Re: [Qemu-devel] [PATCH v2] qga: replace GetIfEntry

[Michael Roth]

Quoting ZhiPeng Lu (2017-11-03 09:54:20)
> The data obtained by GetIfEntry is 32 bits, and it may overflow. Thus using 
> GetIfEntry2 instead of GetIfEntry.
> 
> Signed-off-by: ZhiPeng Lu <address@hidden>
> ---
>  qga/commands-win32.c | 31 ++++++++++++++++++-------------
>  1 file changed, 18 insertions(+), 13 deletions(-)
> 
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index 0322188..d096dc2 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -1173,20 +1173,25 @@ static int guest_get_network_stats(const char *name,
>                         GuestNetworkInterfaceStat *stats)
>  {
>      DWORD if_index = 0;
> -    MIB_IFROW a_mid_ifrow;
> -    memset(&a_mid_ifrow, 0, sizeof(a_mid_ifrow));
> +    OSVERSIONINFO OSver;
>      if_index = get_interface_index(name);
> -    a_mid_ifrow.dwIndex = if_index;
> -    if (NO_ERROR == GetIfEntry(&a_mid_ifrow)) {
> -        stats->rx_bytes = a_mid_ifrow.dwInOctets;
> -        stats->rx_packets = a_mid_ifrow.dwInUcastPkts;
> -        stats->rx_errs = a_mid_ifrow.dwInErrors;
> -        stats->rx_dropped = a_mid_ifrow.dwInDiscards;
> -        stats->tx_bytes = a_mid_ifrow.dwOutOctets;
> -        stats->tx_packets = a_mid_ifrow.dwOutUcastPkts;
> -        stats->tx_errs = a_mid_ifrow.dwOutErrors;
> -        stats->tx_dropped = a_mid_ifrow.dwOutDiscards;
> -        return 0;
> +    OSver.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
> +    GetVersionEx(&OSver);
> +    if (OSver.dwMajorVersion >= 6) {
> +        MIB_IF_ROW2 a_mid_ifrow;
> +        memset(&a_mid_ifrow, 0, sizeof(a_mid_ifrow));
> +        a_mid_ifrow.dwIndex = if_index;
> +        if (NO_ERROR == GetIfEntry2(&a_mid_ifrow)) {
> +            stats->rx_bytes = a_mid_ifrow.dwInOctets;
> +            stats->rx_packets = a_mid_ifrow.dwInUcastPkts;
> +            stats->rx_errs = a_mid_ifrow.dwInErrors;
> +            stats->rx_dropped = a_mid_ifrow.dwInDiscards;
> +            stats->tx_bytes = a_mid_ifrow.dwOutOctets;
> +            stats->tx_packets = a_mid_ifrow.dwOutUcastPkts;
> +            stats->tx_errs = a_mid_ifrow.dwOutErrors;
> +            stats->tx_dropped = a_mid_ifrow.dwOutDiscards;
> +            return 0;

This fails to build in my fc20 mingw64 environment:

/home/mdroth/w/qemu4.git/qga/commands-win32.c:1184:20: error: 'MIB_IF_ROW2' has 
no member named 'dwIndex'
         a_mid_ifrow.dwIndex = if_index;
                    ^
/home/mdroth/w/qemu4.git/qga/commands-win32.c:1186:42: error: 'MIB_IF_ROW2' has 
no member named 'dwInOctets'
             stats->rx_bytes = a_mid_ifrow.dwInOctets;
                                          ^
/home/mdroth/w/qemu4.git/qga/commands-win32.c:1187:44: error: 'MIB_IF_ROW2' has 
no member named 'dwInUcastPkts'
             stats->rx_packets = a_mid_ifrow.dwInUcastPkts;

etc ...

The patch seems to assume MIB_IFROW and MIB_IF_ROW2 have the same field names
for the stats, but according to this they're slightly different:

  
https://msdn.microsoft.com/en-us/library/windows/desktop/aa814491(v=vs.85).aspx

This change on top of your patch seems to work:

diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index e17fc3c284..58e470877f 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -1181,16 +1181,16 @@ static int guest_get_network_stats(const char *name,
     if (os_ver.dwMajorVersion >= 6) {
         MIB_IF_ROW2 a_mid_ifrow;
         memset(&a_mid_ifrow, 0, sizeof(a_mid_ifrow));
-        a_mid_ifrow.dwIndex = if_index;
+        a_mid_ifrow.InterfaceIndex = if_index;
         if (NO_ERROR == GetIfEntry2(&a_mid_ifrow)) {
-            stats->rx_bytes = a_mid_ifrow.dwInOctets;
-            stats->rx_packets = a_mid_ifrow.dwInUcastPkts;
-            stats->rx_errs = a_mid_ifrow.dwInErrors;
-            stats->rx_dropped = a_mid_ifrow.dwInDiscards;
-            stats->tx_bytes = a_mid_ifrow.dwOutOctets;
-            stats->tx_packets = a_mid_ifrow.dwOutUcastPkts;
-            stats->tx_errs = a_mid_ifrow.dwOutErrors;
-            stats->tx_dropped = a_mid_ifrow.dwOutDiscards;
+            stats->rx_bytes = a_mid_ifrow.InOctets;
+            stats->rx_packets = a_mid_ifrow.InUcastPkts;
+            stats->rx_errs = a_mid_ifrow.InErrors;
+            stats->rx_dropped = a_mid_ifrow.InDiscards;
+            stats->tx_bytes = a_mid_ifrow.OutOctets;
+            stats->tx_packets = a_mid_ifrow.OutUcastPkts;
+            stats->tx_errs = a_mid_ifrow.OutErrors;
+            stats->tx_dropped = a_mid_ifrow.OutDiscards;
             return 0;
         }
     }

I have the modified patch staged here:

  https://github.com/mdroth/qemu/commit/de597a8b27722ce4f9cc660f930f7dccc712712d

Let me know if it looks okay and I'll send a pull request for rc1

> +        }
>      }
>      return -1;
>  }
> -- 
> 1.8.3.1
>