nl80211: add testmode dump support

This adds dump support to testmode. The testmode
dump support in nl80211 requires using two of the
six cb->args, the rest can be used by the driver
to figure out where the dump position is at or to
store other data across invocations.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 102 insertions, 0 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index be70c70..6e56c6e 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1554,6 +1554,19 @@ static int ieee80211_testmode_cmd(struct wiphy *wiphy, void *data, int len)
 
 	return local->ops->testmode_cmd(&local->hw, data, len);
 }
+
+static int ieee80211_testmode_dump(struct wiphy *wiphy,
+				   struct sk_buff *skb,
+				   struct netlink_callback *cb,
+				   void *data, int len)
+{
+	struct ieee80211_local *local = wiphy_priv(wiphy);
+
+	if (!local->ops->testmode_dump)
+		return -EOPNOTSUPP;
+
+	return local->ops->testmode_dump(&local->hw, skb, cb, data, len);
+}
 #endif
 
 int __ieee80211_request_smps(struct ieee80211_sub_if_data *sdata,
@@ -2134,6 +2147,7 @@ struct cfg80211_ops mac80211_config_ops = {
 	.set_wds_peer = ieee80211_set_wds_peer,
 	.rfkill_poll = ieee80211_rfkill_poll,
 	CFG80211_TESTMODE_CMD(ieee80211_testmode_cmd)
+	CFG80211_TESTMODE_DUMP(ieee80211_testmode_dump)
 	.set_power_mgmt = ieee80211_set_power_mgmt,
 	.set_bitrate_mask = ieee80211_set_bitrate_mask,
 	.remain_on_channel = ieee80211_remain_on_channel,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 88a565f..6d0d44b 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4361,6 +4361,93 @@ static int nl80211_testmode_do(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+static int nl80211_testmode_dump(struct sk_buff *skb,
+				 struct netlink_callback *cb)
+{
+	struct cfg80211_registered_device *dev;
+	int err;
+	long phy_idx;
+	void *data = NULL;
+	int data_len = 0;
+
+	if (cb->args[0]) {
+		/*
+		 * 0 is a valid index, but not valid for args[0],
+		 * so we need to offset by 1.
+		 */
+		phy_idx = cb->args[0] - 1;
+	} else {
+		err = nlmsg_parse(cb->nlh, GENL_HDRLEN + nl80211_fam.hdrsize,
+				  nl80211_fam.attrbuf, nl80211_fam.maxattr,
+				  nl80211_policy);
+		if (err)
+			return err;
+		if (!nl80211_fam.attrbuf[NL80211_ATTR_WIPHY])
+			return -EINVAL;
+		phy_idx = nla_get_u32(nl80211_fam.attrbuf[NL80211_ATTR_WIPHY]);
+		if (nl80211_fam.attrbuf[NL80211_ATTR_TESTDATA])
+			cb->args[1] =
+				(long)nl80211_fam.attrbuf[NL80211_ATTR_TESTDATA];
+	}
+
+	if (cb->args[1]) {
+		data = nla_data((void *)cb->args[1]);
+		data_len = nla_len((void *)cb->args[1]);
+	}
+
+	mutex_lock(&cfg80211_mutex);
+	dev = cfg80211_rdev_by_wiphy_idx(phy_idx);
+	if (!dev) {
+		mutex_unlock(&cfg80211_mutex);
+		return -ENOENT;
+	}
+	cfg80211_lock_rdev(dev);
+	mutex_unlock(&cfg80211_mutex);
+
+	if (!dev->ops->testmode_dump) {
+		err = -EOPNOTSUPP;
+		goto out_err;
+	}
+
+	while (1) {
+		void *hdr = nl80211hdr_put(skb, NETLINK_CB(cb->skb).pid,
+					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
+					   NL80211_CMD_TESTMODE);
+		struct nlattr *tmdata;
+
+		if (nla_put_u32(skb, NL80211_ATTR_WIPHY, dev->wiphy_idx) < 0) {
+			genlmsg_cancel(skb, hdr);
+			break;
+		}
+
+		tmdata = nla_nest_start(skb, NL80211_ATTR_TESTDATA);
+		if (!tmdata) {
+			genlmsg_cancel(skb, hdr);
+			break;
+		}
+		err = dev->ops->testmode_dump(&dev->wiphy, skb, cb,
+					      data, data_len);
+		nla_nest_end(skb, tmdata);
+
+		if (err == -ENOBUFS || err == -ENOENT) {
+			genlmsg_cancel(skb, hdr);
+			break;
+		} else if (err) {
+			genlmsg_cancel(skb, hdr);
+			goto out_err;
+		}
+
+		genlmsg_end(skb, hdr);
+	}
+
+	err = skb->len;
+	/* see above */
+	cb->args[0] = phy_idx + 1;
+ out_err:
+	cfg80211_unlock_rdev(dev);
+	return err;
+}
+
 static struct sk_buff *
 __cfg80211_testmode_alloc_skb(struct cfg80211_registered_device *rdev,
 			      int approxlen, u32 pid, u32 seq, gfp_t gfp)
@@ -5658,6 +5745,7 @@ static struct genl_ops nl80211_ops[] = {
 	{
 		.cmd = NL80211_CMD_TESTMODE,
 		.doit = nl80211_testmode_do,
+		.dumpit = nl80211_testmode_dump,
 		.policy = nl80211_policy,
 		.flags = GENL_ADMIN_PERM,
 		.internal_flags = NL80211_FLAG_NEED_WIPHY |