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/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 711d209f9124..18daddc6001c 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -443,6 +443,7 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 {
         struct inet_request_sock *ireq = inet_rsk(req);
         struct ipv6_pinfo *np = inet6_sk(sk);
+        struct ipv6_txoptions *opt;
         struct flowi6 *fl6 = &fl->u.ip6;
         struct sk_buff *skb;
         int err = -ENOMEM;
@@ -463,8 +464,10 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 
                 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);
         }
@@ -476,6 +479,7 @@ done:
 
 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 {
+        kfree(inet_rsk(req)->ipv6_opt);
         kfree_skb(inet_rsk(req)->pktopts);
 }
 
@@ -1107,7 +1111,9 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
            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);