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linux-next/net/batman-adv/main.c
Wedson Almeida Filho aeb193ea6c net: Unmap fragment page once iterator is done
Callers of skb_seq_read() are currently forced to call skb_abort_seq_read()
even when consuming all the data because the last call to skb_seq_read (the
one that returns 0 to indicate the end) fails to unmap the last fragment page.

With this patch callers will be allowed to traverse the SKB data by calling
skb_prepare_seq_read() once and repeatedly calling skb_seq_read() as originally
intended (and documented in the original commit 677e90eda), that is, only call
skb_abort_seq_read() if the sequential read is actually aborted.

Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-24 01:46:01 -07:00

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);
bat_priv->bat_counters = NULL;
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;
}
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);