Reading of mtu discovery msgelem.

FossilOrigin-Name: 0814d4a3e43bb4adc1448b3afcfd5d6c51d4e11d6c1f758d367ed8a2f3cb4bd3

src/capwap/Makefile

@@ -121,6 +121,7 @@ CAPWAPOBJS= \
 	cw_readelem_radio_administrative_state.o \
 	cw_readelem_radio_operational_state.o \
 	cw_readelem_statistics_timer.o \
+	cw_readelem_mtu_discovery_padding.o \
 	   cw_readelem_wtp_reboot_statistics.o\
    	   cwmsg_addelem_vendor_cisco_ap_timesync.o \
 	lw_checksum.o

src/capwap/cw_readelem_mtu_discovery_padding.c

@@ -0,0 +1,40 @@
+/*
+    This file is part of libcapwap.
+
+    libcapwap is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    libcapwap is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+
+#include "capwap.h"
+#include "cw_log.h"
+
+int cw_readelem_mtu_discovery_padding(int type, uint8_t * msgelem, int len)
+{
+	if (type != CWMSGELEM_MTU_DISCOVERY_PADDING)
+		return 0;
+	if (!cw_dbg_is_level(DBG_CW_RFC))
+		return 1;
+
+	int i, n = 0;
+	for (i = 0; i < len; i++) {
+		if (msgelem[i] != 0xff)
+			n++;
+	}
+	if (n)
+		cw_dbg(DBG_CW_RFC,
+		       "MTU discovery padding msgelem contains %d non-0xFF byte(s) out of %d, See RFC 5415.",
+		       n, len);
+	return 1;
+}

src/capwap/cwread_discovery_request.c

@@ -61,6 +61,11 @@ static int wtpinfo_readelem_discovery_req(void *eparm, int type,
 	    (e->wtpinfo, type, msgelem, len))
 		goto foundX;
 
+	/* non-mandatory mesage lements */
+	if (cw_readelem_mtu_discovery_padding(type,msgelem,len))
+		return 1;
+	
+
 	return 0;
       foundX:
 	cw_mand_elem_found(e->mand, type);