psock_fanout.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2013 Google Inc.
 * Author: Willem de Bruijn (willemb@google.com)
 *
 * A basic test of packet socket fanout behavior.
 *
 * Control:
 * - create fanout fails as expected with illegal flag combinations
 * - join   fanout fails as expected with diverging types or flags
 *
 * Datapath:
 *   Open a pair of packet sockets and a pair of INET sockets, send a known
 *   number of packets across the two INET sockets and count the number of
 *   packets enqueued onto the two packet sockets.
 *
 *   The test currently runs for
 *   - PACKET_FANOUT_HASH
 *   - PACKET_FANOUT_HASH with PACKET_FANOUT_FLAG_ROLLOVER
 *   - PACKET_FANOUT_LB
 *   - PACKET_FANOUT_CPU
 *   - PACKET_FANOUT_ROLLOVER
 *   - PACKET_FANOUT_CBPF
 *   - PACKET_FANOUT_EBPF
 *
 * Todo:
 * - functionality: PACKET_FANOUT_FLAG_DEFRAG
 */

#define _GNU_SOURCE		/* for sched_setaffinity */

#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/unistd.h>	/* for __NR_bpf */
#include <linux/filter.h>
#include <linux/bpf.h>
#include <linux/if_packet.h>
#include <net/if.h>
#include <net/ethernet.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <poll.h>
#include <sched.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "psock_lib.h"
#include "../kselftest.h"

#define RING_NUM_FRAMES			20

static uint32_t cfg_max_num_members;

/* Open a socket in a given fanout mode.
 * @return -1 if mode is bad, a valid socket otherwise */
static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)
{
	struct sockaddr_ll addr = {0};
	struct fanout_args args;
	int fd, val, err;

	fd = socket(PF_PACKET, SOCK_RAW, 0);
	if (fd < 0) {
		perror("socket packet");
		exit(1);
	}

	pair_udp_setfilter(fd);

	addr.sll_family = AF_PACKET;
	addr.sll_protocol = htons(ETH_P_IP);
	addr.sll_ifindex = if_nametoindex("lo");
	if (addr.sll_ifindex == 0) {
		perror("if_nametoindex");
		exit(1);
	}
	if (bind(fd, (void *) &addr, sizeof(addr))) {
		perror("bind packet");
		exit(1);
	}

	if (cfg_max_num_members) {
		args.id = group_id;
		args.type_flags = typeflags;
		args.max_num_members = cfg_max_num_members;
		err = setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &args,
				 sizeof(args));
	} else {
		val = (((int) typeflags) << 16) | group_id;
		err = setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &val,
				 sizeof(val));
	}
	if (err) {
		if (close(fd)) {
			perror("close packet");
			exit(1);
		}
		return -1;
	}

	return fd;
}

static void sock_fanout_set_cbpf(int fd)
{
	struct sock_filter bpf_filter[] = {
		BPF_STMT(BPF_LD | BPF_B | BPF_ABS, 80),	      /* ldb [80] */
		BPF_STMT(BPF_RET | BPF_A, 0),		      /* ret A */
	};
	struct sock_fprog bpf_prog;

	bpf_prog.filter = bpf_filter;
	bpf_prog.len = ARRAY_SIZE(bpf_filter);

	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &bpf_prog,
		       sizeof(bpf_prog))) {
		perror("fanout data cbpf");
		exit(1);
	}
}

static void sock_fanout_getopts(int fd, uint16_t *typeflags, uint16_t *group_id)
{
	int sockopt;
	socklen_t sockopt_len = sizeof(sockopt);

	if (getsockopt(fd, SOL_PACKET, PACKET_FANOUT,
		       &sockopt, &sockopt_len)) {
		perror("failed to getsockopt");
		exit(1);
	}
	*typeflags = sockopt >> 16;
	*group_id = sockopt & 0xfffff;
}

static void sock_fanout_set_ebpf(int fd)
{
	static char log_buf[65536];

	const int len_off = __builtin_offsetof(struct __sk_buff, len);
	struct bpf_insn prog[] = {
		{ BPF_ALU64 | BPF_MOV | BPF_X,   6, 1, 0, 0 },
		{ BPF_LDX   | BPF_W   | BPF_MEM, 0, 6, len_off, 0 },
		{ BPF_JMP   | BPF_JGE | BPF_K,   0, 0, 1, DATA_LEN },
		{ BPF_JMP   | BPF_JA  | BPF_K,   0, 0, 4, 0 },
		{ BPF_LD    | BPF_B   | BPF_ABS, 0, 0, 0, 0x50 },
		{ BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 2, DATA_CHAR },
		{ BPF_JMP   | BPF_JEQ | BPF_K,   0, 0, 1, DATA_CHAR_1 },
		{ BPF_ALU   | BPF_MOV | BPF_K,   0, 0, 0, 0 },
		{ BPF_JMP   | BPF_EXIT,          0, 0, 0, 0 }
	};
	union bpf_attr attr;
	int pfd;

	memset(&attr, 0, sizeof(attr));
	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
	attr.insns = (unsigned long) prog;
	attr.insn_cnt = ARRAY_SIZE(prog);
	attr.license = (unsigned long) "GPL";
	attr.log_buf = (unsigned long) log_buf,
	attr.log_size = sizeof(log_buf),
	attr.log_level = 1,

	pfd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
	if (pfd < 0) {
		perror("bpf");
		fprintf(stderr, "bpf verifier:\n%s\n", log_buf);
		exit(1);
	}

	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &pfd, sizeof(pfd))) {
		perror("fanout data ebpf");
		exit(1);
	}

	if (close(pfd)) {
		perror("close ebpf");
		exit(1);
	}
}

static char *sock_fanout_open_ring(int fd)
{
	struct tpacket_req req = {
		.tp_block_size = getpagesize(),
		.tp_frame_size = getpagesize(),
		.tp_block_nr   = RING_NUM_FRAMES,
		.tp_frame_nr   = RING_NUM_FRAMES,
	};
	char *ring;
	int val = TPACKET_V2;

	if (setsockopt(fd, SOL_PACKET, PACKET_VERSION, (void *) &val,
		       sizeof(val))) {
		perror("packetsock ring setsockopt version");
		exit(1);
	}
	if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING, (void *) &req,
		       sizeof(req))) {
		perror("packetsock ring setsockopt");
		exit(1);
	}

	ring = mmap(0, req.tp_block_size * req.tp_block_nr,
		    PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
	if (ring == MAP_FAILED) {
		perror("packetsock ring mmap");
		exit(1);
	}

	return ring;
}

static int sock_fanout_read_ring(int fd, void *ring)
{
	struct tpacket2_hdr *header = ring;
	int count = 0;

	while (count < RING_NUM_FRAMES && header->tp_status & TP_STATUS_USER) {
		count++;
		header = ring + (count * getpagesize());
	}

	return count;
}

static int sock_fanout_read(int fds[], char *rings[], const int expect[])
{
	int ret[2];

	ret[0] = sock_fanout_read_ring(fds[0], rings[0]);
	ret[1] = sock_fanout_read_ring(fds[1], rings[1]);

	fprintf(stderr, "info: count=%d,%d, expect=%d,%d\n",
			ret[0], ret[1], expect[0], expect[1]);

	if ((!(ret[0] == expect[0] && ret[1] == expect[1])) &&
	    (!(ret[0] == expect[1] && ret[1] == expect[0]))) {
		fprintf(stderr, "warning: incorrect queue lengths\n");
		return 1;
	}

	return 0;
}

/* Test illegal mode + flag combination */
static void test_control_single(void)
{
	fprintf(stderr, "test: control single socket\n");

	if (sock_fanout_open(PACKET_FANOUT_ROLLOVER |
			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
		fprintf(stderr, "ERROR: opened socket with dual rollover\n");
		exit(1);
	}
}

/* Test illegal group with different modes or flags */
static void test_control_group(void)
{
	int fds[2];

	fprintf(stderr, "test: control multiple sockets\n");

	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
	if (fds[0] == -1) {
		fprintf(stderr, "ERROR: failed to open HASH socket\n");
		exit(1);
	}
	if (sock_fanout_open(PACKET_FANOUT_HASH |
			       PACKET_FANOUT_FLAG_DEFRAG, 0) != -1) {
		fprintf(stderr, "ERROR: joined group with wrong flag defrag\n");
		exit(1);
	}
	if (sock_fanout_open(PACKET_FANOUT_HASH |
			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {
		fprintf(stderr, "ERROR: joined group with wrong flag ro\n");
		exit(1);
	}
	if (sock_fanout_open(PACKET_FANOUT_CPU, 0) != -1) {
		fprintf(stderr, "ERROR: joined group with wrong mode\n");
		exit(1);
	}
	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
	if (fds[1] == -1) {
		fprintf(stderr, "ERROR: failed to join group\n");
		exit(1);
	}
	if (close(fds[1]) || close(fds[0])) {
		fprintf(stderr, "ERROR: closing sockets\n");
		exit(1);
	}
}

/* Test illegal max_num_members values */
static void test_control_group_max_num_members(void)
{
	int fds[3];

	fprintf(stderr, "test: control multiple sockets, max_num_members\n");

	/* expected failure on greater than PACKET_FANOUT_MAX */
	cfg_max_num_members = (1 << 16) + 1;
	if (sock_fanout_open(PACKET_FANOUT_HASH, 0) != -1) {
		fprintf(stderr, "ERROR: max_num_members > PACKET_FANOUT_MAX\n");
		exit(1);
	}

	cfg_max_num_members = 256;
	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
	if (fds[0] == -1) {
		fprintf(stderr, "ERROR: failed open\n");
		exit(1);
	}

	/* expected failure on joining group with different max_num_members */
	cfg_max_num_members = 257;
	if (sock_fanout_open(PACKET_FANOUT_HASH, 0) != -1) {
		fprintf(stderr, "ERROR: set different max_num_members\n");
		exit(1);
	}

	/* success on joining group with same max_num_members */
	cfg_max_num_members = 256;
	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
	if (fds[1] == -1) {
		fprintf(stderr, "ERROR: failed to join group\n");
		exit(1);
	}

	/* success on joining group with max_num_members unspecified */
	cfg_max_num_members = 0;
	fds[2] = sock_fanout_open(PACKET_FANOUT_HASH, 0);
	if (fds[2] == -1) {
		fprintf(stderr, "ERROR: failed to join group\n");
		exit(1);
	}

	if (close(fds[2]) || close(fds[1]) || close(fds[0])) {
		fprintf(stderr, "ERROR: closing sockets\n");
		exit(1);
	}
}

/* Test creating a unique fanout group ids */
static void test_unique_fanout_group_ids(void)
{
	int fds[3];
	uint16_t typeflags, first_group_id, second_group_id;

	fprintf(stderr, "test: unique ids\n");

	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH |
				  PACKET_FANOUT_FLAG_UNIQUEID, 0);
	if (fds[0] == -1) {
		fprintf(stderr, "ERROR: failed to create a unique id group.\n");
		exit(1);
	}

	sock_fanout_getopts(fds[0], &typeflags, &first_group_id);
	if (typeflags != PACKET_FANOUT_HASH) {
		fprintf(stderr, "ERROR: unexpected typeflags %x\n", typeflags);
		exit(1);
	}

	if (sock_fanout_open(PACKET_FANOUT_CPU, first_group_id) != -1) {
		fprintf(stderr, "ERROR: joined group with wrong type.\n");
		exit(1);
	}

	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, first_group_id);
	if (fds[1] == -1) {
		fprintf(stderr,
			"ERROR: failed to join previously created group.\n");
		exit(1);
	}

	fds[2] = sock_fanout_open(PACKET_FANOUT_HASH |
				  PACKET_FANOUT_FLAG_UNIQUEID, 0);
	if (fds[2] == -1) {
		fprintf(stderr,
			"ERROR: failed to create a second unique id group.\n");
		exit(1);
	}

	sock_fanout_getopts(fds[2], &typeflags, &second_group_id);
	if (sock_fanout_open(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_UNIQUEID,
			     second_group_id) != -1) {
		fprintf(stderr,
			"ERROR: specified a group id when requesting unique id\n");
		exit(1);
	}

	if (close(fds[0]) || close(fds[1]) || close(fds[2])) {
		fprintf(stderr, "ERROR: closing sockets\n");
		exit(1);
	}
}

static int test_datapath(uint16_t typeflags, int port_off,
			 const int expect1[], const int expect2[])
{
	const int expect0[] = { 0, 0 };
	char *rings[2];
	uint8_t type = typeflags & 0xFF;
	int fds[2], fds_udp[2][2], ret;

	fprintf(stderr, "\ntest: datapath 0x%hx ports %hu,%hu\n",
		typeflags, (uint16_t)PORT_BASE,
		(uint16_t)(PORT_BASE + port_off));

	fds[0] = sock_fanout_open(typeflags, 0);
	fds[1] = sock_fanout_open(typeflags, 0);
	if (fds[0] == -1 || fds[1] == -1) {
		fprintf(stderr, "ERROR: failed open\n");
		exit(1);
	}
	if (type == PACKET_FANOUT_CBPF)
		sock_fanout_set_cbpf(fds[0]);
	else if (type == PACKET_FANOUT_EBPF)
		sock_fanout_set_ebpf(fds[0]);

	rings[0] = sock_fanout_open_ring(fds[0]);
	rings[1] = sock_fanout_open_ring(fds[1]);
	pair_udp_open(fds_udp[0], PORT_BASE);
	pair_udp_open(fds_udp[1], PORT_BASE + port_off);
	sock_fanout_read(fds, rings, expect0);

	/* Send data, but not enough to overflow a queue */
	pair_udp_send(fds_udp[0], 15);
	pair_udp_send_char(fds_udp[1], 5, DATA_CHAR_1);
	ret = sock_fanout_read(fds, rings, expect1);

	/* Send more data, overflow the queue */
	pair_udp_send_char(fds_udp[0], 15, DATA_CHAR_1);
	/* TODO: ensure consistent order between expect1 and expect2 */
	ret |= sock_fanout_read(fds, rings, expect2);

	if (munmap(rings[1], RING_NUM_FRAMES * getpagesize()) ||
	    munmap(rings[0], RING_NUM_FRAMES * getpagesize())) {
		fprintf(stderr, "close rings\n");
		exit(1);
	}
	if (close(fds_udp[1][1]) || close(fds_udp[1][0]) ||
	    close(fds_udp[0][1]) || close(fds_udp[0][0]) ||
	    close(fds[1]) || close(fds[0])) {
		fprintf(stderr, "close datapath\n");
		exit(1);
	}

	return ret;
}

static int set_cpuaffinity(int cpuid)
{
	cpu_set_t mask;

	CPU_ZERO(&mask);
	CPU_SET(cpuid, &mask);
	if (sched_setaffinity(0, sizeof(mask), &mask)) {
		if (errno != EINVAL) {
			fprintf(stderr, "setaffinity %d\n", cpuid);
			exit(1);
		}
		return 1;
	}

	return 0;
}

int main(int argc, char **argv)
{
	const int expect_hash[2][2]	= { { 15, 5 },  { 20, 5 } };
	const int expect_hash_rb[2][2]	= { { 15, 5 },  { 20, 15 } };
	const int expect_lb[2][2]	= { { 10, 10 }, { 18, 17 } };
	const int expect_rb[2][2]	= { { 15, 5 },  { 20, 15 } };
	const int expect_cpu0[2][2]	= { { 20, 0 },  { 20, 0 } };
	const int expect_cpu1[2][2]	= { { 0, 20 },  { 0, 20 } };
	const int expect_bpf[2][2]	= { { 15, 5 },  { 15, 20 } };
	const int expect_uniqueid[2][2] = { { 20, 20},  { 20, 20 } };
	int port_off = 2, tries = 20, ret;

	test_control_single();
	test_control_group();
	test_control_group_max_num_members();
	test_unique_fanout_group_ids();

	/* PACKET_FANOUT_MAX */
	cfg_max_num_members = 1 << 16;
	/* find a set of ports that do not collide onto the same socket */
	ret = test_datapath(PACKET_FANOUT_HASH, port_off,
			    expect_hash[0], expect_hash[1]);
	while (ret) {
		fprintf(stderr, "info: trying alternate ports (%d)\n", tries);
		ret = test_datapath(PACKET_FANOUT_HASH, ++port_off,
				    expect_hash[0], expect_hash[1]);
		if (!--tries) {
			fprintf(stderr, "too many collisions\n");
			return 1;
		}
	}

	ret |= test_datapath(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_ROLLOVER,
			     port_off, expect_hash_rb[0], expect_hash_rb[1]);
	ret |= test_datapath(PACKET_FANOUT_LB,
			     port_off, expect_lb[0], expect_lb[1]);
	ret |= test_datapath(PACKET_FANOUT_ROLLOVER,
			     port_off, expect_rb[0], expect_rb[1]);

	ret |= test_datapath(PACKET_FANOUT_CBPF,
			     port_off, expect_bpf[0], expect_bpf[1]);
	ret |= test_datapath(PACKET_FANOUT_EBPF,
			     port_off, expect_bpf[0], expect_bpf[1]);

	set_cpuaffinity(0);
	ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
			     expect_cpu0[0], expect_cpu0[1]);
	if (!set_cpuaffinity(1))
		/* TODO: test that choice alternates with previous */
		ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
				     expect_cpu1[0], expect_cpu1[1]);

	ret |= test_datapath(PACKET_FANOUT_FLAG_UNIQUEID, port_off,
			     expect_uniqueid[0], expect_uniqueid[1]);

	if (ret)
		return 1;

	printf("OK. All tests passed\n");
	return 0;
}