diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 9375324aa8e1..5cdc37c34830 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1560,6 +1560,18 @@ skip_notify_on_dev_down - BOOLEAN on userspace caches to track link events and evict routes. Default: false (generate message) +nexthop_compat_mode - BOOLEAN + New nexthop API provides a means for managing nexthops independent of + prefixes. Backwards compatibilty with old route format is enabled by + default which means route dumps and notifications contain the new + nexthop attribute but also the full, expanded nexthop definition. + Further, updates or deletes of a nexthop configuration generate route + notifications for each fib entry using the nexthop. Once a system + understands the new API, this sysctl can be disabled to achieve full + performance benefits of the new API by disabling the nexthop expansion + and extraneous notifications. + Default: true (backward compat mode) + IPv6 Fragmentation: ip6frag_high_thresh - INTEGER diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 154b8f01499b..5acdb4d414c4 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -111,6 +111,8 @@ struct netns_ipv4 { int sysctl_tcp_early_demux; int sysctl_udp_early_demux; + int sysctl_nexthop_compat_mode; + int sysctl_fwmark_reflect; int sysctl_tcp_fwmark_accept; #ifdef CONFIG_NET_L3_MASTER_DEV diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index c618e242490f..6177c4ba0037 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1835,6 +1835,7 @@ static __net_init int inet_init_net(struct net *net) net->ipv4.sysctl_ip_early_demux = 1; net->ipv4.sysctl_udp_early_demux = 1; net->ipv4.sysctl_tcp_early_demux = 1; + net->ipv4.sysctl_nexthop_compat_mode = 1; #ifdef CONFIG_SYSCTL net->ipv4.sysctl_ip_prot_sock = PROT_SOCK; #endif diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 55ca2e521828..e53871e4a097 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -1780,6 +1780,8 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, goto nla_put_failure; if (nexthop_is_blackhole(fi->nh)) rtm->rtm_type = RTN_BLACKHOLE; + if (!fi->fib_net->ipv4.sysctl_nexthop_compat_mode) + goto offload; } if (nhs == 1) { @@ -1805,6 +1807,7 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, goto nla_put_failure; } +offload: if (fri->offload) rtm->rtm_flags |= RTM_F_OFFLOAD; if (fri->trap) diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c index 9999687ad6dc..3957364d556c 100644 --- a/net/ipv4/nexthop.c +++ b/net/ipv4/nexthop.c @@ -784,7 +784,8 @@ static void __remove_nexthop_fib(struct net *net, struct nexthop *nh) list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) { /* __ip6_del_rt does a release, so do a hold here */ fib6_info_hold(f6i); - ipv6_stub->ip6_del_rt(net, f6i, false); + ipv6_stub->ip6_del_rt(net, f6i, + !net->ipv4.sysctl_nexthop_compat_mode); } } @@ -1041,7 +1042,7 @@ out: if (!rc) { nh_base_seq_inc(net); nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo); - if (replace_notify) + if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode) nexthop_replace_notify(net, new_nh, &cfg->nlinfo); } diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 81b267e990a1..95ad71e76cc3 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -710,6 +710,15 @@ static struct ctl_table ipv4_net_table[] = { .mode = 0644, .proc_handler = proc_tcp_early_demux }, + { + .procname = "nexthop_compat_mode", + .data = &init_net.ipv4.sysctl_nexthop_compat_mode, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, { .procname = "ip_default_ttl", .data = &init_net.ipv4.sysctl_ip_default_ttl, diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 486c36a14f24..803212aae4ca 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5557,7 +5557,8 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb, if (nexthop_is_blackhole(rt->nh)) rtm->rtm_type = RTN_BLACKHOLE; - if (rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0) + if (net->ipv4.sysctl_nexthop_compat_mode && + rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0) goto nla_put_failure; rtm->rtm_flags |= nh_flags;