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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, 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