gdb/ser-tcp.c

   1 /* Serial interface for raw TCP connections on Un*x like systems
   2    Copyright 1992, 1993, 1998 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #include "defs.h"
  21 #include "serial.h"
  22 #include <sys/types.h>
  23 #include <sys/time.h>
  24 #include <netinet/in.h>
  25 #include <arpa/inet.h>
  26 #include <netdb.h>
  27 #include <sys/socket.h>
  28
  29 #ifndef __CYGWIN__
  30 #include <netinet/tcp.h>
  31 #endif
  32
  33 #include "signals.h"
  34 #include "gdb_string.h"
  35
  36 struct tcp_ttystate
  37 {
  38   int bogus;
  39 };
  40
  41 static int tcp_open PARAMS ((serial_t scb, const char *name));
  42 static void tcp_raw PARAMS ((serial_t scb));
  43 static int wait_for PARAMS ((serial_t scb, int timeout));
  44 static int tcp_readchar PARAMS ((serial_t scb, int timeout));
  45 static int tcp_setbaudrate PARAMS ((serial_t scb, int rate));
  46 static int tcp_setstopbits PARAMS ((serial_t scb, int num));
  47 static int tcp_write PARAMS ((serial_t scb, const char *str, int len));
  48 /* FIXME: static void tcp_restore PARAMS ((serial_t scb)); */
  49 static void tcp_close PARAMS ((serial_t scb));
  50 static serial_ttystate tcp_get_tty_state PARAMS ((serial_t scb));
  51 static int tcp_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
  52 static int tcp_return_0 PARAMS ((serial_t));
  53 static int tcp_noflush_set_tty_state PARAMS ((serial_t, serial_ttystate,
  54                                               serial_ttystate));
  55 static void tcp_print_tty_state PARAMS ((serial_t, serial_ttystate));
  56
  57 void _initialize_ser_tcp PARAMS ((void));
  58
  59 /* Open up a raw tcp socket */
  60
  61 static int
  62 tcp_open(scb, name)
  63      serial_t scb;
  64      const char *name;
  65 {
  66   char *port_str;
  67   int port;
  68   struct hostent *hostent;
  69   struct sockaddr_in sockaddr;
  70   int tmp;
  71   char hostname[100];
  72   struct protoent *protoent;
  73   int i;
  74
  75   port_str = strchr (name, ':');
  76
  77   if (!port_str)
  78     error ("tcp_open: No colon in host name!"); /* Shouldn't ever happen */
  79
  80   tmp = min (port_str - name, (int) sizeof hostname - 1);
  81   strncpy (hostname, name, tmp); /* Don't want colon */
  82   hostname[tmp] = '\000';       /* Tie off host name */
  83   port = atoi (port_str + 1);
  84
  85   hostent = gethostbyname (hostname);
  86
  87   if (!hostent)
  88     {
  89       fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname);
  90       errno = ENOENT;
  91       return -1;
  92     }
  93
  94   for (i = 1; i <= 15; i++)
  95     {
  96       scb->fd = socket (PF_INET, SOCK_STREAM, 0);
  97       if (scb->fd < 0)
  98         return -1;
  99
 100       /* Allow rapid reuse of this port. */
 101       tmp = 1;
 102       setsockopt (scb->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&tmp, sizeof(tmp));
 103
 104       /* Enable TCP keep alive process. */
 105       tmp = 1;
 106       setsockopt (scb->fd, SOL_SOCKET, SO_KEEPALIVE, (char *)&tmp, sizeof(tmp));
 107
 108       sockaddr.sin_family = PF_INET;
 109       sockaddr.sin_port = htons(port);
 110       memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr,
 111               sizeof (struct in_addr));
 112
 113       if (!connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof(sockaddr)))
 114         break;
 115
 116       close (scb->fd);
 117       scb->fd = -1;
 118
 119 /* We retry for ECONNREFUSED because that is often a temporary condition, which
 120    happens when the server is being restarted.  */
 121
 122       if (errno != ECONNREFUSED)
 123         return -1;
 124
 125       sleep (1);
 126     }
 127
 128   protoent = getprotobyname ("tcp");
 129   if (!protoent)
 130     return -1;
 131
 132   tmp = 1;
 133   if (setsockopt (scb->fd, protoent->p_proto, TCP_NODELAY,
 134                   (char *)&tmp, sizeof(tmp)))
 135     return -1;
 136
 137   signal(SIGPIPE, SIG_IGN);     /* If we don't do this, then GDB simply exits
 138                                    when the remote side dies.  */
 139
 140   return 0;
 141 }
 142
 143 static serial_ttystate
 144 tcp_get_tty_state(scb)
 145      serial_t scb;
 146 {
 147   struct tcp_ttystate *state;
 148
 149   state = (struct tcp_ttystate *)xmalloc(sizeof *state);
 150
 151   return (serial_ttystate)state;
 152 }
 153
 154 static int
 155 tcp_set_tty_state(scb, ttystate)
 156      serial_t scb;
 157      serial_ttystate ttystate;
 158 {
 159   struct tcp_ttystate *state;
 160
 161   state = (struct tcp_ttystate *)ttystate;
 162
 163   return 0;
 164 }
 165
 166 static int
 167 tcp_return_0 (scb)
 168      serial_t scb;
 169 {
 170   return 0;
 171 }
 172
 173 static void
 174 tcp_raw(scb)
 175      serial_t scb;
 176 {
 177   return;                       /* Always in raw mode */
 178 }
 179
 180 /* Wait for input on scb, with timeout seconds.  Returns 0 on success,
 181    otherwise SERIAL_TIMEOUT or SERIAL_ERROR.
 182
 183    For termio{s}, we actually just setup VTIME if necessary, and let the
 184    timeout occur in the read() in tcp_read().
 185  */
 186
 187 static int
 188 wait_for (scb, timeout)
 189      serial_t scb;
 190      int timeout;
 191 {
 192   int numfds;
 193   struct timeval tv;
 194   fd_set readfds, exceptfds;
 195
 196   FD_ZERO (&readfds);
 197   FD_ZERO (&exceptfds);
 198
 199   tv.tv_sec = timeout;
 200   tv.tv_usec = 0;
 201
 202   FD_SET(scb->fd, &readfds);
 203   FD_SET(scb->fd, &exceptfds);
 204
 205   while (1)
 206     {
 207       if (timeout >= 0)
 208         numfds = select(scb->fd+1, &readfds, 0, &exceptfds, &tv);
 209       else
 210         numfds = select(scb->fd+1, &readfds, 0, &exceptfds, 0);
 211
 212       if (numfds <= 0)
 213         {
 214           if (numfds == 0)
 215             return SERIAL_TIMEOUT;
 216           else if (errno == EINTR)
 217             continue;
 218           else
 219             return SERIAL_ERROR;        /* Got an error from select or poll */
 220         }
 221
 222       return 0;
 223     }
 224 }
 225
 226 /* Read a character with user-specified timeout.  TIMEOUT is number of seconds
 227    to wait, or -1 to wait forever.  Use timeout of 0 to effect a poll.  Returns
 228    char if successful.  Returns -2 if timeout expired, EOF if line dropped
 229    dead, or -3 for any other error (see errno in that case). */
 230
 231 static int
 232 tcp_readchar (scb, timeout)
 233      serial_t scb;
 234      int timeout;
 235 {
 236   int status;
 237
 238   if (scb->bufcnt-- > 0)
 239     return *scb->bufp++;
 240
 241   status = wait_for(scb, timeout);
 242
 243   if (status < 0)
 244     return status;
 245
 246   while (1)
 247     {
 248       scb->bufcnt = read(scb->fd, scb->buf, BUFSIZ);
 249       if (scb->bufcnt != -1 || errno != EINTR)
 250         break;
 251     }
 252
 253   if (scb->bufcnt <= 0)
 254     {
 255       if (scb->bufcnt == 0)
 256         return SERIAL_TIMEOUT;  /* 0 chars means timeout [may need to
 257                                      distinguish between EOF & timeouts
 258                                      someday] */
 259       else
 260         return SERIAL_ERROR;    /* Got an error from read */
 261     }
 262
 263   scb->bufcnt--;
 264   scb->bufp = scb->buf;
 265   return *scb->bufp++;
 266 }
 267
 268 static int
 269 tcp_noflush_set_tty_state (scb, new_ttystate, old_ttystate)
 270      serial_t scb;
 271      serial_ttystate new_ttystate;
 272      serial_ttystate old_ttystate;
 273 {
 274   return 0;
 275 }
 276
 277 static void
 278 tcp_print_tty_state (scb, ttystate)
 279      serial_t scb;
 280      serial_ttystate ttystate;
 281 {
 282   /* Nothing to print.  */
 283   return;
 284 }
 285
 286 static int
 287 tcp_setbaudrate(scb, rate)
 288      serial_t scb;
 289      int rate;
 290 {
 291   return 0;                     /* Never fails! */
 292 }
 293
 294 static int
 295 tcp_setstopbits(scb, num)
 296      serial_t scb;
 297      int num;
 298 {
 299   return 0;                     /* Never fails! */
 300 }
 301
 302 static int
 303 tcp_write(scb, str, len)
 304      serial_t scb;
 305      const char *str;
 306      int len;
 307 {
 308   int cc;
 309
 310   while (len > 0)
 311     {
 312       cc = write(scb->fd, str, len);
 313
 314       if (cc < 0)
 315         return 1;
 316       len -= cc;
 317       str += cc;
 318     }
 319   return 0;
 320 }
 321
 322 static void
 323 tcp_close(scb)
 324      serial_t scb;
 325 {
 326   if (scb->fd < 0)
 327     return;
 328
 329   close(scb->fd);
 330   scb->fd = -1;
 331 }
 332
 333 static struct serial_ops tcp_ops =
 334 {
 335   "tcp",
 336   0,
 337   tcp_open,
 338   tcp_close,
 339   tcp_readchar,
 340   tcp_write,
 341   tcp_return_0, /* flush output */
 342   tcp_return_0, /* flush input */
 343   tcp_return_0, /* send break */
 344   tcp_raw,
 345   tcp_get_tty_state,
 346   tcp_set_tty_state,
 347   tcp_print_tty_state,
 348   tcp_noflush_set_tty_state,
 349   tcp_setbaudrate,
 350   tcp_setstopbits,
 351   tcp_return_0, /* wait for output to drain */
 352 };
 353
 354 void
 355 _initialize_ser_tcp ()
 356 {
 357   serial_add_interface (&tcp_ops);
 358 }