X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fcore%2Fselinux-access.c;h=bc195f3c56e746746bd03d3a5cb2edc0baeb9f34;hp=5edb09a0e95a2fca77e281056c290d65ba105cc3;hb=fea7838e7e0b2724f5e0bc028121a08b42995045;hpb=31c460208d92f90f5d1d9253a9c60a8bb75ff5da
diff --git a/src/core/selinux-access.c b/src/core/selinux-access.c
index 5edb09a0e..bc195f3c5 100644
--- a/src/core/selinux-access.c
+++ b/src/core/selinux-access.c
@@ -19,34 +19,30 @@
along with systemd; If not, see .
***/
-#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
#include
#include
+#include
#include
#include
#ifdef HAVE_AUDIT
#include
#endif
-#include
+#include
-/* 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 "util.h"
+#include "log.h"
+#include "bus-errors.h"
+#include "dbus-common.h"
+#include "audit.h"
+#include "selinux-util.h"
+#include "audit-fd.h"
+
+static bool initialized = false;
struct auditstruct {
const char *path;
@@ -56,106 +52,17 @@ struct auditstruct {
gid_t gid;
};
-/*
- 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
-*/
-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;
+ _cleanup_dbus_message_unref_ DBusMessage *m = NULL, *reply = NULL;
+ DBusMessageIter iter, sub;
+ const char *bytes;
+ char *b;
+ int nbytes;
m = dbus_message_new_method_call(
DBUS_SERVICE_DBUS,
@@ -163,54 +70,43 @@ static int bus_get_selinux_security_context(
DBUS_INTERFACE_DBUS,
"GetConnectionSELinuxSecurityContext");
if (!m) {
- r = -errno;
dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
- goto finish;
+ return -ENOMEM;
}
- r = dbus_message_append_args(
- m,
- DBUS_TYPE_STRING, &name,
- DBUS_TYPE_INVALID);
- if (!r) {
- r = -errno;
+ if (!dbus_message_append_args(
+ m,
+ DBUS_TYPE_STRING, &name,
+ DBUS_TYPE_INVALID)) {
dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
- goto finish;
+ return -ENOMEM;
}
reply = dbus_connection_send_with_reply_and_block(connection, m, -1, error);
- if (!reply) {
- r = -errno;
- goto finish;
- }
+ if (!reply)
+ return -EIO;
- r = dbus_set_error_from_message(error, reply);
- if (!r) {
- r = -errno;
- goto finish;
- }
+ if (dbus_set_error_from_message(error, reply))
+ return -EIO;
- r = dbus_message_get_args(
- reply, error,
- DBUS_TYPE_STRING, scon,
- DBUS_TYPE_INVALID);
- if (!r) {
- r = -errno;
- goto finish;
- }
+ if (!dbus_message_iter_init(reply, &iter))
+ return -EIO;
- r = 0;
-finish:
- if (m)
- dbus_message_unref(m);
+ if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY)
+ return -EIO;
- if (reply)
- dbus_message_unref(reply);
+ dbus_message_iter_recurse(&iter, &sub);
+ dbus_message_iter_get_fixed_array(&sub, &bytes, &nbytes);
- return r;
+ b = strndup(bytes, nbytes);
+ if (!b)
+ return -ENOMEM;
+
+ *scon = b;
+
+ return 0;
}
-/* This mimics dbus_bus_get_unix_user() */
static int bus_get_audit_data(
DBusConnection *connection,
const char *name,
@@ -222,7 +118,7 @@ static int bus_get_audit_data(
pid = bus_get_unix_process_id(connection, name, error);
if (pid <= 0)
- return -EINVAL;
+ return -EIO;
r = audit_loginuid_from_pid(pid, &audit->loginuid);
if (r < 0)
@@ -236,7 +132,7 @@ static int bus_get_audit_data(
if (r < 0)
return r;
- r = get_process_cmdline(pid, LINE_MAX, true, &audit->cmdline);
+ r = get_process_cmdline(pid, 0, true, &audit->cmdline);
if (r < 0)
return r;
@@ -247,14 +143,28 @@ static int bus_get_audit_data(
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)
-{
+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);
+ "auid=%d uid=%d gid=%d%s%s%s%s%s%s",
+ audit->loginuid,
+ audit->uid,
+ audit->gid,
+ (audit->path ? " path=\"" : ""),
+ strempty(audit->path),
+ (audit->path ? "\"" : ""),
+ (audit->cmdline ? " cmdline=\"" : ""),
+ strempty(audit->cmdline),
+ (audit->cmdline ? "\"" : ""));
+
+ msgbuf[msgbufsize-1] = 0;
+
return 0;
}
@@ -264,24 +174,30 @@ static int audit_callback(void *auditdata, security_class_t cls,
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, ...)
-{
+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);
+ 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;
+ }
+
+ va_start(ap, fmt);
}
#endif
log_metav(LOG_USER | LOG_INFO, __FILE__, __LINE__, __FUNCTION__, fmt, ap);
va_end(ap);
+
return 0;
}
@@ -291,93 +207,87 @@ static int log_callback(int type, const char *fmt, ...)
If you want to cleanup memory you should need to call selinux_access_finish.
*/
static int access_init(void) {
-
- int r = -1;
+ int r;
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);
+ if (security_getenforce() >= 0)
return 0;
- }
+
r = -errno;
avc_destroy();
+
return r;
}
-static int selinux_init(Manager *m, DBusError *error) {
-
+static int selinux_access_init(DBusError *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 */
+ if (use_selinux()) {
r = access_init();
if (r < 0) {
- dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Unable to initialize SELinux.");
-
+ dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to initialize SELinux.");
return r;
}
- first_time = 0;
}
+ initialized = true;
return 0;
}
+void selinux_access_free(void) {
+ if (!initialized)
+ return;
+
+ avc_destroy();
+ initialized = false;
+}
+
static int get_audit_data(
- DBusConnection *connection,
- DBusMessage *message,
- struct auditstruct *audit,
- DBusError *error) {
+ DBusConnection *connection,
+ DBusMessage *message,
+ struct auditstruct *audit,
+ DBusError *error) {
const char *sender;
- int r;
+ int r, fd;
+ struct ucred ucred;
+ socklen_t len = sizeof(ucred);
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;
+ 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;
- }
+ 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;
+ audit->uid = ucred.uid;
+ audit->gid = ucred.gid;
- r = audit_loginuid_from_pid(ucred.pid, &audit->loginuid);
- if (r < 0)
- return r;
+ 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;
+ r = get_process_cmdline(ucred.pid, 0, true, &audit->cmdline);
+ if (r < 0)
+ return r;
- return 0;
- }
+ return 0;
}
/*
@@ -385,13 +295,14 @@ static int get_audit_data(
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) {
+ DBusConnection *connection,
+ DBusMessage *message,
+ security_context_t *scon,
+ DBusError *error) {
const char *sender;
int r;
+ int fd;
/*
If sender exists then
@@ -401,45 +312,25 @@ static int get_calling_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;
- }
+ if (r >= 0)
+ return r;
- return 0;
-}
+ log_error("bus_get_selinux_security_context failed: %m");
+ return r;
+ }
-/*
- 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;
- }
+ if (!dbus_connection_get_unix_fd(connection, &fd)) {
+ log_error("bus_connection_get_unix_fd failed %m");
+ return -EINVAL;
+ }
- NULSTR_FOREACH_PAIR(m, p, system_methods)
- if (streq(method, m)) {
- *perm = p;
- *require_unit = false;
- return;
- }
+ r = getpeercon(fd, scon);
+ if (r < 0) {
+ log_error("getpeercon failed %m");
+ return -errno;
+ }
- *require_unit = false;
- *perm = "undefined";
+ return 0;
}
/*
@@ -448,28 +339,49 @@ static void selinux_perm_lookup(const char *method, const char **perm, bool *req
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;
- security_context_t fcon = NULL;
+int selinux_access_check(
+ DBusConnection *connection,
+ DBusMessage *message,
+ const char *path,
+ const char *permission,
+ DBusError *error) {
+
+ security_context_t scon = NULL, fcon = NULL;
int r = 0;
const char *tclass = NULL;
struct auditstruct audit;
+ assert(connection);
+ assert(message);
+ assert(permission);
+ assert(error);
+
+ if (!use_selinux())
+ return 0;
+
+ r = selinux_access_init(error);
+ if (r < 0)
+ return r;
+
audit.uid = audit.loginuid = (uid_t) -1;
audit.gid = (gid_t) -1;
audit.cmdline = NULL;
audit.path = path;
r = get_calling_context(connection, message, &scon, error);
- if (r != 0)
+ if (r < 0) {
+ log_error("Failed to get caller's security context on: %m");
goto finish;
+ }
if (path) {
tclass = "service";
/* 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);
+ dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to get file context on %s.", path);
+ r = -errno;
+ log_error("Failed to get security context on %s: %m",path);
goto finish;
}
@@ -477,63 +389,31 @@ static int selinux_access_check(DBusConnection *connection, DBusMessage *message
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.");
+ dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to get current context.");
+ r = -errno;
+ log_error("Failed to get current process context on: %m");
goto finish;
}
}
(void) get_audit_data(connection, message, &audit, error);
- errno= 0;
- r = selinux_check_access(scon, fcon, tclass, perm, &audit);
+ errno = 0;
+ r = selinux_check_access(scon, fcon, tclass, permission, &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.");
+ r = -errno;
+ log_error("SELinux policy denies access.");
}
- 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;
+ log_debug("SELinux access check scon=%s tcon=%s tclass=%s perm=%s path=%s cmdline=%s: %i", scon, fcon, tclass, permission, path, audit.cmdline, r);
+finish:
free(audit.cmdline);
freecon(scon);
freecon(fcon);
- return r;
-}
-
-/*
- Clean up memory allocated in selinux_avc_init
-*/
-void selinux_access_finish(void) {
- if (!first_time)
- avc_destroy();
- first_time = 1;
-}
-
-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);
- 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-unit Look %s up perm %s require_unit %d", member, perm, require_unit);
-
- r = selinux_access_check(connection, message, m, error, perm, path);
- if (r < 0 && !selinux_enforcing) {
+ if (r && security_getenforce() != 1) {
dbus_error_init(error);
r = 0;
}
@@ -541,66 +421,19 @@ int selinux_unit_access_check(DBusConnection *connection, DBusMessage *message,
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;
- }
-
- path = u->source_path ? u->source_path : u->fragment_path;
- }
- r = selinux_access_check(connection, message, m, error, perm, path);
+#else
-finish:
- /* if SELinux is in permissive mode return 0 */
- if (r && (!selinux_enforcing)) {
- dbus_error_init(error);
- r = 0;
- }
- return r;
-}
+int selinux_access_check(
+ DBusConnection *connection,
+ DBusMessage *message,
+ const char *path,
+ const char *permission,
+ DBusError *error) {
-#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