binutils-gdb/gdb/ser-pipe.c

236 lines
5.2 KiB
C

/* Serial interface for a pipe to a separate program
Copyright (C) 1999-2019 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 "gdb_sys_time.h"
#include <fcntl.h>
#include "filestuff.h"
#include <signal.h>
static int pipe_open (struct serial *scb, const char *name);
static void pipe_close (struct serial *scb);
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 = XNEW (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 = (struct pipe_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
}
static const struct serial_ops pipe_ops =
{
"pipe",
pipe_open,
pipe_close,
NULL,
ser_base_readchar,
ser_base_write,
ser_base_flush_output,
ser_base_flush_input,
ser_base_send_break,
ser_base_raw,
ser_base_get_tty_state,
ser_base_copy_tty_state,
ser_base_set_tty_state,
ser_base_print_tty_state,
ser_base_setbaudrate,
ser_base_setstopbits,
ser_base_setparity,
ser_base_drain_output,
ser_base_async,
ser_unix_read_prim,
ser_unix_write_prim
};
void
_initialize_ser_pipe (void)
{
serial_add_interface (&pipe_ops);
}