src/netgraph.c - platform/external/libppp - Git at Google

 /*-
  * Copyright (c) 2000 Brian Somers <brian@Awfulhak.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  * $FreeBSD: src/usr.sbin/ppp/netgraph.c,v 1.6.10.1.4.1 2010/12/21 17:10:29 kensmith Exp $
  */

 #include <sys/param.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <netgraph.h>
 #include <net/ethernet.h>
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
 #include <netgraph/ng_ether.h>
 #include <netgraph/ng_message.h>
 #include <netgraph/ng_socket.h>

 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sysexits.h>
 #include <sys/fcntl.h>
 #include <sys/uio.h>
 #include <termios.h>
 #include <sys/time.h>
 #include <unistd.h>

 #include "layer.h"
 #include "defs.h"
 #include "mbuf.h"
 #include "log.h"
 #include "timer.h"
 #include "lqr.h"
 #include "hdlc.h"
 #include "throughput.h"
 #include "fsm.h"
 #include "lcp.h"
 #include "ccp.h"
 #include "link.h"
 #include "async.h"
 #include "descriptor.h"
 #include "physical.h"
 #include "main.h"
 #include "mp.h"
 #include "chat.h"
 #include "auth.h"
 #include "chap.h"
 #include "cbcp.h"
 #include "datalink.h"
 #include "slcompress.h"
 #include "iplist.h"
 #include "ncpaddr.h"
 #include "ipcp.h"
 #include "ipv6cp.h"
 #include "ncp.h"
 #include "filter.h"
 #ifndef NORADIUS
 #include "radius.h"
 #endif
 #include "bundle.h"
 #include "id.h"
 #include "netgraph.h"


 struct ngdevice {
   struct device dev;			/* What struct physical knows about */
   int cs;				/* Control socket */
   char hook[NG_HOOKSIZ];		/* Our socket node hook */
 };

 #define device2ng(d)	((d)->type == NG_DEVICE ? (struct ngdevice *)d : NULL)
 #define NG_MSGBUFSZ	4096
 #define NETGRAPH_PREFIX	"netgraph:"

 unsigned
 ng_DeviceSize(void)
 {
   return sizeof(struct ngdevice);
 }

 static int
 ng_MessageOut(struct ngdevice *dev, const char *data)
 {
   char path[NG_PATHSIZ];
   char *fmt;
   size_t len;
   int pos, dpos;

   /*
    * We expect a node path, one or more spaces, a command, one or more
    * spaces and an ascii netgraph structure.
    */
   data += strspn(data, " \t");
   len = strcspn(data, " \t");
   if (len >= sizeof path) {
     log_Printf(LogWARN, "%s: %.*s: Node path too long\n",
                  dev->dev.name, len, data);
     return 0;
   }
   memcpy(path, data, len);
   path[len] = '\0';
   data += len;

   data += strspn(data, " \t");
   len = strcspn(data, " \t");
   for (pos = len; pos >= 0; pos--)
     if (data[pos] == '%')
       len++;
   if ((fmt = alloca(len + 4)) == NULL) {
     log_Printf(LogWARN, "%s: alloca(%d) failure... %s\n",
                dev->dev.name, len + 4, strerror(errno));
     return 0;
   }

   /*
    * This is probably a waste of time, but we really don't want to end
    * up stuffing unexpected % escapes into the kernel....
    */
   for (pos = dpos = 0; pos < (int)len;) {
     if (data[dpos] == '%')
       fmt[pos++] = '%';
     fmt[pos++] = data[dpos++];
   }
   strcpy(fmt + pos, " %s");
   data += dpos;

   data += strspn(data, " \t");
   if (NgSendAsciiMsg(dev->cs, path, fmt, data) < 0) {
     log_Printf(LogDEBUG, "%s: NgSendAsciiMsg (to %s): \"%s\", \"%s\": %s\n",
                dev->dev.name, path, fmt, data, strerror(errno));
     return 0;
   }

   return 1;
 }

 /*
  * Get a netgraph message
  */
 static ssize_t
 ng_MessageIn(struct physical *p, char *buf, size_t sz)
 {
   char msgbuf[sizeof(struct ng_mesg) * 2 + NG_MSGBUFSZ];
   struct ngdevice *dev = device2ng(p->handler);
   struct ng_mesg *rep = (struct ng_mesg *)msgbuf;
   char path[NG_PATHSIZ];
   size_t len;

 #ifdef BROKEN_SELECT
   struct timeval t;
   fd_set *r;
   int ret;

   if (dev->cs < 0)
     return 0;

   if ((r = mkfdset()) == NULL) {
     log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
     return -1;
   }
   zerofdset(r);
   FD_SET(dev->cs, r);
   t.tv_sec = t.tv_usec = 0;
   ret = select(dev->cs + 1, r, NULL, NULL, &t);
   free(r);

   if (ret <= 0)
     return 0;
 #endif

   if (NgRecvAsciiMsg(dev->cs, rep, sizeof msgbuf, path)) {
     log_Printf(LogWARN, "%s: NgRecvAsciiMsg: %s\n",
                dev->dev.name, strerror(errno));
     return -1;
   }

   /* XXX: Should we check rep->header.version ? */

   if (sz == 0)
     log_Printf(LogWARN, "%s: Unexpected message: %s\n", dev->dev.name,
                rep->header.cmdstr);
   else {
     log_Printf(LogDEBUG, "%s: Received message: %s\n", dev->dev.name,
                rep->header.cmdstr);
     len = strlen(rep->header.cmdstr);
     if (sz > len)
       sz = len;
     memcpy(buf, rep->header.cmdstr, sz);
   }

   return sz;
 }

 static ssize_t
 ng_Write(struct physical *p, const void *v, size_t n)
 {
   struct ngdevice *dev = device2ng(p->handler);

   switch (p->dl->state) {
     case DATALINK_DIAL:
     case DATALINK_LOGIN:
       return ng_MessageOut(dev, v) ? (ssize_t)n : -1;
   }
   return NgSendData(p->fd, dev->hook, v, n) == -1 ? -1 : (ssize_t)n;
 }

 static ssize_t
 ng_Read(struct physical *p, void *v, size_t n)
 {
   char hook[NG_HOOKSIZ];

   switch (p->dl->state) {
     case DATALINK_DIAL:
     case DATALINK_LOGIN:
       return ng_MessageIn(p, v, n);
   }

   return NgRecvData(p->fd, v, n, hook);
 }

 static int
 ng_RemoveFromSet(struct physical *p, fd_set *r, fd_set *w, fd_set *e)
 {
   struct ngdevice *dev = device2ng(p->handler);
   int result;

   if (r && dev->cs >= 0 && FD_ISSET(dev->cs, r)) {
     FD_CLR(dev->cs, r);
     log_Printf(LogTIMER, "%s: fdunset(ctrl) %d\n", p->link.name, dev->cs);
     result = 1;
   } else
     result = 0;

   /* Careful... physical_RemoveFromSet() called us ! */

   p->handler->removefromset = NULL;
   result += physical_RemoveFromSet(p, r, w, e);
   p->handler->removefromset = ng_RemoveFromSet;

   return result;
 }

 static void
 ng_Free(struct physical *p)
 {
   struct ngdevice *dev = device2ng(p->handler);

   physical_SetDescriptor(p);
   if (dev->cs != -1)
     close(dev->cs);
   free(dev);
 }

 static void
 ng_device2iov(struct device *d, struct iovec *iov, int *niov,
               int maxiov __unused, int *auxfd, int *nauxfd)
 {
   struct ngdevice *dev;
   int sz = physical_MaxDeviceSize();

   iov[*niov].iov_base = d = realloc(d, sz);
   if (d == NULL) {
     log_Printf(LogALERT, "Failed to allocate memory: %d\n", sz);
     AbortProgram(EX_OSERR);
   }
   iov[*niov].iov_len = sz;
   (*niov)++;

   dev = device2ng(d);
   *auxfd = dev->cs;
   (*nauxfd)++;
 }

 static const struct device basengdevice = {
   NG_DEVICE,
   "netgraph",
   0,
   { CD_REQUIRED, DEF_NGCDDELAY },
   NULL,
   ng_RemoveFromSet,
   NULL,
   NULL,
   NULL,
   NULL,
   NULL,
   ng_Free,
   ng_Read,
   ng_Write,
   ng_device2iov,
   NULL,
   NULL,
   NULL
 };

 struct device *
 ng_iov2device(int type, struct physical *p, struct iovec *iov, int *niov,
               int maxiov __unused, int *auxfd, int *nauxfd)
 {
   if (type == NG_DEVICE) {
     struct ngdevice *dev = (struct ngdevice *)iov[(*niov)++].iov_base;

     dev = realloc(dev, sizeof *dev);	/* Reduce to the correct size */
     if (dev == NULL) {
       log_Printf(LogALERT, "Failed to allocate memory: %d\n",
                  (int)(sizeof *dev));
       AbortProgram(EX_OSERR);
     }

     if (*nauxfd) {
       dev->cs = *auxfd;
       (*nauxfd)--;
     } else
       dev->cs = -1;

     /* Refresh function pointers etc */
     memcpy(&dev->dev, &basengdevice, sizeof dev->dev);

     /* XXX: Are netgraph always synchronous ? */
     physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNCNOACF);
     return &dev->dev;
   }

   return NULL;
 }

 static int
 ng_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
 {
   struct physical *p = descriptor2physical(d);
   struct ngdevice *dev = device2ng(p->handler);
   int result;

   switch (p->dl->state) {
     case DATALINK_DIAL:
     case DATALINK_LOGIN:
       if (r) {
         FD_SET(dev->cs, r);
         log_Printf(LogTIMER, "%s(ctrl): fdset(r) %d\n", p->link.name, dev->cs);
         result = 1;
       } else
         result = 0;
       break;

     default:
       result = physical_doUpdateSet(d, r, w, e, n, 0);
       break;
   }

   return result;
 }

 static int
 ng_IsSet(struct fdescriptor *d, const fd_set *fdset)
 {
   struct physical *p = descriptor2physical(d);
   struct ngdevice *dev = device2ng(p->handler);
   int result;

   result = dev->cs >= 0 && FD_ISSET(dev->cs, fdset);
   result += physical_IsSet(d, fdset);

   return result;
 }

 static void
 ng_DescriptorRead(struct fdescriptor *d, struct bundle *bundle,
                   const fd_set *fdset)
 {
   struct physical *p = descriptor2physical(d);
   struct ngdevice *dev = device2ng(p->handler);

   if (dev->cs >= 0 && FD_ISSET(dev->cs, fdset))
     ng_MessageIn(p, NULL, 0);

   if (physical_IsSet(d, fdset))
     physical_DescriptorRead(d, bundle, fdset);
 }

 static struct device *
 ng_Abandon(struct ngdevice *dev, struct physical *p)
 {
   /* Abandon our node construction */
   close(dev->cs);
   close(p->fd);
   p->fd = -2;	/* Nobody else need try.. */
   free(dev);

   return NULL;
 }


 /*
  * Populate the ``word'' (of size ``sz'') named ``what'' from ``from''
  * ending with any character from ``sep''.  Point ``endp'' at the next
  * word.
  */

 #define GETSEGMENT(what, from, sep, endp) \
 	getsegment(#what, (what), sizeof(what), from, sep, endp)

 static int
 getsegment(const char *what, char *word, size_t sz, const char *from,
            const char *sep, const char **endp)
 {
   size_t len;

   if ((len = strcspn(from, sep)) == 0) {
     log_Printf(LogWARN, "%s name should not be empty !\n", what);
     return 0;
   }

   if (len >= sz) {
     log_Printf(LogWARN, "%s name too long, max %d !\n", what, sz - 1);
     return 0;
   }

   strncpy(word, from, len);
   word[len] = '\0';

   *endp = from + len;
   *endp += strspn(*endp, sep);

   return 1;
 }

 struct device *
 ng_Create(struct physical *p)
 {
   struct sockaddr_ng ngsock;
   u_char rbuf[2048];
   struct sockaddr *sock = (struct sockaddr *)&ngsock;
   const struct hooklist *hlist;
   const struct nodeinfo *ninfo;
   const struct linkinfo *nlink;
   struct ngdevice *dev;
   struct ng_mesg *resp;
   struct ngm_mkpeer mkp;
   struct ngm_connect ngc;
   const char *devp, *endp;
   char lasthook[NG_HOOKSIZ];
   char hook[NG_HOOKSIZ];
   char nodetype[NG_TYPESIZ + NG_NODESIZ];
   char modname[NG_TYPESIZ + 3];
   char path[NG_PATHSIZ];
   char *nodename;
   int len, sz, done;
   unsigned f;

   dev = NULL;
   if (p->fd < 0 && !strncasecmp(p->name.full, NETGRAPH_PREFIX,
                                 sizeof NETGRAPH_PREFIX - 1)) {
     p->fd--;				/* We own the device - change fd */

     if ((dev = malloc(sizeof *dev)) == NULL)
       return NULL;

     loadmodules(LOAD_VERBOSLY, "netgraph", "ng_socket", NULL);

     /* Create a socket node */
     if (ID0NgMkSockNode(NULL, &dev->cs, &p->fd) == -1) {
       log_Printf(LogWARN, "Cannot create netgraph socket node: %s\n",
                  strerror(errno));
       free(dev);
       p->fd = -2;
       return NULL;
     }

     devp = p->name.full + sizeof NETGRAPH_PREFIX - 1;
     *lasthook = *path = '\0';
     log_Printf(LogDEBUG, "%s: Opening netgraph device \"%s\"\n",
                p->link.name, devp);
     done = 0;

     while (*devp != '\0' && !done) {
       if (*devp != '[') {
         if (*lasthook == '\0') {
           log_Printf(LogWARN, "%s: Netgraph devices must start with"
                      " [nodetype:nodename]\n", p->link.name);
           return ng_Abandon(dev, p);
         }

         /* Get the hook name of the new node */
         if (!GETSEGMENT(hook, devp, ".[", &endp))
           return ng_Abandon(dev, p);
         log_Printf(LogDEBUG, "%s: Got hook \"%s\"\n", p->link.name, hook);
         devp = endp;
         if (*devp == '\0') {
           log_Printf(LogWARN, "%s: Netgraph device must not end with a second"
                      " hook\n", p->link.name);
           return ng_Abandon(dev, p);
         }
         if (devp[-1] != '[') {
           log_Printf(LogWARN, "%s: Expected a [nodetype:nodename] at device"
                      " pos %d\n", p->link.name, devp - p->link.name - 1);
           return ng_Abandon(dev, p);
         }
       } else {
         /* Use lasthook as the hook name */
         strcpy(hook, lasthook);
         devp++;
       }

       /* We've got ``lasthook'' and ``hook'', get the node type */
       if (!GETSEGMENT(nodetype, devp, "]", &endp))
         return ng_Abandon(dev, p);
       log_Printf(LogDEBUG, "%s: Got node \"%s\"\n", p->link.name, nodetype);

       if ((nodename = strchr(nodetype, ':')) != NULL) {
         *nodename++ = '\0';
         if (*nodename == '\0' && *nodetype == '\0') {
           log_Printf(LogWARN, "%s: Empty [nodetype:nodename] at device"
                      " pos %d\n", p->link.name, devp - p->link.name - 1);
           return ng_Abandon(dev, p);
         }
       }

       /* Ignore optional colons after nodes */
       devp = *endp == ':' ? endp + 1 : endp;
       if (*devp == '.')
         devp++;

       if (*lasthook == '\0') {
         /* This is the first node in the chain */
         if (nodename == NULL || *nodename == '\0') {
           log_Printf(LogWARN, "%s: %s: No initial device nodename\n",
                      p->link.name, devp);
           return ng_Abandon(dev, p);
         }

         if (*nodetype != '\0') {
           /* Attempt to load the module */
           snprintf(modname, sizeof modname, "ng_%s", nodetype);
           log_Printf(LogDEBUG, "%s: Attempting to load %s.ko\n",
                      p->link.name, modname);
           loadmodules(LOAD_QUIETLY, modname, NULL);
         }

         snprintf(path, sizeof path, "%s:", nodename);
         /* XXX: If we have a node type, ensure it's correct */
       } else {
         /*
          * Ask for a list of hooks attached to the previous node.  If we
          * find the one we're interested in, and if it's connected to a
          * node of the right type using the correct hook, use that.
          * If we find the hook connected to something else, fail.
          * If we find no match, mkpeer the new node.
          */
         if (*nodetype == '\0') {
           log_Printf(LogWARN, "%s: Nodetype missing at device offset %d\n",
                      p->link.name,
                      devp - p->name.full + sizeof NETGRAPH_PREFIX - 1);
           return ng_Abandon(dev, p);
         }

         /* Get a list of node hooks */
         if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE, NGM_LISTHOOKS,
                       NULL, 0) < 0) {
           log_Printf(LogWARN, "%s: %s Cannot send a LISTHOOOKS message: %s\n",
                      p->link.name, path, strerror(errno));
           return ng_Abandon(dev, p);
         }

         /* Get our list back */
         resp = (struct ng_mesg *)rbuf;
         if (NgRecvMsg(dev->cs, resp, sizeof rbuf, NULL) <= 0) {
           log_Printf(LogWARN, "%s: Cannot get netgraph response: %s\n",
                      p->link.name, strerror(errno));
           return ng_Abandon(dev, p);
         }

         hlist = (const struct hooklist *)resp->data;
         ninfo = &hlist->nodeinfo;

         log_Printf(LogDEBUG, "List of netgraph node ``%s'' (id %x) hooks:\n",
                    path, ninfo->id);

         /* look for a hook already attached.  */
         for (f = 0; f < ninfo->hooks; f++) {
           nlink = &hlist->link[f];

           log_Printf(LogDEBUG, "  Found %s -> %s (type %s)\n", nlink->ourhook,
                      nlink->peerhook, nlink->nodeinfo.type);

           if (!strcmp(nlink->ourhook, lasthook)) {
             if (strcmp(nlink->peerhook, hook) ||
                 strcmp(nlink->nodeinfo.type, nodetype)) {
               log_Printf(LogWARN, "%s: hook %s:%s is already in use\n",
                          p->link.name, nlink->ourhook, path);
               return ng_Abandon(dev, p);
             }
             /* The node is already hooked up nicely.... reuse it */
             break;
           }
         }

         if (f == ninfo->hooks) {
           /* Attempt to load the module */
           snprintf(modname, sizeof modname, "ng_%s", nodetype);
           log_Printf(LogDEBUG, "%s: Attempting to load %s.ko\n",
                      p->link.name, modname);
           loadmodules(LOAD_QUIETLY, modname, NULL);

           /* Create (mkpeer) the new node */

           snprintf(mkp.type, sizeof mkp.type, "%s", nodetype);
           snprintf(mkp.ourhook, sizeof mkp.ourhook, "%s", lasthook);
           snprintf(mkp.peerhook, sizeof mkp.peerhook, "%s", hook);

           log_Printf(LogDEBUG, "%s: Doing MKPEER %s%s -> %s (type %s)\n",
                      p->link.name, path, mkp.ourhook, mkp.peerhook, nodetype);

           if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE,
                         NGM_MKPEER, &mkp, sizeof mkp) < 0) {
             log_Printf(LogWARN, "%s Cannot create %s netgraph node: %s\n",
                        path, nodetype, strerror(errno));
             return ng_Abandon(dev, p);
           }
         }
         len = strlen(path);
         snprintf(path + len, sizeof path - len, "%s%s",
                  path[len - 1] == ':' ? "" : ".", lasthook);
       }

       /* Get a list of node hooks */
       if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE, NGM_LISTHOOKS,
                     NULL, 0) < 0) {
         log_Printf(LogWARN, "%s: %s Cannot send a LISTHOOOKS message: %s\n",
                    p->link.name, path, strerror(errno));
         return ng_Abandon(dev, p);
       }

       /* Get our list back */
       resp = (struct ng_mesg *)rbuf;
       if (NgRecvMsg(dev->cs, resp, sizeof rbuf, NULL) <= 0) {
         log_Printf(LogWARN, "%s: Cannot get netgraph response: %s\n",
                    p->link.name, strerror(errno));
         return ng_Abandon(dev, p);
       }

       hlist = (const struct hooklist *)resp->data;
       ninfo = &hlist->nodeinfo;

       if (*lasthook != '\0' && nodename != NULL && *nodename != '\0' &&
           strcmp(ninfo->name, nodename) &&
           NgNameNode(dev->cs, path, "%s", nodename) < 0) {
         log_Printf(LogWARN, "%s: %s: Cannot name netgraph node: %s\n",
                    p->link.name, path, strerror(errno));
         return ng_Abandon(dev, p);
       }

       if (!GETSEGMENT(lasthook, devp, " \t.[", &endp))
         return ng_Abandon(dev, p);
       log_Printf(LogDEBUG, "%s: Got hook \"%s\"\n", p->link.name, lasthook);

       len = strlen(lasthook);
       done = strchr(" \t", devp[len]) ? 1 : 0;
       devp = endp;

       if (*devp != '\0') {
         if (devp[-1] == '[')
           devp--;
       } /* else should moan about devp[-1] being '[' ? */
     }

     snprintf(dev->hook, sizeof dev->hook, "%s", lasthook);

     /* Connect the node to our socket node */
     snprintf(ngc.path, sizeof ngc.path, "%s", path);
     snprintf(ngc.ourhook, sizeof ngc.ourhook, "%s", dev->hook);
     memcpy(ngc.peerhook, ngc.ourhook, sizeof ngc.peerhook);

     log_Printf(LogDEBUG, "Connecting netgraph socket .:%s -> %s.%s\n",
                ngc.ourhook, ngc.path, ngc.peerhook);
     if (NgSendMsg(dev->cs, ".:", NGM_GENERIC_COOKIE,
                   NGM_CONNECT, &ngc, sizeof ngc) < 0) {
       log_Printf(LogWARN, "Cannot connect %s and socket netgraph "
                  "nodes: %s\n", path, strerror(errno));
       return ng_Abandon(dev, p);
     }

     /* Hook things up so that we monitor dev->cs */
     p->desc.UpdateSet = ng_UpdateSet;
     p->desc.IsSet = ng_IsSet;
     p->desc.Read = ng_DescriptorRead;

     memcpy(&dev->dev, &basengdevice, sizeof dev->dev);

   } else {
     /* See if we're a netgraph socket */

     sz = sizeof ngsock;
     if (getsockname(p->fd, sock, &sz) != -1 && sock->sa_family == AF_NETGRAPH) {
       /*
        * It's a netgraph node... We can't determine hook names etc, so we
        * stay pretty impartial....
        */
       log_Printf(LogPHASE, "%s: Link is a netgraph node\n", p->link.name);

       if ((dev = malloc(sizeof *dev)) == NULL) {
         log_Printf(LogWARN, "%s: Cannot allocate an ether device: %s\n",
                    p->link.name, strerror(errno));
         return NULL;
       }

       memcpy(&dev->dev, &basengdevice, sizeof dev->dev);
       dev->cs = -1;
       *dev->hook = '\0';
     }
   }

   if (dev) {
     physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNCNOACF);
     return &dev->dev;
   }

   return NULL;
 }
	/*-
	* Copyright (c) 2000 Brian Somers <brian@Awfulhak.org>
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*
	* $FreeBSD: src/usr.sbin/ppp/netgraph.c,v 1.6.10.1.4.1 2010/12/21 17:10:29 kensmith Exp $
	*/

	#include <sys/param.h>
	#include <sys/socket.h>
	#include <sys/un.h>
	#include <netinet/in.h>
	#include <arpa/inet.h>
	#include <netdb.h>
	#include <netgraph.h>
	#include <net/ethernet.h>
	#include <netinet/in_systm.h>
	#include <netinet/ip.h>
	#include <netgraph/ng_ether.h>
	#include <netgraph/ng_message.h>
	#include <netgraph/ng_socket.h>

	#include <errno.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sysexits.h>
	#include <sys/fcntl.h>
	#include <sys/uio.h>
	#include <termios.h>
	#include <sys/time.h>
	#include <unistd.h>

	#include "layer.h"
	#include "defs.h"
	#include "mbuf.h"
	#include "log.h"
	#include "timer.h"
	#include "lqr.h"
	#include "hdlc.h"
	#include "throughput.h"
	#include "fsm.h"
	#include "lcp.h"
	#include "ccp.h"
	#include "link.h"
	#include "async.h"
	#include "descriptor.h"
	#include "physical.h"
	#include "main.h"
	#include "mp.h"
	#include "chat.h"
	#include "auth.h"
	#include "chap.h"
	#include "cbcp.h"
	#include "datalink.h"
	#include "slcompress.h"
	#include "iplist.h"
	#include "ncpaddr.h"
	#include "ipcp.h"
	#include "ipv6cp.h"
	#include "ncp.h"
	#include "filter.h"
	#ifndef NORADIUS
	#include "radius.h"
	#endif
	#include "bundle.h"
	#include "id.h"
	#include "netgraph.h"


	struct ngdevice {
	struct device dev; /* What struct physical knows about */
	int cs; /* Control socket */
	char hook[NG_HOOKSIZ]; /* Our socket node hook */
	};

	#define device2ng(d) ((d)->type == NG_DEVICE ? (struct ngdevice *)d : NULL)
	#define NG_MSGBUFSZ 4096
	#define NETGRAPH_PREFIX "netgraph:"

	unsigned
	ng_DeviceSize(void)
	{
	return sizeof(struct ngdevice);
	}

	static int
	ng_MessageOut(struct ngdevice dev, const char data)
	{
	char path[NG_PATHSIZ];
	char *fmt;
	size_t len;
	int pos, dpos;

	/*
	* We expect a node path, one or more spaces, a command, one or more
	* spaces and an ascii netgraph structure.
	*/
	data += strspn(data, " \t");
	len = strcspn(data, " \t");
	if (len >= sizeof path) {
	log_Printf(LogWARN, "%s: %.*s: Node path too long\n",
	dev->dev.name, len, data);
	return 0;
	}
	memcpy(path, data, len);
	path[len] = '\0';
	data += len;

	data += strspn(data, " \t");
	len = strcspn(data, " \t");
	for (pos = len; pos >= 0; pos--)
	if (data[pos] == '%')
	len++;
	if ((fmt = alloca(len + 4)) == NULL) {
	log_Printf(LogWARN, "%s: alloca(%d) failure... %s\n",
	dev->dev.name, len + 4, strerror(errno));
	return 0;
	}

	/*
	* This is probably a waste of time, but we really don't want to end
	* up stuffing unexpected % escapes into the kernel....
	*/
	for (pos = dpos = 0; pos < (int)len;) {
	if (data[dpos] == '%')
	fmt[pos++] = '%';
	fmt[pos++] = data[dpos++];
	}
	strcpy(fmt + pos, " %s");
	data += dpos;

	data += strspn(data, " \t");
	if (NgSendAsciiMsg(dev->cs, path, fmt, data) < 0) {
	log_Printf(LogDEBUG, "%s: NgSendAsciiMsg (to %s): \"%s\", \"%s\": %s\n",
	dev->dev.name, path, fmt, data, strerror(errno));
	return 0;
	}

	return 1;
	}

	/*
	* Get a netgraph message
	*/
	static ssize_t
	ng_MessageIn(struct physical p, char buf, size_t sz)
	{
	char msgbuf[sizeof(struct ng_mesg) * 2 + NG_MSGBUFSZ];
	struct ngdevice *dev = device2ng(p->handler);
	struct ng_mesg rep = (struct ng_mesg )msgbuf;
	char path[NG_PATHSIZ];
	size_t len;

	#ifdef BROKEN_SELECT
	struct timeval t;
	fd_set *r;
	int ret;

	if (dev->cs < 0)
	return 0;

	if ((r = mkfdset()) == NULL) {
	log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
	return -1;
	}
	zerofdset(r);
	FD_SET(dev->cs, r);
	t.tv_sec = t.tv_usec = 0;
	ret = select(dev->cs + 1, r, NULL, NULL, &t);
	free(r);

	if (ret <= 0)
	return 0;
	#endif

	if (NgRecvAsciiMsg(dev->cs, rep, sizeof msgbuf, path)) {
	log_Printf(LogWARN, "%s: NgRecvAsciiMsg: %s\n",
	dev->dev.name, strerror(errno));
	return -1;
	}

	/* XXX: Should we check rep->header.version ? */

	if (sz == 0)
	log_Printf(LogWARN, "%s: Unexpected message: %s\n", dev->dev.name,
	rep->header.cmdstr);
	else {
	log_Printf(LogDEBUG, "%s: Received message: %s\n", dev->dev.name,
	rep->header.cmdstr);
	len = strlen(rep->header.cmdstr);
	if (sz > len)
	sz = len;
	memcpy(buf, rep->header.cmdstr, sz);
	}

	return sz;
	}

	static ssize_t
	ng_Write(struct physical p, const void v, size_t n)
	{
	struct ngdevice *dev = device2ng(p->handler);

	switch (p->dl->state) {
	case DATALINK_DIAL:
	case DATALINK_LOGIN:
	return ng_MessageOut(dev, v) ? (ssize_t)n : -1;
	}
	return NgSendData(p->fd, dev->hook, v, n) == -1 ? -1 : (ssize_t)n;
	}

	static ssize_t
	ng_Read(struct physical p, void v, size_t n)
	{
	char hook[NG_HOOKSIZ];

	switch (p->dl->state) {
	case DATALINK_DIAL:
	case DATALINK_LOGIN:
	return ng_MessageIn(p, v, n);
	}

	return NgRecvData(p->fd, v, n, hook);
	}

	static int
	ng_RemoveFromSet(struct physical p, fd_set r, fd_set w, fd_set e)
	{
	struct ngdevice *dev = device2ng(p->handler);
	int result;

	if (r && dev->cs >= 0 && FD_ISSET(dev->cs, r)) {
	FD_CLR(dev->cs, r);
	log_Printf(LogTIMER, "%s: fdunset(ctrl) %d\n", p->link.name, dev->cs);
	result = 1;
	} else
	result = 0;

	/* Careful... physical_RemoveFromSet() called us ! */

	p->handler->removefromset = NULL;
	result += physical_RemoveFromSet(p, r, w, e);
	p->handler->removefromset = ng_RemoveFromSet;

	return result;
	}

	static void
	ng_Free(struct physical *p)
	{
	struct ngdevice *dev = device2ng(p->handler);

	physical_SetDescriptor(p);
	if (dev->cs != -1)
	close(dev->cs);
	free(dev);
	}

	static void
	ng_device2iov(struct device d, struct iovec iov, int *niov,
	int maxiov __unused, int auxfd, int nauxfd)
	{
	struct ngdevice *dev;
	int sz = physical_MaxDeviceSize();

	iov[*niov].iov_base = d = realloc(d, sz);
	if (d == NULL) {
	log_Printf(LogALERT, "Failed to allocate memory: %d\n", sz);
	AbortProgram(EX_OSERR);
	}
	iov[*niov].iov_len = sz;
	(*niov)++;

	dev = device2ng(d);
	*auxfd = dev->cs;
	(*nauxfd)++;
	}

	static const struct device basengdevice = {
	NG_DEVICE,
	"netgraph",
	0,
	{ CD_REQUIRED, DEF_NGCDDELAY },
	NULL,
	ng_RemoveFromSet,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	ng_Free,
	ng_Read,
	ng_Write,
	ng_device2iov,
	NULL,
	NULL,
	NULL
	};

	struct device *
	ng_iov2device(int type, struct physical p, struct iovec iov, int *niov,
	int maxiov __unused, int auxfd, int nauxfd)
	{
	if (type == NG_DEVICE) {
	struct ngdevice dev = (struct ngdevice )iov[(*niov)++].iov_base;

	dev = realloc(dev, sizeof dev); / Reduce to the correct size */
	if (dev == NULL) {
	log_Printf(LogALERT, "Failed to allocate memory: %d\n",
	(int)(sizeof *dev));
	AbortProgram(EX_OSERR);
	}

	if (*nauxfd) {
	dev->cs = *auxfd;
	(*nauxfd)--;
	} else
	dev->cs = -1;

	/* Refresh function pointers etc */
	memcpy(&dev->dev, &basengdevice, sizeof dev->dev);

	/* XXX: Are netgraph always synchronous ? */
	physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNCNOACF);
	return &dev->dev;
	}

	return NULL;
	}

	static int
	ng_UpdateSet(struct fdescriptor d, fd_set r, fd_set w, fd_set e, int *n)
	{
	struct physical *p = descriptor2physical(d);
	struct ngdevice *dev = device2ng(p->handler);
	int result;

	switch (p->dl->state) {
	case DATALINK_DIAL:
	case DATALINK_LOGIN:
	if (r) {
	FD_SET(dev->cs, r);
	log_Printf(LogTIMER, "%s(ctrl): fdset(r) %d\n", p->link.name, dev->cs);
	result = 1;
	} else
	result = 0;
	break;

	default:
	result = physical_doUpdateSet(d, r, w, e, n, 0);
	break;
	}

	return result;
	}

	static int
	ng_IsSet(struct fdescriptor d, const fd_set fdset)
	{
	struct physical *p = descriptor2physical(d);
	struct ngdevice *dev = device2ng(p->handler);
	int result;

	result = dev->cs >= 0 && FD_ISSET(dev->cs, fdset);
	result += physical_IsSet(d, fdset);

	return result;
	}

	static void
	ng_DescriptorRead(struct fdescriptor d, struct bundle bundle,
	const fd_set *fdset)
	{
	struct physical *p = descriptor2physical(d);
	struct ngdevice *dev = device2ng(p->handler);

	if (dev->cs >= 0 && FD_ISSET(dev->cs, fdset))
	ng_MessageIn(p, NULL, 0);

	if (physical_IsSet(d, fdset))
	physical_DescriptorRead(d, bundle, fdset);
	}

	static struct device *
	ng_Abandon(struct ngdevice dev, struct physical p)
	{
	/* Abandon our node construction */
	close(dev->cs);
	close(p->fd);
	p->fd = -2; /* Nobody else need try.. */
	free(dev);

	return NULL;
	}


	/*
	* Populate the ``word'' (of size ``sz'') named ``what'' from ``from''
	* ending with any character from ``sep''. Point ``endp'' at the next
	* word.
	*/

	#define GETSEGMENT(what, from, sep, endp) \
	getsegment(#what, (what), sizeof(what), from, sep, endp)

	static int
	getsegment(const char what, char word, size_t sz, const char *from,
	const char sep, const char *endp)
	{
	size_t len;

	if ((len = strcspn(from, sep)) == 0) {
	log_Printf(LogWARN, "%s name should not be empty !\n", what);
	return 0;
	}

	if (len >= sz) {
	log_Printf(LogWARN, "%s name too long, max %d !\n", what, sz - 1);
	return 0;
	}

	strncpy(word, from, len);
	word[len] = '\0';

	*endp = from + len;
	endp += strspn(endp, sep);

	return 1;
	}

	struct device *
	ng_Create(struct physical *p)
	{
	struct sockaddr_ng ngsock;
	u_char rbuf[2048];
	struct sockaddr sock = (struct sockaddr )&ngsock;
	const struct hooklist *hlist;
	const struct nodeinfo *ninfo;
	const struct linkinfo *nlink;
	struct ngdevice *dev;
	struct ng_mesg *resp;
	struct ngm_mkpeer mkp;
	struct ngm_connect ngc;
	const char devp, endp;
	char lasthook[NG_HOOKSIZ];
	char hook[NG_HOOKSIZ];
	char nodetype[NG_TYPESIZ + NG_NODESIZ];
	char modname[NG_TYPESIZ + 3];
	char path[NG_PATHSIZ];
	char *nodename;
	int len, sz, done;
	unsigned f;

	dev = NULL;
	if (p->fd < 0 && !strncasecmp(p->name.full, NETGRAPH_PREFIX,
	sizeof NETGRAPH_PREFIX - 1)) {
	p->fd--; /* We own the device - change fd */

	if ((dev = malloc(sizeof *dev)) == NULL)
	return NULL;

	loadmodules(LOAD_VERBOSLY, "netgraph", "ng_socket", NULL);

	/* Create a socket node */
	if (ID0NgMkSockNode(NULL, &dev->cs, &p->fd) == -1) {
	log_Printf(LogWARN, "Cannot create netgraph socket node: %s\n",
	strerror(errno));
	free(dev);
	p->fd = -2;
	return NULL;
	}

	devp = p->name.full + sizeof NETGRAPH_PREFIX - 1;
	lasthook = path = '\0';
	log_Printf(LogDEBUG, "%s: Opening netgraph device \"%s\"\n",
	p->link.name, devp);
	done = 0;

	while (*devp != '\0' && !done) {
	if (*devp != '[') {
	if (*lasthook == '\0') {
	log_Printf(LogWARN, "%s: Netgraph devices must start with"
	" [nodetype:nodename]\n", p->link.name);
	return ng_Abandon(dev, p);
	}

	/* Get the hook name of the new node */
	if (!GETSEGMENT(hook, devp, ".[", &endp))
	return ng_Abandon(dev, p);
	log_Printf(LogDEBUG, "%s: Got hook \"%s\"\n", p->link.name, hook);
	devp = endp;
	if (*devp == '\0') {
	log_Printf(LogWARN, "%s: Netgraph device must not end with a second"
	" hook\n", p->link.name);
	return ng_Abandon(dev, p);
	}
	if (devp[-1] != '[') {
	log_Printf(LogWARN, "%s: Expected a [nodetype:nodename] at device"
	" pos %d\n", p->link.name, devp - p->link.name - 1);
	return ng_Abandon(dev, p);
	}
	} else {
	/* Use lasthook as the hook name */
	strcpy(hook, lasthook);
	devp++;
	}

	/* We've got ``lasthook'' and ``hook'', get the node type */
	if (!GETSEGMENT(nodetype, devp, "]", &endp))
	return ng_Abandon(dev, p);
	log_Printf(LogDEBUG, "%s: Got node \"%s\"\n", p->link.name, nodetype);

	if ((nodename = strchr(nodetype, ':')) != NULL) {
	*nodename++ = '\0';
	if (nodename == '\0' && nodetype == '\0') {
	log_Printf(LogWARN, "%s: Empty [nodetype:nodename] at device"
	" pos %d\n", p->link.name, devp - p->link.name - 1);
	return ng_Abandon(dev, p);
	}
	}

	/* Ignore optional colons after nodes */
	devp = *endp == ':' ? endp + 1 : endp;
	if (*devp == '.')
	devp++;

	if (*lasthook == '\0') {
	/* This is the first node in the chain */
	if (nodename == NULL \|\| *nodename == '\0') {
	log_Printf(LogWARN, "%s: %s: No initial device nodename\n",
	p->link.name, devp);
	return ng_Abandon(dev, p);
	}

	if (*nodetype != '\0') {
	/* Attempt to load the module */
	snprintf(modname, sizeof modname, "ng_%s", nodetype);
	log_Printf(LogDEBUG, "%s: Attempting to load %s.ko\n",
	p->link.name, modname);
	loadmodules(LOAD_QUIETLY, modname, NULL);
	}

	snprintf(path, sizeof path, "%s:", nodename);
	/* XXX: If we have a node type, ensure it's correct */
	} else {
	/*
	* Ask for a list of hooks attached to the previous node. If we
	* find the one we're interested in, and if it's connected to a
	* node of the right type using the correct hook, use that.
	* If we find the hook connected to something else, fail.
	* If we find no match, mkpeer the new node.
	*/
	if (*nodetype == '\0') {
	log_Printf(LogWARN, "%s: Nodetype missing at device offset %d\n",
	p->link.name,
	devp - p->name.full + sizeof NETGRAPH_PREFIX - 1);
	return ng_Abandon(dev, p);
	}

	/* Get a list of node hooks */
	if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE, NGM_LISTHOOKS,
	NULL, 0) < 0) {
	log_Printf(LogWARN, "%s: %s Cannot send a LISTHOOOKS message: %s\n",
	p->link.name, path, strerror(errno));
	return ng_Abandon(dev, p);
	}

	/* Get our list back */
	resp = (struct ng_mesg *)rbuf;
	if (NgRecvMsg(dev->cs, resp, sizeof rbuf, NULL) <= 0) {
	log_Printf(LogWARN, "%s: Cannot get netgraph response: %s\n",
	p->link.name, strerror(errno));
	return ng_Abandon(dev, p);
	}

	hlist = (const struct hooklist *)resp->data;
	ninfo = &hlist->nodeinfo;

	log_Printf(LogDEBUG, "List of netgraph node ``%s'' (id %x) hooks:\n",
	path, ninfo->id);

	/* look for a hook already attached. */
	for (f = 0; f < ninfo->hooks; f++) {
	nlink = &hlist->link[f];

	log_Printf(LogDEBUG, " Found %s -> %s (type %s)\n", nlink->ourhook,
	nlink->peerhook, nlink->nodeinfo.type);

	if (!strcmp(nlink->ourhook, lasthook)) {
	if (strcmp(nlink->peerhook, hook) \|\|
	strcmp(nlink->nodeinfo.type, nodetype)) {
	log_Printf(LogWARN, "%s: hook %s:%s is already in use\n",
	p->link.name, nlink->ourhook, path);
	return ng_Abandon(dev, p);
	}
	/* The node is already hooked up nicely.... reuse it */
	break;
	}
	}

	if (f == ninfo->hooks) {
	/* Attempt to load the module */
	snprintf(modname, sizeof modname, "ng_%s", nodetype);
	log_Printf(LogDEBUG, "%s: Attempting to load %s.ko\n",
	p->link.name, modname);
	loadmodules(LOAD_QUIETLY, modname, NULL);

	/* Create (mkpeer) the new node */

	snprintf(mkp.type, sizeof mkp.type, "%s", nodetype);
	snprintf(mkp.ourhook, sizeof mkp.ourhook, "%s", lasthook);
	snprintf(mkp.peerhook, sizeof mkp.peerhook, "%s", hook);

	log_Printf(LogDEBUG, "%s: Doing MKPEER %s%s -> %s (type %s)\n",
	p->link.name, path, mkp.ourhook, mkp.peerhook, nodetype);

	if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE,
	NGM_MKPEER, &mkp, sizeof mkp) < 0) {
	log_Printf(LogWARN, "%s Cannot create %s netgraph node: %s\n",
	path, nodetype, strerror(errno));
	return ng_Abandon(dev, p);
	}
	}
	len = strlen(path);
	snprintf(path + len, sizeof path - len, "%s%s",
	path[len - 1] == ':' ? "" : ".", lasthook);
	}

	/* Get a list of node hooks */
	if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE, NGM_LISTHOOKS,
	NULL, 0) < 0) {
	log_Printf(LogWARN, "%s: %s Cannot send a LISTHOOOKS message: %s\n",
	p->link.name, path, strerror(errno));
	return ng_Abandon(dev, p);
	}

	/* Get our list back */
	resp = (struct ng_mesg *)rbuf;
	if (NgRecvMsg(dev->cs, resp, sizeof rbuf, NULL) <= 0) {
	log_Printf(LogWARN, "%s: Cannot get netgraph response: %s\n",
	p->link.name, strerror(errno));
	return ng_Abandon(dev, p);
	}

	hlist = (const struct hooklist *)resp->data;
	ninfo = &hlist->nodeinfo;

	if (lasthook != '\0' && nodename != NULL && nodename != '\0' &&
	strcmp(ninfo->name, nodename) &&
	NgNameNode(dev->cs, path, "%s", nodename) < 0) {
	log_Printf(LogWARN, "%s: %s: Cannot name netgraph node: %s\n",
	p->link.name, path, strerror(errno));
	return ng_Abandon(dev, p);
	}

	if (!GETSEGMENT(lasthook, devp, " \t.[", &endp))
	return ng_Abandon(dev, p);
	log_Printf(LogDEBUG, "%s: Got hook \"%s\"\n", p->link.name, lasthook);

	len = strlen(lasthook);
	done = strchr(" \t", devp[len]) ? 1 : 0;
	devp = endp;

	if (*devp != '\0') {
	if (devp[-1] == '[')
	devp--;
	} /* else should moan about devp[-1] being '[' ? */
	}

	snprintf(dev->hook, sizeof dev->hook, "%s", lasthook);

	/* Connect the node to our socket node */
	snprintf(ngc.path, sizeof ngc.path, "%s", path);
	snprintf(ngc.ourhook, sizeof ngc.ourhook, "%s", dev->hook);
	memcpy(ngc.peerhook, ngc.ourhook, sizeof ngc.peerhook);

	log_Printf(LogDEBUG, "Connecting netgraph socket .:%s -> %s.%s\n",
	ngc.ourhook, ngc.path, ngc.peerhook);
	if (NgSendMsg(dev->cs, ".:", NGM_GENERIC_COOKIE,
	NGM_CONNECT, &ngc, sizeof ngc) < 0) {
	log_Printf(LogWARN, "Cannot connect %s and socket netgraph "
	"nodes: %s\n", path, strerror(errno));
	return ng_Abandon(dev, p);
	}

	/* Hook things up so that we monitor dev->cs */
	p->desc.UpdateSet = ng_UpdateSet;
	p->desc.IsSet = ng_IsSet;
	p->desc.Read = ng_DescriptorRead;

	memcpy(&dev->dev, &basengdevice, sizeof dev->dev);

	} else {
	/* See if we're a netgraph socket */

	sz = sizeof ngsock;
	if (getsockname(p->fd, sock, &sz) != -1 && sock->sa_family == AF_NETGRAPH) {
	/*
	* It's a netgraph node... We can't determine hook names etc, so we
	* stay pretty impartial....
	*/
	log_Printf(LogPHASE, "%s: Link is a netgraph node\n", p->link.name);

	if ((dev = malloc(sizeof *dev)) == NULL) {
	log_Printf(LogWARN, "%s: Cannot allocate an ether device: %s\n",
	p->link.name, strerror(errno));
	return NULL;
	}

	memcpy(&dev->dev, &basengdevice, sizeof dev->dev);
	dev->cs = -1;
	*dev->hook = '\0';
	}
	}

	if (dev) {
	physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNCNOACF);
	return &dev->dev;
	}

	return NULL;
	}