From a346abe051bd2bd0d5d0140b2da9ec95639acad7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 1 Jul 2019 06:39:36 -0700 Subject: ipv6: icmp: allow flowlabel reflection in echo replies Extend flowlabel_reflect bitmask to allow conditional reflection of incoming flowlabels in echo replies. Note this has precedence against auto flowlabels. Add flowlabel_reflect enum to replace hard coded values. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 4 +++- include/net/ipv6.h | 7 +++++++ net/ipv6/af_inet6.c | 2 +- net/ipv6/icmp.c | 3 +++ net/ipv6/sysctl_net_ipv6.c | 4 ++-- net/ipv6/tcp_ipv6.c | 2 +- 6 files changed, 17 insertions(+), 5 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index e0d8a96e2c67..f0e6d1f53485 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1452,7 +1452,7 @@ flowlabel_reflect - INTEGER environments. See RFC 7690 and: https://tools.ietf.org/html/draft-wang-6man-flow-label-reflection-01 - This is a mask of two bits. + This is a bitmask. 1: enabled for established flows Note that this prevents automatic flowlabel changes, as done @@ -1463,6 +1463,8 @@ flowlabel_reflect - INTEGER If set, a RST packet sent in response to a SYN packet on a closed port will reflect the incoming flow label. + 4: enabled for ICMPv6 echo reply messages. + Default: 0 fib_multipath_hash_policy - INTEGER diff --git a/include/net/ipv6.h b/include/net/ipv6.h index b41f6a0fa903..8eca5fb30376 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -301,6 +301,13 @@ struct ipv6_txoptions { /* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */ }; +/* flowlabel_reflect sysctl values */ +enum flowlabel_reflect { + FLOWLABEL_REFLECT_ESTABLISHED = 1, + FLOWLABEL_REFLECT_TCP_RESET = 2, + FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES = 4, +}; + struct ip6_flowlabel { struct ip6_flowlabel __rcu *next; __be32 label; diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 7382a927d1eb..8369af32cef6 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -208,7 +208,7 @@ lookup_protocol: np->mc_loop = 1; np->mc_all = 1; np->pmtudisc = IPV6_PMTUDISC_WANT; - np->repflow = net->ipv6.sysctl.flowlabel_reflect & 1; + np->repflow = net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ESTABLISHED; sk->sk_ipv6only = net->ipv6.sysctl.bindv6only; /* Init the ipv4 part of the socket since we can have sockets diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 12906301ec7b..62c997201970 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -703,6 +703,9 @@ static void icmpv6_echo_reply(struct sk_buff *skb) tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; memset(&fl6, 0, sizeof(fl6)); + if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES) + fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb)); + fl6.flowi6_proto = IPPROTO_ICMPV6; fl6.daddr = ipv6_hdr(skb)->saddr; if (saddr) diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index 6d86fac472e7..8b3fe81783ed 100644 --- a/net/ipv6/sysctl_net_ipv6.c +++ b/net/ipv6/sysctl_net_ipv6.c @@ -23,7 +23,7 @@ static int zero; static int one = 1; -static int three = 3; +static int flowlabel_reflect_max = 0x7; static int auto_flowlabels_min; static int auto_flowlabels_max = IP6_AUTO_FLOW_LABEL_MAX; @@ -116,7 +116,7 @@ static struct ctl_table ipv6_table_template[] = { .mode = 0644, .proc_handler = proc_dointvec, .extra1 = &zero, - .extra2 = &three, + .extra2 = &flowlabel_reflect_max, }, { .procname = "max_dst_opts_number", diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 408d9ec26971..4f3f99b39820 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -989,7 +989,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) if (sk->sk_state == TCP_TIME_WAIT) label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel); } else { - if (net->ipv6.sysctl.flowlabel_reflect & 2) + if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET) label = ip6_flowlabel(ipv6h); } -- cgit v1.2.3-59-g8ed1b