lib/fs/readlink/, lib/: areadlink(): Move and rename function

Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/Makefile.am

@@ -103,6 +103,8 @@ libshadow_la_SOURCES = \
 	find_new_sub_gids.c \
 	find_new_sub_uids.c \
 	fputsx.c \
+	fs/readlink/areadlink.c \
+	fs/readlink/areadlink.h \
 	fs/readlink/readlinknul.c \
 	fs/readlink/readlinknul.h \
 	get_pid.c \

lib/copydir.c

@@ -19,10 +19,9 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "alloc/malloc.h"
 #include "alloc/x/xmalloc.h"
 #include "attr.h"
-#include "fs/readlink/readlinknul.h"
+#include "fs/readlink/areadlink.h"
 #include "prototypes.h"
 #include "defines.h"
 #ifdef WITH_SELINUX
@@ -69,7 +68,6 @@ static int copy_dir (const struct path_info *src, const struct path_info *dst,
                      const struct stat *statp, const struct timespec mt[],
                      uid_t old_uid, uid_t new_uid,
                      gid_t old_gid, gid_t new_gid);
-static /*@null@*/char *readlink_malloc (const char *filename);
 static int copy_symlink (const struct path_info *src, const struct path_info *dst,
                          MAYBE_UNUSED bool reset_selinux,
                          const struct stat *statp, const struct timespec mt[],
@@ -539,35 +537,6 @@ static int copy_dir (const struct path_info *src, const struct path_info *dst,
 	return err;
 }
 
-/*
- * readlink_malloc - wrapper for readlink
- *
- * return NULL on error.
- * The return string shall be freed by the caller.
- */
-static /*@null@*/char *readlink_malloc (const char *filename)
-{
-	size_t size = 1024;
-
-	while (true) {
-		int  len;
-		char *buffer = MALLOC(size, char);
-		if (NULL == buffer) {
-			return NULL;
-		}
-
-		len = readlinknul(filename, buffer, size);
-		if (len != -1)
-			return buffer;
-
-		free(buffer);
-		if (errno != E2BIG)
-			return NULL;
-
-		size *= 2;
-	}
-}
-
 /*
  * copy_symlink - copy a symlink
  *
@@ -598,10 +567,9 @@ static int copy_symlink (const struct path_info *src, const struct path_info *ds
 	 * destination directory name.
 	 */
 
-	oldlink = readlink_malloc (src->full_path);
-	if (NULL == oldlink) {
+	oldlink = areadlink(src->full_path);
+	if (NULL == oldlink)
 		return -1;
-	}
 
 	/* If src was a link to an entry of the src_orig directory itself,
 	 * create a link to the corresponding entry in the dst_orig

lib/fs/readlink/areadlink.c

@@ -0,0 +1,10 @@
+// SPDX-FileCopyrightText: 2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include "fs/readlink/areadlink.h"
+
+
+extern inline char *areadlink(const char *path);

lib/fs/readlink/areadlink.h

@@ -0,0 +1,51 @@
+// SPDX-FileCopyrightText: 2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#ifndef SHADOW_INCLUDE_LIB_FS_READLINK_AREADLINK_H_
+#define SHADOW_INCLUDE_LIB_FS_READLINK_AREADLINK_H_
+
+
+#include <config.h>
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+#include "alloc/malloc.h"
+#include "attr.h"
+#include "fs/readlink/readlinknul.h"
+
+
+ATTR_STRING(1)
+inline char *areadlink(const char *path);
+
+
+// Similar to readlink(2), but allocate and terminate the string.
+inline char *
+areadlink(const char *filename)
+{
+	size_t size = 1024;
+
+	while (true) {
+		int  len;
+		char *buffer = MALLOC(size, char);
+		if (NULL == buffer) {
+			return NULL;
+		}
+
+		len = readlinknul(filename, buffer, size);
+		if (len != -1)
+			return buffer;
+
+		free(buffer);
+		if (errno != E2BIG)
+			return NULL;
+
+		size *= 2;
+	}
+}
+
+
+#endif  // include guard