1 /* RCSID("$OpenBSD: channels.h,v 1.16 2000/08/19 21:55:51 markus Exp $"); */
6 /* Definitions for channel types. */
7 #define SSH_CHANNEL_FREE 0 /* This channel is free (unused). */
8 #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
9 #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
10 #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
11 #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
12 #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
13 #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
14 #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
15 #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
16 #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
17 #define SSH_CHANNEL_LARVAL 10 /* larval session */
18 #define SSH_CHANNEL_MAX_TYPE 11
21 * Data structure for channel data. This is iniailized in channel_allocate
22 * and cleared in channel_free.
25 typedef struct Channel Channel;
27 typedef void channel_callback_fn(int id, void *arg);
28 typedef int channel_filter_fn(struct Channel *c, char *buf, int len);
31 int type; /* channel type/state */
32 int self; /* my own channel identifier */
33 int remote_id; /* channel identifier for remote peer */
34 /* peer can be reached over encrypted connection, via packet-sent */
35 int istate; /* input from channel (state of receive half) */
36 int ostate; /* output to channel (state of transmit half) */
37 int flags; /* close sent/rcvd */
38 int rfd; /* read fd */
39 int wfd; /* write fd */
40 int efd; /* extended fd */
41 int sock; /* sock fd */
42 Buffer input; /* data read from socket, to be sent over
43 * encrypted connection */
44 Buffer output; /* data received over encrypted connection for
47 char path[200]; /* path for unix domain sockets, or host name
49 int listening_port; /* port being listened for forwards */
50 int host_port; /* remote port to connect for forwards */
51 char *remote_name; /* remote hostname */
61 char *ctype; /* type */
64 channel_callback_fn *cb_fn;
67 channel_callback_fn *dettach_user;
70 channel_filter_fn *input_filter;
73 #define CHAN_EXTENDED_IGNORE 0
74 #define CHAN_EXTENDED_READ 1
75 #define CHAN_EXTENDED_WRITE 2
77 void channel_set_fds(int id, int rfd, int wfd, int efd, int extusage);
78 void channel_open(int id);
79 void channel_request(int id, char *service, int wantconfirm);
80 void channel_request_start(int id, char *service, int wantconfirm);
81 void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
82 void channel_register_cleanup(int id, channel_callback_fn *fn);
83 void channel_register_filter(int id, channel_filter_fn *fn);
84 void channel_cancel_cleanup(int id);
85 Channel *channel_lookup(int id);
88 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
89 int window, int maxpack, int extended_usage, char *remote_name);
91 void channel_input_channel_request(int type, int plen);
92 void channel_input_close(int type, int plen);
93 void channel_input_close_confirmation(int type, int plen);
94 void channel_input_data(int type, int plen);
95 void channel_input_extended_data(int type, int plen);
96 void channel_input_ieof(int type, int plen);
97 void channel_input_oclose(int type, int plen);
98 void channel_input_open_confirmation(int type, int plen);
99 void channel_input_open_failure(int type, int plen);
100 void channel_input_port_open(int type, int plen);
101 void channel_input_window_adjust(int type, int plen);
102 void channel_input_open(int type, int plen);
104 /* Sets specific protocol options. */
105 void channel_set_options(int hostname_in_open);
108 * Allocate a new channel object and set its type and socket. Remote_name
109 * must have been allocated with xmalloc; this will free it when the channel
112 int channel_allocate(int type, int sock, char *remote_name);
114 /* Free the channel and close its socket. */
115 void channel_free(int channel);
117 /* Add any bits relevant to channels in select bitmasks. */
118 void channel_prepare_select(fd_set * readset, fd_set * writeset);
121 * After select, perform any appropriate operations for channels which have
124 void channel_after_select(fd_set * readset, fd_set * writeset);
126 /* If there is data to send to the connection, send some of it now. */
127 void channel_output_poll(void);
129 /* Returns true if no channel has too much buffered data. */
130 int channel_not_very_much_buffered_data(void);
132 /* This closes any sockets that are listening for connections; this removes
133 any unix domain sockets. */
134 void channel_stop_listening(void);
137 * Closes the sockets of all channels. This is used to close extra file
138 * descriptors after a fork.
140 void channel_close_all(void);
142 /* Returns the maximum file descriptor number used by the channels. */
143 int channel_max_fd(void);
145 /* Returns true if there is still an open channel over the connection. */
146 int channel_still_open(void);
149 * Returns a string containing a list of all open channels. The list is
150 * suitable for displaying to the user. It uses crlf instead of newlines.
151 * The caller should free the string with xfree.
153 char *channel_open_message(void);
156 * Initiate forwarding of connections to local port "port" through the secure
157 * channel to host:port from remote side. This never returns if there was an
161 channel_request_local_forwarding(u_short port, const char *host,
162 u_short remote_port, int gateway_ports);
165 * Initiate forwarding of connections to port "port" on remote host through
166 * the secure channel to host:port from local side. This never returns if
167 * there was an error. This registers that open requests for that port are
171 channel_request_remote_forwarding(u_short port, const char *host,
172 u_short remote_port);
175 * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
176 * called by the server, because the user could connect to any port anyway,
177 * and the server has no way to know but to trust the client anyway.
179 void channel_permit_all_opens(void);
182 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
183 * listening for the port, and sends back a success reply (or disconnect
184 * message if there was an error). This never returns if there was an error.
186 void channel_input_port_forward_request(int is_root, int gateway_ports);
189 * Creates a port for X11 connections, and starts listening for it. Returns
190 * the display name, or NULL if an error was encountered.
192 char *x11_create_display(int screen);
195 * Creates an internet domain socket for listening for X11 connections.
196 * Returns a suitable value for the DISPLAY variable, or NULL if an error
199 char *x11_create_display_inet(int screen, int x11_display_offset);
202 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
203 * the remote channel number. We should do whatever we want, and respond
204 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
206 void x11_input_open(int type, int plen);
209 * Requests forwarding of X11 connections. This should be called on the
212 void x11_request_forwarding(void);
215 * Requests forwarding for X11 connections, with authentication spoofing.
216 * This should be called in the client only.
219 x11_request_forwarding_with_spoofing(int client_session_id,
220 const char *proto, const char *data);
222 /* Sends a message to the server to request authentication fd forwarding. */
223 void auth_request_forwarding(void);
226 * Returns the name of the forwarded authentication socket. Returns NULL if
227 * there is no forwarded authentication socket. The returned value points to
230 char *auth_get_socket_name(void);
233 * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
234 * This starts forwarding authentication requests.
236 int auth_input_request_forwarding(struct passwd * pw);
238 /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
239 void auth_input_open_request(int type, int plen);
242 int channel_connect_to(const char *host, u_short host_port);
243 int x11_connect_display(void);