Turn on kernel link-detect

If interface has link-detect enabled, try and turn on link-detect
in the kernel.

6 files changed, 124 insertions, 3 deletions

diff --git a/configure.ac b/configure.ac
index 9f18bd39..e679632f 100755
--- a/configure.ac
+++ b/configure.ac
@@ -931,6 +931,12 @@ if test -r /proc/net/if_inet6; then
 fi
 AC_SUBST(IF_PROC)
 
+if test -r /proc/sys/net/ipv4/conf; then
+  AC_DEFINE(HAVE_PROC_NET_IPV4_CONF,,/proc/sys/net/ipv4/conf)
+  LINK_DETECT=if_linkdetect.o
+fi
+AC_SUBST(LINK_DETECT)
+
 dnl -----------------------------
 dnl check ipforward detect method
 dnl -----------------------------
diff --git a/zebra/Makefile.am b/zebra/Makefile.am
index 5d8db411..8977c893 100644
--- a/zebra/Makefile.am
+++ b/zebra/Makefile.am
@@ -10,13 +10,14 @@ LIBCAP = @LIBCAP@
 ipforward = @IPFORWARD@
 if_method = @IF_METHOD@
 if_proc = @IF_PROC@
+link_detect = @LINK_DETECT@
 rt_method = @RT_METHOD@
 rtread_method = @RTREAD_METHOD@
 kernel_method = @KERNEL_METHOD@
 other_method = @OTHER_METHOD@
 ioctl_method = @IOCTL_METHOD@
 
-otherobj = $(ioctl_method) $(ipforward) $(if_method) $(if_proc) \
+otherobj = $(ioctl_method) $(ipforward) $(if_method) $(if_proc) $(link_detect) \
 	$(rt_method) $(rtread_method) $(kernel_method) $(other_method)
 
 sbin_PROGRAMS = zebra
@@ -29,7 +30,7 @@ zebra_SOURCES = \
 	irdp_main.c irdp_interface.c irdp_packet.c router-id.c
 
 testzebra_SOURCES = test_main.c zebra_rib.c interface.c connected.c debug.c \
-	zebra_vty.c \
+	zebra_vty.c linkdetect_null.c \
 	kernel_null.c  redistribute_null.c ioctl_null.c misc_null.c
 
 noinst_HEADERS = \
@@ -42,7 +43,7 @@ testzebra_LDADD = $(LIBCAP) $(LIB_IPV6) ../lib/libzebra.la
 
 zebra_DEPENDENCIES = $(otherobj)
 
-EXTRA_DIST = if_ioctl.c if_ioctl_solaris.c if_netlink.c if_proc.c \
+EXTRA_DIST = if_ioctl.c if_ioctl_solaris.c  if_linkdetect.c if_netlink.c if_proc.c \
         if_sysctl.c ipforward_aix.c ipforward_ews.c ipforward_proc.c \
 	ipforward_solaris.c ipforward_sysctl.c rt_ioctl.c rt_netlink.c \
 	rt_socket.c rtread_netlink.c rtread_proc.c rtread_sysctl.c \
diff --git a/zebra/if_linkdetect.c b/zebra/if_linkdetect.c
new file mode 100644
index 00000000..9ae7c6a6
--- /dev/null
+++ b/zebra/if_linkdetect.c
@@ -0,0 +1,81 @@
+/* Interface link state tracking
+ * Copyright (C) 2008 Stephen Hemminger
+ *
+ * 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 "log.h"
+#include "privs.h"
+
+#include "log.h"
+#include "privs.h"
+#include "prefix.h"
+
+#include "zebra/interface.h"
+
+extern struct zebra_privs_t zserv_privs;
+
+static int
+linkdetect (const char *name, int onoff)
+{
+  FILE *fp;
+  int save_errno;
+  char proc_name[128];
+
+  snprintf(proc_name, sizeof(proc_name)-1, 
+	   "/proc/sys/net/ipv4/conf/%s/link_detect", name);
+  
+  if ( zserv_privs.change(ZPRIVS_RAISE) )
+    zlog_err ("Can't raise privileges, %s", safe_strerror (errno) );
+
+  fp = fopen (proc_name, "w");
+  save_errno = errno;
+  if (!fp)
+    {
+      if ( zserv_privs.change(ZPRIVS_LOWER) )
+	zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
+
+      zlog_info("Can't %s link-detect, %s:%s",
+		onoff ? "enable" : "disable",
+		proc_name, safe_strerror(save_errno));
+      return -1;
+    }
+  else
+    {
+      fprintf (fp, "%d\n", onoff);
+      fclose (fp);
+
+      if ( zserv_privs.change(ZPRIVS_LOWER) )
+	zlog_err ("Can't lower privileges, %s", safe_strerror (errno));
+
+      return onoff;
+    }
+}
+
+int
+if_linkdetect_on (const char *name)
+{
+  return linkdetect (name, 1);
+}
+
+int
+if_linkdetect_off (const char *name)
+{
+  return linkdetect (name, 1);
+}
diff --git a/zebra/interface.c b/zebra/interface.c
index cfcd5120..f6d2ff9b 100644
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -32,6 +32,7 @@
 #include "connected.h"
 #include "log.h"
 #include "zclient.h"
+#include "ipforward.h"
 
 #include "zebra/interface.h"
 #include "zebra/rtadv.h"
@@ -1029,6 +1030,9 @@ DEFUN (linkdetect,
   if_was_operative = if_is_operative(ifp);
   SET_FLAG(ifp->status, ZEBRA_INTERFACE_LINKDETECTION);
 
+  /* Enable FIB to remove kernel routes as well */
+  if_linkdetect_on(ifp->name);
+
   /* When linkdetection is enabled, if might come down */
   if (!if_is_operative(ifp) && if_was_operative) if_down(ifp);
 
@@ -1052,6 +1056,9 @@ DEFUN (no_linkdetect,
   if_was_operative = if_is_operative(ifp);
   UNSET_FLAG(ifp->status, ZEBRA_INTERFACE_LINKDETECTION);
   
+  /* Disable FIB update on link-detect */
+  if_linkdetect_off(ifp->name);
+
   /* Interface may come up after disabling link detection */
   if (if_is_operative(ifp) && !if_was_operative) if_up(ifp);
 
diff --git a/zebra/interface.h b/zebra/interface.h
index 0a6b0365..6f356686 100644
--- a/zebra/interface.h
+++ b/zebra/interface.h
@@ -234,6 +234,16 @@ extern int interface_list_proc (void);
 extern int ifaddr_proc_ipv6 (void);
 #endif /* HAVE_PROC_NET_IF_INET6 */
 
+#ifdef HAVE_PROC_NET_IPV4_CONF
+extern int if_linkdetect_on (const char *);
+extern int if_linkdetect_off (const char *);
+#else
+#error config
+#define if_linkdetect_on(name)
+#define if_linkdetect_off(name)
+#endif
+
+
 #ifdef BSDI
 extern int if_kvm_get_mtu (struct interface *);
 #endif /* BSDI */
diff --git a/zebra/linkdetect_null.c b/zebra/linkdetect_null.c
new file mode 100644
index 00000000..c33363e1
--- /dev/null
+++ b/zebra/linkdetect_null.c
@@ -0,0 +1,16 @@
+/* NULL method for testing. */
+
+#include <zebra.h>
+
+
+int
+if_linkdetect_on (const char *name)
+{
+  return 0;
+}
+
+int
+if_linkdetect_off (const char *name)
+{
+  return 0;
+}