Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1 | /* |
| 2 | |
| 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 | */ |
| 15 | |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame^] | 16 | /* RCSID("$Id: packet.h,v 1.5 1999/11/21 02:23:53 damien Exp $"); */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 17 | |
| 18 | #ifndef PACKET_H |
| 19 | #define PACKET_H |
| 20 | |
Damien Miller | 3bd49ec | 1999-11-15 15:40:55 +1100 | [diff] [blame] | 21 | #include "config.h" |
| 22 | |
Damien Miller | 7f6ea02 | 1999-10-28 13:25:17 +1000 | [diff] [blame] | 23 | #ifdef HAVE_OPENSSL |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 24 | #include <openssl/bn.h> |
Damien Miller | 7f6ea02 | 1999-10-28 13:25:17 +1000 | [diff] [blame] | 25 | #endif |
| 26 | #ifdef HAVE_SSL |
| 27 | #include <ssl/bn.h> |
| 28 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 29 | |
| 30 | /* Sets the socket used for communication. Disables encryption until |
| 31 | packet_set_encryption_key is called. It is permissible that fd_in |
| 32 | and fd_out are the same descriptor; in that case it is assumed to |
| 33 | be a socket. */ |
| 34 | void packet_set_connection(int fd_in, int fd_out); |
| 35 | |
| 36 | /* Puts the connection file descriptors into non-blocking mode. */ |
| 37 | void packet_set_nonblocking(void); |
| 38 | |
| 39 | /* Returns the file descriptor used for input. */ |
| 40 | int packet_get_connection_in(void); |
| 41 | |
| 42 | /* Returns the file descriptor used for output. */ |
| 43 | int packet_get_connection_out(void); |
| 44 | |
| 45 | /* Closes the connection (both descriptors) and clears and frees |
| 46 | internal data structures. */ |
| 47 | void packet_close(void); |
| 48 | |
| 49 | /* Causes any further packets to be encrypted using the given key. The same |
| 50 | key is used for both sending and reception. However, both directions |
| 51 | are encrypted independently of each other. Cipher types are |
| 52 | defined in ssh.h. */ |
| 53 | void packet_set_encryption_key(const unsigned char *key, unsigned int keylen, |
Damien Miller | 7e8e820 | 1999-11-16 13:37:16 +1100 | [diff] [blame] | 54 | int cipher_type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 55 | |
| 56 | /* Sets remote side protocol flags for the current connection. This can |
| 57 | be called at any time. */ |
| 58 | void packet_set_protocol_flags(unsigned int flags); |
| 59 | |
| 60 | /* Returns the remote protocol flags set earlier by the above function. */ |
| 61 | unsigned int packet_get_protocol_flags(void); |
| 62 | |
| 63 | /* Enables compression in both directions starting from the next packet. */ |
| 64 | void packet_start_compression(int level); |
| 65 | |
| 66 | /* Informs that the current session is interactive. Sets IP flags for optimal |
| 67 | performance in interactive use. */ |
| 68 | void packet_set_interactive(int interactive, int keepalives); |
| 69 | |
| 70 | /* Returns true if the current connection is interactive. */ |
| 71 | int packet_is_interactive(void); |
| 72 | |
| 73 | /* Starts constructing a packet to send. */ |
| 74 | void packet_start(int type); |
| 75 | |
| 76 | /* Appends a character to the packet data. */ |
| 77 | void packet_put_char(int ch); |
| 78 | |
| 79 | /* Appends an integer to the packet data. */ |
| 80 | void packet_put_int(unsigned int value); |
| 81 | |
| 82 | /* Appends an arbitrary precision integer to packet data. */ |
| 83 | void packet_put_bignum(BIGNUM *value); |
| 84 | |
| 85 | /* Appends a string to packet data. */ |
| 86 | void packet_put_string(const char *buf, unsigned int len); |
| 87 | |
| 88 | /* Finalizes and sends the packet. If the encryption key has been set, |
| 89 | encrypts the packet before sending. */ |
| 90 | void packet_send(void); |
| 91 | |
| 92 | /* Waits until a packet has been received, and returns its type. */ |
| 93 | int packet_read(int *payload_len_ptr); |
| 94 | |
| 95 | /* Waits until a packet has been received, verifies that its type matches |
| 96 | that given, and gives a fatal error and exits if there is a mismatch. */ |
| 97 | void packet_read_expect(int *payload_len_ptr, int type); |
| 98 | |
| 99 | /* Checks if a full packet is available in the data received so far via |
| 100 | packet_process_incoming. If so, reads the packet; otherwise returns |
| 101 | SSH_MSG_NONE. This does not wait for data from the connection. |
| 102 | |
| 103 | SSH_MSG_DISCONNECT is handled specially here. Also, |
| 104 | SSH_MSG_IGNORE messages are skipped by this function and are never returned |
| 105 | to higher levels. */ |
| 106 | int packet_read_poll(int *packet_len_ptr); |
| 107 | |
| 108 | /* Buffers the given amount of input characters. This is intended to be |
| 109 | used together with packet_read_poll. */ |
| 110 | void packet_process_incoming(const char *buf, unsigned int len); |
| 111 | |
| 112 | /* Returns a character (0-255) from the packet data. */ |
| 113 | unsigned int packet_get_char(void); |
| 114 | |
| 115 | /* Returns an integer from the packet data. */ |
| 116 | unsigned int packet_get_int(void); |
| 117 | |
| 118 | /* Returns an arbitrary precision integer from the packet data. The integer |
| 119 | must have been initialized before this call. */ |
| 120 | void packet_get_bignum(BIGNUM *value, int *length_ptr); |
| 121 | |
| 122 | /* Returns a string from the packet data. The string is allocated using |
| 123 | xmalloc; it is the responsibility of the calling program to free it when |
| 124 | no longer needed. The length_ptr argument may be NULL, or point to an |
| 125 | integer into which the length of the string is stored. */ |
| 126 | char *packet_get_string(unsigned int *length_ptr); |
| 127 | |
| 128 | /* Logs the error in syslog using LOG_INFO, constructs and sends a disconnect |
| 129 | packet, closes the connection, and exits. This function never returns. |
| 130 | The error message should not contain a newline. The total length of the |
| 131 | message must not exceed 1024 bytes. */ |
| 132 | void packet_disconnect(const char *fmt, ...); |
| 133 | |
| 134 | /* Sends a diagnostic message to the other side. This message |
| 135 | can be sent at any time (but not while constructing another message). |
| 136 | The message is printed immediately, but only if the client is being |
| 137 | executed in verbose mode. These messages are primarily intended to |
| 138 | ease debugging authentication problems. The total length of the message |
| 139 | must not exceed 1024 bytes. This will automatically call |
| 140 | packet_write_wait. If the remote side protocol flags do not indicate |
| 141 | that it supports SSH_MSG_DEBUG, this will do nothing. */ |
| 142 | void packet_send_debug(const char *fmt, ...); |
| 143 | |
| 144 | /* Checks if there is any buffered output, and tries to write some of the |
| 145 | output. */ |
| 146 | void packet_write_poll(void); |
| 147 | |
| 148 | /* Waits until all pending output data has been written. */ |
| 149 | void packet_write_wait(void); |
| 150 | |
| 151 | /* Returns true if there is buffered data to write to the connection. */ |
| 152 | int packet_have_data_to_write(void); |
| 153 | |
| 154 | /* Returns true if there is not too much data to write to the connection. */ |
| 155 | int packet_not_very_much_data_to_write(void); |
| 156 | |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame^] | 157 | /* maximum packet size, requested by client with SSH_CMSG_MAX_PACKET_SIZE */ |
| 158 | extern int max_packet_size; |
| 159 | int packet_set_maxsize(int s); |
| 160 | #define packet_get_maxsize() max_packet_size |
| 161 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 162 | /* Stores tty modes from the fd into current packet. */ |
| 163 | void tty_make_modes(int fd); |
| 164 | |
| 165 | /* Parses tty modes for the fd from the current packet. */ |
| 166 | void tty_parse_modes(int fd, int *n_bytes_ptr); |
| 167 | |
| 168 | #define packet_integrity_check(payload_len, expected_len, type) \ |
| 169 | do { \ |
| 170 | int _p = (payload_len), _e = (expected_len); \ |
| 171 | if (_p != _e) { \ |
| 172 | log("Packet integrity error (%d != %d) at %s:%d", \ |
| 173 | _p, _e, __FILE__, __LINE__); \ |
| 174 | packet_disconnect("Packet integrity error. (%d)", (type)); \ |
| 175 | } \ |
| 176 | } while (0) |
| 177 | |
| 178 | #endif /* PACKET_H */ |