libmemif: external region support

region 0: descriptors
region 1: buffers (external)

Change-Id: Ia728967817b4c78bc00f8eed44606d0c5bc386b0
Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
diff --git a/extras/libmemif/examples/icmp_responder-eb/main.c b/extras/libmemif/examples/icmp_responder-eb/main.c
new file mode 100644
index 0000000..9e71d28
--- /dev/null
+++ b/extras/libmemif/examples/icmp_responder-eb/main.c
@@ -0,0 +1,1073 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2018 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.
+ *------------------------------------------------------------------
+ */
+
+#define _GNU_SOURCE
+#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 <pthread.h>
+#include <time.h>
+
+#ifndef TIME_UTC
+#define TIME_UTC 1
+#endif /* TIME_UTC */
+
+#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 /* ICMP_DBG */
+
+#define INFO(...) do {					\
+			printf("INFO: "__VA_ARGS__);	\
+			printf("\n");			\
+		} while (0)
+
+#define MAX_MEMIF_BUFS	256
+#define MAX_CONNS	50
+
+
+#ifndef __NR_memfd_create
+#if defined __x86_64__
+#define __NR_memfd_create 319
+#elif defined __arm__
+#define __NR_memfd_create 385
+#elif defined __aarch64__
+#define __NR_memfd_create 279
+#else
+#error "__NR_memfd_create unknown for this architecture"
+#endif
+#endif
+
+#ifndef HAVE_MEMFD_CREATE
+static inline int
+memfd_create (const char *name, unsigned int flags)
+{
+  return syscall (__NR_memfd_create, name, flags);
+}
+#endif
+
+#ifndef F_LINUX_SPECIFIC_BASE
+#define F_LINUX_SPECIFIC_BASE 1024
+#endif
+
+#ifndef MFD_ALLOW_SEALING
+#define MFD_ALLOW_SEALING       0x0002U
+#endif
+
+#ifndef F_ADD_SEALS
+#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
+#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10)
+
+#define F_SEAL_SEAL     0x0001	/* prevent further seals from being set */
+#define F_SEAL_SHRINK   0x0002	/* prevent file from shrinking */
+#define F_SEAL_GROW     0x0004	/* prevent file from growing */
+#define F_SEAL_WRITE    0x0008	/* prevent writes */
+#endif
+
+typedef struct
+{
+  uint16_t index;
+
+  memif_conn_handle_t conn;
+
+  uint16_t tx_buf_num;
+  uint16_t rx_buf_num;
+  memif_buffer_t *tx_bufs;
+  memif_buffer_t *rx_bufs;
+
+  uint8_t ip_addr[4];
+  uint64_t tx_counter, rx_counter, tx_err_counter;
+  uint64_t t_sec, t_nsec;
+} memif_connection_t;
+
+typedef struct
+{
+  uint16_t index;
+  uint64_t packet_num;
+  uint8_t ip_daddr[4];
+  uint8_t hw_daddr[6];
+} icmpr_thread_data_t;
+
+icmpr_thread_data_t icmpr_thread_data[MAX_CONNS];
+pthread_t thread[MAX_CONNS];
+int epfd;
+long ctx[MAX_CONNS];
+memif_connection_t memif_connection[MAX_CONNS];
+
+static 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_get_version ());
+  printf ("commands:\n");
+  printf ("\thelp - prints this help\n");
+  printf ("\texit - exit app\n");
+  printf
+    ("\tconn <index> <mode> <interrupt> - create memif. index used as interface id. mode: 0 = slave | 1 = master. interrupt: none = default | 1 = handle ARP only\n");
+  printf ("\tdel <index> - delete memif\n");
+  printf ("\tshow - show connection details\n");
+  printf ("\tsend <index> <tx> <ip> <mac> - send icmp\n");
+}
+
+static void
+print_memif_details ()
+{
+  memif_details_t md;
+  ssize_t buflen;
+  char *buf;
+  int err, i, e;
+  buflen = 2048;
+  buf = malloc (buflen);
+  printf ("MEMIF DETAILS\n");
+  printf ("==============================\n");
+  for (i = 0; i < MAX_CONNS; i++)
+    {
+      memif_connection_t *c = &memif_connection[i];
+
+      memset (&md, 0, sizeof (md));
+      memset (buf, 0, buflen);
+
+      err = memif_get_details (c->conn, &md, buf, buflen);
+      if (err != MEMIF_ERR_SUCCESS)
+	{
+	  if (err != MEMIF_ERR_NOCONN)
+	    INFO ("%s", memif_strerror (err));
+	  continue;
+	}
+
+      printf ("interface index: %d\n", i);
+
+      printf ("\tinterface ip: %u.%u.%u.%u\n",
+	      c->ip_addr[0], c->ip_addr[1], c->ip_addr[2], c->ip_addr[3]);
+      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 ("\tregions:\n");
+      for (e = 0; e < md.regions_num; e++)
+	{
+	  printf ("\t\tindex: %u\n", md.regions[e].index);
+	  printf ("\t\taddress: %p\n", md.regions[e].addr);
+	  printf ("\t\tsize: %u\n", md.regions[e].size);
+	  printf ("\t\tfd: %d\n", md.regions[e].fd);
+	  if (md.regions[e].is_external)
+	    printf ("\t\texternal\n");
+	}
+      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\tring rx mode: %s\n",
+		  md.rx_queues[e].flags ? "polling" : "interrupt");
+	  printf ("\t\tring head: %u\n", md.rx_queues[e].head);
+	  printf ("\t\tring tail: %u\n", md.rx_queues[e].tail);
+	  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\tring rx mode: %s\n",
+		  md.tx_queues[e].flags ? "polling" : "interrupt");
+	  printf ("\t\tring head: %u\n", md.tx_queues[e].head);
+	  printf ("\t\tring tail: %u\n", md.tx_queues[e].tail);
+	  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);
+}
+
+void
+icmpr_print_counters ()
+{
+  int i;
+  for (i = 0; i < MAX_CONNS; i++)
+    {
+      memif_connection_t *c = &memif_connection[i];
+      if (c->conn == NULL)
+	continue;
+      printf ("===============================\n");
+      printf ("interface index: %d\n", c->index);
+      printf ("\trx: %lu\n", c->rx_counter);
+      printf ("\ttx: %lu\n", c->tx_counter);
+      printf ("\ttx_err: %lu\n", c->tx_err_counter);
+    }
+}
+
+void
+icmpr_reset_counters ()
+{
+  int i;
+  for (i = 0; i < MAX_CONNS; i++)
+    {
+      memif_connection_t *c = &memif_connection[i];
+      if (c->conn == NULL)
+	continue;
+      c->tx_err_counter = c->tx_counter = c->rx_counter = 0;
+    }
+}
+
+int
+add_epoll_fd (int fd, uint32_t events)
+{
+  if (fd < 0)
+    {
+      DBG ("invalid fd %d", fd);
+      return -1;
+    }
+  struct epoll_event evt;
+  memset (&evt, 0, sizeof (evt));
+  evt.events = events;
+  evt.data.fd = fd;
+  if (epoll_ctl (epfd, EPOLL_CTL_ADD, fd, &evt) < 0)
+    {
+      DBG ("epoll_ctl: %s fd %d", strerror (errno), fd);
+      return -1;
+    }
+  DBG ("fd %d added to epoll", fd);
+  return 0;
+}
+
+int
+mod_epoll_fd (int fd, uint32_t events)
+{
+  if (fd < 0)
+    {
+      DBG ("invalid fd %d", fd);
+      return -1;
+    }
+  struct epoll_event evt;
+  memset (&evt, 0, sizeof (evt));
+  evt.events = events;
+  evt.data.fd = fd;
+  if (epoll_ctl (epfd, EPOLL_CTL_MOD, fd, &evt) < 0)
+    {
+      DBG ("epoll_ctl: %s fd %d", strerror (errno), fd);
+      return -1;
+    }
+  DBG ("fd %d moddified on epoll", fd);
+  return 0;
+}
+
+int
+del_epoll_fd (int fd)
+{
+  if (fd < 0)
+    {
+      DBG ("invalid fd %d", fd);
+      return -1;
+    }
+  struct epoll_event evt;
+  memset (&evt, 0, sizeof (evt));
+  if (epoll_ctl (epfd, EPOLL_CTL_DEL, fd, &evt) < 0)
+    {
+      DBG ("epoll_ctl: %s fd %d", strerror (errno), fd);
+      return -1;
+    }
+  DBG ("fd %d removed from epoll", fd);
+  return 0;
+}
+
+int
+on_connect (memif_conn_handle_t conn, void *private_ctx)
+{
+  INFO ("memif connected!");
+  memif_refill_queue (conn, 0, -1, 0);
+  return 0;
+}
+
+int
+on_disconnect (memif_conn_handle_t conn, void *private_ctx)
+{
+  INFO ("memif disconnected!");
+  return 0;
+}
+
+int
+control_fd_update (int fd, uint8_t events)
+{
+  /* convert memif event definitions to epoll events */
+  if (events & MEMIF_FD_EVENT_DEL)
+    return del_epoll_fd (fd);
+
+  uint32_t evt = 0;
+  if (events & MEMIF_FD_EVENT_READ)
+    evt |= EPOLLIN;
+  if (events & MEMIF_FD_EVENT_WRITE)
+    evt |= EPOLLOUT;
+
+  if (events & MEMIF_FD_EVENT_MOD)
+    return mod_epoll_fd (fd, evt);
+
+  return add_epoll_fd (fd, evt);
+}
+
+int
+icmpr_memif_delete (long index)
+{
+  if (index >= MAX_CONNS)
+    {
+      INFO ("connection array overflow");
+      return 0;
+    }
+  if (index < 0)
+    {
+      INFO ("don't even try...");
+      return 0;
+    }
+  memif_connection_t *c = &memif_connection[index];
+
+  if (c->rx_bufs)
+    free (c->rx_bufs);
+  c->rx_bufs = NULL;
+  c->rx_buf_num = 0;
+  if (c->tx_bufs)
+    free (c->tx_bufs);
+  c->tx_bufs = NULL;
+  c->tx_buf_num = 0;
+
+  int err;
+  /* disconenct then delete memif connection */
+  err = memif_delete (&c->conn);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_delete: %s", memif_strerror (err));
+  if (c->conn != NULL)
+    INFO ("memif delete fail");
+  return 0;
+}
+
+int
+icmpr_free ()
+{
+  /* application cleanup */
+  int err;
+  long i;
+  for (i = 0; i < MAX_CONNS; i++)
+    {
+      memif_connection_t *c = &memif_connection[i];
+      if (c->conn)
+	icmpr_memif_delete (i);
+    }
+
+  err = memif_cleanup ();
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_delete: %s", memif_strerror (err));
+
+  return 0;
+}
+
+int
+icmpr_add_external_region (void * *addr, uint32_t size, int *fd,
+			   void *private_ctx)
+{
+
+  int rfd;
+  void *raddr;
+  int err;
+
+  rfd = memfd_create ("memif region 1", MFD_ALLOW_SEALING);
+
+  fcntl (rfd, F_ADD_SEALS, F_SEAL_SHRINK);
+
+  err = ftruncate (rfd, size);
+
+  raddr = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, rfd, 0);
+
+  *addr = raddr;
+  *fd = rfd;
+
+  return 0;
+}
+
+void *
+icmpr_get_external_region_addr (uint32_t size, int fd, void *private_ctx)
+{
+  return mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+}
+
+int
+icmpr_del_external_region (void *addr, uint32_t size, int fd,
+			   void *private_ctx)
+{
+  munmap (addr, size);
+  if (fd > 0)
+    close (fd);
+  fd = -1;
+  return 0;
+}
+
+int
+on_interrupt (memif_conn_handle_t conn, void *private_ctx, uint16_t qid)
+{
+  long index = *((long *) private_ctx);
+  memif_connection_t *c = &memif_connection[index];
+  if (c->index != index)
+    {
+      INFO ("invalid context: %ld/%u", index, c->index);
+      return 0;
+    }
+
+  int err = MEMIF_ERR_SUCCESS, ret_val;
+  uint16_t rx = 0, tx = 0;
+  uint16_t fb = 0;
+  int i = 0;
+  int j = 0;
+
+  do
+    {
+      err = memif_rx_burst (c->conn, qid, c->rx_bufs, MAX_MEMIF_BUFS, &rx);
+      ret_val = err;
+      c->rx_counter += rx;
+      if ((err != MEMIF_ERR_SUCCESS) && (err != MEMIF_ERR_NOBUF))
+	{
+	  INFO ("memif_rx_burst: %s", memif_strerror (err));
+	  goto error;
+	}
+      i = 0;
+      memset (c->tx_bufs, 0, sizeof (memif_buffer_t) * rx);
+      err = memif_buffer_alloc (c->conn, qid, c->tx_bufs, rx, &tx, 128);
+      if ((err != MEMIF_ERR_SUCCESS) && (err != MEMIF_ERR_NOBUF_RING))
+	{
+	  INFO ("memif_buffer_alloc: %s", memif_strerror (err));
+	  goto error;
+	}
+      j = 0;
+      c->tx_err_counter += rx - tx;
+
+      while (tx)
+	{
+	  resolve_packet ((void *) (c->rx_bufs + i)->data,
+			  (c->rx_bufs + i)->len,
+			  (void *) (c->tx_bufs + j)->data,
+			  &(c->tx_bufs + j)->len, c->ip_addr);
+	  i++;
+	  j++;
+	  tx--;
+	}
+
+      err = memif_refill_queue (c->conn, qid, rx, 0);
+      if (err != MEMIF_ERR_SUCCESS)
+	INFO ("memif_buffer_free: %s", memif_strerror (err));
+      rx -= rx;
+
+      DBG ("%u/%u alloc/free buffers", rx, MAX_MEMIF_BUFS - rx);
+
+      err = memif_tx_burst (c->conn, qid, c->tx_bufs, j, &tx);
+      if (err != MEMIF_ERR_SUCCESS)
+	{
+	  INFO ("memif_tx_burst: %s", memif_strerror (err));
+	  goto error;
+	}
+      c->tx_counter += tx;
+    }
+  while (ret_val == MEMIF_ERR_NOBUF);
+
+  return 0;
+
+error:
+  err = memif_refill_queue (c->conn, qid, rx, 0);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_buffer_free: %s", memif_strerror (err));
+  c->rx_buf_num -= rx;
+  DBG ("freed %d buffers. %u/%u alloc/free buffers", fb, c->rx_buf_num,
+       MAX_MEMIF_BUFS - c->rx_buf_num);
+  return 0;
+}
+
+int
+on_interrupt1 (memif_conn_handle_t conn, void *private_ctx, uint16_t qid)
+{
+  long index = *((long *) private_ctx);
+  memif_connection_t *c = &memif_connection[index];
+  if (c->index != index)
+    {
+      INFO ("invalid context: %ld/%u", index, c->index);
+      return 0;
+    }
+
+  int err = MEMIF_ERR_SUCCESS, ret_val;
+  int i;
+  uint16_t rx, tx;
+  uint16_t fb;
+  uint16_t pck_seq;
+
+  do
+    {
+      /* receive data from shared memory buffers */
+      err = memif_rx_burst (c->conn, qid, c->rx_bufs, MAX_MEMIF_BUFS, &rx);
+      ret_val = err;
+      if ((err != MEMIF_ERR_SUCCESS) && (err != MEMIF_ERR_NOBUF))
+	{
+	  INFO ("memif_rx_burst: %s", memif_strerror (err));
+	  goto error;
+	}
+      c->rx_buf_num += rx;
+      c->rx_counter += rx;
+
+      for (i = 0; i < rx; i++)
+	{
+	  if (((struct ether_header *) (c->rx_bufs + i)->data)->ether_type ==
+	      0x0608)
+	    {
+	      err =
+		memif_buffer_alloc (c->conn, qid, c->tx_bufs, 1, &tx, 128);
+	      if ((err != MEMIF_ERR_SUCCESS) && (err != MEMIF_ERR_NOBUF_RING))
+		{
+		  INFO ("memif_buffer_alloc: %s", memif_strerror (err));
+		  goto error;
+		}
+	      resolve_packet ((void *) (c->rx_bufs + i)->data,
+			      (c->rx_bufs + i)->len,
+			      (void *) (c->tx_bufs + i)->data,
+			      &(c->tx_bufs + i)->len, c->ip_addr);
+	      err =
+		memif_tx_burst (c->conn, qid, c->tx_bufs, c->tx_buf_num, &tx);
+	      if (err != MEMIF_ERR_SUCCESS)
+		INFO ("memif_tx_burst: %s", memif_strerror (err));
+	      c->tx_buf_num -= tx;
+	      c->tx_counter += tx;
+	    }
+	}
+
+      err = memif_refill_queue (c->conn, qid, rx, 0);
+      if (err != MEMIF_ERR_SUCCESS)
+	INFO ("memif_buffer_free: %s", memif_strerror (err));
+      c->rx_buf_num -= rx;
+
+
+    }
+  while (ret_val == MEMIF_ERR_NOBUF);
+
+  return 0;
+
+error:
+  err = memif_refill_queue (c->conn, qid, rx, 0);
+  if (err != MEMIF_ERR_SUCCESS)
+    INFO ("memif_buffer_free: %s", memif_strerror (err));
+  c->rx_buf_num -= rx;
+  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 (long index, long mode, char *s)
+{
+  if (index >= MAX_CONNS)
+    {
+      INFO ("connection array overflow");
+      return 0;
+    }
+  if (index < 0)
+    {
+      INFO ("...");
+      return 0;
+    }
+  memif_connection_t *c = &memif_connection[index];
+
+  memif_conn_args_t args;
+  int fd = -1;
+  memset (&args, 0, sizeof (args));
+  args.is_master = mode;
+  args.log2_ring_size = 11;
+  args.buffer_size = 2048;
+  args.num_s2m_rings = 1;
+  args.num_m2s_rings = 1;
+  strncpy ((char *) args.interface_name, IF_NAME, strlen (IF_NAME));
+  args.mode = 0;
+  args.interface_id = index;
+
+  int err;
+  if (s == NULL)
+    {
+      err = memif_create (&c->conn,
+			  &args, on_connect, on_disconnect, on_interrupt,
+			  &ctx[index]);
+      if (err != MEMIF_ERR_SUCCESS)
+	{
+	  INFO ("memif_create: %s", memif_strerror (err));
+	  return 0;
+	}
+    }
+  else
+    {
+      if (strncmp (s, "1", 1) == 0)
+	{
+	  err = memif_create (&c->conn,
+			      &args, on_connect, on_disconnect, on_interrupt1,
+			      &ctx[index]);
+	  if (err != MEMIF_ERR_SUCCESS)
+	    {
+	      INFO ("memif_create: %s", memif_strerror (err));
+	      return 0;
+	    }
+	}
+      else
+	{
+	  INFO ("Unknown interrupt descriptor");
+	  goto done;
+	}
+    }
+
+  c->index = index;
+  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] = c->index + 1;
+  c->ip_addr[3] = 2;
+
+done:
+  return 0;
+}
+
+void *
+icmpr_send_proc (void *data)
+{
+  icmpr_thread_data_t *d = (icmpr_thread_data_t *) data;
+  int index = d->index;
+  uint64_t count = d->packet_num;
+  memif_connection_t *c = &memif_connection[index];
+  if (c->conn == NULL)
+    {
+      INFO ("No connection at index %d.", index);
+      goto error;
+    }
+  uint16_t tx, i;
+  int err = MEMIF_ERR_SUCCESS;
+  uint32_t seq = 0;
+  struct timespec start, end;
+  memset (&start, 0, sizeof (start));
+  memset (&end, 0, sizeof (end));
+
+  timespec_get (&start, TIME_UTC);
+  while (count)
+    {
+      i = 0;
+      err =
+	memif_buffer_alloc (c->conn, 0, c->tx_bufs,
+			    MAX_MEMIF_BUFS > count ? count : MAX_MEMIF_BUFS,
+			    &tx, 128);
+
+      if ((err != MEMIF_ERR_SUCCESS) && (err != MEMIF_ERR_NOBUF_RING))
+	{
+	  INFO ("memif_buffer_alloc: %s", memif_strerror (err));
+	  goto error;
+	}
+      c->tx_buf_num += tx;
+
+      while (tx)
+	{
+	  while (tx > 4)
+	    {
+	      generate_packet ((void *) c->tx_bufs[i].data,
+			       &c->tx_bufs[i].len, c->ip_addr, d->ip_daddr,
+			       d->hw_daddr, seq++);
+	      generate_packet ((void *) c->tx_bufs[i + 1].data,
+			       &c->tx_bufs[i + 1].len, c->ip_addr,
+			       d->ip_daddr, d->hw_daddr, seq++);
+	      generate_packet ((void *) c->tx_bufs[i + 2].data,
+			       &c->tx_bufs[i + 2].len, c->ip_addr,
+			       d->ip_daddr, d->hw_daddr, seq++);
+	      generate_packet ((void *) c->tx_bufs[i + 3].data,
+			       &c->tx_bufs[i + 3].len, c->ip_addr,
+			       d->ip_daddr, d->hw_daddr, seq++);
+	      i += 4;
+	      tx -= 4;
+	    }
+	  generate_packet ((void *) c->tx_bufs[i].data, &c->tx_bufs[i].len,
+			   c->ip_addr, d->ip_daddr, d->hw_daddr, seq++);
+	  i++;
+	  tx--;
+	}
+
+      err = memif_tx_burst (c->conn, 0, 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;
+      c->tx_counter += tx;
+      count -= tx;
+    }
+
+  timespec_get (&end, TIME_UTC);
+  INFO ("\n\nPacket sequence finished!\nSeq len: %u", seq);
+  uint64_t t1 = end.tv_sec - start.tv_sec;
+  uint64_t t2;
+  if (end.tv_nsec > start.tv_nsec)
+    {
+      t2 = end.tv_nsec - start.tv_nsec;
+    }
+  else
+    {
+      t2 = start.tv_nsec - end.tv_nsec;
+      t1--;
+    }
+  c->t_sec = t1;
+  c->t_nsec = t2;
+  double tmp = t1;
+  tmp += t2 / 1e+9;
+  tmp = seq / tmp;
+  INFO ("Seq time: %lus %luns\nAverage pps: %f", t1, t2, tmp);
+
+error:
+  INFO ("Thread exiting...");
+  pthread_exit (NULL);
+}
+
+
+int
+icmpr_send (long index, long packet_num, char *hw, char *ip)
+{
+  if (index >= MAX_CONNS)
+    {
+      INFO ("connection array overflow");
+      return 0;
+    }
+  if (index < 0)
+    {
+      INFO ("...");
+      return 0;
+    }
+  memif_connection_t *c = &memif_connection[index];
+  if (c->conn == NULL)
+    return -1;
+  int err, i;
+  uint16_t tx = 0, rx = 0;
+  char *end, *ui;
+  uint8_t tmp[6];
+  icmpr_thread_data_t *data = &icmpr_thread_data[index];
+  data->index = index;
+  data->packet_num = packet_num;
+
+  ui = strtok (ip, ".");
+  if (ui == NULL)
+    goto error;
+  tmp[0] = strtol (ui, &end, 10);
+  ui = strtok (NULL, ".");
+  if (ui == NULL)
+    goto error;
+  tmp[1] = strtol (ui, &end, 10);
+  ui = strtok (NULL, ".");
+  if (ui == NULL)
+    goto error;
+  tmp[2] = strtol (ui, &end, 10);
+  ui = strtok (NULL, ".");
+  if (ui == NULL)
+    goto error;
+  tmp[3] = strtol (ui, &end, 10);
+
+  data->ip_daddr[0] = tmp[0];
+  data->ip_daddr[1] = tmp[1];
+  data->ip_daddr[2] = tmp[2];
+  data->ip_daddr[3] = tmp[3];
+
+  ui = strtok (hw, ":");
+  if (ui == NULL)
+    goto error;
+  tmp[0] = strtol (ui, &end, 16);
+  ui = strtok (NULL, ":");
+  if (ui == NULL)
+    goto error;
+  tmp[1] = strtol (ui, &end, 16);
+  ui = strtok (NULL, ":");
+  if (ui == NULL)
+    goto error;
+  tmp[2] = strtol (ui, &end, 16);
+  ui = strtok (NULL, ":");
+  if (ui == NULL)
+    goto error;
+  tmp[3] = strtol (ui, &end, 16);
+  ui = strtok (NULL, ":");
+  if (ui == NULL)
+    goto error;
+  tmp[4] = strtol (ui, &end, 16);
+  ui = strtok (NULL, ":");
+  if (ui == NULL)
+    goto error;
+  tmp[5] = strtol (ui, &end, 16);
+
+  pthread_create (&thread[index], NULL, icmpr_send_proc, (void *) data);
+  return 0;
+
+error:
+  INFO ("Invalid input\n");
+  return 0;
+}
+
+int
+user_input_handler ()
+{
+  char *in = (char *) malloc (256);
+  char *ui = fgets (in, 256, stdin);
+  char *end;
+  long a;
+
+  if (in[0] == '\n')
+    goto done;
+
+  ui = strtok (in, " ");
+
+  if (strncmp (ui, "exit", 4) == 0)
+    {
+      free (in);
+      icmpr_free ();
+      exit (EXIT_SUCCESS);
+    }
+  else if (strncmp (ui, "help", 4) == 0)
+    {
+      print_help ();
+      goto done;
+    }
+  else if (strncmp (ui, "conn", 4) == 0)
+    {
+      ui = strtok (NULL, " ");
+      if (ui != NULL)
+	a = strtol (ui, &end, 10);
+      else
+	{
+	  INFO ("expected id");
+	  goto done;
+	}
+      ui = strtok (NULL, " ");
+      if (ui != NULL)
+	icmpr_memif_create (a, strtol (ui, &end, 10), strtok (NULL, " "));
+      else
+	INFO ("expected mode <0|1>");
+      goto done;
+    }
+  else if (strncmp (ui, "del", 3) == 0)
+    {
+      ui = strtok (NULL, " ");
+      if (ui != NULL)
+	icmpr_memif_delete (strtol (ui, &end, 10));
+      else
+	{
+	  INFO ("expected id");
+	  goto done;
+	}
+    }
+  else if (strncmp (ui, "send", 4) == 0)
+    {
+      ui = strtok (NULL, " ");
+      if (ui != NULL)
+	a = strtol (ui, &end, 10);
+      else
+	{
+	  INFO ("expected id");
+	  goto done;
+	}
+      ui = strtok (NULL, " ");
+      if (ui != NULL)
+	icmpr_send (a, strtol (ui, &end, 10), strtok (NULL, " "),
+		    strtok (NULL, " "));
+      else
+	INFO ("expected count");
+      goto done;
+    }
+  else if (strncmp (ui, "show", 4) == 0)
+    {
+      print_memif_details ();
+      goto done;
+    }
+
+done:
+  free (in);
+  return 0;
+}
+
+int
+poll_event (int timeout)
+{
+  struct epoll_event evt, *e;
+  int app_err = 0, memif_err = 0, en = 0;
+  int tmp, nfd;
+  uint32_t events = 0;
+  memset (&evt, 0, sizeof (evt));
+  evt.events = EPOLLIN | EPOLLOUT;
+  sigset_t sigset;
+  sigemptyset (&sigset);
+  en = epoll_pwait (epfd, &evt, 1, timeout, &sigset);
+  /* id event polled */
+  if (en < 0)
+    {
+      DBG ("epoll_pwait: %s", strerror (errno));
+      return -1;
+    }
+  if (en > 0)
+    {
+      /* this app does not use any other file descriptors than stds and memif control fds */
+      if (evt.data.fd > 2)
+	{
+	  /* event of memif control fd */
+	  /* convert epolle events to memif events */
+	  if (evt.events & EPOLLIN)
+	    events |= MEMIF_FD_EVENT_READ;
+	  if (evt.events & EPOLLOUT)
+	    events |= MEMIF_FD_EVENT_WRITE;
+	  if (evt.events & EPOLLERR)
+	    events |= MEMIF_FD_EVENT_ERROR;
+	  memif_err = memif_control_fd_handler (evt.data.fd, events);
+	  if (memif_err != MEMIF_ERR_SUCCESS)
+	    INFO ("memif_control_fd_handler: %s", memif_strerror (memif_err));
+	}
+      else if (evt.data.fd == 0)
+	{
+	  app_err = user_input_handler ();
+	}
+      else
+	{
+	  DBG ("unexpected event at memif_epfd. fd %d", evt.data.fd);
+	}
+    }
+
+  if ((app_err < 0) || (memif_err < 0))
+    {
+      if (app_err < 0)
+	DBG ("user input handler error");
+      if (memif_err < 0)
+	DBG ("memif control fd handler error");
+      return -1;
+    }
+
+  return 0;
+}
+
+int
+main ()
+{
+  epfd = epoll_create (1);
+  add_epoll_fd (0, EPOLLIN);
+
+  /* initialize memory interface */
+  int err, i;
+  /* 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 (control_fd_update, APP_NAME, NULL, NULL, NULL);
+  if (err != MEMIF_ERR_SUCCESS)
+    {
+      INFO ("memif_init: %s", memif_strerror (err));
+      icmpr_free ();
+      exit (-1);
+    }
+
+  for (i = 0; i < MAX_CONNS; i++)
+    {
+      memset (&memif_connection[i], 0, sizeof (memif_connection_t));
+      ctx[i] = i;
+    }
+
+  memif_register_external_region (icmpr_add_external_region,
+				  icmpr_get_external_region_addr,
+				  icmpr_del_external_region, NULL);
+
+  print_help ();
+
+  /* main loop */
+  while (1)
+    {
+      if (poll_event (-1) < 0)
+	{
+	  DBG ("poll_event error!");
+	}
+    }
+}
diff --git a/extras/libmemif/examples/icmp_responder-epoll/main.c b/extras/libmemif/examples/icmp_responder-epoll/main.c
index fd354a3..70095dd 100644
--- a/extras/libmemif/examples/icmp_responder-epoll/main.c
+++ b/extras/libmemif/examples/icmp_responder-epoll/main.c
@@ -86,6 +86,8 @@
 #define MAX_MEMIF_BUFS  256
 #define MAX_CONNS       50
 
+#define ICMPR_HEADROOM	64
+
 int epfd;
 int out_fd;
 uint8_t enable_log;
@@ -282,7 +284,7 @@
 on_connect (memif_conn_handle_t conn, void *private_ctx)
 {
   INFO ("memif connected!");
-  memif_refill_queue (conn, 0, -1, 0);
+  memif_refill_queue (conn, 0, -1, ICMPR_HEADROOM);
   enable_log = 1;
   return 0;
 }
@@ -406,13 +408,12 @@
 	  tx--;
 	}
 
-      err = memif_refill_queue (c->conn, qid, rx, 0);
+      err = memif_refill_queue (c->conn, qid, rx, ICMPR_HEADROOM);
       if (err != MEMIF_ERR_SUCCESS)
 	INFO ("memif_buffer_free: %s", memif_strerror (err));
       rx -= rx;
 
-      DBG ("freed %d buffers. %u/%u alloc/free buffers",
-	   rx, rx, MAX_MEMIF_BUFS - rx);
+      DBG ("%u/%u alloc/free buffers", rx, MAX_MEMIF_BUFS - rx);
 
       err = memif_tx_burst (c->conn, qid, c->tx_bufs, j, &tx);
       if (err != MEMIF_ERR_SUCCESS)
@@ -428,7 +429,7 @@
   return 0;
 
 error:
-  err = memif_refill_queue (c->conn, qid, rx, 0);
+  err = memif_refill_queue (c->conn, qid, rx, ICMPR_HEADROOM);
   if (err != MEMIF_ERR_SUCCESS)
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num -= rx;
@@ -514,7 +515,7 @@
 	    }
 	  /* mark memif buffers and shared memory buffers as free */
 	  /* free processed buffers */
-	  err = memif_refill_queue (c->conn, qid, j, 0);
+	  err = memif_refill_queue (c->conn, qid, j, ICMPR_HEADROOM);
 	  if (err != MEMIF_ERR_SUCCESS)
 	    INFO ("memif_buffer_free: %s", memif_strerror (err));
 	  rx -= j;
@@ -540,7 +541,7 @@
   return 0;
 
 error:
-  err = memif_refill_queue (c->conn, qid, rx, 0);
+  err = memif_refill_queue (c->conn, qid, rx, ICMPR_HEADROOM);
   if (err != MEMIF_ERR_SUCCESS)
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num -= rx;
@@ -597,7 +598,7 @@
 	    }
 	}
 
-      err = memif_refill_queue (c->conn, qid, rx, 0);
+      err = memif_refill_queue (c->conn, qid, rx, ICMPR_HEADROOM);
       if (err != MEMIF_ERR_SUCCESS)
 	INFO ("memif_buffer_free: %s", memif_strerror (err));
       c->rx_buf_num -= rx;
@@ -609,7 +610,7 @@
   return 0;
 
 error:
-  err = memif_refill_queue (c->conn, qid, rx, 0);
+  err = memif_refill_queue (c->conn, qid, rx, ICMPR_HEADROOM);
   if (err != MEMIF_ERR_SUCCESS)
     INFO ("memif_buffer_free: %s", memif_strerror (err));
   c->rx_buf_num -= rx;
@@ -992,6 +993,7 @@
       count -= tx;
     }
   timespec_get (&end, TIME_UTC);
+  printf ("\n\n");
   INFO ("Pakcet sequence finished!");
   INFO ("Seq len: %u", seq);
   uint64_t t1 = end.tv_sec - start.tv_sec;
@@ -1297,7 +1299,7 @@
   /* 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 (control_fd_update, APP_NAME, NULL, NULL);
+  err = memif_init (control_fd_update, APP_NAME, NULL, NULL, NULL);
   if (err != MEMIF_ERR_SUCCESS)
     {
       INFO ("memif_init: %s", memif_strerror (err));
diff --git a/extras/libmemif/examples/icmp_responder-mt/main.c b/extras/libmemif/examples/icmp_responder-mt/main.c
index c4ac907..8fa64cf 100644
--- a/extras/libmemif/examples/icmp_responder-mt/main.c
+++ b/extras/libmemif/examples/icmp_responder-mt/main.c
@@ -894,7 +894,7 @@
   /* 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 (control_fd_update, APP_NAME, NULL, NULL);
+  err = memif_init (control_fd_update, APP_NAME, NULL, NULL, NULL);
   if (err != MEMIF_ERR_SUCCESS)
     INFO ("memif_init: %s", memif_strerror (err));
 
diff --git a/extras/libmemif/examples/icmp_responder/main.c b/extras/libmemif/examples/icmp_responder/main.c
index 5e78acd..fa7bcb9 100644
--- a/extras/libmemif/examples/icmp_responder/main.c
+++ b/extras/libmemif/examples/icmp_responder/main.c
@@ -395,7 +395,7 @@
   /* 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, NULL, NULL);
+  err = memif_init (NULL, APP_NAME, NULL, NULL, NULL);
   if (err != MEMIF_ERR_SUCCESS)
     INFO ("memif_init: %s", memif_strerror (err));