/* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , 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 1.26 2001/01/31 20:37:23 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_RPORT_LISTENER 11 /* Listening to a R-style port */ #define SSH_CHANNEL_CONNECTING 12 #define SSH_CHANNEL_MAX_TYPE 13 /* * 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); /* 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); /* * Allocate/update select bitmasks and add any bits relevant to channels in * select bitmasks. */ void channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp); /* * 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 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. */ int channel_request_local_forwarding(u_short listen_port, const char *host_to_connect, u_short port_to_connect, int gateway_ports); int channel_request_forwarding(const char *listen_address, u_short listen_port, const char *host_to_connect, u_short port_to_connect, int gateway_ports, int remote_fwd); /* * 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 channel_connect_by_listen_adress(u_short listen_port); int x11_connect_display(void); #endif