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view src/http/modules/ngx_http_headers_filter_module.c @ 4694:5b5c07dee156

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Upstream keepalive: "single" parameter deprecated. The original idea was to optimize edge cases in case of interchangeable backends, i.e. don't establish a new connection if we have any one cached. This causes more harm than good though, as it screws up underlying balancer's idea about backends used and may result in various unexpected problems.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 18 Jun 2012 14:23:42 +0000
parents 4c1e6cef1453
children 3cb5cf1e1439 4c3c409ed306
line wrap: on
line source


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


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


typedef struct ngx_http_header_val_s  ngx_http_header_val_t;

typedef ngx_int_t (*ngx_http_set_header_pt)(ngx_http_request_t *r,
    ngx_http_header_val_t *hv, ngx_str_t *value);


typedef struct {
    ngx_str_t                  name;
    ngx_uint_t                 offset;
    ngx_http_set_header_pt     handler;
} ngx_http_set_header_t;


struct ngx_http_header_val_s {
    ngx_http_complex_value_t   value;
    ngx_str_t                  key;
    ngx_http_set_header_pt     handler;
    ngx_uint_t                 offset;
};


typedef enum {
    NGX_HTTP_EXPIRES_OFF,
    NGX_HTTP_EXPIRES_EPOCH,
    NGX_HTTP_EXPIRES_MAX,
    NGX_HTTP_EXPIRES_ACCESS,
    NGX_HTTP_EXPIRES_MODIFIED,
    NGX_HTTP_EXPIRES_DAILY,
    NGX_HTTP_EXPIRES_UNSET
} ngx_http_expires_t;


typedef struct {
    ngx_http_expires_t       expires;
    time_t                   expires_time;
    ngx_array_t             *headers;
} ngx_http_headers_conf_t;


static ngx_int_t ngx_http_set_expires(ngx_http_request_t *r,
    ngx_http_headers_conf_t *conf);
static ngx_int_t ngx_http_add_cache_control(ngx_http_request_t *r,
    ngx_http_header_val_t *hv, ngx_str_t *value);
static ngx_int_t ngx_http_add_header(ngx_http_request_t *r,
    ngx_http_header_val_t *hv, ngx_str_t *value);
static ngx_int_t ngx_http_set_last_modified(ngx_http_request_t *r,
    ngx_http_header_val_t *hv, ngx_str_t *value);

static void *ngx_http_headers_create_conf(ngx_conf_t *cf);
static char *ngx_http_headers_merge_conf(ngx_conf_t *cf,
    void *parent, void *child);
static ngx_int_t ngx_http_headers_filter_init(ngx_conf_t *cf);
static char *ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_http_set_header_t  ngx_http_set_headers[] = {

    { ngx_string("Cache-Control"), 0, ngx_http_add_cache_control },

    { ngx_string("Last-Modified"),
                 offsetof(ngx_http_headers_out_t, last_modified),
                 ngx_http_set_last_modified },

    { ngx_null_string, 0, NULL }
};


static ngx_command_t  ngx_http_headers_filter_commands[] = {

    { ngx_string("expires"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
                        |NGX_CONF_TAKE12,
      ngx_http_headers_expires,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL},

    { ngx_string("add_header"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
                        |NGX_CONF_TAKE2,
      ngx_http_headers_add,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL},

      ngx_null_command
};


static ngx_http_module_t  ngx_http_headers_filter_module_ctx = {
    NULL,                                  /* preconfiguration */
    ngx_http_headers_filter_init,          /* postconfiguration */

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

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

    ngx_http_headers_create_conf,          /* create location configuration */
    ngx_http_headers_merge_conf            /* merge location configuration */
};


ngx_module_t  ngx_http_headers_filter_module = {
    NGX_MODULE_V1,
    &ngx_http_headers_filter_module_ctx,   /* module context */
    ngx_http_headers_filter_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_int_t
ngx_http_headers_filter(ngx_http_request_t *r)
{
    ngx_str_t                 value;
    ngx_uint_t                i;
    ngx_http_header_val_t    *h;
    ngx_http_headers_conf_t  *conf;

    conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module);

    if ((conf->expires == NGX_HTTP_EXPIRES_OFF && conf->headers == NULL)
        || r != r->main
        || (r->headers_out.status != NGX_HTTP_OK
            && r->headers_out.status != NGX_HTTP_NO_CONTENT
            && r->headers_out.status != NGX_HTTP_PARTIAL_CONTENT
            && r->headers_out.status != NGX_HTTP_MOVED_PERMANENTLY
            && r->headers_out.status != NGX_HTTP_MOVED_TEMPORARILY
            && r->headers_out.status != NGX_HTTP_SEE_OTHER
            && r->headers_out.status != NGX_HTTP_NOT_MODIFIED
            && r->headers_out.status != NGX_HTTP_TEMPORARY_REDIRECT))
    {
        return ngx_http_next_header_filter(r);
    }

    if (conf->expires != NGX_HTTP_EXPIRES_OFF) {
        if (ngx_http_set_expires(r, conf) != NGX_OK) {
            return NGX_ERROR;
        }
    }

    if (conf->headers) {
        h = conf->headers->elts;
        for (i = 0; i < conf->headers->nelts; i++) {

            if (ngx_http_complex_value(r, &h[i].value, &value) != NGX_OK) {
                return NGX_ERROR;
            }

            if (h[i].handler(r, &h[i], &value) != NGX_OK) {
                return NGX_ERROR;
            }
        }
    }

    return ngx_http_next_header_filter(r);
}


static ngx_int_t
ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf)
{
    size_t            len;
    time_t            now, expires_time, max_age;
    ngx_uint_t        i;
    ngx_table_elt_t  *expires, *cc, **ccp;

    expires = r->headers_out.expires;

    if (expires == NULL) {

        expires = ngx_list_push(&r->headers_out.headers);
        if (expires == NULL) {
            return NGX_ERROR;
        }

        r->headers_out.expires = expires;

        expires->hash = 1;
        ngx_str_set(&expires->key, "Expires");
    }

    len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT");
    expires->value.len = len - 1;

    ccp = r->headers_out.cache_control.elts;

    if (ccp == NULL) {

        if (ngx_array_init(&r->headers_out.cache_control, r->pool,
                           1, sizeof(ngx_table_elt_t *))
            != NGX_OK)
        {
            return NGX_ERROR;
        }

        ccp = ngx_array_push(&r->headers_out.cache_control);
        if (ccp == NULL) {
            return NGX_ERROR;
        }

        cc = ngx_list_push(&r->headers_out.headers);
        if (cc == NULL) {
            return NGX_ERROR;
        }

        cc->hash = 1;
        ngx_str_set(&cc->key, "Cache-Control");
        *ccp = cc;

    } else {
        for (i = 1; i < r->headers_out.cache_control.nelts; i++) {
            ccp[i]->hash = 0;
        }

        cc = ccp[0];
    }

    if (conf->expires == NGX_HTTP_EXPIRES_EPOCH) {
        expires->value.data = (u_char *) "Thu, 01 Jan 1970 00:00:01 GMT";
        ngx_str_set(&cc->value, "no-cache");
        return NGX_OK;
    }

    if (conf->expires == NGX_HTTP_EXPIRES_MAX) {
        expires->value.data = (u_char *) "Thu, 31 Dec 2037 23:55:55 GMT";
        /* 10 years */
        ngx_str_set(&cc->value, "max-age=315360000");
        return NGX_OK;
    }

    expires->value.data = ngx_pnalloc(r->pool, len);
    if (expires->value.data == NULL) {
        return NGX_ERROR;
    }

    if (conf->expires_time == 0 && conf->expires != NGX_HTTP_EXPIRES_DAILY) {
        ngx_memcpy(expires->value.data, ngx_cached_http_time.data,
                   ngx_cached_http_time.len + 1);
        ngx_str_set(&cc->value, "max-age=0");
        return NGX_OK;
    }

    now = ngx_time();

    if (conf->expires == NGX_HTTP_EXPIRES_DAILY) {
        expires_time = ngx_next_time(conf->expires_time);
        max_age = expires_time - now;

    } else if (conf->expires == NGX_HTTP_EXPIRES_ACCESS
               || r->headers_out.last_modified_time == -1)
    {
        expires_time = now + conf->expires_time;
        max_age = conf->expires_time;

    } else {
        expires_time = r->headers_out.last_modified_time + conf->expires_time;
        max_age = expires_time - now;
    }

    ngx_http_time(expires->value.data, expires_time);

    if (conf->expires_time < 0 || max_age < 0) {
        ngx_str_set(&cc->value, "no-cache");
        return NGX_OK;
    }

    cc->value.data = ngx_pnalloc(r->pool,
                                 sizeof("max-age=") + NGX_TIME_T_LEN + 1);
    if (cc->value.data == NULL) {
        return NGX_ERROR;
    }

    cc->value.len = ngx_sprintf(cc->value.data, "max-age=%T", max_age)
                    - cc->value.data;

    return NGX_OK;
}


static ngx_int_t
ngx_http_add_header(ngx_http_request_t *r, ngx_http_header_val_t *hv,
    ngx_str_t *value)
{
    ngx_table_elt_t  *h;

    if (value->len) {
        h = ngx_list_push(&r->headers_out.headers);
        if (h == NULL) {
            return NGX_ERROR;
        }

        h->hash = 1;
        h->key = hv->key;
        h->value = *value;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_add_cache_control(ngx_http_request_t *r, ngx_http_header_val_t *hv,
    ngx_str_t *value)
{
    ngx_table_elt_t  *cc, **ccp;

    ccp = r->headers_out.cache_control.elts;

    if (ccp == NULL) {

        if (ngx_array_init(&r->headers_out.cache_control, r->pool,
                           1, sizeof(ngx_table_elt_t *))
            != NGX_OK)
        {
            return NGX_ERROR;
        }
    }

    ccp = ngx_array_push(&r->headers_out.cache_control);
    if (ccp == NULL) {
        return NGX_ERROR;
    }

    cc = ngx_list_push(&r->headers_out.headers);
    if (cc == NULL) {
        return NGX_ERROR;
    }

    cc->hash = 1;
    ngx_str_set(&cc->key, "Cache-Control");
    cc->value = *value;

    *ccp = cc;

    return NGX_OK;
}


static ngx_int_t
ngx_http_set_last_modified(ngx_http_request_t *r, ngx_http_header_val_t *hv,
    ngx_str_t *value)
{
    ngx_table_elt_t  *h, **old;

    old = (ngx_table_elt_t **) ((char *) &r->headers_out + hv->offset);

    r->headers_out.last_modified_time = -1;

    if (*old == NULL) {

        if (value->len == 0) {
            return NGX_OK;
        }

        h = ngx_list_push(&r->headers_out.headers);
        if (h == NULL) {
            return NGX_ERROR;
        }

        *old = h;

    } else {
        h = *old;

        if (value->len == 0) {
            h->hash = 0;
            return NGX_OK;
        }
    }

    h->hash = 1;
    h->key = hv->key;
    h->value = *value;

    return NGX_OK;
}


static void *
ngx_http_headers_create_conf(ngx_conf_t *cf)
{
    ngx_http_headers_conf_t  *conf;

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

    /*
     * set by ngx_pcalloc():
     *
     *     conf->headers = NULL;
     *     conf->expires_time = 0;
     */

    conf->expires = NGX_HTTP_EXPIRES_UNSET;

    return conf;
}


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

    if (conf->expires == NGX_HTTP_EXPIRES_UNSET) {
        conf->expires = prev->expires;
        conf->expires_time = prev->expires_time;

        if (conf->expires == NGX_HTTP_EXPIRES_UNSET) {
            conf->expires = NGX_HTTP_EXPIRES_OFF;
        }
    }

    if (conf->headers == NULL) {
        conf->headers = prev->headers;
    }

    return NGX_CONF_OK;
}


static ngx_int_t
ngx_http_headers_filter_init(ngx_conf_t *cf)
{
    ngx_http_next_header_filter = ngx_http_top_header_filter;
    ngx_http_top_header_filter = ngx_http_headers_filter;

    return NGX_OK;
}


static char *
ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_headers_conf_t *hcf = conf;

    ngx_uint_t   minus, n;
    ngx_str_t   *value;

    if (hcf->expires != NGX_HTTP_EXPIRES_UNSET) {
        return "is duplicate";
    }

    value = cf->args->elts;

    if (cf->args->nelts == 2) {

        if (ngx_strcmp(value[1].data, "epoch") == 0) {
            hcf->expires = NGX_HTTP_EXPIRES_EPOCH;
            return NGX_CONF_OK;
        }

        if (ngx_strcmp(value[1].data, "max") == 0) {
            hcf->expires = NGX_HTTP_EXPIRES_MAX;
            return NGX_CONF_OK;
        }

        if (ngx_strcmp(value[1].data, "off") == 0) {
            hcf->expires = NGX_HTTP_EXPIRES_OFF;
            return NGX_CONF_OK;
        }

        hcf->expires = NGX_HTTP_EXPIRES_ACCESS;

        n = 1;

    } else { /* cf->args->nelts == 3 */

        if (ngx_strcmp(value[1].data, "modified") != 0) {
            return "invalid value";
        }

        hcf->expires = NGX_HTTP_EXPIRES_MODIFIED;

        n = 2;
    }

    if (value[n].data[0] == '@') {
        value[n].data++;
        value[n].len--;
        minus = 0;

        if (hcf->expires == NGX_HTTP_EXPIRES_MODIFIED) {
            return "daily time cannot be used with \"modified\" parameter";
        }

        hcf->expires = NGX_HTTP_EXPIRES_DAILY;

    } else if (value[n].data[0] == '+') {
        value[n].data++;
        value[n].len--;
        minus = 0;

    } else if (value[n].data[0] == '-') {
        value[n].data++;
        value[n].len--;
        minus = 1;

    } else {
        minus = 0;
    }

    hcf->expires_time = ngx_parse_time(&value[n], 1);

    if (hcf->expires_time == (time_t) NGX_ERROR) {
        return "invalid value";
    }

    if (hcf->expires == NGX_HTTP_EXPIRES_DAILY
        && hcf->expires_time > 24 * 60 * 60)
    {
        return "daily time value must be less than 24 hours";
    }

    if (minus) {
        hcf->expires_time = - hcf->expires_time;
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_headers_conf_t *hcf = conf;

    ngx_str_t                         *value;
    ngx_uint_t                         i;
    ngx_http_header_val_t             *hv;
    ngx_http_set_header_t             *set;
    ngx_http_compile_complex_value_t   ccv;

    value = cf->args->elts;

    if (hcf->headers == NULL) {
        hcf->headers = ngx_array_create(cf->pool, 1,
                                        sizeof(ngx_http_header_val_t));
        if (hcf->headers == NULL) {
            return NGX_CONF_ERROR;
        }
    }

    hv = ngx_array_push(hcf->headers);
    if (hv == NULL) {
        return NGX_CONF_ERROR;
    }

    hv->key = value[1];
    hv->handler = ngx_http_add_header;
    hv->offset = 0;

    set = ngx_http_set_headers;
    for (i = 0; set[i].name.len; i++) {
        if (ngx_strcasecmp(value[1].data, set[i].name.data) != 0) {
            continue;
        }

        hv->offset = set[i].offset;
        hv->handler = set[i].handler;

        break;
    }

    if (value[2].len == 0) {
        ngx_memzero(&hv->value, sizeof(ngx_http_complex_value_t));
        return NGX_CONF_OK;
    }

    ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = &value[2];
    ccv.complex_value = &hv->value;

    if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}