Annotation of src/usr.bin/ssh/channels.h, Revision 1.22.2.3
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: */
1.22.2.3! jason 35: /* RCSID("$OpenBSD: channels.h,v 1.28 2001/03/16 19:06:29 markus Exp $"); */
1.2 markus 36:
1.1 markus 37: #ifndef CHANNELS_H
38: #define CHANNELS_H
39:
1.22.2.3! jason 40: #include "buffer.h"
! 41:
1.1 markus 42: /* Definitions for channel types. */
1.6 markus 43: #define SSH_CHANNEL_FREE 0 /* This channel is free (unused). */
44: #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
1.5 deraadt 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 */
1.6 markus 48: #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
1.7 markus 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 */
1.22.2.1 jason 54: #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */
55: #define SSH_CHANNEL_CONNECTING 12
56: #define SSH_CHANNEL_MAX_TYPE 13
1.1 markus 57:
1.6 markus 58: /*
59: * Data structure for channel data. This is iniailized in channel_allocate
60: * and cleared in channel_free.
61: */
1.16 markus 62: struct Channel;
63: typedef struct Channel Channel;
64:
1.7 markus 65: typedef void channel_callback_fn(int id, void *arg);
1.16 markus 66: typedef int channel_filter_fn(struct Channel *c, char *buf, int len);
1.1 markus 67:
1.16 markus 68: struct Channel {
1.5 deraadt 69: int type; /* channel type/state */
70: int self; /* my own channel identifier */
71: int remote_id; /* channel identifier for remote peer */
72: /* peer can be reached over encrypted connection, via packet-sent */
73: int istate; /* input from channel (state of receive half) */
74: int ostate; /* output to channel (state of transmit half) */
1.8 markus 75: int flags; /* close sent/rcvd */
1.7 markus 76: int rfd; /* read fd */
77: int wfd; /* write fd */
78: int efd; /* extended fd */
79: int sock; /* sock fd */
1.22.2.1 jason 80: int isatty; /* rfd is a tty */
1.5 deraadt 81: Buffer input; /* data read from socket, to be sent over
82: * encrypted connection */
83: Buffer output; /* data received over encrypted connection for
84: * send on socket */
1.7 markus 85: Buffer extended;
1.5 deraadt 86: char path[200]; /* path for unix domain sockets, or host name
87: * for forwards */
88: int listening_port; /* port being listened for forwards */
89: int host_port; /* remote port to connect for forwards */
90: char *remote_name; /* remote hostname */
1.7 markus 91:
92: int remote_window;
93: int remote_maxpacket;
94: int local_window;
95: int local_window_max;
96: int local_consumed;
97: int local_maxpacket;
98: int extended_usage;
99:
100: char *ctype; /* type */
101:
1.11 markus 102: /* callback */
1.7 markus 103: channel_callback_fn *cb_fn;
104: void *cb_arg;
105: int cb_event;
106: channel_callback_fn *dettach_user;
1.15 markus 107:
108: /* filter */
109: channel_filter_fn *input_filter;
1.16 markus 110: };
1.7 markus 111:
112: #define CHAN_EXTENDED_IGNORE 0
113: #define CHAN_EXTENDED_READ 1
114: #define CHAN_EXTENDED_WRITE 2
1.18 markus 115:
116: /* default window/packet sizes for tcp/x11-fwd-channel */
117: #define CHAN_SES_WINDOW_DEFAULT (32*1024)
118: #define CHAN_SES_PACKET_DEFAULT (CHAN_SES_WINDOW_DEFAULT/2)
119: #define CHAN_TCP_WINDOW_DEFAULT (32*1024)
120: #define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2)
121: #define CHAN_X11_WINDOW_DEFAULT (4*1024)
122: #define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2)
123:
1.7 markus 124:
125: void channel_open(int id);
1.8 markus 126: void channel_request(int id, char *service, int wantconfirm);
127: void channel_request_start(int id, char *service, int wantconfirm);
128: void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
129: void channel_register_cleanup(int id, channel_callback_fn *fn);
1.15 markus 130: void channel_register_filter(int id, channel_filter_fn *fn);
1.8 markus 131: void channel_cancel_cleanup(int id);
1.7 markus 132: Channel *channel_lookup(int id);
133:
134: int
135: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.21 markus 136: int window, int maxpack, int extended_usage, char *remote_name,
137: int nonblock);
138: void
139: channel_set_fds(int id, int rfd, int wfd, int efd,
140: int extusage, int nonblock);
1.22 markus 141:
142: void deny_input_open(int type, int plen, void *ctxt);
1.7 markus 143:
1.20 markus 144: void channel_input_channel_request(int type, int plen, void *ctxt);
145: void channel_input_close(int type, int plen, void *ctxt);
146: void channel_input_close_confirmation(int type, int plen, void *ctxt);
147: void channel_input_data(int type, int plen, void *ctxt);
148: void channel_input_extended_data(int type, int plen, void *ctxt);
149: void channel_input_ieof(int type, int plen, void *ctxt);
150: void channel_input_oclose(int type, int plen, void *ctxt);
151: void channel_input_open_confirmation(int type, int plen, void *ctxt);
152: void channel_input_open_failure(int type, int plen, void *ctxt);
153: void channel_input_port_open(int type, int plen, void *ctxt);
154: void channel_input_window_adjust(int type, int plen, void *ctxt);
1.7 markus 155:
156: /* Sets specific protocol options. */
157: void channel_set_options(int hostname_in_open);
158:
159: /*
160: * Allocate a new channel object and set its type and socket. Remote_name
161: * must have been allocated with xmalloc; this will free it when the channel
162: * is freed.
163: */
164: int channel_allocate(int type, int sock, char *remote_name);
165:
166: /* Free the channel and close its socket. */
167: void channel_free(int channel);
168:
1.22.2.1 jason 169: /*
170: * Allocate/update select bitmasks and add any bits relevant to channels in
171: * select bitmasks.
172: */
173: void
174: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp);
1.7 markus 175:
176: /*
177: * After select, perform any appropriate operations for channels which have
178: * events pending.
179: */
180: void channel_after_select(fd_set * readset, fd_set * writeset);
181:
182: /* If there is data to send to the connection, send some of it now. */
183: void channel_output_poll(void);
184:
185: /* Returns true if no channel has too much buffered data. */
186: int channel_not_very_much_buffered_data(void);
187:
188: /* This closes any sockets that are listening for connections; this removes
189: any unix domain sockets. */
190: void channel_stop_listening(void);
191:
192: /*
193: * Closes the sockets of all channels. This is used to close extra file
194: * descriptors after a fork.
195: */
196: void channel_close_all(void);
197:
198: /* Returns true if there is still an open channel over the connection. */
199: int channel_still_open(void);
200:
201: /*
202: * Returns a string containing a list of all open channels. The list is
203: * suitable for displaying to the user. It uses crlf instead of newlines.
204: * The caller should free the string with xfree.
205: */
206: char *channel_open_message(void);
207:
208: /*
209: * Initiate forwarding of connections to local port "port" through the secure
1.22.2.1 jason 210: * channel to host:port from remote side.
1.7 markus 211: */
1.22.2.1 jason 212: int
213: channel_request_local_forwarding(u_short listen_port,
214: const char *host_to_connect, u_short port_to_connect, int gateway_ports);
215: int
216: channel_request_forwarding(const char *listen_address, u_short listen_port,
217: const char *host_to_connect, u_short port_to_connect, int gateway_ports,
218: int remote_fwd);
1.7 markus 219:
220: /*
221: * Initiate forwarding of connections to port "port" on remote host through
222: * the secure channel to host:port from local side. This never returns if
223: * there was an error. This registers that open requests for that port are
224: * permitted.
225: */
1.9 markus 226: void
1.7 markus 227: channel_request_remote_forwarding(u_short port, const char *host,
228: u_short remote_port);
229:
230: /*
1.22.2.3! jason 231: * Permits opening to any host/port if permitted_opens[] is empty. This is
! 232: * usually called by the server, because the user could connect to any port
! 233: * anyway, and the server has no way to know but to trust the client anyway.
1.7 markus 234: */
235: void channel_permit_all_opens(void);
1.22.2.3! jason 236:
! 237: /* Add host/port to list of allowed targets for port forwarding */
! 238: void channel_add_permitted_opens(char *host, int port);
! 239:
! 240: /* Flush list */
! 241: void channel_clear_permitted_opens(void);
1.7 markus 242:
243: /*
244: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
245: * listening for the port, and sends back a success reply (or disconnect
246: * message if there was an error). This never returns if there was an error.
247: */
1.12 markus 248: void channel_input_port_forward_request(int is_root, int gateway_ports);
1.7 markus 249:
250: /*
251: * Creates a port for X11 connections, and starts listening for it. Returns
252: * the display name, or NULL if an error was encountered.
253: */
254: char *x11_create_display(int screen);
255:
256: /*
257: * Creates an internet domain socket for listening for X11 connections.
258: * Returns a suitable value for the DISPLAY variable, or NULL if an error
259: * occurs.
260: */
261: char *x11_create_display_inet(int screen, int x11_display_offset);
262:
263: /*
264: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
265: * the remote channel number. We should do whatever we want, and respond
266: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
267: */
1.20 markus 268: void x11_input_open(int type, int plen, void *ctxt);
1.7 markus 269:
270: /*
271: * Requests forwarding of X11 connections. This should be called on the
272: * client only.
273: */
274: void x11_request_forwarding(void);
275:
276: /*
277: * Requests forwarding for X11 connections, with authentication spoofing.
278: * This should be called in the client only.
279: */
1.10 markus 280: void
281: x11_request_forwarding_with_spoofing(int client_session_id,
282: const char *proto, const char *data);
1.7 markus 283:
284: /* Sends a message to the server to request authentication fd forwarding. */
285: void auth_request_forwarding(void);
286:
287: /*
288: * Returns the name of the forwarded authentication socket. Returns NULL if
289: * there is no forwarded authentication socket. The returned value points to
290: * a static buffer.
291: */
292: char *auth_get_socket_name(void);
293:
294: /*
1.13 markus 295: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.7 markus 296: * This starts forwarding authentication requests.
297: */
1.13 markus 298: int auth_input_request_forwarding(struct passwd * pw);
1.7 markus 299:
300: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
1.20 markus 301: void auth_input_open_request(int type, int plen, void *ctxt);
1.8 markus 302:
303: /* XXX */
304: int channel_connect_to(const char *host, u_short host_port);
1.22.2.1 jason 305: int channel_connect_by_listen_adress(u_short listen_port);
1.10 markus 306: int x11_connect_display(void);
1.7 markus 307:
1.1 markus 308: #endif
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