/**
* tipc_disc_rcv - handle incoming discovery message (request or response)
* @net: the applicable net namespace
* @buf: buffer containing message
* @bearer: bearer that message arrived on
*/
void tipc_disc_rcv(struct net *net, struct sk_buff *skb,
struct tipc_bearer *bearer)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_media_addr maddr;
struct sk_buff *rskb;
struct tipc_msg *hdr = buf_msg(skb);
u32 ddom = msg_dest_domain(hdr);
u32 onode = msg_prevnode(hdr);
u32 net_id = msg_bc_netid(hdr);
u32 mtyp = msg_type(hdr);
u32 signature = msg_node_sig(hdr);
u16 caps = msg_node_capabilities(hdr);
bool respond = false;
bool dupl_addr = false;
int err;
err = bearer->media->msg2addr(bearer, &maddr, msg_media_addr(hdr));
kfree_skb(skb);
if (err)
return;
/* Ensure message from node is valid and communication is permitted */
if (net_id != tn->net_id)
return;
if (maddr.broadcast)
return;
if (!tipc_addr_domain_valid(ddom))
return;
if (!tipc_addr_node_valid(onode))
return;
if (in_own_node(net, onode)) {
if (memcmp(&maddr, &bearer->addr, sizeof(maddr)))
disc_dupl_alert(bearer, tn->own_addr, &maddr);
return;
}
if (!tipc_in_scope(ddom, tn->own_addr))
return;
if (!tipc_in_scope(bearer->domain, onode))
return;
tipc_node_check_dest(net, onode, bearer, caps, signature,
&maddr, &respond, &dupl_addr);
if (dupl_addr)
disc_dupl_alert(bearer, onode, &maddr);
/* Send response, if necessary */
if (respond && (mtyp == DSC_REQ_MSG)) {
rskb = tipc_buf_acquire(MAX_H_SIZE, GFP_ATOMIC);
if (!rskb)
return;
tipc_disc_init_msg(net, rskb, DSC_RESP_MSG, bearer);
tipc_bearer_xmit_skb(net, bearer->identity, rskb, &maddr);
}
}
/**
* 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_link_req *req = b->link_req;
struct sk_buff *skb;
spin_lock_bh(&req->lock);
tipc_disc_init_msg(net, req->buf, DSC_REQ_MSG, b);
req->net = net;
req->bearer_id = b->identity;
req->domain = b->domain;
req->num_nodes = 0;
req->timer_intv = TIPC_LINK_REQ_INIT;
mod_timer(&req->timer, jiffies + req->timer_intv);
skb = skb_clone(req->buf, GFP_ATOMIC);
if (skb)
tipc_bearer_xmit_skb(net, req->bearer_id, skb, &req->dest);
spin_unlock_bh(&req->lock);
}
/**
* disc_timeout - send a periodic link setup request
* @data: ptr to link request structure
*
* Called whenever a link setup request timer associated with a bearer expires.
*/
static void disc_timeout(struct timer_list *t)
{
struct tipc_link_req *req = from_timer(req, t, timer);
struct sk_buff *skb;
int max_delay;
spin_lock_bh(&req->lock);
/* Stop searching if only desired node has been found */
if (tipc_node(req->domain) && req->num_nodes) {
req->timer_intv = TIPC_LINK_REQ_INACTIVE;
goto exit;
}
/*
* Send discovery message, then update discovery timer
*
* Keep doubling time between requests until limit is reached;
* hold at fast polling rate if don't have any associated nodes,
* otherwise hold at slow polling rate
*/
skb = skb_clone(req->buf, GFP_ATOMIC);
if (skb)
tipc_bearer_xmit_skb(req->net, req->bearer_id, skb, &req->dest);
req->timer_intv *= 2;
if (req->num_nodes)
max_delay = TIPC_LINK_REQ_SLOW;
else
max_delay = TIPC_LINK_REQ_FAST;
if (req->timer_intv > max_delay)
req->timer_intv = max_delay;
mod_timer(&req->timer, jiffies + req->timer_intv);
exit:
spin_unlock_bh(&req->lock);
}
/**
* tipc_enable_bearer - enable bearer with the given name
*/
static int tipc_enable_bearer(struct net *net, const char *name,
u32 disc_domain, u32 prio,
struct nlattr *attr[])
{
struct tipc_net *tn = tipc_net(net);
struct tipc_bearer_names b_names;
int with_this_prio = 1;
struct tipc_bearer *b;
struct tipc_media *m;
struct sk_buff *skb;
int bearer_id = 0;
int res = -EINVAL;
char *errstr = "";
if (!bearer_name_validate(name, &b_names)) {
errstr = "illegal name";
goto rejected;
}
if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
errstr = "illegal priority";
goto rejected;
}
m = tipc_media_find(b_names.media_name);
if (!m) {
errstr = "media not registered";
goto rejected;
}
if (prio == TIPC_MEDIA_LINK_PRI)
prio = m->priority;
/* Check new bearer vs existing ones and find free bearer id if any */
while (bearer_id < MAX_BEARERS) {
b = rtnl_dereference(tn->bearer_list[bearer_id]);
if (!b)
break;
if (!strcmp(name, b->name)) {
errstr = "already enabled";
goto rejected;
}
bearer_id++;
if (b->priority != prio)
continue;
if (++with_this_prio <= 2)
continue;
pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
name, prio);
if (prio == TIPC_MIN_LINK_PRI) {
errstr = "cannot adjust to lower";
goto rejected;
}
pr_warn("Bearer <%s>: trying with adjusted priority\n", name);
prio--;
bearer_id = 0;
with_this_prio = 1;
}
if (bearer_id >= MAX_BEARERS) {
errstr = "max 3 bearers permitted";
goto rejected;
}
b = kzalloc(sizeof(*b), GFP_ATOMIC);
if (!b)
return -ENOMEM;
strcpy(b->name, name);
b->media = m;
res = m->enable_media(net, b, attr);
if (res) {
kfree(b);
errstr = "failed to enable media";
goto rejected;
}
b->identity = bearer_id;
b->tolerance = m->tolerance;
b->window = m->window;
b->domain = disc_domain;
b->net_plane = bearer_id + 'A';
b->priority = prio;
test_and_set_bit_lock(0, &b->up);
res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
if (res) {
bearer_disable(net, b);
kfree(b);
errstr = "failed to create discoverer";
goto rejected;
}
rcu_assign_pointer(tn->bearer_list[bearer_id], b);
if (skb)
tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
if (tipc_mon_create(net, bearer_id)) {
bearer_disable(net, b);
return -ENOMEM;
}
pr_info("Enabled bearer <%s>, priority %u\n", name, prio);
return res;
rejected:
pr_warn("Enabling of bearer <%s> rejected, %s\n", name, errstr);
return res;
}
/**
* tipc_enable_bearer - enable bearer with the given name
*/
static int tipc_enable_bearer(struct net *net, const char *name,
u32 disc_domain, u32 priority,
struct nlattr *attr[])
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_bearer *b;
struct tipc_media *m;
struct tipc_bearer_names b_names;
struct sk_buff *skb;
char addr_string[16];
u32 bearer_id;
u32 with_this_prio;
u32 i;
int res = -EINVAL;
if (!tn->own_addr) {
pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
name);
return -ENOPROTOOPT;
}
if (!bearer_name_validate(name, &b_names)) {
pr_warn("Bearer <%s> rejected, illegal name\n", name);
return -EINVAL;
}
if (tipc_addr_domain_valid(disc_domain) &&
(disc_domain != tn->own_addr)) {
if (tipc_in_scope(disc_domain, tn->own_addr)) {
disc_domain = tn->own_addr & TIPC_CLUSTER_MASK;
res = 0; /* accept any node in own cluster */
} else if (in_own_cluster_exact(net, disc_domain))
res = 0; /* accept specified node in own cluster */
}
if (res) {
pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
name);
return -EINVAL;
}
if ((priority > TIPC_MAX_LINK_PRI) &&
(priority != TIPC_MEDIA_LINK_PRI)) {
pr_warn("Bearer <%s> rejected, illegal priority\n", name);
return -EINVAL;
}
m = tipc_media_find(b_names.media_name);
if (!m) {
pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
name, b_names.media_name);
return -EINVAL;
}
if (priority == TIPC_MEDIA_LINK_PRI)
priority = m->priority;
restart:
bearer_id = MAX_BEARERS;
with_this_prio = 1;
for (i = MAX_BEARERS; i-- != 0; ) {
b = rtnl_dereference(tn->bearer_list[i]);
if (!b) {
bearer_id = i;
continue;
}
if (!strcmp(name, b->name)) {
pr_warn("Bearer <%s> rejected, already enabled\n",
name);
return -EINVAL;
}
if ((b->priority == priority) &&
(++with_this_prio > 2)) {
if (priority-- == 0) {
pr_warn("Bearer <%s> rejected, duplicate priority\n",
name);
return -EINVAL;
}
pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
name, priority + 1, priority);
goto restart;
}
}
if (bearer_id >= MAX_BEARERS) {
pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
name, MAX_BEARERS);
return -EINVAL;
}
b = kzalloc(sizeof(*b), GFP_ATOMIC);
if (!b)
return -ENOMEM;
strcpy(b->name, name);
b->media = m;
res = m->enable_media(net, b, attr);
if (res) {
pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
name, -res);
return -EINVAL;
}
b->identity = bearer_id;
b->tolerance = m->tolerance;
b->window = m->window;
b->domain = disc_domain;
b->net_plane = bearer_id + 'A';
b->priority = priority;
res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
if (res) {
bearer_disable(net, b);
pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
name);
return -EINVAL;
}
rcu_assign_pointer(tn->bearer_list[bearer_id], b);
if (skb)
tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
name,
tipc_addr_string_fill(addr_string, disc_domain), priority);
return res;
}
