1 files changed, 415 insertions, 0 deletions
diff --git a/net/tipc/discover.c b/net/tipc/discover.c
new file mode 100644
index 000000000..c138d68e8
--- /dev/null
+++ b/net/tipc/discover.c
@@ -0,0 +1,415 @@
+/*
+ * net/tipc/discover.c
+ *
+ * Copyright (c) 2003-2006, 2014-2018, 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->trial_addr, hdr, LINK_CONFIG, mtyp,
+		      MAX_H_SIZE, dest_domain);
+	msg_set_size(hdr, MAX_H_SIZE + NODE_ID_LEN);
+	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);
+	msg_set_node_id(hdr, tipc_own_id(net));
+}
+
+static void tipc_disc_msg_xmit(struct net *net, u32 mtyp, u32 dst,
+			       u32 src, u32 sugg_addr,
+			       struct tipc_media_addr *maddr,
+			       struct tipc_bearer *b)
+{
+	struct tipc_msg *hdr;
+	struct sk_buff *skb;
+
+	skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC);
+	if (!skb)
+		return;
+	hdr = buf_msg(skb);
+	tipc_disc_init_msg(net, skb, mtyp, b);
+	msg_set_sugg_node_addr(hdr, sugg_addr);
+	msg_set_dest_domain(hdr, dst);
+	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 media_addr_str[64];
+
+	tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str),
+			       media_addr);
+	pr_warn("Duplicate %x using %s seen on <%s>\n", node_addr,
+		media_addr_str, b->name);
+}
+
+/* tipc_disc_addr_trial(): - handle an address uniqueness trial from peer
+ * Returns true if message should be dropped by caller, i.e., if it is a
+ * trial message or we are inside trial period. Otherwise false.
+ */
+static bool tipc_disc_addr_trial_msg(struct tipc_discoverer *d,
+				     struct tipc_media_addr *maddr,
+				     struct tipc_bearer *b,
+				     u32 dst, u32 src,
+				     u32 sugg_addr,
+				     u8 *peer_id,
+				     int mtyp)
+{
+	struct net *net = d->net;
+	struct tipc_net *tn = tipc_net(net);
+	bool trial = time_before(jiffies, tn->addr_trial_end);
+	u32 self = tipc_own_addr(net);
+
+	if (mtyp == DSC_TRIAL_FAIL_MSG) {
+		if (!trial)
+			return true;
+
+		/* Ignore if somebody else already gave new suggestion */
+		if (dst != tn->trial_addr)
+			return true;
+
+		/* Otherwise update trial address and restart trial period */
+		tn->trial_addr = sugg_addr;
+		msg_set_prevnode(buf_msg(d->skb), sugg_addr);
+		tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
+		return true;
+	}
+
+	/* Apply trial address if we just left trial period */
+	if (!trial && !self) {
+		tipc_sched_net_finalize(net, tn->trial_addr);
+		msg_set_prevnode(buf_msg(d->skb), tn->trial_addr);
+		msg_set_type(buf_msg(d->skb), DSC_REQ_MSG);
+	}
+
+	/* Accept regular link requests/responses only after trial period */
+	if (mtyp != DSC_TRIAL_MSG)
+		return trial;
+
+	sugg_addr = tipc_node_try_addr(net, peer_id, src);
+	if (sugg_addr)
+		tipc_disc_msg_xmit(net, DSC_TRIAL_FAIL_MSG, src,
+				   self, sugg_addr, maddr, b);
+	return true;
+}
+
+/**
+ * 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);
+	bool legacy = tn->legacy_addr_format;
+	u32 sugg = msg_sugg_node_addr(hdr);
+	u32 signature = msg_node_sig(hdr);
+	u8 peer_id[NODE_ID_LEN] = {0,};
+	u32 dst = msg_dest_domain(hdr);
+	u32 net_id = msg_bc_netid(hdr);
+	struct tipc_media_addr maddr;
+	u32 src = msg_prevnode(hdr);
+	u32 mtyp = msg_type(hdr);
+	bool dupl_addr = false;
+	bool respond = false;
+	u32 self;
+	int err;
+
+	skb_linearize(skb);
+	hdr = buf_msg(skb);
+
+	if (caps & TIPC_NODE_ID128)
+		memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN);
+	else
+		sprintf(peer_id, "%x", src);
+
+	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 (tipc_disc_addr_trial_msg(b->disc, &maddr, b, dst,
+				     src, sugg, peer_id, mtyp))
+		return;
+	self = tipc_own_addr(net);
+
+	/* Message from somebody using this node's address */
+	if (in_own_node(net, src)) {
+		disc_dupl_alert(b, self, &maddr);
+		return;
+	}
+	if (!tipc_in_scope(legacy, dst, self))
+		return;
+	if (!tipc_in_scope(legacy, b->domain, src))
+		return;
+	tipc_node_check_dest(net, src, peer_id, 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, 0, &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_net *tn = tipc_net(d->net);
+	struct tipc_media_addr maddr;
+	struct sk_buff *skb = NULL;
+	struct net *net = d->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;
+	}
+
+	/* Did we just leave trial period ? */
+	if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) {
+		mod_timer(&d->timer, jiffies + TIPC_DISC_INIT);
+		spin_unlock_bh(&d->lock);
+		tipc_sched_net_finalize(net, tn->trial_addr);
+		return;
+	}
+
+	/* Adjust timeout interval according to discovery phase */
+	if (time_before(jiffies, tn->addr_trial_end)) {
+		d->timer_intv = TIPC_DISC_INIT;
+	} else {
+		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;
+		msg_set_type(buf_msg(d->skb), DSC_REQ_MSG);
+		msg_set_prevnode(buf_msg(d->skb), tn->trial_addr);
+	}
+
+	mod_timer(&d->timer, jiffies + d->timer_intv);
+	memcpy(&maddr, &d->dest, sizeof(maddr));
+	skb = skb_clone(d->skb, GFP_ATOMIC);
+	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_net *tn = tipc_net(net);
+	struct tipc_discoverer *d;
+
+	d = kmalloc(sizeof(*d), GFP_ATOMIC);
+	if (!d)
+		return -ENOMEM;
+	d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC);
+	if (!d->skb) {
+		kfree(d);
+		return -ENOMEM;
+	}
+	tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
+
+	/* Do we need an address trial period first ? */
+	if (!tipc_own_addr(net)) {
+		tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
+		msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG);
+	}
+	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);
+}