From 5488d212438e21dd06b38c885f239e4af5da1d1f Mon Sep 17 00:00:00 2001 From: Graham Leggett Date: Thu, 22 Jan 2015 17:02:22 +0000 Subject: [PATCH] mod_alias: Introduce expression parser support for Alias, ScriptAlias and Redirect. git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1653941 13f79535-47bb-0310-9956-ffa450edef68 --- CHANGES | 3 + docs/manual/expr.xml | 3 + docs/manual/mod/mod_alias.xml | 84 +++++++++++++- modules/mappers/mod_alias.c | 212 ++++++++++++++++++++++++++++++++-- 4 files changed, 284 insertions(+), 18 deletions(-) diff --git a/CHANGES b/CHANGES index 9f4d736349..efe67fa85b 100644 --- a/CHANGES +++ b/CHANGES @@ -1,6 +1,9 @@ -*- coding: utf-8 -*- Changes with Apache 2.5.0 + *) mod_alias: Introduce expression parser support for Alias, ScriptAlias + and Redirect. [Graham Leggett] + *) mod_ssl: 'SSLProtocol ALL' was being ignored in virtual host context. PR 57100. [Michael Kaufmann ] diff --git a/docs/manual/expr.xml b/docs/manual/expr.xml index 308624da9b..44e35eaee9 100644 --- a/docs/manual/expr.xml +++ b/docs/manual/expr.xml @@ -40,6 +40,9 @@ If ElseIf Else +Alias +ScriptAlias +Redirect AuthBasicFake AuthFormLoginRequiredLocation AuthFormLoginSuccessLocation diff --git a/docs/manual/mod/mod_alias.xml b/docs/manual/mod/mod_alias.xml index 53088cba4d..7dc569d738 100644 --- a/docs/manual/mod/mod_alias.xml +++ b/docs/manual/mod/mod_alias.xml @@ -47,6 +47,15 @@ a different URL. They are often used when a resource has moved to a new location.

+

When the Alias, + ScriptAlias and + Redirect directives are used + within a Location + or LocationMatch + section, expression syntax can be used + to manipulate the destination path or URL. +

+

mod_alias is designed to handle simple URL manipulation tasks. For more complicated tasks such as manipulating the query string, use the tools provided by @@ -90,14 +99,25 @@ Alias /foo /gaq module="mod_alias">Alias, so the latter directive would be ignored.

+

When the Alias, + ScriptAlias and + Redirect directives are used + within a Location + or LocationMatch + section, these directives will take precedence over any globally + defined Alias, + ScriptAlias and + Redirect directives.

+ Alias Maps URLs to filesystem locations -Alias URL-path +Alias [URL-path] file-path|directory-path server configvirtual host +directory @@ -158,6 +178,21 @@ Alias /image /ftp/pub/image

Any number slashes in the URL-path parameter matches any number of slashes in the requested URL-path.

+

If the Alias directive is used within a + Location + or LocationMatch + section the URL-path is omitted, and the file-path is interpreted + using expression syntax.

+ + +<Location /image> + Alias /ftp/pub/image +</Location> +<LocationMatch /error/(?<NUMBER>[0-9]+)> + Alias /usr/local/apache/errors/%{env:MATCH_NUMBER}.html +</LocationMatch> + + @@ -256,7 +291,7 @@ expressions Redirect Sends an external redirect asking the client to fetch a different URL -Redirect [status] URL-path +Redirect [status] [URL-path] URL server configvirtual host directory.htaccess @@ -297,15 +332,18 @@ Redirect /one /two Note that POSTs will be discarded.
Only complete path segments are matched, so the above example would not match a request for - http://example.com/servicefoo.txt. For more complex matching - using regular expressions, see the http://example.com/servicefoo.txt. For more complex matching + using the expression syntax, omit the URL-path + argument as described below. Alternatively, for matching using regular + expressions, see the RedirectMatch directive.

Note

Redirect directives take precedence over Alias and ScriptAlias directives, irrespective of their ordering in the configuration - file.

 + file. Redirect directives inside a Location take precedence over + Redirect and Alias directives with an URL-path.

If no status argument is given, the redirect will be "temporary" (HTTP status 302). This indicates to the client @@ -348,6 +386,24 @@ Redirect permanent /one http://example.com/two Redirect 303 /three http://example.com/other +

If the Redirect directive is used within a + Location + or LocationMatch + section with the URL-path omitted, then the URL parameter will be + interpreted using expression syntax.

+ + +<Location /one> + Redirect permanent http://example.com/two +</Location>
+<Location /three> + Redirect 303 http://example.com/other +</Location>
+<LocationMatch /error/(?<NUMBER>[0-9]+)> + Redirect permanent http://example.com/errors/%{env:MATCH_NUMBER}.html +</LocationMatch>
+ + @@ -425,9 +481,10 @@ a different URL ScriptAlias Maps a URL to a filesystem location and designates the target as a CGI script -ScriptAlias URL-path +ScriptAlias [URL-path] file-path|directory-path server configvirtual host +directory @@ -491,6 +548,21 @@ Alias /cgi-bin/ /web/cgi-bin/ of the CGI scripts if they are not restricted by a Directory section. +

If the ScriptAlias directive is used within + a Location + or LocationMatch + section with the URL-path omitted, then the URL parameter will be + interpreted using expression syntax.

+ + +<Location /cgi-bin > + ScriptAlias /web/cgi-bin/ +</Location> +<LocationMatch /cgi-bin/errors/(?<NUMBER>[0-9]+)> + ScriptAlias /web/cgi-bin/errors/%{env:MATCH_NUMBER}.cgi +</LocationMatch>
+ + CGI Tutorial diff --git a/modules/mappers/mod_alias.c b/modules/mappers/mod_alias.c index dfba13320e..1e8a5b41bf 100644 --- a/modules/mappers/mod_alias.c +++ b/modules/mappers/mod_alias.c @@ -34,6 +34,7 @@ #include "http_config.h" #include "http_request.h" #include "http_log.h" +#include "ap_expr.h" typedef struct { @@ -50,11 +51,20 @@ typedef struct { } alias_server_conf; typedef struct { + int alias_set:1; + int redirect_set:1; apr_array_header_t *redirects; + const ap_expr_info_t *alias; + char *handler; + const ap_expr_info_t *redirect; + int redirect_status; /* 301, 302, 303, 410, etc */ } alias_dir_conf; module AP_MODULE_DECLARE_DATA alias_module; +static char magic_error_value; +#define PREGSUB_ERROR (&magic_error_value) + static void *create_alias_config(apr_pool_t *p, server_rec *s) { alias_server_conf *a = @@ -91,7 +101,17 @@ static void *merge_alias_dir_config(apr_pool_t *p, void *basev, void *overridesv (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); + + a->alias = (overrides->alias_set == 0) ? base->alias : overrides->alias; + a->handler = (overrides->alias_set == 0) ? base->handler : overrides->handler; + a->alias_set = overrides->alias_set || base->alias_set; + + a->redirect = (overrides->redirect_set == 0) ? base->redirect : overrides->redirect; + a->redirect_status = (overrides->redirect_set == 0) ? base->redirect_status : overrides->redirect_status; + a->redirect_set = overrides->redirect_set || base->redirect_set; + return a; } @@ -111,6 +131,12 @@ static const char *add_alias_internal(cmd_parms *cmd, void *dummy, /* XXX: real can NOT be relative to DocumentRoot here... compat bug. */ + const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE); + + if (err != NULL) { + return err; + } + if (use_regex) { new->regexp = ap_pregcomp(cmd->pool, fake, AP_REG_EXTENDED); if (new->regexp == NULL) @@ -155,9 +181,41 @@ static const char *add_alias_internal(cmd_parms *cmd, void *dummy, } static const char *add_alias(cmd_parms *cmd, void *dummy, const char *fake, - const char *real) + const char *real) { - return add_alias_internal(cmd, dummy, fake, real, 0); + if (real) { + + return add_alias_internal(cmd, dummy, fake, real, 0); + + } + else { + alias_dir_conf *dirconf = (alias_dir_conf *) dummy; + + const char *err = ap_check_cmd_context(cmd, NOT_IN_DIRECTORY|NOT_IN_FILES); + + if (err != NULL) { + return err; + } + + if (!cmd->path) { + return "Alias must have two arguments when used globally"; + } + + dirconf->alias = + ap_expr_parse_cmd(cmd, fake, AP_EXPR_FLAG_STRING_RESULT, + &err, NULL); + if (err) { + return apr_pstrcat(cmd->temp_pool, + "Cannot parse alias expression '", fake, "': ", err, + NULL); + } + + dirconf->handler = cmd->info; + dirconf->alias_set = 1; + + return NULL; + + } } static const char *add_alias_regex(cmd_parms *cmd, void *dummy, @@ -204,6 +262,59 @@ static const char *add_redirect_internal(cmd_parms *cmd, if (arg3 && !grokarg1) return "Redirect: invalid first argument (of three)"; + /* + * if we have the 2nd arg and we understand the 1st one, or if we have the + * 1st arg but don't understand it, we use the expression syntax assuming + * a path from the location. + * + * if we understand the first arg but have no second arg, we are dealing + * with a status like "GONE". + */ + if (grokarg1 && arg2 && !arg3 && HTTP_GONE != status) { + const char *expr_err = NULL; + + dirconf->redirect = + ap_expr_parse_cmd(cmd, arg2, AP_EXPR_FLAG_STRING_RESULT, + &expr_err, NULL); + if (expr_err) { + return apr_pstrcat(cmd->temp_pool, + "Cannot parse redirect expression '", arg2, "': ", expr_err, + NULL); + } + + dirconf->redirect_status = status; + dirconf->redirect_set = 1; + + return NULL; + + } + else if (grokarg1 && !arg2 && HTTP_GONE == status) { + + dirconf->redirect_status = status; + dirconf->redirect_set = 1; + + return NULL; + + } + else if (!grokarg1 && !arg2) { + const char *expr_err = NULL; + + dirconf->redirect = + ap_expr_parse_cmd(cmd, arg1, AP_EXPR_FLAG_STRING_RESULT, + &expr_err, NULL); + if (expr_err) { + return apr_pstrcat(cmd->temp_pool, + "Cannot parse redirect expression '", arg1, "': ", expr_err, + NULL); + } + + dirconf->redirect_status = status; + dirconf->redirect_set = 1; + + return NULL; + + } + /* * 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 @@ -269,11 +380,11 @@ static const char *add_redirect_regex(cmd_parms *cmd, void *dirconf, 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, + AP_INIT_TAKE12("Alias", add_alias, NULL, RSRC_CONF | ACCESS_CONF, + "a fakename and a realname, or a realname in a Location"), + AP_INIT_TAKE12("ScriptAlias", add_alias, "cgi-script", RSRC_CONF | ACCESS_CONF, + "a fakename and a realname, or a realname in a Location"), + AP_INIT_TAKE123("Redirect", add_redirect, (void *) HTTP_MOVED_TEMPORARILY, OR_FILEINFO, "an optional status, then document to be redirected and " "destination URL"), @@ -333,8 +444,79 @@ static int alias_matches(const char *uri, const char *alias_fakename) return urip - uri; } -static char magic_error_value; -#define PREGSUB_ERROR (&magic_error_value) +static char *try_alias(request_rec *r) +{ + alias_dir_conf *dirconf = + (alias_dir_conf *) ap_get_module_config(r->per_dir_config, &alias_module); + + if (dirconf->alias) { + const char *err = NULL; + + char *found = apr_pstrdup(r->pool, + ap_expr_str_exec(r, dirconf->alias, &err)); + if (err) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO() + "Can't evaluate alias expression: %s", err); + return PREGSUB_ERROR; + } + + if (dirconf->handler) { /* Set handler, and leave a note for mod_cgi */ + r->handler = dirconf->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. + */ + found = ap_server_root_relative(r->pool, found); + return found; + + } + + return NULL; +} + +static char *try_redirect(request_rec *r, int *status) +{ + alias_dir_conf *dirconf = + (alias_dir_conf *) ap_get_module_config(r->per_dir_config, &alias_module); + + if (dirconf->redirect_set) { + apr_uri_t uri; + const char *err = NULL; + char *found = ""; + + if (dirconf->redirect) { + + found = apr_pstrdup(r->pool, + ap_expr_str_exec(r, dirconf->redirect, &err)); + if (err) { + ap_log_rerror( + APLOG_MARK, APLOG_ERR, 0, r, APLOGNO() "Can't evaluate redirect expression: %s", err); + return PREGSUB_ERROR; + } + + 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); + } + + } + + *status = dirconf->redirect_status; + return found; + + } + + return NULL; +} static char *try_alias_list(request_rec *r, apr_array_header_t *aliases, int is_redir, int *status) @@ -435,7 +617,9 @@ static int translate_alias_redir(request_rec *r) return DECLINED; } - if ((ret = try_alias_list(r, serverconf->redirects, 1, &status)) != NULL) { + if ((ret = try_redirect(r, &status)) != NULL + || (ret = try_alias_list(r, serverconf->redirects, 1, &status)) + != NULL) { if (ret == PREGSUB_ERROR) return HTTP_INTERNAL_SERVER_ERROR; if (ap_is_HTTP_REDIRECT(status)) { @@ -468,7 +652,9 @@ static int translate_alias_redir(request_rec *r) return status; } - if ((ret = try_alias_list(r, serverconf->aliases, 0, &status)) != NULL) { + if ((ret = try_alias(r)) != NULL + || (ret = try_alias_list(r, serverconf->aliases, 0, &status)) + != NULL) { r->filename = ret; return OK; } @@ -486,7 +672,9 @@ static int fixup_redir(request_rec *r) /* It may have changed since last time, so try again */ - if ((ret = try_alias_list(r, dirconf->redirects, 1, &status)) != NULL) { + if ((ret = try_redirect(r, &status)) != NULL + || (ret = try_alias_list(r, dirconf->redirects, 1, &status)) + != NULL) { if (ret == PREGSUB_ERROR) return HTTP_INTERNAL_SERVER_ERROR; if (ap_is_HTTP_REDIRECT(status)) { -- 2.40.0