nginx-0.0.1-2003-04-08-19:40:10 import

1 files changed, 1387 insertions, 0 deletions

diff --git a/src/http/modules/proxy/ngx_http_event_proxy_handler.c b/src/http/modules/proxy/ngx_http_event_proxy_handler.c
new file mode 100644
index 000000000..1a6c9debb
--- /dev/null
+++ b/src/http/modules/proxy/ngx_http_event_proxy_handler.c
@@ -0,0 +1,1387 @@
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_string.h>
+#include <ngx_file.h>
+#include <ngx_hunk.h>
+#include <ngx_inet.h>
+#include <ngx_conf_file.h>
+#include <ngx_event_write.h>
+
+#include <ngx_http.h>
+#include <ngx_http_config.h>
+#include <ngx_http_core_module.h>
+#include <ngx_http_output_filter.h>
+#include <ngx_http_event_proxy_handler.h>
+
+
+static int ngx_http_proxy_handler(ngx_http_request_t *r);
+
+static ngx_chain_t *ngx_http_proxy_create_request(ngx_http_proxy_ctx_t *p);
+static int ngx_http_proxy_process_upstream(ngx_http_proxy_ctx_t *p,
+                                           ngx_event_t *ev);
+static int ngx_http_proxy_connect(ngx_http_proxy_ctx_t *p);
+static int ngx_http_proxy_process_upstream_event(ngx_event_t *ev);
+static int ngx_http_proxy_send_request(ngx_http_proxy_ctx_t *p);
+static int ngx_http_proxy_init_upstream(ngx_http_proxy_ctx_t *p);
+static int ngx_http_proxy_read_upstream_header(ngx_http_proxy_ctx_t *p);
+static int ngx_http_proxy_process_upstream_status_line(ngx_http_proxy_ctx_t *p);
+
+
+static int ngx_http_proxy_read_response_body(ngx_event_t *ev);
+static int ngx_http_proxy_write_to_client(ngx_event_t *ev);
+
+static int ngx_read_http_proxy_status_line(ngx_http_proxy_ctx_t *ctx);
+
+static int ngx_http_proxy_finalize_request(ngx_http_proxy_ctx_t *p, int error);
+static size_t ngx_http_proxy_log_error(void *data, char *buf, size_t len);
+
+static void *ngx_http_proxy_create_loc_conf(ngx_pool_t *pool);
+
+static char *ngx_http_proxy_set_pass(ngx_conf_t *cf, ngx_command_t *cmd,
+                                     char *conf);
+
+static char *ngx_http_proxy_parse_upstream(ngx_str_t *url,
+                                           ngx_http_proxy_upstream_url_t *uu);
+
+
+static ngx_command_t  ngx_http_proxy_commands[] = {
+
+    {ngx_string("proxy_pass"),
+     NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+     ngx_http_proxy_set_pass,
+     NGX_HTTP_LOC_CONF_OFFSET,
+     0},
+
+    {ngx_string("proxy_large_header"),
+     NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+     ngx_conf_set_flag_slot,
+     NGX_HTTP_LOC_CONF_OFFSET,
+     offsetof(ngx_http_proxy_loc_conf_t, large_header)},
+
+    {ngx_null_string, 0, NULL, 0, 0}
+};
+
+
+static ngx_http_module_t  ngx_http_proxy_module_ctx = {
+    NGX_HTTP_MODULE,
+
+    NULL,                                  /* create server config */
+    NULL,                                  /* init server config */
+
+    ngx_http_proxy_create_loc_conf,        /* create location config */
+    NULL                                   /* merge location config */
+};
+
+
+ngx_module_t  ngx_http_proxy_module = {
+    0,                                     /* module index */
+    &ngx_http_proxy_module_ctx,            /* module context */
+    ngx_http_proxy_commands,               /* module directives */
+    NGX_HTTP_MODULE_TYPE,                  /* module type */
+    NULL                                   /* init module */
+};
+
+
+static ngx_str_t http_methods[] = {
+    ngx_string("GET "),
+    ngx_string("HEAD "),
+    ngx_string("POST ")
+};
+
+
+static char http_version[] = " HTTP/1.0" CRLF;
+static char host_header[] = "Host: ";
+static char conn_close_header[] = "Connection: close" CRLF;
+
+
+/* AF_INET only */
+
+
+static int ngx_http_proxy_handler(ngx_http_request_t *r)
+{
+    int                         rc;
+    struct sockaddr_in          addr;
+    ngx_chain_t                *chain;
+    ngx_http_proxy_ctx_t       *p;
+    ngx_http_log_ctx_t         *hcx;
+    ngx_http_proxy_log_ctx_t   *lcx;
+    ngx_http_proxy_loc_conf_t  *lcf;
+
+    p = (ngx_http_proxy_ctx_t *)
+                         ngx_http_get_module_ctx(r, ngx_http_proxy_module_ctx);
+
+    if (p == NULL) {
+        ngx_http_create_ctx(r, p, ngx_http_proxy_module_ctx,
+                            sizeof(ngx_http_proxy_ctx_t),
+                            NGX_HTTP_INTERNAL_SERVER_ERROR);
+    }
+
+    if (p->upstream_url == NULL) {
+        lcf = (ngx_http_proxy_loc_conf_t *)
+                    ngx_http_get_module_loc_conf(r, ngx_http_proxy_module_ctx);
+
+        p->lcf = lcf;
+        p->request = r;
+        p->upstream_url = lcf->upstream_url;
+        p->upstreams = lcf->upstreams;
+        p->tries = lcf->upstreams->number;
+    }
+
+    ngx_test_null(p->log, ngx_palloc(r->pool, sizeof(ngx_log_t)),
+                  NGX_HTTP_INTERNAL_SERVER_ERROR);
+    ngx_memcpy(p->log, r->connection->log, sizeof(ngx_log_t));
+    ngx_test_null(lcx, ngx_pcalloc(r->pool, sizeof(ngx_http_proxy_log_ctx_t)),
+                  NGX_HTTP_INTERNAL_SERVER_ERROR);
+
+    p->log->data = lcx;
+    hcx = r->connection->log->data;
+    lcx->client = hcx->client;
+    lcx->url = hcx->url;
+
+    p->method = r->method;
+
+    /* TODO: read a client's body */
+
+    chain = ngx_http_proxy_create_request(p);
+    if (chain == NULL) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    /* TODO: duplicate the hunks and chain if there is backend farm */
+    p->out = chain;
+
+    p->last_error = NGX_HTTP_BAD_GATEWAY;
+    ngx_http_proxy_process_upstream(p, NULL);
+
+    /* On an error ngx_http_proxy_process_upstream() calls
+       ngx_http_proxy_finalize_request() so we return NGX_DONE to avoid
+       the additional NGX_HTTP_INTERNAL_SERVER_ERROR error
+       that would be generated by ngx_http_process_request() */
+
+    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          *hunk;
+    ngx_chain_t         *chain;
+    ngx_table_elt_t     *header;
+    ngx_http_request_t  *r;
+
+    r = p->request;
+
+    len = http_methods[p->method - 1].len
+          + p->upstream_url->uri.len
+          + (r->uri.len - p->upstream_url->location->len)
+          + r->args.len + 1   /* 1 is for "?" */
+          + sizeof(http_version) - 1
+          + sizeof(host_header) - 1 + p->upstream_url->host.len + 2
+          + sizeof(conn_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(hunk, ngx_create_temp_hunk(r->pool, len, 0, 0), NULL);
+    ngx_add_hunk_to_chain(chain, hunk, r->pool, NULL);
+
+    /* the request line */
+
+    ngx_memcpy(hunk->last, http_methods[p->method - 1].data,
+               http_methods[p->method - 1].len);
+    hunk->last += http_methods[p->method - 1].len;
+
+    ngx_memcpy(hunk->last, p->upstream_url->uri.data, p->upstream_url->uri.len);
+    hunk->last += p->upstream_url->uri.len;
+
+    ngx_memcpy(hunk->last, r->uri.data + p->upstream_url->location->len,
+               r->uri.len - p->upstream_url->location->len);
+    hunk->last += r->uri.len - p->upstream_url->location->len;
+
+    if (r->args.len > 0) {
+        *(hunk->last++) = '?';
+        ngx_memcpy(hunk->last, r->args.data, r->args.len);
+        hunk->last += r->args.len;
+    }
+
+    ngx_memcpy(hunk->last, http_version, sizeof(http_version) - 1);
+    hunk->last += sizeof(http_version) - 1;
+
+    /* the "Host" header */
+
+    ngx_memcpy(hunk->last, host_header, sizeof(host_header) - 1);
+    hunk->last += sizeof(host_header) - 1;
+
+    ngx_memcpy(hunk->last, p->upstream_url->host.data,
+               p->upstream_url->host.len);
+    hunk->last += p->upstream_url->host.len;
+
+    *(hunk->last++) = CR; *(hunk->last++) = LF;
+
+    /* the "Connection: close" header */
+
+    ngx_memcpy(hunk->last, conn_close_header, sizeof(conn_close_header) - 1);
+    hunk->last += sizeof(conn_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;
+        }
+
+        ngx_memcpy(hunk->last, header[i].key.data, header[i].key.len);
+        hunk->last += header[i].key.len;
+
+        *(hunk->last++) = ':'; *(hunk->last++) = ' ';
+
+        ngx_memcpy(hunk->last, header[i].value.data, header[i].value.len);
+        hunk->last += header[i].value.len;
+
+        *(hunk->last++) = CR; *(hunk->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 */
+    *(hunk->last++) = CR; *(hunk->last++) = LF;
+
+    /* STUB */ *(hunk->last++) = '\0';
+    ngx_log_debug(r->connection->log, "PROXY:\n'%s'" _ hunk->pos);
+
+    return chain;
+}
+
+
+static int ngx_http_proxy_process_upstream(ngx_http_proxy_ctx_t *p,
+                                           ngx_event_t *ev)
+{
+    int                         rc;
+    time_t                      now;
+    ngx_connection_t           *c;
+    ngx_http_proxy_upstream_t  *u;
+
+    for ( ;; ) {
+
+        if (ev == NULL) {
+            /* STUB: look up cached connection */
+            c  = NULL;
+
+            if (c) {
+                p->cached_connection = 1;
+                p->connection = c;
+                c->write->event_handler = ngx_http_proxy_process_upstream_event;
+                rc = ngx_http_proxy_send_request(p);
+
+            } else {
+                p->cached_connection = 0;
+                p->connection = NULL;
+                rc = ngx_http_proxy_connect(p);
+            }
+
+            if (p->connection) {
+                ev = p->connection->write;
+            }
+
+        } else {
+
+            if (ev->timedout) {
+                rc = NGX_HTTP_GATEWAY_TIME_OUT;
+
+            } else if (ev->write) {
+
+                rc = p->state_write_upstream_handler(p);
+
+            } else { /* ev->read */
+
+                rc = p->state_read_upstream_handler(p);
+            }
+        }
+
+        if (rc == NGX_DONE || rc == NGX_AGAIN) {
+            return rc;
+        }
+
+        if (rc == NGX_ERROR) {
+            return ngx_http_proxy_finalize_request(p,
+                                               NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return NGX_DONE;
+        }
+
+        if (rc == NGX_HTTP_BAD_GATEWAY || rc == NGX_HTTP_GATEWAY_TIME_OUT
+            || (rc == NGX_OK
+                && p->status == NGX_HTTP_INTERNAL_SERVER_ERROR
+                && p->lcf->retry_500_error))
+        {
+            if (ev) {
+                ngx_event_close_connection(ev);
+                ev = NULL;
+            }
+
+            if (!p->cached_connection) {
+                if (p->upstreams->number > 1) {
+                    now = ngx_time();
+                    u = &p->upstreams->u[p->cur_upstream];
+
+                    /* Here is the race condition when the upstreams are shared
+                       between threads or processes but it's not serious */
+
+                    u->fails++;
+                    u->accessed = now;
+
+                    /* */
+                }
+
+                p->tries--;
+                p->last_error = rc;
+            }
+
+            if (p->tries == 0) {
+                ngx_http_proxy_finalize_request(p, p->last_error);
+                return NGX_ERROR;
+            }
+        }
+
+        if (rc == NGX_OK) {
+            ngx_http_proxy_finalize_request(p, p->status);
+            return NGX_DONE;
+        }
+
+        if (rc > NGX_OK) {
+            ngx_http_proxy_finalize_request(p, rc);
+        }
+
+        return NGX_DONE;
+    }
+}
+
+
+static int ngx_http_proxy_connect(ngx_http_proxy_ctx_t *p)
+{
+    int                         rc, event;
+    struct sockaddr_in         *addr;
+    ngx_err_t                   err;
+    ngx_socket_t                s;
+    ngx_event_t                *rev, *wev;
+    ngx_connection_t           *c;
+    ngx_http_proxy_log_ctx_t   *lcx;
+    ngx_http_proxy_upstream_t  *u;
+
+    if (p->upstreams->number > 1) {
+        if (p->tries == p->upstreams->number) {
+
+            /* Here is the race condition
+               when the upstreams are shared between threads or processes
+               but it should not be serious */
+
+            p->cur_upstream = p->upstreams->current++;
+
+            if (p->upstreams->current >= p->upstreams->number) {
+                p->upstreams->current = 0;
+            }
+
+            /* */
+
+#if (NGX_MULTITHREADED || NGX_MULTIPROCESSED)
+            /* eliminate the sequences of the race condition */
+            if (p->cur_upstream >= p->upstreams->number) {
+                p->cur_upstream = 0;
+            }
+#endif
+        }
+
+        if (p->upstreams->max_fails > 0) {
+
+            for ( ;; ) {
+                u = &p->upstreams->u[p->cur_upstream];
+
+                /* Here is the race condition
+                   when the upstreams are shared between threads or processes
+                   but it should not be serious */
+
+                if (u->fails > p->upstreams->max_fails
+                    || u->accessed < p->upstreams->fail_timeout)
+                {
+                    break;
+                }
+
+                /* */
+
+                p->cur_upstream++;
+
+                if (p->cur_upstream >= p->upstreams->number) {
+                    p->cur_upstream = 0;
+                }
+
+                p->tries--;
+
+                if (p->tries == 0) {
+                    return p->last_error;
+                }
+            }
+        }
+    }
+
+    lcx = p->log->data;
+    lcx->action = "connecting to an upstream";
+    lcx->upstream = p->upstreams->u[p->cur_upstream].addr_port_name.data;
+    p->log->handler = ngx_http_proxy_log_error;
+
+    s = ngx_socket(AF_INET, SOCK_STREAM, IPPROTO_IP, 0);
+
+    if (s == -1) {
+        ngx_log_error(NGX_LOG_ALERT, p->log, ngx_socket_errno,
+                      ngx_socket_n " failed");
+        return NGX_ERROR;
+    }
+
+    if (p->lcf->rcvbuf) {
+        if (setsockopt(s, SOL_SOCKET, SO_RCVBUF,
+                       (const void *) &p->lcf->rcvbuf, sizeof(int)) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, p->log, ngx_socket_errno,
+                          "setsockopt(SO_RCVBUF) failed");
+
+            if (ngx_close_socket(s) == -1) {
+                ngx_log_error(NGX_LOG_ALERT, p->log, ngx_socket_errno,
+                              ngx_close_socket_n " failed");
+            }
+
+            return NGX_ERROR;
+        }
+    }
+
+    if (ngx_nonblocking(s) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, p->log, ngx_socket_errno,
+                      ngx_nonblocking_n " failed");
+
+        if (ngx_close_socket(s) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, p->log, ngx_socket_errno,
+                          ngx_close_socket_n " failed");
+        }
+
+        return NGX_ERROR;
+    }
+
+    c = &ngx_connections[s];
+    rev = &ngx_read_events[s];
+    wev = &ngx_write_events[s];
+
+    ngx_memzero(c, sizeof(ngx_connection_t));
+    ngx_memzero(rev, sizeof(ngx_event_t));
+    ngx_memzero(wev, sizeof(ngx_event_t));
+
+    rev->index = wev->index = NGX_INVALID_INDEX;
+    rev->data = wev->data = c;
+    c->read = rev;
+    c->write = wev;
+    rev->first = wev->first = 1;
+    rev->log = wev->log = c->log = p->log;
+    c->fd = s;
+    wev->close_handler = rev->close_handler = ngx_event_close_connection;
+
+#if !(USE_KQUEUE)
+
+#if (HAVE_EDGE_EVENT) /* epoll */
+
+    if (ngx_event_flags & NGX_HAVE_EDGE_EVENT) {
+        if (ngx_edge_add_event(wev) != NGX_OK) {
+            return NGX_ERROR;
+        }
+    }
+
+#endif
+
+#endif
+
+    ngx_test_null(c->pool, ngx_create_pool(p->lcf->conn_pool_size, p->log),
+                  NGX_ERROR);
+
+    ngx_test_null(p->sockaddr,
+                  ngx_pcalloc(c->pool, sizeof(struct sockaddr_in)),
+                  NGX_ERROR);
+
+    addr = (struct sockaddr_in *) p->sockaddr;
+
+    addr->sin_family = AF_INET;
+    addr->sin_addr.s_addr = p->upstreams->u[p->cur_upstream].addr;
+    addr->sin_port = htons(p->upstreams->u[p->cur_upstream].port);
+
+    rc = connect(s, p->sockaddr, sizeof(struct sockaddr_in));
+
+    if (rc == -1) {
+        err = ngx_socket_errno;
+        if (err != NGX_EINPROGRESS) {
+            ngx_log_error(NGX_LOG_CRIT, p->log, err, "connect() failed");
+
+            if (ngx_close_socket(s) == -1) {
+                ngx_log_error(NGX_LOG_ALERT, p->log, ngx_socket_errno,
+                              ngx_close_socket_n " failed");
+            }
+
+            ngx_destroy_pool(c->pool);
+
+            return NGX_HTTP_BAD_GATEWAY;
+        }
+    }
+
+    c->data = p->request;
+    p->connection = c;
+
+    ngx_test_null(c->pool, ngx_create_pool(p->lcf->conn_pool_size, p->log),
+                  NGX_ERROR);
+
+#if (USE_KQUEUE)
+
+    if (ngx_add_event(rev, NGX_READ_EVENT, NGX_CLEAR_EVENT) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+#else
+
+    if ((ngx_event_flags & NGX_HAVE_EDGE_EVENT) == 0) { /* not epoll */
+
+        if (ngx_event_flags & NGX_HAVE_CLEAR_EVENT) {  /* kqueue */
+            event = NGX_CLEAR_EVENT;
+
+        } else {                             /* select, poll, /dev/poll */
+            event = NGX_LEVEL_EVENT;
+        }
+
+        /* TODO: aio, iocp */
+
+        if (ngx_add_event(rev, NGX_READ_EVENT, event) != NGX_OK) {
+            return NGX_ERROR;
+        }
+    }
+
+#endif /* USE_KQUEUE */
+
+    wev->event_handler = rev->event_handler =
+                                         ngx_http_proxy_process_upstream_event;
+
+    p->state_write_upstream_handler = ngx_http_proxy_send_request;
+    p->state_read_upstream_handler = ngx_http_proxy_init_upstream;
+
+    /* The connection has been established */
+    if (rc == 0) {
+        wev->write = 1;
+        wev->ready = 1;
+
+        return ngx_http_proxy_send_request(p);
+    }
+
+    /* The connection is in a progress */
+
+    wev->timer_set = 1;
+    ngx_add_timer(wev, p->lcf->connect_timeout);
+
+#if (USE_KQUEUE)
+
+    if (ngx_add_event(wev, NGX_WRITE_EVENT, NGX_CLEAR_EVENT) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+#else
+
+    /* TODO: aio, iocp */
+
+    if (ngx_event_flags & NGX_HAVE_EDGE_EVENT) {
+        return NGX_DONE;
+    }
+
+    if (ngx_add_event(wev, NGX_WRITE_EVENT, event) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+#endif /* USE_KQUEUE */
+
+    return NGX_DONE;
+}
+
+
+static int ngx_http_proxy_process_upstream_event(ngx_event_t *ev)
+{
+    ngx_connection_t      *c;
+    ngx_http_request_t    *r;
+    ngx_http_proxy_ctx_t  *p;
+
+    c = (ngx_connection_t *) ev->data;
+    r = (ngx_http_request_t *) c->data;
+    p = (ngx_http_proxy_ctx_t *)
+                         ngx_http_get_module_ctx(r, ngx_http_proxy_module_ctx);
+
+    return ngx_http_proxy_process_upstream(p, ev);
+}
+
+
+static int ngx_http_proxy_send_request(ngx_http_proxy_ctx_t *p)
+{
+    ngx_chain_t  *chain;
+    ngx_event_t  *wev;
+
+    chain = ngx_write_chain(p->connection, p->out, 0);
+    if (chain == (ngx_chain_t *) -1) {
+        return NGX_ERROR;
+    }
+
+    p->out = chain;
+
+    wev = p->connection->write;
+
+    ngx_del_timer(wev);
+
+    if (chain) {
+        ngx_add_timer(wev, p->lcf->send_timeout);
+        wev->timer_set = 1;
+
+    } else {
+        wev->timer_set = 0;
+    }
+
+    return NGX_DONE;
+}
+
+
+static int ngx_http_proxy_init_upstream(ngx_http_proxy_ctx_t *p)
+{
+    int                   n;
+    ngx_hunk_t          **ph;
+    ngx_http_request_t   *r;
+
+    r = p->request;
+
+    ngx_test_null(p->header_in,
+                  ngx_create_temp_hunk(r->pool, p->lcf->header_size, 0, 0),
+                  NGX_ERROR);
+
+    p->header_in->type = NGX_HUNK_MEMORY|NGX_HUNK_IN_MEMORY;
+
+    ngx_test_null(p->headers_in,
+                  ngx_palloc(r->pool, sizeof(ngx_http_proxy_headers_in_t)),
+                  NGX_ERROR);
+
+    p->hunks_number = p->lcf->max_block_size / p->lcf->block_size;
+    if (p->hunks_number * p->lcf->block_size < p->lcf->max_block_size) {
+        p->hunks_number++;
+    }
+
+    ngx_init_array(p->hunks, r->pool, p->hunks_number, sizeof(ngx_hunk_t *),
+                   NGX_ERROR);
+
+    ngx_test_null(ph, ngx_push_array(&p->hunks), NGX_ERROR);
+    *ph = p->header_in;
+
+    p->state_handler = ngx_http_proxy_process_upstream_status_line;
+
+    return ngx_http_proxy_read_upstream_header(p);
+}
+
+
+static int ngx_http_proxy_read_upstream_header(ngx_http_proxy_ctx_t *p)
+{
+    int           n, rc;
+    ngx_event_t  *rev;
+
+    rev = p->connection->read;
+
+    do {
+        n = ngx_event_recv(p->connection, p->header_in->last,
+                           p->header_in->end - p->header_in->last);
+
+        if (n == NGX_AGAIN) {
+            if (rev->timer_set) {
+                ngx_del_timer(rev);
+            } else {
+                rev->timer_set = 1;
+            }
+
+            ngx_add_timer(rev, p->lcf->read_timeout);
+            return NGX_AGAIN;
+        }
+
+        if (n == NGX_ERROR) {
+            return NGX_HTTP_BAD_GATEWAY;
+        }
+
+        ngx_log_debug(p->log, "http proxy read %d" _ n);
+
+        if (n == 0) {
+            ngx_log_error(NGX_LOG_INFO, p->log, 0,
+                          "upstream closed prematurely connection");
+            return NGX_HTTP_BAD_GATEWAY;
+        }
+
+        p->header_in->last += n;
+
+        /* the state handlers are called in the following order:
+            ngx_http_proxy_process_upstream_status_line(r)
+            ngx_http_proxy_process_upstream_headers(r) */
+
+        do {
+            rc = p->state_handler(p);
+        } while (rc == NGX_AGAIN && p->header_in->end < p->header_in->last);
+
+    } while (rc == NGX_AGAIN
+             && (rev->ready || ngx_event_flags & NGX_HAVE_AIO_EVENT));
+
+    if (rc > NGX_OK) {
+        return rc;
+    }
+
+    if (rc == NGX_OK) {
+        /* STUB */ return NGX_ERROR;
+    }
+
+    /* STUB */ return NGX_ERROR;
+}
+
+
+static int ngx_http_proxy_process_upstream_status_line(ngx_http_proxy_ctx_t *p)
+{
+    int  rc;
+
+#if 0
+    *p->header_in->last = '\0';
+    ngx_log_debug(p->log, "PROXY:\n'%s'" _ p->header_in->pos);
+#endif
+
+    rc = ngx_read_http_proxy_status_line(p);
+
+    if (rc == NGX_HTTP_PROXY_PARSE_NO_HEADER) {
+        p->status = 200;
+        p->status_line.len = 0;
+        p->full_status_line.len = 0;
+    }
+
+    if (rc == NGX_OK) {
+        p->status_line.len = p->status_end - p->status_start;
+        p->full_status_line.len = p->status_end - p->header_in->start;
+
+        if (p->lcf->large_header) {
+            ngx_test_null(p->full_status_line.data,
+                          ngx_palloc(p->request->pool,
+                                     p->full_status_line.len + 1),
+                          NGX_HTTP_INTERNAL_SERVER_ERROR);
+
+            ngx_cpystrn(p->full_status_line.data, p->header_in->start,
+                        p->full_status_line.len + 1);
+
+            if (p->header_in->pos == p->header_in->end) {
+                p->header_in->pos = p->header_in->last = p->header_in->start;
+            }
+
+        } else {
+            p->status_line.data = p->status_start;
+            p->full_status_line.data = p->header_in->start;
+            *p->status_end = '\0';
+        }
+
+        ngx_log_debug(p->log, "upstream status: %d, '%s'" _
+                      p->status _ p->full_status_line.data);
+
+        p->state_handler = NULL;
+    }
+
+    if (p->header_in->last == p->header_in->end) {
+        rc = NGX_HTTP_PARSE_TOO_LONG_STATUS_LINE;
+
+    } else if (rc == NGX_AGAIN) {
+        return NGX_AGAIN;
+    }
+
+    /* STUB */ return NGX_ERROR;
+}
+
+
+
+
+
+
+
+
+
+
+#if 0
+static int ngx_http_proxy_process_response_header(ngx_http_request_t *r,
+                                                  ngx_http_proxy_ctx_t *p)
+{
+    return NGX_OK;
+}
+#endif
+
+
+static int ngx_http_proxy_read_response_body(ngx_event_t *ev)
+{
+    int                    n;
+    char                  *buf;
+    size_t                 left, size;
+    ngx_hunk_t            *h, **ph;
+    ngx_connection_t      *c;
+    ngx_http_request_t    *r;
+    ngx_http_proxy_ctx_t  *p;
+
+    if (ev->timedout) {
+        return NGX_ERROR;
+    }
+
+    c = (ngx_connection_t *) ev->data;
+    r = (ngx_http_request_t *) c->data;
+    p = (ngx_http_proxy_ctx_t *)
+                         ngx_http_get_module_ctx(r, ngx_http_proxy_module_ctx);
+
+    if (p->hunks.nelts > 0) {
+        h = ((ngx_hunk_t **) p->hunks.elts)[p->hunks.nelts - 1];
+        left = h->end - h->last;
+
+    } else {
+        h = NULL;
+        left = 0;
+    }
+
+    do {
+
+#if (USE_KQUEUE)
+
+        /* do not allocate new block if there is EOF */
+        if (ev->eof && ev->available == 0) {
+            left = 1;
+        }
+
+#elif (HAVE_KQUEUE)
+
+        if (ngx_event_type == NGX_HAVE_KQUEUE_EVENT) {
+            /* do not allocate new block if there is EOF */
+            if (ev->eof && ev->available == 0) {
+                left = 1;
+            }
+        }
+
+#endif
+
+        if (left == 0) {
+            ngx_test_null(ph, ngx_push_array(&p->hunks), NGX_ERROR);
+            ngx_test_null(h,
+                          ngx_create_temp_hunk(r->pool,
+                                               /* STUB */ 4096 /**/, 0, 0),
+                          NGX_ERROR);
+
+            h->type = NGX_HUNK_MEMORY|NGX_HUNK_IN_MEMORY;
+            *ph = h;
+        }
+
+        if (h != NULL) {
+            buf = h->last;
+            size = h->end - h->last;
+
+        } else {
+            buf = (char *) &buf;
+            size = 0;
+        }
+
+        n = ngx_event_recv(c, buf, size);
+
+        ngx_log_debug(c->log, "READ:%d" _ n);
+
+        if (n == NGX_AGAIN) {
+            return NGX_DONE;
+        }
+
+        if (n == NGX_ERROR) {
+            return NGX_ERROR;
+        }
+
+        h->last += n;
+        left = h->end - h->last;
+
+        /* STUB */
+        *h->last = '\0';
+        ngx_log_debug(c->log, "PROXY:\n'%s'" _ h->pos);
+        /**/
+
+    } while (n > 0 && left == 0);
+
+    if (n == 0) {
+        ngx_log_debug(c->log, "CLOSE proxy");
+#if 0
+        ngx_del_event(ev, NGX_READ_EVENT, NGX_CLOSE_EVENT);
+#endif
+        ngx_event_close_connection(ev);
+
+        p->hunk_n = 0;
+        c->write->event_handler = ngx_http_proxy_write_to_client;
+        return ngx_http_proxy_write_to_client(c->write);
+    }
+
+    /* STUB */ return NGX_DONE;
+}
+
+
+static int ngx_http_proxy_write_to_client(ngx_event_t *ev)
+{
+    int  rc;
+    ngx_hunk_t            *h;
+    ngx_connection_t      *c;
+    ngx_http_request_t    *r;
+    ngx_http_proxy_ctx_t  *p;
+
+    c = (ngx_connection_t *) ev->data;
+    r = (ngx_http_request_t *) c->data;
+    p = (ngx_http_proxy_ctx_t *)
+                         ngx_http_get_module_ctx(r, ngx_http_proxy_module_ctx);
+
+    do {
+        h = ((ngx_hunk_t **) p->hunks.elts)[p->hunk_n];
+
+        rc = ngx_http_output_filter(r, h);
+        if (rc != NGX_OK) {
+            return rc;
+        }
+
+        if (p->hunk_n >= p->hunks.nelts) {
+            break;
+        }
+
+        p->hunk_n++;
+
+    } while (rc == NGX_OK);
+
+    return NGX_OK;
+}
+
+
+static int ngx_http_proxy_finalize_request(ngx_http_proxy_ctx_t *p, int error)
+{
+    return ngx_http_finalize_request(p->request, error);
+}
+
+
+static int ngx_http_proxy_error(ngx_http_request_t *r, ngx_http_proxy_ctx_t *p,
+                                int error)
+{
+    ngx_event_close_connection(p->connection->read);
+
+    return ngx_http_error(r, error);
+} 
+
+
+static size_t ngx_http_proxy_log_error(void *data, char *buf, size_t len)
+{
+    ngx_http_proxy_log_ctx_t *lcx = (ngx_http_proxy_log_ctx_t *) data;
+
+    return ngx_snprintf(buf, len,
+                        " while %s, upstream: %s, client: %s, URL: %s",
+                        lcx->action, lcx->upstream, lcx->client, lcx->url);
+}
+
+
+
+static int ngx_read_http_proxy_status_line(ngx_http_proxy_ctx_t *ctx)
+{
+    char   ch;
+    char  *p;
+    enum  {
+        sw_start = 0,
+        sw_first_major_digit,
+        sw_major_digit,
+        sw_first_minor_digit,
+        sw_minor_digit,
+        sw_status,
+        sw_space_after_status,
+        sw_status_text,
+        sw_almost_done,
+        sw_done
+    } state;
+
+    state = ctx->state;
+    p = ctx->header_in->pos;
+
+    while (p < ctx->header_in->last && state < sw_done) {
+        ch = *p++;
+
+        switch (state) {
+
+        /* "HTTP/" */
+        case sw_start:
+            if (p + 3 >= ctx->header_in->last) {
+                return NGX_AGAIN;
+            }
+
+            if (ch != 'H' || *p != 'T' || *(p + 1) != 'T' || *(p + 2) != 'P'
+                          || *(p + 3) != '/')
+            {
+                return NGX_HTTP_PROXY_PARSE_NO_HEADER;
+            }
+
+            p += 4;
+            state = sw_first_major_digit;
+            break;
+
+        /* first digit of major HTTP version */
+        case sw_first_major_digit:
+            if (ch < '1' || ch > '9') {
+                return NGX_HTTP_PROXY_PARSE_NO_HEADER;
+            }
+
+            state = sw_major_digit;
+            break;
+
+        /* major HTTP version or dot */
+        case sw_major_digit:
+            if (ch == '.') {
+                state = sw_first_minor_digit;
+                break;
+            }
+
+            if (ch < '0' || ch > '9') {
+                return NGX_HTTP_PROXY_PARSE_NO_HEADER;
+            }
+
+            break;
+
+        /* first digit of minor HTTP version */
+        case sw_first_minor_digit:
+            if (ch < '0' || ch > '9') {
+                return NGX_HTTP_PROXY_PARSE_NO_HEADER;
+            }
+
+            state = sw_minor_digit;
+            break;
+
+        /* minor HTTP version or end of request line */
+        case sw_minor_digit:
+            if (ch == ' ') {
+                state = sw_status;
+                break;
+            }
+
+            if (ch < '0' || ch > '9') {
+                return NGX_HTTP_PROXY_PARSE_NO_HEADER;
+            }
+
+            break;
+
+        /* HTTP status code */
+        case sw_status:
+            if (ch < '0' || ch > '9') {
+                return NGX_HTTP_PROXY_PARSE_NO_HEADER;
+            }
+
+            ctx->status = ctx->status * 10 + ch - '0';
+
+            if (++ctx->status_count == 3) {
+                state = sw_space_after_status;
+                ctx->status_start = p - 3;
+            }
+
+            break;
+
+         /* space or end of line */
+         case sw_space_after_status:
+            switch (ch) {
+            case ' ':
+                state = sw_status_text;
+                break;
+            case CR:
+                state = sw_almost_done;
+                break;
+            case LF:
+                state = sw_done;
+                break;
+            default:
+                return NGX_HTTP_PROXY_PARSE_NO_HEADER;
+            }
+            break;
+
+        /* any text until end of line */
+        case sw_status_text:
+            switch (ch) {
+            case CR:
+                state = sw_almost_done;
+                break;
+            case LF:
+                state = sw_done;
+                break;
+            }
+            break;
+
+        /* end of request line */
+        case sw_almost_done:
+            ctx->status_end = p - 2;
+            switch (ch) {
+            case LF:
+                state = sw_done;
+                break;
+            default:
+                return NGX_HTTP_PROXY_PARSE_NO_HEADER;
+            }
+            break;
+        }
+    }
+
+    ctx->header_in->pos = p;
+
+    if (state == sw_done) {
+        if (ctx->status_end == NULL) {
+            ctx->status_end = p - 1;
+        }
+
+        ctx->state = sw_start;
+        return NGX_OK;
+
+    } else {
+        ctx->state = state;
+        return NGX_AGAIN;
+    }
+}
+
+
+static void *ngx_http_proxy_create_loc_conf(ngx_pool_t *pool)
+{
+    ngx_http_proxy_loc_conf_t *conf;
+
+    ngx_test_null(conf,
+                  ngx_pcalloc(pool, sizeof(ngx_http_proxy_loc_conf_t)),
+                  NULL);
+
+    /* STUB */
+    conf->conn_pool_size = 16384;
+    conf->connect_timeout = 10000;
+    conf->send_timeout = 10000;
+    conf->read_timeout = 10000;
+    conf->header_size = 1024;
+    conf->block_size = 4096;
+    conf->max_block_size = 32768;
+    /**/
+
+    return conf;
+}
+
+
+static char *ngx_http_proxy_set_pass(ngx_conf_t *cf, ngx_command_t *cmd,
+                                     char *conf)
+{
+    ngx_http_proxy_loc_conf_t *lcf = (ngx_http_proxy_loc_conf_t *) conf;
+
+    int                        i, s, len;
+    char                      *err, *host;
+    struct hostent            *h;
+    u_int32_t                  addr;
+    ngx_str_t                 *value;
+    ngx_http_conf_ctx_t       *ctx;
+    ngx_http_core_loc_conf_t  *core_lcf;
+
+    value = (ngx_str_t *) cf->args->elts;
+
+    if (ngx_strncasecmp(value[1].data, "http://", 7) != 0) {
+        return "invalid URL prefix";
+    }
+
+    ngx_test_null(lcf->upstream_url,
+                  ngx_pcalloc(cf->pool, sizeof(ngx_http_proxy_upstream_url_t)),
+                  NGX_CONF_ERROR);
+
+    value[1].data += 7;
+    value[1].len -= 7;
+
+    err = ngx_http_proxy_parse_upstream(&value[1], lcf->upstream_url);
+
+    if (err) {
+        return err;
+    }
+
+    if (lcf->upstream_url->port == 0) {
+        lcf->upstream_url->port = 80;
+    }
+
+    ngx_test_null(host, ngx_palloc(cf->pool, lcf->upstream_url->host.len + 1),
+                  NGX_CONF_ERROR);
+    ngx_cpystrn(host, lcf->upstream_url->host.data,
+                lcf->upstream_url->host.len + 1);
+
+    /* TODO: look up upstreams */
+
+    addr = inet_addr(host);
+    if (addr == INADDR_NONE) {
+        h = gethostbyname(host);
+
+        if (h == NULL || h->h_addr_list[0] == NULL) {
+            /* STUB: "host %s not found", host */
+            return "host not found";
+        }
+
+        for (i = 0; h->h_addr_list[i] != NULL; i++) {
+            /* void */
+        }
+
+        /* MP: ngx_shared_palloc() */
+
+        ngx_test_null(lcf->upstreams,
+                      ngx_pcalloc(cf->pool,
+                                sizeof(ngx_http_proxy_upstreams_t)
+                                + sizeof(ngx_http_proxy_upstream_t) * (i - 1)),
+                      NGX_CONF_ERROR);
+
+        lcf->upstreams->number = i;
+
+        for (i = 0; h->h_addr_list[i] != NULL; i++) {
+            lcf->upstreams->u[i].host.data = host;
+            lcf->upstreams->u[i].host.len = lcf->upstream_url->host.len;
+            lcf->upstreams->u[i].addr = *(u_int32_t *)(h->h_addr_list[i]);
+            lcf->upstreams->u[i].port = lcf->upstream_url->port;
+
+            len = INET_ADDRSTRLEN + lcf->upstream_url->port_name.len + 1;
+            ngx_test_null(lcf->upstreams->u[i].addr_port_name.data,
+                          ngx_palloc(cf->pool, len),
+                          NGX_CONF_ERROR);
+
+            s = ngx_inet_ntop(AF_INET,
+                              (char *) &lcf->upstreams->u[i].addr,
+                              lcf->upstreams->u[i].addr_port_name.data,
+                              len);
+
+            lcf->upstreams->u[i].addr_port_name.data[s++] = ':';
+
+            ngx_cpystrn(lcf->upstreams->u[i].addr_port_name.data + s,
+                        lcf->upstream_url->port_name.data,
+                        lcf->upstream_url->port_name.len + 1);
+
+            lcf->upstreams->u[i].addr_port_name.len =
+                                      s + lcf->upstream_url->port_name.len + 1;
+        }
+
+    } else {
+
+        /* MP: ngx_shared_palloc() */
+
+        ngx_test_null(lcf->upstreams,
+                      ngx_palloc(cf->pool, sizeof(ngx_http_proxy_upstreams_t)),
+                      NGX_CONF_ERROR);
+
+        lcf->upstreams->number = 1;
+
+        lcf->upstreams->u[0].host.data = host;
+        lcf->upstreams->u[0].host.len = lcf->upstream_url->host.len;
+        lcf->upstreams->u[0].addr = addr;
+        lcf->upstreams->u[0].port = lcf->upstream_url->port;
+
+        len = lcf->upstream_url->host.len
+              + lcf->upstream_url->port_name.len + 1;
+
+        ngx_test_null(lcf->upstreams->u[0].addr_port_name.data,
+                      ngx_palloc(cf->pool, len + 1),
+                      NGX_CONF_ERROR);
+
+        ngx_memcpy(lcf->upstreams->u[0].addr_port_name.data,
+                   lcf->upstream_url->host.data,
+                   lcf->upstream_url->host.len);
+
+        s = lcf->upstream_url->host.len;
+
+        lcf->upstreams->u[0].addr_port_name.data[s++] = ':';
+
+        ngx_cpystrn(lcf->upstreams->u[0].addr_port_name.data + s,
+                    lcf->upstream_url->port_name.data,
+                    lcf->upstream_url->port_name.len + 1);
+
+        lcf->upstreams->u[0].addr_port_name.len = len;
+    }
+
+    ctx = cf->ctx;
+    core_lcf = ctx->loc_conf[ngx_http_core_module_ctx.index];
+    core_lcf->handler = ngx_http_proxy_handler;
+    lcf->upstream_url->location = &core_lcf->name;
+
+    return NULL;
+}
+
+
+static char *ngx_http_proxy_parse_upstream(ngx_str_t *url,
+                                           ngx_http_proxy_upstream_url_t *uu)
+{
+    size_t  i;
+
+    if (url->data[0] == ':' || url->data[0] == '/') {
+        return "invalid upstream URL";
+    }
+
+    uu->host.data = url->data;
+    uu->host_header.data = url->data;
+
+    for (i = 1; i < url->len; i++) {
+        if (url->data[i] == ':') {
+            uu->port_name.data = &url->data[i] + 1;
+            uu->host.len = i;
+        }
+
+        if (url->data[i] == '/') {
+            uu->uri.data = &url->data[i];
+            uu->uri.len = url->len - i;
+            uu->host_header.len = i;
+
+            if (uu->host.len == 0) {
+                uu->host.len = i;
+            }
+
+            if (uu->port_name.data == NULL) {
+                return NULL;
+            }
+
+            uu->port_name.len = &url->data[i] - uu->port_name.data;
+
+            if (uu->port_name.len > 0) {
+                uu->port = ngx_atoi(uu->port_name.data, uu->port_name.len);
+                if (uu->port > 0) {
+                    return NULL;
+                }
+            }
+
+            return "invalid port in upstream URL";
+        }
+    }
+
+    if (uu->host.len == 0) {
+        uu->host.len = i;
+    }
+
+    uu->host_header.len = i;
+
+    uu->uri.data = "/";
+    uu->uri.len = 1;
+
+    if (uu->port_name.data == NULL) {
+        return NULL;
+    }
+
+    uu->port_name.len = &url->data[i] - uu->port_name.data;
+
+    if (uu->port_name.len > 0) {
+        uu->port = ngx_atoi(uu->port_name.data, uu->port_name.len);
+        if (uu->port > 0) {
+            return NULL;
+        }
+    }
+
+    return "invalid port in upstream URL";
+}