net/netdev: add devif_loopback_out() to check the loopback case where a packet is being sent to itself. Modify the net driver to call this function in this case. This function will simply re-inject the packet back into the network and the network driver will not put anything on the wire.

2026-06-05 07:12:54 +08:00 · 2018-08-24 09:21:33 -06:00
parent f74ddd2a04
commit 0074afa0ac
33 changed files with 639 additions and 366 deletions
@@ -36,6 +36,7 @@
 # Network device interface source files

 NET_CSRCS += devif_initialize.c devif_send.c devif_poll.c devif_callback.c
+NET_CSRCS += devif_loopbackout.c

 # Device driver IP packet receipt interfaces

@@ -0,0 +1,161 @@
+/****************************************************************************
+ * net/devif/devif_loopbackout.c
+ *
+ *   Copyright (C) 2018 Pinecone Inc. All rights reserved.
+ *   Author: Xiang Xiao <xiaoxiang@pinecone.net>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+
+#include <nuttx/net/ip.h>
+#include <nuttx/net/pkt.h>
+#include <nuttx/net/netdev.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* This is a helper pointer for accessing the contents of the ip header */
+
+#define IPv4BUF ((FAR struct ipv4_hdr_s *)(dev->d_buf + dev->d_llhdrlen))
+#define IPv6BUF ((FAR struct ipv6_hdr_s *)(dev->d_buf + dev->d_llhdrlen))
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+static bool is_loopback(FAR struct net_driver_s *dev)
+{
+  if (dev->d_len > 0)
+    {
+#ifdef CONFIG_NET_IPv4
+      if ((IPv4BUF->vhl & IP_VERSION_MASK) == IPv4_VERSION &&
+           net_ipv4addr_hdrcmp(IPv4BUF->destipaddr, &dev->d_ipaddr))
+        {
+          return true;
+        }
+#endif
+
+#ifdef CONFIG_NET_IPv6
+      if ((IPv6BUF->vtc & IP_VERSION_MASK) == IPv6_VERSION &&
+          net_ipv6addr_hdrcmp(IPv6BUF->destipaddr, dev->d_ipv6addr))
+        {
+          return true;
+        }
+#endif
+    }
+
+  return false;
+}
+
+/****************************************************************************
+ * Name: devif_loopback_out
+ *
+ * Description:
+ *   This function should be called before sending out a packet. The function
+ *   checks the destination address of the packet to see whether the target of
+ *   packet is ourself and then consume the packet directly by calling input
+ *   process functions.
+ *
+ * Returned Value:
+ *   Zero is returned if the packet don't loop back to ourself, otherwise
+ *   a no zero value is returned.
+ *
+ ****************************************************************************/
+
+int devif_loopback_out(FAR struct net_driver_s *dev)
+{
+  if (!is_loopback(dev))
+    {
+      return 0;
+    }
+
+  /* Loop while if there is data "sent" to ourself.
+   * Sending, of course, just means relaying back through the network.
+   */
+
+  do
+    {
+       NETDEV_TXPACKETS(dev);
+       NETDEV_RXPACKETS(dev);
+
+#ifdef CONFIG_NET_PKT
+      /* When packet sockets are enabled, feed the frame into the packet tap */
+
+       pkt_input(dev);
+#endif
+
+      /* We only accept IP packets of the configured type */
+
+#ifdef CONFIG_NET_IPv4
+      if ((IPv4BUF->vhl & IP_VERSION_MASK) == IPv4_VERSION)
+        {
+          ninfo("IPv4 frame\n");
+
+          NETDEV_RXIPV4(dev);
+          ipv4_input(dev);
+        }
+      else
+#endif
+#ifdef CONFIG_NET_IPv6
+      if ((IPv6BUF->vtc & IP_VERSION_MASK) == IPv6_VERSION)
+        {
+          ninfo("Iv6 frame\n");
+
+          NETDEV_RXIPV6(dev);
+          ipv6_input(dev);
+        }
+      else
+#endif
+        {
+          NETDEV_RXDROPPED(dev);
+        }
+
+      NETDEV_TXDONE(dev);
+
+      /* Add the data link header length for the next loop */
+
+      if (dev->d_len != 0)
+        {
+          dev->d_len += dev->d_llhdrlen;
+        }
+    }
+  while (dev->d_len > 0);
+
+  return 1;
+}
+