putty/sshppl.h

174 строки
7.4 KiB
C

/*
* Abstraction of the various layers of SSH packet-level protocol,
* general enough to take in all three of the main SSH-2 layers and
* both of the SSH-1 phases.
*/
#ifndef PUTTY_SSHPPL_H
#define PUTTY_SSHPPL_H
typedef void (*packet_handler_fn_t)(PacketProtocolLayer *ppl, PktIn *pktin);
struct PacketProtocolLayerVtable {
void (*free)(PacketProtocolLayer *);
void (*process_queue)(PacketProtocolLayer *ppl);
bool (*get_specials)(
PacketProtocolLayer *ppl, add_special_fn_t add_special, void *ctx);
void (*special_cmd)(
PacketProtocolLayer *ppl, SessionSpecialCode code, int arg);
bool (*want_user_input)(PacketProtocolLayer *ppl);
void (*got_user_input)(PacketProtocolLayer *ppl);
void (*reconfigure)(PacketProtocolLayer *ppl, Conf *conf);
size_t (*queued_data_size)(PacketProtocolLayer *ppl);
/* Protocol-level name of this layer. */
const char *name;
};
struct PacketProtocolLayer {
const struct PacketProtocolLayerVtable *vt;
/* Link to the underlying SSH BPP. */
BinaryPacketProtocol *bpp;
/* Queue from which the layer receives its input packets, and one
* to put its output packets on. */
PktInQueue *in_pq;
PktOutQueue *out_pq;
/* Idempotent callback that in_pq will be linked to, causing a
* call to the process_queue method. in_pq points to this, so it
* will be automatically triggered by pushing things on the
* layer's input queue, but it can also be triggered on purpose. */
IdempotentCallback ic_process_queue;
/* Owner's pointer to this layer. Permits a layer to unilaterally
* abdicate in favour of a replacement, by overwriting this
* pointer and then freeing itself. */
PacketProtocolLayer **selfptr;
/* Bufchain of keyboard input from the user, for login prompts and
* similar. */
bufchain *user_input;
/* Logging and error-reporting facilities. */
LogContext *logctx;
Seat *seat; /* for dialog boxes, session output etc */
Ssh *ssh; /* for session termination + assorted connection-layer ops */
/* Known bugs in the remote implementation. */
unsigned remote_bugs;
};
static inline void ssh_ppl_process_queue(PacketProtocolLayer *ppl)
{ ppl->vt->process_queue(ppl); }
static inline bool ssh_ppl_get_specials(
PacketProtocolLayer *ppl, add_special_fn_t add_special, void *ctx)
{ return ppl->vt->get_specials(ppl, add_special, ctx); }
static inline void ssh_ppl_special_cmd(
PacketProtocolLayer *ppl, SessionSpecialCode code, int arg)
{ ppl->vt->special_cmd(ppl, code, arg); }
static inline bool ssh_ppl_want_user_input(PacketProtocolLayer *ppl)
{ return ppl->vt->want_user_input(ppl); }
static inline void ssh_ppl_got_user_input(PacketProtocolLayer *ppl)
{ ppl->vt->got_user_input(ppl); }
static inline void ssh_ppl_reconfigure(PacketProtocolLayer *ppl, Conf *conf)
{ ppl->vt->reconfigure(ppl, conf); }
static inline size_t ssh_ppl_queued_data_size(PacketProtocolLayer *ppl)
{ return ppl->vt->queued_data_size(ppl); }
/* ssh_ppl_free is more than just a macro wrapper on the vtable; it
* does centralised parts of the freeing too. */
void ssh_ppl_free(PacketProtocolLayer *ppl);
/* Helper routine to point a PPL at its input and output queues. Also
* sets up the IdempotentCallback on the input queue to trigger a call
* to process_queue whenever packets are added to it. */
void ssh_ppl_setup_queues(PacketProtocolLayer *ppl,
PktInQueue *inq, PktOutQueue *outq);
/* Routine a PPL can call to abdicate in favour of a replacement, by
* overwriting ppl->selfptr. Has the side effect of freeing 'old', so
* if 'old' actually called this (which is likely) then it should
* avoid dereferencing itself on return from this function! */
void ssh_ppl_replace(PacketProtocolLayer *old, PacketProtocolLayer *new);
/* Default implementation of queued_data_size, which just adds up the
* sizes of all the packets in pq_out. A layer can override this if it
* has other things to take into account as well. */
size_t ssh_ppl_default_queued_data_size(PacketProtocolLayer *ppl);
PacketProtocolLayer *ssh1_login_new(
Conf *conf, const char *host, int port,
PacketProtocolLayer *successor_layer);
PacketProtocolLayer *ssh1_connection_new(
Ssh *ssh, Conf *conf, ConnectionLayer **cl_out);
struct DataTransferStats;
struct ssh_connection_shared_gss_state;
PacketProtocolLayer *ssh2_transport_new(
Conf *conf, const char *host, int port, const char *fullhostname,
const char *client_greeting, const char *server_greeting,
struct ssh_connection_shared_gss_state *shgss,
struct DataTransferStats *stats, PacketProtocolLayer *higher_layer,
const SshServerConfig *ssc);
PacketProtocolLayer *ssh2_userauth_new(
PacketProtocolLayer *successor_layer,
const char *hostname, const char *fullhostname,
Filename *keyfile, bool show_banner, bool tryagent,
const char *default_username, bool change_username,
bool try_ki_auth,
bool try_gssapi_auth, bool try_gssapi_kex_auth,
bool gssapi_fwd, struct ssh_connection_shared_gss_state *shgss);
PacketProtocolLayer *ssh2_connection_new(
Ssh *ssh, ssh_sharing_state *connshare, bool is_simple,
Conf *conf, const char *peer_verstring, ConnectionLayer **cl_out);
/* Can't put this in the userauth constructor without having a
* dependency loop at setup time (transport and userauth can't _both_
* be constructed second and given a pointer to the other). */
void ssh2_userauth_set_transport_layer(PacketProtocolLayer *userauth,
PacketProtocolLayer *transport);
/* Convenience macro for protocol layers to send formatted strings to
* the Event Log. Assumes a function parameter called 'ppl' is in
* scope. */
#define ppl_logevent(...) ( \
logevent_and_free((ppl)->logctx, dupprintf(__VA_ARGS__)))
/* Convenience macro for protocol layers to send formatted strings to
* the terminal. Also expects 'ppl' to be in scope. */
#define ppl_printf(...) \
ssh_ppl_user_output_string_and_free(ppl, dupprintf(__VA_ARGS__))
void ssh_ppl_user_output_string_and_free(PacketProtocolLayer *ppl, char *text);
/* Methods for userauth to communicate back to the transport layer */
ptrlen ssh2_transport_get_session_id(PacketProtocolLayer *ssh2_transport_ptr);
void ssh2_transport_notify_auth_done(PacketProtocolLayer *ssh2_transport_ptr);
/* Shared method between ssh2 layers (defined in ssh2transport.c) to
* handle the common packets between login and connection: DISCONNECT,
* DEBUG and IGNORE. Those messages are handled by the ssh2transport
* layer if we have one, but in bare ssh2-connection mode they have to
* be handled by ssh2connection. */
bool ssh2_common_filter_queue(PacketProtocolLayer *ppl);
/* Methods for ssh1login to pass protocol flags to ssh1connection */
void ssh1_connection_set_protoflags(
PacketProtocolLayer *ppl, int local, int remote);
/* Shared get_specials method between the two ssh1 layers */
bool ssh1_common_get_specials(PacketProtocolLayer *, add_special_fn_t, void *);
/* Other shared functions between ssh1 layers */
bool ssh1_common_filter_queue(PacketProtocolLayer *ppl);
void ssh1_compute_session_id(
unsigned char *session_id, const unsigned char *cookie,
RSAKey *hostkey, RSAKey *servkey);
/* Method used by the SSH server */
void ssh2_transport_provide_hostkeys(PacketProtocolLayer *ssh2_transport_ptr,
ssh_key *const *hostkeys, int nhostkeys);
#endif /* PUTTY_SSHPPL_H */