tipc: obtain node identity from interface by default

Selecting and explicitly configuring a TIPC node identity may be
unwanted in some cases.

In this commit we introduce a default setting if the identity has not
been set at the moment the first bearer is enabled. We do this by
using a raw copy of a unique identifier from the used interface: MAC
address in the case of an L2 bearer, IPv4/IPv6 address in the case
of a UDP bearer.

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, 29 insertions, 9 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index ae5b44ca1c1e..f7d47c89d658 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -243,12 +243,6 @@ static int tipc_enable_bearer(struct net *net, const char *name,
         int res = -EINVAL;
         char *errstr = "";
 
-        if (!tipc_own_id(net)) {
-                errstr = "not supported in standalone mode";
-                res = -ENOPROTOOPT;
-                goto rejected;
-        }
-
         if (!bearer_name_validate(name, &b_names)) {
                 errstr = "illegal name";
                 goto rejected;
@@ -381,11 +375,13 @@ static void bearer_disable(struct net *net, struct tipc_bearer *b)
 int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
                          struct nlattr *attr[])
 {
+        char *dev_name = strchr((const char *)b->name, ':') + 1;
+        int hwaddr_len = b->media->hwaddr_len;
+        u8 node_id[NODE_ID_LEN] = {0,};
         struct net_device *dev;
-        char *driver_name = strchr((const char *)b->name, ':') + 1;
 
         /* Find device with specified name */
-        dev = dev_get_by_name(net, driver_name);
+        dev = dev_get_by_name(net, dev_name);
         if (!dev)
                 return -ENODEV;
         if (tipc_mtu_bad(dev, 0)) {
@@ -393,6 +389,16 @@ int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
                 return -EINVAL;
         }
 
+        /* Autoconfigure own node identity if needed */
+        if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
+                memcpy(node_id, dev->dev_addr, hwaddr_len);
+                tipc_net_init(net, node_id, 0);
+        }
+        if (!tipc_own_id(net)) {
+                pr_warn("Failed to obtain node identity\n");
+                return -EINVAL;
+        }
+
         /* Associate TIPC bearer with L2 bearer */
         rcu_assign_pointer(b->media_ptr, dev);
         b->pt.dev = dev;
@@ -400,7 +406,7 @@ int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
         b->pt.func = tipc_l2_rcv_msg;
         dev_add_pack(&b->pt);
         memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
-        memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
+        memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
         b->bcast_addr.media_id = b->media->type_id;
         b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
         b->mtu = dev->mtu;
diff --git a/net/tipc/net.h b/net/tipc/net.h
index 08efa6010022..09ad02b50bb1 100644
--- a/net/tipc/net.h
+++ b/net/tipc/net.h
@@ -41,6 +41,7 @@
 
 extern const struct nla_policy tipc_nl_net_policy[];
 
+int tipc_net_init(struct net *net, u8 *node_id, u32 addr);
 void tipc_net_finalize(struct net *net, u32 addr);
 void tipc_net_stop(struct net *net);
 int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb);
diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 3deabcab4882..2c13b18426d9 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -47,6 +47,8 @@
 #include <net/addrconf.h>
 #include <linux/tipc_netlink.h>
 #include "core.h"
+#include "addr.h"
+#include "net.h"
 #include "bearer.h"
 #include "netlink.h"
 #include "msg.h"
@@ -647,6 +649,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
         struct udp_port_cfg udp_conf = {0};
         struct udp_tunnel_sock_cfg tuncfg = {NULL};
         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
+        u8 node_id[NODE_ID_LEN] = {0,};
 
         ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
         if (!ub)
@@ -677,6 +680,16 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
         if (err)
                 goto err;
 
+        /* Autoconfigure own node identity if needed */
+        if (!tipc_own_id(net)) {
+                memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
+                tipc_net_init(net, node_id, 0);
+        }
+        if (!tipc_own_id(net)) {
+                pr_warn("Failed to set node id, please configure manually\n");
+                return -EINVAL;
+        }
+
         b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
         b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
         rcu_assign_pointer(b->media_ptr, ub);