src/src/System/Link/socket_link.cpp

   1
   2 /******************************************************************************
   3 * MODULE     : socket_link.cpp
   4 * DESCRIPTION: TeXmacs links by sockets
   5 * COPYRIGHT  : (C) 2003  Joris van der Hoeven
   6 * THANKS     : Beej's Guide to Network Programming has been helpful
   7 *******************************************************************************
   8 * This software falls under the GNU general public license version 3 or later.
   9 * It comes WITHOUT ANY WARRANTY WHATSOEVER. For details, see the file LICENSE
  10 * in the root directory or <http://www.gnu.org/licenses/gpl-3.0.html>.
  11 ******************************************************************************/
  12
  13 #include "socket_link.hpp"
  14 #include "sys_utils.hpp"
  15 #include "hashset.hpp"
  16 #include "iterator.hpp"
  17 #include "timer.hpp"
  18 #include "Scheme/object.hpp"
  19 #include <stdio.h>
  20 #include <string.h>
  21 #ifndef __MINGW32__
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24 #include <sys/wait.h>
  25 #include <sys/types.h>
  26 #include <sys/socket.h>
  27 #include <netinet/in.h>
  28 #include <netdb.h>
  29 #endif
  30 #include <errno.h>
  31
  32 hashset<pointer> socket_link_set;
  33 void socket_callback (void *obj, void* info);
  34
  35 /******************************************************************************
  36 * Constructors and destructors for socket_links
  37 ******************************************************************************/
  38
  39 socket_link_rep::socket_link_rep (string host2, int port2, int type2, int fd):
  40   host (host2), port (port2), type (type2)
  41 {
  42   socket_link_set->insert ((pointer) this);
  43   io     = fd;
  44   outbuf = "";
  45   alive  = (fd != -1);
  46   if (type == SOCKET_SERVER) call ("server-add", object (io));
  47   else if (type == SOCKET_CLIENT) call ("client-add");
  48 }
  49
  50 socket_link_rep::~socket_link_rep () {
  51   stop ();
  52   socket_link_set->remove ((pointer) this);
  53 }
  54
  55 tm_link
  56 make_socket_link (string host, int port, int type, int fd) {
  57   return tm_new<socket_link_rep> (host, port, type, fd);
  58 }
  59
  60 tm_link
  61 find_socket_link (int fd) {
  62   iterator<pointer> it= iterate (socket_link_set);
  63   while (it->busy()) {
  64     socket_link_rep* con= (socket_link_rep*) it->next();
  65     if (con->io == fd && con->alive) return tm_link (con);
  66   }
  67   return tm_link ();
  68 }
  69
  70 void
  71 close_all_sockets () {
  72 #ifndef __MINGW32__
  73   iterator<pointer> it= iterate (socket_link_set);
  74   while (it->busy()) {
  75     socket_link_rep* con= (socket_link_rep*) it->next();
  76     if (con->alive) {
  77       // FIXME: cleanly close the connection to the socket here
  78       con->alive= false;
  79     }
  80   }
  81 #endif
  82 }
  83
  84 /******************************************************************************
  85 * Routines for socket_links
  86 ******************************************************************************/
  87
  88 string
  89 socket_link_rep::start () {
  90 #ifndef __MINGW32__
  91   if (alive) return "busy";
  92   if (DEBUG_AUTO)
  93     cout << "TeXmacs] Connecting to '" << host << ":" << port << "'\n";
  94
  95   // getting host
  96   char* _host= as_charp (host);
  97   struct hostent *hp = gethostbyname (_host);
  98   tm_delete_array (_host);
  99   if (hp == NULL) return "Error: no connection for '" * host * "'";
 100
 101   // creating socket
 102   io= socket (AF_INET, SOCK_STREAM, 0);
 103   if (io < 0) return "Error: socket could not be created";
 104
 105   // connecting to socket
 106   struct sockaddr_in insock;
 107   string where= host * ":" * as_string (port);
 108   memset ((char*) &insock, 0, sizeof (insock));
 109   insock.sin_family = AF_INET;
 110   insock.sin_port = htons ((unsigned short) port);
 111   memcpy ((char*) &insock.sin_addr, hp->h_addr, hp->h_length);
 112   if (connect (io, (struct sockaddr*) &insock, sizeof (insock)) < 0)
 113     return "Error: refused connection to '" * where * "'";
 114
 115   // testing whether it works
 116   int flags = O_NONBLOCK;
 117   if (fcntl (io, F_SETFL, flags) < 0)
 118     return "Error: non working connection to '" * where * "'";
 119   alive = true;
 120   sn = socket_notifier (io, &socket_callback, this, NULL);
 121   return "ok";
 122 #else
 123   return "Error: sockets not implemented";
 124 #endif
 125 }
 126
 127 static string
 128 debug_io_string (string s) {
 129   int i, n= N(s);
 130   string r;
 131   for (i=0; i<n; i++) {
 132     unsigned char c= (unsigned char) s[i];
 133     if (c == DATA_BEGIN) r << "[BEGIN]";
 134     else if (c == DATA_END) r << "[END]";
 135     else if (c == DATA_COMMAND) r << "[COMMAND]";
 136     else if (c == DATA_ESCAPE) r << "[ESCAPE]";
 137     else r << s[i];
 138   }
 139   return r;
 140 }
 141
 142 static int
 143 send_all (int s, char *buf, int *len) {
 144 #ifndef __MINGW32__
 145   int total= 0;          // how many bytes we've sent
 146   int bytes_left= *len;  // how many we have left to send
 147   int n= 0;
 148
 149   while (total < *len) {
 150     n= send (s, buf + total, bytes_left, 0);
 151     if (n == -1) break;
 152     total += n;
 153     bytes_left -= n;
 154   }
 155
 156   *len= total;
 157   return n==-1? -1: 0;
 158 #else
 159   return 0;
 160 #endif
 161 }
 162
 163
 164 void
 165 socket_link_rep::write (string s, int channel) {
 166   if ((!alive) || (channel != LINK_IN)) return;
 167   if (DEBUG_IO) cout << "---> " << debug_io_string (s) << "\n";
 168   int len= N(s);
 169   if (send_all (io, &(s[0]), &len) == -1) {
 170     cerr << "TeXmacs] write to '" << host << ":" << port << "' failed\n";
 171     stop ();
 172   }
 173 }
 174
 175 void
 176 socket_link_rep::feed (int channel) {
 177 #ifndef __MINGW32__
 178   if ((!alive) || (channel != LINK_OUT)) return;
 179   char tempout[1024];
 180   int r= recv (io, tempout, 1024, 0);
 181   if (r <= 0) {
 182     if (r == 0) cout << "TeXmacs] '" << host << ":" << port << "' hung up\n";
 183     else cerr << "TeXmacs] read failed from '" << host << ":" << port << "'\n";
 184     stop ();
 185   }
 186   else if (r != 0) {
 187     if (DEBUG_IO) cout << debug_io_string (string (tempout, r));
 188     outbuf << string (tempout, r);
 189   }
 190 #endif
 191 }
 192
 193 string&
 194 socket_link_rep::watch (int channel) {
 195   static string empty_string= "";
 196   if (channel == LINK_OUT) return outbuf;
 197   else return empty_string;
 198 }
 199
 200 string
 201 socket_link_rep::read (int channel) {
 202   if (channel == LINK_OUT) {
 203     string r= outbuf;
 204     outbuf= "";
 205     return r;
 206   }
 207   else return "";
 208 }
 209
 210 void
 211 socket_link_rep::listen (int msecs) {
 212 #ifndef __MINGW32__
 213   if (!alive) return;
 214   fd_set rfds;
 215   FD_ZERO (&rfds);
 216   FD_SET (io, &rfds);
 217   struct timeval tv;
 218   tv.tv_sec  = msecs / 1000;
 219   tv.tv_usec = 1000 * (msecs % 1000);
 220   int nr= select (io+1, &rfds, NULL, NULL, &tv);
 221   if (nr != 0 && FD_ISSET (io, &rfds)) feed (LINK_OUT);
 222 #endif
 223 }
 224
 225 void
 226 socket_link_rep::interrupt () {
 227 }
 228
 229 void
 230 socket_link_rep::stop () {
 231 #ifndef __MINGW32__
 232   if (!alive) return;
 233   if (type == SOCKET_SERVER) call ("server-remove", object (io));
 234   else if (type == SOCKET_CLIENT) call ("client-remove");
 235   close (io);
 236   io= -1;
 237   alive= false;
 238   sn = socket_notifier ();
 239   wait (NULL);
 240 #endif
 241 }
 242
 243 /******************************************************************************
 244 * Call back for new information on socket
 245 ******************************************************************************/
 246
 247 void
 248 socket_callback (void *obj, void* info) {
 249 #ifndef __MINGW32__
 250   (void) info;
 251   socket_link_rep* con= (socket_link_rep*) obj;
 252   bool busy= true;
 253   bool news= false;
 254   while (busy) {
 255     fd_set rfds;
 256     FD_ZERO (&rfds);
 257     int max_fd= con->io + 1;
 258     FD_SET (con->io, &rfds);
 259
 260     struct timeval tv;
 261     tv.tv_sec  = 0;
 262     tv.tv_usec = 0;
 263     select (max_fd, &rfds, NULL, NULL, &tv);
 264
 265     busy= false;
 266     if (con->alive && FD_ISSET (con->io, &rfds)) {
 267       //cout << "socket_callback OUT" << LF;
 268       con->feed (LINK_OUT);
 269       busy= news= true;
 270     }
 271   }
 272   if (!is_nil (con->feed_cmd) && news)
 273     con->feed_cmd->apply ();
 274 #endif
 275 }