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#include "../kselftest.h"
56
57#define TOEPLITZ_KEY_MIN_LEN 40
58#define TOEPLITZ_KEY_MAX_LEN 60
59
60#define TOEPLITZ_STR_LEN(K) (((K) * 3) - 1) /* hex encoded: AA:BB:CC:...:ZZ */
61#define TOEPLITZ_STR_MIN_LEN TOEPLITZ_STR_LEN(TOEPLITZ_KEY_MIN_LEN)
62#define TOEPLITZ_STR_MAX_LEN TOEPLITZ_STR_LEN(TOEPLITZ_KEY_MAX_LEN)
63
64#define FOUR_TUPLE_MAX_LEN ((sizeof(struct in6_addr) * 2) + (sizeof(uint16_t) * 2))
65
66#define RSS_MAX_CPUS (1 << 16) /* real constraint is PACKET_FANOUT_MAX */
67
68#define RPS_MAX_CPUS 16UL /* must be a power of 2 */
69
70/* configuration options (cmdline arguments) */
71static uint16_t cfg_dport = 8000;
72static int cfg_family = AF_INET6;
73static char *cfg_ifname = "eth0";
74static int cfg_num_queues;
75static int cfg_num_rps_cpus;
76static bool cfg_sink;
77static int cfg_type = SOCK_STREAM;
78static int cfg_timeout_msec = 1000;
79static bool cfg_verbose;
80
81/* global vars */
82static int num_cpus;
83static int ring_block_nr;
84static int ring_block_sz;
85
86/* stats */
87static int frames_received;
88static int frames_nohash;
89static int frames_error;
90
91#define log_verbose(args...) do { if (cfg_verbose) fprintf(stderr, args); } while (0)
92
93/* tpacket ring */
94struct ring_state {
95 int fd;
96 char *mmap;
97 int idx;
98 int cpu;
99};
100
101static unsigned int rx_irq_cpus[RSS_MAX_CPUS]; /* map from rxq to cpu */
102static int rps_silo_to_cpu[RPS_MAX_CPUS];
103static unsigned char toeplitz_key[TOEPLITZ_KEY_MAX_LEN];
104static struct ring_state rings[RSS_MAX_CPUS];
105
106static inline uint32_t toeplitz(const unsigned char *four_tuple,
107 const unsigned char *key)
108{
109 int i, bit, ret = 0;
110 uint32_t key32;
111
112 key32 = ntohl(*((uint32_t *)key));
113 key += 4;
114
115 for (i = 0; i < FOUR_TUPLE_MAX_LEN; i++) {
116 for (bit = 7; bit >= 0; bit--) {
117 if (four_tuple[i] & (1 << bit))
118 ret ^= key32;
119
120 key32 <<= 1;
121 key32 |= !!(key[0] & (1 << bit));
122 }
123 key++;
124 }
125
126 return ret;
127}
128
129/* Compare computed cpu with arrival cpu from packet_fanout_cpu */
130static void verify_rss(uint32_t rx_hash, int cpu)
131{
132 int queue = rx_hash % cfg_num_queues;
133
134 log_verbose(" rxq %d (cpu %d)", queue, rx_irq_cpus[queue]);
135 if (rx_irq_cpus[queue] != cpu) {
136 log_verbose(". error: rss cpu mismatch (%d)", cpu);
137 frames_error++;
138 }
139}
140
141static void verify_rps(uint64_t rx_hash, int cpu)
142{
143 int silo = (rx_hash * cfg_num_rps_cpus) >> 32;
144
145 log_verbose(" silo %d (cpu %d)", silo, rps_silo_to_cpu[silo]);
146 if (rps_silo_to_cpu[silo] != cpu) {
147 log_verbose(". error: rps cpu mismatch (%d)", cpu);
148 frames_error++;
149 }
150}
151
152static void log_rxhash(int cpu, uint32_t rx_hash,
153 const char *addrs, int addr_len)
154{
155 char saddr[INET6_ADDRSTRLEN], daddr[INET6_ADDRSTRLEN];
156 uint16_t *ports;
157
158 if (!inet_ntop(cfg_family, addrs, saddr, sizeof(saddr)) ||
159 !inet_ntop(cfg_family, addrs + addr_len, daddr, sizeof(daddr)))
160 error(1, 0, "address parse error");
161
162 ports = (void *)addrs + (addr_len * 2);
163 log_verbose("cpu %d: rx_hash 0x%08x [saddr %s daddr %s sport %02hu dport %02hu]",
164 cpu, rx_hash, saddr, daddr,
165 ntohs(ports[0]), ntohs(ports[1]));
166}
167
168/* Compare computed rxhash with rxhash received from tpacket_v3 */
169static void verify_rxhash(const char *pkt, uint32_t rx_hash, int cpu)
170{
171 unsigned char four_tuple[FOUR_TUPLE_MAX_LEN] = {0};
172 uint32_t rx_hash_sw;
173 const char *addrs;
174 int addr_len;
175
176 if (cfg_family == AF_INET) {
177 addr_len = sizeof(struct in_addr);
178 addrs = pkt + offsetof(struct iphdr, saddr);
179 } else {
180 addr_len = sizeof(struct in6_addr);
181 addrs = pkt + offsetof(struct ip6_hdr, ip6_src);
182 }
183
184 memcpy(four_tuple, addrs, (addr_len * 2) + (sizeof(uint16_t) * 2));
185 rx_hash_sw = toeplitz(four_tuple, key: toeplitz_key);
186
187 if (cfg_verbose)
188 log_rxhash(cpu, rx_hash, addrs, addr_len);
189
190 if (rx_hash != rx_hash_sw) {
191 log_verbose(" != expected 0x%x\n", rx_hash_sw);
192 frames_error++;
193 return;
194 }
195
196 log_verbose(" OK");
197 if (cfg_num_queues)
198 verify_rss(rx_hash, cpu);
199 else if (cfg_num_rps_cpus)
200 verify_rps(rx_hash, cpu);
201 log_verbose("\n");
202}
203
204static char *recv_frame(const struct ring_state *ring, char *frame)
205{
206 struct tpacket3_hdr *hdr = (void *)frame;
207
208 if (hdr->hv1.tp_rxhash)
209 verify_rxhash(pkt: frame + hdr->tp_net, rx_hash: hdr->hv1.tp_rxhash,
210 cpu: ring->cpu);
211 else
212 frames_nohash++;
213
214 return frame + hdr->tp_next_offset;
215}
216
217/* A single TPACKET_V3 block can hold multiple frames */
218static bool recv_block(struct ring_state *ring)
219{
220 struct tpacket_block_desc *block;
221 char *frame;
222 int i;
223
224 block = (void *)(ring->mmap + ring->idx * ring_block_sz);
225 if (!(block->hdr.bh1.block_status & TP_STATUS_USER))
226 return false;
227
228 frame = (char *)block;
229 frame += block->hdr.bh1.offset_to_first_pkt;
230
231 for (i = 0; i < block->hdr.bh1.num_pkts; i++) {
232 frame = recv_frame(ring, frame);
233 frames_received++;
234 }
235
236 block->hdr.bh1.block_status = TP_STATUS_KERNEL;
237 ring->idx = (ring->idx + 1) % ring_block_nr;
238
239 return true;
240}
241
242/* simple test: sleep once unconditionally and then process all rings */
243static void process_rings(void)
244{
245 int i;
246
247 usleep(1000 * cfg_timeout_msec);
248
249 for (i = 0; i < num_cpus; i++)
250 do {} while (recv_block(ring: &rings[i]));
251
252 fprintf(stderr, "count: pass=%u nohash=%u fail=%u\n",
253 frames_received - frames_nohash - frames_error,
254 frames_nohash, frames_error);
255}
256
257static char *setup_ring(int fd)
258{
259 struct tpacket_req3 req3 = {0};
260 void *ring;
261
262 req3.tp_retire_blk_tov = cfg_timeout_msec / 8;
263 req3.tp_feature_req_word = TP_FT_REQ_FILL_RXHASH;
264
265 req3.tp_frame_size = 2048;
266 req3.tp_frame_nr = 1 << 10;
267 req3.tp_block_nr = 16;
268
269 req3.tp_block_size = req3.tp_frame_size * req3.tp_frame_nr;
270 req3.tp_block_size /= req3.tp_block_nr;
271
272 if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING, &req3, sizeof(req3)))
273 error(1, errno, "setsockopt PACKET_RX_RING");
274
275 ring_block_sz = req3.tp_block_size;
276 ring_block_nr = req3.tp_block_nr;
277
278 ring = mmap(0, req3.tp_block_size * req3.tp_block_nr,
279 PROT_READ | PROT_WRITE,
280 MAP_SHARED | MAP_LOCKED | MAP_POPULATE, fd, 0);
281 if (ring == MAP_FAILED)
282 error(1, 0, "mmap failed");
283
284 return ring;
285}
286
287static void __set_filter(int fd, int off_proto, uint8_t proto, int off_dport)
288{
289 struct sock_filter filter[] = {
290 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, SKF_AD_OFF + SKF_AD_PKTTYPE),
291 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, PACKET_HOST, 0, 4),
292 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, off_proto),
293 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, proto, 0, 2),
294 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, off_dport),
295 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, cfg_dport, 1, 0),
296 BPF_STMT(BPF_RET + BPF_K, 0),
297 BPF_STMT(BPF_RET + BPF_K, 0xFFFF),
298 };
299 struct sock_fprog prog = {};
300
301 prog.filter = filter;
302 prog.len = ARRAY_SIZE(filter);
303 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &prog, sizeof(prog)))
304 error(1, errno, "setsockopt filter");
305}
306
307/* filter on transport protocol and destination port */
308static void set_filter(int fd)
309{
310 const int off_dport = offsetof(struct tcphdr, dest); /* same for udp */
311 uint8_t proto;
312
313 proto = cfg_type == SOCK_STREAM ? IPPROTO_TCP : IPPROTO_UDP;
314 if (cfg_family == AF_INET)
315 __set_filter(fd, offsetof(struct iphdr, protocol), proto,
316 sizeof(struct iphdr) + off_dport);
317 else
318 __set_filter(fd, offsetof(struct ip6_hdr, ip6_nxt), proto,
319 sizeof(struct ip6_hdr) + off_dport);
320}
321
322/* drop everything: used temporarily during setup */
323static void set_filter_null(int fd)
324{
325 struct sock_filter filter[] = {
326 BPF_STMT(BPF_RET + BPF_K, 0),
327 };
328 struct sock_fprog prog = {};
329
330 prog.filter = filter;
331 prog.len = ARRAY_SIZE(filter);
332 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &prog, sizeof(prog)))
333 error(1, errno, "setsockopt filter");
334}
335
336static int create_ring(char **ring)
337{
338 struct fanout_args args = {
339 .id = 1,
340 .type_flags = PACKET_FANOUT_CPU,
341 .max_num_members = RSS_MAX_CPUS
342 };
343 struct sockaddr_ll ll = { 0 };
344 int fd, val;
345
346 fd = socket(PF_PACKET, SOCK_DGRAM, 0);
347 if (fd == -1)
348 error(1, errno, "socket creation failed");
349
350 val = TPACKET_V3;
351 if (setsockopt(fd, SOL_PACKET, PACKET_VERSION, &val, sizeof(val)))
352 error(1, errno, "setsockopt PACKET_VERSION");
353 *ring = setup_ring(fd);
354
355 /* block packets until all rings are added to the fanout group:
356 * else packets can arrive during setup and get misclassified
357 */
358 set_filter_null(fd);
359
360 ll.sll_family = AF_PACKET;
361 ll.sll_ifindex = if_nametoindex(cfg_ifname);
362 ll.sll_protocol = cfg_family == AF_INET ? htons(ETH_P_IP) :
363 htons(ETH_P_IPV6);
364 if (bind(fd, (void *)&ll, sizeof(ll)))
365 error(1, errno, "bind");
366
367 /* must come after bind: verifies all programs in group match */
368 if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &args, sizeof(args))) {
369 /* on failure, retry using old API if that is sufficient:
370 * it has a hard limit of 256 sockets, so only try if
371 * (a) only testing rxhash, not RSS or (b) <= 256 cpus.
372 * in this API, the third argument is left implicit.
373 */
374 if (cfg_num_queues || num_cpus > 256 ||
375 setsockopt(fd, SOL_PACKET, PACKET_FANOUT,
376 &args, sizeof(uint32_t)))
377 error(1, errno, "setsockopt PACKET_FANOUT cpu");
378 }
379
380 return fd;
381}
382
383/* setup inet(6) socket to blackhole the test traffic, if arg '-s' */
384static int setup_sink(void)
385{
386 int fd, val;
387
388 fd = socket(cfg_family, cfg_type, 0);
389 if (fd == -1)
390 error(1, errno, "socket %d.%d", cfg_family, cfg_type);
391
392 val = 1 << 20;
393 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &val, sizeof(val)))
394 error(1, errno, "setsockopt rcvbuf");
395
396 return fd;
397}
398
399static void setup_rings(void)
400{
401 int i;
402
403 for (i = 0; i < num_cpus; i++) {
404 rings[i].cpu = i;
405 rings[i].fd = create_ring(ring: &rings[i].mmap);
406 }
407
408 /* accept packets once all rings in the fanout group are up */
409 for (i = 0; i < num_cpus; i++)
410 set_filter(rings[i].fd);
411}
412
413static void cleanup_rings(void)
414{
415 int i;
416
417 for (i = 0; i < num_cpus; i++) {
418 if (munmap(rings[i].mmap, ring_block_nr * ring_block_sz))
419 error(1, errno, "munmap");
420 if (close(rings[i].fd))
421 error(1, errno, "close");
422 }
423}
424
425static void parse_cpulist(const char *arg)
426{
427 do {
428 rx_irq_cpus[cfg_num_queues++] = strtol(arg, NULL, 10);
429
430 arg = strchr(arg, ',');
431 if (!arg)
432 break;
433 arg++; // skip ','
434 } while (1);
435}
436
437static void show_cpulist(void)
438{
439 int i;
440
441 for (i = 0; i < cfg_num_queues; i++)
442 fprintf(stderr, "rxq %d: cpu %d\n", i, rx_irq_cpus[i]);
443}
444
445static void show_silos(void)
446{
447 int i;
448
449 for (i = 0; i < cfg_num_rps_cpus; i++)
450 fprintf(stderr, "silo %d: cpu %d\n", i, rps_silo_to_cpu[i]);
451}
452
453static void parse_toeplitz_key(const char *str, int slen, unsigned char *key)
454{
455 int i, ret, off;
456
457 if (slen < TOEPLITZ_STR_MIN_LEN ||
458 slen > TOEPLITZ_STR_MAX_LEN + 1)
459 error(1, 0, "invalid toeplitz key");
460
461 for (i = 0, off = 0; off < slen; i++, off += 3) {
462 ret = sscanf(str + off, "%hhx", &key[i]);
463 if (ret != 1)
464 error(1, 0, "key parse error at %d off %d len %d",
465 i, off, slen);
466 }
467}
468
469static void parse_rps_bitmap(const char *arg)
470{
471 unsigned long bitmap;
472 int i;
473
474 bitmap = strtoul(arg, NULL, 0);
475
476 if (bitmap & ~(RPS_MAX_CPUS - 1))
477 error(1, 0, "rps bitmap 0x%lx out of bounds 0..%lu",
478 bitmap, RPS_MAX_CPUS - 1);
479
480 for (i = 0; i < RPS_MAX_CPUS; i++)
481 if (bitmap & 1UL << i)
482 rps_silo_to_cpu[cfg_num_rps_cpus++] = i;
483}
484
485static void parse_opts(int argc, char **argv)
486{
487 static struct option long_options[] = {
488 {"dport", required_argument, 0, 'd'},
489 {"cpus", required_argument, 0, 'C'},
490 {"key", required_argument, 0, 'k'},
491 {"iface", required_argument, 0, 'i'},
492 {"ipv4", no_argument, 0, '4'},
493 {"ipv6", no_argument, 0, '6'},
494 {"sink", no_argument, 0, 's'},
495 {"tcp", no_argument, 0, 't'},
496 {"timeout", required_argument, 0, 'T'},
497 {"udp", no_argument, 0, 'u'},
498 {"verbose", no_argument, 0, 'v'},
499 {"rps", required_argument, 0, 'r'},
500 {0, 0, 0, 0}
501 };
502 bool have_toeplitz = false;
503 int index, c;
504
505 while ((c = getopt_long(argc, argv, "46C:d:i:k:r:stT:uv", long_options, &index)) != -1) {
506 switch (c) {
507 case '4':
508 cfg_family = AF_INET;
509 break;
510 case '6':
511 cfg_family = AF_INET6;
512 break;
513 case 'C':
514 parse_cpulist(optarg);
515 break;
516 case 'd':
517 cfg_dport = strtol(optarg, NULL, 0);
518 break;
519 case 'i':
520 cfg_ifname = optarg;
521 break;
522 case 'k':
523 parse_toeplitz_key(optarg, strlen(optarg),
524 toeplitz_key);
525 have_toeplitz = true;
526 break;
527 case 'r':
528 parse_rps_bitmap(optarg);
529 break;
530 case 's':
531 cfg_sink = true;
532 break;
533 case 't':
534 cfg_type = SOCK_STREAM;
535 break;
536 case 'T':
537 cfg_timeout_msec = strtol(optarg, NULL, 0);
538 break;
539 case 'u':
540 cfg_type = SOCK_DGRAM;
541 break;
542 case 'v':
543 cfg_verbose = true;
544 break;
545
546 default:
547 error(1, 0, "unknown option %c", optopt);
548 break;
549 }
550 }
551
552 if (!have_toeplitz)
553 error(1, 0, "Must supply rss key ('-k')");
554
555 num_cpus = get_nprocs();
556 if (num_cpus > RSS_MAX_CPUS)
557 error(1, 0, "increase RSS_MAX_CPUS");
558
559 if (cfg_num_queues && cfg_num_rps_cpus)
560 error(1, 0,
561 "Can't supply both RSS cpus ('-C') and RPS map ('-r')");
562 if (cfg_verbose) {
563 show_cpulist();
564 show_silos();
565 }
566}
567
568int main(int argc, char **argv)
569{
570 const int min_tests = 10;
571 int fd_sink = -1;
572
573 parse_opts(argc, argv);
574
575 if (cfg_sink)
576 fd_sink = setup_sink();
577
578 setup_rings();
579 process_rings();
580 cleanup_rings();
581
582 if (cfg_sink && close(fd_sink))
583 error(1, errno, "close sink");
584
585 if (frames_received - frames_nohash < min_tests)
586 error(1, 0, "too few frames for verification");
587
588 return frames_error;
589}
590

source code of linux/tools/testing/selftests/net/toeplitz.c