postgresql/src/include/libpq/libpq-be.h

/*-------------------------------------------------------------------------
 *
 * libpq-be.h--
 *	  This file contains definitions for structures and
 *	  externs for functions used by the POSTGRES backend.
 *
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 * $Id: libpq-be.h,v 1.9 1998/01/26 01:42:17 scrappy Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef LIBPQ_BE_H
#define LIBPQ_BE_H

#include <stdio.h>
#include <sys/types.h>

#include "libpq/pqcomm.h"
#include "libpq/hba.h"


/* Protocol v0 password packet. */

typedef struct PasswordPacketV0 {
	uint32		unused;
	char		data[288];		/* User and password as strings. */
} PasswordPacketV0;


/*
 * Password packet.  The length of the password can be changed without
 * affecting anything.
 */
  
typedef struct PasswordPacket {
	char		passwd[100];		/* The password. */
} PasswordPacket;


/* Error message packet. */

typedef struct ErrorMessagePacket {
	char		data[1 + 100];		/* 'E' + the message. */
} ErrorMessagePacket;


/* Authentication request packet. */

typedef struct AuthRequestPacket {
	char		data[1 + sizeof (AuthRequest) + 2];	/* 'R' + the request + optional salt. */
} AuthRequestPacket;

  
/* These are used by the packet handling routines. */

typedef enum {
	Idle,
	ReadingPacketLength,
	ReadingPacket,
	WritingPacket
} PacketState;

typedef struct Packet {
	PacketState	state;			/* What's in progress. */
	PacketLen	len;			/* Actual length */
	int		nrtodo;			/* Bytes still to transfer */
	char		*ptr;			/* Buffer pointer */
	void		(*iodone)();		/* I/O complete callback */
	char		*arg;			/* Argument to callback */

	/* A union of all the different packets. */

	union {
		/* These are outgoing so have no packet length prepended. */

		ErrorMessagePacket	em;
		AuthRequestPacket	ar;

		/* These are incoming and have a packet length prepended. */

		StartupPacket		si;
		PasswordPacketV0	pwv0;
		PasswordPacket		pw;
	} pkt;
} Packet;


/*
 * This is used by the postmaster in its communication with frontends.  It is
 * contains all state information needed during this communication before the
 * backend is run.
 */
  
typedef struct Port {
	int		sock;			/* File descriptor */
	Packet		pktInfo;		/* For the packet handlers */
	SockAddr	laddr;			/* local addr (us) */
	SockAddr	raddr;			/* remote addr (them) */
	char		salt[2];		/* Password salt */

	/*
	 * Information that needs to be held during the fe/be authentication
	 * handshake.
	 */

	ProtocolVersion	proto;
	char		database[SM_DATABASE + 1];
	char		user[SM_USER + 1];
	char		options[SM_OPTIONS + 1];
	char		tty[SM_TTY + 1];
	char		auth_arg[MAX_AUTH_ARG];
	UserAuth	auth_method;
} Port;


extern FILE *Pfout, *Pfin;
extern int PQAsyncNotifyWaiting;
extern ProtocolVersion FrontendProtocol;


/*
 * prototypes for functions in pqpacket.c
 */
void PacketReceiveSetup(Packet *pkt, void (*iodone)(), char *arg);
int PacketReceiveFragment(Packet *pkt, int sock);
void PacketSendSetup(Packet *pkt, int nbytes, void (*iodone)(), char *arg);
int PacketSendFragment(Packet *pkt, int sock);
void PacketSendError(Packet *pkt, char *errormsg);
  
#endif							/* LIBPQ_BE_H */