net/nfc/netlink.c - kernel/msm-5.4 - Gitiles

 /*
  * Copyright (C) 2011 Instituto Nokia de Tecnologia
  *
  * Authors:
  *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
  *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the
  * Free Software Foundation, Inc.,
  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__

 #include <net/genetlink.h>
 #include <linux/nfc.h>
 #include <linux/slab.h>

 #include "nfc.h"

 static struct genl_multicast_group nfc_genl_event_mcgrp = {
 	.name = NFC_GENL_MCAST_EVENT_NAME,
 };

 struct genl_family nfc_genl_family = {
 	.id = GENL_ID_GENERATE,
 	.hdrsize = 0,
 	.name = NFC_GENL_NAME,
 	.version = NFC_GENL_VERSION,
 	.maxattr = NFC_ATTR_MAX,
 };

 static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {
 	[NFC_ATTR_DEVICE_INDEX] = { .type = NLA_U32 },
 	[NFC_ATTR_DEVICE_NAME] = { .type = NLA_STRING,
 				.len = NFC_DEVICE_NAME_MAXSIZE },
 	[NFC_ATTR_PROTOCOLS] = { .type = NLA_U32 },
 	[NFC_ATTR_COMM_MODE] = { .type = NLA_U8 },
 	[NFC_ATTR_RF_MODE] = { .type = NLA_U8 },
 	[NFC_ATTR_DEVICE_POWERED] = { .type = NLA_U8 },
 };

 static int nfc_genl_send_target(struct sk_buff *msg, struct nfc_target *target,
 				struct netlink_callback *cb, int flags)
 {
 	void *hdr;

 	hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
 			  &nfc_genl_family, flags, NFC_CMD_GET_TARGET);
 	if (!hdr)
 		return -EMSGSIZE;

 	genl_dump_check_consistent(cb, hdr, &nfc_genl_family);

 	if (nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target->idx) ||
 	    nla_put_u32(msg, NFC_ATTR_PROTOCOLS, target->supported_protocols) ||
 	    nla_put_u16(msg, NFC_ATTR_TARGET_SENS_RES, target->sens_res) ||
 	    nla_put_u8(msg, NFC_ATTR_TARGET_SEL_RES, target->sel_res))
 		goto nla_put_failure;
 	if (target->nfcid1_len > 0 &&
 	    nla_put(msg, NFC_ATTR_TARGET_NFCID1, target->nfcid1_len,
 		    target->nfcid1))
 		goto nla_put_failure;
 	if (target->sensb_res_len > 0 &&
 	    nla_put(msg, NFC_ATTR_TARGET_SENSB_RES, target->sensb_res_len,
 		    target->sensb_res))
 		goto nla_put_failure;
 	if (target->sensf_res_len > 0 &&
 	    nla_put(msg, NFC_ATTR_TARGET_SENSF_RES, target->sensf_res_len,
 		    target->sensf_res))
 		goto nla_put_failure;

 	return genlmsg_end(msg, hdr);

 nla_put_failure:
 	genlmsg_cancel(msg, hdr);
 	return -EMSGSIZE;
 }

 static struct nfc_dev *__get_device_from_cb(struct netlink_callback *cb)
 {
 	struct nfc_dev *dev;
 	int rc;
 	u32 idx;

 	rc = nlmsg_parse(cb->nlh, GENL_HDRLEN + nfc_genl_family.hdrsize,
 			 nfc_genl_family.attrbuf,
 			 nfc_genl_family.maxattr,
 			 nfc_genl_policy);
 	if (rc < 0)
 		return ERR_PTR(rc);

 	if (!nfc_genl_family.attrbuf[NFC_ATTR_DEVICE_INDEX])
 		return ERR_PTR(-EINVAL);

 	idx = nla_get_u32(nfc_genl_family.attrbuf[NFC_ATTR_DEVICE_INDEX]);

 	dev = nfc_get_device(idx);
 	if (!dev)
 		return ERR_PTR(-ENODEV);

 	return dev;
 }

 static int nfc_genl_dump_targets(struct sk_buff *skb,
 				 struct netlink_callback *cb)
 {
 	int i = cb->args[0];
 	struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
 	int rc;

 	if (!dev) {
 		dev = __get_device_from_cb(cb);
 		if (IS_ERR(dev))
 			return PTR_ERR(dev);

 		cb->args[1] = (long) dev;
 	}

 	spin_lock_bh(&dev->targets_lock);

 	cb->seq = dev->targets_generation;

 	while (i < dev->n_targets) {
 		rc = nfc_genl_send_target(skb, &dev->targets[i], cb,
 					  NLM_F_MULTI);
 		if (rc < 0)
 			break;

 		i++;
 	}

 	spin_unlock_bh(&dev->targets_lock);

 	cb->args[0] = i;

 	return skb->len;
 }

 static int nfc_genl_dump_targets_done(struct netlink_callback *cb)
 {
 	struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];

 	if (dev)
 		nfc_put_device(dev);

 	return 0;
 }

 int nfc_genl_targets_found(struct nfc_dev *dev)
 {
 	struct sk_buff *msg;
 	void *hdr;

 	dev->genl_data.poll_req_pid = 0;

 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
 	if (!msg)
 		return -ENOMEM;

 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
 			  NFC_EVENT_TARGETS_FOUND);
 	if (!hdr)
 		goto free_msg;

 	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
 		goto nla_put_failure;

 	genlmsg_end(msg, hdr);

 	return genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);

 nla_put_failure:
 	genlmsg_cancel(msg, hdr);
 free_msg:
 	nlmsg_free(msg);
 	return -EMSGSIZE;
 }

 int nfc_genl_target_lost(struct nfc_dev *dev, u32 target_idx)
 {
 	struct sk_buff *msg;
 	void *hdr;

 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
 			  NFC_EVENT_TARGET_LOST);
 	if (!hdr)
 		goto free_msg;

 	if (nla_put_string(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev)) ||
 	    nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target_idx))
 		goto nla_put_failure;

 	genlmsg_end(msg, hdr);

 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);

 	return 0;

 nla_put_failure:
 	genlmsg_cancel(msg, hdr);
 free_msg:
 	nlmsg_free(msg);
 	return -EMSGSIZE;
 }

 int nfc_genl_device_added(struct nfc_dev *dev)
 {
 	struct sk_buff *msg;
 	void *hdr;

 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
 			  NFC_EVENT_DEVICE_ADDED);
 	if (!hdr)
 		goto free_msg;

 	if (nla_put_string(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev)) ||
 	    nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
 	    nla_put_u32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols) ||
 	    nla_put_u8(msg, NFC_ATTR_DEVICE_POWERED, dev->dev_up))
 		goto nla_put_failure;

 	genlmsg_end(msg, hdr);

 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);

 	return 0;

 nla_put_failure:
 	genlmsg_cancel(msg, hdr);
 free_msg:
 	nlmsg_free(msg);
 	return -EMSGSIZE;
 }

 int nfc_genl_device_removed(struct nfc_dev *dev)
 {
 	struct sk_buff *msg;
 	void *hdr;

 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
 			  NFC_EVENT_DEVICE_REMOVED);
 	if (!hdr)
 		goto free_msg;

 	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
 		goto nla_put_failure;

 	genlmsg_end(msg, hdr);

 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);

 	return 0;

 nla_put_failure:
 	genlmsg_cancel(msg, hdr);
 free_msg:
 	nlmsg_free(msg);
 	return -EMSGSIZE;
 }

 static int nfc_genl_send_device(struct sk_buff *msg, struct nfc_dev *dev,
 				u32 pid, u32 seq,
 				struct netlink_callback *cb,
 				int flags)
 {
 	void *hdr;

 	hdr = genlmsg_put(msg, pid, seq, &nfc_genl_family, flags,
 			  NFC_CMD_GET_DEVICE);
 	if (!hdr)
 		return -EMSGSIZE;

 	if (cb)
 		genl_dump_check_consistent(cb, hdr, &nfc_genl_family);

 	if (nla_put_string(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev)) ||
 	    nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
 	    nla_put_u32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols) ||
 	    nla_put_u8(msg, NFC_ATTR_DEVICE_POWERED, dev->dev_up))
 		goto nla_put_failure;

 	return genlmsg_end(msg, hdr);

 nla_put_failure:
 	genlmsg_cancel(msg, hdr);
 	return -EMSGSIZE;
 }

 static int nfc_genl_dump_devices(struct sk_buff *skb,
 				 struct netlink_callback *cb)
 {
 	struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
 	struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
 	bool first_call = false;

 	if (!iter) {
 		first_call = true;
 		iter = kmalloc(sizeof(struct class_dev_iter), GFP_KERNEL);
 		if (!iter)
 			return -ENOMEM;
 		cb->args[0] = (long) iter;
 	}

 	mutex_lock(&nfc_devlist_mutex);

 	cb->seq = nfc_devlist_generation;

 	if (first_call) {
 		nfc_device_iter_init(iter);
 		dev = nfc_device_iter_next(iter);
 	}

 	while (dev) {
 		int rc;

 		rc = nfc_genl_send_device(skb, dev, NETLINK_CB(cb->skb).pid,
 					  cb->nlh->nlmsg_seq, cb, NLM_F_MULTI);
 		if (rc < 0)
 			break;

 		dev = nfc_device_iter_next(iter);
 	}

 	mutex_unlock(&nfc_devlist_mutex);

 	cb->args[1] = (long) dev;

 	return skb->len;
 }

 static int nfc_genl_dump_devices_done(struct netlink_callback *cb)
 {
 	struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];

 	nfc_device_iter_exit(iter);
 	kfree(iter);

 	return 0;
 }

 int nfc_genl_dep_link_up_event(struct nfc_dev *dev, u32 target_idx,
 			       u8 comm_mode, u8 rf_mode)
 {
 	struct sk_buff *msg;
 	void *hdr;

 	pr_debug("DEP link is up\n");

 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
 	if (!msg)
 		return -ENOMEM;

 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0, NFC_CMD_DEP_LINK_UP);
 	if (!hdr)
 		goto free_msg;

 	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
 		goto nla_put_failure;
 	if (rf_mode == NFC_RF_INITIATOR &&
 	    nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target_idx))
 		goto nla_put_failure;
 	if (nla_put_u8(msg, NFC_ATTR_COMM_MODE, comm_mode) ||
 	    nla_put_u8(msg, NFC_ATTR_RF_MODE, rf_mode))
 		goto nla_put_failure;

 	genlmsg_end(msg, hdr);

 	dev->dep_link_up = true;

 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);

 	return 0;

 nla_put_failure:
 	genlmsg_cancel(msg, hdr);
 free_msg:
 	nlmsg_free(msg);
 	return -EMSGSIZE;
 }

 int nfc_genl_dep_link_down_event(struct nfc_dev *dev)
 {
 	struct sk_buff *msg;
 	void *hdr;

 	pr_debug("DEP link is down\n");

 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
 	if (!msg)
 		return -ENOMEM;

 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
 			  NFC_CMD_DEP_LINK_DOWN);
 	if (!hdr)
 		goto free_msg;

 	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
 		goto nla_put_failure;

 	genlmsg_end(msg, hdr);

 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);

 	return 0;

 nla_put_failure:
 	genlmsg_cancel(msg, hdr);
 free_msg:
 	nlmsg_free(msg);
 	return -EMSGSIZE;
 }

 static int nfc_genl_get_device(struct sk_buff *skb, struct genl_info *info)
 {
 	struct sk_buff *msg;
 	struct nfc_dev *dev;
 	u32 idx;
 	int rc = -ENOBUFS;

 	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;

 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!msg) {
 		rc = -ENOMEM;
 		goto out_putdev;
 	}

 	rc = nfc_genl_send_device(msg, dev, info->snd_pid, info->snd_seq,
 				  NULL, 0);
 	if (rc < 0)
 		goto out_free;

 	nfc_put_device(dev);

 	return genlmsg_reply(msg, info);

 out_free:
 	nlmsg_free(msg);
 out_putdev:
 	nfc_put_device(dev);
 	return rc;
 }

 static int nfc_genl_dev_up(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nfc_dev *dev;
 	int rc;
 	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;

 	rc = nfc_dev_up(dev);

 	nfc_put_device(dev);
 	return rc;
 }

 static int nfc_genl_dev_down(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nfc_dev *dev;
 	int rc;
 	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;

 	rc = nfc_dev_down(dev);

 	nfc_put_device(dev);
 	return rc;
 }

 static int nfc_genl_start_poll(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nfc_dev *dev;
 	int rc;
 	u32 idx;
 	u32 protocols;

 	pr_debug("Poll start\n");

 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
 	    !info->attrs[NFC_ATTR_PROTOCOLS])
 		return -EINVAL;

 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
 	protocols = nla_get_u32(info->attrs[NFC_ATTR_PROTOCOLS]);

 	dev = nfc_get_device(idx);
 	if (!dev)
 		return -ENODEV;

 	mutex_lock(&dev->genl_data.genl_data_mutex);

 	rc = nfc_start_poll(dev, protocols);
 	if (!rc)
 		dev->genl_data.poll_req_pid = info->snd_pid;

 	mutex_unlock(&dev->genl_data.genl_data_mutex);

 	nfc_put_device(dev);
 	return rc;
 }

 static int nfc_genl_stop_poll(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nfc_dev *dev;
 	int rc;
 	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;

 	mutex_lock(&dev->genl_data.genl_data_mutex);

 	if (dev->genl_data.poll_req_pid != info->snd_pid) {
 		rc = -EBUSY;
 		goto out;
 	}

 	rc = nfc_stop_poll(dev);
 	dev->genl_data.poll_req_pid = 0;

 out:
 	mutex_unlock(&dev->genl_data.genl_data_mutex);
 	nfc_put_device(dev);
 	return rc;
 }

 static int nfc_genl_dep_link_up(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nfc_dev *dev;
 	int rc, tgt_idx;
 	u32 idx;
 	u8 comm;

 	pr_debug("DEP link up\n");

 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
 	    !info->attrs[NFC_ATTR_COMM_MODE])
 		return -EINVAL;

 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
 	if (!info->attrs[NFC_ATTR_TARGET_INDEX])
 		tgt_idx = NFC_TARGET_IDX_ANY;
 	else
 		tgt_idx = nla_get_u32(info->attrs[NFC_ATTR_TARGET_INDEX]);

 	comm = nla_get_u8(info->attrs[NFC_ATTR_COMM_MODE]);

 	if (comm != NFC_COMM_ACTIVE && comm != NFC_COMM_PASSIVE)
 		return -EINVAL;

 	dev = nfc_get_device(idx);
 	if (!dev)
 		return -ENODEV;

 	rc = nfc_dep_link_up(dev, tgt_idx, comm);

 	nfc_put_device(dev);

 	return rc;
 }

 static int nfc_genl_dep_link_down(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nfc_dev *dev;
 	int rc;
 	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;

 	rc = nfc_dep_link_down(dev);

 	nfc_put_device(dev);
 	return rc;
 }

 static struct genl_ops nfc_genl_ops[] = {
 	{
 		.cmd = NFC_CMD_GET_DEVICE,
 		.doit = nfc_genl_get_device,
 		.dumpit = nfc_genl_dump_devices,
 		.done = nfc_genl_dump_devices_done,
 		.policy = nfc_genl_policy,
 	},
 	{
 		.cmd = NFC_CMD_DEV_UP,
 		.doit = nfc_genl_dev_up,
 		.policy = nfc_genl_policy,
 	},
 	{
 		.cmd = NFC_CMD_DEV_DOWN,
 		.doit = nfc_genl_dev_down,
 		.policy = nfc_genl_policy,
 	},
 	{
 		.cmd = NFC_CMD_START_POLL,
 		.doit = nfc_genl_start_poll,
 		.policy = nfc_genl_policy,
 	},
 	{
 		.cmd = NFC_CMD_STOP_POLL,
 		.doit = nfc_genl_stop_poll,
 		.policy = nfc_genl_policy,
 	},
 	{
 		.cmd = NFC_CMD_DEP_LINK_UP,
 		.doit = nfc_genl_dep_link_up,
 		.policy = nfc_genl_policy,
 	},
 	{
 		.cmd = NFC_CMD_DEP_LINK_DOWN,
 		.doit = nfc_genl_dep_link_down,
 		.policy = nfc_genl_policy,
 	},
 	{
 		.cmd = NFC_CMD_GET_TARGET,
 		.dumpit = nfc_genl_dump_targets,
 		.done = nfc_genl_dump_targets_done,
 		.policy = nfc_genl_policy,
 	},
 };

 static int nfc_genl_rcv_nl_event(struct notifier_block *this,
 				 unsigned long event, void *ptr)
 {
 	struct netlink_notify *n = ptr;
 	struct class_dev_iter iter;
 	struct nfc_dev *dev;

 	if (event != NETLINK_URELEASE || n->protocol != NETLINK_GENERIC)
 		goto out;

 	pr_debug("NETLINK_URELEASE event from id %d\n", n->pid);

 	nfc_device_iter_init(&iter);
 	dev = nfc_device_iter_next(&iter);

 	while (dev) {
 		if (dev->genl_data.poll_req_pid == n->pid) {
 			nfc_stop_poll(dev);
 			dev->genl_data.poll_req_pid = 0;
 		}
 		dev = nfc_device_iter_next(&iter);
 	}

 	nfc_device_iter_exit(&iter);

 out:
 	return NOTIFY_DONE;
 }

 void nfc_genl_data_init(struct nfc_genl_data *genl_data)
 {
 	genl_data->poll_req_pid = 0;
 	mutex_init(&genl_data->genl_data_mutex);
 }

 void nfc_genl_data_exit(struct nfc_genl_data *genl_data)
 {
 	mutex_destroy(&genl_data->genl_data_mutex);
 }

 static struct notifier_block nl_notifier = {
 	.notifier_call  = nfc_genl_rcv_nl_event,
 };

 /**
  * nfc_genl_init() - Initialize netlink interface
  *
  * This initialization function registers the nfc netlink family.
  */
 int __init nfc_genl_init(void)
 {
 	int rc;

 	rc = genl_register_family_with_ops(&nfc_genl_family, nfc_genl_ops,
 					   ARRAY_SIZE(nfc_genl_ops));
 	if (rc)
 		return rc;

 	rc = genl_register_mc_group(&nfc_genl_family, &nfc_genl_event_mcgrp);

 	netlink_register_notifier(&nl_notifier);

 	return rc;
 }

 /**
  * nfc_genl_exit() - Deinitialize netlink interface
  *
  * This exit function unregisters the nfc netlink family.
  */
 void nfc_genl_exit(void)
 {
 	netlink_unregister_notifier(&nl_notifier);
 	genl_unregister_family(&nfc_genl_family);
 }
	/*
	* Copyright (C) 2011 Instituto Nokia de Tecnologia
	*
	* Authors:
	* Lauro Ramos Venancio <lauro.venancio@openbossa.org>
	* Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the
	* Free Software Foundation, Inc.,
	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__

	#include <net/genetlink.h>
	#include <linux/nfc.h>
	#include <linux/slab.h>

	#include "nfc.h"

	static struct genl_multicast_group nfc_genl_event_mcgrp = {
	.name = NFC_GENL_MCAST_EVENT_NAME,
	};

	struct genl_family nfc_genl_family = {
	.id = GENL_ID_GENERATE,
	.hdrsize = 0,
	.name = NFC_GENL_NAME,
	.version = NFC_GENL_VERSION,
	.maxattr = NFC_ATTR_MAX,
	};

	static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {
	[NFC_ATTR_DEVICE_INDEX] = { .type = NLA_U32 },
	[NFC_ATTR_DEVICE_NAME] = { .type = NLA_STRING,
	.len = NFC_DEVICE_NAME_MAXSIZE },
	[NFC_ATTR_PROTOCOLS] = { .type = NLA_U32 },
	[NFC_ATTR_COMM_MODE] = { .type = NLA_U8 },
	[NFC_ATTR_RF_MODE] = { .type = NLA_U8 },
	[NFC_ATTR_DEVICE_POWERED] = { .type = NLA_U8 },
	};

	static int nfc_genl_send_target(struct sk_buff msg, struct nfc_target target,
	struct netlink_callback *cb, int flags)
	{
	void *hdr;

	hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
	&nfc_genl_family, flags, NFC_CMD_GET_TARGET);
	if (!hdr)
	return -EMSGSIZE;

	genl_dump_check_consistent(cb, hdr, &nfc_genl_family);

	if (nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target->idx) \|\|
	nla_put_u32(msg, NFC_ATTR_PROTOCOLS, target->supported_protocols) \|\|
	nla_put_u16(msg, NFC_ATTR_TARGET_SENS_RES, target->sens_res) \|\|
	nla_put_u8(msg, NFC_ATTR_TARGET_SEL_RES, target->sel_res))
	goto nla_put_failure;
	if (target->nfcid1_len > 0 &&
	nla_put(msg, NFC_ATTR_TARGET_NFCID1, target->nfcid1_len,
	target->nfcid1))
	goto nla_put_failure;
	if (target->sensb_res_len > 0 &&
	nla_put(msg, NFC_ATTR_TARGET_SENSB_RES, target->sensb_res_len,
	target->sensb_res))
	goto nla_put_failure;
	if (target->sensf_res_len > 0 &&
	nla_put(msg, NFC_ATTR_TARGET_SENSF_RES, target->sensf_res_len,
	target->sensf_res))
	goto nla_put_failure;

	return genlmsg_end(msg, hdr);

	nla_put_failure:
	genlmsg_cancel(msg, hdr);
	return -EMSGSIZE;
	}

	static struct nfc_dev __get_device_from_cb(struct netlink_callback cb)
	{
	struct nfc_dev *dev;
	int rc;
	u32 idx;

	rc = nlmsg_parse(cb->nlh, GENL_HDRLEN + nfc_genl_family.hdrsize,
	nfc_genl_family.attrbuf,
	nfc_genl_family.maxattr,
	nfc_genl_policy);
	if (rc < 0)
	return ERR_PTR(rc);

	if (!nfc_genl_family.attrbuf[NFC_ATTR_DEVICE_INDEX])
	return ERR_PTR(-EINVAL);

	idx = nla_get_u32(nfc_genl_family.attrbuf[NFC_ATTR_DEVICE_INDEX]);

	dev = nfc_get_device(idx);
	if (!dev)
	return ERR_PTR(-ENODEV);

	return dev;
	}

	static int nfc_genl_dump_targets(struct sk_buff *skb,
	struct netlink_callback *cb)
	{
	int i = cb->args[0];
	struct nfc_dev dev = (struct nfc_dev ) cb->args[1];
	int rc;

	if (!dev) {
	dev = __get_device_from_cb(cb);
	if (IS_ERR(dev))
	return PTR_ERR(dev);

	cb->args[1] = (long) dev;
	}

	spin_lock_bh(&dev->targets_lock);

	cb->seq = dev->targets_generation;

	while (i < dev->n_targets) {
	rc = nfc_genl_send_target(skb, &dev->targets[i], cb,
	NLM_F_MULTI);
	if (rc < 0)
	break;

	i++;
	}

	spin_unlock_bh(&dev->targets_lock);

	cb->args[0] = i;

	return skb->len;
	}

	static int nfc_genl_dump_targets_done(struct netlink_callback *cb)
	{
	struct nfc_dev dev = (struct nfc_dev ) cb->args[1];

	if (dev)
	nfc_put_device(dev);

	return 0;
	}

	int nfc_genl_targets_found(struct nfc_dev *dev)
	{
	struct sk_buff *msg;
	void *hdr;

	dev->genl_data.poll_req_pid = 0;

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
	if (!msg)
	return -ENOMEM;

	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
	NFC_EVENT_TARGETS_FOUND);
	if (!hdr)
	goto free_msg;

	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
	goto nla_put_failure;

	genlmsg_end(msg, hdr);

	return genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);

	nla_put_failure:
	genlmsg_cancel(msg, hdr);
	free_msg:
	nlmsg_free(msg);
	return -EMSGSIZE;
	}

	int nfc_genl_target_lost(struct nfc_dev *dev, u32 target_idx)
	{
	struct sk_buff *msg;
	void *hdr;

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
	NFC_EVENT_TARGET_LOST);
	if (!hdr)
	goto free_msg;

	if (nla_put_string(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev)) \|\|
	nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target_idx))
	goto nla_put_failure;

	genlmsg_end(msg, hdr);

	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);

	return 0;

	nla_put_failure:
	genlmsg_cancel(msg, hdr);
	free_msg:
	nlmsg_free(msg);
	return -EMSGSIZE;
	}

	int nfc_genl_device_added(struct nfc_dev *dev)
	{
	struct sk_buff *msg;
	void *hdr;

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
	NFC_EVENT_DEVICE_ADDED);
	if (!hdr)
	goto free_msg;

	if (nla_put_string(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev)) \|\|
	nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) \|\|
	nla_put_u32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols) \|\|
	nla_put_u8(msg, NFC_ATTR_DEVICE_POWERED, dev->dev_up))
	goto nla_put_failure;

	genlmsg_end(msg, hdr);

	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);

	return 0;

	nla_put_failure:
	genlmsg_cancel(msg, hdr);
	free_msg:
	nlmsg_free(msg);
	return -EMSGSIZE;
	}

	int nfc_genl_device_removed(struct nfc_dev *dev)
	{
	struct sk_buff *msg;
	void *hdr;

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
	NFC_EVENT_DEVICE_REMOVED);
	if (!hdr)
	goto free_msg;

	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
	goto nla_put_failure;

	genlmsg_end(msg, hdr);

	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);

	return 0;

	nla_put_failure:
	genlmsg_cancel(msg, hdr);
	free_msg:
	nlmsg_free(msg);
	return -EMSGSIZE;
	}

	static int nfc_genl_send_device(struct sk_buff msg, struct nfc_dev dev,
	u32 pid, u32 seq,
	struct netlink_callback *cb,
	int flags)
	{
	void *hdr;

	hdr = genlmsg_put(msg, pid, seq, &nfc_genl_family, flags,
	NFC_CMD_GET_DEVICE);
	if (!hdr)
	return -EMSGSIZE;

	if (cb)
	genl_dump_check_consistent(cb, hdr, &nfc_genl_family);

	if (nla_put_string(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev)) \|\|
	nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) \|\|
	nla_put_u32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols) \|\|
	nla_put_u8(msg, NFC_ATTR_DEVICE_POWERED, dev->dev_up))
	goto nla_put_failure;

	return genlmsg_end(msg, hdr);

	nla_put_failure:
	genlmsg_cancel(msg, hdr);
	return -EMSGSIZE;
	}

	static int nfc_genl_dump_devices(struct sk_buff *skb,
	struct netlink_callback *cb)
	{
	struct class_dev_iter iter = (struct class_dev_iter ) cb->args[0];
	struct nfc_dev dev = (struct nfc_dev ) cb->args[1];
	bool first_call = false;

	if (!iter) {
	first_call = true;
	iter = kmalloc(sizeof(struct class_dev_iter), GFP_KERNEL);
	if (!iter)
	return -ENOMEM;
	cb->args[0] = (long) iter;
	}

	mutex_lock(&nfc_devlist_mutex);

	cb->seq = nfc_devlist_generation;

	if (first_call) {
	nfc_device_iter_init(iter);
	dev = nfc_device_iter_next(iter);
	}

	while (dev) {
	int rc;

	rc = nfc_genl_send_device(skb, dev, NETLINK_CB(cb->skb).pid,
	cb->nlh->nlmsg_seq, cb, NLM_F_MULTI);
	if (rc < 0)
	break;

	dev = nfc_device_iter_next(iter);
	}

	mutex_unlock(&nfc_devlist_mutex);

	cb->args[1] = (long) dev;

	return skb->len;
	}

	static int nfc_genl_dump_devices_done(struct netlink_callback *cb)
	{
	struct class_dev_iter iter = (struct class_dev_iter ) cb->args[0];

	nfc_device_iter_exit(iter);
	kfree(iter);

	return 0;
	}

	int nfc_genl_dep_link_up_event(struct nfc_dev *dev, u32 target_idx,
	u8 comm_mode, u8 rf_mode)
	{
	struct sk_buff *msg;
	void *hdr;

	pr_debug("DEP link is up\n");

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
	if (!msg)
	return -ENOMEM;

	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0, NFC_CMD_DEP_LINK_UP);
	if (!hdr)
	goto free_msg;

	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
	goto nla_put_failure;
	if (rf_mode == NFC_RF_INITIATOR &&
	nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target_idx))
	goto nla_put_failure;
	if (nla_put_u8(msg, NFC_ATTR_COMM_MODE, comm_mode) \|\|
	nla_put_u8(msg, NFC_ATTR_RF_MODE, rf_mode))
	goto nla_put_failure;

	genlmsg_end(msg, hdr);

	dev->dep_link_up = true;

	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);

	return 0;

	nla_put_failure:
	genlmsg_cancel(msg, hdr);
	free_msg:
	nlmsg_free(msg);
	return -EMSGSIZE;
	}

	int nfc_genl_dep_link_down_event(struct nfc_dev *dev)
	{
	struct sk_buff *msg;
	void *hdr;

	pr_debug("DEP link is down\n");

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
	if (!msg)
	return -ENOMEM;

	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
	NFC_CMD_DEP_LINK_DOWN);
	if (!hdr)
	goto free_msg;

	if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
	goto nla_put_failure;

	genlmsg_end(msg, hdr);

	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);

	return 0;

	nla_put_failure:
	genlmsg_cancel(msg, hdr);
	free_msg:
	nlmsg_free(msg);
	return -EMSGSIZE;
	}

	static int nfc_genl_get_device(struct sk_buff skb, struct genl_info info)
	{
	struct sk_buff *msg;
	struct nfc_dev *dev;
	u32 idx;
	int rc = -ENOBUFS;

	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;

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!msg) {
	rc = -ENOMEM;
	goto out_putdev;
	}

	rc = nfc_genl_send_device(msg, dev, info->snd_pid, info->snd_seq,
	NULL, 0);
	if (rc < 0)
	goto out_free;

	nfc_put_device(dev);

	return genlmsg_reply(msg, info);

	out_free:
	nlmsg_free(msg);
	out_putdev:
	nfc_put_device(dev);
	return rc;
	}

	static int nfc_genl_dev_up(struct sk_buff skb, struct genl_info info)
	{
	struct nfc_dev *dev;
	int rc;
	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;

	rc = nfc_dev_up(dev);

	nfc_put_device(dev);
	return rc;
	}

	static int nfc_genl_dev_down(struct sk_buff skb, struct genl_info info)
	{
	struct nfc_dev *dev;
	int rc;
	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;

	rc = nfc_dev_down(dev);

	nfc_put_device(dev);
	return rc;
	}

	static int nfc_genl_start_poll(struct sk_buff skb, struct genl_info info)
	{
	struct nfc_dev *dev;
	int rc;
	u32 idx;
	u32 protocols;

	pr_debug("Poll start\n");

	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] \|\|
	!info->attrs[NFC_ATTR_PROTOCOLS])
	return -EINVAL;

	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
	protocols = nla_get_u32(info->attrs[NFC_ATTR_PROTOCOLS]);

	dev = nfc_get_device(idx);
	if (!dev)
	return -ENODEV;

	mutex_lock(&dev->genl_data.genl_data_mutex);

	rc = nfc_start_poll(dev, protocols);
	if (!rc)
	dev->genl_data.poll_req_pid = info->snd_pid;

	mutex_unlock(&dev->genl_data.genl_data_mutex);

	nfc_put_device(dev);
	return rc;
	}

	static int nfc_genl_stop_poll(struct sk_buff skb, struct genl_info info)
	{
	struct nfc_dev *dev;
	int rc;
	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;

	mutex_lock(&dev->genl_data.genl_data_mutex);

	if (dev->genl_data.poll_req_pid != info->snd_pid) {
	rc = -EBUSY;
	goto out;
	}

	rc = nfc_stop_poll(dev);
	dev->genl_data.poll_req_pid = 0;

	out:
	mutex_unlock(&dev->genl_data.genl_data_mutex);
	nfc_put_device(dev);
	return rc;
	}

	static int nfc_genl_dep_link_up(struct sk_buff skb, struct genl_info info)
	{
	struct nfc_dev *dev;
	int rc, tgt_idx;
	u32 idx;
	u8 comm;

	pr_debug("DEP link up\n");

	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] \|\|
	!info->attrs[NFC_ATTR_COMM_MODE])
	return -EINVAL;

	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
	if (!info->attrs[NFC_ATTR_TARGET_INDEX])
	tgt_idx = NFC_TARGET_IDX_ANY;
	else
	tgt_idx = nla_get_u32(info->attrs[NFC_ATTR_TARGET_INDEX]);

	comm = nla_get_u8(info->attrs[NFC_ATTR_COMM_MODE]);

	if (comm != NFC_COMM_ACTIVE && comm != NFC_COMM_PASSIVE)
	return -EINVAL;

	dev = nfc_get_device(idx);
	if (!dev)
	return -ENODEV;

	rc = nfc_dep_link_up(dev, tgt_idx, comm);

	nfc_put_device(dev);

	return rc;
	}

	static int nfc_genl_dep_link_down(struct sk_buff skb, struct genl_info info)
	{
	struct nfc_dev *dev;
	int rc;
	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;

	rc = nfc_dep_link_down(dev);

	nfc_put_device(dev);
	return rc;
	}

	static struct genl_ops nfc_genl_ops[] = {
	{
	.cmd = NFC_CMD_GET_DEVICE,
	.doit = nfc_genl_get_device,
	.dumpit = nfc_genl_dump_devices,
	.done = nfc_genl_dump_devices_done,
	.policy = nfc_genl_policy,
	},
	{
	.cmd = NFC_CMD_DEV_UP,
	.doit = nfc_genl_dev_up,
	.policy = nfc_genl_policy,
	},
	{
	.cmd = NFC_CMD_DEV_DOWN,
	.doit = nfc_genl_dev_down,
	.policy = nfc_genl_policy,
	},
	{
	.cmd = NFC_CMD_START_POLL,
	.doit = nfc_genl_start_poll,
	.policy = nfc_genl_policy,
	},
	{
	.cmd = NFC_CMD_STOP_POLL,
	.doit = nfc_genl_stop_poll,
	.policy = nfc_genl_policy,
	},
	{
	.cmd = NFC_CMD_DEP_LINK_UP,
	.doit = nfc_genl_dep_link_up,
	.policy = nfc_genl_policy,
	},
	{
	.cmd = NFC_CMD_DEP_LINK_DOWN,
	.doit = nfc_genl_dep_link_down,
	.policy = nfc_genl_policy,
	},
	{
	.cmd = NFC_CMD_GET_TARGET,
	.dumpit = nfc_genl_dump_targets,
	.done = nfc_genl_dump_targets_done,
	.policy = nfc_genl_policy,
	},
	};

	static int nfc_genl_rcv_nl_event(struct notifier_block *this,
	unsigned long event, void *ptr)
	{
	struct netlink_notify *n = ptr;
	struct class_dev_iter iter;
	struct nfc_dev *dev;

	if (event != NETLINK_URELEASE \|\| n->protocol != NETLINK_GENERIC)
	goto out;

	pr_debug("NETLINK_URELEASE event from id %d\n", n->pid);

	nfc_device_iter_init(&iter);
	dev = nfc_device_iter_next(&iter);

	while (dev) {
	if (dev->genl_data.poll_req_pid == n->pid) {
	nfc_stop_poll(dev);
	dev->genl_data.poll_req_pid = 0;
	}
	dev = nfc_device_iter_next(&iter);
	}

	nfc_device_iter_exit(&iter);

	out:
	return NOTIFY_DONE;
	}

	void nfc_genl_data_init(struct nfc_genl_data *genl_data)
	{
	genl_data->poll_req_pid = 0;
	mutex_init(&genl_data->genl_data_mutex);
	}

	void nfc_genl_data_exit(struct nfc_genl_data *genl_data)
	{
	mutex_destroy(&genl_data->genl_data_mutex);
	}

	static struct notifier_block nl_notifier = {
	.notifier_call = nfc_genl_rcv_nl_event,
	};

	/**
	* nfc_genl_init() - Initialize netlink interface
	*
	* This initialization function registers the nfc netlink family.
	*/
	int __init nfc_genl_init(void)
	{
	int rc;

	rc = genl_register_family_with_ops(&nfc_genl_family, nfc_genl_ops,
	ARRAY_SIZE(nfc_genl_ops));
	if (rc)
	return rc;

	rc = genl_register_mc_group(&nfc_genl_family, &nfc_genl_event_mcgrp);

	netlink_register_notifier(&nl_notifier);

	return rc;
	}

	/**
	* nfc_genl_exit() - Deinitialize netlink interface
	*
	* This exit function unregisters the nfc netlink family.
	*/
	void nfc_genl_exit(void)
	{
	netlink_unregister_notifier(&nl_notifier);
	genl_unregister_family(&nfc_genl_family);
	}