linux/net/wireless/mesh.c
Johannes Berg 5fe231e873 cfg80211: vastly simplify locking
Virtually all code paths in cfg80211 already (need to) hold
the RTNL. As such, there's little point in having another
four mutexes for various parts of the code, they just cause
lock ordering issues (and much of the time, the RTNL and a
few of the others need thus be held.)

Simplify all this by getting rid of the extra four mutexes
and just use the RTNL throughout. Only a few code changes
were needed to do this and we can get rid of a work struct
for bonus points.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-05-25 00:02:15 +02:00

274 lines
7.1 KiB
C

#include <linux/ieee80211.h>
#include <linux/export.h>
#include <net/cfg80211.h>
#include "nl80211.h"
#include "core.h"
#include "rdev-ops.h"
/* Default values, timeouts in ms */
#define MESH_TTL 31
#define MESH_DEFAULT_ELEMENT_TTL 31
#define MESH_MAX_RETR 3
#define MESH_RET_T 100
#define MESH_CONF_T 100
#define MESH_HOLD_T 100
#define MESH_PATH_TIMEOUT 5000
#define MESH_RANN_INTERVAL 5000
#define MESH_PATH_TO_ROOT_TIMEOUT 6000
#define MESH_ROOT_INTERVAL 5000
#define MESH_ROOT_CONFIRMATION_INTERVAL 2000
/*
* Minimum interval between two consecutive PREQs originated by the same
* interface
*/
#define MESH_PREQ_MIN_INT 10
#define MESH_PERR_MIN_INT 100
#define MESH_DIAM_TRAVERSAL_TIME 50
#define MESH_RSSI_THRESHOLD 0
/*
* A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
* before timing out. This way it will remain ACTIVE and no data frames
* will be unnecessarily held in the pending queue.
*/
#define MESH_PATH_REFRESH_TIME 1000
#define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
/* Default maximum number of established plinks per interface */
#define MESH_MAX_ESTAB_PLINKS 32
#define MESH_MAX_PREQ_RETRIES 4
#define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
#define MESH_DEFAULT_BEACON_INTERVAL 1000 /* in 1024 us units (=TUs) */
#define MESH_DEFAULT_DTIM_PERIOD 2
#define MESH_DEFAULT_AWAKE_WINDOW 10 /* in 1024 us units (=TUs) */
const struct mesh_config default_mesh_config = {
.dot11MeshRetryTimeout = MESH_RET_T,
.dot11MeshConfirmTimeout = MESH_CONF_T,
.dot11MeshHoldingTimeout = MESH_HOLD_T,
.dot11MeshMaxRetries = MESH_MAX_RETR,
.dot11MeshTTL = MESH_TTL,
.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
.auto_open_plinks = true,
.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
.path_refresh_time = MESH_PATH_REFRESH_TIME,
.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
.dot11MeshGateAnnouncementProtocol = false,
.dot11MeshForwarding = true,
.rssi_threshold = MESH_RSSI_THRESHOLD,
.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
.power_mode = NL80211_MESH_POWER_ACTIVE,
.dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
};
const struct mesh_setup default_mesh_setup = {
/* cfg80211_join_mesh() will pick a channel if needed */
.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
.auth_id = 0, /* open */
.ie = NULL,
.ie_len = 0,
.is_secure = false,
.user_mpm = false,
.beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
.dtim_period = MESH_DEFAULT_DTIM_PERIOD,
};
int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
struct net_device *dev,
struct mesh_setup *setup,
const struct mesh_config *conf)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
int err;
BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
ASSERT_WDEV_LOCK(wdev);
if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
return -EOPNOTSUPP;
if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
setup->is_secure)
return -EOPNOTSUPP;
if (wdev->mesh_id_len)
return -EALREADY;
if (!setup->mesh_id_len)
return -EINVAL;
if (!rdev->ops->join_mesh)
return -EOPNOTSUPP;
if (!setup->chandef.chan) {
/* if no channel explicitly given, use preset channel */
setup->chandef = wdev->preset_chandef;
}
if (!setup->chandef.chan) {
/* if we don't have that either, use the first usable channel */
enum ieee80211_band band;
for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
struct ieee80211_supported_band *sband;
struct ieee80211_channel *chan;
int i;
sband = rdev->wiphy.bands[band];
if (!sband)
continue;
for (i = 0; i < sband->n_channels; i++) {
chan = &sband->channels[i];
if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
IEEE80211_CHAN_PASSIVE_SCAN |
IEEE80211_CHAN_DISABLED |
IEEE80211_CHAN_RADAR))
continue;
setup->chandef.chan = chan;
break;
}
if (setup->chandef.chan)
break;
}
/* no usable channel ... */
if (!setup->chandef.chan)
return -EINVAL;
setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
}
if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef))
return -EINVAL;
err = cfg80211_can_use_chan(rdev, wdev, setup->chandef.chan,
CHAN_MODE_SHARED);
if (err)
return err;
err = rdev_join_mesh(rdev, dev, conf, setup);
if (!err) {
memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
wdev->mesh_id_len = setup->mesh_id_len;
wdev->channel = setup->chandef.chan;
}
return err;
}
int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
struct net_device *dev,
struct mesh_setup *setup,
const struct mesh_config *conf)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
int err;
wdev_lock(wdev);
err = __cfg80211_join_mesh(rdev, dev, setup, conf);
wdev_unlock(wdev);
return err;
}
int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
struct wireless_dev *wdev,
struct cfg80211_chan_def *chandef)
{
int err;
/*
* Workaround for libertas (only!), it puts the interface
* into mesh mode but doesn't implement join_mesh. Instead,
* it is configured via sysfs and then joins the mesh when
* you set the channel. Note that the libertas mesh isn't
* compatible with 802.11 mesh.
*/
if (rdev->ops->libertas_set_mesh_channel) {
if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
return -EINVAL;
if (!netif_running(wdev->netdev))
return -ENETDOWN;
err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
CHAN_MODE_SHARED);
if (err)
return err;
err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
chandef->chan);
if (!err)
wdev->channel = chandef->chan;
return err;
}
if (wdev->mesh_id_len)
return -EBUSY;
wdev->preset_chandef = *chandef;
return 0;
}
static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
struct net_device *dev)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
int err;
ASSERT_WDEV_LOCK(wdev);
if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
return -EOPNOTSUPP;
if (!rdev->ops->leave_mesh)
return -EOPNOTSUPP;
if (!wdev->mesh_id_len)
return -ENOTCONN;
err = rdev_leave_mesh(rdev, dev);
if (!err) {
wdev->mesh_id_len = 0;
wdev->channel = NULL;
}
return err;
}
int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
struct net_device *dev)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
int err;
wdev_lock(wdev);
err = __cfg80211_leave_mesh(rdev, dev);
wdev_unlock(wdev);
return err;
}