[BZ #4181]

2007-03-15  Jakub Jelinek  <jakub@redhat.com>
	[BZ #4181]
	* inet/inet6_opt.c (add_padding): Only insert padding if npad > 0.
	(inet6_opt_append): Don't check extlen is big enough if extbuf
	is NULL.
	(inet6_opt_finish): Likewise.
	* inet/Makefile (tests): Add test-inet6_opt.
	* inet/test-inet6_opt.c: New test.

	* sysdeps/unix/sysv/linux/ifaddrs.c (__netlink_request): Never
	reallocate the buffer, instead fail for MSG_TRUNC or for EBUSY
	NLMSG_ERR.  Instead use a page sized buffer.
	* sysdeps/unix/sysv/linux/check_pf.c (make_request): Use page sized
	buffer.

1 files changed, 18 insertions, 18 deletions

diff --git a/inet/inet6_opt.c b/inet/inet6_opt.c
index bddb85182b..17d3fee213 100644
--- a/inet/inet6_opt.c
+++ b/inet/inet6_opt.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2006 Free Software Foundation, Inc.
+/* Copyright (C) 2006, 2007 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2006.
 
@@ -51,7 +51,7 @@ add_padding (uint8_t *extbuf, int offset, int npad)
 {
   if (npad == 1)
     extbuf[offset] = IP6OPT_PAD1;
-  else
+  else if (npad > 0)
     {
       struct ip6_opt *pad_opt = (struct ip6_opt *) (extbuf + offset);
 
@@ -102,21 +102,17 @@ inet6_opt_append (void *extbuf, socklen_t extlen, int offset, uint8_t type,
   int data_offset = offset + sizeof (struct ip6_opt);
   int npad = (align - data_offset % align) & (align - 1);
 
-  /* Now we can check whether the buffer is large enough.  */
-  if (data_offset + npad + len > extlen)
-    return -1;
-
-  if (npad != 0)
+  if (extbuf != NULL)
     {
-      if (extbuf != NULL)
-	add_padding (extbuf, offset, npad);
+      /* Now we can check whether the buffer is large enough.  */
+      if (data_offset + npad + len > extlen)
+	return -1;
+
+      add_padding (extbuf, offset, npad);
 
       offset += npad;
-    }
 
-  /* Now prepare the option itself.  */
-  if (extbuf != NULL)
-    {
+      /* Now prepare the option itself.  */
       struct ip6_opt *opt = (struct ip6_opt *) ((uint8_t *) extbuf + offset);
 
       opt->ip6o_type = type;
@@ -124,6 +120,8 @@ inet6_opt_append (void *extbuf, socklen_t extlen, int offset, uint8_t type,
 
       *databufp = opt + 1;
     }
+  else
+    offset += npad;
 
   return offset + sizeof (struct ip6_opt) + len;
 }
@@ -145,12 +143,14 @@ inet6_opt_finish (void *extbuf, socklen_t extlen, int offset)
   /* Required padding at the end.  */
   int npad = (8 - (offset & 7)) & 7;
 
-  /* Make sure the buffer is large enough.  */
-  if (offset + npad > extlen)
-    return -1;
-
   if (extbuf != NULL)
-    add_padding (extbuf, offset, npad);
+    {
+      /* Make sure the buffer is large enough.  */
+      if (offset + npad > extlen)
+	return -1;
+
+      add_padding (extbuf, offset, npad);
+    }
 
   return offset + npad;
 }