channels.h revision 224638
1/* $OpenBSD: channels.h,v 1.104 2010/05/14 23:29:23 djm Exp $ */ 2/* $FreeBSD$ */ 3 4/* 5 * Author: Tatu Ylonen <ylo@cs.hut.fi> 6 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 7 * All rights reserved 8 * 9 * As far as I am concerned, the code I have written for this software 10 * can be used freely for any purpose. Any derived versions of this 11 * software must be clearly marked as such, and if the derived work is 12 * incompatible with the protocol description in the RFC file, it must be 13 * called by a name other than "ssh" or "Secure Shell". 14 */ 15/* 16 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39#ifndef CHANNEL_H 40#define CHANNEL_H 41 42/* Definitions for channel types. */ 43#define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */ 44#define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */ 45#define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */ 46#define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */ 47#define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */ 48#define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */ 49#define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */ 50#define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */ 51#define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */ 52#define SSH_CHANNEL_LARVAL 10 /* larval session */ 53#define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */ 54#define SSH_CHANNEL_CONNECTING 12 55#define SSH_CHANNEL_DYNAMIC 13 56#define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */ 57#define SSH_CHANNEL_MUX_LISTENER 15 /* Listener for mux conn. */ 58#define SSH_CHANNEL_MUX_CLIENT 16 /* Conn. to mux slave */ 59#define SSH_CHANNEL_MAX_TYPE 17 60 61struct Channel; 62typedef struct Channel Channel; 63 64typedef void channel_open_fn(int, int, void *); 65typedef void channel_callback_fn(int, void *); 66typedef int channel_infilter_fn(struct Channel *, char *, int); 67typedef void channel_filter_cleanup_fn(int, void *); 68typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); 69 70/* Channel success/failure callbacks */ 71typedef void channel_confirm_cb(int, struct Channel *, void *); 72typedef void channel_confirm_abandon_cb(struct Channel *, void *); 73struct channel_confirm { 74 TAILQ_ENTRY(channel_confirm) entry; 75 channel_confirm_cb *cb; 76 channel_confirm_abandon_cb *abandon_cb; 77 void *ctx; 78}; 79TAILQ_HEAD(channel_confirms, channel_confirm); 80 81/* Context for non-blocking connects */ 82struct channel_connect { 83 char *host; 84 int port; 85 struct addrinfo *ai, *aitop; 86}; 87 88/* Callbacks for mux channels back into client-specific code */ 89typedef int mux_callback_fn(struct Channel *); 90 91struct Channel { 92 int type; /* channel type/state */ 93 int self; /* my own channel identifier */ 94 int remote_id; /* channel identifier for remote peer */ 95 u_int istate; /* input from channel (state of receive half) */ 96 u_int ostate; /* output to channel (state of transmit half) */ 97 int flags; /* close sent/rcvd */ 98 int rfd; /* read fd */ 99 int wfd; /* write fd */ 100 int efd; /* extended fd */ 101 int sock; /* sock fd */ 102 int ctl_chan; /* control channel (multiplexed connections) */ 103 int isatty; /* rfd is a tty */ 104 int wfd_isatty; /* wfd is a tty */ 105 int client_tty; /* (client) TTY has been requested */ 106 int force_drain; /* force close on iEOF */ 107 int delayed; /* post-select handlers for newly created 108 * channels are delayed until the first call 109 * to a matching pre-select handler. 110 * this way post-select handlers are not 111 * accidenly called if a FD gets reused */ 112 Buffer input; /* data read from socket, to be sent over 113 * encrypted connection */ 114 Buffer output; /* data received over encrypted connection for 115 * send on socket */ 116 Buffer extended; 117 char *path; 118 /* path for unix domain sockets, or host name for forwards */ 119 int listening_port; /* port being listened for forwards */ 120 int host_port; /* remote port to connect for forwards */ 121 char *remote_name; /* remote hostname */ 122 123 u_int remote_window; 124 u_int remote_maxpacket; 125 u_int local_window; 126 u_int local_window_max; 127 u_int local_consumed; 128 u_int local_maxpacket; 129 u_int tcpwinsz; 130 int dynamic_window; 131 int extended_usage; 132 int single_connection; 133 134 char *ctype; /* type */ 135 136 /* callback */ 137 channel_open_fn *open_confirm; 138 void *open_confirm_ctx; 139 channel_callback_fn *detach_user; 140 int detach_close; 141 struct channel_confirms status_confirms; 142 143 /* filter */ 144 channel_infilter_fn *input_filter; 145 channel_outfilter_fn *output_filter; 146 void *filter_ctx; 147 channel_filter_cleanup_fn *filter_cleanup; 148 149 /* keep boundaries */ 150 int datagram; 151 152 /* non-blocking connect */ 153 struct channel_connect connect_ctx; 154 155 /* multiplexing protocol hook, called for each packet received */ 156 mux_callback_fn *mux_rcb; 157 void *mux_ctx; 158 int mux_pause; 159}; 160 161#define CHAN_EXTENDED_IGNORE 0 162#define CHAN_EXTENDED_READ 1 163#define CHAN_EXTENDED_WRITE 2 164 165/* default window/packet sizes for tcp/x11-fwd-channel */ 166#define CHAN_SES_PACKET_DEFAULT (32*1024) 167#define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) 168 169#define CHAN_TCP_PACKET_DEFAULT (32*1024) 170#define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 171 172#define CHAN_X11_PACKET_DEFAULT (16*1024) 173#define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 174 175#define CHAN_HPN_MIN_WINDOW_DEFAULT (2*1024*1024) 176 177/* possible input states */ 178#define CHAN_INPUT_OPEN 0 179#define CHAN_INPUT_WAIT_DRAIN 1 180#define CHAN_INPUT_WAIT_OCLOSE 2 181#define CHAN_INPUT_CLOSED 3 182 183/* possible output states */ 184#define CHAN_OUTPUT_OPEN 0 185#define CHAN_OUTPUT_WAIT_DRAIN 1 186#define CHAN_OUTPUT_WAIT_IEOF 2 187#define CHAN_OUTPUT_CLOSED 3 188 189#define CHAN_CLOSE_SENT 0x01 190#define CHAN_CLOSE_RCVD 0x02 191#define CHAN_EOF_SENT 0x04 192#define CHAN_EOF_RCVD 0x08 193#define CHAN_LOCAL 0x10 194 195#define CHAN_RBUF 16*1024 196 197/* check whether 'efd' is still in use */ 198#define CHANNEL_EFD_INPUT_ACTIVE(c) \ 199 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 200 (c->efd != -1 || \ 201 buffer_len(&c->extended) > 0)) 202#define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 203 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 204 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 205 buffer_len(&c->extended) > 0)) 206 207/* channel management */ 208 209Channel *channel_by_id(int); 210Channel *channel_lookup(int); 211Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 212void channel_set_fds(int, int, int, int, int, int, int, u_int); 213void channel_free(Channel *); 214void channel_free_all(void); 215void channel_stop_listening(void); 216 217void channel_send_open(int); 218void channel_request_start(int, char *, int); 219void channel_register_cleanup(int, channel_callback_fn *, int); 220void channel_register_open_confirm(int, channel_open_fn *, void *); 221void channel_register_filter(int, channel_infilter_fn *, 222 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 223void channel_register_status_confirm(int, channel_confirm_cb *, 224 channel_confirm_abandon_cb *, void *); 225void channel_cancel_cleanup(int); 226int channel_close_fd(int *); 227void channel_send_window_changes(void); 228 229/* protocol handler */ 230 231void channel_input_close(int, u_int32_t, void *); 232void channel_input_close_confirmation(int, u_int32_t, void *); 233void channel_input_data(int, u_int32_t, void *); 234void channel_input_extended_data(int, u_int32_t, void *); 235void channel_input_ieof(int, u_int32_t, void *); 236void channel_input_oclose(int, u_int32_t, void *); 237void channel_input_open_confirmation(int, u_int32_t, void *); 238void channel_input_open_failure(int, u_int32_t, void *); 239void channel_input_port_open(int, u_int32_t, void *); 240void channel_input_window_adjust(int, u_int32_t, void *); 241void channel_input_status_confirm(int, u_int32_t, void *); 242 243/* file descriptor handling (read/write) */ 244 245void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); 246void channel_after_select(fd_set *, fd_set *); 247void channel_output_poll(void); 248 249int channel_not_very_much_buffered_data(void); 250void channel_close_all(void); 251int channel_still_open(void); 252char *channel_open_message(void); 253int channel_find_open(void); 254 255/* tcp forwarding */ 256void channel_set_af(int af); 257void channel_permit_all_opens(void); 258void channel_add_permitted_opens(char *, int); 259int channel_add_adm_permitted_opens(char *, int); 260void channel_clear_permitted_opens(void); 261void channel_clear_adm_permitted_opens(void); 262void channel_print_adm_permitted_opens(void); 263int channel_input_port_forward_request(int, int); 264Channel *channel_connect_to(const char *, u_short, char *, char *); 265Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); 266Channel *channel_connect_by_listen_address(u_short, char *, char *); 267int channel_request_remote_forwarding(const char *, u_short, 268 const char *, u_short); 269int channel_setup_local_fwd_listener(const char *, u_short, 270 const char *, u_short, int); 271void channel_request_rforward_cancel(const char *host, u_short port); 272int channel_setup_remote_fwd_listener(const char *, u_short, int *, int); 273int channel_cancel_rport_listener(const char *, u_short); 274 275/* x11 forwarding */ 276 277int x11_connect_display(void); 278int x11_create_display_inet(int, int, int, u_int *, int **); 279void x11_input_open(int, u_int32_t, void *); 280void x11_request_forwarding_with_spoofing(int, const char *, const char *, 281 const char *); 282void deny_input_open(int, u_int32_t, void *); 283 284/* agent forwarding */ 285 286void auth_request_forwarding(void); 287 288/* channel close */ 289 290int chan_is_dead(Channel *, int); 291void chan_mark_dead(Channel *); 292 293/* channel events */ 294 295void chan_rcvd_oclose(Channel *); 296void chan_rcvd_eow(Channel *); /* SSH2-only */ 297void chan_read_failed(Channel *); 298void chan_ibuf_empty(Channel *); 299 300void chan_rcvd_ieof(Channel *); 301void chan_write_failed(Channel *); 302void chan_obuf_empty(Channel *); 303 304/* hpn handler */ 305void channel_set_hpn(int, u_int); 306 307#endif 308