[ovs-dev] [PATCH] datapath: Additional logging for -EINVAL on flow setups.

[Jesse Gross]

There are many possible ways that a flow can be invalid so we've
added logging for most of them. This adds logs for the remaining
possible cases so there isn't any ambiguity while debugging.

CC: Federico Iezzi <fiezzi at enter.it>
Signed-off-by: Jesse Gross <jesse at nicira.com>
---
 datapath/datapath.c     | 12 +++++++++---
 datapath/flow_netlink.c | 18 ++++++++++++++----
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 7250b63..136a478 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -843,10 +843,14 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 
 	/* Must have key and actions. */
 	error = -EINVAL;
-	if (!a[OVS_FLOW_ATTR_KEY])
+	if (!a[OVS_FLOW_ATTR_KEY]) {
+		OVS_NLERR("Flow key attribute not present in new flow.\n");
 		goto error;
-	if (!a[OVS_FLOW_ATTR_ACTIONS])
+	}
+	if (!a[OVS_FLOW_ATTR_ACTIONS]) {
+		OVS_NLERR("Flow actions attribute not present in new flow.\n");
 		goto error;
+	}
 
 	/* Most of the time we need to allocate a new flow, do it before
 	 * locking. */
@@ -1005,8 +1009,10 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
 
 	/* Extract key. */
 	error = -EINVAL;
-	if (!a[OVS_FLOW_ATTR_KEY])
+	if (!a[OVS_FLOW_ATTR_KEY]) {
+		OVS_NLERR("Flow key attribute not present in set flow.\n");
 		goto error;
+	}
 
 	ovs_match_init(&match, &key, &mask);
 	error = ovs_nla_get_match(&match,
diff --git a/datapath/flow_netlink.c b/datapath/flow_netlink.c
index 925e9fb..6ae69e9 100644
--- a/datapath/flow_netlink.c
+++ b/datapath/flow_netlink.c
@@ -462,6 +462,7 @@ static int ipv4_tun_from_nlattr(const struct nlattr *attr,
 				nla_data(a), nla_len(a), is_mask);
 			break;
 		default:
+			OVS_NLERR("Unknown IPv4 tunnel attribute (%d).\n", type);
 			return -EINVAL;
 		}
 	}
@@ -558,10 +559,13 @@ static int metadata_from_nlattrs(struct sw_flow_match *match,  u64 *attrs,
 	if (*attrs & (1ULL << OVS_KEY_ATTR_IN_PORT)) {
 		u32 in_port = nla_get_u32(a[OVS_KEY_ATTR_IN_PORT]);
 
-		if (is_mask)
+		if (is_mask) {
 			in_port = 0xffffffff; /* Always exact match in_port. */
-		else if (in_port >= DP_MAX_PORTS)
+		} else if (in_port >= DP_MAX_PORTS) {
+			OVS_NLERR("Input port (%d) exceeds maximum allowable (%d).\n",
+				  in_port, DP_MAX_PORTS);
 			return -EINVAL;
+		}
 
 		SW_FLOW_KEY_PUT(match, phy.in_port, in_port, is_mask);
 		*attrs &= ~(1ULL << OVS_KEY_ATTR_IN_PORT);
@@ -801,8 +805,11 @@ static int ovs_key_from_nlattrs(struct sw_flow_match *match, u64 attrs,
 		attrs &= ~(1ULL << OVS_KEY_ATTR_ND);
 	}
 
-	if (attrs != 0)
+	if (attrs != 0) {
+		OVS_NLERR("Unknown key attributes (%llx).\n",
+			  (unsigned long long)attrs);
 		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -1203,8 +1210,11 @@ struct sw_flow_actions *ovs_nla_alloc_flow_actions(int size)
 {
 	struct sw_flow_actions *sfa;
 
-	if (size > MAX_ACTIONS_BUFSIZE)
+	if (size > MAX_ACTIONS_BUFSIZE) {
+		OVS_NLERR("Flow action size (%u bytes) exceeds maximum "
+			  "(%u bytes)\n", size, MAX_ACTIONS_BUFSIZE);
 		return ERR_PTR(-EINVAL);
+	}
 
 	sfa = kmalloc(sizeof(*sfa) + size, GFP_KERNEL);
 	if (!sfa)
-- 
1.9.1