@@ -191,6 +191,7 @@ struct ipv6_pinfo {
/* sockopt flags */
__u16 recverr:1,
sndflow:1,
+ repflow:1,
pmtudisc:3,
ipv6only:1,
srcprefs:3, /* 001: prefer temporary address
@@ -85,6 +85,7 @@ struct in6_flowlabel_req {
#define IPV6_FL_F_CREATE 1
#define IPV6_FL_F_EXCL 2
+#define IPV6_FL_F_REFLECT 4
#define IPV6_FL_S_NONE 0
#define IPV6_FL_S_EXCL 1
@@ -486,6 +486,11 @@ int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq)
struct ipv6_pinfo *np = inet6_sk(sk);
struct ipv6_fl_socklist *sfl;
+ if (np->repflow) {
+ freq->flr_label = np->flow_label;
+ return 0;
+ }
+
rcu_read_lock_bh();
for_each_sk_fl_rcu(np, sfl) {
@@ -527,6 +532,15 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
switch (freq.flr_action) {
case IPV6_FL_A_PUT:
+ if (freq.flr_flags & IPV6_FL_F_REFLECT) {
+ if (sk->sk_protocol != IPPROTO_TCP)
+ return -ENOPROTOOPT;
+ if (!np->repflow)
+ return -ESRCH;
+ np->flow_label = 0;
+ np->repflow = 0;
+ return 0;
+ }
spin_lock_bh(&ip6_sk_fl_lock);
for (sflp = &np->ipv6_fl_list;
(sfl = rcu_dereference(*sflp))!=NULL;
@@ -567,6 +581,13 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
return -ESRCH;
case IPV6_FL_A_GET:
+ if (freq.flr_flags & IPV6_FL_F_REFLECT) {
+ if (sk->sk_protocol != IPPROTO_TCP)
+ return -ENOPROTOOPT;
+ np->repflow = 1;
+ return 0;
+ }
+
if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
return -EINVAL;
@@ -483,6 +483,8 @@ static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
&ireq->ir_v6_rmt_addr);
fl6->daddr = ireq->ir_v6_rmt_addr;
+ if (np->repflow)
+ fl6->flowlabel = np->flow_label;
skb_set_queue_mapping(skb, queue_mapping);
err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
err = net_xmit_eval(err);
@@ -1000,6 +1002,8 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
ireq = inet_rsk(req);
ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
+ if (np->repflow)
+ np->flow_label = ip6_flowlabel(ipv6_hdr(skb));
if (!want_cookie || tmp_opt.tstamp_ok)
TCP_ECN_create_request(req, skb, sock_net(sk));
@@ -1138,6 +1142,8 @@ static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
+ if (np->repflow)
+ newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
/*
* No need to charge this sock to the relevant IPv6 refcnt debug socks count
@@ -1218,6 +1224,8 @@ static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
+ if (np->repflow)
+ newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
/* Clone native IPv6 options from listening socket (if any)
@@ -1429,6 +1437,8 @@ ipv6_pktoptions:
np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
+ if (np->repflow)
+ np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
if (ipv6_opt_accepted(sk, opt_skb)) {
skb_set_owner_r(opt_skb, sk);
opt_skb = xchg(&np->pktoptions, opt_skb);
With this option, the socket will reply with the flow label value read on received packets. The goal is to have a connection with the same flow label in both direction of the communication. Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr> --- include/linux/ipv6.h | 1 + include/uapi/linux/in6.h | 1 + net/ipv6/ip6_flowlabel.c | 21 +++++++++++++++++++++ net/ipv6/tcp_ipv6.c | 10 ++++++++++ 4 files changed, 33 insertions(+)