/* -*- mode: C; c-file-style: "gnu" -*- */
/* dbus-sysdeps.c Wrappers around system/libc features shared between UNIX and Windows (internal to D-Bus implementation)
*
* Copyright (C) 2002, 2003, 2006 Red Hat, Inc.
* Copyright (C) 2003 CodeFactory AB
*
* Licensed under the Academic Free License version 2.1
*
* 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 "dbus-internals.h"
#include "dbus-sysdeps.h"
#include "dbus-threads.h"
#include "dbus-protocol.h"
#include "dbus-string.h"
/* NOTE: If you include any unix/windows-specific headers here, you are probably doing something
* wrong and should be putting some code in dbus-sysdeps-unix.c or dbus-sysdeps-win.c.
*
* These are the standard ANSI C headers...
*/
#include <locale.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
/* This is UNIX-specific (on windows it's just in stdlib.h I believe)
* but OK since the same stuff does exist on Windows in stdlib.h
* and covered by a configure check.
*/
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
_DBUS_DEFINE_GLOBAL_LOCK (win_fds);
_DBUS_DEFINE_GLOBAL_LOCK (sid_atom_cache);
/**
* @defgroup DBusSysdeps Internal system-dependent API
* @ingroup DBusInternals
* @brief Internal system-dependent API available on UNIX and Windows
*
* The system-dependent API has a dual purpose. First, it encapsulates
* all usage of operating system APIs for ease of auditing and to
* avoid cluttering the rest of the code with bizarre OS quirks and
* headers. Second, it abstracts different operating system APIs for
* portability.
*
* @{
*/
/**
* Aborts the program with SIGABRT (dumping core).
*/
void
_dbus_abort (void)
{
const char *s;
_dbus_print_backtrace ();
s = _dbus_getenv ("DBUS_BLOCK_ON_ABORT");
if (s && *s)
{
/* don't use _dbus_warn here since it can _dbus_abort() */
fprintf (stderr, " Process %lu sleeping for gdb attach\n", (unsigned long) _dbus_getpid());
_dbus_sleep_milliseconds (1000 * 180);
}
abort ();
_dbus_exit (1); /* in case someone manages to ignore SIGABRT ? */
}
/**
* Wrapper for setenv(). If the value is #NULL, unsets
* the environment variable.
*
* There is an unfixable memleak in that it is unsafe to
* free memory malloced for use with setenv. This is because
* we can not rely on internal implementation details of
* the underlying libc library.
*
* @param varname name of environment variable
* @param value value of environment variable
* @returns #TRUE on success.
*/
dbus_bool_t
_dbus_setenv (const char *varname,
const char *value)
{
_dbus_assert (varname != NULL);
if (value == NULL)
{
#ifdef HAVE_UNSETENV
unsetenv (varname);
return TRUE;
#else
char *putenv_value;
size_t len;
len = strlen (varname);
/* Use system malloc to avoid memleaks that dbus_malloc
* will get upset about.
*/
putenv_value = malloc (len + 1);
if (putenv_value == NULL)
return FALSE;
strcpy (putenv_value, varname);
return (putenv (putenv_value) == 0);
#endif
}
else
{
#ifdef HAVE_SETENV
return (setenv (varname, value, TRUE) == 0);
#else
char *putenv_value;
size_t len;
size_t varname_len;
size_t value_len;
varname_len = strlen (varname);
value_len = strlen (value);
len = varname_len + value_len + 1 /* '=' */ ;
/* Use system malloc to avoid memleaks that dbus_malloc
* will get upset about.
*/
putenv_value = malloc (len + 1);
if (putenv_value == NULL)
return FALSE;
strcpy (putenv_value, varname);
strcpy (putenv_value + varname_len, "=");
strcpy (putenv_value + varname_len + 1, value);
return (putenv (putenv_value) == 0);
#endif
}
}
/**
* Wrapper for getenv().
*
* @param varname name of environment variable
* @returns value of environment variable or #NULL if unset
*/
const char*
_dbus_getenv (const char *varname)
{
return getenv (varname);
}
/** @} */
/**
* @addtogroup DBusString
*
* @{
*/
/**
* Appends an integer to a DBusString.
*
* @param str the string
* @param value the integer value
* @returns #FALSE if not enough memory or other failure.
*/
dbus_bool_t
_dbus_string_append_int (DBusString *str,
long value)
{
/* this calculation is from comp.lang.c faq */
#define MAX_LONG_LEN ((sizeof (long) * 8 + 2) / 3 + 1) /* +1 for '-' */
int orig_len;
int i;
char *buf;
orig_len = _dbus_string_get_length (str);
if (!_dbus_string_lengthen (str, MAX_LONG_LEN))
return FALSE;
buf = _dbus_string_get_data_len (str, orig_len, MAX_LONG_LEN);
snprintf (buf, MAX_LONG_LEN, "%ld", value);
i = 0;
while (*buf)
{
++buf;
++i;
}
_dbus_string_shorten (str, MAX_LONG_LEN - i);
return TRUE;
}
/**
* Appends an unsigned integer to a DBusString.
*
* @param str the string
* @param value the integer value
* @returns #FALSE if not enough memory or other failure.
*/
dbus_bool_t
_dbus_string_append_uint (DBusString *str,
unsigned long value)
{
/* this is wrong, but definitely on the high side. */
#define MAX_ULONG_LEN (MAX_LONG_LEN * 2)
int orig_len;
int i;
char *buf;
orig_len = _dbus_string_get_length (str);
if (!_dbus_string_lengthen (str, MAX_ULONG_LEN))
return FALSE;
buf = _dbus_string_get_data_len (str, orig_len, MAX_ULONG_LEN);
snprintf (buf, MAX_ULONG_LEN, "%lu", value);
i = 0;
while (*buf)
{
++buf;
++i;
}
_dbus_string_shorten (str, MAX_ULONG_LEN - i);
return TRUE;
}
#ifdef DBUS_BUILD_TESTS
/**
* Appends a double to a DBusString.
*
* @param str the string
* @param value the floating point value
* @returns #FALSE if not enough memory or other failure.
*/
dbus_bool_t
_dbus_string_append_double (DBusString *str,
double value)
{
#define MAX_DOUBLE_LEN 64 /* this is completely made up :-/ */
int orig_len;
char *buf;
int i;
orig_len = _dbus_string_get_length (str);
if (!_dbus_string_lengthen (str, MAX_DOUBLE_LEN))
return FALSE;
buf = _dbus_string_get_data_len (str, orig_len, MAX_DOUBLE_LEN);
snprintf (buf, MAX_LONG_LEN, "%g", value);
i = 0;
while (*buf)
{
++buf;
++i;
}
_dbus_string_shorten (str, MAX_DOUBLE_LEN - i);
return TRUE;
}
#endif /* DBUS_BUILD_TESTS */
/**
* Parses an integer contained in a DBusString. Either return parameter
* may be #NULL if you aren't interested in it. The integer is parsed
* and stored in value_return. Return parameters are not initialized
* if the function returns #FALSE.
*
* @param str the string
* @param start the byte index of the start of the integer
* @param value_return return location of the integer value or #NULL
* @param end_return return location of the end of the integer, or #NULL
* @returns #TRUE on success
*/
dbus_bool_t
_dbus_string_parse_int (const DBusString *str,
int start,
long *value_return,
int *end_return)
{
long v;
const char *p;
char *end;
p = _dbus_string_get_const_data_len (str, start,
_dbus_string_get_length (str) - start);
end = NULL;
errno = 0;
v = strtol (p, &end, 0);
if (end == NULL || end == p || errno != 0)
return FALSE;
if (value_return)
*value_return = v;
if (end_return)
*end_return = start + (end - p);
return TRUE;
}
/**
* Parses an unsigned integer contained in a DBusString. Either return
* parameter may be #NULL if you aren't interested in it. The integer
* is parsed and stored in value_return. Return parameters are not
* initialized if the function returns #FALSE.
*
* @param str the string
* @param start the byte index of the start of the integer
* @param value_return return location of the integer value or #NULL
* @param end_return return location of the end of the integer, or #NULL
* @returns #TRUE on success
*/
dbus_bool_t
_dbus_string_parse_uint (const DBusString *str,
int start,
unsigned long *value_return,
int *end_return)
{
unsigned long v;
const char *p;
char *end;
p = _dbus_string_get_const_data_len (str, start,
_dbus_string_get_length (str) - start);
end = NULL;
errno = 0;
v = strtoul (p, &end, 0);
if (end == NULL || end == p || errno != 0)
return FALSE;
if (value_return)
*value_return = v;
if (end_return)
*end_return = start + (end - p);
return TRUE;
}
#ifdef DBUS_BUILD_TESTS
static dbus_bool_t
ascii_isspace (char c)
{
return (c == ' ' ||
c == '\f' ||
c == '\n' ||
c == '\r' ||
c == '\t' ||
c == '\v');
}
#endif /* DBUS_BUILD_TESTS */
#ifdef DBUS_BUILD_TESTS
static dbus_bool_t
ascii_isdigit (char c)
{
return c >= '0' && c <= '9';
}
#endif /* DBUS_BUILD_TESTS */
#ifdef DBUS_BUILD_TESTS
static dbus_bool_t
ascii_isxdigit (char c)
{
return (ascii_isdigit (c) ||
(c >= 'a' && c <= 'f') ||
(c >= 'A' && c <= 'F'));
}
#endif /* DBUS_BUILD_TESTS */
#ifdef DBUS_BUILD_TESTS
/* Calls strtod in a locale-independent fashion, by looking at
* the locale data and patching the decimal comma to a point.
*
* Relicensed from glib.
*/
static double
ascii_strtod (const char *nptr,
char **endptr)
{
char *fail_pos;
double val;
struct lconv *locale_data;
const char *decimal_point;
int decimal_point_len;
const char *p, *decimal_point_pos;
const char *end = NULL; /* Silence gcc */
fail_pos = NULL;
locale_data = localeconv ();
decimal_point = locale_data->decimal_point;
decimal_point_len = strlen (decimal_point);
_dbus_assert (decimal_point_len != 0);
decimal_point_pos = NULL;
if (decimal_point[0] != '.' ||
decimal_point[1] != 0)
{
p = nptr;
/* Skip leading space */
while (ascii_isspace (*p))
p++;
/* Skip leading optional sign */
if (*p == '+' || *p == '-')
p++;
if (p[0] == '0' &&
(p[1] == 'x' || p[1] == 'X'))
{
p += 2;
/* HEX - find the (optional) decimal point */
while (ascii_isxdigit (*p))
p++;
if (*p == '.')
{
decimal_point_pos = p++;
while (ascii_isxdigit (*p))
p++;
if (*p == 'p' || *p == 'P')
p++;
if (*p == '+' || *p == '-')
p++;
while (ascii_isdigit (*p))
p++;
end = p;
}
}
else
{
while (ascii_isdigit (*p))
p++;
if (*p == '.')
{
decimal_point_pos = p++;
while (ascii_isdigit (*p))
p++;
if (*p == 'e' || *p == 'E')
p++;
if (*p == '+' || *p == '-')
p++;
while (ascii_isdigit (*p))
p++;
end = p;
}
}
/* For the other cases, we need not convert the decimal point */
}
/* Set errno to zero, so that we can distinguish zero results
and underflows */
errno = 0;
if (decimal_point_pos)
{
char *copy, *c;
/* We need to convert the '.' to the locale specific decimal point */
copy = dbus_malloc (end - nptr + 1 + decimal_point_len);
c = copy;
memcpy (c, nptr, decimal_point_pos - nptr);
c += decimal_point_pos - nptr;
memcpy (c, decimal_point, decimal_point_len);
c += decimal_point_len;
memcpy (c, decimal_point_pos + 1, end - (decimal_point_pos + 1));
c += end - (decimal_point_pos + 1);
*c = 0;
val = strtod (copy, &fail_pos);
if (fail_pos)
{
if (fail_pos > decimal_point_pos)
fail_pos = (char *)nptr + (fail_pos - copy) - (decimal_point_len - 1);
else
fail_pos = (char *)nptr + (fail_pos - copy);
}
dbus_free (copy);
}
else
val = strtod (nptr, &fail_pos);
if (endptr)
*endptr = fail_pos;
return val;
}
#endif /* DBUS_BUILD_TESTS */
#ifdef DBUS_BUILD_TESTS
/**
* Parses a floating point number contained in a DBusString. Either
* return parameter may be #NULL if you aren't interested in it. The
* integer is parsed and stored in value_return. Return parameters are
* not initialized if the function returns #FALSE.
*
* @param str the string
* @param start the byte index of the start of the float
* @param value_return return location of the float value or #NULL
* @param end_return return location of the end of the float, or #NULL
* @returns #TRUE on success
*/
dbus_bool_t
_dbus_string_parse_double (const DBusString *str,
int start,
double *value_return,
int *end_return)
{
double v;
const char *p;
char *end;
p = _dbus_string_get_const_data_len (str, start,
_dbus_string_get_length (str) - start);
end = NULL;
errno = 0;
v = ascii_strtod (p, &end);
if (end == NULL || end == p || errno != 0)
return FALSE;
if (value_return)
*value_return = v;
if (end_return)
*end_return = start + (end - p);
return TRUE;
}
#endif /* DBUS_BUILD_TESTS */
/** @} */ /* DBusString group */
/**
* @addtogroup DBusInternalsUtils
* @{
*/
/**
* Frees the members of info
* (but not info itself)
* @param info the user info struct
*/
void
_dbus_user_info_free (DBusUserInfo *info)
{
dbus_free (info->group_ids);
dbus_free (info->username);
dbus_free (info->homedir);
}
/**
* Frees the members of info (but not info itself).
*
* @param info the group info
*/
void
_dbus_group_info_free (DBusGroupInfo *info)
{
dbus_free (info->groupname);
}
/**
* Sets fields in DBusCredentials to DBUS_PID_UNSET,
* DBUS_UID_UNSET, DBUS_GID_UNSET.
*
* @param credentials the credentials object to fill in
*/
void
_dbus_credentials_clear (DBusCredentials *credentials)
{
credentials->pid = DBUS_PID_UNSET;
credentials->uid = DBUS_UID_UNSET;
credentials->gid = DBUS_GID_UNSET;
}
/**
* Checks whether the provided_credentials are allowed to log in
* as the expected_credentials.
*
* @param expected_credentials credentials we're trying to log in as
* @param provided_credentials credentials we have
* @returns #TRUE if we can log in
*/
dbus_bool_t
_dbus_credentials_match (const DBusCredentials *expected_credentials,
const DBusCredentials *provided_credentials)
{
if (provided_credentials->uid == DBUS_UID_UNSET)
return FALSE;
else if (expected_credentials->uid == DBUS_UID_UNSET)
return FALSE;
else if (provided_credentials->uid == 0)
return TRUE;
else if (provided_credentials->uid == expected_credentials->uid)
return TRUE;
else
return FALSE;
}
_DBUS_DEFINE_GLOBAL_LOCK (atomic);
#ifdef DBUS_USE_ATOMIC_INT_486
/* Taken from CVS version 1.7 of glibc's sysdeps/i386/i486/atomicity.h */
/* Since the asm stuff here is gcc-specific we go ahead and use "inline" also */
static inline dbus_int32_t
atomic_exchange_and_add (DBusAtomic *atomic,
volatile dbus_int32_t val)
{
register dbus_int32_t result;
__asm__ __volatile__ ("lock; xaddl %0,%1"
: "=r" (result), "=m" (atomic->value)
: "0" (val), "m" (atomic->value));
return result;
}
#endif
/**
* Atomically increments an integer
*
* @param atomic pointer to the integer to increment
* @returns the value before incrementing
*
* @todo implement arch-specific faster atomic ops
*/
dbus_int32_t
_dbus_atomic_inc (DBusAtomic *atomic)
{
#ifdef DBUS_USE_ATOMIC_INT_486
return atomic_exchange_and_add (atomic, 1);
#else
dbus_int32_t res;
_DBUS_LOCK (atomic);
res = atomic->value;
atomic->value += 1;
_DBUS_UNLOCK (atomic);
return res;
#endif
}
/**
* Atomically decrement an integer
*
* @param atomic pointer to the integer to decrement
* @returns the value before decrementing
*
* @todo implement arch-specific faster atomic ops
*/
dbus_int32_t
_dbus_atomic_dec (DBusAtomic *atomic)
{
#ifdef DBUS_USE_ATOMIC_INT_486
return atomic_exchange_and_add (atomic, -1);
#else
dbus_int32_t res;
_DBUS_LOCK (atomic);
res = atomic->value;
atomic->value -= 1;
_DBUS_UNLOCK (atomic);
return res;
#endif
}
void
_dbus_generate_pseudorandom_bytes_buffer (char *buffer,
int n_bytes)
{
long tv_usec;
int i;
/* fall back to pseudorandom */
_dbus_verbose ("Falling back to pseudorandom for %d bytes\n",
n_bytes);
_dbus_get_current_time (NULL, &tv_usec);
srand (tv_usec);
i = 0;
while (i < n_bytes)
{
double r;
unsigned int b;
r = rand ();
b = (r / (double) RAND_MAX) * 255.0;
buffer[i] = b;
++i;
}
}
/**
* Fills n_bytes of the given buffer with random bytes.
*
* @param buffer an allocated buffer
* @param n_bytes the number of bytes in buffer to write to
*/
void
_dbus_generate_random_bytes_buffer (char *buffer,
int n_bytes)
{
DBusString str;
if (!_dbus_string_init (&str))
{
_dbus_generate_pseudorandom_bytes_buffer (buffer, n_bytes);
return;
}
if (!_dbus_generate_random_bytes (&str, n_bytes))
{
_dbus_string_free (&str);
_dbus_generate_pseudorandom_bytes_buffer (buffer, n_bytes);
return;
}
_dbus_string_copy_to_buffer (&str, buffer, n_bytes);
_dbus_string_free (&str);
}
/**
* Generates the given number of random bytes, where the bytes are
* chosen from the alphanumeric ASCII subset.
*
* @param str the string
* @param n_bytes the number of random ASCII bytes to append to string
* @returns #TRUE on success, #FALSE if no memory or other failure
*/
dbus_bool_t
_dbus_generate_random_ascii (DBusString *str,
int n_bytes)
{
static const char letters[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";
int i;
int len;
if (!_dbus_generate_random_bytes (str, n_bytes))
return FALSE;
len = _dbus_string_get_length (str);
i = len - n_bytes;
while (i < len)
{
_dbus_string_set_byte (str, i,
letters[_dbus_string_get_byte (str, i) %
(sizeof (letters) - 1)]);
++i;
}
_dbus_assert (_dbus_string_validate_ascii (str, len - n_bytes,
n_bytes));
return TRUE;
}
/**
* Gets a UID from a UID string.
*
* @param uid_str the UID in string form
* @param uid UID to fill in
* @returns #TRUE if successfully filled in UID
*/
dbus_bool_t
_dbus_parse_uid (const DBusString *uid_str,
dbus_uid_t *uid)
{
int end;
long val;
if (_dbus_string_get_length (uid_str) == 0)
{
_dbus_verbose ("UID string was zero length\n");
return FALSE;
}
val = -1;
end = 0;
if (!_dbus_string_parse_int (uid_str, 0, &val,
&end))
{
_dbus_verbose ("could not parse string as a UID\n");
return FALSE;
}
if (end != _dbus_string_get_length (uid_str))
{
_dbus_verbose ("string contained trailing stuff after UID\n");
return FALSE;
}
*uid = val;
return TRUE;
}
/**
* Converts a UNIX or Windows errno
* into a #DBusError name.
*
* @todo should cover more errnos, specifically those
* from open().
*
* @param error_number the errno.
* @returns an error name
*/
const char*
_dbus_error_from_errno (int error_number)
{
switch (error_number)
{
case 0:
return DBUS_ERROR_FAILED;
#ifdef EPROTONOSUPPORT
case EPROTONOSUPPORT:
return DBUS_ERROR_NOT_SUPPORTED;
#endif
#ifdef EAFNOSUPPORT
case EAFNOSUPPORT:
return DBUS_ERROR_NOT_SUPPORTED;
#endif
#ifdef ENFILE
case ENFILE:
return DBUS_ERROR_LIMITS_EXCEEDED; /* kernel out of memory */
#endif
#ifdef EMFILE
case EMFILE:
return DBUS_ERROR_LIMITS_EXCEEDED;
#endif
#ifdef EACCES
case EACCES:
return DBUS_ERROR_ACCESS_DENIED;
#endif
#ifdef EPERM
case EPERM:
return DBUS_ERROR_ACCESS_DENIED;
#endif
#ifdef ENOBUFS
case ENOBUFS:
return DBUS_ERROR_NO_MEMORY;
#endif
#ifdef ENOMEM
case ENOMEM:
return DBUS_ERROR_NO_MEMORY;
#endif
#ifdef EINVAL
case EINVAL:
return DBUS_ERROR_FAILED;
#endif
#ifdef EBADF
case EBADF:
return DBUS_ERROR_FAILED;
#endif
#ifdef EFAULT
case EFAULT:
return DBUS_ERROR_FAILED;
#endif
#ifdef ENOTSOCK
case ENOTSOCK:
return DBUS_ERROR_FAILED;
#endif
#ifdef EISCONN
case EISCONN:
return DBUS_ERROR_FAILED;
#endif
#ifdef ECONNREFUSED
case ECONNREFUSED:
return DBUS_ERROR_NO_SERVER;
#endif
#ifdef ETIMEDOUT
case ETIMEDOUT:
return DBUS_ERROR_TIMEOUT;
#endif
#ifdef ENETUNREACH
case ENETUNREACH:
return DBUS_ERROR_NO_NETWORK;
#endif
#ifdef EADDRINUSE
case EADDRINUSE:
return DBUS_ERROR_ADDRESS_IN_USE;
#endif
#ifdef EEXIST
case EEXIST:
return DBUS_ERROR_FILE_EXISTS;
#endif
#ifdef ENOENT
case ENOENT:
return DBUS_ERROR_FILE_NOT_FOUND;
#endif
}
return DBUS_ERROR_FAILED;
}
/** @} end of sysdeps */
/* tests in dbus-sysdeps-util.c */