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>

include/net/cfg80211.h

@@ -19,6 +19,7 @@
 #include <linux/nl80211.h>
 #include <linux/if_ether.h>
 #include <linux/ieee80211.h>
+#include <linux/net.h>
 #include <net/regulatory.h>
 
 /**
@@ -1587,6 +1588,41 @@ struct cfg80211_wowlan_trig_pkt_pattern {
 	int pkt_offset;
 };
 
+/**
+ * struct cfg80211_wowlan_tcp - TCP connection parameters
+ *
+ * @sock: (internal) socket for source port allocation
+ * @src: source IP address
+ * @dst: destination IP address
+ * @dst_mac: destination MAC address
+ * @src_port: source port
+ * @dst_port: destination port
+ * @payload_len: data payload length
+ * @payload: data payload buffer
+ * @payload_seq: payload sequence stamping configuration
+ * @data_interval: interval at which to send data packets
+ * @wake_len: wakeup payload match length
+ * @wake_data: wakeup payload match data
+ * @wake_mask: wakeup payload match mask
+ * @tokens_size: length of the tokens buffer
+ * @payload_tok: payload token usage configuration
+ */
+struct cfg80211_wowlan_tcp {
+	struct socket *sock;
+	__be32 src, dst;
+	u16 src_port, dst_port;
+	u8 dst_mac[ETH_ALEN];
+	int payload_len;
+	const u8 *payload;
+	struct nl80211_wowlan_tcp_data_seq payload_seq;
+	u32 data_interval;
+	u32 wake_len;
+	const u8 *wake_data, *wake_mask;
+	u32 tokens_size;
+	/* must be last, variable member */
+	struct nl80211_wowlan_tcp_data_token payload_tok;
+};
+
 /**
  * struct cfg80211_wowlan - Wake on Wireless-LAN support info
  *
@@ -1601,12 +1637,15 @@ struct cfg80211_wowlan_trig_pkt_pattern {
  * @eap_identity_req: wake up on EAP identity request packet
  * @four_way_handshake: wake up on 4-way handshake
  * @rfkill_release: wake up when rfkill is released
+ * @tcp: TCP connection establishment/wakeup parameters, see nl80211.h.
+ *	NULL if not configured.
  */
 struct cfg80211_wowlan {
 	bool any, disconnect, magic_pkt, gtk_rekey_failure,
 	     eap_identity_req, four_way_handshake,
 	     rfkill_release;
 	struct cfg80211_wowlan_trig_pkt_pattern *patterns;
+	struct cfg80211_wowlan_tcp *tcp;
 	int n_patterns;
 };
 
@@ -1626,11 +1665,15 @@ struct cfg80211_wowlan {
  *	frame triggers an 802.3 frame should be reported, for
  *	disconnect due to deauth 802.11 frame. This indicates which
  *	it is.
+ * @tcp_match: TCP wakeup packet received
+ * @tcp_connlost: TCP connection lost or failed to establish
+ * @tcp_nomoretokens: TCP data ran out of tokens
  */
 struct cfg80211_wowlan_wakeup {
 	bool disconnect, magic_pkt, gtk_rekey_failure,
 	     eap_identity_req, four_way_handshake,
-	     rfkill_release, packet_80211;
+	     rfkill_release, packet_80211,
+	     tcp_match, tcp_connlost, tcp_nomoretokens;
 	s32 pattern_idx;
 	u32 packet_present_len, packet_len;
 	const void *packet;
@@ -2285,6 +2328,14 @@ enum wiphy_wowlan_support_flags {
 	WIPHY_WOWLAN_RFKILL_RELEASE	= BIT(7),
 };
 
+struct wiphy_wowlan_tcp_support {
+	const struct nl80211_wowlan_tcp_data_token_feature *tok;
+	u32 data_payload_max;
+	u32 data_interval_max;
+	u32 wake_payload_max;
+	bool seq;
+};
+
 /**
  * struct wiphy_wowlan_support - WoWLAN support data
  * @flags: see &enum wiphy_wowlan_support_flags
@@ -2293,6 +2344,7 @@ enum wiphy_wowlan_support_flags {
  * @pattern_max_len: maximum length of each pattern
  * @pattern_min_len: minimum length of each pattern
  * @max_pkt_offset: maximum Rx packet offset
+ * @tcp: TCP wakeup support information
  */
 struct wiphy_wowlan_support {
 	u32 flags;
@@ -2300,6 +2352,7 @@ struct wiphy_wowlan_support {
 	int pattern_max_len;
 	int pattern_min_len;
 	int max_pkt_offset;
+	const struct wiphy_wowlan_tcp_support *tcp;
 };
 
 /**

include/uapi/linux/nl80211.h

@@ -2991,6 +2991,17 @@ struct nl80211_wowlan_pattern_support {
  * @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
  *
@@ -3012,12 +3023,126 @@ enum nl80211_wowlan_triggers {
 	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,
 	MAX_NL80211_WOWLAN_TRIG = NUM_NL80211_WOWLAN_TRIG - 1
 };
 
+/**
+ * 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)

net/wireless/core.h

@@ -108,6 +108,9 @@ cfg80211_rdev_free_wowlan(struct cfg80211_registered_device *rdev)
 	for (i = 0; i < rdev->wowlan->n_patterns; i++)
 		kfree(rdev->wowlan->patterns[i].mask);
 	kfree(rdev->wowlan->patterns);
+	if (rdev->wowlan->tcp && rdev->wowlan->tcp->sock)
+		sock_release(rdev->wowlan->tcp->sock);
+	kfree(rdev->wowlan->tcp);
 	kfree(rdev->wowlan);
 }