mirror of
https://github.com/freebsd/freebsd-src
synced 2024-07-21 18:27:22 +00:00
195 lines
9 KiB
C
195 lines
9 KiB
C
/*
|
|
* dnstap/dnstap_fstrm.h - Frame Streams protocol for dnstap
|
|
*
|
|
* Copyright (c) 2020, NLnet Labs. All rights reserved.
|
|
*
|
|
* This software is open source.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* Redistributions of source code must retain the above copyright notice,
|
|
* this list of conditions and the following disclaimer.
|
|
*
|
|
* Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* Neither the name of the NLNET LABS nor the names of its contributors may
|
|
* be used to endorse or promote products derived from this software without
|
|
* specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
|
|
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
*
|
|
* Definitions for the Frame Streams data transport protocol for
|
|
* dnstap message logs.
|
|
*/
|
|
|
|
#ifndef DNSTAP_FSTRM_H
|
|
#define DNSTAP_FSTRM_H
|
|
|
|
/* Frame Streams data transfer protocol encode for DNSTAP messages.
|
|
* The protocol looks to be specified in the libfstrm library.
|
|
*
|
|
* Quick writeup for DNSTAP usage, from reading fstrm/control.h eloquent
|
|
* comments and fstrm/control.c for some bytesize details (the content type
|
|
* length).
|
|
*
|
|
* The Frame Streams can be unidirectional or bi-directional.
|
|
* bi-directional streams use control frame types READY, ACCEPT and FINISH.
|
|
* uni-directional streams use control frame types START and STOP.
|
|
* unknown control frame types should be ignored by the receiver, they
|
|
* do not change the data frame encoding.
|
|
*
|
|
* bi-directional control frames implement a simple handshake protocol
|
|
* between sender and receiver.
|
|
*
|
|
* The uni-directional control frames have one start and one stop frame,
|
|
* before and after the data. The start frame can have a content type.
|
|
* The start and stop frames are not optional.
|
|
*
|
|
* data frames are preceded by 4byte length, bigendian.
|
|
* zero length data frames are not possible, they are an escape that
|
|
* signals the presence of a control frame.
|
|
*
|
|
* a control frame consists of 0 value in 4byte bigendian, this is really
|
|
* the data frame length, with 0 the escape sequence that indicates one
|
|
* control frame follows.
|
|
* Then, 4byte bigendian, length of the control frame message.
|
|
* Then, the control frame payload (of that length). with in it:
|
|
* 4byte bigendian, control type (eg. START, STOP, READY, ACCEPT, FINISH).
|
|
* perhaps nothing more (STOP, FINISH), but for other types maybe
|
|
* control fields
|
|
* 4byte bigendian, the control-field-type, currently only content-type.
|
|
* 4byte bigendian, length of the string for this option.
|
|
* .. bytes of that string.
|
|
*
|
|
* The START type can have only one field. Field max len 256.
|
|
* control frame max frame length 512 (excludes the 0-escape and control
|
|
* frame length bytes).
|
|
*
|
|
* the bidirectional type of transmission is like this:
|
|
* client sends READY (with content type included),
|
|
* client waits for ACCEPT (with content type included),
|
|
* client sends START (with matched content type from ACCEPT)
|
|
* .. data frames
|
|
* client sends STOP.
|
|
* client waits for FINISH frame.
|
|
*
|
|
*/
|
|
|
|
/** max length of Frame Streams content type field string */
|
|
#define FSTRM_CONTENT_TYPE_LENGTH_MAX 256
|
|
/** control frame value to denote the control frame ACCEPT */
|
|
#define FSTRM_CONTROL_FRAME_ACCEPT 0x01
|
|
/** control frame value to denote the control frame START */
|
|
#define FSTRM_CONTROL_FRAME_START 0x02
|
|
/** control frame value to denote the control frame STOP */
|
|
#define FSTRM_CONTROL_FRAME_STOP 0x03
|
|
/** control frame value to denote the control frame READY */
|
|
#define FSTRM_CONTROL_FRAME_READY 0x04
|
|
/** control frame value to denote the control frame FINISH */
|
|
#define FSTRM_CONTROL_FRAME_FINISH 0x05
|
|
/** the constant that denotes the control field type that is the
|
|
* string for the content type of the stream. */
|
|
#define FSTRM_CONTROL_FIELD_TYPE_CONTENT_TYPE 0x01
|
|
/** the content type for DNSTAP frame streams */
|
|
#define DNSTAP_CONTENT_TYPE "protobuf:dnstap.Dnstap"
|
|
|
|
/**
|
|
* This creates an FSTRM control frame of type START.
|
|
* @param contenttype: a zero delimited string with the content type.
|
|
* eg. use the constant DNSTAP_CONTENT_TYPE, which is defined as
|
|
* "protobuf:dnstap.Dnstap", for a dnstap frame stream.
|
|
* @param len: if a buffer is returned this is the length of that buffer.
|
|
* @return NULL on malloc failure. Returns a malloced buffer with the
|
|
* protocol message. The buffer starts with the 4 bytes of 0 that indicate
|
|
* a control frame. The buffer should be sent without preceding it with
|
|
* the 'len' variable (like data frames are), but straight the content of the
|
|
* buffer, because the lengths are included in the buffer. This is so that
|
|
* the zero control indicator can be included before the control frame length.
|
|
*/
|
|
void* fstrm_create_control_frame_start(char* contenttype, size_t* len);
|
|
|
|
/**
|
|
* This creates an FSTRM control frame of type READY.
|
|
* @param contenttype: a zero delimited string with the content type.
|
|
* eg. use the constant DNSTAP_CONTENT_TYPE, which is defined as
|
|
* "protobuf:dnstap.Dnstap", for a dnstap frame stream.
|
|
* @param len: if a buffer is returned this is the length of that buffer.
|
|
* @return NULL on malloc failure. Returns a malloced buffer with the
|
|
* protocol message. The buffer starts with the 4 bytes of 0 that indicate
|
|
* a control frame. The buffer should be sent without preceding it with
|
|
* the 'len' variable (like data frames are), but straight the content of the
|
|
* buffer, because the lengths are included in the buffer. This is so that
|
|
* the zero control indicator can be included before the control frame length.
|
|
*/
|
|
void* fstrm_create_control_frame_ready(char* contenttype, size_t* len);
|
|
|
|
/**
|
|
* This creates an FSTRM control frame of type STOP.
|
|
* @param len: if a buffer is returned this is the length of that buffer.
|
|
* @return NULL on malloc failure. Returns a malloced buffer with the
|
|
* protocol message. The buffer starts with the 4 bytes of 0 that indicate
|
|
* a control frame. The buffer should be sent without preceding it with
|
|
* the 'len' variable (like data frames are), but straight the content of the
|
|
* buffer, because the lengths are included in the buffer. This is so that
|
|
* the zero control indicator can be included before the control frame length.
|
|
*/
|
|
void* fstrm_create_control_frame_stop(size_t* len);
|
|
|
|
/**
|
|
* This creates an FSTRM control frame of type ACCEPT.
|
|
* @param contenttype: a zero delimited string with the content type.
|
|
* for dnstap streams use DNSTAP_CONTENT_TYPE.
|
|
* @param len: if a buffer is returned this is the length of that buffer.
|
|
* @return NULL on malloc failure. Returns a malloced buffer with the
|
|
* protocol message. The buffer starts with the 4 bytes of 0 that indicate
|
|
* a control frame. The buffer should be sent without preceding it with
|
|
* the 'len' variable (like data frames are), but straight the content of the
|
|
* buffer, because the lengths are included in the buffer. This is so that
|
|
* the zero control indicator can be included before the control frame length.
|
|
*/
|
|
void* fstrm_create_control_frame_accept(char* contenttype, size_t* len);
|
|
|
|
/**
|
|
* This creates an FSTRM control frame of type FINISH.
|
|
* @param len: if a buffer is returned this is the length of that buffer.
|
|
* @return NULL on malloc failure. Returns a malloced buffer with the
|
|
* protocol message. The buffer starts with the 4 bytes of 0 that indicate
|
|
* a control frame. The buffer should be sent without preceding it with
|
|
* the 'len' variable (like data frames are), but straight the content of the
|
|
* buffer, because the lengths are included in the buffer. This is so that
|
|
* the zero control indicator can be included before the control frame length.
|
|
*/
|
|
void* fstrm_create_control_frame_finish(size_t* len);
|
|
|
|
/**
|
|
* Return string that describes a control packet. For debug, logs.
|
|
* Like 'start content-type(protobuf:dnstap.Dnstap)' or 'stop'.
|
|
* @param pkt: the packet data, that is the data after the 4 zero start
|
|
* bytes and 4 length bytes.
|
|
* @param len: the length of the control packet data, in pkt. This is the
|
|
* ntohl of the 4 bytes length preceding the data.
|
|
* @return zero delimited string, malloced. Or NULL on malloc failure.
|
|
*/
|
|
char* fstrm_describe_control(void* pkt, size_t len);
|
|
|
|
#endif /* DNSTAP_FSTRM_H */
|