/*
   * 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 },

  };
  
  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);
  
  	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);

  	if (target->nfcid1_len > 0)
  		NLA_PUT(msg, NFC_ATTR_TARGET_NFCID1, target->nfcid1_len,
  				target->nfcid1);

  
  	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;
  
  	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
  
  	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_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;
  
  	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);
  
  	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;
  
  	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
  
  	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);
  
  	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);
  
  	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
  ");
  
  	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;
  
  	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
  	if (rf_mode == NFC_RF_INITIATOR)
  		NLA_PUT_U32(msg, NFC_ATTR_TARGET_INDEX, target_idx);
  	NLA_PUT_U8(msg, NFC_ATTR_COMM_MODE, comm_mode);
  	NLA_PUT_U8(msg, NFC_ATTR_RF_MODE, rf_mode);
  
  	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
  ");
  
  	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;
  
  	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
  
  	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
  ");

  	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, rf;
  
  	pr_debug("DEP link up
  ");
  
  	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
  			!info->attrs[NFC_ATTR_COMM_MODE] ||
  			!info->attrs[NFC_ATTR_RF_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]);
  	rf = nla_get_u8(info->attrs[NFC_ATTR_RF_MODE]);
  
  	if (comm != NFC_COMM_ACTIVE && comm != NFC_COMM_PASSIVE)
  		return -EINVAL;
  
  	if (rf != NFC_RF_INITIATOR && comm != NFC_RF_TARGET)
  		return -EINVAL;
  
  	dev = nfc_get_device(idx);
  	if (!dev)
  		return -ENODEV;
  
  	rc = nfc_dep_link_up(dev, tgt_idx, comm, rf);
  
  	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->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);
  }