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authorJan Kiszka <jan.kiszka@siemens.com>2012-02-17 16:26:38 +0100
committerJan Kiszka <jan.kiszka@siemens.com>2012-02-27 14:54:49 +0100
commitb248ede2ef2792d364bd305e5e92e24921c924a8 (patch)
tree4bd6012bdbd243fcd432d4dfae2e75a64c19facd /slirp
parent79e7e937bd59ba8c4caaa08963712df2506adf8b (diff)
downloadqemu-arm-b248ede2ef2792d364bd305e5e92e24921c924a8.tar.gz
slirp: Fix requeuing of batchq packets in if_start
In case we requeued a packet that was the head of a longer session queue, we failed to restore this ordering. Also, we did not properly deal with changes to Slirp::next_m. Instead of a cumbersome roll back, this fix simply avoids any changes until we know if the packet was actually sent. Both fixes crashes due to inconsistent queues and simplifies the logic. Thanks to Zhi Yong Wu who found the reason for these crashes. CC: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> CC: Fabien Chouteau <chouteau@adacore.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Diffstat (limited to 'slirp')
-rw-r--r--slirp/if.c35
1 files changed, 19 insertions, 16 deletions
diff --git a/slirp/if.c b/slirp/if.c
index 8e0cac2a5b..710ec230e6 100644
--- a/slirp/if.c
+++ b/slirp/if.c
@@ -154,6 +154,7 @@ if_start(Slirp *slirp)
{
uint64_t now = qemu_get_clock_ns(rt_clock);
int requeued = 0;
+ bool from_batchq = false;
struct mbuf *ifm, *ifqt;
DEBUG_CALL("if_start");
@@ -179,13 +180,26 @@ if_start(Slirp *slirp)
else
ifm = slirp->if_batchq.ifq_next;
- /* Set which packet to send on next iteration */
- slirp->next_m = ifm->ifq_next;
+ from_batchq = true;
}
+
+ slirp->if_queued--;
+
+ /* Try to send packet unless it already expired */
+ if (ifm->expiration_date >= now && !if_encap(slirp, ifm)) {
+ /* Packet is delayed due to pending ARP resolution */
+ requeued++;
+ goto out;
+ }
+
+ if (from_batchq) {
+ /* Set which packet to send on next iteration */
+ slirp->next_m = ifm->ifq_next;
+ }
+
/* Remove it from the queue */
ifqt = ifm->ifq_prev;
remque(ifm);
- slirp->if_queued--;
/* If there are more packets for this session, re-queue them */
if (ifm->ifs_next != /* ifm->ifs_prev != */ ifm) {
@@ -200,20 +214,9 @@ if_start(Slirp *slirp)
ifm->ifq_so->so_nqueued = 0;
}
- if (ifm->expiration_date < now) {
- /* Expired */
- m_free(ifm);
- } else {
- /* Encapsulate the packet for sending */
- if (if_encap(slirp, ifm)) {
- m_free(ifm);
- } else {
- /* re-queue */
- insque(ifm, ifqt);
- requeued++;
- }
- }
+ m_free(ifm);
+ out:
if (slirp->if_queued)
goto again;