/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1995
 *      Bill Paul <wpaul@ctr.columbia.edu>.  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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul 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 Bill Paul 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>
/*
 * ypserv startup function.
 * We need out own main() since we have to do some additional work
 * that rpcgen won't do for us. Most of this file was generated using
 * rpcgen.new, and later modified.
 */

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include "yp.h"
#include <err.h>
#include <errno.h>
#include <memory.h>
#include <stdio.h>
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h> /* getenv, exit */
#include <string.h> /* strcmp */
#include <syslog.h>
#include <unistd.h>
#ifdef __cplusplus
#include <sysent.h> /* getdtablesize, open */
#endif /* __cplusplus */
#include <netinet/in.h>
#include <netdb.h>
#include "yp_extern.h"
#include <netconfig.h>
#include <rpc/rpc.h>
#include <rpc/rpc_com.h>

#ifndef SIG_PF
#define SIG_PF void(*)(int)
#endif

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

/* States a server can be in wrt request */
#define _IDLE 0
#define _SERVED 1
#define _SERVING 2

extern void ypprog_1(struct svc_req *, SVCXPRT *);
extern void ypprog_2(struct svc_req *, SVCXPRT *);
extern int _rpc_dtablesize(void);
extern int _rpcsvcstate;         /* Set when a request is serviced */
char *progname = "ypserv";
char *yp_dir = _PATH_YP;
int debug;
int do_dns = 0;
int resfd;

struct socklistent {
        int                             sle_sock;
        struct sockaddr_storage         sle_ss;
        SLIST_ENTRY(socklistent)        sle_next;
};
static SLIST_HEAD(, socklistent) sle_head =
        SLIST_HEAD_INITIALIZER(sle_head);

struct bindaddrlistent {
        const char                      *ble_hostname;
        SLIST_ENTRY(bindaddrlistent)    ble_next;
};
static SLIST_HEAD(, bindaddrlistent) ble_head =
        SLIST_HEAD_INITIALIZER(ble_head);

static char *servname = "0";

static
void _msgout(char* msg, ...)
{
        va_list ap;

        va_start(ap, msg);
        if (debug) {
                if (_rpcpmstart)
                        vsyslog(LOG_ERR, msg, ap);
                else
                        vwarnx(msg, ap);
        } else
                vsyslog(LOG_ERR, msg, ap);
        va_end(ap);
}

pid_t   yp_pid;

static void
yp_svc_run(void)
{
#ifdef FD_SETSIZE
        fd_set readfds;
#else
        int readfds;
#endif /* def FD_SETSIZE */
        int fd_setsize = _rpc_dtablesize();
        struct timeval timeout;

        /* Establish the identity of the parent ypserv process. */
        yp_pid = getpid();

        for (;;) {
#ifdef FD_SETSIZE
                readfds = svc_fdset;
#else
                readfds = svc_fds;
#endif /* def FD_SETSIZE */

                FD_SET(resfd, &readfds);

                timeout.tv_sec = RESOLVER_TIMEOUT;
                timeout.tv_usec = 0;
                switch (select(fd_setsize, &readfds, NULL, NULL,
                               &timeout)) {
                case -1:
                        if (errno == EINTR) {
                                continue;
                        }
                        warn("svc_run: - select failed");
                        return;
                case 0:
                        if (getpid() == yp_pid)
                                yp_prune_dnsq();
                        break;
                default:
                        if (getpid() == yp_pid) {
                                if (FD_ISSET(resfd, &readfds)) {
                                        yp_run_dnsq();
                                        FD_CLR(resfd, &readfds);
                                }
                                svc_getreqset(&readfds);
                        }
                }
                if (yp_pid != getpid())
                        _exit(0);
        }
}

static void
unregister(void)
{
        (void)svc_unreg(YPPROG, YPVERS);
        (void)svc_unreg(YPPROG, YPOLDVERS);
}

static void
reaper(int sig)
{
        int                     status;
        int                     saved_errno;

        saved_errno = errno;

        if (sig == SIGHUP) {
                load_securenets();
#ifdef DB_CACHE
                yp_flush_all();
#endif
                errno = saved_errno;
                return;
        }

        if (sig == SIGCHLD) {
                while (wait3(&status, WNOHANG, NULL) > 0)
                        children--;
        } else {
                unregister();
                exit(0);
        }
        errno = saved_errno;
}

static void
usage(void)
{
        fprintf(stderr, "usage: ypserv [-h addr] [-d] [-n] [-p path] [-P port]\n");
        exit(1);
}

static void
closedown(int sig)
{
        if (_rpcsvcstate == _IDLE) {
                extern fd_set svc_fdset;
                static int size;
                int i, openfd;

                if (_rpcfdtype == SOCK_DGRAM) {
                        unregister();
                        exit(0);
                }
                if (size == 0) {
                        size = getdtablesize();
                }
                for (i = 0, openfd = 0; i < size && openfd < 2; i++)
                        if (FD_ISSET(i, &svc_fdset))
                                openfd++;
                if (openfd <= 1) {
                        unregister();
                        exit(0);
                }
        }
        if (_rpcsvcstate == _SERVED)
                _rpcsvcstate = _IDLE;

        (void) signal(SIGALRM, (SIG_PF) closedown);
        (void) alarm(_RPCSVC_CLOSEDOWN/2);
}

static int
create_service(const int sock, const struct netconfig *nconf,
        const struct __rpc_sockinfo *si)
{
        int error;

        SVCXPRT *transp;
        struct addrinfo hints, *res, *res0;
        struct socklistent *slep;
        struct bindaddrlistent *blep;
        struct netbuf svcaddr;

        SLIST_INIT(&sle_head);
        memset(&hints, 0, sizeof(hints));
        memset(&svcaddr, 0, sizeof(svcaddr));

        hints.ai_family = si->si_af;
        hints.ai_socktype = si->si_socktype;
        hints.ai_protocol = si->si_proto;

        /*
         * Build socketlist from bindaddrlist.
         */
        if (sock == RPC_ANYFD) {
                SLIST_FOREACH(blep, &ble_head, ble_next) {
                        if (blep->ble_hostname == NULL)
                                hints.ai_flags = AI_PASSIVE;
                        else
                                hints.ai_flags = 0;
                        error = getaddrinfo(blep->ble_hostname, servname,
                                    &hints, &res0);
                        if (error) {
                                _msgout("getaddrinfo(): %s",
                                    gai_strerror(error));
                                return -1;
                        }
                        for (res = res0; res; res = res->ai_next) {
                                int s;

                                s = __rpc_nconf2fd(nconf);
                                if (s < 0) {
                                        if (errno == EAFNOSUPPORT)
                                                _msgout("unsupported"
                                                    " transport: %s",
                                                    nconf->nc_netid);
                                        else
                                                _msgout("cannot create"
                                                    " %s socket: %s",
                                                    nconf->nc_netid,
                                                    strerror(errno));
                                        freeaddrinfo(res0);
                                        return -1;
                                }
                                if (bindresvport_sa(s, res->ai_addr) == -1) {
                                        if ((errno != EPERM) ||
                                            (bind(s, res->ai_addr,
                                            res->ai_addrlen) == -1)) {
                                                _msgout("cannot bind "
                                                    "%s socket: %s",
                                                    nconf->nc_netid,
                                                strerror(errno));
                                                freeaddrinfo(res0);
                                                close(sock);
                                                return -1;
                                        }
                                }
                                if (nconf->nc_semantics != NC_TPI_CLTS)
                                        listen(s, SOMAXCONN);

                                slep = malloc(sizeof(*slep));
                                if (slep == NULL) {
                                        _msgout("malloc failed: %s",
                                            strerror(errno));
                                        freeaddrinfo(res0);
                                        close(s);
                                        return -1;
                                }
                                memset(slep, 0, sizeof(*slep));
                                memcpy(&slep->sle_ss, res->ai_addr,
                                    res->ai_addrlen);
                                slep->sle_sock = s;
                                SLIST_INSERT_HEAD(&sle_head, slep, sle_next);

                                /*
                                 * If servname == "0", redefine it by using
                                 * the bound socket.
                                 */
                                if (strncmp("0", servname, 1) == 0) {
                                        struct sockaddr *sap;
                                        socklen_t slen;
                                        char *sname;

                                        sname = malloc(NI_MAXSERV);
                                        if (sname == NULL) {
                                                _msgout("malloc(): %s",
                                                    strerror(errno));
                                                freeaddrinfo(res0);
                                                close(s);
                                                return -1;
                                        }
                                        memset(sname, 0, NI_MAXSERV);

                                        sap = (struct sockaddr *)&slep->sle_ss;
                                        slen = sizeof(*sap);
                                        error = getsockname(s, sap, &slen);
                                        if (error) {
                                                _msgout("getsockname(): %s",
                                                    strerror(errno));
                                                freeaddrinfo(res0);
                                                close(s);
                                                free(sname);
                                                return -1;
                                        }
                                        error = getnameinfo(sap, slen,
                                            NULL, 0,
                                            sname, NI_MAXSERV,
                                            NI_NUMERICHOST | NI_NUMERICSERV);
                                        if (error) {
                                                _msgout("getnameinfo(): %s",
                                                    strerror(errno));
                                                freeaddrinfo(res0);
                                                close(s);
                                                free(sname);
                                                return -1;
                                        }
                                        servname = sname;
                                }
                        }
                        freeaddrinfo(res0);
                }
        } else {
                slep = malloc(sizeof(*slep));
                if (slep == NULL) {
                        _msgout("malloc failed: %s", strerror(errno));
                        return -1;
                }
                memset(slep, 0, sizeof(*slep));
                slep->sle_sock = sock;
                SLIST_INSERT_HEAD(&sle_head, slep, sle_next);
        }

        /*
         * Traverse socketlist and create rpc service handles for each socket.
         */
        SLIST_FOREACH(slep, &sle_head, sle_next) {
                if (nconf->nc_semantics == NC_TPI_CLTS)
                        transp = svc_dg_create(slep->sle_sock, 0, 0);
                else
                        transp = svc_vc_create(slep->sle_sock, RPC_MAXDATASIZE,
                            RPC_MAXDATASIZE);
                if (transp == NULL) {
                        _msgout("unable to create service: %s",
                            nconf->nc_netid);
                        continue;
                }
                if (!svc_reg(transp, YPPROG, YPOLDVERS, ypprog_1, NULL)) {
                        svc_destroy(transp);
                        close(slep->sle_sock);
                        _msgout("unable to register (YPPROG, YPOLDVERS, %s):"
                            " %s", nconf->nc_netid, strerror(errno));
                        continue;
                }
                if (!svc_reg(transp, YPPROG, YPVERS, ypprog_2, NULL)) {
                        svc_destroy(transp);
                        close(slep->sle_sock);
                        _msgout("unable to register (YPPROG, YPVERS, %s): %s",
                            nconf->nc_netid, strerror(errno));
                        continue;
                }
        }
        while(!(SLIST_EMPTY(&sle_head)))
                SLIST_REMOVE_HEAD(&sle_head, sle_next);

        /*
         * Register RPC service to rpcbind by using AI_PASSIVE address.
         */
        hints.ai_flags = AI_PASSIVE;
        error = getaddrinfo(NULL, servname, &hints, &res0);
        if (error) {
                _msgout("getaddrinfo(): %s", gai_strerror(error));
                return -1;
        }
        svcaddr.buf = res0->ai_addr;
        svcaddr.len = res0->ai_addrlen;

        if (si->si_af == AF_INET) {
                /* XXX: ignore error intentionally */
                rpcb_set(YPPROG, YPOLDVERS, nconf, &svcaddr);
        }
        /* XXX: ignore error intentionally */
        rpcb_set(YPPROG, YPVERS, nconf, &svcaddr);
        freeaddrinfo(res0);
        return 0;
}

int
main(int argc, char *argv[])
{
        int ch;
        int error;
        int ntrans;
        
        void *nc_handle;
        struct netconfig *nconf;
        struct __rpc_sockinfo si;
        struct bindaddrlistent *blep;

        memset(&si, 0, sizeof(si));
        SLIST_INIT(&ble_head);

        while ((ch = getopt(argc, argv, "dh:np:P:")) != -1) {
                switch (ch) {
                case 'd':
                        debug = ypdb_debug = 1;
                        break;
                case 'h':
                        blep = malloc(sizeof(*blep));
                        if (blep == NULL)
                                err(1, "malloc() failed: -h %s", optarg);
                        blep->ble_hostname = optarg;
                        SLIST_INSERT_HEAD(&ble_head, blep, ble_next);
                        break;
                case 'n':
                        do_dns = 1;
                        break;
                case 'p':
                        yp_dir = optarg;
                        break;
                case 'P':
                        servname = optarg;
                        break;
                default:
                        usage();
                }
        }
        /*
         * Add "anyaddr" entry if no -h is specified.
         */
        if (SLIST_EMPTY(&ble_head)) {
                blep = malloc(sizeof(*blep));
                if (blep == NULL)
                        err(1, "malloc() failed");
                memset(blep, 0, sizeof(*blep));
                SLIST_INSERT_HEAD(&ble_head, blep, ble_next);
        }

        load_securenets();
        yp_init_resolver();
#ifdef DB_CACHE
        yp_init_dbs();
#endif
        nc_handle = setnetconfig();
        if (nc_handle == NULL)
                err(1, "cannot read %s", NETCONFIG);
        if (__rpc_fd2sockinfo(0, &si) != 0) {
                /* invoked from inetd */
                _rpcpmstart = 1;
                _rpcfdtype = si.si_socktype;
                _rpcaf = si.si_af;
                _rpcfd = 0;
                openlog("ypserv", LOG_PID, LOG_DAEMON);
        } else {
                /* standalone mode */
                if (!debug) {
                        if (daemon(0,0)) {
                                err(1,"cannot fork");
                        }
                        openlog("ypserv", LOG_PID, LOG_DAEMON);
                }
                _rpcpmstart = 0;
                _rpcaf = AF_INET;
                _rpcfd = RPC_ANYFD;
                unregister();
        }

        if (madvise(NULL, 0, MADV_PROTECT) != 0)
                _msgout("madvise(): %s", strerror(errno));

        /*
         * Create RPC service for each transport.
         */
        ntrans = 0;
        while((nconf = getnetconfig(nc_handle))) {
                if ((nconf->nc_flag & NC_VISIBLE)) {
                        if (__rpc_nconf2sockinfo(nconf, &si) == 0) {
                                _msgout("cannot get information for %s.  "
                                    "Ignored.", nconf->nc_netid);
                                continue;
                        }
                        if (_rpcpmstart) {
                                if (si.si_socktype != _rpcfdtype ||
                                    si.si_af != _rpcaf)
                                        continue;
                        } else if (si.si_af != _rpcaf)
                                        continue;
                        error = create_service(_rpcfd, nconf, &si);
                        if (error) {
                                endnetconfig(nc_handle);
                                exit(1);
                        }
                        ntrans++;
                }
        }
        endnetconfig(nc_handle);
        while(!(SLIST_EMPTY(&ble_head)))
                SLIST_REMOVE_HEAD(&ble_head, ble_next);
        if (ntrans == 0) {
                _msgout("no transport is available.  Aborted.");
                exit(1);
        }
        if (_rpcpmstart) {
                (void) signal(SIGALRM, (SIG_PF) closedown);
                (void) alarm(_RPCSVC_CLOSEDOWN/2);
        }
/*
 * Make sure SIGPIPE doesn't blow us away while servicing TCP
 * connections.
 */
        (void) signal(SIGPIPE, SIG_IGN);
        (void) signal(SIGCHLD, (SIG_PF) reaper);
        (void) signal(SIGTERM, (SIG_PF) reaper);
        (void) signal(SIGINT, (SIG_PF) reaper);
        (void) signal(SIGHUP, (SIG_PF) reaper);
        yp_svc_run();
        _msgout("svc_run returned");
        exit(1);
        /* NOTREACHED */
}