mnc.c

   1 /*  mnc: mini-netcat - built from the ground up for LRP
   2     Copyright (C) 1998  Charles P. Wright
   3
   4     0.0.1   6K      It works.
   5     0.0.2   5K      Smaller and you can also check the exit condition if you wish.
   6
   7
   8     19980918 Busy Boxed! Dave Cinege
   9
  10     This program is free software; you can redistribute it and/or modify
  11     it under the terms of the GNU General Public License as published by
  12     the Free Software Foundation; either version 2 of the License, or
  13     (at your option) any later version.
  14
  15     This program is distributed in the hope that it will be useful,
  16     but WITHOUT ANY WARRANTY; without even the implied warranty of
  17     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18     GNU General Public License for more details.
  19
  20     You should have received a copy of the GNU General Public License
  21     along with this program; if not, write to the Free Software
  22     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23
  24 */
  25 #include "internal.h"
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29
  30 #include <sys/types.h>
  31 #include <sys/socket.h>
  32 #include <netinet/in.h>
  33 #include <arpa/inet.h>
  34 #include <netdb.h>
  35 #include <sys/time.h>
  36 #include <sys/ioctl.h>
  37
  38 const char mnc_usage[] =
  39 "mini-netcat 0.0.1 -- Open pipe to IP:port\n"
  40 "\tmnc [IP] [port]\n";
  41
  42 int
  43 mnc_main(struct FileInfo * i, int argc, char **argv)
  44 {
  45
  46         int sfd;
  47         int result;
  48         int len;
  49         int pid;
  50         char ch;
  51
  52         struct sockaddr_in address;
  53         struct hostent *hostinfo;
  54
  55 #ifdef SELECT
  56         fd_set readfds, testfds;
  57 #endif
  58
  59         sfd = socket(AF_INET, SOCK_STREAM, 0);
  60
  61         hostinfo = (struct hostent *) gethostbyname(argv[1]);
  62
  63         if (!hostinfo)
  64         {
  65                 exit(1);
  66         }
  67
  68         address.sin_family = AF_INET;
  69         address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
  70         address.sin_port = htons(atoi(argv[2]));
  71
  72         len = sizeof(address);
  73
  74         result = connect(sfd, (struct sockaddr *)&address, len);
  75
  76         if (result < 0)
  77         {
  78                 exit(2);
  79         }
  80
  81 #ifdef SELECT
  82         FD_ZERO(&readfds);
  83         FD_SET(sfd, &readfds);
  84         FD_SET(fileno(stdin), &readfds);
  85
  86         while(1)
  87         {
  88                 int fd;
  89                 int nread;
  90
  91                 testfds = readfds;
  92
  93                 result = select(FD_SETSIZE, &testfds, (fd_set *) NULL, (fd_set *) NULL, (struct timeval *) 0);
  94
  95                 if(result < 1)
  96                 {
  97                         exit(3);
  98                 }
  99
 100                 for(fd = 0; fd < FD_SETSIZE; fd++)
 101                 {
 102                         if(FD_ISSET(fd,&testfds))
 103                         {
 104                                 ioctl(fd, FIONREAD, &nread);
 105
 106                                 if (nread == 0)
 107                                         exit(0);
 108
 109                                 if(fd == sfd)
 110                                 {
 111                                         read(sfd, &ch, 1);
 112                                         write(fileno(stdout), &ch, 1);
 113                                 }
 114                                 else
 115                                 {
 116                                         read(fileno(stdin), &ch, 1);
 117                                         write(sfd, &ch, 1);
 118                                 }
 119                         }
 120                 }
 121         }
 122 #else
 123         pid = fork();
 124
 125         if (!pid)
 126         {
 127                 int retval;
 128                 retval = 1;
 129                 while(retval == 1)
 130                 {
 131                         retval = read(fileno(stdin), &ch, 1);
 132                         write(sfd, &ch, 1);
 133                 }
 134         }
 135         else
 136         {
 137                 int retval;
 138                 retval = 1;
 139                 while(retval == 1)
 140                 {
 141                         retval = read(sfd, &ch, 1);
 142                         write(fileno(stdout), &ch, 1);
 143                 }
 144         }
 145
 146         exit(0);
 147 #endif
 148 }