linux/net/tipc/node.c
Jon Paul Maloy e7142c341c tipc: eliminate risk of double link_up events
When an ACTIVATE or data packet is received in a link in state
ESTABLISHING, the link does not immediately change state to
ESTABLISHED, but does instead return a LINK_UP event to the caller,
which will execute the state change in a different lock context.

This non-atomic approach incurs a low risk that we may have two
LINK_UP events pending simultaneously for the same link, resulting
in the final part of the setup procedure being executed twice. The
only potential harm caused by this it that we may see two LINK_UP
events issued to subsribers of the topology server, something that
may cause confusion.

This commit eliminates this risk by checking if the link is already
up before proceeding with the second half of the setup.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-12 17:11:27 -04:00

1924 lines
48 KiB
C

/*
* net/tipc/node.c: TIPC node management routines
*
* Copyright (c) 2000-2006, 2012-2016, 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"
#include "netlink.h"
#define INVALID_NODE_SIG 0x10000
/* Flags used to take different actions according to flag type
* TIPC_NOTIFY_NODE_DOWN: notify node is down
* TIPC_NOTIFY_NODE_UP: notify node is up
* TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
*/
enum {
TIPC_NOTIFY_NODE_DOWN = (1 << 3),
TIPC_NOTIFY_NODE_UP = (1 << 4),
TIPC_NOTIFY_LINK_UP = (1 << 6),
TIPC_NOTIFY_LINK_DOWN = (1 << 7)
};
struct tipc_link_entry {
struct tipc_link *link;
spinlock_t lock; /* per link */
u32 mtu;
struct sk_buff_head inputq;
struct tipc_media_addr maddr;
};
struct tipc_bclink_entry {
struct tipc_link *link;
struct sk_buff_head inputq1;
struct sk_buff_head arrvq;
struct sk_buff_head inputq2;
struct sk_buff_head namedq;
};
/**
* struct tipc_node - TIPC node structure
* @addr: network address of node
* @ref: reference counter to node object
* @lock: rwlock governing access to structure
* @net: the applicable net namespace
* @hash: links to adjacent nodes in unsorted hash chain
* @inputq: pointer to input queue containing messages for msg event
* @namedq: pointer to name table input queue with name table messages
* @active_links: bearer ids of active links, used as index into links[] array
* @links: array containing references to all links to node
* @action_flags: bit mask of different types of node actions
* @state: connectivity state vs peer node
* @sync_point: sequence number where synch/failover is finished
* @list: links to adjacent nodes in sorted list of cluster's nodes
* @working_links: number of working links to node (both active and standby)
* @link_cnt: number of links to node
* @capabilities: bitmap, indicating peer node's functional capabilities
* @signature: node instance identifier
* @link_id: local and remote bearer ids of changing link, if any
* @publ_list: list of publications
* @rcu: rcu struct for tipc_node
*/
struct tipc_node {
u32 addr;
struct kref kref;
rwlock_t lock;
struct net *net;
struct hlist_node hash;
int active_links[2];
struct tipc_link_entry links[MAX_BEARERS];
struct tipc_bclink_entry bc_entry;
int action_flags;
struct list_head list;
int state;
u16 sync_point;
int link_cnt;
u16 working_links;
u16 capabilities;
u32 signature;
u32 link_id;
struct list_head publ_list;
struct list_head conn_sks;
unsigned long keepalive_intv;
struct timer_list timer;
struct rcu_head rcu;
};
/* 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 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);
static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
static void tipc_node_put(struct tipc_node *node);
static bool tipc_node_is_up(struct tipc_node *n);
struct tipc_sock_conn {
u32 port;
u32 peer_port;
u32 peer_node;
struct list_head list;
};
static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
{
int bearer_id = n->active_links[sel & 1];
if (unlikely(bearer_id == INVALID_BEARER_ID))
return NULL;
return n->links[bearer_id].link;
}
int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel)
{
struct tipc_node *n;
int bearer_id;
unsigned int mtu = MAX_MSG_SIZE;
n = tipc_node_find(net, addr);
if (unlikely(!n))
return mtu;
bearer_id = n->active_links[sel & 1];
if (likely(bearer_id != INVALID_BEARER_ID))
mtu = n->links[bearer_id].mtu;
tipc_node_put(n);
return mtu;
}
u16 tipc_node_get_capabilities(struct net *net, u32 addr)
{
struct tipc_node *n;
u16 caps;
n = tipc_node_find(net, addr);
if (unlikely(!n))
return TIPC_NODE_CAPABILITIES;
caps = n->capabilities;
tipc_node_put(n);
return caps;
}
/*
* 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 *n = container_of(kref, struct tipc_node, kref);
kfree(n->bc_entry.link);
kfree_rcu(n, rcu);
}
static 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
*/
static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
{
struct tipc_net *tn = tipc_net(net);
struct tipc_node *node;
unsigned int thash = tipc_hashfn(addr);
if (unlikely(!in_own_cluster_exact(net, addr)))
return NULL;
rcu_read_lock();
hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
if (node->addr != addr)
continue;
if (!kref_get_unless_zero(&node->kref))
node = NULL;
break;
}
rcu_read_unlock();
return node;
}
static void tipc_node_read_lock(struct tipc_node *n)
{
read_lock_bh(&n->lock);
}
static void tipc_node_read_unlock(struct tipc_node *n)
{
read_unlock_bh(&n->lock);
}
static void tipc_node_write_lock(struct tipc_node *n)
{
write_lock_bh(&n->lock);
}
static void tipc_node_write_unlock(struct tipc_node *n)
{
struct net *net = n->net;
u32 addr = 0;
u32 flags = n->action_flags;
u32 link_id = 0;
struct list_head *publ_list;
if (likely(!flags)) {
write_unlock_bh(&n->lock);
return;
}
addr = n->addr;
link_id = n->link_id;
publ_list = &n->publ_list;
n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
write_unlock_bh(&n->lock);
if (flags & TIPC_NOTIFY_NODE_DOWN)
tipc_publ_notify(net, publ_list, addr);
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);
}
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, *temp_node;
int i;
spin_lock_bh(&tn->node_list_lock);
n = tipc_node_find(net, addr);
if (n) {
/* Same node may come back with new capabilities */
n->capabilities = capabilities;
goto exit;
}
n = kzalloc(sizeof(*n), GFP_ATOMIC);
if (!n) {
pr_warn("Node creation failed, no memory\n");
goto exit;
}
n->addr = addr;
n->net = net;
n->capabilities = capabilities;
kref_init(&n->kref);
rwlock_init(&n->lock);
INIT_HLIST_NODE(&n->hash);
INIT_LIST_HEAD(&n->list);
INIT_LIST_HEAD(&n->publ_list);
INIT_LIST_HEAD(&n->conn_sks);
skb_queue_head_init(&n->bc_entry.namedq);
skb_queue_head_init(&n->bc_entry.inputq1);
__skb_queue_head_init(&n->bc_entry.arrvq);
skb_queue_head_init(&n->bc_entry.inputq2);
for (i = 0; i < MAX_BEARERS; i++)
spin_lock_init(&n->links[i].lock);
n->state = SELF_DOWN_PEER_LEAVING;
n->signature = INVALID_NODE_SIG;
n->active_links[0] = INVALID_BEARER_ID;
n->active_links[1] = INVALID_BEARER_ID;
if (!tipc_link_bc_create(net, tipc_own_addr(net), n->addr,
U16_MAX,
tipc_link_window(tipc_bc_sndlink(net)),
n->capabilities,
&n->bc_entry.inputq1,
&n->bc_entry.namedq,
tipc_bc_sndlink(net),
&n->bc_entry.link)) {
pr_warn("Broadcast rcv link creation failed, no memory\n");
kfree(n);
n = NULL;
goto exit;
}
tipc_node_get(n);
setup_timer(&n->timer, tipc_node_timeout, (unsigned long)n);
n->keepalive_intv = U32_MAX;
hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
if (n->addr < temp_node->addr)
break;
}
list_add_tail_rcu(&n->list, &temp_node->list);
exit:
spin_unlock_bh(&tn->node_list_lock);
return n;
}
static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
{
unsigned long tol = tipc_link_tolerance(l);
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 */
tipc_link_set_abort_limit(l, tol / 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);
tipc_node_put(node);
del_timer_sync(&node->timer);
tipc_node_put(node);
}
void tipc_node_stop(struct net *net)
{
struct tipc_net *tn = tipc_net(net);
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_delete(node);
spin_unlock_bh(&tn->node_list_lock);
}
void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
{
struct tipc_node *n;
if (in_own_node(net, addr))
return;
n = tipc_node_find(net, addr);
if (!n) {
pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
return;
}
tipc_node_write_lock(n);
list_add_tail(subscr, &n->publ_list);
tipc_node_write_unlock(n);
tipc_node_put(n);
}
void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
{
struct tipc_node *n;
if (in_own_node(net, addr))
return;
n = tipc_node_find(net, addr);
if (!n) {
pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
return;
}
tipc_node_write_lock(n);
list_del_init(subscr);
tipc_node_write_unlock(n);
tipc_node_put(n);
}
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_write_lock(node);
list_add_tail(&conn->list, &node->conn_sks);
tipc_node_write_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_write_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_write_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_read_lock(n);
le = &n->links[bearer_id];
spin_lock_bh(&le->lock);
if (le->link) {
/* Link tolerance may change asynchronously: */
tipc_node_calculate_timer(n, le->link);
rc = tipc_link_timeout(le->link, &xmitq);
}
spin_unlock_bh(&le->lock);
tipc_node_read_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);
}
mod_timer(&n->timer, jiffies + n->keepalive_intv);
}
/**
* __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;
tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
if (!tipc_link_is_up(nl))
return;
n->working_links++;
n->action_flags |= TIPC_NOTIFY_LINK_UP;
n->link_id = tipc_link_id(nl);
/* Leave room for tunnel header when returning 'mtu' to users: */
n->links[bearer_id].mtu = tipc_link_mtu(nl) - INT_H_SIZE;
tipc_bearer_add_dest(n->net, bearer_id, n->addr);
tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
pr_debug("Established link <%s> on network plane %c\n",
tipc_link_name(nl), tipc_link_plane(nl));
/* Ensure that a STATE message goes first */
tipc_link_build_state_msg(nl, xmitq);
/* First link? => give it both slots */
if (!ol) {
*slot0 = bearer_id;
*slot1 = bearer_id;
tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
n->action_flags |= TIPC_NOTIFY_NODE_UP;
tipc_link_set_active(nl, true);
tipc_bcast_add_peer(n->net, nl, xmitq);
return;
}
/* Second link => redistribute slots */
if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
*slot0 = bearer_id;
*slot1 = bearer_id;
tipc_link_set_active(nl, true);
tipc_link_set_active(ol, false);
} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
tipc_link_set_active(nl, true);
*slot1 = bearer_id;
} else {
pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
}
/* 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)
{
struct tipc_media_addr *maddr;
tipc_node_write_lock(n);
__tipc_node_link_up(n, bearer_id, xmitq);
maddr = &n->links[bearer_id].maddr;
tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr);
tipc_node_write_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, prio;
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 = tipc_link_id(l);
tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
pr_debug("Lost link <%s> on network plane %c\n",
tipc_link_name(l), tipc_link_plane(l));
/* 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;
prio = tipc_link_prio(_l);
if (prio < highest)
continue;
if (prio > highest) {
highest = prio;
*slot0 = i;
*slot1 = i;
continue;
}
*slot1 = i;
}
if (!tipc_node_is_up(n)) {
if (tipc_link_peer_is_down(l))
tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
tipc_link_fsm_evt(l, LINK_RESET_EVT);
tipc_link_reset(l);
tipc_link_build_reset_msg(l, xmitq);
*maddr = &n->links[*bearer_id].maddr;
node_lost_contact(n, &le->inputq);
tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
return;
}
tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
/* There is still a working link => initiate failover */
*bearer_id = n->active_links[0];
tnl = n->links[*bearer_id].link;
tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
tipc_link_reset(l);
tipc_link_fsm_evt(l, LINK_RESET_EVT);
tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
*maddr = &n->links[*bearer_id].maddr;
}
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_link *l = le->link;
struct tipc_media_addr *maddr;
struct sk_buff_head xmitq;
if (!l)
return;
__skb_queue_head_init(&xmitq);
tipc_node_write_lock(n);
if (!tipc_link_is_establishing(l)) {
__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
if (delete) {
kfree(l);
le->link = NULL;
n->link_cnt--;
}
} else {
/* Defuse pending tipc_node_link_up() */
tipc_link_fsm_evt(l, LINK_RESET_EVT);
}
tipc_node_write_unlock(n);
tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
tipc_sk_rcv(n->net, &le->inputq);
}
static 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;
char *if_name;
*dupl_addr = false;
*respond = false;
n = tipc_node_create(net, onode, capabilities);
if (!n)
return;
tipc_node_write_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_name = strchr(b->name, ':') + 1;
if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
b->net_plane, b->mtu, b->priority,
b->window, mod(tipc_net(net)->random),
tipc_own_addr(net), onode,
n->capabilities,
tipc_bc_sndlink(n->net), n->bc_entry.link,
&le->inputq,
&n->bc_entry.namedq, &l)) {
*respond = false;
goto exit;
}
tipc_link_reset(l);
tipc_link_fsm_evt(l, LINK_RESET_EVT);
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_write_unlock(n);
if (reset && l && !tipc_link_is_reset(l))
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:
case NODE_SYNCH_END_EVT:
case NODE_FAILOVER_BEGIN_EVT:
break;
case NODE_SYNCH_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);
}
static void node_lost_contact(struct tipc_node *n,
struct sk_buff_head *inputq)
{
char addr_string[16];
struct tipc_sock_conn *conn, *safe;
struct tipc_link *l;
struct list_head *conns = &n->conn_sks;
struct sk_buff *skb;
uint i;
pr_debug("Lost contact with %s\n",
tipc_addr_string_fill(addr_string, n->addr));
/* Clean up broadcast state */
tipc_bcast_remove_peer(n->net, n->bc_entry.link);
/* Abort any ongoing link failover */
for (i = 0; i < MAX_BEARERS; i++) {
l = n->links[i].link;
if (l)
tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
}
/* Notify publications from this node */
n->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, tipc_own_addr(n->net),
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_read_lock(node);
link = node->links[bearer_id].link;
if (link) {
strncpy(linkname, tipc_link_name(link), len);
err = 0;
}
exit:
tipc_node_read_unlock(node);
tipc_node_put(node);
return err;
}
/* 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;
}
/**
* 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: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
*/
int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
u32 dnode, int selector)
{
struct tipc_link_entry *le = NULL;
struct tipc_node *n;
struct sk_buff_head xmitq;
int bearer_id;
int rc;
if (in_own_node(net, dnode)) {
tipc_sk_rcv(net, list);
return 0;
}
n = tipc_node_find(net, dnode);
if (unlikely(!n)) {
skb_queue_purge(list);
return -EHOSTUNREACH;
}
tipc_node_read_lock(n);
bearer_id = n->active_links[selector & 1];
if (unlikely(bearer_id == INVALID_BEARER_ID)) {
tipc_node_read_unlock(n);
tipc_node_put(n);
skb_queue_purge(list);
return -EHOSTUNREACH;
}
__skb_queue_head_init(&xmitq);
le = &n->links[bearer_id];
spin_lock_bh(&le->lock);
rc = tipc_link_xmit(le->link, list, &xmitq);
spin_unlock_bh(&le->lock);
tipc_node_read_unlock(n);
if (likely(rc == 0))
tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
else if (rc == -ENOBUFS)
tipc_node_link_down(n, bearer_id, false);
tipc_node_put(n);
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;
}
void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
{
struct sk_buff *txskb;
struct tipc_node *n;
u32 dst;
rcu_read_lock();
list_for_each_entry_rcu(n, tipc_nodes(net), list) {
dst = n->addr;
if (in_own_node(net, dst))
continue;
if (!tipc_node_is_up(n))
continue;
txskb = pskb_copy(skb, GFP_ATOMIC);
if (!txskb)
break;
msg_set_destnode(buf_msg(txskb), dst);
tipc_node_xmit_skb(net, txskb, dst, 0);
}
rcu_read_unlock();
kfree_skb(skb);
}
/**
* tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
* @net: the applicable net namespace
* @skb: TIPC packet
* @bearer_id: id of bearer message arrived on
*
* Invoked with no locks held.
*/
static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
{
int rc;
struct sk_buff_head xmitq;
struct tipc_bclink_entry *be;
struct tipc_link_entry *le;
struct tipc_msg *hdr = buf_msg(skb);
int usr = msg_user(hdr);
u32 dnode = msg_destnode(hdr);
struct tipc_node *n;
__skb_queue_head_init(&xmitq);
/* If NACK for other node, let rcv link for that node peek into it */
if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
n = tipc_node_find(net, dnode);
else
n = tipc_node_find(net, msg_prevnode(hdr));
if (!n) {
kfree_skb(skb);
return;
}
be = &n->bc_entry;
le = &n->links[bearer_id];
rc = tipc_bcast_rcv(net, be->link, skb);
/* Broadcast link reset may happen at reassembly failure */
if (rc & TIPC_LINK_DOWN_EVT)
tipc_node_reset_links(n);
/* Broadcast ACKs are sent on a unicast link */
if (rc & TIPC_LINK_SND_BC_ACK) {
tipc_node_read_lock(n);
tipc_link_build_state_msg(le->link, &xmitq);
tipc_node_read_unlock(n);
}
if (!skb_queue_empty(&xmitq))
tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
/* Deliver. 'arrvq' is under inputq2's lock protection */
if (!skb_queue_empty(&be->inputq1)) {
spin_lock_bh(&be->inputq2.lock);
spin_lock_bh(&be->inputq1.lock);
skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
spin_unlock_bh(&be->inputq1.lock);
spin_unlock_bh(&be->inputq2.lock);
tipc_sk_mcast_rcv(net, &be->arrvq, &be->inputq2);
}
tipc_node_put(n);
}
/**
* 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, inputq_len;
int state = n->state;
struct tipc_link *l, *tnl, *pl = NULL;
struct tipc_media_addr *maddr;
int pb_id;
l = n->links[bearer_id].link;
if (!l)
return false;
rcv_nxt = tipc_link_rcv_nxt(l);
if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
return true;
/* Find parallel link, if any */
for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
if ((pb_id != bearer_id) && n->links[pb_id].link) {
pl = n->links[pb_id].link;
break;
}
}
/* Check and 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);
return true;
}
if (state == SELF_LEAVING_PEER_DOWN)
return false;
/* Ignore duplicate packets */
if ((usr != LINK_PROTOCOL) && 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)) {
__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
tipc_link_inputq(l));
}
/* 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 synch mode if applicable */
if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
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);
}
}
/* Open tunnel link when parallel link reaches synch point */
if (n->state == NODE_SYNCHING) {
if (tipc_link_is_synching(l)) {
tnl = l;
} else {
tnl = pl;
pl = l;
}
inputq_len = skb_queue_len(tipc_link_inputq(pl));
dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
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;
u16 bc_ack = msg_bcast_ack(hdr);
u32 self = tipc_own_addr(net);
int rc = 0;
__skb_queue_head_init(&xmitq);
/* Ensure message is well-formed */
if (unlikely(!tipc_msg_validate(skb)))
goto discard;
/* Handle arrival of discovery or broadcast packet */
if (unlikely(msg_non_seq(hdr))) {
if (unlikely(usr == LINK_CONFIG))
return tipc_disc_rcv(net, skb, b);
else
return tipc_node_bc_rcv(net, skb, bearer_id);
}
/* Discard unicast link messages destined for another node */
if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
goto discard;
/* Locate neighboring node that sent packet */
n = tipc_node_find(net, msg_prevnode(hdr));
if (unlikely(!n))
goto discard;
le = &n->links[bearer_id];
/* Ensure broadcast reception is in synch with peer's send state */
if (unlikely(usr == LINK_PROTOCOL))
tipc_bcast_sync_rcv(net, n->bc_entry.link, hdr);
else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
tipc_bcast_ack_rcv(net, n->bc_entry.link, bc_ack);
/* Receive packet directly if conditions permit */
tipc_node_read_lock(n);
if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
spin_lock_bh(&le->lock);
if (le->link) {
rc = tipc_link_rcv(le->link, skb, &xmitq);
skb = NULL;
}
spin_unlock_bh(&le->lock);
}
tipc_node_read_unlock(n);
/* Check/update node state before receiving */
if (unlikely(skb)) {
tipc_node_write_lock(n);
if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
if (le->link) {
rc = tipc_link_rcv(le->link, skb, &xmitq);
skb = NULL;
}
}
tipc_node_write_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->bc_entry.namedq)))
tipc_named_rcv(net, &n->bc_entry.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_read_lock(node);
err = __tipc_nl_add_node(&msg, node);
if (err) {
last_addr = node->addr;
tipc_node_read_unlock(node);
goto out;
}
tipc_node_read_unlock(node);
}
done = 1;
out:
cb->args[0] = done;
cb->args[1] = last_addr;
rcu_read_unlock();
return skb->len;
}
/* tipc_node_find_by_name - locate owner node of link by link's name
* @net: the applicable net namespace
* @name: pointer to link name string
* @bearer_id: pointer to index in 'node->links' array where the link was found.
*
* Returns pointer to node owning the link, or 0 if no matching link is found.
*/
static struct tipc_node *tipc_node_find_by_name(struct net *net,
const char *link_name,
unsigned int *bearer_id)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_link *l;
struct tipc_node *n;
struct tipc_node *found_node = NULL;
int i;
*bearer_id = 0;
rcu_read_lock();
list_for_each_entry_rcu(n, &tn->node_list, list) {
tipc_node_read_lock(n);
for (i = 0; i < MAX_BEARERS; i++) {
l = n->links[i].link;
if (l && !strcmp(tipc_link_name(l), link_name)) {
*bearer_id = i;
found_node = n;
break;
}
}
tipc_node_read_unlock(n);
if (found_node)
break;
}
rcu_read_unlock();
return found_node;
}
int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
{
int err;
int res = 0;
int bearer_id;
char *name;
struct tipc_link *link;
struct tipc_node *node;
struct sk_buff_head xmitq;
struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
struct net *net = sock_net(skb->sk);
__skb_queue_head_init(&xmitq);
if (!info->attrs[TIPC_NLA_LINK])
return -EINVAL;
err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
info->attrs[TIPC_NLA_LINK],
tipc_nl_link_policy);
if (err)
return err;
if (!attrs[TIPC_NLA_LINK_NAME])
return -EINVAL;
name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
if (strcmp(name, tipc_bclink_name) == 0)
return tipc_nl_bc_link_set(net, attrs);
node = tipc_node_find_by_name(net, name, &bearer_id);
if (!node)
return -EINVAL;
tipc_node_read_lock(node);
link = node->links[bearer_id].link;
if (!link) {
res = -EINVAL;
goto out;
}
if (attrs[TIPC_NLA_LINK_PROP]) {
struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
props);
if (err) {
res = err;
goto out;
}
if (props[TIPC_NLA_PROP_TOL]) {
u32 tol;
tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
tipc_link_set_tolerance(link, tol, &xmitq);
}
if (props[TIPC_NLA_PROP_PRIO]) {
u32 prio;
prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
tipc_link_set_prio(link, prio, &xmitq);
}
if (props[TIPC_NLA_PROP_WIN]) {
u32 win;
win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
tipc_link_set_queue_limits(link, win);
}
}
out:
tipc_node_read_unlock(node);
tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
return res;
}
int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
{
struct net *net = genl_info_net(info);
struct tipc_nl_msg msg;
char *name;
int err;
msg.portid = info->snd_portid;
msg.seq = info->snd_seq;
if (!info->attrs[TIPC_NLA_LINK_NAME])
return -EINVAL;
name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!msg.skb)
return -ENOMEM;
if (strcmp(name, tipc_bclink_name) == 0) {
err = tipc_nl_add_bc_link(net, &msg);
if (err) {
nlmsg_free(msg.skb);
return err;
}
} else {
int bearer_id;
struct tipc_node *node;
struct tipc_link *link;
node = tipc_node_find_by_name(net, name, &bearer_id);
if (!node)
return -EINVAL;
tipc_node_read_lock(node);
link = node->links[bearer_id].link;
if (!link) {
tipc_node_read_unlock(node);
nlmsg_free(msg.skb);
return -EINVAL;
}
err = __tipc_nl_add_link(net, &msg, link, 0);
tipc_node_read_unlock(node);
if (err) {
nlmsg_free(msg.skb);
return err;
}
}
return genlmsg_reply(msg.skb, info);
}
int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
{
int err;
char *link_name;
unsigned int bearer_id;
struct tipc_link *link;
struct tipc_node *node;
struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
struct net *net = sock_net(skb->sk);
struct tipc_link_entry *le;
if (!info->attrs[TIPC_NLA_LINK])
return -EINVAL;
err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
info->attrs[TIPC_NLA_LINK],
tipc_nl_link_policy);
if (err)
return err;
if (!attrs[TIPC_NLA_LINK_NAME])
return -EINVAL;
link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
if (strcmp(link_name, tipc_bclink_name) == 0) {
err = tipc_bclink_reset_stats(net);
if (err)
return err;
return 0;
}
node = tipc_node_find_by_name(net, link_name, &bearer_id);
if (!node)
return -EINVAL;
le = &node->links[bearer_id];
tipc_node_read_lock(node);
spin_lock_bh(&le->lock);
link = node->links[bearer_id].link;
if (!link) {
spin_unlock_bh(&le->lock);
tipc_node_read_unlock(node);
return -EINVAL;
}
tipc_link_reset_stats(link);
spin_unlock_bh(&le->lock);
tipc_node_read_unlock(node);
return 0;
}
/* Caller should hold node lock */
static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
struct tipc_node *node, u32 *prev_link)
{
u32 i;
int err;
for (i = *prev_link; i < MAX_BEARERS; i++) {
*prev_link = i;
if (!node->links[i].link)
continue;
err = __tipc_nl_add_link(net, msg,
node->links[i].link, NLM_F_MULTI);
if (err)
return err;
}
*prev_link = 0;
return 0;
}
int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_node *node;
struct tipc_nl_msg msg;
u32 prev_node = cb->args[0];
u32 prev_link = cb->args[1];
int done = cb->args[2];
int err;
if (done)
return 0;
msg.skb = skb;
msg.portid = NETLINK_CB(cb->skb).portid;
msg.seq = cb->nlh->nlmsg_seq;
rcu_read_lock();
if (prev_node) {
node = tipc_node_find(net, prev_node);
if (!node) {
/* 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 last NLMSG_DONE message
* having the NLM_F_DUMP_INTR flag set.
*/
cb->prev_seq = 1;
goto out;
}
tipc_node_put(node);
list_for_each_entry_continue_rcu(node, &tn->node_list,
list) {
tipc_node_read_lock(node);
err = __tipc_nl_add_node_links(net, &msg, node,
&prev_link);
tipc_node_read_unlock(node);
if (err)
goto out;
prev_node = node->addr;
}
} else {
err = tipc_nl_add_bc_link(net, &msg);
if (err)
goto out;
list_for_each_entry_rcu(node, &tn->node_list, list) {
tipc_node_read_lock(node);
err = __tipc_nl_add_node_links(net, &msg, node,
&prev_link);
tipc_node_read_unlock(node);
if (err)
goto out;
prev_node = node->addr;
}
}
done = 1;
out:
rcu_read_unlock();
cb->args[0] = prev_node;
cb->args[1] = prev_link;
cb->args[2] = done;
return skb->len;
}