net: rose: restore old recvmsg behavior

[ Upstream commit f81152e35001e91997ec74a7b4e040e6ab0acccf ]

recvmsg handler in net/rose/af_rose.c performs size-check ->msg_namelen.

After commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c
(net: rework recvmsg handler msg_name and msg_namelen logic), we now
always take the else branch due to namelen being initialized to 0.

Digging in netdev-vger-cvs git repo shows that msg_namelen was
initialized with a fixed-size since at least 1995, so the else branch
was never taken.

Compile tested only.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 12 deletions

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index abf0ad6311d0..27e6896705e6 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1253,6 +1253,7 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,
 
         if (msg->msg_name) {
                 struct sockaddr_rose *srose;
+                struct full_sockaddr_rose *full_srose = msg->msg_name;
 
                 memset(msg->msg_name, 0, sizeof(struct full_sockaddr_rose));
                 srose = msg->msg_name;
@@ -1260,18 +1261,9 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,
                 srose->srose_addr   = rose->dest_addr;
                 srose->srose_call   = rose->dest_call;
                 srose->srose_ndigis = rose->dest_ndigis;
-                if (msg->msg_namelen >= sizeof(struct full_sockaddr_rose)) {
-                        struct full_sockaddr_rose *full_srose = (struct full_sockaddr_rose *)msg->msg_name;
-                        for (n = 0 ; n < rose->dest_ndigis ; n++)
-                                full_srose->srose_digis[n] = rose->dest_digis[n];
-                        msg->msg_namelen = sizeof(struct full_sockaddr_rose);
-                } else {
-                        if (rose->dest_ndigis >= 1) {
-                                srose->srose_ndigis = 1;
-                                srose->srose_digi = rose->dest_digis[0];
-                        }
-                        msg->msg_namelen = sizeof(struct sockaddr_rose);
-                }
+                for (n = 0 ; n < rose->dest_ndigis ; n++)
+                        full_srose->srose_digis[n] = rose->dest_digis[n];
+                msg->msg_namelen = sizeof(struct full_sockaddr_rose);
         }
 
         skb_free_datagram(sk, skb);