putty-source/ldisc.h

/*
 * 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 */
Richard points out that it would probably help if I committed ldisc.h. Bah. :-) [originally from svn r2146] 2002-10-26 12:42:07 +00:00			`/*`
			`* 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`

Expose the Ldisc structure tag throughout the code. That's one fewer anonymous 'void *' which might be accidentally confused with some other pointer type if I misremember the order of function arguments. While I'm here, I've made its pointer-nature explicit - that is, 'Ldisc' is now a typedef for the structure type itself rather than a pointer to it. A stylistic change only, but it feels more natural to me these days for a thing you're going to eventually pass to a 'free' function. 2018-09-11 14:02:59 +00:00			`struct Ldisc_tag {`
Richard points out that it would probably help if I committed ldisc.h. Bah. :-) [originally from svn r2146] 2002-10-26 12:42:07 +00:00			`Terminal *term;`
Turn Backend into a sensible classoid. Nearly every part of the code that ever handles a full backend structure has historically done it using a pair of pointer variables, one pointing at a constant struct full of function pointers, and the other pointing to a 'void *' state object that's passed to each of those. While I'm modernising the rest of the code, this seems like a good time to turn that into the same more or less type-safe and less cumbersome system as I'm using for other parts of the code, such as Socket, Plug, BinaryPacketProtocol and so forth: the Backend structure contains a vtable pointer, and a system of macro wrappers handles dispatching through that vtable. 2018-09-11 15:23:38 +00:00			`Backend *backend;`
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 18:58:42 +00:00			`Seat *seat;`
Richard points out that it would probably help if I committed ldisc.h. Bah. :-) [originally from svn r2146] 2002-10-26 12:42:07 +00:00
Post-release destabilisation! Completely remove the struct type 'Config' in putty.h, which stores all PuTTY's settings and includes an arbitrary length limit on every single one of those settings which is stored in string form. In place of it is 'Conf', an opaque data type everywhere outside the new file conf.c, which stores a list of (key, value) pairs in which every key contains an integer identifying a configuration setting, and for some of those integers the key also contains extra parts (so that, for instance, CONF_environmt is a string-to-string mapping). Everywhere that a Config was previously used, a Conf is now; everywhere there was a Config structure copy, conf_copy() is called; every lookup, adjustment, load and save operation on a Config has been rewritten; and there's a mechanism for serialising a Conf into a binary blob and back for use with Duplicate Session. User-visible effects of this change _should_ be minimal, though I don't doubt I've introduced one or two bugs here and there which will eventually be found. The _intended_ visible effects of this change are that all arbitrary limits on configuration strings and lists (e.g. limit on number of port forwardings) should now disappear; that list boxes in the configuration will now be displayed in a sorted order rather than the arbitrary order in which they were added to the list (since the underlying data structure is now a sorted tree234 rather than an ad-hoc comma-separated string); and one more specific change, which is that local and dynamic port forwardings on the same port number are now mutually exclusive in the configuration (putting 'D' in the key rather than the value was a mistake in the first place). One other reorganisation as a result of this is that I've moved all the dialog.c standard handlers (dlg_stdeditbox_handler and friends) out into config.c, because I can't really justify calling them generic any more. When they took a pointer to an arbitrary structure type and the offset of a field within that structure, they were independent of whether that structure was a Config or something completely different, but now they really do expect to talk to a Conf, which can _only_ be used for PuTTY configuration, so I've renamed them all things like conf_editbox_handler and moved them out of the nominally independent dialog-box management module into the PuTTY-specific config.c. [originally from svn r9214] 2011-07-14 18:52:21 +00:00			`/*`
			`* Values cached out of conf.`
			`*/`
			`int telnet_keyboard, telnet_newline, protocol, localecho, localedit;`

Richard points out that it would probably help if I committed ldisc.h. Bah. :-) [originally from svn r2146] 2002-10-26 12:42:07 +00:00			`char *buf;`
			`int buflen, bufsiz, quotenext;`
Expose the Ldisc structure tag throughout the code. That's one fewer anonymous 'void *' which might be accidentally confused with some other pointer type if I misremember the order of function arguments. While I'm here, I've made its pointer-nature explicit - that is, 'Ldisc' is now a typedef for the structure type itself rather than a pointer to it. A stylistic change only, but it feels more natural to me these days for a thing you're going to eventually pass to a 'free' function. 2018-09-11 14:02:59 +00:00			`};`
Richard points out that it would probably help if I committed ldisc.h. Bah. :-) [originally from svn r2146] 2002-10-26 12:42:07 +00:00
			`#endif /* PUTTY_LDISC_H */`