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linux/net/tipc/node.c

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/*
* 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"
#include "discover.h"
/* Node FSM states and events:
*/
enum {
SELF_DOWN_PEER_DOWN = 0xdd,
SELF_UP_PEER_UP = 0xaa,
SELF_DOWN_PEER_LEAVING = 0xd1,
SELF_UP_PEER_COMING = 0xac,
SELF_COMING_PEER_UP = 0xca,
SELF_LEAVING_PEER_DOWN = 0x1d,
NODE_FAILINGOVER = 0xf0,
NODE_SYNCHING = 0xcc
};
enum {
SELF_ESTABL_CONTACT_EVT = 0xece,
SELF_LOST_CONTACT_EVT = 0x1ce,
PEER_ESTABL_CONTACT_EVT = 0x9ece,
PEER_LOST_CONTACT_EVT = 0x91ce,
NODE_FAILOVER_BEGIN_EVT = 0xfbe,
NODE_FAILOVER_END_EVT = 0xfee,
NODE_SYNCH_BEGIN_EVT = 0xcbe,
NODE_SYNCH_END_EVT = 0xcee
};
static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
struct sk_buff_head *xmitq,
struct tipc_media_addr **maddr);
static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
bool delete);
static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
static void node_established_contact(struct tipc_node *n_ptr);
static void tipc_node_delete(struct tipc_node *node);
static void tipc_node_timeout(unsigned long data);
static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
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, u16 capabilities)
{
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;
n_ptr->capabilities = capabilities;
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.namedq);
__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->state = SELF_DOWN_PEER_LEAVING;
n_ptr->signature = INVALID_NODE_SIG;
n_ptr->active_links[0] = INVALID_BEARER_ID;
n_ptr->active_links[1] = INVALID_BEARER_ID;
tipc_node_get(n_ptr);
setup_timer(&n_ptr->timer, tipc_node_timeout, (unsigned long)n_ptr);
n_ptr->keepalive_intv = U32_MAX;
exit:
spin_unlock_bh(&tn->node_list_lock);
return n_ptr;
}
static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
{
unsigned long tol = l->tolerance;
unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
unsigned long keepalive_intv = msecs_to_jiffies(intv);
/* Link with lowest tolerance determines timer interval */
if (keepalive_intv < n->keepalive_intv)
n->keepalive_intv = keepalive_intv;
/* Ensure link's abort limit corresponds to current interval */
l->abort_limit = l->tolerance / jiffies_to_msecs(n->keepalive_intv);
}
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) {
if (del_timer(&node->timer))
tipc_node_put(node);
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_timeout - handle expiration of node timer
*/
static void tipc_node_timeout(unsigned long data)
{
struct tipc_node *n = (struct tipc_node *)data;
struct tipc_link_entry *le;
struct sk_buff_head xmitq;
int bearer_id;
int rc = 0;
__skb_queue_head_init(&xmitq);
for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
tipc_node_lock(n);
le = &n->links[bearer_id];
if (le->link) {
/* Link tolerance may change asynchronously: */
tipc_node_calculate_timer(n, le->link);
rc = tipc_link_timeout(le->link, &xmitq);
}
tipc_node_unlock(n);
tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
if (rc & TIPC_LINK_DOWN_EVT)
tipc_node_link_down(n, bearer_id, false);
}
if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
tipc_node_get(n);
tipc_node_put(n);
}
/**
* __tipc_node_link_up - handle addition of link
* Node lock must be held by caller
* Link becomes active (alone or shared) or standby, depending on its priority.
*/
static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
struct sk_buff_head *xmitq)
{
int *slot0 = &n->active_links[0];
int *slot1 = &n->active_links[1];
struct tipc_link *ol = node_active_link(n, 0);
struct tipc_link *nl = n->links[bearer_id].link;
if (!nl || !tipc_link_is_up(nl))
return;
if (n->working_links > 1) {
pr_warn("Attempt to establish 3rd link to %x\n", n->addr);
return;
}
n->working_links++;
n->action_flags |= TIPC_NOTIFY_LINK_UP;
n->link_id = nl->peer_bearer_id << 16 | bearer_id;
/* Leave room for tunnel header when returning 'mtu' to users: */
n->links[bearer_id].mtu = nl->mtu - INT_H_SIZE;
tipc_bearer_add_dest(n->net, bearer_id, n->addr);
pr_debug("Established link <%s> on network plane %c\n",
nl->name, nl->net_plane);
/* First link? => give it both slots */
if (!ol) {
*slot0 = bearer_id;
*slot1 = bearer_id;
tipc_link_build_bcast_sync_msg(nl, xmitq);
node_established_contact(n);
return;
}
/* Second link => redistribute slots */
if (nl->priority > ol->priority) {
pr_debug("Old link <%s> becomes standby\n", ol->name);
*slot0 = bearer_id;
*slot1 = bearer_id;
} else if (nl->priority == ol->priority) {
*slot0 = bearer_id;
} else {
pr_debug("New link <%s> is standby\n", nl->name);
}
/* Prepare synchronization with first link */
tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
}
/**
* tipc_node_link_up - handle addition of link
*
* Link becomes active (alone or shared) or standby, depending on its priority.
*/
static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
struct sk_buff_head *xmitq)
{
tipc_node_lock(n);
__tipc_node_link_up(n, bearer_id, xmitq);
tipc_node_unlock(n);
}
/**
* __tipc_node_link_down - handle loss of link
*/
static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
struct sk_buff_head *xmitq,
struct tipc_media_addr **maddr)
{
struct tipc_link_entry *le = &n->links[*bearer_id];
int *slot0 = &n->active_links[0];
int *slot1 = &n->active_links[1];
int i, highest = 0;
struct tipc_link *l, *_l, *tnl;
l = n->links[*bearer_id].link;
if (!l || tipc_link_is_reset(l))
return;
n->working_links--;
n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
n->link_id = l->peer_bearer_id << 16 | *bearer_id;
tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
pr_debug("Lost link <%s> on network plane %c\n",
l->name, l->net_plane);
/* Select new active link if any available */
*slot0 = INVALID_BEARER_ID;
*slot1 = INVALID_BEARER_ID;
for (i = 0; i < MAX_BEARERS; i++) {
_l = n->links[i].link;
if (!_l || !tipc_link_is_up(_l))
continue;
if (_l == l)
continue;
if (_l->priority < highest)
continue;
if (_l->priority > highest) {
highest = _l->priority;
*slot0 = i;
*slot1 = i;
continue;
}
*slot1 = i;
}
if (!tipc_node_is_up(n)) {
tipc_link_reset(l);
node_lost_contact(n, &le->inputq);
return;
}
/* There is still a working link => initiate failover */
tnl = node_active_link(n, 0);
n->sync_point = tnl->rcv_nxt + (U16_MAX / 2 - 1);
tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
tipc_link_reset(l);
tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
*maddr = &n->links[tnl->bearer_id].maddr;
*bearer_id = tnl->bearer_id;
}
static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
{
struct tipc_link_entry *le = &n->links[bearer_id];
struct tipc_media_addr *maddr;
struct sk_buff_head xmitq;
__skb_queue_head_init(&xmitq);
tipc_node_lock(n);
__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
if (delete && le->link) {
kfree(le->link);
le->link = NULL;
n->link_cnt--;
}
tipc_node_unlock(n);
tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
tipc_sk_rcv(n->net, &le->inputq);
}
bool tipc_node_is_up(struct tipc_node *n)
{
return n->active_links[0] != INVALID_BEARER_ID;
}
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_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;
bool reset = true;
*dupl_addr = false;
*respond = false;
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. */
reset = false;
} 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) {
*respond = false;
goto exit;
}
tipc_node_calculate_timer(n, l);
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, maddr, sizeof(*maddr));
exit:
tipc_node_unlock(n);
if (reset)
tipc_node_link_down(n, b->identity, false);
tipc_node_put(n);
}
void tipc_node_delete_links(struct net *net, int bearer_id)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_node *n;
rcu_read_lock();
list_for_each_entry_rcu(n, &tn->node_list, list) {
tipc_node_link_down(n, bearer_id, true);
}
rcu_read_unlock();
}
static void tipc_node_reset_links(struct tipc_node *n)
{
char addr_string[16];
int i;
pr_warn("Resetting all links to %s\n",
tipc_addr_string_fill(addr_string, n->addr));
for (i = 0; i < MAX_BEARERS; i++) {
tipc_node_link_down(n, i, false);
}
}
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--;
}
}
/* tipc_node_fsm_evt - node finite state machine
* Determines when contact is allowed with peer node
*/
static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
{
int state = n->state;
switch (state) {
case SELF_DOWN_PEER_DOWN:
switch (evt) {
case SELF_ESTABL_CONTACT_EVT:
state = SELF_UP_PEER_COMING;
break;
case PEER_ESTABL_CONTACT_EVT:
state = SELF_COMING_PEER_UP;
break;
case SELF_LOST_CONTACT_EVT:
case PEER_LOST_CONTACT_EVT:
break;
case NODE_SYNCH_END_EVT:
case NODE_SYNCH_BEGIN_EVT:
case NODE_FAILOVER_BEGIN_EVT:
case NODE_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
case SELF_UP_PEER_UP:
switch (evt) {
case SELF_LOST_CONTACT_EVT:
state = SELF_DOWN_PEER_LEAVING;
break;
case PEER_LOST_CONTACT_EVT:
state = SELF_LEAVING_PEER_DOWN;
break;
case NODE_SYNCH_BEGIN_EVT:
state = NODE_SYNCHING;
break;
case NODE_FAILOVER_BEGIN_EVT:
state = NODE_FAILINGOVER;
break;
case SELF_ESTABL_CONTACT_EVT:
case PEER_ESTABL_CONTACT_EVT:
case NODE_SYNCH_END_EVT:
case NODE_FAILOVER_END_EVT:
break;
default:
goto illegal_evt;
}
break;
case SELF_DOWN_PEER_LEAVING:
switch (evt) {
case PEER_LOST_CONTACT_EVT:
state = SELF_DOWN_PEER_DOWN;
break;
case SELF_ESTABL_CONTACT_EVT:
case PEER_ESTABL_CONTACT_EVT:
case SELF_LOST_CONTACT_EVT:
break;
case NODE_SYNCH_END_EVT:
case NODE_SYNCH_BEGIN_EVT:
case NODE_FAILOVER_BEGIN_EVT:
case NODE_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
case SELF_UP_PEER_COMING:
switch (evt) {
case PEER_ESTABL_CONTACT_EVT:
state = SELF_UP_PEER_UP;
break;
case SELF_LOST_CONTACT_EVT:
state = SELF_DOWN_PEER_LEAVING;
break;
case SELF_ESTABL_CONTACT_EVT:
case PEER_LOST_CONTACT_EVT:
break;
case NODE_SYNCH_END_EVT:
case NODE_SYNCH_BEGIN_EVT:
case NODE_FAILOVER_BEGIN_EVT:
case NODE_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
case SELF_COMING_PEER_UP:
switch (evt) {
case SELF_ESTABL_CONTACT_EVT:
state = SELF_UP_PEER_UP;
break;
case PEER_LOST_CONTACT_EVT:
state = SELF_LEAVING_PEER_DOWN;
break;
case SELF_LOST_CONTACT_EVT:
case PEER_ESTABL_CONTACT_EVT:
break;
case NODE_SYNCH_END_EVT:
case NODE_SYNCH_BEGIN_EVT:
case NODE_FAILOVER_BEGIN_EVT:
case NODE_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
case SELF_LEAVING_PEER_DOWN:
switch (evt) {
case SELF_LOST_CONTACT_EVT:
state = SELF_DOWN_PEER_DOWN;
break;
case SELF_ESTABL_CONTACT_EVT:
case PEER_ESTABL_CONTACT_EVT:
case PEER_LOST_CONTACT_EVT:
break;
case NODE_SYNCH_END_EVT:
case NODE_SYNCH_BEGIN_EVT:
case NODE_FAILOVER_BEGIN_EVT:
case NODE_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
case NODE_FAILINGOVER:
switch (evt) {
case SELF_LOST_CONTACT_EVT:
state = SELF_DOWN_PEER_LEAVING;
break;
case PEER_LOST_CONTACT_EVT:
state = SELF_LEAVING_PEER_DOWN;
break;
case NODE_FAILOVER_END_EVT:
state = SELF_UP_PEER_UP;
break;
case NODE_FAILOVER_BEGIN_EVT:
case SELF_ESTABL_CONTACT_EVT:
case PEER_ESTABL_CONTACT_EVT:
break;
case NODE_SYNCH_BEGIN_EVT:
case NODE_SYNCH_END_EVT:
default:
goto illegal_evt;
}
break;
case NODE_SYNCHING:
switch (evt) {
case SELF_LOST_CONTACT_EVT:
state = SELF_DOWN_PEER_LEAVING;
break;
case PEER_LOST_CONTACT_EVT:
state = SELF_LEAVING_PEER_DOWN;
break;
case NODE_SYNCH_END_EVT:
state = SELF_UP_PEER_UP;
break;
case NODE_FAILOVER_BEGIN_EVT:
state = NODE_FAILINGOVER;
break;
case NODE_SYNCH_BEGIN_EVT:
case SELF_ESTABL_CONTACT_EVT:
case PEER_ESTABL_CONTACT_EVT:
break;
case NODE_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
default:
pr_err("Unknown node fsm state %x\n", state);
break;
}
n->state = state;
return;
illegal_evt:
pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
}
bool tipc_node_filter_pkt(struct tipc_node *n, struct tipc_msg *hdr)
{
int state = n->state;
if (likely(state == SELF_UP_PEER_UP))
return true;
if (state == SELF_LEAVING_PEER_DOWN)
return false;
if (state == SELF_DOWN_PEER_LEAVING) {
if (msg_peer_node_is_up(hdr))
return false;
}
return true;
}
static void node_established_contact(struct tipc_node *n_ptr)
{
tipc_node_fsm_evt(n_ptr, SELF_ESTABL_CONTACT_EVT);
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,
struct sk_buff_head *inputq)
{
char addr_string[16];
struct tipc_sock_conn *conn, *safe;
struct tipc_link *l;
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++) {
l = n_ptr->links[i].link;
if (l)
tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
}
/* Prevent re-contact with node until cleanup is done */
tipc_node_fsm_evt(n_ptr, SELF_LOST_CONTACT_EVT);
/* 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(inputq, skb);
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;
if (likely(!flags)) {
spin_unlock_bh(&node->lock);
return;
}
addr = node->addr;
link_id = node->link_id;
publ_list = &node->publ_list;
node->action_flags &= ~(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_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_BCAST_MSG_EVT)
tipc_bclink_input(net);
if (flags & TIPC_BCAST_RESET)
tipc_node_reset_links(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;
}
static struct tipc_link *tipc_node_select_link(struct tipc_node *n, int sel,
int *bearer_id,
struct tipc_media_addr **maddr)
{
int id = n->active_links[sel & 1];
if (unlikely(id < 0))
return NULL;
*bearer_id = id;
*maddr = &n->links[id].maddr;
return n->links[id].link;
}
/**
* tipc_node_xmit() is the general link level function for message sending
* @net: the applicable net namespace
* @list: chain of buffers containing message
* @dnode: address of destination node
* @selector: a number used for deterministic link selection
* Consumes the buffer chain, except when returning -ELINKCONG
* Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
*/
int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
u32 dnode, int selector)
{
struct tipc_link *l = NULL;
struct tipc_node *n;
struct sk_buff_head xmitq;
struct tipc_media_addr *maddr;
int bearer_id;
int rc = -EHOSTUNREACH;
__skb_queue_head_init(&xmitq);
n = tipc_node_find(net, dnode);
if (likely(n)) {
tipc_node_lock(n);
l = tipc_node_select_link(n, selector, &bearer_id, &maddr);
if (likely(l))
rc = tipc_link_xmit(l, list, &xmitq);
tipc_node_unlock(n);
if (unlikely(rc == -ENOBUFS))
tipc_node_link_down(n, bearer_id, false);
tipc_node_put(n);
}
if (likely(!rc)) {
tipc_bearer_xmit(net, bearer_id, &xmitq, maddr);
return 0;
}
if (likely(in_own_node(net, dnode))) {
tipc_sk_rcv(net, list);
return 0;
}
return rc;
}
/* tipc_node_xmit_skb(): send single buffer to destination
* Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
* messages, which will not be rejected
* The only exception is datagram messages rerouted after secondary
* lookup, which are rare and safe to dispose of anyway.
* TODO: Return real return value, and let callers use
* tipc_wait_for_sendpkt() where applicable
*/
int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
u32 selector)
{
struct sk_buff_head head;
int rc;
skb_queue_head_init(&head);
__skb_queue_tail(&head, skb);
rc = tipc_node_xmit(net, &head, dnode, selector);
if (rc == -ELINKCONG)
kfree_skb(skb);
return 0;
}
/**
* tipc_node_check_state - check and if necessary update node state
* @skb: TIPC packet
* @bearer_id: identity of bearer delivering the packet
* Returns true if state is ok, otherwise consumes buffer and returns false
*/
static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
int bearer_id, struct sk_buff_head *xmitq)
{
struct tipc_msg *hdr = buf_msg(skb);
int usr = msg_user(hdr);
int mtyp = msg_type(hdr);
u16 oseqno = msg_seqno(hdr);
u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
u16 exp_pkts = msg_msgcnt(hdr);
u16 rcv_nxt, syncpt, dlv_nxt;
int state = n->state;
struct tipc_link *l, *pl = NULL;
struct tipc_media_addr *maddr;
int i, pb_id;
l = n->links[bearer_id].link;
if (!l)
return false;
rcv_nxt = l->rcv_nxt;
if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
return true;
/* Find parallel link, if any */
for (i = 0; i < MAX_BEARERS; i++) {
if ((i != bearer_id) && n->links[i].link) {
pl = n->links[i].link;
break;
}
}
/* Update node accesibility if applicable */
if (state == SELF_UP_PEER_COMING) {
if (!tipc_link_is_up(l))
return true;
if (!msg_peer_link_is_up(hdr))
return true;
tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
}
if (state == SELF_DOWN_PEER_LEAVING) {
if (msg_peer_node_is_up(hdr))
return false;
tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
}
/* Ignore duplicate packets */
if (less(oseqno, rcv_nxt))
return true;
/* Initiate or update failover mode if applicable */
if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
syncpt = oseqno + exp_pkts - 1;
if (pl && tipc_link_is_up(pl)) {
pb_id = pl->bearer_id;
__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
tipc_skb_queue_splice_tail_init(pl->inputq, l->inputq);
}
/* If pkts arrive out of order, use lowest calculated syncpt */
if (less(syncpt, n->sync_point))
n->sync_point = syncpt;
}
/* Open parallel link when tunnel link reaches synch point */
if ((n->state == NODE_FAILINGOVER) && !tipc_link_is_failingover(l)) {
if (!more(rcv_nxt, n->sync_point))
return true;
tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
if (pl)
tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
return true;
}
/* Initiate or update synch mode if applicable */
if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG)) {
syncpt = iseqno + exp_pkts - 1;
if (!tipc_link_is_up(l)) {
tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
__tipc_node_link_up(n, bearer_id, xmitq);
}
if (n->state == SELF_UP_PEER_UP) {
n->sync_point = syncpt;
tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
}
if (less(syncpt, n->sync_point))
n->sync_point = syncpt;
}
/* Open tunnel link when parallel link reaches synch point */
if ((n->state == NODE_SYNCHING) && tipc_link_is_synching(l)) {
if (pl)
dlv_nxt = mod(pl->rcv_nxt - skb_queue_len(pl->inputq));
if (!pl || more(dlv_nxt, n->sync_point)) {
tipc_link_fsm_evt(l, LINK_SYNCH_END_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
return true;
}
if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
return true;
if (usr == LINK_PROTOCOL)
return true;
return false;
}
return true;
}
/**
* tipc_rcv - process TIPC packets/messages arriving from off-node
* @net: the applicable net namespace
* @skb: TIPC packet
* @bearer: pointer to bearer message arrived on
*
* Invoked with no locks held. Bearer pointer must point to a valid bearer
* structure (i.e. cannot be NULL), but bearer can be inactive.
*/
void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
{
struct sk_buff_head xmitq;
struct tipc_node *n;
struct tipc_msg *hdr = buf_msg(skb);
int usr = msg_user(hdr);
int bearer_id = b->identity;
struct tipc_link_entry *le;
int rc = 0;
__skb_queue_head_init(&xmitq);
/* Ensure message is well-formed */
if (unlikely(!tipc_msg_validate(skb)))
goto discard;
/* Handle arrival of a non-unicast link packet */
if (unlikely(msg_non_seq(hdr))) {
if (usr == LINK_CONFIG)
tipc_disc_rcv(net, skb, b);
else
tipc_bclink_rcv(net, skb);
return;
}
/* Locate neighboring node that sent packet */
n = tipc_node_find(net, msg_prevnode(hdr));
if (unlikely(!n))
goto discard;
le = &n->links[bearer_id];
tipc_node_lock(n);
/* Is reception permitted at the moment ? */
if (!tipc_node_filter_pkt(n, hdr))
goto unlock;
if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
tipc_bclink_sync_state(n, hdr);
/* Release acked broadcast packets */
if (unlikely(n->bclink.acked != msg_bcast_ack(hdr)))
tipc_bclink_acknowledge(n, msg_bcast_ack(hdr));
/* Check and if necessary update node state */
if (likely(tipc_node_check_state(n, skb, bearer_id, &xmitq))) {
rc = tipc_link_rcv(le->link, skb, &xmitq);
skb = NULL;
}
unlock:
tipc_node_unlock(n);
if (unlikely(rc & TIPC_LINK_UP_EVT))
tipc_node_link_up(n, bearer_id, &xmitq);
if (unlikely(rc & TIPC_LINK_DOWN_EVT))
tipc_node_link_down(n, bearer_id, false);
if (unlikely(!skb_queue_empty(&n->bclink.namedq)))
tipc_named_rcv(net, &n->bclink.namedq);
if (!skb_queue_empty(&le->inputq))
tipc_sk_rcv(net, &le->inputq);
if (!skb_queue_empty(&xmitq))
tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
tipc_node_put(n);
discard:
kfree_skb(skb);
}
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;
}
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