return ACL_ERROR;
}
+ /* This can allocate memory, so from here on out we have to jump to
+ the "cleanup" label to exit. */
+ void* entry_qualifier = acl_get_qualifier(entry);
+ if (entry_qualifier == NULL &&
+ (entry_tag == ACL_USER || entry_tag == ACL_GROUP)) {
+ /* acl_get_qualifier() can return NULL, but it shouldn't for
+ ACL_USER or ACL_GROUP entries. */
+ perror("acl_update_entry (acl_get_qualifier)");
+ return ACL_ERROR;
+ }
+
+ /* Our return value. Default to failure, and change to success if we
+ actually update something. */
+ int result = ACL_FAILURE;
+
acl_entry_t existing_entry;
/* Loop through the given ACL looking for matching entries. */
- int result = acl_get_entry(aclp, ACL_FIRST_ENTRY, &existing_entry);
+ int get_entry_result = acl_get_entry(aclp, ACL_FIRST_ENTRY, &existing_entry);
- while (result == ACL_SUCCESS) {
+ while (get_entry_result == ACL_SUCCESS) {
acl_tag_t existing_tag = ACL_UNDEFINED_TAG;
if (acl_get_tag_type(existing_entry, &existing_tag) == ACL_ERROR) {
perror("set_acl_tag_permset (acl_get_tag_type)");
- return ACL_ERROR;
+ result = ACL_ERROR;
+ goto cleanup;
}
if (existing_tag == entry_tag) {
- /* If we update something, we're done and return ACL_SUCCESS */
- if (acl_set_permset(existing_entry, entry_permset) == ACL_ERROR) {
- perror("acl_update_entry (acl_set_permset)");
- return ACL_ERROR;
+ /* Our tag types match, but if we have a named user or group
+ entry, then we need to check that the user/group (that is,
+ the qualifier) matches too. */
+ bool qualifiers_match = false;
+
+ /* There are three ways the qualifiers can match... */
+ void* existing_qualifier = acl_get_qualifier(existing_entry);
+ if (existing_qualifier == NULL) {
+ if (existing_tag == ACL_USER || existing_tag == ACL_GROUP) {
+ perror("acl_update_entry (acl_get_qualifier)");
+ result = ACL_ERROR;
+ goto cleanup;
+ }
+ else {
+ /* First, we could be dealing with an entry that isn't a
+ named user or group, in which case they "match
+ vacuously." */
+ qualifiers_match = true;
+ }
+ }
+
+ /* Otherwise, we have to have matching UIDs or GIDs. */
+ if (entry_tag == ACL_USER) {
+ qualifiers_match = ( *((uid_t*)existing_qualifier)
+ ==
+ *((uid_t*)entry_qualifier) );
+ }
+ else if (entry_tag == ACL_GROUP) {
+ qualifiers_match = ( *((gid_t*)existing_qualifier)
+ ==
+ *((gid_t*)entry_qualifier) );
}
- return ACL_SUCCESS;
+ /* Be sure to free this inside the loop, where memory is allocated. */
+ acl_free(existing_qualifier);
+
+ if (qualifiers_match) {
+ /* If we update something, we're done and return ACL_SUCCESS */
+ if (acl_set_permset(existing_entry, entry_permset) == ACL_ERROR) {
+ perror("acl_update_entry (acl_set_permset)");
+ result = ACL_ERROR;
+ goto cleanup;
+ }
+
+ result = ACL_SUCCESS;
+ goto cleanup;
+ }
}
- result = acl_get_entry(aclp, ACL_NEXT_ENTRY, &existing_entry);
+ get_entry_result = acl_get_entry(aclp, ACL_NEXT_ENTRY, &existing_entry);
}
/* This catches both the initial acl_get_entry and the ones at the
end of the loop. */
- if (result == ACL_ERROR) {
+ if (get_entry_result == ACL_ERROR) {
perror("acl_update_entry (acl_get_entry)");
- return ACL_ERROR;
+ result = ACL_ERROR;
}
- return ACL_FAILURE;
+ cleanup:
+ acl_free(entry_qualifier);
+ return result;
}
}
char* parent = dirname(dirname_path_copy);
+ basename_path_copy = strdup(path);
+ if (basename_path_copy == NULL) {
+ perror("apply_default_acl (strdup)");
+ result = ACL_ERROR;
+ goto cleanup;
+ }
+ char* child = basename(basename_path_copy);
+
/* Just kidding, if the path is "." or "..", then dirname will do
* the wrong thing and give us "." as its parent, too. So, we handle
- * those as special cases.
+ * those as special cases. We use "child" instead of "path" here to
+ * catch things like "./" and "../"
*/
- bool path_is_dots = strcmp(path, ".") == 0 || strcmp(path, "..") == 0;
+ bool path_is_dots = strcmp(child, ".") == 0 || strcmp(child, "..") == 0;
char dots_parent[6] = "../";
if (path_is_dots) {
- parent = strcat(dots_parent, path);
+ /* We know that "child" contains no more than two characters here, and
+ using strncat to enforce that belief keeps clang-tidy happy. */
+ parent = strncat(dots_parent, child, 2);
}
parent_fd = safe_open(parent, O_DIRECTORY | O_NOFOLLOW);
}
/* We already obtained the parent fd safely, so if we use the
- basename of path here instead of the full thing, then we can get
- away with using openat() and spare ourselves the slowness of
- another safe_open(). */
- basename_path_copy = strdup(path);
- if (basename_path_copy == NULL) {
- perror("apply_default_acl (strdup)");
- result = ACL_ERROR;
- goto cleanup;
- }
-
- /* If the basename is "." or "..", then we don't want to open it
- relative to the parent_fd, so we need another special case for
- those paths. */
+ * basename of path here instead of the full thing, then we can get
+ * away with using openat() and spare ourselves the slowness of
+ * another safe_open().
+ *
+ * Note that if the basename is "." or "..", then we don't want to
+ * open it relative to the parent_fd, so we need another special
+ * case for those paths here.
+ */
if (path_is_dots) {
- fd = open(path, O_NOFOLLOW);
+ fd = open(child, O_NOFOLLOW);
}
else {
- fd = openat(parent_fd, basename(basename_path_copy), O_NOFOLLOW);
+ fd = openat(parent_fd, child, O_NOFOLLOW);
}
if (fd == OPEN_ERROR) {
if (errno == ELOOP || errno == ENOTDIR) {