1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 /*
18 * mod_userdir... implement the UserDir command. Broken away from the
19 * Alias stuff for a couple of good and not-so-good reasons:
20 *
21 * 1) It shows a real minimal working example of how to do something like
22 * this.
23 * 2) I know people who are actually interested in changing this *particular*
24 * aspect of server functionality without changing the rest of it. That's
25 * what this whole modular arrangement is supposed to be good at...
26 *
27 * Modified by Alexei Kosut to support the following constructs
28 * (server running at www.foo.com, request for /~bar/one/two.html)
29 *
30 * UserDir public_html -> ~bar/public_html/one/two.html
31 * UserDir /usr/web -> /usr/web/bar/one/two.html
32 * UserDir /home/ * /www -> /home/bar/www/one/two.html
33 * NOTE: theses ^ ^ space only added allow it to work in a comment, ignore
34 * UserDir http://x/users -> (302) http://x/users/bar/one/two.html
35 * UserDir http://x/ * /y -> (302) http://x/bar/y/one/two.html
36 * NOTE: here also ^ ^
37 *
38 * In addition, you can use multiple entries, to specify alternate
39 * user directories (a la Directory Index). For example:
40 *
41 * UserDir public_html /usr/web http://www.xyz.com/users
42 *
43 * Modified by Ken Coar to provide for the following:
44 *
45 * UserDir disable[d] username ...
46 * UserDir enable[d] username ...
47 *
48 * If "disabled" has no other arguments, *all* ~<username> references are
49 * disabled, except those explicitly turned on with the "enabled" keyword.
50 */
51
52 #include "apr_strings.h"
53 #include "apr_user.h"
54
55 #define APR_WANT_STRFUNC
56 #include "apr_want.h"
57
58 #if APR_HAVE_UNISTD_H
59 #include <unistd.h>
60 #endif
61
62 #include "ap_config.h"
63 #include "httpd.h"
64 #include "http_config.h"
65 #include "http_request.h"
66
67 #if !defined(WIN32) && !defined(OS2) && !defined(NETWARE)
68 #define HAVE_UNIX_SUEXEC
69 #endif
70
71 #ifdef HAVE_UNIX_SUEXEC
72 #include "unixd.h" /* Contains the suexec_identity hook used on Unix */
73 #endif
74
75
76 /*
77 * The default directory in user's home dir
78 * In the default install, the module is disabled
79 */
80 #ifndef DEFAULT_USER_DIR
81 #define DEFAULT_USER_DIR NULL
82 #endif
83
84 #define O_DEFAULT 0
85 #define O_ENABLE 1
86 #define O_DISABLE 2
87
88 module AP_MODULE_DECLARE_DATA userdir_module;
89
90 typedef struct {
91 int globally_disabled;
92 const char *userdir;
93 apr_table_t *enabled_users;
94 apr_table_t *disabled_users;
95 } userdir_config;
96
97 /*
98 * Server config for this module: global disablement flag, a list of usernames
99 * ineligible for UserDir access, a list of those immune to global (but not
100 * explicit) disablement, and the replacement string for all others.
101 */
102
create_userdir_config(apr_pool_t * p,server_rec * s)103 static void *create_userdir_config(apr_pool_t *p, server_rec *s)
104 {
105 userdir_config *newcfg = apr_pcalloc(p, sizeof(*newcfg));
106
107 newcfg->globally_disabled = O_DEFAULT;
108 newcfg->userdir = DEFAULT_USER_DIR;
109 newcfg->enabled_users = apr_table_make(p, 4);
110 newcfg->disabled_users = apr_table_make(p, 4);
111
112 return newcfg;
113 }
114
merge_userdir_config(apr_pool_t * p,void * basev,void * overridesv)115 static void *merge_userdir_config(apr_pool_t *p, void *basev, void *overridesv)
116 {
117 userdir_config *cfg = apr_pcalloc(p, sizeof(userdir_config));
118 userdir_config *base = basev, *overrides = overridesv;
119
120 cfg->globally_disabled = (overrides->globally_disabled != O_DEFAULT) ?
121 overrides->globally_disabled :
122 base->globally_disabled;
123 cfg->userdir = (overrides->userdir != DEFAULT_USER_DIR) ?
124 overrides->userdir : base->userdir;
125
126 /* not merged */
127 cfg->enabled_users = overrides->enabled_users;
128 cfg->disabled_users = overrides->disabled_users;
129
130 return cfg;
131 }
132
133
set_user_dir(cmd_parms * cmd,void * dummy,const char * arg)134 static const char *set_user_dir(cmd_parms *cmd, void *dummy, const char *arg)
135 {
136 userdir_config *s_cfg = ap_get_module_config(cmd->server->module_config,
137 &userdir_module);
138 char *username;
139 const char *usernames = arg;
140 char *kw = ap_getword_conf(cmd->temp_pool, &usernames);
141 apr_table_t *usertable;
142
143 /* Since we are a raw argument, it is possible for us to be called with
144 * zero arguments. So that we aren't ambiguous, flat out reject this.
145 */
146 if (*kw == '\0') {
147 return "UserDir requires an argument.";
148 }
149
150 /*
151 * Let's do the comparisons once.
152 */
153 if ((!strcasecmp(kw, "disable")) || (!strcasecmp(kw, "disabled"))) {
154 /*
155 * If there are no usernames specified, this is a global disable - we
156 * need do no more at this point than record the fact.
157 */
158 if (!*usernames) {
159 s_cfg->globally_disabled = O_DISABLE;
160 return NULL;
161 }
162 usertable = s_cfg->disabled_users;
163 }
164 else if ((!strcasecmp(kw, "enable")) || (!strcasecmp(kw, "enabled"))) {
165 if (!*usernames) {
166 s_cfg->globally_disabled = O_ENABLE;
167 return NULL;
168 }
169 usertable = s_cfg->enabled_users;
170 }
171 else {
172 /*
173 * If the first (only?) value isn't one of our keywords, just copy
174 * the string to the userdir string.
175 */
176 s_cfg->userdir = arg;
177 return NULL;
178 }
179 /*
180 * Now we just take each word in turn from the command line and add it to
181 * the appropriate table.
182 */
183 while (*usernames) {
184 username = ap_getword_conf(cmd->pool, &usernames);
185 apr_table_setn(usertable, username, "1");
186 }
187 return NULL;
188 }
189
190 static const command_rec userdir_cmds[] = {
191 AP_INIT_RAW_ARGS("UserDir", set_user_dir, NULL, RSRC_CONF,
192 "the public subdirectory in users' home directories, or "
193 "'disabled', or 'disabled username username...', or "
194 "'enabled username username...'"),
195 {NULL}
196 };
197
translate_userdir(request_rec * r)198 static int translate_userdir(request_rec *r)
199 {
200 ap_conf_vector_t *server_conf;
201 const userdir_config *s_cfg;
202 const char *userdirs;
203 const char *user, *dname;
204 char *redirect;
205 apr_finfo_t statbuf;
206
207 /*
208 * If the URI doesn't match our basic pattern, we've nothing to do with
209 * it.
210 */
211 if (r->uri[0] != '/' || r->uri[1] != '~') {
212 return DECLINED;
213 }
214 server_conf = r->server->module_config;
215 s_cfg = ap_get_module_config(server_conf, &userdir_module);
216 userdirs = s_cfg->userdir;
217 if (userdirs == NULL) {
218 return DECLINED;
219 }
220
221 dname = r->uri + 2;
222 user = ap_getword(r->pool, &dname, '/');
223
224 /*
225 * The 'dname' funny business involves backing it up to capture the '/'
226 * delimiting the "/~user" part from the rest of the URL, in case there
227 * was one (the case where there wasn't being just "GET /~user HTTP/1.0",
228 * for which we don't want to tack on a '/' onto the filename).
229 */
230
231 if (dname[-1] == '/') {
232 --dname;
233 }
234
235 /*
236 * If there's no username, it's not for us. Ignore . and .. as well.
237 */
238 if (user[0] == '\0' ||
239 (user[1] == '.' && (user[2] == '\0' ||
240 (user[2] == '.' && user[3] == '\0')))) {
241 return DECLINED;
242 }
243 /*
244 * Nor if there's an username but it's in the disabled list.
245 */
246 if (apr_table_get(s_cfg->disabled_users, user) != NULL) {
247 return DECLINED;
248 }
249 /*
250 * If there's a global interdiction on UserDirs, check to see if this
251 * name is one of the Blessed.
252 */
253 if (s_cfg->globally_disabled == O_DISABLE
254 && apr_table_get(s_cfg->enabled_users, user) == NULL) {
255 return DECLINED;
256 }
257
258 /*
259 * Special cases all checked, onward to normal substitution processing.
260 */
261
262 while (*userdirs) {
263 const char *userdir = ap_getword_conf(r->pool, &userdirs);
264 char *filename = NULL, *prefix = NULL;
265 apr_status_t rv;
266 int is_absolute = ap_os_is_path_absolute(r->pool, userdir);
267
268 if (ap_strchr_c(userdir, '*'))
269 prefix = ap_getword(r->pool, &userdir, '*');
270
271 if (userdir[0] == '\0' || is_absolute) {
272 if (prefix) {
273 #ifdef HAVE_DRIVE_LETTERS
274 /*
275 * Crummy hack. Need to figure out whether we have been
276 * redirected to a URL or to a file on some drive. Since I
277 * know of no protocols that are a single letter, ignore
278 * a : as the first or second character, and assume a file
279 * was specified
280 */
281 if (strchr(prefix + 2, ':'))
282 #else
283 if (strchr(prefix, ':') && !is_absolute)
284 #endif /* HAVE_DRIVE_LETTERS */
285 {
286 redirect = apr_pstrcat(r->pool, prefix, user, userdir,
287 dname, NULL);
288 apr_table_setn(r->headers_out, "Location", redirect);
289 return HTTP_MOVED_TEMPORARILY;
290 }
291 else
292 filename = apr_pstrcat(r->pool, prefix, user, userdir,
293 NULL);
294 }
295 else
296 filename = apr_pstrcat(r->pool, userdir, "/", user, NULL);
297 }
298 else if (prefix && ap_strchr_c(prefix, ':')) {
299 redirect = apr_pstrcat(r->pool, prefix, user, dname, NULL);
300 apr_table_setn(r->headers_out, "Location", redirect);
301 return HTTP_MOVED_TEMPORARILY;
302 }
303 else {
304 #if APR_HAS_USER
305 char *homedir;
306
307 if (apr_uid_homepath_get(&homedir, user, r->pool) == APR_SUCCESS) {
308 filename = apr_pstrcat(r->pool, homedir, "/", userdir, NULL);
309 }
310 #else
311 return DECLINED;
312 #endif
313 }
314
315 /*
316 * Now see if it exists, or we're at the last entry. If we are at the
317 * last entry, then use the filename generated (if there is one)
318 * anyway, in the hope that some handler might handle it. This can be
319 * used, for example, to run a CGI script for the user.
320 */
321 if (filename && (!*userdirs
322 || ((rv = apr_stat(&statbuf, filename, APR_FINFO_MIN,
323 r->pool)) == APR_SUCCESS
324 || rv == APR_INCOMPLETE))) {
325 r->filename = apr_pstrcat(r->pool, filename, dname, NULL);
326 ap_set_context_info(r, apr_pstrmemdup(r->pool, r->uri,
327 dname - r->uri),
328 filename);
329 /* XXX: Does this walk us around FollowSymLink rules?
330 * When statbuf contains info on r->filename we can save a syscall
331 * by copying it to r->finfo
332 */
333 if (*userdirs && dname[0] == 0)
334 r->finfo = statbuf;
335
336 /* For use in the get_suexec_identity phase */
337 apr_table_setn(r->notes, "mod_userdir_user", user);
338
339 return OK;
340 }
341 }
342
343 return DECLINED;
344 }
345
346 #ifdef HAVE_UNIX_SUEXEC
get_suexec_id_doer(const request_rec * r)347 static ap_unix_identity_t *get_suexec_id_doer(const request_rec *r)
348 {
349 ap_unix_identity_t *ugid = NULL;
350 #if APR_HAS_USER
351 const char *username = apr_table_get(r->notes, "mod_userdir_user");
352
353 if (username == NULL) {
354 return NULL;
355 }
356
357 if ((ugid = apr_palloc(r->pool, sizeof(*ugid))) == NULL) {
358 return NULL;
359 }
360
361 if (apr_uid_get(&ugid->uid, &ugid->gid, username, r->pool) != APR_SUCCESS) {
362 return NULL;
363 }
364
365 ugid->userdir = 1;
366 #endif
367 return ugid;
368 }
369 #endif /* HAVE_UNIX_SUEXEC */
370
register_hooks(apr_pool_t * p)371 static void register_hooks(apr_pool_t *p)
372 {
373 static const char * const aszPre[]={ "mod_alias.c",NULL };
374 static const char * const aszSucc[]={ "mod_vhost_alias.c",NULL };
375
376 ap_hook_translate_name(translate_userdir,aszPre,aszSucc,APR_HOOK_MIDDLE);
377 #ifdef HAVE_UNIX_SUEXEC
378 ap_hook_get_suexec_identity(get_suexec_id_doer,NULL,NULL,APR_HOOK_FIRST);
379 #endif
380 }
381
382 AP_DECLARE_MODULE(userdir) = {
383 STANDARD20_MODULE_STUFF,
384 NULL, /* dir config creater */
385 NULL, /* dir merger --- default is to override */
386 create_userdir_config, /* server config */
387 merge_userdir_config, /* merge server config */
388 userdir_cmds, /* command apr_table_t */
389 register_hooks /* register hooks */
390 };
391