If a server returns ERRCODE_CANNOT_CONNECT_NOW, try the next host,
if multiple host names have been provided. This allows dealing
gracefully with standby servers that might not be in hot standby mode
yet.
In the wake of the preceding commit, it might be plausible to retry
many more error cases than we do now, but I (tgl) am hesitant to
move too aggressively on that --- it's not clear it'd be desirable
for cases such as bad-password, for example. But this case seems
safe enough.
Hubert Zhang, reviewed by Takayuki Tsunakawa
Discussion: https://postgr.es/m/BN6PR05MB3492948E4FD76C156E747E8BC9160@BN6PR05MB3492.namprd05.prod.outlook.com
Prefix "could not connect to host-or-socket-path:" to all connection
failure cases that occur after the socket() call, and remove the
ad-hoc server identity data that was appended to a few of these
messages. This should produce much more intelligible error reports
in multiple-target-host situations, especially for error cases that
are off the beaten track to any degree (because none of those provided
any server identity info).
As an example of the change, formerly a connection attempt with a bad
port number such as "psql -p 12345 -h localhost,/tmp" might produce
psql: error: could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 12345?
could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 12345?
could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.12345"?
Now it looks like
psql: error: could not connect to host "localhost" (::1), port 12345: Connection refused
Is the server running on that host and accepting TCP/IP connections?
could not connect to host "localhost" (127.0.0.1), port 12345: Connection refused
Is the server running on that host and accepting TCP/IP connections?
could not connect to socket "/tmp/.s.PGSQL.12345": No such file or directory
Is the server running locally and accepting connections on that socket?
This requires adjusting a couple of regression tests to allow for
variation in the contents of a connection failure message.
Discussion: https://postgr.es/m/BN6PR05MB3492948E4FD76C156E747E8BC9160@BN6PR05MB3492.namprd05.prod.outlook.com
Add an optional callback to regression_main() that, if provided,
is invoked on each test output file before we try to compare it
to the expected-result file.
The main and isolation test programs don't need this (yet).
In pg_regress_ecpg, add a filter that eliminates target-host
details from "could not connect" error reports. This filter
doesn't do anything as of this commit, but it will be needed
by the next one.
In the long run we might want to provide some more general,
perhaps pattern-based, filtering mechanism for test output.
For now, this will solve the immediate problem.
Discussion: https://postgr.es/m/BN6PR05MB3492948E4FD76C156E747E8BC9160@BN6PR05MB3492.namprd05.prod.outlook.com
Previously, we had an undisciplined mish-mash of printfPQExpBuffer and
appendPQExpBuffer calls to report errors within libpq. This commit
establishes a uniform rule that appendPQExpBuffer[Str] should be used.
conn->errorMessage is reset only at the start of an application request,
and then accumulates messages till we're done. We can remove no less
than three different ad-hoc mechanisms that were used to get the effect
of concatenation of error messages within a sequence of operations.
Although this makes things quite a bit cleaner conceptually, the main
reason to do it is to make the world safer for the multiple-target-host
feature that was added awhile back. Previously, there were many cases
in which an error occurring during an individual host connection attempt
would wipe out the record of what had happened during previous attempts.
(The reporting is still inadequate, in that it can be hard to tell which
host got the failure, but that seems like a matter for a separate commit.)
Currently, lo_import and lo_export contain exceptions to the "never
use printfPQExpBuffer" rule. If we changed them, we'd risk reporting
an incidental lo_close failure before the actual read or write
failure, which would be confusing, not least because lo_close happened
after the main failure. We could improve this by inventing an
internal version of lo_close that doesn't reset the errorMessage; but
we'd also need a version of PQfn() that does that, and it didn't quite
seem worth the trouble for now.
Discussion: https://postgr.es/m/BN6PR05MB3492948E4FD76C156E747E8BC9160@BN6PR05MB3492.namprd05.prod.outlook.com
Invent new RawParseModes that allow the core grammar to handle
pl/pgsql expressions and assignments directly, and thereby get rid
of a lot of hackery in pl/pgsql's parser. This moves a good deal
of knowledge about pl/pgsql into the core code: notably, we have to
invent a CoercionContext that matches pl/pgsql's (rather dubious)
historical behavior for assignment coercions. That's getting away
from the original idea of pl/pgsql as an arm's-length extension of
the core, but really we crossed that bridge a long time ago.
The main advantage of doing this is that we can now use the core
parser to generate FieldStore and/or SubscriptingRef nodes to handle
assignments to pl/pgsql variables that are records or arrays. That
fixes a number of cases that had never been implemented in pl/pgsql
assignment, such as nested records and array slicing, and it allows
pl/pgsql assignment to support the datatype-specific subscripting
behaviors introduced in commit c7aba7c14.
There are cosmetic benefits too: when a syntax error occurs in a
pl/pgsql expression, the error report no longer includes the confusing
"SELECT" keyword that used to get prefixed to the expression text.
Also, there seem to be some small speed gains.
Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
This patch essentially allows gram.y to implement a family of related
syntax trees, rather than necessarily always parsing a list of SQL
statements. raw_parser() gains a new argument, enum RawParseMode,
to say what to do. As proof of concept, add a mode that just parses
a TypeName without any other decoration, and use that to greatly
simplify typeStringToTypeName().
In addition, invent a new SPI entry point SPI_prepare_extended() to
allow SPI users (particularly plpgsql) to get at this new functionality.
In hopes of making this the last variant of SPI_prepare(), set up its
additional arguments as a struct rather than direct arguments, and
promise that future additions to the struct can default to zero.
SPI_prepare_cursor() and SPI_prepare_params() can perhaps go away at
some point.
Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
Since at least 2001 we've used putenv() and avoided setenv(), on the
grounds that the latter was unportable and not in POSIX. However,
POSIX added it that same year, and by now the situation has reversed:
setenv() is probably more portable than putenv(), since POSIX now
treats the latter as not being a core function. And setenv() has
cleaner semantics too. So, let's reverse that old policy.
This commit adds a simple src/port/ implementation of setenv() for
any stragglers (we have one in the buildfarm, but I'd not be surprised
if that code is never used in the field). More importantly, extend
win32env.c to also support setenv(). Then, replace usages of putenv()
with setenv(), and get rid of some ad-hoc implementations of setenv()
wannabees.
Also, adjust our src/port/ implementation of unsetenv() to follow the
POSIX spec that it returns an error indicator, rather than returning
void as per the ancient BSD convention. I don't feel a need to make
all the call sites check for errors, but the portability stub ought
to match real-world practice.
Discussion: https://postgr.es/m/2065122.1609212051@sss.pgh.pa.us
The critical issue fixed here is that if a GSSAPI-encrypted connection
is successfully made, pqsecure_open_gss() cleared conn->allow_ssl_try,
as an admittedly-hacky way of preventing us from then trying to tunnel
SSL encryption over the already-encrypted connection. The problem
with that is that if we abandon the GSSAPI connection because of a
failure during authentication, we would not attempt SSL encryption
in the next try with the same server. This can lead to unexpected
connection failure, or silently getting a non-encrypted connection
where an encrypted one is expected.
Fortunately, we'd only manage to make a GSSAPI-encrypted connection
if both client and server hold valid tickets in the same Kerberos
infrastructure, which is a relatively uncommon environment.
Nonetheless this is a very nasty bug with potential security
consequences. To fix, don't reset the flag, instead adding a
check for conn->gssenc being already true when deciding whether
to try to initiate SSL.
While here, fix some lesser issues in libpq's GSSAPI code:
* Use the need_new_connection stanza when dropping an attempted
GSSAPI connection, instead of partially duplicating that code.
The consequences of this are pretty minor: AFAICS it could only
lead to auth_req_received or password_needed remaining set when
they shouldn't, which is not too harmful.
* Fix pg_GSS_error() to not repeat the "mprefix" it's given multiple
times, and to notice any failure return from gss_display_status().
* Avoid gratuitous dependency on NI_MAXHOST in
pg_GSS_load_servicename().
Per report from Mikael Gustavsson. Back-patch to v12 where
this code was introduced.
Discussion: https://postgr.es/m/e5b0b6ed05764324a2f3fe7acfc766d5@smhi.se
ecpglib on certain platforms can't handle the pg_log_fatal calls from
libraries. This was reported by the buildfarm. It needs a refactoring
and return value change if it is later removed.
Backpatch-through: master
Two new routines to allocate a hash context and to free it are created,
as these become necessary for the goal behind this refactoring: switch
the all cryptohash implementations for OpenSSL to use EVP (for FIPS and
also because upstream does not recommend the use of low-level cryptohash
functions for 20 years). Note that OpenSSL hides the internals of
cryptohash contexts since 1.1.0, so it is necessary to leave the
allocation to OpenSSL itself, explaining the need for those two new
routines. This part is going to require more work to properly track
hash contexts with resource owners, but this not introduced here.
Still, this refactoring makes the move possible.
This reduces the number of routines for all SHA2 implementations from
twelve (SHA{224,256,386,512} with init, update and final calls) to five
(create, free, init, update and final calls) by incorporating the hash
type directly into the hash context data.
The new cryptohash routines are moved to a new file, called cryptohash.c
for the fallback implementations, with SHA2 specifics becoming a part
internal to src/common/. OpenSSL specifics are part of
cryptohash_openssl.c. This infrastructure is usable for more hash
types, like MD5 or HMAC.
Any code paths using the internal SHA2 routines are adapted to report
correctly errors, which are most of the changes of this commit. The
zones mostly impacted are checksum manifests, libpq and SCRAM.
Note that e21cbb4 was a first attempt to switch SHA2 to EVP, but it
lacked the refactoring needed for libpq, as done here.
This patch has been tested on Linux and Windows, with and without
OpenSSL, and down to 1.0.1, the oldest version supported on HEAD.
Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/20200924025314.GE7405@paquier.xyz
This is a variant of the normal Unix-domain sockets that don't use the
file system but a separate "abstract" namespace. At the user
interface, such sockets are represented by names starting with "@".
Supported on Linux and Windows right now.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/6dee8574-b0ad-fc49-9c8c-2edc796f0033@2ndquadrant.com
The buildfarm thinks this leads to memory stomps, though annoyingly
I can't duplicate that here. The existing code in strings.pgc is
doing something that doesn't seem to be sanctioned at all really
by the documentation, but I'm disinclined to try to make that nicer
right now. Let's just declare some more output variables in hopes
of working around it.
These were broken in multiple ways:
* The xbstart and xhstart lexer actions neglected to set
"state_before_str_start" before transitioning to the xb/xh states,
thus possibly resulting in "internal error: unreachable state" later.
* The test for valid string contents at the end of xb state was flat out
wrong, as it accounted incorrectly for the "b" prefix that the xbstart
action had injected. Meanwhile, the xh state had no such check at all.
* The generated literal value failed to include any quote marks.
* The grammar did the wrong thing anyway, typically ignoring the
literal value and emitting something else, since BCONST and XCONST
tokens were handled randomly differently from SCONST tokens.
The first of these problems is evidently an oversight in commit
7f380c59f, but the others seem to be very ancient. The lack of
complaints shows that ECPG users aren't using these syntaxes much
(although I do vaguely remember one previous complaint).
As written, this patch is dependent on 7f380c59f, so it can't go
back further than v13. Given the shortage of complaints, I'm not
excited about adapting the patch to prior branches.
Report and patch by Shenhao Wang (test case adjusted by me)
Discussion: https://postgr.es/m/d6402f1bacb74ecba22ef715dbba17fd@G08CNEXMBPEKD06.g08.fujitsu.local
On the same reasoning as in commit 36b931214, forbid using custom
oid_symbol macros in pg_type as well as pg_proc, so that we always
rely on the predictable macro names generated by genbki.pl.
We do continue to grant grandfather status to the names CASHOID and
LSNOID, although those are now considered deprecated aliases for the
preferred names MONEYOID and PG_LSNOID. This is because there's
likely to be client-side code using the old names, and this bout of
neatnik-ism doesn't quite seem worth breaking client code.
There might be a case for grandfathering EVTTRIGGEROID, too, since
externally-maintained PLs may reference that symbol. But renaming
such references to EVENT_TRIGGEROID doesn't seem like a particularly
heavy lift --- we make far more significant backend API changes in
every major release. For now I didn't add that, but we could
reconsider if there's pushback.
The other names changed here seem pretty unlikely to have any outside
uses. Again, we could add alias macros if there are complaints, but
for now I didn't.
As before, no need for a catversion bump.
John Naylor
Discussion: https://postgr.es/m/CAFBsxsHpCbjfoddNGpnnnY5pHwckWfiYkMYSF74PmP1su0+ZOw@mail.gmail.com
We must not set the "done" flag until after we've executed the
initialization function. Otherwise, other threads can fall through
the initial unlocked test before initialization is really complete.
This has been seen to cause rare failures of ecpg's thread/descriptor
test, and it could presumably cause other sorts of misbehavior in
threaded ECPG-using applications, since ecpglib relies on
pthread_once() in several places.
Diagnosis and patch by me, based on investigation by Alexander Lakhin.
Back-patch to all supported branches (the bug dates to 2007).
Discussion: https://postgr.es/m/16685-d6cd241872c101d3@postgresql.org
ECPG's PREPARE ... FROM and EXECUTE IMMEDIATE can optionally take
the target query as a simple literal, rather than the more usual
string-variable reference. This was previously documented as
being a C string literal, but that's a lie in one critical respect:
you can't write a data double quote as \" in such literals. That's
because the lexer is in SQL mode at this point, so it'll parse
double-quoted strings as SQL identifiers, within which backslash
is not special, so \" ends the literal.
I looked into making this work as documented, but getting the lexer
to switch behaviors at just the right point is somewhere between
very difficult and impossible. It's not really worth the trouble,
because these cases are next to useless: if you have a fixed SQL
statement to execute or prepare, you might as well write it as
a direct EXEC SQL, saving the messiness of converting it into
a string literal and gaining the opportunity for compile-time
SQL syntax checking.
Instead, let's just document (and test) the workaround of writing
a double quote as an octal escape (\042) in such cases.
There's no code behavioral change here, so in principle this could
be back-patched, but it's such a niche case I doubt it's worth
the trouble.
Per report from 1250kv.
Discussion: https://postgr.es/m/673825.1603223178@sss.pgh.pa.us
If you write the literal 'abc''def' in an EXEC SQL command, that will
come out the other end as 'abc'def', triggering a syntax error in the
backend. Likewise, "abc""def" is reduced to "abc"def" which is wrong
syntax for a quoted identifier.
The cause is that the lexer thinks it should emit just one quote
mark, whereas what it really should do is keep the string as-is.
Add some docs and test cases, too.
Although this seems clearly a bug, I fear users wouldn't appreciate
changing it in minor releases. Some may well be working around it
by applying an extra doubling of affected quotes, as for example
sql/dyntest.pgc has been doing.
Per investigation of a report from 1250kv, although this isn't
exactly what he/she was on about.
Discussion: https://postgr.es/m/673825.1603223178@sss.pgh.pa.us
After de8feb1f3a23465b5737e8a8c160e8ca62f61339, some warnings remained
that were only visible when using GCC on Windows. Fix those as well.
Note that the ecpg test source files don't use the full pg_config.h,
so we can't use pg_funcptr_t there but have to do it the long way.
According to Microsoft's documentation, 2.2 has been the current
version since Windows 98 or so. Moreover, that's what the Postgres
backend has been requesting since 2004 (cf commit 4cdf51e64).
So there seems no reason for libpq to keep asking for 1.1.
Bring thread_test along, too, so that we're uniformly asking for 2.2
in all our WSAStartup calls.
It's not clear whether there's any point in back-patching this,
so for now I didn't.
Discussion: https://postgr.es/m/132799.1602960277@sss.pgh.pa.us
The Windows documentation insists that every WSAStartup call should
have a matching WSACleanup call. However, if that ever had actual
relevance, it wasn't in this century. Every remotely-modern Windows
kernel is capable of cleaning up when a process exits without doing
that, and must be so to avoid resource leaks in case of a process
crash. Moreover, Postgres backends have done WSAStartup without
WSACleanup since commit 4cdf51e64 in 2004, and we've never seen any
indication of a problem with that.
libpq's habit of doing WSAStartup during connection start and
WSACleanup during shutdown is also rather inefficient, since a
series of non-overlapping connection requests leads to repeated,
quite expensive DLL unload/reload cycles. We document a workaround
for that (having the application call WSAStartup for itself), but
that's just a kluge. It's also worth noting that it's far from
uncommon for applications to exit without doing PQfinish, and
we've not heard reports of trouble from that either.
However, the real reason for acting on this is that recent
experiments by Alexander Lakhin suggest that calling WSACleanup
during PQfinish might be triggering the symptom we occasionally see
that a process using libpq fails to emit expected stdio output.
Therefore, let's change libpq so that it calls WSAStartup only
once per process, during the first connection attempt, and never
calls WSACleanup at all.
While at it, get rid of the only other WSACleanup call in our code
tree, in pg_dump/parallel.c; that presumably is equally useless.
If this proves to suppress the fairly-common ecpg test failures
we see on Windows, I'll back-patch, but for now let's just do it
in HEAD and see what happens.
Discussion: https://postgr.es/m/ac976d8c-03df-d6b8-025c-15a2de8d9af1@postgrespro.ru
The in-core equivalents can make use of built-in functions if the
compiler supports this option, making optimizations possible. 0ba99c8
replaced all existing calls in the code base at this time, but b0b39f7
(GSSAPI encryption) has forgotten to do the switch.
Discussion: https://postgr.es/m/20201014055303.GG3349@paquier.xyz
Up to now, only ECONNRESET (and EPIPE, in most but not quite all places)
received special treatment in our error handling logic. This patch
changes things so that related error codes such as ECONNABORTED are
also recognized as indicating that the connection's dead and unlikely
to come back.
We continue to think, however, that only ECONNRESET and EPIPE should be
reported as probable server crashes; the other cases indicate network
connectivity problems but prove little about the server's state. Thus,
there's no change in the error message texts that are output for such
cases. The key practical effect is that errcode_for_socket_access()
will report ERRCODE_CONNECTION_FAILURE rather than
ERRCODE_INTERNAL_ERROR for a network failure. It's expected that this
will fix buildfarm member lorikeet's failures since commit 32a9c0bdf,
as that seems to be due to not treating ECONNABORTED equivalently to
ECONNRESET.
The set of errnos treated this way now includes ECONNABORTED, EHOSTDOWN,
EHOSTUNREACH, ENETDOWN, ENETRESET, and ENETUNREACH. Several of these
were second-class citizens in terms of their handling in places like
get_errno_symbol(), so upgrade the infrastructure where necessary.
As committed, this patch assumes that all these symbols are defined
everywhere. POSIX specifies all of them except EHOSTDOWN, but that
seems to exist on all platforms of interest; we'll see what the
buildfarm says about that.
Probably this should be back-patched, but let's see what the buildfarm
thinks of it first.
Fujii Masao and Tom Lane
Discussion: https://postgr.es/m/2621622.1602184554@sss.pgh.pa.us
Use a StringInfo instead of a fixed-size buffer in parseServiceInfo().
While we've not heard complaints about the existing 255-byte limit,
it certainly seems possible that complex cases could run afoul of it.
Daniel Gustafsson
Discussion: https://postgr.es/m/48A4FA71-524E-41B9-953A-FD04EF36E2E7@yesql.se
Further experience says that the appending behavior offered by
pg_get_line_append is useful to only a very small minority of callers.
For most, the requirement to reset the buffer after each line is just
an error-prone nuisance. Hence, invent another alternative call
pg_get_line_buf, which takes care of that detail.
Noted while reviewing a patch from Daniel Gustafsson.
Discussion: https://postgr.es/m/48A4FA71-524E-41B9-953A-FD04EF36E2E7@yesql.se
Up to now, if you tried to omit "AS" before a column label in a SELECT
list, it would only work if the column label was an IDENT, that is not
any known keyword. This is rather unfriendly considering that we have
so many keywords and are constantly growing more. In the wake of commit
1ed6b8956 it's possible to improve matters quite a bit.
We'd originally tried to make this work by having some of the existing
keyword categories be allowed without AS, but that didn't work too well,
because each category contains a few special cases that don't work
without AS. Instead, invent an entirely orthogonal keyword property
"can be bare column label", and mark all keywords that way for which
we don't get shift/reduce errors by doing so.
It turns out that of our 450 current keywords, all but 39 can be made
bare column labels, improving the situation by over 90%. This number
might move around a little depending on future grammar work, but it's
a pretty nice improvement.
Mark Dilger, based on work by myself and Robert Haas;
review by John Naylor
Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
Refactor replace_string() to use a StringInfo for the modifiable
string argument. This allows the string to be of indefinite size
initially and/or grow substantially during replacement. The previous
logic in convert_sourcefiles_in() had a hard-wired limit of 1024
bytes on any line in input/*.sql or output/*.out files. While we've
not had reports of trouble yet, it'd surely have bit us someday.
This also fixes replace_string() so it won't get into an infinite
loop if the string-to-be-replaced is a substring of the replacement.
That's unlikely to happen in current usage, but the function surely
shouldn't depend on it.
Also fix ecpg_filter() to use a StringInfo and thereby remove its
hard limit of 300 bytes on the length of an ecpg source line.
Asim Rama Praveen and Georgios Kokolatos,
reviewed by Alvaro Herrera and myself
Discussion: https://postgr.es/m/y9Dlk2QhiZ39DhaB1QE9mgZ95HcOQKZCNtGwN7XCRKMdBRBnX_0woaRUtTjloEp4PKA6ERmcUcfq3lPGfKPOJ5xX2TV-5WoRYyySeNHRzdw=@protonmail.com
Historically there's been a hard-wired assumption here that no line of
a .pgpass file could be as long as NAMEDATALEN*5 bytes. That's a bit
shaky to start off with, because (a) there's no reason to suppose that
host names fit in NAMEDATALEN, and (b) this figure fails to allow for
backslash escape characters. However, it fails completely if someone
wants to use a very long password, and we're now hearing reports of
people wanting to use "security tokens" that can run up to several
hundred bytes. Another angle is that the file is specified to allow
comment lines, but there's no reason to assume that long comment lines
aren't possible.
Rather than guessing at what might be a more suitable limit, let's
replace the fixed-size buffer with an expansible PQExpBuffer. That
adds one malloc/free cycle to the typical use-case, but that's surely
pretty cheap relative to the I/O this code has to do.
Also, add TAP test cases to exercise this code, because there was no
test coverage before.
This reverts most of commit 2eb3bc588, as there's no longer a need for
a warning message about overlength .pgpass lines. (I kept the explicit
check for comment lines, though.)
In HEAD and v13, this also fixes an oversight in 74a308cf5: there's not
much point in explicit_bzero'ing the line buffer if we only do so in two
of the three exit paths.
Back-patch to all supported branches, except that the test case only
goes back to v10 where src/test/authentication/ was added.
Discussion: https://postgr.es/m/4187382.1598909041@sss.pgh.pa.us
They are equivalent, except that StrNCpy() zero-fills the entire
destination buffer instead of providing just one trailing zero. For
all but a tiny number of callers, that's just overhead rather than
being desirable.
Remove StrNCpy() as it is now unused.
In some cases, namestrcpy() is the more appropriate function to use.
While we're here, simplify the API of namestrcpy(): Remove the return
value, don't check for NULL input. Nothing was using that anyway.
Also, remove a few unused name-related functions.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/44f5e198-36f6-6cdb-7fa9-60e34784daae%402ndquadrant.com
A couple of test cases had connect_timeout=14, a value that seems
to have been plucked from a hat. While it's more than sufficient
for normal cases, slow/overloaded buildfarm machines can get a timeout
failure here, as per recent report from "sungazer". Increase to 180
seconds, which is in line with our typical timeouts elsewhere in
the regression tests.
Back-patch to 9.6; the code looks different in 9.5, and this doesn't
seem to be quite worth the effort to adapt to that.
Report: https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=sungazer&dt=2020-08-04%2007%3A12%3A22
This ought to work much like C's "#elif defined(name)"; but the code
implemented it in a way equivalent to endif followed by ifdef, so that
it didn't matter whether any previous branch of the IF construct had
succeeded. Fix that; add some test cases covering elif and nested IFs;
and improve the documentation, which also seemed a bit confused.
AFAICS the code has been like this since the feature was added in 1999
(commit b57b0e044). So while it's surely wrong, there might be code
out there relying on the current behavior. Hence, don't back-patch
into stable branches. It seems all right to fix it in v13 though.
Per report from Ashutosh Sharma. Reviewed by Ashutosh Sharma and
Michael Meskes.
Discussion: https://postgr.es/m/CAE9k0P=dQk9X0cU2tN49S7a9tv733-e1pVdpB1P-pWJ5PdTktg@mail.gmail.com
Some code paths dedicated to bytea used the structure for varchar. This
did not lead to any actual bugs, as bytea and varchar have the same
definition, but it could become a trap if one of these definitions
changes for a new feature or a bug fix.
Issue introduced by 050710b.
Author: Shenhao Wang
Reviewed-by: Vignesh C, Michael Paquier
Discussion: https://postgr.es/m/07ac7dee1efc44f99d7f53a074420177@G08CNEXMBPEKD06.g08.fujitsu.local
Backpatch-through: 12
GSS-related resources should be cleaned up in pqDropConnection,
not freePGconn, else the wrong things happen when resetting
a connection or trying to switch to a different server.
It's also critical to reset conn->gssenc there.
During connection setup, initialize conn->try_gss at the correct
place, else switching to a different server won't work right.
Remove now-redundant cleanup of GSS resources around one (and, for
some reason, only one) pqDropConnection call in connectDBStart.
Per report from Kyotaro Horiguchi that psql would freeze up,
rather than successfully resetting a GSS-encrypted connection
after a server restart.
This is YA oversight in commit b0b39f72b, so back-patch to v12.
Discussion: https://postgr.es/m/20200710.173803.435804731896516388.horikyota.ntt@gmail.com
Commit 54cd4f045 added some kluges to work around an old glibc bug,
namely that %.*s could misbehave if glibc thought any characters in
the supplied string were incorrectly encoded. Now that we use our
own snprintf.c implementation, we need not worry about that bug (even
if it still exists in the wild). Revert a couple of particularly
ugly hacks, and remove or improve assorted comments.
Note that there can still be encoding-related hazards here: blindly
clipping at a fixed length risks producing wrongly-encoded output
if the clip splits a multibyte character. However, code that's
doing correct multibyte-aware clipping doesn't really need a comment
about that, while code that isn't needs an explanation why not,
rather than a red-herring comment about an obsolete bug.
Discussion: https://postgr.es/m/279428.1593373684@sss.pgh.pa.us
OpenSSL's native reports about problems related to protocol version
restrictions are pretty opaque and inconsistent. When we get an
SSL error that is plausibly due to this, emit a hint message that
includes the range of SSL protocol versions we (think we) are
allowing. This should at least get the user thinking in the right
direction to resolve the problem, even if the hint isn't totally
accurate, which it might not be for assorted reasons.
Back-patch to v13 where we increased the default minimum protocol
version, thereby increasing the risk of this class of failure.
Patch by me, reviewed by Daniel Gustafsson
Discussion: https://postgr.es/m/a9408304-4381-a5af-d259-e55d349ae4ce@2ndquadrant.com
When we initially created this parameter, in commit ff8ca5fad, we left
the default as "allow any protocol version" on grounds of backwards
compatibility. However, that's inconsistent with the backend's default
since b1abfec82; protocol versions prior to 1.2 are not considered very
secure; and OpenSSL has had TLSv1.2 support since 2012, so the number
of PG servers that need a lesser minimum is probably quite small.
On top of those things, it emerges that some popular distros (including
Debian and RHEL) set MinProtocol=TLSv1.2 in openssl.cnf. Thus, far
from having "allow any protocol version" behavior in practice, what
we actually have as things stand is a platform-dependent lower limit.
So, change our minds and set the min version to TLSv1.2. Anybody
wanting to connect with a new libpq to a pre-2012 server can either
set ssl_min_protocol_version=TLSv1 or accept the fallback to non-SSL.
Back-patch to v13 where the aforementioned patches appeared.
Patch by me, reviewed by Daniel Gustafsson
Discussion: https://postgr.es/m/a9408304-4381-a5af-d259-e55d349ae4ce@2ndquadrant.com
access_method, database_name, and index_name are all just name, and
they are not used consistently for their alleged purpose, so remove
them. They have been around since ancient times but have no current
reason for existing. Removing them can simplify future grammar
refactoring.
Discussion: https://www.postgresql.org/message-id/flat/163c00a5-f634-ca52-fc7c-0e53deda8735%402ndquadrant.com
Even when we've concluded that we have a hard write failure on the
socket, we should continue to try to read data. This gives us an
opportunity to collect any final error message that the backend might
have sent before closing the connection; moreover it is the job of
pqReadData not pqSendSome to close the socket once EOF is detected.
Due to an oversight in 1f39a1c06, pqSendSome failed to try to collect
data in the case where we'd already set write_failed. The problem was
masked for ordinary query operations (which really only make one write
attempt anyway), but COPY to the server would continue to send data
indefinitely after a mid-COPY connection loss.
Hence, add pqReadData calls into the paths where pqSendSome drops data
because of write_failed. If we've lost the connection, this will
eventually result in closing the socket and setting CONNECTION_BAD,
which will cause PQputline and siblings to report failure, allowing
the application to terminate the COPY sooner. (Basically this restores
what happened before 1f39a1c06.)
There are related issues that this does not solve; for example, if the
backend sends an error but doesn't drop the connection, we did and
still will keep pumping COPY data as long as the application sends it.
Fixing that will require application-visible behavior changes though,
and anyway it's an ancient behavior that we've had few complaints about.
For now I'm just trying to fix the regression from 1f39a1c06.
Per a complaint from Andres Freund. Back-patch into v12 where
1f39a1c06 came in.
Discussion: https://postgr.es/m/20200603201242.ofvm4jztpqytwfye@alap3.anarazel.de
Since 74a308c, any security-sensitive information gets cleared from
memory this way. This was forgotten in 4dc6355.
Author: Daniel Gustafsson
Reviewed-by: Peter Eisentraut, Michael Paquier
Discussion: https://postgr.es/m/935443BA-D42E-4CE0-B181-1AD79E6DD45A@yesql.se
