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-rw-r--r--src/libbasic/smack-util.c241
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diff --git a/src/libbasic/smack-util.c b/src/libbasic/smack-util.c
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+/***
+ This file is part of systemd.
+
+ Copyright 2013 Intel Corporation
+
+ Author: Auke Kok <auke-jan.h.kok@intel.com>
+
+ systemd is free software; you can redistribute it and/or modify it
+ 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
+ Lesser General Public License for more details.
+
+ 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 <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/xattr.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fileio.h"
+#include "log.h"
+#include "macro.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "smack-util.h"
+#include "string-table.h"
+#include "xattr-util.h"
+
+#ifdef HAVE_SMACK
+bool mac_smack_use(void) {
+ static int cached_use = -1;
+
+ if (cached_use < 0)
+ cached_use = access("/sys/fs/smackfs/", F_OK) >= 0;
+
+ return cached_use;
+}
+
+static const char* const smack_attr_table[_SMACK_ATTR_MAX] = {
+ [SMACK_ATTR_ACCESS] = "security.SMACK64",
+ [SMACK_ATTR_EXEC] = "security.SMACK64EXEC",
+ [SMACK_ATTR_MMAP] = "security.SMACK64MMAP",
+ [SMACK_ATTR_TRANSMUTE] = "security.SMACK64TRANSMUTE",
+ [SMACK_ATTR_IPIN] = "security.SMACK64IPIN",
+ [SMACK_ATTR_IPOUT] = "security.SMACK64IPOUT",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(smack_attr, SmackAttr);
+
+int mac_smack_read(const char *path, SmackAttr attr, char **label) {
+ assert(path);
+ assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
+ assert(label);
+
+ if (!mac_smack_use())
+ return 0;
+
+ return getxattr_malloc(path, smack_attr_to_string(attr), label, true);
+}
+
+int mac_smack_read_fd(int fd, SmackAttr attr, char **label) {
+ assert(fd >= 0);
+ assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
+ assert(label);
+
+ if (!mac_smack_use())
+ return 0;
+
+ return fgetxattr_malloc(fd, smack_attr_to_string(attr), label);
+}
+
+int mac_smack_apply(const char *path, SmackAttr attr, const char *label) {
+ int r;
+
+ assert(path);
+ assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
+
+ if (!mac_smack_use())
+ return 0;
+
+ if (label)
+ r = lsetxattr(path, smack_attr_to_string(attr), label, strlen(label), 0);
+ else
+ r = lremovexattr(path, smack_attr_to_string(attr));
+ if (r < 0)
+ return -errno;
+
+ return 0;
+}
+
+int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) {
+ int r;
+
+ assert(fd >= 0);
+ assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
+
+ if (!mac_smack_use())
+ return 0;
+
+ if (label)
+ r = fsetxattr(fd, smack_attr_to_string(attr), label, strlen(label), 0);
+ else
+ r = fremovexattr(fd, smack_attr_to_string(attr));
+ if (r < 0)
+ return -errno;
+
+ return 0;
+}
+
+int mac_smack_apply_pid(pid_t pid, const char *label) {
+ const char *p;
+ int r = 0;
+
+ assert(label);
+
+ if (!mac_smack_use())
+ return 0;
+
+ p = procfs_file_alloca(pid, "attr/current");
+ r = write_string_file(p, label, 0);
+ if (r < 0)
+ return r;
+
+ return r;
+}
+
+int mac_smack_fix(const char *path, bool ignore_enoent, bool ignore_erofs) {
+ struct stat st;
+ int r = 0;
+
+ assert(path);
+
+ if (!mac_smack_use())
+ return 0;
+
+ /*
+ * Path must be in /dev and must exist
+ */
+ if (!path_startswith(path, "/dev"))
+ return 0;
+
+ r = lstat(path, &st);
+ if (r >= 0) {
+ const char *label;
+
+ /*
+ * Label directories and character devices "*".
+ * Label symlinks "_".
+ * Don't change anything else.
+ */
+
+ if (S_ISDIR(st.st_mode))
+ label = SMACK_STAR_LABEL;
+ else if (S_ISLNK(st.st_mode))
+ label = SMACK_FLOOR_LABEL;
+ else if (S_ISCHR(st.st_mode))
+ label = SMACK_STAR_LABEL;
+ else
+ return 0;
+
+ r = lsetxattr(path, "security.SMACK64", label, strlen(label), 0);
+
+ /* If the FS doesn't support labels, then exit without warning */
+ if (r < 0 && errno == EOPNOTSUPP)
+ return 0;
+ }
+
+ if (r < 0) {
+ /* Ignore ENOENT in some cases */
+ if (ignore_enoent && errno == ENOENT)
+ return 0;
+
+ if (ignore_erofs && errno == EROFS)
+ return 0;
+
+ r = log_debug_errno(errno, "Unable to fix SMACK label of %s: %m", path);
+ }
+
+ return r;
+}
+
+int mac_smack_copy(const char *dest, const char *src) {
+ int r = 0;
+ _cleanup_free_ char *label = NULL;
+
+ assert(dest);
+ assert(src);
+
+ r = mac_smack_read(src, SMACK_ATTR_ACCESS, &label);
+ if (r < 0)
+ return r;
+
+ r = mac_smack_apply(dest, SMACK_ATTR_ACCESS, label);
+ if (r < 0)
+ return r;
+
+ return r;
+}
+
+#else
+bool mac_smack_use(void) {
+ return false;
+}
+
+int mac_smack_read(const char *path, SmackAttr attr, char **label) {
+ return -EOPNOTSUPP;
+}
+
+int mac_smack_read_fd(int fd, SmackAttr attr, char **label) {
+ return -EOPNOTSUPP;
+}
+
+int mac_smack_apply(const char *path, SmackAttr attr, const char *label) {
+ return 0;
+}
+
+int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) {
+ return 0;
+}
+
+int mac_smack_apply_pid(pid_t pid, const char *label) {
+ return 0;
+}
+
+int mac_smack_fix(const char *path, bool ignore_enoent, bool ignore_erofs) {
+ return 0;
+}
+
+int mac_smack_copy(const char *dest, const char *src) {
+ return 0;
+}
+#endif