diff options
Diffstat (limited to 'net/tipc/node.c')
-rw-r--r-- | net/tipc/node.c | 123 |
1 files changed, 102 insertions, 21 deletions
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 @@ struct tipc_node *tipc_node_find(struct net *net, u32 addr) 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 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr) } 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 @@ bool tipc_node_is_up(struct tipc_node *n) 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; + + *dupl_addr = false; + *respond = false; + + n = tipc_node_create(net, onode, capabilities); + if (!n) + return; - *link_up = l && tipc_link_is_up(l); - *addr_match = l && !memcmp(curr, maddr, sizeof(*maddr)); -} + tipc_node_lock(n); -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; + 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) |