Mercurial > hg > nginx
view src/http/v2/ngx_http_v2_huff_encode.c @ 7975:a7a77549265e
HTTP/2: fixed sendfile() aio handling.
With sendfile() in threads ("aio threads; sendfile on;"), client connection
can block on writing, waiting for sendfile() to complete. In HTTP/2 this
might result in the request hang, since an attempt to continue processing
in thread event handler will call request's write event handler, which
is usually stopped by ngx_http_v2_send_chain(): it does nothing if there
are no additional data and stream->queued is set. Further, HTTP/2 resets
stream's c->write->ready to 0 if writing blocks, so just fixing
ngx_http_v2_send_chain() is not enough.
Can be reproduced with test suite on Linux with:
TEST_NGINX_GLOBALS_HTTP="aio threads; sendfile on;" prove h2*.t
The following tests currently fail: h2_keepalive.t, h2_priority.t,
h2_proxy_max_temp_file_size.t, h2.t, h2_trailers.t.
Similarly, sendfile() with AIO preloading on FreeBSD can block as well,
with similar results. This is, however, harder to reproduce, especially
on modern FreeBSD systems, since sendfile() usually does not return EBUSY.
Fix is to modify ngx_http_v2_send_chain() so it actually tries to send
data to the main connection when called, and to make sure that
c->write->ready is set by the relevant event handlers.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 25 Nov 2021 22:02:10 +0300 |
parents | dcfe355dfda4 |
children |
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/* * Copyright (C) Nginx, Inc. * Copyright (C) Valentin V. Bartenev * Copyright (C) 2015 Vlad Krasnov */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { uint32_t code; uint32_t len; } ngx_http_v2_huff_encode_code_t; static ngx_http_v2_huff_encode_code_t ngx_http_v2_huff_encode_table[256] = { {0x00001ff8, 13}, {0x007fffd8, 23}, {0x0fffffe2, 28}, {0x0fffffe3, 28}, {0x0fffffe4, 28}, {0x0fffffe5, 28}, {0x0fffffe6, 28}, {0x0fffffe7, 28}, {0x0fffffe8, 28}, {0x00ffffea, 24}, {0x3ffffffc, 30}, {0x0fffffe9, 28}, {0x0fffffea, 28}, {0x3ffffffd, 30}, {0x0fffffeb, 28}, {0x0fffffec, 28}, {0x0fffffed, 28}, {0x0fffffee, 28}, {0x0fffffef, 28}, {0x0ffffff0, 28}, {0x0ffffff1, 28}, {0x0ffffff2, 28}, {0x3ffffffe, 30}, {0x0ffffff3, 28}, {0x0ffffff4, 28}, {0x0ffffff5, 28}, {0x0ffffff6, 28}, {0x0ffffff7, 28}, {0x0ffffff8, 28}, {0x0ffffff9, 28}, {0x0ffffffa, 28}, {0x0ffffffb, 28}, {0x00000014, 6}, {0x000003f8, 10}, {0x000003f9, 10}, {0x00000ffa, 12}, {0x00001ff9, 13}, {0x00000015, 6}, {0x000000f8, 8}, {0x000007fa, 11}, {0x000003fa, 10}, {0x000003fb, 10}, {0x000000f9, 8}, {0x000007fb, 11}, {0x000000fa, 8}, {0x00000016, 6}, {0x00000017, 6}, {0x00000018, 6}, {0x00000000, 5}, {0x00000001, 5}, {0x00000002, 5}, {0x00000019, 6}, {0x0000001a, 6}, {0x0000001b, 6}, {0x0000001c, 6}, {0x0000001d, 6}, {0x0000001e, 6}, {0x0000001f, 6}, {0x0000005c, 7}, {0x000000fb, 8}, {0x00007ffc, 15}, {0x00000020, 6}, {0x00000ffb, 12}, {0x000003fc, 10}, {0x00001ffa, 13}, {0x00000021, 6}, {0x0000005d, 7}, {0x0000005e, 7}, {0x0000005f, 7}, {0x00000060, 7}, {0x00000061, 7}, {0x00000062, 7}, {0x00000063, 7}, {0x00000064, 7}, {0x00000065, 7}, {0x00000066, 7}, {0x00000067, 7}, {0x00000068, 7}, {0x00000069, 7}, {0x0000006a, 7}, {0x0000006b, 7}, {0x0000006c, 7}, {0x0000006d, 7}, {0x0000006e, 7}, {0x0000006f, 7}, {0x00000070, 7}, {0x00000071, 7}, {0x00000072, 7}, {0x000000fc, 8}, {0x00000073, 7}, {0x000000fd, 8}, {0x00001ffb, 13}, {0x0007fff0, 19}, {0x00001ffc, 13}, {0x00003ffc, 14}, {0x00000022, 6}, {0x00007ffd, 15}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00007ffe, 15}, {0x000007fc, 11}, {0x00003ffd, 14}, {0x00001ffd, 13}, {0x0ffffffc, 28}, {0x000fffe6, 20}, {0x003fffd2, 22}, {0x000fffe7, 20}, {0x000fffe8, 20}, {0x003fffd3, 22}, {0x003fffd4, 22}, {0x003fffd5, 22}, {0x007fffd9, 23}, {0x003fffd6, 22}, {0x007fffda, 23}, {0x007fffdb, 23}, {0x007fffdc, 23}, {0x007fffdd, 23}, {0x007fffde, 23}, {0x00ffffeb, 24}, {0x007fffdf, 23}, {0x00ffffec, 24}, {0x00ffffed, 24}, {0x003fffd7, 22}, {0x007fffe0, 23}, {0x00ffffee, 24}, {0x007fffe1, 23}, {0x007fffe2, 23}, {0x007fffe3, 23}, {0x007fffe4, 23}, {0x001fffdc, 21}, {0x003fffd8, 22}, {0x007fffe5, 23}, {0x003fffd9, 22}, {0x007fffe6, 23}, {0x007fffe7, 23}, {0x00ffffef, 24}, {0x003fffda, 22}, {0x001fffdd, 21}, {0x000fffe9, 20}, {0x003fffdb, 22}, {0x003fffdc, 22}, {0x007fffe8, 23}, {0x007fffe9, 23}, {0x001fffde, 21}, {0x007fffea, 23}, {0x003fffdd, 22}, {0x003fffde, 22}, {0x00fffff0, 24}, {0x001fffdf, 21}, {0x003fffdf, 22}, {0x007fffeb, 23}, {0x007fffec, 23}, {0x001fffe0, 21}, {0x001fffe1, 21}, {0x003fffe0, 22}, {0x001fffe2, 21}, {0x007fffed, 23}, {0x003fffe1, 22}, {0x007fffee, 23}, {0x007fffef, 23}, {0x000fffea, 20}, {0x003fffe2, 22}, {0x003fffe3, 22}, {0x003fffe4, 22}, {0x007ffff0, 23}, {0x003fffe5, 22}, {0x003fffe6, 22}, {0x007ffff1, 23}, {0x03ffffe0, 26}, {0x03ffffe1, 26}, {0x000fffeb, 20}, {0x0007fff1, 19}, {0x003fffe7, 22}, {0x007ffff2, 23}, {0x003fffe8, 22}, {0x01ffffec, 25}, {0x03ffffe2, 26}, {0x03ffffe3, 26}, {0x03ffffe4, 26}, {0x07ffffde, 27}, {0x07ffffdf, 27}, {0x03ffffe5, 26}, {0x00fffff1, 24}, {0x01ffffed, 25}, {0x0007fff2, 19}, {0x001fffe3, 21}, {0x03ffffe6, 26}, {0x07ffffe0, 27}, {0x07ffffe1, 27}, {0x03ffffe7, 26}, {0x07ffffe2, 27}, {0x00fffff2, 24}, {0x001fffe4, 21}, {0x001fffe5, 21}, {0x03ffffe8, 26}, {0x03ffffe9, 26}, {0x0ffffffd, 28}, {0x07ffffe3, 27}, {0x07ffffe4, 27}, {0x07ffffe5, 27}, {0x000fffec, 20}, {0x00fffff3, 24}, {0x000fffed, 20}, {0x001fffe6, 21}, {0x003fffe9, 22}, {0x001fffe7, 21}, {0x001fffe8, 21}, {0x007ffff3, 23}, {0x003fffea, 22}, {0x003fffeb, 22}, {0x01ffffee, 25}, {0x01ffffef, 25}, {0x00fffff4, 24}, {0x00fffff5, 24}, {0x03ffffea, 26}, {0x007ffff4, 23}, {0x03ffffeb, 26}, {0x07ffffe6, 27}, {0x03ffffec, 26}, {0x03ffffed, 26}, {0x07ffffe7, 27}, {0x07ffffe8, 27}, {0x07ffffe9, 27}, {0x07ffffea, 27}, {0x07ffffeb, 27}, {0x0ffffffe, 28}, {0x07ffffec, 27}, {0x07ffffed, 27}, {0x07ffffee, 27}, {0x07ffffef, 27}, {0x07fffff0, 27}, {0x03ffffee, 26} }; /* same as above, but embeds lowercase transformation */ static ngx_http_v2_huff_encode_code_t ngx_http_v2_huff_encode_table_lc[256] = { {0x00001ff8, 13}, {0x007fffd8, 23}, {0x0fffffe2, 28}, {0x0fffffe3, 28}, {0x0fffffe4, 28}, {0x0fffffe5, 28}, {0x0fffffe6, 28}, {0x0fffffe7, 28}, {0x0fffffe8, 28}, {0x00ffffea, 24}, {0x3ffffffc, 30}, {0x0fffffe9, 28}, {0x0fffffea, 28}, {0x3ffffffd, 30}, {0x0fffffeb, 28}, {0x0fffffec, 28}, {0x0fffffed, 28}, {0x0fffffee, 28}, {0x0fffffef, 28}, {0x0ffffff0, 28}, {0x0ffffff1, 28}, {0x0ffffff2, 28}, {0x3ffffffe, 30}, {0x0ffffff3, 28}, {0x0ffffff4, 28}, {0x0ffffff5, 28}, {0x0ffffff6, 28}, {0x0ffffff7, 28}, {0x0ffffff8, 28}, {0x0ffffff9, 28}, {0x0ffffffa, 28}, {0x0ffffffb, 28}, {0x00000014, 6}, {0x000003f8, 10}, {0x000003f9, 10}, {0x00000ffa, 12}, {0x00001ff9, 13}, {0x00000015, 6}, {0x000000f8, 8}, {0x000007fa, 11}, {0x000003fa, 10}, {0x000003fb, 10}, {0x000000f9, 8}, {0x000007fb, 11}, {0x000000fa, 8}, {0x00000016, 6}, {0x00000017, 6}, {0x00000018, 6}, {0x00000000, 5}, {0x00000001, 5}, {0x00000002, 5}, {0x00000019, 6}, {0x0000001a, 6}, {0x0000001b, 6}, {0x0000001c, 6}, {0x0000001d, 6}, {0x0000001e, 6}, {0x0000001f, 6}, {0x0000005c, 7}, {0x000000fb, 8}, {0x00007ffc, 15}, {0x00000020, 6}, {0x00000ffb, 12}, {0x000003fc, 10}, {0x00001ffa, 13}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00001ffb, 13}, {0x0007fff0, 19}, {0x00001ffc, 13}, {0x00003ffc, 14}, {0x00000022, 6}, {0x00007ffd, 15}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00007ffe, 15}, {0x000007fc, 11}, {0x00003ffd, 14}, {0x00001ffd, 13}, {0x0ffffffc, 28}, {0x000fffe6, 20}, {0x003fffd2, 22}, {0x000fffe7, 20}, {0x000fffe8, 20}, {0x003fffd3, 22}, {0x003fffd4, 22}, {0x003fffd5, 22}, {0x007fffd9, 23}, {0x003fffd6, 22}, {0x007fffda, 23}, {0x007fffdb, 23}, {0x007fffdc, 23}, {0x007fffdd, 23}, {0x007fffde, 23}, {0x00ffffeb, 24}, {0x007fffdf, 23}, {0x00ffffec, 24}, {0x00ffffed, 24}, {0x003fffd7, 22}, {0x007fffe0, 23}, {0x00ffffee, 24}, {0x007fffe1, 23}, {0x007fffe2, 23}, {0x007fffe3, 23}, {0x007fffe4, 23}, {0x001fffdc, 21}, {0x003fffd8, 22}, {0x007fffe5, 23}, {0x003fffd9, 22}, {0x007fffe6, 23}, {0x007fffe7, 23}, {0x00ffffef, 24}, {0x003fffda, 22}, {0x001fffdd, 21}, {0x000fffe9, 20}, {0x003fffdb, 22}, {0x003fffdc, 22}, {0x007fffe8, 23}, {0x007fffe9, 23}, {0x001fffde, 21}, {0x007fffea, 23}, {0x003fffdd, 22}, {0x003fffde, 22}, {0x00fffff0, 24}, {0x001fffdf, 21}, {0x003fffdf, 22}, {0x007fffeb, 23}, {0x007fffec, 23}, {0x001fffe0, 21}, {0x001fffe1, 21}, {0x003fffe0, 22}, {0x001fffe2, 21}, {0x007fffed, 23}, {0x003fffe1, 22}, {0x007fffee, 23}, {0x007fffef, 23}, {0x000fffea, 20}, {0x003fffe2, 22}, {0x003fffe3, 22}, {0x003fffe4, 22}, {0x007ffff0, 23}, {0x003fffe5, 22}, {0x003fffe6, 22}, {0x007ffff1, 23}, {0x03ffffe0, 26}, {0x03ffffe1, 26}, {0x000fffeb, 20}, {0x0007fff1, 19}, {0x003fffe7, 22}, {0x007ffff2, 23}, {0x003fffe8, 22}, {0x01ffffec, 25}, {0x03ffffe2, 26}, {0x03ffffe3, 26}, {0x03ffffe4, 26}, {0x07ffffde, 27}, {0x07ffffdf, 27}, {0x03ffffe5, 26}, {0x00fffff1, 24}, {0x01ffffed, 25}, {0x0007fff2, 19}, {0x001fffe3, 21}, {0x03ffffe6, 26}, {0x07ffffe0, 27}, {0x07ffffe1, 27}, {0x03ffffe7, 26}, {0x07ffffe2, 27}, {0x00fffff2, 24}, {0x001fffe4, 21}, {0x001fffe5, 21}, {0x03ffffe8, 26}, {0x03ffffe9, 26}, {0x0ffffffd, 28}, {0x07ffffe3, 27}, {0x07ffffe4, 27}, {0x07ffffe5, 27}, {0x000fffec, 20}, {0x00fffff3, 24}, {0x000fffed, 20}, {0x001fffe6, 21}, {0x003fffe9, 22}, {0x001fffe7, 21}, {0x001fffe8, 21}, {0x007ffff3, 23}, {0x003fffea, 22}, {0x003fffeb, 22}, {0x01ffffee, 25}, {0x01ffffef, 25}, {0x00fffff4, 24}, {0x00fffff5, 24}, {0x03ffffea, 26}, {0x007ffff4, 23}, {0x03ffffeb, 26}, {0x07ffffe6, 27}, {0x03ffffec, 26}, {0x03ffffed, 26}, {0x07ffffe7, 27}, {0x07ffffe8, 27}, {0x07ffffe9, 27}, {0x07ffffea, 27}, {0x07ffffeb, 27}, {0x0ffffffe, 28}, {0x07ffffec, 27}, {0x07ffffed, 27}, {0x07ffffee, 27}, {0x07ffffef, 27}, {0x07fffff0, 27}, {0x03ffffee, 26} }; #if (NGX_PTR_SIZE == 8) #if (NGX_HAVE_LITTLE_ENDIAN) #if (NGX_HAVE_GCC_BSWAP64) #define ngx_http_v2_huff_encode_buf(dst, buf) \ (*(uint64_t *) (dst) = __builtin_bswap64(buf)) #else #define ngx_http_v2_huff_encode_buf(dst, buf) \ ((dst)[0] = (u_char) ((buf) >> 56), \ (dst)[1] = (u_char) ((buf) >> 48), \ (dst)[2] = (u_char) ((buf) >> 40), \ (dst)[3] = (u_char) ((buf) >> 32), \ (dst)[4] = (u_char) ((buf) >> 24), \ (dst)[5] = (u_char) ((buf) >> 16), \ (dst)[6] = (u_char) ((buf) >> 8), \ (dst)[7] = (u_char) (buf)) #endif #else /* !NGX_HAVE_LITTLE_ENDIAN */ #define ngx_http_v2_huff_encode_buf(dst, buf) \ (*(uint64_t *) (dst) = (buf)) #endif #else /* NGX_PTR_SIZE == 4 */ #define ngx_http_v2_huff_encode_buf(dst, buf) \ (*(uint32_t *) (dst) = htonl(buf)) #endif size_t ngx_http_v2_huff_encode(u_char *src, size_t len, u_char *dst, ngx_uint_t lower) { u_char *end; size_t hlen; ngx_uint_t buf, pending, code; ngx_http_v2_huff_encode_code_t *table, *next; table = lower ? ngx_http_v2_huff_encode_table_lc : ngx_http_v2_huff_encode_table; hlen = 0; buf = 0; pending = 0; end = src + len; while (src != end) { next = &table[*src++]; code = next->code; pending += next->len; /* accumulate bits */ if (pending < sizeof(buf) * 8) { buf |= code << (sizeof(buf) * 8 - pending); continue; } if (hlen + sizeof(buf) >= len) { return 0; } pending -= sizeof(buf) * 8; buf |= code >> pending; ngx_http_v2_huff_encode_buf(&dst[hlen], buf); hlen += sizeof(buf); buf = pending ? code << (sizeof(buf) * 8 - pending) : 0; } if (pending == 0) { return hlen; } buf |= (ngx_uint_t) -1 >> pending; pending = ngx_align(pending, 8); if (hlen + pending / 8 >= len) { return 0; } buf >>= sizeof(buf) * 8 - pending; do { pending -= 8; dst[hlen++] = (u_char) (buf >> pending); } while (pending); return hlen; }