/* * net/tipc/node.c: TIPC node management routines * * Copyright (c) 2000-2006, 2012-2015, Ericsson AB * Copyright (c) 2005-2006, 2010-2014, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "core.h" #include "link.h" #include "node.h" #include "name_distr.h" #include "socket.h" #include "bcast.h" static void node_lost_contact(struct tipc_node *n_ptr); static void node_established_contact(struct tipc_node *n_ptr); static void tipc_node_delete(struct tipc_node *node); struct tipc_sock_conn { u32 port; u32 peer_port; u32 peer_node; struct list_head list; }; static const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = { [TIPC_NLA_NODE_UNSPEC] = { .type = NLA_UNSPEC }, [TIPC_NLA_NODE_ADDR] = { .type = NLA_U32 }, [TIPC_NLA_NODE_UP] = { .type = NLA_FLAG } }; /* * A trivial power-of-two bitmask technique is used for speed, since this * operation is done for every incoming TIPC packet. The number of hash table * entries has been chosen so that no hash chain exceeds 8 nodes and will * usually be much smaller (typically only a single node). */ static unsigned int tipc_hashfn(u32 addr) { return addr & (NODE_HTABLE_SIZE - 1); } static void tipc_node_kref_release(struct kref *kref) { struct tipc_node *node = container_of(kref, struct tipc_node, kref); tipc_node_delete(node); } void tipc_node_put(struct tipc_node *node) { kref_put(&node->kref, tipc_node_kref_release); } static void tipc_node_get(struct tipc_node *node) { kref_get(&node->kref); } /* * tipc_node_find - locate specified node object, if it exists */ struct tipc_node *tipc_node_find(struct net *net, u32 addr) { struct tipc_net *tn = net_generic(net, tipc_net_id); struct tipc_node *node; if (unlikely(!in_own_cluster_exact(net, addr))) return NULL; rcu_read_lock(); hlist_for_each_entry_rcu(node, &tn->node_htable[tipc_hashfn(addr)], hash) { if (node->addr == addr) { tipc_node_get(node); rcu_read_unlock(); return node; } } rcu_read_unlock(); return NULL; } struct tipc_node *tipc_node_create(struct net *net, u32 addr) { struct tipc_net *tn = net_generic(net, tipc_net_id); struct tipc_node *n_ptr, *temp_node; spin_lock_bh(&tn->node_list_lock); n_ptr = tipc_node_find(net, addr); if (n_ptr) goto exit; n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC); if (!n_ptr) { pr_warn("Node creation failed, no memory\n"); goto exit; } n_ptr->addr = addr; n_ptr->net = net; kref_init(&n_ptr->kref); spin_lock_init(&n_ptr->lock); INIT_HLIST_NODE(&n_ptr->hash); INIT_LIST_HEAD(&n_ptr->list); INIT_LIST_HEAD(&n_ptr->publ_list); INIT_LIST_HEAD(&n_ptr->conn_sks); __skb_queue_head_init(&n_ptr->bclink.deferdq); hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]); list_for_each_entry_rcu(temp_node, &tn->node_list, list) { if (n_ptr->addr < temp_node->addr) break; } list_add_tail_rcu(&n_ptr->list, &temp_node->list); n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN; n_ptr->signature = INVALID_NODE_SIG; tipc_node_get(n_ptr); exit: spin_unlock_bh(&tn->node_list_lock); return n_ptr; } static void tipc_node_delete(struct tipc_node *node) { list_del_rcu(&node->list); hlist_del_rcu(&node->hash); kfree_rcu(node, rcu); } void tipc_node_stop(struct net *net) { struct tipc_net *tn = net_generic(net, tipc_net_id); struct tipc_node *node, *t_node; spin_lock_bh(&tn->node_list_lock); list_for_each_entry_safe(node, t_node, &tn->node_list, list) tipc_node_put(node); spin_unlock_bh(&tn->node_list_lock); } int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port) { struct tipc_node *node; struct tipc_sock_conn *conn; int err = 0; if (in_own_node(net, dnode)) return 0; node = tipc_node_find(net, dnode); if (!node) { pr_warn("Connecting sock to node 0x%x failed\n", dnode); return -EHOSTUNREACH; } conn = kmalloc(sizeof(*conn), GFP_ATOMIC); if (!conn) { err = -EHOSTUNREACH; goto exit; } conn->peer_node = dnode; conn->port = port; conn->peer_port = peer_port; tipc_node_lock(node); list_add_tail(&conn->list, &node->conn_sks); tipc_node_unlock(node); exit: tipc_node_put(node); return err; } void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port) { struct tipc_node *node; struct tipc_sock_conn *conn, *safe; if (in_own_node(net, dnode)) return; node = tipc_node_find(net, dnode); if (!node) return; tipc_node_lock(node); list_for_each_entry_safe(conn, safe, &node->conn_sks, list) { if (port != conn->port) continue; list_del(&conn->list); kfree(conn); } tipc_node_unlock(node); tipc_node_put(node); } /** * tipc_node_link_up - handle addition of link * * Link becomes active (alone or shared) or standby, depending on its priority. */ void tipc_node_link_up(struct tipc_node *n, int bearer_id) { struct tipc_link_entry **actv = &n->active_links[0]; struct tipc_link_entry *le = &n->links[bearer_id]; struct tipc_link *l = le->link; /* Leave room for tunnel header when returning 'mtu' to users: */ n->links[bearer_id].mtu = l->mtu - INT_H_SIZE; n->working_links++; n->action_flags |= TIPC_NOTIFY_LINK_UP; n->link_id = l->peer_bearer_id << 16 | l->bearer_id; pr_debug("Established link <%s> on network plane %c\n", l->name, l->net_plane); /* No active links ? => take both active slots */ if (!actv[0]) { actv[0] = le; actv[1] = le; node_established_contact(n); return; } if (l->priority < actv[0]->link->priority) { pr_debug("New link <%s> becomes standby\n", l->name); return; } tipc_link_dup_queue_xmit(actv[0]->link, l); /* Take one active slot if applicable */ if (l->priority == actv[0]->link->priority) { actv[0] = le; return; } /* Higher prio than current active? => take both active slots */ pr_debug("Old l <%s> becomes standby\n", actv[0]->link->name); if (actv[1] != actv[0]) pr_debug("Old link <%s> now standby\n", actv[1]->link->name); actv[0] = le; actv[1] = le; } /** * node_select_active_links - select which working links should be active */ static void node_select_active_links(struct tipc_node *n) { struct tipc_link_entry **actv = &n->active_links[0]; struct tipc_link *l; u32 b, highest = 0; actv[0] = NULL; actv[1] = NULL; for (b = 0; b < MAX_BEARERS; b++) { l = n->links[b].link; if (!l || !tipc_link_is_up(l) || (l->priority < highest)) continue; if (l->priority > highest) { highest = l->priority; actv[0] = &n->links[b]; actv[1] = &n->links[b]; continue; } actv[1] = &n->links[b]; } } /** * tipc_node_link_down - handle loss of link */ void tipc_node_link_down(struct tipc_node *n, int bearer_id) { struct tipc_link_entry **actv = &n->active_links[0]; struct tipc_link_entry *le = &n->links[bearer_id]; struct tipc_link *l = le->link; n->working_links--; n->action_flags |= TIPC_NOTIFY_LINK_DOWN; n->link_id = l->peer_bearer_id << 16 | l->bearer_id; if (!tipc_link_is_active(l)) { pr_debug("Lost standby link <%s> on network plane %c\n", l->name, l->net_plane); return; } pr_debug("Lost link <%s> on network plane %c\n", l->name, l->net_plane); /* Resdistribute active slots if applicable */ if (actv[0] == le) actv[0] = actv[1]; if (actv[1] == le) actv[1] = actv[0]; /* Last link of this priority? => select other ones if available */ if (actv[0] == le) node_select_active_links(n); if (tipc_node_is_up(n)) tipc_link_failover_send_queue(l); else node_lost_contact(n); } bool tipc_node_is_up(struct tipc_node *n) { return n->active_links[0]; } void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) { n_ptr->links[l_ptr->bearer_id].link = l_ptr; n_ptr->link_cnt++; } void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) { int i; for (i = 0; i < MAX_BEARERS; i++) { if (l_ptr != n_ptr->links[i].link) continue; n_ptr->links[i].link = NULL; n_ptr->link_cnt--; } } static void node_established_contact(struct tipc_node *n_ptr) { n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP; n_ptr->bclink.oos_state = 0; n_ptr->bclink.acked = tipc_bclink_get_last_sent(n_ptr->net); tipc_bclink_add_node(n_ptr->net, n_ptr->addr); } static void node_lost_contact(struct tipc_node *n_ptr) { char addr_string[16]; struct tipc_sock_conn *conn, *safe; struct list_head *conns = &n_ptr->conn_sks; struct sk_buff *skb; struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id); uint i; pr_debug("Lost contact with %s\n", tipc_addr_string_fill(addr_string, n_ptr->addr)); /* Flush broadcast link info associated with lost node */ if (n_ptr->bclink.recv_permitted) { __skb_queue_purge(&n_ptr->bclink.deferdq); if (n_ptr->bclink.reasm_buf) { kfree_skb(n_ptr->bclink.reasm_buf); n_ptr->bclink.reasm_buf = NULL; } tipc_bclink_remove_node(n_ptr->net, n_ptr->addr); tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ); n_ptr->bclink.recv_permitted = false; } /* Abort any ongoing link failover */ for (i = 0; i < MAX_BEARERS; i++) { struct tipc_link *l_ptr = n_ptr->links[i].link; if (!l_ptr) continue; l_ptr->flags &= ~LINK_FAILINGOVER; l_ptr->failover_checkpt = 0; l_ptr->failover_pkts = 0; kfree_skb(l_ptr->failover_skb); l_ptr->failover_skb = NULL; tipc_link_reset_fragments(l_ptr); } n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN; /* Prevent re-contact with node until cleanup is done */ n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN; /* Notify publications from this node */ n_ptr->action_flags |= TIPC_NOTIFY_NODE_DOWN; /* Notify sockets connected to node */ list_for_each_entry_safe(conn, safe, conns, list) { skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG, SHORT_H_SIZE, 0, tn->own_addr, conn->peer_node, conn->port, conn->peer_port, TIPC_ERR_NO_NODE); if (likely(skb)) { skb_queue_tail(n_ptr->inputq, skb); n_ptr->action_flags |= TIPC_MSG_EVT; } list_del(&conn->list); kfree(conn); } } /** * tipc_node_get_linkname - get the name of a link * * @bearer_id: id of the bearer * @node: peer node address * @linkname: link name output buffer * * Returns 0 on success */ int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr, char *linkname, size_t len) { struct tipc_link *link; int err = -EINVAL; struct tipc_node *node = tipc_node_find(net, addr); if (!node) return err; if (bearer_id >= MAX_BEARERS) goto exit; tipc_node_lock(node); link = node->links[bearer_id].link; if (link) { strncpy(linkname, link->name, len); err = 0; } exit: tipc_node_unlock(node); tipc_node_put(node); return err; } void tipc_node_unlock(struct tipc_node *node) { struct net *net = node->net; u32 addr = 0; u32 flags = node->action_flags; u32 link_id = 0; struct list_head *publ_list; struct sk_buff_head *inputq = node->inputq; struct sk_buff_head *namedq; if (likely(!flags || (flags == TIPC_MSG_EVT))) { node->action_flags = 0; spin_unlock_bh(&node->lock); if (flags == TIPC_MSG_EVT) tipc_sk_rcv(net, inputq); return; } addr = node->addr; link_id = node->link_id; namedq = node->namedq; publ_list = &node->publ_list; node->action_flags &= ~(TIPC_MSG_EVT | TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP | TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP | TIPC_WAKEUP_BCAST_USERS | TIPC_BCAST_MSG_EVT | TIPC_NAMED_MSG_EVT | TIPC_BCAST_RESET); spin_unlock_bh(&node->lock); if (flags & TIPC_NOTIFY_NODE_DOWN) tipc_publ_notify(net, publ_list, addr); if (flags & TIPC_WAKEUP_BCAST_USERS) tipc_bclink_wakeup_users(net); if (flags & TIPC_NOTIFY_NODE_UP) tipc_named_node_up(net, addr); if (flags & TIPC_NOTIFY_LINK_UP) tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr, TIPC_NODE_SCOPE, link_id, addr); if (flags & TIPC_NOTIFY_LINK_DOWN) tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr, link_id, addr); if (flags & TIPC_MSG_EVT) tipc_sk_rcv(net, inputq); if (flags & TIPC_NAMED_MSG_EVT) tipc_named_rcv(net, namedq); if (flags & TIPC_BCAST_MSG_EVT) tipc_bclink_input(net); if (flags & TIPC_BCAST_RESET) tipc_link_reset_all(node); } /* Caller should hold node lock for the passed node */ static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node) { void *hdr; struct nlattr *attrs; hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, NLM_F_MULTI, TIPC_NL_NODE_GET); if (!hdr) return -EMSGSIZE; attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE); if (!attrs) goto msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr)) goto attr_msg_full; if (tipc_node_is_up(node)) if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP)) goto attr_msg_full; nla_nest_end(msg->skb, attrs); genlmsg_end(msg->skb, hdr); return 0; attr_msg_full: nla_nest_cancel(msg->skb, attrs); msg_full: genlmsg_cancel(msg->skb, hdr); return -EMSGSIZE; } int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb) { int err; struct net *net = sock_net(skb->sk); struct tipc_net *tn = net_generic(net, tipc_net_id); int done = cb->args[0]; int last_addr = cb->args[1]; struct tipc_node *node; struct tipc_nl_msg msg; if (done) return 0; msg.skb = skb; msg.portid = NETLINK_CB(cb->skb).portid; msg.seq = cb->nlh->nlmsg_seq; rcu_read_lock(); if (last_addr) { node = tipc_node_find(net, last_addr); if (!node) { rcu_read_unlock(); /* We never set seq or call nl_dump_check_consistent() * this means that setting prev_seq here will cause the * consistence check to fail in the netlink callback * handler. Resulting in the NLMSG_DONE message having * the NLM_F_DUMP_INTR flag set if the node state * changed while we released the lock. */ cb->prev_seq = 1; return -EPIPE; } tipc_node_put(node); } list_for_each_entry_rcu(node, &tn->node_list, list) { if (last_addr) { if (node->addr == last_addr) last_addr = 0; else continue; } tipc_node_lock(node); err = __tipc_nl_add_node(&msg, node); if (err) { last_addr = node->addr; tipc_node_unlock(node); goto out; } tipc_node_unlock(node); } done = 1; out: cb->args[0] = done; cb->args[1] = last_addr; rcu_read_unlock(); return skb->len; }