batman-adv: Make orig_node->router an rcu protected pointer
authorLinus Lüssing <linus.luessing@web.de>
Mon, 14 Mar 2011 22:43:37 +0000 (22:43 +0000)
committerSven Eckelmann <sven@narfation.org>
Sun, 17 Apr 2011 19:11:01 +0000 (21:11 +0200)
The rcu protected macros rcu_dereference() and rcu_assign_pointer()
for the orig_node->router need to be used, as well as spin/rcu locking.
Otherwise we might end up using a router pointer pointing to already
freed memory.

Therefore this commit introduces the safe getter method
orig_node_get_router().

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
net/batman-adv/gateway_client.c
net/batman-adv/icmp_socket.c
net/batman-adv/originator.c
net/batman-adv/originator.h
net/batman-adv/routing.c
net/batman-adv/send.c
net/batman-adv/types.h
net/batman-adv/vis.c

index 879ac15..42a8a7b 100644 (file)
@@ -98,6 +98,7 @@ void gw_election(struct bat_priv *bat_priv)
 {
        struct hlist_node *node;
        struct gw_node *gw_node, *curr_gw, *curr_gw_tmp = NULL;
+       struct neigh_node *router;
        uint8_t max_tq = 0;
        uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
        int down, up;
@@ -133,10 +134,11 @@ void gw_election(struct bat_priv *bat_priv)
        }
 
        hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
-               if (!gw_node->orig_node->router)
+               if (gw_node->deleted)
                        continue;
 
-               if (gw_node->deleted)
+               router = orig_node_get_router(gw_node->orig_node);
+               if (!router)
                        continue;
 
                switch (atomic_read(&bat_priv->gw_sel_class)) {
@@ -144,15 +146,14 @@ void gw_election(struct bat_priv *bat_priv)
                        gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
                                             &down, &up);
 
-                       tmp_gw_factor = (gw_node->orig_node->router->tq_avg *
-                                        gw_node->orig_node->router->tq_avg *
+                       tmp_gw_factor = (router->tq_avg * router->tq_avg *
                                         down * 100 * 100) /
                                         (TQ_LOCAL_WINDOW_SIZE *
                                         TQ_LOCAL_WINDOW_SIZE * 64);
 
                        if ((tmp_gw_factor > max_gw_factor) ||
                            ((tmp_gw_factor == max_gw_factor) &&
-                            (gw_node->orig_node->router->tq_avg > max_tq)))
+                            (router->tq_avg > max_tq)))
                                curr_gw_tmp = gw_node;
                        break;
 
@@ -164,19 +165,25 @@ void gw_election(struct bat_priv *bat_priv)
                          *     soon as a better gateway appears which has
                          *     $routing_class more tq points)
                          **/
-                       if (gw_node->orig_node->router->tq_avg > max_tq)
+                       if (router->tq_avg > max_tq)
                                curr_gw_tmp = gw_node;
                        break;
                }
 
-               if (gw_node->orig_node->router->tq_avg > max_tq)
-                       max_tq = gw_node->orig_node->router->tq_avg;
+               if (router->tq_avg > max_tq)
+                       max_tq = router->tq_avg;
 
                if (tmp_gw_factor > max_gw_factor)
                        max_gw_factor = tmp_gw_factor;
+
+               neigh_node_free_ref(router);
        }
 
        if (curr_gw != curr_gw_tmp) {
+               router = orig_node_get_router(curr_gw_tmp->orig_node);
+               if (!router)
+                       goto out;
+
                if ((curr_gw) && (!curr_gw_tmp))
                        bat_dbg(DBG_BATMAN, bat_priv,
                                "Removing selected gateway - "
@@ -187,45 +194,47 @@ void gw_election(struct bat_priv *bat_priv)
                                "(gw_flags: %i, tq: %i)\n",
                                curr_gw_tmp->orig_node->orig,
                                curr_gw_tmp->orig_node->gw_flags,
-                               curr_gw_tmp->orig_node->router->tq_avg);
+                               router->tq_avg);
                else
                        bat_dbg(DBG_BATMAN, bat_priv,
                                "Changing route to gateway %pM "
                                "(gw_flags: %i, tq: %i)\n",
                                curr_gw_tmp->orig_node->orig,
                                curr_gw_tmp->orig_node->gw_flags,
-                               curr_gw_tmp->orig_node->router->tq_avg);
+                               router->tq_avg);
 
+               neigh_node_free_ref(router);
                gw_select(bat_priv, curr_gw_tmp);
        }
 
+out:
        rcu_read_unlock();
 }
 
 void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
 {
        struct orig_node *curr_gw_orig;
+       struct neigh_node *router_gw = NULL, *router_orig = NULL;
        uint8_t gw_tq_avg, orig_tq_avg;
 
        curr_gw_orig = gw_get_selected(bat_priv);
        if (!curr_gw_orig)
                goto deselect;
 
-       rcu_read_lock();
-       if (!curr_gw_orig->router)
-               goto deselect_rcu;
+       router_gw = orig_node_get_router(curr_gw_orig);
+       if (!router_gw)
+               goto deselect;
 
        /* this node already is the gateway */
        if (curr_gw_orig == orig_node)
-               goto out_rcu;
-
-       if (!orig_node->router)
-               goto out_rcu;
+               goto out;
 
-       gw_tq_avg = curr_gw_orig->router->tq_avg;
-       rcu_read_unlock();
+       router_orig = orig_node_get_router(orig_node);
+       if (!router_orig)
+               goto out;
 
-       orig_tq_avg = orig_node->router->tq_avg;
+       gw_tq_avg = router_gw->tq_avg;
+       orig_tq_avg = router_orig->tq_avg;
 
        /* the TQ value has to be better */
        if (orig_tq_avg < gw_tq_avg)
@@ -243,18 +252,16 @@ void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
                "Restarting gateway selection: better gateway found (tq curr: "
                "%i, tq new: %i)\n",
                gw_tq_avg, orig_tq_avg);
-       goto deselect;
 
-out_rcu:
-       rcu_read_unlock();
-       goto out;
-deselect_rcu:
-       rcu_read_unlock();
 deselect:
        gw_deselect(bat_priv);
 out:
        if (curr_gw_orig)
                orig_node_free_ref(curr_gw_orig);
+       if (router_gw)
+               neigh_node_free_ref(router_gw);
+       if (router_orig)
+               neigh_node_free_ref(router_orig);
 
        return;
 }
@@ -362,23 +369,30 @@ void gw_node_purge(struct bat_priv *bat_priv)
        spin_unlock_bh(&bat_priv->gw_list_lock);
 }
 
+/**
+ * fails if orig_node has no router
+ */
 static int _write_buffer_text(struct bat_priv *bat_priv,
                              struct seq_file *seq, struct gw_node *gw_node)
 {
        struct gw_node *curr_gw;
-       int down, up, ret;
+       struct neigh_node *router;
+       int down, up, ret = -1;
 
        gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
 
+       router = orig_node_get_router(gw_node->orig_node);
+       if (!router)
+               goto out;
+
        rcu_read_lock();
        curr_gw = rcu_dereference(bat_priv->curr_gw);
 
        ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
                       (curr_gw == gw_node ? "=>" : "  "),
                       gw_node->orig_node->orig,
-                      gw_node->orig_node->router->tq_avg,
-                      gw_node->orig_node->router->addr,
-                      gw_node->orig_node->router->if_incoming->net_dev->name,
+                      router->tq_avg, router->addr,
+                      router->if_incoming->net_dev->name,
                       gw_node->orig_node->gw_flags,
                       (down > 2048 ? down / 1024 : down),
                       (down > 2048 ? "MBit" : "KBit"),
@@ -386,6 +400,8 @@ static int _write_buffer_text(struct bat_priv *bat_priv,
                       (up > 2048 ? "MBit" : "KBit"));
 
        rcu_read_unlock();
+       neigh_node_free_ref(router);
+out:
        return ret;
 }
 
@@ -423,10 +439,10 @@ int gw_client_seq_print_text(struct seq_file *seq, void *offset)
                if (gw_node->deleted)
                        continue;
 
-               if (!gw_node->orig_node->router)
+               /* fails if orig_node has no router */
+               if (_write_buffer_text(bat_priv, seq, gw_node) < 0)
                        continue;
 
-               _write_buffer_text(bat_priv, seq, gw_node);
                gw_count++;
        }
        rcu_read_unlock();
index 34ce56c..49079c2 100644 (file)
@@ -218,23 +218,13 @@ static ssize_t bat_socket_write(struct file *file, const char __user *buff,
        if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
                goto dst_unreach;
 
-       rcu_read_lock();
        orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
-
        if (!orig_node)
-               goto unlock;
-
-       neigh_node = orig_node->router;
+               goto dst_unreach;
 
+       neigh_node = orig_node_get_router(orig_node);
        if (!neigh_node)
-               goto unlock;
-
-       if (!atomic_inc_not_zero(&neigh_node->refcount)) {
-               neigh_node = NULL;
-               goto unlock;
-       }
-
-       rcu_read_unlock();
+               goto dst_unreach;
 
        if (!neigh_node->if_incoming)
                goto dst_unreach;
@@ -252,8 +242,6 @@ static ssize_t bat_socket_write(struct file *file, const char __user *buff,
        send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
        goto out;
 
-unlock:
-       rcu_read_unlock();
 dst_unreach:
        icmp_packet->msg_type = DESTINATION_UNREACHABLE;
        bat_socket_add_packet(socket_client, icmp_packet, packet_len);
index 0b91330..b4cfe36 100644 (file)
@@ -70,6 +70,21 @@ void neigh_node_free_ref(struct neigh_node *neigh_node)
                call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
 }
 
+/* increases the refcounter of a found router */
+struct neigh_node *orig_node_get_router(struct orig_node *orig_node)
+{
+       struct neigh_node *router;
+
+       rcu_read_lock();
+       router = rcu_dereference(orig_node->router);
+
+       if (router && !atomic_inc_not_zero(&router->refcount))
+               router = NULL;
+
+       rcu_read_unlock();
+       return router;
+}
+
 struct neigh_node *create_neighbor(struct orig_node *orig_node,
                                   struct orig_node *orig_neigh_node,
                                   uint8_t *neigh,
@@ -390,7 +405,7 @@ int orig_seq_print_text(struct seq_file *seq, void *offset)
        struct hlist_node *node, *node_tmp;
        struct hlist_head *head;
        struct orig_node *orig_node;
-       struct neigh_node *neigh_node;
+       struct neigh_node *neigh_node, *neigh_node_tmp;
        int batman_count = 0;
        int last_seen_secs;
        int last_seen_msecs;
@@ -421,37 +436,41 @@ int orig_seq_print_text(struct seq_file *seq, void *offset)
 
                rcu_read_lock();
                hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
-                       if (!orig_node->router)
+                       neigh_node = orig_node_get_router(orig_node);
+                       if (!neigh_node)
                                continue;
 
-                       if (orig_node->router->tq_avg == 0)
-                               continue;
+                       if (neigh_node->tq_avg == 0)
+                               goto next;
 
                        last_seen_secs = jiffies_to_msecs(jiffies -
                                                orig_node->last_valid) / 1000;
                        last_seen_msecs = jiffies_to_msecs(jiffies -
                                                orig_node->last_valid) % 1000;
 
-                       neigh_node = orig_node->router;
                        seq_printf(seq, "%pM %4i.%03is   (%3i) %pM [%10s]:",
                                   orig_node->orig, last_seen_secs,
                                   last_seen_msecs, neigh_node->tq_avg,
                                   neigh_node->addr,
                                   neigh_node->if_incoming->net_dev->name);
 
-                       hlist_for_each_entry_rcu(neigh_node, node_tmp,
+                       hlist_for_each_entry_rcu(neigh_node_tmp, node_tmp,
                                                 &orig_node->neigh_list, list) {
-                               seq_printf(seq, " %pM (%3i)", neigh_node->addr,
-                                               neigh_node->tq_avg);
+                               seq_printf(seq, " %pM (%3i)",
+                                          neigh_node_tmp->addr,
+                                          neigh_node_tmp->tq_avg);
                        }
 
                        seq_printf(seq, "\n");
                        batman_count++;
+
+next:
+                       neigh_node_free_ref(neigh_node);
                }
                rcu_read_unlock();
        }
 
-       if ((batman_count == 0))
+       if (batman_count == 0)
                seq_printf(seq, "No batman nodes in range ...\n");
 
        return 0;
index 5cc0110..e1d641f 100644 (file)
@@ -34,6 +34,7 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
                                   uint8_t *neigh,
                                   struct hard_iface *if_incoming);
 void neigh_node_free_ref(struct neigh_node *neigh_node);
+struct neigh_node *orig_node_get_router(struct orig_node *orig_node);
 int orig_seq_print_text(struct seq_file *seq, void *offset);
 int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num);
 int orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num);
index f212abe..b7d43ca 100644 (file)
@@ -87,18 +87,20 @@ static void update_route(struct bat_priv *bat_priv,
                         struct neigh_node *neigh_node,
                         unsigned char *hna_buff, int hna_buff_len)
 {
-       struct neigh_node *neigh_node_tmp;
+       struct neigh_node *curr_router;
+
+       curr_router = orig_node_get_router(orig_node);
 
        /* route deleted */
-       if ((orig_node->router) && (!neigh_node)) {
+       if ((curr_router) && (!neigh_node)) {
 
                bat_dbg(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n",
                        orig_node->orig);
                hna_global_del_orig(bat_priv, orig_node,
                                    "originator timed out");
 
-               /* route added */
-       } else if ((!orig_node->router) && (neigh_node)) {
+       /* route added */
+       } else if ((!curr_router) && (neigh_node)) {
 
                bat_dbg(DBG_ROUTES, bat_priv,
                        "Adding route towards: %pM (via %pM)\n",
@@ -106,21 +108,29 @@ static void update_route(struct bat_priv *bat_priv,
                hna_global_add_orig(bat_priv, orig_node,
                                    hna_buff, hna_buff_len);
 
-               /* route changed */
+       /* route changed */
        } else {
                bat_dbg(DBG_ROUTES, bat_priv,
                        "Changing route towards: %pM "
                        "(now via %pM - was via %pM)\n",
                        orig_node->orig, neigh_node->addr,
-                       orig_node->router->addr);
+                       curr_router->addr);
        }
 
+       if (curr_router)
+               neigh_node_free_ref(curr_router);
+
+       /* increase refcount of new best neighbor */
        if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
                neigh_node = NULL;
-       neigh_node_tmp = orig_node->router;
-       orig_node->router = neigh_node;
-       if (neigh_node_tmp)
-               neigh_node_free_ref(neigh_node_tmp);
+
+       spin_lock_bh(&orig_node->neigh_list_lock);
+       rcu_assign_pointer(orig_node->router, neigh_node);
+       spin_unlock_bh(&orig_node->neigh_list_lock);
+
+       /* decrease refcount of previous best neighbor */
+       if (curr_router)
+               neigh_node_free_ref(curr_router);
 }
 
 
@@ -128,16 +138,23 @@ void update_routes(struct bat_priv *bat_priv, struct orig_node *orig_node,
                   struct neigh_node *neigh_node, unsigned char *hna_buff,
                   int hna_buff_len)
 {
+       struct neigh_node *router = NULL;
 
        if (!orig_node)
-               return;
+               goto out;
+
+       router = orig_node_get_router(orig_node);
 
-       if (orig_node->router != neigh_node)
+       if (router != neigh_node)
                update_route(bat_priv, orig_node, neigh_node,
                             hna_buff, hna_buff_len);
        /* may be just HNA changed */
        else
                update_HNA(bat_priv, orig_node, hna_buff, hna_buff_len);
+
+out:
+       if (router)
+               neigh_node_free_ref(router);
 }
 
 static int is_bidirectional_neigh(struct orig_node *orig_node,
@@ -288,8 +305,8 @@ 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;
+       struct neigh_node *tmp_neigh_node, *router = NULL;
+       uint8_t interference_candidate = 0;
 
        spin_lock_bh(&orig_node->neigh_list_lock);
 
@@ -298,13 +315,12 @@ static void bonding_candidate_add(struct orig_node *orig_node,
                         neigh_node->orig_node->primary_addr))
                goto candidate_del;
 
-       if (!orig_node->router)
+       router = orig_node_get_router(orig_node);
+       if (!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)
+       if (neigh_node->tq_avg < router->tq_avg - BONDING_TQ_THRESHOLD)
                goto candidate_del;
 
        /**
@@ -350,7 +366,9 @@ candidate_del:
 
 out:
        spin_unlock_bh(&orig_node->neigh_list_lock);
-       return;
+
+       if (router)
+               neigh_node_free_ref(router);
 }
 
 /* copy primary address for bonding */
@@ -373,6 +391,7 @@ static void update_orig(struct bat_priv *bat_priv,
                        char is_duplicate)
 {
        struct neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
+       struct neigh_node *router = NULL;
        struct orig_node *orig_node_tmp;
        struct hlist_node *node;
        int tmp_hna_buff_len;
@@ -441,19 +460,18 @@ static void update_orig(struct bat_priv *bat_priv,
 
        /* if this neighbor already is our next hop there is nothing
         * to change */
-       if (orig_node->router == neigh_node)
+       router = orig_node_get_router(orig_node);
+       if (router == neigh_node)
                goto update_hna;
 
        /* if this neighbor does not offer a better TQ we won't consider it */
-       if ((orig_node->router) &&
-           (orig_node->router->tq_avg > neigh_node->tq_avg))
+       if (router && (router->tq_avg > neigh_node->tq_avg))
                goto update_hna;
 
        /* if the TQ is the same and the link not more symetric we
         * won't consider it either */
-       if ((orig_node->router) &&
-            (neigh_node->tq_avg == orig_node->router->tq_avg)) {
-               orig_node_tmp = orig_node->router->orig_node;
+       if (router && (neigh_node->tq_avg == router->tq_avg)) {
+               orig_node_tmp = router->orig_node;
                spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
                bcast_own_sum_orig =
                        orig_node_tmp->bcast_own_sum[if_incoming->if_num];
@@ -474,7 +492,7 @@ static void update_orig(struct bat_priv *bat_priv,
        goto update_gw;
 
 update_hna:
-       update_routes(bat_priv, orig_node, orig_node->router,
+       update_routes(bat_priv, orig_node, router,
                      hna_buff, tmp_hna_buff_len);
 
 update_gw:
@@ -496,6 +514,8 @@ unlock:
 out:
        if (neigh_node)
                neigh_node_free_ref(neigh_node);
+       if (router)
+               neigh_node_free_ref(router);
 }
 
 /* checks whether the host restarted and is in the protection time.
@@ -603,6 +623,8 @@ void receive_bat_packet(struct ethhdr *ethhdr,
        struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
        struct hard_iface *hard_iface;
        struct orig_node *orig_neigh_node, *orig_node;
+       struct neigh_node *router = NULL, *router_router = NULL;
+       struct neigh_node *orig_neigh_router = NULL;
        char has_directlink_flag;
        char is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0;
        char is_broadcast = 0, is_bidirectional, is_single_hop_neigh;
@@ -747,14 +769,15 @@ void receive_bat_packet(struct ethhdr *ethhdr,
                goto out;
        }
 
+       router = orig_node_get_router(orig_node);
+       if (router)
+               router_router = orig_node_get_router(router->orig_node);
+
        /* avoid temporary routing loops */
-       if ((orig_node->router) &&
-           (orig_node->router->orig_node->router) &&
-           (compare_eth(orig_node->router->addr,
-                        batman_packet->prev_sender)) &&
+       if (router && router_router &&
+           (compare_eth(router->addr, batman_packet->prev_sender)) &&
            !(compare_eth(batman_packet->orig, batman_packet->prev_sender)) &&
-           (compare_eth(orig_node->router->addr,
-                        orig_node->router->orig_node->router->addr))) {
+           (compare_eth(router->addr, router_router->addr))) {
                bat_dbg(DBG_BATMAN, bat_priv,
                        "Drop packet: ignoring all rebroadcast packets that "
                        "may make me loop (sender: %pM)\n", ethhdr->h_source);
@@ -769,9 +792,11 @@ void receive_bat_packet(struct ethhdr *ethhdr,
        if (!orig_neigh_node)
                goto out;
 
+       orig_neigh_router = orig_node_get_router(orig_neigh_node);
+
        /* drop packet if sender is not a direct neighbor and if we
         * don't route towards it */
-       if (!is_single_hop_neigh && (!orig_neigh_node->router)) {
+       if (!is_single_hop_neigh && (!orig_neigh_router)) {
                bat_dbg(DBG_BATMAN, bat_priv,
                        "Drop packet: OGM via unknown neighbor!\n");
                goto out_neigh;
@@ -825,6 +850,13 @@ out_neigh:
        if ((orig_neigh_node) && (!is_single_hop_neigh))
                orig_node_free_ref(orig_neigh_node);
 out:
+       if (router)
+               neigh_node_free_ref(router);
+       if (router_router)
+               neigh_node_free_ref(router_router);
+       if (orig_neigh_router)
+               neigh_node_free_ref(orig_neigh_router);
+
        orig_node_free_ref(orig_node);
 }
 
@@ -869,7 +901,7 @@ static int recv_my_icmp_packet(struct bat_priv *bat_priv,
                               struct sk_buff *skb, size_t icmp_len)
 {
        struct orig_node *orig_node = NULL;
-       struct neigh_node *neigh_node = NULL;
+       struct neigh_node *router = NULL;
        struct icmp_packet_rr *icmp_packet;
        int ret = NET_RX_DROP;
 
@@ -886,23 +918,13 @@ static int recv_my_icmp_packet(struct bat_priv *bat_priv,
 
        /* answer echo request (ping) */
        /* get routing information */
-       rcu_read_lock();
        orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
-
        if (!orig_node)
-               goto unlock;
-
-       neigh_node = orig_node->router;
-
-       if (!neigh_node)
-               goto unlock;
-
-       if (!atomic_inc_not_zero(&neigh_node->refcount)) {
-               neigh_node = NULL;
-               goto unlock;
-       }
+               goto out;
 
-       rcu_read_unlock();
+       router = orig_node_get_router(orig_node);
+       if (!router)
+               goto out;
 
        /* create a copy of the skb, if needed, to modify it. */
        if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
@@ -916,15 +938,12 @@ static int recv_my_icmp_packet(struct bat_priv *bat_priv,
        icmp_packet->msg_type = ECHO_REPLY;
        icmp_packet->ttl = TTL;
 
-       send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
+       send_skb_packet(skb, router->if_incoming, router->addr);
        ret = NET_RX_SUCCESS;
-       goto out;
 
-unlock:
-       rcu_read_unlock();
 out:
-       if (neigh_node)
-               neigh_node_free_ref(neigh_node);
+       if (router)
+               neigh_node_free_ref(router);
        if (orig_node)
                orig_node_free_ref(orig_node);
        return ret;
@@ -934,7 +953,7 @@ static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
                                  struct sk_buff *skb)
 {
        struct orig_node *orig_node = NULL;
-       struct neigh_node *neigh_node = NULL;
+       struct neigh_node *router = NULL;
        struct icmp_packet *icmp_packet;
        int ret = NET_RX_DROP;
 
@@ -952,23 +971,13 @@ static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
                goto out;
 
        /* get routing information */
-       rcu_read_lock();
        orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
-
        if (!orig_node)
-               goto unlock;
-
-       neigh_node = orig_node->router;
-
-       if (!neigh_node)
-               goto unlock;
-
-       if (!atomic_inc_not_zero(&neigh_node->refcount)) {
-               neigh_node = NULL;
-               goto unlock;
-       }
+               goto out;
 
-       rcu_read_unlock();
+       router = orig_node_get_router(orig_node);
+       if (!router)
+               goto out;
 
        /* create a copy of the skb, if needed, to modify it. */
        if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
@@ -982,15 +991,12 @@ static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
        icmp_packet->msg_type = TTL_EXCEEDED;
        icmp_packet->ttl = TTL;
 
-       send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
+       send_skb_packet(skb, router->if_incoming, router->addr);
        ret = NET_RX_SUCCESS;
-       goto out;
 
-unlock:
-       rcu_read_unlock();
 out:
-       if (neigh_node)
-               neigh_node_free_ref(neigh_node);
+       if (router)
+               neigh_node_free_ref(router);
        if (orig_node)
                orig_node_free_ref(orig_node);
        return ret;
@@ -1003,7 +1009,7 @@ int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
        struct icmp_packet_rr *icmp_packet;
        struct ethhdr *ethhdr;
        struct orig_node *orig_node = NULL;
-       struct neigh_node *neigh_node = NULL;
+       struct neigh_node *router = NULL;
        int hdr_size = sizeof(struct icmp_packet);
        int ret = NET_RX_DROP;
 
@@ -1050,23 +1056,13 @@ int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
                return recv_icmp_ttl_exceeded(bat_priv, skb);
 
        /* get routing information */
-       rcu_read_lock();
        orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
-
        if (!orig_node)
-               goto unlock;
-
-       neigh_node = orig_node->router;
-
-       if (!neigh_node)
-               goto unlock;
-
-       if (!atomic_inc_not_zero(&neigh_node->refcount)) {
-               neigh_node = NULL;
-               goto unlock;
-       }
+               goto out;
 
-       rcu_read_unlock();
+       router = orig_node_get_router(orig_node);
+       if (!router)
+               goto out;
 
        /* create a copy of the skb, if needed, to modify it. */
        if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
@@ -1078,15 +1074,12 @@ int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
        icmp_packet->ttl--;
 
        /* route it */
-       send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
+       send_skb_packet(skb, router->if_incoming, router->addr);
        ret = NET_RX_SUCCESS;
-       goto out;
 
-unlock:
-       rcu_read_unlock();
 out:
-       if (neigh_node)
-               neigh_node_free_ref(neigh_node);
+       if (router)
+               neigh_node_free_ref(router);
        if (orig_node)
                orig_node_free_ref(orig_node);
        return ret;
@@ -1208,7 +1201,8 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
        if (!orig_node)
                return NULL;
 
-       if (!orig_node->router)
+       router = orig_node_get_router(orig_node);
+       if (!router)
                return NULL;
 
        /* without bonding, the first node should
@@ -1217,9 +1211,8 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
 
        rcu_read_lock();
        /* select default router to output */
-       router = orig_node->router;
-       router_orig = orig_node->router->orig_node;
-       if (!router_orig || !atomic_inc_not_zero(&router->refcount)) {
+       router_orig = router->orig_node;
+       if (!router_orig) {
                rcu_read_unlock();
                return NULL;
        }
@@ -1251,7 +1244,6 @@ struct neigh_node *find_router(struct bat_priv *bat_priv,
        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. */
index d49e54d..e78670c 100644 (file)
@@ -308,6 +308,7 @@ void schedule_forward_packet(struct orig_node *orig_node,
                             struct hard_iface *if_incoming)
 {
        struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
+       struct neigh_node *router;
        unsigned char in_tq, in_ttl, tq_avg = 0;
        unsigned long send_time;
 
@@ -316,6 +317,8 @@ void schedule_forward_packet(struct orig_node *orig_node,
                return;
        }
 
+       router = orig_node_get_router(orig_node);
+
        in_tq = batman_packet->tq;
        in_ttl = batman_packet->ttl;
 
@@ -324,20 +327,22 @@ void schedule_forward_packet(struct orig_node *orig_node,
 
        /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
         * of our best tq value */
-       if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
+       if (router && router->tq_avg != 0) {
 
                /* rebroadcast ogm of best ranking neighbor as is */
-               if (!compare_eth(orig_node->router->addr, ethhdr->h_source)) {
-                       batman_packet->tq = orig_node->router->tq_avg;
+               if (!compare_eth(router->addr, ethhdr->h_source)) {
+                       batman_packet->tq = router->tq_avg;
 
-                       if (orig_node->router->last_ttl)
-                               batman_packet->ttl = orig_node->router->last_ttl
-                                                       - 1;
+                       if (router->last_ttl)
+                               batman_packet->ttl = router->last_ttl - 1;
                }
 
-               tq_avg = orig_node->router->tq_avg;
+               tq_avg = router->tq_avg;
        }
 
+       if (router)
+               neigh_node_free_ref(router);
+
        /* apply hop penalty */
        batman_packet->tq = hop_penalty(batman_packet->tq, bat_priv);
 
index 83445cf..1854cbb 100644 (file)
@@ -67,7 +67,7 @@ struct hard_iface {
 struct orig_node {
        uint8_t orig[ETH_ALEN];
        uint8_t primary_addr[ETH_ALEN];
-       struct neigh_node *router;
+       struct neigh_node __rcu *router; /* rcu protected pointer */
        unsigned long *bcast_own;
        uint8_t *bcast_own_sum;
        unsigned long last_valid;
@@ -83,7 +83,7 @@ struct orig_node {
        uint32_t last_bcast_seqno;
        struct hlist_head neigh_list;
        struct list_head frag_list;
-       spinlock_t neigh_list_lock; /* protects neighbor list */
+       spinlock_t neigh_list_lock; /* protects neigh_list and router */
        atomic_t refcount;
        struct rcu_head rcu;
        struct hlist_node hash_entry;
index f90212f..d4cc4f5 100644 (file)
@@ -558,6 +558,7 @@ static int find_best_vis_server(struct bat_priv *bat_priv,
                                struct vis_info *info)
 {
        struct hashtable_t *hash = bat_priv->orig_hash;
+       struct neigh_node *router;
        struct hlist_node *node;
        struct hlist_head *head;
        struct orig_node *orig_node;
@@ -571,13 +572,17 @@ static int find_best_vis_server(struct bat_priv *bat_priv,
 
                rcu_read_lock();
                hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
-                       if ((orig_node) && (orig_node->router) &&
-                           (orig_node->flags & VIS_SERVER) &&
-                           (orig_node->router->tq_avg > best_tq)) {
-                               best_tq = orig_node->router->tq_avg;
+                       router = orig_node_get_router(orig_node);
+                       if (!router)
+                               continue;
+
+                       if ((orig_node->flags & VIS_SERVER) &&
+                           (router->tq_avg > best_tq)) {
+                               best_tq = router->tq_avg;
                                memcpy(packet->target_orig, orig_node->orig,
                                       ETH_ALEN);
                        }
+                       neigh_node_free_ref(router);
                }
                rcu_read_unlock();
        }
@@ -605,7 +610,7 @@ static int generate_vis_packet(struct bat_priv *bat_priv)
        struct hlist_node *node;
        struct hlist_head *head;
        struct orig_node *orig_node;
-       struct neigh_node *neigh_node;
+       struct neigh_node *router;
        struct vis_info *info = (struct vis_info *)bat_priv->my_vis_info;
        struct vis_packet *packet = (struct vis_packet *)info->skb_packet->data;
        struct vis_info_entry *entry;
@@ -633,30 +638,32 @@ static int generate_vis_packet(struct bat_priv *bat_priv)
 
                rcu_read_lock();
                hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
-                       neigh_node = orig_node->router;
-
-                       if (!neigh_node)
+                       router = orig_node_get_router(orig_node);
+                       if (!router)
                                continue;
 
-                       if (!compare_eth(neigh_node->addr, orig_node->orig))
-                               continue;
+                       if (!compare_eth(router->addr, orig_node->orig))
+                               goto next;
 
-                       if (neigh_node->if_incoming->if_status != IF_ACTIVE)
-                               continue;
+                       if (router->if_incoming->if_status != IF_ACTIVE)
+                               goto next;
 
-                       if (neigh_node->tq_avg < 1)
-                               continue;
+                       if (router->tq_avg < 1)
+                               goto next;
 
                        /* fill one entry into buffer. */
                        entry = (struct vis_info_entry *)
                                      skb_put(info->skb_packet, sizeof(*entry));
                        memcpy(entry->src,
-                              neigh_node->if_incoming->net_dev->dev_addr,
+                              router->if_incoming->net_dev->dev_addr,
                               ETH_ALEN);
                        memcpy(entry->dest, orig_node->orig, ETH_ALEN);
-                       entry->quality = neigh_node->tq_avg;
+                       entry->quality = router->tq_avg;
                        packet->entries++;
 
+next:
+                       neigh_node_free_ref(router);
+
                        if (vis_packet_full(info))
                                goto unlock;
                }
@@ -725,6 +732,7 @@ static void purge_vis_packets(struct bat_priv *bat_priv)
 static void broadcast_vis_packet(struct bat_priv *bat_priv,
                                 struct vis_info *info)
 {
+       struct neigh_node *router;
        struct hashtable_t *hash = bat_priv->orig_hash;
        struct hlist_node *node;
        struct hlist_head *head;
@@ -745,19 +753,26 @@ static void broadcast_vis_packet(struct bat_priv *bat_priv,
                rcu_read_lock();
                hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
                        /* if it's a vis server and reachable, send it. */
-                       if ((!orig_node) || (!orig_node->router))
-                               continue;
                        if (!(orig_node->flags & VIS_SERVER))
                                continue;
+
+                       router = orig_node_get_router(orig_node);
+                       if (!router)
+                               continue;
+
                        /* don't send it if we already received the packet from
-                       * this node. */
+                        * this node. */
                        if (recv_list_is_in(bat_priv, &info->recv_list,
-                                           orig_node->orig))
+                                           orig_node->orig)) {
+                               neigh_node_free_ref(router);
                                continue;
+                       }
 
                        memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
-                       hard_iface = orig_node->router->if_incoming;
-                       memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
+                       hard_iface = router->if_incoming;
+                       memcpy(dstaddr, router->addr, ETH_ALEN);
+
+                       neigh_node_free_ref(router);
 
                        skb = skb_clone(info->skb_packet, GFP_ATOMIC);
                        if (skb)
@@ -772,45 +787,29 @@ static void unicast_vis_packet(struct bat_priv *bat_priv,
                               struct vis_info *info)
 {
        struct orig_node *orig_node;
-       struct neigh_node *neigh_node = NULL;
+       struct neigh_node *router = NULL;
        struct sk_buff *skb;
        struct vis_packet *packet;
 
        packet = (struct vis_packet *)info->skb_packet->data;
 
-       rcu_read_lock();
        orig_node = orig_hash_find(bat_priv, packet->target_orig);
-
        if (!orig_node)
-               goto unlock;
+               goto out;
 
-       neigh_node = orig_node->router;
-
-       if (!neigh_node)
-               goto unlock;
-
-       if (!atomic_inc_not_zero(&neigh_node->refcount)) {
-               neigh_node = NULL;
-               goto unlock;
-       }
-
-       rcu_read_unlock();
+       router = orig_node_get_router(orig_node);
+       if (!router)
+               goto out;
 
        skb = skb_clone(info->skb_packet, GFP_ATOMIC);
        if (skb)
-               send_skb_packet(skb, neigh_node->if_incoming,
-                               neigh_node->addr);
-
-       goto out;
+               send_skb_packet(skb, router->if_incoming, router->addr);
 
-unlock:
-       rcu_read_unlock();
 out:
-       if (neigh_node)
-               neigh_node_free_ref(neigh_node);
+       if (router)
+               neigh_node_free_ref(router);
        if (orig_node)
                orig_node_free_ref(orig_node);
-       return;
 }
 
 /* only send one vis packet. called from send_vis_packets() */