sock_test_server.c

Go to the documentation of this file.

/*
 * Copyright (c) 2017-2019 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 <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <ctype.h>
#include <hs_apps/vcl/sock_test.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/epoll.h>
#include <sys/un.h>

#define SOCK_SERVER_MAX_TEST_CONN  10
#define SOCK_SERVER_MAX_EPOLL_EVENTS 10

typedef struct
{
  uint8_t is_alloc;
  int fd;
  uint8_t *buf;
  uint32_t buf_size;
  vcl_test_cfg_t cfg;
  vcl_test_stats_t stats;
} sock_server_conn_t;

typedef struct
{
  uint32_t port;
  uint32_t address_ip6;
  uint32_t transport_udp;
} sock_server_cfg_t;

typedef struct
{
  int listen_fd;
  sock_server_cfg_t cfg;
  int epfd;
  struct epoll_event listen_ev;
  struct epoll_event wait_events[SOCK_SERVER_MAX_EPOLL_EVENTS];
  int af_unix_listen_fd;
  int af_unix_fd;
  struct epoll_event af_unix_listen_ev;
  struct sockaddr_un serveraddr;
  uint32_t af_unix_xacts;
  size_t num_conn;
  size_t conn_pool_size;
  sock_server_conn_t *conn_pool;
  int nfds;
  fd_set rd_fdset;
  fd_set wr_fdset;
  struct timeval timeout;
} sock_server_main_t;

sock_server_main_t sock_server_main;

static inline void
conn_pool_expand (size_t expand_size)
{
  sock_server_main_t *ssm = &sock_server_main;
  sock_server_conn_t *conn_pool;
  size_t new_size = ssm->conn_pool_size + expand_size;
  int i;

  conn_pool = realloc (ssm->conn_pool, new_size * sizeof (*ssm->conn_pool));
  if (conn_pool)
    {
      for (i = ssm->conn_pool_size; i < new_size; i++)
        {
          sock_server_conn_t *conn = &conn_pool[i];
          memset (conn, 0, sizeof (*conn));
          vcl_test_cfg_init (&conn->cfg);
          vcl_test_buf_alloc (&conn->cfg, 1 /* is_rxbuf */ ,
                              &conn->buf, &conn->buf_size);
          conn->cfg.txbuf_size = conn->cfg.rxbuf_size;
        }

      ssm->conn_pool = conn_pool;
      ssm->conn_pool_size = new_size;
    }
  else
    {
      int errno_val = errno;
      perror ("ERROR in conn_pool_expand()");
      fprintf (stderr, "SERVER: ERROR: Memory allocation "
               "failed (errno = %d)!\n", errno_val);
    }
}

static inline sock_server_conn_t *
conn_pool_alloc (void)
{
  sock_server_main_t *ssm = &sock_server_main;
  int i;

  for (i = 0; i < ssm->conn_pool_size; i++)
    {
      if (!ssm->conn_pool[i].is_alloc)
        {
          ssm->conn_pool[i].is_alloc = 1;
          return (&ssm->conn_pool[i]);
        }
    }

  return 0;
}

static inline void
conn_pool_free (sock_server_conn_t * conn)
{
  conn->fd = 0;
  conn->is_alloc = 0;
}

static inline void
sync_config_and_reply (sock_server_conn_t * conn, vcl_test_cfg_t * rx_cfg)
{
  conn->cfg = *rx_cfg;
  vcl_test_buf_alloc (&conn->cfg, 1 /* is_rxbuf */ ,
                      &conn->buf, &conn->buf_size);
  conn->cfg.txbuf_size = conn->cfg.rxbuf_size;

  if (conn->cfg.verbose)
    {
      printf ("\nSERVER (fd %d): Replying to cfg message!\n", conn->fd);
      vcl_test_cfg_dump (&conn->cfg, 0 /* is_client */ );
    }
  (void) sock_test_write (conn->fd, (uint8_t *) & conn->cfg,
                          sizeof (conn->cfg), NULL, conn->cfg.verbose);
}

static void
stream_test_server_start_stop (sock_server_conn_t * conn,
                               vcl_test_cfg_t * rx_cfg)
{
  sock_server_main_t *ssm = &sock_server_main;
  int client_fd = conn->fd;
  vcl_test_t test = rx_cfg->test;

  if (rx_cfg->ctrl_handle == conn->fd)
    {
      int i;
      clock_gettime (CLOCK_REALTIME, &conn->stats.stop);

      for (i = 0; i < ssm->conn_pool_size; i++)
        {
          sock_server_conn_t *tc = &ssm->conn_pool[i];

          if (tc->cfg.ctrl_handle == conn->fd)
            {
              vcl_test_stats_accumulate (&conn->stats, &tc->stats);

              if (conn->cfg.verbose)
                {
                  static char buf[64];

                  snprintf (buf, sizeof (buf), "SERVER (fd %d) RESULTS",
                            tc->fd);
                  vcl_test_stats_dump (buf, &tc->stats, 1 /* show_rx */ ,
                                       test == VCL_TEST_TYPE_BI
                                       /* show tx */ ,
                                       conn->cfg.verbose);
                }
            }
        }

      vcl_test_stats_dump ("SERVER RESULTS", &conn->stats, 1 /* show_rx */ ,
                           (test == VCL_TEST_TYPE_BI) /* show_tx */ ,
                           conn->cfg.verbose);
      vcl_test_cfg_dump (&conn->cfg, 0 /* is_client */ );
      if (conn->cfg.verbose)
        {
          printf ("  sock server main\n"
                  VCL_TEST_SEPARATOR_STRING
                  "       buf:  %p\n"
                  "  buf size:  %u (0x%08x)\n"
                  VCL_TEST_SEPARATOR_STRING,
                  conn->buf, conn->buf_size, conn->buf_size);
        }

      sync_config_and_reply (conn, rx_cfg);
      printf ("\nSERVER (fd %d): %s-directional Stream Test Complete!\n"
              SOCK_TEST_BANNER_STRING "\n", conn->fd,
              test == VCL_TEST_TYPE_BI ? "Bi" : "Uni");
    }
  else
    {
      printf ("\n" SOCK_TEST_BANNER_STRING
              "SERVER (fd %d): %s-directional Stream Test!\n"
              "  Sending client the test cfg to start streaming data...\n",
              client_fd, test == VCL_TEST_TYPE_BI ? "Bi" : "Uni");

      rx_cfg->ctrl_handle = (rx_cfg->ctrl_handle == ~0) ? conn->fd :
        rx_cfg->ctrl_handle;

      sync_config_and_reply (conn, rx_cfg);

      /* read the 1st chunk, record start time */
      memset (&conn->stats, 0, sizeof (conn->stats));
      clock_gettime (CLOCK_REALTIME, &conn->stats.start);
    }
}


static inline void
stream_test_server (sock_server_conn_t * conn, int rx_bytes)
{
  int client_fd = conn->fd;
  vcl_test_t test = conn->cfg.test;

  if (test == VCL_TEST_TYPE_BI)
    (void) sock_test_write (client_fd, conn->buf, rx_bytes, &conn->stats,
                            conn->cfg.verbose);

  if (conn->stats.rx_bytes >= conn->cfg.total_bytes)
    {
      clock_gettime (CLOCK_REALTIME, &conn->stats.stop);
    }
}

static inline void
af_unix_echo (void)
{
  sock_server_main_t *ssm = &sock_server_main;
  int af_unix_client_fd;
  int rv;
  int errno_val;
  uint8_t buffer[256];
  size_t nbytes = strlen (SOCK_TEST_MIXED_EPOLL_DATA) + 1;

#if HAVE_ACCEPT4
  af_unix_client_fd = accept4 (ssm->af_unix_listen_fd,
                               (struct sockaddr *) NULL, NULL, NULL);
#else
  af_unix_client_fd = accept (ssm->af_unix_listen_fd,
                              (struct sockaddr *) NULL, NULL);
#endif
  if (af_unix_client_fd < 0)
    {
      errno_val = errno;
      perror ("ERROR in af_unix_accept()");
      fprintf (stderr, "SERVER: ERROR: accept failed "
               "(errno = %d)!\n", errno_val);
      return;
    }

  printf ("SERVER: Got an AF_UNIX connection -- fd = %d (0x%08x)!\n",
          af_unix_client_fd, af_unix_client_fd);

  memset (buffer, 0, sizeof (buffer));

  rv = read (af_unix_client_fd, buffer, nbytes);
  if (rv < 0)
    {
      errno_val = errno;
      perror ("ERROR in af_unix_echo(): read() failed");
      fprintf (stderr, "SERVER: ERROR: read(af_unix_client_fd %d (0x%x), "
               "nbytes %lu) failed (errno = %d)!\n", af_unix_client_fd,
               af_unix_client_fd, nbytes, errno_val);
      goto done;
    }
  /* Make the buffer is NULL-terminated. */
  buffer[sizeof (buffer) - 1] = 0;
  printf ("SERVER (AF_UNIX): RX (%d bytes) - '%s'\n", rv, buffer);

  if (!strncmp (SOCK_TEST_MIXED_EPOLL_DATA, (const char *) buffer, nbytes))
    {
      rv = write (af_unix_client_fd, buffer, nbytes);
      if (rv < 0)
        {
          errno_val = errno;
          perror ("ERROR in af_unix_echo(): write() failed");
          fprintf (stderr,
                   "SERVER: ERROR: write(af_unix_client_fd %d (0x%x), "
                   "\"%s\", nbytes %ld) failed (errno = %d)!\n",
                   af_unix_client_fd, af_unix_client_fd, buffer, nbytes,
                   errno_val);
          goto done;
        }
      printf ("SERVER (AF_UNIX): TX (%d bytes) - '%s'\n", rv, buffer);
      ssm->af_unix_xacts++;
    }
done:
  close (af_unix_client_fd);
}

static inline void
new_client (void)
{
  sock_server_main_t *ssm = &sock_server_main;
  int client_fd;
  sock_server_conn_t *conn;

  if (ssm->conn_pool_size < (ssm->num_conn + SOCK_SERVER_MAX_TEST_CONN + 1))
    conn_pool_expand (SOCK_SERVER_MAX_TEST_CONN + 1);

  conn = conn_pool_alloc ();
  if (!conn)
    {
      fprintf (stderr, "\nSERVER: ERROR: No free connections!\n");
      return;
    }

#if HAVE_ACCEPT4
  client_fd = accept4 (ssm->listen_fd, (struct sockaddr *) NULL, NULL, NULL);
#else
  client_fd = accept (ssm->listen_fd, (struct sockaddr *) NULL, NULL);
#endif
  if (client_fd < 0)
    {
      int errno_val;
      errno_val = errno;
      perror ("ERROR in new_client()");
      fprintf (stderr, "SERVER: ERROR: accept failed "
               "(errno = %d)!\n", errno_val);
      return;
    }

  printf ("SERVER: Got a connection -- fd = %d (0x%08x)!\n",
          client_fd, client_fd);

  conn->fd = client_fd;

  struct epoll_event ev;
  int rv;

  ev.events = EPOLLIN;
  ev.data.u64 = conn - ssm->conn_pool;
  rv = epoll_ctl (ssm->epfd, EPOLL_CTL_ADD, client_fd, &ev);

  if (rv < 0)
    {
      int errno_val;
      errno_val = errno;
      perror ("ERROR in new_client()");
      fprintf (stderr, "SERVER: ERROR: epoll_ctl failed (errno = %d)!\n",
               errno_val);
    }
  else
    ssm->nfds++;
}

static int
socket_server_echo_af_unix_init (sock_server_main_t * ssm)
{
  int rv, errno_val;

  if (ssm->af_unix_listen_fd > 0)
    return 0;

  unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
  ssm->af_unix_listen_fd = socket (AF_UNIX, SOCK_STREAM, 0);
  if (ssm->af_unix_listen_fd < 0)
    {
      errno_val = errno;
      perror ("ERROR in main(): socket(AF_UNIX) failed");
      fprintf (stderr,
               "SERVER: ERROR: socket(AF_UNIX, SOCK_STREAM, 0) failed "
               "(errno = %d)!\n", errno_val);
      return ssm->af_unix_listen_fd;
    }

  memset (&ssm->serveraddr, 0, sizeof (ssm->serveraddr));
  ssm->serveraddr.sun_family = AF_UNIX;
  strncpy (ssm->serveraddr.sun_path, SOCK_TEST_AF_UNIX_FILENAME,
           sizeof (ssm->serveraddr.sun_path));

  rv = bind (ssm->af_unix_listen_fd, (struct sockaddr *) &ssm->serveraddr,
             SUN_LEN (&ssm->serveraddr));
  if (rv < 0)
    {
      errno_val = errno;
      perror ("ERROR in main(): bind(SOCK_TEST_AF_UNIX_FILENAME) failed");
      fprintf (stderr, "SERVER: ERROR: bind() fd %d, \"%s\": "
               "failed (errno = %d)!\n", ssm->af_unix_listen_fd,
               SOCK_TEST_AF_UNIX_FILENAME, errno_val);
      close (ssm->af_unix_listen_fd);
      unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
      return rv;
    }

  rv = listen (ssm->af_unix_listen_fd, 10);
  if (rv < 0)
    {
      errno_val = errno;
      perror ("ERROR in main(): listen(AF_UNIX) failed");
      fprintf (stderr, "SERVER: ERROR: listen() fd %d, \"%s\": "
               "failed (errno = %d)!\n", ssm->af_unix_listen_fd,
               SOCK_TEST_AF_UNIX_FILENAME, errno_val);
      close (ssm->af_unix_listen_fd);
      unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
      return rv;
    }

  ssm->af_unix_listen_ev.events = EPOLLIN;
  ssm->af_unix_listen_ev.data.u32 = SOCK_TEST_AF_UNIX_ACCEPT_DATA;
  rv = epoll_ctl (ssm->epfd, EPOLL_CTL_ADD, ssm->af_unix_listen_fd,
                  &ssm->af_unix_listen_ev);
  if (rv < 0)
    {
      errno_val = errno;
      perror ("ERROR in main(): mixed epoll_ctl(EPOLL_CTL_ADD)");
      fprintf (stderr, "SERVER: ERROR: mixed epoll_ctl(epfd %d (0x%x), "
               "EPOLL_CTL_ADD, af_unix_listen_fd %d (0x%x), EPOLLIN) failed "
               "(errno = %d)!\n", ssm->epfd, ssm->epfd,
               ssm->af_unix_listen_fd, ssm->af_unix_listen_fd, errno_val);
      close (ssm->af_unix_listen_fd);
      unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);
      return rv;
    }

  return 0;
}

void
print_usage_and_exit (void)
{
  fprintf (stderr,
           "sock_test_server [OPTIONS] <port>\n"
           "  OPTIONS\n"
           "  -h               Print this message and exit.\n"
           "  -6               Use IPv6\n"
           "  -u               Use UDP transport layer\n");
  exit (1);
}

int
main (int argc, char **argv)
{
  sock_server_main_t *ssm = &sock_server_main;
  int client_fd, rv, main_rv = 0;
  int tx_bytes, rx_bytes, nbytes;
  sock_server_conn_t *conn;
  vcl_test_cfg_t *rx_cfg;
  uint32_t xtra = 0;
  uint64_t xtra_bytes = 0;
  struct sockaddr_storage servaddr;
  int errno_val;
  int c, v, i;
  uint16_t port = VCL_TEST_SERVER_PORT;
  uint32_t servaddr_size;

  opterr = 0;
  while ((c = getopt (argc, argv, "6D")) != -1)
    switch (c)
      {
      case '6':
        ssm->cfg.address_ip6 = 1;
        break;

      case 'D':
        ssm->cfg.transport_udp = 1;
        break;

      case '?':
        switch (optopt)
          {
          default:
            if (isprint (optopt))
              fprintf (stderr, "SERVER: ERROR: Unknown "
                       "option `-%c'.\n", optopt);
            else
              fprintf (stderr, "SERVER: ERROR: Unknown "
                       "option character `\\x%x'.\n", optopt);
          }
        /* fall thru */
      case 'h':
      default:
        print_usage_and_exit ();
      }

  if (argc < (optind + 1))
    {
      fprintf (stderr, "SERVER: ERROR: Insufficient number of arguments!\n");
      print_usage_and_exit ();
    }

  if (sscanf (argv[optind], "%d", &v) == 1)
    port = (uint16_t) v;
  else
    {
      fprintf (stderr, "SERVER: ERROR: Invalid port (%s)!\n", argv[optind]);
      print_usage_and_exit ();
    }

  conn_pool_expand (SOCK_SERVER_MAX_TEST_CONN + 1);

  ssm->listen_fd = socket (ssm->cfg.address_ip6 ? AF_INET6 : AF_INET,
                           ssm->cfg.transport_udp ? SOCK_DGRAM : SOCK_STREAM,
                           0);

  if (ssm->listen_fd < 0)
    {
      errno_val = errno;
      perror ("ERROR in main()");
      fprintf (stderr, "SERVER: ERROR: socket() failed "
               "(errno = %d)!\n", errno_val);
      return ssm->listen_fd;
    }

  memset (&servaddr, 0, sizeof (servaddr));

  if (ssm->cfg.address_ip6)
    {
      struct sockaddr_in6 *server_addr = (struct sockaddr_in6 *) &servaddr;
      servaddr_size = sizeof (*server_addr);
      server_addr->sin6_family = AF_INET6;
      server_addr->sin6_addr = in6addr_any;
      server_addr->sin6_port = htons (port);
    }
  else
    {
      struct sockaddr_in *server_addr = (struct sockaddr_in *) &servaddr;
      servaddr_size = sizeof (*server_addr);
      server_addr->sin_family = AF_INET;
      server_addr->sin_addr.s_addr = htonl (INADDR_ANY);
      server_addr->sin_port = htons (port);
    }

  rv = bind (ssm->listen_fd, (struct sockaddr *) &servaddr, servaddr_size);
  if (rv < 0)
    {
      errno_val = errno;
      perror ("ERROR bind returned");
      fprintf (stderr, "SERVER: ERROR: bind failed (errno = %d)!\n",
               errno_val);
      return rv;
    }
  if (fcntl (ssm->listen_fd, F_SETFL, O_NONBLOCK) < 0)
    {
      errno_val = errno;
      perror ("ERROR fcntl returned");
      fprintf (stderr, "SERVER: ERROR: fcntl failed (errno = %d)!\n",
               errno_val);
      return rv;
    }
  rv = listen (ssm->listen_fd, 10);
  if (rv < 0)
    {
      errno_val = errno;
      perror ("ERROR in main()");
      fprintf (stderr, "SERVER: ERROR: listen failed "
               "(errno = %d)!\n", errno_val);
      return rv;
    }

  ssm->epfd = epoll_create (1);
  if (ssm->epfd < 0)
    {
      errno_val = errno;
      perror ("ERROR in main()");
      fprintf (stderr, "SERVER: ERROR: epoll_create failed (errno = %d)!\n",
               errno_val);
      return ssm->epfd;
    }

  ssm->listen_ev.events = EPOLLIN;
  ssm->listen_ev.data.u32 = ~0;

  rv = epoll_ctl (ssm->epfd, EPOLL_CTL_ADD, ssm->listen_fd, &ssm->listen_ev);
  if (rv < 0)
    {
      errno_val = errno;
      perror ("ERROR in main()");
      fprintf (stderr, "SERVER: ERROR: epoll_ctl failed "
               "(errno = %d)!\n", errno_val);
      return rv;
    }

  printf ("\nSERVER: Waiting for a client to connect on port %d...\n", port);

  while (1)
    {
      int num_ev;
      num_ev = epoll_wait (ssm->epfd, ssm->wait_events,
                           SOCK_SERVER_MAX_EPOLL_EVENTS, 60000);
      if (num_ev < 0)
        {
          perror ("epoll_wait()");
          fprintf (stderr, "\nSERVER: ERROR: epoll_wait() "
                   "failed -- aborting!\n");
          main_rv = -1;
          goto done;
        }
      if (num_ev == 0)
        {
          fprintf (stderr, "\nSERVER: epoll_wait() timeout!\n");
          continue;
        }
      for (i = 0; i < num_ev; i++)
        {
          conn = &ssm->conn_pool[ssm->wait_events[i].data.u32];
          if (ssm->wait_events[i].events & (EPOLLHUP | EPOLLRDHUP))
            {
              close (conn->fd);
              continue;
            }
          if (ssm->wait_events[i].data.u32 == ~0)
            {
              new_client ();
              continue;
            }
          else if (ssm->wait_events[i].data.u32 ==
                   SOCK_TEST_AF_UNIX_ACCEPT_DATA)
            {
              af_unix_echo ();
              continue;
            }
          client_fd = conn->fd;

          if (EPOLLIN & ssm->wait_events[i].events)
            {
            read_again:
              rx_bytes = sock_test_read (client_fd, conn->buf,
                                         conn->buf_size, &conn->stats);
              if (rx_bytes > 0)
                {
                  rx_cfg = (vcl_test_cfg_t *) conn->buf;
                  if (rx_cfg->magic == VCL_TEST_CFG_CTRL_MAGIC)
                    {
                      if (rx_cfg->verbose)
                        {
                          printf ("SERVER (fd %d): Received a cfg message!\n",
                                  client_fd);
                          vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
                        }

                      if (rx_bytes != sizeof (*rx_cfg))
                        {
                          printf ("SERVER (fd %d): Invalid cfg message "
                                  "size (%d)!\n  Should be %lu bytes.\n",
                                  client_fd, rx_bytes, sizeof (*rx_cfg));
                          conn->cfg.rxbuf_size = 0;
                          conn->cfg.num_writes = 0;
                          if (conn->cfg.verbose)
                            {
                              printf ("SERVER (fd %d): Replying to "
                                      "cfg message!\n", client_fd);
                              vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
                            }
                          sock_test_write (client_fd, (uint8_t *) & conn->cfg,
                                           sizeof (conn->cfg), NULL,
                                           conn->cfg.verbose);
                          continue;
                        }

                      switch (rx_cfg->test)
                        {
                        case VCL_TEST_TYPE_NONE:
                          sync_config_and_reply (conn, rx_cfg);
                          break;

                        case VCL_TEST_TYPE_ECHO:
                          if (socket_server_echo_af_unix_init (ssm))
                            goto done;
                          sync_config_and_reply (conn, rx_cfg);
                          break;

                        case VCL_TEST_TYPE_BI:
                        case VCL_TEST_TYPE_UNI:
                          stream_test_server_start_stop (conn, rx_cfg);
                          break;

                        case VCL_TEST_TYPE_EXIT:
                          printf ("SERVER: Have a great day, "
                                  "connection %d!\n", client_fd);
                          close (client_fd);
                          conn_pool_free (conn);
                          printf ("SERVER: Closed client fd %d\n", client_fd);
                          ssm->nfds--;
                          if (!ssm->nfds)
                            {
                              printf ("SERVER: All client connections "
                                      "closed.\n\nSERVER: "
                                      "May the force be with you!\n\n");
                              goto done;
                            }
                          break;

                        default:
                          fprintf (stderr,
                                   "SERVER: ERROR: Unknown test type!\n");
                          vcl_test_cfg_dump (rx_cfg, 0 /* is_client */ );
                          break;
                        }
                      continue;
                    }

                  else if ((conn->cfg.test == VCL_TEST_TYPE_UNI) ||
                           (conn->cfg.test == VCL_TEST_TYPE_BI))
                    {
                      stream_test_server (conn, rx_bytes);
                      if (ioctl (conn->fd, FIONREAD))
                        goto read_again;
                      continue;
                    }

                  else if (isascii (conn->buf[0]))
                    {
                      // If it looks vaguely like a string, make sure it's terminated
                      ((char *) conn->buf)[rx_bytes <
                                           conn->buf_size ? rx_bytes :
                                           conn->buf_size - 1] = 0;
                      printf ("SERVER (fd %d): RX (%d bytes) - '%s'\n",
                              conn->fd, rx_bytes, conn->buf);
                    }
                }
              else              // rx_bytes < 0
                {
                  if (errno == ECONNRESET)
                    {
                      printf ("\nSERVER: Connection reset by remote peer.\n"
                              "  Y'all have a great day now!\n\n");
                      break;
                    }
                  else
                    continue;
                }

              if (isascii (conn->buf[0]))
                {
                  /* If it looks vaguely like a string,
                   * make sure it's terminated
                   */
                  ((char *) conn->buf)[rx_bytes <
                                       conn->buf_size ? rx_bytes :
                                       conn->buf_size - 1] = 0;
                  if (xtra)
                    fprintf (stderr, "SERVER: ERROR: "
                             "FIFO not drained in previous test!\n"
                             "       extra chunks %u (0x%x)\n"
                             "        extra bytes %lu (0x%lx)\n",
                             xtra, xtra, xtra_bytes, xtra_bytes);

                  xtra = 0;
                  xtra_bytes = 0;

                  if (conn->cfg.verbose)
                    printf ("SERVER (fd %d): Echoing back\n", client_fd);

                  nbytes = strlen ((const char *) conn->buf) + 1;

                  tx_bytes = sock_test_write (client_fd, conn->buf,
                                              nbytes, &conn->stats,
                                              conn->cfg.verbose);
                  if (tx_bytes >= 0)
                    printf ("SERVER (fd %d): TX (%d bytes) - '%s'\n",
                            conn->fd, tx_bytes, conn->buf);
                }

              else              // Extraneous read data from non-echo tests???
                {
                  xtra++;
                  xtra_bytes += rx_bytes;
                }
            }
        }
    }

done:
  close (ssm->listen_fd);
  close (ssm->af_unix_listen_fd);
  unlink ((const char *) SOCK_TEST_AF_UNIX_FILENAME);

  if (ssm->conn_pool)
    free (ssm->conn_pool);

  return main_rv;
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */