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linux/net/mac80211/mesh_hwmp.c

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/*
* Copyright (c) 2008, 2009 open80211s Ltd.
* Author: Luis Carlos Cobo <luisca@cozybit.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include "mesh.h"
#ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG
#define mhwmp_dbg(fmt, args...) printk(KERN_DEBUG "Mesh HWMP: " fmt, ##args)
#else
#define mhwmp_dbg(fmt, args...) do { (void)(0); } while (0)
#endif
#define TEST_FRAME_LEN 8192
#define MAX_METRIC 0xffffffff
#define ARITH_SHIFT 8
/* Number of frames buffered per destination for unresolved destinations */
#define MESH_FRAME_QUEUE_LEN 10
#define MAX_PREQ_QUEUE_LEN 64
/* Destination only */
#define MP_F_DO 0x1
/* Reply and forward */
#define MP_F_RF 0x2
/* Unknown Sequence Number */
#define MP_F_USN 0x01
/* Reason code Present */
#define MP_F_RCODE 0x02
static void mesh_queue_preq(struct mesh_path *, u8);
static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
{
if (ae)
offset += 6;
return get_unaligned_le32(preq_elem + offset);
}
static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
{
if (ae)
offset += 6;
return get_unaligned_le16(preq_elem + offset);
}
/* HWMP IE processing macros */
#define AE_F (1<<6)
#define AE_F_SET(x) (*x & AE_F)
#define PREQ_IE_FLAGS(x) (*(x))
#define PREQ_IE_HOPCOUNT(x) (*(x + 1))
#define PREQ_IE_TTL(x) (*(x + 2))
#define PREQ_IE_PREQ_ID(x) u32_field_get(x, 3, 0)
#define PREQ_IE_ORIG_ADDR(x) (x + 7)
#define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0);
#define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x));
#define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x));
#define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26))
#define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27)
#define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x));
#define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x)
#define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x)
#define PREP_IE_TTL(x) PREQ_IE_TTL(x)
#define PREP_IE_ORIG_ADDR(x) (x + 3)
#define PREP_IE_ORIG_SN(x) u32_field_get(x, 9, 0);
#define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x));
#define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x));
#define PREP_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
#define PREP_IE_TARGET_SN(x) u32_field_get(x, 27, AE_F_SET(x));
#define PERR_IE_TTL(x) (*(x))
#define PERR_IE_TARGET_FLAGS(x) (*(x + 2))
#define PERR_IE_TARGET_ADDR(x) (x + 3)
#define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0);
#define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0);
#define MSEC_TO_TU(x) (x*1000/1024)
#define SN_GT(x, y) ((long) (y) - (long) (x) < 0)
#define SN_LT(x, y) ((long) (x) - (long) (y) < 0)
#define net_traversal_jiffies(s) \
msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
#define default_lifetime(s) \
MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout)
#define min_preq_int_jiff(s) \
(msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval))
#define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
#define disc_timeout_jiff(s) \
msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
enum mpath_frame_type {
MPATH_PREQ = 0,
MPATH_PREP,
MPATH_PERR,
MPATH_RANN
};
static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
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 = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
struct ieee80211_mgmt *mgmt;
u8 *pos;
int ie_len;
if (!skb)
return -1;
skb_reserve(skb, local->hw.extra_tx_headroom);
/* 25 is the size of the common mgmt part (24) plus the size of the
* common action part (1)
*/
mgmt = (struct ieee80211_mgmt *)
skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
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_PATH_SEL;
mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;
switch (action) {
case MPATH_PREQ:
mhwmp_dbg("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("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("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_PREQ) {
memcpy(pos, &preq_id, 4);
pos += 4;
}
memcpy(pos, orig_addr, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &orig_sn, 4);
pos += 4;
if (action != MPATH_RANN) {
memcpy(pos, &lifetime, 4);
pos += 4;
}
memcpy(pos, &metric, 4);
pos += 4;
if (action == MPATH_PREQ) {
/* destination count */
*pos++ = 1;
*pos++ = target_flags;
}
if (action != MPATH_RANN) {
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &target_sn, 4);
}
ieee80211_tx_skb(sdata, skb);
return 0;
}
/**
* mesh_send_path error - Sends a PERR mesh management frame
*
* @target: broken destination
* @target_sn: SN of the broken destination
* @target_rcode: reason code for this PERR
* @ra: node this frame is addressed to
*/
int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn,
__le16 target_rcode, const u8 *ra,
struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
struct ieee80211_mgmt *mgmt;
u8 *pos;
int ie_len;
if (!skb)
return -1;
skb_reserve(skb, local->hw.extra_tx_headroom);
/* 25 is the size of the common mgmt part (24) plus the size of the
* common action part (1)
*/
mgmt = (struct ieee80211_mgmt *)
skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action));
memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action));
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_ACTION);
memcpy(mgmt->da, ra, ETH_ALEN);
memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
/* BSSID is left zeroed, wildcard value */
mgmt->u.action.category = WLAN_CATEGORY_MESH_PATH_SEL;
mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;
ie_len = 15;
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_PERR;
*pos++ = ie_len;
/* ttl */
*pos++ = MESH_TTL;
/* number of destinations */
*pos++ = 1;
/*
* flags bit, bit 1 is unset if we know the sequence number and
* bit 2 is set if we have a reason code
*/
*pos = 0;
if (!target_sn)
*pos |= MP_F_USN;
if (target_rcode)
*pos |= MP_F_RCODE;
pos++;
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &target_sn, 4);
pos += 4;
memcpy(pos, &target_rcode, 2);
ieee80211_tx_skb(sdata, skb);
return 0;
}
void ieee80211s_update_metric(struct ieee80211_local *local,
struct sta_info *stainfo, struct sk_buff *skb)
{
struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
int failed;
if (!ieee80211_is_data(hdr->frame_control))
return;
failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
/* moving average, scaled to 100 */
stainfo->fail_avg = ((80 * stainfo->fail_avg + 5) / 100 + 20 * failed);
if (stainfo->fail_avg > 95)
mesh_plink_broken(stainfo);
}
static u32 airtime_link_metric_get(struct ieee80211_local *local,
struct sta_info *sta)
{
struct ieee80211_supported_band *sband;
/* This should be adjusted for each device */
int device_constant = 1 << ARITH_SHIFT;
int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
int s_unit = 1 << ARITH_SHIFT;
int rate, err;
u32 tx_time, estimated_retx;
u64 result;
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
if (sta->fail_avg >= 100)
return MAX_METRIC;
if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
return MAX_METRIC;
err = (sta->fail_avg << ARITH_SHIFT) / 100;
/* bitrate is in units of 100 Kbps, while we need rate in units of
* 1Mbps. This will be corrected on tx_time computation.
*/
rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
tx_time = (device_constant + 10 * test_frame_len / rate);
estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
return (u32)result;
}
/**
* 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 &&
action == MPATH_PREQ &&
new_metric >= mpath->metric)) {
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->flags &= ~MESH_PATH_SN_VALID;
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;
}
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.dot11MeshTTL;
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_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, mpath->next_hop->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++;
return;
}
static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, u8 *perr_elem)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 ttl;
u8 *ta, *target_addr;
u8 target_flags;
u32 target_sn;
u16 target_rcode;
ta = mgmt->sa;
ttl = PERR_IE_TTL(perr_elem);
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
ttl--;
target_flags = PERR_IE_TARGET_FLAGS(perr_elem);
target_addr = PERR_IE_TARGET_ADDR(perr_elem);
target_sn = PERR_IE_TARGET_SN(perr_elem);
target_rcode = PERR_IE_TARGET_RCODE(perr_elem);
rcu_read_lock();
mpath = mesh_path_lookup(target_addr, sdata);
if (mpath) {
spin_lock_bh(&mpath->state_lock);
if (mpath->flags & MESH_PATH_ACTIVE &&
memcmp(ta, mpath->next_hop->sta.addr, ETH_ALEN) == 0 &&
(!(mpath->flags & MESH_PATH_SN_VALID) ||
SN_GT(target_sn, mpath->sn))) {
mpath->flags &= ~MESH_PATH_ACTIVE;
mpath->sn = target_sn;
spin_unlock_bh(&mpath->state_lock);
mesh_path_error_tx(ttl, target_addr, cpu_to_le32(target_sn),
cpu_to_le16(target_rcode),
broadcast_addr, sdata);
} else
spin_unlock_bh(&mpath->state_lock);
}
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 mesh_path *mpath;
u8 *ta;
u8 ttl, flags, hopcount;
u8 *orig_addr;
u32 orig_sn, metric;
ta = mgmt->sa;
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();
}
void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len)
{
struct ieee802_11_elems elems;
size_t baselen;
u32 last_hop_metric;
/* need action_code */
if (len < IEEE80211_MIN_ACTION_SIZE + 1)
return;
baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
len - baselen, &elems);
if (elems.preq) {
if (elems.preq_len != 37)
/* Right now we support just 1 destination and no AE */
return;
last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
MPATH_PREQ);
if (last_hop_metric)
hwmp_preq_frame_process(sdata, mgmt, elems.preq,
last_hop_metric);
}
if (elems.prep) {
if (elems.prep_len != 31)
/* Right now we support no AE */
return;
last_hop_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
MPATH_PREP);
if (last_hop_metric)
hwmp_prep_frame_process(sdata, mgmt, elems.prep,
last_hop_metric);
}
if (elems.perr) {
if (elems.perr_len != 15)
/* Right now we support only one destination per PERR */
return;
hwmp_perr_frame_process(sdata, mgmt, elems.perr);
}
if (elems.rann)
hwmp_rann_frame_process(sdata, mgmt, elems.rann);
}
/**
* 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("could not allocate PREQ node\n");
return;
}
spin_lock(&ifmsh->mesh_preq_queue_lock);
if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) {
spin_unlock(&ifmsh->mesh_preq_queue_lock);
kfree(preq_node);
if (printk_ratelimit())
mhwmp_dbg("PREQ node queue full\n");
return;
}
memcpy(preq_node->dst, mpath->dst, ETH_ALEN);
preq_node->flags = flags;
list_add_tail(&preq_node->list, &ifmsh->preq_queue.list);
++ifmsh->preq_queue_len;
spin_unlock(&ifmsh->mesh_preq_queue_lock);
if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata)))
ieee80211_queue_work(&sdata->local->hw, &ifmsh->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, &ifmsh->work);
} else
mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq +
min_preq_int_jiff(sdata));
}
/**
* mesh_path_start_discovery - launch a path discovery from the PREQ queue
*
* @sdata: local mesh subif
*/
void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_preq_queue *preq_node;
struct mesh_path *mpath;
u8 ttl, target_flags;
u32 lifetime;
spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
if (!ifmsh->preq_queue_len ||
time_before(jiffies, ifmsh->last_preq +
min_preq_int_jiff(sdata))) {
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
return;
}
preq_node = list_first_entry(&ifmsh->preq_queue.list,
struct mesh_preq_queue, list);
list_del(&preq_node->list);
--ifmsh->preq_queue_len;
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
rcu_read_lock();
mpath = mesh_path_lookup(preq_node->dst, sdata);
if (!mpath)
goto enddiscovery;
spin_lock_bh(&mpath->state_lock);
if (preq_node->flags & PREQ_Q_F_START) {
if (mpath->flags & MESH_PATH_RESOLVING) {
spin_unlock_bh(&mpath->state_lock);
goto enddiscovery;
} else {
mpath->flags &= ~MESH_PATH_RESOLVED;
mpath->flags |= MESH_PATH_RESOLVING;
mpath->discovery_retries = 0;
mpath->discovery_timeout = disc_timeout_jiff(sdata);
}
} else if (!(mpath->flags & MESH_PATH_RESOLVING) ||
mpath->flags & MESH_PATH_RESOLVED) {
mpath->flags &= ~MESH_PATH_RESOLVING;
spin_unlock_bh(&mpath->state_lock);
goto enddiscovery;
}
ifmsh->last_preq = jiffies;
if (time_after(jiffies, ifmsh->last_sn_update +
net_traversal_jiffies(sdata)) ||
time_before(jiffies, ifmsh->last_sn_update)) {
++ifmsh->sn;
sdata->u.mesh.last_sn_update = jiffies;
}
lifetime = default_lifetime(sdata);
ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
if (ttl == 0) {
sdata->u.mesh.mshstats.dropped_frames_ttl++;
spin_unlock_bh(&mpath->state_lock);
goto enddiscovery;
}
if (preq_node->flags & PREQ_Q_F_REFRESH)
target_flags = MP_F_DO;
else
target_flags = MP_F_RF;
spin_unlock_bh(&mpath->state_lock);
mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr,
cpu_to_le32(ifmsh->sn), target_flags, mpath->dst,
cpu_to_le32(mpath->sn), broadcast_addr, 0,
ttl, cpu_to_le32(lifetime), 0,
cpu_to_le32(ifmsh->preq_id++), sdata);
mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
enddiscovery:
rcu_read_unlock();
kfree(preq_node);
}
/**
* mesh_nexthop_lookup - put the appropriate next hop on a mesh frame
*
* @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.
*/
int mesh_nexthop_lookup(struct sk_buff *skb,
struct ieee80211_sub_if_data *sdata)
{
struct sk_buff *skb_to_free = NULL;
struct mesh_path *mpath;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
u8 *target_addr = hdr->addr3;
int err = 0;
rcu_read_lock();
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++;
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);
}
memcpy(hdr->addr1, mpath->next_hop->sta.addr, ETH_ALEN);
} 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 (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;
skb_queue_tail(&mpath->frame_queue, skb);
if (skb_to_free)
mesh_path_discard_frame(skb_to_free, sdata);
err = -ENOENT;
}
endlookup:
rcu_read_unlock();
return err;
}
void mesh_path_timer(unsigned long data)
{
struct ieee80211_sub_if_data *sdata;
struct mesh_path *mpath;
rcu_read_lock();
mpath = (struct mesh_path *) data;
mpath = rcu_dereference(mpath);
if (!mpath)
goto endmpathtimer;
sdata = mpath->sdata;
if (sdata->local->quiescing) {
rcu_read_unlock();
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);
else if (mpath->discovery_retries < max_preq_retries(sdata)) {
++mpath->discovery_retries;
mpath->discovery_timeout *= 2;
mesh_queue_preq(mpath, 0);
} else {
mpath->flags = 0;
mpath->exp_time = jiffies;
mesh_path_flush_pending(mpath);
}
spin_unlock_bh(&mpath->state_lock);
endmpathtimer:
rcu_read_unlock();
}
void
mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
mesh_path_sel_frame_tx(MPATH_RANN, 0, sdata->vif.addr,
cpu_to_le32(++ifmsh->sn),
0, NULL, 0, broadcast_addr,
0, MESH_TTL, 0, 0, 0, sdata);
}
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