[PATCH V3 1/6] IB Netlink Infrastructure

Nir Muchtar
2010-12-13T16:22:45Z

The basic IB netlink infrastructure.
It allows for registration of IB clients for which data is to be exported.
It supplies message construction callbacks.

Signed-off-by: Nir Muchtar <nirm-smomgflXvOZWk0Htik3J/w@public.gmane.org>
---
drivers/infiniband/core/netlink.c | 179 +++++++++++++++++++++++++++++++++++++
include/linux/netlink.h | 1 +
include/rdma/ib_netlink.h | 59 ++++++++++++
3 files changed, 239 insertions(+), 0 deletions(-)
create mode 100644 drivers/infiniband/core/netlink.c
create mode 100644 include/rdma/ib_netlink.h

diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c
new file mode 100644
index 0000000..c004f90
--- /dev/null
+++ b/drivers/infiniband/core/netlink.c
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2010 Voltaire 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.
+ */
+
+#define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__
+
+#include <linux/netlink.h>
+
+#include <net/netlink.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <rdma/ib_netlink.h>
+
+struct ibnl_client {
+ struct list_head list;
+ int index;
+ int nops;
+ int (**cb_table)(struct sk_buff *skb,
+ struct netlink_callback *nlcb);
+};
+
+static DEFINE_MUTEX(ibnl_mutex);
+static struct sock *nls;
+static LIST_HEAD(client_list);
+
+int ibnl_add_client(int index, int nops,
+ int (*cb_table[])(struct sk_buff *skb,
+ struct netlink_callback *nlcb))
+{
+ struct ibnl_client *cur;
+ struct ibnl_client *nl_client = kmalloc(sizeof *nl_client, GFP_ATOMIC);
+
+ if (!nl_client)
+ return -ENOMEM;
+ nl_client->index = index;
+ nl_client->nops = nops;
+ nl_client->cb_table = cb_table;
+ mutex_lock(&ibnl_mutex);
+ list_for_each_entry(cur, &client_list, list) {
+ if (cur->index == index) {
+ pr_warn("Client for %d already exists\n", index);
+ mutex_unlock(&ibnl_mutex);
+ kfree(nl_client);
+ return -EINVAL;
+ }
+ }
+ list_add_tail(&nl_client->list, &client_list);
+ mutex_unlock(&ibnl_mutex);
+ return 0;
+}
+EXPORT_SYMBOL(ibnl_add_client);
+
+int ibnl_remove_client(int index)
+{
+ struct ibnl_client *cur, *next;
+
+ mutex_lock(&ibnl_mutex);
+ list_for_each_entry_safe(cur, next, &client_list, list) {
+ if (cur->index == index) {
+ list_del(&(cur->list));
+ mutex_unlock(&ibnl_mutex);
+ kfree(cur);
+ return 0;
+ }
+ }
+ pr_warn("Can't remove callback for client idx %d. Not found\n", index);
+ mutex_unlock(&ibnl_mutex);
+ return -EINVAL;
+}
+EXPORT_SYMBOL(ibnl_remove_client);
+
+void *ibnl_put_msg(struct sk_buff *skb, struct nlmsghdr **nlh, int seq,
+ int len, int client, int op)
+{
+ unsigned char *prev_tail;
+
+ prev_tail = skb_tail_pointer(skb);
+ *nlh = NLMSG_NEW(skb, 0, seq, IBNL_GET_TYPE(client, op),
+ len, NLM_F_MULTI);
+ (*nlh)->nlmsg_len = skb_tail_pointer(skb) - prev_tail;
+ return NLMSG_DATA(*nlh);
+nlmsg_failure:
+ nlmsg_trim(skb, prev_tail);
+ return NULL;
+}
+EXPORT_SYMBOL(ibnl_put_msg);
+
+int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,
+ int len, void *data, int type)
+{
+ unsigned char *prev_tail;
+
+ prev_tail = skb_tail_pointer(skb);
+ NLA_PUT(skb, type, len, data);
+ nlh->nlmsg_len += skb_tail_pointer(skb) - prev_tail;
+ return 0;
+nla_put_failure:
+ nlmsg_trim(skb, prev_tail - nlh->nlmsg_len);
+ return -EMSGSIZE;
+}
+EXPORT_SYMBOL(ibnl_put_attr);
+
+static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ struct ibnl_client *client;
+ int type = nlh->nlmsg_type;
+ int index = IBNL_GET_CLIENT(type);
+ int op = IBNL_GET_OP(type);
+ list_for_each_entry(client, &client_list, list) {
+ if (client->index == index) {
+ if (op < 0 || op >= client->nops ||
+ !client->cb_table[IBNL_GET_OP(op)])
+ return -EINVAL;
+ return netlink_dump_start(nls, skb, nlh,
+ client->cb_table[op], NULL);
+ }
+ }
+ pr_info("Index %d wasn't found in client list\n", index);
+ return -EINVAL;
+}
+
+static void ibnl_rcv(struct sk_buff *skb)
+{
+ mutex_lock(&ibnl_mutex);
+ netlink_rcv_skb(skb, &ibnl_rcv_msg);
+ mutex_unlock(&ibnl_mutex);
+}
+
+int ibnl_init(void)
+{
+ nls = netlink_kernel_create(&init_net, NETLINK_INFINIBAND, 0, ibnl_rcv,
+ NULL, THIS_MODULE);
+ if (!nls) {
+ pr_warn("Failed to create netlink socket\n");
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+void ibnl_cleanup(void)
+{
+ struct ibnl_client *cur, *next;
+
+ mutex_lock(&ibnl_mutex);
+ list_for_each_entry_safe(cur, next, &client_list, list) {
+ list_del(&(cur->list));
+ kfree(cur);
+ }
+ mutex_unlock(&ibnl_mutex);
+ netlink_kernel_release(nls);
+}
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 1235669..c9693f9 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -24,6 +24,7 @@
/* leave room for NETLINK_DM (DM Events) */
#define NETLINK_SCSITRANSPORT 18 /* SCSI Transports */
#define NETLINK_ECRYPTFS 19
+#define NETLINK_INFINIBAND 20

#define MAX_LINKS 32

diff --git a/include/rdma/ib_netlink.h b/include/rdma/ib_netlink.h
new file mode 100644
index 0000000..0db338c
--- /dev/null
+++ b/include/rdma/ib_netlink.h
@@ -0,0 +1,59 @@
+#ifndef _IBNETLINK_H
+#define _IBNETLINK_H
+
+#define IBNL_GET_CLIENT(type) ((type & (((1 << 6) - 1) << 10)) >> 10)
+#define IBNL_GET_OP(type) (type & ((1 << 10) - 1))
+#define IBNL_GET_TYPE(client, op) ((client << 10) + op)
+
+#ifdef __KERNEL__
+
+int ibnl_init(void);
+void ibnl_cleanup(void);
+
+/**
+ * Add a a client to the list of IB netlink exporters.
+ * @index: Index of the added client
+ * @nops: Number of supported ops by the added client.
+ * @cb_table: A table for op->callback
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int ibnl_add_client(int index, int nops,
+ int (*cb_table[])(struct sk_buff *skb,
+ struct netlink_callback *nlcb));
+
+/**
+ * Remove a client from IB netlink.
+ * @index: Index of the removed IB client.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int ibnl_remove_client(int index);
+
+/**
+ * Put a new message in a supplied skb.
+ * @skb: The netlink skb.
+ * @nlh: Pointer to put the header of the new netlink message.
+ * @seq: The message sequence number.
+ * @len: The requested message length to allocate.
+ * @client: Calling IB netlink client.
+ * @op: message content op.
+ * 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);
+/**
+ * Put a new attribute in a supplied skb.
+ * @skb: The netlink skb.
+ * @nlh: Header of the netlink message to append the attribute to.
+ * @len: The length of the attribute data.
+ * @data: The attribute data to put.
+ * @type: The attribute type.
+ * Returns the 0 and a negative error code on failure.
+ */
+int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,
+ int len, void *data, int type);
+
+#endif /* __KERNEL__ */
+
+#endif /* _IBNETLINK_H */
--
1.7.1