1 /* $OpenBSD: channels.h,v 1.79 2005/07/17 06:49:04 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 #include "buffer.h" 42 43 /* Definitions for channel types. */ 44 #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */ 45 #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */ 46 #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */ 47 #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */ 48 #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */ 49 #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */ 50 #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */ 51 #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */ 52 #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */ 53 #define SSH_CHANNEL_LARVAL 10 /* larval session */ 54 #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */ 55 #define SSH_CHANNEL_CONNECTING 12 56 #define SSH_CHANNEL_DYNAMIC 13 57 #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */ 58 #define SSH_CHANNEL_MAX_TYPE 15 59 60 #define SSH_CHANNEL_PATH_LEN 256 61 62 struct Channel; 63 typedef struct Channel Channel; 64 65 typedef void channel_callback_fn(int, void *); 66 typedef int channel_filter_fn(struct Channel *, char *, int); 67 68 struct Channel { 69 int type; /* channel type/state */ 70 int self; /* my own channel identifier */ 71 int remote_id; /* channel identifier for remote peer */ 72 u_int istate; /* input from channel (state of receive half) */ 73 u_int ostate; /* output to channel (state of transmit half) */ 74 int flags; /* close sent/rcvd */ 75 int rfd; /* read fd */ 76 int wfd; /* write fd */ 77 int efd; /* extended fd */ 78 int sock; /* sock fd */ 79 int ctl_fd; /* control fd (client sharing) */ 80 int isatty; /* rfd is a tty */ 81 int wfd_isatty; /* wfd is a tty */ 82 int client_tty; /* (client) TTY has been requested */ 83 int force_drain; /* force close on iEOF */ 84 int delayed; /* fdset hack */ 85 Buffer input; /* data read from socket, to be sent over 86 * encrypted connection */ 87 Buffer output; /* data received over encrypted connection for 88 * send on socket */ 89 Buffer extended; 90 char path[SSH_CHANNEL_PATH_LEN]; 91 /* path for unix domain sockets, or host name for forwards */ 92 int listening_port; /* port being listened for forwards */ 93 int host_port; /* remote port to connect for forwards */ 94 char *remote_name; /* remote hostname */ 95 96 u_int remote_window; 97 u_int remote_maxpacket; 98 u_int local_window; 99 u_int local_window_max; 100 u_int local_consumed; 101 u_int local_maxpacket; 102 int extended_usage; 103 int single_connection; 104 105 char *ctype; /* type */ 106 107 /* callback */ 108 channel_callback_fn *confirm; 109 channel_callback_fn *detach_user; 110 void *confirm_ctx; 111 112 /* filter */ 113 channel_filter_fn *input_filter; 114 }; 115 116 #define CHAN_EXTENDED_IGNORE 0 117 #define CHAN_EXTENDED_READ 1 118 #define CHAN_EXTENDED_WRITE 2 119 120 /* default window/packet sizes for tcp/x11-fwd-channel */ 121 #define CHAN_SES_PACKET_DEFAULT (32*1024) 122 #define CHAN_SES_WINDOW_DEFAULT (4*CHAN_SES_PACKET_DEFAULT) 123 #define CHAN_TCP_PACKET_DEFAULT (32*1024) 124 #define CHAN_TCP_WINDOW_DEFAULT (4*CHAN_TCP_PACKET_DEFAULT) 125 #define CHAN_X11_PACKET_DEFAULT (16*1024) 126 #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 127 128 /* possible input states */ 129 #define CHAN_INPUT_OPEN 0 130 #define CHAN_INPUT_WAIT_DRAIN 1 131 #define CHAN_INPUT_WAIT_OCLOSE 2 132 #define CHAN_INPUT_CLOSED 3 133 134 /* possible output states */ 135 #define CHAN_OUTPUT_OPEN 0 136 #define CHAN_OUTPUT_WAIT_DRAIN 1 137 #define CHAN_OUTPUT_WAIT_IEOF 2 138 #define CHAN_OUTPUT_CLOSED 3 139 140 #define CHAN_CLOSE_SENT 0x01 141 #define CHAN_CLOSE_RCVD 0x02 142 #define CHAN_EOF_SENT 0x04 143 #define CHAN_EOF_RCVD 0x08 144 145 /* check whether 'efd' is still in use */ 146 #define CHANNEL_EFD_INPUT_ACTIVE(c) \ 147 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 148 (c->efd != -1 || \ 149 buffer_len(&c->extended) > 0)) 150 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 151 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 152 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 153 buffer_len(&c->extended) > 0)) 154 155 /* channel management */ 156 157 Channel *channel_lookup(int); 158 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 159 void channel_set_fds(int, int, int, int, int, int, u_int); 160 void channel_free(Channel *); 161 void channel_free_all(void); 162 void channel_stop_listening(void); 163 164 void channel_send_open(int); 165 void channel_request_start(int, char *, int); 166 void channel_register_cleanup(int, channel_callback_fn *); 167 void channel_register_confirm(int, channel_callback_fn *, void *); 168 void channel_register_filter(int, channel_filter_fn *); 169 void channel_cancel_cleanup(int); 170 int channel_close_fd(int *); 171 void channel_send_window_changes(void); 172 173 /* protocol handler */ 174 175 void channel_input_close(int, u_int32_t, void *); 176 void channel_input_close_confirmation(int, u_int32_t, void *); 177 void channel_input_data(int, u_int32_t, void *); 178 void channel_input_extended_data(int, u_int32_t, void *); 179 void channel_input_ieof(int, u_int32_t, void *); 180 void channel_input_oclose(int, u_int32_t, void *); 181 void channel_input_open_confirmation(int, u_int32_t, void *); 182 void channel_input_open_failure(int, u_int32_t, void *); 183 void channel_input_port_open(int, u_int32_t, void *); 184 void channel_input_window_adjust(int, u_int32_t, void *); 185 186 /* file descriptor handling (read/write) */ 187 188 void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); 189 void channel_after_select(fd_set *, fd_set *); 190 void channel_output_poll(void); 191 192 int channel_not_very_much_buffered_data(void); 193 void channel_close_all(void); 194 int channel_still_open(void); 195 char *channel_open_message(void); 196 int channel_find_open(void); 197 198 /* tcp forwarding */ 199 void channel_set_af(int af); 200 void channel_permit_all_opens(void); 201 void channel_add_permitted_opens(char *, int); 202 void channel_clear_permitted_opens(void); 203 void channel_input_port_forward_request(int, int); 204 int channel_connect_to(const char *, u_short); 205 int channel_connect_by_listen_address(u_short); 206 void channel_request_remote_forwarding(const char *, u_short, 207 const char *, u_short); 208 int channel_setup_local_fwd_listener(const char *, u_short, 209 const char *, u_short, int); 210 void channel_request_rforward_cancel(const char *host, u_short port); 211 int channel_setup_remote_fwd_listener(const char *, u_short, int); 212 int channel_cancel_rport_listener(const char *, u_short); 213 214 /* x11 forwarding */ 215 216 int x11_connect_display(void); 217 int x11_create_display_inet(int, int, int, u_int *, int **); 218 void x11_input_open(int, u_int32_t, void *); 219 void x11_request_forwarding_with_spoofing(int, const char *, const char *, 220 const char *); 221 void deny_input_open(int, u_int32_t, void *); 222 223 /* agent forwarding */ 224 225 void auth_request_forwarding(void); 226 227 /* channel close */ 228 229 int chan_is_dead(Channel *, int); 230 void chan_mark_dead(Channel *); 231 232 /* channel events */ 233 234 void chan_rcvd_oclose(Channel *); 235 void chan_read_failed(Channel *); 236 void chan_ibuf_empty(Channel *); 237 238 void chan_rcvd_ieof(Channel *); 239 void chan_write_failed(Channel *); 240 void chan_obuf_empty(Channel *); 241 242 #endif 243