/*      $NetBSD: cmds.c,v 1.23 2007/02/04 21:17:01 cbiere Exp $ */

/*-
 * Copyright (c) 1985, 1993 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)cmds.c      8.2 (Berkeley) 3/26/95";
#else
__RCSID("$NetBSD: cmds.c,v 1.23 2007/02/04 21:17:01 cbiere Exp $");
#endif
#endif /* not lint */

#include "timedc.h"
#include <sys/file.h>

#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <err.h>

#define TSPTYPES
#include <protocols/timed.h>

#define SECHR   (60*60)
#define SECDAY  (24*SECHR)

int sock_raw;   /* used by measure() */
static int sock;
extern int measure_delta;

void bytenetorder(struct tsp *);
void bytehostorder(struct tsp *);
void set_tsp_name(struct tsp *, const char *);
void get_tsp_name(const struct tsp *, char *, size_t);


#define BU 2208988800UL /* seconds before UNIX epoch */

enum { CACHED, REFRESH };

static const char *
myname(int refresh)
{
        static char name[MAXHOSTNAMELEN + 1];
        static int initialized;

        if (refresh || !initialized) {
                initialized = 1;
                (void)gethostname(name, sizeof(name));
                name[sizeof(name) - 1] = '\0';
        }
        return name;
}

static in_port_t
udpservport(const char *service)
{
        const struct servent *srvp;

        srvp = getservbyname(service, "udp");
        if (srvp == NULL) {
                warnx("%s/udp: unknown service", service);
                return 0;
        }
        return srvp->s_port;
}

static const char *
getaddr(const char *name, struct sockaddr_in *addr, in_port_t port)
{
        const struct hostent *hp;

        hp = gethostbyname(name);
        if (hp == NULL) {
                warnx("Error resolving %s (%s)", name, hstrerror(h_errno));
                return NULL;
        }
        if (addr) {
                memset(addr, 0, sizeof(*addr));
                addr->sin_family = AF_INET;
                addr->sin_port = port;
                memcpy(&addr->sin_addr.s_addr, hp->h_addr, sizeof(in_addr_t));
        }
        return hp->h_name ? hp->h_name : name;
}

static const char *
tsp_type_to_string(const struct tsp *msg)
{
        unsigned i;

        i = msg->tsp_type;
        return i < TSPTYPENUMBER ? tsptype[i] : "unknown";
}

/* compute the difference between our date and another machine
 */
static int                              /* difference in days from our time */
daydiff(const char *hostname, const struct sockaddr_in *addr)
{
        struct pollfd set[1];
        int trials;

        if (connect(sock, (const struct sockaddr *)addr,
                    sizeof(*addr)) == -1) {
                warn("connect");
                return 0;
        }

        set[0].fd = sock;
        set[0].events = POLLIN;
        for (trials = 0; trials < 10; trials++) {
                ssize_t ret;
                uint32_t sec;

                /* ask for the time */
                sec = 0;
                ret = send(sock, &sec, sizeof(sec), 0);
                if (ret < (ssize_t)sizeof(sec)) {
                        if (ret < 0) 
                                warn("send(sock)");
                        else
                                warnx("send(sock): incomplete");
                        return 0;
                }

                for (;;) {
                        int i;

                        /* wait 2 seconds between 10 tries */
                        i = poll(set, 1, 2000);
                        if (i < 0) {
                                if (errno == EINTR)
                                        continue;
                                warn("poll(date read)");
                                return 0;
                        }
                        if (0 == i)
                                break;

                        ret = recv(sock, &sec, sizeof(sec), 0);
                        if (ret < (ssize_t)sizeof(sec)) {
                                if (ret < 0)
                                        warn("recv(date read)");
                                else
                                        warnx("recv(date read): incomplete");
                                return 0;
                        }

                        sec = ntohl(sec);
                        if (sec < BU) {
                                warnx("%s says it is before 1970: %lu",
                                        hostname, (unsigned long)sec);
                                return 0;
                        } else {
                                struct timeval now;

                                sec -= BU;
                                (void)gettimeofday(&now, NULL);
                                return (sec - now.tv_sec);
                        }
                }
        }

        /* if we get here, we tried too many times */
        warnx("%s will not tell us the date", hostname);
        return 0;
}


/*
 * Clockdiff computes the difference between the time of the machine on
 * which it is called and the time of the machines given as argument.
 * The time differences measured by clockdiff are obtained using a sequence
 * of ICMP TSTAMP messages which are returned to the sender by the IP module
 * in the remote machine.
 * In order to compare clocks of machines in different time zones, the time
 * is transmitted (as a 32-bit value) in milliseconds since midnight UT.
 * If a hosts uses a different time format, it should set the high order
 * bit of the 32-bit quantity it transmits.
 * However, VMS apparently transmits the time in milliseconds since midnight
 * local time (rather than GMT) without setting the high order bit.
 * Furthermore, it does not understand daylight-saving time.  This makes
 * clockdiff behaving inconsistently with hosts running VMS.
 *
 * In order to reduce the sensitivity to the variance of message transmission
 * time, clockdiff sends a sequence of messages.  Yet, measures between
 * two `distant' hosts can be affected by a small error. The error can,
 * however, be reduced by increasing the number of messages sent in each
 * measurement.
 */
void
clockdiff(int argc, char *argv[])
{
        extern int measure(u_long, u_long, const char *,
                        const struct sockaddr_in*, int);
        in_port_t port;

        if (argc < 2)  {
                printf("Usage: clockdiff host ... \n");
                return;
        }

        (void)myname(REFRESH);

        /* get the address for the date ready */
        port = udpservport("time");

        while (argc > 1) {
                struct sockaddr_in server;
                const char *hostname;
                int measure_status;
                int avg_cnt;
                long avg;

                argc--; argv++;
                if ((hostname = getaddr(*argv, &server, port)) == NULL)
                        continue;

                for (avg_cnt = 0, avg = 0; avg_cnt < 16; avg_cnt++) {
                        measure_status = measure(10000,100, *argv, &server, 1);
                        if (measure_status != GOOD)
                                break;
                        avg += measure_delta;
                }
                if (measure_status == GOOD)
                        measure_delta = avg/avg_cnt;

                switch (measure_status) {
                case HOSTDOWN:
                        printf("%s is down\n", hostname);
                        continue;
                case NONSTDTIME:
                        printf("%s transmits a non-standard time format\n",
                               hostname);
                        continue;
                case UNREACHABLE:
                        printf("%s is unreachable\n", hostname);
                        continue;
                }

                /*
                 * Try to get the date only after using ICMP timestamps to
                 * get the time.  This is because the date protocol
                 * is optional.
                 */
                if (port != 0) {
                        avg = daydiff(*argv, &server);
                        if (avg > SECDAY) {
                                printf("time on %s is %ld days ahead %s\n",
                                       hostname, avg/SECDAY, myname(CACHED));
                                continue;
                        } else if (avg < -SECDAY) {
                                printf("time on %s is %ld days behind %s\n",
                                       hostname, -avg/SECDAY, myname(CACHED));
                                continue;
                        }
                }

                if (measure_delta > 0) {
                        printf("time on %s is %d ms. ahead of time on %s\n",
                               hostname, measure_delta, myname(CACHED));
                } else if (measure_delta == 0) {
                        printf("%s and %s have the same time\n",
                               hostname, myname(CACHED));
                } else {
                        printf("time on %s is %d ms. behind time on %s\n",
                               hostname, -measure_delta, myname(CACHED));
                }
        }
        return;
}


/*
 * finds location of master timedaemon
 */
void
msite(int argc, char *argv[])
{
        struct pollfd set[1];
        in_port_t port;
        int i;

        if (argc < 1) {
                printf("Usage: msite [hostname]\n");
                return;
        }

        port = udpservport("timed");
        if (port == 0)
                return;

        (void)myname(REFRESH);
        i = 1;
        set[0].fd = sock;
        set[0].events = POLLIN;
        do {
                struct sockaddr_in dest;
                struct tsp msg;
                const char *tgtname;

                tgtname = (i >= argc) ? myname(CACHED) : argv[i];
                if (getaddr(tgtname, &dest, port) == NULL)
                        continue;

                if (connect(sock, (const struct sockaddr *)&dest,
                            sizeof(dest)) == -1) {
                        warn("connect");
                        continue;
                }

                set_tsp_name(&msg, myname(CACHED));
                msg.tsp_type = TSP_MSITE;
                msg.tsp_vers = TSPVERSION;
                bytenetorder(&msg);
                if (send(sock, &msg, sizeof(msg), 0) < 0) {
                        warn("send");
                        continue;
                }

                if (poll(set, 1, 15000)) {
                        ssize_t ret;

                        ret = recv(sock, &msg, sizeof(msg), 0);
                        if (ret < (ssize_t)sizeof(msg)) {
                                if (ret < 0)
                                        warn("recv");
                                else
                                        warnx("recv: incomplete");
                                continue;
                        }
                        bytehostorder(&msg);
                        if (msg.tsp_type == TSP_ACK) {
                                char name[MAXHOSTNAMELEN];

                                get_tsp_name(&msg, name, sizeof(name));
                                printf("master timedaemon at %s is %s\n",
                                       tgtname, name);
                        } else {
                                printf("received wrong ack: %s\n",
                                       tsp_type_to_string(&msg));
                        }
                } else {
                        printf("communication error with %s\n", tgtname);
                }
        } while (++i < argc);
}

/*
 * quits timedc
 */
void
quit(int argc, char *argv[])
{
        (void) argc;
        (void) argv;
        exit(EXIT_SUCCESS);
}


/*
 * Causes the election timer to expire on the selected hosts
 * It sends just one udp message per machine, relying on
 * reliability of communication channel.
 */
void
testing(int argc, char *argv[])
{
        in_port_t port;

        if (argc < 2)  {
                printf("Usage: election host1 [host2 ...]\n");
                return;
        }

        port = udpservport("timed");
        if (port == 0)
                return;

        while (argc > 1) {
                struct sockaddr_in addr;
                struct tsp msg;

                argc--; argv++;
                if (getaddr(*argv, &addr, port) == NULL)
                        continue;

                msg.tsp_type = TSP_TEST;
                msg.tsp_vers = TSPVERSION;
                set_tsp_name(&msg, myname(CACHED));
                bytenetorder(&msg);
                if (sendto(sock, &msg, sizeof(msg), 0,
                           (const struct sockaddr*)&addr, sizeof(addr)) < 0) {
                        warn("send");
                }
        }
}


/*
 * Enables or disables tracing on local timedaemon
 */
void
tracing(int argc, char *argv[])
{
        struct pollfd set[1];
        struct sockaddr_in dest;
        in_port_t port;
        struct tsp msg;
        int onflag;

        if (argc != 2) {
                printf("Usage: tracing { on | off }\n");
                return;
        }

        port = udpservport("timed");
        if (port == 0)
                return;
        if (getaddr(myname(REFRESH), &dest, port) == NULL)
                return;
        if (connect(sock, (const struct sockaddr *)&dest,
                    sizeof(dest)) == -1) {
                warn("connect");
                return;
        }

        if (strcmp(argv[1], "on") == 0) {
                msg.tsp_type = TSP_TRACEON;
                onflag = ON;
        } else {
                msg.tsp_type = TSP_TRACEOFF;
                onflag = OFF;
        }

        set_tsp_name(&msg, myname(CACHED));
        msg.tsp_vers = TSPVERSION;
        bytenetorder(&msg);
        if (send(sock, &msg, sizeof(msg), 0) < 0) {
                warn("send");
                return;
        }

        set[0].fd = sock;
        set[0].events = POLLIN;
        if (poll(set, 1, 5000)) {
                ssize_t ret;

                ret = recv(sock, &msg, sizeof(msg), 0);
                if (ret < (ssize_t)sizeof(msg)) {
                        if (ret < 0)
                                warn("recv");
                        else
                                warnx("recv: incomplete");
                        return;
                }
                bytehostorder(&msg);
                if (msg.tsp_type == TSP_ACK)
                        printf("timed tracing %s\n",
                                onflag ? "enabled" : "disabled");
                else
                        printf("wrong ack received: %s\n",
                                tsp_type_to_string(&msg));
        } else
                printf("communication error\n");
}

int
priv_resources(void)
{
        if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
                warn("Cannot open UDP socket");
                return -1;
        }

        if ((sock_raw = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) == -1) {
                warn("Cannot open raw socket");
                (void)close(sock);
                return -1;
        }
        return 1;
}