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/*
* Dropbear - a SSH2 server
*
* Copyright (c) 2002,2003 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
#ifndef DROPBEAR_CHANNEL_H_
#define DROPBEAR_CHANNEL_H_
#include "includes.h"
#include "buffer.h"
#include "circbuffer.h"
#define SSH_OPEN_ADMINISTRATIVELY_PROHIBITED 1
#define SSH_OPEN_CONNECT_FAILED 2
#define SSH_OPEN_UNKNOWN_CHANNEL_TYPE 3
#define SSH_OPEN_RESOURCE_SHORTAGE 4
/* Not a real type */
#define SSH_OPEN_IN_PROGRESS 99
#define CHAN_EXTEND_SIZE 3 /* how many extra slots to add when we need more */
struct ChanType;
enum dropbear_channel_prio {
DROPBEAR_CHANNEL_PRIO_INTERACTIVE, /* pty shell, x11 */
DROPBEAR_CHANNEL_PRIO_UNKNOWABLE, /* tcp - can't know what's being forwarded */
DROPBEAR_CHANNEL_PRIO_BULK, /* the rest - probably scp or something */
DROPBEAR_CHANNEL_PRIO_EARLY, /* channel is still being set up */
};
struct Channel {
unsigned int index; /* the local channel index */
unsigned int remotechan;
unsigned int recvwindow, transwindow;
unsigned int recvdonelen;
unsigned int recvmaxpacket, transmaxpacket;
void* typedata; /* a pointer to type specific data */
int writefd; /* read from wire, written to insecure side */
int readfd; /* read from insecure side, written to wire */
int errfd; /* used like writefd or readfd, depending if it's client or server.
Doesn't exactly belong here, but is cleaner here */
circbuffer *writebuf; /* data from the wire, for local consumption. Can be
initially NULL */
circbuffer *extrabuf; /* extended-data for the program - used like writebuf
but for stderr */
/* whether close/eof messages have been exchanged */
int sent_close, recv_close;
int recv_eof, sent_eof;
/* Set after running the ChanType-specific close hander
* to ensure we don't run it twice (nor type->checkclose()). */
int close_handler_done;
struct dropbear_progress_connection *conn_pending;
int initconn; /* used for TCP forwarding, whether the channel has been
fully initialised */
int await_open; /* flag indicating whether we've sent an open request
for this channel (and are awaiting a confirmation
or failure). */
int flushing;
/* Used by client chansession to handle ~ escaping, NULL ignored otherwise */
void (*read_mangler)(const struct Channel*, const unsigned char* bytes, int *len);
const struct ChanType* type;
enum dropbear_channel_prio prio;
};
struct ChanType {
int sepfds; /* Whether this channel has separate pipes for in/out or not */
char *name;
int (*inithandler)(struct Channel*);
int (*check_close)(struct Channel*);
void (*reqhandler)(struct Channel*);
void (*closehandler)(const struct Channel*);
};
/* Callback for connect_remote */
void channel_connect_done(int result, int sock, void* user_data, const char* errstring);
void chaninitialise(const struct ChanType *chantypes[]);
void chancleanup(void);
void setchannelfds(fd_set *readfds, fd_set *writefds, int allow_reads);
void channelio(const fd_set *readfd, const fd_set *writefd);
struct Channel* getchannel(void);
/* Returns an arbitrary channel that is in a ready state - not
being initialised and no EOF in either direction. NULL if none. */
struct Channel* get_any_ready_channel(void);
void recv_msg_channel_open(void);
void recv_msg_channel_request(void);
void send_msg_channel_failure(const struct Channel *channel);
void send_msg_channel_success(const struct Channel *channel);
void recv_msg_channel_data(void);
void recv_msg_channel_extended_data(void);
void recv_msg_channel_window_adjust(void);
void recv_msg_channel_close(void);
void recv_msg_channel_eof(void);
void common_recv_msg_channel_data(struct Channel *channel, int fd,
circbuffer * buf);
#if DROPBEAR_CLIENT
extern const struct ChanType clichansess;
#endif
#if DROPBEAR_LISTENERS || DROPBEAR_CLIENT
int send_msg_channel_open_init(int fd, const struct ChanType *type);
void recv_msg_channel_open_confirmation(void);
void recv_msg_channel_open_failure(void);
#endif
void start_send_channel_request(const struct Channel *channel, const char *type);
void send_msg_request_success(void);
void send_msg_request_failure(void);
#endif /* DROPBEAR_CHANNEL_H_ */
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