BGP: Mandatory option for channels (3c360581) · Commits · 戴 / Bird

doc/bird.sgml

+9 −0

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		@@ -2565,6 +2565,15 @@ be used in explicit configuration.
		<p>BGP channels have additional config options (together with the common ones):

		<descrip>
		<tag><label id="bgp-mandatory">mandatory <m/switch/</tag>
		When local and neighbor sets of configured AFI/SAFI pairs differ,
		capability negotiation ensures that a common subset is used. For
		mandatory channels their associated AFI/SAFI must be negotiated
		(i.e., also announced by the neighbor), otherwise BGP session
		negotiation fails with <it/'Required capability missing'/ error.
		Regardless, at least one AFI/SAFI must be negotiated in order to BGP
		session be successfully established. Default: off.

		<tag><label id="bgp-next-hop-keep">next hop keep <m/switch/\|ibgp\|ebgp</tag>
		Do not modify the Next Hop attribute and advertise the current one
		unchanged even in cases where our own local address should be used

+1 −0

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		@@ -136,6 +136,7 @@ struct bgp_channel_config {
		ip_addr next_hop_addr; /* Local address for NEXT_HOP attribute */
		u8 next_hop_self; /* Always set next hop to local IP address (NH_) /
		u8 next_hop_keep; /* Do not modify next hop attribute (NH_) /
		u8 mandatory; /* Channel is mandatory in capability negotiation */
		u8 missing_lladdr; /* What we will do when we don' know link-local addr, see MLL_* */
		u8 gw_mode; /* How we compute route gateway from next_hop attr, see GW_* */
		u8 secondary; /* Accept also non-best routes (i.e. RA_ACCEPTED) */

+2 −1

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		@@ -29,7 +29,7 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY, KEEPALIVE,
		SECURITY, DETERMINISTIC, SECONDARY, ALLOW, BFD, ADD, PATHS, RX, TX,
		GRACEFUL, RESTART, AWARE, CHECK, LINK, PORT, EXTENDED, MESSAGES, SETKEY,
		STRICT, BIND, CONFEDERATION, MEMBER, MULTICAST, FLOW4, FLOW6, LONG,
		LIVED, STALE, IMPORT, IBGP, EBGP)
		LIVED, STALE, IMPORT, IBGP, EBGP, MANDATORY)

		%type <i> bgp_nh
		%type <i32> bgp_afi
		@@ -223,6 +223,7 @@ bgp_channel_item:
		\| NEXT HOP ADDRESS ipa { BGP_CC->next_hop_addr = $4; }
		\| NEXT HOP SELF bgp_nh { BGP_CC->next_hop_self = $4; }
		\| NEXT HOP KEEP bgp_nh { BGP_CC->next_hop_keep = $4; }
		\| MANDATORY bool { BGP_CC->mandatory = $2; }
		\| MISSING LLADDR SELF { BGP_CC->missing_lladdr = MLL_SELF; }
		\| MISSING LLADDR DROP { BGP_CC->missing_lladdr = MLL_DROP; }
		\| MISSING LLADDR IGNORE { BGP_CC->missing_lladdr = MLL_IGNORE; }

+40 −0

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		@@ -573,6 +573,42 @@ err:
		return;
		}

		static int
		bgp_check_capabilities(struct bgp_conn *conn)
		{
		struct bgp_proto *p = conn->bgp;
		struct bgp_caps *local = conn->local_caps;
		struct bgp_caps *remote = conn->remote_caps;
		struct bgp_channel *c;
		int count = 0;

		/* This is partially overlapping with bgp_conn_enter_established_state(),
		but we need to run this just after we receive OPEN message */

		WALK_LIST(c, p->p.channels)
		{
		const struct bgp_af_caps *loc = bgp_find_af_caps(local, c->afi);
		const struct bgp_af_caps *rem = bgp_find_af_caps(remote, c->afi);

		/* Find out whether this channel will be active */
		int active = loc && loc->ready &&
		((rem && rem->ready) \|\| (!remote->length && (c->afi == BGP_AF_IPV4)));

		/* Mandatory must be active */
		if (c->cf->mandatory && !active)
		return 0;

		if (active)
		count++;
		}

		/* We need at least one channel active */
		if (!count)
		return 0;

		return 1;
		}

		static int
		bgp_read_options(struct bgp_conn conn, byte pos, int len)
		{
		@@ -683,6 +719,10 @@ bgp_rx_open(struct bgp_conn conn, byte pkt, uint len)
		if (!id \|\| (p->is_internal && id == p->local_id))
		{ bgp_error(conn, 2, 3, pkt+24, -4); return; }

		/* RFC 5492 4 - check for required capabilities */
		if (p->cf->capabilities && !bgp_check_capabilities(conn))
		{ bgp_error(conn, 2, 7, NULL, 0); return; }

		struct bgp_caps *caps = conn->remote_caps;

		if (caps->as4_support)