build-sys: split internal basic/ library from shared/

basic/      can be used by everything
            cannot use anything outside of basic/

libsystemd/ can use basic/
            cannot use shared/

shared/     can use libsystemd/

1 files changed, 208 insertions, 0 deletions

diff --git a/src/basic/smack-util.c b/src/basic/smack-util.c
new file mode 100644
index 0000000000..2e24b1ea99
--- /dev/null
+++ b/src/basic/smack-util.c
@@ -0,0 +1,208 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  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 <sys/xattr.h>
+
+#include "util.h"
+#include "process-util.h"
+#include "path-util.h"
+#include "fileio.h"
+#include "smack-util.h"
+
+#define SMACK_FLOOR_LABEL "_"
+#define SMACK_STAR_LABEL  "*"
+
+bool mac_smack_use(void) {
+#ifdef HAVE_SMACK
+        static int cached_use = -1;
+
+        if (cached_use < 0)
+                cached_use = access("/sys/fs/smackfs/", F_OK) >= 0;
+
+        return cached_use;
+#else
+        return false;
+#endif
+}
+
+int mac_smack_apply(const char *path, const char *label) {
+        int r = 0;
+
+        assert(path);
+
+#ifdef HAVE_SMACK
+        if (!mac_smack_use())
+                return 0;
+
+        if (label)
+                r = lsetxattr(path, "security.SMACK64", label, strlen(label), 0);
+        else
+                r = lremovexattr(path, "security.SMACK64");
+        if (r < 0)
+                return -errno;
+#endif
+
+        return r;
+}
+
+int mac_smack_apply_fd(int fd, const char *label) {
+        int r = 0;
+
+        assert(fd >= 0);
+
+#ifdef HAVE_SMACK
+        if (!mac_smack_use())
+                return 0;
+
+        if (label)
+                r = fsetxattr(fd, "security.SMACK64", label, strlen(label), 0);
+        else
+                r = fremovexattr(fd, "security.SMACK64");
+        if (r < 0)
+                return -errno;
+#endif
+
+        return r;
+}
+
+int mac_smack_apply_ip_out_fd(int fd, const char *label) {
+        int r = 0;
+
+        assert(fd >= 0);
+
+#ifdef HAVE_SMACK
+        if (!mac_smack_use())
+                return 0;
+
+        if (label)
+                r = fsetxattr(fd, "security.SMACK64IPOUT", label, strlen(label), 0);
+        else
+                r = fremovexattr(fd, "security.SMACK64IPOUT");
+        if (r < 0)
+                return -errno;
+#endif
+
+        return r;
+}
+
+int mac_smack_apply_ip_in_fd(int fd, const char *label) {
+        int r = 0;
+
+        assert(fd >= 0);
+
+#ifdef HAVE_SMACK
+        if (!mac_smack_use())
+                return 0;
+
+        if (label)
+                r = fsetxattr(fd, "security.SMACK64IPIN", label, strlen(label), 0);
+        else
+                r = fremovexattr(fd, "security.SMACK64IPIN");
+        if (r < 0)
+                return -errno;
+#endif
+
+        return r;
+}
+
+int mac_smack_apply_pid(pid_t pid, const char *label) {
+
+#ifdef HAVE_SMACK
+        const char *p;
+#endif
+        int r = 0;
+
+        assert(label);
+
+#ifdef HAVE_SMACK
+        if (!mac_smack_use())
+                return 0;
+
+        p = procfs_file_alloca(pid, "attr/current");
+        r = write_string_file(p, label);
+        if (r < 0)
+                return r;
+#endif
+
+        return r;
+}
+
+int mac_smack_fix(const char *path, bool ignore_enoent, bool ignore_erofs) {
+
+#ifdef HAVE_SMACK
+        struct stat st;
+#endif
+        int r = 0;
+
+        assert(path);
+
+#ifdef HAVE_SMACK
+        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);
+        }
+#endif
+
+        return r;
+}