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OSPF: Opaque LSAs and Router Information LSA

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Add support for OSPFv2 Opaque LSAs (RFC 5250) and for Router Information
LSA (RFC 7770). The second part is here mainly for testing opaque LSAs.
This commit is contained in:
Ondrej Zajicek (work) 2019-01-24 22:34:33 +01:00
parent 3e60932a28
commit 5a50a98980
9 changed files with 224 additions and 40 deletions
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7
lib/birdlib.h
View file

@ -56,6 +56,13 @@ static inline int u64_cmp(u64 i1, u64 i2)
#define BIT32_CLR(b,p) ((b)[(p)/32] &= ~BIT32_VAL(p))
#define BIT32_ZERO(b,l) memset((b), 0, (l)/8)
/* The same, but counting bits from MSB */
#define BIT32R_VAL(p) ((((u32) 1) << 31) >> ((p) % 32))
#define BIT32R_TEST(b,p) ((b)[(p)/32] & BIT32R_VAL(p))
#define BIT32R_SET(b,p) ((b)[(p)/32] |= BIT32R_VAL(p))
#define BIT32R_CLR(b,p) ((b)[(p)/32] &= ~BIT32R_VAL(p))
#define BIT32R_ZERO(b,l) memset((b), 0, (l)/8)
#ifndef NULL
#define NULL ((void *) 0)
#endif

5
proto/ospf/dbdes.c
View file

@ -127,7 +127,7 @@ ospf_prepare_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
struct ospf_dbdes2_packet *ps = (void *) pkt;
ps->iface_mtu = htons(iface_mtu);
ps->options = ifa->oa->options;
ps->options = ifa->oa->options | OPT_O;
ps->imms = 0; /* Will be set later */
ps->ddseq = htonl(n->dds);
length = sizeof(struct ospf_dbdes2_packet);
@ -162,7 +162,8 @@ ospf_prepare_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
}
if ((en->lsa.age < LSA_MAXAGE) &&
lsa_flooding_allowed(en->lsa_type, en->domain, ifa))
lsa_flooding_allowed(en->lsa_type, en->domain, ifa) &&
lsa_is_acceptable(en->lsa_type, n, p))
{
lsa_hton_hdr(&(en->lsa), lsas + i);
i++;

95
proto/ospf/lsalib.c
View file

@ -91,6 +91,30 @@ lsa_flooding_allowed(u32 type, u32 domain, struct ospf_iface *ifa)
}
}
int
lsa_is_acceptable(u32 type, struct ospf_neighbor *n, struct ospf_proto *p)
{
if (ospf_is_v2(p))
{
if (type == LSA_T_NSSA)
return !!(n->options & OPT_N);
if (lsa_is_opaque(type))
return !!(n->options & OPT_O);
return 1;
}
else
{
/*
* There should be check whether receiving router understands that type
* of LSA (for LSA types with U-bit == 0). But as we do not support any
* optional LSA types, this is not needed yet.
*/
return 1;
}
}
static int
unknown_lsa_type(u32 type)
@ -105,6 +129,9 @@ unknown_lsa_type(u32 type)
case LSA_T_NSSA:
case LSA_T_LINK:
case LSA_T_PREFIX:
case LSA_T_RI_LINK:
case LSA_T_RI_AREA:
case LSA_T_RI_AS:
return 0;
default:
@ -112,28 +139,47 @@ unknown_lsa_type(u32 type)
}
}
#define LSA_V2_TMAX 8
static const u16 lsa_v2_types[LSA_V2_TMAX] =
{0, LSA_T_RT, LSA_T_NET, LSA_T_SUM_NET, LSA_T_SUM_RT, LSA_T_EXT, 0, LSA_T_NSSA};
/* Maps OSPFv2 types to OSPFv3 types */
static const u16 lsa_v2_types[] = {
0, LSA_T_RT, LSA_T_NET, LSA_T_SUM_NET, LSA_T_SUM_RT, LSA_T_EXT, 0, LSA_T_NSSA,
0, LSA_T_OPAQUE_LINK, LSA_T_OPAQUE_AREA, LSA_T_OPAQUE_AS
};
/* Maps OSPFv2 opaque types to OSPFv3 function codes */
static const u16 opaque_lsa_types[] = {
[LSA_OT_RI] = LSA_T_RI_,
};
/* Maps (subset of) OSPFv3 function codes to OSPFv2 opaque types */
static const u8 opaque_lsa_types_inv[] = {
[LSA_T_RI_] = LSA_OT_RI,
};
#define LOOKUP(a, i) ({ uint _i = (i); (_i < ARRAY_SIZE(a)) ? a[_i] : 0; })
void
lsa_get_type_domain_(u32 itype, struct ospf_iface *ifa, u32 *otype, u32 *domain)
lsa_get_type_domain_(u32 type, u32 id, struct ospf_iface *ifa, u32 *otype, u32 *domain)
{
if (ospf_is_v2(ifa->oa->po))
{
itype = itype & LSA_T_V2_MASK;
itype = (itype < LSA_V2_TMAX) ? lsa_v2_types[itype] : 0;
type = type & LSA_T_V2_MASK;
type = LOOKUP(lsa_v2_types, type);
uint code;
if (LSA_FUNCTION(type) == LSA_T_OPAQUE_)
if (code = LOOKUP(opaque_lsa_types, id >> 24))
type = code | LSA_UBIT | LSA_SCOPE(type);
}
else
{
/* For unkown LSAs without U-bit change scope to LSA_SCOPE_LINK */
if (unknown_lsa_type(itype) && !(itype & LSA_UBIT))
itype = itype & ~LSA_SCOPE_MASK;
if (unknown_lsa_type(type) && !(type & LSA_UBIT))
type = type & ~LSA_SCOPE_MASK;
}
*otype = itype;
*otype = type;
switch (LSA_SCOPE(itype))
switch (LSA_SCOPE(type))
{
case LSA_SCOPE_LINK:
*domain = ifa->iface_id;
@ -150,6 +196,12 @@ lsa_get_type_domain_(u32 itype, struct ospf_iface *ifa, u32 *otype, u32 *domain)
}
}
u32
lsa_get_opaque_type(u32 type)
{
return LOOKUP(opaque_lsa_types_inv, LSA_FUNCTION(type));
}
void
lsa_generate_checksum(struct ospf_lsa_header *lsa, const u8 *body)
@ -548,6 +600,17 @@ lsa_validate_prefix(struct ospf_lsa_header *lsa, struct ospf_lsa_prefix *body)
return lsa_validate_pxlist(lsa, body->pxcount, sizeof(struct ospf_lsa_prefix), (u8 *) body);
}
static int
lsa_validate_ri(struct ospf_lsa_header *lsa UNUSED, struct ospf_lsa_net *body UNUSED)
{
/*
* There should be proper validation. But we do not really process RI LSAs, so
* we can just accept them like another unknown opaque LSAs.
*/
return 1;
}
/**
* lsa_validate - check whether given LSA is valid
@ -577,6 +640,14 @@ lsa_validate(struct ospf_lsa_header *lsa, u32 lsa_type, int ospf2, void *body)
case LSA_T_EXT:
case LSA_T_NSSA:
return lsa_validate_ext2(lsa, body);
case LSA_T_RI_LINK:
case LSA_T_RI_AREA:
case LSA_T_RI_AS:
return lsa_validate_ri(lsa, body);
case LSA_T_OPAQUE_LINK:
case LSA_T_OPAQUE_AREA:
case LSA_T_OPAQUE_AS:
return 1; /* Unknown Opaque LSAs */
default:
return 0; /* Should not happen, unknown LSAs are already rejected */
}
@ -600,6 +671,10 @@ lsa_validate(struct ospf_lsa_header *lsa, u32 lsa_type, int ospf2, void *body)
return lsa_validate_link(lsa, body);
case LSA_T_PREFIX:
return lsa_validate_prefix(lsa, body);
case LSA_T_RI_LINK:
case LSA_T_RI_AREA:
case LSA_T_RI_AS:
return lsa_validate_ri(lsa, body);
default:
return 1; /* Unknown LSAs are OK in OSPFv3 */
}

9
proto/ospf/lsalib.h
View file

@ -36,16 +36,21 @@ struct ospf_lsa_rt_walk {
};
void lsa_get_type_domain_(u32 itype, struct ospf_iface *ifa, u32 *otype, u32 *domain);
void lsa_get_type_domain_(u32 type, u32 id, struct ospf_iface *ifa, u32 *otype, u32 *domain);
static inline void lsa_get_type_domain(struct ospf_lsa_header *lsa, struct ospf_iface *ifa, u32 *otype, u32 *domain)
{ lsa_get_type_domain_(lsa->type_raw, ifa, otype, domain); }
{ lsa_get_type_domain_(lsa->type_raw, lsa->id, ifa, otype, domain); }
static inline u32 lsa_get_etype(struct ospf_lsa_header *h, struct ospf_proto *p)
{ return ospf_is_v2(p) ? (h->type_raw & LSA_T_V2_MASK) : h->type_raw; }
/* Assuming OSPFv2 - All U-bit LSAs are mapped to Opaque LSAs */
static inline int lsa_is_opaque(u32 type)
{ return !!(type & LSA_UBIT); }
u32 lsa_get_opaque_type(u32 type);
int lsa_flooding_allowed(u32 type, u32 domain, struct ospf_iface *ifa);
int lsa_is_acceptable(u32 type, struct ospf_neighbor *n, struct ospf_proto *p);
void lsa_generate_checksum(struct ospf_lsa_header *lsa, const u8 *body);
u16 lsa_verify_checksum(const void *lsa_n, int lsa_len);

2
proto/ospf/lsreq.c
View file

@ -125,7 +125,7 @@ ospf_receive_lsreq(struct ospf_packet *pkt, struct ospf_iface *ifa,
id = ntohl(lsrs[i].id);
rt = ntohl(lsrs[i].rt);
lsa_get_type_domain_(ntohl(lsrs[i].type), ifa, &type, &domain);
lsa_get_type_domain_(ntohl(lsrs[i].type), id, ifa, &type, &domain);
DBG("Processing requested LSA: Type: %04x, Id: %R, Rt: %R\n", type, id, rt);

9
proto/ospf/lsupd.c
View file

@ -171,7 +171,8 @@ ospf_add_flushed_to_lsrt(struct ospf_proto *p, struct ospf_neighbor *n)
WALK_SLIST(en, p->lsal)
if ((en->lsa.age == LSA_MAXAGE) && (en->lsa_body != NULL) &&
lsa_flooding_allowed(en->lsa_type, en->domain, n->ifa))
lsa_flooding_allowed(en->lsa_type, en->domain, n->ifa) &&
lsa_is_acceptable(en->lsa_type, n, p))
ospf_lsa_lsrt_up(en, n);
/* If we found any flushed LSA, we send them ASAP */
@ -287,9 +288,9 @@ ospf_flood_lsa(struct ospf_proto *p, struct top_hash_entry *en, struct ospf_neig
if (n == from)
continue;
/* In OSPFv3, there should be check whether receiving router understand
that type of LSA (for LSA types with U-bit == 0). But as we do not support
any optional LSA types, this is not needed yet */
/* Check whether optional LSAs are supported by neighbor */
if (!lsa_is_acceptable(en->lsa_type, n, p))
continue;
/* 13.3 (1d) - add LSA to the link state retransmission list */
ospf_lsa_lsrt_up(en, n);

6
proto/ospf/ospf.c
View file

@ -92,11 +92,13 @@
* - RFC 2328 - main OSPFv2 standard
* - RFC 5340 - main OSPFv3 standard
* - RFC 3101 - OSPFv2 NSSA areas
* - RFC 5250 - OSPFv2 Opaque LSAs
* - RFC 5709 - OSPFv2 HMAC-SHA Cryptographic Authentication
* - RFC 5838 - OSPFv3 Support of Address Families
* - RFC 6549 - OSPFv2 Multi-Instance Extensions
* - RFC 6987 - OSPF Stub Router Advertisement
* - RFC 7166 - OSPFv3 Authentication Trailer
* - RFC 7770 - OSPF Router Information LSA
*/
#include <stdlib.h>
@ -239,6 +241,7 @@ ospf_start(struct proto *P)
p->rfc1583 = c->rfc1583;
p->stub_router = c->stub_router;
p->merge_external = c->merge_external;
p->instance_id = c->instance_id;
p->asbr = c->asbr;
p->ecmp = c->ecmp;
p->tick = c->tick;
@ -648,6 +651,9 @@ ospf_reconfigure(struct proto *P, struct proto_config *CF)
if (p->rfc1583 != new->rfc1583)
return 0;
if (p->instance_id != new->instance_id)
return 0;
if (old->abr != new->abr)
return 0;

50
proto/ospf/ospf.h
View file

@ -223,6 +223,7 @@ struct ospf_proto
u8 rfc1583; /* RFC1583 compatibility */
u8 stub_router; /* Do not forward transit traffic */
u8 merge_external; /* Should i merge external routes? */
u8 instance_id; /* Differentiate between more OSPF instances */
u8 asbr; /* May i originate any ext/NSSA lsa? */
u8 ecmp; /* Maximal number of nexthops in ECMP route, or 0 */
u64 csn64; /* Last used cryptographic sequence number */
@ -466,6 +467,7 @@ struct ospf_neighbor
#define OPT_L_V2 0x0010 /* OSPFv2, link-local signaling, not used */
#define OPT_R 0x0010 /* OSPFv3, originator is active router */
#define OPT_DC 0x0020 /* Related to demand circuits, not used */
#define OPT_O 0x0040 /* OSPFv2 Opaque LSA (RFC 5250) */
#define OPT_AF 0x0100 /* OSPFv3 Address Families (RFC 5838) */
#define OPT_L_V3 0x0200 /* OSPFv3, link-local signaling */
#define OPT_AT 0x0400 /* OSPFv3, authentication trailer */
@ -541,6 +543,8 @@ struct ospf_auth3
#define DBDES_IMMS (DBDES_I | DBDES_M | DBDES_MS)
/* OSPFv3 LSA Types / LSA Function Codes */
/* https://www.iana.org/assignments/ospfv3-parameters/ospfv3-parameters.xhtml#ospfv3-parameters-3 */
#define LSA_T_RT 0x2001
#define LSA_T_NET 0x2002
#define LSA_T_SUM_NET 0x2003
@ -549,9 +553,25 @@ struct ospf_auth3
#define LSA_T_NSSA 0x2007
#define LSA_T_LINK 0x0008
#define LSA_T_PREFIX 0x2009
#define LSA_T_RI_ 0x000C
#define LSA_T_RI_LINK 0x800C
#define LSA_T_RI_AREA 0xA00C
#define LSA_T_RI_AS 0xC00C
#define LSA_T_OPAQUE_ 0x1FFF
#define LSA_T_OPAQUE_LINK 0x9FFF
#define LSA_T_OPAQUE_AREA 0xBFFF
#define LSA_T_OPAQUE_AS 0xDFFF
#define LSA_T_V2_OPAQUE_ 0x0009
#define LSA_T_V2_MASK 0x00ff
/* OSPFv2 Opaque LSA Types */
/* https://www.iana.org/assignments/ospf-opaque-types/ospf-opaque-types.xhtml#ospf-opaque-types-2 */
#define LSA_OT_RI 0x04
#define LSA_FUNCTION_MASK 0x1FFF
#define LSA_FUNCTION(type) ((type) & LSA_FUNCTION_MASK)
#define LSA_UBIT 0x8000
#define LSA_SCOPE_LINK 0x0000
@ -560,6 +580,7 @@ struct ospf_auth3
#define LSA_SCOPE_RES 0x6000
#define LSA_SCOPE_MASK 0x6000
#define LSA_SCOPE(type) ((type) & LSA_SCOPE_MASK)
#define LSA_SCOPE_ORDER(type) (((type) >> 13) & 0x3)
#define LSA_MAXAGE 3600 /* 1 hour */
@ -586,9 +607,20 @@ struct ospf_auth3
#define LSA_EXT2_TOS 0x7F000000
#define LSA_EXT2_EBIT 0x80000000
#define LSA_EXT3_EBIT 0x4000000
#define LSA_EXT3_FBIT 0x2000000
#define LSA_EXT3_TBIT 0x1000000
#define LSA_EXT3_EBIT 0x04000000
#define LSA_EXT3_FBIT 0x02000000
#define LSA_EXT3_TBIT 0x01000000
/* OSPF Router Information (RI) TLVs */
/* https://www.iana.org/assignments/ospf-parameters/ospf-parameters.xhtml#ri-tlv */
#define LSA_RI_RIC 1
#define LSA_RI_RFC 2
/* OSPF Router Informational Capability Bits */
/* https://www.iana.org/assignments/ospf-parameters/ospf-parameters.xhtml#router-informational-capability */
#define LSA_RIC_GR_CAPABLE 0
#define LSA_RIC_GR_HELPER 1
#define LSA_RIC_STUB_ROUTER 2
struct ospf_lsa_header
@ -731,6 +763,18 @@ struct ospf_lsa_prefix
u32 rest[];
};
struct ospf_tlv
{
#ifdef CPU_BIG_ENDIAN
u16 type;
u16 length;
#else
u16 length;
u16 type;
#endif
u32 data[];
};
static inline uint
lsa_net_count(struct ospf_lsa_header *lsa)

49
proto/ospf/topology.c
View file

@ -224,12 +224,17 @@ ospf_do_originate_lsa(struct ospf_proto *p, struct top_hash_entry *en, void *lsa
/*
* lsa.type_raw is initialized by ospf_hash_get() to OSPFv3 LSA type.
* lsa_set_options() implicitly converts it to OSPFv2 LSA type, assuming that
* old type is just new type masked by 0xff. That is not universally true,
* but it holds for all OSPFv2 types currently supported by BIRD.
* old type is just new type masked by 0xff. That holds for most OSPFv2 types,
* but we have to fix it for opaque LSAs.
*/
if (ospf_is_v2(p))
{
if (lsa_is_opaque(en->lsa_type))
en->lsa.type_raw = LSA_T_V2_OPAQUE_ + LSA_SCOPE_ORDER(en->lsa_type);
lsa_set_options(&en->lsa, lsa_opts);
}
mb_free(en->lsa_body);
en->lsa_body = lsa_body;
@ -273,6 +278,10 @@ ospf_originate_lsa(struct ospf_proto *p, struct ospf_new_lsa *lsa)
u16 lsa_blen = p->lsab_used;
u16 lsa_length = sizeof(struct ospf_lsa_header) + lsa_blen;
/* For OSPFv2 Opaque LSAs, LS ID consists of Opaque Type and Opaque ID */
if (ospf_is_v2(p) && lsa_is_opaque(lsa->type))
lsa->id |= (u32) lsa_get_opaque_type(lsa->type) << 24;
en = ospf_hash_get(p->gr, lsa->dom, lsa->id, p->router_id, lsa->type);
if (!SNODE_VALID(en))
@ -1658,6 +1667,41 @@ ospf_originate_prefix_net_lsa(struct ospf_proto *p, struct ospf_iface *ifa)
ifa->pxn_lsa = ospf_originate_lsa(p, &lsa);
}
/*
* Router Information LSA handling
* Type = LSA_T_RI_AREA, opaque type = LSA_OT_RI
*/
void
ospf_add_ric_tlv(struct ospf_proto *p)
{
struct ospf_tlv *ri = lsab_allocz(p, sizeof(struct ospf_tlv) + sizeof(u32));
ri->type = LSA_RI_RIC;
ri->length = sizeof(struct ospf_tlv) + sizeof(u32);
BIT32R_SET(ri->data, LSA_RIC_STUB_ROUTER);
}
void
ospf_originate_ri_lsa(struct ospf_proto *p, struct ospf_area *oa)
{
struct ospf_new_lsa lsa = {
.type = LSA_T_RI_AREA,
.dom = oa->areaid,
.id = p->instance_id
};
ospf_add_ric_tlv(p);
ospf_originate_lsa(p, &lsa);
}
/*
* Generic topology code
*/
static inline int breaks_minlsinterval(struct top_hash_entry *en)
{ return en && (en->lsa.age < LSA_MAXAGE) && (lsa_inst_age(en) < MINLSINTERVAL); }
@ -1692,6 +1736,7 @@ ospf_update_topology(struct ospf_proto *p)
ospf_originate_rt_lsa(p, oa);
ospf_originate_prefix_rt_lsa(p, oa);
ospf_originate_ri_lsa(p, oa);
oa->update_rt_lsa = 0;
}
}