From: Vincent Bernat <vincent@bernat.im>
Date: Mon, 12 Sep 2016 20:28:50 +0000 (+0200)
Subject: lldp: only enable LLDP-MED capibility TLV if we have that capability
X-Git-Tag: 0.9.5~12
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=03d178b6faf926b102efdadf9926754fbcc4a8cd;p=thirdparty%2Flldpd.git

lldp: only enable LLDP-MED capibility TLV if we have that capability

In fact, we are not quite coherent. With LLDP-MED disabled (lldpd with
"-M" option), we can still set some TLV. We should either disallow that
or at least not send the capability TLV since we cannot build a complete
one (we miss the device type). We chose the later.
---

diff --git a/NEWS b/NEWS
index e7066575..d104d7c3 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,8 @@ lldpd (0.9.5)
       inaccuracies.
     + Directly get media information for an interface without using
       the privileged process.
+    + LLDP-MED capability TLV is not sent when LLDP-MED is not enabled,
+      even if other LLDP-MED TLV are present.
   * Fix:
     + Compilation fix with older versions of GCC.
     + Don't use ethtool at all to get real MAC address for enslaved
diff --git a/src/daemon/protocols/lldp.c b/src/daemon/protocols/lldp.c
index 59b9f1c2..1f79fb9d 100644
--- a/src/daemon/protocols/lldp.c
+++ b/src/daemon/protocols/lldp.c
@@ -327,14 +327,16 @@ static int _lldp_send(struct lldpd *global,
 #ifdef ENABLE_LLDPMED
 	if (port->p_med_cap_enabled) {
 		/* LLDP-MED cap */
-		if (!(
-		      POKE_START_LLDP_TLV(LLDP_TLV_ORG) &&
-		      POKE_BYTES(med, sizeof(med)) &&
-		      POKE_UINT8(LLDP_TLV_MED_CAP) &&
-		      POKE_UINT16(chassis->c_med_cap_available) &&
-		      POKE_UINT8(chassis->c_med_type) &&
-		      POKE_END_LLDP_TLV))
-			goto toobig;
+		if (port->p_med_cap_enabled & LLDP_MED_CAP_CAP) {
+			if (!(
+				    POKE_START_LLDP_TLV(LLDP_TLV_ORG) &&
+				    POKE_BYTES(med, sizeof(med)) &&
+				    POKE_UINT8(LLDP_TLV_MED_CAP) &&
+				    POKE_UINT16(chassis->c_med_cap_available) &&
+				    POKE_UINT8(chassis->c_med_type) &&
+				    POKE_END_LLDP_TLV))
+				goto toobig;
+		}
 
 		/* LLDP-MED inventory */
 #define LLDP_INVENTORY(value, subtype)					\