inet: Add __inet6_scopeid_pton function [BZ #20611]

__inet6_scopeid_pton implements strict validation of numeric scope IDs.
Use it in getaddrinfo and __res_vinit.

1 files changed, 63 insertions, 0 deletions

diff --git a/inet/inet6_scopeid_pton.c b/inet/inet6_scopeid_pton.c
new file mode 100644
index 0000000000..aa37392771
--- /dev/null
+++ b/inet/inet6_scopeid_pton.c
@@ -0,0 +1,63 @@
+/* Convert an IPv6 scope ID from text to the internal representation.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <net-internal.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <locale.h>
+#include <net/if.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/* Parse SOURCE as a scope ID for ADDRESS.  Return 0 on success and -1
+   on error.  */
+internal_function int
+__inet6_scopeid_pton (const struct in6_addr *address, const char *scope,
+                      uint32_t *result)
+{
+  if (IN6_IS_ADDR_LINKLOCAL (address)
+      || IN6_IS_ADDR_MC_LINKLOCAL (address))
+    {
+      uint32_t number = __if_nametoindex (scope);
+      if (number != 0)
+        {
+          *result = number;
+          return 0;
+        }
+    }
+
+  if (isdigit_l (scope[0], _nl_C_locobj_ptr))
+    {
+      char *end;
+      unsigned long long number
+        = ____strtoull_l_internal (scope, &end, /*base */ 10, /* group */ 0,
+                                   _nl_C_locobj_ptr);
+      if (*end == '\0' && number <= UINT32_MAX)
+        {
+          *result = number;
+          return 0;
+        }
+    }
+
+  __set_errno (EINVAL);
+  return -1;
+}
+
+libc_hidden_def (__inet6_scopeid_pton)