view src/stream/ngx_stream_script.c @ 8006:32b0ba4855a6

HTTP/2: made it possible to flush response headers (ticket #1743). Response headers can be buffered in the SSL buffer. But stream's fake connection buffered flag did not reflect this, so any attempts to flush the buffer without sending additional data were stopped by the write filter. It does not seem to be possible to reflect this in fc->buffered though, as we never known if main connection's c->buffered corresponds to the particular stream or not. As such, fc->buffered might prevent request finalization due to sending data on some other stream. Fix is to implement handling of flush buffers when the c->need_flush_buf flag is set, similarly to the existing last buffer handling. The same flag is now used for UDP sockets in the stream module instead of explicit checking of c->type.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 03 Feb 2022 01:44:38 +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);
}