本文主要是介绍ospf-ism-and-nsm-code-printf，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
ospf 不同状态机起的定时器：
ism: ospf-ifp ism_down ->(event:l3-ifp-up)-> ism_waiting -> 等待ism选举【起waiting等待定时器】nsm->down ->(event:hello-PacketReceived)-> nsm_init 【接收处理hello报文，OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_OneWayReceived); 知道hello报文发现对端邻居Active Neighbor: 4.4.4.4】 -> OSPF_NSM_EVENT_SCHEDULE (nbr, NSM_TwoWayReceived);【直到ism选举出来drX/bdrX出来, nsm其状态发生变化】 ->(adj【bdrX/drX选举成功进入exStart否则进入twoway等待ism选举】 ? NSM_ExStart : NSM_TwoWay); -> ism选举未成功，nsm状态切换到two-way,等待ism选举。 -> 选举成功进入到nsm-exstart, db-desc报文交互，目的协商主从关系，协商序列号，同时起db-desc定时器发送，直到nsm-exstart切换到下一个状态则取消其定时器发送db-desc报文。-> 如果邻居router-id > self-router-id, 则邻居是master. --> 主从关系协商ok，产生self-lsa安装在database中 -> 状态切换到nsm-exchange, 起定期器更新邻居状态数据库LSAstatic void
nsm_timer_set (struct ospf_neighbor *nbr)
{switch (nbr->state){case NSM_Deleted:case NSM_Down:OSPF_NSM_TIMER_OFF (nbr->t_inactivity);OSPF_NSM_TIMER_OFF (nbr->t_hello_reply);case NSM_Attempt:case NSM_Init:case NSM_TwoWay:OSPF_NSM_TIMER_OFF (nbr->t_db_desc);OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);OSPF_NSM_TIMER_OFF (nbr->t_ls_req);break;case NSM_ExStart:OSPF_NSM_TIMER_ON (nbr->t_db_desc, ospf_db_desc_timer, nbr->v_db_desc);OSPF_NSM_TIMER_OFF (nbr->t_ls_upd);OSPF_NSM_TIMER_OFF (nbr->t_ls_req);break;case NSM_Exchange:OSPF_NSM_TIMER_ON (nbr->t_ls_upd, ospf_ls_upd_timer, nbr->v_ls_upd);if (!IS_SET_DD_MS (nbr->dd_flags))OSPF_NSM_TIMER_OFF (nbr->t_db_desc);break;case NSM_Loading:case NSM_Full:default:OSPF_NSM_TIMER_OFF (nbr->t_db_desc);break;}
}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 stateinterface parameters must be set to initial values, and timers arereset 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 beunavailable 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 andBDRouter. 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);if (OSPF_IF_PARAM_CONFIGURED (oi->params, fast_hello))OSPF_ISM_TIMER_ON (oi->t_wait, ospf_wait_timer, 10);elseOSPF_ISM_TIMER_ON (oi->t_wait, ospf_wait_timer, (OSPF_IF_PARAM (oi, v_hello)*4));OSPF_ISM_TIMER_OFF (oi->t_ls_ack);break;case ISM_PointToPoint:/* The interface connects to a physical Point-to-point network orvirtual link. The router attempts to form an adjacency withneighboring 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 norBackup 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;}
}
NSM: 邻居状态机
ISM 接口状态机
/* Interface State Machine */
struct {int (*func) (struct ospf_interface *);int next_state;
} ISM [OSPF_ISM_STATE_MAX][OSPF_ISM_EVENT_MAX] =
{{/* DependUpon: dummy state. */{ ism_ignore, ISM_DependUpon }, /* NoEvent */{ ism_ignore, ISM_DependUpon }, /* InterfaceUp */{ ism_ignore, ISM_DependUpon }, /* WaitTimer */{ ism_ignore, ISM_DependUpon }, /* BackupSeen */{ ism_ignore, ISM_DependUpon }, /* NeighborChange */{ ism_ignore, ISM_DependUpon }, /* LoopInd */{ ism_ignore, ISM_DependUpon }, /* UnloopInd */{ ism_ignore, ISM_DependUpon }, /* InterfaceDown */},{/* Down:*/{ ism_ignore, ISM_DependUpon }, /* NoEvent */{ ism_interface_up, ISM_DependUpon }, /* InterfaceUp */{ ism_ignore, ISM_Down }, /* WaitTimer */{ ism_ignore, ISM_Down }, /* BackupSeen */{ ism_ignore, ISM_Down }, /* NeighborChange */{ ism_loop_ind, ISM_Loopback }, /* LoopInd */{ ism_ignore, ISM_Down }, /* UnloopInd */{ ism_interface_down, ISM_Down }, /* InterfaceDown */},{/* Loopback: */{ ism_ignore, ISM_DependUpon }, /* NoEvent */{ ism_ignore, ISM_Loopback }, /* InterfaceUp */{ ism_ignore, ISM_Loopback }, /* WaitTimer */{ ism_ignore, ISM_Loopback }, /* BackupSeen */{ ism_ignore, ISM_Loopback }, /* NeighborChange */{ ism_ignore, ISM_Loopback }, /* LoopInd */{ ism_ignore, ISM_Down }, /* UnloopInd */{ ism_interface_down, ISM_Down }, /* InterfaceDown */},{/* Waiting: */{ ism_ignore, ISM_DependUpon }, /* NoEvent */{ ism_ignore, ISM_Waiting }, /* InterfaceUp */{ ism_wait_timer, ISM_DependUpon }, /* WaitTimer */{ ism_backup_seen, ISM_DependUpon }, /* BackupSeen */{ ism_ignore, ISM_Waiting }, /* NeighborChange */{ ism_loop_ind, ISM_Loopback }, /* LoopInd */{ ism_ignore, ISM_Waiting }, /* UnloopInd */{ ism_interface_down, ISM_Down }, /* InterfaceDown */},{/* Point-to-Point: */{ ism_ignore, ISM_DependUpon }, /* NoEvent */{ ism_ignore, ISM_PointToPoint }, /* InterfaceUp */{ ism_ignore, ISM_PointToPoint }, /* WaitTimer */{ ism_ignore, ISM_PointToPoint }, /* BackupSeen */{ ism_ignore, ISM_PointToPoint }, /* NeighborChange */{ ism_loop_ind, ISM_Loopback }, /* LoopInd */{ ism_ignore, ISM_PointToPoint }, /* UnloopInd */{ ism_interface_down, ISM_Down }, /* InterfaceDown */},{/* DROther: */{ ism_ignore, ISM_DependUpon }, /* NoEvent */{ ism_ignore, ISM_DROther }, /* InterfaceUp */{ ism_ignore, ISM_DROther }, /* WaitTimer */{ ism_ignore, ISM_DROther }, /* BackupSeen */{ ism_neighbor_change, ISM_DependUpon }, /* NeighborChange */{ ism_loop_ind, ISM_Loopback }, /* LoopInd */{ ism_ignore, ISM_DROther }, /* UnloopInd */{ ism_interface_down, ISM_Down }, /* InterfaceDown */},{/* Backup: */{ ism_ignore, ISM_DependUpon }, /* NoEvent */{ ism_ignore, ISM_Backup }, /* InterfaceUp */{ ism_ignore, ISM_Backup }, /* WaitTimer */{ ism_ignore, ISM_Backup }, /* BackupSeen */{ ism_neighbor_change, ISM_DependUpon }, /* NeighborChange */{ ism_loop_ind, ISM_Loopback }, /* LoopInd */{ ism_ignore, ISM_Backup }, /* UnloopInd */{ ism_interface_down, ISM_Down }, /* InterfaceDown */},{/* DR: */{ ism_ignore, ISM_DependUpon }, /* NoEvent */{ ism_ignore, ISM_DR }, /* InterfaceUp */{ ism_ignore, ISM_DR }, /* WaitTimer */{ ism_ignore, ISM_DR }, /* BackupSeen */{ ism_neighbor_change, ISM_DependUpon }, /* NeighborChange */{ ism_loop_ind, ISM_Loopback }, /* LoopInd */{ ism_ignore, ISM_DR }, /* UnloopInd */{ ism_interface_down, ISM_Down }, /* InterfaceDown */},
};/* Neighbor State Machine */
struct {int (*func) (struct ospf_neighbor *);int next_state;
} NSM [OSPF_NSM_STATE_MAX][OSPF_NSM_EVENT_MAX] =
{{/* DependUpon: dummy state. */{ NULL, NSM_DependUpon }, /* NoEvent */{ NULL, NSM_DependUpon }, /* PacketReceived */{ NULL, NSM_DependUpon }, /* Start */{ NULL, NSM_DependUpon }, /* 2-WayReceived */{ NULL, NSM_DependUpon }, /* NegotiationDone */{ NULL, NSM_DependUpon }, /* ExchangeDone */{ NULL, NSM_DependUpon }, /* BadLSReq */{ NULL, NSM_DependUpon }, /* LoadingDone */{ NULL, NSM_DependUpon }, /* AdjOK? */{ NULL, NSM_DependUpon }, /* SeqNumberMismatch */{ NULL, NSM_DependUpon }, /* 1-WayReceived */{ NULL, NSM_DependUpon }, /* KillNbr */{ NULL, NSM_DependUpon }, /* InactivityTimer */{ NULL, NSM_DependUpon }, /* LLDown */},{/* Deleted: dummy state. */{ NULL, NSM_Deleted }, /* NoEvent */{ NULL, NSM_Deleted }, /* PacketReceived */{ NULL, NSM_Deleted }, /* Start */{ NULL, NSM_Deleted }, /* 2-WayReceived */{ NULL, NSM_Deleted }, /* NegotiationDone */{ NULL, NSM_Deleted }, /* ExchangeDone */{ NULL, NSM_Deleted }, /* BadLSReq */{ NULL, NSM_Deleted }, /* LoadingDone */{ NULL, NSM_Deleted }, /* AdjOK? */{ NULL, NSM_Deleted }, /* SeqNumberMismatch */{ NULL, NSM_Deleted }, /* 1-WayReceived */{ NULL, NSM_Deleted }, /* KillNbr */{ NULL, NSM_Deleted }, /* InactivityTimer */{ NULL, NSM_Deleted }, /* LLDown */},{/* Down: */{ NULL, NSM_DependUpon }, /* NoEvent */{ nsm_packet_received, NSM_Init }, /* PacketReceived */{ nsm_start, NSM_Attempt }, /* Start */{ NULL, NSM_Down }, /* 2-WayReceived */{ NULL, NSM_Down }, /* NegotiationDone */{ NULL, NSM_Down }, /* ExchangeDone */{ NULL, NSM_Down }, /* BadLSReq */{ NULL, NSM_Down }, /* LoadingDone */{ NULL, NSM_Down }, /* AdjOK? */{ NULL, NSM_Down }, /* SeqNumberMismatch */{ NULL, NSM_Down }, /* 1-WayReceived */{ nsm_kill_nbr, NSM_Deleted }, /* KillNbr */{ nsm_kill_nbr, NSM_Deleted }, /* InactivityTimer */{ nsm_kill_nbr, NSM_Deleted }, /* LLDown */},{/* Attempt: */{ NULL, NSM_DependUpon }, /* NoEvent */{ nsm_packet_received, NSM_Init }, /* PacketReceived */{ NULL, NSM_Attempt }, /* Start */{ NULL, NSM_Attempt }, /* 2-WayReceived */{ NULL, NSM_Attempt }, /* NegotiationDone */{ NULL, NSM_Attempt }, /* ExchangeDone */{ NULL, NSM_Attempt }, /* BadLSReq */{ NULL, NSM_Attempt }, /* LoadingDone */{ NULL, NSM_Attempt }, /* AdjOK? */{ NULL, NSM_Attempt }, /* SeqNumberMismatch */{ NULL, NSM_Attempt }, /* 1-WayReceived */{ nsm_kill_nbr, NSM_Deleted }, /* KillNbr */{ nsm_kill_nbr, NSM_Deleted }, /* InactivityTimer */{ nsm_kill_nbr, NSM_Deleted }, /* LLDown */},{/* Init: */{ NULL, NSM_DependUpon }, /* NoEvent */{ nsm_packet_received, NSM_Init }, /* PacketReceived */{ NULL, NSM_Init }, /* Start */{ nsm_twoway_received, NSM_DependUpon }, /* 2-WayReceived */{ NULL, NSM_Init }, /* NegotiationDone */{ NULL, NSM_Init }, /* ExchangeDone */{ NULL, NSM_Init }, /* BadLSReq */{ NULL, NSM_Init }, /* LoadingDone */{ NULL, NSM_Init }, /* AdjOK? */{ NULL, NSM_Init }, /* SeqNumberMismatch */{ NULL, NSM_Init }, /* 1-WayReceived */{ nsm_kill_nbr, NSM_Deleted }, /* KillNbr */{ nsm_kill_nbr, NSM_Deleted }, /* InactivityTimer */{ nsm_kill_nbr, NSM_Deleted }, /* LLDown */},{/* 2-Way: */{ NULL, NSM_DependUpon }, /* NoEvent */{ nsm_packet_received, NSM_TwoWay }, /* HelloReceived */{ NULL, NSM_TwoWay }, /* Start */{ NULL, NSM_TwoWay }, /* 2-WayReceived */{ NULL, NSM_TwoWay }, /* NegotiationDone */{ NULL, NSM_TwoWay }, /* ExchangeDone */{ NULL, NSM_TwoWay }, /* BadLSReq */{ NULL, NSM_TwoWay }, /* LoadingDone */{ nsm_adj_ok, NSM_DependUpon }, /* AdjOK? */{ NULL, NSM_TwoWay }, /* SeqNumberMismatch */{ NULL, NSM_Init }, /* 1-WayReceived */{ nsm_kill_nbr, NSM_Deleted }, /* KillNbr */{ nsm_kill_nbr, NSM_Deleted }, /* InactivityTimer */{ nsm_kill_nbr, NSM_Deleted }, /* LLDown */},{/* ExStart: */{ NULL, NSM_DependUpon }, /* NoEvent */{ nsm_packet_received, NSM_ExStart }, /* PacaketReceived */{ NULL, NSM_ExStart }, /* Start */{ NULL, NSM_ExStart }, /* 2-WayReceived */{ nsm_negotiation_done, NSM_Exchange }, /* NegotiationDone */{ NULL, NSM_ExStart }, /* ExchangeDone */{ NULL, NSM_ExStart }, /* BadLSReq */{ NULL, NSM_ExStart }, /* LoadingDone */{ nsm_adj_ok, NSM_DependUpon }, /* AdjOK? */{ NULL, NSM_ExStart }, /* SeqNumberMismatch */{ NULL, NSM_Init }, /* 1-WayReceived */{ nsm_kill_nbr, NSM_Deleted }, /* KillNbr */{ nsm_kill_nbr, NSM_Deleted }, /* InactivityTimer */{ nsm_kill_nbr, NSM_Deleted }, /* LLDown */},{/* Exchange: */{ NULL, NSM_DependUpon }, /* NoEvent */{ nsm_packet_received, NSM_Exchange }, /* PacketReceived */{ NULL, NSM_Exchange }, /* Start */{ NULL, NSM_Exchange }, /* 2-WayReceived */{ NULL, NSM_Exchange }, /* NegotiationDone */{ nsm_exchange_done, NSM_DependUpon }, /* ExchangeDone */{ NULL, NSM_ExStart }, /* BadLSReq */{ NULL, NSM_Exchange }, /* LoadingDone */{ nsm_adj_ok, NSM_DependUpon }, /* AdjOK? */{ NULL, NSM_ExStart }, /* SeqNumberMismatch */{ NULL, NSM_Init }, /* 1-WayReceived */{ nsm_kill_nbr, NSM_Deleted }, /* KillNbr */{ nsm_kill_nbr, NSM_Deleted }, /* InactivityTimer */{ nsm_kill_nbr, NSM_Deleted }, /* LLDown */},{/* Loading: */{ NULL, NSM_DependUpon }, /* NoEvent */{ nsm_packet_received, NSM_Loading }, /* PacketReceived */{ NULL, NSM_Loading }, /* Start */{ NULL, NSM_Loading }, /* 2-WayReceived */{ NULL, NSM_Loading }, /* NegotiationDone */{ NULL, NSM_Loading }, /* ExchangeDone */{ NULL, NSM_ExStart }, /* BadLSReq */{ NULL, NSM_Full }, /* LoadingDone */{ nsm_adj_ok, NSM_DependUpon }, /* AdjOK? */{ NULL, NSM_ExStart }, /* SeqNumberMismatch */{ NULL, NSM_Init }, /* 1-WayReceived */{ nsm_kill_nbr, NSM_Deleted }, /* KillNbr */{ nsm_kill_nbr, NSM_Deleted }, /* InactivityTimer */{ nsm_kill_nbr, NSM_Deleted }, /* LLDown */},{ /* Full: */{ NULL, NSM_DependUpon }, /* NoEvent */{ nsm_packet_received, NSM_Full }, /* PacketReceived */{ NULL, NSM_Full }, /* Start */{ NULL, NSM_Full }, /* 2-WayReceived */{ NULL, NSM_Full }, /* NegotiationDone */{ NULL, NSM_Full }, /* ExchangeDone */{ NULL, NSM_ExStart }, /* BadLSReq */{ NULL, NSM_Full }, /* LoadingDone */{ nsm_adj_ok, NSM_DependUpon }, /* AdjOK? */{ NULL, NSM_ExStart }, /* SeqNumberMismatch */{ NULL, NSM_Init }, /* 1-WayReceived */{ nsm_kill_nbr, NSM_Deleted }, /* KillNbr */{ nsm_kill_nbr, NSM_Deleted }, /* InactivityTimer */{ nsm_kill_nbr, NSM_Deleted }, /* LLDown */},
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