From: benno <benno@openbsd.org>
Date: Mon, 24 Apr 2017 20:35:35 +0000 (+0000)
Subject: Print bgp administrative shutdown messages (draft-ietf-idr-shutdown)
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=06dacf5578ee4fb3a6bc2024a1a36e3401d470b1;p=openbsd

Print bgp administrative shutdown messages (draft-ietf-idr-shutdown)
From Job Snijders <job -AT instituut -DOT- net>, thanks!

ok canacar@, deraadt@
---

diff --git a/usr.sbin/tcpdump/print-bgp.c b/usr.sbin/tcpdump/print-bgp.c
index d028d671893..d8f233ffdf5 100644
--- a/usr.sbin/tcpdump/print-bgp.c
+++ b/usr.sbin/tcpdump/print-bgp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: print-bgp.c,v 1.20 2016/10/27 08:21:58 phessler Exp $	*/
+/*	$OpenBSD: print-bgp.c,v 1.21 2017/04/24 20:35:35 benno Exp $	*/
 
 /*
  * Copyright (C) 1999 WIDE Project.
@@ -228,9 +228,13 @@ static const char *bgpnotify_minor_update[] = {
 
 /* RFC 4486 */
 #define BGP_NOTIFY_MINOR_CEASE_MAXPRFX  1
+/* draft-ietf-idr-shutdown-07 */
+#define BGP_NOTIFY_MINOR_CEASE_SHUT			2
+#define BGP_NOTIFY_MINOR_CEASE_RESET			4
+#define BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN	128
 static const char *bgpnotify_minor_cease[] = {
-	NULL, "Maximum Number of Prefixes Reached", "Administratively Shutdown",
-	"Peer De-configured", "Administratively Reset", "Connection Rejected",
+	NULL, "Maximum Number of Prefixes Reached", "Administrative Shutdown",
+	"Peer De-configured", "Administrative Reset", "Connection Rejected",
 	"Other Configuration Change", "Connection Collision Resolution",
 	"Out of Resources",
 };
@@ -996,6 +1000,8 @@ bgp_notification_print(const u_char *dat, int length)
 	u_int16_t af;
 	u_int8_t safi;
 	const u_char *p;
+	uint8_t shutdown_comm_length;
+	char shutstring[BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN + 1];
 
 	TCHECK2(dat[0], BGP_NOTIFICATION_SIZE);
 	memcpy(&bgpn, dat, BGP_NOTIFICATION_SIZE);
@@ -1026,9 +1032,43 @@ bgp_notification_print(const u_char *dat, int length)
 
 			printf(" Max Prefixes: %u", EXTRACT_32BITS(p+3));
 		}
+
+		/*
+		 * draft-ietf-idr-shutdown describes a method to send a
+		 * message intended for human consumption regarding the
+		 * Administrative Shutdown or Reset event. This is called
+		 * the "Shutdown Communication". The communication is
+		 * UTF-8 encoded and may be no longer than 128 bytes.
+		 */
+		if ((bgpn.bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
+		    bgpn.bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
+		    (length >= BGP_NOTIFICATION_SIZE + 1)) {
+			p = dat + BGP_NOTIFICATION_SIZE;
+			TCHECK2(*p, 1);
+			shutdown_comm_length = *(p);
+
+			/* sanity checking */
+			if (shutdown_comm_length == 0)
+				return;
+			if (shutdown_comm_length >
+			    BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN)
+				return;
+			if (length < (shutdown_comm_length + 1 + BGP_NOTIFICATION_SIZE))
+				return;
+			TCHECK2(*(p+1), shutdown_comm_length);
+			
+			/* a proper shutdown communication */
+			printf(", Shutdown Communication [len %u]: \"",
+			    shutdown_comm_length);
+			memset(shutstring, 0, BGP_NOTIFY_MINOR_CEASE_ADMIN_SHUTDOWN_LEN + 1);
+			memcpy(shutstring, p+1, shutdown_comm_length);
+			safeputs(shutstring);
+			printf("\"");
+		}
 	}
 
 	return;
+
 trunc:
 	printf("[|BGP]");
 }