1 /* $OpenBSD: channels.h,v 1.103 2010/01/26 01:28:35 djm 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 struct Channel; 61 typedef struct Channel Channel; 62 63 typedef void channel_callback_fn(int, void *); 64 typedef int channel_infilter_fn(struct Channel *, char *, int); 65 typedef void channel_filter_cleanup_fn(int, void *); 66 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); 67 68 /* Channel success/failure callbacks */ 69 typedef void channel_confirm_cb(int, struct Channel *, void *); 70 typedef void channel_confirm_abandon_cb(struct Channel *, void *); 71 struct channel_confirm { 72 TAILQ_ENTRY(channel_confirm) entry; 73 channel_confirm_cb *cb; 74 channel_confirm_abandon_cb *abandon_cb; 75 void *ctx; 76 }; 77 TAILQ_HEAD(channel_confirms, channel_confirm); 78 79 /* Context for non-blocking connects */ 80 struct channel_connect { 81 char *host; 82 int port; 83 struct addrinfo *ai, *aitop; 84 }; 85 86 /* Callbacks for mux channels back into client-specific code */ 87 typedef int mux_callback_fn(struct Channel *); 88 89 struct Channel { 90 int type; /* channel type/state */ 91 int self; /* my own channel identifier */ 92 int remote_id; /* channel identifier for remote peer */ 93 u_int istate; /* input from channel (state of receive half) */ 94 u_int ostate; /* output to channel (state of transmit half) */ 95 int flags; /* close sent/rcvd */ 96 int rfd; /* read fd */ 97 int wfd; /* write fd */ 98 int efd; /* extended fd */ 99 int sock; /* sock fd */ 100 int ctl_chan; /* control channel (multiplexed connections) */ 101 int isatty; /* rfd is a tty */ 102 int wfd_isatty; /* wfd is a tty */ 103 int client_tty; /* (client) TTY has been requested */ 104 int force_drain; /* force close on iEOF */ 105 int delayed; /* post-select handlers for newly created 106 * channels are delayed until the first call 107 * to a matching pre-select handler. 108 * this way post-select handlers are not 109 * accidenly called if a FD gets reused */ 110 Buffer input; /* data read from socket, to be sent over 111 * encrypted connection */ 112 Buffer output; /* data received over encrypted connection for 113 * send on socket */ 114 Buffer extended; 115 char *path; 116 /* path for unix domain sockets, or host name for forwards */ 117 int listening_port; /* port being listened for forwards */ 118 int host_port; /* remote port to connect for forwards */ 119 char *remote_name; /* remote hostname */ 120 121 u_int remote_window; 122 u_int remote_maxpacket; 123 u_int local_window; 124 u_int local_window_max; 125 u_int local_consumed; 126 u_int local_maxpacket; 127 int extended_usage; 128 int single_connection; 129 130 char *ctype; /* type */ 131 132 /* callback */ 133 channel_callback_fn *open_confirm; 134 void *open_confirm_ctx; 135 channel_callback_fn *detach_user; 136 int detach_close; 137 struct channel_confirms status_confirms; 138 139 /* filter */ 140 channel_infilter_fn *input_filter; 141 channel_outfilter_fn *output_filter; 142 void *filter_ctx; 143 channel_filter_cleanup_fn *filter_cleanup; 144 145 /* keep boundaries */ 146 int datagram; 147 148 /* non-blocking connect */ 149 struct channel_connect connect_ctx; 150 151 /* multiplexing protocol hook, called for each packet received */ 152 mux_callback_fn *mux_rcb; 153 void *mux_ctx; 154 }; 155 156 #define CHAN_EXTENDED_IGNORE 0 157 #define CHAN_EXTENDED_READ 1 158 #define CHAN_EXTENDED_WRITE 2 159 160 /* default window/packet sizes for tcp/x11-fwd-channel */ 161 #define CHAN_SES_PACKET_DEFAULT (32*1024) 162 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) 163 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 164 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 165 #define CHAN_X11_PACKET_DEFAULT (16*1024) 166 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 167 168 /* possible input states */ 169 #define CHAN_INPUT_OPEN 0 170 #define CHAN_INPUT_WAIT_DRAIN 1 171 #define CHAN_INPUT_WAIT_OCLOSE 2 172 #define CHAN_INPUT_CLOSED 3 173 174 /* possible output states */ 175 #define CHAN_OUTPUT_OPEN 0 176 #define CHAN_OUTPUT_WAIT_DRAIN 1 177 #define CHAN_OUTPUT_WAIT_IEOF 2 178 #define CHAN_OUTPUT_CLOSED 3 179 180 #define CHAN_CLOSE_SENT 0x01 181 #define CHAN_CLOSE_RCVD 0x02 182 #define CHAN_EOF_SENT 0x04 183 #define CHAN_EOF_RCVD 0x08 184 #define CHAN_LOCAL 0x10 185 186 #define CHAN_RBUF 16*1024 187 188 /* check whether 'efd' is still in use */ 189 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 190 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 191 (c->efd != -1 || \ 192 buffer_len(&c->extended) > 0)) 193 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 194 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 195 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 196 buffer_len(&c->extended) > 0)) 197 198 /* channel management */ 199 200 Channel *channel_by_id(int); 201 Channel *channel_lookup(int); 202 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 203 void channel_set_fds(int, int, int, int, int, int, int, u_int); 204 void channel_free(Channel *); 205 void channel_free_all(void); 206 void channel_stop_listening(void); 207 208 void channel_send_open(int); 209 void channel_request_start(int, char *, int); 210 void channel_register_cleanup(int, channel_callback_fn *, int); 211 void channel_register_open_confirm(int, channel_callback_fn *, void *); 212 void channel_register_filter(int, channel_infilter_fn *, 213 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 214 void channel_register_status_confirm(int, channel_confirm_cb *, 215 channel_confirm_abandon_cb *, void *); 216 void channel_cancel_cleanup(int); 217 int channel_close_fd(int *); 218 void channel_send_window_changes(void); 219 220 /* protocol handler */ 221 222 void channel_input_close(int, u_int32_t, void *); 223 void channel_input_close_confirmation(int, u_int32_t, void *); 224 void channel_input_data(int, u_int32_t, void *); 225 void channel_input_extended_data(int, u_int32_t, void *); 226 void channel_input_ieof(int, u_int32_t, void *); 227 void channel_input_oclose(int, u_int32_t, void *); 228 void channel_input_open_confirmation(int, u_int32_t, void *); 229 void channel_input_open_failure(int, u_int32_t, void *); 230 void channel_input_port_open(int, u_int32_t, void *); 231 void channel_input_window_adjust(int, u_int32_t, void *); 232 void channel_input_status_confirm(int, u_int32_t, void *); 233 234 /* file descriptor handling (read/write) */ 235 236 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); 237 void channel_after_select(fd_set *, fd_set *); 238 void channel_output_poll(void); 239 240 int channel_not_very_much_buffered_data(void); 241 void channel_close_all(void); 242 int channel_still_open(void); 243 char *channel_open_message(void); 244 int channel_find_open(void); 245 246 /* tcp forwarding */ 247 void channel_set_af(int af); 248 void channel_permit_all_opens(void); 249 void channel_add_permitted_opens(char *, int); 250 int channel_add_adm_permitted_opens(char *, int); 251 void channel_clear_permitted_opens(void); 252 void channel_clear_adm_permitted_opens(void); 253 void channel_print_adm_permitted_opens(void); 254 int channel_input_port_forward_request(int, int); 255 Channel *channel_connect_to(const char *, u_short, char *, char *); 256 Channel *channel_connect_stdio_fwd(const char*, u_short, int, int); 257 Channel *channel_connect_by_listen_address(u_short, char *, char *); 258 int channel_request_remote_forwarding(const char *, u_short, 259 const char *, u_short); 260 int channel_setup_local_fwd_listener(const char *, u_short, 261 const char *, u_short, int); 262 void channel_request_rforward_cancel(const char *host, u_short port); 263 int channel_setup_remote_fwd_listener(const char *, u_short, int *, int); 264 int channel_cancel_rport_listener(const char *, u_short); 265 266 /* x11 forwarding */ 267 268 int x11_connect_display(void); 269 int x11_create_display_inet(int, int, int, u_int *, int **); 270 void x11_input_open(int, u_int32_t, void *); 271 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 272 const char *); 273 void deny_input_open(int, u_int32_t, void *); 274 275 /* agent forwarding */ 276 277 void auth_request_forwarding(void); 278 279 /* channel close */ 280 281 int chan_is_dead(Channel *, int); 282 void chan_mark_dead(Channel *); 283 284 /* channel events */ 285 286 void chan_rcvd_oclose(Channel *); 287 void chan_rcvd_eow(Channel *); /* SSH2-only */ 288 void chan_read_failed(Channel *); 289 void chan_ibuf_empty(Channel *); 290 291 void chan_rcvd_ieof(Channel *); 292 void chan_write_failed(Channel *); 293 void chan_obuf_empty(Channel *); 294 295 #endif 296