1 files changed, 39 insertions, 21 deletions

diff --git a/slirp/if.c b/slirp/if.c
index f7aebe9557..f6e848a31a 100644
--- a/slirp/if.c
+++ b/slirp/if.c
@@ -158,8 +158,8 @@ void if_start(Slirp *slirp)
 {
     uint64_t now = qemu_get_clock_ns(rt_clock);
     int requeued = 0;
-    bool from_batchq = false;
-    struct mbuf *ifm, *ifqt;
+    bool from_batchq, next_from_batchq;
+    struct mbuf *ifm, *ifm_next, *ifqt;
 
     DEBUG_CALL("if_start");
 
@@ -168,23 +168,36 @@ void if_start(Slirp *slirp)
     }
     slirp->if_start_busy = true;
 
-    while (slirp->if_queued) {
+    if (slirp->if_fastq.ifq_next != &slirp->if_fastq) {
+        ifm_next = slirp->if_fastq.ifq_next;
+        next_from_batchq = false;
+    } else if (slirp->next_m != &slirp->if_batchq) {
+        /* Nothing on fastq, pick up from batchq via next_m */
+        ifm_next = slirp->next_m;
+        next_from_batchq = true;
+    } else {
+        ifm_next = NULL;
+    }
+
+    while (ifm_next) {
         /* check if we can really output */
         if (!slirp_can_output(slirp->opaque)) {
             slirp->if_start_busy = false;
             return;
         }
 
-        /*
-         * See which queue to get next packet from
-         * If there's something in the fastq, select it immediately
-         */
-        if (slirp->if_fastq.ifq_next != &slirp->if_fastq) {
-            ifm = slirp->if_fastq.ifq_next;
-        } else {
-            /* Nothing on fastq, pick up from batchq via next_m */
-            ifm = slirp->next_m;
-            from_batchq = true;
+        ifm = ifm_next;
+        from_batchq = next_from_batchq;
+
+        ifm_next = ifm->ifq_next;
+        if (ifm_next == &slirp->if_fastq) {
+            /* No more packets in fastq, switch to batchq */
+            ifm_next = slirp->next_m;
+            next_from_batchq = true;
+        }
+        if (ifm_next == &slirp->if_batchq) {
+            /* end of batchq */
+            ifm_next = NULL;
         }
 
         slirp->if_queued--;
@@ -196,7 +209,7 @@ void if_start(Slirp *slirp)
             continue;
         }
 
-        if (from_batchq) {
+        if (ifm == slirp->next_m) {
             /* Set which packet to send on next iteration */
             slirp->next_m = ifm->ifq_next;
         }
@@ -207,13 +220,19 @@ void if_start(Slirp *slirp)
 
         /* If there are more packets for this session, re-queue them */
         if (ifm->ifs_next != ifm) {
-            insque(ifm->ifs_next, ifqt);
+            struct mbuf *next = ifm->ifs_next;
+
+            insque(next, ifqt);
             ifs_remque(ifm);
-            /* Set next_m if the session packet is now the only one on
-             * batchq */
-            if (ifqt == &slirp->if_batchq &&
-                slirp->next_m == &slirp->if_batchq) {
-                slirp->next_m = ifm->ifs_next;
+
+            if (!from_batchq) {
+                /* Next packet in fastq is from the same session */
+                ifm_next = next;
+                next_from_batchq = false;
+            } else if (slirp->next_m == &slirp->if_batchq) {
+                /* Set next_m and ifm_next if the session packet is now the
+                 * only one on batchq */
+                slirp->next_m = ifm_next = next;
             }
         }
 
@@ -224,7 +243,6 @@ void if_start(Slirp *slirp)
         }
 
         m_free(ifm);
-
     }
 
     slirp->if_queued = requeued;