1 /* $OpenBSD: channels.h,v 1.116 2015/01/19 20:07:45 markus 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 extended_usage; 138 int single_connection; 139 140 char *ctype; /* type */ 141 142 /* callback */ 143 channel_open_fn *open_confirm; 144 void *open_confirm_ctx; 145 channel_callback_fn *detach_user; 146 int detach_close; 147 struct channel_confirms status_confirms; 148 149 /* filter */ 150 channel_infilter_fn *input_filter; 151 channel_outfilter_fn *output_filter; 152 void *filter_ctx; 153 channel_filter_cleanup_fn *filter_cleanup; 154 155 /* keep boundaries */ 156 int datagram; 157 158 /* non-blocking connect */ 159 struct channel_connect connect_ctx; 160 161 /* multiplexing protocol hook, called for each packet received */ 162 mux_callback_fn *mux_rcb; 163 void *mux_ctx; 164 int mux_pause; 165 }; 166 167 #define CHAN_EXTENDED_IGNORE 0 168 #define CHAN_EXTENDED_READ 1 169 #define CHAN_EXTENDED_WRITE 2 170 171 /* default window/packet sizes for tcp/x11-fwd-channel */ 172 #define CHAN_SES_PACKET_DEFAULT (32*1024) 173 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) 174 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 175 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 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(char *, int, int, int, int, u_int, u_int, int, char *, int); 214 void channel_set_fds(int, int, int, int, int, int, int, u_int); 215 void channel_free(Channel *); 216 void channel_free_all(void); 217 void channel_stop_listening(void); 218 219 void channel_send_open(int); 220 void channel_request_start(int, char *, int); 221 void channel_register_cleanup(int, channel_callback_fn *, int); 222 void channel_register_open_confirm(int, channel_open_fn *, void *); 223 void channel_register_filter(int, channel_infilter_fn *, 224 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 225 void channel_register_status_confirm(int, channel_confirm_cb *, 226 channel_confirm_abandon_cb *, void *); 227 void channel_cancel_cleanup(int); 228 int channel_close_fd(int *); 229 void channel_send_window_changes(void); 230 231 /* protocol handler */ 232 233 int channel_input_close(int, u_int32_t, void *); 234 int channel_input_close_confirmation(int, u_int32_t, void *); 235 int channel_input_data(int, u_int32_t, void *); 236 int channel_input_extended_data(int, u_int32_t, void *); 237 int channel_input_ieof(int, u_int32_t, void *); 238 int channel_input_oclose(int, u_int32_t, void *); 239 int channel_input_open_confirmation(int, u_int32_t, void *); 240 int channel_input_open_failure(int, u_int32_t, void *); 241 int channel_input_port_open(int, u_int32_t, void *); 242 int channel_input_window_adjust(int, u_int32_t, void *); 243 int channel_input_status_confirm(int, u_int32_t, void *); 244 245 /* file descriptor handling (read/write) */ 246 247 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, 248 time_t*, int); 249 void channel_after_select(fd_set *, fd_set *); 250 void channel_output_poll(void); 251 252 int channel_not_very_much_buffered_data(void); 253 void channel_close_all(void); 254 int channel_still_open(void); 255 char *channel_open_message(void); 256 int channel_find_open(void); 257 258 /* tcp forwarding */ 259 struct Forward; 260 struct ForwardOptions; 261 void channel_set_af(int af); 262 void channel_permit_all_opens(void); 263 void channel_add_permitted_opens(char *, int); 264 int channel_add_adm_permitted_opens(char *, int); 265 void channel_disable_adm_local_opens(void); 266 void channel_update_permitted_opens(int, int); 267 void channel_clear_permitted_opens(void); 268 void channel_clear_adm_permitted_opens(void); 269 void channel_print_adm_permitted_opens(void); 270 int channel_input_port_forward_request(int, struct ForwardOptions *); 271 Channel *channel_connect_to_port(const char *, u_short, char *, char *); 272 Channel *channel_connect_to_path(const char *, char *, char *); 273 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); 274 Channel *channel_connect_by_listen_address(const char *, u_short, 275 char *, char *); 276 Channel *channel_connect_by_listen_path(const char *, char *, char *); 277 int channel_request_remote_forwarding(struct Forward *); 278 int channel_setup_local_fwd_listener(struct Forward *, struct ForwardOptions *); 279 int channel_request_rforward_cancel(struct Forward *); 280 int channel_setup_remote_fwd_listener(struct Forward *, int *, struct ForwardOptions *); 281 int channel_cancel_rport_listener(struct Forward *); 282 int channel_cancel_lport_listener(struct Forward *, int, struct ForwardOptions *); 283 int permitopen_port(const char *); 284 285 /* x11 forwarding */ 286 287 int x11_connect_display(void); 288 int x11_create_display_inet(int, int, int, u_int *, int **); 289 int x11_input_open(int, u_int32_t, void *); 290 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 291 const char *, int); 292 int deny_input_open(int, u_int32_t, void *); 293 294 /* agent forwarding */ 295 296 void auth_request_forwarding(void); 297 298 /* channel close */ 299 300 int chan_is_dead(Channel *, int); 301 void chan_mark_dead(Channel *); 302 303 /* channel events */ 304 305 void chan_rcvd_oclose(Channel *); 306 void chan_rcvd_eow(Channel *); /* SSH2-only */ 307 void chan_read_failed(Channel *); 308 void chan_ibuf_empty(Channel *); 309 310 void chan_rcvd_ieof(Channel *); 311 void chan_write_failed(Channel *); 312 void chan_obuf_empty(Channel *); 313 314 #endif 315