In pqSendSome, if the connection is already closed at entry, discard any
queued output data before returning. There is no possibility of ever
sending the data, and anyway this corresponds to what we'd do if we'd
detected a hard error while trying to send(). This avoids possible
indefinite bloat of the output buffer if the application keeps trying
to send data (or even just keeps trying to do PQputCopyEnd, as psql
indeed will).
Because PQputCopyEnd won't transition out of PGASYNC_COPY_IN state
until it's successfully queued the COPY END message, and pqPutMsgEnd
doesn't distinguish a queuing failure from a pqSendSome failure,
this omission allowed an infinite loop in psql if the connection closure
occurred when we had at least 8K queued to send. It might be worth
refactoring so that we can make that distinction, but for the moment
the other changes made here seem to offer adequate defenses.
To guard against other variants of this scenario, do not allow
PQgetResult to return a PGRES_COPY_XXX result if the connection is
already known dead. Make sure it returns PGRES_FATAL_ERROR instead.
Per report from Stephen Frost. Back-patch to all active branches.
This has long been done by the MSVC build system, and has caused
confusion in the past when programs like psql have failed to start
because they can't find the DLL. If it's in the same directory as it now
will be they will find it.
Backpatch to all live branches.
In the platform that doesn't support Unix-domain socket, when
neither host nor hostaddr are specified, the default host
'localhost' is used to connect to the server and PQhost() must
return that, but it didn't. This patch fixes PQhost() so that
it returns the default host in that case.
Also this patch fixes PQhost() so that it doesn't return
Unix-domain socket directory path in the platform that doesn't
support Unix-domain socket.
Back-patch to all supported versions.
While working on most platforms the old way sometimes created alignment
problems. This should fix it. Also the regresion tests were updated to test for
the reported case.
Report and fix by MauMau <maumau307@gmail.com>
Conflicts:
src/interfaces/ecpg/preproc/type.c
src/interfaces/ecpg/test/expected/sql-desc.c
variables is varchar. This fixes this test case:
int main(void)
{
exec sql begin declare section;
varchar a[50], b[50];
exec sql end declare section;
return 0;
}
Since varchars are internally turned into custom structs and
the type name is emitted for these variable declarations,
the preprocessed code previously had:
struct varchar_1 { ... } a _,_ struct varchar_2 { ... } b ;
The comma in the generated C file was a syntax error.
There are no regression test changes since it's not exercised.
Patch by Boszormenyi Zoltan <zb@cybertec.at>
Conflicts:
src/interfaces/ecpg/preproc/ecpg.trailer
In libpq, we set up and pass to OpenSSL callback routines to handle
locking. When we run out of SSL connections, we try to clean things
up by de-registering the hooks. Unfortunately, we had a few calls
into the OpenSSL library after these hooks were de-registered during
SSL cleanup which lead to deadlocking. This moves the thread callback
cleanup to be after all SSL-cleanup related OpenSSL library calls.
I've been unable to reproduce the deadlock with this fix.
In passing, also move the close_SSL call to be after unlocking our
ssl_config mutex when in a failure state. While it looks pretty
unlikely to be an issue, it could have resulted in deadlocks if we
ended up in this code path due to something other than SSL_new
failing. Thanks to Heikki for pointing this out.
Back-patch to all supported versions; note that the close_SSL issue
only goes back to 9.0, so that hunk isn't included in the 8.4 patch.
Initially found and reported by Vesa-Matti J Kari; many thanks to
both Heikki and Andres for their help running down the specific
issue and reviewing the patch.
On Unix-ish platforms, EWOULDBLOCK may be the same as EAGAIN, which is
*not* a success return, at least not on Linux. We need to treat it as a
failure to avoid giving a misleading error message. Per the Single Unix
Spec, only EINPROGRESS and EINTR returns indicate that the connection
attempt is in progress.
On Windows, on the other hand, EWOULDBLOCK (WSAEWOULDBLOCK) is the expected
case. We must accept EINPROGRESS as well because Cygwin will return that,
and it doesn't seem worth distinguishing Cygwin from native Windows here.
It's not very clear whether EINTR can occur on Windows, but let's leave
that part of the logic alone in the absence of concrete trouble reports.
Also, remove the test for errno == 0, effectively reverting commit
da9501bddb, which AFAICS was just a thinko;
or at best it might have been a workaround for a platform-specific bug,
which we can hope is gone now thirteen years later. In any case, since
libpq makes no effort to reset errno to zero before calling connect(),
it seems unlikely that that test has ever reliably done anything useful.
Andres Freund and Tom Lane
I fixed this code back in commit 841b4a2d5, but didn't think carefully
enough about the behavior near zero, which meant it improperly rejected
1999-12-31 24:00:00. Per report from Magnus Hagander.
This bug goes back to the original Postgres95 sources. Its significance
to modern PG versions is marginal, since we have not used PQprintTuples()
internally in a very long time, and it doesn't seem to have ever been
documented either. Still, it *is* exposed to client apps, so somebody
out there might possibly be using it.
Xi Wang
The length of a socket path name is constrained by the size of struct
sockaddr_un, and there's not a lot we can do about it since that is a
kernel API. However, it would be a good thing if we produced an
intelligible error message when the user specifies a socket path that's too
long --- and getaddrinfo's standard API is too impoverished to do this in
the natural way. So insert explicit tests at the places where we construct
a socket path name. Now you'll get an error that makes sense and even
tells you what the limit is, rather than something generic like
"Non-recoverable failure in name resolution".
Per trouble report from Jeremy Drake and a fix idea from Andrew Dunstan.
I found that these functions tend to return -1 while leaving an empty error
message string in the PGconn, if they suffer some kind of I/O error on the
file. The reason is that lo_close, which thinks it's executed a perfectly
fine SQL command, clears the errorMessage. The minimum-change workaround
is to reorder operations here so that we don't fill the errorMessage until
after lo_close.
Both libpq and the backend would truncate a common name extracted from a
certificate at 32 bytes. Replace that fixed-size buffer with dynamically
allocated string so that there is no hard limit. While at it, remove the
code for extracting peer_dn, which we weren't using for anything; and
don't bother to store peer_cn longer than we need it in libpq.
This limit was not so terribly unreasonable when the code was written,
because we weren't using the result for anything critical, just logging it.
But now that there are options for checking the common name against the
server host name (in libpq) or using it as the user's name (in the server),
this could result in undesirable failures. In the worst case it even seems
possible to spoof a server name or user name, if the correct name is
exactly 32 bytes and the attacker can persuade a trusted CA to issue a
certificate in which that string is a prefix of the certificate's common
name. (To exploit this for a server name, he'd also have to send the
connection astray via phony DNS data or some such.) The case that this is
a realistic security threat is a bit thin, but nonetheless we'll treat it
as one.
Back-patch to 8.4. Older releases contain the faulty code, but it's not
a security problem because the common name wasn't used for anything
interesting.
Reported and patched by Heikki Linnakangas
Security: CVE-2012-0867
Ever since we introduced real prepared statements this should work for
different connections. The old solution just emulating prepared statements,
though, wasn't able to handle this.
Closes: #6309
These days, such a response is far more likely to signify a server-side
problem, such as fork failure. Reporting "server does not support SSL"
(in sslmode=require) could be quite misleading. But the results could
be even worse in sslmode=prefer: if the problem was transient and the
next connection attempt succeeds, we'll have silently fallen back to
protocol version 2.0, possibly disabling features the user needs.
Hence, it seems best to just eliminate the assumption that backing off
to non-SSL/2.0 protocol is the way to recover from an "E" response, and
instead treat the server error the same as we would in non-SSL cases.
I tested this change against a pre-7.0 server, and found that there
was a second logic bug in the "prefer" path: the test to decide whether
to make a fallback connection attempt assumed that we must have opened
conn->ssl, which in fact does not happen given an "E" response. After
fixing that, the code does indeed connect successfully to pre-7.0,
as long as you didn't set sslmode=require. (If you did, you get
"Unsupported frontend protocol", which isn't completely off base
given the server certainly doesn't support SSL.)
Since there seems no reason to believe that pre-7.0 servers exist anymore
in the wild, back-patch to all supported branches.
There are assorted situations wherein PQconnectPoll() will abandon a
connection attempt and try again with different parameters (eg, SSL versus
not SSL). However, the code forgot to discard any pending data in libpq's
I/O buffers when doing this. In at least one case (server returns E
message during SSL negotiation), there is unread input data which bollixes
the next connection attempt. I have not checked to see whether this is
possible in the other cases where we close the socket and retry, but it
seems like a matter of good defensive programming to add explicit
buffer-flushing code to all of them.
This is one of several issues exposed by Daniel Farina's report of
misbehavior after a server-side fork failure.
This has been wrong since forever, so back-patch to all supported branches.
On balance, the need to cover this case changes my mind in favor of pushing
all error-message generation duties into the two fe-secure.c routines.
So do it that way.
