linux/net/mac80211/mesh_hwmp.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2008, 2009 open80211s Ltd.
* Copyright (C) 2019 Intel Corporation
* Author: Luis Carlos Cobo <luisca@cozybit.com>
*/
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/etherdevice.h>
#include <asm/unaligned.h>
#include "wme.h"
#include "mesh.h"
#define TEST_FRAME_LEN 8192
#define MAX_METRIC 0xffffffff
#define ARITH_SHIFT 8
#define LINK_FAIL_THRESH 95
#define MAX_PREQ_QUEUE_LEN 64
static void mesh_queue_preq(struct mesh_path *, u8);
static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae)
{
if (ae)
offset += 6;
return get_unaligned_le32(preq_elem + offset);
}
static inline u16 u16_field_get(const 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) (AE_F_SET(x) ? x + 27 : x + 21)
#define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x))
#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) (x + 3)
#define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0)
#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) ((s32)(y - x) < 0)
#define SN_LT(x, y) ((s32)(x - y) < 0)
#define MAX_SANE_SN_DELTA 32
static inline u32 SN_DELTA(u32 x, u32 y)
{
return x >= y ? x - y : y - x;
}
#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)
#define root_path_confirmation_jiffies(s) \
msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval)
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,
const u8 *orig_addr, u32 orig_sn,
u8 target_flags, const u8 *target,
u32 target_sn, const u8 *da,
u8 hop_count, u8 ttl,
u32 lifetime, u32 metric, u32 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 = offsetofend(struct ieee80211_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 = skb_put_zero(skb, 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", orig_addr);
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;
}
*pos++ = ie_len;
*pos++ = flags;
*pos++ = hop_count;
*pos++ = ttl;
if (action == MPATH_PREP) {
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(target_sn, pos);
pos += 4;
} else {
if (action == MPATH_PREQ) {
put_unaligned_le32(preq_id, pos);
pos += 4;
}
memcpy(pos, orig_addr, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(orig_sn, pos);
pos += 4;
}
put_unaligned_le32(lifetime, pos); /* interval for RANN */
pos += 4;
put_unaligned_le32(metric, pos);
pos += 4;
if (action == MPATH_PREQ) {
*pos++ = 1; /* destination count */
*pos++ = target_flags;
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(target_sn, pos);
pos += 4;
} else if (action == MPATH_PREP) {
memcpy(pos, orig_addr, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(orig_sn, pos);
pos += 4;
}
ieee80211_tx_skb(sdata, skb);
return 0;
}
/* Headroom is not adjusted. Caller should ensure that skb has sufficient
* headroom in case the frame is encrypted. */
static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
mac80211: mesh power save basics Add routines to - maintain a PS mode for each peer and a non-peer PS mode - indicate own PS mode in transmitted frames - track neighbor STAs power modes - buffer frames when neighbors are in PS mode - add TIM and Awake Window IE to beacons - release frames in Mesh Peer Service Periods Add local_pm to sta_info to represent the link-specific power mode at this station towards the remote station. When a peer link is established, use the default power mode stored in mesh config. Update the PS status if the peering status of a neighbor changes. Maintain a mesh power mode for non-peer mesh STAs. Set the non-peer power mode to active mode during peering. Authenticated mesh peering is currently not working when either node is configured to be in power save mode. Indicate the current power mode in transmitted frames. Use QoS Nulls to indicate mesh power mode transitions. For performance reasons, calls to the function setting the frame flags are placed in HWMP routing routines, as there the STA pointer is already available. Add peer_pm to sta_info to represent the peer's link-specific power mode towards the local station. Add nonpeer_pm to represent the peer's power mode towards all non-peer stations. Track power modes based on received frames. Add the ps_data structure to ieee80211_if_mesh (for TIM map, PS neighbor counter and group-addressed frame buffer). Set WLAN_STA_PS flag for STA in PS mode to use the unicast frame buffering routines in the tx path. Update num_sta_ps to buffer and release group-addressed frames after DTIM beacons. Announce the awake window duration in beacons if in light or deep sleep mode towards any peer or non-peer. Create a TIM IE similarly to AP mode and add it to mesh beacons. Parse received Awake Window IEs and check TIM IEs for buffered frames. Release frames towards peers in mesh Peer Service Periods. Use the corresponding trigger frames and monitor the MPSP status. Append a QoS Null as trigger frame if neccessary to properly end the MPSP. Currently, in HT channels MPSPs behave imperfectly and show large delay spikes and frame losses. Signed-off-by: Marco Porsch <marco@cozybit.com> Signed-off-by: Ivan Bezyazychnyy <ivan.bezyazychnyy@gmail.com> Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-30 17:14:08 +00:00
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
skb_reset_mac_header(skb);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
/* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
skb_set_queue_mapping(skb, IEEE80211_AC_VO);
skb->priority = 7;
info->control.vif = &sdata->vif;
info->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
ieee80211_set_qos_hdr(sdata, skb);
mac80211: mesh power save basics Add routines to - maintain a PS mode for each peer and a non-peer PS mode - indicate own PS mode in transmitted frames - track neighbor STAs power modes - buffer frames when neighbors are in PS mode - add TIM and Awake Window IE to beacons - release frames in Mesh Peer Service Periods Add local_pm to sta_info to represent the link-specific power mode at this station towards the remote station. When a peer link is established, use the default power mode stored in mesh config. Update the PS status if the peering status of a neighbor changes. Maintain a mesh power mode for non-peer mesh STAs. Set the non-peer power mode to active mode during peering. Authenticated mesh peering is currently not working when either node is configured to be in power save mode. Indicate the current power mode in transmitted frames. Use QoS Nulls to indicate mesh power mode transitions. For performance reasons, calls to the function setting the frame flags are placed in HWMP routing routines, as there the STA pointer is already available. Add peer_pm to sta_info to represent the peer's link-specific power mode towards the local station. Add nonpeer_pm to represent the peer's power mode towards all non-peer stations. Track power modes based on received frames. Add the ps_data structure to ieee80211_if_mesh (for TIM map, PS neighbor counter and group-addressed frame buffer). Set WLAN_STA_PS flag for STA in PS mode to use the unicast frame buffering routines in the tx path. Update num_sta_ps to buffer and release group-addressed frames after DTIM beacons. Announce the awake window duration in beacons if in light or deep sleep mode towards any peer or non-peer. Create a TIM IE similarly to AP mode and add it to mesh beacons. Parse received Awake Window IEs and check TIM IEs for buffered frames. Release frames towards peers in mesh Peer Service Periods. Use the corresponding trigger frames and monitor the MPSP status. Append a QoS Null as trigger frame if neccessary to properly end the MPSP. Currently, in HT channels MPSPs behave imperfectly and show large delay spikes and frame losses. Signed-off-by: Marco Porsch <marco@cozybit.com> Signed-off-by: Ivan Bezyazychnyy <ivan.bezyazychnyy@gmail.com> Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-30 17:14:08 +00:00
ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
}
/**
* mesh_path_error_tx - Sends a PERR mesh management frame
*
* @ttl: allowed remaining hops
* @target: broken destination
* @target_sn: SN of the broken destination
* @target_rcode: reason code for this PERR
* @ra: node this frame is addressed to
* @sdata: local mesh subif
*
* Note: This function may be called with driver locks taken that the driver
* also acquires in the TX path. To avoid a deadlock we don't transmit the
* frame directly but add it to the pending queue instead.
*/
int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
u8 ttl, const u8 *target, u32 target_sn,
u16 target_rcode, const u8 *ra)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_mgmt *mgmt;
u8 *pos, ie_len;
int hdr_len = offsetofend(struct ieee80211_mgmt,
u.action.u.mesh_action);
if (time_before(jiffies, ifmsh->next_perr))
return -EAGAIN;
skb = dev_alloc_skb(local->tx_headroom +
sdata->encrypt_headroom +
IEEE80211_ENCRYPT_TAILROOM +
hdr_len +
2 + 15 /* PERR IE */);
if (!skb)
return -1;
skb_reserve(skb, local->tx_headroom + sdata->encrypt_headroom);
mgmt = skb_put_zero(skb, hdr_len);
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 == 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;
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 field has AE bit only as defined in
* sec 8.4.2.117 IEEE802.11-2012
*/
*pos = 0;
pos++;
memcpy(pos, target, ETH_ALEN);
pos += ETH_ALEN;
put_unaligned_le32(target_sn, pos);
pos += 4;
put_unaligned_le16(target_rcode, pos);
/* see note in function header */
prepare_frame_for_deferred_tx(sdata, skb);
ifmsh->next_perr = TU_TO_EXP_TIME(
ifmsh->mshcfg.dot11MeshHWMPperrMinInterval);
ieee80211_add_pending_skb(local, skb);
return 0;
}
void ieee80211s_update_metric(struct ieee80211_local *local,
struct sta_info *sta,
struct ieee80211_tx_status *st)
{
struct ieee80211_tx_info *txinfo = st->info;
int failed;
struct rate_info rinfo;
failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
/* moving average, scaled to 100.
* feed failure as 100 and success as 0
*/
ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100);
if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) >
LINK_FAIL_THRESH)
mesh_plink_broken(sta);
sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
ewma_mesh_tx_rate_avg_add(&sta->mesh->tx_rate_avg,
cfg80211_calculate_bitrate(&rinfo));
}
u32 airtime_link_metric_get(struct ieee80211_local *local,
struct sta_info *sta)
{
/* 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;
unsigned long fail_avg =
ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
if (sta->mesh->plink_state != NL80211_PLINK_ESTAB)
return MAX_METRIC;
/* Try to get rate based on HW/SW RC algorithm.
* Rate is returned in units of Kbps, correct this
* to comply with airtime calculation units
* Round up in case we get rate < 100Kbps
*/
rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100);
if (rate) {
err = 0;
} else {
if (fail_avg > LINK_FAIL_THRESH)
return MAX_METRIC;
rate = ewma_mesh_tx_rate_avg_read(&sta->mesh->tx_rate_avg);
if (WARN_ON(!rate))
return MAX_METRIC;
err = (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.
*/
tx_time = (device_constant + 10 * test_frame_len / rate);
estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
result = ((u64)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)
* @action: type of hwmp ie
*
* 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,
const 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;
const u8 *orig_addr, *ta;
u32 orig_sn, orig_metric;
unsigned long orig_lifetime, exp_time;
u32 last_hop_metric, new_metric;
bool process = true;
u8 hopcount;
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);
hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
break;
case MPATH_PREP:
/* Originator here refers to the MP that was the target in the
* Path Request. 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_TARGET_ADDR(hwmp_ie);
orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
orig_metric = PREP_IE_METRIC(hwmp_ie);
hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
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 (ether_addr_equal(orig_addr, sdata->vif.addr)) {
/* 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(sdata, orig_addr);
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 &&
(rcu_access_pointer(mpath->next_hop) !=
sta ?
mult_frac(new_metric, 10, 9) :
new_metric) >= mpath->metric)) {
process = false;
fresh_info = false;
}
} else if (!(mpath->flags & MESH_PATH_ACTIVE)) {
bool have_sn, newer_sn, bounced;
have_sn = mpath->flags & MESH_PATH_SN_VALID;
newer_sn = have_sn && SN_GT(orig_sn, mpath->sn);
bounced = have_sn &&
(SN_DELTA(orig_sn, mpath->sn) >
MAX_SANE_SN_DELTA);
if (!have_sn || newer_sn) {
/* if SN is newer than what we had
* then we can take it */;
} else if (bounced) {
/* if SN is way different than what
* we had then assume the other side
* rebooted or restarted */;
} else {
process = false;
fresh_info = false;
}
}
} else {
mpath = mesh_path_add(sdata, orig_addr);
if (IS_ERR(mpath)) {
rcu_read_unlock();
return 0;
}
spin_lock_bh(&mpath->state_lock);
}
if (fresh_info) {
if (rcu_access_pointer(mpath->next_hop) != sta)
mpath->path_change_count++;
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;
mpath->hop_count = hopcount;
mesh_path_activate(mpath);
spin_unlock_bh(&mpath->state_lock);
ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
/* init it at a low value - 0 start is tricky */
ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
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 (ether_addr_equal(orig_addr, ta))
fresh_info = false;
else {
fresh_info = true;
mpath = mesh_path_lookup(sdata, ta);
if (mpath) {
spin_lock_bh(&mpath->state_lock);
if ((mpath->flags & MESH_PATH_FIXED) ||
((mpath->flags & MESH_PATH_ACTIVE) &&
((rcu_access_pointer(mpath->next_hop) != sta ?
mult_frac(last_hop_metric, 10, 9) :
last_hop_metric) > mpath->metric)))
fresh_info = false;
} else {
mpath = mesh_path_add(sdata, ta);
if (IS_ERR(mpath)) {
rcu_read_unlock();
return 0;
}
spin_lock_bh(&mpath->state_lock);
}
if (fresh_info) {
if (rcu_access_pointer(mpath->next_hop) != sta)
mpath->path_change_count++;
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;
mpath->hop_count = 1;
mesh_path_activate(mpath);
spin_unlock_bh(&mpath->state_lock);
ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
/* init it at a low value - 0 start is tricky */
ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
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,
const u8 *preq_elem, u32 orig_metric)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath = NULL;
const u8 *target_addr, *orig_addr;
const u8 *da;
u8 target_flags, ttl, flags;
u32 orig_sn, target_sn, lifetime, target_metric = 0;
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);
/* 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;
target_metric = 0;
if (SN_GT(target_sn, ifmsh->sn))
ifmsh->sn = target_sn;
if (time_after(jiffies, ifmsh->last_sn_update +
net_traversal_jiffies(sdata)) ||
time_before(jiffies, ifmsh->last_sn_update)) {
++ifmsh->sn;
ifmsh->last_sn_update = jiffies;
}
target_sn = ifmsh->sn;
} else if (is_broadcast_ether_addr(target_addr) &&
(target_flags & IEEE80211_PREQ_TO_FLAG)) {
rcu_read_lock();
mpath = mesh_path_lookup(sdata, orig_addr);
if (mpath) {
if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) {
reply = true;
target_addr = sdata->vif.addr;
target_sn = ++ifmsh->sn;
target_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(sdata, target_addr);
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 & IEEE80211_PREQ_TO_FLAG)) &&
(mpath->flags & MESH_PATH_ACTIVE)) {
reply = true;
target_metric = mpath->metric;
target_sn = mpath->sn;
/* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/
target_flags |= IEEE80211_PREQ_TO_FLAG;
}
}
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,
orig_sn, 0, target_addr,
target_sn, mgmt->sa, 0, ttl,
lifetime, target_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);
}
mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr,
orig_sn, target_flags, target_addr,
target_sn, da, hopcount, ttl, lifetime,
orig_metric, preq_id, sdata);
if (!is_multicast_ether_addr(da))
ifmsh->mshstats.fwded_unicast++;
else
ifmsh->mshstats.fwded_mcast++;
ifmsh->mshstats.fwded_frames++;
}
}
static inline struct sta_info *
next_hop_deref_protected(struct mesh_path *mpath)
{
return rcu_dereference_protected(mpath->next_hop,
lockdep_is_held(&mpath->state_lock));
}
static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
const u8 *prep_elem, u32 metric)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
const 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_TARGET_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(sdata, orig_addr);
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, orig_sn, 0,
target_addr, target_sn, next_hop, hopcount,
ttl, lifetime, 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,
const u8 *perr_elem)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 ttl;
const u8 *ta, *target_addr;
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_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(sdata, target_addr);
if (mpath) {
struct sta_info *sta;
spin_lock_bh(&mpath->state_lock);
sta = next_hop_deref_protected(mpath);
if (mpath->flags & MESH_PATH_ACTIVE &&
ether_addr_equal(ta, sta->sta.addr) &&
!(mpath->flags & MESH_PATH_FIXED) &&
(!(mpath->flags & MESH_PATH_SN_VALID) ||
SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
mpath->flags &= ~MESH_PATH_ACTIVE;
if (target_sn != 0)
mpath->sn = target_sn;
else
mpath->sn += 1;
spin_unlock_bh(&mpath->state_lock);
if (!ifmsh->mshcfg.dot11MeshForwarding)
goto endperr;
mesh_path_error_tx(sdata, ttl, target_addr,
target_sn, target_rcode,
broadcast_addr);
} else
spin_unlock_bh(&mpath->state_lock);
}
endperr:
rcu_read_unlock();
}
static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
const 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;
const u8 *orig_addr;
u32 orig_sn, new_metric, orig_metric, last_hop_metric, 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++;
orig_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;
}
last_hop_metric = airtime_link_metric_get(local, sta);
new_metric = orig_metric + last_hop_metric;
if (new_metric < orig_metric)
new_metric = MAX_METRIC;
mpath = mesh_path_lookup(sdata, orig_addr);
if (!mpath) {
mpath = mesh_path_add(sdata, orig_addr);
if (IS_ERR(mpath)) {
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
return;
}
}
if (!(SN_LT(mpath->sn, orig_sn)) &&
!(mpath->sn == orig_sn && new_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 = new_metric;
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,
orig_sn, 0, NULL, 0, broadcast_addr,
hopcount, ttl, interval,
new_metric, 0, sdata);
}
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 path_metric;
struct sta_info *sta;
/* need action_code */
if (len < IEEE80211_MIN_ACTION_SIZE + 1)
return;
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
rcu_read_unlock();
return;
}
rcu_read_unlock();
baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt;
ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable,
len - baselen, false, &elems, mgmt->bssid, NULL);
if (elems.preq) {
if (elems.preq_len != 37)
/* Right now we support just 1 destination and no AE */
return;
path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq,
MPATH_PREQ);
if (path_metric)
hwmp_preq_frame_process(sdata, mgmt, elems.preq,
path_metric);
}
if (elems.prep) {
if (elems.prep_len != 31)
/* Right now we support no AE */
return;
path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep,
MPATH_PREP);
if (path_metric)
hwmp_prep_frame_process(sdata, mgmt, elems.prep,
path_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;
mac80211: fix allocation in mesh_queue_preq We allocate a PREQ queue node in mesh_queue_preq, however the allocation may cause us to sleep. Use GFP_ATOMIC to prevent this. [ 1869.126498] BUG: scheduling while atomic: ping/1859/0x10000100 [ 1869.127164] Modules linked in: ath5k mac80211 ath [ 1869.128310] Pid: 1859, comm: ping Not tainted 2.6.30-wl #1 [ 1869.128754] Call Trace: [ 1869.129293] [<c1023a2b>] __schedule_bug+0x48/0x4d [ 1869.129866] [<c13b5533>] __schedule+0x77/0x67a [ 1869.130544] [<c1026f2e>] ? release_console_sem+0x17d/0x185 [ 1869.131568] [<c807cf47>] ? mesh_queue_preq+0x2b/0x165 [mac80211] [ 1869.132318] [<c13b5b3e>] schedule+0x8/0x1f [ 1869.132807] [<c1023c12>] __cond_resched+0x16/0x2f [ 1869.133478] [<c13b5bf0>] _cond_resched+0x27/0x32 [ 1869.134191] [<c108a370>] kmem_cache_alloc+0x1c/0xcf [ 1869.134714] [<c10273ae>] ? printk+0x15/0x17 [ 1869.135670] [<c807cf47>] mesh_queue_preq+0x2b/0x165 [mac80211] [ 1869.136731] [<c807d1f8>] mesh_nexthop_lookup+0xee/0x12d [mac80211] [ 1869.138130] [<c807417e>] ieee80211_xmit+0xe6/0x2b2 [mac80211] [ 1869.138935] [<c80be46d>] ? ath5k_hw_setup_rx_desc+0x0/0x66 [ath5k] [ 1869.139831] [<c80c97bc>] ? ath5k_tasklet_rx+0xba/0x506 [ath5k] [ 1869.140863] [<c8075191>] ieee80211_subif_start_xmit+0x6c9/0x6e4 [mac80211] [ 1869.141665] [<c105cf1c>] ? handle_level_irq+0x78/0x9d [ 1869.142390] [<c12e3f93>] dev_hard_start_xmit+0x168/0x1c7 [ 1869.143092] [<c12f1f17>] __qdisc_run+0xe1/0x1b7 [ 1869.143612] [<c12e25ff>] qdisc_run+0x18/0x1a [ 1869.144248] [<c12e62f4>] dev_queue_xmit+0x16a/0x25a [ 1869.144785] [<c13b6dcc>] ? _read_unlock_bh+0xe/0x10 [ 1869.145465] [<c12eacdb>] neigh_resolve_output+0x19c/0x1c7 [ 1869.146182] [<c130e2da>] ? ip_finish_output+0x0/0x51 [ 1869.146697] [<c130e2a0>] ip_finish_output2+0x182/0x1bc [ 1869.147358] [<c130e327>] ip_finish_output+0x4d/0x51 [ 1869.147863] [<c130e9d5>] ip_output+0x80/0x85 [ 1869.148515] [<c130cc49>] dst_output+0x9/0xb [ 1869.149141] [<c130dec6>] ip_local_out+0x17/0x1a [ 1869.149632] [<c130e0bc>] ip_push_pending_frames+0x1f3/0x255 [ 1869.150343] [<c13247ff>] raw_sendmsg+0x5e6/0x667 [ 1869.150883] [<c1033c55>] ? insert_work+0x6a/0x73 [ 1869.151834] [<c8071e00>] ? ieee80211_invoke_rx_handlers+0x17da/0x1ae8 [mac80211] [ 1869.152630] [<c132bd68>] inet_sendmsg+0x3b/0x48 [ 1869.153232] [<c12d7deb>] __sock_sendmsg+0x45/0x4e [ 1869.153740] [<c12d8537>] sock_sendmsg+0xb8/0xce [ 1869.154519] [<c80be46d>] ? ath5k_hw_setup_rx_desc+0x0/0x66 [ath5k] [ 1869.155289] [<c1036b25>] ? autoremove_wake_function+0x0/0x30 [ 1869.155859] [<c115992b>] ? __copy_from_user_ll+0x11/0xce [ 1869.156573] [<c1159d99>] ? copy_from_user+0x31/0x54 [ 1869.157235] [<c12df646>] ? verify_iovec+0x40/0x6e [ 1869.157778] [<c12d869a>] sys_sendmsg+0x14d/0x1a5 [ 1869.158714] [<c8072c40>] ? __ieee80211_rx+0x49e/0x4ee [mac80211] [ 1869.159641] [<c80c83fe>] ? ath5k_rxbuf_setup+0x6d/0x8d [ath5k] [ 1869.160543] [<c80be46d>] ? ath5k_hw_setup_rx_desc+0x0/0x66 [ath5k] [ 1869.161434] [<c80beba4>] ? ath5k_hw_get_rxdp+0xe/0x10 [ath5k] [ 1869.162319] [<c80c97bc>] ? ath5k_tasklet_rx+0xba/0x506 [ath5k] [ 1869.163063] [<c1005627>] ? enable_8259A_irq+0x40/0x43 [ 1869.163594] [<c101edb8>] ? __dequeue_entity+0x23/0x27 [ 1869.164793] [<c100187a>] ? __switch_to+0x2b/0x105 [ 1869.165442] [<c1021d5f>] ? finish_task_switch+0x5b/0x74 [ 1869.166129] [<c12d963a>] sys_socketcall+0x14b/0x17b [ 1869.166612] [<c1002b95>] syscall_call+0x7/0xb Signed-off-by: Andrey Yurovsky <andrey@cozybit.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-06-25 23:07:42 +00:00
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));
}
/**
* 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 = 0;
const u8 *da;
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(sdata, preq_node->dst);
if (!mpath)
goto enddiscovery;
spin_lock_bh(&mpath->state_lock);
if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) {
mac80211: mesh: fix crash in mesh_path_timer The mesh_path_reclaim() function, called from an rcu callback, cancels the mesh_path_timer associated with a mesh path. Unfortunately, this call can happen much later, perhaps after the hash table itself is destroyed. Such a situation led to the following crash in mesh_path_send_to_gates() when dereferencing the tbl pointer: [ 23.901661] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 23.905516] IP: [<ffffffff814c910b>] mesh_path_send_to_gates+0x2b/0x740 [ 23.908757] PGD 99ca067 PUD 99c4067 PMD 0 [ 23.910789] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 23.913485] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.5.0-rc6-wt+ #43 [ 23.916675] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 23.920471] task: ffffffff81685500 ti: ffffffff81678000 task.ti: ffffffff81678000 [ 23.922619] RIP: 0010:[<ffffffff814c910b>] [<ffffffff814c910b>] mesh_path_send_to_gates+0x2b/0x740 [ 23.925237] RSP: 0018:ffff88000b403d30 EFLAGS: 00010286 [ 23.926739] RAX: 0000000000000000 RBX: ffff880009bc0d20 RCX: 0000000000000102 [ 23.928796] RDX: 000000000000002e RSI: 0000000000000001 RDI: ffff880009bc0d20 [ 23.930895] RBP: ffff88000b403e18 R08: 0000000000000001 R09: 0000000000000001 [ 23.932917] R10: 0000000000000000 R11: 0000000000000001 R12: ffff880009c20940 [ 23.936370] R13: ffff880009bc0e70 R14: ffff880009c21c40 R15: ffff880009bc0d20 [ 23.939823] FS: 0000000000000000(0000) GS:ffff88000b400000(0000) knlGS:0000000000000000 [ 23.943688] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 23.946429] CR2: 0000000000000008 CR3: 00000000099c5000 CR4: 00000000000006b0 [ 23.949861] Stack: [ 23.950840] 000000000000002e ffff880009c20940 ffff88000b403da8 ffffffff8109e551 [ 23.954467] ffffffff82711be2 000000000000002e 0000000000000000 ffffffff8166a5f5 [ 23.958141] 0000000000685ce8 0000000000000246 ffff880009bc0d20 ffff880009c20940 [ 23.961801] Call Trace: [ 23.962987] <IRQ> [ 23.963963] [<ffffffff8109e551>] ? vprintk_emit+0x351/0x5e0 [ 23.966782] [<ffffffff8109e8ff>] ? vprintk_default+0x1f/0x30 [ 23.969529] [<ffffffff810ffa41>] ? printk+0x48/0x50 [ 23.971956] [<ffffffff814ceef3>] mesh_path_timer+0x133/0x160 [ 23.974707] [<ffffffff814cedc0>] ? mesh_nexthop_resolve+0x230/0x230 [ 23.977775] [<ffffffff810b04ee>] call_timer_fn+0xce/0x330 [ 23.980448] [<ffffffff810b0425>] ? call_timer_fn+0x5/0x330 [ 23.983126] [<ffffffff814cedc0>] ? mesh_nexthop_resolve+0x230/0x230 [ 23.986091] [<ffffffff810b097c>] run_timer_softirq+0x22c/0x390 Instead of cancelling in the RCU callback, set a new flag to prevent the timer from being rearmed, and then cancel the timer synchronously when freeing the mesh path. This leaves mesh_path_reclaim() doing nothing but kfree, so switch to kfree_rcu(). Fixes: 3b302ada7f0a ("mac80211: mesh: move path tables into if_mesh") Signed-off-by: Bob Copeland <me@bobcopeland.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-03-19 02:03:24 +00:00
spin_unlock_bh(&mpath->state_lock);
goto enddiscovery;
}
mpath->flags &= ~MESH_PATH_REQ_QUEUED;
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 |= IEEE80211_PREQ_TO_FLAG;
else
target_flags &= ~IEEE80211_PREQ_TO_FLAG;
spin_unlock_bh(&mpath->state_lock);
da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr;
mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn,
target_flags, mpath->dst, mpath->sn, da, 0,
ttl, lifetime, 0, ifmsh->preq_id++, sdata);
mac80211: mesh: fix discovery timer re-arming issue / crash On a non-forwarding 802.11s link between two fairly busy neighboring nodes (iperf with -P 16 at ~850MBit/s TCP; 1733.3 MBit/s VHT-MCS 9 80MHz short GI VHT-NSS 4), so with frequent PREQ retries, usually after around 30-40 seconds the following crash would occur: [ 1110.822428] Unable to handle kernel read from unreadable memory at virtual address 00000000 [ 1110.830786] Mem abort info: [ 1110.833573] Exception class = IABT (current EL), IL = 32 bits [ 1110.839494] SET = 0, FnV = 0 [ 1110.842546] EA = 0, S1PTW = 0 [ 1110.845678] user pgtable: 4k pages, 48-bit VAs, pgd = ffff800076386000 [ 1110.852204] [0000000000000000] *pgd=00000000f6322003, *pud=00000000f62de003, *pmd=0000000000000000 [ 1110.861167] Internal error: Oops: 86000004 [#1] PREEMPT SMP [ 1110.866730] Modules linked in: pppoe ppp_async batman_adv ath10k_pci ath10k_core ath pppox ppp_generic nf_conntrack_ipv6 mac80211 iptable_nat ipt_REJECT ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_state xt_nat xt_multiport xt_mark xt_mac xt_limit xt_conntrack xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_FLOWOFFLOAD slhc nf_reject_ipv4 nf_nat_redirect nf_nat_masquerade_ipv4 nf_conntrack_ipv4 nf_nat_ipv4 nf_nat nf_log_ipv4 nf_flow_table_hw nf_flow_table nf_defrag_ipv6 nf_defrag_ipv4 nf_conntrack_rtcache nf_conntrack iptable_mangle iptable_filter ip_tables crc_ccitt compat nf_log_ipv6 nf_log_common ip6table_mangle ip6table_filter ip6_tables ip6t_REJECT x_tables nf_reject_ipv6 usb_storage xhci_plat_hcd xhci_pci xhci_hcd dwc3 usbcore usb_common [ 1110.932190] Process swapper/3 (pid: 0, stack limit = 0xffff0000090c8000) [ 1110.938884] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.14.162 #0 [ 1110.944965] Hardware name: LS1043A RGW Board (DT) [ 1110.949658] task: ffff8000787a81c0 task.stack: ffff0000090c8000 [ 1110.955568] PC is at 0x0 [ 1110.958097] LR is at call_timer_fn.isra.27+0x24/0x78 [ 1110.963055] pc : [<0000000000000000>] lr : [<ffff0000080ff29c>] pstate: 00400145 [ 1110.970440] sp : ffff00000801be10 [ 1110.973744] x29: ffff00000801be10 x28: ffff000008bf7018 [ 1110.979047] x27: ffff000008bf87c8 x26: ffff000008c160c0 [ 1110.984352] x25: 0000000000000000 x24: 0000000000000000 [ 1110.989657] x23: dead000000000200 x22: 0000000000000000 [ 1110.994959] x21: 0000000000000000 x20: 0000000000000101 [ 1111.000262] x19: ffff8000787a81c0 x18: 0000000000000000 [ 1111.005565] x17: ffff0000089167b0 x16: 0000000000000058 [ 1111.010868] x15: ffff0000089167b0 x14: 0000000000000000 [ 1111.016172] x13: ffff000008916788 x12: 0000000000000040 [ 1111.021475] x11: ffff80007fda9af0 x10: 0000000000000001 [ 1111.026777] x9 : ffff00000801bea0 x8 : 0000000000000004 [ 1111.032080] x7 : 0000000000000000 x6 : ffff80007fda9aa8 [ 1111.037383] x5 : ffff00000801bea0 x4 : 0000000000000010 [ 1111.042685] x3 : ffff00000801be98 x2 : 0000000000000614 [ 1111.047988] x1 : 0000000000000000 x0 : 0000000000000000 [ 1111.053290] Call trace: [ 1111.055728] Exception stack(0xffff00000801bcd0 to 0xffff00000801be10) [ 1111.062158] bcc0: 0000000000000000 0000000000000000 [ 1111.069978] bce0: 0000000000000614 ffff00000801be98 0000000000000010 ffff00000801bea0 [ 1111.077798] bd00: ffff80007fda9aa8 0000000000000000 0000000000000004 ffff00000801bea0 [ 1111.085618] bd20: 0000000000000001 ffff80007fda9af0 0000000000000040 ffff000008916788 [ 1111.093437] bd40: 0000000000000000 ffff0000089167b0 0000000000000058 ffff0000089167b0 [ 1111.101256] bd60: 0000000000000000 ffff8000787a81c0 0000000000000101 0000000000000000 [ 1111.109075] bd80: 0000000000000000 dead000000000200 0000000000000000 0000000000000000 [ 1111.116895] bda0: ffff000008c160c0 ffff000008bf87c8 ffff000008bf7018 ffff00000801be10 [ 1111.124715] bdc0: ffff0000080ff29c ffff00000801be10 0000000000000000 0000000000400145 [ 1111.132534] bde0: ffff8000787a81c0 ffff00000801bde8 0000ffffffffffff 000001029eb19be8 [ 1111.140353] be00: ffff00000801be10 0000000000000000 [ 1111.145220] [< (null)>] (null) [ 1111.149917] [<ffff0000080ff77c>] run_timer_softirq+0x184/0x398 [ 1111.155741] [<ffff000008081938>] __do_softirq+0x100/0x1fc [ 1111.161130] [<ffff0000080a2e28>] irq_exit+0x80/0xd8 [ 1111.166002] [<ffff0000080ea708>] __handle_domain_irq+0x88/0xb0 [ 1111.171825] [<ffff000008081678>] gic_handle_irq+0x68/0xb0 [ 1111.177213] Exception stack(0xffff0000090cbe30 to 0xffff0000090cbf70) [ 1111.183642] be20: 0000000000000020 0000000000000000 [ 1111.191461] be40: 0000000000000001 0000000000000000 00008000771af000 0000000000000000 [ 1111.199281] be60: ffff000008c95180 0000000000000000 ffff000008c19360 ffff0000090cbef0 [ 1111.207101] be80: 0000000000000810 0000000000000400 0000000000000098 ffff000000000000 [ 1111.214920] bea0: 0000000000000001 ffff0000089167b0 0000000000000000 ffff0000089167b0 [ 1111.222740] bec0: 0000000000000000 ffff000008c198e8 ffff000008bf7018 ffff000008c19000 [ 1111.230559] bee0: 0000000000000000 0000000000000000 ffff8000787a81c0 ffff000008018000 [ 1111.238380] bf00: ffff00000801c000 ffff00000913ba34 ffff8000787a81c0 ffff0000090cbf70 [ 1111.246199] bf20: ffff0000080857cc ffff0000090cbf70 ffff0000080857d0 0000000000400145 [ 1111.254020] bf40: ffff000008018000 ffff00000801c000 ffffffffffffffff ffff0000080fa574 [ 1111.261838] bf60: ffff0000090cbf70 ffff0000080857d0 [ 1111.266706] [<ffff0000080832e8>] el1_irq+0xe8/0x18c [ 1111.271576] [<ffff0000080857d0>] arch_cpu_idle+0x10/0x18 [ 1111.276880] [<ffff0000080d7de4>] do_idle+0xec/0x1b8 [ 1111.281748] [<ffff0000080d8020>] cpu_startup_entry+0x20/0x28 [ 1111.287399] [<ffff00000808f81c>] secondary_start_kernel+0x104/0x110 [ 1111.293662] Code: bad PC value [ 1111.296710] ---[ end trace 555b6ca4363c3edd ]--- [ 1111.301318] Kernel panic - not syncing: Fatal exception in interrupt [ 1111.307661] SMP: stopping secondary CPUs [ 1111.311574] Kernel Offset: disabled [ 1111.315053] CPU features: 0x0002000 [ 1111.318530] Memory Limit: none [ 1111.321575] Rebooting in 3 seconds.. With some added debug output / delays we were able to push the crash from the timer callback runner into the callback function and by that shedding some light on which object holding the timer gets corrupted: [ 401.720899] Unable to handle kernel read from unreadable memory at virtual address 00000868 [...] [ 402.335836] [<ffff0000088fafa4>] _raw_spin_lock_bh+0x14/0x48 [ 402.341548] [<ffff000000dbe684>] mesh_path_timer+0x10c/0x248 [mac80211] [ 402.348154] [<ffff0000080ff29c>] call_timer_fn.isra.27+0x24/0x78 [ 402.354150] [<ffff0000080ff77c>] run_timer_softirq+0x184/0x398 [ 402.359974] [<ffff000008081938>] __do_softirq+0x100/0x1fc [ 402.365362] [<ffff0000080a2e28>] irq_exit+0x80/0xd8 [ 402.370231] [<ffff0000080ea708>] __handle_domain_irq+0x88/0xb0 [ 402.376053] [<ffff000008081678>] gic_handle_irq+0x68/0xb0 The issue happens due to the following sequence of events: 1) mesh_path_start_discovery(): -> spin_unlock_bh(&mpath->state_lock) before mesh_path_sel_frame_tx() 2) mesh_path_free_rcu() -> del_timer_sync(&mpath->timer) [...] -> kfree_rcu(mpath) 3) mesh_path_start_discovery(): -> mod_timer(&mpath->timer, ...) [...] -> rcu_read_unlock() 4) mesh_path_free_rcu()'s kfree_rcu(): -> kfree(mpath) 5) mesh_path_timer() starts after timeout, using freed mpath object So a use-after-free issue due to a timer re-arming bug caused by an early spin-unlocking. This patch fixes this issue by re-checking if mpath is about to be free'd and if so bails out of re-arming the timer. Cc: stable@vger.kernel.org Fixes: 050ac52cbe1f ("mac80211: code for on-demand Hybrid Wireless Mesh Protocol") Cc: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Linus Lüssing <ll@simonwunderlich.de> Link: https://lore.kernel.org/r/20200522170413.14973-1-linus.luessing@c0d3.blue Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-05-22 17:04:13 +00:00
spin_lock_bh(&mpath->state_lock);
if (!(mpath->flags & MESH_PATH_DELETED))
mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout);
mac80211: mesh: fix discovery timer re-arming issue / crash On a non-forwarding 802.11s link between two fairly busy neighboring nodes (iperf with -P 16 at ~850MBit/s TCP; 1733.3 MBit/s VHT-MCS 9 80MHz short GI VHT-NSS 4), so with frequent PREQ retries, usually after around 30-40 seconds the following crash would occur: [ 1110.822428] Unable to handle kernel read from unreadable memory at virtual address 00000000 [ 1110.830786] Mem abort info: [ 1110.833573] Exception class = IABT (current EL), IL = 32 bits [ 1110.839494] SET = 0, FnV = 0 [ 1110.842546] EA = 0, S1PTW = 0 [ 1110.845678] user pgtable: 4k pages, 48-bit VAs, pgd = ffff800076386000 [ 1110.852204] [0000000000000000] *pgd=00000000f6322003, *pud=00000000f62de003, *pmd=0000000000000000 [ 1110.861167] Internal error: Oops: 86000004 [#1] PREEMPT SMP [ 1110.866730] Modules linked in: pppoe ppp_async batman_adv ath10k_pci ath10k_core ath pppox ppp_generic nf_conntrack_ipv6 mac80211 iptable_nat ipt_REJECT ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_state xt_nat xt_multiport xt_mark xt_mac xt_limit xt_conntrack xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_FLOWOFFLOAD slhc nf_reject_ipv4 nf_nat_redirect nf_nat_masquerade_ipv4 nf_conntrack_ipv4 nf_nat_ipv4 nf_nat nf_log_ipv4 nf_flow_table_hw nf_flow_table nf_defrag_ipv6 nf_defrag_ipv4 nf_conntrack_rtcache nf_conntrack iptable_mangle iptable_filter ip_tables crc_ccitt compat nf_log_ipv6 nf_log_common ip6table_mangle ip6table_filter ip6_tables ip6t_REJECT x_tables nf_reject_ipv6 usb_storage xhci_plat_hcd xhci_pci xhci_hcd dwc3 usbcore usb_common [ 1110.932190] Process swapper/3 (pid: 0, stack limit = 0xffff0000090c8000) [ 1110.938884] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.14.162 #0 [ 1110.944965] Hardware name: LS1043A RGW Board (DT) [ 1110.949658] task: ffff8000787a81c0 task.stack: ffff0000090c8000 [ 1110.955568] PC is at 0x0 [ 1110.958097] LR is at call_timer_fn.isra.27+0x24/0x78 [ 1110.963055] pc : [<0000000000000000>] lr : [<ffff0000080ff29c>] pstate: 00400145 [ 1110.970440] sp : ffff00000801be10 [ 1110.973744] x29: ffff00000801be10 x28: ffff000008bf7018 [ 1110.979047] x27: ffff000008bf87c8 x26: ffff000008c160c0 [ 1110.984352] x25: 0000000000000000 x24: 0000000000000000 [ 1110.989657] x23: dead000000000200 x22: 0000000000000000 [ 1110.994959] x21: 0000000000000000 x20: 0000000000000101 [ 1111.000262] x19: ffff8000787a81c0 x18: 0000000000000000 [ 1111.005565] x17: ffff0000089167b0 x16: 0000000000000058 [ 1111.010868] x15: ffff0000089167b0 x14: 0000000000000000 [ 1111.016172] x13: ffff000008916788 x12: 0000000000000040 [ 1111.021475] x11: ffff80007fda9af0 x10: 0000000000000001 [ 1111.026777] x9 : ffff00000801bea0 x8 : 0000000000000004 [ 1111.032080] x7 : 0000000000000000 x6 : ffff80007fda9aa8 [ 1111.037383] x5 : ffff00000801bea0 x4 : 0000000000000010 [ 1111.042685] x3 : ffff00000801be98 x2 : 0000000000000614 [ 1111.047988] x1 : 0000000000000000 x0 : 0000000000000000 [ 1111.053290] Call trace: [ 1111.055728] Exception stack(0xffff00000801bcd0 to 0xffff00000801be10) [ 1111.062158] bcc0: 0000000000000000 0000000000000000 [ 1111.069978] bce0: 0000000000000614 ffff00000801be98 0000000000000010 ffff00000801bea0 [ 1111.077798] bd00: ffff80007fda9aa8 0000000000000000 0000000000000004 ffff00000801bea0 [ 1111.085618] bd20: 0000000000000001 ffff80007fda9af0 0000000000000040 ffff000008916788 [ 1111.093437] bd40: 0000000000000000 ffff0000089167b0 0000000000000058 ffff0000089167b0 [ 1111.101256] bd60: 0000000000000000 ffff8000787a81c0 0000000000000101 0000000000000000 [ 1111.109075] bd80: 0000000000000000 dead000000000200 0000000000000000 0000000000000000 [ 1111.116895] bda0: ffff000008c160c0 ffff000008bf87c8 ffff000008bf7018 ffff00000801be10 [ 1111.124715] bdc0: ffff0000080ff29c ffff00000801be10 0000000000000000 0000000000400145 [ 1111.132534] bde0: ffff8000787a81c0 ffff00000801bde8 0000ffffffffffff 000001029eb19be8 [ 1111.140353] be00: ffff00000801be10 0000000000000000 [ 1111.145220] [< (null)>] (null) [ 1111.149917] [<ffff0000080ff77c>] run_timer_softirq+0x184/0x398 [ 1111.155741] [<ffff000008081938>] __do_softirq+0x100/0x1fc [ 1111.161130] [<ffff0000080a2e28>] irq_exit+0x80/0xd8 [ 1111.166002] [<ffff0000080ea708>] __handle_domain_irq+0x88/0xb0 [ 1111.171825] [<ffff000008081678>] gic_handle_irq+0x68/0xb0 [ 1111.177213] Exception stack(0xffff0000090cbe30 to 0xffff0000090cbf70) [ 1111.183642] be20: 0000000000000020 0000000000000000 [ 1111.191461] be40: 0000000000000001 0000000000000000 00008000771af000 0000000000000000 [ 1111.199281] be60: ffff000008c95180 0000000000000000 ffff000008c19360 ffff0000090cbef0 [ 1111.207101] be80: 0000000000000810 0000000000000400 0000000000000098 ffff000000000000 [ 1111.214920] bea0: 0000000000000001 ffff0000089167b0 0000000000000000 ffff0000089167b0 [ 1111.222740] bec0: 0000000000000000 ffff000008c198e8 ffff000008bf7018 ffff000008c19000 [ 1111.230559] bee0: 0000000000000000 0000000000000000 ffff8000787a81c0 ffff000008018000 [ 1111.238380] bf00: ffff00000801c000 ffff00000913ba34 ffff8000787a81c0 ffff0000090cbf70 [ 1111.246199] bf20: ffff0000080857cc ffff0000090cbf70 ffff0000080857d0 0000000000400145 [ 1111.254020] bf40: ffff000008018000 ffff00000801c000 ffffffffffffffff ffff0000080fa574 [ 1111.261838] bf60: ffff0000090cbf70 ffff0000080857d0 [ 1111.266706] [<ffff0000080832e8>] el1_irq+0xe8/0x18c [ 1111.271576] [<ffff0000080857d0>] arch_cpu_idle+0x10/0x18 [ 1111.276880] [<ffff0000080d7de4>] do_idle+0xec/0x1b8 [ 1111.281748] [<ffff0000080d8020>] cpu_startup_entry+0x20/0x28 [ 1111.287399] [<ffff00000808f81c>] secondary_start_kernel+0x104/0x110 [ 1111.293662] Code: bad PC value [ 1111.296710] ---[ end trace 555b6ca4363c3edd ]--- [ 1111.301318] Kernel panic - not syncing: Fatal exception in interrupt [ 1111.307661] SMP: stopping secondary CPUs [ 1111.311574] Kernel Offset: disabled [ 1111.315053] CPU features: 0x0002000 [ 1111.318530] Memory Limit: none [ 1111.321575] Rebooting in 3 seconds.. With some added debug output / delays we were able to push the crash from the timer callback runner into the callback function and by that shedding some light on which object holding the timer gets corrupted: [ 401.720899] Unable to handle kernel read from unreadable memory at virtual address 00000868 [...] [ 402.335836] [<ffff0000088fafa4>] _raw_spin_lock_bh+0x14/0x48 [ 402.341548] [<ffff000000dbe684>] mesh_path_timer+0x10c/0x248 [mac80211] [ 402.348154] [<ffff0000080ff29c>] call_timer_fn.isra.27+0x24/0x78 [ 402.354150] [<ffff0000080ff77c>] run_timer_softirq+0x184/0x398 [ 402.359974] [<ffff000008081938>] __do_softirq+0x100/0x1fc [ 402.365362] [<ffff0000080a2e28>] irq_exit+0x80/0xd8 [ 402.370231] [<ffff0000080ea708>] __handle_domain_irq+0x88/0xb0 [ 402.376053] [<ffff000008081678>] gic_handle_irq+0x68/0xb0 The issue happens due to the following sequence of events: 1) mesh_path_start_discovery(): -> spin_unlock_bh(&mpath->state_lock) before mesh_path_sel_frame_tx() 2) mesh_path_free_rcu() -> del_timer_sync(&mpath->timer) [...] -> kfree_rcu(mpath) 3) mesh_path_start_discovery(): -> mod_timer(&mpath->timer, ...) [...] -> rcu_read_unlock() 4) mesh_path_free_rcu()'s kfree_rcu(): -> kfree(mpath) 5) mesh_path_timer() starts after timeout, using freed mpath object So a use-after-free issue due to a timer re-arming bug caused by an early spin-unlocking. This patch fixes this issue by re-checking if mpath is about to be free'd and if so bails out of re-arming the timer. Cc: stable@vger.kernel.org Fixes: 050ac52cbe1f ("mac80211: code for on-demand Hybrid Wireless Mesh Protocol") Cc: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Linus Lüssing <ll@simonwunderlich.de> Link: https://lore.kernel.org/r/20200522170413.14973-1-linus.luessing@c0d3.blue Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-05-22 17:04:13 +00:00
spin_unlock_bh(&mpath->state_lock);
enddiscovery:
rcu_read_unlock();
kfree(preq_node);
}
/**
* mesh_nexthop_resolve - lookup next hop; conditionally start path discovery
*
* @skb: 802.11 frame to be sent
* @sdata: network subif the frame will be sent through
*
* Lookup next hop for given skb and start path discovery if no
* forwarding information is found.
*
* Returns: 0 if the next hop was found and -ENOENT if the frame was queued.
* skb is freed here if no mpath could be allocated.
*/
int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
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;
mac80211: mesh power save basics Add routines to - maintain a PS mode for each peer and a non-peer PS mode - indicate own PS mode in transmitted frames - track neighbor STAs power modes - buffer frames when neighbors are in PS mode - add TIM and Awake Window IE to beacons - release frames in Mesh Peer Service Periods Add local_pm to sta_info to represent the link-specific power mode at this station towards the remote station. When a peer link is established, use the default power mode stored in mesh config. Update the PS status if the peering status of a neighbor changes. Maintain a mesh power mode for non-peer mesh STAs. Set the non-peer power mode to active mode during peering. Authenticated mesh peering is currently not working when either node is configured to be in power save mode. Indicate the current power mode in transmitted frames. Use QoS Nulls to indicate mesh power mode transitions. For performance reasons, calls to the function setting the frame flags are placed in HWMP routing routines, as there the STA pointer is already available. Add peer_pm to sta_info to represent the peer's link-specific power mode towards the local station. Add nonpeer_pm to represent the peer's power mode towards all non-peer stations. Track power modes based on received frames. Add the ps_data structure to ieee80211_if_mesh (for TIM map, PS neighbor counter and group-addressed frame buffer). Set WLAN_STA_PS flag for STA in PS mode to use the unicast frame buffering routines in the tx path. Update num_sta_ps to buffer and release group-addressed frames after DTIM beacons. Announce the awake window duration in beacons if in light or deep sleep mode towards any peer or non-peer. Create a TIM IE similarly to AP mode and add it to mesh beacons. Parse received Awake Window IEs and check TIM IEs for buffered frames. Release frames towards peers in mesh Peer Service Periods. Use the corresponding trigger frames and monitor the MPSP status. Append a QoS Null as trigger frame if neccessary to properly end the MPSP. Currently, in HT channels MPSPs behave imperfectly and show large delay spikes and frame losses. Signed-off-by: Marco Porsch <marco@cozybit.com> Signed-off-by: Ivan Bezyazychnyy <ivan.bezyazychnyy@gmail.com> Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-30 17:14:08 +00:00
/* Nulls are only sent to peers for PS and should be pre-addressed */
if (ieee80211_is_qos_nullfunc(hdr->frame_control))
return 0;
/* Allow injected packets to bypass mesh routing */
if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
return 0;
if (!mesh_nexthop_lookup(sdata, skb))
return 0;
/* no nexthop found, start resolving */
mpath = mesh_path_lookup(sdata, target_addr);
if (!mpath) {
mpath = mesh_path_add(sdata, target_addr);
if (IS_ERR(mpath)) {
mesh_path_discard_frame(sdata, skb);
return PTR_ERR(mpath);
}
}
if (!(mpath->flags & MESH_PATH_RESOLVING) &&
mesh_path_sel_is_hwmp(sdata))
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->control.flags |= IEEE80211_TX_INTCFL_NEED_TXPROCESSING;
ieee80211_set_qos_hdr(sdata, skb);
skb_queue_tail(&mpath->frame_queue, skb);
if (skb_to_free)
mesh_path_discard_frame(sdata, skb_to_free);
return -ENOENT;
}
cfg80211/mac80211: add mesh_param "mesh_nolearn" to skip path discovery Currently, before being able to forward a packet between two 802.11s nodes, both a PLINK handshake is performed upon receiving a beacon and then later a PREQ/PREP exchange for path discovery is performed on demand upon receiving a data frame to forward. When running a mesh protocol on top of an 802.11s interface, like batman-adv, we do not need the multi-hop mesh routing capabilities of 802.11s and usually set mesh_fwding=0. However, even with mesh_fwding=0 the PREQ/PREP path discovery is still performed on demand. Even though in this scenario the next hop PREQ/PREP will determine is always the direct 11s neighbor node. The new mesh_nolearn parameter allows to skip the PREQ/PREP exchange in this scenario, leading to a reduced delay, reduced packet buffering and simplifies HWMP in general. mesh_nolearn is still rather conservative in that if the packet destination is not a direct 11s neighbor, it will fall back to PREQ/PREP path discovery. For normal, multi-hop 802.11s mesh routing it is usually not advisable to enable mesh_nolearn as a transmission to a direct but distant neighbor might be worse than reaching that same node via a more robust / higher throughput etc. multi-hop path. Cc: Sven Eckelmann <sven@narfation.org> Cc: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Linus Lüssing <ll@simonwunderlich.de> Link: https://lore.kernel.org/r/20200617073034.26149-1-linus.luessing@c0d3.blue [fix nl80211 policy to range 0/1 only] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-06-17 07:30:33 +00:00
/**
* mesh_nexthop_lookup_nolearn - try to set next hop without path discovery
* @skb: 802.11 frame to be sent
* @sdata: network subif the frame will be sent through
*
* Check if the meshDA (addr3) of a unicast frame is a direct neighbor.
* And if so, set the RA (addr1) to it to transmit to this node directly,
* avoiding PREQ/PREP path discovery.
*
* Returns: 0 if the next hop was found and -ENOENT otherwise.
*/
static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct sta_info *sta;
if (is_multicast_ether_addr(hdr->addr1))
return -ENOENT;
rcu_read_lock();
sta = sta_info_get(sdata, hdr->addr3);
if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
rcu_read_unlock();
return -ENOENT;
}
rcu_read_unlock();
memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN);
return 0;
}
/**
* 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 ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
cfg80211/mac80211: add mesh_param "mesh_nolearn" to skip path discovery Currently, before being able to forward a packet between two 802.11s nodes, both a PLINK handshake is performed upon receiving a beacon and then later a PREQ/PREP exchange for path discovery is performed on demand upon receiving a data frame to forward. When running a mesh protocol on top of an 802.11s interface, like batman-adv, we do not need the multi-hop mesh routing capabilities of 802.11s and usually set mesh_fwding=0. However, even with mesh_fwding=0 the PREQ/PREP path discovery is still performed on demand. Even though in this scenario the next hop PREQ/PREP will determine is always the direct 11s neighbor node. The new mesh_nolearn parameter allows to skip the PREQ/PREP exchange in this scenario, leading to a reduced delay, reduced packet buffering and simplifies HWMP in general. mesh_nolearn is still rather conservative in that if the packet destination is not a direct 11s neighbor, it will fall back to PREQ/PREP path discovery. For normal, multi-hop 802.11s mesh routing it is usually not advisable to enable mesh_nolearn as a transmission to a direct but distant neighbor might be worse than reaching that same node via a more robust / higher throughput etc. multi-hop path. Cc: Sven Eckelmann <sven@narfation.org> Cc: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Linus Lüssing <ll@simonwunderlich.de> Link: https://lore.kernel.org/r/20200617073034.26149-1-linus.luessing@c0d3.blue [fix nl80211 policy to range 0/1 only] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-06-17 07:30:33 +00:00
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
struct sta_info *next_hop;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
u8 *target_addr = hdr->addr3;
cfg80211/mac80211: add mesh_param "mesh_nolearn" to skip path discovery Currently, before being able to forward a packet between two 802.11s nodes, both a PLINK handshake is performed upon receiving a beacon and then later a PREQ/PREP exchange for path discovery is performed on demand upon receiving a data frame to forward. When running a mesh protocol on top of an 802.11s interface, like batman-adv, we do not need the multi-hop mesh routing capabilities of 802.11s and usually set mesh_fwding=0. However, even with mesh_fwding=0 the PREQ/PREP path discovery is still performed on demand. Even though in this scenario the next hop PREQ/PREP will determine is always the direct 11s neighbor node. The new mesh_nolearn parameter allows to skip the PREQ/PREP exchange in this scenario, leading to a reduced delay, reduced packet buffering and simplifies HWMP in general. mesh_nolearn is still rather conservative in that if the packet destination is not a direct 11s neighbor, it will fall back to PREQ/PREP path discovery. For normal, multi-hop 802.11s mesh routing it is usually not advisable to enable mesh_nolearn as a transmission to a direct but distant neighbor might be worse than reaching that same node via a more robust / higher throughput etc. multi-hop path. Cc: Sven Eckelmann <sven@narfation.org> Cc: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Linus Lüssing <ll@simonwunderlich.de> Link: https://lore.kernel.org/r/20200617073034.26149-1-linus.luessing@c0d3.blue [fix nl80211 policy to range 0/1 only] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-06-17 07:30:33 +00:00
if (ifmsh->mshcfg.dot11MeshNolearn &&
!mesh_nexthop_lookup_nolearn(sdata, skb))
return 0;
mpath = mesh_path_lookup(sdata, target_addr);
if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE))
return -ENOENT;
if (time_after(jiffies,
mpath->exp_time -
msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) &&
ether_addr_equal(sdata->vif.addr, hdr->addr4) &&
!(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);
mac80211: mesh power save basics Add routines to - maintain a PS mode for each peer and a non-peer PS mode - indicate own PS mode in transmitted frames - track neighbor STAs power modes - buffer frames when neighbors are in PS mode - add TIM and Awake Window IE to beacons - release frames in Mesh Peer Service Periods Add local_pm to sta_info to represent the link-specific power mode at this station towards the remote station. When a peer link is established, use the default power mode stored in mesh config. Update the PS status if the peering status of a neighbor changes. Maintain a mesh power mode for non-peer mesh STAs. Set the non-peer power mode to active mode during peering. Authenticated mesh peering is currently not working when either node is configured to be in power save mode. Indicate the current power mode in transmitted frames. Use QoS Nulls to indicate mesh power mode transitions. For performance reasons, calls to the function setting the frame flags are placed in HWMP routing routines, as there the STA pointer is already available. Add peer_pm to sta_info to represent the peer's link-specific power mode towards the local station. Add nonpeer_pm to represent the peer's power mode towards all non-peer stations. Track power modes based on received frames. Add the ps_data structure to ieee80211_if_mesh (for TIM map, PS neighbor counter and group-addressed frame buffer). Set WLAN_STA_PS flag for STA in PS mode to use the unicast frame buffering routines in the tx path. Update num_sta_ps to buffer and release group-addressed frames after DTIM beacons. Announce the awake window duration in beacons if in light or deep sleep mode towards any peer or non-peer. Create a TIM IE similarly to AP mode and add it to mesh beacons. Parse received Awake Window IEs and check TIM IEs for buffered frames. Release frames towards peers in mesh Peer Service Periods. Use the corresponding trigger frames and monitor the MPSP status. Append a QoS Null as trigger frame if neccessary to properly end the MPSP. Currently, in HT channels MPSPs behave imperfectly and show large delay spikes and frame losses. Signed-off-by: Marco Porsch <marco@cozybit.com> Signed-off-by: Ivan Bezyazychnyy <ivan.bezyazychnyy@gmail.com> Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-30 17:14:08 +00:00
ieee80211_mps_set_frame_flags(sdata, next_hop, hdr);
return 0;
}
return -ENOENT;
}
void mesh_path_timer(struct timer_list *t)
{
struct mesh_path *mpath = from_timer(mpath, t, timer);
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 &= ~(MESH_PATH_RESOLVING |
MESH_PATH_RESOLVED |
MESH_PATH_REQ_QUEUED);
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;
fallthrough;
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;
}
}