1  /********************************************************************
  2  * Description: tcp_opts.cc
  3  *
  4  *   Derived from a work by Fred Proctor & Will Shackleford
  5  *
  6  * Author:
  7  * License: LGPL Version 2
  8  * System: Linux
  9  *    
 10  * Copyright (c) 2004 All rights reserved.
 11  *
 12  * Last change: 
 13  ********************************************************************/
 14  
 15  #include "tcp_opts.hh"
 16  #include "rcs_print.hh"		/* rcs_print_error() */
 17  
 18  #include <errno.h>		// errno
 19  #include <string.h>		// strerror
 20  #include <netinet/tcp.h>	// TCP_NODELAY
 21  #include <netinet/in.h>		// TCP_NODELAY
 22  #include <sys/fcntl.h>		// fcntl, O_NONBLOCK
 23  
 24  #include <sys/types.h>
 25  #include <sys/socket.h>
 26  
 27  int set_tcp_socket_options(int socket_fd)
 28  {
 29      if (socket_fd <= 0) {
 30  	return -1;
 31      }
 32      int optval = 1;
 33  #ifdef TCP_NODELAY
 34      if (setsockopt(socket_fd, IPPROTO_TCP, TCP_NODELAY,
 35  	    (char *) &optval, sizeof(optval)) < 0) {
 36  	rcs_print_error(" Can`t set a socket option.\n");
 37  	rcs_print_error("errno = %d = %s\n", errno, strerror(errno));
 38  	return -1;
 39      }
 40  #endif
 41  
 42      optval = 1;
 43  
 44      if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR,
 45  	    (char *) &optval, sizeof(optval)) < 0) {
 46  	rcs_print_error(" Can`t set a socket option.\n");
 47  	rcs_print_error("errno = %d = %s\n", errno, strerror(errno));
 48  	return -1;
 49      }
 50      struct linger linger_opt;
 51      linger_opt.l_onoff = 0;
 52      linger_opt.l_linger = 0;
 53      if (setsockopt(socket_fd, SOL_SOCKET, SO_LINGER,
 54  	    (char *) &linger_opt, sizeof(linger_opt)) < 0) {
 55  	rcs_print_error(" Can`t set a socket option.\n");
 56  	rcs_print_error("errno = %d = %s\n", errno, strerror(errno));
 57  	return -1;
 58      }
 59      return 0;
 60  }
 61  
 62  int make_tcp_socket_nonblocking(int socket_fd)
 63  {
 64  #ifdef O_NONBLOCK
 65      if (-1 == fcntl(socket_fd, F_SETFL, O_NONBLOCK)) {
 66  	rcs_print_error("Couldn's set flag for non-blocking on socket.\n");
 67  	return -1;
 68      }
 69  #else
 70  #ifdef O_NDELAY
 71      if (-1 == fcntl(socket_fd, F_SETFL, O_NDELAY)) {
 72  	rcs_print_error("Couldn's set flag for no delay on socket.\n");
 73  	return -1;
 74      }
 75  #endif
 76  #endif
 77      return (0);
 78  }
 79  
 80  int make_tcp_socket_blocking(int socket_fd)
 81  {
 82  #if defined(O_NONBLOCK) || defined(O_NDELAY)
 83      int val = fcntl(socket_fd, F_GETFL, 0);
 84      if (val < 0) {
 85  	rcs_print_error("fcntl error %d %s\n", errno, strerror(errno));
 86  	return -1;
 87      }
 88  #ifdef O_NONBLOCK
 89      val &= ~O_NONBLOCK;
 90  #endif
 91  #ifdef O_NDELAY
 92      val &= ~O_NDELAY;
 93  #endif
 94      if (fcntl(socket_fd, F_SETFL, val) < 0) {
 95  	rcs_print_error("Couldn's set flag for blocking on socket.: %d,%s\n",
 96  	    errno, strerror(errno));
 97  	return -1;
 98      }
 99  #endif
100      return (0);
101  }