socket: Add s_aux field to struct socket for storing auxilliary socket

Signed-off-by: Nicholas Ngai <nicholas@ngai.me>

4 files changed, 11 insertions, 2 deletions

diff --git a/src/socket.c b/src/socket.c
index 7869e6a..a92cfd3 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -50,6 +50,7 @@ struct socket *socreate(Slirp *slirp)
     memset(so, 0, sizeof(struct socket));
     so->so_state = SS_NOFDREF;
     so->s = -1;
+    so->s_aux = -1;
     so->slirp = slirp;
     so->pollfds_idx = -1;
 
@@ -1098,7 +1099,7 @@ void sotranslate_accept(struct socket *so)
                 closesocket(s);
                 goto unix2inet_cont;
             }
-            so->s = s;
+            so->s_aux = s;
             so->so_fport = in_addr.sin_port;
 
 unix2inet_cont:
@@ -1132,7 +1133,7 @@ unix2inet_cont:
                 closesocket(s);
                 goto unix2inet6_cont;
             }
-            so->s = s;
+            so->s_aux = s;
             so->so_fport6 = in6_addr.sin6_port;
 
 unix2inet6_cont:
diff --git a/src/socket.h b/src/socket.h
index 17901ad..ac77c5e 100644
--- a/src/socket.h
+++ b/src/socket.h
@@ -40,6 +40,8 @@ struct socket {
     struct socket *so_next, *so_prev; /* For a linked list of sockets */
 
     int s; /* The actual socket */
+    int s_aux; /* An auxiliary socket for miscellaneous use. Currently used to
+                * reserve OS ports in UNIX-to-inet translation. */
     struct gfwd_list *guestfwd;
 
     int pollfds_idx; /* GPollFD GArray index */
diff --git a/src/tcp_subr.c b/src/tcp_subr.c
index 7c63f49..d1a95f0 100644
--- a/src/tcp_subr.c
+++ b/src/tcp_subr.c
@@ -339,6 +339,9 @@ struct tcpcb *tcp_close(struct tcpcb *tp)
         slirp->tcp_last_so = &slirp->tcb;
     so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque);
     closesocket(so->s);
+    if (so->s_aux != -1) {
+        closesocket(so->s_aux);
+    }
     sbfree(&so->so_rcv);
     sbfree(&so->so_snd);
     sofree(so);
diff --git a/src/udp.c b/src/udp.c
index 06b7b7d..48bd8ae 100644
--- a/src/udp.c
+++ b/src/udp.c
@@ -339,6 +339,9 @@ void udp_detach(struct socket *so)
 {
     so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque);
     closesocket(so->s);
+    if (so->s_aux != -1) {
+        closesocket(so->s_aux);
+    }
     sofree(so);
 }