From eeaea4b537a26d277a17742e38c68ba302caf974 Mon Sep 17 00:00:00 2001 From: Cristian Dumitrescu Date: Sat, 10 Jul 2021 01:20:36 +0100 Subject: [PATCH] examples/pipeline: add selector example Added the files to illustrate the selector table usage. Signed-off-by: Cristian Dumitrescu --- examples/pipeline/examples/selector.cli | 31 ++++++++ examples/pipeline/examples/selector.spec | 95 ++++++++++++++++++++++++ examples/pipeline/examples/selector.txt | 4 + 3 files changed, 130 insertions(+) create mode 100644 examples/pipeline/examples/selector.cli create mode 100644 examples/pipeline/examples/selector.spec create mode 100644 examples/pipeline/examples/selector.txt diff --git a/examples/pipeline/examples/selector.cli b/examples/pipeline/examples/selector.cli new file mode 100644 index 0000000000..36f3ead541 --- /dev/null +++ b/examples/pipeline/examples/selector.cli @@ -0,0 +1,31 @@ +; SPDX-License-Identifier: BSD-3-Clause +; Copyright(c) 2020 Intel Corporation + +mempool MEMPOOL0 buffer 2304 pool 32K cache 256 cpu 0 + +link LINK0 dev 0000:18:00.0 rxq 1 128 MEMPOOL0 txq 1 512 promiscuous on +link LINK1 dev 0000:18:00.1 rxq 1 128 MEMPOOL0 txq 1 512 promiscuous on +link LINK2 dev 0000:3b:00.0 rxq 1 128 MEMPOOL0 txq 1 512 promiscuous on +link LINK3 dev 0000:3b:00.1 rxq 1 128 MEMPOOL0 txq 1 512 promiscuous on + +pipeline PIPELINE0 create 0 + +pipeline PIPELINE0 port in 0 link LINK0 rxq 0 bsz 32 +pipeline PIPELINE0 port in 1 link LINK1 rxq 0 bsz 32 +pipeline PIPELINE0 port in 2 link LINK2 rxq 0 bsz 32 +pipeline PIPELINE0 port in 3 link LINK3 rxq 0 bsz 32 + +pipeline PIPELINE0 port out 0 link LINK0 txq 0 bsz 32 +pipeline PIPELINE0 port out 1 link LINK1 txq 0 bsz 32 +pipeline PIPELINE0 port out 2 link LINK2 txq 0 bsz 32 +pipeline PIPELINE0 port out 3 link LINK3 txq 0 bsz 32 +pipeline PIPELINE0 port out 4 sink none + +pipeline PIPELINE0 build ./examples/pipeline/examples/selector.spec + +pipeline PIPELINE0 selector s group add +pipeline PIPELINE0 selector s group member add ./examples/pipeline/examples/selector.txt +pipeline PIPELINE0 commit +pipeline PIPELINE0 selector s show + +thread 1 pipeline PIPELINE0 enable diff --git a/examples/pipeline/examples/selector.spec b/examples/pipeline/examples/selector.spec new file mode 100644 index 0000000000..72e49cb1d8 --- /dev/null +++ b/examples/pipeline/examples/selector.spec @@ -0,0 +1,95 @@ +; SPDX-License-Identifier: BSD-3-Clause +; Copyright(c) 2020 Intel Corporation + +; A selector table is made out of groups of weighted members, with a given member potentially part +; of several groups. The select operation returns a member ID by first selecting a group based on an +; input group ID and then selecting a member within that group by hashing one or several input +; header or meta-data fields. It is very useful for implementing an Equal-Cost Multi-Path (ECMP) or +; Weighted-Cost Multi-Path (WCMP) enabled FIB or a load balancer. It is part of the action selector +; construct described by the P4 Portable Switch Architecture (PSA) specification. +; +; Normally, an action selector FIB is built with a routing table (the base table), a selector table +; (the group table) and a next hop table (the member table). One of the routing table actions sets +; up the group ID meta-data field used as the index into the group table, which produces the member +; ID meta-data field, i.e. the next hop ID that is used as the index into the next hop table. The +; next hop action prepares the output packet for being sent next hop in the network by prepending +; one or several headers to the packet (Ethernet at the very least), decrementing the TTL and +; recomputing the IPv4 checksum, etc. The selector allows for multiple next hops to be specified +; for any given route as opposed to a single next hop per route; for every packet, its next hop is +; picked out of the set of next hops defined for the route while preserving the packet ordering +; within the flow, with the flow defined by the selector n-tuple fields. +; +; In this simple example, the base table and the member table are striped out in order to focus +; exclusively on illustrating the selector table. The group_id is read from the destination MAC +; address and the selector n-tuple is represented by the Protocol, the source IP address and the +; destination IP address fields. The member_id produced by the selector table is used to identify +; the output port which facilitates the testing of different member weights by simply comparing the +; rates of output packets sent on different ports. + +// +// Headers +// +struct ethernet_h { + bit<48> dst_addr + bit<48> src_addr + bit<16> ethertype +} + +struct ipv4_h { + bit<8> ver_ihl + bit<8> diffserv + bit<16> total_len + bit<16> identification + bit<16> flags_offset + bit<8> ttl + bit<8> protocol + bit<16> hdr_checksum + bit<32> src_addr + bit<32> dst_addr +} + +header ethernet instanceof ethernet_h +header ipv4 instanceof ipv4_h + +// +// Meta-data +// +struct metadata_t { + bit<32> port_in + bit<32> port_out + bit<32> group_id +} + +metadata instanceof metadata_t + +// +// Selectors. +// +selector s { + group_id m.group_id + + selector { + h.ipv4.protocol + h.ipv4.src_addr + h.ipv4.dst_addr + } + + member_id m.port_out + + n_groups_max 64 + n_members_per_group_max 16 +} + +// +// Pipeline. +// +apply { + rx m.port_in + extract h.ethernet + extract h.ipv4 + mov m.group_id h.ethernet.dst_addr + table s + emit h.ethernet + emit h.ipv4 + tx m.port_out +} diff --git a/examples/pipeline/examples/selector.txt b/examples/pipeline/examples/selector.txt new file mode 100644 index 0000000000..b3c83c7738 --- /dev/null +++ b/examples/pipeline/examples/selector.txt @@ -0,0 +1,4 @@ +group 0 member 0 weight 1 +group 0 member 1 weight 1 +group 0 member 2 weight 2 +group 0 member 3 weight 4 -- 2.20.1