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path: root/drivers/net/tap/tap_bpf_program.c
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Diffstat (limited to 'drivers/net/tap/tap_bpf_program.c')
-rw-r--r--drivers/net/tap/tap_bpf_program.c224
1 files changed, 224 insertions, 0 deletions
diff --git a/drivers/net/tap/tap_bpf_program.c b/drivers/net/tap/tap_bpf_program.c
new file mode 100644
index 00000000..8abb3b76
--- /dev/null
+++ b/drivers/net/tap/tap_bpf_program.c
@@ -0,0 +1,224 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+ * Copyright 2017 Mellanox Technologies, Ltd.
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <asm/types.h>
+#include <linux/in.h>
+#include <linux/if.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/if_tunnel.h>
+#include <linux/filter.h>
+#include <linux/bpf.h>
+
+#include "tap_rss.h"
+
+/** Create IPv4 address */
+#define IPv4(a, b, c, d) ((__u32)(((a) & 0xff) << 24) | \
+ (((b) & 0xff) << 16) | \
+ (((c) & 0xff) << 8) | \
+ ((d) & 0xff))
+
+#define PORT(a, b) ((__u16)(((a) & 0xff) << 8) | \
+ ((b) & 0xff))
+
+/*
+ * The queue number is offset by a unique QUEUE_OFFSET, to distinguish
+ * packets that have gone through this rule (skb->cb[1] != 0) from others.
+ */
+#define QUEUE_OFFSET 0x7cafe800
+#define PIN_GLOBAL_NS 2
+
+#define KEY_IDX 0
+#define BPF_MAP_ID_KEY 1
+
+struct vlan_hdr {
+ __be16 proto;
+ __be16 tci;
+};
+
+struct bpf_elf_map __attribute__((section("maps"), used))
+map_keys = {
+ .type = BPF_MAP_TYPE_HASH,
+ .id = BPF_MAP_ID_KEY,
+ .size_key = sizeof(__u32),
+ .size_value = sizeof(struct rss_key),
+ .max_elem = 256,
+ .pinning = PIN_GLOBAL_NS,
+};
+
+__section("cls_q") int
+match_q(struct __sk_buff *skb)
+{
+ __u32 queue = skb->cb[1];
+ volatile __u32 q = 0xdeadbeef;
+ __u32 match_queue = QUEUE_OFFSET + q;
+
+ /* printt("match_q$i() queue = %d\n", queue); */
+
+ if (queue != match_queue)
+ return TC_ACT_OK;
+
+ /* queue match */
+ skb->cb[1] = 0;
+ return TC_ACT_UNSPEC;
+}
+
+
+struct ipv4_l3_l4_tuple {
+ __u32 src_addr;
+ __u32 dst_addr;
+ __u16 dport;
+ __u16 sport;
+} __attribute__((packed));
+
+struct ipv6_l3_l4_tuple {
+ __u8 src_addr[16];
+ __u8 dst_addr[16];
+ __u16 dport;
+ __u16 sport;
+} __attribute__((packed));
+
+static const __u8 def_rss_key[] = {
+ 0xd1, 0x81, 0xc6, 0x2c,
+ 0xf7, 0xf4, 0xdb, 0x5b,
+ 0x19, 0x83, 0xa2, 0xfc,
+ 0x94, 0x3e, 0x1a, 0xdb,
+ 0xd9, 0x38, 0x9e, 0x6b,
+ 0xd1, 0x03, 0x9c, 0x2c,
+ 0xa7, 0x44, 0x99, 0xad,
+ 0x59, 0x3d, 0x56, 0xd9,
+ 0xf3, 0x25, 0x3c, 0x06,
+ 0x2a, 0xdc, 0x1f, 0xfc,
+};
+
+static __u32 __attribute__((always_inline))
+rte_softrss_be(const __u32 *input_tuple, const uint8_t *rss_key,
+ __u8 input_len)
+{
+ __u32 i, j, hash = 0;
+#pragma unroll
+ for (j = 0; j < input_len; j++) {
+#pragma unroll
+ for (i = 0; i < 32; i++) {
+ if (input_tuple[j] & (1 << (31 - i))) {
+ hash ^= ((const __u32 *)def_rss_key)[j] << i |
+ (__u32)((uint64_t)
+ (((const __u32 *)def_rss_key)[j + 1])
+ >> (32 - i));
+ }
+ }
+ }
+ return hash;
+}
+
+static int __attribute__((always_inline))
+rss_l3_l4(struct __sk_buff *skb)
+{
+ void *data_end = (void *)(long)skb->data_end;
+ void *data = (void *)(long)skb->data;
+ __u16 proto = (__u16)skb->protocol;
+ __u32 key_idx = 0xdeadbeef;
+ __u32 hash;
+ struct rss_key *rsskey;
+ __u64 off = ETH_HLEN;
+ int j;
+ __u8 *key = 0;
+ __u32 len;
+ __u32 queue = 0;
+
+ rsskey = map_lookup_elem(&map_keys, &key_idx);
+ if (!rsskey) {
+ printt("hash(): rss key is not configured\n");
+ return TC_ACT_OK;
+ }
+ key = (__u8 *)rsskey->key;
+
+ /* Get correct proto for 802.1ad */
+ if (skb->vlan_present && skb->vlan_proto == htons(ETH_P_8021AD)) {
+ if (data + ETH_ALEN * 2 + sizeof(struct vlan_hdr) +
+ sizeof(proto) > data_end)
+ return TC_ACT_OK;
+ proto = *(__u16 *)(data + ETH_ALEN * 2 +
+ sizeof(struct vlan_hdr));
+ off += sizeof(struct vlan_hdr);
+ }
+
+ if (proto == htons(ETH_P_IP)) {
+ if (data + off + sizeof(struct iphdr) + sizeof(__u32)
+ > data_end)
+ return TC_ACT_OK;
+
+ __u8 *src_dst_addr = data + off + offsetof(struct iphdr, saddr);
+ __u8 *src_dst_port = data + off + sizeof(struct iphdr);
+ struct ipv4_l3_l4_tuple v4_tuple = {
+ .src_addr = IPv4(*(src_dst_addr + 0),
+ *(src_dst_addr + 1),
+ *(src_dst_addr + 2),
+ *(src_dst_addr + 3)),
+ .dst_addr = IPv4(*(src_dst_addr + 4),
+ *(src_dst_addr + 5),
+ *(src_dst_addr + 6),
+ *(src_dst_addr + 7)),
+ .sport = PORT(*(src_dst_port + 0),
+ *(src_dst_port + 1)),
+ .dport = PORT(*(src_dst_port + 2),
+ *(src_dst_port + 3)),
+ };
+ __u8 input_len = sizeof(v4_tuple) / sizeof(__u32);
+ if (rsskey->hash_fields & (1 << HASH_FIELD_IPV4_L3))
+ input_len--;
+ hash = rte_softrss_be((__u32 *)&v4_tuple, key, 3);
+ } else if (proto == htons(ETH_P_IPV6)) {
+ if (data + off + sizeof(struct ipv6hdr) +
+ sizeof(__u32) > data_end)
+ return TC_ACT_OK;
+ __u8 *src_dst_addr = data + off +
+ offsetof(struct ipv6hdr, saddr);
+ __u8 *src_dst_port = data + off +
+ sizeof(struct ipv6hdr);
+ struct ipv6_l3_l4_tuple v6_tuple;
+ for (j = 0; j < 4; j++)
+ *((uint32_t *)&v6_tuple.src_addr + j) =
+ __builtin_bswap32(*((uint32_t *)
+ src_dst_addr + j));
+ for (j = 0; j < 4; j++)
+ *((uint32_t *)&v6_tuple.dst_addr + j) =
+ __builtin_bswap32(*((uint32_t *)
+ src_dst_addr + 4 + j));
+ v6_tuple.sport = PORT(*(src_dst_port + 0),
+ *(src_dst_port + 1));
+ v6_tuple.dport = PORT(*(src_dst_port + 2),
+ *(src_dst_port + 3));
+
+ __u8 input_len = sizeof(v6_tuple) / sizeof(__u32);
+ if (rsskey->hash_fields & (1 << HASH_FIELD_IPV6_L3))
+ input_len--;
+ hash = rte_softrss_be((__u32 *)&v6_tuple, key, 9);
+ } else {
+ return TC_ACT_PIPE;
+ }
+
+ queue = rsskey->queues[(hash % rsskey->nb_queues) &
+ (TAP_MAX_QUEUES - 1)];
+ skb->cb[1] = QUEUE_OFFSET + queue;
+ /* printt(">>>>> rss_l3_l4 hash=0x%x queue=%u\n", hash, queue); */
+
+ return TC_ACT_RECLASSIFY;
+}
+
+#define RSS(L) \
+ __section(#L) int \
+ L ## _hash(struct __sk_buff *skb) \
+ { \
+ return rss_ ## L (skb); \
+ }
+
+RSS(l3_l4)
+
+BPF_LICENSE("Dual BSD/GPL");