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, 241 insertions, 0 deletions

diff --git a/extras/libmemif/examples/icmp_responder/main.c b/extras/libmemif/examples/icmp_responder/main.c
new file mode 100644
index 00000000000..32b8ed7579a
--- /dev/null
+++ b/extras/libmemif/examples/icmp_responder/main.c
@@ -0,0 +1,241 @@
+/*
+ *------------------------------------------------------------------
+ * 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 "icmp_responder_example"
+
+#define IF_NAME	    "libmemif0"
+#define IF_ID	    0
+#define SOCKET_PATH "/run/vpp/memif.sock"
+const uint8_t HW_ADDR[6] = { 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa };
+const uint8_t IP_ADDR[4] = { 192, 168, 1, 1 };
+
+memif_connection_t intf;
+int epfd;
+
+/* 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;
+    }
+
+  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;
+}
+
+void
+print_help ()
+{
+  printf ("LIBMEMIF EXAMPLE APP: %s", APP_NAME);
+#ifdef ICMP_DBG
+  printf (" (debug)");
+#endif
+  printf ("\n");
+  printf ("==============================\n");
+  print_version ();
+  printf ("==============================\n");
+  printf (
+    "In this example, memif endpoint connects to an external application.\n");
+  printf (
+    "The example application can resolve ARP and reply to ICMPv4 packets.\n");
+  printf ("The program will exit once the interface is disconnected.\n");
+  printf ("==============================\n");
+  printf ("Usage: icmp_responder [OPTIONS]\n\n");
+  printf ("Options:\n");
+  printf ("\t-r\tInterface role <slave|master>. Default: slave\n");
+  printf ("\t-s\tSocket path. Supports abstract socket using @ before the "
+	  "path. Default: /run/vpp/memif.sock\n");
+  printf ("\t-i\tInterface id. Default: 0\n");
+  printf ("\t-a\tIPv4 address. Default: 192.168.1.1\n");
+  printf ("\t-h\tMac address. Default: aa:aa:aa:aa:aa:aa\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;
+  memif_conn_args_t memif_conn_args = { 0 };
+  int opt, err, ret = 0;
+  uint8_t is_master = 0;
+  char socket_path[108];
+  int id = IF_ID;
+
+  strncpy (socket_path, SOCKET_PATH, strlen (SOCKET_PATH));
+
+  /* prepare the private data */
+  memset (&intf, 0, sizeof (intf));
+  intf.packet_handler = icmp_packet_handler;
+  memcpy (intf.ip_addr, IP_ADDR, 4);
+  memcpy (intf.hw_addr, HW_ADDR, 6);
+
+  while ((opt = getopt (argc, argv, "r:s:i:a:h:?v")) != -1)
+    {
+      switch (opt)
+	{
+	case 'r':
+	  if (strncmp (optarg, "master", sizeof (optarg)) == 0)
+	    {
+	      is_master = 1;
+	    }
+	  else if (strncmp (optarg, "slave", sizeof (optarg)) == 0)
+	    {
+	      is_master = 0;
+	    }
+	  else
+	    {
+	      INFO ("Invalid role value: '%s'", optarg);
+	      return -1;
+	    }
+	  break;
+	case 's':
+	  sprintf (socket_path, "%s", optarg);
+	  break;
+	case 'i':
+	  id = atoi (optarg);
+	  break;
+	case 'a':
+	  if (parse_ip4 (optarg, intf.ip_addr) != 0)
+	    {
+	      INFO ("Invalid ipv4 address: %s", optarg);
+	      return -1;
+	    }
+	  break;
+	case 'h':
+	  if (parse_mac (optarg, intf.hw_addr) != 0)
+	    {
+	      INFO ("Invalid mac address: %s", optarg);
+	      return -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.
+   */
+  sprintf (memif_socket_args.path, "%s", socket_path);
+  /* Set application name */
+  strncpy (memif_socket_args.app_name, APP_NAME, strlen (APP_NAME));
+
+  /* configure autoconnect timer */
+  if (is_master == 0)
+    {
+      memif_socket_args.connection_request_timer.it_value.tv_sec = 2;
+      memif_socket_args.connection_request_timer.it_value.tv_nsec = 0;
+      memif_socket_args.connection_request_timer.it_interval.tv_sec = 2;
+      memif_socket_args.connection_request_timer.it_interval.tv_nsec = 0;
+    }
+
+  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.
+   */
+
+  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 (&intf.conn, &memif_conn_args, on_connect, on_disconnect,
+		  is_master ? responder : responder_zero_copy, (void *) &intf);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_create_socket: %s", memif_strerror (err));
+      return err;
+    }
+
+  do
+    {
+      err = memif_poll_event (memif_socket, -1);
+    }
+  while (err == MEMIF_ERR_SUCCESS);
+
+  return 0;
+
+error:
+  ret = -1;
+done:
+  free_memif_buffers (&intf);
+  memif_delete (&intf.conn);
+  memif_delete_socket (&memif_socket);
+  return ret;
+}