Upgrade update_engine from Omaha v2 to v3 protocol.

Omaha had released the v3 protocol long back, but update_engine kept
using the v2 protocol as there was no immediate need to move. But now
that we need to support HTTP-based downloads, we need to supply multiple
URLs for each rule, one for HTTP, one for HTTPS fallback. Even for
HTTPs, it is also useful for scenarios such as specifying a Google
storage URL as the primary download point and keeping Lorry as a backup
URL. Multiple URL support is available only on Omaha v3 protocol.

So, this CL is to first upgrade of the client protocol from v2 to v3. It
does not add any new functionality and still supports only one URL. The
subsequent checkins will take advantage of the multiple URL support.

This CL also includes a sample xml file which illustrates how the new
response from the Omaha v3 server would look like, which should greatly
help in understand the changes.

As part of this change, I've also consolidated a few error codes which
had practically zero occurrence into one error code and reused those
error codes for the recently added errors (which haven't been shipped
anywhere yet). Since we're now publishing all the error codes in UMA, we
need to be conservative in defining distinct error codes in order to
reduce the memory usage of Chrome for UMA stats.

BUG=chromium-os:6594
TEST=Tested on ZGB with Omaha v3 server. Updated unit tests and they pass.
Change-Id: I187aa0500e39623684130ba9e3d1d948c0e60627
Reviewed-on: https://gerrit.chromium.org/gerrit/36758
Reviewed-by: Jay Srinivasan <jaysri@chromium.org>
Tested-by: Jay Srinivasan <jaysri@chromium.org>
Commit-Ready: Chris Sosa <sosa@chromium.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/action_processor.h b/action_processor.h
index e193c67b..3f8dceed 100644
--- a/action_processor.h
+++ b/action_processor.h
@@ -55,16 +55,14 @@ enum ActionExitCode {
   kActionCodeDownloadOperationHashMismatch = 29,
   kActionCodeOmahaRequestEmptyResponseError = 30,
   kActionCodeOmahaRequestXMLParseError = 31,
-  kActionCodeOmahaRequestNoUpdateCheckNode = 32,
-  kActionCodeOmahaRequestNoUpdateCheckStatus = 33,
-  kActionCodeOmahaRequestBadUpdateCheckStatus = 34,
+  kActionCodeDownloadInvalidMetadataSize = 32,
+  kActionCodeDownloadInvalidMetadataSignature = 33,
+  kActionCodeOmahaResponseInvalid = 34,
   kActionCodeOmahaUpdateIgnoredPerPolicy = 35,
   kActionCodeOmahaUpdateDeferredPerPolicy = 36,
   kActionCodeOmahaErrorInHTTPResponse = 37,
   kActionCodeDownloadOperationHashMissingError = 38,
-  kActionCodeDownloadInvalidMetadataSize = 39,
-  kActionCodeDownloadInvalidMetadataSignature = 40,
-  kActionCodeDownloadMetadataSignatureMissingError = 41,
+  kActionCodeDownloadMetadataSignatureMissingError = 39,
 
   // Any code above this is sent to both Omaha and UMA as-is.
   // Codes/flags below this line is sent only to Omaha and not to UMA.