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-rw-r--r--src/shared/label.c413
1 files changed, 413 insertions, 0 deletions
diff --git a/src/shared/label.c b/src/shared/label.c
new file mode 100644
index 000000000..2c887a0fe
--- /dev/null
+++ b/src/shared/label.c
@@ -0,0 +1,413 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ 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
+ (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.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <malloc.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include "label.h"
+#include "util.h"
+
+#ifdef HAVE_SELINUX
+#include <selinux/selinux.h>
+#include <selinux/label.h>
+
+static struct selabel_handle *label_hnd = NULL;
+
+static int use_selinux_cached = -1;
+
+static inline bool use_selinux(void) {
+
+ if (use_selinux_cached < 0)
+ use_selinux_cached = is_selinux_enabled() > 0;
+
+ return use_selinux_cached;
+}
+
+void label_retest_selinux(void) {
+ use_selinux_cached = -1;
+}
+
+#endif
+
+int label_init(void) {
+ int r = 0;
+
+#ifdef HAVE_SELINUX
+ usec_t before_timestamp, after_timestamp;
+ struct mallinfo before_mallinfo, after_mallinfo;
+
+ if (!use_selinux())
+ return 0;
+
+ if (label_hnd)
+ return 0;
+
+ before_mallinfo = mallinfo();
+ before_timestamp = now(CLOCK_MONOTONIC);
+
+ label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0);
+ if (!label_hnd) {
+ log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
+ "Failed to initialize SELinux context: %m");
+ r = security_getenforce() == 1 ? -errno : 0;
+ } else {
+ char timespan[FORMAT_TIMESPAN_MAX];
+ int l;
+
+ after_timestamp = now(CLOCK_MONOTONIC);
+ after_mallinfo = mallinfo();
+
+ l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0;
+
+ log_info("Successfully loaded SELinux database in %s, size on heap is %iK.",
+ format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp),
+ (l+1023)/1024);
+ }
+#endif
+
+ return r;
+}
+
+int label_fix(const char *path, bool ignore_enoent) {
+ int r = 0;
+
+#ifdef HAVE_SELINUX
+ struct stat st;
+ security_context_t fcon;
+
+ if (!use_selinux() || !label_hnd)
+ return 0;
+
+ r = lstat(path, &st);
+ if (r == 0) {
+ r = selabel_lookup_raw(label_hnd, &fcon, path, st.st_mode);
+
+ /* If there's no label to set, then exit without warning */
+ if (r < 0 && errno == ENOENT)
+ return 0;
+
+ if (r == 0) {
+ r = lsetfilecon(path, fcon);
+ freecon(fcon);
+
+ /* If the FS doesn't support labels, then exit without warning */
+ if (r < 0 && errno == ENOTSUP)
+ return 0;
+ }
+ }
+
+ if (r < 0) {
+ /* Ignore ENOENT in some cases */
+ if (ignore_enoent && errno == ENOENT)
+ return 0;
+
+ log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
+ "Unable to fix label of %s: %m", path);
+ r = security_getenforce() == 1 ? -errno : 0;
+ }
+#endif
+
+ return r;
+}
+
+void label_finish(void) {
+
+#ifdef HAVE_SELINUX
+ if (use_selinux() && label_hnd)
+ selabel_close(label_hnd);
+#endif
+}
+
+int label_get_create_label_from_exe(const char *exe, char **label) {
+
+ int r = 0;
+
+#ifdef HAVE_SELINUX
+ security_context_t mycon = NULL, fcon = NULL;
+ security_class_t sclass;
+
+ if (!use_selinux()) {
+ *label = NULL;
+ return 0;
+ }
+
+ r = getcon(&mycon);
+ if (r < 0)
+ goto fail;
+
+ r = getfilecon(exe, &fcon);
+ if (r < 0)
+ goto fail;
+
+ sclass = string_to_security_class("process");
+ r = security_compute_create(mycon, fcon, sclass, (security_context_t *) label);
+ if (r == 0)
+ log_debug("SELinux Socket context for %s will be set to %s", exe, *label);
+
+fail:
+ if (r < 0 && security_getenforce() == 1)
+ r = -errno;
+
+ freecon(mycon);
+ freecon(fcon);
+#endif
+
+ return r;
+}
+
+int label_fifofile_set(const char *path) {
+ int r = 0;
+
+#ifdef HAVE_SELINUX
+ security_context_t filecon = NULL;
+
+ if (!use_selinux() || !label_hnd)
+ return 0;
+
+ r = selabel_lookup_raw(label_hnd, &filecon, path, S_IFIFO);
+ if (r < 0)
+ r = -errno;
+ else if (r == 0) {
+ r = setfscreatecon(filecon);
+ if (r < 0) {
+ log_error("Failed to set SELinux file context on %s: %m", path);
+ r = -errno;
+ }
+
+ freecon(filecon);
+ }
+
+ if (r < 0 && security_getenforce() == 0)
+ r = 0;
+#endif
+
+ return r;
+}
+
+int label_symlinkfile_set(const char *path) {
+ int r = 0;
+
+#ifdef HAVE_SELINUX
+ security_context_t filecon = NULL;
+
+ if (!use_selinux() || !label_hnd)
+ return 0;
+
+ r = selabel_lookup_raw(label_hnd, &filecon, path, S_IFLNK);
+ if (r < 0)
+ r = -errno;
+ else if (r == 0) {
+ r = setfscreatecon(filecon);
+ if (r < 0) {
+ log_error("Failed to set SELinux file context on %s: %m", path);
+ r = -errno;
+ }
+
+ freecon(filecon);
+ }
+
+ if (r < 0 && security_getenforce() == 0)
+ r = 0;
+#endif
+
+ return r;
+}
+
+int label_socket_set(const char *label) {
+
+#ifdef HAVE_SELINUX
+ if (!use_selinux())
+ return 0;
+
+ if (setsockcreatecon((security_context_t) label) < 0) {
+ log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG,
+ "Failed to set SELinux context (%s) on socket: %m", label);
+
+ if (security_getenforce() == 1)
+ return -errno;
+ }
+#endif
+
+ return 0;
+}
+
+void label_file_clear(void) {
+
+#ifdef HAVE_SELINUX
+ if (!use_selinux())
+ return;
+
+ setfscreatecon(NULL);
+#endif
+}
+
+void label_socket_clear(void) {
+
+#ifdef HAVE_SELINUX
+ if (!use_selinux())
+ return;
+
+ setsockcreatecon(NULL);
+#endif
+}
+
+void label_free(const char *label) {
+
+#ifdef HAVE_SELINUX
+ if (!use_selinux())
+ return;
+
+ freecon((security_context_t) label);
+#endif
+}
+
+int label_mkdir(const char *path, mode_t mode) {
+
+ /* Creates a directory and labels it according to the SELinux policy */
+
+#ifdef HAVE_SELINUX
+ int r;
+ security_context_t fcon = NULL;
+
+ if (!use_selinux() || !label_hnd)
+ goto skipped;
+
+ if (path_is_absolute(path))
+ r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFDIR);
+ else {
+ char *newpath;
+
+ newpath = path_make_absolute_cwd(path);
+ if (!newpath)
+ return -ENOMEM;
+
+ r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFDIR);
+ free(newpath);
+ }
+
+ if (r == 0)
+ r = setfscreatecon(fcon);
+
+ if (r < 0 && errno != ENOENT) {
+ log_error("Failed to set security context %s for %s: %m", fcon, path);
+
+ if (security_getenforce() == 1) {
+ r = -errno;
+ goto finish;
+ }
+ }
+
+ r = mkdir(path, mode);
+ if (r < 0)
+ r = -errno;
+
+finish:
+ setfscreatecon(NULL);
+ freecon(fcon);
+
+ return r;
+
+skipped:
+#endif
+ return mkdir(path, mode) < 0 ? -errno : 0;
+}
+
+int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) {
+
+ /* Binds a socket and label its file system object according to the SELinux policy */
+
+#ifdef HAVE_SELINUX
+ int r;
+ security_context_t fcon = NULL;
+ const struct sockaddr_un *un;
+ char *path = NULL;
+
+ assert(fd >= 0);
+ assert(addr);
+ assert(addrlen >= sizeof(sa_family_t));
+
+ if (!use_selinux() || !label_hnd)
+ goto skipped;
+
+ /* Filter out non-local sockets */
+ if (addr->sa_family != AF_UNIX)
+ goto skipped;
+
+ /* Filter out anonymous sockets */
+ if (addrlen < sizeof(sa_family_t) + 1)
+ goto skipped;
+
+ /* Filter out abstract namespace sockets */
+ un = (const struct sockaddr_un*) addr;
+ if (un->sun_path[0] == 0)
+ goto skipped;
+
+ path = strndup(un->sun_path, addrlen - offsetof(struct sockaddr_un, sun_path));
+ if (!path)
+ return -ENOMEM;
+
+ if (path_is_absolute(path))
+ r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFSOCK);
+ else {
+ char *newpath;
+
+ newpath = path_make_absolute_cwd(path);
+
+ if (!newpath) {
+ free(path);
+ return -ENOMEM;
+ }
+
+ r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFSOCK);
+ free(newpath);
+ }
+
+ if (r == 0)
+ r = setfscreatecon(fcon);
+
+ if (r < 0 && errno != ENOENT) {
+ log_error("Failed to set security context %s for %s: %m", fcon, path);
+
+ if (security_getenforce() == 1) {
+ r = -errno;
+ goto finish;
+ }
+ }
+
+ r = bind(fd, addr, addrlen);
+ if (r < 0)
+ r = -errno;
+
+finish:
+ setfscreatecon(NULL);
+ freecon(fcon);
+ free(path);
+
+ return r;
+
+skipped:
+#endif
+ return bind(fd, addr, addrlen) < 0 ? -errno : 0;
+}