1 /* Serial interface for raw TCP connections on Un*x like systems.
3 Copyright (C) 1992-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
25 #include "cli/cli-decode.h"
26 #include "cli/cli-setshow.h"
27 #include "filestuff.h"
30 #include <sys/types.h>
32 #ifdef HAVE_SYS_FILIO_H
33 #include <sys/filio.h> /* For FIONBIO. */
35 #ifdef HAVE_SYS_IOCTL_H
36 #include <sys/ioctl.h> /* For FIONBIO. */
39 #include "gdb_sys_time.h"
45 #define ETIMEDOUT WSAETIMEDOUT
47 /* Gnulib defines close too, but gnulib's replacement
48 doesn't call closesocket unless we import the
51 #define close(fd) closesocket (fd)
52 #define ioctl ioctlsocket
54 #include <netinet/in.h>
55 #include <arpa/inet.h>
57 #include <sys/socket.h>
58 #include <netinet/tcp.h>
62 #include "gdb_select.h"
65 #ifndef HAVE_SOCKLEN_T
66 typedef int socklen_t
;
69 /* For "set tcp" and "show tcp". */
71 static struct cmd_list_element
*tcp_set_cmdlist
;
72 static struct cmd_list_element
*tcp_show_cmdlist
;
74 /* Whether to auto-retry refused connections. */
76 static int tcp_auto_retry
= 1;
78 /* Timeout period for connections, in seconds. */
80 static unsigned int tcp_retry_limit
= 15;
82 /* How many times per second to poll deprecated_ui_loop_hook. */
84 #define POLL_INTERVAL 5
86 /* Helper function to wait a while. If SOCK is not -1, wait on its
87 file descriptor. Otherwise just wait on a timeout, updating
88 *POLLS. Returns -1 on timeout or interrupt, otherwise the value of
92 wait_for_connect (int sock
, unsigned int *polls
)
97 /* While we wait for the connect to complete,
98 poll the UI so it can update or the user can
100 if (deprecated_ui_loop_hook
&& deprecated_ui_loop_hook (0))
106 /* Check for timeout. */
107 if (*polls
> tcp_retry_limit
* POLL_INTERVAL
)
113 /* Back off to polling once per second after the first POLL_INTERVAL
115 if (*polls
< POLL_INTERVAL
)
118 t
.tv_usec
= 1000000 / POLL_INTERVAL
;
128 fd_set rset
, wset
, eset
;
131 FD_SET (sock
, &rset
);
135 /* POSIX systems return connection success or failure by signalling
136 wset. Windows systems return success in wset and failure in
139 We must call select here, rather than gdb_select, because
140 the serial structure has not yet been initialized - the
141 MinGW select wrapper will not know that this FD refers
143 n
= select (sock
+ 1, &rset
, &wset
, &eset
, &t
);
146 /* Use gdb_select here, since we have no file descriptors, and on
147 Windows, plain select doesn't work in that case. */
148 n
= gdb_select (0, NULL
, NULL
, NULL
, &t
);
150 /* If we didn't time out, only count it as one poll. */
151 if (n
> 0 || *polls
< POLL_INTERVAL
)
154 (*polls
) += POLL_INTERVAL
;
159 /* Try to connect to the host represented by AINFO. If the connection
160 succeeds, return its socket. Otherwise, return -1 and set ERRNO
161 accordingly. POLLS is used when 'connect' returns EINPROGRESS, and
162 we need to invoke 'wait_for_connect' to obtain the status. */
165 try_connect (const struct addrinfo
*ainfo
, unsigned int *polls
)
167 int sock
= gdb_socket_cloexec (ainfo
->ai_family
, ainfo
->ai_socktype
,
173 /* Set socket nonblocking. */
176 ioctl (sock
, FIONBIO
, &ioarg
);
178 /* Use Non-blocking connect. connect() will return 0 if connected
180 if (connect (sock
, ainfo
->ai_addr
, ainfo
->ai_addrlen
) < 0)
183 int err
= WSAGetLastError();
188 /* If we've got a "connection refused" error, just return
189 -1. The caller will know what to do. */
192 err
== WSAECONNREFUSED
204 /* Any other error (except EINPROGRESS) will be "swallowed"
205 here. We return without specifying a return value, and
206 set errno if the caller wants to inspect what
209 /* Under Windows, calling "connect" with a non-blocking socket
210 results in WSAEWOULDBLOCK, not WSAEINPROGRESS. */
211 err
!= WSAEWOULDBLOCK
222 /* Looks like we need to wait for the connect. */
226 n
= wait_for_connect (sock
, polls
);
231 int saved_errno
= errno
;
233 /* A negative value here means that we either timed out or
234 got interrupted by the user. Just return. */
241 /* Got something. Is it an error? */
243 socklen_t len
= sizeof (err
);
245 /* On Windows, the fourth parameter to getsockopt is a "char *";
246 on UNIX systems it is generally "void *". The cast to "char *"
247 is OK everywhere, since in C++ any data pointer type can be
248 implicitly converted to "void *". */
249 int ret
= getsockopt (sock
, SOL_SOCKET
, SO_ERROR
, (char *) &err
, &len
);
253 int saved_errno
= errno
;
259 else if (ret
== 0 && err
!= 0)
266 /* The connection succeeded. Return the socket. */
270 /* Open a tcp socket. */
273 net_open (struct serial
*scb
, const char *name
)
275 struct addrinfo hint
;
276 struct addrinfo
*ainfo
;
278 memset (&hint
, 0, sizeof (hint
));
279 /* Assume no prefix will be passed, therefore we should use
281 hint
.ai_family
= AF_UNSPEC
;
282 hint
.ai_socktype
= SOCK_STREAM
;
283 hint
.ai_protocol
= IPPROTO_TCP
;
285 parsed_connection_spec parsed
= parse_connection_spec (name
, &hint
);
287 if (parsed
.port_str
.empty ())
288 error (_("Missing port on hostname '%s'"), name
);
290 int r
= getaddrinfo (parsed
.host_str
.c_str (),
291 parsed
.port_str
.c_str (),
296 fprintf_unfiltered (gdb_stderr
, _("%s: cannot resolve name: %s\n"),
297 name
, gai_strerror (r
));
302 scoped_free_addrinfo
free_ainfo (ainfo
);
304 /* Flag to indicate whether we've got a connection refused. It will
305 be true if any of the connections tried was refused. */
306 bool got_connrefused
;
307 /* If a connection succeeeds, SUCCESS_AINFO will point to the
308 'struct addrinfo' that succeed. */
309 struct addrinfo
*success_ainfo
= NULL
;
310 unsigned int polls
= 0;
312 /* Assume the worst. */
317 got_connrefused
= false;
319 for (struct addrinfo
*iter
= ainfo
; iter
!= NULL
; iter
= iter
->ai_next
)
321 /* Iterate over the list of possible addresses to connect
322 to. For each, we'll try to connect and see if it
324 int sock
= try_connect (iter
, &polls
);
328 /* We've gotten a successful connection. Save its
329 'struct addrinfo', the socket, and break. */
330 success_ainfo
= iter
;
336 errno
== WSAECONNREFUSED
338 errno
== ECONNREFUSED
341 got_connrefused
= true;
346 - tcp_auto_retry is true, and
347 - We haven't gotten a connection yet, and
348 - Any of our connection attempts returned with ECONNREFUSED, and
349 - wait_for_connect signals that we can keep going. */
350 while (tcp_auto_retry
351 && success_ainfo
== NULL
353 && wait_for_connect (-1, &polls
) >= 0);
355 if (success_ainfo
== NULL
)
361 /* Turn off nonblocking. */
368 ioctl (scb
->fd
, FIONBIO
, &ioarg
);
370 if (success_ainfo
->ai_socktype
== IPPROTO_TCP
)
372 /* Disable Nagle algorithm. Needed in some cases. */
375 setsockopt (scb
->fd
, IPPROTO_TCP
, TCP_NODELAY
,
376 (char *) &tmp
, sizeof (tmp
));
380 /* If we don't do this, then GDB simply exits
381 when the remote side dies. */
382 signal (SIGPIPE
, SIG_IGN
);
389 net_close (struct serial
*scb
)
399 net_read_prim (struct serial
*scb
, size_t count
)
401 /* Need to cast to silence -Wpointer-sign on MinGW, as Winsock's
402 'recv' takes 'char *' as second argument, while 'scb->buf' is
403 'unsigned char *'. */
404 return recv (scb
->fd
, (char *) scb
->buf
, count
, 0);
408 net_write_prim (struct serial
*scb
, const void *buf
, size_t count
)
410 /* On Windows, the second parameter to send is a "const char *"; on
411 UNIX systems it is generally "const void *". The cast to "const
412 char *" is OK everywhere, since in C++ any data pointer type can
413 be implicitly converted to "const void *". */
414 return send (scb
->fd
, (const char *) buf
, count
, 0);
418 ser_tcp_send_break (struct serial
*scb
)
420 /* Send telnet IAC and BREAK characters. */
421 return (serial_write (scb
, "\377\363", 2));
424 /* Support for "set tcp" and "show tcp" commands. */
427 set_tcp_cmd (const char *args
, int from_tty
)
429 help_list (tcp_set_cmdlist
, "set tcp ", all_commands
, gdb_stdout
);
433 show_tcp_cmd (const char *args
, int from_tty
)
435 help_list (tcp_show_cmdlist
, "show tcp ", all_commands
, gdb_stdout
);
442 static const struct serial_ops tcp_ops
=
450 ser_base_flush_output
,
451 ser_base_flush_input
,
454 ser_base_get_tty_state
,
455 ser_base_copy_tty_state
,
456 ser_base_set_tty_state
,
457 ser_base_print_tty_state
,
458 ser_base_setbaudrate
,
459 ser_base_setstopbits
,
461 ser_base_drain_output
,
467 #endif /* USE_WIN32API */
470 _initialize_ser_tcp (void)
473 /* Do nothing; the TCP serial operations will be initialized in
476 serial_add_interface (&tcp_ops
);
477 #endif /* USE_WIN32API */
479 add_prefix_cmd ("tcp", class_maintenance
, set_tcp_cmd
, _("\
480 TCP protocol specific variables\n\
481 Configure variables specific to remote TCP connections"),
482 &tcp_set_cmdlist
, "set tcp ",
483 0 /* allow-unknown */, &setlist
);
484 add_prefix_cmd ("tcp", class_maintenance
, show_tcp_cmd
, _("\
485 TCP protocol specific variables\n\
486 Configure variables specific to remote TCP connections"),
487 &tcp_show_cmdlist
, "show tcp ",
488 0 /* allow-unknown */, &showlist
);
490 add_setshow_boolean_cmd ("auto-retry", class_obscure
,
491 &tcp_auto_retry
, _("\
492 Set auto-retry on socket connect"), _("\
493 Show auto-retry on socket connect"),
495 &tcp_set_cmdlist
, &tcp_show_cmdlist
);
497 add_setshow_uinteger_cmd ("connect-timeout", class_obscure
,
498 &tcp_retry_limit
, _("\
499 Set timeout limit in seconds for socket connection"), _("\
500 Show timeout limit in seconds for socket connection"), _("\
501 If set to \"unlimited\", GDB will keep attempting to establish a\n\
502 connection forever, unless interrupted with Ctrl-c.\n\
503 The default is 15 seconds."),
505 &tcp_set_cmdlist
, &tcp_show_cmdlist
);