1 /* $OpenBSD: channels.h,v 1.96 2008/06/15 20:06:26 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 #define SSH_CHANNEL_PATH_LEN 256 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 struct Channel { 87 int type; /* channel type/state */ 88 int self; /* my own channel identifier */ 89 int remote_id; /* channel identifier for remote peer */ 90 u_int istate; /* input from channel (state of receive half) */ 91 u_int ostate; /* output to channel (state of transmit half) */ 92 int flags; /* close sent/rcvd */ 93 int rfd; /* read fd */ 94 int wfd; /* write fd */ 95 int efd; /* extended fd */ 96 int sock; /* sock fd */ 97 int ctl_fd; /* control fd (client sharing) */ 98 int isatty; /* rfd is a tty */ 99 int wfd_isatty; /* wfd is a tty */ 100 int client_tty; /* (client) TTY has been requested */ 101 int force_drain; /* force close on iEOF */ 102 int delayed; /* fdset hack */ 103 Buffer input; /* data read from socket, to be sent over 104 * encrypted connection */ 105 Buffer output; /* data received over encrypted connection for 106 * send on socket */ 107 Buffer extended; 108 char path[SSH_CHANNEL_PATH_LEN]; 109 /* path for unix domain sockets, or host name for forwards */ 110 int listening_port; /* port being listened for forwards */ 111 int host_port; /* remote port to connect for forwards */ 112 char *remote_name; /* remote hostname */ 113 114 u_int remote_window; 115 u_int remote_maxpacket; 116 u_int local_window; 117 u_int local_window_max; 118 u_int local_consumed; 119 u_int local_maxpacket; 120 int extended_usage; 121 int single_connection; 122 123 char *ctype; /* type */ 124 125 /* callback */ 126 channel_callback_fn *open_confirm; 127 void *open_confirm_ctx; 128 channel_callback_fn *detach_user; 129 int detach_close; 130 struct channel_confirms status_confirms; 131 132 /* filter */ 133 channel_infilter_fn *input_filter; 134 channel_outfilter_fn *output_filter; 135 void *filter_ctx; 136 channel_filter_cleanup_fn *filter_cleanup; 137 138 /* keep boundaries */ 139 int datagram; 140 141 /* non-blocking connect */ 142 struct channel_connect connect_ctx; 143 }; 144 145 #define CHAN_EXTENDED_IGNORE 0 146 #define CHAN_EXTENDED_READ 1 147 #define CHAN_EXTENDED_WRITE 2 148 149 /* default window/packet sizes for tcp/x11-fwd-channel */ 150 #define CHAN_SES_PACKET_DEFAULT (32*1024) 151 #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT) 152 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 153 #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT) 154 #define CHAN_X11_PACKET_DEFAULT (16*1024) 155 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 156 157 /* possible input states */ 158 #define CHAN_INPUT_OPEN 0 159 #define CHAN_INPUT_WAIT_DRAIN 1 160 #define CHAN_INPUT_WAIT_OCLOSE 2 161 #define CHAN_INPUT_CLOSED 3 162 163 /* possible output states */ 164 #define CHAN_OUTPUT_OPEN 0 165 #define CHAN_OUTPUT_WAIT_DRAIN 1 166 #define CHAN_OUTPUT_WAIT_IEOF 2 167 #define CHAN_OUTPUT_CLOSED 3 168 169 #define CHAN_CLOSE_SENT 0x01 170 #define CHAN_CLOSE_RCVD 0x02 171 #define CHAN_EOF_SENT 0x04 172 #define CHAN_EOF_RCVD 0x08 173 174 #define CHAN_RBUF 16*1024 175 176 /* check whether 'efd' is still in use */ 177 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 178 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 179 (c->efd != -1 || \ 180 buffer_len(&c->extended) > 0)) 181 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 182 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 183 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 184 buffer_len(&c->extended) > 0)) 185 186 /* channel management */ 187 188 Channel *channel_by_id(int); 189 Channel *channel_lookup(int); 190 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 191 void channel_set_fds(int, int, int, int, int, int, int, u_int); 192 void channel_free(Channel *); 193 void channel_free_all(void); 194 void channel_stop_listening(void); 195 196 void channel_send_open(int); 197 void channel_request_start(int, char *, int); 198 void channel_register_cleanup(int, channel_callback_fn *, int); 199 void channel_register_open_confirm(int, channel_callback_fn *, void *); 200 void channel_register_filter(int, channel_infilter_fn *, 201 channel_outfilter_fn *, channel_filter_cleanup_fn *, void *); 202 void channel_register_status_confirm(int, channel_confirm_cb *, 203 channel_confirm_abandon_cb *, void *); 204 void channel_cancel_cleanup(int); 205 int channel_close_fd(int *); 206 void channel_send_window_changes(void); 207 208 /* protocol handler */ 209 210 void channel_input_close(int, u_int32_t, void *); 211 void channel_input_close_confirmation(int, u_int32_t, void *); 212 void channel_input_data(int, u_int32_t, void *); 213 void channel_input_extended_data(int, u_int32_t, void *); 214 void channel_input_ieof(int, u_int32_t, void *); 215 void channel_input_oclose(int, u_int32_t, void *); 216 void channel_input_open_confirmation(int, u_int32_t, void *); 217 void channel_input_open_failure(int, u_int32_t, void *); 218 void channel_input_port_open(int, u_int32_t, void *); 219 void channel_input_window_adjust(int, u_int32_t, void *); 220 void channel_input_status_confirm(int, u_int32_t, void *); 221 222 /* file descriptor handling (read/write) */ 223 224 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); 225 void channel_after_select(fd_set *, fd_set *); 226 void channel_output_poll(void); 227 228 int channel_not_very_much_buffered_data(void); 229 void channel_close_all(void); 230 int channel_still_open(void); 231 char *channel_open_message(void); 232 int channel_find_open(void); 233 234 /* tcp forwarding */ 235 void channel_set_af(int af); 236 void channel_permit_all_opens(void); 237 void channel_add_permitted_opens(char *, int); 238 int channel_add_adm_permitted_opens(char *, int); 239 void channel_clear_permitted_opens(void); 240 void channel_clear_adm_permitted_opens(void); 241 void channel_print_adm_permitted_opens(void); 242 int channel_input_port_forward_request(int, int); 243 Channel *channel_connect_to(const char *, u_short, char *, char *); 244 Channel *channel_connect_by_listen_address(u_short, char *, char *); 245 int channel_request_remote_forwarding(const char *, u_short, 246 const char *, u_short); 247 int channel_setup_local_fwd_listener(const char *, u_short, 248 const char *, u_short, int); 249 void channel_request_rforward_cancel(const char *host, u_short port); 250 int channel_setup_remote_fwd_listener(const char *, u_short, int); 251 int channel_cancel_rport_listener(const char *, u_short); 252 253 /* x11 forwarding */ 254 255 int x11_connect_display(void); 256 int x11_create_display_inet(int, int, int, u_int *, int **); 257 void x11_input_open(int, u_int32_t, void *); 258 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 259 const char *); 260 void deny_input_open(int, u_int32_t, void *); 261 262 /* agent forwarding */ 263 264 void auth_request_forwarding(void); 265 266 /* channel close */ 267 268 int chan_is_dead(Channel *, int); 269 void chan_mark_dead(Channel *); 270 271 /* channel events */ 272 273 void chan_rcvd_oclose(Channel *); 274 void chan_rcvd_eow(Channel *); /* SSH2-only */ 275 void chan_read_failed(Channel *); 276 void chan_ibuf_empty(Channel *); 277 278 void chan_rcvd_ieof(Channel *); 279 void chan_write_failed(Channel *); 280 void chan_obuf_empty(Channel *); 281 282 #endif 283