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-rw-r--r--doc/bird.sgml29
-rw-r--r--proto/bgp/attrs.c69
-rw-r--r--proto/bgp/bgp.c22
-rw-r--r--proto/bgp/bgp.h17
-rw-r--r--proto/bgp/config.Y18
-rw-r--r--proto/bgp/packets.c46
-rw-r--r--sysdep/cf/README1
-rw-r--r--sysdep/cf/linux.h1
-rw-r--r--sysdep/linux/netlink.c326
-rw-r--r--sysdep/unix/krt.c72
-rw-r--r--sysdep/unix/krt.h4
11 files changed, 342 insertions, 263 deletions
diff --git a/doc/bird.sgml b/doc/bird.sgml
index 4b593ef6..648b4a1c 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -2377,6 +2377,7 @@ avoid routing loops.
<item> <rfc id="8203"> - BGP Administrative Shutdown Communication
<item> <rfc id="8212"> - Default EBGP Route Propagation Behavior without Policies
<item> <rfc id="9117"> - Revised Validation Procedure for BGP Flow Specifications
+<item> <rfc id="9234"> - Route Leak Prevention and Detection Using Roles
</itemize>
<sect1>Route selection rules
@@ -2817,6 +2818,29 @@ using the following configuration parameters:
protocol itself (for example, if a route is received through eBGP and
therefore does not have such attribute). Default: 100 (0 in pre-1.2.0
versions of BIRD).
+
+ <tag><label id="bgp-local-role">local role <m/role-name/</tag>
+ BGP roles are a mechanism for route leak prevention and automatic route
+ filtering based on common BGP topology relationships. They are defined
+ in <rfc id="9234">. Instead of manually configuring filters and
+ communities, automatic filtering is done with the help of the OTC
+ attribute - a flag for routes that should be sent only to customers.
+ The same attribute is also used to automatically detect and filter route
+ leaks created by third parties.
+
+ This option is valid for EBGP sessions, but it is not recommended to be
+ used within AS confederations (which would require manual filtering of
+ <cf/bgp_otc/ attribute on confederation boundaries).
+
+ Possible <cf><m/role-name/</cf> values are: <cf/provider/,
+ <cf/rs_server/, <cf/rs_client/, <cf/customer/ and <cf/peer/.
+ Default: No local role assigned.
+
+ <tag><label id="bgp-require-roles">require roles <m/switch/</tag>
+ If this option is set, the BGP roles must be defined on both sides,
+ otherwise the session will not be established. This behavior is defined
+ in <rfc id="9234"> as "strict mode" and is used to enforce corresponding
+ configuration at your conterpart side. Default: disabled.
</descrip>
<sect1>Channel configuration
@@ -3124,6 +3148,11 @@ some of them (marked with `<tt/O/') are optional.
This attribute contains accumulated IGP metric, which is a total
distance to the destination through multiple autonomous systems.
Currently, the attribute is not accessible from filters.
+
+ <tag><label id="bgp-otc">int bgp_otc [O]</tag>
+ This attribute is defined in <rfc id="9234">. OTC is a flag that marks
+ routes that should be sent only to customers. If <ref id="bgp-role"
+ name="local Role"> is configured it set automatically.
</descrip>
<sect1>Example
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 2f6cf640..a56aeb19 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -903,6 +903,18 @@ 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)
{
@@ -1116,6 +1128,13 @@ 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,
@@ -1452,6 +1471,29 @@ 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);
+ }
}
@@ -1681,6 +1723,7 @@ bgp_preexport(struct channel *C, rte *e)
struct proto *SRC = e->src->proto;
struct bgp_proto *p = (struct bgp_proto *) C->proto;
struct bgp_proto *src = (SRC->proto == &proto_bgp) ? (struct bgp_proto *) SRC : NULL;
+ struct bgp_channel *c = (struct bgp_channel *) C;
/* Reject our routes */
if (src == p)
@@ -1708,11 +1751,11 @@ bgp_preexport(struct channel *C, rte *e)
}
/* 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))
@@ -1731,6 +1774,16 @@ bgp_preexport(struct channel *C, rte *e)
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;
}
@@ -1840,6 +1893,16 @@ 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 2b97cc4b..f07fcc16 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
@@ -1963,6 +1964,15 @@ 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 (interior && (cf->local_role != BGP_ROLE_UNDEFINED))
+ log(L_WARN "BGP roles are not recommended to be used within AS confederations");
+
+ 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");
@@ -2325,6 +2335,15 @@ 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 < ARRAY_SIZE(bgp_role_names)) return bgp_role_names[role];
+ return "?";
+}
+
static void
bgp_show_capabilities(struct bgp_proto *p UNUSED, struct bgp_caps *caps)
{
@@ -2453,6 +2472,9 @@ 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 13102857..15a759fb 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -113,6 +113,8 @@ 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 */
@@ -166,6 +168,13 @@ 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
@@ -226,6 +235,7 @@ 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 */
@@ -487,6 +497,12 @@ 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; }
@@ -658,6 +674,7 @@ 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..cb410a5e 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, BGP_OTC)
%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:
@@ -343,6 +355,8 @@ dynamic_attr: BGP_AIGP
{ $$ = f_new_dynamic_attr(EAF_TYPE_OPAQUE, T_ENUM_EMPTY, EA_CODE(PROTOCOL_BGP, BA_AIGP)); } ;
dynamic_attr: BGP_LARGE_COMMUNITY
{ $$ = f_new_dynamic_attr(EAF_TYPE_LC_SET, T_LCLIST, EA_CODE(PROTOCOL_BGP, BA_LARGE_COMMUNITY)); } ;
+dynamic_attr: BGP_OTC
+ { $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_CODE(PROTOCOL_BGP, BA_ONLY_TO_CUSTOMER)); } ;
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index a805cdf0..3aa62c39 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)
@@ -2985,6 +3028,7 @@ 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" },
diff --git a/sysdep/cf/README b/sysdep/cf/README
index 9a7a4afa..68078bbe 100644
--- a/sysdep/cf/README
+++ b/sysdep/cf/README
@@ -4,7 +4,6 @@ Available configuration variables:
CONFIG_AUTO_ROUTES Device routes are added automagically by the kernel
CONFIG_SELF_CONSCIOUS We're able to recognize whether route was installed by us
CONFIG_MULTIPLE_TABLES The kernel supports multiple routing tables
-CONFIG_ALL_TABLES_AT_ONCE Kernel scanner wants to process all tables at once
CONFIG_SINGLE_ROUTE There is only one route per network
CONFIG_MC_PROPER_SRC Multicast packets have source address according to socket saddr field
diff --git a/sysdep/cf/linux.h b/sysdep/cf/linux.h
index 047d3764..c640bef4 100644
--- a/sysdep/cf/linux.h
+++ b/sysdep/cf/linux.h
@@ -9,7 +9,6 @@
#define CONFIG_AUTO_ROUTES
#define CONFIG_SELF_CONSCIOUS
#define CONFIG_MULTIPLE_TABLES
-#define CONFIG_ALL_TABLES_AT_ONCE
#define CONFIG_IP6_SADR_KERNEL
#define CONFIG_MC_PROPER_SRC
diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index e103c8ef..342b746c 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -74,51 +74,16 @@
#endif
#define krt_ipv4(p) ((p)->af == AF_INET)
-#define krt_ecmp6(p) ((p)->af == AF_INET6)
const int rt_default_ecmp = 16;
-/*
- * Structure nl_parse_state keeps state of received route processing. Ideally,
- * we could just independently parse received Netlink messages and immediately
- * propagate received routes to the rest of BIRD, but older Linux kernel (before
- * version 4.11) represents and announces IPv6 ECMP routes not as one route with
- * multiple next hops (like RTA_MULTIPATH in IPv4 ECMP), but as a sequence of
- * routes with the same prefix. More recent kernels work as with IPv4.
- *
- * Therefore, BIRD keeps currently processed route in nl_parse_state structure
- * and postpones its propagation until we expect it to be final; i.e., when
- * non-matching route is received or when the scan ends. When another matching
- * route is received, it is merged with the already processed route to form an
- * ECMP route. Note that merging is done only for IPv6 (merge == 1), but the
- * postponing is done in both cases (for simplicity). All IPv4 routes or IPv6
- * routes with RTA_MULTIPATH set are just considered non-matching.
- *
- * This is ignored for asynchronous notifications (every notification is handled
- * as a separate route). It is not an issue for our routes, as we ignore such
- * notifications anyways. But importing alien IPv6 ECMP routes does not work
- * properly with older kernels.
- *
- * Whatever the kernel version is, IPv6 ECMP routes are sent as multiple routes
- * for the same prefix.
- */
-
struct nl_parse_state
{
+ struct krt_proto *proto;
struct linpool *pool;
int scan;
- int merge;
- net *net;
- rta *attrs;
- struct krt_proto *proto;
- s8 new;
- s8 krt_src;
- u8 krt_type;
- u8 krt_proto;
- u32 krt_metric;
-
- u32 rta_flow; /* Used during parsing */
+ u32 rta_flow;
};
/*
@@ -161,16 +126,13 @@ nl_open_sock(struct nl_sock *nl)
}
}
-static void
+static int
nl_set_strict_dump(struct nl_sock *nl UNUSED, int strict UNUSED)
{
- /*
- * Strict checking is not necessary, it improves behavior on newer kernels.
- * If it is not available (missing SOL_NETLINK compile-time, or ENOPROTOOPT
- * run-time), we can just ignore it.
- */
#ifdef SOL_NETLINK
- setsockopt(nl->fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &strict, sizeof(strict));
+ return setsockopt(nl->fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &strict, sizeof(strict));
+#else
+ return -1;
#endif
}
@@ -198,10 +160,17 @@ nl_cfg_rx_buffer_size(struct config *cfg)
static void
nl_open(void)
{
+ if ((nl_scan.fd >= 0) && (nl_req.fd >= 0))
+ return;
+
nl_open_sock(&nl_scan);
nl_open_sock(&nl_req);
- nl_set_strict_dump(&nl_scan, 1);
+ if (nl_set_strict_dump(&nl_scan, 1) < 0)
+ {
+ log(L_WARN "KRT: Netlink strict checking failed, will scan all tables at once");
+ krt_use_shared_scan();
+ }
}
static void
@@ -256,11 +225,13 @@ nl_request_dump_addr(int af)
}
static void
-nl_request_dump_route(int af)
+nl_request_dump_route(int af, int table_id)
{
struct {
struct nlmsghdr nh;
struct rtmsg rtm;
+ struct rtattr rta;
+ u32 table_id;
} req = {
.nh.nlmsg_type = RTM_GETROUTE,
.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)),
@@ -269,7 +240,17 @@ nl_request_dump_route(int af)
.rtm.rtm_family = af,
};
- send(nl_scan.fd, &req, sizeof(req), 0);
+ if (table_id < 256)
+ req.rtm.rtm_table = table_id;
+ else
+ {
+ req.rta.rta_type = RTA_TABLE;
+ req.rta.rta_len = RTA_LENGTH(4);
+ req.table_id = table_id;
+ req.nh.nlmsg_len = NLMSG_ALIGN(req.nh.nlmsg_len) + req.rta.rta_len;
+ }
+
+ send(nl_scan.fd, &req, req.nh.nlmsg_len, 0);
nl_scan.last_hdr = NULL;
}
@@ -1325,7 +1306,7 @@ nh_bufsize(struct nexthop *nh)
}
static int
-nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
+nl_send_route(struct krt_proto *p, rte *e, int op)
{
eattr *ea;
net *net = e->net;
@@ -1407,15 +1388,17 @@ nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
/* For route delete, we do not specify remaining route attributes */
if (op == NL_OP_DELETE)
- goto dest;
+ goto done;
/* Default scope is LINK for device routes, UNIVERSE otherwise */
if (p->af == AF_MPLS)
r->r.rtm_scope = RT_SCOPE_UNIVERSE;
else if (ea = ea_find(eattrs, EA_KRT_SCOPE))
r->r.rtm_scope = ea->u.data;
+ else if (a->dest == RTD_UNICAST && ipa_zero(a->nh.gw))
+ r->r.rtm_scope = RT_SCOPE_LINK;
else
- r->r.rtm_scope = (dest == RTD_UNICAST && ipa_zero(nh->gw)) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE;
+ r->r.rtm_scope = RT_SCOPE_UNIVERSE;
if (ea = ea_find(eattrs, EA_KRT_PREFSRC))
nl_add_attr_ipa(&r->h, rsize, RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data);
@@ -1438,13 +1421,12 @@ nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
if (metrics[0])
nl_add_metrics(&r->h, rsize, metrics, KRT_METRICS_MAX);
-
-dest:
- switch (dest)
+ switch (a->dest)
{
case RTD_UNICAST:
r->r.rtm_type = RTN_UNICAST;
- if (nh->next && !krt_ecmp6(p))
+ struct nexthop *nh = &(a->nh);
+ if (nh->next)
nl_add_multipath(&r->h, rsize, nh, p->af, eattrs);
else
{
@@ -1470,82 +1452,53 @@ dest:
bug("krt_capable inconsistent with nl_send_route");
}
+done:
/* Ignore missing for DELETE */
return nl_exchange(&r->h, (op == NL_OP_DELETE));
}
static inline int
-nl_add_rte(struct krt_proto *p, rte *e)
+nl_allow_replace(struct krt_proto *p, rte *new)
{
- rta *a = e->attrs;
- int err = 0;
-
- if (krt_ecmp6(p) && a->nh.next)
- {
- struct nexthop *nh = &(a->nh);
-
- err = nl_send_route(p, e, NL_OP_ADD, RTD_UNICAST, nh);
- if (err < 0)
- return err;
-
- for (nh = nh->next; nh; nh = nh->next)
- err += nl_send_route(p, e, NL_OP_APPEND, RTD_UNICAST, nh);
-
- return err;
- }
-
- return nl_send_route(p, e, NL_OP_ADD, a->dest, &(a->nh));
-}
-
-static inline int
-nl_delete_rte(struct krt_proto *p, rte *e)
-{
- int err = 0;
-
- /* For IPv6, we just repeatedly request DELETE until we get error */
- do
- err = nl_send_route(p, e, NL_OP_DELETE, RTD_NONE, NULL);
- while (krt_ecmp6(p) && !err);
+ /*
+ * We use NL_OP_REPLACE for IPv4, it has an issue with not checking for
+ * matching rtm_protocol, but that is OK when dedicated priority is used.
+ *
+ * For IPv6, the NL_OP_REPLACE is still broken even in Linux 4.19 LTS
+ * (although it seems to be fixed in Linux 5.10 LTS) for sequence:
+ *
+ * ip route add 2001:db8::/32 via fe80::1 dev eth0
+ * ip route replace 2001:db8::/32 dev eth0
+ *
+ * (it ends with two routes instead of replacing the first by the second one)
+ *
+ * Replacing with direct and special type (e.g. unreachable) routes does not
+ * work, but replacing with regular routes work reliably
+ */
- return err;
-}
+ if (krt_ipv4(p))
+ return 1;
-static inline int
-nl_replace_rte(struct krt_proto *p, rte *e)
-{
- rta *a = e->attrs;
- return nl_send_route(p, e, NL_OP_REPLACE, a->dest, &(a->nh));
+ rta *a = new->attrs;
+ return (a->dest == RTD_UNICAST) && ipa_nonzero(a->nh.gw);
}
-
void
krt_replace_rte(struct krt_proto *p, net *n UNUSED, rte *new, rte *old)
{
int err = 0;
- /*
- * We use NL_OP_REPLACE for IPv4, it has an issue with not checking for
- * matching rtm_protocol, but that is OK when dedicated priority is used.
- *
- * We do not use NL_OP_REPLACE for IPv6, as it has broken semantics for ECMP
- * and with some kernel versions ECMP replace crashes kernel. Would need more
- * testing and checks for kernel versions.
- *
- * For IPv6, we use NL_OP_DELETE and then NL_OP_ADD. We also do not trust the
- * old route value, so we do not try to optimize IPv6 ECMP reconfigurations.
- */
-
- if (krt_ipv4(p) && old && new)
+ if (old && new && nl_allow_replace(p, new))
{
- err = nl_replace_rte(p, new);
+ err = nl_send_route(p, new, NL_OP_REPLACE);
}
else
{
if (old)
- nl_delete_rte(p, old);
+ nl_send_route(p, old, NL_OP_DELETE);
if (new)
- err = nl_add_rte(p, new);
+ err = nl_send_route(p, new, NL_OP_ADD);
}
if (new)
@@ -1557,71 +1510,6 @@ krt_replace_rte(struct krt_proto *p, net *n UNUSED, rte *new, rte *old)
}
}
-static int
-nl_mergable_route(struct nl_parse_state *s, net *net, struct krt_proto *p, uint priority, uint krt_type, uint rtm_family)
-{
- /* Route merging is used for IPv6 scans */
- if (!s->scan || (rtm_family != AF_INET6))
- return 0;
-
- /* Saved and new route must have same network, proto/table, and priority */
- if ((s->net != net) || (s->proto != p) || (s->krt_metric != priority))
- return 0;
-
- /* Both must be regular unicast routes */
- if ((s->krt_type != RTN_UNICAST) || (krt_type != RTN_UNICAST))
- return 0;
-
- return 1;
-}
-
-static void
-nl_announce_route(struct nl_parse_state *s)
-{
- rte *e = rte_get_temp(s->attrs, s->proto->p.main_source);
- e->net = s->net;
-
- ea_list *ea = alloca(sizeof(ea_list) + 2 * sizeof(eattr));
- *ea = (ea_list) { .count = 2, .next = e->attrs->eattrs };
- e->attrs->eattrs = ea;
-
- ea->attrs[0] = (eattr) {
- .id = EA_KRT_SOURCE,
- .type = EAF_TYPE_INT,
- .u.data = s->krt_proto,
- };
- ea->attrs[1] = (eattr) {
- .id = EA_KRT_METRIC,
- .type = EAF_TYPE_INT,
- .u.data = s->krt_metric,
- };
-
- if (s->scan)
- krt_got_route(s->proto, e, s->krt_src);
- else
- krt_got_route_async(s->proto, e, s->new, s->krt_src);
-
- s->net = NULL;
- s->attrs = NULL;
- s->proto = NULL;
- lp_flush(s->pool);
-}
-
-static inline void
-nl_parse_begin(struct nl_parse_state *s, int scan)
-{
- memset(s, 0, sizeof (struct nl_parse_state));
- s->pool = nl_linpool;
- s->scan = scan;
-}
-
-static inline void
-nl_parse_end(struct nl_parse_state *s)
-{
- if (s->net)
- nl_announce_route(s);
-}
-
#define SKIP0(ARG, ...) do { DBG("KRT: Ignoring route - " ARG, ##__VA_ARGS__); return; } while(0)
#define SKIP(ARG, ...) do { DBG("KRT: Ignoring route %N - " ARG, &dst, ##__VA_ARGS__); return; } while(0)
@@ -1759,13 +1647,29 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
net *net = net_get(p->p.main_channel->table, n);
- if (s->net && !nl_mergable_route(s, net, p, priority, i->rtm_type, i->rtm_family))
- nl_announce_route(s);
-
rta *ra = lp_allocz(s->pool, RTA_MAX_SIZE);
ra->source = RTS_INHERIT;
ra->scope = SCOPE_UNIVERSE;
+ {
+ ea_list *ea = lp_alloc(s->pool, sizeof(ea_list) + 2 * sizeof(eattr));
+ *ea = (ea_list) { .flags = EALF_SORTED, .count = 2 };
+ ea->next = ra->eattrs;
+ ra->eattrs = ea;
+
+ ea->attrs[0] = (eattr) {
+ .id = EA_KRT_SOURCE,
+ .type = EAF_TYPE_INT,
+ .u.data = i->rtm_protocol
+ };
+
+ ea->attrs[1] = (eattr) {
+ .id = EA_KRT_METRIC,
+ .type = EAF_TYPE_INT,
+ .u.data = priority,
+ };
+ }
+
if (a[RTA_FLOW])
s->rta_flow = rta_get_u32(a[RTA_FLOW]);
else
@@ -1942,60 +1846,40 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
}
}
- /*
- * Ideally, now we would send the received route to the rest of kernel code.
- * But IPv6 ECMP routes before 4.11 are sent as a sequence of routes, so we
- * postpone it and merge next hops until the end of the sequence. Note that
- * when doing merging of next hops, we expect the new route to be unipath.
- * Otherwise, we ignore additional next hops in nexthop_insert().
- */
+ rte *e = rte_get_temp(ra, p->p.main_source);
+ e->net = net;
- if (!s->net)
- {
- /* Store the new route */
- s->net = net;
- s->attrs = ra;
- s->proto = p;
- s->new = new;
- s->krt_src = krt_src;
- s->krt_type = i->rtm_type;
- s->krt_proto = i->rtm_protocol;
- s->krt_metric = priority;
- }
+ if (s->scan)
+ krt_got_route(p, e, krt_src);
else
- {
- /* Merge next hops with the stored route */
- rta *oa = s->attrs;
+ krt_got_route_async(p, e, new, krt_src);
- struct nexthop *nhs = &oa->nh;
- nexthop_insert(&nhs, &ra->nh);
-
- /* Perhaps new nexthop is inserted at the first position */
- if (nhs == &ra->nh)
- {
- /* Swap rtas */
- s->attrs = ra;
-
- /* Keep old eattrs */
- ra->eattrs = oa->eattrs;
- }
- }
+ lp_flush(s->pool);
}
void
-krt_do_scan(struct krt_proto *p UNUSED) /* CONFIG_ALL_TABLES_AT_ONCE => p is NULL */
+krt_do_scan(struct krt_proto *p)
{
- struct nlmsghdr *h;
- struct nl_parse_state s;
+ struct nl_parse_state s = {
+ .proto = p,
+ .pool = nl_linpool,
+ .scan = 1,
+ };
+
+ /* Table-specific scan or shared scan */
+ if (p)
+ nl_request_dump_route(p->af, krt_table_id(p));
+ else
+ nl_request_dump_route(AF_UNSPEC, 0);
- nl_parse_begin(&s, 1);
- nl_request_dump_route(AF_UNSPEC);
+ struct nlmsghdr *h;
while (h = nl_get_scan())
+ {
if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE)
nl_parse_route(&s, h);
else
log(L_DEBUG "nl_scan_fire: Unknown packet received (type=%d)", h->nlmsg_type);
- nl_parse_end(&s);
+ }
}
/*
@@ -2010,16 +1894,18 @@ static struct config *nl_last_config; /* For tracking changes to nl_async_bufsiz
static void
nl_async_msg(struct nlmsghdr *h)
{
- struct nl_parse_state s;
+ struct nl_parse_state s = {
+ .proto = NULL,
+ .pool = nl_linpool,
+ .scan = 0,
+ };
switch (h->nlmsg_type)
{
case RTM_NEWROUTE:
case RTM_DELROUTE:
DBG("KRT: Received async route notification (%d)\n", h->nlmsg_type);
- nl_parse_begin(&s, 0);
nl_parse_route(&s, h);
- nl_parse_end(&s);
break;
case RTM_NEWLINK:
case RTM_DELLINK:
diff --git a/sysdep/unix/krt.c b/sysdep/unix/krt.c
index be547a93..c4a3a4a8 100644
--- a/sysdep/unix/krt.c
+++ b/sysdep/unix/krt.c
@@ -785,18 +785,17 @@ krt_got_route_async(struct krt_proto *p, rte *e, int new, s8 src)
rte_free(e);
}
+
/*
* Periodic scanning
*/
-
-#ifdef CONFIG_ALL_TABLES_AT_ONCE
-
-static timer *krt_scan_timer;
-static int krt_scan_count;
+static timer *krt_scan_all_timer;
+static int krt_scan_all_count;
+static _Bool krt_scan_all_tables;
static void
-krt_scan(timer *t UNUSED)
+krt_scan_all(timer *t UNUSED)
{
struct krt_proto *p;
node *n;
@@ -817,35 +816,42 @@ krt_scan(timer *t UNUSED)
}
static void
-krt_scan_timer_start(struct krt_proto *p)
+krt_scan_all_timer_start(struct krt_proto *p)
{
- if (!krt_scan_count)
- krt_scan_timer = tm_new_init(krt_pool, krt_scan, NULL, KRT_CF->scan_time, 0);
+ if (!krt_scan_all_count)
+ krt_scan_all_timer = tm_new_init(krt_pool, krt_scan_all, NULL, KRT_CF->scan_time, 0);
- krt_scan_count++;
+ krt_scan_all_count++;
- tm_start(krt_scan_timer, 1 S);
+ tm_start(krt_scan_all_timer, 1 S);
}
static void
-krt_scan_timer_stop(struct krt_proto *p UNUSED)
+krt_scan_all_timer_stop(void)
{
- krt_scan_count--;
+ ASSERT(krt_scan_all_count > 0);
+
+ krt_scan_all_count--;
- if (!krt_scan_count)
+ if (!krt_scan_all_count)
{
- rfree(krt_scan_timer);
- krt_scan_timer = NULL;
+ rfree(krt_scan_all_timer);
+ krt_scan_all_timer = NULL;
}
}
static void
-krt_scan_timer_kick(struct krt_proto *p UNUSED)
+krt_scan_all_timer_kick(void)
{
- tm_start(krt_scan_timer, 0);
+ tm_start(krt_scan_all_timer, 0);
+}
+
+void
+krt_use_shared_scan(void)
+{
+ krt_scan_all_tables = 1;
}
-#else
static void
krt_scan(timer *t)
@@ -863,26 +869,33 @@ krt_scan(timer *t)
static void
krt_scan_timer_start(struct krt_proto *p)
{
- p->scan_timer = tm_new_init(p->p.pool, krt_scan, p, KRT_CF->scan_time, 0);
- tm_start(p->scan_timer, 1 S);
+ if (krt_scan_all_tables)
+ krt_scan_all_timer_start(p);
+ else
+ {
+ p->scan_timer = tm_new_init(p->p.pool, krt_scan, p, KRT_CF->scan_time, 0);
+ tm_start(p->scan_timer, 1 S);
+ }
}
static void
krt_scan_timer_stop(struct krt_proto *p)
{
- tm_stop(p->scan_timer);
+ if (krt_scan_all_tables)
+ krt_scan_all_timer_stop();
+ else
+ tm_stop(p->scan_timer);
}
static void
krt_scan_timer_kick(struct krt_proto *p)
{
- tm_start(p->scan_timer, 0);
+ if (krt_scan_all_tables)
+ krt_scan_all_timer_kick();
+ else
+ tm_start(p->scan_timer, 0);
}
-#endif
-
-
-
/*
* Updates
@@ -992,11 +1005,6 @@ krt_postconfig(struct proto_config *CF)
if (! proto_cf_main_channel(CF))
cf_error("Channel not specified");
-#ifdef CONFIG_ALL_TABLES_AT_ONCE
- if (krt_cf->scan_time != cf->scan_time)
- cf_error("All kernel syncers must use the same table scan interval");
-#endif
-
struct channel_config *cc = proto_cf_main_channel(CF);
struct rtable_config *tab = cc->table;
if (tab->krt_attached)
diff --git a/sysdep/unix/krt.h b/sysdep/unix/krt.h
index 20858cd7..18a206e6 100644
--- a/sysdep/unix/krt.h
+++ b/sysdep/unix/krt.h
@@ -55,10 +55,7 @@ struct krt_proto {
struct rtable *krt_table; /* Internal table of inherited routes */
#endif
-#ifndef CONFIG_ALL_TABLES_AT_ONCE
timer *scan_timer;
-#endif
-
struct bmap sync_map; /* Keeps track which exported routes were successfully written to kernel */
struct bmap seen_map; /* Routes seen during last periodic scan */
node krt_node; /* Node in krt_proto_list */
@@ -79,6 +76,7 @@ extern pool *krt_pool;
struct proto_config * kif_init_config(int class);
void kif_request_scan(void);
+void krt_use_shared_scan(void);
void krt_got_route(struct krt_proto *p, struct rte *e, s8 src);
void krt_got_route_async(struct krt_proto *p, struct rte *e, int new, s8 src);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 12:23:09 +0000