slirp: Propagate host TCP RST to the guest.

When the host aborts (RST) its side of a TCP connection we need to
propagate that RST to the guest. The current code can leave such guest
connections dangling forever. Spotted by Jason Wessel.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
[steven@steven676.net: coding style adjustments]
Signed-off-by: Steven Luo <steven+qemu@steven676.net>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/socket.c b/socket.c
index 48d6b77..ee87a77 100644
--- a/socket.c
+++ b/socket.c
@@ -175,11 +175,24 @@ int soread(struct socket *so)
         if (nn < 0 && (errno == EINTR || errno == EAGAIN))
             return 0;
         else {
+            int err;
+            socklen_t slen = sizeof err;
+
+            err = errno;
+            if (nn == 0) {
+                getsockopt(so->s, SOL_SOCKET, SO_ERROR, &err, &slen);
+            }
+
             DEBUG_MISC((dfd,
                         " --- soread() disconnected, nn = %d, errno = %d-%s\n",
                         nn, errno, strerror(errno)));
             sofcantrcvmore(so);
-            tcp_sockclosed(sototcpcb(so));
+
+            if (err == ECONNRESET || err == ENOTCONN || err == EPIPE) {
+                tcp_drop(sototcpcb(so), err);
+            } else {
+                tcp_sockclosed(sototcpcb(so));
+            }
             return -1;
         }
     }