Annotation of src/usr.bin/ssh/channels.h, Revision 1.141
1.141 ! djm 1: /* $OpenBSD: channels.h,v 1.140 2022/01/06 21:48:38 djm Exp $ */
1.65 stevesk 2:
1.17 deraadt 3: /*
1.19 markus 4: * Author: Tatu Ylonen <ylo@cs.hut.fi>
5: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6: * All rights reserved
7: *
8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: */
14: /*
1.59 markus 15: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.17 deraadt 16: *
17: * Redistribution and use in source and binary forms, with or without
18: * modification, are permitted provided that the following conditions
19: * are met:
20: * 1. Redistributions of source code must retain the above copyright
21: * notice, this list of conditions and the following disclaimer.
22: * 2. Redistributions in binary form must reproduce the above copyright
23: * notice, this list of conditions and the following disclaimer in the
24: * documentation and/or other materials provided with the distribution.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36: */
1.2 markus 37:
1.35 markus 38: #ifndef CHANNEL_H
39: #define CHANNEL_H
1.28 markus 40:
1.1 markus 41: /* Definitions for channel types. */
1.6 markus 42: #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
1.5 deraadt 43: #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
44: #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
45: #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
1.6 markus 46: #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
1.7 markus 47: #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
48: #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
49: #define SSH_CHANNEL_LARVAL 10 /* larval session */
1.23 markus 50: #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */
1.24 markus 51: #define SSH_CHANNEL_CONNECTING 12
1.30 markus 52: #define SSH_CHANNEL_DYNAMIC 13
1.33 markus 53: #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */
1.103 djm 54: #define SSH_CHANNEL_MUX_LISTENER 15 /* Listener for mux conn. */
1.134 djm 55: #define SSH_CHANNEL_MUX_CLIENT 16 /* Conn. to mux client */
1.113 dtucker 56: #define SSH_CHANNEL_ABANDONED 17 /* Abandoned session, eg mux */
1.115 millert 57: #define SSH_CHANNEL_UNIX_LISTENER 18 /* Listening on a domain socket. */
58: #define SSH_CHANNEL_RUNIX_LISTENER 19 /* Listening to a R-style domain socket. */
1.134 djm 59: #define SSH_CHANNEL_MUX_PROXY 20 /* proxy channel for mux-client */
1.130 markus 60: #define SSH_CHANNEL_RDYNAMIC_OPEN 21 /* reverse SOCKS, parsing request */
61: #define SSH_CHANNEL_RDYNAMIC_FINISH 22 /* reverse SOCKS, finishing connect */
62: #define SSH_CHANNEL_MAX_TYPE 23
1.1 markus 63:
1.107 markus 64: #define CHANNEL_CANCEL_PORT_STATIC -1
65:
1.138 djm 66: /* nonblocking flags for channel_new */
67: #define CHANNEL_NONBLOCK_LEAVE 0 /* don't modify non-blocking state */
68: #define CHANNEL_NONBLOCK_SET 1 /* set non-blocking state */
69: #define CHANNEL_NONBLOCK_STDIO 2 /* set non-blocking and restore on close */
70:
71: /* c->restore_block mask flags */
72: #define CHANNEL_RESTORE_RFD 0x01
73: #define CHANNEL_RESTORE_WFD 0x02
74: #define CHANNEL_RESTORE_EFD 0x04
75:
1.131 djm 76: /* TCP forwarding */
77: #define FORWARD_DENY 0
78: #define FORWARD_REMOTE (1)
79: #define FORWARD_LOCAL (1<<1)
80: #define FORWARD_ALLOW (FORWARD_REMOTE|FORWARD_LOCAL)
81:
82: #define FORWARD_ADM 0x100
83: #define FORWARD_USER 0x101
84:
1.126 markus 85: struct ssh;
1.16 markus 86: struct Channel;
87: typedef struct Channel Channel;
1.128 djm 88: struct fwd_perm_list;
1.16 markus 89:
1.128 djm 90: typedef void channel_open_fn(struct ssh *, int, int, void *);
91: typedef void channel_callback_fn(struct ssh *, int, void *);
92: typedef int channel_infilter_fn(struct ssh *, struct Channel *, char *, int);
93: typedef void channel_filter_cleanup_fn(struct ssh *, int, void *);
94: typedef u_char *channel_outfilter_fn(struct ssh *, struct Channel *,
95: u_char **, size_t *);
1.1 markus 96:
1.90 djm 97: /* Channel success/failure callbacks */
1.128 djm 98: typedef void channel_confirm_cb(struct ssh *, int, struct Channel *, void *);
99: typedef void channel_confirm_abandon_cb(struct ssh *, struct Channel *, void *);
1.90 djm 100: struct channel_confirm {
101: TAILQ_ENTRY(channel_confirm) entry;
102: channel_confirm_cb *cb;
103: channel_confirm_abandon_cb *abandon_cb;
104: void *ctx;
105: };
106: TAILQ_HEAD(channel_confirms, channel_confirm);
107:
1.91 djm 108: /* Context for non-blocking connects */
109: struct channel_connect {
110: char *host;
111: int port;
112: struct addrinfo *ai, *aitop;
113: };
114:
1.103 djm 115: /* Callbacks for mux channels back into client-specific code */
1.128 djm 116: typedef int mux_callback_fn(struct ssh *, struct Channel *);
1.103 djm 117:
1.133 djm 118: /*
119: * NB. channel IDs on the wire and in c->remote_id are uint32, but local
120: * channel IDs (e.g. c->self) only ever use the int32 subset of this range,
121: * because we use local channel ID -1 for housekeeping. Remote channels have
122: * a dedicated "have_remote_id" flag to indicate their validity.
123: */
124:
1.16 markus 125: struct Channel {
1.5 deraadt 126: int type; /* channel type/state */
1.133 djm 127:
1.5 deraadt 128: int self; /* my own channel identifier */
1.129 djm 129: uint32_t remote_id; /* channel identifier for remote peer */
130: int have_remote_id; /* non-zero if remote_id is valid */
131:
1.57 markus 132: u_int istate; /* input from channel (state of receive half) */
133: u_int ostate; /* output to channel (state of transmit half) */
1.8 markus 134: int flags; /* close sent/rcvd */
1.7 markus 135: int rfd; /* read fd */
136: int wfd; /* write fd */
137: int efd; /* extended fd */
138: int sock; /* sock fd */
1.139 djm 139: u_int io_want; /* bitmask of SSH_CHAN_IO_* */
140: u_int io_ready; /* bitmask of SSH_CHAN_IO_* */
1.140 djm 141: int pollfd_offset; /* base offset into pollfd array (or -1) */
1.103 djm 142: int ctl_chan; /* control channel (multiplexed connections) */
1.27 markus 143: int isatty; /* rfd is a tty */
1.75 djm 144: int client_tty; /* (client) TTY has been requested */
1.48 markus 145: int force_drain; /* force close on iEOF */
1.111 djm 146: time_t notbefore; /* Pause IO until deadline (time_t) */
1.140 djm 147: int delayed; /* post-IO handlers for newly created
1.100 markus 148: * channels are delayed until the first call
1.140 djm 149: * to a matching pre-IO handler.
150: * this way post-IO handlers are not
1.112 dtucker 151: * accidentally called if a FD gets reused */
1.138 djm 152: int restore_block; /* fd mask to restore blocking status */
1.128 djm 153: struct sshbuf *input; /* data read from socket, to be sent over
1.5 deraadt 154: * encrypted connection */
1.128 djm 155: struct sshbuf *output; /* data received over encrypted connection for
1.5 deraadt 156: * send on socket */
1.128 djm 157: struct sshbuf *extended;
158:
1.97 djm 159: char *path;
1.32 markus 160: /* path for unix domain sockets, or host name for forwards */
1.5 deraadt 161: int listening_port; /* port being listened for forwards */
1.106 djm 162: char *listening_addr; /* addr being listened for forwards */
1.5 deraadt 163: int host_port; /* remote port to connect for forwards */
164: char *remote_name; /* remote hostname */
1.7 markus 165:
1.70 markus 166: u_int remote_window;
167: u_int remote_maxpacket;
168: u_int local_window;
169: u_int local_window_max;
170: u_int local_consumed;
171: u_int local_maxpacket;
1.7 markus 172: int extended_usage;
1.54 markus 173: int single_connection;
1.7 markus 174:
175: char *ctype; /* type */
176:
1.11 markus 177: /* callback */
1.104 djm 178: channel_open_fn *open_confirm;
1.90 djm 179: void *open_confirm_ctx;
1.44 markus 180: channel_callback_fn *detach_user;
1.80 djm 181: int detach_close;
1.90 djm 182: struct channel_confirms status_confirms;
1.15 markus 183:
184: /* filter */
1.83 reyk 185: channel_infilter_fn *input_filter;
186: channel_outfilter_fn *output_filter;
1.94 djm 187: void *filter_ctx;
1.95 djm 188: channel_filter_cleanup_fn *filter_cleanup;
1.81 reyk 189:
1.91 djm 190: /* keep boundaries */
1.136 djm 191: int datagram;
1.91 djm 192:
193: /* non-blocking connect */
1.128 djm 194: /* XXX make this a pointer so the structure can be opaque */
1.91 djm 195: struct channel_connect connect_ctx;
1.103 djm 196:
197: /* multiplexing protocol hook, called for each packet received */
198: mux_callback_fn *mux_rcb;
199: void *mux_ctx;
1.104 djm 200: int mux_pause;
1.136 djm 201: int mux_downstream_id;
1.16 markus 202: };
1.7 markus 203:
204: #define CHAN_EXTENDED_IGNORE 0
205: #define CHAN_EXTENDED_READ 1
206: #define CHAN_EXTENDED_WRITE 2
1.18 markus 207:
208: /* default window/packet sizes for tcp/x11-fwd-channel */
1.64 markus 209: #define CHAN_SES_PACKET_DEFAULT (32*1024)
1.89 markus 210: #define CHAN_SES_WINDOW_DEFAULT (64*CHAN_SES_PACKET_DEFAULT)
1.64 markus 211: #define CHAN_TCP_PACKET_DEFAULT (32*1024)
1.89 markus 212: #define CHAN_TCP_WINDOW_DEFAULT (64*CHAN_TCP_PACKET_DEFAULT)
1.64 markus 213: #define CHAN_X11_PACKET_DEFAULT (16*1024)
214: #define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT)
1.18 markus 215:
1.35 markus 216: /* possible input states */
1.57 markus 217: #define CHAN_INPUT_OPEN 0
218: #define CHAN_INPUT_WAIT_DRAIN 1
219: #define CHAN_INPUT_WAIT_OCLOSE 2
220: #define CHAN_INPUT_CLOSED 3
1.35 markus 221:
222: /* possible output states */
1.57 markus 223: #define CHAN_OUTPUT_OPEN 0
224: #define CHAN_OUTPUT_WAIT_DRAIN 1
225: #define CHAN_OUTPUT_WAIT_IEOF 2
226: #define CHAN_OUTPUT_CLOSED 3
1.7 markus 227:
1.35 markus 228: #define CHAN_CLOSE_SENT 0x01
229: #define CHAN_CLOSE_RCVD 0x02
1.66 markus 230: #define CHAN_EOF_SENT 0x04
231: #define CHAN_EOF_RCVD 0x08
1.103 djm 232: #define CHAN_LOCAL 0x10
1.139 djm 233:
234: /* file descriptor events */
235: #define SSH_CHAN_IO_RFD 0x01
236: #define SSH_CHAN_IO_WFD 0x02
237: #define SSH_CHAN_IO_EFD_R 0x04
238: #define SSH_CHAN_IO_EFD_W 0x08
1.140 djm 239: #define SSH_CHAN_IO_EFD (SSH_CHAN_IO_EFD_R|SSH_CHAN_IO_EFD_W)
1.139 djm 240: #define SSH_CHAN_IO_SOCK_R 0x10
241: #define SSH_CHAN_IO_SOCK_W 0x20
1.140 djm 242: #define SSH_CHAN_IO_SOCK (SSH_CHAN_IO_SOCK_R|SSH_CHAN_IO_SOCK_W)
1.66 markus 243:
1.128 djm 244: /* Read buffer size */
245: #define CHAN_RBUF (16*1024)
1.141 ! djm 246:
! 247: /* Maximum size for direct reads to buffers */
! 248: #define CHANNEL_MAX_READ CHAN_SES_PACKET_DEFAULT
1.135 djm 249:
250: /* Maximum channel input buffer size */
251: #define CHAN_INPUT_MAX (16*1024*1024)
1.128 djm 252:
253: /* Hard limit on number of channels */
254: #define CHANNELS_MAX_CHANNELS (16*1024)
1.83 reyk 255:
1.66 markus 256: /* check whether 'efd' is still in use */
257: #define CHANNEL_EFD_INPUT_ACTIVE(c) \
1.122 djm 258: (c->extended_usage == CHAN_EXTENDED_READ && \
1.66 markus 259: (c->efd != -1 || \
1.128 djm 260: sshbuf_len(c->extended) > 0))
1.66 markus 261: #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
1.122 djm 262: (c->extended_usage == CHAN_EXTENDED_WRITE && \
1.78 markus 263: c->efd != -1 && (!(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD)) || \
1.128 djm 264: sshbuf_len(c->extended) > 0))
265:
266: /* Add channel management structures to SSH transport instance */
267: void channel_init_channels(struct ssh *ssh);
1.35 markus 268:
269: /* channel management */
270:
1.128 djm 271: Channel *channel_by_id(struct ssh *, int);
1.129 djm 272: Channel *channel_by_remote_id(struct ssh *, u_int);
1.128 djm 273: Channel *channel_lookup(struct ssh *, int);
274: Channel *channel_new(struct ssh *, char *, int, int, int, int,
275: u_int, u_int, int, char *, int);
276: void channel_set_fds(struct ssh *, int, int, int, int, int,
277: int, int, u_int);
278: void channel_free(struct ssh *, Channel *);
279: void channel_free_all(struct ssh *);
280: void channel_stop_listening(struct ssh *);
281:
282: void channel_send_open(struct ssh *, int);
283: void channel_request_start(struct ssh *, int, char *, int);
284: void channel_register_cleanup(struct ssh *, int,
285: channel_callback_fn *, int);
286: void channel_register_open_confirm(struct ssh *, int,
287: channel_open_fn *, void *);
288: void channel_register_filter(struct ssh *, int, channel_infilter_fn *,
289: channel_outfilter_fn *, channel_filter_cleanup_fn *, void *);
290: void channel_register_status_confirm(struct ssh *, int,
291: channel_confirm_cb *, channel_confirm_abandon_cb *, void *);
292: void channel_cancel_cleanup(struct ssh *, int);
1.138 djm 293: int channel_close_fd(struct ssh *, Channel *, int *);
1.128 djm 294: void channel_send_window_changes(struct ssh *);
1.119 markus 295:
296: /* mux proxy support */
297:
1.128 djm 298: int channel_proxy_downstream(struct ssh *, Channel *mc);
1.126 markus 299: int channel_proxy_upstream(Channel *, int, u_int32_t, struct ssh *);
1.22 markus 300:
1.35 markus 301: /* protocol handler */
1.7 markus 302:
1.126 markus 303: int channel_input_data(int, u_int32_t, struct ssh *);
304: int channel_input_extended_data(int, u_int32_t, struct ssh *);
305: int channel_input_ieof(int, u_int32_t, struct ssh *);
306: int channel_input_oclose(int, u_int32_t, struct ssh *);
307: int channel_input_open_confirmation(int, u_int32_t, struct ssh *);
308: int channel_input_open_failure(int, u_int32_t, struct ssh *);
309: int channel_input_port_open(int, u_int32_t, struct ssh *);
310: int channel_input_window_adjust(int, u_int32_t, struct ssh *);
311: int channel_input_status_confirm(int, u_int32_t, struct ssh *);
1.7 markus 312:
1.35 markus 313: /* file descriptor handling (read/write) */
1.140 djm 314: struct pollfd;
1.7 markus 315:
1.140 djm 316: void channel_prepare_poll(struct ssh *, struct pollfd **,
317: u_int *, u_int *, u_int, time_t *);
318: void channel_after_poll(struct ssh *, struct pollfd *, u_int);
1.128 djm 319: void channel_output_poll(struct ssh *);
1.42 markus 320:
1.128 djm 321: int channel_not_very_much_buffered_data(struct ssh *);
322: void channel_close_all(struct ssh *);
323: int channel_still_open(struct ssh *);
1.132 djm 324: const char *channel_format_extended_usage(const Channel *);
1.128 djm 325: char *channel_open_message(struct ssh *);
326: int channel_find_open(struct ssh *);
1.7 markus 327:
1.47 markus 328: /* tcp forwarding */
1.115 millert 329: struct Forward;
330: struct ForwardOptions;
1.128 djm 331: void channel_set_af(struct ssh *, int af);
1.131 djm 332: void channel_permit_all(struct ssh *, int);
333: void channel_add_permission(struct ssh *, int, int, char *, int);
334: void channel_clear_permission(struct ssh *, int, int);
335: void channel_disable_admin(struct ssh *, int);
336: void channel_update_permission(struct ssh *, int, int);
1.128 djm 337: Channel *channel_connect_to_port(struct ssh *, const char *, u_short,
338: char *, char *, int *, const char **);
339: Channel *channel_connect_to_path(struct ssh *, const char *, char *, char *);
340: Channel *channel_connect_stdio_fwd(struct ssh *, const char*,
1.138 djm 341: u_short, int, int, int);
1.128 djm 342: Channel *channel_connect_by_listen_address(struct ssh *, const char *,
343: u_short, char *, char *);
344: Channel *channel_connect_by_listen_path(struct ssh *, const char *,
345: char *, char *);
346: int channel_request_remote_forwarding(struct ssh *, struct Forward *);
347: int channel_setup_local_fwd_listener(struct ssh *, struct Forward *,
348: struct ForwardOptions *);
349: int channel_request_rforward_cancel(struct ssh *, struct Forward *);
350: int channel_setup_remote_fwd_listener(struct ssh *, struct Forward *,
351: int *, struct ForwardOptions *);
352: int channel_cancel_rport_listener(struct ssh *, struct Forward *);
353: int channel_cancel_lport_listener(struct ssh *, struct Forward *,
354: int, struct ForwardOptions *);
1.108 dtucker 355: int permitopen_port(const char *);
1.7 markus 356:
1.35 markus 357: /* x11 forwarding */
1.7 markus 358:
1.128 djm 359: void channel_set_x11_refuse_time(struct ssh *, u_int);
360: int x11_connect_display(struct ssh *);
361: int x11_create_display_inet(struct ssh *, int, int, int, u_int *, int **);
362: void x11_request_forwarding_with_spoofing(struct ssh *, int,
363: const char *, const char *, const char *, int);
1.7 markus 364:
1.35 markus 365: /* channel close */
1.8 markus 366:
1.128 djm 367: int chan_is_dead(struct ssh *, Channel *, int);
368: void chan_mark_dead(struct ssh *, Channel *);
1.42 markus 369:
1.58 markus 370: /* channel events */
1.31 beck 371:
1.128 djm 372: void chan_rcvd_oclose(struct ssh *, Channel *);
373: void chan_rcvd_eow(struct ssh *, Channel *);
374: void chan_read_failed(struct ssh *, Channel *);
375: void chan_ibuf_empty(struct ssh *, Channel *);
376: void chan_rcvd_ieof(struct ssh *, Channel *);
377: void chan_write_failed(struct ssh *, Channel *);
378: void chan_obuf_empty(struct ssh *, Channel *);
1.7 markus 379:
1.1 markus 380: #endif
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