{
        struct ifnet_filter             *filter;
        int                                             retval = EOPNOTSUPP;
        int                                             result = 0;
        int                                             holding_read = 0;
        
        if (ifp == NULL || ioctl_code == 0)
                return EINVAL;
        
        /* Attempt to increment the use count. If it's zero, bail out, the ifp is invalid */
        result = ifp_use(ifp, kIfNetUseCount_MustNotBeZero);
        if (result != 0)
                return EOPNOTSUPP;
        
        dlil_read_begin();
        holding_read = 1;
        
        /* Run the interface filters first.
         * We want to run all filters before calling the protocol,
         * interface family, or interface.
         */
        TAILQ_FOREACH(filter, &ifp->if_flt_head, filt_next) {
                if ((filter->filt_protocol == 0 || (filter->filt_protocol == proto_fam)) &&
                        filter->filt_ioctl != NULL) {
                        result = filter->filt_ioctl(filter->filt_cookie, ifp, proto_fam, ioctl_code, ioctl_arg);
                        /* Only update retval if no one has handled the ioctl */
                        if (retval == EOPNOTSUPP || result == EJUSTRETURN) {
                                if (result == ENOTSUP)
                                        result = EOPNOTSUPP;
                                retval = result;
                                if (retval && retval != EOPNOTSUPP) {
                                        goto cleanup;
                                }
                        }
                }
        }
        
        /* Allow the protocol to handle the ioctl */
        if (proto_fam) {
                struct if_proto *proto = find_attached_proto(ifp, proto_fam);
                
                if (proto != 0) {
                        proto_media_ioctl ioctlp = proto->proto_kpi == kProtoKPI_v1
                                 ? proto->kpi.v1.ioctl : proto->kpi.v2.ioctl;
                        result = EOPNOTSUPP;
                        if (ioctlp)
                                result = ioctlp(ifp, proto_fam, ioctl_code, ioctl_arg);
                        
                        /* Only update retval if no one has handled the ioctl */
                        if (retval == EOPNOTSUPP || result == EJUSTRETURN) {
                                if (result == ENOTSUP)
                                        result = EOPNOTSUPP;
                                retval = result;
                                if (retval && retval != EOPNOTSUPP) {
                                        goto cleanup;
                                }
                        }
                }
        }
        
        /*
         * Since we have incremented the use count on the ifp, we are guaranteed
         * that the ifp will not go away (the function pointers may not be changed).
         * We release the dlil read lock so the interface ioctl may trigger a
         * protocol attach. This happens with vlan and may occur with other virtual
         * interfaces.
         */
        dlil_read_end();
        holding_read = 0;
        
        /* retval is either 0 or EOPNOTSUPP */
        
        /*
         * Let the interface handle this ioctl.
         * If it returns EOPNOTSUPP, ignore that, we may have
         * already handled this in the protocol or family.
         */
        if (ifp->if_ioctl) 
                result = (*ifp->if_ioctl)(ifp, ioctl_code, ioctl_arg);
        
        /* Only update retval if no one has handled the ioctl */
        if (retval == EOPNOTSUPP || result == EJUSTRETURN) {
                if (result == ENOTSUP)
                        result = EOPNOTSUPP;
                retval = result;
                if (retval && retval != EOPNOTSUPP) {
                        goto cleanup;
                }
        }
        
cleanup:
        if (holding_read)
                dlil_read_end();
        if (ifp_unuse(ifp))
                ifp_use_reached_zero(ifp);

        if (retval == EJUSTRETURN)
                retval = 0;
        return retval;
}

__private_extern__ errno_t
dlil_set_bpf_tap(
        ifnet_t                 ifp,
        bpf_tap_mode    mode,
        bpf_packet_func callback)
{
        errno_t error = 0;
        
        dlil_read_begin();
        if (ifp->if_set_bpf_tap)
                error = ifp->if_set_bpf_tap(ifp, mode, callback);
        dlil_read_end();
        
        return error;
}

errno_t
dlil_resolve_multi(
        struct ifnet *ifp,
        const struct sockaddr *proto_addr,
        struct sockaddr *ll_addr,
        size_t ll_len)
{
        errno_t result = EOPNOTSUPP;
        struct if_proto *proto;
        const struct sockaddr *verify;
        proto_media_resolve_multi resolvep;
        
        dlil_read_begin();
        
        bzero(ll_addr, ll_len);
        
        /* Call the protocol first */
        proto = find_attached_proto(ifp, proto_addr->sa_family);
        if (proto != NULL) {
                resolvep = proto->proto_kpi == kProtoKPI_v1
                         ? proto->kpi.v1.resolve_multi : proto->kpi.v2.resolve_multi;
                if (resolvep != NULL)
                        result = resolvep(ifp, proto_addr,(struct sockaddr_dl*)ll_addr,
                                                          ll_len);
        }
        
        /* Let the interface verify the multicast address */
        if ((result == EOPNOTSUPP || result == 0) && ifp->if_check_multi) {
                if (result == 0)
                        verify = ll_addr;
                else
                        verify = proto_addr;
                result = ifp->if_check_multi(ifp, verify);
        }
        
        dlil_read_end();
        
        return result;
}

__private_extern__ errno_t
dlil_send_arp_internal(
        ifnet_t ifp,
        u_short arpop,
        const struct sockaddr_dl* sender_hw,
        const struct sockaddr* sender_proto,
        const struct sockaddr_dl* target_hw,
        const struct sockaddr* target_proto)
{
        struct if_proto *proto;
        errno_t result = 0;
        
        dlil_read_begin();
        
        proto = find_attached_proto(ifp, target_proto->sa_family);
        if (proto == NULL) {
                result = ENOTSUP;
        }
        else {
                proto_media_send_arp    arpp;
                arpp = proto->proto_kpi == kProtoKPI_v1
                         ? proto->kpi.v1.send_arp : proto->kpi.v2.send_arp;
                if (arpp == NULL)
                        result = ENOTSUP;
                else
                        result = arpp(ifp, arpop, sender_hw, sender_proto, target_hw,
                                                  target_proto);
        }
        
        dlil_read_end();
        
        return result;
}

static __inline__ int
_is_announcement(const struct sockaddr_in * sender_sin,
                     const struct sockaddr_in * target_sin)
{
        if (sender_sin == NULL) {
                return FALSE;
        }
        return (sender_sin->sin_addr.s_addr == target_sin->sin_addr.s_addr);
}

__private_extern__ errno_t
dlil_send_arp(
        ifnet_t ifp,
        u_short arpop,
        const struct sockaddr_dl* sender_hw,
        const struct sockaddr* sender_proto,
        const struct sockaddr_dl* target_hw,
        const struct sockaddr* target_proto)
{
        errno_t result = 0;
        const struct sockaddr_in * sender_sin;
        const struct sockaddr_in * target_sin;
        
        if (target_proto == NULL || (sender_proto &&
                sender_proto->sa_family != target_proto->sa_family))
                return EINVAL;
        
        /*
         * If this is an ARP request and the target IP is IPv4LL,
         * send the request on all interfaces.  The exception is
         * an announcement, which must only appear on the specific
         * interface.
         */
        sender_sin = (const struct sockaddr_in *)sender_proto;
        target_sin = (const struct sockaddr_in *)target_proto;
        if (target_proto->sa_family == AF_INET
            && IN_LINKLOCAL(ntohl(target_sin->sin_addr.s_addr))
            && ipv4_ll_arp_aware != 0
            && arpop == ARPOP_REQUEST
            && !_is_announcement(target_sin, sender_sin)) {
                ifnet_t         *ifp_list;
                u_int32_t       count;
                u_int32_t       ifp_on;
                
                result = ENOTSUP;

                if (ifnet_list_get(IFNET_FAMILY_ANY, &ifp_list, &count) == 0) {
                        for (ifp_on = 0; ifp_on < count; ifp_on++) {
                                errno_t                         new_result;
                                ifaddr_t                        source_hw = NULL;
                                ifaddr_t                        source_ip = NULL;
                                struct sockaddr_in      source_ip_copy;
                                
                                /*
                                 * Only arp on interfaces marked for IPv4LL ARPing. This may
                                 * mean that we don't ARP on the interface the subnet route
                                 * points to.
                                 */
                                if ((ifp_list[ifp_on]->if_eflags & IFEF_ARPLL) == 0) {
                                        continue;
                                }

                                /* Find the source IP address */
                                ifnet_lock_shared(ifp_list[ifp_on]);
                                source_hw = TAILQ_FIRST(&ifp_list[ifp_on]->if_addrhead);
                                TAILQ_FOREACH(source_ip, &ifp_list[ifp_on]->if_addrhead,
                                                          ifa_link) {
                                        if (source_ip->ifa_addr &&
                                                source_ip->ifa_addr->sa_family == AF_INET) {
                                                break;
                                        }
                                }
                                
                                /* No IP Source, don't arp */
                                if (source_ip == NULL) {
                                        ifnet_lock_done(ifp_list[ifp_on]);
                                        continue;
                                }
                                
                                /* Copy the source IP address */
                                source_ip_copy = *(struct sockaddr_in*)source_ip->ifa_addr;
                                ifaref(source_hw);
                                ifnet_lock_done(ifp_list[ifp_on]);
                                
                                /* Send the ARP */
                                new_result = dlil_send_arp_internal(ifp_list[ifp_on], arpop,
                                                                        (struct sockaddr_dl*)source_hw->ifa_addr,
                                                                        (struct sockaddr*)&source_ip_copy, NULL,
                                                                        target_proto);

                                ifafree(source_hw);
                                if (result == ENOTSUP) {
                                        result = new_result;
                                }
                        }
                }
                
                ifnet_list_free(ifp_list);
        }
        else {
                result = dlil_send_arp_internal(ifp, arpop, sender_hw, sender_proto,
                                                                                target_hw, target_proto);
        }
        
        return result;
}

__private_extern__ int
ifp_use(
        struct ifnet *ifp,
        int     handle_zero)
{
        int old_value;
        int retval = 0;
        
        do {
                old_value = ifp->if_usecnt;
                if (old_value == 0 && handle_zero == kIfNetUseCount_MustNotBeZero) {
                        retval = ENXIO; // ifp is invalid
                        break;
                }
        } while (!OSCompareAndSwap((UInt32)old_value, (UInt32)old_value + 1, (UInt32*)&ifp->if_usecnt));
 
        return retval;
}

/* ifp_unuse is broken into two pieces.
 *
 * ifp_use and ifp_unuse must be called between when the caller calls
 * dlil_write_begin and dlil_write_end. ifp_unuse needs to perform some
 * operations after dlil_write_end has been called. For this reason,
 * anyone calling ifp_unuse must call ifp_use_reached_zero if ifp_unuse
 * returns a non-zero value. The caller must call ifp_use_reached_zero
 * after the caller has called dlil_write_end.
 */
__private_extern__ void
ifp_use_reached_zero(
        struct ifnet *ifp)
{
        ifnet_detached_func     free_func;
        
        dlil_read_begin();
        
        if (ifp->if_usecnt != 0)
                panic("ifp_use_reached_zero: ifp->if_usecnt != 0");
        
        ifnet_head_lock_exclusive();
        ifnet_lock_exclusive(ifp);
        
        /* Remove ourselves from the list */
        TAILQ_REMOVE(&ifnet_head, ifp, if_link);
        ifnet_addrs[ifp->if_index - 1] = NULL;
        
        /* ifp should be removed from the interface list */
        while (ifp->if_multiaddrs.lh_first) {
                struct ifmultiaddr *ifma = ifp->if_multiaddrs.lh_first;
                
                /*
                 * When the interface is gone, we will no longer
                 * be listening on these multicasts. Various bits
                 * of the stack may be referencing these multicasts,
                 * release only our reference.
                 */
                LIST_REMOVE(ifma, ifma_link);
                ifma->ifma_ifp = NULL;
                ifma_release(ifma);
        }

        ifp->if_eflags &= ~IFEF_DETACHING; // clear the detaching flag
        ifnet_lock_done(ifp);
        ifnet_head_done();

        free_func = ifp->if_free;
        dlil_read_end();
        dlil_post_msg(ifp, KEV_DL_SUBCLASS, KEV_DL_IF_DETACHED, NULL, 0);
        
        if (free_func)
                free_func(ifp);
}

__private_extern__ int
ifp_unuse(
        struct ifnet *ifp)
{
        int     oldval;
        oldval = OSDecrementAtomic(&ifp->if_usecnt);
        if (oldval == 0)
                panic("ifp_unuse: ifp(%s%d)->if_usecnt was zero\n", ifp->if_name, ifp->if_unit);
        
        if (oldval > 1)
                return 0;
        
        if ((ifp->if_eflags & IFEF_DETACHING) == 0)
                panic("ifp_unuse: use count reached zero but detching flag is not set!");
        
        return 1; /* caller must call ifp_use_reached_zero */
}

extern lck_mtx_t        *domain_proto_mtx;

static errno_t
dlil_attach_protocol_internal(
        struct if_proto *proto,
        const struct ifnet_demux_desc *demux_list,
        u_int32_t       demux_count)
{
        struct kev_dl_proto_data        ev_pr_data;
        struct ifnet *ifp = proto->ifp;
        int retval = 0;
        u_int32_t hash_value = proto_hash_value(proto->protocol_family);
    
    /* setup some of the common values */
        {
                struct domain *dp;
                lck_mtx_lock(domain_proto_mtx);
                dp = domains;
                while (dp && (protocol_family_t)dp->dom_family != proto->protocol_family)
                        dp = dp->dom_next;
                proto->dl_domain = dp;
                lck_mtx_unlock(domain_proto_mtx);
        }
        
        /*
         * Take the write lock to protect readers and exclude other writers.
         */
        if ((retval = dlil_write_begin()) != 0) {
                printf("dlil_attach_protocol_internal - dlil_write_begin returned %d\n", retval);
                return retval;
        }
        
        /* Check that the interface isn't currently detaching */
        ifnet_lock_shared(ifp);
        if ((ifp->if_eflags & IFEF_DETACHING) != 0) {
                ifnet_lock_done(ifp);
                dlil_write_end();
                return ENXIO;
        }
        ifnet_lock_done(ifp);
        
        if (find_attached_proto(ifp, proto->protocol_family) != NULL) {
                dlil_write_end();
                return EEXIST;
        }
        
        /*
         * Call family module add_proto routine so it can refine the
         * demux descriptors as it wishes.
         */
        retval = ifp->if_add_proto(ifp, proto->protocol_family, demux_list, demux_count);
        if (retval) {
                dlil_write_end();
                return retval;
        }
        
        /*
         * We can't fail from this point on.
         * Increment the number of uses (protocol attachments + interface attached).
         */
        ifp_use(ifp, kIfNetUseCount_MustNotBeZero);
        
        /*
         * Insert the protocol in the hash
         */
        {
                struct if_proto*        prev_proto = SLIST_FIRST(&ifp->if_proto_hash[hash_value]);
                while (prev_proto && SLIST_NEXT(prev_proto, next_hash) != NULL)
                        prev_proto = SLIST_NEXT(prev_proto, next_hash);
                if (prev_proto)
                        SLIST_INSERT_AFTER(prev_proto, proto, next_hash);
                else
                        SLIST_INSERT_HEAD(&ifp->if_proto_hash[hash_value], proto, next_hash);
        }

        /*
         * Add to if_proto list for this interface
         */
        if_proto_ref(proto);
        dlil_write_end();
        
        /* the reserved field carries the number of protocol still attached (subject to change) */
        ev_pr_data.proto_family = proto->protocol_family;
        ev_pr_data.proto_remaining_count = dlil_ifp_proto_count(ifp);
        dlil_post_msg(ifp, KEV_DL_SUBCLASS, KEV_DL_PROTO_ATTACHED, 
                                  (struct net_event_data *)&ev_pr_data, 
                                  sizeof(struct kev_dl_proto_data));
#if 0   
        DLIL_PRINTF("dlil. Attached protocol %d to %s%d - %d\n", proto->protocol_family,
                         ifp->if_name, ifp->if_unit, retval);
#endif
        return retval;
}

errno_t
ifnet_attach_protocol(ifnet_t ifp, protocol_family_t protocol,
        const struct ifnet_attach_proto_param *proto_details)
{
        int retval = 0;
        struct if_proto  *ifproto = NULL;
        
        if (ifp == NULL || protocol == 0 || proto_details == NULL)
                return EINVAL;
        
        ifproto = _MALLOC(sizeof(struct if_proto), M_IFADDR, M_WAITOK);
        if (ifproto == 0) {
                DLIL_PRINTF("ERROR - dlil failed if_proto allocation\n");
                retval = ENOMEM;
                goto end;
        }
        bzero(ifproto, sizeof(*ifproto));
        
        ifproto->ifp = ifp;
        ifproto->protocol_family = protocol;
        ifproto->proto_kpi = kProtoKPI_v1;
        ifproto->kpi.v1.input = proto_details->input;
        ifproto->kpi.v1.pre_output = proto_details->pre_output;
        ifproto->kpi.v1.event = proto_details->event;
        ifproto->kpi.v1.ioctl = proto_details->ioctl;
        ifproto->kpi.v1.detached = proto_details->detached;
        ifproto->kpi.v1.resolve_multi = proto_details->resolve;
        ifproto->kpi.v1.send_arp = proto_details->send_arp;
        
        retval = dlil_attach_protocol_internal(ifproto,
                                proto_details->demux_list, proto_details->demux_count);
        
end:
        if (retval && ifproto)
                FREE(ifproto, M_IFADDR);
        return retval;
}

errno_t
ifnet_attach_protocol_v2(ifnet_t ifp, protocol_family_t protocol,
        const struct ifnet_attach_proto_param_v2 *proto_details)
{
        int retval = 0;
        struct if_proto  *ifproto = NULL;
        
        if (ifp == NULL || protocol == 0 || proto_details == NULL)
                return EINVAL;
        
        ifproto = _MALLOC(sizeof(struct if_proto), M_IFADDR, M_WAITOK);
        if (ifproto == 0) {
                DLIL_PRINTF("ERROR - dlil failed if_proto allocation\n");
                retval = ENOMEM;
                goto end;
        }
        bzero(ifproto, sizeof(*ifproto));
        
        ifproto->ifp = ifp;
        ifproto->protocol_family = protocol;
        ifproto->proto_kpi = kProtoKPI_v2;
        ifproto->kpi.v2.input = proto_details->input;
        ifproto->kpi.v2.pre_output = proto_details->pre_output;
        ifproto->kpi.v2.event = proto_details->event;
        ifproto->kpi.v2.ioctl = proto_details->ioctl;
        ifproto->kpi.v2.detached = proto_details->detached;
        ifproto->kpi.v2.resolve_multi = proto_details->resolve;
        ifproto->kpi.v2.send_arp = proto_details->send_arp;
        
        retval = dlil_attach_protocol_internal(ifproto,
                                proto_details->demux_list, proto_details->demux_count);
        
end:
        if (retval && ifproto)
                FREE(ifproto, M_IFADDR);
        return retval;
}

extern void if_rtproto_del(struct ifnet *ifp, int protocol);

static int
dlil_detach_protocol_internal(
        struct if_proto *proto)
{
        struct ifnet *ifp = proto->ifp;
        u_int32_t proto_family = proto->protocol_family;
        struct kev_dl_proto_data        ev_pr_data;
        
        if (proto->proto_kpi == kProtoKPI_v1) {
                if (proto->kpi.v1.detached)
                        proto->kpi.v1.detached(ifp, proto->protocol_family);
        }
        if (proto->proto_kpi == kProtoKPI_v2) {
                if (proto->kpi.v2.detached)
                        proto->kpi.v2.detached(ifp, proto->protocol_family);
        }
        if_proto_free(proto);
    
        /*
         * Cleanup routes that may still be in the routing table for that interface/protocol pair.
         */
        
        if_rtproto_del(ifp, proto_family);
        
        /* the reserved field carries the number of protocol still attached (subject to change) */
        ev_pr_data.proto_family   = proto_family;
        ev_pr_data.proto_remaining_count = dlil_ifp_proto_count(ifp);
        dlil_post_msg(ifp, KEV_DL_SUBCLASS, KEV_DL_PROTO_DETACHED, 
                                  (struct net_event_data *)&ev_pr_data, 
                                  sizeof(struct kev_dl_proto_data));
        return 0;
}

errno_t
ifnet_detach_protocol(ifnet_t ifp, protocol_family_t proto_family)
{
        struct if_proto *proto = NULL;
        int     retval = 0;
        int use_reached_zero = 0;
        
        if (ifp == NULL || proto_family == 0) return EINVAL;

        if ((retval = dlil_write_begin()) != 0) {
                if (retval == EDEADLK) {
                        retval = 0;
                        dlil_read_begin();
                        proto = find_attached_proto(ifp, proto_family);
                        if (proto == 0) {
                                retval = ENXIO;
                        }
                        else {
                                proto->detaching = 1;
                                dlil_detach_waiting = 1;
                                wakeup(&dlil_detach_waiting);
                        }
                        dlil_read_end();
                }
                goto end;
        }
        
        proto = find_attached_proto(ifp, proto_family);
        
        if (proto == NULL) {
                retval = ENXIO;
                dlil_write_end();
                goto end;
        }
        
        /*
         * Call family module del_proto
         */
        
        if (ifp->if_del_proto)
                ifp->if_del_proto(ifp, proto->protocol_family);

        SLIST_REMOVE(&ifp->if_proto_hash[proto_hash_value(proto_family)], proto, if_proto, next_hash);
        
        /*
         * We can do the rest of the work outside of the write lock.
         */
        use_reached_zero = ifp_unuse(ifp);
        dlil_write_end();
        
        dlil_detach_protocol_internal(proto);

        /*
         * Only handle the case where the interface will go away after
         * we've sent the message. This way post message can send the
         * message to the interface safely.
         */
        
        if (use_reached_zero)
                ifp_use_reached_zero(ifp);
        
end:
    return retval;
}

/*
 * dlil_delayed_detach_thread is responsible for detaching
 * protocols, protocol filters, and interface filters after
 * an attempt was made to detach one of those items while
 * it was not safe to do so (i.e. called dlil_read_begin).
 *
 * This function will take the dlil write lock and walk
 * through each of the interfaces looking for items with
 * the detaching flag set. When an item is found, it is
 * detached from the interface and placed on a local list.
 * After all of the items have been collected, we drop the
 * write lock and performed the post detach. This is done
 * so we only have to take the write lock once.
 *
 * When detaching a protocol filter, if we find that we
 * have detached the very last protocol and we need to call
 * ifp_use_reached_zero, we have to break out of our work
 * to drop the write lock so we can call ifp_use_reached_zero.
 */
 
static void
dlil_delayed_detach_thread(__unused void* foo, __unused wait_result_t wait)
{
        thread_t self = current_thread();
        int asserted = 0;
        
        ml_thread_policy(self, MACHINE_GROUP,
                                         (MACHINE_NETWORK_GROUP|MACHINE_NETWORK_NETISR));

        
        while (1) {
                if (dlil_detach_waiting != 0 && dlil_write_begin() == 0) {
                        struct ifnet *ifp;
                        struct proto_hash_entry detached_protos;
                        struct ifnet_filter_head detached_filters;
                        struct if_proto *proto;
                        struct if_proto *next_proto;
                        struct ifnet_filter *filt;
                        struct ifnet_filter *next_filt;
                        int reached_zero;
                        
                        reached_zero = 0;
                        
                        /* Clear the detach waiting flag */
                        dlil_detach_waiting = 0;
                        TAILQ_INIT(&detached_filters);
                        SLIST_INIT(&detached_protos);
                        
                        ifnet_head_lock_shared();
                        TAILQ_FOREACH(ifp, &ifnet_head, if_link) {
                                int i;
                                
                                // Look for protocols and protocol filters
                                for (i = 0; i < PROTO_HASH_SLOTS && !reached_zero; i++) {
                                        struct if_proto **prev_nextptr = &SLIST_FIRST(&ifp->if_proto_hash[i]);
                                        for (proto = *prev_nextptr; proto; proto = *prev_nextptr) {
                                                
                                                // Detach this protocol
                                                if (proto->detaching) {
                                                        if (ifp->if_del_proto)
                                                                ifp->if_del_proto(ifp, proto->protocol_family);
                                                        *prev_nextptr = SLIST_NEXT(proto, next_hash);
                                                        SLIST_INSERT_HEAD(&detached_protos, proto, next_hash);
                                                        reached_zero = ifp_unuse(ifp);
                                                        if (reached_zero) {
                                                                break;
                                                        }
                                                }
                                                else {
                                                        // Update prev_nextptr to point to our next ptr
                                                        prev_nextptr = &SLIST_NEXT(proto, next_hash);
                                                }
                                        }
                                }
                                
                                // look for interface filters that need to be detached
                                for (filt = TAILQ_FIRST(&ifp->if_flt_head); filt; filt = next_filt) {
                                        next_filt = TAILQ_NEXT(filt, filt_next);
                                        if (filt->filt_detaching != 0) {
                                                // take this interface filter off the interface filter list
                                                TAILQ_REMOVE(&ifp->if_flt_head, filt, filt_next);
                                                
                                                // put this interface filter on the detached filters list
                                                TAILQ_INSERT_TAIL(&detached_filters, filt, filt_next);
                                        }
                                }
                                
                                if (ifp->if_delayed_detach) {
                                        ifp->if_delayed_detach = 0;
                                        reached_zero = ifp_unuse(ifp);
                                }
                                
                                if (reached_zero)
                                        break;
                        }
                        ifnet_head_done();
                        dlil_write_end();
                        
                        for (filt = TAILQ_FIRST(&detached_filters); filt; filt = next_filt) {
                                next_filt = TAILQ_NEXT(filt, filt_next);
                                /*
                                 * dlil_detach_filter_internal won't remove an item from
                                 * the list if it is already detached (second parameter).
                                 * The item will be freed though.
                                 */
                                dlil_detach_filter_internal(filt, 1);
                        }
                        
                        for (proto = SLIST_FIRST(&detached_protos); proto; proto = next_proto) {
                                next_proto = SLIST_NEXT(proto, next_hash);
                                dlil_detach_protocol_internal(proto);
                        }
                        
                        if (reached_zero) {
                                ifp_use_reached_zero(ifp);
                                dlil_detach_waiting = 1; // we may have missed something
                        }
                }
                
                if (!asserted && dlil_detach_waiting == 0) {
                        asserted = 1;
                        assert_wait(&dlil_detach_waiting, THREAD_UNINT);
                }
                
                if (dlil_detach_waiting == 0) {
                        asserted = 0;
                        thread_block(dlil_delayed_detach_thread);
                }
        }
}

static void
dlil_call_delayed_detach_thread(void) {
        dlil_delayed_detach_thread(NULL, THREAD_RESTART);
}

extern int if_next_index(void);

errno_t
ifnet_attach(
        ifnet_t                                         ifp,
        const struct sockaddr_dl        *ll_addr)
{
        u_int32_t                   interface_family;
        struct ifnet *tmp_if;
        struct proto_hash_entry *new_proto_list = NULL;
        int locked = 0;
        
        if (ifp == NULL) return EINVAL;
        if (ll_addr && ifp->if_addrlen == 0) {
                ifp->if_addrlen = ll_addr->sdl_alen;
        }
        else if (ll_addr && ll_addr->sdl_alen != ifp->if_addrlen) {
                return EINVAL;
        }
        
        interface_family = ifp->if_family;
        
        ifnet_head_lock_shared();

        /* Verify we aren't already on the list */
        TAILQ_FOREACH(tmp_if, &ifnet_head, if_link) {
                if (tmp_if == ifp) {
                        ifnet_head_done();
                        return EEXIST;
                }
        }
        
        ifnet_head_done();
        
        if ((ifp->if_eflags & IFEF_REUSE) == 0 || ifp->if_lock == 0)
#if IFNET_RW_LOCK
                ifp->if_lock = lck_rw_alloc_init(ifnet_lock_group, ifnet_lock_attr);
#else
                ifp->if_lock = lck_mtx_alloc_init(ifnet_lock_group, ifnet_lock_attr);
#endif

        if (ifp->if_lock == 0) {
                return ENOMEM;
        }

        if (!(ifp->if_eflags & IFEF_REUSE) || ifp->if_fwd_route_lock == NULL) {
                if (ifp->if_fwd_route_lock == NULL)
                        ifp->if_fwd_route_lock = lck_mtx_alloc_init(
                            ifnet_lock_group, ifnet_lock_attr);

                if (ifp->if_fwd_route_lock == NULL) {
#if IFNET_RW_LOCK
                        lck_rw_free(ifp->if_lock, ifnet_lock_group);
#else
                        lck_mtx_free(ifp->if_lock, ifnet_lock_group);
#endif
                        ifp->if_lock = NULL;
                        return (ENOMEM);
                }
        }

        /*
         * Allow interfaces without protocol families to attach
         * only if they have the necessary fields filled out.
         */
        
        if (ifp->if_add_proto == 0 || ifp->if_del_proto == 0) {
                DLIL_PRINTF("dlil Attempt to attach interface without family module - %d\n", 
                                interface_family);
                return ENODEV;
        }
        
        if ((ifp->if_eflags & IFEF_REUSE) == 0 || ifp->if_proto_hash == NULL) {
                MALLOC(new_proto_list, struct proto_hash_entry*, sizeof(struct proto_hash_entry) * PROTO_HASH_SLOTS,
                           M_NKE, M_WAITOK);

                if (new_proto_list == 0) {
                        return ENOBUFS;
                }
        }

        dlil_write_begin();
        locked = 1;

        TAILQ_INIT(&ifp->if_flt_head);
        
                
        if (new_proto_list) {
                bzero(new_proto_list, (PROTO_HASH_SLOTS * sizeof(struct proto_hash_entry)));
                ifp->if_proto_hash = new_proto_list;
                new_proto_list = NULL;
        }
        
        /* old_if_attach */
        {
                char workbuf[64];
                int namelen, masklen, socksize, ifasize;
                struct ifaddr *ifa = NULL;
                
                if (ifp->if_snd.ifq_maxlen == 0)
                        ifp->if_snd.ifq_maxlen = ifqmaxlen;
                TAILQ_INIT(&ifp->if_prefixhead);
                LIST_INIT(&ifp->if_multiaddrs);
                ifnet_touch_lastchange(ifp);
                
                /* usecount to track attachment to the ifnet list */
                ifp_use(ifp, kIfNetUseCount_MayBeZero);
                
                /* Lock the list of interfaces */
                ifnet_head_lock_exclusive();
                ifnet_lock_exclusive(ifp);
                
                if ((ifp->if_eflags & IFEF_REUSE) == 0 || ifp->if_index == 0) {
                        int idx = if_next_index();
            
            if (idx == -1) {
                ifnet_lock_done(ifp);
                ifnet_head_done();
                ifp_unuse(ifp);
                dlil_write_end();
                
                return ENOBUFS;
            }
                        ifp->if_index = idx;
                } else {
                        ifa = TAILQ_FIRST(&ifp->if_addrhead);
                }
                namelen = snprintf(workbuf, sizeof(workbuf), "%s%d", ifp->if_name, ifp->if_unit);
#define _offsetof(t, m) ((uintptr_t)((caddr_t)&((t *)0)->m))
                masklen = _offsetof(struct sockaddr_dl, sdl_data[0]) + namelen;
                socksize = masklen + ifp->if_addrlen;
#define ROUNDUP(a) (1 + (((a) - 1) | (sizeof(u_int32_t) - 1)))
                if ((u_int32_t)socksize < sizeof(struct sockaddr_dl))
                        socksize = sizeof(struct sockaddr_dl);
                socksize = ROUNDUP(socksize);
                ifasize = sizeof(struct ifaddr) + 2 * socksize;
                
                /*
                 * Allocate a new ifa if we don't have one
                 * or the old one is too small.
                 */
                if (ifa == NULL || socksize > ifa->ifa_addr->sa_len) {
                        if (ifa)
                                if_detach_ifa(ifp, ifa);
                        ifa = (struct ifaddr*)_MALLOC(ifasize, M_IFADDR, M_WAITOK);
                }
                
                if (ifa) {
                        struct sockaddr_dl *sdl = (struct sockaddr_dl *)(ifa + 1);
                        ifnet_addrs[ifp->if_index - 1] = ifa;
                        bzero(ifa, ifasize);
                        ifa->ifa_debug |= IFD_ALLOC;
                        sdl->sdl_len = socksize;
                        sdl->sdl_family = AF_LINK;
                        bcopy(workbuf, sdl->sdl_data, namelen);
                        sdl->sdl_nlen = namelen;
                        sdl->sdl_index = ifp->if_index;
                        sdl->sdl_type = ifp->if_type;
                        if (ll_addr) {
                                sdl->sdl_alen = ll_addr->sdl_alen;
                                if (ll_addr->sdl_alen != ifp->if_addrlen)
                                        panic("ifnet_attach - ll_addr->sdl_alen != ifp->if_addrlen");
                                bcopy(CONST_LLADDR(ll_addr), LLADDR(sdl), sdl->sdl_alen);
                        }
                        ifa->ifa_ifp = ifp;
                        ifa->ifa_rtrequest = link_rtrequest;
                        ifa->ifa_addr = (struct sockaddr*)sdl;
                        sdl = (struct sockaddr_dl*)(socksize + (caddr_t)sdl);
                        ifa->ifa_netmask = (struct sockaddr*)sdl;
                        sdl->sdl_len = masklen;
                        while (namelen != 0)
                                sdl->sdl_data[--namelen] = 0xff;
                }

                TAILQ_INIT(&ifp->if_addrhead);
                ifa = ifnet_addrs[ifp->if_index - 1];
                
                if (ifa) {
                        /*
                         * We don't use if_attach_ifa because we want
                         * this address to be first on the list.
                         */
                        ifaref(ifa);
                        ifa->ifa_debug |= IFD_ATTACHED;
                        TAILQ_INSERT_HEAD(&ifp->if_addrhead, ifa, ifa_link);
                }
#if CONFIG_MACF_NET
                mac_ifnet_label_associate(ifp);
#endif
                
                TAILQ_INSERT_TAIL(&ifnet_head, ifp, if_link);
                ifindex2ifnet[ifp->if_index] = ifp;
        }

        /* 
         * A specific dlil input thread is created per Ethernet/PDP interface.
         * pseudo interfaces or other types of interfaces use the main ("loopback") thread.
         * If the sysctl "net.link.generic.system.multi_threaded_input" is set to zero, all packets will
         * be handled by the main loopback thread, reverting to 10.4.x behaviour.
         * 
         */

        if (ifp->if_type == IFT_ETHER || ifp->if_type == IFT_PDP) {
                int err;

                if (dlil_multithreaded_input > 0) {
                        ifp->if_input_thread = _MALLOC(sizeof(struct dlil_threading_info), M_NKE, M_WAITOK);
                        if (ifp->if_input_thread == NULL)
                                panic("ifnet_attach ifp=%p couldn't alloc threading\n", ifp);
                        if ((err = dlil_create_input_thread(ifp, ifp->if_input_thread)) != 0)
                                panic("ifnet_attach ifp=%p couldn't get a thread. err=%d\n", ifp, err);
#ifdef DLIL_DEBUG
                        printf("ifnet_attach: dlil thread for ifp=%p if_index=%d\n", ifp, ifp->if_index);
#endif
                }
        }
        ifnet_lock_done(ifp);
        ifnet_head_done();
#if PF
        /*
         * Attach packet filter to this interface, if enaled.
         */
        pf_ifnet_hook(ifp, 1);
#endif /* PF */
        dlil_write_end();

#if IFNET_ROUTE_REFCNT
        if (net_rtref) {
                (void) ifnet_set_idle_flags(ifp, IFRF_IDLE_NOTIFY,
                    IFRF_IDLE_NOTIFY);
        }
#endif /* IFNET_ROUTE_REFCNT */

        dlil_post_msg(ifp, KEV_DL_SUBCLASS, KEV_DL_IF_ATTACHED, NULL, 0);

    return 0;
}

errno_t
ifnet_detach(
        ifnet_t ifp)
{
        struct ifnet_filter *filter;
        struct ifnet_filter     *filter_next;
        int zeroed = 0;
        int retval = 0;
        struct ifnet_filter_head fhead;
        struct dlil_threading_info *inputthread;
        
        if (ifp == NULL) return EINVAL;
        
        ifnet_lock_exclusive(ifp);
        
        if ((ifp->if_eflags & IFEF_DETACHING) != 0) {
                /* Interface has already been detached */
                ifnet_lock_done(ifp);
                return ENXIO;
        }
        
        /*
         * Indicate this interface is being detached.
         * 
         * This should prevent protocols from attaching
         * from this point on. Interface will remain on
         * the list until all of the protocols are detached.
         */
        ifp->if_eflags |= IFEF_DETACHING;
        ifnet_lock_done(ifp);
        
        dlil_post_msg(ifp, KEV_DL_SUBCLASS, KEV_DL_IF_DETACHING, NULL, 0);
        
        /* Let BPF know we're detaching */
        bpfdetach(ifp);
        
#if IFNET_ROUTE_REFCNT
        /*
         * Check to see if this interface has previously triggered
         * aggressive protocol draining; if so, decrement the global
         * refcnt and clear PR_AGGDRAIN on the route domain if
         * there are no more of such an interface around.
         */
         if (ifp->if_want_aggressive_drain != 0)
                (void) ifnet_set_idle_flags(ifp, 0, ~0);
#endif /* IFNET_ROUTE_REFCNT */

        if ((retval = dlil_write_begin()) != 0) {
                if (retval == EDEADLK) {
                        retval = 0;
                        
                        /* We need to perform a delayed detach */
                        ifp->if_delayed_detach = 1;
                        dlil_detach_waiting = 1;
                        wakeup(&dlil_detach_waiting);
                }
                return retval;
        }

#if PF
        /*
         * Detach this interface from packet filter, if enabled.
         */
        pf_ifnet_hook(ifp, 0);
#endif /* PF */

        /* Steal the list of interface filters */
        fhead = ifp->if_flt_head;
        TAILQ_INIT(&ifp->if_flt_head);

        /* unuse the interface */
        zeroed = ifp_unuse(ifp);

        /*
         * If thread affinity was set for the workloop thread, we will need
         * to tear down the affinity and release the extra reference count
         * taken at attach time;
         */
        if ((inputthread = ifp->if_input_thread) != NULL) {
                if (inputthread->net_affinity) {
                        struct thread *tp;

                        if (inputthread == dlil_lo_thread_ptr)
                                panic("Thread affinity should not be enabled "
                                    "on the loopback dlil input thread\n");

                        lck_mtx_lock(inputthread->input_lck);
                        tp = inputthread->workloop_thread;
                        inputthread->workloop_thread = NULL;
                        inputthread->tag = 0;
                        inputthread->net_affinity = FALSE;
                        lck_mtx_unlock(inputthread->input_lck);

                        /* Tear down workloop thread affinity */
                        if (tp != NULL) {
                                (void) dlil_affinity_set(tp,
                                    THREAD_AFFINITY_TAG_NULL);
                                thread_deallocate(tp);
                        }

                        /* Tear down dlil input thread affinity */
                        tp = inputthread->input_thread;
                        (void) dlil_affinity_set(tp, THREAD_AFFINITY_TAG_NULL);
                        thread_deallocate(tp);
                }

                /* cleanup ifp dlil input thread, if any */
                ifp->if_input_thread = NULL;

                if (inputthread != dlil_lo_thread_ptr) {
#ifdef DLIL_DEBUG
                        printf("ifnet_detach: wakeup thread threadinfo: %p "
                            "input_thread=%p threads: cur=%d max=%d\n",
                            inputthread, inputthread->input_thread,
                            dlil_multithreaded_input, cur_dlil_input_threads);
#endif
                        lck_mtx_lock(inputthread->input_lck);

                        inputthread->input_waiting |= DLIL_INPUT_TERMINATE;
                        if ((inputthread->input_waiting & DLIL_INPUT_RUNNING) == 0) {
                                wakeup((caddr_t)&inputthread->input_waiting);
                        }
                        lck_mtx_unlock(inputthread->input_lck);
                }
        }
        /* last chance to clean up IPv4 forwarding cached route */
        lck_mtx_lock(ifp->if_fwd_route_lock);
        if (ifp->if_fwd_route.ro_rt != NULL) {
                rtfree(ifp->if_fwd_route.ro_rt);
                ifp->if_fwd_route.ro_rt = NULL;
        }
        lck_mtx_unlock(ifp->if_fwd_route_lock);
        dlil_write_end();
        
        for (filter = TAILQ_FIRST(&fhead); filter; filter = filter_next) {
                filter_next = TAILQ_NEXT(filter, filt_next);
                dlil_detach_filter_internal(filter, 1);
        }
        
        if (zeroed != 0) {
                ifp_use_reached_zero(ifp);
        }
        
        return retval;
}

static errno_t
dlil_recycle_ioctl(
        __unused ifnet_t ifnet_ptr,
        __unused u_long ioctl_code,
        __unused void *ioctl_arg)
{
    return EOPNOTSUPP;
}

static int
dlil_recycle_output(
        __unused struct ifnet *ifnet_ptr,
        struct mbuf *m)
{
    m_freem(m);
    return 0;
}

static void
dlil_recycle_free(
        __unused ifnet_t ifnet_ptr)
{
}

static errno_t
dlil_recycle_set_bpf_tap(
        __unused ifnet_t ifp,
        __unused bpf_tap_mode mode,
        __unused bpf_packet_func callback)
{
    /* XXX not sure what to do here */
    return 0;
}

__private_extern__
int dlil_if_acquire(
        u_int32_t family,
        const void *uniqueid,
        size_t uniqueid_len, 
        struct ifnet **ifp)
{
    struct ifnet        *ifp1 = NULL;
    struct dlil_ifnet   *dlifp1 = NULL;
    int ret = 0;

    lck_mtx_lock(dlil_ifnet_mutex);
    TAILQ_FOREACH(dlifp1, &dlil_ifnet_head, dl_if_link) {
        
        ifp1 = (struct ifnet *)dlifp1;
            
                if (ifp1->if_family == family)  {
        
            /* same uniqueid and same len or no unique id specified */
            if ((uniqueid_len == dlifp1->if_uniqueid_len)
                && !bcmp(uniqueid, dlifp1->if_uniqueid, uniqueid_len)) {
                
                                /* check for matching interface in use */
                                if (ifp1->if_eflags & IFEF_INUSE) {
                                        if (uniqueid_len) {
                                                ret = EBUSY;
                                                goto end;
                                        }
                                }
                                else {
                                        if (!ifp1->if_lock)
                                                panic("ifp's lock is gone\n");
                                        ifnet_lock_exclusive(ifp1);
                                        ifp1->if_eflags |= (IFEF_INUSE | IFEF_REUSE);
                                        ifnet_lock_done(ifp1);
                                        *ifp = ifp1;
                                        goto end;
                }
            }
        }
    }

    /* no interface found, allocate a new one */
    MALLOC(dlifp1, struct dlil_ifnet *, sizeof(*dlifp1), M_NKE, M_WAITOK);
    if (dlifp1 == 0) {
        ret = ENOMEM;
        goto end;
    }
    
    bzero(dlifp1, sizeof(*dlifp1));
    
    if (uniqueid_len) {
        MALLOC(dlifp1->if_uniqueid, void *, uniqueid_len, M_NKE, M_WAITOK);
        if (dlifp1->if_uniqueid == 0) {
            FREE(dlifp1, M_NKE);
            ret = ENOMEM;
           goto end;
        }
        bcopy(uniqueid, dlifp1->if_uniqueid, uniqueid_len);
        dlifp1->if_uniqueid_len = uniqueid_len;
    }

    ifp1 = (struct ifnet *)dlifp1;
    ifp1->if_eflags |= IFEF_INUSE;
    ifp1->if_name = dlifp1->if_namestorage;
#if CONFIG_MACF_NET
    mac_ifnet_label_init(ifp1);
#endif

    TAILQ_INSERT_TAIL(&dlil_ifnet_head, dlifp1, dl_if_link);
     
     *ifp = ifp1;

end:
        lck_mtx_unlock(dlil_ifnet_mutex);

    return ret;
}

__private_extern__ void
dlil_if_release(
        ifnet_t ifp)
{
    struct dlil_ifnet   *dlifp = (struct dlil_ifnet *)ifp;
    
    /* Interface does not have a lock until it is attached - radar 3713951 */
    if (ifp->if_lock)
                ifnet_lock_exclusive(ifp);
    ifp->if_eflags &= ~IFEF_INUSE;
    ifp->if_ioctl = dlil_recycle_ioctl;
    ifp->if_output = dlil_recycle_output;
    ifp->if_free = dlil_recycle_free;
    ifp->if_set_bpf_tap = dlil_recycle_set_bpf_tap;

    strncpy(dlifp->if_namestorage, ifp->if_name, IFNAMSIZ);
    ifp->if_name = dlifp->if_namestorage;
#if CONFIG_MACF_NET
    /*
     * We can either recycle the MAC label here or in dlil_if_acquire().
     * It seems logical to do it here but this means that anything that
     * still has a handle on ifp will now see it as unlabeled.
     * Since the interface is "dead" that may be OK.  Revisit later.
     */
    mac_ifnet_label_recycle(ifp);
#endif
    if (ifp->if_lock)
                ifnet_lock_done(ifp);
    
}

__private_extern__ void
dlil_proto_unplumb_all(struct ifnet *ifp)
{
        /*
         * if_proto_hash[0-3] are for PF_INET, PF_INET6, PF_APPLETALK
         * and PF_VLAN, where each bucket contains exactly one entry;
         * PF_VLAN does not need an explicit unplumb.
         *
         * if_proto_hash[4] is for other protocols; we expect anything
         * in this bucket to respond to the DETACHING event (which would
         * have happened by now) and do the unplumb then.
         */
        (void) proto_unplumb(PF_INET, ifp);
#if INET6
        (void) proto_unplumb(PF_INET6, ifp);
#endif /* INET6 */
#if NETAT
        (void) proto_unplumb(PF_APPLETALK, ifp);
#endif /* NETAT */
}