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, 307 insertions, 0 deletions

diff --git a/extras/libmemif/examples/loopback/main.c b/extras/libmemif/examples/loopback/main.c
new file mode 100644
index 00000000000..e68f69ddaf0
--- /dev/null
+++ b/extras/libmemif/examples/loopback/main.c
@@ -0,0 +1,307 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <inttypes.h>
+#include <string.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <getopt.h>
+
+#include <libmemif.h>
+#include <common.h>
+
+#define APP_NAME "loopback_example"
+#define IF0_NAME "lo0"
+#define IF1_NAME "lo1"
+
+memif_connection_t intf0, intf1;
+int is_reverse;
+int epfd;
+
+int
+packet_generator (memif_connection_t *c, uint16_t num_pkts)
+{
+  int i, bi = 0;
+  memif_buffer_t *mb;
+
+  for (i = 0; (i < num_pkts) && (bi < c->tx_buf_num); i++)
+    {
+      mb = &c->tx_bufs[bi++];
+      memset (mb->data, 1, mb->len);
+    }
+
+  return 0;
+}
+
+/* informs user about connected status. private_ctx is used by user to identify
+ * connection */
+int
+on_connect (memif_conn_handle_t conn, void *private_ctx)
+{
+  INFO ("memif connected!");
+  int err;
+
+  memif_connection_t *c = (memif_connection_t *) private_ctx;
+
+  c->is_connected = 1;
+  alloc_memif_buffers (c);
+
+  err = memif_refill_queue (conn, 0, -1, 0);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_refill_queue: %s", memif_strerror (err));
+      return err;
+    }
+
+  print_memif_details (c);
+
+  /* Once both interfaces are connected send a test packet, master -> slave.
+   * Slave will use zero-copy method to reply the same pakcet back.
+   * (Configured by assigning responder_zero_copy as on_interrupt callback.)
+   */
+  if ((intf0.is_connected == 1) && (intf1.is_connected == 1))
+    {
+      send_packets (is_reverse ? &intf1 : &intf0, 0, packet_generator, 1,
+		    2048);
+    }
+
+  return 0;
+}
+
+/* informs user about disconnected status. private_ctx is used by user to
+ * identify connection */
+int
+on_disconnect (memif_conn_handle_t conn, void *private_ctx)
+{
+  INFO ("memif disconnected!");
+
+  memif_connection_t *c = (memif_connection_t *) private_ctx;
+
+  c->is_connected = 0;
+  free_memif_buffers (c);
+
+  /* stop event polling thread */
+  int err = memif_cancel_poll_event (memif_get_socket_handle (conn));
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("We are doomed...");
+
+  return 0;
+}
+
+int
+verify_packet (memif_conn_handle_t conn, void *private_ctx, uint16_t qid)
+{
+  memif_connection_t *c = (memif_connection_t *) private_ctx;
+  int err;
+  void *want;
+
+  err = memif_rx_burst (conn, qid, c->rx_bufs, MAX_MEMIF_BUFS, &c->rx_buf_num);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("meif_rx_burst: %s", memif_strerror (err));
+      return err;
+    }
+
+  want = malloc (c->rx_bufs[0].len);
+  if (want == NULL)
+    {
+      INFO ("Out of memory");
+      goto done;
+    }
+
+  memset (want, 1, c->rx_bufs[0].len);
+
+  err = memcmp (c->rx_bufs[0].data, want, c->rx_bufs[0].len);
+  if (err != 0)
+    {
+      INFO ("Received malformed data. ret: %d", err);
+    }
+  else
+    {
+      INFO ("Received correct data.");
+    }
+
+done:
+  err = memif_refill_queue (conn, qid, c->rx_buf_num, 0);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_refill_queue: %s", memif_strerror (err));
+
+  /* stop polling and exit the program */
+  INFO ("Stopping the program");
+  err = memif_cancel_poll_event (memif_get_socket_handle (conn));
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("We are doomed...");
+
+  return err;
+}
+
+int
+create_memif_interface (memif_socket_handle_t memif_socket,
+			const char *if_name, int id, uint8_t is_master,
+			memif_connection_t *ctx)
+{
+  memif_conn_args_t memif_conn_args = { 0 };
+  int err;
+
+  memif_conn_args.socket = memif_socket;
+  memif_conn_args.interface_id = id;
+  strncpy (memif_conn_args.interface_name, if_name,
+	   sizeof (memif_conn_args.interface_name));
+  memif_conn_args.is_master = is_master;
+
+  err = memif_create (&ctx->conn, &memif_conn_args, on_connect, on_disconnect,
+		      is_master ? verify_packet : responder_zero_copy,
+		      (void *) ctx);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_create_socket: %s", memif_strerror (err));
+      return err;
+    }
+
+  return 0;
+}
+
+void
+print_help ()
+{
+  printf ("LIBMEMIF EXAMPLE APP: %s", APP_NAME);
+#ifdef ICMP_DBG
+  printf (" (debug)");
+#endif
+  printf ("\n");
+  printf ("==============================\n");
+  printf ("libmemif version: %s", LIBMEMIF_VERSION);
+#ifdef MEMIF_DBG
+  printf (" (debug)");
+#endif
+  printf ("\n");
+
+  printf ("memif version: %s\n", memif_get_version_str ());
+  printf ("==============================\n");
+  printf ("In this example, two memif endpoints are connected to create a "
+	  "loopback.\n");
+  printf ("Once connected, a test packet is sent out the memif master "
+	  "interface to\n");
+  printf (
+    "the memif slave interface, which replies with the same packet in a\n");
+  printf ("zero-copy way.\n");
+  printf (
+    "In reverse mode, the packet is sent from the slave interface and is\n");
+  printf ("looped back by the master interface.\n");
+  printf ("==============================\n");
+  printf ("Usage: loopback [OPTIONS]\n\n");
+  printf ("Options:\n");
+  printf ("\t-r\tReverse mode, verification packet is sent by slave.\n");
+  printf ("\t-?\tShow help and exit.\n");
+  printf ("\t-v\tShow libmemif and memif version information and exit.\n");
+}
+
+int
+main (int argc, char *argv[])
+{
+  memif_socket_args_t memif_socket_args = { 0 };
+  memif_socket_handle_t memif_socket;
+  int opt, err, ret = 0;
+  is_reverse = 0;
+
+  while ((opt = getopt (argc, argv, "r?v")) != -1)
+    {
+      switch (opt)
+	{
+	case 'r':
+	  is_reverse = 1;
+	  break;
+	case '?':
+	  print_help ();
+	  return 0;
+	case 'v':
+	  print_version ();
+	  return 0;
+	}
+    }
+
+  /** Create memif socket
+   *
+   * Interfaces are internally stored in a database referenced by memif socket.
+   */
+  /* Abstract socket supported */
+  memif_socket_args.path[0] = '@';
+  strncpy (memif_socket_args.path + 1, APP_NAME, strlen (APP_NAME));
+  /* Set application name */
+  strncpy (memif_socket_args.app_name, APP_NAME, strlen (APP_NAME));
+
+  err = memif_create_socket (&memif_socket, &memif_socket_args, NULL);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_create_socket: %s", memif_strerror (err));
+      goto error;
+    }
+
+  /** Create memif interfaces
+   *
+   * Both interaces are assigned the same socket and same id to create a
+   * loopback.
+   */
+
+  /* prepare the private data */
+  memset (&intf0, 0, sizeof (intf0));
+  memset (&intf1, 0, sizeof (intf1));
+  if (is_reverse)
+    {
+      intf0.packet_handler = basic_packet_handler;
+    }
+  else
+    {
+      intf1.packet_handler = basic_packet_handler;
+    }
+
+  err =
+    create_memif_interface (memif_socket, IF0_NAME, 0, /* master */ 1, &intf0);
+  if (err != 0)
+    {
+      goto error;
+    }
+
+  err =
+    create_memif_interface (memif_socket, IF1_NAME, 0, /* slave */ 0, &intf1);
+  if (err != 0)
+    {
+      goto error;
+    }
+
+  do
+    {
+      err = memif_poll_event (memif_socket, -1);
+    }
+  while (err == MEMIF_ERR_SUCCESS);
+
+  return 0;
+
+error:
+  ret = -1;
+done:
+  free_memif_buffers (&intf0);
+  free_memif_buffers (&intf1);
+  memif_delete (&intf0.conn);
+  memif_delete (&intf1.conn);
+  memif_delete_socket (&memif_socket);
+  return ret;
+}