text: /*
   * Copyright (c) 2014 Chelsio, Inc. All rights reserved.
   * Copyright (c) 2014 Intel Corporation. All rights reserved.
   *
   * This software is available to you under a choice of one of two
   * licenses.  You may choose to be licensed under the terms of the GNU
   * General Public License (GPL) Version 2, available from the file
   * COPYING in the main directory of this source tree, or the
   * OpenIB.org BSD license below:
   *
   *     Redistribution and use in source and binary forms, with or
   *     without modification, are permitted provided that the following
   *     conditions are met:
   *
   *      - Redistributions of source code must retain the above
   *	  copyright notice, this list of conditions and the following
   *	  disclaimer.
   *
   *      - Redistributions in binary form must reproduce the above
   *	  copyright notice, this list of conditions and the following
   *	  disclaimer in the documentation and/or other materials
   *	  provided with the distribution.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include "iwpm_util.h"
  
  #define IWPM_MAPINFO_HASH_SIZE	512
  #define IWPM_MAPINFO_HASH_MASK	(IWPM_MAPINFO_HASH_SIZE - 1)
  #define IWPM_REMINFO_HASH_SIZE	64
  #define IWPM_REMINFO_HASH_MASK	(IWPM_REMINFO_HASH_SIZE - 1)
  #define IWPM_MSG_SIZE		512
  
  static LIST_HEAD(iwpm_nlmsg_req_list);
  static DEFINE_SPINLOCK(iwpm_nlmsg_req_lock);
  
  static struct hlist_head *iwpm_hash_bucket;
  static DEFINE_SPINLOCK(iwpm_mapinfo_lock);
  
  static struct hlist_head *iwpm_reminfo_bucket;
  static DEFINE_SPINLOCK(iwpm_reminfo_lock);
  
  static DEFINE_MUTEX(iwpm_admin_lock);
  static struct iwpm_admin_data iwpm_admin;
  
  int iwpm_init(u8 nl_client)
  {
  	int ret = 0;
  	mutex_lock(&iwpm_admin_lock);
  	if (atomic_read(&iwpm_admin.refcount) == 0) {
  		iwpm_hash_bucket = kcalloc(IWPM_MAPINFO_HASH_SIZE,
  					   sizeof(struct hlist_head),
  					   GFP_KERNEL);
  		if (!iwpm_hash_bucket) {
  			ret = -ENOMEM;
  			goto init_exit;
  		}
  		iwpm_reminfo_bucket = kcalloc(IWPM_REMINFO_HASH_SIZE,
  					      sizeof(struct hlist_head),
  					      GFP_KERNEL);
  		if (!iwpm_reminfo_bucket) {
  			kfree(iwpm_hash_bucket);
  			ret = -ENOMEM;
  			goto init_exit;
  		}
  	}
  	atomic_inc(&iwpm_admin.refcount);
  init_exit:
  	mutex_unlock(&iwpm_admin_lock);
  	if (!ret) {
  		iwpm_set_valid(nl_client, 1);
  		iwpm_set_registration(nl_client, IWPM_REG_UNDEF);
  		pr_debug("%s: Mapinfo and reminfo tables are created\n",
  				__func__);
  	}
  	return ret;
  }
  
  static void free_hash_bucket(void);
  static void free_reminfo_bucket(void);
  
  int iwpm_exit(u8 nl_client)
  {
  
  	if (!iwpm_valid_client(nl_client))
  		return -EINVAL;
  	mutex_lock(&iwpm_admin_lock);
  	if (atomic_read(&iwpm_admin.refcount) == 0) {
  		mutex_unlock(&iwpm_admin_lock);
  		pr_err("%s Incorrect usage - negative refcount\n", __func__);
  		return -EINVAL;
  	}
  	if (atomic_dec_and_test(&iwpm_admin.refcount)) {
  		free_hash_bucket();
  		free_reminfo_bucket();
  		pr_debug("%s: Resources are destroyed\n", __func__);
  	}
  	mutex_unlock(&iwpm_admin_lock);
  	iwpm_set_valid(nl_client, 0);
  	iwpm_set_registration(nl_client, IWPM_REG_UNDEF);
  	return 0;
  }
  
  static struct hlist_head *get_mapinfo_hash_bucket(struct sockaddr_storage *,
  					       struct sockaddr_storage *);
  
  int iwpm_create_mapinfo(struct sockaddr_storage *local_sockaddr,
  			struct sockaddr_storage *mapped_sockaddr,
  			u8 nl_client)
  {
  	struct hlist_head *hash_bucket_head = NULL;
  	struct iwpm_mapping_info *map_info;
  	unsigned long flags;
  	int ret = -EINVAL;
  
  	if (!iwpm_valid_client(nl_client))
  		return ret;
  	map_info = kzalloc(sizeof(struct iwpm_mapping_info), GFP_KERNEL);
  	if (!map_info)
  		return -ENOMEM;
  
  	memcpy(&map_info->local_sockaddr, local_sockaddr,
  	       sizeof(struct sockaddr_storage));
  	memcpy(&map_info->mapped_sockaddr, mapped_sockaddr,
  	       sizeof(struct sockaddr_storage));
  	map_info->nl_client = nl_client;
  
  	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
  	if (iwpm_hash_bucket) {
  		hash_bucket_head = get_mapinfo_hash_bucket(
  					&map_info->local_sockaddr,
  					&map_info->mapped_sockaddr);
  		if (hash_bucket_head) {
  			hlist_add_head(&map_info->hlist_node, hash_bucket_head);
  			ret = 0;
  		}
  	}
  	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
  
  	if (!hash_bucket_head)
  		kfree(map_info);
  	return ret;
  }
  
  int iwpm_remove_mapinfo(struct sockaddr_storage *local_sockaddr,
  			struct sockaddr_storage *mapped_local_addr)
  {
  	struct hlist_node *tmp_hlist_node;
  	struct hlist_head *hash_bucket_head;
  	struct iwpm_mapping_info *map_info = NULL;
  	unsigned long flags;
  	int ret = -EINVAL;
  
  	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
  	if (iwpm_hash_bucket) {
  		hash_bucket_head = get_mapinfo_hash_bucket(
  					local_sockaddr,
  					mapped_local_addr);
  		if (!hash_bucket_head)
  			goto remove_mapinfo_exit;
  
  		hlist_for_each_entry_safe(map_info, tmp_hlist_node,
  					hash_bucket_head, hlist_node) {
  
  			if (!iwpm_compare_sockaddr(&map_info->mapped_sockaddr,
  						mapped_local_addr)) {
  
  				hlist_del_init(&map_info->hlist_node);
  				kfree(map_info);
  				ret = 0;
  				break;
  			}
  		}
  	}
  remove_mapinfo_exit:
  	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
  	return ret;
  }
  
  static void free_hash_bucket(void)
  {
  	struct hlist_node *tmp_hlist_node;
  	struct iwpm_mapping_info *map_info;
  	unsigned long flags;
  	int i;
  
  	/* remove all the mapinfo data from the list */
  	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
  	for (i = 0; i < IWPM_MAPINFO_HASH_SIZE; i++) {
  		hlist_for_each_entry_safe(map_info, tmp_hlist_node,
  			&iwpm_hash_bucket[i], hlist_node) {
  
  				hlist_del_init(&map_info->hlist_node);
  				kfree(map_info);
  			}
  	}
  	/* free the hash list */
  	kfree(iwpm_hash_bucket);
  	iwpm_hash_bucket = NULL;
  	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
  }
  
  static void free_reminfo_bucket(void)
  {
  	struct hlist_node *tmp_hlist_node;
  	struct iwpm_remote_info *rem_info;
  	unsigned long flags;
  	int i;
  
  	/* remove all the remote info from the list */
  	spin_lock_irqsave(&iwpm_reminfo_lock, flags);
  	for (i = 0; i < IWPM_REMINFO_HASH_SIZE; i++) {
  		hlist_for_each_entry_safe(rem_info, tmp_hlist_node,
  			&iwpm_reminfo_bucket[i], hlist_node) {
  
  				hlist_del_init(&rem_info->hlist_node);
  				kfree(rem_info);
  			}
  	}
  	/* free the hash list */
  	kfree(iwpm_reminfo_bucket);
  	iwpm_reminfo_bucket = NULL;
  	spin_unlock_irqrestore(&iwpm_reminfo_lock, flags);
  }
  
  static struct hlist_head *get_reminfo_hash_bucket(struct sockaddr_storage *,
  						struct sockaddr_storage *);
  
  void iwpm_add_remote_info(struct iwpm_remote_info *rem_info)
  {
  	struct hlist_head *hash_bucket_head;
  	unsigned long flags;
  
  	spin_lock_irqsave(&iwpm_reminfo_lock, flags);
  	if (iwpm_reminfo_bucket) {
  		hash_bucket_head = get_reminfo_hash_bucket(
  					&rem_info->mapped_loc_sockaddr,
  					&rem_info->mapped_rem_sockaddr);
  		if (hash_bucket_head)
  			hlist_add_head(&rem_info->hlist_node, hash_bucket_head);
  	}
  	spin_unlock_irqrestore(&iwpm_reminfo_lock, flags);
  }
  
  int iwpm_get_remote_info(struct sockaddr_storage *mapped_loc_addr,
  			 struct sockaddr_storage *mapped_rem_addr,
  			 struct sockaddr_storage *remote_addr,
  			 u8 nl_client)
  {
  	struct hlist_node *tmp_hlist_node;
  	struct hlist_head *hash_bucket_head;
  	struct iwpm_remote_info *rem_info = NULL;
  	unsigned long flags;
  	int ret = -EINVAL;
  
  	if (!iwpm_valid_client(nl_client)) {
  		pr_info("%s: Invalid client = %d\n", __func__, nl_client);
  		return ret;
  	}
  	spin_lock_irqsave(&iwpm_reminfo_lock, flags);
  	if (iwpm_reminfo_bucket) {
  		hash_bucket_head = get_reminfo_hash_bucket(
  					mapped_loc_addr,
  					mapped_rem_addr);
  		if (!hash_bucket_head)
  			goto get_remote_info_exit;
  		hlist_for_each_entry_safe(rem_info, tmp_hlist_node,
  					hash_bucket_head, hlist_node) {
  
  			if (!iwpm_compare_sockaddr(&rem_info->mapped_loc_sockaddr,
  				mapped_loc_addr) &&
  				!iwpm_compare_sockaddr(&rem_info->mapped_rem_sockaddr,
  				mapped_rem_addr)) {
  
  				memcpy(remote_addr, &rem_info->remote_sockaddr,
  					sizeof(struct sockaddr_storage));
  				iwpm_print_sockaddr(remote_addr,
  						"get_remote_info: Remote sockaddr:");
  
  				hlist_del_init(&rem_info->hlist_node);
  				kfree(rem_info);
  				ret = 0;
  				break;
  			}
  		}
  	}
  get_remote_info_exit:
  	spin_unlock_irqrestore(&iwpm_reminfo_lock, flags);
  	return ret;
  }
  
  struct iwpm_nlmsg_request *iwpm_get_nlmsg_request(__u32 nlmsg_seq,
  					u8 nl_client, gfp_t gfp)
  {
  	struct iwpm_nlmsg_request *nlmsg_request = NULL;
  	unsigned long flags;
  
  	nlmsg_request = kzalloc(sizeof(struct iwpm_nlmsg_request), gfp);
  	if (!nlmsg_request)
  		return NULL;
  
  	spin_lock_irqsave(&iwpm_nlmsg_req_lock, flags);
  	list_add_tail(&nlmsg_request->inprocess_list, &iwpm_nlmsg_req_list);
  	spin_unlock_irqrestore(&iwpm_nlmsg_req_lock, flags);
  
  	kref_init(&nlmsg_request->kref);
  	kref_get(&nlmsg_request->kref);
  	nlmsg_request->nlmsg_seq = nlmsg_seq;
  	nlmsg_request->nl_client = nl_client;
  	nlmsg_request->request_done = 0;
  	nlmsg_request->err_code = 0;
  	sema_init(&nlmsg_request->sem, 1);
  	down(&nlmsg_request->sem);
  	return nlmsg_request;
  }
  
  void iwpm_free_nlmsg_request(struct kref *kref)
  {
  	struct iwpm_nlmsg_request *nlmsg_request;
  	unsigned long flags;
  
  	nlmsg_request = container_of(kref, struct iwpm_nlmsg_request, kref);
  
  	spin_lock_irqsave(&iwpm_nlmsg_req_lock, flags);
  	list_del_init(&nlmsg_request->inprocess_list);
  	spin_unlock_irqrestore(&iwpm_nlmsg_req_lock, flags);
  
  	if (!nlmsg_request->request_done)
  		pr_debug("%s Freeing incomplete nlmsg request (seq = %u).\n",
  			__func__, nlmsg_request->nlmsg_seq);
  	kfree(nlmsg_request);
  }
  
  struct iwpm_nlmsg_request *iwpm_find_nlmsg_request(__u32 echo_seq)
  {
  	struct iwpm_nlmsg_request *nlmsg_request;
  	struct iwpm_nlmsg_request *found_request = NULL;
  	unsigned long flags;
  
  	spin_lock_irqsave(&iwpm_nlmsg_req_lock, flags);
  	list_for_each_entry(nlmsg_request, &iwpm_nlmsg_req_list,
  			    inprocess_list) {
  		if (nlmsg_request->nlmsg_seq == echo_seq) {
  			found_request = nlmsg_request;
  			kref_get(&nlmsg_request->kref);
  			break;
  		}
  	}
  	spin_unlock_irqrestore(&iwpm_nlmsg_req_lock, flags);
  	return found_request;
  }
  
  int iwpm_wait_complete_req(struct iwpm_nlmsg_request *nlmsg_request)
  {
  	int ret;
  
  	ret = down_timeout(&nlmsg_request->sem, IWPM_NL_TIMEOUT);
  	if (ret) {
  		ret = -EINVAL;
  		pr_info("%s: Timeout %d sec for netlink request (seq = %u)\n",
  			__func__, (IWPM_NL_TIMEOUT/HZ), nlmsg_request->nlmsg_seq);
  	} else {
  		ret = nlmsg_request->err_code;
  	}
  	kref_put(&nlmsg_request->kref, iwpm_free_nlmsg_request);
  	return ret;
  }
  
  int iwpm_get_nlmsg_seq(void)
  {
  	return atomic_inc_return(&iwpm_admin.nlmsg_seq);
  }
  
  int iwpm_valid_client(u8 nl_client)
  {
  	return iwpm_admin.client_list[nl_client];
  }
  
  void iwpm_set_valid(u8 nl_client, int valid)
  {
  	iwpm_admin.client_list[nl_client] = valid;
  }
  
  /* valid client */
  u32 iwpm_get_registration(u8 nl_client)
  {
  	return iwpm_admin.reg_list[nl_client];
  }
  
  /* valid client */
  void iwpm_set_registration(u8 nl_client, u32 reg)
  {
  	iwpm_admin.reg_list[nl_client] = reg;
  }
  
  /* valid client */
  u32 iwpm_check_registration(u8 nl_client, u32 reg)
  {
  	return (iwpm_get_registration(nl_client) & reg);
  }
  
  int iwpm_compare_sockaddr(struct sockaddr_storage *a_sockaddr,
  				struct sockaddr_storage *b_sockaddr)
  {
  	if (a_sockaddr->ss_family != b_sockaddr->ss_family)
  		return 1;
  	if (a_sockaddr->ss_family == AF_INET) {
  		struct sockaddr_in *a4_sockaddr =
  			(struct sockaddr_in *)a_sockaddr;
  		struct sockaddr_in *b4_sockaddr =
  			(struct sockaddr_in *)b_sockaddr;
  		if (!memcmp(&a4_sockaddr->sin_addr,
  			&b4_sockaddr->sin_addr, sizeof(struct in_addr))
  			&& a4_sockaddr->sin_port == b4_sockaddr->sin_port)
  				return 0;
  
  	} else if (a_sockaddr->ss_family == AF_INET6) {
  		struct sockaddr_in6 *a6_sockaddr =
  			(struct sockaddr_in6 *)a_sockaddr;
  		struct sockaddr_in6 *b6_sockaddr =
  			(struct sockaddr_in6 *)b_sockaddr;
  		if (!memcmp(&a6_sockaddr->sin6_addr,
  			&b6_sockaddr->sin6_addr, sizeof(struct in6_addr))
  			&& a6_sockaddr->sin6_port == b6_sockaddr->sin6_port)
  				return 0;
  
  	} else {
  		pr_err("%s: Invalid sockaddr family\n", __func__);
  	}
  	return 1;
  }
  
  struct sk_buff *iwpm_create_nlmsg(u32 nl_op, struct nlmsghdr **nlh,
  						int nl_client)
  {
  	struct sk_buff *skb = NULL;
  
  	skb = dev_alloc_skb(IWPM_MSG_SIZE);
  	if (!skb)
  		goto create_nlmsg_exit;
  
  	if (!(ibnl_put_msg(skb, nlh, 0, 0, nl_client, nl_op,
  			   NLM_F_REQUEST))) {
  		pr_warn("%s: Unable to put the nlmsg header\n", __func__);
  		dev_kfree_skb(skb);
  		skb = NULL;
  	}
  create_nlmsg_exit:
  	return skb;
  }
  
  int iwpm_parse_nlmsg(struct netlink_callback *cb, int policy_max,
  				   const struct nla_policy *nlmsg_policy,
  				   struct nlattr *nltb[], const char *msg_type)
  {
  	int nlh_len = 0;
  	int ret;
  	const char *err_str = "";
  
  	ret = nlmsg_validate(cb->nlh, nlh_len, policy_max - 1, nlmsg_policy,
  			     NULL);
  	if (ret) {
  		err_str = "Invalid attribute";
  		goto parse_nlmsg_error;
  	}
  	ret = nlmsg_parse(cb->nlh, nlh_len, nltb, policy_max - 1,
  			  nlmsg_policy, NULL);
  	if (ret) {
  		err_str = "Unable to parse the nlmsg";
  		goto parse_nlmsg_error;
  	}
  	ret = iwpm_validate_nlmsg_attr(nltb, policy_max);
  	if (ret) {
  		err_str = "Invalid NULL attribute";
  		goto parse_nlmsg_error;
  	}
  	return 0;
  parse_nlmsg_error:
  	pr_warn("%s: %s (msg type %s ret = %d)\n",
  			__func__, err_str, msg_type, ret);
  	return ret;
  }
  
  void iwpm_print_sockaddr(struct sockaddr_storage *sockaddr, char *msg)
  {
  	struct sockaddr_in6 *sockaddr_v6;
  	struct sockaddr_in *sockaddr_v4;
  
  	switch (sockaddr->ss_family) {
  	case AF_INET:
  		sockaddr_v4 = (struct sockaddr_in *)sockaddr;
  		pr_debug("%s IPV4 %pI4: %u(0x%04X)\n",
  			msg, &sockaddr_v4->sin_addr,
  			ntohs(sockaddr_v4->sin_port),
  			ntohs(sockaddr_v4->sin_port));
  		break;
  	case AF_INET6:
  		sockaddr_v6 = (struct sockaddr_in6 *)sockaddr;
  		pr_debug("%s IPV6 %pI6: %u(0x%04X)\n",
  			msg, &sockaddr_v6->sin6_addr,
  			ntohs(sockaddr_v6->sin6_port),
  			ntohs(sockaddr_v6->sin6_port));
  		break;
  	default:
  		break;
  	}
  }
  
  static u32 iwpm_ipv6_jhash(struct sockaddr_in6 *ipv6_sockaddr)
  {
  	u32 ipv6_hash = jhash(&ipv6_sockaddr->sin6_addr, sizeof(struct in6_addr), 0);
  	u32 hash = jhash_2words(ipv6_hash, (__force u32) ipv6_sockaddr->sin6_port, 0);
  	return hash;
  }
  
  static u32 iwpm_ipv4_jhash(struct sockaddr_in *ipv4_sockaddr)
  {
  	u32 ipv4_hash = jhash(&ipv4_sockaddr->sin_addr, sizeof(struct in_addr), 0);
  	u32 hash = jhash_2words(ipv4_hash, (__force u32) ipv4_sockaddr->sin_port, 0);
  	return hash;
  }
  
  static int get_hash_bucket(struct sockaddr_storage *a_sockaddr,
  				struct sockaddr_storage *b_sockaddr, u32 *hash)
  {
  	u32 a_hash, b_hash;
  
  	if (a_sockaddr->ss_family == AF_INET) {
  		a_hash = iwpm_ipv4_jhash((struct sockaddr_in *) a_sockaddr);
  		b_hash = iwpm_ipv4_jhash((struct sockaddr_in *) b_sockaddr);
  
  	} else if (a_sockaddr->ss_family == AF_INET6) {
  		a_hash = iwpm_ipv6_jhash((struct sockaddr_in6 *) a_sockaddr);
  		b_hash = iwpm_ipv6_jhash((struct sockaddr_in6 *) b_sockaddr);
  	} else {
  		pr_err("%s: Invalid sockaddr family\n", __func__);
  		return -EINVAL;
  	}
  
  	if (a_hash == b_hash) /* if port mapper isn't available */
  		*hash = a_hash;
  	else
  		*hash = jhash_2words(a_hash, b_hash, 0);
  	return 0;
  }
  
  static struct hlist_head *get_mapinfo_hash_bucket(struct sockaddr_storage
  				*local_sockaddr, struct sockaddr_storage
  				*mapped_sockaddr)
  {
  	u32 hash;
  	int ret;
  
  	ret = get_hash_bucket(local_sockaddr, mapped_sockaddr, &hash);
  	if (ret)
  		return NULL;
  	return &iwpm_hash_bucket[hash & IWPM_MAPINFO_HASH_MASK];
  }
  
  static struct hlist_head *get_reminfo_hash_bucket(struct sockaddr_storage
  				*mapped_loc_sockaddr, struct sockaddr_storage
  				*mapped_rem_sockaddr)
  {
  	u32 hash;
  	int ret;
  
  	ret = get_hash_bucket(mapped_loc_sockaddr, mapped_rem_sockaddr, &hash);
  	if (ret)
  		return NULL;
  	return &iwpm_reminfo_bucket[hash & IWPM_REMINFO_HASH_MASK];
  }
  
  static int send_mapinfo_num(u32 mapping_num, u8 nl_client, int iwpm_pid)
  {
  	struct sk_buff *skb = NULL;
  	struct nlmsghdr *nlh;
  	u32 msg_seq;
  	const char *err_str = "";
  	int ret = -EINVAL;
  
  	skb = iwpm_create_nlmsg(RDMA_NL_IWPM_MAPINFO_NUM, &nlh, nl_client);
  	if (!skb) {
  		err_str = "Unable to create a nlmsg";
  		goto mapinfo_num_error;
  	}
  	nlh->nlmsg_seq = iwpm_get_nlmsg_seq();
  	msg_seq = 0;
  	err_str = "Unable to put attribute of mapinfo number nlmsg";
  	ret = ibnl_put_attr(skb, nlh, sizeof(u32), &msg_seq, IWPM_NLA_MAPINFO_SEQ);
  	if (ret)
  		goto mapinfo_num_error;
  	ret = ibnl_put_attr(skb, nlh, sizeof(u32),
  				&mapping_num, IWPM_NLA_MAPINFO_SEND_NUM);
  	if (ret)
  		goto mapinfo_num_error;
  
  	nlmsg_end(skb, nlh);
  
  	ret = rdma_nl_unicast(skb, iwpm_pid);
  	if (ret) {
  		skb = NULL;
  		err_str = "Unable to send a nlmsg";
  		goto mapinfo_num_error;
  	}
  	pr_debug("%s: Sent mapping number = %d\n", __func__, mapping_num);
  	return 0;
  mapinfo_num_error:
  	pr_info("%s: %s\n", __func__, err_str);
  	if (skb)
  		dev_kfree_skb(skb);
  	return ret;
  }
  
  static int send_nlmsg_done(struct sk_buff *skb, u8 nl_client, int iwpm_pid)
  {
  	struct nlmsghdr *nlh = NULL;
  	int ret = 0;
  
  	if (!skb)
  		return ret;
  	if (!(ibnl_put_msg(skb, &nlh, 0, 0, nl_client,
  			   RDMA_NL_IWPM_MAPINFO, NLM_F_MULTI))) {
  		pr_warn("%s Unable to put NLMSG_DONE\n", __func__);
  		dev_kfree_skb(skb);
  		return -ENOMEM;
  	}
  	nlh->nlmsg_type = NLMSG_DONE;
  	ret = rdma_nl_unicast(skb, iwpm_pid);
  	if (ret)
  		pr_warn("%s Unable to send a nlmsg\n", __func__);
  	return ret;
  }
  
  int iwpm_send_mapinfo(u8 nl_client, int iwpm_pid)
  {
  	struct iwpm_mapping_info *map_info;
  	struct sk_buff *skb = NULL;
  	struct nlmsghdr *nlh;
  	int skb_num = 0, mapping_num = 0;
  	int i = 0, nlmsg_bytes = 0;
  	unsigned long flags;
  	const char *err_str = "";
  	int ret;
  
  	skb = dev_alloc_skb(NLMSG_GOODSIZE);
  	if (!skb) {
  		ret = -ENOMEM;
  		err_str = "Unable to allocate skb";
  		goto send_mapping_info_exit;
  	}
  	skb_num++;
  	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
  	ret = -EINVAL;
  	for (i = 0; i < IWPM_MAPINFO_HASH_SIZE; i++) {
  		hlist_for_each_entry(map_info, &iwpm_hash_bucket[i],
  				     hlist_node) {
  			if (map_info->nl_client != nl_client)
  				continue;
  			nlh = NULL;
  			if (!(ibnl_put_msg(skb, &nlh, 0, 0, nl_client,
  					RDMA_NL_IWPM_MAPINFO, NLM_F_MULTI))) {
  				ret = -ENOMEM;
  				err_str = "Unable to put the nlmsg header";
  				goto send_mapping_info_unlock;
  			}
  			err_str = "Unable to put attribute of the nlmsg";
  			ret = ibnl_put_attr(skb, nlh,
  					sizeof(struct sockaddr_storage),
  					&map_info->local_sockaddr,
  					IWPM_NLA_MAPINFO_LOCAL_ADDR);
  			if (ret)
  				goto send_mapping_info_unlock;
  
  			ret = ibnl_put_attr(skb, nlh,
  					sizeof(struct sockaddr_storage),
  					&map_info->mapped_sockaddr,
  					IWPM_NLA_MAPINFO_MAPPED_ADDR);
  			if (ret)
  				goto send_mapping_info_unlock;
  
  			nlmsg_end(skb, nlh);
  
  			iwpm_print_sockaddr(&map_info->local_sockaddr,
  				"send_mapping_info: Local sockaddr:");
  			iwpm_print_sockaddr(&map_info->mapped_sockaddr,
  				"send_mapping_info: Mapped local sockaddr:");
  			mapping_num++;
  			nlmsg_bytes += nlh->nlmsg_len;
  
  			/* check if all mappings can fit in one skb */
  			if (NLMSG_GOODSIZE - nlmsg_bytes < nlh->nlmsg_len * 2) {
  				/* and leave room for NLMSG_DONE */
  				nlmsg_bytes = 0;
  				skb_num++;
  				spin_unlock_irqrestore(&iwpm_mapinfo_lock,
  						       flags);
  				/* send the skb */
  				ret = send_nlmsg_done(skb, nl_client, iwpm_pid);
  				skb = NULL;
  				if (ret) {
  					err_str = "Unable to send map info";
  					goto send_mapping_info_exit;
  				}
  				if (skb_num == IWPM_MAPINFO_SKB_COUNT) {
  					ret = -ENOMEM;
  					err_str = "Insufficient skbs for map info";
  					goto send_mapping_info_exit;
  				}
  				skb = dev_alloc_skb(NLMSG_GOODSIZE);
  				if (!skb) {
  					ret = -ENOMEM;
  					err_str = "Unable to allocate skb";
  					goto send_mapping_info_exit;
  				}
  				spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
  			}
  		}
  	}
  send_mapping_info_unlock:
  	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
  send_mapping_info_exit:
  	if (ret) {
  		pr_warn("%s: %s (ret = %d)\n", __func__, err_str, ret);
  		if (skb)
  			dev_kfree_skb(skb);
  		return ret;
  	}
  	send_nlmsg_done(skb, nl_client, iwpm_pid);
  	return send_mapinfo_num(mapping_num, nl_client, iwpm_pid);
  }
  
  int iwpm_mapinfo_available(void)
  {
  	unsigned long flags;
  	int full_bucket = 0, i = 0;
  
  	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
  	if (iwpm_hash_bucket) {
  		for (i = 0; i < IWPM_MAPINFO_HASH_SIZE; i++) {
  			if (!hlist_empty(&iwpm_hash_bucket[i])) {
  				full_bucket = 1;
  				break;
  			}
  		}
  	}
  	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
  	return full_bucket;
  }
  