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view src/http/modules/ngx_http_rewrite_module.c @ 5095:4fbef397c753

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SNI: added restriction on requesting host other than negotiated. According to RFC 6066, client is not supposed to request a different server name at the application layer. Server implementations that rely upon these names being equal must validate that a client did not send a different name in HTTP request. Current versions of Apache HTTP server always return 400 "Bad Request" in such cases. There exist implementations however (e.g., SPDY) that rely on being able to request different host names in one connection. Given this, we only reject requests with differing host names if verification of client certificates is enabled in a corresponding server configuration. An example of configuration that might not work as expected: server { listen 433 ssl default; return 404; } server { listen 433 ssl; server_name example.org; ssl_client_certificate org.cert; ssl_verify_client on; } server { listen 433 ssl; server_name example.com; ssl_client_certificate com.cert; ssl_verify_client on; } Previously, a client was able to request example.com by presenting a certificate for example.org, and vice versa.
author Valentin Bartenev <vbart@nginx.com>
date Wed, 27 Feb 2013 17:41:34 +0000
parents 8b635cf36ccc
children 16a371063d20
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_array_t  *codes;        /* uintptr_t */

    ngx_uint_t    stack_size;

    ngx_flag_t    log;
    ngx_flag_t    uninitialized_variable_warn;
} ngx_http_rewrite_loc_conf_t;


static void *ngx_http_rewrite_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_rewrite_merge_loc_conf(ngx_conf_t *cf,
    void *parent, void *child);
static ngx_int_t ngx_http_rewrite_init(ngx_conf_t *cf);
static char *ngx_http_rewrite(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_http_rewrite_return(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_rewrite_break(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_http_rewrite_if(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char * ngx_http_rewrite_if_condition(ngx_conf_t *cf,
    ngx_http_rewrite_loc_conf_t *lcf);
static char *ngx_http_rewrite_variable(ngx_conf_t *cf,
    ngx_http_rewrite_loc_conf_t *lcf, ngx_str_t *value);
static char *ngx_http_rewrite_set(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char * ngx_http_rewrite_value(ngx_conf_t *cf,
    ngx_http_rewrite_loc_conf_t *lcf, ngx_str_t *value);


static ngx_command_t  ngx_http_rewrite_commands[] = {

    { ngx_string("rewrite"),
      NGX_HTTP_SRV_CONF|NGX_HTTP_SIF_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
                       |NGX_CONF_TAKE23,
      ngx_http_rewrite,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("return"),
      NGX_HTTP_SRV_CONF|NGX_HTTP_SIF_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
                       |NGX_CONF_TAKE12,
      ngx_http_rewrite_return,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("break"),
      NGX_HTTP_SRV_CONF|NGX_HTTP_SIF_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
                       |NGX_CONF_NOARGS,
      ngx_http_rewrite_break,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("if"),
      NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_BLOCK|NGX_CONF_1MORE,
      ngx_http_rewrite_if,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("set"),
      NGX_HTTP_SRV_CONF|NGX_HTTP_SIF_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
                       |NGX_CONF_TAKE2,
      ngx_http_rewrite_set,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("rewrite_log"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_SIF_CONF|NGX_HTTP_LOC_CONF
                        |NGX_HTTP_LIF_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_rewrite_loc_conf_t, log),
      NULL },

    { ngx_string("uninitialized_variable_warn"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_SIF_CONF|NGX_HTTP_LOC_CONF
                        |NGX_HTTP_LIF_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_rewrite_loc_conf_t, uninitialized_variable_warn),
      NULL },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_rewrite_module_ctx = {
    NULL,                                  /* preconfiguration */
    ngx_http_rewrite_init,                 /* postconfiguration */

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

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

    ngx_http_rewrite_create_loc_conf,      /* create location configuration */
    ngx_http_rewrite_merge_loc_conf        /* merge location configuration */
};


ngx_module_t  ngx_http_rewrite_module = {
    NGX_MODULE_V1,
    &ngx_http_rewrite_module_ctx,          /* module context */
    ngx_http_rewrite_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_int_t
ngx_http_rewrite_handler(ngx_http_request_t *r)
{
    ngx_int_t                     index;
    ngx_http_script_code_pt       code;
    ngx_http_script_engine_t     *e;
    ngx_http_core_srv_conf_t     *cscf;
    ngx_http_core_main_conf_t    *cmcf;
    ngx_http_rewrite_loc_conf_t  *rlcf;

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);
    cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);
    index = cmcf->phase_engine.location_rewrite_index;

    if (r->phase_handler == index && r->loc_conf == cscf->ctx->loc_conf) {
        /* skipping location rewrite phase for server null location */
        return NGX_DECLINED;
    }

    rlcf = ngx_http_get_module_loc_conf(r, ngx_http_rewrite_module);

    if (rlcf->codes == NULL) {
        return NGX_DECLINED;
    }

    e = ngx_pcalloc(r->pool, sizeof(ngx_http_script_engine_t));
    if (e == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    e->sp = ngx_pcalloc(r->pool,
                        rlcf->stack_size * sizeof(ngx_http_variable_value_t));
    if (e->sp == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    e->ip = rlcf->codes->elts;
    e->request = r;
    e->quote = 1;
    e->log = rlcf->log;
    e->status = NGX_DECLINED;

    while (*(uintptr_t *) e->ip) {
        code = *(ngx_http_script_code_pt *) e->ip;
        code(e);
    }

    if (e->status < NGX_HTTP_BAD_REQUEST) {
        return e->status;
    }

    if (r->err_status == 0) {
        return e->status;
    }

    return r->err_status;
}


static ngx_int_t
ngx_http_rewrite_var(ngx_http_request_t *r, ngx_http_variable_value_t *v,
    uintptr_t data)
{
    ngx_http_variable_t          *var;
    ngx_http_core_main_conf_t    *cmcf;
    ngx_http_rewrite_loc_conf_t  *rlcf;

    rlcf = ngx_http_get_module_loc_conf(r, ngx_http_rewrite_module);

    if (rlcf->uninitialized_variable_warn == 0) {
        *v = ngx_http_variable_null_value;
        return NGX_OK;
    }

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    var = cmcf->variables.elts;

    /*
     * the ngx_http_rewrite_module sets variables directly in r->variables,
     * and they should be handled by ngx_http_get_indexed_variable(),
     * so the handler is called only if the variable is not initialized
     */

    ngx_log_error(NGX_LOG_WARN, r->connection->log, 0,
                  "using uninitialized \"%V\" variable", &var[data].name);

    *v = ngx_http_variable_null_value;

    return NGX_OK;
}


static void *
ngx_http_rewrite_create_loc_conf(ngx_conf_t *cf)
{
    ngx_http_rewrite_loc_conf_t  *conf;

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

    conf->stack_size = NGX_CONF_UNSET_UINT;
    conf->log = NGX_CONF_UNSET;
    conf->uninitialized_variable_warn = NGX_CONF_UNSET;

    return conf;
}


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

    uintptr_t  *code;

    ngx_conf_merge_value(conf->log, prev->log, 0);
    ngx_conf_merge_value(conf->uninitialized_variable_warn,
                         prev->uninitialized_variable_warn, 1);
    ngx_conf_merge_uint_value(conf->stack_size, prev->stack_size, 10);

    if (conf->codes == NULL) {
        return NGX_CONF_OK;
    }

    if (conf->codes == prev->codes) {
        return NGX_CONF_OK;
    }

    code = ngx_array_push_n(conf->codes, sizeof(uintptr_t));
    if (code == NULL) {
        return NGX_CONF_ERROR;
    }

    *code = (uintptr_t) NULL;

    return NGX_CONF_OK;
}


static ngx_int_t
ngx_http_rewrite_init(ngx_conf_t *cf)
{
    ngx_http_handler_pt        *h;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

    h = ngx_array_push(&cmcf->phases[NGX_HTTP_SERVER_REWRITE_PHASE].handlers);
    if (h == NULL) {
        return NGX_ERROR;
    }

    *h = ngx_http_rewrite_handler;

    h = ngx_array_push(&cmcf->phases[NGX_HTTP_REWRITE_PHASE].handlers);
    if (h == NULL) {
        return NGX_ERROR;
    }

    *h = ngx_http_rewrite_handler;

    return NGX_OK;
}


static char *
ngx_http_rewrite(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_rewrite_loc_conf_t  *lcf = conf;

    ngx_str_t                         *value;
    ngx_uint_t                         last;
    ngx_regex_compile_t                rc;
    ngx_http_script_code_pt           *code;
    ngx_http_script_compile_t          sc;
    ngx_http_script_regex_code_t      *regex;
    ngx_http_script_regex_end_code_t  *regex_end;
    u_char                             errstr[NGX_MAX_CONF_ERRSTR];

    regex = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                       sizeof(ngx_http_script_regex_code_t));
    if (regex == NULL) {
        return NGX_CONF_ERROR;
    }

    ngx_memzero(regex, sizeof(ngx_http_script_regex_code_t));

    value = cf->args->elts;

    ngx_memzero(&rc, sizeof(ngx_regex_compile_t));

    rc.pattern = value[1];
    rc.err.len = NGX_MAX_CONF_ERRSTR;
    rc.err.data = errstr;

    /* TODO: NGX_REGEX_CASELESS */

    regex->regex = ngx_http_regex_compile(cf, &rc);
    if (regex->regex == NULL) {
        return NGX_CONF_ERROR;
    }

    regex->code = ngx_http_script_regex_start_code;
    regex->uri = 1;
    regex->name = value[1];

    if (value[2].data[value[2].len - 1] == '?') {

        /* the last "?" drops the original arguments */
        value[2].len--;

    } else {
        regex->add_args = 1;
    }

    last = 0;

    if (ngx_strncmp(value[2].data, "http://", sizeof("http://") - 1) == 0
        || ngx_strncmp(value[2].data, "https://", sizeof("https://") - 1) == 0
        || ngx_strncmp(value[2].data, "$scheme", sizeof("$scheme") - 1) == 0)
    {
        regex->status = NGX_HTTP_MOVED_TEMPORARILY;
        regex->redirect = 1;
        last = 1;
    }

    if (cf->args->nelts == 4) {
        if (ngx_strcmp(value[3].data, "last") == 0) {
            last = 1;

        } else if (ngx_strcmp(value[3].data, "break") == 0) {
            regex->break_cycle = 1;
            last = 1;

        } else if (ngx_strcmp(value[3].data, "redirect") == 0) {
            regex->status = NGX_HTTP_MOVED_TEMPORARILY;
            regex->redirect = 1;
            last = 1;

        } else if (ngx_strcmp(value[3].data, "permanent") == 0) {
            regex->status = NGX_HTTP_MOVED_PERMANENTLY;
            regex->redirect = 1;
            last = 1;

        } else {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid parameter \"%V\"", &value[3]);
            return NGX_CONF_ERROR;
        }
    }

    ngx_memzero(&sc, sizeof(ngx_http_script_compile_t));

    sc.cf = cf;
    sc.source = &value[2];
    sc.lengths = &regex->lengths;
    sc.values = &lcf->codes;
    sc.variables = ngx_http_script_variables_count(&value[2]);
    sc.main = regex;
    sc.complete_lengths = 1;
    sc.compile_args = !regex->redirect;

    if (ngx_http_script_compile(&sc) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    regex = sc.main;

    regex->size = sc.size;
    regex->args = sc.args;

    if (sc.variables == 0 && !sc.dup_capture) {
        regex->lengths = NULL;
    }

    regex_end = ngx_http_script_add_code(lcf->codes,
                                      sizeof(ngx_http_script_regex_end_code_t),
                                      &regex);
    if (regex_end == NULL) {
        return NGX_CONF_ERROR;
    }

    regex_end->code = ngx_http_script_regex_end_code;
    regex_end->uri = regex->uri;
    regex_end->args = regex->args;
    regex_end->add_args = regex->add_args;
    regex_end->redirect = regex->redirect;

    if (last) {
        code = ngx_http_script_add_code(lcf->codes, sizeof(uintptr_t), &regex);
        if (code == NULL) {
            return NGX_CONF_ERROR;
        }

        *code = NULL;
    }

    regex->next = (u_char *) lcf->codes->elts + lcf->codes->nelts
                                              - (u_char *) regex;

    return NGX_CONF_OK;
}


static char *
ngx_http_rewrite_return(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_rewrite_loc_conf_t  *lcf = conf;

    u_char                            *p;
    ngx_str_t                         *value, *v;
    ngx_http_script_return_code_t     *ret;
    ngx_http_compile_complex_value_t   ccv;

    ret = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                     sizeof(ngx_http_script_return_code_t));
    if (ret == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;

    ngx_memzero(ret, sizeof(ngx_http_script_return_code_t));

    ret->code = ngx_http_script_return_code;

    p = value[1].data;

    ret->status = ngx_atoi(p, value[1].len);

    if (ret->status == (uintptr_t) NGX_ERROR) {

        if (cf->args->nelts == 2
            && (ngx_strncmp(p, "http://", sizeof("http://") - 1) == 0
                || ngx_strncmp(p, "https://", sizeof("https://") - 1) == 0
                || ngx_strncmp(p, "$scheme", sizeof("$scheme") - 1) == 0))
        {
            ret->status = NGX_HTTP_MOVED_TEMPORARILY;
            v = &value[1];

        } else {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid return code \"%V\"", &value[1]);
            return NGX_CONF_ERROR;
        }

    } else {

        if (ret->status > 999) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid return code \"%V\"", &value[1]);
            return NGX_CONF_ERROR;
        }

        if (cf->args->nelts == 2) {
            return NGX_CONF_OK;
        }

        v = &value[2];
    }

    ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = v;
    ccv.complex_value = &ret->text;

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

    return NGX_CONF_OK;
}


static char *
ngx_http_rewrite_break(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_rewrite_loc_conf_t *lcf = conf;

    ngx_http_script_code_pt  *code;

    code = ngx_http_script_start_code(cf->pool, &lcf->codes, sizeof(uintptr_t));
    if (code == NULL) {
        return NGX_CONF_ERROR;
    }

    *code = ngx_http_script_break_code;

    return NGX_CONF_OK;
}


static char *
ngx_http_rewrite_if(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_rewrite_loc_conf_t  *lcf = conf;

    void                         *mconf;
    char                         *rv;
    u_char                       *elts;
    ngx_uint_t                    i;
    ngx_conf_t                    save;
    ngx_http_module_t            *module;
    ngx_http_conf_ctx_t          *ctx, *pctx;
    ngx_http_core_loc_conf_t     *clcf, *pclcf;
    ngx_http_script_if_code_t    *if_code;
    ngx_http_rewrite_loc_conf_t  *nlcf;

    ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t));
    if (ctx == NULL) {
        return NGX_CONF_ERROR;
    }

    pctx = cf->ctx;
    ctx->main_conf = pctx->main_conf;
    ctx->srv_conf = pctx->srv_conf;

    ctx->loc_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module);
    if (ctx->loc_conf == NULL) {
        return NGX_CONF_ERROR;
    }

    for (i = 0; ngx_modules[i]; i++) {
        if (ngx_modules[i]->type != NGX_HTTP_MODULE) {
            continue;
        }

        module = ngx_modules[i]->ctx;

        if (module->create_loc_conf) {

            mconf = module->create_loc_conf(cf);
            if (mconf == NULL) {
                 return NGX_CONF_ERROR;
            }

            ctx->loc_conf[ngx_modules[i]->ctx_index] = mconf;
        }
    }

    pclcf = pctx->loc_conf[ngx_http_core_module.ctx_index];

    clcf = ctx->loc_conf[ngx_http_core_module.ctx_index];
    clcf->loc_conf = ctx->loc_conf;
    clcf->name = pclcf->name;
    clcf->noname = 1;

    if (ngx_http_add_location(cf, &pclcf->locations, clcf) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    if (ngx_http_rewrite_if_condition(cf, lcf) != NGX_CONF_OK) {
        return NGX_CONF_ERROR;
    }

    if_code = ngx_array_push_n(lcf->codes, sizeof(ngx_http_script_if_code_t));
    if (if_code == NULL) {
        return NGX_CONF_ERROR;
    }

    if_code->code = ngx_http_script_if_code;

    elts = lcf->codes->elts;


    /* the inner directives must be compiled to the same code array */

    nlcf = ctx->loc_conf[ngx_http_rewrite_module.ctx_index];
    nlcf->codes = lcf->codes;


    save = *cf;
    cf->ctx = ctx;

    if (pclcf->name.len == 0) {
        if_code->loc_conf = NULL;
        cf->cmd_type = NGX_HTTP_SIF_CONF;

    } else {
        if_code->loc_conf = ctx->loc_conf;
        cf->cmd_type = NGX_HTTP_LIF_CONF;
    }

    rv = ngx_conf_parse(cf, NULL);

    *cf = save;

    if (rv != NGX_CONF_OK) {
        return rv;
    }


    if (elts != lcf->codes->elts) {
        if_code = (ngx_http_script_if_code_t *)
                   ((u_char *) if_code + ((u_char *) lcf->codes->elts - elts));
    }

    if_code->next = (u_char *) lcf->codes->elts + lcf->codes->nelts
                                                - (u_char *) if_code;

    /* the code array belong to parent block */

    nlcf->codes = NULL;

    return NGX_CONF_OK;
}


static char *
ngx_http_rewrite_if_condition(ngx_conf_t *cf, ngx_http_rewrite_loc_conf_t *lcf)
{
    u_char                        *p;
    size_t                         len;
    ngx_str_t                     *value;
    ngx_uint_t                     cur, last;
    ngx_regex_compile_t            rc;
    ngx_http_script_code_pt       *code;
    ngx_http_script_file_code_t   *fop;
    ngx_http_script_regex_code_t  *regex;
    u_char                         errstr[NGX_MAX_CONF_ERRSTR];

    value = cf->args->elts;
    last = cf->args->nelts - 1;

    if (value[1].len < 1 || value[1].data[0] != '(') {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid condition \"%V\"", &value[1]);
        return NGX_CONF_ERROR;
    }

    if (value[1].len == 1) {
        cur = 2;

    } else {
        cur = 1;
        value[1].len--;
        value[1].data++;
    }

    if (value[last].len < 1 || value[last].data[value[last].len - 1] != ')') {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid condition \"%V\"", &value[last]);
        return NGX_CONF_ERROR;
    }

    if (value[last].len == 1) {
        last--;

    } else {
        value[last].len--;
        value[last].data[value[last].len] = '\0';
    }

    len = value[cur].len;
    p = value[cur].data;

    if (len > 1 && p[0] == '$') {

        if (cur != last && cur + 2 != last) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid condition \"%V\"", &value[cur]);
            return NGX_CONF_ERROR;
        }

        if (ngx_http_rewrite_variable(cf, lcf, &value[cur]) != NGX_CONF_OK) {
            return NGX_CONF_ERROR;
        }

        if (cur == last) {
            return NGX_CONF_OK;
        }

        cur++;

        len = value[cur].len;
        p = value[cur].data;

        if (len == 1 && p[0] == '=') {

            if (ngx_http_rewrite_value(cf, lcf, &value[last]) != NGX_CONF_OK) {
                return NGX_CONF_ERROR;
            }

            code = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                              sizeof(uintptr_t));
            if (code == NULL) {
                return NGX_CONF_ERROR;
            }

            *code = ngx_http_script_equal_code;

            return NGX_CONF_OK;
        }

        if (len == 2 && p[0] == '!' && p[1] == '=') {

            if (ngx_http_rewrite_value(cf, lcf, &value[last]) != NGX_CONF_OK) {
                return NGX_CONF_ERROR;
            }

            code = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                              sizeof(uintptr_t));
            if (code == NULL) {
                return NGX_CONF_ERROR;
            }

            *code = ngx_http_script_not_equal_code;
            return NGX_CONF_OK;
        }

        if ((len == 1 && p[0] == '~')
            || (len == 2 && p[0] == '~' && p[1] == '*')
            || (len == 2 && p[0] == '!' && p[1] == '~')
            || (len == 3 && p[0] == '!' && p[1] == '~' && p[2] == '*'))
        {
            regex = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                         sizeof(ngx_http_script_regex_code_t));
            if (regex == NULL) {
                return NGX_CONF_ERROR;
            }

            ngx_memzero(regex, sizeof(ngx_http_script_regex_code_t));

            ngx_memzero(&rc, sizeof(ngx_regex_compile_t));

            rc.pattern = value[last];
            rc.options = (p[len - 1] == '*') ? NGX_REGEX_CASELESS : 0;
            rc.err.len = NGX_MAX_CONF_ERRSTR;
            rc.err.data = errstr;

            regex->regex = ngx_http_regex_compile(cf, &rc);
            if (regex->regex == NULL) {
                return NGX_CONF_ERROR;
            }

            regex->code = ngx_http_script_regex_start_code;
            regex->next = sizeof(ngx_http_script_regex_code_t);
            regex->test = 1;
            if (p[0] == '!') {
                regex->negative_test = 1;
            }
            regex->name = value[last];

            return NGX_CONF_OK;
        }

        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "unexpected \"%V\" in condition", &value[cur]);
        return NGX_CONF_ERROR;

    } else if ((len == 2 && p[0] == '-')
               || (len == 3 && p[0] == '!' && p[1] == '-'))
    {
        if (cur + 1 != last) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "invalid condition \"%V\"", &value[cur]);
            return NGX_CONF_ERROR;
        }

        value[last].data[value[last].len] = '\0';
        value[last].len++;

        if (ngx_http_rewrite_value(cf, lcf, &value[last]) != NGX_CONF_OK) {
            return NGX_CONF_ERROR;
        }

        fop = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                          sizeof(ngx_http_script_file_code_t));
        if (fop == NULL) {
            return NGX_CONF_ERROR;
        }

        fop->code = ngx_http_script_file_code;

        if (p[1] == 'f') {
            fop->op = ngx_http_script_file_plain;
            return NGX_CONF_OK;
        }

        if (p[1] == 'd') {
            fop->op = ngx_http_script_file_dir;
            return NGX_CONF_OK;
        }

        if (p[1] == 'e') {
            fop->op = ngx_http_script_file_exists;
            return NGX_CONF_OK;
        }

        if (p[1] == 'x') {
            fop->op = ngx_http_script_file_exec;
            return NGX_CONF_OK;
        }

        if (p[0] == '!') {
            if (p[2] == 'f') {
                fop->op = ngx_http_script_file_not_plain;
                return NGX_CONF_OK;
            }

            if (p[2] == 'd') {
                fop->op = ngx_http_script_file_not_dir;
                return NGX_CONF_OK;
            }

            if (p[2] == 'e') {
                fop->op = ngx_http_script_file_not_exists;
                return NGX_CONF_OK;
            }

            if (p[2] == 'x') {
                fop->op = ngx_http_script_file_not_exec;
                return NGX_CONF_OK;
            }
        }

        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid condition \"%V\"", &value[cur]);
        return NGX_CONF_ERROR;
    }

    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                       "invalid condition \"%V\"", &value[cur]);

    return NGX_CONF_ERROR;
}


static char *
ngx_http_rewrite_variable(ngx_conf_t *cf, ngx_http_rewrite_loc_conf_t *lcf,
    ngx_str_t *value)
{
    ngx_int_t                    index;
    ngx_http_script_var_code_t  *var_code;

    value->len--;
    value->data++;

    index = ngx_http_get_variable_index(cf, value);

    if (index == NGX_ERROR) {
        return NGX_CONF_ERROR;
    }

    var_code = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                          sizeof(ngx_http_script_var_code_t));
    if (var_code == NULL) {
        return NGX_CONF_ERROR;
    }

    var_code->code = ngx_http_script_var_code;
    var_code->index = index;

    return NGX_CONF_OK;
}


static char *
ngx_http_rewrite_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_rewrite_loc_conf_t  *lcf = conf;

    ngx_int_t                            index;
    ngx_str_t                           *value;
    ngx_http_variable_t                 *v;
    ngx_http_script_var_code_t          *vcode;
    ngx_http_script_var_handler_code_t  *vhcode;

    value = cf->args->elts;

    if (value[1].data[0] != '$') {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid variable name \"%V\"", &value[1]);
        return NGX_CONF_ERROR;
    }

    value[1].len--;
    value[1].data++;

    v = ngx_http_add_variable(cf, &value[1], NGX_HTTP_VAR_CHANGEABLE);
    if (v == NULL) {
        return NGX_CONF_ERROR;
    }

    index = ngx_http_get_variable_index(cf, &value[1]);
    if (index == NGX_ERROR) {
        return NGX_CONF_ERROR;
    }

    if (v->get_handler == NULL
        && ngx_strncasecmp(value[1].data, (u_char *) "http_", 5) != 0
        && ngx_strncasecmp(value[1].data, (u_char *) "sent_http_", 10) != 0
        && ngx_strncasecmp(value[1].data, (u_char *) "upstream_http_", 14) != 0)
    {
        v->get_handler = ngx_http_rewrite_var;
        v->data = index;
    }

    if (ngx_http_rewrite_value(cf, lcf, &value[2]) != NGX_CONF_OK) {
        return NGX_CONF_ERROR;
    }

    if (v->set_handler) {
        vhcode = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                   sizeof(ngx_http_script_var_handler_code_t));
        if (vhcode == NULL) {
            return NGX_CONF_ERROR;
        }

        vhcode->code = ngx_http_script_var_set_handler_code;
        vhcode->handler = v->set_handler;
        vhcode->data = v->data;

        return NGX_CONF_OK;
    }

    vcode = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                       sizeof(ngx_http_script_var_code_t));
    if (vcode == NULL) {
        return NGX_CONF_ERROR;
    }

    vcode->code = ngx_http_script_set_var_code;
    vcode->index = (uintptr_t) index;

    return NGX_CONF_OK;
}


static char *
ngx_http_rewrite_value(ngx_conf_t *cf, ngx_http_rewrite_loc_conf_t *lcf,
    ngx_str_t *value)
{
    ngx_int_t                              n;
    ngx_http_script_compile_t              sc;
    ngx_http_script_value_code_t          *val;
    ngx_http_script_complex_value_code_t  *complex;

    n = ngx_http_script_variables_count(value);

    if (n == 0) {
        val = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                         sizeof(ngx_http_script_value_code_t));
        if (val == NULL) {
            return NGX_CONF_ERROR;
        }

        n = ngx_atoi(value->data, value->len);

        if (n == NGX_ERROR) {
            n = 0;
        }

        val->code = ngx_http_script_value_code;
        val->value = (uintptr_t) n;
        val->text_len = (uintptr_t) value->len;
        val->text_data = (uintptr_t) value->data;

        return NGX_CONF_OK;
    }

    complex = ngx_http_script_start_code(cf->pool, &lcf->codes,
                                 sizeof(ngx_http_script_complex_value_code_t));
    if (complex == NULL) {
        return NGX_CONF_ERROR;
    }

    complex->code = ngx_http_script_complex_value_code;
    complex->lengths = NULL;

    ngx_memzero(&sc, sizeof(ngx_http_script_compile_t));

    sc.cf = cf;
    sc.source = value;
    sc.lengths = &complex->lengths;
    sc.values = &lcf->codes;
    sc.variables = n;
    sc.complete_lengths = 1;

    if (ngx_http_script_compile(&sc) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}