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Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 *
3 * packet.h
4 *
5 * Author: Tatu Ylonen <ylo@cs.hut.fi>
6 *
7 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
8 * All rights reserved
9 *
10 * Created: Sat Mar 18 02:02:14 1995 ylo
11 *
12 * Interface for the packet protocol functions.
13 *
14 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100015
Damien Miller34132e52000-01-14 15:45:46 +110016/* RCSID("$Id: packet.h,v 1.9 2000/01/14 04:45:51 damien Exp $"); */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100017
18#ifndef PACKET_H
19#define PACKET_H
20
Damien Miller3bd49ec1999-11-15 15:40:55 +110021#include "config.h"
22
Damien Miller7f6ea021999-10-28 13:25:17 +100023#ifdef HAVE_OPENSSL
Damien Millerd4a8b7e1999-10-27 13:42:43 +100024#include <openssl/bn.h>
Damien Miller7f6ea021999-10-28 13:25:17 +100025#endif
26#ifdef HAVE_SSL
27#include <ssl/bn.h>
28#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +100029
Damien Miller5428f641999-11-25 11:54:57 +110030/*
31 * Sets the socket used for communication. Disables encryption until
32 * packet_set_encryption_key is called. It is permissible that fd_in and
33 * fd_out are the same descriptor; in that case it is assumed to be a socket.
34 */
Damien Miller95def091999-11-25 00:26:21 +110035void packet_set_connection(int fd_in, int fd_out);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100036
37/* Puts the connection file descriptors into non-blocking mode. */
Damien Miller95def091999-11-25 00:26:21 +110038void packet_set_nonblocking(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100039
40/* Returns the file descriptor used for input. */
Damien Miller95def091999-11-25 00:26:21 +110041int packet_get_connection_in(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100042
43/* Returns the file descriptor used for output. */
Damien Miller95def091999-11-25 00:26:21 +110044int packet_get_connection_out(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100045
Damien Miller5428f641999-11-25 11:54:57 +110046/*
47 * Closes the connection (both descriptors) and clears and frees internal
48 * data structures.
49 */
Damien Miller95def091999-11-25 00:26:21 +110050void packet_close(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100051
Damien Miller5428f641999-11-25 11:54:57 +110052/*
53 * Causes any further packets to be encrypted using the given key. The same
54 * key is used for both sending and reception. However, both directions are
55 * encrypted independently of each other. Cipher types are defined in ssh.h.
56 */
Damien Miller95def091999-11-25 00:26:21 +110057void
58packet_set_encryption_key(const unsigned char *key, unsigned int keylen,
59 int cipher_type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100060
Damien Miller5428f641999-11-25 11:54:57 +110061/*
62 * Sets remote side protocol flags for the current connection. This can be
63 * called at any time.
64 */
Damien Miller95def091999-11-25 00:26:21 +110065void packet_set_protocol_flags(unsigned int flags);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100066
67/* Returns the remote protocol flags set earlier by the above function. */
68unsigned int packet_get_protocol_flags(void);
69
70/* Enables compression in both directions starting from the next packet. */
Damien Miller95def091999-11-25 00:26:21 +110071void packet_start_compression(int level);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100072
Damien Miller5428f641999-11-25 11:54:57 +110073/*
74 * Informs that the current session is interactive. Sets IP flags for
75 * optimal performance in interactive use.
76 */
Damien Miller95def091999-11-25 00:26:21 +110077void packet_set_interactive(int interactive, int keepalives);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100078
79/* Returns true if the current connection is interactive. */
Damien Miller95def091999-11-25 00:26:21 +110080int packet_is_interactive(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100081
82/* Starts constructing a packet to send. */
Damien Miller95def091999-11-25 00:26:21 +110083void packet_start(int type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100084
85/* Appends a character to the packet data. */
Damien Miller95def091999-11-25 00:26:21 +110086void packet_put_char(int ch);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100087
88/* Appends an integer to the packet data. */
Damien Miller95def091999-11-25 00:26:21 +110089void packet_put_int(unsigned int value);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100090
91/* Appends an arbitrary precision integer to packet data. */
Damien Miller95def091999-11-25 00:26:21 +110092void packet_put_bignum(BIGNUM * value);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100093
94/* Appends a string to packet data. */
Damien Miller95def091999-11-25 00:26:21 +110095void packet_put_string(const char *buf, unsigned int len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100096
Damien Miller5428f641999-11-25 11:54:57 +110097/*
98 * Finalizes and sends the packet. If the encryption key has been set,
99 * encrypts the packet before sending.
100 */
Damien Miller95def091999-11-25 00:26:21 +1100101void packet_send(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000102
103/* Waits until a packet has been received, and returns its type. */
Damien Miller95def091999-11-25 00:26:21 +1100104int packet_read(int *payload_len_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000105
Damien Miller5428f641999-11-25 11:54:57 +1100106/*
107 * Waits until a packet has been received, verifies that its type matches
108 * that given, and gives a fatal error and exits if there is a mismatch.
109 */
Damien Miller95def091999-11-25 00:26:21 +1100110void packet_read_expect(int *payload_len_ptr, int type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000111
Damien Miller5428f641999-11-25 11:54:57 +1100112/*
113 * Checks if a full packet is available in the data received so far via
114 * packet_process_incoming. If so, reads the packet; otherwise returns
115 * SSH_MSG_NONE. This does not wait for data from the connection.
116 * SSH_MSG_DISCONNECT is handled specially here. Also, SSH_MSG_IGNORE
117 * messages are skipped by this function and are never returned to higher
118 * levels.
119 */
Damien Miller95def091999-11-25 00:26:21 +1100120int packet_read_poll(int *packet_len_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000121
Damien Miller5428f641999-11-25 11:54:57 +1100122/*
123 * Buffers the given amount of input characters. This is intended to be used
124 * together with packet_read_poll.
125 */
Damien Miller95def091999-11-25 00:26:21 +1100126void packet_process_incoming(const char *buf, unsigned int len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000127
128/* Returns a character (0-255) from the packet data. */
129unsigned int packet_get_char(void);
130
131/* Returns an integer from the packet data. */
132unsigned int packet_get_int(void);
133
Damien Miller5428f641999-11-25 11:54:57 +1100134/*
135 * Returns an arbitrary precision integer from the packet data. The integer
136 * must have been initialized before this call.
137 */
Damien Miller95def091999-11-25 00:26:21 +1100138void packet_get_bignum(BIGNUM * value, int *length_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000139
Damien Miller5428f641999-11-25 11:54:57 +1100140/*
141 * Returns a string from the packet data. The string is allocated using
142 * xmalloc; it is the responsibility of the calling program to free it when
143 * no longer needed. The length_ptr argument may be NULL, or point to an
144 * integer into which the length of the string is stored.
145 */
Damien Miller95def091999-11-25 00:26:21 +1100146char *packet_get_string(unsigned int *length_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000147
Damien Miller5428f641999-11-25 11:54:57 +1100148/*
149 * Logs the error in syslog using LOG_INFO, constructs and sends a disconnect
150 * packet, closes the connection, and exits. This function never returns.
151 * The error message should not contain a newline. The total length of the
152 * message must not exceed 1024 bytes.
153 */
Damien Miller68e45de1999-12-27 23:54:55 +1100154void packet_disconnect(const char *fmt,...) __attribute__((format(printf, 1, 2)));;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000155
Damien Miller5428f641999-11-25 11:54:57 +1100156/*
157 * Sends a diagnostic message to the other side. This message can be sent at
158 * any time (but not while constructing another message). The message is
159 * printed immediately, but only if the client is being executed in verbose
160 * mode. These messages are primarily intended to ease debugging
161 * authentication problems. The total length of the message must not exceed
162 * 1024 bytes. This will automatically call packet_write_wait. If the
163 * remote side protocol flags do not indicate that it supports SSH_MSG_DEBUG,
164 * this will do nothing.
165 */
Damien Miller68e45de1999-12-27 23:54:55 +1100166void packet_send_debug(const char *fmt,...) __attribute__((format(printf, 1, 2)));;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000167
Damien Miller5428f641999-11-25 11:54:57 +1100168/* Checks if there is any buffered output, and tries to write some of the output. */
Damien Miller95def091999-11-25 00:26:21 +1100169void packet_write_poll(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000170
171/* Waits until all pending output data has been written. */
Damien Miller95def091999-11-25 00:26:21 +1100172void packet_write_wait(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000173
174/* Returns true if there is buffered data to write to the connection. */
Damien Miller95def091999-11-25 00:26:21 +1100175int packet_have_data_to_write(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000176
177/* Returns true if there is not too much data to write to the connection. */
Damien Miller95def091999-11-25 00:26:21 +1100178int packet_not_very_much_data_to_write(void);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000179
Damien Miller6162d121999-11-21 13:23:52 +1100180/* maximum packet size, requested by client with SSH_CMSG_MAX_PACKET_SIZE */
181extern int max_packet_size;
Damien Miller95def091999-11-25 00:26:21 +1100182int packet_set_maxsize(int s);
Damien Miller6162d121999-11-21 13:23:52 +1100183#define packet_get_maxsize() max_packet_size
184
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000185/* Stores tty modes from the fd into current packet. */
Damien Miller95def091999-11-25 00:26:21 +1100186void tty_make_modes(int fd);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000187
188/* Parses tty modes for the fd from the current packet. */
Damien Miller95def091999-11-25 00:26:21 +1100189void tty_parse_modes(int fd, int *n_bytes_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000190
191#define packet_integrity_check(payload_len, expected_len, type) \
192do { \
193 int _p = (payload_len), _e = (expected_len); \
194 if (_p != _e) { \
195 log("Packet integrity error (%d != %d) at %s:%d", \
196 _p, _e, __FILE__, __LINE__); \
197 packet_disconnect("Packet integrity error. (%d)", (type)); \
198 } \
199} while (0)
200
Damien Miller34132e52000-01-14 15:45:46 +1100201/* remote host is connected via a socket/ipv4 */
202int packet_connection_is_on_socket(void);
203int packet_connection_is_ipv4(void);
204
Damien Miller95def091999-11-25 00:26:21 +1100205#endif /* PACKET_H */