1 /* Serial interface for raw TCP connections on Un*x like systems. 2 3 Copyright (C) 1992-2013 Free Software Foundation, Inc. 4 5 This file is part of GDB. 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 #include "defs.h" 21 #include "serial.h" 22 #include "ser-base.h" 23 #include "ser-tcp.h" 24 #include "gdbcmd.h" 25 #include "cli/cli-decode.h" 26 #include "cli/cli-setshow.h" 27 28 #include <sys/types.h> 29 30 #ifdef HAVE_SYS_FILIO_H 31 #include <sys/filio.h> /* For FIONBIO. */ 32 #endif 33 #ifdef HAVE_SYS_IOCTL_H 34 #include <sys/ioctl.h> /* For FIONBIO. */ 35 #endif 36 37 #include <sys/time.h> 38 39 #ifdef USE_WIN32API 40 #include <winsock2.h> 41 #ifndef ETIMEDOUT 42 #define ETIMEDOUT WSAETIMEDOUT 43 #endif 44 #define close(fd) closesocket (fd) 45 #define ioctl ioctlsocket 46 #else 47 #include <netinet/in.h> 48 #include <arpa/inet.h> 49 #include <netdb.h> 50 #include <sys/socket.h> 51 #include <netinet/tcp.h> 52 #endif 53 54 #include <signal.h> 55 #include "gdb_string.h" 56 #include "gdb_select.h" 57 58 #ifndef HAVE_SOCKLEN_T 59 typedef int socklen_t; 60 #endif 61 62 void _initialize_ser_tcp (void); 63 64 /* For "set tcp" and "show tcp". */ 65 66 static struct cmd_list_element *tcp_set_cmdlist; 67 static struct cmd_list_element *tcp_show_cmdlist; 68 69 /* Whether to auto-retry refused connections. */ 70 71 static int tcp_auto_retry = 1; 72 73 /* Timeout period for connections, in seconds. */ 74 75 static unsigned int tcp_retry_limit = 15; 76 77 /* How many times per second to poll deprecated_ui_loop_hook. */ 78 79 #define POLL_INTERVAL 5 80 81 /* Helper function to wait a while. If SCB is non-null, wait on its 82 file descriptor. Otherwise just wait on a timeout, updating *POLLS. 83 Returns -1 on timeout or interrupt, otherwise the value of select. */ 84 85 static int 86 wait_for_connect (struct serial *scb, int *polls) 87 { 88 struct timeval t; 89 int n; 90 91 /* While we wait for the connect to complete, 92 poll the UI so it can update or the user can 93 interrupt. */ 94 if (deprecated_ui_loop_hook && deprecated_ui_loop_hook (0)) 95 { 96 errno = EINTR; 97 return -1; 98 } 99 100 /* Check for timeout. */ 101 if (*polls > tcp_retry_limit * POLL_INTERVAL) 102 { 103 errno = ETIMEDOUT; 104 return -1; 105 } 106 107 /* Back off to polling once per second after the first POLL_INTERVAL 108 polls. */ 109 if (*polls < POLL_INTERVAL) 110 { 111 t.tv_sec = 0; 112 t.tv_usec = 1000000 / POLL_INTERVAL; 113 } 114 else 115 { 116 t.tv_sec = 1; 117 t.tv_usec = 0; 118 } 119 120 if (scb) 121 { 122 fd_set rset, wset, eset; 123 124 FD_ZERO (&rset); 125 FD_SET (scb->fd, &rset); 126 wset = rset; 127 eset = rset; 128 129 /* POSIX systems return connection success or failure by signalling 130 wset. Windows systems return success in wset and failure in 131 eset. 132 133 We must call select here, rather than gdb_select, because 134 the serial structure has not yet been initialized - the 135 MinGW select wrapper will not know that this FD refers 136 to a socket. */ 137 n = select (scb->fd + 1, &rset, &wset, &eset, &t); 138 } 139 else 140 /* Use gdb_select here, since we have no file descriptors, and on 141 Windows, plain select doesn't work in that case. */ 142 n = gdb_select (0, NULL, NULL, NULL, &t); 143 144 /* If we didn't time out, only count it as one poll. */ 145 if (n > 0 || *polls < POLL_INTERVAL) 146 (*polls)++; 147 else 148 (*polls) += POLL_INTERVAL; 149 150 return n; 151 } 152 153 /* Open a tcp socket. */ 154 155 int 156 net_open (struct serial *scb, const char *name) 157 { 158 char *port_str, hostname[100]; 159 int n, port, tmp; 160 int use_udp; 161 struct hostent *hostent; 162 struct sockaddr_in sockaddr; 163 #ifdef USE_WIN32API 164 u_long ioarg; 165 #else 166 int ioarg; 167 #endif 168 int polls = 0; 169 170 use_udp = 0; 171 if (strncmp (name, "udp:", 4) == 0) 172 { 173 use_udp = 1; 174 name = name + 4; 175 } 176 else if (strncmp (name, "tcp:", 4) == 0) 177 name = name + 4; 178 179 port_str = strchr (name, ':'); 180 181 if (!port_str) 182 error (_("net_open: No colon in host name!")); /* Shouldn't ever 183 happen. */ 184 185 tmp = min (port_str - name, (int) sizeof hostname - 1); 186 strncpy (hostname, name, tmp); /* Don't want colon. */ 187 hostname[tmp] = '\000'; /* Tie off host name. */ 188 port = atoi (port_str + 1); 189 190 /* Default hostname is localhost. */ 191 if (!hostname[0]) 192 strcpy (hostname, "localhost"); 193 194 hostent = gethostbyname (hostname); 195 if (!hostent) 196 { 197 fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname); 198 errno = ENOENT; 199 return -1; 200 } 201 202 sockaddr.sin_family = PF_INET; 203 sockaddr.sin_port = htons (port); 204 memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr, 205 sizeof (struct in_addr)); 206 207 retry: 208 209 if (use_udp) 210 scb->fd = socket (PF_INET, SOCK_DGRAM, 0); 211 else 212 scb->fd = socket (PF_INET, SOCK_STREAM, 0); 213 214 if (scb->fd == -1) 215 return -1; 216 217 /* Set socket nonblocking. */ 218 ioarg = 1; 219 ioctl (scb->fd, FIONBIO, &ioarg); 220 221 /* Use Non-blocking connect. connect() will return 0 if connected 222 already. */ 223 n = connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof (sockaddr)); 224 225 if (n < 0) 226 { 227 #ifdef USE_WIN32API 228 int err = WSAGetLastError(); 229 #else 230 int err = errno; 231 #endif 232 233 /* Maybe we're waiting for the remote target to become ready to 234 accept connections. */ 235 if (tcp_auto_retry 236 #ifdef USE_WIN32API 237 && err == WSAECONNREFUSED 238 #else 239 && err == ECONNREFUSED 240 #endif 241 && wait_for_connect (NULL, &polls) >= 0) 242 { 243 close (scb->fd); 244 goto retry; 245 } 246 247 if ( 248 #ifdef USE_WIN32API 249 /* Under Windows, calling "connect" with a non-blocking socket 250 results in WSAEWOULDBLOCK, not WSAEINPROGRESS. */ 251 err != WSAEWOULDBLOCK 252 #else 253 err != EINPROGRESS 254 #endif 255 ) 256 { 257 errno = err; 258 net_close (scb); 259 return -1; 260 } 261 262 /* Looks like we need to wait for the connect. */ 263 do 264 { 265 n = wait_for_connect (scb, &polls); 266 } 267 while (n == 0); 268 if (n < 0) 269 { 270 net_close (scb); 271 return -1; 272 } 273 } 274 275 /* Got something. Is it an error? */ 276 { 277 int res, err; 278 socklen_t len; 279 280 len = sizeof (err); 281 /* On Windows, the fourth parameter to getsockopt is a "char *"; 282 on UNIX systems it is generally "void *". The cast to "void *" 283 is OK everywhere, since in C "void *" can be implicitly 284 converted to any pointer type. */ 285 res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, (void *) &err, &len); 286 if (res < 0 || err) 287 { 288 /* Maybe the target still isn't ready to accept the connection. */ 289 if (tcp_auto_retry 290 #ifdef USE_WIN32API 291 && err == WSAECONNREFUSED 292 #else 293 && err == ECONNREFUSED 294 #endif 295 && wait_for_connect (NULL, &polls) >= 0) 296 { 297 close (scb->fd); 298 goto retry; 299 } 300 if (err) 301 errno = err; 302 net_close (scb); 303 return -1; 304 } 305 } 306 307 /* Turn off nonblocking. */ 308 ioarg = 0; 309 ioctl (scb->fd, FIONBIO, &ioarg); 310 311 if (use_udp == 0) 312 { 313 /* Disable Nagle algorithm. Needed in some cases. */ 314 tmp = 1; 315 setsockopt (scb->fd, IPPROTO_TCP, TCP_NODELAY, 316 (char *)&tmp, sizeof (tmp)); 317 } 318 319 #ifdef SIGPIPE 320 /* If we don't do this, then GDB simply exits 321 when the remote side dies. */ 322 signal (SIGPIPE, SIG_IGN); 323 #endif 324 325 return 0; 326 } 327 328 void 329 net_close (struct serial *scb) 330 { 331 if (scb->fd == -1) 332 return; 333 334 close (scb->fd); 335 scb->fd = -1; 336 } 337 338 int 339 net_read_prim (struct serial *scb, size_t count) 340 { 341 return recv (scb->fd, scb->buf, count, 0); 342 } 343 344 int 345 net_write_prim (struct serial *scb, const void *buf, size_t count) 346 { 347 return send (scb->fd, buf, count, 0); 348 } 349 350 int 351 ser_tcp_send_break (struct serial *scb) 352 { 353 /* Send telnet IAC and BREAK characters. */ 354 return (serial_write (scb, "\377\363", 2)); 355 } 356 357 /* Support for "set tcp" and "show tcp" commands. */ 358 359 static void 360 set_tcp_cmd (char *args, int from_tty) 361 { 362 help_list (tcp_set_cmdlist, "set tcp ", -1, gdb_stdout); 363 } 364 365 static void 366 show_tcp_cmd (char *args, int from_tty) 367 { 368 help_list (tcp_show_cmdlist, "show tcp ", -1, gdb_stdout); 369 } 370 371 372 void 373 _initialize_ser_tcp (void) 374 { 375 #ifdef USE_WIN32API 376 /* Do nothing; the TCP serial operations will be initialized in 377 ser-mingw.c. */ 378 #else 379 struct serial_ops *ops; 380 381 ops = XMALLOC (struct serial_ops); 382 memset (ops, 0, sizeof (struct serial_ops)); 383 ops->name = "tcp"; 384 ops->next = 0; 385 ops->open = net_open; 386 ops->close = net_close; 387 ops->readchar = ser_base_readchar; 388 ops->write = ser_base_write; 389 ops->flush_output = ser_base_flush_output; 390 ops->flush_input = ser_base_flush_input; 391 ops->send_break = ser_tcp_send_break; 392 ops->go_raw = ser_base_raw; 393 ops->get_tty_state = ser_base_get_tty_state; 394 ops->copy_tty_state = ser_base_copy_tty_state; 395 ops->set_tty_state = ser_base_set_tty_state; 396 ops->print_tty_state = ser_base_print_tty_state; 397 ops->noflush_set_tty_state = ser_base_noflush_set_tty_state; 398 ops->setbaudrate = ser_base_setbaudrate; 399 ops->setstopbits = ser_base_setstopbits; 400 ops->drain_output = ser_base_drain_output; 401 ops->async = ser_base_async; 402 ops->read_prim = net_read_prim; 403 ops->write_prim = net_write_prim; 404 serial_add_interface (ops); 405 #endif /* USE_WIN32API */ 406 407 add_prefix_cmd ("tcp", class_maintenance, set_tcp_cmd, _("\ 408 TCP protocol specific variables\n\ 409 Configure variables specific to remote TCP connections"), 410 &tcp_set_cmdlist, "set tcp ", 411 0 /* allow-unknown */, &setlist); 412 add_prefix_cmd ("tcp", class_maintenance, show_tcp_cmd, _("\ 413 TCP protocol specific variables\n\ 414 Configure variables specific to remote TCP connections"), 415 &tcp_show_cmdlist, "show tcp ", 416 0 /* allow-unknown */, &showlist); 417 418 add_setshow_boolean_cmd ("auto-retry", class_obscure, 419 &tcp_auto_retry, _("\ 420 Set auto-retry on socket connect"), _("\ 421 Show auto-retry on socket connect"), 422 NULL, NULL, NULL, 423 &tcp_set_cmdlist, &tcp_show_cmdlist); 424 425 add_setshow_uinteger_cmd ("connect-timeout", class_obscure, 426 &tcp_retry_limit, _("\ 427 Set timeout limit for socket connection"), _("\ 428 Show timeout limit for socket connection"), 429 NULL, NULL, NULL, 430 &tcp_set_cmdlist, &tcp_show_cmdlist); 431 } 432