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Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 * Author: Tatu Ylonen <ylo@cs.hut.fi>
Damien Miller95def091999-11-25 00:26:21 +11003 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11005 * Interface for the packet protocol functions.
Damien Miller4af51302000-04-16 11:18:38 +10006 *
Damien Millere4340be2000-09-16 13:29:08 +11007 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
Damien Miller95def091999-11-25 00:26:21 +110012 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100013
Ben Lindstrom46c16222000-12-22 01:43:59 +000014/* RCSID("$OpenBSD: packet.h,v 1.18 2000/12/19 23:17:57 markus Exp $"); */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100015
16#ifndef PACKET_H
17#define PACKET_H
18
19#include <openssl/bn.h>
Damien Millerd4a8b7e1999-10-27 13:42:43 +100020
Damien Miller5428f641999-11-25 11:54:57 +110021/*
22 * Sets the socket used for communication. Disables encryption until
23 * packet_set_encryption_key is called. It is permissible that fd_in and
24 * fd_out are the same descriptor; in that case it is assumed to be a socket.
25 */
Damien Miller95def091999-11-25 00:26:21 +110026void packet_set_connection(int fd_in, int fd_out);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100027
28/* Puts the connection file descriptors into non-blocking mode. */
Damien Miller95def091999-11-25 00:26:21 +110029void packet_set_nonblocking(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100030
31/* Returns the file descriptor used for input. */
Damien Miller95def091999-11-25 00:26:21 +110032int packet_get_connection_in(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100033
34/* Returns the file descriptor used for output. */
Damien Miller95def091999-11-25 00:26:21 +110035int packet_get_connection_out(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100036
Damien Miller5428f641999-11-25 11:54:57 +110037/*
38 * Closes the connection (both descriptors) and clears and frees internal
39 * data structures.
40 */
Damien Miller95def091999-11-25 00:26:21 +110041void packet_close(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100042
Damien Miller5428f641999-11-25 11:54:57 +110043/*
44 * Causes any further packets to be encrypted using the given key. The same
45 * key is used for both sending and reception. However, both directions are
46 * encrypted independently of each other. Cipher types are defined in ssh.h.
47 */
Damien Miller4af51302000-04-16 11:18:38 +100048void
Ben Lindstrom46c16222000-12-22 01:43:59 +000049packet_set_encryption_key(const u_char *key, u_int keylen,
Damien Miller95def091999-11-25 00:26:21 +110050 int cipher_type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100051
Damien Miller5428f641999-11-25 11:54:57 +110052/*
53 * Sets remote side protocol flags for the current connection. This can be
54 * called at any time.
55 */
Ben Lindstrom46c16222000-12-22 01:43:59 +000056void packet_set_protocol_flags(u_int flags);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100057
58/* Returns the remote protocol flags set earlier by the above function. */
Ben Lindstrom46c16222000-12-22 01:43:59 +000059u_int packet_get_protocol_flags(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100060
61/* Enables compression in both directions starting from the next packet. */
Damien Miller95def091999-11-25 00:26:21 +110062void packet_start_compression(int level);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100063
Damien Miller5428f641999-11-25 11:54:57 +110064/*
65 * Informs that the current session is interactive. Sets IP flags for
66 * optimal performance in interactive use.
67 */
Damien Miller95def091999-11-25 00:26:21 +110068void packet_set_interactive(int interactive, int keepalives);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100069
70/* Returns true if the current connection is interactive. */
Damien Miller95def091999-11-25 00:26:21 +110071int packet_is_interactive(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100072
73/* Starts constructing a packet to send. */
Damien Miller95def091999-11-25 00:26:21 +110074void packet_start(int type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100075
76/* Appends a character to the packet data. */
Damien Miller95def091999-11-25 00:26:21 +110077void packet_put_char(int ch);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100078
79/* Appends an integer to the packet data. */
Ben Lindstrom46c16222000-12-22 01:43:59 +000080void packet_put_int(u_int value);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100081
82/* Appends an arbitrary precision integer to packet data. */
Damien Miller95def091999-11-25 00:26:21 +110083void packet_put_bignum(BIGNUM * value);
Damien Miller33b13562000-04-04 14:38:59 +100084void packet_put_bignum2(BIGNUM * value);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100085
86/* Appends a string to packet data. */
Ben Lindstrom46c16222000-12-22 01:43:59 +000087void packet_put_string(const char *buf, u_int len);
Damien Miller33b13562000-04-04 14:38:59 +100088void packet_put_cstring(const char *str);
Ben Lindstrom46c16222000-12-22 01:43:59 +000089void packet_put_raw(const char *buf, u_int len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100090
Damien Miller5428f641999-11-25 11:54:57 +110091/*
92 * Finalizes and sends the packet. If the encryption key has been set,
93 * encrypts the packet before sending.
94 */
Damien Miller95def091999-11-25 00:26:21 +110095void packet_send(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100096
97/* Waits until a packet has been received, and returns its type. */
Damien Miller95def091999-11-25 00:26:21 +110098int packet_read(int *payload_len_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100099
Damien Miller5428f641999-11-25 11:54:57 +1100100/*
101 * Waits until a packet has been received, verifies that its type matches
102 * that given, and gives a fatal error and exits if there is a mismatch.
103 */
Damien Miller95def091999-11-25 00:26:21 +1100104void packet_read_expect(int *payload_len_ptr, int type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000105
Damien Miller5428f641999-11-25 11:54:57 +1100106/*
107 * Checks if a full packet is available in the data received so far via
108 * packet_process_incoming. If so, reads the packet; otherwise returns
109 * SSH_MSG_NONE. This does not wait for data from the connection.
110 * SSH_MSG_DISCONNECT is handled specially here. Also, SSH_MSG_IGNORE
111 * messages are skipped by this function and are never returned to higher
112 * levels.
113 */
Damien Miller95def091999-11-25 00:26:21 +1100114int packet_read_poll(int *packet_len_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000115
Damien Miller5428f641999-11-25 11:54:57 +1100116/*
117 * Buffers the given amount of input characters. This is intended to be used
118 * together with packet_read_poll.
119 */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000120void packet_process_incoming(const char *buf, u_int len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000121
122/* Returns a character (0-255) from the packet data. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000123u_int packet_get_char(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000124
125/* Returns an integer from the packet data. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000126u_int packet_get_int(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000127
Damien Miller5428f641999-11-25 11:54:57 +1100128/*
129 * Returns an arbitrary precision integer from the packet data. The integer
130 * must have been initialized before this call.
131 */
Damien Miller95def091999-11-25 00:26:21 +1100132void packet_get_bignum(BIGNUM * value, int *length_ptr);
Damien Miller33b13562000-04-04 14:38:59 +1000133void packet_get_bignum2(BIGNUM * value, int *length_ptr);
134char *packet_get_raw(int *length_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000135
Damien Miller5428f641999-11-25 11:54:57 +1100136/*
137 * Returns a string from the packet data. The string is allocated using
138 * xmalloc; it is the responsibility of the calling program to free it when
139 * no longer needed. The length_ptr argument may be NULL, or point to an
140 * integer into which the length of the string is stored.
141 */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000142char *packet_get_string(u_int *length_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000143
Damien Miller5428f641999-11-25 11:54:57 +1100144/*
145 * Logs the error in syslog using LOG_INFO, constructs and sends a disconnect
146 * packet, closes the connection, and exits. This function never returns.
147 * The error message should not contain a newline. The total length of the
148 * message must not exceed 1024 bytes.
149 */
Damien Miller7684ee12000-03-17 23:40:15 +1100150void packet_disconnect(const char *fmt,...) __attribute__((format(printf, 1, 2)));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000151
Damien Miller5428f641999-11-25 11:54:57 +1100152/*
153 * Sends a diagnostic message to the other side. This message can be sent at
154 * any time (but not while constructing another message). The message is
155 * printed immediately, but only if the client is being executed in verbose
156 * mode. These messages are primarily intended to ease debugging
157 * authentication problems. The total length of the message must not exceed
158 * 1024 bytes. This will automatically call packet_write_wait. If the
159 * remote side protocol flags do not indicate that it supports SSH_MSG_DEBUG,
160 * this will do nothing.
161 */
Damien Miller7684ee12000-03-17 23:40:15 +1100162void packet_send_debug(const char *fmt,...) __attribute__((format(printf, 1, 2)));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000163
Damien Miller5428f641999-11-25 11:54:57 +1100164/* Checks if there is any buffered output, and tries to write some of the output. */
Damien Miller95def091999-11-25 00:26:21 +1100165void packet_write_poll(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000166
167/* Waits until all pending output data has been written. */
Damien Miller95def091999-11-25 00:26:21 +1100168void packet_write_wait(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000169
170/* Returns true if there is buffered data to write to the connection. */
Damien Miller95def091999-11-25 00:26:21 +1100171int packet_have_data_to_write(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000172
173/* Returns true if there is not too much data to write to the connection. */
Damien Miller95def091999-11-25 00:26:21 +1100174int packet_not_very_much_data_to_write(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000175
Damien Miller6162d121999-11-21 13:23:52 +1100176/* maximum packet size, requested by client with SSH_CMSG_MAX_PACKET_SIZE */
177extern int max_packet_size;
Damien Miller95def091999-11-25 00:26:21 +1100178int packet_set_maxsize(int s);
Damien Miller6162d121999-11-21 13:23:52 +1100179#define packet_get_maxsize() max_packet_size
180
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000181/* Stores tty modes from the fd into current packet. */
Damien Miller95def091999-11-25 00:26:21 +1100182void tty_make_modes(int fd);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000183
184/* Parses tty modes for the fd from the current packet. */
Damien Miller95def091999-11-25 00:26:21 +1100185void tty_parse_modes(int fd, int *n_bytes_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000186
187#define packet_integrity_check(payload_len, expected_len, type) \
188do { \
189 int _p = (payload_len), _e = (expected_len); \
190 if (_p != _e) { \
191 log("Packet integrity error (%d != %d) at %s:%d", \
192 _p, _e, __FILE__, __LINE__); \
193 packet_disconnect("Packet integrity error. (%d)", (type)); \
194 } \
195} while (0)
196
Damien Miller4af51302000-04-16 11:18:38 +1000197#define packet_done() \
198do { \
199 int _len = packet_remaining(); \
200 if (_len > 0) { \
201 log("Packet integrity error (%d bytes remaining) at %s:%d", \
202 _len ,__FILE__, __LINE__); \
203 packet_disconnect("Packet integrity error."); \
204 } \
205} while (0)
206
Damien Miller34132e52000-01-14 15:45:46 +1100207/* remote host is connected via a socket/ipv4 */
208int packet_connection_is_on_socket(void);
209int packet_connection_is_ipv4(void);
210
Damien Miller33b13562000-04-04 14:38:59 +1000211/* enable SSH2 packet format */
212void packet_set_ssh2_format(void);
213
Damien Miller4af51302000-04-16 11:18:38 +1000214/* returns remaining payload bytes */
215int packet_remaining(void);
216
Damien Miller95def091999-11-25 00:26:21 +1100217#endif /* PACKET_H */