[3551] Minor changes after review.

src/lib/dhcp/pkt.cc

@@ -156,10 +156,10 @@ Pkt::getMAC(uint32_t hw_addr_src) {
 
     // Method 4: From client link-layer address option inserted by a relay
     if (hw_addr_src & HWADDR_SOURCE_CLIENT_ADDR_RELAY_OPTION) {
-		mac = getMACFromIPv6RelayOpt();
-		if (mac) {
-			return (mac);
-		} else if (hw_addr_src ==  HWADDR_SOURCE_CLIENT_ADDR_RELAY_OPTION) {
+        mac = getMACFromIPv6RelayOpt();
+        if (mac) {
+            return (mac);
+        } else if (hw_addr_src ==  HWADDR_SOURCE_CLIENT_ADDR_RELAY_OPTION) {
             // If we're interested only in RFC6939 link layer address as source
             // of that info, there's no point in trying other options.
             return (HWAddrPtr());

src/lib/dhcp/pkt.h

@@ -529,8 +529,8 @@ protected:
     ///
     /// This method is called from getMAC(HWADDR_SOURCE_CLIENT_ADDR_RELAY_OPTION)
     /// and should not be called directly. It will extract the client's
-    //  MAC/Hardware address from option client_linklayer_addr (RFC6939)
-    //  inserted by the relay agent closest to the client.
+    /// MAC/Hardware address from option client_linklayer_addr (RFC6939)
+    /// inserted by the relay agent closest to the client.
     /// If this method fails, it will return NULL.
     ///
     /// @note This is a pure virtual method and must be implemented in

src/lib/dhcp/pkt6.cc

@@ -16,6 +16,7 @@
 #include <dhcp/libdhcp++.h>
 #include <dhcp/option.h>
 #include <dhcp/pkt6.h>
+#include <util/io_utilities.h>
 #include <exceptions/exceptions.h>
 
 #include <iostream>
@@ -556,18 +557,26 @@ Pkt6::getMACFromSrcLinkLocalAddr() {
 HWAddrPtr
 Pkt6::getMACFromIPv6RelayOpt() {
     if (relay_info_.empty()) {
-    	// This is a direct message
+        // This is a direct message
         return (HWAddrPtr());
     }
     // RFC6969 Section 6: Look for the client_linklayer_addr option on the
     // relay agent closest to the client
     OptionPtr opt = getAnyRelayOption(D6O_CLIENT_LINKLAYER_ADDR, RELAY_GET_FIRST);
     if (opt) {
-    	return (HWAddrPtr(new HWAddr(&(opt->getData())[2], (opt->len()-opt->getHeaderLen()-2),
-    			                      opt->getUint16())));
+        const OptionBuffer data = opt->getData();
+        if (data.size() < 3) {
+            // This client link address option is trucnated. It's supposed to be
+            // 2 bytes of link-layer type followed by link-layer address.
+            return (HWAddrPtr());
+        }
+
+        // +2, -2 means to skip the initial 2 bytes which are hwaddress type
+        return (HWAddrPtr(new HWAddr(&data[0] + 2, data.size() - 2,
+                                     opt->getUint16())));
     }
     else {
-    	return (HWAddrPtr());
+        return (HWAddrPtr());
     }
 }
 

src/lib/dhcp/tests/pkt6_unittest.cc

@@ -1064,7 +1064,7 @@ TEST_F(Pkt6Test, getMACFromIPv6RelayOpt_singleRelay) {
     Pkt6::RelayInfo info;
 
     // generate options with code 79 and client link layer address
-    const char opt_data[] = {
+    const uint8_t opt_data[] = {
         0x00, 0x01,  // Ethertype
         0x0a, 0x1b, 0x0b, 0x01, 0xca, 0xfe // MAC
     };
@@ -1093,11 +1093,11 @@ TEST_F(Pkt6Test, getMACFromIPv6RelayOpt_multipleRelay) {
     // Now pretend it was relayed two times. The relay closest to the server
     // adds link-layer-address information against the RFC, the process fails.
     Pkt6::RelayInfo info1;
-    char opt_data[] = {
+    uint8_t opt_data[] = {
         0x00, 0x01,  // Ethertype
         0x1a, 0x30, 0x0b, 0xfa, 0xc0, 0xfe // MAC
     };
-    OptionPtr relay_opt1(new Option(Option::V6, 79,
+    OptionPtr relay_opt1(new Option(Option::V6, D6O_CLIENT_LINKLAYER_ADDR,
     		            OptionBuffer(opt_data, opt_data + sizeof(opt_data))));
 
     info1.options_.insert(make_pair(relay_opt1->getType(), relay_opt1));
@@ -1113,9 +1113,10 @@ TEST_F(Pkt6Test, getMACFromIPv6RelayOpt_multipleRelay) {
     // Let's envolve the packet with a third relay (now the closest to the client)
     // that inserts the correct client_linklayer_addr option.
     Pkt6::RelayInfo info3;
+
     // We reuse the option and modify the MAC to be sure we get the right address
     opt_data[2] = 0xfa;
-    OptionPtr relay_opt3(new Option(Option::V6, 79,
+    OptionPtr relay_opt3(new Option(Option::V6, D6O_CLIENT_LINKLAYER_ADDR,
     		            OptionBuffer(opt_data, opt_data + sizeof(opt_data))));
     info3.options_.insert(make_pair(relay_opt3->getType(), relay_opt3));
     pkt.addRelayInfo(info3);