1 /* 2 * Author: Tatu Ylonen <ylo@cs.hut.fi> 3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 4 * All rights reserved 5 * 6 * As far as I am concerned, the code I have written for this software 7 * can be used freely for any purpose. Any derived versions of this 8 * software must be clearly marked as such, and if the derived work is 9 * incompatible with the protocol description in the RFC file, it must be 10 * called by a name other than "ssh" or "Secure Shell". 11 */ 12 /* 13 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 /* 36 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. 37 */ 38 /* $OpenBSD: channels.h,v 1.70 2002/06/24 14:33:27 markus Exp $ */ 39 40 41 #ifndef _CHANNELS_H 42 #define _CHANNELS_H 43 44 #ifdef __cplusplus 45 extern "C" { 46 #endif 47 48 #include "buffer.h" 49 50 /* Definitions for channel types. */ 51 #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */ 52 #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */ 53 #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */ 54 #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */ 55 #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */ 56 #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */ 57 #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */ 58 #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */ 59 #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */ 60 #define SSH_CHANNEL_LARVAL 10 /* larval session */ 61 #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */ 62 #define SSH_CHANNEL_CONNECTING 12 63 #define SSH_CHANNEL_DYNAMIC 13 64 #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */ 65 #define SSH_CHANNEL_MAX_TYPE 15 66 67 #define SSH_CHANNEL_PATH_LEN 256 68 69 struct Channel; 70 typedef struct Channel Channel; 71 72 typedef void channel_callback_fn(int, void *); 73 typedef int channel_filter_fn(struct Channel *, char *, int); 74 75 struct Channel { 76 int type; /* channel type/state */ 77 int self; /* my own channel identifier */ 78 int remote_id; /* channel identifier for remote peer */ 79 u_int istate; /* input from channel (state of receive half) */ 80 u_int ostate; /* output to channel (state of transmit half) */ 81 int wait_for_exit; /* no close till after exit-status is sent */ 82 int flags; /* close sent/rcvd */ 83 int rfd; /* read fd */ 84 int wfd; /* write fd */ 85 int efd; /* extended fd */ 86 int sock; /* sock fd */ 87 int isatty; /* rfd is a tty */ 88 int wfd_isatty; /* wfd is a tty */ 89 int force_drain; /* force close on iEOF */ 90 int delayed; /* post-select handlers for newly created 91 * channels are delayed until the first call 92 * to a matching pre-select handler. 93 * this way post-select handlers are not 94 * accidenly called if a FD gets reused */ 95 Buffer input; /* data read from socket, to be sent over 96 * encrypted connection */ 97 Buffer output; /* data received over encrypted connection for 98 * send on socket */ 99 Buffer extended; 100 char path[SSH_CHANNEL_PATH_LEN]; 101 /* path for unix domain sockets, or host name for forwards */ 102 int listening_port; /* port being listened for forwards */ 103 int host_port; /* remote port to connect for forwards */ 104 char *remote_name; /* remote hostname */ 105 106 u_int remote_window; 107 u_int remote_maxpacket; 108 u_int local_window; 109 u_int local_window_max; 110 u_int local_consumed; 111 u_int local_maxpacket; 112 int extended_usage; 113 int single_connection; 114 115 char *ctype; /* type */ 116 117 /* callback */ 118 channel_callback_fn *confirm; 119 channel_callback_fn *detach_user; 120 121 /* filter */ 122 channel_filter_fn *input_filter; 123 }; 124 125 #define CHAN_EXTENDED_IGNORE 0 126 #define CHAN_EXTENDED_READ 1 127 #define CHAN_EXTENDED_WRITE 2 128 129 /* default window/packet sizes for tcp/x11-fwd-channel */ 130 #define CHAN_SES_PACKET_DEFAULT (32*1024) 131 #define CHAN_SES_WINDOW_DEFAULT (4*CHAN_SES_PACKET_DEFAULT) 132 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 133 #define CHAN_TCP_WINDOW_DEFAULT (4*CHAN_TCP_PACKET_DEFAULT) 134 #define CHAN_X11_PACKET_DEFAULT (16*1024) 135 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 136 137 /* possible input states */ 138 #define CHAN_INPUT_OPEN 0 139 #define CHAN_INPUT_WAIT_DRAIN 1 140 #define CHAN_INPUT_WAIT_OCLOSE 2 141 #define CHAN_INPUT_CLOSED 3 142 143 /* possible output states */ 144 #define CHAN_OUTPUT_OPEN 0 145 #define CHAN_OUTPUT_WAIT_DRAIN 1 146 #define CHAN_OUTPUT_WAIT_IEOF 2 147 #define CHAN_OUTPUT_CLOSED 3 148 149 /* 150 * Other channel flag bits are specific to each type of channel and are 151 * defined locally with the code that uses them. 152 */ 153 #define CHAN_CLOSE_SENT 0x01 154 #define CHAN_CLOSE_RCVD 0x02 155 #define CHAN_EOF_SENT 0x04 156 #define CHAN_EOF_RCVD 0x08 157 158 #define CHAN_RBUF 16*1024 159 160 /* check whether 'efd' is still in use */ 161 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 162 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 163 (c->efd != -1 || \ 164 buffer_len(&c->extended) > 0)) 165 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 166 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 167 ((c->efd != -1 && !(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD))) || \ 168 buffer_len(&c->extended) > 0)) 169 170 /* channel management */ 171 172 Channel *channel_lookup(int); 173 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 174 void channel_set_fds(int, int, int, int, int, int, u_int); 175 void channel_set_wait_for_exit(int, int); 176 void channel_free(Channel *); 177 void channel_free_all(void); 178 void channel_stop_listening(void); 179 180 void channel_send_open(int); 181 void channel_request_start(int, char *, int); 182 void channel_register_cleanup(int, channel_callback_fn *); 183 void channel_register_confirm(int, channel_callback_fn *); 184 void channel_register_filter(int, channel_filter_fn *); 185 void channel_cancel_cleanup(int); 186 int channel_close_fd(int *); 187 188 /* protocol handler */ 189 190 void channel_input_close(int, u_int32_t, void *); 191 void channel_input_close_confirmation(int, u_int32_t, void *); 192 void channel_input_data(int, u_int32_t, void *); 193 void channel_input_extended_data(int, u_int32_t, void *); 194 void channel_input_ieof(int, u_int32_t, void *); 195 void channel_input_oclose(int, u_int32_t, void *); 196 void channel_input_open_confirmation(int, u_int32_t, void *); 197 void channel_input_open_failure(int, u_int32_t, void *); 198 void channel_input_port_open(int, u_int32_t, void *); 199 void channel_input_window_adjust(int, u_int32_t, void *); 200 201 /* file descriptor handling (read/write) */ 202 203 void channel_prepare_select(fd_set **, fd_set **, int *, int*, int); 204 void channel_after_select(fd_set *, fd_set *); 205 void channel_output_poll(void); 206 207 int channel_not_very_much_buffered_data(void); 208 void channel_close_all(void); 209 int channel_still_open(void); 210 char *channel_open_message(void); 211 int channel_find_open(void); 212 213 /* tcp forwarding */ 214 void channel_set_af(int af); 215 void channel_permit_all_opens(void); 216 void channel_add_permitted_opens(char *, int); 217 void channel_clear_permitted_opens(void); 218 void channel_input_port_forward_request(int, int); 219 int channel_connect_to(const char *, u_short); 220 int channel_connect_by_listen_address(u_short); 221 int channel_request_remote_forwarding(const char *, u_short, 222 const char *, u_short); 223 int channel_setup_local_fwd_listener(const char *, u_short, 224 const char *, u_short, int); 225 void channel_request_rforward_cancel(const char *host, u_short port); 226 int channel_setup_remote_fwd_listener(const char *, u_short, int); 227 int channel_cancel_rport_listener(const char *, u_short); 228 229 /* x11 forwarding */ 230 231 int x11_connect_display(void); 232 int x11_create_display_inet(int, int, int, u_int *); 233 void x11_input_open(int, u_int32_t, void *); 234 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 235 const char *); 236 void deny_input_open(int, u_int32_t, void *); 237 238 /* agent forwarding */ 239 240 void auth_request_forwarding(void); 241 void auth_input_open_request(int, u_int32_t, void *); 242 243 /* channel close */ 244 245 int chan_is_dead(Channel *, int); 246 void chan_mark_dead(Channel *); 247 248 /* channel events */ 249 250 void chan_rcvd_oclose(Channel *); 251 void chan_rcvd_eow(Channel *); /* SSH2-only */ 252 void chan_read_failed(Channel *); 253 void chan_ibuf_empty(Channel *); 254 255 void chan_rcvd_ieof(Channel *); 256 void chan_write_failed(Channel *); 257 void chan_obuf_empty(Channel *); 258 259 #ifdef __cplusplus 260 } 261 #endif 262 263 #endif /* _CHANNELS_H */ 264