diff options
Diffstat (limited to 'proto/ospf/lsalib.c')
| -rw-r--r-- | proto/ospf/lsalib.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/proto/ospf/lsalib.c b/proto/ospf/lsalib.c index 64e94a9..7ee3aa4 100644 --- a/proto/ospf/lsalib.c +++ b/proto/ospf/lsalib.c @@ -291,6 +291,219 @@ lsa_comp(struct ospf_lsa_header *l1, struct ospf_lsa_header *l2) return CMP_SAME; } +#define HDRLEN sizeof(struct ospf_lsa_header) + +static int +lsa_validate_rt(struct ospf_lsa_header *lsa, struct ospf_lsa_rt *body) +{ + unsigned int i, max; + + if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_rt))) + return 0; + + struct ospf_lsa_rt_link *rtl = (struct ospf_lsa_rt_link *) (body + 1); + max = lsa_rt_count(lsa); + +#ifdef OSPFv2 + if (body->links != max) + return 0; +#endif + + for (i = 0; i < max; i++) + { + u8 type = rtl[i].type; + if (!((type == LSART_PTP) || + (type == LSART_NET) || +#ifdef OSPFv2 + (type == LSART_STUB) || +#endif + (type == LSART_VLNK))) + return 0; + } + return 1; +} + +static int +lsa_validate_net(struct ospf_lsa_header *lsa, struct ospf_lsa_net *body) +{ + if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_net))) + return 0; + + return 1; +} + +#ifdef OSPFv2 + +static int +lsa_validate_sum(struct ospf_lsa_header *lsa, struct ospf_lsa_sum *body) +{ + if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_sum))) + return 0; + + /* First field should have TOS = 0, we ignore other TOS fields */ + if ((body->metric & LSA_SUM_TOS) != 0) + return 0; + + return 1; +} +#define lsa_validate_sum_net(A,B) lsa_validate_sum(A,B) +#define lsa_validate_sum_rt(A,B) lsa_validate_sum(A,B) + +static int +lsa_validate_ext(struct ospf_lsa_header *lsa, struct ospf_lsa_ext *body) +{ + if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_ext))) + return 0; + + /* First field should have TOS = 0, we ignore other TOS fields */ + if ((body->metric & LSA_EXT_TOS) != 0) + return 0; + + return 1; +} + +#else /* OSPFv3 */ + +static inline int +pxlen(u32 *buf) +{ + return *buf >> 24; +} + +static int +lsa_validate_sum_net(struct ospf_lsa_header *lsa, struct ospf_lsa_sum_net *body) +{ + if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_sum_net) + 4)) + return 0; + + u8 pxl = pxlen(body->prefix); + if (pxl > MAX_PREFIX_LENGTH) + return 0; + + if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_sum_net) + + IPV6_PREFIX_SPACE(pxl))) + return 0; + + return 1; +} + + +static int +lsa_validate_sum_rt(struct ospf_lsa_header *lsa, struct ospf_lsa_sum_rt *body) +{ + if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_sum_rt))) + return 0; + + return 1; +} + +static int +lsa_validate_ext(struct ospf_lsa_header *lsa, struct ospf_lsa_ext *body) +{ + if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_ext) + 4)) + return 0; + + u8 pxl = pxlen(body->rest); + if (pxl > MAX_PREFIX_LENGTH) + return 0; + + int len = IPV6_PREFIX_SPACE(pxl); + if (body->metric & LSA_EXT_FBIT) // forwardinf address + len += 16; + if (body->metric & LSA_EXT_TBIT) // route tag + len += 4; + if (*body->rest & 0xFFFF) // referenced LS type field + len += 4; + + if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_ext) + len)) + return 0; + + return 1; +} + +static int +lsa_validate_pxlist(struct ospf_lsa_header *lsa, u32 pxcount, unsigned int offset, u8 *pbuf) +{ + unsigned int bound = lsa->length - HDRLEN - 4; + u32 i; + + for (i = 0; i < pxcount; i++) + { + if (offset > bound) + return 0; + + u8 pxl = pxlen((u32 *) (pbuf + offset)); + if (pxl > MAX_PREFIX_LENGTH) + return 0; + + offset += IPV6_PREFIX_SPACE(pxl); + } + + if (lsa->length != (HDRLEN + offset)) + return 0; + + return 1; +} + +static int +lsa_validate_link(struct ospf_lsa_header *lsa, struct ospf_lsa_link *body) +{ + if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_link))) + return 0; + + return lsa_validate_pxlist(lsa, body->pxcount, sizeof(struct ospf_lsa_link), (u8 *) body); +} + +static int +lsa_validate_prefix(struct ospf_lsa_header *lsa, struct ospf_lsa_prefix *body) +{ + if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_prefix))) + return 0; + + return lsa_validate_pxlist(lsa, body->pxcount, sizeof(struct ospf_lsa_prefix), (u8 *) body); +} + +#endif + + +/** + * lsa_validate - check whether given LSA is valid + * @lsa: LSA header + * @body: pointer to LSA body + * + * Checks internal structure of given LSA body (minimal length, + * consistency). Returns true if valid. + */ + +int +lsa_validate(struct ospf_lsa_header *lsa, void *body) +{ + switch (lsa->type) + { + case LSA_T_RT: + return lsa_validate_rt(lsa, body); + case LSA_T_NET: + return lsa_validate_net(lsa, body); + case LSA_T_SUM_NET: + return lsa_validate_sum_net(lsa, body); + case LSA_T_SUM_RT: + return lsa_validate_sum_rt(lsa, body); + case LSA_T_EXT: + return lsa_validate_ext(lsa, body); +#ifdef OSPFv3 + case LSA_T_LINK: + return lsa_validate_link(lsa, body); + case LSA_T_PREFIX: + return lsa_validate_prefix(lsa, body); +#endif + default: + /* In OSPFv3, unknown LSAs are OK, + In OSPFv2, unknown LSAs are already rejected + */ + return 1; + } +} + /** * lsa_install_new - install new LSA into database * @po: OSPF protocol |