linux/net/mac80211/mesh_pathtbl.c
Linus Torvalds 3b59bf0816 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking merge from David Miller:
 "1) Move ixgbe driver over to purely page based buffering on receive.
     From Alexander Duyck.

  2) Add receive packet steering support to e1000e, from Bruce Allan.

  3) Convert TCP MD5 support over to RCU, from Eric Dumazet.

  4) Reduce cpu usage in handling out-of-order TCP packets on modern
     systems, also from Eric Dumazet.

  5) Support the IP{,V6}_UNICAST_IF socket options, making the wine
     folks happy, from Erich Hoover.

  6) Support VLAN trunking from guests in hyperv driver, from Haiyang
     Zhang.

  7) Support byte-queue-limtis in r8169, from Igor Maravic.

  8) Outline code intended for IP_RECVTOS in IP_PKTOPTIONS existed but
     was never properly implemented, Jiri Benc fixed that.

  9) 64-bit statistics support in r8169 and 8139too, from Junchang Wang.

  10) Support kernel side dump filtering by ctmark in netfilter
      ctnetlink, from Pablo Neira Ayuso.

  11) Support byte-queue-limits in gianfar driver, from Paul Gortmaker.

  12) Add new peek socket options to assist with socket migration, from
      Pavel Emelyanov.

  13) Add sch_plug packet scheduler whose queue is controlled by
      userland daemons using explicit freeze and release commands.  From
      Shriram Rajagopalan.

  14) Fix FCOE checksum offload handling on transmit, from Yi Zou."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1846 commits)
  Fix pppol2tp getsockname()
  Remove printk from rds_sendmsg
  ipv6: fix incorrent ipv6 ipsec packet fragment
  cpsw: Hook up default ndo_change_mtu.
  net: qmi_wwan: fix build error due to cdc-wdm dependecy
  netdev: driver: ethernet: Add TI CPSW driver
  netdev: driver: ethernet: add cpsw address lookup engine support
  phy: add am79c874 PHY support
  mlx4_core: fix race on comm channel
  bonding: send igmp report for its master
  fs_enet: Add MPC5125 FEC support and PHY interface selection
  net: bpf_jit: fix BPF_S_LDX_B_MSH compilation
  net: update the usage of CHECKSUM_UNNECESSARY
  fcoe: use CHECKSUM_UNNECESSARY instead of CHECKSUM_PARTIAL on tx
  net: do not do gso for CHECKSUM_UNNECESSARY in netif_needs_gso
  ixgbe: Fix issues with SR-IOV loopback when flow control is disabled
  net/hyperv: Fix the code handling tx busy
  ixgbe: fix namespace issues when FCoE/DCB is not enabled
  rtlwifi: Remove unused ETH_ADDR_LEN defines
  igbvf: Use ETH_ALEN
  ...

Fix up fairly trivial conflicts in drivers/isdn/gigaset/interface.c and
drivers/net/usb/{Kconfig,qmi_wwan.c} as per David.
2012-03-20 21:04:47 -07:00

1125 lines
29 KiB
C

/*
* Copyright (c) 2008, 2009 open80211s Ltd.
* Author: Luis Carlos Cobo <luisca@cozybit.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <net/mac80211.h>
#include "wme.h"
#include "ieee80211_i.h"
#include "mesh.h"
#ifdef CONFIG_MAC80211_VERBOSE_MPATH_DEBUG
#define mpath_dbg(fmt, args...) printk(KERN_DEBUG fmt, ##args)
#else
#define mpath_dbg(fmt, args...) do { (void)(0); } while (0)
#endif
/* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */
#define INIT_PATHS_SIZE_ORDER 2
/* Keep the mean chain length below this constant */
#define MEAN_CHAIN_LEN 2
#define MPATH_EXPIRED(mpath) ((mpath->flags & MESH_PATH_ACTIVE) && \
time_after(jiffies, mpath->exp_time) && \
!(mpath->flags & MESH_PATH_FIXED))
struct mpath_node {
struct hlist_node list;
struct rcu_head rcu;
/* This indirection allows two different tables to point to the same
* mesh_path structure, useful when resizing
*/
struct mesh_path *mpath;
};
static struct mesh_table __rcu *mesh_paths;
static struct mesh_table __rcu *mpp_paths; /* Store paths for MPP&MAP */
int mesh_paths_generation;
/* This lock will have the grow table function as writer and add / delete nodes
* as readers. RCU provides sufficient protection only when reading the table
* (i.e. doing lookups). Adding or adding or removing nodes requires we take
* the read lock or we risk operating on an old table. The write lock is only
* needed when modifying the number of buckets a table.
*/
static DEFINE_RWLOCK(pathtbl_resize_lock);
static inline struct mesh_table *resize_dereference_mesh_paths(void)
{
return rcu_dereference_protected(mesh_paths,
lockdep_is_held(&pathtbl_resize_lock));
}
static inline struct mesh_table *resize_dereference_mpp_paths(void)
{
return rcu_dereference_protected(mpp_paths,
lockdep_is_held(&pathtbl_resize_lock));
}
/*
* CAREFUL -- "tbl" must not be an expression,
* in particular not an rcu_dereference(), since
* it's used twice. So it is illegal to do
* for_each_mesh_entry(rcu_dereference(...), ...)
*/
#define for_each_mesh_entry(tbl, p, node, i) \
for (i = 0; i <= tbl->hash_mask; i++) \
hlist_for_each_entry_rcu(node, p, &tbl->hash_buckets[i], list)
static struct mesh_table *mesh_table_alloc(int size_order)
{
int i;
struct mesh_table *newtbl;
newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
if (!newtbl)
return NULL;
newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
(1 << size_order), GFP_ATOMIC);
if (!newtbl->hash_buckets) {
kfree(newtbl);
return NULL;
}
newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
(1 << size_order), GFP_ATOMIC);
if (!newtbl->hashwlock) {
kfree(newtbl->hash_buckets);
kfree(newtbl);
return NULL;
}
newtbl->size_order = size_order;
newtbl->hash_mask = (1 << size_order) - 1;
atomic_set(&newtbl->entries, 0);
get_random_bytes(&newtbl->hash_rnd,
sizeof(newtbl->hash_rnd));
for (i = 0; i <= newtbl->hash_mask; i++)
spin_lock_init(&newtbl->hashwlock[i]);
spin_lock_init(&newtbl->gates_lock);
return newtbl;
}
static void __mesh_table_free(struct mesh_table *tbl)
{
kfree(tbl->hash_buckets);
kfree(tbl->hashwlock);
kfree(tbl);
}
static void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
{
struct hlist_head *mesh_hash;
struct hlist_node *p, *q;
struct mpath_node *gate;
int i;
mesh_hash = tbl->hash_buckets;
for (i = 0; i <= tbl->hash_mask; i++) {
spin_lock_bh(&tbl->hashwlock[i]);
hlist_for_each_safe(p, q, &mesh_hash[i]) {
tbl->free_node(p, free_leafs);
atomic_dec(&tbl->entries);
}
spin_unlock_bh(&tbl->hashwlock[i]);
}
if (free_leafs) {
spin_lock_bh(&tbl->gates_lock);
hlist_for_each_entry_safe(gate, p, q,
tbl->known_gates, list) {
hlist_del(&gate->list);
kfree(gate);
}
kfree(tbl->known_gates);
spin_unlock_bh(&tbl->gates_lock);
}
__mesh_table_free(tbl);
}
static int mesh_table_grow(struct mesh_table *oldtbl,
struct mesh_table *newtbl)
{
struct hlist_head *oldhash;
struct hlist_node *p, *q;
int i;
if (atomic_read(&oldtbl->entries)
< oldtbl->mean_chain_len * (oldtbl->hash_mask + 1))
return -EAGAIN;
newtbl->free_node = oldtbl->free_node;
newtbl->mean_chain_len = oldtbl->mean_chain_len;
newtbl->copy_node = oldtbl->copy_node;
newtbl->known_gates = oldtbl->known_gates;
atomic_set(&newtbl->entries, atomic_read(&oldtbl->entries));
oldhash = oldtbl->hash_buckets;
for (i = 0; i <= oldtbl->hash_mask; i++)
hlist_for_each(p, &oldhash[i])
if (oldtbl->copy_node(p, newtbl) < 0)
goto errcopy;
return 0;
errcopy:
for (i = 0; i <= newtbl->hash_mask; i++) {
hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
oldtbl->free_node(p, 0);
}
return -ENOMEM;
}
static u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
struct mesh_table *tbl)
{
/* Use last four bytes of hw addr and interface index as hash index */
return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex, tbl->hash_rnd)
& tbl->hash_mask;
}
/**
*
* mesh_path_assign_nexthop - update mesh path next hop
*
* @mpath: mesh path to update
* @sta: next hop to assign
*
* Locking: mpath->state_lock must be held when calling this function
*/
void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
{
struct sk_buff *skb;
struct ieee80211_hdr *hdr;
struct sk_buff_head tmpq;
unsigned long flags;
rcu_assign_pointer(mpath->next_hop, sta);
__skb_queue_head_init(&tmpq);
spin_lock_irqsave(&mpath->frame_queue.lock, flags);
while ((skb = __skb_dequeue(&mpath->frame_queue)) != NULL) {
hdr = (struct ieee80211_hdr *) skb->data;
memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN);
__skb_queue_tail(&tmpq, skb);
}
skb_queue_splice(&tmpq, &mpath->frame_queue);
spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
}
static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
struct mesh_path *gate_mpath)
{
struct ieee80211_hdr *hdr;
struct ieee80211s_hdr *mshdr;
int mesh_hdrlen, hdrlen;
char *next_hop;
hdr = (struct ieee80211_hdr *) skb->data;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
if (!(mshdr->flags & MESH_FLAGS_AE)) {
/* size of the fixed part of the mesh header */
mesh_hdrlen = 6;
/* make room for the two extended addresses */
skb_push(skb, 2 * ETH_ALEN);
memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
hdr = (struct ieee80211_hdr *) skb->data;
/* we preserve the previous mesh header and only add
* the new addreses */
mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
mshdr->flags = MESH_FLAGS_AE_A5_A6;
memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
}
/* update next hop */
hdr = (struct ieee80211_hdr *) skb->data;
rcu_read_lock();
next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
memcpy(hdr->addr1, next_hop, ETH_ALEN);
rcu_read_unlock();
memcpy(hdr->addr2, gate_mpath->sdata->vif.addr, ETH_ALEN);
memcpy(hdr->addr3, dst_addr, ETH_ALEN);
}
/**
*
* mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
*
* This function is used to transfer or copy frames from an unresolved mpath to
* a gate mpath. The function also adds the Address Extension field and
* updates the next hop.
*
* If a frame already has an Address Extension field, only the next hop and
* destination addresses are updated.
*
* The gate mpath must be an active mpath with a valid mpath->next_hop.
*
* @mpath: An active mpath the frames will be sent to (i.e. the gate)
* @from_mpath: The failed mpath
* @copy: When true, copy all the frames to the new mpath queue. When false,
* move them.
*/
static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
struct mesh_path *from_mpath,
bool copy)
{
struct sk_buff *skb, *cp_skb = NULL;
struct sk_buff_head gateq, failq;
unsigned long flags;
int num_skbs;
BUG_ON(gate_mpath == from_mpath);
BUG_ON(!gate_mpath->next_hop);
__skb_queue_head_init(&gateq);
__skb_queue_head_init(&failq);
spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
skb_queue_splice_init(&from_mpath->frame_queue, &failq);
spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
num_skbs = skb_queue_len(&failq);
while (num_skbs--) {
skb = __skb_dequeue(&failq);
if (copy) {
cp_skb = skb_copy(skb, GFP_ATOMIC);
if (cp_skb)
__skb_queue_tail(&failq, cp_skb);
}
prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
__skb_queue_tail(&gateq, skb);
}
spin_lock_irqsave(&gate_mpath->frame_queue.lock, flags);
skb_queue_splice(&gateq, &gate_mpath->frame_queue);
mpath_dbg("Mpath queue for gate %pM has %d frames\n",
gate_mpath->dst,
skb_queue_len(&gate_mpath->frame_queue));
spin_unlock_irqrestore(&gate_mpath->frame_queue.lock, flags);
if (!copy)
return;
spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
skb_queue_splice(&failq, &from_mpath->frame_queue);
spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
}
static struct mesh_path *mpath_lookup(struct mesh_table *tbl, u8 *dst,
struct ieee80211_sub_if_data *sdata)
{
struct mesh_path *mpath;
struct hlist_node *n;
struct hlist_head *bucket;
struct mpath_node *node;
bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
hlist_for_each_entry_rcu(node, n, bucket, list) {
mpath = node->mpath;
if (mpath->sdata == sdata &&
compare_ether_addr(dst, mpath->dst) == 0) {
if (MPATH_EXPIRED(mpath)) {
spin_lock_bh(&mpath->state_lock);
mpath->flags &= ~MESH_PATH_ACTIVE;
spin_unlock_bh(&mpath->state_lock);
}
return mpath;
}
}
return NULL;
}
/**
* mesh_path_lookup - look up a path in the mesh path table
* @dst: hardware address (ETH_ALEN length) of destination
* @sdata: local subif
*
* Returns: pointer to the mesh path structure, or NULL if not found
*
* Locking: must be called within a read rcu section.
*/
struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
{
return mpath_lookup(rcu_dereference(mesh_paths), dst, sdata);
}
struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
{
return mpath_lookup(rcu_dereference(mpp_paths), dst, sdata);
}
/**
* mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
* @idx: index
* @sdata: local subif, or NULL for all entries
*
* Returns: pointer to the mesh path structure, or NULL if not found.
*
* Locking: must be called within a read rcu section.
*/
struct mesh_path *mesh_path_lookup_by_idx(int idx, struct ieee80211_sub_if_data *sdata)
{
struct mesh_table *tbl = rcu_dereference(mesh_paths);
struct mpath_node *node;
struct hlist_node *p;
int i;
int j = 0;
for_each_mesh_entry(tbl, p, node, i) {
if (sdata && node->mpath->sdata != sdata)
continue;
if (j++ == idx) {
if (MPATH_EXPIRED(node->mpath)) {
spin_lock_bh(&node->mpath->state_lock);
node->mpath->flags &= ~MESH_PATH_ACTIVE;
spin_unlock_bh(&node->mpath->state_lock);
}
return node->mpath;
}
}
return NULL;
}
/**
* mesh_path_add_gate - add the given mpath to a mesh gate to our path table
* @mpath: gate path to add to table
*/
int mesh_path_add_gate(struct mesh_path *mpath)
{
struct mesh_table *tbl;
struct mpath_node *gate, *new_gate;
struct hlist_node *n;
int err;
rcu_read_lock();
tbl = rcu_dereference(mesh_paths);
hlist_for_each_entry_rcu(gate, n, tbl->known_gates, list)
if (gate->mpath == mpath) {
err = -EEXIST;
goto err_rcu;
}
new_gate = kzalloc(sizeof(struct mpath_node), GFP_ATOMIC);
if (!new_gate) {
err = -ENOMEM;
goto err_rcu;
}
mpath->is_gate = true;
mpath->sdata->u.mesh.num_gates++;
new_gate->mpath = mpath;
spin_lock_bh(&tbl->gates_lock);
hlist_add_head_rcu(&new_gate->list, tbl->known_gates);
spin_unlock_bh(&tbl->gates_lock);
rcu_read_unlock();
mpath_dbg("Mesh path (%s): Recorded new gate: %pM. %d known gates\n",
mpath->sdata->name, mpath->dst,
mpath->sdata->u.mesh.num_gates);
return 0;
err_rcu:
rcu_read_unlock();
return err;
}
/**
* mesh_gate_del - remove a mesh gate from the list of known gates
* @tbl: table which holds our list of known gates
* @mpath: gate mpath
*
* Returns: 0 on success
*
* Locking: must be called inside rcu_read_lock() section
*/
static int mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
{
struct mpath_node *gate;
struct hlist_node *p, *q;
hlist_for_each_entry_safe(gate, p, q, tbl->known_gates, list)
if (gate->mpath == mpath) {
spin_lock_bh(&tbl->gates_lock);
hlist_del_rcu(&gate->list);
kfree_rcu(gate, rcu);
spin_unlock_bh(&tbl->gates_lock);
mpath->sdata->u.mesh.num_gates--;
mpath->is_gate = false;
mpath_dbg("Mesh path (%s): Deleted gate: %pM. "
"%d known gates\n", mpath->sdata->name,
mpath->dst, mpath->sdata->u.mesh.num_gates);
break;
}
return 0;
}
/**
* mesh_gate_num - number of gates known to this interface
* @sdata: subif data
*/
int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
{
return sdata->u.mesh.num_gates;
}
/**
* mesh_path_add - allocate and add a new path to the mesh path table
* @addr: destination address of the path (ETH_ALEN length)
* @sdata: local subif
*
* Returns: 0 on success
*
* State: the initial state of the new path is set to 0
*/
int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
struct mesh_table *tbl;
struct mesh_path *mpath, *new_mpath;
struct mpath_node *node, *new_node;
struct hlist_head *bucket;
struct hlist_node *n;
int grow = 0;
int err = 0;
u32 hash_idx;
if (compare_ether_addr(dst, sdata->vif.addr) == 0)
/* never add ourselves as neighbours */
return -ENOTSUPP;
if (is_multicast_ether_addr(dst))
return -ENOTSUPP;
if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
return -ENOSPC;
err = -ENOMEM;
new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC);
if (!new_mpath)
goto err_path_alloc;
new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
if (!new_node)
goto err_node_alloc;
read_lock_bh(&pathtbl_resize_lock);
memcpy(new_mpath->dst, dst, ETH_ALEN);
new_mpath->sdata = sdata;
new_mpath->flags = 0;
skb_queue_head_init(&new_mpath->frame_queue);
new_node->mpath = new_mpath;
new_mpath->timer.data = (unsigned long) new_mpath;
new_mpath->timer.function = mesh_path_timer;
new_mpath->exp_time = jiffies;
spin_lock_init(&new_mpath->state_lock);
init_timer(&new_mpath->timer);
tbl = resize_dereference_mesh_paths();
hash_idx = mesh_table_hash(dst, sdata, tbl);
bucket = &tbl->hash_buckets[hash_idx];
spin_lock(&tbl->hashwlock[hash_idx]);
err = -EEXIST;
hlist_for_each_entry(node, n, bucket, list) {
mpath = node->mpath;
if (mpath->sdata == sdata &&
compare_ether_addr(dst, mpath->dst) == 0)
goto err_exists;
}
hlist_add_head_rcu(&new_node->list, bucket);
if (atomic_inc_return(&tbl->entries) >=
tbl->mean_chain_len * (tbl->hash_mask + 1))
grow = 1;
mesh_paths_generation++;
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&pathtbl_resize_lock);
if (grow) {
set_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags);
ieee80211_queue_work(&local->hw, &sdata->work);
}
return 0;
err_exists:
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&pathtbl_resize_lock);
kfree(new_node);
err_node_alloc:
kfree(new_mpath);
err_path_alloc:
atomic_dec(&sdata->u.mesh.mpaths);
return err;
}
static void mesh_table_free_rcu(struct rcu_head *rcu)
{
struct mesh_table *tbl = container_of(rcu, struct mesh_table, rcu_head);
mesh_table_free(tbl, false);
}
void mesh_mpath_table_grow(void)
{
struct mesh_table *oldtbl, *newtbl;
write_lock_bh(&pathtbl_resize_lock);
oldtbl = resize_dereference_mesh_paths();
newtbl = mesh_table_alloc(oldtbl->size_order + 1);
if (!newtbl)
goto out;
if (mesh_table_grow(oldtbl, newtbl) < 0) {
__mesh_table_free(newtbl);
goto out;
}
rcu_assign_pointer(mesh_paths, newtbl);
call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
out:
write_unlock_bh(&pathtbl_resize_lock);
}
void mesh_mpp_table_grow(void)
{
struct mesh_table *oldtbl, *newtbl;
write_lock_bh(&pathtbl_resize_lock);
oldtbl = resize_dereference_mpp_paths();
newtbl = mesh_table_alloc(oldtbl->size_order + 1);
if (!newtbl)
goto out;
if (mesh_table_grow(oldtbl, newtbl) < 0) {
__mesh_table_free(newtbl);
goto out;
}
rcu_assign_pointer(mpp_paths, newtbl);
call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
out:
write_unlock_bh(&pathtbl_resize_lock);
}
int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
struct mesh_table *tbl;
struct mesh_path *mpath, *new_mpath;
struct mpath_node *node, *new_node;
struct hlist_head *bucket;
struct hlist_node *n;
int grow = 0;
int err = 0;
u32 hash_idx;
if (compare_ether_addr(dst, sdata->vif.addr) == 0)
/* never add ourselves as neighbours */
return -ENOTSUPP;
if (is_multicast_ether_addr(dst))
return -ENOTSUPP;
err = -ENOMEM;
new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC);
if (!new_mpath)
goto err_path_alloc;
new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
if (!new_node)
goto err_node_alloc;
read_lock_bh(&pathtbl_resize_lock);
memcpy(new_mpath->dst, dst, ETH_ALEN);
memcpy(new_mpath->mpp, mpp, ETH_ALEN);
new_mpath->sdata = sdata;
new_mpath->flags = 0;
skb_queue_head_init(&new_mpath->frame_queue);
new_node->mpath = new_mpath;
init_timer(&new_mpath->timer);
new_mpath->exp_time = jiffies;
spin_lock_init(&new_mpath->state_lock);
tbl = resize_dereference_mpp_paths();
hash_idx = mesh_table_hash(dst, sdata, tbl);
bucket = &tbl->hash_buckets[hash_idx];
spin_lock(&tbl->hashwlock[hash_idx]);
err = -EEXIST;
hlist_for_each_entry(node, n, bucket, list) {
mpath = node->mpath;
if (mpath->sdata == sdata &&
compare_ether_addr(dst, mpath->dst) == 0)
goto err_exists;
}
hlist_add_head_rcu(&new_node->list, bucket);
if (atomic_inc_return(&tbl->entries) >=
tbl->mean_chain_len * (tbl->hash_mask + 1))
grow = 1;
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&pathtbl_resize_lock);
if (grow) {
set_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags);
ieee80211_queue_work(&local->hw, &sdata->work);
}
return 0;
err_exists:
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&pathtbl_resize_lock);
kfree(new_node);
err_node_alloc:
kfree(new_mpath);
err_path_alloc:
return err;
}
/**
* mesh_plink_broken - deactivates paths and sends perr when a link breaks
*
* @sta: broken peer link
*
* This function must be called from the rate control algorithm if enough
* delivery errors suggest that a peer link is no longer usable.
*/
void mesh_plink_broken(struct sta_info *sta)
{
struct mesh_table *tbl;
static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
struct mesh_path *mpath;
struct mpath_node *node;
struct hlist_node *p;
struct ieee80211_sub_if_data *sdata = sta->sdata;
int i;
__le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_DEST_UNREACHABLE);
rcu_read_lock();
tbl = rcu_dereference(mesh_paths);
for_each_mesh_entry(tbl, p, node, i) {
mpath = node->mpath;
if (rcu_dereference(mpath->next_hop) == sta &&
mpath->flags & MESH_PATH_ACTIVE &&
!(mpath->flags & MESH_PATH_FIXED)) {
spin_lock_bh(&mpath->state_lock);
mpath->flags &= ~MESH_PATH_ACTIVE;
++mpath->sn;
spin_unlock_bh(&mpath->state_lock);
mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl,
mpath->dst, cpu_to_le32(mpath->sn),
reason, bcast, sdata);
}
}
rcu_read_unlock();
}
static void mesh_path_node_reclaim(struct rcu_head *rp)
{
struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
del_timer_sync(&node->mpath->timer);
atomic_dec(&sdata->u.mesh.mpaths);
kfree(node->mpath);
kfree(node);
}
/* needs to be called with the corresponding hashwlock taken */
static void __mesh_path_del(struct mesh_table *tbl, struct mpath_node *node)
{
struct mesh_path *mpath;
mpath = node->mpath;
spin_lock(&mpath->state_lock);
mpath->flags |= MESH_PATH_RESOLVING;
if (mpath->is_gate)
mesh_gate_del(tbl, mpath);
hlist_del_rcu(&node->list);
call_rcu(&node->rcu, mesh_path_node_reclaim);
spin_unlock(&mpath->state_lock);
atomic_dec(&tbl->entries);
}
/**
* mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
*
* @sta - mesh peer to match
*
* RCU notes: this function is called when a mesh plink transitions from
* PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
* allows path creation. This will happen before the sta can be freed (because
* sta_info_destroy() calls this) so any reader in a rcu read block will be
* protected against the plink disappearing.
*/
void mesh_path_flush_by_nexthop(struct sta_info *sta)
{
struct mesh_table *tbl;
struct mesh_path *mpath;
struct mpath_node *node;
struct hlist_node *p;
int i;
rcu_read_lock();
read_lock_bh(&pathtbl_resize_lock);
tbl = resize_dereference_mesh_paths();
for_each_mesh_entry(tbl, p, node, i) {
mpath = node->mpath;
if (rcu_dereference(mpath->next_hop) == sta) {
spin_lock(&tbl->hashwlock[i]);
__mesh_path_del(tbl, node);
spin_unlock(&tbl->hashwlock[i]);
}
}
read_unlock_bh(&pathtbl_resize_lock);
rcu_read_unlock();
}
static void table_flush_by_iface(struct mesh_table *tbl,
struct ieee80211_sub_if_data *sdata)
{
struct mesh_path *mpath;
struct mpath_node *node;
struct hlist_node *p;
int i;
WARN_ON(!rcu_read_lock_held());
for_each_mesh_entry(tbl, p, node, i) {
mpath = node->mpath;
if (mpath->sdata != sdata)
continue;
spin_lock_bh(&tbl->hashwlock[i]);
__mesh_path_del(tbl, node);
spin_unlock_bh(&tbl->hashwlock[i]);
}
}
/**
* mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
*
* This function deletes both mesh paths as well as mesh portal paths.
*
* @sdata - interface data to match
*
*/
void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
{
struct mesh_table *tbl;
rcu_read_lock();
read_lock_bh(&pathtbl_resize_lock);
tbl = resize_dereference_mesh_paths();
table_flush_by_iface(tbl, sdata);
tbl = resize_dereference_mpp_paths();
table_flush_by_iface(tbl, sdata);
read_unlock_bh(&pathtbl_resize_lock);
rcu_read_unlock();
}
/**
* mesh_path_del - delete a mesh path from the table
*
* @addr: dst address (ETH_ALEN length)
* @sdata: local subif
*
* Returns: 0 if successful
*/
int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata)
{
struct mesh_table *tbl;
struct mesh_path *mpath;
struct mpath_node *node;
struct hlist_head *bucket;
struct hlist_node *n;
int hash_idx;
int err = 0;
read_lock_bh(&pathtbl_resize_lock);
tbl = resize_dereference_mesh_paths();
hash_idx = mesh_table_hash(addr, sdata, tbl);
bucket = &tbl->hash_buckets[hash_idx];
spin_lock(&tbl->hashwlock[hash_idx]);
hlist_for_each_entry(node, n, bucket, list) {
mpath = node->mpath;
if (mpath->sdata == sdata &&
compare_ether_addr(addr, mpath->dst) == 0) {
__mesh_path_del(tbl, node);
goto enddel;
}
}
err = -ENXIO;
enddel:
mesh_paths_generation++;
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&pathtbl_resize_lock);
return err;
}
/**
* mesh_path_tx_pending - sends pending frames in a mesh path queue
*
* @mpath: mesh path to activate
*
* Locking: the state_lock of the mpath structure must NOT be held when calling
* this function.
*/
void mesh_path_tx_pending(struct mesh_path *mpath)
{
if (mpath->flags & MESH_PATH_ACTIVE)
ieee80211_add_pending_skbs(mpath->sdata->local,
&mpath->frame_queue);
}
/**
* mesh_path_send_to_gates - sends pending frames to all known mesh gates
*
* @mpath: mesh path whose queue will be emptied
*
* If there is only one gate, the frames are transferred from the failed mpath
* queue to that gate's queue. If there are more than one gates, the frames
* are copied from each gate to the next. After frames are copied, the
* mpath queues are emptied onto the transmission queue.
*/
int mesh_path_send_to_gates(struct mesh_path *mpath)
{
struct ieee80211_sub_if_data *sdata = mpath->sdata;
struct hlist_node *n;
struct mesh_table *tbl;
struct mesh_path *from_mpath = mpath;
struct mpath_node *gate = NULL;
bool copy = false;
struct hlist_head *known_gates;
rcu_read_lock();
tbl = rcu_dereference(mesh_paths);
known_gates = tbl->known_gates;
rcu_read_unlock();
if (!known_gates)
return -EHOSTUNREACH;
hlist_for_each_entry_rcu(gate, n, known_gates, list) {
if (gate->mpath->sdata != sdata)
continue;
if (gate->mpath->flags & MESH_PATH_ACTIVE) {
mpath_dbg("Forwarding to %pM\n", gate->mpath->dst);
mesh_path_move_to_queue(gate->mpath, from_mpath, copy);
from_mpath = gate->mpath;
copy = true;
} else {
mpath_dbg("Not forwarding %p\n", gate->mpath);
mpath_dbg("flags %x\n", gate->mpath->flags);
}
}
hlist_for_each_entry_rcu(gate, n, known_gates, list)
if (gate->mpath->sdata == sdata) {
mpath_dbg("Sending to %pM\n", gate->mpath->dst);
mesh_path_tx_pending(gate->mpath);
}
return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
}
/**
* mesh_path_discard_frame - discard a frame whose path could not be resolved
*
* @skb: frame to discard
* @sdata: network subif the frame was to be sent through
*
* Locking: the function must me called within a rcu_read_lock region
*/
void mesh_path_discard_frame(struct sk_buff *skb,
struct ieee80211_sub_if_data *sdata)
{
kfree_skb(skb);
sdata->u.mesh.mshstats.dropped_frames_no_route++;
}
/**
* mesh_path_flush_pending - free the pending queue of a mesh path
*
* @mpath: mesh path whose queue has to be freed
*
* Locking: the function must me called within a rcu_read_lock region
*/
void mesh_path_flush_pending(struct mesh_path *mpath)
{
struct sk_buff *skb;
while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
mesh_path_discard_frame(skb, mpath->sdata);
}
/**
* mesh_path_fix_nexthop - force a specific next hop for a mesh path
*
* @mpath: the mesh path to modify
* @next_hop: the next hop to force
*
* Locking: this function must be called holding mpath->state_lock
*/
void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
{
spin_lock_bh(&mpath->state_lock);
mesh_path_assign_nexthop(mpath, next_hop);
mpath->sn = 0xffff;
mpath->metric = 0;
mpath->hop_count = 0;
mpath->exp_time = 0;
mpath->flags |= MESH_PATH_FIXED;
mesh_path_activate(mpath);
spin_unlock_bh(&mpath->state_lock);
mesh_path_tx_pending(mpath);
}
static void mesh_path_node_free(struct hlist_node *p, bool free_leafs)
{
struct mesh_path *mpath;
struct mpath_node *node = hlist_entry(p, struct mpath_node, list);
mpath = node->mpath;
hlist_del_rcu(p);
if (free_leafs) {
del_timer_sync(&mpath->timer);
kfree(mpath);
}
kfree(node);
}
static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
{
struct mesh_path *mpath;
struct mpath_node *node, *new_node;
u32 hash_idx;
new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
if (new_node == NULL)
return -ENOMEM;
node = hlist_entry(p, struct mpath_node, list);
mpath = node->mpath;
new_node->mpath = mpath;
hash_idx = mesh_table_hash(mpath->dst, mpath->sdata, newtbl);
hlist_add_head(&new_node->list,
&newtbl->hash_buckets[hash_idx]);
return 0;
}
int mesh_pathtbl_init(void)
{
struct mesh_table *tbl_path, *tbl_mpp;
int ret;
tbl_path = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
if (!tbl_path)
return -ENOMEM;
tbl_path->free_node = &mesh_path_node_free;
tbl_path->copy_node = &mesh_path_node_copy;
tbl_path->mean_chain_len = MEAN_CHAIN_LEN;
tbl_path->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
if (!tbl_path->known_gates) {
ret = -ENOMEM;
goto free_path;
}
INIT_HLIST_HEAD(tbl_path->known_gates);
tbl_mpp = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
if (!tbl_mpp) {
ret = -ENOMEM;
goto free_path;
}
tbl_mpp->free_node = &mesh_path_node_free;
tbl_mpp->copy_node = &mesh_path_node_copy;
tbl_mpp->mean_chain_len = MEAN_CHAIN_LEN;
tbl_mpp->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
if (!tbl_mpp->known_gates) {
ret = -ENOMEM;
goto free_mpp;
}
INIT_HLIST_HEAD(tbl_mpp->known_gates);
/* Need no locking since this is during init */
RCU_INIT_POINTER(mesh_paths, tbl_path);
RCU_INIT_POINTER(mpp_paths, tbl_mpp);
return 0;
free_mpp:
mesh_table_free(tbl_mpp, true);
free_path:
mesh_table_free(tbl_path, true);
return ret;
}
void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
{
struct mesh_table *tbl;
struct mesh_path *mpath;
struct mpath_node *node;
struct hlist_node *p;
int i;
rcu_read_lock();
tbl = rcu_dereference(mesh_paths);
for_each_mesh_entry(tbl, p, node, i) {
if (node->mpath->sdata != sdata)
continue;
mpath = node->mpath;
if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
(!(mpath->flags & MESH_PATH_FIXED)) &&
time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
mesh_path_del(mpath->dst, mpath->sdata);
}
rcu_read_unlock();
}
void mesh_pathtbl_unregister(void)
{
/* no need for locking during exit path */
mesh_table_free(rcu_dereference_protected(mesh_paths, 1), true);
mesh_table_free(rcu_dereference_protected(mpp_paths, 1), true);
}