blob: 669af125b3de4a8694fbd3d4b8df802ccd6706e6 [file] [log] [blame]
/*
* net/tipc/discover.c
*
* Copyright (c) 2003-2006, 2014-2015, Ericsson AB
* Copyright (c) 2005-2006, 2010-2011, 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 "node.h"
#include "discover.h"
/* min delay during bearer start up */
#define TIPC_DISC_INIT msecs_to_jiffies(125)
/* max delay if bearer has no links */
#define TIPC_DISC_FAST msecs_to_jiffies(1000)
/* max delay if bearer has links */
#define TIPC_DISC_SLOW msecs_to_jiffies(60000)
/* indicates no timer in use */
#define TIPC_DISC_INACTIVE 0xffffffff
/**
* struct tipc_discoverer - information about an ongoing link setup request
* @bearer_id: identity of bearer issuing requests
* @net: network namespace instance
* @dest: destination address for request messages
* @domain: network domain to which links can be established
* @num_nodes: number of nodes currently discovered (i.e. with an active link)
* @lock: spinlock for controlling access to requests
* @skb: request message to be (repeatedly) sent
* @timer: timer governing period between requests
* @timer_intv: current interval between requests (in ms)
*/
struct tipc_discoverer {
u32 bearer_id;
struct tipc_media_addr dest;
struct net *net;
u32 domain;
int num_nodes;
spinlock_t lock;
struct sk_buff *skb;
struct timer_list timer;
unsigned long timer_intv;
};
/**
* tipc_disc_init_msg - initialize a link setup message
* @net: the applicable net namespace
* @type: message type (request or response)
* @b: ptr to bearer issuing message
*/
static void tipc_disc_init_msg(struct net *net, struct sk_buff *skb,
u32 mtyp, struct tipc_bearer *b)
{
struct tipc_net *tn = tipc_net(net);
u32 dest_domain = b->domain;
struct tipc_msg *hdr;
hdr = buf_msg(skb);
tipc_msg_init(tn->own_addr, hdr, LINK_CONFIG, mtyp,
MAX_H_SIZE, dest_domain);
msg_set_non_seq(hdr, 1);
msg_set_node_sig(hdr, tn->random);
msg_set_node_capabilities(hdr, TIPC_NODE_CAPABILITIES);
msg_set_dest_domain(hdr, dest_domain);
msg_set_bc_netid(hdr, tn->net_id);
b->media->addr2msg(msg_media_addr(hdr), &b->addr);
}
static void tipc_disc_msg_xmit(struct net *net, u32 mtyp, u32 dst, u32 src,
struct tipc_media_addr *maddr,
struct tipc_bearer *b)
{
struct sk_buff *skb;
skb = tipc_buf_acquire(MAX_H_SIZE, GFP_ATOMIC);
if (!skb)
return;
tipc_disc_init_msg(net, skb, mtyp, b);
tipc_bearer_xmit_skb(net, b->identity, skb, maddr);
}
/**
* disc_dupl_alert - issue node address duplication alert
* @b: pointer to bearer detecting duplication
* @node_addr: duplicated node address
* @media_addr: media address advertised by duplicated node
*/
static void disc_dupl_alert(struct tipc_bearer *b, u32 node_addr,
struct tipc_media_addr *media_addr)
{
char node_addr_str[16];
char media_addr_str[64];
tipc_addr_string_fill(node_addr_str, node_addr);
tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str),
media_addr);
pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str,
media_addr_str, b->name);
}
/**
* tipc_disc_rcv - handle incoming discovery message (request or response)
* @net: applicable net namespace
* @skb: buffer containing message
* @b: bearer that message arrived on
*/
void tipc_disc_rcv(struct net *net, struct sk_buff *skb,
struct tipc_bearer *b)
{
struct tipc_net *tn = tipc_net(net);
struct tipc_msg *hdr = buf_msg(skb);
u16 caps = msg_node_capabilities(hdr);
u32 signature = msg_node_sig(hdr);
u32 dst = msg_dest_domain(hdr);
u32 net_id = msg_bc_netid(hdr);
u32 self = tipc_own_addr(net);
struct tipc_media_addr maddr;
u32 src = msg_prevnode(hdr);
u32 mtyp = msg_type(hdr);
bool dupl_addr = false;
bool respond = false;
int err;
err = b->media->msg2addr(b, &maddr, msg_media_addr(hdr));
kfree_skb(skb);
if (err || maddr.broadcast) {
pr_warn_ratelimited("Rcv corrupt discovery message\n");
return;
}
/* Ignore discovery messages from own node */
if (!memcmp(&maddr, &b->addr, sizeof(maddr)))
return;
if (net_id != tn->net_id)
return;
if (in_own_node(net, src)) {
disc_dupl_alert(b, self, &maddr);
return;
}
/* Domain filter only works if both peers use legacy address format */
if (b->domain) {
if (!tipc_in_scope(dst, self))
return;
if (!tipc_in_scope(b->domain, src))
return;
}
tipc_node_check_dest(net, src, b, caps, signature,
&maddr, &respond, &dupl_addr);
if (dupl_addr)
disc_dupl_alert(b, src, &maddr);
if (!respond)
return;
if (mtyp != DSC_REQ_MSG)
return;
tipc_disc_msg_xmit(net, DSC_RESP_MSG, src, self, &maddr, b);
}
/* tipc_disc_add_dest - increment set of discovered nodes
*/
void tipc_disc_add_dest(struct tipc_discoverer *d)
{
spin_lock_bh(&d->lock);
d->num_nodes++;
spin_unlock_bh(&d->lock);
}
/* tipc_disc_remove_dest - decrement set of discovered nodes
*/
void tipc_disc_remove_dest(struct tipc_discoverer *d)
{
int intv, num;
spin_lock_bh(&d->lock);
d->num_nodes--;
num = d->num_nodes;
intv = d->timer_intv;
if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) {
d->timer_intv = TIPC_DISC_INIT;
mod_timer(&d->timer, jiffies + d->timer_intv);
}
spin_unlock_bh(&d->lock);
}
/* tipc_disc_timeout - send a periodic link setup request
* Called whenever a link setup request timer associated with a bearer expires.
* - Keep doubling time between sent request until limit is reached;
* - Hold at fast polling rate if we don't have any associated nodes
* - Otherwise hold at slow polling rate
*/
static void tipc_disc_timeout(struct timer_list *t)
{
struct tipc_discoverer *d = from_timer(d, t, timer);
struct tipc_media_addr maddr;
struct sk_buff *skb = NULL;
struct net *net;
u32 bearer_id;
spin_lock_bh(&d->lock);
/* Stop searching if only desired node has been found */
if (tipc_node(d->domain) && d->num_nodes) {
d->timer_intv = TIPC_DISC_INACTIVE;
goto exit;
}
/* Adjust timeout interval according to discovery phase */
d->timer_intv *= 2;
if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW)
d->timer_intv = TIPC_DISC_SLOW;
else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST)
d->timer_intv = TIPC_DISC_FAST;
mod_timer(&d->timer, jiffies + d->timer_intv);
memcpy(&maddr, &d->dest, sizeof(maddr));
skb = skb_clone(d->skb, GFP_ATOMIC);
net = d->net;
bearer_id = d->bearer_id;
exit:
spin_unlock_bh(&d->lock);
if (skb)
tipc_bearer_xmit_skb(net, bearer_id, skb, &maddr);
}
/**
* tipc_disc_create - create object to send periodic link setup requests
* @net: the applicable net namespace
* @b: ptr to bearer issuing requests
* @dest: destination address for request messages
* @dest_domain: network domain to which links can be established
*
* Returns 0 if successful, otherwise -errno.
*/
int tipc_disc_create(struct net *net, struct tipc_bearer *b,
struct tipc_media_addr *dest, struct sk_buff **skb)
{
struct tipc_discoverer *d;
d = kmalloc(sizeof(*d), GFP_ATOMIC);
if (!d)
return -ENOMEM;
d->skb = tipc_buf_acquire(MAX_H_SIZE, GFP_ATOMIC);
if (!d->skb) {
kfree(d);
return -ENOMEM;
}
tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
memcpy(&d->dest, dest, sizeof(*dest));
d->net = net;
d->bearer_id = b->identity;
d->domain = b->domain;
d->num_nodes = 0;
d->timer_intv = TIPC_DISC_INIT;
spin_lock_init(&d->lock);
timer_setup(&d->timer, tipc_disc_timeout, 0);
mod_timer(&d->timer, jiffies + d->timer_intv);
b->disc = d;
*skb = skb_clone(d->skb, GFP_ATOMIC);
return 0;
}
/**
* tipc_disc_delete - destroy object sending periodic link setup requests
* @d: ptr to link duest structure
*/
void tipc_disc_delete(struct tipc_discoverer *d)
{
del_timer_sync(&d->timer);
kfree_skb(d->skb);
kfree(d);
}
/**
* tipc_disc_reset - reset object to send periodic link setup requests
* @net: the applicable net namespace
* @b: ptr to bearer issuing requests
* @dest_domain: network domain to which links can be established
*/
void tipc_disc_reset(struct net *net, struct tipc_bearer *b)
{
struct tipc_discoverer *d = b->disc;
struct tipc_media_addr maddr;
struct sk_buff *skb;
spin_lock_bh(&d->lock);
tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
d->net = net;
d->bearer_id = b->identity;
d->domain = b->domain;
d->num_nodes = 0;
d->timer_intv = TIPC_DISC_INIT;
memcpy(&maddr, &d->dest, sizeof(maddr));
mod_timer(&d->timer, jiffies + d->timer_intv);
skb = skb_clone(d->skb, GFP_ATOMIC);
spin_unlock_bh(&d->lock);
if (skb)
tipc_bearer_xmit_skb(net, b->identity, skb, &maddr);
}