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2017-08-29Teach libpq to detect integer overflow in the row count of a PGresult.Tom Lane
Adding more than 1 billion rows to a PGresult would overflow its ntups and tupArrSize fields, leading to client crashes. It'd be desirable to use wider fields on 64-bit machines, but because all of libpq's external APIs use plain "int" for row counters, that's going to be hard to accomplish without an ABI break. Given the lack of complaints so far, and the general pain that would be involved in using such huge PGresults, let's settle for just preventing the overflow and reporting a useful error message if it does happen. Also, for a couple more lines of code we can increase the threshold of trouble from INT_MAX/2 to INT_MAX rows. To do that, refactor pqAddTuple() to allow returning an error message that replaces the default assumption that it failed because of out-of-memory. Along the way, fix PQsetvalue() so that it reports all failures via pqInternalNotice(). It already did so in the case of bad field number, but neglected to report anything for other error causes. Because of the potential for crashes, this seems like a back-patchable bug fix, despite the lack of field reports. Michael Paquier, per a complaint from Igor Korot. Discussion: https://postgr.es/m/CA+FnnTxyLWyjY1goewmJNxC==HQCCF4fKkoCTa9qR36oRAHDPw@mail.gmail.com
2016-10-10In PQsendQueryStart(), avoid leaking any left-over async result.Tom Lane
Ordinarily there would not be an async result sitting around at this point, but it appears that in corner cases there can be. Considering all the work we're about to launch, it's hardly going to cost anything noticeable to check. It's been like this forever, so back-patch to all supported branches. Report: <CAD-Qf1eLUtBOTPXyFQGW-4eEsop31tVVdZPu4kL9pbQ6tJPO8g@mail.gmail.com>
2016-08-26Add a nonlocalized version of the severity field to client error messages.Tom Lane
This has been requested a few times, but the use-case for it was never entirely clear. The reason for adding it now is that transmission of error reports from parallel workers fails when NLS is active, because pq_parse_errornotice() wrongly assumes that the existing severity field is nonlocalized. There are other ways we could have fixed that, but the other options were basically kluges, whereas this way provides something that's at least arguably a useful feature along with the bug fix. Per report from Jakob Egger. Back-patch into 9.6, because otherwise parallel query is essentially unusable in non-English locales. The problem exists in 9.5 as well, but we don't want to risk changing on-the-wire behavior in 9.5 (even though the possibility of new error fields is specifically called out in the protocol document). It may be sufficient to leave the issue unfixed in 9.5, given the very limited usefulness of pq_parse_errornotice in that version. Discussion: <A88E0006-13CB-49C6-95CC-1A77D717213C@eggerapps.at>
2016-08-05Teach libpq to decode server version correctly from future servers.Tom Lane
Beginning with the next development cycle, PG servers will report two-part not three-part version numbers. Fix libpq so that it will compute the correct numeric representation of such server versions for reporting by PQserverVersion(). It's desirable to get this into the field and back-patched ASAP, so that older clients are more likely to understand the new server version numbering by the time any such servers are in the wild. (The results with an old client would probably not be catastrophic anyway for a released server; for example "10.1" would be interpreted as 100100 which would be wrong in detail but would not likely cause an old client to misbehave badly. But "10devel" or "10beta1" would result in sversion==0 which at best would result in disabling all use of modern features.) Extracted from a patch by Peter Eisentraut; comments added by me Patch: <802ec140-635d-ad86-5fdf-d3af0e260c22@2ndquadrant.com>
2016-04-03Add libpq support for recreating an error message with different verbosity.Tom Lane
Often, upon getting an unexpected error in psql, one's first wish is that the verbosity setting had been higher; for example, to be able to see the schema-name field or the server code location info. Up to now the only way has been to adjust the VERBOSITY variable and repeat the failing query. That's a pain, and it doesn't work if the error isn't reproducible. This commit adds support in libpq for regenerating the error message for an existing error PGresult at any desired verbosity level. This is almost just a matter of refactoring the existing code into a subroutine, but there is one bit of possibly-needed information that was not getting put into PGresults: the text of the last query sent to the server. We must add that string to the contents of an error PGresult. But we only need to save it if it might be used, which with the existing error-formatting code only happens if there is a PG_DIAG_STATEMENT_POSITION error field, which is probably pretty rare for errors in production situations. So really the overhead when the feature isn't used should be negligible. Alex Shulgin, reviewed by Daniel Vérité, some improvements by me
2016-01-02Update copyright for 2016Bruce Momjian
Backpatch certain files through 9.1
2015-11-12Fix unwanted flushing of libpq's input buffer when socket EOF is seen.Tom Lane
In commit 210eb9b743c0645d I centralized libpq's logic for closing down the backend communication socket, and made the new pqDropConnection routine always reset the I/O buffers to empty. Many of the call sites previously had not had such code, and while that amounted to an oversight in some cases, there was one place where it was intentional and necessary *not* to flush the input buffer: pqReadData should never cause that to happen, since we probably still want to process whatever data we read. This is the true cause of the problem Robert was attempting to fix in c3e7c24a1d60dc6a, namely that libpq no longer reported the backend's final ERROR message before reporting "server closed the connection unexpectedly". But that only accidentally fixed it, by invoking parseInput before the input buffer got flushed; and very likely there are timing scenarios where we'd still lose the message before processing it. To fix, pass a flag to pqDropConnection to tell it whether to flush the input buffer or not. On review I think flushing is actually correct for every other call site. Back-patch to 9.3 where the problem was introduced. In HEAD, also improve the comments added by c3e7c24a1d60dc6a.
2015-11-12libpq: Notice errors a backend may have sent just before dying.Robert Haas
At least since the introduction of Hot Standby, the backend has sometimes sent fatal errors even when no client query was in progress, assuming that the client would receive it. However, pqHandleSendFailure was not in sync with this assumption, and only tries to catch notices and notifies. Add a parseInput call to the loop there to fix. Andres Freund suggested the fix. Comments are by me. Reviewed by Michael Paquier.
2015-03-08Fix documentation for libpq's PQfn().Tom Lane
The SGML docs claimed that 1-byte integers could be sent or received with the "isint" options, but no such behavior has ever been implemented in pqGetInt() or pqPutInt(). The in-code documentation header for PQfn() was even less in tune with reality, and the code itself used parameter names matching neither the SGML docs nor its libpq-fe.h declaration. Do a bit of additional wordsmithing on the SGML docs while at it. Since the business about 1-byte integers is a clear documentation bug, back-patch to all supported branches.
2015-02-21Some more FLEXIBLE_ARRAY_MEMBER fixes.Tom Lane
2015-01-24Replace a bunch more uses of strncpy() with safer coding.Tom Lane
strncpy() has a well-deserved reputation for being unsafe, so make an effort to get rid of nearly all occurrences in HEAD. A large fraction of the remaining uses were passing length less than or equal to the known strlen() of the source, in which case no null-padding can occur and the behavior is equivalent to memcpy(), though doubtless slower and certainly harder to reason about. So just use memcpy() in these cases. In other cases, use either StrNCpy() or strlcpy() as appropriate (depending on whether padding to the full length of the destination buffer seems useful). I left a few strncpy() calls alone in the src/timezone/ code, to keep it in sync with upstream (the IANA tzcode distribution). There are also a few such calls in ecpg that could possibly do with more analysis. AFAICT, none of these changes are more than cosmetic, except for the four occurrences in fe-secure-openssl.c, which are in fact buggy: an overlength source leads to a non-null-terminated destination buffer and ensuing misbehavior. These don't seem like security issues, first because no stack clobber is possible and second because if your values of sslcert etc are coming from untrusted sources then you've got problems way worse than this. Still, it's undesirable to have unpredictable behavior for overlength inputs, so back-patch those four changes to all active branches.
2015-01-06Update copyright for 2015Bruce Momjian
Backpatch certain files through 9.0
2014-05-06pgindent run for 9.4Bruce Momjian
This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
2014-04-16libpq: use pgsocket for socket values, for portabilityBruce Momjian
Previously, 'int' was used for socket values in libpq, but socket values are unsigned on Windows. This is a style correction. Initial patch and previous PGINVALID_SOCKET initial patch by Joel Jacobson, modified by me Report from PVS-Studio
2014-03-03Fix whitespacePeter Eisentraut
2014-03-01Various Coverity-spotted fixesStephen Frost
A number of issues were identified by the Coverity scanner and are addressed in this patch. None of these appear to be security issues and many are mostly cosmetic changes. Short comments for each of the changes follows. Correct the semi-colon placement in be-secure.c regarding SSL retries. Remove a useless comparison-to-NULL in proc.c (value is dereferenced prior to this check and therefore can't be NULL). Add checking of chmod() return values to initdb. Fix a couple minor memory leaks in initdb. Fix memory leak in pg_ctl- involves free'ing the config file contents. Use an int to capture fgetc() return instead of an enum in pg_dump. Fix minor memory leaks in pg_dump. (note minor change to convertOperatorReference()'s API) Check fclose()/remove() return codes in psql. Check fstat(), find_my_exec() return codes in psql. Various ECPG memory leak fixes. Check find_my_exec() return in ECPG. Explicitly ignore pqFlush return in libpq error-path. Change PQfnumber() to avoid doing an strdup() when no changes required. Remove a few useless check-against-NULL's (value deref'd beforehand). Check rmtree(), malloc() results in pg_regress. Also check get_alternative_expectfile() return in pg_regress.
2014-02-12Improve libpq's error recovery for connection loss during COPY.Tom Lane
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.
2014-01-07Update copyright for 2014Bruce Momjian
Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
2013-06-03Additional spelling correctionsStephen Frost
A few more minor spelling corrections, no functional changes. Thom Brown
2013-05-29pgindent run for release 9.3Bruce Momjian
This is the first run of the Perl-based pgindent script. Also update pgindent instructions.
2013-01-01Update copyrights for 2013Bruce Momjian
Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
2012-12-13Allow a streaming replication standby to follow a timeline switch.Heikki Linnakangas
Before this patch, streaming replication would refuse to start replicating if the timeline in the primary doesn't exactly match the standby. The situation where it doesn't match is when you have a master, and two standbys, and you promote one of the standbys to become new master. Promoting bumps up the timeline ID, and after that bump, the other standby would refuse to continue. There's significantly more timeline related logic in streaming replication now. First of all, when a standby connects to primary, it will ask the primary for any timeline history files that are missing from the standby. The missing files are sent using a new replication command TIMELINE_HISTORY, and stored in standby's pg_xlog directory. Using the timeline history files, the standby can follow the latest timeline present in the primary (recovery_target_timeline='latest'), just as it can follow new timelines appearing in an archive directory. START_REPLICATION now takes a TIMELINE parameter, to specify exactly which timeline to stream WAL from. This allows the standby to request the primary to send over WAL that precedes the promotion. The replication protocol is changed slightly (in a backwards-compatible way although there's little hope of streaming replication working across major versions anyway), to allow replication to stop when the end of timeline reached, putting the walsender back into accepting a replication command. Many thanks to Amit Kapila for testing and reviewing various versions of this patch.
2012-08-13Add runtime checks for number of query parameters passed to libpq functions.Heikki Linnakangas
The maximum number of parameters supported by the FE/BE protocol is 65535, as it's transmitted as a 16-bit unsigned integer. However, the nParams arguments to libpq functions are all of type 'int'. We can't change the signature of libpq functions, but a simple bounds check is in order to make it more clear what's going wrong if you try to pass more than 65535 parameters. Per complaint from Jim Vanns.
2012-08-02Replace libpq's "row processor" API with a "single row" mode.Tom Lane
After taking awhile to digest the row-processor feature that was added to libpq in commit 92785dac2ee7026948962cd61c4cd84a2d052772, we've concluded it is over-complicated and too hard to use. Leave the core infrastructure changes in place (that is, there's still a row processor function inside libpq), but remove the exposed API pieces, and instead provide a "single row" mode switch that causes PQgetResult to return one row at a time in separate PGresult objects. This approach incurs more overhead than proper use of a row processor callback would, since construction of a PGresult per row adds extra cycles. However, it is far easier to use and harder to break. The single-row mode still affords applications the primary benefit that the row processor API was meant to provide, namely not having to accumulate large result sets in memory before processing them. Preliminary testing suggests that we can probably buy back most of the extra cycles by micro-optimizing construction of the extra results, but that task will be left for another day. Marko Kreen
2012-06-10Run pgindent on 9.2 source tree in preparation for first 9.3Bruce Momjian
commit-fest.
2012-04-23Lots of doc corrections.Robert Haas
Josh Kupershmidt
2012-04-04Add a "row processor" API to libpq for better handling of large results.Tom Lane
Traditionally libpq has collected an entire query result before passing it back to the application. That provides a simple and transactional API, but it's pretty inefficient for large result sets. This patch allows the application to process each row on-the-fly instead of accumulating the rows into the PGresult. Error recovery becomes a bit more complex, but often that tradeoff is well worth making. Kyotaro Horiguchi, reviewed by Marko Kreen and Tom Lane
2012-01-01Update copyright notices for year 2012.Bruce Momjian
2011-08-05Tweak PQresStatus() to avoid a clang compiler warning.Robert Haas
The previous test for status < 0 test is in fact testing nothing if the compiler considers an enum to be an unsigned data type. clang doesn't like tautologies, so do this instead. Report by Peter Geoghegan, fix as suggested by Tom Lane.
2011-07-21Fix PQsetvalue() to avoid possible crash when adding a new tuple.Tom Lane
PQsetvalue unnecessarily duplicated the logic in pqAddTuple, and didn't duplicate it exactly either --- pqAddTuple does not care what is in the tuple-pointer array positions beyond the last valid entry, whereas the code in PQsetvalue assumed such positions would contain NULL. This led to possible crashes if PQsetvalue was applied to a PGresult that had previously been enlarged with pqAddTuple, for instance one built from a server query. Fix by relying on pqAddTuple instead of duplicating logic, and not assuming anything about the contents of res->tuples[res->ntups]. Back-patch to 8.4, where PQsetvalue was introduced. Andrew Chernow
2011-04-10pgindent run before PG 9.1 beta 1.Bruce Momjian
2011-03-30Adjust error message, now that we expect other message types than connectionHeikki Linnakangas
close at this point. Fix PQsetnonblocking() comment. Fujii Masao
2011-01-01Stamp copyrights for year 2011.Bruce Momjian
2010-12-28Fix ill-advised placement of PGRES_COPY_BOTH enum value.Tom Lane
It must be added at the end of the ExecStatusType enum to avoid ABI breakage compared to previous libpq versions. Noted by Magnus.
2010-12-11Allow bidirectional copy messages in streaming replication mode.Robert Haas
Fujii Masao. Review by Alvaro Herrera, Tom Lane, and myself.
2010-09-20Remove cvs keywords from all files.Magnus Hagander
2010-02-26pgindent run for 9.0Bruce Momjian
2010-02-17Stamp HEAD as 9.0devel, and update various places that were referring to 8.5Tom Lane
(hope I got 'em all). Per discussion, this release will be 9.0 not 8.5.
2010-02-16Have SELECT and CREATE TABLE AS queries return a row count. While thisBruce Momjian
is invisible in psql, other interfaces, like libpq, make this value visible. Boszormenyi Zoltan
2010-01-21Fix unsafe loop test, and declare as_ident as bool rather than int.Robert Haas
2010-01-21Add new escaping functions PQescapeLiteral and PQescapeIdentifier.Robert Haas
PQescapeLiteral is similar to PQescapeStringConn, but it relieves the caller of the need to know how large the output buffer should be, and it provides the appropriate quoting (in addition to escaping special characers within the string). PQescapeIdentifier provides similar functionality for escaping identifiers. Per recent discussion with Tom Lane.
2010-01-02Update copyright for the year 2010.Bruce Momjian
2009-08-04Teach PQescapeByteaConn() to use hex format when the target connection isTom Lane
to a server >= 8.5. Per my proposal in discussion of hex-format patch.
2009-08-04Support hex-string input and output for type BYTEA.Tom Lane
Both hex format and the traditional "escape" format are automatically handled on input. The output format is selected by the new GUC variable bytea_output. As committed, bytea_output defaults to HEX, which is an *incompatible change*. We will keep it this way for awhile for testing purposes, but should consider whether to switch to the more backwards-compatible default of ESCAPE before 8.5 is released. Peter Eisentraut
2009-06-118.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef listBruce Momjian
provided by Andrew.
2009-05-27Reverting patch just in case a compiler treats this enum as signed.Michael Meskes
2009-05-21Removed comparison of unsigned expression < 0.Michael Meskes
2009-01-01Update copyright for 2009.Bruce Momjian
2008-09-19Improve the recently-added libpq events code to provide more consistentTom Lane
guarantees about whether event procedures will receive DESTROY events. They no longer need to defend themselves against getting a DESTROY without a successful prior CREATE. Andrew Chernow
2008-09-17Add an "events" system to libpq, whereby applications can get callbacks thatTom Lane
enable them to manage private data associated with PGconns and PGresults. Andrew Chernow and Merlin Moncure