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batman-adv: protect bonding with rcu locks

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bonding / alternating candidates need to be secured by rcu locks
as well. This patch therefore converts the bonding list
from a plain pointer list to a rcu securable lists and references
the bonding candidates.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
This commit is contained in:
Simon Wunderlich 2011-01-19 20:01:43 +00:00 committed by Marek Lindner
parent 2ae2daf6c3
commit a4c135c561
7 changed files with 195 additions and 163 deletions
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2
net/batman-adv/hard-interface.c
View file

@ -271,7 +271,7 @@ static void hardif_activate_interface(struct batman_if *batman_if)
static void hardif_deactivate_interface(struct batman_if *batman_if)
{
if ((batman_if->if_status != IF_ACTIVE) &&
(batman_if->if_status != IF_TO_BE_ACTIVATED))
(batman_if->if_status != IF_TO_BE_ACTIVATED))
return;
batman_if->if_status = IF_INACTIVE;

25
net/batman-adv/originator.c
View file

@ -75,6 +75,14 @@ static void neigh_node_free_rcu(struct rcu_head *rcu)
kref_put(&neigh_node->refcount, neigh_node_free_ref);
}
void neigh_node_free_rcu_bond(struct rcu_head *rcu)
{
struct neigh_node *neigh_node;
neigh_node = container_of(rcu, struct neigh_node, rcu_bond);
kref_put(&neigh_node->refcount, neigh_node_free_ref);
}
struct neigh_node *create_neighbor(struct orig_node *orig_node,
struct orig_node *orig_neigh_node,
uint8_t *neigh,
@ -91,6 +99,7 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
return NULL;
INIT_HLIST_NODE(&neigh_node->list);
INIT_LIST_HEAD(&neigh_node->bonding_list);
memcpy(neigh_node->addr, neigh, ETH_ALEN);
neigh_node->orig_node = orig_neigh_node;
@ -106,13 +115,20 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
void orig_node_free_ref(struct kref *refcount)
{
struct hlist_node *node, *node_tmp;
struct neigh_node *neigh_node;
struct neigh_node *neigh_node, *tmp_neigh_node;
struct orig_node *orig_node;
orig_node = container_of(refcount, struct orig_node, refcount);
spin_lock_bh(&orig_node->neigh_list_lock);
/* for all bonding members ... */
list_for_each_entry_safe(neigh_node, tmp_neigh_node,
&orig_node->bond_list, bonding_list) {
list_del_rcu(&neigh_node->bonding_list);
call_rcu(&neigh_node->rcu_bond, neigh_node_free_rcu_bond);
}
/* for all neighbors towards this originator ... */
hlist_for_each_entry_safe(neigh_node, node, node_tmp,
&orig_node->neigh_list, list) {
@ -207,6 +223,7 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
return NULL;
INIT_HLIST_HEAD(&orig_node->neigh_list);
INIT_LIST_HEAD(&orig_node->bond_list);
spin_lock_init(&orig_node->ogm_cnt_lock);
spin_lock_init(&orig_node->neigh_list_lock);
kref_init(&orig_node->refcount);
@ -220,6 +237,8 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
orig_node->batman_seqno_reset = jiffies - 1
- msecs_to_jiffies(RESET_PROTECTION_MS);
atomic_set(&orig_node->bond_candidates, 0);
size = bat_priv->num_ifaces * sizeof(unsigned long) * NUM_WORDS;
orig_node->bcast_own = kzalloc(size, GFP_ATOMIC);
@ -295,6 +314,7 @@ static bool purge_orig_neighbors(struct bat_priv *bat_priv,
neigh_purged = true;
hlist_del_rcu(&neigh_node->list);
bonding_candidate_del(orig_node, neigh_node);
call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
} else {
if ((!*best_neigh_node) ||
@ -326,9 +346,6 @@ static bool purge_orig_node(struct bat_priv *bat_priv,
best_neigh_node,
orig_node->hna_buff,
orig_node->hna_buff_len);
/* update bonding candidates, we could have lost
* some candidates. */
update_bonding_candidates(orig_node);
}
}

1
net/batman-adv/originator.h
View file

@ -26,6 +26,7 @@ int originator_init(struct bat_priv *bat_priv);
void originator_free(struct bat_priv *bat_priv);
void purge_orig_ref(struct bat_priv *bat_priv);
void orig_node_free_ref(struct kref *refcount);
void neigh_node_free_rcu_bond(struct rcu_head *rcu);
struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr);
struct neigh_node *create_neighbor(struct orig_node *orig_node,
struct orig_node *orig_neigh_node,

313
net/batman-adv/routing.c
View file

@ -271,6 +271,101 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
return ret;
}
/* caller must hold the neigh_list_lock */
void bonding_candidate_del(struct orig_node *orig_node,
struct neigh_node *neigh_node)
{
/* this neighbor is not part of our candidate list */
if (list_empty(&neigh_node->bonding_list))
goto out;
list_del_rcu(&neigh_node->bonding_list);
call_rcu(&neigh_node->rcu_bond, neigh_node_free_rcu_bond);
INIT_LIST_HEAD(&neigh_node->bonding_list);
atomic_dec(&orig_node->bond_candidates);
out:
return;
}
static void bonding_candidate_add(struct orig_node *orig_node,
struct neigh_node *neigh_node)
{
struct hlist_node *node;
struct neigh_node *tmp_neigh_node;
uint8_t best_tq, interference_candidate = 0;
spin_lock_bh(&orig_node->neigh_list_lock);
/* only consider if it has the same primary address ... */
if (!compare_orig(orig_node->orig,
neigh_node->orig_node->primary_addr))
goto candidate_del;
if (!orig_node->router)
goto candidate_del;
best_tq = orig_node->router->tq_avg;
/* ... and is good enough to be considered */
if (neigh_node->tq_avg < best_tq - BONDING_TQ_THRESHOLD)
goto candidate_del;
/**
* check if we have another candidate with the same mac address or
* interface. If we do, we won't select this candidate because of
* possible interference.
*/
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_node->neigh_list, list) {
if (tmp_neigh_node == neigh_node)
continue;
/* we only care if the other candidate is even
* considered as candidate. */
if (list_empty(&tmp_neigh_node->bonding_list))
continue;
if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
(compare_orig(neigh_node->addr, tmp_neigh_node->addr))) {
interference_candidate = 1;
break;
}
}
/* don't care further if it is an interference candidate */
if (interference_candidate)
goto candidate_del;
/* this neighbor already is part of our candidate list */
if (!list_empty(&neigh_node->bonding_list))
goto out;
list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
kref_get(&neigh_node->refcount);
atomic_inc(&orig_node->bond_candidates);
goto out;
candidate_del:
bonding_candidate_del(orig_node, neigh_node);
out:
spin_unlock_bh(&orig_node->neigh_list_lock);
return;
}
/* copy primary address for bonding */
static void bonding_save_primary(struct orig_node *orig_node,
struct orig_node *orig_neigh_node,
struct batman_packet *batman_packet)
{
if (!(batman_packet->flags & PRIMARIES_FIRST_HOP))
return;
memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
}
static void update_orig(struct bat_priv *bat_priv,
struct orig_node *orig_node,
struct ethhdr *ethhdr,
@ -339,6 +434,8 @@ static void update_orig(struct bat_priv *bat_priv,
neigh_node->last_ttl = batman_packet->ttl;
}
bonding_candidate_add(orig_node, neigh_node);
tmp_hna_buff_len = (hna_buff_len > batman_packet->num_hna * ETH_ALEN ?
batman_packet->num_hna * ETH_ALEN : hna_buff_len);
@ -497,123 +594,10 @@ static char count_real_packets(struct ethhdr *ethhdr,
return -1;
}
/* copy primary address for bonding */
static void mark_bonding_address(struct orig_node *orig_node,
struct orig_node *orig_neigh_node,
struct batman_packet *batman_packet)
{
if (batman_packet->flags & PRIMARIES_FIRST_HOP)
memcpy(orig_neigh_node->primary_addr,
orig_node->orig, ETH_ALEN);
return;
}
/* mark possible bond.candidates in the neighbor list */
void update_bonding_candidates(struct orig_node *orig_node)
{
int candidates;
int interference_candidate;
int best_tq;
struct hlist_node *node, *node2;
struct neigh_node *tmp_neigh_node, *tmp_neigh_node2;
struct neigh_node *first_candidate, *last_candidate;
/* update the candidates for this originator */
if (!orig_node->router) {
orig_node->bond.candidates = 0;
return;
}
best_tq = orig_node->router->tq_avg;
/* update bond.candidates */
candidates = 0;
/* mark other nodes which also received "PRIMARIES FIRST HOP" packets
* as "bonding partner" */
/* first, zero the list */
rcu_read_lock();
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_node->neigh_list, list) {
tmp_neigh_node->next_bond_candidate = NULL;
}
rcu_read_unlock();
first_candidate = NULL;
last_candidate = NULL;
rcu_read_lock();
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_node->neigh_list, list) {
/* only consider if it has the same primary address ... */
if (memcmp(orig_node->orig,
tmp_neigh_node->orig_node->primary_addr,
ETH_ALEN) != 0)
continue;
/* ... and is good enough to be considered */
if (tmp_neigh_node->tq_avg < best_tq - BONDING_TQ_THRESHOLD)
continue;
/* check if we have another candidate with the same
* mac address or interface. If we do, we won't
* select this candidate because of possible interference. */
interference_candidate = 0;
hlist_for_each_entry_rcu(tmp_neigh_node2, node2,
&orig_node->neigh_list, list) {
if (tmp_neigh_node2 == tmp_neigh_node)
continue;
/* we only care if the other candidate is even
* considered as candidate. */
if (!tmp_neigh_node2->next_bond_candidate)
continue;
if ((tmp_neigh_node->if_incoming ==
tmp_neigh_node2->if_incoming)
|| (memcmp(tmp_neigh_node->addr,
tmp_neigh_node2->addr, ETH_ALEN) == 0)) {
interference_candidate = 1;
break;
}
}
/* don't care further if it is an interference candidate */
if (interference_candidate)
continue;
if (!first_candidate) {
first_candidate = tmp_neigh_node;
tmp_neigh_node->next_bond_candidate = first_candidate;
} else
tmp_neigh_node->next_bond_candidate = last_candidate;
last_candidate = tmp_neigh_node;
candidates++;
}
rcu_read_unlock();
if (candidates > 0) {
first_candidate->next_bond_candidate = last_candidate;
orig_node->bond.selected = first_candidate;
}
orig_node->bond.candidates = candidates;
}
void receive_bat_packet(struct ethhdr *ethhdr,
struct batman_packet *batman_packet,
unsigned char *hna_buff, int hna_buff_len,
struct batman_if *if_incoming)
struct batman_packet *batman_packet,
unsigned char *hna_buff, int hna_buff_len,
struct batman_if *if_incoming)
{
struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
struct batman_if *batman_if;
@ -795,6 +779,8 @@ void receive_bat_packet(struct ethhdr *ethhdr,
is_bidirectional = is_bidirectional_neigh(orig_node, orig_neigh_node,
batman_packet, if_incoming);
bonding_save_primary(orig_node, orig_neigh_node, batman_packet);
/* update ranking if it is not a duplicate or has the same
* seqno and similar ttl as the non-duplicate */
if (is_bidirectional &&
@ -804,9 +790,6 @@ void receive_bat_packet(struct ethhdr *ethhdr,
update_orig(bat_priv, orig_node, ethhdr, batman_packet,
if_incoming, hna_buff, hna_buff_len, is_duplicate);
mark_bonding_address(orig_node, orig_neigh_node, batman_packet);
update_bonding_candidates(orig_node);
/* is single hop (direct) neighbor */
if (is_single_hop_neigh) {
@ -1095,14 +1078,15 @@ int recv_icmp_packet(struct sk_buff *skb, struct batman_if *recv_if)
}
/* find a suitable router for this originator, and use
* bonding if possible. */
* bonding if possible. increases the found neighbors
* refcount.*/
struct neigh_node *find_router(struct bat_priv *bat_priv,
struct orig_node *orig_node,
struct batman_if *recv_if)
{
struct orig_node *primary_orig_node;
struct orig_node *router_orig;
struct neigh_node *router, *first_candidate, *best_router;
struct neigh_node *router, *first_candidate, *tmp_neigh_node;
static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
int bonding_enabled;
@ -1114,18 +1098,25 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
/* without bonding, the first node should
* always choose the default router. */
bonding_enabled = atomic_read(&bat_priv->bonding);
if ((!recv_if) && (!bonding_enabled))
return orig_node->router;
rcu_read_lock();
/* select default router to output */
router = orig_node->router;
router_orig = orig_node->router->orig_node;
if (!router_orig) {
rcu_read_unlock();
return NULL;
}
if ((!recv_if) && (!bonding_enabled))
goto return_router;
/* if we have something in the primary_addr, we can search
* for a potential bonding candidate. */
if (memcmp(router_orig->primary_addr, zero_mac, ETH_ALEN) == 0)
return orig_node->router;
goto return_router;
/* find the orig_node which has the primary interface. might
* even be the same as our router_orig in many cases */
@ -1134,60 +1125,81 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
router_orig->orig, ETH_ALEN) == 0) {
primary_orig_node = router_orig;
} else {
rcu_read_lock();
primary_orig_node = hash_find(bat_priv->orig_hash, compare_orig,
choose_orig,
router_orig->primary_addr);
rcu_read_unlock();
if (!primary_orig_node)
return orig_node->router;
goto return_router;
}
/* with less than 2 candidates, we can't do any
* bonding and prefer the original router. */
if (primary_orig_node->bond.candidates < 2)
return orig_node->router;
if (atomic_read(&primary_orig_node->bond_candidates) < 2)
goto return_router;
/* all nodes between should choose a candidate which
* is is not on the interface where the packet came
* in. */
first_candidate = primary_orig_node->bond.selected;
router = first_candidate;
first_candidate = NULL;
router = NULL;
if (bonding_enabled) {
/* in the bonding case, send the packets in a round
* robin fashion over the remaining interfaces. */
do {
list_for_each_entry_rcu(tmp_neigh_node,
&primary_orig_node->bond_list, bonding_list) {
if (!first_candidate)
first_candidate = tmp_neigh_node;
/* recv_if == NULL on the first node. */
if (router->if_incoming != recv_if)
if (tmp_neigh_node->if_incoming != recv_if) {
router = tmp_neigh_node;
break;
}
}
router = router->next_bond_candidate;
} while (router != first_candidate);
/* use the first candidate if nothing was found. */
if (!router)
router = first_candidate;
primary_orig_node->bond.selected = router->next_bond_candidate;
/* selected should point to the next element
* after the current router */
spin_lock_bh(&primary_orig_node->neigh_list_lock);
/* this is a list_move(), which unfortunately
* does not exist as rcu version */
list_del_rcu(&primary_orig_node->bond_list);
list_add_rcu(&primary_orig_node->bond_list,
&router->bonding_list);
spin_unlock_bh(&primary_orig_node->neigh_list_lock);
} else {
/* if bonding is disabled, use the best of the
* remaining candidates which are not using
* this interface. */
best_router = first_candidate;
list_for_each_entry_rcu(tmp_neigh_node,
&primary_orig_node->bond_list, bonding_list) {
if (!first_candidate)
first_candidate = tmp_neigh_node;
do {
/* recv_if == NULL on the first node. */
if ((router->if_incoming != recv_if) &&
(router->tq_avg > best_router->tq_avg))
best_router = router;
if (tmp_neigh_node->if_incoming != recv_if)
/* if we don't have a router yet
* or this one is better, choose it. */
if ((!router) ||
(tmp_neigh_node->tq_avg > router->tq_avg)) {
router = tmp_neigh_node;
}
}
router = router->next_bond_candidate;
} while (router != first_candidate);
router = best_router;
/* use the first candidate if nothing was found. */
if (!router)
router = first_candidate;
}
return_router:
kref_get(&router->refcount);
rcu_read_unlock();
return router;
}
@ -1247,6 +1259,7 @@ int route_unicast_packet(struct sk_buff *skb, struct batman_if *recv_if,
unicast_packet->dest));
rcu_read_unlock();
/* find_router() increases neigh_nodes refcount if found. */
router = find_router(bat_priv, orig_node, recv_if);
if (!router) {

6
net/batman-adv/routing.h
View file

@ -39,7 +39,9 @@ int recv_bcast_packet(struct sk_buff *skb, struct batman_if *recv_if);
int recv_vis_packet(struct sk_buff *skb, struct batman_if *recv_if);
int recv_bat_packet(struct sk_buff *skb, struct batman_if *recv_if);
struct neigh_node *find_router(struct bat_priv *bat_priv,
struct orig_node *orig_node, struct batman_if *recv_if);
void update_bonding_candidates(struct orig_node *orig_node);
struct orig_node *orig_node,
struct batman_if *recv_if);
void bonding_candidate_del(struct orig_node *orig_node,
struct neigh_node *neigh_node);
#endif /* _NET_BATMAN_ADV_ROUTING_H_ */

9
net/batman-adv/types.h
View file

@ -90,10 +90,8 @@ struct orig_node {
struct bat_priv *bat_priv;
unsigned long last_frag_packet;
spinlock_t ogm_cnt_lock; /* protects ogm counter */
struct {
uint8_t candidates;
struct neigh_node *selected;
} bond;
atomic_t bond_candidates;
struct list_head bond_list;
};
struct gw_node {
@ -116,11 +114,12 @@ struct neigh_node {
uint8_t tq_index;
uint8_t tq_avg;
uint8_t last_ttl;
struct neigh_node *next_bond_candidate;
struct list_head bonding_list;
unsigned long last_valid;
unsigned long real_bits[NUM_WORDS];
struct kref refcount;
struct rcu_head rcu;
struct rcu_head rcu_bond;
struct orig_node *orig_node;
struct batman_if *if_incoming;
};

2
net/batman-adv/unicast.c
View file

@ -299,6 +299,7 @@ int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)
if (!orig_node)
orig_node = transtable_search(bat_priv, ethhdr->h_dest);
/* find_router() increases neigh_nodes refcount if found. */
router = find_router(bat_priv, orig_node, NULL);
if (!router)
@ -306,7 +307,6 @@ int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)
/* don't lock while sending the packets ... we therefore
* copy the required data before sending */
batman_if = router->if_incoming;
memcpy(dstaddr, router->addr, ETH_ALEN);