ipv6: Allow request socks to contain IPv6 options.

If set, these will take precedence over the parent's options during
both sending and child creation.  If they're not set, the parent's
options (if any) will be used.

This is to allow the security_inet_conn_request() hook to modify the
IPv6 options in just the same way that it already may do for IPv4.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 4663a01..3381748 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -216,14 +216,17 @@ static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req
 	skb = dccp_make_response(sk, dst, req);
 	if (skb != NULL) {
 		struct dccp_hdr *dh = dccp_hdr(skb);
+		struct ipv6_txoptions *opt;
 
 		dh->dccph_checksum = dccp_v6_csum_finish(skb,
 							 &ireq->ir_v6_loc_addr,
 							 &ireq->ir_v6_rmt_addr);
 		fl6.daddr = ireq->ir_v6_rmt_addr;
 		rcu_read_lock();
-		err = ip6_xmit(sk, skb, &fl6, rcu_dereference(np->opt),
-			       np->tclass);
+		opt = ireq->ipv6_opt;
+		if (!opt)
+			opt = rcu_dereference(np->opt);
+		err = ip6_xmit(sk, skb, &fl6, opt, np->tclass);
 		rcu_read_unlock();
 		err = net_xmit_eval(err);
 	}
@@ -236,6 +239,7 @@ done:
 static void dccp_v6_reqsk_destructor(struct request_sock *req)
 {
 	dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
+	kfree(inet_rsk(req)->ipv6_opt);
 	kfree_skb(inet_rsk(req)->pktopts);
 }
 
@@ -494,7 +498,9 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
 	 * Yes, keeping reference count would be much more clever, but we make
 	 * one more one thing there: reattach optmem to newsk.
 	 */
-	opt = rcu_dereference(np->opt);
+	opt = ireq->ipv6_opt;
+	if (!opt)
+		opt = rcu_dereference(np->opt);
 	if (opt) {
 		opt = ipv6_dup_options(newsk, opt);
 		RCU_INIT_POINTER(newnp->opt, opt);