tipc: add ioctl to fetch link names

We add a new ioctl for AF_TIPC that can be used to fetch the
logical name for a link to a remote node on a given bearer. This
should be used in combination with link state subscriptions.
The logical name size limit definitions are moved to tipc.h, as
they are now also needed by the new ioctl.

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

1 files changed, 26 insertions, 3 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 3c0256962f7d..3f9912f87d0d 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -36,6 +36,7 @@
 
 #include "core.h"
 #include "port.h"
+#include "node.h"
 
 #include <linux/export.h>
 
@@ -1905,6 +1906,28 @@ static int tipc_getsockopt(struct socket *sock, int lvl, int opt,
         return put_user(sizeof(value), ol);
 }
 
+int tipc_ioctl(struct socket *sk, unsigned int cmd, unsigned long arg)
+{
+        struct tipc_sioc_ln_req lnr;
+        void __user *argp = (void __user *)arg;
+
+        switch (cmd) {
+        case SIOCGETLINKNAME:
+                if (copy_from_user(&lnr, argp, sizeof(lnr)))
+                        return -EFAULT;
+                if (!tipc_node_get_linkname(lnr.bearer_id, lnr.peer,
+                                            lnr.linkname, TIPC_MAX_LINK_NAME)) {
+                        if (copy_to_user(argp, &lnr, sizeof(lnr)))
+                                return -EFAULT;
+                        return 0;
+                }
+                return -EADDRNOTAVAIL;
+                break;
+        default:
+                return -ENOIOCTLCMD;
+        }
+}
+
 /* Protocol switches for the various types of TIPC sockets */
 
 static const struct proto_ops msg_ops = {
@@ -1917,7 +1940,7 @@ static const struct proto_ops msg_ops = {
         .accept         = sock_no_accept,
         .getname        = tipc_getname,
         .poll           = tipc_poll,
-        .ioctl          = sock_no_ioctl,
+        .ioctl          = tipc_ioctl,
         .listen         = sock_no_listen,
         .shutdown       = tipc_shutdown,
         .setsockopt     = tipc_setsockopt,
@@ -1938,7 +1961,7 @@ static const struct proto_ops packet_ops = {
         .accept         = tipc_accept,
         .getname        = tipc_getname,
         .poll           = tipc_poll,
-        .ioctl          = sock_no_ioctl,
+        .ioctl          = tipc_ioctl,
         .listen         = tipc_listen,
         .shutdown       = tipc_shutdown,
         .setsockopt     = tipc_setsockopt,
@@ -1959,7 +1982,7 @@ static const struct proto_ops stream_ops = {
         .accept         = tipc_accept,
         .getname        = tipc_getname,
         .poll           = tipc_poll,
-        .ioctl          = sock_no_ioctl,
+        .ioctl          = tipc_ioctl,
         .listen         = tipc_listen,
         .shutdown       = tipc_shutdown,
         .setsockopt     = tipc_setsockopt,