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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-09 17:38:00 +00:00
putty-source/ldisc.h
Simon Tatham b4c8fd9d86 New abstraction 'Seat', to pass to backends.
This is a new vtable-based abstraction which is passed to a backend in
place of Frontend, and it implements only the subset of the Frontend
functions needed by a backend. (Many other Frontend functions still
exist, notably the wide range of things called by terminal.c providing
platform-independent operations on the GUI terminal window.)

The purpose of making it a vtable is that this opens up the
possibility of creating a backend as an internal implementation detail
of some other activity, by providing just that one backend with a
custom Seat that implements the methods differently.

For example, this refactoring should make it feasible to directly
implement an SSH proxy type, aka the 'jump host' feature supported by
OpenSSH, aka 'open a secondary SSH session in MAINCHAN_DIRECT_TCP
mode, and then expose the main channel of that as the Socket for the
primary connection'. (Which of course you can already do by spawning
'plink -nc' as a separate proxy process, but this would permit it in
the _same_ process without anything getting confused.)

I've centralised a full set of stub methods in misc.c for the new
abstraction, which allows me to get rid of several annoying stubs in
the previous code. Also, while I'm here, I've moved a lot of
duplicated modalfatalbox() type functions from application main
program files into wincons.c / uxcons.c, which I think saves
duplication overall. (A minor visible effect is that the prefixes on
those console-based fatal error messages will now be more consistent
between applications.)
2018-10-11 19:58:42 +01:00

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C

/*
* ldisc.h: defines the Ldisc data structure used by ldisc.c and
* ldiscucs.c. (Unfortunately it was necessary to split the ldisc
* module in two, to avoid unnecessarily linking in the Unicode
* stuff in tools that don't require it.)
*/
#ifndef PUTTY_LDISC_H
#define PUTTY_LDISC_H
struct Ldisc_tag {
Terminal *term;
Backend *backend;
Seat *seat;
/*
* Values cached out of conf.
*/
int telnet_keyboard, telnet_newline, protocol, localecho, localedit;
char *buf;
int buflen, bufsiz, quotenext;
};
#endif /* PUTTY_LDISC_H */