/**
* mesh_queue_preq - queue a PREQ to a given destination
*
* @mpath: mesh path to discover
* @flags: special attributes of the PREQ to be sent
*
* Locking: the function must be called from within a rcu read lock block.
*
*/
static void mesh_queue_preq(struct mesh_path *mpath, u8 flags)
{
struct ieee80211_sub_if_data *sdata = mpath->sdata;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_preq_queue *preq_node;
preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC);
if (!preq_node) {
mhwmp_dbg(sdata, "could not allocate PREQ node\n");
return;
}
spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
kfree(preq_node);
if (printk_ratelimit())
mhwmp_dbg(sdata, "PREQ node queue full\n");
return;
}
spin_lock(&mpath->state_lock);
if (mpath->flags & MESH_PATH_REQ_QUEUED) {
spin_unlock(&mpath->state_lock);
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
kfree(preq_node);
return;
}
memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
preq_node->flags = flags;
mpath->flags |= MESH_PATH_REQ_QUEUED;
spin_unlock(&mpath->state_lock);
list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
++ifmsh->preq_queue_len;
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
else if (time_before(jiffies, ifmsh->last_preq)) {
/* avoid long wait if did not send preqs for a long time
* and jiffies wrapped around
*/
ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1;
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
} else
mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
min_preq_int_jiff(sdata));
}
void mesh_path_timer(unsigned long data)
{
struct mesh_path *mpath = (void *) data;
struct ieee80211_sub_if_data *sdata = mpath->sdata;
int ret;
if (sdata->local->quiescing)
return;
spin_lock_bh(&mpath->state_lock);
if (mpath->flags & MESH_PATH_RESOLVED ||
(!(mpath->flags & MESH_PATH_RESOLVING))) {
mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
spin_unlock_bh(&mpath->state_lock);
} else if (mpath->discovery_retries < max_preq_retries(sdata)) {
++mpath->discovery_retries;
mpath->discovery_timeout *= 2;
mpath->flags &= ~MESH_PATH_REQ_QUEUED;
spin_unlock_bh(&mpath->state_lock);
mesh_queue_preq(mpath, 0);
} else {
mpath->flags = 0;
mpath->exp_time = jiffies;
spin_unlock_bh(&mpath->state_lock);
if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
ret = mesh_path_send_to_gates(mpath);
if (ret)
mhwmp_dbg(sdata, "no gate was reachable\n");
} else
mesh_path_flush_pending(mpath);
}
}
void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
u8 flags, target_flags = 0;
flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol)
? RANN_FLAG_IS_GATE : 0;
switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) {
case IEEE80211_PROACTIVE_RANN:
mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr,
++ifmsh->sn, 0, NULL, 0, broadcast_addr,
0, ifmsh->mshcfg.element_ttl,
interval, 0, 0, sdata);
break;
case IEEE80211_PROACTIVE_PREQ_WITH_PREP:
flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG;
case IEEE80211_PROACTIVE_PREQ_NO_PREP:
interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout;
target_flags |= IEEE80211_PREQ_TO_FLAG |
IEEE80211_PREQ_USN_FLAG;
mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr,
++ifmsh->sn, target_flags,
(u8 *) broadcast_addr, 0, broadcast_addr,
0, ifmsh->mshcfg.element_ttl, interval,
0, ifmsh->preq_id++, sdata);
break;
default:
mhwmp_dbg(sdata, "Proactive mechanism not supported\n");
return;
}
}
static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
struct ieee80211_rann_ie *rann)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 ttl, flags, hopcount;
u8 *orig_addr;
u32 orig_sn, metric;
ttl = rann->rann_ttl;
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
ttl--;
flags = rann->rann_flags;
orig_addr = rann->rann_addr;
orig_sn = rann->rann_seq;
hopcount = rann->rann_hopcount;
hopcount++;
metric = rann->rann_metric;
mhwmp_dbg("received RANN from %pM\n", orig_addr);
rcu_read_lock();
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
mesh_path_add(orig_addr, sdata);
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
return;
}
mesh_queue_preq(mpath,
PREQ_Q_F_START | PREQ_Q_F_REFRESH);
}
if (mpath->sn < orig_sn) {
mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
cpu_to_le32(orig_sn),
0, NULL, 0, broadcast_addr,
hopcount, ttl, 0,
cpu_to_le32(metric + mpath->metric),
0, sdata);
mpath->sn = orig_sn;
}
rcu_read_unlock();
}
static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
struct ieee80211_rann_ie *rann)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
struct mesh_path *mpath;
u8 ttl, flags, hopcount;
u8 *orig_addr;
u32 orig_sn, metric, metric_txsta, interval;
bool root_is_gate;
ttl = rann->rann_ttl;
flags = rann->rann_flags;
root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
orig_addr = rann->rann_addr;
orig_sn = le32_to_cpu(rann->rann_seq);
interval = le32_to_cpu(rann->rann_interval);
hopcount = rann->rann_hopcount;
hopcount++;
metric = le32_to_cpu(rann->rann_metric);
/* Ignore our own RANNs */
if (ether_addr_equal(orig_addr, sdata->vif.addr))
return;
mhwmp_dbg(sdata,
"received RANN from %pM via neighbour %pM (is_gate=%d)\n",
orig_addr, mgmt->sa, root_is_gate);
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (!sta) {
rcu_read_unlock();
return;
}
metric_txsta = airtime_link_metric_get(local, sta);
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
mesh_path_add(orig_addr, sdata);
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
return;
}
}
if (!(SN_LT(mpath->sn, orig_sn)) &&
!(mpath->sn == orig_sn && metric < mpath->rann_metric)) {
rcu_read_unlock();
return;
}
if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
(time_after(jiffies, mpath->last_preq_to_root +
root_path_confirmation_jiffies(sdata)) ||
time_before(jiffies, mpath->last_preq_to_root))) &&
!(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) {
mhwmp_dbg(sdata,
"time to refresh root mpath %pM\n",
orig_addr);
mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
mpath->last_preq_to_root = jiffies;
}
mpath->sn = orig_sn;
mpath->rann_metric = metric + metric_txsta;
mpath->is_root = true;
/* Recording RANNs sender address to send individually
* addressed PREQs destined for root mesh STA */
memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN);
if (root_is_gate)
mesh_path_add_gate(mpath);
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
rcu_read_unlock();
return;
}
ttl--;
if (ifmsh->mshcfg.dot11MeshForwarding) {
mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
cpu_to_le32(orig_sn),
0, NULL, 0, broadcast_addr,
hopcount, ttl, cpu_to_le32(interval),
cpu_to_le32(metric + metric_txsta),
0, sdata);
}
rcu_read_unlock();
}
static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
u8 *prep_elem, u32 metric)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 *target_addr, *orig_addr;
u8 ttl, hopcount, flags;
u8 next_hop[ETH_ALEN];
u32 target_sn, orig_sn, lifetime;
mhwmp_dbg(sdata, "received PREP from %pM\n",
PREP_IE_ORIG_ADDR(prep_elem));
orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
if (ether_addr_equal(orig_addr, sdata->vif.addr))
/* destination, no forwarding required */
return;
if (!ifmsh->mshcfg.dot11MeshForwarding)
return;
ttl = PREP_IE_TTL(prep_elem);
if (ttl <= 1) {
sdata->u.mesh.mshstats.dropped_frames_ttl++;
return;
}
rcu_read_lock();
mpath = mesh_path_lookup(orig_addr, sdata);
if (mpath)
spin_lock_bh(&mpath->state_lock);
else
goto fail;
if (!(mpath->flags & MESH_PATH_ACTIVE)) {
spin_unlock_bh(&mpath->state_lock);
goto fail;
}
memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
spin_unlock_bh(&mpath->state_lock);
--ttl;
flags = PREP_IE_FLAGS(prep_elem);
lifetime = PREP_IE_LIFETIME(prep_elem);
hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
target_addr = PREP_IE_TARGET_ADDR(prep_elem);
target_sn = PREP_IE_TARGET_SN(prep_elem);
orig_sn = PREP_IE_ORIG_SN(prep_elem);
mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
cpu_to_le32(orig_sn), 0, target_addr,
cpu_to_le32(target_sn), next_hop, hopcount,
ttl, cpu_to_le32(lifetime), cpu_to_le32(metric),
0, sdata);
rcu_read_unlock();
sdata->u.mesh.mshstats.fwded_unicast++;
sdata->u.mesh.mshstats.fwded_frames++;
return;
fail:
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
}
static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
u8 *preq_elem, u32 metric)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath = NULL;
u8 *target_addr, *orig_addr;
const u8 *da;
u8 target_flags, ttl, flags;
u32 orig_sn, target_sn, lifetime, orig_metric;
bool reply = false;
bool forward = true;
bool root_is_gate;
/* Update target SN, if present */
target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
target_sn = PREQ_IE_TARGET_SN(preq_elem);
orig_sn = PREQ_IE_ORIG_SN(preq_elem);
target_flags = PREQ_IE_TARGET_F(preq_elem);
orig_metric = metric;
/* Proactive PREQ gate announcements */
flags = PREQ_IE_FLAGS(preq_elem);
root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr);
if (ether_addr_equal(target_addr, sdata->vif.addr)) {
mhwmp_dbg(sdata, "PREQ is for us\n");
forward = false;
reply = true;
metric = 0;
if (time_after(jiffies, ifmsh->last_sn_update +
net_traversal_jiffies(sdata)) ||
time_before(jiffies, ifmsh->last_sn_update)) {
target_sn = ++ifmsh->sn;
ifmsh->last_sn_update = jiffies;
}
} else if (is_broadcast_ether_addr(target_addr) &&
(target_flags & IEEE80211_PREQ_TO_FLAG)) {
rcu_read_lock();
mpath = mesh_path_lookup(orig_addr, sdata);
if (mpath) {
if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
reply = true;
target_addr = sdata->vif.addr;
target_sn = ++ifmsh->sn;
metric = 0;
ifmsh->last_sn_update = jiffies;
}
if (root_is_gate)
mesh_path_add_gate(mpath);
}
rcu_read_unlock();
} else {
rcu_read_lock();
mpath = mesh_path_lookup(target_addr, sdata);
if (mpath) {
if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
SN_LT(mpath->sn, target_sn)) {
mpath->sn = target_sn;
mpath->flags |= MESH_PATH_SN_VALID;
} else if ((!(target_flags & MP_F_DO)) &&
(mpath->flags & MESH_PATH_ACTIVE)) {
reply = true;
metric = mpath->metric;
target_sn = mpath->sn;
if (target_flags & MP_F_RF)
target_flags |= MP_F_DO;
else
forward = false;
}
}
rcu_read_unlock();
}
if (reply) {
lifetime = PREQ_IE_LIFETIME(preq_elem);
ttl = ifmsh->mshcfg.element_ttl;
if (ttl != 0) {
mhwmp_dbg(sdata, "replying to the PREQ\n");
mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr,
cpu_to_le32(orig_sn), 0, target_addr,
cpu_to_le32(target_sn), mgmt->sa, 0, ttl,
cpu_to_le32(lifetime), cpu_to_le32(metric),
0, sdata);
} else {
ifmsh->mshstats.dropped_frames_ttl++;
}
}
if (forward && ifmsh->mshcfg.dot11MeshForwarding) {
u32 preq_id;
u8 hopcount;
ttl = PREQ_IE_TTL(preq_elem);
lifetime = PREQ_IE_LIFETIME(preq_elem);
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr);
--ttl;
preq_id = PREQ_IE_PREQ_ID(preq_elem);
hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
da = (mpath && mpath->is_root) ?
mpath->rann_snd_addr : broadcast_addr;
if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
target_sn = PREQ_IE_TARGET_SN(preq_elem);
metric = orig_metric;
}
mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
cpu_to_le32(orig_sn), target_flags, target_addr,
cpu_to_le32(target_sn), da,
hopcount, ttl, cpu_to_le32(lifetime),
cpu_to_le32(metric), cpu_to_le32(preq_id),
sdata);
if (!is_multicast_ether_addr(da))
ifmsh->mshstats.fwded_unicast++;
else
ifmsh->mshstats.fwded_mcast++;
ifmsh->mshstats.fwded_frames++;
}
}
static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
u8 *orig_addr, __le32 orig_sn, u8 target_flags, u8 *target,
__le32 target_sn, const u8 *da, u8 hop_count, u8 ttl,
__le32 lifetime, __le32 metric, __le32 preq_id,
struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
u8 *pos, ie_len;
int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) +
sizeof(mgmt->u.action.u.mesh_action);
skb = dev_alloc_skb(local->tx_headroom +
hdr_len +
2 + 37); /* max HWMP IE */
if (!skb)
return -1;
skb_reserve(skb, local->tx_headroom);
mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
memset(mgmt, 0, hdr_len);
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_ACTION);
memcpy(mgmt->da, da, ETH_ALEN);
memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
/* BSSID == SA */
memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
mgmt->u.action.u.mesh_action.action_code =
WLAN_MESH_ACTION_HWMP_PATH_SELECTION;
switch (action) {
case MPATH_PREQ:
mhwmp_dbg(sdata, "sending PREQ to %pM\n", target);
ie_len = 37;
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_PREQ;
break;
case MPATH_PREP:
mhwmp_dbg(sdata, "sending PREP to %pM\n", target);
ie_len = 31;
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_PREP;
break;
case MPATH_RANN:
mhwmp_dbg(sdata, "sending RANN from %pM\n", orig_addr);
ie_len = sizeof(struct ieee80211_rann_ie);
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_RANN;
break;
default:
kfree_skb(skb);
return -ENOTSUPP;
break;
}
*pos++ = ie_len;
*pos++ = flags;
*pos++ = hop_count;
*pos++ = ttl;
if (action == MPATH_PREP) {
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &target_sn, 4);
pos += 4;
} else {
if (action == MPATH_PREQ) {
memcpy(pos, &preq_id, 4);
pos += 4;
}
memcpy(pos, orig_addr, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &orig_sn, 4);
pos += 4;
}
memcpy(pos, &lifetime, 4); /* interval for RANN */
pos += 4;
memcpy(pos, &metric, 4);
pos += 4;
if (action == MPATH_PREQ) {
*pos++ = 1; /* destination count */
*pos++ = target_flags;
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &target_sn, 4);
pos += 4;
} else if (action == MPATH_PREP) {
memcpy(pos, orig_addr, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &orig_sn, 4);
pos += 4;
}
ieee80211_tx_skb(sdata, skb);
return 0;
}
static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
u8 *prep_elem, u32 metric)
{
struct mesh_path *mpath;
u8 *target_addr, *orig_addr;
u8 ttl, hopcount, flags;
u8 next_hop[ETH_ALEN];
u32 target_sn, orig_sn, lifetime;
mhwmp_dbg("received PREP from %pM\n", PREP_IE_ORIG_ADDR(prep_elem));
/* Note that we divert from the draft nomenclature and denominate
* destination to what the draft refers to as origininator. So in this
* function destnation refers to the final destination of the PREP,
* which corresponds with the originator of the PREQ which this PREP
* replies
*/
target_addr = PREP_IE_TARGET_ADDR(prep_elem);
if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0)
/* destination, no forwarding required */
return;
ttl = PREP_IE_TTL(prep_elem);
if (ttl <= 1) {
sdata->u.mesh.mshstats.dropped_frames_ttl++;
return;
}
rcu_read_lock();
mpath = mesh_path_lookup(target_addr, sdata);
if (mpath)
spin_lock_bh(&mpath->state_lock);
else
goto fail;
if (!(mpath->flags & MESH_PATH_ACTIVE)) {
spin_unlock_bh(&mpath->state_lock);
goto fail;
}
memcpy(next_hop, next_hop_deref_protected(mpath)->sta.addr, ETH_ALEN);
spin_unlock_bh(&mpath->state_lock);
--ttl;
flags = PREP_IE_FLAGS(prep_elem);
lifetime = PREP_IE_LIFETIME(prep_elem);
hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1;
orig_addr = PREP_IE_ORIG_ADDR(prep_elem);
target_sn = PREP_IE_TARGET_SN(prep_elem);
orig_sn = PREP_IE_ORIG_SN(prep_elem);
mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr,
cpu_to_le32(orig_sn), 0, target_addr,
cpu_to_le32(target_sn), next_hop, hopcount,
ttl, cpu_to_le32(lifetime), cpu_to_le32(metric),
0, sdata);
rcu_read_unlock();
sdata->u.mesh.mshstats.fwded_unicast++;
sdata->u.mesh.mshstats.fwded_frames++;
return;
fail:
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
}
static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
u8 *preq_elem, u32 metric)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 *target_addr, *orig_addr;
u8 target_flags, ttl;
u32 orig_sn, target_sn, lifetime;
bool reply = false;
bool forward = true;
/* Update target SN, if present */
target_addr = PREQ_IE_TARGET_ADDR(preq_elem);
orig_addr = PREQ_IE_ORIG_ADDR(preq_elem);
target_sn = PREQ_IE_TARGET_SN(preq_elem);
orig_sn = PREQ_IE_ORIG_SN(preq_elem);
target_flags = PREQ_IE_TARGET_F(preq_elem);
mhwmp_dbg("received PREQ from %pM\n", orig_addr);
if (memcmp(target_addr, sdata->vif.addr, ETH_ALEN) == 0) {
mhwmp_dbg("PREQ is for us\n");
forward = false;
reply = true;
metric = 0;
if (time_after(jiffies, ifmsh->last_sn_update +
net_traversal_jiffies(sdata)) ||
time_before(jiffies, ifmsh->last_sn_update)) {
target_sn = ++ifmsh->sn;
ifmsh->last_sn_update = jiffies;
}
} else {
rcu_read_lock();
mpath = mesh_path_lookup(target_addr, sdata);
if (mpath) {
if ((!(mpath->flags & MESH_PATH_SN_VALID)) ||
SN_LT(mpath->sn, target_sn)) {
mpath->sn = target_sn;
mpath->flags |= MESH_PATH_SN_VALID;
} else if ((!(target_flags & MP_F_DO)) &&
(mpath->flags & MESH_PATH_ACTIVE)) {
reply = true;
metric = mpath->metric;
target_sn = mpath->sn;
if (target_flags & MP_F_RF)
target_flags |= MP_F_DO;
else
forward = false;
}
}
rcu_read_unlock();
}
if (reply) {
lifetime = PREQ_IE_LIFETIME(preq_elem);
ttl = ifmsh->mshcfg.element_ttl;
if (ttl != 0) {
mhwmp_dbg("replying to the PREQ\n");
mesh_path_sel_frame_tx(MPATH_PREP, 0, target_addr,
cpu_to_le32(target_sn), 0, orig_addr,
cpu_to_le32(orig_sn), mgmt->sa, 0, ttl,
cpu_to_le32(lifetime), cpu_to_le32(metric),
0, sdata);
} else
ifmsh->mshstats.dropped_frames_ttl++;
}
if (forward) {
u32 preq_id;
u8 hopcount, flags;
ttl = PREQ_IE_TTL(preq_elem);
lifetime = PREQ_IE_LIFETIME(preq_elem);
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
mhwmp_dbg("forwarding the PREQ from %pM\n", orig_addr);
--ttl;
flags = PREQ_IE_FLAGS(preq_elem);
preq_id = PREQ_IE_PREQ_ID(preq_elem);
hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1;
mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
cpu_to_le32(orig_sn), target_flags, target_addr,
cpu_to_le32(target_sn), broadcast_addr,
hopcount, ttl, cpu_to_le32(lifetime),
cpu_to_le32(metric), cpu_to_le32(preq_id),
sdata);
ifmsh->mshstats.fwded_mcast++;
ifmsh->mshstats.fwded_frames++;
}
}
static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
struct ieee80211_rann_ie *rann)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 ttl, flags, hopcount;
u8 *orig_addr;
u32 orig_sn, metric;
u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
bool root_is_gate;
ttl = rann->rann_ttl;
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
ttl--;
flags = rann->rann_flags;
root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
orig_addr = rann->rann_addr;
orig_sn = rann->rann_seq;
hopcount = rann->rann_hopcount;
hopcount++;
metric = rann->rann_metric;
if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0)
return;
mhwmp_dbg("received RANN from %pM (is_gate=%d)", orig_addr,
root_is_gate);
rcu_read_lock();
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
mesh_path_add(orig_addr, sdata);
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
return;
}
}
if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
time_after(jiffies, mpath->exp_time - 1*HZ)) &&
!(mpath->flags & MESH_PATH_FIXED)) {
mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name,
orig_addr);
mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
}
if (mpath->sn < orig_sn) {
mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
cpu_to_le32(orig_sn),
0, NULL, 0, broadcast_addr,
hopcount, ttl, cpu_to_le32(interval),
cpu_to_le32(metric + mpath->metric),
0, sdata);
mpath->sn = orig_sn;
}
if (root_is_gate)
mesh_path_add_gate(mpath);
rcu_read_unlock();
}
/**
* hwmp_route_info_get - Update routing info to originator and transmitter
*
* @sdata: local mesh subif
* @mgmt: mesh management frame
* @hwmp_ie: hwmp information element (PREP or PREQ)
*
* This function updates the path routing information to the originator and the
* transmitter of a HWMP PREQ or PREP frame.
*
* Returns: metric to frame originator or 0 if the frame should not be further
* processed
*
* Notes: this function is the only place (besides user-provided info) where
* path routing information is updated.
*/
static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
u8 *hwmp_ie, enum mpath_frame_type action)
{
struct ieee80211_local *local = sdata->local;
struct mesh_path *mpath;
struct sta_info *sta;
bool fresh_info;
u8 *orig_addr, *ta;
u32 orig_sn, orig_metric;
unsigned long orig_lifetime, exp_time;
u32 last_hop_metric, new_metric;
bool process = true;
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (!sta) {
rcu_read_unlock();
return 0;
}
last_hop_metric = airtime_link_metric_get(local, sta);
/* Update and check originator routing info */
fresh_info = true;
switch (action) {
case MPATH_PREQ:
orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie);
orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
orig_metric = PREQ_IE_METRIC(hwmp_ie);
break;
case MPATH_PREP:
/* Originator here refers to the MP that was the destination in
* the Path Request. The draft refers to that MP as the
* destination address, even though usually it is the origin of
* the PREP frame. We divert from the nomenclature in the draft
* so that we can easily use a single function to gather path
* information from both PREQ and PREP frames.
*/
orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie);
orig_sn = PREP_IE_ORIG_SN(hwmp_ie);
orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
orig_metric = PREP_IE_METRIC(hwmp_ie);
break;
default:
rcu_read_unlock();
return 0;
}
new_metric = orig_metric + last_hop_metric;
if (new_metric < orig_metric)
new_metric = MAX_METRIC;
exp_time = TU_TO_EXP_TIME(orig_lifetime);
if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0) {
/* This MP is the originator, we are not interested in this
* frame, except for updating transmitter's path info.
*/
process = false;
fresh_info = false;
} else {
mpath = mesh_path_lookup(orig_addr, sdata);
if (mpath) {
spin_lock_bh(&mpath->state_lock);
if (mpath->flags & MESH_PATH_FIXED)
fresh_info = false;
else if ((mpath->flags & MESH_PATH_ACTIVE) &&
(mpath->flags & MESH_PATH_SN_VALID)) {
if (SN_GT(mpath->sn, orig_sn) ||
(mpath->sn == orig_sn &&
new_metric >= mpath->metric)) {
process = false;//ymj
fresh_info = false;
}
if(0 < orig_metric < (min_metric/5))
{
mhwmp_dbg("mesh hwmp: get orig_metric = %d\n",orig_metric);//ymj
process = false;
fresh_info = false;
}
}
} else {
mesh_path_add(orig_addr, sdata);
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
rcu_read_unlock();
return 0;
}
spin_lock_bh(&mpath->state_lock);
}
if (fresh_info) {
mesh_path_assign_nexthop(mpath, sta);
mpath->flags |= MESH_PATH_SN_VALID;
mpath->metric = new_metric;
mpath->sn = orig_sn;
mpath->exp_time = time_after(mpath->exp_time, exp_time)
? mpath->exp_time : exp_time;
mesh_path_activate(mpath);
spin_unlock_bh(&mpath->state_lock);
mesh_path_tx_pending(mpath);
/* draft says preq_id should be saved to, but there does
* not seem to be any use for it, skipping by now
*/
} else
spin_unlock_bh(&mpath->state_lock);
}
/* Update and check transmitter routing info */
ta = mgmt->sa;
if (memcmp(orig_addr, ta, ETH_ALEN) == 0)
fresh_info = false;
else {
fresh_info = true;
mpath = mesh_path_lookup(ta, sdata);
if (mpath) {
spin_lock_bh(&mpath->state_lock);
if ((mpath->flags & MESH_PATH_FIXED) ||
((mpath->flags & MESH_PATH_ACTIVE) &&
(last_hop_metric > mpath->metric)))
fresh_info = false;
} else {
mesh_path_add(ta, sdata);
mpath = mesh_path_lookup(ta, sdata);
if (!mpath) {
rcu_read_unlock();
return 0;
}
spin_lock_bh(&mpath->state_lock);
}
if (fresh_info) {
mesh_path_assign_nexthop(mpath, sta);
mpath->metric = last_hop_metric;
mpath->exp_time = time_after(mpath->exp_time, exp_time)
? mpath->exp_time : exp_time;
mesh_path_activate(mpath);
spin_unlock_bh(&mpath->state_lock);
mesh_path_tx_pending(mpath);
} else
spin_unlock_bh(&mpath->state_lock);
}
rcu_read_unlock();
return process ? new_metric : 0;
}
