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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 _CHANNEL_H_
#define _CHANNEL_H_
#include "includes.h"
#include "buffer.h"
#include "circbuffer.h"
/* channel->type values */
#define CHANNEL_ID_NONE 0
#define CHANNEL_ID_SESSION 1
#define CHANNEL_ID_X11 2
#define CHANNEL_ID_AGENT 3
#define CHANNEL_ID_TCPDIRECT 4
#define CHANNEL_ID_TCPFORWARDED 5
#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 MAX_CHANNELS 100 /* simple mem restriction, includes each tcp/x11
connection, so can't be _too_ small */
#define CHAN_EXTEND_SIZE 3 /* how many extra slots to add when we need more */
#define RECV_MAXWINDOW 8000 /* tweak */
#define RECV_WINDOWEXTEND 1000 /* We send a "window extend" every
RECV_WINDOWEXTEND bytes */
#define RECV_MAXPACKET RECV_MAXWINDOW /* tweak */
struct ChanType;
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 size, 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 */
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;
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). */
const struct ChanType* type;
};
struct ChanType {
int sepfds; /* Whether this channel has seperate pipes for in/out or not */
char *name;
int (*inithandler)(struct Channel*);
int (*check_close)(struct Channel*);
void (*reqhandler)(struct Channel*);
void (*closehandler)(struct Channel*);
};
void chaninitialise(const struct ChanType *chantypes[]);
void chancleanup();
void setchannelfds(fd_set *readfd, fd_set *writefd);
void channelio(fd_set *readfd, fd_set *writefd);
struct Channel* getchannel();
struct Channel* newchannel(unsigned int remotechan,
const struct ChanType *type,
unsigned int transwindow, unsigned int transmaxpacket);
void recv_msg_channel_open();
void recv_msg_channel_request();
void send_msg_channel_failure(struct Channel *channel);
void send_msg_channel_success(struct Channel *channel);
void recv_msg_channel_data();
void recv_msg_channel_extended_data();
void recv_msg_channel_window_adjust();
void recv_msg_channel_close();
void recv_msg_channel_eof();
void common_recv_msg_channel_data(struct Channel *channel, int fd,
circbuffer * buf);
#ifdef DROPBEAR_CLIENT
extern const struct ChanType clichansess;
#endif
#if defined(USING_LISTENERS) || defined(DROPBEAR_CLIENT)
int send_msg_channel_open_init(int fd, const struct ChanType *type);
void recv_msg_channel_open_confirmation();
void recv_msg_channel_open_failure();
#endif
#endif /* _CHANNEL_H_ */
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