view src/stream/ngx_stream_variables.c @ 8971:1e2f4e9c8195 quic

QUIC: reworked migration handling. The quic connection now holds active, backup and probe paths instead of sockets. The number of migration paths is now limited and cannot be inflated by a bad client or an attacker. The client id is now associated with path rather than socket. This allows to simplify processing of output and connection ids handling. New migration abandons any previously started migrations. This allows to free consumed client ids and request new for use in future migrations and make progress in case when connection id limit is hit during migration. A path now can be revalidated without losing its state. The patch also fixes various issues with NAT rebinding case handling: - paths are now validated (previously, there was no validation and paths were left in limited state) - attempt to reuse id on different path is now again verified (this was broken in 40445fc7c403) - former path is now validated in case of apparent migration
author Vladimir Homutov <vl@nginx.com>
date Wed, 19 Jan 2022 22:39:24 +0300
parents 89adf49fe76a
children cca4c8a715de
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>
#include <nginx.h>

static ngx_stream_variable_t *ngx_stream_add_prefix_variable(ngx_conf_t *cf,
    ngx_str_t *name, ngx_uint_t flags);

static ngx_int_t ngx_stream_variable_binary_remote_addr(
    ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_remote_addr(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_remote_port(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_proxy_protocol_addr(
    ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_proxy_protocol_port(
    ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_server_addr(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_server_port(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_bytes(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_session_time(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_status(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_connection(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);

static ngx_int_t ngx_stream_variable_nginx_version(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_hostname(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_pid(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_msec(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_time_iso8601(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_time_local(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_variable_protocol(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);


static ngx_stream_variable_t  ngx_stream_core_variables[] = {

    { ngx_string("binary_remote_addr"), NULL,
      ngx_stream_variable_binary_remote_addr, 0, 0, 0 },

    { ngx_string("remote_addr"), NULL,
      ngx_stream_variable_remote_addr, 0, 0, 0 },

    { ngx_string("remote_port"), NULL,
      ngx_stream_variable_remote_port, 0, 0, 0 },

    { ngx_string("proxy_protocol_addr"), NULL,
      ngx_stream_variable_proxy_protocol_addr,
      offsetof(ngx_proxy_protocol_t, src_addr), 0, 0 },

    { ngx_string("proxy_protocol_port"), NULL,
      ngx_stream_variable_proxy_protocol_port,
      offsetof(ngx_proxy_protocol_t, src_port), 0, 0 },

    { ngx_string("proxy_protocol_server_addr"), NULL,
      ngx_stream_variable_proxy_protocol_addr,
      offsetof(ngx_proxy_protocol_t, dst_addr), 0, 0 },

    { ngx_string("proxy_protocol_server_port"), NULL,
      ngx_stream_variable_proxy_protocol_port,
      offsetof(ngx_proxy_protocol_t, dst_port), 0, 0 },

    { ngx_string("server_addr"), NULL,
      ngx_stream_variable_server_addr, 0, 0, 0 },

    { ngx_string("server_port"), NULL,
      ngx_stream_variable_server_port, 0, 0, 0 },

    { ngx_string("bytes_sent"), NULL, ngx_stream_variable_bytes,
      0, 0, 0 },

    { ngx_string("bytes_received"), NULL, ngx_stream_variable_bytes,
      1, 0, 0 },

    { ngx_string("session_time"), NULL, ngx_stream_variable_session_time,
      0, NGX_STREAM_VAR_NOCACHEABLE, 0 },

    { ngx_string("status"), NULL, ngx_stream_variable_status,
      0, NGX_STREAM_VAR_NOCACHEABLE, 0 },

    { ngx_string("connection"), NULL,
      ngx_stream_variable_connection, 0, 0, 0 },

    { ngx_string("nginx_version"), NULL, ngx_stream_variable_nginx_version,
      0, 0, 0 },

    { ngx_string("hostname"), NULL, ngx_stream_variable_hostname,
      0, 0, 0 },

    { ngx_string("pid"), NULL, ngx_stream_variable_pid,
      0, 0, 0 },

    { ngx_string("msec"), NULL, ngx_stream_variable_msec,
      0, NGX_STREAM_VAR_NOCACHEABLE, 0 },

    { ngx_string("time_iso8601"), NULL, ngx_stream_variable_time_iso8601,
      0, NGX_STREAM_VAR_NOCACHEABLE, 0 },

    { ngx_string("time_local"), NULL, ngx_stream_variable_time_local,
      0, NGX_STREAM_VAR_NOCACHEABLE, 0 },

    { ngx_string("protocol"), NULL,
      ngx_stream_variable_protocol, 0, 0, 0 },

      ngx_stream_null_variable
};


ngx_stream_variable_value_t  ngx_stream_variable_null_value =
    ngx_stream_variable("");
ngx_stream_variable_value_t  ngx_stream_variable_true_value =
    ngx_stream_variable("1");


static ngx_uint_t  ngx_stream_variable_depth = 100;


ngx_stream_variable_t *
ngx_stream_add_variable(ngx_conf_t *cf, ngx_str_t *name, ngx_uint_t flags)
{
    ngx_int_t                     rc;
    ngx_uint_t                    i;
    ngx_hash_key_t               *key;
    ngx_stream_variable_t        *v;
    ngx_stream_core_main_conf_t  *cmcf;

    if (name->len == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid variable name \"$\"");
        return NULL;
    }

    if (flags & NGX_STREAM_VAR_PREFIX) {
        return ngx_stream_add_prefix_variable(cf, name, flags);
    }

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);

    key = cmcf->variables_keys->keys.elts;
    for (i = 0; i < cmcf->variables_keys->keys.nelts; i++) {
        if (name->len != key[i].key.len
            || ngx_strncasecmp(name->data, key[i].key.data, name->len) != 0)
        {
            continue;
        }

        v = key[i].value;

        if (!(v->flags & NGX_STREAM_VAR_CHANGEABLE)) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "the duplicate \"%V\" variable", name);
            return NULL;
        }

        if (!(flags & NGX_STREAM_VAR_WEAK)) {
            v->flags &= ~NGX_STREAM_VAR_WEAK;
        }

        return v;
    }

    v = ngx_palloc(cf->pool, sizeof(ngx_stream_variable_t));
    if (v == NULL) {
        return NULL;
    }

    v->name.len = name->len;
    v->name.data = ngx_pnalloc(cf->pool, name->len);
    if (v->name.data == NULL) {
        return NULL;
    }

    ngx_strlow(v->name.data, name->data, name->len);

    v->set_handler = NULL;
    v->get_handler = NULL;
    v->data = 0;
    v->flags = flags;
    v->index = 0;

    rc = ngx_hash_add_key(cmcf->variables_keys, &v->name, v, 0);

    if (rc == NGX_ERROR) {
        return NULL;
    }

    if (rc == NGX_BUSY) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "conflicting variable name \"%V\"", name);
        return NULL;
    }

    return v;
}


static ngx_stream_variable_t *
ngx_stream_add_prefix_variable(ngx_conf_t *cf, ngx_str_t *name,
    ngx_uint_t flags)
{
    ngx_uint_t                    i;
    ngx_stream_variable_t        *v;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);

    v = cmcf->prefix_variables.elts;
    for (i = 0; i < cmcf->prefix_variables.nelts; i++) {
        if (name->len != v[i].name.len
            || ngx_strncasecmp(name->data, v[i].name.data, name->len) != 0)
        {
            continue;
        }

        v = &v[i];

        if (!(v->flags & NGX_STREAM_VAR_CHANGEABLE)) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                               "the duplicate \"%V\" variable", name);
            return NULL;
        }

        if (!(flags & NGX_STREAM_VAR_WEAK)) {
            v->flags &= ~NGX_STREAM_VAR_WEAK;
        }

        return v;
    }

    v = ngx_array_push(&cmcf->prefix_variables);
    if (v == NULL) {
        return NULL;
    }

    v->name.len = name->len;
    v->name.data = ngx_pnalloc(cf->pool, name->len);
    if (v->name.data == NULL) {
        return NULL;
    }

    ngx_strlow(v->name.data, name->data, name->len);

    v->set_handler = NULL;
    v->get_handler = NULL;
    v->data = 0;
    v->flags = flags;
    v->index = 0;

    return v;
}


ngx_int_t
ngx_stream_get_variable_index(ngx_conf_t *cf, ngx_str_t *name)
{
    ngx_uint_t                    i;
    ngx_stream_variable_t        *v;
    ngx_stream_core_main_conf_t  *cmcf;

    if (name->len == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid variable name \"$\"");
        return NGX_ERROR;
    }

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);

    v = cmcf->variables.elts;

    if (v == NULL) {
        if (ngx_array_init(&cmcf->variables, cf->pool, 4,
                           sizeof(ngx_stream_variable_t))
            != NGX_OK)
        {
            return NGX_ERROR;
        }

    } else {
        for (i = 0; i < cmcf->variables.nelts; i++) {
            if (name->len != v[i].name.len
                || ngx_strncasecmp(name->data, v[i].name.data, name->len) != 0)
            {
                continue;
            }

            return i;
        }
    }

    v = ngx_array_push(&cmcf->variables);
    if (v == NULL) {
        return NGX_ERROR;
    }

    v->name.len = name->len;
    v->name.data = ngx_pnalloc(cf->pool, name->len);
    if (v->name.data == NULL) {
        return NGX_ERROR;
    }

    ngx_strlow(v->name.data, name->data, name->len);

    v->set_handler = NULL;
    v->get_handler = NULL;
    v->data = 0;
    v->flags = 0;
    v->index = cmcf->variables.nelts - 1;

    return v->index;
}


ngx_stream_variable_value_t *
ngx_stream_get_indexed_variable(ngx_stream_session_t *s, ngx_uint_t index)
{
    ngx_stream_variable_t        *v;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_get_module_main_conf(s, ngx_stream_core_module);

    if (cmcf->variables.nelts <= index) {
        ngx_log_error(NGX_LOG_ALERT, s->connection->log, 0,
                      "unknown variable index: %ui", index);
        return NULL;
    }

    if (s->variables[index].not_found || s->variables[index].valid) {
        return &s->variables[index];
    }

    v = cmcf->variables.elts;

    if (ngx_stream_variable_depth == 0) {
        ngx_log_error(NGX_LOG_ERR, s->connection->log, 0,
                      "cycle while evaluating variable \"%V\"",
                      &v[index].name);
        return NULL;
    }

    ngx_stream_variable_depth--;

    if (v[index].get_handler(s, &s->variables[index], v[index].data)
        == NGX_OK)
    {
        ngx_stream_variable_depth++;

        if (v[index].flags & NGX_STREAM_VAR_NOCACHEABLE) {
            s->variables[index].no_cacheable = 1;
        }

        return &s->variables[index];
    }

    ngx_stream_variable_depth++;

    s->variables[index].valid = 0;
    s->variables[index].not_found = 1;

    return NULL;
}


ngx_stream_variable_value_t *
ngx_stream_get_flushed_variable(ngx_stream_session_t *s, ngx_uint_t index)
{
    ngx_stream_variable_value_t  *v;

    v = &s->variables[index];

    if (v->valid || v->not_found) {
        if (!v->no_cacheable) {
            return v;
        }

        v->valid = 0;
        v->not_found = 0;
    }

    return ngx_stream_get_indexed_variable(s, index);
}


ngx_stream_variable_value_t *
ngx_stream_get_variable(ngx_stream_session_t *s, ngx_str_t *name,
    ngx_uint_t key)
{
    size_t                        len;
    ngx_uint_t                    i, n;
    ngx_stream_variable_t        *v;
    ngx_stream_variable_value_t  *vv;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_get_module_main_conf(s, ngx_stream_core_module);

    v = ngx_hash_find(&cmcf->variables_hash, key, name->data, name->len);

    if (v) {
        if (v->flags & NGX_STREAM_VAR_INDEXED) {
            return ngx_stream_get_flushed_variable(s, v->index);
        }

        if (ngx_stream_variable_depth == 0) {
            ngx_log_error(NGX_LOG_ERR, s->connection->log, 0,
                          "cycle while evaluating variable \"%V\"", name);
            return NULL;
        }

        ngx_stream_variable_depth--;

        vv = ngx_palloc(s->connection->pool,
                        sizeof(ngx_stream_variable_value_t));

        if (vv && v->get_handler(s, vv, v->data) == NGX_OK) {
            ngx_stream_variable_depth++;
            return vv;
        }

        ngx_stream_variable_depth++;
        return NULL;
    }

    vv = ngx_palloc(s->connection->pool, sizeof(ngx_stream_variable_value_t));
    if (vv == NULL) {
        return NULL;
    }

    len = 0;

    v = cmcf->prefix_variables.elts;
    n = cmcf->prefix_variables.nelts;

    for (i = 0; i < cmcf->prefix_variables.nelts; i++) {
        if (name->len >= v[i].name.len && name->len > len
            && ngx_strncmp(name->data, v[i].name.data, v[i].name.len) == 0)
        {
            len = v[i].name.len;
            n = i;
        }
    }

    if (n != cmcf->prefix_variables.nelts) {
        if (v[n].get_handler(s, vv, (uintptr_t) name) == NGX_OK) {
            return vv;
        }

        return NULL;
    }

    vv->not_found = 1;

    return vv;
}


static ngx_int_t
ngx_stream_variable_binary_remote_addr(ngx_stream_session_t *s,
     ngx_stream_variable_value_t *v, uintptr_t data)
{
    struct sockaddr_in   *sin;
#if (NGX_HAVE_INET6)
    struct sockaddr_in6  *sin6;
#endif

    switch (s->connection->sockaddr->sa_family) {

#if (NGX_HAVE_INET6)
    case AF_INET6:
        sin6 = (struct sockaddr_in6 *) s->connection->sockaddr;

        v->len = sizeof(struct in6_addr);
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = sin6->sin6_addr.s6_addr;

        break;
#endif

#if (NGX_HAVE_UNIX_DOMAIN)
    case AF_UNIX:

        v->len = s->connection->addr_text.len;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = s->connection->addr_text.data;

        break;
#endif

    default: /* AF_INET */
        sin = (struct sockaddr_in *) s->connection->sockaddr;

        v->len = sizeof(in_addr_t);
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = (u_char *) &sin->sin_addr;

        break;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_remote_addr(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    v->len = s->connection->addr_text.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = s->connection->addr_text.data;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_remote_port(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    ngx_uint_t  port;

    v->len = 0;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    v->data = ngx_pnalloc(s->connection->pool, sizeof("65535") - 1);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    port = ngx_inet_get_port(s->connection->sockaddr);

    if (port > 0 && port < 65536) {
        v->len = ngx_sprintf(v->data, "%ui", port) - v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_proxy_protocol_addr(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    ngx_str_t             *addr;
    ngx_proxy_protocol_t  *pp;

    pp = s->connection->proxy_protocol;
    if (pp == NULL) {
        v->not_found = 1;
        return NGX_OK;
    }

    addr = (ngx_str_t *) ((char *) pp + data);

    v->len = addr->len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = addr->data;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_proxy_protocol_port(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    ngx_uint_t             port;
    ngx_proxy_protocol_t  *pp;

    pp = s->connection->proxy_protocol;
    if (pp == NULL) {
        v->not_found = 1;
        return NGX_OK;
    }

    v->len = 0;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    v->data = ngx_pnalloc(s->connection->pool, sizeof("65535") - 1);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    port = *(in_port_t *) ((char *) pp + data);

    if (port > 0 && port < 65536) {
        v->len = ngx_sprintf(v->data, "%ui", port) - v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_server_addr(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    ngx_str_t  str;
    u_char     addr[NGX_SOCKADDR_STRLEN];

    str.len = NGX_SOCKADDR_STRLEN;
    str.data = addr;

    if (ngx_connection_local_sockaddr(s->connection, &str, 0) != NGX_OK) {
        return NGX_ERROR;
    }

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

    ngx_memcpy(str.data, addr, str.len);

    v->len = str.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = str.data;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_server_port(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    ngx_uint_t  port;

    v->len = 0;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    if (ngx_connection_local_sockaddr(s->connection, NULL, 0) != NGX_OK) {
        return NGX_ERROR;
    }

    v->data = ngx_pnalloc(s->connection->pool, sizeof("65535") - 1);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    port = ngx_inet_get_port(s->connection->local_sockaddr);

    if (port > 0 && port < 65536) {
        v->len = ngx_sprintf(v->data, "%ui", port) - v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_bytes(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(s->connection->pool, NGX_OFF_T_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    if (data == 1) {
        v->len = ngx_sprintf(p, "%O", s->received) - p;

    } else {
        v->len = ngx_sprintf(p, "%O", s->connection->sent) - p;
    }

    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_session_time(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    u_char          *p;
    ngx_time_t      *tp;
    ngx_msec_int_t   ms;

    p = ngx_pnalloc(s->connection->pool, NGX_TIME_T_LEN + 4);
    if (p == NULL) {
        return NGX_ERROR;
    }

    tp = ngx_timeofday();

    ms = (ngx_msec_int_t)
             ((tp->sec - s->start_sec) * 1000 + (tp->msec - s->start_msec));
    ms = ngx_max(ms, 0);

    v->len = ngx_sprintf(p, "%T.%03M", (time_t) ms / 1000, ms % 1000) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_status(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    v->data = ngx_pnalloc(s->connection->pool, NGX_INT_T_LEN);
    if (v->data == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(v->data, "%03ui", s->status) - v->data;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_connection(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(s->connection->pool, NGX_ATOMIC_T_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(p, "%uA", s->connection->number) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_nginx_version(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    v->len = sizeof(NGINX_VERSION) - 1;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = (u_char *) NGINX_VERSION;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_hostname(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    v->len = ngx_cycle->hostname.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = ngx_cycle->hostname.data;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_pid(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(s->connection->pool, NGX_INT64_LEN);
    if (p == NULL) {
        return NGX_ERROR;
    }

    v->len = ngx_sprintf(p, "%P", ngx_pid) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_msec(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    u_char      *p;
    ngx_time_t  *tp;

    p = ngx_pnalloc(s->connection->pool, NGX_TIME_T_LEN + 4);
    if (p == NULL) {
        return NGX_ERROR;
    }

    tp = ngx_timeofday();

    v->len = ngx_sprintf(p, "%T.%03M", tp->sec, tp->msec) - p;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_time_iso8601(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(s->connection->pool, ngx_cached_http_log_iso8601.len);
    if (p == NULL) {
        return NGX_ERROR;
    }

    ngx_memcpy(p, ngx_cached_http_log_iso8601.data,
               ngx_cached_http_log_iso8601.len);

    v->len = ngx_cached_http_log_iso8601.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_time_local(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    u_char  *p;

    p = ngx_pnalloc(s->connection->pool, ngx_cached_http_log_time.len);
    if (p == NULL) {
        return NGX_ERROR;
    }

    ngx_memcpy(p, ngx_cached_http_log_time.data, ngx_cached_http_log_time.len);

    v->len = ngx_cached_http_log_time.len;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = p;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_variable_protocol(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    v->len = 3;
    v->valid = 1;
    v->no_cacheable = 0;
    v->not_found = 0;
    v->data = (u_char *) (s->connection->type == SOCK_DGRAM ? "UDP" : "TCP");

    return NGX_OK;
}


void *
ngx_stream_map_find(ngx_stream_session_t *s, ngx_stream_map_t *map,
    ngx_str_t *match)
{
    void        *value;
    u_char      *low;
    size_t       len;
    ngx_uint_t   key;

    len = match->len;

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

    } else {
        low = NULL;
    }

    key = ngx_hash_strlow(low, match->data, len);

    value = ngx_hash_find_combined(&map->hash, key, low, len);
    if (value) {
        return value;
    }

#if (NGX_PCRE)

    if (len && map->nregex) {
        ngx_int_t                n;
        ngx_uint_t               i;
        ngx_stream_map_regex_t  *reg;

        reg = map->regex;

        for (i = 0; i < map->nregex; i++) {

            n = ngx_stream_regex_exec(s, reg[i].regex, match);

            if (n == NGX_OK) {
                return reg[i].value;
            }

            if (n == NGX_DECLINED) {
                continue;
            }

            /* NGX_ERROR */

            return NULL;
        }
    }

#endif

    return NULL;
}


#if (NGX_PCRE)

static ngx_int_t
ngx_stream_variable_not_found(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    v->not_found = 1;
    return NGX_OK;
}


ngx_stream_regex_t *
ngx_stream_regex_compile(ngx_conf_t *cf, ngx_regex_compile_t *rc)
{
    u_char                       *p;
    size_t                        size;
    ngx_str_t                     name;
    ngx_uint_t                    i, n;
    ngx_stream_variable_t        *v;
    ngx_stream_regex_t           *re;
    ngx_stream_regex_variable_t  *rv;
    ngx_stream_core_main_conf_t  *cmcf;

    rc->pool = cf->pool;

    if (ngx_regex_compile(rc) != NGX_OK) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%V", &rc->err);
        return NULL;
    }

    re = ngx_pcalloc(cf->pool, sizeof(ngx_stream_regex_t));
    if (re == NULL) {
        return NULL;
    }

    re->regex = rc->regex;
    re->ncaptures = rc->captures;
    re->name = rc->pattern;

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);
    cmcf->ncaptures = ngx_max(cmcf->ncaptures, re->ncaptures);

    n = (ngx_uint_t) rc->named_captures;

    if (n == 0) {
        return re;
    }

    rv = ngx_palloc(rc->pool, n * sizeof(ngx_stream_regex_variable_t));
    if (rv == NULL) {
        return NULL;
    }

    re->variables = rv;
    re->nvariables = n;

    size = rc->name_size;
    p = rc->names;

    for (i = 0; i < n; i++) {
        rv[i].capture = 2 * ((p[0] << 8) + p[1]);

        name.data = &p[2];
        name.len = ngx_strlen(name.data);

        v = ngx_stream_add_variable(cf, &name, NGX_STREAM_VAR_CHANGEABLE);
        if (v == NULL) {
            return NULL;
        }

        rv[i].index = ngx_stream_get_variable_index(cf, &name);
        if (rv[i].index == NGX_ERROR) {
            return NULL;
        }

        v->get_handler = ngx_stream_variable_not_found;

        p += size;
    }

    return re;
}


ngx_int_t
ngx_stream_regex_exec(ngx_stream_session_t *s, ngx_stream_regex_t *re,
    ngx_str_t *str)
{
    ngx_int_t                     rc, index;
    ngx_uint_t                    i, n, len;
    ngx_stream_variable_value_t  *vv;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_get_module_main_conf(s, ngx_stream_core_module);

    if (re->ncaptures) {
        len = cmcf->ncaptures;

        if (s->captures == NULL) {
            s->captures = ngx_palloc(s->connection->pool, len * sizeof(int));
            if (s->captures == NULL) {
                return NGX_ERROR;
            }
        }

    } else {
        len = 0;
    }

    rc = ngx_regex_exec(re->regex, str, s->captures, len);

    if (rc == NGX_REGEX_NO_MATCHED) {
        return NGX_DECLINED;
    }

    if (rc < 0) {
        ngx_log_error(NGX_LOG_ALERT, s->connection->log, 0,
                      ngx_regex_exec_n " failed: %i on \"%V\" using \"%V\"",
                      rc, str, &re->name);
        return NGX_ERROR;
    }

    for (i = 0; i < re->nvariables; i++) {

        n = re->variables[i].capture;
        index = re->variables[i].index;
        vv = &s->variables[index];

        vv->len = s->captures[n + 1] - s->captures[n];
        vv->valid = 1;
        vv->no_cacheable = 0;
        vv->not_found = 0;
        vv->data = &str->data[s->captures[n]];

#if (NGX_DEBUG)
        {
        ngx_stream_variable_t  *v;

        v = cmcf->variables.elts;

        ngx_log_debug2(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                       "stream regex set $%V to \"%v\"", &v[index].name, vv);
        }
#endif
    }

    s->ncaptures = rc * 2;
    s->captures_data = str->data;

    return NGX_OK;
}

#endif


ngx_int_t
ngx_stream_variables_add_core_vars(ngx_conf_t *cf)
{
    ngx_stream_variable_t        *cv, *v;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);

    cmcf->variables_keys = ngx_pcalloc(cf->temp_pool,
                                       sizeof(ngx_hash_keys_arrays_t));
    if (cmcf->variables_keys == NULL) {
        return NGX_ERROR;
    }

    cmcf->variables_keys->pool = cf->pool;
    cmcf->variables_keys->temp_pool = cf->pool;

    if (ngx_hash_keys_array_init(cmcf->variables_keys, NGX_HASH_SMALL)
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    if (ngx_array_init(&cmcf->prefix_variables, cf->pool, 8,
                       sizeof(ngx_stream_variable_t))
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    for (cv = ngx_stream_core_variables; cv->name.len; cv++) {
        v = ngx_stream_add_variable(cf, &cv->name, cv->flags);
        if (v == NULL) {
            return NGX_ERROR;
        }

        *v = *cv;
    }

    return NGX_OK;
}


ngx_int_t
ngx_stream_variables_init_vars(ngx_conf_t *cf)
{
    size_t                        len;
    ngx_uint_t                    i, n;
    ngx_hash_key_t               *key;
    ngx_hash_init_t               hash;
    ngx_stream_variable_t        *v, *av, *pv;
    ngx_stream_core_main_conf_t  *cmcf;

    /* set the handlers for the indexed stream variables */

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);

    v = cmcf->variables.elts;
    pv = cmcf->prefix_variables.elts;
    key = cmcf->variables_keys->keys.elts;

    for (i = 0; i < cmcf->variables.nelts; i++) {

        for (n = 0; n < cmcf->variables_keys->keys.nelts; n++) {

            av = key[n].value;

            if (v[i].name.len == key[n].key.len
                && ngx_strncmp(v[i].name.data, key[n].key.data, v[i].name.len)
                   == 0)
            {
                v[i].get_handler = av->get_handler;
                v[i].data = av->data;

                av->flags |= NGX_STREAM_VAR_INDEXED;
                v[i].flags = av->flags;

                av->index = i;

                if (av->get_handler == NULL
                    || (av->flags & NGX_STREAM_VAR_WEAK))
                {
                    break;
                }

                goto next;
            }
        }

        len = 0;
        av = NULL;

        for (n = 0; n < cmcf->prefix_variables.nelts; n++) {
            if (v[i].name.len >= pv[n].name.len && v[i].name.len > len
                && ngx_strncmp(v[i].name.data, pv[n].name.data, pv[n].name.len)
                   == 0)
            {
                av = &pv[n];
                len = pv[n].name.len;
            }
        }

        if (av) {
            v[i].get_handler = av->get_handler;
            v[i].data = (uintptr_t) &v[i].name;
            v[i].flags = av->flags;

            goto next;
         }

        if (v[i].get_handler == NULL) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "unknown \"%V\" variable", &v[i].name);
            return NGX_ERROR;
        }

    next:
        continue;
    }


    for (n = 0; n < cmcf->variables_keys->keys.nelts; n++) {
        av = key[n].value;

        if (av->flags & NGX_STREAM_VAR_NOHASH) {
            key[n].key.data = NULL;
        }
    }


    hash.hash = &cmcf->variables_hash;
    hash.key = ngx_hash_key;
    hash.max_size = cmcf->variables_hash_max_size;
    hash.bucket_size = cmcf->variables_hash_bucket_size;
    hash.name = "variables_hash";
    hash.pool = cf->pool;
    hash.temp_pool = NULL;

    if (ngx_hash_init(&hash, cmcf->variables_keys->keys.elts,
                      cmcf->variables_keys->keys.nelts)
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    cmcf->variables_keys = NULL;

    return NGX_OK;
}