tipc: modify socket iterator for sock_diag

The current socket iterator function tipc_nl_sk_dump, handles socket
locks and calls __tipc_nl_add_sk for each socket.
To reuse this logic in sock_diag implementation, we do minor
modifications to make these functions generic as described below.

In this commit, we add a two new functions __tipc_nl_sk_walk,
__tipc_nl_add_sk_info and modify tipc_nl_sk_dump, __tipc_nl_add_sk
accordingly.

In __tipc_nl_sk_walk we:
1. acquire and release socket locks
2. for each socket, execute the specified callback function

In __tipc_nl_add_sk we:
- Move the netlink attribute insertion to __tipc_nl_add_sk_info.

tipc_nl_sk_dump calls tipc_nl_sk_walk with __tipc_nl_add_sk as argument.

sock_diag will use these generic functions in a later commit.

There is no functional change in this commit.
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 41 insertions, 24 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index a4a9148d4629..35ac0f5b9529 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3160,16 +3160,33 @@ msg_full:
         return -EMSGSIZE;
 }
 
+static int __tipc_nl_add_sk_info(struct sk_buff *skb, struct tipc_sock
+                          *tsk)
+{
+        struct net *net = sock_net(skb->sk);
+        struct tipc_net *tn = tipc_net(net);
+        struct sock *sk = &tsk->sk;
+
+        if (nla_put_u32(skb, TIPC_NLA_SOCK_REF, tsk->portid) ||
+            nla_put_u32(skb, TIPC_NLA_SOCK_ADDR, tn->own_addr))
+                return -EMSGSIZE;
+
+        if (tipc_sk_connected(sk)) {
+                if (__tipc_nl_add_sk_con(skb, tsk))
+                        return -EMSGSIZE;
+        } else if (!list_empty(&tsk->publications)) {
+                if (nla_put_flag(skb, TIPC_NLA_SOCK_HAS_PUBL))
+                        return -EMSGSIZE;
+        }
+        return 0;
+}
+
 /* Caller should hold socket lock for the passed tipc socket. */
 static int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
                             struct tipc_sock *tsk)
 {
-        int err;
-        void *hdr;
         struct nlattr *attrs;
-        struct net *net = sock_net(skb->sk);
-        struct tipc_net *tn = net_generic(net, tipc_net_id);
-        struct sock *sk = &tsk->sk;
+        void *hdr;
 
         hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
                           &tipc_genl_family, NLM_F_MULTI, TIPC_NL_SOCK_GET);
@@ -3179,19 +3196,10 @@ static int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
         attrs = nla_nest_start(skb, TIPC_NLA_SOCK);
         if (!attrs)
                 goto genlmsg_cancel;
-        if (nla_put_u32(skb, TIPC_NLA_SOCK_REF, tsk->portid))
-                goto attr_msg_cancel;
-        if (nla_put_u32(skb, TIPC_NLA_SOCK_ADDR, tn->own_addr))
+
+        if (__tipc_nl_add_sk_info(skb, tsk))
                 goto attr_msg_cancel;
 
-        if (tipc_sk_connected(sk)) {
-                err = __tipc_nl_add_sk_con(skb, tsk);
-                if (err)
-                        goto attr_msg_cancel;
-        } else if (!list_empty(&tsk->publications)) {
-                if (nla_put_flag(skb, TIPC_NLA_SOCK_HAS_PUBL))
-                        goto attr_msg_cancel;
-        }
         nla_nest_end(skb, attrs);
         genlmsg_end(skb, hdr);
 
@@ -3205,16 +3213,19 @@ msg_cancel:
         return -EMSGSIZE;
 }
 
-int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
+static int __tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
+                             int (*skb_handler)(struct sk_buff *skb,
+                                                struct netlink_callback *cb,
+                                                struct tipc_sock *tsk))
 {
-        int err;
-        struct tipc_sock *tsk;
-        const struct bucket_table *tbl;
-        struct rhash_head *pos;
         struct net *net = sock_net(skb->sk);
-        struct tipc_net *tn = net_generic(net, tipc_net_id);
-        u32 tbl_id = cb->args[0];
+        struct tipc_net *tn = tipc_net(net);
+        const struct bucket_table *tbl;
         u32 prev_portid = cb->args[1];
+        u32 tbl_id = cb->args[0];
+        struct rhash_head *pos;
+        struct tipc_sock *tsk;
+        int err;
 
         rcu_read_lock();
         tbl = rht_dereference_rcu((&tn->sk_rht)->tbl, &tn->sk_rht);
@@ -3226,12 +3237,13 @@ int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
                                 continue;
                         }
 
-                        err = __tipc_nl_add_sk(skb, cb, tsk);
+                        err = skb_handler(skb, cb, tsk);
                         if (err) {
                                 prev_portid = tsk->portid;
                                 spin_unlock_bh(&tsk->sk.sk_lock.slock);
                                 goto out;
                         }
+
                         prev_portid = 0;
                         spin_unlock_bh(&tsk->sk.sk_lock.slock);
                 }
@@ -3244,6 +3256,11 @@ out:
         return skb->len;
 }
 
+int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        return __tipc_nl_sk_walk(skb, cb, __tipc_nl_add_sk);
+}
+
 /* Caller should hold socket lock for the passed tipc socket. */
 static int __tipc_nl_add_sk_publ(struct sk_buff *skb,
                                  struct netlink_callback *cb,