xref: /linux/tools/testing/selftests/net/psock_fanout.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  * Copyright 2013 Google Inc.
3  * Author: Willem de Bruijn (willemb@google.com)
4  *
5  * A basic test of packet socket fanout behavior.
6  *
7  * Control:
8  * - create fanout fails as expected with illegal flag combinations
9  * - join   fanout fails as expected with diverging types or flags
10  *
11  * Datapath:
12  *   Open a pair of packet sockets and a pair of INET sockets, send a known
13  *   number of packets across the two INET sockets and count the number of
14  *   packets enqueued onto the two packet sockets.
15  *
16  *   The test currently runs for
17  *   - PACKET_FANOUT_HASH
18  *   - PACKET_FANOUT_HASH with PACKET_FANOUT_FLAG_ROLLOVER
19  *   - PACKET_FANOUT_LB
20  *   - PACKET_FANOUT_CPU
21  *   - PACKET_FANOUT_ROLLOVER
22  *   - PACKET_FANOUT_CBPF
23  *   - PACKET_FANOUT_EBPF
24  *
25  * Todo:
26  * - functionality: PACKET_FANOUT_FLAG_DEFRAG
27  *
28  * License (GPLv2):
29  *
30  * This program is free software; you can redistribute it and/or modify it
31  * under the terms and conditions of the GNU General Public License,
32  * version 2, as published by the Free Software Foundation.
33  *
34  * This program is distributed in the hope it will be useful, but WITHOUT
35  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
36  * FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for
37  * more details.
38  *
39  * You should have received a copy of the GNU General Public License along with
40  * this program; if not, write to the Free Software Foundation, Inc.,
41  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
42  */
43 
44 #define _GNU_SOURCE		/* for sched_setaffinity */
45 
46 #include <arpa/inet.h>
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <linux/unistd.h>	/* for __NR_bpf */
50 #include <linux/filter.h>
51 #include <linux/bpf.h>
52 #include <linux/if_packet.h>
53 #include <net/ethernet.h>
54 #include <netinet/ip.h>
55 #include <netinet/udp.h>
56 #include <poll.h>
57 #include <sched.h>
58 #include <stdint.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <sys/mman.h>
63 #include <sys/socket.h>
64 #include <sys/stat.h>
65 #include <sys/types.h>
66 #include <unistd.h>
67 
68 #include "psock_lib.h"
69 
70 #define RING_NUM_FRAMES			20
71 
72 /* Open a socket in a given fanout mode.
73  * @return -1 if mode is bad, a valid socket otherwise */
74 static int sock_fanout_open(uint16_t typeflags, int num_packets)
75 {
76 	int fd, val;
77 
78 	fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
79 	if (fd < 0) {
80 		perror("socket packet");
81 		exit(1);
82 	}
83 
84 	/* fanout group ID is always 0: tests whether old groups are deleted */
85 	val = ((int) typeflags) << 16;
86 	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val))) {
87 		if (close(fd)) {
88 			perror("close packet");
89 			exit(1);
90 		}
91 		return -1;
92 	}
93 
94 	pair_udp_setfilter(fd);
95 	return fd;
96 }
97 
98 static void sock_fanout_set_ebpf(int fd)
99 {
100 	const int len_off = __builtin_offsetof(struct __sk_buff, len);
101 	struct bpf_insn prog[] = {
102 		{ BPF_ALU64 | BPF_MOV | BPF_X,   6, 1, 0, 0 },
103 		{ BPF_LDX   | BPF_W   | BPF_MEM, 0, 6, len_off, 0 },
104 		{ BPF_JMP   | BPF_JGE | BPF_K,   0, 0, 1, DATA_LEN },
105 		{ BPF_JMP   | BPF_JA  | BPF_K,   0, 0, 4, 0 },
106 		{ BPF_LD    | BPF_B   | BPF_ABS, 0, 0, 0, 0x50 },
107 		{ BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 2, DATA_CHAR },
108 		{ BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 1, DATA_CHAR_1 },
109 		{ BPF_ALU   | BPF_MOV | BPF_K,   0, 0, 0, 0 },
110 		{ BPF_JMP   | BPF_EXIT,          0, 0, 0, 0 }
111 	};
112 	char log_buf[512];
113 	union bpf_attr attr;
114 	int pfd;
115 
116 	memset(&attr, 0, sizeof(attr));
117 	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
118 	attr.insns = (unsigned long) prog;
119 	attr.insn_cnt = sizeof(prog) / sizeof(prog[0]);
120 	attr.license = (unsigned long) "GPL";
121 	attr.log_buf = (unsigned long) log_buf,
122 	attr.log_size = sizeof(log_buf),
123 	attr.log_level = 1,
124 
125 	pfd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
126 	if (pfd < 0) {
127 		perror("bpf");
128 		fprintf(stderr, "bpf verifier:\n%s\n", log_buf);
129 		exit(1);
130 	}
131 
132 	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &pfd, sizeof(pfd))) {
133 		perror("fanout data ebpf");
134 		exit(1);
135 	}
136 
137 	if (close(pfd)) {
138 		perror("close ebpf");
139 		exit(1);
140 	}
141 }
142 
143 static char *sock_fanout_open_ring(int fd)
144 {
145 	struct tpacket_req req = {
146 		.tp_block_size = getpagesize(),
147 		.tp_frame_size = getpagesize(),
148 		.tp_block_nr   = RING_NUM_FRAMES,
149 		.tp_frame_nr   = RING_NUM_FRAMES,
150 	};
151 	char *ring;
152 	int val = TPACKET_V2;
153 
154 	if (setsockopt(fd, SOL_PACKET, PACKET_VERSION, (void *) &val,
155 		       sizeof(val))) {
156 		perror("packetsock ring setsockopt version");
157 		exit(1);
158 	}
159 	if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING, (void *) &req,
160 		       sizeof(req))) {
161 		perror("packetsock ring setsockopt");
162 		exit(1);
163 	}
164 
165 	ring = mmap(0, req.tp_block_size * req.tp_block_nr,
166 		    PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
167 	if (ring == MAP_FAILED) {
168 		perror("packetsock ring mmap");
169 		exit(1);
170 	}
171 
172 	return ring;
173 }
174 
175 static int sock_fanout_read_ring(int fd, void *ring)
176 {
177 	struct tpacket2_hdr *header = ring;
178 	int count = 0;
179 
180 	while (count < RING_NUM_FRAMES && header->tp_status & TP_STATUS_USER) {
181 		count++;
182 		header = ring + (count * getpagesize());
183 	}
184 
185 	return count;
186 }
187 
188 static int sock_fanout_read(int fds[], char *rings[], const int expect[])
189 {
190 	int ret[2];
191 
192 	ret[0] = sock_fanout_read_ring(fds[0], rings[0]);
193 	ret[1] = sock_fanout_read_ring(fds[1], rings[1]);
194 
195 	fprintf(stderr, "info: count=%d,%d, expect=%d,%d\n",
196 			ret[0], ret[1], expect[0], expect[1]);
197 
198 	if ((!(ret[0] == expect[0] && ret[1] == expect[1])) &&
199 	    (!(ret[0] == expect[1] && ret[1] == expect[0]))) {
200 		fprintf(stderr, "ERROR: incorrect queue lengths\n");
201 		return 1;
202 	}
203 
204 	return 0;
205 }
206 
207 /* Test illegal mode + flag combination */
208 static void test_control_single(void)
209 {
210 	fprintf(stderr, "test: control single socket\n");
211 
212 	if (sock_fanout_open(PACKET_FANOUT_ROLLOVER |
213 			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
214 		fprintf(stderr, "ERROR: opened socket with dual rollover\n");
215 		exit(1);
216 	}
217 }
218 
219 /* Test illegal group with different modes or flags */
220 static void test_control_group(void)
221 {
222 	int fds[2];
223 
224 	fprintf(stderr, "test: control multiple sockets\n");
225 
226 	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 20);
227 	if (fds[0] == -1) {
228 		fprintf(stderr, "ERROR: failed to open HASH socket\n");
229 		exit(1);
230 	}
231 	if (sock_fanout_open(PACKET_FANOUT_HASH |
232 			       PACKET_FANOUT_FLAG_DEFRAG, 10) != -1) {
233 		fprintf(stderr, "ERROR: joined group with wrong flag defrag\n");
234 		exit(1);
235 	}
236 	if (sock_fanout_open(PACKET_FANOUT_HASH |
237 			       PACKET_FANOUT_FLAG_ROLLOVER, 10) != -1) {
238 		fprintf(stderr, "ERROR: joined group with wrong flag ro\n");
239 		exit(1);
240 	}
241 	if (sock_fanout_open(PACKET_FANOUT_CPU, 10) != -1) {
242 		fprintf(stderr, "ERROR: joined group with wrong mode\n");
243 		exit(1);
244 	}
245 	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 20);
246 	if (fds[1] == -1) {
247 		fprintf(stderr, "ERROR: failed to join group\n");
248 		exit(1);
249 	}
250 	if (close(fds[1]) || close(fds[0])) {
251 		fprintf(stderr, "ERROR: closing sockets\n");
252 		exit(1);
253 	}
254 }
255 
256 static int test_datapath(uint16_t typeflags, int port_off,
257 			 const int expect1[], const int expect2[])
258 {
259 	const int expect0[] = { 0, 0 };
260 	char *rings[2];
261 	uint8_t type = typeflags & 0xFF;
262 	int fds[2], fds_udp[2][2], ret;
263 
264 	fprintf(stderr, "test: datapath 0x%hx\n", typeflags);
265 
266 	fds[0] = sock_fanout_open(typeflags, 20);
267 	fds[1] = sock_fanout_open(typeflags, 20);
268 	if (fds[0] == -1 || fds[1] == -1) {
269 		fprintf(stderr, "ERROR: failed open\n");
270 		exit(1);
271 	}
272 	if (type == PACKET_FANOUT_CBPF)
273 		sock_setfilter(fds[0], SOL_PACKET, PACKET_FANOUT_DATA);
274 	else if (type == PACKET_FANOUT_EBPF)
275 		sock_fanout_set_ebpf(fds[0]);
276 
277 	rings[0] = sock_fanout_open_ring(fds[0]);
278 	rings[1] = sock_fanout_open_ring(fds[1]);
279 	pair_udp_open(fds_udp[0], PORT_BASE);
280 	pair_udp_open(fds_udp[1], PORT_BASE + port_off);
281 	sock_fanout_read(fds, rings, expect0);
282 
283 	/* Send data, but not enough to overflow a queue */
284 	pair_udp_send(fds_udp[0], 15);
285 	pair_udp_send_char(fds_udp[1], 5, DATA_CHAR_1);
286 	ret = sock_fanout_read(fds, rings, expect1);
287 
288 	/* Send more data, overflow the queue */
289 	pair_udp_send_char(fds_udp[0], 15, DATA_CHAR_1);
290 	/* TODO: ensure consistent order between expect1 and expect2 */
291 	ret |= sock_fanout_read(fds, rings, expect2);
292 
293 	if (munmap(rings[1], RING_NUM_FRAMES * getpagesize()) ||
294 	    munmap(rings[0], RING_NUM_FRAMES * getpagesize())) {
295 		fprintf(stderr, "close rings\n");
296 		exit(1);
297 	}
298 	if (close(fds_udp[1][1]) || close(fds_udp[1][0]) ||
299 	    close(fds_udp[0][1]) || close(fds_udp[0][0]) ||
300 	    close(fds[1]) || close(fds[0])) {
301 		fprintf(stderr, "close datapath\n");
302 		exit(1);
303 	}
304 
305 	return ret;
306 }
307 
308 static int set_cpuaffinity(int cpuid)
309 {
310 	cpu_set_t mask;
311 
312 	CPU_ZERO(&mask);
313 	CPU_SET(cpuid, &mask);
314 	if (sched_setaffinity(0, sizeof(mask), &mask)) {
315 		if (errno != EINVAL) {
316 			fprintf(stderr, "setaffinity %d\n", cpuid);
317 			exit(1);
318 		}
319 		return 1;
320 	}
321 
322 	return 0;
323 }
324 
325 int main(int argc, char **argv)
326 {
327 	const int expect_hash[2][2]	= { { 15, 5 },  { 20, 5 } };
328 	const int expect_hash_rb[2][2]	= { { 15, 5 },  { 20, 15 } };
329 	const int expect_lb[2][2]	= { { 10, 10 }, { 18, 17 } };
330 	const int expect_rb[2][2]	= { { 15, 5 },  { 20, 15 } };
331 	const int expect_cpu0[2][2]	= { { 20, 0 },  { 20, 0 } };
332 	const int expect_cpu1[2][2]	= { { 0, 20 },  { 0, 20 } };
333 	const int expect_bpf[2][2]	= { { 15, 5 },  { 15, 20 } };
334 	int port_off = 2, tries = 5, ret;
335 
336 	test_control_single();
337 	test_control_group();
338 
339 	/* find a set of ports that do not collide onto the same socket */
340 	ret = test_datapath(PACKET_FANOUT_HASH, port_off,
341 			    expect_hash[0], expect_hash[1]);
342 	while (ret && tries--) {
343 		fprintf(stderr, "info: trying alternate ports (%d)\n", tries);
344 		ret = test_datapath(PACKET_FANOUT_HASH, ++port_off,
345 				    expect_hash[0], expect_hash[1]);
346 	}
347 
348 	ret |= test_datapath(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_ROLLOVER,
349 			     port_off, expect_hash_rb[0], expect_hash_rb[1]);
350 	ret |= test_datapath(PACKET_FANOUT_LB,
351 			     port_off, expect_lb[0], expect_lb[1]);
352 	ret |= test_datapath(PACKET_FANOUT_ROLLOVER,
353 			     port_off, expect_rb[0], expect_rb[1]);
354 
355 	ret |= test_datapath(PACKET_FANOUT_CBPF,
356 			     port_off, expect_bpf[0], expect_bpf[1]);
357 	ret |= test_datapath(PACKET_FANOUT_EBPF,
358 			     port_off, expect_bpf[0], expect_bpf[1]);
359 
360 	set_cpuaffinity(0);
361 	ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
362 			     expect_cpu0[0], expect_cpu0[1]);
363 	if (!set_cpuaffinity(1))
364 		/* TODO: test that choice alternates with previous */
365 		ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
366 				     expect_cpu1[0], expect_cpu1[1]);
367 
368 	if (ret)
369 		return 1;
370 
371 	printf("OK. All tests passed\n");
372 	return 0;
373 }
374