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>

1 files changed, 41 insertions, 1 deletions

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);
 }