| Message ID | 20190408182206.15688-4-blp@ovn.org |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [ovs-dev,1/5] compiler: Disable BUILD_MESSAGE() when processing with sparse. | expand |
On Mon, Apr 8, 2019 at 11:54 PM Ben Pfaff <blp@ovn.org> wrote: > The assertions make it easier to find all the places that need to be > updated when adding protocol support. > > Signed-off-by: Ben Pfaff <blp@ovn.org> > Acked-by: Numan Siddique <nusiddiq@redhat.com> > --- > lib/flow.c | 64 ++++++++++++++++++++++++++++---------------------- > lib/odp-util.c | 15 ++++++++++-- > 2 files changed, 49 insertions(+), 30 deletions(-) > > diff --git a/lib/flow.c b/lib/flow.c > index 7511b1877ca4..f39b57f5b9d9 100644 > --- a/lib/flow.c > +++ b/lib/flow.c > @@ -626,32 +626,8 @@ parse_nsh(const void **datap, size_t *sizep, struct > ovs_key_nsh *key) > return true; > } > > -/* Initializes 'flow' members from 'packet' and 'md', taking the packet > type > - * into account. > - * > - * Initializes the layer offsets as follows: > - * > - * - packet->l2_5_ofs to the > - * * the start of the MPLS shim header. Can be zero, if the > - * packet is of type (OFPHTN_ETHERTYPE, ETH_TYPE_MPLS). > - * * UINT16_MAX when there is no MPLS shim header. > - * > - * - packet->l3_ofs is set to > - * * zero if the packet_type is in name space OFPHTN_ETHERTYPE > - * and there is no MPLS shim header. > - * * just past the Ethernet header, or just past the vlan_header > if > - * one is present, to the first byte of the payload of the > - * Ethernet frame if the packet type is Ethernet and there is > - * no MPLS shim header. > - * * just past the MPLS label stack to the first byte of the MPLS > - * payload if there is at least one MPLS shim header. > - * * UINT16_MAX if the packet type is Ethernet and the frame is > - * too short to contain an Ethernet header. > - * > - * - packet->l4_ofs is set to just past the IPv4 or IPv6 header, if > one is > - * present and the packet has at least the content used for the > fields > - * of interest for the flow, otherwise UINT16_MAX. > - */ > +/* This does the same thing as miniflow_extract() with a full-size 'flow' > as > + * the destination. */ > void > flow_extract(struct dp_packet *packet, struct flow *flow) > { > @@ -730,11 +706,38 @@ ipv6_sanity_check(const struct ovs_16aligned_ip6_hdr > *nh, size_t size) > return true; > } > > -/* Caller is responsible for initializing 'dst' with enough storage for > - * FLOW_U64S * 8 bytes. */ > +/* Initializes 'dst' from 'packet' and 'md', taking the packet type into > + * account. 'dst' must have enough space for FLOW_U64S * 8 bytes. > + * > + * Initializes the layer offsets as follows: > + * > + * - packet->l2_5_ofs to the > + * * the start of the MPLS shim header. Can be zero, if the > + * packet is of type (OFPHTN_ETHERTYPE, ETH_TYPE_MPLS). > + * * UINT16_MAX when there is no MPLS shim header. > + * > + * - packet->l3_ofs is set to > + * * zero if the packet_type is in name space OFPHTN_ETHERTYPE > + * and there is no MPLS shim header. > + * * just past the Ethernet header, or just past the vlan_header > if > + * one is present, to the first byte of the payload of the > + * Ethernet frame if the packet type is Ethernet and there is > + * no MPLS shim header. > + * * just past the MPLS label stack to the first byte of the MPLS > + * payload if there is at least one MPLS shim header. > + * * UINT16_MAX if the packet type is Ethernet and the frame is > + * too short to contain an Ethernet header. > + * > + * - packet->l4_ofs is set to just past the IPv4 or IPv6 header, if > one is > + * present and the packet has at least the content used for the > fields > + * of interest for the flow, otherwise UINT16_MAX. > + */ > void > miniflow_extract(struct dp_packet *packet, struct miniflow *dst) > { > + /* Add code to this function (or its callees) to extract new fields. > */ > + BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41); > + > const struct pkt_metadata *md = &packet->md; > const void *data = dp_packet_data(packet); > size_t size = dp_packet_size(packet); > @@ -3182,6 +3185,11 @@ void > flow_compose(struct dp_packet *p, const struct flow *flow, > const void *l7, size_t l7_len) > { > + /* Add code to this function (or its callees) for emitting new fields > or > + * protocols. (This isn't essential, so it can be skipped for initial > + * testing.) */ > + BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41); > + > uint32_t pseudo_hdr_csum; > size_t l4_len; > > diff --git a/lib/odp-util.c b/lib/odp-util.c > index b6552c5c208a..6e545b80ba6c 100644 > --- a/lib/odp-util.c > +++ b/lib/odp-util.c > @@ -8230,14 +8230,25 @@ commit_encap_decap_action(const struct flow *flow, > * in addition to this function if needed. Sets fields in 'wc' that are > * used as part of the action. > * > - * Returns a reason to force processing the flow's packets into the > userspace > - * slow path, if there is one, otherwise 0. */ > + * In the common case, this function returns 0. If the flow key > modification > + * requires the flow's packets to be forced into the userspace slow path, > this > + * function returns SLOW_ACTION. This only happens when there is no ODP > action > + * to modify some field that was actually modified. For example, there > is no > + * ODP action to modify any ARP field, so such a modification triggers > + * SLOW_ACTION. (When this happens, packets that need such modification > get > + * flushed to userspace and handled there, which works OK but much more > slowly > + * than if the datapath handled it directly.) */ > enum slow_path_reason > commit_odp_actions(const struct flow *flow, struct flow *base, > struct ofpbuf *odp_actions, struct flow_wildcards *wc, > bool use_masked, bool pending_encap, bool > pending_decap, > struct ofpbuf *encap_data) > { > + /* If you add a field that OpenFlow actions can change, and that is > visible > + * to the datapath (including all data fields), then you should also > add > + * code here to commit changes to the field. */ > + BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41); > + > enum slow_path_reason slow1, slow2; > bool mpls_done = false; > > -- > 2.20.1 > > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev >
diff --git a/lib/flow.c b/lib/flow.c index 7511b1877ca4..f39b57f5b9d9 100644 --- a/lib/flow.c +++ b/lib/flow.c @@ -626,32 +626,8 @@ parse_nsh(const void **datap, size_t *sizep, struct ovs_key_nsh *key) return true; } -/* Initializes 'flow' members from 'packet' and 'md', taking the packet type - * into account. - * - * Initializes the layer offsets as follows: - * - * - packet->l2_5_ofs to the - * * the start of the MPLS shim header. Can be zero, if the - * packet is of type (OFPHTN_ETHERTYPE, ETH_TYPE_MPLS). - * * UINT16_MAX when there is no MPLS shim header. - * - * - packet->l3_ofs is set to - * * zero if the packet_type is in name space OFPHTN_ETHERTYPE - * and there is no MPLS shim header. - * * just past the Ethernet header, or just past the vlan_header if - * one is present, to the first byte of the payload of the - * Ethernet frame if the packet type is Ethernet and there is - * no MPLS shim header. - * * just past the MPLS label stack to the first byte of the MPLS - * payload if there is at least one MPLS shim header. - * * UINT16_MAX if the packet type is Ethernet and the frame is - * too short to contain an Ethernet header. - * - * - packet->l4_ofs is set to just past the IPv4 or IPv6 header, if one is - * present and the packet has at least the content used for the fields - * of interest for the flow, otherwise UINT16_MAX. - */ +/* This does the same thing as miniflow_extract() with a full-size 'flow' as + * the destination. */ void flow_extract(struct dp_packet *packet, struct flow *flow) { @@ -730,11 +706,38 @@ ipv6_sanity_check(const struct ovs_16aligned_ip6_hdr *nh, size_t size) return true; } -/* Caller is responsible for initializing 'dst' with enough storage for - * FLOW_U64S * 8 bytes. */ +/* Initializes 'dst' from 'packet' and 'md', taking the packet type into + * account. 'dst' must have enough space for FLOW_U64S * 8 bytes. + * + * Initializes the layer offsets as follows: + * + * - packet->l2_5_ofs to the + * * the start of the MPLS shim header. Can be zero, if the + * packet is of type (OFPHTN_ETHERTYPE, ETH_TYPE_MPLS). + * * UINT16_MAX when there is no MPLS shim header. + * + * - packet->l3_ofs is set to + * * zero if the packet_type is in name space OFPHTN_ETHERTYPE + * and there is no MPLS shim header. + * * just past the Ethernet header, or just past the vlan_header if + * one is present, to the first byte of the payload of the + * Ethernet frame if the packet type is Ethernet and there is + * no MPLS shim header. + * * just past the MPLS label stack to the first byte of the MPLS + * payload if there is at least one MPLS shim header. + * * UINT16_MAX if the packet type is Ethernet and the frame is + * too short to contain an Ethernet header. + * + * - packet->l4_ofs is set to just past the IPv4 or IPv6 header, if one is + * present and the packet has at least the content used for the fields + * of interest for the flow, otherwise UINT16_MAX. + */ void miniflow_extract(struct dp_packet *packet, struct miniflow *dst) { + /* Add code to this function (or its callees) to extract new fields. */ + BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41); + const struct pkt_metadata *md = &packet->md; const void *data = dp_packet_data(packet); size_t size = dp_packet_size(packet); @@ -3182,6 +3185,11 @@ void flow_compose(struct dp_packet *p, const struct flow *flow, const void *l7, size_t l7_len) { + /* Add code to this function (or its callees) for emitting new fields or + * protocols. (This isn't essential, so it can be skipped for initial + * testing.) */ + BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41); + uint32_t pseudo_hdr_csum; size_t l4_len; diff --git a/lib/odp-util.c b/lib/odp-util.c index b6552c5c208a..6e545b80ba6c 100644 --- a/lib/odp-util.c +++ b/lib/odp-util.c @@ -8230,14 +8230,25 @@ commit_encap_decap_action(const struct flow *flow, * in addition to this function if needed. Sets fields in 'wc' that are * used as part of the action. * - * Returns a reason to force processing the flow's packets into the userspace - * slow path, if there is one, otherwise 0. */ + * In the common case, this function returns 0. If the flow key modification + * requires the flow's packets to be forced into the userspace slow path, this + * function returns SLOW_ACTION. This only happens when there is no ODP action + * to modify some field that was actually modified. For example, there is no + * ODP action to modify any ARP field, so such a modification triggers + * SLOW_ACTION. (When this happens, packets that need such modification get + * flushed to userspace and handled there, which works OK but much more slowly + * than if the datapath handled it directly.) */ enum slow_path_reason commit_odp_actions(const struct flow *flow, struct flow *base, struct ofpbuf *odp_actions, struct flow_wildcards *wc, bool use_masked, bool pending_encap, bool pending_decap, struct ofpbuf *encap_data) { + /* If you add a field that OpenFlow actions can change, and that is visible + * to the datapath (including all data fields), then you should also add + * code here to commit changes to the field. */ + BUILD_ASSERT_DECL(FLOW_WC_SEQ == 41); + enum slow_path_reason slow1, slow2; bool mpls_done = false;
The assertions make it easier to find all the places that need to be updated when adding protocol support. Signed-off-by: Ben Pfaff <blp@ovn.org> --- lib/flow.c | 64 ++++++++++++++++++++++++++++---------------------- lib/odp-util.c | 15 ++++++++++-- 2 files changed, 49 insertions(+), 30 deletions(-)