Initial check in of curl.

Plan to:
- Fix warnings
- Add java support

Change-Id: Ia61d4d479aa61178f2883161491ab844301317e0
diff --git a/lib/transfer.c b/lib/transfer.c
new file mode 100644
index 0000000..2d50405
--- /dev/null
+++ b/lib/transfer.c
@@ -0,0 +1,2250 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2010, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "setup.h"
+
+/* -- WIN32 approved -- */
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <errno.h>
+
+#include "strtoofft.h"
+#include "strequal.h"
+#include "rawstr.h"
+
+#ifdef WIN32
+#include <time.h>
+#include <io.h>
+#else
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_NET_IF_H
+#include <net/if.h>
+#endif
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+#ifdef HAVE_SIGNAL_H
+#include <signal.h>
+#endif
+
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
+
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
+#ifndef HAVE_SOCKET
+#error "We can't compile without socket() support!"
+#endif
+
+#endif  /* WIN32 */
+
+#include "urldata.h"
+#include <curl/curl.h>
+#include "netrc.h"
+
+#include "content_encoding.h"
+#include "hostip.h"
+#include "transfer.h"
+#include "sendf.h"
+#include "speedcheck.h"
+#include "progress.h"
+#include "http.h"
+#include "url.h"
+#include "getinfo.h"
+#include "sslgen.h"
+#include "http_digest.h"
+#include "http_ntlm.h"
+#include "http_negotiate.h"
+#include "share.h"
+#include "curl_memory.h"
+#include "select.h"
+#include "multiif.h"
+#include "easyif.h" /* for Curl_convert_to_network prototype */
+#include "rtsp.h"
+
+#define _MPRINTF_REPLACE /* use our functions only */
+#include <curl/mprintf.h>
+
+/* The last #include file should be: */
+#include "memdebug.h"
+
+#define CURL_TIMEOUT_EXPECT_100 1000 /* counting ms here */
+
+/*
+ * This function will call the read callback to fill our buffer with data
+ * to upload.
+ */
+CURLcode Curl_fillreadbuffer(struct connectdata *conn, int bytes, int *nreadp)
+{
+  struct SessionHandle *data = conn->data;
+  size_t buffersize = (size_t)bytes;
+  int nread;
+#ifdef CURL_DOES_CONVERSIONS
+  bool sending_http_headers = FALSE;
+
+  if((conn->protocol&(PROT_HTTP|PROT_RTSP)) &&
+     (data->state.proto.http->sending == HTTPSEND_REQUEST)) {
+    /* We're sending the HTTP request headers, not the data.
+       Remember that so we don't re-translate them into garbage. */
+    sending_http_headers = TRUE;
+  }
+#endif
+
+  if(data->req.upload_chunky) {
+    /* if chunked Transfer-Encoding */
+    buffersize -= (8 + 2 + 2);   /* 32bit hex + CRLF + CRLF */
+    data->req.upload_fromhere += (8 + 2); /* 32bit hex + CRLF */
+  }
+
+  /* this function returns a size_t, so we typecast to int to prevent warnings
+     with picky compilers */
+  nread = (int)conn->fread_func(data->req.upload_fromhere, 1,
+                                buffersize, conn->fread_in);
+
+  if(nread == CURL_READFUNC_ABORT) {
+    failf(data, "operation aborted by callback");
+    *nreadp = 0;
+    return CURLE_ABORTED_BY_CALLBACK;
+  }
+  else if(nread == CURL_READFUNC_PAUSE) {
+    struct SingleRequest *k = &data->req;
+    /* CURL_READFUNC_PAUSE pauses read callbacks that feed socket writes */
+    k->keepon |= KEEP_SEND_PAUSE; /* mark socket send as paused */
+    if(data->req.upload_chunky) {
+      /* Back out the preallocation done above */
+      data->req.upload_fromhere -= (8 + 2);
+    }
+    *nreadp = 0;
+    return CURLE_OK; /* nothing was read */
+  }
+  else if((size_t)nread > buffersize) {
+    /* the read function returned a too large value */
+    *nreadp = 0;
+    failf(data, "read function returned funny value");
+    return CURLE_READ_ERROR;
+  }
+
+  if(!data->req.forbidchunk && data->req.upload_chunky) {
+    /* if chunked Transfer-Encoding
+     *    build chunk:
+     *
+     *        <HEX SIZE> CRLF
+     *        <DATA> CRLF
+     */
+    /* On non-ASCII platforms the <DATA> may or may not be
+       translated based on set.prefer_ascii while the protocol
+       portion must always be translated to the network encoding.
+       To further complicate matters, line end conversion might be
+       done later on, so we need to prevent CRLFs from becoming
+       CRCRLFs if that's the case.  To do this we use bare LFs
+       here, knowing they'll become CRLFs later on.
+     */
+
+    char hexbuffer[11];
+    const char *endofline_native;
+    const char *endofline_network;
+    int hexlen;
+#ifdef CURL_DO_LINEEND_CONV
+    if((data->set.crlf) || (data->set.prefer_ascii)) {
+#else
+    if(data->set.crlf) {
+#endif /* CURL_DO_LINEEND_CONV */
+      /* \n will become \r\n later on */
+      endofline_native  = "\n";
+      endofline_network = "\x0a";
+    } else {
+      endofline_native  = "\r\n";
+      endofline_network = "\x0d\x0a";
+    }
+    hexlen = snprintf(hexbuffer, sizeof(hexbuffer),
+                      "%x%s", nread, endofline_native);
+
+    /* move buffer pointer */
+    data->req.upload_fromhere -= hexlen;
+    nread += hexlen;
+
+    /* copy the prefix to the buffer, leaving out the NUL */
+    memcpy(data->req.upload_fromhere, hexbuffer, hexlen);
+
+    /* always append ASCII CRLF to the data */
+    memcpy(data->req.upload_fromhere + nread,
+           endofline_network,
+           strlen(endofline_network));
+
+#ifdef CURL_DOES_CONVERSIONS
+    CURLcode res;
+    int length;
+    if(data->set.prefer_ascii) {
+      /* translate the protocol and data */
+      length = nread;
+    } else {
+      /* just translate the protocol portion */
+      length = strlen(hexbuffer);
+    }
+    res = Curl_convert_to_network(data, data->req.upload_fromhere, length);
+    /* Curl_convert_to_network calls failf if unsuccessful */
+    if(res != CURLE_OK) {
+      return(res);
+    }
+#endif /* CURL_DOES_CONVERSIONS */
+
+    if((nread - hexlen) == 0) {
+      /* mark this as done once this chunk is transfered */
+      data->req.upload_done = TRUE;
+    }
+
+    nread+=(int)strlen(endofline_native); /* for the added end of line */
+  }
+#ifdef CURL_DOES_CONVERSIONS
+  else if((data->set.prefer_ascii) && (!sending_http_headers)) {
+    CURLcode res;
+    res = Curl_convert_to_network(data, data->req.upload_fromhere, nread);
+    /* Curl_convert_to_network calls failf if unsuccessful */
+    if(res != CURLE_OK)
+      return(res);
+  }
+#endif /* CURL_DOES_CONVERSIONS */
+
+  *nreadp = nread;
+
+  return CURLE_OK;
+}
+
+
+/*
+ * Curl_readrewind() rewinds the read stream. This is typically used for HTTP
+ * POST/PUT with multi-pass authentication when a sending was denied and a
+ * resend is necessary.
+ */
+CURLcode Curl_readrewind(struct connectdata *conn)
+{
+  struct SessionHandle *data = conn->data;
+
+  conn->bits.rewindaftersend = FALSE; /* we rewind now */
+
+  /* explicitly switch off sending data on this connection now since we are
+     about to restart a new transfer and thus we want to avoid inadvertently
+     sending more data on the existing connection until the next transfer
+     starts */
+  data->req.keepon &= ~KEEP_SEND;
+
+  /* We have sent away data. If not using CURLOPT_POSTFIELDS or
+     CURLOPT_HTTPPOST, call app to rewind
+  */
+  if(data->set.postfields ||
+     (data->set.httpreq == HTTPREQ_POST_FORM))
+    ; /* do nothing */
+  else {
+    if(data->set.seek_func) {
+      int err;
+
+      err = (data->set.seek_func)(data->set.seek_client, 0, SEEK_SET);
+      if(err) {
+        failf(data, "seek callback returned error %d", (int)err);
+        return CURLE_SEND_FAIL_REWIND;
+      }
+    }
+    else if(data->set.ioctl_func) {
+      curlioerr err;
+
+      err = (data->set.ioctl_func)(data, CURLIOCMD_RESTARTREAD,
+                                   data->set.ioctl_client);
+      infof(data, "the ioctl callback returned %d\n", (int)err);
+
+      if(err) {
+        /* FIXME: convert to a human readable error message */
+        failf(data, "ioctl callback returned error %d", (int)err);
+        return CURLE_SEND_FAIL_REWIND;
+      }
+    }
+    else {
+      /* If no CURLOPT_READFUNCTION is used, we know that we operate on a
+         given FILE * stream and we can actually attempt to rewind that
+         ourself with fseek() */
+      if(data->set.fread_func == (curl_read_callback)fread) {
+        if(-1 != fseek(data->set.in, 0, SEEK_SET))
+          /* successful rewind */
+          return CURLE_OK;
+      }
+
+      /* no callback set or failure above, makes us fail at once */
+      failf(data, "necessary data rewind wasn't possible");
+      return CURLE_SEND_FAIL_REWIND;
+    }
+  }
+  return CURLE_OK;
+}
+
+static int data_pending(const struct connectdata *conn)
+{
+  /* in the case of libssh2, we can never be really sure that we have emptied
+     its internal buffers so we MUST always try until we get EAGAIN back */
+  return conn->protocol&(PROT_SCP|PROT_SFTP) ||
+    Curl_ssl_data_pending(conn, FIRSTSOCKET);
+}
+
+static void read_rewind(struct connectdata *conn,
+                        size_t thismuch)
+{
+  DEBUGASSERT(conn->read_pos >= thismuch);
+
+  conn->read_pos -= thismuch;
+  conn->bits.stream_was_rewound = TRUE;
+
+#ifdef DEBUGBUILD
+  {
+    char buf[512 + 1];
+    size_t show;
+
+    show = CURLMIN(conn->buf_len - conn->read_pos, sizeof(buf)-1);
+    if(conn->master_buffer) {
+        memcpy(buf, conn->master_buffer + conn->read_pos, show);
+        buf[show] = '\0';
+    }
+    else {
+        buf[0] = '\0';
+    }
+
+    DEBUGF(infof(conn->data,
+                 "Buffer after stream rewind (read_pos = %zu): [%s]",
+                 conn->read_pos, buf));
+  }
+#endif
+}
+
+
+/*
+ * Go ahead and do a read if we have a readable socket or if
+ * the stream was rewound (in which case we have data in a
+ * buffer)
+ */
+static CURLcode readwrite_data(struct SessionHandle *data,
+                               struct connectdata *conn,
+                               struct SingleRequest *k,
+                               int *didwhat, bool *done)
+{
+  CURLcode result = CURLE_OK;
+  ssize_t nread; /* number of bytes read */
+  size_t excess = 0; /* excess bytes read */
+  bool is_empty_data = FALSE;
+#ifndef CURL_DISABLE_RTSP
+  bool readmore = FALSE; /* used by RTP to signal for more data */
+#endif
+
+  *done = FALSE;
+
+  /* This is where we loop until we have read everything there is to
+     read or we get a EWOULDBLOCK */
+  do {
+    size_t buffersize = data->set.buffer_size?
+      data->set.buffer_size : BUFSIZE;
+    size_t bytestoread = buffersize;
+    int readrc;
+
+    if(k->size != -1 && !k->header) {
+      /* make sure we don't read "too much" if we can help it since we
+         might be pipelining and then someone else might want to read what
+         follows! */
+      curl_off_t totalleft = k->size - k->bytecount;
+      if(totalleft < (curl_off_t)bytestoread)
+        bytestoread = (size_t)totalleft;
+    }
+
+    if(bytestoread) {
+      /* receive data from the network! */
+      readrc = Curl_read(conn, conn->sockfd, k->buf, bytestoread, &nread);
+
+      /* subzero, this would've blocked */
+      if(0 > readrc)
+        break; /* get out of loop */
+
+      /* get the CURLcode from the int */
+      result = (CURLcode)readrc;
+
+      if(result>0)
+        return result;
+    }
+    else {
+      /* read nothing but since we wanted nothing we consider this an OK
+         situation to proceed from */
+      nread = 0;
+    }
+
+    if((k->bytecount == 0) && (k->writebytecount == 0)) {
+      Curl_pgrsTime(data, TIMER_STARTTRANSFER);
+      if(k->exp100 > EXP100_SEND_DATA)
+        /* set time stamp to compare with when waiting for the 100 */
+        k->start100 = Curl_tvnow();
+    }
+
+    *didwhat |= KEEP_RECV;
+    /* indicates data of zero size, i.e. empty file */
+    is_empty_data = (bool)((nread == 0) && (k->bodywrites == 0));
+
+    /* NUL terminate, allowing string ops to be used */
+    if(0 < nread || is_empty_data) {
+      k->buf[nread] = 0;
+    }
+    else if(0 >= nread) {
+      /* if we receive 0 or less here, the server closed the connection
+         and we bail out from this! */
+      DEBUGF(infof(data, "nread <= 0, server closed connection, bailing\n"));
+      k->keepon &= ~KEEP_RECV;
+      break;
+    }
+
+    /* Default buffer to use when we write the buffer, it may be changed
+       in the flow below before the actual storing is done. */
+    k->str = k->buf;
+
+#ifndef CURL_DISABLE_RTSP
+    /* Check for RTP at the beginning of the data */
+    if(conn->protocol & PROT_RTSP) {
+      result = Curl_rtsp_rtp_readwrite(data, conn, &nread, &readmore);
+      if(result)
+        return result;
+      if(readmore)
+        break;
+    }
+#endif
+
+#ifndef CURL_DISABLE_HTTP
+    /* Since this is a two-state thing, we check if we are parsing
+       headers at the moment or not. */
+    if(k->header) {
+      /* we are in parse-the-header-mode */
+      bool stop_reading = FALSE;
+      result = Curl_http_readwrite_headers(data, conn, &nread, &stop_reading);
+      if(result)
+        return result;
+
+#ifndef CURL_DISABLE_RTSP
+      /* Check for RTP after the headers if there is no Content */
+      if(k->maxdownload <= 0 && nread > 0 && (conn->protocol & PROT_RTSP)) {
+        result = Curl_rtsp_rtp_readwrite(data, conn, &nread, &readmore);
+        if(result)
+          return result;
+        if(readmore)
+          break;
+      }
+#endif
+
+      if(stop_reading)
+        /* We've stopped dealing with input, get out of the do-while loop */
+        break;
+    }
+#endif /* CURL_DISABLE_HTTP */
+
+
+    /* This is not an 'else if' since it may be a rest from the header
+       parsing, where the beginning of the buffer is headers and the end
+       is non-headers. */
+    if(k->str && !k->header && (nread > 0 || is_empty_data)) {
+
+
+#ifndef CURL_DISABLE_HTTP
+      if(0 == k->bodywrites && !is_empty_data) {
+        /* These checks are only made the first time we are about to
+           write a piece of the body */
+        if(conn->protocol&(PROT_HTTP|PROT_RTSP)) {
+          /* HTTP-only checks */
+
+          if(data->req.newurl) {
+            if(conn->bits.close) {
+              /* Abort after the headers if "follow Location" is set
+                 and we're set to close anyway. */
+              k->keepon &= ~KEEP_RECV;
+              *done = TRUE;
+              return CURLE_OK;
+            }
+            /* We have a new url to load, but since we want to be able
+               to re-use this connection properly, we read the full
+               response in "ignore more" */
+            k->ignorebody = TRUE;
+            infof(data, "Ignoring the response-body\n");
+          }
+          if(data->state.resume_from && !k->content_range &&
+             (data->set.httpreq==HTTPREQ_GET) &&
+             !k->ignorebody) {
+            /* we wanted to resume a download, although the server doesn't
+             * seem to support this and we did this with a GET (if it
+             * wasn't a GET we did a POST or PUT resume) */
+            failf(data, "HTTP server doesn't seem to support "
+                  "byte ranges. Cannot resume.");
+            return CURLE_RANGE_ERROR;
+          }
+
+          if(data->set.timecondition && !data->state.range) {
+            /* A time condition has been set AND no ranges have been
+               requested. This seems to be what chapter 13.3.4 of
+               RFC 2616 defines to be the correct action for a
+               HTTP/1.1 client */
+            if((k->timeofdoc > 0) && (data->set.timevalue > 0)) {
+              switch(data->set.timecondition) {
+              case CURL_TIMECOND_IFMODSINCE:
+              default:
+                if(k->timeofdoc < data->set.timevalue) {
+                  infof(data,
+                        "The requested document is not new enough\n");
+                  *done = TRUE;
+                  data->info.timecond = TRUE;
+                  return CURLE_OK;
+                }
+                break;
+              case CURL_TIMECOND_IFUNMODSINCE:
+                if(k->timeofdoc > data->set.timevalue) {
+                  infof(data,
+                        "The requested document is not old enough\n");
+                  *done = TRUE;
+                  data->info.timecond = TRUE;
+                  return CURLE_OK;
+                }
+                break;
+              } /* switch */
+            } /* two valid time strings */
+          } /* we have a time condition */
+
+        } /* this is HTTP */
+      } /* this is the first time we write a body part */
+#endif /* CURL_DISABLE_HTTP */
+      k->bodywrites++;
+
+      /* pass data to the debug function before it gets "dechunked" */
+      if(data->set.verbose) {
+        if(k->badheader) {
+          Curl_debug(data, CURLINFO_DATA_IN, data->state.headerbuff,
+                     (size_t)k->hbuflen, conn);
+          if(k->badheader == HEADER_PARTHEADER)
+            Curl_debug(data, CURLINFO_DATA_IN,
+                       k->str, (size_t)nread, conn);
+        }
+        else
+          Curl_debug(data, CURLINFO_DATA_IN,
+                     k->str, (size_t)nread, conn);
+      }
+
+#ifndef CURL_DISABLE_HTTP
+      if(k->chunk) {
+        /*
+         * Here comes a chunked transfer flying and we need to decode this
+         * properly.  While the name says read, this function both reads
+         * and writes away the data. The returned 'nread' holds the number
+         * of actual data it wrote to the client.
+         */
+
+        CHUNKcode res =
+          Curl_httpchunk_read(conn, k->str, nread, &nread);
+
+        if(CHUNKE_OK < res) {
+          if(CHUNKE_WRITE_ERROR == res) {
+            failf(data, "Failed writing data");
+            return CURLE_WRITE_ERROR;
+          }
+          failf(data, "Received problem %d in the chunky parser", (int)res);
+          return CURLE_RECV_ERROR;
+        }
+        else if(CHUNKE_STOP == res) {
+          size_t dataleft;
+          /* we're done reading chunks! */
+          k->keepon &= ~KEEP_RECV; /* read no more */
+
+          /* There are now possibly N number of bytes at the end of the
+             str buffer that weren't written to the client.
+
+             We DO care about this data if we are pipelining.
+             Push it back to be read on the next pass. */
+
+          dataleft = conn->chunk.dataleft;
+          if(dataleft != 0) {
+            infof(conn->data, "Leftovers after chunking. "
+                  " Rewinding %zu bytes\n",dataleft);
+            read_rewind(conn, dataleft);
+          }
+        }
+        /* If it returned OK, we just keep going */
+      }
+#endif   /* CURL_DISABLE_HTTP */
+
+      /* Account for body content stored in the header buffer */
+      if(k->badheader && !k->ignorebody) {
+        DEBUGF(infof(data, "Increasing bytecount by %zu from hbuflen\n",
+                     k->hbuflen));
+        k->bytecount += k->hbuflen;
+      }
+
+      if((-1 != k->maxdownload) &&
+         (k->bytecount + nread >= k->maxdownload)) {
+
+        excess = (size_t)(k->bytecount + nread - k->maxdownload);
+        if(excess > 0 && !k->ignorebody) {
+          if(conn->data->multi && Curl_multi_canPipeline(conn->data->multi)) {
+            /* The 'excess' amount below can't be more than BUFSIZE which
+               always will fit in a size_t */
+            infof(data,
+                "Rewinding stream by : %zu"
+                " bytes on url %s (size = %" FORMAT_OFF_T
+                ", maxdownload = %" FORMAT_OFF_T
+                ", bytecount = %" FORMAT_OFF_T ", nread = %zd)\n",
+                excess, data->state.path,
+                k->size, k->maxdownload, k->bytecount, nread);
+            read_rewind(conn, excess);
+          }
+          else {
+            infof(data,
+                "Excess found in a non pipelined read:"
+                " excess = %zu"
+                ", size = %" FORMAT_OFF_T
+                ", maxdownload = %" FORMAT_OFF_T
+                ", bytecount = %" FORMAT_OFF_T "\n",
+                excess, k->size, k->maxdownload, k->bytecount);
+          }
+        }
+
+        nread = (ssize_t) (k->maxdownload - k->bytecount);
+        if(nread < 0 ) /* this should be unusual */
+          nread = 0;
+
+        k->keepon &= ~KEEP_RECV; /* we're done reading */
+      }
+
+      k->bytecount += nread;
+
+      Curl_pgrsSetDownloadCounter(data, k->bytecount);
+
+      if(!k->chunk && (nread || k->badheader || is_empty_data)) {
+        /* If this is chunky transfer, it was already written */
+
+        if(k->badheader && !k->ignorebody) {
+          /* we parsed a piece of data wrongly assuming it was a header
+             and now we output it as body instead */
+
+          /* Don't let excess data pollute body writes */
+          if(k->maxdownload == -1 || (curl_off_t)k->hbuflen <= k->maxdownload)
+            result = Curl_client_write(conn, CLIENTWRITE_BODY,
+                data->state.headerbuff,
+                k->hbuflen);
+          else
+            result = Curl_client_write(conn, CLIENTWRITE_BODY,
+                data->state.headerbuff,
+                (size_t)k->maxdownload);
+
+          if(result)
+            return result;
+        }
+        if(k->badheader < HEADER_ALLBAD) {
+          /* This switch handles various content encodings. If there's an
+             error here, be sure to check over the almost identical code
+             in http_chunks.c.
+             Make sure that ALL_CONTENT_ENCODINGS contains all the
+             encodings handled here. */
+#ifdef HAVE_LIBZ
+          switch (conn->data->set.http_ce_skip ?
+                  IDENTITY : k->content_encoding) {
+          case IDENTITY:
+#endif
+            /* This is the default when the server sends no
+               Content-Encoding header. See Curl_readwrite_init; the
+               memset() call initializes k->content_encoding to zero. */
+            if(!k->ignorebody) {
+
+#ifndef CURL_DISABLE_POP3
+              if(conn->protocol&PROT_POP3)
+                result = Curl_pop3_write(conn, k->str, nread);
+              else
+#endif /* CURL_DISABLE_POP3 */
+
+              result = Curl_client_write(conn, CLIENTWRITE_BODY, k->str,
+                                         nread);
+            }
+#ifdef HAVE_LIBZ
+            break;
+
+          case DEFLATE:
+            /* Assume CLIENTWRITE_BODY; headers are not encoded. */
+            if(!k->ignorebody)
+              result = Curl_unencode_deflate_write(conn, k, nread);
+            break;
+
+          case GZIP:
+            /* Assume CLIENTWRITE_BODY; headers are not encoded. */
+            if(!k->ignorebody)
+              result = Curl_unencode_gzip_write(conn, k, nread);
+            break;
+
+          case COMPRESS:
+          default:
+            failf (data, "Unrecognized content encoding type. "
+                   "libcurl understands `identity', `deflate' and `gzip' "
+                   "content encodings.");
+            result = CURLE_BAD_CONTENT_ENCODING;
+            break;
+          }
+#endif
+        }
+        k->badheader = HEADER_NORMAL; /* taken care of now */
+
+        if(result)
+          return result;
+      }
+
+    } /* if(! header and data to read ) */
+
+#ifndef CURL_DISABLE_RTSP
+    if(excess > 0 && !conn->bits.stream_was_rewound &&
+        (conn->protocol & PROT_RTSP)) {
+      /* Check for RTP after the content if there is unrewound excess */
+
+      /* Parse the excess data */
+      k->str += nread;
+      nread = excess;
+
+      result = Curl_rtsp_rtp_readwrite(data, conn, &nread, &readmore);
+      if(result)
+        return result;
+
+      if(readmore)
+        k->keepon |= KEEP_RECV; /* we're not done reading */
+        break;
+    }
+#endif
+
+    if(is_empty_data) {
+      /* if we received nothing, the server closed the connection and we
+         are done */
+      k->keepon &= ~KEEP_RECV;
+    }
+
+  } while(data_pending(conn));
+
+  if(((k->keepon & (KEEP_RECV|KEEP_SEND)) == KEEP_SEND) &&
+     conn->bits.close ) {
+    /* When we've read the entire thing and the close bit is set, the server
+       may now close the connection. If there's now any kind of sending going
+       on from our side, we need to stop that immediately. */
+    infof(data, "we are done reading and this is set to close, stop send\n");
+    k->keepon &= ~KEEP_SEND; /* no writing anymore either */
+  }
+
+  return CURLE_OK;
+}
+
+/*
+ * Send data to upload to the server, when the socket is writable.
+ */
+static CURLcode readwrite_upload(struct SessionHandle *data,
+                                 struct connectdata *conn,
+                                 struct SingleRequest *k,
+                                 int *didwhat)
+{
+  ssize_t i, si;
+  ssize_t bytes_written;
+  CURLcode result;
+  ssize_t nread; /* number of bytes read */
+  bool sending_http_headers = FALSE;
+
+  if((k->bytecount == 0) && (k->writebytecount == 0))
+    Curl_pgrsTime(data, TIMER_STARTTRANSFER);
+
+  *didwhat |= KEEP_SEND;
+
+  /*
+   * We loop here to do the READ and SEND loop until we run out of
+   * data to send or until we get EWOULDBLOCK back
+   */
+  do {
+
+    /* only read more data if there's no upload data already
+       present in the upload buffer */
+    if(0 == data->req.upload_present) {
+      /* init the "upload from here" pointer */
+      data->req.upload_fromhere = k->uploadbuf;
+
+      if(!k->upload_done) {
+        /* HTTP pollution, this should be written nicer to become more
+           protocol agnostic. */
+        int fillcount;
+
+        if((k->exp100 == EXP100_SENDING_REQUEST) &&
+           (data->state.proto.http->sending == HTTPSEND_BODY)) {
+          /* If this call is to send body data, we must take some action:
+             We have sent off the full HTTP 1.1 request, and we shall now
+             go into the Expect: 100 state and await such a header */
+          k->exp100 = EXP100_AWAITING_CONTINUE; /* wait for the header */
+          k->keepon &= ~KEEP_SEND;         /* disable writing */
+          k->start100 = Curl_tvnow();       /* timeout count starts now */
+          *didwhat &= ~KEEP_SEND;  /* we didn't write anything actually */
+          break;
+        }
+
+        if(conn->protocol&(PROT_HTTP|PROT_RTSP)) {
+          if(data->state.proto.http->sending == HTTPSEND_REQUEST)
+            /* We're sending the HTTP request headers, not the data.
+               Remember that so we don't change the line endings. */
+            sending_http_headers = TRUE;
+          else
+            sending_http_headers = FALSE;
+        }
+
+        result = Curl_fillreadbuffer(conn, BUFSIZE, &fillcount);
+        if(result)
+          return result;
+
+        nread = (ssize_t)fillcount;
+      }
+      else
+        nread = 0; /* we're done uploading/reading */
+
+      if(!nread && (k->keepon & KEEP_SEND_PAUSE)) {
+        /* this is a paused transfer */
+        break;
+      }
+      else if(nread<=0) {
+        /* done */
+        k->keepon &= ~KEEP_SEND; /* we're done writing */
+
+        if(conn->bits.rewindaftersend) {
+          result = Curl_readrewind(conn);
+          if(result)
+            return result;
+        }
+        break;
+      }
+
+      /* store number of bytes available for upload */
+      data->req.upload_present = nread;
+
+#ifndef CURL_DISABLE_SMTP
+      if(conn->protocol & PROT_SMTP) {
+        result = Curl_smtp_escape_eob(conn, nread);
+        if(result)
+          return result;
+      }
+      else
+#endif /* CURL_DISABLE_SMTP */
+
+      /* convert LF to CRLF if so asked */
+      if((!sending_http_headers) &&
+#ifdef CURL_DO_LINEEND_CONV
+        /* always convert if we're FTPing in ASCII mode */
+         ((data->set.crlf) || (data->set.prefer_ascii))) {
+#else
+         (data->set.crlf)) {
+#endif
+        if(data->state.scratch == NULL)
+          data->state.scratch = malloc(2*BUFSIZE);
+        if(data->state.scratch == NULL) {
+          failf (data, "Failed to alloc scratch buffer!");
+          return CURLE_OUT_OF_MEMORY;
+        }
+        /*
+         * ASCII/EBCDIC Note: This is presumably a text (not binary)
+         * transfer so the data should already be in ASCII.
+         * That means the hex values for ASCII CR (0x0d) & LF (0x0a)
+         * must be used instead of the escape sequences \r & \n.
+         */
+        for(i = 0, si = 0; i < nread; i++, si++) {
+          if(data->req.upload_fromhere[i] == 0x0a) {
+            data->state.scratch[si++] = 0x0d;
+            data->state.scratch[si] = 0x0a;
+            if(!data->set.crlf) {
+              /* we're here only because FTP is in ASCII mode...
+                 bump infilesize for the LF we just added */
+              data->set.infilesize++;
+            }
+          }
+          else
+            data->state.scratch[si] = data->req.upload_fromhere[i];
+        }
+        if(si != nread) {
+          /* only perform the special operation if we really did replace
+             anything */
+          nread = si;
+
+          /* upload from the new (replaced) buffer instead */
+          data->req.upload_fromhere = data->state.scratch;
+
+          /* set the new amount too */
+          data->req.upload_present = nread;
+        }
+      }
+    } /* if 0 == data->req.upload_present */
+    else {
+      /* We have a partial buffer left from a previous "round". Use
+         that instead of reading more data */
+    }
+
+    /* write to socket (send away data) */
+    result = Curl_write(conn,
+                        conn->writesockfd,     /* socket to send to */
+                        data->req.upload_fromhere, /* buffer pointer */
+                        data->req.upload_present,  /* buffer size */
+                        &bytes_written);           /* actually sent */
+
+    if(result)
+      return result;
+
+    if(data->set.verbose)
+      /* show the data before we change the pointer upload_fromhere */
+      Curl_debug(data, CURLINFO_DATA_OUT, data->req.upload_fromhere,
+                 (size_t)bytes_written, conn);
+
+    if(data->req.upload_present != bytes_written) {
+      /* we only wrote a part of the buffer (if anything), deal with it! */
+
+      /* store the amount of bytes left in the buffer to write */
+      data->req.upload_present -= bytes_written;
+
+      /* advance the pointer where to find the buffer when the next send
+         is to happen */
+      data->req.upload_fromhere += bytes_written;
+    }
+    else {
+      /* we've uploaded that buffer now */
+      data->req.upload_fromhere = k->uploadbuf;
+      data->req.upload_present = 0; /* no more bytes left */
+
+      if(k->upload_done) {
+        /* switch off writing, we're done! */
+        k->keepon &= ~KEEP_SEND; /* we're done writing */
+      }
+    }
+
+    k->writebytecount += bytes_written;
+    Curl_pgrsSetUploadCounter(data, k->writebytecount);
+
+  } while(0); /* just to break out from! */
+
+  return CURLE_OK;
+}
+
+/*
+ * Curl_readwrite() is the low-level function to be called when data is to
+ * be read and written to/from the connection.
+ */
+CURLcode Curl_readwrite(struct connectdata *conn,
+                        bool *done)
+{
+  struct SessionHandle *data = conn->data;
+  struct SingleRequest *k = &data->req;
+  CURLcode result;
+  int didwhat=0;
+
+  curl_socket_t fd_read;
+  curl_socket_t fd_write;
+  int select_res = conn->cselect_bits;
+
+  conn->cselect_bits = 0;
+
+  /* only use the proper socket if the *_HOLD bit is not set simultaneously as
+     then we are in rate limiting state in that transfer direction */
+
+  if((k->keepon & KEEP_RECVBITS) == KEEP_RECV)
+    fd_read = conn->sockfd;
+  else
+    fd_read = CURL_SOCKET_BAD;
+
+  if((k->keepon & KEEP_SENDBITS) == KEEP_SEND)
+    fd_write = conn->writesockfd;
+  else
+    fd_write = CURL_SOCKET_BAD;
+
+  if(!select_res) /* Call for select()/poll() only, if read/write/error
+                     status is not known. */
+    select_res = Curl_socket_ready(fd_read, fd_write, 0);
+
+  if(select_res == CURL_CSELECT_ERR) {
+    failf(data, "select/poll returned error");
+    return CURLE_SEND_ERROR;
+  }
+
+  /* We go ahead and do a read if we have a readable socket or if
+     the stream was rewound (in which case we have data in a
+     buffer) */
+  if((k->keepon & KEEP_RECV) &&
+     ((select_res & CURL_CSELECT_IN) || conn->bits.stream_was_rewound)) {
+
+    result = readwrite_data(data, conn, k, &didwhat, done);
+    if(result || *done)
+      return result;
+  }
+
+  /* If we still have writing to do, we check if we have a writable socket. */
+  if((k->keepon & KEEP_SEND) && (select_res & CURL_CSELECT_OUT)) {
+    /* write */
+
+    result = readwrite_upload(data, conn, k, &didwhat);
+    if(result)
+      return result;
+  }
+
+  k->now = Curl_tvnow();
+  if(didwhat) {
+    /* Update read/write counters */
+    if(k->bytecountp)
+      *k->bytecountp = k->bytecount; /* read count */
+    if(k->writebytecountp)
+      *k->writebytecountp = k->writebytecount; /* write count */
+  }
+  else {
+    /* no read no write, this is a timeout? */
+    if(k->exp100 == EXP100_AWAITING_CONTINUE) {
+      /* This should allow some time for the header to arrive, but only a
+         very short time as otherwise it'll be too much wasted time too
+         often. */
+
+      /* Quoting RFC2616, section "8.2.3 Use of the 100 (Continue) Status":
+
+         Therefore, when a client sends this header field to an origin server
+         (possibly via a proxy) from which it has never seen a 100 (Continue)
+         status, the client SHOULD NOT wait for an indefinite period before
+         sending the request body.
+
+      */
+
+      long ms = Curl_tvdiff(k->now, k->start100);
+      if(ms > CURL_TIMEOUT_EXPECT_100) {
+        /* we've waited long enough, continue anyway */
+        k->exp100 = EXP100_SEND_DATA;
+        k->keepon |= KEEP_SEND;
+        infof(data, "Done waiting for 100-continue\n");
+      }
+    }
+  }
+
+  if(Curl_pgrsUpdate(conn))
+    result = CURLE_ABORTED_BY_CALLBACK;
+  else
+    result = Curl_speedcheck(data, k->now);
+  if(result)
+    return result;
+
+  if(k->keepon) {
+    if(data->set.timeout &&
+       (Curl_tvdiff(k->now, k->start) >= data->set.timeout)) {
+      if(k->size != -1) {
+        failf(data, "Operation timed out after %ld milliseconds with %"
+              FORMAT_OFF_T " out of %" FORMAT_OFF_T " bytes received",
+              Curl_tvdiff(k->now, k->start), k->bytecount, k->size);
+      } else {
+        failf(data, "Operation timed out after %ld milliseconds with %"
+              FORMAT_OFF_T " bytes received",
+              Curl_tvdiff(k->now, k->start), k->bytecount);
+      }
+      return CURLE_OPERATION_TIMEDOUT;
+    }
+  }
+  else {
+    /*
+     * The transfer has been performed. Just make some general checks before
+     * returning.
+     */
+
+    if(!(data->set.opt_no_body) && (k->size != -1) &&
+       (k->bytecount != k->size) &&
+#ifdef CURL_DO_LINEEND_CONV
+       /* Most FTP servers don't adjust their file SIZE response for CRLFs,
+          so we'll check to see if the discrepancy can be explained
+          by the number of CRLFs we've changed to LFs.
+       */
+       (k->bytecount != (k->size + data->state.crlf_conversions)) &&
+#endif /* CURL_DO_LINEEND_CONV */
+       !data->req.newurl) {
+      failf(data, "transfer closed with %" FORMAT_OFF_T
+            " bytes remaining to read",
+            k->size - k->bytecount);
+      return CURLE_PARTIAL_FILE;
+    }
+    else if(!(data->set.opt_no_body) &&
+            k->chunk &&
+            (conn->chunk.state != CHUNK_STOP)) {
+      /*
+       * In chunked mode, return an error if the connection is closed prior to
+       * the empty (terminiating) chunk is read.
+       *
+       * The condition above used to check for
+       * conn->proto.http->chunk.datasize != 0 which is true after reading
+       * *any* chunk, not just the empty chunk.
+       *
+       */
+      failf(data, "transfer closed with outstanding read data remaining");
+      return CURLE_PARTIAL_FILE;
+    }
+    if(Curl_pgrsUpdate(conn))
+      return CURLE_ABORTED_BY_CALLBACK;
+  }
+
+  /* Now update the "done" boolean we return */
+  *done = (bool)(0 == (k->keepon&(KEEP_RECV|KEEP_SEND|
+                                  KEEP_RECV_PAUSE|KEEP_SEND_PAUSE)));
+
+  return CURLE_OK;
+}
+
+/*
+ * Curl_single_getsock() gets called by the multi interface code when the app
+ * has requested to get the sockets for the current connection. This function
+ * will then be called once for every connection that the multi interface
+ * keeps track of. This function will only be called for connections that are
+ * in the proper state to have this information available.
+ */
+int Curl_single_getsock(const struct connectdata *conn,
+                        curl_socket_t *sock, /* points to numsocks number
+                                                of sockets */
+                        int numsocks)
+{
+  const struct SessionHandle *data = conn->data;
+  int bitmap = GETSOCK_BLANK;
+  unsigned sockindex = 0;
+
+  if(conn->handler->perform_getsock)
+    return conn->handler->perform_getsock(conn, sock, numsocks);
+
+  if(numsocks < 2)
+    /* simple check but we might need two slots */
+    return GETSOCK_BLANK;
+
+  /* don't include HOLD and PAUSE connections */
+  if((data->req.keepon & KEEP_RECVBITS) == KEEP_RECV) {
+
+    DEBUGASSERT(conn->sockfd != CURL_SOCKET_BAD);
+
+    bitmap |= GETSOCK_READSOCK(sockindex);
+    sock[sockindex] = conn->sockfd;
+  }
+
+  /* don't include HOLD and PAUSE connections */
+  if((data->req.keepon & KEEP_SENDBITS) == KEEP_SEND) {
+
+    if((conn->sockfd != conn->writesockfd) ||
+       !(data->req.keepon & KEEP_RECV)) {
+      /* only if they are not the same socket or we didn't have a readable
+         one, we increase index */
+      if(data->req.keepon & KEEP_RECV)
+        sockindex++; /* increase index if we need two entries */
+
+      DEBUGASSERT(conn->writesockfd != CURL_SOCKET_BAD);
+
+      sock[sockindex] = conn->writesockfd;
+    }
+
+    bitmap |= GETSOCK_WRITESOCK(sockindex);
+  }
+
+  return bitmap;
+}
+
+/*
+ * Determine optimum sleep time based on configured rate, current rate,
+ * and packet size.
+ * Returns value in mili-seconds.
+ *
+ * The basic idea is to adjust the desired rate up/down in this method
+ * based on whether we are running too slow or too fast.  Then, calculate
+ * how many miliseconds to wait for the next packet to achieve this new
+ * rate.
+ */
+long Curl_sleep_time(curl_off_t rate_bps, curl_off_t cur_rate_bps,
+                             int pkt_size)
+{
+  curl_off_t min_sleep = 0;
+  curl_off_t rv = 0;
+
+  if (rate_bps == 0)
+    return 0;
+
+  /* If running faster than about .1% of the desired speed, slow
+   * us down a bit.  Use shift instead of division as the 0.1%
+   * cutoff is arbitrary anyway.
+   */
+  if (cur_rate_bps > (rate_bps + (rate_bps >> 10))) {
+    /* running too fast, decrease target rate by 1/64th of rate */
+    rate_bps -= rate_bps >> 6;
+    min_sleep = 1;
+  }
+  else if (cur_rate_bps < (rate_bps - (rate_bps >> 10))) {
+    /* running too slow, increase target rate by 1/64th of rate */
+    rate_bps += rate_bps >> 6;
+  }
+
+  /* Determine number of miliseconds to wait until we do
+   * the next packet at the adjusted rate.  We should wait
+   * longer when using larger packets, for instance.
+   */
+  rv = ((curl_off_t)((pkt_size * 8) * 1000) / rate_bps);
+
+  /* Catch rounding errors and always slow down at least 1ms if
+   * we are running too fast.
+   */
+  if (rv < min_sleep)
+    rv = min_sleep;
+
+  /* Bound value to fit in 'long' on 32-bit platform.  That's
+   * plenty long enough anyway!
+   */
+  if(rv > 0x7fffffff)
+    rv = 0x7fffffff;
+  
+  return (long)rv;
+}
+
+
+/*
+ * Transfer()
+ *
+ * This function is what performs the actual transfer. It is capable of doing
+ * both ways simultaneously.  The transfer must already have been setup by a
+ * call to Curl_setup_transfer().
+ *
+ * Note that headers are created in a preallocated buffer of a default size.
+ * That buffer can be enlarged on demand, but it is never shrunken again.
+ *
+ */
+
+static CURLcode
+Transfer(struct connectdata *conn)
+{
+  CURLcode result;
+  struct SessionHandle *data = conn->data;
+  struct SingleRequest *k = &data->req;
+  bool done=FALSE;
+  bool first=TRUE;
+  int timeout_ms;
+  int buffersize;
+  int totmp;
+
+  if((conn->sockfd == CURL_SOCKET_BAD) &&
+     (conn->writesockfd == CURL_SOCKET_BAD))
+    /* nothing to read, nothing to write, we're already OK! */
+    return CURLE_OK;
+
+  /* we want header and/or body, if neither then don't do this! */
+  if(!k->getheader && data->set.opt_no_body)
+    return CURLE_OK;
+
+  while(!done) {
+    curl_socket_t fd_read = conn->sockfd;
+    curl_socket_t fd_write = conn->writesockfd;
+    int keepon = k->keepon;
+    timeout_ms = 1000;
+
+    if(conn->waitfor) {
+      /* if waitfor is set, get the RECV and SEND bits from that but keep the
+         other bits */
+      keepon &= ~ (KEEP_RECV|KEEP_SEND);
+      keepon |= conn->waitfor & (KEEP_RECV|KEEP_SEND);
+    }
+
+    /* limit-rate logic: if speed exceeds threshold, then do not include fd in
+       select set. The current speed is recalculated in each Curl_readwrite()
+       call */
+    if((keepon & KEEP_SEND) &&
+        (!data->set.max_send_speed ||
+         (data->progress.ulspeed < data->set.max_send_speed) )) {
+      k->keepon &= ~KEEP_SEND_HOLD;
+    }
+    else {
+      if (data->set.upload && data->set.max_send_speed &&
+          (data->progress.ulspeed > data->set.max_send_speed) ) {
+        /* calculate upload rate-limitation timeout. */
+        buffersize = (int)(data->set.buffer_size ?
+                           data->set.buffer_size : BUFSIZE);
+        totmp = (int)Curl_sleep_time(data->set.max_send_speed,
+                                     data->progress.ulspeed, buffersize);
+        if (totmp < timeout_ms)
+          timeout_ms = totmp;
+      }
+      fd_write = CURL_SOCKET_BAD;
+      if(keepon & KEEP_SEND)
+        k->keepon |= KEEP_SEND_HOLD; /* hold it */
+    }
+
+    if((keepon & KEEP_RECV) &&
+        (!data->set.max_recv_speed ||
+         (data->progress.dlspeed < data->set.max_recv_speed)) ) {
+      k->keepon &= ~KEEP_RECV_HOLD;
+    }
+    else {
+      if ((!data->set.upload) && data->set.max_recv_speed &&
+          (data->progress.dlspeed > data->set.max_recv_speed)) {
+        /* Calculate download rate-limitation timeout. */
+        buffersize = (int)(data->set.buffer_size ?
+                           data->set.buffer_size : BUFSIZE);
+        totmp = (int)Curl_sleep_time(data->set.max_recv_speed,
+                                     data->progress.dlspeed, buffersize);
+        if (totmp < timeout_ms)
+          timeout_ms = totmp;
+      }
+      fd_read = CURL_SOCKET_BAD;
+      if(keepon & KEEP_RECV)
+        k->keepon |= KEEP_RECV_HOLD; /* hold it */
+    }
+
+    /* pause logic. Don't check descriptors for paused connections */
+    if(k->keepon & KEEP_RECV_PAUSE)
+      fd_read = CURL_SOCKET_BAD;
+    if(k->keepon & KEEP_SEND_PAUSE)
+      fd_write = CURL_SOCKET_BAD;
+
+    /* The *_HOLD and *_PAUSE logic is necessary since even though there might
+       be no traffic during the select interval, we still call
+       Curl_readwrite() for the timeout case and if we limit transfer speed we
+       must make sure that this function doesn't transfer anything while in
+       HOLD status.
+
+       The no timeout for the first round is for the protocols for which data
+       has already been slurped off the socket and thus waiting for action
+       won't work since it'll wait even though there is already data present
+       to work with. */
+    if(first &&
+       ((fd_read != CURL_SOCKET_BAD) || (fd_write != CURL_SOCKET_BAD)))
+      /* if this is the first lap and one of the file descriptors is fine
+         to work with, skip the timeout */
+      timeout_ms = 0;
+    else {
+      if(data->set.timeout) {
+        totmp = (int)(data->set.timeout - Curl_tvdiff(k->now, k->start));
+        if(totmp < 0)
+          return CURLE_OPERATION_TIMEDOUT;
+      }
+      else
+        totmp = 1000;
+
+      if (totmp < timeout_ms)
+        timeout_ms = totmp;
+    }
+
+    switch (Curl_socket_ready(fd_read, fd_write, timeout_ms)) {
+    case -1: /* select() error, stop reading */
+#ifdef EINTR
+      /* The EINTR is not serious, and it seems you might get this more
+         often when using the lib in a multi-threaded environment! */
+      if(SOCKERRNO == EINTR)
+        continue;
+#endif
+      return CURLE_RECV_ERROR;  /* indicate a network problem */
+    case 0:  /* timeout */
+    default: /* readable descriptors */
+
+      result = Curl_readwrite(conn, &done);
+      /* "done" signals to us if the transfer(s) are ready */
+      break;
+    }
+    if(result)
+      return result;
+
+    first = FALSE; /* not the first lap anymore */
+  }
+
+  return CURLE_OK;
+}
+
+/*
+ * Curl_pretransfer() is called immediately before a transfer starts.
+ */
+CURLcode Curl_pretransfer(struct SessionHandle *data)
+{
+  CURLcode res;
+  if(!data->change.url) {
+    /* we can't do anything without URL */
+    failf(data, "No URL set!");
+    return CURLE_URL_MALFORMAT;
+  }
+
+  /* Init the SSL session ID cache here. We do it here since we want to do it
+     after the *_setopt() calls (that could change the size of the cache) but
+     before any transfer takes place. */
+  res = Curl_ssl_initsessions(data, data->set.ssl.numsessions);
+  if(res)
+    return res;
+
+  data->set.followlocation=0; /* reset the location-follow counter */
+  data->state.this_is_a_follow = FALSE; /* reset this */
+  data->state.errorbuf = FALSE; /* no error has occurred */
+  data->state.httpversion = 0; /* don't assume any particular server version */
+
+  data->state.ssl_connect_retry = FALSE;
+
+  data->state.authproblem = FALSE;
+  data->state.authhost.want = data->set.httpauth;
+  data->state.authproxy.want = data->set.proxyauth;
+  Curl_safefree(data->info.wouldredirect);
+  data->info.wouldredirect = NULL;
+
+  /* If there is a list of cookie files to read, do it now! */
+  if(data->change.cookielist) {
+    Curl_cookie_loadfiles(data);
+  }
+
+ /* Allow data->set.use_port to set which port to use. This needs to be
+  * disabled for example when we follow Location: headers to URLs using
+  * different ports! */
+  data->state.allow_port = TRUE;
+
+#if defined(HAVE_SIGNAL) && defined(SIGPIPE) && !defined(HAVE_MSG_NOSIGNAL)
+  /*************************************************************
+   * Tell signal handler to ignore SIGPIPE
+   *************************************************************/
+  if(!data->set.no_signal)
+    data->state.prev_signal = signal(SIGPIPE, SIG_IGN);
+#endif
+
+  Curl_initinfo(data); /* reset session-specific information "variables" */
+  Curl_pgrsStartNow(data);
+
+  return CURLE_OK;
+}
+
+/*
+ * Curl_posttransfer() is called immediately after a transfer ends
+ */
+CURLcode Curl_posttransfer(struct SessionHandle *data)
+{
+#if defined(HAVE_SIGNAL) && defined(SIGPIPE) && !defined(HAVE_MSG_NOSIGNAL)
+  /* restore the signal handler for SIGPIPE before we get back */
+  if(!data->set.no_signal)
+    signal(SIGPIPE, data->state.prev_signal);
+#else
+  (void)data; /* unused parameter */
+#endif
+
+  if(!(data->progress.flags & PGRS_HIDE) &&
+     !data->progress.callback)
+    /* only output if we don't use a progress callback and we're not hidden */
+    fprintf(data->set.err, "\n");
+
+  return CURLE_OK;
+}
+
+#ifndef CURL_DISABLE_HTTP
+/*
+ * strlen_url() returns the length of the given URL if the spaces within the
+ * URL were properly URL encoded.
+ */
+static size_t strlen_url(const char *url)
+{
+  const char *ptr;
+  size_t newlen=0;
+  bool left=TRUE; /* left side of the ? */
+
+  for(ptr=url; *ptr; ptr++) {
+    switch(*ptr) {
+    case '?':
+      left=FALSE;
+      /* fall through */
+    default:
+      newlen++;
+      break;
+    case ' ':
+      if(left)
+        newlen+=3;
+      else
+        newlen++;
+      break;
+    }
+  }
+  return newlen;
+}
+
+/* strcpy_url() copies a url to a output buffer and URL-encodes the spaces in
+ * the source URL accordingly.
+ */
+static void strcpy_url(char *output, const char *url)
+{
+  /* we must add this with whitespace-replacing */
+  bool left=TRUE;
+  const char *iptr;
+  char *optr = output;
+  for(iptr = url;    /* read from here */
+      *iptr;         /* until zero byte */
+      iptr++) {
+    switch(*iptr) {
+    case '?':
+      left=FALSE;
+      /* fall through */
+    default:
+      *optr++=*iptr;
+      break;
+    case ' ':
+      if(left) {
+        *optr++='%'; /* add a '%' */
+        *optr++='2'; /* add a '2' */
+        *optr++='0'; /* add a '0' */
+      }
+      else
+        *optr++='+'; /* add a '+' here */
+      break;
+    }
+  }
+  *optr=0; /* zero terminate output buffer */
+
+}
+
+/*
+ * Returns true if the given URL is absolute (as opposed to relative)
+ */
+static bool is_absolute_url(const char *url)
+{
+  char prot[16]; /* URL protocol string storage */
+  char letter;   /* used for a silly sscanf */
+
+  return (bool)(2 == sscanf(url, "%15[^?&/:]://%c", prot, &letter));
+}
+
+/*
+ * Concatenate a relative URL to a base URL making it absolute.
+ * URL-encodes any spaces.
+ * The returned pointer must be freed by the caller unless NULL
+ * (returns NULL on out of memory).
+ */
+static char *concat_url(const char *base, const char *relurl)
+{
+  /***
+   TRY to append this new path to the old URL
+   to the right of the host part. Oh crap, this is doomed to cause
+   problems in the future...
+  */
+  char *newest;
+  char *protsep;
+  char *pathsep;
+  size_t newlen;
+
+  const char *useurl = relurl;
+  size_t urllen;
+
+  /* we must make our own copy of the URL to play with, as it may
+     point to read-only data */
+  char *url_clone=strdup(base);
+
+  if(!url_clone)
+    return NULL; /* skip out of this NOW */
+
+  /* protsep points to the start of the host name */
+  protsep=strstr(url_clone, "//");
+  if(!protsep)
+    protsep=url_clone;
+  else
+    protsep+=2; /* pass the slashes */
+
+  if('/' != relurl[0]) {
+    int level=0;
+
+    /* First we need to find out if there's a ?-letter in the URL,
+       and cut it and the right-side of that off */
+    pathsep = strchr(protsep, '?');
+    if(pathsep)
+      *pathsep=0;
+
+    /* we have a relative path to append to the last slash if there's one
+       available, or if the new URL is just a query string (starts with a
+       '?')  we append the new one at the end of the entire currently worked
+       out URL */
+    if(useurl[0] != '?') {
+      pathsep = strrchr(protsep, '/');
+      if(pathsep)
+        *pathsep=0;
+    }
+
+    /* Check if there's any slash after the host name, and if so, remember
+       that position instead */
+    pathsep = strchr(protsep, '/');
+    if(pathsep)
+      protsep = pathsep+1;
+    else
+      protsep = NULL;
+
+    /* now deal with one "./" or any amount of "../" in the newurl
+       and act accordingly */
+
+    if((useurl[0] == '.') && (useurl[1] == '/'))
+      useurl+=2; /* just skip the "./" */
+
+    while((useurl[0] == '.') &&
+          (useurl[1] == '.') &&
+          (useurl[2] == '/')) {
+      level++;
+      useurl+=3; /* pass the "../" */
+    }
+
+    if(protsep) {
+      while(level--) {
+        /* cut off one more level from the right of the original URL */
+        pathsep = strrchr(protsep, '/');
+        if(pathsep)
+          *pathsep=0;
+        else {
+          *protsep=0;
+          break;
+        }
+      }
+    }
+  }
+  else {
+    /* We got a new absolute path for this server, cut off from the
+       first slash */
+    pathsep = strchr(protsep, '/');
+    if(pathsep) {
+      /* When people use badly formatted URLs, such as
+         "http://www.url.com?dir=/home/daniel" we must not use the first
+         slash, if there's a ?-letter before it! */
+      char *sep = strchr(protsep, '?');
+      if(sep && (sep < pathsep))
+        pathsep = sep;
+      *pathsep=0;
+    }
+    else {
+      /* There was no slash. Now, since we might be operating on a badly
+         formatted URL, such as "http://www.url.com?id=2380" which doesn't
+         use a slash separator as it is supposed to, we need to check for a
+         ?-letter as well! */
+      pathsep = strchr(protsep, '?');
+      if(pathsep)
+        *pathsep=0;
+    }
+  }
+
+  /* If the new part contains a space, this is a mighty stupid redirect
+     but we still make an effort to do "right". To the left of a '?'
+     letter we replace each space with %20 while it is replaced with '+'
+     on the right side of the '?' letter.
+  */
+  newlen = strlen_url(useurl);
+
+  urllen = strlen(url_clone);
+
+  newest = malloc( urllen + 1 + /* possible slash */
+                         newlen + 1 /* zero byte */);
+
+  if(!newest) {
+    free(url_clone); /* don't leak this */
+    return NULL;
+  }
+
+  /* copy over the root url part */
+  memcpy(newest, url_clone, urllen);
+
+  /* check if we need to append a slash */
+  if(('/' == useurl[0]) || (protsep && !*protsep) || ('?' == useurl[0]))
+    ;
+  else
+    newest[urllen++]='/';
+
+  /* then append the new piece on the right side */
+  strcpy_url(&newest[urllen], useurl);
+
+  free(url_clone);
+
+  return newest;
+}
+#endif /* CURL_DISABLE_HTTP */
+
+/*
+ * Curl_follow() handles the URL redirect magic. Pass in the 'newurl' string
+ * as given by the remote server and set up the new URL to request.
+ */
+CURLcode Curl_follow(struct SessionHandle *data,
+                     char *newurl, /* this 'newurl' is the Location: string,
+                                      and it must be malloc()ed before passed
+                                      here */
+                     followtype type) /* see transfer.h */
+{
+#ifdef CURL_DISABLE_HTTP
+  (void)data;
+  (void)newurl;
+  (void)type;
+  /* Location: following will not happen when HTTP is disabled */
+  return CURLE_TOO_MANY_REDIRECTS;
+#else
+
+  /* Location: redirect */
+  bool disallowport = FALSE;
+
+  if(type == FOLLOW_REDIR) {
+    if((data->set.maxredirs != -1) &&
+        (data->set.followlocation >= data->set.maxredirs)) {
+      failf(data,"Maximum (%ld) redirects followed", data->set.maxredirs);
+      return CURLE_TOO_MANY_REDIRECTS;
+    }
+
+    /* mark the next request as a followed location: */
+    data->state.this_is_a_follow = TRUE;
+
+    data->set.followlocation++; /* count location-followers */
+
+    if(data->set.http_auto_referer) {
+      /* We are asked to automatically set the previous URL as the referer
+         when we get the next URL. We pick the ->url field, which may or may
+         not be 100% correct */
+
+      if(data->change.referer_alloc)
+        /* If we already have an allocated referer, free this first */
+        free(data->change.referer);
+
+      data->change.referer = strdup(data->change.url);
+      if (!data->change.referer) {
+        data->change.referer_alloc = FALSE;
+        return CURLE_OUT_OF_MEMORY;
+      }
+      data->change.referer_alloc = TRUE; /* yes, free this later */
+    }
+  }
+
+  if(!is_absolute_url(newurl))  {
+    /***
+     *DANG* this is an RFC 2068 violation. The URL is supposed
+     to be absolute and this doesn't seem to be that!
+     */
+    char *absolute = concat_url(data->change.url, newurl);
+    if (!absolute)
+      return CURLE_OUT_OF_MEMORY;
+    free(newurl);
+    newurl = absolute;
+  }
+  else {
+    /* This is an absolute URL, don't allow the custom port number */
+    disallowport = TRUE;
+
+    if(strchr(newurl, ' ')) {
+      /* This new URL contains at least one space, this is a mighty stupid
+         redirect but we still make an effort to do "right". */
+      char *newest;
+      size_t newlen = strlen_url(newurl);
+
+      newest = malloc(newlen+1); /* get memory for this */
+      if (!newest)
+        return CURLE_OUT_OF_MEMORY;
+      strcpy_url(newest, newurl); /* create a space-free URL */
+
+      free(newurl); /* that was no good */
+      newurl = newest; /* use this instead now */
+    }
+
+  }
+
+  if(type == FOLLOW_FAKE) {
+    /* we're only figuring out the new url if we would've followed locations
+       but now we're done so we can get out! */
+    data->info.wouldredirect = newurl;
+    return CURLE_OK;
+  }
+
+  if(disallowport)
+    data->state.allow_port = FALSE;
+
+  if(data->change.url_alloc)
+    free(data->change.url);
+  else
+    data->change.url_alloc = TRUE; /* the URL is allocated */
+
+  data->change.url = newurl;
+  newurl = NULL; /* don't free! */
+
+  infof(data, "Issue another request to this URL: '%s'\n", data->change.url);
+
+  /*
+   * We get here when the HTTP code is 300-399 (and 401). We need to perform
+   * differently based on exactly what return code there was.
+   *
+   * News from 7.10.6: we can also get here on a 401 or 407, in case we act on
+   * a HTTP (proxy-) authentication scheme other than Basic.
+   */
+  switch(data->info.httpcode) {
+    /* 401 - Act on a WWW-Authenticate, we keep on moving and do the
+       Authorization: XXXX header in the HTTP request code snippet */
+    /* 407 - Act on a Proxy-Authenticate, we keep on moving and do the
+       Proxy-Authorization: XXXX header in the HTTP request code snippet */
+    /* 300 - Multiple Choices */
+    /* 306 - Not used */
+    /* 307 - Temporary Redirect */
+  default:  /* for all above (and the unknown ones) */
+    /* Some codes are explicitly mentioned since I've checked RFC2616 and they
+     * seem to be OK to POST to.
+     */
+    break;
+  case 301: /* Moved Permanently */
+    /* (quote from RFC2616, section 10.3.2):
+     *
+     * Note: When automatically redirecting a POST request after receiving a
+     * 301 status code, some existing HTTP/1.0 user agents will erroneously
+     * change it into a GET request.
+     *
+     * ----
+     *
+     * Warning: Because most of importants user agents do this obvious RFC2616
+     * violation, many webservers expect this misbehavior. So these servers
+     * often answers to a POST request with an error page.  To be sure that
+     * libcurl gets the page that most user agents would get, libcurl has to
+     * force GET.
+     *
+     * This behaviour can be overridden with CURLOPT_POSTREDIR.
+     */
+    if( (data->set.httpreq == HTTPREQ_POST
+         || data->set.httpreq == HTTPREQ_POST_FORM)
+        && !data->set.post301) {
+      infof(data,
+            "Violate RFC 2616/10.3.2 and switch from POST to GET\n");
+      data->set.httpreq = HTTPREQ_GET;
+    }
+    break;
+  case 302: /* Found */
+    /* (From 10.3.3)
+
+    Note: RFC 1945 and RFC 2068 specify that the client is not allowed
+    to change the method on the redirected request.  However, most
+    existing user agent implementations treat 302 as if it were a 303
+    response, performing a GET on the Location field-value regardless
+    of the original request method. The status codes 303 and 307 have
+    been added for servers that wish to make unambiguously clear which
+    kind of reaction is expected of the client.
+
+    (From 10.3.4)
+
+    Note: Many pre-HTTP/1.1 user agents do not understand the 303
+    status. When interoperability with such clients is a concern, the
+    302 status code may be used instead, since most user agents react
+    to a 302 response as described here for 303.
+
+    This behaviour can be overriden with CURLOPT_POSTREDIR
+    */
+    if( (data->set.httpreq == HTTPREQ_POST
+         || data->set.httpreq == HTTPREQ_POST_FORM)
+        && !data->set.post302) {
+      infof(data,
+            "Violate RFC 2616/10.3.3 and switch from POST to GET\n");
+      data->set.httpreq = HTTPREQ_GET;
+    }
+    break;
+
+  case 303: /* See Other */
+    /* Disable both types of POSTs, since doing a second POST when
+     * following isn't what anyone would want! */
+    if(data->set.httpreq != HTTPREQ_GET) {
+      data->set.httpreq = HTTPREQ_GET; /* enforce GET request */
+      infof(data, "Disables POST, goes with %s\n",
+            data->set.opt_no_body?"HEAD":"GET");
+    }
+    break;
+  case 304: /* Not Modified */
+    /* 304 means we did a conditional request and it was "Not modified".
+     * We shouldn't get any Location: header in this response!
+     */
+    break;
+  case 305: /* Use Proxy */
+    /* (quote from RFC2616, section 10.3.6):
+     * "The requested resource MUST be accessed through the proxy given
+     * by the Location field. The Location field gives the URI of the
+     * proxy.  The recipient is expected to repeat this single request
+     * via the proxy. 305 responses MUST only be generated by origin
+     * servers."
+     */
+    break;
+  }
+  Curl_pgrsTime(data, TIMER_REDIRECT);
+  Curl_pgrsResetTimes(data);
+
+  return CURLE_OK;
+#endif /* CURL_DISABLE_HTTP */
+}
+
+static CURLcode
+connect_host(struct SessionHandle *data,
+             struct connectdata **conn)
+{
+  CURLcode res = CURLE_OK;
+
+  bool async;
+  bool protocol_done=TRUE; /* will be TRUE always since this is only used
+                                within the easy interface */
+  Curl_pgrsTime(data, TIMER_STARTSINGLE);
+  res = Curl_connect(data, conn, &async, &protocol_done);
+
+  if((CURLE_OK == res) && async) {
+    /* Now, if async is TRUE here, we need to wait for the name
+       to resolve */
+    res = Curl_wait_for_resolv(*conn, NULL);
+    if(CURLE_OK == res)
+      /* Resolved, continue with the connection */
+      res = Curl_async_resolved(*conn, &protocol_done);
+    else
+      /* if we can't resolve, we kill this "connection" now */
+      (void)Curl_disconnect(*conn);
+  }
+
+  return res;
+}
+
+CURLcode
+Curl_reconnect_request(struct connectdata **connp)
+{
+  CURLcode result = CURLE_OK;
+  struct connectdata *conn = *connp;
+  struct SessionHandle *data = conn->data;
+
+  /* This was a re-use of a connection and we got a write error in the
+   * DO-phase. Then we DISCONNECT this connection and have another attempt to
+   * CONNECT and then DO again! The retry cannot possibly find another
+   * connection to re-use, since we only keep one possible connection for
+   * each.  */
+
+  infof(data, "Re-used connection seems dead, get a new one\n");
+
+  conn->bits.close = TRUE; /* enforce close of this connection */
+  result = Curl_done(&conn, result, FALSE); /* we are so done with this */
+
+  /* conn may no longer be a good pointer */
+
+  /*
+   * According to bug report #1330310. We need to check for CURLE_SEND_ERROR
+   * here as well. I figure this could happen when the request failed on a FTP
+   * connection and thus Curl_done() itself tried to use the connection
+   * (again). Slight Lack of feedback in the report, but I don't think this
+   * extra check can do much harm.
+   */
+  if((CURLE_OK == result) || (CURLE_SEND_ERROR == result)) {
+    bool async;
+    bool protocol_done = TRUE;
+
+    /* Now, redo the connect and get a new connection */
+    result = Curl_connect(data, connp, &async, &protocol_done);
+    if(CURLE_OK == result) {
+      /* We have connected or sent away a name resolve query fine */
+
+      conn = *connp; /* setup conn to again point to something nice */
+      if(async) {
+        /* Now, if async is TRUE here, we need to wait for the name
+           to resolve */
+        result = Curl_wait_for_resolv(conn, NULL);
+        if(result)
+          return result;
+
+        /* Resolved, continue with the connection */
+        result = Curl_async_resolved(conn, &protocol_done);
+        if(result)
+          return result;
+      }
+    }
+  }
+
+  return result;
+}
+
+/* Returns CURLE_OK *and* sets '*url' if a request retry is wanted.
+
+   NOTE: that the *url is malloc()ed. */
+CURLcode Curl_retry_request(struct connectdata *conn,
+                            char **url)
+{
+  struct SessionHandle *data = conn->data;
+
+  *url = NULL;
+
+  /* if we're talking upload, we can't do the checks below, unless the protocol
+     is HTTP as when uploading over HTTP we will still get a response */
+  if(data->set.upload && !(conn->protocol&(PROT_HTTP|PROT_RTSP)))
+    return CURLE_OK;
+
+  if(/* workaround for broken TLS servers */ data->state.ssl_connect_retry ||
+      ((data->req.bytecount +
+        data->req.headerbytecount == 0) &&
+        conn->bits.reuse &&
+        !data->set.opt_no_body &&
+        data->set.rtspreq != RTSPREQ_RECEIVE)) {
+    /* We got no data, we attempted to re-use a connection and yet we want a
+       "body". This might happen if the connection was left alive when we were
+       done using it before, but that was closed when we wanted to read from
+       it again. Bad luck. Retry the same request on a fresh connect! */
+    infof(conn->data, "Connection died, retrying a fresh connect\n");
+    *url = strdup(conn->data->change.url);
+    if(!*url)
+      return CURLE_OUT_OF_MEMORY;
+
+    conn->bits.close = TRUE; /* close this connection */
+    conn->bits.retry = TRUE; /* mark this as a connection we're about
+                                to retry. Marking it this way should
+                                prevent i.e HTTP transfers to return
+                                error just because nothing has been
+                                transfered! */
+  }
+  return CURLE_OK;
+}
+
+/*
+ * Curl_perform() is the internal high-level function that gets called by the
+ * external curl_easy_perform() function. It inits, performs and cleans up a
+ * single file transfer.
+ */
+CURLcode Curl_perform(struct SessionHandle *data)
+{
+  CURLcode res;
+  CURLcode res2;
+  struct connectdata *conn=NULL;
+  char *newurl = NULL; /* possibly a new URL to follow to! */
+  followtype follow = FOLLOW_NONE;
+
+  data->state.used_interface = Curl_if_easy;
+
+  res = Curl_pretransfer(data);
+  if(res)
+    return res;
+
+  /*
+   * It is important that there is NO 'return' from this function at any other
+   * place than falling down to the end of the function! This is because we
+   * have cleanup stuff that must be done before we get back, and that is only
+   * performed after this do-while loop.
+   */
+
+  for(;;) {
+    res = connect_host(data, &conn);   /* primary connection */
+
+    if(res == CURLE_OK) {
+      bool do_done;
+      if(data->set.connect_only) {
+        /* keep connection open for application to use the socket */
+        conn->bits.close = FALSE;
+        res = Curl_done(&conn, CURLE_OK, FALSE);
+        break;
+      }
+      res = Curl_do(&conn, &do_done);
+
+      if(res == CURLE_OK) {
+        res = Transfer(conn); /* now fetch that URL please */
+        if((res == CURLE_OK) || (res == CURLE_RECV_ERROR)) {
+          bool retry = FALSE;
+          CURLcode rc = Curl_retry_request(conn, &newurl);
+          if(rc)
+            res = rc;
+          else
+            retry = (bool)(newurl?TRUE:FALSE);
+
+          if(retry) {
+            res = CURLE_OK;
+            follow = FOLLOW_RETRY;
+            if (!newurl)
+              res = CURLE_OUT_OF_MEMORY;
+          }
+          else if (res == CURLE_OK) {
+            /*
+             * We must duplicate the new URL here as the connection data may
+             * be free()ed in the Curl_done() function. We prefer the newurl
+             * one since that's used for redirects or just further requests
+             * for retries or multi-stage HTTP auth methods etc.
+             */
+            if(data->req.newurl) {
+              follow = FOLLOW_REDIR;
+              newurl = strdup(data->req.newurl);
+              if (!newurl)
+                res = CURLE_OUT_OF_MEMORY;
+            }
+            else if(data->req.location) {
+              follow = FOLLOW_FAKE;
+              newurl = strdup(data->req.location);
+              if (!newurl)
+                res = CURLE_OUT_OF_MEMORY;
+            }
+          }
+
+          /* in the above cases where 'newurl' gets assigned, we have a fresh
+           * allocated memory pointed to */
+        }
+        if(res != CURLE_OK) {
+          /* The transfer phase returned error, we mark the connection to get
+           * closed to prevent being re-used. This is because we can't
+           * possibly know if the connection is in a good shape or not now. */
+          conn->bits.close = TRUE;
+
+          if(CURL_SOCKET_BAD != conn->sock[SECONDARYSOCKET]) {
+            /* if we failed anywhere, we must clean up the secondary socket if
+               it was used */
+            sclose(conn->sock[SECONDARYSOCKET]);
+            conn->sock[SECONDARYSOCKET] = CURL_SOCKET_BAD;
+          }
+        }
+
+        /* Always run Curl_done(), even if some of the previous calls
+           failed, but return the previous (original) error code */
+        res2 = Curl_done(&conn, res, FALSE);
+
+        if(CURLE_OK == res)
+          res = res2;
+      }
+      else if(conn)
+        /* Curl_do() failed, clean up left-overs in the done-call, but note
+           that at some cases the conn pointer is NULL when Curl_do() failed
+           and the connection cache is very small so only call Curl_done() if
+           conn is still "alive".
+        */
+        res2 = Curl_done(&conn, res, FALSE);
+
+      /*
+       * Important: 'conn' cannot be used here, since it may have been closed
+       * in 'Curl_done' or other functions.
+       */
+
+      if((res == CURLE_OK) && follow) {
+        res = Curl_follow(data, newurl, follow);
+        if(CURLE_OK == res) {
+          /* if things went fine, Curl_follow() freed or otherwise took
+             responsibility for the newurl pointer */
+          newurl = NULL;
+          if(follow >= FOLLOW_RETRY) {
+            follow = FOLLOW_NONE;
+            continue;
+          }
+          /* else we break out of the loop below */
+        }
+      }
+    }
+    break; /* it only reaches here when this shouldn't loop */
+
+  } /* loop if Location: */
+
+  if(newurl)
+    free(newurl);
+
+  if(res && !data->state.errorbuf) {
+    /*
+     * As an extra precaution: if no error string has been set and there was
+     * an error, use the strerror() string or if things are so bad that not
+     * even that is good, set a bad string that mentions the error code.
+     */
+    const char *str = curl_easy_strerror(res);
+    if(!str)
+      failf(data, "unspecified error %d", (int)res);
+    else
+      failf(data, "%s", str);
+  }
+
+  /* run post-transfer unconditionally, but don't clobber the return code if
+     we already have an error code recorder */
+  res2 = Curl_posttransfer(data);
+  if(!res && res2)
+    res = res2;
+
+  return res;
+}
+
+/*
+ * Curl_setup_transfer() is called to setup some basic properties for the
+ * upcoming transfer.
+ */
+CURLcode
+Curl_setup_transfer(
+  struct connectdata *conn, /* connection data */
+  int sockindex,            /* socket index to read from or -1 */
+  curl_off_t size,          /* -1 if unknown at this point */
+  bool getheader,           /* TRUE if header parsing is wanted */
+  curl_off_t *bytecountp,   /* return number of bytes read or NULL */
+  int writesockindex,       /* socket index to write to, it may very well be
+                               the same we read from. -1 disables */
+  curl_off_t *writecountp   /* return number of bytes written or NULL */
+  )
+{
+  struct SessionHandle *data;
+  struct SingleRequest *k;
+
+  DEBUGASSERT(conn != NULL);
+
+  data = conn->data;
+  k = &data->req;
+
+  DEBUGASSERT((sockindex <= 1) && (sockindex >= -1));
+
+  /* now copy all input parameters */
+  conn->sockfd = sockindex == -1 ?
+      CURL_SOCKET_BAD : conn->sock[sockindex];
+  conn->writesockfd = writesockindex == -1 ?
+      CURL_SOCKET_BAD:conn->sock[writesockindex];
+  k->getheader = getheader;
+
+  k->size = size;
+  k->bytecountp = bytecountp;
+  k->writebytecountp = writecountp;
+
+  /* The code sequence below is placed in this function just because all
+     necessary input is not always known in do_complete() as this function may
+     be called after that */
+
+  if(!k->getheader) {
+    k->header = FALSE;
+    if(size > 0)
+      Curl_pgrsSetDownloadSize(data, size);
+  }
+  /* we want header and/or body, if neither then don't do this! */
+  if(k->getheader || !data->set.opt_no_body) {
+
+    if(conn->sockfd != CURL_SOCKET_BAD) {
+      k->keepon |= KEEP_RECV;
+    }
+
+    if(conn->writesockfd != CURL_SOCKET_BAD) {
+      /* HTTP 1.1 magic:
+
+         Even if we require a 100-return code before uploading data, we might
+         need to write data before that since the REQUEST may not have been
+         finished sent off just yet.
+
+         Thus, we must check if the request has been sent before we set the
+         state info where we wait for the 100-return code
+      */
+      if((data->state.expect100header) &&
+         (data->state.proto.http->sending == HTTPSEND_BODY)) {
+        /* wait with write until we either got 100-continue or a timeout */
+        k->exp100 = EXP100_AWAITING_CONTINUE;
+        k->start100 = k->start;
+      }
+      else {
+        if(data->state.expect100header)
+          /* when we've sent off the rest of the headers, we must await a
+             100-continue but first finish sending the request */
+          k->exp100 = EXP100_SENDING_REQUEST;
+
+        /* enable the write bit when we're not waiting for continue */
+        k->keepon |= KEEP_SEND;
+      }
+    } /* if(conn->writesockfd != CURL_SOCKET_BAD) */
+  } /* if(k->getheader || !data->set.opt_no_body) */
+
+  return CURLE_OK;
+}