view src/http/ngx_http_huff_encode.c @ 9204:631ee3c6d38c

Upstream: fixed usage of closed sockets with filter finalization. When filter finalization is triggered when working with an upstream server, and error_page redirects request processing to some simple handler, ngx_http_request_finalize() triggers request termination when the response is sent. In particular, via the upstream cleanup handler, nginx will close the upstream connection and the corresponding socket. Still, this can happen to be with ngx_event_pipe() on stack. While the code will set p->downstream_error due to NGX_ERROR returned from the output filter chain by filter finalization, otherwise the error will be ignored till control returns to ngx_http_upstream_process_request(). And event pipe might try reading from the (already closed) socket, resulting in "readv() failed (9: Bad file descriptor) while reading upstream" errors (or even segfaults with SSL). Such errors were seen with the following configuration: location /t2 { proxy_pass http://127.0.0.1:8080/big; image_filter_buffer 10m; image_filter resize 150 100; error_page 415 = /empty; } location /empty { return 204; } location /big { # big enough static file } Fix is to clear p->upstream in ngx_http_upstream_finalize_request(), and ensure that p->upstream is checked in ngx_event_pipe_read_upstream() and when handling events at ngx_event_pipe() exit.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 30 Jan 2024 03:20:10 +0300
parents 336084ff943b
children
line wrap: on
line source


/*
 * 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_huff_encode_code_t;


static ngx_http_huff_encode_code_t  ngx_http_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_huff_encode_code_t  ngx_http_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_huff_encode_buf(dst, buf)                                    \
    (*(uint64_t *) (dst) = __builtin_bswap64(buf))
#else
#define ngx_http_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_huff_encode_buf(dst, buf)                                    \
    (*(uint64_t *) (dst) = (buf))
#endif

#else /* NGX_PTR_SIZE == 4 */

#define ngx_http_huff_encode_buf(dst, buf)                                    \
    (*(uint32_t *) (dst) = htonl(buf))

#endif


size_t
ngx_http_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_huff_encode_code_t  *table, *next;

    table = lower ? ngx_http_huff_encode_table_lc
                  : ngx_http_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_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;
}