snmptrap.c

VxWorks操作系统下的SNMP协议以及MIB协议的实现源码,并且实现了HP标准打印类的MIB框架.

#include "VxWorks.h"
#include "sockLib.h"
#include "inetLib.h"
#include "taskLib.h"
#include "msgQLib.h"
#include "stdioLib.h"
#include "strLib.h"
#include "ioLib.h"
#include "fioLib.h"

#include "snmp.h"
extern MSG_Q_ID trap_rx;
char trapdata[4096];

struct 	sockaddr_in nmsAddr;
int		nmsFd;
int snmpTrap()
{
	struct 	sockaddr_in serverSock; 	//服务器socket地址
	int 	sockAddrSize;	/*socket地址的数据结构大小*/
	u_long 	count = 0;
	
	
	//printf("\n<<_TRAP>> SNMP Trap start!!!!!!!!");
	
	sockAddrSize = sizeof(struct sockaddr_in);
	bzero((char *)&serverSock,sockAddrSize);
	serverSock.sin_family = AF_INET;
	serverSock.sin_len = (u_char)sockAddrSize;
	serverSock.sin_port = htons(SNMP_TRAP);
	serverSock.sin_addr.s_addr = htonl(INADDR_ANY);
	
	//创建基于TCP的socket
	if((nmsFd = socket(AF_INET,SOCK_DGRAM,0)) == ERROR)
	{
		printf("\n<<_TRAP>> Socket create error!");
		return (ERROR);
	}
	
	//将socket绑定在本地地址上
	if(bind(nmsFd,(struct sockaddr*)&serverSock, sockAddrSize) == ERROR)
	{
		printf("\n<<_TRAP>> Socket bind error!");
		close(nmsFd);
		return (ERROR);
	}

	//循环监听端口数据
	while(1)
	{
		if(PrepareTrap(nmsFd) != ERROR)
		{
			printf("\n<<_TRAP>> Over %d turn",count++);
		}
	}
}

int PrepareTrap(int sFd)
{
	int 		sockAddrSize;				/*socket地址的数据结构大小*/
	int 		buflen,snmplen,pdulen,asnlen;
	char 		type;
	char 		*buf,*backup;
	char 		address[20];
	TRAPMSG 	tx_msg;
	SNMP_PDU 	*snmp;
	
	sockAddrSize 	= sizeof(struct sockaddr_in);
	snmp 			= snmpMalloc(sizeof(SNMP_PDU));
	initSNMP(snmp);
	memset(trapdata,0,4096);
	if((buflen = recvfrom(sFd, trapdata, 4096, 0, (struct sockaddr *)&nmsAddr, &sockAddrSize)) == ERROR) 
	{ 
		printf("\n<<_TRAP>> recvfrom UDP161 ERROR");
		freesnmpPDU(snmp);
		return ERROR;
	}
	inet_ntoa_b(nmsAddr.sin_addr,address);
	printf("\n<<_TRAP>> NMS = %s",address);
	//TAG:SEQUENCE--0x30 | LENGTH -- varies | VALUE -- varies
	if((buf = (char *)asnGetType(trapdata,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_SEQUENCE)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	if(buflen != asnlen)
		return ERROR;
	snmplen = asnlen;
	
	//VERSION TAG:INTEGER--0x2 | LENGTH -- 0x1 | VALUE -- (usually 0)
	if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_INTERGER)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR
	  || asnlen != 1)
		return ERROR;
	if((buf = (char *)asnGetVersion(snmp,buf,(int *)&buflen)) == (char *)ERROR)
		return ERROR;
	
	if(snmp->version != SNMPV1)
		return ERROR;
	
	//CommunityTAG:OCTET STRING -- 0x4 | LENGTH -- varies | VALUE -- varies
	if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_OCTET)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	if((buf = (char *)asnGetCommuName(snmp,buf,(int *)&buflen,&asnlen)) == (char *)ERROR)
		return ERROR;
	
	//PDU field TAG -- 0xa4(snmpv1) | LENGTH -- varies | VALUE -- varies
	if((buf = (char *)asnGetPduCommand(snmp,buf,(int *)&buflen)) == (char *)ERROR)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	if(buflen != asnlen)
		return ERROR;
	pdulen = asnlen;
	
	//enterprise TAG:OBJECT ID -- 0x6 | LENGTH -- varies | VALUE -- varies
	if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_OBJIDT)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	if((buf = (char *)asnGetEntID(snmp,buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	
	//agent address TAG: IPADDRESS -- 0x40 |LENGTH = 1| VALUE = 0
	if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_IP)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	if((buf = (char *)asnGetAgentIP(snmp,buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	
	//generic trap TAG: INTERGER | LENGTH = 1 | VALUE = varies
	if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_INTERGER)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR
	  || asnlen != 1)
		return ERROR;
	if((buf = (char *)asnGetTraptype(snmp,buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	
	//specific trap TAG: INTERGER | LENGTH = varies | VALUE = varies
	if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_INTERGER)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR
	  || asnlen != 1)
		return ERROR;
	if((buf = (char *)asnGetSpecTrap(snmp,buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
		
	//time stamp TAG: TIMETICK | LENGTH = varies | VALUE = varies
	if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_TIMETICK)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	if((buf = (char *)asnGetTrapTime(snmp,buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	
	//VarBindList TAG 0x30 | LENGTH -- varies | VALUE -- varies
	if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
	  ||type != TAG_SEQUENCE)
		return ERROR;
	if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
		return ERROR;
	if(buflen != asnlen)
		return ERROR;
	while(buflen > 0)
	{
		//Bind Variable TAG 0x30 | LENGTH -- varies | VALUE -- varies
		if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR)
			return ERROR;
		switch(type)
		{
			case TAG_SEQUENCE:
				if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
					return ERROR;
				
				//Variable Value TAG 0x6 | LENGTH -- varies | VALUE -- varies
				if((buf = (char *)asnGetType(buf,(int *)&buflen,&type)) == (char *)ERROR
				  ||type != TAG_OBJIDT)
					return ERROR;
				if((buf = (char *)asnGetLen(buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
					return ERROR;
				if((buf = (char *)asnGetOID(snmp,buf,(int *)&buflen,(int *)&asnlen)) == (char *)ERROR)
					return ERROR;
			default:
				break;

		}
	}//循环，直到所有数据，所有OID处理完毕
	tx_msg.msg = MSG_NMS_TRAP;
	tx_msg.snmp = snmp;
	msgQSend(trap_rx,(char *)&tx_msg,sizeof(TRAPMSG),WAIT_FOREVER,MSG_PRI_NORMAL);
}