view src/http/ngx_http_request.c @ 5089:903f2a5d86a5

SNI: reuse selected configuration for all requests in a connection. Previously, only the first request in a connection was assigned the configuration selected by SNI. All subsequent requests initially used the default server's configuration, ignoring SNI, which was wrong. Now all subsequent requests in a connection will initially use the configuration selected by SNI. This is done by storing a pointer to configuration in http connection object. It points to default server's configuration initially, but changed upon receipt of SNI. (The request's configuration can be further refined when parsing the request line and Host: header.) This change was not made specific to SNI as it also allows slightly faster access to configuration without the request object.
author Valentin Bartenev <vbart@nginx.com>
date Wed, 27 Feb 2013 17:12:48 +0000
parents ac31fcecb464
children 9db95b275755
line wrap: on
line source


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


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


static void ngx_http_init_request(ngx_event_t *ev);
static void ngx_http_process_request_line(ngx_event_t *rev);
static void ngx_http_process_request_headers(ngx_event_t *rev);
static ssize_t ngx_http_read_request_header(ngx_http_request_t *r);
static ngx_int_t ngx_http_alloc_large_header_buffer(ngx_http_request_t *r,
    ngx_uint_t request_line);

static ngx_int_t ngx_http_process_header_line(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_unique_header_line(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_multi_header_lines(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_host(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_connection(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_user_agent(ngx_http_request_t *r,
    ngx_table_elt_t *h, ngx_uint_t offset);

static ngx_int_t ngx_http_process_request_header(ngx_http_request_t *r);
static void ngx_http_process_request(ngx_http_request_t *r);
static ngx_int_t ngx_http_validate_host(ngx_str_t *host, ngx_pool_t *pool,
    ngx_uint_t alloc);
static ngx_int_t ngx_http_set_virtual_server(ngx_http_request_t *r,
    ngx_str_t *host);
static ngx_int_t ngx_http_find_virtual_server(ngx_connection_t *c,
    ngx_http_virtual_names_t *virtual_names, ngx_str_t *host,
    ngx_http_request_t *r, ngx_http_core_srv_conf_t **cscfp);

static void ngx_http_request_handler(ngx_event_t *ev);
static void ngx_http_terminate_request(ngx_http_request_t *r, ngx_int_t rc);
static void ngx_http_terminate_handler(ngx_http_request_t *r);
static void ngx_http_finalize_connection(ngx_http_request_t *r);
static ngx_int_t ngx_http_set_write_handler(ngx_http_request_t *r);
static void ngx_http_writer(ngx_http_request_t *r);
static void ngx_http_request_finalizer(ngx_http_request_t *r);

static void ngx_http_set_keepalive(ngx_http_request_t *r);
static void ngx_http_keepalive_handler(ngx_event_t *ev);
static void ngx_http_set_lingering_close(ngx_http_request_t *r);
static void ngx_http_lingering_close_handler(ngx_event_t *ev);
static ngx_int_t ngx_http_post_action(ngx_http_request_t *r);
static void ngx_http_close_request(ngx_http_request_t *r, ngx_int_t error);
static void ngx_http_free_request(ngx_http_request_t *r, ngx_int_t error);
static void ngx_http_log_request(ngx_http_request_t *r);
static void ngx_http_close_connection(ngx_connection_t *c);

static u_char *ngx_http_log_error(ngx_log_t *log, u_char *buf, size_t len);
static u_char *ngx_http_log_error_handler(ngx_http_request_t *r,
    ngx_http_request_t *sr, u_char *buf, size_t len);

#if (NGX_HTTP_SSL)
static void ngx_http_ssl_handshake(ngx_event_t *rev);
static void ngx_http_ssl_handshake_handler(ngx_connection_t *c);
#endif


static char *ngx_http_client_errors[] = {

    /* NGX_HTTP_PARSE_INVALID_METHOD */
    "client sent invalid method",

    /* NGX_HTTP_PARSE_INVALID_REQUEST */
    "client sent invalid request",

    /* NGX_HTTP_PARSE_INVALID_09_METHOD */
    "client sent invalid method in HTTP/0.9 request"
};


ngx_http_header_t  ngx_http_headers_in[] = {
    { ngx_string("Host"), offsetof(ngx_http_headers_in_t, host),
                 ngx_http_process_host },

    { ngx_string("Connection"), offsetof(ngx_http_headers_in_t, connection),
                 ngx_http_process_connection },

    { ngx_string("If-Modified-Since"),
                 offsetof(ngx_http_headers_in_t, if_modified_since),
                 ngx_http_process_unique_header_line },

    { ngx_string("If-Unmodified-Since"),
                 offsetof(ngx_http_headers_in_t, if_unmodified_since),
                 ngx_http_process_unique_header_line },

    { ngx_string("If-Match"),
                 offsetof(ngx_http_headers_in_t, if_match),
                 ngx_http_process_unique_header_line },

    { ngx_string("If-None-Match"),
                 offsetof(ngx_http_headers_in_t, if_none_match),
                 ngx_http_process_unique_header_line },

    { ngx_string("User-Agent"), offsetof(ngx_http_headers_in_t, user_agent),
                 ngx_http_process_user_agent },

    { ngx_string("Referer"), offsetof(ngx_http_headers_in_t, referer),
                 ngx_http_process_header_line },

    { ngx_string("Content-Length"),
                 offsetof(ngx_http_headers_in_t, content_length),
                 ngx_http_process_unique_header_line },

    { ngx_string("Content-Type"),
                 offsetof(ngx_http_headers_in_t, content_type),
                 ngx_http_process_header_line },

    { ngx_string("Range"), offsetof(ngx_http_headers_in_t, range),
                 ngx_http_process_header_line },

    { ngx_string("If-Range"),
                 offsetof(ngx_http_headers_in_t, if_range),
                 ngx_http_process_unique_header_line },

    { ngx_string("Transfer-Encoding"),
                 offsetof(ngx_http_headers_in_t, transfer_encoding),
                 ngx_http_process_header_line },

    { ngx_string("Expect"),
                 offsetof(ngx_http_headers_in_t, expect),
                 ngx_http_process_unique_header_line },

    { ngx_string("Upgrade"),
                 offsetof(ngx_http_headers_in_t, upgrade),
                 ngx_http_process_header_line },

#if (NGX_HTTP_GZIP)
    { ngx_string("Accept-Encoding"),
                 offsetof(ngx_http_headers_in_t, accept_encoding),
                 ngx_http_process_header_line },

    { ngx_string("Via"), offsetof(ngx_http_headers_in_t, via),
                 ngx_http_process_header_line },
#endif

    { ngx_string("Authorization"),
                 offsetof(ngx_http_headers_in_t, authorization),
                 ngx_http_process_unique_header_line },

    { ngx_string("Keep-Alive"), offsetof(ngx_http_headers_in_t, keep_alive),
                 ngx_http_process_header_line },

#if (NGX_HTTP_X_FORWARDED_FOR)
    { ngx_string("X-Forwarded-For"),
                 offsetof(ngx_http_headers_in_t, x_forwarded_for),
                 ngx_http_process_multi_header_lines },
#endif

#if (NGX_HTTP_REALIP)
    { ngx_string("X-Real-IP"),
                 offsetof(ngx_http_headers_in_t, x_real_ip),
                 ngx_http_process_header_line },
#endif

#if (NGX_HTTP_HEADERS)
    { ngx_string("Accept"), offsetof(ngx_http_headers_in_t, accept),
                 ngx_http_process_header_line },

    { ngx_string("Accept-Language"),
                 offsetof(ngx_http_headers_in_t, accept_language),
                 ngx_http_process_header_line },
#endif

#if (NGX_HTTP_DAV)
    { ngx_string("Depth"), offsetof(ngx_http_headers_in_t, depth),
                 ngx_http_process_header_line },

    { ngx_string("Destination"), offsetof(ngx_http_headers_in_t, destination),
                 ngx_http_process_header_line },

    { ngx_string("Overwrite"), offsetof(ngx_http_headers_in_t, overwrite),
                 ngx_http_process_header_line },

    { ngx_string("Date"), offsetof(ngx_http_headers_in_t, date),
                 ngx_http_process_header_line },
#endif

    { ngx_string("Cookie"), offsetof(ngx_http_headers_in_t, cookies),
                 ngx_http_process_multi_header_lines },

    { ngx_null_string, 0, NULL }
};


void
ngx_http_init_connection(ngx_connection_t *c)
{
    ngx_uint_t              i;
    ngx_event_t            *rev;
    struct sockaddr_in     *sin;
    ngx_http_port_t        *port;
    ngx_http_in_addr_t     *addr;
    ngx_http_log_ctx_t     *ctx;
    ngx_http_connection_t  *hc;
#if (NGX_HAVE_INET6)
    struct sockaddr_in6    *sin6;
    ngx_http_in6_addr_t    *addr6;
#endif

    hc = ngx_pcalloc(c->pool, sizeof(ngx_http_connection_t));
    if (hc == NULL) {
        ngx_http_close_connection(c);
        return;
    }

    c->data = hc;

    /* find the server configuration for the address:port */

    port = c->listening->servers;

    if (port->naddrs > 1) {

        /*
         * there are several addresses on this port and one of them
         * is an "*:port" wildcard so getsockname() in ngx_http_server_addr()
         * is required to determine a server address
         */

        if (ngx_connection_local_sockaddr(c, NULL, 0) != NGX_OK) {
            ngx_http_close_connection(c);
            return;
        }

        switch (c->local_sockaddr->sa_family) {

#if (NGX_HAVE_INET6)
        case AF_INET6:
            sin6 = (struct sockaddr_in6 *) c->local_sockaddr;

            addr6 = port->addrs;

            /* the last address is "*" */

            for (i = 0; i < port->naddrs - 1; i++) {
                if (ngx_memcmp(&addr6[i].addr6, &sin6->sin6_addr, 16) == 0) {
                    break;
                }
            }

            hc->addr_conf = &addr6[i].conf;

            break;
#endif

        default: /* AF_INET */
            sin = (struct sockaddr_in *) c->local_sockaddr;

            addr = port->addrs;

            /* the last address is "*" */

            for (i = 0; i < port->naddrs - 1; i++) {
                if (addr[i].addr == sin->sin_addr.s_addr) {
                    break;
                }
            }

            hc->addr_conf = &addr[i].conf;

            break;
        }

    } else {

        switch (c->local_sockaddr->sa_family) {

#if (NGX_HAVE_INET6)
        case AF_INET6:
            addr6 = port->addrs;
            hc->addr_conf = &addr6[0].conf;
            break;
#endif

        default: /* AF_INET */
            addr = port->addrs;
            hc->addr_conf = &addr[0].conf;
            break;
        }
    }

    /* the default server configuration for the address:port */
    hc->conf_ctx = hc->addr_conf->default_server->ctx;

    ctx = ngx_palloc(c->pool, sizeof(ngx_http_log_ctx_t));
    if (ctx == NULL) {
        ngx_http_close_connection(c);
        return;
    }

    ctx->connection = c;
    ctx->request = NULL;
    ctx->current_request = NULL;

    c->log->connection = c->number;
    c->log->handler = ngx_http_log_error;
    c->log->data = ctx;
    c->log->action = "reading client request line";

    c->log_error = NGX_ERROR_INFO;

    rev = c->read;
    rev->handler = ngx_http_init_request;
    c->write->handler = ngx_http_empty_handler;

#if (NGX_STAT_STUB)
    (void) ngx_atomic_fetch_add(ngx_stat_reading, 1);
#endif

    if (rev->ready) {
        /* the deferred accept(), rtsig, aio, iocp */

        if (ngx_use_accept_mutex) {
            ngx_post_event(rev, &ngx_posted_events);
            return;
        }

        ngx_http_init_request(rev);
        return;
    }

    ngx_add_timer(rev, c->listening->post_accept_timeout);

    if (ngx_handle_read_event(rev, 0) != NGX_OK) {
#if (NGX_STAT_STUB)
        (void) ngx_atomic_fetch_add(ngx_stat_reading, -1);
#endif
        ngx_http_close_connection(c);
        return;
    }
}


static void
ngx_http_init_request(ngx_event_t *rev)
{
    ngx_time_t                 *tp;
    ngx_connection_t           *c;
    ngx_http_request_t         *r;
    ngx_http_log_ctx_t         *ctx;
    ngx_http_connection_t      *hc;
    ngx_http_core_srv_conf_t   *cscf;
    ngx_http_core_loc_conf_t   *clcf;
    ngx_http_core_main_conf_t  *cmcf;

#if (NGX_STAT_STUB)
    (void) ngx_atomic_fetch_add(ngx_stat_reading, -1);
#endif

    c = rev->data;

    if (rev->timedout) {
        ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");

        ngx_http_close_connection(c);
        return;
    }

    c->requests++;

    hc = c->data;

    r = hc->request;

    if (r) {
        ngx_memzero(r, sizeof(ngx_http_request_t));

        r->pipeline = hc->pipeline;

        if (hc->nbusy) {
            r->header_in = hc->busy[0];
        }

    } else {
        r = ngx_pcalloc(c->pool, sizeof(ngx_http_request_t));
        if (r == NULL) {
            ngx_http_close_connection(c);
            return;
        }

        hc->request = r;
    }

    c->data = r;
    r->http_connection = hc;

    c->sent = 0;
    r->signature = NGX_HTTP_MODULE;

    r->connection = c;

    r->main_conf = hc->conf_ctx->main_conf;
    r->srv_conf = hc->conf_ctx->srv_conf;
    r->loc_conf = hc->conf_ctx->loc_conf;

    rev->handler = ngx_http_process_request_line;
    r->read_event_handler = ngx_http_block_reading;

#if (NGX_HTTP_SSL)

    {
    ngx_http_ssl_srv_conf_t  *sscf;

    sscf = ngx_http_get_module_srv_conf(r, ngx_http_ssl_module);
    if (sscf->enable || hc->addr_conf->ssl) {

        if (c->ssl == NULL) {

            c->log->action = "SSL handshaking";

            if (hc->addr_conf->ssl && sscf->ssl.ctx == NULL) {
                ngx_log_error(NGX_LOG_ERR, c->log, 0,
                              "no \"ssl_certificate\" is defined "
                              "in server listening on SSL port");
                ngx_http_close_connection(c);
                return;
            }

            if (ngx_ssl_create_connection(&sscf->ssl, c, NGX_SSL_BUFFER)
                != NGX_OK)
            {
                ngx_http_close_connection(c);
                return;
            }

            rev->handler = ngx_http_ssl_handshake;
        }

        r->main_filter_need_in_memory = 1;
    }
    }

#endif

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    ngx_http_set_connection_log(r->connection, clcf->error_log);

    cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

    if (c->buffer == NULL) {
        c->buffer = ngx_create_temp_buf(c->pool,
                                        cscf->client_header_buffer_size);
        if (c->buffer == NULL) {
            ngx_http_close_connection(c);
            return;
        }
    }

    if (r->header_in == NULL) {
        r->header_in = c->buffer;
    }

    r->pool = ngx_create_pool(cscf->request_pool_size, c->log);
    if (r->pool == NULL) {
        ngx_http_close_connection(c);
        return;
    }


    if (ngx_list_init(&r->headers_out.headers, r->pool, 20,
                      sizeof(ngx_table_elt_t))
        != NGX_OK)
    {
        ngx_destroy_pool(r->pool);
        ngx_http_close_connection(c);
        return;
    }

    r->ctx = ngx_pcalloc(r->pool, sizeof(void *) * ngx_http_max_module);
    if (r->ctx == NULL) {
        ngx_destroy_pool(r->pool);
        ngx_http_close_connection(c);
        return;
    }

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    r->variables = ngx_pcalloc(r->pool, cmcf->variables.nelts
                                        * sizeof(ngx_http_variable_value_t));
    if (r->variables == NULL) {
        ngx_destroy_pool(r->pool);
        ngx_http_close_connection(c);
        return;
    }

    c->single_connection = 1;
    c->destroyed = 0;

    r->main = r;
    r->count = 1;

    tp = ngx_timeofday();
    r->start_sec = tp->sec;
    r->start_msec = tp->msec;

    r->method = NGX_HTTP_UNKNOWN;

    r->headers_in.content_length_n = -1;
    r->headers_in.keep_alive_n = -1;
    r->headers_out.content_length_n = -1;
    r->headers_out.last_modified_time = -1;

    r->uri_changes = NGX_HTTP_MAX_URI_CHANGES + 1;
    r->subrequests = NGX_HTTP_MAX_SUBREQUESTS + 1;

    r->http_state = NGX_HTTP_READING_REQUEST_STATE;

    ctx = c->log->data;
    ctx->request = r;
    ctx->current_request = r;
    r->log_handler = ngx_http_log_error_handler;

#if (NGX_STAT_STUB)
    (void) ngx_atomic_fetch_add(ngx_stat_reading, 1);
    r->stat_reading = 1;
    (void) ngx_atomic_fetch_add(ngx_stat_requests, 1);
#endif

    rev->handler(rev);
}


#if (NGX_HTTP_SSL)

static void
ngx_http_ssl_handshake(ngx_event_t *rev)
{
    u_char               buf[1];
    ssize_t              n;
    ngx_int_t            rc;
    ngx_connection_t    *c;
    ngx_http_request_t  *r;

    c = rev->data;
    r = c->data;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                   "http check ssl handshake");

    if (rev->timedout) {
        ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
        c->timedout = 1;
        ngx_http_close_request(r, NGX_HTTP_REQUEST_TIME_OUT);
        return;
    }

    n = recv(c->fd, (char *) buf, 1, MSG_PEEK);

    if (n == -1 && ngx_socket_errno == NGX_EAGAIN) {

        if (!rev->timer_set) {
            ngx_add_timer(rev, c->listening->post_accept_timeout);
        }

        if (ngx_handle_read_event(rev, 0) != NGX_OK) {
            ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        }

        return;
    }

    if (n == 1) {
        if (buf[0] & 0x80 /* SSLv2 */ || buf[0] == 0x16 /* SSLv3/TLSv1 */) {
            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                           "https ssl handshake: 0x%02Xd", buf[0]);

            rc = ngx_ssl_handshake(c);

            if (rc == NGX_AGAIN) {

                if (!rev->timer_set) {
                    ngx_add_timer(rev, c->listening->post_accept_timeout);
                }

                c->ssl->handler = ngx_http_ssl_handshake_handler;
                return;
            }

            ngx_http_ssl_handshake_handler(c);

            return;

        } else {
            ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                           "plain http");

            r->plain_http = 1;
        }
    }

    c->log->action = "reading client request line";

    rev->handler = ngx_http_process_request_line;
    ngx_http_process_request_line(rev);
}


static void
ngx_http_ssl_handshake_handler(ngx_connection_t *c)
{
    ngx_http_request_t  *r;

    if (c->ssl->handshaked) {

        /*
         * The majority of browsers do not send the "close notify" alert.
         * Among them are MSIE, old Mozilla, Netscape 4, Konqueror,
         * and Links.  And what is more, MSIE ignores the server's alert.
         *
         * Opera and recent Mozilla send the alert.
         */

        c->ssl->no_wait_shutdown = 1;

        c->log->action = "reading client request line";

        c->read->handler = ngx_http_process_request_line;
        /* STUB: epoll edge */ c->write->handler = ngx_http_empty_handler;

        ngx_http_process_request_line(c->read);

        return;
    }

    r = c->data;

    ngx_http_close_request(r, NGX_HTTP_BAD_REQUEST);

    return;
}

#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME

int
ngx_http_ssl_servername(ngx_ssl_conn_t *ssl_conn, int *ad, void *arg)
{
    ngx_str_t                  host;
    const char                *servername;
    ngx_connection_t          *c;
    ngx_http_request_t        *r;
    ngx_http_connection_t     *hc;
    ngx_http_ssl_srv_conf_t   *sscf;
    ngx_http_core_loc_conf_t  *clcf;
    ngx_http_core_srv_conf_t  *cscf;

    servername = SSL_get_servername(ssl_conn, TLSEXT_NAMETYPE_host_name);

    if (servername == NULL) {
        return SSL_TLSEXT_ERR_NOACK;
    }

    c = ngx_ssl_get_connection(ssl_conn);

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "SSL server name: \"%s\"", servername);

    host.len = ngx_strlen(servername);

    if (host.len == 0) {
        return SSL_TLSEXT_ERR_NOACK;
    }

    r = c->data;

    host.data = (u_char *) servername;

    if (ngx_http_validate_host(&host, r->pool, 1) != NGX_OK) {
        return SSL_TLSEXT_ERR_NOACK;
    }

    hc = r->http_connection;

    if (ngx_http_find_virtual_server(c, hc->addr_conf->virtual_names, &host,
                                     NULL, &cscf)
        != NGX_OK)
    {
        return SSL_TLSEXT_ERR_NOACK;
    }

    hc->conf_ctx = cscf->ctx;

    r->srv_conf = cscf->ctx->srv_conf;
    r->loc_conf = cscf->ctx->loc_conf;

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    ngx_http_set_connection_log(c, clcf->error_log);

    sscf = ngx_http_get_module_srv_conf(r, ngx_http_ssl_module);

    if (sscf->ssl.ctx) {
        SSL_set_SSL_CTX(ssl_conn, sscf->ssl.ctx);

        /*
         * SSL_set_SSL_CTX() only changes certs as of 1.0.0d
         * adjust other things we care about
         */

        SSL_set_verify(ssl_conn, SSL_CTX_get_verify_mode(sscf->ssl.ctx),
                       SSL_CTX_get_verify_callback(sscf->ssl.ctx));

        SSL_set_verify_depth(ssl_conn, SSL_CTX_get_verify_depth(sscf->ssl.ctx));

#ifdef SSL_CTRL_CLEAR_OPTIONS
        /* only in 0.9.8m+ */
        SSL_clear_options(ssl_conn, SSL_get_options(ssl_conn) &
                                    ~SSL_CTX_get_options(sscf->ssl.ctx));
#endif

        SSL_set_options(ssl_conn, SSL_CTX_get_options(sscf->ssl.ctx));
    }

    return SSL_TLSEXT_ERR_OK;
}

#endif

#endif


static void
ngx_http_process_request_line(ngx_event_t *rev)
{
    ssize_t                    n;
    ngx_int_t                  rc, rv;
    ngx_str_t                  host;
    ngx_connection_t          *c;
    ngx_http_request_t        *r;
    ngx_http_core_srv_conf_t  *cscf;

    c = rev->data;
    r = c->data;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                   "http process request line");

    if (rev->timedout) {
        ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
        c->timedout = 1;
        ngx_http_close_request(r, NGX_HTTP_REQUEST_TIME_OUT);
        return;
    }

    rc = NGX_AGAIN;

    for ( ;; ) {

        if (rc == NGX_AGAIN) {
            n = ngx_http_read_request_header(r);

            if (n == NGX_AGAIN || n == NGX_ERROR) {
                return;
            }
        }

        rc = ngx_http_parse_request_line(r, r->header_in);

        if (rc == NGX_OK) {

            /* the request line has been parsed successfully */

            r->request_line.len = r->request_end - r->request_start;
            r->request_line.data = r->request_start;
            r->request_length = r->header_in->pos - r->request_start;


            if (r->args_start) {
                r->uri.len = r->args_start - 1 - r->uri_start;
            } else {
                r->uri.len = r->uri_end - r->uri_start;
            }


            if (r->complex_uri || r->quoted_uri) {

                r->uri.data = ngx_pnalloc(r->pool, r->uri.len + 1);
                if (r->uri.data == NULL) {
                    ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                    return;
                }

                cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

                rc = ngx_http_parse_complex_uri(r, cscf->merge_slashes);

                if (rc == NGX_HTTP_PARSE_INVALID_REQUEST) {
                    ngx_log_error(NGX_LOG_INFO, c->log, 0,
                                  "client sent invalid request");
                    ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
                    return;
                }

            } else {
                r->uri.data = r->uri_start;
            }


            r->unparsed_uri.len = r->uri_end - r->uri_start;
            r->unparsed_uri.data = r->uri_start;

            r->valid_unparsed_uri = r->space_in_uri ? 0 : 1;

            r->method_name.len = r->method_end - r->request_start + 1;
            r->method_name.data = r->request_line.data;


            if (r->http_protocol.data) {
                r->http_protocol.len = r->request_end - r->http_protocol.data;
            }


            if (r->uri_ext) {
                if (r->args_start) {
                    r->exten.len = r->args_start - 1 - r->uri_ext;
                } else {
                    r->exten.len = r->uri_end - r->uri_ext;
                }

                r->exten.data = r->uri_ext;
            }


            if (r->args_start && r->uri_end > r->args_start) {
                r->args.len = r->uri_end - r->args_start;
                r->args.data = r->args_start;
            }

#if (NGX_WIN32)
            {
            u_char  *p, *last;

            p = r->uri.data;
            last = r->uri.data + r->uri.len;

            while (p < last) {

                if (*p++ == ':') {

                    /*
                     * this check covers "::$data", "::$index_allocation" and
                     * ":$i30:$index_allocation"
                     */

                    if (p < last && *p == '$') {
                        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                                      "client sent unsafe win32 URI");
                        ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
                        return;
                    }
                }
            }

            p = r->uri.data + r->uri.len - 1;

            while (p > r->uri.data) {

                if (*p == ' ') {
                    p--;
                    continue;
                }

                if (*p == '.') {
                    p--;
                    continue;
                }

                break;
            }

            if (p != r->uri.data + r->uri.len - 1) {
                r->uri.len = p + 1 - r->uri.data;
                ngx_http_set_exten(r);
            }

            }
#endif

            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                           "http request line: \"%V\"", &r->request_line);

            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                           "http uri: \"%V\"", &r->uri);

            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                           "http args: \"%V\"", &r->args);

            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                           "http exten: \"%V\"", &r->exten);

            if (r->host_start && r->host_end) {

                host.len = r->host_end - r->host_start;
                host.data = r->host_start;

                rc = ngx_http_validate_host(&host, r->pool, 0);

                if (rc == NGX_DECLINED) {
                    ngx_log_error(NGX_LOG_INFO, c->log, 0,
                                  "client sent invalid host in request line");
                    ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
                    return;
                }

                if (rc == NGX_ERROR) {
                    ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                    return;
                }

                r->headers_in.server = host;
            }

            if (r->http_version < NGX_HTTP_VERSION_10) {

                if (ngx_http_set_virtual_server(r, &r->headers_in.server)
                    == NGX_ERROR)
                {
                    return;
                }

                ngx_http_process_request(r);
                return;
            }


            if (ngx_list_init(&r->headers_in.headers, r->pool, 20,
                              sizeof(ngx_table_elt_t))
                != NGX_OK)
            {
                ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                return;
            }

            c->log->action = "reading client request headers";

            rev->handler = ngx_http_process_request_headers;
            ngx_http_process_request_headers(rev);

            return;
        }

        if (rc != NGX_AGAIN) {

            /* there was error while a request line parsing */

            ngx_log_error(NGX_LOG_INFO, c->log, 0,
                          ngx_http_client_errors[rc - NGX_HTTP_CLIENT_ERROR]);
            ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
            return;
        }

        /* NGX_AGAIN: a request line parsing is still incomplete */

        if (r->header_in->pos == r->header_in->end) {

            rv = ngx_http_alloc_large_header_buffer(r, 1);

            if (rv == NGX_ERROR) {
                ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                return;
            }

            if (rv == NGX_DECLINED) {
                r->request_line.len = r->header_in->end - r->request_start;
                r->request_line.data = r->request_start;

                ngx_log_error(NGX_LOG_INFO, c->log, 0,
                              "client sent too long URI");
                ngx_http_finalize_request(r, NGX_HTTP_REQUEST_URI_TOO_LARGE);
                return;
            }
        }
    }
}


static void
ngx_http_process_request_headers(ngx_event_t *rev)
{
    u_char                     *p;
    size_t                      len;
    ssize_t                     n;
    ngx_int_t                   rc, rv;
    ngx_table_elt_t            *h;
    ngx_connection_t           *c;
    ngx_http_header_t          *hh;
    ngx_http_request_t         *r;
    ngx_http_core_srv_conf_t   *cscf;
    ngx_http_core_main_conf_t  *cmcf;

    c = rev->data;
    r = c->data;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                   "http process request header line");

    if (rev->timedout) {
        ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
        c->timedout = 1;
        ngx_http_close_request(r, NGX_HTTP_REQUEST_TIME_OUT);
        return;
    }

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);
    cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

    rc = NGX_AGAIN;

    for ( ;; ) {

        if (rc == NGX_AGAIN) {

            if (r->header_in->pos == r->header_in->end) {

                rv = ngx_http_alloc_large_header_buffer(r, 0);

                if (rv == NGX_ERROR) {
                    ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                    return;
                }

                if (rv == NGX_DECLINED) {
                    p = r->header_name_start;

                    r->lingering_close = 1;

                    if (p == NULL) {
                        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                                      "client sent too large request");
                        ngx_http_finalize_request(r,
                                            NGX_HTTP_REQUEST_HEADER_TOO_LARGE);
                        return;
                    }

                    len = r->header_in->end - p;

                    if (len > NGX_MAX_ERROR_STR - 300) {
                        len = NGX_MAX_ERROR_STR - 300;
                        p[len++] = '.'; p[len++] = '.'; p[len++] = '.';
                    }

                    ngx_log_error(NGX_LOG_INFO, c->log, 0,
                                  "client sent too long header line: \"%*s\"",
                                  len, r->header_name_start);

                    ngx_http_finalize_request(r,
                                            NGX_HTTP_REQUEST_HEADER_TOO_LARGE);
                    return;
                }
            }

            n = ngx_http_read_request_header(r);

            if (n == NGX_AGAIN || n == NGX_ERROR) {
                return;
            }
        }

        rc = ngx_http_parse_header_line(r, r->header_in,
                                        cscf->underscores_in_headers);

        if (rc == NGX_OK) {

            r->request_length += r->header_in->pos - r->header_name_start;

            if (r->invalid_header && cscf->ignore_invalid_headers) {

                /* there was error while a header line parsing */

                ngx_log_error(NGX_LOG_INFO, c->log, 0,
                              "client sent invalid header line: \"%*s\"",
                              r->header_end - r->header_name_start,
                              r->header_name_start);
                continue;
            }

            /* a header line has been parsed successfully */

            h = ngx_list_push(&r->headers_in.headers);
            if (h == NULL) {
                ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                return;
            }

            h->hash = r->header_hash;

            h->key.len = r->header_name_end - r->header_name_start;
            h->key.data = r->header_name_start;
            h->key.data[h->key.len] = '\0';

            h->value.len = r->header_end - r->header_start;
            h->value.data = r->header_start;
            h->value.data[h->value.len] = '\0';

            h->lowcase_key = ngx_pnalloc(r->pool, h->key.len);
            if (h->lowcase_key == NULL) {
                ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
                return;
            }

            if (h->key.len == r->lowcase_index) {
                ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);

            } else {
                ngx_strlow(h->lowcase_key, h->key.data, h->key.len);
            }

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

            if (hh && hh->handler(r, h, hh->offset) != NGX_OK) {
                return;
            }

            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "http header: \"%V: %V\"",
                           &h->key, &h->value);

            continue;
        }

        if (rc == NGX_HTTP_PARSE_HEADER_DONE) {

            /* a whole header has been parsed successfully */

            ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                           "http header done");

            r->request_length += r->header_in->pos - r->header_name_start;

            r->http_state = NGX_HTTP_PROCESS_REQUEST_STATE;

            rc = ngx_http_process_request_header(r);

            if (rc != NGX_OK) {
                return;
            }

            ngx_http_process_request(r);

            return;
        }

        if (rc == NGX_AGAIN) {

            /* a header line parsing is still not complete */

            continue;
        }

        /* rc == NGX_HTTP_PARSE_INVALID_HEADER: "\r" is not followed by "\n" */

        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "client sent invalid header line: \"%*s\\r...\"",
                      r->header_end - r->header_name_start,
                      r->header_name_start);
        ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
        return;
    }
}


static ssize_t
ngx_http_read_request_header(ngx_http_request_t *r)
{
    ssize_t                    n;
    ngx_event_t               *rev;
    ngx_connection_t          *c;
    ngx_http_core_srv_conf_t  *cscf;

    c = r->connection;
    rev = c->read;

    n = r->header_in->last - r->header_in->pos;

    if (n > 0) {
        return n;
    }

    if (rev->ready) {
        n = c->recv(c, r->header_in->last,
                    r->header_in->end - r->header_in->last);
    } else {
        n = NGX_AGAIN;
    }

    if (n == NGX_AGAIN) {
        if (!rev->timer_set) {
            cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);
            ngx_add_timer(rev, cscf->client_header_timeout);
        }

        if (ngx_handle_read_event(rev, 0) != NGX_OK) {
            ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
            return NGX_ERROR;
        }

        return NGX_AGAIN;
    }

    if (n == 0) {
        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "client prematurely closed connection");
    }

    if (n == 0 || n == NGX_ERROR) {
        c->error = 1;
        c->log->action = "reading client request headers";

        ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
        return NGX_ERROR;
    }

    r->header_in->last += n;

    return n;
}


static ngx_int_t
ngx_http_alloc_large_header_buffer(ngx_http_request_t *r,
    ngx_uint_t request_line)
{
    u_char                    *old, *new;
    ngx_buf_t                 *b;
    ngx_http_connection_t     *hc;
    ngx_http_core_srv_conf_t  *cscf;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http alloc large header buffer");

    if (request_line && r->state == 0) {

        /* the client fills up the buffer with "\r\n" */

        r->header_in->pos = r->header_in->start;
        r->header_in->last = r->header_in->start;

        return NGX_OK;
    }

    old = request_line ? r->request_start : r->header_name_start;

    cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

    if (r->state != 0
        && (size_t) (r->header_in->pos - old)
                                     >= cscf->large_client_header_buffers.size)
    {
        return NGX_DECLINED;
    }

    hc = r->http_connection;

    if (hc->nfree) {
        b = hc->free[--hc->nfree];

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "http large header free: %p %uz",
                       b->pos, b->end - b->last);

    } else if (hc->nbusy < cscf->large_client_header_buffers.num) {

        if (hc->busy == NULL) {
            hc->busy = ngx_palloc(r->connection->pool,
                  cscf->large_client_header_buffers.num * sizeof(ngx_buf_t *));
            if (hc->busy == NULL) {
                return NGX_ERROR;
            }
        }

        b = ngx_create_temp_buf(r->connection->pool,
                                cscf->large_client_header_buffers.size);
        if (b == NULL) {
            return NGX_ERROR;
        }

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "http large header alloc: %p %uz",
                       b->pos, b->end - b->last);

    } else {
        return NGX_DECLINED;
    }

    hc->busy[hc->nbusy++] = b;

    if (r->state == 0) {
        /*
         * r->state == 0 means that a header line was parsed successfully
         * and we do not need to copy incomplete header line and
         * to relocate the parser header pointers
         */

        r->header_in = b;

        return NGX_OK;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http large header copy: %d", r->header_in->pos - old);

    new = b->start;

    ngx_memcpy(new, old, r->header_in->pos - old);

    b->pos = new + (r->header_in->pos - old);
    b->last = new + (r->header_in->pos - old);

    if (request_line) {
        r->request_start = new;

        if (r->request_end) {
            r->request_end = new + (r->request_end - old);
        }

        r->method_end = new + (r->method_end - old);

        r->uri_start = new + (r->uri_start - old);
        r->uri_end = new + (r->uri_end - old);

        if (r->schema_start) {
            r->schema_start = new + (r->schema_start - old);
            r->schema_end = new + (r->schema_end - old);
        }

        if (r->host_start) {
            r->host_start = new + (r->host_start - old);
            if (r->host_end) {
                r->host_end = new + (r->host_end - old);
            }
        }

        if (r->port_start) {
            r->port_start = new + (r->port_start - old);
            r->port_end = new + (r->port_end - old);
        }

        if (r->uri_ext) {
            r->uri_ext = new + (r->uri_ext - old);
        }

        if (r->args_start) {
            r->args_start = new + (r->args_start - old);
        }

        if (r->http_protocol.data) {
            r->http_protocol.data = new + (r->http_protocol.data - old);
        }

    } else {
        r->header_name_start = new;
        r->header_name_end = new + (r->header_name_end - old);
        r->header_start = new + (r->header_start - old);
        r->header_end = new + (r->header_end - old);
    }

    r->header_in = b;

    return NGX_OK;
}


static ngx_int_t
ngx_http_process_header_line(ngx_http_request_t *r, ngx_table_elt_t *h,
    ngx_uint_t offset)
{
    ngx_table_elt_t  **ph;

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

    if (*ph == NULL) {
        *ph = h;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_process_unique_header_line(ngx_http_request_t *r, ngx_table_elt_t *h,
    ngx_uint_t offset)
{
    ngx_table_elt_t  **ph;

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

    if (*ph == NULL) {
        *ph = h;
        return NGX_OK;
    }

    ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                  "client sent duplicate header line: \"%V: %V\", "
                  "previous value: \"%V: %V\"",
                  &h->key, &h->value, &(*ph)->key, &(*ph)->value);

    ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);

    return NGX_ERROR;
}


static ngx_int_t
ngx_http_process_host(ngx_http_request_t *r, ngx_table_elt_t *h,
    ngx_uint_t offset)
{
    ngx_int_t  rc;
    ngx_str_t  host;

    if (r->headers_in.host == NULL) {
        r->headers_in.host = h;
    }

    host = h->value;

    rc = ngx_http_validate_host(&host, r->pool, 0);

    if (rc == NGX_DECLINED) {
        ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                      "client sent invalid host header");
        ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
        return NGX_ERROR;
    }

    if (rc == NGX_ERROR) {
        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return NGX_ERROR;
    }

    if (r->headers_in.server.len) {
        return NGX_OK;
    }

    r->headers_in.server = host;

    return NGX_OK;
}


static ngx_int_t
ngx_http_process_connection(ngx_http_request_t *r, ngx_table_elt_t *h,
    ngx_uint_t offset)
{
    if (ngx_strcasestrn(h->value.data, "close", 5 - 1)) {
        r->headers_in.connection_type = NGX_HTTP_CONNECTION_CLOSE;

    } else if (ngx_strcasestrn(h->value.data, "keep-alive", 10 - 1)) {
        r->headers_in.connection_type = NGX_HTTP_CONNECTION_KEEP_ALIVE;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_process_user_agent(ngx_http_request_t *r, ngx_table_elt_t *h,
    ngx_uint_t offset)
{
    u_char  *user_agent, *msie;

    if (r->headers_in.user_agent) {
        return NGX_OK;
    }

    r->headers_in.user_agent = h;

    /* check some widespread browsers while the header is in CPU cache */

    user_agent = h->value.data;

    msie = ngx_strstrn(user_agent, "MSIE ", 5 - 1);

    if (msie && msie + 7 < user_agent + h->value.len) {

        r->headers_in.msie = 1;

        if (msie[6] == '.') {

            switch (msie[5]) {
            case '4':
            case '5':
                r->headers_in.msie6 = 1;
                break;
            case '6':
                if (ngx_strstrn(msie + 8, "SV1", 3 - 1) == NULL) {
                    r->headers_in.msie6 = 1;
                }
                break;
            }
        }

#if 0
        /* MSIE ignores the SSL "close notify" alert */
        if (c->ssl) {
            c->ssl->no_send_shutdown = 1;
        }
#endif
    }

    if (ngx_strstrn(user_agent, "Opera", 5 - 1)) {
        r->headers_in.opera = 1;
        r->headers_in.msie = 0;
        r->headers_in.msie6 = 0;
    }

    if (!r->headers_in.msie && !r->headers_in.opera) {

        if (ngx_strstrn(user_agent, "Gecko/", 6 - 1)) {
            r->headers_in.gecko = 1;

        } else if (ngx_strstrn(user_agent, "Chrome/", 7 - 1)) {
            r->headers_in.chrome = 1;

        } else if (ngx_strstrn(user_agent, "Safari/", 7 - 1)
                   && ngx_strstrn(user_agent, "Mac OS X", 8 - 1))
        {
            r->headers_in.safari = 1;

        } else if (ngx_strstrn(user_agent, "Konqueror", 9 - 1)) {
            r->headers_in.konqueror = 1;
        }
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_process_multi_header_lines(ngx_http_request_t *r, ngx_table_elt_t *h,
    ngx_uint_t offset)
{
    ngx_array_t       *headers;
    ngx_table_elt_t  **ph;

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

    if (headers->elts == NULL) {
        if (ngx_array_init(headers, r->pool, 1, sizeof(ngx_table_elt_t *))
            != NGX_OK)
        {
            ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
            return NGX_ERROR;
        }
    }

    ph = ngx_array_push(headers);
    if (ph == NULL) {
        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return NGX_ERROR;
    }

    *ph = h;
    return NGX_OK;
}


static ngx_int_t
ngx_http_process_request_header(ngx_http_request_t *r)
{
    if (ngx_http_set_virtual_server(r, &r->headers_in.server) == NGX_ERROR) {
        return NGX_ERROR;
    }

    if (r->headers_in.host == NULL && r->http_version > NGX_HTTP_VERSION_10) {
        ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                   "client sent HTTP/1.1 request without \"Host\" header");
        ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
        return NGX_ERROR;
    }

    if (r->headers_in.content_length) {
        r->headers_in.content_length_n =
                            ngx_atoof(r->headers_in.content_length->value.data,
                                      r->headers_in.content_length->value.len);

        if (r->headers_in.content_length_n == NGX_ERROR) {
            ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                          "client sent invalid \"Content-Length\" header");
            ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
            return NGX_ERROR;
        }
    }

    if (r->method & NGX_HTTP_TRACE) {
        ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                      "client sent TRACE method");
        ngx_http_finalize_request(r, NGX_HTTP_NOT_ALLOWED);
        return NGX_ERROR;
    }

    if (r->headers_in.transfer_encoding) {
        if (r->headers_in.transfer_encoding->value.len == 7
            && ngx_strncasecmp(r->headers_in.transfer_encoding->value.data,
                               (u_char *) "chunked", 7) == 0)
        {
            r->headers_in.content_length = NULL;
            r->headers_in.content_length_n = -1;
            r->headers_in.chunked = 1;

        } else if (r->headers_in.transfer_encoding->value.len != 8
            || ngx_strncasecmp(r->headers_in.transfer_encoding->value.data,
                               (u_char *) "identity", 8) != 0)
        {
            ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                          "client sent unknown \"Transfer-Encoding\": \"%V\"",
                          &r->headers_in.transfer_encoding->value);
            ngx_http_finalize_request(r, NGX_HTTP_NOT_IMPLEMENTED);
            return NGX_ERROR;
        }
    }

    if (r->headers_in.connection_type == NGX_HTTP_CONNECTION_KEEP_ALIVE) {
        if (r->headers_in.keep_alive) {
            r->headers_in.keep_alive_n =
                            ngx_atotm(r->headers_in.keep_alive->value.data,
                                      r->headers_in.keep_alive->value.len);
        }
    }

    return NGX_OK;
}


static void
ngx_http_process_request(ngx_http_request_t *r)
{
    ngx_connection_t  *c;

    c = r->connection;

    if (r->plain_http) {
        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "client sent plain HTTP request to HTTPS port");
        ngx_http_finalize_request(r, NGX_HTTP_TO_HTTPS);
        return;
    }

#if (NGX_HTTP_SSL)

    if (c->ssl) {
        long                      rc;
        X509                     *cert;
        ngx_http_ssl_srv_conf_t  *sscf;

        sscf = ngx_http_get_module_srv_conf(r, ngx_http_ssl_module);

        if (sscf->verify) {
            rc = SSL_get_verify_result(c->ssl->connection);

            if (rc != X509_V_OK
                && (sscf->verify != 3 || !ngx_ssl_verify_error_optional(rc)))
            {
                ngx_log_error(NGX_LOG_INFO, c->log, 0,
                              "client SSL certificate verify error: (%l:%s)",
                              rc, X509_verify_cert_error_string(rc));

                ngx_ssl_remove_cached_session(sscf->ssl.ctx,
                                       (SSL_get0_session(c->ssl->connection)));

                ngx_http_finalize_request(r, NGX_HTTPS_CERT_ERROR);
                return;
            }

            if (sscf->verify == 1) {
                cert = SSL_get_peer_certificate(c->ssl->connection);

                if (cert == NULL) {
                    ngx_log_error(NGX_LOG_INFO, c->log, 0,
                                  "client sent no required SSL certificate");

                    ngx_ssl_remove_cached_session(sscf->ssl.ctx,
                                       (SSL_get0_session(c->ssl->connection)));

                    ngx_http_finalize_request(r, NGX_HTTPS_NO_CERT);
                    return;
                }

                X509_free(cert);
            }
        }
    }

#endif

    if (c->read->timer_set) {
        ngx_del_timer(c->read);
    }

#if (NGX_STAT_STUB)
    (void) ngx_atomic_fetch_add(ngx_stat_reading, -1);
    r->stat_reading = 0;
    (void) ngx_atomic_fetch_add(ngx_stat_writing, 1);
    r->stat_writing = 1;
#endif

    c->read->handler = ngx_http_request_handler;
    c->write->handler = ngx_http_request_handler;
    r->read_event_handler = ngx_http_block_reading;

    ngx_http_handler(r);

    ngx_http_run_posted_requests(c);
}


static ngx_int_t
ngx_http_validate_host(ngx_str_t *host, ngx_pool_t *pool, ngx_uint_t alloc)
{
    u_char  *h, ch;
    size_t   i, dot_pos, host_len;

    enum {
        sw_usual = 0,
        sw_literal,
        sw_rest
    } state;

    dot_pos = host->len;
    host_len = host->len;

    h = host->data;

    state = sw_usual;

    for (i = 0; i < host->len; i++) {
        ch = h[i];

        switch (ch) {

        case '.':
            if (dot_pos == i - 1) {
                return NGX_DECLINED;
            }
            dot_pos = i;
            break;

        case ':':
            if (state == sw_usual) {
                host_len = i;
                state = sw_rest;
            }
            break;

        case '[':
            if (i == 0) {
                state = sw_literal;
            }
            break;

        case ']':
            if (state == sw_literal) {
                host_len = i + 1;
                state = sw_rest;
            }
            break;

        case '\0':
            return NGX_DECLINED;

        default:

            if (ngx_path_separator(ch)) {
                return NGX_DECLINED;
            }

            if (ch >= 'A' && ch <= 'Z') {
                alloc = 1;
            }

            break;
        }
    }

    if (dot_pos == host_len - 1) {
        host_len--;
    }

    if (host_len == 0) {
        return NGX_DECLINED;
    }

    if (alloc) {
        host->data = ngx_pnalloc(pool, host_len);
        if (host->data == NULL) {
            return NGX_ERROR;
        }

        ngx_strlow(host->data, h, host_len);
    }

    host->len = host_len;

    return NGX_OK;
}


static ngx_int_t
ngx_http_set_virtual_server(ngx_http_request_t *r, ngx_str_t *host)
{
    ngx_int_t                  rc;
    ngx_http_connection_t     *hc;
    ngx_http_core_loc_conf_t  *clcf;
    ngx_http_core_srv_conf_t  *cscf;

    hc = r->http_connection;

    rc = ngx_http_find_virtual_server(r->connection,
                                      hc->addr_conf->virtual_names,
                                      host, r, &cscf);

    if (rc == NGX_ERROR) {
        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return NGX_ERROR;
    }

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

    r->srv_conf = cscf->ctx->srv_conf;
    r->loc_conf = cscf->ctx->loc_conf;

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    ngx_http_set_connection_log(r->connection, clcf->error_log);

    return NGX_OK;
}


static ngx_int_t
ngx_http_find_virtual_server(ngx_connection_t *c,
    ngx_http_virtual_names_t *virtual_names, ngx_str_t *host,
    ngx_http_request_t *r, ngx_http_core_srv_conf_t **cscfp)
{
    ngx_http_core_srv_conf_t  *cscf;

    if (virtual_names == NULL) {
        return NGX_DECLINED;
    }

    cscf = ngx_hash_find_combined(&virtual_names->names,
                                  ngx_hash_key(host->data, host->len),
                                  host->data, host->len);

    if (cscf) {
        *cscfp = cscf;
        return NGX_OK;
    }

#if (NGX_PCRE)

    if (host->len && virtual_names->nregex) {
        ngx_int_t                n;
        ngx_uint_t               i;
        ngx_http_server_name_t  *sn;

        sn = virtual_names->regex;

#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME

        if (r == NULL) {
            for (i = 0; i < virtual_names->nregex; i++) {

                n = ngx_regex_exec(sn[i].regex->regex, host, NULL, 0);

                if (n == NGX_REGEX_NO_MATCHED) {
                    continue;
                }

                if (n >= 0) {
                    *cscfp = sn[i].server;
                    return NGX_OK;
                }

                ngx_log_error(NGX_LOG_ALERT, c->log, 0,
                              ngx_regex_exec_n " failed: %i "
                              "on \"%V\" using \"%V\"",
                              n, host, &sn[i].regex->name);

                return NGX_ERROR;
            }

            return NGX_DECLINED;
        }

#endif /* SSL_CTRL_SET_TLSEXT_HOSTNAME */

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

            n = ngx_http_regex_exec(r, sn[i].regex, host);

            if (n == NGX_DECLINED) {
                continue;
            }

            if (n == NGX_OK) {
                *cscfp = sn[i].server;
                return NGX_OK;
            }

            return NGX_ERROR;
        }
    }

#endif /* NGX_PCRE */

    return NGX_DECLINED;
}


static void
ngx_http_request_handler(ngx_event_t *ev)
{
    ngx_connection_t    *c;
    ngx_http_request_t  *r;
    ngx_http_log_ctx_t  *ctx;

    c = ev->data;
    r = c->data;

    ctx = c->log->data;
    ctx->current_request = r;

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http run request: \"%V?%V\"", &r->uri, &r->args);

    if (ev->write) {
        r->write_event_handler(r);

    } else {
        r->read_event_handler(r);
    }

    ngx_http_run_posted_requests(c);
}


void
ngx_http_run_posted_requests(ngx_connection_t *c)
{
    ngx_http_request_t         *r;
    ngx_http_log_ctx_t         *ctx;
    ngx_http_posted_request_t  *pr;

    for ( ;; ) {

        if (c->destroyed) {
            return;
        }

        r = c->data;
        pr = r->main->posted_requests;

        if (pr == NULL) {
            return;
        }

        r->main->posted_requests = pr->next;

        r = pr->request;

        ctx = c->log->data;
        ctx->current_request = r;

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                       "http posted request: \"%V?%V\"", &r->uri, &r->args);

        r->write_event_handler(r);
    }
}


ngx_int_t
ngx_http_post_request(ngx_http_request_t *r, ngx_http_posted_request_t *pr)
{
    ngx_http_posted_request_t  **p;

    if (pr == NULL) {
        pr = ngx_palloc(r->pool, sizeof(ngx_http_posted_request_t));
        if (pr == NULL) {
            return NGX_ERROR;
        }
    }

    pr->request = r;
    pr->next = NULL;

    for (p = &r->main->posted_requests; *p; p = &(*p)->next) { /* void */ }

    *p = pr;

    return NGX_OK;
}


void
ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc)
{
    ngx_connection_t          *c;
    ngx_http_request_t        *pr;
    ngx_http_core_loc_conf_t  *clcf;

    c = r->connection;

    ngx_log_debug5(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http finalize request: %d, \"%V?%V\" a:%d, c:%d",
                   rc, &r->uri, &r->args, r == c->data, r->main->count);

    if (rc == NGX_DONE) {
        ngx_http_finalize_connection(r);
        return;
    }

    if (rc == NGX_OK && r->filter_finalize) {
        c->error = 1;
    }

    if (rc == NGX_DECLINED) {
        r->content_handler = NULL;
        r->write_event_handler = ngx_http_core_run_phases;
        ngx_http_core_run_phases(r);
        return;
    }

    if (r != r->main && r->post_subrequest) {
        rc = r->post_subrequest->handler(r, r->post_subrequest->data, rc);
    }

    if (rc == NGX_ERROR
        || rc == NGX_HTTP_REQUEST_TIME_OUT
        || rc == NGX_HTTP_CLIENT_CLOSED_REQUEST
        || c->error)
    {
        if (ngx_http_post_action(r) == NGX_OK) {
            return;
        }

        if (r->main->blocked) {
            r->write_event_handler = ngx_http_request_finalizer;
        }

        ngx_http_terminate_request(r, rc);
        return;
    }

    if (rc >= NGX_HTTP_SPECIAL_RESPONSE
        || rc == NGX_HTTP_CREATED
        || rc == NGX_HTTP_NO_CONTENT)
    {
        if (rc == NGX_HTTP_CLOSE) {
            ngx_http_terminate_request(r, rc);
            return;
        }

        if (r == r->main) {
            if (c->read->timer_set) {
                ngx_del_timer(c->read);
            }

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

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

        ngx_http_finalize_request(r, ngx_http_special_response_handler(r, rc));
        return;
    }

    if (r != r->main) {

        if (r->buffered || r->postponed) {

            if (ngx_http_set_write_handler(r) != NGX_OK) {
                ngx_http_terminate_request(r, 0);
            }

            return;
        }

        pr = r->parent;

        if (r == c->data) {

            r->main->count--;
            r->main->subrequests++;

            if (!r->logged) {

                clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

                if (clcf->log_subrequest) {
                    ngx_http_log_request(r);
                }

                r->logged = 1;

            } else {
                ngx_log_error(NGX_LOG_ALERT, c->log, 0,
                              "subrequest: \"%V?%V\" logged again",
                              &r->uri, &r->args);
            }

            r->done = 1;

            if (pr->postponed && pr->postponed->request == r) {
                pr->postponed = pr->postponed->next;
            }

            c->data = pr;

        } else {

            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                           "http finalize non-active request: \"%V?%V\"",
                           &r->uri, &r->args);

            r->write_event_handler = ngx_http_request_finalizer;

            if (r->waited) {
                r->done = 1;
            }
        }

        if (ngx_http_post_request(pr, NULL) != NGX_OK) {
            r->main->count++;
            ngx_http_terminate_request(r, 0);
            return;
        }

        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                       "http wake parent request: \"%V?%V\"",
                       &pr->uri, &pr->args);

        return;
    }

    if (r->buffered || c->buffered || r->postponed || r->blocked) {

        if (ngx_http_set_write_handler(r) != NGX_OK) {
            ngx_http_terminate_request(r, 0);
        }

        return;
    }

    if (r != c->data) {
        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
                      "http finalize non-active request: \"%V?%V\"",
                      &r->uri, &r->args);
        return;
    }

    r->done = 1;
    r->write_event_handler = ngx_http_request_empty_handler;

    if (!r->post_action) {
        r->request_complete = 1;
    }

    if (ngx_http_post_action(r) == NGX_OK) {
        return;
    }

    if (c->read->timer_set) {
        ngx_del_timer(c->read);
    }

    if (c->write->timer_set) {
        c->write->delayed = 0;
        ngx_del_timer(c->write);
    }

    if (c->read->eof) {
        ngx_http_close_request(r, 0);
        return;
    }

    ngx_http_finalize_connection(r);
}


static void
ngx_http_terminate_request(ngx_http_request_t *r, ngx_int_t rc)
{
    ngx_http_cleanup_t    *cln;
    ngx_http_request_t    *mr;
    ngx_http_ephemeral_t  *e;

    mr = r->main;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http terminate request count:%d", mr->count);

    if (rc > 0 && (mr->headers_out.status == 0 || mr->connection->sent == 0)) {
        mr->headers_out.status = rc;
    }

    cln = mr->cleanup;
    mr->cleanup = NULL;

    while (cln) {
        if (cln->handler) {
            cln->handler(cln->data);
        }

        cln = cln->next;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http terminate cleanup count:%d blk:%d",
                   mr->count, mr->blocked);

    if (mr->write_event_handler) {

        if (mr->blocked) {
            return;
        }

        e = ngx_http_ephemeral(mr);
        mr->posted_requests = NULL;
        mr->write_event_handler = ngx_http_terminate_handler;
        (void) ngx_http_post_request(mr, &e->terminal_posted_request);
        return;
    }

    ngx_http_close_request(mr, rc);
}


static void
ngx_http_terminate_handler(ngx_http_request_t *r)
{
    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http terminate handler count:%d", r->count);

    r->count = 1;

    ngx_http_close_request(r, 0);
}


static void
ngx_http_finalize_connection(ngx_http_request_t *r)
{
    ngx_http_core_loc_conf_t  *clcf;

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    if (r->main->count != 1) {

        if (r->discard_body) {
            r->read_event_handler = ngx_http_discarded_request_body_handler;
            ngx_add_timer(r->connection->read, clcf->lingering_timeout);

            if (r->lingering_time == 0) {
                r->lingering_time = ngx_time()
                                      + (time_t) (clcf->lingering_time / 1000);
            }
        }

        ngx_http_close_request(r, 0);
        return;
    }

    if (!ngx_terminate
         && !ngx_exiting
         && r->keepalive
         && clcf->keepalive_timeout > 0)
    {
        ngx_http_set_keepalive(r);
        return;
    }

    if (clcf->lingering_close == NGX_HTTP_LINGERING_ALWAYS
        || (clcf->lingering_close == NGX_HTTP_LINGERING_ON
            && (r->lingering_close
                || r->header_in->pos < r->header_in->last
                || r->connection->read->ready)))
    {
        ngx_http_set_lingering_close(r);
        return;
    }

    ngx_http_close_request(r, 0);
}


static ngx_int_t
ngx_http_set_write_handler(ngx_http_request_t *r)
{
    ngx_event_t               *wev;
    ngx_http_core_loc_conf_t  *clcf;

    r->http_state = NGX_HTTP_WRITING_REQUEST_STATE;

    r->read_event_handler = r->discard_body ?
                                ngx_http_discarded_request_body_handler:
                                ngx_http_test_reading;
    r->write_event_handler = ngx_http_writer;

    wev = r->connection->write;

    if (wev->ready && wev->delayed) {
        return NGX_OK;
    }

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
    if (!wev->delayed) {
        ngx_add_timer(wev, clcf->send_timeout);
    }

    if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
        ngx_http_close_request(r, 0);
        return NGX_ERROR;
    }

    return NGX_OK;
}


static void
ngx_http_writer(ngx_http_request_t *r)
{
    int                        rc;
    ngx_event_t               *wev;
    ngx_connection_t          *c;
    ngx_http_core_loc_conf_t  *clcf;

    c = r->connection;
    wev = c->write;

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, wev->log, 0,
                   "http writer handler: \"%V?%V\"", &r->uri, &r->args);

    clcf = ngx_http_get_module_loc_conf(r->main, ngx_http_core_module);

    if (wev->timedout) {
        if (!wev->delayed) {
            ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT,
                          "client timed out");
            c->timedout = 1;

            ngx_http_finalize_request(r, NGX_HTTP_REQUEST_TIME_OUT);
            return;
        }

        wev->timedout = 0;
        wev->delayed = 0;

        if (!wev->ready) {
            ngx_add_timer(wev, clcf->send_timeout);

            if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
                ngx_http_close_request(r, 0);
            }

            return;
        }

    }

    if (wev->delayed || r->aio) {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, wev->log, 0,
                       "http writer delayed");

        if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
            ngx_http_close_request(r, 0);
        }

        return;
    }

    rc = ngx_http_output_filter(r, NULL);

    ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http writer output filter: %d, \"%V?%V\"",
                   rc, &r->uri, &r->args);

    if (rc == NGX_ERROR) {
        ngx_http_finalize_request(r, rc);
        return;
    }

    if (r->buffered || r->postponed || (r == r->main && c->buffered)) {

        if (!wev->delayed) {
            ngx_add_timer(wev, clcf->send_timeout);
        }

        if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
            ngx_http_close_request(r, 0);
        }

        return;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, wev->log, 0,
                   "http writer done: \"%V?%V\"", &r->uri, &r->args);

    r->write_event_handler = ngx_http_request_empty_handler;

    ngx_http_finalize_request(r, rc);
}


static void
ngx_http_request_finalizer(ngx_http_request_t *r)
{
    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http finalizer done: \"%V?%V\"", &r->uri, &r->args);

    ngx_http_finalize_request(r, 0);
}


void
ngx_http_block_reading(ngx_http_request_t *r)
{
    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http reading blocked");

    /* aio does not call this handler */

    if ((ngx_event_flags & NGX_USE_LEVEL_EVENT)
        && r->connection->read->active)
    {
        if (ngx_del_event(r->connection->read, NGX_READ_EVENT, 0) != NGX_OK) {
            ngx_http_close_request(r, 0);
        }
    }
}


void
ngx_http_test_reading(ngx_http_request_t *r)
{
    int                n;
    char               buf[1];
    ngx_err_t          err;
    ngx_event_t       *rev;
    ngx_connection_t  *c;

    c = r->connection;
    rev = c->read;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http test reading");

#if (NGX_HAVE_KQUEUE)

    if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {

        if (!rev->pending_eof) {
            return;
        }

        rev->eof = 1;
        c->error = 1;
        err = rev->kq_errno;

        goto closed;
    }

#endif

    n = recv(c->fd, buf, 1, MSG_PEEK);

    if (n == 0) {
        rev->eof = 1;
        c->error = 1;
        err = 0;

        goto closed;

    } else if (n == -1) {
        err = ngx_socket_errno;

        if (err != NGX_EAGAIN) {
            rev->eof = 1;
            c->error = 1;

            goto closed;
        }
    }

    /* aio does not call this handler */

    if ((ngx_event_flags & NGX_USE_LEVEL_EVENT) && rev->active) {

        if (ngx_del_event(rev, NGX_READ_EVENT, 0) != NGX_OK) {
            ngx_http_close_request(r, 0);
        }
    }

    return;

closed:

    if (err) {
        rev->error = 1;
    }

    ngx_log_error(NGX_LOG_INFO, c->log, err,
                  "client prematurely closed connection");

    ngx_http_finalize_request(r, 0);
}


static void
ngx_http_set_keepalive(ngx_http_request_t *r)
{
    int                        tcp_nodelay;
    ngx_int_t                  i;
    ngx_buf_t                 *b, *f;
    ngx_event_t               *rev, *wev;
    ngx_connection_t          *c;
    ngx_http_connection_t     *hc;
    ngx_http_core_srv_conf_t  *cscf;
    ngx_http_core_loc_conf_t  *clcf;

    c = r->connection;
    rev = c->read;

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "set http keepalive handler");

    if (r->discard_body) {
        r->write_event_handler = ngx_http_request_empty_handler;
        r->lingering_time = ngx_time() + (time_t) (clcf->lingering_time / 1000);
        ngx_add_timer(rev, clcf->lingering_timeout);
        return;
    }

    c->log->action = "closing request";

    hc = r->http_connection;
    b = r->header_in;

    if (b->pos < b->last) {

        /* the pipelined request */

        if (b != c->buffer) {

            /*
             * If the large header buffers were allocated while the previous
             * request processing then we do not use c->buffer for
             * the pipelined request (see ngx_http_init_request()).
             *
             * Now we would move the large header buffers to the free list.
             */

            cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

            if (hc->free == NULL) {
                hc->free = ngx_palloc(c->pool,
                  cscf->large_client_header_buffers.num * sizeof(ngx_buf_t *));

                if (hc->free == NULL) {
                    ngx_http_close_request(r, 0);
                    return;
                }
            }

            for (i = 0; i < hc->nbusy - 1; i++) {
                f = hc->busy[i];
                hc->free[hc->nfree++] = f;
                f->pos = f->start;
                f->last = f->start;
            }

            hc->busy[0] = b;
            hc->nbusy = 1;
        }
    }

    r->keepalive = 0;

    ngx_http_free_request(r, 0);

    c->data = hc;

    ngx_add_timer(rev, clcf->keepalive_timeout);

    if (ngx_handle_read_event(rev, 0) != NGX_OK) {
        ngx_http_close_connection(c);
        return;
    }

    wev = c->write;
    wev->handler = ngx_http_empty_handler;

    if (b->pos < b->last) {

        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "pipelined request");

#if (NGX_STAT_STUB)
        (void) ngx_atomic_fetch_add(ngx_stat_reading, 1);
#endif

        hc->pipeline = 1;
        c->log->action = "reading client pipelined request line";

        rev->handler = ngx_http_init_request;
        ngx_post_event(rev, &ngx_posted_events);
        return;
    }

    hc->pipeline = 0;

    /*
     * To keep a memory footprint as small as possible for an idle
     * keepalive connection we try to free the ngx_http_request_t and
     * c->buffer's memory if they were allocated outside the c->pool.
     * The large header buffers are always allocated outside the c->pool and
     * are freed too.
     */

    if (ngx_pfree(c->pool, r) == NGX_OK) {
        hc->request = NULL;
    }

    b = c->buffer;

    if (ngx_pfree(c->pool, b->start) == NGX_OK) {

        /*
         * the special note for ngx_http_keepalive_handler() that
         * c->buffer's memory was freed
         */

        b->pos = NULL;

    } else {
        b->pos = b->start;
        b->last = b->start;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0, "hc free: %p %d",
                   hc->free, hc->nfree);

    if (hc->free) {
        for (i = 0; i < hc->nfree; i++) {
            ngx_pfree(c->pool, hc->free[i]->start);
            hc->free[i] = NULL;
        }

        hc->nfree = 0;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0, "hc busy: %p %d",
                   hc->busy, hc->nbusy);

    if (hc->busy) {
        for (i = 0; i < hc->nbusy; i++) {
            ngx_pfree(c->pool, hc->busy[i]->start);
            hc->busy[i] = NULL;
        }

        hc->nbusy = 0;
    }

#if (NGX_HTTP_SSL)
    if (c->ssl) {
        ngx_ssl_free_buffer(c);
    }
#endif

    rev->handler = ngx_http_keepalive_handler;

    if (wev->active && (ngx_event_flags & NGX_USE_LEVEL_EVENT)) {
        if (ngx_del_event(wev, NGX_WRITE_EVENT, 0) != NGX_OK) {
            ngx_http_close_connection(c);
            return;
        }
    }

    c->log->action = "keepalive";

    if (c->tcp_nopush == NGX_TCP_NOPUSH_SET) {
        if (ngx_tcp_push(c->fd) == -1) {
            ngx_connection_error(c, ngx_socket_errno, ngx_tcp_push_n " failed");
            ngx_http_close_connection(c);
            return;
        }

        c->tcp_nopush = NGX_TCP_NOPUSH_UNSET;
        tcp_nodelay = ngx_tcp_nodelay_and_tcp_nopush ? 1 : 0;

    } else {
        tcp_nodelay = 1;
    }

    if (tcp_nodelay
        && clcf->tcp_nodelay
        && c->tcp_nodelay == NGX_TCP_NODELAY_UNSET)
    {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "tcp_nodelay");

        if (setsockopt(c->fd, IPPROTO_TCP, TCP_NODELAY,
                       (const void *) &tcp_nodelay, sizeof(int))
            == -1)
        {
#if (NGX_SOLARIS)
            /* Solaris returns EINVAL if a socket has been shut down */
            c->log_error = NGX_ERROR_IGNORE_EINVAL;
#endif

            ngx_connection_error(c, ngx_socket_errno,
                                 "setsockopt(TCP_NODELAY) failed");

            c->log_error = NGX_ERROR_INFO;
            ngx_http_close_connection(c);
            return;
        }

        c->tcp_nodelay = NGX_TCP_NODELAY_SET;
    }

#if 0
    /* if ngx_http_request_t was freed then we need some other place */
    r->http_state = NGX_HTTP_KEEPALIVE_STATE;
#endif

    c->idle = 1;
    ngx_reusable_connection(c, 1);

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


static void
ngx_http_keepalive_handler(ngx_event_t *rev)
{
    size_t             size;
    ssize_t            n;
    ngx_buf_t         *b;
    ngx_connection_t  *c;

    c = rev->data;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http keepalive handler");

    if (rev->timedout || c->close) {
        ngx_http_close_connection(c);
        return;
    }

#if (NGX_HAVE_KQUEUE)

    if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
        if (rev->pending_eof) {
            c->log->handler = NULL;
            ngx_log_error(NGX_LOG_INFO, c->log, rev->kq_errno,
                          "kevent() reported that client %V closed "
                          "keepalive connection", &c->addr_text);
#if (NGX_HTTP_SSL)
            if (c->ssl) {
                c->ssl->no_send_shutdown = 1;
            }
#endif
            ngx_http_close_connection(c);
            return;
        }
    }

#endif

    b = c->buffer;
    size = b->end - b->start;

    if (b->pos == NULL) {

        /*
         * The c->buffer's memory was freed by ngx_http_set_keepalive().
         * However, the c->buffer->start and c->buffer->end were not changed
         * to keep the buffer size.
         */

        b->pos = ngx_palloc(c->pool, size);
        if (b->pos == NULL) {
            ngx_http_close_connection(c);
            return;
        }

        b->start = b->pos;
        b->last = b->pos;
        b->end = b->pos + size;
    }

    /*
     * MSIE closes a keepalive connection with RST flag
     * so we ignore ECONNRESET here.
     */

    c->log_error = NGX_ERROR_IGNORE_ECONNRESET;
    ngx_set_socket_errno(0);

    n = c->recv(c, b->last, size);
    c->log_error = NGX_ERROR_INFO;

    if (n == NGX_AGAIN) {
        if (ngx_handle_read_event(rev, 0) != NGX_OK) {
            ngx_http_close_connection(c);
            return;
        }

        /*
         * Like ngx_http_set_keepalive() we are trying to not hold
         * c->buffer's memory for a keepalive connection.
         */

        if (ngx_pfree(c->pool, b->start) == NGX_OK) {

            /*
             * the special note that c->buffer's memory was freed
             */

            b->pos = NULL;
        }

        return;
    }

    if (n == NGX_ERROR) {
        ngx_http_close_connection(c);
        return;
    }

    c->log->handler = NULL;

    if (n == 0) {
        ngx_log_error(NGX_LOG_INFO, c->log, ngx_socket_errno,
                      "client %V closed keepalive connection", &c->addr_text);
        ngx_http_close_connection(c);
        return;
    }

    b->last += n;

#if (NGX_STAT_STUB)
    (void) ngx_atomic_fetch_add(ngx_stat_reading, 1);
#endif

    c->log->handler = ngx_http_log_error;
    c->log->action = "reading client request line";

    c->idle = 0;
    ngx_reusable_connection(c, 0);

    ngx_http_init_request(rev);
}


static void
ngx_http_set_lingering_close(ngx_http_request_t *r)
{
    ngx_event_t               *rev, *wev;
    ngx_connection_t          *c;
    ngx_http_core_loc_conf_t  *clcf;

    c = r->connection;

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    rev = c->read;
    rev->handler = ngx_http_lingering_close_handler;

    r->lingering_time = ngx_time() + (time_t) (clcf->lingering_time / 1000);
    ngx_add_timer(rev, clcf->lingering_timeout);

    if (ngx_handle_read_event(rev, 0) != NGX_OK) {
        ngx_http_close_request(r, 0);
        return;
    }

    wev = c->write;
    wev->handler = ngx_http_empty_handler;

    if (wev->active && (ngx_event_flags & NGX_USE_LEVEL_EVENT)) {
        if (ngx_del_event(wev, NGX_WRITE_EVENT, 0) != NGX_OK) {
            ngx_http_close_request(r, 0);
            return;
        }
    }

    if (ngx_shutdown_socket(c->fd, NGX_WRITE_SHUTDOWN) == -1) {
        ngx_connection_error(c, ngx_socket_errno,
                             ngx_shutdown_socket_n " failed");
        ngx_http_close_request(r, 0);
        return;
    }

    if (rev->ready) {
        ngx_http_lingering_close_handler(rev);
    }
}


static void
ngx_http_lingering_close_handler(ngx_event_t *rev)
{
    ssize_t                    n;
    ngx_msec_t                 timer;
    ngx_connection_t          *c;
    ngx_http_request_t        *r;
    ngx_http_core_loc_conf_t  *clcf;
    u_char                     buffer[NGX_HTTP_LINGERING_BUFFER_SIZE];

    c = rev->data;
    r = c->data;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http lingering close handler");

    if (rev->timedout) {
        ngx_http_close_request(r, 0);
        return;
    }

    timer = (ngx_msec_t) (r->lingering_time - ngx_time());
    if (timer <= 0) {
        ngx_http_close_request(r, 0);
        return;
    }

    do {
        n = c->recv(c, buffer, NGX_HTTP_LINGERING_BUFFER_SIZE);

        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "lingering read: %d", n);

        if (n == NGX_ERROR || n == 0) {
            ngx_http_close_request(r, 0);
            return;
        }

    } while (rev->ready);

    if (ngx_handle_read_event(rev, 0) != NGX_OK) {
        ngx_http_close_request(r, 0);
        return;
    }

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    timer *= 1000;

    if (timer > clcf->lingering_timeout) {
        timer = clcf->lingering_timeout;
    }

    ngx_add_timer(rev, timer);
}


void
ngx_http_empty_handler(ngx_event_t *wev)
{
    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, wev->log, 0, "http empty handler");

    return;
}


void
ngx_http_request_empty_handler(ngx_http_request_t *r)
{
    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http request empty handler");

    return;
}


ngx_int_t
ngx_http_send_special(ngx_http_request_t *r, ngx_uint_t flags)
{
    ngx_buf_t    *b;
    ngx_chain_t   out;

    b = ngx_calloc_buf(r->pool);
    if (b == NULL) {
        return NGX_ERROR;
    }

    if (flags & NGX_HTTP_LAST) {

        if (r == r->main && !r->post_action) {
            b->last_buf = 1;

        } else {
            b->sync = 1;
            b->last_in_chain = 1;
        }
    }

    if (flags & NGX_HTTP_FLUSH) {
        b->flush = 1;
    }

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

    return ngx_http_output_filter(r, &out);
}


static ngx_int_t
ngx_http_post_action(ngx_http_request_t *r)
{
    ngx_http_core_loc_conf_t  *clcf;

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    if (clcf->post_action.data == NULL) {
        return NGX_DECLINED;
    }

    if (r->post_action && r->uri_changes == 0) {
        return NGX_DECLINED;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "post action: \"%V\"", &clcf->post_action);

    r->main->count--;

    r->http_version = NGX_HTTP_VERSION_9;
    r->header_only = 1;
    r->post_action = 1;

    r->read_event_handler = ngx_http_block_reading;

    if (clcf->post_action.data[0] == '/') {
        ngx_http_internal_redirect(r, &clcf->post_action, NULL);

    } else {
        ngx_http_named_location(r, &clcf->post_action);
    }

    return NGX_OK;
}


static void
ngx_http_close_request(ngx_http_request_t *r, ngx_int_t rc)
{
    ngx_connection_t  *c;

    r = r->main;
    c = r->connection;

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http request count:%d blk:%d", r->count, r->blocked);

    if (r->count == 0) {
        ngx_log_error(NGX_LOG_ALERT, c->log, 0, "http request count is zero");
    }

    r->count--;

    if (r->count || r->blocked) {
        return;
    }

    ngx_http_free_request(r, rc);
    ngx_http_close_connection(c);
}


static void
ngx_http_free_request(ngx_http_request_t *r, ngx_int_t rc)
{
    ngx_log_t                 *log;
    struct linger              linger;
    ngx_http_cleanup_t        *cln;
    ngx_http_log_ctx_t        *ctx;
    ngx_http_core_loc_conf_t  *clcf;

    log = r->connection->log;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, log, 0, "http close request");

    if (r->pool == NULL) {
        ngx_log_error(NGX_LOG_ALERT, log, 0, "http request already closed");
        return;
    }

    for (cln = r->cleanup; cln; cln = cln->next) {
        if (cln->handler) {
            cln->handler(cln->data);
        }
    }

#if (NGX_STAT_STUB)

    if (r->stat_reading) {
        (void) ngx_atomic_fetch_add(ngx_stat_reading, -1);
    }

    if (r->stat_writing) {
        (void) ngx_atomic_fetch_add(ngx_stat_writing, -1);
    }

#endif

    if (rc > 0 && (r->headers_out.status == 0 || r->connection->sent == 0)) {
        r->headers_out.status = rc;
    }

    log->action = "logging request";

    ngx_http_log_request(r);

    log->action = "closing request";

    if (r->connection->timedout) {
        clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

        if (clcf->reset_timedout_connection) {
            linger.l_onoff = 1;
            linger.l_linger = 0;

            if (setsockopt(r->connection->fd, SOL_SOCKET, SO_LINGER,
                           (const void *) &linger, sizeof(struct linger)) == -1)
            {
                ngx_log_error(NGX_LOG_ALERT, log, ngx_socket_errno,
                              "setsockopt(SO_LINGER) failed");
            }
        }
    }

    /* the various request strings were allocated from r->pool */
    ctx = log->data;
    ctx->request = NULL;

    r->request_line.len = 0;

    r->connection->destroyed = 1;

    ngx_destroy_pool(r->pool);
}


static void
ngx_http_log_request(ngx_http_request_t *r)
{
    ngx_uint_t                  i, n;
    ngx_http_handler_pt        *log_handler;
    ngx_http_core_main_conf_t  *cmcf;

    cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

    log_handler = cmcf->phases[NGX_HTTP_LOG_PHASE].handlers.elts;
    n = cmcf->phases[NGX_HTTP_LOG_PHASE].handlers.nelts;

    for (i = 0; i < n; i++) {
        log_handler[i](r);
    }
}


static void
ngx_http_close_connection(ngx_connection_t *c)
{
    ngx_pool_t  *pool;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "close http connection: %d", c->fd);

#if (NGX_HTTP_SSL)

    if (c->ssl) {
        if (ngx_ssl_shutdown(c) == NGX_AGAIN) {
            c->ssl->handler = ngx_http_close_connection;
            return;
        }
    }

#endif

#if (NGX_STAT_STUB)
    (void) ngx_atomic_fetch_add(ngx_stat_active, -1);
#endif

    c->destroyed = 1;

    pool = c->pool;

    ngx_close_connection(c);

    ngx_destroy_pool(pool);
}


static u_char *
ngx_http_log_error(ngx_log_t *log, u_char *buf, size_t len)
{
    u_char              *p;
    ngx_http_request_t  *r;
    ngx_http_log_ctx_t  *ctx;

    if (log->action) {
        p = ngx_snprintf(buf, len, " while %s", log->action);
        len -= p - buf;
        buf = p;
    }

    ctx = log->data;

    p = ngx_snprintf(buf, len, ", client: %V", &ctx->connection->addr_text);
    len -= p - buf;

    r = ctx->request;

    if (r) {
        return r->log_handler(r, ctx->current_request, p, len);

    } else {
        p = ngx_snprintf(p, len, ", server: %V",
                         &ctx->connection->listening->addr_text);
    }

    return p;
}


static u_char *
ngx_http_log_error_handler(ngx_http_request_t *r, ngx_http_request_t *sr,
    u_char *buf, size_t len)
{
    char                      *uri_separator;
    u_char                    *p;
    ngx_http_upstream_t       *u;
    ngx_http_core_srv_conf_t  *cscf;

    cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

    p = ngx_snprintf(buf, len, ", server: %V", &cscf->server_name);
    len -= p - buf;
    buf = p;

    if (r->request_line.data == NULL && r->request_start) {
        for (p = r->request_start; p < r->header_in->last; p++) {
            if (*p == CR || *p == LF) {
                break;
            }
        }

        r->request_line.len = p - r->request_start;
        r->request_line.data = r->request_start;
    }

    if (r->request_line.len) {
        p = ngx_snprintf(buf, len, ", request: \"%V\"", &r->request_line);
        len -= p - buf;
        buf = p;
    }

    if (r != sr) {
        p = ngx_snprintf(buf, len, ", subrequest: \"%V\"", &sr->uri);
        len -= p - buf;
        buf = p;
    }

    u = sr->upstream;

    if (u && u->peer.name) {

        uri_separator = "";

#if (NGX_HAVE_UNIX_DOMAIN)
        if (u->peer.sockaddr && u->peer.sockaddr->sa_family == AF_UNIX) {
            uri_separator = ":";
        }
#endif

        p = ngx_snprintf(buf, len, ", upstream: \"%V%V%s%V\"",
                         &u->schema, u->peer.name,
                         uri_separator, &u->uri);
        len -= p - buf;
        buf = p;
    }

    if (r->headers_in.host) {
        p = ngx_snprintf(buf, len, ", host: \"%V\"",
                         &r->headers_in.host->value);
        len -= p - buf;
        buf = p;
    }

    if (r->headers_in.referer) {
        p = ngx_snprintf(buf, len, ", referrer: \"%V\"",
                         &r->headers_in.referer->value);
        buf = p;
    }

    return buf;
}