1 /* $NetBSD: channels.h,v 1.8 2013/11/08 19:18:24 christos Exp $ */ 2 /* $OpenBSD: channels.h,v 1.113 2013/06/07 15:37:52 dtucker Exp $ */ 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_ABANDONED 17 /* Abandoned session, eg mux */ 60 #define SSH_CHANNEL_MAX_TYPE 18 61 62 #define CHANNEL_CANCEL_PORT_STATIC -1 63 64 struct Channel; 65 typedef struct Channel Channel; 66 67 typedef void channel_open_fn(int, int, void *); 68 typedef void channel_callback_fn(int, void *); 69 typedef int channel_infilter_fn(struct Channel *, const char *, int); 70 typedef void channel_filter_cleanup_fn(int, void *); 71 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); 72 73 /* Channel success/failure callbacks */ 74 typedef void channel_confirm_cb(int, struct Channel *, void *); 75 typedef void channel_confirm_abandon_cb(struct Channel *, void *); 76 struct channel_confirm { 77 TAILQ_ENTRY(channel_confirm) entry; 78 channel_confirm_cb *cb; 79 channel_confirm_abandon_cb *abandon_cb; 80 void *ctx; 81 }; 82 TAILQ_HEAD(channel_confirms, channel_confirm); 83 84 /* Context for non-blocking connects */ 85 struct channel_connect { 86 char *host; 87 int port; 88 struct addrinfo *ai, *aitop; 89 }; 90 91 /* Callbacks for mux channels back into client-specific code */ 92 typedef int mux_callback_fn(struct Channel *); 93 94 struct Channel { 95 int type; /* channel type/state */ 96 int self; /* my own channel identifier */ 97 int remote_id; /* channel identifier for remote peer */ 98 u_int istate; /* input from channel (state of receive half) */ 99 u_int ostate; /* output to channel (state of transmit half) */ 100 int flags; /* close sent/rcvd */ 101 int rfd; /* read fd */ 102 int wfd; /* write fd */ 103 int efd; /* extended fd */ 104 int sock; /* sock fd */ 105 int ctl_chan; /* control channel (multiplexed connections) */ 106 int isatty; /* rfd is a tty */ 107 int client_tty; /* (client) TTY has been requested */ 108 int force_drain; /* force close on iEOF */ 109 time_t notbefore; /* Pause IO until deadline (time_t) */ 110 int delayed; /* post-select handlers for newly created 111 * channels are delayed until the first call 112 * to a matching pre-select handler. 113 * this way post-select handlers are not 114 * accidentally called if a FD gets reused */ 115 Buffer input; /* data read from socket, to be sent over 116 * encrypted connection */ 117 Buffer output; /* data received over encrypted connection for 118 * send on socket */ 119 Buffer extended; 120 char *path; 121 /* path for unix domain sockets, or host name for forwards */ 122 int listening_port; /* port being listened for forwards */ 123 char *listening_addr; /* addr being listened for forwards */ 124 int host_port; /* remote port to connect for forwards */ 125 char *remote_name; /* remote hostname */ 126 127 u_int remote_window; 128 u_int remote_maxpacket; 129 u_int local_window; 130 u_int local_window_max; 131 u_int local_consumed; 132 u_int local_maxpacket; 133 int dynamic_window; 134 int extended_usage; 135 int single_connection; 136 u_int tcpwinsz; 137 138 char *ctype; /* type */ 139 140 /* callback */ 141 channel_open_fn *open_confirm; 142 void *open_confirm_ctx; 143 channel_callback_fn *detach_user; 144 int detach_close; 145 struct channel_confirms status_confirms; 146 147 /* filter */ 148 channel_infilter_fn *input_filter; 149 channel_outfilter_fn *output_filter; 150 void *filter_ctx; 151 channel_filter_cleanup_fn *filter_cleanup; 152 153 /* keep boundaries */ 154 int datagram; 155 156 /* non-blocking connect */ 157 struct channel_connect connect_ctx; 158 159 /* multiplexing protocol hook, called for each packet received */ 160 mux_callback_fn *mux_rcb; 161 void *mux_ctx; 162 int mux_pause; 163 }; 164 165 #define CHAN_EXTENDED_IGNORE 0 166 #define CHAN_EXTENDED_READ 1 167 #define CHAN_EXTENDED_WRITE 2 168 169 /* default window/packet sizes for tcp/x11-fwd-channel */ 170 #define CHAN_SES_PACKET_DEFAULT (32*1024) 171 #define CHAN_SES_WINDOW_DEFAULT (4*CHAN_SES_PACKET_DEFAULT) 172 173 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 174 #define CHAN_TCP_WINDOW_DEFAULT (4*CHAN_TCP_PACKET_DEFAULT) 175 176 #define CHAN_X11_PACKET_DEFAULT (16*1024) 177 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 178 179 /* possible input states */ 180 #define CHAN_INPUT_OPEN 0 181 #define CHAN_INPUT_WAIT_DRAIN 1 182 #define CHAN_INPUT_WAIT_OCLOSE 2 183 #define CHAN_INPUT_CLOSED 3 184 185 /* possible output states */ 186 #define CHAN_OUTPUT_OPEN 0 187 #define CHAN_OUTPUT_WAIT_DRAIN 1 188 #define CHAN_OUTPUT_WAIT_IEOF 2 189 #define CHAN_OUTPUT_CLOSED 3 190 191 #define CHAN_CLOSE_SENT 0x01 192 #define CHAN_CLOSE_RCVD 0x02 193 #define CHAN_EOF_SENT 0x04 194 #define CHAN_EOF_RCVD 0x08 195 #define CHAN_LOCAL 0x10 196 197 #define CHAN_RBUF 16*1024 198 199 /* check whether 'efd' is still in use */ 200 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 201 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 202 (c->efd != -1 || \ 203 buffer_len(&c->extended) > 0)) 204 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 205 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 206 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 207 buffer_len(&c->extended) > 0)) 208 209 /* channel management */ 210 211 Channel *channel_by_id(int); 212 Channel *channel_lookup(int); 213 Channel *channel_new(const char *, int, int, int, int, u_int, u_int, int, 214 const char *, int); 215 void channel_set_fds(int, int, int, int, int, int, int, u_int); 216 void channel_free(Channel *); 217 void channel_free_all(void); 218 void channel_stop_listening(void); 219 220 void channel_send_open(int); 221 void channel_request_start(int, const char *, int); 222 void channel_register_cleanup(int, channel_callback_fn *, int); 223 void channel_register_open_confirm(int, channel_open_fn *, void *); 224 void channel_register_filter(int, channel_infilter_fn *, 225 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 226 void channel_register_status_confirm(int, channel_confirm_cb *, 227 channel_confirm_abandon_cb *, void *); 228 void channel_cancel_cleanup(int); 229 int channel_close_fd(int *); 230 void channel_send_window_changes(void); 231 232 /* protocol handler */ 233 234 void channel_input_close(int, u_int32_t, void *); 235 void channel_input_close_confirmation(int, u_int32_t, void *); 236 void channel_input_data(int, u_int32_t, void *); 237 void channel_input_extended_data(int, u_int32_t, void *); 238 void channel_input_ieof(int, u_int32_t, void *); 239 void channel_input_oclose(int, u_int32_t, void *); 240 void channel_input_open_confirmation(int, u_int32_t, void *); 241 void channel_input_open_failure(int, u_int32_t, void *); 242 void channel_input_port_open(int, u_int32_t, void *); 243 void channel_input_window_adjust(int, u_int32_t, void *); 244 void channel_input_status_confirm(int, u_int32_t, void *); 245 246 /* file descriptor handling (read/write) */ 247 248 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, 249 time_t*, int); 250 void channel_after_select(fd_set *, fd_set *); 251 int channel_output_poll(void); 252 253 int channel_not_very_much_buffered_data(void); 254 void channel_close_all(void); 255 int channel_still_open(void); 256 char *channel_open_message(void); 257 int channel_find_open(void); 258 259 /* tcp forwarding */ 260 void channel_set_af(int af); 261 void channel_permit_all_opens(void); 262 void channel_add_permitted_opens(char *, int); 263 int channel_add_adm_permitted_opens(char *, int); 264 void channel_disable_adm_local_opens(void); 265 void channel_update_permitted_opens(int, int); 266 void channel_clear_permitted_opens(void); 267 void channel_clear_adm_permitted_opens(void); 268 void channel_print_adm_permitted_opens(void); 269 int channel_input_port_forward_request(int, int); 270 Channel *channel_connect_to(const char *, u_short, const char *, const char *); 271 Channel *channel_connect_stdio_fwd(const char *, u_short, int, int); 272 Channel *channel_connect_by_listen_address(u_short, const char *, const char *); 273 int channel_request_remote_forwarding(const char *, u_short, 274 const char *, u_short); 275 int channel_setup_local_fwd_listener(const char *, u_short, 276 const char *, u_short, int); 277 int channel_request_rforward_cancel(const char *host, u_short port); 278 int channel_setup_remote_fwd_listener(const char *, u_short, int *, int); 279 int channel_cancel_rport_listener(const char *, u_short); 280 int channel_cancel_lport_listener(const char *, u_short, int, int); 281 int permitopen_port(const char *); 282 283 /* x11 forwarding */ 284 285 int x11_connect_display(void); 286 int x11_create_display_inet(int, int, int, u_int *, int **); 287 void x11_input_open(int, u_int32_t, void *); 288 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 289 const char *, int); 290 void deny_input_open(int, u_int32_t, void *); 291 292 /* agent forwarding */ 293 294 void auth_request_forwarding(void); 295 296 /* channel close */ 297 298 int chan_is_dead(Channel *, int); 299 void chan_mark_dead(Channel *); 300 301 /* channel events */ 302 303 void chan_rcvd_oclose(Channel *); 304 void chan_rcvd_eow(Channel *); /* SSH2-only */ 305 void chan_read_failed(Channel *); 306 void chan_ibuf_empty(Channel *); 307 308 void chan_rcvd_ieof(Channel *); 309 void chan_write_failed(Channel *); 310 void chan_obuf_empty(Channel *); 311 312 /* hpn handler */ 313 void channel_set_hpn(int, int); 314 315 #endif 316