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>

1 files changed, 238 insertions, 0 deletions

diff --git a/drivers/infiniband/core/iwpm_util.h b/drivers/infiniband/core/iwpm_util.h
new file mode 100644
index 000000000000..9777c869a140
--- /dev/null
+++ b/drivers/infiniband/core/iwpm_util.h
@@ -0,0 +1,238 @@
+/*
+ * 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 _IWPM_UTIL_H
+#define _IWPM_UTIL_H
+
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/spinlock.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/mutex.h>
+#include <linux/jhash.h>
+#include <linux/kref.h>
+#include <net/netlink.h>
+#include <linux/errno.h>
+#include <rdma/iw_portmap.h>
+#include <rdma/rdma_netlink.h>
+
+
+#define IWPM_NL_RETRANS		3
+#define IWPM_NL_TIMEOUT		(10*HZ)
+#define IWPM_MAPINFO_SKB_COUNT	20
+
+#define IWPM_PID_UNDEFINED     -1
+#define IWPM_PID_UNAVAILABLE   -2
+
+struct iwpm_nlmsg_request {
+	struct list_head    inprocess_list;
+	__u32               nlmsg_seq;
+	void                *req_buffer;
+	u8	            nl_client;
+	u8                  request_done;
+	u16                 err_code;
+	wait_queue_head_t   waitq;
+	struct kref         kref;
+};
+
+struct iwpm_mapping_info {
+	struct hlist_node hlist_node;
+	struct sockaddr_storage local_sockaddr;
+	struct sockaddr_storage mapped_sockaddr;
+	u8     nl_client;
+};
+
+struct iwpm_admin_data {
+	atomic_t refcount;
+	atomic_t nlmsg_seq;
+	int      client_list[RDMA_NL_NUM_CLIENTS];
+	int      reg_list[RDMA_NL_NUM_CLIENTS];
+};
+
+/**
+ * iwpm_get_nlmsg_request - Allocate and initialize netlink message request
+ * @nlmsg_seq: Sequence number of the netlink message
+ * @nl_client: The index of the netlink client
+ * @gfp: Indicates how the memory for the request should be allocated
+ *
+ * Returns the newly allocated netlink request object if successful,
+ * otherwise returns NULL
+ */
+struct iwpm_nlmsg_request *iwpm_get_nlmsg_request(__u32 nlmsg_seq,
+						u8 nl_client, gfp_t gfp);
+
+/**
+ * iwpm_free_nlmsg_request - Deallocate netlink message request
+ * @kref: Holds reference of netlink message request
+ */
+void iwpm_free_nlmsg_request(struct kref *kref);
+
+/**
+ * iwpm_find_nlmsg_request - Find netlink message request in the request list
+ * @echo_seq: Sequence number of the netlink request to find
+ *
+ * Returns the found netlink message request,
+ * if not found, returns NULL
+ */
+struct iwpm_nlmsg_request *iwpm_find_nlmsg_request(__u32 echo_seq);
+
+/**
+ * iwpm_wait_complete_req - Block while servicing the netlink request
+ * @nlmsg_request: Netlink message request to service
+ *
+ * Wakes up, after the request is completed or expired
+ * Returns 0 if the request is complete without error
+ */
+int iwpm_wait_complete_req(struct iwpm_nlmsg_request *nlmsg_request);
+
+/**
+ * iwpm_get_nlmsg_seq - Get the sequence number for a netlink
+ *			message to send to the port mapper
+ *
+ * Returns the sequence number for the netlink message.
+ */
+int iwpm_get_nlmsg_seq(void);
+
+/**
+ * iwpm_valid_client - Check if the port mapper client is valid
+ * @nl_client: The index of the netlink client
+ *
+ * Valid clients need to call iwpm_init() before using
+ * the port mapper
+ */
+int iwpm_valid_client(u8 nl_client);
+
+/**
+ * iwpm_set_valid - Set the port mapper client to valid or not
+ * @nl_client: The index of the netlink client
+ * @valid: 1 if valid or 0 if invalid
+ */
+void iwpm_set_valid(u8 nl_client, int valid);
+
+/**
+ * iwpm_registered_client - Check if the port mapper client is registered
+ * @nl_client: The index of the netlink client
+ *
+ * Call iwpm_register_pid() to register a client
+ */
+int iwpm_registered_client(u8 nl_client);
+
+/**
+ * iwpm_set_registered - Set the port mapper client to registered or not
+ * @nl_client: The index of the netlink client
+ * @reg: 1 if registered or 0 if not
+ */
+void iwpm_set_registered(u8 nl_client, int reg);
+
+/**
+ * iwpm_send_mapinfo - Send local and mapped IPv4/IPv6 address info of
+ *                     a client to the user space port mapper
+ * @nl_client: The index of the netlink client
+ * @iwpm_pid: The pid of the user space port mapper
+ *
+ * If successful, returns the number of sent mapping info records
+ */
+int iwpm_send_mapinfo(u8 nl_client, int iwpm_pid);
+
+/**
+ * iwpm_mapinfo_available - Check if any mapping info records is available
+ *		            in the hash table
+ *
+ * Returns 1 if mapping information is available, otherwise returns 0
+ */
+int iwpm_mapinfo_available(void);
+
+/**
+ * iwpm_compare_sockaddr - Compare two sockaddr storage structs
+ *
+ * Returns 0 if they are holding the same ip/tcp address info,
+ * otherwise returns 1
+ */
+int iwpm_compare_sockaddr(struct sockaddr_storage *a_sockaddr,
+			struct sockaddr_storage *b_sockaddr);
+
+/**
+ * iwpm_validate_nlmsg_attr - Check for NULL netlink attributes
+ * @nltb: Holds address of each netlink message attributes
+ * @nla_count: Number of netlink message attributes
+ *
+ * Returns error if any of the nla_count attributes is NULL
+ */
+static inline int iwpm_validate_nlmsg_attr(struct nlattr *nltb[],
+					   int nla_count)
+{
+	int i;
+	for (i = 1; i < nla_count; i++) {
+		if (!nltb[i])
+			return -EINVAL;
+	}
+	return 0;
+}
+
+/**
+ * iwpm_create_nlmsg - Allocate skb and form a netlink message
+ * @nl_op: Netlink message opcode
+ * @nlh: Holds address of the netlink message header in skb
+ * @nl_client: The index of the netlink client
+ *
+ * Returns the newly allcated skb, or NULL if the tailroom of the skb
+ * is insufficient to store the message header and payload
+ */
+struct sk_buff *iwpm_create_nlmsg(u32 nl_op, struct nlmsghdr **nlh,
+					int nl_client);
+
+/**
+ * iwpm_parse_nlmsg - Validate and parse the received netlink message
+ * @cb: Netlink callback structure
+ * @policy_max: Maximum attribute type to be expected
+ * @nlmsg_policy: Validation policy
+ * @nltb: Array to store policy_max parsed elements
+ * @msg_type: Type of netlink message
+ *
+ * Returns 0 on success or a negative error code
+ */
+int iwpm_parse_nlmsg(struct netlink_callback *cb, int policy_max,
+				const struct nla_policy *nlmsg_policy,
+				struct nlattr *nltb[], const char *msg_type);
+
+/**
+ * iwpm_print_sockaddr - Print IPv4/IPv6 address and TCP port
+ * @sockaddr: Socket address to print
+ * @msg: Message to print
+ */
+void iwpm_print_sockaddr(struct sockaddr_storage *sockaddr, char *msg);
+#endif