smbd: Factor out safe_symlink_target_path()

Small refactoring to make filename_convert_dirfsp() itself a bit
shorter using a subroutine.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/smbd/filename.c b/source3/smbd/filename.c
index 70a34a4d3fb1bfcd6ecb29e632fa4961a4b6b2af..1f8b33c7fda9318c3f501a15c8418e8443aa8c44 100644 (file)
--- a/source3/smbd/filename.c
+++ b/source3/smbd/filename.c
@@ -950,6 +950,70 @@ static char *symlink_target_path(
        return ret;
 }
 
+static NTSTATUS safe_symlink_target_path(
+       TALLOC_CTX *mem_ctx,
+       const char *connectpath,
+       const char *name_in,
+       const char *substitute,
+       size_t unparsed,
+       char **_name_out)
+{
+       char *target = NULL;
+       char *abs_target = NULL;
+       char *abs_target_canon = NULL;
+       const char *relative = NULL;
+       char *name_out = NULL;
+       NTSTATUS status = NT_STATUS_NO_MEMORY;
+       bool in_share;
+
+       target = symlink_target_path(mem_ctx, name_in, substitute, unparsed);
+       if (target == NULL) {
+               goto fail;
+       }
+
+       DBG_DEBUG("name_in: %s, substitute: %s, unparsed: %zu, target=%s\n",
+                 name_in,
+                 substitute,
+                 unparsed,
+                 target);
+
+       if (target[0] == '/') {
+               abs_target = target;
+       } else {
+               abs_target = talloc_asprintf(
+                       target, "%s/%s", connectpath, target);
+               if (abs_target == NULL) {
+                       goto fail;
+               }
+       }
+
+       abs_target_canon = canonicalize_absolute_path(target, abs_target);
+       if (abs_target_canon == NULL) {
+               goto fail;
+       }
+
+       DBG_DEBUG("abs_target_canon=%s\n", abs_target_canon);
+
+       in_share = subdir_of(
+               connectpath, strlen(connectpath), abs_target_canon, &relative);
+       if (!in_share) {
+               DBG_DEBUG("wide link to %s\n", abs_target_canon);
+               status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
+               goto fail;
+       }
+
+       name_out = talloc_strdup(mem_ctx, relative);
+       if (name_out == NULL) {
+               goto fail;
+       }
+
+       status = NT_STATUS_OK;
+       *_name_out = name_out;
+fail:
+       TALLOC_FREE(target);
+       return status;
+}
+
 /*
  * Split up name_in as sent by the client into a directory pathref fsp
  * and a relative smb_filename.
@@ -1367,14 +1431,10 @@ NTSTATUS filename_convert_dirfsp(
        struct smb_filename **_smb_fname)
 {
        char *substitute = NULL;
-       const char *relative = NULL;
        size_t unparsed = 0;
        NTSTATUS status;
        char *target = NULL;
-       char *abs_target = NULL;
-       char *abs_target_canon = NULL;
        size_t symlink_redirects = 0;
-       bool in_share;
 
 next:
        if (symlink_redirects > 40) {
@@ -1412,45 +1472,17 @@ next:
         * resolve all symlinks locally.
         */
 
-       target = symlink_target_path(mem_ctx, name_in, substitute, unparsed);
-       if (target == NULL) {
-               return NT_STATUS_NO_MEMORY;
-       }
-
-       DBG_DEBUG("name_in: %s, substitute: %s, unparsed: %zu, target=%s\n",
-                 name_in,
-                 substitute,
-                 unparsed,
-                 target);
-
-       if (target[0] == '/') {
-               abs_target = target;
-       } else {
-               abs_target = talloc_asprintf(
-                       mem_ctx, "%s/%s", conn->connectpath, target);
-               if (abs_target == NULL) {
-                       return NT_STATUS_NO_MEMORY;
-               }
-       }
-
-       abs_target_canon = canonicalize_absolute_path(mem_ctx, abs_target);
-       if (abs_target_canon == NULL) {
-               return NT_STATUS_NO_MEMORY;
-       }
-
-       DBG_DEBUG("abs_target_canon=%s\n", abs_target_canon);
-
-       in_share = subdir_of(
+       status = safe_symlink_target_path(
+               mem_ctx,
                conn->connectpath,
-               strlen(conn->connectpath),
-               abs_target_canon,
-               &relative);
-       if (!in_share) {
-               DBG_DEBUG("wide link to %s\n", abs_target_canon);
-               return NT_STATUS_OBJECT_PATH_NOT_FOUND;
+               name_in,
+               substitute,
+               unparsed,
+               &target);
+       if (!NT_STATUS_IS_OK(status)) {
+               return status;
        }
-
-       name_in = talloc_strdup(mem_ctx, relative);
+       name_in = target;
 
        symlink_redirects += 1;