NFC: llcp: Implement socket options

Some LLCP services (e.g. the validation ones) require some control over
the LLCP link parameters like the receive window (RW) or the MIU extension
(MIUX). This can only be done through socket options.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

net/nfc/llcp/llcp.h

@@ -104,6 +104,9 @@ struct nfc_llcp_sock {
 	u8 dsap;
 	char *service_name;
 	size_t service_name_len;
+	u8 rw;
+	u16 miux;
+
 
 	/* Remote link parameters */
 	u8 remote_rw;

net/nfc/llcp/sock.c

@@ -223,6 +223,121 @@ error:
 	return ret;
 }
 
+static int nfc_llcp_setsockopt(struct socket *sock, int level, int optname,
+			       char __user *optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
+	u32 opt;
+	int err = 0;
+
+	pr_debug("%p optname %d\n", sk, optname);
+
+	if (level != SOL_NFC)
+		return -ENOPROTOOPT;
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case NFC_LLCP_RW:
+		if (sk->sk_state == LLCP_CONNECTED ||
+		    sk->sk_state == LLCP_BOUND ||
+		    sk->sk_state == LLCP_LISTEN) {
+			err = -EINVAL;
+			break;
+		}
+
+		if (get_user(opt, (u32 __user *) optval)) {
+			err = -EFAULT;
+			break;
+		}
+
+		if (opt > LLCP_MAX_RW) {
+			err = -EINVAL;
+			break;
+		}
+
+		llcp_sock->rw = (u8) opt;
+
+		break;
+
+	case NFC_LLCP_MIUX:
+		if (sk->sk_state == LLCP_CONNECTED ||
+		    sk->sk_state == LLCP_BOUND ||
+		    sk->sk_state == LLCP_LISTEN) {
+			err = -EINVAL;
+			break;
+		}
+
+		if (get_user(opt, (u32 __user *) optval)) {
+			err = -EFAULT;
+			break;
+		}
+
+		if (opt > LLCP_MAX_MIUX) {
+			err = -EINVAL;
+			break;
+		}
+
+		llcp_sock->miux = (u16) opt;
+
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+
+	return err;
+}
+
+static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
+			       char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
+	int len, err = 0;
+
+	pr_debug("%p optname %d\n", sk, optname);
+
+	if (level != SOL_NFC)
+		return -ENOPROTOOPT;
+
+	if (get_user(len, optlen))
+		return -EFAULT;
+
+	len = min_t(u32, len, sizeof(u32));
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case NFC_LLCP_RW:
+		if (put_user(llcp_sock->rw, (u32 __user *) optval))
+			err = -EFAULT;
+
+		break;
+
+	case NFC_LLCP_MIUX:
+		if (put_user(llcp_sock->miux, (u32 __user *) optval))
+			err = -EFAULT;
+
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+
+	if (put_user(len, optlen))
+		return -EFAULT;
+
+	return err;
+}
+
 void nfc_llcp_accept_unlink(struct sock *sk)
 {
 	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
@@ -735,8 +850,8 @@ static const struct proto_ops llcp_sock_ops = {
 	.ioctl          = sock_no_ioctl,
 	.listen         = llcp_sock_listen,
 	.shutdown       = sock_no_shutdown,
-	.setsockopt     = sock_no_setsockopt,
-	.getsockopt     = sock_no_getsockopt,
+	.setsockopt     = nfc_llcp_setsockopt,
+	.getsockopt     = nfc_llcp_getsockopt,
 	.sendmsg        = llcp_sock_sendmsg,
 	.recvmsg        = llcp_sock_recvmsg,
 	.mmap           = sock_no_mmap,