asnapi.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 "stdioLib.h"
#include "strLib.h"
#include "ioLib.h"
#include "fioLib.h"

#include "snmp.h"

char *asnGetType(char *buf,int *buflen,char *type)
{
	(*type) = buf[0];
	(*buflen) = (*buflen) - 1;
	return (buf + 1);
}

char *asnGetLen(char *buf,int *buflen,int *asnlen)
{
	int count = 0;
	int number,temp,len;
	char backup;
	
	if(buf[count] < 0x80)
	{
		(*asnlen) = buf[count];
		(*buflen) = (*buflen) - 1;
		if((*asnlen) > (*buflen))
			return (char *)ERROR;
		return (buf + 1);
	}
	else
	{
		number = buf[count]&0x7f;
		if(number > (*buflen))
			return (char *)ERROR;
		count++;
		for(temp = len = 0;temp < number;temp++)
		{
			backup = buf[count + temp];
			len = (len <<8) + backup;
		}
		(*asnlen) = len;
		(*buflen) = (*buflen) - 1 - number;
		if((*asnlen) > (*buflen))
			return (char *)ERROR;
		return (buf + 1 + number);
	}
}
char *asnGetVersion(SNMP_PDU *snmp,char *buf,int *buflen)
{
	snmp->version = buf[0];
	(*buflen) = (*buflen) - 1;
	return (buf + 1);
}

char *asnGetCommuName(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	if((*asnlen) > (*buflen))
		return (char *)ERROR;
	snmp->community_len  = (*asnlen);
	snmp->community = snmpMalloc((*asnlen));
	memcpy(snmp->community,buf,(*asnlen));
	(*buflen) = (*buflen) - (*asnlen);
	return (buf + (*asnlen));
}

char *asnGetPduCommand(SNMP_PDU *snmp,char *buf,int *buflen)
{
	snmp->command = buf[0];
	(*buflen) = (*buflen) - 1;
	return (buf + 1);
}

char *asnGetRequestID(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	int len;
	if((*asnlen) > (*buflen))
		return (char *)ERROR;
	for(len = snmp->reqid = 0 ; len < (*asnlen); len++)
		snmp->reqid = (snmp->reqid<<8) + buf[len];
	HTONL(snmp->reqid);
	(*buflen) = (*buflen) - (*asnlen);
	return  (buf + (*asnlen));
}

char *asnGetErrorStatus(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	snmp->errstat = buf[0];
	(*buflen) = (*buflen) - 1;
	return (buf + 1);
}

char *asnGetErrorIndex(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	snmp->errindex = buf[0];
	(*buflen) = (*buflen) - 1;
	return (buf + 1);
}

//获取VARLIST中的OID以及紧跟着的VALUE
char *asnGetOID(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	int 	len;
	VARLIST *temp,*swap;
	temp = snmpMalloc(sizeof(VARLIST));
	temp->next = temp->value = NULL;
	temp->oid_len = (*asnlen);
	memcpy(temp->oid, buf, (*asnlen));
	(*buflen) = (*buflen) - (*asnlen);
	buf =  (buf + (*asnlen));
	if((buf = (char *)asnGetType(buf,buflen,&(temp->type))) == (char *)ERROR)
		return (char *)ERROR;
	switch(temp->type)
	{
		case TAG_NULL:
			(*buflen) = (*buflen) - 1;
			buf =  (buf + 1);
			break;
		case TAG_OCTET:
		case TAG_INTERGER:
		default:
			if((buf = (char *)asnGetLen(buf,buflen,(int *)&len)) == (char *)ERROR)
				return (char *)ERROR;
			temp->value_len = len;
			temp->value = snmpMalloc(len);
			memcpy(temp->value, buf, len);
			(*buflen) = (*buflen) - len;
			buf = (buf + len);
			break;
	}	
	swap = snmp->variables;
	if(swap == NULL)
		snmp->variables = temp;
	else
	{
		for(;swap->next != NULL; swap = swap->next);
		swap->next = temp;
	}
	return buf;
}

//下面的全部都是Trap专用PDU报文处理函数
char *asnGetEntID(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	if((*asnlen) > (*buflen))
		return (char *)ERROR;
	snmp->enterprise_length = (*asnlen);
	snmp->enterprise 		= snmpMalloc((*asnlen));
	memcpy(snmp->enterprise, buf, (*asnlen));
	(*buflen) = (*buflen) - (*asnlen);
	return  (buf + (*asnlen));
}


char *asnGetAgentIP(SNMP_PDU *snmp, char *buf,int *buflen,int *asnlen)
{
	if((*asnlen) > (*buflen))
		return (char *)ERROR;
	memcpy(snmp->agent_addr, buf, (*asnlen));
	(*buflen) = (*buflen) - (*asnlen);
	return  (buf + (*asnlen));
}


char *asnGetTraptype(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	snmp->trap_type = buf[0];
	(*buflen) = (*buflen) - 1;
	return (buf + 1);
}

char *asnGetSpecTrap(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	int len;
	if((*asnlen) > (*buflen))
		return (char *)ERROR;
	for(len = snmp->specific_type = 0 ; len < (*asnlen); len++)
		snmp->specific_type = (snmp->specific_type<<8) + buf[len];
	(*buflen) = (*buflen) - (*asnlen);
	return  (buf + (*asnlen));
}

char *asnGetTrapTime(SNMP_PDU *snmp,char *buf,int *buflen,int *asnlen)
{
	int len;
	if((*asnlen) > (*buflen))
		return (char *)ERROR;
	for(len = snmp->time = 0 ; len < (*asnlen); len++)
		snmp->time = (snmp->time<<8) + buf[len];
	(*buflen) = (*buflen) - (*asnlen);
	return  (buf + (*asnlen));
}
		
		
//传入的OUT不要忘记申请内存
int OIDLongToChar(const u_long *input,int inlen,char *out,int *outlen)
{
	int intemp,outemp;
	long s1,s2;
	
	if(inlen == 1)
	{
		s1 = input[0];
		if(s1 < 4)
		{
			out[0] = s1 * 40;
			return TRUE;
		}
		return ERROR;
		
	}
	for(intemp = outemp = 0; intemp < inlen; )
	{
		if(intemp == 0)
		{
			s1 = input[0];
			s2 = input[1];
			out[0] = s1 * 40 + s2;
			if(out[0] > 0x7f)
			{
				return ERROR;
			}
			outemp = 1;
			intemp = 2;
		}
		else
		{
			s1 = input[intemp];
			if( (s1&0xffffff80) == 0 )
				out[outemp] = (s1&0x7f);
			else
			{
				out[outemp] = ((s1/128) | 0x80);
				outemp++;
				out[outemp] = (s1%128);
			}
			outemp++;
			intemp++;
		}
	}
	(*outlen) = outemp + 1;
	return TRUE;
}

//传入的OUT不要忘记申请内存
int OIDCharToLong(char *input,int inlen,long *out,long *outlen)
{
	int intemp,outemp;
	long s1,s2;
	
	for(intemp = outemp = 0; intemp < inlen; )
	{
		if(intemp == 0)
		{
			s1 = input[0]/40;
			s2 = input[0]%40;
			out[0] = s1;
			out[1] = s2;
			outemp = 2;
			intemp = 1;
		}
		else
		{
			if(outemp > MAX_OIDLEN)
				return ERROR;
			s1 = input[intemp];
			if( s1 < 0x80 )
				out[outemp] = s1;
			else
			{
				s2 = input[intemp + 1];
				out[outemp] = ((s1&0x7f)*128) + s2;
				intemp++;
			}
			outemp++;
			intemp++;
		}
	}
	(*outlen) = outemp;
	return TRUE ;
}