On 17.12.2020 9:31, Pavel Stehule wrote:
st 16. 12. 2020 v 20:38 odesílatel Pavel Stehule
<pavel.steh...@gmail.com <mailto:pavel.steh...@gmail.com>> napsal:
Attached please find new versoin of the patch based on
on_connect_event_trigger_WITH_SUGGESTED_UPDATES.patch
So there is still only "disable_client_connection_trigger"
GUC? because we need possibility to disable client connect
triggers and there is no such need for other event types.
As you suggested have added "dathaslogontriggers" flag which
is set when client connection trigger is created.
This flag is never cleaned (to avoid visibility issues
mentioned in my previous mail).
This is much better - I don't see any slowdown when logon trigger
is not defined
I did some benchmarks and looks so starting language handler is
relatively expensive - it is about 25% and starting handler like
event trigger has about 35%. But this problem can be solved later
and elsewhere.
I prefer the inverse form of disable_connection_trigger. Almost
all GUC are in positive form - so enable_connection_triggger is better
I don't think so current handling dathaslogontriggers is good for
production usage. The protection against race condition can be
solved by lock on pg_event_trigger
I thought about it, and probably the counter of connect triggers will
be better there. The implementation will be simpler and more robust.
I prefer to implement different approach: unset dathaslogontriggers flag
in event trigger itself when no triggers are returned by
EventTriggerCommonSetup.
I am using double checking to prevent race condition.
The main reason for this approach is that dropping of triggers is not
done in event_trigger.c: it is done by generic code for all resources.
It seems to be there is no right place where decrementing of trigger
counters can be inserted.
Also I prefer to keep all logon-trigger specific code in one file.
Also, as you suggested, I renamed disable_connection_trigger to
enable_connection_trigger.
New version of the patch is attached.
--
Konstantin Knizhnik
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index f810789..45d30b3 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -996,6 +996,23 @@ include_dir 'conf.d'
</listitem>
</varlistentry>
+ <varlistentry id="guc-enable-client-connection-trigger" xreflabel="enable_client_connection_trigger">
+ <term><varname>enable_client_connection_trigger</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>enable_client_connection_trigger</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Enables firing the <literal>client_connection</literal>
+ trigger when a client connects. This parameter is switched on by default.
+ Errors in trigger code can prevent user to login to the system.
+ I this case disabling this parameter in connection string can solve the problem:
+ <literal>psql "dbname=postgres options='-c enable_client_connection_trigger=false'".
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</sect2>
diff --git a/doc/src/sgml/event-trigger.sgml b/doc/src/sgml/event-trigger.sgml
index 60366a9..ae40a8e 100644
--- a/doc/src/sgml/event-trigger.sgml
+++ b/doc/src/sgml/event-trigger.sgml
@@ -28,6 +28,7 @@
An event trigger fires whenever the event with which it is associated
occurs in the database in which it is defined. Currently, the only
supported events are
+ <literal>client_connection</literal>,
<literal>ddl_command_start</literal>,
<literal>ddl_command_end</literal>,
<literal>table_rewrite</literal>
@@ -36,6 +37,29 @@
</para>
<para>
+ The <literal>client_connection</literal> event occurs when a client connection
+ to the server is established.
+ There are two mechanisms for dealing with any bugs in a trigger procedure for
+ this event which might prevent successful login to the system:
+ <itemizedlist>
+ <listitem>
+ <para>
+ The configuration parameter <literal>enable_client_connection_trigger</literal>
+ makes it possible to disable firing the <literal>client_connection</literal>
+ trigger when a client connects.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Errors in the <literal>client_connection</literal> trigger procedure are
+ ignored for superuser. An error message is delivered to the client as
+ <literal>NOTICE</literal> in this case.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
+
+ <para>
The <literal>ddl_command_start</literal> event occurs just before the
execution of a <literal>CREATE</literal>, <literal>ALTER</literal>, <literal>DROP</literal>,
<literal>SECURITY LABEL</literal>,
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index f27c3fe..8646db7 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -560,6 +560,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
new_record[Anum_pg_database_datctype - 1] =
DirectFunctionCall1(namein, CStringGetDatum(dbctype));
new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
+ new_record[Anum_pg_database_dathaslogontriggers - 1] = BoolGetDatum(false);
new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(dballowconnections);
new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
new_record[Anum_pg_database_datlastsysoid - 1] = ObjectIdGetDatum(src_lastsysoid);
@@ -1627,7 +1628,7 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
new_record_repl[Anum_pg_database_datconnlimit - 1] = true;
}
-
+ new_record[Anum_pg_database_dathaslogontriggers - 1] = BoolGetDatum(datform->dathaslogontriggers);
newtuple = heap_modify_tuple(tuple, RelationGetDescr(rel), new_record,
new_record_nulls, new_record_repl);
CatalogTupleUpdate(rel, &tuple->t_self, newtuple);
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index 3ffba4e..855b656 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -20,6 +20,7 @@
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/objectaccess.h"
+#include "catalog/pg_database.h"
#include "catalog/pg_event_trigger.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_opclass.h"
@@ -43,11 +44,14 @@
#include "utils/builtins.h"
#include "utils/evtcache.h"
#include "utils/fmgroids.h"
+#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/syscache.h"
+bool enable_client_connection_trigger;
+
typedef struct EventTriggerQueryState
{
/* memory context for this state's objects */
@@ -130,6 +134,7 @@ CreateEventTrigger(CreateEventTrigStmt *stmt)
if (strcmp(stmt->eventname, "ddl_command_start") != 0 &&
strcmp(stmt->eventname, "ddl_command_end") != 0 &&
strcmp(stmt->eventname, "sql_drop") != 0 &&
+ strcmp(stmt->eventname, "client_connection") != 0 &&
strcmp(stmt->eventname, "table_rewrite") != 0)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -293,6 +298,23 @@ insert_event_trigger_tuple(const char *trigname, const char *eventname, Oid evtO
CatalogTupleInsert(tgrel, tuple);
heap_freetuple(tuple);
+ if (strcmp(eventname, "client_connection") == 0)
+ {
+ Form_pg_database db;
+ Relation pg_db = table_open(DatabaseRelationId, RowExclusiveLock);
+ /* Set dathaslogontriggers flag in pg_database */
+ tuple = SearchSysCacheCopy1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
+ if (!HeapTupleIsValid(tuple))
+ elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
+ db = (Form_pg_database) GETSTRUCT(tuple);
+ if (!db->dathaslogontriggers)
+ {
+ db->dathaslogontriggers = true;
+ CatalogTupleUpdate(pg_db, &tuple->t_self, tuple);
+ }
+ table_close(pg_db, RowExclusiveLock);
+ }
+
/* Depend on owner. */
recordDependencyOnOwner(EventTriggerRelationId, trigoid, evtOwner);
@@ -562,6 +584,9 @@ EventTriggerCommonSetup(Node *parsetree,
ListCell *lc;
List *runlist = NIL;
+ /* Get the command tag. */
+ tag = parsetree ? CreateCommandTag(parsetree) : CMDTAG_CONNECT;
+
/*
* We want the list of command tags for which this procedure is actually
* invoked to match up exactly with the list that CREATE EVENT TRIGGER
@@ -577,22 +602,18 @@ EventTriggerCommonSetup(Node *parsetree,
* relevant command tag.
*/
#ifdef USE_ASSERT_CHECKING
+ if (event == EVT_DDLCommandStart ||
+ event == EVT_DDLCommandEnd ||
+ event == EVT_SQLDrop ||
+ event == EVT_Connect)
{
- CommandTag dbgtag;
-
- dbgtag = CreateCommandTag(parsetree);
- if (event == EVT_DDLCommandStart ||
- event == EVT_DDLCommandEnd ||
- event == EVT_SQLDrop)
- {
- if (!command_tag_event_trigger_ok(dbgtag))
- elog(ERROR, "unexpected command tag \"%s\"", GetCommandTagName(dbgtag));
- }
- else if (event == EVT_TableRewrite)
- {
- if (!command_tag_table_rewrite_ok(dbgtag))
- elog(ERROR, "unexpected command tag \"%s\"", GetCommandTagName(dbgtag));
- }
+ if (!command_tag_event_trigger_ok(tag))
+ elog(ERROR, "unexpected command tag \"%s\"", GetCommandTagName(tag));
+ }
+ else if (event == EVT_TableRewrite)
+ {
+ if (!command_tag_table_rewrite_ok(tag))
+ elog(ERROR, "unexpected command tag \"%s\"", GetCommandTagName(tag));
}
#endif
@@ -601,9 +622,6 @@ EventTriggerCommonSetup(Node *parsetree,
if (cachelist == NIL)
return NIL;
- /* Get the command tag. */
- tag = CreateCommandTag(parsetree);
-
/*
* Filter list of event triggers by command tag, and copy them into our
* memory context. Once we start running the command triggers, or indeed
@@ -800,6 +818,117 @@ EventTriggerSQLDrop(Node *parsetree)
list_free(runlist);
}
+static bool
+DatabaseHasLogonTriggers(void)
+{
+ bool has_logon_triggers;
+ HeapTuple tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
+
+ if (!HeapTupleIsValid(tuple))
+ elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
+
+ has_logon_triggers = ((Form_pg_database) GETSTRUCT(tuple))->dathaslogontriggers;
+ ReleaseSysCache(tuple);
+ return has_logon_triggers;
+}
+
+/*
+ * Fire connect triggers.
+ */
+void
+EventTriggerOnConnect(void)
+{
+ List *runlist;
+ EventTriggerData trigdata;
+
+ /*
+ * See EventTriggerDDLCommandStart for a discussion about why event
+ * triggers are disabled in single user mode.
+ */
+ if (!IsUnderPostmaster
+ || !OidIsValid(MyDatabaseId)
+ || !enable_client_connection_trigger)
+ return;
+
+ StartTransactionCommand();
+
+ if (DatabaseHasLogonTriggers())
+ {
+ runlist = EventTriggerCommonSetup(NULL,
+ EVT_Connect, "connect",
+ &trigdata);
+
+ if (runlist != NIL)
+ {
+ MemoryContext old_context = CurrentMemoryContext;
+ bool is_superuser = superuser();
+ /*
+ * Make sure anything the main command did will be visible to the event
+ * triggers.
+ */
+ CommandCounterIncrement();
+
+ /* Run the triggers. */
+ PG_TRY();
+ {
+ EventTriggerInvoke(runlist, &trigdata);
+ list_free(runlist);
+ }
+ PG_CATCH();
+ {
+ ErrorData* error;
+ /*
+ * Try to ignore error for superuser to make it possible to login even in case of errors
+ * during trigger execution
+ */
+ if (!is_superuser)
+ PG_RE_THROW();
+
+ MemoryContextSwitchTo(old_context);
+ error = CopyErrorData();
+ FlushErrorState();
+ elog(NOTICE, "client_connection trigger failed with message: %s", error->message);
+ AbortCurrentTransaction();
+ return;
+ }
+ PG_END_TRY();
+ }
+ else
+ {
+ /* Runtlist is empty: clear dathaslogontriggers flag
+ */
+ Relation pg_db = table_open(DatabaseRelationId, RowExclusiveLock);
+ HeapTuple tuple = SearchSysCacheCopy1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
+ Form_pg_database db;
+
+ if (!HeapTupleIsValid(tuple))
+ elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
+
+ db = (Form_pg_database) GETSTRUCT(tuple);
+ if (db->dathaslogontriggers)
+ {
+ db->dathaslogontriggers = false;
+ CatalogTupleUpdate(pg_db, &tuple->t_self, tuple);
+ /*
+ * There can be race condition: event trigger may be added after we have scanned
+ * pg_event_trigger table. Repeat this test nuder pg_database table lock.
+ */
+ AcceptInvalidationMessages();
+ runlist = EventTriggerCommonSetup(NULL,
+ EVT_Connect, "connect",
+ &trigdata);
+ if (runlist != NULL) /* if list is not empty, then restore the flag */
+ {
+ db->dathaslogontriggers = true;
+ CatalogTupleUpdate(pg_db, &tuple->t_self, tuple);
+ }
+ }
+ table_close(pg_db, RowExclusiveLock);
+ }
+ }
+ CommitTransactionCommand();
+}
+
/*
* Fire table_rewrite triggers.
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 3679799..ce9b98e 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -42,6 +42,7 @@
#include "catalog/pg_type.h"
#include "commands/async.h"
#include "commands/prepare.h"
+#include "commands/event_trigger.h"
#include "executor/spi.h"
#include "jit/jit.h"
#include "libpq/libpq.h"
@@ -167,6 +168,9 @@ static ProcSignalReason RecoveryConflictReason;
static MemoryContext row_description_context = NULL;
static StringInfoData row_description_buf;
+/* Hook for plugins to get control at start of session */
+client_connection_hook_type client_connection_hook = EventTriggerOnConnect;
+
/* ----------------------------------------------------------------
* decls for routines only used in this file
* ----------------------------------------------------------------
@@ -4012,6 +4016,11 @@ PostgresMain(int argc, char *argv[],
if (!IsUnderPostmaster)
PgStartTime = GetCurrentTimestamp();
+ if (client_connection_hook)
+ {
+ (*client_connection_hook) ();
+ }
+
/*
* POSTGRES main processing loop begins here
*
diff --git a/src/backend/utils/cache/evtcache.c b/src/backend/utils/cache/evtcache.c
index 0427795..c621b8f 100644
--- a/src/backend/utils/cache/evtcache.c
+++ b/src/backend/utils/cache/evtcache.c
@@ -168,6 +168,8 @@ BuildEventTriggerCache(void)
event = EVT_SQLDrop;
else if (strcmp(evtevent, "table_rewrite") == 0)
event = EVT_TableRewrite;
+ else if (strcmp(evtevent, "client_connection") == 0)
+ event = EVT_Connect;
else
continue;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 245a347..e42fc0e 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -43,6 +43,7 @@
#include "commands/async.h"
#include "commands/prepare.h"
#include "commands/trigger.h"
+#include "commands/event_trigger.h"
#include "commands/user.h"
#include "commands/vacuum.h"
#include "commands/variable.h"
@@ -928,6 +929,18 @@ static const unit_conversion time_unit_conversion_table[] =
static struct config_bool ConfigureNamesBool[] =
{
{
+ {"enable_client_connection_trigger", PGC_SU_BACKEND, DEVELOPER_OPTIONS,
+ gettext_noop("Enables the client_connection event trigger."),
+ gettext_noop("In case of errors in the ON client_connection EVENT TRIGGER procedure, "
+ "this parameter can be used to disable trigger activation "
+ "and provide access to the database."),
+ GUC_EXPLAIN
+ },
+ &enable_client_connection_trigger,
+ true,
+ NULL, NULL, NULL
+ },
+ {
{"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of sequential-scan plans."),
NULL,
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index dc1d41d..a9a7c1f 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -2726,6 +2726,7 @@ dumpDatabase(Archive *fout)
i_datacl,
i_rdatacl,
i_datistemplate,
+ i_dathaslogontriggers,
i_datconnlimit,
i_tablespace;
CatalogId dbCatId;
@@ -2738,6 +2739,7 @@ dumpDatabase(Archive *fout)
*datacl,
*rdatacl,
*datistemplate,
+ *dathaslogontriggers,
*datconnlimit,
*tablespace;
uint32 frozenxid,
@@ -2756,7 +2758,7 @@ dumpDatabase(Archive *fout)
* (pg_init_privs) are not supported on databases, so this logic cannot
* make use of buildACLQueries().
*/
- if (fout->remoteVersion >= 90600)
+ if (fout->remoteVersion >= 140000)
{
appendPQExpBuffer(dbQry, "SELECT tableoid, oid, datname, "
"(%s datdba) AS dba, "
@@ -2782,7 +2784,41 @@ dumpDatabase(Archive *fout)
" AS permp(orig_acl) "
" WHERE acl = orig_acl)) AS rdatacls) "
" AS rdatacl, "
- "datistemplate, datconnlimit, "
+ "datistemplate, datconnlimit, dathaslogontriggers, "
+ "(SELECT spcname FROM pg_tablespace t WHERE t.oid = dattablespace) AS tablespace, "
+ "shobj_description(oid, 'pg_database') AS description "
+
+ "FROM pg_database "
+ "WHERE datname = current_database()",
+ username_subquery);
+ }
+ else if (fout->remoteVersion >= 90600)
+ {
+ appendPQExpBuffer(dbQry, "SELECT tableoid, oid, datname, "
+ "(%s datdba) AS dba, "
+ "pg_encoding_to_char(encoding) AS encoding, "
+ "datcollate, datctype, datfrozenxid, datminmxid, "
+ "(SELECT array_agg(acl ORDER BY row_n) FROM "
+ " (SELECT acl, row_n FROM "
+ " unnest(coalesce(datacl,acldefault('d',datdba))) "
+ " WITH ORDINALITY AS perm(acl,row_n) "
+ " WHERE NOT EXISTS ( "
+ " SELECT 1 "
+ " FROM unnest(acldefault('d',datdba)) "
+ " AS init(init_acl) "
+ " WHERE acl = init_acl)) AS datacls) "
+ " AS datacl, "
+ "(SELECT array_agg(acl ORDER BY row_n) FROM "
+ " (SELECT acl, row_n FROM "
+ " unnest(acldefault('d',datdba)) "
+ " WITH ORDINALITY AS initp(acl,row_n) "
+ " WHERE NOT EXISTS ( "
+ " SELECT 1 "
+ " FROM unnest(coalesce(datacl,acldefault('d',datdba))) "
+ " AS permp(orig_acl) "
+ " WHERE acl = orig_acl)) AS rdatacls) "
+ " AS rdatacl, "
+ "datistemplate, datconnlimit, false as dathaslogontriggers, "
"(SELECT spcname FROM pg_tablespace t WHERE t.oid = dattablespace) AS tablespace, "
"shobj_description(oid, 'pg_database') AS description "
@@ -2796,7 +2832,7 @@ dumpDatabase(Archive *fout)
"(%s datdba) AS dba, "
"pg_encoding_to_char(encoding) AS encoding, "
"datcollate, datctype, datfrozenxid, datminmxid, "
- "datacl, '' as rdatacl, datistemplate, datconnlimit, "
+ "datacl, '' as rdatacl, datistemplate, datconnlimit, dathaslogontriggers"
"(SELECT spcname FROM pg_tablespace t WHERE t.oid = dattablespace) AS tablespace, "
"shobj_description(oid, 'pg_database') AS description "
@@ -2810,7 +2846,7 @@ dumpDatabase(Archive *fout)
"(%s datdba) AS dba, "
"pg_encoding_to_char(encoding) AS encoding, "
"datcollate, datctype, datfrozenxid, 0 AS datminmxid, "
- "datacl, '' as rdatacl, datistemplate, datconnlimit, "
+ "datacl, '' as rdatacl, datistemplate, datconnlimit, false as dathaslogontriggers, "
"(SELECT spcname FROM pg_tablespace t WHERE t.oid = dattablespace) AS tablespace, "
"shobj_description(oid, 'pg_database') AS description "
@@ -2824,7 +2860,7 @@ dumpDatabase(Archive *fout)
"(%s datdba) AS dba, "
"pg_encoding_to_char(encoding) AS encoding, "
"NULL AS datcollate, NULL AS datctype, datfrozenxid, 0 AS datminmxid, "
- "datacl, '' as rdatacl, datistemplate, datconnlimit, "
+ "datacl, '' as rdatacl, datistemplate, datconnlimit, false as dathaslogontriggers, "
"(SELECT spcname FROM pg_tablespace t WHERE t.oid = dattablespace) AS tablespace, "
"shobj_description(oid, 'pg_database') AS description "
@@ -2839,7 +2875,7 @@ dumpDatabase(Archive *fout)
"pg_encoding_to_char(encoding) AS encoding, "
"NULL AS datcollate, NULL AS datctype, datfrozenxid, 0 AS datminmxid, "
"datacl, '' as rdatacl, datistemplate, "
- "-1 as datconnlimit, "
+ "-1 as datconnlimit, false as dathaslogontriggers, "
"(SELECT spcname FROM pg_tablespace t WHERE t.oid = dattablespace) AS tablespace "
"FROM pg_database "
"WHERE datname = current_database()",
@@ -2861,6 +2897,7 @@ dumpDatabase(Archive *fout)
i_rdatacl = PQfnumber(res, "rdatacl");
i_datistemplate = PQfnumber(res, "datistemplate");
i_datconnlimit = PQfnumber(res, "datconnlimit");
+ i_dathaslogontriggers = PQfnumber(res, "dathaslogontriggers");
i_tablespace = PQfnumber(res, "tablespace");
dbCatId.tableoid = atooid(PQgetvalue(res, 0, i_tableoid));
@@ -2875,6 +2912,7 @@ dumpDatabase(Archive *fout)
datacl = PQgetvalue(res, 0, i_datacl);
rdatacl = PQgetvalue(res, 0, i_rdatacl);
datistemplate = PQgetvalue(res, 0, i_datistemplate);
+ dathaslogontriggers = PQgetvalue(res, 0, i_dathaslogontriggers);
datconnlimit = PQgetvalue(res, 0, i_datconnlimit);
tablespace = PQgetvalue(res, 0, i_tablespace);
@@ -3048,6 +3086,14 @@ dumpDatabase(Archive *fout)
appendPQExpBufferStr(delQry, ";\n");
}
+ if (strcmp(dathaslogontriggers, "t") == 0)
+ {
+ appendPQExpBufferStr(creaQry, "UPDATE pg_catalog.pg_database "
+ "SET dathaslogontriggers = true WHERE datname = ");
+ appendStringLiteralAH(creaQry, datname, fout);
+ appendPQExpBufferStr(creaQry, ";\n");
+ }
+
/* Add database-specific SET options */
dumpDatabaseConfig(fout, creaQry, datname, dbCatId.oid);
diff --git a/src/include/catalog/pg_database.dat b/src/include/catalog/pg_database.dat
index 21cd660..4c10575 100644
--- a/src/include/catalog/pg_database.dat
+++ b/src/include/catalog/pg_database.dat
@@ -15,7 +15,7 @@
{ oid => '1', oid_symbol => 'TemplateDbOid',
descr => 'default template for new databases',
datname => 'template1', encoding => 'ENCODING', datcollate => 'LC_COLLATE',
- datctype => 'LC_CTYPE', datistemplate => 't', datallowconn => 't',
+ datctype => 'LC_CTYPE', datistemplate => 't', dathaslogontriggers => 'f', datallowconn => 't',
datconnlimit => '-1', datlastsysoid => '0', datfrozenxid => '0',
datminmxid => '1', dattablespace => 'pg_default', datacl => '_null_' },
diff --git a/src/include/catalog/pg_database.h b/src/include/catalog/pg_database.h
index 47bcf40..7dc15a5 100644
--- a/src/include/catalog/pg_database.h
+++ b/src/include/catalog/pg_database.h
@@ -52,6 +52,9 @@ CATALOG(pg_database,1262,DatabaseRelationId) BKI_SHARED_RELATION BKI_ROWTYPE_OID
/* new connections allowed? */
bool datallowconn;
+ /* database has on-login triggers */
+ bool dathaslogontriggers;
+
/* max connections allowed (-1=no limit) */
int32 datconnlimit;
diff --git a/src/include/commands/event_trigger.h b/src/include/commands/event_trigger.h
index 407fd6a..47d481e 100644
--- a/src/include/commands/event_trigger.h
+++ b/src/include/commands/event_trigger.h
@@ -21,6 +21,8 @@
#include "tcop/deparse_utility.h"
#include "utils/aclchk_internal.h"
+extern bool enable_client_connection_trigger; /* GUC */
+
typedef struct EventTriggerData
{
NodeTag type;
@@ -53,6 +55,7 @@ extern void EventTriggerDDLCommandStart(Node *parsetree);
extern void EventTriggerDDLCommandEnd(Node *parsetree);
extern void EventTriggerSQLDrop(Node *parsetree);
extern void EventTriggerTableRewrite(Node *parsetree, Oid tableOid, int reason);
+extern void EventTriggerOnConnect(void);
extern bool EventTriggerBeginCompleteQuery(void);
extern void EventTriggerEndCompleteQuery(void);
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index be94852..988aa39 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -80,6 +80,7 @@ PG_CMDTAG(CMDTAG_CLUSTER, "CLUSTER", false, false, false)
PG_CMDTAG(CMDTAG_COMMENT, "COMMENT", true, false, false)
PG_CMDTAG(CMDTAG_COMMIT, "COMMIT", false, false, false)
PG_CMDTAG(CMDTAG_COMMIT_PREPARED, "COMMIT PREPARED", false, false, false)
+PG_CMDTAG(CMDTAG_CONNECT, "CONNECT", true, false, false)
PG_CMDTAG(CMDTAG_COPY, "COPY", false, false, true)
PG_CMDTAG(CMDTAG_COPY_FROM, "COPY FROM", false, false, false)
PG_CMDTAG(CMDTAG_CREATE_ACCESS_METHOD, "CREATE ACCESS METHOD", true, false, false)
diff --git a/src/include/tcop/tcopprot.h b/src/include/tcop/tcopprot.h
index bd30607..90376b2 100644
--- a/src/include/tcop/tcopprot.h
+++ b/src/include/tcop/tcopprot.h
@@ -30,6 +30,11 @@ extern PGDLLIMPORT const char *debug_query_string;
extern int max_stack_depth;
extern int PostAuthDelay;
+/* Hook for plugins to get control at start and end of session */
+typedef void (*client_connection_hook_type) (void);
+
+extern PGDLLIMPORT client_connection_hook_type client_connection_hook;
+
/* GUC-configurable parameters */
typedef enum
diff --git a/src/include/utils/evtcache.h b/src/include/utils/evtcache.h
index bb1e39e..ab7e8c3 100644
--- a/src/include/utils/evtcache.h
+++ b/src/include/utils/evtcache.h
@@ -22,7 +22,8 @@ typedef enum
EVT_DDLCommandStart,
EVT_DDLCommandEnd,
EVT_SQLDrop,
- EVT_TableRewrite
+ EVT_TableRewrite,
+ EVT_Connect,
} EventTriggerEvent;
typedef struct
diff --git a/src/test/recovery/t/000_client_connection_trigger.pl b/src/test/recovery/t/000_client_connection_trigger.pl
new file mode 100644
index 0000000..3dcd475
--- /dev/null
+++ b/src/test/recovery/t/000_client_connection_trigger.pl
@@ -0,0 +1,69 @@
+use strict;
+use warnings;
+use PostgresNode;
+use TestLib;
+use Test::More;
+if (!$use_unix_sockets)
+{
+ plan skip_all =>
+ "authentication tests cannot run without Unix-domain sockets";
+}
+else
+{
+ plan tests => 5;
+}
+
+# Initialize master node
+my $node = get_new_node('master');
+$node->init;
+$node->start;
+$node->safe_psql('postgres', q{
+CREATE ROLE regress_user LOGIN PASSWORD 'pass';
+CREATE ROLE regress_hacker LOGIN PASSWORD 'pass';
+
+CREATE TABLE connects(id serial, who text);
+
+CREATE FUNCTION on_login_proc() RETURNS EVENT_TRIGGER AS $$
+BEGIN
+ IF NOT pg_is_in_recovery() THEN
+ INSERT INTO connects (who) VALUES (session_user);
+ END IF;
+ IF session_user = 'regress_hacker' THEN
+ RAISE EXCEPTION 'You are not welcome!';
+ END IF;
+ RAISE NOTICE 'You are welcome!';
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+CREATE EVENT TRIGGER on_login_trigger ON client_connection EXECUTE FUNCTION on_login_proc();
+ALTER EVENT TRIGGER on_login_trigger ENABLE ALWAYS;
+}
+);
+my $res;
+
+$res = $node->safe_psql('postgres', "SELECT 1");
+
+$res = $node->safe_psql('postgres', "SELECT 1",
+ extra_params => [ '-U', 'regress_user', '-w' ]);
+
+my ($ret, $stdout, $stderr) = $node->psql('postgres', "SELECT 1",
+ extra_params => [ '-U', 'regress_hacker', '-w' ]);
+ok( $ret != 0 && $stderr =~ /You are not welcome!/ );
+
+$res = $node->safe_psql('postgres', "SELECT COUNT(1) FROM connects WHERE who = 'regress_user'");
+ok($res == 1);
+
+my $tempdir = TestLib::tempdir;
+command_ok(
+ [ "pg_dumpall", '-p', $node->port, '-c', "--file=$tempdir/regression_dump.sql", ],
+ "dumpall");
+# my $dump_contents = slurp_file("$tempdir/regression_dump.sql");
+# print($dump_contents);
+
+my $node1 = get_new_node('secondary');
+$node1->init;
+$node1->start;
+command_ok(["psql", '-p', $node1->port, '-b', '-f', "$tempdir/regression_dump.sql" ] );
+$res = $node1->safe_psql('postgres', "SELECT 1", extra_params => [ '-U', 'regress_user', '-w' ]);
+$res = $node1->safe_psql('postgres', "SELECT COUNT(1) FROM connects WHERE who = 'regress_user'");
+ok($res == 2);
diff --git a/src/test/recovery/t/001_stream_rep.pl b/src/test/recovery/t/001_stream_rep.pl
index 9e31a53..b4a21fb 100644
--- a/src/test/recovery/t/001_stream_rep.pl
+++ b/src/test/recovery/t/001_stream_rep.pl
@@ -43,6 +43,27 @@ $node_standby_2->start;
$node_primary->safe_psql('postgres',
"CREATE TABLE tab_int AS SELECT generate_series(1,1002) AS a");
+$node_primary->safe_psql('postgres', q{
+CREATE ROLE regress_user LOGIN PASSWORD 'pass';
+
+CREATE TABLE connects(id serial, who text);
+
+CREATE FUNCTION on_login_proc() RETURNS EVENT_TRIGGER AS $$
+BEGIN
+ IF NOT pg_is_in_recovery() THEN
+ INSERT INTO connects (who) VALUES (session_user);
+ END IF;
+ IF session_user = 'regress_hacker' THEN
+ RAISE EXCEPTION 'You are not welcome!';
+ END IF;
+ RAISE NOTICE 'You are welcome!';
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+CREATE EVENT TRIGGER on_login_trigger ON client_connection EXECUTE FUNCTION on_login_proc();
+ALTER EVENT TRIGGER on_login_trigger ENABLE ALWAYS;
+});
+
# Wait for standbys to catch up
$node_primary->wait_for_catchup($node_standby_1, 'replay',
$node_primary->lsn('insert'));
@@ -266,6 +287,9 @@ sub replay_check
replay_check();
+$node_standby_1->safe_psql('postgres', "SELECT 1", extra_params => [ '-U', 'regress_user', '-w' ]);
+$node_standby_2->safe_psql('postgres', "SELECT 2", extra_params => [ '-U', 'regress_user', '-w' ]);
+
note "enabling hot_standby_feedback";
# Enable hs_feedback. The slot should gain an xmin. We set the status interval
diff --git a/src/test/regress/expected/event_trigger.out b/src/test/regress/expected/event_trigger.out
index bdd0ffc..3ecbd6a 100644
--- a/src/test/regress/expected/event_trigger.out
+++ b/src/test/regress/expected/event_trigger.out
@@ -536,3 +536,40 @@ NOTICE: DROP POLICY - ddl_command_end
DROP EVENT TRIGGER start_rls_command;
DROP EVENT TRIGGER end_rls_command;
DROP EVENT TRIGGER sql_drop_command;
+-- On session start triggers
+create table connects(id serial, who text);
+create function on_login_proc() returns event_trigger as $$
+begin
+ insert into connects (who) values ('I am');
+ raise notice 'You are welcome!';
+end;
+$$ language plpgsql;
+create event trigger on_login_trigger on client_connection execute procedure on_login_proc();
+alter event trigger on_login_trigger enable always;
+\c
+NOTICE: You are welcome!
+select * from connects;
+ id | who
+----+------
+ 1 | I am
+(1 row)
+
+\c
+NOTICE: You are welcome!
+select * from connects;
+ id | who
+----+------
+ 1 | I am
+ 2 | I am
+(2 rows)
+
+-- Test handing exeptions in client_connection trigger
+drop table connects;
+-- superuser should ignore error
+\c
+NOTICE: client_connection trigger failed with message: relation "connects" does not exist
+-- suppress trigger firing
+\c "dbname=regression options='-c disable_client_connection_trigger=true'"
+-- Cleanup
+drop event trigger on_login_trigger;
+drop function on_login_proc();
diff --git a/src/test/regress/sql/event_trigger.sql b/src/test/regress/sql/event_trigger.sql
index 18b2a26..a1c5cf2 100644
--- a/src/test/regress/sql/event_trigger.sql
+++ b/src/test/regress/sql/event_trigger.sql
@@ -429,3 +429,31 @@ DROP POLICY p2 ON event_trigger_test;
DROP EVENT TRIGGER start_rls_command;
DROP EVENT TRIGGER end_rls_command;
DROP EVENT TRIGGER sql_drop_command;
+
+-- On session start triggers
+create table connects(id serial, who text);
+create function on_login_proc() returns event_trigger as $$
+begin
+ insert into connects (who) values ('I am');
+ raise notice 'You are welcome!';
+end;
+$$ language plpgsql;
+create event trigger on_login_trigger on client_connection execute procedure on_login_proc();
+alter event trigger on_login_trigger enable always;
+\c
+select * from connects;
+\c
+select * from connects;
+
+-- Test handing exeptions in client_connection trigger
+
+drop table connects;
+-- superuser should ignore error
+\c
+-- suppress trigger firing
+\c "dbname=regression options='-c disable_client_connection_trigger=true'"
+
+
+-- Cleanup
+drop event trigger on_login_trigger;
+drop function on_login_proc();
