| /* |
| * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| * All rights reserved |
| * Interface for the packet protocol functions. |
| * |
| * As far as I am concerned, the code I have written for this software |
| * can be used freely for any purpose. Any derived versions of this |
| * software must be clearly marked as such, and if the derived work is |
| * incompatible with the protocol description in the RFC file, it must be |
| * called by a name other than "ssh" or "Secure Shell". |
| */ |
| |
| /* RCSID("$OpenBSD: packet.h,v 1.20 2001/02/28 09:57:07 markus Exp $"); */ |
| |
| #ifndef PACKET_H |
| #define PACKET_H |
| |
| #include <openssl/bn.h> |
| |
| /* |
| * 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 u_char *key, u_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(u_int flags); |
| |
| /* Returns the remote protocol flags set earlier by the above function. */ |
| u_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); |
| |
| /* 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(u_int value); |
| |
| /* Appends an arbitrary precision integer to packet data. */ |
| void packet_put_bignum(BIGNUM * value); |
| void packet_put_bignum2(BIGNUM * value); |
| |
| /* Appends a string to packet data. */ |
| void packet_put_string(const char *buf, u_int len); |
| void packet_put_cstring(const char *str); |
| void packet_put_raw(const char *buf, u_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, u_int len); |
| |
| /* Returns a character (0-255) from the packet data. */ |
| u_int packet_get_char(void); |
| |
| /* Returns an integer from the packet data. */ |
| u_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); |
| void packet_get_bignum2(BIGNUM * value, int *length_ptr); |
| char *packet_get_raw(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(u_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,...) __attribute__((format(printf, 1, 2))); |
| |
| /* |
| * 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,...) __attribute__((format(printf, 1, 2))); |
| |
| /* 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) |
| |
| #define packet_done() \ |
| do { \ |
| int _len = packet_remaining(); \ |
| if (_len > 0) { \ |
| log("Packet integrity error (%d bytes remaining) at %s:%d", \ |
| _len ,__FILE__, __LINE__); \ |
| packet_disconnect("Packet integrity error."); \ |
| } \ |
| } while (0) |
| |
| /* remote host is connected via a socket/ipv4 */ |
| int packet_connection_is_on_socket(void); |
| int packet_connection_is_ipv4(void); |
| |
| /* enable SSH2 packet format */ |
| void packet_set_ssh2_format(void); |
| |
| /* returns remaining payload bytes */ |
| int packet_remaining(void); |
| |
| /* append an ignore message */ |
| void packet_inject_ignore(int sumlen); |
| |
| #endif /* PACKET_H */ |