view src/http/modules/ngx_http_addition_filter_module.c @ 7811:1ebd78df4ce7

Fixed handling of already closed connections. In limit_req, auth_delay, and upstream code to check for broken connections, tests for possible connection close by the client did not work if the connection was already closed when relevant event handler was set. This happened because there were no additional events in case of edge-triggered event methods, and read events were disabled in case of level-triggered ones. Fix is to explicitly post a read event if the c->read->ready flag is set.
author Maxim Dounin <mdounin@mdounin.ru>
date Sun, 28 Mar 2021 17:45:39 +0300
parents f583559aadc7
children
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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);

    r->preserve_body = 1;

    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;
}