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
rol32(__u32 word,unsigned int shift)20 static __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
51 typedef unsigned int u32;
52
53 static __noinline
jhash(const void * key,u32 length,u32 initval)54 u32 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
__jhash_nwords(u32 a,u32 b,u32 c,u32 initval)91 u32 __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
jhash_2words(u32 a,u32 b,u32 initval)101 u32 jhash_2words(u32 a, u32 b, u32 initval)
102 {
103 return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2));
104 }
105
106 struct 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
122 struct packet_description {
123 struct flow_key flow;
124 __u8 flags;
125 };
126
127 struct ctl_value {
128 union {
129 __u64 value;
130 __u32 ifindex;
131 __u8 mac[6];
132 };
133 };
134
135 struct vip_definition {
136 union {
137 __be32 vip;
138 __be32 vipv6[4];
139 };
140 __u16 port;
141 __u16 family;
142 __u8 proto;
143 };
144
145 struct vip_meta {
146 __u32 flags;
147 __u32 vip_num;
148 };
149
150 struct real_pos_lru {
151 __u32 pos;
152 __u64 atime;
153 };
154
155 struct real_definition {
156 union {
157 __be32 dst;
158 __be32 dstv6[4];
159 };
160 __u8 flags;
161 };
162
163 struct lb_stats {
164 __u64 v2;
165 __u64 v1;
166 };
167
168 struct {
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
175 struct {
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
183 struct {
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
190 struct {
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
197 struct {
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
204 struct {
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
211 struct eth_hdr {
212 unsigned char eth_dest[6];
213 unsigned char eth_source[6];
214 unsigned short eth_proto;
215 };
216
calc_offset(bool is_ipv6,bool is_icmp)217 static __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
232 static __attribute__ ((noinline))
parse_udp(void * data,void * data_end,bool is_ipv6,struct packet_description * pckt)233 bool 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
254 static __attribute__ ((noinline))
parse_tcp(void * data,void * data_end,bool is_ipv6,struct packet_description * pckt)255 bool 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
278 static __attribute__ ((noinline))
encap_v6(struct xdp_md * xdp,struct ctl_value * cval,struct packet_description * pckt,struct real_definition * dst,__u32 pkt_bytes)279 bool 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
329 static __attribute__ ((noinline))
encap_v4(struct xdp_md * xdp,struct ctl_value * cval,struct packet_description * pckt,struct real_definition * dst,__u32 pkt_bytes)330 bool 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
387 static __attribute__ ((noinline))
swap_mac_and_send(void * data,void * data_end)388 int 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
400 static __attribute__ ((noinline))
send_icmp_reply(void * data,void * data_end)401 int 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
432 static __attribute__ ((noinline))
send_icmp6_reply(void * data,void * data_end)433 int 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
456 static __attribute__ ((noinline))
parse_icmpv6(void * data,void * data_end,__u64 off,struct packet_description * pckt)457 int 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
481 static __attribute__ ((noinline))
parse_icmp(void * data,void * data_end,__u64 off,struct packet_description * pckt)482 int 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
508 static __attribute__ ((noinline))
get_packet_hash(struct packet_description * pckt,bool hash_16bytes)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))
get_packet_dst(struct real_definition ** real,struct packet_description * pckt,struct vip_meta * vip_info,bool is_ipv6,void * lru_map)521 static 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))
connection_table_lookup(struct real_definition ** real,struct packet_description * pckt,void * lru_map)574 static 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))
process_l3_headers_v6(struct packet_description * pckt,__u8 * protocol,__u64 off,__u16 * pkt_bytes,void * extra_args[2])601 static 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))
process_l3_headers_v4(struct packet_description * pckt,__u8 * protocol,__u64 off,__u16 * pkt_bytes,void * extra_args[2])633 static 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))
process_packet(void * data,__u64 off,void * data_end,bool is_ipv6,struct xdp_md * xdp)665 static 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 }
747 out:
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
773 SEC("xdp")
balancer_ingress_v4(struct xdp_md * ctx)774 int 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
792 SEC("xdp")
balancer_ingress_v6(struct xdp_md * ctx)793 int 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
811 char _license[] SEC("license") = "GPL";
812