libmemif: refactor examples

- icmp_responder: responds to ICMPv4 and ARP requests
- loopback: connects two interfaces and sends a
  verification packet from master memif to slave memif
  where it is looped back
- loopback (reverse path): reverses direction of packet
  in loopback application (slave memif to master memif)

Type: refactor

Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
Change-Id: Ie90aaa3367269408efb6c5d538ad5aa827432238
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

1 files changed, 172 insertions, 0 deletions

diff --git a/extras/libmemif/examples/common/responder.c b/extras/libmemif/examples/common/responder.c
new file mode 100644
index 00000000000..e0fa9e35b08
--- /dev/null
+++ b/extras/libmemif/examples/common/responder.c
@@ -0,0 +1,172 @@
+#include <common.h>
+
+int
+responder (memif_conn_handle_t conn, void *private_ctx, uint16_t qid)
+{
+  memif_connection_t *c = (memif_connection_t *) private_ctx;
+  int err, i;
+  uint16_t tx;
+
+  /* receive packets from the shared memory */
+  err = memif_rx_burst (conn, qid, c->rx_bufs, MAX_MEMIF_BUFS, &c->rx_buf_num);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_rx_burst: %s", memif_strerror (err));
+      return err;
+    }
+
+  do
+    {
+      /* allocate tx buffers */
+      err = memif_buffer_alloc (conn, qid, c->tx_bufs, c->rx_buf_num,
+				&c->tx_buf_num, 2048);
+      /* suppress full ring error MEMIF_ERR_NOBUF_RING */
+      if (err != MEMIF_ERR_SUCCESS && err != MEMIF_ERR_NOBUF_RING)
+	{
+	  INFO ("memif_buffer_alloc: %s", memif_strerror (err));
+	  goto error;
+	}
+
+      /* Process the packets */
+      if (c->packet_handler == NULL)
+	{
+	  INFO ("Missing packet handler");
+	  goto error;
+	}
+      err = c->packet_handler (c);
+      if (err != 0)
+	{
+	  INFO ("packet handler error: %d", err);
+	  goto error;
+	}
+      /* Done processing packets */
+
+      /* refill the queue */
+      err = memif_refill_queue (conn, qid, c->tx_buf_num, 0);
+      if (err != MEMIF_ERR_SUCCESS)
+	{
+	  INFO ("memif_refill_queue: %s", memif_strerror (err));
+	  goto error;
+	}
+      c->rx_buf_num -= c->tx_buf_num;
+
+      err = memif_tx_burst (conn, qid, c->tx_bufs, c->tx_buf_num, &tx);
+      if (err != MEMIF_ERR_SUCCESS)
+	{
+	  INFO ("memif_tx_burst: %s", memif_strerror (err));
+	  goto error;
+	}
+      c->tx_buf_num -= tx;
+
+      /* This should never happen */
+      if (c->tx_buf_num != 0)
+	{
+	  INFO ("memif_tx_burst failed to send all allocated buffers.");
+	  goto error;
+	}
+    }
+  while (c->rx_buf_num > 0);
+
+  return 0;
+
+error:
+  err = memif_refill_queue (conn, qid, c->rx_buf_num, 0);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_refill_queue: %s", memif_strerror (err));
+      return err;
+    }
+  c->rx_buf_num = 0;
+
+  return -1;
+}
+
+int
+responder_zero_copy (memif_conn_handle_t conn, void *private_ctx, uint16_t qid)
+{
+  memif_connection_t *c = (memif_connection_t *) private_ctx;
+  int err, i;
+  uint16_t tx, tx2;
+
+  /* receive packets from the shared memory */
+  err = memif_rx_burst (conn, qid, c->rx_bufs, MAX_MEMIF_BUFS, &c->rx_buf_num);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_rx_burst: %s", memif_strerror (err));
+      return err;
+    }
+
+  do
+    {
+      /* Note that in zero copy memif_buffer_alloc is not part of respond
+      process,
+       * instead rx buffers are used directly using memif_buffer_enq_tx.
+       * /
+
+      /* Process the packets */
+      if (c->packet_handler == NULL)
+	{
+	  INFO ("Missing packet handler");
+	  goto error;
+	}
+      err = c->packet_handler (c);
+      if (err != 0)
+	{
+	  INFO ("packet handler error: %d", err);
+	  goto error;
+	}
+      /* Done processing packets */
+
+      /* Swap rx and tx buffers, swapped tx buffers are considered allocated
+       * and are ready to be transmitted. Notice that the buffers are swapped
+       * only in memif driver and locally remain in rx_bufs queue.
+       */
+      err = memif_buffer_enq_tx (conn, qid, c->rx_bufs, c->rx_buf_num, &tx);
+      /* suppress full ring error MEMIF_ERR_NOBUF_RING */
+      if (err != MEMIF_ERR_SUCCESS && err != MEMIF_ERR_NOBUF_RING)
+	{
+	  INFO ("memif_buffer_alloc: %s", memif_strerror (err));
+	  goto error;
+	}
+
+      /* refill the queue */
+      err = memif_refill_queue (conn, qid, tx, 0);
+      if (err != MEMIF_ERR_SUCCESS)
+	{
+	  INFO ("memif_refill_queue: %s", memif_strerror (err));
+	  goto error;
+	}
+      c->rx_buf_num -= tx;
+
+      /* Notice that we send from rx_bufs as the buffers were only swapped
+       * internally in memif driver */
+      err = memif_tx_burst (conn, qid, c->rx_bufs, tx, &tx2);
+      if (err != MEMIF_ERR_SUCCESS)
+	{
+	  INFO ("memif_tx_burst: %s", memif_strerror (err));
+	  goto error;
+	}
+      tx -= tx2;
+
+      /* This should never happen */
+      if (tx != 0)
+	{
+	  INFO ("memif_tx_burst failed to send all allocated buffers.");
+	  goto error;
+	}
+    }
+  while (c->rx_buf_num > 0);
+
+  return 0;
+
+error:
+  err = memif_refill_queue (conn, qid, c->rx_buf_num, 0);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_refill_queue: %s", memif_strerror (err));
+      return err;
+    }
+  c->rx_buf_num = 0;
+
+  return -1;
+}
\ No newline at end of file