1 files changed, 114 insertions, 17 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7b73c7c161a9..ee841f00a6ec 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -78,14 +78,6 @@ struct listeners {
 /* state bits */
 #define NETLINK_S_CONGESTED		0x0
 
-/* flags */
-#define NETLINK_F_KERNEL_SOCKET		0x1
-#define NETLINK_F_RECV_PKTINFO		0x2
-#define NETLINK_F_BROADCAST_SEND_ERROR	0x4
-#define NETLINK_F_RECV_NO_ENOBUFS	0x8
-#define NETLINK_F_LISTEN_ALL_NSID	0x10
-#define NETLINK_F_CAP_ACK		0x20
-
 static inline int netlink_is_kernel(struct sock *sk)
 {
 	return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET;
@@ -96,6 +88,44 @@ EXPORT_SYMBOL_GPL(nl_table);
 
 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
 
+static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS];
+
+static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = {
+	"nlk_cb_mutex-ROUTE",
+	"nlk_cb_mutex-1",
+	"nlk_cb_mutex-USERSOCK",
+	"nlk_cb_mutex-FIREWALL",
+	"nlk_cb_mutex-SOCK_DIAG",
+	"nlk_cb_mutex-NFLOG",
+	"nlk_cb_mutex-XFRM",
+	"nlk_cb_mutex-SELINUX",
+	"nlk_cb_mutex-ISCSI",
+	"nlk_cb_mutex-AUDIT",
+	"nlk_cb_mutex-FIB_LOOKUP",
+	"nlk_cb_mutex-CONNECTOR",
+	"nlk_cb_mutex-NETFILTER",
+	"nlk_cb_mutex-IP6_FW",
+	"nlk_cb_mutex-DNRTMSG",
+	"nlk_cb_mutex-KOBJECT_UEVENT",
+	"nlk_cb_mutex-GENERIC",
+	"nlk_cb_mutex-17",
+	"nlk_cb_mutex-SCSITRANSPORT",
+	"nlk_cb_mutex-ECRYPTFS",
+	"nlk_cb_mutex-RDMA",
+	"nlk_cb_mutex-CRYPTO",
+	"nlk_cb_mutex-SMC",
+	"nlk_cb_mutex-23",
+	"nlk_cb_mutex-24",
+	"nlk_cb_mutex-25",
+	"nlk_cb_mutex-26",
+	"nlk_cb_mutex-27",
+	"nlk_cb_mutex-28",
+	"nlk_cb_mutex-29",
+	"nlk_cb_mutex-30",
+	"nlk_cb_mutex-31",
+	"nlk_cb_mutex-MAX_LINKS"
+};
+
 static int netlink_dump(struct sock *sk);
 static void netlink_skb_destructor(struct sk_buff *skb);
 
@@ -585,6 +615,9 @@ static int __netlink_create(struct net *net, struct socket *sock,
 	} else {
 		nlk->cb_mutex = &nlk->cb_def_mutex;
 		mutex_init(nlk->cb_mutex);
+		lockdep_set_class_and_name(nlk->cb_mutex,
+					   nlk_cb_mutex_keys + protocol,
+					   nlk_cb_mutex_key_strings[protocol]);
 	}
 	init_waitqueue_head(&nlk->wait);
 
@@ -1619,6 +1652,13 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
 			nlk->flags &= ~NETLINK_F_CAP_ACK;
 		err = 0;
 		break;
+	case NETLINK_EXT_ACK:
+		if (val)
+			nlk->flags |= NETLINK_F_EXT_ACK;
+		else
+			nlk->flags &= ~NETLINK_F_EXT_ACK;
+		err = 0;
+		break;
 	default:
 		err = -ENOPROTOOPT;
 	}
@@ -1703,6 +1743,15 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
 			return -EFAULT;
 		err = 0;
 		break;
+	case NETLINK_EXT_ACK:
+		if (len < sizeof(int))
+			return -EINVAL;
+		len = sizeof(int);
+		val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0;
+		if (put_user(len, optlen) || put_user(val, optval))
+			return -EFAULT;
+		err = 0;
+		break;
 	default:
 		err = -ENOPROTOOPT;
 	}
@@ -2234,21 +2283,44 @@ error_free:
 }
 EXPORT_SYMBOL(__netlink_dump_start);
 
-void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
+void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
+		 const struct netlink_ext_ack *extack)
 {
 	struct sk_buff *skb;
 	struct nlmsghdr *rep;
 	struct nlmsgerr *errmsg;
 	size_t payload = sizeof(*errmsg);
+	size_t tlvlen = 0;
 	struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk);
+	unsigned int flags = 0;
 
 	/* Error messages get the original request appened, unless the user
-	 * requests to cap the error message.
+	 * requests to cap the error message, and get extra error data if
+	 * requested.
 	 */
-	if (!(nlk->flags & NETLINK_F_CAP_ACK) && err)
-		payload += nlmsg_len(nlh);
+	if (err) {
+		if (!(nlk->flags & NETLINK_F_CAP_ACK))
+			payload += nlmsg_len(nlh);
+		else
+			flags |= NLM_F_CAPPED;
+		if (nlk->flags & NETLINK_F_EXT_ACK && extack) {
+			if (extack->_msg)
+				tlvlen += nla_total_size(strlen(extack->_msg) + 1);
+			if (extack->bad_attr)
+				tlvlen += nla_total_size(sizeof(u32));
+		}
+	} else {
+		flags |= NLM_F_CAPPED;
 
-	skb = nlmsg_new(payload, GFP_KERNEL);
+		if (nlk->flags & NETLINK_F_EXT_ACK &&
+		    extack && extack->cookie_len)
+			tlvlen += nla_total_size(extack->cookie_len);
+	}
+
+	if (tlvlen)
+		flags |= NLM_F_ACK_TLVS;
+
+	skb = nlmsg_new(payload + tlvlen, GFP_KERNEL);
 	if (!skb) {
 		struct sock *sk;
 
@@ -2264,17 +2336,42 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
 	}
 
 	rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
-			  NLMSG_ERROR, payload, 0);
+			  NLMSG_ERROR, payload, flags);
 	errmsg = nlmsg_data(rep);
 	errmsg->error = err;
 	memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
+
+	if (nlk->flags & NETLINK_F_EXT_ACK && extack) {
+		if (err) {
+			if (extack->_msg)
+				WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
+						       extack->_msg));
+			if (extack->bad_attr &&
+			    !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
+				     (u8 *)extack->bad_attr >= in_skb->data +
+							       in_skb->len))
+				WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
+						    (u8 *)extack->bad_attr -
+						    in_skb->data));
+		} else {
+			if (extack->cookie_len)
+				WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
+						extack->cookie_len,
+						extack->cookie));
+		}
+	}
+
+	nlmsg_end(skb, rep);
+
 	netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
 }
 EXPORT_SYMBOL(netlink_ack);
 
 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
-						     struct nlmsghdr *))
+						   struct nlmsghdr *,
+						   struct netlink_ext_ack *))
 {
+	struct netlink_ext_ack extack = {};
 	struct nlmsghdr *nlh;
 	int err;
 
@@ -2295,13 +2392,13 @@ int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
 		if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
 			goto ack;
 
-		err = cb(skb, nlh);
+		err = cb(skb, nlh, &extack);
 		if (err == -EINTR)
 			goto skip;
 
 ack:
 		if (nlh->nlmsg_flags & NLM_F_ACK || err)
-			netlink_ack(skb, nlh, err);
+			netlink_ack(skb, nlh, err, &extack);
 
 skip:
 		msglen = NLMSG_ALIGN(nlh->nlmsg_len);