1 /* $OpenBSD: channels.h,v 1.121 2017/02/01 02:59:09 dtucker Exp $ */ 2 3 /* 4 * Author: Tatu Ylonen <ylo (at) cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo (at) cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 */ 14 /* 15 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #ifndef CHANNEL_H 39 #define CHANNEL_H 40 41 /* Definitions for channel types. */ 42 #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */ 43 #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */ 44 #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */ 45 #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */ 46 #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */ 47 #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */ 48 #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */ 49 #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */ 50 #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */ 51 #define SSH_CHANNEL_LARVAL 10 /* larval session */ 52 #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */ 53 #define SSH_CHANNEL_CONNECTING 12 54 #define SSH_CHANNEL_DYNAMIC 13 55 #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */ 56 #define SSH_CHANNEL_MUX_LISTENER 15 /* Listener for mux conn. */ 57 #define SSH_CHANNEL_MUX_CLIENT 16 /* Conn. to mux slave */ 58 #define SSH_CHANNEL_ABANDONED 17 /* Abandoned session, eg mux */ 59 #define SSH_CHANNEL_UNIX_LISTENER 18 /* Listening on a domain socket. */ 60 #define SSH_CHANNEL_RUNIX_LISTENER 19 /* Listening to a R-style domain socket. */ 61 #define SSH_CHANNEL_MUX_PROXY 20 /* proxy channel for mux-slave */ 62 #define SSH_CHANNEL_MAX_TYPE 21 63 64 #define CHANNEL_CANCEL_PORT_STATIC -1 65 66 struct Channel; 67 typedef struct Channel Channel; 68 69 typedef void channel_open_fn(int, int, void *); 70 typedef void channel_callback_fn(int, void *); 71 typedef int channel_infilter_fn(struct Channel *, char *, int); 72 typedef void channel_filter_cleanup_fn(int, void *); 73 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); 74 75 /* Channel success/failure callbacks */ 76 typedef void channel_confirm_cb(int, struct Channel *, void *); 77 typedef void channel_confirm_abandon_cb(struct Channel *, void *); 78 struct channel_confirm { 79 TAILQ_ENTRY(channel_confirm) entry; 80 channel_confirm_cb *cb; 81 channel_confirm_abandon_cb *abandon_cb; 82 void *ctx; 83 }; 84 TAILQ_HEAD(channel_confirms, channel_confirm); 85 86 /* Context for non-blocking connects */ 87 struct channel_connect { 88 char *host; 89 int port; 90 struct addrinfo *ai, *aitop; 91 }; 92 93 /* Callbacks for mux channels back into client-specific code */ 94 typedef int mux_callback_fn(struct Channel *); 95 96 struct Channel { 97 int type; /* channel type/state */ 98 int self; /* my own channel identifier */ 99 int remote_id; /* channel identifier for remote peer */ 100 u_int istate; /* input from channel (state of receive half) */ 101 u_int ostate; /* output to channel (state of transmit half) */ 102 int flags; /* close sent/rcvd */ 103 int rfd; /* read fd */ 104 int wfd; /* write fd */ 105 int efd; /* extended fd */ 106 int sock; /* sock fd */ 107 int ctl_chan; /* control channel (multiplexed connections) */ 108 int isatty; /* rfd is a tty */ 109 #ifdef _AIX 110 int wfd_isatty; /* wfd is a tty */ 111 #endif 112 int client_tty; /* (client) TTY has been requested */ 113 int force_drain; /* force close on iEOF */ 114 time_t notbefore; /* Pause IO until deadline (time_t) */ 115 int delayed; /* post-select handlers for newly created 116 * channels are delayed until the first call 117 * to a matching pre-select handler. 118 * this way post-select handlers are not 119 * accidentally called if a FD gets reused */ 120 Buffer input; /* data read from socket, to be sent over 121 * encrypted connection */ 122 Buffer output; /* data received over encrypted connection for 123 * send on socket */ 124 Buffer extended; 125 char *path; 126 /* path for unix domain sockets, or host name for forwards */ 127 int listening_port; /* port being listened for forwards */ 128 char *listening_addr; /* addr being listened for forwards */ 129 int host_port; /* remote port to connect for forwards */ 130 char *remote_name; /* remote hostname */ 131 132 u_int remote_window; 133 u_int remote_maxpacket; 134 u_int local_window; 135 u_int local_window_max; 136 u_int local_consumed; 137 u_int local_maxpacket; 138 int extended_usage; 139 int single_connection; 140 141 char *ctype; /* type */ 142 143 /* callback */ 144 channel_open_fn *open_confirm; 145 void *open_confirm_ctx; 146 channel_callback_fn *detach_user; 147 int detach_close; 148 struct channel_confirms status_confirms; 149 150 /* filter */ 151 channel_infilter_fn *input_filter; 152 channel_outfilter_fn *output_filter; 153 void *filter_ctx; 154 channel_filter_cleanup_fn *filter_cleanup; 155 156 /* keep boundaries */ 157 int datagram; 158 159 /* non-blocking connect */ 160 struct channel_connect connect_ctx; 161 162 /* multiplexing protocol hook, called for each packet received */ 163 mux_callback_fn *mux_rcb; 164 void *mux_ctx; 165 int mux_pause; 166 int mux_downstream_id; 167 }; 168 169 #define CHAN_EXTENDED_IGNORE 0 170 #define CHAN_EXTENDED_READ 1 171 #define CHAN_EXTENDED_WRITE 2 172 173 /* default window/packet sizes for tcp/x11-fwd-channel */ 174 #define CHAN_SES_PACKET_DEFAULT (32*1024) 175 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) 176 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 177 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 178 #define CHAN_X11_PACKET_DEFAULT (16*1024) 179 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 180 181 /* possible input states */ 182 #define CHAN_INPUT_OPEN 0 183 #define CHAN_INPUT_WAIT_DRAIN 1 184 #define CHAN_INPUT_WAIT_OCLOSE 2 185 #define CHAN_INPUT_CLOSED 3 186 187 /* possible output states */ 188 #define CHAN_OUTPUT_OPEN 0 189 #define CHAN_OUTPUT_WAIT_DRAIN 1 190 #define CHAN_OUTPUT_WAIT_IEOF 2 191 #define CHAN_OUTPUT_CLOSED 3 192 193 #define CHAN_CLOSE_SENT 0x01 194 #define CHAN_CLOSE_RCVD 0x02 195 #define CHAN_EOF_SENT 0x04 196 #define CHAN_EOF_RCVD 0x08 197 #define CHAN_LOCAL 0x10 198 199 #define CHAN_RBUF 16*1024 200 201 /* check whether 'efd' is still in use */ 202 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 203 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 204 (c->efd != -1 || \ 205 buffer_len(&c->extended) > 0)) 206 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 207 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 208 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 209 buffer_len(&c->extended) > 0)) 210 211 /* channel management */ 212 213 Channel *channel_by_id(int); 214 Channel *channel_by_remote_id(int); 215 Channel *channel_lookup(int); 216 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 217 void channel_set_fds(int, int, int, int, int, int, int, u_int); 218 void channel_free(Channel *); 219 void channel_free_all(void); 220 void channel_stop_listening(void); 221 222 void channel_send_open(int); 223 void channel_request_start(int, char *, int); 224 void channel_register_cleanup(int, channel_callback_fn *, int); 225 void channel_register_open_confirm(int, channel_open_fn *, void *); 226 void channel_register_filter(int, channel_infilter_fn *, 227 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 228 void channel_register_status_confirm(int, channel_confirm_cb *, 229 channel_confirm_abandon_cb *, void *); 230 void channel_cancel_cleanup(int); 231 int channel_close_fd(int *); 232 void channel_send_window_changes(void); 233 234 /* mux proxy support */ 235 236 int channel_proxy_downstream(Channel *mc); 237 int channel_proxy_upstream(Channel *, int, u_int32_t, void *); 238 239 /* protocol handler */ 240 241 int channel_input_close(int, u_int32_t, void *); 242 int channel_input_close_confirmation(int, u_int32_t, void *); 243 int channel_input_data(int, u_int32_t, void *); 244 int channel_input_extended_data(int, u_int32_t, void *); 245 int channel_input_ieof(int, u_int32_t, void *); 246 int channel_input_oclose(int, u_int32_t, void *); 247 int channel_input_open_confirmation(int, u_int32_t, void *); 248 int channel_input_open_failure(int, u_int32_t, void *); 249 int channel_input_port_open(int, u_int32_t, void *); 250 int channel_input_window_adjust(int, u_int32_t, void *); 251 int channel_input_status_confirm(int, u_int32_t, void *); 252 253 /* file descriptor handling (read/write) */ 254 255 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, 256 time_t*, int); 257 void channel_after_select(fd_set *, fd_set *); 258 void channel_output_poll(void); 259 260 int channel_not_very_much_buffered_data(void); 261 void channel_close_all(void); 262 int channel_still_open(void); 263 char *channel_open_message(void); 264 int channel_find_open(void); 265 266 /* tcp forwarding */ 267 struct Forward; 268 struct ForwardOptions; 269 void channel_set_af(int af); 270 void channel_permit_all_opens(void); 271 void channel_add_permitted_opens(char *, int); 272 int channel_add_adm_permitted_opens(char *, int); 273 void channel_disable_adm_local_opens(void); 274 void channel_update_permitted_opens(int, int); 275 void channel_clear_permitted_opens(void); 276 void channel_clear_adm_permitted_opens(void); 277 void channel_print_adm_permitted_opens(void); 278 Channel *channel_connect_to_port(const char *, u_short, char *, char *, int *, 279 const char **); 280 Channel *channel_connect_to_path(const char *, char *, char *); 281 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); 282 Channel *channel_connect_by_listen_address(const char *, u_short, 283 char *, char *); 284 Channel *channel_connect_by_listen_path(const char *, char *, char *); 285 int channel_request_remote_forwarding(struct Forward *); 286 int channel_setup_local_fwd_listener(struct Forward *, struct ForwardOptions *); 287 int channel_request_rforward_cancel(struct Forward *); 288 int channel_setup_remote_fwd_listener(struct Forward *, int *, struct ForwardOptions *); 289 int channel_cancel_rport_listener(struct Forward *); 290 int channel_cancel_lport_listener(struct Forward *, int, struct ForwardOptions *); 291 int permitopen_port(const char *); 292 293 /* x11 forwarding */ 294 295 void channel_set_x11_refuse_time(u_int); 296 int x11_connect_display(void); 297 int x11_create_display_inet(int, int, int, u_int *, int **); 298 int x11_input_open(int, u_int32_t, void *); 299 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 300 const char *, int); 301 int deny_input_open(int, u_int32_t, void *); 302 303 /* agent forwarding */ 304 305 void auth_request_forwarding(void); 306 307 /* channel close */ 308 309 int chan_is_dead(Channel *, int); 310 void chan_mark_dead(Channel *); 311 312 /* channel events */ 313 314 void chan_rcvd_oclose(Channel *); 315 void chan_rcvd_eow(Channel *); /* SSH2-only */ 316 void chan_read_failed(Channel *); 317 void chan_ibuf_empty(Channel *); 318 319 void chan_rcvd_ieof(Channel *); 320 void chan_write_failed(Channel *); 321 void chan_obuf_empty(Channel *); 322 323 #endif 324
