Rewrites static attribute filter code and adds ifname/ifindex attributes.

Thanks to Sergey Popovich for the original ifname/ifindex patch.

4 files changed, 75 insertions, 44 deletions

diff --git a/doc/bird.sgml b/doc/bird.sgml
index b3f6a85c..f43eb4bf 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -928,10 +928,16 @@ incompatible with each other (that is to prevent you from shooting in the foot).
 	  from 0 to 255. Literals of this type are written like IPv4
 	  addresses.
 
-	<tag/string/ This is a string of characters. There are no ways to modify strings in
-	  filters. You can pass them between functions, assign them to variables of type <cf/string/, print
-	  such variables, but you can't concatenate two strings. String literals
-	  are written as <cf/"This is a string constant"/.
+	<tag/string/ This is a string of characters. There are no ways
+	  to modify strings in filters. You can pass them between
+	  functions, assign them to variables of type <cf/string/,
+	  print such variables, use standard string comparison
+	  operations (e.g. <cf/=, !=, &lt;, &gt;, &lt;=, &gt;=/), but
+	  you can't concatenate two strings. String literals are
+	  written as <cf/"This is a string constant"/. Additionaly
+	  matching <cf/&tilde;/ operator could be used to match a
+	  string value against a shell pattern (represented also as a
+	  string).
 
 	<tag/ip/ This type can hold a single IP address. Depending on the compile-time configuration of BIRD you are using, it
 	  is either an IPv4 or IPv6 address. IP addresses are written in the standard notation (<cf/10.20.30.40/ or <cf/fec0:3:4::1/). You can apply special operator <cf>.mask(<M>num</M>)</cf>
@@ -1194,7 +1200,6 @@ undefined value is regarded as empty clist for most purposes.
 	what protocol has told me about this route. Possible values: <cf/RTS_DUMMY/, <cf/RTS_STATIC/, <cf/RTS_INHERIT/, <cf/RTS_DEVICE/, <cf/RTS_STATIC_DEVICE/, <cf/RTS_REDIRECT/, <cf/RTS_RIP/, <cf/RTS_OSPF/, <cf/RTS_OSPF_IA/, <cf/RTS_OSPF_EXT1/, <cf/RTS_OSPF_EXT2/, <cf/RTS_BGP/, <cf/RTS_PIPE/.
 
 	<tag><m/enum/ cast</tag>
-
 	Route type (Currently <cf/RTC_UNICAST/ for normal routes,
 	<cf/RTC_BROADCAST/, <cf/RTC_MULTICAST/, <cf/RTC_ANYCAST/ will
 	be used in the future for broadcast, multicast and anycast
@@ -1212,6 +1217,19 @@ undefined value is regarded as empty clist for most purposes.
 	only to <cf/RTD_BLACKHOLE/, <cf/RTD_UNREACHABLE/ or
 	<cf/RTD_PROHIBIT/.
 
+	<tag><m/string/ ifname</tag>
+	Name of the outgoing interface. Sink routes (like blackhole,
+	unreachable or prohibit) and multipath routes have no interface
+	associated with them, so <cf/ifname/ returns an empty string for
+	such routes. Read-only.
+
+	<tag><m/int/ ifindex</tag>
+	Index of the outgoing interface. System wide index of the
+	interface. May be used for interface matching, however
+	indexes might change on interface creation/removal. Zero is
+	returned for routes with undefined outgoing
+	interfaces. Read-only.
+
 	<tag><m/int/ igp_metric</tag>
 	The optional attribute that can be used to specify a distance
 	to the network for routes that do not have a native protocol
diff --git a/filter/config.Y b/filter/config.Y
index 66234050..04acfbab 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -261,7 +261,8 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
 	SET, STRING, BGPMASK, BGPPATH, CLIST, ECLIST,
 	IF, THEN, ELSE, CASE,
 	TRUE, FALSE, RT, RO, UNKNOWN, GENERIC,
-	FROM, GW, NET, MASK, PROTO, SOURCE, SCOPE, CAST, DEST, PREFERENCE,
+	FROM, GW, NET, MASK, PROTO, SOURCE, SCOPE, CAST, DEST, IFNAME, IFINDEX,
+	PREFERENCE,
 	LEN,
 	DEFINED,
 	ADD, DELETE, CONTAINS, RESET,
@@ -680,14 +681,16 @@ symbol:
    }
 
 static_attr:
-   FROM    { $$ = f_new_inst(); $$->aux = T_IP;         $$->a2.i = OFFSETOF(struct rta, from);   $$->a1.i = 1; }
- | GW      { $$ = f_new_inst(); $$->aux = T_IP;         $$->a2.i = OFFSETOF(struct rta, gw);     $$->a1.i = 1; }
- | NET     { $$ = f_new_inst(); $$->aux = T_PREFIX;     $$->a2.i = 0x12345678; /* This is actually ok - T_PREFIX is special-cased. */ }
- | PROTO   { $$ = f_new_inst(); $$->aux = T_STRING;     $$->a2.i = 0x12345678; /* T_STRING is also special-cased. */ }
- | SOURCE  { $$ = f_new_inst(); $$->aux = T_ENUM_RTS;   $$->a2.i = OFFSETOF(struct rta, source); }
- | SCOPE   { $$ = f_new_inst(); $$->aux = T_ENUM_SCOPE; $$->a2.i = OFFSETOF(struct rta, scope);  $$->a1.i = 1; }
- | CAST    { $$ = f_new_inst(); $$->aux = T_ENUM_RTC;   $$->a2.i = OFFSETOF(struct rta, cast); }
- | DEST    { $$ = f_new_inst(); $$->aux = T_ENUM_RTD;   $$->a2.i = OFFSETOF(struct rta, dest);   $$->a1.i = 1; }
+   FROM    { $$ = f_new_inst(); $$->aux = T_IP;         $$->a2.i = SA_FROM;	$$->a1.i = 1; }
+ | GW      { $$ = f_new_inst(); $$->aux = T_IP;         $$->a2.i = SA_GW;	$$->a1.i = 1; }
+ | NET     { $$ = f_new_inst(); $$->aux = T_PREFIX;     $$->a2.i = SA_NET; }
+ | PROTO   { $$ = f_new_inst(); $$->aux = T_STRING;     $$->a2.i = SA_PROTO; }
+ | SOURCE  { $$ = f_new_inst(); $$->aux = T_ENUM_RTS;   $$->a2.i = SA_SOURCE; }
+ | SCOPE   { $$ = f_new_inst(); $$->aux = T_ENUM_SCOPE; $$->a2.i = SA_SCOPE;	$$->a1.i = 1; }
+ | CAST    { $$ = f_new_inst(); $$->aux = T_ENUM_RTC;   $$->a2.i = SA_CAST; }
+ | DEST    { $$ = f_new_inst(); $$->aux = T_ENUM_RTD;   $$->a2.i = SA_DEST;	$$->a1.i = 1; }
+ | IFNAME  { $$ = f_new_inst(); $$->aux = T_STRING;     $$->a2.i = SA_IFNAME; }
+ | IFINDEX { $$ = f_new_inst(); $$->aux = T_INT;        $$->a2.i = SA_IFINDEX; }
  ;
 
 term:
diff --git a/filter/filter.c b/filter/filter.c
index 1f090528..0fc10f1f 100644
--- a/filter/filter.c
+++ b/filter/filter.c
@@ -824,24 +824,23 @@ interpret(struct f_inst *what)
       ACCESS_RTE;
       struct rta *rta = (*f_rte)->attrs;
       res.type = what->aux;
-      switch(res.type) {
-      case T_IP:
-	res.val.px.ip = * (ip_addr *) ((char *) rta + what->a2.i);
-	break;
-      case T_ENUM:
-	res.val.i = * ((char *) rta + what->a2.i);
-	break;
-      case T_STRING:	/* Warning: this is a special case for proto attribute */
-	res.val.s = rta->proto->name;
-	break;
-      case T_PREFIX:	/* Warning: this works only for prefix of network */
-	{
-	  res.val.px.ip = (*f_rte)->net->n.prefix;
-	  res.val.px.len = (*f_rte)->net->n.pxlen;
-	  break;
-	}
+
+      switch (what->a2.i)
+      {
+      case SA_FROM:	res.val.px.ip = rta->from; break;
+      case SA_GW:	res.val.px.ip = rta->gw; break;
+      case SA_NET:	res.val.px.ip = (*f_rte)->net->n.prefix;
+			res.val.px.len = (*f_rte)->net->n.pxlen; break;
+      case SA_PROTO:	res.val.s = rta->proto->name; break;
+      case SA_SOURCE:	res.val.i = rta->source; break;
+      case SA_SCOPE:	res.val.i = rta->scope; break;
+      case SA_CAST:	res.val.i = rta->cast; break;
+      case SA_DEST:	res.val.i = rta->dest; break;
+      case SA_IFNAME:	res.val.s = rta->iface ? rta->iface->name : ""; break;
+      case SA_IFINDEX:	res.val.i = rta->iface ? rta->iface->index : 0; break;
+
       default:
-	bug( "Invalid type for rta access (%x)", res.type );
+	bug("Invalid static attribute access (%x)", res.type);
       }
     }
     break;
@@ -850,19 +849,20 @@ interpret(struct f_inst *what)
     ONEARG;
     if (what->aux != v1.type)
       runtime( "Attempt to set static attribute to incompatible type" );
+
     f_rta_cow();
     {
       struct rta *rta = (*f_rte)->attrs;
-      ip_addr ip;
-
-      switch (what->aux) {
 
-      case T_IP:
-	ip = v1.val.px.ip;
+      switch (what->a2.i)
+      {
+      case SA_FROM:
+	rta->from = v1.val.px.ip;
+	break;
 
-	/* "gw" attribute? */
-	if (what->a2.i == OFFSETOF(struct rta, gw))
+      case SA_GW:
 	{
+	  ip_addr ip = v1.val.px.ip;
 	  neighbor *n = neigh_find(rta->proto, &ip, 0);
 	  if (!n || (n->scope == SCOPE_HOST))
 	    runtime( "Invalid gw address" );
@@ -873,16 +873,13 @@ interpret(struct f_inst *what)
 	  rta->nexthops = NULL;
 	  rta->hostentry = NULL;
 	}
-	else /* or "from" attribute? */
-	  rta->from = ip;
-
 	break;
 
-      case T_ENUM_SCOPE:
+      case SA_SCOPE:
 	rta->scope = v1.val.i;
 	break;
 
-      case T_ENUM_RTD:
+      case SA_DEST:
 	i = v1.val.i;
 	if ((i != RTD_BLACKHOLE) && (i != RTD_UNREACHABLE) && (i != RTD_PROHIBIT))
 	  runtime( "Destination can be changed only to blackhole, unreachable or prohibit" );
@@ -895,7 +892,7 @@ interpret(struct f_inst *what)
 	break;
 
       default:
-	bug( "Unknown type in set of static attribute" );
+	bug("Invalid static attribute access (%x)", res.type);
       }
     }
     break;
diff --git a/filter/filter.h b/filter/filter.h
index 1d5150e7..dcac8253 100644
--- a/filter/filter.h
+++ b/filter/filter.h
@@ -172,6 +172,19 @@ void val_print(struct f_val v);
 #define T_SET 0x80
 #define T_PREFIX_SET 0x81
 
+
+#define SA_FROM		 1    
+#define SA_GW		 2      
+#define SA_NET		 3     
+#define SA_PROTO	 4   
+#define SA_SOURCE	 5  
+#define SA_SCOPE	 6   
+#define SA_CAST    	 7
+#define SA_DEST    	 8
+#define SA_IFNAME  	 9
+#define SA_IFINDEX    	10
+
+
 struct f_tree {
   struct f_tree *left, *right;
   struct f_val from, to;