| /* |
| * eBPF RSS program |
| * |
| * Developed by Daynix Computing LTD (http://www.daynix.com) |
| * |
| * Authors: |
| * Andrew Melnychenko <andrew@daynix.com> |
| * Yuri Benditovich <yuri.benditovich@daynix.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2. See |
| * the COPYING file in the top-level directory. |
| * |
| * Prepare: |
| * Requires llvm, clang, bpftool, linux kernel tree |
| * |
| * Build rss.bpf.skeleton.h: |
| * make -f Makefile.ebpf clean all |
| */ |
| |
| #include <stddef.h> |
| #include <stdbool.h> |
| #include <linux/bpf.h> |
| |
| #include <linux/in.h> |
| #include <linux/if_ether.h> |
| #include <linux/ip.h> |
| #include <linux/ipv6.h> |
| |
| #include <linux/udp.h> |
| #include <linux/tcp.h> |
| |
| #include <bpf/bpf_helpers.h> |
| #include <bpf/bpf_endian.h> |
| #include <linux/virtio_net.h> |
| |
| #define INDIRECTION_TABLE_SIZE 128 |
| #define HASH_CALCULATION_BUFFER_SIZE 36 |
| |
| struct rss_config_t { |
| __u8 redirect; |
| __u8 populate_hash; |
| __u32 hash_types; |
| __u16 indirections_len; |
| __u16 default_queue; |
| } __attribute__((packed)); |
| |
| struct toeplitz_key_data_t { |
| __u32 leftmost_32_bits; |
| __u8 next_byte[HASH_CALCULATION_BUFFER_SIZE]; |
| }; |
| |
| struct packet_hash_info_t { |
| __u8 is_ipv4; |
| __u8 is_ipv6; |
| __u8 is_udp; |
| __u8 is_tcp; |
| __u8 is_ipv6_ext_src; |
| __u8 is_ipv6_ext_dst; |
| __u8 is_fragmented; |
| |
| __u16 src_port; |
| __u16 dst_port; |
| |
| union { |
| struct { |
| __be32 in_src; |
| __be32 in_dst; |
| }; |
| |
| struct { |
| struct in6_addr in6_src; |
| struct in6_addr in6_dst; |
| struct in6_addr in6_ext_src; |
| struct in6_addr in6_ext_dst; |
| }; |
| }; |
| }; |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __uint(key_size, sizeof(__u32)); |
| __uint(value_size, sizeof(struct rss_config_t)); |
| __uint(max_entries, 1); |
| __uint(map_flags, BPF_F_MMAPABLE); |
| } tap_rss_map_configurations SEC(".maps"); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __uint(key_size, sizeof(__u32)); |
| __uint(value_size, sizeof(struct toeplitz_key_data_t)); |
| __uint(max_entries, 1); |
| __uint(map_flags, BPF_F_MMAPABLE); |
| } tap_rss_map_toeplitz_key SEC(".maps"); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __uint(key_size, sizeof(__u32)); |
| __uint(value_size, sizeof(__u16)); |
| __uint(max_entries, INDIRECTION_TABLE_SIZE); |
| __uint(map_flags, BPF_F_MMAPABLE); |
| } tap_rss_map_indirection_table SEC(".maps"); |
| |
| static inline void net_rx_rss_add_chunk(__u8 *rss_input, size_t *bytes_written, |
| const void *ptr, size_t size) { |
| __builtin_memcpy(&rss_input[*bytes_written], ptr, size); |
| *bytes_written += size; |
| } |
| |
| static inline |
| void net_toeplitz_add(__u32 *result, |
| __u8 *input, |
| __u32 len |
| , struct toeplitz_key_data_t *key) { |
| |
| __u32 accumulator = *result; |
| __u32 leftmost_32_bits = key->leftmost_32_bits; |
| __u32 byte; |
| |
| for (byte = 0; byte < HASH_CALCULATION_BUFFER_SIZE; byte++) { |
| __u8 input_byte = input[byte]; |
| __u8 key_byte = key->next_byte[byte]; |
| __u8 bit; |
| |
| for (bit = 0; bit < 8; bit++) { |
| if (input_byte & (1 << 7)) { |
| accumulator ^= leftmost_32_bits; |
| } |
| |
| leftmost_32_bits = |
| (leftmost_32_bits << 1) | ((key_byte & (1 << 7)) >> 7); |
| |
| input_byte <<= 1; |
| key_byte <<= 1; |
| } |
| } |
| |
| *result = accumulator; |
| } |
| |
| |
| static inline int ip6_extension_header_type(__u8 hdr_type) |
| { |
| switch (hdr_type) { |
| case IPPROTO_HOPOPTS: |
| case IPPROTO_ROUTING: |
| case IPPROTO_FRAGMENT: |
| case IPPROTO_ICMPV6: |
| case IPPROTO_NONE: |
| case IPPROTO_DSTOPTS: |
| case IPPROTO_MH: |
| return 1; |
| default: |
| return 0; |
| } |
| } |
| /* |
| * According to |
| * https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml |
| * we expect that there are would be no more than 11 extensions in IPv6 header, |
| * also there is 27 TLV options for Destination and Hop-by-hop extensions. |
| * Need to choose reasonable amount of maximum extensions/options we may |
| * check to find ext src/dst. |
| */ |
| #define IP6_EXTENSIONS_COUNT 11 |
| #define IP6_OPTIONS_COUNT 30 |
| |
| static inline int parse_ipv6_ext(struct __sk_buff *skb, |
| struct packet_hash_info_t *info, |
| __u8 *l4_protocol, size_t *l4_offset) |
| { |
| int err = 0; |
| |
| if (!ip6_extension_header_type(*l4_protocol)) { |
| return 0; |
| } |
| |
| struct ipv6_opt_hdr ext_hdr = {}; |
| |
| for (unsigned int i = 0; i < IP6_EXTENSIONS_COUNT; ++i) { |
| |
| err = bpf_skb_load_bytes_relative(skb, *l4_offset, &ext_hdr, |
| sizeof(ext_hdr), BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| if (*l4_protocol == IPPROTO_ROUTING) { |
| struct ipv6_rt_hdr ext_rt = {}; |
| |
| err = bpf_skb_load_bytes_relative(skb, *l4_offset, &ext_rt, |
| sizeof(ext_rt), BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| if ((ext_rt.type == IPV6_SRCRT_TYPE_2) && |
| (ext_rt.hdrlen == sizeof(struct in6_addr) / 8) && |
| (ext_rt.segments_left == 1)) { |
| |
| err = bpf_skb_load_bytes_relative(skb, |
| *l4_offset + offsetof(struct rt2_hdr, addr), |
| &info->in6_ext_dst, sizeof(info->in6_ext_dst), |
| BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| info->is_ipv6_ext_dst = 1; |
| } |
| |
| } else if (*l4_protocol == IPPROTO_DSTOPTS) { |
| struct ipv6_opt_t { |
| __u8 type; |
| __u8 length; |
| } __attribute__((packed)) opt = {}; |
| |
| size_t opt_offset = sizeof(ext_hdr); |
| |
| for (unsigned int j = 0; j < IP6_OPTIONS_COUNT; ++j) { |
| err = bpf_skb_load_bytes_relative(skb, *l4_offset + opt_offset, |
| &opt, sizeof(opt), BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| if (opt.type == IPV6_TLV_HAO) { |
| err = bpf_skb_load_bytes_relative(skb, |
| *l4_offset + opt_offset |
| + offsetof(struct ipv6_destopt_hao, addr), |
| &info->in6_ext_src, sizeof(info->in6_ext_src), |
| BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| info->is_ipv6_ext_src = 1; |
| break; |
| } |
| |
| opt_offset += (opt.type == IPV6_TLV_PAD1) ? |
| 1 : opt.length + sizeof(opt); |
| |
| if (opt_offset + 1 >= ext_hdr.hdrlen * 8) { |
| break; |
| } |
| } |
| } else if (*l4_protocol == IPPROTO_FRAGMENT) { |
| info->is_fragmented = true; |
| } |
| |
| *l4_protocol = ext_hdr.nexthdr; |
| *l4_offset += (ext_hdr.hdrlen + 1) * 8; |
| |
| if (!ip6_extension_header_type(ext_hdr.nexthdr)) { |
| return 0; |
| } |
| } |
| |
| return 0; |
| error: |
| return err; |
| } |
| |
| static __be16 parse_eth_type(struct __sk_buff *skb) |
| { |
| unsigned int offset = 12; |
| __be16 ret = 0; |
| int err = 0; |
| |
| err = bpf_skb_load_bytes_relative(skb, offset, &ret, sizeof(ret), |
| BPF_HDR_START_MAC); |
| if (err) { |
| return 0; |
| } |
| |
| switch (bpf_ntohs(ret)) { |
| case ETH_P_8021AD: |
| offset += 4; |
| case ETH_P_8021Q: |
| offset += 4; |
| err = bpf_skb_load_bytes_relative(skb, offset, &ret, sizeof(ret), |
| BPF_HDR_START_MAC); |
| default: |
| break; |
| } |
| |
| if (err) { |
| return 0; |
| } |
| |
| return ret; |
| } |
| |
| static inline int parse_packet(struct __sk_buff *skb, |
| struct packet_hash_info_t *info) |
| { |
| int err = 0; |
| |
| if (!info || !skb) { |
| return -1; |
| } |
| |
| size_t l4_offset = 0; |
| __u8 l4_protocol = 0; |
| __u16 l3_protocol = bpf_ntohs(parse_eth_type(skb)); |
| if (l3_protocol == 0) { |
| err = -1; |
| goto error; |
| } |
| |
| if (l3_protocol == ETH_P_IP) { |
| info->is_ipv4 = 1; |
| |
| struct iphdr ip = {}; |
| err = bpf_skb_load_bytes_relative(skb, 0, &ip, sizeof(ip), |
| BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| info->in_src = ip.saddr; |
| info->in_dst = ip.daddr; |
| info->is_fragmented = !!(bpf_ntohs(ip.frag_off) & (0x2000 | 0x1fff)); |
| |
| l4_protocol = ip.protocol; |
| l4_offset = ip.ihl * 4; |
| } else if (l3_protocol == ETH_P_IPV6) { |
| info->is_ipv6 = 1; |
| |
| struct ipv6hdr ip6 = {}; |
| err = bpf_skb_load_bytes_relative(skb, 0, &ip6, sizeof(ip6), |
| BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| info->in6_src = ip6.saddr; |
| info->in6_dst = ip6.daddr; |
| |
| l4_protocol = ip6.nexthdr; |
| l4_offset = sizeof(ip6); |
| |
| err = parse_ipv6_ext(skb, info, &l4_protocol, &l4_offset); |
| if (err) { |
| goto error; |
| } |
| } |
| |
| if (l4_protocol != 0 && !info->is_fragmented) { |
| if (l4_protocol == IPPROTO_TCP) { |
| info->is_tcp = 1; |
| |
| struct tcphdr tcp = {}; |
| err = bpf_skb_load_bytes_relative(skb, l4_offset, &tcp, sizeof(tcp), |
| BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| info->src_port = tcp.source; |
| info->dst_port = tcp.dest; |
| } else if (l4_protocol == IPPROTO_UDP) { /* TODO: add udplite? */ |
| info->is_udp = 1; |
| |
| struct udphdr udp = {}; |
| err = bpf_skb_load_bytes_relative(skb, l4_offset, &udp, sizeof(udp), |
| BPF_HDR_START_NET); |
| if (err) { |
| goto error; |
| } |
| |
| info->src_port = udp.source; |
| info->dst_port = udp.dest; |
| } |
| } |
| |
| return 0; |
| |
| error: |
| return err; |
| } |
| |
| static inline bool calculate_rss_hash(struct __sk_buff *skb, |
| struct rss_config_t *config, |
| struct toeplitz_key_data_t *toe, |
| __u32 *result) |
| { |
| __u8 rss_input[HASH_CALCULATION_BUFFER_SIZE] = {}; |
| size_t bytes_written = 0; |
| int err = 0; |
| struct packet_hash_info_t packet_info = {}; |
| |
| err = parse_packet(skb, &packet_info); |
| if (err) { |
| return false; |
| } |
| |
| if (packet_info.is_ipv4) { |
| if (packet_info.is_tcp && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) { |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in_src, |
| sizeof(packet_info.in_src)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in_dst, |
| sizeof(packet_info.in_dst)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.src_port, |
| sizeof(packet_info.src_port)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.dst_port, |
| sizeof(packet_info.dst_port)); |
| } else if (packet_info.is_udp && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) { |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in_src, |
| sizeof(packet_info.in_src)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in_dst, |
| sizeof(packet_info.in_dst)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.src_port, |
| sizeof(packet_info.src_port)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.dst_port, |
| sizeof(packet_info.dst_port)); |
| } else if (config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_IPv4) { |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in_src, |
| sizeof(packet_info.in_src)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in_dst, |
| sizeof(packet_info.in_dst)); |
| } |
| } else if (packet_info.is_ipv6) { |
| if (packet_info.is_tcp && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) { |
| |
| if (packet_info.is_ipv6_ext_src && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_TCP_EX) { |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_ext_src, |
| sizeof(packet_info.in6_ext_src)); |
| } else { |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_src, |
| sizeof(packet_info.in6_src)); |
| } |
| if (packet_info.is_ipv6_ext_dst && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_TCP_EX) { |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_ext_dst, |
| sizeof(packet_info.in6_ext_dst)); |
| } else { |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_dst, |
| sizeof(packet_info.in6_dst)); |
| } |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.src_port, |
| sizeof(packet_info.src_port)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.dst_port, |
| sizeof(packet_info.dst_port)); |
| } else if (packet_info.is_udp && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) { |
| |
| if (packet_info.is_ipv6_ext_src && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_UDP_EX) { |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_ext_src, |
| sizeof(packet_info.in6_ext_src)); |
| } else { |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_src, |
| sizeof(packet_info.in6_src)); |
| } |
| if (packet_info.is_ipv6_ext_dst && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_UDP_EX) { |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_ext_dst, |
| sizeof(packet_info.in6_ext_dst)); |
| } else { |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_dst, |
| sizeof(packet_info.in6_dst)); |
| } |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.src_port, |
| sizeof(packet_info.src_port)); |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.dst_port, |
| sizeof(packet_info.dst_port)); |
| |
| } else if (config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_IPv6) { |
| if (packet_info.is_ipv6_ext_src && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_IP_EX) { |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_ext_src, |
| sizeof(packet_info.in6_ext_src)); |
| } else { |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_src, |
| sizeof(packet_info.in6_src)); |
| } |
| if (packet_info.is_ipv6_ext_dst && |
| config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_IP_EX) { |
| |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_ext_dst, |
| sizeof(packet_info.in6_ext_dst)); |
| } else { |
| net_rx_rss_add_chunk(rss_input, &bytes_written, |
| &packet_info.in6_dst, |
| sizeof(packet_info.in6_dst)); |
| } |
| } |
| } |
| |
| if (!bytes_written) { |
| return false; |
| } |
| |
| net_toeplitz_add(result, rss_input, bytes_written, toe); |
| |
| return true; |
| } |
| |
| SEC("socket") |
| int tun_rss_steering_prog(struct __sk_buff *skb) |
| { |
| |
| struct rss_config_t *config; |
| struct toeplitz_key_data_t *toe; |
| |
| __u32 key = 0; |
| __u32 hash = 0; |
| |
| config = bpf_map_lookup_elem(&tap_rss_map_configurations, &key); |
| toe = bpf_map_lookup_elem(&tap_rss_map_toeplitz_key, &key); |
| |
| if (config && toe) { |
| if (!config->redirect) { |
| return config->default_queue; |
| } |
| |
| if (calculate_rss_hash(skb, config, toe, &hash)) { |
| __u32 table_idx = hash % config->indirections_len; |
| __u16 *queue = 0; |
| |
| queue = bpf_map_lookup_elem(&tap_rss_map_indirection_table, |
| &table_idx); |
| |
| if (queue) { |
| return *queue; |
| } |
| } |
| |
| return config->default_queue; |
| } |
| |
| return 0; |
| } |
| |
| char _license[] SEC("license") = "GPL v2"; |
