tipc: add bearer disable/enable to new netlink api

A new netlink API for tipc that can disable or enable a tipc bearer.

The new API is separated from the old API because of a bug in the
user space client (tipc-config). The problem is that older versions
of tipc-config has a very low receive limit and adding commands to
the legacy genl_opts struct causes the ctrl_getfamily() response
message to grow, subsequently breaking the tool.

The new API utilizes netlink policies for input validation. Where the
top-level netlink attributes are tipc-logical entities, like bearer.
The top level entities then contain nested attributes. In this case
a name, nested link properties and a domain.

Netlink commands implemented in this patch:
TIPC_NL_BEARER_ENABLE
TIPC_NL_BEARER_DISABLE

Netlink logical layout of bearer enable message:
-> bearer
    -> name
    [ -> domain ]
    [
    -> properties
        -> priority
    ]

Netlink logical layout of bearer disable message:
-> bearer
    -> name

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

8 files changed, 320 insertions, 3 deletions

diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h
new file mode 100644
index 000000000000..b9b710faa229
--- /dev/null
+++ b/include/uapi/linux/tipc_netlink.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2014, Ericsson AB
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _LINUX_TIPC_NETLINK_H_
+#define _LINUX_TIPC_NETLINK_H_
+
+#define TIPC_GENL_V2_NAME      "TIPCv2"
+#define TIPC_GENL_V2_VERSION   0x1
+
+/* Netlink commands */
+enum {
+        TIPC_NL_UNSPEC,
+        TIPC_NL_LEGACY,
+        TIPC_NL_BEARER_DISABLE,
+        TIPC_NL_BEARER_ENABLE,
+
+        __TIPC_NL_CMD_MAX,
+        TIPC_NL_CMD_MAX = __TIPC_NL_CMD_MAX - 1
+};
+
+/* Top level netlink attributes */
+enum {
+        TIPC_NLA_UNSPEC,
+        TIPC_NLA_BEARER,                /* nest */
+
+        __TIPC_NLA_MAX,
+        TIPC_NLA_MAX = __TIPC_NLA_MAX - 1
+};
+
+/* Bearer info */
+enum {
+        TIPC_NLA_BEARER_UNSPEC,
+        TIPC_NLA_BEARER_NAME,           /* string */
+        TIPC_NLA_BEARER_PROP,           /* nest */
+        TIPC_NLA_BEARER_DOMAIN,         /* u32 */
+
+        __TIPC_NLA_BEARER_MAX,
+        TIPC_NLA_BEARER_MAX = __TIPC_NLA_BEARER_MAX - 1
+};
+
+/* Nest, link propreties. Valid for link, media and bearer */
+enum {
+        TIPC_NLA_PROP_UNSPEC,
+
+        TIPC_NLA_PROP_PRIO,             /* u32 */
+        TIPC_NLA_PROP_TOL,              /* u32 */
+        TIPC_NLA_PROP_WIN,              /* u32 */
+
+        __TIPC_NLA_PROP_MAX,
+        TIPC_NLA_PROP_MAX = __TIPC_NLA_PROP_MAX - 1
+};
+
+#endif
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 264474394f9f..59815be0ab98 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/bearer.c: TIPC bearer code
  *
- * Copyright (c) 1996-2006, 2013, Ericsson AB
+ * Copyright (c) 1996-2006, 2013-2014, Ericsson AB
  * Copyright (c) 2004-2006, 2010-2013, Wind River Systems
  * All rights reserved.
  *
@@ -37,6 +37,7 @@
 #include "core.h"
 #include "config.h"
 #include "bearer.h"
+#include "link.h"
 #include "discover.h"
 
 #define MAX_ADDR_STR 60
@@ -49,6 +50,17 @@ static struct tipc_media * const media_info_array[] = {
         NULL
 };
 
+static const struct nla_policy
+tipc_nl_bearer_policy[TIPC_NLA_BEARER_MAX + 1]  = {
+        [TIPC_NLA_BEARER_UNSPEC]                = { .type = NLA_UNSPEC },
+        [TIPC_NLA_BEARER_NAME] = {
+                .type = NLA_STRING,
+                .len = TIPC_MAX_BEARER_NAME
+        },
+        [TIPC_NLA_BEARER_PROP]                  = { .type = NLA_NESTED },
+        [TIPC_NLA_BEARER_DOMAIN]                = { .type = NLA_U32 }
+};
+
 struct tipc_bearer __rcu *bearer_list[MAX_BEARERS + 1];
 
 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down);
@@ -627,3 +639,88 @@ void tipc_bearer_stop(void)
                 }
         }
 }
+
+int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
+{
+        int err;
+        char *name;
+        struct tipc_bearer *bearer;
+        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+
+        if (!info->attrs[TIPC_NLA_BEARER])
+                return -EINVAL;
+
+        err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
+                               info->attrs[TIPC_NLA_BEARER],
+                               tipc_nl_bearer_policy);
+        if (err)
+                return err;
+
+        if (!attrs[TIPC_NLA_BEARER_NAME])
+                return -EINVAL;
+
+        name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+        rtnl_lock();
+        bearer = tipc_bearer_find(name);
+        if (!bearer) {
+                rtnl_unlock();
+                return -EINVAL;
+        }
+
+        bearer_disable(bearer, false);
+        rtnl_unlock();
+
+        return 0;
+}
+
+int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
+{
+        int err;
+        char *bearer;
+        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+        u32 domain;
+        u32 prio;
+
+        prio = TIPC_MEDIA_LINK_PRI;
+        domain = tipc_own_addr & TIPC_CLUSTER_MASK;
+
+        if (!info->attrs[TIPC_NLA_BEARER])
+                return -EINVAL;
+
+        err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
+                               info->attrs[TIPC_NLA_BEARER],
+                               tipc_nl_bearer_policy);
+        if (err)
+                return err;
+
+        if (!attrs[TIPC_NLA_BEARER_NAME])
+                return -EINVAL;
+
+        bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+        if (attrs[TIPC_NLA_BEARER_DOMAIN])
+                domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
+
+        if (attrs[TIPC_NLA_BEARER_PROP]) {
+                struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
+
+                err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
+                                              props);
+                if (err)
+                        return err;
+
+                if (props[TIPC_NLA_PROP_PRIO])
+                        prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
+        }
+
+        rtnl_lock();
+        err = tipc_enable_bearer(bearer, domain, prio);
+        if (err) {
+                rtnl_unlock();
+                return err;
+        }
+        rtnl_unlock();
+
+        return 0;
+}
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index 78fccc49de23..a87e8c78d862 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -1,7 +1,7 @@
 /*
  * net/tipc/bearer.h: Include file for TIPC bearer code
  *
- * Copyright (c) 1996-2006, 2013, Ericsson AB
+ * Copyright (c) 1996-2006, 2013-2014, Ericsson AB
  * Copyright (c) 2005, 2010-2011, Wind River Systems
  * All rights reserved.
  *
@@ -38,6 +38,8 @@
 #define _TIPC_BEARER_H
 
 #include "bcast.h"
+#include "netlink.h"
+#include <net/genetlink.h>
 
 #define MAX_BEARERS     2
 #define MAX_MEDIA       2
@@ -176,6 +178,9 @@ extern struct tipc_media eth_media_info;
 extern struct tipc_media ib_media_info;
 #endif
 
+int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info);
+int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info);
+
 int tipc_media_set_priority(const char *name, u32 new_value);
 int tipc_media_set_window(const char *name, u32 new_value);
 void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a);
diff --git a/net/tipc/core.h b/net/tipc/core.h
index f773b148722f..b578b10feefa 100644
--- a/net/tipc/core.h
+++ b/net/tipc/core.h
@@ -41,6 +41,7 @@
 
 #include <linux/tipc.h>
 #include <linux/tipc_config.h>
+#include <linux/tipc_netlink.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 7cf8004577f1..e7f365012bd1 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -40,6 +40,7 @@
 #include "name_distr.h"
 #include "discover.h"
 #include "config.h"
+#include "netlink.h"
 
 #include <linux/pkt_sched.h>
 
@@ -50,6 +51,14 @@ static const char *link_co_err = "Link changeover error, ";
 static const char *link_rst_msg = "Resetting link ";
 static const char *link_unk_evt = "Unknown link event ";
 
+/* Properties valid for media, bearar and link */
+static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
+        [TIPC_NLA_PROP_UNSPEC]          = { .type = NLA_UNSPEC },
+        [TIPC_NLA_PROP_PRIO]            = { .type = NLA_U32 },
+        [TIPC_NLA_PROP_TOL]             = { .type = NLA_U32 },
+        [TIPC_NLA_PROP_WIN]             = { .type = NLA_U32 }
+};
+
 /*
  * Out-of-range value for link session numbers
  */
@@ -2376,3 +2385,41 @@ static void link_print(struct tipc_link *l_ptr, const char *str)
         else
                 pr_cont("\n");
 }
+
+/* Parse and validate nested (link) properties valid for media, bearer and link
+ */
+int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
+{
+        int err;
+
+        err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
+                               tipc_nl_prop_policy);
+        if (err)
+                return err;
+
+        if (props[TIPC_NLA_PROP_PRIO]) {
+                u32 prio;
+
+                prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
+                if (prio > TIPC_MAX_LINK_PRI)
+                        return -EINVAL;
+        }
+
+        if (props[TIPC_NLA_PROP_TOL]) {
+                u32 tol;
+
+                tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
+                if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
+                        return -EINVAL;
+        }
+
+        if (props[TIPC_NLA_PROP_WIN]) {
+                u32 win;
+
+                win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
+                if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
+                        return -EINVAL;
+        }
+
+        return 0;
+}
diff --git a/net/tipc/link.h b/net/tipc/link.h
index b567a3427fda..4338294f20d4 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -37,6 +37,7 @@
 #ifndef _TIPC_LINK_H
 #define _TIPC_LINK_H
 
+#include <net/genetlink.h>
 #include "msg.h"
 #include "node.h"
 
@@ -239,6 +240,8 @@ void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
 void tipc_link_retransmit(struct tipc_link *l_ptr,
                           struct sk_buff *start, u32 retransmits);
 
+int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
+
 /*
  * Link sequence number manipulation routines (uses modulo 2**16 arithmetic)
  */
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index ad844d365340..af506ae0a129 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/netlink.c: TIPC configuration handling
  *
- * Copyright (c) 2005-2006, Ericsson AB
+ * Copyright (c) 2005-2006, 2014, Ericsson AB
  * Copyright (c) 2005-2007, Wind River Systems
  * All rights reserved.
  *
@@ -36,6 +36,7 @@
 
 #include "core.h"
 #include "config.h"
+#include "bearer.h"
 #include <net/genetlink.h>
 
 static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
@@ -68,6 +69,12 @@ static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
         return 0;
 }
 
+static const struct nla_policy tipc_nl_policy[TIPC_NLA_MAX + 1] = {
+        [TIPC_NLA_UNSPEC]       = { .type = NLA_UNSPEC, },
+        [TIPC_NLA_BEARER]       = { .type = NLA_NESTED, },
+};
+
+/* Legacy ASCII API */
 static struct genl_family tipc_genl_family = {
         .id             = GENL_ID_GENERATE,
         .name           = TIPC_GENL_NAME,
@@ -76,6 +83,7 @@ static struct genl_family tipc_genl_family = {
         .maxattr        = 0,
 };
 
+/* Legacy ASCII API */
 static struct genl_ops tipc_genl_ops[] = {
         {
                 .cmd            = TIPC_GENL_CMD,
@@ -83,12 +91,43 @@ static struct genl_ops tipc_genl_ops[] = {
         },
 };
 
+/* Users of the legacy API (tipc-config) can't handle that we add operations,
+ * so we have a separate genl handling for the new API.
+ */
+struct genl_family tipc_genl_v2_family = {
+        .id             = GENL_ID_GENERATE,
+        .name           = TIPC_GENL_V2_NAME,
+        .version        = TIPC_GENL_V2_VERSION,
+        .hdrsize        = 0,
+        .maxattr        = TIPC_NLA_MAX,
+};
+
+static const struct genl_ops tipc_genl_v2_ops[] = {
+        {
+                .cmd    = TIPC_NL_BEARER_DISABLE,
+                .doit   = tipc_nl_bearer_disable,
+                .policy = tipc_nl_policy,
+        },
+        {
+                .cmd    = TIPC_NL_BEARER_ENABLE,
+                .doit   = tipc_nl_bearer_enable,
+                .policy = tipc_nl_policy,
+        }
+};
+
 int tipc_netlink_start(void)
 {
         int res;
 
         res = genl_register_family_with_ops(&tipc_genl_family, tipc_genl_ops);
         if (res) {
+                pr_err("Failed to register legacy interface\n");
+                return res;
+        }
+
+        res = genl_register_family_with_ops(&tipc_genl_v2_family,
+                                            tipc_genl_v2_ops);
+        if (res) {
                 pr_err("Failed to register netlink interface\n");
                 return res;
         }
@@ -98,4 +137,5 @@ int tipc_netlink_start(void)
 void tipc_netlink_stop(void)
 {
         genl_unregister_family(&tipc_genl_family);
+        genl_unregister_family(&tipc_genl_v2_family);
 }
diff --git a/net/tipc/netlink.h b/net/tipc/netlink.h
new file mode 100644
index 000000000000..e9980c0e2207
--- /dev/null
+++ b/net/tipc/netlink.h
@@ -0,0 +1,41 @@
+/*
+ * net/tipc/netlink.h: Include file for TIPC netlink code
+ *
+ * Copyright (c) 2014, Ericsson AB
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _TIPC_NETLINK_H
+#define _TIPC_NETLINK_H
+
+extern struct genl_family tipc_genl_v2_family;
+
+#endif