diff options
| -rw-r--r-- | bgpd/bgp_attr.c | 34 | ||||
| -rw-r--r-- | bgpd/bgp_attr.h | 1 | ||||
| -rw-r--r-- | bgpd/bgp_packet.c | 7 |
3 files changed, 29 insertions, 13 deletions
diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c index 4bc28fe237..373db7c735 100644 --- a/bgpd/bgp_attr.c +++ b/bgpd/bgp_attr.c @@ -2846,18 +2846,12 @@ static int bgp_attr_check(struct peer *peer, struct attr *attr) uint8_t type = 0; /* BGP Graceful-Restart End-of-RIB for IPv4 unicast is signaled as an - * empty UPDATE. */ - if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag) - return BGP_ATTR_PARSE_PROCEED; - - /* "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. + * empty UPDATE. Treat-as-withdraw, otherwise if we just ignore it, + * we will pass it to be processed as a normal UPDATE without mandatory + * attributes, that could lead to harmful behavior. */ - 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(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag) + return BGP_ATTR_PARSE_WITHDRAW; if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_ORIGIN))) type = BGP_ATTR_ORIGIN; @@ -2877,6 +2871,16 @@ 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. */ @@ -3272,7 +3276,13 @@ done: aspath_unintern(&as4_path); } - if (ret != BGP_ATTR_PARSE_ERROR) { + /* If we received an UPDATE with mandatory attributes, then + * the unrecognized transitive optional attribute of that + * path MUST be passed. Otherwise, it's an error, and from + * security perspective it might be very harmful if we continue + * here with the unrecognized attributes. + */ + if (ret == BGP_ATTR_PARSE_PROCEED) { /* Finally intern unknown attribute. */ if (attr->transit) attr->transit = transit_intern(attr->transit); diff --git a/bgpd/bgp_attr.h b/bgpd/bgp_attr.h index e6e953364b..cf9c681b0d 100644 --- a/bgpd/bgp_attr.h +++ b/bgpd/bgp_attr.h @@ -339,6 +339,7 @@ typedef enum { */ BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3, BGP_ATTR_PARSE_EOR = -4, + BGP_ATTR_PARSE_MISSING_MANDATORY = -5, } bgp_attr_parse_ret_t; struct bpacket_attr_vec_arr; diff --git a/bgpd/bgp_packet.c b/bgpd/bgp_packet.c index 2c8a375a55..164e7ae721 100644 --- a/bgpd/bgp_packet.c +++ b/bgpd/bgp_packet.c @@ -1625,7 +1625,12 @@ 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) { + /* 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; |