/*
 * net/tipc/cluster.c: TIPC cluster management routines
 *
 * Copyright (c) 2000-2006, Ericsson AB
 * Copyright (c) 2005, 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 "cluster.h"
#include "addr.h"
#include "node_subscr.h"
#include "link.h"
#include "node.h"
#include "net.h"
#include "msg.h"
#include "bearer.h"

static void tipc_cltr_multicast(struct cluster *c_ptr, struct sk_buff *buf,
                                u32 lower, u32 upper);
static struct sk_buff *tipc_cltr_prepare_routing_msg(u32 data_size, u32 dest);

struct tipc_node **tipc_local_nodes = NULL;
struct tipc_node_map tipc_cltr_bcast_nodes = {0,{0,}};
u32 tipc_highest_allowed_slave = 0;

struct cluster *tipc_cltr_create(u32 addr)
{
        struct _zone *z_ptr;
        struct cluster *c_ptr;
        int max_nodes;

        c_ptr = kzalloc(sizeof(*c_ptr), GFP_ATOMIC);
        if (c_ptr == NULL) {
                warn("Cluster creation failure, no memory\n");
                return NULL;
        }

        c_ptr->addr = tipc_addr(tipc_zone(addr), tipc_cluster(addr), 0);
        if (in_own_cluster(addr))
                max_nodes = LOWEST_SLAVE + tipc_max_slaves;
        else
                max_nodes = tipc_max_nodes + 1;

        c_ptr->nodes = kcalloc(max_nodes + 1, sizeof(void*), GFP_ATOMIC);
        if (c_ptr->nodes == NULL) {
                warn("Cluster creation failure, no memory for node area\n");
                kfree(c_ptr);
                return NULL;
        }

        if (in_own_cluster(addr))
                tipc_local_nodes = c_ptr->nodes;
        c_ptr->highest_slave = LOWEST_SLAVE - 1;
        c_ptr->highest_node = 0;

        z_ptr = tipc_zone_find(tipc_zone(addr));
        if (!z_ptr) {
                z_ptr = tipc_zone_create(addr);
        }
        if (!z_ptr) {
                kfree(c_ptr->nodes);
                kfree(c_ptr);
                return NULL;
        }

        tipc_zone_attach_cluster(z_ptr, c_ptr);
        c_ptr->owner = z_ptr;
        return c_ptr;
}

void tipc_cltr_delete(struct cluster *c_ptr)
{
        u32 n_num;

        if (!c_ptr)
                return;
        for (n_num = 1; n_num <= c_ptr->highest_node; n_num++) {
                tipc_node_delete(c_ptr->nodes[n_num]);
        }
        for (n_num = LOWEST_SLAVE; n_num <= c_ptr->highest_slave; n_num++) {
                tipc_node_delete(c_ptr->nodes[n_num]);
        }
        kfree(c_ptr->nodes);
        kfree(c_ptr);
}

u32 tipc_cltr_next_node(struct cluster *c_ptr, u32 addr)
{
        struct tipc_node *n_ptr;
        u32 n_num = tipc_node(addr) + 1;

        if (!c_ptr)
                return addr;
        for (; n_num <= c_ptr->highest_node; n_num++) {
                n_ptr = c_ptr->nodes[n_num];
                if (n_ptr && tipc_node_has_active_links(n_ptr))
                        return n_ptr->addr;
        }
        for (n_num = 1; n_num < tipc_node(addr); n_num++) {
                n_ptr = c_ptr->nodes[n_num];
                if (n_ptr && tipc_node_has_active_links(n_ptr))
                        return n_ptr->addr;
        }
        return 0;
}

void tipc_cltr_attach_node(struct cluster *c_ptr, struct tipc_node *n_ptr)
{
        u32 n_num = tipc_node(n_ptr->addr);
        u32 max_n_num = tipc_max_nodes;

        if (in_own_cluster(n_ptr->addr))
                max_n_num = tipc_highest_allowed_slave;
        assert(n_num > 0);
        assert(n_num <= max_n_num);
        assert(c_ptr->nodes[n_num] == NULL);
        c_ptr->nodes[n_num] = n_ptr;
        if (n_num > c_ptr->highest_node)
                c_ptr->highest_node = n_num;
}

/**
 * tipc_cltr_select_router - select router to a cluster
 *
 * Uses deterministic and fair algorithm.
 */

u32 tipc_cltr_select_router(struct cluster *c_ptr, u32 ref)
{
        u32 n_num;
        u32 ulim = c_ptr->highest_node;
        u32 mask;
        u32 tstart;

        assert(!in_own_cluster(c_ptr->addr));
        if (!ulim)
                return 0;

        /* Start entry must be random */
        mask = tipc_max_nodes;
        while (mask > ulim)
                mask >>= 1;
        tstart = ref & mask;
        n_num = tstart;

        /* Lookup upwards with wrap-around */
        do {
                if (tipc_node_is_up(c_ptr->nodes[n_num]))
                        break;
        } while (++n_num <= ulim);
        if (n_num > ulim) {
                n_num = 1;
                do {
                        if (tipc_node_is_up(c_ptr->nodes[n_num]))
                                break;
                } while (++n_num < tstart);
                if (n_num == tstart)
                        return 0;
        }
        assert(n_num <= ulim);
        return tipc_node_select_router(c_ptr->nodes[n_num], ref);
}

/**
 * tipc_cltr_select_node - select destination node within a remote cluster
 *
 * Uses deterministic and fair algorithm.
 */

struct tipc_node *tipc_cltr_select_node(struct cluster *c_ptr, u32 selector)
{
        u32 n_num;
        u32 mask = tipc_max_nodes;
        u32 start_entry;

        assert(!in_own_cluster(c_ptr->addr));
        if (!c_ptr->highest_node)
                return NULL;

        /* Start entry must be random */
        while (mask > c_ptr->highest_node) {
                mask >>= 1;
        }
        start_entry = (selector & mask) ? selector & mask : 1u;
        assert(start_entry <= c_ptr->highest_node);

        /* Lookup upwards with wrap-around */
        for (n_num = start_entry; n_num <= c_ptr->highest_node; n_num++) {
                if (tipc_node_has_active_links(c_ptr->nodes[n_num]))
                        return c_ptr->nodes[n_num];
        }
        for (n_num = 1; n_num < start_entry; n_num++) {
                if (tipc_node_has_active_links(c_ptr->nodes[n_num]))
                        return c_ptr->nodes[n_num];
        }
        return NULL;
}

/*
 *    Routing table management: See description in node.c
 */

static struct sk_buff *tipc_cltr_prepare_routing_msg(u32 data_size, u32 dest)
{
        u32 size = INT_H_SIZE + data_size;
        struct sk_buff *buf = buf_acquire(size);
        struct tipc_msg *msg;

        if (buf) {
                msg = buf_msg(buf);
                memset((char *)msg, 0, size);
                msg_init(msg, ROUTE_DISTRIBUTOR, 0, INT_H_SIZE, dest);
        }
        return buf;
}

void tipc_cltr_bcast_new_route(struct cluster *c_ptr, u32 dest,
                             u32 lower, u32 upper)
{
        struct sk_buff *buf = tipc_cltr_prepare_routing_msg(0, c_ptr->addr);
        struct tipc_msg *msg;

        if (buf) {
                msg = buf_msg(buf);
                msg_set_remote_node(msg, dest);
                msg_set_type(msg, ROUTE_ADDITION);
                tipc_cltr_multicast(c_ptr, buf, lower, upper);
        } else {
                warn("Memory squeeze: broadcast of new route failed\n");
        }
}

void tipc_cltr_bcast_lost_route(struct cluster *c_ptr, u32 dest,
                                u32 lower, u32 upper)
{
        struct sk_buff *buf = tipc_cltr_prepare_routing_msg(0, c_ptr->addr);
        struct tipc_msg *msg;

        if (buf) {
                msg = buf_msg(buf);
                msg_set_remote_node(msg, dest);
                msg_set_type(msg, ROUTE_REMOVAL);
                tipc_cltr_multicast(c_ptr, buf, lower, upper);
        } else {
                warn("Memory squeeze: broadcast of lost route failed\n");
        }
}

void tipc_cltr_send_slave_routes(struct cluster *c_ptr, u32 dest)
{
        struct sk_buff *buf;
        struct tipc_msg *msg;
        u32 highest = c_ptr->highest_slave;
        u32 n_num;
        int send = 0;

        assert(!is_slave(dest));
        assert(in_own_cluster(dest));
        assert(in_own_cluster(c_ptr->addr));
        if (highest <= LOWEST_SLAVE)
                return;
        buf = tipc_cltr_prepare_routing_msg(highest - LOWEST_SLAVE + 1,
                                            c_ptr->addr);
        if (buf) {
                msg = buf_msg(buf);
                msg_set_remote_node(msg, c_ptr->addr);
                msg_set_type(msg, SLAVE_ROUTING_TABLE);
                for (n_num = LOWEST_SLAVE; n_num <= highest; n_num++) {
                        if (c_ptr->nodes[n_num] &&
                            tipc_node_has_active_links(c_ptr->nodes[n_num])) {
                                send = 1;
                                msg_set_dataoctet(msg, n_num);
                        }
                }
                if (send)
                        tipc_link_send(buf, dest, dest);
                else
                        buf_discard(buf);
        } else {
                warn("Memory squeeze: broadcast of lost route failed\n");
        }
}

void tipc_cltr_send_ext_routes(struct cluster *c_ptr, u32 dest)
{
        struct sk_buff *buf;
        struct tipc_msg *msg;
        u32 highest = c_ptr->highest_node;
        u32 n_num;
        int send = 0;

        if (in_own_cluster(c_ptr->addr))
                return;
        assert(!is_slave(dest));
        assert(in_own_cluster(dest));
        highest = c_ptr->highest_node;
        buf = tipc_cltr_prepare_routing_msg(highest + 1, c_ptr->addr);
        if (buf) {
                msg = buf_msg(buf);
                msg_set_remote_node(msg, c_ptr->addr);
                msg_set_type(msg, EXT_ROUTING_TABLE);
                for (n_num = 1; n_num <= highest; n_num++) {
                        if (c_ptr->nodes[n_num] &&
                            tipc_node_has_active_links(c_ptr->nodes[n_num])) {
                                send = 1;
                                msg_set_dataoctet(msg, n_num);
                        }
                }
                if (send)
                        tipc_link_send(buf, dest, dest);
                else
                        buf_discard(buf);
        } else {
                warn("Memory squeeze: broadcast of external route failed\n");
        }
}

void tipc_cltr_send_local_routes(struct cluster *c_ptr, u32 dest)
{
        struct sk_buff *buf;
        struct tipc_msg *msg;
        u32 highest = c_ptr->highest_node;
        u32 n_num;
        int send = 0;

        assert(is_slave(dest));
        assert(in_own_cluster(c_ptr->addr));
        buf = tipc_cltr_prepare_routing_msg(highest, c_ptr->addr);
        if (buf) {
                msg = buf_msg(buf);
                msg_set_remote_node(msg, c_ptr->addr);
                msg_set_type(msg, LOCAL_ROUTING_TABLE);
                for (n_num = 1; n_num <= highest; n_num++) {
                        if (c_ptr->nodes[n_num] &&
                            tipc_node_has_active_links(c_ptr->nodes[n_num])) {
                                send = 1;
                                msg_set_dataoctet(msg, n_num);
                        }
                }
                if (send)
                        tipc_link_send(buf, dest, dest);
                else
                        buf_discard(buf);
        } else {
                warn("Memory squeeze: broadcast of local route failed\n");
        }
}

void tipc_cltr_recv_routing_table(struct sk_buff *buf)
{
        struct tipc_msg *msg = buf_msg(buf);
        struct cluster *c_ptr;
        struct tipc_node *n_ptr;
        unchar *node_table;
        u32 table_size;
        u32 router;
        u32 rem_node = msg_remote_node(msg);
        u32 z_num;
        u32 c_num;
        u32 n_num;

        c_ptr = tipc_cltr_find(rem_node);
        if (!c_ptr) {
                c_ptr = tipc_cltr_create(rem_node);
                if (!c_ptr) {
                        buf_discard(buf);
                        return;
                }
        }

        node_table = buf->data + msg_hdr_sz(msg);
        table_size = msg_size(msg) - msg_hdr_sz(msg);
        router = msg_prevnode(msg);
        z_num = tipc_zone(rem_node);
        c_num = tipc_cluster(rem_node);

        switch (msg_type(msg)) {
        case LOCAL_ROUTING_TABLE:
                assert(is_slave(tipc_own_addr));
        case EXT_ROUTING_TABLE:
                for (n_num = 1; n_num < table_size; n_num++) {
                        if (node_table[n_num]) {
                                u32 addr = tipc_addr(z_num, c_num, n_num);
                                n_ptr = c_ptr->nodes[n_num];
                                if (!n_ptr) {
                                        n_ptr = tipc_node_create(addr);
                                }
                                if (n_ptr)
                                        tipc_node_add_router(n_ptr, router);
                        }
                }
                break;
        case SLAVE_ROUTING_TABLE:
                assert(!is_slave(tipc_own_addr));
                assert(in_own_cluster(c_ptr->addr));
                for (n_num = 1; n_num < table_size; n_num++) {
                        if (node_table[n_num]) {
                                u32 slave_num = n_num + LOWEST_SLAVE;
                                u32 addr = tipc_addr(z_num, c_num, slave_num);
                                n_ptr = c_ptr->nodes[slave_num];
                                if (!n_ptr) {
                                        n_ptr = tipc_node_create(addr);
                                }
                                if (n_ptr)
                                        tipc_node_add_router(n_ptr, router);
                        }
                }
                break;
        case ROUTE_ADDITION:
                if (!is_slave(tipc_own_addr)) {
                        assert(!in_own_cluster(c_ptr->addr)
                               || is_slave(rem_node));
                } else {
                        assert(in_own_cluster(c_ptr->addr)
                               && !is_slave(rem_node));
                }
                n_ptr = c_ptr->nodes[tipc_node(rem_node)];
                if (!n_ptr)
                        n_ptr = tipc_node_create(rem_node);
                if (n_ptr)
                        tipc_node_add_router(n_ptr, router);
                break;
        case ROUTE_REMOVAL:
                if (!is_slave(tipc_own_addr)) {
                        assert(!in_own_cluster(c_ptr->addr)
                               || is_slave(rem_node));
                } else {
                        assert(in_own_cluster(c_ptr->addr)
                               && !is_slave(rem_node));
                }
                n_ptr = c_ptr->nodes[tipc_node(rem_node)];
                if (n_ptr)
                        tipc_node_remove_router(n_ptr, router);
                break;
        default:
                assert(!"Illegal routing manager message received\n");
        }
        buf_discard(buf);
}

void tipc_cltr_remove_as_router(struct cluster *c_ptr, u32 router)
{
        u32 start_entry;
        u32 tstop;
        u32 n_num;

        if (is_slave(router))
                return; /* Slave nodes can not be routers */

        if (in_own_cluster(c_ptr->addr)) {
                start_entry = LOWEST_SLAVE;
                tstop = c_ptr->highest_slave;
        } else {
                start_entry = 1;
                tstop = c_ptr->highest_node;
        }

        for (n_num = start_entry; n_num <= tstop; n_num++) {
                if (c_ptr->nodes[n_num]) {
                        tipc_node_remove_router(c_ptr->nodes[n_num], router);
                }
        }
}

/**
 * tipc_cltr_multicast - multicast message to local nodes
 */

static void tipc_cltr_multicast(struct cluster *c_ptr, struct sk_buff *buf,
                         u32 lower, u32 upper)
{
        struct sk_buff *buf_copy;
        struct tipc_node *n_ptr;
        u32 n_num;
        u32 tstop;

        assert(lower <= upper);
        assert(((lower >= 1) && (lower <= tipc_max_nodes)) ||
               ((lower >= LOWEST_SLAVE) && (lower <= tipc_highest_allowed_slave)));
        assert(((upper >= 1) && (upper <= tipc_max_nodes)) ||
               ((upper >= LOWEST_SLAVE) && (upper <= tipc_highest_allowed_slave)));
        assert(in_own_cluster(c_ptr->addr));

        tstop = is_slave(upper) ? c_ptr->highest_slave : c_ptr->highest_node;
        if (tstop > upper)
                tstop = upper;
        for (n_num = lower; n_num <= tstop; n_num++) {
                n_ptr = c_ptr->nodes[n_num];
                if (n_ptr && tipc_node_has_active_links(n_ptr)) {
                        buf_copy = skb_copy(buf, GFP_ATOMIC);
                        if (buf_copy == NULL)
                                break;
                        msg_set_destnode(buf_msg(buf_copy), n_ptr->addr);
                        tipc_link_send(buf_copy, n_ptr->addr, n_ptr->addr);
                }
        }
        buf_discard(buf);
}

/**
 * tipc_cltr_broadcast - broadcast message to all nodes within cluster
 */

void tipc_cltr_broadcast(struct sk_buff *buf)
{
        struct sk_buff *buf_copy;
        struct cluster *c_ptr;
        struct tipc_node *n_ptr;
        u32 n_num;
        u32 tstart;
        u32 tstop;
        u32 node_type;

        if (tipc_mode == TIPC_NET_MODE) {
                c_ptr = tipc_cltr_find(tipc_own_addr);
                assert(in_own_cluster(c_ptr->addr));    /* For now */

                /* Send to standard nodes, then repeat loop sending to slaves */
                tstart = 1;
                tstop = c_ptr->highest_node;
                for (node_type = 1; node_type <= 2; node_type++) {
                        for (n_num = tstart; n_num <= tstop; n_num++) {
                                n_ptr = c_ptr->nodes[n_num];
                                if (n_ptr && tipc_node_has_active_links(n_ptr)) {
                                        buf_copy = skb_copy(buf, GFP_ATOMIC);
                                        if (buf_copy == NULL)
                                                goto exit;
                                        msg_set_destnode(buf_msg(buf_copy),
                                                         n_ptr->addr);
                                        tipc_link_send(buf_copy, n_ptr->addr,
                                                       n_ptr->addr);
                                }
                        }
                        tstart = LOWEST_SLAVE;
                        tstop = c_ptr->highest_slave;
                }
        }
exit:
        buf_discard(buf);
}

int tipc_cltr_init(void)
{
        tipc_highest_allowed_slave = LOWEST_SLAVE + tipc_max_slaves;
        return tipc_cltr_create(tipc_own_addr) ? 0 : -ENOMEM;
}