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linux/net/mac80211/mesh_hwmp.c
Javier Cardona 45904f2165 nl80211/mac80211: define and allow configuring mesh element TTL 
The TTL in path selection information elements is different from
the mesh ttl used in mesh data frames.  Version 7.03 of the 11s
draft calls this ttl 'Element TTL'.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-06 16:01:28 -05:00

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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 <linux/slab.h>
#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++ = 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.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_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++;
}
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, &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));
}
/**
* 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.element_ttl;
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, sdata->u.mesh.mshcfg.element_ttl,
0, 0, 0, sdata);
}
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