Clean up handling of invalid HWID when running ChromeOS in VMs

chromeos/system/statistics_provider.cc

Index: chromeos/system/statistics_provider.cc
diff --git a/chromeos/system/statistics_provider.cc b/chromeos/system/statistics_provider.cc
index 18c697681aa5e6ff66a2578d14a6db441b2bcc91..8e40339151d9d4e765bf5fcde627ad0a0d93209c 100644
--- a/chromeos/system/statistics_provider.cc
+++ b/chromeos/system/statistics_provider.cc
@@ -17,6 +17,7 @@
 #include "base/memory/singleton.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
 #include "base/synchronization/cancellation_flag.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/sys_info.h"
@@ -41,13 +42,14 @@ const char* kCrosSystemTool[] = { "/usr/bin/crossystem" };
 const char kCrosSystemEq[] = "=";
 const char kCrosSystemDelim[] = "\n";
 const char kCrosSystemCommentDelim[] = "#";
-const char kCrosSystemUnknownValue[] = "(error)";
+const char kCrosSystemValueError[] = "(error)";
 
 const char kHardwareClassCrosSystemKey[] = "hwid";
-const char kUnknownHardwareClass[] = "unknown";
+const char kHardwareClassValueUnknown[] = "unknown";
 
-// File to get system vendor information from.
+// File to get system vendor information from. (x86-only)
 const char kSystemVendorFile[] = "/sys/class/dmi/id/sys_vendor";
+const char kSystemVendorValueUnknown[] = "unknown";
 
 // Key/value delimiters of machine hardware info file. machine-info is generated
 // only for OOBE and enterprise enrollment and may not be present. See
@@ -158,6 +160,7 @@ const char kFirmwareTypeValueDeveloper[] = "developer";
 const char kFirmwareTypeValueNonchrome[] = "nonchrome";
 const char kFirmwareTypeValueNormal[] = "normal";
 const char kHardwareClassKey[] = "hardware_class";
+const char kHardwareClassValueVM[] = "VM";
 const char kSystemVendorKey[] = "system_vendor";
 const char kOffersCouponCodeKey[] = "ubind_attribute";
 const char kOffersGroupCodeKey[] = "gbind_attribute";
@@ -447,12 +450,6 @@ void StatisticsProviderImpl::LoadMachineStatistics(bool load_oem_manifest) {
     }
   }
 
-  if (base::SysInfo::IsRunningOnChromeOS()) {
-    std::string system_vendor;
-    base::ReadFileToString(base::FilePath(kSystemVendorFile), &system_vendor);
-    machine_info_[kSystemVendorKey] = system_vendor;
-  }
-
   parser.GetNameValuePairsFromFile(machine_info_path,
                                    kMachineHardwareInfoEq,
                                    kMachineHardwareInfoDelim);
@@ -466,10 +463,31 @@ void StatisticsProviderImpl::LoadMachineStatistics(bool load_oem_manifest) {
   // Ensure that the hardware class key is present with the expected
   // key name, and if it couldn't be retrieved, that the value is "unknown".
   std::string hardware_class = machine_info_[kHardwareClassCrosSystemKey];
-  if (hardware_class.empty() || hardware_class == kCrosSystemUnknownValue)
-    machine_info_[kHardwareClassKey] = kUnknownHardwareClass;
-  else
+  if (hardware_class.empty() || hardware_class == kCrosSystemValueError) {
+    machine_info_[kHardwareClassKey] = kHardwareClassValueUnknown;
+    // If the HWID couldn't be retrieved and the the FWID is "nonchrome", assume
+    // that ChromeOS is running inside a VM and set the HWID to "VM"

[Daniel Erat, 2016/08/05 19:03:54]

nit: s/ChromeOS/Chrome OS/; also add trailing period

[achuithb, 2016/08/05 21:23:32]

You should add a real test to detect that you're in a VM - not just assume that
missing HWID implies a VM. This assumption is not right.

I don't think this CL is ok.

Some ideas here:
http://www.dmo.ca/blog/detecting-virtualization-on-linux/

+    if (base::SysInfo::IsRunningOnChromeOS()) {
+      if (machine_info_[kFirmwareTypeKey] == kFirmwareTypeValueNonchrome) {
+        LOG(WARNING) << "Detected non-Chrome firmware with malformed HWID,"

[Daniel Erat, 2016/08/05 19:03:54]

nit: maybe move this down and combine it with the other log statement so we just
log one line?

+                     << " assuming VM environment.";
+        machine_info_[kHardwareClassKey] = kHardwareClassValueVM;
+        std::string system_vendor;
+        base::ReadFileToString(base::FilePath(kSystemVendorFile),
+                               &system_vendor);
+        base::TrimWhitespaceASCII(system_vendor, base::TRIM_ALL,
+                                  &system_vendor);
+        if (system_vendor.empty())
+          machine_info_[kSystemVendorKey] = kSystemVendorValueUnknown;

[Daniel Erat, 2016/08/05 19:03:54]

if i'm not misreading this, machine_info_[kSystemVendorKey] only gets set in the
unknown-hardware-class, non-chrome-firmware case now, while before it was always
set. is this change intentional?

+        else
+          machine_info_[kSystemVendorKey] = system_vendor;
+        LOG(WARNING) << "The system vendor is '"
+                     << machine_info_[kSystemVendorKey] << "'.";
+      }
+    }
+  } else {
     machine_info_[kHardwareClassKey] = hardware_class;
+  }
 
   if (load_oem_manifest) {
     // If kAppOemManifestFile switch is specified, load OEM Manifest file.