forward: copy iob when broadcast forward

since iob offload, ipvx_dev_forward will remove d_iob, if there are multiple
devices, d_iob will be NULL when dev_forward is entered second time. and the
device that receives the packet cannot process the packet after forwarding it
so the iob copy is added.

Signed-off-by: zhanghongyu <[email protected]>

Author: zhhyu7

net/ipforward/ipv4_forward.c

@@ -341,6 +341,7 @@ int ipv4_forward_callback(FAR struct net_driver_s *fwddev, FAR void *arg)
 {
   FAR struct net_driver_s *dev = (FAR struct net_driver_s *)arg;
   FAR struct ipv4_hdr_s *ipv4;
+  FAR struct iob_s *iob;
   int ret;
 
   DEBUGASSERT(fwddev != NULL);
@@ -360,6 +361,24 @@ int ipv4_forward_callback(FAR struct net_driver_s *fwddev, FAR void *arg)
 
   if (fwddev != dev)
     {
+      /* Backup the forward IP packet */
+
+      iob = iob_tryalloc(true);
+      if (iob == NULL)
+        {
+          nerr("ERROR: iob alloc failed when forward broadcast\n");
+          return -ENOMEM;
+        }
+
+      iob_reserve(iob, CONFIG_NET_LL_GUARDSIZE);
+      ret = iob_clone_partial(dev->d_iob, dev->d_iob->io_pktlen, 0,
+                              iob, 0, true, false);
+      if (ret < 0)
+        {
+          iob_free_chain(iob);
+          return ret;
+        }
+
       /* Recover the pointer to the IPv4 header in the receiving device's
        * d_buf.
        */
@@ -371,9 +390,14 @@ int ipv4_forward_callback(FAR struct net_driver_s *fwddev, FAR void *arg)
       ret = ipv4_dev_forward(dev, fwddev, ipv4);
       if (ret < 0)
         {
+          iob_free_chain(iob);
           nwarn("WARNING: ipv4_dev_forward failed: %d\n", ret);
           return ret;
         }
+
+      /* Restore device iob with backup iob */
+
+      netdev_iob_replace(dev, iob);
     }
 
   return OK;

net/ipforward/ipv6_forward.c

@@ -468,6 +468,7 @@ int ipv6_forward_callback(FAR struct net_driver_s *fwddev, FAR void *arg)
 {
   FAR struct net_driver_s *dev = (FAR struct net_driver_s *)arg;
   FAR struct ipv6_hdr_s *ipv6;
+  FAR struct iob_s *iob;
   int ret;
 
   DEBUGASSERT(fwddev != NULL);
@@ -487,6 +488,24 @@ int ipv6_forward_callback(FAR struct net_driver_s *fwddev, FAR void *arg)
 
   if (fwddev != dev)
     {
+      /* Backup the forward IP packet */
+
+      iob = iob_tryalloc(true);
+      if (iob == NULL)
+        {
+          nerr("ERROR: iob alloc failed when forward broadcast\n");
+          return -ENOMEM;
+        }
+
+      iob_reserve(iob, CONFIG_NET_LL_GUARDSIZE);
+      ret = iob_clone_partial(dev->d_iob, dev->d_iob->io_pktlen, 0,
+                              iob, 0, true, false);
+      if (ret < 0)
+        {
+          iob_free_chain(iob);
+          return ret;
+        }
+
       /* Recover the pointer to the IPv6 header in the receiving device's
        * d_buf.
        */
@@ -498,9 +517,14 @@ int ipv6_forward_callback(FAR struct net_driver_s *fwddev, FAR void *arg)
       ret = ipv6_dev_forward(dev, fwddev, ipv6);
       if (ret < 0)
         {
+          iob_free_chain(iob);
           nwarn("WARNING: ipv6_dev_forward failed: %d\n", ret);
           return ret;
         }
+
+      /* Restore device iob with backup iob */
+
+      netdev_iob_replace(dev, iob);
     }
 
   return OK;