[Qemu-devel] [PULL 3/4] slirp: Handle error returns from slirp_send() in sosendoob()

[Samuel Thibault]

From: Peter Maydell <address@hidden>

The code in sosendoob() assumes that slirp_send() always
succeeds, but it might return an OS error code (for instance
if the other end has disconnected). Catch these and return
the caller either -1 on error or the number of urgent bytes
actually written. (None of the callers check this return
value currently, though.)

Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
Signed-off-by: Samuel Thibault <address@hidden>
---
 slirp/socket.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/slirp/socket.c b/slirp/socket.c
index 3b49a69a93..a17caa9fa7 100644
--- a/slirp/socket.c
+++ b/slirp/socket.c
@@ -345,33 +345,40 @@ sosendoob(struct socket *so)
        if (sb->sb_rptr < sb->sb_wptr) {
                /* We can send it directly */
                n = slirp_send(so, sb->sb_rptr, so->so_urgc, (MSG_OOB)); /* 
|MSG_DONTWAIT)); */
-               so->so_urgc -= n;
-
-               DEBUG_MISC((dfd, " --- sent %d bytes urgent data, %d urgent 
bytes left\n", n, so->so_urgc));
        } else {
                /*
                 * Since there's no sendv or sendtov like writev,
                 * we must copy all data to a linear buffer then
                 * send it all
                 */
+               uint32_t urgc = so->so_urgc;
                len = (sb->sb_data + sb->sb_datalen) - sb->sb_rptr;
-               if (len > so->so_urgc) len = so->so_urgc;
+               if (len > urgc) {
+                       len = urgc;
+               }
                memcpy(buff, sb->sb_rptr, len);
-               so->so_urgc -= len;
-               if (so->so_urgc) {
+               urgc -= len;
+               if (urgc) {
                        n = sb->sb_wptr - sb->sb_data;
-                       if (n > so->so_urgc) n = so->so_urgc;
+                       if (n > urgc) {
+                               n = urgc;
+                       }
                        memcpy((buff + len), sb->sb_data, n);
-                       so->so_urgc -= n;
                        len += n;
                }
                n = slirp_send(so, buff, len, (MSG_OOB)); /* |MSG_DONTWAIT)); */
+       }
+
 #ifdef DEBUG
-               if (n != len)
-                  DEBUG_ERROR((dfd, "Didn't send all data urgently XXXXX\n"));
+       if (n != len) {
+               DEBUG_ERROR((dfd, "Didn't send all data urgently XXXXX\n"));
+       }
 #endif
-               DEBUG_MISC((dfd, " ---2 sent %d bytes urgent data, %d urgent 
bytes left\n", n, so->so_urgc));
+       if (n < 0) {
+               return n;
        }
+       so->so_urgc -= n;
+       DEBUG_MISC((dfd, " ---2 sent %d bytes urgent data, %d urgent bytes 
left\n", n, so->so_urgc));
 
        sb->sb_cc -= n;
        sb->sb_rptr += n;
-- 
2.13.2