diff options
Diffstat (limited to 'dbus/dbus-sysdeps-util-unix.c')
| -rw-r--r-- | dbus/dbus-sysdeps-util-unix.c | 740 |
1 files changed, 740 insertions, 0 deletions
diff --git a/dbus/dbus-sysdeps-util-unix.c b/dbus/dbus-sysdeps-util-unix.c new file mode 100644 index 00000000..404be44b --- /dev/null +++ b/dbus/dbus-sysdeps-util-unix.c @@ -0,0 +1,740 @@ +/* -*- mode: C; c-file-style: "gnu" -*- */ +/* dbus-sysdeps-util-unix.c Would be in dbus-sysdeps-unix.c, but not used in libdbus + * + * Copyright (C) 2002, 2003, 2004, 2005 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-sysdeps.h" +#include "dbus-internals.h" +#include "dbus-protocol.h" +#include "dbus-string.h" +#define DBUS_USERDB_INCLUDES_PRIVATE 1 +#include "dbus-userdb.h" +#include "dbus-test.h" + +#include <sys/types.h> +#include <stdlib.h> +#include <string.h> +#include <signal.h> +#include <unistd.h> +#include <stdio.h> +#include <errno.h> +#include <fcntl.h> +#include <sys/stat.h> +#include <grp.h> +#include <sys/socket.h> +#include <dirent.h> +#include <sys/un.h> + +#ifndef O_BINARY +#define O_BINARY 0 +#endif + +/** + * @addtogroup DBusInternalsUtils + * @{ + */ + +/** + * Does the chdir, fork, setsid, etc. to become a daemon process. + * + * @param pidfile #NULL, or pidfile to create + * @param print_pid_fd file descriptor to print daemon's pid to, or -1 for none + * @param error return location for errors + * @returns #FALSE on failure + */ +dbus_bool_t +_dbus_become_daemon (const DBusString *pidfile, + int print_pid_fd, + DBusError *error) +{ + const char *s; + pid_t child_pid; + int dev_null_fd; + + _dbus_verbose ("Becoming a daemon...\n"); + + _dbus_verbose ("chdir to /\n"); + if (chdir ("/") < 0) + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "Could not chdir() to root directory"); + return FALSE; + } + + _dbus_verbose ("forking...\n"); + switch ((child_pid = fork ())) + { + case -1: + _dbus_verbose ("fork failed\n"); + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to fork daemon: %s", _dbus_strerror (errno)); + return FALSE; + break; + + case 0: + _dbus_verbose ("in child, closing std file descriptors\n"); + + /* silently ignore failures here, if someone + * doesn't have /dev/null we may as well try + * to continue anyhow + */ + + dev_null_fd = open ("/dev/null", O_RDWR); + if (dev_null_fd >= 0) + { + dup2 (dev_null_fd, 0); + dup2 (dev_null_fd, 1); + + s = _dbus_getenv ("DBUS_DEBUG_OUTPUT"); + if (s == NULL || *s == '\0') + dup2 (dev_null_fd, 2); + else + _dbus_verbose ("keeping stderr open due to DBUS_DEBUG_OUTPUT\n"); + } + + /* Get a predictable umask */ + _dbus_verbose ("setting umask\n"); + umask (022); + break; + + default: + if (pidfile) + { + _dbus_verbose ("parent writing pid file\n"); + if (!_dbus_write_pid_file (pidfile, + child_pid, + error)) + { + _dbus_verbose ("pid file write failed, killing child\n"); + kill (child_pid, SIGTERM); + return FALSE; + } + } + + /* Write PID if requested */ + if (print_pid_fd >= 0) + { + DBusString pid; + int bytes; + + if (!_dbus_string_init (&pid)) + { + _DBUS_SET_OOM (error); + kill (child_pid, SIGTERM); + return FALSE; + } + + if (!_dbus_string_append_int (&pid, child_pid) || + !_dbus_string_append (&pid, "\n")) + { + _dbus_string_free (&pid); + _DBUS_SET_OOM (error); + kill (child_pid, SIGTERM); + return FALSE; + } + + bytes = _dbus_string_get_length (&pid); + if (_dbus_write (print_pid_fd, &pid, 0, bytes) != bytes) + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "Printing message bus PID: %s\n", + _dbus_strerror (errno)); + _dbus_string_free (&pid); + kill (child_pid, SIGTERM); + return FALSE; + } + + _dbus_string_free (&pid); + } + _dbus_verbose ("parent exiting\n"); + _exit (0); + break; + } + + _dbus_verbose ("calling setsid()\n"); + if (setsid () == -1) + _dbus_assert_not_reached ("setsid() failed"); + + return TRUE; +} + + +/** + * Creates a file containing the process ID. + * + * @param filename the filename to write to + * @param pid our process ID + * @param error return location for errors + * @returns #FALSE on failure + */ +dbus_bool_t +_dbus_write_pid_file (const DBusString *filename, + unsigned long pid, + DBusError *error) +{ + const char *cfilename; + int fd; + FILE *f; + + cfilename = _dbus_string_get_const_data (filename); + + fd = open (cfilename, O_WRONLY|O_CREAT|O_EXCL|O_BINARY, 0644); + + if (fd < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to open \"%s\": %s", cfilename, + _dbus_strerror (errno)); + return FALSE; + } + + if ((f = fdopen (fd, "w")) == NULL) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to fdopen fd %d: %s", fd, _dbus_strerror (errno)); + close (fd); + return FALSE; + } + + if (fprintf (f, "%lu\n", pid) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to write to \"%s\": %s", cfilename, + _dbus_strerror (errno)); + + fclose (f); + return FALSE; + } + + if (fclose (f) == EOF) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to close \"%s\": %s", cfilename, + _dbus_strerror (errno)); + return FALSE; + } + + return TRUE; +} + + +/** + * Changes the user and group the bus is running as. + * + * @param uid the new user ID + * @param gid the new group ID + * @param error return location for errors + * @returns #FALSE on failure + */ +dbus_bool_t +_dbus_change_identity (dbus_uid_t uid, + dbus_gid_t gid, + DBusError *error) +{ + /* setgroups() only works if we are a privileged process, + * so we don't return error on failure; the only possible + * failure is that we don't have perms to do it. + * FIXME not sure this is right, maybe if setuid() + * is going to work then setgroups() should also work. + */ + if (setgroups (0, NULL) < 0) + _dbus_warn ("Failed to drop supplementary groups: %s\n", + _dbus_strerror (errno)); + + /* Set GID first, or the setuid may remove our permission + * to change the GID + */ + if (setgid (gid) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to set GID to %lu: %s", gid, + _dbus_strerror (errno)); + return FALSE; + } + + if (setuid (uid) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to set UID to %lu: %s", uid, + _dbus_strerror (errno)); + return FALSE; + } + + return TRUE; +} + +/** Installs a UNIX signal handler + * + * @param sig the signal to handle + * @param handler the handler + */ +void +_dbus_set_signal_handler (int sig, + DBusSignalHandler handler) +{ + struct sigaction act; + sigset_t empty_mask; + + sigemptyset (&empty_mask); + act.sa_handler = handler; + act.sa_mask = empty_mask; + act.sa_flags = 0; + sigaction (sig, &act, NULL); +} + + +/** + * Removes a directory; Directory must be empty + * + * @param filename directory filename + * @param error initialized error object + * @returns #TRUE on success + */ +dbus_bool_t +_dbus_delete_directory (const DBusString *filename, + DBusError *error) +{ + const char *filename_c; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + filename_c = _dbus_string_get_const_data (filename); + + if (rmdir (filename_c) != 0) + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "Failed to remove directory %s: %s\n", + filename_c, _dbus_strerror (errno)); + return FALSE; + } + + return TRUE; +} + +/** Checks if a file exists +* +* @param file full path to the file +* @returns #TRUE if file exists +*/ +dbus_bool_t +_dbus_file_exists (const char *file) +{ + return (access (file, F_OK) == 0); +} + +/** Checks if user is at the console +* +* @param username user to check +* @param error return location for errors +* @returns #TRUE is the user is at the consolei and there are no errors +*/ +dbus_bool_t +_dbus_user_at_console (const char *username, + DBusError *error) +{ + + DBusString f; + dbus_bool_t result; + + result = FALSE; + if (!_dbus_string_init (&f)) + { + _DBUS_SET_OOM (error); + return FALSE; + } + + if (!_dbus_string_append (&f, DBUS_CONSOLE_AUTH_DIR)) + { + _DBUS_SET_OOM (error); + goto out; + } + + + if (!_dbus_string_append (&f, username)) + { + _DBUS_SET_OOM (error); + goto out; + } + + result = _dbus_file_exists (_dbus_string_get_const_data (&f)); + + out: + _dbus_string_free (&f); + + return result; +} + + +/** + * Checks whether the filename is an absolute path + * + * @param filename the filename + * @returns #TRUE if an absolute path + */ +dbus_bool_t +_dbus_path_is_absolute (const DBusString *filename) +{ + if (_dbus_string_get_length (filename) > 0) + return _dbus_string_get_byte (filename, 0) == '/'; + else + return FALSE; +} + +/** + * stat() wrapper. + * + * @param filename the filename to stat + * @param statbuf the stat info to fill in + * @param error return location for error + * @returns #FALSE if error was set + */ +dbus_bool_t +_dbus_stat (const DBusString *filename, + DBusStat *statbuf, + DBusError *error) +{ + const char *filename_c; + struct stat sb; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + filename_c = _dbus_string_get_const_data (filename); + + if (stat (filename_c, &sb) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "%s", _dbus_strerror (errno)); + return FALSE; + } + + statbuf->mode = sb.st_mode; + statbuf->nlink = sb.st_nlink; + statbuf->uid = sb.st_uid; + statbuf->gid = sb.st_gid; + statbuf->size = sb.st_size; + statbuf->atime = sb.st_atime; + statbuf->mtime = sb.st_mtime; + statbuf->ctime = sb.st_ctime; + + return TRUE; +} + + +/** + * Internals of directory iterator + */ +struct DBusDirIter +{ + DIR *d; /**< The DIR* from opendir() */ + +}; + +/** + * Open a directory to iterate over. + * + * @param filename the directory name + * @param error exception return object or #NULL + * @returns new iterator, or #NULL on error + */ +DBusDirIter* +_dbus_directory_open (const DBusString *filename, + DBusError *error) +{ + DIR *d; + DBusDirIter *iter; + const char *filename_c; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + filename_c = _dbus_string_get_const_data (filename); + + d = opendir (filename_c); + if (d == NULL) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to read directory \"%s\": %s", + filename_c, + _dbus_strerror (errno)); + return NULL; + } + iter = dbus_new0 (DBusDirIter, 1); + if (iter == NULL) + { + closedir (d); + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, + "Could not allocate memory for directory iterator"); + return NULL; + } + + iter->d = d; + + return iter; +} + +/** + * Get next file in the directory. Will not return "." or ".." on + * UNIX. If an error occurs, the contents of "filename" are + * undefined. The error is never set if the function succeeds. + * + * @todo for thread safety, I think we have to use + * readdir_r(). (GLib has the same issue, should file a bug.) + * + * @param iter the iterator + * @param filename string to be set to the next file in the dir + * @param error return location for error + * @returns #TRUE if filename was filled in with a new filename + */ +dbus_bool_t +_dbus_directory_get_next_file (DBusDirIter *iter, + DBusString *filename, + DBusError *error) +{ + struct dirent *ent; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + again: + errno = 0; + ent = readdir (iter->d); + if (ent == NULL) + { + if (errno != 0) + dbus_set_error (error, + _dbus_error_from_errno (errno), + "%s", _dbus_strerror (errno)); + return FALSE; + } + else if (ent->d_name[0] == '.' && + (ent->d_name[1] == '\0' || + (ent->d_name[1] == '.' && ent->d_name[2] == '\0'))) + goto again; + else + { + _dbus_string_set_length (filename, 0); + if (!_dbus_string_append (filename, ent->d_name)) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, + "No memory to read directory entry"); + return FALSE; + } + else + return TRUE; + } +} + +/** + * Closes a directory iteration. + */ +void +_dbus_directory_close (DBusDirIter *iter) +{ + closedir (iter->d); + dbus_free (iter); +} + +static dbus_bool_t +fill_user_info_from_group (struct group *g, + DBusGroupInfo *info, + DBusError *error) +{ + _dbus_assert (g->gr_name != NULL); + + info->gid = g->gr_gid; + info->groupname = _dbus_strdup (g->gr_name); + + /* info->members = dbus_strdupv (g->gr_mem) */ + + if (info->groupname == NULL) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + return FALSE; + } + + return TRUE; +} + +static dbus_bool_t +fill_group_info (DBusGroupInfo *info, + dbus_gid_t gid, + const DBusString *groupname, + DBusError *error) +{ + const char *group_c_str; + + _dbus_assert (groupname != NULL || gid != DBUS_GID_UNSET); + _dbus_assert (groupname == NULL || gid == DBUS_GID_UNSET); + + if (groupname) + group_c_str = _dbus_string_get_const_data (groupname); + else + group_c_str = NULL; + + /* For now assuming that the getgrnam() and getgrgid() flavors + * always correspond to the pwnam flavors, if not we have + * to add more configure checks. + */ + +#if defined (HAVE_POSIX_GETPWNAM_R) || defined (HAVE_NONPOSIX_GETPWNAM_R) + { + struct group *g; + int result; + char buf[1024]; + struct group g_str; + + g = NULL; +#ifdef HAVE_POSIX_GETPWNAM_R + + if (group_c_str) + result = getgrnam_r (group_c_str, &g_str, buf, sizeof (buf), + &g); + else + result = getgrgid_r (gid, &g_str, buf, sizeof (buf), + &g); +#else + g = getgrnam_r (group_c_str, &g_str, buf, sizeof (buf)); + result = 0; +#endif /* !HAVE_POSIX_GETPWNAM_R */ + if (result == 0 && g == &g_str) + { + return fill_user_info_from_group (g, info, error); + } + else + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Group %s unknown or failed to look it up\n", + group_c_str ? group_c_str : "???"); + return FALSE; + } + } +#else /* ! HAVE_GETPWNAM_R */ + { + /* I guess we're screwed on thread safety here */ + struct group *g; + + g = getgrnam (group_c_str); + + if (g != NULL) + { + return fill_user_info_from_group (g, info, error); + } + else + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Group %s unknown or failed to look it up\n", + group_c_str ? group_c_str : "???"); + return FALSE; + } + } +#endif /* ! HAVE_GETPWNAM_R */ +} + +/** + * Initializes the given DBusGroupInfo struct + * with information about the given group name. + * + * @param info the group info struct + * @param groupname name of group + * @param error the error return + * @returns #FALSE if error is set + */ +dbus_bool_t +_dbus_group_info_fill (DBusGroupInfo *info, + const DBusString *groupname, + DBusError *error) +{ + return fill_group_info (info, DBUS_GID_UNSET, + groupname, error); + +} + +/** + * Initializes the given DBusGroupInfo struct + * with information about the given group ID. + * + * @param info the group info struct + * @param gid group ID + * @param error the error return + * @returns #FALSE if error is set + */ +dbus_bool_t +_dbus_group_info_fill_gid (DBusGroupInfo *info, + dbus_gid_t gid, + DBusError *error) +{ + return fill_group_info (info, gid, NULL, error); +} + +/** @} */ /* End of DBusInternalsUtils functions */ + +/** + * @addtogroup DBusString + * + * @{ + */ +/** + * Get the directory name from a complete filename + * @param filename the filename + * @param dirname string to append directory name to + * @returns #FALSE if no memory + */ +dbus_bool_t +_dbus_string_get_dirname (const DBusString *filename, + DBusString *dirname) +{ + int sep; + + _dbus_assert (filename != dirname); + _dbus_assert (filename != NULL); + _dbus_assert (dirname != NULL); + + /* Ignore any separators on the end */ + sep = _dbus_string_get_length (filename); + if (sep == 0) + return _dbus_string_append (dirname, "."); /* empty string passed in */ + + while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/') + --sep; + + _dbus_assert (sep >= 0); + + if (sep == 0) + return _dbus_string_append (dirname, "/"); + + /* Now find the previous separator */ + _dbus_string_find_byte_backward (filename, sep, '/', &sep); + if (sep < 0) + return _dbus_string_append (dirname, "."); + + /* skip multiple separators */ + while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/') + --sep; + + _dbus_assert (sep >= 0); + + if (sep == 0 && + _dbus_string_get_byte (filename, 0) == '/') + return _dbus_string_append (dirname, "/"); + else + return _dbus_string_copy_len (filename, 0, sep - 0, + dirname, _dbus_string_get_length (dirname)); +} +/** @} */ /* DBusString stuff */ + |