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

/*
 * Copyright (c) 1997-2008, 2012 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@
 */
/*
 *      @(#)ndrv.c      1.1 (MacOSX) 6/10/43
 * Justin Walker, 970604
 *   AF_NDRV support
 * 980130 - Cleanup, reorg, performance improvemements
 * 000816 - Removal of Y adapter cruft
 */

/*
 * PF_NDRV allows raw access to a specified network device, directly
 *  with a socket.  Expected use involves a socket option to request
 *  protocol packets.  This lets ndrv_output() call ifnet_output(), and
 *  lets DLIL find the proper recipient for incoming packets.
 *  The purpose here is for user-mode protocol implementation.
 * Note that "pure raw access" will still be accomplished with BPF.
 *
 * In addition to the former use, when combined with socket NKEs,
 * PF_NDRV permits a fairly flexible mechanism for implementing
 * strange protocol support.
 */
#include <mach/mach_types.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/domain.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <sys/errno.h>
#include <sys/syslog.h>
#include <sys/proc.h>

#include <kern/queue.h>

#include <net/ndrv.h>
#include <net/route.h>
#include <net/if_llc.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/ndrv_var.h>
#include <net/dlil.h>

#if INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#endif
#include <netinet/if_ether.h>

#include <machine/spl.h>

static unsigned int ndrv_multi_max_count = NDRV_DMUX_MAX_DESCR;
SYSCTL_UINT(_net, OID_AUTO, ndrv_multi_max_count, CTLFLAG_RW | CTLFLAG_LOCKED,
        &ndrv_multi_max_count, 0, "Number of allowed multicast addresses per NRDV socket");

static int ndrv_do_detach(struct ndrv_cb *);
static int ndrv_do_disconnect(struct ndrv_cb *);
static struct ndrv_cb *ndrv_find_inbound(struct ifnet *ifp, u_int32_t protocol_family);
static int ndrv_setspec(struct ndrv_cb *np, struct sockopt *sopt);
static int ndrv_delspec(struct ndrv_cb *);
static int ndrv_to_ifnet_demux(struct ndrv_demux_desc* ndrv, struct ifnet_demux_desc* ifdemux);
static void ndrv_handle_ifp_detach(u_int32_t family, short unit);
static int ndrv_do_add_multicast(struct ndrv_cb *np, struct sockopt *sopt);
static int ndrv_do_remove_multicast(struct ndrv_cb *np, struct sockopt *sopt);
static struct ndrv_multiaddr* ndrv_have_multicast(struct ndrv_cb *np, struct sockaddr* addr);
static void ndrv_remove_all_multicast(struct ndrv_cb *np);
static void ndrv_dominit(void) __attribute__((section("__TEXT, initcode")));

u_int32_t  ndrv_sendspace = NDRVSNDQ;
u_int32_t  ndrv_recvspace = NDRVRCVQ;
TAILQ_HEAD(, ndrv_cb)   ndrvl = TAILQ_HEAD_INITIALIZER(ndrvl);

extern struct domain ndrvdomain;
extern struct protosw ndrvsw;

#define NDRV_PROTODEMUX_COUNT   10

/*
 * Verify these values match.
 * To keep clients from including dlil.h, we define
 * these values independently in ndrv.h. They must
 * match or a conversion function must be written.
 */
#if NDRV_DEMUXTYPE_ETHERTYPE != DLIL_DESC_ETYPE2
#error NDRV_DEMUXTYPE_ETHERTYPE must match DLIL_DESC_ETYPE2
#endif
#if NDRV_DEMUXTYPE_SAP != DLIL_DESC_SAP
#error NDRV_DEMUXTYPE_SAP must match DLIL_DESC_SAP
#endif
#if NDRV_DEMUXTYPE_SNAP != DLIL_DESC_SNAP
#error NDRV_DEMUXTYPE_SNAP must match DLIL_DESC_SNAP
#endif

/*
 * Protocol output - Called to output a raw network packet directly
 *  to the driver.
 */
static int
ndrv_output(struct mbuf *m, struct socket *so)
{
    struct ndrv_cb *np = sotondrvcb(so);
        struct ifnet *ifp = np->nd_if;
    int result = 0;

#if NDRV_DEBUG
        kprintf("NDRV output: %x, %x, %x\n", m, so, np);
#endif

        /*
         * No header is a format error
         */
        if ((m->m_flags&M_PKTHDR) == 0)
                return(EINVAL);

        /* Unlock before calling ifnet_output */
        socket_unlock(so, 0);
        
        /*
     * Call DLIL if we can. DLIL is much safer than calling the
     * ifp directly.
     */
        result = ifnet_output_raw(ifp, np->nd_proto_family, m);
        
        socket_lock(so, 0);
        
        return (result);
}

/* Our input routine called from DLIL */
static errno_t
ndrv_input(
        ifnet_t                         ifp,
        protocol_family_t       proto_family,
        mbuf_t                          m,
        char                            *frame_header)
{
        struct socket *so;
        struct sockaddr_dl ndrvsrc;
        struct ndrv_cb *np;
        int error = 0;

    ndrvsrc.sdl_len = sizeof (struct sockaddr_dl);
    ndrvsrc.sdl_family = AF_NDRV;
    ndrvsrc.sdl_index = 0;

    /* move packet from if queue to socket */
        /* Should be media-independent */
    ndrvsrc.sdl_type = IFT_ETHER;
    ndrvsrc.sdl_nlen = 0;
    ndrvsrc.sdl_alen = 6;
    ndrvsrc.sdl_slen = 0;
    bcopy(frame_header, &ndrvsrc.sdl_data, 6);

        np = ndrv_find_inbound(ifp, proto_family);
        if (np == NULL)
        {
                return(ENOENT);
        }
        so = np->nd_socket;
    /* prepend the frame header */
    m = m_prepend(m, ifnet_hdrlen(ifp), M_NOWAIT);
    if (m == NULL)
        return EJUSTRETURN;
    bcopy(frame_header, m->m_data, ifnet_hdrlen(ifp));

        lck_mtx_assert(so->so_proto->pr_domain->dom_mtx, LCK_MTX_ASSERT_NOTOWNED);
        lck_mtx_lock(so->so_proto->pr_domain->dom_mtx);
        if (sbappendaddr(&(so->so_rcv), (struct sockaddr *)&ndrvsrc,
                                         m, (struct mbuf *)0, &error) != 0) {
                sorwakeup(so);
        }
        lck_mtx_unlock(so->so_proto->pr_domain->dom_mtx);
        return 0; /* radar 4030377 - always return 0 */
}

/*
 * Allocate an ndrv control block and some buffer space for the socket
 */
static int
ndrv_attach(struct socket *so, int proto, __unused struct proc *p)
{
    int error;
        struct ndrv_cb *np = sotondrvcb(so);

        if ((so->so_state & SS_PRIV) == 0)
                return(EPERM);

#if NDRV_DEBUG
        kprintf("NDRV attach: %x, %x, %x\n", so, proto, np);
#endif

        if ((error = soreserve(so, ndrv_sendspace, ndrv_recvspace)))
                return(error);

        MALLOC(np, struct ndrv_cb *, sizeof(*np), M_PCB, M_WAITOK);
        if (np == NULL)
                return (ENOMEM);
    so->so_pcb = (caddr_t)np;
    bzero(np, sizeof(*np));
#if NDRV_DEBUG
        kprintf("NDRV attach: %x, %x, %x\n", so, proto, np);
#endif
        TAILQ_INIT(&np->nd_dlist);
        np->nd_signature = NDRV_SIGNATURE;
        np->nd_socket = so;
        np->nd_proto.sp_family = so->so_proto->pr_domain->dom_family;
        np->nd_proto.sp_protocol = proto;
    np->nd_if = NULL;
    np->nd_proto_family = 0;
    np->nd_family = 0;
    np->nd_unit = 0;
    TAILQ_INSERT_TAIL(&ndrvl, np, nd_next);
        return(0);
}

/*
 * Destroy state just before socket deallocation.
 * Flush data or not depending on the options.
 */

static int
ndrv_detach(struct socket *so)
{
        struct ndrv_cb *np = sotondrvcb(so);

        if (np == 0)
                return EINVAL;
        return ndrv_do_detach(np);
}


/*
 * If a socket isn't bound to a single address,
 * the ndrv input routine will hand it anything
 * within that protocol family (assuming there's
 * nothing else around it should go to).
 *
 * Don't expect this to be used.
 */

static int
ndrv_connect(struct socket *so, struct sockaddr *nam, __unused struct proc *p)
{
        struct ndrv_cb *np = sotondrvcb(so);

        if (np == 0)
                return EINVAL;

        if (np->nd_faddr)
                return EISCONN;
    
        /* Allocate memory to store the remote address */
        MALLOC(np->nd_faddr, struct sockaddr_ndrv*,
                nam->sa_len, M_IFADDR, M_WAITOK);
        if (np->nd_faddr == NULL)
                return ENOMEM;
    
        bcopy((caddr_t) nam, (caddr_t) np->nd_faddr, nam->sa_len);
        soisconnected(so);
        return 0;
}

static void
ndrv_event(struct ifnet *ifp, __unused protocol_family_t protocol,
                   const struct kev_msg *event)
{
        if (event->vendor_code == KEV_VENDOR_APPLE &&
                event->kev_class == KEV_NETWORK_CLASS &&
                event->kev_subclass == KEV_DL_SUBCLASS &&
                event->event_code == KEV_DL_IF_DETACHING) {
                lck_mtx_assert(ndrvdomain.dom_mtx, LCK_MTX_ASSERT_NOTOWNED);
                lck_mtx_lock(ndrvdomain.dom_mtx);
                ndrv_handle_ifp_detach(ifnet_family(ifp), ifnet_unit(ifp));
                lck_mtx_unlock(ndrvdomain.dom_mtx);
        }
}

static int name_cmp(struct ifnet *, char *);

/*
 * This is the "driver open" hook - we 'bind' to the
 *  named driver.
 * Here's where we latch onto the driver.
 */
static int
ndrv_bind(struct socket *so, struct sockaddr *nam, __unused struct proc *p)
{
    struct sockaddr_ndrv *sa = (struct sockaddr_ndrv *) nam;
        char *dname;
        struct ndrv_cb *np;
        struct ifnet *ifp;
    int result;

        if TAILQ_EMPTY(&ifnet_head)
                return(EADDRNOTAVAIL); /* Quick sanity check */
        np = sotondrvcb(so);
        if (np == 0)
                return EINVAL;

        if (np->nd_laddr)
                return EINVAL;                  /* XXX */

        /* I think we just latch onto a copy here; the caller frees */
        np->nd_laddr = _MALLOC(sizeof(struct sockaddr_ndrv), M_IFADDR, M_WAITOK);
        if (np->nd_laddr == NULL)
                return(ENOMEM);
        bcopy((caddr_t) sa, (caddr_t) np->nd_laddr, sizeof(struct sockaddr_ndrv));
        dname = (char *) sa->snd_name;
        if (*dname == '\0')
                return(EINVAL);
#if NDRV_DEBUG
        kprintf("NDRV bind: %x, %x, %s\n", so, np, dname);
#endif
        /* Track down the driver and its ifnet structure.
         * There's no internal call for this so we have to dup the code
         *  in if.c/ifconf()
         */
        ifnet_head_lock_shared();
        TAILQ_FOREACH(ifp, &ifnet_head, if_link) {
                if (name_cmp(ifp, dname) == 0)
                        break;
        }
        ifnet_head_done();

        if (ifp == NULL)
                return(EADDRNOTAVAIL);
        
        // PPP doesn't support PF_NDRV.
        if (ifnet_family(ifp) != APPLE_IF_FAM_PPP)
        {
                /* NDRV on this interface */
                struct ifnet_attach_proto_param ndrv_proto;
                result = 0;
                bzero(&ndrv_proto, sizeof(ndrv_proto));
                ndrv_proto.event = ndrv_event;
                
                /* We aren't worried about double attaching, that should just return an error */
                socket_unlock(so, 0);
                result = ifnet_attach_protocol(ifp, PF_NDRV, &ndrv_proto);
                socket_lock(so, 0);
                if (result && result != EEXIST) {
                        return result;
                }
                np->nd_proto_family = PF_NDRV;
        }
        else {
                np->nd_proto_family = 0;
        }
    
        np->nd_if = ifp;
    np->nd_family = ifnet_family(ifp);
    np->nd_unit = ifnet_unit(ifp);
    
        return(0);
}

static int
ndrv_disconnect(struct socket *so)
{
        struct ndrv_cb *np = sotondrvcb(so);

        if (np == 0)
                return EINVAL;

        if (np->nd_faddr == 0)
                return ENOTCONN;

        ndrv_do_disconnect(np);
        return 0;
}

/*
 * Mark the connection as being incapable of further input.
 */
static int
ndrv_shutdown(struct socket *so)
{
        lck_mtx_assert(so->so_proto->pr_domain->dom_mtx, LCK_MTX_ASSERT_OWNED);
        socantsendmore(so);
        return 0;
}

/*
 * Ship a packet out.  The ndrv output will pass it
 *  to the appropriate driver.  The really tricky part
 *  is the destination address...
 */
static int
ndrv_send(struct socket *so, __unused int flags, struct mbuf *m,
          __unused struct sockaddr *addr, struct mbuf *control,
          __unused struct proc *p)
{
        int error;

        if (control)
                return EOPNOTSUPP;

        error = ndrv_output(m, so);
        m = NULL;
        return error;
}


static int
ndrv_abort(struct socket *so)
{
        struct ndrv_cb *np = sotondrvcb(so);

        if (np == 0)
                return EINVAL;

        ndrv_do_disconnect(np);
        return 0;
}

static int
ndrv_sockaddr(struct socket *so, struct sockaddr **nam)
{
        struct ndrv_cb *np = sotondrvcb(so);
        int len;

        if (np == 0)
                return EINVAL;

        if (np->nd_laddr == 0)
                return EINVAL;

        len = np->nd_laddr->snd_len;
        MALLOC(*nam, struct sockaddr *, len, M_SONAME, M_WAITOK);
        if (*nam == NULL)
                return ENOMEM;
        bcopy((caddr_t)np->nd_laddr, *nam,
              (unsigned)len);
        return 0;
}


static int
ndrv_peeraddr(struct socket *so, struct sockaddr **nam)
{
        struct ndrv_cb *np = sotondrvcb(so);
        int len;

        if (np == 0)
                return EINVAL;

        if (np->nd_faddr == 0)
                return ENOTCONN;

        len = np->nd_faddr->snd_len;
        MALLOC(*nam, struct sockaddr *, len, M_SONAME, M_WAITOK);
        if (*nam == NULL)
                return ENOMEM;
        bcopy((caddr_t)np->nd_faddr, *nam,
              (unsigned)len);
        return 0;
}


/* Control output */

static int
ndrv_ctloutput(struct socket *so, struct sockopt *sopt)
{
    struct ndrv_cb *np = sotondrvcb(so);
        int error = 0;
    
    switch(sopt->sopt_name)
    {
        case NDRV_DELDMXSPEC: /* Delete current spec */
            /* Verify no parameter was passed */
            if (sopt->sopt_val != 0 || sopt->sopt_valsize != 0) {
                /*
                 * We don't support deleting a specific demux, it's
                 * all or nothing.
                 */
                return EINVAL;
            }
            error = ndrv_delspec(np);
            break;
        case NDRV_SETDMXSPEC: /* Set protocol spec */
            error = ndrv_setspec(np, sopt);
            break;
        case NDRV_ADDMULTICAST:
            error = ndrv_do_add_multicast(np, sopt);
            break;
        case NDRV_DELMULTICAST:
            error = ndrv_do_remove_multicast(np, sopt);
            break;
        default:
            error = ENOTSUP;
    }
#ifdef NDRV_DEBUG
        log(LOG_WARNING, "NDRV CTLOUT: %x returns %d\n", sopt->sopt_name,
            error);
#endif
        return(error);
}

static int
ndrv_do_detach(struct ndrv_cb *np)
{
    struct ndrv_cb*     cur_np = NULL;
    struct socket *so = np->nd_socket;
    int error = 0;
    struct ifnet * ifp;

#if NDRV_DEBUG
        kprintf("NDRV detach: %x, %x\n", so, np);
#endif
    ndrv_remove_all_multicast(np);

    ifp = np->nd_if;
    /* Remove from the linked list of control blocks */
    TAILQ_REMOVE(&ndrvl, np, nd_next);
    if (ifp != NULL) {
                u_int32_t proto_family = np->nd_proto_family;

                if (proto_family != PF_NDRV && proto_family != 0) {
                        socket_unlock(so, 0);
                        ifnet_detach_protocol(ifp, proto_family);
                        socket_lock(so, 0);
                }
                
                /* Check if this is the last socket attached to this interface */
                TAILQ_FOREACH(cur_np, &ndrvl, nd_next) {
                        if (cur_np->nd_family == np->nd_family &&
                                cur_np->nd_unit == np->nd_unit) {
                                break;
                        }
                }
                
                /* If there are no other interfaces, detach PF_NDRV from the interface */
                if (cur_np == NULL) {
                        socket_unlock(so, 0);
                        ifnet_detach_protocol(ifp, PF_NDRV);
                        socket_lock(so, 0);
                }
        }
        if (np->nd_laddr != NULL) {
                FREE((caddr_t)np->nd_laddr, M_IFADDR);
                np->nd_laddr = NULL;
        }
        FREE((caddr_t)np, M_PCB);
        so->so_pcb = 0;
        so->so_flags |= SOF_PCBCLEARING;
        sofree(so);
        return error;
}

static int
ndrv_do_disconnect(struct ndrv_cb *np)
{
        struct socket * so = np->nd_socket;
#if NDRV_DEBUG
        kprintf("NDRV disconnect: %x\n", np);
#endif
        if (np->nd_faddr)
        {
        FREE(np->nd_faddr, M_IFADDR);
                np->nd_faddr = 0;
        }
        if (so->so_state & SS_NOFDREF)
                ndrv_do_detach(np);
        soisdisconnected(so);
        return(0);
}

/* Hackery - return a string version of a decimal number */
static void
sprint_d(u_int n, char *buf, int buflen)
{       char dbuf[IFNAMSIZ];
        char *cp = dbuf+IFNAMSIZ-1;

        *cp = 0;
        do {    buflen--;
                cp--;
                *cp = "0123456789"[n % 10];
                n /= 10;
        } while (n != 0 && buflen > 0);
        strncpy(buf, cp, IFNAMSIZ-buflen);
        return;
}

/*
 * Try to compare a device name (q) with one of the funky ifnet
 *  device names (ifp).
 */
static int name_cmp(struct ifnet *ifp, char *q)
{       char *r;
        int len;
        char buf[IFNAMSIZ];

        r = buf;
        len = strlen(ifnet_name(ifp));
        strncpy(r, ifnet_name(ifp), IFNAMSIZ);
        r += len;
        sprint_d(ifnet_unit(ifp), r, IFNAMSIZ-(r-buf));
#if NDRV_DEBUG
        kprintf("Comparing %s, %s\n", buf, q);
#endif
        return(strncmp(buf, q, IFNAMSIZ));
}

#if 0
//### Not used
/*
 * When closing, dump any enqueued mbufs.
 */
void
ndrv_flushq(struct ifqueue *q)
{
    struct mbuf *m;
        for (;;)
        {
                IF_DEQUEUE(q, m);
                if (m == NULL)
                        break;
                IF_DROP(q);
                if (m)
                        m_freem(m);
        }
}
#endif 

int
ndrv_setspec(struct ndrv_cb *np, struct sockopt *sopt)
{
        struct ifnet_attach_proto_param proto_param;
        struct ndrv_protocol_desc       ndrvSpec;
        struct ndrv_demux_desc*         ndrvDemux = NULL;
        int                                                     error = 0;
        struct socket *                         so = np->nd_socket; 
        user_addr_t                                     user_addr;
        
        /* Sanity checking */
        if (np->nd_proto_family != PF_NDRV)
                return EBUSY;
        if (np->nd_if == NULL)
                return EINVAL;

        /* Copy the ndrvSpec */
        if (proc_is64bit(sopt->sopt_p)) {
                struct ndrv_protocol_desc64     ndrvSpec64;

                if (sopt->sopt_valsize != sizeof(ndrvSpec64))
                        return EINVAL;
        
                error = sooptcopyin(sopt, &ndrvSpec64, sizeof(ndrvSpec64), sizeof(ndrvSpec64));
                if (error != 0)
                        return error;

                ndrvSpec.version         = ndrvSpec64.version;
                ndrvSpec.protocol_family = ndrvSpec64.protocol_family;
                ndrvSpec.demux_count     = ndrvSpec64.demux_count;

                user_addr = ndrvSpec64.demux_list;
        }
        else {
                struct ndrv_protocol_desc32     ndrvSpec32;

                if (sopt->sopt_valsize != sizeof(ndrvSpec32))
                        return EINVAL;
        
                error = sooptcopyin(sopt, &ndrvSpec32, sizeof(ndrvSpec32), sizeof(ndrvSpec32));
                if (error != 0)
                        return error;

                ndrvSpec.version         = ndrvSpec32.version;
                ndrvSpec.protocol_family = ndrvSpec32.protocol_family;
                ndrvSpec.demux_count     = ndrvSpec32.demux_count;

                user_addr = CAST_USER_ADDR_T(ndrvSpec32.demux_list);
        }
        
        /* Verify the parameter */
        if (ndrvSpec.version > NDRV_PROTOCOL_DESC_VERS)
                return ENOTSUP; // version is too new!
        else if (ndrvSpec.version < 1)
                return EINVAL; // version is not valid
        else if (ndrvSpec.demux_count > NDRV_PROTODEMUX_COUNT || ndrvSpec.demux_count == 0)
                return EINVAL; // demux_count is not valid
        
        bzero(&proto_param, sizeof(proto_param));
        proto_param.demux_count = ndrvSpec.demux_count;
        
        /* Allocate storage for demux array */
        MALLOC(ndrvDemux, struct ndrv_demux_desc*, proto_param.demux_count *
                   sizeof(struct ndrv_demux_desc), M_TEMP, M_WAITOK);
        if (ndrvDemux == NULL)
                return ENOMEM;
        
        /* Allocate enough ifnet_demux_descs */
        MALLOC(proto_param.demux_array, struct ifnet_demux_desc*,
                   sizeof(*proto_param.demux_array) * ndrvSpec.demux_count,
                   M_TEMP, M_WAITOK);
        if (proto_param.demux_array == NULL)
                error = ENOMEM;
        
        if (error == 0)
        {
                /* Copy the ndrv demux array from userland */
                error = copyin(user_addr, ndrvDemux,
                                           ndrvSpec.demux_count * sizeof(struct ndrv_demux_desc));
                ndrvSpec.demux_list = ndrvDemux;
        }
        
        if (error == 0)
        {
                /* At this point, we've at least got enough bytes to start looking around */
                u_int32_t       demuxOn = 0;
                
                proto_param.demux_count = ndrvSpec.demux_count;
                proto_param.input = ndrv_input;
                proto_param.event = ndrv_event;
                
                for (demuxOn = 0; demuxOn < ndrvSpec.demux_count; demuxOn++)
                {
                        /* Convert an ndrv_demux_desc to a ifnet_demux_desc */
                        error = ndrv_to_ifnet_demux(&ndrvSpec.demux_list[demuxOn],
                                                                                &proto_param.demux_array[demuxOn]);
                        if (error)
                                break;
                }
        }
        
        if (error == 0)
        {
                /* We've got all our ducks lined up...lets attach! */
                socket_unlock(so, 0);
                error = ifnet_attach_protocol(np->nd_if, ndrvSpec.protocol_family,
                                                                          &proto_param);
                socket_lock(so, 0);
                if (error == 0)
                        np->nd_proto_family = ndrvSpec.protocol_family;
        }
        
        /* Free any memory we've allocated */
        if (proto_param.demux_array)
                FREE(proto_param.demux_array, M_TEMP);
        if (ndrvDemux)
                FREE(ndrvDemux, M_TEMP);
        
        return error;
}


int
ndrv_to_ifnet_demux(struct ndrv_demux_desc* ndrv, struct ifnet_demux_desc* ifdemux)
{
    bzero(ifdemux, sizeof(*ifdemux));
    
    if (ndrv->type < DLIL_DESC_ETYPE2)
    {
        /* using old "type", not supported */
        return ENOTSUP;
    }
    
    if (ndrv->length > 28)
    {
        return EINVAL;
    }
    
    ifdemux->type = ndrv->type;
    ifdemux->data = ndrv->data.other;
    ifdemux->datalen = ndrv->length;
    
    return 0;
}

int
ndrv_delspec(struct ndrv_cb *np)
{
    int result = 0;
    
    if (np->nd_proto_family == PF_NDRV ||
        np->nd_proto_family == 0)
        return EINVAL;
    
    /* Detach the protocol */
    result = ifnet_detach_protocol(np->nd_if, np->nd_proto_family);
    np->nd_proto_family = PF_NDRV;
    
        return result;
}

struct ndrv_cb *
ndrv_find_inbound(struct ifnet *ifp, u_int32_t protocol)
{
    struct ndrv_cb* np;
        
        if (protocol == PF_NDRV) return NULL;
    
    TAILQ_FOREACH(np, &ndrvl, nd_next) {
        if (np->nd_proto_family == protocol &&
                np->nd_if == ifp) {
            return np;
        }
    }
    
        return NULL;
}

static void ndrv_dominit(void)
{
        static int ndrv_dominited = 0;

        if (ndrv_dominited == 0 &&
            net_add_proto(&ndrvsw, &ndrvdomain) == 0)
                ndrv_dominited = 1;
}

static void
ndrv_handle_ifp_detach(u_int32_t family, short unit)
{
    struct ndrv_cb* np;
    struct ifnet        *ifp = NULL;
    struct socket *so;
    
    /* Find all sockets using this interface. */
    TAILQ_FOREACH(np, &ndrvl, nd_next) {
        if (np->nd_family == family &&
            np->nd_unit == unit)
        {
            /* This cb is using the detaching interface, but not for long. */
            /* Let the protocol go */
            ifp = np->nd_if;
            if (np->nd_proto_family != 0)
                ndrv_delspec(np);
            
            /* Delete the multicasts first */
            ndrv_remove_all_multicast(np);
            
            /* Disavow all knowledge of the ifp */
            np->nd_if = NULL;
            np->nd_unit = 0;
            np->nd_family = 0;
           
                  so = np->nd_socket; 
            /* Make sure sending returns an error */
            /* Is this safe? Will we drop the funnel? */
                  lck_mtx_assert(so->so_proto->pr_domain->dom_mtx, LCK_MTX_ASSERT_OWNED);
            socantsendmore(so);
            socantrcvmore(so);
        }
    }
    
    /* Unregister our protocol */
    if (ifp) {
        ifnet_detach_protocol(ifp, PF_NDRV);
    }
}

static int
ndrv_do_add_multicast(struct ndrv_cb *np, struct sockopt *sopt)
{
    struct ndrv_multiaddr*      ndrv_multi;
    int                                         result;
    
    if (sopt->sopt_val == 0 || sopt->sopt_valsize < 2 ||
        sopt->sopt_level != SOL_NDRVPROTO || sopt->sopt_valsize > SOCK_MAXADDRLEN)
        return EINVAL;
    if (np->nd_if == NULL)
        return ENXIO;
        if (!(np->nd_dlist_cnt < ndrv_multi_max_count))
                return EPERM;
    
    // Allocate storage
    MALLOC(ndrv_multi, struct ndrv_multiaddr*, sizeof(struct ndrv_multiaddr) -
        sizeof(struct sockaddr) + sopt->sopt_valsize, M_IFADDR, M_WAITOK);
    if (ndrv_multi == NULL)
        return ENOMEM;
    
    // Copy in the address
    result = copyin(sopt->sopt_val, &ndrv_multi->addr, sopt->sopt_valsize);
    
    // Validate the sockaddr
    if (result == 0 && sopt->sopt_valsize != ndrv_multi->addr.sa_len)
        result = EINVAL;
    
    if (result == 0 && ndrv_have_multicast(np, &ndrv_multi->addr))
        result = EEXIST;
    
    if (result == 0)
    {
        // Try adding the multicast
        result = ifnet_add_multicast(np->nd_if, &ndrv_multi->addr,
                                                                 &ndrv_multi->ifma);
    }
    
    if (result == 0)
    {
        // Add to our linked list
        ndrv_multi->next = np->nd_multiaddrs;
        np->nd_multiaddrs = ndrv_multi;
                np->nd_dlist_cnt++;
    }
    else
    {
        // Free up the memory, something went wrong
        FREE(ndrv_multi, M_IFADDR);
    }
    
    return result;
}

static int
ndrv_do_remove_multicast(struct ndrv_cb *np, struct sockopt *sopt)
{
    struct sockaddr*            multi_addr;
    struct ndrv_multiaddr*      ndrv_entry = NULL;
    int                                 result;
    
    if (sopt->sopt_val == 0 || sopt->sopt_valsize < 2 ||
        sopt->sopt_level != SOL_NDRVPROTO)
        return EINVAL;
    if (np->nd_if == NULL || np->nd_dlist_cnt == 0)
        return ENXIO;
    
    // Allocate storage
    MALLOC(multi_addr, struct sockaddr*, sopt->sopt_valsize,
            M_TEMP, M_WAITOK);
    if (multi_addr == NULL)
        return ENOMEM;
    
    // Copy in the address
    result = copyin(sopt->sopt_val, multi_addr, sopt->sopt_valsize);
    
    // Validate the sockaddr
    if (result == 0 && sopt->sopt_valsize != multi_addr->sa_len)
        result = EINVAL;
    
    if (result == 0)
    {
        /* Find the old entry */
        ndrv_entry = ndrv_have_multicast(np, multi_addr);
        
        if (ndrv_entry == NULL)
            result = ENOENT;
    }
    
    if (result == 0)
    {
        // Try deleting the multicast
        result = ifnet_remove_multicast(ndrv_entry->ifma);
    }
    
    if (result == 0)
    {
        // Remove from our linked list
        struct ndrv_multiaddr*  cur = np->nd_multiaddrs;
        
        ifmaddr_release(ndrv_entry->ifma);
        
        if (cur == ndrv_entry)
        {
            np->nd_multiaddrs = cur->next;
        }
        else
        {
            for (cur = cur->next; cur != NULL; cur = cur->next)
            {
                if (cur->next == ndrv_entry)
                {
                    cur->next = cur->next->next;
                    break;
                }
            }
        }
        
                np->nd_dlist_cnt--;
                
        // Free the memory
        FREE(ndrv_entry, M_IFADDR);
    }
    FREE(multi_addr, M_TEMP);
    
    return result;
}

static struct ndrv_multiaddr*
ndrv_have_multicast(struct ndrv_cb *np, struct sockaddr* inAddr)
{
    struct ndrv_multiaddr*      cur;
    for (cur = np->nd_multiaddrs; cur != NULL; cur = cur->next)
    {
        
        if ((inAddr->sa_len == cur->addr.sa_len) &&
            (bcmp(&cur->addr, inAddr, inAddr->sa_len) == 0))
        {
            // Found a match
            return cur;
        }
    }
    
    return NULL;
}

static void
ndrv_remove_all_multicast(struct ndrv_cb* np)
{
    struct ndrv_multiaddr*      cur;
    
    if (np->nd_if != NULL)
    {
        while (np->nd_multiaddrs != NULL)
        {
            cur = np->nd_multiaddrs;
            np->nd_multiaddrs = cur->next;
            
            ifnet_remove_multicast(cur->ifma);
            ifmaddr_release(cur->ifma);
            FREE(cur, M_IFADDR);
        }
    }
}

struct pr_usrreqs ndrv_usrreqs = {
        ndrv_abort, pru_accept_notsupp, ndrv_attach, ndrv_bind,
        ndrv_connect, pru_connect2_notsupp, pru_control_notsupp, ndrv_detach,
        ndrv_disconnect, pru_listen_notsupp, ndrv_peeraddr, pru_rcvd_notsupp,
        pru_rcvoob_notsupp, ndrv_send, pru_sense_null, ndrv_shutdown,
        ndrv_sockaddr, sosend, soreceive, pru_sopoll_notsupp
};

struct protosw ndrvsw =
{       SOCK_RAW, &ndrvdomain, NDRVPROTO_NDRV, PR_ATOMIC|PR_ADDR,
        NULL, ndrv_output, NULL, ndrv_ctloutput,
        NULL,
        NULL, NULL, NULL, NULL, NULL, 
        &ndrv_usrreqs,
        NULL, NULL, NULL,
        { NULL, NULL}, NULL,
        { 0 }
};

struct domain ndrvdomain =
{       AF_NDRV, 
        "NetDriver", 
        ndrv_dominit, 
        NULL, 
        NULL,
        NULL, 
        NULL, 
        NULL, 
        0, 
        0, 
        0, 
        0,
        NULL,
        0, 
        {0, 0}
};