[TIPC] Initial merge

TIPC (Transparent Inter Process Communication) is a protocol designed for
intra cluster communication. For more information see
http://tipc.sourceforge.net

Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>

1 files changed, 3164 insertions, 0 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
new file mode 100644
index 00000000000..92acb80bb24
--- /dev/null
+++ b/net/tipc/link.c
@@ -0,0 +1,3164 @@
+/*
+ * net/tipc/link.c: TIPC link code
+ * 
+ * Copyright (c) 2003-2005, Ericsson Research Canada
+ * Copyright (c) 2004-2005, Wind River Systems
+ * Copyright (c) 2005-2006, Ericsson AB
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this 
+ * list of conditions and the following disclaimer.
+ * 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.
+ * 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.
+ *
+ * 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 "dbg.h"
+#include "link.h"
+#include "net.h"
+#include "node.h"
+#include "port.h"
+#include "addr.h"
+#include "node_subscr.h"
+#include "name_distr.h"
+#include "bearer.h"
+#include "name_table.h"
+#include "discover.h"
+#include "config.h"
+#include "bcast.h"
+
+
+/* 
+ * Limit for deferred reception queue: 
+ */
+
+#define DEF_QUEUE_LIMIT 256u
+
+/* 
+ * Link state events: 
+ */
+
+#define  STARTING_EVT    856384768	/* link processing trigger */
+#define  TRAFFIC_MSG_EVT 560815u	/* rx'd ??? */
+#define  TIMEOUT_EVT     560817u	/* link timer expired */
+
+/*   
+ * The following two 'message types' is really just implementation 
+ * data conveniently stored in the message header. 
+ * They must not be considered part of the protocol
+ */
+#define OPEN_MSG   0
+#define CLOSED_MSG 1
+
+/* 
+ * State value stored in 'exp_msg_count'
+ */
+
+#define START_CHANGEOVER 100000u
+
+/**
+ * struct link_name - deconstructed link name
+ * @addr_local: network address of node at this end
+ * @if_local: name of interface at this end
+ * @addr_peer: network address of node at far end
+ * @if_peer: name of interface at far end
+ */
+
+struct link_name {
+	u32 addr_local;
+	char if_local[TIPC_MAX_IF_NAME];
+	u32 addr_peer;
+	char if_peer[TIPC_MAX_IF_NAME];
+};
+
+#if 0
+
+/* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
+
+/** 
+ * struct link_event - link up/down event notification
+ */
+
+struct link_event {
+	u32 addr;
+	int up;
+	void (*fcn)(u32, char *, int);
+	char name[TIPC_MAX_LINK_NAME];
+};
+
+#endif
+
+static void link_handle_out_of_seq_msg(struct link *l_ptr,
+				       struct sk_buff *buf);
+static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf);
+static int  link_recv_changeover_msg(struct link **l_ptr, struct sk_buff **buf);
+static void link_set_supervision_props(struct link *l_ptr, u32 tolerance);
+static int  link_send_sections_long(struct port *sender,
+				    struct iovec const *msg_sect,
+				    u32 num_sect, u32 destnode);
+static void link_check_defragm_bufs(struct link *l_ptr);
+static void link_state_event(struct link *l_ptr, u32 event);
+static void link_reset_statistics(struct link *l_ptr);
+static void link_print(struct link *l_ptr, struct print_buf *buf, 
+		       const char *str);
+
+/*
+ * Debugging code used by link routines only
+ *
+ * When debugging link problems on a system that has multiple links,
+ * the standard TIPC debugging routines may not be useful since they
+ * allow the output from multiple links to be intermixed.  For this reason
+ * routines of the form "dbg_link_XXX()" have been created that will capture
+ * debug info into a link's personal print buffer, which can then be dumped
+ * into the TIPC system log (LOG) upon request.
+ *
+ * To enable per-link debugging, use LINK_LOG_BUF_SIZE to specify the size
+ * of the print buffer used by each link.  If LINK_LOG_BUF_SIZE is set to 0,
+ * the dbg_link_XXX() routines simply send their output to the standard 
+ * debug print buffer (DBG_OUTPUT), if it has been defined; this can be useful
+ * when there is only a single link in the system being debugged.
+ *
+ * Notes:
+ * - When enabled, LINK_LOG_BUF_SIZE should be set to at least 1000 (bytes)
+ * - "l_ptr" must be valid when using dbg_link_XXX() macros  
+ */
+
+#define LINK_LOG_BUF_SIZE 0
+
+#define dbg_link(fmt, arg...)  do {if (LINK_LOG_BUF_SIZE) tipc_printf(&l_ptr->print_buf, fmt, ## arg); } while(0)
+#define dbg_link_msg(msg, txt) do {if (LINK_LOG_BUF_SIZE) msg_print(&l_ptr->print_buf, msg, txt); } while(0)
+#define dbg_link_state(txt) do {if (LINK_LOG_BUF_SIZE) link_print(l_ptr, &l_ptr->print_buf, txt); } while(0)
+#define dbg_link_dump() do { \
+	if (LINK_LOG_BUF_SIZE) { \
+		tipc_printf(LOG, "\n\nDumping link <%s>:\n", l_ptr->name); \
+		printbuf_move(LOG, &l_ptr->print_buf); \
+	} \
+} while (0)
+
+static inline void dbg_print_link(struct link *l_ptr, const char *str)
+{
+	if (DBG_OUTPUT)
+		link_print(l_ptr, DBG_OUTPUT, str);
+}
+
+static inline void dbg_print_buf_chain(struct sk_buff *root_buf)
+{
+	if (DBG_OUTPUT) {
+		struct sk_buff *buf = root_buf;
+
+		while (buf) {
+			msg_dbg(buf_msg(buf), "In chain: ");
+			buf = buf->next;
+		}
+	}
+}
+
+/*
+ *  Simple inlined link routines
+ */
+
+static inline unsigned int align(unsigned int i)
+{
+	return (i + 3) & ~3u;
+}
+
+static inline int link_working_working(struct link *l_ptr)
+{
+	return (l_ptr->state == WORKING_WORKING);
+}
+
+static inline int link_working_unknown(struct link *l_ptr)
+{
+	return (l_ptr->state == WORKING_UNKNOWN);
+}
+
+static inline int link_reset_unknown(struct link *l_ptr)
+{
+	return (l_ptr->state == RESET_UNKNOWN);
+}
+
+static inline int link_reset_reset(struct link *l_ptr)
+{
+	return (l_ptr->state == RESET_RESET);
+}
+
+static inline int link_blocked(struct link *l_ptr)
+{
+	return (l_ptr->exp_msg_count || l_ptr->blocked);
+}
+
+static inline int link_congested(struct link *l_ptr)
+{
+	return (l_ptr->out_queue_size >= l_ptr->queue_limit[0]);
+}
+
+static inline u32 link_max_pkt(struct link *l_ptr)
+{
+	return l_ptr->max_pkt;
+}
+
+static inline void link_init_max_pkt(struct link *l_ptr)
+{
+	u32 max_pkt;
+	
+	max_pkt = (l_ptr->b_ptr->publ.mtu & ~3);
+	if (max_pkt > MAX_MSG_SIZE)
+		max_pkt = MAX_MSG_SIZE;
+
+        l_ptr->max_pkt_target = max_pkt;
+	if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
+		l_ptr->max_pkt = l_ptr->max_pkt_target;
+	else 
+		l_ptr->max_pkt = MAX_PKT_DEFAULT;
+
+        l_ptr->max_pkt_probes = 0;
+}
+
+static inline u32 link_next_sent(struct link *l_ptr)
+{
+	if (l_ptr->next_out)
+		return msg_seqno(buf_msg(l_ptr->next_out));
+	return mod(l_ptr->next_out_no);
+}
+
+static inline u32 link_last_sent(struct link *l_ptr)
+{
+	return mod(link_next_sent(l_ptr) - 1);
+}
+
+/*
+ *  Simple non-inlined link routines (i.e. referenced outside this file)
+ */
+
+int link_is_up(struct link *l_ptr)
+{
+	if (!l_ptr)
+		return 0;
+	return (link_working_working(l_ptr) || link_working_unknown(l_ptr));
+}
+
+int link_is_active(struct link *l_ptr)
+{
+	return ((l_ptr->owner->active_links[0] == l_ptr) ||
+		(l_ptr->owner->active_links[1] == l_ptr));
+}
+
+/**
+ * link_name_validate - validate & (optionally) deconstruct link name
+ * @name - ptr to link name string
+ * @name_parts - ptr to area for link name components (or NULL if not needed)
+ * 
+ * Returns 1 if link name is valid, otherwise 0.
+ */
+
+static int link_name_validate(const char *name, struct link_name *name_parts)
+{
+	char name_copy[TIPC_MAX_LINK_NAME];
+	char *addr_local;
+	char *if_local;
+	char *addr_peer;
+	char *if_peer;
+	char dummy;
+	u32 z_local, c_local, n_local;
+	u32 z_peer, c_peer, n_peer;
+	u32 if_local_len;
+	u32 if_peer_len;
+
+	/* copy link name & ensure length is OK */
+
+	name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
+	/* need above in case non-Posix strncpy() doesn't pad with nulls */
+	strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
+	if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
+		return 0;
+
+	/* ensure all component parts of link name are present */
+
+	addr_local = name_copy;
+	if ((if_local = strchr(addr_local, ':')) == NULL)
+		return 0;
+	*(if_local++) = 0;
+	if ((addr_peer = strchr(if_local, '-')) == NULL)
+		return 0;
+	*(addr_peer++) = 0;
+	if_local_len = addr_peer - if_local;
+	if ((if_peer = strchr(addr_peer, ':')) == NULL)
+		return 0;
+	*(if_peer++) = 0;
+	if_peer_len = strlen(if_peer) + 1;
+
+	/* validate component parts of link name */
+
+	if ((sscanf(addr_local, "%u.%u.%u%c",
+		    &z_local, &c_local, &n_local, &dummy) != 3) ||
+	    (sscanf(addr_peer, "%u.%u.%u%c",
+		    &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
+	    (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
+	    (z_peer  > 255) || (c_peer  > 4095) || (n_peer  > 4095) ||
+	    (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) || 
+	    (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME) || 
+	    (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
+	    (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
+		return 0;
+
+	/* return link name components, if necessary */
+
+	if (name_parts) {
+		name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
+		strcpy(name_parts->if_local, if_local);
+		name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
+		strcpy(name_parts->if_peer, if_peer);
+	}
+	return 1;
+}
+
+/**
+ * link_timeout - handle expiration of link timer
+ * @l_ptr: pointer to link
+ * 
+ * This routine must not grab "net_lock" to avoid a potential deadlock conflict
+ * with link_delete().  (There is no risk that the node will be deleted by
+ * another thread because link_delete() always cancels the link timer before
+ * node_delete() is called.)
+ */
+
+static void link_timeout(struct link *l_ptr)
+{
+	node_lock(l_ptr->owner);
+
+	/* update counters used in statistical profiling of send traffic */
+
+	l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
+	l_ptr->stats.queue_sz_counts++;
+
+	if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
+		l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
+
+	if (l_ptr->first_out) {
+		struct tipc_msg *msg = buf_msg(l_ptr->first_out);
+		u32 length = msg_size(msg);
+
+		if ((msg_user(msg) == MSG_FRAGMENTER)
+		    && (msg_type(msg) == FIRST_FRAGMENT)) {
+			length = msg_size(msg_get_wrapped(msg));
+		}
+		if (length) {
+			l_ptr->stats.msg_lengths_total += length;
+			l_ptr->stats.msg_length_counts++;
+			if (length <= 64)
+				l_ptr->stats.msg_length_profile[0]++;
+			else if (length <= 256)
+				l_ptr->stats.msg_length_profile[1]++;
+			else if (length <= 1024)
+				l_ptr->stats.msg_length_profile[2]++;
+			else if (length <= 4096)
+				l_ptr->stats.msg_length_profile[3]++;
+			else if (length <= 16384)
+				l_ptr->stats.msg_length_profile[4]++;
+			else if (length <= 32768)
+				l_ptr->stats.msg_length_profile[5]++;
+			else
+				l_ptr->stats.msg_length_profile[6]++;
+		}
+	}
+
+	/* do all other link processing performed on a periodic basis */
+
+	link_check_defragm_bufs(l_ptr);
+
+	link_state_event(l_ptr, TIMEOUT_EVT);
+
+	if (l_ptr->next_out)
+		link_push_queue(l_ptr);
+
+	node_unlock(l_ptr->owner);
+}
+
+static inline void link_set_timer(struct link *l_ptr, u32 time)
+{
+	k_start_timer(&l_ptr->timer, time);
+}
+
+/**
+ * link_create - create a new link
+ * @b_ptr: pointer to associated bearer
+ * @peer: network address of node at other end of link
+ * @media_addr: media address to use when sending messages over link
+ * 
+ * Returns pointer to link.
+ */
+
+struct link *link_create(struct bearer *b_ptr, const u32 peer,
+			 const struct tipc_media_addr *media_addr)
+{
+	struct link *l_ptr;
+	struct tipc_msg *msg;
+	char *if_name;
+
+	l_ptr = (struct link *)kmalloc(sizeof(*l_ptr), GFP_ATOMIC);
+	if (!l_ptr) {
+		warn("Memory squeeze; Failed to create link\n");
+		return NULL;
+	}
+	memset(l_ptr, 0, sizeof(*l_ptr));
+
+	l_ptr->addr = peer;
+	if_name = strchr(b_ptr->publ.name, ':') + 1;
+	sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:",
+		tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
+		tipc_node(tipc_own_addr), 
+		if_name,
+		tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
+		/* note: peer i/f is appended to link name by reset/activate */
+	memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
+	k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
+	list_add_tail(&l_ptr->link_list, &b_ptr->links);
+	l_ptr->checkpoint = 1;
+	l_ptr->b_ptr = b_ptr;
+	link_set_supervision_props(l_ptr, b_ptr->media->tolerance);
+	l_ptr->state = RESET_UNKNOWN;
+
+	l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
+	msg = l_ptr->pmsg;
+	msg_init(msg, LINK_PROTOCOL, RESET_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr);
+	msg_set_size(msg, sizeof(l_ptr->proto_msg));
+	msg_set_session(msg, tipc_random);
+	msg_set_bearer_id(msg, b_ptr->identity);
+	strcpy((char *)msg_data(msg), if_name);
+
+	l_ptr->priority = b_ptr->priority;
+	link_set_queue_limits(l_ptr, b_ptr->media->window);
+
+	link_init_max_pkt(l_ptr);
+
+	l_ptr->next_out_no = 1;
+	INIT_LIST_HEAD(&l_ptr->waiting_ports);
+
+	link_reset_statistics(l_ptr);
+
+	l_ptr->owner = node_attach_link(l_ptr);
+	if (!l_ptr->owner) {
+		kfree(l_ptr);
+		return NULL;
+	}
+
+	if (LINK_LOG_BUF_SIZE) {
+		char *pb = kmalloc(LINK_LOG_BUF_SIZE, GFP_ATOMIC);
+
+		if (!pb) {
+			kfree(l_ptr);
+			warn("Memory squeeze; Failed to create link\n");
+			return NULL;
+		}
+		printbuf_init(&l_ptr->print_buf, pb, LINK_LOG_BUF_SIZE);
+	}
+
+	k_signal((Handler)link_start, (unsigned long)l_ptr);
+
+	dbg("link_create(): tolerance = %u,cont intv = %u, abort_limit = %u\n",
+	    l_ptr->tolerance, l_ptr->continuity_interval, l_ptr->abort_limit);
+	
+	return l_ptr;
+}
+
+/** 
+ * link_delete - delete a link
+ * @l_ptr: pointer to link
+ * 
+ * Note: 'net_lock' is write_locked, bearer is locked.
+ * This routine must not grab the node lock until after link timer cancellation
+ * to avoid a potential deadlock situation.  
+ */
+
+void link_delete(struct link *l_ptr)
+{
+	if (!l_ptr) {
+		err("Attempt to delete non-existent link\n");
+		return;
+	}
+
+	dbg("link_delete()\n");
+
+	k_cancel_timer(&l_ptr->timer);
+	
+	node_lock(l_ptr->owner);
+	link_reset(l_ptr);
+	node_detach_link(l_ptr->owner, l_ptr);
+	link_stop(l_ptr);
+	list_del_init(&l_ptr->link_list);
+	if (LINK_LOG_BUF_SIZE)
+		kfree(l_ptr->print_buf.buf);
+	node_unlock(l_ptr->owner);
+	k_term_timer(&l_ptr->timer);
+	kfree(l_ptr);
+}
+
+void link_start(struct link *l_ptr)
+{
+	dbg("link_start %x\n", l_ptr);
+	link_state_event(l_ptr, STARTING_EVT);
+}
+
+/**
+ * link_schedule_port - schedule port for deferred sending 
+ * @l_ptr: pointer to link
+ * @origport: reference to sending port
+ * @sz: amount of data to be sent
+ * 
+ * Schedules port for renewed sending of messages after link congestion 
+ * has abated.
+ */
+
+static int link_schedule_port(struct link *l_ptr, u32 origport, u32 sz)
+{
+	struct port *p_ptr;
+
+	spin_lock_bh(&port_list_lock);
+	p_ptr = port_lock(origport);
+	if (p_ptr) {
+		if (!p_ptr->wakeup)
+			goto exit;
+		if (!list_empty(&p_ptr->wait_list))
+			goto exit;
+		p_ptr->congested_link = l_ptr;
+		p_ptr->publ.congested = 1;
+		p_ptr->waiting_pkts = 1 + ((sz - 1) / link_max_pkt(l_ptr));
+		list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
+		l_ptr->stats.link_congs++;
+exit:
+		port_unlock(p_ptr);
+	}
+	spin_unlock_bh(&port_list_lock);
+	return -ELINKCONG;
+}
+
+void link_wakeup_ports(struct link *l_ptr, int all)
+{
+	struct port *p_ptr;
+	struct port *temp_p_ptr;
+	int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
+
+	if (all)
+		win = 100000;
+	if (win <= 0)
+		return;
+	if (!spin_trylock_bh(&port_list_lock))
+		return;
+	if (link_congested(l_ptr))
+		goto exit;
+	list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports, 
+				 wait_list) {
+		if (win <= 0)
+			break;
+		list_del_init(&p_ptr->wait_list);
+		p_ptr->congested_link = 0;
+		assert(p_ptr->wakeup);
+		spin_lock_bh(p_ptr->publ.lock);
+		p_ptr->publ.congested = 0;
+		p_ptr->wakeup(&p_ptr->publ);
+		win -= p_ptr->waiting_pkts;
+		spin_unlock_bh(p_ptr->publ.lock);
+	}
+
+exit:
+	spin_unlock_bh(&port_list_lock);
+}
+
+/** 
+ * link_release_outqueue - purge link's outbound message queue
+ * @l_ptr: pointer to link
+ */
+
+static void link_release_outqueue(struct link *l_ptr)
+{
+	struct sk_buff *buf = l_ptr->first_out;
+	struct sk_buff *next;
+
+	while (buf) {
+		next = buf->next;
+		buf_discard(buf);
+		buf = next;
+	}
+	l_ptr->first_out = NULL;
+	l_ptr->out_queue_size = 0;
+}
+
+/**
+ * link_reset_fragments - purge link's inbound message fragments queue
+ * @l_ptr: pointer to link
+ */
+
+void link_reset_fragments(struct link *l_ptr)
+{
+	struct sk_buff *buf = l_ptr->defragm_buf;
+	struct sk_buff *next;
+
+	while (buf) {
+		next = buf->next;
+		buf_discard(buf);
+		buf = next;
+	}
+	l_ptr->defragm_buf = NULL;
+}
+
+/** 
+ * link_stop - purge all inbound and outbound messages associated with link
+ * @l_ptr: pointer to link
+ */
+
+void link_stop(struct link *l_ptr)
+{
+	struct sk_buff *buf;
+	struct sk_buff *next;
+
+	buf = l_ptr->oldest_deferred_in;
+	while (buf) {
+		next = buf->next;
+		buf_discard(buf);
+		buf = next;
+	}
+
+	buf = l_ptr->first_out;
+	while (buf) {
+		next = buf->next;
+		buf_discard(buf);
+		buf = next;
+	}
+
+	link_reset_fragments(l_ptr);
+
+	buf_discard(l_ptr->proto_msg_queue);
+	l_ptr->proto_msg_queue = NULL;
+}
+
+#if 0
+
+/* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
+
+static void link_recv_event(struct link_event *ev)
+{
+	ev->fcn(ev->addr, ev->name, ev->up);
+	kfree(ev);
+}
+
+static void link_send_event(void (*fcn)(u32 a, char *n, int up),
+			    struct link *l_ptr, int up)
+{
+	struct link_event *ev;
+	
+	ev = kmalloc(sizeof(*ev), GFP_ATOMIC);
+	if (!ev) {
+		warn("Link event allocation failure\n");
+		return;
+	}
+	ev->addr = l_ptr->addr;
+	ev->up = up;
+	ev->fcn = fcn;
+	memcpy(ev->name, l_ptr->name, TIPC_MAX_LINK_NAME);
+	k_signal((Handler)link_recv_event, (unsigned long)ev);
+}
+
+#else
+
+#define link_send_event(fcn, l_ptr, up) do { } while (0)
+
+#endif
+
+void link_reset(struct link *l_ptr)
+{
+	struct sk_buff *buf;
+	u32 prev_state = l_ptr->state;
+	u32 checkpoint = l_ptr->next_in_no;
+	
+	msg_set_session(l_ptr->pmsg, msg_session(l_ptr->pmsg) + 1);
+
+        /* Link is down, accept any session: */
+	l_ptr->peer_session = 0;
+
+        /* Prepare for max packet size negotiation */
+	link_init_max_pkt(l_ptr);
+	
+	l_ptr->state = RESET_UNKNOWN;
+	dbg_link_state("Resetting Link\n");
+
+	if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
+		return;
+
+	node_link_down(l_ptr->owner, l_ptr);
+	bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
+#if 0
+	tipc_printf(CONS, "\nReset link <%s>\n", l_ptr->name);
+	dbg_link_dump();
+#endif
+	if (node_has_active_links(l_ptr->owner) &&
+	    l_ptr->owner->permit_changeover) {
+		l_ptr->reset_checkpoint = checkpoint;
+		l_ptr->exp_msg_count = START_CHANGEOVER;
+	}
+
+	/* Clean up all queues: */
+
+	link_release_outqueue(l_ptr);
+	buf_discard(l_ptr->proto_msg_queue);
+	l_ptr->proto_msg_queue = NULL;
+	buf = l_ptr->oldest_deferred_in;
+	while (buf) {
+		struct sk_buff *next = buf->next;
+		buf_discard(buf);
+		buf = next;
+	}
+	if (!list_empty(&l_ptr->waiting_ports))
+		link_wakeup_ports(l_ptr, 1);
+
+	l_ptr->retransm_queue_head = 0;
+	l_ptr->retransm_queue_size = 0;
+	l_ptr->last_out = NULL;
+	l_ptr->first_out = NULL;
+	l_ptr->next_out = NULL;
+	l_ptr->unacked_window = 0;
+	l_ptr->checkpoint = 1;
+	l_ptr->next_out_no = 1;
+	l_ptr->deferred_inqueue_sz = 0;
+	l_ptr->oldest_deferred_in = NULL;
+	l_ptr->newest_deferred_in = NULL;
+	l_ptr->fsm_msg_cnt = 0;
+	l_ptr->stale_count = 0;
+	link_reset_statistics(l_ptr);
+
+	link_send_event(cfg_link_event, l_ptr, 0);
+	if (!in_own_cluster(l_ptr->addr))
+		link_send_event(disc_link_event, l_ptr, 0);
+}
+
+
+static void link_activate(struct link *l_ptr)
+{
+	l_ptr->next_in_no = 1;
+	node_link_up(l_ptr->owner, l_ptr);
+	bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
+	link_send_event(cfg_link_event, l_ptr, 1);
+	if (!in_own_cluster(l_ptr->addr))
+		link_send_event(disc_link_event, l_ptr, 1);
+}
+
+/**
+ * link_state_event - link finite state machine
+ * @l_ptr: pointer to link
+ * @event: state machine event to process
+ */
+
+static void link_state_event(struct link *l_ptr, unsigned event)
+{
+	struct link *other; 
+	u32 cont_intv = l_ptr->continuity_interval;
+
+	if (!l_ptr->started && (event != STARTING_EVT))
+		return;		/* Not yet. */
+
+	if (link_blocked(l_ptr)) {
+		if (event == TIMEOUT_EVT) {
+			link_set_timer(l_ptr, cont_intv);
+		}
+		return;	  /* Changeover going on */
+	}
+	dbg_link("STATE_EV: <%s> ", l_ptr->name);
+
+	switch (l_ptr->state) {
+	case WORKING_WORKING:
+		dbg_link("WW/");
+		switch (event) {
+		case TRAFFIC_MSG_EVT:
+			dbg_link("TRF-");
+			/* fall through */
+		case ACTIVATE_MSG:
+			dbg_link("ACT\n");
+			break;
+		case TIMEOUT_EVT:
+			dbg_link("TIM ");
+			if (l_ptr->next_in_no != l_ptr->checkpoint) {
+				l_ptr->checkpoint = l_ptr->next_in_no;
+				if (bclink_acks_missing(l_ptr->owner)) {
+					link_send_proto_msg(l_ptr, STATE_MSG, 
+							    0, 0, 0, 0, 0);
+					l_ptr->fsm_msg_cnt++;
+				} else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
+					link_send_proto_msg(l_ptr, STATE_MSG, 
+							    1, 0, 0, 0, 0);
+					l_ptr->fsm_msg_cnt++;
+				}
+				link_set_timer(l_ptr, cont_intv);
+				break;
+			}
+			dbg_link(" -> WU\n");
+			l_ptr->state = WORKING_UNKNOWN;
+			l_ptr->fsm_msg_cnt = 0;
+			link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
+			l_ptr->fsm_msg_cnt++;
+			link_set_timer(l_ptr, cont_intv / 4);
+			break;
+		case RESET_MSG:
+			dbg_link("RES -> RR\n");
+			link_reset(l_ptr);
+			l_ptr->state = RESET_RESET;
+			l_ptr->fsm_msg_cnt = 0;
+			link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
+			l_ptr->fsm_msg_cnt++;
+			link_set_timer(l_ptr, cont_intv);
+			break;
+		default:
+			err("Unknown link event %u in WW state\n", event);
+		}
+		break;
+	case WORKING_UNKNOWN:
+		dbg_link("WU/");
+		switch (event) {
+		case TRAFFIC_MSG_EVT:
+			dbg_link("TRF-");
+		case ACTIVATE_MSG:
+			dbg_link("ACT -> WW\n");
+			l_ptr->state = WORKING_WORKING;
+			l_ptr->fsm_msg_cnt = 0;
+			link_set_timer(l_ptr, cont_intv);
+			break;
+		case RESET_MSG:
+			dbg_link("RES -> RR\n");
+			link_reset(l_ptr);
+			l_ptr->state = RESET_RESET;
+			l_ptr->fsm_msg_cnt = 0;
+			link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
+			l_ptr->fsm_msg_cnt++;
+			link_set_timer(l_ptr, cont_intv);
+			break;
+		case TIMEOUT_EVT:
+			dbg_link("TIM ");
+			if (l_ptr->next_in_no != l_ptr->checkpoint) {
+				dbg_link("-> WW \n");
+				l_ptr->state = WORKING_WORKING;
+				l_ptr->fsm_msg_cnt = 0;
+				l_ptr->checkpoint = l_ptr->next_in_no;
+				if (bclink_acks_missing(l_ptr->owner)) {
+					link_send_proto_msg(l_ptr, STATE_MSG,
+							    0, 0, 0, 0, 0);
+					l_ptr->fsm_msg_cnt++;
+				}
+				link_set_timer(l_ptr, cont_intv);
+			} else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
+				dbg_link("Probing %u/%u,timer = %u ms)\n",
+					 l_ptr->fsm_msg_cnt, l_ptr->abort_limit,
+					 cont_intv / 4);
+				link_send_proto_msg(l_ptr, STATE_MSG, 
+						    1, 0, 0, 0, 0);
+				l_ptr->fsm_msg_cnt++;
+				link_set_timer(l_ptr, cont_intv / 4);
+			} else {	/* Link has failed */
+				dbg_link("-> RU (%u probes unanswered)\n",
+					 l_ptr->fsm_msg_cnt);
+				link_reset(l_ptr);
+				l_ptr->state = RESET_UNKNOWN;
+				l_ptr->fsm_msg_cnt = 0;
+				link_send_proto_msg(l_ptr, RESET_MSG,
+						    0, 0, 0, 0, 0);
+				l_ptr->fsm_msg_cnt++;
+				link_set_timer(l_ptr, cont_intv);
+			}
+			break;
+		default:
+			err("Unknown link event %u in WU state\n", event);
+		}
+		break;
+	case RESET_UNKNOWN:
+		dbg_link("RU/");
+		switch (event) {
+		case TRAFFIC_MSG_EVT:
+			dbg_link("TRF-\n");
+			break;
+		case ACTIVATE_MSG:
+			other = l_ptr->owner->active_links[0];
+			if (other && link_working_unknown(other)) {
+				dbg_link("ACT\n");
+				break;
+			}
+			dbg_link("ACT -> WW\n");
+			l_ptr->state = WORKING_WORKING;
+			l_ptr->fsm_msg_cnt = 0;
+			link_activate(l_ptr);
+			link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
+			l_ptr->fsm_msg_cnt++;
+			link_set_timer(l_ptr, cont_intv);
+			break;
+		case RESET_MSG:
+			dbg_link("RES \n");
+			dbg_link(" -> RR\n");
+			l_ptr->state = RESET_RESET;
+			l_ptr->fsm_msg_cnt = 0;
+			link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
+			l_ptr->fsm_msg_cnt++;
+			link_set_timer(l_ptr, cont_intv);
+			break;
+		case STARTING_EVT:
+			dbg_link("START-");
+			l_ptr->started = 1;
+			/* fall through */
+		case TIMEOUT_EVT:
+			dbg_link("TIM \n");
+			link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
+			l_ptr->fsm_msg_cnt++;
+			link_set_timer(l_ptr, cont_intv);
+			break;
+		default:
+			err("Unknown link event %u in RU state\n", event);
+		}
+		break;
+	case RESET_RESET:
+		dbg_link("RR/ ");
+		switch (event) {
+		case TRAFFIC_MSG_EVT:
+			dbg_link("TRF-");
+			/* fall through */
+		case ACTIVATE_MSG:
+			other = l_ptr->owner->active_links[0];
+			if (other && link_working_unknown(other)) {
+				dbg_link("ACT\n");
+				break;
+			}
+			dbg_link("ACT -> WW\n");
+			l_ptr->state = WORKING_WORKING;
+			l_ptr->fsm_msg_cnt = 0;
+			link_activate(l_ptr);
+			link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
+			l_ptr->fsm_msg_cnt++;
+			link_set_timer(l_ptr, cont_intv);
+			break;
+		case RESET_MSG:
+			dbg_link("RES\n");
+			break;
+		case TIMEOUT_EVT:
+			dbg_link("TIM\n");
+			link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
+			l_ptr->fsm_msg_cnt++;
+			link_set_timer(l_ptr, cont_intv);
+			dbg_link("fsm_msg_cnt %u\n", l_ptr->fsm_msg_cnt);
+			break;
+		default:
+			err("Unknown link event %u in RR state\n", event);
+		}
+		break;
+	default:
+		err("Unknown link state %u/%u\n", l_ptr->state, event);
+	}
+}
+
+/*
+ * link_bundle_buf(): Append contents of a buffer to
+ * the tail of an existing one. 
+ */
+
+static int link_bundle_buf(struct link *l_ptr,
+			   struct sk_buff *bundler, 
+			   struct sk_buff *buf)
+{
+	struct tipc_msg *bundler_msg = buf_msg(bundler);
+	struct tipc_msg *msg = buf_msg(buf);
+	u32 size = msg_size(msg);
+	u32 to_pos = align(msg_size(bundler_msg));
+	u32 rest = link_max_pkt(l_ptr) - to_pos;
+
+	if (msg_user(bundler_msg) != MSG_BUNDLER)
+		return 0;
+	if (msg_type(bundler_msg) != OPEN_MSG)
+		return 0;
+	if (rest < align(size))
+		return 0;
+
+	skb_put(bundler, (to_pos - msg_size(bundler_msg)) + size);
+	memcpy(bundler->data + to_pos, buf->data, size);
+	msg_set_size(bundler_msg, to_pos + size);
+	msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
+	dbg("Packed msg # %u(%u octets) into pos %u in buf(#%u)\n",
+	    msg_msgcnt(bundler_msg), size, to_pos, msg_seqno(bundler_msg));
+	msg_dbg(msg, "PACKD:");
+	buf_discard(buf);
+	l_ptr->stats.sent_bundled++;
+	return 1;
+}
+
+static inline void link_add_to_outqueue(struct link *l_ptr, 
+					struct sk_buff *buf, 
+					struct tipc_msg *msg)
+{
+	u32 ack = mod(l_ptr->next_in_no - 1);
+	u32 seqno = mod(l_ptr->next_out_no++);
+
+	msg_set_word(msg, 2, ((ack << 16) | seqno));
+	msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
+	buf->next = NULL;
+	if (l_ptr->first_out) {
+		l_ptr->last_out->next = buf;
+		l_ptr->last_out = buf;
+	} else
+		l_ptr->first_out = l_ptr->last_out = buf;
+	l_ptr->out_queue_size++;
+}
+
+/* 
+ * link_send_buf() is the 'full path' for messages, called from 
+ * inside TIPC when the 'fast path' in tipc_send_buf
+ * has failed, and from link_send()
+ */
+
+int link_send_buf(struct link *l_ptr, struct sk_buff *buf)
+{
+	struct tipc_msg *msg = buf_msg(buf);
+	u32 size = msg_size(msg);
+	u32 dsz = msg_data_sz(msg);
+	u32 queue_size = l_ptr->out_queue_size;
+	u32 imp = msg_tot_importance(msg);
+	u32 queue_limit = l_ptr->queue_limit[imp];
+	u32 max_packet = link_max_pkt(l_ptr);
+
+	msg_set_prevnode(msg, tipc_own_addr);	/* If routed message */
+
+	/* Match msg importance against queue limits: */
+
+	if (unlikely(queue_size >= queue_limit)) {
+		if (imp <= TIPC_CRITICAL_IMPORTANCE) {
+			return link_schedule_port(l_ptr, msg_origport(msg),
+						  size);
+		}
+		msg_dbg(msg, "TIPC: Congestion, throwing away\n");
+		buf_discard(buf);
+		if (imp > CONN_MANAGER) {
+			warn("Resetting <%s>, send queue full", l_ptr->name);
+			link_reset(l_ptr);
+		}
+		return dsz;
+	}
+
+	/* Fragmentation needed ? */
+
+	if (size > max_packet)
+		return link_send_long_buf(l_ptr, buf);
+
+	/* Packet can be queued or sent: */
+
+	if (queue_size > l_ptr->stats.max_queue_sz)
+		l_ptr->stats.max_queue_sz = queue_size;
+
+	if (likely(!bearer_congested(l_ptr->b_ptr, l_ptr) && 
+		   !link_congested(l_ptr))) {
+		link_add_to_outqueue(l_ptr, buf, msg);
+
+		if (likely(bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
+			l_ptr->unacked_window = 0;
+		} else {
+			bearer_schedule(l_ptr->b_ptr, l_ptr);
+			l_ptr->stats.bearer_congs++;
+			l_ptr->next_out = buf;
+		}
+		return dsz;
+	}
+	/* Congestion: can message be bundled ?: */
+
+	if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
+	    (msg_user(msg) != MSG_FRAGMENTER)) {
+
+		/* Try adding message to an existing bundle */
+
+		if (l_ptr->next_out && 
+		    link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
+			bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
+			return dsz;
+		}
+
+		/* Try creating a new bundle */
+
+		if (size <= max_packet * 2 / 3) {
+			struct sk_buff *bundler = buf_acquire(max_packet);
+			struct tipc_msg bundler_hdr;
+
+			if (bundler) {
+				msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
+					 TIPC_OK, INT_H_SIZE, l_ptr->addr);
+				memcpy(bundler->data, (unchar *)&bundler_hdr, 
+				       INT_H_SIZE);
+				skb_trim(bundler, INT_H_SIZE);
+				link_bundle_buf(l_ptr, bundler, buf);
+				buf = bundler;
+				msg = buf_msg(buf);
+				l_ptr->stats.sent_bundles++;
+			}
+		}
+	}
+	if (!l_ptr->next_out)
+		l_ptr->next_out = buf;
+	link_add_to_outqueue(l_ptr, buf, msg);
+	bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
+	return dsz;
+}
+
+/* 
+ * link_send(): same as link_send_buf(), but the link to use has 
+ * not been selected yet, and the the owner node is not locked
+ * Called by TIPC internal users, e.g. the name distributor
+ */
+
+int link_send(struct sk_buff *buf, u32 dest, u32 selector)
+{
+	struct link *l_ptr;
+	struct node *n_ptr;
+	int res = -ELINKCONG;
+
+	read_lock_bh(&net_lock);
+	n_ptr = node_select(dest, selector);
+	if (n_ptr) {
+		node_lock(n_ptr);
+		l_ptr = n_ptr->active_links[selector & 1];
+		dbg("link_send: found link %x for dest %x\n", l_ptr, dest);
+		if (l_ptr) {
+			res = link_send_buf(l_ptr, buf);
+		}
+		node_unlock(n_ptr);
+	} else {
+		dbg("Attempt to send msg to unknown node:\n");
+		msg_dbg(buf_msg(buf),">>>");
+		buf_discard(buf);
+	}
+	read_unlock_bh(&net_lock);
+	return res;
+}
+
+/* 
+ * link_send_buf_fast: Entry for data messages where the 
+ * destination link is known and the header is complete,
+ * inclusive total message length. Very time critical.
+ * Link is locked. Returns user data length.
+ */
+
+static inline int link_send_buf_fast(struct link *l_ptr, struct sk_buff *buf,
+				     u32 *used_max_pkt)
+{
+	struct tipc_msg *msg = buf_msg(buf);
+	int res = msg_data_sz(msg);
+
+	if (likely(!link_congested(l_ptr))) {
+		if (likely(msg_size(msg) <= link_max_pkt(l_ptr))) {
+			if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
+				link_add_to_outqueue(l_ptr, buf, msg);
+				if (likely(bearer_send(l_ptr->b_ptr, buf,
+						       &l_ptr->media_addr))) {
+					l_ptr->unacked_window = 0;
+					msg_dbg(msg,"SENT_FAST:");
+					return res;
+				}
+				dbg("failed sent fast...\n");
+				bearer_schedule(l_ptr->b_ptr, l_ptr);
+				l_ptr->stats.bearer_congs++;
+				l_ptr->next_out = buf;
+				return res;
+			}
+		}
+		else
+			*used_max_pkt = link_max_pkt(l_ptr);
+	}
+	return link_send_buf(l_ptr, buf);  /* All other cases */
+}
+
+/* 
+ * tipc_send_buf_fast: Entry for data messages where the 
+ * destination node is known and the header is complete,
+ * inclusive total message length.
+ * Returns user data length.
+ */
+int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
+{
+	struct link *l_ptr;
+	struct node *n_ptr;
+	int res;
+	u32 selector = msg_origport(buf_msg(buf)) & 1;
+	u32 dummy;
+
+	if (destnode == tipc_own_addr)
+		return port_recv_msg(buf);
+
+	read_lock_bh(&net_lock);
+	n_ptr = node_select(destnode, selector);
+	if (likely(n_ptr)) {
+		node_lock(n_ptr);
+		l_ptr = n_ptr->active_links[selector];
+		dbg("send_fast: buf %x selected %x, destnode = %x\n",
+		    buf, l_ptr, destnode);
+		if (likely(l_ptr)) {
+			res = link_send_buf_fast(l_ptr, buf, &dummy);
+			node_unlock(n_ptr);
+			read_unlock_bh(&net_lock);
+			return res;
+		}
+		node_unlock(n_ptr);
+	}
+	read_unlock_bh(&net_lock);
+	res = msg_data_sz(buf_msg(buf));
+	tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
+	return res;
+}
+
+
+/* 
+ * link_send_sections_fast: Entry for messages where the 
+ * destination processor is known and the header is complete,
+ * except for total message length. 
+ * Returns user data length or errno.
+ */
+int link_send_sections_fast(struct port *sender, 
+			    struct iovec const *msg_sect,
+			    const u32 num_sect, 
+			    u32 destaddr)
+{
+	struct tipc_msg *hdr = &sender->publ.phdr;
+	struct link *l_ptr;
+	struct sk_buff *buf;
+	struct node *node;
+	int res;
+	u32 selector = msg_origport(hdr) & 1;
+
+	assert(destaddr != tipc_own_addr);
+
+again:
+	/*
+	 * Try building message using port's max_pkt hint.
+	 * (Must not hold any locks while building message.)
+	 */
+
+	res = msg_build(hdr, msg_sect, num_sect, sender->max_pkt,
+			!sender->user_port, &buf);
+
+	read_lock_bh(&net_lock);
+	node = node_select(destaddr, selector);
+	if (likely(node)) {
+		node_lock(node);
+		l_ptr = node->active_links[selector];
+		if (likely(l_ptr)) {
+			if (likely(buf)) {
+				res = link_send_buf_fast(l_ptr, buf,
+							 &sender->max_pkt);
+				if (unlikely(res < 0))
+					buf_discard(buf);
+exit:
+				node_unlock(node);
+				read_unlock_bh(&net_lock);
+				return res;
+			}
+
+			/* Exit if build request was invalid */
+
+			if (unlikely(res < 0))
+				goto exit;
+
+			/* Exit if link (or bearer) is congested */
+
+			if (link_congested(l_ptr) || 
+			    !list_empty(&l_ptr->b_ptr->cong_links)) {
+				res = link_schedule_port(l_ptr,
+							 sender->publ.ref, res);
+				goto exit;
+			}
+
+			/* 
+			 * Message size exceeds max_pkt hint; update hint,
+			 * then re-try fast path or fragment the message
+			 */
+
+			sender->max_pkt = link_max_pkt(l_ptr);
+			node_unlock(node);
+			read_unlock_bh(&net_lock);
+
+
+			if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
+				goto again;
+
+			return link_send_sections_long(sender, msg_sect,
+						       num_sect, destaddr);
+		}
+		node_unlock(node);
+	}
+	read_unlock_bh(&net_lock);
+
+	/* Couldn't find a link to the destination node */
+
+	if (buf)
+		return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
+	if (res >= 0)
+		return port_reject_sections(sender, hdr, msg_sect, num_sect,
+					    TIPC_ERR_NO_NODE);
+	return res;
+}
+
+/* 
+ * link_send_sections_long(): Entry for long messages where the 
+ * destination node is known and the header is complete,
+ * inclusive total message length. 
+ * Link and bearer congestion status have been checked to be ok,
+ * and are ignored if they change.
+ *
+ * Note that fragments do not use the full link MTU so that they won't have
+ * to undergo refragmentation if link changeover causes them to be sent
+ * over another link with an additional tunnel header added as prefix.
+ * (Refragmentation will still occur if the other link has a smaller MTU.)
+ *
+ * Returns user data length or errno.
+ */
+static int link_send_sections_long(struct port *sender,
+				   struct iovec const *msg_sect,
+				   u32 num_sect,
+				   u32 destaddr)
+{
+	struct link *l_ptr;
+	struct node *node;
+	struct tipc_msg *hdr = &sender->publ.phdr;
+	u32 dsz = msg_data_sz(hdr);
+	u32 max_pkt,fragm_sz,rest;
+	struct tipc_msg fragm_hdr;
+	struct sk_buff *buf,*buf_chain,*prev;
+	u32 fragm_crs,fragm_rest,hsz,sect_rest;
+	const unchar *sect_crs;
+	int curr_sect;
+	u32 fragm_no;
+
+again:
+	fragm_no = 1;
+	max_pkt = sender->max_pkt - INT_H_SIZE;  
+		/* leave room for tunnel header in case of link changeover */
+	fragm_sz = max_pkt - INT_H_SIZE; 
+		/* leave room for fragmentation header in each fragment */
+	rest = dsz;
+	fragm_crs = 0;
+	fragm_rest = 0;
+	sect_rest = 0;
+	sect_crs = 0;
+	curr_sect = -1;
+
+	/* Prepare reusable fragment header: */
+
+	msg_dbg(hdr, ">FRAGMENTING>");
+	msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
+		 TIPC_OK, INT_H_SIZE, msg_destnode(hdr));
+	msg_set_link_selector(&fragm_hdr, sender->publ.ref);
+	msg_set_size(&fragm_hdr, max_pkt);
+	msg_set_fragm_no(&fragm_hdr, 1);
+
+	/* Prepare header of first fragment: */
+
+	buf_chain = buf = buf_acquire(max_pkt);
+	if (!buf)
+		return -ENOMEM;
+	buf->next = NULL;
+	memcpy(buf->data, (unchar *)&fragm_hdr, INT_H_SIZE);
+	hsz = msg_hdr_sz(hdr);
+	memcpy(buf->data + INT_H_SIZE, (unchar *)hdr, hsz);
+	msg_dbg(buf_msg(buf), ">BUILD>");
+
+	/* Chop up message: */
+
+	fragm_crs = INT_H_SIZE + hsz;
+	fragm_rest = fragm_sz - hsz;
+
+	do {		/* For all sections */
+		u32 sz;
+
+		if (!sect_rest) {
+			sect_rest = msg_sect[++curr_sect].iov_len;
+			sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
+		}
+
+		if (sect_rest < fragm_rest)
+			sz = sect_rest;
+		else
+			sz = fragm_rest;
+
+		if (likely(!sender->user_port)) {
+			if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
+error:
+				for (; buf_chain; buf_chain = buf) {
+					buf = buf_chain->next;
+					buf_discard(buf_chain);
+				}
+				return -EFAULT;
+			}
+		} else
+			memcpy(buf->data + fragm_crs, sect_crs, sz);
+
+		sect_crs += sz;
+		sect_rest -= sz;
+		fragm_crs += sz;
+		fragm_rest -= sz;
+		rest -= sz;
+
+		if (!fragm_rest && rest) {
+
+			/* Initiate new fragment: */
+			if (rest <= fragm_sz) {
+				fragm_sz = rest;
+				msg_set_type(&fragm_hdr,LAST_FRAGMENT);
+			} else {
+				msg_set_type(&fragm_hdr, FRAGMENT);
+			}
+			msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
+			msg_set_fragm_no(&fragm_hdr, ++fragm_no);
+			prev = buf;
+			buf = buf_acquire(fragm_sz + INT_H_SIZE);
+			if (!buf)
+				goto error;
+
+			buf->next = NULL;                                
+			prev->next = buf;
+			memcpy(buf->data, (unchar *)&fragm_hdr, INT_H_SIZE);
+			fragm_crs = INT_H_SIZE;
+			fragm_rest = fragm_sz;
+			msg_dbg(buf_msg(buf),"  >BUILD>");
+		}
+	}
+	while (rest > 0);
+
+	/* 
+	 * Now we have a buffer chain. Select a link and check
+	 * that packet size is still OK
+	 */
+	node = node_select(destaddr, sender->publ.ref & 1);
+	if (likely(node)) {
+		node_lock(node);
+		l_ptr = node->active_links[sender->publ.ref & 1];
+		if (!l_ptr) {
+			node_unlock(node);
+			goto reject;
+		}
+		if (link_max_pkt(l_ptr) < max_pkt) {
+			sender->max_pkt = link_max_pkt(l_ptr);
+			node_unlock(node);
+			for (; buf_chain; buf_chain = buf) {
+				buf = buf_chain->next;
+				buf_discard(buf_chain);
+			}
+			goto again;
+		}
+	} else {
+reject:
+		for (; buf_chain; buf_chain = buf) {
+			buf = buf_chain->next;
+			buf_discard(buf_chain);
+		}
+		return port_reject_sections(sender, hdr, msg_sect, num_sect,
+					    TIPC_ERR_NO_NODE);
+	}
+
+	/* Append whole chain to send queue: */
+
+	buf = buf_chain;
+	l_ptr->long_msg_seq_no = mod(l_ptr->long_msg_seq_no + 1);
+	if (!l_ptr->next_out)
+		l_ptr->next_out = buf_chain;
+	l_ptr->stats.sent_fragmented++;
+	while (buf) {
+		struct sk_buff *next = buf->next;
+		struct tipc_msg *msg = buf_msg(buf);
+
+		l_ptr->stats.sent_fragments++;
+		msg_set_long_msgno(msg, l_ptr->long_msg_seq_no);
+		link_add_to_outqueue(l_ptr, buf, msg);
+		msg_dbg(msg, ">ADD>");
+		buf = next;
+	}
+
+	/* Send it, if possible: */
+
+	link_push_queue(l_ptr);
+	node_unlock(node);
+	return dsz;
+}
+
+/* 
+ * link_push_packet: Push one unsent packet to the media
+ */
+u32 link_push_packet(struct link *l_ptr)
+{
+	struct sk_buff *buf = l_ptr->first_out;
+	u32 r_q_size = l_ptr->retransm_queue_size;
+	u32 r_q_head = l_ptr->retransm_queue_head;
+
+	/* Step to position where retransmission failed, if any,    */
+	/* consider that buffers may have been released in meantime */
+
+	if (r_q_size && buf) {
+		u32 last = lesser(mod(r_q_head + r_q_size), 
+				  link_last_sent(l_ptr));
+		u32 first = msg_seqno(buf_msg(buf));
+
+		while (buf && less(first, r_q_head)) {
+			first = mod(first + 1);
+			buf = buf->next;
+		}
+		l_ptr->retransm_queue_head = r_q_head = first;
+		l_ptr->retransm_queue_size = r_q_size = mod(last - first);
+	}
+
+	/* Continue retransmission now, if there is anything: */
+
+	if (r_q_size && buf && !skb_cloned(buf)) {
+		msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
+		msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in); 
+		if (bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
+			msg_dbg(buf_msg(buf), ">DEF-RETR>");
+			l_ptr->retransm_queue_head = mod(++r_q_head);
+			l_ptr->retransm_queue_size = --r_q_size;
+			l_ptr->stats.retransmitted++;
+			return TIPC_OK;
+		} else {
+			l_ptr->stats.bearer_congs++;
+			msg_dbg(buf_msg(buf), "|>DEF-RETR>");
+			return PUSH_FAILED;
+		}
+	}
+
+	/* Send deferred protocol message, if any: */
+
+	buf = l_ptr->proto_msg_queue;
+	if (buf) {
+		msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
+		msg_set_bcast_ack(buf_msg(buf),l_ptr->owner->bclink.last_in); 
+		if (bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
+			msg_dbg(buf_msg(buf), ">DEF-PROT>");
+			l_ptr->unacked_window = 0;
+			buf_discard(buf);
+			l_ptr->proto_msg_queue = 0;
+			return TIPC_OK;
+		} else {
+			msg_dbg(buf_msg(buf), "|>DEF-PROT>");
+			l_ptr->stats.bearer_congs++;
+			return PUSH_FAILED;
+		}
+	}
+
+	/* Send one deferred data message, if send window not full: */
+
+	buf = l_ptr->next_out;
+	if (buf) {
+		struct tipc_msg *msg = buf_msg(buf);
+		u32 next = msg_seqno(msg);
+		u32 first = msg_seqno(buf_msg(l_ptr->first_out));
+
+		if (mod(next - first) < l_ptr->queue_limit[0]) {
+			msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
+			msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); 
+			if (bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
+				if (msg_user(msg) == MSG_BUNDLER)
+					msg_set_type(msg, CLOSED_MSG);
+				msg_dbg(msg, ">PUSH-DATA>");
+				l_ptr->next_out = buf->next;
+				return TIPC_OK;
+			} else {
+				msg_dbg(msg, "|PUSH-DATA|");
+				l_ptr->stats.bearer_congs++;
+				return PUSH_FAILED;
+			}
+		}
+	}
+	return PUSH_FINISHED;
+}
+
+/*
+ * push_queue(): push out the unsent messages of a link where
+ *               congestion has abated. Node is locked
+ */
+void link_push_queue(struct link *l_ptr)
+{
+	u32 res;
+
+	if (bearer_congested(l_ptr->b_ptr, l_ptr))
+		return;
+
+	do {
+		res = link_push_packet(l_ptr);
+	}
+	while (res == TIPC_OK);
+	if (res == PUSH_FAILED)
+		bearer_schedule(l_ptr->b_ptr, l_ptr);
+}
+
+void link_retransmit(struct link *l_ptr, struct sk_buff *buf, 
+		     u32 retransmits)
+{
+	struct tipc_msg *msg;
+
+	dbg("Retransmitting %u in link %x\n", retransmits, l_ptr);
+
+	if (bearer_congested(l_ptr->b_ptr, l_ptr) && buf && !skb_cloned(buf)) {
+		msg_dbg(buf_msg(buf), ">NO_RETR->BCONG>");
+		dbg_print_link(l_ptr, "   ");
+		l_ptr->retransm_queue_head = msg_seqno(buf_msg(buf));
+		l_ptr->retransm_queue_size = retransmits;
+		return;
+	}
+	while (retransmits && (buf != l_ptr->next_out) && buf && !skb_cloned(buf)) {
+		msg = buf_msg(buf);
+		msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
+		msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); 
+		if (bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
+                        /* Catch if retransmissions fail repeatedly: */
+                        if (l_ptr->last_retransmitted == msg_seqno(msg)) {
+                                if (++l_ptr->stale_count > 100) {
+                                        msg_print(CONS, buf_msg(buf), ">RETR>");
+                                        info("...Retransmitted %u times\n",
+					     l_ptr->stale_count);
+                                        link_print(l_ptr, CONS, "Resetting Link\n");;
+                                        link_reset(l_ptr);
+                                        break;
+                                }
+                        } else {
+                                l_ptr->stale_count = 0;
+                        }
+                        l_ptr->last_retransmitted = msg_seqno(msg);
+
+			msg_dbg(buf_msg(buf), ">RETR>");
+			buf = buf->next;
+			retransmits--;
+			l_ptr->stats.retransmitted++;
+		} else {
+			bearer_schedule(l_ptr->b_ptr, l_ptr);
+			l_ptr->stats.bearer_congs++;
+			l_ptr->retransm_queue_head = msg_seqno(buf_msg(buf));
+			l_ptr->retransm_queue_size = retransmits;
+			return;
+		}
+	}
+	l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
+}
+
+/* 
+ * link_recv_non_seq: Receive packets which are outside
+ *                    the link sequence flow
+ */
+
+static void link_recv_non_seq(struct sk_buff *buf)
+{
+	struct tipc_msg *msg = buf_msg(buf);
+
+	if (msg_user(msg) ==  LINK_CONFIG)
+		disc_recv_msg(buf);
+	else
+		bclink_recv_pkt(buf);
+}
+
+/** 
+ * link_insert_deferred_queue - insert deferred messages back into receive chain
+ */
+
+static struct sk_buff *link_insert_deferred_queue(struct link *l_ptr, 
+						  struct sk_buff *buf)
+{
+	u32 seq_no;
+
+	if (l_ptr->oldest_deferred_in == NULL)
+		return buf;
+
+	seq_no = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
+	if (seq_no == mod(l_ptr->next_in_no)) {
+		l_ptr->newest_deferred_in->next = buf;
+		buf = l_ptr->oldest_deferred_in;
+		l_ptr->oldest_deferred_in = NULL;
+		l_ptr->deferred_inqueue_sz = 0;
+	}
+	return buf;
+}
+
+void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr)
+{
+	read_lock_bh(&net_lock);
+	while (head) {
+		struct bearer *b_ptr;
+		struct node *n_ptr;
+		struct link *l_ptr;
+		struct sk_buff *crs;
+		struct sk_buff *buf = head;
+		struct tipc_msg *msg = buf_msg(buf);
+		u32 seq_no = msg_seqno(msg);
+		u32 ackd = msg_ack(msg);
+		u32 released = 0;
+		int type;
+
+		b_ptr = (struct bearer *)tb_ptr;
+		TIPC_SKB_CB(buf)->handle = b_ptr;
+
+		head = head->next;
+		if (unlikely(msg_version(msg) != TIPC_VERSION))
+			goto cont;
+#if 0
+		if (msg_user(msg) != LINK_PROTOCOL)
+#endif
+			msg_dbg(msg,"<REC<");
+
+		if (unlikely(msg_non_seq(msg))) {
+			link_recv_non_seq(buf);
+			continue;
+		}
+		n_ptr = node_find(msg_prevnode(msg));
+		if (unlikely(!n_ptr))
+			goto cont;
+
+		node_lock(n_ptr);
+		l_ptr = n_ptr->links[b_ptr->identity];
+		if (unlikely(!l_ptr)) {
+			node_unlock(n_ptr);
+			goto cont;
+		}
+		/* 
+		 * Release acked messages 
+		 */
+		if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) {
+			if (node_is_up(n_ptr) && n_ptr->bclink.supported)
+				bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
+		}
+
+		crs = l_ptr->first_out;
+		while ((crs != l_ptr->next_out) && 
+		       less_eq(msg_seqno(buf_msg(crs)), ackd)) {
+			struct sk_buff *next = crs->next;
+
+			buf_discard(crs);
+			crs = next;
+			released++;
+		}
+		if (released) {
+			l_ptr->first_out = crs;
+			l_ptr->out_queue_size -= released;
+		}
+		if (unlikely(l_ptr->next_out))
+			link_push_queue(l_ptr);
+		if (unlikely(!list_empty(&l_ptr->waiting_ports)))
+			link_wakeup_ports(l_ptr, 0);
+		if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
+			l_ptr->stats.sent_acks++;
+			link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
+		}
+
+protocol_check:
+		if (likely(link_working_working(l_ptr))) {
+			if (likely(seq_no == mod(l_ptr->next_in_no))) {
+				l_ptr->next_in_no++;
+				if (unlikely(l_ptr->oldest_deferred_in))
+					head = link_insert_deferred_queue(l_ptr,
+									  head);
+				if (likely(msg_is_dest(msg, tipc_own_addr))) {
+deliver:
+					if (likely(msg_isdata(msg))) {
+						node_unlock(n_ptr);
+						port_recv_msg(buf);
+						continue;
+					}
+					switch (msg_user(msg)) {
+					case MSG_BUNDLER:
+						l_ptr->stats.recv_bundles++;
+						l_ptr->stats.recv_bundled += 
+							msg_msgcnt(msg);
+						node_unlock(n_ptr);
+						link_recv_bundle(buf);
+						continue;
+					case ROUTE_DISTRIBUTOR:
+						node_unlock(n_ptr);
+						cluster_recv_routing_table(buf);
+						continue;
+					case NAME_DISTRIBUTOR:
+						node_unlock(n_ptr);
+						named_recv(buf);
+						continue;
+					case CONN_MANAGER:
+						node_unlock(n_ptr);
+						port_recv_proto_msg(buf);
+						continue;
+					case MSG_FRAGMENTER:
+						l_ptr->stats.recv_fragments++;
+						if (link_recv_fragment(
+							&l_ptr->defragm_buf, 
+							&buf, &msg)) {
+							l_ptr->stats.recv_fragmented++;
+							goto deliver;
+						}
+						break;
+					case CHANGEOVER_PROTOCOL:
+						type = msg_type(msg);
+						if (link_recv_changeover_msg(
+							&l_ptr, &buf)) {
+							msg = buf_msg(buf);
+							seq_no = msg_seqno(msg);
+							TIPC_SKB_CB(buf)->handle 
+								= b_ptr;
+							if (type == ORIGINAL_MSG)
+								goto deliver;
+							goto protocol_check;
+						}
+						break;
+					}
+				}
+				node_unlock(n_ptr);
+				net_route_msg(buf);
+				continue;
+			}
+			link_handle_out_of_seq_msg(l_ptr, buf);
+			head = link_insert_deferred_queue(l_ptr, head);
+			node_unlock(n_ptr);
+			continue;
+		}
+
+		if (msg_user(msg) == LINK_PROTOCOL) {
+			link_recv_proto_msg(l_ptr, buf);
+			head = link_insert_deferred_queue(l_ptr, head);
+			node_unlock(n_ptr);
+			continue;
+		}
+		msg_dbg(msg,"NSEQ<REC<");
+		link_state_event(l_ptr, TRAFFIC_MSG_EVT);
+
+		if (link_working_working(l_ptr)) {
+			/* Re-insert in front of queue */
+			msg_dbg(msg,"RECV-REINS:");
+			buf->next = head;
+			head = buf;
+			node_unlock(n_ptr);
+			continue;
+		}
+		node_unlock(n_ptr);
+cont:
+		buf_discard(buf);
+	}
+	read_unlock_bh(&net_lock);
+}
+
+/* 
+ * link_defer_buf(): Sort a received out-of-sequence packet 
+ *                   into the deferred reception queue.
+ * Returns the increase of the queue length,i.e. 0 or 1
+ */
+
+u32 link_defer_pkt(struct sk_buff **head,
+		   struct sk_buff **tail,
+		   struct sk_buff *buf)
+{
+	struct sk_buff *prev = 0;
+	struct sk_buff *crs = *head;
+	u32 seq_no = msg_seqno(buf_msg(buf));
+
+	buf->next = NULL;
+
+	/* Empty queue ? */
+	if (*head == NULL) {
+		*head = *tail = buf;
+		return 1;
+	}
+
+	/* Last ? */
+	if (less(msg_seqno(buf_msg(*tail)), seq_no)) {
+		(*tail)->next = buf;
+		*tail = buf;
+		return 1;
+	}
+
+	/* Scan through queue and sort it in */
+	do {
+		struct tipc_msg *msg = buf_msg(crs);
+
+		if (less(seq_no, msg_seqno(msg))) {
+			buf->next = crs;
+			if (prev)
+				prev->next = buf;
+			else
+				*head = buf;   
+			return 1;
+		}
+		if (seq_no == msg_seqno(msg)) {
+			break;
+		}
+		prev = crs;
+		crs = crs->next;
+	}
+	while (crs);
+
+	/* Message is a duplicate of an existing message */
+
+	buf_discard(buf);
+	return 0;
+}
+
+/** 
+ * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
+ */
+
+static void link_handle_out_of_seq_msg(struct link *l_ptr, 
+				       struct sk_buff *buf)
+{
+	u32 seq_no = msg_seqno(buf_msg(buf));
+
+	if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
+		link_recv_proto_msg(l_ptr, buf);
+		return;
+	}
+
+	dbg("rx OOS msg: seq_no %u, expecting %u (%u)\n", 
+	    seq_no, mod(l_ptr->next_in_no), l_ptr->next_in_no);
+
+	/* Record OOS packet arrival (force mismatch on next timeout) */
+
+	l_ptr->checkpoint--;
+
+	/* 
+	 * Discard packet if a duplicate; otherwise add it to deferred queue
+	 * and notify peer of gap as per protocol specification
+	 */
+
+	if (less(seq_no, mod(l_ptr->next_in_no))) {
+		l_ptr->stats.duplicates++;
+		buf_discard(buf);
+		return;
+	}
+
+	if (link_defer_pkt(&l_ptr->oldest_deferred_in,
+			   &l_ptr->newest_deferred_in, buf)) {
+		l_ptr->deferred_inqueue_sz++;
+		l_ptr->stats.deferred_recv++;
+		if ((l_ptr->deferred_inqueue_sz % 16) == 1)
+			link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
+	} else
+		l_ptr->stats.duplicates++;
+}
+
+/*
+ * Send protocol message to the other endpoint.
+ */
+void link_send_proto_msg(struct link *l_ptr, u32 msg_typ, int probe_msg,
+			 u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
+{
+	struct sk_buff *buf = 0;
+	struct tipc_msg *msg = l_ptr->pmsg;
+        u32 msg_size = sizeof(l_ptr->proto_msg);
+
+	if (link_blocked(l_ptr))
+		return;
+	msg_set_type(msg, msg_typ);
+	msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
+	msg_set_bcast_ack(msg, mod(l_ptr->owner->bclink.last_in)); 
+	msg_set_last_bcast(msg, bclink_get_last_sent());
+
+	if (msg_typ == STATE_MSG) {
+		u32 next_sent = mod(l_ptr->next_out_no);
+
+		if (!link_is_up(l_ptr))
+			return;
+		if (l_ptr->next_out)
+			next_sent = msg_seqno(buf_msg(l_ptr->next_out));
+		msg_set_next_sent(msg, next_sent);
+		if (l_ptr->oldest_deferred_in) {
+			u32 rec = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
+			gap = mod(rec - mod(l_ptr->next_in_no));
+		}
+		msg_set_seq_gap(msg, gap);
+		if (gap)
+			l_ptr->stats.sent_nacks++;
+		msg_set_link_tolerance(msg, tolerance);
+		msg_set_linkprio(msg, priority);
+		msg_set_max_pkt(msg, ack_mtu);
+		msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
+		msg_set_probe(msg, probe_msg != 0);
+		if (probe_msg) { 
+			u32 mtu = l_ptr->max_pkt;
+
+                        if ((mtu < l_ptr->max_pkt_target) &&
+			    link_working_working(l_ptr) &&
+			    l_ptr->fsm_msg_cnt) {
+				msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
+                                if (l_ptr->max_pkt_probes == 10) {
+                                        l_ptr->max_pkt_target = (msg_size - 4);
+                                        l_ptr->max_pkt_probes = 0;
+					msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
+                                }
+				l_ptr->max_pkt_probes++;
+                        }
+
+			l_ptr->stats.sent_probes++;
+                }
+		l_ptr->stats.sent_states++;
+	} else {		/* RESET_MSG or ACTIVATE_MSG */
+		msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
+		msg_set_seq_gap(msg, 0);
+		msg_set_next_sent(msg, 1);
+		msg_set_link_tolerance(msg, l_ptr->tolerance);
+		msg_set_linkprio(msg, l_ptr->priority);
+		msg_set_max_pkt(msg, l_ptr->max_pkt_target);
+	}
+
+	if (node_has_redundant_links(l_ptr->owner)) {
+		msg_set_redundant_link(msg);
+	} else {
+		msg_clear_redundant_link(msg);
+	}
+	msg_set_linkprio(msg, l_ptr->priority);
+
+	/* Ensure sequence number will not fit : */
+
+	msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
+
+	/* Congestion? */
+
+	if (bearer_congested(l_ptr->b_ptr, l_ptr)) {
+		if (!l_ptr->proto_msg_queue) {
+			l_ptr->proto_msg_queue =
+				buf_acquire(sizeof(l_ptr->proto_msg));
+		}
+		buf = l_ptr->proto_msg_queue;
+		if (!buf)
+			return;
+		memcpy(buf->data, (unchar *)msg, sizeof(l_ptr->proto_msg));
+		return;
+	}
+	msg_set_timestamp(msg, jiffies_to_msecs(jiffies));
+
+	/* Message can be sent */
+
+	msg_dbg(msg, ">>");
+
+	buf = buf_acquire(msg_size);
+	if (!buf)
+		return;
+
+	memcpy(buf->data, (unchar *)msg, sizeof(l_ptr->proto_msg));
+        msg_set_size(buf_msg(buf), msg_size);
+
+	if (bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
+		l_ptr->unacked_window = 0;
+		buf_discard(buf);
+		return;
+	}
+
+	/* New congestion */
+	bearer_schedule(l_ptr->b_ptr, l_ptr);
+	l_ptr->proto_msg_queue = buf;
+	l_ptr->stats.bearer_congs++;
+}
+
+/*
+ * Receive protocol message :
+ * Note that network plane id propagates through the network, and may 
+ * change at any time. The node with lowest address rules    
+ */
+
+static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf)
+{
+	u32 rec_gap = 0;
+	u32 max_pkt_info;
+        u32 max_pkt_ack;
+	u32 msg_tol;
+	struct tipc_msg *msg = buf_msg(buf);
+
+	dbg("AT(%u):", jiffies_to_msecs(jiffies));
+	msg_dbg(msg, "<<");
+	if (link_blocked(l_ptr))
+		goto exit;
+
+	/* record unnumbered packet arrival (force mismatch on next timeout) */
+
+	l_ptr->checkpoint--;
+
+	if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
+		if (tipc_own_addr > msg_prevnode(msg))
+			l_ptr->b_ptr->net_plane = msg_net_plane(msg);
+
+	l_ptr->owner->permit_changeover = msg_redundant_link(msg);
+
+	switch (msg_type(msg)) {
+	
+	case RESET_MSG:
+		if (!link_working_unknown(l_ptr) && l_ptr->peer_session) {
+			if (msg_session(msg) == l_ptr->peer_session) {
+				dbg("Duplicate RESET: %u<->%u\n",
+				    msg_session(msg), l_ptr->peer_session);                                     
+				break; /* duplicate: ignore */
+			}
+		}
+		/* fall thru' */
+	case ACTIVATE_MSG:
+		/* Update link settings according other endpoint's values */
+
+		strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
+
+		if ((msg_tol = msg_link_tolerance(msg)) &&
+		    (msg_tol > l_ptr->tolerance))
+			link_set_supervision_props(l_ptr, msg_tol);
+
+		if (msg_linkprio(msg) > l_ptr->priority)
+			l_ptr->priority = msg_linkprio(msg);
+
+		max_pkt_info = msg_max_pkt(msg);
+                if (max_pkt_info) {
+			if (max_pkt_info < l_ptr->max_pkt_target)
+				l_ptr->max_pkt_target = max_pkt_info;
+			if (l_ptr->max_pkt > l_ptr->max_pkt_target)
+				l_ptr->max_pkt = l_ptr->max_pkt_target;
+		} else {
+                        l_ptr->max_pkt = l_ptr->max_pkt_target;
+		}
+		l_ptr->owner->bclink.supported = (max_pkt_info != 0);
+
+		link_state_event(l_ptr, msg_type(msg));
+
+		l_ptr->peer_session = msg_session(msg);
+		l_ptr->peer_bearer_id = msg_bearer_id(msg);
+
+		/* Synchronize broadcast sequence numbers */
+		if (!node_has_redundant_links(l_ptr->owner)) {
+			l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg));
+		}
+		break;
+	case STATE_MSG:
+
+		if ((msg_tol = msg_link_tolerance(msg)))
+			link_set_supervision_props(l_ptr, msg_tol);
+		
+		if (msg_linkprio(msg) && 
+		    (msg_linkprio(msg) != l_ptr->priority)) {
+			warn("Changing prio <%s>: %u->%u\n",
+			     l_ptr->name, l_ptr->priority, msg_linkprio(msg));
+			l_ptr->priority = msg_linkprio(msg);
+			link_reset(l_ptr); /* Enforce change to take effect */
+			break;
+		}
+		link_state_event(l_ptr, TRAFFIC_MSG_EVT);
+		l_ptr->stats.recv_states++;
+		if (link_reset_unknown(l_ptr))
+			break;
+
+		if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
+			rec_gap = mod(msg_next_sent(msg) - 
+				      mod(l_ptr->next_in_no));
+		}
+
+		max_pkt_ack = msg_max_pkt(msg);
+                if (max_pkt_ack > l_ptr->max_pkt) {
+                        dbg("Link <%s> updated MTU %u -> %u\n",
+                            l_ptr->name, l_ptr->max_pkt, max_pkt_ack);
+                        l_ptr->max_pkt = max_pkt_ack;
+                        l_ptr->max_pkt_probes = 0;
+                }
+
+		max_pkt_ack = 0;
+                if (msg_probe(msg)) {
+			l_ptr->stats.recv_probes++;
+                        if (msg_size(msg) > sizeof(l_ptr->proto_msg)) {
+                                max_pkt_ack = msg_size(msg);
+                        }
+                }
+
+		/* Protocol message before retransmits, reduce loss risk */
+
+		bclink_check_gap(l_ptr->owner, msg_last_bcast(msg));
+
+		if (rec_gap || (msg_probe(msg))) {
+			link_send_proto_msg(l_ptr, STATE_MSG,
+					    0, rec_gap, 0, 0, max_pkt_ack);
+		}
+		if (msg_seq_gap(msg)) {
+			msg_dbg(msg, "With Gap:");
+			l_ptr->stats.recv_nacks++;
+			link_retransmit(l_ptr, l_ptr->first_out,
+					msg_seq_gap(msg));
+		}
+		break;
+	default:
+		msg_dbg(buf_msg(buf), "<DISCARDING UNKNOWN<");
+	}
+exit:
+	buf_discard(buf);
+}
+
+
+/*
+ * link_tunnel(): Send one message via a link belonging to 
+ * another bearer. Owner node is locked.
+ */
+void link_tunnel(struct link *l_ptr, 
+	    struct tipc_msg *tunnel_hdr, 
+	    struct tipc_msg  *msg,
+	    u32 selector)
+{
+	struct link *tunnel;
+	struct sk_buff *buf;
+	u32 length = msg_size(msg);
+
+	tunnel = l_ptr->owner->active_links[selector & 1];
+	if (!link_is_up(tunnel))
+		return;
+	msg_set_size(tunnel_hdr, length + INT_H_SIZE);
+	buf = buf_acquire(length + INT_H_SIZE);
+	if (!buf)
+		return;
+	memcpy(buf->data, (unchar *)tunnel_hdr, INT_H_SIZE);
+	memcpy(buf->data + INT_H_SIZE, (unchar *)msg, length);
+	dbg("%c->%c:", l_ptr->b_ptr->net_plane, tunnel->b_ptr->net_plane);
+	msg_dbg(buf_msg(buf), ">SEND>");
+	assert(tunnel);
+	link_send_buf(tunnel, buf);
+}
+
+
+
+/*
+ * changeover(): Send whole message queue via the remaining link
+ *               Owner node is locked.
+ */
+
+void link_changeover(struct link *l_ptr)
+{
+	u32 msgcount = l_ptr->out_queue_size;
+	struct sk_buff *crs = l_ptr->first_out;
+	struct link *tunnel = l_ptr->owner->active_links[0];
+	int split_bundles = node_has_redundant_links(l_ptr->owner);
+	struct tipc_msg tunnel_hdr;
+
+	if (!tunnel)
+		return;
+
+	if (!l_ptr->owner->permit_changeover)
+		return;
+
+	msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
+		 ORIGINAL_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr);
+	msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
+	msg_set_msgcnt(&tunnel_hdr, msgcount);
+	if (!l_ptr->first_out) {
+		struct sk_buff *buf;
+
+		assert(!msgcount);
+		buf = buf_acquire(INT_H_SIZE);
+		if (buf) {
+			memcpy(buf->data, (unchar *)&tunnel_hdr, INT_H_SIZE);
+			msg_set_size(&tunnel_hdr, INT_H_SIZE);
+			dbg("%c->%c:", l_ptr->b_ptr->net_plane,
+			    tunnel->b_ptr->net_plane);
+			msg_dbg(&tunnel_hdr, "EMPTY>SEND>");
+			link_send_buf(tunnel, buf);
+		} else {
+			warn("Memory squeeze; link changeover failed\n");
+		}
+		return;
+	}
+	while (crs) {
+		struct tipc_msg *msg = buf_msg(crs);
+
+		if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
+			u32 msgcount = msg_msgcnt(msg);
+			struct tipc_msg *m = msg_get_wrapped(msg);
+			unchar* pos = (unchar*)m;
+
+			while (msgcount--) {
+				msg_set_seqno(m,msg_seqno(msg));
+				link_tunnel(l_ptr, &tunnel_hdr, m,
+					    msg_link_selector(m));
+				pos += align(msg_size(m));
+				m = (struct tipc_msg *)pos;
+			}
+		} else {
+			link_tunnel(l_ptr, &tunnel_hdr, msg,
+				    msg_link_selector(msg));
+		}
+		crs = crs->next;
+	}
+}
+
+void link_send_duplicate(struct link *l_ptr, struct link *tunnel)
+{
+	struct sk_buff *iter;
+	struct tipc_msg tunnel_hdr;
+
+	msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
+		 DUPLICATE_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr);
+	msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
+	msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
+	iter = l_ptr->first_out;
+	while (iter) {
+		struct sk_buff *outbuf;
+		struct tipc_msg *msg = buf_msg(iter);
+		u32 length = msg_size(msg);
+
+		if (msg_user(msg) == MSG_BUNDLER)
+			msg_set_type(msg, CLOSED_MSG);
+		msg_set_ack(msg, mod(l_ptr->next_in_no - 1));	/* Update */
+		msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); 
+		msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
+		outbuf = buf_acquire(length + INT_H_SIZE);
+		if (outbuf == NULL) {
+			warn("Memory squeeze; buffer duplication failed\n");
+			return;
+		}
+		memcpy(outbuf->data, (unchar *)&tunnel_hdr, INT_H_SIZE);
+		memcpy(outbuf->data + INT_H_SIZE, iter->data, length);
+		dbg("%c->%c:", l_ptr->b_ptr->net_plane,
+		    tunnel->b_ptr->net_plane);
+		msg_dbg(buf_msg(outbuf), ">SEND>");
+		link_send_buf(tunnel, outbuf);
+		if (!link_is_up(l_ptr))
+			return;
+		iter = iter->next;
+	}
+}
+
+
+
+/**
+ * buf_extract - extracts embedded TIPC message from another message
+ * @skb: encapsulating message buffer
+ * @from_pos: offset to extract from
+ *
+ * Returns a new message buffer containing an embedded message.  The 
+ * encapsulating message itself is left unchanged.
+ */
+
+static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
+{
+	struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
+	u32 size = msg_size(msg);
+	struct sk_buff *eb;
+
+	eb = buf_acquire(size);
+	if (eb)
+		memcpy(eb->data, (unchar *)msg, size);
+	return eb;
+}
+
+/* 
+ *  link_recv_changeover_msg(): Receive tunneled packet sent
+ *  via other link. Node is locked. Return extracted buffer.
+ */
+
+static int link_recv_changeover_msg(struct link **l_ptr,
+				    struct sk_buff **buf)
+{
+	struct sk_buff *tunnel_buf = *buf;
+	struct link *dest_link;
+	struct tipc_msg *msg;
+	struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
+	u32 msg_typ = msg_type(tunnel_msg);
+	u32 msg_count = msg_msgcnt(tunnel_msg);
+
+	dest_link = (*l_ptr)->owner->links[msg_bearer_id(tunnel_msg)];
+	assert(dest_link != *l_ptr);
+	if (!dest_link) {
+		msg_dbg(tunnel_msg, "NOLINK/<REC<");
+		goto exit;
+	}
+	dbg("%c<-%c:", dest_link->b_ptr->net_plane,
+	    (*l_ptr)->b_ptr->net_plane);
+	*l_ptr = dest_link;
+	msg = msg_get_wrapped(tunnel_msg);
+
+	if (msg_typ == DUPLICATE_MSG) {
+		if (less(msg_seqno(msg), mod(dest_link->next_in_no))) {
+			msg_dbg(tunnel_msg, "DROP/<REC<");
+			goto exit;
+		}
+		*buf = buf_extract(tunnel_buf,INT_H_SIZE);
+		if (*buf == NULL) {
+			warn("Memory squeeze; failed to extract msg\n");
+			goto exit;
+		}
+		msg_dbg(tunnel_msg, "TNL<REC<");
+		buf_discard(tunnel_buf);
+		return 1;
+	}
+
+	/* First original message ?: */
+
+	if (link_is_up(dest_link)) {
+		msg_dbg(tunnel_msg, "UP/FIRST/<REC<");
+		link_reset(dest_link);
+		dest_link->exp_msg_count = msg_count;
+		if (!msg_count)
+			goto exit;
+	} else if (dest_link->exp_msg_count == START_CHANGEOVER) {
+		msg_dbg(tunnel_msg, "BLK/FIRST/<REC<");
+		dest_link->exp_msg_count = msg_count;
+		if (!msg_count)
+			goto exit;
+	}
+
+	/* Receive original message */
+
+	if (dest_link->exp_msg_count == 0) {
+		msg_dbg(tunnel_msg, "OVERDUE/DROP/<REC<");
+		dbg_print_link(dest_link, "LINK:");
+		goto exit;
+	}
+	dest_link->exp_msg_count--;
+	if (less(msg_seqno(msg), dest_link->reset_checkpoint)) {
+		msg_dbg(tunnel_msg, "DROP/DUPL/<REC<");
+		goto exit;
+	} else {
+		*buf = buf_extract(tunnel_buf, INT_H_SIZE);
+		if (*buf != NULL) {
+			msg_dbg(tunnel_msg, "TNL<REC<");
+			buf_discard(tunnel_buf);
+			return 1;
+		} else {
+			warn("Memory squeeze; dropped incoming msg\n");
+		}
+	}
+exit:
+	*buf = 0;
+	buf_discard(tunnel_buf);
+	return 0;
+}
+
+/*
+ *  Bundler functionality:
+ */
+void link_recv_bundle(struct sk_buff *buf)
+{
+	u32 msgcount = msg_msgcnt(buf_msg(buf));
+	u32 pos = INT_H_SIZE;
+	struct sk_buff *obuf;
+
+	msg_dbg(buf_msg(buf), "<BNDL<: ");
+	while (msgcount--) {
+		obuf = buf_extract(buf, pos);
+		if (obuf == NULL) {
+			char addr_string[16];
+
+			warn("Buffer allocation failure;\n");
+			warn("  incoming message(s) from %s lost\n",
+			     addr_string_fill(addr_string, 
+					      msg_orignode(buf_msg(buf))));
+			return;
+		};
+		pos += align(msg_size(buf_msg(obuf)));
+		msg_dbg(buf_msg(obuf), "     /");
+		net_route_msg(obuf);
+	}
+	buf_discard(buf);
+}
+
+/*
+ *  Fragmentation/defragmentation:
+ */
+
+
+/* 
+ * link_send_long_buf: Entry for buffers needing fragmentation.
+ * The buffer is complete, inclusive total message length. 
+ * Returns user data length.
+ */
+int link_send_long_buf(struct link *l_ptr, struct sk_buff *buf)
+{
+	struct tipc_msg *inmsg = buf_msg(buf);
+	struct tipc_msg fragm_hdr;
+	u32 insize = msg_size(inmsg);
+	u32 dsz = msg_data_sz(inmsg);
+	unchar *crs = buf->data;
+	u32 rest = insize;
+	u32 pack_sz = link_max_pkt(l_ptr);
+	u32 fragm_sz = pack_sz - INT_H_SIZE;
+	u32 fragm_no = 1;
+	u32 destaddr = msg_destnode(inmsg);
+
+	if (msg_short(inmsg))
+		destaddr = l_ptr->addr;
+
+	if (msg_routed(inmsg))
+		msg_set_prevnode(inmsg, tipc_own_addr);
+
+	/* Prepare reusable fragment header: */
+
+	msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
+		 TIPC_OK, INT_H_SIZE, destaddr);
+	msg_set_link_selector(&fragm_hdr, msg_link_selector(inmsg));
+	msg_set_long_msgno(&fragm_hdr, mod(l_ptr->long_msg_seq_no++));
+	msg_set_fragm_no(&fragm_hdr, fragm_no);
+	l_ptr->stats.sent_fragmented++;
+
+	/* Chop up message: */
+
+	while (rest > 0) {
+		struct sk_buff *fragm;
+
+		if (rest <= fragm_sz) {
+			fragm_sz = rest;
+			msg_set_type(&fragm_hdr, LAST_FRAGMENT);
+		}
+		fragm = buf_acquire(fragm_sz + INT_H_SIZE);
+		if (fragm == NULL) {
+			warn("Memory squeeze; failed to fragment msg\n");
+			dsz = -ENOMEM;
+			goto exit;
+		}
+		msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
+		memcpy(fragm->data, (unchar *)&fragm_hdr, INT_H_SIZE);
+		memcpy(fragm->data + INT_H_SIZE, crs, fragm_sz);
+
+		/*  Send queued messages first, if any: */
+
+		l_ptr->stats.sent_fragments++;
+		link_send_buf(l_ptr, fragm);
+		if (!link_is_up(l_ptr))
+			return dsz;
+		msg_set_fragm_no(&fragm_hdr, ++fragm_no);
+		rest -= fragm_sz;
+		crs += fragm_sz;
+		msg_set_type(&fragm_hdr, FRAGMENT);
+	}
+exit:
+	buf_discard(buf);
+	return dsz;
+}
+
+/* 
+ * A pending message being re-assembled must store certain values 
+ * to handle subsequent fragments correctly. The following functions 
+ * help storing these values in unused, available fields in the
+ * pending message. This makes dynamic memory allocation unecessary.
+ */
+
+static inline u32 get_long_msg_seqno(struct sk_buff *buf)
+{
+	return msg_seqno(buf_msg(buf));
+}
+
+static inline void set_long_msg_seqno(struct sk_buff *buf, u32 seqno)
+{
+	msg_set_seqno(buf_msg(buf), seqno);
+}
+
+static inline u32 get_fragm_size(struct sk_buff *buf)
+{
+	return msg_ack(buf_msg(buf));
+}
+
+static inline void set_fragm_size(struct sk_buff *buf, u32 sz)
+{
+	msg_set_ack(buf_msg(buf), sz);
+}
+
+static inline u32 get_expected_frags(struct sk_buff *buf)
+{
+	return msg_bcast_ack(buf_msg(buf));
+}
+
+static inline void set_expected_frags(struct sk_buff *buf, u32 exp)
+{
+	msg_set_bcast_ack(buf_msg(buf), exp);
+}
+
+static inline u32 get_timer_cnt(struct sk_buff *buf)
+{
+	return msg_reroute_cnt(buf_msg(buf));
+}
+
+static inline void incr_timer_cnt(struct sk_buff *buf)
+{
+	msg_incr_reroute_cnt(buf_msg(buf));
+}
+
+/* 
+ * link_recv_fragment(): Called with node lock on. Returns 
+ * the reassembled buffer if message is complete.
+ */
+int link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb, 
+		       struct tipc_msg **m)
+{
+	struct sk_buff *prev = 0;
+	struct sk_buff *fbuf = *fb;
+	struct tipc_msg *fragm = buf_msg(fbuf);
+	struct sk_buff *pbuf = *pending;
+	u32 long_msg_seq_no = msg_long_msgno(fragm);
+
+	*fb = 0;
+	msg_dbg(fragm,"FRG<REC<");
+
+	/* Is there an incomplete message waiting for this fragment? */
+
+	while (pbuf && ((msg_seqno(buf_msg(pbuf)) != long_msg_seq_no)
+			|| (msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
+		prev = pbuf;
+		pbuf = pbuf->next;
+	}
+
+	if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
+		struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
+		u32 msg_sz = msg_size(imsg);
+		u32 fragm_sz = msg_data_sz(fragm);
+		u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
+		u32 max =  TIPC_MAX_USER_MSG_SIZE + LONG_H_SIZE;
+		if (msg_type(imsg) == TIPC_MCAST_MSG)
+			max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
+		if (msg_size(imsg) > max) {
+			msg_dbg(fragm,"<REC<Oversized: ");
+			buf_discard(fbuf);
+			return 0;
+		}
+		pbuf = buf_acquire(msg_size(imsg));
+		if (pbuf != NULL) {
+			pbuf->next = *pending;
+			*pending = pbuf;
+			memcpy(pbuf->data, (unchar *)imsg, msg_data_sz(fragm));
+
+			/*  Prepare buffer for subsequent fragments. */
+
+			set_long_msg_seqno(pbuf, long_msg_seq_no); 
+			set_fragm_size(pbuf,fragm_sz); 
+			set_expected_frags(pbuf,exp_fragm_cnt - 1); 
+		} else {
+			warn("Memory squeeze; got no defragmenting buffer\n");
+		}
+		buf_discard(fbuf);
+		return 0;
+	} else if (pbuf && (msg_type(fragm) != FIRST_FRAGMENT)) {
+		u32 dsz = msg_data_sz(fragm);
+		u32 fsz = get_fragm_size(pbuf);
+		u32 crs = ((msg_fragm_no(fragm) - 1) * fsz);
+		u32 exp_frags = get_expected_frags(pbuf) - 1;
+		memcpy(pbuf->data + crs, msg_data(fragm), dsz);
+		buf_discard(fbuf);
+
+		/* Is message complete? */
+
+		if (exp_frags == 0) {
+			if (prev)
+				prev->next = pbuf->next;
+			else
+				*pending = pbuf->next;
+			msg_reset_reroute_cnt(buf_msg(pbuf));
+			*fb = pbuf;
+			*m = buf_msg(pbuf);
+			return 1;
+		}
+		set_expected_frags(pbuf,exp_frags);     
+		return 0;
+	}
+	dbg(" Discarding orphan fragment %x\n",fbuf);
+	msg_dbg(fragm,"ORPHAN:");
+	dbg("Pending long buffers:\n");
+	dbg_print_buf_chain(*pending);
+	buf_discard(fbuf);
+	return 0;
+}
+
+/**
+ * link_check_defragm_bufs - flush stale incoming message fragments
+ * @l_ptr: pointer to link
+ */
+
+static void link_check_defragm_bufs(struct link *l_ptr)
+{
+	struct sk_buff *prev = 0;
+	struct sk_buff *next = 0;
+	struct sk_buff *buf = l_ptr->defragm_buf;
+
+	if (!buf)
+		return;
+	if (!link_working_working(l_ptr))
+		return;
+	while (buf) {
+		u32 cnt = get_timer_cnt(buf);
+
+		next = buf->next;
+		if (cnt < 4) {
+			incr_timer_cnt(buf);
+			prev = buf;
+		} else {
+			dbg(" Discarding incomplete long buffer\n");
+			msg_dbg(buf_msg(buf), "LONG:");
+			dbg_print_link(l_ptr, "curr:");
+			dbg("Pending long buffers:\n");
+			dbg_print_buf_chain(l_ptr->defragm_buf);
+			if (prev)
+				prev->next = buf->next;
+			else
+				l_ptr->defragm_buf = buf->next;
+			buf_discard(buf);
+		}
+		buf = next;
+	}
+}
+
+
+
+static void link_set_supervision_props(struct link *l_ptr, u32 tolerance)
+{
+	l_ptr->tolerance = tolerance;
+	l_ptr->continuity_interval =
+		((tolerance / 4) > 500) ? 500 : tolerance / 4;
+	l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
+}
+
+
+void link_set_queue_limits(struct link *l_ptr, u32 window)
+{
+	/* Data messages from this node, inclusive FIRST_FRAGM */
+	l_ptr->queue_limit[DATA_LOW] = window;
+	l_ptr->queue_limit[DATA_MEDIUM] = (window / 3) * 4;
+	l_ptr->queue_limit[DATA_HIGH] = (window / 3) * 5;
+	l_ptr->queue_limit[DATA_CRITICAL] = (window / 3) * 6;
+	/* Transiting data messages,inclusive FIRST_FRAGM */
+	l_ptr->queue_limit[DATA_LOW + 4] = 300;
+	l_ptr->queue_limit[DATA_MEDIUM + 4] = 600;
+	l_ptr->queue_limit[DATA_HIGH + 4] = 900;
+	l_ptr->queue_limit[DATA_CRITICAL + 4] = 1200;
+	l_ptr->queue_limit[CONN_MANAGER] = 1200;
+	l_ptr->queue_limit[ROUTE_DISTRIBUTOR] = 1200;
+	l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
+	l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
+	/* FRAGMENT and LAST_FRAGMENT packets */
+	l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
+}
+
+/**
+ * link_find_link - locate link by name
+ * @name - ptr to link name string
+ * @node - ptr to area to be filled with ptr to associated node
+ * 
+ * Caller must hold 'net_lock' to ensure node and bearer are not deleted;
+ * this also prevents link deletion.
+ * 
+ * Returns pointer to link (or 0 if invalid link name).
+ */
+
+static struct link *link_find_link(const char *name, struct node **node)
+{
+	struct link_name link_name_parts;
+	struct bearer *b_ptr;
+	struct link *l_ptr; 
+
+	if (!link_name_validate(name, &link_name_parts))
+		return 0;
+
+	b_ptr = bearer_find_interface(link_name_parts.if_local);
+	if (!b_ptr)
+		return 0;
+
+	*node = node_find(link_name_parts.addr_peer); 
+	if (!*node)
+		return 0;
+
+	l_ptr = (*node)->links[b_ptr->identity];
+	if (!l_ptr || strcmp(l_ptr->name, name))
+		return 0;
+
+	return l_ptr;
+}
+
+struct sk_buff *link_cmd_config(const void *req_tlv_area, int req_tlv_space, 
+			        u16 cmd)
+{
+	struct tipc_link_config *args;
+        u32 new_value;
+	struct link *l_ptr;
+	struct node *node;
+        int res;
+
+	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
+		return cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
+
+	args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
+	new_value = ntohl(args->value);
+
+	if (!strcmp(args->name, bc_link_name)) {
+		if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
+		    (bclink_set_queue_limits(new_value) == 0))
+			return cfg_reply_none();
+	       	return cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
+					      " (cannot change setting on broadcast link)");
+	}
+
+	read_lock_bh(&net_lock);
+	l_ptr = link_find_link(args->name, &node); 
+	if (!l_ptr) {
+		read_unlock_bh(&net_lock);
+	       	return cfg_reply_error_string("link not found");
+	}
+
+	node_lock(node);
+	res = -EINVAL;
+	switch (cmd) {
+	case TIPC_CMD_SET_LINK_TOL: 
+		if ((new_value >= TIPC_MIN_LINK_TOL) && 
+		    (new_value <= TIPC_MAX_LINK_TOL)) {
+			link_set_supervision_props(l_ptr, new_value);
+			link_send_proto_msg(l_ptr, STATE_MSG, 
+					    0, 0, new_value, 0, 0);
+			res = TIPC_OK;
+		}
+		break;
+	case TIPC_CMD_SET_LINK_PRI: 
+		if (new_value < TIPC_NUM_LINK_PRI) {
+			l_ptr->priority = new_value;
+			link_send_proto_msg(l_ptr, STATE_MSG, 
+					    0, 0, 0, new_value, 0);
+			res = TIPC_OK;
+		}
+		break;
+	case TIPC_CMD_SET_LINK_WINDOW: 
+		if ((new_value >= TIPC_MIN_LINK_WIN) && 
+		    (new_value <= TIPC_MAX_LINK_WIN)) {
+			link_set_queue_limits(l_ptr, new_value);
+			res = TIPC_OK;
+		}
+		break;
+	}
+	node_unlock(node);
+
+	read_unlock_bh(&net_lock);
+	if (res)
+	       	return cfg_reply_error_string("cannot change link setting");
+
+	return cfg_reply_none();
+}
+
+/**
+ * link_reset_statistics - reset link statistics
+ * @l_ptr: pointer to link
+ */
+
+static void link_reset_statistics(struct link *l_ptr)
+{
+	memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
+	l_ptr->stats.sent_info = l_ptr->next_out_no;
+	l_ptr->stats.recv_info = l_ptr->next_in_no;
+}
+
+struct sk_buff *link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
+{
+	char *link_name;
+	struct link *l_ptr; 
+	struct node *node;
+
+	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
+		return cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
+
+	link_name = (char *)TLV_DATA(req_tlv_area);
+	if (!strcmp(link_name, bc_link_name)) {
+		if (bclink_reset_stats())
+			return cfg_reply_error_string("link not found");
+		return cfg_reply_none();
+	}
+
+	read_lock_bh(&net_lock);
+	l_ptr = link_find_link(link_name, &node); 
+	if (!l_ptr) {
+		read_unlock_bh(&net_lock);
+		return cfg_reply_error_string("link not found");
+	}
+
+	node_lock(node);
+	link_reset_statistics(l_ptr);
+	node_unlock(node);
+	read_unlock_bh(&net_lock);
+	return cfg_reply_none();
+}
+
+/**
+ * percent - convert count to a percentage of total (rounding up or down)
+ */
+
+static u32 percent(u32 count, u32 total)
+{
+	return (count * 100 + (total / 2)) / total;
+}
+
+/**
+ * link_stats - print link statistics
+ * @name: link name
+ * @buf: print buffer area
+ * @buf_size: size of print buffer area
+ * 
+ * Returns length of print buffer data string (or 0 if error)
+ */
+
+static int link_stats(const char *name, char *buf, const u32 buf_size)
+{
+	struct print_buf pb;
+	struct link *l_ptr; 
+	struct node *node;
+	char *status;
+	u32 profile_total = 0;
+
+	if (!strcmp(name, bc_link_name))
+		return bclink_stats(buf, buf_size);
+
+	printbuf_init(&pb, buf, buf_size);
+
+	read_lock_bh(&net_lock);
+	l_ptr = link_find_link(name, &node); 
+	if (!l_ptr) {
+		read_unlock_bh(&net_lock);
+		return 0;
+	}
+	node_lock(node);
+
+	if (link_is_active(l_ptr))
+		status = "ACTIVE";
+	else if (link_is_up(l_ptr))
+		status = "STANDBY";
+	else
+		status = "DEFUNCT";
+	tipc_printf(&pb, "Link <%s>\n"
+		         "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
+		         "  Window:%u packets\n", 
+		    l_ptr->name, status, link_max_pkt(l_ptr), 
+		    l_ptr->priority, l_ptr->tolerance, l_ptr->queue_limit[0]);
+	tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n", 
+		    l_ptr->next_in_no - l_ptr->stats.recv_info,
+		    l_ptr->stats.recv_fragments,
+		    l_ptr->stats.recv_fragmented,
+		    l_ptr->stats.recv_bundles,
+		    l_ptr->stats.recv_bundled);
+	tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n", 
+		    l_ptr->next_out_no - l_ptr->stats.sent_info,
+		    l_ptr->stats.sent_fragments,
+		    l_ptr->stats.sent_fragmented, 
+		    l_ptr->stats.sent_bundles,
+		    l_ptr->stats.sent_bundled);
+	profile_total = l_ptr->stats.msg_length_counts;
+	if (!profile_total)
+		profile_total = 1;
+	tipc_printf(&pb, "  TX profile sample:%u packets  average:%u octets\n"
+		         "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
+		         "-16354:%u%% -32768:%u%% -66000:%u%%\n",
+		    l_ptr->stats.msg_length_counts,
+		    l_ptr->stats.msg_lengths_total / profile_total,
+		    percent(l_ptr->stats.msg_length_profile[0], profile_total),
+		    percent(l_ptr->stats.msg_length_profile[1], profile_total),
+		    percent(l_ptr->stats.msg_length_profile[2], profile_total),
+		    percent(l_ptr->stats.msg_length_profile[3], profile_total),
+		    percent(l_ptr->stats.msg_length_profile[4], profile_total),
+		    percent(l_ptr->stats.msg_length_profile[5], profile_total),
+		    percent(l_ptr->stats.msg_length_profile[6], profile_total));
+	tipc_printf(&pb, "  RX states:%u probes:%u naks:%u defs:%u dups:%u\n", 
+		    l_ptr->stats.recv_states,
+		    l_ptr->stats.recv_probes,
+		    l_ptr->stats.recv_nacks,
+		    l_ptr->stats.deferred_recv, 
+		    l_ptr->stats.duplicates);
+	tipc_printf(&pb, "  TX states:%u probes:%u naks:%u acks:%u dups:%u\n", 
+		    l_ptr->stats.sent_states, 
+		    l_ptr->stats.sent_probes, 
+		    l_ptr->stats.sent_nacks, 
+		    l_ptr->stats.sent_acks, 
+		    l_ptr->stats.retransmitted);
+	tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
+		    l_ptr->stats.bearer_congs,
+		    l_ptr->stats.link_congs, 
+		    l_ptr->stats.max_queue_sz,
+		    l_ptr->stats.queue_sz_counts
+		    ? (l_ptr->stats.accu_queue_sz / l_ptr->stats.queue_sz_counts)
+		    : 0);
+
+	node_unlock(node);
+	read_unlock_bh(&net_lock);
+	return printbuf_validate(&pb);
+}
+
+#define MAX_LINK_STATS_INFO 2000
+
+struct sk_buff *link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
+{
+	struct sk_buff *buf;
+	struct tlv_desc *rep_tlv;
+	int str_len;
+
+	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
+		return cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
+
+	buf = cfg_reply_alloc(TLV_SPACE(MAX_LINK_STATS_INFO));
+	if (!buf)
+		return NULL;
+
+	rep_tlv = (struct tlv_desc *)buf->data;
+
+	str_len = link_stats((char *)TLV_DATA(req_tlv_area),
+			     (char *)TLV_DATA(rep_tlv), MAX_LINK_STATS_INFO);
+	if (!str_len) {
+		buf_discard(buf);
+	       	return cfg_reply_error_string("link not found");
+	}
+
+	skb_put(buf, TLV_SPACE(str_len));
+	TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
+
+	return buf;
+}
+
+#if 0
+int link_control(const char *name, u32 op, u32 val)
+{
+	int res = -EINVAL;
+	struct link *l_ptr;
+	u32 bearer_id;
+	struct node * node;
+	u32 a;
+
+	a = link_name2addr(name, &bearer_id);
+	read_lock_bh(&net_lock);
+	node = node_find(a);
+	if (node) {
+		node_lock(node);
+		l_ptr = node->links[bearer_id];
+		if (l_ptr) {
+			if (op == TIPC_REMOVE_LINK) {
+				struct bearer *b_ptr = l_ptr->b_ptr;
+				spin_lock_bh(&b_ptr->publ.lock);
+				link_delete(l_ptr);
+				spin_unlock_bh(&b_ptr->publ.lock);
+			}
+			if (op == TIPC_CMD_BLOCK_LINK) {
+				link_reset(l_ptr);
+				l_ptr->blocked = 1;
+			}
+			if (op == TIPC_CMD_UNBLOCK_LINK) {
+				l_ptr->blocked = 0;
+			}
+			res = TIPC_OK;
+		}
+		node_unlock(node);
+	}
+	read_unlock_bh(&net_lock);
+	return res;
+}
+#endif
+
+/**
+ * link_get_max_pkt - get maximum packet size to use when sending to destination
+ * @dest: network address of destination node
+ * @selector: used to select from set of active links
+ * 
+ * If no active link can be found, uses default maximum packet size.
+ */
+
+u32 link_get_max_pkt(u32 dest, u32 selector)
+{
+	struct node *n_ptr;
+	struct link *l_ptr;
+	u32 res = MAX_PKT_DEFAULT;
+	
+	if (dest == tipc_own_addr)
+		return MAX_MSG_SIZE;
+
+	read_lock_bh(&net_lock);        
+	n_ptr = node_select(dest, selector);
+	if (n_ptr) {
+		node_lock(n_ptr);
+		l_ptr = n_ptr->active_links[selector & 1];
+		if (l_ptr)
+			res = link_max_pkt(l_ptr);
+		node_unlock(n_ptr);
+	}
+	read_unlock_bh(&net_lock);       
+	return res;
+}
+
+#if 0
+static void link_dump_rec_queue(struct link *l_ptr)
+{
+	struct sk_buff *crs;
+
+	if (!l_ptr->oldest_deferred_in) {
+		info("Reception queue empty\n");
+		return;
+	}
+	info("Contents of Reception queue:\n");
+	crs = l_ptr->oldest_deferred_in;
+	while (crs) {
+		if (crs->data == (void *)0x0000a3a3) {
+			info("buffer %x invalid\n", crs);
+			return;
+		}
+		msg_dbg(buf_msg(crs), "In rec queue: \n");
+		crs = crs->next;
+	}
+}
+#endif
+
+static void link_dump_send_queue(struct link *l_ptr)
+{
+	if (l_ptr->next_out) {
+		info("\nContents of unsent queue:\n");
+		dbg_print_buf_chain(l_ptr->next_out);
+	}
+	info("\nContents of send queue:\n");
+	if (l_ptr->first_out) {
+		dbg_print_buf_chain(l_ptr->first_out);
+	}
+	info("Empty send queue\n");
+}
+
+static void link_print(struct link *l_ptr, struct print_buf *buf,
+		       const char *str)
+{
+	tipc_printf(buf, str);
+	if (link_reset_reset(l_ptr) || link_reset_unknown(l_ptr))
+		return;
+	tipc_printf(buf, "Link %x<%s>:",
+		    l_ptr->addr, l_ptr->b_ptr->publ.name);
+	tipc_printf(buf, ": NXO(%u):", mod(l_ptr->next_out_no));
+	tipc_printf(buf, "NXI(%u):", mod(l_ptr->next_in_no));
+	tipc_printf(buf, "SQUE");
+	if (l_ptr->first_out) {
+		tipc_printf(buf, "[%u..", msg_seqno(buf_msg(l_ptr->first_out)));
+		if (l_ptr->next_out)
+			tipc_printf(buf, "%u..",
+				    msg_seqno(buf_msg(l_ptr->next_out)));
+		tipc_printf(buf, "%u]",
+			    msg_seqno(buf_msg
+				      (l_ptr->last_out)), l_ptr->out_queue_size);
+		if ((mod(msg_seqno(buf_msg(l_ptr->last_out)) - 
+			 msg_seqno(buf_msg(l_ptr->first_out))) 
+		     != (l_ptr->out_queue_size - 1))
+		    || (l_ptr->last_out->next != 0)) {
+			tipc_printf(buf, "\nSend queue inconsistency\n");
+			tipc_printf(buf, "first_out= %x ", l_ptr->first_out);
+			tipc_printf(buf, "next_out= %x ", l_ptr->next_out);
+			tipc_printf(buf, "last_out= %x ", l_ptr->last_out);
+			link_dump_send_queue(l_ptr);
+		}
+	} else
+		tipc_printf(buf, "[]");
+	tipc_printf(buf, "SQSIZ(%u)", l_ptr->out_queue_size);
+	if (l_ptr->oldest_deferred_in) {
+		u32 o = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
+		u32 n = msg_seqno(buf_msg(l_ptr->newest_deferred_in));
+		tipc_printf(buf, ":RQUE[%u..%u]", o, n);
+		if (l_ptr->deferred_inqueue_sz != mod((n + 1) - o)) {
+			tipc_printf(buf, ":RQSIZ(%u)",
+				    l_ptr->deferred_inqueue_sz);
+		}
+	}
+	if (link_working_unknown(l_ptr))
+		tipc_printf(buf, ":WU");
+	if (link_reset_reset(l_ptr))
+		tipc_printf(buf, ":RR");
+	if (link_reset_unknown(l_ptr))
+		tipc_printf(buf, ":RU");
+	if (link_working_working(l_ptr))
+		tipc_printf(buf, ":WW");
+	tipc_printf(buf, "\n");
+}
+