On 25/02/18 07:44, Roopa Prabhu wrote:
> From: Roopa Prabhu <ro...@cumulusnetworks.com>
>
> Dissect flow in fwd path if fib rules require it. Controlled by
> a flag to avoid penatly for the common case. Flag is set when fib
> rules with sport, dport and proto match that require flow dissect
> are installed. Also passes the dissected hash keys to the multipath
> hash function when applicable to avoid dissecting the flow again.
> icmp packets will continue to use inner header for hash
> calculations.
>
> Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com>
> ---
> include/net/ip6_route.h | 3 ++-
> include/net/netns/ipv6.h | 1 +
> net/ipv6/fib6_rules.c | 5 +++++
> net/ipv6/icmp.c | 2 +-
> net/ipv6/route.c | 45 ++++++++++++++++++++++++++++++++++++---------
> 5 files changed, 45 insertions(+), 11 deletions(-)
>
> diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
> index 27d23a6..218f89c 100644
> --- a/include/net/ip6_route.h
> +++ b/include/net/ip6_route.h
> @@ -127,7 +127,8 @@ static inline int ip6_route_get_saddr(struct net *net,
> struct rt6_info *rt,
>
> struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
> const struct in6_addr *saddr, int oif, int flags);
> -u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb);
> +u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb,
> + struct flow_keys *hkeys);
>
> struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6
> *fl6);
>
> diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
> index 987cc45..7aca00e 100644
> --- a/include/net/netns/ipv6.h
> +++ b/include/net/netns/ipv6.h
> @@ -72,6 +72,7 @@ struct netns_ipv6 {
> unsigned long ip6_rt_last_gc;
> #ifdef CONFIG_IPV6_MULTIPLE_TABLES
> bool fib6_has_custom_rules;
> + bool fib6_rules_require_fldissect;
> struct rt6_info *ip6_prohibit_entry;
> struct rt6_info *ip6_blk_hole_entry;
> struct fib6_table *fib6_local_tbl;
> diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
> index 678d664..e3a7861 100644
> --- a/net/ipv6/fib6_rules.c
> +++ b/net/ipv6/fib6_rules.c
> @@ -267,6 +267,11 @@ static int fib6_rule_configure(struct fib_rule *rule,
> struct sk_buff *skb,
> rule6->dst.plen = frh->dst_len;
> rule6->tclass = frh->tos;
>
> + if (rule->ip_proto ||
> + fib_rule_port_range_valid(&rule->sport_range) ||
> + fib_rule_port_range_valid(&rule->dport_range))
> + net->ipv6.fib6_rules_require_fldissect = true;
> +
> net->ipv6.fib6_has_custom_rules = true;
> err = 0;
> errout:
> diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
> index 4fa4f1b..b0778d3 100644
> --- a/net/ipv6/icmp.c
> +++ b/net/ipv6/icmp.c
> @@ -522,7 +522,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8
> code, __u32 info,
> fl6.fl6_icmp_type = type;
> fl6.fl6_icmp_code = code;
> fl6.flowi6_uid = sock_net_uid(net, NULL);
> - fl6.mp_hash = rt6_multipath_hash(&fl6, skb);
> + fl6.mp_hash = rt6_multipath_hash(&fl6, skb, NULL);
> security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
>
> sk = icmpv6_xmit_lock(net);
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index aa709b6..778212b 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -460,7 +460,7 @@ static struct rt6_info *rt6_multipath_select(struct
> rt6_info *match,
> * case it will always be non-zero. Otherwise now is the time to do it.
> */
> if (!fl6->mp_hash)
> - fl6->mp_hash = rt6_multipath_hash(fl6, NULL);
> + fl6->mp_hash = rt6_multipath_hash(fl6, NULL, NULL);
>
> if (fl6->mp_hash <= atomic_read(&match->rt6i_nh_upper_bound))
> return match;
> @@ -1786,10 +1786,12 @@ struct dst_entry *ip6_route_input_lookup(struct net
> *net,
> EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
>
> static void ip6_multipath_l3_keys(const struct sk_buff *skb,
> - struct flow_keys *keys)
> + struct flow_keys *keys,
> + struct flow_keys *flkeys)
> {
> const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
> const struct ipv6hdr *key_iph = outer_iph;
> + struct flow_keys *_flkeys = flkeys;
> const struct ipv6hdr *inner_iph;
> const struct icmp6hdr *icmph;
> struct ipv6hdr _inner_iph;
> @@ -1811,22 +1813,31 @@ static void ip6_multipath_l3_keys(const struct
> sk_buff *skb,
> goto out;
>
> key_iph = inner_iph;
> + _flkeys = NULL;
> out:
> memset(keys, 0, sizeof(*keys));
> keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
> - keys->addrs.v6addrs.src = key_iph->saddr;
> - keys->addrs.v6addrs.dst = key_iph->daddr;
> - keys->tags.flow_label = ip6_flowinfo(key_iph);
> - keys->basic.ip_proto = key_iph->nexthdr;
> + if (_flkeys) {
> + keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
> + keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
> + keys->tags.flow_label = _flkeys->tags.flow_label;
> + keys->basic.ip_proto = _flkeys->basic.ip_proto;
> + } else {
> + keys->addrs.v6addrs.src = key_iph->saddr;
> + keys->addrs.v6addrs.dst = key_iph->daddr;
> + keys->tags.flow_label = ip6_flowinfo(key_iph);
> + keys->basic.ip_proto = key_iph->nexthdr;
> + }
> }
>
> /* if skb is set it will be used and fl6 can be NULL */
> -u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb)
> +u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb,
> + struct flow_keys *flkeys)
> {
> struct flow_keys hash_keys;
>
> if (skb) {
> - ip6_multipath_l3_keys(skb, &hash_keys);
> + ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
> return flow_hash_from_keys(&hash_keys) >> 1;
> }
>
> @@ -1847,12 +1858,27 @@ void ip6_route_input(struct sk_buff *skb)
> .flowi6_mark = skb->mark,
> .flowi6_proto = iph->nexthdr,
> };
> + struct flow_keys *flkeys = NULL, _flkeys;
>
> tun_info = skb_tunnel_info(skb);
> if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
> fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
> +
> +#ifdef CONFIG_IPV6_MULTIPLE_TABLES
> + if (net->ipv6.fib6_rules_require_fldissect) {
> + unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
> +
> + memset(&_flkeys, 0, sizeof(_flkeys));
Same here, skb_flow_dissect_flow_keys zeroes the flow_keys.
> + skb_flow_dissect_flow_keys(skb, &_flkeys, flag);
> + fl6.fl6_sport = _flkeys.ports.src;
> + fl6.fl6_dport = _flkeys.ports.dst;
> + fl6.flowi6_proto = _flkeys.basic.ip_proto;
> + flkeys = &_flkeys;
> + }
> +#endif
> +
> if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
> - fl6.mp_hash = rt6_multipath_hash(&fl6, skb);
> + fl6.mp_hash = rt6_multipath_hash(&fl6, skb, flkeys);
> skb_dst_drop(skb);
> skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags));
> }
> @@ -4896,6 +4922,7 @@ static int __net_init ip6_route_net_init(struct net
> *net)
>
> #ifdef CONFIG_IPV6_MULTIPLE_TABLES
> net->ipv6.fib6_has_custom_rules = false;
> + net->ipv6.fib6_rules_require_fldissect = false;
> net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
>
> sizeof(*net->ipv6.ip6_prohibit_entry),
> GFP_KERNEL);
>
