/*      $OpenBSD: ypserv.c,v 1.45 2023/03/08 04:43:15 guenther Exp $ */

/*
 * Copyright (c) 1994 Mats O Jansson <moj@stacken.kth.se>
 * 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.
 *
 * 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/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <rpcsvc/yp.h>
#include "ypv1.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <signal.h>
#include <errno.h>
#include <util.h>
#include <unistd.h>
#include <fcntl.h>
#include <rpc/pmap_clnt.h>
#include <ndbm.h>
#include <syslog.h>
#include "acl.h"
#include "yplog.h"
#include "ypdef.h"
#include "ypserv.h"
#include <sys/wait.h>

void ypdb_init(void);

#ifdef DEBUG
#define RPC_SVC_FG
#endif

#define _RPCSVC_CLOSEDOWN 120
static int _rpcpmstart;         /* Started by a port monitor ? */
static int _rpcfdtype;          /* Whether Stream or Datagram ? */
static int _rpcsvcdirty;        /* Still serving ? */

int     usedns = FALSE;
char   *aclfile = NULL;

void    sig_child(int);
void    sig_hup(int);
volatile sig_atomic_t wantsighup;

static void
_msgout(char *msg)
{
#ifdef RPC_SVC_FG
        if (_rpcpmstart)
                syslog(LOG_ERR, "%s", msg);
        else
                (void) fprintf(stderr, "%s\n", msg);
#else
        syslog(LOG_ERR, "%s", msg);
#endif
}

static void
closedown(int sig)
{
        int save_errno = errno;

        if (_rpcsvcdirty == 0) {
                int i, openfd;

                if (_rpcfdtype == SOCK_DGRAM)
                        exit(0);
                for (i = 0, openfd = 0; i < svc_max_pollfd && openfd < 2; i++)
                        if (svc_pollfd[i].fd != -1)
                                openfd++;
                if (openfd <= (_rpcpmstart ? 0 : 1))
                        _exit(0);
        }
        (void) alarm(_RPCSVC_CLOSEDOWN);
        errno = save_errno;
}

static void
ypprog_1(struct svc_req *rqstp, SVCXPRT *transp)
{
        union {
                domainname ypoldproc_domain_1_arg;
                domainname ypoldproc_domain_nonack_1_arg;
                yprequest ypoldproc_match_1_arg;
                yprequest ypoldproc_first_1_arg;
                yprequest ypoldproc_next_1_arg;
                yprequest ypoldproc_poll_1_arg;
                yprequest ypoldproc_push_1_arg;
                yprequest ypoldproc_pull_1_arg;
                yprequest ypoldproc_get_1_arg;
        } argument;
        char *result;
        xdrproc_t xdr_argument, xdr_result;
        char *(*local)(char *, struct svc_req *);

        _rpcsvcdirty = 1;
        switch (rqstp->rq_proc) {
        case YPOLDPROC_NULL:
                xdr_argument = (xdrproc_t) xdr_void;
                xdr_result = (xdrproc_t) xdr_void;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_null_1_svc;
                break;

        case YPOLDPROC_DOMAIN:
                xdr_argument = (xdrproc_t) xdr_domainname;
                xdr_result = (xdrproc_t) xdr_bool;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_domain_1_svc;
                break;

        case YPOLDPROC_DOMAIN_NONACK:
                xdr_argument = (xdrproc_t) xdr_domainname;
                xdr_result = (xdrproc_t) xdr_bool;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_domain_nonack_1_svc;
                break;

        case YPOLDPROC_MATCH:
                xdr_argument = (xdrproc_t) xdr_yprequest;
                xdr_result = (xdrproc_t) xdr_ypresponse;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_match_1_svc;
                break;

        case YPOLDPROC_FIRST:
                xdr_argument = (xdrproc_t) xdr_yprequest;
                xdr_result = (xdrproc_t) xdr_ypresponse;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_first_1_svc;
                break;

        case YPOLDPROC_NEXT:
                xdr_argument = (xdrproc_t) xdr_yprequest;
                xdr_result = (xdrproc_t) xdr_ypresponse;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_next_1_svc;
                break;

        case YPOLDPROC_POLL:
                xdr_argument = (xdrproc_t) xdr_yprequest;
                xdr_result = (xdrproc_t) xdr_ypresponse;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_poll_1_svc;
                break;

        case YPOLDPROC_PUSH:
                xdr_argument = (xdrproc_t) xdr_yprequest;
                xdr_result = (xdrproc_t) xdr_void;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_push_1_svc;
                break;

        case YPOLDPROC_PULL:
                xdr_argument = (xdrproc_t) xdr_yprequest;
                xdr_result = (xdrproc_t) xdr_void;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_pull_1_svc;
                break;

        case YPOLDPROC_GET:
                xdr_argument = (xdrproc_t) xdr_yprequest;
                xdr_result = (xdrproc_t) xdr_void;
                local = (char *(*)(char *, struct svc_req *)) ypoldproc_get_1_svc;
                break;

        default:
                svcerr_noproc(transp);
                _rpcsvcdirty = 0;
                return;
        }
        (void) memset(&argument, 0, sizeof(argument));
        if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
                svcerr_decode(transp);
                _rpcsvcdirty = 0;
                return;
        }
        result = (*local)((char *)&argument, rqstp);
        if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
                svcerr_systemerr(transp);
        }
        if (!svc_freeargs(transp, xdr_argument, (caddr_t)&argument)) {
                _msgout("unable to free arguments");
                exit(1);
        }
        _rpcsvcdirty = 0;
}

static void
ypprog_2(struct svc_req *rqstp, SVCXPRT *transp)
{
        union {
                domainname ypproc_domain_2_arg;
                domainname ypproc_domain_nonack_2_arg;
                ypreq_key ypproc_match_2_arg;
                ypreq_nokey ypproc_first_2_arg;
                ypreq_key ypproc_next_2_arg;
                ypreq_xfr ypproc_xfr_2_arg;
                ypreq_nokey ypproc_all_2_arg;
                ypreq_nokey ypproc_master_2_arg;
                ypreq_nokey ypproc_order_2_arg;
                domainname ypproc_maplist_2_arg;
        } argument;
        char *result;
        xdrproc_t xdr_argument, xdr_result;
        char *(*local)(char *, struct svc_req *);

        _rpcsvcdirty = 1;
        switch (rqstp->rq_proc) {
        case YPPROC_NULL:
                xdr_argument = (xdrproc_t) xdr_void;
                xdr_result = (xdrproc_t) xdr_void;
                local = (char *(*)(char *, struct svc_req *)) ypproc_null_2_svc;
                break;

        case YPPROC_DOMAIN:
                xdr_argument = (xdrproc_t) xdr_domainname;
                xdr_result = (xdrproc_t) xdr_bool;
                local = (char *(*)(char *, struct svc_req *)) ypproc_domain_2_svc;
                break;

        case YPPROC_DOMAIN_NONACK:
                xdr_argument = (xdrproc_t) xdr_domainname;
                xdr_result = (xdrproc_t) xdr_bool;
                local = (char *(*)(char *, struct svc_req *)) ypproc_domain_nonack_2_svc;
                break;

        case YPPROC_MATCH:
                xdr_argument = (xdrproc_t) xdr_ypreq_key;
                xdr_result = (xdrproc_t) xdr_ypresp_val;
                local = (char *(*)(char *, struct svc_req *)) ypproc_match_2_svc;
                break;

        case YPPROC_FIRST:
                xdr_argument = (xdrproc_t) xdr_ypreq_nokey;
                xdr_result = (xdrproc_t) xdr_ypresp_key_val;
                local = (char *(*)(char *, struct svc_req *)) ypproc_first_2_svc;
                break;

        case YPPROC_NEXT:
                xdr_argument = (xdrproc_t) xdr_ypreq_key;
                xdr_result = (xdrproc_t) xdr_ypresp_key_val;
                local = (char *(*)(char *, struct svc_req *)) ypproc_next_2_svc;
                break;

        case YPPROC_XFR:
                xdr_argument = (xdrproc_t) xdr_ypreq_xfr;
                xdr_result = (xdrproc_t) xdr_ypresp_xfr;
                local = (char *(*)(char *, struct svc_req *)) ypproc_xfr_2_svc;
                break;

        case YPPROC_CLEAR:
                xdr_argument = (xdrproc_t) xdr_void;
                xdr_result = (xdrproc_t) xdr_void;
                local = (char *(*)(char *, struct svc_req *)) ypproc_clear_2_svc;
                break;

        case YPPROC_ALL:
                xdr_argument = (xdrproc_t) xdr_ypreq_nokey;
                xdr_result = (xdrproc_t) xdr_ypresp_all;
                local = (char *(*)(char *, struct svc_req *)) ypproc_all_2_svc;
                break;

        case YPPROC_MASTER:
                xdr_argument = (xdrproc_t) xdr_ypreq_nokey;
                xdr_result = (xdrproc_t) xdr_ypresp_master;
                local = (char *(*)(char *, struct svc_req *)) ypproc_master_2_svc;
                break;

        case YPPROC_ORDER:
                xdr_argument = (xdrproc_t) xdr_ypreq_nokey;
                xdr_result = (xdrproc_t) xdr_ypresp_order;
                local = (char *(*)(char *, struct svc_req *)) ypproc_order_2_svc;
                break;

        case YPPROC_MAPLIST:
                xdr_argument = (xdrproc_t) xdr_domainname;
                xdr_result = (xdrproc_t) xdr_ypresp_maplist;
                local = (char *(*)(char *, struct svc_req *)) ypproc_maplist_2_svc;
                break;

        default:
                svcerr_noproc(transp);
                _rpcsvcdirty = 0;
                return;
        }
        (void) memset(&argument, 0, sizeof(argument));
        if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
                svcerr_decode(transp);
                _rpcsvcdirty = 0;
                return;
        }
        result = (*local)((char *)&argument, rqstp);
        if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
                svcerr_systemerr(transp);
        }
        if (!svc_freeargs(transp, xdr_argument, (caddr_t)&argument)) {
                _msgout("unable to free arguments");
                exit(1);
        }
        _rpcsvcdirty = 0;
}

static void
hup(void)
{
        /* Handle the log. */
        ypcloselog();
        ypopenlog();

        acl_reset();
        if (aclfile != NULL) {
                yplog("sig_hup: reread %s", aclfile);
                (void)acl_init(aclfile);
        } else {
                yplog("sig_hup: reread %s", YP_SECURENET_FILE);
                (void)acl_securenet(YP_SECURENET_FILE);
        }

        ypdb_close_all();
}

static void
my_svc_run(void)
{
        struct pollfd *pfd = NULL, *newp;
        int nready, saved_max_pollfd = 0;

        for (;;) {
                if (wantsighup) {
                        wantsighup = 0;
                        hup();
                }
                if (svc_max_pollfd > saved_max_pollfd) {
                        newp = reallocarray(pfd, svc_max_pollfd, sizeof(*pfd));
                        if (newp == NULL) {
                                free(pfd);
                                perror("svc_run: - realloc failed");
                                return;
                        }
                        pfd = newp;
                        saved_max_pollfd = svc_max_pollfd;
                }
                memcpy(pfd, svc_pollfd, sizeof(*pfd) * svc_max_pollfd);

                nready = poll(pfd, svc_max_pollfd, INFTIM);
                switch (nready) {
                case -1:
                        if (errno == EINTR)
                                continue;
                        perror("svc_run: - poll failed");
                        free(pfd);
                        return;
                case 0:
                        continue;
                default:
                        svc_getreq_poll(pfd, nready);
                }
        }
}

static void
usage(void)
{
        (void)fprintf(stderr, "usage: ypserv [-1dx] [-a aclfile]\n");
        exit(1);
}

int
main(int argc, char *argv[])
{
        int xflag = 0, allowv1 = 0, ch, sock, proto;
        struct sockaddr_in saddr;
        socklen_t asize = sizeof(saddr);
        extern char *optarg;
        SVCXPRT *transp = NULL;

        while ((ch = getopt(argc, argv, "1a:dx")) != -1)
                switch (ch) {
                case '1':
                        allowv1 = TRUE;
                        break;
                case 'a':
                        aclfile = optarg;
                        break;
                case 'd':
                        usedns = TRUE;
                        break;
                case 'x':
                        xflag = TRUE;
                        break;
                default:
                        usage();
                        break;
                }

        if (geteuid() != 0) {
                (void)fprintf(stderr, "ypserv: must be root to run.\n");
                exit(1);
        }

        if (aclfile != NULL)
                (void)acl_init(aclfile);
        else
                (void)acl_securenet(YP_SECURENET_FILE);

        if (xflag)
                exit(1);

        if (getsockname(0, (struct sockaddr *)&saddr, &asize) == 0) {
                socklen_t ssize = sizeof(int);

                if (saddr.sin_family != AF_INET)
                        exit(1);
                if (getsockopt(0, SOL_SOCKET, SO_TYPE,
                    &_rpcfdtype, &ssize) == -1)
                        exit(1);
                sock = 0;
                _rpcpmstart = 1;
                proto = 0;
                openlog("ypserv", LOG_PID, LOG_DAEMON);
        } else {
#ifndef RPC_SVC_FG
                int i;
                pid_t pid;

                pid = fork();
                if (pid < 0) {
                        perror("cannot fork");
                        exit(1);
                }
                if (pid)
                        exit(0);
                closefrom(0);
                i = open("/dev/console", O_RDWR);
                (void) dup2(i, 1);
                (void) dup2(i, 2);
                i = open("/dev/tty", O_RDWR);
                if (i >= 0) {
                        (void) ioctl(i, TIOCNOTTY, NULL);
                        (void) close(i);
                }
                openlog("ypserv", LOG_PID, LOG_DAEMON);
#endif
                sock = RPC_ANYSOCK;
                (void) pmap_unset(YPPROG, YPVERS);
                (void) pmap_unset(YPPROG, YPOLDVERS);
        }

        ypopenlog();    /* open log file */
        ypdb_init();    /* init db stuff */

        chdir("/");

        (void)signal(SIGCHLD, sig_child);
        (void)signal(SIGHUP, sig_hup);

        if (_rpcfdtype == 0 || _rpcfdtype == SOCK_DGRAM) {
                transp = svcudp_create(sock);
                if (transp == NULL) {
                        _msgout("cannot create udp service.");
                        exit(1);
                }
                if (transp->xp_port >= IPPORT_RESERVED) {
                        _msgout("cannot allocate udp privileged port.");
                        exit(1);
                }
                if (!_rpcpmstart)
                        proto = IPPROTO_UDP;
                if (allowv1) {
                        if (!svc_register(transp, YPPROG, YPOLDVERS, ypprog_1, proto)) {
                                _msgout("unable to register (YPPROG, YPOLDVERS, udp).");
                                exit(1);
                        }
                }
                if (!svc_register(transp, YPPROG, YPVERS, ypprog_2, proto)) {
                        _msgout("unable to register (YPPROG, YPVERS, udp).");
                        exit(1);
                }
        }

        if (_rpcfdtype == 0 || _rpcfdtype == SOCK_STREAM) {
                if (_rpcpmstart)
                        transp = svcfd_create(sock, 0, 0);
                else
                        transp = svctcp_create(sock, 0, 0);
                if (transp == NULL) {
                        _msgout("cannot create tcp service.");
                        exit(1);
                }
                if (transp->xp_port >= IPPORT_RESERVED) {
                        _msgout("cannot allocate tcp privileged port.");
                        exit(1);
                }
                if (!_rpcpmstart)
                        proto = IPPROTO_TCP;
                if (allowv1) {
                        if (!svc_register(transp, YPPROG, YPOLDVERS, ypprog_1, proto)) {
                                _msgout("unable to register (YPPROG, YPOLDVERS, tcp).");
                                exit(1);
                        }
                }
                if (!svc_register(transp, YPPROG, YPVERS, ypprog_2, proto)) {
                        _msgout("unable to register (YPPROG, YPVERS, tcp).");
                        exit(1);
                }
        }

        if (transp == NULL) {
                _msgout("could not create a handle");
                exit(1);
        }
        if (_rpcpmstart) {
                (void) signal(SIGALRM, closedown);
                (void) alarm(_RPCSVC_CLOSEDOWN);
        }
        my_svc_run();
        _msgout("svc_run returned");
        exit(1);
        /* NOTREACHED */
}

void
sig_child(int signo)
{
        int save_errno = errno;

        while (wait3(NULL, WNOHANG, NULL) > 0)
                ;
        errno = save_errno;
}

void
sig_hup(int signo)
{
        wantsighup = 1;
}