root/tools/testing/selftests/net/cmsg_sender.c
// SPDX-License-Identifier: GPL-2.0-or-later
#include <errno.h>
#include <error.h>
#include <netdb.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <linux/errqueue.h>
#include <linux/icmp.h>
#include <linux/icmpv6.h>
#include <linux/net_tstamp.h>
#include <linux/types.h>
#include <linux/udp.h>
#include <sys/socket.h>

#include "kselftest.h"

enum {
        ERN_SUCCESS = 0,
        /* Well defined errors, callers may depend on these */
        ERN_SEND = 1,
        /* Informational, can reorder */
        ERN_HELP,
        ERN_SEND_SHORT,
        ERN_SOCK_CREATE,
        ERN_RESOLVE,
        ERN_CMSG_WR,
        ERN_SOCKOPT,
        ERN_GETTIME,
        ERN_RECVERR,
        ERN_CMSG_RD,
        ERN_CMSG_RCV,
        ERN_SEND_MORE,
};

struct option_cmsg_u32 {
        bool ena;
        unsigned int val;
};

struct options {
        bool silent_send;
        const char *host;
        const char *service;
        unsigned int size;
        unsigned int num_pkt;
        bool msg_more;
        struct {
                unsigned int mark;
                unsigned int dontfrag;
                unsigned int tclass;
                unsigned int hlimit;
                unsigned int priority;
        } sockopt;
        struct {
                unsigned int family;
                unsigned int type;
                unsigned int proto;
        } sock;
        struct option_cmsg_u32 mark;
        struct option_cmsg_u32 priority;
        struct {
                bool ena;
                unsigned int delay;
        } txtime;
        struct {
                bool ena;
        } ts;
        struct {
                struct option_cmsg_u32 dontfrag;
                struct option_cmsg_u32 tclass;
                struct option_cmsg_u32 hlimit;
                struct option_cmsg_u32 exthdr;
        } cmsg;
} opt = {
        .size = 13,
        .num_pkt = 1,
        .sock = {
                .family = AF_UNSPEC,
                .type   = SOCK_DGRAM,
                .proto  = IPPROTO_UDP,
        },
};

static struct timespec time_start_real;
static struct timespec time_start_mono;

static void __attribute__((noreturn)) cs_usage(const char *bin)
{
        printf("Usage: %s [opts] <dst host> <dst port / service>\n", bin);
        printf("Options:\n"
               "\t\t-s      Silent send() failures\n"
               "\t\t-S      send() size\n"
               "\t\t-4/-6   Force IPv4 / IPv6 only\n"
               "\t\t-p prot Socket protocol\n"
               "\t\t        (u = UDP (default); i = ICMP; r = RAW;\n"
               "\t\t         U = UDP with MSG_MORE)\n"
               "\n"
               "\t\t-m val  Set SO_MARK with given value\n"
               "\t\t-M val  Set SO_MARK via setsockopt\n"
               "\t\t-P val  Set SO_PRIORITY via setsockopt\n"
               "\t\t-Q val  Set SO_PRIORITY via cmsg\n"
               "\t\t-d val  Set SO_TXTIME with given delay (usec)\n"
               "\t\t-t      Enable time stamp reporting\n"
               "\t\t-f val  Set don't fragment via cmsg\n"
               "\t\t-F val  Set don't fragment via setsockopt\n"
               "\t\t-c val  Set TOS/TCLASS via cmsg\n"
               "\t\t-C val  Set TOS/TCLASS via setsockopt\n"
               "\t\t-l val  Set TTL/HOPLIMIT via cmsg\n"
               "\t\t-L val  Set TTL/HOPLIMIT via setsockopt\n"
               "\t\t-H type Add an IPv6 header option\n"
               "\t\t        (h = HOP; d = DST; r = RTDST)\n"
               "\n");
        exit(ERN_HELP);
}

static void cs_parse_args(int argc, char *argv[])
{
        int o;

        while ((o = getopt(argc, argv, "46sS:p:P:m:M:n:d:tf:F:c:C:l:L:H:Q:")) != -1) {
                switch (o) {
                case 's':
                        opt.silent_send = true;
                        break;
                case 'S':
                        opt.size = atoi(optarg);
                        break;
                case '4':
                        opt.sock.family = AF_INET;
                        break;
                case '6':
                        opt.sock.family = AF_INET6;
                        break;
                case 'p':
                        if (*optarg == 'u') {
                                opt.sock.proto = IPPROTO_UDP;
                        } else if (*optarg == 'U') {
                                opt.sock.proto = IPPROTO_UDP;
                                opt.msg_more = true;
                        } else if (*optarg == 'i' || *optarg == 'I') {
                                opt.sock.proto = IPPROTO_ICMP;
                        } else if (*optarg == 'r') {
                                opt.sock.type = SOCK_RAW;
                        } else {
                                printf("Error: unknown protocol: %s\n", optarg);
                                cs_usage(argv[0]);
                        }
                        break;
                case 'P':
                        opt.sockopt.priority = atoi(optarg);
                        break;
                case 'm':
                        opt.mark.ena = true;
                        opt.mark.val = atoi(optarg);
                        break;
                case 'Q':
                        opt.priority.ena = true;
                        opt.priority.val = atoi(optarg);
                        break;
                case 'M':
                        opt.sockopt.mark = atoi(optarg);
                        break;
                case 'n':
                        opt.num_pkt = atoi(optarg);
                        break;
                case 'd':
                        opt.txtime.ena = true;
                        opt.txtime.delay = atoi(optarg);
                        break;
                case 't':
                        opt.ts.ena = true;
                        break;
                case 'f':
                        opt.cmsg.dontfrag.ena = true;
                        opt.cmsg.dontfrag.val = atoi(optarg);
                        break;
                case 'F':
                        opt.sockopt.dontfrag = atoi(optarg);
                        break;
                case 'c':
                        opt.cmsg.tclass.ena = true;
                        opt.cmsg.tclass.val = atoi(optarg);
                        break;
                case 'C':
                        opt.sockopt.tclass = atoi(optarg);
                        break;
                case 'l':
                        opt.cmsg.hlimit.ena = true;
                        opt.cmsg.hlimit.val = atoi(optarg);
                        break;
                case 'L':
                        opt.sockopt.hlimit = atoi(optarg);
                        break;
                case 'H':
                        opt.cmsg.exthdr.ena = true;
                        switch (optarg[0]) {
                        case 'h':
                                opt.cmsg.exthdr.val = IPV6_HOPOPTS;
                                break;
                        case 'd':
                                opt.cmsg.exthdr.val = IPV6_DSTOPTS;
                                break;
                        case 'r':
                                opt.cmsg.exthdr.val = IPV6_RTHDRDSTOPTS;
                                break;
                        default:
                                printf("Error: hdr type: %s\n", optarg);
                                break;
                        }
                        break;
                }
        }

        if (optind != argc - 2)
                cs_usage(argv[0]);

        opt.host = argv[optind];
        opt.service = argv[optind + 1];
}

static void memrnd(void *s, size_t n)
{
        int *dword = s;
        char *byte;

        for (; n >= 4; n -= 4)
                *dword++ = rand();
        byte = (void *)dword;
        while (n--)
                *byte++ = rand();
}

static void
ca_write_cmsg_u32(char *cbuf, size_t cbuf_sz, size_t *cmsg_len,
                  int level, int optname, struct option_cmsg_u32 *uopt)
{
        struct cmsghdr *cmsg;

        if (!uopt->ena)
                return;

        cmsg = (struct cmsghdr *)(cbuf + *cmsg_len);
        *cmsg_len += CMSG_SPACE(sizeof(__u32));
        if (cbuf_sz < *cmsg_len)
                error(ERN_CMSG_WR, EFAULT, "cmsg buffer too small");

        cmsg->cmsg_level = level;
        cmsg->cmsg_type = optname;
        cmsg->cmsg_len = CMSG_LEN(sizeof(__u32));
        *(__u32 *)CMSG_DATA(cmsg) = uopt->val;
}

static void
cs_write_cmsg(int fd, struct msghdr *msg, char *cbuf, size_t cbuf_sz)
{
        struct cmsghdr *cmsg;
        size_t cmsg_len;

        msg->msg_control = cbuf;
        cmsg_len = 0;

        ca_write_cmsg_u32(cbuf, cbuf_sz, &cmsg_len,
                          SOL_SOCKET, SO_MARK, &opt.mark);
        ca_write_cmsg_u32(cbuf, cbuf_sz, &cmsg_len,
                          SOL_SOCKET, SO_PRIORITY, &opt.priority);

        if (opt.sock.family == AF_INET) {
                ca_write_cmsg_u32(cbuf, cbuf_sz, &cmsg_len,
                                  SOL_IP, IP_TOS, &opt.cmsg.tclass);
                ca_write_cmsg_u32(cbuf, cbuf_sz, &cmsg_len,
                                  SOL_IP, IP_TTL, &opt.cmsg.hlimit);
        } else {
                ca_write_cmsg_u32(cbuf, cbuf_sz, &cmsg_len,
                                  SOL_IPV6, IPV6_DONTFRAG, &opt.cmsg.dontfrag);
                ca_write_cmsg_u32(cbuf, cbuf_sz, &cmsg_len,
                                  SOL_IPV6, IPV6_TCLASS, &opt.cmsg.tclass);
                ca_write_cmsg_u32(cbuf, cbuf_sz, &cmsg_len,
                                  SOL_IPV6, IPV6_HOPLIMIT, &opt.cmsg.hlimit);
        }

        if (opt.txtime.ena) {
                __u64 txtime;

                txtime = time_start_mono.tv_sec * (1000ULL * 1000 * 1000) +
                         time_start_mono.tv_nsec +
                         opt.txtime.delay * 1000;

                cmsg = (struct cmsghdr *)(cbuf + cmsg_len);
                cmsg_len += CMSG_SPACE(sizeof(txtime));
                if (cbuf_sz < cmsg_len)
                        error(ERN_CMSG_WR, EFAULT, "cmsg buffer too small");

                cmsg->cmsg_level = SOL_SOCKET;
                cmsg->cmsg_type = SCM_TXTIME;
                cmsg->cmsg_len = CMSG_LEN(sizeof(txtime));
                memcpy(CMSG_DATA(cmsg), &txtime, sizeof(txtime));
        }
        if (opt.ts.ena) {
                cmsg = (struct cmsghdr *)(cbuf + cmsg_len);
                cmsg_len += CMSG_SPACE(sizeof(__u32));
                if (cbuf_sz < cmsg_len)
                        error(ERN_CMSG_WR, EFAULT, "cmsg buffer too small");

                cmsg->cmsg_level = SOL_SOCKET;
                cmsg->cmsg_type = SO_TIMESTAMPING;
                cmsg->cmsg_len = CMSG_LEN(sizeof(__u32));
                *(__u32 *)CMSG_DATA(cmsg) = SOF_TIMESTAMPING_TX_SCHED |
                                            SOF_TIMESTAMPING_TX_SOFTWARE;
        }
        if (opt.cmsg.exthdr.ena) {
                cmsg = (struct cmsghdr *)(cbuf + cmsg_len);
                cmsg_len += CMSG_SPACE(8);
                if (cbuf_sz < cmsg_len)
                        error(ERN_CMSG_WR, EFAULT, "cmsg buffer too small");

                cmsg->cmsg_level = SOL_IPV6;
                cmsg->cmsg_type = opt.cmsg.exthdr.val;
                cmsg->cmsg_len = CMSG_LEN(8);
                *(__u64 *)CMSG_DATA(cmsg) = 0;
        }

        if (cmsg_len)
                msg->msg_controllen = cmsg_len;
        else
                msg->msg_control = NULL;
}

static const char *cs_ts_info2str(unsigned int info)
{
        static const char *names[] = {
                [SCM_TSTAMP_SND]        = "SND",
                [SCM_TSTAMP_SCHED]      = "SCHED",
                [SCM_TSTAMP_ACK]        = "ACK",
        };

        if (info < ARRAY_SIZE(names))
                return names[info];
        return "unknown";
}

static unsigned long
cs_read_cmsg(int fd, struct msghdr *msg, char *cbuf, size_t cbuf_sz)
{
        struct sock_extended_err *see;
        struct scm_timestamping *ts;
        unsigned long ts_seen = 0;
        struct cmsghdr *cmsg;
        int i, err;

        if (!opt.ts.ena)
                return 0;
        msg->msg_control = cbuf;
        msg->msg_controllen = cbuf_sz;

        while (true) {
                ts = NULL;
                see = NULL;
                memset(cbuf, 0, cbuf_sz);

                err = recvmsg(fd, msg, MSG_ERRQUEUE);
                if (err < 0) {
                        if (errno == EAGAIN)
                                break;
                        error(ERN_RECVERR, errno, "recvmsg ERRQ");
                }

                for (cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL;
                     cmsg = CMSG_NXTHDR(msg, cmsg)) {
                        if (cmsg->cmsg_level == SOL_SOCKET &&
                            cmsg->cmsg_type == SO_TIMESTAMPING_OLD) {
                                if (cmsg->cmsg_len < sizeof(*ts))
                                        error(ERN_CMSG_RD, EINVAL, "TS cmsg");

                                ts = (void *)CMSG_DATA(cmsg);
                        }
                        if ((cmsg->cmsg_level == SOL_IP &&
                             cmsg->cmsg_type == IP_RECVERR) ||
                            (cmsg->cmsg_level == SOL_IPV6 &&
                             cmsg->cmsg_type == IPV6_RECVERR)) {
                                if (cmsg->cmsg_len < sizeof(*see))
                                        error(ERN_CMSG_RD, EINVAL, "sock_err cmsg");

                                see = (void *)CMSG_DATA(cmsg);
                        }
                }

                if (!ts)
                        error(ERN_CMSG_RCV, ENOENT, "TS cmsg not found");
                if (!see)
                        error(ERN_CMSG_RCV, ENOENT, "sock_err cmsg not found");

                for (i = 0; i < 3; i++) {
                        unsigned long long rel_time;

                        if (!ts->ts[i].tv_sec && !ts->ts[i].tv_nsec)
                                continue;

                        rel_time = (ts->ts[i].tv_sec - time_start_real.tv_sec) *
                                (1000ULL * 1000) +
                                (ts->ts[i].tv_nsec - time_start_real.tv_nsec) /
                                1000;
                        printf(" %5s ts%d %lluus\n",
                               cs_ts_info2str(see->ee_info),
                               i, rel_time);
                        ts_seen |= 1 << see->ee_info;
                }
        }

        return ts_seen;
}

static void ca_set_sockopts(int fd)
{
        if (opt.sockopt.mark &&
            setsockopt(fd, SOL_SOCKET, SO_MARK,
                       &opt.sockopt.mark, sizeof(opt.sockopt.mark)))
                error(ERN_SOCKOPT, errno, "setsockopt SO_MARK");
        if (opt.sockopt.priority &&
            setsockopt(fd, SOL_SOCKET, SO_PRIORITY,
                       &opt.sockopt.priority, sizeof(opt.sockopt.priority)))
                error(ERN_SOCKOPT, errno, "setsockopt SO_PRIORITY");

        if (opt.sock.family == AF_INET) {
                if (opt.sockopt.tclass &&
                    setsockopt(fd, SOL_IP, IP_TOS,
                               &opt.sockopt.tclass, sizeof(opt.sockopt.tclass)))
                        error(ERN_SOCKOPT, errno, "setsockopt IP_TOS");
                if (opt.sockopt.hlimit &&
                    setsockopt(fd, SOL_IP, IP_TTL,
                               &opt.sockopt.hlimit, sizeof(opt.sockopt.hlimit)))
                        error(ERN_SOCKOPT, errno, "setsockopt IP_TTL");
        } else {
                if (opt.sockopt.dontfrag &&
                    setsockopt(fd, SOL_IPV6, IPV6_DONTFRAG,
                               &opt.sockopt.dontfrag, sizeof(opt.sockopt.dontfrag)))
                        error(ERN_SOCKOPT, errno, "setsockopt IPV6_DONTFRAG");
                if (opt.sockopt.tclass &&
                    setsockopt(fd, SOL_IPV6, IPV6_TCLASS,
                               &opt.sockopt.tclass, sizeof(opt.sockopt.tclass)))
                        error(ERN_SOCKOPT, errno, "setsockopt IPV6_TCLASS");
                if (opt.sockopt.hlimit &&
                    setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS,
                               &opt.sockopt.hlimit, sizeof(opt.sockopt.hlimit)))
                        error(ERN_SOCKOPT, errno, "setsockopt IPV6_HOPLIMIT");
        }

        if (opt.txtime.ena) {
                struct sock_txtime so_txtime = {
                        .clockid = CLOCK_MONOTONIC,
                };

                if (setsockopt(fd, SOL_SOCKET, SO_TXTIME,
                               &so_txtime, sizeof(so_txtime)))
                        error(ERN_SOCKOPT, errno, "setsockopt TXTIME");
        }
        if (opt.ts.ena) {
                __u32 val = SOF_TIMESTAMPING_SOFTWARE |
                        SOF_TIMESTAMPING_OPT_TSONLY;

                if (setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING,
                               &val, sizeof(val)))
                        error(ERN_SOCKOPT, errno, "setsockopt TIMESTAMPING");
        }
}

int main(int argc, char *argv[])
{
        struct addrinfo hints, *ai;
        struct iovec iov[1];
        unsigned char *buf;
        struct msghdr msg;
        char cbuf[1024];
        int err;
        int fd;
        int i;

        cs_parse_args(argc, argv);

        buf = malloc(opt.size);
        memrnd(buf, opt.size);

        memset(&hints, 0, sizeof(hints));
        hints.ai_family = opt.sock.family;

        ai = NULL;
        err = getaddrinfo(opt.host, opt.service, &hints, &ai);
        if (err) {
                fprintf(stderr, "Can't resolve address [%s]:%s\n",
                        opt.host, opt.service);
                err = ERN_SOCK_CREATE;
                goto err_free_buff;
        }

        if (ai->ai_family == AF_INET6 && opt.sock.proto == IPPROTO_ICMP)
                opt.sock.proto = IPPROTO_ICMPV6;

        fd = socket(ai->ai_family, opt.sock.type, opt.sock.proto);
        if (fd < 0) {
                fprintf(stderr, "Can't open socket: %s\n", strerror(errno));
                err = ERN_RESOLVE;
                goto err_free_info;
        }

        if (opt.sock.proto == IPPROTO_ICMP) {
                buf[0] = ICMP_ECHO;
                buf[1] = 0;
        } else if (opt.sock.proto == IPPROTO_ICMPV6) {
                buf[0] = ICMPV6_ECHO_REQUEST;
                buf[1] = 0;
        } else if (opt.sock.type == SOCK_RAW) {
                struct udphdr hdr = { 1, 2, htons(opt.size), 0 };
                struct sockaddr_in6 *sin6 = (void *)ai->ai_addr;

                memcpy(buf, &hdr, sizeof(hdr));
                sin6->sin6_port = htons(opt.sock.proto);
        }

        ca_set_sockopts(fd);

        if (clock_gettime(CLOCK_REALTIME, &time_start_real))
                error(ERN_GETTIME, errno, "gettime REALTIME");
        if (clock_gettime(CLOCK_MONOTONIC, &time_start_mono))
                error(ERN_GETTIME, errno, "gettime MONOTONIC");

        iov[0].iov_base = buf;
        iov[0].iov_len = opt.size;

        memset(&msg, 0, sizeof(msg));
        msg.msg_name = ai->ai_addr;
        msg.msg_namelen = ai->ai_addrlen;
        msg.msg_iov = iov;
        msg.msg_iovlen = 1;

        cs_write_cmsg(fd, &msg, cbuf, sizeof(cbuf));

        for (i = 0; i < opt.num_pkt; i++) {
                err = sendmsg(fd, &msg, opt.msg_more ? MSG_MORE : 0);
                if (err < 0) {
                        if (!opt.silent_send)
                                fprintf(stderr, "send failed: %s\n", strerror(errno));
                        err = ERN_SEND;
                        goto err_out;
                } else if (err != (int)opt.size) {
                        fprintf(stderr, "short send\n");
                        err = ERN_SEND_SHORT;
                        goto err_out;
                }
                if (opt.msg_more) {
                        err = write(fd, NULL, 0);
                        if (err < 0) {
                                fprintf(stderr, "send more: %s\n", strerror(errno));
                                err = ERN_SEND_MORE;
                                goto err_out;
                        }
                }
        }
        err = ERN_SUCCESS;

        if (opt.ts.ena) {
                unsigned long seen;
                int i;

                /* Make sure all timestamps have time to loop back */
                for (i = 0; i < 40; i++) {
                        seen = cs_read_cmsg(fd, &msg, cbuf, sizeof(cbuf));
                        if (seen & (1 << SCM_TSTAMP_SND))
                                break;
                        usleep(opt.txtime.delay / 20);
                }
        }

err_out:
        close(fd);
err_free_info:
        freeaddrinfo(ai);
err_free_buff:
        free(buf);
        return err;
}