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e4e6a8db | 1 | /* |
4ac4a490 | 2 | * Copyright (C) 1996-2017 The Squid Software Foundation and contributors |
e25c139f | 3 | * |
bbc27441 AJ |
4 | * Squid software is distributed under GPLv2+ license and includes |
5 | * contributions from numerous individuals and organizations. | |
6 | * Please see the COPYING and CONTRIBUTORS files for details. | |
e4e6a8db | 7 | */ |
8 | ||
bbc27441 AJ |
9 | /* DEBUG: section 22 Refresh Calculation */ |
10 | ||
c2afddd8 AJ |
11 | #ifndef USE_POSIX_REGEX |
12 | #define USE_POSIX_REGEX /* put before includes; always use POSIX */ | |
13 | #endif | |
14 | ||
582c2af2 | 15 | #include "squid.h" |
582c2af2 | 16 | #include "HttpHdrCc.h" |
924f73bc | 17 | #include "HttpReply.h" |
602d9612 | 18 | #include "HttpRequest.h" |
582c2af2 | 19 | #include "MemObject.h" |
602d9612 | 20 | #include "mgr/Registration.h" |
8d9a8184 | 21 | #include "RefreshPattern.h" |
4d5904f7 | 22 | #include "SquidConfig.h" |
602d9612 | 23 | #include "SquidTime.h" |
582c2af2 | 24 | #include "Store.h" |
b1bd952a | 25 | #include "URL.h" |
ed6e9fb9 | 26 | #include "util.h" |
e4e6a8db | 27 | |
7d47d8e6 | 28 | typedef enum { |
65fa5c61 | 29 | rcHTTP, |
30 | rcICP, | |
31 | #if USE_HTCP | |
32 | rcHTCP, | |
33 | #endif | |
34 | #if USE_CACHE_DIGESTS | |
35 | rcCDigest, | |
36 | #endif | |
37 | rcStore, | |
38 | rcCount | |
7d47d8e6 | 39 | } refreshCountsEnum; |
829a9357 | 40 | |
96151fc9 DD |
41 | /** |
42 | * Flags indicating which staleness algorithm has been applied. | |
43 | */ | |
26ac0430 | 44 | typedef struct { |
96151fc9 DD |
45 | bool expires; ///< Expires: header absolute timestamp limit |
46 | bool min; ///< Heuristic minimum age limited | |
47 | bool lmfactor; ///< Last-Modified with heuristic determines limit | |
48 | bool max; ///< Configured maximum age limit | |
2fadd50d | 49 | } stale_flags; |
65fa5c61 | 50 | |
51 | /* | |
52 | * This enumerated list assigns specific values, ala HTTP/FTP status | |
53 | * codes. All Fresh codes are in the range 100-199 and all stale | |
54 | * codes are 200-299. We might want to use these codes in logging, | |
55 | * so best to keep them consistent over time. | |
56 | */ | |
57 | enum { | |
58 | FRESH_REQUEST_MAX_STALE_ALL = 100, | |
59 | FRESH_REQUEST_MAX_STALE_VALUE, | |
60 | FRESH_EXPIRES, | |
61 | FRESH_LMFACTOR_RULE, | |
62 | FRESH_MIN_RULE, | |
63 | FRESH_OVERRIDE_EXPIRES, | |
64 | FRESH_OVERRIDE_LASTMOD, | |
65 | STALE_MUST_REVALIDATE = 200, | |
66 | STALE_RELOAD_INTO_IMS, | |
67 | STALE_FORCED_RELOAD, | |
68 | STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE, | |
69 | STALE_EXPIRES, | |
70 | STALE_MAX_RULE, | |
71 | STALE_LMFACTOR_RULE, | |
570d3f75 | 72 | STALE_MAX_STALE, |
65fa5c61 | 73 | STALE_DEFAULT = 299 |
74 | }; | |
75 | ||
26ac0430 | 76 | static struct RefreshCounts { |
829a9357 | 77 | const char *proto; |
1c3e77cd | 78 | int total; |
65fa5c61 | 79 | int status[STALE_DEFAULT + 1]; |
96151fc9 | 80 | } refreshCounts[rcCount]; |
1c3e77cd | 81 | |
8d9a8184 | 82 | static const RefreshPattern *refreshUncompiledPattern(const char *); |
1c3e77cd | 83 | static OBJH refreshStats; |
8d9a8184 | 84 | static int refreshStaleness(const StoreEntry * entry, time_t check_time, const time_t age, const RefreshPattern * R, stale_flags * sf); |
65fa5c61 | 85 | |
c2afddd8 | 86 | static RefreshPattern DefaultRefresh("<none>", 0); |
2b5133db | 87 | |
82b2cc12 AJ |
88 | /** Locate the first refresh_pattern rule that matches the given URL by regex. |
89 | * | |
95b8eae2 | 90 | * \return A pointer to the refresh_pattern parameters to use, or nullptr if there is no match. |
82b2cc12 | 91 | */ |
8d9a8184 | 92 | const RefreshPattern * |
6018f0de | 93 | refreshLimits(const char *url) |
94 | { | |
95b8eae2 | 95 | for (auto R = Config.Refresh; R; R = R->next) { |
a5ea7751 | 96 | ++(R->stats.matchTests); |
95b8eae2 | 97 | if (R->pattern.match(url)) { |
a5ea7751 | 98 | ++(R->stats.matchCount); |
62e76326 | 99 | return R; |
a5ea7751 | 100 | } |
6018f0de | 101 | } |
62e76326 | 102 | |
95b8eae2 | 103 | return nullptr; |
6018f0de | 104 | } |
105 | ||
82b2cc12 AJ |
106 | /** Locate the first refresh_pattern rule that has the given uncompiled regex. |
107 | * | |
108 | * \note There is only one reference to this function, below. It always passes "." as the pattern. | |
109 | * This function is only ever called if there is no URI. Because a regex match is impossible, Squid | |
110 | * forces the "." rule to apply (if it exists) | |
111 | * | |
95b8eae2 | 112 | * \return A pointer to the refresh_pattern parameters to use, or nullptr if there is no match. |
82b2cc12 | 113 | */ |
8d9a8184 | 114 | static const RefreshPattern * |
2b5133db | 115 | refreshUncompiledPattern(const char *pat) |
116 | { | |
95b8eae2 AJ |
117 | for (auto R = Config.Refresh; R; R = R->next) { |
118 | if (0 == strcmp(R->pattern.c_str(), pat)) | |
62e76326 | 119 | return R; |
2b5133db | 120 | } |
62e76326 | 121 | |
95b8eae2 | 122 | return nullptr; |
2b5133db | 123 | } |
124 | ||
b2f01ec3 | 125 | /** |
65fa5c61 | 126 | * Calculate how stale the response is (or will be at the check_time). |
96151fc9 DD |
127 | * |
128 | * We try the following ways until one gives a result: | |
129 | * | |
130 | * 1. response expiration time, if one was set | |
131 | * 2. age greater than configured maximum | |
132 | * 3. last-modified factor algorithm | |
133 | * 4. age less than configured minimum | |
134 | * 5. default (stale) | |
135 | * | |
136 | * \param entry the StoreEntry being examined | |
137 | * \param check_time the time (maybe future) at which we want to know whether $ | |
138 | * \param age the age of the entry at check_time | |
139 | * \param R the refresh_pattern rule that matched this entry | |
140 | * \param sf small struct to indicate reason for stale/fresh decision | |
65fa5c61 | 141 | * |
b2f01ec3 | 142 | * \retval -1 If the response is fresh. |
96151fc9 | 143 | * \retval >0 The amount of staleness. |
b2f01ec3 | 144 | * \retval 0 NOTE return value of 0 means the response is stale. |
65fa5c61 | 145 | */ |
146 | static int | |
8d9a8184 | 147 | refreshStaleness(const StoreEntry * entry, time_t check_time, const time_t age, const RefreshPattern * R, stale_flags * sf) |
65fa5c61 | 148 | { |
96151fc9 DD |
149 | // 1. If the cached object has an explicit expiration time, then we rely on this and |
150 | // completely ignore the Min, Percent and Max values in the refresh_pattern. | |
65fa5c61 | 151 | if (entry->expires > -1) { |
1f848b2c | 152 | sf->expires = true; |
62e76326 | 153 | |
154 | if (entry->expires > check_time) { | |
4a7a3d56 | 155 | debugs(22, 3, "FRESH: expires " << entry->expires << |
156 | " >= check_time " << check_time << " "); | |
bf8fe701 | 157 | |
62e76326 | 158 | return -1; |
159 | } else { | |
4a7a3d56 | 160 | debugs(22, 3, "STALE: expires " << entry->expires << |
161 | " < check_time " << check_time << " "); | |
bf8fe701 | 162 | |
62e76326 | 163 | return (check_time - entry->expires); |
164 | } | |
65fa5c61 | 165 | } |
62e76326 | 166 | |
96151fc9 DD |
167 | debugs(22, 3, "No explicit expiry given, using heuristics to determine freshness"); |
168 | ||
169 | // 2. If the entry is older than the maximum age in the refresh_pattern, it is STALE. | |
65fa5c61 | 170 | if (age > R->max) { |
4a7a3d56 | 171 | debugs(22, 3, "STALE: age " << age << " > max " << R->max << " "); |
1f848b2c | 172 | sf->max = true; |
62e76326 | 173 | return (age - R->max); |
65fa5c61 | 174 | } |
62e76326 | 175 | |
96151fc9 | 176 | // 3. If there is a Last-Modified header, try the last-modified factor algorithm. |
438b41ba EB |
177 | const time_t lastmod_delta = entry->timestamp - entry->lastModified(); |
178 | if (lastmod_delta > 0) { | |
96151fc9 DD |
179 | /* stale_age is the age of the response when it became/becomes stale according to |
180 | * the last-modified factor algorithm. It's how long we can consider the response | |
181 | * fresh from the time we cached it. | |
62e76326 | 182 | */ |
96151fc9 DD |
183 | time_t stale_age = static_cast<time_t>(lastmod_delta * R->pct); |
184 | ||
185 | debugs(22,3, "Last modified " << lastmod_delta << " sec before we cached it, L-M factor " << | |
86c63190 | 186 | (100.0 * R->pct) << "% = " << stale_age << " sec freshness lifetime"); |
1f848b2c | 187 | sf->lmfactor = true; |
62e76326 | 188 | |
189 | if (age >= stale_age) { | |
4a7a3d56 | 190 | debugs(22, 3, "STALE: age " << age << " > stale_age " << stale_age); |
62e76326 | 191 | return (age - stale_age); |
192 | } else { | |
4a7a3d56 | 193 | debugs(22, 3, "FRESH: age " << age << " <= stale_age " << stale_age); |
62e76326 | 194 | return -1; |
195 | } | |
65fa5c61 | 196 | } |
62e76326 | 197 | |
96151fc9 | 198 | // 4. If the entry is not as old as the minimum age in the refresh_pattern, it is FRESH. |
9e4b5932 | 199 | if (age < R->min) { |
96151fc9 | 200 | debugs(22, 3, "FRESH: age (" << age << " sec) is less than configured minimum (" << R->min << " sec)"); |
1f848b2c | 201 | sf->min = true; |
62e76326 | 202 | return -1; |
65fa5c61 | 203 | } |
62e76326 | 204 | |
96151fc9 DD |
205 | // 5. default is stale, by the amount we missed the minimum by |
206 | debugs(22, 3, "STALE: No explicit expiry, no last modified, and older than configured minimum."); | |
65fa5c61 | 207 | return (age - R->min); |
208 | } | |
209 | ||
96151fc9 DD |
210 | /** Checks whether a store entry is fresh or stale, and why. |
211 | * | |
212 | * This is where all aspects of request, response and squid configuration | |
213 | * meet to decide whether a response is cacheable or not: | |
214 | * | |
215 | * 1. Client request headers that affect cacheability, e.g. | |
216 | * - Cache-Control: no-cache | |
217 | * - Cache-Control: max-age=N | |
218 | * - Cache-Control: max-stale[=N] | |
219 | * - Pragma: no-cache | |
220 | * | |
221 | * 2. Server response headers that affect cacheability, e.g. | |
222 | * - Age: | |
223 | * - Cache-Control: proxy-revalidate | |
224 | * - Cache-Control: must-revalidate | |
225 | * - Cache-Control: no-cache | |
226 | * - Cache-Control: max-age=N | |
227 | * - Cache-Control: s-maxage=N | |
228 | * - Date: | |
229 | * - Expires: | |
230 | * - Last-Modified: | |
231 | * | |
232 | * 3. Configuration options, e.g. | |
233 | * - reload-into-ims (refresh_pattern) | |
234 | * - ignore-reload (refresh_pattern) | |
235 | * - refresh-ims (refresh_pattern) | |
236 | * - override-lastmod (refresh_pattern) | |
237 | * - override-expire (refresh_pattern) | |
238 | * - reload_into_ims (global option) | |
239 | * - refresh_all_ims (global option) | |
240 | * | |
241 | * \returns a status code (from enum above): | |
242 | * - FRESH_REQUEST_MAX_STALE_ALL | |
243 | * - FRESH_REQUEST_MAX_STALE_VALUE | |
244 | * - FRESH_EXPIRES | |
245 | * - FRESH_LMFACTOR_RULE | |
246 | * - FRESH_MIN_RULE | |
247 | * - FRESH_OVERRIDE_EXPIRES | |
248 | * - FRESH_OVERRIDE_LASTMOD | |
249 | * - STALE_MUST_REVALIDATE | |
250 | * - STALE_RELOAD_INTO_IMS | |
251 | * - STALE_FORCED_RELOAD | |
252 | * - STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE | |
253 | * - STALE_EXPIRES | |
254 | * - STALE_MAX_RULE | |
255 | * - STALE_LMFACTOR_RULE | |
256 | * - STALE_MAX_STALE | |
257 | * - STALE_DEFAULT | |
258 | * | |
259 | * \note request may be NULL (e.g. for cache digests build) | |
829a9357 | 260 | * |
96151fc9 DD |
261 | * \note the store entry being examined is not necessarily cached (e.g. if |
262 | * this response is being evaluated for the first time) | |
e4e6a8db | 263 | */ |
829a9357 | 264 | static int |
190154cf | 265 | refreshCheck(const StoreEntry * entry, HttpRequest * request, time_t delta) |
e4e6a8db | 266 | { |
65fa5c61 | 267 | time_t age = 0; |
a207429f | 268 | time_t check_time = squid_curtime + delta; |
65fa5c61 | 269 | int staleness; |
270 | stale_flags sf; | |
62e76326 | 271 | |
96151fc9 | 272 | // get the URL of this entry, if there is one |
851feda6 AJ |
273 | static const SBuf nilUri("<none>"); |
274 | SBuf uri = nilUri; | |
9b5d1d21 | 275 | if (entry->mem_obj) |
c877c0bc | 276 | uri = entry->mem_obj->storeId(); |
7d47d8e6 | 277 | else if (request) |
851feda6 | 278 | uri = request->effectiveRequestUri(); |
7d47d8e6 | 279 | |
851feda6 | 280 | debugs(22, 3, "checking freshness of URI: " << uri); |
65fa5c61 | 281 | |
96151fc9 | 282 | // age is not necessarily the age now, but the age at the given check_time |
65fa5c61 | 283 | if (check_time > entry->timestamp) |
62e76326 | 284 | age = check_time - entry->timestamp; |
285 | ||
efd62b86 | 286 | // FIXME: what to do when age < 0 or counter overflow? |
b2f01ec3 | 287 | assert(age >= 0); |
efd62b86 | 288 | |
96151fc9 DD |
289 | /* We need a refresh rule. In order of preference: |
290 | * | |
291 | * 1. the rule that matches this URI by regex | |
292 | * 2. the "." rule from the config file | |
293 | * 3. the default "." rule | |
294 | */ | |
851feda6 AJ |
295 | // XXX: performance regression. c_str() reallocates |
296 | const RefreshPattern *R = (uri != nilUri) ? refreshLimits(uri.c_str()) : refreshUncompiledPattern("."); | |
65fa5c61 | 297 | if (NULL == R) |
62e76326 | 298 | R = &DefaultRefresh; |
299 | ||
95b8eae2 | 300 | debugs(22, 3, "Matched '" << R->pattern.c_str() << " " << |
bf8fe701 | 301 | (int) R->min << " " << (int) (100.0 * R->pct) << "%% " << |
302 | (int) R->max << "'"); | |
65fa5c61 | 303 | |
64f8c2cb | 304 | debugs(22, 3, "\tage:\t" << age); |
62e76326 | 305 | |
bf8fe701 | 306 | debugs(22, 3, "\tcheck_time:\t" << mkrfc1123(check_time)); |
62e76326 | 307 | |
bf8fe701 | 308 | debugs(22, 3, "\tentry->timestamp:\t" << mkrfc1123(entry->timestamp)); |
65fa5c61 | 309 | |
450fe1cb | 310 | if (request && !request->flags.ignoreCc) { |
64f8c2cb | 311 | const HttpHdrCc *const cc = request->cache_control; |
d74ad83f | 312 | if (cc && cc->hasMinFresh()) { |
4ce6e3b5 | 313 | const int32_t minFresh=cc->minFresh(); |
64f8c2cb | 314 | debugs(22, 3, "\tage + min-fresh:\t" << age << " + " << |
77da1817 | 315 | minFresh << " = " << age + minFresh); |
64f8c2cb | 316 | debugs(22, 3, "\tcheck_time + min-fresh:\t" << check_time << " + " |
422acb7f FC |
317 | << minFresh << " = " << |
318 | mkrfc1123(check_time + minFresh)); | |
319 | age += minFresh; | |
320 | check_time += minFresh; | |
64f8c2cb AR |
321 | } |
322 | } | |
323 | ||
324 | memset(&sf, '\0', sizeof(sf)); | |
325 | ||
326 | staleness = refreshStaleness(entry, check_time, age, R, &sf); | |
327 | ||
328 | debugs(22, 3, "Staleness = " << staleness); | |
329 | ||
caf65351 AJ |
330 | const auto *reply = (entry->mem_obj && entry->mem_obj->getReply() ? entry->mem_obj->getReply() : nullptr); |
331 | ||
65fd3895 | 332 | // stale-if-error requires any failure be passed thru when its period is over. |
caf65351 AJ |
333 | if (request && reply && reply->cache_control && |
334 | reply->cache_control->hasStaleIfError() && | |
335 | reply->cache_control->staleIfError() < staleness) { | |
65fd3895 | 336 | |
96151fc9 | 337 | debugs(22, 3, "stale-if-error period expired. Will produce error if validation fails."); |
e857372a | 338 | request->flags.failOnValidationError = true; |
65fd3895 AJ |
339 | } |
340 | ||
96151fc9 DD |
341 | /* If the origin server specified either of: |
342 | * Cache-Control: must-revalidate | |
343 | * Cache-Control: proxy-revalidate | |
344 | * the spec says the response must always be revalidated if stale. | |
345 | */ | |
fa83b766 EB |
346 | const bool revalidateAlways = EBIT_TEST(entry->flags, ENTRY_REVALIDATE_ALWAYS); |
347 | if (revalidateAlways || (staleness > -1 && | |
d267fa9c | 348 | EBIT_TEST(entry->flags, ENTRY_REVALIDATE_STALE))) { |
fa83b766 | 349 | debugs(22, 3, "YES: Must revalidate stale object (origin set " << |
d267fa9c SM |
350 | (revalidateAlways ? "no-cache or private" : |
351 | "must-revalidate, proxy-revalidate or s-maxage") << ")"); | |
5b1d04af | 352 | if (request) |
e857372a | 353 | request->flags.failOnValidationError = true; |
62e76326 | 354 | return STALE_MUST_REVALIDATE; |
65fa5c61 | 355 | } |
62e76326 | 356 | |
829a9357 | 357 | /* request-specific checks */ |
450fe1cb | 358 | if (request && !request->flags.ignoreCc) { |
62e76326 | 359 | HttpHdrCc *cc = request->cache_control; |
4c3ef9b2 | 360 | |
96151fc9 DD |
361 | /* If the request is an IMS request, and squid is configured NOT to service this from cache |
362 | * (either by 'refresh-ims' in the refresh pattern or 'refresh_all_ims on' globally) | |
363 | * then force a reload from the origin. | |
364 | */ | |
45e5102d | 365 | if (request->flags.ims && (R->flags.refresh_ims || Config.onoff.refresh_all_ims)) { |
96151fc9 DD |
366 | // The client's no-cache header is changed into a IMS query |
367 | debugs(22, 3, "YES: Client IMS request forcing revalidation of object (refresh-ims option)"); | |
4c3ef9b2 | 368 | return STALE_FORCED_RELOAD; |
369 | } | |
370 | ||
626096be | 371 | #if USE_HTTP_VIOLATIONS |
96151fc9 DD |
372 | /* Normally a client reload request ("Cache-Control: no-cache" or "Pragma: no-cache") |
373 | * means we must treat this reponse as STALE and fetch a new one. | |
374 | * | |
375 | * However, some options exist to override this behaviour. For example, we might just | |
376 | * revalidate our existing response, or even just serve it up without revalidating it. | |
377 | * | |
378 | * ---- Note on the meaning of nocache_hack ----- | |
379 | * | |
380 | * The nocache_hack flag has a very specific and complex meaning: | |
381 | * | |
382 | * (a) this is a reload request ("Cache-Control: no-cache" or "Pragma: no-cache" header) | |
383 | * and (b) the configuration file either has at least one refresh_pattern with | |
384 | * ignore-reload or reload-into-ims (not necessarily the rule matching this request) or | |
385 | * the global reload_into_ims is set to on | |
386 | * | |
387 | * In other words: this is a client reload, and we might need to override | |
388 | * the default behaviour (but we might not). | |
389 | * | |
390 | * "nocache_hack" is a pretty deceptive name for such a complicated meaning. | |
391 | */ | |
392 | if (request->flags.noCacheHack()) { | |
393 | ||
394 | if (R->flags.ignore_reload) { | |
395 | /* The client's no-cache header is ignored completely - we'll try to serve | |
396 | * what we have (assuming it's still fresh, etc.) | |
397 | */ | |
398 | debugs(22, 3, "MAYBE: Ignoring client reload request - trying to serve from cache (ignore-reload option)"); | |
399 | } else if (R->flags.reload_into_ims || Config.onoff.reload_into_ims) { | |
400 | /* The client's no-cache header is not honoured completely - we'll just try | |
401 | * to revalidate our cached copy (IMS to origin) instead of fetching a new | |
402 | * copy with an unconditional GET. | |
403 | */ | |
404 | debugs(22, 3, "YES: Client reload request - cheating, only revalidating with origin (reload-into-ims option)"); | |
405 | return STALE_RELOAD_INTO_IMS; | |
406 | } else { | |
407 | /* The client's no-cache header is honoured - we fetch a new copy from origin */ | |
408 | debugs(22, 3, "YES: Client reload request - fetching new copy from origin"); | |
409 | request->flags.noCache = true; | |
410 | return STALE_FORCED_RELOAD; | |
411 | } | |
62e76326 | 412 | } |
9f60cfdf | 413 | #endif |
96151fc9 DD |
414 | |
415 | // Check the Cache-Control client request header | |
62e76326 | 416 | if (NULL != cc) { |
96151fc9 DD |
417 | |
418 | // max-age directive | |
d74ad83f | 419 | if (cc->hasMaxAge()) { |
caf65351 AJ |
420 | |
421 | // draft-mcmanus-immutable-00: reply contains CC:immutable then ignore client CC:max-age=N | |
422 | if (reply && reply->cache_control && reply->cache_control->Immutable()) { | |
423 | debugs(22, 3, "MAYBE: Ignoring client CC:max-age=" << cc->maxAge() << " request - 'Cache-Control: immutable'"); | |
424 | ||
626096be | 425 | #if USE_HTTP_VIOLATIONS |
18fe96be | 426 | // Ignore of client "Cache-Control: max-age=0" header |
caf65351 | 427 | } else if (R->flags.ignore_reload && cc->maxAge() == 0) { |
96151fc9 | 428 | debugs(22, 3, "MAYBE: Ignoring client reload request - trying to serve from cache (ignore-reload option)"); |
528b2c61 | 429 | #endif |
caf65351 | 430 | |
18fe96be | 431 | // Honour client "Cache-Control: max-age=x" header |
caf65351 AJ |
432 | } else if (age > cc->maxAge() || cc->maxAge() == 0) { |
433 | debugs(22, 3, "YES: Revalidating object - client 'Cache-Control: max-age=" << cc->maxAge() << "'"); | |
434 | return STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE; | |
62e76326 | 435 | } |
436 | } | |
437 | ||
96151fc9 | 438 | // max-stale directive |
d74ad83f FC |
439 | if (cc->hasMaxStale() && staleness > -1) { |
440 | if (cc->maxStale()==HttpHdrCc::MAX_STALE_ANY) { | |
96151fc9 | 441 | debugs(22, 3, "NO: Client accepts a stale response of any age - 'Cache-Control: max-stale'"); |
62e76326 | 442 | return FRESH_REQUEST_MAX_STALE_ALL; |
4ce6e3b5 | 443 | } else if (staleness < cc->maxStale()) { |
96151fc9 | 444 | debugs(22, 3, "NO: Client accepts a stale response - 'Cache-Control: max-stale=" << cc->maxStale() << "'"); |
62e76326 | 445 | return FRESH_REQUEST_MAX_STALE_VALUE; |
446 | } | |
447 | } | |
448 | } | |
48f44632 | 449 | } |
62e76326 | 450 | |
96151fc9 | 451 | // If the object is fresh, return the right FRESH_ code |
65fa5c61 | 452 | if (-1 == staleness) { |
96151fc9 | 453 | debugs(22, 3, "Object isn't stale.."); |
ed1de692 | 454 | if (sf.expires) { |
96151fc9 | 455 | debugs(22, 3, "returning FRESH_EXPIRES"); |
62e76326 | 456 | return FRESH_EXPIRES; |
26ac0430 | 457 | } |
62e76326 | 458 | |
459 | assert(!sf.max); | |
460 | ||
ed1de692 | 461 | if (sf.lmfactor) { |
96151fc9 | 462 | debugs(22, 3, "returning FRESH_LMFACTOR_RULE"); |
62e76326 | 463 | return FRESH_LMFACTOR_RULE; |
26ac0430 | 464 | } |
62e76326 | 465 | |
466 | assert(sf.min); | |
467 | ||
96151fc9 | 468 | debugs(22, 3, "returning FRESH_MIN_RULE"); |
62e76326 | 469 | return FRESH_MIN_RULE; |
1dfa1d81 | 470 | } |
62e76326 | 471 | |
65fa5c61 | 472 | /* |
473 | * At this point the response is stale, unless one of | |
542c4d60 | 474 | * the override options kicks in. |
570d3f75 | 475 | * NOTE: max-stale config blocks the overrides. |
65fa5c61 | 476 | */ |
570d3f75 | 477 | int max_stale = (R->max_stale >= 0 ? R->max_stale : Config.maxStale); |
60c3d5b7 | 478 | if ( max_stale >= 0 && staleness > max_stale) { |
96151fc9 | 479 | debugs(22, 3, "YES: refresh_pattern max-stale=N limit from squid.conf"); |
570d3f75 | 480 | if (request) |
e857372a | 481 | request->flags.failOnValidationError = true; |
570d3f75 AJ |
482 | return STALE_MAX_STALE; |
483 | } | |
484 | ||
65fa5c61 | 485 | if (sf.expires) { |
626096be | 486 | #if USE_HTTP_VIOLATIONS |
62e76326 | 487 | |
488 | if (R->flags.override_expire && age < R->min) { | |
96151fc9 | 489 | debugs(22, 3, "NO: Serving from cache - even though explicit expiry has passed, we enforce Min value (override-expire option)"); |
62e76326 | 490 | return FRESH_OVERRIDE_EXPIRES; |
491 | } | |
492 | ||
65fa5c61 | 493 | #endif |
62e76326 | 494 | return STALE_EXPIRES; |
e4e6a8db | 495 | } |
62e76326 | 496 | |
65fa5c61 | 497 | if (sf.max) |
62e76326 | 498 | return STALE_MAX_RULE; |
499 | ||
65fa5c61 | 500 | if (sf.lmfactor) { |
626096be | 501 | #if USE_HTTP_VIOLATIONS |
62e76326 | 502 | if (R->flags.override_lastmod && age < R->min) { |
96151fc9 | 503 | debugs(22, 3, "NO: Serving from cache - even though L-M factor says the object is stale, we enforce Min value (override-lastmod option)"); |
62e76326 | 504 | return FRESH_OVERRIDE_LASTMOD; |
505 | } | |
65fa5c61 | 506 | #endif |
96151fc9 | 507 | debugs(22, 3, "YES: L-M factor says the object is stale'"); |
62e76326 | 508 | return STALE_LMFACTOR_RULE; |
e4e6a8db | 509 | } |
62e76326 | 510 | |
96151fc9 | 511 | debugs(22, 3, "returning STALE_DEFAULT"); |
65fa5c61 | 512 | return STALE_DEFAULT; |
e4e6a8db | 513 | } |
48f44632 | 514 | |
96151fc9 DD |
515 | /** |
516 | * This is called by http.cc once it has received and parsed the origin server's | |
517 | * response headers. It uses the result as part of its algorithm to decide whether a | |
518 | * response should be cached. | |
519 | * | |
520 | * \retval true if the entry is cacheable, regardless of whether FRESH or STALE | |
521 | * \retval false if the entry is not cacheable | |
522 | * | |
523 | * TODO: this algorithm seems a bit odd and might not be quite right. Verify against HTTPbis. | |
524 | */ | |
525 | bool | |
cfa9f1cb | 526 | refreshIsCachable(const StoreEntry * entry) |
527 | { | |
528 | /* | |
529 | * Don't look at the request to avoid no-cache and other nuisances. | |
530 | * the object should have a mem_obj so the URL will be found there. | |
26ac0430 AJ |
531 | * minimum_expiry_time seconds delta (defaults to 60 seconds), to |
532 | * avoid objects which expire almost immediately, and which can't | |
6a2f3fcf | 533 | * be refreshed. |
cfa9f1cb | 534 | */ |
6a2f3fcf | 535 | int reason = refreshCheck(entry, NULL, Config.minimum_expiry_time); |
5db6bf73 FC |
536 | ++ refreshCounts[rcStore].total; |
537 | ++ refreshCounts[rcStore].status[reason]; | |
62e76326 | 538 | |
451c8350 | 539 | if (reason < STALE_MUST_REVALIDATE) |
62e76326 | 540 | /* Does not need refresh. This is certainly cachable */ |
96151fc9 | 541 | return true; |
62e76326 | 542 | |
438b41ba EB |
543 | if (entry->lastModified() < 0) |
544 | /* We should know entry's modification time to do a refresh */ | |
96151fc9 | 545 | return false; |
62e76326 | 546 | |
cfa9f1cb | 547 | if (entry->mem_obj == NULL) |
62e76326 | 548 | /* no mem_obj? */ |
96151fc9 | 549 | return true; |
62e76326 | 550 | |
528b2c61 | 551 | if (entry->getReply() == NULL) |
62e76326 | 552 | /* no reply? */ |
96151fc9 | 553 | return true; |
62e76326 | 554 | |
528b2c61 | 555 | if (entry->getReply()->content_length == 0) |
62e76326 | 556 | /* No use refreshing (caching?) 0 byte objects */ |
96151fc9 | 557 | return false; |
62e76326 | 558 | |
cfa9f1cb | 559 | /* This seems to be refreshable. Cache it */ |
96151fc9 | 560 | return true; |
cfa9f1cb | 561 | } |
562 | ||
bcfba8bd AR |
563 | /// whether reply is stale if it is a hit |
564 | static bool | |
565 | refreshIsStaleIfHit(const int reason) | |
566 | { | |
567 | switch (reason) { | |
568 | case FRESH_MIN_RULE: | |
569 | case FRESH_LMFACTOR_RULE: | |
570 | case FRESH_EXPIRES: | |
571 | return false; | |
572 | default: | |
573 | return true; | |
574 | } | |
575 | } | |
576 | ||
96151fc9 DD |
577 | /** |
578 | * Protocol-specific wrapper around refreshCheck() function. | |
579 | * | |
580 | * Note the reason for STALE/FRESH then return true/false respectively. | |
581 | * | |
582 | * \retval 1 if STALE | |
583 | * \retval 0 if FRESH | |
584 | */ | |
829a9357 | 585 | int |
190154cf | 586 | refreshCheckHTTP(const StoreEntry * entry, HttpRequest * request) |
7d47d8e6 | 587 | { |
65fa5c61 | 588 | int reason = refreshCheck(entry, request, 0); |
5db6bf73 FC |
589 | ++ refreshCounts[rcHTTP].total; |
590 | ++ refreshCounts[rcHTTP].status[reason]; | |
450fe1cb | 591 | request->flags.staleIfHit = refreshIsStaleIfHit(reason); |
bcfba8bd | 592 | return (Config.onoff.offline || reason < 200) ? 0 : 1; |
829a9357 | 593 | } |
594 | ||
96151fc9 | 595 | /// \see int refreshCheckHTTP(const StoreEntry * entry, HttpRequest * request) |
829a9357 | 596 | int |
190154cf | 597 | refreshCheckICP(const StoreEntry * entry, HttpRequest * request) |
7d47d8e6 | 598 | { |
65fa5c61 | 599 | int reason = refreshCheck(entry, request, 30); |
5db6bf73 FC |
600 | ++ refreshCounts[rcICP].total; |
601 | ++ refreshCounts[rcICP].status[reason]; | |
65fa5c61 | 602 | return (reason < 200) ? 0 : 1; |
829a9357 | 603 | } |
604 | ||
65fa5c61 | 605 | #if USE_HTCP |
96151fc9 | 606 | /// \see int refreshCheckHTTP(const StoreEntry * entry, HttpRequest * request) |
32b3cf93 | 607 | int |
190154cf | 608 | refreshCheckHTCP(const StoreEntry * entry, HttpRequest * request) |
32b3cf93 | 609 | { |
65fa5c61 | 610 | int reason = refreshCheck(entry, request, 10); |
5db6bf73 FC |
611 | ++ refreshCounts[rcHTCP].total; |
612 | ++ refreshCounts[rcHTCP].status[reason]; | |
65fa5c61 | 613 | return (reason < 200) ? 0 : 1; |
32b3cf93 | 614 | } |
62e76326 | 615 | |
65fa5c61 | 616 | #endif |
32b3cf93 | 617 | |
65fa5c61 | 618 | #if USE_CACHE_DIGESTS |
96151fc9 | 619 | /// \see int refreshCheckHTTP(const StoreEntry * entry, HttpRequest * request) |
829a9357 | 620 | int |
7d47d8e6 | 621 | refreshCheckDigest(const StoreEntry * entry, time_t delta) |
622 | { | |
65fa5c61 | 623 | int reason = refreshCheck(entry, |
62e76326 | 624 | entry->mem_obj ? entry->mem_obj->request : NULL, |
625 | delta); | |
5db6bf73 FC |
626 | ++ refreshCounts[rcCDigest].total; |
627 | ++ refreshCounts[rcCDigest].status[reason]; | |
65fa5c61 | 628 | return (reason < 200) ? 0 : 1; |
6018f0de | 629 | } |
65fa5c61 | 630 | #endif |
6018f0de | 631 | |
96151fc9 DD |
632 | /** |
633 | * Get the configured maximum caching time for objects with this URL | |
634 | * according to refresh_pattern. | |
635 | * | |
636 | * Used by http.cc when generating a upstream requests to ensure that | |
637 | * responses it is given are fresh enough to be worth caching. | |
638 | * | |
639 | * \retval pattern-max if there is a refresh_pattern matching the URL configured. | |
640 | * \retval REFRESH_DEFAULT_MAX if there are no explicit limits configured | |
641 | */ | |
48f44632 | 642 | time_t |
643 | getMaxAge(const char *url) | |
644 | { | |
8d9a8184 | 645 | const RefreshPattern *R; |
bf8fe701 | 646 | debugs(22, 3, "getMaxAge: '" << url << "'"); |
62e76326 | 647 | |
6018f0de | 648 | if ((R = refreshLimits(url))) |
62e76326 | 649 | return R->max; |
6018f0de | 650 | else |
62e76326 | 651 | return REFRESH_DEFAULT_MAX; |
48f44632 | 652 | } |
1c3e77cd | 653 | |
4fb971a0 AJ |
654 | static int |
655 | refreshCountsStatsEntry(StoreEntry * sentry, struct RefreshCounts &rc, int code, const char *desc) | |
656 | { | |
657 | storeAppendPrintf(sentry, "%6d\t%6.2f\t%s\n", rc.status[code], xpercent(rc.status[code], rc.total), desc); | |
658 | return rc.status[code]; | |
659 | } | |
62e76326 | 660 | |
4fb971a0 AJ |
661 | static void |
662 | refreshCountsStats(StoreEntry * sentry, struct RefreshCounts &rc) | |
829a9357 | 663 | { |
4fb971a0 AJ |
664 | if (!rc.total) |
665 | return; | |
cc7cfa8e | 666 | |
4fb971a0 | 667 | storeAppendPrintf(sentry, "\n\n%s histogram:\n", rc.proto); |
65fa5c61 | 668 | storeAppendPrintf(sentry, "Count\t%%Total\tCategory\n"); |
829a9357 | 669 | |
4fb971a0 AJ |
670 | int sum = 0; |
671 | sum += refreshCountsStatsEntry(sentry, rc, FRESH_REQUEST_MAX_STALE_ALL, "Fresh: request max-stale wildcard"); | |
672 | sum += refreshCountsStatsEntry(sentry, rc, FRESH_REQUEST_MAX_STALE_VALUE, "Fresh: request max-stale value"); | |
673 | sum += refreshCountsStatsEntry(sentry, rc, FRESH_EXPIRES, "Fresh: expires time not reached"); | |
674 | sum += refreshCountsStatsEntry(sentry, rc, FRESH_LMFACTOR_RULE, "Fresh: refresh_pattern last-mod factor percentage"); | |
675 | sum += refreshCountsStatsEntry(sentry, rc, FRESH_MIN_RULE, "Fresh: refresh_pattern min value"); | |
96151fc9 DD |
676 | sum += refreshCountsStatsEntry(sentry, rc, FRESH_OVERRIDE_EXPIRES, "Fresh: refresh_pattern override-expires"); |
677 | sum += refreshCountsStatsEntry(sentry, rc, FRESH_OVERRIDE_LASTMOD, "Fresh: refresh_pattern override-lastmod"); | |
4fb971a0 AJ |
678 | sum += refreshCountsStatsEntry(sentry, rc, STALE_MUST_REVALIDATE, "Stale: response has must-revalidate"); |
679 | sum += refreshCountsStatsEntry(sentry, rc, STALE_RELOAD_INTO_IMS, "Stale: changed reload into IMS"); | |
680 | sum += refreshCountsStatsEntry(sentry, rc, STALE_FORCED_RELOAD, "Stale: request has no-cache directive"); | |
681 | sum += refreshCountsStatsEntry(sentry, rc, STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE, "Stale: age exceeds request max-age value"); | |
682 | sum += refreshCountsStatsEntry(sentry, rc, STALE_EXPIRES, "Stale: expires time reached"); | |
683 | sum += refreshCountsStatsEntry(sentry, rc, STALE_MAX_RULE, "Stale: refresh_pattern max age rule"); | |
684 | sum += refreshCountsStatsEntry(sentry, rc, STALE_LMFACTOR_RULE, "Stale: refresh_pattern last-mod factor percentage"); | |
685 | sum += refreshCountsStatsEntry(sentry, rc, STALE_DEFAULT, "Stale: by default"); | |
62e76326 | 686 | storeAppendPrintf(sentry, "\n"); |
829a9357 | 687 | } |
688 | ||
1c3e77cd | 689 | static void |
690 | refreshStats(StoreEntry * sentry) | |
691 | { | |
a5ea7751 AJ |
692 | // display per-rule counts of usage and tests |
693 | storeAppendPrintf(sentry, "\nRefresh pattern usage:\n\n"); | |
694 | storeAppendPrintf(sentry, " Used \tChecks \t%% Matches\tPattern\n"); | |
695 | for (const RefreshPattern *R = Config.Refresh; R; R = R->next) { | |
696 | storeAppendPrintf(sentry, " %10" PRIu64 "\t%10" PRIu64 "\t%6.2f\t%s%s\n", | |
697 | R->stats.matchCount, | |
698 | R->stats.matchTests, | |
699 | xpercent(R->stats.matchCount, R->stats.matchTests), | |
c2afddd8 | 700 | (R->pattern.flags®_ICASE ? "-i " : ""), |
95b8eae2 | 701 | R->pattern.c_str()); |
a5ea7751 AJ |
702 | } |
703 | ||
829a9357 | 704 | int i; |
705 | int total = 0; | |
706 | ||
707 | /* get total usage count */ | |
62e76326 | 708 | |
829a9357 | 709 | for (i = 0; i < rcCount; ++i) |
62e76326 | 710 | total += refreshCounts[i].total; |
829a9357 | 711 | |
712 | /* protocol usage histogram */ | |
713 | storeAppendPrintf(sentry, "\nRefreshCheck calls per protocol\n\n"); | |
62e76326 | 714 | |
829a9357 | 715 | storeAppendPrintf(sentry, "Protocol\t#Calls\t%%Calls\n"); |
62e76326 | 716 | |
829a9357 | 717 | for (i = 0; i < rcCount; ++i) |
62e76326 | 718 | storeAppendPrintf(sentry, "%10s\t%6d\t%6.2f\n", |
719 | refreshCounts[i].proto, | |
720 | refreshCounts[i].total, | |
721 | xpercent(refreshCounts[i].total, total)); | |
829a9357 | 722 | |
723 | /* per protocol histograms */ | |
724 | storeAppendPrintf(sentry, "\n\nRefreshCheck histograms for various protocols\n"); | |
62e76326 | 725 | |
829a9357 | 726 | for (i = 0; i < rcCount; ++i) |
4fb971a0 | 727 | refreshCountsStats(sentry, refreshCounts[i]); |
1c3e77cd | 728 | } |
729 | ||
5f5e883f FC |
730 | static void |
731 | refreshRegisterWithCacheManager(void) | |
732 | { | |
8822ebee | 733 | Mgr::RegisterAction("refresh", "Refresh Algorithm Statistics", refreshStats, 0, 1); |
5f5e883f FC |
734 | } |
735 | ||
1c3e77cd | 736 | void |
9bc73deb | 737 | refreshInit(void) |
1c3e77cd | 738 | { |
829a9357 | 739 | memset(refreshCounts, 0, sizeof(refreshCounts)); |
740 | refreshCounts[rcHTTP].proto = "HTTP"; | |
741 | refreshCounts[rcICP].proto = "ICP"; | |
65fa5c61 | 742 | #if USE_HTCP |
62e76326 | 743 | |
32b3cf93 | 744 | refreshCounts[rcHTCP].proto = "HTCP"; |
65fa5c61 | 745 | #endif |
62e76326 | 746 | |
cfa9f1cb | 747 | refreshCounts[rcStore].proto = "On Store"; |
65fa5c61 | 748 | #if USE_CACHE_DIGESTS |
62e76326 | 749 | |
829a9357 | 750 | refreshCounts[rcCDigest].proto = "Cache Digests"; |
65fa5c61 | 751 | #endif |
62e76326 | 752 | |
d120ed12 | 753 | refreshRegisterWithCacheManager(); |
1c3e77cd | 754 | } |
f53969cc | 755 |