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      1 /*
      2  * Author: Tatu Ylonen <ylo (at) cs.hut.fi>
      3  * Copyright (c) 1995 Tatu Ylonen <ylo (at) cs.hut.fi>, Espoo, Finland
      4  *                    All rights reserved
      5  *
      6  * As far as I am concerned, the code I have written for this software
      7  * can be used freely for any purpose.  Any derived versions of this
      8  * software must be clearly marked as such, and if the derived work is
      9  * incompatible with the protocol description in the RFC file, it must be
     10  * called by a name other than "ssh" or "Secure Shell".
     11  */
     12 /*
     13  * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
     14  *
     15  * Redistribution and use in source and binary forms, with or without
     16  * modification, are permitted provided that the following conditions
     17  * are met:
     18  * 1. Redistributions of source code must retain the above copyright
     19  *    notice, this list of conditions and the following disclaimer.
     20  * 2. Redistributions in binary form must reproduce the above copyright
     21  *    notice, this list of conditions and the following disclaimer in the
     22  *    documentation and/or other materials provided with the distribution.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     30  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     33  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     34  */
     35 /*
     36  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
     37  * Use is subject to license terms.
     38  */
     39 /*	$OpenBSD: channels.h,v 1.70 2002/06/24 14:33:27 markus Exp $	*/
     40 
     41 
     42 #ifndef	_CHANNELS_H
     43 #define	_CHANNELS_H
     44 
     45 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     46 
     47 #ifdef __cplusplus
     48 extern "C" {
     49 #endif
     50 
     51 #include "buffer.h"
     52 
     53 /* Definitions for channel types. */
     54 #define SSH_CHANNEL_X11_LISTENER	1	/* Listening for inet X11 conn. */
     55 #define SSH_CHANNEL_PORT_LISTENER	2	/* Listening on a port. */
     56 #define SSH_CHANNEL_OPENING		3	/* waiting for confirmation */
     57 #define SSH_CHANNEL_OPEN		4	/* normal open two-way channel */
     58 #define SSH_CHANNEL_CLOSED		5	/* waiting for close confirmation */
     59 #define SSH_CHANNEL_AUTH_SOCKET		6	/* authentication socket */
     60 #define SSH_CHANNEL_X11_OPEN		7	/* reading first X11 packet */
     61 #define SSH_CHANNEL_INPUT_DRAINING	8	/* sending remaining data to conn */
     62 #define SSH_CHANNEL_OUTPUT_DRAINING	9	/* sending remaining data to app */
     63 #define SSH_CHANNEL_LARVAL		10	/* larval session */
     64 #define SSH_CHANNEL_RPORT_LISTENER	11	/* Listening to a R-style port  */
     65 #define SSH_CHANNEL_CONNECTING		12
     66 #define SSH_CHANNEL_DYNAMIC		13
     67 #define SSH_CHANNEL_ZOMBIE		14	/* Almost dead. */
     68 #define SSH_CHANNEL_MAX_TYPE		15
     69 
     70 #define SSH_CHANNEL_PATH_LEN		256
     71 
     72 struct Channel;
     73 typedef struct Channel Channel;
     74 
     75 typedef void channel_callback_fn(int, void *);
     76 typedef int channel_filter_fn(struct Channel *, char *, int);
     77 
     78 struct Channel {
     79 	int     type;		/* channel type/state */
     80 	int     self;		/* my own channel identifier */
     81 	int     remote_id;	/* channel identifier for remote peer */
     82 	u_int   istate;		/* input from channel (state of receive half) */
     83 	u_int   ostate;		/* output to channel  (state of transmit half) */
     84 	int	wait_for_exit;	/* no close till after exit-status is sent */
     85 	int     flags;		/* close sent/rcvd */
     86 	int     rfd;		/* read fd */
     87 	int     wfd;		/* write fd */
     88 	int     efd;		/* extended fd */
     89 	int     sock;		/* sock fd */
     90 	int     isatty;		/* rfd is a tty */
     91 	int     wfd_isatty;	/* wfd is a tty */
     92 	int     force_drain;	/* force close on iEOF */
     93 	int     delayed;		/* fdset hack */
     94 	Buffer  input;		/* data read from socket, to be sent over
     95 				 * encrypted connection */
     96 	Buffer  output;		/* data received over encrypted connection for
     97 				 * send on socket */
     98 	Buffer  extended;
     99 	char    path[SSH_CHANNEL_PATH_LEN];
    100 		/* path for unix domain sockets, or host name for forwards */
    101 	int     listening_port;	/* port being listened for forwards */
    102 	int     host_port;	/* remote port to connect for forwards */
    103 	char   *remote_name;	/* remote hostname */
    104 
    105 	u_int	remote_window;
    106 	u_int	remote_maxpacket;
    107 	u_int	local_window;
    108 	u_int	local_window_max;
    109 	u_int	local_consumed;
    110 	u_int	local_maxpacket;
    111 	int     extended_usage;
    112 	int	single_connection;
    113 
    114 	char   *ctype;		/* type */
    115 
    116 	/* callback */
    117 	channel_callback_fn	*confirm;
    118 	channel_callback_fn	*detach_user;
    119 
    120 	/* filter */
    121 	channel_filter_fn	*input_filter;
    122 };
    123 
    124 #define CHAN_EXTENDED_IGNORE		0
    125 #define CHAN_EXTENDED_READ		1
    126 #define CHAN_EXTENDED_WRITE		2
    127 
    128 /* default window/packet sizes for tcp/x11-fwd-channel */
    129 #define CHAN_SES_PACKET_DEFAULT	(32*1024)
    130 #define CHAN_SES_WINDOW_DEFAULT	(4*CHAN_SES_PACKET_DEFAULT)
    131 #define CHAN_TCP_PACKET_DEFAULT	(32*1024)
    132 #define CHAN_TCP_WINDOW_DEFAULT	(4*CHAN_TCP_PACKET_DEFAULT)
    133 #define CHAN_X11_PACKET_DEFAULT	(16*1024)
    134 #define CHAN_X11_WINDOW_DEFAULT	(4*CHAN_X11_PACKET_DEFAULT)
    135 
    136 /* possible input states */
    137 #define CHAN_INPUT_OPEN			0
    138 #define CHAN_INPUT_WAIT_DRAIN		1
    139 #define CHAN_INPUT_WAIT_OCLOSE		2
    140 #define CHAN_INPUT_CLOSED		3
    141 
    142 /* possible output states */
    143 #define CHAN_OUTPUT_OPEN		0
    144 #define CHAN_OUTPUT_WAIT_DRAIN		1
    145 #define CHAN_OUTPUT_WAIT_IEOF		2
    146 #define CHAN_OUTPUT_CLOSED		3
    147 
    148 /*
    149  * Other channel flag bits are specific to each type of channel and are
    150  * defined locally with the code that uses them.
    151  */
    152 #define CHAN_CLOSE_SENT			0x01
    153 #define CHAN_CLOSE_RCVD			0x02
    154 #define CHAN_EOF_SENT			0x04
    155 #define CHAN_EOF_RCVD			0x08
    156 
    157 /* check whether 'efd' is still in use */
    158 #define CHANNEL_EFD_INPUT_ACTIVE(c) \
    159 	(compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
    160 	(c->efd != -1 || \
    161 	buffer_len(&c->extended) > 0))
    162 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
    163 	(compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
    164 	((c->efd != -1 && !(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD))) || \
    165 	buffer_len(&c->extended) > 0))
    166 
    167 /* channel management */
    168 
    169 Channel	*channel_lookup(int);
    170 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int);
    171 void	 channel_set_fds(int, int, int, int, int, int, u_int);
    172 void	 channel_set_wait_for_exit(int, int);
    173 void	 channel_free(Channel *);
    174 void	 channel_free_all(void);
    175 void	 channel_stop_listening(void);
    176 
    177 void	 channel_send_open(int);
    178 void	 channel_request_start(int, char *, int);
    179 void	 channel_register_cleanup(int, channel_callback_fn *);
    180 void	 channel_register_confirm(int, channel_callback_fn *);
    181 void	 channel_register_filter(int, channel_filter_fn *);
    182 void	 channel_cancel_cleanup(int);
    183 int	 channel_close_fd(int *);
    184 
    185 /* protocol handler */
    186 
    187 void	 channel_input_close(int, u_int32_t, void *);
    188 void	 channel_input_close_confirmation(int, u_int32_t, void *);
    189 void	 channel_input_data(int, u_int32_t, void *);
    190 void	 channel_input_extended_data(int, u_int32_t, void *);
    191 void	 channel_input_ieof(int, u_int32_t, void *);
    192 void	 channel_input_oclose(int, u_int32_t, void *);
    193 void	 channel_input_open_confirmation(int, u_int32_t, void *);
    194 void	 channel_input_open_failure(int, u_int32_t, void *);
    195 void	 channel_input_port_open(int, u_int32_t, void *);
    196 void	 channel_input_window_adjust(int, u_int32_t, void *);
    197 
    198 /* file descriptor handling (read/write) */
    199 
    200 void	 channel_prepare_select(fd_set **, fd_set **, int *, int*, int);
    201 void     channel_after_select(fd_set *, fd_set *);
    202 void     channel_output_poll(void);
    203 
    204 int      channel_not_very_much_buffered_data(void);
    205 void     channel_close_all(void);
    206 int      channel_still_open(void);
    207 char	*channel_open_message(void);
    208 int	 channel_find_open(void);
    209 
    210 /* tcp forwarding */
    211 void	 channel_set_af(int af);
    212 void     channel_permit_all_opens(void);
    213 void	 channel_add_permitted_opens(char *, int);
    214 void	 channel_clear_permitted_opens(void);
    215 void     channel_input_port_forward_request(int, int);
    216 int	 channel_connect_to(const char *, u_short);
    217 int	 channel_connect_by_listen_address(u_short);
    218 int	 channel_request_remote_forwarding(const char *, u_short,
    219 	     const char *, u_short);
    220 int	 channel_setup_local_fwd_listener(const char *, u_short,
    221 	     const char *, u_short, int);
    222 void	 channel_request_rforward_cancel(const char *host, u_short port);
    223 int	 channel_setup_remote_fwd_listener(const char *, u_short, int);
    224 int	 channel_cancel_rport_listener(const char *, u_short);
    225 
    226 /* x11 forwarding */
    227 
    228 int	 x11_connect_display(void);
    229 int	 x11_create_display_inet(int, int, int, u_int *);
    230 void     x11_input_open(int, u_int32_t, void *);
    231 void	 x11_request_forwarding_with_spoofing(int, const char *, const char *,
    232 	     const char *);
    233 void	 deny_input_open(int, u_int32_t, void *);
    234 
    235 /* agent forwarding */
    236 
    237 void	 auth_request_forwarding(void);
    238 void	 auth_input_open_request(int, u_int32_t, void *);
    239 
    240 /* channel close */
    241 
    242 int	 chan_is_dead(Channel *, int);
    243 void	 chan_mark_dead(Channel *);
    244 
    245 /* channel events */
    246 
    247 void	 chan_rcvd_oclose(Channel *);
    248 void	 chan_read_failed(Channel *);
    249 void	 chan_ibuf_empty(Channel *);
    250 
    251 void	 chan_rcvd_ieof(Channel *);
    252 void	 chan_write_failed(Channel *);
    253 void	 chan_obuf_empty(Channel *);
    254 
    255 #ifdef __cplusplus
    256 }
    257 #endif
    258 
    259 #endif /* _CHANNELS_H */
    260