/* -*- 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 #include #include #include /* 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 #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 */