From 863981e96738983919de841ec669e157e6bdaeb0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Sun, 11 Sep 2016 04:34:46 -0300
Subject: Linux-libre 4.7.1-gnu

---
 net/netfilter/nf_conntrack_labels.c | 44 ++++++++++++++-----------------------
 1 file changed, 16 insertions(+), 28 deletions(-)

(limited to 'net/netfilter/nf_conntrack_labels.c')

diff --git a/net/netfilter/nf_conntrack_labels.c b/net/netfilter/nf_conntrack_labels.c
index 3ce5c314e..252e6a7cd 100644
--- a/net/netfilter/nf_conntrack_labels.c
+++ b/net/netfilter/nf_conntrack_labels.c
@@ -16,28 +16,11 @@
 
 static spinlock_t nf_connlabels_lock;
 
-static unsigned int label_bits(const struct nf_conn_labels *l)
-{
-	unsigned int longs = l->words;
-	return longs * BITS_PER_LONG;
-}
-
-bool nf_connlabel_match(const struct nf_conn *ct, u16 bit)
-{
-	struct nf_conn_labels *labels = nf_ct_labels_find(ct);
-
-	if (!labels)
-		return false;
-
-	return bit < label_bits(labels) && test_bit(bit, labels->bits);
-}
-EXPORT_SYMBOL_GPL(nf_connlabel_match);
-
 int nf_connlabel_set(struct nf_conn *ct, u16 bit)
 {
 	struct nf_conn_labels *labels = nf_ct_labels_find(ct);
 
-	if (!labels || bit >= label_bits(labels))
+	if (!labels || BIT_WORD(bit) >= labels->words)
 		return -ENOSPC;
 
 	if (test_bit(bit, labels->bits))
@@ -50,14 +33,18 @@ int nf_connlabel_set(struct nf_conn *ct, u16 bit)
 }
 EXPORT_SYMBOL_GPL(nf_connlabel_set);
 
-static void replace_u32(u32 *address, u32 mask, u32 new)
+static int replace_u32(u32 *address, u32 mask, u32 new)
 {
 	u32 old, tmp;
 
 	do {
 		old = *address;
 		tmp = (old & mask) ^ new;
+		if (old == tmp)
+			return 0;
 	} while (cmpxchg(address, old, tmp) != old);
+
+	return 1;
 }
 
 int nf_connlabels_replace(struct nf_conn *ct,
@@ -66,6 +53,7 @@ int nf_connlabels_replace(struct nf_conn *ct,
 {
 	struct nf_conn_labels *labels;
 	unsigned int size, i;
+	int changed = 0;
 	u32 *dst;
 
 	labels = nf_ct_labels_find(ct);
@@ -77,29 +65,27 @@ int nf_connlabels_replace(struct nf_conn *ct,
 		words32 = size / sizeof(u32);
 
 	dst = (u32 *) labels->bits;
-	if (words32) {
-		for (i = 0; i < words32; i++)
-			replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
-	}
+	for (i = 0; i < words32; i++)
+		changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
 
 	size /= sizeof(u32);
 	for (i = words32; i < size; i++) /* pad */
 		replace_u32(&dst[i], 0, 0);
 
-	nf_conntrack_event_cache(IPCT_LABEL, ct);
+	if (changed)
+		nf_conntrack_event_cache(IPCT_LABEL, ct);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(nf_connlabels_replace);
 
-int nf_connlabels_get(struct net *net, unsigned int n_bits)
+int nf_connlabels_get(struct net *net, unsigned int bits)
 {
 	size_t words;
 
-	if (n_bits > (NF_CT_LABELS_MAX_SIZE * BITS_PER_BYTE))
+	words = BIT_WORD(bits) + 1;
+	if (words > NF_CT_LABELS_MAX_SIZE / sizeof(long))
 		return -ERANGE;
 
-	words = BITS_TO_LONGS(n_bits);
-
 	spin_lock(&nf_connlabels_lock);
 	net->ct.labels_used++;
 	if (words > net->ct.label_words)
@@ -128,6 +114,8 @@ static struct nf_ct_ext_type labels_extend __read_mostly = {
 
 int nf_conntrack_labels_init(void)
 {
+	BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX);
+
 	spin_lock_init(&nf_connlabels_lock);
 	return nf_ct_extend_register(&labels_extend);
 }
-- 
cgit v1.2.3-54-g00ecf