net/tap: add eBPF program file
File tap_bpf_program.c was added with two ELF sections corresponding to two BPF programs and one BPF map. Section cls_q - BPF classifier to classify packets to their corresponding queue after an RSS hash was calculated on the packet and saved in skb->cb[1] Section l3_l4 - BPF action to calculate RSS hash on packet layers 3 and 4 This file is not part of DPDK tree compilation. Signed-off-by: Ophir Munk <ophirmu@mellanox.com> Acked-by: Pascal Mazon <pascal.mazon@6wind.com>
This commit is contained in:
Ophir Munk
Ferruh Yigit
parent
fb847dcf73
commit
cdc07e83bb
221
drivers/net/tap/tap_bpf_program.c
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221
drivers/net/tap/tap_bpf_program.c
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/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
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* Copyright 2017 Mellanox Technologies, Ltd.
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*/
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#include <stdint.h>
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#include <stdbool.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <asm/types.h>
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#include <linux/in.h>
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#include <linux/if.h>
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#include <linux/if_ether.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/if_tunnel.h>
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#include <linux/filter.h>
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#include <linux/bpf.h>
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#include "tap_rss.h"
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/** Create IPv4 address */
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#define IPv4(a, b, c, d) ((__u32)(((a) & 0xff) << 24) | \
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(((b) & 0xff) << 16) | \
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(((c) & 0xff) << 8) | \
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((d) & 0xff))
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#define PORT(a, b) ((__u16)(((a) & 0xff) << 8) | \
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((b) & 0xff))
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/*
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* The queue number is offset by 1, to distinguish packets that have
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* gone through this rule (skb->cb[1] != 0) from others.
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*/
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#define QUEUE_OFFSET 1
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#define PIN_GLOBAL_NS 2
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#define KEY_IDX 0
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#define BPF_MAP_ID_KEY 1
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struct vlan_hdr {
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__be16 proto;
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__be16 tci;
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};
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struct bpf_elf_map __attribute__((section("maps"), used))
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map_keys = {
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.type = BPF_MAP_TYPE_HASH,
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.id = BPF_MAP_ID_KEY,
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.size_key = sizeof(__u32),
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.size_value = sizeof(struct rss_key),
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.max_elem = 256,
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.pinning = PIN_GLOBAL_NS,
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};
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__section("cls_q") int
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match_q(struct __sk_buff *skb)
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{
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__u32 queue = skb->cb[1];
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volatile __u32 q = 0xdeadbeef;
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__u32 match_queue = QUEUE_OFFSET + q;
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/* printt("match_q$i() queue = %d\n", queue); */
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if (queue != match_queue)
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return TC_ACT_OK;
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return TC_ACT_UNSPEC;
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}
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struct ipv4_l3_l4_tuple {
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__u32 src_addr;
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__u32 dst_addr;
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__u16 dport;
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__u16 sport;
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} __attribute__((packed));
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struct ipv6_l3_l4_tuple {
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__u8 src_addr[16];
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__u8 dst_addr[16];
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__u16 dport;
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__u16 sport;
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} __attribute__((packed));
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static const __u8 def_rss_key[] = {
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0xd1, 0x81, 0xc6, 0x2c,
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0xf7, 0xf4, 0xdb, 0x5b,
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0x19, 0x83, 0xa2, 0xfc,
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0x94, 0x3e, 0x1a, 0xdb,
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0xd9, 0x38, 0x9e, 0x6b,
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0xd1, 0x03, 0x9c, 0x2c,
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0xa7, 0x44, 0x99, 0xad,
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0x59, 0x3d, 0x56, 0xd9,
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0xf3, 0x25, 0x3c, 0x06,
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0x2a, 0xdc, 0x1f, 0xfc,
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};
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static __u32 __attribute__((always_inline))
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rte_softrss_be(const __u32 *input_tuple, const uint8_t *rss_key,
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__u8 input_len)
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{
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__u32 i, j, hash = 0;
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#pragma unroll
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for (j = 0; j < input_len; j++) {
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#pragma unroll
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for (i = 0; i < 32; i++) {
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if (input_tuple[j] & (1 << (31 - i))) {
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hash ^= ((const __u32 *)def_rss_key)[j] << i |
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(__u32)((uint64_t)
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(((const __u32 *)def_rss_key)[j + 1])
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>> (32 - i));
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}
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}
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}
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return hash;
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}
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static int __attribute__((always_inline))
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rss_l3_l4(struct __sk_buff *skb)
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{
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void *data_end = (void *)(long)skb->data_end;
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void *data = (void *)(long)skb->data;
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__u16 proto = (__u16)skb->protocol;
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__u32 key_idx = 0xdeadbeef;
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__u32 hash;
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struct rss_key *rsskey;
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__u64 off = ETH_HLEN;
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int j;
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__u8 *key = 0;
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__u32 len;
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__u32 queue = 0;
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rsskey = map_lookup_elem(&map_keys, &key_idx);
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if (!rsskey) {
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printt("hash(): rss key is not configured\n");
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return TC_ACT_OK;
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}
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key = (__u8 *)rsskey->key;
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/* Get correct proto for 802.1ad */
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if (skb->vlan_present && skb->vlan_proto == htons(ETH_P_8021AD)) {
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if (data + ETH_ALEN * 2 + sizeof(struct vlan_hdr) +
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sizeof(proto) > data_end)
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return TC_ACT_OK;
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proto = *(__u16 *)(data + ETH_ALEN * 2 +
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sizeof(struct vlan_hdr));
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off += sizeof(struct vlan_hdr);
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}
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if (proto == htons(ETH_P_IP)) {
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if (data + off + sizeof(struct iphdr) + sizeof(__u32)
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> data_end)
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return TC_ACT_OK;
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__u8 *src_dst_addr = data + off + offsetof(struct iphdr, saddr);
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__u8 *src_dst_port = data + off + sizeof(struct iphdr);
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struct ipv4_l3_l4_tuple v4_tuple = {
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.src_addr = IPv4(*(src_dst_addr + 0),
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*(src_dst_addr + 1),
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*(src_dst_addr + 2),
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*(src_dst_addr + 3)),
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.dst_addr = IPv4(*(src_dst_addr + 4),
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*(src_dst_addr + 5),
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*(src_dst_addr + 6),
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*(src_dst_addr + 7)),
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.sport = PORT(*(src_dst_port + 0),
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*(src_dst_port + 1)),
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.dport = PORT(*(src_dst_port + 2),
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*(src_dst_port + 3)),
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};
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__u8 input_len = sizeof(v4_tuple) / sizeof(__u32);
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if (rsskey->hash_fields & (1 << HASH_FIELD_IPV4_L3))
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input_len--;
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hash = rte_softrss_be((__u32 *)&v4_tuple, key, 3);
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} else if (proto == htons(ETH_P_IPV6)) {
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if (data + off + sizeof(struct ipv6hdr) +
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sizeof(__u32) > data_end)
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return TC_ACT_OK;
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__u8 *src_dst_addr = data + off +
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offsetof(struct ipv6hdr, saddr);
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__u8 *src_dst_port = data + off +
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sizeof(struct ipv6hdr);
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struct ipv6_l3_l4_tuple v6_tuple;
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for (j = 0; j < 4; j++)
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*((uint32_t *)&v6_tuple.src_addr + j) =
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__builtin_bswap32(*((uint32_t *)
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src_dst_addr + j));
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for (j = 0; j < 4; j++)
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*((uint32_t *)&v6_tuple.dst_addr + j) =
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__builtin_bswap32(*((uint32_t *)
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src_dst_addr + 4 + j));
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v6_tuple.sport = PORT(*(src_dst_port + 0),
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*(src_dst_port + 1));
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v6_tuple.dport = PORT(*(src_dst_port + 2),
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*(src_dst_port + 3));
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__u8 input_len = sizeof(v6_tuple) / sizeof(__u32);
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if (rsskey->hash_fields & (1 << HASH_FIELD_IPV6_L3))
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input_len--;
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hash = rte_softrss_be((__u32 *)&v6_tuple, key, 9);
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} else {
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return TC_ACT_PIPE;
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}
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queue = rsskey->queues[(hash % rsskey->nb_queues) &
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(TAP_MAX_QUEUES - 1)];
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skb->cb[1] = QUEUE_OFFSET + queue;
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/* printt(">>>>> rss_l3_l4 hash=0x%x queue=%u\n", hash, queue); */
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return TC_ACT_RECLASSIFY;
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}
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#define RSS(L) \
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__section(#L) int \
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L ## _hash(struct __sk_buff *skb) \
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{ \
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return rss_ ## L (skb); \
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}
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RSS(l3_l4)
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BPF_LICENSE("Dual BSD/GPL");
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