linux/net/tipc/node.c
Jon Paul Maloy 2be80c2d87 tipc: fix stale link problem during synchronization
Recent changes to the link synchronization means that we can now just
drop packets arriving on the synchronizing link before the synch point
is reached. This has lead to significant simplifications to the
implementation, but also turns out to have a flip side that we need
to consider.

Under unlucky circumstances, the two endpoints may end up
repeatedly dropping each other's packets, while immediately
asking for retransmission of the same packets, just to drop
them once more. This pattern will eventually be broken when
the synch point is reached on the other link, but before that,
the endpoints may have arrived at the retransmission limit
(stale counter) that indicates that the link should be broken.
We see this happen at rare occasions.

The fix for this is to not ask for retransmissions when a link is in
state LINK_SYNCHING. The fact that the link has reached this state
means that it has already received the first SYNCH packet, and that it
knows the synch point. Hence, it doesn't need any more packets until the
other link has reached the synch point, whereafter it can go ahead and
ask for the missing packets.

However, because of the reduced traffic on the synching link that
follows this change, it may now take longer to discover that the
synch point has been reached. We compensate for this by letting all
packets, on any of the links, trig a check for synchronization
termination. This is possible because the packets themselves don't
contain any information that is needed for discovering this condition.

Reviewed-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>
2015-08-23 16:14:45 -07:00

1332 lines
34 KiB
C

/*
* 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;
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);
tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
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_link_entry *le;
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);
le = &n->links[b->identity];
/* Prepare to validate requesting node's signature and media address */
l = le->link;
link_up = l && tipc_link_is_up(l);
addr_match = l && !memcmp(&le->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) {
if (n->link_cnt == 2) {
pr_warn("Cannot establish 3rd link to %x\n", n->addr);
goto exit;
}
if (!tipc_link_create(n, b, mod(tipc_net(net)->random),
tipc_own_addr(net), onode, &le->maddr,
&le->inputq, &n->bclink.namedq, &l)) {
*respond = false;
goto exit;
}
tipc_link_reset(l);
if (n->state == NODE_FAILINGOVER)
tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
le->link = l;
n->link_cnt++;
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(&le->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);
}
}
/* 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, *tnl, *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_up(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;
}
/* No synching needed if only one link */
if (!pl || !tipc_link_is_up(pl))
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 (tipc_link_is_synching(l)) {
tnl = l;
} else {
tnl = pl;
pl = l;
}
dlv_nxt = pl->rcv_nxt - mod(skb_queue_len(pl->inputq));
if (more(dlv_nxt, n->sync_point)) {
tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
return true;
}
if (l == pl)
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;
}