1 /* $OpenBSD: channels.h,v 1.98 2009/02/12 03:00:56 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_MAX_TYPE 15 57 58 struct Channel; 59 typedef struct Channel Channel; 60 61 typedef void channel_callback_fn(int, void *); 62 typedef int channel_infilter_fn(struct Channel *, char *, int); 63 typedef void channel_filter_cleanup_fn(int, void *); 64 typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); 65 66 /* Channel success/failure callbacks */ 67 typedef void channel_confirm_cb(int, struct Channel *, void *); 68 typedef void channel_confirm_abandon_cb(struct Channel *, void *); 69 struct channel_confirm { 70 TAILQ_ENTRY(channel_confirm) entry; 71 channel_confirm_cb *cb; 72 channel_confirm_abandon_cb *abandon_cb; 73 void *ctx; 74 }; 75 TAILQ_HEAD(channel_confirms, channel_confirm); 76 77 /* Context for non-blocking connects */ 78 struct channel_connect { 79 char *host; 80 int port; 81 struct addrinfo *ai, *aitop; 82 }; 83 84 struct Channel { 85 int type; /* channel type/state */ 86 int self; /* my own channel identifier */ 87 int remote_id; /* channel identifier for remote peer */ 88 u_int istate; /* input from channel (state of receive half) */ 89 u_int ostate; /* output to channel (state of transmit half) */ 90 int flags; /* close sent/rcvd */ 91 int rfd; /* read fd */ 92 int wfd; /* write fd */ 93 int efd; /* extended fd */ 94 int sock; /* sock fd */ 95 int ctl_fd; /* control fd (client sharing) */ 96 int isatty; /* rfd is a tty */ 97 int wfd_isatty; /* wfd is a tty */ 98 int client_tty; /* (client) TTY has been requested */ 99 int force_drain; /* force close on iEOF */ 100 int delayed; /* fdset hack */ 101 Buffer input; /* data read from socket, to be sent over 102 * encrypted connection */ 103 Buffer output; /* data received over encrypted connection for 104 * send on socket */ 105 Buffer extended; 106 char *path; 107 /* path for unix domain sockets, or host name for forwards */ 108 int listening_port; /* port being listened for forwards */ 109 int host_port; /* remote port to connect for forwards */ 110 char *remote_name; /* remote hostname */ 111 112 u_int remote_window; 113 u_int remote_maxpacket; 114 u_int local_window; 115 u_int local_window_max; 116 u_int local_consumed; 117 u_int local_maxpacket; 118 int extended_usage; 119 int single_connection; 120 121 char *ctype; /* type */ 122 123 /* callback */ 124 channel_callback_fn *open_confirm; 125 void *open_confirm_ctx; 126 channel_callback_fn *detach_user; 127 int detach_close; 128 struct channel_confirms status_confirms; 129 130 /* filter */ 131 channel_infilter_fn *input_filter; 132 channel_outfilter_fn *output_filter; 133 void *filter_ctx; 134 channel_filter_cleanup_fn *filter_cleanup; 135 136 /* keep boundaries */ 137 int datagram; 138 139 /* non-blocking connect */ 140 struct channel_connect connect_ctx; 141 }; 142 143 #define CHAN_EXTENDED_IGNORE 0 144 #define CHAN_EXTENDED_READ 1 145 #define CHAN_EXTENDED_WRITE 2 146 147 /* default window/packet sizes for tcp/x11-fwd-channel */ 148 #define CHAN_SES_PACKET_DEFAULT (32*1024) 149 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) 150 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 151 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 152 #define CHAN_X11_PACKET_DEFAULT (16*1024) 153 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 154 155 /* possible input states */ 156 #define CHAN_INPUT_OPEN 0 157 #define CHAN_INPUT_WAIT_DRAIN 1 158 #define CHAN_INPUT_WAIT_OCLOSE 2 159 #define CHAN_INPUT_CLOSED 3 160 161 /* possible output states */ 162 #define CHAN_OUTPUT_OPEN 0 163 #define CHAN_OUTPUT_WAIT_DRAIN 1 164 #define CHAN_OUTPUT_WAIT_IEOF 2 165 #define CHAN_OUTPUT_CLOSED 3 166 167 #define CHAN_CLOSE_SENT 0x01 168 #define CHAN_CLOSE_RCVD 0x02 169 #define CHAN_EOF_SENT 0x04 170 #define CHAN_EOF_RCVD 0x08 171 172 #define CHAN_RBUF 16*1024 173 174 /* check whether 'efd' is still in use */ 175 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 176 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 177 (c->efd != -1 || \ 178 buffer_len(&c->extended) > 0)) 179 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 180 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 181 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 182 buffer_len(&c->extended) > 0)) 183 184 /* channel management */ 185 186 Channel *channel_by_id(int); 187 Channel *channel_lookup(int); 188 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 189 void channel_set_fds(int, int, int, int, int, int, int, u_int); 190 void channel_free(Channel *); 191 void channel_free_all(void); 192 void channel_stop_listening(void); 193 194 void channel_send_open(int); 195 void channel_request_start(int, char *, int); 196 void channel_register_cleanup(int, channel_callback_fn *, int); 197 void channel_register_open_confirm(int, channel_callback_fn *, void *); 198 void channel_register_filter(int, channel_infilter_fn *, 199 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 200 void channel_register_status_confirm(int, channel_confirm_cb *, 201 channel_confirm_abandon_cb *, void *); 202 void channel_cancel_cleanup(int); 203 int channel_close_fd(int *); 204 void channel_send_window_changes(void); 205 206 /* protocol handler */ 207 208 void channel_input_close(int, u_int32_t, void *); 209 void channel_input_close_confirmation(int, u_int32_t, void *); 210 void channel_input_data(int, u_int32_t, void *); 211 void channel_input_extended_data(int, u_int32_t, void *); 212 void channel_input_ieof(int, u_int32_t, void *); 213 void channel_input_oclose(int, u_int32_t, void *); 214 void channel_input_open_confirmation(int, u_int32_t, void *); 215 void channel_input_open_failure(int, u_int32_t, void *); 216 void channel_input_port_open(int, u_int32_t, void *); 217 void channel_input_window_adjust(int, u_int32_t, void *); 218 void channel_input_status_confirm(int, u_int32_t, void *); 219 220 /* file descriptor handling (read/write) */ 221 222 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); 223 void channel_after_select(fd_set *, fd_set *); 224 void channel_output_poll(void); 225 226 int channel_not_very_much_buffered_data(void); 227 void channel_close_all(void); 228 int channel_still_open(void); 229 char *channel_open_message(void); 230 int channel_find_open(void); 231 232 /* tcp forwarding */ 233 void channel_set_af(int af); 234 void channel_permit_all_opens(void); 235 void channel_add_permitted_opens(char *, int); 236 int channel_add_adm_permitted_opens(char *, int); 237 void channel_clear_permitted_opens(void); 238 void channel_clear_adm_permitted_opens(void); 239 void channel_print_adm_permitted_opens(void); 240 int channel_input_port_forward_request(int, int); 241 Channel *channel_connect_to(const char *, u_short, char *, char *); 242 Channel *channel_connect_by_listen_address(u_short, char *, char *); 243 int channel_request_remote_forwarding(const char *, u_short, 244 const char *, u_short); 245 int channel_setup_local_fwd_listener(const char *, u_short, 246 const char *, u_short, int); 247 void channel_request_rforward_cancel(const char *host, u_short port); 248 int channel_setup_remote_fwd_listener(const char *, u_short, int *, int); 249 int channel_cancel_rport_listener(const char *, u_short); 250 251 /* x11 forwarding */ 252 253 int x11_connect_display(void); 254 int x11_create_display_inet(int, int, int, u_int *, int **); 255 void x11_input_open(int, u_int32_t, void *); 256 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 257 const char *); 258 void deny_input_open(int, u_int32_t, void *); 259 260 /* agent forwarding */ 261 262 void auth_request_forwarding(void); 263 264 /* channel close */ 265 266 int chan_is_dead(Channel *, int); 267 void chan_mark_dead(Channel *); 268 269 /* channel events */ 270 271 void chan_rcvd_oclose(Channel *); 272 void chan_rcvd_eow(Channel *); /* SSH2-only */ 273 void chan_read_failed(Channel *); 274 void chan_ibuf_empty(Channel *); 275 276 void chan_rcvd_ieof(Channel *); 277 void chan_write_failed(Channel *); 278 void chan_obuf_empty(Channel *); 279 280 #endif 281