psock_fanout.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright 2013 Google Inc.
  4 * Author: Willem de Bruijn (willemb@google.com)
  5 *
  6 * A basic test of packet socket fanout behavior.
  7 *
  8 * Control:
  9 * - create fanout fails as expected with illegal flag combinations
 10 * - join   fanout fails as expected with diverging types or flags
 11 *
 12 * Datapath:
 13 *   Open a pair of packet sockets and a pair of INET sockets, send a known
 14 *   number of packets across the two INET sockets and count the number of
 15 *   packets enqueued onto the two packet sockets.
 16 *
 17 *   The test currently runs for
 18 *   - PACKET_FANOUT_HASH
 19 *   - PACKET_FANOUT_HASH with PACKET_FANOUT_FLAG_ROLLOVER
 20 *   - PACKET_FANOUT_LB
 21 *   - PACKET_FANOUT_CPU
 22 *   - PACKET_FANOUT_ROLLOVER
 23 *   - PACKET_FANOUT_CBPF
 24 *   - PACKET_FANOUT_EBPF
 25 *
 26 * Todo:
 27 * - functionality: PACKET_FANOUT_FLAG_DEFRAG
 28 */
 29
 30#define _GNU_SOURCE		/* for sched_setaffinity */
 31
 32#include <arpa/inet.h>
 33#include <errno.h>
 34#include <fcntl.h>
 35#include <linux/unistd.h>	/* for __NR_bpf */
 36#include <linux/filter.h>
 37#include <linux/bpf.h>
 38#include <linux/if_packet.h>
 39#include <net/if.h>
 40#include <net/ethernet.h>
 41#include <netinet/ip.h>
 42#include <netinet/udp.h>
 43#include <poll.h>
 44#include <sched.h>
 45#include <stdint.h>
 46#include <stdio.h>
 47#include <stdlib.h>
 48#include <string.h>
 49#include <sys/mman.h>
 50#include <sys/socket.h>
 51#include <sys/ioctl.h>
 52#include <sys/stat.h>
 53#include <sys/types.h>
 54#include <unistd.h>
 55
 56#include "psock_lib.h"
 57#include "kselftest.h"
 58
 59#define RING_NUM_FRAMES			20
 60
 61static uint32_t cfg_max_num_members;
 62
 63static void loopback_set_up_down(int state_up)
 64{
 65	struct ifreq ifreq = {};
 66	int fd, err;
 67
 68	fd = socket(AF_PACKET, SOCK_RAW, 0);
 69	if (fd < 0) {
 70		perror("socket loopback");
 71		exit(1);
 72	}
 73	strcpy(ifreq.ifr_name, "lo");
 74	err = ioctl(fd, SIOCGIFFLAGS, &ifreq);
 75	if (err) {
 76		perror("SIOCGIFFLAGS");
 77		exit(1);
 78	}
 79	if (state_up != !!(ifreq.ifr_flags & IFF_UP)) {
 80		ifreq.ifr_flags ^= IFF_UP;
 81		err = ioctl(fd, SIOCSIFFLAGS, &ifreq);
 82		if (err) {
 83			perror("SIOCSIFFLAGS");
 84			exit(1);
 85		}
 86	}
 87	close(fd);
 88}
 89
 90/* Open a socket in a given fanout mode.
 91 * @return -1 if mode is bad, a valid socket otherwise */
 92static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)
 93{
 94	struct sockaddr_ll addr = {0};
 95	struct fanout_args args;
 96	int fd, val, err;
 97
 98	fd = socket(PF_PACKET, SOCK_RAW, 0);
 99	if (fd < 0) {
100		perror("socket packet");
101		exit(1);
102	}
103
104	pair_udp_setfilter(fd);
105
106	addr.sll_family = AF_PACKET;
107	addr.sll_protocol = htons(ETH_P_IP);
108	addr.sll_ifindex = if_nametoindex("lo");
109	if (addr.sll_ifindex == 0) {
110		perror("if_nametoindex");
111		exit(1);
112	}
113	if (bind(fd, (void *) &addr, sizeof(addr))) {
114		perror("bind packet");
115		exit(1);
116	}
117
118	if (cfg_max_num_members) {
119		args.id = group_id;
120		args.type_flags = typeflags;
121		args.max_num_members = cfg_max_num_members;
122		err = setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &args,
123				 sizeof(args));
124	} else {
125		val = (((int) typeflags) << 16) | group_id;
126		err = setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &val,
127				 sizeof(val));
128	}
129	if (err) {
130		if (close(fd)) {
131			perror("close packet");
132			exit(1);
133		}
134		return -1;
135	}
136
137	return fd;
138}
139
140static void sock_fanout_set_cbpf(int fd)
141{
142	struct sock_filter bpf_filter[] = {
143		BPF_STMT(BPF_LD | BPF_B | BPF_ABS, 80),	      /* ldb [80] */
144		BPF_STMT(BPF_RET | BPF_A, 0),		      /* ret A */
145	};
146	struct sock_fprog bpf_prog;
147
148	bpf_prog.filter = bpf_filter;
149	bpf_prog.len = ARRAY_SIZE(bpf_filter);
150
151	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &bpf_prog,
152		       sizeof(bpf_prog))) {
153		perror("fanout data cbpf");
154		exit(1);
155	}
156}
157
158static void sock_fanout_getopts(int fd, uint16_t *typeflags, uint16_t *group_id)
159{
160	int sockopt;
161	socklen_t sockopt_len = sizeof(sockopt);
162
163	if (getsockopt(fd, SOL_PACKET, PACKET_FANOUT,
164		       &sockopt, &sockopt_len)) {
165		perror("failed to getsockopt");
166		exit(1);
167	}
168	*typeflags = sockopt >> 16;
169	*group_id = sockopt & 0xfffff;
170}
171
172static void sock_fanout_set_ebpf(int fd)
173{
174	static char log_buf[65536];
175
176	const int len_off = __builtin_offsetof(struct __sk_buff, len);
177	struct bpf_insn prog[] = {
178		{ BPF_ALU64 | BPF_MOV | BPF_X,   6, 1, 0, 0 },
179		{ BPF_LDX   | BPF_W   | BPF_MEM, 0, 6, len_off, 0 },
180		{ BPF_JMP   | BPF_JGE | BPF_K,   0, 0, 1, DATA_LEN },
181		{ BPF_JMP   | BPF_JA  | BPF_K,   0, 0, 4, 0 },
182		{ BPF_LD    | BPF_B   | BPF_ABS, 0, 0, 0, 0x50 },
183		{ BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 2, DATA_CHAR },
184		{ BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 1, DATA_CHAR_1 },
185		{ BPF_ALU   | BPF_MOV | BPF_K,   0, 0, 0, 0 },
186		{ BPF_JMP   | BPF_EXIT,          0, 0, 0, 0 }
187	};
188	union bpf_attr attr;
189	int pfd;
190
191	memset(&attr, 0, sizeof(attr));
192	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
193	attr.insns = (unsigned long) prog;
194	attr.insn_cnt = ARRAY_SIZE(prog);
195	attr.license = (unsigned long) "GPL";
196	attr.log_buf = (unsigned long) log_buf;
197	attr.log_size = sizeof(log_buf);
198	attr.log_level = 1;
199
200	pfd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
201	if (pfd < 0) {
202		perror("bpf");
203		fprintf(stderr, "bpf verifier:\n%s\n", log_buf);
204		exit(1);
205	}
206
207	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &pfd, sizeof(pfd))) {
208		perror("fanout data ebpf");
209		exit(1);
210	}
211
212	if (close(pfd)) {
213		perror("close ebpf");
214		exit(1);
215	}
216}
217
218static char *sock_fanout_open_ring(int fd)
219{
220	struct tpacket_req req = {
221		.tp_block_size = getpagesize(),
222		.tp_frame_size = getpagesize(),
223		.tp_block_nr   = RING_NUM_FRAMES,
224		.tp_frame_nr   = RING_NUM_FRAMES,
225	};
226	char *ring;
227	int val = TPACKET_V2;
228
229	if (setsockopt(fd, SOL_PACKET, PACKET_VERSION, (void *) &val,
230		       sizeof(val))) {
231		perror("packetsock ring setsockopt version");
232		exit(1);
233	}
234	if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING, (void *) &req,
235		       sizeof(req))) {
236		perror("packetsock ring setsockopt");
237		exit(1);
238	}
239
240	ring = mmap(0, req.tp_block_size * req.tp_block_nr,
241		    PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
242	if (ring == MAP_FAILED) {
243		perror("packetsock ring mmap");
244		exit(1);
245	}
246
247	return ring;
248}
249
250static int sock_fanout_read_ring(int fd, void *ring)
251{
252	struct tpacket2_hdr *header = ring;
253	int count = 0;
254
255	while (count < RING_NUM_FRAMES && header->tp_status & TP_STATUS_USER) {
256		count++;
257		header = ring + (count * getpagesize());
258	}
259
260	return count;
261}
262
263static int sock_fanout_read(int fds[], char *rings[], const int expect[])
264{
265	int ret[2];
266
267	ret[0] = sock_fanout_read_ring(fds[0], rings[0]);
268	ret[1] = sock_fanout_read_ring(fds[1], rings[1]);
269
270	fprintf(stderr, "info: count=%d,%d, expect=%d,%d\n",
271			ret[0], ret[1], expect[0], expect[1]);
272
273	if ((!(ret[0] == expect[0] && ret[1] == expect[1])) &&
274	    (!(ret[0] == expect[1] && ret[1] == expect[0]))) {
275		fprintf(stderr, "warning: incorrect queue lengths\n");
276		return 1;
277	}
278
279	return 0;
280}
281
282/* Test that creating/joining a fanout group fails for unbound socket without
283 * a specified protocol
284 */
285static void test_unbound_fanout(void)
286{
287	int val, fd0, fd1, err;
288
289	fprintf(stderr, "test: unbound fanout\n");
290	fd0 = socket(PF_PACKET, SOCK_RAW, 0);
291	if (fd0 < 0) {
292		perror("socket packet");
293		exit(1);
294	}
295	/* Try to create a new fanout group. Should fail. */
296	val = (PACKET_FANOUT_HASH << 16) | 1;
297	err = setsockopt(fd0, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val));
298	if (!err) {
299		fprintf(stderr, "ERROR: unbound socket fanout create\n");
300		exit(1);
301	}
302	fd1 = sock_fanout_open(PACKET_FANOUT_HASH, 1);
303	if (fd1 == -1) {
304		fprintf(stderr, "ERROR: failed to open HASH socket\n");
305		exit(1);
306	}
307	/* Try to join an existing fanout group. Should fail. */
308	err = setsockopt(fd0, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val));
309	if (!err) {
310		fprintf(stderr, "ERROR: unbound socket fanout join\n");
311		exit(1);
312	}
313	close(fd0);
314	close(fd1);
315}
316
317/* Test illegal mode + flag combination */
318static void test_control_single(void)
319{
320	fprintf(stderr, "test: control single socket\n");
321
322	if (sock_fanout_open(PACKET_FANOUT_ROLLOVER |
323			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
324		fprintf(stderr, "ERROR: opened socket with dual rollover\n");
325		exit(1);
326	}
327}
328
329/* Test illegal group with different modes or flags */
330static void test_control_group(int toggle)
331{
332	int fds[2];
333
334	if (toggle)
335		fprintf(stderr, "test: control multiple sockets with link down toggle\n");
336	else
337		fprintf(stderr, "test: control multiple sockets\n");
338
339	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
340	if (fds[0] == -1) {
341		fprintf(stderr, "ERROR: failed to open HASH socket\n");
342		exit(1);
343	}
344	if (toggle)
345		loopback_set_up_down(0);
346	if (sock_fanout_open(PACKET_FANOUT_HASH |
347			       PACKET_FANOUT_FLAG_DEFRAG, 0) != -1) {
348		fprintf(stderr, "ERROR: joined group with wrong flag defrag\n");
349		exit(1);
350	}
351	if (sock_fanout_open(PACKET_FANOUT_HASH |
352			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
353		fprintf(stderr, "ERROR: joined group with wrong flag ro\n");
354		exit(1);
355	}
356	if (sock_fanout_open(PACKET_FANOUT_CPU, 0) != -1) {
357		fprintf(stderr, "ERROR: joined group with wrong mode\n");
358		exit(1);
359	}
360	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
361	if (fds[1] == -1) {
362		fprintf(stderr, "ERROR: failed to join group\n");
363		exit(1);
364	}
365	if (toggle)
366		loopback_set_up_down(1);
367	if (close(fds[1]) || close(fds[0])) {
368		fprintf(stderr, "ERROR: closing sockets\n");
369		exit(1);
370	}
371}
372
373/* Test illegal max_num_members values */
374static void test_control_group_max_num_members(void)
375{
376	int fds[3];
377
378	fprintf(stderr, "test: control multiple sockets, max_num_members\n");
379
380	/* expected failure on greater than PACKET_FANOUT_MAX */
381	cfg_max_num_members = (1 << 16) + 1;
382	if (sock_fanout_open(PACKET_FANOUT_HASH, 0) != -1) {
383		fprintf(stderr, "ERROR: max_num_members > PACKET_FANOUT_MAX\n");
384		exit(1);
385	}
386
387	cfg_max_num_members = 256;
388	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
389	if (fds[0] == -1) {
390		fprintf(stderr, "ERROR: failed open\n");
391		exit(1);
392	}
393
394	/* expected failure on joining group with different max_num_members */
395	cfg_max_num_members = 257;
396	if (sock_fanout_open(PACKET_FANOUT_HASH, 0) != -1) {
397		fprintf(stderr, "ERROR: set different max_num_members\n");
398		exit(1);
399	}
400
401	/* success on joining group with same max_num_members */
402	cfg_max_num_members = 256;
403	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
404	if (fds[1] == -1) {
405		fprintf(stderr, "ERROR: failed to join group\n");
406		exit(1);
407	}
408
409	/* success on joining group with max_num_members unspecified */
410	cfg_max_num_members = 0;
411	fds[2] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
412	if (fds[2] == -1) {
413		fprintf(stderr, "ERROR: failed to join group\n");
414		exit(1);
415	}
416
417	if (close(fds[2]) || close(fds[1]) || close(fds[0])) {
418		fprintf(stderr, "ERROR: closing sockets\n");
419		exit(1);
420	}
421}
422
423/* Test creating a unique fanout group ids */
424static void test_unique_fanout_group_ids(void)
425{
426	int fds[3];
427	uint16_t typeflags, first_group_id, second_group_id;
428
429	fprintf(stderr, "test: unique ids\n");
430
431	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH |
432				  PACKET_FANOUT_FLAG_UNIQUEID, 0);
433	if (fds[0] == -1) {
434		fprintf(stderr, "ERROR: failed to create a unique id group.\n");
435		exit(1);
436	}
437
438	sock_fanout_getopts(fds[0], &typeflags, &first_group_id);
439	if (typeflags != PACKET_FANOUT_HASH) {
440		fprintf(stderr, "ERROR: unexpected typeflags %x\n", typeflags);
441		exit(1);
442	}
443
444	if (sock_fanout_open(PACKET_FANOUT_CPU, first_group_id) != -1) {
445		fprintf(stderr, "ERROR: joined group with wrong type.\n");
446		exit(1);
447	}
448
449	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, first_group_id);
450	if (fds[1] == -1) {
451		fprintf(stderr,
452			"ERROR: failed to join previously created group.\n");
453		exit(1);
454	}
455
456	fds[2] = sock_fanout_open(PACKET_FANOUT_HASH |
457				  PACKET_FANOUT_FLAG_UNIQUEID, 0);
458	if (fds[2] == -1) {
459		fprintf(stderr,
460			"ERROR: failed to create a second unique id group.\n");
461		exit(1);
462	}
463
464	sock_fanout_getopts(fds[2], &typeflags, &second_group_id);
465	if (sock_fanout_open(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_UNIQUEID,
466			     second_group_id) != -1) {
467		fprintf(stderr,
468			"ERROR: specified a group id when requesting unique id\n");
469		exit(1);
470	}
471
472	if (close(fds[0]) || close(fds[1]) || close(fds[2])) {
473		fprintf(stderr, "ERROR: closing sockets\n");
474		exit(1);
475	}
476}
477
478static int test_datapath(uint16_t typeflags, int port_off,
479			 const int expect1[], const int expect2[])
480{
481	const int expect0[] = { 0, 0 };
482	char *rings[2];
483	uint8_t type = typeflags & 0xFF;
484	int fds[2], fds_udp[2][2], ret;
485
486	fprintf(stderr, "\ntest: datapath 0x%hx ports %hu,%hu\n",
487		typeflags, (uint16_t)PORT_BASE,
488		(uint16_t)(PORT_BASE + port_off));
489
490	fds[0] = sock_fanout_open(typeflags, 0);
491	fds[1] = sock_fanout_open(typeflags, 0);
492	if (fds[0] == -1 || fds[1] == -1) {
493		fprintf(stderr, "ERROR: failed open\n");
494		exit(1);
495	}
496	if (type == PACKET_FANOUT_CBPF)
497		sock_fanout_set_cbpf(fds[0]);
498	else if (type == PACKET_FANOUT_EBPF)
499		sock_fanout_set_ebpf(fds[0]);
500
501	rings[0] = sock_fanout_open_ring(fds[0]);
502	rings[1] = sock_fanout_open_ring(fds[1]);
503	pair_udp_open(fds_udp[0], PORT_BASE);
504	pair_udp_open(fds_udp[1], PORT_BASE + port_off);
505	sock_fanout_read(fds, rings, expect0);
506
507	/* Send data, but not enough to overflow a queue */
508	pair_udp_send(fds_udp[0], 15);
509	pair_udp_send_char(fds_udp[1], 5, DATA_CHAR_1);
510	ret = sock_fanout_read(fds, rings, expect1);
511
512	/* Send more data, overflow the queue */
513	pair_udp_send_char(fds_udp[0], 15, DATA_CHAR_1);
514	/* TODO: ensure consistent order between expect1 and expect2 */
515	ret |= sock_fanout_read(fds, rings, expect2);
516
517	if (munmap(rings[1], RING_NUM_FRAMES * getpagesize()) ||
518	    munmap(rings[0], RING_NUM_FRAMES * getpagesize())) {
519		fprintf(stderr, "close rings\n");
520		exit(1);
521	}
522	if (close(fds_udp[1][1]) || close(fds_udp[1][0]) ||
523	    close(fds_udp[0][1]) || close(fds_udp[0][0]) ||
524	    close(fds[1]) || close(fds[0])) {
525		fprintf(stderr, "close datapath\n");
526		exit(1);
527	}
528
529	return ret;
530}
531
532static int set_cpuaffinity(int cpuid)
533{
534	cpu_set_t mask;
535
536	CPU_ZERO(&mask);
537	CPU_SET(cpuid, &mask);
538	if (sched_setaffinity(0, sizeof(mask), &mask)) {
539		if (errno != EINVAL) {
540			fprintf(stderr, "setaffinity %d\n", cpuid);
541			exit(1);
542		}
543		return 1;
544	}
545
546	return 0;
547}
548
549int main(int argc, char **argv)
550{
551	const int expect_hash[2][2]	= { { 15, 5 },  { 20, 5 } };
552	const int expect_hash_rb[2][2]	= { { 15, 5 },  { 20, 15 } };
553	const int expect_lb[2][2]	= { { 10, 10 }, { 18, 17 } };
554	const int expect_rb[2][2]	= { { 15, 5 },  { 20, 15 } };
555	const int expect_cpu0[2][2]	= { { 20, 0 },  { 20, 0 } };
556	const int expect_cpu1[2][2]	= { { 0, 20 },  { 0, 20 } };
557	const int expect_bpf[2][2]	= { { 15, 5 },  { 15, 20 } };
558	const int expect_uniqueid[2][2] = { { 20, 20},  { 20, 20 } };
559	int port_off = 2, tries = 20, ret;
560
561	test_unbound_fanout();
562	test_control_single();
563	test_control_group(0);
564	test_control_group(1);
565	test_control_group_max_num_members();
566	test_unique_fanout_group_ids();
567
568	/* PACKET_FANOUT_MAX */
569	cfg_max_num_members = 1 << 16;
570	/* find a set of ports that do not collide onto the same socket */
571	ret = test_datapath(PACKET_FANOUT_HASH, port_off,
572			    expect_hash[0], expect_hash[1]);
573	while (ret) {
574		fprintf(stderr, "info: trying alternate ports (%d)\n", tries);
575		ret = test_datapath(PACKET_FANOUT_HASH, ++port_off,
576				    expect_hash[0], expect_hash[1]);
577		if (!--tries) {
578			fprintf(stderr, "too many collisions\n");
579			return 1;
580		}
581	}
582
583	ret |= test_datapath(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_ROLLOVER,
584			     port_off, expect_hash_rb[0], expect_hash_rb[1]);
585	ret |= test_datapath(PACKET_FANOUT_LB,
586			     port_off, expect_lb[0], expect_lb[1]);
587	ret |= test_datapath(PACKET_FANOUT_ROLLOVER,
588			     port_off, expect_rb[0], expect_rb[1]);
589
590	ret |= test_datapath(PACKET_FANOUT_CBPF,
591			     port_off, expect_bpf[0], expect_bpf[1]);
592	ret |= test_datapath(PACKET_FANOUT_EBPF,
593			     port_off, expect_bpf[0], expect_bpf[1]);
594
595	set_cpuaffinity(0);
596	ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
597			     expect_cpu0[0], expect_cpu0[1]);
598	if (!set_cpuaffinity(1))
599		/* TODO: test that choice alternates with previous */
600		ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
601				     expect_cpu1[0], expect_cpu1[1]);
602
603	ret |= test_datapath(PACKET_FANOUT_FLAG_UNIQUEID, port_off,
604			     expect_uniqueid[0], expect_uniqueid[1]);
605
606	if (ret)
607		return 1;
608
609	printf("OK. All tests passed\n");
610	return 0;
611}