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      1 /*
      2  * Copyright 2013 Google Inc.
      3  * Author: Willem de Bruijn (willemb (at) 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, uint16_t group_id)
     75 {
     76 	int fd, val;
     77 
     78 	fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_IP));
     79 	if (fd < 0) {
     80 		perror("socket packet");
     81 		exit(1);
     82 	}
     83 
     84 	val = (((int) typeflags) << 16) | group_id;
     85 	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val))) {
     86 		if (close(fd)) {
     87 			perror("close packet");
     88 			exit(1);
     89 		}
     90 		return -1;
     91 	}
     92 
     93 	pair_udp_setfilter(fd);
     94 	return fd;
     95 }
     96 
     97 static void sock_fanout_set_cbpf(int fd)
     98 {
     99 	struct sock_filter bpf_filter[] = {
    100 		BPF_STMT(BPF_LD+BPF_B+BPF_ABS, 80),	      /* ldb [80] */
    101 		BPF_STMT(BPF_RET+BPF_A, 0),		      /* ret A */
    102 	};
    103 	struct sock_fprog bpf_prog;
    104 
    105 	bpf_prog.filter = bpf_filter;
    106 	bpf_prog.len = sizeof(bpf_filter) / sizeof(struct sock_filter);
    107 
    108 	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &bpf_prog,
    109 		       sizeof(bpf_prog))) {
    110 		perror("fanout data cbpf");
    111 		exit(1);
    112 	}
    113 }
    114 
    115 static void sock_fanout_getopts(int fd, uint16_t *typeflags, uint16_t *group_id)
    116 {
    117 	int sockopt;
    118 	socklen_t sockopt_len = sizeof(sockopt);
    119 
    120 	if (getsockopt(fd, SOL_PACKET, PACKET_FANOUT,
    121 		       &sockopt, &sockopt_len)) {
    122 		perror("failed to getsockopt");
    123 		exit(1);
    124 	}
    125 	*typeflags = sockopt >> 16;
    126 	*group_id = sockopt & 0xfffff;
    127 }
    128 
    129 static void sock_fanout_set_ebpf(int fd)
    130 {
    131 	const int len_off = __builtin_offsetof(struct __sk_buff, len);
    132 	struct bpf_insn prog[] = {
    133 		{ BPF_ALU64 | BPF_MOV | BPF_X,   6, 1, 0, 0 },
    134 		{ BPF_LDX   | BPF_W   | BPF_MEM, 0, 6, len_off, 0 },
    135 		{ BPF_JMP   | BPF_JGE | BPF_K,   0, 0, 1, DATA_LEN },
    136 		{ BPF_JMP   | BPF_JA  | BPF_K,   0, 0, 4, 0 },
    137 		{ BPF_LD    | BPF_B   | BPF_ABS, 0, 0, 0, 0x50 },
    138 		{ BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 2, DATA_CHAR },
    139 		{ BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 1, DATA_CHAR_1 },
    140 		{ BPF_ALU   | BPF_MOV | BPF_K,   0, 0, 0, 0 },
    141 		{ BPF_JMP   | BPF_EXIT,          0, 0, 0, 0 }
    142 	};
    143 	char log_buf[512];
    144 	union bpf_attr attr;
    145 	int pfd;
    146 
    147 	memset(&attr, 0, sizeof(attr));
    148 	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
    149 	attr.insns = (unsigned long) prog;
    150 	attr.insn_cnt = sizeof(prog) / sizeof(prog[0]);
    151 	attr.license = (unsigned long) "GPL";
    152 	attr.log_buf = (unsigned long) log_buf,
    153 	attr.log_size = sizeof(log_buf),
    154 	attr.log_level = 1,
    155 
    156 	pfd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
    157 	if (pfd < 0) {
    158 		perror("bpf");
    159 		fprintf(stderr, "bpf verifier:\n%s\n", log_buf);
    160 		exit(1);
    161 	}
    162 
    163 	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &pfd, sizeof(pfd))) {
    164 		perror("fanout data ebpf");
    165 		exit(1);
    166 	}
    167 
    168 	if (close(pfd)) {
    169 		perror("close ebpf");
    170 		exit(1);
    171 	}
    172 }
    173 
    174 static char *sock_fanout_open_ring(int fd)
    175 {
    176 	struct tpacket_req req = {
    177 		.tp_block_size = getpagesize(),
    178 		.tp_frame_size = getpagesize(),
    179 		.tp_block_nr   = RING_NUM_FRAMES,
    180 		.tp_frame_nr   = RING_NUM_FRAMES,
    181 	};
    182 	char *ring;
    183 	int val = TPACKET_V2;
    184 
    185 	if (setsockopt(fd, SOL_PACKET, PACKET_VERSION, (void *) &val,
    186 		       sizeof(val))) {
    187 		perror("packetsock ring setsockopt version");
    188 		exit(1);
    189 	}
    190 	if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING, (void *) &req,
    191 		       sizeof(req))) {
    192 		perror("packetsock ring setsockopt");
    193 		exit(1);
    194 	}
    195 
    196 	ring = mmap(0, req.tp_block_size * req.tp_block_nr,
    197 		    PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    198 	if (ring == MAP_FAILED) {
    199 		perror("packetsock ring mmap");
    200 		exit(1);
    201 	}
    202 
    203 	return ring;
    204 }
    205 
    206 static int sock_fanout_read_ring(int fd, void *ring)
    207 {
    208 	struct tpacket2_hdr *header = ring;
    209 	int count = 0;
    210 
    211 	while (count < RING_NUM_FRAMES && header->tp_status & TP_STATUS_USER) {
    212 		count++;
    213 		header = ring + (count * getpagesize());
    214 	}
    215 
    216 	return count;
    217 }
    218 
    219 static int sock_fanout_read(int fds[], char *rings[], const int expect[])
    220 {
    221 	int ret[2];
    222 
    223 	ret[0] = sock_fanout_read_ring(fds[0], rings[0]);
    224 	ret[1] = sock_fanout_read_ring(fds[1], rings[1]);
    225 
    226 	fprintf(stderr, "info: count=%d,%d, expect=%d,%d\n",
    227 			ret[0], ret[1], expect[0], expect[1]);
    228 
    229 	if ((!(ret[0] == expect[0] && ret[1] == expect[1])) &&
    230 	    (!(ret[0] == expect[1] && ret[1] == expect[0]))) {
    231 		fprintf(stderr, "ERROR: incorrect queue lengths\n");
    232 		return 1;
    233 	}
    234 
    235 	return 0;
    236 }
    237 
    238 /* Test illegal mode + flag combination */
    239 static void test_control_single(void)
    240 {
    241 	fprintf(stderr, "test: control single socket\n");
    242 
    243 	if (sock_fanout_open(PACKET_FANOUT_ROLLOVER |
    244 			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
    245 		fprintf(stderr, "ERROR: opened socket with dual rollover\n");
    246 		exit(1);
    247 	}
    248 }
    249 
    250 /* Test illegal group with different modes or flags */
    251 static void test_control_group(void)
    252 {
    253 	int fds[2];
    254 
    255 	fprintf(stderr, "test: control multiple sockets\n");
    256 
    257 	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
    258 	if (fds[0] == -1) {
    259 		fprintf(stderr, "ERROR: failed to open HASH socket\n");
    260 		exit(1);
    261 	}
    262 	if (sock_fanout_open(PACKET_FANOUT_HASH |
    263 			       PACKET_FANOUT_FLAG_DEFRAG, 0) != -1) {
    264 		fprintf(stderr, "ERROR: joined group with wrong flag defrag\n");
    265 		exit(1);
    266 	}
    267 	if (sock_fanout_open(PACKET_FANOUT_HASH |
    268 			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
    269 		fprintf(stderr, "ERROR: joined group with wrong flag ro\n");
    270 		exit(1);
    271 	}
    272 	if (sock_fanout_open(PACKET_FANOUT_CPU, 0) != -1) {
    273 		fprintf(stderr, "ERROR: joined group with wrong mode\n");
    274 		exit(1);
    275 	}
    276 	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
    277 	if (fds[1] == -1) {
    278 		fprintf(stderr, "ERROR: failed to join group\n");
    279 		exit(1);
    280 	}
    281 	if (close(fds[1]) || close(fds[0])) {
    282 		fprintf(stderr, "ERROR: closing sockets\n");
    283 		exit(1);
    284 	}
    285 }
    286 
    287 /* Test creating a unique fanout group ids */
    288 static void test_unique_fanout_group_ids(void)
    289 {
    290 	int fds[3];
    291 	uint16_t typeflags, first_group_id, second_group_id;
    292 
    293 	fprintf(stderr, "test: unique ids\n");
    294 
    295 	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH |
    296 				  PACKET_FANOUT_FLAG_UNIQUEID, 0);
    297 	if (fds[0] == -1) {
    298 		fprintf(stderr, "ERROR: failed to create a unique id group.\n");
    299 		exit(1);
    300 	}
    301 
    302 	sock_fanout_getopts(fds[0], &typeflags, &first_group_id);
    303 	if (typeflags != PACKET_FANOUT_HASH) {
    304 		fprintf(stderr, "ERROR: unexpected typeflags %x\n", typeflags);
    305 		exit(1);
    306 	}
    307 
    308 	if (sock_fanout_open(PACKET_FANOUT_CPU, first_group_id) != -1) {
    309 		fprintf(stderr, "ERROR: joined group with wrong type.\n");
    310 		exit(1);
    311 	}
    312 
    313 	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, first_group_id);
    314 	if (fds[1] == -1) {
    315 		fprintf(stderr,
    316 			"ERROR: failed to join previously created group.\n");
    317 		exit(1);
    318 	}
    319 
    320 	fds[2] = sock_fanout_open(PACKET_FANOUT_HASH |
    321 				  PACKET_FANOUT_FLAG_UNIQUEID, 0);
    322 	if (fds[2] == -1) {
    323 		fprintf(stderr,
    324 			"ERROR: failed to create a second unique id group.\n");
    325 		exit(1);
    326 	}
    327 
    328 	sock_fanout_getopts(fds[2], &typeflags, &second_group_id);
    329 	if (sock_fanout_open(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_UNIQUEID,
    330 			     second_group_id) != -1) {
    331 		fprintf(stderr,
    332 			"ERROR: specified a group id when requesting unique id\n");
    333 		exit(1);
    334 	}
    335 
    336 	if (close(fds[0]) || close(fds[1]) || close(fds[2])) {
    337 		fprintf(stderr, "ERROR: closing sockets\n");
    338 		exit(1);
    339 	}
    340 }
    341 
    342 static int test_datapath(uint16_t typeflags, int port_off,
    343 			 const int expect1[], const int expect2[])
    344 {
    345 	const int expect0[] = { 0, 0 };
    346 	char *rings[2];
    347 	uint8_t type = typeflags & 0xFF;
    348 	int fds[2], fds_udp[2][2], ret;
    349 
    350 	fprintf(stderr, "test: datapath 0x%hx\n", typeflags);
    351 
    352 	fds[0] = sock_fanout_open(typeflags, 0);
    353 	fds[1] = sock_fanout_open(typeflags, 0);
    354 	if (fds[0] == -1 || fds[1] == -1) {
    355 		fprintf(stderr, "ERROR: failed open\n");
    356 		exit(1);
    357 	}
    358 	if (type == PACKET_FANOUT_CBPF)
    359 		sock_fanout_set_cbpf(fds[0]);
    360 	else if (type == PACKET_FANOUT_EBPF)
    361 		sock_fanout_set_ebpf(fds[0]);
    362 
    363 	rings[0] = sock_fanout_open_ring(fds[0]);
    364 	rings[1] = sock_fanout_open_ring(fds[1]);
    365 	pair_udp_open(fds_udp[0], PORT_BASE);
    366 	pair_udp_open(fds_udp[1], PORT_BASE + port_off);
    367 	sock_fanout_read(fds, rings, expect0);
    368 
    369 	/* Send data, but not enough to overflow a queue */
    370 	pair_udp_send(fds_udp[0], 15);
    371 	pair_udp_send_char(fds_udp[1], 5, DATA_CHAR_1);
    372 	ret = sock_fanout_read(fds, rings, expect1);
    373 
    374 	/* Send more data, overflow the queue */
    375 	pair_udp_send_char(fds_udp[0], 15, DATA_CHAR_1);
    376 	/* TODO: ensure consistent order between expect1 and expect2 */
    377 	ret |= sock_fanout_read(fds, rings, expect2);
    378 
    379 	if (munmap(rings[1], RING_NUM_FRAMES * getpagesize()) ||
    380 	    munmap(rings[0], RING_NUM_FRAMES * getpagesize())) {
    381 		fprintf(stderr, "close rings\n");
    382 		exit(1);
    383 	}
    384 	if (close(fds_udp[1][1]) || close(fds_udp[1][0]) ||
    385 	    close(fds_udp[0][1]) || close(fds_udp[0][0]) ||
    386 	    close(fds[1]) || close(fds[0])) {
    387 		fprintf(stderr, "close datapath\n");
    388 		exit(1);
    389 	}
    390 
    391 	return ret;
    392 }
    393 
    394 static int set_cpuaffinity(int cpuid)
    395 {
    396 	cpu_set_t mask;
    397 
    398 	CPU_ZERO(&mask);
    399 	CPU_SET(cpuid, &mask);
    400 	if (sched_setaffinity(0, sizeof(mask), &mask)) {
    401 		if (errno != EINVAL) {
    402 			fprintf(stderr, "setaffinity %d\n", cpuid);
    403 			exit(1);
    404 		}
    405 		return 1;
    406 	}
    407 
    408 	return 0;
    409 }
    410 
    411 int main(int argc, char **argv)
    412 {
    413 	const int expect_hash[2][2]	= { { 15, 5 },  { 20, 5 } };
    414 	const int expect_hash_rb[2][2]	= { { 15, 5 },  { 20, 15 } };
    415 	const int expect_lb[2][2]	= { { 10, 10 }, { 18, 17 } };
    416 	const int expect_rb[2][2]	= { { 15, 5 },  { 20, 15 } };
    417 	const int expect_cpu0[2][2]	= { { 20, 0 },  { 20, 0 } };
    418 	const int expect_cpu1[2][2]	= { { 0, 20 },  { 0, 20 } };
    419 	const int expect_bpf[2][2]	= { { 15, 5 },  { 15, 20 } };
    420 	const int expect_uniqueid[2][2] = { { 20, 20},  { 20, 20 } };
    421 	int port_off = 2, tries = 5, ret;
    422 
    423 	test_control_single();
    424 	test_control_group();
    425 	test_unique_fanout_group_ids();
    426 
    427 	/* find a set of ports that do not collide onto the same socket */
    428 	ret = test_datapath(PACKET_FANOUT_HASH, port_off,
    429 			    expect_hash[0], expect_hash[1]);
    430 	while (ret && tries--) {
    431 		fprintf(stderr, "info: trying alternate ports (%d)\n", tries);
    432 		ret = test_datapath(PACKET_FANOUT_HASH, ++port_off,
    433 				    expect_hash[0], expect_hash[1]);
    434 	}
    435 
    436 	ret |= test_datapath(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_ROLLOVER,
    437 			     port_off, expect_hash_rb[0], expect_hash_rb[1]);
    438 	ret |= test_datapath(PACKET_FANOUT_LB,
    439 			     port_off, expect_lb[0], expect_lb[1]);
    440 	ret |= test_datapath(PACKET_FANOUT_ROLLOVER,
    441 			     port_off, expect_rb[0], expect_rb[1]);
    442 
    443 	ret |= test_datapath(PACKET_FANOUT_CBPF,
    444 			     port_off, expect_bpf[0], expect_bpf[1]);
    445 	ret |= test_datapath(PACKET_FANOUT_EBPF,
    446 			     port_off, expect_bpf[0], expect_bpf[1]);
    447 
    448 	set_cpuaffinity(0);
    449 	ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
    450 			     expect_cpu0[0], expect_cpu0[1]);
    451 	if (!set_cpuaffinity(1))
    452 		/* TODO: test that choice alternates with previous */
    453 		ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
    454 				     expect_cpu1[0], expect_cpu1[1]);
    455 
    456 	ret |= test_datapath(PACKET_FANOUT_FLAG_UNIQUEID, port_off,
    457 			     expect_uniqueid[0], expect_uniqueid[1]);
    458 
    459 	if (ret)
    460 		return 1;
    461 
    462 	printf("OK. All tests passed\n");
    463 	return 0;
    464 }
    465