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.
This unifies a bunch of ugly #ifdef's in one place. Per discussion,
we only need this where HAVE_UNIX_SOCKETS, so no need to cover Windows.
Marko Kreen, some adjustment by Tom Lane
It turns out the reason we hadn't found out about the portability issues
with our credential-control-message code is that almost no modern platforms
use that code at all; the ones that used to need it now offer getpeereid(),
which we choose first. The last holdout was NetBSD, and they added
getpeereid() as of 5.0. So far as I can tell, the only live platform on
which that code was being exercised was Debian/kFreeBSD, ie, FreeBSD kernel
with Linux userland --- since glibc doesn't provide getpeereid(), we fell
back to the control message code. However, the FreeBSD kernel provides a
LOCAL_PEERCRED socket parameter that's functionally equivalent to Linux's
SO_PEERCRED. That is both much simpler to use than control messages, and
superior because it doesn't require receiving a message from the other end
at just the right time.
Therefore, add code to use LOCAL_PEERCRED when necessary, and rip out all
the credential-control-message code in the backend. (libpq still has such
code so that it can still talk to pre-9.1 servers ... but eventually we can
get rid of it there too.) Clean up related autoconf probes, too.
This means that libpq's requirepeer parameter now works on exactly the same
platforms where the backend supports peer authentication, so adjust the
documentation accordingly.
Even though this only affects the insertion of a parenthesized word,
it's unwise to assume that parentheses can pass through untranslated.
And in any case, the new version is clearer in the code and for
translators.
The code to assemble ldap_get_values_len's output into a single string
wrote the terminating null one byte past where it should. Fix that,
and make some other cosmetic adjustments to make the code a trifle more
readable and more in line with usual Postgres coding style.
Also, free the "result" string when done with it, to avoid a permanent
memory leak.
Bug report and patch by Albe Laurenz, cosmetic adjustments by me.
This would lead to leaking the PGconn structure after an error detected by
conninfo_array_parse(), as well as failing to return a useful error message
in such cases. Backpatch to 9.0 where the error was introduced.
Joseph Adams
Add a new libpq connection option client_encoding (which includes the
existing PGCLIENTENCODING environment variable), which besides an
encoding name accepts a special value "auto" that tries to determine
the encoding from the locale in the client's environment, using the
mechanisms that have been in use in initdb.
psql sets this new connection option to "auto" when running from a
terminal and not overridden by setting PGCLIENTENCODING.
original code by Heikki Linnakangas, with subsequent contributions by
Jaime Casanova, Peter Eisentraut, Stephen Frost, Ibrar Ahmed
libpq connection, per report from Magnus. This happens only on GIT
master and only on Win32 because that is the platform where "" maps to
an IP address (localhost).
Basically, we want to distinguish all cases where the connection was
not made from those where it was. A convenient proxy for this is to
see if we got a message with a SQLSTATE code back from the postmaster.
This presumes that the postmaster will always send us a SQLSTATE in
a failure message, which is true for 7.4 and later postmasters in
every case except fork failure. (We could possibly complicate the
postmaster code to do something about that, but it seems not worth
the trouble, especially since pg_ctl's response for that case should
be to keep waiting anyway.)
If we did get a SQLSTATE from the postmaster, there are basically only
two cases, as per last week's discussion: ERRCODE_CANNOT_CONNECT_NOW
and everything else. Any other error code implies that the postmaster
is in principle willing to accept connections, it just didn't like or
couldn't handle this particular request. We want to make a special
case for ERRCODE_CANNOT_CONNECT_NOW so that "pg_ctl start -w" knows
it should keep waiting.
In passing, pick names for the enum constants that are a tad less
likely to present collision hazards in future.
status, including a status where the server is running but refuses a
postgres connection.
Have pg_ctl use this new function. This fixes the case where pg_ctl
reports that the server is not running (cannot connect) but in fact it
is running.
supplied, also print the IP address. This allows IPv4 and IPv6 failures
to be distinguished. Also useful when a hostname resolves to multiple
IP addresses.
Also, remove use of inet_ntoa() and use our own inet_net_ntop() in all
places, including in libpq, because it is thread-safe.
This adds a libpq connection parameter requirepeer that specifies the user
name that the server process is expected to run under.
reviewed by KaiGai Kohei
This adds four additional connection parameters to libpq: keepalives,
keepalives_idle, keepalives_count, and keepalives_interval.
keepalives default to on, per discussion, but can be turned off by
specifying keepalives=0. The remaining parameters, where supported,
can be used to adjust how often keepalives are sent and how many
can be lost before the connection is broken.
The immediate motivation for this patch is to make sure that
walreceiver will eventually notice if the master reboots without
closing the connection cleanly, but it should be helpful in other
cases as well.
Tollef Fog Heen, Fujii Masao, and me.
additional cases correctly. The original coding failed to load additional
(chain) certificates from the client cert file, meaning that indirectly signed
client certificates didn't work unless one hacked the server's root.crt file
to include intermediate CAs (not the desired approach). Another problem was
that everything got loaded into the shared SSL_context object, which meant
that concurrent connections trying to use different sslcert settings could
well fail due to conflicting over the single available slot for a keyed
certificate.
To fix, get rid of the use of SSL_CTX_set_client_cert_cb(), which is
deprecated anyway in the OpenSSL documentation, and instead just
unconditionally load the client cert and private key during connection
initialization. This lets us use SSL_CTX_use_certificate_chain_file(),
which does the right thing with additional certs, and is lots simpler than
the previous hacking about with BIO-level access. A small disadvantage is
that we have to load the primary client cert a second time with
SSL_use_certificate_file, so that that one ends up in the correct slot
within the connection's SSL object where it can get paired with the key.
Given the other overhead of making an SSL connection, that doesn't seem
worth worrying about.
Per discussion ensuing from bug #5468.
set ferror() but never set feof(). This is known to be the case for recent
glibc when trying to read a directory as a file, and might be true for other
platforms/cases too. Per report from Ed L. (There is more that we ought to
do about his report, but this is one easily identifiable issue.)
If expand_dbname is non-zero and dbname contains an = sign, it is taken as
a conninfo string in exactly the same way as if it had been passed to
PQconnectdb. This is equivalent to the way PQsetdbLogin() works, allowing
PQconnectdbParams() to be a complete alternative.
Also improve the way the new function is called from psql and replace a
previously missed call to PQsetdbLogin() in psql. Additionally use
PQconnectdbParams() for pg_dump and friends, and the bin/scripts
command line utilities such as vacuumdb, createdb, etc.
Finally, update the documentation for the new parameter, as well as the
nuances of precedence in cases where key words are repeated or duplicated
in the conninfo string.
PQconnectStartParams. These are analogous to PQconnectdb and PQconnectStart
respectively. They differ from the legacy functions in that they accept
two NULL-terminated arrays, keywords and values, rather than conninfo
strings. This avoids the need to build the conninfo string in cases
where it might be inconvenient to do so. Includes documentation.
Also modify psql to utilize PQconnectdbParams rather than PQsetdbLogin.
This allows the new config parameter application_name to be set, which
in turn is displayed in the pg_stat_activity view and included in CSV
log entries. This will also ensure both new functions get regularly
exercised.
Patch by Guillaume Lelarge with review and minor adjustments by
Joe Conway.
This includes two new kinds of postmaster processes, walsenders and
walreceiver. Walreceiver is responsible for connecting to the primary server
and streaming WAL to disk, while walsender runs in the primary server and
streams WAL from disk to the client.
Documentation still needs work, but the basics are there. We will probably
pull the replication section to a new chapter later on, as well as the
sections describing file-based replication. But let's do that as a separate
patch, so that it's easier to see what has been added/changed. This patch
also adds a new section to the chapter about FE/BE protocol, documenting the
protocol used by walsender/walreceivxer.
Bump catalog version because of two new functions,
pg_last_xlog_receive_location() and pg_last_xlog_replay_location(), for
monitoring the progress of replication.
Fujii Masao, with additional hacking by me
is made, include it in the startup-packet options. This makes it work more
like every other libpq connection option, in particular it now has the same
response to RESET ALL as the rest. This also saves one network round trip
for new applications using application_name. The cost is that if the server
is pre-8.5, it'll reject the startup packet altogether, forcing us to retry
the entire connection cycle. But on balance we shouldn't be optimizing that
case in preference to the behavior with a new server, especially when doing
so creates visible behavioral oddities. Per discussion.
Tom Lane
Peter Eisentraut
Bruce Momjian
Heikki Linnakangas
Magnus Hagander
Robert Haas
Joe Conway