Datastructures

Here are the main datastructures used :

• The `vif' datastructure : The vif datastructure represents an interface .

  typedef struct _vif {
          int             vif_vdld;       /* link number the interface 
                                             is connected to */
          int             vif_vdlno;      /* Interface number */
          int             vif_hwaddr;     /* Physical address */
          fun_ptr        *vdl_prototab;   /* array of  pointers to functions*/
                                           * used as call-back functions */
  
          char          **varp_fifo;      /* contains the fifo file name 
                                           * associated to the communication 
                                             with the varp module  */
          char          **vip_fifo;
          char          **vrip_fifo;
  
          in_addr_t       vif_ifaddr; /* Ip address of the interface */
          in_addr_t       vif_ifmask; /* Network mask */
          in_addr_t       vif_bcaddr; /* Broadcast address */
          unsigned int    vif_flags;  /* flags ( interface status ) */
  } vif;
  

• The varp_entry datastructure : This datastructure is used to save varp entries, it is also the VARP hash table element types.

  typedef struct _varp_entry {
          int             varp_linkid;
          int             varp_hwaddr;
          in_addr_t       varp_addr;
          int             age; 
          unsigned int    varp_flags ;
  } varp_entry;
  

• The varp_packet datastructure : This datastructure is used to send VARP packets

  typedef struct _varp_packet {
          int             varp_type; /*message type */
          int             varp_link; /* linkk ID */
          int             varp_phw;  /* hardware address */
          in_addr_t       varp_ip;   /* IP address */
          in_addr_t       varp_src_ip; /* sender IP address */
          int             varp_src_hwaddr; /* sender hw address */
  } varp_packet;
  

• The vrip_entry datastructure :

  typedef struct _vrip_entry {
          in_addr_t       dest_ip;
          in_addr_t       dest_gw;
          int             metric;
          int             update_c;
          char            id[20];
  
  } vrip_entry;
  

• The vrip_packet datastructure :

  typedef struct _vrip_packet {
  
          int             command;
          in_addr_t       dest_ip;
          in_addr_t       dest_gw;
          int             metric;
  } vrip_packet;
  

• The ip_packet datastructure :

  typedef struct _viphdr {
          in_addr_t       vipdst;
          in_addr_t       vipsrc;
          in_addr_t       vip_nexthop; /* Next gateway in the path.
                                        * this parameter is setup by 
                                        * the routing algorothm */
          uint8_t         vipttl;
          uint8_t         vipproto;
          int             payload_sz; /* payload size */
  } viphdr;
  
  typedef struct _vip_pkt {
          viphdr          hdr; /* the IP packet header */
          char            payload[200];
  } vip_pkt;