HTTP/3: generate more H3_FRAME_UNEXPECTED. As per quic-http-34, these are the cases when this error should be generated: If an endpoint receives a second SETTINGS frame on the control stream, the endpoint MUST respond with a connection error of type H3_FRAME_UNEXPECTED SETTINGS frames MUST NOT be sent on any stream other than the control stream. If an endpoint receives a SETTINGS frame on a different stream, the endpoint MUST respond with a connection error of type H3_FRAME_UNEXPECTED. A client MUST NOT send a PUSH_PROMISE frame. A server MUST treat the receipt of a PUSH_PROMISE frame as a connection error of type H3_FRAME_UNEXPECTED; see Section 8. The MAX_PUSH_ID frame is always sent on the control stream. Receipt of a MAX_PUSH_ID frame on any other stream MUST be treated as a connection error of type H3_FRAME_UNEXPECTED. Receipt of an invalid sequence of frames MUST be treated as a connection error of type H3_FRAME_UNEXPECTED; see Section 8. In particular, a DATA frame before any HEADERS frame, or a HEADERS or DATA frame after the trailing HEADERS frame, is considered invalid. A CANCEL_PUSH frame is sent on the control stream. Receiving a CANCEL_PUSH frame on a stream other than the control stream MUST be treated as a connection error of type H3_FRAME_UNEXPECTED. The GOAWAY frame is always sent on the control stream.

/*
 * 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_ */