#ifndef __LWIP_NETIF_H__
#define __LWIP_NETIF_H__

#include "lwdef.h"
#include "err.h"
#include "pbuf.h"


/** must be the maximum of all used hardware address lengths
    across all types of interfaces in use */
#define NETIF_MAX_HWADDR_LEN 6U

/** TODO: define the use (where, when, whom) of netif flags */

/** whether the network interface is 'up'. this is
 * a software flag used to control whether this network
 * interface is enabled and processes traffic.
 */
#define NETIF_FLAG_UP 0x1U
/** if set, the netif has broadcast capability */
#define NETIF_FLAG_BROADCAST 0x2U
/** if set, the netif is one end of a point-to-point connection */
#define NETIF_FLAG_POINTTOPOINT 0x4U
/** if set, the interface is configured using DHCP */
#define NETIF_FLAG_DHCP 0x08U
/** if set, the interface has an active link
 *  (set by the network interface driver) */
#define NETIF_FLAG_LINK_UP 0x10U

/** Generic data structure used for all lwIP network interfaces.
 *  The following fields should be filled in by the initialization
 *  function for the device driver: hwaddr_len, hwaddr[], mtu, flags */

struct netif {
  /** pointer to next in linked list */
  struct netif *next;

  /** IP address configuration in network byte order */
  Uint32 ip_addr;
  Uint32 netmask;
  Uint32 gw;

  /** This function is called by the network device driver
   *  to pass a packet up the TCP/IP stack. */
  err_t (* input)(struct pbuf *p, struct netif *inp);
  /** This function is called by the IP module when it wants
   *  to send a packet on the interface. This function typically
   *  first resolves the hardware address, then sends the packet. */
  err_t (* output)(struct netif *netif, struct pbuf *p,
       Uint32 *ipaddr);
  /** This function is called by the ARP module when it wants
   *  to send a packet on the interface. This function outputs
   *  the pbuf as-is on the link medium. */
  err_t (* linkoutput)(struct netif *netif, struct pbuf *p);
  /** This field can be set by the device driver and could point
   *  to state information for the device. */
  void *state;
#if LWIP_DHCP
  /** the DHCP client state information for this netif */
  struct dhcp *dhcp;
#endif
  /** number of bytes used in hwaddr */
  unsigned char hwaddr_len;
  /** link level hardware address of this interface */
  unsigned char hwaddr[NETIF_MAX_HWADDR_LEN];
  /** maximum transfer unit (in bytes) */
  u16_t mtu;
  /** flags (see NETIF_FLAG_ above) */
  u8_t flags;
  /** link type */
  u8_t link_type;
  /** descriptive abbreviation */
  char name[2];
  /** number of this interface */
  u8_t num;
};

/** The list of network interfaces. */
extern struct netif *netif_list;
/** The default network interface. */
extern struct netif *netif_default;

/* netif_init() must be called first. */
void netif_init(void);

struct netif *netif_add(struct netif *netif, Uint32 *ipaddr, Uint32 *netmask,
      Uint32 *gw,
      void *state,
      err_t (* init)(struct netif *netif),
      err_t (* input)(struct pbuf *p, struct netif *netif));

void
netif_set_addr(struct netif *netif,Uint32 *ipaddr, Uint32 *netmask,
    Uint32 *gw);
void netif_remove(struct netif * netif);

/* Returns a network interface given its name. The name is of the form
   "et0", where the first two letters are the "name" field in the
   netif structure, and the digit is in the num field in the same
   structure. */
struct netif *netif_find(char *name);

void netif_set_default(struct netif *netif);

void netif_set_ipaddr(struct netif *netif, Uint32 *ipaddr);
void netif_set_netmask(struct netif *netif, Uint32 *netmast);
void netif_set_gw(struct netif *netif, Uint32 *gw);
void netif_set_up(struct netif *netif);
void netif_set_down(struct netif *netif);
u8_t netif_is_up(struct netif *netif);

#endif /* __LWIP_NETIF_H__ */