From 26fd76cab2e61cedc5c25f7151fb31b57ddc53c7 Mon Sep 17 00:00:00 2001
From: Samuel Ortiz <sameo@linux.intel.com>
Date: Fri, 22 Feb 2013 10:53:25 +0100
Subject: 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>

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 2b9f74b..428c37a 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -298,6 +298,7 @@ struct ucred {
 #define SOL_IUCV	277
 #define SOL_CAIF	278
 #define SOL_ALG		279
+#define SOL_NFC		280
 
 /* IPX options */
 #define IPX_TYPE	1
diff --git a/include/uapi/linux/nfc.h b/include/uapi/linux/nfc.h
index 7969f46..855630f 100644
--- a/include/uapi/linux/nfc.h
+++ b/include/uapi/linux/nfc.h
@@ -220,4 +220,8 @@ struct sockaddr_nfc_llcp {
 #define NFC_LLCP_DIRECTION_RX		0x00
 #define NFC_LLCP_DIRECTION_TX		0x01
 
+/* socket option names */
+#define NFC_LLCP_RW   0
+#define NFC_LLCP_MIUX 1
+
 #endif /*__LINUX_NFC_H */
diff --git a/net/nfc/llcp/llcp.h b/net/nfc/llcp/llcp.h
index 32cec81..5f117ad 100644
--- a/net/nfc/llcp/llcp.h
+++ b/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;
diff --git a/net/nfc/llcp/sock.c b/net/nfc/llcp/sock.c
index cc56499..9357a75 100644
--- a/net/nfc/llcp/sock.c
+++ b/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,
-- 
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