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 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
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 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
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 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
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 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
374 static __attribute__ ((noinline))
swap_mac_and_send(void * data,void * data_end)375 int swap_mac_and_send(void *data, void *data_end)
376 {
377 unsigned char tmp_mac[6];
378 struct eth_hdr *eth;
379
380 eth = data;
381 memcpy(tmp_mac, eth->eth_source, 6);
382 memcpy(eth->eth_source, eth->eth_dest, 6);
383 memcpy(eth->eth_dest, tmp_mac, 6);
384 return XDP_TX;
385 }
386
387 static __attribute__ ((noinline))
send_icmp_reply(void * data,void * data_end)388 int send_icmp_reply(void *data, void *data_end)
389 {
390 struct icmphdr *icmp_hdr;
391 __u16 *next_iph_u16;
392 __u32 tmp_addr = 0;
393 struct iphdr *iph;
394 __u32 csum = 0;
395 __u64 off = 0;
396
397 if (data + sizeof(struct eth_hdr)
398 + sizeof(struct iphdr) + sizeof(struct icmphdr) > data_end)
399 return XDP_DROP;
400 off += sizeof(struct eth_hdr);
401 iph = data + off;
402 off += sizeof(struct iphdr);
403 icmp_hdr = data + off;
404 icmp_hdr->type = 0;
405 icmp_hdr->checksum += 0x0007;
406 iph->ttl = 4;
407 tmp_addr = iph->daddr;
408 iph->daddr = iph->saddr;
409 iph->saddr = tmp_addr;
410 iph->check = 0;
411 next_iph_u16 = (__u16 *) iph;
412 #pragma clang loop unroll(full)
413 for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
414 csum += *next_iph_u16++;
415 iph->check = ~((csum & 0xffff) + (csum >> 16));
416 return swap_mac_and_send(data, data_end);
417 }
418
419 static __attribute__ ((noinline))
send_icmp6_reply(void * data,void * data_end)420 int send_icmp6_reply(void *data, void *data_end)
421 {
422 struct icmp6hdr *icmp_hdr;
423 struct ipv6hdr *ip6h;
424 __be32 tmp_addr[4];
425 __u64 off = 0;
426
427 if (data + sizeof(struct eth_hdr)
428 + sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr) > data_end)
429 return XDP_DROP;
430 off += sizeof(struct eth_hdr);
431 ip6h = data + off;
432 off += sizeof(struct ipv6hdr);
433 icmp_hdr = data + off;
434 icmp_hdr->icmp6_type = 129;
435 icmp_hdr->icmp6_cksum -= 0x0001;
436 ip6h->hop_limit = 4;
437 memcpy(tmp_addr, ip6h->saddr.in6_u.u6_addr32, 16);
438 memcpy(ip6h->saddr.in6_u.u6_addr32, ip6h->daddr.in6_u.u6_addr32, 16);
439 memcpy(ip6h->daddr.in6_u.u6_addr32, tmp_addr, 16);
440 return swap_mac_and_send(data, data_end);
441 }
442
443 static __attribute__ ((noinline))
parse_icmpv6(void * data,void * data_end,__u64 off,struct packet_description * pckt)444 int parse_icmpv6(void *data, void *data_end, __u64 off,
445 struct packet_description *pckt)
446 {
447 struct icmp6hdr *icmp_hdr;
448 struct ipv6hdr *ip6h;
449
450 icmp_hdr = data + off;
451 if (icmp_hdr + 1 > data_end)
452 return XDP_DROP;
453 if (icmp_hdr->icmp6_type == 128)
454 return send_icmp6_reply(data, data_end);
455 if (icmp_hdr->icmp6_type != 3)
456 return XDP_PASS;
457 off += sizeof(struct icmp6hdr);
458 ip6h = data + off;
459 if (ip6h + 1 > data_end)
460 return XDP_DROP;
461 pckt->flow.proto = ip6h->nexthdr;
462 pckt->flags |= (1 << 0);
463 memcpy(pckt->flow.srcv6, ip6h->daddr.in6_u.u6_addr32, 16);
464 memcpy(pckt->flow.dstv6, ip6h->saddr.in6_u.u6_addr32, 16);
465 return -1;
466 }
467
468 static __attribute__ ((noinline))
parse_icmp(void * data,void * data_end,__u64 off,struct packet_description * pckt)469 int parse_icmp(void *data, void *data_end, __u64 off,
470 struct packet_description *pckt)
471 {
472 struct icmphdr *icmp_hdr;
473 struct iphdr *iph;
474
475 icmp_hdr = data + off;
476 if (icmp_hdr + 1 > data_end)
477 return XDP_DROP;
478 if (icmp_hdr->type == 8)
479 return send_icmp_reply(data, data_end);
480 if ((icmp_hdr->type != 3) || (icmp_hdr->code != 4))
481 return XDP_PASS;
482 off += sizeof(struct icmphdr);
483 iph = data + off;
484 if (iph + 1 > data_end)
485 return XDP_DROP;
486 if (iph->ihl != 5)
487 return XDP_DROP;
488 pckt->flow.proto = iph->protocol;
489 pckt->flags |= (1 << 0);
490 pckt->flow.src = iph->daddr;
491 pckt->flow.dst = iph->saddr;
492 return -1;
493 }
494
495 static __attribute__ ((noinline))
get_packet_hash(struct packet_description * pckt,bool hash_16bytes)496 __u32 get_packet_hash(struct packet_description *pckt,
497 bool hash_16bytes)
498 {
499 if (hash_16bytes)
500 return jhash_2words(jhash(pckt->flow.srcv6, 16, 12),
501 pckt->flow.ports, 24);
502 else
503 return jhash_2words(pckt->flow.src, pckt->flow.ports,
504 24);
505 }
506
507 __attribute__ ((noinline))
get_packet_dst(struct real_definition ** real,struct packet_description * pckt,struct vip_meta * vip_info,bool is_ipv6,void * lru_map)508 static bool get_packet_dst(struct real_definition **real,
509 struct packet_description *pckt,
510 struct vip_meta *vip_info,
511 bool is_ipv6, void *lru_map)
512 {
513 struct real_pos_lru new_dst_lru = { };
514 bool hash_16bytes = is_ipv6;
515 __u32 *real_pos, hash, key;
516 __u64 cur_time;
517
518 if (vip_info->flags & (1 << 2))
519 hash_16bytes = 1;
520 if (vip_info->flags & (1 << 3)) {
521 pckt->flow.port16[0] = pckt->flow.port16[1];
522 memset(pckt->flow.srcv6, 0, 16);
523 }
524 hash = get_packet_hash(pckt, hash_16bytes);
525 if (hash != 0x358459b7 /* jhash of ipv4 packet */ &&
526 hash != 0x2f4bc6bb /* jhash of ipv6 packet */)
527 return false;
528 key = 2 * vip_info->vip_num + hash % 2;
529 real_pos = bpf_map_lookup_elem(&ch_rings, &key);
530 if (!real_pos)
531 return false;
532 key = *real_pos;
533 *real = bpf_map_lookup_elem(&reals, &key);
534 if (!(*real))
535 return false;
536 if (!(vip_info->flags & (1 << 1))) {
537 __u32 conn_rate_key = 512 + 2;
538 struct lb_stats *conn_rate_stats =
539 bpf_map_lookup_elem(&stats, &conn_rate_key);
540
541 if (!conn_rate_stats)
542 return true;
543 cur_time = bpf_ktime_get_ns();
544 if ((cur_time - conn_rate_stats->v2) >> 32 > 0xffFFFF) {
545 conn_rate_stats->v1 = 1;
546 conn_rate_stats->v2 = cur_time;
547 } else {
548 conn_rate_stats->v1 += 1;
549 if (conn_rate_stats->v1 >= 1)
550 return true;
551 }
552 if (pckt->flow.proto == IPPROTO_UDP)
553 new_dst_lru.atime = cur_time;
554 new_dst_lru.pos = key;
555 bpf_map_update_elem(lru_map, &pckt->flow, &new_dst_lru, 0);
556 }
557 return true;
558 }
559
560 __attribute__ ((noinline))
connection_table_lookup(struct real_definition ** real,struct packet_description * pckt,void * lru_map)561 static void connection_table_lookup(struct real_definition **real,
562 struct packet_description *pckt,
563 void *lru_map)
564 {
565
566 struct real_pos_lru *dst_lru;
567 __u64 cur_time;
568 __u32 key;
569
570 dst_lru = bpf_map_lookup_elem(lru_map, &pckt->flow);
571 if (!dst_lru)
572 return;
573 if (pckt->flow.proto == IPPROTO_UDP) {
574 cur_time = bpf_ktime_get_ns();
575 if (cur_time - dst_lru->atime > 300000)
576 return;
577 dst_lru->atime = cur_time;
578 }
579 key = dst_lru->pos;
580 *real = bpf_map_lookup_elem(&reals, &key);
581 }
582
583 /* don't believe your eyes!
584 * below function has 6 arguments whereas bpf and llvm allow maximum of 5
585 * but since it's _static_ llvm can optimize one argument away
586 */
587 __attribute__ ((noinline))
process_l3_headers_v6(struct packet_description * pckt,__u8 * protocol,__u64 off,__u16 * pkt_bytes,void * data,void * data_end)588 static int process_l3_headers_v6(struct packet_description *pckt,
589 __u8 *protocol, __u64 off,
590 __u16 *pkt_bytes, void *data,
591 void *data_end)
592 {
593 struct ipv6hdr *ip6h;
594 __u64 iph_len;
595 int action;
596
597 ip6h = data + off;
598 if (ip6h + 1 > data_end)
599 return XDP_DROP;
600 iph_len = sizeof(struct ipv6hdr);
601 *protocol = ip6h->nexthdr;
602 pckt->flow.proto = *protocol;
603 *pkt_bytes = bpf_ntohs(ip6h->payload_len);
604 off += iph_len;
605 if (*protocol == 45) {
606 return XDP_DROP;
607 } else if (*protocol == 59) {
608 action = parse_icmpv6(data, data_end, off, pckt);
609 if (action >= 0)
610 return action;
611 } else {
612 memcpy(pckt->flow.srcv6, ip6h->saddr.in6_u.u6_addr32, 16);
613 memcpy(pckt->flow.dstv6, ip6h->daddr.in6_u.u6_addr32, 16);
614 }
615 return -1;
616 }
617
618 __attribute__ ((noinline))
process_l3_headers_v4(struct packet_description * pckt,__u8 * protocol,__u64 off,__u16 * pkt_bytes,void * data,void * data_end)619 static int process_l3_headers_v4(struct packet_description *pckt,
620 __u8 *protocol, __u64 off,
621 __u16 *pkt_bytes, void *data,
622 void *data_end)
623 {
624 struct iphdr *iph;
625 int action;
626
627 iph = data + off;
628 if (iph + 1 > data_end)
629 return XDP_DROP;
630 if (iph->ihl != 5)
631 return XDP_DROP;
632 *protocol = iph->protocol;
633 pckt->flow.proto = *protocol;
634 *pkt_bytes = bpf_ntohs(iph->tot_len);
635 off += 20;
636 if (iph->frag_off & 65343)
637 return XDP_DROP;
638 if (*protocol == IPPROTO_ICMP) {
639 action = parse_icmp(data, data_end, off, pckt);
640 if (action >= 0)
641 return action;
642 } else {
643 pckt->flow.src = iph->saddr;
644 pckt->flow.dst = iph->daddr;
645 }
646 return -1;
647 }
648
649 __attribute__ ((noinline))
process_packet(void * data,__u64 off,void * data_end,bool is_ipv6,struct xdp_md * xdp)650 static int process_packet(void *data, __u64 off, void *data_end,
651 bool is_ipv6, struct xdp_md *xdp)
652 {
653
654 struct real_definition *dst = NULL;
655 struct packet_description pckt = { };
656 struct vip_definition vip = { };
657 struct lb_stats *data_stats;
658 void *lru_map = &lru_cache;
659 struct vip_meta *vip_info;
660 __u32 lru_stats_key = 513;
661 __u32 mac_addr_pos = 0;
662 __u32 stats_key = 512;
663 struct ctl_value *cval;
664 __u16 pkt_bytes;
665 __u8 protocol;
666 __u32 vip_num;
667 int action;
668
669 if (is_ipv6)
670 action = process_l3_headers_v6(&pckt, &protocol, off,
671 &pkt_bytes, data, data_end);
672 else
673 action = process_l3_headers_v4(&pckt, &protocol, off,
674 &pkt_bytes, data, data_end);
675 if (action >= 0)
676 return action;
677 protocol = pckt.flow.proto;
678 if (protocol == IPPROTO_TCP) {
679 if (!parse_tcp(data, data_end, is_ipv6, &pckt))
680 return XDP_DROP;
681 } else if (protocol == IPPROTO_UDP) {
682 if (!parse_udp(data, data_end, is_ipv6, &pckt))
683 return XDP_DROP;
684 } else {
685 return XDP_TX;
686 }
687
688 if (is_ipv6)
689 memcpy(vip.vipv6, pckt.flow.dstv6, 16);
690 else
691 vip.vip = pckt.flow.dst;
692 vip.port = pckt.flow.port16[1];
693 vip.proto = pckt.flow.proto;
694 vip_info = bpf_map_lookup_elem(&vip_map, &vip);
695 if (!vip_info) {
696 vip.port = 0;
697 vip_info = bpf_map_lookup_elem(&vip_map, &vip);
698 if (!vip_info)
699 return XDP_PASS;
700 if (!(vip_info->flags & (1 << 4)))
701 pckt.flow.port16[1] = 0;
702 }
703 if (data_end - data > 1400)
704 return XDP_DROP;
705 data_stats = bpf_map_lookup_elem(&stats, &stats_key);
706 if (!data_stats)
707 return XDP_DROP;
708 data_stats->v1 += 1;
709 if (!dst) {
710 if (vip_info->flags & (1 << 0))
711 pckt.flow.port16[0] = 0;
712 if (!(pckt.flags & (1 << 1)) && !(vip_info->flags & (1 << 1)))
713 connection_table_lookup(&dst, &pckt, lru_map);
714 if (dst)
715 goto out;
716 if (pckt.flow.proto == IPPROTO_TCP) {
717 struct lb_stats *lru_stats =
718 bpf_map_lookup_elem(&stats, &lru_stats_key);
719
720 if (!lru_stats)
721 return XDP_DROP;
722 if (pckt.flags & (1 << 1))
723 lru_stats->v1 += 1;
724 else
725 lru_stats->v2 += 1;
726 }
727 if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6, lru_map))
728 return XDP_DROP;
729 data_stats->v2 += 1;
730 }
731 out:
732 cval = bpf_map_lookup_elem(&ctl_array, &mac_addr_pos);
733 if (!cval)
734 return XDP_DROP;
735 if (dst->flags & (1 << 0)) {
736 if (!encap_v6(xdp, cval, &pckt, dst, pkt_bytes))
737 return XDP_DROP;
738 } else {
739 if (!encap_v4(xdp, cval, &pckt, dst, pkt_bytes))
740 return XDP_DROP;
741 }
742 vip_num = vip_info->vip_num;
743 data_stats = bpf_map_lookup_elem(&stats, &vip_num);
744 if (!data_stats)
745 return XDP_DROP;
746 data_stats->v1 += 1;
747 data_stats->v2 += pkt_bytes;
748
749 data = (void *)(long)xdp->data;
750 data_end = (void *)(long)xdp->data_end;
751 if (data + 4 > data_end)
752 return XDP_DROP;
753 *(u32 *)data = dst->dst;
754 return XDP_DROP;
755 }
756
757 SEC("xdp")
balancer_ingress_v4(struct xdp_md * ctx)758 int balancer_ingress_v4(struct xdp_md *ctx)
759 {
760 void *data = (void *)(long)ctx->data;
761 void *data_end = (void *)(long)ctx->data_end;
762 struct eth_hdr *eth = data;
763 __u32 eth_proto;
764 __u32 nh_off;
765
766 nh_off = sizeof(struct eth_hdr);
767 if (data + nh_off > data_end)
768 return XDP_DROP;
769 eth_proto = bpf_ntohs(eth->eth_proto);
770 if (eth_proto == ETH_P_IP)
771 return process_packet(data, nh_off, data_end, 0, ctx);
772 else
773 return XDP_DROP;
774 }
775
776 SEC("xdp")
balancer_ingress_v6(struct xdp_md * ctx)777 int balancer_ingress_v6(struct xdp_md *ctx)
778 {
779 void *data = (void *)(long)ctx->data;
780 void *data_end = (void *)(long)ctx->data_end;
781 struct eth_hdr *eth = data;
782 __u32 eth_proto;
783 __u32 nh_off;
784
785 nh_off = sizeof(struct eth_hdr);
786 if (data + nh_off > data_end)
787 return XDP_DROP;
788 eth_proto = bpf_ntohs(eth->eth_proto);
789 if (eth_proto == ETH_P_IPV6)
790 return process_packet(data, nh_off, data_end, 1, ctx);
791 else
792 return XDP_DROP;
793 }
794
795 char _license[] SEC("license") = "GPL";
796
