channels.h revision 61199
1/* RCSID("$Id: channels.h,v 1.13 2000/05/30 17:23:37 markus Exp $"); */ 2 3#ifndef CHANNELS_H 4#define CHANNELS_H 5 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 19 20/* 21 * Data structure for channel data. This is iniailized in channel_allocate 22 * and cleared in channel_free. 23 */ 24typedef void channel_callback_fn(int id, void *arg); 25 26typedef struct Channel { 27 int type; /* channel type/state */ 28 int self; /* my own channel identifier */ 29 int remote_id; /* channel identifier for remote peer */ 30 /* peer can be reached over encrypted connection, via packet-sent */ 31 int istate; /* input from channel (state of receive half) */ 32 int ostate; /* output to channel (state of transmit half) */ 33 int flags; /* close sent/rcvd */ 34 int rfd; /* read fd */ 35 int wfd; /* write fd */ 36 int efd; /* extended fd */ 37 int sock; /* sock fd */ 38 Buffer input; /* data read from socket, to be sent over 39 * encrypted connection */ 40 Buffer output; /* data received over encrypted connection for 41 * send on socket */ 42 Buffer extended; 43 char path[200]; /* path for unix domain sockets, or host name 44 * for forwards */ 45 int listening_port; /* port being listened for forwards */ 46 int host_port; /* remote port to connect for forwards */ 47 char *remote_name; /* remote hostname */ 48 49 int remote_window; 50 int remote_maxpacket; 51 int local_window; 52 int local_window_max; 53 int local_consumed; 54 int local_maxpacket; 55 int extended_usage; 56 57 char *ctype; /* type */ 58 59 /* callback */ 60 channel_callback_fn *cb_fn; 61 void *cb_arg; 62 int cb_event; 63 channel_callback_fn *dettach_user; 64} Channel; 65 66#define CHAN_EXTENDED_IGNORE 0 67#define CHAN_EXTENDED_READ 1 68#define CHAN_EXTENDED_WRITE 2 69 70void channel_set_fds(int id, int rfd, int wfd, int efd, int extusage); 71void channel_open(int id); 72void channel_request(int id, char *service, int wantconfirm); 73void channel_request_start(int id, char *service, int wantconfirm); 74void channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg); 75void channel_register_cleanup(int id, channel_callback_fn *fn); 76void channel_cancel_cleanup(int id); 77Channel *channel_lookup(int id); 78 79int 80channel_new(char *ctype, int type, int rfd, int wfd, int efd, 81 int window, int maxpack, int extended_usage, char *remote_name); 82 83void channel_input_channel_request(int type, int plen); 84void channel_input_close(int type, int plen); 85void channel_input_close_confirmation(int type, int plen); 86void channel_input_data(int type, int plen); 87void channel_input_extended_data(int type, int plen); 88void channel_input_ieof(int type, int plen); 89void channel_input_oclose(int type, int plen); 90void channel_input_open_confirmation(int type, int plen); 91void channel_input_open_failure(int type, int plen); 92void channel_input_port_open(int type, int plen); 93void channel_input_window_adjust(int type, int plen); 94void channel_input_open(int type, int plen); 95 96/* Sets specific protocol options. */ 97void channel_set_options(int hostname_in_open); 98 99/* 100 * Allocate a new channel object and set its type and socket. Remote_name 101 * must have been allocated with xmalloc; this will free it when the channel 102 * is freed. 103 */ 104int channel_allocate(int type, int sock, char *remote_name); 105 106/* Free the channel and close its socket. */ 107void channel_free(int channel); 108 109/* Add any bits relevant to channels in select bitmasks. */ 110void channel_prepare_select(fd_set * readset, fd_set * writeset); 111 112/* 113 * After select, perform any appropriate operations for channels which have 114 * events pending. 115 */ 116void channel_after_select(fd_set * readset, fd_set * writeset); 117 118/* If there is data to send to the connection, send some of it now. */ 119void channel_output_poll(void); 120 121/* Returns true if no channel has too much buffered data. */ 122int channel_not_very_much_buffered_data(void); 123 124/* This closes any sockets that are listening for connections; this removes 125 any unix domain sockets. */ 126void channel_stop_listening(void); 127 128/* 129 * Closes the sockets of all channels. This is used to close extra file 130 * descriptors after a fork. 131 */ 132void channel_close_all(void); 133 134/* Returns the maximum file descriptor number used by the channels. */ 135int channel_max_fd(void); 136 137/* Returns true if there is still an open channel over the connection. */ 138int channel_still_open(void); 139 140/* 141 * Returns a string containing a list of all open channels. The list is 142 * suitable for displaying to the user. It uses crlf instead of newlines. 143 * The caller should free the string with xfree. 144 */ 145char *channel_open_message(void); 146 147/* 148 * Initiate forwarding of connections to local port "port" through the secure 149 * channel to host:port from remote side. This never returns if there was an 150 * error. 151 */ 152void 153channel_request_local_forwarding(u_short port, const char *host, 154 u_short remote_port, int gateway_ports); 155 156/* 157 * Initiate forwarding of connections to port "port" on remote host through 158 * the secure channel to host:port from local side. This never returns if 159 * there was an error. This registers that open requests for that port are 160 * permitted. 161 */ 162void 163channel_request_remote_forwarding(u_short port, const char *host, 164 u_short remote_port); 165 166/* 167 * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually 168 * called by the server, because the user could connect to any port anyway, 169 * and the server has no way to know but to trust the client anyway. 170 */ 171void channel_permit_all_opens(void); 172 173/* 174 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates 175 * listening for the port, and sends back a success reply (or disconnect 176 * message if there was an error). This never returns if there was an error. 177 */ 178void channel_input_port_forward_request(int is_root, int gateway_ports); 179 180/* 181 * Creates a port for X11 connections, and starts listening for it. Returns 182 * the display name, or NULL if an error was encountered. 183 */ 184char *x11_create_display(int screen); 185 186/* 187 * Creates an internet domain socket for listening for X11 connections. 188 * Returns a suitable value for the DISPLAY variable, or NULL if an error 189 * occurs. 190 */ 191char *x11_create_display_inet(int screen, int x11_display_offset); 192 193/* 194 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains 195 * the remote channel number. We should do whatever we want, and respond 196 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. 197 */ 198void x11_input_open(int type, int plen); 199 200/* 201 * Requests forwarding of X11 connections. This should be called on the 202 * client only. 203 */ 204void x11_request_forwarding(void); 205 206/* 207 * Requests forwarding for X11 connections, with authentication spoofing. 208 * This should be called in the client only. 209 */ 210void 211x11_request_forwarding_with_spoofing(int client_session_id, 212 const char *proto, const char *data); 213 214/* Sends a message to the server to request authentication fd forwarding. */ 215void auth_request_forwarding(void); 216 217/* 218 * Returns the name of the forwarded authentication socket. Returns NULL if 219 * there is no forwarded authentication socket. The returned value points to 220 * a static buffer. 221 */ 222char *auth_get_socket_name(void); 223 224/* 225 * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. 226 * This starts forwarding authentication requests. 227 */ 228int auth_input_request_forwarding(struct passwd * pw); 229 230/* This is called to process an SSH_SMSG_AGENT_OPEN message. */ 231void auth_input_open_request(int type, int plen); 232 233/* XXX */ 234int channel_connect_to(const char *host, u_short host_port); 235int x11_connect_display(void); 236 237#endif 238