name_distr.c

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/*
 * net/tipc/name_distr.c: TIPC name distribution code
 *
 * Copyright (c) 2000-2006, Ericsson AB
 * Copyright (c) 2005, 2010-2011, Wind River Systems
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "core.h"
#include "link.h"
#include "name_distr.h"

#define ITEM_SIZE sizeof(struct distr_item)

struct distr_item {
    __be32 type;
    __be32 lower;
    __be32 upper;
    __be32 ref;
    __be32 key;
};

struct publ_list {
    struct list_head list;
    u32 size;
};

static struct publ_list publ_zone = {
    .list = LIST_HEAD_INIT(publ_zone.list),
    .size = 0,
};

static struct publ_list publ_cluster = {
    .list = LIST_HEAD_INIT(publ_cluster.list),
    .size = 0,
};

static struct publ_list publ_node = {
    .list = LIST_HEAD_INIT(publ_node.list),
    .size = 0,
};

static struct publ_list *publ_lists[] = {
    NULL,
    &publ_zone, /* publ_lists[TIPC_ZONE_SCOPE]      */
    &publ_cluster,  /* publ_lists[TIPC_CLUSTER_SCOPE]   */
    &publ_node  /* publ_lists[TIPC_NODE_SCOPE]      */
};


static void publ_to_item(struct distr_item *i, struct publication *p)
{
    i->type = htonl(p->type);
    i->lower = htonl(p->lower);
    i->upper = htonl(p->upper);
    i->ref = htonl(p->ref);
    i->key = htonl(p->key);
}

static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
{
    struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
    struct tipc_msg *msg;

    if (buf != NULL) {
        msg = buf_msg(buf);
        tipc_msg_init(msg, NAME_DISTRIBUTOR, type, INT_H_SIZE, dest);
        msg_set_size(msg, INT_H_SIZE + size);
    }
    return buf;
}

static void named_cluster_distribute(struct sk_buff *buf)
{
    struct sk_buff *buf_copy;
    struct tipc_node *n_ptr;

    list_for_each_entry(n_ptr, &tipc_node_list, list) {
        if (tipc_node_active_links(n_ptr)) {
            buf_copy = skb_copy(buf, GFP_ATOMIC);
            if (!buf_copy)
                break;
            msg_set_destnode(buf_msg(buf_copy), n_ptr->addr);
            tipc_link_send(buf_copy, n_ptr->addr, n_ptr->addr);
        }
    }

    kfree_skb(buf);
}

void tipc_named_publish(struct publication *publ)
{
    struct sk_buff *buf;
    struct distr_item *item;

    list_add_tail(&publ->local_list, &publ_lists[publ->scope]->list);
    publ_lists[publ->scope]->size++;

    if (publ->scope == TIPC_NODE_SCOPE)
        return;

    buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
    if (!buf) {
        pr_warn("Publication distribution failure\n");
        return;
    }

    item = (struct distr_item *)msg_data(buf_msg(buf));
    publ_to_item(item, publ);
    named_cluster_distribute(buf);
}

void tipc_named_withdraw(struct publication *publ)
{
    struct sk_buff *buf;
    struct distr_item *item;

    list_del(&publ->local_list);
    publ_lists[publ->scope]->size--;

    if (publ->scope == TIPC_NODE_SCOPE)
        return;

    buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
    if (!buf) {
        pr_warn("Withdrawal distribution failure\n");
        return;
    }

    item = (struct distr_item *)msg_data(buf_msg(buf));
    publ_to_item(item, publ);
    named_cluster_distribute(buf);
}

/*
 * named_distribute - prepare name info for bulk distribution to another node
 */
static void named_distribute(struct list_head *message_list, u32 node,
                 struct publ_list *pls, u32 max_item_buf)
{
    struct publication *publ;
    struct sk_buff *buf = NULL;
    struct distr_item *item = NULL;
    u32 left = 0;
    u32 rest = pls->size * ITEM_SIZE;

    list_for_each_entry(publ, &pls->list, local_list) {
        if (!buf) {
            left = (rest <= max_item_buf) ? rest : max_item_buf;
            rest -= left;
            buf = named_prepare_buf(PUBLICATION, left, node);
            if (!buf) {
                pr_warn("Bulk publication failure\n");
                return;
            }
            item = (struct distr_item *)msg_data(buf_msg(buf));
        }
        publ_to_item(item, publ);
        item++;
        left -= ITEM_SIZE;
        if (!left) {
            list_add_tail((struct list_head *)buf, message_list);
            buf = NULL;
        }
    }
}

void tipc_named_node_up(unsigned long nodearg)
{
    struct tipc_node *n_ptr;
    struct tipc_link *l_ptr;
    struct list_head message_list;
    u32 node = (u32)nodearg;
    u32 max_item_buf = 0;

    /* compute maximum amount of publication data to send per message */
    read_lock_bh(&tipc_net_lock);
    n_ptr = tipc_node_find(node);
    if (n_ptr) {
        tipc_node_lock(n_ptr);
        l_ptr = n_ptr->active_links[0];
        if (l_ptr)
            max_item_buf = ((l_ptr->max_pkt - INT_H_SIZE) /
                ITEM_SIZE) * ITEM_SIZE;
        tipc_node_unlock(n_ptr);
    }
    read_unlock_bh(&tipc_net_lock);
    if (!max_item_buf)
        return;

    /* create list of publication messages, then send them as a unit */
    INIT_LIST_HEAD(&message_list);

    read_lock_bh(&tipc_nametbl_lock);
    named_distribute(&message_list, node, &publ_cluster, max_item_buf);
    named_distribute(&message_list, node, &publ_zone, max_item_buf);
    read_unlock_bh(&tipc_nametbl_lock);

    tipc_link_send_names(&message_list, (u32)node);
}

static void named_purge_publ(struct publication *publ)
{
    struct publication *p;

    write_lock_bh(&tipc_nametbl_lock);
    p = tipc_nametbl_remove_publ(publ->type, publ->lower,
                     publ->node, publ->ref, publ->key);
    if (p)
        tipc_nodesub_unsubscribe(&p->subscr);
    write_unlock_bh(&tipc_nametbl_lock);

    if (p != publ) {
        pr_err("Unable to remove publication from failed node\n"
               " (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
               publ->type, publ->lower, publ->node, publ->ref,
               publ->key);
    }

    kfree(p);
}

void tipc_named_recv(struct sk_buff *buf)
{
    struct publication *publ;
    struct tipc_msg *msg = buf_msg(buf);
    struct distr_item *item = (struct distr_item *)msg_data(msg);
    u32 count = msg_data_sz(msg) / ITEM_SIZE;

    write_lock_bh(&tipc_nametbl_lock);
    while (count--) {
        if (msg_type(msg) == PUBLICATION) {
            publ = tipc_nametbl_insert_publ(ntohl(item->type),
                            ntohl(item->lower),
                            ntohl(item->upper),
                            TIPC_CLUSTER_SCOPE,
                            msg_orignode(msg),
                            ntohl(item->ref),
                            ntohl(item->key));
            if (publ) {
                tipc_nodesub_subscribe(&publ->subscr,
                               msg_orignode(msg),
                               publ,
                               (net_ev_handler)
                               named_purge_publ);
            }
        } else if (msg_type(msg) == WITHDRAWAL) {
            publ = tipc_nametbl_remove_publ(ntohl(item->type),
                            ntohl(item->lower),
                            msg_orignode(msg),
                            ntohl(item->ref),
                            ntohl(item->key));

            if (publ) {
                tipc_nodesub_unsubscribe(&publ->subscr);
                kfree(publ);
            } else {
                pr_err("Unable to remove publication by node 0x%x\n"
                       " (type=%u, lower=%u, ref=%u, key=%u)\n",
                       msg_orignode(msg), ntohl(item->type),
                       ntohl(item->lower), ntohl(item->ref),
                       ntohl(item->key));
            }
        } else {
            pr_warn("Unrecognized name table message received\n");
        }
        item++;
    }
    write_unlock_bh(&tipc_nametbl_lock);
    kfree_skb(buf);
}

void tipc_named_reinit(void)
{
    struct publication *publ;
    int scope;

    write_lock_bh(&tipc_nametbl_lock);

    for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
        list_for_each_entry(publ, &publ_lists[scope]->list, local_list)
            publ->node = tipc_own_addr;

    write_unlock_bh(&tipc_nametbl_lock);
}