usr/src/libexec/fingerd/fingerd.c

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1983, 1993\n\
        The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)fingerd.c   8.1 (Berkeley) %G%";
#endif /* not lint */

#include <sys/types.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 <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include "pathnames.h"

void err __P((const char *, ...));

int
main(argc, argv)
        int argc;
        char *argv[];
{
        register FILE *fp;
        register int ch;
        register char *lp;
        struct hostent *hp;
        struct sockaddr_in sin;
        int p[2], logging, secure, sval;
#define ENTRIES 50
        char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;

        prog = _PATH_FINGER;
        logging = secure = 0;
        openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
        opterr = 0;
        while ((ch = getopt(argc, argv, "slp:")) != EOF)
                switch (ch) {
                case 'l':
                        logging = 1;
                        break;
                case 'p':
                        prog = optarg;
                        break;
                case 's':
                        secure = 1;
                        break;
                case '?':
                default:
                        err("illegal option -- %c", ch);
                }

        if (logging) {
                sval = sizeof(sin);
                if (getpeername(0, (struct sockaddr *)&sin, &sval) < 0)
                        err("getpeername: %s", strerror(errno));
                if (hp = gethostbyaddr((char *)&sin.sin_addr.s_addr,
                    sizeof(sin.sin_addr.s_addr), AF_INET))
                        lp = hp->h_name;
                else
                        lp = inet_ntoa(sin.sin_addr);
                syslog(LOG_NOTICE, "query from %s", lp);
        }

        if (!fgets(line, sizeof(line), stdin))
                exit(1);

        comp = &av[1];
        for (lp = line, ap = &av[2];;) {
                *ap = strtok(lp, " \t\r\n");
                if (!*ap) {
                        if (secure && ap == &av[2]) {
                                puts("must provide username\r\n");
                                exit(1);
                        }
                        break;
                }
                if (secure && strchr(*ap, '@')) {
                        puts("fowarding service denied\r\n");
                        exit(1);
                }

                /* RFC742: "/[Ww]" == "-l" */
                if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
                        av[1] = "-l";
                        comp = &av[0];
                }
                else if (++ap == av + ENTRIES)
                        break;
                lp = NULL;
        }

        if (lp = strrchr(prog, '/'))
                *comp = ++lp;
        else
                *comp = prog;
        if (pipe(p) < 0)
                err("pipe: %s", strerror(errno));

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

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#if __STDC__
err(const char *fmt, ...)
#else
err(fmt, va_alist)
        char *fmt;
        va_dcl
#endif
{
        va_list ap;
#if __STDC__
        va_start(ap, fmt);
#else
        va_start(ap);
#endif
        (void)vsyslog(LOG_ERR, fmt, ap);
        va_end(ap);
        exit(1);
        /* NOTREACHED */
}