tipc: move received discovery data evaluation inside node.c
The node lock is currently grabbed and and released in the function
tipc_disc_rcv() in the file discover.c. As a preparation for the next
commits, we need to move this node lock handling, along with the code
area it is covering, to node.c.
This commit introduces this change.
Tested-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>
diff --git a/net/tipc/node.c b/net/tipc/node.c
index a3ceeda..d03e88f 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -138,7 +138,7 @@
return NULL;
}
-struct tipc_node *tipc_node_create(struct net *net, u32 addr)
+struct tipc_node *tipc_node_create(struct net *net, u32 addr, u16 capabilities)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_node *n_ptr, *temp_node;
@@ -154,6 +154,7 @@
}
n_ptr->addr = addr;
n_ptr->net = net;
+ n_ptr->capabilities = capabilities;
kref_init(&n_ptr->kref);
spin_lock_init(&n_ptr->lock);
INIT_HLIST_NODE(&n_ptr->hash);
@@ -422,38 +423,118 @@
return n->active_links[0] != INVALID_BEARER_ID;
}
-void tipc_node_check_dest(struct tipc_node *n, struct tipc_bearer *b,
- bool *link_up, bool *addr_match,
- struct tipc_media_addr *maddr)
+void tipc_node_check_dest(struct net *net, u32 onode,
+ struct tipc_bearer *b,
+ u16 capabilities, u32 signature,
+ struct tipc_media_addr *maddr,
+ bool *respond, bool *dupl_addr)
{
- struct tipc_link *l = n->links[b->identity].link;
- struct tipc_media_addr *curr = &n->links[b->identity].maddr;
+ struct tipc_node *n;
+ struct tipc_link *l;
+ struct tipc_media_addr *curr_maddr;
+ struct sk_buff_head *inputq;
+ bool addr_match = false;
+ bool sign_match = false;
+ bool link_up = false;
+ bool accept_addr = false;
- *link_up = l && tipc_link_is_up(l);
- *addr_match = l && !memcmp(curr, maddr, sizeof(*maddr));
-}
+ *dupl_addr = false;
+ *respond = false;
-bool tipc_node_update_dest(struct tipc_node *n, struct tipc_bearer *b,
- struct tipc_media_addr *maddr)
-{
- struct tipc_link *l = n->links[b->identity].link;
- struct tipc_media_addr *curr = &n->links[b->identity].maddr;
- struct sk_buff_head *inputq = &n->links[b->identity].inputq;
+ n = tipc_node_create(net, onode, capabilities);
+ if (!n)
+ return;
+ tipc_node_lock(n);
+
+ curr_maddr = &n->links[b->identity].maddr;
+ inputq = &n->links[b->identity].inputq;
+
+ /* Prepare to validate requesting node's signature and media address */
+ l = n->links[b->identity].link;
+ link_up = l && tipc_link_is_up(l);
+ addr_match = l && !memcmp(curr_maddr, maddr, sizeof(*maddr));
+ sign_match = (signature == n->signature);
+
+ /* These three flags give us eight permutations: */
+
+ if (sign_match && addr_match && link_up) {
+ /* All is fine. Do nothing. */
+ } else if (sign_match && addr_match && !link_up) {
+ /* Respond. The link will come up in due time */
+ *respond = true;
+ } else if (sign_match && !addr_match && link_up) {
+ /* Peer has changed i/f address without rebooting.
+ * If so, the link will reset soon, and the next
+ * discovery will be accepted. So we can ignore it.
+ * It may also be an cloned or malicious peer having
+ * chosen the same node address and signature as an
+ * existing one.
+ * Ignore requests until the link goes down, if ever.
+ */
+ *dupl_addr = true;
+ } else if (sign_match && !addr_match && !link_up) {
+ /* Peer link has changed i/f address without rebooting.
+ * It may also be a cloned or malicious peer; we can't
+ * distinguish between the two.
+ * The signature is correct, so we must accept.
+ */
+ accept_addr = true;
+ *respond = true;
+ } else if (!sign_match && addr_match && link_up) {
+ /* Peer node rebooted. Two possibilities:
+ * - Delayed re-discovery; this link endpoint has already
+ * reset and re-established contact with the peer, before
+ * receiving a discovery message from that node.
+ * (The peer happened to receive one from this node first).
+ * - The peer came back so fast that our side has not
+ * discovered it yet. Probing from this side will soon
+ * reset the link, since there can be no working link
+ * endpoint at the peer end, and the link will re-establish.
+ * Accept the signature, since it comes from a known peer.
+ */
+ n->signature = signature;
+ } else if (!sign_match && addr_match && !link_up) {
+ /* The peer node has rebooted.
+ * Accept signature, since it is a known peer.
+ */
+ n->signature = signature;
+ *respond = true;
+ } else if (!sign_match && !addr_match && link_up) {
+ /* Peer rebooted with new address, or a new/duplicate peer.
+ * Ignore until the link goes down, if ever.
+ */
+ *dupl_addr = true;
+ } else if (!sign_match && !addr_match && !link_up) {
+ /* Peer rebooted with new address, or it is a new peer.
+ * Accept signature and address.
+ */
+ n->signature = signature;
+ accept_addr = true;
+ *respond = true;
+ }
+
+ if (!accept_addr)
+ goto exit;
+
+ /* Now create new link if not already existing */
if (!l) {
l = tipc_link_create(n, b, maddr, inputq, &n->bclink.namedq);
- if (!l)
- return false;
+ if (!l) {
+ *respond = false;
+ goto exit;
+ }
tipc_node_calculate_timer(n, l);
- if (n->link_cnt == 1) {
+ if (n->link_cnt == 1)
if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
tipc_node_get(n);
- }
}
memcpy(&l->media_addr, maddr, sizeof(*maddr));
- memcpy(curr, maddr, sizeof(*maddr));
+ memcpy(curr_maddr, maddr, sizeof(*maddr));
tipc_node_link_down(n, b->identity);
- return true;
+exit:
+ tipc_node_unlock(n);
+ tipc_node_put(n);
}
void tipc_node_delete_links(struct net *net, int bearer_id)