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view src/http/modules/ngx_http_browser_module.c @ 7047:3fef8c5caa75

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Proxy: split configured header names and values. Previously, each configured header was represented in one of two ways, depending on whether or not its value included any variables. If the value didn't include any variables, then it would be represented as as a single script that contained complete header line with HTTP/1.1 delimiters, i.e.: "Header: value\r\n" But if the value included any variables, then it would be represented as a series of three scripts: first contained header name and the ": " delimiter, second evaluated to header value, and third contained only "\r\n", i.e.: "Header: " "$value" "\r\n" This commit changes that, so that each configured header is represented as a series of two scripts: first contains only header name, and second contains (or evaluates to) only header value, i.e.: "Header" "$value" or "Header" "value" This not only makes things more consistent, but also allows header name and value to be accessed separately. Signed-off-by: Piotr Sikora <piotrsikora@google.com>
author Piotr Sikora <piotrsikora@google.com>
date Wed, 15 Mar 2017 15:55:35 -0700
parents f84a98a03d0d
children 1b82e86dd3e7
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>


/*
 * The module can check browser versions conforming to the following formats:
 * X, X.X, X.X.X, and X.X.X.X.  The maximum values of each format may be
 * 4000, 4000.99, 4000.99.99, and 4000.99.99.99.
 */


#define  NGX_HTTP_MODERN_BROWSER   0
#define  NGX_HTTP_ANCIENT_BROWSER  1


typedef struct {
    u_char                      browser[12];
    size_t                      skip;
    size_t                      add;
    u_char                      name[12];
} ngx_http_modern_browser_mask_t;


typedef struct {
    ngx_uint_t                  version;
    size_t                      skip;
    size_t                      add;
    u_char                      name[12];
} ngx_http_modern_browser_t;


typedef struct {
    ngx_str_t                   name;
    ngx_http_get_variable_pt    handler;
    uintptr_t                   data;
} ngx_http_browser_variable_t;


typedef struct {
    ngx_array_t                *modern_browsers;
    ngx_array_t                *ancient_browsers;
    ngx_http_variable_value_t  *modern_browser_value;
    ngx_http_variable_value_t  *ancient_browser_value;

    unsigned                    modern_unlisted_browsers:1;
    unsigned                    netscape4:1;
} ngx_http_browser_conf_t;


static ngx_int_t ngx_http_msie_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_browser_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

static ngx_uint_t ngx_http_browser(ngx_http_request_t *r,
    ngx_http_browser_conf_t *cf);

static ngx_int_t ngx_http_browser_add_variable(ngx_conf_t *cf);
static void *ngx_http_browser_create_conf(ngx_conf_t *cf);
static char *ngx_http_browser_merge_conf(ngx_conf_t *cf, void *parent,
    void *child);
static int ngx_libc_cdecl ngx_http_modern_browser_sort(const void *one,
    const void *two);
static char *ngx_http_modern_browser(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_ancient_browser(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_modern_browser_value(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_ancient_browser_value(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_command_t  ngx_http_browser_commands[] = {

    { ngx_string("modern_browser"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE12,
      ngx_http_modern_browser,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("ancient_browser"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
      ngx_http_ancient_browser,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("modern_browser_value"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_modern_browser_value,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("ancient_browser_value"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_ancient_browser_value,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_browser_module_ctx = {
    ngx_http_browser_add_variable,         /* preconfiguration */
    NULL,                                  /* postconfiguration */

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

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

    ngx_http_browser_create_conf,          /* create location configuration */
    ngx_http_browser_merge_conf            /* merge location configuration */
};


ngx_module_t  ngx_http_browser_module = {
    NGX_MODULE_V1,
    &ngx_http_browser_module_ctx,          /* module context */
    ngx_http_browser_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_modern_browser_mask_t  ngx_http_modern_browser_masks[] = {

    /* Opera must be the first browser to check */

    /*
     * "Opera/7.50 (X11; FreeBSD i386; U)  [en]"
     * "Mozilla/5.0 (X11; FreeBSD i386; U) Opera 7.50  [en]"
     * "Mozilla/4.0 (compatible; MSIE 6.0; X11; FreeBSD i386) Opera 7.50  [en]"
     * "Opera/8.0 (Windows NT 5.1; U; ru)"
     * "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; en) Opera 8.0"
     * "Opera/9.01 (X11; FreeBSD 6 i386; U; en)"
     */

    { "opera",
      0,
      sizeof("Opera ") - 1,
      "Opera"},

    /* "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)" */

    { "msie",
      sizeof("Mozilla/4.0 (compatible; ") - 1,
      sizeof("MSIE ") - 1,
      "MSIE "},

    /*
     * "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020610"
     * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.5) Gecko/20031006"
     * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.6) Gecko/20040206
     *              Firefox/0.8"
     * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.7.8)
     *              Gecko/20050511 Firefox/1.0.4"
     * "Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.0.5) Gecko/20060729
     *              Firefox/1.5.0.5"
     */

    { "gecko",
      sizeof("Mozilla/5.0 (") - 1,
      sizeof("rv:") - 1,
      "rv:"},

    /*
     * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; ru-ru) AppleWebKit/125.2
     *              (KHTML, like Gecko) Safari/125.7"
     * "Mozilla/5.0 (SymbianOS/9.1; U; en-us) AppleWebKit/413
     *              (KHTML, like Gecko) Safari/413"
     * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en) AppleWebKit/418
     *              (KHTML, like Gecko) Safari/417.9.3"
     * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; ru-ru) AppleWebKit/418.8
     *              (KHTML, like Gecko) Safari/419.3"
     */

    { "safari",
      sizeof("Mozilla/5.0 (") - 1,
      sizeof("Safari/") - 1,
      "Safari/"},

    /*
     * "Mozilla/5.0 (compatible; Konqueror/3.1; Linux)"
     * "Mozilla/5.0 (compatible; Konqueror/3.4; Linux) KHTML/3.4.2 (like Gecko)"
     * "Mozilla/5.0 (compatible; Konqueror/3.5; FreeBSD) KHTML/3.5.1
     *              (like Gecko)"
     */

    { "konqueror",
      sizeof("Mozilla/5.0 (compatible; ") - 1,
      sizeof("Konqueror/") - 1,
      "Konqueror/"},

    { "", 0, 0, "" }

};


static ngx_http_browser_variable_t  ngx_http_browsers[] = {
    { ngx_string("msie"), ngx_http_msie_variable, 0 },
    { ngx_string("modern_browser"), ngx_http_browser_variable,
          NGX_HTTP_MODERN_BROWSER },
    { ngx_string("ancient_browser"), ngx_http_browser_variable,
          NGX_HTTP_ANCIENT_BROWSER },
    { ngx_null_string, NULL, 0 }
};


static ngx_int_t
ngx_http_browser_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    ngx_uint_t                rc;
    ngx_http_browser_conf_t  *cf;

    cf = ngx_http_get_module_loc_conf(r, ngx_http_browser_module);

    rc = ngx_http_browser(r, cf);

    if (data == NGX_HTTP_MODERN_BROWSER && rc == NGX_HTTP_MODERN_BROWSER) {
        *v = *cf->modern_browser_value;
        return NGX_OK;
    }

    if (data == NGX_HTTP_ANCIENT_BROWSER && rc == NGX_HTTP_ANCIENT_BROWSER) {
        *v = *cf->ancient_browser_value;
        return NGX_OK;
    }

    *v = ngx_http_variable_null_value;
    return NGX_OK;
}


static ngx_uint_t
ngx_http_browser(ngx_http_request_t *r, ngx_http_browser_conf_t *cf)
{
    size_t                      len;
    u_char                     *name, *ua, *last, c;
    ngx_str_t                  *ancient;
    ngx_uint_t                  i, version, ver, scale;
    ngx_http_modern_browser_t  *modern;

    if (r->headers_in.user_agent == NULL) {
        if (cf->modern_unlisted_browsers) {
            return NGX_HTTP_MODERN_BROWSER;
        }

        return NGX_HTTP_ANCIENT_BROWSER;
    }

    ua = r->headers_in.user_agent->value.data;
    len = r->headers_in.user_agent->value.len;
    last = ua + len;

    if (cf->modern_browsers) {
        modern = cf->modern_browsers->elts;

        for (i = 0; i < cf->modern_browsers->nelts; i++) {
            name = ua + modern[i].skip;

            if (name >= last) {
                continue;
            }

            name = (u_char *) ngx_strstr(name, modern[i].name);

            if (name == NULL) {
                continue;
            }

            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "browser: \"%s\"", name);

            name += modern[i].add;

            if (name >= last) {
                continue;
            }

            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "version: \"%ui\" \"%s\"", modern[i].version, name);

            version = 0;
            ver = 0;
            scale = 1000000;

            while (name < last) {

                c = *name++;

                if (c >= '0' && c <= '9') {
                    ver = ver * 10 + (c - '0');
                    continue;
                }

                if (c == '.') {
                    version += ver * scale;

                    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                                   "version: \"%ui\" \"%ui\"",
                                   modern[i].version, version);

                    if (version > modern[i].version) {
                        return NGX_HTTP_MODERN_BROWSER;
                    }

                    ver = 0;
                    scale /= 100;
                    continue;
                }

                break;
            }

            version += ver * scale;

            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "version: \"%ui\" \"%ui\"",
                           modern[i].version, version);

            if (version >= modern[i].version) {
                return NGX_HTTP_MODERN_BROWSER;
            }

            return NGX_HTTP_ANCIENT_BROWSER;
        }

        if (!cf->modern_unlisted_browsers) {
            return NGX_HTTP_ANCIENT_BROWSER;
        }
    }

    if (cf->netscape4) {
        if (len > sizeof("Mozilla/4.72 ") - 1
            && ngx_strncmp(ua, "Mozilla/", sizeof("Mozilla/") - 1) == 0
            && ua[8] > '0' && ua[8] < '5')
        {
            return NGX_HTTP_ANCIENT_BROWSER;
        }
    }

    if (cf->ancient_browsers) {
        ancient = cf->ancient_browsers->elts;

        for (i = 0; i < cf->ancient_browsers->nelts; i++) {
            if (len >= ancient[i].len
                && ngx_strstr(ua, ancient[i].data) != NULL)
            {
                return NGX_HTTP_ANCIENT_BROWSER;
            }
        }
    }

    if (cf->modern_unlisted_browsers) {
        return NGX_HTTP_MODERN_BROWSER;
    }

    return NGX_HTTP_ANCIENT_BROWSER;
}


static ngx_int_t
ngx_http_msie_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    if (r->headers_in.msie) {
        *v = ngx_http_variable_true_value;
        return NGX_OK;
    }

    *v = ngx_http_variable_null_value;
    return NGX_OK;
}


static ngx_int_t
ngx_http_browser_add_variable(ngx_conf_t *cf)
{
    ngx_http_browser_variable_t   *var;
    ngx_http_variable_t           *v;

    for (var = ngx_http_browsers; var->name.len; var++) {

        v = ngx_http_add_variable(cf, &var->name, NGX_HTTP_VAR_CHANGEABLE);
        if (v == NULL) {
            return NGX_ERROR;
        }

        v->get_handler = var->handler;
        v->data = var->data;
    }

    return NGX_OK;
}


static void *
ngx_http_browser_create_conf(ngx_conf_t *cf)
{
    ngx_http_browser_conf_t  *conf;

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

    /*
     * set by ngx_pcalloc():
     *
     *     conf->modern_browsers = NULL;
     *     conf->ancient_browsers = NULL;
     *     conf->modern_browser_value = NULL;
     *     conf->ancient_browser_value = NULL;
     *
     *     conf->modern_unlisted_browsers = 0;
     *     conf->netscape4 = 0;
     */

    return conf;
}


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

    ngx_uint_t                  i, n;
    ngx_http_modern_browser_t  *browsers, *opera;

    /*
     * At the merge the skip field is used to store the browser slot,
     * it will be used in sorting and then will overwritten
     * with a real skip value.  The zero value means Opera.
     */

    if (conf->modern_browsers == NULL && conf->modern_unlisted_browsers == 0) {
        conf->modern_browsers = prev->modern_browsers;
        conf->modern_unlisted_browsers = prev->modern_unlisted_browsers;

    } else if (conf->modern_browsers != NULL) {
        browsers = conf->modern_browsers->elts;

        for (i = 0; i < conf->modern_browsers->nelts; i++) {
            if (browsers[i].skip == 0) {
                goto found;
            }
        }

        /*
         * Opera may contain MSIE string, so if Opera was not enumerated
         * as modern browsers, then add it and set a unreachable version
         */

        opera = ngx_array_push(conf->modern_browsers);
        if (opera == NULL) {
            return NGX_CONF_ERROR;
        }

        opera->skip = 0;
        opera->version = 4001000000U;

        browsers = conf->modern_browsers->elts;

found:

        ngx_qsort(browsers, (size_t) conf->modern_browsers->nelts,
                  sizeof(ngx_http_modern_browser_t),
                  ngx_http_modern_browser_sort);

        for (i = 0; i < conf->modern_browsers->nelts; i++) {
             n = browsers[i].skip;

             browsers[i].skip = ngx_http_modern_browser_masks[n].skip;
             browsers[i].add = ngx_http_modern_browser_masks[n].add;
             (void) ngx_cpystrn(browsers[i].name,
                                ngx_http_modern_browser_masks[n].name, 12);
        }
    }

    if (conf->ancient_browsers == NULL && conf->netscape4 == 0) {
        conf->ancient_browsers = prev->ancient_browsers;
        conf->netscape4 = prev->netscape4;
    }

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

    if (conf->modern_browser_value == NULL) {
        conf->modern_browser_value = &ngx_http_variable_true_value;
    }

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

    if (conf->ancient_browser_value == NULL) {
        conf->ancient_browser_value = &ngx_http_variable_true_value;
    }

    return NGX_CONF_OK;
}


static int ngx_libc_cdecl
ngx_http_modern_browser_sort(const void *one, const void *two)
{
    ngx_http_modern_browser_t *first = (ngx_http_modern_browser_t *) one;
    ngx_http_modern_browser_t *second = (ngx_http_modern_browser_t *) two;

    return (first->skip - second->skip);
}


static char *
ngx_http_modern_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_browser_conf_t *bcf = conf;

    u_char                           c;
    ngx_str_t                       *value;
    ngx_uint_t                       i, n, version, ver, scale;
    ngx_http_modern_browser_t       *browser;
    ngx_http_modern_browser_mask_t  *mask;

    value = cf->args->elts;

    if (cf->args->nelts == 2) {
        if (ngx_strcmp(value[1].data, "unlisted") == 0) {
            bcf->modern_unlisted_browsers = 1;
            return NGX_CONF_OK;
        }

        return NGX_CONF_ERROR;
    }

    if (bcf->modern_browsers == NULL) {
        bcf->modern_browsers = ngx_array_create(cf->pool, 5,
                                            sizeof(ngx_http_modern_browser_t));
        if (bcf->modern_browsers == NULL) {
            return NGX_CONF_ERROR;
        }
    }

    browser = ngx_array_push(bcf->modern_browsers);
    if (browser == NULL) {
        return NGX_CONF_ERROR;
    }

    mask = ngx_http_modern_browser_masks;

    for (n = 0; mask[n].browser[0] != '\0'; n++) {
        if (ngx_strcasecmp(mask[n].browser, value[1].data) == 0) {
            goto found;
        }
    }

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "unknown browser name \"%V\"", &value[1]);

    return NGX_CONF_ERROR;

found:

    /*
     * at this stage the skip field is used to store the browser slot,
     * it will be used in sorting in merge stage and then will overwritten
     * with a real value
     */

    browser->skip = n;

    version = 0;
    ver = 0;
    scale = 1000000;

    for (i = 0; i < value[2].len; i++) {

        c = value[2].data[i];

        if (c >= '0' && c <= '9') {
            ver = ver * 10 + (c - '0');
            continue;
        }

        if (c == '.') {
            version += ver * scale;
            ver = 0;
            scale /= 100;
            continue;
        }

        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid browser version \"%V\"", &value[2]);

        return NGX_CONF_ERROR;
    }

    version += ver * scale;

    browser->version = version;

    return NGX_CONF_OK;
}


static char *
ngx_http_ancient_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_browser_conf_t *bcf = conf;

    ngx_str_t   *value, *browser;
    ngx_uint_t   i;

    value = cf->args->elts;

    for (i = 1; i < cf->args->nelts; i++) {
        if (ngx_strcmp(value[i].data, "netscape4") == 0) {
            bcf->netscape4 = 1;
            continue;
        }

        if (bcf->ancient_browsers == NULL) {
            bcf->ancient_browsers = ngx_array_create(cf->pool, 4,
                                                     sizeof(ngx_str_t));
            if (bcf->ancient_browsers == NULL) {
                return NGX_CONF_ERROR;
            }
        }

        browser = ngx_array_push(bcf->ancient_browsers);
        if (browser == NULL) {
            return NGX_CONF_ERROR;
        }

        *browser = value[i];
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_modern_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_browser_conf_t *bcf = conf;

    ngx_str_t  *value;

    bcf->modern_browser_value = ngx_palloc(cf->pool,
                                           sizeof(ngx_http_variable_value_t));
    if (bcf->modern_browser_value == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;

    bcf->modern_browser_value->len = value[1].len;
    bcf->modern_browser_value->valid = 1;
    bcf->modern_browser_value->no_cacheable = 0;
    bcf->modern_browser_value->not_found = 0;
    bcf->modern_browser_value->data = value[1].data;

    return NGX_CONF_OK;
}


static char *
ngx_http_ancient_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_browser_conf_t *bcf = conf;

    ngx_str_t  *value;

    bcf->ancient_browser_value = ngx_palloc(cf->pool,
                                            sizeof(ngx_http_variable_value_t));
    if (bcf->ancient_browser_value == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;

    bcf->ancient_browser_value->len = value[1].len;
    bcf->ancient_browser_value->valid = 1;
    bcf->ancient_browser_value->no_cacheable = 0;
    bcf->ancient_browser_value->not_found = 0;
    bcf->ancient_browser_value->data = value[1].data;

    return NGX_CONF_OK;
}