gdb/ser-pipe.c - binutils-gdb - Git at Google

 /* Serial interface for a pipe to a separate program
    Copyright 1999 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 <sys/types.h>
 #include <sys/wait.h>
 #include <sys/socket.h>
 #include <sys/time.h>
 #include <fcntl.h>
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif

 #include "signals.h"
 #include "gdb_string.h"

 extern int (*ui_loop_hook) PARAMS ((int));

 static int pipe_open PARAMS ((serial_t scb, const char *name));
 static void pipe_raw PARAMS ((serial_t scb));
 static int wait_for PARAMS ((serial_t scb, int timeout));
 static int pipe_readchar PARAMS ((serial_t scb, int timeout));
 static int pipe_setbaudrate PARAMS ((serial_t scb, int rate));
 static int pipe_setstopbits PARAMS ((serial_t scb, int num));
 static int pipe_write PARAMS ((serial_t scb, const char *str, int len));
 /* FIXME: static void pipe_restore PARAMS ((serial_t scb)); */
 static void pipe_close PARAMS ((serial_t scb));
 static serial_ttystate pipe_get_tty_state PARAMS ((serial_t scb));
 static int pipe_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
 static int pipe_return_0 PARAMS ((serial_t));
 static int pipe_noflush_set_tty_state PARAMS ((serial_t, serial_ttystate,
 					       serial_ttystate));
 static void pipe_print_tty_state PARAMS ((serial_t, serial_ttystate));

 extern void _initialize_ser_pipe PARAMS ((void));

 #undef XMALLOC
 #define XMALLOC(T) ((T*) xmalloc (sizeof (T)))


 struct pipe_state
   {
     int pid;
   };

 /* Open up a raw pipe */

 static int
 pipe_open (scb, name)
      serial_t scb;
      const char *name;
 {
 #if !defined(O_NONBLOCK) || !defined(F_GETFL) || !defined(F_SETFL)
   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;

   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 + 1, NULL);
       _exit (127);
     }

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

   /* Make it non-blocking */
   {
     int flags = fcntl (scb->fd, F_GETFL, 0);
     if (fcntl (scb->fd, F_SETFL, flags | O_NONBLOCK) < 0)
       {
 	perror ("ser-pipe");
 	pipe_close (scb);
 	return -1;
       }
   }

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

 static serial_ttystate
 pipe_get_tty_state (scb)
      serial_t scb;
 {
   /* return garbage */
   return xmalloc (sizeof (int));
 }

 static int
 pipe_set_tty_state (scb, ttystate)
      serial_t scb;
      serial_ttystate ttystate;
 {
   return 0;
 }

 static int
 pipe_return_0 (scb)
      serial_t scb;
 {
   return 0;
 }

 static void
 pipe_raw (scb)
      serial_t scb;
 {
   return;			/* Always in raw mode */
 }

 /* Wait for input on scb, with timeout seconds.  Returns 0 on success,
    otherwise SERIAL_TIMEOUT or SERIAL_ERROR.

    For termio{s}, we actually just setup VTIME if necessary, and let the
    timeout occur in the read() in pipe_read().
  */

 static int
 wait_for (scb, timeout)
      serial_t scb;
      int timeout;
 {
   int numfds;
   struct timeval tv;
   fd_set readfds, exceptfds;

   FD_ZERO (&readfds);
   FD_ZERO (&exceptfds);

   tv.tv_sec = timeout;
   tv.tv_usec = 0;

   FD_SET (scb->fd, &readfds);
   FD_SET (scb->fd, &exceptfds);

   while (1)
     {
       if (timeout >= 0)
 	numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, &tv);
       else
 	numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, 0);

       if (numfds <= 0)
 	{
 	  if (numfds == 0)
 	    return SERIAL_TIMEOUT;
 	  else if (errno == EINTR)
 	    continue;
 	  else
 	    return SERIAL_ERROR;	/* Got an error from select or poll */
 	}

       return 0;
     }
 }

 /* Read a character with user-specified timeout.  TIMEOUT is number of seconds
    to wait, or -1 to wait forever.  Use timeout of 0 to effect a poll.  Returns
    char if successful.  Returns -2 if timeout expired, EOF if line dropped
    dead, or -3 for any other error (see errno in that case). */

 static int
 pipe_readchar (scb, timeout)
      serial_t scb;
      int timeout;
 {
   int status;
   int delta;

   if (scb->bufcnt-- > 0)
     return *scb->bufp++;

   /* We have to be able to keep the GUI alive here, so we break the original
      timeout into steps of 1 second, running the "keep the GUI alive" hook
      each time through the loop.

      Also, timeout = 0 means to poll, so we just set the delta to 0, so we
      will only go through the loop once. */

   delta = (timeout == 0 ? 0 : 1);
   while (1)
     {

       /* N.B. The UI may destroy our world (for instance by calling
          remote_stop,) in which case we want to get out of here as
          quickly as possible.  It is not safe to touch scb, since
          someone else might have freed it.  The ui_loop_hook signals that
          we should exit by returning 1. */

       if (ui_loop_hook)
 	{
 	  if (ui_loop_hook (0))
 	    return SERIAL_TIMEOUT;
 	}

       status = wait_for (scb, delta);
       timeout -= delta;

       /* If we got a character or an error back from wait_for, then we can
          break from the loop before the timeout is completed. */

       if (status != SERIAL_TIMEOUT)
 	{
 	  break;
 	}

       /* If we have exhausted the original timeout, then generate
          a SERIAL_TIMEOUT, and pass it out of the loop. */

       else if (timeout == 0)
 	{
 	  status == SERIAL_TIMEOUT;
 	  break;
 	}
     }

   if (status < 0)
     return status;

   while (1)
     {
       scb->bufcnt = read (scb->fd, scb->buf, BUFSIZ);
       if (scb->bufcnt != -1 || errno != EINTR)
 	break;
     }

   if (scb->bufcnt <= 0)
     {
       if (scb->bufcnt == 0)
 	return SERIAL_TIMEOUT;	/* 0 chars means timeout [may need to
 				   distinguish between EOF & timeouts
 				   someday] */
       else
 	return SERIAL_ERROR;	/* Got an error from read */
     }

   scb->bufcnt--;
   scb->bufp = scb->buf;
   return *scb->bufp++;
 }

 static int
 pipe_noflush_set_tty_state (scb, new_ttystate, old_ttystate)
      serial_t scb;
      serial_ttystate new_ttystate;
      serial_ttystate old_ttystate;
 {
   return 0;
 }

 static void
 pipe_print_tty_state (scb, ttystate)
      serial_t scb;
      serial_ttystate ttystate;
 {
   /* Nothing to print.  */
   return;
 }

 static int
 pipe_setbaudrate (scb, rate)
      serial_t scb;
      int rate;
 {
   return 0;			/* Never fails! */
 }

 static int
 pipe_setstopbits (scb, num)
      serial_t scb;
      int num;
 {
   return 0;			/* Never fails! */
 }

 static int
 pipe_write (scb, str, len)
      serial_t scb;
      const char *str;
      int len;
 {
   int cc;

   while (len > 0)
     {
       cc = write (scb->fd, str, len);

       if (cc < 0)
 	return 1;
       len -= cc;
       str += cc;
     }
   return 0;
 }

 static void
 pipe_close (scb)
      serial_t scb;
 {
   struct pipe_state *state = scb->state;
   if (state != NULL)
     {
       int pid = state->pid;
       close (scb->fd);
       scb->fd = -1;
       free (state);
       scb->state = NULL;
       kill (pid, SIGTERM);
       /* Might be useful to check that the child does die. */
     }
 }

 static struct serial_ops pipe_ops =
 {
   "pipe",
   0,
   pipe_open,
   pipe_close,
   pipe_readchar,
   pipe_write,
   pipe_return_0,		/* flush output */
   pipe_return_0,		/* flush input */
   pipe_return_0,		/* send break */
   pipe_raw,
   pipe_get_tty_state,
   pipe_set_tty_state,
   pipe_print_tty_state,
   pipe_noflush_set_tty_state,
   pipe_setbaudrate,
   pipe_setstopbits,
   pipe_return_0,		/* wait for output to drain */
 };

 void
 _initialize_ser_pipe ()
 {
   serial_add_interface (&pipe_ops);
 }
	/* Serial interface for a pipe to a separate program
	Copyright 1999 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 <sys/types.h>
	#include <sys/wait.h>
	#include <sys/socket.h>
	#include <sys/time.h>
	#include <fcntl.h>
	#ifdef HAVE_UNISTD_H
	#include <unistd.h>
	#endif

	#include "signals.h"
	#include "gdb_string.h"

	extern int (*ui_loop_hook) PARAMS ((int));

	static int pipe_open PARAMS ((serial_t scb, const char *name));
	static void pipe_raw PARAMS ((serial_t scb));
	static int wait_for PARAMS ((serial_t scb, int timeout));
	static int pipe_readchar PARAMS ((serial_t scb, int timeout));
	static int pipe_setbaudrate PARAMS ((serial_t scb, int rate));
	static int pipe_setstopbits PARAMS ((serial_t scb, int num));
	static int pipe_write PARAMS ((serial_t scb, const char *str, int len));
	/* FIXME: static void pipe_restore PARAMS ((serial_t scb)); */
	static void pipe_close PARAMS ((serial_t scb));
	static serial_ttystate pipe_get_tty_state PARAMS ((serial_t scb));
	static int pipe_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
	static int pipe_return_0 PARAMS ((serial_t));
	static int pipe_noflush_set_tty_state PARAMS ((serial_t, serial_ttystate,
	serial_ttystate));
	static void pipe_print_tty_state PARAMS ((serial_t, serial_ttystate));

	extern void _initialize_ser_pipe PARAMS ((void));

	#undef XMALLOC
	#define XMALLOC(T) ((T*) xmalloc (sizeof (T)))


	struct pipe_state
	{
	int pid;
	};

	/* Open up a raw pipe */

	static int
	pipe_open (scb, name)
	serial_t scb;
	const char *name;
	{
	#if !defined(O_NONBLOCK) \|\| !defined(F_GETFL) \|\| !defined(F_SETFL)
	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;

	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 + 1, NULL);
	_exit (127);
	}

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

	/* Make it non-blocking */
	{
	int flags = fcntl (scb->fd, F_GETFL, 0);
	if (fcntl (scb->fd, F_SETFL, flags \| O_NONBLOCK) < 0)
	{
	perror ("ser-pipe");
	pipe_close (scb);
	return -1;
	}
	}

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

	static serial_ttystate
	pipe_get_tty_state (scb)
	serial_t scb;
	{
	/* return garbage */
	return xmalloc (sizeof (int));
	}

	static int
	pipe_set_tty_state (scb, ttystate)
	serial_t scb;
	serial_ttystate ttystate;
	{
	return 0;
	}

	static int
	pipe_return_0 (scb)
	serial_t scb;
	{
	return 0;
	}

	static void
	pipe_raw (scb)
	serial_t scb;
	{
	return; /* Always in raw mode */
	}

	/* Wait for input on scb, with timeout seconds. Returns 0 on success,
	otherwise SERIAL_TIMEOUT or SERIAL_ERROR.

	For termio{s}, we actually just setup VTIME if necessary, and let the
	timeout occur in the read() in pipe_read().
	*/

	static int
	wait_for (scb, timeout)
	serial_t scb;
	int timeout;
	{
	int numfds;
	struct timeval tv;
	fd_set readfds, exceptfds;

	FD_ZERO (&readfds);
	FD_ZERO (&exceptfds);

	tv.tv_sec = timeout;
	tv.tv_usec = 0;

	FD_SET (scb->fd, &readfds);
	FD_SET (scb->fd, &exceptfds);

	while (1)
	{
	if (timeout >= 0)
	numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, &tv);
	else
	numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, 0);

	if (numfds <= 0)
	{
	if (numfds == 0)
	return SERIAL_TIMEOUT;
	else if (errno == EINTR)
	continue;
	else
	return SERIAL_ERROR; /* Got an error from select or poll */
	}

	return 0;
	}
	}

	/* Read a character with user-specified timeout. TIMEOUT is number of seconds
	to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns
	char if successful. Returns -2 if timeout expired, EOF if line dropped
	dead, or -3 for any other error (see errno in that case). */

	static int
	pipe_readchar (scb, timeout)
	serial_t scb;
	int timeout;
	{
	int status;
	int delta;

	if (scb->bufcnt-- > 0)
	return *scb->bufp++;

	/* We have to be able to keep the GUI alive here, so we break the original
	timeout into steps of 1 second, running the "keep the GUI alive" hook
	each time through the loop.

	Also, timeout = 0 means to poll, so we just set the delta to 0, so we
	will only go through the loop once. */

	delta = (timeout == 0 ? 0 : 1);
	while (1)
	{

	/* N.B. The UI may destroy our world (for instance by calling
	remote_stop,) in which case we want to get out of here as
	quickly as possible. It is not safe to touch scb, since
	someone else might have freed it. The ui_loop_hook signals that
	we should exit by returning 1. */

	if (ui_loop_hook)
	{
	if (ui_loop_hook (0))
	return SERIAL_TIMEOUT;
	}

	status = wait_for (scb, delta);
	timeout -= delta;

	/* If we got a character or an error back from wait_for, then we can
	break from the loop before the timeout is completed. */

	if (status != SERIAL_TIMEOUT)
	{
	break;
	}

	/* If we have exhausted the original timeout, then generate
	a SERIAL_TIMEOUT, and pass it out of the loop. */

	else if (timeout == 0)
	{
	status == SERIAL_TIMEOUT;
	break;
	}
	}

	if (status < 0)
	return status;

	while (1)
	{
	scb->bufcnt = read (scb->fd, scb->buf, BUFSIZ);
	if (scb->bufcnt != -1 \|\| errno != EINTR)
	break;
	}

	if (scb->bufcnt <= 0)
	{
	if (scb->bufcnt == 0)
	return SERIAL_TIMEOUT; /* 0 chars means timeout [may need to
	distinguish between EOF & timeouts
	someday] */
	else
	return SERIAL_ERROR; /* Got an error from read */
	}

	scb->bufcnt--;
	scb->bufp = scb->buf;
	return *scb->bufp++;
	}

	static int
	pipe_noflush_set_tty_state (scb, new_ttystate, old_ttystate)
	serial_t scb;
	serial_ttystate new_ttystate;
	serial_ttystate old_ttystate;
	{
	return 0;
	}

	static void
	pipe_print_tty_state (scb, ttystate)
	serial_t scb;
	serial_ttystate ttystate;
	{
	/* Nothing to print. */
	return;
	}

	static int
	pipe_setbaudrate (scb, rate)
	serial_t scb;
	int rate;
	{
	return 0; /* Never fails! */
	}

	static int
	pipe_setstopbits (scb, num)
	serial_t scb;
	int num;
	{
	return 0; /* Never fails! */
	}

	static int
	pipe_write (scb, str, len)
	serial_t scb;
	const char *str;
	int len;
	{
	int cc;

	while (len > 0)
	{
	cc = write (scb->fd, str, len);

	if (cc < 0)
	return 1;
	len -= cc;
	str += cc;
	}
	return 0;
	}

	static void
	pipe_close (scb)
	serial_t scb;
	{
	struct pipe_state *state = scb->state;
	if (state != NULL)
	{
	int pid = state->pid;
	close (scb->fd);
	scb->fd = -1;
	free (state);
	scb->state = NULL;
	kill (pid, SIGTERM);
	/* Might be useful to check that the child does die. */
	}
	}

	static struct serial_ops pipe_ops =
	{
	"pipe",
	0,
	pipe_open,
	pipe_close,
	pipe_readchar,
	pipe_write,
	pipe_return_0, /* flush output */
	pipe_return_0, /* flush input */
	pipe_return_0, /* send break */
	pipe_raw,
	pipe_get_tty_state,
	pipe_set_tty_state,
	pipe_print_tty_state,
	pipe_noflush_set_tty_state,
	pipe_setbaudrate,
	pipe_setstopbits,
	pipe_return_0, /* wait for output to drain */
	};

	void
	_initialize_ser_pipe ()
	{
	serial_add_interface (&pipe_ops);
	}