[Qemu-devel] Patch for adding custom hardware address in -net user, macaddr=

[James Jarvis]

Dear Qemu-Dev list,

Find attached a patch against the 0.9.1 code base to allow the addition 
of a macaddr in -net user mode. This feature is unlikely to be widely 
used, but we had a requirement for it when using qemu for testing. The 
patch has been tested in i386 mode only.

In the dev tree much code has been moved out of vl.c - not sure how keen 
you are to see this patch in there too but it would be a feature 
appreciated by some. :-)

Regards,

James Jarvis
Information Services
The University of Edinburgh

--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.

--- qemu-0.9.1-orig/vl.c        2008-01-06 19:38:42.000000000 +0000
+++ qemu-0.9.1/vl.c     2009-01-19 15:56:32.000000000 +0000
@@ -4729,7 +4729,35 @@
         if (get_param_value(buf, sizeof(buf), "hostname", p)) {
             pstrcpy(slirp_hostname, sizeof(slirp_hostname), buf);
         }
-        vlan->nb_host_devs++;
+        /*** BEGIN - Allow mac to be set in NAT ***/
+        NICInfo *nd;
+        uint8_t *macaddr;
+
+        if (nb_nics >= MAX_NICS) {
+            fprintf(stderr, "Too Many NICs\n");
+            return -1;
+        }
+        nd = &nd_table[nb_nics];
+        macaddr = nd->macaddr;
+        macaddr[0] = 0x52;
+        macaddr[1] = 0x54;
+        macaddr[2] = 0x00;
+        macaddr[3] = 0x12;
+        macaddr[4] = 0x34;
+        macaddr[5] = 0x56 + nb_nics;
+
+        if (get_param_value(buf, sizeof(buf), "macaddr", p)) {
+            if (parse_macaddr(macaddr, buf) < 0) {
+                fprintf(stderr, "invalid syntax for ethernet address\n");
+                return -1;
+            }
+           nd->vlan = vlan;
+           nb_nics++;
+           vlan->nb_guest_devs++;
+        }else {
+         /*** END - Allow mac to be set in NAT ***/
+         vlan->nb_host_devs++;
+       }
         ret = net_slirp_init(vlan);
     } else
 #endif
@@ -7547,7 +7575,7 @@
            "-net nic[,vlan=n][,macaddr=addr][,model=type]\n"
            "                create a new Network Interface Card and connect it 
to VLAN 'n'\n"
 #ifdef CONFIG_SLIRP
-           "-net user[,vlan=n][,hostname=host]\n"
+           "-net user[,vlan=n][,macaddr=addr][,hostname=host]\n"
            "                connect the user mode network stack to VLAN 'n' 
and send\n"
            "                hostname 'host' to DHCP clients\n"
 #endif