RDMA/core: Add support for iWARP Port Mapper user space service

This patch adds iWARP Port Mapper (IWPM) Version 2 support.  The iWARP
Port Mapper implementation is based on the port mapper specification
section in the Sockets Direct Protocol paper -
http://www.rdmaconsortium.org/home/draft-pinkerton-iwarp-sdp-v1.0.pdf

Existing iWARP RDMA providers use the same IP address as the native
TCP/IP stack when creating RDMA connections.  They need a mechanism to
claim the TCP ports used for RDMA connections to prevent TCP port
collisions when other host applications use TCP ports.  The iWARP Port
Mapper provides a standard mechanism to accomplish this.  Without this
service it is possible for RDMA application to bind/listen on the same
port which is already being used by native TCP host application.  If
that happens the incoming TCP connection data can be passed to the
RDMA stack with error.

The iWARP Port Mapper solution doesn't contain any changes to the
existing network stack in the kernel space.  All the changes are
contained with the infiniband tree and also in user space.

The iWARP Port Mapper service is implemented as a user space daemon
process.  Source for the IWPM service is located at
http://git.openfabrics.org/git?p=~tnikolova/libiwpm-1.0.0/.git;a=summary

The iWARP driver (port mapper client) sends to the IWPM service the
local IP address and TCP port it has received from the RDMA
application, when starting a connection.  The IWPM service performs a
socket bind from user space to get an available TCP port, called a
mapped port, and communicates it back to the client.  In that sense,
the IWPM service is used to map the TCP port, which the RDMA
application uses to any port available from the host TCP port
space. The mapped ports are used in iWARP RDMA connections to avoid
collisions with native TCP stack which is aware that these ports are
taken. When an RDMA connection using a mapped port is terminated, the
client notifies the IWPM service, which then releases the TCP port.

The message exchange between the IWPM service and the iWARP drivers
(between user space and kernel space) is implemented using netlink
sockets.

1) Netlink interface functions are added: ibnl_unicast() and
   ibnl_mulitcast() for sending netlink messages to user space

2) The signature of the existing ibnl_put_msg() is changed to be more
   generic

3) Two netlink clients are added: RDMA_NL_NES, RDMA_NL_C4IW
   corresponding to the two iWarp drivers - nes and cxgb4 which use
   the IWPM service

4) Enums are added to enumerate the attributes in the netlink
   messages, which are exchanged between the user space IWPM service
   and the iWARP drivers

Signed-off-by: Tatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: PJ Waskiewicz <pj.waskiewicz@solidfire.com>

[ Fold in range checking fixes and nlh_next removal as suggested by Dan
  Carpenter and Steve Wise.  Fix sparse endianness in hash.  - Roland ]

Signed-off-by: Roland Dreier <roland@purestorage.com>

2 files changed, 221 insertions, 1 deletions

diff --git a/include/rdma/iw_portmap.h b/include/rdma/iw_portmap.h
new file mode 100644
index 000000000000..928b2775e992
--- /dev/null
+++ b/include/rdma/iw_portmap.h
@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2014 Intel Corporation. All rights reserved.
+ * Copyright (c) 2014 Chelsio, Inc. 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.
+ */
+#ifndef _IW_PORTMAP_H
+#define _IW_PORTMAP_H
+
+#define IWPM_ULIBNAME_SIZE	32
+#define IWPM_DEVNAME_SIZE	32
+#define IWPM_IFNAME_SIZE	16
+#define IWPM_IPADDR_SIZE	16
+
+enum {
+	IWPM_INVALID_NLMSG_ERR = 10,
+	IWPM_CREATE_MAPPING_ERR,
+	IWPM_DUPLICATE_MAPPING_ERR,
+	IWPM_UNKNOWN_MAPPING_ERR,
+	IWPM_CLIENT_DEV_INFO_ERR,
+	IWPM_USER_LIB_INFO_ERR,
+	IWPM_REMOTE_QUERY_REJECT
+};
+
+struct iwpm_dev_data {
+	char dev_name[IWPM_DEVNAME_SIZE];
+	char if_name[IWPM_IFNAME_SIZE];
+};
+
+struct iwpm_sa_data {
+	struct sockaddr_storage loc_addr;
+	struct sockaddr_storage mapped_loc_addr;
+	struct sockaddr_storage rem_addr;
+	struct sockaddr_storage mapped_rem_addr;
+};
+
+/**
+ * iwpm_init - Allocate resources for the iwarp port mapper
+ *
+ * Should be called when network interface goes up.
+ */
+int iwpm_init(u8);
+
+/**
+ * iwpm_exit - Deallocate resources for the iwarp port mapper
+ *
+ * Should be called when network interface goes down.
+ */
+int iwpm_exit(u8);
+
+/**
+ * iwpm_valid_pid - Check if the userspace iwarp port mapper pid is valid
+ *
+ * Returns true if the pid is greater than zero, otherwise returns false
+ */
+int iwpm_valid_pid(void);
+
+/**
+ * iwpm_register_pid - Send a netlink query to userspace
+ *                     to get the iwarp port mapper pid
+ * @pm_msg: Contains driver info to send to the userspace port mapper
+ * @nl_client: The index of the netlink client
+ */
+int iwpm_register_pid(struct iwpm_dev_data *pm_msg, u8 nl_client);
+
+/**
+ * iwpm_add_mapping - Send a netlink add mapping request to
+ *                    the userspace port mapper
+ * @pm_msg: Contains the local ip/tcp address info to send
+ * @nl_client: The index of the netlink client
+ *
+ * If the request is successful, the pm_msg stores
+ * the port mapper response (mapped address info)
+ */
+int iwpm_add_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client);
+
+/**
+ * iwpm_add_and_query_mapping - Send a netlink add and query mapping request
+ *				 to the userspace port mapper
+ * @pm_msg: Contains the local and remote ip/tcp address info to send
+ * @nl_client: The index of the netlink client
+ *
+ * If the request is successful, the pm_msg stores the
+ * port mapper response (mapped local and remote address info)
+ */
+int iwpm_add_and_query_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client);
+
+/**
+ * iwpm_remove_mapping - Send a netlink remove mapping request
+ *                       to the userspace port mapper
+ *
+ * @local_addr: Local ip/tcp address to remove
+ * @nl_client: The index of the netlink client
+ */
+int iwpm_remove_mapping(struct sockaddr_storage *local_addr, u8 nl_client);
+
+/**
+ * iwpm_register_pid_cb - Process the port mapper response to
+ *                        iwpm_register_pid query
+ * @skb:
+ * @cb: Contains the received message (payload and netlink header)
+ *
+ * If successful, the function receives the userspace port mapper pid
+ * which is used in future communication with the port mapper
+ */
+int iwpm_register_pid_cb(struct sk_buff *, struct netlink_callback *);
+
+/**
+ * iwpm_add_mapping_cb - Process the port mapper response to
+ *                       iwpm_add_mapping request
+ * @skb:
+ * @cb: Contains the received message (payload and netlink header)
+ */
+int iwpm_add_mapping_cb(struct sk_buff *, struct netlink_callback *);
+
+/**
+ * iwpm_add_and_query_mapping_cb - Process the port mapper response to
+ *                                 iwpm_add_and_query_mapping request
+ * @skb:
+ * @cb: Contains the received message (payload and netlink header)
+ */
+int iwpm_add_and_query_mapping_cb(struct sk_buff *, struct netlink_callback *);
+
+/**
+ * iwpm_mapping_error_cb - Process port mapper notification for error
+ *
+ * @skb:
+ * @cb: Contains the received message (payload and netlink header)
+ */
+int iwpm_mapping_error_cb(struct sk_buff *, struct netlink_callback *);
+
+/**
+ * iwpm_mapping_info_cb - Process a notification that the userspace
+ *                        port mapper daemon is started
+ * @skb:
+ * @cb: Contains the received message (payload and netlink header)
+ *
+ * Using the received port mapper pid, send all the local mapping
+ * info records to the userspace port mapper
+ */
+int iwpm_mapping_info_cb(struct sk_buff *, struct netlink_callback *);
+
+/**
+ * iwpm_ack_mapping_info_cb - Process the port mapper ack for
+ *                            the provided local mapping info records
+ * @skb:
+ * @cb: Contains the received message (payload and netlink header)
+ */
+int iwpm_ack_mapping_info_cb(struct sk_buff *, struct netlink_callback *);
+
+/**
+ * iwpm_create_mapinfo - Store local and mapped IPv4/IPv6 address
+ *                       info in a hash table
+ * @local_addr: Local ip/tcp address
+ * @mapped_addr: Mapped local ip/tcp address
+ * @nl_client: The index of the netlink client
+ */
+int iwpm_create_mapinfo(struct sockaddr_storage *local_addr,
+			struct sockaddr_storage *mapped_addr, u8 nl_client);
+
+/**
+ * iwpm_remove_mapinfo - Remove local and mapped IPv4/IPv6 address
+ *                       info from the hash table
+ * @local_addr: Local ip/tcp address
+ * @mapped_addr: Mapped local ip/tcp address
+ *
+ * Returns err code if mapping info is not found in the hash table,
+ * otherwise returns 0
+ */
+int iwpm_remove_mapinfo(struct sockaddr_storage *local_addr,
+			struct sockaddr_storage *mapped_addr);
+
+#endif /* _IW_PORTMAP_H */
diff --git a/include/rdma/rdma_netlink.h b/include/rdma/rdma_netlink.h
index e38de79eeb48..0790882e0c9b 100644
--- a/include/rdma/rdma_netlink.h
+++ b/include/rdma/rdma_netlink.h
@@ -43,7 +43,7 @@ int ibnl_remove_client(int index);
  * Returns the allocated buffer on success and NULL on failure.
  */
 void *ibnl_put_msg(struct sk_buff *skb, struct nlmsghdr **nlh, int seq,
-		   int len, int client, int op);
+		   int len, int client, int op, int flags);
 /**
  * Put a new attribute in a supplied skb.
  * @skb: The netlink skb.
@@ -56,4 +56,25 @@ void *ibnl_put_msg(struct sk_buff *skb, struct nlmsghdr **nlh, int seq,
 int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,
 		  int len, void *data, int type);
 
+/**
+ * Send the supplied skb to a specific userspace PID.
+ * @skb: The netlink skb
+ * @nlh: Header of the netlink message to send
+ * @pid: Userspace netlink process ID
+ * Returns 0 on success or a negative error code.
+ */
+int ibnl_unicast(struct sk_buff *skb, struct nlmsghdr *nlh,
+			__u32 pid);
+
+/**
+ * Send the supplied skb to a netlink group.
+ * @skb: The netlink skb
+ * @nlh: Header of the netlink message to send
+ * @group: Netlink group ID
+ * @flags: allocation flags
+ * Returns 0 on success or a negative error code.
+ */
+int ibnl_multicast(struct sk_buff *skb, struct nlmsghdr *nlh,
+			unsigned int group, gfp_t flags);
+
 #endif /* _RDMA_NETLINK_H */