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1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2017 Facebook
3#include <stddef.h>
4#include <stdbool.h>
5#include <string.h>
6#include <linux/pkt_cls.h>
7#include <linux/bpf.h>
8#include <linux/in.h>
9#include <linux/if_ether.h>
10#include <linux/ip.h>
11#include <linux/ipv6.h>
12#include <linux/icmp.h>
13#include <linux/icmpv6.h>
14#include <linux/tcp.h>
15#include <linux/udp.h>
16#include <bpf/bpf_helpers.h>
17#include <bpf/bpf_endian.h>
18#include "bpf_compiler.h"
19
20static __always_inline __u32 rol32(__u32 word, unsigned int shift)
21{
22 return (word << shift) | (word >> ((-shift) & 31));
23}
24
25/* copy paste of jhash from kernel sources to make sure llvm
26 * can compile it into valid sequence of bpf instructions
27 */
28#define __jhash_mix(a, b, c) \
29{ \
30 a -= c; a ^= rol32(c, 4); c += b; \
31 b -= a; b ^= rol32(a, 6); a += c; \
32 c -= b; c ^= rol32(b, 8); b += a; \
33 a -= c; a ^= rol32(c, 16); c += b; \
34 b -= a; b ^= rol32(a, 19); a += c; \
35 c -= b; c ^= rol32(b, 4); b += a; \
36}
37
38#define __jhash_final(a, b, c) \
39{ \
40 c ^= b; c -= rol32(b, 14); \
41 a ^= c; a -= rol32(c, 11); \
42 b ^= a; b -= rol32(a, 25); \
43 c ^= b; c -= rol32(b, 16); \
44 a ^= c; a -= rol32(c, 4); \
45 b ^= a; b -= rol32(a, 14); \
46 c ^= b; c -= rol32(b, 24); \
47}
48
49#define JHASH_INITVAL 0xdeadbeef
50
51typedef unsigned int u32;
52
53static __noinline
54u32 jhash(const void *key, u32 length, u32 initval)
55{
56 u32 a, b, c;
57 const unsigned char *k = key;
58
59 a = b = c = JHASH_INITVAL + length + initval;
60
61 while (length > 12) {
62 a += *(u32 *)(k);
63 b += *(u32 *)(k + 4);
64 c += *(u32 *)(k + 8);
65 __jhash_mix(a, b, c);
66 length -= 12;
67 k += 12;
68 }
69 switch (length) {
70 case 12: c += (u32)k[11]<<24;
71 case 11: c += (u32)k[10]<<16;
72 case 10: c += (u32)k[9]<<8;
73 case 9: c += k[8];
74 case 8: b += (u32)k[7]<<24;
75 case 7: b += (u32)k[6]<<16;
76 case 6: b += (u32)k[5]<<8;
77 case 5: b += k[4];
78 case 4: a += (u32)k[3]<<24;
79 case 3: a += (u32)k[2]<<16;
80 case 2: a += (u32)k[1]<<8;
81 case 1: a += k[0];
82 __jhash_final(a, b, c);
83 case 0: /* Nothing left to add */
84 break;
85 }
86
87 return c;
88}
89
90__noinline
91u32 __jhash_nwords(u32 a, u32 b, u32 c, u32 initval)
92{
93 a += initval;
94 b += initval;
95 c += initval;
96 __jhash_final(a, b, c);
97 return c;
98}
99
100__noinline
101u32 jhash_2words(u32 a, u32 b, u32 initval)
102{
103 return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
104}
105
106struct flow_key {
107 union {
108 __be32 src;
109 __be32 srcv6[4];
110 };
111 union {
112 __be32 dst;
113 __be32 dstv6[4];
114 };
115 union {
116 __u32 ports;
117 __u16 port16[2];
118 };
119 __u8 proto;
120};
121
122struct packet_description {
123 struct flow_key flow;
124 __u8 flags;
125};
126
127struct ctl_value {
128 union {
129 __u64 value;
130 __u32 ifindex;
131 __u8 mac[6];
132 };
133};
134
135struct vip_definition {
136 union {
137 __be32 vip;
138 __be32 vipv6[4];
139 };
140 __u16 port;
141 __u16 family;
142 __u8 proto;
143};
144
145struct vip_meta {
146 __u32 flags;
147 __u32 vip_num;
148};
149
150struct real_pos_lru {
151 __u32 pos;
152 __u64 atime;
153};
154
155struct real_definition {
156 union {
157 __be32 dst;
158 __be32 dstv6[4];
159 };
160 __u8 flags;
161};
162
163struct lb_stats {
164 __u64 v2;
165 __u64 v1;
166};
167
168struct {
169 __uint(type, BPF_MAP_TYPE_HASH);
170 __uint(max_entries, 512);
171 __type(key, struct vip_definition);
172 __type(value, struct vip_meta);
173} vip_map SEC(".maps");
174
175struct {
176 __uint(type, BPF_MAP_TYPE_LRU_HASH);
177 __uint(max_entries, 300);
178 __uint(map_flags, 1U << 1);
179 __type(key, struct flow_key);
180 __type(value, struct real_pos_lru);
181} lru_cache SEC(".maps");
182
183struct {
184 __uint(type, BPF_MAP_TYPE_ARRAY);
185 __uint(max_entries, 12 * 655);
186 __type(key, __u32);
187 __type(value, __u32);
188} ch_rings SEC(".maps");
189
190struct {
191 __uint(type, BPF_MAP_TYPE_ARRAY);
192 __uint(max_entries, 40);
193 __type(key, __u32);
194 __type(value, struct real_definition);
195} reals SEC(".maps");
196
197struct {
198 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
199 __uint(max_entries, 515);
200 __type(key, __u32);
201 __type(value, struct lb_stats);
202} stats SEC(".maps");
203
204struct {
205 __uint(type, BPF_MAP_TYPE_ARRAY);
206 __uint(max_entries, 16);
207 __type(key, __u32);
208 __type(value, struct ctl_value);
209} ctl_array SEC(".maps");
210
211struct eth_hdr {
212 unsigned char eth_dest[6];
213 unsigned char eth_source[6];
214 unsigned short eth_proto;
215};
216
217static __noinline __u64 calc_offset(bool is_ipv6, bool is_icmp)
218{
219 __u64 off = sizeof(struct eth_hdr);
220 if (is_ipv6) {
221 off += sizeof(struct ipv6hdr);
222 if (is_icmp)
223 off += sizeof(struct icmp6hdr) + sizeof(struct ipv6hdr);
224 } else {
225 off += sizeof(struct iphdr);
226 if (is_icmp)
227 off += sizeof(struct icmphdr) + sizeof(struct iphdr);
228 }
229 return off;
230}
231
232static __attribute__ ((noinline))
233bool parse_udp(void *data, void *data_end,
234 bool is_ipv6, struct packet_description *pckt)
235{
236
237 bool is_icmp = !((pckt->flags & (1 << 0)) == 0);
238 __u64 off = calc_offset(is_ipv6, is_icmp);
239 struct udphdr *udp;
240 udp = data + off;
241
242 if (udp + 1 > data_end)
243 return false;
244 if (!is_icmp) {
245 pckt->flow.port16[0] = udp->source;
246 pckt->flow.port16[1] = udp->dest;
247 } else {
248 pckt->flow.port16[0] = udp->dest;
249 pckt->flow.port16[1] = udp->source;
250 }
251 return true;
252}
253
254static __attribute__ ((noinline))
255bool parse_tcp(void *data, void *data_end,
256 bool is_ipv6, struct packet_description *pckt)
257{
258
259 bool is_icmp = !((pckt->flags & (1 << 0)) == 0);
260 __u64 off = calc_offset(is_ipv6, is_icmp);
261 struct tcphdr *tcp;
262
263 tcp = data + off;
264 if (tcp + 1 > data_end)
265 return false;
266 if (tcp->syn)
267 pckt->flags |= (1 << 1);
268 if (!is_icmp) {
269 pckt->flow.port16[0] = tcp->source;
270 pckt->flow.port16[1] = tcp->dest;
271 } else {
272 pckt->flow.port16[0] = tcp->dest;
273 pckt->flow.port16[1] = tcp->source;
274 }
275 return true;
276}
277
278static __attribute__ ((noinline))
279bool encap_v6(struct xdp_md *xdp, struct ctl_value *cval,
280 struct packet_description *pckt,
281 struct real_definition *dst, __u32 pkt_bytes)
282{
283 struct eth_hdr *new_eth;
284 struct eth_hdr *old_eth;
285 struct ipv6hdr *ip6h;
286 __u32 ip_suffix;
287 void *data_end;
288 void *data;
289
290 if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct ipv6hdr)))
291 return false;
292 data = (void *)(long)xdp->data;
293 data_end = (void *)(long)xdp->data_end;
294 new_eth = data;
295 ip6h = data + sizeof(struct eth_hdr);
296 old_eth = data + sizeof(struct ipv6hdr);
297 if (new_eth + 1 > data_end ||
298 old_eth + 1 > data_end || ip6h + 1 > data_end)
299 return false;
300 memcpy(new_eth->eth_dest, cval->mac, 6);
301 memcpy(new_eth->eth_source, old_eth->eth_dest, 6);
302 new_eth->eth_proto = 56710;
303 ip6h->version = 6;
304 ip6h->priority = 0;
305 memset(ip6h->flow_lbl, 0, sizeof(ip6h->flow_lbl));
306
307 ip6h->nexthdr = IPPROTO_IPV6;
308 ip_suffix = pckt->flow.srcv6[3] ^ pckt->flow.port16[0];
309 ip6h->payload_len =
310 bpf_htons(pkt_bytes + sizeof(struct ipv6hdr));
311 ip6h->hop_limit = 4;
312
313 ip6h->saddr.in6_u.u6_addr32[0] = 1;
314 ip6h->saddr.in6_u.u6_addr32[1] = 2;
315 ip6h->saddr.in6_u.u6_addr32[2] = 3;
316 ip6h->saddr.in6_u.u6_addr32[3] = ip_suffix;
317 memcpy(ip6h->daddr.in6_u.u6_addr32, dst->dstv6, 16);
318 return true;
319}
320
321#ifndef __clang__
322#pragma GCC push_options
323/* GCC optimization collapses functions and increases the number of arguments
324 * beyond the compatible amount supported by BPF.
325 */
326#pragma GCC optimize("-fno-ipa-sra")
327#endif
328
329static __attribute__ ((noinline))
330bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval,
331 struct packet_description *pckt,
332 struct real_definition *dst, __u32 pkt_bytes)
333{
334
335 __u32 ip_suffix = bpf_ntohs(pckt->flow.port16[0]);
336 struct eth_hdr *new_eth;
337 struct eth_hdr *old_eth;
338 __u16 *next_iph_u16;
339 struct iphdr *iph;
340 __u32 csum = 0;
341 void *data_end;
342 void *data;
343
344 ip_suffix <<= 15;
345 ip_suffix ^= pckt->flow.src;
346 if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct iphdr)))
347 return false;
348 data = (void *)(long)xdp->data;
349 data_end = (void *)(long)xdp->data_end;
350 new_eth = data;
351 iph = data + sizeof(struct eth_hdr);
352 old_eth = data + sizeof(struct iphdr);
353 if (new_eth + 1 > data_end ||
354 old_eth + 1 > data_end || iph + 1 > data_end)
355 return false;
356 memcpy(new_eth->eth_dest, cval->mac, 6);
357 memcpy(new_eth->eth_source, old_eth->eth_dest, 6);
358 new_eth->eth_proto = 8;
359 iph->version = 4;
360 iph->ihl = 5;
361 iph->frag_off = 0;
362 iph->protocol = IPPROTO_IPIP;
363 iph->check = 0;
364 iph->tos = 1;
365 iph->tot_len = bpf_htons(pkt_bytes + sizeof(struct iphdr));
366 /* don't update iph->daddr, since it will overwrite old eth_proto
367 * and multiple iterations of bpf_prog_run() will fail
368 */
369
370 iph->saddr = ((0xFFFF0000 & ip_suffix) | 4268) ^ dst->dst;
371 iph->ttl = 4;
372
373 next_iph_u16 = (__u16 *) iph;
374 __pragma_loop_unroll_full
375 for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
376 csum += *next_iph_u16++;
377 iph->check = ~((csum & 0xffff) + (csum >> 16));
378 if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr)))
379 return false;
380 return true;
381}
382
383#ifndef __clang__
384#pragma GCC pop_options
385#endif
386
387static __attribute__ ((noinline))
388int swap_mac_and_send(void *data, void *data_end)
389{
390 unsigned char tmp_mac[6];
391 struct eth_hdr *eth;
392
393 eth = data;
394 memcpy(tmp_mac, eth->eth_source, 6);
395 memcpy(eth->eth_source, eth->eth_dest, 6);
396 memcpy(eth->eth_dest, tmp_mac, 6);
397 return XDP_TX;
398}
399
400static __attribute__ ((noinline))
401int send_icmp_reply(void *data, void *data_end)
402{
403 struct icmphdr *icmp_hdr;
404 __u16 *next_iph_u16;
405 __u32 tmp_addr = 0;
406 struct iphdr *iph;
407 __u32 csum = 0;
408 __u64 off = 0;
409
410 if (data + sizeof(struct eth_hdr)
411 + sizeof(struct iphdr) + sizeof(struct icmphdr) > data_end)
412 return XDP_DROP;
413 off += sizeof(struct eth_hdr);
414 iph = data + off;
415 off += sizeof(struct iphdr);
416 icmp_hdr = data + off;
417 icmp_hdr->type = 0;
418 icmp_hdr->checksum += 0x0007;
419 iph->ttl = 4;
420 tmp_addr = iph->daddr;
421 iph->daddr = iph->saddr;
422 iph->saddr = tmp_addr;
423 iph->check = 0;
424 next_iph_u16 = (__u16 *) iph;
425 __pragma_loop_unroll_full
426 for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
427 csum += *next_iph_u16++;
428 iph->check = ~((csum & 0xffff) + (csum >> 16));
429 return swap_mac_and_send(data, data_end);
430}
431
432static __attribute__ ((noinline))
433int send_icmp6_reply(void *data, void *data_end)
434{
435 struct icmp6hdr *icmp_hdr;
436 struct ipv6hdr *ip6h;
437 __be32 tmp_addr[4];
438 __u64 off = 0;
439
440 if (data + sizeof(struct eth_hdr)
441 + sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr) > data_end)
442 return XDP_DROP;
443 off += sizeof(struct eth_hdr);
444 ip6h = data + off;
445 off += sizeof(struct ipv6hdr);
446 icmp_hdr = data + off;
447 icmp_hdr->icmp6_type = 129;
448 icmp_hdr->icmp6_cksum -= 0x0001;
449 ip6h->hop_limit = 4;
450 memcpy(tmp_addr, ip6h->saddr.in6_u.u6_addr32, 16);
451 memcpy(ip6h->saddr.in6_u.u6_addr32, ip6h->daddr.in6_u.u6_addr32, 16);
452 memcpy(ip6h->daddr.in6_u.u6_addr32, tmp_addr, 16);
453 return swap_mac_and_send(data, data_end);
454}
455
456static __attribute__ ((noinline))
457int parse_icmpv6(void *data, void *data_end, __u64 off,
458 struct packet_description *pckt)
459{
460 struct icmp6hdr *icmp_hdr;
461 struct ipv6hdr *ip6h;
462
463 icmp_hdr = data + off;
464 if (icmp_hdr + 1 > data_end)
465 return XDP_DROP;
466 if (icmp_hdr->icmp6_type == 128)
467 return send_icmp6_reply(data, data_end);
468 if (icmp_hdr->icmp6_type != 3)
469 return XDP_PASS;
470 off += sizeof(struct icmp6hdr);
471 ip6h = data + off;
472 if (ip6h + 1 > data_end)
473 return XDP_DROP;
474 pckt->flow.proto = ip6h->nexthdr;
475 pckt->flags |= (1 << 0);
476 memcpy(pckt->flow.srcv6, ip6h->daddr.in6_u.u6_addr32, 16);
477 memcpy(pckt->flow.dstv6, ip6h->saddr.in6_u.u6_addr32, 16);
478 return -1;
479}
480
481static __attribute__ ((noinline))
482int parse_icmp(void *data, void *data_end, __u64 off,
483 struct packet_description *pckt)
484{
485 struct icmphdr *icmp_hdr;
486 struct iphdr *iph;
487
488 icmp_hdr = data + off;
489 if (icmp_hdr + 1 > data_end)
490 return XDP_DROP;
491 if (icmp_hdr->type == 8)
492 return send_icmp_reply(data, data_end);
493 if ((icmp_hdr->type != 3) || (icmp_hdr->code != 4))
494 return XDP_PASS;
495 off += sizeof(struct icmphdr);
496 iph = data + off;
497 if (iph + 1 > data_end)
498 return XDP_DROP;
499 if (iph->ihl != 5)
500 return XDP_DROP;
501 pckt->flow.proto = iph->protocol;
502 pckt->flags |= (1 << 0);
503 pckt->flow.src = iph->daddr;
504 pckt->flow.dst = iph->saddr;
505 return -1;
506}
507
508static __attribute__ ((noinline))
509__u32 get_packet_hash(struct packet_description *pckt,
510 bool hash_16bytes)
511{
512 if (hash_16bytes)
513 return jhash_2words(jhash(pckt->flow.srcv6, 16, 12),
514 pckt->flow.ports, 24);
515 else
516 return jhash_2words(pckt->flow.src, pckt->flow.ports,
517 24);
518}
519
520__attribute__ ((noinline))
521static bool get_packet_dst(struct real_definition **real,
522 struct packet_description *pckt,
523 struct vip_meta *vip_info,
524 bool is_ipv6, void *lru_map)
525{
526 struct real_pos_lru new_dst_lru = { };
527 bool hash_16bytes = is_ipv6;
528 __u32 *real_pos, hash, key;
529 __u64 cur_time;
530
531 if (vip_info->flags & (1 << 2))
532 hash_16bytes = 1;
533 if (vip_info->flags & (1 << 3)) {
534 pckt->flow.port16[0] = pckt->flow.port16[1];
535 memset(pckt->flow.srcv6, 0, 16);
536 }
537 hash = get_packet_hash(pckt, hash_16bytes);
538 if (hash != 0x358459b7 /* jhash of ipv4 packet */ &&
539 hash != 0x2f4bc6bb /* jhash of ipv6 packet */)
540 return false;
541 key = 2 * vip_info->vip_num + hash % 2;
542 real_pos = bpf_map_lookup_elem(&ch_rings, &key);
543 if (!real_pos)
544 return false;
545 key = *real_pos;
546 *real = bpf_map_lookup_elem(&reals, &key);
547 if (!(*real))
548 return false;
549 if (!(vip_info->flags & (1 << 1))) {
550 __u32 conn_rate_key = 512 + 2;
551 struct lb_stats *conn_rate_stats =
552 bpf_map_lookup_elem(&stats, &conn_rate_key);
553
554 if (!conn_rate_stats)
555 return true;
556 cur_time = bpf_ktime_get_ns();
557 if ((cur_time - conn_rate_stats->v2) >> 32 > 0xffFFFF) {
558 conn_rate_stats->v1 = 1;
559 conn_rate_stats->v2 = cur_time;
560 } else {
561 conn_rate_stats->v1 += 1;
562 if (conn_rate_stats->v1 >= 1)
563 return true;
564 }
565 if (pckt->flow.proto == IPPROTO_UDP)
566 new_dst_lru.atime = cur_time;
567 new_dst_lru.pos = key;
568 bpf_map_update_elem(lru_map, &pckt->flow, &new_dst_lru, 0);
569 }
570 return true;
571}
572
573__attribute__ ((noinline))
574static void connection_table_lookup(struct real_definition **real,
575 struct packet_description *pckt,
576 void *lru_map)
577{
578
579 struct real_pos_lru *dst_lru;
580 __u64 cur_time;
581 __u32 key;
582
583 dst_lru = bpf_map_lookup_elem(lru_map, &pckt->flow);
584 if (!dst_lru)
585 return;
586 if (pckt->flow.proto == IPPROTO_UDP) {
587 cur_time = bpf_ktime_get_ns();
588 if (cur_time - dst_lru->atime > 300000)
589 return;
590 dst_lru->atime = cur_time;
591 }
592 key = dst_lru->pos;
593 *real = bpf_map_lookup_elem(&reals, &key);
594}
595
596/* don't believe your eyes!
597 * below function has 6 arguments whereas bpf and llvm allow maximum of 5
598 * but since it's _static_ llvm can optimize one argument away
599 */
600__attribute__ ((noinline))
601static int process_l3_headers_v6(struct packet_description *pckt,
602 __u8 *protocol, __u64 off,
603 __u16 *pkt_bytes, void *extra_args[2])
604{
605 struct ipv6hdr *ip6h;
606 __u64 iph_len;
607 int action;
608 void *data = extra_args[0];
609 void *data_end = extra_args[1];
610
611 ip6h = data + off;
612 if (ip6h + 1 > data_end)
613 return XDP_DROP;
614 iph_len = sizeof(struct ipv6hdr);
615 *protocol = ip6h->nexthdr;
616 pckt->flow.proto = *protocol;
617 *pkt_bytes = bpf_ntohs(ip6h->payload_len);
618 off += iph_len;
619 if (*protocol == 45) {
620 return XDP_DROP;
621 } else if (*protocol == 59) {
622 action = parse_icmpv6(data, data_end, off, pckt);
623 if (action >= 0)
624 return action;
625 } else {
626 memcpy(pckt->flow.srcv6, ip6h->saddr.in6_u.u6_addr32, 16);
627 memcpy(pckt->flow.dstv6, ip6h->daddr.in6_u.u6_addr32, 16);
628 }
629 return -1;
630}
631
632__attribute__ ((noinline))
633static int process_l3_headers_v4(struct packet_description *pckt,
634 __u8 *protocol, __u64 off,
635 __u16 *pkt_bytes, void *extra_args[2])
636{
637 struct iphdr *iph;
638 int action;
639 void *data = extra_args[0];
640 void *data_end = extra_args[1];
641
642 iph = data + off;
643 if (iph + 1 > data_end)
644 return XDP_DROP;
645 if (iph->ihl != 5)
646 return XDP_DROP;
647 *protocol = iph->protocol;
648 pckt->flow.proto = *protocol;
649 *pkt_bytes = bpf_ntohs(iph->tot_len);
650 off += 20;
651 if (iph->frag_off & 65343)
652 return XDP_DROP;
653 if (*protocol == IPPROTO_ICMP) {
654 action = parse_icmp(data, data_end, off, pckt);
655 if (action >= 0)
656 return action;
657 } else {
658 pckt->flow.src = iph->saddr;
659 pckt->flow.dst = iph->daddr;
660 }
661 return -1;
662}
663
664__attribute__ ((noinline))
665static int process_packet(void *data, __u64 off, void *data_end,
666 bool is_ipv6, struct xdp_md *xdp)
667{
668
669 struct real_definition *dst = NULL;
670 struct packet_description pckt = { };
671 struct vip_definition vip = { };
672 struct lb_stats *data_stats;
673 void *lru_map = &lru_cache;
674 struct vip_meta *vip_info;
675 __u32 lru_stats_key = 513;
676 __u32 mac_addr_pos = 0;
677 __u32 stats_key = 512;
678 struct ctl_value *cval;
679 __u16 pkt_bytes;
680 __u8 protocol;
681 __u32 vip_num;
682 int action;
683 void *extra_args[2] = { data, data_end };
684
685 if (is_ipv6)
686 action = process_l3_headers_v6(&pckt, &protocol, off,
687 &pkt_bytes, extra_args);
688 else
689 action = process_l3_headers_v4(&pckt, &protocol, off,
690 &pkt_bytes, extra_args);
691 if (action >= 0)
692 return action;
693 protocol = pckt.flow.proto;
694 if (protocol == IPPROTO_TCP) {
695 if (!parse_tcp(data, data_end, is_ipv6, &pckt))
696 return XDP_DROP;
697 } else if (protocol == IPPROTO_UDP) {
698 if (!parse_udp(data, data_end, is_ipv6, &pckt))
699 return XDP_DROP;
700 } else {
701 return XDP_TX;
702 }
703
704 if (is_ipv6)
705 memcpy(vip.vipv6, pckt.flow.dstv6, 16);
706 else
707 vip.vip = pckt.flow.dst;
708 vip.port = pckt.flow.port16[1];
709 vip.proto = pckt.flow.proto;
710 vip_info = bpf_map_lookup_elem(&vip_map, &vip);
711 if (!vip_info) {
712 vip.port = 0;
713 vip_info = bpf_map_lookup_elem(&vip_map, &vip);
714 if (!vip_info)
715 return XDP_PASS;
716 if (!(vip_info->flags & (1 << 4)))
717 pckt.flow.port16[1] = 0;
718 }
719 if (data_end - data > 1400)
720 return XDP_DROP;
721 data_stats = bpf_map_lookup_elem(&stats, &stats_key);
722 if (!data_stats)
723 return XDP_DROP;
724 data_stats->v1 += 1;
725 if (!dst) {
726 if (vip_info->flags & (1 << 0))
727 pckt.flow.port16[0] = 0;
728 if (!(pckt.flags & (1 << 1)) && !(vip_info->flags & (1 << 1)))
729 connection_table_lookup(&dst, &pckt, lru_map);
730 if (dst)
731 goto out;
732 if (pckt.flow.proto == IPPROTO_TCP) {
733 struct lb_stats *lru_stats =
734 bpf_map_lookup_elem(&stats, &lru_stats_key);
735
736 if (!lru_stats)
737 return XDP_DROP;
738 if (pckt.flags & (1 << 1))
739 lru_stats->v1 += 1;
740 else
741 lru_stats->v2 += 1;
742 }
743 if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6, lru_map))
744 return XDP_DROP;
745 data_stats->v2 += 1;
746 }
747out:
748 cval = bpf_map_lookup_elem(&ctl_array, &mac_addr_pos);
749 if (!cval)
750 return XDP_DROP;
751 if (dst->flags & (1 << 0)) {
752 if (!encap_v6(xdp, cval, &pckt, dst, pkt_bytes))
753 return XDP_DROP;
754 } else {
755 if (!encap_v4(xdp, cval, &pckt, dst, pkt_bytes))
756 return XDP_DROP;
757 }
758 vip_num = vip_info->vip_num;
759 data_stats = bpf_map_lookup_elem(&stats, &vip_num);
760 if (!data_stats)
761 return XDP_DROP;
762 data_stats->v1 += 1;
763 data_stats->v2 += pkt_bytes;
764
765 data = (void *)(long)xdp->data;
766 data_end = (void *)(long)xdp->data_end;
767 if (data + 4 > data_end)
768 return XDP_DROP;
769 *(u32 *)data = dst->dst;
770 return XDP_DROP;
771}
772
773SEC("xdp")
774int balancer_ingress_v4(struct xdp_md *ctx)
775{
776 void *data = (void *)(long)ctx->data;
777 void *data_end = (void *)(long)ctx->data_end;
778 struct eth_hdr *eth = data;
779 __u32 eth_proto;
780 __u32 nh_off;
781
782 nh_off = sizeof(struct eth_hdr);
783 if (data + nh_off > data_end)
784 return XDP_DROP;
785 eth_proto = bpf_ntohs(eth->eth_proto);
786 if (eth_proto == ETH_P_IP)
787 return process_packet(data, nh_off, data_end, 0, ctx);
788 else
789 return XDP_DROP;
790}
791
792SEC("xdp")
793int balancer_ingress_v6(struct xdp_md *ctx)
794{
795 void *data = (void *)(long)ctx->data;
796 void *data_end = (void *)(long)ctx->data_end;
797 struct eth_hdr *eth = data;
798 __u32 eth_proto;
799 __u32 nh_off;
800
801 nh_off = sizeof(struct eth_hdr);
802 if (data + nh_off > data_end)
803 return XDP_DROP;
804 eth_proto = bpf_ntohs(eth->eth_proto);
805 if (eth_proto == ETH_P_IPV6)
806 return process_packet(data, nh_off, data_end, 1, ctx);
807 else
808 return XDP_DROP;
809}
810
811char _license[] SEC("license") = "GPL";
1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2017 Facebook
3#include <stddef.h>
4#include <stdbool.h>
5#include <string.h>
6#include <linux/pkt_cls.h>
7#include <linux/bpf.h>
8#include <linux/in.h>
9#include <linux/if_ether.h>
10#include <linux/ip.h>
11#include <linux/ipv6.h>
12#include <linux/icmp.h>
13#include <linux/icmpv6.h>
14#include <linux/tcp.h>
15#include <linux/udp.h>
16#include <bpf/bpf_helpers.h>
17#include <bpf/bpf_endian.h>
18
19static __always_inline __u32 rol32(__u32 word, unsigned int shift)
20{
21 return (word << shift) | (word >> ((-shift) & 31));
22}
23
24/* copy paste of jhash from kernel sources to make sure llvm
25 * can compile it into valid sequence of bpf instructions
26 */
27#define __jhash_mix(a, b, c) \
28{ \
29 a -= c; a ^= rol32(c, 4); c += b; \
30 b -= a; b ^= rol32(a, 6); a += c; \
31 c -= b; c ^= rol32(b, 8); b += a; \
32 a -= c; a ^= rol32(c, 16); c += b; \
33 b -= a; b ^= rol32(a, 19); a += c; \
34 c -= b; c ^= rol32(b, 4); b += a; \
35}
36
37#define __jhash_final(a, b, c) \
38{ \
39 c ^= b; c -= rol32(b, 14); \
40 a ^= c; a -= rol32(c, 11); \
41 b ^= a; b -= rol32(a, 25); \
42 c ^= b; c -= rol32(b, 16); \
43 a ^= c; a -= rol32(c, 4); \
44 b ^= a; b -= rol32(a, 14); \
45 c ^= b; c -= rol32(b, 24); \
46}
47
48#define JHASH_INITVAL 0xdeadbeef
49
50typedef unsigned int u32;
51
52static __noinline
53u32 jhash(const void *key, u32 length, u32 initval)
54{
55 u32 a, b, c;
56 const unsigned char *k = key;
57
58 a = b = c = JHASH_INITVAL + length + initval;
59
60 while (length > 12) {
61 a += *(u32 *)(k);
62 b += *(u32 *)(k + 4);
63 c += *(u32 *)(k + 8);
64 __jhash_mix(a, b, c);
65 length -= 12;
66 k += 12;
67 }
68 switch (length) {
69 case 12: c += (u32)k[11]<<24;
70 case 11: c += (u32)k[10]<<16;
71 case 10: c += (u32)k[9]<<8;
72 case 9: c += k[8];
73 case 8: b += (u32)k[7]<<24;
74 case 7: b += (u32)k[6]<<16;
75 case 6: b += (u32)k[5]<<8;
76 case 5: b += k[4];
77 case 4: a += (u32)k[3]<<24;
78 case 3: a += (u32)k[2]<<16;
79 case 2: a += (u32)k[1]<<8;
80 case 1: a += k[0];
81 __jhash_final(a, b, c);
82 case 0: /* Nothing left to add */
83 break;
84 }
85
86 return c;
87}
88
89__noinline
90u32 __jhash_nwords(u32 a, u32 b, u32 c, u32 initval)
91{
92 a += initval;
93 b += initval;
94 c += initval;
95 __jhash_final(a, b, c);
96 return c;
97}
98
99__noinline
100u32 jhash_2words(u32 a, u32 b, u32 initval)
101{
102 return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
103}
104
105struct flow_key {
106 union {
107 __be32 src;
108 __be32 srcv6[4];
109 };
110 union {
111 __be32 dst;
112 __be32 dstv6[4];
113 };
114 union {
115 __u32 ports;
116 __u16 port16[2];
117 };
118 __u8 proto;
119};
120
121struct packet_description {
122 struct flow_key flow;
123 __u8 flags;
124};
125
126struct ctl_value {
127 union {
128 __u64 value;
129 __u32 ifindex;
130 __u8 mac[6];
131 };
132};
133
134struct vip_definition {
135 union {
136 __be32 vip;
137 __be32 vipv6[4];
138 };
139 __u16 port;
140 __u16 family;
141 __u8 proto;
142};
143
144struct vip_meta {
145 __u32 flags;
146 __u32 vip_num;
147};
148
149struct real_pos_lru {
150 __u32 pos;
151 __u64 atime;
152};
153
154struct real_definition {
155 union {
156 __be32 dst;
157 __be32 dstv6[4];
158 };
159 __u8 flags;
160};
161
162struct lb_stats {
163 __u64 v2;
164 __u64 v1;
165};
166
167struct {
168 __uint(type, BPF_MAP_TYPE_HASH);
169 __uint(max_entries, 512);
170 __type(key, struct vip_definition);
171 __type(value, struct vip_meta);
172} vip_map SEC(".maps");
173
174struct {
175 __uint(type, BPF_MAP_TYPE_LRU_HASH);
176 __uint(max_entries, 300);
177 __uint(map_flags, 1U << 1);
178 __type(key, struct flow_key);
179 __type(value, struct real_pos_lru);
180} lru_cache SEC(".maps");
181
182struct {
183 __uint(type, BPF_MAP_TYPE_ARRAY);
184 __uint(max_entries, 12 * 655);
185 __type(key, __u32);
186 __type(value, __u32);
187} ch_rings SEC(".maps");
188
189struct {
190 __uint(type, BPF_MAP_TYPE_ARRAY);
191 __uint(max_entries, 40);
192 __type(key, __u32);
193 __type(value, struct real_definition);
194} reals SEC(".maps");
195
196struct {
197 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
198 __uint(max_entries, 515);
199 __type(key, __u32);
200 __type(value, struct lb_stats);
201} stats SEC(".maps");
202
203struct {
204 __uint(type, BPF_MAP_TYPE_ARRAY);
205 __uint(max_entries, 16);
206 __type(key, __u32);
207 __type(value, struct ctl_value);
208} ctl_array SEC(".maps");
209
210struct eth_hdr {
211 unsigned char eth_dest[6];
212 unsigned char eth_source[6];
213 unsigned short eth_proto;
214};
215
216static __noinline __u64 calc_offset(bool is_ipv6, bool is_icmp)
217{
218 __u64 off = sizeof(struct eth_hdr);
219 if (is_ipv6) {
220 off += sizeof(struct ipv6hdr);
221 if (is_icmp)
222 off += sizeof(struct icmp6hdr) + sizeof(struct ipv6hdr);
223 } else {
224 off += sizeof(struct iphdr);
225 if (is_icmp)
226 off += sizeof(struct icmphdr) + sizeof(struct iphdr);
227 }
228 return off;
229}
230
231static __attribute__ ((noinline))
232bool parse_udp(void *data, void *data_end,
233 bool is_ipv6, struct packet_description *pckt)
234{
235
236 bool is_icmp = !((pckt->flags & (1 << 0)) == 0);
237 __u64 off = calc_offset(is_ipv6, is_icmp);
238 struct udphdr *udp;
239 udp = data + off;
240
241 if (udp + 1 > data_end)
242 return false;
243 if (!is_icmp) {
244 pckt->flow.port16[0] = udp->source;
245 pckt->flow.port16[1] = udp->dest;
246 } else {
247 pckt->flow.port16[0] = udp->dest;
248 pckt->flow.port16[1] = udp->source;
249 }
250 return true;
251}
252
253static __attribute__ ((noinline))
254bool parse_tcp(void *data, void *data_end,
255 bool is_ipv6, struct packet_description *pckt)
256{
257
258 bool is_icmp = !((pckt->flags & (1 << 0)) == 0);
259 __u64 off = calc_offset(is_ipv6, is_icmp);
260 struct tcphdr *tcp;
261
262 tcp = data + off;
263 if (tcp + 1 > data_end)
264 return false;
265 if (tcp->syn)
266 pckt->flags |= (1 << 1);
267 if (!is_icmp) {
268 pckt->flow.port16[0] = tcp->source;
269 pckt->flow.port16[1] = tcp->dest;
270 } else {
271 pckt->flow.port16[0] = tcp->dest;
272 pckt->flow.port16[1] = tcp->source;
273 }
274 return true;
275}
276
277static __attribute__ ((noinline))
278bool encap_v6(struct xdp_md *xdp, struct ctl_value *cval,
279 struct packet_description *pckt,
280 struct real_definition *dst, __u32 pkt_bytes)
281{
282 struct eth_hdr *new_eth;
283 struct eth_hdr *old_eth;
284 struct ipv6hdr *ip6h;
285 __u32 ip_suffix;
286 void *data_end;
287 void *data;
288
289 if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct ipv6hdr)))
290 return false;
291 data = (void *)(long)xdp->data;
292 data_end = (void *)(long)xdp->data_end;
293 new_eth = data;
294 ip6h = data + sizeof(struct eth_hdr);
295 old_eth = data + sizeof(struct ipv6hdr);
296 if (new_eth + 1 > data_end ||
297 old_eth + 1 > data_end || ip6h + 1 > data_end)
298 return false;
299 memcpy(new_eth->eth_dest, cval->mac, 6);
300 memcpy(new_eth->eth_source, old_eth->eth_dest, 6);
301 new_eth->eth_proto = 56710;
302 ip6h->version = 6;
303 ip6h->priority = 0;
304 memset(ip6h->flow_lbl, 0, sizeof(ip6h->flow_lbl));
305
306 ip6h->nexthdr = IPPROTO_IPV6;
307 ip_suffix = pckt->flow.srcv6[3] ^ pckt->flow.port16[0];
308 ip6h->payload_len =
309 bpf_htons(pkt_bytes + sizeof(struct ipv6hdr));
310 ip6h->hop_limit = 4;
311
312 ip6h->saddr.in6_u.u6_addr32[0] = 1;
313 ip6h->saddr.in6_u.u6_addr32[1] = 2;
314 ip6h->saddr.in6_u.u6_addr32[2] = 3;
315 ip6h->saddr.in6_u.u6_addr32[3] = ip_suffix;
316 memcpy(ip6h->daddr.in6_u.u6_addr32, dst->dstv6, 16);
317 return true;
318}
319
320static __attribute__ ((noinline))
321bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval,
322 struct packet_description *pckt,
323 struct real_definition *dst, __u32 pkt_bytes)
324{
325
326 __u32 ip_suffix = bpf_ntohs(pckt->flow.port16[0]);
327 struct eth_hdr *new_eth;
328 struct eth_hdr *old_eth;
329 __u16 *next_iph_u16;
330 struct iphdr *iph;
331 __u32 csum = 0;
332 void *data_end;
333 void *data;
334
335 ip_suffix <<= 15;
336 ip_suffix ^= pckt->flow.src;
337 if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct iphdr)))
338 return false;
339 data = (void *)(long)xdp->data;
340 data_end = (void *)(long)xdp->data_end;
341 new_eth = data;
342 iph = data + sizeof(struct eth_hdr);
343 old_eth = data + sizeof(struct iphdr);
344 if (new_eth + 1 > data_end ||
345 old_eth + 1 > data_end || iph + 1 > data_end)
346 return false;
347 memcpy(new_eth->eth_dest, cval->mac, 6);
348 memcpy(new_eth->eth_source, old_eth->eth_dest, 6);
349 new_eth->eth_proto = 8;
350 iph->version = 4;
351 iph->ihl = 5;
352 iph->frag_off = 0;
353 iph->protocol = IPPROTO_IPIP;
354 iph->check = 0;
355 iph->tos = 1;
356 iph->tot_len = bpf_htons(pkt_bytes + sizeof(struct iphdr));
357 /* don't update iph->daddr, since it will overwrite old eth_proto
358 * and multiple iterations of bpf_prog_run() will fail
359 */
360
361 iph->saddr = ((0xFFFF0000 & ip_suffix) | 4268) ^ dst->dst;
362 iph->ttl = 4;
363
364 next_iph_u16 = (__u16 *) iph;
365#pragma clang loop unroll(full)
366 for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
367 csum += *next_iph_u16++;
368 iph->check = ~((csum & 0xffff) + (csum >> 16));
369 if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr)))
370 return false;
371 return true;
372}
373
374static __attribute__ ((noinline))
375bool decap_v6(struct xdp_md *xdp, void **data, void **data_end, bool inner_v4)
376{
377 struct eth_hdr *new_eth;
378 struct eth_hdr *old_eth;
379
380 old_eth = *data;
381 new_eth = *data + sizeof(struct ipv6hdr);
382 memcpy(new_eth->eth_source, old_eth->eth_source, 6);
383 memcpy(new_eth->eth_dest, old_eth->eth_dest, 6);
384 if (inner_v4)
385 new_eth->eth_proto = 8;
386 else
387 new_eth->eth_proto = 56710;
388 if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct ipv6hdr)))
389 return false;
390 *data = (void *)(long)xdp->data;
391 *data_end = (void *)(long)xdp->data_end;
392 return true;
393}
394
395static __attribute__ ((noinline))
396bool decap_v4(struct xdp_md *xdp, void **data, void **data_end)
397{
398 struct eth_hdr *new_eth;
399 struct eth_hdr *old_eth;
400
401 old_eth = *data;
402 new_eth = *data + sizeof(struct iphdr);
403 memcpy(new_eth->eth_source, old_eth->eth_source, 6);
404 memcpy(new_eth->eth_dest, old_eth->eth_dest, 6);
405 new_eth->eth_proto = 8;
406 if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr)))
407 return false;
408 *data = (void *)(long)xdp->data;
409 *data_end = (void *)(long)xdp->data_end;
410 return true;
411}
412
413static __attribute__ ((noinline))
414int swap_mac_and_send(void *data, void *data_end)
415{
416 unsigned char tmp_mac[6];
417 struct eth_hdr *eth;
418
419 eth = data;
420 memcpy(tmp_mac, eth->eth_source, 6);
421 memcpy(eth->eth_source, eth->eth_dest, 6);
422 memcpy(eth->eth_dest, tmp_mac, 6);
423 return XDP_TX;
424}
425
426static __attribute__ ((noinline))
427int send_icmp_reply(void *data, void *data_end)
428{
429 struct icmphdr *icmp_hdr;
430 __u16 *next_iph_u16;
431 __u32 tmp_addr = 0;
432 struct iphdr *iph;
433 __u32 csum1 = 0;
434 __u32 csum = 0;
435 __u64 off = 0;
436
437 if (data + sizeof(struct eth_hdr)
438 + sizeof(struct iphdr) + sizeof(struct icmphdr) > data_end)
439 return XDP_DROP;
440 off += sizeof(struct eth_hdr);
441 iph = data + off;
442 off += sizeof(struct iphdr);
443 icmp_hdr = data + off;
444 icmp_hdr->type = 0;
445 icmp_hdr->checksum += 0x0007;
446 iph->ttl = 4;
447 tmp_addr = iph->daddr;
448 iph->daddr = iph->saddr;
449 iph->saddr = tmp_addr;
450 iph->check = 0;
451 next_iph_u16 = (__u16 *) iph;
452#pragma clang loop unroll(full)
453 for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
454 csum += *next_iph_u16++;
455 iph->check = ~((csum & 0xffff) + (csum >> 16));
456 return swap_mac_and_send(data, data_end);
457}
458
459static __attribute__ ((noinline))
460int send_icmp6_reply(void *data, void *data_end)
461{
462 struct icmp6hdr *icmp_hdr;
463 struct ipv6hdr *ip6h;
464 __be32 tmp_addr[4];
465 __u64 off = 0;
466
467 if (data + sizeof(struct eth_hdr)
468 + sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr) > data_end)
469 return XDP_DROP;
470 off += sizeof(struct eth_hdr);
471 ip6h = data + off;
472 off += sizeof(struct ipv6hdr);
473 icmp_hdr = data + off;
474 icmp_hdr->icmp6_type = 129;
475 icmp_hdr->icmp6_cksum -= 0x0001;
476 ip6h->hop_limit = 4;
477 memcpy(tmp_addr, ip6h->saddr.in6_u.u6_addr32, 16);
478 memcpy(ip6h->saddr.in6_u.u6_addr32, ip6h->daddr.in6_u.u6_addr32, 16);
479 memcpy(ip6h->daddr.in6_u.u6_addr32, tmp_addr, 16);
480 return swap_mac_and_send(data, data_end);
481}
482
483static __attribute__ ((noinline))
484int parse_icmpv6(void *data, void *data_end, __u64 off,
485 struct packet_description *pckt)
486{
487 struct icmp6hdr *icmp_hdr;
488 struct ipv6hdr *ip6h;
489
490 icmp_hdr = data + off;
491 if (icmp_hdr + 1 > data_end)
492 return XDP_DROP;
493 if (icmp_hdr->icmp6_type == 128)
494 return send_icmp6_reply(data, data_end);
495 if (icmp_hdr->icmp6_type != 3)
496 return XDP_PASS;
497 off += sizeof(struct icmp6hdr);
498 ip6h = data + off;
499 if (ip6h + 1 > data_end)
500 return XDP_DROP;
501 pckt->flow.proto = ip6h->nexthdr;
502 pckt->flags |= (1 << 0);
503 memcpy(pckt->flow.srcv6, ip6h->daddr.in6_u.u6_addr32, 16);
504 memcpy(pckt->flow.dstv6, ip6h->saddr.in6_u.u6_addr32, 16);
505 return -1;
506}
507
508static __attribute__ ((noinline))
509int parse_icmp(void *data, void *data_end, __u64 off,
510 struct packet_description *pckt)
511{
512 struct icmphdr *icmp_hdr;
513 struct iphdr *iph;
514
515 icmp_hdr = data + off;
516 if (icmp_hdr + 1 > data_end)
517 return XDP_DROP;
518 if (icmp_hdr->type == 8)
519 return send_icmp_reply(data, data_end);
520 if ((icmp_hdr->type != 3) || (icmp_hdr->code != 4))
521 return XDP_PASS;
522 off += sizeof(struct icmphdr);
523 iph = data + off;
524 if (iph + 1 > data_end)
525 return XDP_DROP;
526 if (iph->ihl != 5)
527 return XDP_DROP;
528 pckt->flow.proto = iph->protocol;
529 pckt->flags |= (1 << 0);
530 pckt->flow.src = iph->daddr;
531 pckt->flow.dst = iph->saddr;
532 return -1;
533}
534
535static __attribute__ ((noinline))
536__u32 get_packet_hash(struct packet_description *pckt,
537 bool hash_16bytes)
538{
539 if (hash_16bytes)
540 return jhash_2words(jhash(pckt->flow.srcv6, 16, 12),
541 pckt->flow.ports, 24);
542 else
543 return jhash_2words(pckt->flow.src, pckt->flow.ports,
544 24);
545}
546
547__attribute__ ((noinline))
548static bool get_packet_dst(struct real_definition **real,
549 struct packet_description *pckt,
550 struct vip_meta *vip_info,
551 bool is_ipv6, void *lru_map)
552{
553 struct real_pos_lru new_dst_lru = { };
554 bool hash_16bytes = is_ipv6;
555 __u32 *real_pos, hash, key;
556 __u64 cur_time;
557
558 if (vip_info->flags & (1 << 2))
559 hash_16bytes = 1;
560 if (vip_info->flags & (1 << 3)) {
561 pckt->flow.port16[0] = pckt->flow.port16[1];
562 memset(pckt->flow.srcv6, 0, 16);
563 }
564 hash = get_packet_hash(pckt, hash_16bytes);
565 if (hash != 0x358459b7 /* jhash of ipv4 packet */ &&
566 hash != 0x2f4bc6bb /* jhash of ipv6 packet */)
567 return false;
568 key = 2 * vip_info->vip_num + hash % 2;
569 real_pos = bpf_map_lookup_elem(&ch_rings, &key);
570 if (!real_pos)
571 return false;
572 key = *real_pos;
573 *real = bpf_map_lookup_elem(&reals, &key);
574 if (!(*real))
575 return false;
576 if (!(vip_info->flags & (1 << 1))) {
577 __u32 conn_rate_key = 512 + 2;
578 struct lb_stats *conn_rate_stats =
579 bpf_map_lookup_elem(&stats, &conn_rate_key);
580
581 if (!conn_rate_stats)
582 return true;
583 cur_time = bpf_ktime_get_ns();
584 if ((cur_time - conn_rate_stats->v2) >> 32 > 0xffFFFF) {
585 conn_rate_stats->v1 = 1;
586 conn_rate_stats->v2 = cur_time;
587 } else {
588 conn_rate_stats->v1 += 1;
589 if (conn_rate_stats->v1 >= 1)
590 return true;
591 }
592 if (pckt->flow.proto == IPPROTO_UDP)
593 new_dst_lru.atime = cur_time;
594 new_dst_lru.pos = key;
595 bpf_map_update_elem(lru_map, &pckt->flow, &new_dst_lru, 0);
596 }
597 return true;
598}
599
600__attribute__ ((noinline))
601static void connection_table_lookup(struct real_definition **real,
602 struct packet_description *pckt,
603 void *lru_map)
604{
605
606 struct real_pos_lru *dst_lru;
607 __u64 cur_time;
608 __u32 key;
609
610 dst_lru = bpf_map_lookup_elem(lru_map, &pckt->flow);
611 if (!dst_lru)
612 return;
613 if (pckt->flow.proto == IPPROTO_UDP) {
614 cur_time = bpf_ktime_get_ns();
615 if (cur_time - dst_lru->atime > 300000)
616 return;
617 dst_lru->atime = cur_time;
618 }
619 key = dst_lru->pos;
620 *real = bpf_map_lookup_elem(&reals, &key);
621}
622
623/* don't believe your eyes!
624 * below function has 6 arguments whereas bpf and llvm allow maximum of 5
625 * but since it's _static_ llvm can optimize one argument away
626 */
627__attribute__ ((noinline))
628static int process_l3_headers_v6(struct packet_description *pckt,
629 __u8 *protocol, __u64 off,
630 __u16 *pkt_bytes, void *data,
631 void *data_end)
632{
633 struct ipv6hdr *ip6h;
634 __u64 iph_len;
635 int action;
636
637 ip6h = data + off;
638 if (ip6h + 1 > data_end)
639 return XDP_DROP;
640 iph_len = sizeof(struct ipv6hdr);
641 *protocol = ip6h->nexthdr;
642 pckt->flow.proto = *protocol;
643 *pkt_bytes = bpf_ntohs(ip6h->payload_len);
644 off += iph_len;
645 if (*protocol == 45) {
646 return XDP_DROP;
647 } else if (*protocol == 59) {
648 action = parse_icmpv6(data, data_end, off, pckt);
649 if (action >= 0)
650 return action;
651 } else {
652 memcpy(pckt->flow.srcv6, ip6h->saddr.in6_u.u6_addr32, 16);
653 memcpy(pckt->flow.dstv6, ip6h->daddr.in6_u.u6_addr32, 16);
654 }
655 return -1;
656}
657
658__attribute__ ((noinline))
659static int process_l3_headers_v4(struct packet_description *pckt,
660 __u8 *protocol, __u64 off,
661 __u16 *pkt_bytes, void *data,
662 void *data_end)
663{
664 struct iphdr *iph;
665 __u64 iph_len;
666 int action;
667
668 iph = data + off;
669 if (iph + 1 > data_end)
670 return XDP_DROP;
671 if (iph->ihl != 5)
672 return XDP_DROP;
673 *protocol = iph->protocol;
674 pckt->flow.proto = *protocol;
675 *pkt_bytes = bpf_ntohs(iph->tot_len);
676 off += 20;
677 if (iph->frag_off & 65343)
678 return XDP_DROP;
679 if (*protocol == IPPROTO_ICMP) {
680 action = parse_icmp(data, data_end, off, pckt);
681 if (action >= 0)
682 return action;
683 } else {
684 pckt->flow.src = iph->saddr;
685 pckt->flow.dst = iph->daddr;
686 }
687 return -1;
688}
689
690__attribute__ ((noinline))
691static int process_packet(void *data, __u64 off, void *data_end,
692 bool is_ipv6, struct xdp_md *xdp)
693{
694
695 struct real_definition *dst = NULL;
696 struct packet_description pckt = { };
697 struct vip_definition vip = { };
698 struct lb_stats *data_stats;
699 struct eth_hdr *eth = data;
700 void *lru_map = &lru_cache;
701 struct vip_meta *vip_info;
702 __u32 lru_stats_key = 513;
703 __u32 mac_addr_pos = 0;
704 __u32 stats_key = 512;
705 struct ctl_value *cval;
706 __u16 pkt_bytes;
707 __u64 iph_len;
708 __u8 protocol;
709 __u32 vip_num;
710 int action;
711
712 if (is_ipv6)
713 action = process_l3_headers_v6(&pckt, &protocol, off,
714 &pkt_bytes, data, data_end);
715 else
716 action = process_l3_headers_v4(&pckt, &protocol, off,
717 &pkt_bytes, data, data_end);
718 if (action >= 0)
719 return action;
720 protocol = pckt.flow.proto;
721 if (protocol == IPPROTO_TCP) {
722 if (!parse_tcp(data, data_end, is_ipv6, &pckt))
723 return XDP_DROP;
724 } else if (protocol == IPPROTO_UDP) {
725 if (!parse_udp(data, data_end, is_ipv6, &pckt))
726 return XDP_DROP;
727 } else {
728 return XDP_TX;
729 }
730
731 if (is_ipv6)
732 memcpy(vip.vipv6, pckt.flow.dstv6, 16);
733 else
734 vip.vip = pckt.flow.dst;
735 vip.port = pckt.flow.port16[1];
736 vip.proto = pckt.flow.proto;
737 vip_info = bpf_map_lookup_elem(&vip_map, &vip);
738 if (!vip_info) {
739 vip.port = 0;
740 vip_info = bpf_map_lookup_elem(&vip_map, &vip);
741 if (!vip_info)
742 return XDP_PASS;
743 if (!(vip_info->flags & (1 << 4)))
744 pckt.flow.port16[1] = 0;
745 }
746 if (data_end - data > 1400)
747 return XDP_DROP;
748 data_stats = bpf_map_lookup_elem(&stats, &stats_key);
749 if (!data_stats)
750 return XDP_DROP;
751 data_stats->v1 += 1;
752 if (!dst) {
753 if (vip_info->flags & (1 << 0))
754 pckt.flow.port16[0] = 0;
755 if (!(pckt.flags & (1 << 1)) && !(vip_info->flags & (1 << 1)))
756 connection_table_lookup(&dst, &pckt, lru_map);
757 if (dst)
758 goto out;
759 if (pckt.flow.proto == IPPROTO_TCP) {
760 struct lb_stats *lru_stats =
761 bpf_map_lookup_elem(&stats, &lru_stats_key);
762
763 if (!lru_stats)
764 return XDP_DROP;
765 if (pckt.flags & (1 << 1))
766 lru_stats->v1 += 1;
767 else
768 lru_stats->v2 += 1;
769 }
770 if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6, lru_map))
771 return XDP_DROP;
772 data_stats->v2 += 1;
773 }
774out:
775 cval = bpf_map_lookup_elem(&ctl_array, &mac_addr_pos);
776 if (!cval)
777 return XDP_DROP;
778 if (dst->flags & (1 << 0)) {
779 if (!encap_v6(xdp, cval, &pckt, dst, pkt_bytes))
780 return XDP_DROP;
781 } else {
782 if (!encap_v4(xdp, cval, &pckt, dst, pkt_bytes))
783 return XDP_DROP;
784 }
785 vip_num = vip_info->vip_num;
786 data_stats = bpf_map_lookup_elem(&stats, &vip_num);
787 if (!data_stats)
788 return XDP_DROP;
789 data_stats->v1 += 1;
790 data_stats->v2 += pkt_bytes;
791
792 data = (void *)(long)xdp->data;
793 data_end = (void *)(long)xdp->data_end;
794 if (data + 4 > data_end)
795 return XDP_DROP;
796 *(u32 *)data = dst->dst;
797 return XDP_DROP;
798}
799
800SEC("xdp")
801int balancer_ingress_v4(struct xdp_md *ctx)
802{
803 void *data = (void *)(long)ctx->data;
804 void *data_end = (void *)(long)ctx->data_end;
805 struct eth_hdr *eth = data;
806 __u32 eth_proto;
807 __u32 nh_off;
808
809 nh_off = sizeof(struct eth_hdr);
810 if (data + nh_off > data_end)
811 return XDP_DROP;
812 eth_proto = bpf_ntohs(eth->eth_proto);
813 if (eth_proto == ETH_P_IP)
814 return process_packet(data, nh_off, data_end, 0, ctx);
815 else
816 return XDP_DROP;
817}
818
819SEC("xdp")
820int balancer_ingress_v6(struct xdp_md *ctx)
821{
822 void *data = (void *)(long)ctx->data;
823 void *data_end = (void *)(long)ctx->data_end;
824 struct eth_hdr *eth = data;
825 __u32 eth_proto;
826 __u32 nh_off;
827
828 nh_off = sizeof(struct eth_hdr);
829 if (data + nh_off > data_end)
830 return XDP_DROP;
831 eth_proto = bpf_ntohs(eth->eth_proto);
832 if (eth_proto == ETH_P_IPV6)
833 return process_packet(data, nh_off, data_end, 1, ctx);
834 else
835 return XDP_DROP;
836}
837
838char _license[] SEC("license") = "GPL";