[Impala-ASF-CR] KUDU-2305: Limit sidecars to INT MAX and fortify socket code

["Lars Volker (Code Review)" <ge...@cloudera.org>]

Hello Michael Ho, Joe McDonnell, Impala Public Jenkins, 

I'd like you to reexamine a change. Please visit

    http://gerrit.cloudera.org:8080/10765

to look at the new patch set (#2).

Change subject: KUDU-2305: Limit sidecars to INT_MAX and fortify socket code
......................................................................

KUDU-2305: Limit sidecars to INT_MAX and fortify socket code

Inspection of the code revealed some other local variables
that could overflow with large messages. This patch takes
two approaches to eliminate the issues.

First, it limits the total size of the messages by limiting
the total size of the sidecars to INT_MAX. The total size
of the protobuf and header components of the message
should be considerably smaller, so limiting the sidecars
to INT_MAX eliminates messages that are larger than UINT_MAX.
This also means that the sidecar offsets, which are unsigned
32-bit integers, are also safe. Given that
FLAGS_rpc_max_message_size is limited to INT_MAX at startup,
the receiver would reject any message this large anyway.
This also helps with the networking codepath, as any given
sidecar will have a size less than INT_MAX, so every Slice
that interacts with Writev() is shorter than INT_MAX.

Second, even with sidecars limited to INT_MAX, the headers
and protobuf parts of the messages mean that certain messages
could still exceed INT_MAX. This patch changes some of the sockets
codepath to tolerate iovec's that reference more than INT_MAX
bytes total. Specifically, it changes Writev()'s nwritten bytes
to an int64_t for both TlsSocket and Socket. TlsSocket works
because it is sending each Slice individually. The first change
limited any given Slice to INT_MAX, so each individual Write()
should not be impacted. For Socket, Writev() uses sendmsg(). It
should do partial network sends to handle this case. Any Write()
call specifies its size with a 32-bit integer, and that will
not be impacted by this patch.

Testing:
 - Modified TestRpcSidecarLimits() to verify that sidecars are
   limited to INT_MAX bytes.
 - Added a test mode to TestRpcSidecarLimits() where it
   overrides rpc_max_message_size and sends the maximal
   message. This verifies that the client send codepath
   can handle the maximal message.

Reviewed-on: http://gerrit.cloudera.org:8080/9601
Reviewed-by: Todd Lipcon <to...@apache.org>
Tested-by: Todd Lipcon <to...@apache.org>

Changes from Kudu version:
 - Updated declaration of FLAGS_rpc_max_message_size
   in rpc-mgr.cc and added a warning not to set it
   larger than INT_MAX.

Change-Id: Id23e518995f2bf2f6bf6b49d5f413f3eaa4e79d1
Reviewed-on: http://gerrit.cloudera.org:8080/9748
Reviewed-by: Michael Ho <kw...@cloudera.com>
Tested-by: Impala Public Jenkins
---
M be/src/kudu/rpc/transfer.cc
1 file changed, 1 insertion(+), 1 deletion(-)


  git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/65/10765/2
-- 
To view, visit http://gerrit.cloudera.org:8080/10765
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Id23e518995f2bf2f6bf6b49d5f413f3eaa4e79d1
Gerrit-Change-Number: 10765
Gerrit-PatchSet: 2
Gerrit-Owner: Lars Volker <lv...@cloudera.com>
Gerrit-Reviewer: Impala Public Jenkins <im...@cloudera.com>
Gerrit-Reviewer: Joe McDonnell <jo...@cloudera.com>
Gerrit-Reviewer: Michael Ho <kw...@cloudera.com>