view src/http/modules/perl/nginx.xs @ 8299:83c4622053b0

Upstream: fixed zero size buf alerts on extra data (ticket #2117). After 7675:9afa45068b8f and 7678:bffcc5af1d72 (1.19.1), during non-buffered simple proxying, responses with extra data might result in zero size buffers being generated and "zero size buf" alerts in writer. This bug is similar to the one with FastCGI proxying fixed in 7689:da8d758aabeb. In non-buffered mode, normally the filter function is not called if u->length is already 0, since u->length is checked after each call of the filter function. There is a case when this can happen though: if the response length is 0, and there are pre-read response body data left after reading response headers. As such, a check for u->length is needed at the start of non-buffered filter functions, similar to the one for p->length present in buffered filter functions. Appropriate checks added to the existing non-buffered copy filters in the upstream (used by scgi and uwsgi proxying) and proxy modules.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 12 Jan 2021 16:59:31 +0300
parents 56b4fb46ba7d
children ef6a3a99a81a
line wrap: on
line source


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


#define PERL_NO_GET_CONTEXT

#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include <ngx_http_perl_module.h>

#include "XSUB.h"


#define ngx_http_perl_set_request(r, ctx)                                     \
                                                                              \
    ctx = INT2PTR(ngx_http_perl_ctx_t *, SvIV((SV *) SvRV(ST(0))));           \
    r = ctx->request


#define ngx_http_perl_set_targ(p, len)                                        \
                                                                              \
    SvUPGRADE(TARG, SVt_PV);                                                  \
    SvPOK_on(TARG);                                                           \
    sv_setpvn(TARG, (char *) p, len)


static ngx_int_t
ngx_http_perl_sv2str(pTHX_ ngx_http_request_t *r, ngx_str_t *s, SV *sv)
{
    u_char  *p;
    STRLEN   len;

    if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PV) {
        sv = SvRV(sv);
    }

    p = (u_char *) SvPV(sv, len);

    s->len = len;

    if (SvREADONLY(sv) && SvPOK(sv)) {
        s->data = p;

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "perl sv2str: %08XD \"%V\"", sv->sv_flags, s);

        return NGX_OK;
    }

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

    ngx_memcpy(s->data, p, len);

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "perl sv2str: %08XD \"%V\"", sv->sv_flags, s);

    return NGX_OK;
}


static ngx_int_t
ngx_http_perl_output(ngx_http_request_t *r, ngx_http_perl_ctx_t *ctx,
    ngx_buf_t *b)
{
    ngx_chain_t   out;
#if (NGX_HTTP_SSI)
    ngx_chain_t  *cl;

    if (ctx->ssi) {
        cl = ngx_alloc_chain_link(r->pool);
        if (cl == NULL) {
            return NGX_ERROR;
        }

        cl->buf = b;
        cl->next = NULL;
        *ctx->ssi->last_out = cl;
        ctx->ssi->last_out = &cl->next;

        return NGX_OK;
    }
#endif

    out.buf = b;
    out.next = NULL;

    return ngx_http_output_filter(r, &out);
}


MODULE = nginx    PACKAGE = nginx


PROTOTYPES: DISABLE


void
status(r, code)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->variable) {
        croak("status(): cannot be used in variable handler");
    }

    r->headers_out.status = SvIV(ST(1));

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "perl status: %d", r->headers_out.status);

    XSRETURN_UNDEF;


void
send_http_header(r, ...)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    SV                   *sv;
    ngx_int_t             rc;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->error) {
        croak("send_http_header(): called after error");
    }

    if (ctx->variable) {
        croak("send_http_header(): cannot be used in variable handler");
    }

    if (ctx->header_sent) {
        croak("send_http_header(): header already sent");
    }

    if (ctx->redirect_uri.len) {
        croak("send_http_header(): cannot be used with internal_redirect()");
    }

    if (r->headers_out.status == 0) {
        r->headers_out.status = NGX_HTTP_OK;
    }

    if (items != 1) {
        sv = ST(1);

        if (ngx_http_perl_sv2str(aTHX_ r, &r->headers_out.content_type, sv)
            != NGX_OK)
        {
            ctx->error = 1;
            croak("ngx_http_perl_sv2str() failed");
        }

        r->headers_out.content_type_len = r->headers_out.content_type.len;

    } else {
        if (ngx_http_set_content_type(r) != NGX_OK) {
            ctx->error = 1;
            croak("ngx_http_set_content_type() failed");
        }
    }

    ctx->header_sent = 1;

    r->disable_not_modified = 1;

    rc = ngx_http_send_header(r);

    if (rc == NGX_ERROR || rc > NGX_OK) {
        ctx->error = 1;
        ctx->status = rc;
        croak("ngx_http_send_header() failed");
    }


void
header_only(r)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;

    ngx_http_perl_set_request(r, ctx);

    sv_upgrade(TARG, SVt_IV);
    sv_setiv(TARG, r->header_only);

    ST(0) = TARG;


void
uri(r)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;

    ngx_http_perl_set_request(r, ctx);
    ngx_http_perl_set_targ(r->uri.data, r->uri.len);

    ST(0) = TARG;


void
args(r)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;

    ngx_http_perl_set_request(r, ctx);
    ngx_http_perl_set_targ(r->args.data, r->args.len);

    ST(0) = TARG;


void
request_method(r)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;

    ngx_http_perl_set_request(r, ctx);
    ngx_http_perl_set_targ(r->method_name.data, r->method_name.len);

    ST(0) = TARG;


void
remote_addr(r)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;

    ngx_http_perl_set_request(r, ctx);
    ngx_http_perl_set_targ(r->connection->addr_text.data,
                           r->connection->addr_text.len);

    ST(0) = TARG;


void
header_in(r, key)
    CODE:

    dXSTARG;
    ngx_http_request_t         *r;
    ngx_http_perl_ctx_t        *ctx;
    SV                         *key;
    u_char                     *p, *lowcase_key, *value, sep;
    STRLEN                      len;
    ssize_t                     size;
    ngx_uint_t                  i, n, hash;
    ngx_array_t                *a;
    ngx_list_part_t            *part;
    ngx_table_elt_t            *h, **ph;
    ngx_http_header_t          *hh;
    ngx_http_core_main_conf_t  *cmcf;

    ngx_http_perl_set_request(r, ctx);

    key = ST(1);

    if (SvROK(key) && SvTYPE(SvRV(key)) == SVt_PV) {
        key = SvRV(key);
    }

    p = (u_char *) SvPV(key, len);

    /* look up hashed headers */

    lowcase_key = ngx_pnalloc(r->pool, len);
    if (lowcase_key == NULL) {
        ctx->error = 1;
        croak("ngx_pnalloc() failed");
    }

    hash = ngx_hash_strlow(lowcase_key, p, len);

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    hh = ngx_hash_find(&cmcf->headers_in_hash, hash, lowcase_key, len);

    if (hh) {

        if (hh->offset == offsetof(ngx_http_headers_in_t, cookies)) {
            sep = ';';
            goto multi;
        }
#if (NGX_HTTP_X_FORWARDED_FOR)
        if (hh->offset == offsetof(ngx_http_headers_in_t, x_forwarded_for)) {
            sep = ',';
            goto multi;
        }
#endif

        ph = (ngx_table_elt_t **) ((char *) &r->headers_in + hh->offset);

        if (*ph) {
            ngx_http_perl_set_targ((*ph)->value.data, (*ph)->value.len);

            goto done;
        }

        XSRETURN_UNDEF;

    multi:

        /* Cookie, X-Forwarded-For */

        a = (ngx_array_t *) ((char *) &r->headers_in + hh->offset);

        n = a->nelts;

        if (n == 0) {
            XSRETURN_UNDEF;
        }

        ph = a->elts;

        if (n == 1) {
            ngx_http_perl_set_targ((*ph)->value.data, (*ph)->value.len);

            goto done;
        }

        size = - (ssize_t) (sizeof("; ") - 1);

        for (i = 0; i < n; i++) {
            size += ph[i]->value.len + sizeof("; ") - 1;
        }

        value = ngx_pnalloc(r->pool, size);
        if (value == NULL) {
            ctx->error = 1;
            croak("ngx_pnalloc() failed");
        }

        p = value;

        for (i = 0; /* void */ ; i++) {
            p = ngx_copy(p, ph[i]->value.data, ph[i]->value.len);

            if (i == n - 1) {
                break;
            }

            *p++ = sep; *p++ = ' ';
        }

        ngx_http_perl_set_targ(value, size);

        goto done;
    }

    /* iterate over all headers */

    part = &r->headers_in.headers.part;
    h = part->elts;

    for (i = 0; /* void */ ; i++) {

        if (i >= part->nelts) {
            if (part->next == NULL) {
                break;
            }

            part = part->next;
            h = part->elts;
            i = 0;
        }

        if (len != h[i].key.len
            || ngx_strcasecmp(p, h[i].key.data) != 0)
        {
            continue;
        }

        ngx_http_perl_set_targ(h[i].value.data, h[i].value.len);

        goto done;
    }

    XSRETURN_UNDEF;

    done:

    ST(0) = TARG;


void
has_request_body(r, next)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    ngx_int_t             rc;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->variable) {
        croak("has_request_body(): cannot be used in variable handler");
    }

    if (ctx->next) {
        croak("has_request_body(): another handler active");
    }

    if (r->headers_in.content_length_n <= 0 && !r->headers_in.chunked) {
        XSRETURN_UNDEF;
    }

    ctx->next = SvRV(ST(1));

    r->request_body_in_single_buf = 1;
    r->request_body_in_persistent_file = 1;
    r->request_body_in_clean_file = 1;

    if (r->request_body_in_file_only) {
        r->request_body_file_log_level = 0;
    }

    rc = ngx_http_read_client_request_body(r, ngx_http_perl_handle_request);

    if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
        ctx->error = 1;
        ctx->status = rc;
        ctx->next = NULL;
        croak("ngx_http_read_client_request_body() failed");
    }

    sv_upgrade(TARG, SVt_IV);
    sv_setiv(TARG, 1);

    ST(0) = TARG;


void
request_body(r)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    u_char               *p, *data;
    size_t                len;
    ngx_buf_t            *buf;
    ngx_chain_t          *cl;

    ngx_http_perl_set_request(r, ctx);

    if (r->request_body == NULL
        || r->request_body->temp_file
        || r->request_body->bufs == NULL)
    {
        XSRETURN_UNDEF;
    }

    cl = r->request_body->bufs;
    buf = cl->buf;

    if (cl->next == NULL) {
        len = buf->last - buf->pos;
        data = buf->pos;
        goto done;
    }

    len = buf->last - buf->pos;
    cl = cl->next;

    for ( /* void */ ; cl; cl = cl->next) {
        buf = cl->buf;
        len += buf->last - buf->pos;
    }

    p = ngx_pnalloc(r->pool, len);
    if (p == NULL) {
        ctx->error = 1;
        croak("ngx_pnalloc() failed");
    }

    data = p;
    cl = r->request_body->bufs;

    for ( /* void */ ; cl; cl = cl->next) {
        buf = cl->buf;
        p = ngx_cpymem(p, buf->pos, buf->last - buf->pos);
    }

    done:

    if (len == 0) {
        XSRETURN_UNDEF;
    }

    ngx_http_perl_set_targ(data, len);

    ST(0) = TARG;


void
request_body_file(r)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;

    ngx_http_perl_set_request(r, ctx);

    if (r->request_body == NULL || r->request_body->temp_file == NULL) {
        XSRETURN_UNDEF;
    }

    ngx_http_perl_set_targ(r->request_body->temp_file->file.name.data,
                           r->request_body->temp_file->file.name.len);

    ST(0) = TARG;


void
discard_request_body(r)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    ngx_int_t             rc;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->variable) {
        croak("discard_request_body(): cannot be used in variable handler");
    }

    rc = ngx_http_discard_request_body(r);

    if (rc != NGX_OK) {
        ctx->error = 1;
        ctx->status = rc;
        croak("ngx_http_discard_request_body() failed");
    }


void
header_out(r, key, value)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    SV                   *key;
    SV                   *value;
    ngx_table_elt_t      *header;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->error) {
        croak("header_out(): called after error");
    }

    if (ctx->variable) {
        croak("header_out(): cannot be used in variable handler");
    }

    key = ST(1);
    value = ST(2);

    header = ngx_list_push(&r->headers_out.headers);
    if (header == NULL) {
        ctx->error = 1;
        croak("ngx_list_push() failed");
    }

    header->hash = 1;

    if (ngx_http_perl_sv2str(aTHX_ r, &header->key, key) != NGX_OK) {
        header->hash = 0;
        ctx->error = 1;
        croak("ngx_http_perl_sv2str() failed");
    }

    if (ngx_http_perl_sv2str(aTHX_ r, &header->value, value) != NGX_OK) {
        header->hash = 0;
        ctx->error = 1;
        croak("ngx_http_perl_sv2str() failed");
    }

    if (header->key.len == sizeof("Content-Length") - 1
        && ngx_strncasecmp(header->key.data, (u_char *) "Content-Length",
                           sizeof("Content-Length") - 1) == 0)
    {
        r->headers_out.content_length_n = (off_t) SvIV(value);
        r->headers_out.content_length = header;
    }

    if (header->key.len == sizeof("Content-Encoding") - 1
        && ngx_strncasecmp(header->key.data, (u_char *) "Content-Encoding",
                           sizeof("Content-Encoding") - 1) == 0)
    {
        r->headers_out.content_encoding = header;
    }


void
filename(r)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    size_t                root;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->filename.data) {
        goto done;
    }

    if (ngx_http_map_uri_to_path(r, &ctx->filename, &root, 0) == NULL) {
        ctx->error = 1;
        croak("ngx_http_map_uri_to_path() failed");
    }

    ctx->filename.len--;
    sv_setpv(PL_statname, (char *) ctx->filename.data);

    done:

    ngx_http_perl_set_targ(ctx->filename.data, ctx->filename.len);

    ST(0) = TARG;


void
print(r, ...)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    SV                   *sv;
    int                   i;
    u_char               *p;
    size_t                size;
    STRLEN                len;
    ngx_int_t             rc;
    ngx_buf_t            *b;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->error) {
        croak("print(): called after error");
    }

    if (ctx->variable) {
        croak("print(): cannot be used in variable handler");
    }

    if (!ctx->header_sent) {
        croak("print(): header not sent");
    }

    if (items == 2) {

        /*
         * do zero copy for prolate single read-only SV:
         *     $r->print("some text\n");
         */

        sv = ST(1);

        if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PV) {
            sv = SvRV(sv);
        }

        if (SvREADONLY(sv) && SvPOK(sv)) {

            p = (u_char *) SvPV(sv, len);

            if (len == 0) {
                XSRETURN_EMPTY;
            }

            b = ngx_calloc_buf(r->pool);
            if (b == NULL) {
                ctx->error = 1;
                croak("ngx_calloc_buf() failed");
            }

            b->memory = 1;
            b->pos = p;
            b->last = p + len;
            b->start = p;
            b->end = b->last;

            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "$r->print: read-only SV: %z", len);

            goto out;
        }
    }

    size = 0;

    for (i = 1; i < items; i++) {

        sv = ST(i);

        if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PV) {
            sv = SvRV(sv);
        }

        (void) SvPV(sv, len);

        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "$r->print: copy SV: %z", len);

        size += len;
    }

    if (size == 0) {
        XSRETURN_EMPTY;
    }

    b = ngx_create_temp_buf(r->pool, size);
    if (b == NULL) {
        ctx->error = 1;
        croak("ngx_create_temp_buf() failed");
    }

    for (i = 1; i < items; i++) {
        sv = ST(i);

        if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PV) {
            sv = SvRV(sv);
        }

        p = (u_char *) SvPV(sv, len);
        b->last = ngx_cpymem(b->last, p, len);
    }

    out:

    rc = ngx_http_perl_output(r, ctx, b);

    if (rc == NGX_ERROR) {
        ctx->error = 1;
        croak("ngx_http_perl_output() failed");
    }


void
sendfile(r, filename, offset = -1, bytes = 0)
    CODE:

    ngx_http_request_t        *r;
    ngx_http_perl_ctx_t       *ctx;
    char                      *filename;
    off_t                      offset;
    size_t                     bytes;
    ngx_int_t                  rc;
    ngx_str_t                  path;
    ngx_buf_t                 *b;
    ngx_open_file_info_t       of;
    ngx_http_core_loc_conf_t  *clcf;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->error) {
        croak("sendfile(): called after error");
    }

    if (ctx->variable) {
        croak("sendfile(): cannot be used in variable handler");
    }

    if (!ctx->header_sent) {
        croak("sendfile(): header not sent");
    }

    filename = SvPV_nolen(ST(1));

    if (filename == NULL) {
        croak("sendfile(): NULL filename");
    }

    offset = items < 3 ? -1 : SvIV(ST(2));
    bytes = items < 4 ? 0 : SvIV(ST(3));

    b = ngx_calloc_buf(r->pool);
    if (b == NULL) {
        ctx->error = 1;
        croak("ngx_calloc_buf() failed");
    }

    b->file = ngx_pcalloc(r->pool, sizeof(ngx_file_t));
    if (b->file == NULL) {
        ctx->error = 1;
        croak("ngx_pcalloc() failed");
    }

    path.len = ngx_strlen(filename);

    path.data = ngx_pnalloc(r->pool, path.len + 1);
    if (path.data == NULL) {
        ctx->error = 1;
        croak("ngx_pnalloc() failed");
    }

    (void) ngx_cpystrn(path.data, (u_char *) filename, path.len + 1);

    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.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) {
        ctx->error = 1;
        croak("ngx_http_set_disable_symlinks() failed");
    }

    if (ngx_open_cached_file(clcf->open_file_cache, &path, &of, r->pool)
        != NGX_OK)
    {
        if (of.err == 0) {
            ctx->error = 1;
            croak("ngx_open_cached_file() failed");
        }

        ngx_log_error(NGX_LOG_CRIT, r->connection->log, ngx_errno,
                      "%s \"%s\" failed", of.failed, filename);

        ctx->error = 1;
        croak("ngx_open_cached_file() failed");
    }

    if (offset == -1) {
        offset = 0;
    }

    if (bytes == 0) {
        bytes = of.size - offset;
    }

    b->in_file = 1;

    b->file_pos = offset;
    b->file_last = offset + bytes;

    b->file->fd = of.fd;
    b->file->log = r->connection->log;
    b->file->directio = of.is_directio;

    rc = ngx_http_perl_output(r, ctx, b);

    if (rc == NGX_ERROR) {
        ctx->error = 1;
        croak("ngx_http_perl_output() failed");
    }


void
flush(r)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    ngx_int_t             rc;
    ngx_buf_t            *b;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->error) {
        croak("flush(): called after error");
    }

    if (ctx->variable) {
        croak("flush(): cannot be used in variable handler");
    }

    if (!ctx->header_sent) {
        croak("flush(): header not sent");
    }

    b = ngx_calloc_buf(r->pool);
    if (b == NULL) {
        ctx->error = 1;
        croak("ngx_calloc_buf() failed");
    }

    b->flush = 1;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "$r->flush");

    rc = ngx_http_perl_output(r, ctx, b);

    if (rc == NGX_ERROR) {
        ctx->error = 1;
        croak("ngx_http_perl_output() failed");
    }

    XSRETURN_EMPTY;


void
internal_redirect(r, uri)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    SV                   *uri;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->variable) {
        croak("internal_redirect(): cannot be used in variable handler");
    }

    if (ctx->header_sent) {
        croak("internal_redirect(): header already sent");
    }

    uri = ST(1);

    if (ngx_http_perl_sv2str(aTHX_ r, &ctx->redirect_uri, uri) != NGX_OK) {
        ctx->error = 1;
        croak("ngx_http_perl_sv2str() failed");
    }


void
allow_ranges(r)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->variable) {
        croak("allow_ranges(): cannot be used in variable handler");
    }

    r->allow_ranges = 1;


void
unescape(r, text, type = 0)
    CODE:

    dXSTARG;
    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    SV                   *text;
    int                   type;
    u_char               *p, *dst, *src;
    STRLEN                len;

    ngx_http_perl_set_request(r, ctx);

    text = ST(1);

    src = (u_char *) SvPV(text, len);

    p = ngx_pnalloc(r->pool, len + 1);
    if (p == NULL) {
        ctx->error = 1;
        croak("ngx_pnalloc() failed");
    }

    dst = p;

    type = items < 3 ? 0 : SvIV(ST(2));

    ngx_unescape_uri(&dst, &src, len, (ngx_uint_t) type);
    *dst = '\0';

    ngx_http_perl_set_targ(p, dst - p);

    ST(0) = TARG;


void
variable(r, name, value = NULL)
    CODE:

    dXSTARG;
    ngx_http_request_t         *r;
    ngx_http_perl_ctx_t        *ctx;
    SV                         *name, *value;
    u_char                     *p, *lowcase;
    STRLEN                      len;
    ngx_str_t                   var, val;
    ngx_uint_t                  i, hash;
    ngx_http_perl_var_t        *v;
    ngx_http_variable_value_t  *vv;

    ngx_http_perl_set_request(r, ctx);

    name = ST(1);

    if (SvROK(name) && SvTYPE(SvRV(name)) == SVt_PV) {
        name = SvRV(name);
    }

    if (items == 2) {
        value = NULL;

    } else {
        value = ST(2);

        if (SvROK(value) && SvTYPE(SvRV(value)) == SVt_PV) {
            value = SvRV(value);
        }

        if (ngx_http_perl_sv2str(aTHX_ r, &val, value) != NGX_OK) {
            ctx->error = 1;
            croak("ngx_http_perl_sv2str() failed");
        }
    }

    p = (u_char *) SvPV(name, len);

    lowcase = ngx_pnalloc(r->pool, len);
    if (lowcase == NULL) {
        ctx->error = 1;
        croak("ngx_pnalloc() failed");
    }

    hash = ngx_hash_strlow(lowcase, p, len);

    var.len = len;
    var.data = lowcase;
#if (NGX_DEBUG)

    if (value) {
        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "perl variable: \"%V\"=\"%V\"", &var, &val);
    } else {
        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "perl variable: \"%V\"", &var);
    }
#endif

    vv = ngx_http_get_variable(r, &var, hash);
    if (vv == NULL) {
        ctx->error = 1;
        croak("ngx_http_get_variable() failed");
    }

    if (vv->not_found) {

        if (ctx->variables) {

            v = ctx->variables->elts;
            for (i = 0; i < ctx->variables->nelts; i++) {

                if (hash != v[i].hash
                    || len != v[i].name.len
                    || ngx_strncmp(lowcase, v[i].name.data, len) != 0)
                {
                    continue;
                }

                if (value) {
                    v[i].value = val;
                    XSRETURN_UNDEF;
                }

                ngx_http_perl_set_targ(v[i].value.data, v[i].value.len);

                goto done;
            }
        }

        if (value) {
            if (ctx->variables == NULL) {
                ctx->variables = ngx_array_create(r->pool, 1,
                                                  sizeof(ngx_http_perl_var_t));
                if (ctx->variables == NULL) {
                    ctx->error = 1;
                    croak("ngx_array_create() failed");
                }
            }

            v = ngx_array_push(ctx->variables);
            if (v == NULL) {
                ctx->error = 1;
                croak("ngx_array_push() failed");
            }

            v->hash = hash;
            v->name.len = len;
            v->name.data = lowcase;
            v->value = val;

            XSRETURN_UNDEF;
        }

        XSRETURN_UNDEF;
    }

    if (value) {
        vv->len = val.len;
        vv->valid = 1;
        vv->no_cacheable = 0;
        vv->not_found = 0;
        vv->data = val.data;

        XSRETURN_UNDEF;
    }

    ngx_http_perl_set_targ(vv->data, vv->len);

    done:

    ST(0) = TARG;


void
sleep(r, sleep, next)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    ngx_msec_t            sleep;

    ngx_http_perl_set_request(r, ctx);

    if (ctx->variable) {
        croak("sleep(): cannot be used in variable handler");
    }

    if (ctx->next) {
        croak("sleep(): another handler active");
    }

    sleep = (ngx_msec_t) SvIV(ST(1));

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "perl sleep: %M", sleep);

    ctx->next = SvRV(ST(2));

    r->connection->write->delayed = 1;
    ngx_add_timer(r->connection->write, sleep);

    r->write_event_handler = ngx_http_perl_sleep_handler;
    r->main->count++;


void
log_error(r, err, msg)
    CODE:

    ngx_http_request_t   *r;
    ngx_http_perl_ctx_t  *ctx;
    SV                   *err, *msg;
    u_char               *p;
    STRLEN                len;
    ngx_err_t             e;

    ngx_http_perl_set_request(r, ctx);

    err = ST(1);

    if (SvROK(err) && SvTYPE(SvRV(err)) == SVt_PV) {
        err = SvRV(err);
    }

    e = SvIV(err);

    msg = ST(2);

    if (SvROK(msg) && SvTYPE(SvRV(msg)) == SVt_PV) {
        msg = SvRV(msg);
    }

    p = (u_char *) SvPV(msg, len);

    ngx_log_error(NGX_LOG_ERR, r->connection->log, e, "perl: %s", p);