view src/http/ngx_http_script.c @ 9203:0de20f43db25

Fixed request termination with AIO and subrequests (ticket #2555). When a request was terminated due to an error via ngx_http_terminate_request() while an AIO operation was running in a subrequest, various issues were observed. This happened because ngx_http_request_finalizer() was only set in the subrequest where ngx_http_terminate_request() was called, but not in the subrequest where the AIO operation was running. After completion of the AIO operation normal processing of the subrequest was resumed, leading to issues. In particular, in case of the upstream module, termination of the request called upstream cleanup, which closed the upstream connection. Attempts to further work with the upstream connection after AIO operation completion resulted in segfaults in ngx_ssl_recv(), "readv() failed (9: Bad file descriptor) while reading upstream" errors, or socket leaks. In ticket #2555, issues were observed with the following configuration with cache background update (with thread writing instrumented to introduce a delay, when a client closes the connection during an update): location = /background-and-aio-write { proxy_pass ... proxy_cache one; proxy_cache_valid 200 1s; proxy_cache_background_update on; proxy_cache_use_stale updating; aio threads; aio_write on; limit_rate 1000; } Similarly, the same issue can be seen with SSI, and can be caused by errors in subrequests, such as in the following configuration (where "/proxy" uses AIO, and "/sleep" returns 444 after some delay, causing request termination): location = /ssi-active-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/proxy" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Or the same with both AIO operation and the error in non-active subrequests (which needs slightly different handling, see below): location = /ssi-non-active-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static" --> <!--#include virtual="/proxy" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Similarly, issues can be observed with just static files. However, with static files potential impact is limited due to timeout safeguards in ngx_http_writer(), and the fact that c->error is set during request termination. In a simple configuration with an AIO operation in the active subrequest, such as in the following configuration, the connection is closed right after completion of the AIO operation anyway, since ngx_http_writer() tries to write to the connection and fails due to c->error set: location = /ssi-active-static-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static-aio" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } In the following configuration, with an AIO operation in a non-active subrequest, the connection is closed only after send_timeout expires: location = /ssi-non-active-static-boom { ssi on; ssi_types *; return 200 ' <!--#include virtual="/static" --> <!--#include virtual="/static-aio" --> <!--#include virtual="/sleep" --> '; limit_rate 1000; } Fix is to introduce r->main->terminated flag, which is to be checked by AIO event handlers when the r->main->blocked counter is decremented. When the flag is set, handlers are expected to wake up the connection instead of the subrequest (which might be already cleaned up). Additionally, now ngx_http_request_finalizer() is always set in the active subrequest, so waking up the connection properly finalizes the request even if termination happened in a non-active subrequest.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 30 Jan 2024 03:20:05 +0300
parents d26db4f82d7d
children
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>


static ngx_int_t ngx_http_script_init_arrays(ngx_http_script_compile_t *sc);
static ngx_int_t ngx_http_script_done(ngx_http_script_compile_t *sc);
static ngx_int_t ngx_http_script_add_copy_code(ngx_http_script_compile_t *sc,
    ngx_str_t *value, ngx_uint_t last);
static ngx_int_t ngx_http_script_add_var_code(ngx_http_script_compile_t *sc,
    ngx_str_t *name);
static ngx_int_t ngx_http_script_add_args_code(ngx_http_script_compile_t *sc);
#if (NGX_PCRE)
static ngx_int_t ngx_http_script_add_capture_code(ngx_http_script_compile_t *sc,
    ngx_uint_t n);
#endif
static ngx_int_t
    ngx_http_script_add_full_name_code(ngx_http_script_compile_t *sc);
static size_t ngx_http_script_full_name_len_code(ngx_http_script_engine_t *e);
static void ngx_http_script_full_name_code(ngx_http_script_engine_t *e);


#define ngx_http_script_exit  (u_char *) &ngx_http_script_exit_code

static uintptr_t ngx_http_script_exit_code = (uintptr_t) NULL;


void
ngx_http_script_flush_complex_value(ngx_http_request_t *r,
    ngx_http_complex_value_t *val)
{
    ngx_uint_t *index;

    index = val->flushes;

    if (index) {
        while (*index != (ngx_uint_t) -1) {

            if (r->variables[*index].no_cacheable) {
                r->variables[*index].valid = 0;
                r->variables[*index].not_found = 0;
            }

            index++;
        }
    }
}


ngx_int_t
ngx_http_complex_value(ngx_http_request_t *r, ngx_http_complex_value_t *val,
    ngx_str_t *value)
{
    size_t                        len;
    ngx_http_script_code_pt       code;
    ngx_http_script_len_code_pt   lcode;
    ngx_http_script_engine_t      e;

    if (val->lengths == NULL) {
        *value = val->value;
        return NGX_OK;
    }

    ngx_http_script_flush_complex_value(r, val);

    ngx_memzero(&e, sizeof(ngx_http_script_engine_t));

    e.ip = val->lengths;
    e.request = r;
    e.flushed = 1;

    len = 0;

    while (*(uintptr_t *) e.ip) {
        lcode = *(ngx_http_script_len_code_pt *) e.ip;
        len += lcode(&e);
    }

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

    e.ip = val->values;
    e.pos = value->data;
    e.buf = *value;

    while (*(uintptr_t *) e.ip) {
        code = *(ngx_http_script_code_pt *) e.ip;
        code((ngx_http_script_engine_t *) &e);
    }

    *value = e.buf;

    return NGX_OK;
}


size_t
ngx_http_complex_value_size(ngx_http_request_t *r,
    ngx_http_complex_value_t *val, size_t default_value)
{
    size_t     size;
    ngx_str_t  value;

    if (val == NULL) {
        return default_value;
    }

    if (val->lengths == NULL) {
        return val->u.size;
    }

    if (ngx_http_complex_value(r, val, &value) != NGX_OK) {
        return default_value;
    }

    size = ngx_parse_size(&value);

    if (size == (size_t) NGX_ERROR) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "invalid size \"%V\"", &value);
        return default_value;
    }

    return size;
}


ngx_int_t
ngx_http_compile_complex_value(ngx_http_compile_complex_value_t *ccv)
{
    ngx_str_t                  *v;
    ngx_uint_t                  i, n, nv, nc;
    ngx_array_t                 flushes, lengths, values, *pf, *pl, *pv;
    ngx_http_script_compile_t   sc;

    v = ccv->value;

    nv = 0;
    nc = 0;

    for (i = 0; i < v->len; i++) {
        if (v->data[i] == '$') {
            if (v->data[i + 1] >= '1' && v->data[i + 1] <= '9') {
                nc++;

            } else {
                nv++;
            }
        }
    }

    if ((v->len == 0 || v->data[0] != '$')
        && (ccv->conf_prefix || ccv->root_prefix))
    {
        if (ngx_conf_full_name(ccv->cf->cycle, v, ccv->conf_prefix) != NGX_OK) {
            return NGX_ERROR;
        }

        ccv->conf_prefix = 0;
        ccv->root_prefix = 0;
    }

    ccv->complex_value->value = *v;
    ccv->complex_value->flushes = NULL;
    ccv->complex_value->lengths = NULL;
    ccv->complex_value->values = NULL;

    if (nv == 0 && nc == 0) {
        return NGX_OK;
    }

    n = nv + 1;

    if (ngx_array_init(&flushes, ccv->cf->pool, n, sizeof(ngx_uint_t))
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    n = nv * (2 * sizeof(ngx_http_script_copy_code_t)
                  + sizeof(ngx_http_script_var_code_t))
        + sizeof(uintptr_t);

    if (ngx_array_init(&lengths, ccv->cf->pool, n, 1) != NGX_OK) {
        return NGX_ERROR;
    }

    n = (nv * (2 * sizeof(ngx_http_script_copy_code_t)
                   + sizeof(ngx_http_script_var_code_t))
                + sizeof(uintptr_t)
                + v->len
                + sizeof(uintptr_t) - 1)
            & ~(sizeof(uintptr_t) - 1);

    if (ngx_array_init(&values, ccv->cf->pool, n, 1) != NGX_OK) {
        return NGX_ERROR;
    }

    pf = &flushes;
    pl = &lengths;
    pv = &values;

    ngx_memzero(&sc, sizeof(ngx_http_script_compile_t));

    sc.cf = ccv->cf;
    sc.source = v;
    sc.flushes = &pf;
    sc.lengths = &pl;
    sc.values = &pv;
    sc.complete_lengths = 1;
    sc.complete_values = 1;
    sc.zero = ccv->zero;
    sc.conf_prefix = ccv->conf_prefix;
    sc.root_prefix = ccv->root_prefix;

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

    if (flushes.nelts) {
        ccv->complex_value->flushes = flushes.elts;
        ccv->complex_value->flushes[flushes.nelts] = (ngx_uint_t) -1;
    }

    ccv->complex_value->lengths = lengths.elts;
    ccv->complex_value->values = values.elts;

    return NGX_OK;
}


char *
ngx_http_set_complex_value_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_str_t                          *value;
    ngx_http_complex_value_t          **cv;
    ngx_http_compile_complex_value_t    ccv;

    cv = (ngx_http_complex_value_t **) (p + cmd->offset);

    if (*cv != NGX_CONF_UNSET_PTR && *cv != NULL) {
        return "is duplicate";
    }

    *cv = ngx_palloc(cf->pool, sizeof(ngx_http_complex_value_t));
    if (*cv == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = &value[1];
    ccv.complex_value = *cv;

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

    return NGX_CONF_OK;
}


char *
ngx_http_set_complex_value_zero_slot(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf)
{
    char  *p = conf;

    ngx_str_t                          *value;
    ngx_http_complex_value_t          **cv;
    ngx_http_compile_complex_value_t    ccv;

    cv = (ngx_http_complex_value_t **) (p + cmd->offset);

    if (*cv != NGX_CONF_UNSET_PTR) {
        return "is duplicate";
    }

    *cv = ngx_palloc(cf->pool, sizeof(ngx_http_complex_value_t));
    if (*cv == NULL) {
        return NGX_CONF_ERROR;
    }

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));

    ccv.cf = cf;
    ccv.value = &value[1];
    ccv.complex_value = *cv;
    ccv.zero = 1;

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

    return NGX_CONF_OK;
}


char *
ngx_http_set_complex_value_size_slot(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf)
{
    char  *p = conf;

    char                      *rv;
    ngx_http_complex_value_t  *cv;

    rv = ngx_http_set_complex_value_slot(cf, cmd, conf);

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

    cv = *(ngx_http_complex_value_t **) (p + cmd->offset);

    if (cv->lengths) {
        return NGX_CONF_OK;
    }

    cv->u.size = ngx_parse_size(&cv->value);
    if (cv->u.size == (size_t) NGX_ERROR) {
        return "invalid value";
    }

    return NGX_CONF_OK;
}


ngx_int_t
ngx_http_test_predicates(ngx_http_request_t *r, ngx_array_t *predicates)
{
    ngx_str_t                  val;
    ngx_uint_t                 i;
    ngx_http_complex_value_t  *cv;

    if (predicates == NULL) {
        return NGX_OK;
    }

    cv = predicates->elts;

    for (i = 0; i < predicates->nelts; i++) {
        if (ngx_http_complex_value(r, &cv[i], &val) != NGX_OK) {
            return NGX_ERROR;
        }

        if (val.len && (val.len != 1 || val.data[0] != '0')) {
            return NGX_DECLINED;
        }
    }

    return NGX_OK;
}


ngx_int_t
ngx_http_test_required_predicates(ngx_http_request_t *r,
    ngx_array_t *predicates)
{
    ngx_str_t                  val;
    ngx_uint_t                 i;
    ngx_http_complex_value_t  *cv;

    if (predicates == NULL) {
        return NGX_OK;
    }

    cv = predicates->elts;

    for (i = 0; i < predicates->nelts; i++) {
        if (ngx_http_complex_value(r, &cv[i], &val) != NGX_OK) {
            return NGX_ERROR;
        }

        if (val.len == 0 || (val.len == 1 && val.data[0] == '0')) {
            return NGX_DECLINED;
        }
    }

    return NGX_OK;
}


char *
ngx_http_set_predicate_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    char  *p = conf;

    ngx_str_t                          *value;
    ngx_uint_t                          i;
    ngx_array_t                       **a;
    ngx_http_complex_value_t           *cv;
    ngx_http_compile_complex_value_t    ccv;

    a = (ngx_array_t **) (p + cmd->offset);

    if (*a == NGX_CONF_UNSET_PTR) {
        *a = ngx_array_create(cf->pool, 1, sizeof(ngx_http_complex_value_t));
        if (*a == NULL) {
            return NGX_CONF_ERROR;
        }
    }

    value = cf->args->elts;

    for (i = 1; i < cf->args->nelts; i++) {
        cv = ngx_array_push(*a);
        if (cv == NULL) {
            return NGX_CONF_ERROR;
        }

        ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));

        ccv.cf = cf;
        ccv.value = &value[i];
        ccv.complex_value = cv;

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

    return NGX_CONF_OK;
}


ngx_uint_t
ngx_http_script_variables_count(ngx_str_t *value)
{
    ngx_uint_t  i, n;

    for (n = 0, i = 0; i < value->len; i++) {
        if (value->data[i] == '$') {
            n++;
        }
    }

    return n;
}


ngx_int_t
ngx_http_script_compile(ngx_http_script_compile_t *sc)
{
    u_char       ch;
    ngx_str_t    name;
    ngx_uint_t   i, bracket;

    if (ngx_http_script_init_arrays(sc) != NGX_OK) {
        return NGX_ERROR;
    }

    for (i = 0; i < sc->source->len; /* void */ ) {

        name.len = 0;

        if (sc->source->data[i] == '$') {

            if (++i == sc->source->len) {
                goto invalid_variable;
            }

            if (sc->source->data[i] >= '1' && sc->source->data[i] <= '9') {
#if (NGX_PCRE)
                ngx_uint_t  n;

                n = sc->source->data[i] - '0';

                if (sc->captures_mask & ((ngx_uint_t) 1 << n)) {
                    sc->dup_capture = 1;
                }

                sc->captures_mask |= (ngx_uint_t) 1 << n;

                if (ngx_http_script_add_capture_code(sc, n) != NGX_OK) {
                    return NGX_ERROR;
                }

                i++;

                continue;
#else
                ngx_conf_log_error(NGX_LOG_EMERG, sc->cf, 0,
                                   "using variable \"$%c\" requires "
                                   "PCRE library", sc->source->data[i]);
                return NGX_ERROR;
#endif
            }

            if (sc->source->data[i] == '{') {
                bracket = 1;

                if (++i == sc->source->len) {
                    goto invalid_variable;
                }

                name.data = &sc->source->data[i];

            } else {
                bracket = 0;
                name.data = &sc->source->data[i];
            }

            for ( /* void */ ; i < sc->source->len; i++, name.len++) {
                ch = sc->source->data[i];

                if (ch == '}' && bracket) {
                    i++;
                    bracket = 0;
                    break;
                }

                if ((ch >= 'A' && ch <= 'Z')
                    || (ch >= 'a' && ch <= 'z')
                    || (ch >= '0' && ch <= '9')
                    || ch == '_')
                {
                    continue;
                }

                break;
            }

            if (bracket) {
                ngx_conf_log_error(NGX_LOG_EMERG, sc->cf, 0,
                                   "the closing bracket in \"%V\" "
                                   "variable is missing", &name);
                return NGX_ERROR;
            }

            if (name.len == 0) {
                goto invalid_variable;
            }

            sc->variables++;

            if (ngx_http_script_add_var_code(sc, &name) != NGX_OK) {
                return NGX_ERROR;
            }

            continue;
        }

        if (sc->source->data[i] == '?' && sc->compile_args) {
            sc->args = 1;
            sc->compile_args = 0;

            if (ngx_http_script_add_args_code(sc) != NGX_OK) {
                return NGX_ERROR;
            }

            i++;

            continue;
        }

        name.data = &sc->source->data[i];

        while (i < sc->source->len) {

            if (sc->source->data[i] == '$') {
                break;
            }

            if (sc->source->data[i] == '?') {

                sc->args = 1;

                if (sc->compile_args) {
                    break;
                }
            }

            i++;
            name.len++;
        }

        sc->size += name.len;

        if (ngx_http_script_add_copy_code(sc, &name, (i == sc->source->len))
            != NGX_OK)
        {
            return NGX_ERROR;
        }
    }

    return ngx_http_script_done(sc);

invalid_variable:

    ngx_conf_log_error(NGX_LOG_EMERG, sc->cf, 0, "invalid variable name");

    return NGX_ERROR;
}


u_char *
ngx_http_script_run(ngx_http_request_t *r, ngx_str_t *value,
    void *code_lengths, size_t len, void *code_values)
{
    ngx_uint_t                    i;
    ngx_http_script_code_pt       code;
    ngx_http_script_len_code_pt   lcode;
    ngx_http_script_engine_t      e;
    ngx_http_core_main_conf_t    *cmcf;

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    for (i = 0; i < cmcf->variables.nelts; i++) {
        if (r->variables[i].no_cacheable) {
            r->variables[i].valid = 0;
            r->variables[i].not_found = 0;
        }
    }

    ngx_memzero(&e, sizeof(ngx_http_script_engine_t));

    e.ip = code_lengths;
    e.request = r;
    e.flushed = 1;

    while (*(uintptr_t *) e.ip) {
        lcode = *(ngx_http_script_len_code_pt *) e.ip;
        len += lcode(&e);
    }


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

    e.ip = code_values;
    e.pos = value->data;

    while (*(uintptr_t *) e.ip) {
        code = *(ngx_http_script_code_pt *) e.ip;
        code((ngx_http_script_engine_t *) &e);
    }

    return e.pos;
}


void
ngx_http_script_flush_no_cacheable_variables(ngx_http_request_t *r,
    ngx_array_t *indices)
{
    ngx_uint_t  n, *index;

    if (indices) {
        index = indices->elts;
        for (n = 0; n < indices->nelts; n++) {
            if (r->variables[index[n]].no_cacheable) {
                r->variables[index[n]].valid = 0;
                r->variables[index[n]].not_found = 0;
            }
        }
    }
}


static ngx_int_t
ngx_http_script_init_arrays(ngx_http_script_compile_t *sc)
{
    ngx_uint_t   n;

    if (sc->flushes && *sc->flushes == NULL) {
        n = sc->variables ? sc->variables : 1;
        *sc->flushes = ngx_array_create(sc->cf->pool, n, sizeof(ngx_uint_t));
        if (*sc->flushes == NULL) {
            return NGX_ERROR;
        }
    }

    if (*sc->lengths == NULL) {
        n = sc->variables * (2 * sizeof(ngx_http_script_copy_code_t)
                             + sizeof(ngx_http_script_var_code_t))
            + sizeof(uintptr_t);

        *sc->lengths = ngx_array_create(sc->cf->pool, n, 1);
        if (*sc->lengths == NULL) {
            return NGX_ERROR;
        }
    }

    if (*sc->values == NULL) {
        n = (sc->variables * (2 * sizeof(ngx_http_script_copy_code_t)
                              + sizeof(ngx_http_script_var_code_t))
                + sizeof(uintptr_t)
                + sc->source->len
                + sizeof(uintptr_t) - 1)
            & ~(sizeof(uintptr_t) - 1);

        *sc->values = ngx_array_create(sc->cf->pool, n, 1);
        if (*sc->values == NULL) {
            return NGX_ERROR;
        }
    }

    sc->variables = 0;

    return NGX_OK;
}


static ngx_int_t
ngx_http_script_done(ngx_http_script_compile_t *sc)
{
    ngx_str_t    zero;
    uintptr_t   *code;

    if (sc->zero) {

        zero.len = 1;
        zero.data = (u_char *) "\0";

        if (ngx_http_script_add_copy_code(sc, &zero, 0) != NGX_OK) {
            return NGX_ERROR;
        }
    }

    if (sc->conf_prefix || sc->root_prefix) {
        if (ngx_http_script_add_full_name_code(sc) != NGX_OK) {
            return NGX_ERROR;
        }
    }

    if (sc->complete_lengths) {
        code = ngx_http_script_add_code(*sc->lengths, sizeof(uintptr_t), NULL);
        if (code == NULL) {
            return NGX_ERROR;
        }

        *code = (uintptr_t) NULL;
    }

    if (sc->complete_values) {
        code = ngx_http_script_add_code(*sc->values, sizeof(uintptr_t),
                                        &sc->main);
        if (code == NULL) {
            return NGX_ERROR;
        }

        *code = (uintptr_t) NULL;
    }

    return NGX_OK;
}


void *
ngx_http_script_start_code(ngx_pool_t *pool, ngx_array_t **codes, size_t size)
{
    if (*codes == NULL) {
        *codes = ngx_array_create(pool, 256, 1);
        if (*codes == NULL) {
            return NULL;
        }
    }

    return ngx_array_push_n(*codes, size);
}


void *
ngx_http_script_add_code(ngx_array_t *codes, size_t size, void *code)
{
    u_char  *elts, **p;
    void    *new;

    elts = codes->elts;

    new = ngx_array_push_n(codes, size);
    if (new == NULL) {
        return NULL;
    }

    if (code) {
        if (elts != codes->elts) {
            p = code;
            *p += (u_char *) codes->elts - elts;
        }
    }

    return new;
}


static ngx_int_t
ngx_http_script_add_copy_code(ngx_http_script_compile_t *sc, ngx_str_t *value,
    ngx_uint_t last)
{
    u_char                       *p;
    size_t                        size, len, zero;
    ngx_http_script_copy_code_t  *code;

    zero = (sc->zero && last);
    len = value->len + zero;

    code = ngx_http_script_add_code(*sc->lengths,
                                    sizeof(ngx_http_script_copy_code_t), NULL);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = (ngx_http_script_code_pt) (void *)
                                                 ngx_http_script_copy_len_code;
    code->len = len;

    size = (sizeof(ngx_http_script_copy_code_t) + len + sizeof(uintptr_t) - 1)
            & ~(sizeof(uintptr_t) - 1);

    code = ngx_http_script_add_code(*sc->values, size, &sc->main);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = ngx_http_script_copy_code;
    code->len = len;

    p = ngx_cpymem((u_char *) code + sizeof(ngx_http_script_copy_code_t),
                   value->data, value->len);

    if (zero) {
        *p = '\0';
        sc->zero = 0;
    }

    return NGX_OK;
}


size_t
ngx_http_script_copy_len_code(ngx_http_script_engine_t *e)
{
    ngx_http_script_copy_code_t  *code;

    code = (ngx_http_script_copy_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_copy_code_t);

    return code->len;
}


void
ngx_http_script_copy_code(ngx_http_script_engine_t *e)
{
    u_char                       *p;
    ngx_http_script_copy_code_t  *code;

    code = (ngx_http_script_copy_code_t *) e->ip;

    p = e->pos;

    if (!e->skip) {
        e->pos = ngx_copy(p, e->ip + sizeof(ngx_http_script_copy_code_t),
                          code->len);
    }

    e->ip += sizeof(ngx_http_script_copy_code_t)
          + ((code->len + sizeof(uintptr_t) - 1) & ~(sizeof(uintptr_t) - 1));

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script copy: \"%*s\"", e->pos - p, p);
}


static ngx_int_t
ngx_http_script_add_var_code(ngx_http_script_compile_t *sc, ngx_str_t *name)
{
    ngx_int_t                    index, *p;
    ngx_http_script_var_code_t  *code;

    index = ngx_http_get_variable_index(sc->cf, name);

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

    if (sc->flushes) {
        p = ngx_array_push(*sc->flushes);
        if (p == NULL) {
            return NGX_ERROR;
        }

        *p = index;
    }

    code = ngx_http_script_add_code(*sc->lengths,
                                    sizeof(ngx_http_script_var_code_t), NULL);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = (ngx_http_script_code_pt) (void *)
                                             ngx_http_script_copy_var_len_code;
    code->index = (uintptr_t) index;

    code = ngx_http_script_add_code(*sc->values,
                                    sizeof(ngx_http_script_var_code_t),
                                    &sc->main);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = ngx_http_script_copy_var_code;
    code->index = (uintptr_t) index;

    return NGX_OK;
}


size_t
ngx_http_script_copy_var_len_code(ngx_http_script_engine_t *e)
{
    ngx_http_variable_value_t   *value;
    ngx_http_script_var_code_t  *code;

    code = (ngx_http_script_var_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_var_code_t);

    if (e->flushed) {
        value = ngx_http_get_indexed_variable(e->request, code->index);

    } else {
        value = ngx_http_get_flushed_variable(e->request, code->index);
    }

    if (value && !value->not_found) {
        return value->len;
    }

    return 0;
}


void
ngx_http_script_copy_var_code(ngx_http_script_engine_t *e)
{
    u_char                      *p;
    ngx_http_variable_value_t   *value;
    ngx_http_script_var_code_t  *code;

    code = (ngx_http_script_var_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_var_code_t);

    if (!e->skip) {

        if (e->flushed) {
            value = ngx_http_get_indexed_variable(e->request, code->index);

        } else {
            value = ngx_http_get_flushed_variable(e->request, code->index);
        }

        if (value && !value->not_found) {
            p = e->pos;
            e->pos = ngx_copy(p, value->data, value->len);

            ngx_log_debug2(NGX_LOG_DEBUG_HTTP,
                           e->request->connection->log, 0,
                           "http script var: \"%*s\"", e->pos - p, p);
        }
    }
}


static ngx_int_t
ngx_http_script_add_args_code(ngx_http_script_compile_t *sc)
{
    uintptr_t   *code;

    code = ngx_http_script_add_code(*sc->lengths, sizeof(uintptr_t), NULL);
    if (code == NULL) {
        return NGX_ERROR;
    }

    *code = (uintptr_t) ngx_http_script_mark_args_code;

    code = ngx_http_script_add_code(*sc->values, sizeof(uintptr_t), &sc->main);
    if (code == NULL) {
        return NGX_ERROR;
    }

    *code = (uintptr_t) ngx_http_script_start_args_code;

    return NGX_OK;
}


size_t
ngx_http_script_mark_args_code(ngx_http_script_engine_t *e)
{
    e->is_args = 1;
    e->ip += sizeof(uintptr_t);

    return 1;
}


void
ngx_http_script_start_args_code(ngx_http_script_engine_t *e)
{
    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script args");

    e->is_args = 1;
    e->args = e->pos;
    e->ip += sizeof(uintptr_t);
}


#if (NGX_PCRE)

void
ngx_http_script_regex_start_code(ngx_http_script_engine_t *e)
{
    size_t                         len;
    ngx_int_t                      rc;
    ngx_uint_t                     n;
    ngx_http_request_t            *r;
    ngx_http_script_engine_t       le;
    ngx_http_script_len_code_pt    lcode;
    ngx_http_script_regex_code_t  *code;

    code = (ngx_http_script_regex_code_t *) e->ip;

    r = e->request;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http script regex: \"%V\"", &code->name);

    if (code->uri) {
        e->line = r->uri;
    } else {
        e->sp--;
        e->line.len = e->sp->len;
        e->line.data = e->sp->data;
    }

    rc = ngx_http_regex_exec(r, code->regex, &e->line);

    if (rc == NGX_DECLINED) {
        if (e->log || (r->connection->log->log_level & NGX_LOG_DEBUG_HTTP)) {
            ngx_log_error(NGX_LOG_NOTICE, r->connection->log, 0,
                          "\"%V\" does not match \"%V\"",
                          &code->name, &e->line);
        }

        r->ncaptures = 0;

        if (code->test) {
            if (code->negative_test) {
                e->sp->len = 1;
                e->sp->data = (u_char *) "1";

            } else {
                e->sp->len = 0;
                e->sp->data = (u_char *) "";
            }

            e->sp++;

            e->ip += sizeof(ngx_http_script_regex_code_t);
            return;
        }

        e->ip += code->next;
        return;
    }

    if (rc == NGX_ERROR) {
        e->ip = ngx_http_script_exit;
        e->status = NGX_HTTP_INTERNAL_SERVER_ERROR;
        return;
    }

    if (e->log || (r->connection->log->log_level & NGX_LOG_DEBUG_HTTP)) {
        ngx_log_error(NGX_LOG_NOTICE, r->connection->log, 0,
                      "\"%V\" matches \"%V\"", &code->name, &e->line);
    }

    if (code->test) {
        if (code->negative_test) {
            e->sp->len = 0;
            e->sp->data = (u_char *) "";

        } else {
            e->sp->len = 1;
            e->sp->data = (u_char *) "1";
        }

        e->sp++;

        e->ip += sizeof(ngx_http_script_regex_code_t);
        return;
    }

    if (code->status) {
        e->status = code->status;

        if (!code->redirect) {
            e->ip = ngx_http_script_exit;
            return;
        }
    }

    if (code->uri) {
        r->internal = 1;
        r->valid_unparsed_uri = 0;

        if (code->break_cycle) {
            r->valid_location = 0;
            r->uri_changed = 0;

        } else {
            r->uri_changed = 1;
        }
    }

    if (code->lengths == NULL) {
        e->buf.len = code->size;

        if (code->uri) {
            if (r->ncaptures && (r->quoted_uri || r->plus_in_uri)) {
                e->buf.len += 2 * ngx_escape_uri(NULL, r->uri.data, r->uri.len,
                                                 NGX_ESCAPE_ARGS);
            }
        }

        for (n = 2; n < r->ncaptures; n += 2) {
            e->buf.len += r->captures[n + 1] - r->captures[n];
        }

    } else {
        ngx_memzero(&le, sizeof(ngx_http_script_engine_t));

        le.ip = code->lengths->elts;
        le.line = e->line;
        le.request = r;
        le.quote = code->redirect;

        len = 0;

        while (*(uintptr_t *) le.ip) {
            lcode = *(ngx_http_script_len_code_pt *) le.ip;
            len += lcode(&le);
        }

        e->buf.len = len;
    }

    if (code->add_args && r->args.len) {
        e->buf.len += r->args.len + 1;
    }

    e->buf.data = ngx_pnalloc(r->pool, e->buf.len);
    if (e->buf.data == NULL) {
        e->ip = ngx_http_script_exit;
        e->status = NGX_HTTP_INTERNAL_SERVER_ERROR;
        return;
    }

    e->quote = code->redirect;

    e->pos = e->buf.data;

    e->ip += sizeof(ngx_http_script_regex_code_t);
}


void
ngx_http_script_regex_end_code(ngx_http_script_engine_t *e)
{
    u_char                            *dst, *src;
    ngx_http_request_t                *r;
    ngx_http_script_regex_end_code_t  *code;

    code = (ngx_http_script_regex_end_code_t *) e->ip;

    r = e->request;

    e->quote = 0;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http script regex end");

    if (code->redirect) {

        dst = e->buf.data;
        src = e->buf.data;

        ngx_unescape_uri(&dst, &src, e->pos - e->buf.data,
                         NGX_UNESCAPE_REDIRECT);

        if (src < e->pos) {
            dst = ngx_movemem(dst, src, e->pos - src);
        }

        e->pos = dst;

        if (code->add_args && r->args.len) {
            *e->pos++ = (u_char) (code->args ? '&' : '?');
            e->pos = ngx_copy(e->pos, r->args.data, r->args.len);
        }

        e->buf.len = e->pos - e->buf.data;

        if (e->log || (r->connection->log->log_level & NGX_LOG_DEBUG_HTTP)) {
            ngx_log_error(NGX_LOG_NOTICE, r->connection->log, 0,
                          "rewritten redirect: \"%V\"", &e->buf);
        }

        ngx_http_clear_location(r);

        r->headers_out.location = ngx_list_push(&r->headers_out.headers);
        if (r->headers_out.location == NULL) {
            e->ip = ngx_http_script_exit;
            e->status = NGX_HTTP_INTERNAL_SERVER_ERROR;
            return;
        }

        r->headers_out.location->hash = 1;
        r->headers_out.location->next = NULL;
        ngx_str_set(&r->headers_out.location->key, "Location");
        r->headers_out.location->value = e->buf;

        e->ip += sizeof(ngx_http_script_regex_end_code_t);
        return;
    }

    if (e->args) {
        e->buf.len = e->args - e->buf.data;

        if (code->add_args && r->args.len) {
            *e->pos++ = '&';
            e->pos = ngx_copy(e->pos, r->args.data, r->args.len);
        }

        r->args.len = e->pos - e->args;
        r->args.data = e->args;

        e->args = NULL;

    } else {
        e->buf.len = e->pos - e->buf.data;

        if (!code->add_args) {
            r->args.len = 0;
        }
    }

    if (e->log || (r->connection->log->log_level & NGX_LOG_DEBUG_HTTP)) {
        ngx_log_error(NGX_LOG_NOTICE, r->connection->log, 0,
                      "rewritten data: \"%V\", args: \"%V\"",
                      &e->buf, &r->args);
    }

    if (code->uri) {
        r->uri = e->buf;

        if (r->uri.len == 0) {
            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                          "the rewritten URI has a zero length");
            e->ip = ngx_http_script_exit;
            e->status = NGX_HTTP_INTERNAL_SERVER_ERROR;
            return;
        }

        ngx_http_set_exten(r);
    }

    e->ip += sizeof(ngx_http_script_regex_end_code_t);
}


static ngx_int_t
ngx_http_script_add_capture_code(ngx_http_script_compile_t *sc, ngx_uint_t n)
{
    ngx_http_script_copy_capture_code_t  *code;

    code = ngx_http_script_add_code(*sc->lengths,
                                    sizeof(ngx_http_script_copy_capture_code_t),
                                    NULL);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = (ngx_http_script_code_pt) (void *)
                                         ngx_http_script_copy_capture_len_code;
    code->n = 2 * n;


    code = ngx_http_script_add_code(*sc->values,
                                    sizeof(ngx_http_script_copy_capture_code_t),
                                    &sc->main);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = ngx_http_script_copy_capture_code;
    code->n = 2 * n;

    if (sc->ncaptures < n) {
        sc->ncaptures = n;
    }

    return NGX_OK;
}


size_t
ngx_http_script_copy_capture_len_code(ngx_http_script_engine_t *e)
{
    int                                  *cap;
    u_char                               *p;
    ngx_uint_t                            n;
    ngx_http_request_t                   *r;
    ngx_http_script_copy_capture_code_t  *code;

    r = e->request;

    code = (ngx_http_script_copy_capture_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_copy_capture_code_t);

    n = code->n;

    if (n < r->ncaptures) {

        cap = r->captures;

        if ((e->is_args || e->quote)
            && (e->request->quoted_uri || e->request->plus_in_uri))
        {
            p = r->captures_data;

            return cap[n + 1] - cap[n]
                   + 2 * ngx_escape_uri(NULL, &p[cap[n]], cap[n + 1] - cap[n],
                                        NGX_ESCAPE_ARGS);
        } else {
            return cap[n + 1] - cap[n];
        }
    }

    return 0;
}


void
ngx_http_script_copy_capture_code(ngx_http_script_engine_t *e)
{
    int                                  *cap;
    u_char                               *p, *pos;
    ngx_uint_t                            n;
    ngx_http_request_t                   *r;
    ngx_http_script_copy_capture_code_t  *code;

    r = e->request;

    code = (ngx_http_script_copy_capture_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_copy_capture_code_t);

    n = code->n;

    pos = e->pos;

    if (n < r->ncaptures) {

        cap = r->captures;
        p = r->captures_data;

        if ((e->is_args || e->quote)
            && (e->request->quoted_uri || e->request->plus_in_uri))
        {
            e->pos = (u_char *) ngx_escape_uri(pos, &p[cap[n]],
                                               cap[n + 1] - cap[n],
                                               NGX_ESCAPE_ARGS);
        } else {
            e->pos = ngx_copy(pos, &p[cap[n]], cap[n + 1] - cap[n]);
        }
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script capture: \"%*s\"", e->pos - pos, pos);
}

#endif


static ngx_int_t
ngx_http_script_add_full_name_code(ngx_http_script_compile_t *sc)
{
    ngx_http_script_full_name_code_t  *code;

    code = ngx_http_script_add_code(*sc->lengths,
                                    sizeof(ngx_http_script_full_name_code_t),
                                    NULL);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = (ngx_http_script_code_pt) (void *)
                                            ngx_http_script_full_name_len_code;
    code->conf_prefix = sc->conf_prefix;

    code = ngx_http_script_add_code(*sc->values,
                                    sizeof(ngx_http_script_full_name_code_t),
                                    &sc->main);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = ngx_http_script_full_name_code;
    code->conf_prefix = sc->conf_prefix;

    return NGX_OK;
}


static size_t
ngx_http_script_full_name_len_code(ngx_http_script_engine_t *e)
{
    ngx_http_script_full_name_code_t  *code;

    code = (ngx_http_script_full_name_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_full_name_code_t);

    return code->conf_prefix ? ngx_cycle->conf_prefix.len:
                               ngx_cycle->prefix.len;
}


static void
ngx_http_script_full_name_code(ngx_http_script_engine_t *e)
{
    ngx_http_script_full_name_code_t  *code;

    ngx_str_t  value, *prefix;

    code = (ngx_http_script_full_name_code_t *) e->ip;

    value.data = e->buf.data;
    value.len = e->pos - e->buf.data;

    prefix = code->conf_prefix ? (ngx_str_t *) &ngx_cycle->conf_prefix:
                                 (ngx_str_t *) &ngx_cycle->prefix;

    if (ngx_get_full_name(e->request->pool, prefix, &value) != NGX_OK) {
        e->ip = ngx_http_script_exit;
        e->status = NGX_HTTP_INTERNAL_SERVER_ERROR;
        return;
    }

    e->buf = value;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script fullname: \"%V\"", &value);

    e->ip += sizeof(ngx_http_script_full_name_code_t);
}


void
ngx_http_script_return_code(ngx_http_script_engine_t *e)
{
    ngx_http_script_return_code_t  *code;

    code = (ngx_http_script_return_code_t *) e->ip;

    if (code->status < NGX_HTTP_BAD_REQUEST
        || code->text.value.len
        || code->text.lengths)
    {
        e->status = ngx_http_send_response(e->request, code->status, NULL,
                                           &code->text);
    } else {
        e->status = code->status;
    }

    e->ip = ngx_http_script_exit;
}


void
ngx_http_script_break_code(ngx_http_script_engine_t *e)
{
    ngx_http_request_t  *r;

    r = e->request;

    if (r->uri_changed) {
        r->valid_location = 0;
        r->uri_changed = 0;
    }

    e->ip = ngx_http_script_exit;
}


void
ngx_http_script_if_code(ngx_http_script_engine_t *e)
{
    ngx_http_script_if_code_t  *code;

    code = (ngx_http_script_if_code_t *) e->ip;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script if");

    e->sp--;

    if (e->sp->len && (e->sp->len != 1 || e->sp->data[0] != '0')) {
        if (code->loc_conf) {
            e->request->loc_conf = code->loc_conf;
            ngx_http_update_location_config(e->request);
        }

        e->ip += sizeof(ngx_http_script_if_code_t);
        return;
    }

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script if: false");

    e->ip += code->next;
}


void
ngx_http_script_equal_code(ngx_http_script_engine_t *e)
{
    ngx_http_variable_value_t  *val, *res;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script equal");

    e->sp--;
    val = e->sp;
    res = e->sp - 1;

    e->ip += sizeof(uintptr_t);

    if (val->len == res->len
        && ngx_strncmp(val->data, res->data, res->len) == 0)
    {
        *res = ngx_http_variable_true_value;
        return;
    }

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script equal: no");

    *res = ngx_http_variable_null_value;
}


void
ngx_http_script_not_equal_code(ngx_http_script_engine_t *e)
{
    ngx_http_variable_value_t  *val, *res;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script not equal");

    e->sp--;
    val = e->sp;
    res = e->sp - 1;

    e->ip += sizeof(uintptr_t);

    if (val->len == res->len
        && ngx_strncmp(val->data, res->data, res->len) == 0)
    {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                       "http script not equal: no");

        *res = ngx_http_variable_null_value;
        return;
    }

    *res = ngx_http_variable_true_value;
}


void
ngx_http_script_file_code(ngx_http_script_engine_t *e)
{
    ngx_str_t                     path;
    ngx_http_request_t           *r;
    ngx_open_file_info_t          of;
    ngx_http_core_loc_conf_t     *clcf;
    ngx_http_variable_value_t    *value;
    ngx_http_script_file_code_t  *code;

    value = e->sp - 1;

    code = (ngx_http_script_file_code_t *) e->ip;
    e->ip += sizeof(ngx_http_script_file_code_t);

    path.len = value->len - 1;
    path.data = value->data;

    r = e->request;

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http script file op %p \"%V\"", (void *) code->op, &path);

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    ngx_memzero(&of, sizeof(ngx_open_file_info_t));

    of.read_ahead = clcf->read_ahead;
    of.directio = clcf->directio;
    of.valid = clcf->open_file_cache_valid;
    of.min_uses = clcf->open_file_cache_min_uses;
    of.test_only = 1;
    of.errors = clcf->open_file_cache_errors;
    of.events = clcf->open_file_cache_events;

    if (ngx_http_set_disable_symlinks(r, clcf, &path, &of) != NGX_OK) {
        e->ip = ngx_http_script_exit;
        e->status = NGX_HTTP_INTERNAL_SERVER_ERROR;
        return;
    }

    if (ngx_open_cached_file(clcf->open_file_cache, &path, &of, r->pool)
        != NGX_OK)
    {
        if (of.err == 0) {
            e->ip = ngx_http_script_exit;
            e->status = NGX_HTTP_INTERNAL_SERVER_ERROR;
            return;
        }

        if (of.err != NGX_ENOENT
            && of.err != NGX_ENOTDIR
            && of.err != NGX_ENAMETOOLONG)
        {
            ngx_log_error(NGX_LOG_CRIT, r->connection->log, of.err,
                          "%s \"%s\" failed", of.failed, value->data);
        }

        switch (code->op) {

        case ngx_http_script_file_plain:
        case ngx_http_script_file_dir:
        case ngx_http_script_file_exists:
        case ngx_http_script_file_exec:
             goto false_value;

        case ngx_http_script_file_not_plain:
        case ngx_http_script_file_not_dir:
        case ngx_http_script_file_not_exists:
        case ngx_http_script_file_not_exec:
             goto true_value;
        }

        goto false_value;
    }

    switch (code->op) {
    case ngx_http_script_file_plain:
        if (of.is_file) {
             goto true_value;
        }
        goto false_value;

    case ngx_http_script_file_not_plain:
        if (of.is_file) {
            goto false_value;
        }
        goto true_value;

    case ngx_http_script_file_dir:
        if (of.is_dir) {
             goto true_value;
        }
        goto false_value;

    case ngx_http_script_file_not_dir:
        if (of.is_dir) {
            goto false_value;
        }
        goto true_value;

    case ngx_http_script_file_exists:
        if (of.is_file || of.is_dir || of.is_link) {
             goto true_value;
        }
        goto false_value;

    case ngx_http_script_file_not_exists:
        if (of.is_file || of.is_dir || of.is_link) {
            goto false_value;
        }
        goto true_value;

    case ngx_http_script_file_exec:
        if (of.is_exec) {
             goto true_value;
        }
        goto false_value;

    case ngx_http_script_file_not_exec:
        if (of.is_exec) {
            goto false_value;
        }
        goto true_value;
    }

false_value:

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http script file op false");

    *value = ngx_http_variable_null_value;
    return;

true_value:

    *value = ngx_http_variable_true_value;
    return;
}


void
ngx_http_script_complex_value_code(ngx_http_script_engine_t *e)
{
    size_t                                 len;
    ngx_http_script_engine_t               le;
    ngx_http_script_len_code_pt            lcode;
    ngx_http_script_complex_value_code_t  *code;

    code = (ngx_http_script_complex_value_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_complex_value_code_t);

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script complex value");

    ngx_memzero(&le, sizeof(ngx_http_script_engine_t));

    le.ip = code->lengths->elts;
    le.line = e->line;
    le.request = e->request;
    le.quote = e->quote;

    for (len = 0; *(uintptr_t *) le.ip; len += lcode(&le)) {
        lcode = *(ngx_http_script_len_code_pt *) le.ip;
    }

    e->buf.len = len;
    e->buf.data = ngx_pnalloc(e->request->pool, len);
    if (e->buf.data == NULL) {
        e->ip = ngx_http_script_exit;
        e->status = NGX_HTTP_INTERNAL_SERVER_ERROR;
        return;
    }

    e->pos = e->buf.data;

    e->sp->len = e->buf.len;
    e->sp->data = e->buf.data;
    e->sp++;
}


void
ngx_http_script_value_code(ngx_http_script_engine_t *e)
{
    ngx_http_script_value_code_t  *code;

    code = (ngx_http_script_value_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_value_code_t);

    e->sp->len = code->text_len;
    e->sp->data = (u_char *) code->text_data;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script value: \"%v\"", e->sp);

    e->sp++;
}


void
ngx_http_script_set_var_code(ngx_http_script_engine_t *e)
{
    ngx_http_request_t          *r;
    ngx_http_script_var_code_t  *code;

    code = (ngx_http_script_var_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_var_code_t);

    r = e->request;

    e->sp--;

    r->variables[code->index].len = e->sp->len;
    r->variables[code->index].valid = 1;
    r->variables[code->index].no_cacheable = 0;
    r->variables[code->index].not_found = 0;
    r->variables[code->index].data = e->sp->data;

#if (NGX_DEBUG)
    {
    ngx_http_variable_t        *v;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    v = cmcf->variables.elts;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script set $%V", &v[code->index].name);
    }
#endif
}


void
ngx_http_script_var_set_handler_code(ngx_http_script_engine_t *e)
{
    ngx_http_script_var_handler_code_t  *code;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script set var handler");

    code = (ngx_http_script_var_handler_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_var_handler_code_t);

    e->sp--;

    code->handler(e->request, e->sp, code->data);
}


void
ngx_http_script_var_code(ngx_http_script_engine_t *e)
{
    ngx_http_variable_value_t   *value;
    ngx_http_script_var_code_t  *code;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                   "http script var");

    code = (ngx_http_script_var_code_t *) e->ip;

    e->ip += sizeof(ngx_http_script_var_code_t);

    value = ngx_http_get_flushed_variable(e->request, code->index);

    if (value && !value->not_found) {
        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, e->request->connection->log, 0,
                       "http script var: \"%v\"", value);

        *e->sp = *value;
        e->sp++;

        return;
    }

    *e->sp = ngx_http_variable_null_value;
    e->sp++;
}


void
ngx_http_script_nop_code(ngx_http_script_engine_t *e)
{
    e->ip += sizeof(uintptr_t);
}