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Date: Tue, 6 Mar 2012 12:45:30 -0800
Message-ID: <CACcxo+oB3-j46ZRM47w5hTdDHKy0BpCOHZk3U4e78hV_Hk1XZw@mail.gmail.com> (sfid-20120306_214536_191313_17DA8A93)
Subject: Re: [PATCH v4] {nl,cfg,mac}80211: Implement RSSI threshold for mesh peering
From: Ashok Nagarajan <ashok@cozybit.com>
To: linux-wireless@vger.kernel.org
Cc: dan.carpenter@oracle.com, Ashok Nagarajan <ashok@cozybit.com>
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Sender: linux-wireless-owner@vger.kernel.org

Please don't apply this patch. A fix-up patch is coming.

Thanks,
Ashok

On Tue, Mar 6, 2012 at 11:23 AM, Ashok Nagarajan <ashok@cozybit.com> wrote:
> Mesh peer links are established only if average rssi of the peer
> candidate satisfies the threshold. This is not in 802.11s specification
> but was requested by David Fulgham, an open80211s user. This is a way to avoid
> marginal peer links with stations that are barely within range.
>
> This patch adds a new mesh configuration parameter, mesh_rssi_threshold. This
> feature is supported only for hardwares that report signal in dBm.
>
> Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
> Signed-off-by: Javier Cardona <javier@cozybit.com>
> ---
> v3:
> use s32 instead of int32_t (Kalle Valo)
> Feature to be supported for devices reporting signal in dBm (Johannes)
>
> v4:
> Fix potential null pointer deferencing (Dan Carpenter)
>
> ?include/linux/nl80211.h ? ? ? | ? ?5 +++++
> ?include/net/cfg80211.h ? ? ? ?| ? ?1 +
> ?net/mac80211/cfg.c ? ? ? ? ? ?| ? ?8 ++++++++
> ?net/mac80211/debugfs_netdev.c | ? ?2 ++
> ?net/mac80211/mesh_plink.c ? ? | ? 17 ++++++++++++++++-
> ?net/wireless/mesh.c ? ? ? ? ? | ? ?3 +++
> ?net/wireless/nl80211.c ? ? ? ?| ? ?5 +++++
> ?7 files changed, 40 insertions(+), 1 deletions(-)
>
> diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
> index be35a68..d6ae590 100644
> --- a/include/linux/nl80211.h
> +++ b/include/linux/nl80211.h
> @@ -2112,6 +2112,10 @@ enum nl80211_mntr_flags {
> ?* @NL80211_MESHCONF_FORWARDING: set Mesh STA as forwarding or non-forwarding
> ?* or forwarding entity (default is TRUE - forwarding entity)
> ?*
> + * @NL80211_MESHCONF_RSSI_THRESHOLD: RSSI threshold in dBm. This specifies the
> + * threshold for average signal strength of candidate station to establish
> + * a peer link.
> + ?*
> ?* @NL80211_MESHCONF_ATTR_MAX: highest possible mesh configuration attribute
> ?*
> ?* @__NL80211_MESHCONF_ATTR_AFTER_LAST: internal use
> @@ -2137,6 +2141,7 @@ enum nl80211_meshconf_params {
> ? ? ? ?NL80211_MESHCONF_GATE_ANNOUNCEMENTS,
> ? ? ? ?NL80211_MESHCONF_HWMP_PERR_MIN_INTERVAL,
> ? ? ? ?NL80211_MESHCONF_FORWARDING,
> + ? ? ? NL80211_MESHCONF_RSSI_THRESHOLD,
>
> ? ? ? ?/* keep last */
> ? ? ? ?__NL80211_MESHCONF_ATTR_AFTER_LAST,
> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
> index 755a770..27e54e3 100644
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -809,6 +809,7 @@ struct mesh_config {
> ? ? ? ? * Still keeping the same nomenclature to be in sync with the spec. */
> ? ? ? ?bool ?dot11MeshGateAnnouncementProtocol;
> ? ? ? ?bool dot11MeshForwarding;
> + ? ? ? s32 ?rssi_threshold;
> ?};
>
> ?/**
> diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
> index f7eb25a..ef9bbb8 100644
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -1314,6 +1314,14 @@ static int ieee80211_update_mesh_config(struct wiphy *wiphy,
> ? ? ? ?}
> ? ? ? ?if (_chg_mesh_attr(NL80211_MESHCONF_FORWARDING, mask))
> ? ? ? ? ? ? ? ?conf->dot11MeshForwarding = nconf->dot11MeshForwarding;
> + ? ? ? if (_chg_mesh_attr(NL80211_MESHCONF_RSSI_THRESHOLD, mask)) {
> + ? ? ? ? ? ? ? /* our RSSI threshold implementation is supported only for
> + ? ? ? ? ? ? ? ?* devices that report signal in dBm.
> + ? ? ? ? ? ? ? ?*/
> + ? ? ? ? ? ? ? if (!(sdata->local->hw.flags & IEEE80211_HW_SIGNAL_DBM))
> + ? ? ? ? ? ? ? ? ? ? ? return -ENOTSUPP;
> + ? ? ? ? ? ? ? conf->rssi_threshold = nconf->rssi_threshold;
> + ? ? ? }
> ? ? ? ?return 0;
> ?}
>
> diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
> index 510ed1d..9f484d8 100644
> --- a/net/mac80211/debugfs_netdev.c
> +++ b/net/mac80211/debugfs_netdev.c
> @@ -443,6 +443,7 @@ IEEE80211_IF_FILE(dot11MeshGateAnnouncementProtocol,
> ?IEEE80211_IF_FILE(dot11MeshHWMPRannInterval,
> ? ? ? ? ? ? ? ?u.mesh.mshcfg.dot11MeshHWMPRannInterval, DEC);
> ?IEEE80211_IF_FILE(dot11MeshForwarding, u.mesh.mshcfg.dot11MeshForwarding, DEC);
> +IEEE80211_IF_FILE(rssi_threshold, u.mesh.mshcfg.rssi_threshold, DEC);
> ?#endif
>
>
> @@ -581,6 +582,7 @@ static void add_mesh_config(struct ieee80211_sub_if_data *sdata)
> ? ? ? ?MESHPARAMS_ADD(dot11MeshHWMPRootMode);
> ? ? ? ?MESHPARAMS_ADD(dot11MeshHWMPRannInterval);
> ? ? ? ?MESHPARAMS_ADD(dot11MeshGateAnnouncementProtocol);
> + ? ? ? MESHPARAMS_ADD(rssi_threshold);
> ?#undef MESHPARAMS_ADD
> ?}
> ?#endif
> diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
> index 8806e5e..4e53c4c 100644
> --- a/net/mac80211/mesh_plink.c
> +++ b/net/mac80211/mesh_plink.c
> @@ -31,6 +31,12 @@
> ?#define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
> ?#define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
>
> +/* We only need a valid sta if user configured a minimum rssi_threshold. */
> +#define rssi_threshold_check(sta, sdata) \
> + ? ? ? ? ? ? ? (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
> + ? ? ? ? ? ? ? (sta && (s8) -ewma_read(&sta->avg_signal) > \
> + ? ? ? ? ? ? ? sdata->u.mesh.mshcfg.rssi_threshold))
> +
> ?enum plink_event {
> ? ? ? ?PLINK_UNDEFINED,
> ? ? ? ?OPN_ACPT,
> @@ -301,7 +307,8 @@ void mesh_neighbour_update(u8 *hw_addr, u32 rates,
> ? ? ? ?if (mesh_peer_accepts_plinks(elems) &&
> ? ? ? ? ? ? ? ? ? ? ? ?sta->plink_state == NL80211_PLINK_LISTEN &&
> ? ? ? ? ? ? ? ? ? ? ? ?sdata->u.mesh.accepting_plinks &&
> - ? ? ? ? ? ? ? ? ? ? ? sdata->u.mesh.mshcfg.auto_open_plinks)
> + ? ? ? ? ? ? ? ? ? ? ? sdata->u.mesh.mshcfg.auto_open_plinks &&
> + ? ? ? ? ? ? ? ? ? ? ? rssi_threshold_check(sta, sdata))
> ? ? ? ? ? ? ? ?mesh_plink_open(sta);
>
> ? ? ? ?rcu_read_unlock();
> @@ -531,6 +538,14 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m
> ? ? ? ? ? ? ? ?return;
> ? ? ? ?}
>
> + ? ? ? if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
> + ? ? ? ? ? !rssi_threshold_check(sta, sdata)) {
> + ? ? ? ? ? ? ? mpl_dbg("Mesh plink: %pM does not meet rssi threshold\n",
> + ? ? ? ? ? ? ? ? ? ? ? mgmt->sa);
> + ? ? ? ? ? ? ? rcu_read_unlock();
> + ? ? ? ? ? ? ? return;
> + ? ? ? }
> +
> ? ? ? ?if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
> ? ? ? ? ? ? ? ?mpl_dbg("Mesh plink: Action frame from non-authed peer\n");
> ? ? ? ? ? ? ? ?rcu_read_unlock();
> diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
> index 9d3e3b6..ba21ab2 100644
> --- a/net/wireless/mesh.c
> +++ b/net/wireless/mesh.c
> @@ -23,6 +23,8 @@
> ?#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
> @@ -56,6 +58,7 @@ const struct mesh_config default_mesh_config = {
> ? ? ? ?.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
> ? ? ? ?.dot11MeshGateAnnouncementProtocol = false,
> ? ? ? ?.dot11MeshForwarding = true,
> + ? ? ? .rssi_threshold = MESH_RSSI_THRESHOLD,
> ?};
>
> ?const struct mesh_setup default_mesh_setup = {
> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
> index 1998c36..25a470a 100644
> --- a/net/wireless/nl80211.c
> +++ b/net/wireless/nl80211.c
> @@ -3290,6 +3290,8 @@ static int nl80211_get_mesh_config(struct sk_buff *skb,
> ? ? ? ? ? ? ? ? ? ? ? ?cur_params.dot11MeshGateAnnouncementProtocol);
> ? ? ? ?NLA_PUT_U8(msg, NL80211_MESHCONF_FORWARDING,
> ? ? ? ? ? ? ? ? ? ? ? ?cur_params.dot11MeshForwarding);
> + ? ? ? NLA_PUT_U32(msg, NL80211_MESHCONF_RSSI_THRESHOLD,
> + ? ? ? ? ? ? ? ? ? ? ? cur_params.rssi_threshold);
> ? ? ? ?nla_nest_end(msg, pinfoattr);
> ? ? ? ?genlmsg_end(msg, hdr);
> ? ? ? ?return genlmsg_reply(msg, info);
> @@ -3322,6 +3324,7 @@ static const struct nla_policy nl80211_meshconf_params_policy[NL80211_MESHCONF_A
> ? ? ? ?[NL80211_MESHCONF_HWMP_RANN_INTERVAL] = { .type = NLA_U16 },
> ? ? ? ?[NL80211_MESHCONF_GATE_ANNOUNCEMENTS] = { .type = NLA_U8 },
> ? ? ? ?[NL80211_MESHCONF_FORWARDING] = { .type = NLA_U8 },
> + ? ? ? [NL80211_MESHCONF_RSSI_THRESHOLD] = { .type = NLA_U32},
> ?};
>
> ?static const struct nla_policy
> @@ -3413,6 +3416,8 @@ do {\
> ? ? ? ? ? ? ? ? ? ? ? ?nla_get_u8);
> ? ? ? ?FILL_IN_MESH_PARAM_IF_SET(tb, cfg, dot11MeshForwarding,
> ? ? ? ? ? ? ? ? ? ? ? ?mask, NL80211_MESHCONF_FORWARDING, nla_get_u8);
> + ? ? ? FILL_IN_MESH_PARAM_IF_SET(tb, cfg, rssi_threshold,
> + ? ? ? ? ? ? ? ? ? ? ? mask, NL80211_MESHCONF_RSSI_THRESHOLD, nla_get_u32);
> ? ? ? ?if (mask_out)
> ? ? ? ? ? ? ? ?*mask_out = mask;
>
> --
> 1.7.5.4
>