nl80211: Add set/get for frag/rts threshold and retry limits

Add new nl80211 attributes that can be used with NL80211_CMD_SET_WIPHY
and NL80211_CMD_GET_WIPHY to manage fragmentation/RTS threshold and
retry limits.

Since these values are stored in struct wiphy, remove the local copy
from mac80211 where feasible (frag & rts threshold). The retry limits
are currently needed in struct ieee80211_conf, but these could be
eventually removed since the driver should have access to the values
in struct wiphy.

Signed-off-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 256 insertions, 0 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 827a56263551..f256b4f7e833 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -273,6 +273,16 @@ struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
         drv->wiphy.dev.class = &ieee80211_class;
         drv->wiphy.dev.platform_data = drv;
 
+        /*
+         * Initialize wiphy parameters to IEEE 802.11 MIB default values.
+         * Fragmentation and RTS threshold are disabled by default with the
+         * special -1 value.
+         */
+        drv->wiphy.retry_short = 7;
+        drv->wiphy.retry_long = 4;
+        drv->wiphy.frag_threshold = (u32) -1;
+        drv->wiphy.rts_threshold = (u32) -1;
+
         return &drv->wiphy;
 }
 EXPORT_SYMBOL(wiphy_new);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 16f86356ac97..5a9a5c6c71db 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -61,6 +61,10 @@ static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
         [NL80211_ATTR_WIPHY_TXQ_PARAMS] = { .type = NLA_NESTED },
         [NL80211_ATTR_WIPHY_FREQ] = { .type = NLA_U32 },
         [NL80211_ATTR_WIPHY_CHANNEL_TYPE] = { .type = NLA_U32 },
+        [NL80211_ATTR_WIPHY_RETRY_SHORT] = { .type = NLA_U8 },
+        [NL80211_ATTR_WIPHY_RETRY_LONG] = { .type = NLA_U8 },
+        [NL80211_ATTR_WIPHY_FRAG_THRESHOLD] = { .type = NLA_U32 },
+        [NL80211_ATTR_WIPHY_RTS_THRESHOLD] = { .type = NLA_U32 },
 
         [NL80211_ATTR_IFTYPE] = { .type = NLA_U32 },
         [NL80211_ATTR_IFINDEX] = { .type = NLA_U32 },
@@ -204,6 +208,16 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
 
         NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, dev->wiphy_idx);
         NLA_PUT_STRING(msg, NL80211_ATTR_WIPHY_NAME, wiphy_name(&dev->wiphy));
+
+        NLA_PUT_U8(msg, NL80211_ATTR_WIPHY_RETRY_SHORT,
+                   dev->wiphy.retry_short);
+        NLA_PUT_U8(msg, NL80211_ATTR_WIPHY_RETRY_LONG,
+                   dev->wiphy.retry_long);
+        NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_FRAG_THRESHOLD,
+                    dev->wiphy.frag_threshold);
+        NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_RTS_THRESHOLD,
+                    dev->wiphy.rts_threshold);
+
         NLA_PUT_U8(msg, NL80211_ATTR_MAX_NUM_SCAN_SSIDS,
                    dev->wiphy.max_scan_ssids);
         NLA_PUT_U16(msg, NL80211_ATTR_MAX_SCAN_IE_LEN,
@@ -416,6 +430,9 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
         struct cfg80211_registered_device *rdev;
         int result = 0, rem_txq_params = 0;
         struct nlattr *nl_txq_params;
+        u32 changed;
+        u8 retry_short = 0, retry_long = 0;
+        u32 frag_threshold = 0, rts_threshold = 0;
 
         rtnl_lock();
 
@@ -530,6 +547,84 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
                         goto bad_res;
         }
 
+        changed = 0;
+
+        if (info->attrs[NL80211_ATTR_WIPHY_RETRY_SHORT]) {
+                retry_short = nla_get_u8(
+                        info->attrs[NL80211_ATTR_WIPHY_RETRY_SHORT]);
+                if (retry_short == 0) {
+                        result = -EINVAL;
+                        goto bad_res;
+                }
+                changed |= WIPHY_PARAM_RETRY_SHORT;
+        }
+
+        if (info->attrs[NL80211_ATTR_WIPHY_RETRY_LONG]) {
+                retry_long = nla_get_u8(
+                        info->attrs[NL80211_ATTR_WIPHY_RETRY_LONG]);
+                if (retry_long == 0) {
+                        result = -EINVAL;
+                        goto bad_res;
+                }
+                changed |= WIPHY_PARAM_RETRY_LONG;
+        }
+
+        if (info->attrs[NL80211_ATTR_WIPHY_FRAG_THRESHOLD]) {
+                frag_threshold = nla_get_u32(
+                        info->attrs[NL80211_ATTR_WIPHY_FRAG_THRESHOLD]);
+                if (frag_threshold < 256) {
+                        result = -EINVAL;
+                        goto bad_res;
+                }
+                if (frag_threshold != (u32) -1) {
+                        /*
+                         * Fragments (apart from the last one) are required to
+                         * have even length. Make the fragmentation code
+                         * simpler by stripping LSB should someone try to use
+                         * odd threshold value.
+                         */
+                        frag_threshold &= ~0x1;
+                }
+                changed |= WIPHY_PARAM_FRAG_THRESHOLD;
+        }
+
+        if (info->attrs[NL80211_ATTR_WIPHY_RTS_THRESHOLD]) {
+                rts_threshold = nla_get_u32(
+                        info->attrs[NL80211_ATTR_WIPHY_RTS_THRESHOLD]);
+                changed |= WIPHY_PARAM_RTS_THRESHOLD;
+        }
+
+        if (changed) {
+                u8 old_retry_short, old_retry_long;
+                u32 old_frag_threshold, old_rts_threshold;
+
+                if (!rdev->ops->set_wiphy_params) {
+                        result = -EOPNOTSUPP;
+                        goto bad_res;
+                }
+
+                old_retry_short = rdev->wiphy.retry_short;
+                old_retry_long = rdev->wiphy.retry_long;
+                old_frag_threshold = rdev->wiphy.frag_threshold;
+                old_rts_threshold = rdev->wiphy.rts_threshold;
+
+                if (changed & WIPHY_PARAM_RETRY_SHORT)
+                        rdev->wiphy.retry_short = retry_short;
+                if (changed & WIPHY_PARAM_RETRY_LONG)
+                        rdev->wiphy.retry_long = retry_long;
+                if (changed & WIPHY_PARAM_FRAG_THRESHOLD)
+                        rdev->wiphy.frag_threshold = frag_threshold;
+                if (changed & WIPHY_PARAM_RTS_THRESHOLD)
+                        rdev->wiphy.rts_threshold = rts_threshold;
+
+                result = rdev->ops->set_wiphy_params(&rdev->wiphy, changed);
+                if (result) {
+                        rdev->wiphy.retry_short = old_retry_short;
+                        rdev->wiphy.retry_long = old_retry_long;
+                        rdev->wiphy.frag_threshold = old_frag_threshold;
+                        rdev->wiphy.rts_threshold = old_rts_threshold;
+                }
+        }
 
  bad_res:
         mutex_unlock(&rdev->mtx);
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 4e054ea9c0a0..3279e7f038dc 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -314,3 +314,154 @@ struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
 
 }
 EXPORT_SYMBOL(cfg80211_wext_freq);
+
+int cfg80211_wext_siwrts(struct net_device *dev,
+                         struct iw_request_info *info,
+                         struct iw_param *rts, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+        u32 orts = wdev->wiphy->rts_threshold;
+        int err;
+
+        if (rts->disabled || !rts->fixed)
+                wdev->wiphy->rts_threshold = (u32) -1;
+        else if (rts->value < 0)
+                return -EINVAL;
+        else
+                wdev->wiphy->rts_threshold = rts->value;
+
+        err = rdev->ops->set_wiphy_params(wdev->wiphy,
+                                          WIPHY_PARAM_RTS_THRESHOLD);
+        if (err)
+                wdev->wiphy->rts_threshold = orts;
+
+        return err;
+}
+EXPORT_SYMBOL(cfg80211_wext_siwrts);
+
+int cfg80211_wext_giwrts(struct net_device *dev,
+                         struct iw_request_info *info,
+                         struct iw_param *rts, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+        rts->value = wdev->wiphy->rts_threshold;
+        rts->disabled = rts->value == (u32) -1;
+        rts->fixed = 1;
+
+        return 0;
+}
+EXPORT_SYMBOL(cfg80211_wext_giwrts);
+
+int cfg80211_wext_siwfrag(struct net_device *dev,
+                          struct iw_request_info *info,
+                          struct iw_param *frag, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+        u32 ofrag = wdev->wiphy->frag_threshold;
+        int err;
+
+        if (frag->disabled || !frag->fixed)
+                wdev->wiphy->frag_threshold = (u32) -1;
+        else if (frag->value < 256)
+                return -EINVAL;
+        else {
+                /* Fragment length must be even, so strip LSB. */
+                wdev->wiphy->frag_threshold = frag->value & ~0x1;
+        }
+
+        err = rdev->ops->set_wiphy_params(wdev->wiphy,
+                                          WIPHY_PARAM_FRAG_THRESHOLD);
+        if (err)
+                wdev->wiphy->frag_threshold = ofrag;
+
+        return err;
+}
+EXPORT_SYMBOL(cfg80211_wext_siwfrag);
+
+int cfg80211_wext_giwfrag(struct net_device *dev,
+                          struct iw_request_info *info,
+                          struct iw_param *frag, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+        frag->value = wdev->wiphy->frag_threshold;
+        frag->disabled = frag->value == (u32) -1;
+        frag->fixed = 1;
+
+        return 0;
+}
+EXPORT_SYMBOL(cfg80211_wext_giwfrag);
+
+int cfg80211_wext_siwretry(struct net_device *dev,
+                           struct iw_request_info *info,
+                           struct iw_param *retry, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+        struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+        u32 changed = 0;
+        u8 olong = wdev->wiphy->retry_long;
+        u8 oshort = wdev->wiphy->retry_short;
+        int err;
+
+        if (retry->disabled ||
+            (retry->flags & IW_RETRY_TYPE) != IW_RETRY_LIMIT)
+                return -EINVAL;
+
+        if (retry->flags & IW_RETRY_LONG) {
+                wdev->wiphy->retry_long = retry->value;
+                changed |= WIPHY_PARAM_RETRY_LONG;
+        } else if (retry->flags & IW_RETRY_SHORT) {
+                wdev->wiphy->retry_short = retry->value;
+                changed |= WIPHY_PARAM_RETRY_SHORT;
+        } else {
+                wdev->wiphy->retry_short = retry->value;
+                wdev->wiphy->retry_long = retry->value;
+                changed |= WIPHY_PARAM_RETRY_LONG;
+                changed |= WIPHY_PARAM_RETRY_SHORT;
+        }
+
+        if (!changed)
+                return 0;
+
+        err = rdev->ops->set_wiphy_params(wdev->wiphy, changed);
+        if (err) {
+                wdev->wiphy->retry_short = oshort;
+                wdev->wiphy->retry_long = olong;
+        }
+
+        return err;
+}
+EXPORT_SYMBOL(cfg80211_wext_siwretry);
+
+int cfg80211_wext_giwretry(struct net_device *dev,
+                           struct iw_request_info *info,
+                           struct iw_param *retry, char *extra)
+{
+        struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+        retry->disabled = 0;
+
+        if (retry->flags == 0 || (retry->flags & IW_RETRY_SHORT)) {
+                /*
+                 * First return short value, iwconfig will ask long value
+                 * later if needed
+                 */
+                retry->flags |= IW_RETRY_LIMIT;
+                retry->value = wdev->wiphy->retry_short;
+                if (wdev->wiphy->retry_long != wdev->wiphy->retry_short)
+                        retry->flags |= IW_RETRY_LONG;
+
+                return 0;
+        }
+
+        if (retry->flags & IW_RETRY_LONG) {
+                retry->flags = IW_RETRY_LIMIT | IW_RETRY_LONG;
+                retry->value = wdev->wiphy->retry_long;
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL(cfg80211_wext_giwretry);