| 1 | /* Serial interface for raw TCP connections on Un*x like systems. |
| 2 | |
| 3 | Copyright (C) 1992-2015 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 | #include "filestuff.h" |
| 28 | |
| 29 | #include <sys/types.h> |
| 30 | |
| 31 | #ifdef HAVE_SYS_FILIO_H |
| 32 | #include <sys/filio.h> /* For FIONBIO. */ |
| 33 | #endif |
| 34 | #ifdef HAVE_SYS_IOCTL_H |
| 35 | #include <sys/ioctl.h> /* For FIONBIO. */ |
| 36 | #endif |
| 37 | |
| 38 | #include "gdb_sys_time.h" |
| 39 | |
| 40 | #ifdef USE_WIN32API |
| 41 | #include <winsock2.h> |
| 42 | #ifndef ETIMEDOUT |
| 43 | #define ETIMEDOUT WSAETIMEDOUT |
| 44 | #endif |
| 45 | #define close(fd) closesocket (fd) |
| 46 | #define ioctl ioctlsocket |
| 47 | #else |
| 48 | #include <netinet/in.h> |
| 49 | #include <arpa/inet.h> |
| 50 | #include <netdb.h> |
| 51 | #include <sys/socket.h> |
| 52 | #include <netinet/tcp.h> |
| 53 | #endif |
| 54 | |
| 55 | #include <signal.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, unsigned 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 | unsigned int polls = 0; |
| 169 | |
| 170 | use_udp = 0; |
| 171 | if (startswith (name, "udp:")) |
| 172 | { |
| 173 | use_udp = 1; |
| 174 | name = name + 4; |
| 175 | } |
| 176 | else if (startswith (name, "tcp:")) |
| 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 = gdb_socket_cloexec (PF_INET, SOCK_DGRAM, 0); |
| 211 | else |
| 212 | scb->fd = gdb_socket_cloexec (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 | /* Need to cast to silence -Wpointer-sign on MinGW, as Winsock's |
| 342 | 'recv' takes 'char *' as second argument, while 'scb->buf' is |
| 343 | 'unsigned char *'. */ |
| 344 | return recv (scb->fd, (void *) scb->buf, count, 0); |
| 345 | } |
| 346 | |
| 347 | int |
| 348 | net_write_prim (struct serial *scb, const void *buf, size_t count) |
| 349 | { |
| 350 | return send (scb->fd, buf, count, 0); |
| 351 | } |
| 352 | |
| 353 | int |
| 354 | ser_tcp_send_break (struct serial *scb) |
| 355 | { |
| 356 | /* Send telnet IAC and BREAK characters. */ |
| 357 | return (serial_write (scb, "\377\363", 2)); |
| 358 | } |
| 359 | |
| 360 | /* Support for "set tcp" and "show tcp" commands. */ |
| 361 | |
| 362 | static void |
| 363 | set_tcp_cmd (char *args, int from_tty) |
| 364 | { |
| 365 | help_list (tcp_set_cmdlist, "set tcp ", all_commands, gdb_stdout); |
| 366 | } |
| 367 | |
| 368 | static void |
| 369 | show_tcp_cmd (char *args, int from_tty) |
| 370 | { |
| 371 | help_list (tcp_show_cmdlist, "show tcp ", all_commands, gdb_stdout); |
| 372 | } |
| 373 | |
| 374 | #ifndef USE_WIN32API |
| 375 | |
| 376 | /* The TCP ops. */ |
| 377 | |
| 378 | static const struct serial_ops tcp_ops = |
| 379 | { |
| 380 | "tcp", |
| 381 | net_open, |
| 382 | net_close, |
| 383 | NULL, |
| 384 | ser_base_readchar, |
| 385 | ser_base_write, |
| 386 | ser_base_flush_output, |
| 387 | ser_base_flush_input, |
| 388 | ser_tcp_send_break, |
| 389 | ser_base_raw, |
| 390 | ser_base_get_tty_state, |
| 391 | ser_base_copy_tty_state, |
| 392 | ser_base_set_tty_state, |
| 393 | ser_base_print_tty_state, |
| 394 | ser_base_noflush_set_tty_state, |
| 395 | ser_base_setbaudrate, |
| 396 | ser_base_setstopbits, |
| 397 | ser_base_setparity, |
| 398 | ser_base_drain_output, |
| 399 | ser_base_async, |
| 400 | net_read_prim, |
| 401 | net_write_prim |
| 402 | }; |
| 403 | |
| 404 | #endif /* USE_WIN32API */ |
| 405 | |
| 406 | void |
| 407 | _initialize_ser_tcp (void) |
| 408 | { |
| 409 | #ifdef USE_WIN32API |
| 410 | /* Do nothing; the TCP serial operations will be initialized in |
| 411 | ser-mingw.c. */ |
| 412 | #else |
| 413 | serial_add_interface (&tcp_ops); |
| 414 | #endif /* USE_WIN32API */ |
| 415 | |
| 416 | add_prefix_cmd ("tcp", class_maintenance, set_tcp_cmd, _("\ |
| 417 | TCP protocol specific variables\n\ |
| 418 | Configure variables specific to remote TCP connections"), |
| 419 | &tcp_set_cmdlist, "set tcp ", |
| 420 | 0 /* allow-unknown */, &setlist); |
| 421 | add_prefix_cmd ("tcp", class_maintenance, show_tcp_cmd, _("\ |
| 422 | TCP protocol specific variables\n\ |
| 423 | Configure variables specific to remote TCP connections"), |
| 424 | &tcp_show_cmdlist, "show tcp ", |
| 425 | 0 /* allow-unknown */, &showlist); |
| 426 | |
| 427 | add_setshow_boolean_cmd ("auto-retry", class_obscure, |
| 428 | &tcp_auto_retry, _("\ |
| 429 | Set auto-retry on socket connect"), _("\ |
| 430 | Show auto-retry on socket connect"), |
| 431 | NULL, NULL, NULL, |
| 432 | &tcp_set_cmdlist, &tcp_show_cmdlist); |
| 433 | |
| 434 | add_setshow_uinteger_cmd ("connect-timeout", class_obscure, |
| 435 | &tcp_retry_limit, _("\ |
| 436 | Set timeout limit in seconds for socket connection"), _("\ |
| 437 | Show timeout limit in seconds for socket connection"), _("\ |
| 438 | If set to \"unlimited\", GDB will keep attempting to establish a\n\ |
| 439 | connection forever, unless interrupted with Ctrl-c.\n\ |
| 440 | The default is 15 seconds."), |
| 441 | NULL, NULL, |
| 442 | &tcp_set_cmdlist, &tcp_show_cmdlist); |
| 443 | } |