From: Vincent Bernat <vincent@bernat.im>
Date: Sun, 15 Jun 2014 07:47:03 +0000 (+0200)
Subject: cdp: don't expect and off-by-one checksum
X-Git-Tag: 0.7.10~37
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=806eaef4832aebcf907b7b9cbf79f8cab5b24254;p=thirdparty%2Flldpd.git

cdp: don't expect and off-by-one checksum
---

diff --git a/NEWS b/NEWS
index f5b2f661..11f52084 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,8 @@ lldpd (0.7.10)
   * Features:
     + Ability to set promiscuous mode to work around bugs of some
       switches encapsulating LLDP frames inside 802.1Q frames.
+  * Fix:
+    + Fix checksum computation for Cisco CDP.
 
 lldpd (0.7.9)
   * Changes:
diff --git a/src/daemon/cdp.c b/src/daemon/cdp.c
index a66843c5..2ff57421 100644
--- a/src/daemon/cdp.c
+++ b/src/daemon/cdp.c
@@ -185,7 +185,7 @@ cdp_send(struct lldpd *global,
 			goto toobig;
 	}
 #endif
-		
+
 	/* Software version */
 	if (!(
 	      POKE_START_CDP_TLV(CDP_TLV_SOFTWARE) &&
@@ -331,8 +331,7 @@ cdp_decode(struct lldpd *cfg, char *frame, int s,
 	    1			/* cisco checksum */
 #endif
 		);
-	/* An off-by-one error may happen. Just ignore it */
-	if ((cksum != 0) && (cksum != 0xfffe)) {
+	if (cksum != 0) {
 		log_info("cdp", "incorrect CDP/FDP checksum for frame received on %s (%d)",
 			  hardware->h_ifname, cksum);
 		goto malformed;