| Message ID | 1388656263-6795-1-git-send-email-fx.lebail@yahoo.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
Hello. On 02-01-2014 13:51, Francois-Xavier Le Bail wrote: > This change allows to follow a recommandation of RFC4942. > - Add "enable_anycast_src" sysctl to control the use of Subnet-Router anycast > addresses as source addresses. This sysctl is false by default to preserve > existing behavior. > - Use it in ip6_datagram_send_ctl() and icmpv6_echo_reply(). > Reference: > RFC4942 - IPv6 Transition/Coexistence Security Considerations > (http://tools.ietf.org/html/rfc4942#section-2.1.6) > 2.1.6. Anycast Traffic Identification and Security > > [...] > To avoid exposing knowledge about the internal structure of the > network, it is recommended that anycast servers now take advantage of > the ability to return responses with the anycast address as the > source address if possible. > Signed-off-by: Francois-Xavier Le Bail <fx.lebail@yahoo.com> > --- [...] > diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c > index 6983058..c7d6392 100644 > --- a/net/ipv6/datagram.c > +++ b/net/ipv6/datagram.c > @@ -668,6 +668,9 @@ int ip6_datagram_send_ctl(struct net *net, struct sock *sk, > if (addr_type != IPV6_ADDR_ANY) { > int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL; > if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) && > + !(net->ipv6.enable_anycast_src && > + ipv6_chk_acast_addr(net, NULL, > + &src_info->ipi6_addr)) && The continuation line should start right under 'net' on the previous line. WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
-------------------------------------------- On Thu, 1/2/14, Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> wrote: > Hello. Hello, >> + !(net->ipv6.enable_anycast_src && >> + ipv6_chk_acast_addr(net, NULL, >> + &src_info->ipi6_addr)) && > The continuation line should start right under 'net' on the previous line. > WBR, Sergei Thanks, I will make the change in patch version 2. BR, Francois-Xavier -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index d71afa8..2a062a7 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1094,6 +1094,12 @@ bindv6only - BOOLEAN Default: FALSE (as specified in RFC3493) +enable_anycast_src - BOOLEAN + Controls the use of Subnet-Router anycast addresses as source addresses + TRUE: enabled + FALSE: disabled + Default: FALSE + IPv6 Fragmentation: ip6frag_high_thresh - INTEGER diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index 0fb2401..3d3aa86 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -73,6 +73,7 @@ struct netns_ipv6 { #endif atomic_t dev_addr_genid; atomic_t rt_genid; + int enable_anycast_src; }; #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c index 6983058..c7d6392 100644 --- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -668,6 +668,9 @@ int ip6_datagram_send_ctl(struct net *net, struct sock *sk, if (addr_type != IPV6_ADDR_ANY) { int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL; if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) && + !(net->ipv6.enable_anycast_src && + ipv6_chk_acast_addr(net, NULL, + &src_info->ipi6_addr)) && !ipv6_chk_addr(net, &src_info->ipi6_addr, strict ? dev : NULL, 0)) err = -EINVAL; diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index eef8d94..4adcd25 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -554,7 +554,9 @@ static void icmpv6_echo_reply(struct sk_buff *skb) saddr = &ipv6_hdr(skb)->daddr; - if (!ipv6_unicast_destination(skb)) + if (!ipv6_unicast_destination(skb) && + !(net->ipv6.enable_anycast_src && + ipv6_chk_acast_addr(net, NULL, saddr))) saddr = NULL; memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index 107b2f1..67c09f5 100644 --- a/net/ipv6/sysctl_net_ipv6.c +++ b/net/ipv6/sysctl_net_ipv6.c @@ -24,6 +24,13 @@ static struct ctl_table ipv6_table_template[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "enable_anycast_src", + .data = &init_net.ipv6.enable_anycast_src, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, { } }; @@ -51,6 +58,7 @@ static int __net_init ipv6_sysctl_net_init(struct net *net) if (!ipv6_table) goto out; ipv6_table[0].data = &net->ipv6.sysctl.bindv6only; + ipv6_table[1].data = &net->ipv6.enable_anycast_src; ipv6_route_table = ipv6_route_sysctl_init(net); if (!ipv6_route_table)
This change allows to follow a recommandation of RFC4942. - Add "enable_anycast_src" sysctl to control the use of Subnet-Router anycast addresses as source addresses. This sysctl is false by default to preserve existing behavior. - Use it in ip6_datagram_send_ctl() and icmpv6_echo_reply(). Reference: RFC4942 - IPv6 Transition/Coexistence Security Considerations (http://tools.ietf.org/html/rfc4942#section-2.1.6) 2.1.6. Anycast Traffic Identification and Security [...] To avoid exposing knowledge about the internal structure of the network, it is recommended that anycast servers now take advantage of the ability to return responses with the anycast address as the source address if possible. Signed-off-by: Francois-Xavier Le Bail <fx.lebail@yahoo.com> --- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html