Shared memory packet interface (memif) library

Change-Id: I5097462ae85acd705f19e92517c01094dba7565f
Signed-off-by: Jakub Grajciar <grajciar.jakub@gmail.com>
diff --git a/extras/libmemif/examples/icmp_responder/main.c b/extras/libmemif/examples/icmp_responder/main.c
new file mode 100644
index 0000000..5351b6b
--- /dev/null
+++ b/extras/libmemif/examples/icmp_responder/main.c
@@ -0,0 +1,416 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2017 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 <stdint.h>
+#include <net/if.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/uio.h>
+#include <sys/mman.h>
+#include <sys/prctl.h>
+#include <inttypes.h>
+#include <string.h>
+#include <stdio.h>
+#include <netdb.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <arpa/inet.h>
+#include <stdlib.h>
+#include <netinet/if_ether.h>
+#include <net/if_arp.h>
+#include <asm/byteorder.h>
+#include <byteswap.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+
+#include <libmemif.h>
+#include <icmp_proto.h>
+
+#define APP_NAME "ICMP_Responder"
+#define IF_NAME  "memif_connection"
+
+
+#ifdef ICMP_DBG
+#define DBG(...) do {                                               \
+                    printf (APP_NAME":%s:%d: ", __func__, __LINE__);         \
+                    printf (__VA_ARGS__);                           \
+                    printf ("\n");                                  \
+                } while (0)
+#else
+#define DBG(...)
+#endif
+
+#define INFO(...) do {                                              \
+                    printf ("INFO: "__VA_ARGS__);                   \
+                    printf ("\n");                                  \
+                } while (0)
+
+/* maximum tx/rx memif buffers */
+#define MAX_MEMIF_BUFS 256
+
+typedef struct
+{
+  uint16_t index;
+  /* memif conenction handle */
+  memif_conn_handle_t conn;
+  /* transmit queue id */
+  uint16_t tx_qid;
+  /* tx buffers */
+  memif_buffer_t *tx_bufs;
+  /* allocated tx buffers counter */
+  /* number of tx buffers pointing to shared memory */
+  uint16_t tx_buf_num;
+  /* rx buffers */
+  memif_buffer_t *rx_bufs;
+  /* allcoated rx buffers counter */
+  /* number of rx buffers pointing to shared memory */
+  uint16_t rx_buf_num;
+  /* interface ip address */
+  uint8_t ip_addr[4];
+} memif_connection_t;
+
+memif_connection_t memif_connection;
+int epfd;
+
+static void
+print_memif_details ()
+{
+  memif_connection_t *c = &memif_connection;
+  printf ("MEMIF DETAILS\n");
+  printf ("==============================\n");
+
+
+  memif_details_t md;
+  memset (&md, 0, sizeof (md));
+  ssize_t buflen = 2048;
+  char *buf = malloc (buflen);
+  memset (buf, 0, buflen);
+  int err, e;
+
+  err = memif_get_details (c->conn, &md, buf, buflen);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("%s", memif_strerror (err));
+      if (err == MEMIF_ERR_NOCONN)
+	{
+	  free (buf);
+	  return;
+	}
+    }
+
+  printf ("\tinterface name: %s\n", (char *) md.if_name);
+  printf ("\tapp name: %s\n", (char *) md.inst_name);
+  printf ("\tremote interface name: %s\n", (char *) md.remote_if_name);
+  printf ("\tremote app name: %s\n", (char *) md.remote_inst_name);
+  printf ("\tid: %u\n", md.id);
+  printf ("\tsecret: %s\n", (char *) md.secret);
+  printf ("\trole: ");
+  if (md.role)
+    printf ("slave\n");
+  else
+    printf ("master\n");
+  printf ("\tmode: ");
+  switch (md.mode)
+    {
+    case 0:
+      printf ("ethernet\n");
+      break;
+    case 1:
+      printf ("ip\n");
+      break;
+    case 2:
+      printf ("punt/inject\n");
+      break;
+    default:
+      printf ("unknown\n");
+      break;
+    }
+  printf ("\tsocket filename: %s\n", (char *) md.socket_filename);
+  printf ("\tsocket filename: %s\n", (char *) md.socket_filename);
+  printf ("\trx queues:\n");
+  for (e = 0; e < md.rx_queues_num; e++)
+    {
+      printf ("\t\tqueue id: %u\n", md.rx_queues[e].qid);
+      printf ("\t\tring size: %u\n", md.rx_queues[e].ring_size);
+      printf ("\t\tbuffer size: %u\n", md.rx_queues[e].buffer_size);
+    }
+  printf ("\ttx queues:\n");
+  for (e = 0; e < md.tx_queues_num; e++)
+    {
+      printf ("\t\tqueue id: %u\n", md.tx_queues[e].qid);
+      printf ("\t\tring size: %u\n", md.tx_queues[e].ring_size);
+      printf ("\t\tbuffer size: %u\n", md.tx_queues[e].buffer_size);
+    }
+  printf ("\tlink: ");
+  if (md.link_up_down)
+    printf ("up\n");
+  else
+    printf ("down\n");
+
+  free (buf);
+}
+
+/* informs user about connected status. private_ctx is used by user to identify connection
+    (multiple connections WIP) */
+int
+on_connect (memif_conn_handle_t conn, void *private_ctx)
+{
+  INFO ("memif connected!");
+  return 0;
+}
+
+/* informs user about disconnected status. private_ctx is used by user to identify connection
+    (multiple connections WIP) */
+int
+on_disconnect (memif_conn_handle_t conn, void *private_ctx)
+{
+  INFO ("memif disconnected!");
+  return 0;
+}
+
+int
+icmpr_memif_delete ()
+{
+  int err;
+  /* disconenct then delete memif connection */
+  err = memif_delete (&(&memif_connection)->conn);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_delete: %s", memif_strerror (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: %d\n", MEMIF_VERSION);
+  printf ("\tuse CTRL+C to exit\n");
+}
+
+int
+icmpr_buffer_alloc (long n, uint16_t qid)
+{
+  memif_connection_t *c = &memif_connection;
+  int err;
+  uint16_t r;
+  /* set data pointer to shared memory and set buffer_len to shared mmeory buffer len */
+  err = memif_buffer_alloc (c->conn, qid, c->tx_bufs, n, &r);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_buffer_alloc: %s", memif_strerror (err));
+      c->tx_buf_num += r;
+      return -1;
+    }
+  c->tx_buf_num += r;
+  DBG ("allocated %d/%ld buffers, %u free buffers", r, n,
+       MAX_MEMIF_BUFS - c->tx_buf_num);
+  return 0;
+}
+
+int
+icmpr_tx_burst (uint16_t qid)
+{
+  memif_connection_t *c = &memif_connection;
+  int err;
+  uint16_t r;
+  /* inform peer memif interface about data in shared memory buffers */
+  /* mark memif buffers as free */
+  err = memif_tx_burst (c->conn, qid, c->tx_bufs, c->tx_buf_num, &r);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_tx_burst: %s", memif_strerror (err));
+  DBG ("tx: %d/%u", r, c->tx_buf_num);
+  c->tx_buf_num -= r;
+  return 0;
+}
+
+int
+icmpr_free ()
+{
+  /* application cleanup */
+  int err;
+  memif_connection_t *c = &memif_connection;
+  free (c->tx_bufs);
+  c->tx_bufs = NULL;
+  free (c->rx_bufs);
+  c->rx_bufs = NULL;
+
+  err = memif_cleanup ();
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_delete: %s", memif_strerror (err));
+
+  return 0;
+}
+
+void
+icmpr_exit (int sig)
+{
+  printf ("\n");
+  icmpr_memif_delete ();
+  icmpr_free ();
+  exit (EXIT_SUCCESS);
+}
+
+/* called when event is polled on interrupt file descriptor.
+    there are packets in shared memory ready to be received */
+int
+on_interrupt (memif_conn_handle_t conn, void *private_ctx, uint16_t qid)
+{
+  DBG ("interrupted");
+  memif_connection_t *c = &memif_connection;
+  int err;
+  uint16_t rx;
+  /* receive data from shared memory buffers */
+  err = memif_rx_burst (c->conn, qid, c->rx_bufs, MAX_MEMIF_BUFS, &rx);
+  c->rx_buf_num += rx;
+
+  DBG ("received %d buffers. %u/%u alloc/free buffers",
+       rx, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+
+  if (icmpr_buffer_alloc (rx, c->tx_qid) < 0)
+    {
+      INFO ("buffer_alloc error");
+      goto error;
+    }
+  int i;
+  for (i = 0; i < rx; i++)
+    {
+      resolve_packet ((void *) (c->rx_bufs + i)->data,
+		      (c->rx_bufs + i)->data_len,
+		      (void *) (c->tx_bufs + i)->data,
+		      &(c->tx_bufs + i)->data_len, c->ip_addr);
+    }
+
+  uint16_t fb;
+  /* mark memif buffers and shared memory buffers as free */
+  err = memif_buffer_free (c->conn, qid, c->rx_bufs, rx, &fb);
+  c->rx_buf_num -= fb;
+
+  DBG ("freed %d buffers. %u/%u alloc/free buffers",
+       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+
+  icmpr_tx_burst (c->tx_qid);
+
+  return 0;
+
+error:
+  err = memif_buffer_free (c->conn, qid, c->rx_bufs, rx, &fb);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_buffer_free: %s", memif_strerror (err));
+  c->rx_buf_num -= fb;
+  DBG ("freed %d buffers. %u/%u alloc/free buffers",
+       fb, c->rx_buf_num, MAX_MEMIF_BUFS - c->rx_buf_num);
+  return 0;
+}
+
+int
+icmpr_memif_create (int is_master)
+{
+  /* setting memif connection arguments */
+  memif_conn_args_t args;
+  int fd = -1;
+  memset (&args, 0, sizeof (args));
+  args.is_master = is_master;
+  args.log2_ring_size = 10;
+  args.buffer_size = 2048;
+  args.num_s2m_rings = 2;
+  args.num_m2s_rings = 2;
+  strncpy ((char *) args.interface_name, IF_NAME, strlen (IF_NAME));
+  strncpy ((char *) args.instance_name, APP_NAME, strlen (APP_NAME));
+  args.mode = 0;
+  /* socket filename is not specified, because this app is supposed to
+     connect to VPP over memif. so default socket filename will be used */
+  /* default socketfile = /run/vpp/memif.sock */
+
+  args.interface_id = 0;
+  /* last argument for memif_create (void * private_ctx) is used by user
+     to identify connection. this context is returned with callbacks */
+  int err = memif_create (&(&memif_connection)->conn,
+			  &args, on_connect, on_disconnect, on_interrupt,
+			  NULL);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_create: %s", memif_strerror (err));
+  return 0;
+}
+
+int
+main (int argc, char *argv[])
+{
+  memif_connection_t *c = &memif_connection;
+
+  signal (SIGINT, icmpr_exit);
+
+  /* initialize global memif connection handle */
+  c->conn = NULL;
+  if (argc == 1)
+    c->tx_qid = 0;
+  else
+    {
+      char *end;
+      c->tx_qid = strtol (argv[1], &end, 10);
+    }
+  INFO ("tx qid: %u", c->tx_qid);
+  /* alloc memif buffers */
+  c->rx_buf_num = 0;
+  c->rx_bufs =
+    (memif_buffer_t *) malloc (sizeof (memif_buffer_t) * MAX_MEMIF_BUFS);
+  c->tx_buf_num = 0;
+  c->tx_bufs =
+    (memif_buffer_t *) malloc (sizeof (memif_buffer_t) * MAX_MEMIF_BUFS);
+  c->ip_addr[0] = 192;
+  c->ip_addr[1] = 168;
+  c->ip_addr[2] = 1;
+  c->ip_addr[3] = 2;
+  /* initialize memory interface */
+  int err;
+  /* if valid callback is passed as argument, fd event polling will be done by user
+     all file descriptors and events will be passed to user in this callback */
+  /* if callback is set to NULL libmemif will handle fd event polling */
+  err = memif_init (NULL, APP_NAME);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_init: %s", memif_strerror (err));
+
+  print_help ();
+
+  icmpr_memif_create (0);
+  print_memif_details ();
+
+  /* main loop */
+  while (1)
+    {
+      if (memif_poll_event (-1) < 0)
+	{
+	  DBG ("poll_event error!");
+	}
+    }
+}