BGP: Promiscuous ASN mode
Allow to specify just 'internal' or 'external' for remote neighbor instead of specific ASN. In the second case that means BGP peers with any non-local ASNs are accepted.
This commit is contained in:
Ondrej Zajicek (work)
parent
a22c3e5968
commit
23ee6b1cd6
5 changed files with 42 additions and 12 deletions
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@ -2195,12 +2195,15 @@ using the following configuration parameters:
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<cf/local 10.0.0.1; local as 65000;/ are valid). This parameter is
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mandatory.
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<tag><label id="bgp-neighbor">neighbor [<m/ip/] [port <m/number/] [as <m/number/]</tag>
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<tag><label id="bgp-neighbor">neighbor [<m/ip/] [port <m/number/] [as <m/number/] [internal|external]</tag>
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Define neighboring router this instance will be talking to and what AS
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it is located in. In case the neighbor is in the same AS as we are, we
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automatically switch to iBGP. Optionally, the remote port may also be
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specified. Like <cf/local/ parameter, this parameter may also be used
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multiple times with different sub-options. This parameter is mandatory.
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automatically switch to IBGP. Alternatively, it is possible to specify
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just <cf/internal/ or </cf/external/ instead of AS number, in that case
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either local AS number, or any external AS number is accepted.
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Optionally, the remote port may also be specified. Like <cf/local/
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parameter, this parameter may also be used multiple times with different
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sub-options. This parameter is mandatory.
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<tag><label id="bgp-iface">interface <m/string/</tag>
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Define interface we should use for link-local BGP IPv6 sessions.
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@ -507,6 +507,10 @@ bgp_conn_enter_established_state(struct bgp_conn *conn)
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if (ipa_zero(p->local_ip))
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p->local_ip = conn->sk->saddr;
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/* For promiscuous sessions */
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if (!p->remote_as)
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p->remote_as = conn->received_as;
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/* In case of LLv6 is not valid during BGP start */
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if (ipa_zero(p->link_addr) && p->neigh && p->neigh->iface && p->neigh->iface->llv6)
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p->link_addr = p->neigh->iface->llv6->ip;
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@ -1754,14 +1758,19 @@ void
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bgp_postconfig(struct proto_config *CF)
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{
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struct bgp_config *cf = (void *) CF;
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int internal = (cf->local_as == cf->remote_as);
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int interior = internal || cf->confederation_member;
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/* Do not check templates at all */
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if (cf->c.class == SYM_TEMPLATE)
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return;
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/* Handle undefined remote_as, zero should mean unspecified external */
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if (!cf->remote_as && (cf->peer_type == BGP_PT_INTERNAL))
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cf->remote_as = cf->local_as;
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int internal = (cf->local_as == cf->remote_as);
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int interior = internal || cf->confederation_member;
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/* EBGP direct by default, IBGP multihop by default */
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if (cf->multihop < 0)
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cf->multihop = internal ? 64 : 0;
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@ -1781,8 +1790,14 @@ bgp_postconfig(struct proto_config *CF)
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if (ipa_zero(cf->remote_ip))
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cf_error("Neighbor must be configured");
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if (!cf->remote_as)
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cf_error("Remote AS number must be set");
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if (!cf->remote_as && !cf->peer_type)
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cf_error("Remote AS number (or peer type) must be set");
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if ((cf->peer_type == BGP_PT_INTERNAL) && !internal)
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cf_error("IBGP cannot have different ASNs");
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if ((cf->peer_type == BGP_PT_EXTERNAL) && internal)
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cf_error("EBGP cannot have the same ASNs");
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if (!cf->iface && (ipa_is_link_local(cf->local_ip) ||
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ipa_is_link_local(cf->remote_ip)))
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@ -2242,7 +2257,7 @@ bgp_show_proto_info(struct proto *P)
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cli_msg(-1006, " BGP state: %s", bgp_state_dsc(p));
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cli_msg(-1006, " Neighbor address: %I%J", p->cf->remote_ip, p->cf->iface);
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cli_msg(-1006, " Neighbor AS: %u", p->cf->remote_as);
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cli_msg(-1006, " Neighbor AS: %u", p->cf->remote_as ?: p->remote_as);
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if (p->gr_active_num)
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cli_msg(-1006, " Neighbor graceful restart active");
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@ -83,6 +83,7 @@ struct bgp_config {
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struct iface *iface; /* Interface for link-local addresses */
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u16 local_port; /* Local listening port */
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u16 remote_port; /* Neighbor destination port */
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int peer_type; /* Internal or external BGP (BGP_PT_*, optional) */
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int multihop; /* Number of hops if multihop */
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int strict_bind; /* Bind listening socket to local address */
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int ttl_security; /* Enable TTL security [RFC 5082] */
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@ -152,6 +153,9 @@ struct bgp_channel_config {
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struct rtable_config *igp_table_ip6; /* Table for recursive IPv6 next hop lookups */
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};
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#define BGP_PT_INTERNAL 1
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#define BGP_PT_EXTERNAL 2
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#define NH_NO 0
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#define NH_ALL 1
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#define NH_IBGP 2
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@ -237,6 +241,7 @@ struct bgp_conn {
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u8 state; /* State of connection state machine */
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u8 as4_session; /* Session uses 4B AS numbers in AS_PATH (both sides support it) */
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u8 ext_messages; /* Session uses extended message length */
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u32 received_as; /* ASN received in OPEN message */
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struct bgp_caps *local_caps;
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struct bgp_caps *remote_caps;
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@ -29,7 +29,7 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY, KEEPALIVE,
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SECURITY, DETERMINISTIC, SECONDARY, ALLOW, BFD, ADD, PATHS, RX, TX,
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GRACEFUL, RESTART, AWARE, CHECK, LINK, PORT, EXTENDED, MESSAGES, SETKEY,
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STRICT, BIND, CONFEDERATION, MEMBER, MULTICAST, FLOW4, FLOW6, LONG,
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LIVED, STALE, IMPORT, IBGP, EBGP, MANDATORY)
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LIVED, STALE, IMPORT, IBGP, EBGP, MANDATORY, INTERNAL, EXTERNAL)
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%type <i> bgp_nh
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%type <i32> bgp_afi
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@ -82,6 +82,8 @@ bgp_nbr_opts:
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/* empty */
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| bgp_nbr_opts PORT expr { BGP_CFG->remote_port = $3; if (($3<1) || ($3>65535)) cf_error("Invalid port number"); }
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| bgp_nbr_opts AS expr { BGP_CFG->remote_as = $3; }
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| bgp_nbr_opts INTERNAL { BGP_CFG->peer_type = BGP_PT_INTERNAL; }
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| bgp_nbr_opts EXTERNAL { BGP_CFG->peer_type = BGP_PT_EXTERNAL; }
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;
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bgp_cease_mask:
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@ -732,13 +732,18 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, uint len)
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if ((as4 != asn) && (asn != AS_TRANS))
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log(L_WARN "%s: Peer advertised inconsistent AS numbers", p->p.name);
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if (as4 != p->remote_as)
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/* When remote ASN is unspecified, it must be external one */
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if (p->remote_as ? (as4 != p->remote_as) : (as4 == p->local_as))
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{ as4 = htonl(as4); bgp_error(conn, 2, 2, (byte *) &as4, 4); return; }
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conn->received_as = as4;
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}
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else
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{
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if (asn != p->remote_as)
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if (p->remote_as ? (asn != p->remote_as) : (asn == p->local_as))
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{ bgp_error(conn, 2, 2, pkt+20, 2); return; }
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conn->received_as = asn;
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}
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/* Check the other connection */
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