/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* mod_userdir... implement the UserDir command. Broken away from the
* Alias stuff for a couple of good and not-so-good reasons:
*
* 1) It shows a real minimal working example of how to do something like
* this.
* 2) I know people who are actually interested in changing this *particular*
* aspect of server functionality without changing the rest of it. That's
* what this whole modular arrangement is supposed to be good at...
*
* Modified by Alexei Kosut to support the following constructs
* (server running at www.foo.com, request for /~bar/one/two.html)
*
* UserDir public_html -> ~bar/public_html/one/two.html
* UserDir /usr/web -> /usr/web/bar/one/two.html
* UserDir /home/ * /www -> /home/bar/www/one/two.html
* NOTE: theses ^ ^ space only added allow it to work in a comment, ignore
* UserDir http://x/users -> (302) http://x/users/bar/one/two.html
* UserDir http://x/ * /y -> (302) http://x/bar/y/one/two.html
* NOTE: here also ^ ^
*
* In addition, you can use multiple entries, to specify alternate
* user directories (a la Directory Index). For example:
*
* UserDir public_html /usr/web http://www.xyz.com/users
*
* Modified by Ken Coar to provide for the following:
*
* UserDir disable[d] username ...
* UserDir enable[d] username ...
*
* If "disabled" has no other arguments, *all* ~<username> references are
* disabled, except those explicitly turned on with the "enabled" keyword.
*/
#include "apr_strings.h"
#include "apr_user.h"
#define APR_WANT_STRFUNC
#include "apr_want.h"
#if APR_HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "ap_config.h"
#include "httpd.h"
#include "http_config.h"
#include "http_request.h"
#if !defined(WIN32) && !defined(OS2) && !defined(NETWARE)
#define HAVE_UNIX_SUEXEC
#endif
#ifdef HAVE_UNIX_SUEXEC
#include "unixd.h" /* Contains the suexec_identity hook used on Unix */
#endif
/*
* The default directory in user's home dir
* In the default install, the module is disabled
*/
#ifndef DEFAULT_USER_DIR
#define DEFAULT_USER_DIR NULL
#endif
#define O_DEFAULT 0
#define O_ENABLE 1
#define O_DISABLE 2
module AP_MODULE_DECLARE_DATA userdir_module;
typedef struct {
int globally_disabled;
char *userdir;
apr_table_t *enabled_users;
apr_table_t *disabled_users;
} userdir_config;
/*
* Server config for this module: global disablement flag, a list of usernames
* ineligible for UserDir access, a list of those immune to global (but not
* explicit) disablement, and the replacement string for all others.
*/
static void *create_userdir_config(apr_pool_t *p, server_rec *s)
{
userdir_config *newcfg = apr_pcalloc(p, sizeof(*newcfg));
newcfg->globally_disabled = O_DEFAULT;
newcfg->userdir = DEFAULT_USER_DIR;
newcfg->enabled_users = apr_table_make(p, 4);
newcfg->disabled_users = apr_table_make(p, 4);
return newcfg;
}
static void *merge_userdir_config(apr_pool_t *p, void *basev, void *overridesv)
{
userdir_config *cfg = apr_pcalloc(p, sizeof(userdir_config));
userdir_config *base = basev, *overrides = overridesv;
cfg->globally_disabled = (overrides->globally_disabled != O_DEFAULT) ?
overrides->globally_disabled :
base->globally_disabled;
cfg->userdir = (overrides->userdir != DEFAULT_USER_DIR) ?
overrides->userdir : base->userdir;
/* not merged */
cfg->enabled_users = overrides->enabled_users;
cfg->disabled_users = overrides->disabled_users;
return cfg;
}
static const char *set_user_dir(cmd_parms *cmd, void *dummy, const char *arg)
{
userdir_config *s_cfg = ap_get_module_config(cmd->server->module_config,
&userdir_module);
char *username;
const char *usernames = arg;
char *kw = ap_getword_conf(cmd->pool, &usernames);
apr_table_t *usertable;
/* Since we are a raw argument, it is possible for us to be called with
* zero arguments. So that we aren't ambiguous, flat out reject this.
*/
if (*kw == '\0') {
return "UserDir requires an argument.";
}
/*
* Let's do the comparisons once.
*/
if ((!strcasecmp(kw, "disable")) || (!strcasecmp(kw, "disabled"))) {
/*
* If there are no usernames specified, this is a global disable - we
* need do no more at this point than record the fact.
*/
if (!*usernames) {
s_cfg->globally_disabled = O_DISABLE;
return NULL;
}
usertable = s_cfg->disabled_users;
}
else if ((!strcasecmp(kw, "enable")) || (!strcasecmp(kw, "enabled"))) {
if (!*usernames) {
s_cfg->globally_disabled = O_ENABLE;
return NULL;
}
usertable = s_cfg->enabled_users;
}
else {
/*
* If the first (only?) value isn't one of our keywords, just copy
* the string to the userdir string.
*/
s_cfg->userdir = apr_pstrdup(cmd->pool, arg);
return NULL;
}
/*
* Now we just take each word in turn from the command line and add it to
* the appropriate table.
*/
while (*usernames) {
username = ap_getword_conf(cmd->pool, &usernames);
apr_table_setn(usertable, username, kw);
}
return NULL;
}
static const command_rec userdir_cmds[] = {
AP_INIT_RAW_ARGS("UserDir", set_user_dir, NULL, RSRC_CONF,
"the public subdirectory in users' home directories, or "
"'disabled', or 'disabled username username...', or "
"'enabled username username...'"),
{NULL}
};
static int translate_userdir(request_rec *r)
{
ap_conf_vector_t *server_conf;
const userdir_config *s_cfg;
const char *userdirs;
const char *user, *dname;
char *redirect;
apr_finfo_t statbuf;
/*
* If the URI doesn't match our basic pattern, we've nothing to do with
* it.
*/
if (r->uri[0] != '/' || r->uri[1] != '~') {
return DECLINED;
}
server_conf = r->server->module_config;
s_cfg = ap_get_module_config(server_conf, &userdir_module);
userdirs = s_cfg->userdir;
if (userdirs == NULL) {
return DECLINED;
}
dname = r->uri + 2;
user = ap_getword(r->pool, &dname, '/');
/*
* The 'dname' funny business involves backing it up to capture the '/'
* delimiting the "/~user" part from the rest of the URL, in case there
* was one (the case where there wasn't being just "GET /~user HTTP/1.0",
* for which we don't want to tack on a '/' onto the filename).
*/
if (dname[-1] == '/') {
--dname;
}
/*
* If there's no username, it's not for us. Ignore . and .. as well.
*/
if (user[0] == '\0' ||
(user[1] == '.' && (user[2] == '\0' ||
(user[2] == '.' && user[3] == '\0')))) {
return DECLINED;
}
/*
* Nor if there's an username but it's in the disabled list.
*/
if (apr_table_get(s_cfg->disabled_users, user) != NULL) {
return DECLINED;
}
/*
* If there's a global interdiction on UserDirs, check to see if this
* name is one of the Blessed.
*/
if (s_cfg->globally_disabled == O_DISABLE
&& apr_table_get(s_cfg->enabled_users, user) == NULL) {
return DECLINED;
}
/*
* Special cases all checked, onward to normal substitution processing.
*/
while (*userdirs) {
const char *userdir = ap_getword_conf(r->pool, &userdirs);
char *filename = NULL, *prefix = NULL;
apr_status_t rv;
int is_absolute = ap_os_is_path_absolute(r->pool, userdir);
if (ap_strchr_c(userdir, '*'))
prefix = ap_getword(r->pool, &userdir, '*');
if (userdir[0] == '\0' || is_absolute) {
if (prefix) {
#ifdef HAVE_DRIVE_LETTERS
/*
* Crummy hack. Need to figure out whether we have been
* redirected to a URL or to a file on some drive. Since I
* know of no protocols that are a single letter, ignore
* a : as the first or second character, and assume a file
* was specified
*/
if (strchr(prefix + 2, ':'))
#else
if (strchr(prefix, ':') && !is_absolute)
#endif /* HAVE_DRIVE_LETTERS */
{
redirect = apr_pstrcat(r->pool, prefix, user, userdir,
dname, NULL);
apr_table_setn(r->headers_out, "Location", redirect);
return HTTP_MOVED_TEMPORARILY;
}
else
filename = apr_pstrcat(r->pool, prefix, user, userdir,
NULL);
}
else
filename = apr_pstrcat(r->pool, userdir, "/", user, NULL);
}
else if (prefix && ap_strchr_c(prefix, ':')) {
redirect = apr_pstrcat(r->pool, prefix, user, dname, NULL);
apr_table_setn(r->headers_out, "Location", redirect);
return HTTP_MOVED_TEMPORARILY;
}
else {
#if APR_HAS_USER
char *homedir;
if (apr_uid_homepath_get(&homedir, user, r->pool) == APR_SUCCESS) {
filename = apr_pstrcat(r->pool, homedir, "/", userdir, NULL);
}
#else
return DECLINED;
#endif
}
/*
* Now see if it exists, or we're at the last entry. If we are at the
* last entry, then use the filename generated (if there is one)
* anyway, in the hope that some handler might handle it. This can be
* used, for example, to run a CGI script for the user.
*/
if (filename && (!*userdirs
|| ((rv = apr_stat(&statbuf, filename, APR_FINFO_MIN,
r->pool)) == APR_SUCCESS
|| rv == APR_INCOMPLETE))) {
r->filename = apr_pstrcat(r->pool, filename, dname, NULL);
ap_set_context_info(r, apr_pstrmemdup(r->pool, r->uri,
dname - r->uri),
filename);
/* XXX: Does this walk us around FollowSymLink rules?
* When statbuf contains info on r->filename we can save a syscall
* by copying it to r->finfo
*/
if (*userdirs && dname[0] == 0)
r->finfo = statbuf;
/* For use in the get_suexec_identity phase */
apr_table_setn(r->notes, "mod_userdir_user", user);
return OK;
}
}
return DECLINED;
}
#ifdef HAVE_UNIX_SUEXEC
static ap_unix_identity_t *get_suexec_id_doer(const request_rec *r)
{
ap_unix_identity_t *ugid = NULL;
#if APR_HAS_USER
const char *username = apr_table_get(r->notes, "mod_userdir_user");
if (username == NULL) {
return NULL;
}
if ((ugid = apr_palloc(r->pool, sizeof(*ugid))) == NULL) {
return NULL;
}
if (apr_uid_get(&ugid->uid, &ugid->gid, username, r->pool) != APR_SUCCESS) {
return NULL;
}
ugid->userdir = 1;
#endif
return ugid;
}
#endif /* HAVE_UNIX_SUEXEC */
static void register_hooks(apr_pool_t *p)
{
static const char * const aszPre[]={ "mod_alias.c",NULL };
static const char * const aszSucc[]={ "mod_vhost_alias.c",NULL };
ap_hook_translate_name(translate_userdir,aszPre,aszSucc,APR_HOOK_MIDDLE);
#ifdef HAVE_UNIX_SUEXEC
ap_hook_get_suexec_identity(get_suexec_id_doer,NULL,NULL,APR_HOOK_FIRST);
#endif
}
AP_DECLARE_MODULE(userdir) = {
STANDARD20_MODULE_STUFF,
NULL, /* dir config creater */
NULL, /* dir merger --- default is to override */
create_userdir_config, /* server config */
merge_userdir_config, /* merge server config */
userdir_cmds, /* command apr_table_t */
register_hooks /* register hooks */
};