/*
 * Copyright (c) 2017-2018 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.
 */

#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 <sys/stat.h>
#include <fcntl.h>
#include <vcl/vcl_test.h>
#include <sys/epoll.h>
#include <vppinfra/mem.h>
#include <pthread.h>

typedef struct
{
  uint8_t is_alloc;
  int fd;
  uint8_t *buf;
  uint32_t buf_size;
  sock_test_cfg_t cfg;
  sock_test_stats_t stats;
  vppcom_endpt_t endpt;
  uint8_t ip[16];
} vcl_test_server_conn_t;

typedef struct
{
  uint16_t port;
  uint32_t address_ip6;
  u8 proto;
  u8 workers;
  vppcom_endpt_t endpt;
} vcl_test_server_cfg_t;

#define SOCK_SERVER_MAX_TEST_CONN  16
#define SOCK_SERVER_MAX_EPOLL_EVENTS 16

typedef struct
{
  uint32_t wrk_index;
  int listen_fd;
  int epfd;
  struct epoll_event wait_events[SOCK_SERVER_MAX_EPOLL_EVENTS];
  size_t conn_pool_size;
  vcl_test_server_conn_t *conn_pool;
  int nfds;
  pthread_t thread_handle;
} vcl_test_server_worker_t;

typedef struct
{
  vcl_test_server_cfg_t cfg;
  vcl_test_server_worker_t *workers;

  struct sockaddr_storage servaddr;
  volatile int worker_fails;
  volatile int active_workers;
} vcl_test_server_main_t;

static __thread int __wrk_index = 0;

static vcl_test_server_main_t sock_server_main;

#define vtfail(_fn, _rv)						\
{									\
  errno = -_rv;								\
  perror ("ERROR when calling " _fn);					\
  fprintf (stderr, "\nSERVER ERROR: " _fn " failed (errno = %d)!\n", -_rv);\
  exit (1);								\
}

#define vterr(_fn, _rv)							\
{									\
  errno = -_rv;								\
  fprintf (stderr, "\nSERVER ERROR: " _fn " failed (errno = %d)!\n", -_rv);\
}

#define vtwrn(_fmt, _args...)						\
  fprintf (stderr, "\nSERVER ERROR: " _fmt "\n", ##_args)		\

#define vtinf(_fmt, _args...)						\
  fprintf (stdout, "\nvts<w%u>: " _fmt "\n", __wrk_index, ##_args)	\

static inline void
conn_pool_expand (vcl_test_server_worker_t * wrk, size_t expand_size)
{
  vcl_test_server_conn_t *conn_pool;
  size_t new_size = wrk->conn_pool_size + expand_size;
  int i;

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

      wrk->conn_pool = conn_pool;
      wrk->conn_pool_size = new_size;
    }
  else
    {
      vterr ("conn_pool_expand()", -errno);
    }
}

static inline vcl_test_server_conn_t *
conn_pool_alloc (vcl_test_server_worker_t * wrk)
{
  int i;

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

  return 0;
}

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

static inline void
sync_config_and_reply (vcl_test_server_conn_t * conn,
		       sock_test_cfg_t * rx_cfg)
{
  conn->cfg = *rx_cfg;
  sock_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)
    {
      vtinf ("(fd %d): Replying to cfg message!\n", conn->fd);
      sock_test_cfg_dump (&conn->cfg, 0 /* is_client */ );
    }
  (void) vcl_test_write (conn->fd, (uint8_t *) & conn->cfg,
			 sizeof (conn->cfg), NULL, conn->cfg.verbose);
}

static void
stream_test_server_start_stop (vcl_test_server_worker_t * wrk,
			       vcl_test_server_conn_t * conn,
			       sock_test_cfg_t * rx_cfg)
{
  int client_fd = conn->fd;
  sock_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 < wrk->conn_pool_size; i++)
	{
	  vcl_test_server_conn_t *tc = &wrk->conn_pool[i];

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

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

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

      sock_test_stats_dump ("SERVER RESULTS", &conn->stats, 1 /* show_rx */ ,
			    (test == SOCK_TEST_TYPE_BI) /* show_tx */ ,
			    conn->cfg.verbose);
      sock_test_cfg_dump (&conn->cfg, 0 /* is_client */ );
      if (conn->cfg.verbose)
	{
	  printf ("  sock server main\n"
		  SOCK_TEST_SEPARATOR_STRING
		  "       buf:  %p\n"
		  "  buf size:  %u (0x%08x)\n"
		  SOCK_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 == SOCK_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 == SOCK_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 (vcl_test_server_conn_t * conn, int rx_bytes)
{
  int client_fd = conn->fd;
  sock_test_t test = conn->cfg.test;

  if (test == SOCK_TEST_TYPE_BI)
    (void) vcl_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 void
vcl_test_server_echo (vcl_test_server_conn_t * conn, int rx_bytes)
{
  int tx_bytes, nbytes, pos;

  /* If it looks vaguely like a string,
   * make sure it's terminated
   */
  pos = rx_bytes < conn->buf_size ? rx_bytes : conn->buf_size - 1;
  ((char *) conn->buf)[pos] = 0;
  vtinf ("(fd %d): RX (%d bytes) - '%s'", conn->fd, rx_bytes, conn->buf);

  if (conn->cfg.verbose)
    vtinf ("(fd %d): Echoing back", conn->fd);

  nbytes = strlen ((const char *) conn->buf) + 1;
  tx_bytes = vcl_test_write (conn->fd, conn->buf, nbytes, &conn->stats,
			     conn->cfg.verbose);
  if (tx_bytes >= 0)
    vtinf ("(fd %d): TX (%d bytes) - '%s'", conn->fd, tx_bytes, conn->buf);
}

static inline void
vcl_test_server_new_client (vcl_test_server_worker_t * wrk)
{
  int client_fd;
  vcl_test_server_conn_t *conn;

  conn = conn_pool_alloc (wrk);
  if (!conn)
    {
      vtwrn ("No free connections!");
      return;
    }

  client_fd = vppcom_session_accept (wrk->listen_fd, &conn->endpt, 0);
  if (client_fd < 0)
    {
      vterr ("vppcom_session_accept()", client_fd);
      return;
    }

  vtinf ("Got a connection -- fd = %d (0x%08x)!", client_fd, client_fd);

  conn->fd = client_fd;

  {
    struct epoll_event ev;
    int rv;

    ev.events = EPOLLIN;
    ev.data.u64 = conn - wrk->conn_pool;
    rv = vppcom_epoll_ctl (wrk->epfd, EPOLL_CTL_ADD, client_fd, &ev);
    if (rv < 0)
      {
	vterr ("vppcom_epoll_ctl()", rv);
	return;
      }
    wrk->nfds++;
  }
}

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"
	   "  -w <num>         Number of workers\n"
	   "  -u               Use UDP transport layer\n");
  exit (1);
}

static void
vcl_test_init_endpoint_addr (vcl_test_server_main_t * ssm)
{
  struct sockaddr_storage *servaddr = &ssm->servaddr;
  memset (servaddr, 0, sizeof (*servaddr));

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

  if (ssm->cfg.address_ip6)
    {
      struct sockaddr_in6 *server_addr = (struct sockaddr_in6 *) servaddr;
      ssm->cfg.endpt.is_ip4 = 0;
      ssm->cfg.endpt.ip = (uint8_t *) & server_addr->sin6_addr;
      ssm->cfg.endpt.port = (uint16_t) server_addr->sin6_port;
    }
  else
    {
      struct sockaddr_in *server_addr = (struct sockaddr_in *) servaddr;
      ssm->cfg.endpt.is_ip4 = 1;
      ssm->cfg.endpt.ip = (uint8_t *) & server_addr->sin_addr;
      ssm->cfg.endpt.port = (uint16_t) server_addr->sin_port;
    }
}

void
vcl_test_server_process_opts (vcl_test_server_main_t * ssm, int argc,
			      char **argv)
{
  int v, c;

  ssm->cfg.proto = VPPCOM_PROTO_TCP;

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

      case 'D':
	ssm->cfg.proto = VPPCOM_PROTO_UDP;
	break;

      case 'w':
	v = atoi (optarg);
	if (v > 1)
	  ssm->cfg.workers = v;
	else
	  vtwrn ("Invalid number of workers %d", v);
	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)
    ssm->cfg.port = (uint16_t) v;
  else
    {
      fprintf (stderr, "SERVER: ERROR: Invalid port (%s)!\n", argv[optind]);
      print_usage_and_exit ();
    }

  vcl_test_init_endpoint_addr (ssm);
}

int
vcl_test_server_handle_cfg (vcl_test_server_worker_t * wrk,
			    sock_test_cfg_t * rx_cfg,
			    vcl_test_server_conn_t * conn, int rx_bytes)
{
  if (rx_cfg->verbose)
    {
      vtinf ("(fd %d): Received a cfg msg!", conn->fd);
      sock_test_cfg_dump (rx_cfg, 0 /* is_client */ );
    }

  if (rx_bytes != sizeof (*rx_cfg))
    {
      vtinf ("(fd %d): Invalid cfg msg size %d expected %lu!", conn->fd,
	     rx_bytes, sizeof (*rx_cfg));
      conn->cfg.rxbuf_size = 0;
      conn->cfg.num_writes = 0;
      if (conn->cfg.verbose)
	{
	  vtinf ("(fd %d): Replying to cfg msg", conn->fd);
	  sock_test_cfg_dump (rx_cfg, 0 /* is_client */ );
	}
      vcl_test_write (conn->fd, (uint8_t *) & conn->cfg,
		      sizeof (conn->cfg), NULL, conn->cfg.verbose);
      return -1;
    }

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

    case SOCK_TEST_TYPE_BI:
    case SOCK_TEST_TYPE_UNI:
      stream_test_server_start_stop (wrk, conn, rx_cfg);
      break;

    case SOCK_TEST_TYPE_EXIT:
      vtinf ("Have a great day conn %d (closing)!", conn->fd);
      vppcom_session_close (conn->fd);
      conn_pool_free (conn);
      wrk->nfds--;
      break;

    default:
      vtwrn ("Unknown test type %d", rx_cfg->test);
      sock_test_cfg_dump (rx_cfg, 0 /* is_client */ );
      break;
    }

  return 0;
}

static void
vcl_test_server_worker_init (vcl_test_server_worker_t * wrk)
{
  vcl_test_server_main_t *ssm = &sock_server_main;
  struct epoll_event listen_ev;
  int rv;

  __wrk_index = wrk->wrk_index;

  vtinf ("Initializing worker ...");

  conn_pool_expand (wrk, SOCK_SERVER_MAX_TEST_CONN + 1);
  if (wrk->wrk_index)
    vppcom_worker_register ();

  wrk->listen_fd = vppcom_session_create (ssm->cfg.proto,
					  0 /* is_nonblocking */ );
  if (wrk->listen_fd < 0)
    vtfail ("vppcom_session_create()", wrk->listen_fd);

  rv = vppcom_session_bind (wrk->listen_fd, &ssm->cfg.endpt);
  if (rv < 0)
    vtfail ("vppcom_session_bind()", rv);

  if (!(ssm->cfg.proto == VPPCOM_PROTO_UDP))
    {
      rv = vppcom_session_listen (wrk->listen_fd, 10);
      if (rv < 0)
	vtfail ("vppcom_session_listen()", rv);
    }

  wrk->epfd = vppcom_epoll_create ();
  if (wrk->epfd < 0)
    vtfail ("vppcom_epoll_create()", wrk->epfd);

  listen_ev.events = EPOLLIN;
  listen_ev.data.u32 = ~0;
  rv = vppcom_epoll_ctl (wrk->epfd, EPOLL_CTL_ADD, wrk->listen_fd,
			 &listen_ev);
  if (rv < 0)
    vtfail ("vppcom_epoll_ctl", rv);

  vtinf ("Waiting for a client to connect on port %d ...", ssm->cfg.port);
}

static void *
vcl_test_server_worker_loop (void *arg)
{
  vcl_test_server_main_t *ssm = &sock_server_main;
  vcl_test_server_worker_t *wrk = arg;
  vcl_test_server_conn_t *conn;
  int i, rx_bytes, num_ev;
  sock_test_cfg_t *rx_cfg;

  if (wrk->wrk_index)
    vcl_test_server_worker_init (wrk);

  while (1)
    {
      num_ev = vppcom_epoll_wait (wrk->epfd, wrk->wait_events,
				  SOCK_SERVER_MAX_EPOLL_EVENTS, 60000.0);
      if (num_ev < 0)
	{
	  vterr ("vppcom_epoll_wait()", num_ev);
	  goto fail;
	}
      else if (num_ev == 0)
	{
	  vtinf ("vppcom_epoll_wait() timeout!");
	  continue;
	}
      for (i = 0; i < num_ev; i++)
	{
	  conn = &wrk->conn_pool[wrk->wait_events[i].data.u32];
	  if (wrk->wait_events[i].events & (EPOLLHUP | EPOLLRDHUP))
	    {
	      vppcom_session_close (conn->fd);
	      continue;
	    }
	  if (wrk->wait_events[i].data.u32 == ~0)
	    {
	      vcl_test_server_new_client (wrk);
	      continue;
	    }

	  if (EPOLLIN & wrk->wait_events[i].events)
	    {
	      rx_bytes = vcl_test_read (conn->fd, conn->buf,
					conn->buf_size, &conn->stats);

	      if (rx_bytes <= 0)
		{
		  if (errno == ECONNRESET)
		    {
		      vtinf ("Connection reset by remote peer.\n");
		      goto fail;
		    }
		  else
		    continue;
		}

	      rx_cfg = (sock_test_cfg_t *) conn->buf;
	      if (rx_cfg->magic == SOCK_TEST_CFG_CTRL_MAGIC)
		{
		  vcl_test_server_handle_cfg (wrk, rx_cfg, conn, rx_bytes);
		  if (!wrk->nfds)
		    {
		      vtinf ("All client connections closed\n");
		      vtinf ("May the force be with you!\n");
		      goto done;
		    }
		  continue;
		}
	      else if ((conn->cfg.test == SOCK_TEST_TYPE_UNI)
		       || (conn->cfg.test == SOCK_TEST_TYPE_BI))
		{
		  stream_test_server (conn, rx_bytes);
		  continue;
		}
	      else if (isascii (conn->buf[0]))
		{
		  vcl_test_server_echo (conn, rx_bytes);
		}
	      else
		{
		  vtwrn ("FIFO not drained! extra bytes %d", rx_bytes);
		}
	    }
	  else
	    {
	      vtwrn ("Unhandled event");
	      goto fail;
	    }
	}
    }

fail:
  ssm->worker_fails -= 1;

done:
  vppcom_session_close (wrk->listen_fd);
  if (wrk->conn_pool)
    free (wrk->conn_pool);
  ssm->active_workers -= 1;
  return 0;
}

int
main (int argc, char **argv)
{
  vcl_test_server_main_t *ssm = &sock_server_main;
  int rv, i;

  clib_mem_init_thread_safe (0, 64 << 20);
  ssm->cfg.port = SOCK_TEST_SERVER_PORT;
  ssm->cfg.workers = 1;
  ssm->active_workers = 1;
  vcl_test_server_process_opts (ssm, argc, argv);

  rv = vppcom_app_create ("vcl_test_server");
  if (rv)
    vtfail ("vppcom_app_create()", rv);

  ssm->workers = calloc (ssm->cfg.workers, sizeof (*ssm->workers));
  vcl_test_server_worker_init (&ssm->workers[0]);
  for (i = 1; i < ssm->cfg.workers; i++)
    {
      ssm->workers[i].wrk_index = i;
      rv = pthread_create (&ssm->workers[i].thread_handle, NULL,
			   vcl_test_server_worker_loop,
			   (void *) &ssm->workers[i]);
    }
  vcl_test_server_worker_loop (&ssm->workers[0]);

  while (ssm->active_workers > 0)
    ;

  vppcom_app_destroy ();
  free (ssm->workers);

  return ssm->worker_fails;
}

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