diff mbox series

[2/2] mac80211: probe unexercised mesh links

Message ID 1550152570-13051-3-git-send-email-rmanohar@codeaurora.org (mailing list archive)
State Changes Requested
Delegated to: Johannes Berg
Headers show
Series wireless: Add support to probe unexercised mesh link | expand

Commit Message

Rajkumar Manoharan Feb. 14, 2019, 1:56 p.m. UTC 
The requirement for mesh link metric refreshing, is that from one
mesh point we be able to send some data frames to other mesh points
which are not currently selected as a primary traffic path, but which
are only 1 hop away. The absence of the primary path to the chosen node
makes it necessary to apply some form of marking on a chosen packet
stream so that the packets can be properly steered to the selected node
for testing, and not by the regular mesh path lookup.

Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
---
 include/net/mac80211.h     |  2 ++
 net/mac80211/cfg.c         |  1 +
 net/mac80211/ieee80211_i.h |  5 +++-
 net/mac80211/mesh_hwmp.c   |  4 +++
 net/mac80211/tdls.c        |  2 +-
 net/mac80211/tx.c          | 66 +++++++++++++++++++++++++++++++++++++++++-----
 6 files changed, 71 insertions(+), 9 deletions(-)

Comments

Johannes Berg Feb. 15, 2019, 10:44 a.m. UTC | #1 
>  void __ieee80211_subif_start_xmit(struct sk_buff *skb,
>  				  struct net_device *dev,
> -				  u32 info_flags);
> +				  u32 info_flags,
> +				  u32 ctrl_flags);

I'd feel better if we could avoid all this, but if you really can't then
I guess we should split this out to a separate patch.

>  
> +	/* Allow injected packets to bypass mesh routing */
> +	if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)

unlikely?

> +int ieee80211_probe_mesh_link(struct wiphy *wiphy, struct net_device *dev,
> +			      const u8 *dest, const u8 *buf, size_t len)
> +{
> +	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
> +	struct ieee80211_local *local = sdata->local;
> +	struct sta_info *sta;
> +	struct sk_buff *skb;
> +	struct ethhdr *ehdr;
> +
> +	if (len < sizeof(*ehdr))
> +		return -EINVAL;
> +
> +	mutex_lock(&local->sta_mtx);
> +	sta = sta_info_get_bss(sdata, dest);
> +	mutex_unlock(&local->sta_mtx);
> +
> +	if (!sta)
> +		return -ENOENT;

better add a comment here that the locking is fine because you only
check *existence* and don't use the sta pointer for anything else

> +	ehdr = (struct ethhdr *)buf;
> +	if (!ether_addr_equal(ehdr->h_dest, dest) ||

that check could be in cfg80211, but then why even bother passing the
"dest" separately?

> +	    !ether_addr_equal(ehdr->h_source, sdata->vif.addr) ||

probably this one too

> +	    is_multicast_ether_addr(ehdr->h_dest))

this one too

But also, ehdr isn't packed I think, you might have alignment issues
here as you don't know how the netlink message looks like? I think?

> +	if (ehdr->h_proto != htons(ETH_P_802_3))
> +		return -EINVAL;

same here

> +	skb = dev_alloc_skb(local->hw.extra_tx_headroom + len);

you should make it a bit bigger so header conversion will fit, I guess?

johannes
Rajkumar Manoharan Feb. 17, 2019, 3:56 p.m. UTC | #2 
On 2019-02-15 02:44, Johannes Berg wrote:
>>  void __ieee80211_subif_start_xmit(struct sk_buff *skb,
>>  				  struct net_device *dev,
>> -				  u32 info_flags);
>> +				  u32 info_flags,
>> +				  u32 ctrl_flags);
> 
> I'd feel better if we could avoid all this, but if you really can't 
> then
> I guess we should split this out to a separate patch.
> 
Hmm.. I don't see any options other than this. no free slot in 
info_flags.
Will split this change.

>> 
>> +	/* Allow injected packets to bypass mesh routing */
>> +	if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
> 
> unlikely?
> 
>> +int ieee80211_probe_mesh_link(struct wiphy *wiphy, struct net_device 
>> *dev,
>> +			      const u8 *dest, const u8 *buf, size_t len)
>> +{
>> +	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
>> +	struct ieee80211_local *local = sdata->local;
>> +	struct sta_info *sta;
>> +	struct sk_buff *skb;
>> +	struct ethhdr *ehdr;
>> +
>> +	if (len < sizeof(*ehdr))
>> +		return -EINVAL;
>> +
>> +	mutex_lock(&local->sta_mtx);
>> +	sta = sta_info_get_bss(sdata, dest);
>> +	mutex_unlock(&local->sta_mtx);
>> +
>> +	if (!sta)
>> +		return -ENOENT;
> 
> better add a comment here that the locking is fine because you only
> check *existence* and don't use the sta pointer for anything else
> 
>> +	ehdr = (struct ethhdr *)buf;
>> +	if (!ether_addr_equal(ehdr->h_dest, dest) ||
> 
> that check could be in cfg80211, but then why even bother passing the
> "dest" separately?
> 
>> +	    !ether_addr_equal(ehdr->h_source, sdata->vif.addr) ||
> 
> probably this one too
> 
>> +	    is_multicast_ether_addr(ehdr->h_dest))
> 
> this one too
> 
Will move all the condition checks to cfg80211.

> But also, ehdr isn't packed I think, you might have alignment issues
> here as you don't know how the netlink message looks like? I think?
> 
>> +	if (ehdr->h_proto != htons(ETH_P_802_3))
>> +		return -EINVAL;
> 
> same here
> 
>> +	skb = dev_alloc_skb(local->hw.extra_tx_headroom + len);
> 
> you should make it a bit bigger so header conversion will fit, I guess?
> 
Hmm. I thought ieee80211_skb_resize in build_hdr will take care of it.

-Rajkumar
diff mbox series

Patch

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 88219cc137c3..65a5889be6b0 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -786,6 +786,7 @@  enum mac80211_tx_info_flags {
  * @IEEE80211_TX_CTRL_RATE_INJECT: This frame is injected with rate information
  * @IEEE80211_TX_CTRL_AMSDU: This frame is an A-MSDU frame
  * @IEEE80211_TX_CTRL_FAST_XMIT: This frame is going through the fast_xmit path
+ * @IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP: This frame skips mesh path lookup
  *
  * These flags are used in tx_info->control.flags.
  */
@@ -795,6 +796,7 @@  enum mac80211_tx_control_flags {
 	IEEE80211_TX_CTRL_RATE_INJECT		= BIT(2),
 	IEEE80211_TX_CTRL_AMSDU			= BIT(3),
 	IEEE80211_TX_CTRL_FAST_XMIT		= BIT(4),
+	IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP	= BIT(5),
 };
 
 /*
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 2493c74c2d37..ceddf7a982f7 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -3974,4 +3974,5 @@  static int ieee80211_get_txq_stats(struct wiphy *wiphy,
 	.get_ftm_responder_stats = ieee80211_get_ftm_responder_stats,
 	.start_pmsr = ieee80211_start_pmsr,
 	.abort_pmsr = ieee80211_abort_pmsr,
+	.probe_mesh_link = ieee80211_probe_mesh_link,
 };
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 7dfb4e2f98b2..2986da5d4fb0 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1736,7 +1736,8 @@  netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 				       struct net_device *dev);
 void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 				  struct net_device *dev,
-				  u32 info_flags);
+				  u32 info_flags,
+				  u32 ctrl_flags);
 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
 			      struct sk_buff_head *skbs);
 struct sk_buff *
@@ -1753,6 +1754,8 @@  void ieee80211_tx_monitor(struct ieee80211_local *local, struct sk_buff *skb,
 int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev,
 			      const u8 *buf, size_t len,
 			      const u8 *dest, __be16 proto, bool unencrypted);
+int ieee80211_probe_mesh_link(struct wiphy *wiphy, struct net_device *dev,
+			      const u8 *dest, const u8 *buf, size_t len);
 
 /* HT */
 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 6950cd0bf594..fe11bbd137ef 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -1118,6 +1118,10 @@  int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
 	if (ieee80211_is_qos_nullfunc(hdr->frame_control))
 		return 0;
 
+	/* Allow injected packets to bypass mesh routing */
+	if (info->control.flags & IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP)
+		return 0;
+
 	rcu_read_lock();
 	err = mesh_nexthop_lookup(sdata, skb);
 	if (!err)
diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index 6c647f425e05..044dad3e0423 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -1055,7 +1055,7 @@  static void ieee80211_tdls_add_ies(struct ieee80211_sub_if_data *sdata,
 
 	/* disable bottom halves when entering the Tx path */
 	local_bh_disable();
-	__ieee80211_subif_start_xmit(skb, dev, flags);
+	__ieee80211_subif_start_xmit(skb, dev, flags, 0);
 	local_bh_enable();
 
 	return ret;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 928f13a208b0..77ae4026aa0b 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2424,6 +2424,7 @@  static int ieee80211_lookup_ra_sta(struct ieee80211_sub_if_data *sdata,
  * @sdata: virtual interface to build the header for
  * @skb: the skb to build the header in
  * @info_flags: skb flags to set
+ * @ctrl_flags: info control flags to set
  *
  * This function takes the skb with 802.3 header and reformats the header to
  * the appropriate IEEE 802.11 header based on which interface the packet is
@@ -2439,7 +2440,7 @@  static int ieee80211_lookup_ra_sta(struct ieee80211_sub_if_data *sdata,
  */
 static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
 					   struct sk_buff *skb, u32 info_flags,
-					   struct sta_info *sta)
+					   struct sta_info *sta, u32 ctrl_flags)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_tx_info *info;
@@ -2811,6 +2812,7 @@  static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
 	info->flags = info_flags;
 	info->ack_frame_id = info_id;
 	info->band = band;
+	info->control.flags = ctrl_flags;
 
 	return skb;
  free:
@@ -3638,7 +3640,8 @@  struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
 
 void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 				  struct net_device *dev,
-				  u32 info_flags)
+				  u32 info_flags,
+				  u32 ctrl_flags)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct sta_info *sta;
@@ -3703,7 +3706,8 @@  void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 		skb->prev = NULL;
 		skb->next = NULL;
 
-		skb = ieee80211_build_hdr(sdata, skb, info_flags, sta);
+		skb = ieee80211_build_hdr(sdata, skb, info_flags,
+					  sta, ctrl_flags);
 		if (IS_ERR(skb))
 			goto out;
 
@@ -3843,9 +3847,9 @@  netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 		__skb_queue_head_init(&queue);
 		ieee80211_convert_to_unicast(skb, dev, &queue);
 		while ((skb = __skb_dequeue(&queue)))
-			__ieee80211_subif_start_xmit(skb, dev, 0);
+			__ieee80211_subif_start_xmit(skb, dev, 0, 0);
 	} else {
-		__ieee80211_subif_start_xmit(skb, dev, 0);
+		__ieee80211_subif_start_xmit(skb, dev, 0, 0);
 	}
 
 	return NETDEV_TX_OK;
@@ -3870,7 +3874,7 @@  struct sk_buff *
 		goto out;
 	}
 
-	skb = ieee80211_build_hdr(sdata, skb, info_flags, sta);
+	skb = ieee80211_build_hdr(sdata, skb, info_flags, sta, 0);
 	if (IS_ERR(skb))
 		goto out;
 
@@ -4907,7 +4911,55 @@  int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev,
 	skb_reset_mac_header(skb);
 
 	local_bh_disable();
-	__ieee80211_subif_start_xmit(skb, skb->dev, flags);
+	__ieee80211_subif_start_xmit(skb, skb->dev, flags, 0);
+	local_bh_enable();
+
+	return 0;
+}
+
+int ieee80211_probe_mesh_link(struct wiphy *wiphy, struct net_device *dev,
+			      const u8 *dest, const u8 *buf, size_t len)
+{
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_local *local = sdata->local;
+	struct sta_info *sta;
+	struct sk_buff *skb;
+	struct ethhdr *ehdr;
+
+	if (len < sizeof(*ehdr))
+		return -EINVAL;
+
+	mutex_lock(&local->sta_mtx);
+	sta = sta_info_get_bss(sdata, dest);
+	mutex_unlock(&local->sta_mtx);
+
+	if (!sta)
+		return -ENOENT;
+
+	ehdr = (struct ethhdr *)buf;
+	if (!ether_addr_equal(ehdr->h_dest, dest) ||
+	    !ether_addr_equal(ehdr->h_source, sdata->vif.addr) ||
+	    is_multicast_ether_addr(ehdr->h_dest))
+		return -EINVAL;
+
+	if (ehdr->h_proto != htons(ETH_P_802_3))
+		return -EINVAL;
+
+	skb = dev_alloc_skb(local->hw.extra_tx_headroom + len);
+	if (!skb)
+		return -ENOMEM;
+
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+	skb_put_data(skb, buf, len);
+
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_802_3);
+	skb_reset_network_header(skb);
+	skb_reset_mac_header(skb);
+
+	local_bh_disable();
+	__ieee80211_subif_start_xmit(skb, skb->dev, 0,
+				     IEEE80211_TX_CTRL_SKIP_MPATH_LOOKUP);
 	local_bh_enable();
 
 	return 0;