diff options
| author | Donatas Abraitis <donatas@opensourcerouting.org> | 2023-10-29 22:44:45 +0200 |
|---|---|---|
| committer | David Lamparter <equinox@opensourcerouting.org> | 2024-05-06 03:02:55 +0200 |
| commit | b21e7b8fe8c4970f2f6f794cb78bcc93057af94f (patch) | |
| tree | 2c4d487fadd2f7fa201cb0b43509a5961e7f908c | |
| parent | 3f79135cc7683f71732cfa24e05e4fe3eaf5df47 (diff) | |
bgpd: Ignore handling NLRIs if we received MP_UNREACH_NLRI
If we receive MP_UNREACH_NLRI, we should stop handling remaining NLRIs if
no mandatory path attributes received.
In other words, if MP_UNREACH_NLRI received, the remaining NLRIs should be handled
as a new data, but without mandatory attributes, it's a malformed packet.
In normal case, this MUST not happen at all, but to avoid crashing bgpd, we MUST
handle that.
Reported-by: Iggy Frankovic <iggyfran@amazon.com>
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
(cherry picked from commit c37119df45bbf4ef713bc10475af2ee06e12f3bf)
| -rw-r--r-- | bgpd/bgp_attr.c | 19 | ||||
| -rw-r--r-- | bgpd/bgp_attr.h | 1 | ||||
| -rw-r--r-- | bgpd/bgp_packet.c | 7 |
3 files changed, 17 insertions, 10 deletions
diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c index 6516e7f808..0c69dd8878 100644 --- a/bgpd/bgp_attr.c +++ b/bgpd/bgp_attr.c @@ -3120,15 +3120,6 @@ static int bgp_attr_check(struct peer *peer, struct attr *attr, !length) return BGP_ATTR_PARSE_WITHDRAW; - /* "An UPDATE message that contains the MP_UNREACH_NLRI is not required - to carry any other path attributes.", though if MP_REACH_NLRI or NLRI - are present, it should. Check for any other attribute being present - instead. - */ - if ((!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI)) && - CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_UNREACH_NLRI)))) - return BGP_ATTR_PARSE_PROCEED; - if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_ORIGIN))) type = BGP_ATTR_ORIGIN; @@ -3147,6 +3138,16 @@ static int bgp_attr_check(struct peer *peer, struct attr *attr, && !CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF))) type = BGP_ATTR_LOCAL_PREF; + /* An UPDATE message that contains the MP_UNREACH_NLRI is not required + * to carry any other path attributes. Though if MP_REACH_NLRI or NLRI + * are present, it should. Check for any other attribute being present + * instead. + */ + if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI)) && + CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_UNREACH_NLRI))) + return type ? BGP_ATTR_PARSE_MISSING_MANDATORY + : BGP_ATTR_PARSE_PROCEED; + /* If any of the well-known mandatory attributes are not present * in an UPDATE message, then "treat-as-withdraw" MUST be used. */ diff --git a/bgpd/bgp_attr.h b/bgpd/bgp_attr.h index 23767153b2..27708c0689 100644 --- a/bgpd/bgp_attr.h +++ b/bgpd/bgp_attr.h @@ -382,6 +382,7 @@ enum bgp_attr_parse_ret { /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */ BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3, + BGP_ATTR_PARSE_MISSING_MANDATORY = -4, }; struct bpacket_attr_vec_arr; diff --git a/bgpd/bgp_packet.c b/bgpd/bgp_packet.c index 7c137a533d..06f9612d61 100644 --- a/bgpd/bgp_packet.c +++ b/bgpd/bgp_packet.c @@ -1951,7 +1951,12 @@ static int bgp_update_receive(struct peer *peer, bgp_size_t size) /* Network Layer Reachability Information. */ update_len = end - stream_pnt(s); - if (update_len && attribute_len) { + /* If we received MP_UNREACH_NLRI attribute, but also NLRIs, then + * NLRIs should be handled as a new data. Though, if we received + * NLRIs without mandatory attributes, they should be ignored. + */ + if (update_len && attribute_len && + attr_parse_ret != BGP_ATTR_PARSE_MISSING_MANDATORY) { /* Set NLRI portion to structure. */ nlris[NLRI_UPDATE].afi = AFI_IP; nlris[NLRI_UPDATE].safi = SAFI_UNICAST; |