nginx-0.0.1-2003-11-03-20:33:31 import

1 files changed, 1068 insertions, 3 deletions

diff --git a/src/http/modules/proxy/ngx_http_proxy_upstream.c b/src/http/modules/proxy/ngx_http_proxy_upstream.c
index 532e313d6..f969f33f0 100644
--- a/src/http/modules/proxy/ngx_http_proxy_upstream.c
+++ b/src/http/modules/proxy/ngx_http_proxy_upstream.c
@@ -8,12 +8,279 @@
 #include <ngx_http_proxy_handler.h>
 
 
-void ngx_http_proxy_reinit_upstream(ngx_http_proxy_ctx_t *p)
+static ngx_chain_t *ngx_http_proxy_create_request(ngx_http_proxy_ctx_t *p);
+static void ngx_http_proxy_init_upstream(void *data);
+static void ngx_http_proxy_reinit_upstream(ngx_http_proxy_ctx_t *p);
+static void ngx_http_proxy_connect(ngx_http_proxy_ctx_t *p);
+static void ngx_http_proxy_send_request(ngx_http_proxy_ctx_t *p);
+static void ngx_http_proxy_send_request_handler(ngx_event_t *wev);
+static void ngx_http_proxy_dummy_handler(ngx_event_t *wev);
+static void ngx_http_proxy_process_upstream_status_line(ngx_event_t *rev);
+static void ngx_http_proxy_process_upstream_headers(ngx_event_t *rev);
+static void ngx_http_proxy_process_upstream_header(ngx_http_proxy_ctx_t *p);
+static ssize_t ngx_http_proxy_read_upstream_header(ngx_http_proxy_ctx_t *);
+static void ngx_http_proxy_send_response(ngx_http_proxy_ctx_t *p);
+static void ngx_http_proxy_process_body(ngx_event_t *ev);
+static void ngx_http_proxy_next_upstream(ngx_http_proxy_ctx_t *p, int ft_type);
+
+
+static ngx_str_t http_methods[] = {
+    ngx_string("GET "),
+    ngx_string("HEAD "),
+    ngx_string("POST ")
+};
+
+
+static char *upstream_header_errors[] = {
+    "upstream sent invalid header",
+    "upstream sent too long header line"
+};
+
+
+static char  http_version[] = " HTTP/1.0" CRLF;
+static char  host_header[] = "Host: ";
+static char  connection_close_header[] = "Connection: close" CRLF;
+
+
+int ngx_http_proxy_request_upstream(ngx_http_proxy_ctx_t *p)
+{
+    int                         rc;
+    ngx_http_request_t         *r;
+    ngx_http_proxy_upstream_t  *u;
+
+    r = p->request;
+
+    if (!(u = ngx_pcalloc(r->pool, sizeof(ngx_http_proxy_upstream_t)))) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    p->upstream = u;
+
+    u->peer.peers = p->lcf->peers;
+    u->peer.tries = p->lcf->peers->number;
+
+    ngx_init_array(p->states, r->pool, u->peer.tries,
+                   sizeof(ngx_http_proxy_state_t),
+                   NGX_HTTP_INTERNAL_SERVER_ERROR);
+
+    u->method = r->method;
+
+    /* STUB */ p->cachable = p->lcf->cache;
+
+    if (r->headers_in.content_length_n > 0) {
+        if (!(r->temp_file = ngx_pcalloc(r->pool, sizeof(ngx_temp_file_t)))) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        r->temp_file->file.fd = NGX_INVALID_FILE;
+        r->temp_file->file.log = r->connection->log;
+        r->temp_file->path = p->lcf->temp_path;
+        r->temp_file->pool = r->pool;
+        r->temp_file->warn = "a client request body is buffered "
+                             "to a temporary file";
+        /* r->temp_file->persistent = 0; */
+
+        r->request_body_handler = ngx_http_proxy_init_upstream;
+        r->data = p;
+
+        rc = ngx_http_read_client_request_body(r, p->lcf->request_buffer_size);
+
+        if (rc == NGX_AGAIN) {
+            return NGX_DONE;
+        }
+
+        if (rc == NGX_ERROR) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+    }
+
+    ngx_http_proxy_init_upstream(p);
+
+    return NGX_DONE;
+}
+
+
+static ngx_chain_t *ngx_http_proxy_create_request(ngx_http_proxy_ctx_t *p)
+{
+    int                              i;
+    size_t                           len;
+    ngx_hunk_t                      *h;
+    ngx_chain_t                     *chain;
+    ngx_table_elt_t                 *header;
+    ngx_http_request_t              *r;
+    ngx_http_proxy_upstream_conf_t  *uc;
+
+    r = p->request;
+    uc = p->lcf->upstream;
+
+    len = http_methods[p->upstream->method - 1].len
+          + uc->uri.len
+          + r->uri.len - uc->location->len
+          + 1 + r->args.len                                  /* 1 is for "?" */
+          + sizeof(http_version) - 1
+          + sizeof(host_header) - 1 + uc->host_header.len + 2
+                                                          /* 2 is for "\r\n" */
+          + sizeof(connection_close_header) - 1
+          + 2;                          /* 2 is for "\r\n" at the header end */
+
+    header = (ngx_table_elt_t *) r->headers_in.headers->elts;
+    for (i = 0; i < r->headers_in.headers->nelts; i++) {
+
+        if (&header[i] == r->headers_in.host) {
+            continue;
+        }
+
+        if (&header[i] == r->headers_in.connection) {
+            continue;
+        }
+
+        /* 2 is for ": " and 2 is for "\r\n" */
+        len += header[i].key.len + 2 + header[i].value.len + 2;
+    }
+
+    /* STUB */ len++;
+
+    ngx_test_null(h, ngx_create_temp_hunk(r->pool, len), NULL);
+    ngx_alloc_link_and_set_hunk(chain, h, r->pool, NULL);
+
+
+    /* the request line */
+
+    h->last = ngx_cpymem(h->last, http_methods[p->upstream->method - 1].data,
+                         http_methods[p->upstream->method - 1].len);
+
+    h->last = ngx_cpymem(h->last, uc->uri.data, uc->uri.len);
+
+    h->last = ngx_cpymem(h->last,
+                         r->uri.data + uc->location->len,
+                         r->uri.len - uc->location->len);
+
+    if (r->args.len > 0) {
+        *(h->last++) = '?';
+        h->last = ngx_cpymem(h->last, r->args.data, r->args.len);
+    }
+
+    h->last = ngx_cpymem(h->last, http_version, sizeof(http_version) - 1);
+
+
+    /* "Host" header */
+
+    h->last = ngx_cpymem(h->last, host_header, sizeof(host_header) - 1);
+    h->last = ngx_cpymem(h->last, uc->host_header.data, uc->host_header.len);
+    *(h->last++) = CR; *(h->last++) = LF;
+
+
+    /* "Connection: close" header */
+
+    h->last = ngx_cpymem(h->last, connection_close_header,
+                         sizeof(connection_close_header) - 1);
+
+
+    for (i = 0; i < r->headers_in.headers->nelts; i++) {
+
+        if (&header[i] == r->headers_in.host) {
+            continue;
+        }
+
+        if (&header[i] == r->headers_in.connection) {
+            continue;
+        }
+
+        if (&header[i] == r->headers_in.keep_alive) {
+            continue;
+        }
+
+        h->last = ngx_cpymem(h->last, header[i].key.data, header[i].key.len);
+
+        *(h->last++) = ':'; *(h->last++) = ' ';
+
+        h->last = ngx_cpymem(h->last, header[i].value.data,
+                             header[i].value.len);
+
+        *(h->last++) = CR; *(h->last++) = LF;
+
+        ngx_log_debug(r->connection->log, "proxy: '%s: %s'" _
+                      header[i].key.data _ header[i].value.data);
+    }
+
+    /* add "\r\n" at the header end */
+    *(h->last++) = CR; *(h->last++) = LF;
+
+    /* STUB */ *(h->last) = '\0';
+    ngx_log_debug(r->connection->log, "PROXY:\n'%s'" _ h->pos);
+
+    return chain;
+}
+
+
+static void ngx_http_proxy_init_upstream(void *data)
 {
+    ngx_http_proxy_ctx_t *p = data;
+
     ngx_chain_t             *cl;
+    ngx_http_request_t      *r;
     ngx_output_chain_ctx_t  *octx;
+    ngx_chain_writer_ctx_t  *wctx;
+
+    r = p->request;
+
+ngx_log_debug(r->connection->log, "timer_set: %d" _
+              r->connection->read->timer_set);
+
+    if (r->connection->read->timer_set) {
+        ngx_del_timer(r->connection->read);
+    }
+
+    if (!(cl = ngx_http_proxy_create_request(p))) {
+        ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        return;
+    }
+
+    if (r->request_hunks) {
+        cl->next = r->request_hunks;
+    }
+
+    r->request_hunks = cl;
 
-    octx = p->output_chain_ctx;
+    p->upstream->peer.log = r->connection->log;
+    p->saved_ctx = r->connection->log->data;
+    p->saved_handler = r->connection->log->handler;
+    r->connection->log->data = p;
+    r->connection->log->handler = ngx_http_proxy_log_error;
+    p->action = "connecting to upstream";
+
+    if (!(octx = ngx_pcalloc(r->pool, sizeof(ngx_output_chain_ctx_t)))) {
+        ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        return;
+    }
+
+    p->upstream->output_chain_ctx = octx;
+
+    octx->sendfile = r->sendfile;
+    octx->pool = r->pool;
+    octx->bufs.num = 1;
+    octx->tag = (ngx_hunk_tag_t) &ngx_http_proxy_module;
+    octx->output_filter = (ngx_output_chain_filter_pt) ngx_chain_writer;
+
+    if (!(wctx = ngx_palloc(r->pool, sizeof(ngx_chain_writer_ctx_t)))) {
+        ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        return;
+    }
+
+    octx->output_ctx = wctx;
+
+    wctx->pool = r->pool;
+
+    ngx_http_proxy_connect(p);
+}
+
+
+static void ngx_http_proxy_reinit_upstream(ngx_http_proxy_ctx_t *p)
+{
+    ngx_chain_t             *cl;
+    ngx_output_chain_ctx_t  *octx;
+
+    octx = p->upstream->output_chain_ctx;
 
     /* reinit the request chain */
 
@@ -32,7 +299,7 @@ void ngx_http_proxy_reinit_upstream(ngx_http_proxy_ctx_t *p)
 
     if (p->header_in) {
         if (p->cache) {
-            p->header_in->pos = p->header_in->start + p->cache->ctx.header.size;
+            p->header_in->pos = p->header_in->start + p->cache->ctx.header_size;
             p->header_in->last = p->header_in->pos;
 
         } else {
@@ -41,3 +308,801 @@ void ngx_http_proxy_reinit_upstream(ngx_http_proxy_ctx_t *p)
         }
     }
 }
+
+
+static void ngx_http_proxy_connect(ngx_http_proxy_ctx_t *p)
+{
+    int                      rc;
+    ngx_chain_t             *cl;
+    ngx_connection_t        *c;
+    ngx_http_request_t      *r;
+    ngx_output_chain_ctx_t  *octx;
+
+    p->action = "connecting to upstream";
+
+    rc = ngx_event_connect_peer(&p->upstream->peer);
+
+    if (rc == NGX_ERROR) {
+        ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        return;
+    }
+
+    if (rc == NGX_CONNECT_ERROR) {
+        ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_ERROR);
+        return;
+    }
+
+    p->upstream->peer.connection->data = p;
+    p->upstream->peer.connection->write->event_handler =
+                                           ngx_http_proxy_send_request_handler;
+    p->upstream->peer.connection->read->event_handler =
+                                   ngx_http_proxy_process_upstream_status_line;
+
+    r = p->request;
+    c = p->upstream->peer.connection;
+    c->pool = r->pool;
+    c->read->log = c->write->log = c->log = r->connection->log;
+
+    octx = p->upstream->output_chain_ctx;
+
+    if (p->upstream->peer.tries > 1 && p->request_sent) {
+        ngx_http_proxy_reinit_upstream(p);
+    }
+
+    /* init or reinit ngx_output_chain() context */
+
+    if (r->request_body_hunk) {
+        if (!(octx->free = ngx_alloc_chain_link(r->pool))) {
+            ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return;
+        }
+
+        octx->free->hunk = r->request_body_hunk;
+        octx->free->next = NULL;
+        octx->hunks = 1;
+
+        r->request_body_hunk->pos = r->request_body_hunk->start;
+        r->request_body_hunk->last = r->request_body_hunk->start;
+    }
+
+    p->request_sent = 0;
+
+    if (rc == NGX_AGAIN) {
+        ngx_add_timer(c->write, p->lcf->connect_timeout);
+        return;
+    }
+
+    /* rc == NGX_OK */
+
+#if 1 /* test only */
+
+    if (c->read->ready) {
+        /* post aio operation */
+        ngx_http_proxy_process_upstream_status_line(c->read);
+        return;
+    }
+#endif
+
+    ngx_http_proxy_send_request(p);
+}
+
+
+static void ngx_http_proxy_send_request(ngx_http_proxy_ctx_t *p)
+{
+    int                      rc;
+    ngx_connection_t        *c;
+    ngx_chain_writer_ctx_t  *wctx;
+
+    c = p->upstream->peer.connection;
+
+#if (HAVE_KQUEUE)
+
+    if ((ngx_event_flags & NGX_HAVE_KQUEUE_EVENT)
+        && !p->request_sent
+        && c->write->kq_eof)
+    {
+        ngx_log_error(NGX_LOG_ERR, c->log, c->write->kq_errno,
+                      "connect() failed");
+
+        ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_ERROR);
+        return;
+    }
+
+#endif
+
+    p->action = "sending request to upstream";
+
+    wctx = p->upstream->output_chain_ctx->output_ctx;
+    wctx->out = NULL;
+    wctx->last = &wctx->out;
+    wctx->connection = c;
+
+    rc = ngx_output_chain(p->upstream->output_chain_ctx,
+                          p->request_sent ? NULL : p->request->request_hunks);
+
+    if (rc == NGX_ERROR) {
+        ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_ERROR);
+        return;
+    }
+
+    p->request_sent = 1;
+
+    if (c->write->timer_set) {
+        ngx_del_timer(c->write);
+    }
+
+    if (rc == NGX_AGAIN) {
+        ngx_add_timer(c->write, p->lcf->send_timeout);
+
+        if (ngx_handle_write_event(c->write, /* STUB: lowat */ 0) == NGX_ERROR)
+        {
+            ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return;
+        }
+
+        return;
+    }
+
+    /* rc == NGX_OK */
+
+    if (c->tcp_nopush) {
+        if (ngx_tcp_push(c->fd) == NGX_ERROR) {
+            ngx_log_error(NGX_LOG_CRIT, c->log,
+                          ngx_socket_errno,
+                          ngx_tcp_push_n " failed");
+            ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return; 
+        }
+
+        c->tcp_nopush = 0;
+        return;
+    }
+
+#if 0
+    if (c->read->ready) {
+
+        /* post aio operation */
+
+        /*
+         * although we can post aio operation just in the end
+         * of ngx_http_proxy_connect() CHECK IT !!!
+         * it's better to do here because we postpone header buffer allocation
+         */
+
+        ngx_http_proxy_process_upstream_status_line(c->read);
+        return;
+    }
+#endif
+
+    p->upstream->peer.connection->write->event_handler =
+                                                  ngx_http_proxy_dummy_handler;
+
+    if (ngx_handle_level_write_event(c->write) == NGX_ERROR) {
+        ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        return;
+    }
+}
+
+
+static void ngx_http_proxy_send_request_handler(ngx_event_t *wev)
+{
+    ngx_connection_t      *c;
+    ngx_http_proxy_ctx_t  *p;
+
+    c = wev->data;
+    p = c->data;
+
+    if (wev->timedout) {
+        p->action = "sending request to upstream";
+        ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_TIMEOUT);
+        return;
+    }
+
+    ngx_http_proxy_send_request(p);
+}
+
+
+static void ngx_http_proxy_dummy_handler(ngx_event_t *wev)
+{
+    ngx_log_debug(wev->log, "dummy handler");
+}
+
+
+static void ngx_http_proxy_process_upstream_status_line(ngx_event_t *rev)
+{
+    int                    rc;
+    ssize_t                n;
+    ngx_connection_t      *c;
+    ngx_http_proxy_ctx_t  *p;
+
+    c = rev->data;
+    p = c->data;
+    p->action = "reading upstream status line";
+
+    ngx_log_debug(rev->log, "http proxy process status line");
+
+    if (rev->timedout) {
+        ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_TIMEOUT);
+        return;
+    }
+
+    if (p->header_in == NULL) {
+        p->header_in = ngx_create_temp_hunk(p->request->pool,
+                                            p->lcf->header_buffer_size);
+        if (p->header_in == NULL) {
+            ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return;
+        }
+        p->header_in->tag = (ngx_hunk_tag_t) &ngx_http_proxy_module;
+
+        if (p->cache) {
+            p->header_in->pos += p->cache->ctx.header_size;
+            p->header_in->last = p->header_in->pos;
+        }
+    }
+
+    n = ngx_http_proxy_read_upstream_header(p);
+
+    if (n == NGX_AGAIN) {
+        return;
+    }
+
+    if (n == 0) {
+        ngx_log_error(NGX_LOG_ERR, rev->log, 0,
+                      "upstream prematurely closed connection");
+    }
+
+    if (n == NGX_ERROR || n == 0) {
+        ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_ERROR);
+        return;
+    }
+
+    p->upstream->peer.cached = 0;
+
+    rc = ngx_http_proxy_parse_status_line(p);
+
+    if (rc == NGX_AGAIN) {
+        if (p->header_in->pos == p->header_in->last) {
+            ngx_log_error(NGX_LOG_ERR, rev->log, 0,
+                          "upstream sent too long status line");
+            ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_INVALID_HEADER);
+        }
+        return;
+    }
+
+    if (rc == NGX_HTTP_PROXY_PARSE_NO_HEADER) {
+        ngx_log_error(NGX_LOG_ERR, rev->log, 0,
+                      "upstream sent no valid HTTP/1.0 header");
+
+        if (p->accel) {
+            ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_INVALID_HEADER);
+
+        } else {
+            p->request->http_version = NGX_HTTP_VERSION_9;
+            p->upstream->status = NGX_HTTP_OK;
+            ngx_http_proxy_send_response(p);
+        }
+
+        return;
+    }
+
+    /* rc == NGX_OK */
+
+    p->upstream->status = p->status;
+
+    if (p->status == NGX_HTTP_INTERNAL_SERVER_ERROR) {
+
+        if (p->upstream->peer.tries > 1
+            && (p->lcf->next_upstream & NGX_HTTP_PROXY_FT_HTTP_500))
+        {
+            ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_HTTP_500);
+            return;
+        }
+
+        if (p->upstream->peer.tries == 0
+            && p->stale
+            && (p->lcf->use_stale & NGX_HTTP_PROXY_FT_HTTP_500))
+        {
+            ngx_http_proxy_finalize_request(p,
+                                       ngx_http_proxy_send_cached_response(p));
+
+            return;
+        }
+    }
+
+    p->upstream->status_line.len = p->status_end - p->status_start;
+    p->upstream->status_line.data = ngx_palloc(p->request->pool,
+                                              p->upstream->status_line.len + 1);
+    if (p->upstream->status_line.data == NULL) {
+        ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        return;
+    }
+    ngx_cpystrn(p->upstream->status_line.data, p->status_start,
+                p->upstream->status_line.len + 1);
+
+    ngx_log_debug(rev->log, "http proxy status %d '%s'" _
+                  p->upstream->status _ p->upstream->status_line.data);
+
+    if (p->upstream->headers_in.headers) {
+        p->upstream->headers_in.headers->nelts = 0;
+    } else {
+        p->upstream->headers_in.headers = ngx_create_table(p->request->pool,
+                                                           20);
+    }
+
+    c->read->event_handler = ngx_http_proxy_process_upstream_headers;
+    ngx_http_proxy_process_upstream_headers(rev);
+}
+
+
+static void ngx_http_proxy_process_upstream_headers(ngx_event_t *rev)
+{
+    int                    i, rc;
+    ssize_t                n;
+    ngx_table_elt_t       *h;
+    ngx_connection_t      *c;
+    ngx_http_request_t    *r;
+    ngx_http_proxy_ctx_t  *p;
+
+    c = rev->data;
+    p = c->data;
+    r = p->request;
+    p->action = "reading upstream headers";
+
+    ngx_log_debug(rev->log, "http proxy process header line");
+
+    if (rev->timedout) {
+        ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_TIMEOUT);
+        return;
+    }
+
+    rc = NGX_AGAIN;
+
+    for ( ;; ) {
+        if (rc == NGX_AGAIN) {
+            n = ngx_http_proxy_read_upstream_header(p);
+
+            if (n == 0) {
+                ngx_log_error(NGX_LOG_ERR, rev->log, 0,
+                              "upstream prematurely closed connection");
+            }
+
+            if (n == NGX_ERROR || n == 0) {
+                ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_ERROR);
+                return;
+            }
+
+            if (n == NGX_AGAIN) {
+                return;
+            }
+        }
+
+        rc = ngx_http_parse_header_line(p->request, p->header_in);
+
+        if (rc == NGX_OK) {
+
+            /* a header line has been parsed successfully */
+
+            h = ngx_http_add_header(&p->upstream->headers_in,
+                                    ngx_http_proxy_headers_in);
+            if (h == NULL) {
+                ngx_http_proxy_finalize_request(p,
+                                                NGX_HTTP_INTERNAL_SERVER_ERROR);
+                return;
+            }
+
+            h->key.len = r->header_name_end - r->header_name_start;
+            h->value.len = r->header_end - r->header_start;
+
+            h->key.data = ngx_palloc(p->request->pool,
+                                     h->key.len + 1 + h->value.len + 1);
+            if (h->key.data == NULL) {
+                ngx_http_proxy_finalize_request(p,
+                                                NGX_HTTP_INTERNAL_SERVER_ERROR);
+                return;
+            }
+
+            h->value.data = h->key.data + h->key.len + 1;
+            ngx_cpystrn(h->key.data, r->header_name_start, h->key.len + 1);
+            ngx_cpystrn(h->value.data, r->header_start, h->value.len + 1);
+
+            for (i = 0; ngx_http_proxy_headers_in[i].name.len != 0; i++) {
+                if (ngx_http_proxy_headers_in[i].name.len != h->key.len) {
+                    continue;
+                }
+
+                if (ngx_strcasecmp(ngx_http_proxy_headers_in[i].name.data,
+                                                           h->key.data) == 0)
+                {
+                    *((ngx_table_elt_t **) ((char *) &p->upstream->headers_in
+                                   + ngx_http_proxy_headers_in[i].offset)) = h;
+                    break;
+                }
+            }
+
+            ngx_log_debug(c->log, "HTTP proxy header: '%s: %s'" _
+                          h->key.data _ h->value.data);
+
+            continue;
+
+        } else if (rc == NGX_HTTP_PARSE_HEADER_DONE) {
+
+            /* a whole header has been parsed successfully */
+
+            ngx_log_debug(c->log, "HTTP header done");
+
+            ngx_http_proxy_process_upstream_header(p);
+            ngx_http_proxy_send_response(p);
+            return;
+
+        } else if (rc != NGX_AGAIN) {
+
+            /* there was error while a header line parsing */
+
+            ngx_log_error(NGX_LOG_ERR, rev->log, 0,
+                      upstream_header_errors[rc - NGX_HTTP_PARSE_HEADER_ERROR]);
+
+            ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_INVALID_HEADER);
+            return;
+        }
+
+        /* rc == NGX_AGAIN: a header line parsing is still not complete */
+
+        if (p->header_in->last == p->header_in->end) {
+            ngx_log_error(NGX_LOG_ERR, rev->log, 0,
+                          "upstream sent too big header");
+
+            ngx_http_proxy_next_upstream(p, NGX_HTTP_PROXY_FT_INVALID_HEADER);
+            return;
+        }
+    }
+}
+
+
+static void ngx_http_proxy_process_upstream_header(ngx_http_proxy_ctx_t *p)
+{
+    time_t  expires;
+
+    expires = ngx_http_parse_time(p->upstream->headers_in.expires->value.data,
+                                  p->upstream->headers_in.expires->value.len);
+
+    p->cache->ctx.header.expires = expires;
+}
+
+
+static ssize_t ngx_http_proxy_read_upstream_header(ngx_http_proxy_ctx_t *p)
+{
+    ssize_t       n;
+    ngx_event_t  *rev;
+
+    rev = p->upstream->peer.connection->read;
+
+    n = p->header_in->last - p->header_in->pos;
+
+    if (n > 0) {
+        return n;
+    }
+
+    n = ngx_recv(p->upstream->peer.connection, p->header_in->last,
+                 p->header_in->end - p->header_in->last);
+
+    if (n == NGX_AGAIN) {
+        ngx_add_timer(rev, p->lcf->read_timeout);
+
+        if (ngx_handle_read_event(rev, 0) == NGX_ERROR) {
+            ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return NGX_ERROR;
+        }
+
+        return NGX_AGAIN;
+    }
+
+    if (n == 0) {
+        ngx_log_error(NGX_LOG_ERR, rev->log, 0,
+                      "upstream closed prematurely connection");
+    }
+
+    if (n == 0 || n == NGX_ERROR) {
+        return NGX_ERROR;
+    }
+
+    p->header_in->last += n;
+
+    return n;
+}
+
+
+static void ngx_http_proxy_send_response(ngx_http_proxy_ctx_t *p)
+{
+    int                           rc, i;
+    ngx_table_elt_t              *ho, *h;
+    ngx_event_pipe_t             *ep;
+    ngx_http_request_t           *r;
+    ngx_http_cache_file_t        *header;
+    ngx_http_core_loc_conf_t     *clcf;
+
+    r = p->request;
+
+    r->headers_out.status = p->upstream->status;
+
+#if 0
+    r->headers_out.content_length_n = -1;
+    r->headers_out.content_length = NULL;
+#endif
+
+    /* copy an upstream header to r->headers_out */
+
+    if (ngx_http_proxy_copy_header(p, &p->upstream->headers_in) == NGX_ERROR) {
+        ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        return;
+    }
+
+    /* TODO: preallocate event_pipe hunks, look "Content-Length" */
+
+    rc = ngx_http_send_header(r);
+
+    p->header_sent = 1;
+
+    if (p->cache) {
+        header = (ngx_http_cache_file_t *) p->header_in->start;
+
+        /* STUB */
+        header->header.expires = 0;
+        header->header.last_modified = 0;
+
+        header->header.length = r->headers_out.content_length_n;
+        header->key_len = p->cache->ctx.key.len;
+        ngx_memcpy(&header->key, p->cache->ctx.key.data, header->key_len);
+        header->key[header->key_len] = LF;
+    }
+
+    ep = ngx_pcalloc(r->pool, sizeof(ngx_event_pipe_t));
+    if (ep == NULL) {
+        ngx_http_proxy_finalize_request(p, 0);
+        return;
+    }
+
+    p->upstream->event_pipe = ep;
+
+    ep->input_filter = ngx_event_pipe_copy_input_filter;
+    ep->output_filter = (ngx_event_pipe_output_filter_pt)
+                                                        ngx_http_output_filter;
+    ep->output_ctx = r;
+    ep->tag = (ngx_hunk_tag_t) &ngx_http_proxy_module;
+    ep->bufs = p->lcf->bufs;
+    ep->busy_size = p->lcf->busy_buffers_size;
+    ep->upstream = p->upstream->peer.connection;
+    ep->downstream = r->connection;
+    ep->pool = r->pool;
+    ep->log = r->connection->log;
+
+    if (!(ep->temp_file = ngx_pcalloc(r->pool, sizeof(ngx_temp_file_t)))) {
+        ngx_http_proxy_finalize_request(p, 0);
+        return;
+    }
+
+    ep->temp_file->file.fd = NGX_INVALID_FILE;
+    ep->temp_file->file.log = r->connection->log;
+    ep->temp_file->path = p->lcf->temp_path;
+    ep->temp_file->pool = r->pool;
+    ep->temp_file->warn = "an upstream response is buffered "
+                         "to a temporary file";
+
+    ep->max_temp_file_size = p->lcf->max_temp_file_size;
+    ep->temp_file_write_size = p->lcf->temp_file_write_size;
+
+    ep->preread_hunks = ngx_alloc_chain_link(r->pool);
+    if (ep->preread_hunks == NULL) {
+        ngx_http_proxy_finalize_request(p, 0);
+        return;
+    }
+    ep->preread_hunks->hunk = p->header_in;
+    ep->preread_hunks->next = NULL;
+    p->header_in->type |= NGX_HUNK_PREREAD;
+
+    ep->preread_size = p->header_in->last - p->header_in->pos;
+
+    if (ngx_event_flags & NGX_USE_AIO_EVENT) {
+
+        /* the posted aio operation can currupt shadow buf */
+        ep->single_buf = 1;
+    }
+
+    /* TODO: ep->free_bufs = 0 if use ngx_create_chain_of_hunks() */
+    ep->free_bufs = 1;
+
+    /*
+     * event_pipe would do p->header_in->last += ep->preread_size
+     * as though these bytes were read.
+     */
+    p->header_in->last = p->header_in->pos;
+
+    ep->cachable = p->cachable;
+
+    if (p->lcf->cyclic_temp_file) {
+
+        /*
+         * we need to disable the use of sendfile() if we use cyclic temp file
+         * because the writing a new data can interfere with sendfile()
+         * that uses the same kernel file pages (at least on FreeBSD)
+         */
+
+        ep->cyclic_temp_file = 1;
+        r->sendfile = 0;
+
+    } else {
+        ep->cyclic_temp_file = 0;
+        r->sendfile = 1;
+    }
+
+    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
+
+    ep->read_timeout = p->lcf->read_timeout;
+    ep->send_timeout = clcf->send_timeout;
+    ep->send_lowat = clcf->send_lowat;
+
+    p->upstream->peer.connection->read->event_handler =
+                                                   ngx_http_proxy_process_body;
+    r->connection->write->event_handler = ngx_http_proxy_process_body;
+
+    ngx_http_proxy_process_body(p->upstream->peer.connection->read);
+
+    return;
+}
+
+
+static void ngx_http_proxy_process_body(ngx_event_t *ev)
+{
+    ngx_connection_t      *c;
+    ngx_http_request_t    *r;
+    ngx_http_proxy_ctx_t  *p;
+    ngx_event_pipe_t      *ep;
+
+    c = ev->data;
+
+    if (ev->write) {
+        ngx_log_debug(ev->log, "http proxy process downstream");
+        r = c->data;
+        p = ngx_http_get_module_ctx(r, ngx_http_proxy_module);
+        p->action = "sending to client";
+
+    } else {
+        ngx_log_debug(ev->log, "http proxy process upstream");
+        p = c->data;
+        r = p->request;
+        p->action = "reading upstream body";
+    }
+
+    ep = p->upstream->event_pipe;
+
+    if (ev->timedout) {
+        if (ev->write) {
+            ep->downstream_error = 1;
+            ngx_log_error(NGX_LOG_ERR, c->log, NGX_ETIMEDOUT,
+                          "client timed out");
+
+        } else {
+            ep->upstream_error = 1;
+            ngx_log_error(NGX_LOG_ERR, c->log, NGX_ETIMEDOUT,
+                          "upstream timed out");
+        }
+
+    } else {
+        if (ngx_event_pipe(ep, ev->write) == NGX_ABORT) {
+            ngx_http_proxy_finalize_request(p, 0);
+            return;
+        }
+    }
+
+    if (p->upstream->peer.connection) {
+        if (ep->upstream_done) {
+            if (ngx_http_proxy_update_cache(p) == NGX_ERROR) {
+                ngx_http_proxy_finalize_request(p, 0);
+                return;
+            }
+
+        } else if (ep->upstream_eof) {
+
+            /* TODO: check length & update cache */
+
+            if (ngx_http_proxy_update_cache(p) == NGX_ERROR) {
+                ngx_http_proxy_finalize_request(p, 0);
+                return;
+            }
+        }
+
+        if (ep->upstream_done || ep->upstream_eof || ep->upstream_error) {
+            ngx_http_proxy_close_connection(p->upstream->peer.connection);
+            p->upstream->peer.connection = NULL;
+        }
+    }
+
+    if (ep->downstream_done) {
+        ngx_log_debug(ev->log, "http proxy downstream done");
+        ngx_http_proxy_finalize_request(p, r->main ? 0 : ngx_http_send_last(r));
+        return;
+    }
+
+    if (ep->downstream_error) {
+        if (!p->cachable && p->upstream->peer.connection) {
+            ngx_http_proxy_close_connection(p->upstream->peer.connection);
+            p->upstream->peer.connection = NULL;
+        }
+ 
+        if (p->upstream->peer.connection == NULL) {
+            ngx_http_close_connection(c);
+        }
+    }
+
+    return;
+}
+
+
+static void ngx_http_proxy_next_upstream(ngx_http_proxy_ctx_t *p, int ft_type)
+{
+    int  status;
+
+ngx_log_debug(p->request->connection->log, "next upstream: %d" _ ft_type);
+
+    if (ft_type != NGX_HTTP_PROXY_FT_HTTP_404) {
+        ngx_event_connect_peer_failed(&p->upstream->peer);
+    }
+
+    if (ft_type == NGX_HTTP_PROXY_FT_TIMEOUT) {
+        ngx_log_error(NGX_LOG_ERR, p->request->connection->log, NGX_ETIMEDOUT,
+                      "upstream timed out");
+    }
+
+    if (p->upstream->peer.cached && ft_type == NGX_HTTP_PROXY_FT_ERROR) {
+        status = 0;
+
+    } else {
+        switch(ft_type) {
+        case NGX_HTTP_PROXY_FT_TIMEOUT:
+            status = NGX_HTTP_GATEWAY_TIME_OUT;
+            break;
+
+        case NGX_HTTP_PROXY_FT_HTTP_500:
+            status = NGX_HTTP_INTERNAL_SERVER_ERROR;
+            break;
+
+        case NGX_HTTP_PROXY_FT_HTTP_404:
+            status = NGX_HTTP_NOT_FOUND;
+            break;
+
+        /*
+         * NGX_HTTP_PROXY_FT_BUSY_LOCK and NGX_HTTP_PROXY_FT_MAX_WAITING
+         * never reach here
+         */
+
+        default:
+            status = NGX_HTTP_BAD_GATEWAY;
+        }
+    }
+
+    if (p->upstream->peer.connection) {
+        ngx_http_proxy_close_connection(p->upstream->peer.connection);
+        p->upstream->peer.connection = NULL;
+    }
+
+    if (status) {
+        if (ngx_http_proxy_log_state(p, status) == NGX_ERROR) {
+            ngx_http_proxy_finalize_request(p, NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return;
+        }
+
+        if (p->upstream->peer.tries == 0 || !(p->lcf->next_upstream & ft_type))
+        {
+            if (p->stale && (p->lcf->use_stale & ft_type)) {
+                ngx_http_proxy_finalize_request(p,
+                                       ngx_http_proxy_send_cached_response(p));
+                return;
+            }
+
+            ngx_http_proxy_finalize_request(p, status);
+            return;
+        }
+    }
+
+    ngx_http_proxy_connect(p);
+}