cfg80211: configuration for WoWLAN over TCP

Intel Wireless devices are able to make a TCP connection
after suspending, sending some data and waking up when
the connection receives wakeup data (or breaks). Add the
WoWLAN configuration and feature advertising API for it.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index eb7b322..5309b34 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2991,6 +2991,17 @@
  * @NL80211_WOWLAN_TRIG_WAKEUP_PKT_8023_LEN: Original length of the 802.3
  *	packet, may be bigger than the @NL80211_WOWLAN_TRIG_WAKEUP_PKT_8023
  *	attribute if the packet was truncated somewhere.
+ * @NL80211_WOWLAN_TRIG_TCP_CONNECTION: TCP connection wake, see DOC section
+ *	"TCP connection wakeup" for more details. This is a nested attribute
+ *	containing the exact information for establishing and keeping alive
+ *	the TCP connection.
+ * @NL80211_WOWLAN_TRIG_TCP_WAKEUP_MATCH: For wakeup reporting only, the
+ *	wakeup packet was received on the TCP connection
+ * @NL80211_WOWLAN_TRIG_WAKEUP_TCP_CONNLOST: For wakeup reporting only, the
+ *	TCP connection was lost or failed to be established
+ * @NL80211_WOWLAN_TRIG_WAKEUP_TCP_NOMORETOKENS: For wakeup reporting only,
+ *	the TCP connection ran out of tokens to use for data to send to the
+ *	service
  * @NUM_NL80211_WOWLAN_TRIG: number of wake on wireless triggers
  * @MAX_NL80211_WOWLAN_TRIG: highest wowlan trigger attribute number
  *
@@ -3012,6 +3023,10 @@
 	NL80211_WOWLAN_TRIG_WAKEUP_PKT_80211_LEN,
 	NL80211_WOWLAN_TRIG_WAKEUP_PKT_8023,
 	NL80211_WOWLAN_TRIG_WAKEUP_PKT_8023_LEN,
+	NL80211_WOWLAN_TRIG_TCP_CONNECTION,
+	NL80211_WOWLAN_TRIG_WAKEUP_TCP_MATCH,
+	NL80211_WOWLAN_TRIG_WAKEUP_TCP_CONNLOST,
+	NL80211_WOWLAN_TRIG_WAKEUP_TCP_NOMORETOKENS,
 
 	/* keep last */
 	NUM_NL80211_WOWLAN_TRIG,
@@ -3019,6 +3034,116 @@
 };
 
 /**
+ * DOC: TCP connection wakeup
+ *
+ * Some devices can establish a TCP connection in order to be woken up by a
+ * packet coming in from outside their network segment, or behind NAT. If
+ * configured, the device will establish a TCP connection to the given
+ * service, and periodically send data to that service. The first data
+ * packet is usually transmitted after SYN/ACK, also ACKing the SYN/ACK.
+ * The data packets can optionally include a (little endian) sequence
+ * number (in the TCP payload!) that is generated by the device, and, also
+ * optionally, a token from a list of tokens. This serves as a keep-alive
+ * with the service, and for NATed connections, etc.
+ *
+ * During this keep-alive period, the server doesn't send any data to the
+ * client. When receiving data, it is compared against the wakeup pattern
+ * (and mask) and if it matches, the host is woken up. Similarly, if the
+ * connection breaks or cannot be established to start with, the host is
+ * also woken up.
+ *
+ * Developer's note: ARP offload is required for this, otherwise TCP
+ * response packets might not go through correctly.
+ */
+
+/**
+ * struct nl80211_wowlan_tcp_data_seq - WoWLAN TCP data sequence
+ * @start: starting value
+ * @offset: offset of sequence number in packet
+ * @len: length of the sequence value to write, 1 through 4
+ *
+ * Note: don't confuse with the TCP sequence number(s), this is for the
+ * keepalive packet payload. The actual value is written into the packet
+ * in little endian.
+ */
+struct nl80211_wowlan_tcp_data_seq {
+	__u32 start, offset, len;
+};
+
+/**
+ * struct nl80211_wowlan_tcp_data_token - WoWLAN TCP data token config
+ * @offset: offset of token in packet
+ * @len: length of each token
+ * @token_stream: stream of data to be used for the tokens, the length must
+ *	be a multiple of @len for this to make sense
+ */
+struct nl80211_wowlan_tcp_data_token {
+	__u32 offset, len;
+	__u8 token_stream[];
+};
+
+/**
+ * struct nl80211_wowlan_tcp_data_token_feature - data token features
+ * @min_len: minimum token length
+ * @max_len: maximum token length
+ * @bufsize: total available token buffer size (max size of @token_stream)
+ */
+struct nl80211_wowlan_tcp_data_token_feature {
+	__u32 min_len, max_len, bufsize;
+};
+
+/**
+ * enum nl80211_wowlan_tcp_attrs - WoWLAN TCP connection parameters
+ * @__NL80211_WOWLAN_TCP_INVALID: invalid number for nested attributes
+ * @NL80211_WOWLAN_TCP_SRC_IPV4: source IPv4 address (in network byte order)
+ * @NL80211_WOWLAN_TCP_DST_IPV4: destination IPv4 address
+ *	(in network byte order)
+ * @NL80211_WOWLAN_TCP_DST_MAC: destination MAC address, this is given because
+ *	route lookup when configured might be invalid by the time we suspend,
+ *	and doing a route lookup when suspending is no longer possible as it
+ *	might require ARP querying.
+ * @NL80211_WOWLAN_TCP_SRC_PORT: source port (u16); optional, if not given a
+ *	socket and port will be allocated
+ * @NL80211_WOWLAN_TCP_DST_PORT: destination port (u16)
+ * @NL80211_WOWLAN_TCP_DATA_PAYLOAD: data packet payload, at least one byte.
+ *	For feature advertising, a u32 attribute holding the maximum length
+ *	of the data payload.
+ * @NL80211_WOWLAN_TCP_DATA_PAYLOAD_SEQ: data packet sequence configuration
+ *	(if desired), a &struct nl80211_wowlan_tcp_data_seq. For feature
+ *	advertising it is just a flag
+ * @NL80211_WOWLAN_TCP_DATA_PAYLOAD_TOKEN: data packet token configuration,
+ *	see &struct nl80211_wowlan_tcp_data_token and for advertising see
+ *	&struct nl80211_wowlan_tcp_data_token_feature.
+ * @NL80211_WOWLAN_TCP_DATA_INTERVAL: data interval in seconds, maximum
+ *	interval in feature advertising (u32)
+ * @NL80211_WOWLAN_TCP_WAKE_PAYLOAD: wake packet payload, for advertising a
+ *	u32 attribute holding the maximum length
+ * @NL80211_WOWLAN_TCP_WAKE_MASK: Wake packet payload mask, not used for
+ *	feature advertising. The mask works like @NL80211_WOWLAN_PKTPAT_MASK
+ *	but on the TCP payload only.
+ * @NUM_NL80211_WOWLAN_TCP: number of TCP attributes
+ * @MAX_NL80211_WOWLAN_TCP: highest attribute number
+ */
+enum nl80211_wowlan_tcp_attrs {
+	__NL80211_WOWLAN_TCP_INVALID,
+	NL80211_WOWLAN_TCP_SRC_IPV4,
+	NL80211_WOWLAN_TCP_DST_IPV4,
+	NL80211_WOWLAN_TCP_DST_MAC,
+	NL80211_WOWLAN_TCP_SRC_PORT,
+	NL80211_WOWLAN_TCP_DST_PORT,
+	NL80211_WOWLAN_TCP_DATA_PAYLOAD,
+	NL80211_WOWLAN_TCP_DATA_PAYLOAD_SEQ,
+	NL80211_WOWLAN_TCP_DATA_PAYLOAD_TOKEN,
+	NL80211_WOWLAN_TCP_DATA_INTERVAL,
+	NL80211_WOWLAN_TCP_WAKE_PAYLOAD,
+	NL80211_WOWLAN_TCP_WAKE_MASK,
+
+	/* keep last */
+	NUM_NL80211_WOWLAN_TCP,
+	MAX_NL80211_WOWLAN_TCP = NUM_NL80211_WOWLAN_TCP - 1
+};
+
+/**
  * enum nl80211_iface_limit_attrs - limit attributes
  * @NL80211_IFACE_LIMIT_UNSPEC: (reserved)
  * @NL80211_IFACE_LIMIT_MAX: maximum number of interfaces that