[PATCH net-next 10/10] net: nl80211: __dev_get_by_index instead of dev_get_by_index to find interface

Ying Xue
2014-01-14T07:42:59Z

As __cfg80211_rdev_from_attrs(), nl80211_dump_wiphy_parse() and
nl80211_set_wiphy() are all under rtnl_lock protection,
__dev_get_by_index() instead of dev_get_by_index() should be used
to find interface handler in them allowing us to avoid to change
interface reference counter.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
---
net/wireless/nl80211.c | 100 +++++++++++++++++-------------------------------
1 file changed, 36 insertions(+), 64 deletions(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b4f40fe..0d4d7fd 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -165,7 +165,7 @@ __cfg80211_rdev_from_attrs(struct net *netns, struct nlattr **attrs)

if (attrs[NL80211_ATTR_IFINDEX]) {
int ifindex = nla_get_u32(attrs[NL80211_ATTR_IFINDEX]);
- netdev = dev_get_by_index(netns, ifindex);
+ netdev = __dev_get_by_index(netns, ifindex);
if (netdev) {
if (netdev->ieee80211_ptr)
tmp = wiphy_to_dev(
@@ -173,8 +173,6 @@ __cfg80211_rdev_from_attrs(struct net *netns, struct nlattr **attrs)
else
tmp = NULL;

- dev_put(netdev);
-
/* not wireless device -- return error */
if (!tmp)
return ERR_PTR(-EINVAL);
@@ -1656,7 +1654,7 @@ static int nl80211_dump_wiphy_parse(struct sk_buff *skb,
struct cfg80211_registered_device *rdev;
int ifidx = nla_get_u32(tb[NL80211_ATTR_IFINDEX]);

- netdev = dev_get_by_index(sock_net(skb->sk), ifidx);
+ netdev = __dev_get_by_index(sock_net(skb->sk), ifidx);
if (!netdev)
return -ENODEV;
if (netdev->ieee80211_ptr) {
@@ -1664,7 +1662,6 @@ static int nl80211_dump_wiphy_parse(struct sk_buff *skb,
netdev->ieee80211_ptr->wiphy);
state->filter_wiphy = rdev->wiphy_idx;
}
- dev_put(netdev);
}

return 0;
@@ -1987,7 +1984,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
if (info->attrs[NL80211_ATTR_IFINDEX]) {
int ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);

- netdev = dev_get_by_index(genl_info_net(info), ifindex);
+ netdev = __dev_get_by_index(genl_info_net(info), ifindex);
if (netdev && netdev->ieee80211_ptr)
rdev = wiphy_to_dev(netdev->ieee80211_ptr->wiphy);
else
@@ -2015,32 +2012,24 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
rdev, nla_data(info->attrs[NL80211_ATTR_WIPHY_NAME]));

if (result)
- goto bad_res;
+ return result;

if (info->attrs[NL80211_ATTR_WIPHY_TXQ_PARAMS]) {
struct ieee80211_txq_params txq_params;
struct nlattr *tb[NL80211_TXQ_ATTR_MAX + 1];

- if (!rdev->ops->set_txq_params) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
+ if (!rdev->ops->set_txq_params)
+ return -EOPNOTSUPP;

- if (!netdev) {
- result = -EINVAL;
- goto bad_res;
- }
+ if (!netdev)
+ return -EINVAL;

if (netdev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP &&
- netdev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO) {
- result = -EINVAL;
- goto bad_res;
- }
+ netdev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
+ return -EINVAL;

- if (!netif_running(netdev)) {
- result = -ENETDOWN;
- goto bad_res;
- }
+ if (!netif_running(netdev))
+ return -ENETDOWN;

nla_for_each_nested(nl_txq_params,
info->attrs[NL80211_ATTR_WIPHY_TXQ_PARAMS],
@@ -2051,12 +2040,12 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
txq_params_policy);
result = parse_txq_params(tb, &txq_params);
if (result)
- goto bad_res;
+ return result;

result = rdev_set_txq_params(rdev, netdev,
&txq_params);
if (result)
- goto bad_res;
+ return result;
}
}

@@ -2065,7 +2054,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
nl80211_can_set_dev_channel(wdev) ? wdev : NULL,
info);
if (result)
- goto bad_res;
+ return result;
}

if (info->attrs[NL80211_ATTR_WIPHY_TX_POWER_SETTING]) {
@@ -2076,19 +2065,15 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
if (!(rdev->wiphy.features & NL80211_FEATURE_VIF_TXPOWER))
txp_wdev = NULL;

- if (!rdev->ops->set_tx_power) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
+ if (!rdev->ops->set_tx_power)
+ return -EOPNOTSUPP;

idx = NL80211_ATTR_WIPHY_TX_POWER_SETTING;
type = nla_get_u32(info->attrs[idx]);

if (!info->attrs[NL80211_ATTR_WIPHY_TX_POWER_LEVEL] &&
- (type != NL80211_TX_POWER_AUTOMATIC)) {
- result = -EINVAL;
- goto bad_res;
- }
+ (type != NL80211_TX_POWER_AUTOMATIC))
+ return -EINVAL;

if (type != NL80211_TX_POWER_AUTOMATIC) {
idx = NL80211_ATTR_WIPHY_TX_POWER_LEVEL;
@@ -2097,7 +2082,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)

result = rdev_set_tx_power(rdev, txp_wdev, type, mbm);
if (result)
- goto bad_res;
+ return result;
}

if (info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX] &&
@@ -2105,10 +2090,8 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
u32 tx_ant, rx_ant;
if ((!rdev->wiphy.available_antennas_tx &&
!rdev->wiphy.available_antennas_rx) ||
- !rdev->ops->set_antenna) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
+ !rdev->ops->set_antenna)
+ return -EOPNOTSUPP;

tx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX]);
rx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]);
@@ -2116,17 +2099,15 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
/* reject antenna configurations which don't match the
* available antenna masks, except for the "all" mask */
if ((~tx_ant && (tx_ant & ~rdev->wiphy.available_antennas_tx)) ||
- (~rx_ant && (rx_ant & ~rdev->wiphy.available_antennas_rx))) {
- result = -EINVAL;
- goto bad_res;
- }
+ (~rx_ant && (rx_ant & ~rdev->wiphy.available_antennas_rx)))
+ return -EINVAL;

tx_ant = tx_ant & rdev->wiphy.available_antennas_tx;
rx_ant = rx_ant & rdev->wiphy.available_antennas_rx;

result = rdev_set_antenna(rdev, tx_ant, rx_ant);
if (result)
- goto bad_res;
+ return result;
}

changed = 0;
@@ -2134,30 +2115,27 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
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;
- }
+ if (retry_short == 0)
+ return -EINVAL;
+
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;
- }
+ if (retry_long == 0)
+ return -EINVAL;
+
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 < 256)
+ return -EINVAL;
+
if (frag_threshold != (u32) -1) {
/*
* Fragments (apart from the last one) are required to
@@ -2187,10 +2165,8 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
u32 old_frag_threshold, old_rts_threshold;
u8 old_coverage_class;

- if (!rdev->ops->set_wiphy_params) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
+ if (!rdev->ops->set_wiphy_params)
+ return -EOPNOTSUPP;

old_retry_short = rdev->wiphy.retry_short;
old_retry_long = rdev->wiphy.retry_long;
@@ -2218,10 +2194,6 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
rdev->wiphy.coverage_class = old_coverage_class;
}
}
-
- bad_res:
- if (netdev)
- dev_put(netdev);
return result;
}

--
1.7.9.5