1 /* $OpenBSD: channels.h,v 1.115 2014/07/15 15:54:14 millert Exp $ */ 2 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@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_MAX_TYPE 20 62 63 #define CHANNEL_CANCEL_PORT_STATIC -1 64 65 struct Channel; 66 typedef struct Channel Channel; 67 68 typedef void channel_open_fn(int, int, void *); 69 typedef void channel_callback_fn(int, void *); 70 typedef int channel_infilter_fn(struct Channel *, char *, int); 71 typedef void channel_filter_cleanup_fn(int, void *); 72 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); 73 74 /* Channel success/failure callbacks */ 75 typedef void channel_confirm_cb(int, struct Channel *, void *); 76 typedef void channel_confirm_abandon_cb(struct Channel *, void *); 77 struct channel_confirm { 78 TAILQ_ENTRY(channel_confirm) entry; 79 channel_confirm_cb *cb; 80 channel_confirm_abandon_cb *abandon_cb; 81 void *ctx; 82 }; 83 TAILQ_HEAD(channel_confirms, channel_confirm); 84 85 /* Context for non-blocking connects */ 86 struct channel_connect { 87 char *host; 88 int port; 89 struct addrinfo *ai, *aitop; 90 }; 91 92 /* Callbacks for mux channels back into client-specific code */ 93 typedef int mux_callback_fn(struct Channel *); 94 95 struct Channel { 96 int type; /* channel type/state */ 97 int self; /* my own channel identifier */ 98 int remote_id; /* channel identifier for remote peer */ 99 u_int istate; /* input from channel (state of receive half) */ 100 u_int ostate; /* output to channel (state of transmit half) */ 101 int flags; /* close sent/rcvd */ 102 int rfd; /* read fd */ 103 int wfd; /* write fd */ 104 int efd; /* extended fd */ 105 int sock; /* sock fd */ 106 int ctl_chan; /* control channel (multiplexed connections) */ 107 int isatty; /* rfd is a tty */ 108 #ifdef _AIX 109 int wfd_isatty; /* wfd is a tty */ 110 #endif 111 int client_tty; /* (client) TTY has been requested */ 112 int force_drain; /* force close on iEOF */ 113 time_t notbefore; /* Pause IO until deadline (time_t) */ 114 int delayed; /* post-select handlers for newly created 115 * channels are delayed until the first call 116 * to a matching pre-select handler. 117 * this way post-select handlers are not 118 * accidentally called if a FD gets reused */ 119 Buffer input; /* data read from socket, to be sent over 120 * encrypted connection */ 121 Buffer output; /* data received over encrypted connection for 122 * send on socket */ 123 Buffer extended; 124 char *path; 125 /* path for unix domain sockets, or host name for forwards */ 126 int listening_port; /* port being listened for forwards */ 127 char *listening_addr; /* addr being listened for forwards */ 128 int host_port; /* remote port to connect for forwards */ 129 char *remote_name; /* remote hostname */ 130 131 u_int remote_window; 132 u_int remote_maxpacket; 133 u_int local_window; 134 u_int local_window_max; 135 u_int local_consumed; 136 u_int local_maxpacket; 137 int dynamic_window; 138 int extended_usage; 139 int single_connection; 140 u_int tcpwinsz; 141 142 char *ctype; /* type */ 143 144 /* callback */ 145 channel_open_fn *open_confirm; 146 void *open_confirm_ctx; 147 channel_callback_fn *detach_user; 148 int detach_close; 149 struct channel_confirms status_confirms; 150 151 /* filter */ 152 channel_infilter_fn *input_filter; 153 channel_outfilter_fn *output_filter; 154 void *filter_ctx; 155 channel_filter_cleanup_fn *filter_cleanup; 156 157 /* keep boundaries */ 158 int datagram; 159 160 /* non-blocking connect */ 161 struct channel_connect connect_ctx; 162 163 /* multiplexing protocol hook, called for each packet received */ 164 mux_callback_fn *mux_rcb; 165 void *mux_ctx; 166 int mux_pause; 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) 176 177 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 178 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 179 180 #define CHAN_X11_PACKET_DEFAULT (16*1024) 181 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 182 183 /* possible input states */ 184 #define CHAN_INPUT_OPEN 0 185 #define CHAN_INPUT_WAIT_DRAIN 1 186 #define CHAN_INPUT_WAIT_OCLOSE 2 187 #define CHAN_INPUT_CLOSED 3 188 189 /* possible output states */ 190 #define CHAN_OUTPUT_OPEN 0 191 #define CHAN_OUTPUT_WAIT_DRAIN 1 192 #define CHAN_OUTPUT_WAIT_IEOF 2 193 #define CHAN_OUTPUT_CLOSED 3 194 195 #define CHAN_CLOSE_SENT 0x01 196 #define CHAN_CLOSE_RCVD 0x02 197 #define CHAN_EOF_SENT 0x04 198 #define CHAN_EOF_RCVD 0x08 199 #define CHAN_LOCAL 0x10 200 201 #define CHAN_RBUF 16*1024 202 203 /* check whether 'efd' is still in use */ 204 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 205 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 206 (c->efd != -1 || \ 207 buffer_len(&c->extended) > 0)) 208 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 209 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 210 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 211 buffer_len(&c->extended) > 0)) 212 213 /* channel management */ 214 215 Channel *channel_by_id(int); 216 Channel *channel_lookup(int); 217 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 218 void channel_set_fds(int, int, int, int, int, int, int, u_int); 219 void channel_free(Channel *); 220 void channel_free_all(void); 221 void channel_stop_listening(void); 222 223 void channel_send_open(int); 224 void channel_request_start(int, char *, int); 225 void channel_register_cleanup(int, channel_callback_fn *, int); 226 void channel_register_open_confirm(int, channel_open_fn *, void *); 227 void channel_register_filter(int, channel_infilter_fn *, 228 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 229 void channel_register_status_confirm(int, channel_confirm_cb *, 230 channel_confirm_abandon_cb *, void *); 231 void channel_cancel_cleanup(int); 232 int channel_close_fd(int *); 233 void channel_send_window_changes(void); 234 235 /* protocol handler */ 236 237 void channel_input_close(int, u_int32_t, void *); 238 void channel_input_close_confirmation(int, u_int32_t, void *); 239 void channel_input_data(int, u_int32_t, void *); 240 void channel_input_extended_data(int, u_int32_t, void *); 241 void channel_input_ieof(int, u_int32_t, void *); 242 void channel_input_oclose(int, u_int32_t, void *); 243 void channel_input_open_confirmation(int, u_int32_t, void *); 244 void channel_input_open_failure(int, u_int32_t, void *); 245 void channel_input_port_open(int, u_int32_t, void *); 246 void channel_input_window_adjust(int, u_int32_t, void *); 247 void channel_input_status_confirm(int, u_int32_t, void *); 248 249 /* file descriptor handling (read/write) */ 250 251 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, 252 time_t*, int); 253 void channel_after_select(fd_set *, fd_set *); 254 int channel_output_poll(void); 255 256 int channel_not_very_much_buffered_data(void); 257 void channel_close_all(void); 258 int channel_still_open(void); 259 char *channel_open_message(void); 260 int channel_find_open(void); 261 262 /* tcp forwarding */ 263 struct Forward; 264 struct ForwardOptions; 265 void channel_set_af(int af); 266 void channel_permit_all_opens(void); 267 void channel_add_permitted_opens(char *, int); 268 int channel_add_adm_permitted_opens(char *, int); 269 void channel_disable_adm_local_opens(void); 270 void channel_update_permitted_opens(int, int); 271 void channel_clear_permitted_opens(void); 272 void channel_clear_adm_permitted_opens(void); 273 void channel_print_adm_permitted_opens(void); 274 int channel_input_port_forward_request(int, struct ForwardOptions *); 275 Channel *channel_connect_to_port(const char *, u_short, char *, char *); 276 Channel *channel_connect_to_path(const char *, char *, char *); 277 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); 278 Channel *channel_connect_by_listen_address(const char *, u_short, 279 char *, char *); 280 Channel *channel_connect_by_listen_path(const char *, char *, char *); 281 int channel_request_remote_forwarding(struct Forward *); 282 int channel_setup_local_fwd_listener(struct Forward *, struct ForwardOptions *); 283 int channel_request_rforward_cancel(struct Forward *); 284 int channel_setup_remote_fwd_listener(struct Forward *, int *, struct ForwardOptions *); 285 int channel_cancel_rport_listener(struct Forward *); 286 int channel_cancel_lport_listener(struct Forward *, int, struct ForwardOptions *); 287 int permitopen_port(const char *); 288 289 /* x11 forwarding */ 290 291 int x11_connect_display(void); 292 int x11_create_display_inet(int, int, int, u_int *, int **); 293 void x11_input_open(int, u_int32_t, void *); 294 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 295 const char *, int); 296 void deny_input_open(int, u_int32_t, void *); 297 298 /* agent forwarding */ 299 300 void auth_request_forwarding(void); 301 302 /* channel close */ 303 304 int chan_is_dead(Channel *, int); 305 void chan_mark_dead(Channel *); 306 307 /* channel events */ 308 309 void chan_rcvd_oclose(Channel *); 310 void chan_rcvd_eow(Channel *); /* SSH2-only */ 311 void chan_read_failed(Channel *); 312 void chan_ibuf_empty(Channel *); 313 314 void chan_rcvd_ieof(Channel *); 315 void chan_write_failed(Channel *); 316 void chan_obuf_empty(Channel *); 317 318 /* hpn handler */ 319 void channel_set_hpn(int, int); 320 321 #endif 322