libexec/httpd/tilde-luzah-bozo.c

   1 /*      $NetBSD: tilde-luzah-bozo.c,v 1.4 2009/02/04 22:55:58 tls Exp $ */
   2
   3 /*      $eterna: tilde-luzah-bozo.c,v 1.10 2009/04/18 05:36:04 mrg Exp $        */
   4
   5 /*
   6  * Copyright (c) 1997-2009 Matthew R. Green
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer and
  16  *    dedication in the documentation and/or other materials provided
  17  *    with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  27  * 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
  33 /* this code implements ~user support for bozohttpd */
  34
  35 #ifndef NO_USER_SUPPORT
  36
  37 #include <sys/param.h>
  38
  39 #include <errno.h>
  40 #include <pwd.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43 #include <unistd.h>
  44
  45 #include "bozohttpd.h"
  46
  47 #ifndef PUBLIC_HTML
  48 #define PUBLIC_HTML             "public_html"
  49 #endif
  50
  51         int     uflag;          /* allow /~user/ translation */
  52         const char *public_html = PUBLIC_HTML;
  53
  54 /*
  55  * user_transform does this:
  56  *      - chdir's /~user/public_html
  57  *      - returns the rest of the file, index.html appended if required
  58  *      - returned malloced file to serve in request->hr_file,
  59  *        ala transform_request().
  60  *
  61  * transform_request() is supposed to check that we have user support
  62  * enabled.
  63  */
  64 int
  65 user_transform(request, isindex)
  66         http_req *request;
  67         int *isindex;
  68 {
  69         char    c, *s, *file = NULL;
  70         struct  passwd *pw;
  71
  72         *isindex = 0;
  73
  74         if ((s = strchr(request->hr_file + 2, '/')) != NULL) {
  75                 *s++ = '\0';
  76                 c = s[strlen(s)-1];
  77                 *isindex = (c == '/' || c == '\0');
  78         }
  79
  80         debug((DEBUG_OBESE, "looking for user %s", request->hr_file + 2));
  81         pw = getpwnam(request->hr_file + 2);
  82         /* fix this up immediately */
  83         if (s)
  84                 s[-1] = '/';
  85         if (pw == NULL) {
  86                 (void)http_error(404, request, "no such user");
  87                 return 0;
  88         }
  89
  90         debug((DEBUG_OBESE, "user %s home dir %s uid %d gid %d", pw->pw_name,
  91             pw->pw_dir, pw->pw_uid, pw->pw_gid));
  92
  93         if (chdir(pw->pw_dir) < 0) {
  94                 warning("chdir1 error: %s: %s", pw->pw_dir, strerror(errno));
  95                 (void)http_error(403, request, "can't chdir to homedir");
  96                 return 0;
  97         }
  98         if (chdir(public_html) < 0) {
  99                 warning("chdir2 error: %s: %s", public_html, strerror(errno));
 100                 (void)http_error(403, request, "can't chdir to public_html");
 101                 return 0;
 102         }
 103         if (s == NULL || *s == '\0') {
 104                 file = bozostrdup(index_html);
 105         } else {
 106                 file = bozomalloc(strlen(s) +
 107                     (*isindex ? strlen(index_html) + 1 : 1));
 108                 strcpy(file, s);
 109                 if (*isindex)
 110                         strcat(file, index_html);
 111         }
 112
 113         /* see transform_request() */
 114         if (*file == '/' || strcmp(file, "..") == 0 ||
 115             strstr(file, "/..") || strstr(file, "../")) {
 116                 (void)http_error(403, request, "illegal request");
 117                 free(file);
 118                 return 0;
 119         }
 120
 121         if (auth_check(request, file)) {
 122                 free(file);
 123                 return 0;
 124         }
 125
 126         free(request->hr_file);
 127         request->hr_file = file;
 128
 129         debug((DEBUG_FAT, "transform_user returning %s under %s", file,
 130             pw->pw_dir));
 131         return 1;
 132 }
 133 #endif /* NO_USER_SUPPORT */