awcs-proto.c

Serveez是一个服务器框架

/*
 * awcs-proto.c - aWCS protocol implementation
 *
 * Copyright (C) 2000, 2001 Stefan Jahn <[e-mail]>
 * Copyright (C) 1999 Martin Grabmueller <[e-mail]>
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 * 
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this package; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.  
 *
 * $Id: awcs-proto.c,v 1.34 2001/08/12 10:59:04 ela Exp $
 *
 */

#if HAVE_CONFIG_H
# include <config.h>
#endif

#if ENABLE_AWCS_PROTO

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#if HAVE_UNISTD_H
# include <unistd.h>
#endif

#ifdef __MINGW32__
# include <winsock2.h>
#endif

#ifndef __MINGW32__
# include <netinet/in.h>
#endif

#include "libserveez.h"
#include "awcs-proto.h"

/*
 * The aWCS server instance configuration.
 */
awcs_config_t awcs_config =
{
  NULL,           /* aWCS Master server */
  0,              /* Was Master server detected ? */
  NULL            /* aWCS clients user base hash */
};

/*
 * Definition of the configuration items delivered by the 
 * configuration language.
 */
svz_key_value_pair_t awcs_config_prototype [] =
{
  SVZ_REGISTER_END ()
};

/*
 * The aWCS server definition.
 */
svz_servertype_t awcs_server_definition =
{
  "aWCS server",         /* server description */
  "aWCS",                /* server prefix used in the config file "aWCS?" */
  NULL,                  /* global initialization */
  awcs_init,             /* server instance initialization */
  awcs_detect_proto,     /* protocol detection routine */
  awcs_connect_socket,   /* callback when detected */
  awcs_finalize,         /* server instance finalization */
  NULL,                  /* global finalization */
  NULL,                  /* client info */
  NULL,                  /* server info */
  NULL,                  /* server timer */
  NULL,                  /* handle request callback */
  &awcs_config,          /* the instance configuration */
  sizeof (awcs_config),  /* sizeof the instance configuration */
  awcs_config_prototype  /* configuration definitions  */
};

/*
 * These 3 (three) routines are for modifying the client hash key
 * processing. Because we are using unique IDs for identifying aWCS 
 * clients it is not necessary to have character strings here.
 */
static unsigned
awcs_hash_keylen (char *id)
{
  return 4;
}

static int 
awcs_hash_equals (char *id1, char *id2)
{
  return memcmp (id1, id2, 4);
}
 
static unsigned long 
awcs_hash_code (char *id)
{
  unsigned long code = SVZ_UINT32 (id);
  return code;
}

/*
 * Local aWCS server instance initialization routine.
 */
int
awcs_init (svz_server_t *server)
{
  awcs_config_t *cfg = server->cfg;

  /* initialize server instance */
  cfg->master = 0;
  cfg->clients = svz_hash_create (4);
  cfg->clients->code = awcs_hash_code;
  cfg->clients->keylen = awcs_hash_keylen;
  cfg->clients->equals = awcs_hash_equals;
  cfg->server = NULL;

  return 0;
}

/*
 * Local aWCS server instance finalizer.
 */
int
awcs_finalize (svz_server_t *server)
{
  awcs_config_t *cfg = server->cfg;
  
  svz_hash_destroy (cfg->clients);
  
  return 0;
}

/*
 * Gets called when a nslookup coserver has resolved a IP address
 * for socket SOCK to name and has been identified as an aWCS client.
 */
int
awcs_nslookup_done (char *host, int id, int version)
{
  awcs_config_t *cfg;
  svz_socket_t *sock = svz_sock_find (id, version);

  if (host && sock)
    {
      cfg = sock->cfg;

      if (!cfg->server)
	{
#if ENABLE_DEBUG
	  svz_log (LOG_DEBUG, "awcs: no master server (nslookup_done)\n");
#endif
	  return -1;
	}

#if ENABLE_DEBUG
      svz_log (LOG_DEBUG, "awcs: sending resolved ip to master\n");
#endif

      if (svz_sock_printf (cfg->server, AWCS_ID_FMT " %d " AWCS_ID_FMT " %s%c",
			   cfg->server->id,
			   STATUS_NSLOOKUP,
			   sock->id,
			   host, '\0'))
	{
	  svz_log (LOG_FATAL, "awcs: master write error\n");
	  svz_sock_schedule_for_shutdown (cfg->server);
	  cfg->server = NULL;
	  awcs_disconnect_clients (cfg);
	  return -1;
	}
    }

  return 0;
}

/*
 * Gets called when a ident coserver has resolved a IP address
 * for socket SOCK to name and has been identified as an aWCS client.
 */
int
awcs_ident_done (char *user, int id, int version)
{
  svz_socket_t *sock = svz_sock_find (id, version);
  awcs_config_t *cfg;

  if (user && sock)
    {
      cfg = sock->cfg;

      if (!cfg->server)
	{
#if ENABLE_DEBUG
	  svz_log (LOG_DEBUG, "awcs: no master server (ident_done)\n");
#endif
	  return -1;
	}

#if ENABLE_DEBUG
      svz_log (LOG_DEBUG, "awcs: sending identified client to master\n");
#endif

      if (svz_sock_printf (cfg->server, AWCS_ID_FMT " %d " AWCS_ID_FMT " %s%c",
			   cfg->server->id,
			   STATUS_IDENT,
			   sock->id,
			   user, '\0'))
	{
	  svz_log (LOG_FATAL, "awcs: master write error\n");
	  svz_sock_schedule_for_shutdown (cfg->server);
	  cfg->server = NULL;
	  awcs_disconnect_clients (cfg);
	  return -1;
	}
    }

  return 0;
}

/*
 * This is called when a valid aWCS client has been connected.
 * The routine reports this to the Master server and invokes
 * a reverse nslookup and a ident request.
 */
static int
awcs_status_connected (svz_socket_t *sock)
{
  unsigned short port;
  unsigned long addr;
  awcs_config_t *cfg = sock->cfg;

  if (!cfg->server)
    {
#if ENABLE_DEBUG
      svz_log (LOG_DEBUG, "awcs: no master server (status_connected)\n");
#endif
      return -1;
    }

  addr = sock->remote_addr;
  port = sock->remote_port;

#if ENABLE_DEBUG
  svz_log (LOG_DEBUG, "awcs: sending connect on socket id %d to master\n",
	   sock->id);
#endif

  if (svz_sock_printf (cfg->server, AWCS_ID_FMT " %d " AWCS_ID_FMT " %s:%u%c",
		       cfg->server->id,
		       STATUS_CONNECT,
		       sock->id,
		       svz_inet_ntoa (addr),
		       htons (port), '\0'))
    {
      svz_log (LOG_FATAL, "awcs: master write error\n");
      svz_sock_schedule_for_shutdown (cfg->server);
      cfg->server = NULL;
      awcs_disconnect_clients (cfg);
      return -1;
    }

  /*
   * Initiate a reverse nslookup and ident request for a real client.
   */
  if (sock != cfg->server)
    {
      svz_coserver_rdns (addr, awcs_nslookup_done, sock->id, sock->version);
      svz_coserver_ident (sock, awcs_ident_done, sock->id, sock->version);
    }

  return 0;
}

/*
 * Send a status message to the master server
 * telling it that client `client' has disconnected. `reason'
 * is an error code telling how the client got disconnected.
 */
static int
awcs_status_disconnected (svz_socket_t *sock, int reason)
{
  awcs_config_t *cfg = sock->cfg;

  if (!cfg->server)
    {
#if ENABLE_DEBUG
      svz_log (LOG_DEBUG, "awcs: no master server (status_disconnected)\n");
#endif
      return -1;
    }

#if ENABLE_DEBUG
  svz_log (LOG_DEBUG, "awcs: sending disconnect on socket %d to master\n",
	   sock->sock_desc);
#endif /* ENABLE_DEBUG */

  if (svz_sock_printf (cfg->server, AWCS_ID_FMT " %d " AWCS_ID_FMT " %d%c", 
		       cfg->server->id,
		       STATUS_DISCONNECT,
		       sock->id, 
		       reason, '\0'))
    {
      svz_log (LOG_FATAL, "awcs: master write error\n");
      svz_sock_schedule_for_shutdown (cfg->server);
      cfg->server = NULL;
      awcs_disconnect_clients (cfg);
      return -1;
    }
  
  return 0;
}

/*
 * Send a status message to the master server
 * telling it that client `client' has been kicked. `reason'
 * is an error code telling why the client got kicked.
 */
static int
awcs_status_kicked (svz_socket_t *sock, int reason)
{
  awcs_config_t *cfg = sock->cfg;
  
  if (!cfg->server)
    {
#if ENABLE_DEBUG
      svz_log (LOG_DEBUG, "awcs: no master server (status_kicked)\n");
#endif
      return -1;
    }

  if (svz_sock_printf (cfg->server, AWCS_ID_FMT " %d " AWCS_ID_FMT " %d%c",
		       cfg->server->id,
		       STATUS_KICK,
		       sock->id, 
		       reason, '\0'))
    {
      svz_log (LOG_FATAL, "awcs: master write error\n");
      svz_sock_schedule_for_shutdown (cfg->server);
      cfg->server = NULL;
      awcs_disconnect_clients (cfg);
      return -1;
    }

  return 0;
}

/*
 * Send a message to the master server indicating this server
 * is still alive.
 */
static int
awcs_status_alive (awcs_config_t *cfg)
{
  if (!cfg->server)
    {
#if ENABLE_DEBUG
      svz_log (LOG_DEBUG, "awcs: no master server (status_alive)\n");
#endif /* ENABLE_DEBUG */
      return -1;
    }

  if (svz_sock_printf (cfg->server, AWCS_ID_FMT " %d 42%c",
		       cfg->server->id,
		       STATUS_ALIVE, '\0'))
    {
      svz_log (LOG_FATAL, "awcs: master write error\n");
      svz_sock_schedule_for_shutdown (cfg->server);
      cfg->server = NULL;
      awcs_disconnect_clients (cfg);
      return -1;
    }
  
  return 0;
}

static int
awcs_status_notify (awcs_config_t *cfg) 
{
  if (!cfg->server)
    {
#if ENABLE_DEBUG
      svz_log (LOG_DEBUG, "awcs: no master server (status_notify)\n");
#endif /* ENABLE_DEBUG */
      return -1;
    }

  if (svz_sock_printf (cfg->server, AWCS_ID_FMT " %d 42%c",
		       cfg->server->id,
		       STATUS_NOTIFY, '\0'))
    {
      svz_log (LOG_FATAL, "awcs: master write error\n");
      svz_sock_schedule_for_shutdown (cfg->server);
      cfg->server = NULL;
      awcs_disconnect_clients (cfg);
      return -1;
    }

  return 0;
}

/*
 * Broadcast message `cmd' to all connected aWCS clients.
 */
static int
awcs_process_broadcast (awcs_config_t *cfg, char *cmd, int cmd_len)
{
  svz_socket_t **sock;
  int n;
  
#if ENABLE_DEBUG
  svz_log (LOG_DEBUG, "awcs: broadcasting\n");
#endif /* ENABLE_DEBUG */

  if ((sock = (svz_socket_t **) svz_hash_values (cfg->clients)) != NULL)
    {
      for (n = 0; n < svz_hash_size (cfg->clients); n++)
	{
	  if (svz_sock_write (sock[n], cmd, cmd_len))
	    {
	      svz_sock_schedule_for_shutdown (sock[n]);
	    }
	}
      svz_hash_xfree (sock);
    }
  return 0;
}

/*
 * This macro parse an aWCS id at the given memory location @var{ptr}. The
 * result will be stored in @var{id} and @var{ptr} points to the following
 * non numerical byte afterwards.
 */
#define awcs_process_id(id, ptr)           \
  (id) = 0;                                \
  while (*(ptr) >= '0' && *(ptr) <= '9') { \
    (id) *= 10;                            \
    (id) += *(ptr) - '0';                  \
    (ptr)++; }                             \
  if (*(ptr) == ',') (ptr)++

/*
 * Send message @var{cmd} to all clients in the client list at the start 
 * of @var{cmd}.
 */
static int
awcs_process_multicast (awcs_config_t *cfg, char *cmd, int cmd_len)
{
  char *msg;
  int address;
  svz_socket_t *sock;

  /* Parse the actual message first. */
  msg = cmd;
  while (*msg++ != ' ');
  cmd_len -= (msg - cmd);

  /* Go through the client list. */