ucb: webdav-curl: don't read from XInputStream during upload

Nextcloud will reply to a PROPFIND request with "100 Continue" and then
after the data is uploaded it will send a "401 Unauthorized" if the
auth header is missing in the headers to which it replied with "100
Continue".

In the next call to ProcessRequestImpl(), reading from the stream
returns no data because it's at EOF, and because of the Content-Length
header the server will hang forever waiting for data.

So copy the stream to a temporary buffer and use that for multiple
calls to ProcessRequestImpl().

Change-Id: If5943a32c4cf50259fe1f84013141765cb5bd891
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/125923
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

1 files changed, 57 insertions, 16 deletions

diff --git a/ucb/source/ucp/webdav-curl/CurlSession.cxx b/ucb/source/ucp/webdav-curl/CurlSession.cxx
index 43bfa6cb85f8..d63d3566bfaa 100644
--- a/ucb/source/ucp/webdav-curl/CurlSession.cxx
+++ b/ucb/source/ucp/webdav-curl/CurlSession.cxx
@@ -18,6 +18,8 @@
 #include <comphelper/scopeguard.hxx>
 #include <comphelper/string.hxx>
 
+#include <o3tl/safeint.hxx>
+
 #include <officecfg/Inet.hxx>
 
 #include <com/sun/star/beans/NamedValue.hpp>
@@ -89,12 +91,13 @@ struct DownloadTarget
 
 struct UploadSource
 {
-    uno::Reference<io::XInputStream> xInStream;
+    uno::Sequence<sal_Int8> const& rInData;
     ResponseHeaders const& rHeaders;
-    UploadSource(uno::Reference<io::XInputStream> const& i_xInStream,
-                 ResponseHeaders const& i_rHeaders)
-        : xInStream(i_xInStream)
+    size_t nPosition;
+    UploadSource(uno::Sequence<sal_Int8> const& i_rInData, ResponseHeaders const& i_rHeaders)
+        : rInData(i_rInData)
         , rHeaders(i_rHeaders)
+        , nPosition(0)
     {
     }
 };
@@ -348,15 +351,14 @@ static size_t read_callback(char* const buffer, size_t const size, size_t const
 {
     auto* const pSource(static_cast<UploadSource*>(userdata));
     assert(pSource);
-    assert(pSource->xInStream.is());
     size_t const nBytes(size * nitems);
     size_t nRet(0);
     try
     {
-        uno::Sequence<sal_Int8> data;
-        data.realloc(nBytes);
-        nRet = pSource->xInStream->readSomeBytes(data, nBytes);
-        ::std::memcpy(buffer, data.getConstArray(), nRet);
+        assert(pSource->nPosition <= o3tl::make_unsigned(pSource->rInData.getLength()));
+        nRet = ::std::min<size_t>(pSource->rInData.getLength() - pSource->nPosition, nBytes);
+        ::std::memcpy(buffer, pSource->rInData.getConstArray() + pSource->nPosition, nRet);
+        pSource->nPosition += nRet;
     }
     catch (...)
     {
@@ -737,7 +739,7 @@ struct CurlProcessor
     static auto ProcessRequestImpl(
         CurlSession& rSession, CurlUri const& rURI, curl_slist* pRequestHeaderList,
         uno::Reference<io::XOutputStream> const* pxOutStream,
-        uno::Reference<io::XInputStream> const* pxInStream,
+        uno::Sequence<sal_Int8> const* pInData,
         ::std::pair<::std::vector<OUString> const&, DAVResource&> const* pRequestedHeaders,
         ResponseHeaders& rHeaders) -> void;
 
@@ -792,7 +794,7 @@ auto CurlProcessor::URIReferenceToURI(CurlSession& rSession, OUString const& rUR
 auto CurlProcessor::ProcessRequestImpl(
     CurlSession& rSession, CurlUri const& rURI, curl_slist* const pRequestHeaderList,
     uno::Reference<io::XOutputStream> const* const pxOutStream,
-    uno::Reference<io::XInputStream> const* const pxInStream,
+    uno::Sequence<sal_Int8> const* const pInData,
     ::std::pair<::std::vector<OUString> const&, DAVResource&> const* const pRequestedHeaders,
     ResponseHeaders& rHeaders) -> void
 {
@@ -805,7 +807,7 @@ auto CurlProcessor::ProcessRequestImpl(
             rc = curl_easy_setopt(rSession.m_pCurl.get(), CURLOPT_WRITEDATA, nullptr);
             assert(rc == CURLE_OK);
         }
-        if (pxInStream)
+        if (pInData)
         {
             rc = curl_easy_setopt(rSession.m_pCurl.get(), CURLOPT_READDATA, nullptr);
             assert(rc == CURLE_OK);
@@ -839,9 +841,9 @@ auto CurlProcessor::ProcessRequestImpl(
         assert(rc == CURLE_OK);
     }
     ::std::optional<UploadSource> oUploadSource;
-    if (pxInStream)
+    if (pInData)
     {
-        oUploadSource.emplace(*pxInStream, rHeaders);
+        oUploadSource.emplace(*pInData, rHeaders);
         rc = curl_easy_setopt(rSession.m_pCurl.get(), CURLOPT_READDATA, &*oUploadSource);
         assert(rc == CURLE_OK);
         // libcurl won't upload without setting this
@@ -1103,6 +1105,45 @@ auto CurlProcessor::ProcessRequest(
         }
     }
 
+    uno::Sequence<sal_Int8> data;
+    if (pxInStream)
+    {
+        uno::Reference<io::XSeekable> const xSeekable(*pxInStream, uno::UNO_QUERY);
+        if (xSeekable.is())
+        {
+            auto const len(xSeekable->getLength() - xSeekable->getPosition());
+            if ((**pxInStream).readBytes(data, len) != len)
+            {
+                throw uno::RuntimeException("short readBytes");
+            }
+        }
+        else
+        {
+            ::std::vector<uno::Sequence<sal_Int8>> bufs;
+            bool isDone(false);
+            do
+            {
+                bufs.emplace_back();
+                isDone = (**pxInStream).readSomeBytes(bufs.back(), 65536) == 0;
+            } while (!isDone);
+            sal_Int32 nSize(0);
+            for (auto const& rBuf : bufs)
+            {
+                if (o3tl::checked_add(nSize, rBuf.getLength(), nSize))
+                {
+                    throw std::bad_alloc(); // too large for Sequence
+                }
+            }
+            data.realloc(nSize);
+            size_t nCopied(0);
+            for (auto const& rBuf : bufs)
+            {
+                ::std::memcpy(data.getArray() + nCopied, rBuf.getConstArray(), rBuf.getLength());
+                nCopied += rBuf.getLength(); // can't overflow
+            }
+        }
+    }
+
     // Clear flag before transfer starts; only a transfer started before
     // calling abort() will be aborted, not one started later.
     rSession.m_AbortFlag.store(false);
@@ -1227,8 +1268,8 @@ auto CurlProcessor::ProcessRequest(
 
         try
         {
-            ProcessRequestImpl(rSession, rURI, pRequestHeaderList.get(), pxOutStream, pxInStream,
-                               pRequestedHeaders, headers);
+            ProcessRequestImpl(rSession, rURI, pRequestHeaderList.get(), pxOutStream,
+                               pxInStream ? &data : nullptr, pRequestedHeaders, headers);
         }
         catch (DAVException const& rException)
         {