tipc: refactor function tipc_sk_anc_data_recv()

We refactor tipc_sk_anc_data_recv() to make it slightly more
comprehensible, but also to facilitate application of some additions
to the code in a future commit.

Reviewed-by: Xin Long <lucien.xin@gmail.com>
Tested-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index cb2d9ff..c635fd2 100644 (file)
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1733,67 +1733,58 @@ static void tipc_sk_set_orig_addr(struct msghdr *m, struct sk_buff *skb)
 static int tipc_sk_anc_data_recv(struct msghdr *m, struct sk_buff *skb,
                                 struct tipc_sock *tsk)
 {
-       struct tipc_msg *msg;
-       u32 anc_data[3];
-       u32 err;
-       u32 dest_type;
-       int has_name;
-       int res;
+       struct tipc_msg *hdr;
+       u32 data[3] = {0,};
+       bool has_addr;
+       int dlen, rc;
 
        if (likely(m->msg_controllen == 0))
                return 0;
-       msg = buf_msg(skb);
 
-       /* Optionally capture errored message object(s) */
-       err = msg ? msg_errcode(msg) : 0;
-       if (unlikely(err)) {
-               anc_data[0] = err;
-               anc_data[1] = msg_data_sz(msg);
-               res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data);
-               if (res)
-                       return res;
-               if (anc_data[1]) {
-                       if (skb_linearize(skb))
-                               return -ENOMEM;
-                       msg = buf_msg(skb);
-                       res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1],
-                                      msg_data(msg));
-                       if (res)
-                               return res;
-               }
+       hdr = buf_msg(skb);
+       dlen = msg_data_sz(hdr);
+
+       /* Capture errored message object, if any */
+       if (msg_errcode(hdr)) {
+               if (skb_linearize(skb))
+                       return -ENOMEM;
+               hdr = buf_msg(skb);
+               data[0] = msg_errcode(hdr);
+               data[1] = dlen;
+               rc = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, data);
+               if (rc || !dlen)
+                       return rc;
+               rc = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, dlen, msg_data(hdr));
+               if (rc)
+                       return rc;
        }
 
-       /* Optionally capture message destination object */
-       dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG;
-       switch (dest_type) {
+       /* Capture TIPC_SERVICE_ADDR/RANGE destination address, if any */
+       switch (msg_type(hdr)) {
        case TIPC_NAMED_MSG:
-               has_name = 1;
-               anc_data[0] = msg_nametype(msg);
-               anc_data[1] = msg_namelower(msg);
-               anc_data[2] = msg_namelower(msg);
+               has_addr = true;
+               data[0] = msg_nametype(hdr);
+               data[1] = msg_namelower(hdr);
+               data[2] = data[1];
                break;
        case TIPC_MCAST_MSG:
-               has_name = 1;
-               anc_data[0] = msg_nametype(msg);
-               anc_data[1] = msg_namelower(msg);
-               anc_data[2] = msg_nameupper(msg);
+               has_addr = true;
+               data[0] = msg_nametype(hdr);
+               data[1] = msg_namelower(hdr);
+               data[2] = msg_nameupper(hdr);
                break;
        case TIPC_CONN_MSG:
-               has_name = !!tsk->conn_addrtype;
-               anc_data[0] = msg_nametype(&tsk->phdr);
-               anc_data[1] = msg_nameinst(&tsk->phdr);
-               anc_data[2] = anc_data[1];
+               has_addr = !!tsk->conn_addrtype;
+               data[0] = msg_nametype(&tsk->phdr);
+               data[1] = msg_nameinst(&tsk->phdr);
+               data[2] = data[1];
                break;
        default:
-               has_name = 0;
-       }
-       if (has_name) {
-               res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data);
-               if (res)
-                       return res;
+               has_addr = false;
        }
-
-       return 0;
+       if (!has_addr)
+               return 0;
+       return put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, data);
 }
 
 static struct sk_buff *tipc_sk_build_ack(struct tipc_sock *tsk)