| 1 | /* Serial interface for raw TCP connections on Un*x like systems. |
| 2 | |
| 3 | Copyright (C) 1992-2016 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 | #include <algorithm> |
| 58 | |
| 59 | #ifndef HAVE_SOCKLEN_T |
| 60 | typedef int socklen_t; |
| 61 | #endif |
| 62 | |
| 63 | void _initialize_ser_tcp (void); |
| 64 | |
| 65 | /* For "set tcp" and "show tcp". */ |
| 66 | |
| 67 | static struct cmd_list_element *tcp_set_cmdlist; |
| 68 | static struct cmd_list_element *tcp_show_cmdlist; |
| 69 | |
| 70 | /* Whether to auto-retry refused connections. */ |
| 71 | |
| 72 | static int tcp_auto_retry = 1; |
| 73 | |
| 74 | /* Timeout period for connections, in seconds. */ |
| 75 | |
| 76 | static unsigned int tcp_retry_limit = 15; |
| 77 | |
| 78 | /* How many times per second to poll deprecated_ui_loop_hook. */ |
| 79 | |
| 80 | #define POLL_INTERVAL 5 |
| 81 | |
| 82 | /* Helper function to wait a while. If SCB is non-null, wait on its |
| 83 | file descriptor. Otherwise just wait on a timeout, updating *POLLS. |
| 84 | Returns -1 on timeout or interrupt, otherwise the value of select. */ |
| 85 | |
| 86 | static int |
| 87 | wait_for_connect (struct serial *scb, unsigned int *polls) |
| 88 | { |
| 89 | struct timeval t; |
| 90 | int n; |
| 91 | |
| 92 | /* While we wait for the connect to complete, |
| 93 | poll the UI so it can update or the user can |
| 94 | interrupt. */ |
| 95 | if (deprecated_ui_loop_hook && deprecated_ui_loop_hook (0)) |
| 96 | { |
| 97 | errno = EINTR; |
| 98 | return -1; |
| 99 | } |
| 100 | |
| 101 | /* Check for timeout. */ |
| 102 | if (*polls > tcp_retry_limit * POLL_INTERVAL) |
| 103 | { |
| 104 | errno = ETIMEDOUT; |
| 105 | return -1; |
| 106 | } |
| 107 | |
| 108 | /* Back off to polling once per second after the first POLL_INTERVAL |
| 109 | polls. */ |
| 110 | if (*polls < POLL_INTERVAL) |
| 111 | { |
| 112 | t.tv_sec = 0; |
| 113 | t.tv_usec = 1000000 / POLL_INTERVAL; |
| 114 | } |
| 115 | else |
| 116 | { |
| 117 | t.tv_sec = 1; |
| 118 | t.tv_usec = 0; |
| 119 | } |
| 120 | |
| 121 | if (scb) |
| 122 | { |
| 123 | fd_set rset, wset, eset; |
| 124 | |
| 125 | FD_ZERO (&rset); |
| 126 | FD_SET (scb->fd, &rset); |
| 127 | wset = rset; |
| 128 | eset = rset; |
| 129 | |
| 130 | /* POSIX systems return connection success or failure by signalling |
| 131 | wset. Windows systems return success in wset and failure in |
| 132 | eset. |
| 133 | |
| 134 | We must call select here, rather than gdb_select, because |
| 135 | the serial structure has not yet been initialized - the |
| 136 | MinGW select wrapper will not know that this FD refers |
| 137 | to a socket. */ |
| 138 | n = select (scb->fd + 1, &rset, &wset, &eset, &t); |
| 139 | } |
| 140 | else |
| 141 | /* Use gdb_select here, since we have no file descriptors, and on |
| 142 | Windows, plain select doesn't work in that case. */ |
| 143 | n = gdb_select (0, NULL, NULL, NULL, &t); |
| 144 | |
| 145 | /* If we didn't time out, only count it as one poll. */ |
| 146 | if (n > 0 || *polls < POLL_INTERVAL) |
| 147 | (*polls)++; |
| 148 | else |
| 149 | (*polls) += POLL_INTERVAL; |
| 150 | |
| 151 | return n; |
| 152 | } |
| 153 | |
| 154 | /* Open a tcp socket. */ |
| 155 | |
| 156 | int |
| 157 | net_open (struct serial *scb, const char *name) |
| 158 | { |
| 159 | char hostname[100]; |
| 160 | const char *port_str; |
| 161 | int n, port, tmp; |
| 162 | int use_udp; |
| 163 | struct hostent *hostent; |
| 164 | struct sockaddr_in sockaddr; |
| 165 | #ifdef USE_WIN32API |
| 166 | u_long ioarg; |
| 167 | #else |
| 168 | int ioarg; |
| 169 | #endif |
| 170 | unsigned int polls = 0; |
| 171 | |
| 172 | use_udp = 0; |
| 173 | if (startswith (name, "udp:")) |
| 174 | { |
| 175 | use_udp = 1; |
| 176 | name = name + 4; |
| 177 | } |
| 178 | else if (startswith (name, "tcp:")) |
| 179 | name = name + 4; |
| 180 | |
| 181 | port_str = strchr (name, ':'); |
| 182 | |
| 183 | if (!port_str) |
| 184 | error (_("net_open: No colon in host name!")); /* Shouldn't ever |
| 185 | happen. */ |
| 186 | |
| 187 | tmp = std::min (port_str - name, (ptrdiff_t) sizeof hostname - 1); |
| 188 | strncpy (hostname, name, tmp); /* Don't want colon. */ |
| 189 | hostname[tmp] = '\000'; /* Tie off host name. */ |
| 190 | port = atoi (port_str + 1); |
| 191 | |
| 192 | /* Default hostname is localhost. */ |
| 193 | if (!hostname[0]) |
| 194 | strcpy (hostname, "localhost"); |
| 195 | |
| 196 | hostent = gethostbyname (hostname); |
| 197 | if (!hostent) |
| 198 | { |
| 199 | fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname); |
| 200 | errno = ENOENT; |
| 201 | return -1; |
| 202 | } |
| 203 | |
| 204 | sockaddr.sin_family = PF_INET; |
| 205 | sockaddr.sin_port = htons (port); |
| 206 | memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr, |
| 207 | sizeof (struct in_addr)); |
| 208 | |
| 209 | retry: |
| 210 | |
| 211 | if (use_udp) |
| 212 | scb->fd = gdb_socket_cloexec (PF_INET, SOCK_DGRAM, 0); |
| 213 | else |
| 214 | scb->fd = gdb_socket_cloexec (PF_INET, SOCK_STREAM, 0); |
| 215 | |
| 216 | if (scb->fd == -1) |
| 217 | return -1; |
| 218 | |
| 219 | /* Set socket nonblocking. */ |
| 220 | ioarg = 1; |
| 221 | ioctl (scb->fd, FIONBIO, &ioarg); |
| 222 | |
| 223 | /* Use Non-blocking connect. connect() will return 0 if connected |
| 224 | already. */ |
| 225 | n = connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof (sockaddr)); |
| 226 | |
| 227 | if (n < 0) |
| 228 | { |
| 229 | #ifdef USE_WIN32API |
| 230 | int err = WSAGetLastError(); |
| 231 | #else |
| 232 | int err = errno; |
| 233 | #endif |
| 234 | |
| 235 | /* Maybe we're waiting for the remote target to become ready to |
| 236 | accept connections. */ |
| 237 | if (tcp_auto_retry |
| 238 | #ifdef USE_WIN32API |
| 239 | && err == WSAECONNREFUSED |
| 240 | #else |
| 241 | && err == ECONNREFUSED |
| 242 | #endif |
| 243 | && wait_for_connect (NULL, &polls) >= 0) |
| 244 | { |
| 245 | close (scb->fd); |
| 246 | goto retry; |
| 247 | } |
| 248 | |
| 249 | if ( |
| 250 | #ifdef USE_WIN32API |
| 251 | /* Under Windows, calling "connect" with a non-blocking socket |
| 252 | results in WSAEWOULDBLOCK, not WSAEINPROGRESS. */ |
| 253 | err != WSAEWOULDBLOCK |
| 254 | #else |
| 255 | err != EINPROGRESS |
| 256 | #endif |
| 257 | ) |
| 258 | { |
| 259 | errno = err; |
| 260 | net_close (scb); |
| 261 | return -1; |
| 262 | } |
| 263 | |
| 264 | /* Looks like we need to wait for the connect. */ |
| 265 | do |
| 266 | { |
| 267 | n = wait_for_connect (scb, &polls); |
| 268 | } |
| 269 | while (n == 0); |
| 270 | if (n < 0) |
| 271 | { |
| 272 | net_close (scb); |
| 273 | return -1; |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | /* Got something. Is it an error? */ |
| 278 | { |
| 279 | int res, err; |
| 280 | socklen_t len; |
| 281 | |
| 282 | len = sizeof (err); |
| 283 | /* On Windows, the fourth parameter to getsockopt is a "char *"; |
| 284 | on UNIX systems it is generally "void *". The cast to "char *" |
| 285 | is OK everywhere, since in C++ any data pointer type can be |
| 286 | implicitly converted to "void *". */ |
| 287 | res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, (char *) &err, &len); |
| 288 | if (res < 0 || err) |
| 289 | { |
| 290 | /* Maybe the target still isn't ready to accept the connection. */ |
| 291 | if (tcp_auto_retry |
| 292 | #ifdef USE_WIN32API |
| 293 | && err == WSAECONNREFUSED |
| 294 | #else |
| 295 | && err == ECONNREFUSED |
| 296 | #endif |
| 297 | && wait_for_connect (NULL, &polls) >= 0) |
| 298 | { |
| 299 | close (scb->fd); |
| 300 | goto retry; |
| 301 | } |
| 302 | if (err) |
| 303 | errno = err; |
| 304 | net_close (scb); |
| 305 | return -1; |
| 306 | } |
| 307 | } |
| 308 | |
| 309 | /* Turn off nonblocking. */ |
| 310 | ioarg = 0; |
| 311 | ioctl (scb->fd, FIONBIO, &ioarg); |
| 312 | |
| 313 | if (use_udp == 0) |
| 314 | { |
| 315 | /* Disable Nagle algorithm. Needed in some cases. */ |
| 316 | tmp = 1; |
| 317 | setsockopt (scb->fd, IPPROTO_TCP, TCP_NODELAY, |
| 318 | (char *)&tmp, sizeof (tmp)); |
| 319 | } |
| 320 | |
| 321 | #ifdef SIGPIPE |
| 322 | /* If we don't do this, then GDB simply exits |
| 323 | when the remote side dies. */ |
| 324 | signal (SIGPIPE, SIG_IGN); |
| 325 | #endif |
| 326 | |
| 327 | return 0; |
| 328 | } |
| 329 | |
| 330 | void |
| 331 | net_close (struct serial *scb) |
| 332 | { |
| 333 | if (scb->fd == -1) |
| 334 | return; |
| 335 | |
| 336 | close (scb->fd); |
| 337 | scb->fd = -1; |
| 338 | } |
| 339 | |
| 340 | int |
| 341 | net_read_prim (struct serial *scb, size_t count) |
| 342 | { |
| 343 | /* Need to cast to silence -Wpointer-sign on MinGW, as Winsock's |
| 344 | 'recv' takes 'char *' as second argument, while 'scb->buf' is |
| 345 | 'unsigned char *'. */ |
| 346 | return recv (scb->fd, (char *) scb->buf, count, 0); |
| 347 | } |
| 348 | |
| 349 | int |
| 350 | net_write_prim (struct serial *scb, const void *buf, size_t count) |
| 351 | { |
| 352 | /* On Windows, the second parameter to send is a "const char *"; on |
| 353 | UNIX systems it is generally "const void *". The cast to "const |
| 354 | char *" is OK everywhere, since in C++ any data pointer type can |
| 355 | be implicitly converted to "const void *". */ |
| 356 | return send (scb->fd, (const char *) buf, count, 0); |
| 357 | } |
| 358 | |
| 359 | int |
| 360 | ser_tcp_send_break (struct serial *scb) |
| 361 | { |
| 362 | /* Send telnet IAC and BREAK characters. */ |
| 363 | return (serial_write (scb, "\377\363", 2)); |
| 364 | } |
| 365 | |
| 366 | /* Support for "set tcp" and "show tcp" commands. */ |
| 367 | |
| 368 | static void |
| 369 | set_tcp_cmd (char *args, int from_tty) |
| 370 | { |
| 371 | help_list (tcp_set_cmdlist, "set tcp ", all_commands, gdb_stdout); |
| 372 | } |
| 373 | |
| 374 | static void |
| 375 | show_tcp_cmd (char *args, int from_tty) |
| 376 | { |
| 377 | help_list (tcp_show_cmdlist, "show tcp ", all_commands, gdb_stdout); |
| 378 | } |
| 379 | |
| 380 | #ifndef USE_WIN32API |
| 381 | |
| 382 | /* The TCP ops. */ |
| 383 | |
| 384 | static const struct serial_ops tcp_ops = |
| 385 | { |
| 386 | "tcp", |
| 387 | net_open, |
| 388 | net_close, |
| 389 | NULL, |
| 390 | ser_base_readchar, |
| 391 | ser_base_write, |
| 392 | ser_base_flush_output, |
| 393 | ser_base_flush_input, |
| 394 | ser_tcp_send_break, |
| 395 | ser_base_raw, |
| 396 | ser_base_get_tty_state, |
| 397 | ser_base_copy_tty_state, |
| 398 | ser_base_set_tty_state, |
| 399 | ser_base_print_tty_state, |
| 400 | ser_base_noflush_set_tty_state, |
| 401 | ser_base_setbaudrate, |
| 402 | ser_base_setstopbits, |
| 403 | ser_base_setparity, |
| 404 | ser_base_drain_output, |
| 405 | ser_base_async, |
| 406 | net_read_prim, |
| 407 | net_write_prim |
| 408 | }; |
| 409 | |
| 410 | #endif /* USE_WIN32API */ |
| 411 | |
| 412 | void |
| 413 | _initialize_ser_tcp (void) |
| 414 | { |
| 415 | #ifdef USE_WIN32API |
| 416 | /* Do nothing; the TCP serial operations will be initialized in |
| 417 | ser-mingw.c. */ |
| 418 | #else |
| 419 | serial_add_interface (&tcp_ops); |
| 420 | #endif /* USE_WIN32API */ |
| 421 | |
| 422 | add_prefix_cmd ("tcp", class_maintenance, set_tcp_cmd, _("\ |
| 423 | TCP protocol specific variables\n\ |
| 424 | Configure variables specific to remote TCP connections"), |
| 425 | &tcp_set_cmdlist, "set tcp ", |
| 426 | 0 /* allow-unknown */, &setlist); |
| 427 | add_prefix_cmd ("tcp", class_maintenance, show_tcp_cmd, _("\ |
| 428 | TCP protocol specific variables\n\ |
| 429 | Configure variables specific to remote TCP connections"), |
| 430 | &tcp_show_cmdlist, "show tcp ", |
| 431 | 0 /* allow-unknown */, &showlist); |
| 432 | |
| 433 | add_setshow_boolean_cmd ("auto-retry", class_obscure, |
| 434 | &tcp_auto_retry, _("\ |
| 435 | Set auto-retry on socket connect"), _("\ |
| 436 | Show auto-retry on socket connect"), |
| 437 | NULL, NULL, NULL, |
| 438 | &tcp_set_cmdlist, &tcp_show_cmdlist); |
| 439 | |
| 440 | add_setshow_uinteger_cmd ("connect-timeout", class_obscure, |
| 441 | &tcp_retry_limit, _("\ |
| 442 | Set timeout limit in seconds for socket connection"), _("\ |
| 443 | Show timeout limit in seconds for socket connection"), _("\ |
| 444 | If set to \"unlimited\", GDB will keep attempting to establish a\n\ |
| 445 | connection forever, unless interrupted with Ctrl-c.\n\ |
| 446 | The default is 15 seconds."), |
| 447 | NULL, NULL, |
| 448 | &tcp_set_cmdlist, &tcp_show_cmdlist); |
| 449 | } |