Initial revision

1 files changed, 811 insertions, 0 deletions

diff --git a/zebra/kernel_socket.c b/zebra/kernel_socket.c
new file mode 100644
index 00000000..a47f4f63
--- /dev/null
+++ b/zebra/kernel_socket.c
@@ -0,0 +1,811 @@
+/* Kernel communication using routing socket.
+ * Copyright (C) 1999 Kunihiro Ishiguro
+ *
+ * This file is part of GNU Zebra.
+ *
+ * GNU Zebra is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * GNU Zebra is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Zebra; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.  
+ */
+
+#include <zebra.h>
+
+#include "if.h"
+#include "prefix.h"
+#include "sockunion.h"
+#include "connected.h"
+#include "memory.h"
+#include "ioctl.h"
+#include "log.h"
+#include "str.h"
+#include "table.h"
+#include "rib.h"
+
+#include "zebra/interface.h"
+#include "zebra/zserv.h"
+#include "zebra/debug.h"
+
+/* Socket length roundup function. */
+#define ROUNDUP(a) \
+  ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
+
+/* And this macro is wrapper for handling sa_len. */
+#ifdef HAVE_SA_LEN
+#define WRAPUP(X)   ROUNDUP(((struct sockaddr *)(X))->sa_len)
+#else
+#define WRAPUP(X)   ROUNDUP(sizeof (struct sockaddr))
+#endif /* HAVE_SA_LEN */
+
+/* Routing socket message types. */
+struct message rtm_type_str[] =
+{
+  {RTM_ADD,      "RTM_ADD"},
+  {RTM_DELETE,   "RTM_DELETE"},
+  {RTM_CHANGE,   "RTM_CHANGE"},
+  {RTM_GET,      "RTM_GET"},
+  {RTM_LOSING,   "RTM_LOSING"},
+  {RTM_REDIRECT, "RTM_REDIRECT"},
+  {RTM_MISS,     "RTM_MISS"},
+  {RTM_LOCK,     "RTM_LOCK"},
+  {RTM_OLDADD,   "RTM_OLDADD"},
+  {RTM_OLDDEL,   "RTM_OLDDEL"},
+  {RTM_RESOLVE,  "RTM_RESOLVE"},
+  {RTM_NEWADDR,  "RTM_NEWADDR"},
+  {RTM_DELADDR,  "RTM_DELADDR"},
+  {RTM_IFINFO,   "RTM_IFINFO"},
+#ifdef RTM_OIFINFO
+  {RTM_OIFINFO,   "RTM_OIFINFO"},
+#endif /* RTM_OIFINFO */
+#ifdef RTM_NEWMADDR
+  {RTM_NEWMADDR, "RTM_NEWMADDR"},
+#endif /* RTM_NEWMADDR */
+#ifdef RTM_DELMADDR
+  {RTM_DELMADDR, "RTM_DELMADDR"},
+#endif /* RTM_DELMADDR */
+#ifdef RTM_IFANNOUNCE
+  {RTM_IFANNOUNCE, "RTM_IFANNOUNCE"},
+#endif /* RTM_IFANNOUNCE */
+  {0,            NULL}
+};
+
+struct message rtm_flag_str[] =
+{
+  {RTF_UP,        "UP"},
+  {RTF_GATEWAY,   "GATEWAY"},
+  {RTF_HOST,      "HOST"},
+  {RTF_REJECT,    "REJECT"},
+  {RTF_DYNAMIC,   "DYNAMIC"},
+  {RTF_MODIFIED,  "MODIFIED"},
+  {RTF_DONE,      "DONE"},
+#ifdef RTF_MASK
+  {RTF_MASK,      "MASK"},
+#endif /* RTF_MASK */
+  {RTF_CLONING,   "CLONING"},
+  {RTF_XRESOLVE,  "XRESOLVE"},
+  {RTF_LLINFO,    "LLINFO"},
+  {RTF_STATIC,    "STATIC"},
+  {RTF_BLACKHOLE, "BLACKHOLE"},
+  {RTF_PROTO1,    "PROTO1"},
+  {RTF_PROTO2,    "PROTO2"},
+#ifdef RTF_PRCLONING
+  {RTF_PRCLONING, "PRCLONING"},
+#endif /* RTF_PRCLONING */
+#ifdef RTF_WASCLONED
+  {RTF_WASCLONED, "WASCLONED"},
+#endif /* RTF_WASCLONED */
+#ifdef RTF_PROTO3
+  {RTF_PROTO3,    "PROTO3"},
+#endif /* RTF_PROTO3 */
+#ifdef RTF_PINNED
+  {RTF_PINNED,    "PINNED"},
+#endif /* RTF_PINNED */
+#ifdef RTF_LOCAL
+  {RTF_LOCAL,    "LOCAL"},
+#endif /* RTF_LOCAL */
+#ifdef RTF_BROADCAST
+  {RTF_BROADCAST, "BROADCAST"},
+#endif /* RTF_BROADCAST */
+#ifdef RTF_MULTICAST
+  {RTF_MULTICAST, "MULTICAST"},
+#endif /* RTF_MULTICAST */
+  {0,             NULL}
+};
+
+/* Kernel routing update socket. */
+int routing_sock = -1;
+
+/* Yes I'm checking ugly routing socket behavior. */
+/* #define DEBUG */
+
+/* Supported address family check. */
+static int
+af_check (int family)
+{
+  if (family == AF_INET)
+    return 1;
+#ifdef HAVE_IPV6
+  if (family == AF_INET6)
+    return 1;
+#endif /* HAVE_IPV6 */
+  return 0;
+}
+
+/* Dump routing table flag for debug purpose. */
+void
+rtm_flag_dump (int flag)
+{
+  struct message *mes;
+  static char buf[BUFSIZ];
+
+  for (mes = rtm_flag_str; mes->key != 0; mes++)
+    {
+      if (mes->key & flag)
+	{
+	  strlcat (buf, mes->str, BUFSIZ);
+	  strlcat (buf, " ", BUFSIZ);
+	}
+    }
+  zlog_info ("Kernel: %s", buf);
+}
+
+#ifdef RTM_IFANNOUNCE
+/* Interface adding function */
+int
+ifan_read (struct if_announcemsghdr *ifan)
+{
+  struct interface *ifp;
+
+  ifp = if_lookup_by_index (ifan->ifan_index);
+  if (ifp == NULL && ifan->ifan_what == IFAN_ARRIVAL)
+    {
+      /* Create Interface */
+      ifp = if_get_by_name (ifan->ifan_name);
+      ifp->ifindex = ifan->ifan_index;
+
+      if_add_update (ifp);
+    }
+  else if (ifp != NULL && ifan->ifan_what == IFAN_DEPARTURE)
+    {
+      if_delete_update (ifp);
+      if_delete (ifp);
+    }
+
+  if_get_flags (ifp);
+  if_get_mtu (ifp);
+  if_get_metric (ifp);
+
+  if (IS_ZEBRA_DEBUG_KERNEL)
+    zlog_info ("interface %s index %d", ifp->name, ifp->ifindex);
+
+  return 0;
+}
+#endif /* RTM_IFANNOUNCE */
+
+/* Interface adding function called from interface_list. */
+int
+ifm_read (struct if_msghdr *ifm)
+{
+  struct interface *ifp;
+  struct sockaddr_dl *sdl = NULL;
+
+  sdl = (struct sockaddr_dl *)(ifm + 1);
+
+  /* Use sdl index. */
+  ifp = if_lookup_by_index (ifm->ifm_index);
+
+  if (ifp == NULL)
+    {
+      /* Check interface's address.*/
+      if (! (ifm->ifm_addrs & RTA_IFP))
+	{
+	  zlog_warn ("There must be RTA_IFP address for ifindex %d\n",
+		     ifm->ifm_index);
+	  return -1;
+	}
+
+      ifp = if_create ();
+
+      strncpy (ifp->name, sdl->sdl_data, sdl->sdl_nlen);
+      ifp->ifindex = ifm->ifm_index;
+      ifp->flags = ifm->ifm_flags;
+#if defined(__bsdi__)
+      if_kvm_get_mtu (ifp);
+#else
+      if_get_mtu (ifp);
+#endif /* __bsdi__ */
+      if_get_metric (ifp);
+
+      /* Fetch hardware address. */
+      if (sdl->sdl_family != AF_LINK)
+	{
+	  zlog_warn ("sockaddr_dl->sdl_family is not AF_LINK");
+	  return -1;
+	}
+      memcpy (&ifp->sdl, sdl, sizeof (struct sockaddr_dl));
+
+      if_add_update (ifp);
+    }
+  else
+    {
+      /* There is a case of promisc, allmulti flag modification. */
+      if (if_is_up (ifp))
+	{
+	  ifp->flags = ifm->ifm_flags;
+	  if (! if_is_up (ifp))
+	    if_down (ifp);
+	}
+      else
+	{
+	  ifp->flags = ifm->ifm_flags;
+	  if (if_is_up (ifp))
+	    if_up (ifp);
+	}
+    }
+  
+#ifdef HAVE_NET_RT_IFLIST
+  ifp->stats = ifm->ifm_data;
+#endif /* HAVE_NET_RT_IFLIST */
+
+  if (IS_ZEBRA_DEBUG_KERNEL)
+    zlog_info ("interface %s index %d", ifp->name, ifp->ifindex);
+
+  return 0;
+}
+
+/* Address read from struct ifa_msghdr. */
+void
+ifam_read_mesg (struct ifa_msghdr *ifm,
+		union sockunion *addr,
+		union sockunion *mask,
+		union sockunion *dest)
+{
+  caddr_t pnt, end;
+
+  pnt = (caddr_t)(ifm + 1);
+  end = ((caddr_t)ifm) + ifm->ifam_msglen;
+
+#define IFAMADDRGET(X,R) \
+    if (ifm->ifam_addrs & (R)) \
+      { \
+        int len = WRAPUP(pnt); \
+        if (((X) != NULL) && af_check (((struct sockaddr *)pnt)->sa_family)) \
+          memcpy ((caddr_t)(X), pnt, len); \
+        pnt += len; \
+      }
+#define IFAMMASKGET(X,R) \
+    if (ifm->ifam_addrs & (R)) \
+      { \
+	int len = WRAPUP(pnt); \
+        if ((X) != NULL) \
+	  memcpy ((caddr_t)(X), pnt, len); \
+	pnt += len; \
+      }
+
+  /* Be sure structure is cleared */
+  memset (mask, 0, sizeof (union sockunion));
+  memset (addr, 0, sizeof (union sockunion));
+  memset (dest, 0, sizeof (union sockunion));
+
+  /* We fetch each socket variable into sockunion. */
+  IFAMADDRGET (NULL, RTA_DST);
+  IFAMADDRGET (NULL, RTA_GATEWAY);
+  IFAMMASKGET (mask, RTA_NETMASK);
+  IFAMADDRGET (NULL, RTA_GENMASK);
+  IFAMADDRGET (NULL, RTA_IFP);
+  IFAMADDRGET (addr, RTA_IFA);
+  IFAMADDRGET (NULL, RTA_AUTHOR);
+  IFAMADDRGET (dest, RTA_BRD);
+
+  /* Assert read up end point matches to end point */
+  if (pnt != end)
+    zlog_warn ("ifam_read() does't read all socket data");
+}
+
+/* Interface's address information get. */
+int
+ifam_read (struct ifa_msghdr *ifam)
+{
+  struct interface *ifp;
+  union sockunion addr, mask, gate;
+
+  /* Check does this interface exist or not. */
+  ifp = if_lookup_by_index (ifam->ifam_index);
+  if (ifp == NULL) 
+    {
+      zlog_warn ("no interface for index %d", ifam->ifam_index); 
+      return -1;
+    }
+
+  /* Allocate and read address information. */
+  ifam_read_mesg (ifam, &addr, &mask, &gate);
+
+  /* Check interface flag for implicit up of the interface. */
+  if_refresh (ifp);
+
+  /* Add connected address. */
+  switch (sockunion_family (&addr))
+    {
+    case AF_INET:
+      if (ifam->ifam_type == RTM_NEWADDR)
+	connected_add_ipv4 (ifp, 0, &addr.sin.sin_addr, 
+			    ip_masklen (mask.sin.sin_addr),
+			    &gate.sin.sin_addr, NULL);
+      else
+	connected_delete_ipv4 (ifp, 0, &addr.sin.sin_addr, 
+			       ip_masklen (mask.sin.sin_addr),
+			       &gate.sin.sin_addr, NULL);
+      break;
+#ifdef HAVE_IPV6
+    case AF_INET6:
+      /* Unset interface index from link-local address when IPv6 stack
+	 is KAME. */
+      if (IN6_IS_ADDR_LINKLOCAL (&addr.sin6.sin6_addr))
+	SET_IN6_LINKLOCAL_IFINDEX (addr.sin6.sin6_addr, 0);
+
+      if (ifam->ifam_type == RTM_NEWADDR)
+	connected_add_ipv6 (ifp,
+			    &addr.sin6.sin6_addr, 
+			    ip6_masklen (mask.sin6.sin6_addr),
+			    &gate.sin6.sin6_addr);
+      else
+	connected_delete_ipv6 (ifp,
+			       &addr.sin6.sin6_addr, 
+			       ip6_masklen (mask.sin6.sin6_addr),
+			       &gate.sin6.sin6_addr);
+      break;
+#endif /* HAVE_IPV6 */
+    default:
+      /* Unsupported family silently ignore... */
+      break;
+    }
+  return 0;
+}
+
+/* Interface function for reading kernel routing table information. */
+int
+rtm_read_mesg (struct rt_msghdr *rtm,
+	       union sockunion *dest,
+	       union sockunion *mask,
+	       union sockunion *gate)
+{
+  caddr_t pnt, end;
+
+  /* Pnt points out socket data start point. */
+  pnt = (caddr_t)(rtm + 1);
+  end = ((caddr_t)rtm) + rtm->rtm_msglen;
+
+  /* rt_msghdr version check. */
+  if (rtm->rtm_version != RTM_VERSION) 
+      zlog (NULL, LOG_WARNING,
+	      "Routing message version different %d should be %d."
+	      "This may cause problem\n", rtm->rtm_version, RTM_VERSION);
+
+#define RTMADDRGET(X,R) \
+    if (rtm->rtm_addrs & (R)) \
+      { \
+	int len = WRAPUP (pnt); \
+        if (((X) != NULL) && af_check (((struct sockaddr *)pnt)->sa_family)) \
+	  memcpy ((caddr_t)(X), pnt, len); \
+	pnt += len; \
+      }
+#define RTMMASKGET(X,R) \
+    if (rtm->rtm_addrs & (R)) \
+      { \
+	int len = WRAPUP (pnt); \
+        if ((X) != NULL) \
+	  memcpy ((caddr_t)(X), pnt, len); \
+	pnt += len; \
+      }
+
+  /* Be sure structure is cleared */
+  memset (dest, 0, sizeof (union sockunion));
+  memset (gate, 0, sizeof (union sockunion));
+  memset (mask, 0, sizeof (union sockunion));
+
+  /* We fetch each socket variable into sockunion. */
+  RTMADDRGET (dest, RTA_DST);
+  RTMADDRGET (gate, RTA_GATEWAY);
+  RTMMASKGET (mask, RTA_NETMASK);
+  RTMADDRGET (NULL, RTA_GENMASK);
+  RTMADDRGET (NULL, RTA_IFP);
+  RTMADDRGET (NULL, RTA_IFA);
+  RTMADDRGET (NULL, RTA_AUTHOR);
+  RTMADDRGET (NULL, RTA_BRD);
+
+  /* If there is netmask information set it's family same as
+     destination family*/
+  if (rtm->rtm_addrs & RTA_NETMASK)
+    mask->sa.sa_family = dest->sa.sa_family;
+
+  /* Assert read up to the end of pointer. */
+  if (pnt != end) 
+      zlog (NULL, LOG_WARNING, "rtm_read() does't read all socket data.");
+
+  return rtm->rtm_flags;
+}
+
+void
+rtm_read (struct rt_msghdr *rtm)
+{
+  int flags;
+  u_char zebra_flags;
+  union sockunion dest, mask, gate;
+
+  zebra_flags = 0;
+
+  /* Discard self send message. */
+  if (rtm->rtm_type != RTM_GET 
+      && (rtm->rtm_pid == pid || rtm->rtm_pid == old_pid))
+    return;
+
+  /* Read destination and netmask and gateway from rtm message
+     structure. */
+  flags = rtm_read_mesg (rtm, &dest, &mask, &gate);
+
+#ifdef RTF_CLONED	/*bsdi, netbsd 1.6*/
+  if (flags & RTF_CLONED)
+    return;
+#endif
+#ifdef RTF_WASCLONED	/*freebsd*/
+  if (flags & RTF_WASCLONED)
+    return;
+#endif
+
+  if ((rtm->rtm_type == RTM_ADD) && ! (flags & RTF_UP))
+    return;
+
+  /* This is connected route. */
+  if (! (flags & RTF_GATEWAY))
+      return;
+
+  if (flags & RTF_PROTO1)
+    SET_FLAG (zebra_flags, ZEBRA_FLAG_SELFROUTE);
+
+  /* This is persistent route. */
+  if (flags & RTF_STATIC)
+    SET_FLAG (zebra_flags, ZEBRA_FLAG_STATIC);
+
+  if (dest.sa.sa_family == AF_INET)
+    {
+      struct prefix_ipv4 p;
+
+      p.family = AF_INET;
+      p.prefix = dest.sin.sin_addr;
+      if (flags & RTF_HOST)
+	p.prefixlen = IPV4_MAX_PREFIXLEN;
+      else
+	p.prefixlen = ip_masklen (mask.sin.sin_addr);
+
+      if (rtm->rtm_type == RTM_GET || rtm->rtm_type == RTM_ADD)
+	rib_add_ipv4 (ZEBRA_ROUTE_KERNEL, zebra_flags, 
+		      &p, &gate.sin.sin_addr, 0, 0, 0, 0);
+      else
+	rib_delete_ipv4 (ZEBRA_ROUTE_KERNEL, zebra_flags, 
+		      &p, &gate.sin.sin_addr, 0, 0);
+    }
+#ifdef HAVE_IPV6
+  if (dest.sa.sa_family == AF_INET6)
+    {
+      struct prefix_ipv6 p;
+      unsigned int ifindex = 0;
+
+      p.family = AF_INET6;
+      p.prefix = dest.sin6.sin6_addr;
+      if (flags & RTF_HOST)
+	p.prefixlen = IPV6_MAX_PREFIXLEN;
+      else
+	p.prefixlen = ip6_masklen (mask.sin6.sin6_addr);
+
+#ifdef KAME
+      if (IN6_IS_ADDR_LINKLOCAL (&gate.sin6.sin6_addr))
+	{
+	  ifindex = IN6_LINKLOCAL_IFINDEX (gate.sin6.sin6_addr);
+	  SET_IN6_LINKLOCAL_IFINDEX (gate.sin6.sin6_addr, 0);
+	}
+#endif /* KAME */
+
+      if (rtm->rtm_type == RTM_GET || rtm->rtm_type == RTM_ADD)
+	rib_add_ipv6 (ZEBRA_ROUTE_KERNEL, zebra_flags,
+		      &p, &gate.sin6.sin6_addr, ifindex, 0);
+      else
+	rib_delete_ipv6 (ZEBRA_ROUTE_KERNEL, zebra_flags,
+			 &p, &gate.sin6.sin6_addr, ifindex, 0);
+    }
+#endif /* HAVE_IPV6 */
+}
+
+/* Interface function for the kernel routing table updates.  Support
+   for RTM_CHANGE will be needed. */
+int
+rtm_write (int message,
+	   union sockunion *dest,
+	   union sockunion *mask,
+	   union sockunion *gate,
+	   unsigned int index,
+	   int zebra_flags,
+	   int metric)
+{
+  int ret;
+  caddr_t pnt;
+  struct interface *ifp;
+  struct sockaddr_in tmp_gate;
+#ifdef HAVE_IPV6
+  struct sockaddr_in6 tmp_gate6;
+#endif /* HAVE_IPV6 */
+
+  /* Sequencial number of routing message. */
+  static int msg_seq = 0;
+
+  /* Struct of rt_msghdr and buffer for storing socket's data. */
+  struct 
+  {
+    struct rt_msghdr rtm;
+    char buf[512];
+  } msg;
+  
+  memset (&tmp_gate, 0, sizeof (struct sockaddr_in));
+  tmp_gate.sin_family = AF_INET;
+#ifdef HAVE_SIN_LEN
+  tmp_gate.sin_len = sizeof (struct sockaddr_in);
+#endif /* HAVE_SIN_LEN */
+
+#ifdef HAVE_IPV6
+  memset (&tmp_gate6, 0, sizeof (struct sockaddr_in6));
+  tmp_gate6.sin6_family = AF_INET6;
+#ifdef SIN6_LEN
+  tmp_gate6.sin6_len = sizeof (struct sockaddr_in6);
+#endif /* SIN6_LEN */
+#endif /* HAVE_IPV6 */
+
+  if (routing_sock < 0)
+    return ZEBRA_ERR_EPERM;
+
+  /* Clear and set rt_msghdr values */
+  memset (&msg, 0, sizeof (struct rt_msghdr));
+  msg.rtm.rtm_version = RTM_VERSION;
+  msg.rtm.rtm_type = message;
+  msg.rtm.rtm_seq = msg_seq++;
+  msg.rtm.rtm_addrs = RTA_DST;
+  msg.rtm.rtm_addrs |= RTA_GATEWAY;
+  msg.rtm.rtm_flags = RTF_UP;
+  msg.rtm.rtm_index = index;
+
+  if (metric != 0)
+    {
+      msg.rtm.rtm_rmx.rmx_hopcount = metric;
+      msg.rtm.rtm_inits |= RTV_HOPCOUNT;
+    }
+
+  ifp = if_lookup_by_index (index);
+
+  if (gate && message == RTM_ADD)
+    msg.rtm.rtm_flags |= RTF_GATEWAY;
+
+  if (! gate && message == RTM_ADD && ifp &&
+      (ifp->flags & IFF_POINTOPOINT) == 0)
+    msg.rtm.rtm_flags |= RTF_CLONING;
+
+  /* If no protocol specific gateway is specified, use link
+     address for gateway. */
+  if (! gate)
+    {
+      if (!ifp)
+        {
+          zlog_warn ("no gateway found for interface index %d", index);
+          return -1;
+        }
+      gate = (union sockunion *) & ifp->sdl;
+    }
+
+  if (mask)
+    msg.rtm.rtm_addrs |= RTA_NETMASK;
+  else if (message == RTM_ADD) 
+    msg.rtm.rtm_flags |= RTF_HOST;
+
+  /* Tagging route with flags */
+  msg.rtm.rtm_flags |= (RTF_PROTO1);
+
+  /* Additional flags. */
+  if (zebra_flags & ZEBRA_FLAG_BLACKHOLE)
+    msg.rtm.rtm_flags |= RTF_BLACKHOLE;
+
+#ifdef HAVE_SIN_LEN
+#define SOCKADDRSET(X,R) \
+  if (msg.rtm.rtm_addrs & (R)) \
+    { \
+      int len = ROUNDUP ((X)->sa.sa_len); \
+      memcpy (pnt, (caddr_t)(X), len); \
+      pnt += len; \
+    }
+#else 
+#define SOCKADDRSET(X,R) \
+  if (msg.rtm.rtm_addrs & (R)) \
+    { \
+      int len = ROUNDUP (sizeof((X)->sa)); \
+      memcpy (pnt, (caddr_t)(X), len); \
+      pnt += len; \
+    }
+#endif /* HAVE_SIN_LEN */
+
+  pnt = (caddr_t) msg.buf;
+
+  /* Write each socket data into rtm message buffer */
+  SOCKADDRSET (dest, RTA_DST);
+  SOCKADDRSET (gate, RTA_GATEWAY);
+  SOCKADDRSET (mask, RTA_NETMASK);
+
+  msg.rtm.rtm_msglen = pnt - (caddr_t) &msg;
+
+  ret = write (routing_sock, &msg, msg.rtm.rtm_msglen);
+
+  if (ret != msg.rtm.rtm_msglen) 
+    {
+      if (errno == EEXIST) 
+	return ZEBRA_ERR_RTEXIST;
+      if (errno == ENETUNREACH)
+	return ZEBRA_ERR_RTUNREACH;
+      
+      zlog_warn ("write : %s (%d)", strerror (errno), errno);
+      return -1;
+    }
+  return 0;
+}
+
+
+#include "thread.h"
+#include "zebra/zserv.h"
+
+extern struct thread_master *master;
+
+/* For debug purpose. */
+void
+rtmsg_debug (struct rt_msghdr *rtm)
+{
+  char *type = "Unknown";
+  struct message *mes;
+
+  for (mes = rtm_type_str; mes->str; mes++)
+    if (mes->key == rtm->rtm_type)
+      {
+	type = mes->str;
+	break;
+      }
+
+  zlog_info ("Kernel: Len: %d Type: %s", rtm->rtm_msglen, type);
+  rtm_flag_dump (rtm->rtm_flags);
+  zlog_info ("Kernel: message seq %d", rtm->rtm_seq);
+  zlog_info ("Kernel: pid %d", rtm->rtm_pid);
+}
+
+/* This is pretty gross, better suggestions welcome -- mhandler */
+#ifndef RTAX_MAX
+#ifdef RTA_NUMBITS
+#define RTAX_MAX	RTA_NUMBITS
+#else
+#define RTAX_MAX	8
+#endif /* RTA_NUMBITS */
+#endif /* RTAX_MAX */
+
+/* Kernel routing table and interface updates via routing socket. */
+int
+kernel_read (struct thread *thread)
+{
+  int sock;
+  int nbytes;
+  struct rt_msghdr *rtm;
+
+  union 
+  {
+    /* Routing information. */
+    struct 
+    {
+      struct rt_msghdr rtm;
+      struct sockaddr addr[RTAX_MAX];
+    } r;
+
+    /* Interface information. */
+    struct
+    {
+      struct if_msghdr ifm;
+      struct sockaddr addr[RTAX_MAX];
+    } im;
+
+    /* Interface address information. */
+    struct
+    {
+      struct ifa_msghdr ifa;
+      struct sockaddr addr[RTAX_MAX];
+    } ia;
+
+#ifdef RTM_IFANNOUNCE
+    /* Interface arrival/departure */
+    struct
+    {
+      struct if_announcemsghdr ifan;
+      struct sockaddr addr[RTAX_MAX];
+    } ian;
+#endif /* RTM_IFANNOUNCE */
+
+  } buf;
+
+  /* Fetch routing socket. */
+  sock = THREAD_FD (thread);
+
+  nbytes= read (sock, &buf, sizeof buf);
+
+  if (nbytes <= 0)
+    {
+      if (nbytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN)
+	zlog_warn ("routing socket error: %s", strerror (errno));
+      return 0;
+    }
+
+  thread_add_read (master, kernel_read, NULL, sock);
+
+#ifdef DEBUG
+  rtmsg_debug (&buf.r.rtm);
+#endif /* DEBUG */
+
+  rtm = &buf.r.rtm;
+
+  switch (rtm->rtm_type)
+    {
+    case RTM_ADD:
+    case RTM_DELETE:
+      rtm_read (rtm);
+      break;
+    case RTM_IFINFO:
+      ifm_read (&buf.im.ifm);
+      break;
+    case RTM_NEWADDR:
+    case RTM_DELADDR:
+      ifam_read (&buf.ia.ifa);
+      break;
+#ifdef RTM_IFANNOUNCE
+    case RTM_IFANNOUNCE:
+      ifan_read (&buf.ian.ifan);
+      break;
+#endif /* RTM_IFANNOUNCE */
+    default:
+      break;
+    }
+  return 0;
+}
+
+/* Make routing socket. */
+void
+routing_socket ()
+{
+  routing_sock = socket (AF_ROUTE, SOCK_RAW, 0);
+
+  if (routing_sock < 0) 
+    {
+      zlog_warn ("Can't init kernel routing socket");
+      return;
+    }
+
+  if (fcntl (routing_sock, F_SETFL, O_NONBLOCK) < 0) 
+    zlog_warn ("Can't set O_NONBLOCK to routing socket");
+
+  /* kernel_read needs rewrite. */
+  thread_add_read (master, kernel_read, NULL, routing_sock);
+}
+
+/* Exported interface function.  This function simply calls
+   routing_socket (). */
+void
+kernel_init ()
+{
+  routing_socket ();
+}