From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Date: Fri, 25 Apr 2008 04:30:38 +0000 (-0700)
Subject: ipv6 RAW: Disallow IPPROTO_IPV6-level IPV6_CHECKSUM socket option on ICMPv6 sockets.
X-Git-Tag: v2.6.26-rc1~1067^2~5
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1a98d05f59704d60be85b03f727964e15c77224c;p=linux-2.6

ipv6 RAW: Disallow IPPROTO_IPV6-level IPV6_CHECKSUM socket option on ICMPv6 sockets.

RFC3542 tells that IPV6_CHECKSUM socket option in the IPPROTO_IPV6
level is not allowed on ICMPv6 sockets.  IPPROTO_RAW level
IPV6_CHECKSUM socket option (a Linux extension) is still allowed.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 6193b124cb..396f0ea110 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -971,6 +971,19 @@ static int do_rawv6_setsockopt(struct sock *sk, int level, int optname,
 
 	switch (optname) {
 		case IPV6_CHECKSUM:
+			if (inet_sk(sk)->num == IPPROTO_ICMPV6 &&
+			    level == IPPROTO_IPV6) {
+				/*
+				 * RFC3542 tells that IPV6_CHECKSUM socket
+				 * option in the IPPROTO_IPV6 level is not
+				 * allowed on ICMPv6 sockets.
+				 * If you want to set it, use IPPROTO_RAW
+				 * level IPV6_CHECKSUM socket option
+				 * (Linux extension).
+				 */
+				return -EINVAL;
+			}
+
 			/* You may get strange result with a positive odd offset;
 			   RFC2292bis agrees with me. */
 			if (val > 0 && (val&1))
@@ -1046,6 +1059,11 @@ static int do_rawv6_getsockopt(struct sock *sk, int level, int optname,
 
 	switch (optname) {
 	case IPV6_CHECKSUM:
+		/*
+		 * We allow getsockopt() for IPPROTO_IPV6-level
+		 * IPV6_CHECKSUM socket option on ICMPv6 sockets
+		 * since RFC3542 is silent about it.
+		 */
 		if (rp->checksum == 0)
 			val = -1;
 		else