[PATCH v2 net-next 0/9] net: another round of extack handling for routing

[PATCH v2 net-next 0/9] net: another round of extack handling for routing

[David Ahern]

This set focuses on passing extack through lwtunnel and MPLS with
additional catches for IPv4 route add and minor cleanups in MPLS
encountered passing the extack arg around.

v2
- mindful of bloat adding duplicate messages
  + refactored prefix and prefix length checks in ipv4's fib_table_insert
    and fib_table_del
  + refactored label check in mpls

- split mpls cleanups into 2 patches
  + move nla_get_via up in af_mpls to avoid forward declaration

David Ahern (9):
  net: ipv4: refactor key and length checks
  net: ipv4: Add extack message for invalid prefix or length
  net: lwtunnel: Add extack to encap attr validation
  net: add extack arg to lwtunnel build state
  net: Fill in extack for mpls lwt encap
  net: mpls: Pull common label check into helper
  net: mpls: Add extack messages for route add and delete failures
  net: mpls: Make nla_get_via in af_mpls.c
  net: mpls: remove unnecessary initialization of err

 include/linux/netlink.h   |  10 ++
 include/net/ip_fib.h      |   3 +-
 include/net/lwtunnel.h    |  22 ++--
 net/core/lwt_bpf.c        |   5 +-
 net/core/lwtunnel.c       |  38 +++++--
 net/ipv4/fib_frontend.c   |  13 ++-
 net/ipv4/fib_lookup.h     |   3 +-
 net/ipv4/fib_semantics.c  |  20 ++--
 net/ipv4/fib_trie.c       |  34 +++---
 net/ipv4/ip_tunnel_core.c |  11 +-
 net/ipv6/ila/ila_lwt.c    |   5 +-
 net/ipv6/route.c          |   6 +-
 net/ipv6/seg6_iptunnel.c  |   5 +-
 net/mpls/af_mpls.c        | 266 +++++++++++++++++++++++++++++-----------------
 net/mpls/internal.h       |   4 +-
 net/mpls/mpls_iptunnel.c  |  17 +--
 16 files changed, 301 insertions(+), 161 deletions(-)

-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 1/9] net: ipv4: refactor key and length checks

[David Ahern]

fib_table_insert and fib_table_delete have the same checks on the prefix
and length. Refactor into a helper. Avoids duplicate extack messages in
the next patch.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 net/ipv4/fib_trie.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 6e9df7d9bcc2..9bd46e1e1037 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1099,6 +1099,17 @@ static int fib_insert_alias(struct trie *t, struct key_vector *tp,
 	return 0;
 }
 
+static bool fib_valid_key_len(u32 key, u8 plen)
+{
+	if (plen > KEYLENGTH)
+		return false;
+
+	if ((plen < KEYLENGTH) && (key << plen))
+		return false;
+
+	return true;
+}
+
 /* Caller must hold RTNL. */
 int fib_table_insert(struct net *net, struct fib_table *tb,
 		     struct fib_config *cfg, struct netlink_ext_ack *extack)
@@ -1115,16 +1126,13 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 	u32 key;
 	int err;
 
-	if (plen > KEYLENGTH)
-		return -EINVAL;
-
 	key = ntohl(cfg->fc_dst);
 
-	pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
-
-	if ((plen < KEYLENGTH) && (key << plen))
+	if (!fib_valid_key_len(key, plen))
 		return -EINVAL;
 
+	pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
+
 	fi = fib_create_info(cfg, extack);
 	if (IS_ERR(fi)) {
 		err = PTR_ERR(fi);
@@ -1518,12 +1526,9 @@ int fib_table_delete(struct net *net, struct fib_table *tb,
 	u8 tos = cfg->fc_tos;
 	u32 key;
 
-	if (plen > KEYLENGTH)
-		return -EINVAL;
-
 	key = ntohl(cfg->fc_dst);
 
-	if ((plen < KEYLENGTH) && (key << plen))
+	if (!fib_valid_key_len(key, plen))
 		return -EINVAL;
 
 	l = fib_find_node(t, &tp, key);
-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 2/9] net: ipv4: Add extack message for invalid prefix or length

[David Ahern]

Add extack error message for invalid prefix length and invalid prefix.
Example of the latter is a route spec containing 172.16.100.1/24, where
the /24 mask means the lower 8-bits should be 0. Amazing how easy that
one is to overlook when an EINVAL is returned.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/ip_fib.h    |  3 ++-
 net/ipv4/fib_frontend.c |  7 ++++---
 net/ipv4/fib_trie.c     | 17 +++++++++++------
 3 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 25f5c516afd1..c3fa1f0438c1 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -266,7 +266,8 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 		     struct fib_result *res, int fib_flags);
 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
 		     struct netlink_ext_ack *extack);
-int fib_table_delete(struct net *, struct fib_table *, struct fib_config *);
+int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
+		     struct netlink_ext_ack *extack);
 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
 		   struct netlink_callback *cb);
 int fib_table_flush(struct net *net, struct fib_table *table);
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 14d2f7bd7c76..715b7967d8ea 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -588,7 +588,8 @@ int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 			if (cmd == SIOCDELRT) {
 				tb = fib_get_table(net, cfg.fc_table);
 				if (tb)
-					err = fib_table_delete(net, tb, &cfg);
+					err = fib_table_delete(net, tb, &cfg,
+							       NULL);
 				else
 					err = -ESRCH;
 			} else {
@@ -732,7 +733,7 @@ static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 		goto errout;
 	}
 
-	err = fib_table_delete(net, tb, &cfg);
+	err = fib_table_delete(net, tb, &cfg, extack);
 errout:
 	return err;
 }
@@ -851,7 +852,7 @@ static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifad
 	if (cmd == RTM_NEWROUTE)
 		fib_table_insert(net, tb, &cfg, NULL);
 	else
-		fib_table_delete(net, tb, &cfg);
+		fib_table_delete(net, tb, &cfg, NULL);
 }
 
 void fib_add_ifaddr(struct in_ifaddr *ifa)
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 9bd46e1e1037..a624d380c81d 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1099,13 +1099,18 @@ static int fib_insert_alias(struct trie *t, struct key_vector *tp,
 	return 0;
 }
 
-static bool fib_valid_key_len(u32 key, u8 plen)
+static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
 {
-	if (plen > KEYLENGTH)
+	if (plen > KEYLENGTH) {
+		NL_SET_ERR_MSG(extack, "Invalid prefix length");
 		return false;
+	}
 
-	if ((plen < KEYLENGTH) && (key << plen))
+	if ((plen < KEYLENGTH) && (key << plen)) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid prefix for given prefix length");
 		return false;
+	}
 
 	return true;
 }
@@ -1128,7 +1133,7 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 
 	key = ntohl(cfg->fc_dst);
 
-	if (!fib_valid_key_len(key, plen))
+	if (!fib_valid_key_len(key, plen, extack))
 		return -EINVAL;
 
 	pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
@@ -1516,7 +1521,7 @@ static void fib_remove_alias(struct trie *t, struct key_vector *tp,
 
 /* Caller must hold RTNL. */
 int fib_table_delete(struct net *net, struct fib_table *tb,
-		     struct fib_config *cfg)
+		     struct fib_config *cfg, struct netlink_ext_ack *extack)
 {
 	struct trie *t = (struct trie *) tb->tb_data;
 	struct fib_alias *fa, *fa_to_delete;
@@ -1528,7 +1533,7 @@ int fib_table_delete(struct net *net, struct fib_table *tb,
 
 	key = ntohl(cfg->fc_dst);
 
-	if (!fib_valid_key_len(key, plen))
+	if (!fib_valid_key_len(key, plen, extack))
 		return -EINVAL;
 
 	l = fib_find_node(t, &tp, key);
-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 3/9] net: lwtunnel: Add extack to encap attr validation

[David Ahern]

Pass extack down to lwtunnel_valid_encap_type and
lwtunnel_valid_encap_type_attr. Add messages for unknown
or unsupported encap types.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/net/lwtunnel.h  | 13 +++++++++----
 net/core/lwtunnel.c     | 18 +++++++++++++-----
 net/ipv4/fib_frontend.c |  6 ++++--
 net/ipv6/route.c        |  4 ++--
 4 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h
index ebfe237aad7e..ca6f002774ef 100644
--- a/include/net/lwtunnel.h
+++ b/include/net/lwtunnel.h
@@ -107,8 +107,10 @@ int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 			   unsigned int num);
 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 			   unsigned int num);
-int lwtunnel_valid_encap_type(u16 encap_type);
-int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len);
+int lwtunnel_valid_encap_type(u16 encap_type,
+			      struct netlink_ext_ack *extack);
+int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
+				   struct netlink_ext_ack *extack);
 int lwtunnel_build_state(u16 encap_type,
 			 struct nlattr *encap,
 			 unsigned int family, const void *cfg,
@@ -172,11 +174,14 @@ static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 	return -EOPNOTSUPP;
 }
 
-static inline int lwtunnel_valid_encap_type(u16 encap_type)
+static inline int lwtunnel_valid_encap_type(u16 encap_type,
+					    struct netlink_ext_ack *extack)
 {
+	NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel");
 	return -EOPNOTSUPP;
 }
-static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len)
+static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
+						 struct netlink_ext_ack *extack)
 {
 	/* return 0 since we are not walking attr looking for
 	 * RTA_ENCAP_TYPE attribute on nexthops.
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
index cfae3d5fe11f..ab840386a74d 100644
--- a/net/core/lwtunnel.c
+++ b/net/core/lwtunnel.c
@@ -126,14 +126,16 @@ int lwtunnel_build_state(u16 encap_type,
 }
 EXPORT_SYMBOL(lwtunnel_build_state);
 
-int lwtunnel_valid_encap_type(u16 encap_type)
+int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack)
 {
 	const struct lwtunnel_encap_ops *ops;
 	int ret = -EINVAL;
 
 	if (encap_type == LWTUNNEL_ENCAP_NONE ||
-	    encap_type > LWTUNNEL_ENCAP_MAX)
+	    encap_type > LWTUNNEL_ENCAP_MAX) {
+		NL_SET_ERR_MSG(extack, "Unknown lwt encapsulation type");
 		return ret;
+	}
 
 	rcu_read_lock();
 	ops = rcu_dereference(lwtun_encaps[encap_type]);
@@ -153,11 +155,16 @@ int lwtunnel_valid_encap_type(u16 encap_type)
 		}
 	}
 #endif
-	return ops ? 0 : -EOPNOTSUPP;
+	ret = ops ? 0 : -EOPNOTSUPP;
+	if (ret < 0)
+		NL_SET_ERR_MSG(extack, "lwt encapsulation type not supported");
+
+	return ret;
 }
 EXPORT_SYMBOL(lwtunnel_valid_encap_type);
 
-int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining)
+int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining,
+				   struct netlink_ext_ack *extack)
 {
 	struct rtnexthop *rtnh = (struct rtnexthop *)attr;
 	struct nlattr *nla_entype;
@@ -174,7 +181,8 @@ int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining)
 			if (nla_entype) {
 				encap_type = nla_get_u16(nla_entype);
 
-				if (lwtunnel_valid_encap_type(encap_type) != 0)
+				if (lwtunnel_valid_encap_type(encap_type,
+							      extack) != 0)
 					return -EOPNOTSUPP;
 			}
 		}
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 715b7967d8ea..4e678fa892dd 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -685,7 +685,8 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 			break;
 		case RTA_MULTIPATH:
 			err = lwtunnel_valid_encap_type_attr(nla_data(attr),
-							     nla_len(attr));
+							     nla_len(attr),
+							     extack);
 			if (err < 0)
 				goto errout;
 			cfg->fc_mp = nla_data(attr);
@@ -702,7 +703,8 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
 			break;
 		case RTA_ENCAP_TYPE:
 			cfg->fc_encap_type = nla_get_u16(attr);
-			err = lwtunnel_valid_encap_type(cfg->fc_encap_type);
+			err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
+							extack);
 			if (err < 0)
 				goto errout;
 			break;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2fe84bdc4e60..524a76b5206e 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3016,7 +3016,7 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
 		cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
 
 		err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
-						     cfg->fc_mp_len);
+						     cfg->fc_mp_len, extack);
 		if (err < 0)
 			goto errout;
 	}
@@ -3035,7 +3035,7 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (tb[RTA_ENCAP_TYPE]) {
 		cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
 
-		err = lwtunnel_valid_encap_type(cfg->fc_encap_type);
+		err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
 		if (err < 0)
 			goto errout;
 	}
-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 4/9] net: add extack arg to lwtunnel build state

[David Ahern]

Pass extack arg down to lwtunnel_build_state and the build_state callbacks.
Add messages for failures in lwtunnel_build_state, and add the extarg to
nla_parse where possible in the build_state callbacks.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 include/linux/netlink.h   | 10 ++++++++++
 include/net/lwtunnel.h    |  9 ++++++---
 net/core/lwt_bpf.c        |  5 +++--
 net/core/lwtunnel.c       | 20 +++++++++++++++++---
 net/ipv4/fib_lookup.h     |  3 ++-
 net/ipv4/fib_semantics.c  | 20 +++++++++++---------
 net/ipv4/fib_trie.c       |  2 +-
 net/ipv4/ip_tunnel_core.c | 11 +++++++----
 net/ipv6/ila/ila_lwt.c    |  5 +++--
 net/ipv6/route.c          |  2 +-
 net/ipv6/seg6_iptunnel.c  |  5 +++--
 net/mpls/mpls_iptunnel.c  |  5 +++--
 12 files changed, 67 insertions(+), 30 deletions(-)

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index a68aad484c69..8664fd26eb5d 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -102,6 +102,16 @@ struct netlink_ext_ack {
 		(extack)->bad_attr = (attr);		\
 } while (0)
 
+#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) do {	\
+	static const char __msg[] = (msg);		\
+	struct netlink_ext_ack *__extack = (extack);	\
+							\
+	if (__extack) {					\
+		__extack->_msg = __msg;			\
+		__extack->bad_attr = (attr);		\
+	}						\
+} while (0)
+
 extern void netlink_kernel_release(struct sock *sk);
 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h
index ca6f002774ef..7c26863b8cf4 100644
--- a/include/net/lwtunnel.h
+++ b/include/net/lwtunnel.h
@@ -35,7 +35,8 @@ struct lwtunnel_state {
 struct lwtunnel_encap_ops {
 	int (*build_state)(struct nlattr *encap,
 			   unsigned int family, const void *cfg,
-			   struct lwtunnel_state **ts);
+			   struct lwtunnel_state **ts,
+			   struct netlink_ext_ack *extack);
 	void (*destroy_state)(struct lwtunnel_state *lws);
 	int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
 	int (*input)(struct sk_buff *skb);
@@ -114,7 +115,8 @@ int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
 int lwtunnel_build_state(u16 encap_type,
 			 struct nlattr *encap,
 			 unsigned int family, const void *cfg,
-			 struct lwtunnel_state **lws);
+			 struct lwtunnel_state **lws,
+			 struct netlink_ext_ack *extack);
 int lwtunnel_fill_encap(struct sk_buff *skb,
 			struct lwtunnel_state *lwtstate);
 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
@@ -192,7 +194,8 @@ static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
 static inline int lwtunnel_build_state(u16 encap_type,
 				       struct nlattr *encap,
 				       unsigned int family, const void *cfg,
-				       struct lwtunnel_state **lws)
+				       struct lwtunnel_state **lws,
+				       struct netlink_ext_ack *extack)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
index b3bc0a31af9f..1307731ddfe4 100644
--- a/net/core/lwt_bpf.c
+++ b/net/core/lwt_bpf.c
@@ -240,7 +240,8 @@ static const struct nla_policy bpf_nl_policy[LWT_BPF_MAX + 1] = {
 
 static int bpf_build_state(struct nlattr *nla,
 			   unsigned int family, const void *cfg,
-			   struct lwtunnel_state **ts)
+			   struct lwtunnel_state **ts,
+			   struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb[LWT_BPF_MAX + 1];
 	struct lwtunnel_state *newts;
@@ -250,7 +251,7 @@ static int bpf_build_state(struct nlattr *nla,
 	if (family != AF_INET && family != AF_INET6)
 		return -EAFNOSUPPORT;
 
-	ret = nla_parse_nested(tb, LWT_BPF_MAX, nla, bpf_nl_policy, NULL);
+	ret = nla_parse_nested(tb, LWT_BPF_MAX, nla, bpf_nl_policy, extack);
 	if (ret < 0)
 		return ret;
 
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
index ab840386a74d..d9cb3532f1dd 100644
--- a/net/core/lwtunnel.c
+++ b/net/core/lwtunnel.c
@@ -103,25 +103,39 @@ EXPORT_SYMBOL(lwtunnel_encap_del_ops);
 
 int lwtunnel_build_state(u16 encap_type,
 			 struct nlattr *encap, unsigned int family,
-			 const void *cfg, struct lwtunnel_state **lws)
+			 const void *cfg, struct lwtunnel_state **lws,
+			 struct netlink_ext_ack *extack)
 {
 	const struct lwtunnel_encap_ops *ops;
+	bool found = false;
 	int ret = -EINVAL;
 
 	if (encap_type == LWTUNNEL_ENCAP_NONE ||
-	    encap_type > LWTUNNEL_ENCAP_MAX)
+	    encap_type > LWTUNNEL_ENCAP_MAX) {
+		NL_SET_ERR_MSG_ATTR(extack, encap,
+				    "Unknown LWT encapsulation type");
 		return ret;
+	}
 
 	ret = -EOPNOTSUPP;
 	rcu_read_lock();
 	ops = rcu_dereference(lwtun_encaps[encap_type]);
 	if (likely(ops && ops->build_state && try_module_get(ops->owner))) {
-		ret = ops->build_state(encap, family, cfg, lws);
+		found = true;
+		ret = ops->build_state(encap, family, cfg, lws, extack);
 		if (ret)
 			module_put(ops->owner);
 	}
 	rcu_read_unlock();
 
+	/* don't rely on -EOPNOTSUPP to detect match as build_state
+	 * handlers could return it
+	 */
+	if (!found) {
+		NL_SET_ERR_MSG_ATTR(extack, encap,
+				    "LWT encapsulation type not supported");
+	}
+
 	return ret;
 }
 EXPORT_SYMBOL(lwtunnel_build_state);
diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h
index 2704e08545da..769ab87ebc4b 100644
--- a/net/ipv4/fib_lookup.h
+++ b/net/ipv4/fib_lookup.h
@@ -30,7 +30,8 @@ static inline void fib_alias_accessed(struct fib_alias *fa)
 void fib_release_info(struct fib_info *);
 struct fib_info *fib_create_info(struct fib_config *cfg,
 				 struct netlink_ext_ack *extack);
-int fib_nh_match(struct fib_config *cfg, struct fib_info *fi);
+int fib_nh_match(struct fib_config *cfg, struct fib_info *fi,
+		 struct netlink_ext_ack *extack);
 int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, u32 tb_id,
 		  u8 type, __be32 dst, int dst_len, u8 tos, struct fib_info *fi,
 		  unsigned int);
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 4852e183afe0..89e8fcc8449b 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -530,7 +530,7 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
 				ret = lwtunnel_build_state(nla_get_u16(
 							   nla_entype),
 							   nla,  AF_INET, cfg,
-							   &lwtstate);
+							   &lwtstate, extack);
 				if (ret)
 					goto errout;
 				nexthop_nh->nh_lwtstate =
@@ -612,7 +612,8 @@ static inline void fib_add_weight(struct fib_info *fi,
 static int fib_encap_match(u16 encap_type,
 			   struct nlattr *encap,
 			   const struct fib_nh *nh,
-			   const struct fib_config *cfg)
+			   const struct fib_config *cfg,
+			   struct netlink_ext_ack *extack)
 {
 	struct lwtunnel_state *lwtstate;
 	int ret, result = 0;
@@ -620,8 +621,8 @@ static int fib_encap_match(u16 encap_type,
 	if (encap_type == LWTUNNEL_ENCAP_NONE)
 		return 0;
 
-	ret = lwtunnel_build_state(encap_type, encap,
-				   AF_INET, cfg, &lwtstate);
+	ret = lwtunnel_build_state(encap_type, encap, AF_INET,
+				   cfg, &lwtstate, extack);
 	if (!ret) {
 		result = lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate);
 		lwtstate_free(lwtstate);
@@ -630,7 +631,8 @@ static int fib_encap_match(u16 encap_type,
 	return result;
 }
 
-int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
+int fib_nh_match(struct fib_config *cfg, struct fib_info *fi,
+		 struct netlink_ext_ack *extack)
 {
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	struct rtnexthop *rtnh;
@@ -642,9 +644,9 @@ int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
 
 	if (cfg->fc_oif || cfg->fc_gw) {
 		if (cfg->fc_encap) {
-			if (fib_encap_match(cfg->fc_encap_type,
-					    cfg->fc_encap, fi->fib_nh, cfg))
-			    return 1;
+			if (fib_encap_match(cfg->fc_encap_type, cfg->fc_encap,
+					    fi->fib_nh, cfg, extack))
+				return 1;
 		}
 		if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) &&
 		    (!cfg->fc_gw  || cfg->fc_gw == fi->fib_nh->nh_gw))
@@ -1145,7 +1147,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
 			}
 			err = lwtunnel_build_state(cfg->fc_encap_type,
 						   cfg->fc_encap, AF_INET, cfg,
-						   &lwtstate);
+						   &lwtstate, extack);
 			if (err)
 				goto failure;
 
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index a624d380c81d..d56659e97a6e 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1562,7 +1562,7 @@ int fib_table_delete(struct net *net, struct fib_table *tb,
 		     fi->fib_prefsrc == cfg->fc_prefsrc) &&
 		    (!cfg->fc_protocol ||
 		     fi->fib_protocol == cfg->fc_protocol) &&
-		    fib_nh_match(cfg, fi) == 0) {
+		    fib_nh_match(cfg, fi, extack) == 0) {
 			fa_to_delete = fa;
 			break;
 		}
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index baf196eaf1d8..90e11479c725 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -228,14 +228,16 @@ static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
 
 static int ip_tun_build_state(struct nlattr *attr,
 			      unsigned int family, const void *cfg,
-			      struct lwtunnel_state **ts)
+			      struct lwtunnel_state **ts,
+			      struct netlink_ext_ack *extack)
 {
 	struct ip_tunnel_info *tun_info;
 	struct lwtunnel_state *new_state;
 	struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
 	int err;
 
-	err = nla_parse_nested(tb, LWTUNNEL_IP_MAX, attr, ip_tun_policy, NULL);
+	err = nla_parse_nested(tb, LWTUNNEL_IP_MAX, attr, ip_tun_policy,
+			       extack);
 	if (err < 0)
 		return err;
 
@@ -325,7 +327,8 @@ static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
 
 static int ip6_tun_build_state(struct nlattr *attr,
 			       unsigned int family, const void *cfg,
-			       struct lwtunnel_state **ts)
+			       struct lwtunnel_state **ts,
+			       struct netlink_ext_ack *extack)
 {
 	struct ip_tunnel_info *tun_info;
 	struct lwtunnel_state *new_state;
@@ -333,7 +336,7 @@ static int ip6_tun_build_state(struct nlattr *attr,
 	int err;
 
 	err = nla_parse_nested(tb, LWTUNNEL_IP6_MAX, attr, ip6_tun_policy,
-			       NULL);
+			       extack);
 	if (err < 0)
 		return err;
 
diff --git a/net/ipv6/ila/ila_lwt.c b/net/ipv6/ila/ila_lwt.c
index f4a413aba423..0c02a09bc351 100644
--- a/net/ipv6/ila/ila_lwt.c
+++ b/net/ipv6/ila/ila_lwt.c
@@ -117,7 +117,8 @@ static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
 
 static int ila_build_state(struct nlattr *nla,
 			   unsigned int family, const void *cfg,
-			   struct lwtunnel_state **ts)
+			   struct lwtunnel_state **ts,
+			   struct netlink_ext_ack *extack)
 {
 	struct ila_lwt *ilwt;
 	struct ila_params *p;
@@ -146,7 +147,7 @@ static int ila_build_state(struct nlattr *nla,
 		return -EINVAL;
 	}
 
-	ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, NULL);
+	ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, extack);
 	if (ret < 0)
 		return ret;
 
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 524a76b5206e..9d9b5bbea153 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1939,7 +1939,7 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
 
 		err = lwtunnel_build_state(cfg->fc_encap_type,
 					   cfg->fc_encap, AF_INET6, cfg,
-					   &lwtstate);
+					   &lwtstate, extack);
 		if (err)
 			goto out;
 		rt->dst.lwtstate = lwtstate_get(lwtstate);
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index 6a495490d43e..264d772d3c7d 100644
--- a/net/ipv6/seg6_iptunnel.c
+++ b/net/ipv6/seg6_iptunnel.c
@@ -326,7 +326,8 @@ static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 
 static int seg6_build_state(struct nlattr *nla,
 			    unsigned int family, const void *cfg,
-			    struct lwtunnel_state **ts)
+			    struct lwtunnel_state **ts,
+			    struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb[SEG6_IPTUNNEL_MAX + 1];
 	struct seg6_iptunnel_encap *tuninfo;
@@ -336,7 +337,7 @@ static int seg6_build_state(struct nlattr *nla,
 	int err;
 
 	err = nla_parse_nested(tb, SEG6_IPTUNNEL_MAX, nla,
-			       seg6_iptunnel_policy, NULL);
+			       seg6_iptunnel_policy, extack);
 
 	if (err < 0)
 		return err;
diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
index 369c7a23c86c..15e1aa708e50 100644
--- a/net/mpls/mpls_iptunnel.c
+++ b/net/mpls/mpls_iptunnel.c
@@ -159,7 +159,8 @@ static int mpls_xmit(struct sk_buff *skb)
 
 static int mpls_build_state(struct nlattr *nla,
 			    unsigned int family, const void *cfg,
-			    struct lwtunnel_state **ts)
+			    struct lwtunnel_state **ts,
+			    struct netlink_ext_ack *extack)
 {
 	struct mpls_iptunnel_encap *tun_encap_info;
 	struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1];
@@ -168,7 +169,7 @@ static int mpls_build_state(struct nlattr *nla,
 	int ret;
 
 	ret = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla,
-			       mpls_iptunnel_policy, NULL);
+			       mpls_iptunnel_policy, extack);
 	if (ret < 0)
 		return ret;
 
-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 5/9] net: Fill in extack for mpls lwt encap

[David Ahern]

Fill in extack for errors in build_state for mpls lwt encap including
passing extack to nla_get_labels and adding error messages for failures
in it.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 net/mpls/af_mpls.c       | 49 ++++++++++++++++++++++++++++++++++++++----------
 net/mpls/internal.h      |  2 +-
 net/mpls/mpls_iptunnel.c | 12 +++++++-----
 3 files changed, 47 insertions(+), 16 deletions(-)

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 257ec66009da..f3830951fb1c 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -728,8 +728,8 @@ static int mpls_nh_build(struct net *net, struct mpls_route *rt,
 		goto errout;
 
 	if (newdst) {
-		err = nla_get_labels(newdst, max_labels,
-				     &nh->nh_labels, nh->nh_label);
+		err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
+				     nh->nh_label, NULL);
 		if (err)
 			goto errout;
 	}
@@ -782,7 +782,8 @@ static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
 
 		nla = nla_find(attrs, attrlen, RTA_NEWDST);
 		if (nla &&
-		    nla_get_labels(nla, MAX_NEW_LABELS, &n_labels, NULL) != 0)
+		    nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
+				   NULL, NULL) != 0)
 			return 0;
 
 		*max_labels = max_t(u8, *max_labels, n_labels);
@@ -1541,8 +1542,8 @@ int nla_put_labels(struct sk_buff *skb, int attrtype,
 }
 EXPORT_SYMBOL_GPL(nla_put_labels);
 
-int nla_get_labels(const struct nlattr *nla,
-		   u8 max_labels, u8 *labels, u32 label[])
+int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
+		   u32 label[], struct netlink_ext_ack *extack)
 {
 	unsigned len = nla_len(nla);
 	struct mpls_shim_hdr *nla_label;
@@ -1553,13 +1554,18 @@ int nla_get_labels(const struct nlattr *nla,
 	/* len needs to be an even multiple of 4 (the label size). Number
 	 * of labels is a u8 so check for overflow.
 	 */
-	if (len & 3 || len / 4 > 255)
+	if (len & 3 || len / 4 > 255) {
+		NL_SET_ERR_MSG_ATTR(extack, nla,
+				    "Invalid length for labels attribute");
 		return -EINVAL;
+	}
 
 	/* Limit the number of new labels allowed */
 	nla_labels = len/4;
-	if (nla_labels > max_labels)
+	if (nla_labels > max_labels) {
+		NL_SET_ERR_MSG(extack, "Too many labels");
 		return -EINVAL;
+	}
 
 	/* when label == NULL, caller wants number of labels */
 	if (!label)
@@ -1574,8 +1580,29 @@ int nla_get_labels(const struct nlattr *nla,
 		/* Ensure the bottom of stack flag is properly set
 		 * and ttl and tc are both clear.
 		 */
-		if ((dec.bos != bos) || dec.ttl || dec.tc)
+		if (dec.ttl) {
+			NL_SET_ERR_MSG_ATTR(extack, nla,
+					    "TTL in label must be 0");
+			return -EINVAL;
+		}
+
+		if (dec.tc) {
+			NL_SET_ERR_MSG_ATTR(extack, nla,
+					    "Traffic class in label must be 0");
 			return -EINVAL;
+		}
+
+		if (dec.bos != bos) {
+			NL_SET_BAD_ATTR(extack, nla);
+			if (bos) {
+				NL_SET_ERR_MSG(extack,
+					       "BOS bit must be set in first label");
+			} else {
+				NL_SET_ERR_MSG(extack,
+					       "BOS bit can only be set in first label");
+			}
+			return -EINVAL;
+		}
 
 		switch (dec.label) {
 		case MPLS_LABEL_IMPLNULL:
@@ -1583,6 +1610,8 @@ int nla_get_labels(const struct nlattr *nla,
 			 * assign and distribute, but which never
 			 * actually appears in the encapsulation.
 			 */
+			NL_SET_ERR_MSG_ATTR(extack, nla,
+					    "Implicit NULL Label (3) can not be used in encapsulation");
 			return -EINVAL;
 		}
 
@@ -1696,14 +1725,14 @@ static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
 		case RTA_NEWDST:
 			if (nla_get_labels(nla, MAX_NEW_LABELS,
 					   &cfg->rc_output_labels,
-					   cfg->rc_output_label))
+					   cfg->rc_output_label, NULL))
 				goto errout;
 			break;
 		case RTA_DST:
 		{
 			u8 label_count;
 			if (nla_get_labels(nla, 1, &label_count,
-					   &cfg->rc_label))
+					   &cfg->rc_label, NULL))
 				goto errout;
 
 			/* Reserved labels may not be set */
diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index 4db6a5971322..e59f299ceb3f 100644
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -203,7 +203,7 @@ static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
 int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
 		   const u32 label[]);
 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
-		   u32 label[]);
+		   u32 label[], struct netlink_ext_ack *extack);
 int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
 		u8 via[]);
 bool mpls_output_possible(const struct net_device *dev);
diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
index 15e1aa708e50..6e558a419f60 100644
--- a/net/mpls/mpls_iptunnel.c
+++ b/net/mpls/mpls_iptunnel.c
@@ -173,13 +173,14 @@ static int mpls_build_state(struct nlattr *nla,
 	if (ret < 0)
 		return ret;
 
-	if (!tb[MPLS_IPTUNNEL_DST])
+	if (!tb[MPLS_IPTUNNEL_DST]) {
+		NL_SET_ERR_MSG(extack, "MPLS_IPTUNNEL_DST attribute is missing");
 		return -EINVAL;
-
+	}
 
 	/* determine number of labels */
-	if (nla_get_labels(tb[MPLS_IPTUNNEL_DST],
-			   MAX_NEW_LABELS, &n_labels, NULL))
+	if (nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS,
+			   &n_labels, NULL, extack))
 		return -EINVAL;
 
 	newts = lwtunnel_state_alloc(sizeof(*tun_encap_info) +
@@ -189,7 +190,8 @@ static int mpls_build_state(struct nlattr *nla,
 
 	tun_encap_info = mpls_lwtunnel_encap(newts);
 	ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], n_labels,
-			     &tun_encap_info->labels, tun_encap_info->label);
+			     &tun_encap_info->labels, tun_encap_info->label,
+			     extack);
 	if (ret)
 		goto errout;
 
-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 6/9] net: mpls: Pull common label check into helper

[David Ahern]

mpls_route_add and mpls_route_del have the same checks on the label.
Move to a helper. Avoid duplicate extack messages in the next patch.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 net/mpls/af_mpls.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index f3830951fb1c..726eafecc793 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -856,6 +856,19 @@ static int mpls_nh_build_multi(struct mpls_route_config *cfg,
 	return err;
 }
 
+static bool mpls_label_ok(struct net *net, unsigned int index)
+{
+	/* Reserved labels may not be set */
+	if (index < MPLS_LABEL_FIRST_UNRESERVED)
+		return false;
+
+	/* The full 20 bit range may not be supported. */
+	if (index >= net->mpls.platform_labels)
+		return false;
+
+	return true;
+}
+
 static int mpls_route_add(struct mpls_route_config *cfg)
 {
 	struct mpls_route __rcu **platform_label;
@@ -875,12 +888,7 @@ static int mpls_route_add(struct mpls_route_config *cfg)
 		index = find_free_label(net);
 	}
 
-	/* Reserved labels may not be set */
-	if (index < MPLS_LABEL_FIRST_UNRESERVED)
-		goto errout;
-
-	/* The full 20 bit range may not be supported. */
-	if (index >= net->mpls.platform_labels)
+	if (!mpls_label_ok(net, index))
 		goto errout;
 
 	/* Append makes no sense with mpls */
@@ -952,12 +960,7 @@ static int mpls_route_del(struct mpls_route_config *cfg)
 
 	index = cfg->rc_label;
 
-	/* Reserved labels may not be removed */
-	if (index < MPLS_LABEL_FIRST_UNRESERVED)
-		goto errout;
-
-	/* The full 20 bit range may not be supported */
-	if (index >= net->mpls.platform_labels)
+	if (!mpls_label_ok(net, index))
 		goto errout;
 
 	mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
@@ -1735,10 +1738,9 @@ static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
 					   &cfg->rc_label, NULL))
 				goto errout;
 
-			/* Reserved labels may not be set */
-			if (cfg->rc_label < MPLS_LABEL_FIRST_UNRESERVED)
+			if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
+					   cfg->rc_label))
 				goto errout;
-
 			break;
 		}
 		case RTA_VIA:
-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 7/9] net: mpls: Add extack messages for route add and delete failures

[David Ahern]

Add error messages for failures in adding and deleting mpls routes.
This covers most of the annoying EINVAL errors.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 net/mpls/af_mpls.c  | 125 ++++++++++++++++++++++++++++++++++++----------------
 net/mpls/internal.h |   2 +-
 2 files changed, 87 insertions(+), 40 deletions(-)

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 726eafecc793..0133d1ad9032 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -720,7 +720,8 @@ static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
 
 static int mpls_nh_build(struct net *net, struct mpls_route *rt,
 			 struct mpls_nh *nh, int oif, struct nlattr *via,
-			 struct nlattr *newdst, u8 max_labels)
+			 struct nlattr *newdst, u8 max_labels,
+			 struct netlink_ext_ack *extack)
 {
 	int err = -ENOMEM;
 
@@ -729,14 +730,14 @@ static int mpls_nh_build(struct net *net, struct mpls_route *rt,
 
 	if (newdst) {
 		err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
-				     nh->nh_label, NULL);
+				     nh->nh_label, extack);
 		if (err)
 			goto errout;
 	}
 
 	if (via) {
 		err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
-				  __mpls_nh_via(rt, nh));
+				  __mpls_nh_via(rt, nh), extack);
 		if (err)
 			goto errout;
 	} else {
@@ -803,7 +804,8 @@ static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
 }
 
 static int mpls_nh_build_multi(struct mpls_route_config *cfg,
-			       struct mpls_route *rt, u8 max_labels)
+			       struct mpls_route *rt, u8 max_labels,
+			       struct netlink_ext_ack *extack)
 {
 	struct rtnexthop *rtnh = cfg->rc_mp;
 	struct nlattr *nla_via, *nla_newdst;
@@ -837,7 +839,7 @@ static int mpls_nh_build_multi(struct mpls_route_config *cfg,
 
 		err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
 				    rtnh->rtnh_ifindex, nla_via, nla_newdst,
-				    max_labels);
+				    max_labels, extack);
 		if (err)
 			goto errout;
 
@@ -856,20 +858,28 @@ static int mpls_nh_build_multi(struct mpls_route_config *cfg,
 	return err;
 }
 
-static bool mpls_label_ok(struct net *net, unsigned int index)
+static bool mpls_label_ok(struct net *net, unsigned int index,
+			  struct netlink_ext_ack *extack)
 {
 	/* Reserved labels may not be set */
-	if (index < MPLS_LABEL_FIRST_UNRESERVED)
+	if (index < MPLS_LABEL_FIRST_UNRESERVED) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
 		return false;
+	}
 
 	/* The full 20 bit range may not be supported. */
-	if (index >= net->mpls.platform_labels)
+	if (index >= net->mpls.platform_labels) {
+		NL_SET_ERR_MSG(extack,
+			       "Label >= configured maximum in platform_labels");
 		return false;
+	}
 
 	return true;
 }
 
-static int mpls_route_add(struct mpls_route_config *cfg)
+static int mpls_route_add(struct mpls_route_config *cfg,
+			  struct netlink_ext_ack *extack)
 {
 	struct mpls_route __rcu **platform_label;
 	struct net *net = cfg->rc_nlinfo.nl_net;
@@ -888,13 +898,15 @@ static int mpls_route_add(struct mpls_route_config *cfg)
 		index = find_free_label(net);
 	}
 
-	if (!mpls_label_ok(net, index))
+	if (!mpls_label_ok(net, index, extack))
 		goto errout;
 
 	/* Append makes no sense with mpls */
 	err = -EOPNOTSUPP;
-	if (cfg->rc_nlflags & NLM_F_APPEND)
+	if (cfg->rc_nlflags & NLM_F_APPEND) {
+		NL_SET_ERR_MSG(extack, "MPLS does not support route append");
 		goto errout;
+	}
 
 	err = -EEXIST;
 	platform_label = rtnl_dereference(net->mpls.platform_label);
@@ -921,8 +933,10 @@ static int mpls_route_add(struct mpls_route_config *cfg)
 		nhs = 1;
 	}
 
-	if (nhs == 0)
+	if (nhs == 0) {
+		NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
 		goto errout;
+	}
 
 	err = -ENOMEM;
 	rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
@@ -936,7 +950,7 @@ static int mpls_route_add(struct mpls_route_config *cfg)
 	rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
 
 	if (cfg->rc_mp)
-		err = mpls_nh_build_multi(cfg, rt, max_labels);
+		err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
 	else
 		err = mpls_nh_build_from_cfg(cfg, rt);
 	if (err)
@@ -952,7 +966,8 @@ static int mpls_route_add(struct mpls_route_config *cfg)
 	return err;
 }
 
-static int mpls_route_del(struct mpls_route_config *cfg)
+static int mpls_route_del(struct mpls_route_config *cfg,
+			  struct netlink_ext_ack *extack)
 {
 	struct net *net = cfg->rc_nlinfo.nl_net;
 	unsigned index;
@@ -960,7 +975,7 @@ static int mpls_route_del(struct mpls_route_config *cfg)
 
 	index = cfg->rc_label;
 
-	if (!mpls_label_ok(net, index))
+	if (!mpls_label_ok(net, index, extack))
 		goto errout;
 
 	mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
@@ -1626,19 +1641,25 @@ int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
 }
 EXPORT_SYMBOL_GPL(nla_get_labels);
 
-int nla_get_via(const struct nlattr *nla, u8 *via_alen,
-		u8 *via_table, u8 via_addr[])
+int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
+		u8 via_addr[], struct netlink_ext_ack *extack)
 {
 	struct rtvia *via = nla_data(nla);
 	int err = -EINVAL;
 	int alen;
 
-	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
+	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
+		NL_SET_ERR_MSG_ATTR(extack, nla,
+				    "Invalid attribute length for RTA_VIA");
 		goto errout;
+	}
 	alen = nla_len(nla) -
 			offsetof(struct rtvia, rtvia_addr);
-	if (alen > MAX_VIA_ALEN)
+	if (alen > MAX_VIA_ALEN) {
+		NL_SET_ERR_MSG_ATTR(extack, nla,
+				    "Invalid address length for RTA_VIA");
 		goto errout;
+	}
 
 	/* Validate the address family */
 	switch (via->rtvia_family) {
@@ -1668,8 +1689,10 @@ int nla_get_via(const struct nlattr *nla, u8 *via_alen,
 	return err;
 }
 
-static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
-			       struct mpls_route_config *cfg)
+static int rtm_to_route_config(struct sk_buff *skb,
+			       struct nlmsghdr *nlh,
+			       struct mpls_route_config *cfg,
+			       struct netlink_ext_ack *extack)
 {
 	struct rtmsg *rtm;
 	struct nlattr *tb[RTA_MAX+1];
@@ -1677,35 +1700,54 @@ static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
 	int err;
 
 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy,
-			  NULL);
+			  extack);
 	if (err < 0)
 		goto errout;
 
 	err = -EINVAL;
 	rtm = nlmsg_data(nlh);
 
-	if (rtm->rtm_family != AF_MPLS)
+	if (rtm->rtm_family != AF_MPLS) {
+		NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
 		goto errout;
-	if (rtm->rtm_dst_len != 20)
+	}
+	if (rtm->rtm_dst_len != 20) {
+		NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
 		goto errout;
-	if (rtm->rtm_src_len != 0)
+	}
+	if (rtm->rtm_src_len != 0) {
+		NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
 		goto errout;
-	if (rtm->rtm_tos != 0)
+	}
+	if (rtm->rtm_tos != 0) {
+		NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
 		goto errout;
-	if (rtm->rtm_table != RT_TABLE_MAIN)
+	}
+	if (rtm->rtm_table != RT_TABLE_MAIN) {
+		NL_SET_ERR_MSG(extack,
+			       "MPLS only supports the main route table");
 		goto errout;
+	}
 	/* Any value is acceptable for rtm_protocol */
 
 	/* As mpls uses destination specific addresses
 	 * (or source specific address in the case of multicast)
 	 * all addresses have universal scope.
 	 */
-	if (rtm->rtm_scope != RT_SCOPE_UNIVERSE)
+	if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid route scope  - MPLS only supports UNIVERSE");
 		goto errout;
-	if (rtm->rtm_type != RTN_UNICAST)
+	}
+	if (rtm->rtm_type != RTN_UNICAST) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid route type - MPLS only supports UNICAST");
 		goto errout;
-	if (rtm->rtm_flags != 0)
+	}
+	if (rtm->rtm_flags != 0) {
+		NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
 		goto errout;
+	}
 
 	cfg->rc_label		= LABEL_NOT_SPECIFIED;
 	cfg->rc_protocol	= rtm->rtm_protocol;
@@ -1728,25 +1770,26 @@ static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
 		case RTA_NEWDST:
 			if (nla_get_labels(nla, MAX_NEW_LABELS,
 					   &cfg->rc_output_labels,
-					   cfg->rc_output_label, NULL))
+					   cfg->rc_output_label, extack))
 				goto errout;
 			break;
 		case RTA_DST:
 		{
 			u8 label_count;
 			if (nla_get_labels(nla, 1, &label_count,
-					   &cfg->rc_label, NULL))
+					   &cfg->rc_label, extack))
 				goto errout;
 
 			if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
-					   cfg->rc_label))
+					   cfg->rc_label, extack))
 				goto errout;
 			break;
 		}
 		case RTA_VIA:
 		{
 			if (nla_get_via(nla, &cfg->rc_via_alen,
-					&cfg->rc_via_table, cfg->rc_via))
+					&cfg->rc_via_table, cfg->rc_via,
+					extack))
 				goto errout;
 			break;
 		}
@@ -1760,14 +1803,18 @@ static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
 		{
 			u8 ttl_propagate = nla_get_u8(nla);
 
-			if (ttl_propagate > 1)
+			if (ttl_propagate > 1) {
+				NL_SET_ERR_MSG_ATTR(extack, nla,
+						    "RTA_TTL_PROPAGATE can only be 0 or 1");
 				goto errout;
+			}
 			cfg->rc_ttl_propagate = ttl_propagate ?
 				MPLS_TTL_PROP_ENABLED :
 				MPLS_TTL_PROP_DISABLED;
 			break;
 		}
 		default:
+			NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
 			/* Unsupported attribute */
 			goto errout;
 		}
@@ -1788,11 +1835,11 @@ static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (!cfg)
 		return -ENOMEM;
 
-	err = rtm_to_route_config(skb, nlh, cfg);
+	err = rtm_to_route_config(skb, nlh, cfg, extack);
 	if (err < 0)
 		goto out;
 
-	err = mpls_route_del(cfg);
+	err = mpls_route_del(cfg, extack);
 out:
 	kfree(cfg);
 
@@ -1810,11 +1857,11 @@ static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (!cfg)
 		return -ENOMEM;
 
-	err = rtm_to_route_config(skb, nlh, cfg);
+	err = rtm_to_route_config(skb, nlh, cfg, extack);
 	if (err < 0)
 		goto out;
 
-	err = mpls_route_add(cfg);
+	err = mpls_route_add(cfg, extack);
 out:
 	kfree(cfg);
 
diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index e59f299ceb3f..a015a6a1143b 100644
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -205,7 +205,7 @@ int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
 		   u32 label[], struct netlink_ext_ack *extack);
 int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
-		u8 via[]);
+		u8 via[], struct netlink_ext_ack *extack);
 bool mpls_output_possible(const struct net_device *dev);
 unsigned int mpls_dev_mtu(const struct net_device *dev);
 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 8/9] net: mpls: Make nla_get_via in af_mpls.c

[David Ahern]

nla_get_via is only used in af_mpls.c. Remove declaration from internal.h
and move up in af_mpls.c before first use. Code move only; no
functional change intended.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 net/mpls/af_mpls.c  | 96 ++++++++++++++++++++++++++---------------------------
 net/mpls/internal.h |  2 --
 2 files changed, 48 insertions(+), 50 deletions(-)

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 0133d1ad9032..a953fcf169ba 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -684,6 +684,54 @@ static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
 	return err;
 }
 
+static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
+		       u8 via_addr[], struct netlink_ext_ack *extack)
+{
+	struct rtvia *via = nla_data(nla);
+	int err = -EINVAL;
+	int alen;
+
+	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
+		NL_SET_ERR_MSG_ATTR(extack, nla,
+				    "Invalid attribute length for RTA_VIA");
+		goto errout;
+	}
+	alen = nla_len(nla) -
+			offsetof(struct rtvia, rtvia_addr);
+	if (alen > MAX_VIA_ALEN) {
+		NL_SET_ERR_MSG_ATTR(extack, nla,
+				    "Invalid address length for RTA_VIA");
+		goto errout;
+	}
+
+	/* Validate the address family */
+	switch (via->rtvia_family) {
+	case AF_PACKET:
+		*via_table = NEIGH_LINK_TABLE;
+		break;
+	case AF_INET:
+		*via_table = NEIGH_ARP_TABLE;
+		if (alen != 4)
+			goto errout;
+		break;
+	case AF_INET6:
+		*via_table = NEIGH_ND_TABLE;
+		if (alen != 16)
+			goto errout;
+		break;
+	default:
+		/* Unsupported address family */
+		goto errout;
+	}
+
+	memcpy(via_addr, via->rtvia_addr, alen);
+	*via_alen = alen;
+	err = 0;
+
+errout:
+	return err;
+}
+
 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
 				  struct mpls_route *rt)
 {
@@ -1641,54 +1689,6 @@ int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
 }
 EXPORT_SYMBOL_GPL(nla_get_labels);
 
-int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
-		u8 via_addr[], struct netlink_ext_ack *extack)
-{
-	struct rtvia *via = nla_data(nla);
-	int err = -EINVAL;
-	int alen;
-
-	if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
-		NL_SET_ERR_MSG_ATTR(extack, nla,
-				    "Invalid attribute length for RTA_VIA");
-		goto errout;
-	}
-	alen = nla_len(nla) -
-			offsetof(struct rtvia, rtvia_addr);
-	if (alen > MAX_VIA_ALEN) {
-		NL_SET_ERR_MSG_ATTR(extack, nla,
-				    "Invalid address length for RTA_VIA");
-		goto errout;
-	}
-
-	/* Validate the address family */
-	switch (via->rtvia_family) {
-	case AF_PACKET:
-		*via_table = NEIGH_LINK_TABLE;
-		break;
-	case AF_INET:
-		*via_table = NEIGH_ARP_TABLE;
-		if (alen != 4)
-			goto errout;
-		break;
-	case AF_INET6:
-		*via_table = NEIGH_ND_TABLE;
-		if (alen != 16)
-			goto errout;
-		break;
-	default:
-		/* Unsupported address family */
-		goto errout;
-	}
-
-	memcpy(via_addr, via->rtvia_addr, alen);
-	*via_alen = alen;
-	err = 0;
-
-errout:
-	return err;
-}
-
 static int rtm_to_route_config(struct sk_buff *skb,
 			       struct nlmsghdr *nlh,
 			       struct mpls_route_config *cfg,
diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index a015a6a1143b..cf65aec2e551 100644
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -204,8 +204,6 @@ int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
 		   const u32 label[]);
 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
 		   u32 label[], struct netlink_ext_ack *extack);
-int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
-		u8 via[], struct netlink_ext_ack *extack);
 bool mpls_output_possible(const struct net_device *dev);
 unsigned int mpls_dev_mtu(const struct net_device *dev);
 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
-- 
2.11.0 (Apple Git-81)

[PATCH v2 net-next 9/9] net: mpls: remove unnecessary initialization of err

[David Ahern]

err is initialized to EINVAL and not used before it is set again.
Remove the unnecessary initialization.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 net/mpls/af_mpls.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index a953fcf169ba..94b3317232a6 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -743,8 +743,6 @@ static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
 	if (!nh)
 		return -ENOMEM;
 
-	err = -EINVAL;
-
 	nh->nh_labels = cfg->rc_output_labels;
 	for (i = 0; i < nh->nh_labels; i++)
 		nh->nh_label[i] = cfg->rc_output_label[i];
-- 
2.11.0 (Apple Git-81)

Re: [PATCH v2 net-next 3/9] net: lwtunnel: Add extack to encap attr validation

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 1040 bytes --]

Hi David,

[auto build test ERROR on net-next/master]

url:    https://github.com/0day-ci/linux/commits/David-Ahern/net-another-round-of-extack-handling-for-routing/20170528-062659
config: ia64-allmodconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 6.2.0
reproduce:
        wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=ia64 

Note: the linux-review/David-Ahern/net-another-round-of-extack-handling-for-routing/20170528-062659 HEAD 44d11f94ccbe86e1a088f83a49ef3ca473118ad8 builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

   ERROR: "ia64_delay_loop" [drivers/spi/spi-thunderx.ko] undefined!
>> ERROR: "ia64_delay_loop" [drivers/net/phy/mdio-cavium.ko] undefined!

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 47727 bytes --]

Re: [PATCH v2 net-next 3/9] net: lwtunnel: Add extack to encap attr validation

[David Ahern]

On 5/27/17 7:02 PM, kbuild test robot wrote:
> Hi David,
> 
> [auto build test ERROR on net-next/master]
> 
> url:    https://github.com/0day-ci/linux/commits/David-Ahern/net-another-round-of-extack-handling-for-routing/20170528-062659
> config: ia64-allmodconfig (attached as .config)
> compiler: ia64-linux-gcc (GCC) 6.2.0
> reproduce:
>         wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         make.cross ARCH=ia64 
> 
> Note: the linux-review/David-Ahern/net-another-round-of-extack-handling-for-routing/20170528-062659 HEAD 44d11f94ccbe86e1a088f83a49ef3ca473118ad8 builds fine.
>       It only hurts bisectibility.
> 
> All errors (new ones prefixed by >>):
> 
>    ERROR: "ia64_delay_loop" [drivers/spi/spi-thunderx.ko] undefined!
>>> ERROR: "ia64_delay_loop" [drivers/net/phy/mdio-cavium.ko] undefined!

Appears to be a false positive. I do not modify anything related to
delay loops and none of this code is arch specific.

kbuild guys: can you clarify?

Re: [PATCH v2 net-next 0/9] net: another round of extack handling for routing

[David Miller]

From: David Ahern <dsahern@gmail.com>
Date: Sat, 27 May 2017 16:19:24 -0600

> This set focuses on passing extack through lwtunnel and MPLS with
> additional catches for IPv4 route add and minor cleanups in MPLS
> encountered passing the extack arg around.
> 
> v2
> - mindful of bloat adding duplicate messages
>   + refactored prefix and prefix length checks in ipv4's fib_table_insert
>     and fib_table_del
>   + refactored label check in mpls
> 
> - split mpls cleanups into 2 patches
>   + move nla_get_via up in af_mpls to avoid forward declaration

Series applied, thanks David.