text: // SPDX-License-Identifier: GPL-2.0
  /* Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved. */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/etherdevice.h>
  #include <linux/ip.h>
  #include <linux/ipv6.h>
  #include <linux/udp.h>
  #include <linux/in.h>
  #include <linux/if_arp.h>
  #include <linux/if_ether.h>
  #include <linux/if_vlan.h>
  #include <linux/in6.h>
  #include <linux/tcp.h>
  #include <linux/icmp.h>
  #include <linux/icmpv6.h>
  #include <linux/uaccess.h>
  #include <linux/errno.h>
  #include <net/ndisc.h>
  
  #include "gdm_lte.h"
  #include "netlink_k.h"
  #include "hci.h"
  #include "hci_packet.h"
  #include "gdm_endian.h"
  
  /*
   * Netlink protocol number
   */
  #define NETLINK_LTE 30
  
  /*
   * Default MTU Size
   */
  #define DEFAULT_MTU_SIZE 1500
  
  #define IP_VERSION_4	4
  #define IP_VERSION_6	6
  
  static struct {
  	int ref_cnt;
  	struct sock *sock;
  } lte_event;
  
  static struct device_type wwan_type = {
  	.name   = "wwan",
  };
  
  static int gdm_lte_open(struct net_device *dev)
  {
  	netif_start_queue(dev);
  	return 0;
  }
  
  static int gdm_lte_close(struct net_device *dev)
  {
  	netif_stop_queue(dev);
  	return 0;
  }
  
  static int gdm_lte_set_config(struct net_device *dev, struct ifmap *map)
  {
  	if (dev->flags & IFF_UP)
  		return -EBUSY;
  	return 0;
  }
  
  static void tx_complete(void *arg)
  {
  	struct nic *nic = arg;
  
  	if (netif_queue_stopped(nic->netdev))
  		netif_wake_queue(nic->netdev);
  }
  
  static int gdm_lte_rx(struct sk_buff *skb, struct nic *nic, int nic_type)
  {
  	int ret;
  
  	ret = netif_rx_ni(skb);
  	if (ret == NET_RX_DROP) {
  		nic->stats.rx_dropped++;
  	} else {
  		nic->stats.rx_packets++;
  		nic->stats.rx_bytes += skb->len + ETH_HLEN;
  	}
  
  	return 0;
  }
  
  static int gdm_lte_emulate_arp(struct sk_buff *skb_in, u32 nic_type)
  {
  	struct nic *nic = netdev_priv(skb_in->dev);
  	struct sk_buff *skb_out;
  	struct ethhdr eth;
  	struct vlan_ethhdr vlan_eth;
  	struct arphdr *arp_in;
  	struct arphdr *arp_out;
  	struct arpdata {
  		u8 ar_sha[ETH_ALEN];
  		u8 ar_sip[4];
  		u8 ar_tha[ETH_ALEN];
  		u8 ar_tip[4];
  	};
  	struct arpdata *arp_data_in;
  	struct arpdata *arp_data_out;
  	u8 arp_temp[60];
  	void *mac_header_data;
  	u32 mac_header_len;
  
  	/* Check for skb->len, discard if empty */
  	if (skb_in->len == 0)
  		return -ENODATA;
  
  	/* Format the mac header so that it can be put to skb */
  	if (ntohs(((struct ethhdr *)skb_in->data)->h_proto) == ETH_P_8021Q) {
  		memcpy(&vlan_eth, skb_in->data, sizeof(struct vlan_ethhdr));
  		mac_header_data = &vlan_eth;
  		mac_header_len = VLAN_ETH_HLEN;
  	} else {
  		memcpy(&eth, skb_in->data, sizeof(struct ethhdr));
  		mac_header_data = &eth;
  		mac_header_len = ETH_HLEN;
  	}
  
  	/* Get the pointer of the original request */
  	arp_in = (struct arphdr *)(skb_in->data + mac_header_len);
  	arp_data_in = (struct arpdata *)(skb_in->data + mac_header_len +
  					sizeof(struct arphdr));
  
  	/* Get the pointer of the outgoing response */
  	arp_out = (struct arphdr *)arp_temp;
  	arp_data_out = (struct arpdata *)(arp_temp + sizeof(struct arphdr));
  
  	/* Copy the arp header */
  	memcpy(arp_out, arp_in, sizeof(struct arphdr));
  	arp_out->ar_op = htons(ARPOP_REPLY);
  
  	/* Copy the arp payload: based on 2 bytes of mac and fill the IP */
  	arp_data_out->ar_sha[0] = arp_data_in->ar_sha[0];
  	arp_data_out->ar_sha[1] = arp_data_in->ar_sha[1];
  	memcpy(&arp_data_out->ar_sha[2], &arp_data_in->ar_tip[0], 4);
  	memcpy(&arp_data_out->ar_sip[0], &arp_data_in->ar_tip[0], 4);
  	memcpy(&arp_data_out->ar_tha[0], &arp_data_in->ar_sha[0], 6);
  	memcpy(&arp_data_out->ar_tip[0], &arp_data_in->ar_sip[0], 4);
  
  	/* Fill the destination mac with source mac of the received packet */
  	memcpy(mac_header_data, mac_header_data + ETH_ALEN, ETH_ALEN);
  	/* Fill the source mac with nic's source mac */
  	memcpy(mac_header_data + ETH_ALEN, nic->src_mac_addr, ETH_ALEN);
  
  	/* Alloc skb and reserve align */
  	skb_out = dev_alloc_skb(skb_in->len);
  	if (!skb_out)
  		return -ENOMEM;
  	skb_reserve(skb_out, NET_IP_ALIGN);
  
  	skb_put_data(skb_out, mac_header_data, mac_header_len);
  	skb_put_data(skb_out, arp_out, sizeof(struct arphdr));
  	skb_put_data(skb_out, arp_data_out, sizeof(struct arpdata));
  
  	skb_out->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
  	skb_out->dev = skb_in->dev;
  	skb_reset_mac_header(skb_out);
  	skb_pull(skb_out, ETH_HLEN);
  
  	gdm_lte_rx(skb_out, nic, nic_type);
  
  	return 0;
  }
  
  static __sum16 icmp6_checksum(struct ipv6hdr *ipv6, u16 *ptr, int len)
  {
  	unsigned short *w = ptr;
  	__wsum sum = 0;
  	int i;
  	u16 pa;
  
  	union {
  		struct {
  			u8 ph_src[16];
  			u8 ph_dst[16];
  			u32 ph_len;
  			u8 ph_zero[3];
  			u8 ph_nxt;
  		} ph __packed;
  		u16 pa[20];
  	} pseudo_header;
  
  	memset(&pseudo_header, 0, sizeof(pseudo_header));
  	memcpy(&pseudo_header.ph.ph_src, &ipv6->saddr.in6_u.u6_addr8, 16);
  	memcpy(&pseudo_header.ph.ph_dst, &ipv6->daddr.in6_u.u6_addr8, 16);
  	pseudo_header.ph.ph_len = be16_to_cpu(ipv6->payload_len);
  	pseudo_header.ph.ph_nxt = ipv6->nexthdr;
  
  	w = (u16 *)&pseudo_header;
  	for (i = 0; i < ARRAY_SIZE(pseudo_header.pa); i++) {
  		pa = pseudo_header.pa[i];
  		sum = csum_add(sum, csum_unfold((__force __sum16)pa));
  	}
  
  	w = ptr;
  	while (len > 1) {
  		sum = csum_add(sum, csum_unfold((__force __sum16)*w++));
  		len -= 2;
  	}
  
  	return csum_fold(sum);
  }
  
  static int gdm_lte_emulate_ndp(struct sk_buff *skb_in, u32 nic_type)
  {
  	struct nic *nic = netdev_priv(skb_in->dev);
  	struct sk_buff *skb_out;
  	struct ethhdr eth;
  	struct vlan_ethhdr vlan_eth;
  	struct neighbour_advertisement {
  		u8 target_address[16];
  		u8 type;
  		u8 length;
  		u8 link_layer_address[6];
  	};
  	struct neighbour_advertisement na;
  	struct neighbour_solicitation {
  		u8 target_address[16];
  	};
  	struct neighbour_solicitation *ns;
  	struct ipv6hdr *ipv6_in;
  	struct ipv6hdr ipv6_out;
  	struct icmp6hdr *icmp6_in;
  	struct icmp6hdr icmp6_out;
  
  	void *mac_header_data;
  	u32 mac_header_len;
  
  	/* Format the mac header so that it can be put to skb */
  	if (ntohs(((struct ethhdr *)skb_in->data)->h_proto) == ETH_P_8021Q) {
  		memcpy(&vlan_eth, skb_in->data, sizeof(struct vlan_ethhdr));
  		if (ntohs(vlan_eth.h_vlan_encapsulated_proto) != ETH_P_IPV6)
  			return -EPROTONOSUPPORT;
  		mac_header_data = &vlan_eth;
  		mac_header_len = VLAN_ETH_HLEN;
  	} else {
  		memcpy(&eth, skb_in->data, sizeof(struct ethhdr));
  		if (ntohs(eth.h_proto) != ETH_P_IPV6)
  			return -EPROTONOSUPPORT;
  		mac_header_data = &eth;
  		mac_header_len = ETH_HLEN;
  	}
  
  	/* Check if this is IPv6 ICMP packet */
  	ipv6_in = (struct ipv6hdr *)(skb_in->data + mac_header_len);
  	if (ipv6_in->version != 6 || ipv6_in->nexthdr != IPPROTO_ICMPV6)
  		return -EPROTONOSUPPORT;
  
  	/* Check if this is NDP packet */
  	icmp6_in = (struct icmp6hdr *)(skb_in->data + mac_header_len +
  					sizeof(struct ipv6hdr));
  	if (icmp6_in->icmp6_type == NDISC_ROUTER_SOLICITATION) { /* Check RS */
  		return -EPROTONOSUPPORT;
  	} else if (icmp6_in->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
  		/* Check NS */
  		u8 icmp_na[sizeof(struct icmp6hdr) +
  			sizeof(struct neighbour_advertisement)];
  		u8 zero_addr8[16] = {0,};
  
  		if (memcmp(ipv6_in->saddr.in6_u.u6_addr8, zero_addr8, 16) == 0)
  			/* Duplicate Address Detection: Source IP is all zero */
  			return 0;
  
  		icmp6_out.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
  		icmp6_out.icmp6_code = 0;
  		icmp6_out.icmp6_cksum = 0;
  		/* R=0, S=1, O=1 */
  		icmp6_out.icmp6_dataun.un_data32[0] = htonl(0x60000000);
  
  		ns = (struct neighbour_solicitation *)
  			(skb_in->data + mac_header_len +
  			 sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr));
  		memcpy(&na.target_address, ns->target_address, 16);
  		na.type = 0x02;
  		na.length = 1;
  		na.link_layer_address[0] = 0x00;
  		na.link_layer_address[1] = 0x0a;
  		na.link_layer_address[2] = 0x3b;
  		na.link_layer_address[3] = 0xaf;
  		na.link_layer_address[4] = 0x63;
  		na.link_layer_address[5] = 0xc7;
  
  		memcpy(&ipv6_out, ipv6_in, sizeof(struct ipv6hdr));
  		memcpy(ipv6_out.saddr.in6_u.u6_addr8, &na.target_address, 16);
  		memcpy(ipv6_out.daddr.in6_u.u6_addr8,
  		       ipv6_in->saddr.in6_u.u6_addr8, 16);
  		ipv6_out.payload_len = htons(sizeof(struct icmp6hdr) +
  				sizeof(struct neighbour_advertisement));
  
  		memcpy(icmp_na, &icmp6_out, sizeof(struct icmp6hdr));
  		memcpy(icmp_na + sizeof(struct icmp6hdr), &na,
  		       sizeof(struct neighbour_advertisement));
  
  		icmp6_out.icmp6_cksum = icmp6_checksum(&ipv6_out,
  						       (u16 *)icmp_na,
  						       sizeof(icmp_na));
  	} else {
  		return -EINVAL;
  	}
  
  	/* Fill the destination mac with source mac of the received packet */
  	memcpy(mac_header_data, mac_header_data + ETH_ALEN, ETH_ALEN);
  	/* Fill the source mac with nic's source mac */
  	memcpy(mac_header_data + ETH_ALEN, nic->src_mac_addr, ETH_ALEN);
  
  	/* Alloc skb and reserve align */
  	skb_out = dev_alloc_skb(skb_in->len);
  	if (!skb_out)
  		return -ENOMEM;
  	skb_reserve(skb_out, NET_IP_ALIGN);
  
  	skb_put_data(skb_out, mac_header_data, mac_header_len);
  	skb_put_data(skb_out, &ipv6_out, sizeof(struct ipv6hdr));
  	skb_put_data(skb_out, &icmp6_out, sizeof(struct icmp6hdr));
  	skb_put_data(skb_out, &na, sizeof(struct neighbour_advertisement));
  
  	skb_out->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
  	skb_out->dev = skb_in->dev;
  	skb_reset_mac_header(skb_out);
  	skb_pull(skb_out, ETH_HLEN);
  
  	gdm_lte_rx(skb_out, nic, nic_type);
  
  	return 0;
  }
  
  static s32 gdm_lte_tx_nic_type(struct net_device *dev, struct sk_buff *skb)
  {
  	struct nic *nic = netdev_priv(dev);
  	struct ethhdr *eth;
  	struct vlan_ethhdr *vlan_eth;
  	struct iphdr *ip;
  	struct ipv6hdr *ipv6;
  	int mac_proto;
  	void *network_data;
  	u32 nic_type;
  
  	/* NIC TYPE is based on the nic_id of this net_device */
  	nic_type = 0x00000010 | nic->nic_id;
  
  	/* Get ethernet protocol */
  	eth = (struct ethhdr *)skb->data;
  	if (ntohs(eth->h_proto) == ETH_P_8021Q) {
  		vlan_eth = (struct vlan_ethhdr *)skb->data;
  		mac_proto = ntohs(vlan_eth->h_vlan_encapsulated_proto);
  		network_data = skb->data + VLAN_ETH_HLEN;
  		nic_type |= NIC_TYPE_F_VLAN;
  	} else {
  		mac_proto = ntohs(eth->h_proto);
  		network_data = skb->data + ETH_HLEN;
  	}
  
  	/* Process packet for nic type */
  	switch (mac_proto) {
  	case ETH_P_ARP:
  		nic_type |= NIC_TYPE_ARP;
  		break;
  	case ETH_P_IP:
  		nic_type |= NIC_TYPE_F_IPV4;
  		ip = network_data;
  
  		/* Check DHCPv4 */
  		if (ip->protocol == IPPROTO_UDP) {
  			struct udphdr *udp =
  					network_data + sizeof(struct iphdr);
  			if (ntohs(udp->dest) == 67 || ntohs(udp->dest) == 68)
  				nic_type |= NIC_TYPE_F_DHCP;
  		}
  		break;
  	case ETH_P_IPV6:
  		nic_type |= NIC_TYPE_F_IPV6;
  		ipv6 = network_data;
  
  		if (ipv6->nexthdr == IPPROTO_ICMPV6) /* Check NDP request */ {
  			struct icmp6hdr *icmp6 =
  					network_data + sizeof(struct ipv6hdr);
  			if (icmp6->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION)
  				nic_type |= NIC_TYPE_ICMPV6;
  		} else if (ipv6->nexthdr == IPPROTO_UDP) /* Check DHCPv6 */ {
  			struct udphdr *udp =
  					network_data + sizeof(struct ipv6hdr);
  			if (ntohs(udp->dest) == 546 || ntohs(udp->dest) == 547)
  				nic_type |= NIC_TYPE_F_DHCP;
  		}
  		break;
  	default:
  		break;
  	}
  
  	return nic_type;
  }
  
  static netdev_tx_t gdm_lte_tx(struct sk_buff *skb, struct net_device *dev)
  {
  	struct nic *nic = netdev_priv(dev);
  	u32 nic_type;
  	void *data_buf;
  	int data_len;
  	int idx;
  	int ret = 0;
  
  	nic_type = gdm_lte_tx_nic_type(dev, skb);
  	if (nic_type == 0) {
  		netdev_err(dev, "tx - invalid nic_type\n");
  		return -EMEDIUMTYPE;
  	}
  
  	if (nic_type & NIC_TYPE_ARP) {
  		if (gdm_lte_emulate_arp(skb, nic_type) == 0) {
  			dev_kfree_skb(skb);
  			return 0;
  		}
  	}
  
  	if (nic_type & NIC_TYPE_ICMPV6) {
  		if (gdm_lte_emulate_ndp(skb, nic_type) == 0) {
  			dev_kfree_skb(skb);
  			return 0;
  		}
  	}
  
  	/*
  	 * Need byte shift (that is, remove VLAN tag) if there is one
  	 * For the case of ARP, this breaks the offset as vlan_ethhdr+4
  	 * is treated as ethhdr	However, it shouldn't be a problem as
  	 * the response starts from arp_hdr and ethhdr is created by this
  	 * driver based on the NIC mac
  	 */
  	if (nic_type & NIC_TYPE_F_VLAN) {
  		struct vlan_ethhdr *vlan_eth = (struct vlan_ethhdr *)skb->data;
  
  		nic->vlan_id = ntohs(vlan_eth->h_vlan_TCI) & VLAN_VID_MASK;
  		data_buf = skb->data + (VLAN_ETH_HLEN - ETH_HLEN);
  		data_len = skb->len - (VLAN_ETH_HLEN - ETH_HLEN);
  	} else {
  		nic->vlan_id = 0;
  		data_buf = skb->data;
  		data_len = skb->len;
  	}
  
  	/* If it is a ICMPV6 packet, clear all the other bits :
  	 * for backward compatibility with the firmware
  	 */
  	if (nic_type & NIC_TYPE_ICMPV6)
  		nic_type = NIC_TYPE_ICMPV6;
  
  	/* If it is not a dhcp packet, clear all the flag bits :
  	 * original NIC, otherwise the special flag (IPVX | DHCP)
  	 */
  	if (!(nic_type & NIC_TYPE_F_DHCP))
  		nic_type &= NIC_TYPE_MASK;
  
  	ret = sscanf(dev->name, "lte%d", &idx);
  	if (ret != 1) {
  		dev_kfree_skb(skb);
  		return -EINVAL;
  	}
  
  	ret = nic->phy_dev->send_sdu_func(nic->phy_dev->priv_dev,
  					  data_buf, data_len,
  					  nic->pdn_table.dft_eps_id, 0,
  					  tx_complete, nic, idx,
  					  nic_type);
  
  	if (ret == TX_NO_BUFFER || ret == TX_NO_SPC) {
  		netif_stop_queue(dev);
  		if (ret == TX_NO_BUFFER)
  			ret = 0;
  		else
  			ret = -ENOSPC;
  	} else if (ret == TX_NO_DEV) {
  		ret = -ENODEV;
  	}
  
  	/* Updates tx stats */
  	if (ret) {
  		nic->stats.tx_dropped++;
  	} else {
  		nic->stats.tx_packets++;
  		nic->stats.tx_bytes += data_len;
  	}
  	dev_kfree_skb(skb);
  
  	return 0;
  }
  
  static struct net_device_stats *gdm_lte_stats(struct net_device *dev)
  {
  	struct nic *nic = netdev_priv(dev);
  
  	return &nic->stats;
  }
  
  static int gdm_lte_event_send(struct net_device *dev, char *buf, int len)
  {
  	struct phy_dev *phy_dev = ((struct nic *)netdev_priv(dev))->phy_dev;
  	struct hci_packet *hci = (struct hci_packet *)buf;
  	int length;
  	int idx;
  	int ret;
  
  	ret = sscanf(dev->name, "lte%d", &idx);
  	if (ret != 1)
  		return -EINVAL;
  
  	length = gdm_dev16_to_cpu(phy_dev->get_endian(phy_dev->priv_dev),
  				  hci->len) + HCI_HEADER_SIZE;
  	return netlink_send(lte_event.sock, idx, 0, buf, length, dev);
  }
  
  static void gdm_lte_event_rcv(struct net_device *dev, u16 type,
  			      void *msg, int len)
  {
  	struct nic *nic = netdev_priv(dev);
  
  	nic->phy_dev->send_hci_func(nic->phy_dev->priv_dev, msg, len, NULL,
  				    NULL);
  }
  
  int gdm_lte_event_init(void)
  {
  	if (lte_event.ref_cnt == 0)
  		lte_event.sock = netlink_init(NETLINK_LTE, gdm_lte_event_rcv);
  
  	if (lte_event.sock) {
  		lte_event.ref_cnt++;
  		return 0;
  	}
  
  	pr_err("event init failed\n");
  	return -ENODATA;
  }
  
  void gdm_lte_event_exit(void)
  {
  	if (lte_event.sock && --lte_event.ref_cnt == 0) {
  		sock_release(lte_event.sock->sk_socket);
  		lte_event.sock = NULL;
  	}
  }
  
  static int find_dev_index(u32 nic_type)
  {
  	u8 index;
  
  	index = (u8)(nic_type & 0x0000000f);
  	if (index >= MAX_NIC_TYPE)
  		return -EINVAL;
  
  	return index;
  }
  
  static void gdm_lte_netif_rx(struct net_device *dev, char *buf,
  			     int len, int flagged_nic_type)
  {
  	u32 nic_type;
  	struct nic *nic;
  	struct sk_buff *skb;
  	struct ethhdr eth;
  	struct vlan_ethhdr vlan_eth;
  	void *mac_header_data;
  	u32 mac_header_len;
  	char ip_version = 0;
  
  	nic_type = flagged_nic_type & NIC_TYPE_MASK;
  	nic = netdev_priv(dev);
  
  	if (flagged_nic_type & NIC_TYPE_F_DHCP) {
  		/* Change the destination mac address
  		 * with the one requested the IP
  		 */
  		if (flagged_nic_type & NIC_TYPE_F_IPV4) {
  			struct dhcp_packet {
  				u8 op;      /* BOOTREQUEST or BOOTREPLY */
  				u8 htype;   /* hardware address type.
  					     * 1 = 10mb ethernet
  					     */
  				u8 hlen;    /* hardware address length */
  				u8 hops;    /* used by relay agents only */
  				u32 xid;    /* unique id */
  				u16 secs;   /* elapsed since client began
  					     * acquisition/renewal
  					     */
  				u16 flags;  /* only one flag so far: */
  				#define BROADCAST_FLAG 0x8000
  				/* "I need broadcast replies" */
  				u32 ciaddr; /* client IP (if client is in
  					     * BOUND, RENEW or REBINDING state)
  					     */
  				u32 yiaddr; /* 'your' (client) IP address */
  				/* IP address of next server to use in
  				 * bootstrap, returned in DHCPOFFER,
  				 * DHCPACK by server
  				 */
  				u32 siaddr_nip;
  				u32 gateway_nip; /* relay agent IP address */
  				u8 chaddr[16];   /* link-layer client hardware
  						  * address (MAC)
  						  */
  				u8 sname[64];    /* server host name (ASCIZ) */
  				u8 file[128];    /* boot file name (ASCIZ) */
  				u32 cookie;      /* fixed first four option
  						  * bytes (99,130,83,99 dec)
  						  */
  			} __packed;
  			void *addr = buf + sizeof(struct iphdr) +
  				sizeof(struct udphdr) +
  				offsetof(struct dhcp_packet, chaddr);
  			ether_addr_copy(nic->dest_mac_addr, addr);
  		}
  	}
  
  	if (nic->vlan_id > 0) {
  		mac_header_data = (void *)&vlan_eth;
  		mac_header_len = VLAN_ETH_HLEN;
  	} else {
  		mac_header_data = (void *)&eth;
  		mac_header_len = ETH_HLEN;
  	}
  
  	/* Format the data so that it can be put to skb */
  	ether_addr_copy(mac_header_data, nic->dest_mac_addr);
  	memcpy(mac_header_data + ETH_ALEN, nic->src_mac_addr, ETH_ALEN);
  
  	vlan_eth.h_vlan_TCI = htons(nic->vlan_id);
  	vlan_eth.h_vlan_proto = htons(ETH_P_8021Q);
  
  	if (nic_type == NIC_TYPE_ARP) {
  		/* Should be response: Only happens because
  		 * there was a request from the host
  		 */
  		eth.h_proto = htons(ETH_P_ARP);
  		vlan_eth.h_vlan_encapsulated_proto = htons(ETH_P_ARP);
  	} else {
  		ip_version = buf[0] >> 4;
  		if (ip_version == IP_VERSION_4) {
  			eth.h_proto = htons(ETH_P_IP);
  			vlan_eth.h_vlan_encapsulated_proto = htons(ETH_P_IP);
  		} else if (ip_version == IP_VERSION_6) {
  			eth.h_proto = htons(ETH_P_IPV6);
  			vlan_eth.h_vlan_encapsulated_proto = htons(ETH_P_IPV6);
  		} else {
  			netdev_err(dev, "Unknown IP version %d\n", ip_version);
  			return;
  		}
  	}
  
  	/* Alloc skb and reserve align */
  	skb = dev_alloc_skb(len + mac_header_len + NET_IP_ALIGN);
  	if (!skb)
  		return;
  	skb_reserve(skb, NET_IP_ALIGN);
  
  	skb_put_data(skb, mac_header_data, mac_header_len);
  	skb_put_data(skb, buf, len);
  
  	skb->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
  	skb->dev = dev;
  	skb_reset_mac_header(skb);
  	skb_pull(skb, ETH_HLEN);
  
  	gdm_lte_rx(skb, nic, nic_type);
  }
  
  static void gdm_lte_multi_sdu_pkt(struct phy_dev *phy_dev, char *buf, int len)
  {
  	struct net_device *dev;
  	struct multi_sdu *multi_sdu = (struct multi_sdu *)buf;
  	struct sdu *sdu = NULL;
  	u8 endian = phy_dev->get_endian(phy_dev->priv_dev);
  	u8 *data = (u8 *)multi_sdu->data;
  	u16 i = 0;
  	u16 num_packet;
  	u16 hci_len;
  	u16 cmd_evt;
  	u32 nic_type;
  	int index;
  
  	hci_len = gdm_dev16_to_cpu(endian, multi_sdu->len);
  	num_packet = gdm_dev16_to_cpu(endian, multi_sdu->num_packet);
  
  	for (i = 0; i < num_packet; i++) {
  		sdu = (struct sdu *)data;
  
  		cmd_evt  = gdm_dev16_to_cpu(endian, sdu->cmd_evt);
  		hci_len  = gdm_dev16_to_cpu(endian, sdu->len);
  		nic_type = gdm_dev32_to_cpu(endian, sdu->nic_type);
  
  		if (cmd_evt != LTE_RX_SDU) {
  			pr_err("rx sdu wrong hci %04x\n", cmd_evt);
  			return;
  		}
  		if (hci_len < 12) {
  			pr_err("rx sdu invalid len %d\n", hci_len);
  			return;
  		}
  
  		index = find_dev_index(nic_type);
  		if (index < 0) {
  			pr_err("rx sdu invalid nic_type :%x\n", nic_type);
  			return;
  		}
  		dev = phy_dev->dev[index];
  		gdm_lte_netif_rx(dev, (char *)sdu->data,
  				 (int)(hci_len - 12), nic_type);
  
  		data += ((hci_len + 3) & 0xfffc) + HCI_HEADER_SIZE;
  	}
  }
  
  static void gdm_lte_pdn_table(struct net_device *dev, char *buf, int len)
  {
  	struct nic *nic = netdev_priv(dev);
  	struct hci_pdn_table_ind *pdn_table = (struct hci_pdn_table_ind *)buf;
  	u8 ed = nic->phy_dev->get_endian(nic->phy_dev->priv_dev);
  
  	if (!pdn_table->activate) {
  		memset(&nic->pdn_table, 0x00, sizeof(struct pdn_table));
  		netdev_info(dev, "pdn deactivated\n");
  
  		return;
  	}
  
  	nic->pdn_table.activate = pdn_table->activate;
  	nic->pdn_table.dft_eps_id = gdm_dev32_to_cpu(ed, pdn_table->dft_eps_id);
  	nic->pdn_table.nic_type = gdm_dev32_to_cpu(ed, pdn_table->nic_type);
  
  	netdev_info(dev, "pdn activated, nic_type=0x%x\n",
  		    nic->pdn_table.nic_type);
  }
  
  static int gdm_lte_receive_pkt(struct phy_dev *phy_dev, char *buf, int len)
  {
  	struct hci_packet *hci = (struct hci_packet *)buf;
  	struct hci_pdn_table_ind *pdn_table = (struct hci_pdn_table_ind *)buf;
  	struct sdu *sdu;
  	struct net_device *dev;
  	u8 endian = phy_dev->get_endian(phy_dev->priv_dev);
  	int ret = 0;
  	u16 cmd_evt;
  	u32 nic_type;
  	int index;
  
  	if (!len)
  		return ret;
  
  	cmd_evt = gdm_dev16_to_cpu(endian, hci->cmd_evt);
  
  	dev = phy_dev->dev[0];
  	if (!dev)
  		return 0;
  
  	switch (cmd_evt) {
  	case LTE_RX_SDU:
  		sdu = (struct sdu *)hci->data;
  		nic_type = gdm_dev32_to_cpu(endian, sdu->nic_type);
  		index = find_dev_index(nic_type);
  		if (index < 0)
  			return index;
  		dev = phy_dev->dev[index];
  		gdm_lte_netif_rx(dev, hci->data, len, nic_type);
  		break;
  	case LTE_RX_MULTI_SDU:
  		gdm_lte_multi_sdu_pkt(phy_dev, buf, len);
  		break;
  	case LTE_LINK_ON_OFF_INDICATION:
  		netdev_info(dev, "link %s\n",
  			    ((struct hci_connect_ind *)buf)->connect
  			    ? "on" : "off");
  		break;
  	case LTE_PDN_TABLE_IND:
  		pdn_table = (struct hci_pdn_table_ind *)buf;
  		nic_type = gdm_dev32_to_cpu(endian, pdn_table->nic_type);
  		index = find_dev_index(nic_type);
  		if (index < 0)
  			return index;
  		dev = phy_dev->dev[index];
  		gdm_lte_pdn_table(dev, buf, len);
  		/* Fall through */
  	default:
  		ret = gdm_lte_event_send(dev, buf, len);
  		break;
  	}
  
  	return ret;
  }
  
  static int rx_complete(void *arg, void *data, int len, int context)
  {
  	struct phy_dev *phy_dev = arg;
  
  	return gdm_lte_receive_pkt(phy_dev, data, len);
  }
  
  void start_rx_proc(struct phy_dev *phy_dev)
  {
  	int i;
  
  	for (i = 0; i < MAX_RX_SUBMIT_COUNT; i++)
  		phy_dev->rcv_func(phy_dev->priv_dev,
  				rx_complete, phy_dev, USB_COMPLETE);
  }
  
  static const struct net_device_ops gdm_netdev_ops = {
  	.ndo_open			= gdm_lte_open,
  	.ndo_stop			= gdm_lte_close,
  	.ndo_set_config			= gdm_lte_set_config,
  	.ndo_start_xmit			= gdm_lte_tx,
  	.ndo_get_stats			= gdm_lte_stats,
  };
  
  static u8 gdm_lte_macaddr[ETH_ALEN] = {0x00, 0x0a, 0x3b, 0x00, 0x00, 0x00};
  
  static void form_mac_address(u8 *dev_addr, u8 *nic_src, u8 *nic_dest,
  			     u8 *mac_address, u8 index)
  {
  	/* Form the dev_addr */
  	if (!mac_address)
  		ether_addr_copy(dev_addr, gdm_lte_macaddr);
  	else
  		ether_addr_copy(dev_addr, mac_address);
  
  	/* The last byte of the mac address
  	 * should be less than or equal to 0xFC
  	 */
  	dev_addr[ETH_ALEN - 1] += index;
  
  	/* Create random nic src and copy the first
  	 * 3 bytes to be the same as dev_addr
  	 */
  	eth_random_addr(nic_src);
  	memcpy(nic_src, dev_addr, 3);
  
  	/* Copy the nic_dest from dev_addr*/
  	ether_addr_copy(nic_dest, dev_addr);
  }
  
  static void validate_mac_address(u8 *mac_address)
  {
  	/* if zero address or multicast bit set, restore the default value */
  	if (is_zero_ether_addr(mac_address) || (mac_address[0] & 0x01)) {
  		pr_err("MAC invalid, restoring default\n");
  		memcpy(mac_address, gdm_lte_macaddr, 6);
  	}
  }
  
  int register_lte_device(struct phy_dev *phy_dev,
  			struct device *dev, u8 *mac_address)
  {
  	struct nic *nic;
  	struct net_device *net;
  	char pdn_dev_name[16];
  	int ret = 0;
  	u8 index;
  
  	validate_mac_address(mac_address);
  
  	for (index = 0; index < MAX_NIC_TYPE; index++) {
  		/* Create device name lteXpdnX */
  		sprintf(pdn_dev_name, "lte%%dpdn%d", index);
  
  		/* Allocate netdev */
  		net = alloc_netdev(sizeof(struct nic), pdn_dev_name,
  				   NET_NAME_UNKNOWN, ether_setup);
  		if (!net) {
  			ret = -ENOMEM;
  			goto err;
  		}
  		net->netdev_ops = &gdm_netdev_ops;
  		net->flags &= ~IFF_MULTICAST;
  		net->mtu = DEFAULT_MTU_SIZE;
  
  		nic = netdev_priv(net);
  		memset(nic, 0, sizeof(struct nic));
  		nic->netdev = net;
  		nic->phy_dev = phy_dev;
  		nic->nic_id = index;
  
  		form_mac_address(net->dev_addr,
  				 nic->src_mac_addr,
  				 nic->dest_mac_addr,
  				 mac_address,
  				 index);
  
  		SET_NETDEV_DEV(net, dev);
  		SET_NETDEV_DEVTYPE(net, &wwan_type);
  
  		ret = register_netdev(net);
  		if (ret)
  			goto err;
  
  		netif_carrier_on(net);
  
  		phy_dev->dev[index] = net;
  	}
  
  	return 0;
  
  err:
  	unregister_lte_device(phy_dev);
  
  	return ret;
  }
  
  void unregister_lte_device(struct phy_dev *phy_dev)
  {
  	struct net_device *net;
  	int index;
  
  	for (index = 0; index < MAX_NIC_TYPE; index++) {
  		net = phy_dev->dev[index];
  		if (!net)
  			continue;
  
  		unregister_netdev(net);
  		free_netdev(net);
  	}
  }
  