/*      $NetBSD: fingerd.c,v 1.27 2012/03/15 02:02:21 joerg Exp $       */

/*
 * Copyright (c) 1983, 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
__COPYRIGHT("@(#) Copyright (c) 1983, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "from: @(#)fingerd.c     8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: fingerd.c,v 1.27 2012/03/15 02:02:21 joerg Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>

#include <unistd.h>
#include <syslog.h>
#include <netdb.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pathnames.h"

__dead static void my_err(const char *, ...) __printflike(1, 2);

int
main(int argc, char *argv[])
{
        FILE *fp;
        int ch, ac = 2;
        char *lp = NULL /* XXX gcc */;
        struct sockaddr_storage ss;
        int p[2], logging, no_forward, user_required, short_list;
        socklen_t sval;
#define ENTRIES 50
        char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog, *s;
#if 0
        const char *av[ENTRIES + 1], **comp;
        const char *prog;
#endif
        char hostbuf[MAXHOSTNAMELEN];

        prog = __UNCONST(_PATH_FINGER);
        logging = no_forward = user_required = short_list = 0;
        openlog("fingerd", LOG_PID, LOG_DAEMON);
        opterr = 0;
        while ((ch = getopt(argc, argv, "gsluShmpP:8")) != -1) {
                switch (ch) {
                case 'l':
                        logging = 1;
                        break;
                case 'P':
                        prog = optarg;
                        break;
                case 's':
                        no_forward = 1;
                        break;
                case 'u':
                        user_required = 1;
                        break;
                case 'S':
                        short_list = 1;
                        av[ac++] = __UNCONST("-s");
                        break;
                case 'h':
                        av[ac++] = __UNCONST("-h");
                        break;
                case 'm':
                        av[ac++] = __UNCONST("-m");
                        break;
                case 'p':
                        av[ac++] = __UNCONST("-p");
                        break;
                case 'g':
                        av[ac++] = __UNCONST("-g");
                        break;
                case '8':
                        av[ac++] = __UNCONST("-8");
                        break;
                case '?':
                default:
                        my_err("illegal option -- %c", optopt);
                }
                if (ac >= ENTRIES)
                        my_err("Too many options provided");
        }


        if (logging) {
                sval = sizeof(ss);
                if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
                        my_err("getpeername: %s", strerror(errno));
                (void)getnameinfo((struct sockaddr *)&ss, sval,
                                hostbuf, sizeof(hostbuf), NULL, 0, 0);
                lp = hostbuf;
        }
        
        if (!fgets(line, sizeof(line), stdin)) {
                if (logging)
                        syslog(LOG_NOTICE, "query from %s", lp);
                exit(1);
        }
        while ((s = strrchr(line, '\n')) != NULL ||
            (s = strrchr(line, '\r')) != NULL)
                *s = '\0';

        if (logging) {
                if (*line == '\0')
                        syslog(LOG_NOTICE, "query from %s", lp);
                else
                        syslog(LOG_NOTICE, "query from %s: %s", lp, line);
        }

        if (ac >= ENTRIES)
                my_err("Too many options provided");
        av[ac++] = __UNCONST("--");
        comp = &av[1];
        for (lp = line, ap = &av[ac]; ac < ENTRIES;) {
                if ((*ap = strtok(lp, " \t\r\n")) == NULL)
                        break;
                lp = NULL;
                if (no_forward && strchr(*ap, '@')) {
                        (void) puts("forwarding service denied\r\n");
                        exit(1);
                }

                ch = strlen(*ap);
                while ((*ap)[ch-1] == '@')
                        (*ap)[--ch] = '\0';
                if (**ap == '\0')
                        continue;

                /* RFC1196: "/[Ww]" == "-l" */
                if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
                        if (!short_list) {
                                av[1] = __UNCONST("-l");
                                comp = &av[0];
                        }
                } else {
                        ap++;
                        ac++;
                }
        }
        av[ENTRIES - 1] = NULL;

        if ((lp = strrchr(prog, '/')))
                *comp = ++lp;
        else
                *comp = prog;

        if (user_required) {
                for (ap = comp + 1; strcmp("--", *(ap++)); );
                if (*ap == NULL) {
                        (void) puts("must provide username\r\n");
                        exit(1);
                }
        }

        if (pipe(p) < 0)
                my_err("pipe: %s", strerror(errno));

        switch(fork()) {
        case 0:
                (void) close(p[0]);
                if (p[1] != 1) {
                        (void) dup2(p[1], 1);
                        (void) close(p[1]);
                }
                execv(prog, comp);
                my_err("execv: %s: %s", prog, strerror(errno));
                _exit(1);
        case -1:
                my_err("fork: %s", strerror(errno));
        }
        (void) close(p[1]);
        if (!(fp = fdopen(p[0], "r")))
                my_err("fdopen: %s", strerror(errno));
        while ((ch = getc(fp)) != EOF) {
                if (ch == '\n')
                        putchar('\r');
                putchar(ch);
        }
        exit(0);
}

static void
my_err(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        (void) vsyslog(LOG_ERR, fmt, ap);
        va_end(ap);
        exit(1);
        /* NOTREACHED */
}