Annotation of src/usr.bin/ssh/channels.h, Revision 1.33
1.17 deraadt 1: /*
1.19 markus 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: /*
1.17 deraadt 13: * Copyright (c) 2000 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: */
1.33 ! markus 35: /* RCSID("$OpenBSD: channels.h,v 1.32 2001/05/04 23:47:33 markus Exp $"); */
1.2 markus 36:
1.1 markus 37: #ifndef CHANNELS_H
38: #define CHANNELS_H
39:
1.28 markus 40: #include "buffer.h"
41:
1.1 markus 42: /* Definitions for channel types. */
1.6 markus 43: #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
1.5 deraadt 44: #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
45: #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
46: #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
1.6 markus 47: #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
1.7 markus 48: #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
49: #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
50: #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
51: #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
52: #define SSH_CHANNEL_LARVAL 10 /* larval session */
1.23 markus 53: #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */
1.24 markus 54: #define SSH_CHANNEL_CONNECTING 12
1.30 markus 55: #define SSH_CHANNEL_DYNAMIC 13
1.33 ! markus 56: #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */
! 57: #define SSH_CHANNEL_MAX_TYPE 15
1.1 markus 58:
1.32 markus 59: #define SSH_CHANNEL_PATH_LEN 30
60:
1.6 markus 61: /*
1.32 markus 62: * Data structure for channel data. This is initialized in channel_new
1.6 markus 63: * and cleared in channel_free.
64: */
1.16 markus 65: struct Channel;
66: typedef struct Channel Channel;
67:
1.7 markus 68: typedef void channel_callback_fn(int id, void *arg);
1.16 markus 69: typedef int channel_filter_fn(struct Channel *c, char *buf, int len);
1.1 markus 70:
1.16 markus 71: struct Channel {
1.5 deraadt 72: int type; /* channel type/state */
73: int self; /* my own channel identifier */
74: int remote_id; /* channel identifier for remote peer */
75: /* peer can be reached over encrypted connection, via packet-sent */
76: int istate; /* input from channel (state of receive half) */
77: int ostate; /* output to channel (state of transmit half) */
1.8 markus 78: int flags; /* close sent/rcvd */
1.7 markus 79: int rfd; /* read fd */
80: int wfd; /* write fd */
81: int efd; /* extended fd */
82: int sock; /* sock fd */
1.27 markus 83: int isatty; /* rfd is a tty */
1.5 deraadt 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 */
1.7 markus 88: Buffer extended;
1.32 markus 89: char path[SSH_CHANNEL_PATH_LEN];
90: /* path for unix domain sockets, or host name for forwards */
1.5 deraadt 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 */
1.7 markus 94:
95: int remote_window;
96: int remote_maxpacket;
97: int local_window;
98: int local_window_max;
99: int local_consumed;
100: int local_maxpacket;
101: int extended_usage;
102:
103: char *ctype; /* type */
104:
1.11 markus 105: /* callback */
1.7 markus 106: channel_callback_fn *cb_fn;
107: void *cb_arg;
108: int cb_event;
109: channel_callback_fn *dettach_user;
1.15 markus 110:
111: /* filter */
112: channel_filter_fn *input_filter;
1.16 markus 113: };
1.7 markus 114:
115: #define CHAN_EXTENDED_IGNORE 0
116: #define CHAN_EXTENDED_READ 1
117: #define CHAN_EXTENDED_WRITE 2
1.18 markus 118:
119: /* default window/packet sizes for tcp/x11-fwd-channel */
120: #define CHAN_SES_WINDOW_DEFAULT (32*1024)
121: #define CHAN_SES_PACKET_DEFAULT (CHAN_SES_WINDOW_DEFAULT/2)
122: #define CHAN_TCP_WINDOW_DEFAULT (32*1024)
123: #define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2)
124: #define CHAN_X11_WINDOW_DEFAULT (4*1024)
125: #define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2)
126:
1.7 markus 127:
128: void channel_open(int id);
1.8 markus 129: void channel_request(int id, char *service, int wantconfirm);
130: void channel_request_start(int id, char *service, int wantconfirm);
131: void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
132: void channel_register_cleanup(int id, channel_callback_fn *fn);
1.15 markus 133: void channel_register_filter(int id, channel_filter_fn *fn);
1.8 markus 134: void channel_cancel_cleanup(int id);
1.7 markus 135: Channel *channel_lookup(int id);
136:
1.21 markus 137: void
138: channel_set_fds(int id, int rfd, int wfd, int efd,
139: int extusage, int nonblock);
1.22 markus 140:
141: void deny_input_open(int type, int plen, void *ctxt);
1.7 markus 142:
1.20 markus 143: void channel_input_channel_request(int type, int plen, void *ctxt);
144: void channel_input_close(int type, int plen, void *ctxt);
145: void channel_input_close_confirmation(int type, int plen, void *ctxt);
146: void channel_input_data(int type, int plen, void *ctxt);
147: void channel_input_extended_data(int type, int plen, void *ctxt);
148: void channel_input_ieof(int type, int plen, void *ctxt);
149: void channel_input_oclose(int type, int plen, void *ctxt);
150: void channel_input_open_confirmation(int type, int plen, void *ctxt);
151: void channel_input_open_failure(int type, int plen, void *ctxt);
152: void channel_input_port_open(int type, int plen, void *ctxt);
153: void channel_input_window_adjust(int type, int plen, void *ctxt);
1.7 markus 154:
155: /* Sets specific protocol options. */
156: void channel_set_options(int hostname_in_open);
157:
158: /*
159: * Allocate a new channel object and set its type and socket. Remote_name
160: * must have been allocated with xmalloc; this will free it when the channel
161: * is freed.
162: */
1.32 markus 163: Channel *
164: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
165: int window, int maxpack, int extended_usage, char *remote_name,
166: int nonblock);
1.7 markus 167:
168: /* Free the channel and close its socket. */
1.32 markus 169: void channel_free(Channel *c);
1.7 markus 170:
1.25 markus 171: /*
172: * Allocate/update select bitmasks and add any bits relevant to channels in
173: * select bitmasks.
174: */
175: void
1.29 markus 176: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
177: int rekeying);
1.7 markus 178:
179: /*
180: * After select, perform any appropriate operations for channels which have
181: * events pending.
182: */
183: void channel_after_select(fd_set * readset, fd_set * writeset);
184:
185: /* If there is data to send to the connection, send some of it now. */
186: void channel_output_poll(void);
187:
188: /* Returns true if no channel has too much buffered data. */
189: int channel_not_very_much_buffered_data(void);
190:
191: /* This closes any sockets that are listening for connections; this removes
192: any unix domain sockets. */
193: void channel_stop_listening(void);
194:
195: /*
196: * Closes the sockets of all channels. This is used to close extra file
197: * descriptors after a fork.
198: */
199: void channel_close_all(void);
200:
201: /* Returns true if there is still an open channel over the connection. */
202: int channel_still_open(void);
203:
204: /*
205: * Returns a string containing a list of all open channels. The list is
206: * suitable for displaying to the user. It uses crlf instead of newlines.
207: * The caller should free the string with xfree.
208: */
209: char *channel_open_message(void);
210:
211: /*
212: * Initiate forwarding of connections to local port "port" through the secure
1.23 markus 213: * channel to host:port from remote side.
1.7 markus 214: */
1.26 markus 215: int
1.23 markus 216: channel_request_local_forwarding(u_short listen_port,
217: const char *host_to_connect, u_short port_to_connect, int gateway_ports);
1.26 markus 218: int
1.23 markus 219: channel_request_forwarding(const char *listen_address, u_short listen_port,
220: const char *host_to_connect, u_short port_to_connect, int gateway_ports,
221: int remote_fwd);
1.7 markus 222:
223: /*
224: * Initiate forwarding of connections to port "port" on remote host through
225: * the secure channel to host:port from local side. This never returns if
226: * there was an error. This registers that open requests for that port are
227: * permitted.
228: */
1.9 markus 229: void
1.7 markus 230: channel_request_remote_forwarding(u_short port, const char *host,
231: u_short remote_port);
232:
233: /*
1.28 markus 234: * Permits opening to any host/port if permitted_opens[] is empty. This is
235: * usually called by the server, because the user could connect to any port
236: * anyway, and the server has no way to know but to trust the client anyway.
1.7 markus 237: */
238: void channel_permit_all_opens(void);
1.28 markus 239:
240: /* Add host/port to list of allowed targets for port forwarding */
241: void channel_add_permitted_opens(char *host, int port);
242:
243: /* Flush list */
244: void channel_clear_permitted_opens(void);
1.7 markus 245:
246: /*
247: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
248: * listening for the port, and sends back a success reply (or disconnect
249: * message if there was an error). This never returns if there was an error.
250: */
1.12 markus 251: void channel_input_port_forward_request(int is_root, int gateway_ports);
1.7 markus 252:
253: /*
254: * Creates a port for X11 connections, and starts listening for it. Returns
255: * the display name, or NULL if an error was encountered.
256: */
257: char *x11_create_display(int screen);
258:
259: /*
260: * Creates an internet domain socket for listening for X11 connections.
261: * Returns a suitable value for the DISPLAY variable, or NULL if an error
262: * occurs.
263: */
264: char *x11_create_display_inet(int screen, int x11_display_offset);
265:
266: /*
267: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
268: * the remote channel number. We should do whatever we want, and respond
269: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
270: */
1.20 markus 271: void x11_input_open(int type, int plen, void *ctxt);
1.7 markus 272:
273: /*
274: * Requests forwarding of X11 connections. This should be called on the
275: * client only.
276: */
277: void x11_request_forwarding(void);
278:
279: /*
280: * Requests forwarding for X11 connections, with authentication spoofing.
281: * This should be called in the client only.
282: */
1.10 markus 283: void
284: x11_request_forwarding_with_spoofing(int client_session_id,
285: const char *proto, const char *data);
1.7 markus 286:
287: /* Sends a message to the server to request authentication fd forwarding. */
288: void auth_request_forwarding(void);
289:
290: /*
291: * Returns the name of the forwarded authentication socket. Returns NULL if
292: * there is no forwarded authentication socket. The returned value points to
293: * a static buffer.
294: */
295: char *auth_get_socket_name(void);
296:
297: /*
1.13 markus 298: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.7 markus 299: * This starts forwarding authentication requests.
300: */
1.13 markus 301: int auth_input_request_forwarding(struct passwd * pw);
1.7 markus 302:
303: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
1.20 markus 304: void auth_input_open_request(int type, int plen, void *ctxt);
1.8 markus 305:
306: /* XXX */
307: int channel_connect_to(const char *host, u_short host_port);
1.23 markus 308: int channel_connect_by_listen_adress(u_short listen_port);
1.10 markus 309: int x11_connect_display(void);
1.31 beck 310:
311: int channel_find_open(void);
1.7 markus 312:
1.1 markus 313: #endif
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