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/* Remote utility routines for the remote server for GDB.

   Copyright (C) 1986, 1989, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,

   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008

   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 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 "server.h"

#include "terminal.h"

#include <stdio.h>

#include <string.h>

#if HAVE_SYS_IOCTL_H

#include <sys/ioctl.h>

#endif

#if HAVE_SYS_FILE_H

#include <sys/file.h>

#endif

#if HAVE_NETINET_IN_H

#include <netinet/in.h>

#endif

#if HAVE_SYS_SOCKET_H

#include <sys/socket.h>

#endif

#if HAVE_NETDB_H

#include <netdb.h>

#endif

#if HAVE_NETINET_TCP_H

#include <netinet/tcp.h>

#endif

#if HAVE_SYS_IOCTL_H

#include <sys/ioctl.h>

#endif

#if HAVE_SIGNAL_H

#include <signal.h>

#endif

#if HAVE_FCNTL_H

#include <fcntl.h>

#endif

#include <sys/time.h>

#if HAVE_UNISTD_H

#include <unistd.h>

#endif

#if HAVE_ARPA_INET_H

#include <arpa/inet.h>

#endif

#include <sys/stat.h>

#if HAVE_ERRNO_H

#include <errno.h>

#endif

#if USE_WIN32API

#include <winsock.h>

#endif

#ifndef HAVE_SOCKLEN_T

typedef int socklen_t;

#endif

#if USE_WIN32API

# define INVALID_DESCRIPTOR INVALID_SOCKET

#else

# define INVALID_DESCRIPTOR -1

#endif

/* 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;

/* If this flag has been set, assume cache misses are

   failures.  */

int all_symbols_looked_up;

int remote_debug = 0;

struct ui_file *gdb_stdlog;

static int remote_desc = INVALID_DESCRIPTOR;

/* FIXME headerize? */

extern int using_threads;

extern int debug_threads;

#ifdef USE_WIN32API

# define read(fd, buf, len) recv (fd, (char *) buf, len, 0)

# define write(fd, buf, len) send (fd, (char *) buf, len, 0)

#endif

/* Open a connection to a remote debugger.

   NAME is the filename used for communication.  */

void

remote_open (char *name)

{

#if defined(F_SETFL) && defined (FASYNC)

  int save_fcntl_flags;

#endif

  char *port_str;

  port_str = strchr (name, ':');

  if (port_str == NULL)

    {

#ifdef USE_WIN32API

      error ("Only <host>:<port> is supported on this platform.");

#else

      struct stat statbuf;

      if (stat (name, &statbuf) == 0

          && (S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)))

        remote_desc = open (name, O_RDWR);

      else

        {

          errno = EINVAL;

          remote_desc = -1;

        }

      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);

#endif /* USE_WIN32API */

    }

  else

    {

#ifdef USE_WIN32API

      static int winsock_initialized;

#endif

      int port;

      struct sockaddr_in sockaddr;

      socklen_t tmp;

      int tmp_desc;

      char *port_end;

      port = strtoul (port_str + 1, &port_end, 10);

      if (port_str[1] == '\0' || *port_end != '\0')

        fatal ("Bad port argument: %s", name);

#ifdef USE_WIN32API

      if (!winsock_initialized)

        {

          WSADATA wsad;

          WSAStartup (MAKEWORD (1, 0), &wsad);

          winsock_initialized = 1;

        }

#endif

      tmp_desc = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);

      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");

      /* If port is zero, a random port will be selected, and the

         fprintf below needs to know what port was selected.  */

      if (port == 0)

        {

          socklen_t len = sizeof (sockaddr);

          if (getsockname (tmp_desc, (struct sockaddr *) &sockaddr, &len) < 0

              || len < sizeof (sockaddr))

            perror_with_name ("Can't determine port");

          port = ntohs (sockaddr.sin_port);

        }

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

      fflush (stderr);

      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 (remote_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));

#ifndef USE_WIN32API

      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.  */

#else

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

#endif

      /* 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

}

void

remote_close (void)

{

#ifdef USE_WIN32API

  closesocket (remote_desc);

#else

  close (remote_desc);

#endif

}

/* 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;

}

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;

}

const char *

decode_address_to_semicolon (CORE_ADDR *addrp, const char *start)

{

  const char *end;

  end = start;

  while (*end != '\0' && *end != ';')

    end++;

  decode_address (addrp, start, end - start);

  if (*end == ';')

    end++;

  return end;

}

/* 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;

}

/* Convert BUFFER, binary data at least LEN bytes long, into escaped

   binary data in OUT_BUF.  Set *OUT_LEN to the length of the data

   encoded in OUT_BUF, and return the number of bytes in OUT_BUF

   (which may be more than *OUT_LEN due to escape characters).  The

   total number of bytes in the output buffer will be at most

   OUT_MAXLEN.  */

int

remote_escape_output (const gdb_byte *buffer, int len,

                      gdb_byte *out_buf, int *out_len,

                      int out_maxlen)

{

  int input_index, output_index;

  output_index = 0;

  for (input_index = 0; input_index < len; input_index++)

    {

      gdb_byte b = buffer[input_index];

      if (b == '$' || b == '#' || b == '}' || b == '*')

        {

          /* These must be escaped.  */

          if (output_index + 2 > out_maxlen)

            break;

          out_buf[output_index++] = '}';

          out_buf[output_index++] = b ^ 0x20;

        }

      else

        {

          if (output_index + 1 > out_maxlen)

            break;

          out_buf[output_index++] = b;

        }

    }

  *out_len = input_index;

  return output_index;

}

/* Convert BUFFER, escaped data LEN bytes long, into binary data

   in OUT_BUF.  Return the number of bytes written to OUT_BUF.

   Raise an error if the total number of bytes exceeds OUT_MAXLEN.

   This function reverses remote_escape_output.  It allows more

   escaped characters than that function does, in particular because

   '*' must be escaped to avoid the run-length encoding processing

   in reading packets.  */

static int

remote_unescape_input (const gdb_byte *buffer, int len,

                       gdb_byte *out_buf, int out_maxlen)

{

  int input_index, output_index;

  int escaped;

  output_index = 0;

  escaped = 0;

  for (input_index = 0; input_index < len; input_index++)

    {

      gdb_byte b = buffer[input_index];

      if (output_index + 1 > out_maxlen)

        error ("Received too much data from the target.");

      if (escaped)

        {

          out_buf[output_index++] = b ^ 0x20;

          escaped = 0;

        }

      else if (b == '}')

        escaped = 1;

      else

        out_buf[output_index++] = b;

    }

  if (escaped)

    error ("Unmatched escape character in target response.");

  return output_index;

}

/* Look for a sequence of characters which can be run-length encoded.

   If there are any, update *CSUM and *P.  Otherwise, output the

   single character.  Return the number of characters consumed.  */

static int

try_rle (char *buf, int remaining, unsigned char *csum, char **p)

{

  int n;

  /* Always output the character.  */

  *csum += buf[0];

  *(*p)++ = buf[0];

  /* Don't go past '~'.  */

  if (remaining > 97)

    remaining = 97;

  for (n = 1; n < remaining; n++)

    if (buf[n] != buf[0])

      break;

  /* N is the index of the first character not the same as buf[0].

     buf[0] is counted twice, so by decrementing N, we get the number

     of characters the RLE sequence will replace.  */

  n--;

  if (n < 3)

    return 1;

  /* Skip the frame characters.  The manual says to skip '+' and '-'

     also, but there's no reason to.  Unfortunately these two unusable

     characters double the encoded length of a four byte zero

     value.  */

  while (n + 29 == '$' || n + 29 == '#')

    n--;

  *csum += '*';

  *(*p)++ = '*';

  *csum += n + 29;

  *(*p)++ = n + 29;

  return n + 1;

}

/* Send a packet to the remote machine, with error checking.

   The data of the packet is in BUF, and the length of the

   packet is in CNT.  Returns >= 0 on success, -1 otherwise.  */

int

putpkt_binary (char *buf, int cnt)

{

  int i;

  unsigned char csum = 0;

  char *buf2;

  char buf3[1];

  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 += try_rle (buf + i, cnt - i, &csum, &p);

  *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)");

          free (buf2);

          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' && current_inferior != NULL)

        (*the_target->request_interrupt) ();

    }

  while (buf3[0] != '+');

  free (buf2);

  return 1;                     /* Success! */

}

/* Send a packet to the remote machine, with error checking.  The data

   of the packet is in BUF, and the packet should be a NUL-terminated

   string.  Returns >= 0 on success, -1 otherwise.  */

int

putpkt (char *buf)

{

  return putpkt_binary (buf, strlen (buf));

}

/* 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 request child interruption.  */

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' || current_inferior == NULL)

        {

          fprintf (stderr, "input_interrupt, count = %d c = %d ('%c')\n",

                   cc, c, c);

          return;

        }

      (*the_target->request_interrupt) ();

    }

}

/* Check if the remote side sent us an interrupt request (^C).  */

void

check_remote_input_interrupt_request (void)

{

  /* This function may be called before establishing communications,

     therefore we need to validate the remote descriptor.  */

  if (remote_desc == INVALID_DESCRIPTOR)

    return;

  input_interrupt (0);

}

/* Asynchronous I/O support.  SIGIO must be enabled when waiting, in order to

   accept Control-C from the client, and must be disabled when talking to

   the client.  */

static void

unblock_async_io (void)

{

#ifndef USE_WIN32API

  sigset_t sigio_set;

  sigemptyset (&sigio_set);

  sigaddset (&sigio_set, SIGIO);

  sigprocmask (SIG_UNBLOCK, &sigio_set, NULL);

#endif

}

/* Current state of asynchronous I/O.  */

static int async_io_enabled;

/* Enable asynchronous I/O.  */

void

enable_async_io (void)

{

  if (async_io_enabled)

    return;

#ifndef USE_WIN32API

  signal (SIGIO, input_interrupt);

#endif

  async_io_enabled = 1;

}

/* Disable asynchronous I/O.  */

void

disable_async_io (void)

{

  if (!async_io_enabled)

    return;

#ifndef USE_WIN32API

  signal (SIGIO, SIG_IGN);

#endif

  async_io_enabled = 0;

}

void

initialize_async_io (void)

{

  /* Make sure that async I/O starts disabled.  */

  async_io_enabled = 1;

  disable_async_io ();

  /* Make sure the signal is unblocked.  */

  unblock_async_io ();

}

/* Returns next char from remote GDB.  -1 if error.  */