File httpd-2.2.x-bnc777260-CVE-2012-2687-mod_negotiation_filename_xss.diff of Package apache2.1524
diff -rNU 20 ../httpd-2.2.21-o/modules/mappers/mod_negotiation.c ./modules/mappers/mod_negotiation.c
--- ../httpd-2.2.21-o/modules/mappers/mod_negotiation.c 2011-09-08 17:59:38.000000000 +0200
+++ ./modules/mappers/mod_negotiation.c 2013-01-28 14:28:03.000000000 +0100
@@ -2641,43 +2641,43 @@
* fill it with the variant list, and then concatenate the entire array.
*/
arr = apr_array_make(r->pool, max_vlist_array, sizeof(char *));
*((const char **) apr_array_push(arr)) = "Available variants:\n<ul>\n";
for (i = 0; i < neg->avail_vars->nelts; ++i) {
var_rec *variant = &((var_rec *) neg->avail_vars->elts)[i];
const char *filename = variant->file_name ? variant->file_name : "";
apr_array_header_t *languages = variant->content_languages;
const char *description = variant->description
? variant->description
: "";
/* The format isn't very neat, and it would be nice to make
* the tags human readable (eg replace 'language en' with 'English').
* Note that if you change the number of substrings pushed, you also
* need to change the calculation of max_vlist_array above.
*/
*((const char **) apr_array_push(arr)) = "<li><a href=\"";
- *((const char **) apr_array_push(arr)) = filename;
+ *((const char **) apr_array_push(arr)) = ap_escape_path_segment(r->pool, filename);
*((const char **) apr_array_push(arr)) = "\">";
- *((const char **) apr_array_push(arr)) = filename;
+ *((const char **) apr_array_push(arr)) = ap_escape_html(r->pool, filename);
*((const char **) apr_array_push(arr)) = "</a> ";
*((const char **) apr_array_push(arr)) = description;
if (variant->mime_type && *variant->mime_type) {
*((const char **) apr_array_push(arr)) = ", type ";
*((const char **) apr_array_push(arr)) = variant->mime_type;
}
if (languages && languages->nelts) {
*((const char **) apr_array_push(arr)) = ", language ";
*((const char **) apr_array_push(arr)) = apr_array_pstrcat(r->pool,
languages, ',');
}
if (variant->content_charset && *variant->content_charset) {
*((const char **) apr_array_push(arr)) = ", charset ";
*((const char **) apr_array_push(arr)) = variant->content_charset;
}
if (variant->content_encoding) {
*((const char **) apr_array_push(arr)) = ", encoding ";
*((const char **) apr_array_push(arr)) = variant->content_encoding;
}
diff -rNU 20 ../httpd-2.2.21-o/modules/mappers/mod_negotiation.c.orig ./modules/mappers/mod_negotiation.c.orig
--- ../httpd-2.2.21-o/modules/mappers/mod_negotiation.c.orig 1970-01-01 01:00:00.000000000 +0100
+++ ./modules/mappers/mod_negotiation.c.orig 2011-09-08 17:59:38.000000000 +0200
@@ -0,0 +1,3236 @@
+/* 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_negotiation.c: keeps track of MIME types the client is willing to
+ * accept, and contains code to handle type arbitration.
+ *
+ * rst
+ */
+
+#include "apr.h"
+#include "apr_strings.h"
+#include "apr_file_io.h"
+#include "apr_lib.h"
+
+#define APR_WANT_STRFUNC
+#include "apr_want.h"
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_request.h"
+#include "http_protocol.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "util_script.h"
+
+
+#define MAP_FILE_MAGIC_TYPE "application/x-type-map"
+
+/* Commands --- configuring document caching on a per (virtual?)
+ * server basis...
+ */
+
+typedef struct {
+ int forcelangpriority;
+ apr_array_header_t *language_priority;
+} neg_dir_config;
+
+/* forcelangpriority flags
+ */
+#define FLP_UNDEF 0 /* Same as FLP_DEFAULT, but base overrides */
+#define FLP_NONE 1 /* Return 406, HTTP_NOT_ACCEPTABLE */
+#define FLP_PREFER 2 /* Use language_priority rather than MC */
+#define FLP_FALLBACK 4 /* Use language_priority rather than NA */
+
+#define FLP_DEFAULT FLP_PREFER
+
+/* env evaluation
+ */
+#define DISCARD_ALL_ENCODINGS 1 /* no-gzip */
+#define DISCARD_ALL_BUT_HTML 2 /* gzip-only-text/html */
+
+module AP_MODULE_DECLARE_DATA negotiation_module;
+
+static void *create_neg_dir_config(apr_pool_t *p, char *dummy)
+{
+ neg_dir_config *new = (neg_dir_config *) apr_palloc(p,
+ sizeof(neg_dir_config));
+
+ new->forcelangpriority = FLP_UNDEF;
+ new->language_priority = NULL;
+ return new;
+}
+
+static void *merge_neg_dir_configs(apr_pool_t *p, void *basev, void *addv)
+{
+ neg_dir_config *base = (neg_dir_config *) basev;
+ neg_dir_config *add = (neg_dir_config *) addv;
+ neg_dir_config *new = (neg_dir_config *) apr_palloc(p,
+ sizeof(neg_dir_config));
+
+ /* give priority to the config in the subdirectory */
+ new->forcelangpriority = (add->forcelangpriority != FLP_UNDEF)
+ ? add->forcelangpriority
+ : base->forcelangpriority;
+ new->language_priority = add->language_priority
+ ? add->language_priority
+ : base->language_priority;
+ return new;
+}
+
+static const char *set_language_priority(cmd_parms *cmd, void *n_,
+ const char *lang)
+{
+ neg_dir_config *n = n_;
+ const char **langp;
+
+ if (!n->language_priority)
+ n->language_priority = apr_array_make(cmd->pool, 4, sizeof(char *));
+
+ langp = (const char **) apr_array_push(n->language_priority);
+ *langp = lang;
+ return NULL;
+}
+
+static const char *set_force_priority(cmd_parms *cmd, void *n_, const char *w)
+{
+ neg_dir_config *n = n_;
+
+ if (!strcasecmp(w, "None")) {
+ if (n->forcelangpriority & ~FLP_NONE) {
+ return "Cannot combine ForceLanguagePriority options with None";
+ }
+ n->forcelangpriority = FLP_NONE;
+ }
+ else if (!strcasecmp(w, "Prefer")) {
+ if (n->forcelangpriority & FLP_NONE) {
+ return "Cannot combine ForceLanguagePriority options None and "
+ "Prefer";
+ }
+ n->forcelangpriority |= FLP_PREFER;
+ }
+ else if (!strcasecmp(w, "Fallback")) {
+ if (n->forcelangpriority & FLP_NONE) {
+ return "Cannot combine ForceLanguagePriority options None and "
+ "Fallback";
+ }
+ n->forcelangpriority |= FLP_FALLBACK;
+ }
+ else {
+ return apr_pstrcat(cmd->pool, "Invalid ForceLanguagePriority option ",
+ w, NULL);
+ }
+
+ return NULL;
+}
+
+static const char *cache_negotiated_docs(cmd_parms *cmd, void *dummy,
+ int arg)
+{
+ ap_set_module_config(cmd->server->module_config, &negotiation_module,
+ (arg ? "Cache" : NULL));
+ return NULL;
+}
+
+static int do_cache_negotiated_docs(server_rec *s)
+{
+ return (ap_get_module_config(s->module_config,
+ &negotiation_module) != NULL);
+}
+
+static const command_rec negotiation_cmds[] =
+{
+ AP_INIT_FLAG("CacheNegotiatedDocs", cache_negotiated_docs, NULL, RSRC_CONF,
+ "Either 'on' or 'off' (default)"),
+ AP_INIT_ITERATE("LanguagePriority", set_language_priority, NULL,
+ OR_FILEINFO,
+ "space-delimited list of MIME language abbreviations"),
+ AP_INIT_ITERATE("ForceLanguagePriority", set_force_priority, NULL,
+ OR_FILEINFO,
+ "Force LanguagePriority elections, either None, or "
+ "Fallback and/or Prefer"),
+ {NULL}
+};
+
+/*
+ * Record of available info on a media type specified by the client
+ * (we also use 'em for encodings and languages)
+ */
+
+typedef struct accept_rec {
+ char *name; /* MUST be lowercase */
+ float quality;
+ float level;
+ char *charset; /* for content-type only */
+} accept_rec;
+
+/*
+ * Record of available info on a particular variant
+ *
+ * Note that a few of these fields are updated by the actual negotiation
+ * code. These are:
+ *
+ * level_matched --- initialized to zero. Set to the value of level
+ * if the client actually accepts this media type at that
+ * level (and *not* if it got in on a wildcard). See level_cmp
+ * below.
+ * mime_stars -- initialized to zero. Set to the number of stars
+ * present in the best matching Accept header element.
+ * 1 for star/star, 2 for type/star and 3 for
+ * type/subtype.
+ *
+ * definite -- initialized to 1. Set to 0 if there is a match which
+ * makes the variant non-definite according to the rules
+ * in rfc2296.
+ */
+
+typedef struct var_rec {
+ request_rec *sub_req; /* May be NULL (is, for map files) */
+ const char *mime_type; /* MUST be lowercase */
+ const char *file_name; /* Set to 'this' (for map file body content) */
+ apr_off_t body; /* Only for map file body content */
+ const char *content_encoding;
+ apr_array_header_t *content_languages; /* list of lang. for this variant */
+ const char *content_charset;
+ const char *description;
+
+ /* The next five items give the quality values for the dimensions
+ * of negotiation for this variant. They are obtained from the
+ * appropriate header lines, except for source_quality, which
+ * is obtained from the variant itself (the 'qs' parameter value
+ * from the variant's mime-type). Apart from source_quality,
+ * these values are set when we find the quality for each variant
+ * (see best_match()). source_quality is set from the 'qs' parameter
+ * of the variant description or mime type: see set_mime_fields().
+ */
+ float lang_quality; /* quality of this variant's language */
+ float encoding_quality; /* ditto encoding */
+ float charset_quality; /* ditto charset */
+ float mime_type_quality; /* ditto media type */
+ float source_quality; /* source quality for this variant */
+
+ /* Now some special values */
+ float level; /* Auxiliary to content-type... */
+ apr_off_t bytes; /* content length, if known */
+ int lang_index; /* Index into LanguagePriority list */
+ int is_pseudo_html; /* text/html, *or* the INCLUDES_MAGIC_TYPEs */
+
+ /* Above are all written-once properties of the variant. The
+ * three fields below are changed during negotiation:
+ */
+
+ float level_matched;
+ int mime_stars;
+ int definite;
+} var_rec;
+
+/* Something to carry around the state of negotiation (and to keep
+ * all of this thread-safe)...
+ */
+
+typedef struct {
+ apr_pool_t *pool;
+ request_rec *r;
+ neg_dir_config *conf;
+ char *dir_name;
+ int accept_q; /* 1 if an Accept item has a q= param */
+ float default_lang_quality; /* fiddle lang q for variants with no lang */
+
+ /* the array pointers below are NULL if the corresponding accept
+ * headers are not present
+ */
+ apr_array_header_t *accepts; /* accept_recs */
+ apr_array_header_t *accept_encodings; /* accept_recs */
+ apr_array_header_t *accept_charsets; /* accept_recs */
+ apr_array_header_t *accept_langs; /* accept_recs */
+
+ apr_array_header_t *avail_vars; /* available variants */
+
+ int count_multiviews_variants; /* number of variants found on disk */
+
+ int is_transparent; /* 1 if this resource is trans. negotiable */
+
+ int dont_fiddle_headers; /* 1 if we may not fiddle with accept hdrs */
+ int ua_supports_trans; /* 1 if ua supports trans negotiation */
+ int send_alternates; /* 1 if we want to send an Alternates header */
+ int may_choose; /* 1 if we may choose a variant for the client */
+ int use_rvsa; /* 1 if we must use RVSA/1.0 negotiation algo */
+} negotiation_state;
+
+/* A few functions to manipulate var_recs.
+ * Cleaning out the fields...
+ */
+
+static void clean_var_rec(var_rec *mime_info)
+{
+ mime_info->sub_req = NULL;
+ mime_info->mime_type = "";
+ mime_info->file_name = "";
+ mime_info->body = 0;
+ mime_info->content_encoding = NULL;
+ mime_info->content_languages = NULL;
+ mime_info->content_charset = "";
+ mime_info->description = "";
+
+ mime_info->is_pseudo_html = 0;
+ mime_info->level = 0.0f;
+ mime_info->level_matched = 0.0f;
+ mime_info->bytes = -1;
+ mime_info->lang_index = -1;
+ mime_info->mime_stars = 0;
+ mime_info->definite = 1;
+
+ mime_info->charset_quality = 1.0f;
+ mime_info->encoding_quality = 1.0f;
+ mime_info->lang_quality = 1.0f;
+ mime_info->mime_type_quality = 1.0f;
+ mime_info->source_quality = 0.0f;
+}
+
+/* Initializing the relevant fields of a variant record from the
+ * accept_info read out of its content-type, one way or another.
+ */
+
+static void set_mime_fields(var_rec *var, accept_rec *mime_info)
+{
+ var->mime_type = mime_info->name;
+ var->source_quality = mime_info->quality;
+ var->level = mime_info->level;
+ var->content_charset = mime_info->charset;
+
+ var->is_pseudo_html = (!strcmp(var->mime_type, "text/html")
+ || !strcmp(var->mime_type, INCLUDES_MAGIC_TYPE)
+ || !strcmp(var->mime_type, INCLUDES_MAGIC_TYPE3));
+}
+
+/* Create a variant list validator in r using info from vlistr. */
+
+static void set_vlist_validator(request_rec *r, request_rec *vlistr)
+{
+ /* Calculating the variant list validator is similar to
+ * calculating an etag for the source of the variant list
+ * information, so we use ap_make_etag(). Note that this
+ * validator can be 'weak' in extreme case.
+ */
+ ap_update_mtime(vlistr, vlistr->finfo.mtime);
+ r->vlist_validator = ap_make_etag(vlistr, 0);
+
+ /* ap_set_etag will later take r->vlist_validator into account
+ * when creating the etag header
+ */
+}
+
+
+/*****************************************************************
+ *
+ * Parsing (lists of) media types and their parameters, as seen in
+ * HTTPD header lines and elsewhere.
+ */
+
+/*
+ * parse quality value. atof(3) is not well-usable here, because it
+ * depends on the locale (argh).
+ *
+ * However, RFC 2616 states:
+ * 3.9 Quality Values
+ *
+ * [...] HTTP/1.1 applications MUST NOT generate more than three digits
+ * after the decimal point. User configuration of these values SHOULD also
+ * be limited in this fashion.
+ *
+ * qvalue = ( "0" [ "." 0*3DIGIT ] )
+ * | ( "1" [ "." 0*3("0") ] )
+ *
+ * This is quite easy. If the supplied string doesn't match the above
+ * definition (loosely), we simply return 1 (same as if there's no qvalue)
+ */
+
+static float atoq(const char *string)
+{
+ if (!string || !*string) {
+ return 1.0f;
+ }
+
+ while (*string && apr_isspace(*string)) {
+ ++string;
+ }
+
+ /* be tolerant and accept qvalues without leading zero
+ * (also for backwards compat, where atof() was in use)
+ */
+ if (*string != '.' && *string++ != '0') {
+ return 1.0f;
+ }
+
+ if (*string == '.') {
+ /* better only one division later, than dealing with fscking
+ * IEEE format 0.1 factors ...
+ */
+ int i = 0;
+
+ if (*++string >= '0' && *string <= '9') {
+ i += (*string - '0') * 100;
+
+ if (*++string >= '0' && *string <= '9') {
+ i += (*string - '0') * 10;
+
+ if (*++string > '0' && *string <= '9') {
+ i += (*string - '0');
+ }
+ }
+ }
+
+ return (float)i / 1000.0f;
+ }
+
+ return 0.0f;
+}
+
+/*
+ * Get a single mime type entry --- one media type and parameters;
+ * enter the values we recognize into the argument accept_rec
+ */
+
+static const char *get_entry(apr_pool_t *p, accept_rec *result,
+ const char *accept_line)
+{
+ result->quality = 1.0f;
+ result->level = 0.0f;
+ result->charset = "";
+
+ /*
+ * Note that this handles what I gather is the "old format",
+ *
+ * Accept: text/html text/plain moo/zot
+ *
+ * without any compatibility kludges --- if the token after the
+ * MIME type begins with a semicolon, we know we're looking at parms,
+ * otherwise, we know we aren't. (So why all the pissing and moaning
+ * in the CERN server code? I must be missing something).
+ */
+
+ result->name = ap_get_token(p, &accept_line, 0);
+ ap_str_tolower(result->name); /* You want case insensitive,
+ * you'll *get* case insensitive.
+ */
+
+ /* KLUDGE!!! Default HTML to level 2.0 unless the browser
+ * *explicitly* says something else.
+ */
+
+ if (!strcmp(result->name, "text/html") && (result->level == 0.0)) {
+ result->level = 2.0f;
+ }
+ else if (!strcmp(result->name, INCLUDES_MAGIC_TYPE)) {
+ result->level = 2.0f;
+ }
+ else if (!strcmp(result->name, INCLUDES_MAGIC_TYPE3)) {
+ result->level = 3.0f;
+ }
+
+ while (*accept_line == ';') {
+ /* Parameters ... */
+
+ char *parm;
+ char *cp;
+ char *end;
+
+ ++accept_line;
+ parm = ap_get_token(p, &accept_line, 1);
+
+ /* Look for 'var = value' --- and make sure the var is in lcase. */
+
+ for (cp = parm; (*cp && !apr_isspace(*cp) && *cp != '='); ++cp) {
+ *cp = apr_tolower(*cp);
+ }
+
+ if (!*cp) {
+ continue; /* No '='; just ignore it. */
+ }
+
+ *cp++ = '\0'; /* Delimit var */
+ while (*cp && (apr_isspace(*cp) || *cp == '=')) {
+ ++cp;
+ }
+
+ if (*cp == '"') {
+ ++cp;
+ for (end = cp;
+ (*end && *end != '\n' && *end != '\r' && *end != '\"');
+ end++);
+ }
+ else {
+ for (end = cp; (*end && !apr_isspace(*end)); end++);
+ }
+ if (*end) {
+ *end = '\0'; /* strip ending quote or return */
+ }
+ ap_str_tolower(cp);
+
+ if (parm[0] == 'q'
+ && (parm[1] == '\0' || (parm[1] == 's' && parm[2] == '\0'))) {
+ result->quality = atoq(cp);
+ }
+ else if (parm[0] == 'l' && !strcmp(&parm[1], "evel")) {
+ result->level = (float)atoi(cp);
+ }
+ else if (!strcmp(parm, "charset")) {
+ result->charset = cp;
+ }
+ }
+
+ if (*accept_line == ',') {
+ ++accept_line;
+ }
+
+ return accept_line;
+}
+
+/*****************************************************************
+ *
+ * Dealing with header lines ...
+ *
+ * Accept, Accept-Charset, Accept-Language and Accept-Encoding
+ * are handled by do_header_line() - they all have the same
+ * basic structure of a list of items of the format
+ * name; q=N; charset=TEXT
+ *
+ * where charset is only valid in Accept.
+ */
+
+static apr_array_header_t *do_header_line(apr_pool_t *p,
+ const char *accept_line)
+{
+ apr_array_header_t *accept_recs;
+
+ if (!accept_line) {
+ return NULL;
+ }
+
+ accept_recs = apr_array_make(p, 40, sizeof(accept_rec));
+
+ while (*accept_line) {
+ accept_rec *new = (accept_rec *) apr_array_push(accept_recs);
+ accept_line = get_entry(p, new, accept_line);
+ }
+
+ return accept_recs;
+}
+
+/* Given the text of the Content-Languages: line from the var map file,
+ * return an array containing the languages of this variant
+ */
+
+static apr_array_header_t *do_languages_line(apr_pool_t *p,
+ const char **lang_line)
+{
+ apr_array_header_t *lang_recs = apr_array_make(p, 2, sizeof(char *));
+
+ if (!lang_line) {
+ return lang_recs;
+ }
+
+ while (**lang_line) {
+ char **new = (char **) apr_array_push(lang_recs);
+ *new = ap_get_token(p, lang_line, 0);
+ ap_str_tolower(*new);
+ if (**lang_line == ',' || **lang_line == ';') {
+ ++(*lang_line);
+ }
+ }
+
+ return lang_recs;
+}
+
+/*****************************************************************
+ *
+ * Handling header lines from clients...
+ */
+
+static negotiation_state *parse_accept_headers(request_rec *r)
+{
+ negotiation_state *new =
+ (negotiation_state *) apr_pcalloc(r->pool, sizeof(negotiation_state));
+ accept_rec *elts;
+ apr_table_t *hdrs = r->headers_in;
+ int i;
+
+ new->pool = r->pool;
+ new->r = r;
+ new->conf = (neg_dir_config *)ap_get_module_config(r->per_dir_config,
+ &negotiation_module);
+
+ new->dir_name = ap_make_dirstr_parent(r->pool, r->filename);
+
+ new->accepts = do_header_line(r->pool, apr_table_get(hdrs, "Accept"));
+
+ /* calculate new->accept_q value */
+ if (new->accepts) {
+ elts = (accept_rec *) new->accepts->elts;
+
+ for (i = 0; i < new->accepts->nelts; ++i) {
+ if (elts[i].quality < 1.0) {
+ new->accept_q = 1;
+ }
+ }
+ }
+
+ new->accept_encodings =
+ do_header_line(r->pool, apr_table_get(hdrs, "Accept-Encoding"));
+ new->accept_langs =
+ do_header_line(r->pool, apr_table_get(hdrs, "Accept-Language"));
+ new->accept_charsets =
+ do_header_line(r->pool, apr_table_get(hdrs, "Accept-Charset"));
+
+ /* This is possibly overkill for some servers, heck, we have
+ * only 33 index.html variants in docs/docroot (today).
+ * Make this configurable?
+ */
+ new->avail_vars = apr_array_make(r->pool, 40, sizeof(var_rec));
+
+ return new;
+}
+
+
+static void parse_negotiate_header(request_rec *r, negotiation_state *neg)
+{
+ const char *negotiate = apr_table_get(r->headers_in, "Negotiate");
+ char *tok;
+
+ /* First, default to no TCN, no Alternates, and the original Apache
+ * negotiation algorithm with fiddles for broken browser configs.
+ *
+ * To save network bandwidth, we do not configure to send an
+ * Alternates header to the user agent by default. User
+ * agents that want an Alternates header for agent-driven
+ * negotiation will have to request it by sending an
+ * appropriate Negotiate header.
+ */
+ neg->ua_supports_trans = 0;
+ neg->send_alternates = 0;
+ neg->may_choose = 1;
+ neg->use_rvsa = 0;
+ neg->dont_fiddle_headers = 0;
+
+ if (!negotiate)
+ return;
+
+ if (strcmp(negotiate, "trans") == 0) {
+ /* Lynx 2.7 and 2.8 send 'negotiate: trans' even though they
+ * do not support transparent content negotiation, so for Lynx we
+ * ignore the negotiate header when its contents are exactly "trans".
+ * If future versions of Lynx ever need to say 'negotiate: trans',
+ * they can send the equivalent 'negotiate: trans, trans' instead
+ * to avoid triggering the workaround below.
+ */
+ const char *ua = apr_table_get(r->headers_in, "User-Agent");
+
+ if (ua && (strncmp(ua, "Lynx", 4) == 0))
+ return;
+ }
+
+ neg->may_choose = 0; /* An empty Negotiate would require 300 response */
+
+ while ((tok = ap_get_list_item(neg->pool, &negotiate)) != NULL) {
+
+ if (strcmp(tok, "trans") == 0 ||
+ strcmp(tok, "vlist") == 0 ||
+ strcmp(tok, "guess-small") == 0 ||
+ apr_isdigit(tok[0]) ||
+ strcmp(tok, "*") == 0) {
+
+ /* The user agent supports transparent negotiation */
+ neg->ua_supports_trans = 1;
+
+ /* Send-alternates could be configurable, but note
+ * that it must be 1 if we have 'vlist' in the
+ * negotiate header.
+ */
+ neg->send_alternates = 1;
+
+ if (strcmp(tok, "1.0") == 0) {
+ /* we may use the RVSA/1.0 algorithm, configure for it */
+ neg->may_choose = 1;
+ neg->use_rvsa = 1;
+ neg->dont_fiddle_headers = 1;
+ }
+ else if (tok[0] == '*') {
+ /* we may use any variant selection algorithm, configure
+ * to use the Apache algorithm
+ */
+ neg->may_choose = 1;
+
+ /* We disable header fiddles on the assumption that a
+ * client sending Negotiate knows how to send correct
+ * headers which don't need fiddling.
+ */
+ neg->dont_fiddle_headers = 1;
+ }
+ }
+ }
+
+#ifdef NEG_DEBUG
+ ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
+ "dont_fiddle_headers=%d use_rvsa=%d ua_supports_trans=%d "
+ "send_alternates=%d, may_choose=%d",
+ neg->dont_fiddle_headers, neg->use_rvsa,
+ neg->ua_supports_trans, neg->send_alternates, neg->may_choose);
+#endif
+
+}
+
+/* Sometimes clients will give us no Accept info at all; this routine sets
+ * up the standard default for that case, and also arranges for us to be
+ * willing to run a CGI script if we find one. (In fact, we set up to
+ * dramatically prefer CGI scripts in cases where that's appropriate,
+ * e.g., POST or when URI includes query args or extra path info).
+ */
+static void maybe_add_default_accepts(negotiation_state *neg,
+ int prefer_scripts)
+{
+ accept_rec *new_accept;
+
+ if (!neg->accepts) {
+ neg->accepts = apr_array_make(neg->pool, 4, sizeof(accept_rec));
+
+ new_accept = (accept_rec *) apr_array_push(neg->accepts);
+
+ new_accept->name = "*/*";
+ new_accept->quality = 1.0f;
+ new_accept->level = 0.0f;
+ }
+
+ new_accept = (accept_rec *) apr_array_push(neg->accepts);
+
+ new_accept->name = CGI_MAGIC_TYPE;
+ if (neg->use_rvsa) {
+ new_accept->quality = 0;
+ }
+ else {
+ new_accept->quality = prefer_scripts ? 2.0f : 0.001f;
+ }
+ new_accept->level = 0.0f;
+}
+
+/*****************************************************************
+ *
+ * Parsing type-map files, in Roy's meta/http format augmented with
+ * #-comments.
+ */
+
+/* Reading RFC822-style header lines, ignoring #-comments and
+ * handling continuations.
+ */
+
+enum header_state {
+ header_eof, header_seen, header_sep
+};
+
+static enum header_state get_header_line(char *buffer, int len, apr_file_t *map)
+{
+ char *buf_end = buffer + len;
+ char *cp;
+ char c;
+
+ /* Get a noncommented line */
+
+ do {
+ if (apr_file_gets(buffer, MAX_STRING_LEN, map) != APR_SUCCESS) {
+ return header_eof;
+ }
+ } while (buffer[0] == '#');
+
+ /* If blank, just return it --- this ends information on this variant */
+
+ for (cp = buffer; (*cp && apr_isspace(*cp)); ++cp) {
+ continue;
+ }
+
+ if (*cp == '\0') {
+ return header_sep;
+ }
+
+ /* If non-blank, go looking for header lines, but note that we still
+ * have to treat comments specially...
+ */
+
+ cp += strlen(cp);
+
+ /* We need to shortcut the rest of this block following the Body:
+ * tag - we will not look for continutation after this line.
+ */
+ if (!strncasecmp(buffer, "Body:", 5))
+ return header_seen;
+
+ while (apr_file_getc(&c, map) != APR_EOF) {
+ if (c == '#') {
+ /* Comment line */
+ while (apr_file_getc(&c, map) != APR_EOF && c != '\n') {
+ continue;
+ }
+ }
+ else if (apr_isspace(c)) {
+ /* Leading whitespace. POSSIBLE continuation line
+ * Also, possibly blank --- if so, we ungetc() the final newline
+ * so that we will pick up the blank line the next time 'round.
+ */
+
+ while (c != '\n' && apr_isspace(c)) {
+ if(apr_file_getc(&c, map) != APR_SUCCESS)
+ break;
+ }
+
+ apr_file_ungetc(c, map);
+
+ if (c == '\n') {
+ return header_seen; /* Blank line */
+ }
+
+ /* Continuation */
+
+ while ( cp < buf_end - 2
+ && (apr_file_getc(&c, map)) != APR_EOF
+ && c != '\n') {
+ *cp++ = c;
+ }
+
+ *cp++ = '\n';
+ *cp = '\0';
+ }
+ else {
+
+ /* Line beginning with something other than whitespace */
+
+ apr_file_ungetc(c, map);
+ return header_seen;
+ }
+ }
+
+ return header_seen;
+}
+
+static apr_off_t get_body(char *buffer, apr_size_t *len, const char *tag,
+ apr_file_t *map)
+{
+ char *endbody;
+ int bodylen;
+ int taglen;
+ apr_off_t pos;
+
+ taglen = strlen(tag);
+ *len -= taglen;
+
+ /* We are at the first character following a body:tag\n entry
+ * Suck in the body, then backspace to the first char after the
+ * closing tag entry. If we fail to read, find the tag or back
+ * up then we have a hosed file, so give up already
+ */
+ if (apr_file_read(map, buffer, len) != APR_SUCCESS) {
+ return -1;
+ }
+
+ /* put a copy of the tag *after* the data read from the file
+ * so that strstr() will find something with no reliance on
+ * terminating '\0'
+ */
+ memcpy(buffer + *len, tag, taglen);
+ endbody = strstr(buffer, tag);
+ if (endbody == buffer + *len) {
+ return -1;
+ }
+ bodylen = endbody - buffer;
+ endbody += taglen;
+ /* Skip all the trailing cruft after the end tag to the next line */
+ while (*endbody) {
+ if (*endbody == '\n') {
+ ++endbody;
+ break;
+ }
+ ++endbody;
+ }
+
+ pos = -(apr_off_t)(*len - (endbody - buffer));
+ if (apr_file_seek(map, APR_CUR, &pos) != APR_SUCCESS) {
+ return -1;
+ }
+
+ /* Give the caller back the actual body's file offset and length */
+ *len = bodylen;
+ return pos - (endbody - buffer);
+}
+
+
+/* Stripping out RFC822 comments */
+
+static void strip_paren_comments(char *hdr)
+{
+ /* Hmmm... is this correct? In Roy's latest draft, (comments) can nest! */
+ /* Nope, it isn't correct. Fails to handle backslash escape as well. */
+
+ while (*hdr) {
+ if (*hdr == '"') {
+ hdr = strchr(hdr, '"');
+ if (hdr == NULL) {
+ return;
+ }
+ ++hdr;
+ }
+ else if (*hdr == '(') {
+ while (*hdr && *hdr != ')') {
+ *hdr++ = ' ';
+ }
+
+ if (*hdr) {
+ *hdr++ = ' ';
+ }
+ }
+ else {
+ ++hdr;
+ }
+ }
+}
+
+/* Getting to a header body from the header */
+
+static char *lcase_header_name_return_body(char *header, request_rec *r)
+{
+ char *cp = header;
+
+ for ( ; *cp && *cp != ':' ; ++cp) {
+ *cp = apr_tolower(*cp);
+ }
+
+ if (!*cp) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+ "Syntax error in type map, no ':' in %s for header %s",
+ r->filename, header);
+ return NULL;
+ }
+
+ do {
+ ++cp;
+ } while (*cp && apr_isspace(*cp));
+
+ if (!*cp) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+ "Syntax error in type map --- no header body: %s for %s",
+ r->filename, header);
+ return NULL;
+ }
+
+ return cp;
+}
+
+static int read_type_map(apr_file_t **map, negotiation_state *neg,
+ request_rec *rr)
+{
+ request_rec *r = neg->r;
+ apr_file_t *map_ = NULL;
+ apr_status_t status;
+ char buffer[MAX_STRING_LEN];
+ enum header_state hstate;
+ struct var_rec mime_info;
+ int has_content;
+
+ if (!map)
+ map = &map_;
+
+ /* We are not using multiviews */
+ neg->count_multiviews_variants = 0;
+
+ if ((status = apr_file_open(map, rr->filename, APR_READ | APR_BUFFERED,
+ APR_OS_DEFAULT, neg->pool)) != APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r,
+ "cannot access type map file: %s", rr->filename);
+ if (APR_STATUS_IS_ENOTDIR(status) || APR_STATUS_IS_ENOENT(status)) {
+ return HTTP_NOT_FOUND;
+ }
+ else {
+ return HTTP_FORBIDDEN;
+ }
+ }
+
+ clean_var_rec(&mime_info);
+ has_content = 0;
+
+ do {
+ hstate = get_header_line(buffer, MAX_STRING_LEN, *map);
+
+ if (hstate == header_seen) {
+ char *body1 = lcase_header_name_return_body(buffer, neg->r);
+ const char *body;
+
+ if (body1 == NULL) {
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+
+ strip_paren_comments(body1);
+ body = body1;
+
+ if (!strncmp(buffer, "uri:", 4)) {
+ mime_info.file_name = ap_get_token(neg->pool, &body, 0);
+ }
+ else if (!strncmp(buffer, "content-type:", 13)) {
+ struct accept_rec accept_info;
+
+ get_entry(neg->pool, &accept_info, body);
+ set_mime_fields(&mime_info, &accept_info);
+ has_content = 1;
+ }
+ else if (!strncmp(buffer, "content-length:", 15)) {
+ char *errp;
+ apr_off_t number;
+
+ if (apr_strtoff(&number, body, &errp, 10)
+ || *errp || number < 0) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+ "Parse error in type map, Content-Length: "
+ "'%s' in %s is invalid.",
+ body, r->filename);
+ break;
+ }
+ mime_info.bytes = number;
+ has_content = 1;
+ }
+ else if (!strncmp(buffer, "content-language:", 17)) {
+ mime_info.content_languages = do_languages_line(neg->pool,
+ &body);
+ has_content = 1;
+ }
+ else if (!strncmp(buffer, "content-encoding:", 17)) {
+ mime_info.content_encoding = ap_get_token(neg->pool, &body, 0);
+ has_content = 1;
+ }
+ else if (!strncmp(buffer, "description:", 12)) {
+ char *desc = apr_pstrdup(neg->pool, body);
+ char *cp;
+
+ for (cp = desc; *cp; ++cp) {
+ if (*cp=='\n') *cp=' ';
+ }
+ if (cp>desc) *(cp-1)=0;
+ mime_info.description = desc;
+ }
+ else if (!strncmp(buffer, "body:", 5)) {
+ char *tag = apr_pstrdup(neg->pool, body);
+ char *eol = strchr(tag, '\0');
+ apr_size_t len = MAX_STRING_LEN;
+ while (--eol >= tag && apr_isspace(*eol))
+ *eol = '\0';
+ if ((mime_info.body = get_body(buffer, &len, tag, *map)) < 0) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+ "Syntax error in type map, no end tag '%s'"
+ "found in %s for Body: content.",
+ tag, r->filename);
+ break;
+ }
+ mime_info.bytes = len;
+ mime_info.file_name = apr_filepath_name_get(rr->filename);
+ }
+ }
+ else {
+ if (*mime_info.file_name && has_content) {
+ void *new_var = apr_array_push(neg->avail_vars);
+
+ memcpy(new_var, (void *) &mime_info, sizeof(var_rec));
+ }
+
+ clean_var_rec(&mime_info);
+ has_content = 0;
+ }
+ } while (hstate != header_eof);
+
+ if (map_)
+ apr_file_close(map_);
+
+ set_vlist_validator(r, rr);
+
+ return OK;
+}
+
+
+/* Sort function used by read_types_multi. */
+static int variantsortf(var_rec *a, var_rec *b) {
+
+ /* First key is the source quality, sort in descending order. */
+
+ /* XXX: note that we currently implement no method of setting the
+ * source quality for multiviews variants, so we are always comparing
+ * 1.0 to 1.0 for now
+ */
+ if (a->source_quality < b->source_quality)
+ return 1;
+ if (a->source_quality > b->source_quality)
+ return -1;
+
+ /* Second key is the variant name */
+ return strcmp(a->file_name, b->file_name);
+}
+
+/*****************************************************************
+ *
+ * Same as read_type_map, except we use a filtered directory listing
+ * as the map...
+ */
+
+static int read_types_multi(negotiation_state *neg)
+{
+ request_rec *r = neg->r;
+
+ char *filp;
+ int prefix_len;
+ apr_dir_t *dirp;
+ apr_finfo_t dirent;
+ apr_status_t status;
+ struct var_rec mime_info;
+ struct accept_rec accept_info;
+ void *new_var;
+ int anymatch = 0;
+
+ clean_var_rec(&mime_info);
+
+ if (r->proxyreq || !r->filename
+ || !ap_os_is_path_absolute(neg->pool, r->filename)) {
+ return DECLINED;
+ }
+
+ /* Only absolute paths here */
+ if (!(filp = strrchr(r->filename, '/'))) {
+ return DECLINED;
+ }
+ ++filp;
+ prefix_len = strlen(filp);
+
+ if ((status = apr_dir_open(&dirp, neg->dir_name,
+ neg->pool)) != APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r,
+ "cannot read directory for multi: %s", neg->dir_name);
+ return HTTP_FORBIDDEN;
+ }
+
+ while (apr_dir_read(&dirent, APR_FINFO_DIRENT, dirp) == APR_SUCCESS) {
+ apr_array_header_t *exception_list;
+ request_rec *sub_req;
+
+ /* Do we have a match? */
+#ifdef CASE_BLIND_FILESYSTEM
+ if (strncasecmp(dirent.name, filp, prefix_len)) {
+#else
+ if (strncmp(dirent.name, filp, prefix_len)) {
+#endif
+ continue;
+ }
+ if (dirent.name[prefix_len] != '.') {
+ continue;
+ }
+
+ /* Don't negotiate directories and other unusual files
+ * Really shouldn't see anything but DIR/LNK/REG here,
+ * and we aught to discover if the LNK was interesting.
+ *
+ * Of course, this only helps platforms that capture the
+ * the filetype in apr_dir_read(), which most can once
+ * they are optimized with some magic [it's known to the
+ * dirent, not associated to the inode, on most FS's.]
+ */
+ if ((dirent.valid & APR_FINFO_TYPE) && (dirent.filetype == APR_DIR))
+ continue;
+
+ /* Ok, something's here. Maybe nothing useful. Remember that
+ * we tried, if we completely fail, so we can reject the request!
+ */
+ anymatch = 1;
+
+ /* See if it's something which we have access to, and which
+ * has a known type and encoding (as opposed to something
+ * which we'll be slapping default_type on later).
+ */
+ sub_req = ap_sub_req_lookup_dirent(&dirent, r, AP_SUBREQ_MERGE_ARGS,
+ NULL);
+
+ /* Double check, we still don't multi-resolve non-ordinary files
+ */
+ if (sub_req->finfo.filetype != APR_REG) {
+ /* XXX sub req not destroyed -- may be a bug/unintentional ? */
+ continue;
+ }
+
+ /* If it has a handler, we'll pretend it's a CGI script,
+ * since that's a good indication of the sort of thing it
+ * might be doing.
+ */
+ if (sub_req->handler && !sub_req->content_type) {
+ ap_set_content_type(sub_req, CGI_MAGIC_TYPE);
+ }
+
+ /*
+ * mod_mime will _always_ provide us the base name in the
+ * ap-mime-exception-list, if it processed anything. If
+ * this list is empty, give up immediately, there was
+ * nothing interesting. For example, looking at the files
+ * readme.txt and readme.foo, we will throw away .foo if
+ * it's an insignificant file (e.g. did not identify a
+ * language, charset, encoding, content type or handler,)
+ */
+ exception_list =
+ (apr_array_header_t *)apr_table_get(sub_req->notes,
+ "ap-mime-exceptions-list");
+
+ if (!exception_list) {
+ ap_destroy_sub_req(sub_req);
+ continue;
+ }
+
+ /* Each unregonized bit better match our base name, in sequence.
+ * A test of index.html.foo will match index.foo or index.html.foo,
+ * but it will never transpose the segments and allow index.foo.html
+ * because that would introduce too much CPU consumption. Better that
+ * we don't attempt a many-to-many match here.
+ */
+ {
+ int nexcept = exception_list->nelts;
+ char **cur_except = (char**)exception_list->elts;
+ char *segstart = filp, *segend, saveend;
+
+ while (*segstart && nexcept) {
+ if (!(segend = strchr(segstart, '.')))
+ segend = strchr(segstart, '\0');
+ saveend = *segend;
+ *segend = '\0';
+
+#ifdef CASE_BLIND_FILESYSTEM
+ if (strcasecmp(segstart, *cur_except) == 0) {
+#else
+ if (strcmp(segstart, *cur_except) == 0) {
+#endif
+ --nexcept;
+ ++cur_except;
+ }
+
+ if (!saveend)
+ break;
+
+ *segend = saveend;
+ segstart = segend + 1;
+ }
+
+ if (nexcept) {
+ /* Something you don't know is, something you don't know...
+ */
+ ap_destroy_sub_req(sub_req);
+ continue;
+ }
+ }
+
+ /*
+ * ###: be warned, the _default_ content type is already
+ * picked up here! If we failed the subrequest, or don't
+ * know what we are serving, then continue.
+ */
+ if (sub_req->status != HTTP_OK || (!sub_req->content_type)) {
+ ap_destroy_sub_req(sub_req);
+ continue;
+ }
+
+ /* If it's a map file, we use that instead of the map
+ * we're building...
+ */
+ if (((sub_req->content_type) &&
+ !strcmp(sub_req->content_type, MAP_FILE_MAGIC_TYPE)) ||
+ ((sub_req->handler) &&
+ !strcmp(sub_req->handler, "type-map"))) {
+
+ apr_dir_close(dirp);
+ neg->avail_vars->nelts = 0;
+ if (sub_req->status != HTTP_OK) {
+ return sub_req->status;
+ }
+ return read_type_map(NULL, neg, sub_req);
+ }
+
+ /* Have reasonable variant --- gather notes. */
+
+ mime_info.sub_req = sub_req;
+ mime_info.file_name = apr_pstrdup(neg->pool, dirent.name);
+ if (sub_req->content_encoding) {
+ mime_info.content_encoding = sub_req->content_encoding;
+ }
+ if (sub_req->content_languages) {
+ mime_info.content_languages = sub_req->content_languages;
+ }
+
+ get_entry(neg->pool, &accept_info, sub_req->content_type);
+ set_mime_fields(&mime_info, &accept_info);
+
+ new_var = apr_array_push(neg->avail_vars);
+ memcpy(new_var, (void *) &mime_info, sizeof(var_rec));
+
+ neg->count_multiviews_variants++;
+
+ clean_var_rec(&mime_info);
+ }
+
+ apr_dir_close(dirp);
+
+ /* We found some file names that matched. None could be served.
+ * Rather than fall out to autoindex or some other mapper, this
+ * request must die.
+ */
+ if (anymatch && !neg->avail_vars->nelts) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+ "Negotiation: discovered file(s) matching request: %s"
+ " (None could be negotiated).",
+ r->filename);
+ return HTTP_NOT_FOUND;
+ }
+
+ set_vlist_validator(r, r);
+
+ /* Sort the variants into a canonical order. The negotiation
+ * result sometimes depends on the order of the variants. By
+ * sorting the variants into a canonical order, rather than using
+ * the order in which readdir() happens to return them, we ensure
+ * that the negotiation result will be consistent over filesystem
+ * backup/restores and over all mirror sites.
+ */
+
+ qsort((void *) neg->avail_vars->elts, neg->avail_vars->nelts,
+ sizeof(var_rec), (int (*)(const void *, const void *)) variantsortf);
+
+ return OK;
+}
+
+
+/*****************************************************************
+ * And now for the code you've been waiting for... actually
+ * finding a match to the client's requirements.
+ */
+
+/* Matching MIME types ... the star/star and foo/star commenting conventions
+ * are implemented here. (You know what I mean by star/star, but just
+ * try mentioning those three characters in a C comment). Using strcmp()
+ * is legit, because everything has already been smashed to lowercase.
+ *
+ * Note also that if we get an exact match on the media type, we update
+ * level_matched for use in level_cmp below...
+ *
+ * We also give a value for mime_stars, which is used later. It should
+ * be 1 for star/star, 2 for type/star and 3 for type/subtype.
+ */
+
+static int mime_match(accept_rec *accept_r, var_rec *avail)
+{
+ const char *accept_type = accept_r->name;
+ const char *avail_type = avail->mime_type;
+ int len = strlen(accept_type);
+
+ if (accept_type[0] == '*') { /* Anything matches star/star */
+ if (avail->mime_stars < 1) {
+ avail->mime_stars = 1;
+ }
+ return 1;
+ }
+ else if ((accept_type[len - 1] == '*') &&
+ !strncmp(accept_type, avail_type, len - 2)) {
+ if (avail->mime_stars < 2) {
+ avail->mime_stars = 2;
+ }
+ return 1;
+ }
+ else if (!strcmp(accept_type, avail_type)
+ || (!strcmp(accept_type, "text/html")
+ && (!strcmp(avail_type, INCLUDES_MAGIC_TYPE)
+ || !strcmp(avail_type, INCLUDES_MAGIC_TYPE3)))) {
+ if (accept_r->level >= avail->level) {
+ avail->level_matched = avail->level;
+ avail->mime_stars = 3;
+ return 1;
+ }
+ }
+
+ return OK;
+}
+
+/* This code implements a piece of the tie-breaking algorithm between
+ * variants of equal quality. This piece is the treatment of variants
+ * of the same base media type, but different levels. What we want to
+ * return is the variant at the highest level that the client explicitly
+ * claimed to accept.
+ *
+ * If all the variants available are at a higher level than that, or if
+ * the client didn't say anything specific about this media type at all
+ * and these variants just got in on a wildcard, we prefer the lowest
+ * level, on grounds that that's the one that the client is least likely
+ * to choke on.
+ *
+ * (This is all motivated by treatment of levels in HTML --- we only
+ * want to give level 3 to browsers that explicitly ask for it; browsers
+ * that don't, including HTTP/0.9 browsers that only get the implicit
+ * "Accept: * / *" [space added to avoid confusing cpp --- no, that
+ * syntax doesn't really work] should get HTML2 if available).
+ *
+ * (Note that this code only comes into play when we are choosing among
+ * variants of equal quality, where the draft standard gives us a fair
+ * bit of leeway about what to do. It ain't specified by the standard;
+ * rather, it is a choice made by this server about what to do in cases
+ * where the standard does not specify a unique course of action).
+ */
+
+static int level_cmp(var_rec *var1, var_rec *var2)
+{
+ /* Levels are only comparable between matching media types */
+
+ if (var1->is_pseudo_html && !var2->is_pseudo_html) {
+ return 0;
+ }
+
+ if (!var1->is_pseudo_html && strcmp(var1->mime_type, var2->mime_type)) {
+ return 0;
+ }
+ /* The result of the above if statements is that, if we get to
+ * here, both variants have the same mime_type or both are
+ * pseudo-html.
+ */
+
+ /* Take highest level that matched, if either did match. */
+
+ if (var1->level_matched > var2->level_matched) {
+ return 1;
+ }
+ if (var1->level_matched < var2->level_matched) {
+ return -1;
+ }
+
+ /* Neither matched. Take lowest level, if there's a difference. */
+
+ if (var1->level < var2->level) {
+ return 1;
+ }
+ if (var1->level > var2->level) {
+ return -1;
+ }
+
+ /* Tied */
+
+ return 0;
+}
+
+/* Finding languages. The main entry point is set_language_quality()
+ * which is called for each variant. It sets two elements in the
+ * variant record:
+ * language_quality - the 'q' value of the 'best' matching language
+ * from Accept-Language: header (HTTP/1.1)
+ * lang_index - Non-negotiated language priority, using
+ * position of language on the Accept-Language:
+ * header, if present, else LanguagePriority
+ * directive order.
+ *
+ * When we do the variant checking for best variant, we use language
+ * quality first, and if a tie, language_index next (this only applies
+ * when _not_ using the RVSA/1.0 algorithm). If using the RVSA/1.0
+ * algorithm, lang_index is never used.
+ *
+ * set_language_quality() calls find_lang_index() and find_default_index()
+ * to set lang_index.
+ */
+
+static int find_lang_index(apr_array_header_t *accept_langs, char *lang)
+{
+ const char **alang;
+ int i;
+
+ if (!lang || !accept_langs) {
+ return -1;
+ }
+
+ alang = (const char **) accept_langs->elts;
+
+ for (i = 0; i < accept_langs->nelts; ++i) {
+ if (!strncmp(lang, *alang, strlen(*alang))) {
+ return i;
+ }
+ alang += (accept_langs->elt_size / sizeof(char*));
+ }
+
+ return -1;
+}
+
+/* set_default_lang_quality() sets the quality we apply to variants
+ * which have no language assigned to them. If none of the variants
+ * have a language, we are not negotiating on language, so all are
+ * acceptable, and we set the default q value to 1.0. However if
+ * some of the variants have languages, we set this default to 0.0001.
+ * The value of this default will be applied to all variants with
+ * no explicit language -- which will have the effect of making them
+ * acceptable, but only if no variants with an explicit language
+ * are acceptable. The default q value set here is assigned to variants
+ * with no language type in set_language_quality().
+ *
+ * Note that if using the RVSA/1.0 algorithm, we don't use this
+ * fiddle.
+ */
+
+static void set_default_lang_quality(negotiation_state *neg)
+{
+ var_rec *avail_recs = (var_rec *) neg->avail_vars->elts;
+ int j;
+
+ if (!neg->dont_fiddle_headers) {
+ for (j = 0; j < neg->avail_vars->nelts; ++j) {
+ var_rec *variant = &avail_recs[j];
+ if (variant->content_languages &&
+ variant->content_languages->nelts) {
+ neg->default_lang_quality = 0.0001f;
+ return;
+ }
+ }
+ }
+
+ neg->default_lang_quality = 1.0f;
+}
+
+/* Set the language_quality value in the variant record. Also
+ * assigns lang_index for ForceLanguagePriority.
+ *
+ * To find the language_quality value, we look for the 'q' value
+ * of the 'best' matching language on the Accept-Language
+ * header. The 'best' match is the language on Accept-Language
+ * header which matches the language of this variant either fully,
+ * or as far as the prefix marker (-). If two or more languages
+ * match, use the longest string from the Accept-Language header
+ * (see HTTP/1.1 [14.4])
+ *
+ * When a variant has multiple languages, we find the 'best'
+ * match for each variant language tag as above, then select the
+ * one with the highest q value. Because both the accept-header
+ * and variant can have multiple languages, we now have a hairy
+ * loop-within-a-loop here.
+ *
+ * If the variant has no language and we have no Accept-Language
+ * items, leave the quality at 1.0 and return.
+ *
+ * If the variant has no language, we use the default as set by
+ * set_default_lang_quality() (1.0 if we are not negotiating on
+ * language, 0.001 if we are).
+ *
+ * Following the setting of the language quality, we drop through to
+ * set the old 'lang_index'. This is set based on either the order
+ * of the languages on the Accept-Language header, or the
+ * order on the LanguagePriority directive. This is only used
+ * in the negotiation if the language qualities tie.
+ */
+
+static void set_language_quality(negotiation_state *neg, var_rec *variant)
+{
+ int forcepriority = neg->conf->forcelangpriority;
+ if (forcepriority == FLP_UNDEF) {
+ forcepriority = FLP_DEFAULT;
+ }
+
+ if (!variant->content_languages || !variant->content_languages->nelts) {
+ /* This variant has no content-language, so use the default
+ * quality factor for variants with no content-language
+ * (previously set by set_default_lang_quality()).
+ * Leave the factor alone (it remains at 1.0) when we may not fiddle
+ * with the headers.
+ */
+ if (!neg->dont_fiddle_headers) {
+ variant->lang_quality = neg->default_lang_quality;
+ }
+ if (!neg->accept_langs) {
+ return; /* no accept-language header */
+ }
+ return;
+ }
+ else {
+ /* Variant has one (or more) languages. Look for the best
+ * match. We do this by going through each language on the
+ * variant description looking for a match on the
+ * Accept-Language header. The best match is the longest
+ * matching language on the header. The final result is the
+ * best q value from all the languages on the variant
+ * description.
+ */
+
+ if (!neg->accept_langs) {
+ /* no accept-language header makes the variant indefinite */
+ variant->definite = 0;
+ }
+ else { /* There is an accept-language with 0 or more items */
+ accept_rec *accs = (accept_rec *) neg->accept_langs->elts;
+ accept_rec *best = NULL, *star = NULL;
+ accept_rec *bestthistag;
+ char *lang, *p;
+ float fiddle_q = 0.0f;
+ int any_match_on_star = 0;
+ int i, j;
+ apr_size_t alen, longest_lang_range_len;
+
+ for (j = 0; j < variant->content_languages->nelts; ++j) {
+ p = NULL;
+ bestthistag = NULL;
+ longest_lang_range_len = 0;
+ alen = 0;
+
+ /* lang is the variant's language-tag, which is the one
+ * we are allowed to use the prefix of in HTTP/1.1
+ */
+ lang = ((char **) (variant->content_languages->elts))[j];
+
+ /* now find the best (i.e. longest) matching
+ * Accept-Language header language. We put the best match
+ * for this tag in bestthistag. We cannot update the
+ * overall best (based on q value) because the best match
+ * for this tag is the longest language item on the accept
+ * header, not necessarily the highest q.
+ */
+ for (i = 0; i < neg->accept_langs->nelts; ++i) {
+ if (!strcmp(accs[i].name, "*")) {
+ if (!star) {
+ star = &accs[i];
+ }
+ continue;
+ }
+ /* Find language. We match if either the variant
+ * language tag exactly matches the language range
+ * from the accept header, or a prefix of the variant
+ * language tag up to a '-' character matches the
+ * whole of the language range in the Accept-Language
+ * header. Note that HTTP/1.x allows any number of
+ * '-' characters in a tag or range, currently only
+ * tags with zero or one '-' characters are defined
+ * for general use (see rfc1766).
+ *
+ * We only use language range in the Accept-Language
+ * header the best match for the variant language tag
+ * if it is longer than the previous best match.
+ */
+
+ alen = strlen(accs[i].name);
+
+ if ((strlen(lang) >= alen) &&
+ !strncmp(lang, accs[i].name, alen) &&
+ ((lang[alen] == 0) || (lang[alen] == '-')) ) {
+
+ if (alen > longest_lang_range_len) {
+ longest_lang_range_len = alen;
+ bestthistag = &accs[i];
+ }
+ }
+
+ if (!bestthistag && !neg->dont_fiddle_headers) {
+ /* The next bit is a fiddle. Some browsers might
+ * be configured to send more specific language
+ * ranges than desirable. For example, an
+ * Accept-Language of en-US should never match
+ * variants with languages en or en-GB. But US
+ * English speakers might pick en-US as their
+ * language choice. So this fiddle checks if the
+ * language range has a prefix, and if so, it
+ * matches variants which match that prefix with a
+ * priority of 0.001. So a request for en-US would
+ * match variants of types en and en-GB, but at
+ * much lower priority than matches of en-US
+ * directly, or of any other language listed on
+ * the Accept-Language header. Note that this
+ * fiddle does not handle multi-level prefixes.
+ */
+ if ((p = strchr(accs[i].name, '-'))) {
+ int plen = p - accs[i].name;
+
+ if (!strncmp(lang, accs[i].name, plen)) {
+ fiddle_q = 0.001f;
+ }
+ }
+ }
+ }
+ /* Finished looking at Accept-Language headers, the best
+ * (longest) match is in bestthistag, or NULL if no match
+ */
+ if (!best ||
+ (bestthistag && bestthistag->quality > best->quality)) {
+ best = bestthistag;
+ }
+
+ /* See if the tag matches on a * in the Accept-Language
+ * header. If so, record this fact for later use
+ */
+ if (!bestthistag && star) {
+ any_match_on_star = 1;
+ }
+ }
+
+ /* If one of the language tags of the variant matched on *, we
+ * need to see if its q is better than that of any non-* match
+ * on any other tag of the variant. If so the * match takes
+ * precedence and the overall match is not definite.
+ */
+ if ( any_match_on_star &&
+ ((best && star->quality > best->quality) ||
+ (!best)) ) {
+ best = star;
+ variant->definite = 0;
+ }
+
+ variant->lang_quality = best ? best->quality : fiddle_q;
+ }
+ }
+
+ /* Handle the ForceDefaultLanguage overrides, based on the best match
+ * to LanguagePriority order. The best match is the lowest index of
+ * any LanguagePriority match.
+ */
+ if (((forcepriority & FLP_PREFER)
+ && (variant->lang_index < 0))
+ || ((forcepriority & FLP_FALLBACK)
+ && !variant->lang_quality))
+ {
+ int bestidx = -1;
+ int j;
+
+ for (j = 0; j < variant->content_languages->nelts; ++j)
+ {
+ /* lang is the variant's language-tag, which is the one
+ * we are allowed to use the prefix of in HTTP/1.1
+ */
+ char *lang = ((char **) (variant->content_languages->elts))[j];
+ int idx = -1;
+
+ /* If we wish to fallback or
+ * we use our own LanguagePriority index.
+ */
+ idx = find_lang_index(neg->conf->language_priority, lang);
+ if ((idx >= 0) && ((bestidx == -1) || (idx < bestidx))) {
+ bestidx = idx;
+ }
+ }
+
+ if (bestidx >= 0) {
+ if (variant->lang_quality) {
+ if (forcepriority & FLP_PREFER) {
+ variant->lang_index = bestidx;
+ }
+ }
+ else {
+ if (forcepriority & FLP_FALLBACK) {
+ variant->lang_index = bestidx;
+ variant->lang_quality = .0001f;
+ variant->definite = 0;
+ }
+ }
+ }
+ }
+ return;
+}
+
+/* Determining the content length --- if the map didn't tell us,
+ * we have to do a stat() and remember for next time.
+ */
+
+static apr_off_t find_content_length(negotiation_state *neg, var_rec *variant)
+{
+ apr_finfo_t statb;
+
+ if (variant->bytes < 0) {
+ if ( variant->sub_req
+ && (variant->sub_req->finfo.valid & APR_FINFO_SIZE)) {
+ variant->bytes = variant->sub_req->finfo.size;
+ }
+ else {
+ char *fullname = ap_make_full_path(neg->pool, neg->dir_name,
+ variant->file_name);
+
+ if (apr_stat(&statb, fullname,
+ APR_FINFO_SIZE, neg->pool) == APR_SUCCESS) {
+ variant->bytes = statb.size;
+ }
+ }
+ }
+
+ return variant->bytes;
+}
+
+/* For a given variant, find the best matching Accept: header
+ * and assign the Accept: header's quality value to the
+ * mime_type_quality field of the variant, for later use in
+ * determining the best matching variant.
+ */
+
+static void set_accept_quality(negotiation_state *neg, var_rec *variant)
+{
+ int i;
+ accept_rec *accept_recs;
+ float q = 0.0f;
+ int q_definite = 1;
+
+ /* if no Accept: header, leave quality alone (will
+ * remain at the default value of 1)
+ *
+ * XXX: This if is currently never true because of the effect of
+ * maybe_add_default_accepts().
+ */
+ if (!neg->accepts) {
+ if (variant->mime_type && *variant->mime_type)
+ variant->definite = 0;
+ return;
+ }
+
+ accept_recs = (accept_rec *) neg->accepts->elts;
+
+ /*
+ * Go through each of the ranges on the Accept: header,
+ * looking for the 'best' match with this variant's
+ * content-type. We use the best match's quality
+ * value (from the Accept: header) for this variant's
+ * mime_type_quality field.
+ *
+ * The best match is determined like this:
+ * type/type is better than type/ * is better than * / *
+ * if match is type/type, use the level mime param if available
+ */
+ for (i = 0; i < neg->accepts->nelts; ++i) {
+
+ accept_rec *type = &accept_recs[i];
+ int prev_mime_stars;
+
+ prev_mime_stars = variant->mime_stars;
+
+ if (!mime_match(type, variant)) {
+ continue; /* didn't match the content type at all */
+ }
+ else {
+ /* did match - see if there were less or more stars than
+ * in previous match
+ */
+ if (prev_mime_stars == variant->mime_stars) {
+ continue; /* more stars => not as good a match */
+ }
+ }
+
+ /* If we are allowed to mess with the q-values
+ * and have no explicit q= parameters in the accept header,
+ * make wildcards very low, so we have a low chance
+ * of ending up with them if there's something better.
+ */
+
+ if (!neg->dont_fiddle_headers && !neg->accept_q &&
+ variant->mime_stars == 1) {
+ q = 0.01f;
+ }
+ else if (!neg->dont_fiddle_headers && !neg->accept_q &&
+ variant->mime_stars == 2) {
+ q = 0.02f;
+ }
+ else {
+ q = type->quality;
+ }
+
+ q_definite = (variant->mime_stars == 3);
+ }
+ variant->mime_type_quality = q;
+ variant->definite = variant->definite && q_definite;
+
+}
+
+/* For a given variant, find the 'q' value of the charset given
+ * on the Accept-Charset line. If no charsets are listed,
+ * assume value of '1'.
+ */
+static void set_charset_quality(negotiation_state *neg, var_rec *variant)
+{
+ int i;
+ accept_rec *accept_recs;
+ const char *charset = variant->content_charset;
+ accept_rec *star = NULL;
+
+ /* if no Accept-Charset: header, leave quality alone (will
+ * remain at the default value of 1)
+ */
+ if (!neg->accept_charsets) {
+ if (charset && *charset)
+ variant->definite = 0;
+ return;
+ }
+
+ accept_recs = (accept_rec *) neg->accept_charsets->elts;
+
+ if (charset == NULL || !*charset) {
+ /* Charset of variant not known */
+
+ /* if not a text / * type, leave quality alone */
+ if (!(!strncmp(variant->mime_type, "text/", 5)
+ || !strcmp(variant->mime_type, INCLUDES_MAGIC_TYPE)
+ || !strcmp(variant->mime_type, INCLUDES_MAGIC_TYPE3)
+ ))
+ return;
+
+ /* Don't go guessing if we are in strict header mode,
+ * e.g. when running the rvsa, as any guess won't be reflected
+ * in the variant list or content-location headers.
+ */
+ if (neg->dont_fiddle_headers)
+ return;
+
+ charset = "iso-8859-1"; /* The default charset for HTTP text types */
+ }
+
+ /*
+ * Go through each of the items on the Accept-Charset header,
+ * looking for a match with this variant's charset. If none
+ * match, charset is unacceptable, so set quality to 0.
+ */
+ for (i = 0; i < neg->accept_charsets->nelts; ++i) {
+
+ accept_rec *type = &accept_recs[i];
+
+ if (!strcmp(type->name, charset)) {
+ variant->charset_quality = type->quality;
+ return;
+ }
+ else if (strcmp(type->name, "*") == 0) {
+ star = type;
+ }
+ }
+ /* No explicit match */
+ if (star) {
+ variant->charset_quality = star->quality;
+ variant->definite = 0;
+ return;
+ }
+ /* If this variant is in charset iso-8859-1, the default is 1.0 */
+ if (strcmp(charset, "iso-8859-1") == 0) {
+ variant->charset_quality = 1.0f;
+ }
+ else {
+ variant->charset_quality = 0.0f;
+ }
+}
+
+
+/* is_identity_encoding is included for back-compat, but does anyone
+ * use 7bit, 8bin or binary in their var files??
+ */
+
+static int is_identity_encoding(const char *enc)
+{
+ return (!enc || !enc[0] || !strcmp(enc, "7bit") || !strcmp(enc, "8bit")
+ || !strcmp(enc, "binary"));
+}
+
+/*
+ * set_encoding_quality determines whether the encoding for a particular
+ * variant is acceptable for the user-agent.
+ *
+ * The rules for encoding are that if the user-agent does not supply
+ * any Accept-Encoding header, then all encodings are allowed but a
+ * variant with no encoding should be preferred.
+ * If there is an empty Accept-Encoding header, then no encodings are
+ * acceptable. If there is a non-empty Accept-Encoding header, then
+ * any of the listed encodings are acceptable, as well as no encoding
+ * unless the "identity" encoding is specifically excluded.
+ */
+static void set_encoding_quality(negotiation_state *neg, var_rec *variant)
+{
+ accept_rec *accept_recs;
+ const char *enc = variant->content_encoding;
+ accept_rec *star = NULL;
+ float value_if_not_found = 0.0f;
+ int i;
+
+ if (!neg->accept_encodings) {
+ /* We had no Accept-Encoding header, assume that all
+ * encodings are acceptable with a low quality,
+ * but we prefer no encoding if available.
+ */
+ if (!enc || is_identity_encoding(enc))
+ variant->encoding_quality = 1.0f;
+ else
+ variant->encoding_quality = 0.5f;
+
+ return;
+ }
+
+ if (!enc || is_identity_encoding(enc)) {
+ enc = "identity";
+ value_if_not_found = 0.0001f;
+ }
+
+ accept_recs = (accept_rec *) neg->accept_encodings->elts;
+
+ /* Go through each of the encodings on the Accept-Encoding: header,
+ * looking for a match with our encoding. x- prefixes are ignored.
+ */
+ if (enc[0] == 'x' && enc[1] == '-') {
+ enc += 2;
+ }
+ for (i = 0; i < neg->accept_encodings->nelts; ++i) {
+
+ char *name = accept_recs[i].name;
+
+ if (name[0] == 'x' && name[1] == '-') {
+ name += 2;
+ }
+
+ if (!strcmp(name, enc)) {
+ variant->encoding_quality = accept_recs[i].quality;
+ return;
+ }
+
+ if (strcmp(name, "*") == 0) {
+ star = &accept_recs[i];
+ }
+
+ }
+ /* No explicit match */
+ if (star) {
+ variant->encoding_quality = star->quality;
+ return;
+ }
+
+ /* Encoding not found on Accept-Encoding: header, so it is
+ * _not_ acceptable unless it is the identity (no encoding)
+ */
+ variant->encoding_quality = value_if_not_found;
+}
+
+/*************************************************************
+ * Possible results of the variant selection algorithm
+ */
+enum algorithm_results {
+ alg_choice = 1, /* choose variant */
+ alg_list /* list variants */
+};
+
+/* Below is the 'best_match' function. It returns an int, which has
+ * one of the two values alg_choice or alg_list, which give the result
+ * of the variant selection algorithm. alg_list means that no best
+ * variant was found by the algorithm, alg_choice means that a best
+ * variant was found and should be returned. The list/choice
+ * terminology comes from TCN (rfc2295), but is used in a more generic
+ * way here. The best variant is returned in *pbest. best_match has
+ * two possible algorithms for determining the best variant: the
+ * RVSA/1.0 algorithm (from RFC2296), and the standard Apache
+ * algorithm. These are split out into separate functions
+ * (is_variant_better_rvsa() and is_variant_better()). Selection of
+ * one is through the neg->use_rvsa flag.
+ *
+ * The call to best_match also creates full information, including
+ * language, charset, etc quality for _every_ variant. This is needed
+ * for generating a correct Vary header, and can be used for the
+ * Alternates header, the human-readable list responses and 406 errors.
+ */
+
+/* Firstly, the RVSA/1.0 (HTTP Remote Variant Selection Algorithm
+ * v1.0) from rfc2296. This is the algorithm that goes together with
+ * transparent content negotiation (TCN).
+ */
+static int is_variant_better_rvsa(negotiation_state *neg, var_rec *variant,
+ var_rec *best, float *p_bestq)
+{
+ float bestq = *p_bestq, q;
+
+ /* TCN does not cover negotiation on content-encoding. For now,
+ * we ignore the encoding unless it was explicitly excluded.
+ */
+ if (variant->encoding_quality == 0.0f)
+ return 0;
+
+ q = variant->mime_type_quality *
+ variant->source_quality *
+ variant->charset_quality *
+ variant->lang_quality;
+
+ /* RFC 2296 calls for the result to be rounded to 5 decimal places,
+ * but we don't do that because it serves no useful purpose other
+ * than to ensure that a remote algorithm operates on the same
+ * precision as ours. That is silly, since what we obviously want
+ * is for the algorithm to operate on the best available precision
+ * regardless of who runs it. Since the above calculation may
+ * result in significant variance at 1e-12, rounding would be bogus.
+ */
+
+#ifdef NEG_DEBUG
+ ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
+ "Variant: file=%s type=%s lang=%s sourceq=%1.3f "
+ "mimeq=%1.3f langq=%1.3f charq=%1.3f encq=%1.3f "
+ "q=%1.5f definite=%d",
+ (variant->file_name ? variant->file_name : ""),
+ (variant->mime_type ? variant->mime_type : ""),
+ (variant->content_languages
+ ? apr_array_pstrcat(neg->pool, variant->content_languages, ',')
+ : ""),
+ variant->source_quality,
+ variant->mime_type_quality,
+ variant->lang_quality,
+ variant->charset_quality,
+ variant->encoding_quality,
+ q,
+ variant->definite);
+#endif
+
+ if (q <= 0.0f) {
+ return 0;
+ }
+ if (q > bestq) {
+ *p_bestq = q;
+ return 1;
+ }
+ if (q == bestq) {
+ /* If the best variant's encoding is of lesser quality than
+ * this variant, then we prefer this variant
+ */
+ if (variant->encoding_quality > best->encoding_quality) {
+ *p_bestq = q;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/* Negotiation algorithm as used by previous versions of Apache
+ * (just about).
+ */
+
+static int is_variant_better(negotiation_state *neg, var_rec *variant,
+ var_rec *best, float *p_bestq)
+{
+ float bestq = *p_bestq, q;
+ int levcmp;
+
+ /* For non-transparent negotiation, server can choose how
+ * to handle the negotiation. We'll use the following in
+ * order: content-type, language, content-type level, charset,
+ * content encoding, content length.
+ *
+ * For each check, we have three possible outcomes:
+ * This variant is worse than current best: return 0
+ * This variant is better than the current best:
+ * assign this variant's q to *p_bestq, and return 1
+ * This variant is just as desirable as the current best:
+ * drop through to the next test.
+ *
+ * This code is written in this long-winded way to allow future
+ * customisation, either by the addition of additional
+ * checks, or to allow the order of the checks to be determined
+ * by configuration options (e.g. we might prefer to check
+ * language quality _before_ content type).
+ */
+
+ /* First though, eliminate this variant if it is not
+ * acceptable by type, charset, encoding or language.
+ */
+
+#ifdef NEG_DEBUG
+ ap_log_error(APLOG_MARK, APLOG_STARTUP, 0, NULL,
+ "Variant: file=%s type=%s lang=%s sourceq=%1.3f "
+ "mimeq=%1.3f langq=%1.3f langidx=%d charq=%1.3f encq=%1.3f ",
+ (variant->file_name ? variant->file_name : ""),
+ (variant->mime_type ? variant->mime_type : ""),
+ (variant->content_languages
+ ? apr_array_pstrcat(neg->pool, variant->content_languages, ',')
+ : ""),
+ variant->source_quality,
+ variant->mime_type_quality,
+ variant->lang_quality,
+ variant->lang_index,
+ variant->charset_quality,
+ variant->encoding_quality);
+#endif
+
+ if (variant->encoding_quality == 0.0f ||
+ variant->lang_quality == 0.0f ||
+ variant->source_quality == 0.0f ||
+ variant->charset_quality == 0.0f ||
+ variant->mime_type_quality == 0.0f) {
+ return 0; /* don't consider unacceptables */
+ }
+
+ q = variant->mime_type_quality * variant->source_quality;
+ if (q == 0.0 || q < bestq) {
+ return 0;
+ }
+ if (q > bestq || !best) {
+ *p_bestq = q;
+ return 1;
+ }
+
+ /* language */
+ if (variant->lang_quality < best->lang_quality) {
+ return 0;
+ }
+ if (variant->lang_quality > best->lang_quality) {
+ *p_bestq = q;
+ return 1;
+ }
+
+ /* if language qualities were equal, try the LanguagePriority stuff */
+ if (best->lang_index != -1 &&
+ (variant->lang_index == -1 || variant->lang_index > best->lang_index)) {
+ return 0;
+ }
+ if (variant->lang_index != -1 &&
+ (best->lang_index == -1 || variant->lang_index < best->lang_index)) {
+ *p_bestq = q;
+ return 1;
+ }
+
+ /* content-type level (sometimes used with text/html, though we
+ * support it on other types too)
+ */
+ levcmp = level_cmp(variant, best);
+ if (levcmp == -1) {
+ return 0;
+ }
+ if (levcmp == 1) {
+ *p_bestq = q;
+ return 1;
+ }
+
+ /* charset */
+ if (variant->charset_quality < best->charset_quality) {
+ return 0;
+ }
+ /* If the best variant's charset is ISO-8859-1 and this variant has
+ * the same charset quality, then we prefer this variant
+ */
+
+ if (variant->charset_quality > best->charset_quality ||
+ ((variant->content_charset != NULL &&
+ *variant->content_charset != '\0' &&
+ strcmp(variant->content_charset, "iso-8859-1") != 0) &&
+ (best->content_charset == NULL ||
+ *best->content_charset == '\0' ||
+ strcmp(best->content_charset, "iso-8859-1") == 0))) {
+ *p_bestq = q;
+ return 1;
+ }
+
+ /* Prefer the highest value for encoding_quality.
+ */
+ if (variant->encoding_quality < best->encoding_quality) {
+ return 0;
+ }
+ if (variant->encoding_quality > best->encoding_quality) {
+ *p_bestq = q;
+ return 1;
+ }
+
+ /* content length if all else equal */
+ if (find_content_length(neg, variant) >= find_content_length(neg, best)) {
+ return 0;
+ }
+
+ /* ok, to get here means every thing turned out equal, except
+ * we have a shorter content length, so use this variant
+ */
+ *p_bestq = q;
+ return 1;
+}
+
+/* figure out, whether a variant is in a specific language
+ * it returns also false, if the variant has no language.
+ */
+static int variant_has_language(var_rec *variant, const char *lang)
+{
+ int j, max;
+
+ /* fast exit */
+ if ( !lang
+ || !variant->content_languages
+ || !(max = variant->content_languages->nelts)) {
+ return 0;
+ }
+
+ for (j = 0; j < max; ++j) {
+ if (!strcmp(lang,
+ ((char **) (variant->content_languages->elts))[j])) {
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/* check for environment variables 'no-gzip' and
+ * 'gzip-only-text/html' to get a behaviour similiar
+ * to mod_deflate
+ */
+static int discard_variant_by_env(var_rec *variant, int discard)
+{
+ if ( is_identity_encoding(variant->content_encoding)
+ || !strcmp(variant->content_encoding, "identity")) {
+ return 0;
+ }
+
+ return ( (discard == DISCARD_ALL_ENCODINGS)
+ || (discard == DISCARD_ALL_BUT_HTML
+ && (!variant->mime_type
+ || strncmp(variant->mime_type, "text/html", 9))));
+}
+
+static int best_match(negotiation_state *neg, var_rec **pbest)
+{
+ int j;
+ var_rec *best;
+ float bestq = 0.0f;
+ enum algorithm_results algorithm_result;
+ int may_discard = 0;
+
+ var_rec *avail_recs = (var_rec *) neg->avail_vars->elts;
+
+ /* fetch request dependent variables
+ * prefer-language: prefer a certain language.
+ */
+ const char *preferred_language = apr_table_get(neg->r->subprocess_env,
+ "prefer-language");
+
+ /* no-gzip: do not send encoded documents */
+ if (apr_table_get(neg->r->subprocess_env, "no-gzip")) {
+ may_discard = DISCARD_ALL_ENCODINGS;
+ }
+
+ /* gzip-only-text/html: send encoded documents only
+ * if they are text/html. (no-gzip has a higher priority).
+ */
+ else {
+ const char *env_value = apr_table_get(neg->r->subprocess_env,
+ "gzip-only-text/html");
+
+ if (env_value && !strcmp(env_value, "1")) {
+ may_discard = DISCARD_ALL_BUT_HTML;
+ }
+ }
+
+ set_default_lang_quality(neg);
+
+ /*
+ * Find the 'best' variant
+ * We run the loop possibly twice: if "prefer-language"
+ * environment variable is set but we did not find an appropriate
+ * best variant. In that case forget the preferred language and
+ * negotiate over all variants.
+ */
+
+ do {
+ best = NULL;
+
+ for (j = 0; j < neg->avail_vars->nelts; ++j) {
+ var_rec *variant = &avail_recs[j];
+
+ /* if this variant is encoded somehow and there are special
+ * variables set, we do not negotiate it. see above.
+ */
+ if ( may_discard
+ && discard_variant_by_env(variant, may_discard)) {
+ continue;
+ }
+
+ /* if a language is preferred, but the current variant
+ * is not in that language, then drop it for now
+ */
+ if ( preferred_language
+ && !variant_has_language(variant, preferred_language)) {
+ continue;
+ }
+
+ /* Find all the relevant 'quality' values from the
+ * Accept... headers, and store in the variant. This also
+ * prepares for sending an Alternates header etc so we need to
+ * do it even if we do not actually plan to find a best
+ * variant.
+ */
+ set_accept_quality(neg, variant);
+ /* accept the preferred language, even when it's not listed within
+ * the Accept-Language header
+ */
+ if (preferred_language) {
+ variant->lang_quality = 1.0f;
+ variant->definite = 1;
+ }
+ else {
+ set_language_quality(neg, variant);
+ }
+ set_encoding_quality(neg, variant);
+ set_charset_quality(neg, variant);
+
+ /* Only do variant selection if we may actually choose a
+ * variant for the client
+ */
+ if (neg->may_choose) {
+
+ /* Now find out if this variant is better than the current
+ * best, either using the RVSA/1.0 algorithm, or Apache's
+ * internal server-driven algorithm. Presumably other
+ * server-driven algorithms are possible, and could be
+ * implemented here.
+ */
+
+ if (neg->use_rvsa) {
+ if (is_variant_better_rvsa(neg, variant, best, &bestq)) {
+ best = variant;
+ }
+ }
+ else {
+ if (is_variant_better(neg, variant, best, &bestq)) {
+ best = variant;
+ }
+ }
+ }
+ }
+
+ /* We now either have a best variant, or no best variant */
+
+ if (neg->use_rvsa) {
+ /* calculate result for RVSA/1.0 algorithm:
+ * only a choice response if the best variant has q>0
+ * and is definite
+ */
+ algorithm_result = (best && best->definite) && (bestq > 0) ?
+ alg_choice : alg_list;
+ }
+ else {
+ /* calculate result for Apache negotiation algorithm */
+ algorithm_result = bestq > 0 ? alg_choice : alg_list;
+ }
+
+ /* run the loop again, if the "prefer-language" got no clear result */
+ if (preferred_language && (!best || algorithm_result != alg_choice)) {
+ preferred_language = NULL;
+ continue;
+ }
+
+ break;
+ } while (1);
+
+ /* Returning a choice response with a non-neighboring variant is a
+ * protocol security error in TCN (see rfc2295). We do *not*
+ * verify here that the variant and URI are neighbors, even though
+ * we may return alg_choice. We depend on the environment (the
+ * caller) to only declare the resource transparently negotiable if
+ * all variants are neighbors.
+ */
+ *pbest = best;
+ return algorithm_result;
+}
+
+/* Sets response headers for a negotiated response.
+ * neg->is_transparent determines whether a transparently negotiated
+ * response or a plain `server driven negotiation' response is
+ * created. Applicable headers are Alternates, Vary, and TCN.
+ *
+ * The Vary header we create is sometimes longer than is required for
+ * the correct caching of negotiated results by HTTP/1.1 caches. For
+ * example if we have 3 variants x.html, x.ps.en and x.ps.nl, and if
+ * the Accept: header assigns a 0 quality to .ps, then the results of
+ * the two server-side negotiation algorithms we currently implement
+ * will never depend on Accept-Language so we could return `Vary:
+ * negotiate, accept' instead of the longer 'Vary: negotiate, accept,
+ * accept-language' which the code below will return. A routine for
+ * computing the exact minimal Vary header would be a huge pain to code
+ * and maintain though, especially because we need to take all possible
+ * twiddles in the server-side negotiation algorithms into account.
+ */
+static void set_neg_headers(request_rec *r, negotiation_state *neg,
+ int alg_result)
+{
+ apr_table_t *hdrs;
+ var_rec *avail_recs = (var_rec *) neg->avail_vars->elts;
+ const char *sample_type = NULL;
+ const char *sample_language = NULL;
+ const char *sample_encoding = NULL;
+ const char *sample_charset = NULL;
+ char *lang;
+ char *qstr;
+ apr_off_t len;
+ apr_array_header_t *arr;
+ int max_vlist_array = (neg->avail_vars->nelts * 21);
+ int first_variant = 1;
+ int vary_by_type = 0;
+ int vary_by_language = 0;
+ int vary_by_charset = 0;
+ int vary_by_encoding = 0;
+ int j;
+
+ /* In order to avoid O(n^2) memory copies in building Alternates,
+ * we preallocate a apr_table_t with the maximum substrings possible,
+ * fill it with the variant list, and then concatenate the entire array.
+ * Note that if you change the number of substrings pushed, you also
+ * need to change the calculation of max_vlist_array above.
+ */
+ if (neg->send_alternates && neg->avail_vars->nelts)
+ arr = apr_array_make(r->pool, max_vlist_array, sizeof(char *));
+ else
+ arr = NULL;
+
+ /* Put headers into err_headers_out, since send_http_header()
+ * outputs both headers_out and err_headers_out.
+ */
+ hdrs = r->err_headers_out;
+
+ for (j = 0; j < neg->avail_vars->nelts; ++j) {
+ var_rec *variant = &avail_recs[j];
+
+ if (variant->content_languages && variant->content_languages->nelts) {
+ lang = apr_array_pstrcat(r->pool, variant->content_languages, ',');
+ }
+ else {
+ lang = NULL;
+ }
+
+ /* Calculate Vary by looking for any difference between variants */
+
+ if (first_variant) {
+ sample_type = variant->mime_type;
+ sample_charset = variant->content_charset;
+ sample_language = lang;
+ sample_encoding = variant->content_encoding;
+ }
+ else {
+ if (!vary_by_type &&
+ strcmp(sample_type ? sample_type : "",
+ variant->mime_type ? variant->mime_type : "")) {
+ vary_by_type = 1;
+ }
+ if (!vary_by_charset &&
+ strcmp(sample_charset ? sample_charset : "",
+ variant->content_charset ?
+ variant->content_charset : "")) {
+ vary_by_charset = 1;
+ }
+ if (!vary_by_language &&
+ strcmp(sample_language ? sample_language : "",
+ lang ? lang : "")) {
+ vary_by_language = 1;
+ }
+ if (!vary_by_encoding &&
+ strcmp(sample_encoding ? sample_encoding : "",
+ variant->content_encoding ?
+ variant->content_encoding : "")) {
+ vary_by_encoding = 1;
+ }
+ }
+ first_variant = 0;
+
+ if (!neg->send_alternates)
+ continue;
+
+ /* Generate the string components for this Alternates entry */
+
+ *((const char **) apr_array_push(arr)) = "{\"";
+ *((const char **) apr_array_push(arr)) = ap_escape_path_segment(r->pool, variant->file_name);
+ *((const char **) apr_array_push(arr)) = "\" ";
+
+ qstr = (char *) apr_palloc(r->pool, 6);
+ apr_snprintf(qstr, 6, "%1.3f", variant->source_quality);
+
+ /* Strip trailing zeros (saves those valuable network bytes) */
+ if (qstr[4] == '0') {
+ qstr[4] = '\0';
+ if (qstr[3] == '0') {
+ qstr[3] = '\0';
+ if (qstr[2] == '0') {
+ qstr[1] = '\0';
+ }
+ }
+ }
+ *((const char **) apr_array_push(arr)) = qstr;
+
+ if (variant->mime_type && *variant->mime_type) {
+ *((const char **) apr_array_push(arr)) = " {type ";
+ *((const char **) apr_array_push(arr)) = variant->mime_type;
+ *((const char **) apr_array_push(arr)) = "}";
+ }
+ if (variant->content_charset && *variant->content_charset) {
+ *((const char **) apr_array_push(arr)) = " {charset ";
+ *((const char **) apr_array_push(arr)) = variant->content_charset;
+ *((const char **) apr_array_push(arr)) = "}";
+ }
+ if (lang) {
+ *((const char **) apr_array_push(arr)) = " {language ";
+ *((const char **) apr_array_push(arr)) = lang;
+ *((const char **) apr_array_push(arr)) = "}";
+ }
+ if (variant->content_encoding && *variant->content_encoding) {
+ /* Strictly speaking, this is non-standard, but so is TCN */
+
+ *((const char **) apr_array_push(arr)) = " {encoding ";
+ *((const char **) apr_array_push(arr)) = variant->content_encoding;
+ *((const char **) apr_array_push(arr)) = "}";
+ }
+
+ /* Note that the Alternates specification (in rfc2295) does
+ * not require that we include {length x}, so we could omit it
+ * if determining the length is too expensive. We currently
+ * always include it though.
+ *
+ * If the variant is a CGI script, find_content_length would
+ * return the length of the script, not the output it
+ * produces, so we check for the presence of a handler and if
+ * there is one we don't add a length.
+ *
+ * XXX: TODO: This check does not detect a CGI script if we
+ * get the variant from a type map. This needs to be fixed
+ * (without breaking things if the type map specifies a
+ * content-length, which currently leads to the correct result).
+ */
+ if (!(variant->sub_req && variant->sub_req->handler)
+ && (len = find_content_length(neg, variant)) >= 0) {
+
+ *((const char **) apr_array_push(arr)) = " {length ";
+ *((const char **) apr_array_push(arr)) = apr_off_t_toa(r->pool,
+ len);
+ *((const char **) apr_array_push(arr)) = "}";
+ }
+
+ *((const char **) apr_array_push(arr)) = "}";
+ *((const char **) apr_array_push(arr)) = ", "; /* trimmed below */
+ }
+
+ if (neg->send_alternates && neg->avail_vars->nelts) {
+ arr->nelts--; /* remove last comma */
+ apr_table_mergen(hdrs, "Alternates",
+ apr_array_pstrcat(r->pool, arr, '\0'));
+ }
+
+ if (neg->is_transparent || vary_by_type || vary_by_language ||
+ vary_by_language || vary_by_charset || vary_by_encoding) {
+
+ apr_table_mergen(hdrs, "Vary", 2 + apr_pstrcat(r->pool,
+ neg->is_transparent ? ", negotiate" : "",
+ vary_by_type ? ", accept" : "",
+ vary_by_language ? ", accept-language" : "",
+ vary_by_charset ? ", accept-charset" : "",
+ vary_by_encoding ? ", accept-encoding" : "", NULL));
+ }
+
+ if (neg->is_transparent) { /* Create TCN response header */
+ apr_table_setn(hdrs, "TCN",
+ alg_result == alg_list ? "list" : "choice");
+ }
+}
+
+/**********************************************************************
+ *
+ * Return an HTML list of variants. This is output as part of the
+ * choice response or 406 status body.
+ */
+
+static char *make_variant_list(request_rec *r, negotiation_state *neg)
+{
+ apr_array_header_t *arr;
+ int i;
+ int max_vlist_array = (neg->avail_vars->nelts * 15) + 2;
+
+ /* In order to avoid O(n^2) memory copies in building the list,
+ * we preallocate a apr_table_t with the maximum substrings possible,
+ * fill it with the variant list, and then concatenate the entire array.
+ */
+ arr = apr_array_make(r->pool, max_vlist_array, sizeof(char *));
+
+ *((const char **) apr_array_push(arr)) = "Available variants:\n<ul>\n";
+
+ for (i = 0; i < neg->avail_vars->nelts; ++i) {
+ var_rec *variant = &((var_rec *) neg->avail_vars->elts)[i];
+ const char *filename = variant->file_name ? variant->file_name : "";
+ apr_array_header_t *languages = variant->content_languages;
+ const char *description = variant->description
+ ? variant->description
+ : "";
+
+ /* The format isn't very neat, and it would be nice to make
+ * the tags human readable (eg replace 'language en' with 'English').
+ * Note that if you change the number of substrings pushed, you also
+ * need to change the calculation of max_vlist_array above.
+ */
+ *((const char **) apr_array_push(arr)) = "<li><a href=\"";
+ *((const char **) apr_array_push(arr)) = filename;
+ *((const char **) apr_array_push(arr)) = "\">";
+ *((const char **) apr_array_push(arr)) = filename;
+ *((const char **) apr_array_push(arr)) = "</a> ";
+ *((const char **) apr_array_push(arr)) = description;
+
+ if (variant->mime_type && *variant->mime_type) {
+ *((const char **) apr_array_push(arr)) = ", type ";
+ *((const char **) apr_array_push(arr)) = variant->mime_type;
+ }
+ if (languages && languages->nelts) {
+ *((const char **) apr_array_push(arr)) = ", language ";
+ *((const char **) apr_array_push(arr)) = apr_array_pstrcat(r->pool,
+ languages, ',');
+ }
+ if (variant->content_charset && *variant->content_charset) {
+ *((const char **) apr_array_push(arr)) = ", charset ";
+ *((const char **) apr_array_push(arr)) = variant->content_charset;
+ }
+ if (variant->content_encoding) {
+ *((const char **) apr_array_push(arr)) = ", encoding ";
+ *((const char **) apr_array_push(arr)) = variant->content_encoding;
+ }
+ *((const char **) apr_array_push(arr)) = "</li>\n";
+ }
+ *((const char **) apr_array_push(arr)) = "</ul>\n";
+
+ return apr_array_pstrcat(r->pool, arr, '\0');
+}
+
+static void store_variant_list(request_rec *r, negotiation_state *neg)
+{
+ if (r->main == NULL) {
+ apr_table_setn(r->notes, "variant-list", make_variant_list(r, neg));
+ }
+ else {
+ apr_table_setn(r->main->notes, "variant-list",
+ make_variant_list(r->main, neg));
+ }
+}
+
+/* Called if we got a "Choice" response from the variant selection algorithm.
+ * It checks the result of the chosen variant to see if it
+ * is itself negotiated (if so, return error HTTP_VARIANT_ALSO_VARIES).
+ * Otherwise, add the appropriate headers to the current response.
+ */
+
+static int setup_choice_response(request_rec *r, negotiation_state *neg,
+ var_rec *variant)
+{
+ request_rec *sub_req;
+ const char *sub_vary;
+
+ if (!variant->sub_req) {
+ int status;
+
+ sub_req = ap_sub_req_lookup_file(variant->file_name, r, r->output_filters);
+ status = sub_req->status;
+
+ if (status != HTTP_OK &&
+ !apr_table_get(sub_req->err_headers_out, "TCN")) {
+ ap_destroy_sub_req(sub_req);
+ return status;
+ }
+ variant->sub_req = sub_req;
+ }
+ else {
+ sub_req = variant->sub_req;
+ }
+
+ /* The variant selection algorithm told us to return a "Choice"
+ * response. This is the normal variant response, with
+ * some extra headers. First, ensure that the chosen
+ * variant did or will not itself engage in transparent negotiation.
+ * If not, set the appropriate headers, and fall through to
+ * the normal variant handling
+ */
+
+ /* This catches the error that a transparent type map selects a
+ * transparent multiviews resource as the best variant.
+ *
+ * XXX: We do not signal an error if a transparent type map
+ * selects a _non_transparent multiviews resource as the best
+ * variant, because we can generate a legal negotiation response
+ * in this case. In this case, the vlist_validator of the
+ * nontransparent subrequest will be lost however. This could
+ * lead to cases in which a change in the set of variants or the
+ * negotiation algorithm of the nontransparent resource is never
+ * propagated up to a HTTP/1.1 cache which interprets Vary. To be
+ * completely on the safe side we should return HTTP_VARIANT_ALSO_VARIES
+ * for this type of recursive negotiation too.
+ */
+ if (neg->is_transparent &&
+ apr_table_get(sub_req->err_headers_out, "TCN")) {
+ return HTTP_VARIANT_ALSO_VARIES;
+ }
+
+ /* This catches the error that a transparent type map recursively
+ * selects, as the best variant, another type map which itself
+ * causes transparent negotiation to be done.
+ *
+ * XXX: Actually, we catch this error by catching all cases of
+ * type map recursion. There are some borderline recursive type
+ * map arrangements which would not produce transparent
+ * negotiation protocol errors or lack of cache propagation
+ * problems, but such arrangements are very hard to detect at this
+ * point in the control flow, so we do not bother to single them
+ * out.
+ *
+ * Recursive type maps imply a recursive arrangement of negotiated
+ * resources which is visible to outside clients, and this is not
+ * supported by the transparent negotiation caching protocols, so
+ * if we are to have generic support for recursive type maps, we
+ * have to create some configuration setting which makes all type
+ * maps non-transparent when recursion is enabled. Also, if we
+ * want recursive type map support which ensures propagation of
+ * type map changes into HTTP/1.1 caches that handle Vary, we
+ * would have to extend the current mechanism for generating
+ * variant list validators.
+ */
+ if (sub_req->handler && strcmp(sub_req->handler, "type-map") == 0) {
+ return HTTP_VARIANT_ALSO_VARIES;
+ }
+
+ /* This adds an appropriate Variant-Vary header if the subrequest
+ * is a multiviews resource.
+ *
+ * XXX: TODO: Note that this does _not_ handle any Vary header
+ * returned by a CGI if sub_req is a CGI script, because we don't
+ * see that Vary header yet at this point in the control flow.
+ * This won't cause any cache consistency problems _unless_ the
+ * CGI script also returns a Cache-Control header marking the
+ * response as cachable. This needs to be fixed, also there are
+ * problems if a CGI returns an Etag header which also need to be
+ * fixed.
+ */
+ if ((sub_vary = apr_table_get(sub_req->err_headers_out, "Vary")) != NULL) {
+ apr_table_setn(r->err_headers_out, "Variant-Vary", sub_vary);
+
+ /* Move the subreq Vary header into the main request to
+ * prevent having two Vary headers in the response, which
+ * would be legal but strange.
+ */
+ apr_table_setn(r->err_headers_out, "Vary", sub_vary);
+ apr_table_unset(sub_req->err_headers_out, "Vary");
+ }
+
+ apr_table_setn(r->err_headers_out, "Content-Location",
+ ap_escape_path_segment(r->pool, variant->file_name));
+
+ set_neg_headers(r, neg, alg_choice); /* add Alternates and Vary */
+
+ /* Still to do by caller: add Expires */
+
+ return 0;
+}
+
+/****************************************************************
+ *
+ * Executive...
+ */
+
+static int do_negotiation(request_rec *r, negotiation_state *neg,
+ var_rec **bestp, int prefer_scripts)
+{
+ var_rec *avail_recs = (var_rec *) neg->avail_vars->elts;
+ int alg_result; /* result of variant selection algorithm */
+ int res;
+ int j;
+
+ /* Decide if resource is transparently negotiable */
+
+ /* GET or HEAD? (HEAD has same method number as GET) */
+ if (r->method_number == M_GET) {
+
+ /* maybe this should be configurable, see also the comment
+ * about recursive type maps in setup_choice_response()
+ */
+ neg->is_transparent = 1;
+
+ /* We can't be transparent if we are a map file in the middle
+ * of the request URI.
+ */
+ if (r->path_info && *r->path_info)
+ neg->is_transparent = 0;
+
+ for (j = 0; j < neg->avail_vars->nelts; ++j) {
+ var_rec *variant = &avail_recs[j];
+
+ /* We can't be transparent, because of internal
+ * assumptions in best_match(), if there is a
+ * non-neighboring variant. We can have a non-neighboring
+ * variant when processing a type map.
+ */
+ if (ap_strchr_c(variant->file_name, '/'))
+ neg->is_transparent = 0;
+
+ /* We can't be transparent, because of the behavior
+ * of variant typemap bodies.
+ */
+ if (variant->body) {
+ neg->is_transparent = 0;
+ }
+ }
+ }
+
+ if (neg->is_transparent) {
+ parse_negotiate_header(r, neg);
+ }
+ else { /* configure negotiation on non-transparent resource */
+ neg->may_choose = 1;
+ }
+
+ maybe_add_default_accepts(neg, prefer_scripts);
+
+ alg_result = best_match(neg, bestp);
+
+ /* alg_result is one of
+ * alg_choice: a best variant is chosen
+ * alg_list: no best variant is chosen
+ */
+
+ if (alg_result == alg_list) {
+ /* send a list response or HTTP_NOT_ACCEPTABLE error response */
+
+ neg->send_alternates = 1; /* always include Alternates header */
+ set_neg_headers(r, neg, alg_result);
+ store_variant_list(r, neg);
+
+ if (neg->is_transparent && neg->ua_supports_trans) {
+ /* XXX todo: expires? cachability? */
+
+ /* Some HTTP/1.0 clients are known to choke when they get
+ * a 300 (multiple choices) response without a Location
+ * header. However the 300 code response we are are about
+ * to generate will only reach 1.0 clients which support
+ * transparent negotiation, and they should be OK. The
+ * response should never reach older 1.0 clients, even if
+ * we have CacheNegotiatedDocs enabled, because no 1.0
+ * proxy cache (we know of) will cache and return 300
+ * responses (they certainly won't if they conform to the
+ * HTTP/1.0 specification).
+ */
+ return HTTP_MULTIPLE_CHOICES;
+ }
+
+ if (!*bestp) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
+ "no acceptable variant: %s", r->filename);
+ return HTTP_NOT_ACCEPTABLE;
+ }
+ }
+
+ /* Variant selection chose a variant */
+
+ /* XXX todo: merge the two cases in the if statement below */
+ if (neg->is_transparent) {
+
+ if ((res = setup_choice_response(r, neg, *bestp)) != 0) {
+ return res; /* return if error */
+ }
+ }
+ else {
+ set_neg_headers(r, neg, alg_result);
+ }
+
+ /* Make sure caching works - Vary should handle HTTP/1.1, but for
+ * HTTP/1.0, we can't allow caching at all.
+ */
+
+ /* XXX: Note that we only set r->no_cache to 1, which causes
+ * Expires: <now> to be added, when responding to a HTTP/1.0
+ * client. If we return the response to a 1.1 client, we do not
+ * add Expires <now>, because doing so would degrade 1.1 cache
+ * performance by preventing re-use of the response without prior
+ * revalidation. On the other hand, if the 1.1 client is a proxy
+ * which was itself contacted by a 1.0 client, or a proxy cache
+ * which can be contacted later by 1.0 clients, then we currently
+ * rely on this 1.1 proxy to add the Expires: <now> when it
+ * forwards the response.
+ *
+ * XXX: TODO: Find out if the 1.1 spec requires proxies and
+ * tunnels to add Expires: <now> when forwarding the response to
+ * 1.0 clients. I (kh) recall it is rather vague on this point.
+ * Testing actual 1.1 proxy implementations would also be nice. If
+ * Expires: <now> is not added by proxies then we need to always
+ * include Expires: <now> ourselves to ensure correct caching, but
+ * this would degrade HTTP/1.1 cache efficiency unless we also add
+ * Cache-Control: max-age=N, which we currently don't.
+ *
+ * Roy: No, we are not going to screw over HTTP future just to
+ * ensure that people who can't be bothered to upgrade their
+ * clients will always receive perfect server-side negotiation.
+ * Hell, those clients are sending bogus accept headers anyway.
+ *
+ * Manual setting of cache-control/expires always overrides this
+ * automated kluge, on purpose.
+ */
+
+ if ((!do_cache_negotiated_docs(r->server)
+ && (r->proto_num < HTTP_VERSION(1,1)))
+ && neg->count_multiviews_variants != 1) {
+ r->no_cache = 1;
+ }
+
+ return OK;
+}
+
+static int handle_map_file(request_rec *r)
+{
+ negotiation_state *neg;
+ apr_file_t *map;
+ var_rec *best;
+ int res;
+ char *udir;
+ const char *new_req;
+
+ if(strcmp(r->handler,MAP_FILE_MAGIC_TYPE) && strcmp(r->handler,"type-map"))
+ return DECLINED;
+
+ neg = parse_accept_headers(r);
+ if ((res = read_type_map(&map, neg, r))) {
+ return res;
+ }
+
+ res = do_negotiation(r, neg, &best, 0);
+ if (res != 0) return res;
+
+ if (best->body)
+ {
+ conn_rec *c = r->connection;
+ apr_bucket_brigade *bb;
+ apr_bucket *e;
+
+ ap_allow_standard_methods(r, REPLACE_ALLOW, M_GET, M_OPTIONS,
+ M_POST, -1);
+ /* XXX: ?
+ * if (r->method_number == M_OPTIONS) {
+ * return ap_send_http_options(r);
+ *}
+ */
+ if (r->method_number != M_GET && r->method_number != M_POST) {
+ return HTTP_METHOD_NOT_ALLOWED;
+ }
+
+ /* ### These may be implemented by adding some 'extra' info
+ * of the file offset onto the etag
+ * ap_update_mtime(r, r->finfo.mtime);
+ * ap_set_last_modified(r);
+ * ap_set_etag(r);
+ */
+ ap_set_accept_ranges(r);
+ ap_set_content_length(r, best->bytes);
+
+ /* set MIME type and charset as negotiated */
+ if (best->mime_type && *best->mime_type) {
+ if (best->content_charset && *best->content_charset) {
+ ap_set_content_type(r, apr_pstrcat(r->pool,
+ best->mime_type,
+ "; charset=",
+ best->content_charset,
+ NULL));
+ }
+ else {
+ ap_set_content_type(r, apr_pstrdup(r->pool, best->mime_type));
+ }
+ }
+
+ /* set Content-language(s) as negotiated */
+ if (best->content_languages && best->content_languages->nelts) {
+ r->content_languages = apr_array_copy(r->pool,
+ best->content_languages);
+ }
+
+ /* set Content-Encoding as negotiated */
+ if (best->content_encoding && *best->content_encoding) {
+ r->content_encoding = apr_pstrdup(r->pool,
+ best->content_encoding);
+ }
+
+ if ((res = ap_meets_conditions(r)) != OK) {
+ return res;
+ }
+
+ if ((res = ap_discard_request_body(r)) != OK) {
+ return res;
+ }
+ bb = apr_brigade_create(r->pool, c->bucket_alloc);
+ e = apr_bucket_file_create(map, best->body,
+ (apr_size_t)best->bytes, r->pool,
+ c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, e);
+ e = apr_bucket_eos_create(c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, e);
+
+ return ap_pass_brigade(r->output_filters, bb);
+ }
+
+ if (r->path_info && *r->path_info) {
+ /* remove any path_info from the end of the uri before trying
+ * to change the filename. r->path_info from the original
+ * request is passed along on the redirect.
+ */
+ r->uri[ap_find_path_info(r->uri, r->path_info)] = '\0';
+ }
+ udir = ap_make_dirstr_parent(r->pool, r->uri);
+ udir = ap_escape_uri(r->pool, udir);
+ if (r->args) {
+ if (r->path_info) {
+ new_req = apr_pstrcat(r->pool, udir, best->file_name,
+ r->path_info, "?", r->args, NULL);
+ }
+ else {
+ new_req = apr_pstrcat(r->pool, udir, best->file_name,
+ "?", r->args, NULL);
+ }
+ }
+ else {
+ new_req = apr_pstrcat(r->pool, udir, best->file_name,
+ r->path_info, NULL);
+ }
+ ap_internal_redirect(new_req, r);
+ return OK;
+}
+
+static int handle_multi(request_rec *r)
+{
+ negotiation_state *neg;
+ var_rec *best, *avail_recs;
+ request_rec *sub_req;
+ int res;
+ int j;
+
+ if (r->finfo.filetype != APR_NOFILE
+ || !(ap_allow_options(r) & OPT_MULTI)) {
+ return DECLINED;
+ }
+
+ neg = parse_accept_headers(r);
+
+ if ((res = read_types_multi(neg))) {
+ return_from_multi:
+ /* free all allocated memory from subrequests */
+ avail_recs = (var_rec *) neg->avail_vars->elts;
+ for (j = 0; j < neg->avail_vars->nelts; ++j) {
+ var_rec *variant = &avail_recs[j];
+ if (variant->sub_req) {
+ ap_destroy_sub_req(variant->sub_req);
+ }
+ }
+ return res;
+ }
+ if (neg->avail_vars->nelts == 0) {
+ return DECLINED;
+ }
+
+ res = do_negotiation(r, neg, &best,
+ (r->method_number != M_GET) || r->args ||
+ (r->path_info && *r->path_info));
+ if (res != 0)
+ goto return_from_multi;
+
+ if (!(sub_req = best->sub_req)) {
+ /* We got this out of a map file, so we don't actually have
+ * a sub_req structure yet. Get one now.
+ */
+
+ sub_req = ap_sub_req_lookup_file(best->file_name, r, r->output_filters);
+ if (sub_req->status != HTTP_OK) {
+ res = sub_req->status;
+ ap_destroy_sub_req(sub_req);
+ goto return_from_multi;
+ }
+ }
+ if (sub_req->args == NULL) {
+ sub_req->args = r->args;
+ }
+
+ /* now do a "fast redirect" ... promotes the sub_req into the main req */
+ ap_internal_fast_redirect(sub_req, r);
+
+ /* give no advise for time on this subrequest. Perhaps we
+ * should tally the last mtime amoung all variants, and date
+ * the most recent, but that could confuse the proxies.
+ */
+ r->mtime = 0;
+
+ /* clean up all but our favorite variant, since that sub_req
+ * is now merged into the main request!
+ */
+ avail_recs = (var_rec *) neg->avail_vars->elts;
+ for (j = 0; j < neg->avail_vars->nelts; ++j) {
+ var_rec *variant = &avail_recs[j];
+ if (variant != best && variant->sub_req) {
+ ap_destroy_sub_req(variant->sub_req);
+ }
+ }
+ return OK;
+}
+
+/**********************************************************************
+ * There is a problem with content-encoding, as some clients send and
+ * expect an x- token (e.g. x-gzip) while others expect the plain token
+ * (i.e. gzip). To try and deal with this as best as possible we do
+ * the following: if the client sent an Accept-Encoding header and it
+ * contains a plain token corresponding to the content encoding of the
+ * response, then set content encoding using the plain token. Else if
+ * the A-E header contains the x- token use the x- token in the C-E
+ * header. Else don't do anything.
+ *
+ * Note that if no A-E header was sent, or it does not contain a token
+ * compatible with the final content encoding, then the token in the
+ * C-E header will be whatever was specified in the AddEncoding
+ * directive.
+ */
+static int fix_encoding(request_rec *r)
+{
+ const char *enc = r->content_encoding;
+ char *x_enc = NULL;
+ apr_array_header_t *accept_encodings;
+ accept_rec *accept_recs;
+ int i;
+
+ if (!enc || !*enc) {
+ return DECLINED;
+ }
+
+ if (enc[0] == 'x' && enc[1] == '-') {
+ enc += 2;
+ }
+
+ if ((accept_encodings = do_header_line(r->pool,
+ apr_table_get(r->headers_in, "Accept-Encoding"))) == NULL) {
+ return DECLINED;
+ }
+
+ accept_recs = (accept_rec *) accept_encodings->elts;
+
+ for (i = 0; i < accept_encodings->nelts; ++i) {
+ char *name = accept_recs[i].name;
+
+ if (!strcmp(name, enc)) {
+ r->content_encoding = name;
+ return OK;
+ }
+
+ if (name[0] == 'x' && name[1] == '-' && !strcmp(name+2, enc)) {
+ x_enc = name;
+ }
+ }
+
+ if (x_enc) {
+ r->content_encoding = x_enc;
+ return OK;
+ }
+
+ return DECLINED;
+}
+
+static void register_hooks(apr_pool_t *p)
+{
+ ap_hook_fixups(fix_encoding,NULL,NULL,APR_HOOK_MIDDLE);
+ ap_hook_type_checker(handle_multi,NULL,NULL,APR_HOOK_FIRST);
+ ap_hook_handler(handle_map_file,NULL,NULL,APR_HOOK_MIDDLE);
+}
+
+module AP_MODULE_DECLARE_DATA negotiation_module =
+{
+ STANDARD20_MODULE_STUFF,
+ create_neg_dir_config, /* dir config creator */
+ merge_neg_dir_configs, /* dir merger --- default is to override */
+ NULL, /* server config */
+ NULL, /* merge server config */
+ negotiation_cmds, /* command apr_table_t */
+ register_hooks /* register hooks */
+};
