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 2ff574215929801b205dd9c83dd8219fc1b3869e..4974b00eecbf7196654313801bb0510cae35dcfe 100644 (file)
--- 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 a84601ab2f59e1cddcf97397438f0b30fd2b57ea..e2d26306f5d7d26a6c03046e6c6e6469a6e73505 100644 (file)
--- 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