| /* Copyright 2001-2004 The Apache Software Foundation |
| * |
| * Licensed 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. |
| */ |
| |
| #define CORE_PRIVATE |
| |
| #include "mod_cache.h" |
| |
| #include <ap_provider.h> |
| |
| /* -------------------------------------------------------------- */ |
| |
| /* return true if the request is conditional */ |
| CACHE_DECLARE(int) ap_cache_request_is_conditional(request_rec *r) |
| { |
| if (apr_table_get(r->headers_in, "If-Match") || |
| apr_table_get(r->headers_in, "If-None-Match") || |
| apr_table_get(r->headers_in, "If-Modified-Since") || |
| apr_table_get(r->headers_in, "If-Unmodified-Since")) { |
| return 1; |
| } |
| return 0; |
| } |
| |
| CACHE_DECLARE(cache_provider_list *)ap_cache_get_providers(request_rec *r, |
| cache_server_conf *conf, |
| const char *url) |
| { |
| cache_provider_list *providers = NULL; |
| int i; |
| |
| /* we can't cache if there's no URL */ |
| /* Is this case even possible?? */ |
| if (!url) return NULL; |
| |
| /* loop through all the cacheenable entries */ |
| for (i = 0; i < conf->cacheenable->nelts; i++) { |
| struct cache_enable *ent = |
| (struct cache_enable *)conf->cacheenable->elts; |
| if ((ent[i].url) && !strncasecmp(url, ent[i].url, ent[i].urllen)) { |
| /* Fetch from global config and add to the list. */ |
| cache_provider *provider; |
| provider = ap_lookup_provider(CACHE_PROVIDER_GROUP, ent[i].type, |
| "0"); |
| if (!provider) { |
| /* Log an error! */ |
| } |
| else { |
| cache_provider_list *newp; |
| newp = apr_pcalloc(r->pool, sizeof(cache_provider_list)); |
| newp->provider_name = ent[i].type; |
| newp->provider = provider; |
| |
| if (!providers) { |
| providers = newp; |
| } |
| else { |
| cache_provider_list *last = providers; |
| |
| while (last->next) { |
| last = last->next; |
| } |
| last->next = newp; |
| } |
| } |
| } |
| } |
| |
| /* then loop through all the cachedisable entries |
| * Looking for urls that contain the full cachedisable url and possibly |
| * more. |
| * This means we are disabling cachedisable url and below... |
| */ |
| for (i = 0; i < conf->cachedisable->nelts; i++) { |
| struct cache_disable *ent = |
| (struct cache_disable *)conf->cachedisable->elts; |
| if ((ent[i].url) && !strncasecmp(url, ent[i].url, ent[i].urllen)) { |
| /* Stop searching now. */ |
| return NULL; |
| } |
| } |
| |
| return providers; |
| } |
| |
| |
| /* do a HTTP/1.1 age calculation */ |
| CACHE_DECLARE(apr_int64_t) ap_cache_current_age(cache_info *info, |
| const apr_time_t age_value, |
| apr_time_t now) |
| { |
| apr_time_t apparent_age, corrected_received_age, response_delay, |
| corrected_initial_age, resident_time, current_age, |
| age_value_usec; |
| |
| age_value_usec = apr_time_from_sec(age_value); |
| |
| /* Perform an HTTP/1.1 age calculation. (RFC2616 13.2.3) */ |
| |
| apparent_age = MAX(0, info->response_time - info->date); |
| corrected_received_age = MAX(apparent_age, age_value_usec); |
| response_delay = info->response_time - info->request_time; |
| corrected_initial_age = corrected_received_age + response_delay; |
| resident_time = now - info->response_time; |
| current_age = corrected_initial_age + resident_time; |
| |
| return apr_time_sec(current_age); |
| } |
| |
| CACHE_DECLARE(int) ap_cache_check_freshness(cache_request_rec *cache, |
| request_rec *r) |
| { |
| apr_int64_t age, maxage_req, maxage_cresp, maxage, smaxage, maxstale; |
| apr_int64_t minfresh; |
| int age_in_errhdr = 0; |
| const char *cc_cresp, *cc_ceresp, *cc_req; |
| const char *agestr = NULL; |
| const char *expstr = NULL; |
| char *val; |
| apr_time_t age_c = 0; |
| cache_info *info = &(cache->handle->cache_obj->info); |
| |
| /* |
| * We now want to check if our cached data is still fresh. This depends |
| * on a few things, in this order: |
| * |
| * - RFC2616 14.9.4 End to end reload, Cache-Control: no-cache. no-cache in |
| * either the request or the cached response means that we must |
| * revalidate the request unconditionally, overriding any expiration |
| * mechanism. It's equivalent to max-age=0,must-revalidate. |
| * |
| * - RFC2616 14.32 Pragma: no-cache This is treated the same as |
| * Cache-Control: no-cache. |
| * |
| * - RFC2616 14.9.3 Cache-Control: max-stale, must-revalidate, |
| * proxy-revalidate if the max-stale request header exists, modify the |
| * stale calculations below so that an object can be at most <max-stale> |
| * seconds stale before we request a revalidation, _UNLESS_ a |
| * must-revalidate or proxy-revalidate cached response header exists to |
| * stop us doing this. |
| * |
| * - RFC2616 14.9.3 Cache-Control: s-maxage the origin server specifies the |
| * maximum age an object can be before it is considered stale. This |
| * directive has the effect of proxy|must revalidate, which in turn means |
| * simple ignore any max-stale setting. |
| * |
| * - RFC2616 14.9.4 Cache-Control: max-age this header can appear in both |
| * requests and responses. If both are specified, the smaller of the two |
| * takes priority. |
| * |
| * - RFC2616 14.21 Expires: if this request header exists in the cached |
| * entity, and it's value is in the past, it has expired. |
| * |
| */ |
| cc_cresp = apr_table_get(r->headers_out, "Cache-Control"); |
| cc_ceresp = apr_table_get(r->err_headers_out, "Cache-Control"); |
| cc_req = apr_table_get(r->headers_in, "Cache-Control"); |
| |
| if ((agestr = apr_table_get(r->headers_out, "Age"))) { |
| age_c = apr_atoi64(agestr); |
| } |
| else if ((agestr = apr_table_get(r->err_headers_out, "Age"))) { |
| age_c = apr_atoi64(agestr); |
| age_in_errhdr = 1; |
| } |
| |
| if (!(expstr = apr_table_get(r->err_headers_out, "Expires"))) { |
| expstr = apr_table_get(r->headers_out, "Expires"); |
| } |
| |
| /* calculate age of object */ |
| age = ap_cache_current_age(info, age_c, r->request_time); |
| |
| /* extract s-maxage */ |
| if (cc_cresp && ap_cache_liststr(r->pool, cc_cresp, "s-maxage", &val)) { |
| smaxage = apr_atoi64(val); |
| } |
| else if (cc_ceresp && ap_cache_liststr(r->pool, cc_ceresp, "s-maxage", &val)) { |
| smaxage = apr_atoi64(val); |
| } |
| else { |
| smaxage = -1; |
| } |
| |
| /* extract max-age from request */ |
| if (cc_req && ap_cache_liststr(r->pool, cc_req, "max-age", &val)) { |
| maxage_req = apr_atoi64(val); |
| } |
| else { |
| maxage_req = -1; |
| } |
| |
| /* extract max-age from response */ |
| if (cc_cresp && ap_cache_liststr(r->pool, cc_cresp, "max-age", &val)) { |
| maxage_cresp = apr_atoi64(val); |
| } |
| else if (cc_ceresp && ap_cache_liststr(r->pool, cc_ceresp, "max-age", &val)) { |
| maxage_cresp = apr_atoi64(val); |
| } |
| else |
| { |
| maxage_cresp = -1; |
| } |
| |
| /* |
| * if both maxage request and response, the smaller one takes priority |
| */ |
| if (-1 == maxage_req) { |
| maxage = maxage_cresp; |
| } |
| else if (-1 == maxage_cresp) { |
| maxage = maxage_req; |
| } |
| else { |
| maxage = MIN(maxage_req, maxage_cresp); |
| } |
| |
| /* extract max-stale */ |
| if (cc_req && ap_cache_liststr(r->pool, cc_req, "max-stale", &val)) { |
| maxstale = apr_atoi64(val); |
| } |
| else { |
| maxstale = 0; |
| } |
| |
| /* extract min-fresh */ |
| if (cc_req && ap_cache_liststr(r->pool, cc_req, "min-fresh", &val)) { |
| minfresh = apr_atoi64(val); |
| } |
| else { |
| minfresh = 0; |
| } |
| |
| /* override maxstale if must-revalidate or proxy-revalidate */ |
| if (maxstale && ((cc_cresp && |
| ap_cache_liststr(NULL, cc_cresp, |
| "must-revalidate", NULL)) || |
| (cc_cresp && |
| ap_cache_liststr(NULL, cc_cresp, |
| "proxy-revalidate", NULL)) || |
| (cc_ceresp && |
| ap_cache_liststr(NULL, cc_ceresp, |
| "must-revalidate", NULL)) || |
| (cc_ceresp && |
| ap_cache_liststr(NULL, cc_ceresp, |
| "proxy-revalidate", NULL)))) { |
| maxstale = 0; |
| } |
| |
| /* handle expiration */ |
| if (((smaxage != -1) && (age < (smaxage - minfresh))) || |
| ((maxage != -1) && (age < (maxage + maxstale - minfresh))) || |
| ((smaxage == -1) && (maxage == -1) && |
| (info->expire != APR_DATE_BAD) && |
| (age < (apr_time_sec(info->expire - info->date) + maxstale - minfresh)))) { |
| const char *warn_head; |
| apr_table_t *head_ptr; |
| |
| warn_head = apr_table_get(r->headers_out, "Warning"); |
| if (warn_head != NULL) { |
| head_ptr = r->headers_out; |
| } |
| else { |
| warn_head = apr_table_get(r->err_headers_out, "Warning"); |
| head_ptr = r->err_headers_out; |
| } |
| |
| /* it's fresh darlings... */ |
| /* set age header on response */ |
| if (age_in_errhdr) { |
| apr_table_set(r->err_headers_out, "Age", |
| apr_psprintf(r->pool, "%lu", (unsigned long)age)); |
| } |
| else { |
| apr_table_set(r->headers_out, "Age", |
| apr_psprintf(r->pool, "%lu", (unsigned long)age)); |
| } |
| |
| /* add warning if maxstale overrode freshness calculation */ |
| if (!(((smaxage != -1) && age < smaxage) || |
| ((maxage != -1) && age < maxage) || |
| (info->expire != APR_DATE_BAD && |
| (info->expire - info->date) > age))) { |
| /* make sure we don't stomp on a previous warning */ |
| if ((warn_head == NULL) || |
| ((warn_head != NULL) && (ap_strstr_c(warn_head, "110") == NULL))) { |
| apr_table_merge(head_ptr, "Warning", "110 Response is stale"); |
| } |
| } |
| /* |
| * If none of Expires, Cache-Control: max-age, or Cache-Control: |
| * s-maxage appears in the response, and the respose header age |
| * calculated is more than 24 hours add the warning 113 |
| */ |
| if ((maxage_cresp == -1) && (smaxage == -1) && |
| (expstr == NULL) && (age > 86400)) { |
| |
| /* Make sure we don't stomp on a previous warning, and don't dup |
| * a 113 marning that is already present. Also, make sure to add |
| * the new warning to the correct *headers_out location. |
| */ |
| if ((warn_head == NULL) || |
| ((warn_head != NULL) && (ap_strstr_c(warn_head, "113") == NULL))) { |
| apr_table_merge(head_ptr, "Warning", "113 Heuristic expiration"); |
| } |
| } |
| return 1; /* Cache object is fresh (enough) */ |
| } |
| return 0; /* Cache object is stale */ |
| } |
| |
| /* |
| * list is a comma-separated list of case-insensitive tokens, with |
| * optional whitespace around the tokens. |
| * The return returns 1 if the token val is found in the list, or 0 |
| * otherwise. |
| */ |
| CACHE_DECLARE(int) ap_cache_liststr(apr_pool_t *p, const char *list, |
| const char *key, char **val) |
| { |
| apr_size_t key_len; |
| const char *next; |
| |
| if (!list) { |
| return 0; |
| } |
| |
| key_len = strlen(key); |
| next = list; |
| |
| for (;;) { |
| |
| /* skip whitespace and commas to find the start of the next key */ |
| while (*next && (apr_isspace(*next) || (*next == ','))) { |
| next++; |
| } |
| |
| if (!*next) { |
| return 0; |
| } |
| |
| if (!strncasecmp(next, key, key_len)) { |
| /* this field matches the key (though it might just be |
| * a prefix match, so make sure the match is followed |
| * by either a space or an equals sign) |
| */ |
| next += key_len; |
| if (!*next || (*next == '=') || apr_isspace(*next) || |
| (*next == ',')) { |
| /* valid match */ |
| if (val) { |
| while (*next && (*next != '=') && (*next != ',')) { |
| next++; |
| } |
| if (*next == '=') { |
| next++; |
| while (*next && apr_isspace(*next )) { |
| next++; |
| } |
| if (!*next) { |
| *val = NULL; |
| } |
| else { |
| const char *val_start = next; |
| while (*next && !apr_isspace(*next) && |
| (*next != ',')) { |
| next++; |
| } |
| *val = apr_pstrmemdup(p, val_start, |
| next - val_start); |
| } |
| } |
| } |
| return 1; |
| } |
| } |
| |
| /* skip to the next field */ |
| do { |
| next++; |
| if (!*next) { |
| return 0; |
| } |
| } while (*next != ','); |
| } |
| } |
| |
| /* return each comma separated token, one at a time */ |
| CACHE_DECLARE(const char *)ap_cache_tokstr(apr_pool_t *p, const char *list, |
| const char **str) |
| { |
| apr_size_t i; |
| const char *s; |
| |
| s = ap_strchr_c(list, ','); |
| if (s != NULL) { |
| i = s - list; |
| do |
| s++; |
| while (apr_isspace(*s)) |
| ; /* noop */ |
| } |
| else |
| i = strlen(list); |
| |
| while (i > 0 && apr_isspace(list[i - 1])) |
| i--; |
| |
| *str = s; |
| if (i) |
| return apr_pstrndup(p, list, i); |
| else |
| return NULL; |
| } |
| |
| /* |
| * Converts apr_time_t expressed as hex digits to |
| * a true apr_time_t. |
| */ |
| CACHE_DECLARE(apr_time_t) ap_cache_hex2usec(const char *x) |
| { |
| int i, ch; |
| apr_time_t j; |
| for (i = 0, j = 0; i < sizeof(j) * 2; i++) { |
| ch = x[i]; |
| j <<= 4; |
| if (apr_isdigit(ch)) |
| j |= ch - '0'; |
| else if (apr_isupper(ch)) |
| j |= ch - ('A' - 10); |
| else |
| j |= ch - ('a' - 10); |
| } |
| return j; |
| } |
| |
| /* |
| * Converts apr_time_t to apr_time_t expressed as hex digits. |
| */ |
| CACHE_DECLARE(void) ap_cache_usec2hex(apr_time_t j, char *y) |
| { |
| int i, ch; |
| |
| for (i = (sizeof(j) * 2)-1; i >= 0; i--) { |
| ch = (int)(j & 0xF); |
| j >>= 4; |
| if (ch >= 10) |
| y[i] = ch + ('A' - 10); |
| else |
| y[i] = ch + '0'; |
| } |
| y[sizeof(j) * 2] = '\0'; |
| } |
| |
| static void cache_hash(const char *it, char *val, int ndepth, int nlength) |
| { |
| apr_md5_ctx_t context; |
| unsigned char digest[16]; |
| char tmp[22]; |
| int i, k, d; |
| unsigned int x; |
| static const char enc_table[64] = |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_@"; |
| |
| apr_md5_init(&context); |
| apr_md5_update(&context, (const unsigned char *) it, strlen(it)); |
| apr_md5_final(digest, &context); |
| |
| /* encode 128 bits as 22 characters, using a modified uuencoding |
| * the encoding is 3 bytes -> 4 characters* i.e. 128 bits is |
| * 5 x 3 bytes + 1 byte -> 5 * 4 characters + 2 characters |
| */ |
| for (i = 0, k = 0; i < 15; i += 3) { |
| x = (digest[i] << 16) | (digest[i + 1] << 8) | digest[i + 2]; |
| tmp[k++] = enc_table[x >> 18]; |
| tmp[k++] = enc_table[(x >> 12) & 0x3f]; |
| tmp[k++] = enc_table[(x >> 6) & 0x3f]; |
| tmp[k++] = enc_table[x & 0x3f]; |
| } |
| |
| /* one byte left */ |
| x = digest[15]; |
| tmp[k++] = enc_table[x >> 2]; /* use up 6 bits */ |
| tmp[k++] = enc_table[(x << 4) & 0x3f]; |
| |
| /* now split into directory levels */ |
| for (i = k = d = 0; d < ndepth; ++d) { |
| memcpy(&val[i], &tmp[k], nlength); |
| k += nlength; |
| val[i + nlength] = '/'; |
| i += nlength + 1; |
| } |
| memcpy(&val[i], &tmp[k], 22 - k); |
| val[i + 22 - k] = '\0'; |
| } |
| |
| CACHE_DECLARE(char *)generate_name(apr_pool_t *p, int dirlevels, |
| int dirlength, const char *name) |
| { |
| char hashfile[66]; |
| cache_hash(name, hashfile, dirlevels, dirlength); |
| return apr_pstrdup(p, hashfile); |
| } |
| |
| /* Create a new table consisting of those elements from an input |
| * headers table that are allowed to be stored in a cache. |
| */ |
| CACHE_DECLARE(apr_table_t *)ap_cache_cacheable_hdrs_out(apr_pool_t *pool, |
| apr_table_t *t) |
| { |
| /* Make a copy of the headers, and remove from |
| * the copy any hop-by-hop headers, as defined in Section |
| * 13.5.1 of RFC 2616 |
| */ |
| apr_table_t *headers_out; |
| headers_out = apr_table_copy(pool, t); |
| apr_table_unset(headers_out, "Connection"); |
| apr_table_unset(headers_out, "Keep-Alive"); |
| apr_table_unset(headers_out, "Proxy-Authenticate"); |
| apr_table_unset(headers_out, "Proxy-Authorization"); |
| apr_table_unset(headers_out, "TE"); |
| apr_table_unset(headers_out, "Trailers"); |
| apr_table_unset(headers_out, "Transfer-Encoding"); |
| apr_table_unset(headers_out, "Upgrade"); |
| return headers_out; |
| } |
