2014-09-12 06:59:21

by Henning Rogge

[permalink] [raw]
Subject: [PATCH v4 0/2] cfg80211: Add export of mesh proxy path table

The following patch series adds and implements two new cfg80211_ops that
allow to query the content of the mac80211s mesh proxy path table via
netlink.

v2 changes:
* split the original patch into separate cfg80211 and mac80211 part

v3 change:
* change of commit messages, added signoff

v4 change:
* another change of commit messages

Henning Rogge (2):
cfg80211: add ops to query mesh proxy path table
mac80211: implement cfg80211_ops to query mesh proxy path table

include/net/cfg80211.h | 7 ++++
include/uapi/linux/nl80211.h | 6 +++
net/mac80211/cfg.c | 53 ++++++++++++++++++++++++
net/mac80211/mesh.h | 3 ++
net/mac80211/mesh_pathtbl.c | 31 ++++++++++++++
net/wireless/nl80211.c | 99 ++++++++++++++++++++++++++++++++++++++++++++
net/wireless/rdev-ops.h | 27 +++++++++++-
net/wireless/trace.h | 45 ++++++++++++++++++++
8 files changed, 270 insertions(+), 1 deletion(-)

--
1.9.1



2014-09-12 06:59:24

by Henning Rogge

[permalink] [raw]
Subject: [PATCH v4 2/2] mac80211: implement cfg80211_ops to query mesh proxy path table

Implement get_mpp and dump_mpp cfg80211_ops to export the content of the
802.11s mesh proxy path table to userspace.

Signed-off-by: Henning Rogge <[email protected]>
---
net/mac80211/cfg.c | 53 +++++++++++++++++++++++++++++++++++++++++++++
net/mac80211/mesh.h | 3 +++
net/mac80211/mesh_pathtbl.c | 31 ++++++++++++++++++++++++++
3 files changed, 87 insertions(+)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 4d8989b..2538a2f 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1504,6 +1504,57 @@ static int ieee80211_dump_mpath(struct wiphy *wiphy, struct net_device *dev,
return 0;
}

+static void mpp_set_pinfo(struct mesh_path *mpath, u8 *mpp,
+ struct mpath_info *pinfo)
+{
+ memset(pinfo, 0, sizeof(*pinfo));
+ memcpy(mpp, mpath->mpp, ETH_ALEN);
+
+ pinfo->generation = mpp_paths_generation;
+}
+
+static int ieee80211_get_mpp(struct wiphy *wiphy, struct net_device *dev,
+ u8 *dst, u8 *mpp, struct mpath_info *pinfo)
+
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct mesh_path *mpath;
+
+ sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+ rcu_read_lock();
+ mpath = mpp_path_lookup(sdata, dst);
+ if (!mpath) {
+ rcu_read_unlock();
+ return -ENOENT;
+ }
+ memcpy(dst, mpath->dst, ETH_ALEN);
+ mpp_set_pinfo(mpath, mpp, pinfo);
+ rcu_read_unlock();
+ return 0;
+}
+
+static int ieee80211_dump_mpp(struct wiphy *wiphy, struct net_device *dev,
+ int idx, u8 *dst, u8 *mpp,
+ struct mpath_info *pinfo)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct mesh_path *mpath;
+
+ sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+ rcu_read_lock();
+ mpath = mpp_path_lookup_by_idx(sdata, idx);
+ if (!mpath) {
+ rcu_read_unlock();
+ return -ENOENT;
+ }
+ memcpy(dst, mpath->dst, ETH_ALEN);
+ mpp_set_pinfo(mpath, mpp, pinfo);
+ rcu_read_unlock();
+ return 0;
+}
+
static int ieee80211_get_mesh_config(struct wiphy *wiphy,
struct net_device *dev,
struct mesh_config *conf)
@@ -3500,6 +3551,8 @@ const struct cfg80211_ops mac80211_config_ops = {
.change_mpath = ieee80211_change_mpath,
.get_mpath = ieee80211_get_mpath,
.dump_mpath = ieee80211_dump_mpath,
+ .get_mpp = ieee80211_get_mpp,
+ .dump_mpp = ieee80211_dump_mpp,
.update_mesh_config = ieee80211_update_mesh_config,
.get_mesh_config = ieee80211_get_mesh_config,
.join_mesh = ieee80211_join_mesh,
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index f39a19f..50c8473 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -270,6 +270,8 @@ int mpp_path_add(struct ieee80211_sub_if_data *sdata,
const u8 *dst, const u8 *mpp);
struct mesh_path *
mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);
+struct mesh_path *
+mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);
void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
@@ -317,6 +319,7 @@ void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);

bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
extern int mesh_paths_generation;
+extern int mpp_paths_generation;

#ifdef CONFIG_MAC80211_MESH
static inline
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index a6699dc..b890e22 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -44,6 +44,7 @@ static struct mesh_table __rcu *mesh_paths;
static struct mesh_table __rcu *mpp_paths; /* Store paths for MPP&MAP */

int mesh_paths_generation;
+int mpp_paths_generation;

/* This lock will have the grow table function as writer and add / delete nodes
* as readers. RCU provides sufficient protection only when reading the table
@@ -410,6 +411,33 @@ mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
}

/**
+ * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
+ * @idx: index
+ * @sdata: local subif, or NULL for all entries
+ *
+ * Returns: pointer to the proxy path structure, or NULL if not found.
+ *
+ * Locking: must be called within a read rcu section.
+ */
+struct mesh_path *
+mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
+{
+ struct mesh_table *tbl = rcu_dereference(mpp_paths);
+ struct mpath_node *node;
+ int i;
+ int j = 0;
+
+ for_each_mesh_entry(tbl, node, i) {
+ if (sdata && node->mpath->sdata != sdata)
+ continue;
+ if (j++ == idx)
+ return node->mpath;
+ }
+
+ return NULL;
+}
+
+/**
* mesh_path_add_gate - add the given mpath to a mesh gate to our path table
* @mpath: gate path to add to table
*/
@@ -691,6 +719,9 @@ int mpp_path_add(struct ieee80211_sub_if_data *sdata,

spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&pathtbl_resize_lock);
+
+ mpp_paths_generation++;
+
if (grow) {
set_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags);
ieee80211_queue_work(&local->hw, &sdata->work);
--
1.9.1


2014-09-12 06:59:22

by Henning Rogge

[permalink] [raw]
Subject: [PATCH v4 1/2] cfg80211: add ops to query mesh proxy path table

Add two new cfg80211 operations for querying a table with proxied mesh
paths.

Signed-off-by: Henning Rogge <[email protected]>
---
include/net/cfg80211.h | 7 ++++
include/uapi/linux/nl80211.h | 6 +++
net/wireless/nl80211.c | 99 ++++++++++++++++++++++++++++++++++++++++++++
net/wireless/rdev-ops.h | 27 +++++++++++-
net/wireless/trace.h | 45 ++++++++++++++++++++
5 files changed, 183 insertions(+), 1 deletion(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index ab21299..1d1467f 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2141,6 +2141,8 @@ struct cfg80211_qos_map {
* @change_mpath: change a given mesh path
* @get_mpath: get a mesh path for the given parameters
* @dump_mpath: dump mesh path callback -- resume dump at index @idx
+ * @get_mpp: get a mesh proxy path for the given parameters
+ * @dump_mpp: dump mesh proxy path callback -- resume dump at index @idx
* @join_mesh: join the mesh network with the specified parameters
* (invoked with the wireless_dev mutex held)
* @leave_mesh: leave the current mesh network
@@ -2380,6 +2382,11 @@ struct cfg80211_ops {
int (*dump_mpath)(struct wiphy *wiphy, struct net_device *dev,
int idx, u8 *dst, u8 *next_hop,
struct mpath_info *pinfo);
+ int (*get_mpp)(struct wiphy *wiphy, struct net_device *dev,
+ u8 *dst, u8 *mpp, struct mpath_info *pinfo);
+ int (*dump_mpp)(struct wiphy *wiphy, struct net_device *dev,
+ int idx, u8 *dst, u8 *mpp,
+ struct mpath_info *pinfo);
int (*get_mesh_config)(struct wiphy *wiphy,
struct net_device *dev,
struct mesh_config *conf);
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index d097568..b5c5052 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -722,6 +722,10 @@
* QoS mapping is relevant for IP packets, it is only valid during an
* association. This is cleared on disassociation and AP restart.
*
+ * @NL80211_CMD_GET_MPP: Get mesh path attributes for mesh proxy path to
+ * destination %NL80211_ATTR_MAC on the interface identified by
+ * %NL80211_ATTR_IFINDEX.
+ *
* @NL80211_CMD_MAX: highest used command number
* @__NL80211_CMD_AFTER_LAST: internal use
*/
@@ -893,6 +897,8 @@ enum nl80211_commands {

NL80211_CMD_SET_QOS_MAP,

+ NL80211_CMD_GET_MPP,
+
/* add new commands above here */

/* used to define NL80211_CMD_MAX below */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 3011401..cbaf722 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4581,6 +4581,96 @@ static int nl80211_del_mpath(struct sk_buff *skb, struct genl_info *info)
return rdev_del_mpath(rdev, dev, dst);
}

+static int nl80211_get_mpp(struct sk_buff *skb, struct genl_info *info)
+{
+ struct cfg80211_registered_device *rdev = info->user_ptr[0];
+ int err;
+ struct net_device *dev = info->user_ptr[1];
+ struct mpath_info pinfo;
+ struct sk_buff *msg;
+ u8 *dst = NULL;
+ u8 mpp[ETH_ALEN];
+
+ memset(&pinfo, 0, sizeof(pinfo));
+
+ if (!info->attrs[NL80211_ATTR_MAC])
+ return -EINVAL;
+
+ dst = nla_data(info->attrs[NL80211_ATTR_MAC]);
+
+ if (!rdev->ops->get_mpp)
+ return -EOPNOTSUPP;
+
+ if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
+ return -EOPNOTSUPP;
+
+ err = rdev_get_mpp(rdev, dev, dst, mpp, &pinfo);
+ if (err)
+ return err;
+
+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ if (nl80211_send_mpath(msg, info->snd_portid, info->snd_seq, 0,
+ dev, dst, mpp, &pinfo) < 0) {
+ nlmsg_free(msg);
+ return -ENOBUFS;
+ }
+
+ return genlmsg_reply(msg, info);
+}
+
+static int nl80211_dump_mpp(struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ struct mpath_info pinfo;
+ struct cfg80211_registered_device *rdev;
+ struct wireless_dev *wdev;
+ u8 dst[ETH_ALEN];
+ u8 mpp[ETH_ALEN];
+ int path_idx = cb->args[2];
+ int err;
+
+ err = nl80211_prepare_wdev_dump(skb, cb, &rdev, &wdev);
+ if (err)
+ return err;
+
+ if (!rdev->ops->dump_mpp) {
+ err = -EOPNOTSUPP;
+ goto out_err;
+ }
+
+ if (wdev->iftype != NL80211_IFTYPE_MESH_POINT) {
+ err = -EOPNOTSUPP;
+ goto out_err;
+ }
+
+ while (1) {
+ err = rdev_dump_mpp(rdev, wdev->netdev, path_idx, dst,
+ mpp, &pinfo);
+ if (err == -ENOENT)
+ break;
+ if (err)
+ goto out_err;
+
+ if (nl80211_send_mpath(skb, NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI,
+ wdev->netdev, dst, mpp,
+ &pinfo) < 0)
+ goto out;
+
+ path_idx++;
+ }
+
+ out:
+ cb->args[2] = path_idx;
+ err = skb->len;
+ out_err:
+ nl80211_finish_wdev_dump(rdev);
+ return err;
+}
+
static int nl80211_set_bss(struct sk_buff *skb, struct genl_info *info)
{
struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -9611,6 +9701,15 @@ static const struct genl_ops nl80211_ops[] = {
NL80211_FLAG_NEED_RTNL,
},
{
+ .cmd = NL80211_CMD_GET_MPP,
+ .doit = nl80211_get_mpp,
+ .dumpit = nl80211_dump_mpp,
+ .policy = nl80211_policy,
+ .flags = GENL_ADMIN_PERM,
+ .internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
+ NL80211_FLAG_NEED_RTNL,
+ },
+ {
.cmd = NL80211_CMD_SET_MPATH,
.doit = nl80211_set_mpath,
.policy = nl80211_policy,
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index 56c2240..e5560d5 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -263,6 +263,18 @@ static inline int rdev_get_mpath(struct cfg80211_registered_device *rdev,

}

+static inline int rdev_get_mpp(struct cfg80211_registered_device *rdev,
+ struct net_device *dev, u8 *dst, u8 *mpp,
+ struct mpath_info *pinfo)
+{
+ int ret;
+
+ trace_rdev_get_mpp(&rdev->wiphy, dev, dst, mpp);
+ ret = rdev->ops->get_mpp(&rdev->wiphy, dev, dst, mpp, pinfo);
+ trace_rdev_return_int_mpath_info(&rdev->wiphy, ret, pinfo);
+ return ret;
+}
+
static inline int rdev_dump_mpath(struct cfg80211_registered_device *rdev,
struct net_device *dev, int idx, u8 *dst,
u8 *next_hop, struct mpath_info *pinfo)
@@ -271,7 +283,20 @@ static inline int rdev_dump_mpath(struct cfg80211_registered_device *rdev,
int ret;
trace_rdev_dump_mpath(&rdev->wiphy, dev, idx, dst, next_hop);
ret = rdev->ops->dump_mpath(&rdev->wiphy, dev, idx, dst, next_hop,
- pinfo);
+ pinfo);
+ trace_rdev_return_int_mpath_info(&rdev->wiphy, ret, pinfo);
+ return ret;
+}
+
+static inline int rdev_dump_mpp(struct cfg80211_registered_device *rdev,
+ struct net_device *dev, int idx, u8 *dst,
+ u8 *mpp, struct mpath_info *pinfo)
+
+{
+ int ret;
+
+ trace_rdev_dump_mpp(&rdev->wiphy, dev, idx, dst, mpp);
+ ret = rdev->ops->dump_mpp(&rdev->wiphy, dev, idx, dst, mpp, pinfo);
trace_rdev_return_int_mpath_info(&rdev->wiphy, ret, pinfo);
return ret;
}
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 0c524cd..57ab727 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -801,6 +801,51 @@ TRACE_EVENT(rdev_dump_mpath,
MAC_PR_ARG(next_hop))
);

+TRACE_EVENT(rdev_get_mpp,
+ TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
+ u8 *dst, u8 *mpp),
+ TP_ARGS(wiphy, netdev, dst, mpp),
+ TP_STRUCT__entry(
+ WIPHY_ENTRY
+ NETDEV_ENTRY
+ MAC_ENTRY(dst)
+ MAC_ENTRY(mpp)
+ ),
+ TP_fast_assign(
+ WIPHY_ASSIGN;
+ NETDEV_ASSIGN;
+ MAC_ASSIGN(dst, dst);
+ MAC_ASSIGN(mpp, mpp);
+ ),
+ TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", destination: " MAC_PR_FMT
+ ", mpp: " MAC_PR_FMT, WIPHY_PR_ARG, NETDEV_PR_ARG,
+ MAC_PR_ARG(dst), MAC_PR_ARG(mpp))
+);
+
+TRACE_EVENT(rdev_dump_mpp,
+ TP_PROTO(struct wiphy *wiphy, struct net_device *netdev, int idx,
+ u8 *dst, u8 *mpp),
+ TP_ARGS(wiphy, netdev, idx, mpp, dst),
+ TP_STRUCT__entry(
+ WIPHY_ENTRY
+ NETDEV_ENTRY
+ MAC_ENTRY(dst)
+ MAC_ENTRY(mpp)
+ __field(int, idx)
+ ),
+ TP_fast_assign(
+ WIPHY_ASSIGN;
+ NETDEV_ASSIGN;
+ MAC_ASSIGN(dst, dst);
+ MAC_ASSIGN(mpp, mpp);
+ __entry->idx = idx;
+ ),
+ TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", index: %d, destination: "
+ MAC_PR_FMT ", mpp: " MAC_PR_FMT,
+ WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->idx, MAC_PR_ARG(dst),
+ MAC_PR_ARG(mpp))
+);
+
TRACE_EVENT(rdev_return_int_mpath_info,
TP_PROTO(struct wiphy *wiphy, int ret, struct mpath_info *pinfo),
TP_ARGS(wiphy, ret, pinfo),
--
1.9.1


2014-10-09 08:10:46

by Henning Rogge

[permalink] [raw]
Subject: Re: [PATCH v4 2/2] mac80211: implement cfg80211_ops to query mesh proxy path table

On Thu, Oct 9, 2014 at 9:38 AM, Johannes Berg <[email protected]> wrote:
> On Fri, 2014-09-12 at 08:58 +0200, Henning Rogge wrote:
> [...]
>
> In general, this looks fine. However,
>
>> @@ -691,6 +719,9 @@ int mpp_path_add(struct ieee80211_sub_if_data *sdata,
>>
>> spin_unlock(&tbl->hashwlock[hash_idx]);
>> read_unlock_bh(&pathtbl_resize_lock);
>> +
>> + mpp_paths_generation++;
>
> This doesn't seem to be concurrency safe?
>
> Neither is the existing mesh_paths_generation++, I think, so maybe it's
> not something we really need to worry about?

Uhh... I must admit I am not completely sure... this is just my third
kernel patch, so I am still learning about all the arcane locking/RCU
systems of the kernel.

I think it should be reasonable safe. The variable is only increased
(never decreased) and is used as a "information version number" for
the dumps via netlink to the userspace. I think the current userspace
tools ignore the variable completely.

Henning Rogge

2014-10-09 09:18:44

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v4 2/2] mac80211: implement cfg80211_ops to query mesh proxy path table

On Thu, 2014-10-09 at 10:10 +0200, Henning Rogge wrote:

> I think it should be reasonable safe. The variable is only increased
> (never decreased) and is used as a "information version number" for
> the dumps via netlink to the userspace. I think the current userspace
> tools ignore the variable completely.

Fair enough. I'll apply it. If an update is lost, it's likely that
userspace saw a previous value anyway.

johannes


2014-10-09 07:38:13

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v4 2/2] mac80211: implement cfg80211_ops to query mesh proxy path table

On Fri, 2014-09-12 at 08:58 +0200, Henning Rogge wrote:
[...]

In general, this looks fine. However,

> @@ -691,6 +719,9 @@ int mpp_path_add(struct ieee80211_sub_if_data *sdata,
>
> spin_unlock(&tbl->hashwlock[hash_idx]);
> read_unlock_bh(&pathtbl_resize_lock);
> +
> + mpp_paths_generation++;

This doesn't seem to be concurrency safe?

Neither is the existing mesh_paths_generation++, I think, so maybe it's
not something we really need to worry about?

johannes


2014-10-09 09:19:40

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v4 0/2] cfg80211: Add export of mesh proxy path table

On Fri, 2014-09-12 at 08:58 +0200, Henning Rogge wrote:
> The following patch series adds and implements two new cfg80211_ops that
> allow to query the content of the mac80211s mesh proxy path table via
> netlink.

Both applied.

johannes