slirp: Rework internal configuration

The user mode IP stack is currently only minimally configurable /wrt to
its virtual IP addresses. This is unfortunate if some guest has a fixed
idea of which IP addresses to use.

Therefore this patch prepares the stack for fully configurable IP
addresses and masks. The user interface and default addresses remain
untouched in this step, they will be enhanced in the following patch.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 6 insertions, 9 deletions

diff --git a/slirp/ip_icmp.c b/slirp/ip_icmp.c
index 61dcaf821b..6e93ee3eb4 100644
--- a/slirp/ip_icmp.c
+++ b/slirp/ip_icmp.c
@@ -110,7 +110,7 @@ icmp_input(struct mbuf *m, int hlen)
   case ICMP_ECHO:
     icp->icmp_type = ICMP_ECHOREPLY;
     ip->ip_len += hlen;	             /* since ip_input subtracts this */
-    if (ip->ip_dst.s_addr == alias_addr.s_addr) {
+    if (ip->ip_dst.s_addr == vhost_addr.s_addr) {
       icmp_reflect(m);
     } else {
       struct socket *so;
@@ -134,16 +134,13 @@ icmp_input(struct mbuf *m, int hlen)
 
       /* Send the packet */
       addr.sin_family = AF_INET;
-      if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
+      if ((so->so_faddr.s_addr & vnetwork_mask.s_addr) ==
+          vnetwork_addr.s_addr) {
 	/* It's an alias */
-	switch(ntohl(so->so_faddr.s_addr) & 0xff) {
-	case CTL_DNS:
+	if (so->so_faddr.s_addr == vnameserver_addr.s_addr) {
 	  addr.sin_addr = dns_addr;
-	  break;
-	case CTL_ALIAS:
-	default:
+	} else {
 	  addr.sin_addr = loopback_addr;
-	  break;
 	}
       } else {
 	addr.sin_addr = so->so_faddr;
@@ -302,7 +299,7 @@ icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
   ip->ip_ttl = MAXTTL;
   ip->ip_p = IPPROTO_ICMP;
   ip->ip_dst = ip->ip_src;    /* ip adresses */
-  ip->ip_src = alias_addr;
+  ip->ip_src = vhost_addr;
 
   (void ) ip_output((struct socket *)NULL, m);