sysdep.c

支持网络和单机的麻将游戏

/* $Header: /home/jcb/newmj/RCS/sysdep.c,v 11.16 2003/10/08 19:35:42 jcb Rel $
 * sysdep.c
 * By intention, this file contains all functions that might need
 * fiddling with to cope with different variants of Unix.
 * In particular, all the networking code is in here.
 * Some parts of the other code assume POSIXish functions for file
 * descriptors and the like; this file is responsible for providing them
 * if they're not native. All such cases that occurred to me as I was
 * writing them can be found by searching for sysdep.c in the other
 * files.
 */
/****************** COPYRIGHT STATEMENT **********************
 * This file is Copyright (c) 2000 by J. C. Bradfield.       *
 * Distribution and use is governed by the LICENCE file that *
 * accompanies this file.                                    *
 * The moral rights of the author are asserted.              *
 *                                                           *
 ***************** DISCLAIMER OF WARRANTY ********************
 * This code is not warranted fit for any purpose. See the   *
 * LICENCE file for further information.                     *
 *                                                           *
 *************************************************************/

static const char rcs_id[] = "$Header: /home/jcb/newmj/RCS/sysdep.c,v 11.16 2003/10/08 19:35:42 jcb Rel $";

#include "sysdep.h"
#include <string.h>
#include <fcntl.h>

#ifndef WIN32
#include <sys/socket.h>
#include <netinet/in.h>
/* needed for HP-UX 11 with _XOPEN_SOURCE_EXTENDED */
#include <arpa/inet.h>
#include <sys/un.h>
/* this is modern, I think. */
#include <netdb.h>
#include <pwd.h>
#endif /* not WIN32 */

#include <stdlib.h>
#include <stdarg.h>
#include <time.h>
#include <signal.h>

#ifdef WIN32
#include <io.h>
#include <fcntl.h>
#endif

/* warn: = fprintf(stderr,...), with automatic new line */
/* log_msg is a generalized version with a syslog like warning
   level. Currently only two levels are defined by the
   LogLevel enum, LogWarning and LogInfo. */


int (*log_msg_hook)(LogLevel l,char *);

static char *log_prefixes[] = { "" , "-I- ", "+W+ " };

/* internal function */
static int vlog_msg(LogLevel l, char *format,va_list args) {
  char buf[1024];
  int ret;
  int n;

  strcpy(buf,log_prefixes[l]);
  n = strlen(log_prefixes[l]);
  /* My Windows/Mingw installation doesn't have vsnprintf!
     Oh well, we'll just hope it doesn't overflow. */
#ifdef WIN32
  ret = vsprintf(buf+n,format,args);
#else
  /* reserve 1 char for extra '\n' */
  ret = vsnprintf(buf+n,sizeof(buf)-n-1,format,args);
#endif
  buf[1023] = 0;
  n = strlen(buf);
  /* do quick check for terminators */
#ifdef WIN32
  if ( buf[n-2] == '\r' ) {
    /* OK */
    ;
  } else if ( buf[n-1] == '\n' ) {
    /* already have unix terminator */
    buf[n-1] = '\r' ; buf[n] = '\n' ; buf[n+1] = 0 ;
  } else {
    /* no terminator */
    strcat(buf,"\r\n");
  }
#else
  if ( buf[n-1] != '\n' ) strcat(buf,"\n");
#endif
  /* call the hook */
  if ( log_msg_hook == NULL || log_msg_hook(l,buf) == 0 ) {
    fprintf(stderr,"%s",buf);
  }
  return ret;
}

int log_msg(LogLevel l,char *format,...) {
  va_list args;
  va_start(args,format);
  return vlog_msg(l,format,args);
}

int warn(char *format,...) {
  va_list args;
  va_start(args,format);
  return vlog_msg(LogWarning,format,args);
}

int info(char *format,...) {
  va_list args;
  va_start(args,format);
  return vlog_msg(LogInfo,format,args);
}

/* ignore the SIGPIPE signal. Return 0 on success, -1 on error */
int ignore_sigpipe(void) {
#ifdef WIN32
  return 0;
#else
  /* this is just posix at present */
  struct sigaction act;

  act.sa_handler = SIG_IGN;
  sigemptyset(&act.sa_mask);
  act.sa_flags = 0;
  return sigaction(SIGPIPE,&act,NULL);
#endif /* WIN32 */
}

/* functions to be applied by the socket routines */
static void *(*skt_open_transform)(SOCKET) = NULL;
static int (*skt_closer)(void *) = NULL;
static int (*skt_reader)(void *, void *, size_t) = NULL;
static int (*skt_writer)(void *, const void *,size_t) = NULL;
static int sockets_initialized = 0;

#ifdef WIN32
static void shutdown_sockets(void) {
  WSACleanup();
  /* I don't care what it returns */
}
#endif /* WIN32 */

/* initialize sockets */
int initialize_sockets(void *(*open_transform)(SOCKET),
		       int (*closer)(void *),
		       int (*reader)(void *, void *, size_t),
		       int (*writer)(void *, const void *,size_t)) {
  skt_open_transform = open_transform;
  skt_closer = closer;
  skt_reader = reader;
  skt_writer = writer;
#ifdef WIN32

  if ( ! sockets_initialized ) {
    WORD version;
    WSADATA data;
    int err;
    
    version = MAKEWORD( 2, 2 );
    
    err = WSAStartup( version, &data );
    if (err != 0) {
      return 0;
    }
    if ((LOBYTE( data.wVersion ) != 2) || (HIBYTE( data.wVersion ) != 2)) {
      WSACleanup();
      return 0;
    }
    if ( atexit(shutdown_sockets) != 0 ) {
      warn("couldn't register socket shutdown routine");
    }
  }
#endif /* WIN32 */

  sockets_initialized = 1;
  return 1;
}

/* this function takes a string and parses it as an address.
   It returns 0 for an Internet address, 1 for a Unix address.
   For Internet addresses, the host name and port are placed
   in the given variables (the string had better be long enough);
   for Unix, the file name is copied to the given variable.
*/
static int parse_address(const char *address,
			 char *ret_host,
			 unsigned short *ret_port,
			 char *ret_file) {
  if ( strchr(address,':') ) {
    /* grrr */
    if ( address[0] == ':' ) {
      strcpy(ret_host,"localhost");
      sscanf(address,":%hu",ret_port);
    } else {
      sscanf(address,"%[^:]:%hu",ret_host,ret_port);
    }
    return 0;
  } else {
    if ( ret_file) strcpy(ret_file,address);
    return 1;
  }
}

/* set_up_listening_socket:
   Set up a socket listening on the given address.
   Return its fd.
*/
SOCKET set_up_listening_socket(const char *address) {
  SOCKET sfd;
  struct protoent *prstruc = NULL;
  struct sockaddr_in inaddr;
#ifndef WIN32
  struct sockaddr_un unaddr;
#endif
  int unixsockets;
  unsigned short port;
  char name[256];
  int sockopt;

  if ( ! sockets_initialized ) initialize_sockets(NULL,NULL,NULL,NULL);

  unixsockets = 
#ifdef WIN32
    parse_address(address,name,&port,NULL);
#else
    parse_address(address,name,&port,unaddr.sun_path);
#endif /* WIN32 */

#ifdef WIN32
  if ( unixsockets ) {
    warn("unix sockets not available on Windows");
    return INVALID_SOCKET;
  }
#endif /* WINDOWS */

  if ( !unixsockets ) {
    prstruc = getprotobyname("tcp");
    if ( prstruc == NULL ) {
      perror("getprotobyname failed");
      return INVALID_SOCKET;
    }
  }
  sfd = socket(unixsockets ? AF_UNIX : AF_INET,
	       SOCK_STREAM,
	       unixsockets ? 0 : prstruc->p_proto);
  if ( sfd == INVALID_SOCKET ) {
    perror("socket failed");
    return INVALID_SOCKET;
  }

  sockopt=1;
  setsockopt(sfd,SOL_SOCKET,SO_REUSEADDR,(void *)&sockopt,sizeof(int));

#ifndef WIN32
  if ( unixsockets ) {
    unaddr.sun_family = AF_UNIX;
    unlink(unaddr.sun_path); /* need to check success FIXME */
    if ( bind(sfd,(struct sockaddr *)&unaddr,sizeof(struct sockaddr_un)) < 0 ) {
      perror("bind failed");
      return INVALID_SOCKET;
    }
  } else {
#else
  if ( 1 ) {
#endif /* WIN32 */
    inaddr.sin_family = AF_INET;
    inaddr.sin_port = htons(port);
    inaddr.sin_addr.s_addr = INADDR_ANY;
    if ( bind(sfd,(struct sockaddr *)&inaddr,sizeof(struct sockaddr_in)) < 0 ) {
      perror("bind failed");
      return INVALID_SOCKET;
    }
  }

  if ( listen(sfd,5) < 0 ) {
    perror("listen failed");
    return INVALID_SOCKET;
  }
  
  if ( skt_open_transform ) {
    return (SOCKET) skt_open_transform(sfd);
  } else {
    return sfd;
  }
}
  
  

/* accept_new_connection:
   A connection has arrived on the socket fd.
   Accept the connection, and return the new fd,
   or INVALID_SOCKET on error.
*/

SOCKET accept_new_connection(SOCKET fd) {
  SOCKET newfd;
  struct sockaddr saddr;
  struct linger l = { 1, 1000 } ; /* linger on close for 10 seconds */
  socklen_t saddrlen = sizeof(saddr);

  if ( ! sockets_initialized ) initialize_sockets(NULL,NULL,NULL,NULL);

  newfd = accept(fd,&saddr,&saddrlen);
  if ( newfd == INVALID_SOCKET ) { perror("accept failed"); }
  /* we should make sure that data is sent when this socket is closed */
  if ( setsockopt(newfd,SOL_SOCKET,SO_LINGER,(void *)&l,sizeof(l)) < 0 ) {
    warn("setsockopt failed");
  }
  if ( skt_open_transform ) {
    return (SOCKET) skt_open_transform(newfd);
  } else {
    return newfd;
  }
}

/* connect_to_host:
   Establish a connection to the given address.
   Return the file descriptor or INVALID_SOCKET on error.
   If unixsockets, only the port number is used in making the name
   The returned socket is marked close-on-exec .
*/

SOCKET connect_to_host(const char *address) {
  SOCKET fd;
  struct sockaddr_in inaddr;
#ifndef WIN32
  struct sockaddr_un unaddr;
#endif
  char name[512];
  int unixsockets;
  unsigned short port;
  struct hostent *hent = NULL;
  struct protoent *prstruc = NULL;

  if ( ! sockets_initialized ) initialize_sockets(NULL,NULL,NULL,NULL);

#ifdef WIN32
  unixsockets = parse_address(address,name,&port,NULL);
  if ( unixsockets ) {
    warn("Unix sockets not supported on Windows");
    return INVALID_SOCKET;
  }
#else
  unixsockets = parse_address(address,name,&port,unaddr.sun_path);
#endif /* WIN32 */

  if ( !unixsockets ) {
    hent = gethostbyname(name);
    
    if ( ! hent ) {
      perror("connect_to_host: gethostbyname failed");
      return INVALID_SOCKET;
    }
    
    prstruc = getprotobyname("tcp");
    if ( prstruc == NULL ) {
      perror("connect_to_host: getprotobyname failed");
      return INVALID_SOCKET;
    }
  }

  fd = socket(unixsockets ? AF_UNIX : AF_INET,
	      SOCK_STREAM,
	      unixsockets ? 0 : prstruc->p_proto);
  if ( fd == INVALID_SOCKET ) {
    perror("connect_to_host: socket failed");
    return INVALID_SOCKET;
  }

#ifndef WIN32
  if ( unixsockets ) {
    unaddr.sun_family = AF_UNIX;
    if ( connect(fd,(struct sockaddr *)&unaddr,sizeof(struct sockaddr_un)) < 0 ) {
      perror("connect_to_host: connect failed");
      return INVALID_SOCKET;
    }
  } else {
#else
  if ( 1 ) {
#endif /* WIN32 */
    inaddr.sin_family = AF_INET;
    inaddr.sin_port = htons(port);
    inaddr.sin_addr = *((struct in_addr *)hent->h_addr);
    if ( connect(fd,(struct sockaddr *)&inaddr,sizeof(struct sockaddr_in)) < 0 ) {
      perror("connect_to_host: connect failed");
      return INVALID_SOCKET;
    }
  }
  
#ifndef WIN32
  /* mark close on exec */
  fcntl(fd,F_SETFD,1);
#endif /* WIN32 */

  if ( skt_open_transform ) {
    return (SOCKET) skt_open_transform(fd);
  } else {
    return fd;
  }
}

/* close a network connection */
int close_socket(SOCKET s) {
  if ( skt_closer ) {
    return skt_closer((void *)s);