From: Denis Ovsienko <denis@ovsienko.info>
Date: Sat, 12 Feb 2022 17:46:03 +0000 (+0000)
Subject: BGP: Refine the previous commit.
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/25e38f8a2a9f61cf752c0a4a8e1814cb065f6f23

BGP: Refine the previous commit.

Fix references in some comments, reduce scope of a couple variables,
lose an excess ND_TCHECK_LEN() before nd_printjn() and update the change
log.
---

diff --git a/CHANGES b/CHANGES
index dec9d64f..7f0646d3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -10,6 +10,7 @@ Monthday, Month DD, YYYY by gharris and denis
       VQP: Do not print unknown error codes twice.
       ZMTP: Replace custom code with bittok2str().
       BFD: Add support for S-BFD and spell LAG in uppercase.
+      BGP: Update cease notification decoding to RFC 9003.
     User interface:
       Add --print-sampling to print every Nth packet instead of all.
     Source code:
diff --git a/print-bgp.c b/print-bgp.c
index f5c3dfad..ba927e4b 100644
--- a/print-bgp.c
+++ b/print-bgp.c
@@ -273,9 +273,8 @@ static const struct tok bgp_notify_major_values[] = {
     { 0, NULL}
 };
 
-/* draft-ietf-idr-cease-subcode-02 */
+/* 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
 static const struct tok bgp_notify_minor_cease_values[] = {
@@ -2939,8 +2938,6 @@ bgp_notification_print(netdissect_options *ndo,
     const struct bgp_notification *bgp_notification_header;
     const u_char *tptr;
     uint8_t bgpn_major, bgpn_minor;
-    uint8_t shutdown_comm_length;
-    uint8_t remainder_offset;
 
     ND_TCHECK_LEN(dat, BGP_NOTIFICATION_SIZE);
     if (length<BGP_NOTIFICATION_SIZE)
@@ -2993,7 +2990,7 @@ bgp_notification_print(netdissect_options *ndo,
                           bgpn_minor),
                   bgpn_minor);
 
-        /* draft-ietf-idr-cease-subcode-02 mentions optionally 7 bytes
+        /* RFC 4486 mentions optionally 7 bytes
          * for the maxprefix subtype, which may contain AFI, SAFI and MAXPREFIXES
          */
         if(bgpn_minor == BGP_NOTIFY_MINOR_CEASE_MAXPRFX && length >= BGP_NOTIFICATION_SIZE + 7) {
@@ -3006,15 +3003,15 @@ bgp_notification_print(netdissect_options *ndo,
                       GET_BE_U_4(tptr + 3));
         }
         /*
-         * draft-ietf-idr-shutdown describes a method to send a communication
+         * RFC 9003 describes a method to send a communication
          * intended for human consumption regarding the Administrative Shutdown
          */
         if ((bgpn_minor == BGP_NOTIFY_MINOR_CEASE_SHUT ||
              bgpn_minor == BGP_NOTIFY_MINOR_CEASE_RESET) &&
              length >= BGP_NOTIFICATION_SIZE + 1) {
             tptr = dat + BGP_NOTIFICATION_SIZE;
-            shutdown_comm_length = GET_U_1(tptr);
-            remainder_offset = 0;
+            uint8_t shutdown_comm_length = GET_U_1(tptr);
+            uint8_t remainder_offset = 0;
             /* garbage, hexdump it all */
             if (shutdown_comm_length > length - (BGP_NOTIFICATION_SIZE + 1)) {
                 ND_PRINT(", invalid Shutdown Communication length");
@@ -3025,7 +3022,6 @@ bgp_notification_print(netdissect_options *ndo,
             }
             /* a proper shutdown communication */
             else {
-                ND_TCHECK_LEN(tptr + 1, shutdown_comm_length);
                 ND_PRINT(", Shutdown Communication (length: %u): \"", shutdown_comm_length);
                 nd_printjn(ndo, tptr+1, shutdown_comm_length);
                 ND_PRINT("\"");