view src/http/modules/ngx_http_addition_filter_module.c @ 6963:3ff293cfdab8

Slice filter: prevented slice redirection (ticket #1219). When a slice subrequest was redirected to a new location, its context was lost. After its completion, a new slice subrequest for the same slice was created. This could lead to infinite loop. Now the slice module makes sure each slice subrequest starts output with the slice context available.
author Roman Arutyunyan <arut@nginx.com>
date Fri, 31 Mar 2017 21:47:56 +0300
parents ebba2f980489
children f583559aadc7
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


typedef struct {
    ngx_str_t     before_body;
    ngx_str_t     after_body;

    ngx_hash_t    types;
    ngx_array_t  *types_keys;
} ngx_http_addition_conf_t;


typedef struct {
    ngx_uint_t    before_body_sent;
} ngx_http_addition_ctx_t;


static void *ngx_http_addition_create_conf(ngx_conf_t *cf);
static char *ngx_http_addition_merge_conf(ngx_conf_t *cf, void *parent,
    void *child);
static ngx_int_t ngx_http_addition_filter_init(ngx_conf_t *cf);


static ngx_command_t  ngx_http_addition_commands[] = {

    { ngx_string("add_before_body"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_addition_conf_t, before_body),
      NULL },

    { ngx_string("add_after_body"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_addition_conf_t, after_body),
      NULL },

    { ngx_string("addition_types"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
      ngx_http_types_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_addition_conf_t, types_keys),
      &ngx_http_html_default_types[0] },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_addition_filter_module_ctx = {
    NULL,                                  /* preconfiguration */
    ngx_http_addition_filter_init,         /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    NULL,                                  /* create server configuration */
    NULL,                                  /* merge server configuration */

    ngx_http_addition_create_conf,         /* create location configuration */
    ngx_http_addition_merge_conf           /* merge location configuration */
};


ngx_module_t  ngx_http_addition_filter_module = {
    NGX_MODULE_V1,
    &ngx_http_addition_filter_module_ctx,  /* module context */
    ngx_http_addition_commands,            /* module directives */
    NGX_HTTP_MODULE,                       /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_http_output_header_filter_pt  ngx_http_next_header_filter;
static ngx_http_output_body_filter_pt    ngx_http_next_body_filter;


static ngx_int_t
ngx_http_addition_header_filter(ngx_http_request_t *r)
{
    ngx_http_addition_ctx_t   *ctx;
    ngx_http_addition_conf_t  *conf;

    if (r->headers_out.status != NGX_HTTP_OK || r != r->main) {
        return ngx_http_next_header_filter(r);
    }

    conf = ngx_http_get_module_loc_conf(r, ngx_http_addition_filter_module);

    if (conf->before_body.len == 0 && conf->after_body.len == 0) {
        return ngx_http_next_header_filter(r);
    }

    if (ngx_http_test_content_type(r, &conf->types) == NULL) {
        return ngx_http_next_header_filter(r);
    }

    ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_addition_ctx_t));
    if (ctx == NULL) {
        return NGX_ERROR;
    }

    ngx_http_set_ctx(r, ctx, ngx_http_addition_filter_module);

    ngx_http_clear_content_length(r);
    ngx_http_clear_accept_ranges(r);
    ngx_http_weak_etag(r);

    return ngx_http_next_header_filter(r);
}


static ngx_int_t
ngx_http_addition_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
{
    ngx_int_t                  rc;
    ngx_uint_t                 last;
    ngx_chain_t               *cl;
    ngx_http_request_t        *sr;
    ngx_http_addition_ctx_t   *ctx;
    ngx_http_addition_conf_t  *conf;

    if (in == NULL || r->header_only) {
        return ngx_http_next_body_filter(r, in);
    }

    ctx = ngx_http_get_module_ctx(r, ngx_http_addition_filter_module);

    if (ctx == NULL) {
        return ngx_http_next_body_filter(r, in);
    }

    conf = ngx_http_get_module_loc_conf(r, ngx_http_addition_filter_module);

    if (!ctx->before_body_sent) {
        ctx->before_body_sent = 1;

        if (conf->before_body.len) {
            if (ngx_http_subrequest(r, &conf->before_body, NULL, &sr, NULL, 0)
                != NGX_OK)
            {
                return NGX_ERROR;
            }
        }
    }

    if (conf->after_body.len == 0) {
        ngx_http_set_ctx(r, NULL, ngx_http_addition_filter_module);
        return ngx_http_next_body_filter(r, in);
    }

    last = 0;

    for (cl = in; cl; cl = cl->next) {
        if (cl->buf->last_buf) {
            cl->buf->last_buf = 0;
            cl->buf->last_in_chain = 1;
            cl->buf->sync = 1;
            last = 1;
        }
    }

    rc = ngx_http_next_body_filter(r, in);

    if (rc == NGX_ERROR || !last || conf->after_body.len == 0) {
        return rc;
    }

    if (ngx_http_subrequest(r, &conf->after_body, NULL, &sr, NULL, 0)
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    ngx_http_set_ctx(r, NULL, ngx_http_addition_filter_module);

    return ngx_http_send_special(r, NGX_HTTP_LAST);
}


static ngx_int_t
ngx_http_addition_filter_init(ngx_conf_t *cf)
{
    ngx_http_next_header_filter = ngx_http_top_header_filter;
    ngx_http_top_header_filter = ngx_http_addition_header_filter;

    ngx_http_next_body_filter = ngx_http_top_body_filter;
    ngx_http_top_body_filter = ngx_http_addition_body_filter;

    return NGX_OK;
}


static void *
ngx_http_addition_create_conf(ngx_conf_t *cf)
{
    ngx_http_addition_conf_t  *conf;

    conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_addition_conf_t));
    if (conf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc():
     *
     *     conf->before_body = { 0, NULL };
     *     conf->after_body = { 0, NULL };
     *     conf->types = { NULL };
     *     conf->types_keys = NULL;
     */

    return conf;
}


static char *
ngx_http_addition_merge_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_http_addition_conf_t *prev = parent;
    ngx_http_addition_conf_t *conf = child;

    ngx_conf_merge_str_value(conf->before_body, prev->before_body, "");
    ngx_conf_merge_str_value(conf->after_body, prev->after_body, "");

    if (ngx_http_merge_types(cf, &conf->types_keys, &conf->types,
                             &prev->types_keys, &prev->types,
                             ngx_http_html_default_types)
        != NGX_OK)
    {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}