connections by the superuser only.
This patch replaces the last patch I sent a couple of days ago.
It closes a connection that has not been authorised by a superuser if it would
leave less than the GUC variable ReservedBackends
(superuser_reserved_connections in postgres.conf) backend process slots free
in the SISeg. This differs to the first patch which only reserved the last
ReservedBackends slots in the procState array. This has made the free slot
test more expensive due to the use of a lock.
After thinking about a comment on the first patch I've also made it a fatal
error if the number of reserved slots is not less than the maximum number of
connections.
Nigel J. Andrews
error handling, and simplifies the code that remains. Apparently,
the code that left Berkeley had a whole "error handling subsystem",
which exceptions and whatnot. Since we don't use that anymore,
there's no reason to keep it around.
The regression tests pass with the patch applied. Unless anyone
sees a problem, please apply.
Neil Conway
Attached are a revised set of SSL patches. Many of these patches
are motivated by security concerns, it's not just bug fixes. The key
differences (from stock 7.2.1) are:
*) almost all code that directly uses the OpenSSL library is in two
new files,
src/interfaces/libpq/fe-ssl.c
src/backend/postmaster/be-ssl.c
in the long run, it would be nice to merge these two files.
*) the legacy code to read and write network data have been
encapsulated into read_SSL() and write_SSL(). These functions
should probably be renamed - they handle both SSL and non-SSL
cases.
the remaining code should eliminate the problems identified
earlier, albeit not very cleanly.
*) both front- and back-ends will send a SSL shutdown via the
new close_SSL() function. This is necessary for sessions to
work properly.
(Sessions are not yet fully supported, but by cleanly closing
the SSL connection instead of just sending a TCP FIN packet
other SSL tools will be much happier.)
*) The client certificate and key are now expected in a subdirectory
of the user's home directory. Specifically,
- the directory .postgresql must be owned by the user, and
allow no access by 'group' or 'other.'
- the file .postgresql/postgresql.crt must be a regular file
owned by the user.
- the file .postgresql/postgresql.key must be a regular file
owned by the user, and allow no access by 'group' or 'other'.
At the current time encrypted private keys are not supported.
There should also be a way to support multiple client certs/keys.
*) the front-end performs minimal validation of the back-end cert.
Self-signed certs are permitted, but the common name *must*
match the hostname used by the front-end. (The cert itself
should always use a fully qualified domain name (FDQN) in its
common name field.)
This means that
psql -h eris db
will fail, but
psql -h eris.example.com db
will succeed. At the current time this must be an exact match;
future patches may support any FQDN that resolves to the address
returned by getpeername(2).
Another common "problem" is expiring certs. For now, it may be
a good idea to use a very-long-lived self-signed cert.
As a compile-time option, the front-end can specify a file
containing valid root certificates, but it is not yet required.
*) the back-end performs minimal validation of the client cert.
It allows self-signed certs. It checks for expiration. It
supports a compile-time option specifying a file containing
valid root certificates.
*) both front- and back-ends default to TLSv1, not SSLv3/SSLv2.
*) both front- and back-ends support DSA keys. DSA keys are
moderately more expensive on startup, but many people consider
them preferable than RSA keys. (E.g., SSH2 prefers DSA keys.)
*) if /dev/urandom exists, both client and server will read 16k
of randomization data from it.
*) the server can read empheral DH parameters from the files
$DataDir/dh512.pem
$DataDir/dh1024.pem
$DataDir/dh2048.pem
$DataDir/dh4096.pem
if none are provided, the server will default to hardcoded
parameter files provided by the OpenSSL project.
Remaining tasks:
*) the select() clauses need to be revisited - the SSL abstraction
layer may need to absorb more of the current code to avoid rare
deadlock conditions. This also touches on a true solution to
the pg_eof() problem.
*) the SIGPIPE signal handler may need to be revisited.
*) support encrypted private keys.
*) sessions are not yet fully supported. (SSL sessions can span
multiple "connections," and allow the client and server to avoid
costly renegotiations.)
*) makecert - a script that creates back-end certs.
*) pgkeygen - a tool that creates front-end certs.
*) the whole protocol issue, SASL, etc.
*) certs are fully validated - valid root certs must be available.
This is a hassle, but it means that you *can* trust the identity
of the server.
*) the client library can handle hardcoded root certificates, to
avoid the need to copy these files.
*) host name of server cert must resolve to IP address, or be a
recognized alias. This is more liberal than the previous
iteration.
*) the number of bytes transferred is tracked, and the session
key is periodically renegotiated.
*) basic cert generation scripts (mkcert.sh, pgkeygen.sh). The
configuration files have reasonable defaults for each type
of use.
Bear Giles
are motivated by security concerns, it's not just bug fixes. The key
differences (from stock 7.2.1) are:
*) almost all code that directly uses the OpenSSL library is in two
new files,
src/interfaces/libpq/fe-ssl.c
src/backend/postmaster/be-ssl.c
in the long run, it would be nice to merge these two files.
*) the legacy code to read and write network data have been
encapsulated into read_SSL() and write_SSL(). These functions
should probably be renamed - they handle both SSL and non-SSL
cases.
the remaining code should eliminate the problems identified
earlier, albeit not very cleanly.
*) both front- and back-ends will send a SSL shutdown via the
new close_SSL() function. This is necessary for sessions to
work properly.
(Sessions are not yet fully supported, but by cleanly closing
the SSL connection instead of just sending a TCP FIN packet
other SSL tools will be much happier.)
*) The client certificate and key are now expected in a subdirectory
of the user's home directory. Specifically,
- the directory .postgresql must be owned by the user, and
allow no access by 'group' or 'other.'
- the file .postgresql/postgresql.crt must be a regular file
owned by the user.
- the file .postgresql/postgresql.key must be a regular file
owned by the user, and allow no access by 'group' or 'other'.
At the current time encrypted private keys are not supported.
There should also be a way to support multiple client certs/keys.
*) the front-end performs minimal validation of the back-end cert.
Self-signed certs are permitted, but the common name *must*
match the hostname used by the front-end. (The cert itself
should always use a fully qualified domain name (FDQN) in its
common name field.)
This means that
psql -h eris db
will fail, but
psql -h eris.example.com db
will succeed. At the current time this must be an exact match;
future patches may support any FQDN that resolves to the address
returned by getpeername(2).
Another common "problem" is expiring certs. For now, it may be
a good idea to use a very-long-lived self-signed cert.
As a compile-time option, the front-end can specify a file
containing valid root certificates, but it is not yet required.
*) the back-end performs minimal validation of the client cert.
It allows self-signed certs. It checks for expiration. It
supports a compile-time option specifying a file containing
valid root certificates.
*) both front- and back-ends default to TLSv1, not SSLv3/SSLv2.
*) both front- and back-ends support DSA keys. DSA keys are
moderately more expensive on startup, but many people consider
them preferable than RSA keys. (E.g., SSH2 prefers DSA keys.)
*) if /dev/urandom exists, both client and server will read 16k
of randomization data from it.
*) the server can read empheral DH parameters from the files
$DataDir/dh512.pem
$DataDir/dh1024.pem
$DataDir/dh2048.pem
$DataDir/dh4096.pem
if none are provided, the server will default to hardcoded
parameter files provided by the OpenSSL project.
Remaining tasks:
*) the select() clauses need to be revisited - the SSL abstraction
layer may need to absorb more of the current code to avoid rare
deadlock conditions. This also touches on a true solution to
the pg_eof() problem.
*) the SIGPIPE signal handler may need to be revisited.
*) support encrypted private keys.
*) sessions are not yet fully supported. (SSL sessions can span
multiple "connections," and allow the client and server to avoid
costly renegotiations.)
*) makecert - a script that creates back-end certs.
*) pgkeygen - a tool that creates front-end certs.
*) the whole protocol issue, SASL, etc.
*) certs are fully validated - valid root certs must be available.
This is a hassle, but it means that you *can* trust the identity
of the server.
*) the client library can handle hardcoded root certificates, to
avoid the need to copy these files.
*) host name of server cert must resolve to IP address, or be a
recognized alias. This is more liberal than the previous
iteration.
*) the number of bytes transferred is tracked, and the session
key is periodically renegotiated.
*) basic cert generation scripts (mkcert.sh, pgkeygen.sh). The
configuration files have reasonable defaults for each type
of use.
Bear Giles
> Changes to avoid collisions with WIN32 & MFC names...
> 1. Renamed:
> a. PROC => PGPROC
> b. GetUserName() => GetUserNameFromId()
> c. GetCurrentTime() => GetCurrentDateTime()
> d. IGNORE => IGNORE_DTF in include/utils/datetime.h & utils/adt/datetim
>
> 2. Added _P to some lex/yacc tokens:
> CONST, CHAR, DELETE, FLOAT, GROUP, IN, OUT
Jan
GUC support. It's now possible to set datestyle, timezone, and
client_encoding from postgresql.conf and per-database or per-user
settings. Also, implement rollback of SET commands that occur in a
transaction that later fails. Create a SET LOCAL var = value syntax
that sets the variable only for the duration of the current transaction.
All per previous discussions in pghackers.
As proof of concept, provide an alternate implementation based on POSIX
semaphores. Also push the SysV shared-memory implementation into a
separate file so that it can be replaced conveniently.
A new pg_hba.conf column, USER
Allow specifiction of lists of users separated by commas
Allow group names specified by +
Allow include files containing lists of users specified by @
Allow lists of databases, and database files
Allow samegroup in database column to match group name matching dbname
Removal of secondary password files
Remove pg_passwd utility
Lots of code cleanup in user.c and hba.c
New data/global/pg_pwd format
New data/global/pg_group file
per recent pghackers discussion: force a new WAL record at first nextval
after a checkpoint, and ensure that xlog is flushed to disk if a nextval
record is the only thing emitted by a transaction.
when to send what to which, prevent recursion by introducing new COMMERROR
elog level for client-communication problems, get rid of direct writes
to stderr in backend/libpq files, prevent non-error elogs from going to
client during the authentication cycle.
now just below FATAL in server_min_messages. Added more text to
highlight ordering difference between it and client_min_messages.
---------------------------------------------------------------------------
REALLYFATAL => PANIC
STOP => PANIC
New INFO level the prints to client by default
New LOG level the prints to server log by default
Cause VACUUM information to print only to the client
NOTICE => INFO where purely information messages are sent
DEBUG => LOG for purely server status messages
DEBUG removed, kept as backward compatible
DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1 added
DebugLvl removed in favor of new DEBUG[1-5] symbols
New server_min_messages GUC parameter with values:
DEBUG[5-1], INFO, NOTICE, ERROR, LOG, FATAL, PANIC
New client_min_messages GUC parameter with values:
DEBUG[5-1], LOG, INFO, NOTICE, ERROR, FATAL, PANIC
Server startup now logged with LOG instead of DEBUG
Remove debug_level GUC parameter
elog() numbers now start at 10
Add test to print error message if older elog() values are passed to elog()
Bootstrap mode now has a -d that requires an argument, like postmaster
the first call of localtime() in a process will read /usr/lib/tztab or
local equivalent. Better to do this once in the postmaster and inherit
the data by fork() than to have to do it during every backend start.
to the client before closing the connection. Before 7.2 this was done
correctly, but new code would simply close the connection with no report
to the client.
so that only one signal number is used not three. Flags in shared
memory tell the reason(s) for the current signal. This method is
extensible to handle more signal reasons without chewing up even more
signal numbers, but the immediate reason is to keep pg_pwd reloads
separate from SIGHUP processing in the postmaster.
Also clean up some problems in the postmaster with delayed response to
checkpoint status changes --- basically, it wouldn't schedule a checkpoint
if it wasn't getting connection requests on a regular basis.
postmaster children before client auth step. Postmaster now rereads
pg_pwd on receipt of SIGHUP, the same way that pg_hba.conf is handled.
No cycles need be expended to validate password cache validity during
connection startup.
environment strings need to be moved around, do so when called from
initial startup (main.c), not in init_ps_status. This eliminates the
former risk of invalidating saved environment-string pointers, since
no code has yet had a chance to grab any such pointers when main.c
is running.
per suggestion from Peter. Simplify several APIs by transmitting the
original argv location directly from main.c to ps_status.c, instead of
passing it down through several levels of subroutines.
subprocesses; perhaps this will fix portability problem just noted by
Lockhart. Also, move test for bad permissions of DataDir to a more
logical place.
bootstrap) check for a valid PG_VERSION file before looking at anything
else in the data directory. This fixes confusing error report when
trying to start current sources in a pre-7.1 data directory.
Per trouble report from Rich Shepard 10/18/01.
just after receipt of the startup packet. Now, postmaster children
that are waiting for client authentication response will show as
'postgres: user database host authentication'. Also, do an
init_ps_display for startup/shutdown/checkpoint subprocesses,
so that they are readily identifiable as well. Fix an obscure race
condition that could lead to Assert failure in the postmaster ---
attempting to start a checkpoint process before any connections have
been received led to calling PostmasterRandom before setting random_seed.
a hung client or lost connection can't indefinitely block a postmaster
child (not to mention the possibility of deliberate DoS attacks).
Timeout is controlled by new authentication_timeout GUC variable,
which I set to 60 seconds by default ... does that seem reasonable?
We will no longer try to send elog messages to the client before we have
initialized backend libpq (oops); however, reporting bogus commandline
switches via elog does work now (not irrelevant, because of PGOPTIONS).
Fix problem with inappropriate sending of checkpoint-process messages
to stderr.
for them, and making them just wastes time during backend startup/shutdown.
Also, remove compile-time MAXBACKENDS limit per long-ago proposal.
You can now set MaxBackends as high as your kernel can stand without
any reconfiguration/recompilation.
Make sure it exits immediately when collector process dies --- in old code,
buffer process would hang around and compete with the new buffer process
for packets. Make sure it doesn't block on writing the pipe when the
collector falls more than a pipeload behind. Avoid leaking pgstats FDs
into every backend.
platforms system(2) gets confused unless the signal handler is set to
SIG_DFL, not SIG_IGN. pgstats.c now uses pqsignal() as it should,
not signal(). Also, arrange for the stats collector process to show
a reasonable ID in 'ps', rather than looking like a postmaster.
number in the data structure so that we can give at least a minimally
useful idea of where the mistake is when we issue syntax error messages.
Move the ClientAuthentication() call to where it should have been in
the first place, so that postmaster memory releasing can happen in a
reasonable place also. Update obsolete comments, correct one real bug
(auth_argument was not picked up correctly).
immediately, we will fork a child even if the database state does not
permit connections to be accepted (eg, we are in recovery mode).
The child process will correctly reject the connection and exit as
soon as it's finished collecting the connection request message.
However, this means that reaper() must be prepared to see child
process exit signals even while it's waiting for startup or shutdown
process to finish. As was, a connection request arriving during a
database recovery or shutdown would cause postmaster abort.
> > secure_ctx changes too. it will be PGC_BACKEND after '-p'.
>
> Oh, okay, I missed that part. Could we see the total state of the
> patch --- ie, a diff against current CVS, not a bunch of deltas?
> I've gotten confused about what's in and what's out.
Ok, here it is. Cleared the ctx comment too - after -p
it will be PGC_BACKEND in any case.
Marko Kreen
a new postmaster child process. This should eliminate problems with
authentication blocking (e.g., ident, SSL init) and also reduce problems
with the accept queue filling up under heavy load.
The option to send elog output to a different file per backend (postgres -o)
has been disabled for now because the initialization would have to happen
in a different order and it's not clear we want to keep this anyway.
Here is Tomified version of my 2 pending patches.
Dropped the set_.._real change as it is not needed.
Desc would be:
* use GUC for settings from cmdline
Marko Kreen
detected sooner in backend startup, and is treated as an expected error
(it gives 'Sorry, too many clients already' now). This allows us not
to have to enforce the MaxBackends limit exactly in the postmaster.
Also, remove ProcRemove() and fold its functionality into ProcKill().
There's no good reason for a backend not to be responsible for removing
its PROC entry, and there are lots of good reasons for the postmaster
not to be touching shared-memory data structures.
datatypes, not only strings. parse_hook is useless for bool, I suppose,
but it seems possibly useful for int and double to apply variable-specific
constraints that are more complex than simple range limits. assign_hook
is definitely useful for all datatypes --- we need it right now for bool
to support date cache reset when changing Australian timezone rule setting.
Also, clean up some residual problems with the reset all/show all patch,
including memory leaks and mistaken reset of PostPortNumber. It seems
best that RESET ALL not touch variables that don't have SUSET or
USERSET context.
directory (which can be made a symlink to put temp files on another disk).
Add code to delete leftover temp files during postmaster startup.
Bruce, with some kibitzing from Tom.
Python) to support shared extension modules, I have learned that Guido
prefers the style of the attached patch to solve the above problem.
I feel that this solution is particularly appropriate in this case
because the following:
PglargeType
PgType
PgQueryType
are already being handled in the way that I am proposing for PgSourceType.
Jason Tishler
* Store two past checkpoint locations, not just one, in pg_control.
On startup, we fall back to the older checkpoint if the newer one
is unreadable. Also, a physical copy of the newest checkpoint record
is kept in pg_control for possible use in disaster recovery (ie,
complete loss of pg_xlog). Also add a version number for pg_control
itself. Remove archdir from pg_control; it ought to be a GUC
parameter, not a special case (not that it's implemented yet anyway).
* Suppress successive checkpoint records when nothing has been entered
in the WAL log since the last one. This is not so much to avoid I/O
as to make it actually useful to keep track of the last two
checkpoints. If the things are right next to each other then there's
not a lot of redundancy gained...
* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
on alternate bytes. Polynomial borrowed from ECMA DLT1 standard.
* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.
* Change XID allocation to work more like OID allocation. (This is of
dubious necessity, but I think it's a good idea anyway.)
* Fix a number of minor bugs, such as off-by-one logic for XLOG file
wraparound at the 4 gig mark.
* Add documentation and clean up some coding infelicities; move file
format declarations out to include files where planned contrib
utilities can get at them.
* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
every CHECKPOINT_TIMEOUT seconds, whichever comes first. It is also
possible to force a checkpoint by sending SIGUSR1 to the postmaster
(undocumented feature...)
* Defend against kill -9 postmaster by storing shmem block's key and ID
in postmaster.pid lockfile, and checking at startup to ensure that no
processes are still connected to old shmem block (if it still exists).
* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
stop, for symmetry with postmaster and xlog utilities. Clean up signal
handling in bootstrap.c so that xlog utilities launched by postmaster
will react to signals better.
* Standalone bootstrap now grabs lockfile in target directory, as added
insurance against running it in parallel with live postmaster.
are now separate files "postgres.h" and "postgres_fe.h", which are meant
to be the primary include files for backend .c files and frontend .c files
respectively. By default, only include files meant for frontend use are
installed into the installation include directory. There is a new make
target 'make install-all-headers' that adds the whole content of the
src/include tree to the installed fileset, for use by people who want to
develop server-side code without keeping the complete source tree on hand.
Cleaned up a whole lot of crufty and inconsistent header inclusions.
any other client connections that may exist (which would only happen if
another client is currently in the authentication cycle). This avoids
wastage of open descriptors in a child. It might also explain peculiar
behaviors like not closing connections when expected, since the kernel
will probably not signal EOF as long as some other backend is randomly
holding open a reference to the connection, even if the client went away
long since ...
actually) to ensure that its file access time doesn't get old enough to
tempt a /tmp directory cleaner to remove it. Still another reason we
should never have put the sockets in /tmp in the first place ...
observed by Inoue. Also, don't call ProcRemove() from postmaster if we
have detected a backend crash --- too risky if shared memory is corrupted.
It's not needed anyway, considering we are going to reinitialize shared
memory and semaphores as soon as the last child is dead.
>> xlog.c : special case for beos to avoid 'link' which does not work yet
>> beos/sem.c : implementation of new sem_ctl call (GETPID) and a new
>sem_op
>> flag (IPCNOWAIT)
>> dynloader/beos.c : add a verification of symbol validity (seem that
the
>> loader sometime return OK with an invalid symbol)
>> postmaster.c : add beos forking support for the new checkpoint
process
>> postgres.c : remove beos special case for getrusage
>> beos.h : Correction of a bas definition of AF_UNIX, misc defnitions
>>
>>
>> thanks
>>
>>
>> cyril
Cyril VELTER
might change it. Experimentation shows that the signal handler call
mechanism does not save/restore errno for you, at least not on Linux
or HPUX, so this is definitely a real risk.
postmaster, because it isn't updated after forking away from the terminal.
Apparently it's not used anyplace in the postmaster ... but seems best
to make it show the correct PID ...
socket file, in favor of having an ordinary lockfile beside the socket file.
Clean up a few robustness problems in the lockfile code. If postmaster is
going to reject a connection request based on database state, it will now
tell you so before authentication exchange not after. (Of course, a failure
after is still possible if conditions change meanwhile, but this makes life
easier for a yet-to-be-written pg_ping utility.)
IPC key assignment will now work correctly even when multiple postmasters
are using same logical port number (which is possible given -k switch).
There is only one shared-mem segment per postmaster now, not 3.
Rip out broken code for non-TAS case in bufmgr and xlog, substitute a
complete S_LOCK emulation using semaphores in spin.c. TAS and non-TAS
logic is now exactly the same.
When deadlock is detected, "Deadlock detected" is now the elog(ERROR)
message, rather than a NOTICE that comes out before an unhelpful ERROR.
re-adopt these settings at every postmaster or standalone-backend startup.
This should fix problems with indexes becoming corrupt due to failure to
provide consistent locale environment for postmaster at all times. Also,
refuse to start up a non-locale-enabled compilation in a database originally
initdb'd with a non-C locale. Suppress LIKE index optimization if locale
is not "C" or "POSIX" (are there any other locales where it's safe?).
Issue NOTICE during initdb if selected locale disables LIKE optimization.
cloned, rather than always cloning template1. Modify initdb to generate
two identical databases rather than one, template0 and template1.
Connections to template0 are disallowed, so that it will always remain
in its virgin as-initdb'd state. pg_dumpall now dumps databases with
restore commands that say CREATE DATABASE foo WITH TEMPLATE = template0.
This allows proper behavior when there is user-added data in template1.
initdb forced!
