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., 675 Mass Ave, Cambridge, MA 02139, 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
  31 struct tcp_ttystate
  32 {
  33   int bogus;
  34 };
  35
  36 static int tcp_open PARAMS ((serial_t scb, const char *name));
  37 static void tcp_raw PARAMS ((serial_t scb));
  38 static int wait_for PARAMS ((serial_t scb, int timeout));
  39 static int tcp_readchar PARAMS ((serial_t scb, int timeout));
  40 static int tcp_setbaudrate PARAMS ((serial_t scb, int rate));
  41 static int tcp_setstopbits PARAMS ((serial_t scb, int num));
  42 static int tcp_write PARAMS ((serial_t scb, const char *str, int len));
  43 /* FIXME: static void tcp_restore PARAMS ((serial_t scb)); */
  44 static void tcp_close PARAMS ((serial_t scb));
  45 static serial_ttystate tcp_get_tty_state PARAMS ((serial_t scb));
  46 static int tcp_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
  47
  48 /* Open up a raw tcp socket */
  49
  50 static int
  51 tcp_open(scb, name)
  52      serial_t scb;
  53      const char *name;
  54 {
  55   char *port_str;
  56   int port;
  57   struct hostent *hostent;
  58   struct sockaddr_in sockaddr;
  59   int tmp;
  60   char hostname[100];
  61   struct protoent *protoent;
  62
  63   port_str = strchr (name, ':');
  64
  65   if (!port_str)
  66     error ("tcp_open: No colon in host name!"); /* Shouldn't ever happen */
  67
  68   tmp = min (port_str - name, sizeof hostname - 1);
  69   strncpy (hostname, name, tmp); /* Don't want colon */
  70   hostname[tmp] = '\000';       /* Tie off host name */
  71   port = atoi (port_str + 1);
  72
  73   hostent = gethostbyname (hostname);
  74
  75   if (!hostent)
  76     {
  77       fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname);
  78       errno = ENOENT;
  79       return -1;
  80     }
  81
  82   for (i = 1; i <= 15; i++)
  83     {
  84       scb->fd = socket (PF_INET, SOCK_STREAM, 0);
  85       if (scb->fd < 0)
  86         return -1;
  87
  88       /* Allow rapid reuse of this port. */
  89       tmp = 1;
  90       setsockopt (scb->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&tmp, sizeof(tmp));
  91
  92       /* Enable TCP keep alive process. */
  93       tmp = 1;
  94       setsockopt (scb->fd, SOL_SOCKET, SO_KEEPALIVE, (char *)&tmp, sizeof(tmp));
  95
  96       sockaddr.sin_family = PF_INET;
  97       sockaddr.sin_port = htons(port);
  98       memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr,
  99               sizeof (struct in_addr));
 100
 101       if (!connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof(sockaddr)))
 102         break;
 103
 104       close (scb->fd);
 105       scb->fd = -1;
 106
 107 /* We retry for ECONNREFUSED because that is often a temporary condition, which
 108    happens when the server is being restarted.  */
 109
 110       if (errno != ECONNREFUSED)
 111         return -1;
 112
 113       sleep (1);
 114     }
 115
 116   protoent = getprotobyname ("tcp");
 117   if (!protoent)
 118     return -1;
 119
 120   tmp = 1;
 121   if (setsockopt (scb->fd, protoent->p_proto, TCP_NODELAY,
 122                   (char *)&tmp, sizeof(tmp)))
 123     return -1;
 124
 125   signal(SIGPIPE, SIG_IGN);     /* If we don't do this, then GDB simply exits
 126                                    when the remote side dies.  */
 127
 128   return 0;
 129 }
 130
 131 static serial_ttystate
 132 tcp_get_tty_state(scb)
 133      serial_t scb;
 134 {
 135   struct tcp_ttystate *state;
 136
 137   state = (struct tcp_ttystate *)xmalloc(sizeof *state);
 138
 139   return (serial_ttystate)state;
 140 }
 141
 142 static int
 143 tcp_set_tty_state(scb, ttystate)
 144      serial_t scb;
 145      serial_ttystate ttystate;
 146 {
 147   struct tcp_ttystate *state;
 148
 149   state = (struct tcp_ttystate *)ttystate;
 150
 151   return 0;
 152 }
 153
 154 static int
 155 tcp_return_0 (scb)
 156      serial_t scb;
 157 {
 158   return 0;
 159 }
 160
 161 static void
 162 tcp_raw(scb)
 163      serial_t scb;
 164 {
 165   return;                       /* Always in raw mode */
 166 }
 167
 168 /* Wait for input on scb, with timeout seconds.  Returns 0 on success,
 169    otherwise SERIAL_TIMEOUT or SERIAL_ERROR.
 170
 171    For termio{s}, we actually just setup VTIME if necessary, and let the
 172    timeout occur in the read() in tcp_read().
 173  */
 174
 175 static int
 176 wait_for(scb, timeout)
 177      serial_t scb;
 178      int timeout;
 179 {
 180   int numfds;
 181   struct timeval tv;
 182   fd_set readfds, exceptfds;
 183
 184   FD_ZERO (&readfds);
 185   FD_ZERO (&exceptfds);
 186
 187   tv.tv_sec = timeout;
 188   tv.tv_usec = 0;
 189
 190   FD_SET(scb->fd, &readfds);
 191   FD_SET(scb->fd, &exceptfds);
 192
 193   while (1)
 194     {
 195       if (timeout >= 0)
 196         numfds = select(scb->fd+1, &readfds, 0, &exceptfds, &tv);
 197       else
 198         numfds = select(scb->fd+1, &readfds, 0, &exceptfds, 0);
 199
 200       if (numfds <= 0)
 201         if (numfds == 0)
 202           return SERIAL_TIMEOUT;
 203         else if (errno == EINTR)
 204           continue;
 205         else
 206           return SERIAL_ERROR;  /* Got an error from select or poll */
 207
 208       return 0;
 209     }
 210 }
 211
 212 /* Read a character with user-specified timeout.  TIMEOUT is number of seconds
 213    to wait, or -1 to wait forever.  Use timeout of 0 to effect a poll.  Returns
 214    char if successful.  Returns -2 if timeout expired, EOF if line dropped
 215    dead, or -3 for any other error (see errno in that case). */
 216
 217 static int
 218 tcp_readchar(scb, timeout)
 219      serial_t scb;
 220      int timeout;
 221 {
 222   int status;
 223
 224   if (scb->bufcnt-- > 0)
 225     return *scb->bufp++;
 226
 227   status = wait_for(scb, timeout);
 228
 229   if (status < 0)
 230     return status;
 231
 232   while (1)
 233     {
 234       scb->bufcnt = read(scb->fd, scb->buf, BUFSIZ);
 235       if (scb->bufcnt != -1 || errno != EINTR)
 236         break;
 237     }
 238
 239   if (scb->bufcnt <= 0)
 240     if (scb->bufcnt == 0)
 241       return SERIAL_TIMEOUT;    /* 0 chars means timeout [may need to
 242                                    distinguish between EOF & timeouts
 243                                    someday] */
 244     else
 245       return SERIAL_ERROR;      /* Got an error from read */
 246
 247   scb->bufcnt--;
 248   scb->bufp = scb->buf;
 249   return *scb->bufp++;
 250 }
 251
 252 static int
 253 tcp_noflush_set_tty_state (scb, new_ttystate, old_ttystate)
 254      serial_t scb;
 255      serial_ttystate new_ttystate;
 256      serial_ttystate old_ttystate;
 257 {
 258   return 0;
 259 }
 260
 261 static void
 262 tcp_print_tty_state (scb, ttystate)
 263      serial_t scb;
 264      serial_ttystate ttystate;
 265 {
 266   /* Nothing to print.  */
 267   return;
 268 }
 269
 270 static int
 271 tcp_setbaudrate(scb, rate)
 272      serial_t scb;
 273      int rate;
 274 {
 275   return 0;                     /* Never fails! */
 276 }
 277
 278 static int
 279 tcp_setstopbits(scb, num)
 280      serial_t scb;
 281      int num;
 282 {
 283   return 0;                     /* Never fails! */
 284 }
 285
 286 static int
 287 tcp_write(scb, str, len)
 288      serial_t scb;
 289      const char *str;
 290      int len;
 291 {
 292   int cc;
 293
 294   while (len > 0)
 295     {
 296       cc = write(scb->fd, str, len);
 297
 298       if (cc < 0)
 299         return 1;
 300       len -= cc;
 301       str += cc;
 302     }
 303   return 0;
 304 }
 305
 306 static void
 307 tcp_close(scb)
 308      serial_t scb;
 309 {
 310   if (scb->fd < 0)
 311     return;
 312
 313   close(scb->fd);
 314   scb->fd = -1;
 315 }
 316
 317 static struct serial_ops tcp_ops =
 318 {
 319   "tcp",
 320   0,
 321   tcp_open,
 322   tcp_close,
 323   tcp_readchar,
 324   tcp_write,
 325   tcp_return_0, /* flush output */
 326   tcp_return_0, /* flush input */
 327   tcp_return_0, /* send break */
 328   tcp_raw,
 329   tcp_get_tty_state,
 330   tcp_set_tty_state,
 331   tcp_print_tty_state,
 332   tcp_noflush_set_tty_state,
 333   tcp_setbaudrate,
 334   tcp_setstopbits,
 335 };
 336
 337 void
 338 _initialize_ser_tcp ()
 339 {
 340   serial_add_interface (&tcp_ops);
 341 }