DORMANTno replies REVIEWED: 2 (0M)

2 review trailers.

[PATCH net-next v2 14/14] openvswitch: Avoid NULL mask check while building mask

From: Pravin B Shelar <hidden>
Date: 2014-11-06 09:19:55
Subsystem: networking [general], openvswitch, the rest · Maintainers: "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Aaron Conole, Eelco Chaudron, Ilya Maximets, Linus Torvalds

OVS does mask validation even if it does not need to convert
netlink mask attributes to mask structure.  ovs_nla_get_match()
caller can pass NULL mask structure pointer if the caller does
not need mask.  Therefore NULL check is required in SW_FLOW_KEY*
macros.  Following patch does not convert mask netlink attributes
if mask pointer is NULL, so we do not need these checks in
SW_FLOW_KEY* macro.

Signed-off-by: Pravin B Shelar <redacted>
Acked-by: Daniele Di Proietto <redacted>
Acked-by: Andy Zhou <redacted>
---
 net/openvswitch/flow_netlink.c | 107 ++++++++++++++++++++---------------------
 1 file changed, 53 insertions(+), 54 deletions(-)
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 482a0cb..ed31097 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -50,21 +50,18 @@
 
 #include "flow_netlink.h"
 
-static void update_range__(struct sw_flow_match *match,
-			   size_t offset, size_t size, bool is_mask)
+static void update_range(struct sw_flow_match *match,
+			 size_t offset, size_t size, bool is_mask)
 {
-	struct sw_flow_key_range *range = NULL;
+	struct sw_flow_key_range *range;
 	size_t start = rounddown(offset, sizeof(long));
 	size_t end = roundup(offset + size, sizeof(long));
 
 	if (!is_mask)
 		range = &match->range;
-	else if (match->mask)
+	else
 		range = &match->mask->range;
 
-	if (!range)
-		return;
-
 	if (range->start == range->end) {
 		range->start = start;
 		range->end = end;
@@ -80,22 +77,20 @@ static void update_range__(struct sw_flow_match *match,
 
 #define SW_FLOW_KEY_PUT(match, field, value, is_mask) \
 	do { \
-		update_range__(match, offsetof(struct sw_flow_key, field),  \
-				     sizeof((match)->key->field), is_mask); \
-		if (is_mask) {						    \
-			if ((match)->mask)				    \
-				(match)->mask->key.field = value;	    \
-		} else {                                                    \
+		update_range(match, offsetof(struct sw_flow_key, field),    \
+			     sizeof((match)->key->field), is_mask);	    \
+		if (is_mask)						    \
+			(match)->mask->key.field = value;		    \
+		else							    \
 			(match)->key->field = value;		            \
-		}                                                           \
 	} while (0)
 
 #define SW_FLOW_KEY_MEMCPY_OFFSET(match, offset, value_p, len, is_mask)	    \
 	do {								    \
-		update_range__(match, offset, len, is_mask);		    \
+		update_range(match, offset, len, is_mask);		    \
 		if (is_mask)						    \
 			memcpy((u8 *)&(match)->mask->key + offset, value_p, \
-			       len);					    \
+			       len);					   \
 		else							    \
 			memcpy((u8 *)(match)->key + offset, value_p, len);  \
 	} while (0)
@@ -104,18 +99,16 @@ static void update_range__(struct sw_flow_match *match,
 	SW_FLOW_KEY_MEMCPY_OFFSET(match, offsetof(struct sw_flow_key, field), \
 				  value_p, len, is_mask)
 
-#define SW_FLOW_KEY_MEMSET_FIELD(match, field, value, is_mask) \
-	do { \
-		update_range__(match, offsetof(struct sw_flow_key, field),  \
-				     sizeof((match)->key->field), is_mask); \
-		if (is_mask) {						    \
-			if ((match)->mask)				    \
-				memset((u8 *)&(match)->mask->key.field, value,\
-				       sizeof((match)->mask->key.field));   \
-		} else {                                                    \
+#define SW_FLOW_KEY_MEMSET_FIELD(match, field, value, is_mask)		    \
+	do {								    \
+		update_range(match, offsetof(struct sw_flow_key, field),    \
+			     sizeof((match)->key->field), is_mask);	    \
+		if (is_mask)						    \
+			memset((u8 *)&(match)->mask->key.field, value,      \
+			       sizeof((match)->mask->key.field));	    \
+		else							    \
 			memset((u8 *)&(match)->key->field, value,           \
 			       sizeof((match)->key->field));                \
-		}                                                           \
 	} while (0)
 
 static bool match_validate(const struct sw_flow_match *match,
@@ -677,8 +670,7 @@ static int ovs_key_from_nlattrs(struct sw_flow_match *match, u64 attrs,
 
 		SW_FLOW_KEY_PUT(match, eth.tci, tci, is_mask);
 		attrs &= ~(1 << OVS_KEY_ATTR_VLAN);
-	} else if (!is_mask)
-		SW_FLOW_KEY_PUT(match, eth.tci, htons(0xffff), true);
+	}
 
 	if (attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) {
 		__be16 eth_type;
@@ -903,8 +895,8 @@ static void mask_set_nlattr(struct nlattr *attr, u8 val)
  * attribute specifies the mask field of the wildcarded flow.
  */
 int ovs_nla_get_match(struct sw_flow_match *match,
-		      const struct nlattr *key,
-		      const struct nlattr *mask)
+		      const struct nlattr *nla_key,
+		      const struct nlattr *nla_mask)
 {
 	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
 	const struct nlattr *encap;
@@ -914,7 +906,7 @@ int ovs_nla_get_match(struct sw_flow_match *match,
 	bool encap_valid = false;
 	int err;
 
-	err = parse_flow_nlattrs(key, a, &key_attrs);
+	err = parse_flow_nlattrs(nla_key, a, &key_attrs);
 	if (err)
 		return err;
 
@@ -955,36 +947,43 @@ int ovs_nla_get_match(struct sw_flow_match *match,
 	if (err)
 		return err;
 
-	if (match->mask && !mask) {
-		/* Create an exact match mask. We need to set to 0xff all the
-		 * 'match->mask' fields that have been touched in 'match->key'.
-		 * We cannot simply memset 'match->mask', because padding bytes
-		 * and fields not specified in 'match->key' should be left to 0.
-		 * Instead, we use a stream of netlink attributes, copied from
-		 * 'key' and set to 0xff: ovs_key_from_nlattrs() will take care
-		 * of filling 'match->mask' appropriately.
-		 */
-		newmask = kmemdup(key, nla_total_size(nla_len(key)),
-				  GFP_KERNEL);
-		if (!newmask)
-			return -ENOMEM;
+	if (match->mask) {
+		if (!nla_mask) {
+			/* Create an exact match mask. We need to set to 0xff
+			 * all the 'match->mask' fields that have been touched
+			 * in 'match->key'. We cannot simply memset
+			 * 'match->mask', because padding bytes and fields not
+			 * specified in 'match->key' should be left to 0.
+			 * Instead, we use a stream of netlink attributes,
+			 * copied from 'key' and set to 0xff.
+			 * ovs_key_from_nlattrs() will take care of filling
+			 * 'match->mask' appropriately.
+			 */
+			newmask = kmemdup(nla_key,
+					  nla_total_size(nla_len(nla_key)),
+					  GFP_KERNEL);
+			if (!newmask)
+				return -ENOMEM;
 
-		mask_set_nlattr(newmask, 0xff);
+			mask_set_nlattr(newmask, 0xff);
 
-		/* The userspace does not send tunnel attributes that are 0,
-		 * but we should not wildcard them nonetheless.
-		 */
-		if (match->key->tun_key.ipv4_dst)
-			SW_FLOW_KEY_MEMSET_FIELD(match, tun_key, 0xff, true);
+			/* The userspace does not send tunnel attributes that
+			 * are 0, but we should not wildcard them nonetheless.
+			 */
+			if (match->key->tun_key.ipv4_dst)
+				SW_FLOW_KEY_MEMSET_FIELD(match, tun_key,
+							 0xff, true);
 
-		mask = newmask;
-	}
+			nla_mask = newmask;
+		}
 
-	if (mask) {
-		err = parse_flow_mask_nlattrs(mask, a, &mask_attrs);
+		err = parse_flow_mask_nlattrs(nla_mask, a, &mask_attrs);
 		if (err)
 			goto free_newmask;
 
+		/* Always match on tci. */
+		SW_FLOW_KEY_PUT(match, eth.tci, htons(0xffff), true);
+
 		if (mask_attrs & 1 << OVS_KEY_ATTR_ENCAP) {
 			__be16 eth_type = 0;
 			__be16 tci = 0;
-- 
1.9.3
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help