Adding upstream version 15.5.upstream/15.5

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 903 insertions, 0 deletions

diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
new file mode 100644
index 0000000..ac9042f
--- /dev/null
+++ b/src/interfaces/libpq/libpq-int.h
@@ -0,0 +1,903 @@
+/*-------------------------------------------------------------------------
+ *
+ * libpq-int.h
+ *	  This file contains internal definitions meant to be used only by
+ *	  the frontend libpq library, not by applications that call it.
+ *
+ *	  An application can include this file if it wants to bypass the
+ *	  official API defined by libpq-fe.h, but code that does so is much
+ *	  more likely to break across PostgreSQL releases than code that uses
+ *	  only the official API.
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/interfaces/libpq/libpq-int.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef LIBPQ_INT_H
+#define LIBPQ_INT_H
+
+/* We assume libpq-fe.h has already been included. */
+#include "libpq-events.h"
+
+#include <time.h>
+#ifndef WIN32
+#include <sys/time.h>
+#endif
+
+#ifdef ENABLE_THREAD_SAFETY
+#ifdef WIN32
+#include "pthread-win32.h"
+#else
+#include <pthread.h>
+#endif
+#include <signal.h>
+#endif
+
+/* include stuff common to fe and be */
+#include "getaddrinfo.h"
+#include "libpq/pqcomm.h"
+/* include stuff found in fe only */
+#include "fe-auth-sasl.h"
+#include "pqexpbuffer.h"
+
+#ifdef ENABLE_GSS
+#if defined(HAVE_GSSAPI_H)
+#include <gssapi.h>
+#else
+#include <gssapi/gssapi.h>
+#endif
+#endif
+
+#ifdef ENABLE_SSPI
+#define SECURITY_WIN32
+#if defined(WIN32) && !defined(_MSC_VER)
+#include <ntsecapi.h>
+#endif
+#include <security.h>
+#undef SECURITY_WIN32
+
+#ifndef ENABLE_GSS
+/*
+ * Define a fake structure compatible with GSSAPI on Unix.
+ */
+typedef struct
+{
+	void	   *value;
+	int			length;
+} gss_buffer_desc;
+#endif
+#endif							/* ENABLE_SSPI */
+
+#ifdef USE_OPENSSL
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+
+#ifndef OPENSSL_NO_ENGINE
+#define USE_SSL_ENGINE
+#endif
+#endif							/* USE_OPENSSL */
+
+/*
+ * POSTGRES backend dependent Constants.
+ */
+#define CMDSTATUS_LEN 64		/* should match COMPLETION_TAG_BUFSIZE */
+
+/*
+ * PGresult and the subsidiary types PGresAttDesc, PGresAttValue
+ * represent the result of a query (or more precisely, of a single SQL
+ * command --- a query string given to PQexec can contain multiple commands).
+ * Note we assume that a single command can return at most one tuple group,
+ * hence there is no need for multiple descriptor sets.
+ */
+
+/* Subsidiary-storage management structure for PGresult.
+ * See space management routines in fe-exec.c for details.
+ * Note that space[k] refers to the k'th byte starting from the physical
+ * head of the block --- it's a union, not a struct!
+ */
+typedef union pgresult_data PGresult_data;
+
+union pgresult_data
+{
+	PGresult_data *next;		/* link to next block, or NULL */
+	char		space[1];		/* dummy for accessing block as bytes */
+};
+
+/* Data about a single parameter of a prepared statement */
+typedef struct pgresParamDesc
+{
+	Oid			typid;			/* type id */
+} PGresParamDesc;
+
+/*
+ * Data for a single attribute of a single tuple
+ *
+ * We use char* for Attribute values.
+ *
+ * The value pointer always points to a null-terminated area; we add a
+ * null (zero) byte after whatever the backend sends us.  This is only
+ * particularly useful for text values ... with a binary value, the
+ * value might have embedded nulls, so the application can't use C string
+ * operators on it.  But we add a null anyway for consistency.
+ * Note that the value itself does not contain a length word.
+ *
+ * A NULL attribute is a special case in two ways: its len field is NULL_LEN
+ * and its value field points to null_field in the owning PGresult.  All the
+ * NULL attributes in a query result point to the same place (there's no need
+ * to store a null string separately for each one).
+ */
+
+#define NULL_LEN		(-1)	/* pg_result len for NULL value */
+
+typedef struct pgresAttValue
+{
+	int			len;			/* length in bytes of the value */
+	char	   *value;			/* actual value, plus terminating zero byte */
+} PGresAttValue;
+
+/* Typedef for message-field list entries */
+typedef struct pgMessageField
+{
+	struct pgMessageField *next;	/* list link */
+	char		code;			/* field code */
+	char		contents[FLEXIBLE_ARRAY_MEMBER];	/* value, nul-terminated */
+} PGMessageField;
+
+/* Fields needed for notice handling */
+typedef struct
+{
+	PQnoticeReceiver noticeRec; /* notice message receiver */
+	void	   *noticeRecArg;
+	PQnoticeProcessor noticeProc;	/* notice message processor */
+	void	   *noticeProcArg;
+} PGNoticeHooks;
+
+typedef struct PGEvent
+{
+	PGEventProc proc;			/* the function to call on events */
+	char	   *name;			/* used only for error messages */
+	void	   *passThrough;	/* pointer supplied at registration time */
+	void	   *data;			/* optional state (instance) data */
+	bool		resultInitialized;	/* T if RESULTCREATE/COPY succeeded */
+} PGEvent;
+
+struct pg_result
+{
+	int			ntups;
+	int			numAttributes;
+	PGresAttDesc *attDescs;
+	PGresAttValue **tuples;		/* each PGresult tuple is an array of
+								 * PGresAttValue's */
+	int			tupArrSize;		/* allocated size of tuples array */
+	int			numParameters;
+	PGresParamDesc *paramDescs;
+	ExecStatusType resultStatus;
+	char		cmdStatus[CMDSTATUS_LEN];	/* cmd status from the query */
+	int			binary;			/* binary tuple values if binary == 1,
+								 * otherwise text */
+
+	/*
+	 * These fields are copied from the originating PGconn, so that operations
+	 * on the PGresult don't have to reference the PGconn.
+	 */
+	PGNoticeHooks noticeHooks;
+	PGEvent    *events;
+	int			nEvents;
+	int			client_encoding;	/* encoding id */
+
+	/*
+	 * Error information (all NULL if not an error result).  errMsg is the
+	 * "overall" error message returned by PQresultErrorMessage.  If we have
+	 * per-field info then it is stored in a linked list.
+	 */
+	char	   *errMsg;			/* error message, or NULL if no error */
+	PGMessageField *errFields;	/* message broken into fields */
+	char	   *errQuery;		/* text of triggering query, if available */
+
+	/* All NULL attributes in the query result point to this null string */
+	char		null_field[1];
+
+	/*
+	 * Space management information.  Note that attDescs and error stuff, if
+	 * not null, point into allocated blocks.  But tuples points to a
+	 * separately malloc'd block, so that we can realloc it.
+	 */
+	PGresult_data *curBlock;	/* most recently allocated block */
+	int			curOffset;		/* start offset of free space in block */
+	int			spaceLeft;		/* number of free bytes remaining in block */
+
+	size_t		memorySize;		/* total space allocated for this PGresult */
+};
+
+/* PGAsyncStatusType defines the state of the query-execution state machine */
+typedef enum
+{
+	PGASYNC_IDLE,				/* nothing's happening, dude */
+	PGASYNC_BUSY,				/* query in progress */
+	PGASYNC_READY,				/* query done, waiting for client to fetch
+								 * result */
+	PGASYNC_READY_MORE,			/* query done, waiting for client to fetch
+								 * result, more results expected from this
+								 * query */
+	PGASYNC_COPY_IN,			/* Copy In data transfer in progress */
+	PGASYNC_COPY_OUT,			/* Copy Out data transfer in progress */
+	PGASYNC_COPY_BOTH,			/* Copy In/Out data transfer in progress */
+	PGASYNC_PIPELINE_IDLE,		/* "Idle" between commands in pipeline mode */
+} PGAsyncStatusType;
+
+/* Target server type (decoded value of target_session_attrs) */
+typedef enum
+{
+	SERVER_TYPE_ANY = 0,		/* Any server (default) */
+	SERVER_TYPE_READ_WRITE,		/* Read-write server */
+	SERVER_TYPE_READ_ONLY,		/* Read-only server */
+	SERVER_TYPE_PRIMARY,		/* Primary server */
+	SERVER_TYPE_STANDBY,		/* Standby server */
+	SERVER_TYPE_PREFER_STANDBY, /* Prefer standby server */
+	SERVER_TYPE_PREFER_STANDBY_PASS2	/* second pass - behaves same as ANY */
+} PGTargetServerType;
+
+/* Boolean value plus a not-known state, for GUCs we might have to fetch */
+typedef enum
+{
+	PG_BOOL_UNKNOWN = 0,		/* Currently unknown */
+	PG_BOOL_YES,				/* Yes (true) */
+	PG_BOOL_NO					/* No (false) */
+} PGTernaryBool;
+
+/* Typedef for the EnvironmentOptions[] array */
+typedef struct PQEnvironmentOption
+{
+	const char *envName,		/* name of an environment variable */
+			   *pgName;			/* name of corresponding SET variable */
+} PQEnvironmentOption;
+
+/* Typedef for parameter-status list entries */
+typedef struct pgParameterStatus
+{
+	struct pgParameterStatus *next; /* list link */
+	char	   *name;			/* parameter name */
+	char	   *value;			/* parameter value */
+	/* Note: name and value are stored in same malloc block as struct is */
+} pgParameterStatus;
+
+/* large-object-access data ... allocated only if large-object code is used. */
+typedef struct pgLobjfuncs
+{
+	Oid			fn_lo_open;		/* OID of backend function lo_open		*/
+	Oid			fn_lo_close;	/* OID of backend function lo_close		*/
+	Oid			fn_lo_creat;	/* OID of backend function lo_creat		*/
+	Oid			fn_lo_create;	/* OID of backend function lo_create	*/
+	Oid			fn_lo_unlink;	/* OID of backend function lo_unlink	*/
+	Oid			fn_lo_lseek;	/* OID of backend function lo_lseek		*/
+	Oid			fn_lo_lseek64;	/* OID of backend function lo_lseek64	*/
+	Oid			fn_lo_tell;		/* OID of backend function lo_tell		*/
+	Oid			fn_lo_tell64;	/* OID of backend function lo_tell64	*/
+	Oid			fn_lo_truncate; /* OID of backend function lo_truncate	*/
+	Oid			fn_lo_truncate64;	/* OID of function lo_truncate64 */
+	Oid			fn_lo_read;		/* OID of backend function LOread		*/
+	Oid			fn_lo_write;	/* OID of backend function LOwrite		*/
+} PGlobjfuncs;
+
+/* PGdataValue represents a data field value being passed to a row processor.
+ * It could be either text or binary data; text data is not zero-terminated.
+ * A SQL NULL is represented by len < 0; then value is still valid but there
+ * are no data bytes there.
+ */
+typedef struct pgDataValue
+{
+	int			len;			/* data length in bytes, or <0 if NULL */
+	const char *value;			/* data value, without zero-termination */
+} PGdataValue;
+
+/* Host address type enum for struct pg_conn_host */
+typedef enum pg_conn_host_type
+{
+	CHT_HOST_NAME,
+	CHT_HOST_ADDRESS,
+	CHT_UNIX_SOCKET
+} pg_conn_host_type;
+
+/*
+ * PGQueryClass tracks which query protocol is in use for each command queue
+ * entry, or special operation in execution
+ */
+typedef enum
+{
+	PGQUERY_SIMPLE,				/* simple Query protocol (PQexec) */
+	PGQUERY_EXTENDED,			/* full Extended protocol (PQexecParams) */
+	PGQUERY_PREPARE,			/* Parse only (PQprepare) */
+	PGQUERY_DESCRIBE,			/* Describe Statement or Portal */
+	PGQUERY_SYNC,				/* Sync (at end of a pipeline) */
+	PGQUERY_CLOSE
+} PGQueryClass;
+
+/*
+ * An entry in the pending command queue.
+ */
+typedef struct PGcmdQueueEntry
+{
+	PGQueryClass queryclass;	/* Query type */
+	char	   *query;			/* SQL command, or NULL if none/unknown/OOM */
+	struct PGcmdQueueEntry *next;	/* list link */
+} PGcmdQueueEntry;
+
+/*
+ * pg_conn_host stores all information about each of possibly several hosts
+ * mentioned in the connection string.  Most fields are derived by splitting
+ * the relevant connection parameter (e.g., pghost) at commas.
+ */
+typedef struct pg_conn_host
+{
+	pg_conn_host_type type;		/* type of host address */
+	char	   *host;			/* host name or socket path */
+	char	   *hostaddr;		/* host numeric IP address */
+	char	   *port;			/* port number (always provided) */
+	char	   *password;		/* password for this host, read from the
+								 * password file; NULL if not sought or not
+								 * found in password file. */
+} pg_conn_host;
+
+/*
+ * PGconn stores all the state data associated with a single connection
+ * to a backend.
+ */
+struct pg_conn
+{
+	/* Saved values of connection options */
+	char	   *pghost;			/* the machine on which the server is running,
+								 * or a path to a UNIX-domain socket, or a
+								 * comma-separated list of machines and/or
+								 * paths; if NULL, use DEFAULT_PGSOCKET_DIR */
+	char	   *pghostaddr;		/* the numeric IP address of the machine on
+								 * which the server is running, or a
+								 * comma-separated list of same.  Takes
+								 * precedence over pghost. */
+	char	   *pgport;			/* the server's communication port number, or
+								 * a comma-separated list of ports */
+	char	   *connect_timeout;	/* connection timeout (numeric string) */
+	char	   *pgtcp_user_timeout; /* tcp user timeout (numeric string) */
+	char	   *client_encoding_initial;	/* encoding to use */
+	char	   *pgoptions;		/* options to start the backend with */
+	char	   *appname;		/* application name */
+	char	   *fbappname;		/* fallback application name */
+	char	   *dbName;			/* database name */
+	char	   *replication;	/* connect as the replication standby? */
+	char	   *pguser;			/* Postgres username and password, if any */
+	char	   *pgpass;
+	char	   *pgpassfile;		/* path to a file containing password(s) */
+	char	   *channel_binding;	/* channel binding mode
+									 * (require,prefer,disable) */
+	char	   *keepalives;		/* use TCP keepalives? */
+	char	   *keepalives_idle;	/* time between TCP keepalives */
+	char	   *keepalives_interval;	/* time between TCP keepalive
+										 * retransmits */
+	char	   *keepalives_count;	/* maximum number of TCP keepalive
+									 * retransmits */
+	char	   *sslmode;		/* SSL mode (require,prefer,allow,disable) */
+	char	   *sslcompression; /* SSL compression (0 or 1) */
+	char	   *sslkey;			/* client key filename */
+	char	   *sslcert;		/* client certificate filename */
+	char	   *sslpassword;	/* client key file password */
+	char	   *sslrootcert;	/* root certificate filename */
+	char	   *sslcrl;			/* certificate revocation list filename */
+	char	   *sslcrldir;		/* certificate revocation list directory name */
+	char	   *sslsni;			/* use SSL SNI extension (0 or 1) */
+	char	   *requirepeer;	/* required peer credentials for local sockets */
+	char	   *gssencmode;		/* GSS mode (require,prefer,disable) */
+	char	   *krbsrvname;		/* Kerberos service name */
+	char	   *gsslib;			/* What GSS library to use ("gssapi" or
+								 * "sspi") */
+	char	   *ssl_min_protocol_version;	/* minimum TLS protocol version */
+	char	   *ssl_max_protocol_version;	/* maximum TLS protocol version */
+	char	   *target_session_attrs;	/* desired session properties */
+
+	/* Optional file to write trace info to */
+	FILE	   *Pfdebug;
+	int			traceFlags;
+
+	/* Callback procedures for notice message processing */
+	PGNoticeHooks noticeHooks;
+
+	/* Event procs registered via PQregisterEventProc */
+	PGEvent    *events;			/* expandable array of event data */
+	int			nEvents;		/* number of active events */
+	int			eventArraySize; /* allocated array size */
+
+	/* Status indicators */
+	ConnStatusType status;
+	PGAsyncStatusType asyncStatus;
+	PGTransactionStatusType xactStatus; /* never changes to ACTIVE */
+	char		last_sqlstate[6];	/* last reported SQLSTATE */
+	bool		options_valid;	/* true if OK to attempt connection */
+	bool		nonblocking;	/* whether this connection is using nonblock
+								 * sending semantics */
+	PGpipelineStatus pipelineStatus;	/* status of pipeline mode */
+	bool		singleRowMode;	/* return current query result row-by-row? */
+	char		copy_is_binary; /* 1 = copy binary, 0 = copy text */
+	int			copy_already_done;	/* # bytes already returned in COPY OUT */
+	PGnotify   *notifyHead;		/* oldest unreported Notify msg */
+	PGnotify   *notifyTail;		/* newest unreported Notify msg */
+
+	/* Support for multiple hosts in connection string */
+	int			nconnhost;		/* # of hosts named in conn string */
+	int			whichhost;		/* host we're currently trying/connected to */
+	pg_conn_host *connhost;		/* details about each named host */
+	char	   *connip;			/* IP address for current network connection */
+
+	/*
+	 * The pending command queue as a singly-linked list.  Head is the command
+	 * currently in execution, tail is where new commands are added.
+	 */
+	PGcmdQueueEntry *cmd_queue_head;
+	PGcmdQueueEntry *cmd_queue_tail;
+
+	/*
+	 * To save malloc traffic, we don't free entries right away; instead we
+	 * save them in this list for possible reuse.
+	 */
+	PGcmdQueueEntry *cmd_queue_recycle;
+
+	/* Connection data */
+	pgsocket	sock;			/* FD for socket, PGINVALID_SOCKET if
+								 * unconnected */
+	SockAddr	laddr;			/* Local address */
+	SockAddr	raddr;			/* Remote address */
+	ProtocolVersion pversion;	/* FE/BE protocol version in use */
+	int			sversion;		/* server version, e.g. 70401 for 7.4.1 */
+	bool		auth_req_received;	/* true if any type of auth req received */
+	bool		password_needed;	/* true if server demanded a password */
+	bool		sigpipe_so;		/* have we masked SIGPIPE via SO_NOSIGPIPE? */
+	bool		sigpipe_flag;	/* can we mask SIGPIPE via MSG_NOSIGNAL? */
+	bool		write_failed;	/* have we had a write failure on sock? */
+	char	   *write_err_msg;	/* write error message, or NULL if OOM */
+
+	/* Transient state needed while establishing connection */
+	PGTargetServerType target_server_type;	/* desired session properties */
+	bool		try_next_addr;	/* time to advance to next address/host? */
+	bool		try_next_host;	/* time to advance to next connhost[]? */
+	struct addrinfo *addrlist;	/* list of addresses for current connhost */
+	struct addrinfo *addr_cur;	/* the one currently being tried */
+	int			addrlist_family;	/* needed to know how to free addrlist */
+	bool		send_appname;	/* okay to send application_name? */
+
+	/* Miscellaneous stuff */
+	int			be_pid;			/* PID of backend --- needed for cancels */
+	int			be_key;			/* key of backend --- needed for cancels */
+	pgParameterStatus *pstatus; /* ParameterStatus data */
+	int			client_encoding;	/* encoding id */
+	bool		std_strings;	/* standard_conforming_strings */
+	PGTernaryBool default_transaction_read_only;	/* default_transaction_read_only */
+	PGTernaryBool in_hot_standby;	/* in_hot_standby */
+	PGVerbosity verbosity;		/* error/notice message verbosity */
+	PGContextVisibility show_context;	/* whether to show CONTEXT field */
+	PGlobjfuncs *lobjfuncs;		/* private state for large-object access fns */
+
+	/* Buffer for data received from backend and not yet processed */
+	char	   *inBuffer;		/* currently allocated buffer */
+	int			inBufSize;		/* allocated size of buffer */
+	int			inStart;		/* offset to first unconsumed data in buffer */
+	int			inCursor;		/* next byte to tentatively consume */
+	int			inEnd;			/* offset to first position after avail data */
+
+	/* Buffer for data not yet sent to backend */
+	char	   *outBuffer;		/* currently allocated buffer */
+	int			outBufSize;		/* allocated size of buffer */
+	int			outCount;		/* number of chars waiting in buffer */
+
+	/* State for constructing messages in outBuffer */
+	int			outMsgStart;	/* offset to msg start (length word); if -1,
+								 * msg has no length word */
+	int			outMsgEnd;		/* offset to msg end (so far) */
+
+	/* Row processor interface workspace */
+	PGdataValue *rowBuf;		/* array for passing values to rowProcessor */
+	int			rowBufLen;		/* number of entries allocated in rowBuf */
+
+	/*
+	 * Status for asynchronous result construction.  If result isn't NULL, it
+	 * is a result being constructed or ready to return.  If result is NULL
+	 * and error_result is true, then we need to return a PGRES_FATAL_ERROR
+	 * result, but haven't yet constructed it; text for the error has been
+	 * appended to conn->errorMessage.  (Delaying construction simplifies
+	 * dealing with out-of-memory cases.)  If next_result isn't NULL, it is a
+	 * PGresult that will replace "result" after we return that one.
+	 */
+	PGresult   *result;			/* result being constructed */
+	bool		error_result;	/* do we need to make an ERROR result? */
+	PGresult   *next_result;	/* next result (used in single-row mode) */
+
+	/* Assorted state for SASL, SSL, GSS, etc */
+	const pg_fe_sasl_mech *sasl;
+	void	   *sasl_state;
+
+	/* SSL structures */
+	bool		ssl_in_use;
+
+#ifdef USE_SSL
+	bool		allow_ssl_try;	/* Allowed to try SSL negotiation */
+	bool		wait_ssl_try;	/* Delay SSL negotiation until after
+								 * attempting normal connection */
+#ifdef USE_OPENSSL
+	SSL		   *ssl;			/* SSL status, if have SSL connection */
+	X509	   *peer;			/* X509 cert of server */
+#ifdef USE_SSL_ENGINE
+	ENGINE	   *engine;			/* SSL engine, if any */
+#else
+	void	   *engine;			/* dummy field to keep struct the same if
+								 * OpenSSL version changes */
+#endif
+	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
+								 * been done for this connection. This can be
+								 * removed once support for OpenSSL 1.0.2 is
+								 * removed as this locking is handled
+								 * internally in OpenSSL >= 1.1.0. */
+#endif							/* USE_OPENSSL */
+#endif							/* USE_SSL */
+
+#ifdef ENABLE_GSS
+	gss_ctx_id_t gctx;			/* GSS context */
+	gss_name_t	gtarg_nam;		/* GSS target name */
+
+	/* The following are encryption-only */
+	bool		try_gss;		/* GSS attempting permitted */
+	bool		gssenc;			/* GSS encryption is usable */
+	gss_cred_id_t gcred;		/* GSS credential temp storage. */
+
+	/* GSS encryption I/O state --- see fe-secure-gssapi.c */
+	char	   *gss_SendBuffer; /* Encrypted data waiting to be sent */
+	int			gss_SendLength; /* End of data available in gss_SendBuffer */
+	int			gss_SendNext;	/* Next index to send a byte from
+								 * gss_SendBuffer */
+	int			gss_SendConsumed;	/* Number of *unencrypted* bytes consumed
+									 * for current contents of gss_SendBuffer */
+	char	   *gss_RecvBuffer; /* Received, encrypted data */
+	int			gss_RecvLength; /* End of data available in gss_RecvBuffer */
+	char	   *gss_ResultBuffer;	/* Decryption of data in gss_RecvBuffer */
+	int			gss_ResultLength;	/* End of data available in
+									 * gss_ResultBuffer */
+	int			gss_ResultNext; /* Next index to read a byte from
+								 * gss_ResultBuffer */
+	uint32		gss_MaxPktSize; /* Maximum size we can encrypt and fit the
+								 * results into our output buffer */
+#endif
+
+#ifdef ENABLE_SSPI
+	CredHandle *sspicred;		/* SSPI credentials handle */
+	CtxtHandle *sspictx;		/* SSPI context */
+	char	   *sspitarget;		/* SSPI target name */
+	int			usesspi;		/* Indicate if SSPI is in use on the
+								 * connection */
+#endif
+
+	/*
+	 * Buffer for current error message.  This is cleared at the start of any
+	 * connection attempt or query cycle; after that, all code should append
+	 * messages to it, never overwrite.
+	 *
+	 * In some situations we might report an error more than once in a query
+	 * cycle.  If so, errorMessage accumulates text from all the errors, and
+	 * errorReported tracks how much we've already reported, so that the
+	 * individual error PGresult objects don't contain duplicative text.
+	 */
+	PQExpBufferData errorMessage;	/* expansible string */
+	int			errorReported;	/* # bytes of string already reported */
+
+	/* Buffer for receiving various parts of messages */
+	PQExpBufferData workBuffer; /* expansible string */
+};
+
+/* PGcancel stores all data necessary to cancel a connection. A copy of this
+ * data is required to safely cancel a connection running on a different
+ * thread.
+ */
+struct pg_cancel
+{
+	SockAddr	raddr;			/* Remote address */
+	int			be_pid;			/* PID of backend --- needed for cancels */
+	int			be_key;			/* key of backend --- needed for cancels */
+	int			pgtcp_user_timeout; /* tcp user timeout */
+	int			keepalives;		/* use TCP keepalives? */
+	int			keepalives_idle;	/* time between TCP keepalives */
+	int			keepalives_interval;	/* time between TCP keepalive
+										 * retransmits */
+	int			keepalives_count;	/* maximum number of TCP keepalive
+									 * retransmits */
+};
+
+
+/* String descriptions of the ExecStatusTypes.
+ * direct use of this array is deprecated; call PQresStatus() instead.
+ */
+extern char *const pgresStatus[];
+
+
+#ifdef USE_SSL
+
+#ifndef WIN32
+#define USER_CERT_FILE		".postgresql/postgresql.crt"
+#define USER_KEY_FILE		".postgresql/postgresql.key"
+#define ROOT_CERT_FILE		".postgresql/root.crt"
+#define ROOT_CRL_FILE		".postgresql/root.crl"
+#else
+/* On Windows, the "home" directory is already PostgreSQL-specific */
+#define USER_CERT_FILE		"postgresql.crt"
+#define USER_KEY_FILE		"postgresql.key"
+#define ROOT_CERT_FILE		"root.crt"
+#define ROOT_CRL_FILE		"root.crl"
+#endif
+
+#endif							/* USE_SSL */
+
+/* ----------------
+ * Internal functions of libpq
+ * Functions declared here need to be visible across files of libpq,
+ * but are not intended to be called by applications.  We use the
+ * convention "pqXXX" for internal functions, vs. the "PQxxx" names
+ * used for application-visible routines.
+ * ----------------
+ */
+
+/* === in fe-connect.c === */
+
+extern void pqDropConnection(PGconn *conn, bool flushInput);
+extern int	pqPacketSend(PGconn *conn, char pack_type,
+						 const void *buf, size_t buf_len);
+extern bool pqGetHomeDirectory(char *buf, int bufsize);
+
+#ifdef ENABLE_THREAD_SAFETY
+extern pgthreadlock_t pg_g_threadlock;
+
+#define pglock_thread()		pg_g_threadlock(true)
+#define pgunlock_thread()	pg_g_threadlock(false)
+#else
+#define pglock_thread()		((void) 0)
+#define pgunlock_thread()	((void) 0)
+#endif
+
+/* === in fe-exec.c === */
+
+extern void pqSetResultError(PGresult *res, PQExpBuffer errorMessage, int offset);
+extern void *pqResultAlloc(PGresult *res, size_t nBytes, bool isBinary);
+extern char *pqResultStrdup(PGresult *res, const char *str);
+extern void pqClearAsyncResult(PGconn *conn);
+extern void pqSaveErrorResult(PGconn *conn);
+extern PGresult *pqPrepareAsyncResult(PGconn *conn);
+extern void pqInternalNotice(const PGNoticeHooks *hooks, const char *fmt,...) pg_attribute_printf(2, 3);
+extern void pqSaveMessageField(PGresult *res, char code,
+							   const char *value);
+extern void pqSaveParameterStatus(PGconn *conn, const char *name,
+								  const char *value);
+extern int	pqRowProcessor(PGconn *conn, const char **errmsgp);
+extern void pqCommandQueueAdvance(PGconn *conn);
+extern int	PQsendQueryContinue(PGconn *conn, const char *query);
+
+/* === in fe-protocol3.c === */
+
+extern char *pqBuildStartupPacket3(PGconn *conn, int *packetlen,
+								   const PQEnvironmentOption *options);
+extern void pqParseInput3(PGconn *conn);
+extern int	pqGetErrorNotice3(PGconn *conn, bool isError);
+extern void pqBuildErrorMessage3(PQExpBuffer msg, const PGresult *res,
+								 PGVerbosity verbosity, PGContextVisibility show_context);
+extern int	pqGetCopyData3(PGconn *conn, char **buffer, int async);
+extern int	pqGetline3(PGconn *conn, char *s, int maxlen);
+extern int	pqGetlineAsync3(PGconn *conn, char *buffer, int bufsize);
+extern int	pqEndcopy3(PGconn *conn);
+extern PGresult *pqFunctionCall3(PGconn *conn, Oid fnid,
+								 int *result_buf, int *actual_result_len,
+								 int result_is_int,
+								 const PQArgBlock *args, int nargs);
+
+/* === in fe-misc.c === */
+
+ /*
+  * "Get" and "Put" routines return 0 if successful, EOF if not. Note that for
+  * Get, EOF merely means the buffer is exhausted, not that there is
+  * necessarily any error.
+  */
+extern int	pqCheckOutBufferSpace(size_t bytes_needed, PGconn *conn);
+extern int	pqCheckInBufferSpace(size_t bytes_needed, PGconn *conn);
+extern int	pqGetc(char *result, PGconn *conn);
+extern int	pqPutc(char c, PGconn *conn);
+extern int	pqGets(PQExpBuffer buf, PGconn *conn);
+extern int	pqGets_append(PQExpBuffer buf, PGconn *conn);
+extern int	pqPuts(const char *s, PGconn *conn);
+extern int	pqGetnchar(char *s, size_t len, PGconn *conn);
+extern int	pqSkipnchar(size_t len, PGconn *conn);
+extern int	pqPutnchar(const char *s, size_t len, PGconn *conn);
+extern int	pqGetInt(int *result, size_t bytes, PGconn *conn);
+extern int	pqPutInt(int value, size_t bytes, PGconn *conn);
+extern int	pqPutMsgStart(char msg_type, PGconn *conn);
+extern int	pqPutMsgEnd(PGconn *conn);
+extern int	pqReadData(PGconn *conn);
+extern int	pqFlush(PGconn *conn);
+extern int	pqWait(int forRead, int forWrite, PGconn *conn);
+extern int	pqWaitTimed(int forRead, int forWrite, PGconn *conn,
+						time_t finish_time);
+extern int	pqReadReady(PGconn *conn);
+extern int	pqWriteReady(PGconn *conn);
+
+/* === in fe-secure.c === */
+
+extern int	pqsecure_initialize(PGconn *, bool, bool);
+extern PostgresPollingStatusType pqsecure_open_client(PGconn *);
+extern void pqsecure_close(PGconn *);
+extern ssize_t pqsecure_read(PGconn *, void *ptr, size_t len);
+extern ssize_t pqsecure_write(PGconn *, const void *ptr, size_t len);
+extern ssize_t pqsecure_raw_read(PGconn *, void *ptr, size_t len);
+extern ssize_t pqsecure_raw_write(PGconn *, const void *ptr, size_t len);
+
+#if defined(ENABLE_THREAD_SAFETY) && !defined(WIN32)
+extern int	pq_block_sigpipe(sigset_t *osigset, bool *sigpipe_pending);
+extern void pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending,
+							 bool got_epipe);
+#endif
+
+/* === SSL === */
+
+/*
+ * The SSL implementation provides these functions.
+ */
+
+/*
+ *	Implementation of PQinitSSL().
+ */
+extern void pgtls_init_library(bool do_ssl, int do_crypto);
+
+/*
+ * Initialize SSL library.
+ *
+ * The conn parameter is only used to be able to pass back an error
+ * message - no connection-local setup is made here.  do_ssl controls
+ * if SSL is initialized, and do_crypto does the same for the crypto
+ * part.
+ *
+ * Returns 0 if OK, -1 on failure (adding a message to conn->errorMessage).
+ */
+extern int	pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto);
+
+/*
+ *	Begin or continue negotiating a secure session.
+ */
+extern PostgresPollingStatusType pgtls_open_client(PGconn *conn);
+
+/*
+ *	Close SSL connection.
+ */
+extern void pgtls_close(PGconn *conn);
+
+/*
+ *	Read data from a secure connection.
+ *
+ * On failure, this function is responsible for appending a suitable message
+ * to conn->errorMessage.  The caller must still inspect errno, but only
+ * to determine whether to continue/retry after error.
+ */
+extern ssize_t pgtls_read(PGconn *conn, void *ptr, size_t len);
+
+/*
+ *	Is there unread data waiting in the SSL read buffer?
+ */
+extern bool pgtls_read_pending(PGconn *conn);
+
+/*
+ *	Write data to a secure connection.
+ *
+ * On failure, this function is responsible for appending a suitable message
+ * to conn->errorMessage.  The caller must still inspect errno, but only
+ * to determine whether to continue/retry after error.
+ */
+extern ssize_t pgtls_write(PGconn *conn, const void *ptr, size_t len);
+
+/*
+ * Get the hash of the server certificate, for SCRAM channel binding type
+ * tls-server-end-point.
+ *
+ * NULL is sent back to the caller in the event of an error, with an
+ * error message for the caller to consume.
+ *
+ * This is not supported with old versions of OpenSSL that don't have
+ * the X509_get_signature_nid() function.
+ */
+#if defined(USE_OPENSSL) && (defined(HAVE_X509_GET_SIGNATURE_NID) || defined(HAVE_X509_GET_SIGNATURE_INFO))
+#define HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH
+extern char *pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len);
+#endif
+
+/*
+ * Verify that the server certificate matches the host name we connected to.
+ *
+ * The certificate's Common Name and Subject Alternative Names are considered.
+ *
+ * Returns 1 if the name matches, and 0 if it does not. On error, returns
+ * -1, and sets the libpq error message.
+ *
+ */
+extern int	pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
+															int *names_examined,
+															char **first_name);
+
+/* === GSSAPI === */
+
+#ifdef ENABLE_GSS
+
+/*
+ * Establish a GSSAPI-encrypted connection.
+ */
+extern PostgresPollingStatusType pqsecure_open_gss(PGconn *conn);
+
+/*
+ * Read and write functions for GSSAPI-encrypted connections, with internal
+ * buffering to handle nonblocking sockets.
+ */
+extern ssize_t pg_GSS_write(PGconn *conn, const void *ptr, size_t len);
+extern ssize_t pg_GSS_read(PGconn *conn, void *ptr, size_t len);
+#endif
+
+/* === in libpq-trace.c === */
+
+extern void pqTraceOutputMessage(PGconn *conn, const char *message,
+								 bool toServer);
+extern void pqTraceOutputNoTypeByteMessage(PGconn *conn, const char *message);
+
+/* === miscellaneous macros === */
+
+/*
+ * Reset the conn's error-reporting state.
+ */
+#define pqClearConnErrorState(conn) \
+	(resetPQExpBuffer(&(conn)->errorMessage), \
+	 (conn)->errorReported = 0)
+
+/*
+ * Check whether we have a PGresult pending to be returned --- either a
+ * constructed one in conn->result, or a "virtual" error result that we
+ * don't intend to materialize until the end of the query cycle.
+ */
+#define pgHavePendingResult(conn) \
+	((conn)->result != NULL || (conn)->error_result)
+
+/*
+ * this is so that we can check if a connection is non-blocking internally
+ * without the overhead of a function call
+ */
+#define pqIsnonblocking(conn)	((conn)->nonblocking)
+
+/*
+ * Connection's outbuffer threshold, for pipeline mode.
+ */
+#define OUTBUFFER_THRESHOLD	65536
+
+#ifdef ENABLE_NLS
+extern char *libpq_gettext(const char *msgid) pg_attribute_format_arg(1);
+extern char *libpq_ngettext(const char *msgid, const char *msgid_plural, unsigned long n) pg_attribute_format_arg(1) pg_attribute_format_arg(2);
+#else
+#define libpq_gettext(x) (x)
+#define libpq_ngettext(s, p, n) ((n) == 1 ? (s) : (p))
+#endif
+/*
+ * libpq code should use the above, not _(), since that would use the
+ * surrounding programs's message catalog.
+ */
+#undef _
+
+/*
+ * These macros are needed to let error-handling code be portable between
+ * Unix and Windows.  (ugh)
+ */
+#ifdef WIN32
+#define SOCK_ERRNO (WSAGetLastError())
+#define SOCK_STRERROR winsock_strerror
+#define SOCK_ERRNO_SET(e) WSASetLastError(e)
+#else
+#define SOCK_ERRNO errno
+#define SOCK_STRERROR strerror_r
+#define SOCK_ERRNO_SET(e) (errno = (e))
+#endif
+
+#endif							/* LIBPQ_INT_H */