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-rw-r--r--net/mac80211/mesh_pathtbl.c790
1 files changed, 790 insertions, 0 deletions
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
new file mode 100644
index 000000000..69d5e1ec6
--- /dev/null
+++ b/net/mac80211/mesh_pathtbl.c
@@ -0,0 +1,790 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2008, 2009 open80211s Ltd.
+ * Author: Luis Carlos Cobo <luisca@cozybit.com>
+ */
+
+#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"
+
+static void mesh_path_free_rcu(struct mesh_table *tbl, struct mesh_path *mpath);
+
+static u32 mesh_table_hash(const void *addr, u32 len, u32 seed)
+{
+ /* Use last four bytes of hw addr as hash index */
+ return jhash_1word(__get_unaligned_cpu32((u8 *)addr + 2), seed);
+}
+
+static const struct rhashtable_params mesh_rht_params = {
+ .nelem_hint = 2,
+ .automatic_shrinking = true,
+ .key_len = ETH_ALEN,
+ .key_offset = offsetof(struct mesh_path, dst),
+ .head_offset = offsetof(struct mesh_path, rhash),
+ .hashfn = mesh_table_hash,
+};
+
+static inline bool mpath_expired(struct mesh_path *mpath)
+{
+ return (mpath->flags & MESH_PATH_ACTIVE) &&
+ time_after(jiffies, mpath->exp_time) &&
+ !(mpath->flags & MESH_PATH_FIXED);
+}
+
+static void mesh_path_rht_free(void *ptr, void *tblptr)
+{
+ struct mesh_path *mpath = ptr;
+ struct mesh_table *tbl = tblptr;
+
+ mesh_path_free_rcu(tbl, mpath);
+}
+
+static void mesh_table_init(struct mesh_table *tbl)
+{
+ INIT_HLIST_HEAD(&tbl->known_gates);
+ INIT_HLIST_HEAD(&tbl->walk_head);
+ atomic_set(&tbl->entries, 0);
+ spin_lock_init(&tbl->gates_lock);
+ spin_lock_init(&tbl->walk_lock);
+
+ /* rhashtable_init() may fail only in case of wrong
+ * mesh_rht_params
+ */
+ WARN_ON(rhashtable_init(&tbl->rhead, &mesh_rht_params));
+}
+
+static void mesh_table_free(struct mesh_table *tbl)
+{
+ rhashtable_free_and_destroy(&tbl->rhead,
+ mesh_path_rht_free, tbl);
+}
+
+/**
+ * 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;
+ unsigned long flags;
+
+ rcu_assign_pointer(mpath->next_hop, sta);
+
+ spin_lock_irqsave(&mpath->frame_queue.lock, flags);
+ skb_queue_walk(&mpath->frame_queue, skb) {
+ hdr = (struct ieee80211_hdr *) skb->data;
+ memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
+ memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN);
+ ieee80211_mps_set_frame_flags(sta->sdata, sta, hdr);
+ }
+
+ 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 addresses */
+ 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.
+ *
+ * @gate_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, *fskb, *tmp;
+ struct sk_buff_head failq;
+ unsigned long flags;
+
+ if (WARN_ON(gate_mpath == from_mpath))
+ return;
+ if (WARN_ON(!gate_mpath->next_hop))
+ return;
+
+ __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);
+
+ skb_queue_walk_safe(&failq, fskb, tmp) {
+ if (skb_queue_len(&gate_mpath->frame_queue) >=
+ MESH_FRAME_QUEUE_LEN) {
+ mpath_dbg(gate_mpath->sdata, "mpath queue full!\n");
+ break;
+ }
+
+ skb = skb_copy(fskb, GFP_ATOMIC);
+ if (WARN_ON(!skb))
+ break;
+
+ prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
+ skb_queue_tail(&gate_mpath->frame_queue, skb);
+
+ if (copy)
+ continue;
+
+ __skb_unlink(fskb, &failq);
+ kfree_skb(fskb);
+ }
+
+ mpath_dbg(gate_mpath->sdata, "Mpath queue for gate %pM has %d frames\n",
+ gate_mpath->dst, skb_queue_len(&gate_mpath->frame_queue));
+
+ 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, const u8 *dst,
+ struct ieee80211_sub_if_data *sdata)
+{
+ struct mesh_path *mpath;
+
+ mpath = rhashtable_lookup(&tbl->rhead, dst, mesh_rht_params);
+
+ if (mpath && mpath_expired(mpath)) {
+ spin_lock_bh(&mpath->state_lock);
+ mpath->flags &= ~MESH_PATH_ACTIVE;
+ spin_unlock_bh(&mpath->state_lock);
+ }
+ return mpath;
+}
+
+/**
+ * mesh_path_lookup - look up a path in the mesh path table
+ * @sdata: local subif
+ * @dst: hardware address (ETH_ALEN length) of destination
+ *
+ * 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(struct ieee80211_sub_if_data *sdata, const u8 *dst)
+{
+ return mpath_lookup(&sdata->u.mesh.mesh_paths, dst, sdata);
+}
+
+struct mesh_path *
+mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
+{
+ return mpath_lookup(&sdata->u.mesh.mpp_paths, dst, sdata);
+}
+
+static struct mesh_path *
+__mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
+{
+ int i = 0;
+ struct mesh_path *mpath;
+
+ hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) {
+ if (i++ == idx)
+ break;
+ }
+
+ if (!mpath)
+ return NULL;
+
+ if (mpath_expired(mpath)) {
+ spin_lock_bh(&mpath->state_lock);
+ mpath->flags &= ~MESH_PATH_ACTIVE;
+ spin_unlock_bh(&mpath->state_lock);
+ }
+ return mpath;
+}
+
+/**
+ * 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(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ return __mesh_path_lookup_by_idx(&sdata->u.mesh.mesh_paths, idx);
+}
+
+/**
+ * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
+ * @idx: index
+ * @sdata: local subif, or NULL for all entries
+ *
+ * Returns: pointer to the proxy path structure, or NULL if not found.
+ *
+ * Locking: must be called within a read rcu section.
+ */
+struct mesh_path *
+mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ return __mesh_path_lookup_by_idx(&sdata->u.mesh.mpp_paths, idx);
+}
+
+/**
+ * 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;
+ int err;
+
+ rcu_read_lock();
+ tbl = &mpath->sdata->u.mesh.mesh_paths;
+
+ spin_lock_bh(&mpath->state_lock);
+ if (mpath->is_gate) {
+ err = -EEXIST;
+ spin_unlock_bh(&mpath->state_lock);
+ goto err_rcu;
+ }
+ mpath->is_gate = true;
+ mpath->sdata->u.mesh.num_gates++;
+
+ spin_lock(&tbl->gates_lock);
+ hlist_add_head_rcu(&mpath->gate_list, &tbl->known_gates);
+ spin_unlock(&tbl->gates_lock);
+
+ spin_unlock_bh(&mpath->state_lock);
+
+ mpath_dbg(mpath->sdata,
+ "Mesh path: Recorded new gate: %pM. %d known gates\n",
+ mpath->dst, mpath->sdata->u.mesh.num_gates);
+ err = 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
+ */
+static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
+{
+ lockdep_assert_held(&mpath->state_lock);
+ if (!mpath->is_gate)
+ return;
+
+ mpath->is_gate = false;
+ spin_lock_bh(&tbl->gates_lock);
+ hlist_del_rcu(&mpath->gate_list);
+ mpath->sdata->u.mesh.num_gates--;
+ spin_unlock_bh(&tbl->gates_lock);
+
+ mpath_dbg(mpath->sdata,
+ "Mesh path: Deleted gate: %pM. %d known gates\n",
+ mpath->dst, mpath->sdata->u.mesh.num_gates);
+}
+
+/**
+ * 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;
+}
+
+static
+struct mesh_path *mesh_path_new(struct ieee80211_sub_if_data *sdata,
+ const u8 *dst, gfp_t gfp_flags)
+{
+ struct mesh_path *new_mpath;
+
+ new_mpath = kzalloc(sizeof(struct mesh_path), gfp_flags);
+ if (!new_mpath)
+ return NULL;
+
+ memcpy(new_mpath->dst, dst, ETH_ALEN);
+ eth_broadcast_addr(new_mpath->rann_snd_addr);
+ new_mpath->is_root = false;
+ new_mpath->sdata = sdata;
+ new_mpath->flags = 0;
+ skb_queue_head_init(&new_mpath->frame_queue);
+ new_mpath->exp_time = jiffies;
+ spin_lock_init(&new_mpath->state_lock);
+ timer_setup(&new_mpath->timer, mesh_path_timer, 0);
+
+ return new_mpath;
+}
+
+/**
+ * mesh_path_add - allocate and add a new path to the mesh path table
+ * @dst: 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
+ */
+struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata,
+ const u8 *dst)
+{
+ struct mesh_table *tbl;
+ struct mesh_path *mpath, *new_mpath;
+
+ if (ether_addr_equal(dst, sdata->vif.addr))
+ /* never add ourselves as neighbours */
+ return ERR_PTR(-ENOTSUPP);
+
+ if (is_multicast_ether_addr(dst))
+ return ERR_PTR(-ENOTSUPP);
+
+ if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
+ return ERR_PTR(-ENOSPC);
+
+ new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
+ if (!new_mpath)
+ return ERR_PTR(-ENOMEM);
+
+ tbl = &sdata->u.mesh.mesh_paths;
+ spin_lock_bh(&tbl->walk_lock);
+ mpath = rhashtable_lookup_get_insert_fast(&tbl->rhead,
+ &new_mpath->rhash,
+ mesh_rht_params);
+ if (!mpath)
+ hlist_add_head(&new_mpath->walk_list, &tbl->walk_head);
+ spin_unlock_bh(&tbl->walk_lock);
+
+ if (mpath) {
+ kfree(new_mpath);
+
+ if (IS_ERR(mpath))
+ return mpath;
+
+ new_mpath = mpath;
+ }
+
+ sdata->u.mesh.mesh_paths_generation++;
+ return new_mpath;
+}
+
+int mpp_path_add(struct ieee80211_sub_if_data *sdata,
+ const u8 *dst, const u8 *mpp)
+{
+ struct mesh_table *tbl;
+ struct mesh_path *new_mpath;
+ int ret;
+
+ if (ether_addr_equal(dst, sdata->vif.addr))
+ /* never add ourselves as neighbours */
+ return -ENOTSUPP;
+
+ if (is_multicast_ether_addr(dst))
+ return -ENOTSUPP;
+
+ new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
+
+ if (!new_mpath)
+ return -ENOMEM;
+
+ memcpy(new_mpath->mpp, mpp, ETH_ALEN);
+ tbl = &sdata->u.mesh.mpp_paths;
+
+ spin_lock_bh(&tbl->walk_lock);
+ ret = rhashtable_lookup_insert_fast(&tbl->rhead,
+ &new_mpath->rhash,
+ mesh_rht_params);
+ if (!ret)
+ hlist_add_head_rcu(&new_mpath->walk_list, &tbl->walk_head);
+ spin_unlock_bh(&tbl->walk_lock);
+
+ if (ret)
+ kfree(new_mpath);
+
+ sdata->u.mesh.mpp_paths_generation++;
+ return ret;
+}
+
+
+/**
+ * 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 ieee80211_sub_if_data *sdata = sta->sdata;
+ struct mesh_table *tbl = &sdata->u.mesh.mesh_paths;
+ static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+ struct mesh_path *mpath;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) {
+ if (rcu_access_pointer(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,
+ sdata->u.mesh.mshcfg.element_ttl,
+ mpath->dst, mpath->sn,
+ WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
+ }
+ }
+ rcu_read_unlock();
+}
+
+static void mesh_path_free_rcu(struct mesh_table *tbl,
+ struct mesh_path *mpath)
+{
+ struct ieee80211_sub_if_data *sdata = mpath->sdata;
+
+ spin_lock_bh(&mpath->state_lock);
+ mpath->flags |= MESH_PATH_RESOLVING | MESH_PATH_DELETED;
+ mesh_gate_del(tbl, mpath);
+ spin_unlock_bh(&mpath->state_lock);
+ del_timer_sync(&mpath->timer);
+ atomic_dec(&sdata->u.mesh.mpaths);
+ atomic_dec(&tbl->entries);
+ mesh_path_flush_pending(mpath);
+ kfree_rcu(mpath, rcu);
+}
+
+static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath)
+{
+ hlist_del_rcu(&mpath->walk_list);
+ rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
+ mesh_path_free_rcu(tbl, mpath);
+}
+
+/**
+ * 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 ieee80211_sub_if_data *sdata = sta->sdata;
+ struct mesh_table *tbl = &sdata->u.mesh.mesh_paths;
+ struct mesh_path *mpath;
+ struct hlist_node *n;
+
+ spin_lock_bh(&tbl->walk_lock);
+ hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
+ if (rcu_access_pointer(mpath->next_hop) == sta)
+ __mesh_path_del(tbl, mpath);
+ }
+ spin_unlock_bh(&tbl->walk_lock);
+}
+
+static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
+ const u8 *proxy)
+{
+ struct mesh_table *tbl = &sdata->u.mesh.mpp_paths;
+ struct mesh_path *mpath;
+ struct hlist_node *n;
+
+ spin_lock_bh(&tbl->walk_lock);
+ hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
+ if (ether_addr_equal(mpath->mpp, proxy))
+ __mesh_path_del(tbl, mpath);
+ }
+ spin_unlock_bh(&tbl->walk_lock);
+}
+
+static void table_flush_by_iface(struct mesh_table *tbl)
+{
+ struct mesh_path *mpath;
+ struct hlist_node *n;
+
+ spin_lock_bh(&tbl->walk_lock);
+ hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
+ __mesh_path_del(tbl, mpath);
+ }
+ spin_unlock_bh(&tbl->walk_lock);
+}
+
+/**
+ * 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)
+{
+ table_flush_by_iface(&sdata->u.mesh.mesh_paths);
+ table_flush_by_iface(&sdata->u.mesh.mpp_paths);
+}
+
+/**
+ * table_path_del - delete a path from the mesh or mpp table
+ *
+ * @tbl: mesh or mpp path table
+ * @sdata: local subif
+ * @addr: dst address (ETH_ALEN length)
+ *
+ * Returns: 0 if successful
+ */
+static int table_path_del(struct mesh_table *tbl,
+ struct ieee80211_sub_if_data *sdata,
+ const u8 *addr)
+{
+ struct mesh_path *mpath;
+
+ spin_lock_bh(&tbl->walk_lock);
+ mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
+ if (!mpath) {
+ spin_unlock_bh(&tbl->walk_lock);
+ return -ENXIO;
+ }
+
+ __mesh_path_del(tbl, mpath);
+ spin_unlock_bh(&tbl->walk_lock);
+ return 0;
+}
+
+
+/**
+ * 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(struct ieee80211_sub_if_data *sdata, const u8 *addr)
+{
+ int err;
+
+ /* flush relevant mpp entries first */
+ mpp_flush_by_proxy(sdata, addr);
+
+ err = table_path_del(&sdata->u.mesh.mesh_paths, sdata, addr);
+ sdata->u.mesh.mesh_paths_generation++;
+ 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 mesh_table *tbl;
+ struct mesh_path *from_mpath = mpath;
+ struct mesh_path *gate;
+ bool copy = false;
+
+ tbl = &sdata->u.mesh.mesh_paths;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
+ if (gate->flags & MESH_PATH_ACTIVE) {
+ mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst);
+ mesh_path_move_to_queue(gate, from_mpath, copy);
+ from_mpath = gate;
+ copy = true;
+ } else {
+ mpath_dbg(sdata,
+ "Not forwarding to %pM (flags %#x)\n",
+ gate->dst, gate->flags);
+ }
+ }
+
+ hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
+ mpath_dbg(sdata, "Sending to %pM\n", gate->dst);
+ mesh_path_tx_pending(gate);
+ }
+ rcu_read_unlock();
+
+ 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 ieee80211_sub_if_data *sdata,
+ struct sk_buff *skb)
+{
+ ieee80211_free_txskb(&sdata->local->hw, 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(mpath->sdata, skb);
+}
+
+/**
+ * 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_SN_VALID;
+ mesh_path_activate(mpath);
+ spin_unlock_bh(&mpath->state_lock);
+ ewma_mesh_fail_avg_init(&next_hop->mesh->fail_avg);
+ /* init it at a low value - 0 start is tricky */
+ ewma_mesh_fail_avg_add(&next_hop->mesh->fail_avg, 1);
+ mesh_path_tx_pending(mpath);
+}
+
+void mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
+{
+ mesh_table_init(&sdata->u.mesh.mesh_paths);
+ mesh_table_init(&sdata->u.mesh.mpp_paths);
+}
+
+static
+void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
+ struct mesh_table *tbl)
+{
+ struct mesh_path *mpath;
+ struct hlist_node *n;
+
+ spin_lock_bh(&tbl->walk_lock);
+ hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
+ if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
+ (!(mpath->flags & MESH_PATH_FIXED)) &&
+ time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
+ __mesh_path_del(tbl, mpath);
+ }
+ spin_unlock_bh(&tbl->walk_lock);
+}
+
+void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
+{
+ mesh_path_tbl_expire(sdata, &sdata->u.mesh.mesh_paths);
+ mesh_path_tbl_expire(sdata, &sdata->u.mesh.mpp_paths);
+}
+
+void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata)
+{
+ mesh_table_free(&sdata->u.mesh.mesh_paths);
+ mesh_table_free(&sdata->u.mesh.mpp_paths);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 20:04:27 +0000