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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 | // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2017 Facebook #include <stddef.h> #include <stdbool.h> #include <string.h> #include <linux/pkt_cls.h> #include <linux/bpf.h> #include <linux/in.h> #include <linux/if_ether.h> #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/icmp.h> #include <linux/icmpv6.h> #include <linux/tcp.h> #include <linux/udp.h> #include <bpf/bpf_helpers.h> #include "test_iptunnel_common.h" #include <bpf/bpf_endian.h> static __always_inline __u32 rol32(__u32 word, unsigned int shift) { return (word << shift) | (word >> ((-shift) & 31)); } /* copy paste of jhash from kernel sources to make sure llvm * can compile it into valid sequence of bpf instructions */ #define __jhash_mix(a, b, c) \ { \ a -= c; a ^= rol32(c, 4); c += b; \ b -= a; b ^= rol32(a, 6); a += c; \ c -= b; c ^= rol32(b, 8); b += a; \ a -= c; a ^= rol32(c, 16); c += b; \ b -= a; b ^= rol32(a, 19); a += c; \ c -= b; c ^= rol32(b, 4); b += a; \ } #define __jhash_final(a, b, c) \ { \ c ^= b; c -= rol32(b, 14); \ a ^= c; a -= rol32(c, 11); \ b ^= a; b -= rol32(a, 25); \ c ^= b; c -= rol32(b, 16); \ a ^= c; a -= rol32(c, 4); \ b ^= a; b -= rol32(a, 14); \ c ^= b; c -= rol32(b, 24); \ } #define JHASH_INITVAL 0xdeadbeef typedef unsigned int u32; static __noinline u32 jhash(const void *key, u32 length, u32 initval) { u32 a, b, c; const unsigned char *k = key; a = b = c = JHASH_INITVAL + length + initval; while (length > 12) { a += *(u32 *)(k); b += *(u32 *)(k + 4); c += *(u32 *)(k + 8); __jhash_mix(a, b, c); length -= 12; k += 12; } switch (length) { case 12: c += (u32)k[11]<<24; case 11: c += (u32)k[10]<<16; case 10: c += (u32)k[9]<<8; case 9: c += k[8]; case 8: b += (u32)k[7]<<24; case 7: b += (u32)k[6]<<16; case 6: b += (u32)k[5]<<8; case 5: b += k[4]; case 4: a += (u32)k[3]<<24; case 3: a += (u32)k[2]<<16; case 2: a += (u32)k[1]<<8; case 1: a += k[0]; __jhash_final(a, b, c); case 0: /* Nothing left to add */ break; } return c; } static __noinline u32 __jhash_nwords(u32 a, u32 b, u32 c, u32 initval) { a += initval; b += initval; c += initval; __jhash_final(a, b, c); return c; } static __noinline u32 jhash_2words(u32 a, u32 b, u32 initval) { return __jhash_nwords(a, b, 0, initval + JHASH_INITVAL + (2 << 2)); } #define PCKT_FRAGMENTED 65343 #define IPV4_HDR_LEN_NO_OPT 20 #define IPV4_PLUS_ICMP_HDR 28 #define IPV6_PLUS_ICMP_HDR 48 #define RING_SIZE 2 #define MAX_VIPS 12 #define MAX_REALS 5 #define CTL_MAP_SIZE 16 #define CH_RINGS_SIZE (MAX_VIPS * RING_SIZE) #define F_IPV6 (1 << 0) #define F_HASH_NO_SRC_PORT (1 << 0) #define F_ICMP (1 << 0) #define F_SYN_SET (1 << 1) struct packet_description { union { __be32 src; __be32 srcv6[4]; }; union { __be32 dst; __be32 dstv6[4]; }; union { __u32 ports; __u16 port16[2]; }; __u8 proto; __u8 flags; }; struct ctl_value { union { __u64 value; __u32 ifindex; __u8 mac[6]; }; }; struct vip_meta { __u32 flags; __u32 vip_num; }; struct real_definition { union { __be32 dst; __be32 dstv6[4]; }; __u8 flags; }; struct vip_stats { __u64 bytes; __u64 pkts; }; struct eth_hdr { unsigned char eth_dest[ETH_ALEN]; unsigned char eth_source[ETH_ALEN]; unsigned short eth_proto; }; struct { __uint(type, BPF_MAP_TYPE_HASH); __uint(max_entries, MAX_VIPS); __type(key, struct vip); __type(value, struct vip_meta); } vip_map SEC(".maps"); struct { __uint(type, BPF_MAP_TYPE_ARRAY); __uint(max_entries, CH_RINGS_SIZE); __type(key, __u32); __type(value, __u32); } ch_rings SEC(".maps"); struct { __uint(type, BPF_MAP_TYPE_ARRAY); __uint(max_entries, MAX_REALS); __type(key, __u32); __type(value, struct real_definition); } reals SEC(".maps"); struct { __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); __uint(max_entries, MAX_VIPS); __type(key, __u32); __type(value, struct vip_stats); } stats SEC(".maps"); struct { __uint(type, BPF_MAP_TYPE_ARRAY); __uint(max_entries, CTL_MAP_SIZE); __type(key, __u32); __type(value, struct ctl_value); } ctl_array SEC(".maps"); static __noinline __u32 get_packet_hash(struct packet_description *pckt, bool ipv6) { if (ipv6) return jhash_2words(jhash(pckt->srcv6, 16, MAX_VIPS), pckt->ports, CH_RINGS_SIZE); else return jhash_2words(pckt->src, pckt->ports, CH_RINGS_SIZE); } static __noinline bool get_packet_dst(struct real_definition **real, struct packet_description *pckt, struct vip_meta *vip_info, bool is_ipv6) { __u32 hash = get_packet_hash(pckt, is_ipv6); __u32 key = RING_SIZE * vip_info->vip_num + hash % RING_SIZE; __u32 *real_pos; if (hash != 0x358459b7 /* jhash of ipv4 packet */ && hash != 0x2f4bc6bb /* jhash of ipv6 packet */) return false; real_pos = bpf_map_lookup_elem(&ch_rings, &key); if (!real_pos) return false; key = *real_pos; *real = bpf_map_lookup_elem(&reals, &key); if (!(*real)) return false; return true; } static __noinline int parse_icmpv6(void *data, void *data_end, __u64 off, struct packet_description *pckt) { struct icmp6hdr *icmp_hdr; struct ipv6hdr *ip6h; icmp_hdr = data + off; if (icmp_hdr + 1 > data_end) return TC_ACT_SHOT; if (icmp_hdr->icmp6_type != ICMPV6_PKT_TOOBIG) return TC_ACT_OK; off += sizeof(struct icmp6hdr); ip6h = data + off; if (ip6h + 1 > data_end) return TC_ACT_SHOT; pckt->proto = ip6h->nexthdr; pckt->flags |= F_ICMP; memcpy(pckt->srcv6, ip6h->daddr.s6_addr32, 16); memcpy(pckt->dstv6, ip6h->saddr.s6_addr32, 16); return TC_ACT_UNSPEC; } static __noinline int parse_icmp(void *data, void *data_end, __u64 off, struct packet_description *pckt) { struct icmphdr *icmp_hdr; struct iphdr *iph; icmp_hdr = data + off; if (icmp_hdr + 1 > data_end) return TC_ACT_SHOT; if (icmp_hdr->type != ICMP_DEST_UNREACH || icmp_hdr->code != ICMP_FRAG_NEEDED) return TC_ACT_OK; off += sizeof(struct icmphdr); iph = data + off; if (iph + 1 > data_end) return TC_ACT_SHOT; if (iph->ihl != 5) return TC_ACT_SHOT; pckt->proto = iph->protocol; pckt->flags |= F_ICMP; pckt->src = iph->daddr; pckt->dst = iph->saddr; return TC_ACT_UNSPEC; } static __noinline bool parse_udp(void *data, __u64 off, void *data_end, struct packet_description *pckt) { struct udphdr *udp; udp = data + off; if (udp + 1 > data_end) return false; if (!(pckt->flags & F_ICMP)) { pckt->port16[0] = udp->source; pckt->port16[1] = udp->dest; } else { pckt->port16[0] = udp->dest; pckt->port16[1] = udp->source; } return true; } static __noinline bool parse_tcp(void *data, __u64 off, void *data_end, struct packet_description *pckt) { struct tcphdr *tcp; tcp = data + off; if (tcp + 1 > data_end) return false; if (tcp->syn) pckt->flags |= F_SYN_SET; if (!(pckt->flags & F_ICMP)) { pckt->port16[0] = tcp->source; pckt->port16[1] = tcp->dest; } else { pckt->port16[0] = tcp->dest; pckt->port16[1] = tcp->source; } return true; } static __noinline int process_packet(void *data, __u64 off, void *data_end, bool is_ipv6, struct __sk_buff *skb) { void *pkt_start = (void *)(long)skb->data; struct packet_description pckt = {}; struct eth_hdr *eth = pkt_start; struct bpf_tunnel_key tkey = {}; struct vip_stats *data_stats; struct real_definition *dst; struct vip_meta *vip_info; struct ctl_value *cval; __u32 v4_intf_pos = 1; __u32 v6_intf_pos = 2; struct ipv6hdr *ip6h; struct vip vip = {}; struct iphdr *iph; int tun_flag = 0; __u16 pkt_bytes; __u64 iph_len; __u32 ifindex; __u8 protocol; __u32 vip_num; int action; tkey.tunnel_ttl = 64; if (is_ipv6) { ip6h = data + off; if (ip6h + 1 > data_end) return TC_ACT_SHOT; iph_len = sizeof(struct ipv6hdr); protocol = ip6h->nexthdr; pckt.proto = protocol; pkt_bytes = bpf_ntohs(ip6h->payload_len); off += iph_len; if (protocol == IPPROTO_FRAGMENT) { return TC_ACT_SHOT; } else if (protocol == IPPROTO_ICMPV6) { action = parse_icmpv6(data, data_end, off, &pckt); if (action >= 0) return action; off += IPV6_PLUS_ICMP_HDR; } else { memcpy(pckt.srcv6, ip6h->saddr.s6_addr32, 16); memcpy(pckt.dstv6, ip6h->daddr.s6_addr32, 16); } } else { iph = data + off; if (iph + 1 > data_end) return TC_ACT_SHOT; if (iph->ihl != 5) return TC_ACT_SHOT; protocol = iph->protocol; pckt.proto = protocol; pkt_bytes = bpf_ntohs(iph->tot_len); off += IPV4_HDR_LEN_NO_OPT; if (iph->frag_off & PCKT_FRAGMENTED) return TC_ACT_SHOT; if (protocol == IPPROTO_ICMP) { action = parse_icmp(data, data_end, off, &pckt); if (action >= 0) return action; off += IPV4_PLUS_ICMP_HDR; } else { pckt.src = iph->saddr; pckt.dst = iph->daddr; } } protocol = pckt.proto; if (protocol == IPPROTO_TCP) { if (!parse_tcp(data, off, data_end, &pckt)) return TC_ACT_SHOT; } else if (protocol == IPPROTO_UDP) { if (!parse_udp(data, off, data_end, &pckt)) return TC_ACT_SHOT; } else { return TC_ACT_SHOT; } if (is_ipv6) memcpy(vip.daddr.v6, pckt.dstv6, 16); else vip.daddr.v4 = pckt.dst; vip.dport = pckt.port16[1]; vip.protocol = pckt.proto; vip_info = bpf_map_lookup_elem(&vip_map, &vip); if (!vip_info) { vip.dport = 0; vip_info = bpf_map_lookup_elem(&vip_map, &vip); if (!vip_info) return TC_ACT_SHOT; pckt.port16[1] = 0; } if (vip_info->flags & F_HASH_NO_SRC_PORT) pckt.port16[0] = 0; if (!get_packet_dst(&dst, &pckt, vip_info, is_ipv6)) return TC_ACT_SHOT; if (dst->flags & F_IPV6) { cval = bpf_map_lookup_elem(&ctl_array, &v6_intf_pos); if (!cval) return TC_ACT_SHOT; ifindex = cval->ifindex; memcpy(tkey.remote_ipv6, dst->dstv6, 16); tun_flag = BPF_F_TUNINFO_IPV6; } else { cval = bpf_map_lookup_elem(&ctl_array, &v4_intf_pos); if (!cval) return TC_ACT_SHOT; ifindex = cval->ifindex; tkey.remote_ipv4 = dst->dst; } vip_num = vip_info->vip_num; data_stats = bpf_map_lookup_elem(&stats, &vip_num); if (!data_stats) return TC_ACT_SHOT; data_stats->pkts++; data_stats->bytes += pkt_bytes; bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), tun_flag); *(u32 *)eth->eth_dest = tkey.remote_ipv4; return bpf_redirect(ifindex, 0); } SEC("tc") int balancer_ingress(struct __sk_buff *ctx) { void *data_end = (void *)(long)ctx->data_end; void *data = (void *)(long)ctx->data; struct eth_hdr *eth = data; __u32 eth_proto; __u32 nh_off; nh_off = sizeof(struct eth_hdr); if (data + nh_off > data_end) return TC_ACT_SHOT; eth_proto = eth->eth_proto; if (eth_proto == bpf_htons(ETH_P_IP)) return process_packet(data, nh_off, data_end, false, ctx); else if (eth_proto == bpf_htons(ETH_P_IPV6)) return process_packet(data, nh_off, data_end, true, ctx); else return TC_ACT_SHOT; } char _license[] SEC("license") = "GPL"; |