From a4a75b638f5cecbfae3f9809f9b535e1f9eaa9a5 Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Fri, 20 May 2016 17:53:58 +0200
Subject: [PATCH] platform: refactor comparing for all-zero,all-ones MAC
 address in nmp_utils_ethtool_get_permanent_address()

Don't like the static fields.

Also, don't assert against return values from the ethtool call.
And check that the length is positive.
---
 src/platform/nm-platform-utils.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/platform/nm-platform-utils.c b/src/platform/nm-platform-utils.c
index 8aa93ed81d..068801ee69 100644
--- a/src/platform/nm-platform-utils.c
+++ b/src/platform/nm-platform-utils.c
@@ -144,8 +144,7 @@ nmp_utils_ethtool_get_permanent_address (const char *ifname,
 		struct ethtool_perm_addr e;
 		guint8 _extra_data[NM_UTILS_HWADDR_LEN_MAX + 1];
 	} edata;
-	static const guint8 zeros[NM_UTILS_HWADDR_LEN_MAX] = { 0 };
-	static guint8 ones[NM_UTILS_HWADDR_LEN_MAX] = { 0 };
+	guint i;
 
 	if (!ifname)
 		return FALSE;
@@ -157,18 +156,23 @@ nmp_utils_ethtool_get_permanent_address (const char *ifname,
 	if (!ethtool_get (ifname, &edata.e))
 		return FALSE;
 
-	g_assert (edata.e.size <= NM_UTILS_HWADDR_LEN_MAX);
-
-	/* Some drivers might return a permanent address of all zeros.
-	 * Reject that (rh#1264024) */
-	if (memcmp (edata.e.data, zeros, edata.e.size) == 0)
+	if (edata.e.size > NM_UTILS_HWADDR_LEN_MAX)
+		return FALSE;
+	if (edata.e.size < 1)
 		return FALSE;
 
-	/* Some drivers return a permanent address of all ones. Reject that too */
-	if (G_UNLIKELY (ones[0] != 0xFF))
-		memset (ones, 0xFF, sizeof (ones));
-	if (memcmp (edata.e.data, ones, edata.e.size) == 0)
+	if (NM_IN_SET (edata.e.data[0], 0, 0xFF)) {
+		/* Some drivers might return a permanent address of all zeros.
+		 * Reject that (rh#1264024)
+		 *
+		 * Some drivers return a permanent address of all ones. Reject that too */
+		for (i = 1; i < edata.e.size; i++) {
+			if (edata.e.data[0] != edata.e.data[i])
+				goto not_all_0or1;
+		}
 		return FALSE;
+	}
+not_all_0or1:
 
 	memcpy (buf, edata.e.data, edata.e.size);
 	*length = edata.e.size;