remote-utils.c

这个是LINUX下的GDB调度工具的源码

/* Remote utility routines for the remote server for GDB.
   Copyright 1986, 1989, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
   2002, 2003, 2004
   Free Software Foundation, Inc.

   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 "server.h"
#include "terminal.h"
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/tcp.h>
#include <sys/ioctl.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/time.h>
#include <unistd.h>
#include <arpa/inet.h>

/* A cache entry for a successfully looked-up symbol.  */
struct sym_cache
{
  const char *name;
  CORE_ADDR addr;
  struct sym_cache *next;
};

/* The symbol cache.  */
static struct sym_cache *symbol_cache;

int remote_debug = 0;
struct ui_file *gdb_stdlog;

static int remote_desc;

/* FIXME headerize? */
extern int using_threads;
extern int debug_threads;

/* Open a connection to a remote debugger.
   NAME is the filename used for communication.  */

void
remote_open (char *name)
{
  int save_fcntl_flags;
  
  if (!strchr (name, ':'))
    {
      remote_desc = open (name, O_RDWR);
      if (remote_desc < 0)
	perror_with_name ("Could not open remote device");

#ifdef HAVE_TERMIOS
      {
	struct termios termios;
	tcgetattr (remote_desc, &termios);

	termios.c_iflag = 0;
	termios.c_oflag = 0;
	termios.c_lflag = 0;
	termios.c_cflag &= ~(CSIZE | PARENB);
	termios.c_cflag |= CLOCAL | CS8;
	termios.c_cc[VMIN] = 1;
	termios.c_cc[VTIME] = 0;

	tcsetattr (remote_desc, TCSANOW, &termios);
      }
#endif

#ifdef HAVE_TERMIO
      {
	struct termio termio;
	ioctl (remote_desc, TCGETA, &termio);

	termio.c_iflag = 0;
	termio.c_oflag = 0;
	termio.c_lflag = 0;
	termio.c_cflag &= ~(CSIZE | PARENB);
	termio.c_cflag |= CLOCAL | CS8;
	termio.c_cc[VMIN] = 1;
	termio.c_cc[VTIME] = 0;

	ioctl (remote_desc, TCSETA, &termio);
      }
#endif

#ifdef HAVE_SGTTY
      {
	struct sgttyb sg;

	ioctl (remote_desc, TIOCGETP, &sg);
	sg.sg_flags = RAW;
	ioctl (remote_desc, TIOCSETP, &sg);
      }
#endif

      fprintf (stderr, "Remote debugging using %s\n", name);
    }
  else
    {
      char *port_str;
      int port;
      struct sockaddr_in sockaddr;
      int tmp;
      int tmp_desc;

      port_str = strchr (name, ':');

      port = atoi (port_str + 1);

      tmp_desc = socket (PF_INET, SOCK_STREAM, 0);
      if (tmp_desc < 0)
	perror_with_name ("Can't open socket");

      /* Allow rapid reuse of this port. */
      tmp = 1;
      setsockopt (tmp_desc, SOL_SOCKET, SO_REUSEADDR, (char *) &tmp,
		  sizeof (tmp));

      sockaddr.sin_family = PF_INET;
      sockaddr.sin_port = htons (port);
      sockaddr.sin_addr.s_addr = INADDR_ANY;

      if (bind (tmp_desc, (struct sockaddr *) &sockaddr, sizeof (sockaddr))
	  || listen (tmp_desc, 1))
	perror_with_name ("Can't bind address");

      fprintf (stderr, "Listening on port %d\n", port);

      tmp = sizeof (sockaddr);
      remote_desc = accept (tmp_desc, (struct sockaddr *) &sockaddr, &tmp);
      if (remote_desc == -1)
	perror_with_name ("Accept failed");

      /* Enable TCP keep alive process. */
      tmp = 1;
      setsockopt (tmp_desc, SOL_SOCKET, SO_KEEPALIVE, (char *) &tmp, sizeof (tmp));

      /* Tell TCP not to delay small packets.  This greatly speeds up
         interactive response. */
      tmp = 1;
      setsockopt (remote_desc, IPPROTO_TCP, TCP_NODELAY,
		  (char *) &tmp, sizeof (tmp));

      close (tmp_desc);		/* No longer need this */

      signal (SIGPIPE, SIG_IGN);	/* If we don't do this, then gdbserver simply
					   exits when the remote side dies.  */

      /* Convert IP address to string.  */
      fprintf (stderr, "Remote debugging from host %s\n", 
         inet_ntoa (sockaddr.sin_addr));
    }

#if defined(F_SETFL) && defined (FASYNC)
  save_fcntl_flags = fcntl (remote_desc, F_GETFL, 0);
  fcntl (remote_desc, F_SETFL, save_fcntl_flags | FASYNC);
#if defined (F_SETOWN)
  fcntl (remote_desc, F_SETOWN, getpid ());
#endif
#endif
  disable_async_io ();
}

void
remote_close (void)
{
  close (remote_desc);
}

/* Convert hex digit A to a number.  */

static int
fromhex (int a)
{
  if (a >= '0' && a <= '9')
    return a - '0';
  else if (a >= 'a' && a <= 'f')
    return a - 'a' + 10;
  else
    error ("Reply contains invalid hex digit");
  return 0;
}

int
unhexify (char *bin, const char *hex, int count)
{
  int i;

  for (i = 0; i < count; i++)
    {
      if (hex[0] == 0 || hex[1] == 0)
        {
          /* Hex string is short, or of uneven length.
             Return the count that has been converted so far. */
          return i;
        }
      *bin++ = fromhex (hex[0]) * 16 + fromhex (hex[1]);
      hex += 2;
    }
  return i;
}

static void
decode_address (CORE_ADDR *addrp, const char *start, int len)
{
  CORE_ADDR addr;
  char ch;
  int i;

  addr = 0;
  for (i = 0; i < len; i++)
    {
      ch = start[i];
      addr = addr << 4;
      addr = addr | (fromhex (ch) & 0x0f);
    }
  *addrp = addr;
}

/* Convert number NIB to a hex digit.  */

static int
tohex (int nib)
{
  if (nib < 10)
    return '0' + nib;
  else
    return 'a' + nib - 10;
}

int
hexify (char *hex, const char *bin, int count)
{
  int i;

  /* May use a length, or a nul-terminated string as input. */
  if (count == 0)
    count = strlen (bin);

  for (i = 0; i < count; i++)
    {
      *hex++ = tohex ((*bin >> 4) & 0xf);
      *hex++ = tohex (*bin++ & 0xf);
    }
  *hex = 0;
  return i;
}

/* Send a packet to the remote machine, with error checking.
   The data of the packet is in BUF.  Returns >= 0 on success, -1 otherwise. */

int
putpkt (char *buf)
{
  int i;
  unsigned char csum = 0;
  char *buf2;
  char buf3[1];
  int cnt = strlen (buf);
  char *p;

  buf2 = malloc (PBUFSIZ);

  /* Copy the packet into buffer BUF2, encapsulating it
     and giving it a checksum.  */

  p = buf2;
  *p++ = '$';

  for (i = 0; i < cnt; i++)
    {
      csum += buf[i];
      *p++ = buf[i];
    }
  *p++ = '#';
  *p++ = tohex ((csum >> 4) & 0xf);
  *p++ = tohex (csum & 0xf);

  *p = '\0';

  /* Send it over and over until we get a positive ack.  */

  do
    {
      int cc;

      if (write (remote_desc, buf2, p - buf2) != p - buf2)
	{
	  perror ("putpkt(write)");
	  return -1;
	}

      if (remote_debug)
	{
	  fprintf (stderr, "putpkt (\"%s\"); [looking for ack]\n", buf2);
	  fflush (stderr);
	}
      cc = read (remote_desc, buf3, 1);
      if (remote_debug)
	{
	  fprintf (stderr, "[received '%c' (0x%x)]\n", buf3[0], buf3[0]);
	  fflush (stderr);
	}

      if (cc <= 0)
	{
	  if (cc == 0)
	    fprintf (stderr, "putpkt(read): Got EOF\n");
	  else
	    perror ("putpkt(read)");

	  free (buf2);
	  return -1;
	}

      /* Check for an input interrupt while we're here.  */
      if (buf3[0] == '\003')
	(*the_target->send_signal) (SIGINT);
    }
  while (buf3[0] != '+');

  free (buf2);
  return 1;			/* Success! */
}

/* Come here when we get an input interrupt from the remote side.  This
   interrupt should only be active while we are waiting for the child to do
   something.  About the only thing that should come through is a ^C, which
   will cause us to send a SIGINT to the child.  */

static void
input_interrupt (int unused)
{
  fd_set readset;
  struct timeval immediate = { 0, 0 };

  /* Protect against spurious interrupts.  This has been observed to
     be a problem under NetBSD 1.4 and 1.5.  */

  FD_ZERO (&readset);
  FD_SET (remote_desc, &readset);
  if (select (remote_desc + 1, &readset, 0, 0, &immediate) > 0)
    {
      int cc;
      char c = 0;
      
      cc = read (remote_desc, &c, 1);

      if (cc != 1 || c != '\003')
	{
	  fprintf (stderr, "input_interrupt, count = %d c = %d ('%c')\n",
		   cc, c, c);
	  return;
	}
      
      (*the_target->send_signal) (SIGINT);
    }
}

void
block_async_io (void)
{
  sigset_t sigio_set;
  sigemptyset (&sigio_set);
  sigaddset (&sigio_set, SIGIO);
  sigprocmask (SIG_BLOCK, &sigio_set, NULL);
}

void
unblock_async_io (void)
{