view src/http/modules/ngx_http_ssi_filter_module.h @ 7235:c2a0a838c40f

gRPC: special handling of "trailer only" responses. The gRPC protocol makes a distinction between HEADERS frame with the END_STREAM flag set, and a HEADERS frame followed by an empty DATA frame with the END_STREAM flag. The latter is not permitted, and results in errors not being propagated through nginx. Instead, gRPC clients complain that "server closed the stream without sending trailers" (seen in grpc-go) or "13: Received RST_STREAM with error code 2" (seen in grpc-c). To fix this, nginx now returns HEADERS with the END_STREAM flag if the response length is known to be 0, and we are not expecting any trailer headers to be added. And the response length is explicitly set to 0 in the gRPC proxy if we see initial HEADERS frame with the END_STREAM flag set.
author Maxim Dounin <mdounin@mdounin.ru>
date Sat, 17 Mar 2018 23:04:26 +0300
parents d620f497c50f
children 49e7db44b57c
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_HTTP_SSI_FILTER_H_INCLUDED_
#define _NGX_HTTP_SSI_FILTER_H_INCLUDED_


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


#define NGX_HTTP_SSI_MAX_PARAMS       16

#define NGX_HTTP_SSI_COMMAND_LEN      32
#define NGX_HTTP_SSI_PARAM_LEN        32
#define NGX_HTTP_SSI_PARAMS_N         4


#define NGX_HTTP_SSI_COND_IF          1
#define NGX_HTTP_SSI_COND_ELSE        2


#define NGX_HTTP_SSI_NO_ENCODING      0
#define NGX_HTTP_SSI_URL_ENCODING     1
#define NGX_HTTP_SSI_ENTITY_ENCODING  2


typedef struct {
    ngx_hash_t                hash;
    ngx_hash_keys_arrays_t    commands;
} ngx_http_ssi_main_conf_t;


typedef struct {
    ngx_buf_t                *buf;

    u_char                   *pos;
    u_char                   *copy_start;
    u_char                   *copy_end;

    ngx_uint_t                key;
    ngx_str_t                 command;
    ngx_array_t               params;
    ngx_table_elt_t          *param;
    ngx_table_elt_t           params_array[NGX_HTTP_SSI_PARAMS_N];

    ngx_chain_t              *in;
    ngx_chain_t              *out;
    ngx_chain_t             **last_out;
    ngx_chain_t              *busy;
    ngx_chain_t              *free;

    ngx_uint_t                state;
    ngx_uint_t                saved_state;
    size_t                    saved;
    size_t                    looked;

    size_t                    value_len;

    ngx_list_t               *variables;
    ngx_array_t              *blocks;

#if (NGX_PCRE)
    ngx_uint_t                ncaptures;
    int                      *captures;
    u_char                   *captures_data;
#endif

    unsigned                  conditional:2;
    unsigned                  encoding:2;
    unsigned                  block:1;
    unsigned                  output:1;
    unsigned                  output_chosen:1;

    ngx_http_request_t       *wait;
    void                     *value_buf;
    ngx_str_t                 timefmt;
    ngx_str_t                 errmsg;
} ngx_http_ssi_ctx_t;


typedef ngx_int_t (*ngx_http_ssi_command_pt) (ngx_http_request_t *r,
    ngx_http_ssi_ctx_t *ctx, ngx_str_t **);


typedef struct {
    ngx_str_t                 name;
    ngx_uint_t                index;

    unsigned                  mandatory:1;
    unsigned                  multiple:1;
} ngx_http_ssi_param_t;


typedef struct {
    ngx_str_t                 name;
    ngx_http_ssi_command_pt   handler;
    ngx_http_ssi_param_t     *params;

    unsigned                  conditional:2;
    unsigned                  block:1;
    unsigned                  flush:1;
} ngx_http_ssi_command_t;


extern ngx_module_t  ngx_http_ssi_filter_module;


#endif /* _NGX_HTTP_SSI_FILTER_H_INCLUDED_ */