linux-user,netlink: fix message translation with ip command

With iproute2-5.8.0, the route, link and addr show commands fail:

  root@sid:~# ip addr show
  RTNETLINK answers: Unknown error 352321537
  Dump terminated
  root@sid:~# ip link show
  RTNETLINK answers: Unknown error 352321537
  Dump terminated
  root@sid:~# ip route show
  RTNETLINK answers: Unknown error 352321537
  Dump terminated

This patch correctly decodes the GETROUTE and GETLINK commands and adds
the RTA_TABLE message.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20201116163622.791442-1-laurent@vivier.eu>
diff --git a/linux-user/fd-trans.c b/linux-user/fd-trans.c
index 1486c81..7551c88 100644
--- a/linux-user/fd-trans.c
+++ b/linux-user/fd-trans.c
@@ -1160,6 +1160,7 @@
         break;
     /* u32 */
     case QEMU_RTA_PRIORITY:
+    case QEMU_RTA_TABLE:
     case QEMU_RTA_OIF:
         u32 = RTA_DATA(rtattr);
         *u32 = tswap32(*u32);
@@ -1200,11 +1201,10 @@
     struct rtmsg *rtm;
 
     switch (nlh->nlmsg_type) {
-    case RTM_GETLINK:
-        break;
     case RTM_NEWLINK:
     case RTM_DELLINK:
     case RTM_SETLINK:
+    case RTM_GETLINK:
         if (nlh->nlmsg_len >= NLMSG_LENGTH(sizeof(*ifi))) {
             ifi = NLMSG_DATA(nlh);
             ifi->ifi_type = tswap16(ifi->ifi_type);
@@ -1225,10 +1225,9 @@
                                        NLMSG_LENGTH(sizeof(*ifa)));
         }
         break;
-    case RTM_GETROUTE:
-        break;
     case RTM_NEWROUTE:
     case RTM_DELROUTE:
+    case RTM_GETROUTE:
         if (nlh->nlmsg_len >= NLMSG_LENGTH(sizeof(*rtm))) {
             rtm = NLMSG_DATA(nlh);
             rtm->rtm_flags = tswap32(rtm->rtm_flags);