channels.h revision 181110
1/* $OpenBSD: channels.h,v 1.88 2006/08/03 03:34:42 deraadt 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 60struct Channel; 61typedef struct Channel Channel; 62 63typedef void channel_callback_fn(int, void *); 64typedef int channel_infilter_fn(struct Channel *, char *, int); 65typedef u_char *channel_outfilter_fn(struct Channel *, u_char **, u_int *); 66 67struct Channel { 68 int type; /* channel type/state */ 69 int self; /* my own channel identifier */ 70 int remote_id; /* channel identifier for remote peer */ 71 u_int istate; /* input from channel (state of receive half) */ 72 u_int ostate; /* output to channel (state of transmit half) */ 73 int flags; /* close sent/rcvd */ 74 int rfd; /* read fd */ 75 int wfd; /* write fd */ 76 int efd; /* extended fd */ 77 int sock; /* sock fd */ 78 int ctl_fd; /* control fd (client sharing) */ 79 int isatty; /* rfd is a tty */ 80 int wfd_isatty; /* wfd is a tty */ 81 int client_tty; /* (client) TTY has been requested */ 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 void *confirm_ctx; 109 channel_callback_fn *detach_user; 110 int detach_close; 111 112 /* filter */ 113 channel_infilter_fn *input_filter; 114 channel_outfilter_fn *output_filter; 115 116 int datagram; /* keep boundaries */ 117}; 118 119#define CHAN_EXTENDED_IGNORE 0 120#define CHAN_EXTENDED_READ 1 121#define CHAN_EXTENDED_WRITE 2 122 123/* default window/packet sizes for tcp/x11-fwd-channel */ 124#define CHAN_SES_PACKET_DEFAULT (32*1024) 125#define CHAN_SES_WINDOW_DEFAULT (4*CHAN_SES_PACKET_DEFAULT) 126#define CHAN_TCP_PACKET_DEFAULT (32*1024) 127#define CHAN_TCP_WINDOW_DEFAULT (4*CHAN_TCP_PACKET_DEFAULT) 128#define CHAN_X11_PACKET_DEFAULT (16*1024) 129#define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT) 130 131/* possible input states */ 132#define CHAN_INPUT_OPEN 0 133#define CHAN_INPUT_WAIT_DRAIN 1 134#define CHAN_INPUT_WAIT_OCLOSE 2 135#define CHAN_INPUT_CLOSED 3 136 137/* possible output states */ 138#define CHAN_OUTPUT_OPEN 0 139#define CHAN_OUTPUT_WAIT_DRAIN 1 140#define CHAN_OUTPUT_WAIT_IEOF 2 141#define CHAN_OUTPUT_CLOSED 3 142 143#define CHAN_CLOSE_SENT 0x01 144#define CHAN_CLOSE_RCVD 0x02 145#define CHAN_EOF_SENT 0x04 146#define CHAN_EOF_RCVD 0x08 147 148#define CHAN_RBUF 16*1024 149 150/* check whether 'efd' is still in use */ 151#define CHANNEL_EFD_INPUT_ACTIVE(c) \ 152 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \ 153 (c->efd != -1 || \ 154 buffer_len(&c->extended) > 0)) 155#define CHANNEL_EFD_OUTPUT_ACTIVE(c) \ 156 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \ 157 c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \ 158 buffer_len(&c->extended) > 0)) 159 160/* channel management */ 161 162Channel *channel_by_id(int); 163Channel *channel_lookup(int); 164Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int); 165void channel_set_fds(int, int, int, int, int, int, u_int); 166void channel_free(Channel *); 167void channel_free_all(void); 168void channel_stop_listening(void); 169 170void channel_send_open(int); 171void channel_request_start(int, char *, int); 172void channel_register_cleanup(int, channel_callback_fn *, int); 173void channel_register_confirm(int, channel_callback_fn *, void *); 174void channel_register_filter(int, channel_infilter_fn *, channel_outfilter_fn *); 175void channel_cancel_cleanup(int); 176int channel_close_fd(int *); 177void channel_send_window_changes(void); 178 179/* protocol handler */ 180 181void channel_input_close(int, u_int32_t, void *); 182void channel_input_close_confirmation(int, u_int32_t, void *); 183void channel_input_data(int, u_int32_t, void *); 184void channel_input_extended_data(int, u_int32_t, void *); 185void channel_input_ieof(int, u_int32_t, void *); 186void channel_input_oclose(int, u_int32_t, void *); 187void channel_input_open_confirmation(int, u_int32_t, void *); 188void channel_input_open_failure(int, u_int32_t, void *); 189void channel_input_port_open(int, u_int32_t, void *); 190void channel_input_window_adjust(int, u_int32_t, void *); 191 192/* file descriptor handling (read/write) */ 193 194void channel_prepare_select(fd_set **, fd_set **, int *, u_int*, int); 195void channel_after_select(fd_set *, fd_set *); 196void channel_output_poll(void); 197 198int channel_not_very_much_buffered_data(void); 199void channel_close_all(void); 200int channel_still_open(void); 201char *channel_open_message(void); 202int channel_find_open(void); 203 204/* tcp forwarding */ 205void channel_set_af(int af); 206void channel_permit_all_opens(void); 207void channel_add_permitted_opens(char *, int); 208int channel_add_adm_permitted_opens(char *, int); 209void channel_clear_permitted_opens(void); 210void channel_clear_adm_permitted_opens(void); 211int channel_input_port_forward_request(int, int); 212int channel_connect_to(const char *, u_short); 213int channel_connect_by_listen_address(u_short); 214int channel_request_remote_forwarding(const char *, u_short, 215 const char *, u_short); 216int channel_setup_local_fwd_listener(const char *, u_short, 217 const char *, u_short, int); 218void channel_request_rforward_cancel(const char *host, u_short port); 219int channel_setup_remote_fwd_listener(const char *, u_short, int); 220int channel_cancel_rport_listener(const char *, u_short); 221 222/* x11 forwarding */ 223 224int x11_connect_display(void); 225int x11_create_display_inet(int, int, int, u_int *, int **); 226void x11_input_open(int, u_int32_t, void *); 227void x11_request_forwarding_with_spoofing(int, const char *, const char *, 228 const char *); 229void deny_input_open(int, u_int32_t, void *); 230 231/* agent forwarding */ 232 233void auth_request_forwarding(void); 234 235/* channel close */ 236 237int chan_is_dead(Channel *, int); 238void chan_mark_dead(Channel *); 239 240/* channel events */ 241 242void chan_rcvd_oclose(Channel *); 243void chan_read_failed(Channel *); 244void chan_ibuf_empty(Channel *); 245 246void chan_rcvd_ieof(Channel *); 247void chan_write_failed(Channel *); 248void chan_obuf_empty(Channel *); 249 250#endif 251