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-rw-r--r--proto/bgp/attrs.c69
-rw-r--r--proto/bgp/bgp.c19
-rw-r--r--proto/bgp/bgp.h17
-rw-r--r--proto/bgp/config.Y16
-rw-r--r--proto/bgp/packets.c46
5 files changed, 161 insertions, 6 deletions
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 9dd9fb1a..0d2116b7 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -896,6 +896,18 @@ bgp_decode_large_community(struct bgp_parse_state *s, uint code UNUSED, uint fla
bgp_set_attr_ptr(to, s->pool, BA_LARGE_COMMUNITY, flags, ad);
}
+
+static void
+bgp_decode_otc(struct bgp_parse_state *s, uint code UNUSED, uint flags, byte *data UNUSED, uint len, ea_list **to)
+{
+ if (len != 4)
+ WITHDRAW(BAD_LENGTH, "OTC", len);
+
+ u32 val = get_u32(data);
+ bgp_set_attr_u32(to, s->pool, BA_ONLY_TO_CUSTOMER, flags, val);
+}
+
+
static void
bgp_export_mpls_label_stack(struct bgp_export_state *s, eattr *a)
{
@@ -1109,6 +1121,13 @@ static const struct bgp_attr_desc bgp_attr_table[] = {
.encode = bgp_encode_u32s,
.decode = bgp_decode_large_community,
},
+ [BA_ONLY_TO_CUSTOMER] = {
+ .name = "otc",
+ .type = EAF_TYPE_INT,
+ .flags = BAF_OPTIONAL | BAF_TRANSITIVE,
+ .encode = bgp_encode_u32,
+ .decode = bgp_decode_otc,
+ },
[BA_MPLS_LABEL_STACK] = {
.name = "mpls_label_stack",
.type = EAF_TYPE_INT_SET,
@@ -1445,6 +1464,29 @@ bgp_finish_attrs(struct bgp_parse_state *s, rta *a)
REPORT("Discarding AIGP attribute received on non-AIGP session");
bgp_unset_attr(&a->eattrs, s->pool, BA_AIGP);
}
+
+ /* Handle OTC ingress procedure, RFC 9234 */
+ if (bgp_channel_is_role_applicable(s->channel))
+ {
+ struct bgp_proto *p = s->proto;
+ eattr *e = bgp_find_attr(a->eattrs, BA_ONLY_TO_CUSTOMER);
+
+ /* Reject routes from downstream if they are leaked */
+ if (e && (p->cf->local_role == BGP_ROLE_PROVIDER ||
+ p->cf->local_role == BGP_ROLE_RS_SERVER))
+ WITHDRAW("Route leak detected - OTC attribute from downstream");
+
+ /* Reject routes from peers if they are leaked */
+ if (e && (p->cf->local_role == BGP_ROLE_PEER) && (e->u.data != p->cf->remote_as))
+ WITHDRAW("Route leak detected - OTC attribute with mismatched ASN (%u)",
+ (uint) e->u.data);
+
+ /* Mark routes from upstream if it did not happened before */
+ if (!e && (p->cf->local_role == BGP_ROLE_CUSTOMER ||
+ p->cf->local_role == BGP_ROLE_PEER ||
+ p->cf->local_role == BGP_ROLE_RS_CLIENT))
+ bgp_set_attr_u32(&a->eattrs, s->pool, BA_ONLY_TO_CUSTOMER, 0, p->cf->remote_as);
+ }
}
@@ -1673,6 +1715,7 @@ bgp_preexport(struct channel *C, rte **new, struct linpool *pool UNUSED)
{
rte *e = *new;
struct proto *SRC = e->attrs->src->proto;
+ struct bgp_channel *c = (struct bgp_channel *) C;
struct bgp_proto *p = (struct bgp_proto *) C->proto;
struct bgp_proto *src = (SRC->proto == &proto_bgp) ? (struct bgp_proto *) SRC : NULL;
@@ -1702,11 +1745,11 @@ bgp_preexport(struct channel *C, rte **new, struct linpool *pool UNUSED)
}
/* Handle well-known communities, RFC 1997 */
- struct eattr *c;
+ struct eattr *a;
if (p->cf->interpret_communities &&
- (c = ea_find(e->attrs->eattrs, EA_CODE(PROTOCOL_BGP, BA_COMMUNITY))))
+ (a = bgp_find_attr(e->attrs->eattrs, BA_COMMUNITY)))
{
- const struct adata *d = c->u.ptr;
+ const struct adata *d = a->u.ptr;
/* Do not export anywhere */
if (int_set_contains(d, BGP_COMM_NO_ADVERTISE))
@@ -1725,6 +1768,16 @@ bgp_preexport(struct channel *C, rte **new, struct linpool *pool UNUSED)
return -1;
}
+ /* Do not export routes marked with OTC to upstream, RFC 9234 */
+ if (bgp_channel_is_role_applicable(c))
+ {
+ a = bgp_find_attr(e->attrs->eattrs, BA_ONLY_TO_CUSTOMER);
+ if (a && (p->cf->local_role==BGP_ROLE_CUSTOMER ||
+ p->cf->local_role==BGP_ROLE_PEER ||
+ p->cf->local_role==BGP_ROLE_RS_CLIENT))
+ return -1;
+ }
+
return 0;
}
@@ -1834,6 +1887,16 @@ bgp_update_attrs(struct bgp_proto *p, struct bgp_channel *c, rte *e, ea_list *at
}
}
+ /* Mark routes for downstream with OTC, RFC 9234 */
+ if (bgp_channel_is_role_applicable(c))
+ {
+ a = bgp_find_attr(attrs, BA_ONLY_TO_CUSTOMER);
+ if (!a && (p->cf->local_role == BGP_ROLE_PROVIDER ||
+ p->cf->local_role == BGP_ROLE_PEER ||
+ p->cf->local_role == BGP_ROLE_RS_SERVER))
+ bgp_set_attr_u32(&attrs, pool, BA_ONLY_TO_CUSTOMER, 0, p->public_as);
+ }
+
/*
* Presence of mandatory attributes ORIGIN and AS_PATH is ensured by above
* conditions. Presence and validity of quasi-mandatory NEXT_HOP attribute
diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c
index 89507f1a..3b28a338 100644
--- a/proto/bgp/bgp.c
+++ b/proto/bgp/bgp.c
@@ -102,6 +102,7 @@
* RFC 8212 - Default EBGP Route Propagation Behavior without Policies
* RFC 8654 - Extended Message Support for BGP
* RFC 9117 - Revised Validation Procedure for BGP Flow Specifications
+ * RFC 9234 - Route Leak Prevention and Detection Using Roles
* draft-ietf-idr-ext-opt-param-07
* draft-uttaro-idr-bgp-persistence-04
* draft-walton-bgp-hostname-capability-02
@@ -1983,6 +1984,12 @@ bgp_postconfig(struct proto_config *CF)
if (internal && cf->rs_client)
cf_error("Only external neighbor can be RS client");
+ if (internal && (cf->local_role != BGP_ROLE_UNDEFINED))
+ cf_error("Local role cannot be set on IBGP sessions");
+
+ if (cf->require_roles && (cf->local_role == BGP_ROLE_UNDEFINED))
+ cf_error("Local role must be set if roles are required");
+
if (!cf->confederation && cf->confederation_member)
cf_error("Confederation ID must be set for member sessions");
@@ -2345,6 +2352,15 @@ bgp_show_afis(int code, char *s, u32 *afis, uint count)
cli_msg(code, b.start);
}
+static const char *
+bgp_format_role_name(u8 role)
+{
+ static const char *bgp_role_names[] = { "provider", "rs_server", "rs_client", "customer", "peer" };
+ if (role == BGP_ROLE_UNDEFINED) return "undefined";
+ if (role < 5) return bgp_role_names[role];
+ return "?";
+}
+
static void
bgp_show_capabilities(struct bgp_proto *p UNUSED, struct bgp_caps *caps)
{
@@ -2473,6 +2489,9 @@ bgp_show_capabilities(struct bgp_proto *p UNUSED, struct bgp_caps *caps)
if (caps->hostname)
cli_msg(-1006, " Hostname: %s", caps->hostname);
+
+ if (caps->role != BGP_ROLE_UNDEFINED)
+ cli_msg(-1006, " Role: %s", bgp_format_role_name(caps->role));
}
static void
diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index 7cd1c27d..fea87304 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -114,6 +114,8 @@ struct bgp_config {
int gr_mode; /* Graceful restart mode (BGP_GR_*) */
int llgr_mode; /* Long-lived graceful restart mode (BGP_LLGR_*) */
int setkey; /* Set MD5 password to system SA/SP database */
+ u8 local_role; /* Set peering role with neighbor [RFC 9234] */
+ int require_roles; /* Require configured roles on both sides */
/* Times below are in seconds */
unsigned gr_time; /* Graceful restart timeout */
unsigned llgr_time; /* Long-lived graceful restart stale time */
@@ -167,6 +169,13 @@ struct bgp_channel_config {
#define BGP_PT_INTERNAL 1
#define BGP_PT_EXTERNAL 2
+#define BGP_ROLE_UNDEFINED 255
+#define BGP_ROLE_PROVIDER 0
+#define BGP_ROLE_RS_SERVER 1
+#define BGP_ROLE_RS_CLIENT 2
+#define BGP_ROLE_CUSTOMER 3
+#define BGP_ROLE_PEER 4
+
#define NH_NO 0
#define NH_ALL 1
#define NH_IBGP 2
@@ -223,6 +232,7 @@ struct bgp_caps {
u8 ext_messages; /* Extended message length, RFC draft */
u8 route_refresh; /* Route refresh capability, RFC 2918 */
u8 enhanced_refresh; /* Enhanced route refresh, RFC 7313 */
+ u8 role; /* BGP role capability, RFC 9234 */
u8 gr_aware; /* Graceful restart capability, RFC 4724 */
u8 gr_flags; /* Graceful restart flags */
@@ -485,6 +495,12 @@ static inline int bgp_cc_is_ipv4(struct bgp_channel_config *c)
static inline int bgp_cc_is_ipv6(struct bgp_channel_config *c)
{ return BGP_AFI(c->afi) == BGP_AFI_IPV6; }
+static inline int bgp_channel_is_role_applicable(struct bgp_channel *c)
+{ return (c->afi == BGP_AF_IPV4 || c->afi == BGP_AF_IPV6); }
+
+static inline int bgp_cc_is_role_applicable(struct bgp_channel_config *c)
+{ return (c->afi == BGP_AF_IPV4 || c->afi == BGP_AF_IPV6); }
+
static inline uint bgp_max_packet_length(struct bgp_conn *conn)
{ return conn->ext_messages ? BGP_MAX_EXT_MSG_LENGTH : BGP_MAX_MESSAGE_LENGTH; }
@@ -660,6 +676,7 @@ void bgp_update_next_hop(struct bgp_export_state *s, eattr *a, ea_list **to);
#define BA_AS4_AGGREGATOR 0x12 /* RFC 6793 */
#define BA_AIGP 0x1a /* RFC 7311 */
#define BA_LARGE_COMMUNITY 0x20 /* RFC 8092 */
+#define BA_ONLY_TO_CUSTOMER 0x23 /* RFC 9234 */
/* Bird's private internal BGP attributes */
#define BA_MPLS_LABEL_STACK 0xfe /* MPLS label stack transfer attribute */
diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y
index 241aa7c2..a00aa156 100644
--- a/proto/bgp/config.Y
+++ b/proto/bgp/config.Y
@@ -31,7 +31,8 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY, KEEPALIVE,
STRICT, BIND, CONFEDERATION, MEMBER, MULTICAST, FLOW4, FLOW6, LONG,
LIVED, STALE, IMPORT, IBGP, EBGP, MANDATORY, INTERNAL, EXTERNAL, SETS,
DYNAMIC, RANGE, NAME, DIGITS, BGP_AIGP, AIGP, ORIGINATE, COST, ENFORCE,
- FIRST, FREE, VALIDATE, BASE)
+ FIRST, FREE, VALIDATE, BASE, ROLE, ROLES, PEER, PROVIDER, CUSTOMER,
+ RS_SERVER, RS_CLIENT, REQUIRE)
%type <i> bgp_nh
%type <i32> bgp_afi
@@ -40,7 +41,7 @@ CF_KEYWORDS(CEASE, PREFIX, LIMIT, HIT, ADMINISTRATIVE, SHUTDOWN, RESET, PEER,
CONFIGURATION, CHANGE, DECONFIGURED, CONNECTION, REJECTED, COLLISION,
OUT, OF, RESOURCES)
-%type<i> bgp_cease_mask bgp_cease_list bgp_cease_flag
+%type<i> bgp_cease_mask bgp_cease_list bgp_cease_flag bgp_role_name
CF_GRAMMAR
@@ -72,6 +73,7 @@ bgp_proto_start: proto_start BGP {
BGP_CFG->llgr_mode = -1;
BGP_CFG->llgr_time = 3600;
BGP_CFG->setkey = 1;
+ BGP_CFG->local_role = BGP_ROLE_UNDEFINED;
BGP_CFG->dynamic_name = "dynbgp";
BGP_CFG->check_link = -1;
}
@@ -114,6 +116,14 @@ bgp_cease_flag:
| OUT OF RESOURCES { $$ = 1 << 8; }
;
+bgp_role_name:
+ PEER { $$ = BGP_ROLE_PEER; }
+ | PROVIDER { $$ = BGP_ROLE_PROVIDER; }
+ | CUSTOMER { $$ = BGP_ROLE_CUSTOMER; }
+ | RS_SERVER { $$ = BGP_ROLE_RS_SERVER; }
+ | RS_CLIENT { $$ = BGP_ROLE_RS_CLIENT; }
+ ;
+
bgp_proto:
bgp_proto_start proto_name '{'
| bgp_proto proto_item ';'
@@ -197,6 +207,8 @@ bgp_proto:
| bgp_proto BFD GRACEFUL ';' { init_bfd_opts(&BGP_CFG->bfd); BGP_CFG->bfd->mode = BGP_BFD_GRACEFUL; }
| bgp_proto BFD { open_bfd_opts(&BGP_CFG->bfd); } bfd_opts { close_bfd_opts(); } ';'
| bgp_proto ENFORCE FIRST AS bool ';' { BGP_CFG->enforce_first_as = $5; }
+ | bgp_proto LOCAL ROLE bgp_role_name ';' { BGP_CFG->local_role = $4; }
+ | bgp_proto REQUIRE ROLES bool ';' { BGP_CFG->require_roles = $4; }
;
bgp_afi:
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index f13625e2..54423a1a 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -238,6 +238,7 @@ bgp_prepare_capabilities(struct bgp_conn *conn)
caps->ext_messages = p->cf->enable_extended_messages;
caps->route_refresh = p->cf->enable_refresh;
caps->enhanced_refresh = p->cf->enable_refresh;
+ caps->role = p->cf->local_role;
if (caps->as4_support)
caps->as4_number = p->public_as;
@@ -350,6 +351,13 @@ bgp_write_capabilities(struct bgp_conn *conn, byte *buf)
*buf++ = 0; /* Capability data length */
}
+ if (caps->role != BGP_ROLE_UNDEFINED)
+ {
+ *buf++ = 9; /* Capability 9: Announce chosen BGP role */
+ *buf++ = 1; /* Capability data length */
+ *buf++ = caps->role;
+ }
+
if (caps->gr_aware)
{
*buf++ = 64; /* Capability 64: Support for graceful restart */
@@ -449,11 +457,15 @@ bgp_read_capabilities(struct bgp_conn *conn, byte *pos, int len)
struct bgp_proto *p = conn->bgp;
struct bgp_caps *caps;
struct bgp_af_caps *ac;
+ uint err_subcode = 0;
int i, cl;
u32 af;
if (!conn->remote_caps)
+ {
caps = mb_allocz(p->p.pool, sizeof(struct bgp_caps) + sizeof(struct bgp_af_caps));
+ caps->role = BGP_ROLE_UNDEFINED;
+ }
else
{
caps = conn->remote_caps;
@@ -513,6 +525,21 @@ bgp_read_capabilities(struct bgp_conn *conn, byte *pos, int len)
caps->ext_messages = 1;
break;
+ case 9: /* BGP role capability, RFC 9234 */
+ if (cl != 1)
+ goto err;
+
+ /* Reserved value */
+ if (pos[2] == BGP_ROLE_UNDEFINED)
+ { err_subcode = 11; goto err; }
+
+ /* Multiple inconsistent values */
+ if ((caps->role != BGP_ROLE_UNDEFINED) && (caps->role != pos[2]))
+ { err_subcode = 11; goto err; }
+
+ caps->role = pos[2];
+ break;
+
case 64: /* Graceful restart capability, RFC 4724 */
if (cl % 4 != 2)
goto err;
@@ -638,7 +665,7 @@ bgp_read_capabilities(struct bgp_conn *conn, byte *pos, int len)
err:
mb_free(caps);
- bgp_error(conn, 2, 0, NULL, 0);
+ bgp_error(conn, 2, err_subcode, NULL, 0);
return -1;
}
@@ -854,6 +881,22 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, uint len)
conn->received_as = asn;
}
+ /* RFC 9234 4.2 - check role agreement */
+ u8 local_role = p->cf->local_role;
+ u8 neigh_role = caps->role;
+
+ if ((local_role != BGP_ROLE_UNDEFINED) &&
+ (neigh_role != BGP_ROLE_UNDEFINED) &&
+ !((local_role == BGP_ROLE_PEER && neigh_role == BGP_ROLE_PEER) ||
+ (local_role == BGP_ROLE_CUSTOMER && neigh_role == BGP_ROLE_PROVIDER) ||
+ (local_role == BGP_ROLE_PROVIDER && neigh_role == BGP_ROLE_CUSTOMER) ||
+ (local_role == BGP_ROLE_RS_CLIENT && neigh_role == BGP_ROLE_RS_SERVER) ||
+ (local_role == BGP_ROLE_RS_SERVER && neigh_role == BGP_ROLE_RS_CLIENT)))
+ { bgp_error(conn, 2, 11, NULL, 0); return; }
+
+ if ((p->cf->require_roles) && (neigh_role == BGP_ROLE_UNDEFINED))
+ { bgp_error(conn, 2, 11, NULL, 0); return; }
+
/* Check the other connection */
other = (conn == &p->outgoing_conn) ? &p->incoming_conn : &p->outgoing_conn;
switch (other->state)
@@ -2984,6 +3027,7 @@ static struct {
{ 2, 6, "Unacceptable hold time" },
{ 2, 7, "Required capability missing" }, /* [RFC5492] */
{ 2, 8, "No supported AFI/SAFI" }, /* This error msg is nonstandard */
+ { 2,11, "Role mismatch" }, /* From Open Policy, RFC 9234 */
{ 3, 0, "Invalid UPDATE message" },
{ 3, 1, "Malformed attribute list" },
{ 3, 2, "Unrecognized well-known attribute" },
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 14:32:55 +0000