tipc: introduce ioctl for fetching node identity

After the introduction of a 128-bit node identity it may be difficult
for a user to correlate between this identity and the generated node
hash address.

We now try to make this easier by introducing a new ioctl() call for
fetching a node identity by using the hash value as key. This will
be particularly useful when we extend some of the commands in the
'tipc' tool, but we also expect regular user applications to need
this feature.

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

3 files changed, 33 insertions, 2 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index e9c52e1416c5..81e6dd0cd1ca 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -195,6 +195,27 @@ int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel)
         return mtu;
 }
 
+bool tipc_node_get_id(struct net *net, u32 addr, u8 *id)
+{
+        u8 *own_id = tipc_own_id(net);
+        struct tipc_node *n;
+
+        if (!own_id)
+                return true;
+
+        if (addr == tipc_own_addr(net)) {
+                memcpy(id, own_id, TIPC_NODEID_LEN);
+                return true;
+        }
+        n = tipc_node_find(net, addr);
+        if (!n)
+                return false;
+
+        memcpy(id, &n->peer_id, TIPC_NODEID_LEN);
+        tipc_node_put(n);
+        return true;
+}
+
 u16 tipc_node_get_capabilities(struct net *net, u32 addr)
 {
         struct tipc_node *n;
diff --git a/net/tipc/node.h b/net/tipc/node.h
index bb271a37c93f..846c8f240872 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -60,6 +60,7 @@ enum {
 #define INVALID_BEARER_ID -1
 
 void tipc_node_stop(struct net *net);
+bool tipc_node_get_id(struct net *net, u32 addr, u8 *id);
 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr);
 void tipc_node_check_dest(struct net *net, u32 onode, u8 *peer_id128,
                           struct tipc_bearer *bearer,
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 252a52ae0893..c4992002fd68 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2973,7 +2973,8 @@ static int tipc_getsockopt(struct socket *sock, int lvl, int opt,
 
 static int tipc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 {
-        struct sock *sk = sock->sk;
+        struct net *net = sock_net(sock->sk);
+        struct tipc_sioc_nodeid_req nr = {0};
         struct tipc_sioc_ln_req lnr;
         void __user *argp = (void __user *)arg;
 
@@ -2981,7 +2982,7 @@ static int tipc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
         case SIOCGETLINKNAME:
                 if (copy_from_user(&lnr, argp, sizeof(lnr)))
                         return -EFAULT;
-                if (!tipc_node_get_linkname(sock_net(sk),
+                if (!tipc_node_get_linkname(net,
                                             lnr.bearer_id & 0xffff, lnr.peer,
                                             lnr.linkname, TIPC_MAX_LINK_NAME)) {
                         if (copy_to_user(argp, &lnr, sizeof(lnr)))
@@ -2989,6 +2990,14 @@ static int tipc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
                         return 0;
                 }
                 return -EADDRNOTAVAIL;
+        case SIOCGETNODEID:
+                if (copy_from_user(&nr, argp, sizeof(nr)))
+                        return -EFAULT;
+                if (!tipc_node_get_id(net, nr.peer, nr.node_id))
+                        return -EADDRNOTAVAIL;
+                if (copy_to_user(argp, &nr, sizeof(nr)))
+                        return -EFAULT;
+                return 0;
         default:
                 return -ENOIOCTLCMD;
         }