*
* 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
+
+#include <config.h>
#include "dbus-sysdeps.h"
#include "dbus-sysdeps-unix.h"
#include "dbus-internals.h"
+#include "dbus-pipe.h"
#include "dbus-protocol.h"
#include "dbus-string.h"
#define DBUS_USERDB_INCLUDES_PRIVATE 1
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
#include <grp.h>
#include <sys/socket.h>
#include <dirent.h>
#include <sys/un.h>
-#ifdef HAVE_LIBAUDIT
-#include <sys/prctl.h>
-#include <sys/capability.h>
-#include <libaudit.h>
-#endif /* HAVE_LIBAUDIT */
+#include <syslog.h>
#ifdef HAVE_SYS_SYSLIMITS_H
#include <sys/syslimits.h>
* @param pidfile #NULL, or pidfile to create
* @param print_pid_pipe pipe to print daemon's pid to, or -1 for none
* @param error return location for errors
+ * @param keep_umask #TRUE to keep the original umask
* @returns #FALSE on failure
*/
dbus_bool_t
_dbus_become_daemon (const DBusString *pidfile,
DBusPipe *print_pid_pipe,
- DBusError *error)
+ DBusError *error,
+ dbus_bool_t keep_umask)
{
const char *s;
pid_t child_pid;
_dbus_verbose ("keeping stderr open due to DBUS_DEBUG_OUTPUT\n");
}
- /* Get a predictable umask */
- _dbus_verbose ("setting umask\n");
- umask (022);
+ if (!keep_umask)
+ {
+ /* Get a predictable umask */
+ _dbus_verbose ("setting umask\n");
+ umask (022);
+ }
_dbus_verbose ("calling setsid()\n");
if (setsid () == -1)
DBusString pid;
int bytes;
- _dbus_verbose ("writing our pid to pipe %d\n", print_pid_pipe->fd_or_handle);
+ _dbus_verbose ("writing our pid to pipe %"PRIuPTR"\n",
+ print_pid_pipe->fd_or_handle);
if (!_dbus_string_init (&pid))
{
return _dbus_get_user_id_and_primary_group (&u, NULL, NULL);
}
+
+/* The HAVE_LIBAUDIT case lives in selinux.c */
+#ifndef HAVE_LIBAUDIT
/**
* Changes the user and group the bus is running as.
*
dbus_uid_t uid;
dbus_gid_t gid;
DBusString u;
-#ifdef HAVE_LIBAUDIT
- dbus_bool_t we_were_root;
- cap_t new_caps;
-#endif
-
+
_dbus_string_init_const (&u, user);
-
+
if (!_dbus_get_user_id_and_primary_group (&u, &uid, &gid))
{
dbus_set_error (error, DBUS_ERROR_FAILED,
user);
return FALSE;
}
-
-#ifdef HAVE_LIBAUDIT
- we_were_root = _dbus_getuid () == 0;
- new_caps = NULL;
- /* have a tmp set of caps that we use to transition to the usr/grp dbus should
- * run as ... doesn't really help. But keeps people happy.
- */
-
- if (!we_were_root)
- {
- cap_value_t new_cap_list[] = { CAP_AUDIT_WRITE };
- cap_value_t tmp_cap_list[] = { CAP_AUDIT_WRITE, CAP_SETUID, CAP_SETGID };
- cap_t tmp_caps = cap_init();
-
- if (!tmp_caps || !(new_caps = cap_init ()))
- {
- dbus_set_error (error, DBUS_ERROR_FAILED,
- "Failed to initialize drop of capabilities: %s\n",
- _dbus_strerror (errno));
-
- if (tmp_caps)
- cap_free (tmp_caps);
- return FALSE;
- }
-
- /* assume these work... */
- cap_set_flag (new_caps, CAP_PERMITTED, 1, new_cap_list, CAP_SET);
- cap_set_flag (new_caps, CAP_EFFECTIVE, 1, new_cap_list, CAP_SET);
- cap_set_flag (tmp_caps, CAP_PERMITTED, 3, tmp_cap_list, CAP_SET);
- cap_set_flag (tmp_caps, CAP_EFFECTIVE, 3, tmp_cap_list, CAP_SET);
-
- if (prctl (PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1)
- {
- dbus_set_error (error, _dbus_error_from_errno (errno),
- "Failed to set keep-capabilities: %s\n",
- _dbus_strerror (errno));
- cap_free (tmp_caps);
- goto fail;
- }
-
- if (cap_set_proc (tmp_caps) == -1)
- {
- dbus_set_error (error, DBUS_ERROR_FAILED,
- "Failed to drop capabilities: %s\n",
- _dbus_strerror (errno));
- cap_free (tmp_caps);
- goto fail;
- }
- cap_free (tmp_caps);
- }
-#endif /* HAVE_LIBAUDIT */
-
/* 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.
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
*/
dbus_set_error (error, _dbus_error_from_errno (errno),
"Failed to set GID to %lu: %s", gid,
_dbus_strerror (errno));
- goto fail;
+ 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));
- goto fail;
+ return FALSE;
}
-
-#ifdef HAVE_LIBAUDIT
- if (!we_were_root)
- {
- if (cap_set_proc (new_caps))
- {
- dbus_set_error (error, DBUS_ERROR_FAILED,
- "Failed to drop capabilities: %s\n",
- _dbus_strerror (errno));
- goto fail;
- }
- cap_free (new_caps);
- /* should always work, if it did above */
- if (prctl (PR_SET_KEEPCAPS, 0, 0, 0, 0) == -1)
- {
- dbus_set_error (error, _dbus_error_from_errno (errno),
- "Failed to unset keep-capabilities: %s\n",
- _dbus_strerror (errno));
- return FALSE;
- }
- }
-#endif
+ return TRUE;
+}
+#endif /* !HAVE_LIBAUDIT */
+
+
+/**
+ * Attempt to ensure that the current process can open
+ * at least @limit file descriptors.
+ *
+ * If @limit is lower than the current, it will not be
+ * lowered. No error is returned if the request can
+ * not be satisfied.
+ *
+ * @limit Number of file descriptors
+ */
+void
+_dbus_request_file_descriptor_limit (unsigned int limit)
+{
+#ifdef HAVE_SETRLIMIT
+ struct rlimit lim;
+ struct rlimit target_lim;
+ unsigned int current_limit;
+
+ /* No point to doing this practically speaking
+ * if we're not uid 0. We expect the system
+ * bus to use this before we change UID, and
+ * the session bus takes the Linux default
+ * of 1024 for both cur and max.
+ */
+ if (getuid () != 0)
+ return;
+
+ if (getrlimit (RLIMIT_NOFILE, &lim) < 0)
+ return;
- return TRUE;
+ if (lim.rlim_cur >= limit)
+ return;
- fail:
-#ifdef HAVE_LIBAUDIT
- if (!we_were_root)
- {
- /* should always work, if it did above */
- prctl (PR_SET_KEEPCAPS, 0, 0, 0, 0);
- cap_free (new_caps);
- }
+ /* Ignore "maximum limit", assume we have the "superuser"
+ * privileges. On Linux this is CAP_SYS_RESOURCE.
+ */
+ target_lim.rlim_cur = target_lim.rlim_max = limit;
+ /* Also ignore errors; if we fail, we will at least work
+ * up to whatever limit we had, which seems better than
+ * just outright aborting.
+ *
+ * However, in the future we should probably log this so OS builders
+ * have a chance to notice any misconfiguration like dbus-daemon
+ * being started without CAP_SYS_RESOURCE.
+ */
+ setrlimit (RLIMIT_NOFILE, &target_lim);
#endif
+}
+
+void
+_dbus_init_system_log (void)
+{
+ openlog ("dbus", LOG_PID, LOG_DAEMON);
+}
+/**
+ * Log a message to the system log file (e.g. syslog on Unix).
+ *
+ * @param severity a severity value
+ * @param msg a printf-style format string
+ * @param args arguments for the format string
+ *
+ */
+void
+_dbus_system_log (DBusSystemLogSeverity severity, const char *msg, ...)
+{
+ va_list args;
+
+ va_start (args, msg);
+
+ _dbus_system_logv (severity, msg, args);
+
+ va_end (args);
+}
+
+/**
+ * Log a message to the system log file (e.g. syslog on Unix).
+ *
+ * @param severity a severity value
+ * @param msg a printf-style format string
+ * @param args arguments for the format string
+ *
+ * If the FATAL severity is given, this function will terminate the program
+ * with an error code.
+ */
+void
+_dbus_system_logv (DBusSystemLogSeverity severity, const char *msg, va_list args)
+{
+ int flags;
+ switch (severity)
+ {
+ case DBUS_SYSTEM_LOG_INFO:
+ flags = LOG_DAEMON | LOG_NOTICE;
+ break;
+ case DBUS_SYSTEM_LOG_SECURITY:
+ flags = LOG_AUTH | LOG_NOTICE;
+ break;
+ case DBUS_SYSTEM_LOG_FATAL:
+ flags = LOG_DAEMON|LOG_CRIT;
+ break;
+ default:
+ return;
+ }
+
+ vsyslog (flags, msg, args);
- return FALSE;
+ if (severity == DBUS_SYSTEM_LOG_FATAL)
+ exit (1);
}
/** Installs a UNIX signal handler
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
return iter;
}
-/* Calculate the required buffer size (in bytes) for directory
- * entries read from the given directory handle. Return -1 if this
- * this cannot be done.
- *
- * If you use autoconf, include fpathconf and dirfd in your
- * AC_CHECK_FUNCS list. Otherwise use some other method to detect
- * and use them where available.
- */
-static dbus_bool_t
-dirent_buf_size(DIR * dirp, size_t *size)
-{
- long name_max;
-# if defined(HAVE_FPATHCONF) && defined(_PC_NAME_MAX)
-# if defined(HAVE_DIRFD)
- name_max = fpathconf(dirfd(dirp), _PC_NAME_MAX);
-# elif defined(HAVE_DDFD)
- name_max = fpathconf(dirp->dd_fd, _PC_NAME_MAX);
-# else
- name_max = fpathconf(dirp->__dd_fd, _PC_NAME_MAX);
-# endif /* HAVE_DIRFD */
- if (name_max == -1)
-# if defined(NAME_MAX)
- name_max = NAME_MAX;
-# else
- return FALSE;
-# endif
-# elif defined(MAXNAMELEN)
- name_max = MAXNAMELEN;
-# else
-# if defined(NAME_MAX)
- name_max = NAME_MAX;
-# else
-# error "buffer size for readdir_r cannot be determined"
-# endif
-# endif
- if (size)
- *size = (size_t)offsetof(struct dirent, d_name) + name_max + 1;
- else
- return FALSE;
-
- return TRUE;
-}
-
/**
* 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.
*
+ * This function is not re-entrant, and not necessarily thread-safe.
+ * Only use it for test code or single-threaded utilities.
+ *
* @param iter the iterator
* @param filename string to be set to the next file in the dir
* @param error return location for error
DBusString *filename,
DBusError *error)
{
- struct dirent *d, *ent;
- size_t buf_size;
+ struct dirent *ent;
int err;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
-
- if (!dirent_buf_size (iter->d, &buf_size))
- {
- dbus_set_error (error, DBUS_ERROR_FAILED,
- "Can't calculate buffer size when reading directory");
- return FALSE;
- }
-
- d = (struct dirent *)dbus_malloc (buf_size);
- if (!d)
- {
- dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
- "No memory to read directory entry");
- return FALSE;
- }
again:
- err = readdir_r (iter->d, d, &ent);
- if (err || !ent)
+ errno = 0;
+ ent = readdir (iter->d);
+
+ if (!ent)
{
+ err = errno;
+
if (err != 0)
dbus_set_error (error,
_dbus_error_from_errno (err),
"%s", _dbus_strerror (err));
- dbus_free (d);
return FALSE;
}
else if (ent->d_name[0] == '.' &&
{
dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
"No memory to read directory entry");
- dbus_free (d);
return FALSE;
}
else
{
- dbus_free (d);
return TRUE;
}
}
{
struct group *g;
int result;
- char buf[1024];
+ size_t buflen;
+ char *buf;
struct group g_str;
+ dbus_bool_t b;
- g = NULL;
-#ifdef HAVE_POSIX_GETPWNAM_R
+ /* retrieve maximum needed size for buf */
+ buflen = sysconf (_SC_GETGR_R_SIZE_MAX);
- 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);
+ /* sysconf actually returns a long, but everything else expects size_t,
+ * so just recast here.
+ * https://bugs.freedesktop.org/show_bug.cgi?id=17061
+ */
+ if ((long) buflen <= 0)
+ buflen = 1024;
+
+ result = -1;
+ while (1)
+ {
+ buf = dbus_malloc (buflen);
+ if (buf == NULL)
+ {
+ dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+ return FALSE;
+ }
+
+ g = NULL;
+#ifdef HAVE_POSIX_GETPWNAM_R
+ if (group_c_str)
+ result = getgrnam_r (group_c_str, &g_str, buf, buflen,
+ &g);
+ else
+ result = getgrgid_r (gid, &g_str, buf, buflen,
+ &g);
#else
- g = getgrnam_r (group_c_str, &g_str, buf, sizeof (buf));
- result = 0;
+ g = getgrnam_r (group_c_str, &g_str, buf, buflen);
+ result = 0;
#endif /* !HAVE_POSIX_GETPWNAM_R */
+ /* Try a bigger buffer if ERANGE was returned:
+ https://bugs.freedesktop.org/show_bug.cgi?id=16727
+ */
+ if (result == ERANGE && buflen < 512 * 1024)
+ {
+ dbus_free (buf);
+ buflen *= 2;
+ }
+ else
+ {
+ break;
+ }
+ }
+
if (result == 0 && g == &g_str)
{
- return fill_user_info_from_group (g, info, error);
+ b = fill_user_info_from_group (g, info, error);
+ dbus_free (buf);
+ return b;
}
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 : "???");
+ dbus_free (buf);
return FALSE;
}
}
dbus_bool_t
_dbus_unix_user_is_process_owner (dbus_uid_t uid)
{
- return uid == _dbus_getuid ();
+ return uid == _dbus_geteuid ();
}
/**
}
/** @} */ /* DBusString stuff */
+static void
+string_squash_nonprintable (DBusString *str)
+{
+ unsigned char *buf;
+ int i, len;
+
+ buf = _dbus_string_get_data (str);
+ len = _dbus_string_get_length (str);
+
+ for (i = 0; i < len; i++)
+ {
+ unsigned char c = (unsigned char) buf[i];
+ if (c == '\0')
+ c = ' ';
+ else if (c < 0x20 || c > 127)
+ c = '?';
+ }
+}
+
+/**
+ * Get a printable string describing the command used to execute
+ * the process with pid. This string should only be used for
+ * informative purposes such as logging; it may not be trusted.
+ *
+ * The command is guaranteed to be printable ASCII and no longer
+ * than max_len.
+ *
+ * @param pid Process id
+ * @param str Append command to this string
+ * @param max_len Maximum length of returned command
+ * @param error return location for errors
+ * @returns #FALSE on error
+ */
+dbus_bool_t
+_dbus_command_for_pid (unsigned long pid,
+ DBusString *str,
+ int max_len,
+ DBusError *error)
+{
+ /* This is all Linux-specific for now */
+ DBusString path;
+ DBusString cmdline;
+ int fd;
+
+ if (!_dbus_string_init (&path))
+ {
+ _DBUS_SET_OOM (error);
+ return FALSE;
+ }
+
+ if (!_dbus_string_init (&cmdline))
+ {
+ _DBUS_SET_OOM (error);
+ _dbus_string_free (&path);
+ return FALSE;
+ }
+
+ if (!_dbus_string_append_printf (&path, "/proc/%ld/cmdline", pid))
+ goto oom;
+
+ fd = open (_dbus_string_get_const_data (&path), O_RDONLY);
+ if (fd < 0)
+ {
+ dbus_set_error (error,
+ _dbus_error_from_errno (errno),
+ "Failed to open \"%s\": %s",
+ _dbus_string_get_const_data (&path),
+ _dbus_strerror (errno));
+ goto fail;
+ }
+
+ if (!_dbus_read (fd, &cmdline, max_len))
+ {
+ dbus_set_error (error,
+ _dbus_error_from_errno (errno),
+ "Failed to read from \"%s\": %s",
+ _dbus_string_get_const_data (&path),
+ _dbus_strerror (errno));
+ goto fail;
+ }
+
+ if (!_dbus_close (fd, error))
+ goto fail;
+
+ string_squash_nonprintable (&cmdline);
+
+ if (!_dbus_string_copy (&cmdline, 0, str, _dbus_string_get_length (str)))
+ goto oom;
+
+ _dbus_string_free (&cmdline);
+ _dbus_string_free (&path);
+ return TRUE;
+oom:
+ _DBUS_SET_OOM (error);
+fail:
+ _dbus_string_free (&cmdline);
+ _dbus_string_free (&path);
+ return FALSE;
+}
projects / platform / upstream / dbus.git / blobdiff