Annotation of src/usr.bin/ssh/channels.h, Revision 1.18
1.17 deraadt 1: /*
2: * Copyright (c) 2000 Markus Friedl. All rights reserved.
3: *
4: * Redistribution and use in source and binary forms, with or without
5: * modification, are permitted provided that the following conditions
6: * are met:
7: * 1. Redistributions of source code must retain the above copyright
8: * notice, this list of conditions and the following disclaimer.
9: * 2. Redistributions in binary form must reproduce the above copyright
10: * notice, this list of conditions and the following disclaimer in the
11: * documentation and/or other materials provided with the distribution.
12: *
13: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: */
1.18 ! markus 24: /* RCSID("$OpenBSD: channels.h,v 1.17 2000/09/07 20:27:50 deraadt Exp $"); */
1.2 markus 25:
1.1 markus 26: #ifndef CHANNELS_H
27: #define CHANNELS_H
28:
29: /* Definitions for channel types. */
1.6 markus 30: #define SSH_CHANNEL_FREE 0 /* This channel is free (unused). */
31: #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
1.5 deraadt 32: #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
33: #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
34: #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
1.6 markus 35: #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
1.7 markus 36: #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
37: #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
38: #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
39: #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
40: #define SSH_CHANNEL_LARVAL 10 /* larval session */
41: #define SSH_CHANNEL_MAX_TYPE 11
1.1 markus 42:
1.6 markus 43: /*
44: * Data structure for channel data. This is iniailized in channel_allocate
45: * and cleared in channel_free.
46: */
1.16 markus 47: struct Channel;
48: typedef struct Channel Channel;
49:
1.7 markus 50: typedef void channel_callback_fn(int id, void *arg);
1.16 markus 51: typedef int channel_filter_fn(struct Channel *c, char *buf, int len);
1.1 markus 52:
1.16 markus 53: struct Channel {
1.5 deraadt 54: int type; /* channel type/state */
55: int self; /* my own channel identifier */
56: int remote_id; /* channel identifier for remote peer */
57: /* peer can be reached over encrypted connection, via packet-sent */
58: int istate; /* input from channel (state of receive half) */
59: int ostate; /* output to channel (state of transmit half) */
1.8 markus 60: int flags; /* close sent/rcvd */
1.7 markus 61: int rfd; /* read fd */
62: int wfd; /* write fd */
63: int efd; /* extended fd */
64: int sock; /* sock fd */
1.5 deraadt 65: Buffer input; /* data read from socket, to be sent over
66: * encrypted connection */
67: Buffer output; /* data received over encrypted connection for
68: * send on socket */
1.7 markus 69: Buffer extended;
1.5 deraadt 70: char path[200]; /* path for unix domain sockets, or host name
71: * for forwards */
72: int listening_port; /* port being listened for forwards */
73: int host_port; /* remote port to connect for forwards */
74: char *remote_name; /* remote hostname */
1.7 markus 75:
76: int remote_window;
77: int remote_maxpacket;
78: int local_window;
79: int local_window_max;
80: int local_consumed;
81: int local_maxpacket;
82: int extended_usage;
83:
84: char *ctype; /* type */
85:
1.11 markus 86: /* callback */
1.7 markus 87: channel_callback_fn *cb_fn;
88: void *cb_arg;
89: int cb_event;
90: channel_callback_fn *dettach_user;
1.15 markus 91:
92: /* filter */
93: channel_filter_fn *input_filter;
1.16 markus 94: };
1.7 markus 95:
96: #define CHAN_EXTENDED_IGNORE 0
97: #define CHAN_EXTENDED_READ 1
98: #define CHAN_EXTENDED_WRITE 2
1.18 ! markus 99:
! 100: /* default window/packet sizes for tcp/x11-fwd-channel */
! 101: #define CHAN_SES_WINDOW_DEFAULT (32*1024)
! 102: #define CHAN_SES_PACKET_DEFAULT (CHAN_SES_WINDOW_DEFAULT/2)
! 103: #define CHAN_TCP_WINDOW_DEFAULT (32*1024)
! 104: #define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2)
! 105: #define CHAN_X11_WINDOW_DEFAULT (4*1024)
! 106: #define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2)
! 107:
1.7 markus 108:
1.8 markus 109: void channel_set_fds(int id, int rfd, int wfd, int efd, int extusage);
1.7 markus 110: void channel_open(int id);
1.8 markus 111: void channel_request(int id, char *service, int wantconfirm);
112: void channel_request_start(int id, char *service, int wantconfirm);
113: void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
114: void channel_register_cleanup(int id, channel_callback_fn *fn);
1.15 markus 115: void channel_register_filter(int id, channel_filter_fn *fn);
1.8 markus 116: void channel_cancel_cleanup(int id);
1.7 markus 117: Channel *channel_lookup(int id);
118:
119: int
120: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
121: int window, int maxpack, int extended_usage, char *remote_name);
122:
1.8 markus 123: void channel_input_channel_request(int type, int plen);
1.7 markus 124: void channel_input_close(int type, int plen);
125: void channel_input_close_confirmation(int type, int plen);
126: void channel_input_data(int type, int plen);
1.8 markus 127: void channel_input_extended_data(int type, int plen);
1.7 markus 128: void channel_input_ieof(int type, int plen);
129: void channel_input_oclose(int type, int plen);
130: void channel_input_open_confirmation(int type, int plen);
131: void channel_input_open_failure(int type, int plen);
132: void channel_input_port_open(int type, int plen);
1.8 markus 133: void channel_input_window_adjust(int type, int plen);
1.7 markus 134: void channel_input_open(int type, int plen);
135:
136: /* Sets specific protocol options. */
137: void channel_set_options(int hostname_in_open);
138:
139: /*
140: * Allocate a new channel object and set its type and socket. Remote_name
141: * must have been allocated with xmalloc; this will free it when the channel
142: * is freed.
143: */
144: int channel_allocate(int type, int sock, char *remote_name);
145:
146: /* Free the channel and close its socket. */
147: void channel_free(int channel);
148:
149: /* Add any bits relevant to channels in select bitmasks. */
150: void channel_prepare_select(fd_set * readset, fd_set * writeset);
151:
152: /*
153: * After select, perform any appropriate operations for channels which have
154: * events pending.
155: */
156: void channel_after_select(fd_set * readset, fd_set * writeset);
157:
158: /* If there is data to send to the connection, send some of it now. */
159: void channel_output_poll(void);
160:
161: /* Returns true if no channel has too much buffered data. */
162: int channel_not_very_much_buffered_data(void);
163:
164: /* This closes any sockets that are listening for connections; this removes
165: any unix domain sockets. */
166: void channel_stop_listening(void);
167:
168: /*
169: * Closes the sockets of all channels. This is used to close extra file
170: * descriptors after a fork.
171: */
172: void channel_close_all(void);
173:
174: /* Returns the maximum file descriptor number used by the channels. */
175: int channel_max_fd(void);
176:
177: /* Returns true if there is still an open channel over the connection. */
178: int channel_still_open(void);
179:
180: /*
181: * Returns a string containing a list of all open channels. The list is
182: * suitable for displaying to the user. It uses crlf instead of newlines.
183: * The caller should free the string with xfree.
184: */
185: char *channel_open_message(void);
186:
187: /*
188: * Initiate forwarding of connections to local port "port" through the secure
189: * channel to host:port from remote side. This never returns if there was an
190: * error.
191: */
1.9 markus 192: void
1.7 markus 193: channel_request_local_forwarding(u_short port, const char *host,
194: u_short remote_port, int gateway_ports);
195:
196: /*
197: * Initiate forwarding of connections to port "port" on remote host through
198: * the secure channel to host:port from local side. This never returns if
199: * there was an error. This registers that open requests for that port are
200: * permitted.
201: */
1.9 markus 202: void
1.7 markus 203: channel_request_remote_forwarding(u_short port, const char *host,
204: u_short remote_port);
205:
206: /*
207: * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
208: * called by the server, because the user could connect to any port anyway,
209: * and the server has no way to know but to trust the client anyway.
210: */
211: void channel_permit_all_opens(void);
212:
213: /*
214: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
215: * listening for the port, and sends back a success reply (or disconnect
216: * message if there was an error). This never returns if there was an error.
217: */
1.12 markus 218: void channel_input_port_forward_request(int is_root, int gateway_ports);
1.7 markus 219:
220: /*
221: * Creates a port for X11 connections, and starts listening for it. Returns
222: * the display name, or NULL if an error was encountered.
223: */
224: char *x11_create_display(int screen);
225:
226: /*
227: * Creates an internet domain socket for listening for X11 connections.
228: * Returns a suitable value for the DISPLAY variable, or NULL if an error
229: * occurs.
230: */
231: char *x11_create_display_inet(int screen, int x11_display_offset);
232:
233: /*
234: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
235: * the remote channel number. We should do whatever we want, and respond
236: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
237: */
238: void x11_input_open(int type, int plen);
239:
240: /*
241: * Requests forwarding of X11 connections. This should be called on the
242: * client only.
243: */
244: void x11_request_forwarding(void);
245:
246: /*
247: * Requests forwarding for X11 connections, with authentication spoofing.
248: * This should be called in the client only.
249: */
1.10 markus 250: void
251: x11_request_forwarding_with_spoofing(int client_session_id,
252: const char *proto, const char *data);
1.7 markus 253:
254: /* Sends a message to the server to request authentication fd forwarding. */
255: void auth_request_forwarding(void);
256:
257: /*
258: * Returns the name of the forwarded authentication socket. Returns NULL if
259: * there is no forwarded authentication socket. The returned value points to
260: * a static buffer.
261: */
262: char *auth_get_socket_name(void);
263:
264: /*
1.13 markus 265: * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
1.7 markus 266: * This starts forwarding authentication requests.
267: */
1.13 markus 268: int auth_input_request_forwarding(struct passwd * pw);
1.7 markus 269:
270: /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
271: void auth_input_open_request(int type, int plen);
1.8 markus 272:
273: /* XXX */
274: int channel_connect_to(const char *host, u_short host_port);
1.10 markus 275: int x11_connect_display(void);
1.7 markus 276:
1.1 markus 277: #endif