From: Donald Sharp <sharpd@cumulusnetworks.com>
Date: Fri, 20 Sep 2019 10:41:02 +0000 (-0400)
Subject: bgpd: Invalid NH's should send an apropriate reason code
X-Git-Tag: frr-7.2~16^2
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=refs%2Fpull%2F5027%2Fhead;p=mirror%2Ffrr.git

bgpd: Invalid NH's should send an apropriate reason code

RFC 4271 sec 6.3 p33, In the case of a BGP_NEXTHOP attribute with an
incorrect value, FRR is supposed to send a notification
and include 'Corresponding type, length and value of the NEXT_HOP
attribute in the notification data.

Fixes: #4997
Signed-off-by: Nikos <ntriantafillis@gmail.com>
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
---

diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index ab9dc3092a..47ecfce41e 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -1305,14 +1305,20 @@ bgp_attr_nexthop_valid(struct peer *peer, struct attr *attr)
 	if ((IPV4_NET0(nexthop_h) || IPV4_NET127(nexthop_h)
 	     || IPV4_CLASS_DE(nexthop_h))
 	    && !BGP_DEBUG(allow_martians, ALLOW_MARTIANS)) {
+		uint8_t data[7]; /* type(2) + length(1) + nhop(4) */
 		char buf[INET_ADDRSTRLEN];
 
 		inet_ntop(AF_INET, &attr->nexthop.s_addr, buf,
 			  INET_ADDRSTRLEN);
 		flog_err(EC_BGP_ATTR_MARTIAN_NH, "Martian nexthop %s",
 			 buf);
-		bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
-				BGP_NOTIFY_UPDATE_INVAL_NEXT_HOP);
+		data[0] = BGP_ATTR_FLAG_TRANS;
+		data[1] = BGP_ATTR_NEXT_HOP;
+		data[2] = BGP_ATTR_NHLEN_IPV4;
+		memcpy(&data[3], &attr->nexthop.s_addr, BGP_ATTR_NHLEN_IPV4);
+		bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
+					  BGP_NOTIFY_UPDATE_INVAL_NEXT_HOP,
+					  data, 7);
 		return BGP_ATTR_PARSE_ERROR;
 	}