diff options
Diffstat (limited to 'rubbos/app/httpd-2.0.64/modules/mappers/mod_negotiation.c')
| -rw-r--r-- | rubbos/app/httpd-2.0.64/modules/mappers/mod_negotiation.c | 3096 |
1 files changed, 0 insertions, 3096 deletions
diff --git a/rubbos/app/httpd-2.0.64/modules/mappers/mod_negotiation.c b/rubbos/app/httpd-2.0.64/modules/mappers/mod_negotiation.c deleted file mode 100644 index f8214cb4..00000000 --- a/rubbos/app/httpd-2.0.64/modules/mappers/mod_negotiation.c +++ /dev/null @@ -1,3096 +0,0 @@ -/* 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 - -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. - */ - -/* - * 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 = (float)atof(cp); - } - else if (parm[0] == 'l' && !strcmp(&parm[1], "evel")) { - result->level = (float)atof(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 += strlen(tag); - /* 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); - 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)) { - mime_info.bytes = apr_atoi64((char *)body); - 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_filename_of_pathname(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) - 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; -} - -static int best_match(negotiation_state *neg, var_rec **pbest) -{ - int j; - var_rec *best; - float bestq = 0.0f; - enum algorithm_results algorithm_result; - - var_rec *avail_recs = (var_rec *) neg->avail_vars->elts; - - const char *preferred_language = apr_table_get(neg->r->subprocess_env, - "prefer-language"); - - 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 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; - char *lenstr; - 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)) = 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. 22 bytes is enough for 2^64. - * - * 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) { - - lenstr = (char *) apr_palloc(r->pool, 22); - apr_snprintf(lenstr, 22, "%" APR_OFF_T_FMT, len); - *((const char **) apr_array_push(arr)) = " {length "; - *((const char **) apr_array_push(arr)) = lenstr; - *((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, NULL); - 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", - apr_pstrdup(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; - - 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); - */ - apr_table_setn(r->headers_out, "Accept-Ranges", "bytes"); - 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); - ap_internal_redirect(apr_pstrcat(r->pool, udir, best->file_name, - r->path_info, NULL), 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, NULL); - 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 */ -}; |