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linux-next/net/batman-adv/main.c
Antonio Quartulli a436186035 batman-adv: reorder clean up routine in order to avoid race conditions
nc_worker accesses the originator table during its periodic
work, but since the originator table is freed before
stopping the worker this leads to a global protection fault.

Fix this by killing the worker (in nc_free) before freeing
the originator table.

Moreover tidy up the entire clean up routine by running all
the subcomponents freeing procedures first and then killing
the TT and the originator tables at the end.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-05-09 12:39:45 +02:00

519 lines
13 KiB
C

/* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*/
#include <linux/crc32c.h>
#include <linux/highmem.h>
#include "main.h"
#include "sysfs.h"
#include "debugfs.h"
#include "routing.h"
#include "send.h"
#include "originator.h"
#include "soft-interface.h"
#include "icmp_socket.h"
#include "translation-table.h"
#include "hard-interface.h"
#include "gateway_client.h"
#include "bridge_loop_avoidance.h"
#include "distributed-arp-table.h"
#include "vis.h"
#include "hash.h"
#include "bat_algo.h"
#include "network-coding.h"
/* List manipulations on hardif_list have to be rtnl_lock()'ed,
* list traversals just rcu-locked
*/
struct list_head batadv_hardif_list;
static int (*batadv_rx_handler[256])(struct sk_buff *,
struct batadv_hard_iface *);
char batadv_routing_algo[20] = "BATMAN_IV";
static struct hlist_head batadv_algo_list;
unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
struct workqueue_struct *batadv_event_workqueue;
static void batadv_recv_handler_init(void);
static int __init batadv_init(void)
{
INIT_LIST_HEAD(&batadv_hardif_list);
INIT_HLIST_HEAD(&batadv_algo_list);
batadv_recv_handler_init();
batadv_iv_init();
batadv_event_workqueue = create_singlethread_workqueue("bat_events");
if (!batadv_event_workqueue)
return -ENOMEM;
batadv_socket_init();
batadv_debugfs_init();
register_netdevice_notifier(&batadv_hard_if_notifier);
rtnl_link_register(&batadv_link_ops);
pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
return 0;
}
static void __exit batadv_exit(void)
{
batadv_debugfs_destroy();
rtnl_link_unregister(&batadv_link_ops);
unregister_netdevice_notifier(&batadv_hard_if_notifier);
batadv_hardif_remove_interfaces();
flush_workqueue(batadv_event_workqueue);
destroy_workqueue(batadv_event_workqueue);
batadv_event_workqueue = NULL;
rcu_barrier();
}
int batadv_mesh_init(struct net_device *soft_iface)
{
struct batadv_priv *bat_priv = netdev_priv(soft_iface);
int ret;
spin_lock_init(&bat_priv->forw_bat_list_lock);
spin_lock_init(&bat_priv->forw_bcast_list_lock);
spin_lock_init(&bat_priv->tt.changes_list_lock);
spin_lock_init(&bat_priv->tt.req_list_lock);
spin_lock_init(&bat_priv->tt.roam_list_lock);
spin_lock_init(&bat_priv->tt.last_changeset_lock);
spin_lock_init(&bat_priv->gw.list_lock);
spin_lock_init(&bat_priv->vis.hash_lock);
spin_lock_init(&bat_priv->vis.list_lock);
INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
INIT_HLIST_HEAD(&bat_priv->gw.list);
INIT_LIST_HEAD(&bat_priv->tt.changes_list);
INIT_LIST_HEAD(&bat_priv->tt.req_list);
INIT_LIST_HEAD(&bat_priv->tt.roam_list);
ret = batadv_originator_init(bat_priv);
if (ret < 0)
goto err;
ret = batadv_tt_init(bat_priv);
if (ret < 0)
goto err;
batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
BATADV_NULL_IFINDEX);
ret = batadv_vis_init(bat_priv);
if (ret < 0)
goto err;
ret = batadv_bla_init(bat_priv);
if (ret < 0)
goto err;
ret = batadv_dat_init(bat_priv);
if (ret < 0)
goto err;
ret = batadv_nc_init(bat_priv);
if (ret < 0)
goto err;
atomic_set(&bat_priv->gw.reselect, 0);
atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
return 0;
err:
batadv_mesh_free(soft_iface);
return ret;
}
void batadv_mesh_free(struct net_device *soft_iface)
{
struct batadv_priv *bat_priv = netdev_priv(soft_iface);
atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
batadv_purge_outstanding_packets(bat_priv, NULL);
batadv_vis_quit(bat_priv);
batadv_gw_node_purge(bat_priv);
batadv_nc_free(bat_priv);
batadv_dat_free(bat_priv);
batadv_bla_free(bat_priv);
/* Free the TT and the originator tables only after having terminated
* all the other depending components which may use these structures for
* their purposes.
*/
batadv_tt_free(bat_priv);
/* Since the originator table clean up routine is accessing the TT
* tables as well, it has to be invoked after the TT tables have been
* freed and marked as empty. This ensures that no cleanup RCU callbacks
* accessing the TT data are scheduled for later execution.
*/
batadv_originator_free(bat_priv);
free_percpu(bat_priv->bat_counters);
atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
}
/**
* batadv_is_my_mac - check if the given mac address belongs to any of the real
* interfaces in the current mesh
* @bat_priv: the bat priv with all the soft interface information
* @addr: the address to check
*/
int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
{
const struct batadv_hard_iface *hard_iface;
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
if (hard_iface->if_status != BATADV_IF_ACTIVE)
continue;
if (hard_iface->soft_iface != bat_priv->soft_iface)
continue;
if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
rcu_read_unlock();
return 1;
}
}
rcu_read_unlock();
return 0;
}
/**
* batadv_seq_print_text_primary_if_get - called from debugfs table printing
* function that requires the primary interface
* @seq: debugfs table seq_file struct
*
* Returns primary interface if found or NULL otherwise.
*/
struct batadv_hard_iface *
batadv_seq_print_text_primary_if_get(struct seq_file *seq)
{
struct net_device *net_dev = (struct net_device *)seq->private;
struct batadv_priv *bat_priv = netdev_priv(net_dev);
struct batadv_hard_iface *primary_if;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if) {
seq_printf(seq,
"BATMAN mesh %s disabled - please specify interfaces to enable it\n",
net_dev->name);
goto out;
}
if (primary_if->if_status == BATADV_IF_ACTIVE)
goto out;
seq_printf(seq,
"BATMAN mesh %s disabled - primary interface not active\n",
net_dev->name);
batadv_hardif_free_ref(primary_if);
primary_if = NULL;
out:
return primary_if;
}
static int batadv_recv_unhandled_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
return NET_RX_DROP;
}
/* incoming packets with the batman ethertype received on any active hard
* interface
*/
int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *ptype,
struct net_device *orig_dev)
{
struct batadv_priv *bat_priv;
struct batadv_ogm_packet *batadv_ogm_packet;
struct batadv_hard_iface *hard_iface;
uint8_t idx;
int ret;
hard_iface = container_of(ptype, struct batadv_hard_iface,
batman_adv_ptype);
skb = skb_share_check(skb, GFP_ATOMIC);
/* skb was released by skb_share_check() */
if (!skb)
goto err_out;
/* packet should hold at least type and version */
if (unlikely(!pskb_may_pull(skb, 2)))
goto err_free;
/* expect a valid ethernet header here. */
if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
goto err_free;
if (!hard_iface->soft_iface)
goto err_free;
bat_priv = netdev_priv(hard_iface->soft_iface);
if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
goto err_free;
/* discard frames on not active interfaces */
if (hard_iface->if_status != BATADV_IF_ACTIVE)
goto err_free;
batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Drop packet: incompatible batman version (%i)\n",
batadv_ogm_packet->header.version);
goto err_free;
}
/* all receive handlers return whether they received or reused
* the supplied skb. if not, we have to free the skb.
*/
idx = batadv_ogm_packet->header.packet_type;
ret = (*batadv_rx_handler[idx])(skb, hard_iface);
if (ret == NET_RX_DROP)
kfree_skb(skb);
/* return NET_RX_SUCCESS in any case as we
* most probably dropped the packet for
* routing-logical reasons.
*/
return NET_RX_SUCCESS;
err_free:
kfree_skb(skb);
err_out:
return NET_RX_DROP;
}
static void batadv_recv_handler_init(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
batadv_rx_handler[i] = batadv_recv_unhandled_packet;
/* batman icmp packet */
batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
/* unicast with 4 addresses packet */
batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
/* unicast packet */
batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
/* fragmented unicast packet */
batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
/* broadcast packet */
batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
/* vis packet */
batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
/* Translation table query (request or response) */
batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
/* Roaming advertisement */
batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
}
int
batadv_recv_handler_register(uint8_t packet_type,
int (*recv_handler)(struct sk_buff *,
struct batadv_hard_iface *))
{
if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
return -EBUSY;
batadv_rx_handler[packet_type] = recv_handler;
return 0;
}
void batadv_recv_handler_unregister(uint8_t packet_type)
{
batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
}
static struct batadv_algo_ops *batadv_algo_get(char *name)
{
struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
if (strcmp(bat_algo_ops_tmp->name, name) != 0)
continue;
bat_algo_ops = bat_algo_ops_tmp;
break;
}
return bat_algo_ops;
}
int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
{
struct batadv_algo_ops *bat_algo_ops_tmp;
int ret;
bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
if (bat_algo_ops_tmp) {
pr_info("Trying to register already registered routing algorithm: %s\n",
bat_algo_ops->name);
ret = -EEXIST;
goto out;
}
/* all algorithms must implement all ops (for now) */
if (!bat_algo_ops->bat_iface_enable ||
!bat_algo_ops->bat_iface_disable ||
!bat_algo_ops->bat_iface_update_mac ||
!bat_algo_ops->bat_primary_iface_set ||
!bat_algo_ops->bat_ogm_schedule ||
!bat_algo_ops->bat_ogm_emit) {
pr_info("Routing algo '%s' does not implement required ops\n",
bat_algo_ops->name);
ret = -EINVAL;
goto out;
}
INIT_HLIST_NODE(&bat_algo_ops->list);
hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
ret = 0;
out:
return ret;
}
int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
{
struct batadv_algo_ops *bat_algo_ops;
int ret = -EINVAL;
bat_algo_ops = batadv_algo_get(name);
if (!bat_algo_ops)
goto out;
bat_priv->bat_algo_ops = bat_algo_ops;
ret = 0;
out:
return ret;
}
int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
{
struct batadv_algo_ops *bat_algo_ops;
seq_puts(seq, "Available routing algorithms:\n");
hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
seq_printf(seq, "%s\n", bat_algo_ops->name);
}
return 0;
}
/**
* batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
* the header
* @skb: skb pointing to fragmented socket buffers
* @payload_ptr: Pointer to position inside the head buffer of the skb
* marking the start of the data to be CRC'ed
*
* payload_ptr must always point to an address in the skb head buffer and not to
* a fragment.
*/
__be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
{
u32 crc = 0;
unsigned int from;
unsigned int to = skb->len;
struct skb_seq_state st;
const u8 *data;
unsigned int len;
unsigned int consumed = 0;
from = (unsigned int)(payload_ptr - skb->data);
skb_prepare_seq_read(skb, from, to, &st);
while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
crc = crc32c(crc, data, len);
consumed += len;
}
skb_abort_seq_read(&st);
return htonl(crc);
}
static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
{
struct batadv_algo_ops *bat_algo_ops;
char *algo_name = (char *)val;
size_t name_len = strlen(algo_name);
if (name_len > 0 && algo_name[name_len - 1] == '\n')
algo_name[name_len - 1] = '\0';
bat_algo_ops = batadv_algo_get(algo_name);
if (!bat_algo_ops) {
pr_err("Routing algorithm '%s' is not supported\n", algo_name);
return -EINVAL;
}
return param_set_copystring(algo_name, kp);
}
static const struct kernel_param_ops batadv_param_ops_ra = {
.set = batadv_param_set_ra,
.get = param_get_string,
};
static struct kparam_string batadv_param_string_ra = {
.maxlen = sizeof(batadv_routing_algo),
.string = batadv_routing_algo,
};
module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
0644);
module_init(batadv_init);
module_exit(batadv_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
MODULE_VERSION(BATADV_SOURCE_VERSION);