Copyright 2012 Dan Walsh
systemd 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
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
-#include "util.h"
-#include "job.h"
-#include "manager.h"
#include "selinux-access.h"
#ifdef HAVE_SELINUX
-#include "dbus.h"
-#include "log.h"
-#include "dbus-unit.h"
-#include "bus-errors.h"
-#include "dbus-common.h"
-#include "audit.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>
+#include <limits.h>
#include <selinux/selinux.h>
#include <selinux/avc.h>
+#include <sys/socket.h>
#ifdef HAVE_AUDIT
#include <libaudit.h>
#endif
-#include <limits.h>
-/* FD to send audit messages to */
-static int audit_fd = -1;
-static int selinux_enabled = -1;
-static int first_time = 1;
-static int selinux_enforcing = 0;
+#include "sd-bus.h"
+#include "bus-util.h"
+#include "util.h"
+#include "log.h"
+#include "audit.h"
+#include "selinux-util.h"
+#include "audit-fd.h"
+#include "strv.h"
+
+static bool initialized = false;
-struct auditstruct {
+struct audit_info {
+ sd_bus_creds *creds;
const char *path;
- char *cmdline;
- uid_t loginuid;
- uid_t uid;
- gid_t gid;
+ const char *cmdline;
};
/*
- Define a mapping between the systemd method calls and the SELinux access to check.
- We define two tables, one for access checks on unit files, and one for
- access checks for the system in general.
-
- If we do not find a match in either table, then the "undefined" system
- check will be called.
-*/
-
-static const char unit_methods[] =
- "DisableUnitFiles\0" "disable\0"
- "EnableUnitFiles\0" "enable\0"
- "GetUnit\0" "status\0"
- "GetUnitFileState\0" "status\0"
- "Kill\0" "stop\0"
- "KillUnit\0" "stop\0"
- "LinkUnitFiles\0" "enable\0"
- "MaskUnitFiles\0" "disable\0"
- "PresetUnitFiles\0" "enable\0"
- "ReenableUnitFiles\0" "enable\0"
- "ReloadOrRestart\0" "start\0"
- "ReloadOrRestartUnit\0" "start\0"
- "ReloadOrTryRestart\0" "start\0"
- "ReloadOrTryRestartUnit\0" "start\0"
- "Reload\0" "reload\0"
- "ReloadUnit\0" "reload\0"
- "ResetFailedUnit\0" "stop\0"
- "Restart\0" "start\0"
- "RestartUnit\0" "start\0"
- "Start\0" "start\0"
- "StartUnit\0" "start\0"
- "StartUnitReplace\0" "start\0"
- "Stop\0" "stop\0"
- "StopUnit\0" "stop\0"
- "TryRestart\0" "start\0"
- "TryRestartUnit\0" "start\0"
- "UnmaskUnitFiles\0" "enable\0";
-
-static const char system_methods[] =
- "ClearJobs\0" "reboot\0"
- "CreateSnapshot\0" "status\0"
- "Dump\0" "status\0"
- "Exit\0" "halt\0"
- "FlushDevices\0" "halt\0"
- "Get\0" "status\0"
- "GetAll\0" "status\0"
- "GetJob\0" "status\0"
- "GetSeat\0" "status\0"
- "GetSession\0" "status\0"
- "GetSessionByPID\0" "status\0"
- "GetUnitByPID\0" "status\0"
- "GetUser\0" "status\0"
- "Halt\0" "halt\0"
- "Introspect\0" "status\0"
- "KExec\0" "reboot\0"
- "KillSession\0" "halt\0"
- "KillUser\0" "halt\0"
- "LoadUnit\0" "reload\0"
- "ListJobs\0" "status\0"
- "ListSeats\0" "status\0"
- "ListSessions\0" "status\0"
- "ListUnits\0" "status\0"
- "ListUnitFiles\0" "status\0"
- "ListUsers\0" "status\0"
- "LockSession\0" "halt\0"
- "PowerOff\0" "halt\0"
- "Reboot\0" "reboot\0"
- "Reload\0" "reload\0"
- "Reexecute\0" "reload\0"
- "ResetFailed\0" "reload\0"
- "Subscribe\0" "status\0"
- "SwithcRoot\0" "reboot\0"
- "SetEnvironment\0" "status\0"
- "SetUserLinger\0" "halt\0"
- "TerminateSeat\0" "halt\0"
- "TerminateSession\0" "halt\0"
- "TerminateUser\0" "halt\0"
- "Unsubscribe\0" "status\0"
- "UnsetEnvironment\0" "status\0"
- "UnsetAndSetEnvironment\0" "status\0";
-
-/*
- If the admin toggles the selinux enforcment mode this callback
- will get called before the next access check
+ Any time an access gets denied this callback will be called
+ with the aduit data. We then need to just copy the audit data into the msgbuf.
*/
-static int setenforce_callback(int enforcing)
-{
- selinux_enforcing = enforcing;
- return 0;
-}
-
-/* This mimics dbus_bus_get_unix_user() */
-static int bus_get_selinux_security_context(
- DBusConnection *connection,
- const char *name,
- char **scon,
- DBusError *error) {
-
- DBusMessage *m = NULL, *reply = NULL;
- int r;
-
- m = dbus_message_new_method_call(
- DBUS_SERVICE_DBUS,
- DBUS_PATH_DBUS,
- DBUS_INTERFACE_DBUS,
- "GetConnectionSELinuxSecurityContext");
- if (!m) {
- r = -errno;
- dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
- goto finish;
- }
-
- r = dbus_message_append_args(
- m,
- DBUS_TYPE_STRING, &name,
- DBUS_TYPE_INVALID);
- if (!r) {
- r = -errno;
- dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
- goto finish;
- }
-
- reply = dbus_connection_send_with_reply_and_block(connection, m, -1, error);
- if (!reply) {
- r = -errno;
- goto finish;
- }
-
- r = dbus_set_error_from_message(error, reply);
- if (!r) {
- r = -errno;
- goto finish;
- }
-
- r = dbus_message_get_args(
- reply, error,
- DBUS_TYPE_STRING, scon,
- DBUS_TYPE_INVALID);
- if (!r) {
- r = -errno;
- goto finish;
- }
-
- r = 0;
-finish:
- if (m)
- dbus_message_unref(m);
-
- if (reply)
- dbus_message_unref(reply);
-
- return r;
-}
-
-/* This mimics dbus_bus_get_unix_user() */
-static int bus_get_audit_data(
- DBusConnection *connection,
- const char *name,
- struct auditstruct *audit,
- DBusError *error) {
-
- pid_t pid;
- int r;
-
- pid = bus_get_unix_process_id(connection, name, error);
- if (pid <= 0)
- return -EINVAL;
-
- r = audit_loginuid_from_pid(pid, &audit->loginuid);
- if (r < 0)
- return r;
+static int audit_callback(
+ void *auditdata,
+ security_class_t cls,
+ char *msgbuf,
+ size_t msgbufsize) {
- r = get_process_uid(pid, &audit->uid);
- if (r < 0)
- return r;
+ const struct audit_info *audit = auditdata;
+ uid_t uid = 0, login_uid = 0;
+ gid_t gid = 0;
- r = get_process_gid(pid, &audit->gid);
- if (r < 0)
- return r;
+ sd_bus_creds_get_audit_login_uid(audit->creds, &login_uid);
+ sd_bus_creds_get_uid(audit->creds, &uid);
+ sd_bus_creds_get_gid(audit->creds, &gid);
- r = get_process_cmdline(pid, LINE_MAX, true, &audit->cmdline);
- if (r < 0)
- return r;
+ snprintf(msgbuf, msgbufsize,
+ "auid=%d uid=%d gid=%d%s%s%s%s%s%s",
+ login_uid, uid, gid,
+ audit->path ? " path=\"" : "", strempty(audit->path), audit->path ? "\"" : "",
+ audit->cmdline ? " cmdline=\"" : "", strempty(audit->cmdline), audit->cmdline ? "\"" : "");
- return 0;
-}
+ msgbuf[msgbufsize-1] = 0;
-/*
- Any time an access gets denied this callback will be called
- with the aduit data. We then need to just copy the audit data into the msgbuf.
-*/
-static int audit_callback(void *auditdata, security_class_t cls,
- char *msgbuf, size_t msgbufsize)
-{
- struct auditstruct *audit = (struct auditstruct *) auditdata;
- snprintf(msgbuf, msgbufsize,
- "name=\"%s\" cmdline=\"%s\" auid=%d uid=%d gid=%d",
- audit->path, audit->cmdline, audit->loginuid,
- audit->uid, audit->gid);
return 0;
}
user_avc's into the /var/log/audit/audit.log, otherwise they will be
sent to syslog.
*/
-static int log_callback(int type, const char *fmt, ...)
-{
+_printf_(2, 3) static int log_callback(int type, const char *fmt, ...) {
va_list ap;
- va_start(ap, fmt);
#ifdef HAVE_AUDIT
- if (audit_fd >= 0) {
- char buf[LINE_MAX*2];
+ if (get_audit_fd() >= 0) {
+ _cleanup_free_ char *buf = NULL;
+ int r;
- vsnprintf(buf, sizeof(buf), fmt, ap);
- audit_log_user_avc_message(audit_fd, AUDIT_USER_AVC,
- buf, NULL, NULL, NULL, 0);
+ va_start(ap, fmt);
+ r = vasprintf(&buf, fmt, ap);
va_end(ap);
- return 0;
+
+ if (r >= 0) {
+ audit_log_user_avc_message(get_audit_fd(), AUDIT_USER_AVC, buf, NULL, NULL, NULL, 0);
+ return 0;
+ }
}
#endif
+
+ va_start(ap, fmt);
log_metav(LOG_USER | LOG_INFO, __FILE__, __LINE__, __FUNCTION__, fmt, ap);
va_end(ap);
+
return 0;
}
If you want to cleanup memory you should need to call selinux_access_finish.
*/
static int access_init(void) {
-
- int r = -1;
+ int r = 0;
if (avc_open(NULL, 0)) {
- log_full(LOG_ERR, "avc_open failed: %m\n");
+ log_error("avc_open() failed: %m");
return -errno;
}
- selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) &audit_callback);
- selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) &log_callback);
- selinux_set_callback(SELINUX_CB_SETENFORCE, (union selinux_callback) &setenforce_callback);
+ selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) audit_callback);
+ selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) log_callback);
- if ((r = security_getenforce()) >= 0) {
- setenforce_callback(r);
- return 0;
+ if (security_getenforce() < 0){
+ r = -errno;
+ avc_destroy();
}
- r = -errno;
- avc_destroy();
+
return r;
}
-static int selinux_init(Manager *m, DBusError *error) {
-
+static int selinux_access_init(sd_bus_error *error) {
int r;
-#ifdef HAVE_AUDIT
- audit_fd = m->audit_fd;
-#endif
- if (!first_time)
+ if (initialized)
return 0;
- if (selinux_enabled < 0)
- selinux_enabled = is_selinux_enabled() == 1;
-
- if (selinux_enabled) {
- /* if not first time is not set, then initialize access */
- r = access_init();
- if (r < 0) {
- dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Unable to initialize SELinux.");
-
- return r;
- }
- first_time = 0;
- }
-
- return 0;
-}
-
-static int get_audit_data(
- DBusConnection *connection,
- DBusMessage *message,
- struct auditstruct *audit,
- DBusError *error) {
-
- const char *sender;
- int r;
-
- sender = dbus_message_get_sender(message);
- if (sender)
- return bus_get_audit_data(connection, sender, audit, error);
- else {
- int fd;
- struct ucred ucred;
- socklen_t len;
-
- if (!dbus_connection_get_unix_fd(connection, &fd))
- return -EINVAL;
-
- r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len);
- if (r < 0) {
- log_error("Failed to determine peer credentials: %m");
- return -errno;
- }
-
- audit->uid = ucred.uid;
- audit->gid = ucred.gid;
-
- r = audit_loginuid_from_pid(ucred.pid, &audit->loginuid);
- if (r < 0)
- return r;
-
- r = get_process_cmdline(ucred.pid, LINE_MAX, true, &audit->cmdline);
- if (r < 0)
- return r;
-
+ if (!use_selinux())
return 0;
- }
-}
-
-/*
- This function returns the security context of the remote end of the dbus
- connections. Whether it is on the bus or a local connection.
-*/
-static int get_calling_context(
- DBusConnection *connection,
- DBusMessage *message,
- security_context_t *scon,
- DBusError *error) {
- const char *sender;
- int r;
-
- /*
- If sender exists then
- if sender is NULL this indicates a local connection. Grab the fd
- from dbus and do an getpeercon to peers process context
- */
- sender = dbus_message_get_sender(message);
- if (sender) {
- r = bus_get_selinux_security_context(connection, sender, scon, error);
- if (r < 0)
- return -EINVAL;
- } else {
- int fd;
- r = dbus_connection_get_unix_fd(connection, &fd);
- if (! r)
- return -EINVAL;
-
- r = getpeercon(fd, scon);
- if (r < 0)
- return -errno;
- }
+ r = access_init();
+ if (r < 0)
+ return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to initialize SELinux.");
+ initialized = true;
return 0;
}
-/*
- This function returns the SELinux permission to check and whether or not the
- check requires a unit file.
-*/
-static void selinux_perm_lookup(const char *method, const char **perm, bool *require_unit) {
- const char *m, *p;
-
- NULSTR_FOREACH_PAIR(m, p, unit_methods)
- if (streq(method, m)) {
- *perm = p;
- *require_unit = true;
- return;
- }
+void selinux_access_free(void) {
- NULSTR_FOREACH_PAIR(m, p, system_methods)
- if (streq(method, m)) {
- *perm = p;
- *require_unit = false;
- return;
- }
+ if (!initialized)
+ return;
- *require_unit = false;
- *perm = "undefined";
+ avc_destroy();
+ initialized = false;
}
/*
If the machine is in permissive mode it will return ok. Audit messages will
still be generated if the access would be denied in enforcing mode.
*/
-static int selinux_access_check(DBusConnection *connection, DBusMessage *message, Manager *m, DBusError *error, const char *perm, const char *path) {
- security_context_t scon = NULL;
+int selinux_generic_access_check(
+ sd_bus_message *message,
+ const char *path,
+ const char *permission,
+ sd_bus_error *error) {
+
+ _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+ const char *tclass = NULL, *scon = NULL;
+ struct audit_info audit_info = {};
+ _cleanup_free_ char *cl = NULL;
security_context_t fcon = NULL;
+ char **cmdline = NULL;
int r = 0;
- const char *tclass = NULL;
- struct auditstruct audit;
- audit.uid = audit.loginuid = (uid_t) -1;
- audit.gid = (gid_t) -1;
- audit.cmdline = NULL;
- audit.path = path;
+ assert(message);
+ assert(permission);
+ assert(error);
+
+ if (!use_selinux())
+ return 0;
+
+ r = selinux_access_init(error);
+ if (r < 0)
+ return r;
- r = get_calling_context(connection, message, &scon, error);
- if (r != 0)
+ r = sd_bus_query_sender_creds(
+ message,
+ SD_BUS_CREDS_PID|SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|
+ SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_AUDIT_LOGIN_UID|
+ SD_BUS_CREDS_SELINUX_CONTEXT,
+ &creds);
+ if (r < 0)
+ goto finish;
+
+ r = sd_bus_creds_get_selinux_context(creds, &scon);
+ if (r < 0)
goto finish;
if (path) {
- tclass = "service";
- /* get the file context of the unit file */
+ /* Get the file context of the unit file */
+
r = getfilecon(path, &fcon);
if (r < 0) {
- log_full(LOG_ERR, "Failed to get security context on: %s %m\n",path);
+ r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get file context on %s.", path);
goto finish;
}
+ tclass = "service";
} else {
- tclass = "system";
r = getcon(&fcon);
if (r < 0) {
- dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Unable to get current context, SELinux policy denies access.");
+ r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get current context.");
goto finish;
}
- }
-
- (void) get_audit_data(connection, message, &audit, error);
-
- errno= 0;
- r = selinux_check_access(scon, fcon, tclass, perm, &audit);
- if (r < 0) {
- r = -errno;
- log_error("SELinux Denied \"%s\"", audit.cmdline);
- dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "SELinux policy denies access.");
+ tclass = "system";
}
- log_debug("SELinux checkaccess scon %s tcon %s tclass %s perm %s path %s: %d", scon, fcon, tclass, perm, path, r);
-finish:
- if (r)
- r = -errno;
-
- free(audit.cmdline);
- freecon(scon);
- freecon(fcon);
-
- return r;
-}
+ sd_bus_creds_get_cmdline(creds, &cmdline);
+ cl = strv_join(cmdline, " ");
-/*
- Clean up memory allocated in selinux_avc_init
-*/
-void selinux_access_finish(void) {
- if (!first_time)
- avc_destroy();
- first_time = 1;
-}
+ audit_info.creds = creds;
+ audit_info.path = path;
+ audit_info.cmdline = cl;
-int selinux_unit_access_check(DBusConnection *connection, DBusMessage *message, Manager *m, const char *path, DBusError *error) {
- const char *perm;
- bool require_unit;
- const char *member;
- int r;
-
- r = selinux_init(m, error);
+ r = selinux_check_access((security_context_t) scon, fcon, tclass, permission, &audit_info);
if (r < 0)
- return r;
+ r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "SELinux policy denies access.");
- if (! selinux_enabled)
- return 0;
-
- member = dbus_message_get_member(message);
+ log_debug("SELinux access check scon=%s tcon=%s tclass=%s perm=%s path=%s cmdline=%s: %i", scon, fcon, tclass, permission, path, cl, r);
- selinux_perm_lookup(member, &perm, &require_unit);
- log_debug("SELinux dbus-unit Look %s up perm %s require_unit %d", member, perm, require_unit);
+finish:
+ freecon(fcon);
- r = selinux_access_check(connection, message, m, error, perm, path);
- if (r < 0 && !selinux_enforcing) {
- dbus_error_init(error);
+ if (r < 0 && security_getenforce() != 1) {
+ sd_bus_error_free(error);
r = 0;
}
return r;
}
-int selinux_manager_access_check(DBusConnection *connection, DBusMessage *message, Manager *m, DBusError *error) {
- int r = -1;
- const char *member;
- bool require_unit;
- const char *perm;
- char *path = NULL;
-
- r = selinux_init(m, error);
- if (r < 0)
- return r;
-
- if (! selinux_enabled)
- return 0;
-
- member = dbus_message_get_member(message);
-
- selinux_perm_lookup(member, &perm, &require_unit);
- log_debug("SELinux dbus-manager Lookup %s perm %s require_unit %d", member, perm, require_unit);
-
- if (require_unit) {
- const char *name;
- Unit *u;
-
- if (!dbus_message_get_args(
- message,
- error,
- DBUS_TYPE_STRING, &name,
- DBUS_TYPE_INVALID)) {
- r = -EINVAL;
- goto finish;
- }
-
- r = manager_load_unit(m, name, NULL, error, &u);
- if (r < 0) {
- dbus_set_error(error, BUS_ERROR_NO_SUCH_UNIT, "Unit %s is not loaded.", name);
- goto finish;
- }
+#else
- path = u->source_path ? u->source_path : u->fragment_path;
- }
- r = selinux_access_check(connection, message, m, error, perm, path);
+int selinux_generic_access_check(
+ sd_bus_message *message,
+ const char *path,
+ const char *permission,
+ sd_bus_error *error) {
-finish:
- /* if SELinux is in permissive mode return 0 */
- if (r && (!selinux_enforcing)) {
- dbus_error_init(error);
- r = 0;
- }
- return r;
-}
-
-#else
-int selinux_unit_access_check(DBusConnection *connection, DBusMessage *message, Manager *m, const char *path, DBusError *error) {
return 0;
}
-int selinux_manager_access_check(DBusConnection *connection, DBusMessage *message, Manager *m, DBusError *error) {
- return 0;
+void selinux_access_free(void) {
}
-void selinux_access_finish(void) {
-}
#endif
~ianmdlvl / elogind.git / blobdiff