ipv6: Remove options header when setsockopt's optlen is 0
Remove the sticky Hop-by-Hop options header by calling setsockopt()
for IPV6_HOPOPTS with a zero option length, per RFC3542.
Routing header and Destination options header does the same as
Hop-by-Hop options header.
Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index c042ce1..86e28a7 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -345,18 +345,21 @@
case IPV6_DSTOPTS:
{
struct ipv6_txoptions *opt;
+
+ /* remove any sticky options header with a zero option
+ * length, per RFC3542.
+ */
if (optlen == 0)
optval = NULL;
+ else if (optlen < sizeof(struct ipv6_opt_hdr) ||
+ optlen & 0x7 || optlen > 8 * 255)
+ goto e_inval;
/* hop-by-hop / destination options are privileged option */
retv = -EPERM;
if (optname != IPV6_RTHDR && !capable(CAP_NET_RAW))
break;
- if (optlen < sizeof(struct ipv6_opt_hdr) ||
- optlen & 0x7 || optlen > 8 * 255)
- goto e_inval;
-
opt = ipv6_renew_options(sk, np->opt, optname,
(struct ipv6_opt_hdr __user *)optval,
optlen);