modules/mappers/mod_alias.c

/* 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.
 */

/*
 * http_alias.c: Stuff for dealing with directory aliases
 *
 * Original by Rob McCool, rewritten in succession by David Robinson
 * and rst.
 *
 */

#include "apr_strings.h"
#include "apr_lib.h"

#define APR_WANT_STRFUNC
#include "apr_want.h"

#include "ap_config.h"
#include "httpd.h"
#include "http_core.h"
#include "http_config.h"
#include "http_request.h"
#include "http_log.h"


typedef struct {
    const char *real;
    const char *fake;
    char *handler;
    ap_regex_t *regexp;
    int redir_status;                /* 301, 302, 303, 410, etc */
} alias_entry;

typedef struct {
    apr_array_header_t *aliases;
    apr_array_header_t *redirects;
} alias_server_conf;

typedef struct {
    apr_array_header_t *redirects;
} alias_dir_conf;

module AP_MODULE_DECLARE_DATA alias_module;

static void *create_alias_config(apr_pool_t *p, server_rec *s)
{
    alias_server_conf *a =
    (alias_server_conf *) apr_pcalloc(p, sizeof(alias_server_conf));

    a->aliases = apr_array_make(p, 20, sizeof(alias_entry));
    a->redirects = apr_array_make(p, 20, sizeof(alias_entry));
    return a;
}

static void *create_alias_dir_config(apr_pool_t *p, char *d)
{
    alias_dir_conf *a =
    (alias_dir_conf *) apr_pcalloc(p, sizeof(alias_dir_conf));
    a->redirects = apr_array_make(p, 2, sizeof(alias_entry));
    return a;
}

static void *merge_alias_config(apr_pool_t *p, void *basev, void *overridesv)
{
    alias_server_conf *a =
    (alias_server_conf *) apr_pcalloc(p, sizeof(alias_server_conf));
    alias_server_conf *base = (alias_server_conf *) basev;
    alias_server_conf *overrides = (alias_server_conf *) overridesv;

    a->aliases = apr_array_append(p, overrides->aliases, base->aliases);
    a->redirects = apr_array_append(p, overrides->redirects, base->redirects);
    return a;
}

static void *merge_alias_dir_config(apr_pool_t *p, void *basev, void *overridesv)
{
    alias_dir_conf *a =
    (alias_dir_conf *) apr_pcalloc(p, sizeof(alias_dir_conf));
    alias_dir_conf *base = (alias_dir_conf *) basev;
    alias_dir_conf *overrides = (alias_dir_conf *) overridesv;
    a->redirects = apr_array_append(p, overrides->redirects, base->redirects);
    return a;
}

/* need prototype for overlap check */
static int alias_matches(const char *uri, const char *alias_fakename);

static const char *add_alias_internal(cmd_parms *cmd, void *dummy,
                                      const char *f, const char *r,
                                      int use_regex)
{
    server_rec *s = cmd->server;
    alias_server_conf *conf = ap_get_module_config(s->module_config,
                                                   &alias_module);
    alias_entry *new = apr_array_push(conf->aliases);
    alias_entry *entries = (alias_entry *)conf->aliases->elts;
    int i;

    /* XX r can NOT be relative to DocumentRoot here... compat bug. */

    if (use_regex) {
        new->regexp = ap_pregcomp(cmd->pool, f, AP_REG_EXTENDED);
        if (new->regexp == NULL)
            return "Regular expression could not be compiled.";
        new->real = r;
    }
    else {
        /* XXX This may be optimized, but we must know that new->real
         * exists.  If so, we can dir merge later, trusing new->real
         * and just canonicalizing the remainder.  Not till I finish
         * cleaning out the old ap_canonical stuff first.
         */
        new->real = r;
    }
    new->fake = f;
    new->handler = cmd->info;

    /* check for overlapping (Script)Alias directives
     * and throw a warning if found one
     */
    if (!use_regex) {
        for (i = 0; i < conf->aliases->nelts - 1; ++i) {
            alias_entry *p = &entries[i];

            if (  (!p->regexp &&  alias_matches(f, p->fake) > 0)
                || (p->regexp && !ap_regexec(p->regexp, f, 0, NULL, 0))) {
                ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server,
                             "The %s directive in %s at line %d will probably "
                             "never match because it overlaps an earlier "
                             "%sAlias%s.",
                             cmd->cmd->name, cmd->directive->filename,
                             cmd->directive->line_num,
                             p->handler ? "Script" : "",
                             p->regexp ? "Match" : "");

                break; /* one warning per alias should be sufficient */
            }
        }
    }

    return NULL;
}

static const char *add_alias(cmd_parms *cmd, void *dummy, const char *f,
                             const char *r)
{
    return add_alias_internal(cmd, dummy, f, r, 0);
}

static const char *add_alias_regex(cmd_parms *cmd, void *dummy, const char *f,
                                   const char *r)
{
    return add_alias_internal(cmd, dummy, f, r, 1);
}

static const char *add_redirect_internal(cmd_parms *cmd,
                                         alias_dir_conf *dirconf,
                                         const char *arg1, const char *arg2,
                                         const char *arg3, int use_regex)
{
    alias_entry *new;
    server_rec *s = cmd->server;
    alias_server_conf *serverconf = ap_get_module_config(s->module_config,
                                                         &alias_module);
    int status = (int) (long) cmd->info;
    int grokarg1 = 1;
=    ap_regex_t *r = NULL;
    const char *f = arg2;
    const char *url = arg3;

    /*
     * Logic flow:
     *   Go ahead and try to grok the 1st arg, in case it is a
     *   Redirect status. Now if we have 3 args, we expect that
     *   we were able to understand that 1st argument (it's something
     *   we expected, so if not, then we bail. We also check that we
     *   don't have a 3rd argument with GONE or with numeric codes
     *   outside of 300-399; if we do, then that's an error.
     */
    if (!strcasecmp(arg1, "permanent"))
        status = HTTP_MOVED_PERMANENTLY;
    else if (!strcasecmp(arg1, "temp"))
        status = HTTP_MOVED_TEMPORARILY;
    else if (!strcasecmp(arg1, "seeother"))
        status = HTTP_SEE_OTHER;
    else if (!strcasecmp(arg1, "gone"))
        status = HTTP_GONE;
    else if (apr_isdigit(*arg1))
        status = atoi(arg1);
    else
        grokarg1 = 0;

    if (arg3 && !grokarg1)
        return "Redirect: invalid first argument (of three)";

    if (arg3 && status == HTTP_GONE)
        return "Redirect: third argument not expected";
        
    if (arg3 && (apr_isdigit(*arg1) && (status < 300 || status > 399)))
        return "Redirect: third argument not expected";
        
    /*
     * if we don't have the 3rd arg and we didn't understand the 1st
     * one, then assume URL-path URL. This also handles case, eg, GONE
     * we even though we don't have a 3rd arg, we did understand the 1st
     * one, so we don't want to re-arrange
     */
    if (!arg3 && !grokarg1) {
        f = arg1;
        url = arg2;
    }

    if (use_regex) {
        r = ap_pregcomp(cmd->pool, f, AP_REG_EXTENDED);
        if (r == NULL)
            return "Regular expression could not be compiled.";
    }

    if (ap_is_HTTP_REDIRECT(status)) {
        if (!url)
            return "URL to redirect to is missing";
        /* PR#35314: we can allow path components here;
         * they get correctly resolved to full URLs.
         */
        if (!use_regex && !ap_is_url(url) && (url[0] != '/'))
            return "Redirect to non-URL";
    }
    else {
        if (url)
            return "Redirect URL not valid for this status";
    }

    if (cmd->path)
        new = apr_array_push(dirconf->redirects);
    else
        new = apr_array_push(serverconf->redirects);

    new->fake = f;
    new->real = url;
    new->regexp = r;
    new->redir_status = status;
    return NULL;
}

static const char *add_redirect(cmd_parms *cmd, void *dirconf,
                                const char *arg1, const char *arg2,
                                const char *arg3)
{
    return add_redirect_internal(cmd, dirconf, arg1, arg2, arg3, 0);
}

static const char *add_redirect2(cmd_parms *cmd, void *dirconf,
                                 const char *arg1, const char *arg2)
{
    return add_redirect_internal(cmd, dirconf, arg1, arg2, NULL, 0);
}

static const char *add_redirect_regex(cmd_parms *cmd, void *dirconf,
                                      const char *arg1, const char *arg2,
                                      const char *arg3)
{
    return add_redirect_internal(cmd, dirconf, arg1, arg2, arg3, 1);
}

static const command_rec alias_cmds[] =
{
    AP_INIT_TAKE2("Alias", add_alias, NULL, RSRC_CONF,
                  "a fakename and a realname"),
    AP_INIT_TAKE2("ScriptAlias", add_alias, "cgi-script", RSRC_CONF,
                  "a fakename and a realname"),
    AP_INIT_TAKE23("Redirect", add_redirect, (void *) HTTP_MOVED_TEMPORARILY,
                   OR_FILEINFO,
                   "an optional status, then document to be redirected and "
                   "destination URL"),
    AP_INIT_TAKE2("AliasMatch", add_alias_regex, NULL, RSRC_CONF,
                  "a regular expression and a filename"),
    AP_INIT_TAKE2("ScriptAliasMatch", add_alias_regex, "cgi-script", RSRC_CONF,
                  "a regular expression and a filename"),
    AP_INIT_TAKE23("RedirectMatch", add_redirect_regex,
                   (void *) HTTP_MOVED_TEMPORARILY, OR_FILEINFO,
                   "an optional status, then a regular expression and "
                   "destination URL"),
    AP_INIT_TAKE2("RedirectTemp", add_redirect2,
                  (void *) HTTP_MOVED_TEMPORARILY, OR_FILEINFO,
                  "a document to be redirected, then the destination URL"),
    AP_INIT_TAKE2("RedirectPermanent", add_redirect2,
                  (void *) HTTP_MOVED_PERMANENTLY, OR_FILEINFO,
                  "a document to be redirected, then the destination URL"),
    {NULL}
};

static int alias_matches(const char *uri, const char *alias_fakename)
{
    const char *aliasp = alias_fakename, *urip = uri;

    while (*aliasp) {
        if (*aliasp == '/') {
            /* any number of '/' in the alias matches any number in
             * the supplied URI, but there must be at least one...
             */
            if (*urip != '/')
                return 0;

            do {
                ++aliasp;
            } while (*aliasp == '/');
            do {
                ++urip;
            } while (*urip == '/');
        }
        else {
            /* Other characters are compared literally */
            if (*urip++ != *aliasp++)
                return 0;
        }
    }

    /* Check last alias path component matched all the way */

    if (aliasp[-1] != '/' && *urip != '\0' && *urip != '/')
        return 0;

    /* Return number of characters from URI which matched (may be
     * greater than length of alias, since we may have matched
     * doubled slashes)
     */

    return urip - uri;
}

static char *try_alias_list(request_rec *r, apr_array_header_t *aliases,
                            int doesc, int *status)
{
    alias_entry *entries = (alias_entry *) aliases->elts;
    ap_regmatch_t regm[AP_MAX_REG_MATCH];
    char *found = NULL;
    int i;

    for (i = 0; i < aliases->nelts; ++i) {
        alias_entry *p = &entries[i];
        int l;

        if (p->regexp) {
            if (!ap_regexec(p->regexp, r->uri, AP_MAX_REG_MATCH, regm, 0)) {
                if (p->real) {
                    found = ap_pregsub(r->pool, p->real, r->uri,
                                       AP_MAX_REG_MATCH, regm);
                    if (found && doesc) {
                        apr_uri_t uri;
                        apr_uri_parse(r->pool, found, &uri);
                        /* Do not escape the query string or fragment. */
                        found = apr_uri_unparse(r->pool, &uri,
                                                APR_URI_UNP_OMITQUERY);
                        found = ap_escape_uri(r->pool, found);
                        if (uri.query) {
                            found = apr_pstrcat(r->pool, found, "?",
                                                uri.query, NULL);
                        }
                        if (uri.fragment) {
                            found = apr_pstrcat(r->pool, found, "#",
                                                uri.fragment, NULL);
                        }
                    }
                }
                else {
                    /* need something non-null */
                    found = apr_pstrdup(r->pool, "");
                }
            }
        }
        else {
            l = alias_matches(r->uri, p->fake);

            if (l > 0) {
                if (doesc) {
                    char *escurl;
                    escurl = ap_os_escape_path(r->pool, r->uri + l, 1);

                    found = apr_pstrcat(r->pool, p->real, escurl, NULL);
                }
                else
                    found = apr_pstrcat(r->pool, p->real, r->uri + l, NULL);
            }
        }

        if (found) {
            if (p->handler) {    /* Set handler, and leave a note for mod_cgi */
                r->handler = p->handler;
                apr_table_setn(r->notes, "alias-forced-type", r->handler);
            }
            /* XXX This is as SLOW as can be, next step, we optimize
             * and merge to whatever part of the found path was already
             * canonicalized.  After I finish eliminating os canonical.
             * Better fail test for ap_server_root_relative needed here.
             */
            if (!doesc) {
                found = ap_server_root_relative(r->pool, found);
            }
            if (found) {
                *status = p->redir_status;
            }
            return found;
        }

    }

    return NULL;
}

static int translate_alias_redir(request_rec *r)
{
    ap_conf_vector_t *sconf = r->server->module_config;
    alias_server_conf *serverconf = ap_get_module_config(sconf, &alias_module);
    char *ret;
    int status;

    if (r->uri[0] != '/' && r->uri[0] != '\0') {
        return DECLINED;
    }

    if ((ret = try_alias_list(r, serverconf->redirects, 1, &status)) != NULL) {
        if (ap_is_HTTP_REDIRECT(status)) {
            /* include QUERY_STRING if any */
            if (r->args) {
                ret = apr_pstrcat(r->pool, ret, "?", r->args, NULL);
            }
            apr_table_setn(r->headers_out, "Location", ret);
        }
        return status;
    }

    if ((ret = try_alias_list(r, serverconf->aliases, 0, &status)) != NULL) {
        r->filename = ret;
        return OK;
    }

    return DECLINED;
}

static int fixup_redir(request_rec *r)
{
    void *dconf = r->per_dir_config;
    alias_dir_conf *dirconf =
    (alias_dir_conf *) ap_get_module_config(dconf, &alias_module);
    char *ret;
    int status;

    /* It may have changed since last time, so try again */

    if ((ret = try_alias_list(r, dirconf->redirects, 1, &status)) != NULL) {
        if (ap_is_HTTP_REDIRECT(status)) {
            if (ret[0] == '/') {
                char *orig_target = ret;

                ret = ap_construct_url(r->pool, ret, r);
                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
                              "incomplete redirection target of '%s' for "
                              "URI '%s' modified to '%s'",
                              orig_target, r->uri, ret);
            }
            if (!ap_is_url(ret)) {
                status = HTTP_INTERNAL_SERVER_ERROR;
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                              "cannot redirect '%s' to '%s'; "
                              "target is not a valid absoluteURI or abs_path",
                              r->uri, ret);
            }
            else {
                /* append requested query only, if the config didn't
                 * supply its own.
                 */
                if (r->args && !ap_strchr(ret, '?')) {
                    ret = apr_pstrcat(r->pool, ret, "?", r->args, NULL);
                }
                apr_table_setn(r->headers_out, "Location", ret);
            }
        }
        return status;
    }

    return DECLINED;
}

static void register_hooks(apr_pool_t *p)
{
    static const char * const aszSucc[]={ "mod_userdir.c",
                                          "mod_vhost_alias.c",NULL };

    ap_hook_translate_name(translate_alias_redir,NULL,aszSucc,APR_HOOK_MIDDLE);
    ap_hook_fixups(fixup_redir,NULL,NULL,APR_HOOK_MIDDLE);
}

module AP_MODULE_DECLARE_DATA alias_module =
{
    STANDARD20_MODULE_STUFF,
    create_alias_dir_config,       /* dir config creater */
    merge_alias_dir_config,        /* dir merger --- default is to override */
    create_alias_config,           /* server config */
    merge_alias_config,            /* merge server configs */
    alias_cmds,                    /* command apr_table_t */
    register_hooks                 /* register hooks */
};
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	* http_alias.c: Stuff for dealing with directory aliases
19	*
20	* Original by Rob McCool, rewritten in succession by David Robinson
21	* and rst.
22	*
23	*/
24
25	#include "apr_strings.h"
26	#include "apr_lib.h"
27
28	#define APR_WANT_STRFUNC
29	#include "apr_want.h"
30
31	#include "ap_config.h"
32	#include "httpd.h"
33	#include "http_core.h"
34	#include "http_config.h"
35	#include "http_request.h"
36	#include "http_log.h"
37
38
39	typedef struct {
40	const char *real;
41	const char *fake;
42	char *handler;
43	ap_regex_t *regexp;
44	int redir_status; /* 301, 302, 303, 410, etc */
45	} alias_entry;
46
47	typedef struct {
48	apr_array_header_t *aliases;
49	apr_array_header_t *redirects;
50	} alias_server_conf;
51
52	typedef struct {
53	apr_array_header_t *redirects;
54	} alias_dir_conf;
55
56	module AP_MODULE_DECLARE_DATA alias_module;
57
58	static void create_alias_config(apr_pool_t p, server_rec *s)
59	{
60	alias_server_conf *a =
61	(alias_server_conf *) apr_pcalloc(p, sizeof(alias_server_conf));
62
63	a->aliases = apr_array_make(p, 20, sizeof(alias_entry));
64	a->redirects = apr_array_make(p, 20, sizeof(alias_entry));
65	return a;
66	}
67
68	static void create_alias_dir_config(apr_pool_t p, char *d)
69	{
70	alias_dir_conf *a =
71	(alias_dir_conf *) apr_pcalloc(p, sizeof(alias_dir_conf));
72	a->redirects = apr_array_make(p, 2, sizeof(alias_entry));
73	return a;
74	}
75
76	static void merge_alias_config(apr_pool_t p, void basev, void overridesv)
77	{
78	alias_server_conf *a =
79	(alias_server_conf *) apr_pcalloc(p, sizeof(alias_server_conf));
80	alias_server_conf base = (alias_server_conf ) basev;
81	alias_server_conf overrides = (alias_server_conf ) overridesv;
82
83	a->aliases = apr_array_append(p, overrides->aliases, base->aliases);
84	a->redirects = apr_array_append(p, overrides->redirects, base->redirects);
85	return a;
86	}
87
88	static void merge_alias_dir_config(apr_pool_t p, void basev, void overridesv)
89	{
90	alias_dir_conf *a =
91	(alias_dir_conf *) apr_pcalloc(p, sizeof(alias_dir_conf));
92	alias_dir_conf base = (alias_dir_conf ) basev;
93	alias_dir_conf overrides = (alias_dir_conf ) overridesv;
94	a->redirects = apr_array_append(p, overrides->redirects, base->redirects);
95	return a;
96	}
97
98	/* need prototype for overlap check */
99	static int alias_matches(const char uri, const char alias_fakename);
100
101	static const char add_alias_internal(cmd_parms cmd, void *dummy,
102	const char f, const char r,
103	int use_regex)
104	{
105	server_rec *s = cmd->server;
106	alias_server_conf *conf = ap_get_module_config(s->module_config,
107	&alias_module);
108	alias_entry *new = apr_array_push(conf->aliases);
109	alias_entry entries = (alias_entry )conf->aliases->elts;
110	int i;
111
112	/* XX r can NOT be relative to DocumentRoot here... compat bug. */
113
114	if (use_regex) {
115	new->regexp = ap_pregcomp(cmd->pool, f, AP_REG_EXTENDED);
116	if (new->regexp == NULL)
117	return "Regular expression could not be compiled.";
118	new->real = r;
119	}
120	else {
121	/* XXX This may be optimized, but we must know that new->real
122	* exists. If so, we can dir merge later, trusing new->real
123	* and just canonicalizing the remainder. Not till I finish
124	* cleaning out the old ap_canonical stuff first.
125	*/
126	new->real = r;
127	}
128	new->fake = f;
129	new->handler = cmd->info;
130
131	/* check for overlapping (Script)Alias directives
132	* and throw a warning if found one
133	*/
134	if (!use_regex) {
135	for (i = 0; i < conf->aliases->nelts - 1; ++i) {
136	alias_entry *p = &entries[i];
137
138	if ( (!p->regexp && alias_matches(f, p->fake) > 0)
139	\|\| (p->regexp && !ap_regexec(p->regexp, f, 0, NULL, 0))) {
140	ap_log_error(APLOG_MARK, APLOG_WARNING, 0, cmd->server,
141	"The %s directive in %s at line %d will probably "
142	"never match because it overlaps an earlier "
143	"%sAlias%s.",
144	cmd->cmd->name, cmd->directive->filename,
145	cmd->directive->line_num,
146	p->handler ? "Script" : "",
147	p->regexp ? "Match" : "");
148
149	break; /* one warning per alias should be sufficient */
150	}
151	}
152	}
153
154	return NULL;
155	}
156
157	static const char add_alias(cmd_parms cmd, void dummy, const char f,
158	const char *r)
159	{
160	return add_alias_internal(cmd, dummy, f, r, 0);
161	}
162
163	static const char add_alias_regex(cmd_parms cmd, void dummy, const char f,
164	const char *r)
165	{
166	return add_alias_internal(cmd, dummy, f, r, 1);
167	}
168
169	static const char add_redirect_internal(cmd_parms cmd,
170	alias_dir_conf *dirconf,
171	const char arg1, const char arg2,
172	const char *arg3, int use_regex)
173	{
174	alias_entry *new;
175	server_rec *s = cmd->server;
176	alias_server_conf *serverconf = ap_get_module_config(s->module_config,
177	&alias_module);
178	int status = (int) (long) cmd->info;
179	int grokarg1 = 1;
180	= ap_regex_t *r = NULL;
181	const char *f = arg2;
182	const char *url = arg3;
183
184	/*
185	* Logic flow:
186	* Go ahead and try to grok the 1st arg, in case it is a
187	* Redirect status. Now if we have 3 args, we expect that
188	* we were able to understand that 1st argument (it's something
189	* we expected, so if not, then we bail. We also check that we
190	* don't have a 3rd argument with GONE or with numeric codes
191	* outside of 300-399; if we do, then that's an error.
192	*/
193	if (!strcasecmp(arg1, "permanent"))
194	status = HTTP_MOVED_PERMANENTLY;
195	else if (!strcasecmp(arg1, "temp"))
196	status = HTTP_MOVED_TEMPORARILY;
197	else if (!strcasecmp(arg1, "seeother"))
198	status = HTTP_SEE_OTHER;
199	else if (!strcasecmp(arg1, "gone"))
200	status = HTTP_GONE;
201	else if (apr_isdigit(*arg1))
202	status = atoi(arg1);
203	else
204	grokarg1 = 0;
205
206	if (arg3 && !grokarg1)
207	return "Redirect: invalid first argument (of three)";
208
209	if (arg3 && status == HTTP_GONE)
210	return "Redirect: third argument not expected";
211
212	if (arg3 && (apr_isdigit(*arg1) && (status < 300 \|\| status > 399)))
213	return "Redirect: third argument not expected";
214
215	/*
216	* if we don't have the 3rd arg and we didn't understand the 1st
217	* one, then assume URL-path URL. This also handles case, eg, GONE
218	* we even though we don't have a 3rd arg, we did understand the 1st
219	* one, so we don't want to re-arrange
220	*/
221	if (!arg3 && !grokarg1) {
222	f = arg1;
223	url = arg2;
224	}
225
226	if (use_regex) {
227	r = ap_pregcomp(cmd->pool, f, AP_REG_EXTENDED);
228	if (r == NULL)
229	return "Regular expression could not be compiled.";
230	}
231
232	if (ap_is_HTTP_REDIRECT(status)) {
233	if (!url)
234	return "URL to redirect to is missing";
235	/* PR#35314: we can allow path components here;
236	* they get correctly resolved to full URLs.
237	*/
238	if (!use_regex && !ap_is_url(url) && (url[0] != '/'))
239	return "Redirect to non-URL";
240	}
241	else {
242	if (url)
243	return "Redirect URL not valid for this status";
244	}
245
246	if (cmd->path)
247	new = apr_array_push(dirconf->redirects);
248	else
249	new = apr_array_push(serverconf->redirects);
250
251	new->fake = f;
252	new->real = url;
253	new->regexp = r;
254	new->redir_status = status;
255	return NULL;
256	}
257
258	static const char add_redirect(cmd_parms cmd, void *dirconf,
259	const char arg1, const char arg2,
260	const char *arg3)
261	{
262	return add_redirect_internal(cmd, dirconf, arg1, arg2, arg3, 0);
263	}
264
265	static const char add_redirect2(cmd_parms cmd, void *dirconf,
266	const char arg1, const char arg2)
267	{
268	return add_redirect_internal(cmd, dirconf, arg1, arg2, NULL, 0);
269	}
270
271	static const char add_redirect_regex(cmd_parms cmd, void *dirconf,
272	const char arg1, const char arg2,
273	const char *arg3)
274	{
275	return add_redirect_internal(cmd, dirconf, arg1, arg2, arg3, 1);
276	}
277
278	static const command_rec alias_cmds[] =
279	{
280	AP_INIT_TAKE2("Alias", add_alias, NULL, RSRC_CONF,
281	"a fakename and a realname"),
282	AP_INIT_TAKE2("ScriptAlias", add_alias, "cgi-script", RSRC_CONF,
283	"a fakename and a realname"),
284	AP_INIT_TAKE23("Redirect", add_redirect, (void *) HTTP_MOVED_TEMPORARILY,
285	OR_FILEINFO,
286	"an optional status, then document to be redirected and "
287	"destination URL"),
288	AP_INIT_TAKE2("AliasMatch", add_alias_regex, NULL, RSRC_CONF,
289	"a regular expression and a filename"),
290	AP_INIT_TAKE2("ScriptAliasMatch", add_alias_regex, "cgi-script", RSRC_CONF,
291	"a regular expression and a filename"),
292	AP_INIT_TAKE23("RedirectMatch", add_redirect_regex,
293	(void *) HTTP_MOVED_TEMPORARILY, OR_FILEINFO,
294	"an optional status, then a regular expression and "
295	"destination URL"),
296	AP_INIT_TAKE2("RedirectTemp", add_redirect2,
297	(void *) HTTP_MOVED_TEMPORARILY, OR_FILEINFO,
298	"a document to be redirected, then the destination URL"),
299	AP_INIT_TAKE2("RedirectPermanent", add_redirect2,
300	(void *) HTTP_MOVED_PERMANENTLY, OR_FILEINFO,
301	"a document to be redirected, then the destination URL"),
302	{NULL}
303	};
304
305	static int alias_matches(const char uri, const char alias_fakename)
306	{
307	const char aliasp = alias_fakename, urip = uri;
308
309	while (*aliasp) {
310	if (*aliasp == '/') {
311	/* any number of '/' in the alias matches any number in
312	* the supplied URI, but there must be at least one...
313	*/
314	if (*urip != '/')
315	return 0;
316
317	do {
318	++aliasp;
319	} while (*aliasp == '/');
320	do {
321	++urip;
322	} while (*urip == '/');
323	}
324	else {
325	/* Other characters are compared literally */
326	if (urip++ != aliasp++)
327	return 0;
328	}
329	}
330
331	/* Check last alias path component matched all the way */
332
333	if (aliasp[-1] != '/' && urip != '\0' && urip != '/')
334	return 0;
335
336	/* Return number of characters from URI which matched (may be
337	* greater than length of alias, since we may have matched
338	* doubled slashes)
339	*/
340
341	return urip - uri;
342	}
343
344	static char try_alias_list(request_rec r, apr_array_header_t *aliases,
345	int doesc, int *status)
346	{
347	alias_entry entries = (alias_entry ) aliases->elts;
348	ap_regmatch_t regm[AP_MAX_REG_MATCH];
349	char *found = NULL;
350	int i;
351
352	for (i = 0; i < aliases->nelts; ++i) {
353	alias_entry *p = &entries[i];
354	int l;
355
356	if (p->regexp) {
357	if (!ap_regexec(p->regexp, r->uri, AP_MAX_REG_MATCH, regm, 0)) {
358	if (p->real) {
359	found = ap_pregsub(r->pool, p->real, r->uri,
360	AP_MAX_REG_MATCH, regm);
361	if (found && doesc) {
362	apr_uri_t uri;
363	apr_uri_parse(r->pool, found, &uri);
364	/* Do not escape the query string or fragment. */
365	found = apr_uri_unparse(r->pool, &uri,
366	APR_URI_UNP_OMITQUERY);
367	found = ap_escape_uri(r->pool, found);
368	if (uri.query) {
369	found = apr_pstrcat(r->pool, found, "?",
370	uri.query, NULL);
371	}
372	if (uri.fragment) {
373	found = apr_pstrcat(r->pool, found, "#",
374	uri.fragment, NULL);
375	}
376	}
377	}
378	else {
379	/* need something non-null */
380	found = apr_pstrdup(r->pool, "");
381	}
382	}
383	}
384	else {
385	l = alias_matches(r->uri, p->fake);
386
387	if (l > 0) {
388	if (doesc) {
389	char *escurl;
390	escurl = ap_os_escape_path(r->pool, r->uri + l, 1);
391
392	found = apr_pstrcat(r->pool, p->real, escurl, NULL);
393	}
394	else
395	found = apr_pstrcat(r->pool, p->real, r->uri + l, NULL);
396	}
397	}
398
399	if (found) {
400	if (p->handler) { /* Set handler, and leave a note for mod_cgi */
401	r->handler = p->handler;
402	apr_table_setn(r->notes, "alias-forced-type", r->handler);
403	}
404	/* XXX This is as SLOW as can be, next step, we optimize
405	* and merge to whatever part of the found path was already
406	* canonicalized. After I finish eliminating os canonical.
407	* Better fail test for ap_server_root_relative needed here.
408	*/
409	if (!doesc) {
410	found = ap_server_root_relative(r->pool, found);
411	}
412	if (found) {
413	*status = p->redir_status;
414	}
415	return found;
416	}
417
418	}
419
420	return NULL;
421	}
422
423	static int translate_alias_redir(request_rec *r)
424	{
425	ap_conf_vector_t *sconf = r->server->module_config;
426	alias_server_conf *serverconf = ap_get_module_config(sconf, &alias_module);
427	char *ret;
428	int status;
429
430	if (r->uri[0] != '/' && r->uri[0] != '\0') {
431	return DECLINED;
432	}
433
434	if ((ret = try_alias_list(r, serverconf->redirects, 1, &status)) != NULL) {
435	if (ap_is_HTTP_REDIRECT(status)) {
436	/* include QUERY_STRING if any */
437	if (r->args) {
438	ret = apr_pstrcat(r->pool, ret, "?", r->args, NULL);
439	}
440	apr_table_setn(r->headers_out, "Location", ret);
441	}
442	return status;
443	}
444
445	if ((ret = try_alias_list(r, serverconf->aliases, 0, &status)) != NULL) {
446	r->filename = ret;
447	return OK;
448	}
449
450	return DECLINED;
451	}
452
453	static int fixup_redir(request_rec *r)
454	{
455	void *dconf = r->per_dir_config;
456	alias_dir_conf *dirconf =
457	(alias_dir_conf *) ap_get_module_config(dconf, &alias_module);
458	char *ret;
459	int status;
460
461	/* It may have changed since last time, so try again */
462
463	if ((ret = try_alias_list(r, dirconf->redirects, 1, &status)) != NULL) {
464	if (ap_is_HTTP_REDIRECT(status)) {
465	if (ret[0] == '/') {
466	char *orig_target = ret;
467
468	ret = ap_construct_url(r->pool, ret, r);
469	ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
470	"incomplete redirection target of '%s' for "
471	"URI '%s' modified to '%s'",
472	orig_target, r->uri, ret);
473	}
474	if (!ap_is_url(ret)) {
475	status = HTTP_INTERNAL_SERVER_ERROR;
476	ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
477	"cannot redirect '%s' to '%s'; "
478	"target is not a valid absoluteURI or abs_path",
479	r->uri, ret);
480	}
481	else {
482	/* append requested query only, if the config didn't
483	* supply its own.
484	*/
485	if (r->args && !ap_strchr(ret, '?')) {
486	ret = apr_pstrcat(r->pool, ret, "?", r->args, NULL);
487	}
488	apr_table_setn(r->headers_out, "Location", ret);
489	}
490	}
491	return status;
492	}
493
494	return DECLINED;
495	}
496
497	static void register_hooks(apr_pool_t *p)
498	{
499	static const char * const aszSucc[]={ "mod_userdir.c",
500	"mod_vhost_alias.c",NULL };
501
502	ap_hook_translate_name(translate_alias_redir,NULL,aszSucc,APR_HOOK_MIDDLE);
503	ap_hook_fixups(fixup_redir,NULL,NULL,APR_HOOK_MIDDLE);
504	}
505
506	module AP_MODULE_DECLARE_DATA alias_module =
507	{
508	STANDARD20_MODULE_STUFF,
509	create_alias_dir_config, /* dir config creater */
510	merge_alias_dir_config, /* dir merger --- default is to override */
511	create_alias_config, /* server config */
512	merge_alias_config, /* merge server configs */
513	alias_cmds, /* command apr_table_t */
514	register_hooks /* register hooks */
515	};