net: split out packet queueing and flushing into separate functions

We'll be doing more packet queueing in later commits.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

net.c

@@ -415,6 +415,8 @@ qemu_deliver_packet(VLANClientState *sender, const uint8_t *buf, int size)
     VLANClientState *vc;
     int ret = -1;
 
+    sender->vlan->delivering = 1;
+
     for (vc = sender->vlan->first_client; vc != NULL; vc = vc->next) {
         ssize_t len;
 
@@ -432,13 +434,38 @@ qemu_deliver_packet(VLANClientState *sender, const uint8_t *buf, int size)
         ret = (ret >= 0) ? ret : len;
     }
 
+    sender->vlan->delivering = 0;
+
     return ret;
 }
 
+static void qemu_flush_queued_packets(VLANClientState *vc)
+{
+    VLANPacket *packet;
+
+    while ((packet = vc->vlan->send_queue) != NULL) {
+        vc->vlan->send_queue = packet->next;
+        qemu_deliver_packet(packet->sender, packet->data, packet->size);
+        qemu_free(packet);
+    }
+}
+
+static void
+qemu_enqueue_packet(VLANClientState *sender, const uint8_t *buf, int size)
+{
+    VLANPacket *packet;
+
+    packet = qemu_malloc(sizeof(VLANPacket) + size);
+    packet->next = sender->vlan->send_queue;
+    packet->sender = sender;
+    packet->size = size;
+    memcpy(packet->data, buf, size);
+    sender->vlan->send_queue = packet;
+}
+
 void qemu_send_packet(VLANClientState *vc, const uint8_t *buf, int size)
 {
     VLANState *vlan = vc->vlan;
-    VLANPacket *packet;
 
     if (vc->link_down)
         return;
@@ -448,22 +475,12 @@ void qemu_send_packet(VLANClientState *vc, const uint8_t *buf, int size)
     hex_dump(stdout, buf, size);
 #endif
     if (vlan->delivering) {
-        packet = qemu_malloc(sizeof(VLANPacket) + size);
-        packet->next = vlan->send_queue;
-        packet->sender = vc;
-        packet->size = size;
-        memcpy(packet->data, buf, size);
-        vlan->send_queue = packet;
-    } else {
-        vlan->delivering = 1;
-        qemu_deliver_packet(vc, buf, size);
-        while ((packet = vlan->send_queue) != NULL) {
-            vlan->send_queue = packet->next;
-            qemu_deliver_packet(packet->sender, packet->data, packet->size);
-            qemu_free(packet);
-        }
-        vlan->delivering = 0;
+        qemu_enqueue_packet(vc, buf, size);
+        return;
     }
+
+    qemu_deliver_packet(vc, buf, size);
+    qemu_flush_queued_packets(vc);
 }
 
 static ssize_t vc_sendv_compat(VLANClientState *vc, const struct iovec *iov,
@@ -496,60 +513,84 @@ static ssize_t calc_iov_length(const struct iovec *iov, int iovcnt)
     return offset;
 }
 
+static int qemu_deliver_packet_iov(VLANClientState *sender,
+                                   const struct iovec *iov, int iovcnt)
+{
+    VLANClientState *vc;
+    int ret = -1;
+
+    sender->vlan->delivering = 1;
+
+    for (vc = sender->vlan->first_client; vc != NULL; vc = vc->next) {
+        ssize_t len;
+
+        if (vc == sender) {
+            continue;
+        }
+
+        if (vc->link_down) {
+            ret = calc_iov_length(iov, iovcnt);
+            continue;
+        }
+
+        if (vc->receive_iov) {
+            len = vc->receive_iov(vc, iov, iovcnt);
+        } else {
+            len = vc_sendv_compat(vc, iov, iovcnt);
+        }
+
+        ret = (ret >= 0) ? ret : len;
+    }
+
+    sender->vlan->delivering = 0;
+
+    return ret;
+}
+
+static ssize_t qemu_enqueue_packet_iov(VLANClientState *sender,
+                                       const struct iovec *iov, int iovcnt)
+{
+    VLANPacket *packet;
+    size_t max_len = 0;
+    int i;
+
+    max_len = calc_iov_length(iov, iovcnt);
+
+    packet = qemu_malloc(sizeof(VLANPacket) + max_len);
+    packet->next = sender->vlan->send_queue;
+    packet->sender = sender;
+    packet->size = 0;
+
+    for (i = 0; i < iovcnt; i++) {
+        size_t len = iov[i].iov_len;
+
+        memcpy(packet->data + packet->size, iov[i].iov_base, len);
+        packet->size += len;
+    }
+
+    sender->vlan->send_queue = packet;
+
+    return packet->size;
+}
+
 ssize_t qemu_sendv_packet(VLANClientState *sender, const struct iovec *iov,
                           int iovcnt)
 {
-    VLANState *vlan = sender->vlan;
-    VLANClientState *vc;
-    VLANPacket *packet;
-    ssize_t max_len = 0;
-    int i;
+    int ret;
 
-    if (sender->link_down)
+    if (sender->link_down) {
         return calc_iov_length(iov, iovcnt);
-
-    if (vlan->delivering) {
-        max_len = calc_iov_length(iov, iovcnt);
-
-        packet = qemu_malloc(sizeof(VLANPacket) + max_len);
-        packet->next = vlan->send_queue;
-        packet->sender = sender;
-        packet->size = 0;
-        for (i = 0; i < iovcnt; i++) {
-            size_t len = iov[i].iov_len;
-
-            memcpy(packet->data + packet->size, iov[i].iov_base, len);
-            packet->size += len;
-        }
-        vlan->send_queue = packet;
-    } else {
-        vlan->delivering = 1;
-
-        for (vc = vlan->first_client; vc != NULL; vc = vc->next) {
-            ssize_t len = 0;
-
-            if (vc == sender) {
-                continue;
-            }
-            if (vc->link_down) {
-                len = calc_iov_length(iov, iovcnt);
-            } else if (vc->receive_iov) {
-                len = vc->receive_iov(vc, iov, iovcnt);
-            } else if (vc->receive) {
-                len = vc_sendv_compat(vc, iov, iovcnt);
-            }
-            max_len = MAX(max_len, len);
-        }
-
-        while ((packet = vlan->send_queue) != NULL) {
-            vlan->send_queue = packet->next;
-            qemu_deliver_packet(packet->sender, packet->data, packet->size);
-            qemu_free(packet);
-        }
-        vlan->delivering = 0;
     }
 
-    return max_len;
+    if (sender->vlan->delivering) {
+        return qemu_enqueue_packet_iov(sender, iov, iovcnt);
+    }
+
+    ret = qemu_deliver_packet_iov(sender, iov, iovcnt);
+
+    qemu_flush_queued_packets(sender);
+
+    return ret;
 }
 
 static void config_error(Monitor *mon, const char *fmt, ...)