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mac80211: don't initiate path discovery when forwarding frame with unknown DA

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We used to initiate a path discovery when receiving a frame for which
there is no forwarding information. To cut down on PREQ spam, just send
a (gated) PERR in response.

Also separate path discovery logic from nexthop querying. This patch
means we no longer queue frames when forwarding, so kill the PERR TX
stuff in discard_frame().

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Thomas Pedersen
2011-11-24 17:15:25 -08:00
committed by John W. Linville
parent dca7e9430c
commit 0cfda8519c
5 changed files with 79 additions and 77 deletions
Download Patch File Download Diff File Expand all files Collapse all files

111
net/mac80211/mesh_hwmp.c
View File

@@ -982,72 +982,97 @@ enddiscovery:
kfree(preq_node);
}
/**
* mesh_nexthop_lookup - put the appropriate next hop on a mesh frame
/* mesh_nexthop_resolve - lookup next hop for given skb and start path
* discovery if no forwarding information is found.
*
* @skb: 802.11 frame to be sent
* @sdata: network subif the frame will be sent through
*
* Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is
* found, the function will start a path discovery and queue the frame so it is
* sent when the path is resolved. This means the caller must not free the skb
* in this case.
* Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
* skb is freeed here if no mpath could be allocated.
*/
int mesh_nexthop_lookup(struct sk_buff *skb,
struct ieee80211_sub_if_data *sdata)
int mesh_nexthop_resolve(struct sk_buff *skb,
struct ieee80211_sub_if_data *sdata)
{
struct sk_buff *skb_to_free = NULL;
struct mesh_path *mpath;
struct sta_info *next_hop;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct mesh_path *mpath;
struct sk_buff *skb_to_free = NULL;
u8 *target_addr = hdr->addr3;
int err = 0;
rcu_read_lock();
mpath = mesh_path_lookup(target_addr, sdata);
err = mesh_nexthop_lookup(skb, sdata);
if (!err)
goto endlookup;
/* no nexthop found, start resolving */
mpath = mesh_path_lookup(target_addr, sdata);
if (!mpath) {
mesh_path_add(target_addr, sdata);
mpath = mesh_path_lookup(target_addr, sdata);
if (!mpath) {
sdata->u.mesh.mshstats.dropped_frames_no_route++;
mesh_path_discard_frame(skb, sdata);
err = -ENOSPC;
goto endlookup;
}
}
if (mpath->flags & MESH_PATH_ACTIVE) {
if (time_after(jiffies,
mpath->exp_time -
msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
!memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) &&
!(mpath->flags & MESH_PATH_RESOLVING) &&
!(mpath->flags & MESH_PATH_FIXED)) {
mesh_queue_preq(mpath,
PREQ_Q_F_START | PREQ_Q_F_REFRESH);
}
next_hop = rcu_dereference(mpath->next_hop);
if (next_hop) {
memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
} else
err = -ENOENT;
} else {
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
if (!(mpath->flags & MESH_PATH_RESOLVING)) {
/* Start discovery only if it is not running yet */
mesh_queue_preq(mpath, PREQ_Q_F_START);
}
if (!(mpath->flags & MESH_PATH_RESOLVING))
mesh_queue_preq(mpath, PREQ_Q_F_START);
if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
skb_to_free = skb_dequeue(&mpath->frame_queue);
if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN)
skb_to_free = skb_dequeue(&mpath->frame_queue);
info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
ieee80211_set_qos_hdr(sdata, skb);
skb_queue_tail(&mpath->frame_queue, skb);
if (skb_to_free)
mesh_path_discard_frame(skb_to_free, sdata);
err = -ENOENT;
info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
ieee80211_set_qos_hdr(sdata, skb);
skb_queue_tail(&mpath->frame_queue, skb);
err = -ENOENT;
if (skb_to_free)
mesh_path_discard_frame(skb_to_free, sdata);
endlookup:
rcu_read_unlock();
return err;
}
/**
* mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling
* this function is considered "using" the associated mpath, so preempt a path
* refresh if this mpath expires soon.
*
* @skb: 802.11 frame to be sent
* @sdata: network subif the frame will be sent through
*
* Returns: 0 if the next hop was found. Nonzero otherwise.
*/
int mesh_nexthop_lookup(struct sk_buff *skb,
struct ieee80211_sub_if_data *sdata)
{
struct mesh_path *mpath;
struct sta_info *next_hop;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
u8 *target_addr = hdr->addr3;
int err = -ENOENT;
rcu_read_lock();
mpath = mesh_path_lookup(target_addr, sdata);
if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
goto endlookup;
if (time_after(jiffies,
mpath->exp_time -
msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
!memcmp(sdata->vif.addr, hdr->addr4, ETH_ALEN) &&
!(mpath->flags & MESH_PATH_RESOLVING) &&
!(mpath->flags & MESH_PATH_FIXED))
mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
next_hop = rcu_dereference(mpath->next_hop);
if (next_hop) {
memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN);
memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
err = 0;
}
endlookup: