summaryrefslogtreecommitdiff
path: root/gdb/ser-pipe.c
blob: bca0e54e4bab95eb834e2229f6dc1d1ac228ccd2 (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
/* Serial interface for a pipe to a separate program
   Copyright 1999, 2000, 2001 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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "serial.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 "gdb_string.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 pid;
  if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
    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]);
      return -1;
    }

  /* Child. */
  if (pid == 0)
    {
      /* 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 0
      /* close any stray FD's - FIXME - how? */
      /* POSIX.2 B.3.2.2 "popen() shall ensure that any streams
         from previous popen() calls that remain open in the 
         parent process are closed in the new child process. */
      for (old = pidlist; old; old = old->next)
	close (fileno (old->fp));	/* don't allow a flush */
#endif
      execl ("/bin/sh", "sh", "-c", name, NULL);
      _exit (127);
    }

  /* Parent. */
  close (pdes[1]);
  /* :end chunk */
  state = XMALLOC (struct pipe_state);
  state->pid = pid;
  scb->fd = 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;
  if (state != NULL)
    {
      int pid = state->pid;
      close (scb->fd);
      scb->fd = -1;
      xfree (state);
      scb->state = NULL;
      kill (pid, SIGTERM);
      /* Might be useful to check that the child does die. */
    }
}

static struct serial_ops pipe_ops;

void
_initialize_ser_pipe (void)
{
  struct serial_ops *ops = XMALLOC (struct serial_ops);
  memset (ops, sizeof (struct serial_ops), 0);
  ops->name = "pipe";
  ops->next = 0;
  ops->open = pipe_open;
  ops->close = pipe_close;
  ops->readchar = ser_unix_readchar;
  ops->write = ser_unix_write;
  ops->flush_output = ser_unix_nop_flush_output;
  ops->flush_input = ser_unix_flush_input;
  ops->send_break = ser_unix_nop_send_break;
  ops->go_raw = ser_unix_nop_raw;
  ops->get_tty_state = ser_unix_nop_get_tty_state;
  ops->set_tty_state = ser_unix_nop_set_tty_state;
  ops->print_tty_state = ser_unix_nop_print_tty_state;
  ops->noflush_set_tty_state = ser_unix_nop_noflush_set_tty_state;
  ops->setbaudrate = ser_unix_nop_setbaudrate;
  ops->setstopbits = ser_unix_nop_setstopbits;
  ops->drain_output = ser_unix_nop_drain_output;
  ops->async = ser_unix_async;
  serial_add_interface (ops);
}