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/*
* uw protocol
*
* Copyright 1985,1986 by John D. Bruner. All rights reserved. Permission to
* copy this program is given provided that the copy is not sold and that
* this copyright notice is included.
*/
#ifndef UW_PCL
#define UW_PCL
#include "uw_win.h"
/* UW may operate over connections which speak one of several protocols.
* Internally these protocols are assigned numbers starting at zero.
* Three such protocols are currently defined:
*
* 0: no special protocol
* 1: original UW (v1.6, v2.10) protocol
* 2: extended protocol (v3.x)
*/
/*
* Protocol 0:
*
* The connection between the Macintosh and the host is simply a serial
* line. Flow control may be enabled, but no special commands are
* recognized. Only one active window is supported. This "protocol"
* does not require the UW server; hence, there is no need to support it.
*/
/*
* Protocol 1: (original UW protocol)
*
* Two types of information are exchanged through the 7-bit serial line:
* ordinary data and command bytes. Command bytes are preceeded by
* an IAC byte. IAC bytes and literal XON/XOFF characters (those which
* are not used for flow control) are sent by a P1_FN_CTLCH command.
* Characters with the eighth bit set (the "meta" bit) are prefixed with
* a P1_FN_META function.
*
* The next most-significant bit in the byte specifies the sender and
* recipient of the command. If this bit is clear (0), the command byte
* was sent from the host computer to the Macintosh; if it is set (1)
* the command byte was sent from the Macintosh to the host computer.
* This prevents confusion in the event that the host computer
* (incorrectly) echos a command back to the Macintosh.
*
* The remaining six bits are partitioned into two fields. The low-order
* three bits specify a window number from 1-7 (window 0 is reserved for
* other uses) or another type of command-dependent parameter. The next
* three bits specify the operation to be performed by the recipient of
* the command byte.
*
* Note that the choice of command bytes prevents the ASCII XON (021) and
* XOFF (023) characters from being sent as commands. P1_FN_ISELW commands
* are only sent by the Macintosh (and thus are tagged with the P1_DIR_MTOH
* bit). Since XON and XOFF data characters are handled via P1_FN_CTLCH,
* this allows them to be used for flow control purposes.
*/
#define P1_IAC 0001 /* interpret as command */
#define P1_DIR 0100 /* command direction: */
#define P1_DIR_HTOM 0000 /* from host to Mac */
#define P1_DIR_MTOH 0100 /* from Mac to host */
#define P1_FN 0070 /* function code: */
#define P1_FN_NEWW 0000 /* new window */
#define P1_FN_KILLW 0010 /* kill (delete) window */
#define P1_FN_ISELW 0020 /* select window for input */
#define P1_FN_OSELW 0030 /* select window for output */
#define P1_FN_META 0050 /* add meta to next data char */
#define P1_FN_CTLCH 0060 /* low 3 bits specify char */
#define P1_FN_MAINT 0070 /* maintenance functions */
#define P1_WINDOW 0007 /* window number mask */
#define P1_CC 0007 /* control character specifier: */
#define P1_CC_IAC 1 /* IAC */
#define P1_CC_XON 2 /* XON */
#define P1_CC_XOFF 3 /* XOFF */
#define P1_MF 0007 /* maintenance functions: */
#define P1_MF_ENTRY 0 /* beginning execution */
#define P1_MF_ASKPCL 2 /* request protocol negotiation */
#define P1_MF_CANPCL 3 /* suggest protocol */
#define P1_MF_SETPCL 4 /* set current protocol */
#define P1_MF_EXIT 7 /* execution terminating */
#define P1_NWINDOW 7 /* maximum number of windows */
/*
* Protocol 2: (extended UW protocol)
*
* Protocol 2 is an extension of protocol 1. The P2_FN_NEWW command and
* the new command P2_FN_WOPT communicate window options between the host
* and the Macintosh. (See "uw_opt.h" for details.)
*/
#define P2_IAC P1_IAC /* interpret as command */
#define P2_DIR P1_DIR /* command direction: */
#define P2_DIR_HTOM P1_DIR_HTOM /* from host to Mac */
#define P2_DIR_MTOH P1_DIR_MTOH /* from Mac to host */
#define P2_FN P1_FN /* function code: */
#define P2_FN_NEWW P1_FN_NEWW /* new window */
#define P2_FN_KILLW P1_FN_KILLW /* kill (delete) window */
#define P2_FN_ISELW P1_FN_ISELW /* select window for input */
#define P2_FN_OSELW P1_FN_OSELW /* select window for output */
#define P2_FN_WOPT 0040 /* communicate window options */
#define P2_FN_META P1_FN_META /* add meta to next data char */
#define P2_FN_CTLCH P1_FN_CTLCH /* low 3 bits specify char */
#define P2_FN_MAINT P1_FN_MAINT /* maintenance functions */
#define P2_WINDOW P1_WINDOW /* window number mask */
#define P2_CC P1_CC /* control character specifier: */
#define P2_CC_IAC P1_CC_IAC /* IAC */
#define P2_CC_XON P1_CC_XON /* XON */
#define P2_CC_XOFF P1_CC_XOFF /* XOFF */
#define P2_MF P1_MF /* maintenance functions: */
#define P2_MF_ENTRY P1_MF_ENTRY /* beginning execution */
#define P2_MF_ASKPCL P1_MF_ASKPCL /* request protocol negotiation */
#define P2_MF_CANPCL P1_MF_CANPCL /* suggest protocol */
#define P2_MF_SETPCL P1_MF_SETPCL /* set current protocol */
#define P2_MF_EXIT P1_MF_EXIT /* execution terminating */
#define P2_NWINDOW P1_NWINDOW /* maximum number of windows */
/*
* Protocol negotiation
*
* The server is not used for protocol 0. For the other protocols, the
* Macintosh and the server negotiate to select the active protocol. The
* basic idea is that the Macintosh will express its desire for a protocol
* and the server will attempt to satisfy that desire. Until negotiations
* are complete, protocol 1 is used.
*
* Protocols are identified by single-character names which are formed by
* adding the ASCII code for a space (040) to the protocol number minus 1
* (i.e. protocol 1 is ' ', protocol 2 is '!').
*
* P1_FN_CANPCL and P1_FN_SETPCL are three-byte commands: P1_IAC,
* P1_FN_XXXPCL, protocol-name.
*
* Macintosh:
* If UW v2.10 is used on the Macintosh or if a newer Macintosh program
* wishes to use protocol 1, it will never initiate protocol negotiation.
* Hence, all interaction will use protocol 1 by default.
*
* If the Macintosh program is capable of supporting protocol 2 and the
* user requests its use, the Mac will remember this fact but will
* continue to use protocol 1. The Mac program will assume that no
* server is present until instructed otherwise by the user or until a
* P1_FN_ENTRY command is received (e.g. when the server starts up).
* At this time, the Mac program issues P1_FN_ASKPCL. If the server
* cannot support protocol 2 (i.e. it is an old server), then it will
* ignore the P1_FN_ASKPCL. The Macintosh will retry the P1_FN_ASKPCL
* a couple of times (about five seconds apart) and, if there is no
* response from the server, will abandon negotiations. Protocol 1
* will be used for the remainder of the session.
*
* If the server recognizes the P1_FN_ASKPCL command it will respond
* with the name of the most complex protocol it can support (currently
* '!'). If this is acceptable to the Macintosh, it will instruct the
* server to use this protocol. If the Macintosh cannot support this
* protocol it will respond with a P1_FN_CANPCL suggesting a less-complex
* protocol. If the server agrees to this it will answer establish the
* protocol; otherwise, it will suggest an even weaker protocol.
* Eventually someone will suggest protocol 1 (which is universal) and
* the other side will issue a P1_FN_SETPCL command to establish its use.
*
* Host:
* If the host receives a P1_FN_ASKPCL it will respond with the most
* complex protocol it can support (using the P1_FN_CANPCL command).
* Negotiations will proceed as described above until one side
* establishes a new protocol with P1_FN_SETPCL. At this time, the
* host will switch to the new protocol.
*
* If the host receives a P1_FN_ENTRY (P2_FN_ENTRY) command, it will
* switch back to protocol 1. Receipt of this command indicates that
* the Macintosh program was restarted. The Macintosh must initiate
* protocol negotiations again.
*/
/*
* Although many of the functions are identical (and the code is shared
* between them), each protocol is accessed through a (struct protocol)
* which specifies the functions for various operations.
*
* In theory, the main program knows nothing about the protocol in use.
* In practice, the externally-visible functions are accessed as macros
* for greater efficiency.
*
* The protocol layer is aware of the (struct window) data structures.
*/
struct protocol {
char p_name; /* single-character protocol name */
nwin_t p_maxwin; /* maximum window number */
int *p_ctlch; /* control character map table */
unsigned p_szctlch; /* size (# of entries) in ctlch table */
void (*p_entry)(); /* start up (ENTRY maintenance fn) */
void (*p_exit)(); /* shut down (EXIT maintenance fn) */
void (*p_renew)(); /* renew (re-init) */
struct window *(*p_neww)(); /* create new window */
void (*p_killw)(); /* kill window */
void (*p_xmit)(); /* transmit to specified window */
void (*p_recv)(); /* receive from Macintosh */
void (*p_chkopt)(); /* check for pending option output */
void (*p_sendopt)(); /* send option string to Macintosh */
void (*p_askpcl)(); /* send an ASKPCL maintenance command */
void (*p_canpcl)(); /* send a CANPCL maintenance command */
void (*p_setpcl)(); /* send a SETPCL maintenance command */
};
extern struct protocol *protocol;
#define PCL_NEWW(mfd,class,wtype,wnum,wid,dfd,cfd) \
(*protocol->p_neww)(mfd,class,wtype,wnum,(long)wid,dfd,cfd)
#define PCL_KILLW(mfd,w) (*protocol->p_killw)(mfd,w)
#define PCL_RECV(mfd,buf,len) (*protocol->p_recv)(mfd,buf,len)
#define PCL_XMIT(mfd,w) (*protocol->p_xmit)(mfd,w)
#define PCL_SENDOPT(mfd,fn,buf,len) \
(protocol->p_sendopt ? (*protocol->p_sendopt)(mfd,fn,buf,len) : 0)
#endif
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.