/*      $OpenBSD: rusers_proc.c,v 1.27 2019/06/28 13:32:53 deraadt Exp $        */

/*-
 *  Copyright (c) 1993 John Brezak
 *  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. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `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 AUTHOR 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/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <paths.h>
#include <utmp.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <unistd.h>
#include <limits.h>
#include <string.h>
#include <rpc/rpc.h>
#include <rpcsvc/rusers.h>      /* New version */
#include <rpcsvc/rnusers.h>     /* Old version */

extern int utmp_fd;

typedef char ut_line_t[UT_LINESIZE+1];
typedef char ut_name_t[UT_NAMESIZE+1];
typedef char ut_host_t[UT_HOSTSIZE+1];

struct rusers_utmp utmps[MAXUSERS];
struct utmpidle *utmp_idlep[MAXUSERS];
struct utmpidle utmp_idle[MAXUSERS];
struct ru_utmp *ru_utmpp[MAXUSERS];
struct ru_utmp ru_utmp[MAXUSERS];
ut_line_t line[MAXUSERS];
ut_name_t name[MAXUSERS];
ut_host_t host[MAXUSERS];

int *rusers_num_svc(void *, struct svc_req *);
struct utmpidlearr *rusersproc_names_2_svc(void *, struct svc_req *);
struct utmpidlearr *rusersproc_allnames_2_svc(void *, struct svc_req *);
struct utmparr *rusersproc_names_1_svc(void *, struct svc_req *);
struct utmparr *rusersproc_allnames_1_svc(void *, struct svc_req *);
void rusers_service(struct svc_req *, SVCXPRT *);

extern int from_inetd;

FILE *ufp;

static long
getidle(char *tty, int len)
{
        char devname[PATH_MAX];
        struct stat st;
        long idle;
        time_t now;

        snprintf(devname, sizeof devname, "%s/%.*s", _PATH_DEV,
            len, tty);
        if (stat(devname, &st) == -1) {
#ifdef DEBUG
                printf("%s: %m\n", devname);
#endif
                return (0);
        }
        time(&now);
#ifdef DEBUG
        printf("%s: now=%lld atime=%lld\n", devname, (long long)now,
            (long long)st.st_atime);
#endif
        idle = now - st.st_atime;
        idle = (idle + 30) / 60; /* secs->mins */
        if (idle < 0)
                idle = 0;

        return (idle);
}

int *
rusers_num_svc(void *arg, struct svc_req *rqstp)
{
        static int num_users = 0;
        struct utmp usr;
        int fd;

        fd = dup(utmp_fd);
        if (fd == -1) {
                syslog(LOG_ERR, "%m");
                return (0);
        }
        lseek(fd, 0, SEEK_SET);
        ufp = fdopen(fd, "r");
        if (!ufp) {
                close(fd);
                syslog(LOG_ERR, "%m");
                return (0);
        }

        /* only entries with both name and line fields */
        while (fread(&usr, sizeof(usr), 1, ufp) == 1)
                if (*usr.ut_name && *usr.ut_line)
                        num_users++;

        fclose(ufp);
        return (&num_users);
}

static utmp_array *
do_names_3(int all)
{
        static utmp_array ut;
        struct utmp usr;
        int fd, nusers = 0;

        bzero(&ut, sizeof(ut));
        ut.utmp_array_val = &utmps[0];

        fd = dup(utmp_fd);
        if (fd == -1) {
                syslog(LOG_ERR, "%m");
                return (0);
        }
        lseek(fd, 0, SEEK_SET);
        ufp = fdopen(fd, "r");
        if (!ufp) {
                close(fd);
                syslog(LOG_ERR, "%m");
                return (NULL);
        }

        /* only entries with both name and line fields */
        while (fread(&usr, sizeof(usr), 1, ufp) == 1 &&
            nusers < MAXUSERS)
                if (*usr.ut_name && *usr.ut_line) {
                        utmps[nusers].ut_type = RUSERS_USER_PROCESS;
                        utmps[nusers].ut_time = usr.ut_time;
                        utmps[nusers].ut_idle = getidle(usr.ut_line,
                            sizeof usr.ut_line);
                        utmps[nusers].ut_line = line[nusers];
                        memset(line[nusers], 0, sizeof(line[nusers]));
                        memcpy(line[nusers], usr.ut_line, UT_LINESIZE);
                        line[nusers][UT_LINESIZE] = '\0';
                        utmps[nusers].ut_user = name[nusers];
                        memset(name[nusers], 0, sizeof(name[nusers]));
                        memcpy(name[nusers], usr.ut_name, UT_NAMESIZE);
                        name[nusers][UT_NAMESIZE] = '\0';
                        utmps[nusers].ut_host = host[nusers];
                        memset(host[nusers], 0, sizeof(host[nusers]));
                        memcpy(host[nusers], usr.ut_host, UT_HOSTSIZE);
                        host[nusers][UT_HOSTSIZE] = '\0';
                        nusers++;
                }
        ut.utmp_array_len = nusers;

        fclose(ufp);
        return (&ut);
}

utmp_array *
rusersproc_names_3_svc(void *arg, struct svc_req *rqstp)
{
        return (do_names_3(0));
}

utmp_array *
rusersproc_allnames_3_svc(void *arg, struct svc_req *rqstp)
{
        return (do_names_3(1));
}

static struct utmpidlearr *
do_names_2(int all)
{
        static struct utmpidlearr ut;
        struct utmp usr;
        int fd, nusers = 0;

        bzero(&ut, sizeof(ut));
        ut.uia_arr = utmp_idlep;
        ut.uia_cnt = 0;

        fd = dup(utmp_fd);
        if (fd == -1) {
                syslog(LOG_ERR, "%m");
                return (0);
        }
        lseek(fd, 0, SEEK_SET);
        ufp = fdopen(fd, "r");
        if (!ufp) {
                close(fd);
                syslog(LOG_ERR, "%m");
                return (NULL);
        }

        /* only entries with both name and line fields */
        while (fread(&usr, sizeof(usr), 1, ufp) == 1 &&
            nusers < MAXUSERS)
                if (*usr.ut_name && *usr.ut_line) {
                        utmp_idlep[nusers] = &utmp_idle[nusers];
                        utmp_idle[nusers].ui_utmp.ut_time = usr.ut_time;
                        utmp_idle[nusers].ui_idle = getidle(usr.ut_line,
                            sizeof usr.ut_line);
                        utmp_idle[nusers].ui_utmp.ut_line = line[nusers];
                        memset(line[nusers], 0, sizeof(line[nusers]));
                        memcpy(line[nusers], usr.ut_line, UT_LINESIZE);
                        line[nusers][UT_LINESIZE] = '\0';
                        utmp_idle[nusers].ui_utmp.ut_name = name[nusers];
                        memset(name[nusers], 0, sizeof(name[nusers]));
                        memcpy(name[nusers], usr.ut_name, UT_NAMESIZE);
                        name[nusers][UT_NAMESIZE] = '\0';
                        utmp_idle[nusers].ui_utmp.ut_host = host[nusers];
                        memset(host[nusers], 0, sizeof(host[nusers]));
                        memcpy(host[nusers], usr.ut_host, UT_HOSTSIZE);
                        host[nusers][UT_HOSTSIZE] = '\0';
                        nusers++;
                }

        ut.uia_cnt = nusers;
        fclose(ufp);
        return (&ut);
}

struct utmpidlearr *
rusersproc_names_2_svc(void *arg, struct svc_req *rqstp)
{
        return (do_names_2(0));
}

struct utmpidlearr *
rusersproc_allnames_2_svc(void *arg, struct svc_req *rqstp)
{
        return (do_names_2(1));
}

static struct utmparr *
do_names_1(int all)
{
        static struct utmparr ut;
        struct utmp usr;
        int fd, nusers = 0;

        bzero(&ut, sizeof(ut));
        ut.uta_arr = ru_utmpp;
        ut.uta_cnt = 0;

        fd = dup(utmp_fd);
        if (fd == -1) {
                syslog(LOG_ERR, "%m");
                return (0);
        }
        lseek(fd, 0, SEEK_SET);
        ufp = fdopen(fd, "r");
        if (!ufp) {
                close(fd);
                syslog(LOG_ERR, "%m");
                return (NULL);
        }

        /* only entries with both name and line fields */
        while (fread(&usr, sizeof(usr), 1, ufp) == 1 &&
            nusers < MAXUSERS)
                if (*usr.ut_name && *usr.ut_line) {
                        ru_utmpp[nusers] = &ru_utmp[nusers];
                        ru_utmp[nusers].ut_time = usr.ut_time;
                        ru_utmp[nusers].ut_line = line[nusers];
                        memcpy(line[nusers], usr.ut_line, UT_LINESIZE);
                        line[nusers][UT_LINESIZE] = '\0';
                        ru_utmp[nusers].ut_name = name[nusers];
                        memcpy(name[nusers], usr.ut_name, UT_NAMESIZE);
                        name[nusers][UT_NAMESIZE] = '\0';
                        ru_utmp[nusers].ut_host = host[nusers];
                        memcpy(host[nusers], usr.ut_host, UT_HOSTSIZE);
                        host[nusers][UT_HOSTSIZE] = '\0';
                        nusers++;
                }

        ut.uta_cnt = nusers;
        fclose(ufp);
        return (&ut);
}

struct utmparr *
rusersproc_names_1_svc(void *arg, struct svc_req *rqstp)
{
        return (do_names_1(0));
}

struct utmparr *
rusersproc_allnames_1_svc(void *arg, struct svc_req *rqstp)
{
        return (do_names_1(1));
}

void
rusers_service(struct svc_req *rqstp, SVCXPRT *transp)
{
        char *(*local)(void *, struct svc_req *);
        xdrproc_t xdr_argument, xdr_result;
        union {
                int fill;
        } argument;
        char *result;

        switch (rqstp->rq_proc) {
        case NULLPROC:
                (void)svc_sendreply(transp, xdr_void, (char *)NULL);
                goto leave;

        case RUSERSPROC_NUM:
                xdr_argument = (xdrproc_t)xdr_void;
                xdr_result = (xdrproc_t)xdr_int;
                switch (rqstp->rq_vers) {
                case RUSERSVERS_3:
                case RUSERSVERS_IDLE:
                case RUSERSVERS_ORIG:
                        local = (char *(*)(void *, struct svc_req *))
                            rusers_num_svc;
                        break;
                default:
                        svcerr_progvers(transp, RUSERSVERS_IDLE, RUSERSVERS_3);
                        goto leave;
                        /*NOTREACHED*/
                }
                break;

        case RUSERSPROC_NAMES:
                xdr_argument = (xdrproc_t)xdr_void;
                xdr_result = (xdrproc_t)xdr_utmp_array;
                switch (rqstp->rq_vers) {
                case RUSERSVERS_3:
                        local = (char *(*)(void *, struct svc_req *))
                            rusersproc_names_3_svc;
                        break;

                case RUSERSVERS_IDLE:
                        xdr_result = (xdrproc_t)xdr_utmpidlearr;
                        local = (char *(*)(void *, struct svc_req *))
                            rusersproc_names_2_svc;
                        break;

                case RUSERSVERS_ORIG:
                        xdr_result = (xdrproc_t)xdr_utmpidlearr;
                        local = (char *(*)(void *, struct svc_req *))
                            rusersproc_names_1_svc;
                        break;

                default:
                        svcerr_progvers(transp, RUSERSVERS_IDLE, RUSERSVERS_3);
                        goto leave;
                        /*NOTREACHED*/
                }
                break;

        case RUSERSPROC_ALLNAMES:
                xdr_argument = (xdrproc_t)xdr_void;
                xdr_result = (xdrproc_t)xdr_utmp_array;
                switch (rqstp->rq_vers) {
                case RUSERSVERS_3:
                        local = (char *(*)(void *, struct svc_req *))
                            rusersproc_allnames_3_svc;
                        break;

                case RUSERSVERS_IDLE:
                        xdr_result = (xdrproc_t)xdr_utmpidlearr;
                        local = (char *(*)(void *, struct svc_req *))
                            rusersproc_allnames_2_svc;
                        break;

                case RUSERSVERS_ORIG:
                        xdr_result = (xdrproc_t)xdr_utmpidlearr;
                        local = (char *(*)(void *, struct svc_req *))
                            rusersproc_allnames_1_svc;
                        break;

                default:
                        svcerr_progvers(transp, RUSERSVERS_IDLE, RUSERSVERS_3);
                        goto leave;
                        /*NOTREACHED*/
                }
                break;

        default:
                svcerr_noproc(transp);
                goto leave;
        }
        bzero((char *)&argument, sizeof(argument));
        if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
                svcerr_decode(transp);
                goto leave;
        }
        result = (*local)(&argument, rqstp);
        if (result != NULL && !svc_sendreply(transp, xdr_result, result))
                svcerr_systemerr(transp);

        if (!svc_freeargs(transp, xdr_argument, (caddr_t)&argument)) {
                syslog(LOG_ERR, "unable to free arguments");
                exit(1);
        }
leave:
        if (from_inetd)
                exit(0);
}