NFC: Extend netlink interface for LTO, RW, and MIUX parameters support

NFC_CMD_LLC_GET_PARAMS: request LTO, RW, and MIUX parameters for a device

NFC_CMD_LLC_SET_PARAMS: set one or more of LTO, RW, and MIUX parameters for
a device. LTO must be set before the link is up otherwise -EINPROGRESS is
returned. RW and MIUX can be set at anytime and will be passed in subsequent
CONNECT and CC messages. If one of the passed parameters is wrong none is
set and -EINVAL is returned.

Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 152 insertions, 0 deletions

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 614cfd0..3568ae1 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -29,6 +29,8 @@
 
 #include "nfc.h"
 
+#include "llcp/llcp.h"
+
 static struct genl_multicast_group nfc_genl_event_mcgrp = {
 	.name = NFC_GENL_MCAST_EVENT_NAME,
 };
@@ -716,6 +718,146 @@ static int nfc_genl_dep_link_down(struct sk_buff *skb, struct genl_info *info)
 	return rc;
 }
 
+static int nfc_genl_send_params(struct sk_buff *msg,
+				struct nfc_llcp_local *local,
+				u32 portid, u32 seq)
+{
+	void *hdr;
+
+	hdr = genlmsg_put(msg, portid, seq, &nfc_genl_family, 0,
+			  NFC_CMD_LLC_GET_PARAMS);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, local->dev->idx) ||
+	    nla_put_u8(msg, NFC_ATTR_LLC_PARAM_LTO, local->lto) ||
+	    nla_put_u8(msg, NFC_ATTR_LLC_PARAM_RW, local->rw) ||
+	    nla_put_u16(msg, NFC_ATTR_LLC_PARAM_MIUX, be16_to_cpu(local->miux)))
+		goto nla_put_failure;
+
+	return genlmsg_end(msg, hdr);
+
+nla_put_failure:
+
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+static int nfc_genl_llc_get_params(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfc_dev *dev;
+	struct nfc_llcp_local *local;
+	int rc = 0;
+	struct sk_buff *msg = NULL;
+	u32 idx;
+
+	if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
+		return -EINVAL;
+
+	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
+
+	dev = nfc_get_device(idx);
+	if (!dev)
+		return -ENODEV;
+
+	device_lock(&dev->dev);
+
+	local = nfc_llcp_find_local(dev);
+	if (!local) {
+		rc = -ENODEV;
+		goto exit;
+	}
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg) {
+		rc = -ENOMEM;
+		goto exit;
+	}
+
+	rc = nfc_genl_send_params(msg, local, info->snd_portid, info->snd_seq);
+
+exit:
+	device_unlock(&dev->dev);
+
+	nfc_put_device(dev);
+
+	if (rc < 0) {
+		if (msg)
+			nlmsg_free(msg);
+
+		return rc;
+	}
+
+	return genlmsg_reply(msg, info);
+}
+
+static int nfc_genl_llc_set_params(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfc_dev *dev;
+	struct nfc_llcp_local *local;
+	u8 rw = 0;
+	u16 miux = 0;
+	u32 idx;
+	int rc = 0;
+
+	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
+	    (!info->attrs[NFC_ATTR_LLC_PARAM_LTO] &&
+	     !info->attrs[NFC_ATTR_LLC_PARAM_RW] &&
+	     !info->attrs[NFC_ATTR_LLC_PARAM_MIUX]))
+		return -EINVAL;
+
+	if (info->attrs[NFC_ATTR_LLC_PARAM_RW]) {
+		rw = nla_get_u8(info->attrs[NFC_ATTR_LLC_PARAM_RW]);
+
+		if (rw > LLCP_MAX_RW)
+			return -EINVAL;
+	}
+
+	if (info->attrs[NFC_ATTR_LLC_PARAM_MIUX]) {
+		miux = nla_get_u16(info->attrs[NFC_ATTR_LLC_PARAM_MIUX]);
+
+		if (miux > LLCP_MAX_MIUX)
+			return -EINVAL;
+	}
+
+	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
+
+	dev = nfc_get_device(idx);
+	if (!dev)
+		return -ENODEV;
+
+	device_lock(&dev->dev);
+
+	local = nfc_llcp_find_local(dev);
+	if (!local) {
+		nfc_put_device(dev);
+		rc = -ENODEV;
+		goto exit;
+	}
+
+	if (info->attrs[NFC_ATTR_LLC_PARAM_LTO]) {
+		if (dev->dep_link_up) {
+			rc = -EINPROGRESS;
+			goto exit;
+		}
+
+		local->lto = nla_get_u8(info->attrs[NFC_ATTR_LLC_PARAM_LTO]);
+	}
+
+	if (info->attrs[NFC_ATTR_LLC_PARAM_RW])
+		local->rw = rw;
+
+	if (info->attrs[NFC_ATTR_LLC_PARAM_MIUX])
+		local->miux = cpu_to_be16(miux);
+
+exit:
+	device_unlock(&dev->dev);
+
+	nfc_put_device(dev);
+
+	return rc;
+}
+
 static struct genl_ops nfc_genl_ops[] = {
 	{
 		.cmd = NFC_CMD_GET_DEVICE,
@@ -760,6 +902,16 @@ static struct genl_ops nfc_genl_ops[] = {
 		.done = nfc_genl_dump_targets_done,
 		.policy = nfc_genl_policy,
 	},
+	{
+		.cmd = NFC_CMD_LLC_GET_PARAMS,
+		.doit = nfc_genl_llc_get_params,
+		.policy = nfc_genl_policy,
+	},
+	{
+		.cmd = NFC_CMD_LLC_SET_PARAMS,
+		.doit = nfc_genl_llc_set_params,
+		.policy = nfc_genl_policy,
+	},
 };