flow_dissector: add meaningful comments

Documents two piece of code which can't be understood at a glance.

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Matteo Croce 2019-10-29 14:50:50 +01:00 committed by David S. Miller
parent c4917bfc3a
commit 98298e6ca6
2 changed files with 7 additions and 0 deletions

View File

@ -282,6 +282,7 @@ struct flow_keys {
struct flow_dissector_key_vlan cvlan;
struct flow_dissector_key_keyid keyid;
struct flow_dissector_key_ports ports;
/* 'addrs' must be the last member */
struct flow_dissector_key_addrs addrs;
};

View File

@ -1408,6 +1408,9 @@ static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
{
size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
/* flow.addrs MUST be the last member in struct flow_keys because
* different L3 protocols have different address length
*/
BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
sizeof(*flow) - sizeof(flow->addrs));
@ -1455,6 +1458,9 @@ __be32 flow_get_u32_dst(const struct flow_keys *flow)
}
EXPORT_SYMBOL(flow_get_u32_dst);
/* Sort the source and destination IP (and the ports if the IP are the same),
* to have consistent hash within the two directions
*/
static inline void __flow_hash_consistentify(struct flow_keys *keys)
{
int addr_diff, i;