Add SPDX license identifiers to source files under the LGPL

[thirdparty/systemd.git] / src / core / selinux-access.c

diff --git a/src/core/selinux-access.c b/src/core/selinux-access.c
index 8856927c88f62664bc4f34eb3ccda60a4dd8a3f5..475c3181c9f02911dc0dbf83321b9aedcae60862 100644 (file)
--- a/src/core/selinux-access.c
+++ b/src/core/selinux-access.c
@@ -1,5 +1,4 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
+/* SPDX-License-Identifier: LGPL-2.1+ */
 /***
   This file is part of systemd.
 
@@ -21,13 +20,13 @@
 
 #include "selinux-access.h"
 
-#ifdef HAVE_SELINUX
+#if HAVE_SELINUX
 
 #include <errno.h>
 #include <selinux/avc.h>
 #include <selinux/selinux.h>
 #include <stdio.h>
-#ifdef HAVE_AUDIT
+#if HAVE_AUDIT
 #include <libaudit.h>
 #endif
 
@@ -112,8 +111,9 @@ static int callback_type_to_priority(int type) {
 */
 _printf_(2, 3) static int log_callback(int type, const char *fmt, ...) {
         va_list ap;
+        const char *fmt2;
 
-#ifdef HAVE_AUDIT
+#if HAVE_AUDIT
         int fd;
 
         fd = get_audit_fd();
@@ -133,53 +133,53 @@ _printf_(2, 3) static int log_callback(int type, const char *fmt, ...) {
         }
 #endif
 
+        fmt2 = strjoina("selinux: ", fmt);
+
         va_start(ap, fmt);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
         log_internalv(LOG_AUTH | callback_type_to_priority(type),
-                      0, __FILE__, __LINE__, __FUNCTION__, fmt, ap);
+                      0, __FILE__, __LINE__, __FUNCTION__,
+                      fmt2, ap);
+#pragma GCC diagnostic pop
         va_end(ap);
 
         return 0;
 }
 
-/*
-   Function must be called once to initialize the SELinux AVC environment.
-   Sets up callbacks.
-   If you want to cleanup memory you should need to call selinux_access_finish.
-*/
-static int access_init(void) {
-        int r = 0;
-
-        if (avc_open(NULL, 0))
-                return log_error_errno(errno, "avc_open() failed: %m");
+static int access_init(sd_bus_error *error) {
 
-        selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) audit_callback);
-        selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) log_callback);
+        if (!mac_selinux_use())
+                return 0;
 
-        if (security_getenforce() < 0){
-                r = -errno;
-                avc_destroy();
-        }
+        if (initialized)
+                return 1;
 
-        return r;
-}
+        if (avc_open(NULL, 0) != 0) {
+                int enforce, saved_errno = errno;
 
-static int mac_selinux_access_init(sd_bus_error *error) {
-        int r;
+                enforce = security_getenforce();
+                log_full_errno(enforce != 0 ? LOG_ERR : LOG_WARNING, saved_errno, "Failed to open the SELinux AVC: %m");
 
-        if (initialized)
-                return 0;
+                /* If enforcement isn't on, then let's suppress this
+                 * error, and just don't do any AVC checks. The
+                 * warning we printed is hence all the admin will
+                 * see. */
+                if (enforce == 0)
+                        return 0;
 
-        if (!mac_selinux_use())
-                return 0;
+                /* Return an access denied error, if we couldn't load
+                 * the AVC but enforcing mode was on, or we couldn't
+                 * determine whether it is one. */
+                return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to open the SELinux AVC: %s", strerror(saved_errno));
+        }
 
-        r = access_init();
-        if (r < 0)
-                return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to initialize SELinux.");
+        selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) audit_callback);
+        selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) log_callback);
 
         initialized = true;
-        return 0;
+        return 1;
 }
-#endif
 
 /*
    This function communicates with the kernel to check whether or not it should
@@ -193,12 +193,11 @@ int mac_selinux_generic_access_check(
                 const char *permission,
                 sd_bus_error *error) {
 
-#ifdef HAVE_SELINUX
-        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        _cleanup_(sd_bus_creds_unrefp) 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 *fcon = NULL;
         char **cmdline = NULL;
         int r = 0;
 
@@ -206,11 +205,8 @@ int mac_selinux_generic_access_check(
         assert(permission);
         assert(error);
 
-        if (!mac_selinux_use())
-                return 0;
-
-        r = mac_selinux_access_init(error);
-        if (r < 0)
+        r = access_init(error);
+        if (r <= 0)
                 return r;
 
         r = sd_bus_query_sender_creds(
@@ -277,7 +273,17 @@ finish:
         }
 
         return r;
+}
+
 #else
+
+int mac_selinux_generic_access_check(
+                sd_bus_message *message,
+                const char *path,
+                const char *permission,
+                sd_bus_error *error) {
+
         return 0;
-#endif
 }
+
+#endif