From 6444f72b4b74f627c51891101e93ba2b94078b0a Mon Sep 17 00:00:00 2001 From: Florent Fourcot Date: Fri, 17 Jan 2014 17:15:05 +0100 Subject: [PATCH] ipv6: add flowlabel_consistency sysctl With the introduction of IPV6_FL_F_REFLECT, there is no guarantee of flow label unicity. This patch introduces a new sysctl to protect the old behaviour, enable by default. Changelog of V3: * rename ip6_flowlabel_consistency to flowlabel_consistency * use net_info_ratelimited() * checkpatch cleanups Signed-off-by: Florent Fourcot Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 8 ++++++++ include/net/netns/ipv6.h | 1 + net/ipv6/af_inet6.c | 1 + net/ipv6/ip6_flowlabel.c | 7 +++++++ net/ipv6/sysctl_net_ipv6.c | 8 ++++++++ 5 files changed, 25 insertions(+) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index c97932c88ea3..5de03740cdd5 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1118,6 +1118,14 @@ bindv6only - BOOLEAN Default: FALSE (as specified in RFC3493) +flowlabel_consistency - BOOLEAN + Protect the consistency (and unicity) of flow label. + You have to disable it to use IPV6_FL_F_REFLECT flag on the + flow label manager. + TRUE: enabled + FALSE: disabled + Default: TRUE + anycast_src_echo_reply - BOOLEAN Controls the use of anycast addresses as source addresses for ICMPv6 echo reply diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index 592fecd2e59e..21edaf1f7916 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -27,6 +27,7 @@ struct netns_sysctl_ipv6 { int ip6_rt_gc_elasticity; int ip6_rt_mtu_expires; int ip6_rt_min_advmss; + int flowlabel_consistency; int icmpv6_time; int anycast_src_echo_reply; }; diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index c921d5d38831..d935889f1008 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -775,6 +775,7 @@ static int __net_init inet6_net_init(struct net *net) net->ipv6.sysctl.bindv6only = 0; net->ipv6.sysctl.icmpv6_time = 1*HZ; + net->ipv6.sysctl.flowlabel_consistency = 1; atomic_set(&net->ipv6.rt_genid, 0); err = ipv6_init_mibs(net); diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c index 01bf2524c72a..dfa41bb4e0dc 100644 --- a/net/ipv6/ip6_flowlabel.c +++ b/net/ipv6/ip6_flowlabel.c @@ -588,8 +588,15 @@ int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen) case IPV6_FL_A_GET: if (freq.flr_flags & IPV6_FL_F_REFLECT) { + struct net *net = sock_net(sk); + if (net->ipv6.sysctl.flowlabel_consistency) { + net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n"); + return -EPERM; + } + if (sk->sk_protocol != IPPROTO_TCP) return -ENOPROTOOPT; + np->repflow = 1; return 0; } diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index b51b2688102c..7f405a168822 100644 --- a/net/ipv6/sysctl_net_ipv6.c +++ b/net/ipv6/sysctl_net_ipv6.c @@ -31,6 +31,13 @@ static struct ctl_table ipv6_table_template[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "flowlabel_consistency", + .data = &init_net.ipv6.sysctl.flowlabel_consistency, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, { } }; @@ -59,6 +66,7 @@ static int __net_init ipv6_sysctl_net_init(struct net *net) goto out; ipv6_table[0].data = &net->ipv6.sysctl.bindv6only; ipv6_table[1].data = &net->ipv6.sysctl.anycast_src_echo_reply; + ipv6_table[2].data = &net->ipv6.sysctl.flowlabel_consistency; ipv6_route_table = ipv6_route_sysctl_init(net); if (!ipv6_route_table) -- 2.20.1