gdb/ser-tcp.c

   1 /* Serial interface for raw TCP connections on Un*x like systems
   2    Copyright 1992, 1993 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 #include <netinet/tcp.h>
  29 #include "signals.h"
  30 #include "gdb_string.h"
  31
  32 struct tcp_ttystate
  33 {
  34   int bogus;
  35 };
  36
  37 static int tcp_open PARAMS ((serial_t scb, const char *name));
  38 static void tcp_raw PARAMS ((serial_t scb));
  39 static int wait_for PARAMS ((serial_t scb, int timeout));
  40 static int tcp_readchar PARAMS ((serial_t scb, int timeout));
  41 static int tcp_setbaudrate PARAMS ((serial_t scb, int rate));
  42 static int tcp_setstopbits PARAMS ((serial_t scb, int num));
  43 static int tcp_write PARAMS ((serial_t scb, const char *str, int len));
  44 /* FIXME: static void tcp_restore PARAMS ((serial_t scb)); */
  45 static void tcp_close PARAMS ((serial_t scb));
  46 static serial_ttystate tcp_get_tty_state PARAMS ((serial_t scb));
  47 static int tcp_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
  48
  49 /* Open up a raw tcp socket */
  50
  51 static int
  52 tcp_open(scb, name)
  53      serial_t scb;
  54      const char *name;
  55 {
  56   char *port_str;
  57   int port;
  58   struct hostent *hostent;
  59   struct sockaddr_in sockaddr;
  60   int tmp;
  61   char hostname[100];
  62   struct protoent *protoent;
  63   int i;
  64
  65   port_str = strchr (name, ':');
  66
  67   if (!port_str)
  68     error ("tcp_open: No colon in host name!"); /* Shouldn't ever happen */
  69
  70   tmp = min (port_str - name, (int) sizeof hostname - 1);
  71   strncpy (hostname, name, tmp); /* Don't want colon */
  72   hostname[tmp] = '\000';       /* Tie off host name */
  73   port = atoi (port_str + 1);
  74
  75   hostent = gethostbyname (hostname);
  76
  77   if (!hostent)
  78     {
  79       fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname);
  80       errno = ENOENT;
  81       return -1;
  82     }
  83
  84   for (i = 1; i <= 15; i++)
  85     {
  86       scb->fd = socket (PF_INET, SOCK_STREAM, 0);
  87       if (scb->fd < 0)
  88         return -1;
  89
  90       /* Allow rapid reuse of this port. */
  91       tmp = 1;
  92       setsockopt (scb->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&tmp, sizeof(tmp));
  93
  94       /* Enable TCP keep alive process. */
  95       tmp = 1;
  96       setsockopt (scb->fd, SOL_SOCKET, SO_KEEPALIVE, (char *)&tmp, sizeof(tmp));
  97
  98       sockaddr.sin_family = PF_INET;
  99       sockaddr.sin_port = htons(port);
 100       memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr,
 101               sizeof (struct in_addr));
 102
 103       if (!connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof(sockaddr)))
 104         break;
 105
 106       close (scb->fd);
 107       scb->fd = -1;
 108
 109 /* We retry for ECONNREFUSED because that is often a temporary condition, which
 110    happens when the server is being restarted.  */
 111
 112       if (errno != ECONNREFUSED)
 113         return -1;
 114
 115       sleep (1);
 116     }
 117
 118   protoent = getprotobyname ("tcp");
 119   if (!protoent)
 120     return -1;
 121
 122   tmp = 1;
 123   if (setsockopt (scb->fd, protoent->p_proto, TCP_NODELAY,
 124                   (char *)&tmp, sizeof(tmp)))
 125     return -1;
 126
 127   signal(SIGPIPE, SIG_IGN);     /* If we don't do this, then GDB simply exits
 128                                    when the remote side dies.  */
 129
 130   return 0;
 131 }
 132
 133 static serial_ttystate
 134 tcp_get_tty_state(scb)
 135      serial_t scb;
 136 {
 137   struct tcp_ttystate *state;
 138
 139   state = (struct tcp_ttystate *)xmalloc(sizeof *state);
 140
 141   return (serial_ttystate)state;
 142 }
 143
 144 static int
 145 tcp_set_tty_state(scb, ttystate)
 146      serial_t scb;
 147      serial_ttystate ttystate;
 148 {
 149   struct tcp_ttystate *state;
 150
 151   state = (struct tcp_ttystate *)ttystate;
 152
 153   return 0;
 154 }
 155
 156 static int
 157 tcp_return_0 (scb)
 158      serial_t scb;
 159 {
 160   return 0;
 161 }
 162
 163 static void
 164 tcp_raw(scb)
 165      serial_t scb;
 166 {
 167   return;                       /* Always in raw mode */
 168 }
 169
 170 /* Wait for input on scb, with timeout seconds.  Returns 0 on success,
 171    otherwise SERIAL_TIMEOUT or SERIAL_ERROR.
 172
 173    For termio{s}, we actually just setup VTIME if necessary, and let the
 174    timeout occur in the read() in tcp_read().
 175  */
 176
 177 static int
 178 wait_for(scb, timeout)
 179      serial_t scb;
 180      int timeout;
 181 {
 182   int numfds;
 183   struct timeval tv;
 184   fd_set readfds, exceptfds;
 185
 186   FD_ZERO (&readfds);
 187   FD_ZERO (&exceptfds);
 188
 189   tv.tv_sec = timeout;
 190   tv.tv_usec = 0;
 191
 192   FD_SET(scb->fd, &readfds);
 193   FD_SET(scb->fd, &exceptfds);
 194
 195   while (1)
 196     {
 197       if (timeout >= 0)
 198         numfds = select(scb->fd+1, &readfds, 0, &exceptfds, &tv);
 199       else
 200         numfds = select(scb->fd+1, &readfds, 0, &exceptfds, 0);
 201
 202       if (numfds <= 0)
 203         if (numfds == 0)
 204           return SERIAL_TIMEOUT;
 205         else if (errno == EINTR)
 206           continue;
 207         else
 208           return SERIAL_ERROR;  /* Got an error from select or poll */
 209
 210       return 0;
 211     }
 212 }
 213
 214 /* Read a character with user-specified timeout.  TIMEOUT is number of seconds
 215    to wait, or -1 to wait forever.  Use timeout of 0 to effect a poll.  Returns
 216    char if successful.  Returns -2 if timeout expired, EOF if line dropped
 217    dead, or -3 for any other error (see errno in that case). */
 218
 219 static int
 220 tcp_readchar(scb, timeout)
 221      serial_t scb;
 222      int timeout;
 223 {
 224   int status;
 225
 226   if (scb->bufcnt-- > 0)
 227     return *scb->bufp++;
 228
 229   status = wait_for(scb, timeout);
 230
 231   if (status < 0)
 232     return status;
 233
 234   while (1)
 235     {
 236       scb->bufcnt = read(scb->fd, scb->buf, BUFSIZ);
 237       if (scb->bufcnt != -1 || errno != EINTR)
 238         break;
 239     }
 240
 241   if (scb->bufcnt <= 0)
 242     if (scb->bufcnt == 0)
 243       return SERIAL_TIMEOUT;    /* 0 chars means timeout [may need to
 244                                    distinguish between EOF & timeouts
 245                                    someday] */
 246     else
 247       return SERIAL_ERROR;      /* Got an error from read */
 248
 249   scb->bufcnt--;
 250   scb->bufp = scb->buf;
 251   return *scb->bufp++;
 252 }
 253
 254 static int
 255 tcp_noflush_set_tty_state (scb, new_ttystate, old_ttystate)
 256      serial_t scb;
 257      serial_ttystate new_ttystate;
 258      serial_ttystate old_ttystate;
 259 {
 260   return 0;
 261 }
 262
 263 static void
 264 tcp_print_tty_state (scb, ttystate)
 265      serial_t scb;
 266      serial_ttystate ttystate;
 267 {
 268   /* Nothing to print.  */
 269   return;
 270 }
 271
 272 static int
 273 tcp_setbaudrate(scb, rate)
 274      serial_t scb;
 275      int rate;
 276 {
 277   return 0;                     /* Never fails! */
 278 }
 279
 280 static int
 281 tcp_setstopbits(scb, num)
 282      serial_t scb;
 283      int num;
 284 {
 285   return 0;                     /* Never fails! */
 286 }
 287
 288 static int
 289 tcp_write(scb, str, len)
 290      serial_t scb;
 291      const char *str;
 292      int len;
 293 {
 294   int cc;
 295
 296   while (len > 0)
 297     {
 298       cc = write(scb->fd, str, len);
 299
 300       if (cc < 0)
 301         return 1;
 302       len -= cc;
 303       str += cc;
 304     }
 305   return 0;
 306 }
 307
 308 static void
 309 tcp_close(scb)
 310      serial_t scb;
 311 {
 312   if (scb->fd < 0)
 313     return;
 314
 315   close(scb->fd);
 316   scb->fd = -1;
 317 }
 318
 319 static struct serial_ops tcp_ops =
 320 {
 321   "tcp",
 322   0,
 323   tcp_open,
 324   tcp_close,
 325   tcp_readchar,
 326   tcp_write,
 327   tcp_return_0, /* flush output */
 328   tcp_return_0, /* flush input */
 329   tcp_return_0, /* send break */
 330   tcp_raw,
 331   tcp_get_tty_state,
 332   tcp_set_tty_state,
 333   tcp_print_tty_state,
 334   tcp_noflush_set_tty_state,
 335   tcp_setbaudrate,
 336   tcp_setstopbits,
 337 };
 338
 339 void
 340 _initialize_ser_tcp ()
 341 {
 342   serial_add_interface (&tcp_ops);
 343 }