On Sat, 2018-02-24 at 21:44 -0800, 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 (Thanks to Nikolay Aleksandrov for some review here).
>
> Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com>
> ---
> include/net/ip_fib.h | 2 +-
> include/net/netns/ipv4.h | 1 +
> net/ipv4/fib_rules.c | 6 ++++++
> net/ipv4/fib_semantics.c | 2 +-
> net/ipv4/route.c | 52
> +++++++++++++++++++++++++++++++++++-------------
> 5 files changed, 47 insertions(+), 16 deletions(-)
>
> diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
> index f805243..5ada772 100644
> --- a/include/net/ip_fib.h
> +++ b/include/net/ip_fib.h
> @@ -371,7 +371,7 @@ int fib_sync_up(struct net_device *dev, unsigned int
> nh_flags);
>
> #ifdef CONFIG_IP_ROUTE_MULTIPATH
> int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
> - const struct sk_buff *skb);
> + const struct sk_buff *skb, struct flow_keys *flkeys);
> #endif
> void fib_select_multipath(struct fib_result *res, int hash);
> void fib_select_path(struct net *net, struct fib_result *res,
> diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
> index 44668c2..87b8fdc 100644
> --- a/include/net/netns/ipv4.h
> +++ b/include/net/netns/ipv4.h
> @@ -52,6 +52,7 @@ struct netns_ipv4 {
> #ifdef CONFIG_IP_MULTIPLE_TABLES
> struct fib_rules_ops *rules_ops;
> bool fib_has_custom_rules;
> + bool fib_rules_require_fldissect;
> struct fib_table __rcu *fib_main;
> struct fib_table __rcu *fib_default;
> #endif
> diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
> index 9d55c90..83aa786 100644
> --- a/net/ipv4/fib_rules.c
> +++ b/net/ipv4/fib_rules.c
> @@ -253,6 +253,11 @@ static int fib4_rule_configure(struct fib_rule *rule,
> struct sk_buff *skb,
> }
> #endif
>
> + if (rule->ip_proto ||
> + fib_rule_port_range_valid(&rule->sport_range) ||
> + fib_rule_port_range_valid(&rule->dport_range))
> + net->ipv4.fib_rules_require_fldissect = true;
> +
> rule4->src_len = frh->src_len;
> rule4->srcmask = inet_make_mask(rule4->src_len);
> rule4->dst_len = frh->dst_len;
What about using 'fib_rules_require_fldissect' to conditionally avoid
all the tests introduced by patch 2/5 ? Perhaps even using a static key
for that?
It would be great if the kernel would be able to clear this flag when
no more needed. I know it's not the current behaviour for other similar
flags, but I hope we can improve ;)
Both points above also apply to the ipv6 code path.
Thanks,
Paolo
