Merge tag 'pci-v3.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaa...

[deliverable/linux.git] / net / tipc / bearer.c

/*
 * net/tipc/bearer.c: TIPC bearer code
 *
 * Copyright (c) 1996-2006, 2013, Ericsson AB
 * Copyright (c) 2004-2006, 2010-2013, 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 "config.h"
#include "bearer.h"
#include "discover.h"

#define MAX_ADDR_STR 60

static struct tipc_media * const media_info_array[] = {
        &eth_media_info,
#ifdef CONFIG_TIPC_MEDIA_IB
        &ib_media_info,
#endif
        NULL
};

struct tipc_bearer tipc_bearers[MAX_BEARERS];

static void bearer_disable(struct tipc_bearer *b_ptr);

/**
 * tipc_media_find - locates specified media object by name
 */
struct tipc_media *tipc_media_find(const char *name)
{
        u32 i;

        for (i = 0; media_info_array[i] != NULL; i++) {
                if (!strcmp(media_info_array[i]->name, name))
                        break;
        }
        return media_info_array[i];
}

/**
 * media_find_id - locates specified media object by type identifier
 */
static struct tipc_media *media_find_id(u8 type)
{
        u32 i;

        for (i = 0; media_info_array[i] != NULL; i++) {
                if (media_info_array[i]->type_id == type)
                        break;
        }
        return media_info_array[i];
}

/**
 * tipc_media_addr_printf - record media address in print buffer
 */
void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
{
        char addr_str[MAX_ADDR_STR];
        struct tipc_media *m_ptr;
        int ret;

        m_ptr = media_find_id(a->media_id);

        if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str)))
                ret = tipc_snprintf(buf, len, "%s(%s)", m_ptr->name, addr_str);
        else {
                u32 i;

                ret = tipc_snprintf(buf, len, "UNKNOWN(%u)", a->media_id);
                for (i = 0; i < sizeof(a->value); i++)
                        ret += tipc_snprintf(buf - ret, len + ret,
                                            "-%02x", a->value[i]);
        }
}

/**
 * tipc_media_get_names - record names of registered media in buffer
 */
struct sk_buff *tipc_media_get_names(void)
{
        struct sk_buff *buf;
        int i;

        buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME));
        if (!buf)
                return NULL;

        for (i = 0; media_info_array[i] != NULL; i++) {
                tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME,
                                    media_info_array[i]->name,
                                    strlen(media_info_array[i]->name) + 1);
        }
        return buf;
}

/**
 * bearer_name_validate - validate & (optionally) deconstruct bearer name
 * @name: ptr to bearer name string
 * @name_parts: ptr to area for bearer name components (or NULL if not needed)
 *
 * Returns 1 if bearer name is valid, otherwise 0.
 */
static int bearer_name_validate(const char *name,
                                struct tipc_bearer_names *name_parts)
{
        char name_copy[TIPC_MAX_BEARER_NAME];
        char *media_name;
        char *if_name;
        u32 media_len;
        u32 if_len;

        /* copy bearer name & ensure length is OK */
        name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
        /* need above in case non-Posix strncpy() doesn't pad with nulls */
        strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
        if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
                return 0;

        /* ensure all component parts of bearer name are present */
        media_name = name_copy;
        if_name = strchr(media_name, ':');
        if (if_name == NULL)
                return 0;
        *(if_name++) = 0;
        media_len = if_name - media_name;
        if_len = strlen(if_name) + 1;

        /* validate component parts of bearer name */
        if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
            (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
                return 0;

        /* return bearer name components, if necessary */
        if (name_parts) {
                strcpy(name_parts->media_name, media_name);
                strcpy(name_parts->if_name, if_name);
        }
        return 1;
}

/**
 * tipc_bearer_find - locates bearer object with matching bearer name
 */
struct tipc_bearer *tipc_bearer_find(const char *name)
{
        struct tipc_bearer *b_ptr;
        u32 i;

        for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
                if (b_ptr->active && (!strcmp(b_ptr->name, name)))
                        return b_ptr;
        }
        return NULL;
}

/**
 * tipc_bearer_get_names - record names of bearers in buffer
 */
struct sk_buff *tipc_bearer_get_names(void)
{
        struct sk_buff *buf;
        struct tipc_bearer *b;
        int i, j;

        buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME));
        if (!buf)
                return NULL;

        read_lock_bh(&tipc_net_lock);
        for (i = 0; media_info_array[i] != NULL; i++) {
                for (j = 0; j < MAX_BEARERS; j++) {
                        b = &tipc_bearers[j];
                        if (b->active && (b->media == media_info_array[i])) {
                                tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
                                                    b->name,
                                                    strlen(b->name) + 1);
                        }
                }
        }
        read_unlock_bh(&tipc_net_lock);
        return buf;
}

void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest)
{
        tipc_nmap_add(&b_ptr->nodes, dest);
        tipc_bcbearer_sort();
        tipc_disc_add_dest(b_ptr->link_req);
}

void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest)
{
        tipc_nmap_remove(&b_ptr->nodes, dest);
        tipc_bcbearer_sort();
        tipc_disc_remove_dest(b_ptr->link_req);
}

/**
 * tipc_enable_bearer - enable bearer with the given name
 */
int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority)
{
        struct tipc_bearer *b_ptr;
        struct tipc_media *m_ptr;
        struct tipc_bearer_names b_names;
        char addr_string[16];
        u32 bearer_id;
        u32 with_this_prio;
        u32 i;
        int res = -EINVAL;

        if (!tipc_own_addr) {
                pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
                        name);
                return -ENOPROTOOPT;
        }
        if (!bearer_name_validate(name, &b_names)) {
                pr_warn("Bearer <%s> rejected, illegal name\n", name);
                return -EINVAL;
        }
        if (tipc_addr_domain_valid(disc_domain) &&
            (disc_domain != tipc_own_addr)) {
                if (tipc_in_scope(disc_domain, tipc_own_addr)) {
                        disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK;
                        res = 0;   /* accept any node in own cluster */
                } else if (in_own_cluster_exact(disc_domain))
                        res = 0;   /* accept specified node in own cluster */
        }
        if (res) {
                pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
                        name);
                return -EINVAL;
        }
        if ((priority > TIPC_MAX_LINK_PRI) &&
            (priority != TIPC_MEDIA_LINK_PRI)) {
                pr_warn("Bearer <%s> rejected, illegal priority\n", name);
                return -EINVAL;
        }

        write_lock_bh(&tipc_net_lock);

        m_ptr = tipc_media_find(b_names.media_name);
        if (!m_ptr) {
                pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
                        name, b_names.media_name);
                goto exit;
        }

        if (priority == TIPC_MEDIA_LINK_PRI)
                priority = m_ptr->priority;

restart:
        bearer_id = MAX_BEARERS;
        with_this_prio = 1;
        for (i = MAX_BEARERS; i-- != 0; ) {
                if (!tipc_bearers[i].active) {
                        bearer_id = i;
                        continue;
                }
                if (!strcmp(name, tipc_bearers[i].name)) {
                        pr_warn("Bearer <%s> rejected, already enabled\n",
                                name);
                        goto exit;
                }
                if ((tipc_bearers[i].priority == priority) &&
                    (++with_this_prio > 2)) {
                        if (priority-- == 0) {
                                pr_warn("Bearer <%s> rejected, duplicate priority\n",
                                        name);
                                goto exit;
                        }
                        pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
                                name, priority + 1, priority);
                        goto restart;
                }
        }
        if (bearer_id >= MAX_BEARERS) {
                pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
                        name, MAX_BEARERS);
                goto exit;
        }

        b_ptr = &tipc_bearers[bearer_id];
        strcpy(b_ptr->name, name);
        b_ptr->media = m_ptr;
        res = m_ptr->enable_media(b_ptr);
        if (res) {
                pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
                        name, -res);
                goto exit;
        }

        b_ptr->identity = bearer_id;
        b_ptr->tolerance = m_ptr->tolerance;
        b_ptr->window = m_ptr->window;
        b_ptr->net_plane = bearer_id + 'A';
        b_ptr->active = 1;
        b_ptr->priority = priority;
        INIT_LIST_HEAD(&b_ptr->links);
        spin_lock_init(&b_ptr->lock);

        res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
        if (res) {
                bearer_disable(b_ptr);
                pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
                        name);
                goto exit;
        }
        pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
                name,
                tipc_addr_string_fill(addr_string, disc_domain), priority);
exit:
        write_unlock_bh(&tipc_net_lock);
        return res;
}

/**
 * tipc_reset_bearer - Reset all links established over this bearer
 */
static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
{
        struct tipc_link *l_ptr;
        struct tipc_link *temp_l_ptr;

        read_lock_bh(&tipc_net_lock);
        pr_info("Resetting bearer <%s>\n", b_ptr->name);
        spin_lock_bh(&b_ptr->lock);
        list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
                struct tipc_node *n_ptr = l_ptr->owner;

                spin_lock_bh(&n_ptr->lock);
                tipc_link_reset(l_ptr);
                spin_unlock_bh(&n_ptr->lock);
        }
        spin_unlock_bh(&b_ptr->lock);
        read_unlock_bh(&tipc_net_lock);
        return 0;
}

/**
 * bearer_disable
 *
 * Note: This routine assumes caller holds tipc_net_lock.
 */
static void bearer_disable(struct tipc_bearer *b_ptr)
{
        struct tipc_link *l_ptr;
        struct tipc_link *temp_l_ptr;
        struct tipc_link_req *temp_req;

        pr_info("Disabling bearer <%s>\n", b_ptr->name);
        spin_lock_bh(&b_ptr->lock);
        b_ptr->media->disable_media(b_ptr);
        list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) {
                tipc_link_delete(l_ptr);
        }
        temp_req = b_ptr->link_req;
        b_ptr->link_req = NULL;
        spin_unlock_bh(&b_ptr->lock);

        if (temp_req)
                tipc_disc_delete(temp_req);

        memset(b_ptr, 0, sizeof(struct tipc_bearer));
}

int tipc_disable_bearer(const char *name)
{
        struct tipc_bearer *b_ptr;
        int res;

        write_lock_bh(&tipc_net_lock);
        b_ptr = tipc_bearer_find(name);
        if (b_ptr == NULL) {
                pr_warn("Attempt to disable unknown bearer <%s>\n", name);
                res = -EINVAL;
        } else {
                bearer_disable(b_ptr);
                res = 0;
        }
        write_unlock_bh(&tipc_net_lock);
        return res;
}


/* tipc_l2_media_addr_set - initialize Ethernet media address structure
 *
 * Media-dependent "value" field stores MAC address in first 6 bytes
 * and zeroes out the remaining bytes.
 */
void tipc_l2_media_addr_set(const struct tipc_bearer *b,
                            struct tipc_media_addr *a, char *mac)
{
        int len = b->media->hwaddr_len;

        if (unlikely(sizeof(a->value) < len)) {
                WARN_ONCE(1, "Media length invalid\n");
                return;
        }

        memcpy(a->value, mac, len);
        memset(a->value + len, 0, sizeof(a->value) - len);
        a->media_id = b->media->type_id;
        a->broadcast = !memcmp(mac, b->bcast_addr.value, len);
}

int tipc_enable_l2_media(struct tipc_bearer *b)
{
        struct net_device *dev;
        char *driver_name = strchr((const char *)b->name, ':') + 1;

        /* Find device with specified name */
        dev = dev_get_by_name(&init_net, driver_name);
        if (!dev)
                return -ENODEV;

        /* Associate TIPC bearer with Ethernet bearer */
        b->media_ptr = dev;
        memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
        memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
        b->bcast_addr.media_id = b->media->type_id;
        b->bcast_addr.broadcast = 1;
        b->mtu = dev->mtu;
        tipc_l2_media_addr_set(b, &b->addr, (char *)dev->dev_addr);
        rcu_assign_pointer(dev->tipc_ptr, b);
        return 0;
}

/* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
 *
 * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
 * then get worker thread to complete bearer cleanup.  (Can't do cleanup
 * here because cleanup code needs to sleep and caller holds spinlocks.)
 */
void tipc_disable_l2_media(struct tipc_bearer *b)
{
        struct net_device *dev = (struct net_device *)b->media_ptr;
        RCU_INIT_POINTER(dev->tipc_ptr, NULL);
        dev_put(dev);
}

/**
 * tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
 * @buf: the packet to be sent
 * @b_ptr: the bearer through which the packet is to be sent
 * @dest: peer destination address
 */
int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
                     struct tipc_media_addr *dest)
{
        struct sk_buff *clone;
        int delta;
        struct net_device *dev = (struct net_device *)b->media_ptr;

        clone = skb_clone(buf, GFP_ATOMIC);
        if (!clone)
                return 0;

        delta = dev->hard_header_len - skb_headroom(buf);
        if ((delta > 0) &&
            pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
                kfree_skb(clone);
                return 0;
        }

        skb_reset_network_header(clone);
        clone->dev = dev;
        clone->protocol = htons(ETH_P_TIPC);
        dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
                        dev->dev_addr, clone->len);
        dev_queue_xmit(clone);
        return 0;
}

/* tipc_bearer_send- sends buffer to destination over bearer
 *
 * IMPORTANT:
 * The media send routine must not alter the buffer being passed in
 * as it may be needed for later retransmission!
 */
void tipc_bearer_send(struct tipc_bearer *b, struct sk_buff *buf,
                      struct tipc_media_addr *dest)
{
        b->media->send_msg(buf, b, dest);
}

/**
 * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
 * @buf: the received packet
 * @dev: the net device that the packet was received on
 * @pt: the packet_type structure which was used to register this handler
 * @orig_dev: the original receive net device in case the device is a bond
 *
 * Accept only packets explicitly sent to this node, or broadcast packets;
 * ignores packets sent using interface multicast, and traffic sent to other
 * nodes (which can happen if interface is running in promiscuous mode).
 */
static int tipc_l2_rcv_msg(struct sk_buff *buf, struct net_device *dev,
                           struct packet_type *pt, struct net_device *orig_dev)
{
        struct tipc_bearer *b_ptr;

        if (!net_eq(dev_net(dev), &init_net)) {
                kfree_skb(buf);
                return NET_RX_DROP;
        }

        rcu_read_lock();
        b_ptr = rcu_dereference(dev->tipc_ptr);
        if (likely(b_ptr)) {
                if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
                        buf->next = NULL;
                        tipc_rcv(buf, b_ptr);
                        rcu_read_unlock();
                        return NET_RX_SUCCESS;
                }
        }
        rcu_read_unlock();

        kfree_skb(buf);
        return NET_RX_DROP;
}

/**
 * tipc_l2_device_event - handle device events from network device
 * @nb: the context of the notification
 * @evt: the type of event
 * @ptr: the net device that the event was on
 *
 * This function is called by the Ethernet driver in case of link
 * change event.
 */
static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
                                void *ptr)
{
        struct tipc_bearer *b_ptr;
        struct net_device *dev = netdev_notifier_info_to_dev(ptr);

        if (!net_eq(dev_net(dev), &init_net))
                return NOTIFY_DONE;

        rcu_read_lock();
        b_ptr = rcu_dereference(dev->tipc_ptr);
        if (!b_ptr) {
                rcu_read_unlock();
                return NOTIFY_DONE;
        }

        b_ptr->mtu = dev->mtu;

        switch (evt) {
        case NETDEV_CHANGE:
                if (netif_carrier_ok(dev))
                        break;
        case NETDEV_DOWN:
        case NETDEV_CHANGEMTU:
        case NETDEV_CHANGEADDR:
                tipc_reset_bearer(b_ptr);
                break;
        case NETDEV_UNREGISTER:
        case NETDEV_CHANGENAME:
                tipc_disable_bearer(b_ptr->name);
                break;
        }
        rcu_read_unlock();

        return NOTIFY_OK;
}

static struct packet_type tipc_packet_type __read_mostly = {
        .type = __constant_htons(ETH_P_TIPC),
        .func = tipc_l2_rcv_msg,
};

static struct notifier_block notifier = {
        .notifier_call  = tipc_l2_device_event,
        .priority       = 0,
};

int tipc_bearer_setup(void)
{
        int err;

        err = register_netdevice_notifier(&notifier);
        if (err)
                return err;
        dev_add_pack(&tipc_packet_type);
        return 0;
}

void tipc_bearer_cleanup(void)
{
        unregister_netdevice_notifier(&notifier);
        dev_remove_pack(&tipc_packet_type);
}

void tipc_bearer_stop(void)
{
        u32 i;

        for (i = 0; i < MAX_BEARERS; i++) {
                if (tipc_bearers[i].active)
                        bearer_disable(&tipc_bearers[i]);
        }
}