apps/nc/main.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2007  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *  Copyright (C) 2008  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   5  *  Copyright (C) 2009  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   6  *
   7  *  This program is free software: you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation, either version 3 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21
  22 #include <fcntl.h>
  23 #include <netdb.h>
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <arpa/inet.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31
  32 #define         ESC     1
  33
  34 static struct sockaddr_in serverSock;   // Remote connection
  35 static struct hostent *host;            // Remote host
  36 static int ncsock;                      // Socket
  37 static int size;                        // Count of input/output bytes
  38 static char *buf;                       // Buffer
  39 static char *msg;
  40
  41 unsigned key_pressed (int keycode)
  42 {
  43         int scancode = getkey ();
  44
  45         if (scancode == keycode)
  46                 return 1;
  47
  48         if (scancode == keycode+128)
  49                 return 2;
  50         else
  51                 return 0;
  52 }
  53
  54 static int send_to_socket (char *data, unsigned len)
  55 {
  56         int ret;
  57         if ((ret = send (ncsock, data, len, 0)) == -1) {
  58                 printf ("ERROR -> send () = -1\n");
  59                 return -1;
  60         }
  61
  62         return ret;
  63 }
  64
  65 static int handle_input ()
  66 {
  67         char i = getch ();
  68
  69         if (i) {
  70                 setcolor (7, 0);
  71
  72                 putch (i);
  73
  74                 if (size < 64) {
  75                         msg[size] = i;
  76                         size ++;
  77                 }
  78
  79                 if (i == '\n') {
  80                         send_to_socket (msg, size);
  81                         size = 0;
  82                 }
  83         }
  84
  85         if (key_pressed (ESC))
  86                 return -1;
  87
  88         return 1;
  89 }
  90
  91 static int nc_init (const char *addr, int port)
  92 {
  93         // Let's get info about remote computer
  94         if ((host = gethostbyname ((char *) addr)) == NULL) {
  95                 printf ("Wrong address -> %s:%d\n", addr, port);
  96                 return 0;
  97         }
  98
  99         // Create socket
 100         if ((ncsock = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
 101                 printf ("Cant create socket\n");
 102                 return 0;
 103         }
 104
 105         // Fill structure sockaddr_in
 106         // 1) Family of protocols
 107         serverSock.sin_family = AF_INET;
 108         // 2) Number of server port
 109         serverSock.sin_port = htons (port);
 110         // 3) Setup ip address of server, where we want to connect
 111         memcpy (&(serverSock.sin_addr), host->h_addr, host->h_length);
 112
 113         // Now we are able to connect to remote server
 114         if (connect (ncsock, (struct sockaddr *) &serverSock, sizeof (serverSock)) == -1) {
 115                 printf ("Connection cant be estabilished -> %s:%d\n", addr, port);
 116                 return -1;
 117         }
 118
 119         // Set socket to non-blocking mode
 120         int oldFlag = fcntl (ncsock, F_GETFL, 0);
 121         if (fcntl (ncsock, F_SETFL, oldFlag | O_NONBLOCK) == -1) {
 122                 printf ("Cant set socket to nonblocking mode\n");
 123                 return 0;
 124         }
 125
 126         printf ("netcat -> connected to %s:%d\n", addr, port);
 127
 128         buf = (char *) malloc (sizeof (char) * 500);                    // receive buffer
 129
 130         if (!buf)
 131                 return 0;
 132
 133         msg = (char *) malloc (sizeof (char) * 64);
 134
 135         if (!msg)
 136                 return 0;
 137
 138         size = 0;
 139
 140         return 1;
 141 }
 142
 143 static int nc_loop ()
 144 {
 145         int ret = recv (ncsock, buf, 499, 0);
 146
 147         if (handle_input () == -1)
 148                 return -1;
 149
 150         if (ret > 0) {
 151                 setcolor (14, 0);
 152                 buf[ret] = '\0';
 153                 printf (buf);
 154         } else {
 155                 if (ret == -1)
 156                         printf ("HOST -> Connection refused\n");
 157         }
 158
 159         return ret;
 160 }
 161
 162 void syntax ()
 163 {
 164         printf ("nc: <address> <port>\nGNU/GPL3 - Coded by ZeXx86\n");
 165 }
 166
 167 int main (int argc, char **argv)
 168 {
 169         if (argc < 3) {
 170                 syntax ();
 171                 return 0;
 172         }
 173
 174         const int port = atoi (argv[2]);
 175
 176         if (!port) {
 177                 syntax ();
 178                 return 0;
 179         }
 180
 181         int ret = nc_init ((char *) argv[1], port);
 182
 183         if (ret < 1)
 184                 goto end;
 185
 186         while (1) {
 187                 ret = nc_loop ();
 188                 if (ret == -1)
 189                         break;
 190
 191                 schedule ();
 192         }
 193
 194         free (msg);
 195         free (buf);
 196 end:
 197         printf ("netcat -> Bye !\n");
 198
 199         close (ncsock);
 200
 201         return 0;
 202 }
 203