(2.0.)

  ++ Application changes:

  * Changed netif "up" flag handling to be an administrative flag (as opposed to the previous meaning of

    "ip4-address-valid", a netif will now not be used for transmission if not up) -> even a DHCP netif

    has to be set "up" before starting the DHCP client

  * Added IPv6 support (dual-stack or IPv4/IPv6 only)

  * Changed ip_addr_t to be a union in dual-stack mode (use ip4_addr_t where referring to IPv4 only).

  * Major rewrite of SNMP (added MIB parser that creates code stubs for custom MIBs);

    supports SNMPv2c (experimental v3 support)

  * Moved some core applications from contrib repository to src/apps (and include/lwip/apps)

/** 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 */

  ip_addr_t ip_addr;

  ip_addr_t netmask;

  ip_addr_t gw;

/** 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;

#if LWIP_IPV4

  /** IP address configuration in network byte order */

  ip_addr_t ip_addr;

  ip_addr_t netmask;

  ip_addr_t gw;

#endif /* LWIP_IPV4 */

#if LWIP_IPV6

  /** Array of IPv6 addresses for this netif. */

  ip_addr_t ip6_addr[LWIP_IPV6_NUM_ADDRESSES];

  /** The state of each IPv6 address (Tentative, Preferred, etc).

   * @see ip6_addr.h */

  u8_t ip6_addr_state[LWIP_IPV6_NUM_ADDRESSES];

#endif /* LWIP_IPV6 */

/* ip_route:

 *

 * Finds the appropriate network interface for a given IP address. It searches the

 * list of network interfaces linearly. A match is found if the masked IP address of

 * the network interface equals the masked IP address given to the function.

 */

struct netif *

ip_route(struct ip_addr *dest)

{

  struct netif *netif;

  for(netif = netif_list; netif != NULL; netif = netif->next) {

    if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {

      return netif;

    }

  }

  return netif_default;

}

/**

 * Finds the appropriate network interface for a given IPv6 address. It tries to select

 * a netif following a sequence of heuristics:

 * 1) if there is only 1 netif, return it

 * 2) if the destination is a link-local address, try to match the src address to a netif.

 *    this is a tricky case because with multiple netifs, link-local addresses only have

 *    meaning within a particular subnet/link.

 * 3) tries to match the destination subnet to a configured address

 * 4) tries to find a router

 * 5) tries to match the source address to the netif

 * 6) returns the default netif, if configured

 *

 * @param src the source IPv6 address, if known

 * @param dest the destination IPv6 address for which to find the route

 * @return the netif on which to send to reach dest

 */

struct netif *

ip6_route(const ip6_addr_t *src, const ip6_addr_t *dest)