From df3687ffc6653e4d32168338b4dee20c164ed7c9 Mon Sep 17 00:00:00 2001 From: Florent Fourcot Date: Fri, 17 Jan 2014 17:15:03 +0100 Subject: [PATCH] ipv6: add the IPV6_FL_F_REFLECT flag to IPV6_FL_A_GET 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. Changelog of V4: * Do not erase the flow label on the listening socket. Use pktopts to store the received value Signed-off-by: Florent Fourcot Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- include/linux/ipv6.h | 1 + include/uapi/linux/in6.h | 1 + net/ipv6/ip6_flowlabel.c | 21 +++++++++++++++++++++ net/ipv6/tcp_ipv6.c | 12 +++++++++++- 4 files changed, 34 insertions(+), 1 deletion(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 7e1ded0d8e45..1084304fd75a 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -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 diff --git a/include/uapi/linux/in6.h b/include/uapi/linux/in6.h index f94f1d013bf2..02c0cd685a27 100644 --- a/include/uapi/linux/in6.h +++ b/include/uapi/linux/in6.h @@ -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 diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c index cbc93517b455..55823f187446 100644 --- a/net/ipv6/ip6_flowlabel.c +++ b/net/ipv6/ip6_flowlabel.c @@ -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; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index b5512696e9ed..b61fa8bac3bd 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -483,6 +483,9 @@ 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 && (ireq->pktopts != NULL)) + fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); + skb_set_queue_mapping(skb, queue_mapping); err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass); err = net_xmit_eval(err); @@ -1018,7 +1021,8 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) if (!isn) { if (ipv6_opt_accepted(sk, skb) || np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || - np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { + np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim || + np->repflow) { atomic_inc(&skb->users); ireq->pktopts = skb; } @@ -1143,6 +1147,8 @@ 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 @@ -1223,6 +1229,8 @@ 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) @@ -1434,6 +1442,8 @@ 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); -- 2.20.1