Add --add-mac=text option.

man/dnsmasq.8

@@ -604,7 +604,7 @@ configured a zero is added in front of the label. ::1 becomes 0--1.
 The address range can be of the form
 <ip address>,<ip address> or <ip address>/<netmask>
 .TP
-.B --add-mac[=base64]
+.B --add-mac[=base64|text]
 Add the MAC address of the requestor to DNS queries which are
 forwarded upstream. This may be used to DNS filtering by the upstream
 server. The MAC address can only be added if the requestor is on the same
@@ -613,7 +613,7 @@ is not yet standardised, so this should be considered
 experimental. Also note that exposing MAC addresses in this way may
 have security and privacy implications. The warning about caching
 given for --add-subnet applies to --add-mac too. An alternative encoding of the 
-MAC, as base64, is enabled by adding the "base64" parameter.
+MAC, as base64, is enabled by adding the "base64" parameter and a human-readable encoding of hex-and-colons is enabled by added the "text" parameter.
 .TP
 .B --add-cpe-id=<string>
 Add a arbitrary identifying string to o DNS queries which are

src/dnsmasq.h

@@ -237,7 +237,8 @@ struct event_desc {
 #define OPT_TFTP_NO_FAIL   52
 #define OPT_SCRIPT_ARP     53
 #define OPT_MAC_B64        54
-#define OPT_LAST           55
+#define OPT_MAC_HEX        55
+#define OPT_LAST           56
 
 /* extra flags for my_syslog, we use a couple of facilities since they are known 
    not to occupy the same bits as priorities, no matter how syslog.h is set up. */

src/edns0.c

@@ -223,14 +223,19 @@ static size_t add_dns_client(struct dns_header *header, size_t plen, unsigned ch
 {
   int maclen;
   unsigned char mac[DHCP_CHADDR_MAX];
-  char encode[8]; /* handle 6 byte MACs */
+  char encode[18]; /* handle 6 byte MACs */
 
   if ((maclen = find_mac(l3, mac, 1, now)) == 6)
     {
-      encoder(mac, encode);
-      encoder(mac+3, encode+4);
-      
-      plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_NOMDEVICEID, (unsigned char *)encode, 8, 0); 
+      if (option_bool(OPT_MAC_HEX))
+	print_mac(encode, mac, maclen);
+      else
+	{
+	  encoder(mac, encode);
+	  encoder(mac+3, encode+4);
+	  encode[8] = 0;
+	}
+      plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_NOMDEVICEID, (unsigned char *)encode, strlen(encode), 0); 
     }
 
   return plen; 
@@ -377,7 +382,7 @@ size_t add_edns0_config(struct dns_header *header, size_t plen, unsigned char *l
   if (option_bool(OPT_ADD_MAC))
     plen  = add_mac(header, plen, limit, source, now);
   
-  if (option_bool(OPT_MAC_B64))
+  if (option_bool(OPT_MAC_B64) || option_bool(OPT_MAC_HEX))
     plen = add_dns_client(header, plen, limit, source, now);
 
   if (daemon->dns_client_id)

src/option.c

@@ -2172,8 +2172,9 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	  unhide_metas(arg);
 	  if (strcmp(arg, "base64") == 0)
 	    set_option_bool(OPT_MAC_B64);
-	  else
-	    ret_err(gen_err);
+	  else if (strcmp(arg, "text") == 0)
+	    set_option_bool(OPT_MAC_HEX);
+	  ret_err(gen_err);
 	}
       break;