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[109.115.41.234]) by smtp.gmail.com with ESMTPSA id l18sm20701933wrn.48.2019.10.21.13.10.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Oct 2019 13:10:25 -0700 (PDT) From: Matteo Croce To: netdev@vger.kernel.org Cc: Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , "David S . Miller " , Stanislav Fomichev , Daniel Borkmann , Song Liu , Alexei Starovoitov , Paul Blakey , linux-kernel@vger.kernel.org Subject: [PATCH net-next 1/4] flow_dissector: add meaningful comments Date: Mon, 21 Oct 2019 22:09:45 +0200 Message-Id: <20191021200948.23775-2-mcroce@redhat.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20191021200948.23775-1-mcroce@redhat.com> References: <20191021200948.23775-1-mcroce@redhat.com> MIME-Version: 1.0 X-MC-Unique: xNJjvuIxMJK-74RHC9vx2w-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Documents two piece of code which can't be understood at a glance. Signed-off-by: Matteo Croce --- include/net/flow_dissector.h | 1 + net/core/flow_dissector.c | 6 ++++++ 2 files changed, 7 insertions(+) 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 { =09struct flow_dissector_key_vlan cvlan; =09struct flow_dissector_key_keyid keyid; =09struct flow_dissector_key_ports ports; +=09/* 'addrs' must be the last member */ =09struct flow_dissector_key_addrs addrs; }; =20 diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 7c09d87d3269..affde70dad47 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -1374,6 +1374,9 @@ static inline size_t flow_keys_hash_length(const stru= ct flow_keys *flow) { =09size_t diff =3D FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); =09BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32)); +=09/* flow.addrs MUST be the last member in struct flow_keys because +=09 * different L3 protocols have different address length +=09 */ =09BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=3D =09=09 sizeof(*flow) - sizeof(flow->addrs)); =20 @@ -1421,6 +1424,9 @@ __be32 flow_get_u32_dst(const struct flow_keys *flow) } EXPORT_SYMBOL(flow_get_u32_dst); =20 +/* Sort the source and destination IP (and the ports if the IP are the sam= e), + * to have consistent hash within the two directions + */ static inline void __flow_hash_consistentify(struct flow_keys *keys) { =09int addr_diff, i; --=20 2.21.0