From: Michel Stam <m.stam@fugro.nl>
Date: Mon, 21 Jul 2014 14:40:41 +0000 (+0200)
Subject: cdp: Add power requirement to CDPv2 frames
X-Git-Tag: 0.7.10~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=619c379964fd317257cad11c220aebe13f73d552;p=thirdparty%2Flldpd.git

cdp: Add power requirement to CDPv2 frames

LLDP already supports sending power requirements, for
IEEE 802.3at. Older Cisco PoE switches do not support
LLDP and need a custom CDPv2 frame. This patch enables
support if the LLDP MED PoE frame is also sent.
---

diff --git a/src/daemon/cdp.c b/src/daemon/cdp.c
index 2ff57421..4974b00e 100644
--- a/src/daemon/cdp.c
+++ b/src/daemon/cdp.c
@@ -34,6 +34,7 @@ cdp_send(struct lldpd *global,
 	const char *platform = "Linux";
 	struct lldpd_chassis *chassis;
 	struct lldpd_mgmt *mgmt;
+	struct lldpd_port *port;
 	u_int8_t mcastaddr[] = CDP_MULTICAST_ADDR;
 	u_int8_t llcorg[] = LLC_ORG_CISCO;
 #ifdef ENABLE_FDP
@@ -47,7 +48,8 @@ cdp_send(struct lldpd *global,
 
 	log_debug("cdp", "send CDP frame on %s", hardware->h_ifname);
 
-	chassis = hardware->h_lport.p_chassis;
+	port = &(hardware->h_lport);
+	chassis = port->p_chassis;
 
 #ifdef ENABLE_FDP
 	if (version == 0) {
@@ -202,6 +204,21 @@ cdp_send(struct lldpd *global,
 	      POKE_BYTES(platform, strlen(platform)) &&
 	      POKE_END_CDP_TLV))
 		goto toobig;
+
+#ifdef ENABLE_LLDPMED
+	/* Power use */
+	if ((version >= 2) &&
+	    port->p_med_cap_enabled &&
+	    (port->p_med_power.source != LLDP_MED_POW_SOURCE_LOCAL) &&
+	    (port->p_med_power.val > 0) &&
+	    (port->p_med_power.val <= 655)) {
+		if (!(
+		      POKE_START_CDP_TLV(CDP_TLV_POWER_CONSUMPTION) &&
+		      POKE_UINT16(port->p_med_power.val * 100) &&
+		      POKE_END_CDP_TLV))
+			goto toobig;
+	}
+#endif
 	(void)POKE_SAVE(end);
 
 	/* Compute len and checksum */
diff --git a/src/daemon/cdp.h b/src/daemon/cdp.h
index a84601ab..e2d26306 100644
--- a/src/daemon/cdp.h
+++ b/src/daemon/cdp.h
@@ -43,7 +43,8 @@ enum {
 	CDP_TLV_CAPABILITIES		= 4,
 	CDP_TLV_SOFTWARE		= 5,
 	CDP_TLV_PLATFORM		= 6,
-	CDP_TLV_NATIVEVLAN		= 10
+	CDP_TLV_NATIVEVLAN		= 10,
+	CDP_TLV_POWER_CONSUMPTION	= 16
 };
 
 #define CDP_ADDRESS_PROTO_IP 0xcc