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view src/core/ngx_crc32.h @ 9179:ea1f29c2010c
HTTP/2: fixed buffer management with HTTP/2 auto-detection.
As part of normal HTTP/2 processing, incomplete frames are saved in the
control state using a fixed size memcpy of NGX_HTTP_V2_STATE_BUFFER_SIZE.
For this matter, two state buffers are reserved in the HTTP/2 recv buffer.
As part of HTTP/2 auto-detection on plain TCP connections, initial data
is first read into a buffer specified by the client_header_buffer_size
directive that doesn't have state reservation. Previously, this made it
possible to over-read the buffer as part of saving the state.
The fix is to read the available buffer size rather than a fixed size.
Although memcpy of a fixed size can produce a better optimized code,
handling of incomplete frames isn't a common execution path, so it was
sacrificed for the sake of simplicity of the fix.
author | Sergey Kandaurov <pluknet@nginx.com> |
---|---|
date | Sat, 21 Oct 2023 18:48:24 +0400 |
parents | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_CRC32_H_INCLUDED_ #define _NGX_CRC32_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> extern uint32_t *ngx_crc32_table_short; extern uint32_t ngx_crc32_table256[]; static ngx_inline uint32_t ngx_crc32_short(u_char *p, size_t len) { u_char c; uint32_t crc; crc = 0xffffffff; while (len--) { c = *p++; crc = ngx_crc32_table_short[(crc ^ (c & 0xf)) & 0xf] ^ (crc >> 4); crc = ngx_crc32_table_short[(crc ^ (c >> 4)) & 0xf] ^ (crc >> 4); } return crc ^ 0xffffffff; } static ngx_inline uint32_t ngx_crc32_long(u_char *p, size_t len) { uint32_t crc; crc = 0xffffffff; while (len--) { crc = ngx_crc32_table256[(crc ^ *p++) & 0xff] ^ (crc >> 8); } return crc ^ 0xffffffff; } #define ngx_crc32_init(crc) \ crc = 0xffffffff static ngx_inline void ngx_crc32_update(uint32_t *crc, u_char *p, size_t len) { uint32_t c; c = *crc; while (len--) { c = ngx_crc32_table256[(c ^ *p++) & 0xff] ^ (c >> 8); } *crc = c; } #define ngx_crc32_final(crc) \ crc ^= 0xffffffff ngx_int_t ngx_crc32_table_init(void); #endif /* _NGX_CRC32_H_INCLUDED_ */