view src/stream/ngx_stream_script.c @ 8867:5119c8150478

Fixed runtime handling of systems without EPOLLRDHUP support. In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP support in the kernel (but with EPOLLRDHUP in headers) was broken. Before the change, rev->available was never set to 0 unless ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP introduced in 6536:f7849bfb6d21 succeeded). After the change, rev->available might reach 0 on systems without runtime EPOLLRDHUP support, stopping further reading in ngx_readv_chain() and ngx_unix_recv(). And, if EOF happened to be already reported along with the last event, it is not reported again by epoll_wait(), leading to connection hangs and timeouts on such systems. This affects Linux kernels before 2.6.17 if nginx was compiled with newer headers, and, more importantly, emulation layers, such as DigitalOcean's App Platform's / gVisor's epoll emulation layer. Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author Marcus Ball <marcus.ball@live.com>
date Mon, 30 May 2022 02:38:07 +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);
}