nspawn: rename RemountIdmapFlags enum to RemountIdmapping

This enum should be used to define various idmapping modes for bind
mounts which might be incompatible. Changing its name and the values
name to reflect that.

6 files changed, 25 insertions, 22 deletions

diff --git a/src/basic/user-util.h b/src/basic/user-util.h
index 8ae205b65e..a08683bcea 100644
--- a/src/basic/user-util.h
+++ b/src/basic/user-util.h
@@ -67,9 +67,9 @@ int take_etc_passwd_lock(const char *root);
 #define UID_NOBODY ((uid_t) 65534U)
 #define GID_NOBODY ((gid_t) 65534U)
 
-/* If REMOUNT_IDMAP_HOST_ROOT is set for remount_idmap() we'll include a mapping here that maps the host root
- * user accessing the idmapped mount to the this user ID on the backing fs. This is the last valid UID in the
- * *signed* 32bit range. You might wonder why precisely use this specific UID for this purpose? Well, we
+/* If REMOUNT_IDMAPPING_HOST_ROOT is set for remount_idmap() we'll include a mapping here that maps the host
+ * root user accessing the idmapped mount to the this user ID on the backing fs. This is the last valid UID in
+ * the *signed* 32bit range. You might wonder why precisely use this specific UID for this purpose? Well, we
  * definitely cannot use the first 0…65536 UIDs for that, since in most cases that's precisely the file range
  * we intend to map to some high UID range, and since UID mappings have to be bijective we thus cannot use
  * them at all. Furthermore the UID range beyond INT32_MAX (i.e. the range above the signed 32bit range) is
diff --git a/src/nspawn/nspawn-mount.c b/src/nspawn/nspawn-mount.c
index d5af73a3cd..5d37204f6c 100644
--- a/src/nspawn/nspawn-mount.c
+++ b/src/nspawn/nspawn-mount.c
@@ -708,10 +708,10 @@ int mount_all(const char *dest,
         return 0;
 }
 
-static int parse_mount_bind_options(const char *options, unsigned long *mount_flags, char **mount_opts, bool *idmapped) {
+static int parse_mount_bind_options(const char *options, unsigned long *mount_flags, char **mount_opts, RemountIdmapping *idmapping) {
         unsigned long flags = *mount_flags;
         char *opts = NULL;
-        bool flag_idmapped = *idmapped;
+        RemountIdmapping new_idmapping = *idmapping;
         int r;
 
         assert(options);
@@ -730,16 +730,16 @@ static int parse_mount_bind_options(const char *options, unsigned long *mount_fl
                 else if (streq(word, "norbind"))
                         flags &= ~MS_REC;
                 else if (streq(word, "idmap"))
-                        flag_idmapped = true;
+                        new_idmapping = REMOUNT_IDMAPPING_HOST_ROOT;
                 else if (streq(word, "noidmap"))
-                        flag_idmapped = false;
+                        new_idmapping = REMOUNT_IDMAPPING_NONE;
                 else
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                "Invalid bind mount option: %s", word);
         }
 
         *mount_flags = flags;
-        *idmapped = flag_idmapped;
+        *idmapping = new_idmapping;
         /* in the future mount_opts will hold string options for mount(2) */
         *mount_opts = opts;
 
@@ -751,13 +751,13 @@ static int mount_bind(const char *dest, CustomMount *m, uid_t uid_shift, uid_t u
         unsigned long mount_flags = MS_BIND | MS_REC;
         struct stat source_st, dest_st;
         int r;
-        bool idmapped = false;
+        RemountIdmapping idmapping = REMOUNT_IDMAPPING_NONE;
 
         assert(dest);
         assert(m);
 
         if (m->options) {
-                r = parse_mount_bind_options(m->options, &mount_flags, &mount_opts, &idmapped);
+                r = parse_mount_bind_options(m->options, &mount_flags, &mount_opts, &idmapping);
                 if (r < 0)
                         return r;
         }
@@ -815,8 +815,8 @@ static int mount_bind(const char *dest, CustomMount *m, uid_t uid_shift, uid_t u
                         return log_error_errno(r, "Read-only bind mount failed: %m");
         }
 
-        if (idmapped) {
-                r = remount_idmap(where, uid_shift, uid_range, REMOUNT_IDMAP_HOST_ROOT);
+        if (idmapping != REMOUNT_IDMAPPING_NONE) {
+                r = remount_idmap(where, uid_shift, uid_range, idmapping);
                 if (r < 0)
                         return log_error_errno(r, "Failed to map ids for bind mount %s: %m", where);
         }
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index ca87bffd0b..6316c03916 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -3806,7 +3806,7 @@ static int outer_child(
             IN_SET(arg_userns_ownership, USER_NAMESPACE_OWNERSHIP_MAP, USER_NAMESPACE_OWNERSHIP_AUTO) &&
             arg_uid_shift != 0) {
 
-                r = remount_idmap(directory, arg_uid_shift, arg_uid_range, REMOUNT_IDMAP_HOST_ROOT);
+                r = remount_idmap(directory, arg_uid_shift, arg_uid_range, REMOUNT_IDMAPPING_HOST_ROOT);
                 if (r == -EINVAL || ERRNO_IS_NOT_SUPPORTED(r)) {
                         /* This might fail because the kernel or file system doesn't support idmapping. We
                          * can't really distinguish this nicely, nor do we have any guarantees about the
diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c
index ba0bdbbfb6..b976d92c15 100644
--- a/src/shared/dissect-image.c
+++ b/src/shared/dissect-image.c
@@ -1380,7 +1380,7 @@ static int mount_partition(
                 (void) fs_grow(node, p);
 
         if (remap_uid_gid) {
-                r = remount_idmap(p, uid_shift, uid_range, REMOUNT_IDMAP_HOST_ROOT);
+                r = remount_idmap(p, uid_shift, uid_range, REMOUNT_IDMAPPING_HOST_ROOT);
                 if (r < 0)
                         return r;
         }
diff --git a/src/shared/mount-util.c b/src/shared/mount-util.c
index 2dd73b508d..ab1acfc2e5 100644
--- a/src/shared/mount-util.c
+++ b/src/shared/mount-util.c
@@ -1053,7 +1053,7 @@ int make_mount_point(const char *path) {
         return 1;
 }
 
-static int make_userns(uid_t uid_shift, uid_t uid_range, RemountIdmapFlags flags) {
+static int make_userns(uid_t uid_shift, uid_t uid_range, RemountIdmapping idmapping) {
         _cleanup_close_ int userns_fd = -1;
         _cleanup_free_ char *line = NULL;
 
@@ -1073,7 +1073,7 @@ static int make_userns(uid_t uid_shift, uid_t uid_range, RemountIdmapFlags flags
          * as owned by 'nobody', which is safe. (Of course, we shouldn't leave such inodes around, but always
          * chown() them to the container's own UID range, but it's good to have a safety net, in case we
          * forget it.) */
-        if (flags & REMOUNT_IDMAP_HOST_ROOT)
+        if (idmapping == REMOUNT_IDMAPPING_HOST_ROOT)
                 if (strextendf(&line,
                                UID_FMT " " UID_FMT " " UID_FMT "\n",
                                UID_MAPPED_ROOT, 0u, 1u) < 0)
@@ -1091,7 +1091,7 @@ int remount_idmap(
                 const char *p,
                 uid_t uid_shift,
                 uid_t uid_range,
-                RemountIdmapFlags flags) {
+                RemountIdmapping idmapping) {
 
         _cleanup_close_ int mount_fd = -1, userns_fd = -1;
         int r;
@@ -1107,7 +1107,7 @@ int remount_idmap(
                 return log_debug_errno(errno, "Failed to open tree of mounted filesystem '%s': %m", p);
 
         /* Create a user namespace mapping */
-        userns_fd = make_userns(uid_shift, uid_range, flags);
+        userns_fd = make_userns(uid_shift, uid_range, idmapping);
         if (userns_fd < 0)
                 return userns_fd;
 
diff --git a/src/shared/mount-util.h b/src/shared/mount-util.h
index 1797b8803c..b40687a99c 100644
--- a/src/shared/mount-util.h
+++ b/src/shared/mount-util.h
@@ -118,7 +118,8 @@ int mount_image_in_namespace(pid_t target, const char *propagate_path, const cha
 
 int make_mount_point(const char *path);
 
-typedef enum RemountIdmapFlags {
+typedef enum RemountIdmapping {
+        REMOUNT_IDMAPPING_NONE,
         /* Include a mapping from UID_MAPPED_ROOT (i.e. UID 2^31-2) on the backing fs to UID 0 on the
          * uidmapped fs. This is useful to ensure that the host root user can safely add inodes to the
          * uidmapped fs (which otherwise wouldn't work as the host root user is not defined on the uidmapped
@@ -126,10 +127,12 @@ typedef enum RemountIdmapFlags {
          * these inodes are quickly re-chown()ed to more suitable UIDs/GIDs. Any code that intends to be able
          * to add inodes to file systems mapped this way should set this flag, but given it comes with
          * certain security implications defaults to off, and requires explicit opt-in. */
-        REMOUNT_IDMAP_HOST_ROOT = 1 << 0,
-} RemountIdmapFlags;
+        REMOUNT_IDMAPPING_HOST_ROOT,
+        _REMOUNT_IDMAPPING_MAX,
+        _REMOUNT_IDMAPPING_INVALID = -EINVAL,
+} RemountIdmapping;
 
-int remount_idmap(const char *p, uid_t uid_shift, uid_t uid_range, RemountIdmapFlags flags);
+int remount_idmap(const char *p, uid_t uid_shift, uid_t uid_range, RemountIdmapping idmapping);
 
 /* Creates a mount point (not parents) based on the source path or stat - ie, a file or a directory */
 int make_mount_point_inode_from_stat(const struct stat *st, const char *dest, mode_t mode);