| /* |
| * include/haproxy/htx-t.h |
| * This file declares the types and constants used the internal HTTP messages |
| * |
| * Copyright (C) 2018 HAProxy Technologies, Christopher Faulet <cfaulet@haproxy.com> |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation, version 2.1 |
| * exclusively. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #ifndef _HAPROXY_HTX_T_H |
| #define _HAPROXY_HTX_T_H |
| |
| #include <haproxy/api.h> |
| #include <haproxy/http-t.h> |
| |
| /* |
| * The internal representation of an HTTP message, called HTX, is a structure |
| * with useful information on the message followed by a contiguous array |
| * containing parts of the message, called blocks. A block is composed of |
| * metadata (htx_blk) and the associated payload. Blocks' metadata are stored |
| * starting from the end of the array while their payload are stored at the |
| * beginning. Blocks' metadata are often simply called blocks. it is a misuse of |
| * language that's simplify explanations. |
| * |
| * |
| * +-----+---------------+------------------------------+--------------+ |
| * | HTX | PAYLOADS ==> | | <== HTX_BLKs | |
| * +-----+---------------+------------------------------+--------------+ |
| * ^ |
| * blocks[] (the beginning of the bocks array) |
| * |
| * |
| * The blocks part remains linear and sorted. You may think about it as an array |
| * with negative indexes. But, instead of using negative indexes, we use |
| * positive positions to identify a block. This position is then converted to a |
| * address relatively to the beginning of the blocks array. |
| * |
| * |
| * .....--+------------------------------+-----+-----+ |
| * | ... | BLK | BLK | |
| * .....--+------------------------------+-----+-----+ |
| * ^ ^ |
| * Addr of the block Addr of the block |
| * at the position 1 at the position 0 |
| * |
| * |
| * The payloads part is a raw space that may wrap. You never access to a block's |
| * payload directly. Instead you get a block to retrieve the address of its |
| * payload. When no more space left between blocks and payloads parts, the free |
| * space at the beginning, if any, is used. |
| * |
| * |
| * +----------- WRAPPING ------------------------+ |
| * | | |
| * V | |
| * +-----+-------------+---------------+---------------++--------------+ |
| * | HTX | PAYLOAD ==> | | PAYLOADS ==X || X== HTX_BLKs | |
| * +-----+-------------+---------------+---------------++--------------+ |
| * |
| * |
| * The blocks part, on its side, never wrap. If we have no space to allocate a |
| * new block and if there is a hole at the beginning of the blocks part (so at |
| * the end of the blocks array), we move back all blocks.x |
| * |
| * |
| * ...+--------------+----------+ blocks ...+----------+--------------+ |
| * | X== HTX_BLKS | | defrag | | <== HTX_BLKS | |
| * ...+--------------+----------+ =====> ...+----------+--------------+ |
| * |
| * |
| * At the end, if payload wrapping or blocks defragmentation is not enough, some |
| * free space may be get back with a full defragmentation. This way, the holes in |
| * the middle are not reusable but count in the available free space. The only |
| * way to reuse this lost space is to fully defragmenate the HTX message. |
| * |
| * - * - |
| * |
| * An HTX block is as well a header as a body part or a trailer. For all these |
| * types of block, a payload is attached to the block. It can also be a mark, |
| * like the end-of-headers or end-of-trailers. For these blocks, there is no |
| * payload but it count for a byte. It is important to not skip it when data are |
| * forwarded. Metadata of an HTX block are composed of 2 fields : |
| * |
| * - .info : It a 32 bits field containing the block's type on 4 bits |
| * followed by the payload length. See below for details. |
| * |
| * - .addr : The payload's address, if any, relatively to the beginning the |
| * array used to store the HTX message itself. |
| * |
| * htx_blk.info representation : |
| * |
| * 0b 0000 0000 0000 0000 0000 0000 0000 0000 |
| * ---- ------------------------ --------- |
| * type value (1 MB max) name length (header/trailer) |
| * ---------------------------------- |
| * data length (256 MB max) |
| * (body, method, path, version, status, reason) |
| * |
| * types : |
| * - 0000 = request start-line |
| * - 0001 = response start-line |
| * - 0010 = header |
| * - 0011 = pseudo-header ou "special" header |
| * - 0100 = end-of-headers |
| * - 0101 = data |
| * - 0110 = trailer |
| * - 0111 = end-of-trailers |
| * ... |
| * - 1111 = unused |
| * |
| */ |
| |
| /* HTX start-line flags */ |
| #define HTX_SL_F_NONE 0x00000000 |
| #define HTX_SL_F_IS_RESP 0x00000001 /* It is the response start-line (unset means the request one) */ |
| #define HTX_SL_F_XFER_LEN 0x00000002 /* The message xfer size can be dertermined */ |
| #define HTX_SL_F_XFER_ENC 0x00000004 /* The transfer-encoding header was found in message */ |
| #define HTX_SL_F_CLEN 0x00000008 /* The content-length header was found in message */ |
| #define HTX_SL_F_CHNK 0x00000010 /* The message payload is chunked */ |
| #define HTX_SL_F_VER_11 0x00000020 /* The message indicates version 1.1 or above */ |
| #define HTX_SL_F_BODYLESS 0x00000040 /* The message has no body (content-length = 0) */ |
| #define HTX_SL_F_HAS_SCHM 0x00000080 /* The scheme is explicitly specified */ |
| #define HTX_SL_F_SCHM_HTTP 0x00000100 /* The scheme HTTP should be used */ |
| #define HTX_SL_F_SCHM_HTTPS 0x00000200 /* The scheme HTTPS should be used */ |
| #define HTX_SL_F_HAS_AUTHORITY 0x00000400 /* The request authority is explicitly specified */ |
| #define HTX_SL_F_NORMALIZED_URI 0x00000800 /* The received URI is normalized (an implicit absolute-uri form) */ |
| #define HTX_SL_F_CONN_UPG 0x00001000 /* The message contains "connection: upgrade" header */ |
| |
| /* HTX flags */ |
| #define HTX_FL_NONE 0x00000000 |
| #define HTX_FL_PARSING_ERROR 0x00000001 /* Set when a parsing error occurred */ |
| #define HTX_FL_PROCESSING_ERROR 0x00000002 /* Set when a processing error occurred */ |
| #define HTX_FL_FRAGMENTED 0x00000004 /* Set when the HTX buffer is fragmented */ |
| #define HTX_FL_PROXY_RESP 0x00000008 /* Set when the response was generated by HAProxy */ |
| #define HTX_FL_EOM 0x00000010 /* Set when end-of-message is reached from the HTTP point of view |
| * (at worst, on the EOM block is missing) |
| */ |
| |
| /* HTX block's type (max 15). */ |
| enum htx_blk_type { |
| HTX_BLK_REQ_SL = 0, /* Request start-line */ |
| HTX_BLK_RES_SL = 1, /* Response start-line */ |
| HTX_BLK_HDR = 2, /* header name/value block */ |
| HTX_BLK_EOH = 3, /* end-of-headers block */ |
| HTX_BLK_DATA = 4, /* data block */ |
| HTX_BLK_TLR = 5, /* trailer name/value block */ |
| HTX_BLK_EOT = 6, /* end-of-trailers block */ |
| /* 7 .. 14 unused */ |
| HTX_BLK_UNUSED = 15, /* unused/removed block */ |
| }; |
| |
| /* One HTX block descriptor */ |
| struct htx_blk { |
| uint32_t addr; /* relative storage address of the block's payload */ |
| uint32_t info; /* information about the block (type, length) */ |
| }; |
| |
| /* Composite return value used by some HTX functions */ |
| struct htx_ret { |
| int32_t ret; /* A numerical value */ |
| struct htx_blk *blk; /* An HTX block */ |
| }; |
| |
| /* HTX start-line */ |
| struct htx_sl { |
| unsigned int flags; /* HTX_SL_F_* */ |
| union { |
| struct { |
| enum http_meth_t meth; /* method */ |
| } req; |
| struct { |
| uint16_t status; /* status code */ |
| } res; |
| } info; |
| |
| /* XXX 2 bytes unused */ |
| |
| unsigned int len[3]; /* length of different parts of the start-line */ |
| char l[VAR_ARRAY]; |
| }; |
| |
| /* Internal representation of an HTTP message */ |
| struct htx { |
| uint32_t size; /* the array size, in bytes, used to store the HTTP message itself */ |
| uint32_t data; /* the data size, in bytes. To known to total size used by all allocated |
| * blocks (blocks and their contents), you need to add size used by blocks, |
| * i.e. [ used * sizeof(struct htx_blk *) ] */ |
| |
| int32_t tail; /* newest inserted block. -1 if the HTX message is empty */ |
| int32_t head; /* oldest inserted block. -1 if the HTX message is empty */ |
| int32_t first; /* position of the first block to (re)start the analyse. -1 if unset. */ |
| |
| uint32_t tail_addr; /* start address of the free space in front of the the blocks table */ |
| uint32_t head_addr; /* start address of the free space at the beginning */ |
| uint32_t end_addr; /* end address of the free space at the beginning */ |
| |
| uint64_t extra; /* known bytes amount remaining to receive */ |
| uint32_t flags; /* HTX_FL_* */ |
| |
| /* XXX 4 bytes unused */ |
| |
| /* Blocks representing the HTTP message itself */ |
| char blocks[VAR_ARRAY] __attribute__((aligned(8))); |
| }; |
| |
| #endif /* _HAPROXY_HTX_T_H */ |
| |
| /* |
| * Local variables: |
| * c-indent-level: 8 |
| * c-basic-offset: 8 |
| * End: |
| */ |