channels.h revision 137019
1/* $OpenBSD: channels.h,v 1.74 2004/08/11 21:43:04 avsm 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 62struct Channel; 63typedef struct Channel Channel; 64 65typedef void channel_callback_fn(int, void *); 66typedef int channel_filter_fn(struct Channel *, char *, int); 67 68struct 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 force_drain; /* force close on iEOF */ 83 int delayed; /* fdset hack */ 84 Buffer input; /* data read from socket, to be sent over 85 * encrypted connection */ 86 Buffer output; /* data received over encrypted connection for 87 * send on socket */ 88 Buffer extended; 89 char path[SSH_CHANNEL_PATH_LEN]; 90 /* path for unix domain sockets, or host name for forwards */ 91 int listening_port; /* port being listened for forwards */ 92 int host_port; /* remote port to connect for forwards */ 93 char *remote_name; /* remote hostname */ 94 95 u_int remote_window; 96 u_int remote_maxpacket; 97 u_int local_window; 98 u_int local_window_max; 99 u_int local_consumed; 100 u_int local_maxpacket; 101 int extended_usage; 102 int single_connection; 103 104 char *ctype; /* type */ 105 106 /* callback */ 107 channel_callback_fn *confirm; 108 channel_callback_fn *detach_user; 109 void *confirm_ctx; 110 111 /* filter */ 112 channel_filter_fn *input_filter; 113}; 114 115#define CHAN_EXTENDED_IGNORE 0 116#define CHAN_EXTENDED_READ 1 117#define CHAN_EXTENDED_WRITE 2 118 119/* default window/packet sizes for tcp/x11-fwd-channel */ 120#define CHAN_SES_PACKET_DEFAULT (32*1024) 121#define CHAN_SES_WINDOW_DEFAULT (4*CHAN_SES_PACKET_DEFAULT) 122#define CHAN_TCP_PACKET_DEFAULT (32*1024) 123#define CHAN_TCP_WINDOW_DEFAULT (4*CHAN_TCP_PACKET_DEFAULT) 124#define CHAN_X11_PACKET_DEFAULT (16*1024) 125#define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 126 127/* possible input states */ 128#define CHAN_INPUT_OPEN 0 129#define CHAN_INPUT_WAIT_DRAIN 1 130#define CHAN_INPUT_WAIT_OCLOSE 2 131#define CHAN_INPUT_CLOSED 3 132 133/* possible output states */ 134#define CHAN_OUTPUT_OPEN 0 135#define CHAN_OUTPUT_WAIT_DRAIN 1 136#define CHAN_OUTPUT_WAIT_IEOF 2 137#define CHAN_OUTPUT_CLOSED 3 138 139#define CHAN_CLOSE_SENT 0x01 140#define CHAN_CLOSE_RCVD 0x02 141#define CHAN_EOF_SENT 0x04 142#define CHAN_EOF_RCVD 0x08 143 144/* check whether 'efd' is still in use */ 145#define CHANNEL_EFD_INPUT_ACTIVE(c) \ 146 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 147 (c->efd != -1 || \ 148 buffer_len(&c->extended) > 0)) 149#define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 150 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 151 ((c->efd != -1 && !(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD))) || \ 152 buffer_len(&c->extended) > 0)) 153 154/* channel management */ 155 156Channel *channel_lookup(int); 157Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 158void channel_set_fds(int, int, int, int, int, int, u_int); 159void channel_free(Channel *); 160void channel_free_all(void); 161void channel_stop_listening(void); 162 163void channel_send_open(int); 164void channel_request_start(int, char *, int); 165void channel_register_cleanup(int, channel_callback_fn *); 166void channel_register_confirm(int, channel_callback_fn *, void *); 167void channel_register_filter(int, channel_filter_fn *); 168void channel_cancel_cleanup(int); 169int channel_close_fd(int *); 170void channel_send_window_changes(void); 171 172/* protocol handler */ 173 174void channel_input_close(int, u_int32_t, void *); 175void channel_input_close_confirmation(int, u_int32_t, void *); 176void channel_input_data(int, u_int32_t, void *); 177void channel_input_extended_data(int, u_int32_t, void *); 178void channel_input_ieof(int, u_int32_t, void *); 179void channel_input_oclose(int, u_int32_t, void *); 180void channel_input_open_confirmation(int, u_int32_t, void *); 181void channel_input_open_failure(int, u_int32_t, void *); 182void channel_input_port_open(int, u_int32_t, void *); 183void channel_input_window_adjust(int, u_int32_t, void *); 184 185/* file descriptor handling (read/write) */ 186 187void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); 188void channel_after_select(fd_set *, fd_set *); 189void channel_output_poll(void); 190 191int channel_not_very_much_buffered_data(void); 192void channel_close_all(void); 193int channel_still_open(void); 194char *channel_open_message(void); 195int channel_find_open(void); 196 197/* tcp forwarding */ 198void channel_set_af(int af); 199void channel_permit_all_opens(void); 200void channel_add_permitted_opens(char *, int); 201void channel_clear_permitted_opens(void); 202void channel_input_port_forward_request(int, int); 203int channel_connect_to(const char *, u_short); 204int channel_connect_by_listen_address(u_short); 205void channel_request_remote_forwarding(u_short, const char *, u_short); 206void channel_request_rforward_cancel(u_short port); 207int channel_setup_local_fwd_listener(u_short, const char *, u_short, int); 208int channel_setup_remote_fwd_listener(const char *, u_short, int); 209int channel_cancel_rport_listener(const char *, u_short); 210 211/* x11 forwarding */ 212 213int x11_connect_display(void); 214int x11_create_display_inet(int, int, int, u_int *); 215void x11_input_open(int, u_int32_t, void *); 216void x11_request_forwarding_with_spoofing(int, const char *, const char *); 217void deny_input_open(int, u_int32_t, void *); 218 219/* agent forwarding */ 220 221void auth_request_forwarding(void); 222 223/* channel close */ 224 225int chan_is_dead(Channel *, int); 226void chan_mark_dead(Channel *); 227 228/* channel events */ 229 230void chan_rcvd_oclose(Channel *); 231void chan_read_failed(Channel *); 232void chan_ibuf_empty(Channel *); 233 234void chan_rcvd_ieof(Channel *); 235void chan_write_failed(Channel *); 236void chan_obuf_empty(Channel *); 237 238#endif 239