[for-4.1,1/3] RDMA/core: Enable the iWarp Port Mapper to provide the actual address of the remote connecting peer

Commit Message

Nikolova, Tatyana E April 17, 2015, 10:54 p.m. UTC

This patch series was first submitted for inclusion upstream on 10/13/14, but
it seems to have slipped through the cracks.

Add functionality to allow the port mapper to provide to its client
the actual (non-mapped) ip/tcp address information of the remote connecting peer

1) Adding remote_info_cb() to process the address info of
   the remote peer when it initiates the connection
2) Adding a hash list to store the remote address info
3) Adding functionality to add/remove the remote address info
   After the info has been provided to the port mapper client,
   it is removed from the hash list 


The port mapper client needs to know the actual (non-mapped) address info of 
the remote peer for each connection, because it is reporting it to the
user space application which isn't aware of the port mapper service. 
(The clients already know the local non-mapped address info)


Signed-off-by: Tatyana Nikolova <[e-mail]>
Reviewed-by: Steve Wise <[e-mail]>
---
 drivers/infiniband/core/iwpm_msg.c  |   73 ++++++++++++-
 drivers/infiniband/core/iwpm_util.c |  208 +++++++++++++++++++++++++++++------
 drivers/infiniband/core/iwpm_util.h |   15 +++
 include/rdma/iw_portmap.h           |   25 ++++
 include/uapi/rdma/rdma_netlink.h    |    1 +
 5 files changed, 288 insertions(+), 34 deletions(-)

Comments

Or Gerlitz April 19, 2015, 11:57 a.m. UTC | #1

On 4/18/2015 1:54 AM, Tatyana Nikolova wrote:
> This patch series was first submitted for inclusion upstream on 10/13/14, but
> it seems to have slipped through the cracks.

The above text is irrelevant for the kernel git logs, can you re-send 
with proper cover letter explaining what this series is about.

>
> Add functionality to allow the port mapper to provide to its client
> the actual (non-mapped) ip/tcp address information of the remote connecting peer

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Patch

diff --git a/drivers/infiniband/core/iwpm_msg.c b/drivers/infiniband/core/iwpm_msg.c
index b85ddbc..ab08170 100644
--- a/drivers/infiniband/core/iwpm_msg.c
+++ b/drivers/infiniband/core/iwpm_msg.c
@@ -468,7 +468,8 @@  add_mapping_response_exit:
 }
 EXPORT_SYMBOL(iwpm_add_mapping_cb);
 
-/* netlink attribute policy for the response to add and query mapping request */
+/* netlink attribute policy for the response to add and query mapping request
+ * and response with remote address info */
 static const struct nla_policy resp_query_policy[IWPM_NLA_RQUERY_MAPPING_MAX] = {
 	[IWPM_NLA_QUERY_MAPPING_SEQ]      = { .type = NLA_U32 },
 	[IWPM_NLA_QUERY_LOCAL_ADDR]       = { .len = sizeof(struct sockaddr_storage) },
@@ -559,6 +560,76 @@  query_mapping_response_exit:
 }
 EXPORT_SYMBOL(iwpm_add_and_query_mapping_cb);
 
+/*
+ * iwpm_remote_info_cb - Process a port mapper message, containing
+ *			  the remote connecting peer address info
+ */
+int iwpm_remote_info_cb(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct nlattr *nltb[IWPM_NLA_RQUERY_MAPPING_MAX];
+	struct sockaddr_storage *local_sockaddr, *remote_sockaddr;
+	struct sockaddr_storage *mapped_loc_sockaddr, *mapped_rem_sockaddr;
+	struct iwpm_remote_info *rem_info;
+	const char *msg_type;
+	u8 nl_client;
+	int ret = -EINVAL;
+
+	msg_type = "Remote Mapping info";
+	if (iwpm_parse_nlmsg(cb, IWPM_NLA_RQUERY_MAPPING_MAX,
+				resp_query_policy, nltb, msg_type))
+		return ret;
+
+	nl_client = RDMA_NL_GET_CLIENT(cb->nlh->nlmsg_type);
+	if (!iwpm_valid_client(nl_client)) {
+		pr_info("%s: Invalid port mapper client = %d\n",
+				__func__, nl_client);
+		return ret;
+	}
+	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
+
+	local_sockaddr = (struct sockaddr_storage *)
+			nla_data(nltb[IWPM_NLA_QUERY_LOCAL_ADDR]);
+	remote_sockaddr = (struct sockaddr_storage *)
+			nla_data(nltb[IWPM_NLA_QUERY_REMOTE_ADDR]);
+	mapped_loc_sockaddr = (struct sockaddr_storage *)
+			nla_data(nltb[IWPM_NLA_RQUERY_MAPPED_LOC_ADDR]);
+	mapped_rem_sockaddr = (struct sockaddr_storage *)
+			nla_data(nltb[IWPM_NLA_RQUERY_MAPPED_REM_ADDR]);
+
+	if (mapped_loc_sockaddr->ss_family != local_sockaddr->ss_family ||
+		mapped_rem_sockaddr->ss_family != remote_sockaddr->ss_family) {
+		pr_info("%s: Sockaddr family doesn't match the requested one\n",
+				__func__);
+		return ret;
+	}
+	rem_info = kzalloc(sizeof(struct iwpm_remote_info), GFP_ATOMIC);
+	if (!rem_info) {
+		pr_err("%s: Unable to allocate a remote info\n", __func__);
+		ret = -ENOMEM;
+		return ret;
+	}
+	memcpy(&rem_info->mapped_loc_sockaddr, mapped_loc_sockaddr,
+	       sizeof(struct sockaddr_storage));
+	memcpy(&rem_info->remote_sockaddr, remote_sockaddr,
+	       sizeof(struct sockaddr_storage));
+	memcpy(&rem_info->mapped_rem_sockaddr, mapped_rem_sockaddr,
+	       sizeof(struct sockaddr_storage));
+	rem_info->nl_client = nl_client;
+
+	iwpm_add_remote_info(rem_info);
+
+	iwpm_print_sockaddr(local_sockaddr,
+			"remote_info: Local sockaddr:");
+	iwpm_print_sockaddr(mapped_loc_sockaddr,
+			"remote_info: Mapped local sockaddr:");
+	iwpm_print_sockaddr(remote_sockaddr,
+			"remote_info: Remote sockaddr:");
+	iwpm_print_sockaddr(mapped_rem_sockaddr,
+			"remote_info: Mapped remote sockaddr:");
+	return ret;
+}
+EXPORT_SYMBOL(iwpm_remote_info_cb);
+
 /* netlink attribute policy for the received request for mapping info */
 static const struct nla_policy resp_mapinfo_policy[IWPM_NLA_MAPINFO_REQ_MAX] = {
 	[IWPM_NLA_MAPINFO_ULIB_NAME] = { .type = NLA_STRING,
diff --git a/drivers/infiniband/core/iwpm_util.c b/drivers/infiniband/core/iwpm_util.c
index 69e9f84..d1b24d2 100644
--- a/drivers/infiniband/core/iwpm_util.c
+++ b/drivers/infiniband/core/iwpm_util.c
@@ -33,8 +33,10 @@ 
 
 #include "iwpm_util.h"
 
-#define IWPM_HASH_BUCKET_SIZE	512
-#define IWPM_HASH_BUCKET_MASK	(IWPM_HASH_BUCKET_SIZE - 1)
+#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)
 
 static LIST_HEAD(iwpm_nlmsg_req_list);
 static DEFINE_SPINLOCK(iwpm_nlmsg_req_lock);
@@ -42,31 +45,49 @@  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;
 	if (iwpm_valid_client(nl_client))
 		return -EINVAL;
 	mutex_lock(&iwpm_admin_lock);
 	if (atomic_read(&iwpm_admin.refcount) == 0) {
-		iwpm_hash_bucket = kzalloc(IWPM_HASH_BUCKET_SIZE *
+		iwpm_hash_bucket = kzalloc(IWPM_MAPINFO_HASH_SIZE *
 					sizeof(struct hlist_head), GFP_KERNEL);
 		if (!iwpm_hash_bucket) {
-			mutex_unlock(&iwpm_admin_lock);
+			ret = -ENOMEM;
 			pr_err("%s Unable to create mapinfo hash table\n", __func__);
-			return -ENOMEM;
+			goto init_exit;
+		}
+		iwpm_reminfo_bucket = kzalloc(IWPM_REMINFO_HASH_SIZE *
+					sizeof(struct hlist_head), GFP_KERNEL);
+		if (!iwpm_reminfo_bucket) {
+			kfree(iwpm_hash_bucket);
+			ret = -ENOMEM;
+			pr_err("%s Unable to create reminfo hash table\n", __func__);
+			goto init_exit;
 		}
 	}
 	atomic_inc(&iwpm_admin.refcount);
+init_exit:
 	mutex_unlock(&iwpm_admin_lock);
-	iwpm_set_valid(nl_client, 1);
-	return 0;
+	if (!ret) {
+		iwpm_set_valid(nl_client, 1);
+		pr_debug("%s: Mapinfo and reminfo tables are created\n",
+				__func__);
+	}
+	return ret;
 }
 EXPORT_SYMBOL(iwpm_init);
 
 static void free_hash_bucket(void);
+static void free_reminfo_bucket(void);
 
 int iwpm_exit(u8 nl_client)
 {
@@ -81,7 +100,8 @@  int iwpm_exit(u8 nl_client)
 	}
 	if (atomic_dec_and_test(&iwpm_admin.refcount)) {
 		free_hash_bucket();
-		pr_debug("%s: Mapinfo hash table is destroyed\n", __func__);
+		free_reminfo_bucket();
+		pr_debug("%s: Resources are destroyed\n", __func__);
 	}
 	mutex_unlock(&iwpm_admin_lock);
 	iwpm_set_valid(nl_client, 0);
@@ -89,7 +109,7 @@  int iwpm_exit(u8 nl_client)
 }
 EXPORT_SYMBOL(iwpm_exit);
 
-static struct hlist_head *get_hash_bucket_head(struct sockaddr_storage *,
+static struct hlist_head *get_mapinfo_hash_bucket(struct sockaddr_storage *,
 					       struct sockaddr_storage *);
 
 int iwpm_create_mapinfo(struct sockaddr_storage *local_sockaddr,
@@ -99,9 +119,10 @@  int iwpm_create_mapinfo(struct sockaddr_storage *local_sockaddr,
 	struct hlist_head *hash_bucket_head;
 	struct iwpm_mapping_info *map_info;
 	unsigned long flags;
+	int ret = -EINVAL;
 
 	if (!iwpm_valid_client(nl_client))
-		return -EINVAL;
+		return ret;
 	map_info = kzalloc(sizeof(struct iwpm_mapping_info), GFP_KERNEL);
 	if (!map_info) {
 		pr_err("%s: Unable to allocate a mapping info\n", __func__);
@@ -115,13 +136,16 @@  int iwpm_create_mapinfo(struct sockaddr_storage *local_sockaddr,
 
 	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
 	if (iwpm_hash_bucket) {
-		hash_bucket_head = get_hash_bucket_head(
+		hash_bucket_head = get_mapinfo_hash_bucket(
 					&map_info->local_sockaddr,
 					&map_info->mapped_sockaddr);
-		hlist_add_head(&map_info->hlist_node, hash_bucket_head);
+		if (hash_bucket_head) {
+			hlist_add_head(&map_info->hlist_node, hash_bucket_head);
+			ret = 0;
+		}
 	}
 	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL(iwpm_create_mapinfo);
 
@@ -136,9 +160,12 @@  int iwpm_remove_mapinfo(struct sockaddr_storage *local_sockaddr,
 
 	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
 	if (iwpm_hash_bucket) {
-		hash_bucket_head = get_hash_bucket_head(
+		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) {
 
@@ -152,6 +179,7 @@  int iwpm_remove_mapinfo(struct sockaddr_storage *local_sockaddr,
 			}
 		}
 	}
+remove_mapinfo_exit:
 	spin_unlock_irqrestore(&iwpm_mapinfo_lock, flags);
 	return ret;
 }
@@ -166,7 +194,7 @@  static void free_hash_bucket(void)
 
 	/* remove all the mapinfo data from the list */
 	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
-	for (i = 0; i < IWPM_HASH_BUCKET_SIZE; i++) {
+	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) {
 
@@ -180,6 +207,96 @@  static void free_hash_bucket(void)
 	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;
+}
+EXPORT_SYMBOL(iwpm_get_remote_info);
+
 struct iwpm_nlmsg_request *iwpm_get_nlmsg_request(__u32 nlmsg_seq,
 					u8 nl_client, gfp_t gfp)
 {
@@ -409,31 +528,54 @@  static u32 iwpm_ipv4_jhash(struct sockaddr_in *ipv4_sockaddr)
 	return hash;
 }
 
-static struct hlist_head *get_hash_bucket_head(struct sockaddr_storage
-					       *local_sockaddr,
-					       struct sockaddr_storage
-					       *mapped_sockaddr)
+static int get_hash_bucket(struct sockaddr_storage *a_sockaddr,
+				struct sockaddr_storage *b_sockaddr, u32 *hash)
 {
-	u32 local_hash, mapped_hash, hash;
+	u32 a_hash, b_hash;
 
-	if (local_sockaddr->ss_family == AF_INET) {
-		local_hash = iwpm_ipv4_jhash((struct sockaddr_in *) local_sockaddr);
-		mapped_hash = iwpm_ipv4_jhash((struct sockaddr_in *) mapped_sockaddr);
+	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 (local_sockaddr->ss_family == AF_INET6) {
-		local_hash = iwpm_ipv6_jhash((struct sockaddr_in6 *) local_sockaddr);
-		mapped_hash = iwpm_ipv6_jhash((struct sockaddr_in6 *) mapped_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 NULL;
+		return -EINVAL;
 	}
 
-	if (local_hash == mapped_hash) /* if port mapper isn't available */
-		hash = local_hash;
+	if (a_hash == b_hash) /* if port mapper isn't available */
+		*hash = a_hash;
 	else
-		hash = jhash_2words(local_hash, mapped_hash, 0);
+		*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;
 
-	return &iwpm_hash_bucket[hash & IWPM_HASH_BUCKET_MASK];
+	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)
@@ -512,7 +654,7 @@  int iwpm_send_mapinfo(u8 nl_client, int iwpm_pid)
 	}
 	skb_num++;
 	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
-	for (i = 0; i < IWPM_HASH_BUCKET_SIZE; i++) {
+	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)
@@ -595,7 +737,7 @@  int iwpm_mapinfo_available(void)
 
 	spin_lock_irqsave(&iwpm_mapinfo_lock, flags);
 	if (iwpm_hash_bucket) {
-		for (i = 0; i < IWPM_HASH_BUCKET_SIZE; i++) {
+		for (i = 0; i < IWPM_MAPINFO_HASH_SIZE; i++) {
 			if (!hlist_empty(&iwpm_hash_bucket[i])) {
 				full_bucket = 1;
 				break;
diff --git a/drivers/infiniband/core/iwpm_util.h b/drivers/infiniband/core/iwpm_util.h
index 9777c86..ee2d9ff 100644
--- a/drivers/infiniband/core/iwpm_util.h
+++ b/drivers/infiniband/core/iwpm_util.h
@@ -76,6 +76,14 @@  struct iwpm_mapping_info {
 	u8     nl_client;
 };
 
+struct iwpm_remote_info {
+	struct hlist_node hlist_node;
+	struct sockaddr_storage remote_sockaddr;
+	struct sockaddr_storage mapped_loc_sockaddr;
+	struct sockaddr_storage mapped_rem_sockaddr;
+	u8     nl_client;
+};
+
 struct iwpm_admin_data {
 	atomic_t refcount;
 	atomic_t nlmsg_seq;
@@ -128,6 +136,13 @@  int iwpm_wait_complete_req(struct iwpm_nlmsg_request *nlmsg_request);
 int iwpm_get_nlmsg_seq(void);
 
 /**
+ * iwpm_add_reminfo - Add remote address info of the connecting peer
+ *                    to the remote info hash table
+ * @reminfo: The remote info to be added
+ */
+void iwpm_add_remote_info(struct iwpm_remote_info *reminfo);
+
+/**
  * iwpm_valid_client - Check if the port mapper client is valid
  * @nl_client: The index of the netlink client
  *
diff --git a/include/rdma/iw_portmap.h b/include/rdma/iw_portmap.h
index 928b277..fda3167 100644
--- a/include/rdma/iw_portmap.h
+++ b/include/rdma/iw_portmap.h
@@ -148,6 +148,16 @@  int iwpm_add_mapping_cb(struct sk_buff *, struct netlink_callback *);
 int iwpm_add_and_query_mapping_cb(struct sk_buff *, struct netlink_callback *);
 
 /**
+ * iwpm_remote_info_cb - Process remote connecting peer address info, which
+ *                       the port mapper has received from the connecting peer
+ *
+ * @cb: Contains the received message (payload and netlink header)
+ *
+ * Stores the IPv4/IPv6 address info in a hash table
+ */
+int iwpm_remote_info_cb(struct sk_buff *, struct netlink_callback *);
+
+/**
  * iwpm_mapping_error_cb - Process port mapper notification for error
  *
  * @skb:
@@ -175,6 +185,21 @@  int iwpm_mapping_info_cb(struct sk_buff *, struct netlink_callback *);
 int iwpm_ack_mapping_info_cb(struct sk_buff *, struct netlink_callback *);
 
 /**
+ * iwpm_get_remote_info - Get the remote connecting peer address info
+ *
+ * @mapped_loc_addr: Mapped local address of the listening peer
+ * @mapped_rem_addr: Mapped remote address of the connecting peer
+ * @remote_addr: To store the remote address of the connecting peer
+ * @nl_client: The index of the netlink client
+ *
+ * The remote address info is retrieved and provided to the client in
+ * the remote_addr. After that it is removed from the hash table
+ */
+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);
+
+/**
  * iwpm_create_mapinfo - Store local and mapped IPv4/IPv6 address
  *                       info in a hash table
  * @local_addr: Local ip/tcp address
diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
index de69170..6e4bb42 100644
--- a/include/uapi/rdma/rdma_netlink.h
+++ b/include/uapi/rdma/rdma_netlink.h
@@ -37,6 +37,7 @@  enum {
 	RDMA_NL_IWPM_ADD_MAPPING,
 	RDMA_NL_IWPM_QUERY_MAPPING,
 	RDMA_NL_IWPM_REMOVE_MAPPING,
+	RDMA_NL_IWPM_REMOTE_INFO,
 	RDMA_NL_IWPM_HANDLE_ERR,
 	RDMA_NL_IWPM_MAPINFO,
 	RDMA_NL_IWPM_MAPINFO_NUM,