xref: /linux/tools/testing/selftests/bpf/progs/test_xdp_noinline.c (revision 7255fcc80d4b525cc10cfaaf7f485830d4ed2000)
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 
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
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
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
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 
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))
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))
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))
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 static __attribute__ ((noinline))
322 bool encap_v4(struct xdp_md *xdp, struct ctl_value *cval,
323 	      struct packet_description *pckt,
324 	      struct real_definition *dst, __u32 pkt_bytes)
325 {
326 
327 	__u32 ip_suffix = bpf_ntohs(pckt->flow.port16[0]);
328 	struct eth_hdr *new_eth;
329 	struct eth_hdr *old_eth;
330 	__u16 *next_iph_u16;
331 	struct iphdr *iph;
332 	__u32 csum = 0;
333 	void *data_end;
334 	void *data;
335 
336 	ip_suffix <<= 15;
337 	ip_suffix ^= pckt->flow.src;
338 	if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct iphdr)))
339 		return false;
340 	data = (void *)(long)xdp->data;
341 	data_end = (void *)(long)xdp->data_end;
342 	new_eth = data;
343 	iph = data + sizeof(struct eth_hdr);
344 	old_eth = data + sizeof(struct iphdr);
345 	if (new_eth + 1 > data_end ||
346 	    old_eth + 1 > data_end || iph + 1 > data_end)
347 		return false;
348 	memcpy(new_eth->eth_dest, cval->mac, 6);
349 	memcpy(new_eth->eth_source, old_eth->eth_dest, 6);
350 	new_eth->eth_proto = 8;
351 	iph->version = 4;
352 	iph->ihl = 5;
353 	iph->frag_off = 0;
354 	iph->protocol = IPPROTO_IPIP;
355 	iph->check = 0;
356 	iph->tos = 1;
357 	iph->tot_len = bpf_htons(pkt_bytes + sizeof(struct iphdr));
358 	/* don't update iph->daddr, since it will overwrite old eth_proto
359 	 * and multiple iterations of bpf_prog_run() will fail
360 	 */
361 
362 	iph->saddr = ((0xFFFF0000 & ip_suffix) | 4268) ^ dst->dst;
363 	iph->ttl = 4;
364 
365 	next_iph_u16 = (__u16 *) iph;
366 	__pragma_loop_unroll_full
367 	for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
368 		csum += *next_iph_u16++;
369 	iph->check = ~((csum & 0xffff) + (csum >> 16));
370 	if (bpf_xdp_adjust_head(xdp, (int)sizeof(struct iphdr)))
371 		return false;
372 	return true;
373 }
374 
375 static __attribute__ ((noinline))
376 int swap_mac_and_send(void *data, void *data_end)
377 {
378 	unsigned char tmp_mac[6];
379 	struct eth_hdr *eth;
380 
381 	eth = data;
382 	memcpy(tmp_mac, eth->eth_source, 6);
383 	memcpy(eth->eth_source, eth->eth_dest, 6);
384 	memcpy(eth->eth_dest, tmp_mac, 6);
385 	return XDP_TX;
386 }
387 
388 static __attribute__ ((noinline))
389 int send_icmp_reply(void *data, void *data_end)
390 {
391 	struct icmphdr *icmp_hdr;
392 	__u16 *next_iph_u16;
393 	__u32 tmp_addr = 0;
394 	struct iphdr *iph;
395 	__u32 csum = 0;
396 	__u64 off = 0;
397 
398 	if (data + sizeof(struct eth_hdr)
399 	     + sizeof(struct iphdr) + sizeof(struct icmphdr) > data_end)
400 		return XDP_DROP;
401 	off += sizeof(struct eth_hdr);
402 	iph = data + off;
403 	off += sizeof(struct iphdr);
404 	icmp_hdr = data + off;
405 	icmp_hdr->type = 0;
406 	icmp_hdr->checksum += 0x0007;
407 	iph->ttl = 4;
408 	tmp_addr = iph->daddr;
409 	iph->daddr = iph->saddr;
410 	iph->saddr = tmp_addr;
411 	iph->check = 0;
412 	next_iph_u16 = (__u16 *) iph;
413 	__pragma_loop_unroll_full
414 	for (int i = 0; i < sizeof(struct iphdr) >> 1; i++)
415 		csum += *next_iph_u16++;
416 	iph->check = ~((csum & 0xffff) + (csum >> 16));
417 	return swap_mac_and_send(data, data_end);
418 }
419 
420 static __attribute__ ((noinline))
421 int send_icmp6_reply(void *data, void *data_end)
422 {
423 	struct icmp6hdr *icmp_hdr;
424 	struct ipv6hdr *ip6h;
425 	__be32 tmp_addr[4];
426 	__u64 off = 0;
427 
428 	if (data + sizeof(struct eth_hdr)
429 	     + sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr) > data_end)
430 		return XDP_DROP;
431 	off += sizeof(struct eth_hdr);
432 	ip6h = data + off;
433 	off += sizeof(struct ipv6hdr);
434 	icmp_hdr = data + off;
435 	icmp_hdr->icmp6_type = 129;
436 	icmp_hdr->icmp6_cksum -= 0x0001;
437 	ip6h->hop_limit = 4;
438 	memcpy(tmp_addr, ip6h->saddr.in6_u.u6_addr32, 16);
439 	memcpy(ip6h->saddr.in6_u.u6_addr32, ip6h->daddr.in6_u.u6_addr32, 16);
440 	memcpy(ip6h->daddr.in6_u.u6_addr32, tmp_addr, 16);
441 	return swap_mac_and_send(data, data_end);
442 }
443 
444 static __attribute__ ((noinline))
445 int parse_icmpv6(void *data, void *data_end, __u64 off,
446 		 struct packet_description *pckt)
447 {
448 	struct icmp6hdr *icmp_hdr;
449 	struct ipv6hdr *ip6h;
450 
451 	icmp_hdr = data + off;
452 	if (icmp_hdr + 1 > data_end)
453 		return XDP_DROP;
454 	if (icmp_hdr->icmp6_type == 128)
455 		return send_icmp6_reply(data, data_end);
456 	if (icmp_hdr->icmp6_type != 3)
457 		return XDP_PASS;
458 	off += sizeof(struct icmp6hdr);
459 	ip6h = data + off;
460 	if (ip6h + 1 > data_end)
461 		return XDP_DROP;
462 	pckt->flow.proto = ip6h->nexthdr;
463 	pckt->flags |= (1 << 0);
464 	memcpy(pckt->flow.srcv6, ip6h->daddr.in6_u.u6_addr32, 16);
465 	memcpy(pckt->flow.dstv6, ip6h->saddr.in6_u.u6_addr32, 16);
466 	return -1;
467 }
468 
469 static __attribute__ ((noinline))
470 int parse_icmp(void *data, void *data_end, __u64 off,
471 	       struct packet_description *pckt)
472 {
473 	struct icmphdr *icmp_hdr;
474 	struct iphdr *iph;
475 
476 	icmp_hdr = data + off;
477 	if (icmp_hdr + 1 > data_end)
478 		return XDP_DROP;
479 	if (icmp_hdr->type == 8)
480 		return send_icmp_reply(data, data_end);
481 	if ((icmp_hdr->type != 3) || (icmp_hdr->code != 4))
482 		return XDP_PASS;
483 	off += sizeof(struct icmphdr);
484 	iph = data + off;
485 	if (iph + 1 > data_end)
486 		return XDP_DROP;
487 	if (iph->ihl != 5)
488 		return XDP_DROP;
489 	pckt->flow.proto = iph->protocol;
490 	pckt->flags |= (1 << 0);
491 	pckt->flow.src = iph->daddr;
492 	pckt->flow.dst = iph->saddr;
493 	return -1;
494 }
495 
496 static __attribute__ ((noinline))
497 __u32 get_packet_hash(struct packet_description *pckt,
498 		      bool hash_16bytes)
499 {
500 	if (hash_16bytes)
501 		return jhash_2words(jhash(pckt->flow.srcv6, 16, 12),
502 				    pckt->flow.ports, 24);
503 	else
504 		return jhash_2words(pckt->flow.src, pckt->flow.ports,
505 				    24);
506 }
507 
508 __attribute__ ((noinline))
509 static bool get_packet_dst(struct real_definition **real,
510 			   struct packet_description *pckt,
511 			   struct vip_meta *vip_info,
512 			   bool is_ipv6, void *lru_map)
513 {
514 	struct real_pos_lru new_dst_lru = { };
515 	bool hash_16bytes = is_ipv6;
516 	__u32 *real_pos, hash, key;
517 	__u64 cur_time;
518 
519 	if (vip_info->flags & (1 << 2))
520 		hash_16bytes = 1;
521 	if (vip_info->flags & (1 << 3)) {
522 		pckt->flow.port16[0] = pckt->flow.port16[1];
523 		memset(pckt->flow.srcv6, 0, 16);
524 	}
525 	hash = get_packet_hash(pckt, hash_16bytes);
526 	if (hash != 0x358459b7 /* jhash of ipv4 packet */  &&
527 	    hash != 0x2f4bc6bb /* jhash of ipv6 packet */)
528 		return false;
529 	key = 2 * vip_info->vip_num + hash % 2;
530 	real_pos = bpf_map_lookup_elem(&ch_rings, &key);
531 	if (!real_pos)
532 		return false;
533 	key = *real_pos;
534 	*real = bpf_map_lookup_elem(&reals, &key);
535 	if (!(*real))
536 		return false;
537 	if (!(vip_info->flags & (1 << 1))) {
538 		__u32 conn_rate_key = 512 + 2;
539 		struct lb_stats *conn_rate_stats =
540 		    bpf_map_lookup_elem(&stats, &conn_rate_key);
541 
542 		if (!conn_rate_stats)
543 			return true;
544 		cur_time = bpf_ktime_get_ns();
545 		if ((cur_time - conn_rate_stats->v2) >> 32 > 0xffFFFF) {
546 			conn_rate_stats->v1 = 1;
547 			conn_rate_stats->v2 = cur_time;
548 		} else {
549 			conn_rate_stats->v1 += 1;
550 			if (conn_rate_stats->v1 >= 1)
551 				return true;
552 		}
553 		if (pckt->flow.proto == IPPROTO_UDP)
554 			new_dst_lru.atime = cur_time;
555 		new_dst_lru.pos = key;
556 		bpf_map_update_elem(lru_map, &pckt->flow, &new_dst_lru, 0);
557 	}
558 	return true;
559 }
560 
561 __attribute__ ((noinline))
562 static void connection_table_lookup(struct real_definition **real,
563 				    struct packet_description *pckt,
564 				    void *lru_map)
565 {
566 
567 	struct real_pos_lru *dst_lru;
568 	__u64 cur_time;
569 	__u32 key;
570 
571 	dst_lru = bpf_map_lookup_elem(lru_map, &pckt->flow);
572 	if (!dst_lru)
573 		return;
574 	if (pckt->flow.proto == IPPROTO_UDP) {
575 		cur_time = bpf_ktime_get_ns();
576 		if (cur_time - dst_lru->atime > 300000)
577 			return;
578 		dst_lru->atime = cur_time;
579 	}
580 	key = dst_lru->pos;
581 	*real = bpf_map_lookup_elem(&reals, &key);
582 }
583 
584 /* don't believe your eyes!
585  * below function has 6 arguments whereas bpf and llvm allow maximum of 5
586  * but since it's _static_ llvm can optimize one argument away
587  */
588 __attribute__ ((noinline))
589 static int process_l3_headers_v6(struct packet_description *pckt,
590 				 __u8 *protocol, __u64 off,
591 				 __u16 *pkt_bytes, void *data,
592 				 void *data_end)
593 {
594 	struct ipv6hdr *ip6h;
595 	__u64 iph_len;
596 	int action;
597 
598 	ip6h = data + off;
599 	if (ip6h + 1 > data_end)
600 		return XDP_DROP;
601 	iph_len = sizeof(struct ipv6hdr);
602 	*protocol = ip6h->nexthdr;
603 	pckt->flow.proto = *protocol;
604 	*pkt_bytes = bpf_ntohs(ip6h->payload_len);
605 	off += iph_len;
606 	if (*protocol == 45) {
607 		return XDP_DROP;
608 	} else if (*protocol == 59) {
609 		action = parse_icmpv6(data, data_end, off, pckt);
610 		if (action >= 0)
611 			return action;
612 	} else {
613 		memcpy(pckt->flow.srcv6, ip6h->saddr.in6_u.u6_addr32, 16);
614 		memcpy(pckt->flow.dstv6, ip6h->daddr.in6_u.u6_addr32, 16);
615 	}
616 	return -1;
617 }
618 
619 __attribute__ ((noinline))
620 static int process_l3_headers_v4(struct packet_description *pckt,
621 				 __u8 *protocol, __u64 off,
622 				 __u16 *pkt_bytes, void *data,
623 				 void *data_end)
624 {
625 	struct iphdr *iph;
626 	int action;
627 
628 	iph = data + off;
629 	if (iph + 1 > data_end)
630 		return XDP_DROP;
631 	if (iph->ihl != 5)
632 		return XDP_DROP;
633 	*protocol = iph->protocol;
634 	pckt->flow.proto = *protocol;
635 	*pkt_bytes = bpf_ntohs(iph->tot_len);
636 	off += 20;
637 	if (iph->frag_off & 65343)
638 		return XDP_DROP;
639 	if (*protocol == IPPROTO_ICMP) {
640 		action = parse_icmp(data, data_end, off, pckt);
641 		if (action >= 0)
642 			return action;
643 	} else {
644 		pckt->flow.src = iph->saddr;
645 		pckt->flow.dst = iph->daddr;
646 	}
647 	return -1;
648 }
649 
650 __attribute__ ((noinline))
651 static int process_packet(void *data, __u64 off, void *data_end,
652 			  bool is_ipv6, struct xdp_md *xdp)
653 {
654 
655 	struct real_definition *dst = NULL;
656 	struct packet_description pckt = { };
657 	struct vip_definition vip = { };
658 	struct lb_stats *data_stats;
659 	void *lru_map = &lru_cache;
660 	struct vip_meta *vip_info;
661 	__u32 lru_stats_key = 513;
662 	__u32 mac_addr_pos = 0;
663 	__u32 stats_key = 512;
664 	struct ctl_value *cval;
665 	__u16 pkt_bytes;
666 	__u8 protocol;
667 	__u32 vip_num;
668 	int action;
669 
670 	if (is_ipv6)
671 		action = process_l3_headers_v6(&pckt, &protocol, off,
672 					       &pkt_bytes, data, data_end);
673 	else
674 		action = process_l3_headers_v4(&pckt, &protocol, off,
675 					       &pkt_bytes, data, data_end);
676 	if (action >= 0)
677 		return action;
678 	protocol = pckt.flow.proto;
679 	if (protocol == IPPROTO_TCP) {
680 		if (!parse_tcp(data, data_end, is_ipv6, &pckt))
681 			return XDP_DROP;
682 	} else if (protocol == IPPROTO_UDP) {
683 		if (!parse_udp(data, data_end, is_ipv6, &pckt))
684 			return XDP_DROP;
685 	} else {
686 		return XDP_TX;
687 	}
688 
689 	if (is_ipv6)
690 		memcpy(vip.vipv6, pckt.flow.dstv6, 16);
691 	else
692 		vip.vip = pckt.flow.dst;
693 	vip.port = pckt.flow.port16[1];
694 	vip.proto = pckt.flow.proto;
695 	vip_info = bpf_map_lookup_elem(&vip_map, &vip);
696 	if (!vip_info) {
697 		vip.port = 0;
698 		vip_info = bpf_map_lookup_elem(&vip_map, &vip);
699 		if (!vip_info)
700 			return XDP_PASS;
701 		if (!(vip_info->flags & (1 << 4)))
702 			pckt.flow.port16[1] = 0;
703 	}
704 	if (data_end - data > 1400)
705 		return XDP_DROP;
706 	data_stats = bpf_map_lookup_elem(&stats, &stats_key);
707 	if (!data_stats)
708 		return XDP_DROP;
709 	data_stats->v1 += 1;
710 	if (!dst) {
711 		if (vip_info->flags & (1 << 0))
712 			pckt.flow.port16[0] = 0;
713 		if (!(pckt.flags & (1 << 1)) && !(vip_info->flags & (1 << 1)))
714 			connection_table_lookup(&dst, &pckt, lru_map);
715 		if (dst)
716 			goto out;
717 		if (pckt.flow.proto == IPPROTO_TCP) {
718 			struct lb_stats *lru_stats =
719 			    bpf_map_lookup_elem(&stats, &lru_stats_key);
720 
721 			if (!lru_stats)
722 				return XDP_DROP;
723 			if (pckt.flags & (1 << 1))
724 				lru_stats->v1 += 1;
725 			else
726 				lru_stats->v2 += 1;
727 		}
728 		if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6, lru_map))
729 			return XDP_DROP;
730 		data_stats->v2 += 1;
731 	}
732 out:
733 	cval = bpf_map_lookup_elem(&ctl_array, &mac_addr_pos);
734 	if (!cval)
735 		return XDP_DROP;
736 	if (dst->flags & (1 << 0)) {
737 		if (!encap_v6(xdp, cval, &pckt, dst, pkt_bytes))
738 			return XDP_DROP;
739 	} else {
740 		if (!encap_v4(xdp, cval, &pckt, dst, pkt_bytes))
741 			return XDP_DROP;
742 	}
743 	vip_num = vip_info->vip_num;
744 	data_stats = bpf_map_lookup_elem(&stats, &vip_num);
745 	if (!data_stats)
746 		return XDP_DROP;
747 	data_stats->v1 += 1;
748 	data_stats->v2 += pkt_bytes;
749 
750 	data = (void *)(long)xdp->data;
751 	data_end = (void *)(long)xdp->data_end;
752 	if (data + 4 > data_end)
753 		return XDP_DROP;
754 	*(u32 *)data = dst->dst;
755 	return XDP_DROP;
756 }
757 
758 SEC("xdp")
759 int balancer_ingress_v4(struct xdp_md *ctx)
760 {
761 	void *data = (void *)(long)ctx->data;
762 	void *data_end = (void *)(long)ctx->data_end;
763 	struct eth_hdr *eth = data;
764 	__u32 eth_proto;
765 	__u32 nh_off;
766 
767 	nh_off = sizeof(struct eth_hdr);
768 	if (data + nh_off > data_end)
769 		return XDP_DROP;
770 	eth_proto = bpf_ntohs(eth->eth_proto);
771 	if (eth_proto == ETH_P_IP)
772 		return process_packet(data, nh_off, data_end, 0, ctx);
773 	else
774 		return XDP_DROP;
775 }
776 
777 SEC("xdp")
778 int balancer_ingress_v6(struct xdp_md *ctx)
779 {
780 	void *data = (void *)(long)ctx->data;
781 	void *data_end = (void *)(long)ctx->data_end;
782 	struct eth_hdr *eth = data;
783 	__u32 eth_proto;
784 	__u32 nh_off;
785 
786 	nh_off = sizeof(struct eth_hdr);
787 	if (data + nh_off > data_end)
788 		return XDP_DROP;
789 	eth_proto = bpf_ntohs(eth->eth_proto);
790 	if (eth_proto == ETH_P_IPV6)
791 		return process_packet(data, nh_off, data_end, 1, ctx);
792 	else
793 		return XDP_DROP;
794 }
795 
796 char _license[] SEC("license") = "GPL";
797