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
rol32(__u32 word,unsigned int shift)19 static __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
50 typedef unsigned int u32;
51
52 static __noinline
jhash(const void * key,u32 length,u32 initval)53 u32 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
__jhash_nwords(u32 a,u32 b,u32 c,u32 initval)90 u32 __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
jhash_2words(u32 a,u32 b,u32 initval)100 u32 jhash_2words(u32 a, u32 b, u32 initval)
101 {
102 return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
103 }
104
105 struct 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
121 struct packet_description {
122 struct flow_key flow;
123 __u8 flags;
124 };
125
126 struct ctl_value {
127 union {
128 __u64 value;
129 __u32 ifindex;
130 __u8 mac[6];
131 };
132 };
133
134 struct vip_definition {
135 union {
136 __be32 vip;
137 __be32 vipv6[4];
138 };
139 __u16 port;
140 __u16 family;
141 __u8 proto;
142 };
143
144 struct vip_meta {
145 __u32 flags;
146 __u32 vip_num;
147 };
148
149 struct real_pos_lru {
150 __u32 pos;
151 __u64 atime;
152 };
153
154 struct real_definition {
155 union {
156 __be32 dst;
157 __be32 dstv6[4];
158 };
159 __u8 flags;
160 };
161
162 struct lb_stats {
163 __u64 v2;
164 __u64 v1;
165 };
166
167 struct {
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
174 struct {
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
182 struct {
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
189 struct {
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
196 struct {
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
203 struct {
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
210 struct eth_hdr {
211 unsigned char eth_dest[6];
212 unsigned char eth_source[6];
213 unsigned short eth_proto;
214 };
215
calc_offset(bool is_ipv6,bool is_icmp)216 static __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
231 static __attribute__ ((noinline))
parse_udp(void * data,void * data_end,bool is_ipv6,struct packet_description * pckt)232 bool 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 0;
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 1;
251 }
252
253 static __attribute__ ((noinline))
parse_tcp(void * data,void * data_end,bool is_ipv6,struct packet_description * pckt)254 bool 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 0;
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 1;
275 }
276
277 static __attribute__ ((noinline))
encap_v6(struct xdp_md * xdp,struct ctl_value * cval,struct packet_description * pckt,struct real_definition * dst,__u32 pkt_bytes)278 bool 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 0;
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 0;
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 1;
318 }
319
320 static __attribute__ ((noinline))
encap_v4(struct xdp_md * xdp,struct ctl_value * cval,struct packet_description * pckt,struct real_definition * dst,__u32 pkt_bytes)321 bool 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 0;
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 0;
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 0;
371 return 1;
372 }
373
374 static __attribute__ ((noinline))
decap_v6(struct xdp_md * xdp,void ** data,void ** data_end,bool inner_v4)375 bool 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 0;
390 *data = (void *)(long)xdp->data;
391 *data_end = (void *)(long)xdp->data_end;
392 return 1;
393 }
394
395 static __attribute__ ((noinline))
decap_v4(struct xdp_md * xdp,void ** data,void ** data_end)396 bool 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 0;
408 *data = (void *)(long)xdp->data;
409 *data_end = (void *)(long)xdp->data_end;
410 return 1;
411 }
412
413 static __attribute__ ((noinline))
swap_mac_and_send(void * data,void * data_end)414 int 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
426 static __attribute__ ((noinline))
send_icmp_reply(void * data,void * data_end)427 int 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
459 static __attribute__ ((noinline))
send_icmp6_reply(void * data,void * data_end)460 int 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
483 static __attribute__ ((noinline))
parse_icmpv6(void * data,void * data_end,__u64 off,struct packet_description * pckt)484 int 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
508 static __attribute__ ((noinline))
parse_icmp(void * data,void * data_end,__u64 off,struct packet_description * pckt)509 int 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
535 static __attribute__ ((noinline))
get_packet_hash(struct packet_description * pckt,bool hash_16bytes)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))
get_packet_dst(struct real_definition ** real,struct packet_description * pckt,struct vip_meta * vip_info,bool is_ipv6,void * lru_map)548 static 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))
connection_table_lookup(struct real_definition ** real,struct packet_description * pckt,void * lru_map)601 static 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))
process_l3_headers_v6(struct packet_description * pckt,__u8 * protocol,__u64 off,__u16 * pkt_bytes,void * data,void * data_end)628 static 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))
process_l3_headers_v4(struct packet_description * pckt,__u8 * protocol,__u64 off,__u16 * pkt_bytes,void * data,void * data_end)659 static 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))
process_packet(void * data,__u64 off,void * data_end,bool is_ipv6,struct xdp_md * xdp)691 static 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 }
774 out:
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
800 SEC("xdp")
balancer_ingress_v4(struct xdp_md * ctx)801 int 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
819 SEC("xdp")
balancer_ingress_v6(struct xdp_md * ctx)820 int 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
838 char _license[] SEC("license") = "GPL";
839