7 files changed, 163 insertions, 24 deletions

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index df0cd775588..bc93101ff71 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -76,6 +76,7 @@
 #define PARALLEL_KEY_REINDEX_STATE			UINT64CONST(0xFFFFFFFFFFFF000C)
 #define PARALLEL_KEY_RELMAPPER_STATE		UINT64CONST(0xFFFFFFFFFFFF000D)
 #define PARALLEL_KEY_UNCOMMITTEDENUMS		UINT64CONST(0xFFFFFFFFFFFF000E)
+#define PARALLEL_KEY_CLIENTCONNINFO			UINT64CONST(0xFFFFFFFFFFFF000F)
 
 /* Fixed-size parallel state. */
 typedef struct FixedParallelState
@@ -212,6 +213,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	Size		reindexlen = 0;
 	Size		relmapperlen = 0;
 	Size		uncommittedenumslen = 0;
+	Size		clientconninfolen = 0;
 	Size		segsize = 0;
 	int			i;
 	FixedParallelState *fps;
@@ -272,8 +274,10 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_estimate_chunk(&pcxt->estimator, relmapperlen);
 		uncommittedenumslen = EstimateUncommittedEnumsSpace();
 		shm_toc_estimate_chunk(&pcxt->estimator, uncommittedenumslen);
+		clientconninfolen = EstimateClientConnectionInfoSpace();
+		shm_toc_estimate_chunk(&pcxt->estimator, clientconninfolen);
 		/* If you add more chunks here, you probably need to add keys. */
-		shm_toc_estimate_keys(&pcxt->estimator, 11);
+		shm_toc_estimate_keys(&pcxt->estimator, 12);
 
 		/* Estimate space need for error queues. */
 		StaticAssertStmt(BUFFERALIGN(PARALLEL_ERROR_QUEUE_SIZE) ==
@@ -352,6 +356,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		char	   *session_dsm_handle_space;
 		char	   *entrypointstate;
 		char	   *uncommittedenumsspace;
+		char	   *clientconninfospace;
 		Size		lnamelen;
 
 		/* Serialize shared libraries we have loaded. */
@@ -422,6 +427,12 @@ InitializeParallelDSM(ParallelContext *pcxt)
 		shm_toc_insert(pcxt->toc, PARALLEL_KEY_UNCOMMITTEDENUMS,
 					   uncommittedenumsspace);
 
+		/* Serialize our ClientConnectionInfo. */
+		clientconninfospace = shm_toc_allocate(pcxt->toc, clientconninfolen);
+		SerializeClientConnectionInfo(clientconninfolen, clientconninfospace);
+		shm_toc_insert(pcxt->toc, PARALLEL_KEY_CLIENTCONNINFO,
+					   clientconninfospace);
+
 		/* Allocate space for worker information. */
 		pcxt->worker = palloc0(sizeof(ParallelWorkerInfo) * pcxt->nworkers);
 
@@ -1270,6 +1281,7 @@ ParallelWorkerMain(Datum main_arg)
 	char	   *reindexspace;
 	char	   *relmapperspace;
 	char	   *uncommittedenumsspace;
+	char	   *clientconninfospace;
 	StringInfoData msgbuf;
 	char	   *session_dsm_handle_space;
 	Snapshot	tsnapshot;
@@ -1479,6 +1491,11 @@ ParallelWorkerMain(Datum main_arg)
 										   false);
 	RestoreUncommittedEnums(uncommittedenumsspace);
 
+	/* Restore the ClientConnectionInfo. */
+	clientconninfospace = shm_toc_lookup(toc, PARALLEL_KEY_CLIENTCONNINFO,
+										 false);
+	RestoreClientConnectionInfo(clientconninfospace);
+
 	/* Attach to the leader's serializable transaction, if SERIALIZABLE. */
 	AttachSerializableXact(fps->serializable_xact_handle);
 
diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index 1545ff9f161..2e7330f7bc6 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -333,23 +333,23 @@ auth_failed(Port *port, int status, const char *logdetail)
 
 /*
  * Sets the authenticated identity for the current user.  The provided string
- * will be copied into the TopMemoryContext.  The ID will be logged if
- * log_connections is enabled.
+ * will be stored into MyClientConnectionInfo, alongside the current HBA
+ * method in use.  The ID will be logged if log_connections is enabled.
  *
  * Auth methods should call this routine exactly once, as soon as the user is
  * successfully authenticated, even if they have reasons to know that
  * authorization will fail later.
  *
  * The provided string will be copied into TopMemoryContext, to match the
- * lifetime of the Port, so it is safe to pass a string that is managed by an
- * external library.
+ * lifetime of MyClientConnectionInfo, so it is safe to pass a string that is
+ * managed by an external library.
  */
 static void
 set_authn_id(Port *port, const char *id)
 {
 	Assert(id);
 
-	if (port->authn_id)
+	if (MyClientConnectionInfo.authn_id)
 	{
 		/*
 		 * An existing authn_id should never be overwritten; that means two
@@ -360,18 +360,20 @@ set_authn_id(Port *port, const char *id)
 		ereport(FATAL,
 				(errmsg("authentication identifier set more than once"),
 				 errdetail_log("previous identifier: \"%s\"; new identifier: \"%s\"",
-							   port->authn_id, id)));
+							   MyClientConnectionInfo.authn_id, id)));
 	}
 
-	port->authn_id = MemoryContextStrdup(TopMemoryContext, id);
+	MyClientConnectionInfo.authn_id = MemoryContextStrdup(TopMemoryContext, id);
+	MyClientConnectionInfo.auth_method = port->hba->auth_method;
 
 	if (Log_connections)
 	{
 		ereport(LOG,
 				errmsg("connection authenticated: identity=\"%s\" method=%s "
 					   "(%s:%d)",
-					   port->authn_id, hba_authname(port->hba->auth_method), HbaFileName,
-					   port->hba->linenumber));
+					   MyClientConnectionInfo.authn_id,
+					   hba_authname(MyClientConnectionInfo.auth_method),
+					   HbaFileName, port->hba->linenumber));
 	}
 }
 
@@ -1907,7 +1909,8 @@ auth_peer(hbaPort *port)
 	 */
 	set_authn_id(port, pw->pw_name);
 
-	ret = check_usermap(port->hba->usermap, port->user_name, port->authn_id, false);
+	ret = check_usermap(port->hba->usermap, port->user_name,
+						MyClientConnectionInfo.authn_id, false);
 
 	return ret;
 #else
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 1664fcee2a7..53f02241632 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -4305,6 +4305,7 @@ BackendInitialize(Port *port)
 
 	/* Save port etc. for ps status */
 	MyProcPort = port;
+	memset(&MyClientConnectionInfo, 0, sizeof(MyClientConnectionInfo));
 
 	/* Tell fd.c about the long-lived FD associated with the port */
 	ReserveExternalFD();
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index bf3871a774b..683f616b1a8 100644
--- a/src/backend/utils/init/miscinit.c
+++ b/src/backend/utils/init/miscinit.c
@@ -936,6 +936,99 @@ GetUserNameFromId(Oid roleid, bool noerr)
 	return result;
 }
 
+/* ------------------------------------------------------------------------
+ *				Client connection state shared with parallel workers
+ *
+ * ClientConnectionInfo contains pieces of information about the client that
+ * need to be synced to parallel workers when they initialize.
+ *-------------------------------------------------------------------------
+ */
+
+ClientConnectionInfo MyClientConnectionInfo;
+
+/*
+ * Intermediate representation of ClientConnectionInfo for easier
+ * serialization.  Variable-length fields are allocated right after this
+ * header.
+ */
+typedef struct SerializedClientConnectionInfo
+{
+	int32		authn_id_len;	/* strlen(authn_id), or -1 if NULL */
+	UserAuth	auth_method;
+} SerializedClientConnectionInfo;
+
+/*
+ * Calculate the space needed to serialize MyClientConnectionInfo.
+ */
+Size
+EstimateClientConnectionInfoSpace(void)
+{
+	Size		size = 0;
+
+	size = add_size(size, sizeof(SerializedClientConnectionInfo));
+
+	if (MyClientConnectionInfo.authn_id)
+		size = add_size(size, strlen(MyClientConnectionInfo.authn_id) + 1);
+
+	return size;
+}
+
+/*
+ * Serialize MyClientConnectionInfo for use by parallel workers.
+ */
+void
+SerializeClientConnectionInfo(Size maxsize, char *start_address)
+{
+	SerializedClientConnectionInfo serialized = {0};
+
+	serialized.authn_id_len = -1;
+	serialized.auth_method = MyClientConnectionInfo.auth_method;
+
+	if (MyClientConnectionInfo.authn_id)
+		serialized.authn_id_len = strlen(MyClientConnectionInfo.authn_id);
+
+	/* Copy serialized representation to buffer */
+	Assert(maxsize >= sizeof(serialized));
+	memcpy(start_address, &serialized, sizeof(serialized));
+
+	maxsize -= sizeof(serialized);
+	start_address += sizeof(serialized);
+
+	/* Copy authn_id into the space after the struct */
+	if (serialized.authn_id_len >= 0)
+	{
+		Assert(maxsize >= (serialized.authn_id_len + 1));
+		memcpy(start_address,
+			   MyClientConnectionInfo.authn_id,
+		/* include the NULL terminator to ease deserialization */
+			   serialized.authn_id_len + 1);
+	}
+}
+
+/*
+ * Restore MyClientConnectionInfo from its serialized representation.
+ */
+void
+RestoreClientConnectionInfo(char *conninfo)
+{
+	SerializedClientConnectionInfo serialized;
+
+	memcpy(&serialized, conninfo, sizeof(serialized));
+
+	/* Copy the fields back into place */
+	MyClientConnectionInfo.authn_id = NULL;
+	MyClientConnectionInfo.auth_method = serialized.auth_method;
+
+	if (serialized.authn_id_len >= 0)
+	{
+		char	   *authn_id;
+
+		authn_id = conninfo + sizeof(serialized);
+		MyClientConnectionInfo.authn_id = MemoryContextStrdup(TopMemoryContext,
+															  authn_id);
+	}
+}
+
 
 /*-------------------------------------------------------------------------
  *				Interlock-file support
diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index 32d3a4b0853..6d452ec6d95 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -89,6 +89,37 @@ typedef struct
 #endif
 
 /*
+ * ClientConnectionInfo includes the fields describing the client connection
+ * that are copied over to parallel workers as nothing from Port does that.
+ * The same rules apply for allocations here as for Port (everything must be
+ * malloc'd or palloc'd in TopMemoryContext).
+ *
+ * If you add a struct member here, remember to also handle serialization in
+ * SerializeClientConnectionInfo() and co.
+ */
+typedef struct ClientConnectionInfo
+{
+	/*
+	 * Authenticated identity.  The meaning of this identifier is dependent on
+	 * auth_method; it is the identity (if any) that the user presented during
+	 * the authentication cycle, before they were assigned a database role.
+	 * (It is effectively the "SYSTEM-USERNAME" of a pg_ident usermap --
+	 * though the exact string in use may be different, depending on pg_hba
+	 * options.)
+	 *
+	 * authn_id is NULL if the user has not actually been authenticated, for
+	 * example if the "trust" auth method is in use.
+	 */
+	const char *authn_id;
+
+	/*
+	 * The HBA method that determined the above authn_id.  This only has
+	 * meaning if authn_id is not NULL; otherwise it's undefined.
+	 */
+	UserAuth	auth_method;
+} ClientConnectionInfo;
+
+/*
  * This is used by the postmaster in its communication with frontends.  It
  * contains all state information needed during this communication before the
  * backend is run.  The Port structure is kept in malloc'd memory and is
@@ -149,19 +180,6 @@ typedef struct Port
 	HbaLine    *hba;
 
 	/*
-	 * Authenticated identity.  The meaning of this identifier is dependent on
-	 * hba->auth_method; it is the identity (if any) that the user presented
-	 * during the authentication cycle, before they were assigned a database
-	 * role.  (It is effectively the "SYSTEM-USERNAME" of a pg_ident usermap
-	 * -- though the exact string in use may be different, depending on pg_hba
-	 * options.)
-	 *
-	 * authn_id is NULL if the user has not actually been authenticated, for
-	 * example if the "trust" auth method is in use.
-	 */
-	const char *authn_id;
-
-	/*
 	 * TCP keepalive and user timeout settings.
 	 *
 	 * default values are 0 if AF_UNIX or not yet known; current values are 0
@@ -317,6 +335,7 @@ extern ssize_t be_gssapi_write(Port *port, void *ptr, size_t len);
 #endif							/* ENABLE_GSS */
 
 extern PGDLLIMPORT ProtocolVersion FrontendProtocol;
+extern PGDLLIMPORT ClientConnectionInfo MyClientConnectionInfo;
 
 /* TCP keepalives configuration. These are no-ops on an AF_UNIX socket. */
 
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 7c41b279942..65cf4ba50f3 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -482,6 +482,10 @@ extern bool has_rolreplication(Oid roleid);
 typedef void (*shmem_request_hook_type) (void);
 extern PGDLLIMPORT shmem_request_hook_type shmem_request_hook;
 
+extern Size EstimateClientConnectionInfoSpace(void);
+extern void SerializeClientConnectionInfo(Size maxsize, char *start_address);
+extern void RestoreClientConnectionInfo(char *conninfo);
+
 /* in executor/nodeHash.c */
 extern size_t get_hash_memory_limit(void);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 35c9f1efce2..a4a4e356e51 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -373,6 +373,7 @@ CkptTsStatus
 ClientAuthentication_hook_type
 ClientCertMode
 ClientCertName
+ClientConnectionInfo
 ClientData
 ClonePtrType
 ClosePortalStmt
@@ -2455,6 +2456,7 @@ SerCommitSeqNo
 SerialControl
 SerializableXactHandle
 SerializedActiveRelMaps
+SerializedClientConnectionInfo
 SerializedRanges
 SerializedReindexState
 SerializedSnapshotData