wifi: cfg80211: Add support for setting TID to link mapping

Add support for setting the TID to link mapping for a non-AP MLD
station.

This is useful in cases user space needs to restrict the possible
set of active links, e.g., since it got a BSS Transition Management
request forcing to use only a subset of the valid links etc.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20231211085121.da4d56a5f3ff.Iacf88e943326bf9c169c49b728c4a3445fdedc97@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -1673,6 +1673,21 @@ struct link_station_del_parameters {
 	u32 link_id;
 };
 
+/**
+ * struct cfg80211_ttlm_params: TID to link mapping parameters
+ *
+ * Used for setting a TID to link mapping.
+ *
+ * @dlink: Downlink TID to link mapping, as defined in section 9.4.2.314
+ *     (TID-To-Link Mapping element) in Draft P802.11be_D4.0.
+ * @ulink: Uplink TID to link mapping, as defined in section 9.4.2.314
+ *     (TID-To-Link Mapping element) in Draft P802.11be_D4.0.
+ */
+struct cfg80211_ttlm_params {
+	u16 dlink[8];
+	u16 ulink[8];
+};
+
 /**
  * struct station_parameters - station parameters
  *
@@ -4523,6 +4538,7 @@ struct mgmt_frame_regs {
  * @del_link_station: Remove a link of a station.
  *
  * @set_hw_timestamp: Enable/disable HW timestamping of TM/FTM frames.
+ * @set_ttlm: set the TID to link mapping.
  */
 struct cfg80211_ops {
 	int	(*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -4882,6 +4898,8 @@ struct cfg80211_ops {
 				    struct link_station_del_parameters *params);
 	int	(*set_hw_timestamp)(struct wiphy *wiphy, struct net_device *dev,
 				    struct cfg80211_set_hw_timestamp *hwts);
+	int	(*set_ttlm)(struct wiphy *wiphy, struct net_device *dev,
+			    struct cfg80211_ttlm_params *params);
 };
 
 /*

include/uapi/linux/nl80211.h

@@ -1328,6 +1328,11 @@
  *	Multi-Link reconfiguration. %NL80211_ATTR_MLO_LINKS is used to provide
  *	information about the removed STA MLD setup links.
  *
+ * @NL80211_CMD_SET_TID_TO_LINK_MAPPING: Set the TID to Link Mapping for a
+ *      non-AP MLD station. The %NL80211_ATTR_MLO_TTLM_DLINK and
+ *      %NL80211_ATTR_MLO_TTLM_ULINK attributes are used to specify the
+ *      TID to Link mapping for downlink/uplink traffic.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -1583,6 +1588,8 @@ enum nl80211_commands {
 
 	NL80211_CMD_LINKS_REMOVED,
 
+	NL80211_CMD_SET_TID_TO_LINK_MAPPING,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */
@@ -2835,6 +2842,15 @@ enum nl80211_commands {
  *	include BSSes that can only be used in restricted scenarios and/or
  *	cannot be used at all.
  *
+ * @NL80211_ATTR_MLO_TTLM_DLINK: Binary attribute specifying the downlink TID to
+ *      link mapping. The length is 8 * sizeof(u16). For each TID the link
+ *      mapping is as defined in section 9.4.2.314 (TID-To-Link Mapping element)
+ *      in Draft P802.11be_D4.0.
+ * @NL80211_ATTR_MLO_TTLM_ULINK: Binary attribute specifying the uplink TID to
+ *      link mapping. The length is 8 * sizeof(u16). For each TID the link
+ *      mapping is as defined in section 9.4.2.314 (TID-To-Link Mapping element)
+ *      in Draft P802.11be_D4.0.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -3375,6 +3391,9 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_BSS_DUMP_INCLUDE_USE_DATA,
 
+	NL80211_ATTR_MLO_TTLM_DLINK,
+	NL80211_ATTR_MLO_TTLM_ULINK,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,

net/wireless/nl80211.c

@@ -819,6 +819,8 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_EMA_RNR_ELEMS] = { .type = NLA_NESTED },
 	[NL80211_ATTR_MLO_LINK_DISABLED] = { .type = NLA_FLAG },
 	[NL80211_ATTR_BSS_DUMP_INCLUDE_USE_DATA] = { .type = NLA_FLAG },
+	[NL80211_ATTR_MLO_TTLM_DLINK] = NLA_POLICY_EXACT_LEN(sizeof(u16) * 8),
+	[NL80211_ATTR_MLO_TTLM_ULINK] = NLA_POLICY_EXACT_LEN(sizeof(u16) * 8),
 };
 
 /* policy for the key attributes */
@@ -16298,6 +16300,35 @@ static int nl80211_set_hw_timestamp(struct sk_buff *skb,
 	return rdev_set_hw_timestamp(rdev, dev, &hwts);
 }
 
+static int
+nl80211_set_ttlm(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_ttlm_params params = {};
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct net_device *dev = info->user_ptr[1];
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+	if (wdev->iftype != NL80211_IFTYPE_STATION &&
+	    wdev->iftype != NL80211_IFTYPE_P2P_CLIENT)
+		return -EOPNOTSUPP;
+
+	if (!wdev->connected)
+		return -ENOLINK;
+
+	if (!info->attrs[NL80211_ATTR_MLO_TTLM_DLINK] ||
+	    !info->attrs[NL80211_ATTR_MLO_TTLM_ULINK])
+		return -EINVAL;
+
+	nla_memcpy(params.dlink,
+		   info->attrs[NL80211_ATTR_MLO_TTLM_DLINK],
+		   sizeof(params.dlink));
+	nla_memcpy(params.ulink,
+		   info->attrs[NL80211_ATTR_MLO_TTLM_ULINK],
+		   sizeof(params.ulink));
+
+	return rdev_set_ttlm(rdev, dev, &params);
+}
+
 #define NL80211_FLAG_NEED_WIPHY		0x01
 #define NL80211_FLAG_NEED_NETDEV	0x02
 #define NL80211_FLAG_NEED_RTNL		0x04
@@ -17479,6 +17510,12 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.flags = GENL_UNS_ADMIN_PERM,
 		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP),
 	},
+	{
+		.cmd = NL80211_CMD_SET_TID_TO_LINK_MAPPING,
+		.doit = nl80211_set_ttlm,
+		.flags = GENL_UNS_ADMIN_PERM,
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP),
+	},
 };
 
 static struct genl_family nl80211_fam __ro_after_init = {

net/wireless/rdev-ops.h

@@ -1524,4 +1524,22 @@ rdev_set_hw_timestamp(struct cfg80211_registered_device *rdev,
 
 	return ret;
 }
+
+static inline int
+rdev_set_ttlm(struct cfg80211_registered_device *rdev,
+	      struct net_device *dev,
+	      struct cfg80211_ttlm_params *params)
+{
+	struct wiphy *wiphy = &rdev->wiphy;
+	int ret;
+
+	if (!rdev->ops->set_ttlm)
+		return -EOPNOTSUPP;
+
+	trace_rdev_set_ttlm(wiphy, dev, params);
+	ret = rdev->ops->set_ttlm(wiphy, dev, params);
+	trace_rdev_return_int(wiphy, ret);
+
+	return ret;
+}
 #endif /* __CFG80211_RDEV_OPS */

net/wireless/trace.h

@@ -3979,6 +3979,26 @@ TRACE_EVENT(cfg80211_links_removed,
 		  __entry->link_mask)
 );
 
+TRACE_EVENT(rdev_set_ttlm,
+	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
+		 struct cfg80211_ttlm_params *params),
+	TP_ARGS(wiphy, netdev, params),
+	TP_STRUCT__entry(
+		WIPHY_ENTRY
+		NETDEV_ENTRY
+		__array(u8, dlink, sizeof(u16) * 8)
+		__array(u8, ulink, sizeof(u16) * 8)
+	),
+	TP_fast_assign(
+		WIPHY_ASSIGN;
+		NETDEV_ASSIGN;
+		memcpy(__entry->dlink, params->dlink, sizeof(params->dlink));
+		memcpy(__entry->ulink, params->ulink, sizeof(params->ulink));
+	),
+	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT,
+		  WIPHY_PR_ARG, NETDEV_PR_ARG)
+);
+
 #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
 
 #undef TRACE_INCLUDE_PATH