diff options
author | Jiri Pirko <jiri@resnulli.us> | 2015-05-12 14:56:15 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2015-05-13 15:19:47 -0400 |
commit | fbff949e3bc7f3f7d9e8b3ef4855ec7138276a25 (patch) | |
tree | ad9107461ea0fe95a5032d0ff6f9ec18755aaf32 /net | |
parent | 0db89b8b3243829704225e756ca7417e06812bba (diff) | |
download | linux-fbff949e3bc7f3f7d9e8b3ef4855ec7138276a25.tar.bz2 |
flow_dissector: introduce programable flow_dissector
Introduce dissector infrastructure which allows user to specify which
parts of skb he wants to dissect.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/core/flow_dissector.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index d885e282908e..6883e22b8fc4 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -1,3 +1,4 @@ +#include <linux/kernel.h> #include <linux/skbuff.h> #include <linux/export.h> #include <linux/ip.h> @@ -15,6 +16,53 @@ #include <net/flow_dissector.h> #include <scsi/fc/fc_fcoe.h> +static bool skb_flow_dissector_uses_key(struct flow_dissector *flow_dissector, + enum flow_dissector_key_id key_id) +{ + return flow_dissector->used_keys & (1 << key_id); +} + +static void skb_flow_dissector_set_key(struct flow_dissector *flow_dissector, + enum flow_dissector_key_id key_id) +{ + flow_dissector->used_keys |= (1 << key_id); +} + +static void *skb_flow_dissector_target(struct flow_dissector *flow_dissector, + enum flow_dissector_key_id key_id, + void *target_container) +{ + return ((char *) target_container) + flow_dissector->offset[key_id]; +} + +void skb_flow_dissector_init(struct flow_dissector *flow_dissector, + const struct flow_dissector_key *key, + unsigned int key_count) +{ + unsigned int i; + + memset(flow_dissector, 0, sizeof(*flow_dissector)); + + for (i = 0; i < key_count; i++, key++) { + /* User should make sure that every key target offset is withing + * boundaries of unsigned short. + */ + BUG_ON(key->offset > USHRT_MAX); + BUG_ON(skb_flow_dissector_uses_key(flow_dissector, + key->key_id)); + + skb_flow_dissector_set_key(flow_dissector, key->key_id); + flow_dissector->offset[key->key_id] = key->offset; + } + + /* Ensure that the dissector always includes basic key. That way + * we are able to avoid handling lack of it in fast path. + */ + BUG_ON(!skb_flow_dissector_uses_key(flow_dissector, + FLOW_DISSECTOR_KEY_BASIC)); +} +EXPORT_SYMBOL(skb_flow_dissector_init); + /* copy saddr & daddr, possibly using 64bit load/store * Equivalent to : flow->src = iph->saddr; * flow->dst = iph->daddr; |