sierra_net: Add support for IPv6 and Dual-Stack Link Sense Indications

If a context is configured as dualstack ("IPv4v6"), the modem indicates
the context activation with a slightly different indication message.
The dual-stack indication omits the link_type (IPv4/v6) and adds
additional address fields.
IPv6 LSIs are identical to IPv4 LSIs, but have a different link type.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/sierra_net.c

@@ -73,8 +73,6 @@ static	atomic_t iface_counter = ATOMIC_INIT(0);
 /* Private data structure */
 struct sierra_net_data {
 
-	u8 ethr_hdr_tmpl[ETH_HLEN]; /* ethernet header template for rx'd pkts */
-
 	u16 link_up;		/* air link up or down */
 	u8 tx_hdr_template[4];	/* part of HIP hdr for tx'd packets */
 
@@ -122,6 +120,7 @@ struct param {
 
 /* LSI Protocol types */
 #define SIERRA_NET_PROTOCOL_UMTS      0x01
+#define SIERRA_NET_PROTOCOL_UMTS_DS   0x04
 /* LSI Coverage */
 #define SIERRA_NET_COVERAGE_NONE      0x00
 #define SIERRA_NET_COVERAGE_NOPACKET  0x01
@@ -129,7 +128,8 @@ struct param {
 /* LSI Session */
 #define SIERRA_NET_SESSION_IDLE       0x00
 /* LSI Link types */
-#define SIERRA_NET_AS_LINK_TYPE_IPv4  0x00
+#define SIERRA_NET_AS_LINK_TYPE_IPV4  0x00
+#define SIERRA_NET_AS_LINK_TYPE_IPV6  0x02
 
 struct lsi_umts {
 	u8 protocol;
@@ -137,9 +137,14 @@ struct lsi_umts {
 	__be16 length;
 	/* eventually use a union for the rest - assume umts for now */
 	u8 coverage;
-	u8 unused2[41];
+	u8 network_len; /* network name len */
+	u8 network[40]; /* network name (UCS2, bigendian) */
 	u8 session_state;
 	u8 unused3[33];
+} __packed;
+
+struct lsi_umts_single {
+	struct lsi_umts lsi;
 	u8 link_type;
 	u8 pdp_addr_len; /* NW-supplied PDP address len */
 	u8 pdp_addr[16]; /* NW-supplied PDP address (bigendian)) */
@@ -158,10 +163,31 @@ struct lsi_umts {
 	u8 reserved[8];
 } __packed;
 
+struct lsi_umts_dual {
+	struct lsi_umts lsi;
+	u8 pdp_addr4_len; /* NW-supplied PDP IPv4 address len */
+	u8 pdp_addr4[4];  /* NW-supplied PDP IPv4 address (bigendian)) */
+	u8 pdp_addr6_len; /* NW-supplied PDP IPv6 address len */
+	u8 pdp_addr6[16]; /* NW-supplied PDP IPv6 address (bigendian)) */
+	u8 unused4[23];
+	u8 dns1_addr4_len; /* NW-supplied 1st DNS v4 address len (bigendian) */
+	u8 dns1_addr4[4];  /* NW-supplied 1st DNS v4 address */
+	u8 dns1_addr6_len; /* NW-supplied 1st DNS v6 address len */
+	u8 dns1_addr6[16]; /* NW-supplied 1st DNS v6 address (bigendian)*/
+	u8 dns2_addr4_len; /* NW-supplied 2nd DNS v4 address len (bigendian) */
+	u8 dns2_addr4[4];  /* NW-supplied 2nd DNS v4 address */
+	u8 dns2_addr6_len; /* NW-supplied 2nd DNS v6 address len */
+	u8 dns2_addr6[16]; /* NW-supplied 2nd DNS v6 address (bigendian)*/
+	u8 unused5[68];
+} __packed;
+
 #define SIERRA_NET_LSI_COMMON_LEN      4
-#define SIERRA_NET_LSI_UMTS_LEN        (sizeof(struct lsi_umts))
+#define SIERRA_NET_LSI_UMTS_LEN        (sizeof(struct lsi_umts_single))
 #define SIERRA_NET_LSI_UMTS_STATUS_LEN \
 	(SIERRA_NET_LSI_UMTS_LEN - SIERRA_NET_LSI_COMMON_LEN)
+#define SIERRA_NET_LSI_UMTS_DS_LEN     (sizeof(struct lsi_umts_dual))
+#define SIERRA_NET_LSI_UMTS_DS_STATUS_LEN \
+	(SIERRA_NET_LSI_UMTS_DS_LEN - SIERRA_NET_LSI_COMMON_LEN)
 
 /* Forward definitions */
 static void sierra_sync_timer(unsigned long syncdata);
@@ -190,10 +216,11 @@ static inline void sierra_net_set_private(struct usbnet *dev,
 	dev->data[0] = (unsigned long)priv;
 }
 
-/* is packet IPv4 */
+/* is packet IPv4/IPv6 */
 static inline int is_ip(struct sk_buff *skb)
 {
-	return skb->protocol == cpu_to_be16(ETH_P_IP);
+	return skb->protocol == cpu_to_be16(ETH_P_IP) ||
+	       skb->protocol == cpu_to_be16(ETH_P_IPV6);
 }
 
 /*
@@ -349,38 +376,43 @@ static inline int sierra_net_is_valid_addrlen(u8 len)
 static int sierra_net_parse_lsi(struct usbnet *dev, char *data, int datalen)
 {
 	struct lsi_umts *lsi = (struct lsi_umts *)data;
+	u32 expected_length;
 
-	if (datalen < sizeof(struct lsi_umts)) {
-		netdev_err(dev->net, "%s: Data length %d, exp %Zu\n",
-				__func__, datalen,
-				sizeof(struct lsi_umts));
+	if (datalen < sizeof(struct lsi_umts_single)) {
+		netdev_err(dev->net, "%s: Data length %d, exp >= %Zu\n",
+			   __func__, datalen, sizeof(struct lsi_umts_single));
 		return -1;
 	}
 
-	if (lsi->length != cpu_to_be16(SIERRA_NET_LSI_UMTS_STATUS_LEN)) {
-		netdev_err(dev->net, "%s: LSI_UMTS_STATUS_LEN %d, exp %u\n",
-				__func__, be16_to_cpu(lsi->length),
-				(u32)SIERRA_NET_LSI_UMTS_STATUS_LEN);
+	/* Validate the protocol  - only support UMTS for now */
+	if (lsi->protocol == SIERRA_NET_PROTOCOL_UMTS) {
+		struct lsi_umts_single *single = (struct lsi_umts_single *)lsi;
+
+		/* Validate the link type */
+		if (single->link_type != SIERRA_NET_AS_LINK_TYPE_IPV4 &&
+		    single->link_type != SIERRA_NET_AS_LINK_TYPE_IPV6) {
+			netdev_err(dev->net, "Link type unsupported: 0x%02x\n",
+				   single->link_type);
 			return -1;
 		}
-
-	/* Validate the protocol  - only support UMTS for now */
-	if (lsi->protocol != SIERRA_NET_PROTOCOL_UMTS) {
+		expected_length = SIERRA_NET_LSI_UMTS_STATUS_LEN;
+	} else if (lsi->protocol == SIERRA_NET_PROTOCOL_UMTS_DS) {
+		expected_length = SIERRA_NET_LSI_UMTS_DS_STATUS_LEN;
+	} else {
 		netdev_err(dev->net, "Protocol unsupported, 0x%02x\n",
 			   lsi->protocol);
 		return -1;
 	}
 
-	/* Validate the link type */
-	if (lsi->link_type != SIERRA_NET_AS_LINK_TYPE_IPv4) {
-		netdev_err(dev->net, "Link type unsupported: 0x%02x\n",
-			lsi->link_type);
+	if (be16_to_cpu(lsi->length) != expected_length) {
+		netdev_err(dev->net, "%s: LSI_UMTS_STATUS_LEN %d, exp %u\n",
+			   __func__, be16_to_cpu(lsi->length), expected_length);
 		return -1;
 	}
 
 	/* Validate the coverage */
-	if (lsi->coverage == SIERRA_NET_COVERAGE_NONE
-	   || lsi->coverage == SIERRA_NET_COVERAGE_NOPACKET) {
+	if (lsi->coverage == SIERRA_NET_COVERAGE_NONE ||
+	    lsi->coverage == SIERRA_NET_COVERAGE_NOPACKET) {
 		netdev_err(dev->net, "No coverage, 0x%02x\n", lsi->coverage);
 		return 0;
 	}
@@ -652,7 +684,6 @@ static int sierra_net_bind(struct usbnet *dev, struct usb_interface *intf)
 	u8	numendpoints;
 	u16	fwattr = 0;
 	int	status;
-	struct ethhdr *eth;
 	struct sierra_net_data *priv;
 	static const u8 sync_tmplate[sizeof(priv->sync_msg)] = {
 		0x00, 0x00, SIERRA_NET_HIP_MSYNC_ID, 0x00};
@@ -690,11 +721,6 @@ static int sierra_net_bind(struct usbnet *dev, struct usb_interface *intf)
 	dev->net->dev_addr[ETH_ALEN-2] = atomic_inc_return(&iface_counter);
 	dev->net->dev_addr[ETH_ALEN-1] = ifacenum;
 
-	/* we will have to manufacture ethernet headers, prepare template */
-	eth = (struct ethhdr *)priv->ethr_hdr_tmpl;
-	memcpy(&eth->h_dest, dev->net->dev_addr, ETH_ALEN);
-	eth->h_proto = cpu_to_be16(ETH_P_IP);
-
 	/* prepare shutdown message template */
 	memcpy(priv->shdwn_msg, shdwn_tmplate, sizeof(priv->shdwn_msg));
 	/* set context index initially to 0 - prepares tx hdr template */
@@ -824,9 +850,14 @@ static int sierra_net_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 
 		skb_pull(skb, hh.hdrlen);
 
-		/* We are going to accept this packet, prepare it */
-		memcpy(skb->data, sierra_net_get_private(dev)->ethr_hdr_tmpl,
-			ETH_HLEN);
+		/* We are going to accept this packet, prepare it.
+		 * In case protocol is IPv6, keep it, otherwise force IPv4.
+		 */
+		skb_reset_mac_header(skb);
+		if (eth_hdr(skb)->h_proto != cpu_to_be16(ETH_P_IPV6))
+			eth_hdr(skb)->h_proto = cpu_to_be16(ETH_P_IP);
+		eth_zero_addr(eth_hdr(skb)->h_source);
+		memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
 
 		/* Last packet in batch handled by usbnet */
 		if (hh.payload_len.word == skb->len)