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