Mercurial > hg > nginx
view src/core/ngx_murmurhash.c @ 7386:9200b41db765 stable-1.14
HTTP/2: limit the number of idle state switches.
An attack that continuously switches HTTP/2 connection between
idle and active states can result in excessive CPU usage.
This is because when a connection switches to the idle state,
all of its memory pool caches are freed.
This change limits the maximum allowed number of idle state
switches to 10 * http2_max_requests (i.e., 10000 by default).
This limits possible CPU usage in one connection, and also
imposes a limit on the maximum lifetime of a connection.
Initially reported by Gal Goldshtein from F5 Networks.
author | Ruslan Ermilov <ru@nginx.com> |
---|---|
date | Tue, 06 Nov 2018 16:29:49 +0300 |
parents | f38647c651a8 |
children |
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/* * Copyright (C) Austin Appleby */ #include <ngx_config.h> #include <ngx_core.h> uint32_t ngx_murmur_hash2(u_char *data, size_t len) { uint32_t h, k; h = 0 ^ len; while (len >= 4) { k = data[0]; k |= data[1] << 8; k |= data[2] << 16; k |= data[3] << 24; k *= 0x5bd1e995; k ^= k >> 24; k *= 0x5bd1e995; h *= 0x5bd1e995; h ^= k; data += 4; len -= 4; } switch (len) { case 3: h ^= data[2] << 16; /* fall through */ case 2: h ^= data[1] << 8; /* fall through */ case 1: h ^= data[0]; h *= 0x5bd1e995; } h ^= h >> 13; h *= 0x5bd1e995; h ^= h >> 15; return h; }