extend filter language to allow basic setting of COMMUNITIES attribute.

ok claudio@

6 files changed, 147 insertions, 29 deletions

diff --git a/usr.sbin/bgpd/bgpd.conf.5 b/usr.sbin/bgpd/bgpd.conf.5
index 00e1aca6e99..51ffdc06084 100644
--- a/usr.sbin/bgpd/bgpd.conf.5
+++ b/usr.sbin/bgpd/bgpd.conf.5
@@ -1,4 +1,4 @@
-.\" $OpenBSD: bgpd.conf.5,v 1.24 2004/05/08 20:18:45 henning Exp $
+.\" $OpenBSD: bgpd.conf.5,v 1.25 2004/05/17 12:39:32 djm Exp $
 .\"
 .\" Copyright (c) 2004 Claudio Jeker <claudio@openbsd.org>
 .\" Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -611,6 +611,22 @@ The following attributes can be modified:
 Set the
 .Em LOCAL_PREF
 .Em AS path attribute .
+.It Ar community
+Set the
+.Em COMMUNITIES
+.Em AS path attribute .
+Communities are specified as 
+.Ar asnum:local ,
+where
+.Ar asnum
+is an AS number and
+.Ar local
+is a locally-significant number between zero and 0xffff.
+Alternately, well-known communities may be specified by name: 
+.Em NO_EXPORT ,
+.Em NO_ADVERTISE ,
+or 
+.Em NO_EXPORT_SUBCONFED .
 .It Ar med
 Set the
 .Em MULTI_EXIT_DISC
diff --git a/usr.sbin/bgpd/bgpd.h b/usr.sbin/bgpd/bgpd.h
index 84bf565b866..d8f54b081fe 100644
--- a/usr.sbin/bgpd/bgpd.h
+++ b/usr.sbin/bgpd/bgpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bgpd.h,v 1.122 2004/05/07 10:06:15 djm Exp $ */
+/*	$OpenBSD: bgpd.h,v 1.123 2004/05/17 12:39:32 djm Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -146,6 +146,10 @@ struct filter_set {
 	struct in6_addr	nexthop6;
 	u_int8_t	prepend;
 	char		pftable[PFTABLE_LEN];
+	struct {
+		int	as;
+		int	type;
+	} community;
 };
 
 enum auth_method {
@@ -438,6 +442,7 @@ enum comp_ops {
 #define	SET_NEXTHOP6	0x08
 #define	SET_PREPEND	0x10
 #define	SET_PFTABLE	0x20
+#define	SET_COMMUNITY	0x40
 
 struct filter_peers {
 	u_int32_t	peerid;
diff --git a/usr.sbin/bgpd/parse.y b/usr.sbin/bgpd/parse.y
index 91647e5b16f..92f73b5ff0a 100644
--- a/usr.sbin/bgpd/parse.y
+++ b/usr.sbin/bgpd/parse.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.110 2004/05/08 20:58:00 henning Exp $ */
+/*	$OpenBSD: parse.y,v 1.111 2004/05/17 12:39:32 djm Exp $ */
 
 /*
  * Copyright (c) 2002, 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -84,6 +84,7 @@ int	 symset(const char *, const char *, int);
 char	*symget(const char *);
 int	 atoul(char *, u_long *);
 int	 getcommunity(char *);
+int	 parsecommunity(char *, int *, int *);
 
 typedef struct {
 	union {
@@ -791,32 +792,13 @@ filter_match	: /* empty */			{ bzero(&$$, sizeof($$)); }
 			$$.as.type = $1;
 		}
 		| COMMUNITY STRING	{
-			char	*p;
-			int	 i;
-
 			bzero(&$$, sizeof($$));
-			if ((p = strchr($2, ':')) == NULL) {
-				free($2);
-				yyerror("Bad community syntax");
-				YYERROR;
-			}
-			*p++ = 0;
-			if ((i = getcommunity($2)) == COMMUNITY_ERROR) {
-				free($2);
-				YYERROR;
-			}
-			if (i == 0 || i == USHRT_MAX) {
-				free($2);
-				yyerror("Bad community AS number");
-				YYERROR;
-			}
-			$$.community.as = i;
-			if ((i = getcommunity(p)) == COMMUNITY_ERROR) {
+			if (parsecommunity($2, &$$.community.as,
+			    &$$.community.type) == -1) {
 				free($2);
 				YYERROR;
 			}
 			free($2);
-			$$.community.type = i;
 		}
 		;
 
@@ -876,6 +858,10 @@ filter_set_l	: filter_set_l comma filter_set_opt	{
 			if ($3.flags & SET_PFTABLE)
 				strlcpy($$.pftable, $3.pftable,
 				    sizeof($$.pftable));
+			if ($3.flags & SET_COMMUNITY) {
+				$$.community.as = $3.community.as;
+				$$.community.type = $3.community.type;
+			}
 		}
 		| filter_set_opt
 		;
@@ -917,6 +903,34 @@ filter_set_opt	: LOCALPREF number		{
 				YYERROR;
 			}
 		}
+		| COMMUNITY STRING		{
+			$$.flags = SET_COMMUNITY;
+			if (parsecommunity($2, &$$.community.as,
+			    &$$.community.type) == -1) {
+				free($2);
+				YYERROR;
+			}
+			free($2);
+			if ($$.community.as <= 0 || $$.community.as > 0xffff) {
+				yyerror("Invalid comminity");
+				YYERROR;
+			}
+			/* Don't allow setting of unknown well-known types */
+			if ($$.community.as == COMMUNITY_WELLKNOWN) {
+				switch ($$.community.type) {
+				case COMMUNITY_NO_EXPORT:
+				case COMMUNITY_NO_ADVERTISE:
+				case COMMUNITY_NO_EXPSUBCONFED:
+					/* valid */
+					break;
+				default:
+					/* unknown */
+					yyerror("Invalid well-known community");
+					YYERROR;
+					break;
+				}
+			}
+		}
 		;
 
 comma		: ","
@@ -1418,6 +1432,48 @@ getcommunity(char *s)
 	return (ulval);
 }
 
+int
+parsecommunity(char *s, int *as, int *type)
+{
+	char *p;
+	int i;
+
+	/* Well-known communities */
+	if (strcasecmp(s, "NO_EXPORT") == 0) {
+		*as = COMMUNITY_WELLKNOWN;
+		*type = COMMUNITY_NO_EXPORT;
+		return (0);
+	} else if (strcasecmp(s, "NO_ADVERTISE") == 0) {
+		*as = COMMUNITY_WELLKNOWN;
+		*type = COMMUNITY_NO_ADVERTISE;
+		return (0);
+	} else if (strcasecmp(s, "NO_EXPORT_SUBCONFED") == 0) {
+		*as = COMMUNITY_WELLKNOWN;
+		*type = COMMUNITY_NO_EXPSUBCONFED;
+		return (0);
+	}
+
+	if ((p = strchr(s, ':')) == NULL) {
+		yyerror("Bad community syntax");
+		return (-1);
+	}
+	*p++ = 0;
+
+	if ((i = getcommunity(s)) == COMMUNITY_ERROR)
+		return (-1);
+	if (i == 0 || i == USHRT_MAX) {
+		yyerror("Bad community AS number");
+		return (-1);
+	}
+	*as = i;
+
+	if ((i = getcommunity(p)) == COMMUNITY_ERROR)
+		return (-1);
+	*type = i;
+
+	return (0);
+}
+
 struct peer *
 alloc_peer(void)
 {
@@ -1621,4 +1677,4 @@ neighbor_consistent(struct peer *p)
 	}
 
 	return (0);
-}
\ No newline at end of file
+}
diff --git a/usr.sbin/bgpd/rde.h b/usr.sbin/bgpd/rde.h
index cb6a249359b..6b37632841e 100644
--- a/usr.sbin/bgpd/rde.h
+++ b/usr.sbin/bgpd/rde.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde.h,v 1.38 2004/05/07 10:06:15 djm Exp $ */
+/*	$OpenBSD: rde.h,v 1.39 2004/05/17 12:39:32 djm Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Claudio Jeker <claudio@openbsd.org> and
@@ -251,6 +251,7 @@ int		 aspath_asprint(char **, void *, u_int16_t);
 size_t		 aspath_strlen(void *, u_int16_t);
 int		 aspath_match(struct aspath *, enum as_spec, u_int16_t);
 int		 community_match(void *, u_int16_t, int, int);
+int		 community_set(struct attr *, int, int);
 
 /* rde_rib.c */
 void		 path_init(u_int32_t);
diff --git a/usr.sbin/bgpd/rde_attr.c b/usr.sbin/bgpd/rde_attr.c
index 8ec8450c942..772aa5bd2f3 100644
--- a/usr.sbin/bgpd/rde_attr.c
+++ b/usr.sbin/bgpd/rde_attr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde_attr.c,v 1.29 2004/05/07 10:06:15 djm Exp $ */
+/*	$OpenBSD: rde_attr.c,v 1.30 2004/05/17 12:39:32 djm Exp $ */
 
 /*
  * Copyright (c) 2004 Claudio Jeker <claudio@openbsd.org>
@@ -993,7 +993,7 @@ community_match(void *data, u_int16_t len, int as, int type)
 	u_int16_t	 eas, etype;
 
 	ENSURE((len & 0x3) == 0);
-	len >>= 2; /* devide by four */
+	len >>= 2; /* divide by four */
 
 	for (; len > 0; len--) {
 		eas = *p++;
@@ -1009,3 +1009,32 @@ community_match(void *data, u_int16_t len, int as, int type)
 	return 0;
 }
 
+int
+community_set(struct attr *attr, int as, int type)
+{
+	u_int32_t *cdata = (u_int32_t*)attr->data;
+	unsigned int i, ncommunities = attr->len;
+
+	ENSURE((as & ~0xffff) == 0);
+	ENSURE((type & ~0xffff) == 0);
+	ENSURE((ncommunities & 0x3) == 0);
+	ncommunities >>= 2; /* divide by four */
+
+	for (i = 0; i < ncommunities; i++) {
+		if ((ntohl(cdata[i]) & 0xffff0000) == (unsigned)as << 16)
+			break;
+	}
+
+	if (i >= ncommunities) {
+		if (attr->len + 4 > 0xffff) /* overflow */
+			return (0);
+		attr->len += 4;
+		if ((cdata = realloc(attr->data, attr->len)) == NULL)
+			return (0);
+		attr->data = (void*)cdata;
+	}
+	cdata[i] = htonl(as << 16 | type);
+
+	return (1);
+}
+
diff --git a/usr.sbin/bgpd/rde_filter.c b/usr.sbin/bgpd/rde_filter.c
index 5a8a0923651..619dfc9dc74 100644
--- a/usr.sbin/bgpd/rde_filter.c
+++ b/usr.sbin/bgpd/rde_filter.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde_filter.c,v 1.8 2004/05/07 10:06:15 djm Exp $ */
+/*	$OpenBSD: rde_filter.c,v 1.9 2004/05/17 12:39:32 djm Exp $ */
 
 /*
  * Copyright (c) 2004 Claudio Jeker <claudio@openbsd.org>
@@ -78,6 +78,17 @@ rde_apply_set(struct attr_flags *attrs, struct filter_set *set)
 	}
 	if (set->flags & SET_PFTABLE)
 		strlcpy(attrs->pftable, set->pftable, sizeof(attrs->pftable));
+	if (set->flags & SET_COMMUNITY) {
+		struct attr *a;
+
+		if ((a = attr_optget(attrs, ATTR_COMMUNITIES)) == NULL) {
+			attr_optadd(attrs, ATTR_OPTIONAL|ATTR_TRANSITIVE,
+			    ATTR_COMMUNITIES, NULL, 0);
+			if ((a = attr_optget(attrs, ATTR_COMMUNITIES)) == NULL)
+				fatalx("internal community bug");
+		}
+		community_set(a, set->community.as, set->community.type);
+	}
 }
 
 int