commit 953e7f54e679cd40fff28e29189ed9e24bfb0758
author Jan Kiszka <jan.kiszka@siemens.com> Mon Mar 05 19:50:39 2012 +0100
committer Jan Kiszka <jan.kiszka@siemens.com> Tue Mar 13 14:05:48 2012 +0100
tree 3b1632e6352987c9370546509564f177c51983a1
parent d6536b2c971f7323e58dfbe1e6f3b7c7c0c4edf3

slirp: Prevent recursion of if_start

if_start can be called recursively via if_encap. Avoid this as our
scheme of dequeuing packets is not compatible with this.

CC: Fabien Chouteau <chouteau@adacore.com>
CC: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
CC: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

slirp/if.c

diff --git a/slirp/if.c b/slirp/if.c
index 14fdef1..f7aebe9 100644
--- a/slirp/if.c
+++ b/slirp/if.c
@@ -163,10 +163,17 @@
 
     DEBUG_CALL("if_start");
 
+    if (slirp->if_start_busy) {
+        return;
+    }
+    slirp->if_start_busy = true;
+
     while (slirp->if_queued) {
         /* check if we can really output */
-        if (!slirp_can_output(slirp->opaque))
+        if (!slirp_can_output(slirp->opaque)) {
+            slirp->if_start_busy = false;
             return;
+        }
 
         /*
          * See which queue to get next packet from
@@ -221,4 +228,6 @@
     }
 
     slirp->if_queued = requeued;
+
+    slirp->if_start_busy = false;
 }