1 /* $OpenBSD: channels.h,v 1.107 2011/09/10 22:26:34 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_MAX_TYPE 17 59 60 #define CHANNEL_CANCEL_PORT_STATIC -1 61 62 struct Channel; 63 typedef struct Channel Channel; 64 65 typedef void channel_open_fn(int, int, void *); 66 typedef void channel_callback_fn(int, void *); 67 typedef int channel_infilter_fn(struct Channel *, char *, int); 68 typedef void channel_filter_cleanup_fn(int, void *); 69 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); 70 71 /* Channel success/failure callbacks */ 72 typedef void channel_confirm_cb(int, struct Channel *, void *); 73 typedef void channel_confirm_abandon_cb(struct Channel *, void *); 74 struct channel_confirm { 75 TAILQ_ENTRY(channel_confirm) entry; 76 channel_confirm_cb *cb; 77 channel_confirm_abandon_cb *abandon_cb; 78 void *ctx; 79 }; 80 TAILQ_HEAD(channel_confirms, channel_confirm); 81 82 /* Context for non-blocking connects */ 83 struct channel_connect { 84 char *host; 85 int port; 86 struct addrinfo *ai, *aitop; 87 }; 88 89 /* Callbacks for mux channels back into client-specific code */ 90 typedef int mux_callback_fn(struct Channel *); 91 92 struct Channel { 93 int type; /* channel type/state */ 94 int self; /* my own channel identifier */ 95 int remote_id; /* channel identifier for remote peer */ 96 u_int istate; /* input from channel (state of receive half) */ 97 u_int ostate; /* output to channel (state of transmit half) */ 98 int flags; /* close sent/rcvd */ 99 int rfd; /* read fd */ 100 int wfd; /* write fd */ 101 int efd; /* extended fd */ 102 int sock; /* sock fd */ 103 int ctl_chan; /* control channel (multiplexed connections) */ 104 int isatty; /* rfd is a tty */ 105 int client_tty; /* (client) TTY has been requested */ 106 int force_drain; /* force close on iEOF */ 107 int delayed; /* post-select handlers for newly created 108 * channels are delayed until the first call 109 * to a matching pre-select handler. 110 * this way post-select handlers are not 111 * accidenly called if a FD gets reused */ 112 Buffer input; /* data read from socket, to be sent over 113 * encrypted connection */ 114 Buffer output; /* data received over encrypted connection for 115 * send on socket */ 116 Buffer extended; 117 char *path; 118 /* path for unix domain sockets, or host name for forwards */ 119 int listening_port; /* port being listened for forwards */ 120 char *listening_addr; /* addr being listened for forwards */ 121 int host_port; /* remote port to connect for forwards */ 122 char *remote_name; /* remote hostname */ 123 124 u_int remote_window; 125 u_int remote_maxpacket; 126 u_int local_window; 127 u_int local_window_max; 128 u_int local_consumed; 129 u_int local_maxpacket; 130 int extended_usage; 131 int single_connection; 132 133 char *ctype; /* type */ 134 135 /* callback */ 136 channel_open_fn *open_confirm; 137 void *open_confirm_ctx; 138 channel_callback_fn *detach_user; 139 int detach_close; 140 struct channel_confirms status_confirms; 141 142 /* filter */ 143 channel_infilter_fn *input_filter; 144 channel_outfilter_fn *output_filter; 145 void *filter_ctx; 146 channel_filter_cleanup_fn *filter_cleanup; 147 148 /* keep boundaries */ 149 int datagram; 150 151 /* non-blocking connect */ 152 struct channel_connect connect_ctx; 153 154 /* multiplexing protocol hook, called for each packet received */ 155 mux_callback_fn *mux_rcb; 156 void *mux_ctx; 157 int mux_pause; 158 }; 159 160 #define CHAN_EXTENDED_IGNORE 0 161 #define CHAN_EXTENDED_READ 1 162 #define CHAN_EXTENDED_WRITE 2 163 164 /* default window/packet sizes for tcp/x11-fwd-channel */ 165 #define CHAN_SES_PACKET_DEFAULT (32*1024) 166 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) 167 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 168 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 169 #define CHAN_X11_PACKET_DEFAULT (16*1024) 170 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 171 172 /* possible input states */ 173 #define CHAN_INPUT_OPEN 0 174 #define CHAN_INPUT_WAIT_DRAIN 1 175 #define CHAN_INPUT_WAIT_OCLOSE 2 176 #define CHAN_INPUT_CLOSED 3 177 178 /* possible output states */ 179 #define CHAN_OUTPUT_OPEN 0 180 #define CHAN_OUTPUT_WAIT_DRAIN 1 181 #define CHAN_OUTPUT_WAIT_IEOF 2 182 #define CHAN_OUTPUT_CLOSED 3 183 184 #define CHAN_CLOSE_SENT 0x01 185 #define CHAN_CLOSE_RCVD 0x02 186 #define CHAN_EOF_SENT 0x04 187 #define CHAN_EOF_RCVD 0x08 188 #define CHAN_LOCAL 0x10 189 190 #define CHAN_RBUF 16*1024 191 192 /* check whether 'efd' is still in use */ 193 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 194 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 195 (c->efd != -1 || \ 196 buffer_len(&c->extended) > 0)) 197 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 198 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 199 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 200 buffer_len(&c->extended) > 0)) 201 202 /* channel management */ 203 204 Channel *channel_by_id(int); 205 Channel *channel_lookup(int); 206 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 207 void channel_set_fds(int, int, int, int, int, int, int, u_int); 208 void channel_free(Channel *); 209 void channel_free_all(void); 210 void channel_stop_listening(void); 211 212 void channel_send_open(int); 213 void channel_request_start(int, char *, int); 214 void channel_register_cleanup(int, channel_callback_fn *, int); 215 void channel_register_open_confirm(int, channel_open_fn *, void *); 216 void channel_register_filter(int, channel_infilter_fn *, 217 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 218 void channel_register_status_confirm(int, channel_confirm_cb *, 219 channel_confirm_abandon_cb *, void *); 220 void channel_cancel_cleanup(int); 221 int channel_close_fd(int *); 222 void channel_send_window_changes(void); 223 224 /* protocol handler */ 225 226 void channel_input_close(int, u_int32_t, void *); 227 void channel_input_close_confirmation(int, u_int32_t, void *); 228 void channel_input_data(int, u_int32_t, void *); 229 void channel_input_extended_data(int, u_int32_t, void *); 230 void channel_input_ieof(int, u_int32_t, void *); 231 void channel_input_oclose(int, u_int32_t, void *); 232 void channel_input_open_confirmation(int, u_int32_t, void *); 233 void channel_input_open_failure(int, u_int32_t, void *); 234 void channel_input_port_open(int, u_int32_t, void *); 235 void channel_input_window_adjust(int, u_int32_t, void *); 236 void channel_input_status_confirm(int, u_int32_t, void *); 237 238 /* file descriptor handling (read/write) */ 239 240 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); 241 void channel_after_select(fd_set *, fd_set *); 242 void channel_output_poll(void); 243 244 int channel_not_very_much_buffered_data(void); 245 void channel_close_all(void); 246 int channel_still_open(void); 247 char *channel_open_message(void); 248 int channel_find_open(void); 249 250 /* tcp forwarding */ 251 void channel_set_af(int af); 252 void channel_permit_all_opens(void); 253 void channel_add_permitted_opens(char *, int); 254 int channel_add_adm_permitted_opens(char *, int); 255 void channel_clear_permitted_opens(void); 256 void channel_clear_adm_permitted_opens(void); 257 void channel_print_adm_permitted_opens(void); 258 int channel_input_port_forward_request(int, int); 259 Channel *channel_connect_to(const char *, u_short, char *, char *); 260 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); 261 Channel *channel_connect_by_listen_address(u_short, char *, char *); 262 int channel_request_remote_forwarding(const char *, u_short, 263 const char *, u_short); 264 int channel_setup_local_fwd_listener(const char *, u_short, 265 const char *, u_short, int); 266 int channel_request_rforward_cancel(const char *host, u_short port); 267 int channel_setup_remote_fwd_listener(const char *, u_short, int *, int); 268 int channel_cancel_rport_listener(const char *, u_short); 269 int channel_cancel_lport_listener(const char *, u_short, int, int); 270 271 /* x11 forwarding */ 272 273 int x11_connect_display(void); 274 int x11_create_display_inet(int, int, int, u_int *, int **); 275 void x11_input_open(int, u_int32_t, void *); 276 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 277 const char *, int); 278 void deny_input_open(int, u_int32_t, void *); 279 280 /* agent forwarding */ 281 282 void auth_request_forwarding(void); 283 284 /* channel close */ 285 286 int chan_is_dead(Channel *, int); 287 void chan_mark_dead(Channel *); 288 289 /* channel events */ 290 291 void chan_rcvd_oclose(Channel *); 292 void chan_rcvd_eow(Channel *); /* SSH2-only */ 293 void chan_read_failed(Channel *); 294 void chan_ibuf_empty(Channel *); 295 296 void chan_rcvd_ieof(Channel *); 297 void chan_write_failed(Channel *); 298 void chan_obuf_empty(Channel *); 299 300 #endif 301