1 // SPDX-License-Identifier: GPL-2.0 2 /* Toeplitz test 3 * 4 * 1. Read packets and their rx_hash using PF_PACKET/TPACKET_V3 5 * 2. Compute the rx_hash in software based on the packet contents 6 * 3. Compare the two 7 * 8 * Optionally, either '-C $rx_irq_cpu_list' or '-r $rps_bitmap' may be given. 9 * 10 * If '-C $rx_irq_cpu_list' is given, also 11 * 12 * 4. Identify the cpu on which the packet arrived with PACKET_FANOUT_CPU 13 * 5. Compute the rxqueue that RSS would select based on this rx_hash 14 * 6. Using the $rx_irq_cpu_list map, identify the arriving cpu based on rxq irq 15 * 7. Compare the cpus from 4 and 6 16 * 17 * Else if '-r $rps_bitmap' is given, also 18 * 19 * 4. Identify the cpu on which the packet arrived with PACKET_FANOUT_CPU 20 * 5. Compute the cpu that RPS should select based on rx_hash and $rps_bitmap 21 * 6. Compare the cpus from 4 and 5 22 */ 23 24 #define _GNU_SOURCE 25 26 #include <arpa/inet.h> 27 #include <errno.h> 28 #include <error.h> 29 #include <fcntl.h> 30 #include <getopt.h> 31 #include <linux/filter.h> 32 #include <linux/if_ether.h> 33 #include <linux/if_packet.h> 34 #include <net/if.h> 35 #include <netdb.h> 36 #include <netinet/ip.h> 37 #include <netinet/ip6.h> 38 #include <netinet/tcp.h> 39 #include <netinet/udp.h> 40 #include <poll.h> 41 #include <stdbool.h> 42 #include <stddef.h> 43 #include <stdint.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <sys/mman.h> 48 #include <sys/socket.h> 49 #include <sys/stat.h> 50 #include <sys/sysinfo.h> 51 #include <sys/time.h> 52 #include <sys/types.h> 53 #include <unistd.h> 54 55 #define TOEPLITZ_KEY_MIN_LEN 40 56 #define TOEPLITZ_KEY_MAX_LEN 60 57 58 #define TOEPLITZ_STR_LEN(K) (((K) * 3) - 1) /* hex encoded: AA:BB:CC:...:ZZ */ 59 #define TOEPLITZ_STR_MIN_LEN TOEPLITZ_STR_LEN(TOEPLITZ_KEY_MIN_LEN) 60 #define TOEPLITZ_STR_MAX_LEN TOEPLITZ_STR_LEN(TOEPLITZ_KEY_MAX_LEN) 61 62 #define FOUR_TUPLE_MAX_LEN ((sizeof(struct in6_addr) * 2) + (sizeof(uint16_t) * 2)) 63 64 #define RSS_MAX_CPUS (1 << 16) /* real constraint is PACKET_FANOUT_MAX */ 65 66 #define RPS_MAX_CPUS 16UL /* must be a power of 2 */ 67 68 /* configuration options (cmdline arguments) */ 69 static uint16_t cfg_dport = 8000; 70 static int cfg_family = AF_INET6; 71 static char *cfg_ifname = "eth0"; 72 static int cfg_num_queues; 73 static int cfg_num_rps_cpus; 74 static bool cfg_sink; 75 static int cfg_type = SOCK_STREAM; 76 static int cfg_timeout_msec = 1000; 77 static bool cfg_verbose; 78 79 /* global vars */ 80 static int num_cpus; 81 static int ring_block_nr; 82 static int ring_block_sz; 83 84 /* stats */ 85 static int frames_received; 86 static int frames_nohash; 87 static int frames_error; 88 89 #define log_verbose(args...) do { if (cfg_verbose) fprintf(stderr, args); } while (0) 90 91 /* tpacket ring */ 92 struct ring_state { 93 int fd; 94 char *mmap; 95 int idx; 96 int cpu; 97 }; 98 99 static unsigned int rx_irq_cpus[RSS_MAX_CPUS]; /* map from rxq to cpu */ 100 static int rps_silo_to_cpu[RPS_MAX_CPUS]; 101 static unsigned char toeplitz_key[TOEPLITZ_KEY_MAX_LEN]; 102 static struct ring_state rings[RSS_MAX_CPUS]; 103 104 static inline uint32_t toeplitz(const unsigned char *four_tuple, 105 const unsigned char *key) 106 { 107 int i, bit, ret = 0; 108 uint32_t key32; 109 110 key32 = ntohl(*((uint32_t *)key)); 111 key += 4; 112 113 for (i = 0; i < FOUR_TUPLE_MAX_LEN; i++) { 114 for (bit = 7; bit >= 0; bit--) { 115 if (four_tuple[i] & (1 << bit)) 116 ret ^= key32; 117 118 key32 <<= 1; 119 key32 |= !!(key[0] & (1 << bit)); 120 } 121 key++; 122 } 123 124 return ret; 125 } 126 127 /* Compare computed cpu with arrival cpu from packet_fanout_cpu */ 128 static void verify_rss(uint32_t rx_hash, int cpu) 129 { 130 int queue = rx_hash % cfg_num_queues; 131 132 log_verbose(" rxq %d (cpu %d)", queue, rx_irq_cpus[queue]); 133 if (rx_irq_cpus[queue] != cpu) { 134 log_verbose(". error: rss cpu mismatch (%d)", cpu); 135 frames_error++; 136 } 137 } 138 139 static void verify_rps(uint64_t rx_hash, int cpu) 140 { 141 int silo = (rx_hash * cfg_num_rps_cpus) >> 32; 142 143 log_verbose(" silo %d (cpu %d)", silo, rps_silo_to_cpu[silo]); 144 if (rps_silo_to_cpu[silo] != cpu) { 145 log_verbose(". error: rps cpu mismatch (%d)", cpu); 146 frames_error++; 147 } 148 } 149 150 static void log_rxhash(int cpu, uint32_t rx_hash, 151 const char *addrs, int addr_len) 152 { 153 char saddr[INET6_ADDRSTRLEN], daddr[INET6_ADDRSTRLEN]; 154 uint16_t *ports; 155 156 if (!inet_ntop(cfg_family, addrs, saddr, sizeof(saddr)) || 157 !inet_ntop(cfg_family, addrs + addr_len, daddr, sizeof(daddr))) 158 error(1, 0, "address parse error"); 159 160 ports = (void *)addrs + (addr_len * 2); 161 log_verbose("cpu %d: rx_hash 0x%08x [saddr %s daddr %s sport %02hu dport %02hu]", 162 cpu, rx_hash, saddr, daddr, 163 ntohs(ports[0]), ntohs(ports[1])); 164 } 165 166 /* Compare computed rxhash with rxhash received from tpacket_v3 */ 167 static void verify_rxhash(const char *pkt, uint32_t rx_hash, int cpu) 168 { 169 unsigned char four_tuple[FOUR_TUPLE_MAX_LEN] = {0}; 170 uint32_t rx_hash_sw; 171 const char *addrs; 172 int addr_len; 173 174 if (cfg_family == AF_INET) { 175 addr_len = sizeof(struct in_addr); 176 addrs = pkt + offsetof(struct iphdr, saddr); 177 } else { 178 addr_len = sizeof(struct in6_addr); 179 addrs = pkt + offsetof(struct ip6_hdr, ip6_src); 180 } 181 182 memcpy(four_tuple, addrs, (addr_len * 2) + (sizeof(uint16_t) * 2)); 183 rx_hash_sw = toeplitz(four_tuple, toeplitz_key); 184 185 if (cfg_verbose) 186 log_rxhash(cpu, rx_hash, addrs, addr_len); 187 188 if (rx_hash != rx_hash_sw) { 189 log_verbose(" != expected 0x%x\n", rx_hash_sw); 190 frames_error++; 191 return; 192 } 193 194 log_verbose(" OK"); 195 if (cfg_num_queues) 196 verify_rss(rx_hash, cpu); 197 else if (cfg_num_rps_cpus) 198 verify_rps(rx_hash, cpu); 199 log_verbose("\n"); 200 } 201 202 static char *recv_frame(const struct ring_state *ring, char *frame) 203 { 204 struct tpacket3_hdr *hdr = (void *)frame; 205 206 if (hdr->hv1.tp_rxhash) 207 verify_rxhash(frame + hdr->tp_net, hdr->hv1.tp_rxhash, 208 ring->cpu); 209 else 210 frames_nohash++; 211 212 return frame + hdr->tp_next_offset; 213 } 214 215 /* A single TPACKET_V3 block can hold multiple frames */ 216 static void recv_block(struct ring_state *ring) 217 { 218 struct tpacket_block_desc *block; 219 char *frame; 220 int i; 221 222 block = (void *)(ring->mmap + ring->idx * ring_block_sz); 223 if (!(block->hdr.bh1.block_status & TP_STATUS_USER)) 224 return; 225 226 frame = (char *)block; 227 frame += block->hdr.bh1.offset_to_first_pkt; 228 229 for (i = 0; i < block->hdr.bh1.num_pkts; i++) { 230 frame = recv_frame(ring, frame); 231 frames_received++; 232 } 233 234 block->hdr.bh1.block_status = TP_STATUS_KERNEL; 235 ring->idx = (ring->idx + 1) % ring_block_nr; 236 } 237 238 /* simple test: sleep once unconditionally and then process all rings */ 239 static void process_rings(void) 240 { 241 int i; 242 243 usleep(1000 * cfg_timeout_msec); 244 245 for (i = 0; i < num_cpus; i++) 246 recv_block(&rings[i]); 247 248 fprintf(stderr, "count: pass=%u nohash=%u fail=%u\n", 249 frames_received - frames_nohash - frames_error, 250 frames_nohash, frames_error); 251 } 252 253 static char *setup_ring(int fd) 254 { 255 struct tpacket_req3 req3 = {0}; 256 void *ring; 257 258 req3.tp_retire_blk_tov = cfg_timeout_msec; 259 req3.tp_feature_req_word = TP_FT_REQ_FILL_RXHASH; 260 261 req3.tp_frame_size = 2048; 262 req3.tp_frame_nr = 1 << 10; 263 req3.tp_block_nr = 2; 264 265 req3.tp_block_size = req3.tp_frame_size * req3.tp_frame_nr; 266 req3.tp_block_size /= req3.tp_block_nr; 267 268 if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING, &req3, sizeof(req3))) 269 error(1, errno, "setsockopt PACKET_RX_RING"); 270 271 ring_block_sz = req3.tp_block_size; 272 ring_block_nr = req3.tp_block_nr; 273 274 ring = mmap(0, req3.tp_block_size * req3.tp_block_nr, 275 PROT_READ | PROT_WRITE, 276 MAP_SHARED | MAP_LOCKED | MAP_POPULATE, fd, 0); 277 if (ring == MAP_FAILED) 278 error(1, 0, "mmap failed"); 279 280 return ring; 281 } 282 283 static void __set_filter(int fd, int off_proto, uint8_t proto, int off_dport) 284 { 285 struct sock_filter filter[] = { 286 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, SKF_AD_OFF + SKF_AD_PKTTYPE), 287 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, PACKET_HOST, 0, 4), 288 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, off_proto), 289 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, proto, 0, 2), 290 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, off_dport), 291 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, cfg_dport, 1, 0), 292 BPF_STMT(BPF_RET + BPF_K, 0), 293 BPF_STMT(BPF_RET + BPF_K, 0xFFFF), 294 }; 295 struct sock_fprog prog = {}; 296 297 prog.filter = filter; 298 prog.len = sizeof(filter) / sizeof(struct sock_filter); 299 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &prog, sizeof(prog))) 300 error(1, errno, "setsockopt filter"); 301 } 302 303 /* filter on transport protocol and destination port */ 304 static void set_filter(int fd) 305 { 306 const int off_dport = offsetof(struct tcphdr, dest); /* same for udp */ 307 uint8_t proto; 308 309 proto = cfg_type == SOCK_STREAM ? IPPROTO_TCP : IPPROTO_UDP; 310 if (cfg_family == AF_INET) 311 __set_filter(fd, offsetof(struct iphdr, protocol), proto, 312 sizeof(struct iphdr) + off_dport); 313 else 314 __set_filter(fd, offsetof(struct ip6_hdr, ip6_nxt), proto, 315 sizeof(struct ip6_hdr) + off_dport); 316 } 317 318 /* drop everything: used temporarily during setup */ 319 static void set_filter_null(int fd) 320 { 321 struct sock_filter filter[] = { 322 BPF_STMT(BPF_RET + BPF_K, 0), 323 }; 324 struct sock_fprog prog = {}; 325 326 prog.filter = filter; 327 prog.len = sizeof(filter) / sizeof(struct sock_filter); 328 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &prog, sizeof(prog))) 329 error(1, errno, "setsockopt filter"); 330 } 331 332 static int create_ring(char **ring) 333 { 334 struct fanout_args args = { 335 .id = 1, 336 .type_flags = PACKET_FANOUT_CPU, 337 .max_num_members = RSS_MAX_CPUS 338 }; 339 struct sockaddr_ll ll = { 0 }; 340 int fd, val; 341 342 fd = socket(PF_PACKET, SOCK_DGRAM, 0); 343 if (fd == -1) 344 error(1, errno, "socket creation failed"); 345 346 val = TPACKET_V3; 347 if (setsockopt(fd, SOL_PACKET, PACKET_VERSION, &val, sizeof(val))) 348 error(1, errno, "setsockopt PACKET_VERSION"); 349 *ring = setup_ring(fd); 350 351 /* block packets until all rings are added to the fanout group: 352 * else packets can arrive during setup and get misclassified 353 */ 354 set_filter_null(fd); 355 356 ll.sll_family = AF_PACKET; 357 ll.sll_ifindex = if_nametoindex(cfg_ifname); 358 ll.sll_protocol = cfg_family == AF_INET ? htons(ETH_P_IP) : 359 htons(ETH_P_IPV6); 360 if (bind(fd, (void *)&ll, sizeof(ll))) 361 error(1, errno, "bind"); 362 363 /* must come after bind: verifies all programs in group match */ 364 if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &args, sizeof(args))) { 365 /* on failure, retry using old API if that is sufficient: 366 * it has a hard limit of 256 sockets, so only try if 367 * (a) only testing rxhash, not RSS or (b) <= 256 cpus. 368 * in this API, the third argument is left implicit. 369 */ 370 if (cfg_num_queues || num_cpus > 256 || 371 setsockopt(fd, SOL_PACKET, PACKET_FANOUT, 372 &args, sizeof(uint32_t))) 373 error(1, errno, "setsockopt PACKET_FANOUT cpu"); 374 } 375 376 return fd; 377 } 378 379 /* setup inet(6) socket to blackhole the test traffic, if arg '-s' */ 380 static int setup_sink(void) 381 { 382 int fd, val; 383 384 fd = socket(cfg_family, cfg_type, 0); 385 if (fd == -1) 386 error(1, errno, "socket %d.%d", cfg_family, cfg_type); 387 388 val = 1 << 20; 389 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &val, sizeof(val))) 390 error(1, errno, "setsockopt rcvbuf"); 391 392 return fd; 393 } 394 395 static void setup_rings(void) 396 { 397 int i; 398 399 for (i = 0; i < num_cpus; i++) { 400 rings[i].cpu = i; 401 rings[i].fd = create_ring(&rings[i].mmap); 402 } 403 404 /* accept packets once all rings in the fanout group are up */ 405 for (i = 0; i < num_cpus; i++) 406 set_filter(rings[i].fd); 407 } 408 409 static void cleanup_rings(void) 410 { 411 int i; 412 413 for (i = 0; i < num_cpus; i++) { 414 if (munmap(rings[i].mmap, ring_block_nr * ring_block_sz)) 415 error(1, errno, "munmap"); 416 if (close(rings[i].fd)) 417 error(1, errno, "close"); 418 } 419 } 420 421 static void parse_cpulist(const char *arg) 422 { 423 do { 424 rx_irq_cpus[cfg_num_queues++] = strtol(arg, NULL, 10); 425 426 arg = strchr(arg, ','); 427 if (!arg) 428 break; 429 arg++; // skip ',' 430 } while (1); 431 } 432 433 static void show_cpulist(void) 434 { 435 int i; 436 437 for (i = 0; i < cfg_num_queues; i++) 438 fprintf(stderr, "rxq %d: cpu %d\n", i, rx_irq_cpus[i]); 439 } 440 441 static void show_silos(void) 442 { 443 int i; 444 445 for (i = 0; i < cfg_num_rps_cpus; i++) 446 fprintf(stderr, "silo %d: cpu %d\n", i, rps_silo_to_cpu[i]); 447 } 448 449 static void parse_toeplitz_key(const char *str, int slen, unsigned char *key) 450 { 451 int i, ret, off; 452 453 if (slen < TOEPLITZ_STR_MIN_LEN || 454 slen > TOEPLITZ_STR_MAX_LEN + 1) 455 error(1, 0, "invalid toeplitz key"); 456 457 for (i = 0, off = 0; off < slen; i++, off += 3) { 458 ret = sscanf(str + off, "%hhx", &key[i]); 459 if (ret != 1) 460 error(1, 0, "key parse error at %d off %d len %d", 461 i, off, slen); 462 } 463 } 464 465 static void parse_rps_bitmap(const char *arg) 466 { 467 unsigned long bitmap; 468 int i; 469 470 bitmap = strtoul(arg, NULL, 0); 471 472 if (bitmap & ~(RPS_MAX_CPUS - 1)) 473 error(1, 0, "rps bitmap 0x%lx out of bounds 0..%lu", 474 bitmap, RPS_MAX_CPUS - 1); 475 476 for (i = 0; i < RPS_MAX_CPUS; i++) 477 if (bitmap & 1UL << i) 478 rps_silo_to_cpu[cfg_num_rps_cpus++] = i; 479 } 480 481 static void parse_opts(int argc, char **argv) 482 { 483 static struct option long_options[] = { 484 {"dport", required_argument, 0, 'd'}, 485 {"cpus", required_argument, 0, 'C'}, 486 {"key", required_argument, 0, 'k'}, 487 {"iface", required_argument, 0, 'i'}, 488 {"ipv4", no_argument, 0, '4'}, 489 {"ipv6", no_argument, 0, '6'}, 490 {"sink", no_argument, 0, 's'}, 491 {"tcp", no_argument, 0, 't'}, 492 {"timeout", required_argument, 0, 'T'}, 493 {"udp", no_argument, 0, 'u'}, 494 {"verbose", no_argument, 0, 'v'}, 495 {"rps", required_argument, 0, 'r'}, 496 {0, 0, 0, 0} 497 }; 498 bool have_toeplitz = false; 499 int index, c; 500 501 while ((c = getopt_long(argc, argv, "46C:d:i:k:r:stT:u:v", long_options, &index)) != -1) { 502 switch (c) { 503 case '4': 504 cfg_family = AF_INET; 505 break; 506 case '6': 507 cfg_family = AF_INET6; 508 break; 509 case 'C': 510 parse_cpulist(optarg); 511 break; 512 case 'd': 513 cfg_dport = strtol(optarg, NULL, 0); 514 break; 515 case 'i': 516 cfg_ifname = optarg; 517 break; 518 case 'k': 519 parse_toeplitz_key(optarg, strlen(optarg), 520 toeplitz_key); 521 have_toeplitz = true; 522 break; 523 case 'r': 524 parse_rps_bitmap(optarg); 525 break; 526 case 's': 527 cfg_sink = true; 528 break; 529 case 't': 530 cfg_type = SOCK_STREAM; 531 break; 532 case 'T': 533 cfg_timeout_msec = strtol(optarg, NULL, 0); 534 break; 535 case 'u': 536 cfg_type = SOCK_DGRAM; 537 break; 538 case 'v': 539 cfg_verbose = true; 540 break; 541 542 default: 543 error(1, 0, "unknown option %c", optopt); 544 break; 545 } 546 } 547 548 if (!have_toeplitz) 549 error(1, 0, "Must supply rss key ('-k')"); 550 551 num_cpus = get_nprocs(); 552 if (num_cpus > RSS_MAX_CPUS) 553 error(1, 0, "increase RSS_MAX_CPUS"); 554 555 if (cfg_num_queues && cfg_num_rps_cpus) 556 error(1, 0, 557 "Can't supply both RSS cpus ('-C') and RPS map ('-r')"); 558 if (cfg_verbose) { 559 show_cpulist(); 560 show_silos(); 561 } 562 } 563 564 int main(int argc, char **argv) 565 { 566 const int min_tests = 10; 567 int fd_sink = -1; 568 569 parse_opts(argc, argv); 570 571 if (cfg_sink) 572 fd_sink = setup_sink(); 573 574 setup_rings(); 575 process_rings(); 576 cleanup_rings(); 577 578 if (cfg_sink && close(fd_sink)) 579 error(1, errno, "close sink"); 580 581 if (frames_received - frames_nohash < min_tests) 582 error(1, 0, "too few frames for verification"); 583 584 return frames_error; 585 } 586