// SPDX-License-Identifier: GPL-2.0
/*
 * Test the SO_TXTIME API
 *
 * Takes a stream of { payload, delivery time }[], to be sent across two
 * processes. Start this program on two separate network namespaces or
 * connected hosts, one instance in transmit mode and the other in receive
 * mode using the '-r' option. Receiver will compare arrival timestamps to
 * the expected stream. Sender will read transmit timestamps from the error
 * queue. The streams can differ due to out-of-order delivery and drops.
 */

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <error.h>
#include <errno.h>
#include <inttypes.h>
#include <linux/net_tstamp.h>
#include <linux/errqueue.h>
#include <linux/if_ether.h>
#include <linux/ipv6.h>
#include <linux/udp.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <poll.h>

static int      cfg_clockid     = CLOCK_TAI;
static uint16_t cfg_port        = 8000;
static int      cfg_variance_us = 4000;
static uint64_t cfg_start_time_ns;
static int      cfg_mark;
static bool     cfg_rx;

static uint64_t glob_tstart;
static uint64_t tdeliver_max;

/* encode one timed transmission (of a 1B payload) */
struct timed_send {
        char    data;
        int64_t delay_us;
};

#define MAX_NUM_PKT     8
static struct timed_send cfg_buf[MAX_NUM_PKT];
static int cfg_num_pkt;

static int cfg_errq_level;
static int cfg_errq_type;

static struct sockaddr_storage cfg_dst_addr;
static struct sockaddr_storage cfg_src_addr;
static socklen_t cfg_alen;

static uint64_t gettime_ns(clockid_t clock)
{
        struct timespec ts;

        if (clock_gettime(clock, &ts))
                error(1, errno, "gettime");

        return ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec;
}

static void do_send_one(int fdt, struct timed_send *ts)
{
        char control[CMSG_SPACE(sizeof(uint64_t))];
        struct msghdr msg = {0};
        struct iovec iov = {0};
        struct cmsghdr *cm;
        uint64_t tdeliver;
        int ret;

        iov.iov_base = &ts->data;
        iov.iov_len = 1;

        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
        msg.msg_name = (struct sockaddr *)&cfg_dst_addr;
        msg.msg_namelen = cfg_alen;

        if (ts->delay_us >= 0) {
                memset(control, 0, sizeof(control));
                msg.msg_control = &control;
                msg.msg_controllen = sizeof(control);

                tdeliver = glob_tstart + ts->delay_us * 1000;
                tdeliver_max = tdeliver_max > tdeliver ?
                               tdeliver_max : tdeliver;

                cm = CMSG_FIRSTHDR(&msg);
                cm->cmsg_level = SOL_SOCKET;
                cm->cmsg_type = SCM_TXTIME;
                cm->cmsg_len = CMSG_LEN(sizeof(tdeliver));
                memcpy(CMSG_DATA(cm), &tdeliver, sizeof(tdeliver));
        }

        ret = sendmsg(fdt, &msg, 0);
        if (ret == -1)
                error(1, errno, "write");
        if (ret == 0)
                error(1, 0, "write: 0B");

}

static void do_recv_one(int fdr, struct timed_send *ts)
{
        int64_t tstop, texpect;
        char rbuf[2];
        int ret;

        ret = recv(fdr, rbuf, sizeof(rbuf), 0);
        if (ret == -1 && errno == EAGAIN)
                error(1, EAGAIN, "recv: timeout");
        if (ret == -1)
                error(1, errno, "read");
        if (ret != 1)
                error(1, 0, "read: %dB", ret);

        tstop = (gettime_ns(cfg_clockid) - glob_tstart) / 1000;
        texpect = ts->delay_us >= 0 ? ts->delay_us : 0;

        fprintf(stderr, "payload:%c delay:%lld expected:%lld (us)\n",
                        rbuf[0], (long long)tstop, (long long)texpect);

        if (rbuf[0] != ts->data)
                error(1, 0, "payload mismatch. expected %c", ts->data);

        if (llabs(tstop - texpect) > cfg_variance_us) {
                fprintf(stderr, "exceeds variance (%d us)\n", cfg_variance_us);
                if (!getenv("KSFT_MACHINE_SLOW"))
                        exit(1);
        }
}

static void do_recv_verify_empty(int fdr)
{
        char rbuf[1];
        int ret;

        ret = recv(fdr, rbuf, sizeof(rbuf), 0);
        if (ret != -1 || errno != EAGAIN)
                error(1, 0, "recv: not empty as expected (%d, %d)", ret, errno);
}

static int do_recv_errqueue_timeout(int fdt)
{
        char control[CMSG_SPACE(sizeof(struct sock_extended_err)) +
                     CMSG_SPACE(sizeof(struct sockaddr_in6))] = {0};
        char data[sizeof(struct ethhdr) + sizeof(struct ipv6hdr) +
                  sizeof(struct udphdr) + 1];
        struct sock_extended_err *err;
        int ret, num_tstamp = 0;
        struct msghdr msg = {0};
        struct iovec iov = {0};
        struct cmsghdr *cm;
        int64_t tstamp = 0;

        iov.iov_base = data;
        iov.iov_len = sizeof(data);

        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;

        msg.msg_control = control;
        msg.msg_controllen = sizeof(control);

        while (1) {
                const char *reason = NULL;

                ret = recvmsg(fdt, &msg, MSG_ERRQUEUE);
                if (ret == -1 && errno == EAGAIN)
                        break;
                if (ret == -1)
                        error(1, errno, "errqueue");
                if (msg.msg_flags != MSG_ERRQUEUE)
                        error(1, 0, "errqueue: flags 0x%x\n", msg.msg_flags);

                cm = CMSG_FIRSTHDR(&msg);
                if (cm->cmsg_level != cfg_errq_level ||
                    cm->cmsg_type != cfg_errq_type)
                        error(1, 0, "errqueue: type 0x%x.0x%x\n",
                                    cm->cmsg_level, cm->cmsg_type);

                err = (struct sock_extended_err *)CMSG_DATA(cm);
                if (err->ee_origin != SO_EE_ORIGIN_TXTIME)
                        error(1, 0, "errqueue: origin 0x%x\n", err->ee_origin);

                switch (err->ee_errno) {
                case ECANCELED:
                        if (err->ee_code != SO_EE_CODE_TXTIME_MISSED)
                                error(1, 0, "errqueue: unknown ECANCELED %u\n",
                                      err->ee_code);
                        reason = "missed txtime";
                break;
                case EINVAL:
                        if (err->ee_code != SO_EE_CODE_TXTIME_INVALID_PARAM)
                                error(1, 0, "errqueue: unknown EINVAL %u\n",
                                      err->ee_code);
                        reason = "invalid txtime";
                break;
                default:
                        error(1, 0, "errqueue: errno %u code %u\n",
                              err->ee_errno, err->ee_code);
                }

                tstamp = ((int64_t) err->ee_data) << 32 | err->ee_info;
                tstamp -= (int64_t) glob_tstart;
                tstamp /= 1000 * 1000;
                fprintf(stderr, "send: pkt %c at %" PRId64 "ms dropped: %s\n",
                        data[ret - 1], tstamp, reason);

                msg.msg_flags = 0;
                msg.msg_controllen = sizeof(control);
                num_tstamp++;
        }

        return num_tstamp;
}

static void recv_errqueue_msgs(int fdt)
{
        struct pollfd pfd = { .fd = fdt, .events = POLLERR };
        const int timeout_ms = 10;
        int ret, num_tstamp = 0;

        do {
                ret = poll(&pfd, 1, timeout_ms);
                if (ret == -1)
                        error(1, errno, "poll");

                if (ret && (pfd.revents & POLLERR))
                        num_tstamp += do_recv_errqueue_timeout(fdt);

                if (num_tstamp == cfg_num_pkt)
                        break;

        } while (gettime_ns(cfg_clockid) < tdeliver_max);
}

static void start_time_wait(void)
{
        uint64_t now;
        int err;

        if (!cfg_start_time_ns)
                return;

        now = gettime_ns(CLOCK_REALTIME);
        if (cfg_start_time_ns < now)
                return;

        err = usleep((cfg_start_time_ns - now) / 1000);
        if (err)
                error(1, errno, "usleep");
}

static void setsockopt_txtime(int fd)
{
        struct sock_txtime so_txtime_val = { .clockid = cfg_clockid };
        struct sock_txtime so_txtime_val_read = { 0 };
        socklen_t vallen = sizeof(so_txtime_val);

        so_txtime_val.flags = SOF_TXTIME_REPORT_ERRORS;

        if (setsockopt(fd, SOL_SOCKET, SO_TXTIME,
                       &so_txtime_val, sizeof(so_txtime_val)))
                error(1, errno, "setsockopt txtime");

        if (getsockopt(fd, SOL_SOCKET, SO_TXTIME,
                       &so_txtime_val_read, &vallen))
                error(1, errno, "getsockopt txtime");

        if (vallen != sizeof(so_txtime_val) ||
            memcmp(&so_txtime_val, &so_txtime_val_read, vallen))
                error(1, 0, "getsockopt txtime: mismatch");
}

static int setup_tx(struct sockaddr *addr, socklen_t alen)
{
        int fd;

        fd = socket(addr->sa_family, SOCK_DGRAM, 0);
        if (fd == -1)
                error(1, errno, "socket t");

        if (connect(fd, addr, alen))
                error(1, errno, "connect");

        setsockopt_txtime(fd);

        if (cfg_mark &&
            setsockopt(fd, SOL_SOCKET, SO_MARK, &cfg_mark, sizeof(cfg_mark)))
                error(1, errno, "setsockopt mark");

        return fd;
}

static int setup_rx(struct sockaddr *addr, socklen_t alen)
{
        struct timeval tv = { .tv_usec = 100 * 1000 };
        int fd;

        fd = socket(addr->sa_family, SOCK_DGRAM, 0);
        if (fd == -1)
                error(1, errno, "socket r");

        if (bind(fd, addr, alen))
                error(1, errno, "bind");

        if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)))
                error(1, errno, "setsockopt rcv timeout");

        return fd;
}

static void do_test_tx(struct sockaddr *addr, socklen_t alen)
{
        int fdt, i;

        fprintf(stderr, "\nSO_TXTIME ipv%c clock %s\n",
                        addr->sa_family == PF_INET ? '4' : '6',
                        cfg_clockid == CLOCK_TAI ? "tai" : "monotonic");

        fdt = setup_tx(addr, alen);

        start_time_wait();
        glob_tstart = gettime_ns(cfg_clockid);

        for (i = 0; i < cfg_num_pkt; i++)
                do_send_one(fdt, &cfg_buf[i]);

        recv_errqueue_msgs(fdt);

        if (close(fdt))
                error(1, errno, "close t");
}

static void do_test_rx(struct sockaddr *addr, socklen_t alen)
{
        int fdr, i;

        fdr = setup_rx(addr, alen);

        start_time_wait();
        glob_tstart = gettime_ns(cfg_clockid);

        for (i = 0; i < cfg_num_pkt; i++)
                do_recv_one(fdr, &cfg_buf[i]);

        do_recv_verify_empty(fdr);

        if (close(fdr))
                error(1, errno, "close r");
}

static void setup_sockaddr(int domain, const char *str_addr,
                           struct sockaddr_storage *sockaddr)
{
        struct sockaddr_in6 *addr6 = (void *) sockaddr;
        struct sockaddr_in *addr4 = (void *) sockaddr;

        switch (domain) {
        case PF_INET:
                memset(addr4, 0, sizeof(*addr4));
                addr4->sin_family = AF_INET;
                addr4->sin_port = htons(cfg_port);
                if (str_addr &&
                    inet_pton(AF_INET, str_addr, &(addr4->sin_addr)) != 1)
                        error(1, 0, "ipv4 parse error: %s", str_addr);
                break;
        case PF_INET6:
                memset(addr6, 0, sizeof(*addr6));
                addr6->sin6_family = AF_INET6;
                addr6->sin6_port = htons(cfg_port);
                if (str_addr &&
                    inet_pton(AF_INET6, str_addr, &(addr6->sin6_addr)) != 1)
                        error(1, 0, "ipv6 parse error: %s", str_addr);
                break;
        }
}

static int parse_io(const char *optarg, struct timed_send *array)
{
        char *arg, *tok;
        int aoff = 0;

        arg = strdup(optarg);
        if (!arg)
                error(1, errno, "strdup");

        while ((tok = strtok(arg, ","))) {
                arg = NULL;     /* only pass non-zero on first call */

                if (aoff / 2 == MAX_NUM_PKT)
                        error(1, 0, "exceeds max pkt count (%d)", MAX_NUM_PKT);

                if (aoff & 1) { /* parse delay */
                        array->delay_us = strtol(tok, NULL, 0) * 1000;
                        array++;
                } else {        /* parse character */
                        array->data = tok[0];
                }

                aoff++;
        }

        free(arg);

        return aoff / 2;
}

static void usage(const char *progname)
{
        fprintf(stderr, "\nUsage: %s [options] <payload>\n"
                        "Options:\n"
                        "  -4            only IPv4\n"
                        "  -6            only IPv6\n"
                        "  -c <clock>    monotonic or tai (default)\n"
                        "  -D <addr>     destination IP address (server)\n"
                        "  -S <addr>     source IP address (client)\n"
                        "  -r            run rx mode\n"
                        "  -t <nsec>     start time (UTC nanoseconds)\n"
                        "  -m <mark>     socket mark\n"
                        "\n",
                        progname);
        exit(1);
}

static void parse_opts(int argc, char **argv)
{
        char *daddr = NULL, *saddr = NULL;
        int domain = PF_UNSPEC;
        int c;

        while ((c = getopt(argc, argv, "46c:S:D:rt:m:")) != -1) {
                switch (c) {
                case '4':
                        if (domain != PF_UNSPEC)
                                error(1, 0, "Pass one of -4 or -6");
                        domain = PF_INET;
                        cfg_alen = sizeof(struct sockaddr_in);
                        cfg_errq_level = SOL_IP;
                        cfg_errq_type = IP_RECVERR;
                        break;
                case '6':
                        if (domain != PF_UNSPEC)
                                error(1, 0, "Pass one of -4 or -6");
                        domain = PF_INET6;
                        cfg_alen = sizeof(struct sockaddr_in6);
                        cfg_errq_level = SOL_IPV6;
                        cfg_errq_type = IPV6_RECVERR;
                        break;
                case 'c':
                        if (!strcmp(optarg, "tai"))
                                cfg_clockid = CLOCK_TAI;
                        else if (!strcmp(optarg, "monotonic") ||
                                 !strcmp(optarg, "mono"))
                                cfg_clockid = CLOCK_MONOTONIC;
                        else
                                error(1, 0, "unknown clock id %s", optarg);
                        break;
                case 'S':
                        saddr = optarg;
                        break;
                case 'D':
                        daddr = optarg;
                        break;
                case 'r':
                        cfg_rx = true;
                        break;
                case 't':
                        cfg_start_time_ns = strtoll(optarg, NULL, 0);
                        break;
                case 'm':
                        cfg_mark = strtol(optarg, NULL, 0);
                        break;
                default:
                        usage(argv[0]);
                }
        }

        if (argc - optind != 1)
                usage(argv[0]);

        if (domain == PF_UNSPEC)
                error(1, 0, "Pass one of -4 or -6");
        if (!daddr)
                error(1, 0, "-D <server addr> required\n");
        if (!cfg_rx && !saddr)
                error(1, 0, "-S <client addr> required\n");

        setup_sockaddr(domain, daddr, &cfg_dst_addr);
        setup_sockaddr(domain, saddr, &cfg_src_addr);

        cfg_num_pkt = parse_io(argv[optind], cfg_buf);
}

int main(int argc, char **argv)
{
        parse_opts(argc, argv);

        if (cfg_rx)
                do_test_rx((void *)&cfg_dst_addr, cfg_alen);
        else
                do_test_tx((void *)&cfg_src_addr, cfg_alen);

        return 0;
}