summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMatteo Croce <mcroce@redhat.com>2019-10-29 16:50:50 +0300
committerDavid S. Miller <davem@davemloft.net>2019-10-31 03:21:35 +0300
commit98298e6ca6d5908f96e529e70a254a4d5bf754e7 (patch)
tree6ac75b9530965e78a7bc6ae19c038de6f8722325
parentc4917bfc3a6f768508e820c10294149de259fa74 (diff)
downloadlinux-98298e6ca6d5908f96e529e70a254a4d5bf754e7.tar.xz
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>
-rw-r--r--include/net/flow_dissector.h1
-rw-r--r--net/core/flow_dissector.c6
2 files changed, 7 insertions, 0 deletions
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index 90bd210be060..7747af3cc500 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -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;
};
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index dbf502c18656..bc22b384ac6c 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -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;