// 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/ioctl.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;

static void loopback_set_up_down(int state_up)
{
        struct ifreq ifreq = {};
        int fd, err;

        fd = socket(AF_PACKET, SOCK_RAW, 0);
        if (fd < 0) {
                perror("socket loopback");
                exit(1);
        }
        strcpy(ifreq.ifr_name, "lo");
        err = ioctl(fd, SIOCGIFFLAGS, &ifreq);
        if (err) {
                perror("SIOCGIFFLAGS");
                exit(1);
        }
        if (state_up != !!(ifreq.ifr_flags & IFF_UP)) {
                ifreq.ifr_flags ^= IFF_UP;
                err = ioctl(fd, SIOCSIFFLAGS, &ifreq);
                if (err) {
                        perror("SIOCSIFFLAGS");
                        exit(1);
                }
        }
        close(fd);
}

/* 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 that creating/joining a fanout group fails for unbound socket without
 * a specified protocol
 */
static void test_unbound_fanout(void)
{
        int val, fd0, fd1, err;

        fprintf(stderr, "test: unbound fanout\n");
        fd0 = socket(PF_PACKET, SOCK_RAW, 0);
        if (fd0 < 0) {
                perror("socket packet");
                exit(1);
        }
        /* Try to create a new fanout group. Should fail. */
        val = (PACKET_FANOUT_HASH << 16) | 1;
        err = setsockopt(fd0, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val));
        if (!err) {
                fprintf(stderr, "ERROR: unbound socket fanout create\n");
                exit(1);
        }
        fd1 = sock_fanout_open(PACKET_FANOUT_HASH, 1);
        if (fd1 == -1) {
                fprintf(stderr, "ERROR: failed to open HASH socket\n");
                exit(1);
        }
        /* Try to join an existing fanout group. Should fail. */
        err = setsockopt(fd0, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val));
        if (!err) {
                fprintf(stderr, "ERROR: unbound socket fanout join\n");
                exit(1);
        }
        close(fd0);
        close(fd1);
}

/* 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(int toggle)
{
        int fds[2];

        if (toggle)
                fprintf(stderr, "test: control multiple sockets with link down toggle\n");
        else
                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 (toggle)
                loopback_set_up_down(0);
        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 (toggle)
                loopback_set_up_down(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_unbound_fanout();
        test_control_single();
        test_control_group(0);
        test_control_group(1);
        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;
}