1 /* $OpenBSD: channels.h,v 1.113 2013/06/07 15:37:52 dtucker 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_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 *, 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 #ifdef _AIX 108 int wfd_isatty; /* wfd is a tty */ 109 #endif 110 int client_tty; /* (client) TTY has been requested */ 111 int force_drain; /* force close on iEOF */ 112 time_t notbefore; /* Pause IO until deadline (time_t) */ 113 int delayed; /* post-select handlers for newly created 114 * channels are delayed until the first call 115 * to a matching pre-select handler. 116 * this way post-select handlers are not 117 * accidentally called if a FD gets reused */ 118 Buffer input; /* data read from socket, to be sent over 119 * encrypted connection */ 120 Buffer output; /* data received over encrypted connection for 121 * send on socket */ 122 Buffer extended; 123 char *path; 124 /* path for unix domain sockets, or host name for forwards */ 125 int listening_port; /* port being listened for forwards */ 126 char *listening_addr; /* addr being listened for forwards */ 127 int host_port; /* remote port to connect for forwards */ 128 char *remote_name; /* remote hostname */ 129 130 u_int remote_window; 131 u_int remote_maxpacket; 132 u_int local_window; 133 u_int local_window_max; 134 u_int local_consumed; 135 u_int local_maxpacket; 136 u_int tcpwinsz; 137 int dynamic_window; 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 }; 167 168 #define CHAN_EXTENDED_IGNORE 0 169 #define CHAN_EXTENDED_READ 1 170 #define CHAN_EXTENDED_WRITE 2 171 172 /* default window/packet sizes for tcp/x11-fwd-channel */ 173 #define CHAN_SES_PACKET_DEFAULT (32*1024) 174 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) 175 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 176 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 177 #define CHAN_X11_PACKET_DEFAULT (16*1024) 178 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 179 #define CHAN_HPN_MIN_WINDOW_DEFAULT (2*1024*1024) 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_lookup(int); 215 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 216 void channel_set_fds(int, int, int, int, int, int, int, u_int); 217 void channel_free(Channel *); 218 void channel_free_all(void); 219 void channel_stop_listening(void); 220 221 void channel_send_open(int); 222 void channel_request_start(int, char *, int); 223 void channel_register_cleanup(int, channel_callback_fn *, int); 224 void channel_register_open_confirm(int, channel_open_fn *, void *); 225 void channel_register_filter(int, channel_infilter_fn *, 226 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 227 void channel_register_status_confirm(int, channel_confirm_cb *, 228 channel_confirm_abandon_cb *, void *); 229 void channel_cancel_cleanup(int); 230 int channel_close_fd(int *); 231 void channel_send_window_changes(void); 232 233 /* protocol handler */ 234 235 void channel_input_close(int, u_int32_t, void *); 236 void channel_input_close_confirmation(int, u_int32_t, void *); 237 void channel_input_data(int, u_int32_t, void *); 238 void channel_input_extended_data(int, u_int32_t, void *); 239 void channel_input_ieof(int, u_int32_t, void *); 240 void channel_input_oclose(int, u_int32_t, void *); 241 void channel_input_open_confirmation(int, u_int32_t, void *); 242 void channel_input_open_failure(int, u_int32_t, void *); 243 void channel_input_port_open(int, u_int32_t, void *); 244 void channel_input_window_adjust(int, u_int32_t, void *); 245 void channel_input_status_confirm(int, u_int32_t, void *); 246 247 /* file descriptor handling (read/write) */ 248 249 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, 250 time_t*, int); 251 void channel_after_select(fd_set *, fd_set *); 252 void channel_output_poll(void); 253 254 int channel_not_very_much_buffered_data(void); 255 void channel_close_all(void); 256 int channel_still_open(void); 257 char *channel_open_message(void); 258 int channel_find_open(void); 259 260 /* tcp forwarding */ 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, int); 271 Channel *channel_connect_to(const char *, u_short, char *, char *); 272 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); 273 Channel *channel_connect_by_listen_address(u_short, char *, char *); 274 int channel_request_remote_forwarding(const char *, u_short, 275 const char *, u_short); 276 int channel_setup_local_fwd_listener(const char *, u_short, 277 const char *, u_short, int); 278 int channel_request_rforward_cancel(const char *host, u_short port); 279 int channel_setup_remote_fwd_listener(const char *, u_short, int *, int); 280 int channel_cancel_rport_listener(const char *, u_short); 281 int channel_cancel_lport_listener(const char *, u_short, int, int); 282 int permitopen_port(const char *); 283 284 /* x11 forwarding */ 285 286 int x11_connect_display(void); 287 int x11_create_display_inet(int, int, int, u_int *, int **); 288 void x11_input_open(int, u_int32_t, void *); 289 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 290 const char *, int); 291 void deny_input_open(int, u_int32_t, void *); 292 293 /* agent forwarding */ 294 295 void auth_request_forwarding(void); 296 297 /* channel close */ 298 299 int chan_is_dead(Channel *, int); 300 void chan_mark_dead(Channel *); 301 302 /* channel events */ 303 304 void chan_rcvd_oclose(Channel *); 305 void chan_rcvd_eow(Channel *); /* SSH2-only */ 306 void chan_read_failed(Channel *); 307 void chan_ibuf_empty(Channel *); 308 309 void chan_rcvd_ieof(Channel *); 310 void chan_write_failed(Channel *); 311 void chan_obuf_empty(Channel *); 312 313 /* hpn handler */ 314 315 void channel_set_hpn(int, u_int); 316 317 #endif 318