Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 1 | /* $OpenBSD: channels.h,v 1.121 2017/02/01 02:59:09 dtucker Exp $ */ |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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 */ |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 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. */ |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 61 | #define SSH_CHANNEL_MUX_PROXY 20 /* proxy channel for mux-slave */ |
| 62 | #define SSH_CHANNEL_MAX_TYPE 21 |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 63 | |
| 64 | #define CHANNEL_CANCEL_PORT_STATIC -1 |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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 */ |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 109 | #ifdef _AIX |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 110 | int wfd_isatty; /* wfd is a tty */ |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 111 | #endif |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 112 | int client_tty; /* (client) TTY has been requested */ |
| 113 | int force_drain; /* force close on iEOF */ |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 114 | time_t notbefore; /* Pause IO until deadline (time_t) */ |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 115 | int delayed; /* post-select handlers for newly created |
| 116 | * channels are delayed until the first call |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 117 | * to a matching pre-select handler. |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 118 | * this way post-select handlers are not |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 119 | * accidentally called if a FD gets reused */ |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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 */ |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 128 | char *listening_addr; /* addr being listened for forwards */ |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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; |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 166 | int mux_downstream_id; |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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); |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 214 | Channel *channel_by_remote_id(int); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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 | |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 234 | /* mux proxy support */ |
| 235 | |
| 236 | int channel_proxy_downstream(Channel *mc); |
| 237 | int channel_proxy_upstream(Channel *, int, u_int32_t, void *); |
| 238 | |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 239 | /* protocol handler */ |
| 240 | |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 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 *); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 252 | |
| 253 | /* file descriptor handling (read/write) */ |
| 254 | |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 255 | void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, |
| 256 | time_t*, int); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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 */ |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 267 | struct Forward; |
| 268 | struct ForwardOptions; |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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); |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 273 | void channel_disable_adm_local_opens(void); |
| 274 | void channel_update_permitted_opens(int, int); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 275 | void channel_clear_permitted_opens(void); |
| 276 | void channel_clear_adm_permitted_opens(void); |
| 277 | void channel_print_adm_permitted_opens(void); |
Greg Hartman | 9768ca4 | 2017-06-22 20:49:52 -0700 | [diff] [blame] | 278 | Channel *channel_connect_to_port(const char *, u_short, char *, char *, int *, |
| 279 | const char **); |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 280 | Channel *channel_connect_to_path(const char *, char *, char *); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 281 | Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 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 *); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 292 | |
| 293 | /* x11 forwarding */ |
| 294 | |
Greg Hartman | ccacbc9 | 2016-02-03 09:59:44 -0800 | [diff] [blame] | 295 | void channel_set_x11_refuse_time(u_int); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 296 | int x11_connect_display(void); |
| 297 | int x11_create_display_inet(int, int, int, u_int *, int **); |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 298 | int x11_input_open(int, u_int32_t, void *); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 299 | void x11_request_forwarding_with_spoofing(int, const char *, const char *, |
| 300 | const char *, int); |
Adam Langley | d059297 | 2015-03-30 14:49:51 -0700 | [diff] [blame] | 301 | int deny_input_open(int, u_int32_t, void *); |
Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 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 |