Use constants from /etc/iproute2/rt_* files.

configure.in

@@ -13,6 +13,7 @@ AC_ARG_ENABLE(ipv6,[  --enable-ipv6           enable building of IPv6 version (d
 AC_ARG_WITH(sysconfig,[  --with-sysconfig=FILE   use specified BIRD system configuration file])
 AC_ARG_WITH(protocols,[  --with-protocols=LIST   include specified routing protocols (default: all)],,[with_protocols="all"])
 AC_ARG_WITH(sysinclude,[  --with-sysinclude=PATH  search for system includes on specified place])
+AC_ARG_WITH(iproutedir,[  --with-iproutedir=PATH  path to iproute2 config files (default: /etc/iproute2)],[given_iproutedir="yes"])
 AC_ARG_VAR([FLEX], [location of the Flex program]) 
 AC_ARG_VAR([BISON], [location of the Bison program]) 
 AC_ARG_VAR([M4], [location of the M4 program]) 
@@ -105,12 +106,14 @@ elif test -f sysconfig.h ; then
 else
 	case "$ip:$host_os" in
 		ipv4:linux*)	BIRD_CHECK_LINUX_VERSION
+				default_iproutedir="/etc/iproute2"
 				case $bird_cv_sys_linux_version in
 					1.*|2.0.*)	sysdesc=linux-20 ;;
 					*)		sysdesc=linux-22 ;;
 					esac
 				;;
 		ipv6:linux*)	BIRD_CHECK_LINUX_VERSION
+				default_iproutedir="/etc/iproute2"
 				case $bird_cv_sys_linux_version in
 					1.*|2.0.*)	AC_MSG_ERROR([This version of Linux doesn't support IPv6.]) ;;
 					*)		sysdesc=linux-v6 ;;
@@ -154,6 +157,15 @@ sysdep_dirs="`sed <$sysdesc '/^Link: /!d;s/^Link: \(.*\)$/\1/' | tr '\012' ' '`
 AC_MSG_RESULT($sysdep_dirs)
 AC_SUBST(sysdep_dirs)
 
+if test "$with_iproutedir" = no ; then with_iproutedir= ; fi
+
+if test -n "$given_iproutedir"
+then iproutedir=$with_iproutedir
+else iproutedir=$default_iproutedir
+fi
+
+AC_SUBST(iproutedir)
+
 AC_MSG_CHECKING([protocols])
 protocols=`echo "$with_protocols" | sed 's/,/ /g'`
 if test "$protocols" = no ; then protocols= ; fi
@@ -234,11 +246,14 @@ $srcdir/tools/mergedirs $srcdir $srcdir_rel $objdir $sysdep_dirs]],
 AC_CONFIG_FILES($makefiles)
 AC_OUTPUT
 
+rm -f $objdir/sysdep/paths.h
+
 cat >&AC_FD_MSG <<EOF
 
 BIRD was configured with the following options:
 	Source directory:	$srcdir
 	Object directory:	$objdir
+	Iproute2 directory:	$iproutedir
 	System configuration:	$sysdesc
 	Debugging:		$enable_debug
 	Routing protocols:	$protocols

doc/bird.sgml

@@ -266,8 +266,10 @@ protocol rip {
 	about configuring protocols in their own chapters. You can run more than one instance of
 	most protocols (like RIP or BGP). By default, no instances are configured.
 
-	<tag>define <m/constant/ = (<m/expression/)|<m/number/|<m/IP address/</tag> Define a constant. You can use it later in every place
-	you could use a simple integer or an IP address.
+	<tag>define <m/constant/ = (<m/expression/)|<m/number/|<m/IP address/</tag>
+	Define a constant. You can use it later in every place you could use a simple integer or an IP address.
+	Besides, there are some predefined numeric constants based on /etc/iproute2/rt_* files.
+	A list of defined constants can be seen (together with other symbols) using 'show symbols' command.
 
 	<tag>router id <m/IPv4 address/</tag> Set BIRD's router ID. It's a world-wide unique identification of your router, usually one of router's IPv4 addresses. Default: in IPv4 version, the lowest IP address of a non-loopback interface. In IPv6 version, this option is mandatory. 
 

sysdep/unix/main.c

@@ -62,6 +62,66 @@ async_dump(void)
  *	Reading the Configuration
  */
 
+#ifdef PATH_IPROUTE_DIR
+
+static inline void
+add_num_const(char *name, int val)
+{
+  struct symbol *s = cf_find_symbol(name);
+  s->class = SYM_NUMBER;
+  s->def = NULL;
+  s->aux = val;
+}
+
+/* the code of read_iproute_table() is based on
+   rtnl_tab_initialize() from iproute2 package */
+static void
+read_iproute_table(char *file, char *prefix, int max)
+{
+  char buf[512], namebuf[512];
+  char *name;
+  int val;
+  FILE *fp;
+
+  strcpy(namebuf, prefix);
+  name = namebuf + strlen(prefix);
+
+  fp = fopen(file, "r");
+  if (!fp)
+    return;
+
+  while (fgets(buf, sizeof(buf), fp))
+  {
+    char *p = buf;
+
+    while (*p == ' ' || *p == '\t')
+      p++;
+
+    if (*p == '#' || *p == '\n' || *p == 0)
+      continue;
+   
+    if (sscanf(p, "0x%x %s\n", &val, name) != 2 &&
+	sscanf(p, "0x%x %s #", &val, name) != 2 &&
+	sscanf(p, "%d %s\n", &val, name) != 2 &&
+	sscanf(p, "%d %s #", &val, name) != 2)
+      continue;
+
+    if (val < 0 || val > max)
+      continue;
+
+    for(p = name; *p; p++)
+      if ((*p < 'a' || *p > 'z') && (*p < '0' || *p > '9') && (*p != '_'))
+	*p = '_';
+
+    add_num_const(namebuf, val);
+  }
+
+  fclose(fp);
+}
+
+#endif // PATH_IPROUTE_DIR
+
+
 static int conf_fd;
 static char *config_name = PATH_CONFIG;
 
@@ -78,6 +138,13 @@ void
 sysdep_preconfig(struct config *c)
 {
   init_list(&c->logfiles);
+
+#ifdef PATH_IPROUTE_DIR
+  // read_iproute_table(PATH_IPROUTE_DIR "/rt_protos", "ipp_", 256);
+  read_iproute_table(PATH_IPROUTE_DIR "/rt_realms", "ipr_", 256);
+  read_iproute_table(PATH_IPROUTE_DIR "/rt_scopes", "ips_", 256);
+  read_iproute_table(PATH_IPROUTE_DIR "/rt_tables", "ipt_", 256);
+#endif
 }
 
 int

tools/Makefile.in

@@ -50,6 +50,7 @@ sysdep/paths.h:
 	echo >sysdep/paths.h "/* Generated by Makefile, don't edit manually! */"
 	echo >>sysdep/paths.h "#define PATH_CONFIG_DIR \"$(sysconfdir)\""
 	echo >>sysdep/paths.h "#define PATH_CONTROL_SOCKET_DIR \"$(localstatedir)/run\""
+	if test -n "@iproutedir@" ; then echo >>sysdep/paths.h "#define PATH_IPROUTE_DIR \"@iproutedir@\"" ; fi
 
 tags:
 	cd $(srcdir) ; etags -lc `find $(static-dirs) $(addprefix $(objdir)/,$(dynamic-dirs)) $(client-dirs) -name *.[chY]`