/* $OpenBSD: channels.h,v 1.120 2016/10/18 17:32:54 dtucker Exp $ */ /* * 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) 1999, 2000, 2001, 2002 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. */ #ifndef CHANNEL_H #define CHANNEL_H /* Definitions for channel types. */ #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_DYNAMIC 13 #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */ #define SSH_CHANNEL_MUX_LISTENER 15 /* Listener for mux conn. */ #define SSH_CHANNEL_MUX_CLIENT 16 /* Conn. to mux slave */ #define SSH_CHANNEL_ABANDONED 17 /* Abandoned session, eg mux */ #define SSH_CHANNEL_UNIX_LISTENER 18 /* Listening on a domain socket. */ #define SSH_CHANNEL_RUNIX_LISTENER 19 /* Listening to a R-style domain socket. */ #define SSH_CHANNEL_MUX_PROXY 20 /* proxy channel for mux-slave */ #define SSH_CHANNEL_MAX_TYPE 21 #define CHANNEL_CANCEL_PORT_STATIC -1 struct Channel; typedef struct Channel Channel; typedef void channel_open_fn(int, int, void *); typedef void channel_callback_fn(int, void *); typedef int channel_infilter_fn(struct Channel *, char *, int); typedef void channel_filter_cleanup_fn(int, void *); typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); /* Channel success/failure callbacks */ typedef void channel_confirm_cb(int, struct Channel *, void *); typedef void channel_confirm_abandon_cb(struct Channel *, void *); struct channel_confirm { TAILQ_ENTRY(channel_confirm) entry; channel_confirm_cb *cb; channel_confirm_abandon_cb *abandon_cb; void *ctx; }; TAILQ_HEAD(channel_confirms, channel_confirm); /* Context for non-blocking connects */ struct channel_connect { char *host; int port; struct addrinfo *ai, *aitop; }; /* Callbacks for mux channels back into client-specific code */ typedef int mux_callback_fn(struct Channel *); struct Channel { int type; /* channel type/state */ int self; /* my own channel identifier */ int remote_id; /* channel identifier for remote peer */ u_int istate; /* input from channel (state of receive half) */ u_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 */ int ctl_chan; /* control channel (multiplexed connections) */ int isatty; /* rfd is a tty */ int client_tty; /* (client) TTY has been requested */ int force_drain; /* force close on iEOF */ time_t notbefore; /* Pause IO until deadline (time_t) */ int delayed; /* post-select handlers for newly created * channels are delayed until the first call * to a matching pre-select handler. * this way post-select handlers are not * accidentally called if a FD gets reused */ 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; /* path for unix domain sockets, or host name for forwards */ int listening_port; /* port being listened for forwards */ char *listening_addr; /* addr being listened for forwards */ int host_port; /* remote port to connect for forwards */ char *remote_name; /* remote hostname */ u_int remote_window; u_int remote_maxpacket; u_int local_window; u_int local_window_max; u_int local_consumed; u_int local_maxpacket; int extended_usage; int single_connection; char *ctype; /* type */ /* callback */ channel_open_fn *open_confirm; void *open_confirm_ctx; channel_callback_fn *detach_user; int detach_close; struct channel_confirms status_confirms; /* filter */ channel_infilter_fn *input_filter; channel_outfilter_fn *output_filter; void *filter_ctx; channel_filter_cleanup_fn *filter_cleanup; /* keep boundaries */ int datagram; /* non-blocking connect */ struct channel_connect connect_ctx; /* multiplexing protocol hook, called for each packet received */ mux_callback_fn *mux_rcb; void *mux_ctx; int mux_pause; int mux_downstream_id; }; #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_PACKET_DEFAULT (32*1024) #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) #define CHAN_TCP_PACKET_DEFAULT (32*1024) #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) #define CHAN_X11_PACKET_DEFAULT (16*1024) #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) /* possible input states */ #define CHAN_INPUT_OPEN 0 #define CHAN_INPUT_WAIT_DRAIN 1 #define CHAN_INPUT_WAIT_OCLOSE 2 #define CHAN_INPUT_CLOSED 3 /* possible output states */ #define CHAN_OUTPUT_OPEN 0 #define CHAN_OUTPUT_WAIT_DRAIN 1 #define CHAN_OUTPUT_WAIT_IEOF 2 #define CHAN_OUTPUT_CLOSED 3 #define CHAN_CLOSE_SENT 0x01 #define CHAN_CLOSE_RCVD 0x02 #define CHAN_EOF_SENT 0x04 #define CHAN_EOF_RCVD 0x08 #define CHAN_LOCAL 0x10 #define CHAN_RBUF 16*1024 /* check whether 'efd' is still in use */ #define CHANNEL_EFD_INPUT_ACTIVE(c) \ (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ (c->efd != -1 || \ buffer_len(&c->extended) > 0)) #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ buffer_len(&c->extended) > 0)) /* channel management */ Channel *channel_by_id(int); Channel *channel_by_remote_id(int); Channel *channel_lookup(int); Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); void channel_set_fds(int, int, int, int, int, int, int, u_int); void channel_free(Channel *); void channel_free_all(void); void channel_stop_listening(void); void channel_send_open(int); void channel_request_start(int, char *, int); void channel_register_cleanup(int, channel_callback_fn *, int); void channel_register_open_confirm(int, channel_open_fn *, void *); void channel_register_filter(int, channel_infilter_fn *, channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); void channel_register_status_confirm(int, channel_confirm_cb *, channel_confirm_abandon_cb *, void *); void channel_cancel_cleanup(int); int channel_close_fd(int *); void channel_send_window_changes(void); /* mux proxy support */ int channel_proxy_downstream(Channel *mc); int channel_proxy_upstream(Channel *, int, u_int32_t, void *); /* protocol handler */ int channel_input_close(int, u_int32_t, void *); int channel_input_close_confirmation(int, u_int32_t, void *); int channel_input_data(int, u_int32_t, void *); int channel_input_extended_data(int, u_int32_t, void *); int channel_input_ieof(int, u_int32_t, void *); int channel_input_oclose(int, u_int32_t, void *); int channel_input_open_confirmation(int, u_int32_t, void *); int channel_input_open_failure(int, u_int32_t, void *); int channel_input_port_open(int, u_int32_t, void *); int channel_input_window_adjust(int, u_int32_t, void *); int channel_input_status_confirm(int, u_int32_t, void *); /* file descriptor handling (read/write) */ void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, time_t*, int); void channel_after_select(fd_set *, fd_set *); void channel_output_poll(void); int channel_not_very_much_buffered_data(void); void channel_close_all(void); int channel_still_open(void); char *channel_open_message(void); int channel_find_open(void); /* tcp forwarding */ struct Forward; struct ForwardOptions; void channel_set_af(int af); void channel_permit_all_opens(void); void channel_add_permitted_opens(char *, int); int channel_add_adm_permitted_opens(char *, int); void channel_disable_adm_local_opens(void); void channel_update_permitted_opens(int, int); void channel_clear_permitted_opens(void); void channel_clear_adm_permitted_opens(void); void channel_print_adm_permitted_opens(void); Channel *channel_connect_to_port(const char *, u_short, char *, char *); Channel *channel_connect_to_path(const char *, char *, char *); Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); Channel *channel_connect_by_listen_address(const char *, u_short, char *, char *); Channel *channel_connect_by_listen_path(const char *, char *, char *); int channel_request_remote_forwarding(struct Forward *); int channel_setup_local_fwd_listener(struct Forward *, struct ForwardOptions *); int channel_request_rforward_cancel(struct Forward *); int channel_setup_remote_fwd_listener(struct Forward *, int *, struct ForwardOptions *); int channel_cancel_rport_listener(struct Forward *); int channel_cancel_lport_listener(struct Forward *, int, struct ForwardOptions *); int permitopen_port(const char *); /* x11 forwarding */ void channel_set_x11_refuse_time(u_int); int x11_connect_display(void); int x11_create_display_inet(int, int, int, u_int *, int **); int x11_input_open(int, u_int32_t, void *); void x11_request_forwarding_with_spoofing(int, const char *, const char *, const char *, int); int deny_input_open(int, u_int32_t, void *); /* agent forwarding */ void auth_request_forwarding(void); /* channel close */ int chan_is_dead(Channel *, int); void chan_mark_dead(Channel *); /* channel events */ void chan_rcvd_oclose(Channel *); void chan_rcvd_eow(Channel *); /* SSH2-only */ void chan_read_failed(Channel *); void chan_ibuf_empty(Channel *); void chan_rcvd_ieof(Channel *); void chan_write_failed(Channel *); void chan_obuf_empty(Channel *); #endif