/* * * packet.h * * Author: Tatu Ylonen * * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * * Created: Sat Mar 18 02:02:14 1995 ylo * * Interface for the packet protocol functions. * */ /* RCSID("$Id$"); */ #ifndef PACKET_H #define PACKET_H #include "config.h" #ifdef HAVE_OPENSSL #include #endif #ifdef HAVE_SSL #include #endif /* * Sets the socket used for communication. Disables encryption until * packet_set_encryption_key is called. It is permissible that fd_in and * fd_out are the same descriptor; in that case it is assumed to be a socket. */ void packet_set_connection(int fd_in, int fd_out); /* Puts the connection file descriptors into non-blocking mode. */ void packet_set_nonblocking(void); /* Returns the file descriptor used for input. */ int packet_get_connection_in(void); /* Returns the file descriptor used for output. */ int packet_get_connection_out(void); /* * Closes the connection (both descriptors) and clears and frees internal * data structures. */ void packet_close(void); /* * Causes any further packets to be encrypted using the given key. The same * key is used for both sending and reception. However, both directions are * encrypted independently of each other. Cipher types are defined in ssh.h. */ void packet_set_encryption_key(const unsigned char *key, unsigned int keylen, int cipher_type); /* * Sets remote side protocol flags for the current connection. This can be * called at any time. */ void packet_set_protocol_flags(unsigned int flags); /* Returns the remote protocol flags set earlier by the above function. */ unsigned int packet_get_protocol_flags(void); /* Enables compression in both directions starting from the next packet. */ void packet_start_compression(int level); /* * Informs that the current session is interactive. Sets IP flags for * optimal performance in interactive use. */ void packet_set_interactive(int interactive, int keepalives); /* Returns true if the current connection is interactive. */ int packet_is_interactive(void); /* Starts constructing a packet to send. */ void packet_start(int type); /* Appends a character to the packet data. */ void packet_put_char(int ch); /* Appends an integer to the packet data. */ void packet_put_int(unsigned int value); /* Appends an arbitrary precision integer to packet data. */ void packet_put_bignum(BIGNUM * value); /* Appends a string to packet data. */ void packet_put_string(const char *buf, unsigned int len); /* * Finalizes and sends the packet. If the encryption key has been set, * encrypts the packet before sending. */ void packet_send(void); /* Waits until a packet has been received, and returns its type. */ int packet_read(int *payload_len_ptr); /* * Waits until a packet has been received, verifies that its type matches * that given, and gives a fatal error and exits if there is a mismatch. */ void packet_read_expect(int *payload_len_ptr, int type); /* * Checks if a full packet is available in the data received so far via * packet_process_incoming. If so, reads the packet; otherwise returns * SSH_MSG_NONE. This does not wait for data from the connection. * SSH_MSG_DISCONNECT is handled specially here. Also, SSH_MSG_IGNORE * messages are skipped by this function and are never returned to higher * levels. */ int packet_read_poll(int *packet_len_ptr); /* * Buffers the given amount of input characters. This is intended to be used * together with packet_read_poll. */ void packet_process_incoming(const char *buf, unsigned int len); /* Returns a character (0-255) from the packet data. */ unsigned int packet_get_char(void); /* Returns an integer from the packet data. */ unsigned int packet_get_int(void); /* * Returns an arbitrary precision integer from the packet data. The integer * must have been initialized before this call. */ void packet_get_bignum(BIGNUM * value, int *length_ptr); /* * Returns a string from the packet data. The string is allocated using * xmalloc; it is the responsibility of the calling program to free it when * no longer needed. The length_ptr argument may be NULL, or point to an * integer into which the length of the string is stored. */ char *packet_get_string(unsigned int *length_ptr); /* * Logs the error in syslog using LOG_INFO, constructs and sends a disconnect * packet, closes the connection, and exits. This function never returns. * The error message should not contain a newline. The total length of the * message must not exceed 1024 bytes. */ void packet_disconnect(const char *fmt,...); /* * Sends a diagnostic message to the other side. This message can be sent at * any time (but not while constructing another message). The message is * printed immediately, but only if the client is being executed in verbose * mode. These messages are primarily intended to ease debugging * authentication problems. The total length of the message must not exceed * 1024 bytes. This will automatically call packet_write_wait. If the * remote side protocol flags do not indicate that it supports SSH_MSG_DEBUG, * this will do nothing. */ void packet_send_debug(const char *fmt,...); /* Checks if there is any buffered output, and tries to write some of the output. */ void packet_write_poll(void); /* Waits until all pending output data has been written. */ void packet_write_wait(void); /* Returns true if there is buffered data to write to the connection. */ int packet_have_data_to_write(void); /* Returns true if there is not too much data to write to the connection. */ int packet_not_very_much_data_to_write(void); /* maximum packet size, requested by client with SSH_CMSG_MAX_PACKET_SIZE */ extern int max_packet_size; int packet_set_maxsize(int s); #define packet_get_maxsize() max_packet_size /* Stores tty modes from the fd into current packet. */ void tty_make_modes(int fd); /* Parses tty modes for the fd from the current packet. */ void tty_parse_modes(int fd, int *n_bytes_ptr); #define packet_integrity_check(payload_len, expected_len, type) \ do { \ int _p = (payload_len), _e = (expected_len); \ if (_p != _e) { \ log("Packet integrity error (%d != %d) at %s:%d", \ _p, _e, __FILE__, __LINE__); \ packet_disconnect("Packet integrity error. (%d)", (type)); \ } \ } while (0) #endif /* PACKET_H */