int ospf_hello_timer(struct thread *thread) { struct ospf_interface *oi; oi = THREAD_ARG(thread); oi->t_hello = NULL; if (IS_DEBUG_OSPF(ism, ISM_TIMERS)) zlog(NULL, LOG_DEBUG, "ISM[%s]: Timer (Hello timer expire)", IF_NAME(oi)); /* Sending hello packet. */ ospf_hello_send(oi); /* Hello timer set. */ OSPF_HELLO_TIMER_ON(oi); return 0; }
/* Hook function called after ospf ISM event is occured. And vty's network command invoke this function after making interface structure. */ static void ism_timer_set (struct ospf_interface *oi) { switch (oi->state) { case ISM_Down: /* First entry point of ospf interface state machine. In this state interface parameters must be set to initial values, and timers are reset also. */ OSPF_ISM_TIMER_OFF (oi->t_hello); OSPF_ISM_TIMER_OFF (oi->t_wait); OSPF_ISM_TIMER_OFF (oi->t_ls_ack); break; case ISM_Loopback: /* In this state, the interface may be looped back and will be unavailable for regular data traffic. */ OSPF_ISM_TIMER_OFF (oi->t_hello); OSPF_ISM_TIMER_OFF (oi->t_wait); OSPF_ISM_TIMER_OFF (oi->t_ls_ack); break; case ISM_Waiting: /* The router is trying to determine the identity of DRouter and BDRouter. The router begin to receive and send Hello Packets. */ /* send first hello immediately */ OSPF_ISM_TIMER_MSEC_ON (oi->t_hello, ospf_hello_timer, 1); OSPF_ISM_TIMER_ON (oi->t_wait, ospf_wait_timer, OSPF_IF_PARAM (oi, v_wait)); OSPF_ISM_TIMER_OFF (oi->t_ls_ack); break; case ISM_PointToPoint: /* The interface connects to a physical Point-to-point network or virtual link. The router attempts to form an adjacency with neighboring router. Hello packets are also sent. */ /* send first hello immediately */ OSPF_ISM_TIMER_MSEC_ON (oi->t_hello, ospf_hello_timer, 1); OSPF_ISM_TIMER_OFF (oi->t_wait); OSPF_ISM_TIMER_ON (oi->t_ls_ack, ospf_ls_ack_timer, oi->v_ls_ack); break; case ISM_DROther: /* The network type of the interface is broadcast or NBMA network, and the router itself is neither Designated Router nor Backup Designated Router. */ OSPF_HELLO_TIMER_ON (oi); OSPF_ISM_TIMER_OFF (oi->t_wait); OSPF_ISM_TIMER_ON (oi->t_ls_ack, ospf_ls_ack_timer, oi->v_ls_ack); break; case ISM_Backup: /* The network type of the interface is broadcast os NBMA network, and the router is Backup Designated Router. */ OSPF_HELLO_TIMER_ON (oi); OSPF_ISM_TIMER_OFF (oi->t_wait); OSPF_ISM_TIMER_ON (oi->t_ls_ack, ospf_ls_ack_timer, oi->v_ls_ack); break; case ISM_DR: /* The network type of the interface is broadcast or NBMA network, and the router is Designated Router. */ OSPF_HELLO_TIMER_ON (oi); OSPF_ISM_TIMER_OFF (oi->t_wait); OSPF_ISM_TIMER_ON (oi->t_ls_ack, ospf_ls_ack_timer, oi->v_ls_ack); break; } }