libexec/fingerd/fingerd.c

   1 /*      $NetBSD: fingerd.c,v 1.24 2008/07/20 01:09:07 lukem 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 1.24 2008/07/20 01:09:07 lukem 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 void err(const char *, ...);
  62 int main(int, char *[]);
  63
  64 int
  65 main(int argc, char *argv[])
  66 {
  67         FILE *fp;
  68         int ch, ac = 2;
  69         char *lp = NULL /* XXX gcc */;
  70         struct sockaddr_storage ss;
  71         int p[2], logging, no_forward, user_required, short_list;
  72         socklen_t sval;
  73 #define ENTRIES 50
  74         char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog, *s;
  75 #if 0
  76         const char *av[ENTRIES + 1], **comp;
  77         const char *prog;
  78 #endif
  79         char hostbuf[MAXHOSTNAMELEN];
  80
  81         prog = __UNCONST(_PATH_FINGER);
  82         logging = no_forward = user_required = short_list = 0;
  83         openlog("fingerd", LOG_PID, LOG_DAEMON);
  84         opterr = 0;
  85         while ((ch = getopt(argc, argv, "gsluShmpP:8")) != -1) {
  86                 switch (ch) {
  87                 case 'l':
  88                         logging = 1;
  89                         break;
  90                 case 'P':
  91                         prog = optarg;
  92                         break;
  93                 case 's':
  94                         no_forward = 1;
  95                         break;
  96                 case 'u':
  97                         user_required = 1;
  98                         break;
  99                 case 'S':
 100                         short_list = 1;
 101                         av[ac++] = __UNCONST("-s");
 102                         break;
 103                 case 'h':
 104                         av[ac++] = __UNCONST("-h");
 105                         break;
 106                 case 'm':
 107                         av[ac++] = __UNCONST("-m");
 108                         break;
 109                 case 'p':
 110                         av[ac++] = __UNCONST("-p");
 111                         break;
 112                 case 'g':
 113                         av[ac++] = __UNCONST("-g");
 114                         break;
 115                 case '8':
 116                         av[ac++] = __UNCONST("-8");
 117                         break;
 118                 case '?':
 119                 default:
 120                         err("illegal option -- %c", optopt);
 121                 }
 122                 if (ac >= ENTRIES)
 123                         err("Too many options provided");
 124         }
 125
 126
 127         if (logging) {
 128                 sval = sizeof(ss);
 129                 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
 130                         err("getpeername: %s", strerror(errno));
 131                 (void)getnameinfo((struct sockaddr *)&ss, sval,
 132                                 hostbuf, sizeof(hostbuf), NULL, 0, 0);
 133                 lp = hostbuf;
 134         }
 135
 136         if (!fgets(line, sizeof(line), stdin)) {
 137                 if (logging)
 138                         syslog(LOG_NOTICE, "query from %s", lp);
 139                 exit(1);
 140         }
 141         while ((s = strrchr(line, '\n')) != NULL ||
 142             (s = strrchr(line, '\r')) != NULL)
 143                 *s = '\0';
 144
 145         if (logging) {
 146                 if (*line == '\0')
 147                         syslog(LOG_NOTICE, "query from %s", lp);
 148                 else
 149                         syslog(LOG_NOTICE, "query from %s: %s", lp, line);
 150         }
 151
 152         if (ac >= ENTRIES)
 153                 err("Too many options provided");
 154         av[ac++] = __UNCONST("--");
 155         comp = &av[1];
 156         for (lp = line, ap = &av[ac]; ac < ENTRIES;) {
 157                 if ((*ap = strtok(lp, " \t\r\n")) == NULL)
 158                         break;
 159                 lp = NULL;
 160                 if (no_forward && strchr(*ap, '@')) {
 161                         (void) puts("forwarding service denied\r\n");
 162                         exit(1);
 163                 }
 164
 165                 ch = strlen(*ap);
 166                 while ((*ap)[ch-1] == '@')
 167                         (*ap)[--ch] = '\0';
 168                 if (**ap == '\0')
 169                         continue;
 170
 171                 /* RFC1196: "/[Ww]" == "-l" */
 172                 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
 173                         if (!short_list) {
 174                                 av[1] = __UNCONST("-l");
 175                                 comp = &av[0];
 176                         }
 177                 } else {
 178                         ap++;
 179                         ac++;
 180                 }
 181         }
 182         av[ENTRIES - 1] = NULL;
 183
 184         if ((lp = strrchr(prog, '/')))
 185                 *comp = ++lp;
 186         else
 187                 *comp = prog;
 188
 189         if (user_required) {
 190                 for (ap = comp + 1; strcmp("--", *(ap++)); );
 191                 if (*ap == NULL) {
 192                         (void) puts("must provide username\r\n");
 193                         exit(1);
 194                 }
 195         }
 196
 197         if (pipe(p) < 0)
 198                 err("pipe: %s", strerror(errno));
 199
 200         switch(fork()) {
 201         case 0:
 202                 (void) close(p[0]);
 203                 if (p[1] != 1) {
 204                         (void) dup2(p[1], 1);
 205                         (void) close(p[1]);
 206                 }
 207                 execv(prog, comp);
 208                 err("execv: %s: %s", prog, strerror(errno));
 209                 _exit(1);
 210         case -1:
 211                 err("fork: %s", strerror(errno));
 212         }
 213         (void) close(p[1]);
 214         if (!(fp = fdopen(p[0], "r")))
 215                 err("fdopen: %s", strerror(errno));
 216         while ((ch = getc(fp)) != EOF) {
 217                 if (ch == '\n')
 218                         putchar('\r');
 219                 putchar(ch);
 220         }
 221         exit(0);
 222 }
 223
 224 void
 225 err(const char *fmt, ...)
 226 {
 227         va_list ap;
 228
 229         va_start(ap, fmt);
 230         (void) vsyslog(LOG_ERR, fmt, ap);
 231         va_end(ap);
 232         exit(1);
 233         /* NOTREACHED */
 234 }