Hello,
This patch forces Squid to always revalidate Cache-Control:no-cache
responses.
Squid MUST NOT use a CC:no-cache response for satisfying subsequent
requests without successful validation with the origin server. Squid
violated this MUST because Squid mapped both "no-cache" and
"must-revalidate"/etc. directives to the same ENTRY_REVALIDATE flag
which was interpreted as "revalidate when the cached response becomes
stale" rather than "revalidate on every request".
This patch splits ENTRY_REVALIDATE into:
- ENTRY_REVALIDATE_ALWAYS, for entries with CC:no-cache and
- ENTRY_REVALIDATE_STALE, for entries with other related CC directives
like CC:must-revalidate and CC:proxy-revalidate.
Reusing ENTRY_CACHABLE_RESERVED_FOR_FUTURE_USE value for the more
forgiving ENTRY_REVALIDATE_STALE (instead of the more aggressive
ENTRY_REVALIDATE_ALWAYS) fixes the bug for the already cached entries -
they will be revalidated and stored with the correct flag on the next
request.
Regards,
Eduard.
MUST always revalidate Cache-Control:no-cache responses.
Squid MUST NOT use a CC:no-cache response for satisfying subsequent
requests without successful validation with the origin server. Squid
violated this MUST because Squid mapped both "no-cache" and
"must-revalidate"/etc. directives to the same ENTRY_REVALIDATE flag
which was interpreted as "revalidate when the cached response becomes
stale" rather than "revalidate on every request".
This patch splits ENTRY_REVALIDATE into:
- ENTRY_REVALIDATE_ALWAYS, for entries with CC:no-cache and
- ENTRY_REVALIDATE_STALE, for entries with other related CC directives
like CC:must-revalidate and CC:proxy-revalidate.
Reusing ENTRY_CACHABLE_RESERVED_FOR_FUTURE_USE value for the more
forgiving ENTRY_REVALIDATE_STALE (instead of the more aggressive
ENTRY_REVALIDATE_ALWAYS) fixes the bug for the already cached entries -
they will be revalidated and stored with the correct flag on the next
request.
=== modified file 'src/enums.h'
--- src/enums.h 2016-04-01 17:54:10 +0000
+++ src/enums.h 2016-09-02 21:17:57 +0000
@@ -40,65 +40,65 @@
PING_NONE,
PING_WAITING,
PING_DONE
} ping_status_t;
typedef enum {
STORE_OK,
STORE_PENDING
} store_status_t;
typedef enum {
SWAPOUT_NONE,
SWAPOUT_WRITING,
SWAPOUT_DONE
} swap_status_t;
typedef enum {
STORE_NON_CLIENT,
STORE_MEM_CLIENT,
STORE_DISK_CLIENT
} store_client_t;
/*
* These are for StoreEntry->flag, which is defined as a SHORT
*
* NOTE: These flags are written to swap.state, so think very carefully
* about deleting or re-assigning!
*/
enum {
ENTRY_SPECIAL,
- ENTRY_REVALIDATE,
+ ENTRY_REVALIDATE_ALWAYS,
DELAY_SENDING,
RELEASE_REQUEST,
REFRESH_REQUEST,
- ENTRY_CACHABLE_RESERVED_FOR_FUTURE_USE,
+ ENTRY_REVALIDATE_STALE,
ENTRY_DISPATCHED,
KEY_PRIVATE,
ENTRY_FWD_HDR_WAIT,
ENTRY_NEGCACHED,
ENTRY_VALIDATED,
ENTRY_BAD_LENGTH,
ENTRY_ABORTED
};
/*
* These are for client Streams. Each node in the stream can be queried for
* its status
*/
typedef enum {
STREAM_NONE, /* No particular status */
STREAM_COMPLETE, /* All data has been flushed, no more reads allowed */
/* an unpredicted end has occured, no more
* reads occured, but no need to tell
* downstream that an error occured
*/
STREAM_UNPLANNED_COMPLETE,
/* An error has occured in this node or an above one,
* and the node is not generating an error body / it's
* midstream
*/
STREAM_FAILED
} clientStream_status_t;
/* stateful helper callback response codes */
typedef enum {
=== modified file 'src/http.cc'
--- src/http.cc 2016-08-15 11:26:37 +0000
+++ src/http.cc 2016-09-02 19:44:34 +0000
@@ -961,72 +961,74 @@
if (Config.negativeTtl > 0)
entry->cacheNegatively();
else
#endif
entry->makePrivate();
break;
default:
assert(0);
break;
}
}
if (!ignoreCacheControl) {
if (rep->cache_control) {
// We are required to revalidate on many conditions.
// For security reasons we do so even if storage was caused by refresh_pattern ignore-* option
// CC:must-revalidate or CC:proxy-revalidate
const bool ccMustRevalidate = (rep->cache_control->proxyRevalidate() || rep->cache_control->mustRevalidate());
// CC:no-cache (only if there are no parameters)
const bool ccNoCacheNoParams = (rep->cache_control->hasNoCache() && rep->cache_control->noCache().size()==0);
// CC:s-maxage=N
const bool ccSMaxAge = rep->cache_control->hasSMaxAge();
// CC:private (yes, these can sometimes be stored)
const bool ccPrivate = rep->cache_control->hasPrivate();
- if (ccMustRevalidate || ccNoCacheNoParams || ccSMaxAge || ccPrivate)
- EBIT_SET(entry->flags, ENTRY_REVALIDATE);
+ if (ccNoCacheNoParams)
+ EBIT_SET(entry->flags, ENTRY_REVALIDATE_ALWAYS);
+ else if (ccMustRevalidate || ccSMaxAge || ccPrivate)
+ EBIT_SET(entry->flags, ENTRY_REVALIDATE_STALE);
}
#if USE_HTTP_VIOLATIONS // response header Pragma::no-cache is undefined in HTTP
else {
// Expensive calculation. So only do it IF the CC: header is not present.
/* HACK: Pragma: no-cache in _replies_ is not documented in HTTP,
* but servers like "Active Imaging Webcast/2.0" sure do use it */
if (rep->header.has(Http::HdrType::PRAGMA) &&
rep->header.hasListMember(Http::HdrType::PRAGMA,"no-cache",','))
- EBIT_SET(entry->flags, ENTRY_REVALIDATE);
+ EBIT_SET(entry->flags, ENTRY_REVALIDATE_ALWAYS);
}
#endif
}
#if HEADERS_LOG
headersLog(1, 0, request->method, rep);
#endif
ctx_exit(ctx);
}
HttpStateData::ConnectionStatus
HttpStateData::statusIfComplete() const
{
const HttpReply *rep = virginReply();
/** \par
* If the reply wants to close the connection, it takes precedence */
if (httpHeaderHasConnDir(&rep->header, "close"))
return COMPLETE_NONPERSISTENT_MSG;
/** \par
* If we didn't send a keep-alive request header, then this
* can not be a persistent connection.
*/
if (!flags.keepalive)
return COMPLETE_NONPERSISTENT_MSG;
/** \par
=== modified file 'src/refresh.cc'
--- src/refresh.cc 2016-01-01 00:12:18 +0000
+++ src/refresh.cc 2016-09-02 21:33:19 +0000
@@ -319,62 +319,66 @@
debugs(22, 3, "\tage + min-fresh:\t" << age << " + " <<
minFresh << " = " << age + minFresh);
debugs(22, 3, "\tcheck_time + min-fresh:\t" << check_time << " + "
<< minFresh << " = " <<
mkrfc1123(check_time + minFresh));
age += minFresh;
check_time += minFresh;
}
}
memset(&sf, '\0', sizeof(sf));
staleness = refreshStaleness(entry, check_time, age, R, &sf);
debugs(22, 3, "Staleness = " << staleness);
// stale-if-error requires any failure be passed thru when its period is over.
if (request && entry->mem_obj && entry->mem_obj->getReply() && entry->mem_obj->getReply()->cache_control &&
entry->mem_obj->getReply()->cache_control->hasStaleIfError() &&
entry->mem_obj->getReply()->cache_control->staleIfError() < staleness) {
debugs(22, 3, "stale-if-error period expired. Will produce error if validation fails.");
request->flags.failOnValidationError = true;
}
/* If the origin server specified either of:
* Cache-Control: must-revalidate
* Cache-Control: proxy-revalidate
* the spec says the response must always be revalidated if stale.
*/
- if (EBIT_TEST(entry->flags, ENTRY_REVALIDATE) && staleness > -1) {
- debugs(22, 3, "YES: Must revalidate stale object (origin set must-revalidate, proxy-revalidate, no-cache, s-maxage, or private)");
+ const bool revalidateAlways = EBIT_TEST(entry->flags, ENTRY_REVALIDATE_ALWAYS);
+ if (revalidateAlways || (staleness > -1 &&
+ EBIT_TEST(entry->flags, ENTRY_REVALIDATE_STALE))) {
+ debugs(22, 3, "YES: Must revalidate stale object (origin set " <<
+ (revalidateAlways ? "no-cache" :
+ "must-revalidate, proxy-revalidate, s-maxage, or private") << ")");
if (request)
request->flags.failOnValidationError = true;
return STALE_MUST_REVALIDATE;
}
/* request-specific checks */
if (request && !request->flags.ignoreCc) {
HttpHdrCc *cc = request->cache_control;
/* If the request is an IMS request, and squid is configured NOT to service this from cache
* (either by 'refresh-ims' in the refresh pattern or 'refresh_all_ims on' globally)
* then force a reload from the origin.
*/
if (request->flags.ims && (R->flags.refresh_ims || Config.onoff.refresh_all_ims)) {
// The client's no-cache header is changed into a IMS query
debugs(22, 3, "YES: Client IMS request forcing revalidation of object (refresh-ims option)");
return STALE_FORCED_RELOAD;
}
#if USE_HTTP_VIOLATIONS
/* Normally a client reload request ("Cache-Control: no-cache" or "Pragma: no-cache")
* means we must treat this reponse as STALE and fetch a new one.
*
* However, some options exist to override this behaviour. For example, we might just
* revalidate our existing response, or even just serve it up without revalidating it.
*
* ---- Note on the meaning of nocache_hack -----
*
* The nocache_hack flag has a very specific and complex meaning:
*
=== modified file 'src/stat.cc'
--- src/stat.cc 2016-01-31 12:05:30 +0000
+++ src/stat.cc 2016-09-02 21:19:58 +0000
@@ -261,72 +261,75 @@
stats.gopher_read_hist[i],
Math::doublePercent(stats.gopher_read_hist[i], stats.gopher_reads));
}
storeAppendPrintf(sentry, "\n");
}
static const char *
describeStatuses(const StoreEntry * entry)
{
LOCAL_ARRAY(char, buf, 256);
snprintf(buf, 256, "%-13s %-13s %-12s %-12s",
storeStatusStr[entry->store_status],
memStatusStr[entry->mem_status],
swapStatusStr[entry->swap_status],
pingStatusStr[entry->ping_status]);
return buf;
}
const char *
storeEntryFlags(const StoreEntry * entry)
{
LOCAL_ARRAY(char, buf, 256);
int flags = (int) entry->flags;
char *t;
buf[0] = '\0';
if (EBIT_TEST(flags, ENTRY_SPECIAL))
strcat(buf, "SPECIAL,");
- if (EBIT_TEST(flags, ENTRY_REVALIDATE))
- strcat(buf, "REVALIDATE,");
+ if (EBIT_TEST(flags, ENTRY_REVALIDATE_ALWAYS))
+ strcat(buf, "REVALIDATE_ALWAYS,");
if (EBIT_TEST(flags, DELAY_SENDING))
strcat(buf, "DELAY_SENDING,");
if (EBIT_TEST(flags, RELEASE_REQUEST))
strcat(buf, "RELEASE_REQUEST,");
if (EBIT_TEST(flags, REFRESH_REQUEST))
strcat(buf, "REFRESH_REQUEST,");
+ if (EBIT_TEST(flags, ENTRY_REVALIDATE_STALE))
+ strcat(buf, "REVALIDATE_STALE,");
+
if (EBIT_TEST(flags, ENTRY_DISPATCHED))
strcat(buf, "DISPATCHED,");
if (EBIT_TEST(flags, KEY_PRIVATE))
strcat(buf, "PRIVATE,");
if (EBIT_TEST(flags, ENTRY_FWD_HDR_WAIT))
strcat(buf, "FWD_HDR_WAIT,");
if (EBIT_TEST(flags, ENTRY_NEGCACHED))
strcat(buf, "NEGCACHED,");
if (EBIT_TEST(flags, ENTRY_VALIDATED))
strcat(buf, "VALIDATED,");
if (EBIT_TEST(flags, ENTRY_BAD_LENGTH))
strcat(buf, "BAD_LENGTH,");
if (EBIT_TEST(flags, ENTRY_ABORTED))
strcat(buf, "ABORTED,");
if ((t = strrchr(buf, ',')))
*t = '\0';
return buf;
}
static const char *
describeTimestamps(const StoreEntry * entry)
{
=== modified file 'src/store.cc'
--- src/store.cc 2016-07-23 13:36:56 +0000
+++ src/store.cc 2016-09-02 21:18:16 +0000
@@ -2071,64 +2071,65 @@
std::ostream &operator <<(std::ostream &os, const StoreEntry &e)
{
os << "e:";
if (e.mem_obj) {
if (e.mem_obj->xitTable.index > -1)
os << 't' << e.mem_obj->xitTable.index;
if (e.mem_obj->memCache.index > -1)
os << 'm' << e.mem_obj->memCache.index;
}
if (e.swap_filen > -1 || e.swap_dirn > -1)
os << 'd' << e.swap_filen << '@' << e.swap_dirn;
os << '=';
// print only non-default status values, using unique letters
if (e.mem_status != NOT_IN_MEMORY ||
e.store_status != STORE_PENDING ||
e.swap_status != SWAPOUT_NONE ||
e.ping_status != PING_NONE) {
if (e.mem_status != NOT_IN_MEMORY) os << 'm';
if (e.store_status != STORE_PENDING) os << 's';
if (e.swap_status != SWAPOUT_NONE) os << 'w' << e.swap_status;
if (e.ping_status != PING_NONE) os << 'p' << e.ping_status;
}
// print only set flags, using unique letters
if (e.flags) {
if (EBIT_TEST(e.flags, ENTRY_SPECIAL)) os << 'S';
- if (EBIT_TEST(e.flags, ENTRY_REVALIDATE)) os << 'R';
+ if (EBIT_TEST(e.flags, ENTRY_REVALIDATE_ALWAYS)) os << 'R';
if (EBIT_TEST(e.flags, DELAY_SENDING)) os << 'P';
if (EBIT_TEST(e.flags, RELEASE_REQUEST)) os << 'X';
if (EBIT_TEST(e.flags, REFRESH_REQUEST)) os << 'F';
+ if (EBIT_TEST(e.flags, ENTRY_REVALIDATE_STALE)) os << 'E';
if (EBIT_TEST(e.flags, ENTRY_DISPATCHED)) os << 'D';
if (EBIT_TEST(e.flags, KEY_PRIVATE)) os << 'I';
if (EBIT_TEST(e.flags, ENTRY_FWD_HDR_WAIT)) os << 'W';
if (EBIT_TEST(e.flags, ENTRY_NEGCACHED)) os << 'N';
if (EBIT_TEST(e.flags, ENTRY_VALIDATED)) os << 'V';
if (EBIT_TEST(e.flags, ENTRY_BAD_LENGTH)) os << 'L';
if (EBIT_TEST(e.flags, ENTRY_ABORTED)) os << 'A';
}
if (e.mem_obj && e.mem_obj->smpCollapsed)
os << 'O';
return os << '/' << &e << '*' << e.locks();
}
/* NullStoreEntry */
NullStoreEntry NullStoreEntry::_instance;
NullStoreEntry *
NullStoreEntry::getInstance()
{
return &_instance;
}
char const *
NullStoreEntry::getMD5Text() const
{
return "N/A";
}
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