However, pinger only drops setuid/setgid, and won't drop capabilities
after sockets are opened (when it is setuid-root, setuid(getuid()) also
drops capabilities, no code changes necessary; however, if it is only
setcap'ed, setuid() is no-op).
Fix is minimally tested, seems to work fine with both/either `setcap`
and `chmod u+s`; non-linux/non-libcap configurations should not be
affected).
Nathan Hoad [Fri, 25 Mar 2016 13:03:30 +0000 (02:03 +1300)]
Fix memory leak of AccessLogentry::url
... created by ACLFilledChecklist::syncAle().
::syncAle() is the only place in the codebase that assigns a URL that
AccessLogEntry is expected to free(), which AccessLogEntry doesn't do.
This results in a memory leak.
Alex Rousskov [Thu, 24 Mar 2016 17:02:25 +0000 (11:02 -0600)]
Added shared_memory_locking configuration directive to control mlock(2).
Locking shared memory at startup avoids SIGBUS crashes when kernel runs
out of RAM during runtime. Why not enable it by default? Unfortunately,
locking requires privileges and/or much-higher-than-default
RLIMIT_MEMLOCK limits. Thus, requiring locked memory by default is
likely to cause too many complaints, especially since Squid has not
required that before. The default is off, at least for now.
As we gain more experience, we may try to enable locking by default
while making default locking failures non-fatal and warning about
significant [accumulated] locking delays.
Bug description:
- The client side and server side are finished
- On server side the Ftp::Relay::finalizeDataDownload() is called and
schedules the Ftp::Server::originDataCompletionCheckpoint
- On client side the "Ftp::Server::userDataCompletionCheckpoint" is
called. This is schedules a write to control connection and closes
data connection.
- The Ftp::Server::originDataCompletionCheckpoint is called which is
trying to write to control connection and the assertion triggered.
This bug is an corner case, where the client-side (FTP::Server) should
wait for the server side (Ftp::Client/Ftp::Relay) to finish its job before
respond to the FTP client. In this bug the existing mechanism, designed
to handle such problems, did not worked correctly and resulted to a double
write response to the client.
This patch try to fix the existing mechanism as follows:
- When Ftp::Server receives a "startWaitingForOrigin" callback, postpones
writting possible responses to the client and keeps waiting for the
stopWaitingForOrigin callback
- When the Ftp::Server receives a "stopWaitingForOrigin" callback,
resumes any postponed response.
- When the Ftp::Client starts working on a DATA-related transaction, calls the
Ftp::Server::startWaitingForOrigin callback
- When the Ftp::Client finishes its job or when its abort abnormaly, checks
whether it needs to call Ftp::Server::stopWaitingForOrigin callback.
- Also this patch try to fix the status code returned to the FTP client
taking in account the status code returned by FTP server. The
"Ftp::Server::stopWaitingForOrigin" is used to pass the returned status code
to the client side.
Author: Eduard Bagdasaryan <eduard.bagdasaryan@measurement-factory.com>
Added ACL-driven server_pconn_for_nonretriable squid.conf directive.
This directive provides fine-grained control over persistent connection
reuse when forwarding HTTP requests that Squid cannot retry. It is
useful in environments where opening new connections is very expensive
and race conditions associated with persistent connections are very rare
and/or only cause minor problems.
Alex Rousskov [Sat, 12 Mar 2016 18:40:29 +0000 (11:40 -0700)]
Trying to avoid "looser throw specifier" error with Wheezy GCC.
AFAICT, the default CbdataParent destructor gets implicit
"noexcept(true)" specifier (because the default destructor does not
throw itself, and CbdataParent has no data members or parents that could
have contributed potentially throwing destructors). The AsyncJob child
uses a lot of things that might throw during destruction (the compiler
cannot tell for sure because we do not use noexcept specifiers). Thus,
the compiler has to use "noexcept(false)" specifier for ~AsyncJob, which
is "looser" that "noexcept(true)" for ~CbdataParent and, hence, violates
the parent interface AsyncJob is implementing/overriding.
I have doubts about the above analysis because many other compilers,
including GCC v5 and clang are happy with the default virtual
CbdataParent destructor. If my analysis is correct, then the rule of
thumb is: Base classes must not use "= default" destructors until all
our implicit destructors become "noexcept".
AsyncJob classes can now use C++11 overrides as long as they use the new
CBDATA_CHILD() macro instead of old CBDATA_CLASS().
I have prohibited multiple CBDATA_CHILD() classes on the same
inheritance branch by adding the "final" specifier to toCbdata(). Such
classes feel dangerous because they may have different sizes and it is
not obvious to me whether the cbdata code will call the right size-
specific delete for them. We can easily relax this later if needed.
Alex Rousskov [Fri, 11 Mar 2016 18:00:51 +0000 (11:00 -0700)]
Bug 7: Update cached entries on 304 responses.
New Store API to update entry metadata and headers on 304s.
Support entry updates in shared memory cache and rock cache_dirs.
No changes to ufs-based cache_dirs: Their entries are still not updated.
* Atomic StoreEntry metadata updating
StoreEntry metadata (swap_file_sz, timestamps, etc.) is used
throughout Squid code. Metadata cannot be updated atomically because
it has many fields, but a partial update to those fields causes
assertions. Still, we must update metadata when updating HTTP
headers. Locking the entire entry for a rewrite does not work well
because concurrent requests will attempt to download a new entry
copy, defeating the very HTTP 304 optimization we want to support.
Ipc::StoreMap index now uses an extra level of indirection (the
StoreMap::fileNos index) which allows StoreMap control which
anchor/fileno is associated with a given StoreEntry key. The entry
updating code creates a disassociated (i.e., entry/key-less) anchor,
writes new metadata and headers using that new anchor, and then
_atomically_ switches the map to use that new anchor. This allows old
readers to continue reading using the stale anchor/fileno as if
nothing happened while a new reader gets the new anchor/fileno.
Shared memory usage increase: 8 additional bytes per cache entry: 4
for the extra level of indirection (StoreMapFileNos) plus 4 for
splicing fresh chain prefix with the stale chain suffix
(StoreMapAnchor::splicingPoint). However, if the updated headers are
larger than the stale ones, Squid will allocate shared memory pages
to accommodate for the increase, leading to shared memory
fragmentation/waste for small increases.
* Revamped rock index rebuild process
The index rebuild process had to be completely revamped because
splicing fresh and stale entry slot chain segments implies tolerating
multiple entry versions in a single chain and the old code was based
on the assumption that different slot versions are incompatible. We
were also uncomfortable with the old cavalier approach to accessing
two differently indexed layers of information (entry vs. slot) using
the same set of class fields, making it trivial to accidentally
access entry data while using slot index.
During the rewrite of the index rebuilding code, we also discovered a
way to significantly reduce RAM usage for the index build map (a
temporary object that is allocated in the beginning and freed at the
end of the index build process). The savings depend on the cache
size: A small cache saves about 30% (17 vs 24 bytes per entry/slot)
while a 1TB cache_dir with 32KB slots (which implies uneven
entry/slot indexes) saves more than 50% (~370MB vs. ~800MB).
Adjusted how invalid slots are counted. The code was sometimes
counting invalid entries and sometimes invalid entry slots. We should
always count _slots_ now because progress is measured in the number
of slots scanned, not entries loaded. This accounting change may
surprise users with much higher "Invalid entries" count in cache.log
upon startup, but at least the new reports are meaningful.
This rewrite does not attempt to solve all rock index build problems.
For example, the code still assumes that StoreEntry metadata fits a
single slot which is not always true for very small slots.
Alex Rousskov [Fri, 11 Mar 2016 17:24:13 +0000 (10:24 -0700)]
Removed SWAPOUT_WRITING assertion from storeSwapMetaBuild().
I do not see any strong dependency of that code on that state and we
need to be able to build swap metadata when updating a stale entry
(which would not normally be in the SWAPOUT_WRITING state).
The biggest danger is that somebody calls storeSwapMetaBuild() when the
entry metadata is not yet stable. I am not sure we have a way of
detecting that without using something as overly strong as
SWAPOUT_WRITING.
Squid crashes on shutdown while cleaning up idle ICAP connections.
The global Adaptation::Icap::TheConfig object is automatically
destroyed when Squid exits. Its destructor destroys Icap::ServiceRep
objects that, in turn, close all open connections in the idle
connections pool. Since this happens after comm_exit has destroyed all
Comm structures associated with those connections, Squid crases.
Amos Jeffries [Tue, 1 Mar 2016 02:57:50 +0000 (15:57 +1300)]
RFC 7725: Add registry entry for 451 status text
While Squid does not generate these messages automatically we still have
to relay the status line text accurately, and admin may want to use it
for deny_info status.
After certain failures, FwdState::retryOrBail() may be called twice,
once from FwdState::unregisterdServerEnd() [called from
HttpStateData::swanSong()] and once from the FwdState's own connection
close handler. This may result in two concurrent connections to the
remote server, followed by an assertion upon a connection closure.
This patch:
- After HttpStateData failures, instead of closing the squid-to-peer
connection directly (and, hence, triggering closure handlers), calls
HttpStateData::closeServer() and mustStop() for a cleaner exit with
fewer wasteful side effects and better debugging.
- Creates and remembers a FwdState close handler AsyncCall so that
comm_remove_close_handler() can cancel an already scheduled callback.
The conversion to the AsyncCall was necessary because legacy [close
handler callbacks] cannot be canceled once scheduled.
projects / thirdparty / squid.git / log
