gRPC: RST_STREAM(NO_ERROR) handling after "trailer only" responses. Similarly to the problem fixed in 2096b21fcd10 (ticket #1792), when a "trailer only" gRPC response (that is, a response with the END_STREAM flag in the HEADERS frame) was immediately followed by RST_STREAM(NO_ERROR) in the data preread along with the response header, RST_STREAM wasn't properly skipped and caused "upstream rejected request with error 0" errors. Observed with "unknown service" gRPC errors returned by grpc-go. Fix is to set ctx->done if we are going to parse additional data, so the RST_STREAM(NO_ERROR) is properly skipped. Additionally, now ngx_http_grpc_filter() will complain about frames sent for closed stream if there are any.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


int ngx_file_type(char *file, ngx_file_info_t *sb)
{
    sb->dwFileAttributes = GetFileAttributes(file);

    if (sb->dwFileAttributes == INVALID_FILE_ATTRIBUTES) {
        return -1;
    }

    return 0;
}

/*
int ngx_stat(char *file, ngx_stat_t *sb)
{
    *sb = GetFileAttributes(file);

    if (*sb == INVALID_FILE_ATTRIBUTES) {
        return -1;
    }

    return 0;
}
*/