linux-stable/net/batman-adv/main.c
Sven Eckelmann b91a2543b4 batman-adv: Consume skb in receive handlers
Receiving functions in Linux consume the supplied skbuff. Doing the same in
the batadv_rx_handler functions makes the behavior more similar to the rest
of the Linux network code.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2016-11-08 19:02:34 +01:00

650 lines
18 KiB
C

/* Copyright (C) 2007-2016 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, see <http://www.gnu.org/licenses/>.
*/
#include "main.h"
#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/byteorder/generic.h>
#include <linux/crc32c.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/init.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/printk.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/seq_file.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/workqueue.h>
#include <net/dsfield.h>
#include <net/rtnetlink.h>
#include "bat_algo.h"
#include "bat_iv_ogm.h"
#include "bat_v.h"
#include "bridge_loop_avoidance.h"
#include "debugfs.h"
#include "distributed-arp-table.h"
#include "gateway_client.h"
#include "gateway_common.h"
#include "hard-interface.h"
#include "icmp_socket.h"
#include "log.h"
#include "multicast.h"
#include "netlink.h"
#include "network-coding.h"
#include "originator.h"
#include "packet.h"
#include "routing.h"
#include "send.h"
#include "soft-interface.h"
#include "tp_meter.h"
#include "translation-table.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 *);
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)
{
int ret;
ret = batadv_tt_cache_init();
if (ret < 0)
return ret;
INIT_LIST_HEAD(&batadv_hardif_list);
batadv_algo_init();
batadv_recv_handler_init();
batadv_v_init();
batadv_iv_init();
batadv_nc_init();
batadv_tp_meter_init();
batadv_event_workqueue = create_singlethread_workqueue("bat_events");
if (!batadv_event_workqueue)
goto err_create_wq;
batadv_socket_init();
batadv_debugfs_init();
register_netdevice_notifier(&batadv_hard_if_notifier);
rtnl_link_register(&batadv_link_ops);
batadv_netlink_register();
pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
return 0;
err_create_wq:
batadv_tt_cache_destroy();
return -ENOMEM;
}
static void __exit batadv_exit(void)
{
batadv_debugfs_destroy();
batadv_netlink_unregister();
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();
batadv_tt_cache_destroy();
}
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->tt.commit_lock);
spin_lock_init(&bat_priv->gw.list_lock);
#ifdef CONFIG_BATMAN_ADV_MCAST
spin_lock_init(&bat_priv->mcast.want_lists_lock);
#endif
spin_lock_init(&bat_priv->tvlv.container_list_lock);
spin_lock_init(&bat_priv->tvlv.handler_list_lock);
spin_lock_init(&bat_priv->softif_vlan_list_lock);
spin_lock_init(&bat_priv->tp_list_lock);
INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
INIT_HLIST_HEAD(&bat_priv->gw.gateway_list);
#ifdef CONFIG_BATMAN_ADV_MCAST
INIT_HLIST_HEAD(&bat_priv->mcast.want_all_unsnoopables_list);
INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv4_list);
INIT_HLIST_HEAD(&bat_priv->mcast.want_all_ipv6_list);
#endif
INIT_LIST_HEAD(&bat_priv->tt.changes_list);
INIT_HLIST_HEAD(&bat_priv->tt.req_list);
INIT_LIST_HEAD(&bat_priv->tt.roam_list);
#ifdef CONFIG_BATMAN_ADV_MCAST
INIT_HLIST_HEAD(&bat_priv->mcast.mla_list);
#endif
INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
INIT_HLIST_HEAD(&bat_priv->softif_vlan_list);
INIT_HLIST_HEAD(&bat_priv->tp_list);
ret = batadv_v_mesh_init(bat_priv);
if (ret < 0)
goto err;
ret = batadv_originator_init(bat_priv);
if (ret < 0)
goto err;
ret = batadv_tt_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_mesh_init(bat_priv);
if (ret < 0)
goto err;
batadv_gw_init(bat_priv);
batadv_mcast_init(bat_priv);
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_gw_node_free(bat_priv);
batadv_v_mesh_free(bat_priv);
batadv_nc_mesh_free(bat_priv);
batadv_dat_free(bat_priv);
batadv_bla_free(bat_priv);
batadv_mcast_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);
batadv_gw_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
*
* Return: 'true' if the mac address was found, false otherwise.
*/
bool batadv_is_my_mac(struct batadv_priv *bat_priv, const u8 *addr)
{
const struct batadv_hard_iface *hard_iface;
bool is_my_mac = false;
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)) {
is_my_mac = true;
break;
}
}
rcu_read_unlock();
return is_my_mac;
}
#ifdef CONFIG_BATMAN_ADV_DEBUGFS
/**
* batadv_seq_print_text_primary_if_get - called from debugfs table printing
* function that requires the primary interface
* @seq: debugfs table seq_file struct
*
* Return: 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_put(primary_if);
primary_if = NULL;
out:
return primary_if;
}
#endif
/**
* batadv_max_header_len - calculate maximum encapsulation overhead for a
* payload packet
*
* Return: the maximum encapsulation overhead in bytes.
*/
int batadv_max_header_len(void)
{
int header_len = 0;
header_len = max_t(int, header_len,
sizeof(struct batadv_unicast_packet));
header_len = max_t(int, header_len,
sizeof(struct batadv_unicast_4addr_packet));
header_len = max_t(int, header_len,
sizeof(struct batadv_bcast_packet));
#ifdef CONFIG_BATMAN_ADV_NC
header_len = max_t(int, header_len,
sizeof(struct batadv_coded_packet));
#endif
return header_len + ETH_HLEN;
}
/**
* batadv_skb_set_priority - sets skb priority according to packet content
* @skb: the packet to be sent
* @offset: offset to the packet content
*
* This function sets a value between 256 and 263 (802.1d priority), which
* can be interpreted by the cfg80211 or other drivers.
*/
void batadv_skb_set_priority(struct sk_buff *skb, int offset)
{
struct iphdr ip_hdr_tmp, *ip_hdr;
struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
struct ethhdr ethhdr_tmp, *ethhdr;
struct vlan_ethhdr *vhdr, vhdr_tmp;
u32 prio;
/* already set, do nothing */
if (skb->priority >= 256 && skb->priority <= 263)
return;
ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), &ethhdr_tmp);
if (!ethhdr)
return;
switch (ethhdr->h_proto) {
case htons(ETH_P_8021Q):
vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
sizeof(*vhdr), &vhdr_tmp);
if (!vhdr)
return;
prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
prio = prio >> VLAN_PRIO_SHIFT;
break;
case htons(ETH_P_IP):
ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
sizeof(*ip_hdr), &ip_hdr_tmp);
if (!ip_hdr)
return;
prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
break;
case htons(ETH_P_IPV6):
ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
sizeof(*ip6_hdr), &ip6_hdr_tmp);
if (!ip6_hdr)
return;
prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
break;
default:
return;
}
skb->priority = prio + 256;
}
static int batadv_recv_unhandled_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
kfree_skb(skb);
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;
u8 idx;
hard_iface = container_of(ptype, struct batadv_hard_iface,
batman_adv_ptype);
/* Prevent processing a packet received on an interface which is getting
* shut down otherwise the packet may trigger de-reference errors
* further down in the receive path.
*/
if (!kref_get_unless_zero(&hard_iface->refcount))
goto err_out;
skb = skb_share_check(skb, GFP_ATOMIC);
/* skb was released by skb_share_check() */
if (!skb)
goto err_put;
/* 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->version != BATADV_COMPAT_VERSION) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Drop packet: incompatible batman version (%i)\n",
batadv_ogm_packet->version);
goto err_free;
}
/* reset control block to avoid left overs from previous users */
memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
idx = batadv_ogm_packet->packet_type;
(*batadv_rx_handler[idx])(skb, hard_iface);
batadv_hardif_put(hard_iface);
/* 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_put:
batadv_hardif_put(hard_iface);
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;
for (i = BATADV_UNICAST_MIN; i <= BATADV_UNICAST_MAX; i++)
batadv_rx_handler[i] = batadv_recv_unhandled_unicast_packet;
/* compile time checks for sizes */
BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6);
BUILD_BUG_ON(sizeof(struct batadv_ogm_packet) != 24);
BUILD_BUG_ON(sizeof(struct batadv_icmp_header) != 20);
BUILD_BUG_ON(sizeof(struct batadv_icmp_packet) != 20);
BUILD_BUG_ON(sizeof(struct batadv_icmp_packet_rr) != 116);
BUILD_BUG_ON(sizeof(struct batadv_unicast_packet) != 10);
BUILD_BUG_ON(sizeof(struct batadv_unicast_4addr_packet) != 18);
BUILD_BUG_ON(sizeof(struct batadv_frag_packet) != 20);
BUILD_BUG_ON(sizeof(struct batadv_bcast_packet) != 14);
BUILD_BUG_ON(sizeof(struct batadv_coded_packet) != 46);
BUILD_BUG_ON(sizeof(struct batadv_unicast_tvlv_packet) != 20);
BUILD_BUG_ON(sizeof(struct batadv_tvlv_hdr) != 4);
BUILD_BUG_ON(sizeof(struct batadv_tvlv_gateway_data) != 8);
BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_vlan_data) != 8);
BUILD_BUG_ON(sizeof(struct batadv_tvlv_tt_change) != 12);
BUILD_BUG_ON(sizeof(struct batadv_tvlv_roam_adv) != 8);
/* broadcast packet */
batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
/* unicast packets ... */
/* 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;
/* unicast tvlv packet */
batadv_rx_handler[BATADV_UNICAST_TVLV] = batadv_recv_unicast_tvlv;
/* batman icmp packet */
batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
/* Fragmented packets */
batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_frag_packet;
}
int
batadv_recv_handler_register(u8 packet_type,
int (*recv_handler)(struct sk_buff *,
struct batadv_hard_iface *))
{
int (*curr)(struct sk_buff *,
struct batadv_hard_iface *);
curr = batadv_rx_handler[packet_type];
if ((curr != batadv_recv_unhandled_packet) &&
(curr != batadv_recv_unhandled_unicast_packet))
return -EBUSY;
batadv_rx_handler[packet_type] = recv_handler;
return 0;
}
void batadv_recv_handler_unregister(u8 packet_type)
{
batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
}
/**
* 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.
*
* Return: big endian crc32c of the checksummed data
*/
__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);
}
/**
* batadv_get_vid - extract the VLAN identifier from skb if any
* @skb: the buffer containing the packet
* @header_len: length of the batman header preceding the ethernet header
*
* Return: VID with the BATADV_VLAN_HAS_TAG flag when the packet embedded in the
* skb is vlan tagged. Otherwise BATADV_NO_FLAGS.
*/
unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len)
{
struct ethhdr *ethhdr = (struct ethhdr *)(skb->data + header_len);
struct vlan_ethhdr *vhdr;
unsigned short vid;
if (ethhdr->h_proto != htons(ETH_P_8021Q))
return BATADV_NO_FLAGS;
if (!pskb_may_pull(skb, header_len + VLAN_ETH_HLEN))
return BATADV_NO_FLAGS;
vhdr = (struct vlan_ethhdr *)(skb->data + header_len);
vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
vid |= BATADV_VLAN_HAS_TAG;
return vid;
}
/**
* batadv_vlan_ap_isola_get - return the AP isolation status for the given vlan
* @bat_priv: the bat priv with all the soft interface information
* @vid: the VLAN identifier for which the AP isolation attributed as to be
* looked up
*
* Return: true if AP isolation is on for the VLAN idenfied by vid, false
* otherwise
*/
bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid)
{
bool ap_isolation_enabled = false;
struct batadv_softif_vlan *vlan;
/* if the AP isolation is requested on a VLAN, then check for its
* setting in the proper VLAN private data structure
*/
vlan = batadv_softif_vlan_get(bat_priv, vid);
if (vlan) {
ap_isolation_enabled = atomic_read(&vlan->ap_isolation);
batadv_softif_vlan_put(vlan);
}
return ap_isolation_enabled;
}
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);
MODULE_ALIAS_RTNL_LINK("batadv");