[systemd-devel] [PATCH 2/4] Allow systemd-tmpfiles to set the file/directory attributes

[Goffredo Baroncelli]

Allow systemd-tmpfiles to set the file/directory attributes, like chattr(1)
does. Two more commands are added: 'H' and 'h' to set the attributes,
recursively and not.
---
 src/tmpfiles/tmpfiles.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)

diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index c948d4d..165605f 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -40,6 +40,7 @@
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/xattr.h>
+#include <linux/fs.h>
 
 #include "log.h"
 #include "util.h"
@@ -90,6 +91,8 @@ typedef enum ItemType {
         ADJUST_MODE = 'm', /* legacy, 'z' is identical to this */
         RELABEL_PATH = 'z',
         RECURSIVE_RELABEL_PATH = 'Z',
+        SET_ATTRIB = 'h',
+        RECURSIVE_SET_ATTRIB = 'H',
 } ItemType;
 
 typedef struct Item {
@@ -108,12 +111,15 @@ typedef struct Item {
         usec_t age;
 
         dev_t major_minor;
+        int attrib_value;
+        int attrib_mask;
 
         bool uid_set:1;
         bool gid_set:1;
         bool mode_set:1;
         bool age_set:1;
         bool mask_perms:1;
+        bool attrib_set:1;
 
         bool keep_first_level:1;
 
@@ -762,6 +768,115 @@ static int path_set_acls(Item *item, const char *path) {
         return 0;
 }
 
+static int get_attrib_from_arg(Item *item) {
+        static const struct { int value; char ch; } attributes[] = {
+                { FS_NOATIME_FL, 'A' },   /* do not update atime */
+                { FS_SYNC_FL, 'S' },      /* Synchronous updates */
+                { FS_DIRSYNC_FL, 'D' },   /* dirsync behaviour (directories only) */
+                { FS_APPEND_FL, 'a' },    /* writes to file may only append */
+                { FS_COMPR_FL, 'c' },     /* Compress file */
+                { FS_NODUMP_FL, 'd' },    /* do not dump file */
+                { FS_EXTENT_FL, 'e'},     /* Top of directory hierarchies*/
+                { FS_IMMUTABLE_FL, 'i' }, /* Immutable file */
+                { FS_JOURNAL_DATA_FL, 'j' }, /* Reserved for ext3 */
+                { FS_SECRM_FL, 's' },     /* Secure deletion */
+                { FS_UNRM_FL, 'u' },      /* Undelete */
+                { FS_NOTAIL_FL, 't' },    /* file tail should not be merged */
+                { FS_TOPDIR_FL, 'T' },    /* Top of directory hierarchies*/
+                { FS_NOCOW_FL, 'C' },     /* Do not cow file */
+                { 0, 0 }
+        };
+        char *p = item->argument;
+        enum {
+                MODE_ADD,
+                MODE_DEL,
+                MODE_SET
+        } mode = MODE_ADD;
+        unsigned long value = 0, mask = 0;
+
+        if (!p) {
+                log_error("\"%s\": setting ATTR need an argument", item->path);
+                return -EINVAL;
+        }
+
+        if (*p == '+') {
+                mode = MODE_ADD;
+                p++;
+        } else if (*p == '-') {
+                mode = MODE_DEL;
+                p++;
+        } else  if (*p == '=') {
+                mode = MODE_SET;
+                p++;
+        }
+
+        if (!*p && mode != MODE_SET) {
+                log_error("\"%s\": setting ATTR: argument is empty", item->path);
+                return -EINVAL;
+        }
+        for (; *p ; p++) {
+                int i;
+                for (i = 0; attributes[i].ch && attributes[i].ch != *p; i++)
+                        ;
+                if (!attributes[i].ch) {
+                        log_error("\"%s\": setting ATTR: unknown attr '%c'", item->path, *p);
+                        return -EINVAL;
+                }
+                if (mode == MODE_ADD || mode == MODE_SET)
+                        value |= attributes[i].value;
+                else
+                        value &= ~attributes[i].value;
+                mask |= attributes[i].value;
+        }
+
+        if (mode == MODE_SET) {
+                int i;
+                for (i = 0; attributes[i].ch; i++)
+                        mask |= attributes[i].value;
+        }
+
+        assert(mask);
+
+        item->attrib_mask = mask;
+        item->attrib_value = value;
+        item->attrib_set = true;
+
+        return 0;
+
+}
+
+static int path_set_attrib(Item *item, const char *path) {
+        _cleanup_close_ int fd = -1;
+        int r;
+        unsigned f;
+        struct stat st;
+
+        /* do nothing */
+        if (item->attrib_mask == 0 || !item->attrib_set)
+                return 0;
+
+        if (lstat(path, &st) == 0 &&
+            !S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode)) {
+                return 0;
+        }
+
+        fd = open(path, O_RDONLY|O_NONBLOCK|O_CLOEXEC);
+
+        if (fd < 0)
+                return log_error_errno(errno, "Cannot open \"%s\": %m", path);
+
+        f = item->attrib_value & item->attrib_mask;
+        if (!S_ISDIR(st.st_mode))
+                f &= ~FS_DIRSYNC_FL;
+        r = change_attr_fd(fd, f, item->attrib_mask);
+        if (r < 0)
+                return log_error_errno(errno,
+                        "Cannot set attrib for \"%s\", value=0x%08x, mask=0x%08x: %m",
+                        path, item->attrib_value, item->attrib_mask);
+
+        return 0;
+}
+
 static int write_one_file(Item *i, const char *path) {
         _cleanup_close_ int fd = -1;
         int flags, r = 0;
@@ -1203,6 +1318,18 @@ static int create_item(Item *i) {
                 if (r < 0)
                         return r;
                 break;
+
+        case SET_ATTRIB:
+                r = glob_item(i, path_set_attrib, false);
+                if (r < 0)
+                        return r;
+                break;
+
+        case RECURSIVE_SET_ATTRIB:
+                r = glob_item(i, path_set_attrib, true);
+                if (r < 0)
+                        return r;
+                break;
         }
 
         log_debug("%s created successfully.", i->path);
@@ -1269,6 +1396,8 @@ static int remove_item(Item *i) {
         case RECURSIVE_SET_XATTR:
         case SET_ACL:
         case RECURSIVE_SET_ACL:
+        case SET_ATTRIB:
+        case RECURSIVE_SET_ATTRIB:
                 break;
 
         case REMOVE_PATH:
@@ -1653,6 +1782,17 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
                         return r;
                 break;
 
+        case SET_ATTRIB:
+        case RECURSIVE_SET_ATTRIB:
+                if (!i.argument) {
+                        log_error("[%s:%u] Set attrib requires argument.", fname, line);
+                        return -EBADMSG;
+                }
+                r = get_attrib_from_arg(&i);
+                if (r < 0)
+                        return r;
+                break;
+
         default:
                 log_error("[%s:%u] Unknown command type '%c'.", fname, line, (char) i.type);
                 return -EBADMSG;
-- 
2.1.4