src/http/ngx_http_request_body.c - net/nginx-mbedtls - Rivoreo Source Code Repositories


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


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


 static void ngx_http_read_client_request_body_handler(ngx_http_request_t *r);
 static ngx_int_t ngx_http_do_read_client_request_body(ngx_http_request_t *r);
 static ngx_int_t ngx_http_write_request_body(ngx_http_request_t *r);
 static ngx_int_t ngx_http_read_discarded_request_body(ngx_http_request_t *r);
 static ngx_int_t ngx_http_discard_request_body_filter(ngx_http_request_t *r,
     ngx_buf_t *b);
 static ngx_int_t ngx_http_test_expect(ngx_http_request_t *r);

 static ngx_int_t ngx_http_request_body_filter(ngx_http_request_t *r,
     ngx_chain_t *in);
 static ngx_int_t ngx_http_request_body_length_filter(ngx_http_request_t *r,
     ngx_chain_t *in);
 static ngx_int_t ngx_http_request_body_chunked_filter(ngx_http_request_t *r,
     ngx_chain_t *in);
 static ngx_int_t ngx_http_request_body_save_filter(ngx_http_request_t *r,
     ngx_chain_t *in);


 ngx_int_t
 ngx_http_read_client_request_body(ngx_http_request_t *r,
     ngx_http_client_body_handler_pt post_handler)
 {
     size_t                     preread;
     ssize_t                    size;
     ngx_int_t                  rc;
     ngx_buf_t                 *b;
     ngx_chain_t                out, *cl;
     ngx_http_request_body_t   *rb;
     ngx_http_core_loc_conf_t  *clcf;

     r->main->count++;

 #if (NGX_HTTP_SPDY)
     if (r->spdy_stream) {
         rc = ngx_http_spdy_read_request_body(r, post_handler);
         goto done;
     }
 #endif

     if (r != r->main || r->request_body || r->discard_body) {
         post_handler(r);
         return NGX_OK;
     }

     if (ngx_http_test_expect(r) != NGX_OK) {
         rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
         goto done;
     }

     rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t));
     if (rb == NULL) {
         rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
         goto done;
     }

     /*
      * set by ngx_pcalloc():
      *
      *     rb->bufs = NULL;
      *     rb->buf = NULL;
      *     rb->free = NULL;
      *     rb->busy = NULL;
      *     rb->chunked = NULL;
      */

     rb->rest = -1;
     rb->post_handler = post_handler;

     r->request_body = rb;

     if (r->headers_in.content_length_n < 0 && !r->headers_in.chunked) {
         post_handler(r);
         return NGX_OK;
     }

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

     if (preread) {

         /* there is the pre-read part of the request body */

         ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                        "http client request body preread %uz", preread);

         out.buf = r->header_in;
         out.next = NULL;

         rc = ngx_http_request_body_filter(r, &out);

         if (rc != NGX_OK) {
             goto done;
         }

         r->request_length += preread - (r->header_in->last - r->header_in->pos);

         if (!r->headers_in.chunked
             && rb->rest > 0
             && rb->rest <= (off_t) (r->header_in->end - r->header_in->last))
         {
             /* the whole request body may be placed in r->header_in */

             b = ngx_calloc_buf(r->pool);
             if (b == NULL) {
                 rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
                 goto done;
             }

             b->temporary = 1;
             b->start = r->header_in->pos;
             b->pos = r->header_in->pos;
             b->last = r->header_in->last;
             b->end = r->header_in->end;

             rb->buf = b;

             r->read_event_handler = ngx_http_read_client_request_body_handler;
             r->write_event_handler = ngx_http_request_empty_handler;

             rc = ngx_http_do_read_client_request_body(r);
             goto done;
         }

     } else {
         /* set rb->rest */

         if (ngx_http_request_body_filter(r, NULL) != NGX_OK) {
             rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
             goto done;
         }
     }

     if (rb->rest == 0) {
         /* the whole request body was pre-read */

         if (r->request_body_in_file_only) {
             if (ngx_http_write_request_body(r) != NGX_OK) {
                 rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
                 goto done;
             }

             cl = ngx_chain_get_free_buf(r->pool, &rb->free);
             if (cl == NULL) {
                 rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
                 goto done;
             }

             b = cl->buf;

             ngx_memzero(b, sizeof(ngx_buf_t));

             b->in_file = 1;
             b->file_last = rb->temp_file->file.offset;
             b->file = &rb->temp_file->file;

             rb->bufs = cl;
         }

         post_handler(r);

         return NGX_OK;
     }

     if (rb->rest < 0) {
         ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
                       "negative request body rest");
         rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
         goto done;
     }

     clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

     size = clcf->client_body_buffer_size;
     size += size >> 2;

     /* TODO: honor r->request_body_in_single_buf */

     if (!r->headers_in.chunked && rb->rest < size) {
         size = (ssize_t) rb->rest;

         if (r->request_body_in_single_buf) {
             size += preread;
         }

     } else {
         size = clcf->client_body_buffer_size;
     }

     rb->buf = ngx_create_temp_buf(r->pool, size);
     if (rb->buf == NULL) {
         rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
         goto done;
     }

     r->read_event_handler = ngx_http_read_client_request_body_handler;
     r->write_event_handler = ngx_http_request_empty_handler;

     rc = ngx_http_do_read_client_request_body(r);

 done:

     if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
         r->main->count--;
     }

     return rc;
 }


 static void
 ngx_http_read_client_request_body_handler(ngx_http_request_t *r)
 {
     ngx_int_t  rc;

     if (r->connection->read->timedout) {
         r->connection->timedout = 1;
         ngx_http_finalize_request(r, NGX_HTTP_REQUEST_TIME_OUT);
         return;
     }

     rc = ngx_http_do_read_client_request_body(r);

     if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
         ngx_http_finalize_request(r, rc);
     }
 }


 static ngx_int_t
 ngx_http_do_read_client_request_body(ngx_http_request_t *r)
 {
     off_t                      rest;
     size_t                     size;
     ssize_t                    n;
     ngx_int_t                  rc;
     ngx_buf_t                 *b;
     ngx_chain_t               *cl, out;
     ngx_connection_t          *c;
     ngx_http_request_body_t   *rb;
     ngx_http_core_loc_conf_t  *clcf;

     c = r->connection;
     rb = r->request_body;

     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
                    "http read client request body");

     for ( ;; ) {
         for ( ;; ) {
             if (rb->buf->last == rb->buf->end) {

                 /* pass buffer to request body filter chain */

                 out.buf = rb->buf;
                 out.next = NULL;

                 rc = ngx_http_request_body_filter(r, &out);

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

                 /* write to file */

                 if (ngx_http_write_request_body(r) != NGX_OK) {
                     return NGX_HTTP_INTERNAL_SERVER_ERROR;
                 }

                 /* update chains */

                 rc = ngx_http_request_body_filter(r, NULL);

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

                 if (rb->busy != NULL) {
                     return NGX_HTTP_INTERNAL_SERVER_ERROR;
                 }

                 rb->buf->pos = rb->buf->start;
                 rb->buf->last = rb->buf->start;
             }

             size = rb->buf->end - rb->buf->last;
             rest = rb->rest - (rb->buf->last - rb->buf->pos);

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

             n = c->recv(c, rb->buf->last, size);

             ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                            "http client request body recv %z", n);

             if (n == NGX_AGAIN) {
                 break;
             }

             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;
                 return NGX_HTTP_BAD_REQUEST;
             }

             rb->buf->last += n;
             r->request_length += n;

             if (n == rest) {
                 /* pass buffer to request body filter chain */

                 out.buf = rb->buf;
                 out.next = NULL;

                 rc = ngx_http_request_body_filter(r, &out);

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

             if (rb->rest == 0) {
                 break;
             }

             if (rb->buf->last < rb->buf->end) {
                 break;
             }
         }

         ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                        "http client request body rest %O", rb->rest);

         if (rb->rest == 0) {
             break;
         }

         if (!c->read->ready) {
             clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
             ngx_add_timer(c->read, clcf->client_body_timeout);

             if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
                 return NGX_HTTP_INTERNAL_SERVER_ERROR;
             }

             return NGX_AGAIN;
         }
     }

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

     if (rb->temp_file || r->request_body_in_file_only) {

         /* save the last part */

         if (ngx_http_write_request_body(r) != NGX_OK) {
             return NGX_HTTP_INTERNAL_SERVER_ERROR;
         }

         cl = ngx_chain_get_free_buf(r->pool, &rb->free);
         if (cl == NULL) {
             return NGX_HTTP_INTERNAL_SERVER_ERROR;
         }

         b = cl->buf;

         ngx_memzero(b, sizeof(ngx_buf_t));

         b->in_file = 1;
         b->file_last = rb->temp_file->file.offset;
         b->file = &rb->temp_file->file;

         rb->bufs = cl;
     }

     r->read_event_handler = ngx_http_block_reading;

     rb->post_handler(r);

     return NGX_OK;
 }


 static ngx_int_t
 ngx_http_write_request_body(ngx_http_request_t *r)
 {
     ssize_t                    n;
     ngx_chain_t               *cl;
     ngx_temp_file_t           *tf;
     ngx_http_request_body_t   *rb;
     ngx_http_core_loc_conf_t  *clcf;

     rb = r->request_body;

     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "http write client request body, bufs %p", rb->bufs);

     if (rb->temp_file == NULL) {
         tf = ngx_pcalloc(r->pool, sizeof(ngx_temp_file_t));
         if (tf == NULL) {
             return NGX_ERROR;
         }

         clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

         tf->file.fd = NGX_INVALID_FILE;
         tf->file.log = r->connection->log;
         tf->path = clcf->client_body_temp_path;
         tf->pool = r->pool;
         tf->warn = "a client request body is buffered to a temporary file";
         tf->log_level = r->request_body_file_log_level;
         tf->persistent = r->request_body_in_persistent_file;
         tf->clean = r->request_body_in_clean_file;

         if (r->request_body_file_group_access) {
             tf->access = 0660;
         }

         rb->temp_file = tf;

         if (rb->bufs == NULL) {
             /* empty body with r->request_body_in_file_only */

             if (ngx_create_temp_file(&tf->file, tf->path, tf->pool,
                                      tf->persistent, tf->clean, tf->access)
                 != NGX_OK)
             {
                 return NGX_ERROR;
             }

             return NGX_OK;
         }
     }

     if (rb->bufs == NULL) {
         return NGX_OK;
     }

     n = ngx_write_chain_to_temp_file(rb->temp_file, rb->bufs);

     /* TODO: n == 0 or not complete and level event */

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

     rb->temp_file->offset += n;

     /* mark all buffers as written */

     for (cl = rb->bufs; cl; cl = cl->next) {
         cl->buf->pos = cl->buf->last;
     }

     rb->bufs = NULL;

     return NGX_OK;
 }


 ngx_int_t
 ngx_http_discard_request_body(ngx_http_request_t *r)
 {
     ssize_t       size;
     ngx_int_t     rc;
     ngx_event_t  *rev;

 #if (NGX_HTTP_SPDY)
     if (r->spdy_stream && r == r->main) {
         r->spdy_stream->skip_data = NGX_SPDY_DATA_DISCARD;
         return NGX_OK;
     }
 #endif

     if (r != r->main || r->discard_body || r->request_body) {
         return NGX_OK;
     }

     if (ngx_http_test_expect(r) != NGX_OK) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }

     rev = r->connection->read;

     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0, "http set discard body");

     if (rev->timer_set) {
         ngx_del_timer(rev);
     }

     if (r->headers_in.content_length_n <= 0 && !r->headers_in.chunked) {
         return NGX_OK;
     }

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

     if (size || r->headers_in.chunked) {
         rc = ngx_http_discard_request_body_filter(r, r->header_in);

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

         if (r->headers_in.content_length_n == 0) {
             return NGX_OK;
         }
     }

     rc = ngx_http_read_discarded_request_body(r);

     if (rc == NGX_OK) {
         r->lingering_close = 0;
         return NGX_OK;
     }

     if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
         return rc;
     }

     /* rc == NGX_AGAIN */

     r->read_event_handler = ngx_http_discarded_request_body_handler;

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

     r->count++;
     r->discard_body = 1;

     return NGX_OK;
 }


 void
 ngx_http_discarded_request_body_handler(ngx_http_request_t *r)
 {
     ngx_int_t                  rc;
     ngx_msec_t                 timer;
     ngx_event_t               *rev;
     ngx_connection_t          *c;
     ngx_http_core_loc_conf_t  *clcf;

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

     if (rev->timedout) {
         c->timedout = 1;
         c->error = 1;
         ngx_http_finalize_request(r, NGX_ERROR);
         return;
     }

     if (r->lingering_time) {
         timer = (ngx_msec_t) r->lingering_time - (ngx_msec_t) ngx_time();

         if ((ngx_msec_int_t) timer <= 0) {
             r->discard_body = 0;
             r->lingering_close = 0;
             ngx_http_finalize_request(r, NGX_ERROR);
             return;
         }

     } else {
         timer = 0;
     }

     rc = ngx_http_read_discarded_request_body(r);

     if (rc == NGX_OK) {
         r->discard_body = 0;
         r->lingering_close = 0;
         ngx_http_finalize_request(r, NGX_DONE);
         return;
     }

     if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
         c->error = 1;
         ngx_http_finalize_request(r, NGX_ERROR);
         return;
     }

     /* rc == NGX_AGAIN */

     if (ngx_handle_read_event(rev, 0) != NGX_OK) {
         c->error = 1;
         ngx_http_finalize_request(r, NGX_ERROR);
         return;
     }

     if (timer) {

         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);
     }
 }


 static ngx_int_t
 ngx_http_read_discarded_request_body(ngx_http_request_t *r)
 {
     size_t     size;
     ssize_t    n;
     ngx_int_t  rc;
     ngx_buf_t  b;
     u_char     buffer[NGX_HTTP_DISCARD_BUFFER_SIZE];

     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "http read discarded body");

     ngx_memzero(&b, sizeof(ngx_buf_t));

     b.temporary = 1;

     for ( ;; ) {
         if (r->headers_in.content_length_n == 0) {
             r->read_event_handler = ngx_http_block_reading;
             return NGX_OK;
         }

         if (!r->connection->read->ready) {
             return NGX_AGAIN;
         }

         size = (size_t) ngx_min(r->headers_in.content_length_n,
                                 NGX_HTTP_DISCARD_BUFFER_SIZE);

         n = r->connection->recv(r->connection, buffer, size);

         if (n == NGX_ERROR) {
             r->connection->error = 1;
             return NGX_OK;
         }

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

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

         b.pos = buffer;
         b.last = buffer + n;

         rc = ngx_http_discard_request_body_filter(r, &b);

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


 static ngx_int_t
 ngx_http_discard_request_body_filter(ngx_http_request_t *r, ngx_buf_t *b)
 {
     size_t                    size;
     ngx_int_t                 rc;
     ngx_http_request_body_t  *rb;

     if (r->headers_in.chunked) {

         rb = r->request_body;

         if (rb == NULL) {

             rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t));
             if (rb == NULL) {
                 return NGX_HTTP_INTERNAL_SERVER_ERROR;
             }

             rb->chunked = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_t));
             if (rb->chunked == NULL) {
                 return NGX_HTTP_INTERNAL_SERVER_ERROR;
             }

             r->request_body = rb;
         }

         for ( ;; ) {

             rc = ngx_http_parse_chunked(r, b, rb->chunked);

             if (rc == NGX_OK) {

                 /* a chunk has been parsed successfully */

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

                 if ((off_t) size > rb->chunked->size) {
                     b->pos += rb->chunked->size;
                     rb->chunked->size = 0;

                 } else {
                     rb->chunked->size -= size;
                     b->pos = b->last;
                 }

                 continue;
             }

             if (rc == NGX_DONE) {

                 /* a whole response has been parsed successfully */

                 r->headers_in.content_length_n = 0;
                 break;
             }

             if (rc == NGX_AGAIN) {

                 /* set amount of data we want to see next time */

                 r->headers_in.content_length_n = rb->chunked->length;
                 break;
             }

             /* invalid */

             ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                           "client sent invalid chunked body");

             return NGX_HTTP_BAD_REQUEST;
         }

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

         if ((off_t) size > r->headers_in.content_length_n) {
             b->pos += r->headers_in.content_length_n;
             r->headers_in.content_length_n = 0;

         } else {
             b->pos = b->last;
             r->headers_in.content_length_n -= size;
         }
     }

     return NGX_OK;
 }


 static ngx_int_t
 ngx_http_test_expect(ngx_http_request_t *r)
 {
     ngx_int_t   n;
     ngx_str_t  *expect;

     if (r->expect_tested
         || r->headers_in.expect == NULL
         || r->http_version < NGX_HTTP_VERSION_11)
     {
         return NGX_OK;
     }

     r->expect_tested = 1;

     expect = &r->headers_in.expect->value;

     if (expect->len != sizeof("100-continue") - 1
         || ngx_strncasecmp(expect->data, (u_char *) "100-continue",
                            sizeof("100-continue") - 1)
            != 0)
     {
         return NGX_OK;
     }

     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "send 100 Continue");

     n = r->connection->send(r->connection,
                             (u_char *) "HTTP/1.1 100 Continue" CRLF CRLF,
                             sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1);

     if (n == sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1) {
         return NGX_OK;
     }

     /* we assume that such small packet should be send successfully */

     return NGX_ERROR;
 }


 static ngx_int_t
 ngx_http_request_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
 {
     if (r->headers_in.chunked) {
         return ngx_http_request_body_chunked_filter(r, in);

     } else {
         return ngx_http_request_body_length_filter(r, in);
     }
 }


 static ngx_int_t
 ngx_http_request_body_length_filter(ngx_http_request_t *r, ngx_chain_t *in)
 {
     size_t                     size;
     ngx_int_t                  rc;
     ngx_buf_t                 *b;
     ngx_chain_t               *cl, *tl, *out, **ll;
     ngx_http_request_body_t   *rb;

     rb = r->request_body;

     if (rb->rest == -1) {
         ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                        "http request body content length filter");

         rb->rest = r->headers_in.content_length_n;
     }

     out = NULL;
     ll = &out;

     for (cl = in; cl; cl = cl->next) {

         tl = ngx_chain_get_free_buf(r->pool, &rb->free);
         if (tl == NULL) {
             return NGX_HTTP_INTERNAL_SERVER_ERROR;
         }

         b = tl->buf;

         ngx_memzero(b, sizeof(ngx_buf_t));

         b->temporary = 1;
         b->tag = (ngx_buf_tag_t) &ngx_http_read_client_request_body;
         b->start = cl->buf->pos;
         b->pos = cl->buf->pos;
         b->last = cl->buf->last;
         b->end = cl->buf->end;

         size = cl->buf->last - cl->buf->pos;

         if ((off_t) size < rb->rest) {
             cl->buf->pos = cl->buf->last;
             rb->rest -= size;

         } else {
             cl->buf->pos += rb->rest;
             rb->rest = 0;
             b->last = cl->buf->pos;
             b->last_buf = 1;
         }

         *ll = tl;
         ll = &tl->next;
     }

     rc = ngx_http_request_body_save_filter(r, out);

     ngx_chain_update_chains(r->pool, &rb->free, &rb->busy, &out,
                             (ngx_buf_tag_t) &ngx_http_read_client_request_body);

     return rc;
 }


 static ngx_int_t
 ngx_http_request_body_chunked_filter(ngx_http_request_t *r, ngx_chain_t *in)
 {
     size_t                     size;
     ngx_int_t                  rc;
     ngx_buf_t                 *b;
     ngx_chain_t               *cl, *out, *tl, **ll;
     ngx_http_request_body_t   *rb;
     ngx_http_core_loc_conf_t  *clcf;

     rb = r->request_body;

     if (rb->rest == -1) {

         ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                        "http request body chunked filter");

         rb->chunked = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_t));
         if (rb->chunked == NULL) {
             return NGX_HTTP_INTERNAL_SERVER_ERROR;
         }

         r->headers_in.content_length_n = 0;
         rb->rest = 3;
     }

     out = NULL;
     ll = &out;

     for (cl = in; cl; cl = cl->next) {

         for ( ;; ) {

             ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
                            "http body chunked buf "
                            "t:%d f:%d %p, pos %p, size: %z file: %O, size: %z",
                            cl->buf->temporary, cl->buf->in_file,
                            cl->buf->start, cl->buf->pos,
                            cl->buf->last - cl->buf->pos,
                            cl->buf->file_pos,
                            cl->buf->file_last - cl->buf->file_pos);

             rc = ngx_http_parse_chunked(r, cl->buf, rb->chunked);

             if (rc == NGX_OK) {

                 /* a chunk has been parsed successfully */

                 clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

                 if (clcf->client_max_body_size
                     && clcf->client_max_body_size
                        < r->headers_in.content_length_n + rb->chunked->size)
                 {
                     ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                                   "client intended to send too large chunked "
                                   "body: %O bytes",
                                   r->headers_in.content_length_n
                                   + rb->chunked->size);

                     r->lingering_close = 1;

                     return NGX_HTTP_REQUEST_ENTITY_TOO_LARGE;
                 }

                 tl = ngx_chain_get_free_buf(r->pool, &rb->free);
                 if (tl == NULL) {
                     return NGX_HTTP_INTERNAL_SERVER_ERROR;
                 }

                 b = tl->buf;

                 ngx_memzero(b, sizeof(ngx_buf_t));

                 b->temporary = 1;
                 b->tag = (ngx_buf_tag_t) &ngx_http_read_client_request_body;
                 b->start = cl->buf->pos;
                 b->pos = cl->buf->pos;
                 b->last = cl->buf->last;
                 b->end = cl->buf->end;

                 *ll = tl;
                 ll = &tl->next;

                 size = cl->buf->last - cl->buf->pos;

                 if ((off_t) size > rb->chunked->size) {
                     cl->buf->pos += rb->chunked->size;
                     r->headers_in.content_length_n += rb->chunked->size;
                     rb->chunked->size = 0;

                 } else {
                     rb->chunked->size -= size;
                     r->headers_in.content_length_n += size;
                     cl->buf->pos = cl->buf->last;
                 }

                 b->last = cl->buf->pos;

                 continue;
             }

             if (rc == NGX_DONE) {

                 /* a whole response has been parsed successfully */

                 rb->rest = 0;

                 tl = ngx_chain_get_free_buf(r->pool, &rb->free);
                 if (tl == NULL) {
                     return NGX_HTTP_INTERNAL_SERVER_ERROR;
                 }

                 b = tl->buf;

                 ngx_memzero(b, sizeof(ngx_buf_t));

                 b->last_buf = 1;

                 *ll = tl;
                 ll = &tl->next;

                 break;
             }

             if (rc == NGX_AGAIN) {

                 /* set rb->rest, amount of data we want to see next time */

                 rb->rest = rb->chunked->length;

                 break;
             }

             /* invalid */

             ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                           "client sent invalid chunked body");

             return NGX_HTTP_BAD_REQUEST;
         }
     }

     rc = ngx_http_request_body_save_filter(r, out);

     ngx_chain_update_chains(r->pool, &rb->free, &rb->busy, &out,
                             (ngx_buf_tag_t) &ngx_http_read_client_request_body);

     return rc;
 }


 static ngx_int_t
 ngx_http_request_body_save_filter(ngx_http_request_t *r, ngx_chain_t *in)
 {
 #if (NGX_DEBUG)
     ngx_chain_t               *cl;
 #endif
     ngx_http_request_body_t   *rb;

     rb = r->request_body;

 #if (NGX_DEBUG)

     for (cl = rb->bufs; cl; cl = cl->next) {
         ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
                        "http body old buf t:%d f:%d %p, pos %p, size: %z "
                        "file: %O, size: %z",
                        cl->buf->temporary, cl->buf->in_file,
                        cl->buf->start, cl->buf->pos,
                        cl->buf->last - cl->buf->pos,
                        cl->buf->file_pos,
                        cl->buf->file_last - cl->buf->file_pos);
     }

     for (cl = in; cl; cl = cl->next) {
         ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
                        "http body new buf t:%d f:%d %p, pos %p, size: %z "
                        "file: %O, size: %z",
                        cl->buf->temporary, cl->buf->in_file,
                        cl->buf->start, cl->buf->pos,
                        cl->buf->last - cl->buf->pos,
                        cl->buf->file_pos,
                        cl->buf->file_last - cl->buf->file_pos);
     }

 #endif

     /* TODO: coalesce neighbouring buffers */

     if (ngx_chain_add_copy(r->pool, &rb->bufs, in) != NGX_OK) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }

     return NGX_OK;
 }

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


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


	static void ngx_http_read_client_request_body_handler(ngx_http_request_t *r);
	static ngx_int_t ngx_http_do_read_client_request_body(ngx_http_request_t *r);
	static ngx_int_t ngx_http_write_request_body(ngx_http_request_t *r);
	static ngx_int_t ngx_http_read_discarded_request_body(ngx_http_request_t *r);
	static ngx_int_t ngx_http_discard_request_body_filter(ngx_http_request_t *r,
	ngx_buf_t *b);
	static ngx_int_t ngx_http_test_expect(ngx_http_request_t *r);

	static ngx_int_t ngx_http_request_body_filter(ngx_http_request_t *r,
	ngx_chain_t *in);
	static ngx_int_t ngx_http_request_body_length_filter(ngx_http_request_t *r,
	ngx_chain_t *in);
	static ngx_int_t ngx_http_request_body_chunked_filter(ngx_http_request_t *r,
	ngx_chain_t *in);
	static ngx_int_t ngx_http_request_body_save_filter(ngx_http_request_t *r,
	ngx_chain_t *in);


	ngx_int_t
	ngx_http_read_client_request_body(ngx_http_request_t *r,
	ngx_http_client_body_handler_pt post_handler)
	{
	size_t preread;
	ssize_t size;
	ngx_int_t rc;
	ngx_buf_t *b;
	ngx_chain_t out, *cl;
	ngx_http_request_body_t *rb;
	ngx_http_core_loc_conf_t *clcf;

	r->main->count++;

	#if (NGX_HTTP_SPDY)
	if (r->spdy_stream) {
	rc = ngx_http_spdy_read_request_body(r, post_handler);
	goto done;
	}
	#endif

	if (r != r->main \|\| r->request_body \|\| r->discard_body) {
	post_handler(r);
	return NGX_OK;
	}

	if (ngx_http_test_expect(r) != NGX_OK) {
	rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
	goto done;
	}

	rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t));
	if (rb == NULL) {
	rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
	goto done;
	}

	/*
	* set by ngx_pcalloc():
	*
	* rb->bufs = NULL;
	* rb->buf = NULL;
	* rb->free = NULL;
	* rb->busy = NULL;
	* rb->chunked = NULL;
	*/

	rb->rest = -1;
	rb->post_handler = post_handler;

	r->request_body = rb;

	if (r->headers_in.content_length_n < 0 && !r->headers_in.chunked) {
	post_handler(r);
	return NGX_OK;
	}

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

	if (preread) {

	/* there is the pre-read part of the request body */

	ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
	"http client request body preread %uz", preread);

	out.buf = r->header_in;
	out.next = NULL;

	rc = ngx_http_request_body_filter(r, &out);

	if (rc != NGX_OK) {
	goto done;
	}

	r->request_length += preread - (r->header_in->last - r->header_in->pos);

	if (!r->headers_in.chunked
	&& rb->rest > 0
	&& rb->rest <= (off_t) (r->header_in->end - r->header_in->last))
	{
	/* the whole request body may be placed in r->header_in */

	b = ngx_calloc_buf(r->pool);
	if (b == NULL) {
	rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
	goto done;
	}

	b->temporary = 1;
	b->start = r->header_in->pos;
	b->pos = r->header_in->pos;
	b->last = r->header_in->last;
	b->end = r->header_in->end;

	rb->buf = b;

	r->read_event_handler = ngx_http_read_client_request_body_handler;
	r->write_event_handler = ngx_http_request_empty_handler;

	rc = ngx_http_do_read_client_request_body(r);
	goto done;
	}

	} else {
	/* set rb->rest */

	if (ngx_http_request_body_filter(r, NULL) != NGX_OK) {
	rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
	goto done;
	}
	}

	if (rb->rest == 0) {
	/* the whole request body was pre-read */

	if (r->request_body_in_file_only) {
	if (ngx_http_write_request_body(r) != NGX_OK) {
	rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
	goto done;
	}

	cl = ngx_chain_get_free_buf(r->pool, &rb->free);
	if (cl == NULL) {
	rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
	goto done;
	}

	b = cl->buf;

	ngx_memzero(b, sizeof(ngx_buf_t));

	b->in_file = 1;
	b->file_last = rb->temp_file->file.offset;
	b->file = &rb->temp_file->file;

	rb->bufs = cl;
	}

	post_handler(r);

	return NGX_OK;
	}

	if (rb->rest < 0) {
	ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
	"negative request body rest");
	rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
	goto done;
	}

	clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

	size = clcf->client_body_buffer_size;
	size += size >> 2;

	/* TODO: honor r->request_body_in_single_buf */

	if (!r->headers_in.chunked && rb->rest < size) {
	size = (ssize_t) rb->rest;

	if (r->request_body_in_single_buf) {
	size += preread;
	}

	} else {
	size = clcf->client_body_buffer_size;
	}

	rb->buf = ngx_create_temp_buf(r->pool, size);
	if (rb->buf == NULL) {
	rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
	goto done;
	}

	r->read_event_handler = ngx_http_read_client_request_body_handler;
	r->write_event_handler = ngx_http_request_empty_handler;

	rc = ngx_http_do_read_client_request_body(r);

	done:

	if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
	r->main->count--;
	}

	return rc;
	}


	static void
	ngx_http_read_client_request_body_handler(ngx_http_request_t *r)
	{
	ngx_int_t rc;

	if (r->connection->read->timedout) {
	r->connection->timedout = 1;
	ngx_http_finalize_request(r, NGX_HTTP_REQUEST_TIME_OUT);
	return;
	}

	rc = ngx_http_do_read_client_request_body(r);

	if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
	ngx_http_finalize_request(r, rc);
	}
	}


	static ngx_int_t
	ngx_http_do_read_client_request_body(ngx_http_request_t *r)
	{
	off_t rest;
	size_t size;
	ssize_t n;
	ngx_int_t rc;
	ngx_buf_t *b;
	ngx_chain_t *cl, out;
	ngx_connection_t *c;
	ngx_http_request_body_t *rb;
	ngx_http_core_loc_conf_t *clcf;

	c = r->connection;
	rb = r->request_body;

	ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
	"http read client request body");

	for ( ;; ) {
	for ( ;; ) {
	if (rb->buf->last == rb->buf->end) {

	/* pass buffer to request body filter chain */

	out.buf = rb->buf;
	out.next = NULL;

	rc = ngx_http_request_body_filter(r, &out);

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

	/* write to file */

	if (ngx_http_write_request_body(r) != NGX_OK) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	/* update chains */

	rc = ngx_http_request_body_filter(r, NULL);

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

	if (rb->busy != NULL) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	rb->buf->pos = rb->buf->start;
	rb->buf->last = rb->buf->start;
	}

	size = rb->buf->end - rb->buf->last;
	rest = rb->rest - (rb->buf->last - rb->buf->pos);

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

	n = c->recv(c, rb->buf->last, size);

	ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
	"http client request body recv %z", n);

	if (n == NGX_AGAIN) {
	break;
	}

	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;
	return NGX_HTTP_BAD_REQUEST;
	}

	rb->buf->last += n;
	r->request_length += n;

	if (n == rest) {
	/* pass buffer to request body filter chain */

	out.buf = rb->buf;
	out.next = NULL;

	rc = ngx_http_request_body_filter(r, &out);

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

	if (rb->rest == 0) {
	break;
	}

	if (rb->buf->last < rb->buf->end) {
	break;
	}
	}

	ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
	"http client request body rest %O", rb->rest);

	if (rb->rest == 0) {
	break;
	}

	if (!c->read->ready) {
	clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
	ngx_add_timer(c->read, clcf->client_body_timeout);

	if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	return NGX_AGAIN;
	}
	}

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

	if (rb->temp_file \|\| r->request_body_in_file_only) {

	/* save the last part */

	if (ngx_http_write_request_body(r) != NGX_OK) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	cl = ngx_chain_get_free_buf(r->pool, &rb->free);
	if (cl == NULL) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	b = cl->buf;

	ngx_memzero(b, sizeof(ngx_buf_t));

	b->in_file = 1;
	b->file_last = rb->temp_file->file.offset;
	b->file = &rb->temp_file->file;

	rb->bufs = cl;
	}

	r->read_event_handler = ngx_http_block_reading;

	rb->post_handler(r);

	return NGX_OK;
	}


	static ngx_int_t
	ngx_http_write_request_body(ngx_http_request_t *r)
	{
	ssize_t n;
	ngx_chain_t *cl;
	ngx_temp_file_t *tf;
	ngx_http_request_body_t *rb;
	ngx_http_core_loc_conf_t *clcf;

	rb = r->request_body;

	ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
	"http write client request body, bufs %p", rb->bufs);

	if (rb->temp_file == NULL) {
	tf = ngx_pcalloc(r->pool, sizeof(ngx_temp_file_t));
	if (tf == NULL) {
	return NGX_ERROR;
	}

	clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

	tf->file.fd = NGX_INVALID_FILE;
	tf->file.log = r->connection->log;
	tf->path = clcf->client_body_temp_path;
	tf->pool = r->pool;
	tf->warn = "a client request body is buffered to a temporary file";
	tf->log_level = r->request_body_file_log_level;
	tf->persistent = r->request_body_in_persistent_file;
	tf->clean = r->request_body_in_clean_file;

	if (r->request_body_file_group_access) {
	tf->access = 0660;
	}

	rb->temp_file = tf;

	if (rb->bufs == NULL) {
	/* empty body with r->request_body_in_file_only */

	if (ngx_create_temp_file(&tf->file, tf->path, tf->pool,
	tf->persistent, tf->clean, tf->access)
	!= NGX_OK)
	{
	return NGX_ERROR;
	}

	return NGX_OK;
	}
	}

	if (rb->bufs == NULL) {
	return NGX_OK;
	}

	n = ngx_write_chain_to_temp_file(rb->temp_file, rb->bufs);

	/* TODO: n == 0 or not complete and level event */

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

	rb->temp_file->offset += n;

	/* mark all buffers as written */

	for (cl = rb->bufs; cl; cl = cl->next) {
	cl->buf->pos = cl->buf->last;
	}

	rb->bufs = NULL;

	return NGX_OK;
	}


	ngx_int_t
	ngx_http_discard_request_body(ngx_http_request_t *r)
	{
	ssize_t size;
	ngx_int_t rc;
	ngx_event_t *rev;

	#if (NGX_HTTP_SPDY)
	if (r->spdy_stream && r == r->main) {
	r->spdy_stream->skip_data = NGX_SPDY_DATA_DISCARD;
	return NGX_OK;
	}
	#endif

	if (r != r->main \|\| r->discard_body \|\| r->request_body) {
	return NGX_OK;
	}

	if (ngx_http_test_expect(r) != NGX_OK) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	rev = r->connection->read;

	ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0, "http set discard body");

	if (rev->timer_set) {
	ngx_del_timer(rev);
	}

	if (r->headers_in.content_length_n <= 0 && !r->headers_in.chunked) {
	return NGX_OK;
	}

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

	if (size \|\| r->headers_in.chunked) {
	rc = ngx_http_discard_request_body_filter(r, r->header_in);

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

	if (r->headers_in.content_length_n == 0) {
	return NGX_OK;
	}
	}

	rc = ngx_http_read_discarded_request_body(r);

	if (rc == NGX_OK) {
	r->lingering_close = 0;
	return NGX_OK;
	}

	if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
	return rc;
	}

	/* rc == NGX_AGAIN */

	r->read_event_handler = ngx_http_discarded_request_body_handler;

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

	r->count++;
	r->discard_body = 1;

	return NGX_OK;
	}


	void
	ngx_http_discarded_request_body_handler(ngx_http_request_t *r)
	{
	ngx_int_t rc;
	ngx_msec_t timer;
	ngx_event_t *rev;
	ngx_connection_t *c;
	ngx_http_core_loc_conf_t *clcf;

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

	if (rev->timedout) {
	c->timedout = 1;
	c->error = 1;
	ngx_http_finalize_request(r, NGX_ERROR);
	return;
	}

	if (r->lingering_time) {
	timer = (ngx_msec_t) r->lingering_time - (ngx_msec_t) ngx_time();

	if ((ngx_msec_int_t) timer <= 0) {
	r->discard_body = 0;
	r->lingering_close = 0;
	ngx_http_finalize_request(r, NGX_ERROR);
	return;
	}

	} else {
	timer = 0;
	}

	rc = ngx_http_read_discarded_request_body(r);

	if (rc == NGX_OK) {
	r->discard_body = 0;
	r->lingering_close = 0;
	ngx_http_finalize_request(r, NGX_DONE);
	return;
	}

	if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
	c->error = 1;
	ngx_http_finalize_request(r, NGX_ERROR);
	return;
	}

	/* rc == NGX_AGAIN */

	if (ngx_handle_read_event(rev, 0) != NGX_OK) {
	c->error = 1;
	ngx_http_finalize_request(r, NGX_ERROR);
	return;
	}

	if (timer) {

	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);
	}
	}


	static ngx_int_t
	ngx_http_read_discarded_request_body(ngx_http_request_t *r)
	{
	size_t size;
	ssize_t n;
	ngx_int_t rc;
	ngx_buf_t b;
	u_char buffer[NGX_HTTP_DISCARD_BUFFER_SIZE];

	ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
	"http read discarded body");

	ngx_memzero(&b, sizeof(ngx_buf_t));

	b.temporary = 1;

	for ( ;; ) {
	if (r->headers_in.content_length_n == 0) {
	r->read_event_handler = ngx_http_block_reading;
	return NGX_OK;
	}

	if (!r->connection->read->ready) {
	return NGX_AGAIN;
	}

	size = (size_t) ngx_min(r->headers_in.content_length_n,
	NGX_HTTP_DISCARD_BUFFER_SIZE);

	n = r->connection->recv(r->connection, buffer, size);

	if (n == NGX_ERROR) {
	r->connection->error = 1;
	return NGX_OK;
	}

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

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

	b.pos = buffer;
	b.last = buffer + n;

	rc = ngx_http_discard_request_body_filter(r, &b);

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


	static ngx_int_t
	ngx_http_discard_request_body_filter(ngx_http_request_t r, ngx_buf_t b)
	{
	size_t size;
	ngx_int_t rc;
	ngx_http_request_body_t *rb;

	if (r->headers_in.chunked) {

	rb = r->request_body;

	if (rb == NULL) {

	rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t));
	if (rb == NULL) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	rb->chunked = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_t));
	if (rb->chunked == NULL) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	r->request_body = rb;
	}

	for ( ;; ) {

	rc = ngx_http_parse_chunked(r, b, rb->chunked);

	if (rc == NGX_OK) {

	/* a chunk has been parsed successfully */

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

	if ((off_t) size > rb->chunked->size) {
	b->pos += rb->chunked->size;
	rb->chunked->size = 0;

	} else {
	rb->chunked->size -= size;
	b->pos = b->last;
	}

	continue;
	}

	if (rc == NGX_DONE) {

	/* a whole response has been parsed successfully */

	r->headers_in.content_length_n = 0;
	break;
	}

	if (rc == NGX_AGAIN) {

	/* set amount of data we want to see next time */

	r->headers_in.content_length_n = rb->chunked->length;
	break;
	}

	/* invalid */

	ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
	"client sent invalid chunked body");

	return NGX_HTTP_BAD_REQUEST;
	}

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

	if ((off_t) size > r->headers_in.content_length_n) {
	b->pos += r->headers_in.content_length_n;
	r->headers_in.content_length_n = 0;

	} else {
	b->pos = b->last;
	r->headers_in.content_length_n -= size;
	}
	}

	return NGX_OK;
	}


	static ngx_int_t
	ngx_http_test_expect(ngx_http_request_t *r)
	{
	ngx_int_t n;
	ngx_str_t *expect;

	if (r->expect_tested
	\|\| r->headers_in.expect == NULL
	\|\| r->http_version < NGX_HTTP_VERSION_11)
	{
	return NGX_OK;
	}

	r->expect_tested = 1;

	expect = &r->headers_in.expect->value;

	if (expect->len != sizeof("100-continue") - 1
	\|\| ngx_strncasecmp(expect->data, (u_char *) "100-continue",
	sizeof("100-continue") - 1)
	!= 0)
	{
	return NGX_OK;
	}

	ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
	"send 100 Continue");

	n = r->connection->send(r->connection,
	(u_char *) "HTTP/1.1 100 Continue" CRLF CRLF,
	sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1);

	if (n == sizeof("HTTP/1.1 100 Continue" CRLF CRLF) - 1) {
	return NGX_OK;
	}

	/* we assume that such small packet should be send successfully */

	return NGX_ERROR;
	}


	static ngx_int_t
	ngx_http_request_body_filter(ngx_http_request_t r, ngx_chain_t in)
	{
	if (r->headers_in.chunked) {
	return ngx_http_request_body_chunked_filter(r, in);

	} else {
	return ngx_http_request_body_length_filter(r, in);
	}
	}


	static ngx_int_t
	ngx_http_request_body_length_filter(ngx_http_request_t r, ngx_chain_t in)
	{
	size_t size;
	ngx_int_t rc;
	ngx_buf_t *b;
	ngx_chain_t cl, tl, out, *ll;
	ngx_http_request_body_t *rb;

	rb = r->request_body;

	if (rb->rest == -1) {
	ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
	"http request body content length filter");

	rb->rest = r->headers_in.content_length_n;
	}

	out = NULL;
	ll = &out;

	for (cl = in; cl; cl = cl->next) {

	tl = ngx_chain_get_free_buf(r->pool, &rb->free);
	if (tl == NULL) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	b = tl->buf;

	ngx_memzero(b, sizeof(ngx_buf_t));

	b->temporary = 1;
	b->tag = (ngx_buf_tag_t) &ngx_http_read_client_request_body;
	b->start = cl->buf->pos;
	b->pos = cl->buf->pos;
	b->last = cl->buf->last;
	b->end = cl->buf->end;

	size = cl->buf->last - cl->buf->pos;

	if ((off_t) size < rb->rest) {
	cl->buf->pos = cl->buf->last;
	rb->rest -= size;

	} else {
	cl->buf->pos += rb->rest;
	rb->rest = 0;
	b->last = cl->buf->pos;
	b->last_buf = 1;
	}

	*ll = tl;
	ll = &tl->next;
	}

	rc = ngx_http_request_body_save_filter(r, out);

	ngx_chain_update_chains(r->pool, &rb->free, &rb->busy, &out,
	(ngx_buf_tag_t) &ngx_http_read_client_request_body);

	return rc;
	}


	static ngx_int_t
	ngx_http_request_body_chunked_filter(ngx_http_request_t r, ngx_chain_t in)
	{
	size_t size;
	ngx_int_t rc;
	ngx_buf_t *b;
	ngx_chain_t cl, out, tl, *ll;
	ngx_http_request_body_t *rb;
	ngx_http_core_loc_conf_t *clcf;

	rb = r->request_body;

	if (rb->rest == -1) {

	ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
	"http request body chunked filter");

	rb->chunked = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_t));
	if (rb->chunked == NULL) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	r->headers_in.content_length_n = 0;
	rb->rest = 3;
	}

	out = NULL;
	ll = &out;

	for (cl = in; cl; cl = cl->next) {

	for ( ;; ) {

	ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
	"http body chunked buf "
	"t:%d f:%d %p, pos %p, size: %z file: %O, size: %z",
	cl->buf->temporary, cl->buf->in_file,
	cl->buf->start, cl->buf->pos,
	cl->buf->last - cl->buf->pos,
	cl->buf->file_pos,
	cl->buf->file_last - cl->buf->file_pos);

	rc = ngx_http_parse_chunked(r, cl->buf, rb->chunked);

	if (rc == NGX_OK) {

	/* a chunk has been parsed successfully */

	clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

	if (clcf->client_max_body_size
	&& clcf->client_max_body_size
	< r->headers_in.content_length_n + rb->chunked->size)
	{
	ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
	"client intended to send too large chunked "
	"body: %O bytes",
	r->headers_in.content_length_n
	+ rb->chunked->size);

	r->lingering_close = 1;

	return NGX_HTTP_REQUEST_ENTITY_TOO_LARGE;
	}

	tl = ngx_chain_get_free_buf(r->pool, &rb->free);
	if (tl == NULL) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	b = tl->buf;

	ngx_memzero(b, sizeof(ngx_buf_t));

	b->temporary = 1;
	b->tag = (ngx_buf_tag_t) &ngx_http_read_client_request_body;
	b->start = cl->buf->pos;
	b->pos = cl->buf->pos;
	b->last = cl->buf->last;
	b->end = cl->buf->end;

	*ll = tl;
	ll = &tl->next;

	size = cl->buf->last - cl->buf->pos;

	if ((off_t) size > rb->chunked->size) {
	cl->buf->pos += rb->chunked->size;
	r->headers_in.content_length_n += rb->chunked->size;
	rb->chunked->size = 0;

	} else {
	rb->chunked->size -= size;
	r->headers_in.content_length_n += size;
	cl->buf->pos = cl->buf->last;
	}

	b->last = cl->buf->pos;

	continue;
	}

	if (rc == NGX_DONE) {

	/* a whole response has been parsed successfully */

	rb->rest = 0;

	tl = ngx_chain_get_free_buf(r->pool, &rb->free);
	if (tl == NULL) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	b = tl->buf;

	ngx_memzero(b, sizeof(ngx_buf_t));

	b->last_buf = 1;

	*ll = tl;
	ll = &tl->next;

	break;
	}

	if (rc == NGX_AGAIN) {

	/* set rb->rest, amount of data we want to see next time */

	rb->rest = rb->chunked->length;

	break;
	}

	/* invalid */

	ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
	"client sent invalid chunked body");

	return NGX_HTTP_BAD_REQUEST;
	}
	}

	rc = ngx_http_request_body_save_filter(r, out);

	ngx_chain_update_chains(r->pool, &rb->free, &rb->busy, &out,
	(ngx_buf_tag_t) &ngx_http_read_client_request_body);

	return rc;
	}


	static ngx_int_t
	ngx_http_request_body_save_filter(ngx_http_request_t r, ngx_chain_t in)
	{
	#if (NGX_DEBUG)
	ngx_chain_t *cl;
	#endif
	ngx_http_request_body_t *rb;

	rb = r->request_body;

	#if (NGX_DEBUG)

	for (cl = rb->bufs; cl; cl = cl->next) {
	ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
	"http body old buf t:%d f:%d %p, pos %p, size: %z "
	"file: %O, size: %z",
	cl->buf->temporary, cl->buf->in_file,
	cl->buf->start, cl->buf->pos,
	cl->buf->last - cl->buf->pos,
	cl->buf->file_pos,
	cl->buf->file_last - cl->buf->file_pos);
	}

	for (cl = in; cl; cl = cl->next) {
	ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
	"http body new buf t:%d f:%d %p, pos %p, size: %z "
	"file: %O, size: %z",
	cl->buf->temporary, cl->buf->in_file,
	cl->buf->start, cl->buf->pos,
	cl->buf->last - cl->buf->pos,
	cl->buf->file_pos,
	cl->buf->file_last - cl->buf->file_pos);
	}

	#endif

	/* TODO: coalesce neighbouring buffers */

	if (ngx_chain_add_copy(r->pool, &rb->bufs, in) != NGX_OK) {
	return NGX_HTTP_INTERNAL_SERVER_ERROR;
	}

	return NGX_OK;
	}