decode_snmp.c

Go to the documentation of this file.

/*
 * decode_snmp.c
 *
 * Simple Network Management Protocol.
 *
 * Copyright (c) 2000 Dug Song <dugsong@monkey.org>
 *
 * $Id: decode_snmp.c,v 1.6 2001/03/15 08:33:02 dugsong Exp $
 */
 
#include "config.h"
 
#include <sys/types.h>
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#include "buf.h"
#include "asn1.h"
#include "decode.h"
 
int
decode_snmp(u_char *buf, int len, u_char *obuf, int olen)
{
    struct buf *b, inbuf, outbuf;
    u_char *p, vers;
    int i;
 
    buf_init(&inbuf, buf, len);
    buf_init(&outbuf, obuf, olen);
    
    if (asn1_type(&inbuf) != ASN1_SEQUENCE)
        return (0);
    asn1_len(&inbuf);       /* XXX - skip sequence length */
    
    if (asn1_type(&inbuf) != ASN1_INTEGER)
        return (0);
    if (asn1_len(&inbuf) != 1)  /* XXX - check version length */
        return (0);
    buf_get(&inbuf, &vers, sizeof(vers));
    
    if (asn1_type(&inbuf) != ASN1_STRING)
        return (0);
    i = asn1_len(&inbuf);
    b = buf_tok(&inbuf, NULL, i);
    p = buf_strdup(b);
    
    buf_putf(&outbuf, "[version %d]\n%s\n", vers + 1, p);
    free(p);
    buf_end(&outbuf);
        
    return (buf_len(&outbuf));
}