aboutsummaryrefslogtreecommitdiff
path: root/gdb/ser-pipe.c
blob: b4ab672664e5b8fd3afd7ab325732069565fecf4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
/* Serial interface for a pipe to a separate program
   Copyright (C) 1999-2013 Free Software Foundation, Inc.

   Contributed by Cygnus Solutions.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "serial.h"
#include "ser-base.h"
#include "ser-unix.h"

#include "gdb_vfork.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <fcntl.h>
#include <string.h>
#include "filestuff.h"

#include <signal.h>

static int pipe_open (struct serial *scb, const char *name);
static void pipe_close (struct serial *scb);

extern void _initialize_ser_pipe (void);

struct pipe_state
  {
    int pid;
  };

/* Open up a raw pipe.  */

static int
pipe_open (struct serial *scb, const char *name)
{
#if !HAVE_SOCKETPAIR
  return -1;
#else
  struct pipe_state *state;
  /* This chunk: */
  /* Copyright (c) 1988, 1993
   *      The Regents of the University of California.  All rights reserved.
   *
   * This code is derived from software written by Ken Arnold and
   * published in UNIX Review, Vol. 6, No. 8.
   */
  int pdes[2];
  int err_pdes[2];
  int pid;

  if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
    return -1;
  if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, err_pdes) < 0)
    {
      close (pdes[0]);
      close (pdes[1]);
      return -1;
    }

  /* Create the child process to run the command in.  Note that the
     apparent call to vfork() below *might* actually be a call to
     fork() due to the fact that autoconf will ``#define vfork fork''
     on certain platforms.  */
  pid = vfork ();
  
  /* Error.  */
  if (pid == -1)
    {
      close (pdes[0]);
      close (pdes[1]);
      close (err_pdes[0]);
      close (err_pdes[1]);
      return -1;
    }

  if (fcntl (err_pdes[0], F_SETFL, O_NONBLOCK) == -1)
    {
      close (err_pdes[0]);
      close (err_pdes[1]);
      err_pdes[0] = err_pdes[1] = -1;
    }

  /* Child.  */
  if (pid == 0)
    {
      /* We don't want ^c to kill the connection.  */
#ifdef HAVE_SETSID
      pid_t sid = setsid ();
      if (sid == -1)
	signal (SIGINT, SIG_IGN);
#else
      signal (SIGINT, SIG_IGN);
#endif

      /* Re-wire pdes[1] to stdin/stdout.  */
      close (pdes[0]);
      if (pdes[1] != STDOUT_FILENO)
	{
	  dup2 (pdes[1], STDOUT_FILENO);
	  close (pdes[1]);
	}
      dup2 (STDOUT_FILENO, STDIN_FILENO);

      if (err_pdes[0] != -1)
	{
	  close (err_pdes[0]);
	  dup2 (err_pdes[1], STDERR_FILENO);
	  close (err_pdes[1]);
	}

      close_most_fds ();
      execl ("/bin/sh", "sh", "-c", name, (char *) 0);
      _exit (127);
    }

  /* Parent.  */
  close (pdes[1]);
  if (err_pdes[1] != -1)
    close (err_pdes[1]);
  /* :end chunk */
  state = XMALLOC (struct pipe_state);
  state->pid = pid;
  scb->fd = pdes[0];
  scb->error_fd = err_pdes[0];
  scb->state = state;

  /* If we don't do this, GDB simply exits when the remote side dies.  */
  signal (SIGPIPE, SIG_IGN);
  return 0;
#endif
}

static void
pipe_close (struct serial *scb)
{
  struct pipe_state *state = scb->state;

  close (scb->fd);
  scb->fd = -1;

  if (state != NULL)
    {
      int wait_result, status;

      /* Don't kill the task right away, give it a chance to shut down cleanly.
	 But don't wait forever though.  */
#define PIPE_CLOSE_TIMEOUT 5

      /* Assume the program will exit after SIGTERM.  Might be
	 useful to print any remaining stderr output from
	 scb->error_fd while waiting.  */
#define SIGTERM_TIMEOUT INT_MAX

      wait_result = -1;
#ifdef HAVE_WAITPID
      wait_result = wait_to_die_with_timeout (state->pid, &status,
					      PIPE_CLOSE_TIMEOUT);
#endif
      if (wait_result == -1)
	{
	  kill (state->pid, SIGTERM);
#ifdef HAVE_WAITPID
	  wait_to_die_with_timeout (state->pid, &status, SIGTERM_TIMEOUT);
#endif
	}

      if (scb->error_fd != -1)
	close (scb->error_fd);
      scb->error_fd = -1;
      xfree (state);
      scb->state = NULL;
    }
}

int
gdb_pipe (int pdes[2])
{
#if !HAVE_SOCKETPAIR
  errno = ENOSYS;
  return -1;
#else

  if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
    return -1;

  /* If we don't do this, GDB simply exits when the remote side
     dies.  */
  signal (SIGPIPE, SIG_IGN);
  return 0;
#endif
}

void
_initialize_ser_pipe (void)
{
  struct serial_ops *ops = XMALLOC (struct serial_ops);

  memset (ops, 0, sizeof (struct serial_ops));
  ops->name = "pipe";
  ops->next = 0;
  ops->open = pipe_open;
  ops->close = pipe_close;
  ops->readchar = ser_base_readchar;
  ops->write = ser_base_write;
  ops->flush_output = ser_base_flush_output;
  ops->flush_input = ser_base_flush_input;
  ops->send_break = ser_base_send_break;
  ops->go_raw = ser_base_raw;
  ops->get_tty_state = ser_base_get_tty_state;
  ops->copy_tty_state = ser_base_copy_tty_state;
  ops->set_tty_state = ser_base_set_tty_state;
  ops->print_tty_state = ser_base_print_tty_state;
  ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
  ops->setbaudrate = ser_base_setbaudrate;
  ops->setstopbits = ser_base_setstopbits;
  ops->drain_output = ser_base_drain_output;
  ops->async = ser_base_async;
  ops->read_prim = ser_unix_read_prim;
  ops->write_prim = ser_unix_write_prim;
  serial_add_interface (ops);
}