slirp: Do not allow to remove non-hostfwd sockets

Prevent that the users accidentally shoots down dynamic sockets. This
allows to remove looping for removals as there can now only be one
match.

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

2 files changed, 9 insertions, 13 deletions

diff --git a/net.c b/net.c
index ee321ab47f..603e77cae8 100644
--- a/net.c
+++ b/net.c
@@ -880,7 +880,7 @@ void net_slirp_hostfwd_remove(Monitor *mon, const char *src_str)
     char buf[256] = "";
     const char *p = src_str;
     int is_udp = 0;
-    int n;
+    int err;
 
     if (!slirp_inited) {
         monitor_printf(mon, "user mode network stack not in use\n");
@@ -909,10 +909,10 @@ void net_slirp_hostfwd_remove(Monitor *mon, const char *src_str)
 
     host_port = atoi(p);
 
-    n = slirp_remove_hostfwd(is_udp, host_addr, host_port);
+    err = slirp_remove_hostfwd(is_udp, host_addr, host_port);
 
-    monitor_printf(mon, "removed %d host forwarding rules for %s\n", n,
-                   src_str);
+    monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
+                   err ? "removed" : "not found");
     return;
 
  fail_syntax:
diff --git a/slirp/slirp.c b/slirp/slirp.c
index ad35c1fb24..35de4e380b 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -757,9 +757,7 @@ void if_encap(const uint8_t *ip_data, int ip_data_len)
     }
 }
 
-/* Unlistens a redirection
- *
- * Return value: number of redirs removed */
+/* Drop host forwarding rule, return 0 if found. */
 int slirp_remove_hostfwd(int is_udp, struct in_addr host_addr, int host_port)
 {
     struct socket *so;
@@ -767,22 +765,20 @@ int slirp_remove_hostfwd(int is_udp, struct in_addr host_addr, int host_port)
     struct sockaddr_in addr;
     int port = htons(host_port);
     socklen_t addr_len;
-    int n = 0;
 
- loop_again:
     for (so = head->so_next; so != head; so = so->so_next) {
         addr_len = sizeof(addr);
-        if (getsockname(so->s, (struct sockaddr *)&addr, &addr_len) == 0 &&
+        if ((so->so_state & SS_HOSTFWD) &&
+            getsockname(so->s, (struct sockaddr *)&addr, &addr_len) == 0 &&
             addr.sin_addr.s_addr == host_addr.s_addr &&
             addr.sin_port == port) {
             close(so->s);
             sofree(so);
-            n++;
-            goto loop_again;
+            return 0;
         }
     }
 
-    return n;
+    return -1;
 }
 
 int slirp_add_hostfwd(int is_udp, struct in_addr host_addr, int host_port,