putty/defs.h

108 строки
2.9 KiB
C
Исходник Обычный вид История

/*
* defs.h: initial definitions for PuTTY.
*
* The rule about this header file is that it can't depend on any
* other header file in this code base. This is where we define
* things, as much as we can, that other headers will want to refer
* to, such as opaque structure types and their associated typedefs,
* or macros that are used by other headers.
*/
#ifndef PUTTY_DEFS_H
#define PUTTY_DEFS_H
#include <stddef.h>
#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif
typedef struct conf_tag Conf;
typedef struct terminal_tag Terminal;
typedef struct Filename Filename;
typedef struct FontSpec FontSpec;
typedef struct bufchain_tag bufchain;
typedef struct strbuf strbuf;
struct RSAKey;
#include <stdint.h>
typedef uint32_t uint32;
New centralised binary-data marshalling system. I've finally got tired of all the code throughout PuTTY that repeats the same logic about how to format the SSH binary primitives like uint32, string, mpint. We've got reasonably organised code in ssh.c that appends things like that to 'struct Packet'; something similar in sftp.c which repeats a lot of the work; utility functions in various places to format an mpint to feed to one or another hash function; and no end of totally ad-hoc stuff in functions like public key blob formatters which actually have to _count up_ the size of data painstakingly, then malloc exactly that much and mess about with PUT_32BIT. It's time to bring all of that into one place, and stop repeating myself in error-prone ways everywhere. The new marshal.h defines a system in which I centralise all the actual marshalling functions, and then layer a touch of C macro trickery on top to allow me to (look as if I) pass a wide range of different types to those functions, as long as the target type has been set up in the right way to have a write() function. This commit adds the new header and source file, and sets up some general centralised types (strbuf and the various hash-function contexts like SHA_State), but doesn't use the new calls for anything yet. (I've also renamed some internal functions in import.c which were using the same names that I've just defined macros over. That won't last long - those functions are going to go away soon, so the changed names are strictly temporary.)
2018-05-24 11:17:13 +03:00
typedef struct BinarySink BinarySink;
typedef struct BinarySource BinarySource;
New centralised binary-data marshalling system. I've finally got tired of all the code throughout PuTTY that repeats the same logic about how to format the SSH binary primitives like uint32, string, mpint. We've got reasonably organised code in ssh.c that appends things like that to 'struct Packet'; something similar in sftp.c which repeats a lot of the work; utility functions in various places to format an mpint to feed to one or another hash function; and no end of totally ad-hoc stuff in functions like public key blob formatters which actually have to _count up_ the size of data painstakingly, then malloc exactly that much and mess about with PUT_32BIT. It's time to bring all of that into one place, and stop repeating myself in error-prone ways everywhere. The new marshal.h defines a system in which I centralise all the actual marshalling functions, and then layer a touch of C macro trickery on top to allow me to (look as if I) pass a wide range of different types to those functions, as long as the target type has been set up in the right way to have a write() function. This commit adds the new header and source file, and sets up some general centralised types (strbuf and the various hash-function contexts like SHA_State), but doesn't use the new calls for anything yet. (I've also renamed some internal functions in import.c which were using the same names that I've just defined macros over. That won't last long - those functions are going to go away soon, so the changed names are strictly temporary.)
2018-05-24 11:17:13 +03:00
typedef struct IdempotentCallback IdempotentCallback;
typedef struct SockAddr SockAddr;
typedef struct SocketVtable SocketVtable;
typedef struct PlugVtable PlugVtable;
typedef struct Backend Backend;
typedef struct BackendVtable BackendVtable;
typedef struct Ldisc_tag Ldisc;
typedef struct LogContext_tag LogContext;
typedef struct Frontend Frontend;
typedef struct Ssh Ssh;
typedef struct Channel Channel;
typedef struct SshChannel SshChannel;
typedef struct ssh_sharing_state ssh_sharing_state;
typedef struct ssh_sharing_connstate ssh_sharing_connstate;
typedef struct share_channel share_channel;
typedef struct PortFwdManager PortFwdManager;
typedef struct PortFwdRecord PortFwdRecord;
typedef struct ConnectionLayer ConnectionLayer;
typedef struct dlgparam dlgparam;
typedef struct settings_w settings_w;
typedef struct settings_r settings_r;
typedef struct settings_e settings_e;
typedef struct SessionSpecial SessionSpecial;
typedef const SocketVtable *Socket;
typedef const PlugVtable *Plug;
/*
* A small structure wrapping up a (pointer, length) pair so that it
* can be conveniently passed to or from a function.
*/
typedef struct ptrlen {
const void *ptr;
size_t len;
} ptrlen;
typedef struct logblank_t logblank_t;
typedef struct BinaryPacketProtocol BinaryPacketProtocol;
Move most of ssh.c out into separate source files. I've tried to separate out as many individually coherent changes from this work as I could into their own commits, but here's where I run out and have to commit the rest of this major refactoring as a big-bang change. Most of ssh.c is now no longer in ssh.c: all five of the main coroutines that handle layers of the SSH-1 and SSH-2 protocols now each have their own source file to live in, and a lot of the supporting functions have moved into the appropriate one of those too. The new abstraction is a vtable called 'PacketProtocolLayer', which has an input and output packet queue. Each layer's main coroutine is invoked from the method ssh_ppl_process_queue(), which is usually (though not exclusively) triggered automatically when things are pushed on the input queue. In SSH-2, the base layer is the transport protocol, and it contains a pair of subsidiary queues by which it passes some of its packets to the higher SSH-2 layers - first userauth and then connection, which are peers at the same level, with the former abdicating in favour of the latter at the appropriate moment. SSH-1 is simpler: the whole login phase of the protocol (crypto setup and authentication) is all in one module, and since SSH-1 has no repeat key exchange, that setup layer abdicates in favour of the connection phase when it's done. ssh.c itself is now about a tenth of its old size (which all by itself is cause for celebration!). Its main job is to set up all the layers, hook them up to each other and to the BPP, and to funnel data back and forth between that collection of modules and external things such as the network and the terminal. Once it's set up a collection of packet protocol layers, it communicates with them partly by calling methods of the base layer (and if that's ssh2transport then it will delegate some functionality to the corresponding methods of its higher layer), and partly by talking directly to the connection layer no matter where it is in the stack by means of the separate ConnectionLayer vtable which I introduced in commit 8001dd4cb, and to which I've now added quite a few extra methods replacing services that used to be internal function calls within ssh.c. (One effect of this is that the SSH-1 and SSH-2 channel storage is now no longer shared - there are distinct struct types ssh1_channel and ssh2_channel. That means a bit more code duplication, but on the plus side, a lot fewer confusing conditionals in the middle of half-shared functions, and less risk of a piece of SSH-1 escaping into SSH-2 or vice versa, which I remember has happened at least once in the past.) The bulk of this commit introduces the five new source files, their common header sshppl.h and some shared supporting routines in sshcommon.c, and rewrites nearly all of ssh.c itself. But it also includes a couple of other changes that I couldn't separate easily enough: Firstly, there's a new handling for socket EOF, in which ssh.c sets an 'input_eof' flag in the BPP, and that responds by checking a flag that tells it whether to report the EOF as an error or not. (This is the main reason for those new BPP_READ / BPP_WAITFOR macros - they can check the EOF flag every time the coroutine is resumed.) Secondly, the error reporting itself is changed around again. I'd expected to put some data fields in the public PacketProtocolLayer structure that it could set to report errors in the same way as the BPPs have been doing, but in the end, I decided propagating all those data fields around was a pain and that even the BPPs shouldn't have been doing it that way. So I've reverted to a system where everything calls back to functions in ssh.c itself to report any connection- ending condition. But there's a new family of those functions, categorising the possible such conditions by semantics, and each one has a different set of detailed effects (e.g. how rudely to close the network connection, what exit status should be passed back to the whole application, whether to send a disconnect message and/or display a GUI error box). I don't expect this to be immediately perfect: of course, the code has been through a big upheaval, new bugs are expected, and I haven't been able to do a full job of testing (e.g. I haven't tested every auth or kex method). But I've checked that it _basically_ works - both SSH protocols, all the different kinds of forwarding channel, more than one auth method, Windows and Linux, connection sharing - and I think it's now at the point where the easiest way to find further bugs is to let it out into the wild and see what users can spot.
2018-09-24 20:28:16 +03:00
typedef struct PacketProtocolLayer PacketProtocolLayer;
/* Do a compile-time type-check of 'to_check' (without evaluating it),
* as a side effect of returning the value 'to_return'. Note that
* although this macro double-*expands* to_return, it always
* *evaluates* exactly one copy of it, so it's side-effect safe. */
#define TYPECHECK(to_check, to_return) \
(sizeof(to_check) ? (to_return) : (to_return))
/* Return a pointer to the object of structure type 'type' whose field
* with name 'field' is pointed at by 'object'. */
#define FROMFIELD(object, type, field) \
TYPECHECK(object == &((type *)0)->field, \
((type *)(((char *)(object)) - offsetof(type, field))))
#endif /* PUTTY_DEFS_H */