X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/6ae2364d36eaebbbc830a417d5a01ebf3cc84e5f..HEAD:/channels.h diff --git a/channels.h b/channels.h index 9d98d04d..cc71885f 100644 --- a/channels.h +++ b/channels.h @@ -1,10 +1,44 @@ -/* RCSID("$Id$"); */ +/* $OpenBSD: channels.h,v 1.103 2010/01/26 01:28:35 djm Exp $ */ -#ifndef CHANNELS_H -#define CHANNELS_H +/* + * 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_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 */ @@ -15,220 +49,247 @@ #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. - */ -typedef void channel_callback_fn(int id, void *arg); - -typedef struct Channel { +#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_MAX_TYPE 17 + +struct Channel; +typedef struct Channel Channel; + +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 */ - /* 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) */ + 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 wfd_isatty; /* wfd is a tty */ + int client_tty; /* (client) TTY has been requested */ + int force_drain; /* force close on iEOF */ + 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 + * accidenly 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[200]; /* path for unix domain sockets, or host name - * for forwards */ + char *path; + /* 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; + 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_callback_fn *cb_fn; - void *cb_arg; - int cb_event; - channel_callback_fn *dettach_user; -} Channel; - -#define CHAN_EXTENDED_IGNORE 0 -#define CHAN_EXTENDED_READ 1 -#define CHAN_EXTENDED_WRITE 2 - -void channel_set_fds(int id, int rfd, int wfd, int efd, int extusage); -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_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); - -void channel_input_channel_request(int type, int plen); -void channel_input_close(int type, int plen); -void channel_input_close_confirmation(int type, int plen); -void channel_input_data(int type, int plen); -void channel_input_extended_data(int type, int plen); -void channel_input_ieof(int type, int plen); -void channel_input_oclose(int type, int plen); -void channel_input_open_confirmation(int type, int plen); -void channel_input_open_failure(int type, int plen); -void channel_input_port_open(int type, int plen); -void channel_input_window_adjust(int type, int plen); -void channel_input_open(int type, int plen); - -/* 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); + /* callback */ + channel_callback_fn *open_confirm; + void *open_confirm_ctx; + channel_callback_fn *detach_user; + int detach_close; + struct channel_confirms status_confirms; -/* - * 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); + /* filter */ + channel_infilter_fn *input_filter; + channel_outfilter_fn *output_filter; + void *filter_ctx; + channel_filter_cleanup_fn *filter_cleanup; -/* - * 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); + /* keep boundaries */ + int datagram; -/* - * 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); + /* non-blocking connect */ + struct channel_connect connect_ctx; -/* - * 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); + /* multiplexing protocol hook, called for each packet received */ + mux_callback_fn *mux_rcb; + void *mux_ctx; +}; -/* - * 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(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 if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. - * This starts forwarding authentication requests. - */ -void 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); +#define CHAN_EXTENDED_IGNORE 0 +#define CHAN_EXTENDED_READ 1 +#define CHAN_EXTENDED_WRITE 2 -/* XXX */ -int channel_connect_to(const char *host, u_short host_port); +/* 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_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_callback_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); + +/* protocol handler */ + +void channel_input_close(int, u_int32_t, void *); +void channel_input_close_confirmation(int, u_int32_t, void *); +void channel_input_data(int, u_int32_t, void *); +void channel_input_extended_data(int, u_int32_t, void *); +void channel_input_ieof(int, u_int32_t, void *); +void channel_input_oclose(int, u_int32_t, void *); +void channel_input_open_confirmation(int, u_int32_t, void *); +void channel_input_open_failure(int, u_int32_t, void *); +void channel_input_port_open(int, u_int32_t, void *); +void channel_input_window_adjust(int, u_int32_t, void *); +void 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*, 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 */ +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_clear_permitted_opens(void); +void channel_clear_adm_permitted_opens(void); +void channel_print_adm_permitted_opens(void); +int channel_input_port_forward_request(int, int); +Channel *channel_connect_to(const char *, u_short, char *, char *); +Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); +Channel *channel_connect_by_listen_address(u_short, char *, char *); +int channel_request_remote_forwarding(const char *, u_short, + const char *, u_short); +int channel_setup_local_fwd_listener(const char *, u_short, + const char *, u_short, int); +void channel_request_rforward_cancel(const char *host, u_short port); +int channel_setup_remote_fwd_listener(const char *, u_short, int *, int); +int channel_cancel_rport_listener(const char *, u_short); + +/* x11 forwarding */ + +int x11_connect_display(void); +int x11_create_display_inet(int, int, int, u_int *, int **); +void x11_input_open(int, u_int32_t, void *); +void x11_request_forwarding_with_spoofing(int, const char *, const char *, + const char *); +void 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