channels.h revision 126277
1/* $OpenBSD: channels.h,v 1.71 2003/09/23 20:41:11 markus 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 isatty; /* rfd is a tty */ 80 int wfd_isatty; /* wfd is a tty */ 81 int force_drain; /* force close on iEOF */ 82 int delayed; /* fdset hack */ 83 Buffer input; /* data read from socket, to be sent over 84 * encrypted connection */ 85 Buffer output; /* data received over encrypted connection for 86 * send on socket */ 87 Buffer extended; 88 char path[SSH_CHANNEL_PATH_LEN]; 89 /* path for unix domain sockets, or host name for forwards */ 90 int listening_port; /* port being listened for forwards */ 91 int host_port; /* remote port to connect for forwards */ 92 char *remote_name; /* remote hostname */ 93 94 u_int remote_window; 95 u_int remote_maxpacket; 96 u_int local_window; 97 u_int local_window_max; 98 u_int local_consumed; 99 u_int local_maxpacket; 100 int extended_usage; 101 int single_connection; 102 103 char *ctype; /* type */ 104 105 /* callback */ 106 channel_callback_fn *confirm; 107 channel_callback_fn *detach_user; 108 109 /* filter */ 110 channel_filter_fn *input_filter; 111}; 112 113#define CHAN_EXTENDED_IGNORE 0 114#define CHAN_EXTENDED_READ 1 115#define CHAN_EXTENDED_WRITE 2 116 117/* default window/packet sizes for tcp/x11-fwd-channel */ 118#define CHAN_SES_PACKET_DEFAULT (32*1024) 119#define CHAN_SES_WINDOW_DEFAULT (4*CHAN_SES_PACKET_DEFAULT) 120#define CHAN_TCP_PACKET_DEFAULT (32*1024) 121#define CHAN_TCP_WINDOW_DEFAULT (4*CHAN_TCP_PACKET_DEFAULT) 122#define CHAN_X11_PACKET_DEFAULT (16*1024) 123#define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 124 125/* possible input states */ 126#define CHAN_INPUT_OPEN 0 127#define CHAN_INPUT_WAIT_DRAIN 1 128#define CHAN_INPUT_WAIT_OCLOSE 2 129#define CHAN_INPUT_CLOSED 3 130 131/* possible output states */ 132#define CHAN_OUTPUT_OPEN 0 133#define CHAN_OUTPUT_WAIT_DRAIN 1 134#define CHAN_OUTPUT_WAIT_IEOF 2 135#define CHAN_OUTPUT_CLOSED 3 136 137#define CHAN_CLOSE_SENT 0x01 138#define CHAN_CLOSE_RCVD 0x02 139#define CHAN_EOF_SENT 0x04 140#define CHAN_EOF_RCVD 0x08 141 142/* check whether 'efd' is still in use */ 143#define CHANNEL_EFD_INPUT_ACTIVE(c) \ 144 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 145 (c->efd != -1 || \ 146 buffer_len(&c->extended) > 0)) 147#define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 148 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 149 ((c->efd != -1 && !(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD))) || \ 150 buffer_len(&c->extended) > 0)) 151 152/* channel management */ 153 154Channel *channel_lookup(int); 155Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 156void channel_set_fds(int, int, int, int, int, int, u_int); 157void channel_free(Channel *); 158void channel_free_all(void); 159void channel_stop_listening(void); 160 161void channel_send_open(int); 162void channel_request_start(int, char *, int); 163void channel_register_cleanup(int, channel_callback_fn *); 164void channel_register_confirm(int, channel_callback_fn *); 165void channel_register_filter(int, channel_filter_fn *); 166void channel_cancel_cleanup(int); 167int channel_close_fd(int *); 168 169/* protocol handler */ 170 171void channel_input_close(int, u_int32_t, void *); 172void channel_input_close_confirmation(int, u_int32_t, void *); 173void channel_input_data(int, u_int32_t, void *); 174void channel_input_extended_data(int, u_int32_t, void *); 175void channel_input_ieof(int, u_int32_t, void *); 176void channel_input_oclose(int, u_int32_t, void *); 177void channel_input_open_confirmation(int, u_int32_t, void *); 178void channel_input_open_failure(int, u_int32_t, void *); 179void channel_input_port_open(int, u_int32_t, void *); 180void channel_input_window_adjust(int, u_int32_t, void *); 181 182/* file descriptor handling (read/write) */ 183 184void channel_prepare_select(fd_set **, fd_set **, int *, int*, int); 185void channel_after_select(fd_set *, fd_set *); 186void channel_output_poll(void); 187 188int channel_not_very_much_buffered_data(void); 189void channel_close_all(void); 190int channel_still_open(void); 191char *channel_open_message(void); 192int channel_find_open(void); 193 194/* tcp forwarding */ 195void channel_set_af(int af); 196void channel_permit_all_opens(void); 197void channel_add_permitted_opens(char *, int); 198void channel_clear_permitted_opens(void); 199void channel_input_port_forward_request(int, int); 200int channel_connect_to(const char *, u_short); 201int channel_connect_by_listen_address(u_short); 202void channel_request_remote_forwarding(u_short, const char *, u_short); 203int channel_setup_local_fwd_listener(u_short, const char *, u_short, int); 204int channel_setup_remote_fwd_listener(const char *, u_short, int); 205 206/* x11 forwarding */ 207 208int x11_connect_display(void); 209int x11_create_display_inet(int, int, int, u_int *); 210void x11_input_open(int, u_int32_t, void *); 211void x11_request_forwarding_with_spoofing(int, const char *, const char *); 212void deny_input_open(int, u_int32_t, void *); 213 214/* agent forwarding */ 215 216void auth_request_forwarding(void); 217 218/* channel close */ 219 220int chan_is_dead(Channel *, int); 221void chan_mark_dead(Channel *); 222 223/* channel events */ 224 225void chan_rcvd_oclose(Channel *); 226void chan_read_failed(Channel *); 227void chan_ibuf_empty(Channel *); 228 229void chan_rcvd_ieof(Channel *); 230void chan_write_failed(Channel *); 231void chan_obuf_empty(Channel *); 232 233#endif 234