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Diffstat (limited to 'crypto/openssh/channels.h')
| -rw-r--r-- | crypto/openssh/channels.h | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/crypto/openssh/channels.h b/crypto/openssh/channels.h new file mode 100644 index 0000000..0052686 --- /dev/null +++ b/crypto/openssh/channels.h @@ -0,0 +1,293 @@ +/* + * Author: Tatu Ylonen <ylo@cs.hut.fi> + * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland + * All rights reserved + * + * As far as I am concerned, the code I have written for this software + * can be used freely for any purpose. Any derived versions of this + * software must be clearly marked as such, and if the derived work is + * incompatible with the protocol description in the RFC file, it must be + * called by a name other than "ssh" or "Secure Shell". + */ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +/* RCSID("$OpenBSD: channels.h,v 1.22 2000/10/27 07:48:22 markus Exp $"); */ + +#ifndef CHANNELS_H +#define CHANNELS_H + +/* Definitions for channel types. */ +#define SSH_CHANNEL_FREE 0 /* This channel is free (unused). */ +#define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */ +#define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */ +#define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */ +#define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */ +#define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */ +#define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */ +#define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */ +#define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */ +#define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */ +#define SSH_CHANNEL_LARVAL 10 /* larval session */ +#define SSH_CHANNEL_MAX_TYPE 11 + +/* + * Data structure for channel data. This is iniailized in channel_allocate + * and cleared in channel_free. + */ +struct Channel; +typedef struct Channel Channel; + +typedef void channel_callback_fn(int id, void *arg); +typedef int channel_filter_fn(struct Channel *c, char *buf, int len); + +struct Channel { + int type; /* channel type/state */ + int self; /* my own channel identifier */ + int remote_id; /* channel identifier for remote peer */ + /* peer can be reached over encrypted connection, via packet-sent */ + int istate; /* input from channel (state of receive half) */ + int ostate; /* output to channel (state of transmit half) */ + int flags; /* close sent/rcvd */ + int rfd; /* read fd */ + int wfd; /* write fd */ + int efd; /* extended fd */ + int sock; /* sock fd */ + Buffer input; /* data read from socket, to be sent over + * encrypted connection */ + Buffer output; /* data received over encrypted connection for + * send on socket */ + Buffer extended; + char path[200]; /* path for unix domain sockets, or host name + * for forwards */ + int listening_port; /* port being listened for forwards */ + int host_port; /* remote port to connect for forwards */ + char *remote_name; /* remote hostname */ + + int remote_window; + int remote_maxpacket; + int local_window; + int local_window_max; + int local_consumed; + int local_maxpacket; + int extended_usage; + + char *ctype; /* type */ + + /* callback */ + channel_callback_fn *cb_fn; + void *cb_arg; + int cb_event; + channel_callback_fn *dettach_user; + + /* filter */ + channel_filter_fn *input_filter; +}; + +#define CHAN_EXTENDED_IGNORE 0 +#define CHAN_EXTENDED_READ 1 +#define CHAN_EXTENDED_WRITE 2 + +/* default window/packet sizes for tcp/x11-fwd-channel */ +#define CHAN_SES_WINDOW_DEFAULT (32*1024) +#define CHAN_SES_PACKET_DEFAULT (CHAN_SES_WINDOW_DEFAULT/2) +#define CHAN_TCP_WINDOW_DEFAULT (32*1024) +#define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2) +#define CHAN_X11_WINDOW_DEFAULT (4*1024) +#define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2) + + +void channel_open(int id); +void channel_request(int id, char *service, int wantconfirm); +void channel_request_start(int id, char *service, int wantconfirm); +void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg); +void channel_register_cleanup(int id, channel_callback_fn *fn); +void channel_register_filter(int id, channel_filter_fn *fn); +void channel_cancel_cleanup(int id); +Channel *channel_lookup(int id); + +int +channel_new(char *ctype, int type, int rfd, int wfd, int efd, + int window, int maxpack, int extended_usage, char *remote_name, + int nonblock); +void +channel_set_fds(int id, int rfd, int wfd, int efd, + int extusage, int nonblock); + +void deny_input_open(int type, int plen, void *ctxt); + +void channel_input_channel_request(int type, int plen, void *ctxt); +void channel_input_close(int type, int plen, void *ctxt); +void channel_input_close_confirmation(int type, int plen, void *ctxt); +void channel_input_data(int type, int plen, void *ctxt); +void channel_input_extended_data(int type, int plen, void *ctxt); +void channel_input_ieof(int type, int plen, void *ctxt); +void channel_input_oclose(int type, int plen, void *ctxt); +void channel_input_open_confirmation(int type, int plen, void *ctxt); +void channel_input_open_failure(int type, int plen, void *ctxt); +void channel_input_port_open(int type, int plen, void *ctxt); +void channel_input_window_adjust(int type, int plen, void *ctxt); +void channel_input_open(int type, int plen, void *ctxt); + +/* Sets specific protocol options. */ +void channel_set_options(int hostname_in_open); + +/* + * Allocate a new channel object and set its type and socket. Remote_name + * must have been allocated with xmalloc; this will free it when the channel + * is freed. + */ +int channel_allocate(int type, int sock, char *remote_name); + +/* Free the channel and close its socket. */ +void channel_free(int channel); + +/* Add any bits relevant to channels in select bitmasks. */ +void channel_prepare_select(fd_set * readset, fd_set * writeset); + +/* + * After select, perform any appropriate operations for channels which have + * events pending. + */ +void channel_after_select(fd_set * readset, fd_set * writeset); + +/* If there is data to send to the connection, send some of it now. */ +void channel_output_poll(void); + +/* Returns true if no channel has too much buffered data. */ +int channel_not_very_much_buffered_data(void); + +/* This closes any sockets that are listening for connections; this removes + any unix domain sockets. */ +void channel_stop_listening(void); + +/* + * Closes the sockets of all channels. This is used to close extra file + * descriptors after a fork. + */ +void channel_close_all(void); + +/* Returns the maximum file descriptor number used by the channels. */ +int channel_max_fd(void); + +/* Returns true if there is still an open channel over the connection. */ +int channel_still_open(void); + +/* + * Returns a string containing a list of all open channels. The list is + * suitable for displaying to the user. It uses crlf instead of newlines. + * The caller should free the string with xfree. + */ +char *channel_open_message(void); + +/* + * Initiate forwarding of connections to local port "port" through the secure + * channel to host:port from remote side. This never returns if there was an + * error. + */ +void +channel_request_local_forwarding(u_short port, const char *host, + u_short remote_port, int gateway_ports); + +/* + * Initiate forwarding of connections to port "port" on remote host through + * the secure channel to host:port from local side. This never returns if + * there was an error. This registers that open requests for that port are + * permitted. + */ +void +channel_request_remote_forwarding(u_short port, const char *host, + u_short remote_port); + +/* + * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually + * called by the server, because the user could connect to any port anyway, + * and the server has no way to know but to trust the client anyway. + */ +void channel_permit_all_opens(void); + +/* + * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates + * listening for the port, and sends back a success reply (or disconnect + * message if there was an error). This never returns if there was an error. + */ +void channel_input_port_forward_request(int is_root, int gateway_ports); + +/* + * Creates a port for X11 connections, and starts listening for it. Returns + * the display name, or NULL if an error was encountered. + */ +char *x11_create_display(int screen); + +/* + * Creates an internet domain socket for listening for X11 connections. + * Returns a suitable value for the DISPLAY variable, or NULL if an error + * occurs. + */ +char *x11_create_display_inet(int screen, int x11_display_offset); + +/* + * This is called when SSH_SMSG_X11_OPEN is received. The packet contains + * the remote channel number. We should do whatever we want, and respond + * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. + */ +void x11_input_open(int type, int plen, void *ctxt); + +/* + * Requests forwarding of X11 connections. This should be called on the + * client only. + */ +void x11_request_forwarding(void); + +/* + * Requests forwarding for X11 connections, with authentication spoofing. + * This should be called in the client only. + */ +void +x11_request_forwarding_with_spoofing(int client_session_id, + const char *proto, const char *data); + +/* Sends a message to the server to request authentication fd forwarding. */ +void auth_request_forwarding(void); + +/* + * Returns the name of the forwarded authentication socket. Returns NULL if + * there is no forwarded authentication socket. The returned value points to + * a static buffer. + */ +char *auth_get_socket_name(void); + +/* + * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. + * This starts forwarding authentication requests. + */ +int auth_input_request_forwarding(struct passwd * pw); + +/* This is called to process an SSH_SMSG_AGENT_OPEN message. */ +void auth_input_open_request(int type, int plen, void *ctxt); + +/* XXX */ +int channel_connect_to(const char *host, u_short host_port); +int x11_connect_display(void); + +#endif |
