1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20#include <stddef.h>
21#include <stdbool.h>
22#include <linux/bpf.h>
23
24#include <linux/in.h>
25#include <linux/if_ether.h>
26#include <linux/ip.h>
27#include <linux/ipv6.h>
28
29#include <linux/udp.h>
30#include <linux/tcp.h>
31
32#include <bpf/bpf_helpers.h>
33#include <bpf/bpf_endian.h>
34#include <linux/virtio_net.h>
35
36#define INDIRECTION_TABLE_SIZE 128
37#define HASH_CALCULATION_BUFFER_SIZE 36
38
39struct rss_config_t {
40 __u8 redirect;
41 __u8 populate_hash;
42 __u32 hash_types;
43 __u16 indirections_len;
44 __u16 default_queue;
45} __attribute__((packed));
46
47struct toeplitz_key_data_t {
48 __u32 leftmost_32_bits;
49 __u8 next_byte[HASH_CALCULATION_BUFFER_SIZE];
50};
51
52struct packet_hash_info_t {
53 __u8 is_ipv4;
54 __u8 is_ipv6;
55 __u8 is_udp;
56 __u8 is_tcp;
57 __u8 is_ipv6_ext_src;
58 __u8 is_ipv6_ext_dst;
59 __u8 is_fragmented;
60
61 __u16 src_port;
62 __u16 dst_port;
63
64 union {
65 struct {
66 __be32 in_src;
67 __be32 in_dst;
68 };
69
70 struct {
71 struct in6_addr in6_src;
72 struct in6_addr in6_dst;
73 struct in6_addr in6_ext_src;
74 struct in6_addr in6_ext_dst;
75 };
76 };
77};
78
79struct bpf_map_def SEC("maps")
80tap_rss_map_configurations = {
81 .type = BPF_MAP_TYPE_ARRAY,
82 .key_size = sizeof(__u32),
83 .value_size = sizeof(struct rss_config_t),
84 .max_entries = 1,
85};
86
87struct bpf_map_def SEC("maps")
88tap_rss_map_toeplitz_key = {
89 .type = BPF_MAP_TYPE_ARRAY,
90 .key_size = sizeof(__u32),
91 .value_size = sizeof(struct toeplitz_key_data_t),
92 .max_entries = 1,
93};
94
95struct bpf_map_def SEC("maps")
96tap_rss_map_indirection_table = {
97 .type = BPF_MAP_TYPE_ARRAY,
98 .key_size = sizeof(__u32),
99 .value_size = sizeof(__u16),
100 .max_entries = INDIRECTION_TABLE_SIZE,
101};
102
103static inline void net_rx_rss_add_chunk(__u8 *rss_input, size_t *bytes_written,
104 const void *ptr, size_t size) {
105 __builtin_memcpy(&rss_input[*bytes_written], ptr, size);
106 *bytes_written += size;
107}
108
109static inline
110void net_toeplitz_add(__u32 *result,
111 __u8 *input,
112 __u32 len
113 , struct toeplitz_key_data_t *key) {
114
115 __u32 accumulator = *result;
116 __u32 leftmost_32_bits = key->leftmost_32_bits;
117 __u32 byte;
118
119 for (byte = 0; byte < HASH_CALCULATION_BUFFER_SIZE; byte++) {
120 __u8 input_byte = input[byte];
121 __u8 key_byte = key->next_byte[byte];
122 __u8 bit;
123
124 for (bit = 0; bit < 8; bit++) {
125 if (input_byte & (1 << 7)) {
126 accumulator ^= leftmost_32_bits;
127 }
128
129 leftmost_32_bits =
130 (leftmost_32_bits << 1) | ((key_byte & (1 << 7)) >> 7);
131
132 input_byte <<= 1;
133 key_byte <<= 1;
134 }
135 }
136
137 *result = accumulator;
138}
139
140
141static inline int ip6_extension_header_type(__u8 hdr_type)
142{
143 switch (hdr_type) {
144 case IPPROTO_HOPOPTS:
145 case IPPROTO_ROUTING:
146 case IPPROTO_FRAGMENT:
147 case IPPROTO_ICMPV6:
148 case IPPROTO_NONE:
149 case IPPROTO_DSTOPTS:
150 case IPPROTO_MH:
151 return 1;
152 default:
153 return 0;
154 }
155}
156
157
158
159
160
161
162
163
164#define IP6_EXTENSIONS_COUNT 11
165#define IP6_OPTIONS_COUNT 30
166
167static inline int parse_ipv6_ext(struct __sk_buff *skb,
168 struct packet_hash_info_t *info,
169 __u8 *l4_protocol, size_t *l4_offset)
170{
171 int err = 0;
172
173 if (!ip6_extension_header_type(*l4_protocol)) {
174 return 0;
175 }
176
177 struct ipv6_opt_hdr ext_hdr = {};
178
179 for (unsigned int i = 0; i < IP6_EXTENSIONS_COUNT; ++i) {
180
181 err = bpf_skb_load_bytes_relative(skb, *l4_offset, &ext_hdr,
182 sizeof(ext_hdr), BPF_HDR_START_NET);
183 if (err) {
184 goto error;
185 }
186
187 if (*l4_protocol == IPPROTO_ROUTING) {
188 struct ipv6_rt_hdr ext_rt = {};
189
190 err = bpf_skb_load_bytes_relative(skb, *l4_offset, &ext_rt,
191 sizeof(ext_rt), BPF_HDR_START_NET);
192 if (err) {
193 goto error;
194 }
195
196 if ((ext_rt.type == IPV6_SRCRT_TYPE_2) &&
197 (ext_rt.hdrlen == sizeof(struct in6_addr) / 8) &&
198 (ext_rt.segments_left == 1)) {
199
200 err = bpf_skb_load_bytes_relative(skb,
201 *l4_offset + offsetof(struct rt2_hdr, addr),
202 &info->in6_ext_dst, sizeof(info->in6_ext_dst),
203 BPF_HDR_START_NET);
204 if (err) {
205 goto error;
206 }
207
208 info->is_ipv6_ext_dst = 1;
209 }
210
211 } else if (*l4_protocol == IPPROTO_DSTOPTS) {
212 struct ipv6_opt_t {
213 __u8 type;
214 __u8 length;
215 } __attribute__((packed)) opt = {};
216
217 size_t opt_offset = sizeof(ext_hdr);
218
219 for (unsigned int j = 0; j < IP6_OPTIONS_COUNT; ++j) {
220 err = bpf_skb_load_bytes_relative(skb, *l4_offset + opt_offset,
221 &opt, sizeof(opt), BPF_HDR_START_NET);
222 if (err) {
223 goto error;
224 }
225
226 if (opt.type == IPV6_TLV_HAO) {
227 err = bpf_skb_load_bytes_relative(skb,
228 *l4_offset + opt_offset
229 + offsetof(struct ipv6_destopt_hao, addr),
230 &info->in6_ext_src, sizeof(info->in6_ext_src),
231 BPF_HDR_START_NET);
232 if (err) {
233 goto error;
234 }
235
236 info->is_ipv6_ext_src = 1;
237 break;
238 }
239
240 opt_offset += (opt.type == IPV6_TLV_PAD1) ?
241 1 : opt.length + sizeof(opt);
242
243 if (opt_offset + 1 >= ext_hdr.hdrlen * 8) {
244 break;
245 }
246 }
247 } else if (*l4_protocol == IPPROTO_FRAGMENT) {
248 info->is_fragmented = true;
249 }
250
251 *l4_protocol = ext_hdr.nexthdr;
252 *l4_offset += (ext_hdr.hdrlen + 1) * 8;
253
254 if (!ip6_extension_header_type(ext_hdr.nexthdr)) {
255 return 0;
256 }
257 }
258
259 return 0;
260error:
261 return err;
262}
263
264static __be16 parse_eth_type(struct __sk_buff *skb)
265{
266 unsigned int offset = 12;
267 __be16 ret = 0;
268 int err = 0;
269
270 err = bpf_skb_load_bytes_relative(skb, offset, &ret, sizeof(ret),
271 BPF_HDR_START_MAC);
272 if (err) {
273 return 0;
274 }
275
276 switch (bpf_ntohs(ret)) {
277 case ETH_P_8021AD:
278 offset += 4;
279 case ETH_P_8021Q:
280 offset += 4;
281 err = bpf_skb_load_bytes_relative(skb, offset, &ret, sizeof(ret),
282 BPF_HDR_START_MAC);
283 default:
284 break;
285 }
286
287 if (err) {
288 return 0;
289 }
290
291 return ret;
292}
293
294static inline int parse_packet(struct __sk_buff *skb,
295 struct packet_hash_info_t *info)
296{
297 int err = 0;
298
299 if (!info || !skb) {
300 return -1;
301 }
302
303 size_t l4_offset = 0;
304 __u8 l4_protocol = 0;
305 __u16 l3_protocol = bpf_ntohs(parse_eth_type(skb));
306 if (l3_protocol == 0) {
307 err = -1;
308 goto error;
309 }
310
311 if (l3_protocol == ETH_P_IP) {
312 info->is_ipv4 = 1;
313
314 struct iphdr ip = {};
315 err = bpf_skb_load_bytes_relative(skb, 0, &ip, sizeof(ip),
316 BPF_HDR_START_NET);
317 if (err) {
318 goto error;
319 }
320
321 info->in_src = ip.saddr;
322 info->in_dst = ip.daddr;
323 info->is_fragmented = !!ip.frag_off;
324
325 l4_protocol = ip.protocol;
326 l4_offset = ip.ihl * 4;
327 } else if (l3_protocol == ETH_P_IPV6) {
328 info->is_ipv6 = 1;
329
330 struct ipv6hdr ip6 = {};
331 err = bpf_skb_load_bytes_relative(skb, 0, &ip6, sizeof(ip6),
332 BPF_HDR_START_NET);
333 if (err) {
334 goto error;
335 }
336
337 info->in6_src = ip6.saddr;
338 info->in6_dst = ip6.daddr;
339
340 l4_protocol = ip6.nexthdr;
341 l4_offset = sizeof(ip6);
342
343 err = parse_ipv6_ext(skb, info, &l4_protocol, &l4_offset);
344 if (err) {
345 goto error;
346 }
347 }
348
349 if (l4_protocol != 0 && !info->is_fragmented) {
350 if (l4_protocol == IPPROTO_TCP) {
351 info->is_tcp = 1;
352
353 struct tcphdr tcp = {};
354 err = bpf_skb_load_bytes_relative(skb, l4_offset, &tcp, sizeof(tcp),
355 BPF_HDR_START_NET);
356 if (err) {
357 goto error;
358 }
359
360 info->src_port = tcp.source;
361 info->dst_port = tcp.dest;
362 } else if (l4_protocol == IPPROTO_UDP) {
363 info->is_udp = 1;
364
365 struct udphdr udp = {};
366 err = bpf_skb_load_bytes_relative(skb, l4_offset, &udp, sizeof(udp),
367 BPF_HDR_START_NET);
368 if (err) {
369 goto error;
370 }
371
372 info->src_port = udp.source;
373 info->dst_port = udp.dest;
374 }
375 }
376
377 return 0;
378
379error:
380 return err;
381}
382
383static inline __u32 calculate_rss_hash(struct __sk_buff *skb,
384 struct rss_config_t *config, struct toeplitz_key_data_t *toe)
385{
386 __u8 rss_input[HASH_CALCULATION_BUFFER_SIZE] = {};
387 size_t bytes_written = 0;
388 __u32 result = 0;
389 int err = 0;
390 struct packet_hash_info_t packet_info = {};
391
392 err = parse_packet(skb, &packet_info);
393 if (err) {
394 return 0;
395 }
396
397 if (packet_info.is_ipv4) {
398 if (packet_info.is_tcp &&
399 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) {
400
401 net_rx_rss_add_chunk(rss_input, &bytes_written,
402 &packet_info.in_src,
403 sizeof(packet_info.in_src));
404 net_rx_rss_add_chunk(rss_input, &bytes_written,
405 &packet_info.in_dst,
406 sizeof(packet_info.in_dst));
407 net_rx_rss_add_chunk(rss_input, &bytes_written,
408 &packet_info.src_port,
409 sizeof(packet_info.src_port));
410 net_rx_rss_add_chunk(rss_input, &bytes_written,
411 &packet_info.dst_port,
412 sizeof(packet_info.dst_port));
413 } else if (packet_info.is_udp &&
414 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
415
416 net_rx_rss_add_chunk(rss_input, &bytes_written,
417 &packet_info.in_src,
418 sizeof(packet_info.in_src));
419 net_rx_rss_add_chunk(rss_input, &bytes_written,
420 &packet_info.in_dst,
421 sizeof(packet_info.in_dst));
422 net_rx_rss_add_chunk(rss_input, &bytes_written,
423 &packet_info.src_port,
424 sizeof(packet_info.src_port));
425 net_rx_rss_add_chunk(rss_input, &bytes_written,
426 &packet_info.dst_port,
427 sizeof(packet_info.dst_port));
428 } else if (config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
429 net_rx_rss_add_chunk(rss_input, &bytes_written,
430 &packet_info.in_src,
431 sizeof(packet_info.in_src));
432 net_rx_rss_add_chunk(rss_input, &bytes_written,
433 &packet_info.in_dst,
434 sizeof(packet_info.in_dst));
435 }
436 } else if (packet_info.is_ipv6) {
437 if (packet_info.is_tcp &&
438 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) {
439
440 if (packet_info.is_ipv6_ext_src &&
441 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_TCP_EX) {
442
443 net_rx_rss_add_chunk(rss_input, &bytes_written,
444 &packet_info.in6_ext_src,
445 sizeof(packet_info.in6_ext_src));
446 } else {
447 net_rx_rss_add_chunk(rss_input, &bytes_written,
448 &packet_info.in6_src,
449 sizeof(packet_info.in6_src));
450 }
451 if (packet_info.is_ipv6_ext_dst &&
452 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_TCP_EX) {
453
454 net_rx_rss_add_chunk(rss_input, &bytes_written,
455 &packet_info.in6_ext_dst,
456 sizeof(packet_info.in6_ext_dst));
457 } else {
458 net_rx_rss_add_chunk(rss_input, &bytes_written,
459 &packet_info.in6_dst,
460 sizeof(packet_info.in6_dst));
461 }
462 net_rx_rss_add_chunk(rss_input, &bytes_written,
463 &packet_info.src_port,
464 sizeof(packet_info.src_port));
465 net_rx_rss_add_chunk(rss_input, &bytes_written,
466 &packet_info.dst_port,
467 sizeof(packet_info.dst_port));
468 } else if (packet_info.is_udp &&
469 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) {
470
471 if (packet_info.is_ipv6_ext_src &&
472 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_UDP_EX) {
473
474 net_rx_rss_add_chunk(rss_input, &bytes_written,
475 &packet_info.in6_ext_src,
476 sizeof(packet_info.in6_ext_src));
477 } else {
478 net_rx_rss_add_chunk(rss_input, &bytes_written,
479 &packet_info.in6_src,
480 sizeof(packet_info.in6_src));
481 }
482 if (packet_info.is_ipv6_ext_dst &&
483 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_UDP_EX) {
484
485 net_rx_rss_add_chunk(rss_input, &bytes_written,
486 &packet_info.in6_ext_dst,
487 sizeof(packet_info.in6_ext_dst));
488 } else {
489 net_rx_rss_add_chunk(rss_input, &bytes_written,
490 &packet_info.in6_dst,
491 sizeof(packet_info.in6_dst));
492 }
493
494 net_rx_rss_add_chunk(rss_input, &bytes_written,
495 &packet_info.src_port,
496 sizeof(packet_info.src_port));
497 net_rx_rss_add_chunk(rss_input, &bytes_written,
498 &packet_info.dst_port,
499 sizeof(packet_info.dst_port));
500
501 } else if (config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
502 if (packet_info.is_ipv6_ext_src &&
503 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_IP_EX) {
504
505 net_rx_rss_add_chunk(rss_input, &bytes_written,
506 &packet_info.in6_ext_src,
507 sizeof(packet_info.in6_ext_src));
508 } else {
509 net_rx_rss_add_chunk(rss_input, &bytes_written,
510 &packet_info.in6_src,
511 sizeof(packet_info.in6_src));
512 }
513 if (packet_info.is_ipv6_ext_dst &&
514 config->hash_types & VIRTIO_NET_RSS_HASH_TYPE_IP_EX) {
515
516 net_rx_rss_add_chunk(rss_input, &bytes_written,
517 &packet_info.in6_ext_dst,
518 sizeof(packet_info.in6_ext_dst));
519 } else {
520 net_rx_rss_add_chunk(rss_input, &bytes_written,
521 &packet_info.in6_dst,
522 sizeof(packet_info.in6_dst));
523 }
524 }
525 }
526
527 if (bytes_written) {
528 net_toeplitz_add(&result, rss_input, bytes_written, toe);
529 }
530
531 return result;
532}
533
534SEC("tun_rss_steering")
535int tun_rss_steering_prog(struct __sk_buff *skb)
536{
537
538 struct rss_config_t *config;
539 struct toeplitz_key_data_t *toe;
540
541 __u32 key = 0;
542 __u32 hash = 0;
543
544 config = bpf_map_lookup_elem(&tap_rss_map_configurations, &key);
545 toe = bpf_map_lookup_elem(&tap_rss_map_toeplitz_key, &key);
546
547 if (config && toe) {
548 if (!config->redirect) {
549 return config->default_queue;
550 }
551
552 hash = calculate_rss_hash(skb, config, toe);
553 if (hash) {
554 __u32 table_idx = hash % config->indirections_len;
555 __u16 *queue = 0;
556
557 queue = bpf_map_lookup_elem(&tap_rss_map_indirection_table,
558 &table_idx);
559
560 if (queue) {
561 return *queue;
562 }
563 }
564
565 return config->default_queue;
566 }
567
568 return -1;
569}
570
571char _license[] SEC("license") = "GPL v2";
572
