smack: relabel directories and files created by systemd

[elogind.git] / src / shared / label.c

diff --git a/src/shared/label.c b/src/shared/label.c
index a8bf6bd4f93982ce46ba83edc28b982d01693def..3632e3ebf9fbd617c3cb91e23a598be76a2a3b77 100644 (file)
--- a/src/shared/label.c
+++ b/src/shared/label.c
@@ -20,7 +20,6 @@
 ***/
 
 #include <errno.h>
-#include <sys/stat.h>
 #include <unistd.h>
 #include <malloc.h>
 #include <sys/socket.h>
@@ -41,6 +40,48 @@
 
 static struct selabel_handle *label_hnd = NULL;
 
+#endif
+#ifdef HAVE_SMACK
+#include <sys/xattr.h>
+#include <string.h>
+#define FLOOR_LABEL    "_"
+#define STAR_LABEL     "*"
+
+static void smack_relabel_in_dev(const char *path) {
+        struct stat sb;
+        const char *label;
+        int r;
+
+        /*
+         * Path must be in /dev and must exist
+         */
+        if (!path_equal(path, "/dev") &&
+            !path_startswith(path, "/dev"))
+                return;
+
+        r = lstat(path, &sb);
+        if (r < 0)
+                return;
+
+        /*
+         * Label directories and character devices "*".
+         * Label symlinks "_".
+         * Don't change anything else.
+         */
+        if (S_ISDIR(sb.st_mode))
+                label = STAR_LABEL;
+        else if (S_ISLNK(sb.st_mode))
+                label = FLOOR_LABEL;
+        else if (S_ISCHR(sb.st_mode))
+                label = STAR_LABEL;
+        else
+                return;
+
+        r = setxattr(path, "security.SMACK64", label, strlen(label), 0);
+        if (r < 0)
+                log_error("Smack relabeling \"%s\" %s", path, strerror(errno));
+        return;
+}
 #endif
 
 int label_init(const char *prefix) {
@@ -82,7 +123,7 @@ int label_init(const char *prefix) {
                 l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0;
 
                 log_debug("Successfully loaded SELinux database in %s, size on heap is %iK.",
-                          format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp),
+                          format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp, 0),
                           (l+1023)/1024);
         }
 #endif
@@ -131,6 +172,9 @@ int label_fix(const char *path, bool ignore_enoent, bool ignore_erofs) {
                 r = security_getenforce() == 1 ? -errno : 0;
         }
 #endif
+#ifdef HAVE_SMACK
+        smack_relabel_in_dev(path);
+#endif
 
         return r;
 }
@@ -138,7 +182,10 @@ int label_fix(const char *path, bool ignore_enoent, bool ignore_erofs) {
 void label_finish(void) {
 
 #ifdef HAVE_SELINUX
-        if (use_selinux() && label_hnd)
+        if (!use_selinux())
+                return;
+
+        if (label_hnd)
                 selabel_close(label_hnd);
 #endif
 }
@@ -205,6 +252,9 @@ int label_context_set(const char *path, mode_t mode) {
         if (r < 0 && security_getenforce() == 0)
                 r = 0;
 #endif
+#ifdef HAVE_SMACK
+        smack_relabel_in_dev(path);
+#endif
 
         return r;
 }
@@ -257,27 +307,26 @@ void label_free(const char *label) {
 #endif
 }
 
-int label_mkdir(const char *path, mode_t mode, bool apply) {
+int label_mkdir(const char *path, mode_t mode) {
+        int r;
 
-        /* Creates a directory and labels it according to the SELinux policy */
 #ifdef HAVE_SELINUX
-        int r;
+        /* Creates a directory and labels it according to the SELinux policy */
         security_context_t fcon = NULL;
 
-        if (!apply || !use_selinux() || !label_hnd)
+        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;
+                _cleanup_free_ 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)
@@ -304,7 +353,13 @@ finish:
 
 skipped:
 #endif
-        return mkdir(path, mode) < 0 ? -errno : 0;
+        r = mkdir(path, mode);
+        if (r)
+                return -errno;
+#ifdef HAVE_SMACK
+        smack_relabel_in_dev(path);
+#endif
+        return 0;
 }
 
 int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) {
@@ -312,10 +367,10 @@ 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;
+        char *path;
+        int r;
 
         assert(fd >= 0);
         assert(addr);
@@ -337,24 +392,18 @@ int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) {
         if (un->sun_path[0] == 0)
                 goto skipped;
 
-        path = strndup(un->sun_path, addrlen - offsetof(struct sockaddr_un, sun_path));
-        if (!path)
-                return -ENOMEM;
+        path = strndupa(un->sun_path, addrlen - offsetof(struct sockaddr_un, sun_path));
 
         if (path_is_absolute(path))
                 r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFSOCK);
         else {
-                char *newpath;
+                _cleanup_free_ char *newpath;
 
                 newpath = path_make_absolute_cwd(path);
-
-                if (!newpath) {
-                        free(path);
+                if (!newpath)
                         return -ENOMEM;
-                }
 
                 r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFSOCK);
-                free(newpath);
         }
 
         if (r == 0)
@@ -376,7 +425,6 @@ int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) {
 finish:
         setfscreatecon(NULL);
         freecon(fcon);
-        free(path);
 
         return r;
 
@@ -384,3 +432,15 @@ skipped:
 #endif
         return bind(fd, addr, addrlen) < 0 ? -errno : 0;
 }
+
+int label_apply(const char *path, const char *label) {
+        int r = 0;
+
+#ifdef HAVE_SELINUX
+        if (!use_selinux())
+                return 0;
+
+        r = setfilecon(path, (char *)label);
+#endif
+        return r;
+}