libexec/fingerd/fingerd.c

   1 /*      $NetBSD: fingerd.c,v 1.27 2012/03/15 02:02:21 joerg Exp $       */
   2
   3 /*
   4  * Copyright (c) 1983, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "from: @(#)fingerd.c     8.1 (Berkeley) 6/4/93";
  41 #else
  42 __RCSID("$NetBSD: fingerd.c,v 1.27 2012/03/15 02:02:21 joerg Exp $");
  43 #endif
  44 #endif /* not lint */
  45
  46 #include <sys/param.h>
  47 #include <sys/socket.h>
  48 #include <netinet/in.h>
  49 #include <arpa/inet.h>
  50 #include <errno.h>
  51
  52 #include <unistd.h>
  53 #include <syslog.h>
  54 #include <netdb.h>
  55 #include <stdarg.h>
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <string.h>
  59 #include "pathnames.h"
  60
  61 __dead static void my_err(const char *, ...) __printflike(1, 2);
  62
  63 int
  64 main(int argc, char *argv[])
  65 {
  66         FILE *fp;
  67         int ch, ac = 2;
  68         char *lp = NULL /* XXX gcc */;
  69         struct sockaddr_storage ss;
  70         int p[2], logging, no_forward, user_required, short_list;
  71         socklen_t sval;
  72 #define ENTRIES 50
  73         char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog, *s;
  74 #if 0
  75         const char *av[ENTRIES + 1], **comp;
  76         const char *prog;
  77 #endif
  78         char hostbuf[MAXHOSTNAMELEN];
  79
  80         prog = __UNCONST(_PATH_FINGER);
  81         logging = no_forward = user_required = short_list = 0;
  82         openlog("fingerd", LOG_PID, LOG_DAEMON);
  83         opterr = 0;
  84         while ((ch = getopt(argc, argv, "gsluShmpP:8")) != -1) {
  85                 switch (ch) {
  86                 case 'l':
  87                         logging = 1;
  88                         break;
  89                 case 'P':
  90                         prog = optarg;
  91                         break;
  92                 case 's':
  93                         no_forward = 1;
  94                         break;
  95                 case 'u':
  96                         user_required = 1;
  97                         break;
  98                 case 'S':
  99                         short_list = 1;
 100                         av[ac++] = __UNCONST("-s");
 101                         break;
 102                 case 'h':
 103                         av[ac++] = __UNCONST("-h");
 104                         break;
 105                 case 'm':
 106                         av[ac++] = __UNCONST("-m");
 107                         break;
 108                 case 'p':
 109                         av[ac++] = __UNCONST("-p");
 110                         break;
 111                 case 'g':
 112                         av[ac++] = __UNCONST("-g");
 113                         break;
 114                 case '8':
 115                         av[ac++] = __UNCONST("-8");
 116                         break;
 117                 case '?':
 118                 default:
 119                         my_err("illegal option -- %c", optopt);
 120                 }
 121                 if (ac >= ENTRIES)
 122                         my_err("Too many options provided");
 123         }
 124
 125
 126         if (logging) {
 127                 sval = sizeof(ss);
 128                 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
 129                         my_err("getpeername: %s", strerror(errno));
 130                 (void)getnameinfo((struct sockaddr *)&ss, sval,
 131                                 hostbuf, sizeof(hostbuf), NULL, 0, 0);
 132                 lp = hostbuf;
 133         }
 134
 135         if (!fgets(line, sizeof(line), stdin)) {
 136                 if (logging)
 137                         syslog(LOG_NOTICE, "query from %s", lp);
 138                 exit(1);
 139         }
 140         while ((s = strrchr(line, '\n')) != NULL ||
 141             (s = strrchr(line, '\r')) != NULL)
 142                 *s = '\0';
 143
 144         if (logging) {
 145                 if (*line == '\0')
 146                         syslog(LOG_NOTICE, "query from %s", lp);
 147                 else
 148                         syslog(LOG_NOTICE, "query from %s: %s", lp, line);
 149         }
 150
 151         if (ac >= ENTRIES)
 152                 my_err("Too many options provided");
 153         av[ac++] = __UNCONST("--");
 154         comp = &av[1];
 155         for (lp = line, ap = &av[ac]; ac < ENTRIES;) {
 156                 if ((*ap = strtok(lp, " \t\r\n")) == NULL)
 157                         break;
 158                 lp = NULL;
 159                 if (no_forward && strchr(*ap, '@')) {
 160                         (void) puts("forwarding service denied\r\n");
 161                         exit(1);
 162                 }
 163
 164                 ch = strlen(*ap);
 165                 while ((*ap)[ch-1] == '@')
 166                         (*ap)[--ch] = '\0';
 167                 if (**ap == '\0')
 168                         continue;
 169
 170                 /* RFC1196: "/[Ww]" == "-l" */
 171                 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
 172                         if (!short_list) {
 173                                 av[1] = __UNCONST("-l");
 174                                 comp = &av[0];
 175                         }
 176                 } else {
 177                         ap++;
 178                         ac++;
 179                 }
 180         }
 181         av[ENTRIES - 1] = NULL;
 182
 183         if ((lp = strrchr(prog, '/')))
 184                 *comp = ++lp;
 185         else
 186                 *comp = prog;
 187
 188         if (user_required) {
 189                 for (ap = comp + 1; strcmp("--", *(ap++)); );
 190                 if (*ap == NULL) {
 191                         (void) puts("must provide username\r\n");
 192                         exit(1);
 193                 }
 194         }
 195
 196         if (pipe(p) < 0)
 197                 my_err("pipe: %s", strerror(errno));
 198
 199         switch(fork()) {
 200         case 0:
 201                 (void) close(p[0]);
 202                 if (p[1] != 1) {
 203                         (void) dup2(p[1], 1);
 204                         (void) close(p[1]);
 205                 }
 206                 execv(prog, comp);
 207                 my_err("execv: %s: %s", prog, strerror(errno));
 208                 _exit(1);
 209         case -1:
 210                 my_err("fork: %s", strerror(errno));
 211         }
 212         (void) close(p[1]);
 213         if (!(fp = fdopen(p[0], "r")))
 214                 my_err("fdopen: %s", strerror(errno));
 215         while ((ch = getc(fp)) != EOF) {
 216                 if (ch == '\n')
 217                         putchar('\r');
 218                 putchar(ch);
 219         }
 220         exit(0);
 221 }
 222
 223 static void
 224 my_err(const char *fmt, ...)
 225 {
 226         va_list ap;
 227
 228         va_start(ap, fmt);
 229         (void) vsyslog(LOG_ERR, fmt, ap);
 230         va_end(ap);
 231         exit(1);
 232         /* NOTREACHED */
 233 }