view src/stream/ngx_stream_script.c @ 7914:9cf043a5d9ca

Request body: reading body buffering in filters. If a filter wants to buffer the request body during reading (for example, to check an external scanner), it can now do so. To make it possible, the code now checks rb->last_saved (introduced in the previous change) along with rb->rest == 0. Since in HTTP/2 this requires flow control to avoid overflowing the request body buffer, so filters which need buffering have to set the rb->filter_need_buffering flag on the first filter call. (Note that each filter is expected to call the next filter, so all filters will be able set the flag if needed.)
author Maxim Dounin <mdounin@mdounin.ru>
date Sun, 29 Aug 2021 22:22:02 +0300
parents 3ab8e1e2f0f7
children
line wrap: on
line source


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


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


static ngx_int_t ngx_stream_script_init_arrays(
    ngx_stream_script_compile_t *sc);
static ngx_int_t ngx_stream_script_done(ngx_stream_script_compile_t *sc);
static ngx_int_t ngx_stream_script_add_copy_code(
    ngx_stream_script_compile_t *sc, ngx_str_t *value, ngx_uint_t last);
static ngx_int_t ngx_stream_script_add_var_code(
    ngx_stream_script_compile_t *sc, ngx_str_t *name);
#if (NGX_PCRE)
static ngx_int_t ngx_stream_script_add_capture_code(
    ngx_stream_script_compile_t *sc, ngx_uint_t n);
#endif
static ngx_int_t ngx_stream_script_add_full_name_code(
    ngx_stream_script_compile_t *sc);
static size_t ngx_stream_script_full_name_len_code(
    ngx_stream_script_engine_t *e);
static void ngx_stream_script_full_name_code(ngx_stream_script_engine_t *e);


#define ngx_stream_script_exit  (u_char *) &ngx_stream_script_exit_code

static uintptr_t ngx_stream_script_exit_code = (uintptr_t) NULL;


void
ngx_stream_script_flush_complex_value(ngx_stream_session_t *s,
    ngx_stream_complex_value_t *val)
{
    ngx_uint_t *index;

    index = val->flushes;

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

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

            index++;
        }
    }
}


ngx_int_t
ngx_stream_complex_value(ngx_stream_session_t *s,
    ngx_stream_complex_value_t *val, ngx_str_t *value)
{
    size_t                         len;
    ngx_stream_script_code_pt      code;
    ngx_stream_script_engine_t     e;
    ngx_stream_script_len_code_pt  lcode;

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

    ngx_stream_script_flush_complex_value(s, val);

    ngx_memzero(&e, sizeof(ngx_stream_script_engine_t));

    e.ip = val->lengths;
    e.session = s;
    e.flushed = 1;

    len = 0;

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

    value->len = len;
    value->data = ngx_pnalloc(s->connection->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_stream_script_code_pt *) e.ip;
        code((ngx_stream_script_engine_t *) &e);
    }

    *value = e.buf;

    return NGX_OK;
}


size_t
ngx_stream_complex_value_size(ngx_stream_session_t *s,
    ngx_stream_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_stream_complex_value(s, val, &value) != NGX_OK) {
        return default_value;
    }

    size = ngx_parse_size(&value);

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

    return size;
}


ngx_int_t
ngx_stream_compile_complex_value(ngx_stream_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_stream_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_stream_script_copy_code_t)
                  + sizeof(ngx_stream_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_stream_script_copy_code_t)
                   + sizeof(ngx_stream_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_stream_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_stream_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_stream_set_complex_value_slot(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf)
{
    char  *p = conf;

    ngx_str_t                            *value;
    ngx_stream_complex_value_t          **cv;
    ngx_stream_compile_complex_value_t    ccv;

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

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

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

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));

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

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

    return NGX_CONF_OK;
}


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

    ngx_str_t                            *value;
    ngx_stream_complex_value_t          **cv;
    ngx_stream_compile_complex_value_t    ccv;

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

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

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

    value = cf->args->elts;

    ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t));

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

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

    return NGX_CONF_OK;
}


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

    char                        *rv;
    ngx_stream_complex_value_t  *cv;

    rv = ngx_stream_set_complex_value_slot(cf, cmd, conf);

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

    cv = *(ngx_stream_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_uint_t
ngx_stream_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_stream_script_compile(ngx_stream_script_compile_t *sc)
{
    u_char       ch;
    ngx_str_t    name;
    ngx_uint_t   i, bracket;

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

            continue;
        }

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

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

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

            i++;
            name.len++;
        }

        sc->size += name.len;

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

    return ngx_stream_script_done(sc);

invalid_variable:

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

    return NGX_ERROR;
}


u_char *
ngx_stream_script_run(ngx_stream_session_t *s, ngx_str_t *value,
    void *code_lengths, size_t len, void *code_values)
{
    ngx_uint_t                      i;
    ngx_stream_script_code_pt       code;
    ngx_stream_script_engine_t      e;
    ngx_stream_core_main_conf_t    *cmcf;
    ngx_stream_script_len_code_pt   lcode;

    cmcf = ngx_stream_get_module_main_conf(s, ngx_stream_core_module);

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

    ngx_memzero(&e, sizeof(ngx_stream_script_engine_t));

    e.ip = code_lengths;
    e.session = s;
    e.flushed = 1;

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


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

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

    while (*(uintptr_t *) e.ip) {
        code = *(ngx_stream_script_code_pt *) e.ip;
        code((ngx_stream_script_engine_t *) &e);
    }

    return e.pos;
}


void
ngx_stream_script_flush_no_cacheable_variables(ngx_stream_session_t *s,
    ngx_array_t *indices)
{
    ngx_uint_t  n, *index;

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


static ngx_int_t
ngx_stream_script_init_arrays(ngx_stream_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_stream_script_copy_code_t)
                             + sizeof(ngx_stream_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_stream_script_copy_code_t)
                              + sizeof(ngx_stream_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_stream_script_done(ngx_stream_script_compile_t *sc)
{
    ngx_str_t    zero;
    uintptr_t   *code;

    if (sc->zero) {

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

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

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

    if (sc->complete_lengths) {
        code = ngx_stream_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_stream_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_stream_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_stream_script_add_copy_code(ngx_stream_script_compile_t *sc,
    ngx_str_t *value, ngx_uint_t last)
{
    u_char                         *p;
    size_t                          size, len, zero;
    ngx_stream_script_copy_code_t  *code;

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

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

    code->code = (ngx_stream_script_code_pt) (void *)
                                               ngx_stream_script_copy_len_code;
    code->len = len;

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

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

    code->code = ngx_stream_script_copy_code;
    code->len = len;

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

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

    return NGX_OK;
}


size_t
ngx_stream_script_copy_len_code(ngx_stream_script_engine_t *e)
{
    ngx_stream_script_copy_code_t  *code;

    code = (ngx_stream_script_copy_code_t *) e->ip;

    e->ip += sizeof(ngx_stream_script_copy_code_t);

    return code->len;
}


void
ngx_stream_script_copy_code(ngx_stream_script_engine_t *e)
{
    u_char                         *p;
    ngx_stream_script_copy_code_t  *code;

    code = (ngx_stream_script_copy_code_t *) e->ip;

    p = e->pos;

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

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

    ngx_log_debug2(NGX_LOG_DEBUG_STREAM, e->session->connection->log, 0,
                   "stream script copy: \"%*s\"", e->pos - p, p);
}


static ngx_int_t
ngx_stream_script_add_var_code(ngx_stream_script_compile_t *sc, ngx_str_t *name)
{
    ngx_int_t                      index, *p;
    ngx_stream_script_var_code_t  *code;

    index = ngx_stream_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_stream_script_add_code(*sc->lengths,
                                      sizeof(ngx_stream_script_var_code_t),
                                      NULL);
    if (code == NULL) {
        return NGX_ERROR;
    }

    code->code = (ngx_stream_script_code_pt) (void *)
                                           ngx_stream_script_copy_var_len_code;
    code->index = (uintptr_t) index;

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

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

    return NGX_OK;
}


size_t
ngx_stream_script_copy_var_len_code(ngx_stream_script_engine_t *e)
{
    ngx_stream_variable_value_t   *value;
    ngx_stream_script_var_code_t  *code;

    code = (ngx_stream_script_var_code_t *) e->ip;

    e->ip += sizeof(ngx_stream_script_var_code_t);

    if (e->flushed) {
        value = ngx_stream_get_indexed_variable(e->session, code->index);

    } else {
        value = ngx_stream_get_flushed_variable(e->session, code->index);
    }

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

    return 0;
}


void
ngx_stream_script_copy_var_code(ngx_stream_script_engine_t *e)
{
    u_char                        *p;
    ngx_stream_variable_value_t   *value;
    ngx_stream_script_var_code_t  *code;

    code = (ngx_stream_script_var_code_t *) e->ip;

    e->ip += sizeof(ngx_stream_script_var_code_t);

    if (!e->skip) {

        if (e->flushed) {
            value = ngx_stream_get_indexed_variable(e->session, code->index);

        } else {
            value = ngx_stream_get_flushed_variable(e->session, 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_STREAM,
                           e->session->connection->log, 0,
                           "stream script var: \"%*s\"", e->pos - p, p);
        }
    }
}


#if (NGX_PCRE)

static ngx_int_t
ngx_stream_script_add_capture_code(ngx_stream_script_compile_t *sc,
    ngx_uint_t n)
{
    ngx_stream_script_copy_capture_code_t  *code;

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

    code->code = (ngx_stream_script_code_pt) (void *)
                                       ngx_stream_script_copy_capture_len_code;
    code->n = 2 * n;


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

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

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

    return NGX_OK;
}


size_t
ngx_stream_script_copy_capture_len_code(ngx_stream_script_engine_t *e)
{
    int                                    *cap;
    ngx_uint_t                              n;
    ngx_stream_session_t                   *s;
    ngx_stream_script_copy_capture_code_t  *code;

    s = e->session;

    code = (ngx_stream_script_copy_capture_code_t *) e->ip;

    e->ip += sizeof(ngx_stream_script_copy_capture_code_t);

    n = code->n;

    if (n < s->ncaptures) {
        cap = s->captures;
        return cap[n + 1] - cap[n];
    }

    return 0;
}


void
ngx_stream_script_copy_capture_code(ngx_stream_script_engine_t *e)
{
    int                                    *cap;
    u_char                                 *p, *pos;
    ngx_uint_t                              n;
    ngx_stream_session_t                   *s;
    ngx_stream_script_copy_capture_code_t  *code;

    s = e->session;

    code = (ngx_stream_script_copy_capture_code_t *) e->ip;

    e->ip += sizeof(ngx_stream_script_copy_capture_code_t);

    n = code->n;

    pos = e->pos;

    if (n < s->ncaptures) {
        cap = s->captures;
        p = s->captures_data;
        e->pos = ngx_copy(pos, &p[cap[n]], cap[n + 1] - cap[n]);
    }

    ngx_log_debug2(NGX_LOG_DEBUG_STREAM, e->session->connection->log, 0,
                   "stream script capture: \"%*s\"", e->pos - pos, pos);
}

#endif


static ngx_int_t
ngx_stream_script_add_full_name_code(ngx_stream_script_compile_t *sc)
{
    ngx_stream_script_full_name_code_t  *code;

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

    code->code = (ngx_stream_script_code_pt) (void *)
                                          ngx_stream_script_full_name_len_code;
    code->conf_prefix = sc->conf_prefix;

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

    code->code = ngx_stream_script_full_name_code;
    code->conf_prefix = sc->conf_prefix;

    return NGX_OK;
}


static size_t
ngx_stream_script_full_name_len_code(ngx_stream_script_engine_t *e)
{
    ngx_stream_script_full_name_code_t  *code;

    code = (ngx_stream_script_full_name_code_t *) e->ip;

    e->ip += sizeof(ngx_stream_script_full_name_code_t);

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


static void
ngx_stream_script_full_name_code(ngx_stream_script_engine_t *e)
{
    ngx_stream_script_full_name_code_t  *code;

    ngx_str_t  value, *prefix;

    code = (ngx_stream_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->session->connection->pool, prefix, &value)
        != NGX_OK)
    {
        e->ip = ngx_stream_script_exit;
        return;
    }

    e->buf = value;

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, e->session->connection->log, 0,
                   "stream script fullname: \"%V\"", &value);

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