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view src/stream/ngx_stream_proxy_module.c @ 6435:d1c791479bbb

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Stream: post first read events from client and upstream. The main proxy function ngx_stream_proxy_process() can terminate the stream session. The code, following it, should check its return code to make sure the session still exists. This happens in client and upstream initialization functions. Swapping ngx_stream_proxy_process() call with the code, that follows it, leaves the same problem vice versa. In future ngx_stream_proxy_process() will call ngx_stream_proxy_next_upstream() making it too complicated to know if stream session still exists after this call. Now ngx_stream_proxy_process() is called from posted event handlers in both places with no code following it. The posted event is automatically removed once session is terminated.
author Roman Arutyunyan <arut@nginx.com>
date Tue, 15 Mar 2016 15:55:23 +0300
parents 70e6e1f12dee
children 8f038068f4bc
line wrap: on
line source


/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


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


typedef struct {
    ngx_msec_t                       connect_timeout;
    ngx_msec_t                       timeout;
    ngx_msec_t                       next_upstream_timeout;
    size_t                           buffer_size;
    size_t                           upload_rate;
    size_t                           download_rate;
    ngx_uint_t                       next_upstream_tries;
    ngx_flag_t                       next_upstream;
    ngx_flag_t                       proxy_protocol;
    ngx_addr_t                      *local;

#if (NGX_STREAM_SSL)
    ngx_flag_t                       ssl_enable;
    ngx_flag_t                       ssl_session_reuse;
    ngx_uint_t                       ssl_protocols;
    ngx_str_t                        ssl_ciphers;
    ngx_str_t                        ssl_name;
    ngx_flag_t                       ssl_server_name;

    ngx_flag_t                       ssl_verify;
    ngx_uint_t                       ssl_verify_depth;
    ngx_str_t                        ssl_trusted_certificate;
    ngx_str_t                        ssl_crl;
    ngx_str_t                        ssl_certificate;
    ngx_str_t                        ssl_certificate_key;
    ngx_array_t                     *ssl_passwords;

    ngx_ssl_t                       *ssl;
#endif

    ngx_stream_upstream_srv_conf_t  *upstream;
} ngx_stream_proxy_srv_conf_t;


static void ngx_stream_proxy_handler(ngx_stream_session_t *s);
static void ngx_stream_proxy_connect(ngx_stream_session_t *s);
static void ngx_stream_proxy_init_upstream(ngx_stream_session_t *s);
static void ngx_stream_proxy_upstream_handler(ngx_event_t *ev);
static void ngx_stream_proxy_downstream_handler(ngx_event_t *ev);
static void ngx_stream_proxy_process_connection(ngx_event_t *ev,
    ngx_uint_t from_upstream);
static void ngx_stream_proxy_connect_handler(ngx_event_t *ev);
static ngx_int_t ngx_stream_proxy_test_connect(ngx_connection_t *c);
static void ngx_stream_proxy_process(ngx_stream_session_t *s,
    ngx_uint_t from_upstream, ngx_uint_t do_write);
static void ngx_stream_proxy_next_upstream(ngx_stream_session_t *s);
static void ngx_stream_proxy_finalize(ngx_stream_session_t *s, ngx_int_t rc);
static u_char *ngx_stream_proxy_log_error(ngx_log_t *log, u_char *buf,
    size_t len);

static void *ngx_stream_proxy_create_srv_conf(ngx_conf_t *cf);
static char *ngx_stream_proxy_merge_srv_conf(ngx_conf_t *cf, void *parent,
    void *child);
static char *ngx_stream_proxy_pass(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static char *ngx_stream_proxy_bind(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static ngx_int_t ngx_stream_proxy_send_proxy_protocol(ngx_stream_session_t *s);

#if (NGX_STREAM_SSL)

static char *ngx_stream_proxy_ssl_password_file(ngx_conf_t *cf,
    ngx_command_t *cmd, void *conf);
static void ngx_stream_proxy_ssl_init_connection(ngx_stream_session_t *s);
static void ngx_stream_proxy_ssl_handshake(ngx_connection_t *pc);
static ngx_int_t ngx_stream_proxy_ssl_name(ngx_stream_session_t *s);
static ngx_int_t ngx_stream_proxy_set_ssl(ngx_conf_t *cf,
    ngx_stream_proxy_srv_conf_t *pscf);


static ngx_conf_bitmask_t  ngx_stream_proxy_ssl_protocols[] = {
    { ngx_string("SSLv2"), NGX_SSL_SSLv2 },
    { ngx_string("SSLv3"), NGX_SSL_SSLv3 },
    { ngx_string("TLSv1"), NGX_SSL_TLSv1 },
    { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 },
    { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 },
    { ngx_null_string, 0 }
};

#endif


static ngx_conf_deprecated_t  ngx_conf_deprecated_proxy_downstream_buffer = {
    ngx_conf_deprecated, "proxy_downstream_buffer", "proxy_buffer_size"
};

static ngx_conf_deprecated_t  ngx_conf_deprecated_proxy_upstream_buffer = {
    ngx_conf_deprecated, "proxy_upstream_buffer", "proxy_buffer_size"
};


static ngx_command_t  ngx_stream_proxy_commands[] = {

    { ngx_string("proxy_pass"),
      NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_stream_proxy_pass,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("proxy_bind"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_stream_proxy_bind,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("proxy_connect_timeout"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, connect_timeout),
      NULL },

    { ngx_string("proxy_timeout"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, timeout),
      NULL },

    { ngx_string("proxy_buffer_size"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, buffer_size),
      NULL },

    { ngx_string("proxy_downstream_buffer"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, buffer_size),
      &ngx_conf_deprecated_proxy_downstream_buffer },

    { ngx_string("proxy_upstream_buffer"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, buffer_size),
      &ngx_conf_deprecated_proxy_upstream_buffer },

    { ngx_string("proxy_upload_rate"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, upload_rate),
      NULL },

    { ngx_string("proxy_download_rate"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, download_rate),
      NULL },

    { ngx_string("proxy_next_upstream"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, next_upstream),
      NULL },

    { ngx_string("proxy_next_upstream_tries"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, next_upstream_tries),
      NULL },

    { ngx_string("proxy_next_upstream_timeout"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, next_upstream_timeout),
      NULL },

    { ngx_string("proxy_protocol"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, proxy_protocol),
      NULL },

#if (NGX_STREAM_SSL)

    { ngx_string("proxy_ssl"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_enable),
      NULL },

    { ngx_string("proxy_ssl_session_reuse"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_session_reuse),
      NULL },

    { ngx_string("proxy_ssl_protocols"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_1MORE,
      ngx_conf_set_bitmask_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_protocols),
      &ngx_stream_proxy_ssl_protocols },

    { ngx_string("proxy_ssl_ciphers"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_ciphers),
      NULL },

    { ngx_string("proxy_ssl_name"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_name),
      NULL },

    { ngx_string("proxy_ssl_server_name"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_server_name),
      NULL },

    { ngx_string("proxy_ssl_verify"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_verify),
      NULL },

    { ngx_string("proxy_ssl_verify_depth"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_verify_depth),
      NULL },

    { ngx_string("proxy_ssl_trusted_certificate"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_trusted_certificate),
      NULL },

    { ngx_string("proxy_ssl_crl"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_crl),
      NULL },

    { ngx_string("proxy_ssl_certificate"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_certificate),
      NULL },

    { ngx_string("proxy_ssl_certificate_key"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_str_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_stream_proxy_srv_conf_t, ssl_certificate_key),
      NULL },

    { ngx_string("proxy_ssl_password_file"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_stream_proxy_ssl_password_file,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

#endif

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_proxy_module_ctx = {
    NULL,                                  /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    ngx_stream_proxy_create_srv_conf,      /* create server configuration */
    ngx_stream_proxy_merge_srv_conf        /* merge server configuration */
};


ngx_module_t  ngx_stream_proxy_module = {
    NGX_MODULE_V1,
    &ngx_stream_proxy_module_ctx,          /* module context */
    ngx_stream_proxy_commands,             /* module directives */
    NGX_STREAM_MODULE,                     /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static void
ngx_stream_proxy_handler(ngx_stream_session_t *s)
{
    u_char                          *p;
    ngx_connection_t                *c;
    ngx_stream_upstream_t           *u;
    ngx_stream_proxy_srv_conf_t     *pscf;
    ngx_stream_upstream_srv_conf_t  *uscf;

    c = s->connection;

    pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

    ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                   "proxy connection handler");

    u = ngx_pcalloc(c->pool, sizeof(ngx_stream_upstream_t));
    if (u == NULL) {
        ngx_stream_proxy_finalize(s, NGX_ERROR);
        return;
    }

    s->upstream = u;

    s->log_handler = ngx_stream_proxy_log_error;

    u->peer.log = c->log;
    u->peer.log_error = NGX_ERROR_ERR;

    u->peer.local = pscf->local;

    uscf = pscf->upstream;

    if (uscf->peer.init(s, uscf) != NGX_OK) {
        ngx_stream_proxy_finalize(s, NGX_ERROR);
        return;
    }

    u->peer.start_time = ngx_current_msec;

    if (pscf->next_upstream_tries
        && u->peer.tries > pscf->next_upstream_tries)
    {
        u->peer.tries = pscf->next_upstream_tries;
    }

    u->proxy_protocol = pscf->proxy_protocol;
    u->start_sec = ngx_time();

    p = ngx_pnalloc(c->pool, pscf->buffer_size);
    if (p == NULL) {
        ngx_stream_proxy_finalize(s, NGX_ERROR);
        return;
    }

    u->downstream_buf.start = p;
    u->downstream_buf.end = p + pscf->buffer_size;
    u->downstream_buf.pos = p;
    u->downstream_buf.last = p;

    c->write->handler = ngx_stream_proxy_downstream_handler;
    c->read->handler = ngx_stream_proxy_downstream_handler;

    if (u->proxy_protocol
#if (NGX_STREAM_SSL)
        && pscf->ssl == NULL
#endif
        && pscf->buffer_size >= NGX_PROXY_PROTOCOL_MAX_HEADER)
    {
        /* optimization for a typical case */

        ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                       "stream proxy send PROXY protocol header");

        p = ngx_proxy_protocol_write(c, u->downstream_buf.last,
                                     u->downstream_buf.end);
        if (p == NULL) {
            ngx_stream_proxy_finalize(s, NGX_ERROR);
            return;
        }

        u->downstream_buf.last = p;
        u->proxy_protocol = 0;
    }

    if (c->read->ready) {
        ngx_post_event(c->read, &ngx_posted_events);
    }

    ngx_stream_proxy_connect(s);
}


static void
ngx_stream_proxy_connect(ngx_stream_session_t *s)
{
    ngx_int_t                     rc;
    ngx_connection_t             *c, *pc;
    ngx_stream_upstream_t        *u;
    ngx_stream_proxy_srv_conf_t  *pscf;

    c = s->connection;

    c->log->action = "connecting to upstream";

    u = s->upstream;

    rc = ngx_event_connect_peer(&u->peer);

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "proxy connect: %i", rc);

    if (rc == NGX_ERROR) {
        ngx_stream_proxy_finalize(s, NGX_ERROR);
        return;
    }

    if (rc == NGX_BUSY) {
        ngx_log_error(NGX_LOG_ERR, c->log, 0, "no live upstreams");
        ngx_stream_proxy_finalize(s, NGX_DECLINED);
        return;
    }

    if (rc == NGX_DECLINED) {
        ngx_stream_proxy_next_upstream(s);
        return;
    }

    /* rc == NGX_OK || rc == NGX_AGAIN || rc == NGX_DONE */

    pc = u->peer.connection;

    pc->data = s;
    pc->log = c->log;
    pc->pool = c->pool;
    pc->read->log = c->log;
    pc->write->log = c->log;

    if (rc != NGX_AGAIN) {
        ngx_stream_proxy_init_upstream(s);
        return;
    }

    pc->read->handler = ngx_stream_proxy_connect_handler;
    pc->write->handler = ngx_stream_proxy_connect_handler;

    pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

    ngx_add_timer(pc->write, pscf->connect_timeout);
}


static void
ngx_stream_proxy_init_upstream(ngx_stream_session_t *s)
{
    int                           tcp_nodelay;
    u_char                       *p;
    ngx_connection_t             *c, *pc;
    ngx_log_handler_pt            handler;
    ngx_stream_upstream_t        *u;
    ngx_stream_core_srv_conf_t   *cscf;
    ngx_stream_proxy_srv_conf_t  *pscf;

    u = s->upstream;
    pc = u->peer.connection;

    cscf = ngx_stream_get_module_srv_conf(s, ngx_stream_core_module);

    if (cscf->tcp_nodelay && pc->tcp_nodelay == NGX_TCP_NODELAY_UNSET) {
        ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, "tcp_nodelay");

        tcp_nodelay = 1;

        if (setsockopt(pc->fd, IPPROTO_TCP, TCP_NODELAY,
                       (const void *) &tcp_nodelay, sizeof(int)) == -1)
        {
            ngx_connection_error(pc, ngx_socket_errno,
                                 "setsockopt(TCP_NODELAY) failed");
            ngx_stream_proxy_next_upstream(s);
            return;
        }

        pc->tcp_nodelay = NGX_TCP_NODELAY_SET;
    }

    if (u->proxy_protocol) {
        if (ngx_stream_proxy_send_proxy_protocol(s) != NGX_OK) {
            return;
        }

        u->proxy_protocol = 0;
    }

    pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

#if (NGX_STREAM_SSL)
    if (pscf->ssl && pc->ssl == NULL) {
        ngx_stream_proxy_ssl_init_connection(s);
        return;
    }
#endif

    c = s->connection;

    if (c->log->log_level >= NGX_LOG_INFO) {
        ngx_str_t  str;
        u_char     addr[NGX_SOCKADDR_STRLEN];

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

        if (ngx_connection_local_sockaddr(pc, &str, 1) == NGX_OK) {
            handler = c->log->handler;
            c->log->handler = NULL;

            ngx_log_error(NGX_LOG_INFO, c->log, 0, "proxy %V connected to %V",
                          &str, u->peer.name);

            c->log->handler = handler;
        }
    }

    c->log->action = "proxying connection";

    p = ngx_pnalloc(c->pool, pscf->buffer_size);
    if (p == NULL) {
        ngx_stream_proxy_finalize(s, NGX_ERROR);
        return;
    }

    u->upstream_buf.start = p;
    u->upstream_buf.end = p + pscf->buffer_size;
    u->upstream_buf.pos = p;
    u->upstream_buf.last = p;

    u->connected = 1;

    pc->read->handler = ngx_stream_proxy_upstream_handler;
    pc->write->handler = ngx_stream_proxy_upstream_handler;

    if (pc->read->ready) {
        ngx_post_event(pc->read, &ngx_posted_events);
    }

    ngx_stream_proxy_process(s, 0, 1);
}


static ngx_int_t
ngx_stream_proxy_send_proxy_protocol(ngx_stream_session_t *s)
{
    u_char                       *p;
    ssize_t                       n, size;
    ngx_connection_t             *c, *pc;
    ngx_stream_upstream_t        *u;
    ngx_stream_proxy_srv_conf_t  *pscf;
    u_char                        buf[NGX_PROXY_PROTOCOL_MAX_HEADER];

    c = s->connection;

    ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                   "stream proxy send PROXY protocol header");

    p = ngx_proxy_protocol_write(c, buf, buf + NGX_PROXY_PROTOCOL_MAX_HEADER);
    if (p == NULL) {
        ngx_stream_proxy_finalize(s, NGX_ERROR);
        return NGX_ERROR;
    }

    u = s->upstream;

    pc = u->peer.connection;

    size = p - buf;

    n = pc->send(pc, buf, size);

    if (n == NGX_AGAIN) {
        if (ngx_handle_write_event(pc->write, 0) != NGX_OK) {
            ngx_stream_proxy_finalize(s, NGX_ERROR);
            return NGX_ERROR;
        }

        pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

        ngx_add_timer(pc->write, pscf->timeout);

        pc->write->handler = ngx_stream_proxy_connect_handler;

        return NGX_AGAIN;
    }

    if (n == NGX_ERROR) {
        ngx_stream_proxy_finalize(s, NGX_DECLINED);
        return NGX_ERROR;
    }

    if (n != size) {

        /*
         * PROXY protocol specification:
         * The sender must always ensure that the header
         * is sent at once, so that the transport layer
         * maintains atomicity along the path to the receiver.
         */

        ngx_log_error(NGX_LOG_ERR, c->log, 0,
                      "could not send PROXY protocol header at once");

        ngx_stream_proxy_finalize(s, NGX_DECLINED);

        return NGX_ERROR;
    }

    return NGX_OK;
}


#if (NGX_STREAM_SSL)

static char *
ngx_stream_proxy_ssl_password_file(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf)
{
    ngx_stream_proxy_srv_conf_t *pscf = conf;

    ngx_str_t  *value;

    if (pscf->ssl_passwords != NGX_CONF_UNSET_PTR) {
        return "is duplicate";
    }

    value = cf->args->elts;

    pscf->ssl_passwords = ngx_ssl_read_password_file(cf, &value[1]);

    if (pscf->ssl_passwords == NULL) {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static void
ngx_stream_proxy_ssl_init_connection(ngx_stream_session_t *s)
{
    ngx_int_t                     rc;
    ngx_connection_t             *pc;
    ngx_stream_upstream_t        *u;
    ngx_stream_proxy_srv_conf_t  *pscf;

    u = s->upstream;

    pc = u->peer.connection;

    pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

    if (ngx_ssl_create_connection(pscf->ssl, pc, NGX_SSL_BUFFER|NGX_SSL_CLIENT)
        != NGX_OK)
    {
        ngx_stream_proxy_finalize(s, NGX_ERROR);
        return;
    }

    if (pscf->ssl_server_name || pscf->ssl_verify) {
        if (ngx_stream_proxy_ssl_name(s) != NGX_OK) {
            ngx_stream_proxy_finalize(s, NGX_ERROR);
            return;
        }
    }

    if (pscf->ssl_session_reuse) {
        if (u->peer.set_session(&u->peer, u->peer.data) != NGX_OK) {
            ngx_stream_proxy_finalize(s, NGX_ERROR);
            return;
        }
    }

    s->connection->log->action = "SSL handshaking to upstream";

    rc = ngx_ssl_handshake(pc);

    if (rc == NGX_AGAIN) {

        if (!pc->write->timer_set) {
            ngx_add_timer(pc->write, pscf->connect_timeout);
        }

        pc->ssl->handler = ngx_stream_proxy_ssl_handshake;
        return;
    }

    ngx_stream_proxy_ssl_handshake(pc);
}


static void
ngx_stream_proxy_ssl_handshake(ngx_connection_t *pc)
{
    long                          rc;
    ngx_stream_session_t         *s;
    ngx_stream_upstream_t        *u;
    ngx_stream_proxy_srv_conf_t  *pscf;

    s = pc->data;

    pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

    if (pc->ssl->handshaked) {

        if (pscf->ssl_verify) {
            rc = SSL_get_verify_result(pc->ssl->connection);

            if (rc != X509_V_OK) {
                ngx_log_error(NGX_LOG_ERR, pc->log, 0,
                              "upstream SSL certificate verify error: (%l:%s)",
                              rc, X509_verify_cert_error_string(rc));
                goto failed;
            }

            u = s->upstream;

            if (ngx_ssl_check_host(pc, &u->ssl_name) != NGX_OK) {
                ngx_log_error(NGX_LOG_ERR, pc->log, 0,
                              "upstream SSL certificate does not match \"%V\"",
                              &u->ssl_name);
                goto failed;
            }
        }

        if (pscf->ssl_session_reuse) {
            u = s->upstream;
            u->peer.save_session(&u->peer, u->peer.data);
        }

        if (pc->write->timer_set) {
            ngx_del_timer(pc->write);
        }

        ngx_stream_proxy_init_upstream(s);

        return;
    }

failed:

    ngx_stream_proxy_next_upstream(s);
}


static ngx_int_t
ngx_stream_proxy_ssl_name(ngx_stream_session_t *s)
{
    u_char                       *p, *last;
    ngx_str_t                     name;
    ngx_stream_upstream_t        *u;
    ngx_stream_proxy_srv_conf_t  *pscf;

    pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

    u = s->upstream;

    name = pscf->ssl_name;

    if (name.len == 0) {
        name = pscf->upstream->host;
    }

    if (name.len == 0) {
        goto done;
    }

    /*
     * ssl name here may contain port, strip it for compatibility
     * with the http module
     */

    p = name.data;
    last = name.data + name.len;

    if (*p == '[') {
        p = ngx_strlchr(p, last, ']');

        if (p == NULL) {
            p = name.data;
        }
    }

    p = ngx_strlchr(p, last, ':');

    if (p != NULL) {
        name.len = p - name.data;
    }

    if (!pscf->ssl_server_name) {
        goto done;
    }

#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME

    /* as per RFC 6066, literal IPv4 and IPv6 addresses are not permitted */

    if (name.len == 0 || *name.data == '[') {
        goto done;
    }

    if (ngx_inet_addr(name.data, name.len) != INADDR_NONE) {
        goto done;
    }

    /*
     * SSL_set_tlsext_host_name() needs a null-terminated string,
     * hence we explicitly null-terminate name here
     */

    p = ngx_pnalloc(s->connection->pool, name.len + 1);
    if (p == NULL) {
        return NGX_ERROR;
    }

    (void) ngx_cpystrn(p, name.data, name.len + 1);

    name.data = p;

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                   "upstream SSL server name: \"%s\"", name.data);

    if (SSL_set_tlsext_host_name(u->peer.connection->ssl->connection, name.data)
        == 0)
    {
        ngx_ssl_error(NGX_LOG_ERR, s->connection->log, 0,
                      "SSL_set_tlsext_host_name(\"%s\") failed", name.data);
        return NGX_ERROR;
    }

#endif

done:

    u->ssl_name = name;

    return NGX_OK;
}

#endif


static void
ngx_stream_proxy_downstream_handler(ngx_event_t *ev)
{
    ngx_stream_proxy_process_connection(ev, ev->write);
}


static void
ngx_stream_proxy_upstream_handler(ngx_event_t *ev)
{
    ngx_stream_proxy_process_connection(ev, !ev->write);
}


static void
ngx_stream_proxy_process_connection(ngx_event_t *ev, ngx_uint_t from_upstream)
{
    ngx_connection_t             *c, *pc;
    ngx_stream_session_t         *s;
    ngx_stream_upstream_t        *u;
    ngx_stream_proxy_srv_conf_t  *pscf;

    c = ev->data;
    s = c->data;
    u = s->upstream;

    if (ev->timedout) {

        if (ev->delayed) {

            ev->timedout = 0;
            ev->delayed = 0;

            if (!ev->ready) {
                if (ngx_handle_read_event(ev, 0) != NGX_OK) {
                    ngx_stream_proxy_finalize(s, NGX_ERROR);
                    return;
                }

                if (u->connected) {
                    pc = u->peer.connection;

                    if (!c->read->delayed && !pc->read->delayed) {
                        pscf = ngx_stream_get_module_srv_conf(s,
                                                       ngx_stream_proxy_module);
                        ngx_add_timer(c->write, pscf->timeout);
                    }
                }

                return;
            }

        } else {
            ngx_connection_error(c, NGX_ETIMEDOUT, "connection timed out");
            ngx_stream_proxy_finalize(s, NGX_DECLINED);
            return;
        }

    } else if (ev->delayed) {

        ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                       "stream connection delayed");

        if (ngx_handle_read_event(ev, 0) != NGX_OK) {
            ngx_stream_proxy_finalize(s, NGX_ERROR);
        }

        return;
    }

    if (from_upstream && !u->connected) {
        return;
    }

    ngx_stream_proxy_process(s, from_upstream, ev->write);
}


static void
ngx_stream_proxy_connect_handler(ngx_event_t *ev)
{
    ngx_connection_t      *c;
    ngx_stream_session_t  *s;

    c = ev->data;
    s = c->data;

    if (ev->timedout) {
        ngx_log_error(NGX_LOG_ERR, c->log, NGX_ETIMEDOUT, "upstream timed out");
        ngx_stream_proxy_next_upstream(s);
        return;
    }

    ngx_del_timer(c->write);

    ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0,
                   "stream proxy connect upstream");

    if (ngx_stream_proxy_test_connect(c) != NGX_OK) {
        ngx_stream_proxy_next_upstream(s);
        return;
    }

    ngx_stream_proxy_init_upstream(s);
}


static ngx_int_t
ngx_stream_proxy_test_connect(ngx_connection_t *c)
{
    int        err;
    socklen_t  len;

#if (NGX_HAVE_KQUEUE)

    if (ngx_event_flags & NGX_USE_KQUEUE_EVENT)  {
        err = c->write->kq_errno ? c->write->kq_errno : c->read->kq_errno;

        if (err) {
            (void) ngx_connection_error(c, err,
                                    "kevent() reported that connect() failed");
            return NGX_ERROR;
        }

    } else
#endif
    {
        err = 0;
        len = sizeof(int);

        /*
         * BSDs and Linux return 0 and set a pending error in err
         * Solaris returns -1 and sets errno
         */

        if (getsockopt(c->fd, SOL_SOCKET, SO_ERROR, (void *) &err, &len)
            == -1)
        {
            err = ngx_socket_errno;
        }

        if (err) {
            (void) ngx_connection_error(c, err, "connect() failed");
            return NGX_ERROR;
        }
    }

    return NGX_OK;
}


static void
ngx_stream_proxy_process(ngx_stream_session_t *s, ngx_uint_t from_upstream,
    ngx_uint_t do_write)
{
    off_t                        *received, limit;
    size_t                        size, limit_rate;
    ssize_t                       n;
    ngx_buf_t                    *b;
    ngx_uint_t                    flags;
    ngx_msec_t                    delay;
    ngx_connection_t             *c, *pc, *src, *dst;
    ngx_log_handler_pt            handler;
    ngx_stream_upstream_t        *u;
    ngx_stream_proxy_srv_conf_t  *pscf;

    u = s->upstream;

    c = s->connection;
    pc = u->connected ? u->peer.connection : NULL;

    pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

    if (from_upstream) {
        src = pc;
        dst = c;
        b = &u->upstream_buf;
        limit_rate = pscf->download_rate;
        received = &u->received;

    } else {
        src = c;
        dst = pc;
        b = &u->downstream_buf;
        limit_rate = pscf->upload_rate;
        received = &s->received;
    }

    for ( ;; ) {

        if (do_write) {

            size = b->last - b->pos;

            if (size && dst && dst->write->ready) {

                n = dst->send(dst, b->pos, size);

                if (n == NGX_ERROR) {
                    ngx_stream_proxy_finalize(s, NGX_DECLINED);
                    return;
                }

                if (n > 0) {
                    b->pos += n;

                    if (b->pos == b->last) {
                        b->pos = b->start;
                        b->last = b->start;
                    }
                }
            }
        }

        size = b->end - b->last;

        if (size && src->read->ready && !src->read->delayed) {

            if (limit_rate) {
                limit = (off_t) limit_rate * (ngx_time() - u->start_sec + 1)
                        - *received;

                if (limit <= 0) {
                    src->read->delayed = 1;
                    delay = (ngx_msec_t) (- limit * 1000 / limit_rate + 1);
                    ngx_add_timer(src->read, delay);
                    break;
                }

                if ((off_t) size > limit) {
                    size = (size_t) limit;
                }
            }

            n = src->recv(src, b->last, size);

            if (n == NGX_AGAIN || n == 0) {
                break;
            }

            if (n > 0) {
                if (limit_rate) {
                    delay = (ngx_msec_t) (n * 1000 / limit_rate);

                    if (delay > 0) {
                        src->read->delayed = 1;
                        ngx_add_timer(src->read, delay);
                    }
                }

                *received += n;
                b->last += n;
                do_write = 1;

                continue;
            }

            if (n == NGX_ERROR) {
                src->read->eof = 1;
            }
        }

        break;
    }

    if (src->read->eof && (b->pos == b->last || (dst && dst->read->eof))) {
        handler = c->log->handler;
        c->log->handler = NULL;

        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "%s disconnected"
                      ", bytes from/to client:%O/%O"
                      ", bytes from/to upstream:%O/%O",
                      from_upstream ? "upstream" : "client",
                      s->received, c->sent, u->received, pc ? pc->sent : 0);

        c->log->handler = handler;

        ngx_stream_proxy_finalize(s, NGX_OK);
        return;
    }

    flags = src->read->eof ? NGX_CLOSE_EVENT : 0;

    if (ngx_handle_read_event(src->read, flags) != NGX_OK) {
        ngx_stream_proxy_finalize(s, NGX_ERROR);
        return;
    }

    if (dst) {
        if (ngx_handle_write_event(dst->write, 0) != NGX_OK) {
            ngx_stream_proxy_finalize(s, NGX_ERROR);
            return;
        }

        if (!c->read->delayed && !pc->read->delayed) {
            ngx_add_timer(c->write, pscf->timeout);

        } else if (c->write->timer_set) {
            ngx_del_timer(c->write);
        }
    }
}


static void
ngx_stream_proxy_next_upstream(ngx_stream_session_t *s)
{
    ngx_msec_t                    timeout;
    ngx_connection_t             *pc;
    ngx_stream_upstream_t        *u;
    ngx_stream_proxy_srv_conf_t  *pscf;

    ngx_log_debug0(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                   "stream proxy next upstream");

    u = s->upstream;

    if (u->peer.sockaddr) {
        u->peer.free(&u->peer, u->peer.data, NGX_PEER_FAILED);
        u->peer.sockaddr = NULL;
    }

    pscf = ngx_stream_get_module_srv_conf(s, ngx_stream_proxy_module);

    timeout = pscf->next_upstream_timeout;

    if (u->peer.tries == 0
        || !pscf->next_upstream
        || (timeout && ngx_current_msec - u->peer.start_time >= timeout))
    {
        ngx_stream_proxy_finalize(s, NGX_DECLINED);
        return;
    }

    pc = u->peer.connection;

    if (pc) {
        ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                       "close proxy upstream connection: %d", pc->fd);

#if (NGX_STREAM_SSL)
        if (pc->ssl) {
            pc->ssl->no_wait_shutdown = 1;
            pc->ssl->no_send_shutdown = 1;

            (void) ngx_ssl_shutdown(pc);
        }
#endif

        ngx_close_connection(pc);
        u->peer.connection = NULL;
    }

    ngx_stream_proxy_connect(s);
}


static void
ngx_stream_proxy_finalize(ngx_stream_session_t *s, ngx_int_t rc)
{
    ngx_connection_t       *pc;
    ngx_stream_upstream_t  *u;

    ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                   "finalize stream proxy: %i", rc);

    u = s->upstream;

    if (u == NULL) {
        goto noupstream;
    }

    if (u->peer.free && u->peer.sockaddr) {
        u->peer.free(&u->peer, u->peer.data, 0);
        u->peer.sockaddr = NULL;
    }

    pc = u->peer.connection;

    if (pc) {
        ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                       "close stream proxy upstream connection: %d", pc->fd);

#if (NGX_STREAM_SSL)
        if (pc->ssl) {
            pc->ssl->no_wait_shutdown = 1;
            (void) ngx_ssl_shutdown(pc);
        }
#endif

        ngx_close_connection(pc);
        u->peer.connection = NULL;
    }

noupstream:

    ngx_stream_close_connection(s->connection);
}


static u_char *
ngx_stream_proxy_log_error(ngx_log_t *log, u_char *buf, size_t len)
{
    u_char                 *p;
    ngx_connection_t       *pc;
    ngx_stream_session_t   *s;
    ngx_stream_upstream_t  *u;

    s = log->data;

    u = s->upstream;

    p = buf;

    if (u->peer.name) {
        p = ngx_snprintf(p, len, ", upstream: \"%V\"", u->peer.name);
        len -= p - buf;
    }

    pc = u->peer.connection;

    p = ngx_snprintf(p, len,
                     ", bytes from/to client:%O/%O"
                     ", bytes from/to upstream:%O/%O",
                     s->received, s->connection->sent,
                     u->received, pc ? pc->sent : 0);

    return p;
}


static void *
ngx_stream_proxy_create_srv_conf(ngx_conf_t *cf)
{
    ngx_stream_proxy_srv_conf_t  *conf;

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

    /*
     * set by ngx_pcalloc():
     *
     *     conf->ssl_protocols = 0;
     *     conf->ssl_ciphers = { 0, NULL };
     *     conf->ssl_name = { 0, NULL };
     *     conf->ssl_trusted_certificate = { 0, NULL };
     *     conf->ssl_crl = { 0, NULL };
     *     conf->ssl_certificate = { 0, NULL };
     *     conf->ssl_certificate_key = { 0, NULL };
     *
     *     conf->ssl = NULL;
     *     conf->upstream = NULL;
     */

    conf->connect_timeout = NGX_CONF_UNSET_MSEC;
    conf->timeout = NGX_CONF_UNSET_MSEC;
    conf->next_upstream_timeout = NGX_CONF_UNSET_MSEC;
    conf->buffer_size = NGX_CONF_UNSET_SIZE;
    conf->upload_rate = NGX_CONF_UNSET_SIZE;
    conf->download_rate = NGX_CONF_UNSET_SIZE;
    conf->next_upstream_tries = NGX_CONF_UNSET_UINT;
    conf->next_upstream = NGX_CONF_UNSET;
    conf->proxy_protocol = NGX_CONF_UNSET;
    conf->local = NGX_CONF_UNSET_PTR;

#if (NGX_STREAM_SSL)
    conf->ssl_enable = NGX_CONF_UNSET;
    conf->ssl_session_reuse = NGX_CONF_UNSET;
    conf->ssl_server_name = NGX_CONF_UNSET;
    conf->ssl_verify = NGX_CONF_UNSET;
    conf->ssl_verify_depth = NGX_CONF_UNSET_UINT;
    conf->ssl_passwords = NGX_CONF_UNSET_PTR;
#endif

    return conf;
}


static char *
ngx_stream_proxy_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_stream_proxy_srv_conf_t *prev = parent;
    ngx_stream_proxy_srv_conf_t *conf = child;

    ngx_conf_merge_msec_value(conf->connect_timeout,
                              prev->connect_timeout, 60000);

    ngx_conf_merge_msec_value(conf->timeout,
                              prev->timeout, 10 * 60000);

    ngx_conf_merge_msec_value(conf->next_upstream_timeout,
                              prev->next_upstream_timeout, 0);

    ngx_conf_merge_size_value(conf->buffer_size,
                              prev->buffer_size, 16384);

    ngx_conf_merge_size_value(conf->upload_rate,
                              prev->upload_rate, 0);

    ngx_conf_merge_size_value(conf->download_rate,
                              prev->download_rate, 0);

    ngx_conf_merge_uint_value(conf->next_upstream_tries,
                              prev->next_upstream_tries, 0);

    ngx_conf_merge_value(conf->next_upstream, prev->next_upstream, 1);

    ngx_conf_merge_value(conf->proxy_protocol, prev->proxy_protocol, 0);

    ngx_conf_merge_ptr_value(conf->local, prev->local, NULL);

#if (NGX_STREAM_SSL)

    ngx_conf_merge_value(conf->ssl_enable, prev->ssl_enable, 0);

    ngx_conf_merge_value(conf->ssl_session_reuse,
                              prev->ssl_session_reuse, 1);

    ngx_conf_merge_bitmask_value(conf->ssl_protocols, prev->ssl_protocols,
                              (NGX_CONF_BITMASK_SET|NGX_SSL_TLSv1
                               |NGX_SSL_TLSv1_1|NGX_SSL_TLSv1_2));

    ngx_conf_merge_str_value(conf->ssl_ciphers, prev->ssl_ciphers, "DEFAULT");

    ngx_conf_merge_str_value(conf->ssl_name, prev->ssl_name, "");

    ngx_conf_merge_value(conf->ssl_server_name, prev->ssl_server_name, 0);

    ngx_conf_merge_value(conf->ssl_verify, prev->ssl_verify, 0);

    ngx_conf_merge_uint_value(conf->ssl_verify_depth,
                              prev->ssl_verify_depth, 1);

    ngx_conf_merge_str_value(conf->ssl_trusted_certificate,
                              prev->ssl_trusted_certificate, "");

    ngx_conf_merge_str_value(conf->ssl_crl, prev->ssl_crl, "");

    ngx_conf_merge_str_value(conf->ssl_certificate,
                              prev->ssl_certificate, "");

    ngx_conf_merge_str_value(conf->ssl_certificate_key,
                              prev->ssl_certificate_key, "");

    ngx_conf_merge_ptr_value(conf->ssl_passwords, prev->ssl_passwords, NULL);

    if (conf->ssl_enable && ngx_stream_proxy_set_ssl(cf, conf) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

#endif

    return NGX_CONF_OK;
}


#if (NGX_STREAM_SSL)

static ngx_int_t
ngx_stream_proxy_set_ssl(ngx_conf_t *cf, ngx_stream_proxy_srv_conf_t *pscf)
{
    ngx_pool_cleanup_t  *cln;

    pscf->ssl = ngx_pcalloc(cf->pool, sizeof(ngx_ssl_t));
    if (pscf->ssl == NULL) {
        return NGX_ERROR;
    }

    pscf->ssl->log = cf->log;

    if (ngx_ssl_create(pscf->ssl, pscf->ssl_protocols, NULL) != NGX_OK) {
        return NGX_ERROR;
    }

    cln = ngx_pool_cleanup_add(cf->pool, 0);
    if (cln == NULL) {
        return NGX_ERROR;
    }

    cln->handler = ngx_ssl_cleanup_ctx;
    cln->data = pscf->ssl;

    if (pscf->ssl_certificate.len) {

        if (pscf->ssl_certificate_key.len == 0) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                          "no \"proxy_ssl_certificate_key\" is defined "
                          "for certificate \"%V\"", &pscf->ssl_certificate);
            return NGX_ERROR;
        }

        if (ngx_ssl_certificate(cf, pscf->ssl, &pscf->ssl_certificate,
                                &pscf->ssl_certificate_key, pscf->ssl_passwords)
            != NGX_OK)
        {
            return NGX_ERROR;
        }
    }

    if (SSL_CTX_set_cipher_list(pscf->ssl->ctx,
                                (const char *) pscf->ssl_ciphers.data)
        == 0)
    {
        ngx_ssl_error(NGX_LOG_EMERG, cf->log, 0,
                      "SSL_CTX_set_cipher_list(\"%V\") failed",
                      &pscf->ssl_ciphers);
        return NGX_ERROR;
    }

    if (pscf->ssl_verify) {
        if (pscf->ssl_trusted_certificate.len == 0) {
            ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
                      "no proxy_ssl_trusted_certificate for proxy_ssl_verify");
            return NGX_ERROR;
        }

        if (ngx_ssl_trusted_certificate(cf, pscf->ssl,
                                        &pscf->ssl_trusted_certificate,
                                        pscf->ssl_verify_depth)
            != NGX_OK)
        {
            return NGX_ERROR;
        }

        if (ngx_ssl_crl(cf, pscf->ssl, &pscf->ssl_crl) != NGX_OK) {
            return NGX_ERROR;
        }
    }

    return NGX_OK;
}

#endif


static char *
ngx_stream_proxy_pass(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_proxy_srv_conf_t *pscf = conf;

    ngx_url_t                    u;
    ngx_str_t                   *value, *url;
    ngx_stream_core_srv_conf_t  *cscf;

    if (pscf->upstream) {
        return "is duplicate";
    }

    cscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_core_module);

    cscf->handler = ngx_stream_proxy_handler;

    value = cf->args->elts;

    url = &value[1];

    ngx_memzero(&u, sizeof(ngx_url_t));

    u.url = *url;
    u.no_resolve = 1;

    pscf->upstream = ngx_stream_upstream_add(cf, &u, 0);
    if (pscf->upstream == NULL) {
        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static char *
ngx_stream_proxy_bind(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_proxy_srv_conf_t *pscf = conf;

    ngx_int_t   rc;
    ngx_str_t  *value;

    if (pscf->local != NGX_CONF_UNSET_PTR) {
        return "is duplicate";
    }

    value = cf->args->elts;

    if (ngx_strcmp(value[1].data, "off") == 0) {
        pscf->local = NULL;
        return NGX_CONF_OK;
    }

    pscf->local = ngx_palloc(cf->pool, sizeof(ngx_addr_t));
    if (pscf->local == NULL) {
        return NGX_CONF_ERROR;
    }

    rc = ngx_parse_addr(cf->pool, pscf->local, value[1].data, value[1].len);

    switch (rc) {
    case NGX_OK:
        pscf->local->name = value[1];
        return NGX_CONF_OK;

    case NGX_DECLINED:
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid address \"%V\"", &value[1]);
        /* fall through */

    default:
        return NGX_CONF_ERROR;
    }
}