/* Parse all Vars from the buffer */
u_char *snmp_var_DecodeVarBind(u_char *Buffer, int *BufLen,
struct variable_list **VarP,
int Version)
{
struct variable_list *Var, **VarLastP;
u_char *bufp, *tmp;
u_char VarBindType;
u_char *DataPtr;
int DataLen;
oid TmpBuf[MAX_NAME_LEN];
int AllVarLen = *BufLen;
int ThisVarLen = 0;
VarLastP = VarP;
#ifdef DEBUG_VARS_DECODE
printf("VARS: Decoding buffer of length %d\n", *BufLen);
#endif
/* Now parse the variables */
bufp = asn_parse_header(Buffer, &AllVarLen, &VarBindType);
if (bufp == NULL)
ASN_PARSE_ERROR(NULL);
if (VarBindType != (u_char)(ASN_SEQUENCE | ASN_CONSTRUCTOR)) {
snmp_set_api_error(SNMPERR_PDU_PARSE);
ASN_PARSE_ERROR(NULL);
}
#ifdef DEBUG_VARS_DECODE
printf("VARS: All Variable length %d\n", AllVarLen);
#endif
/* We know how long the variable list is. Parse it. */
while ((int)AllVarLen > 0) {
/* Create a new variable */
Var = snmp_var_new(NULL, MAX_NAME_LEN);
if (Var == NULL)
return(NULL);
/* Parse the header to find out the length of this variable. */
ThisVarLen = AllVarLen;
tmp = asn_parse_header(bufp, &ThisVarLen, &VarBindType);
if (tmp == NULL)
ASN_PARSE_ERROR(NULL);
/* Now that we know the length , figure out how it relates to
* the entire variable list
*/
AllVarLen = AllVarLen - (ThisVarLen + (tmp - bufp));
bufp = tmp;
/* Is it valid? */
if (VarBindType != (u_char)(ASN_SEQUENCE | ASN_CONSTRUCTOR)) {
snmp_set_api_error(SNMPERR_PDU_PARSE);
ASN_PARSE_ERROR(NULL);
}
#ifdef DEBUG_VARS_DECODE
printf("VARS: Header type 0x%x (%d bytes left)\n", VarBindType, ThisVarLen);
#endif
/* Parse the OBJID */
bufp = asn_parse_objid(bufp, &ThisVarLen, &VarBindType,
Var->name, &(Var->name_length));
if (bufp == NULL)
ASN_PARSE_ERROR(NULL);
if (VarBindType != (u_char)(ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OBJECT_ID)) {
snmp_set_api_error(SNMPERR_PDU_PARSE);
ASN_PARSE_ERROR(NULL);
}
#ifdef DEBUG_VARS_DECODE
printf("VARS: Decoded OBJID (%d bytes). (%d bytes left)\n",
Var->name_length, ThisVarLen);
#endif
/* Keep a pointer to this object */
DataPtr = bufp;
DataLen = ThisVarLen;
/* find out type of object */
bufp = asn_parse_header(bufp, &ThisVarLen, &(Var->type));
if (bufp == NULL)
ASN_PARSE_ERROR(NULL);
ThisVarLen = DataLen;
#ifdef DEBUG_VARS_DECODE
printf("VARS: Data type %d\n", Var->type);
#endif
/* Parse the type */
switch((short)Var->type){
case ASN_INTEGER:
Var->val.integer = (int *)malloc(sizeof(int));
if (Var->val.integer == NULL) {
snmp_set_api_error(SNMPERR_OS_ERR);
return(NULL);
}
Var->val_len = sizeof(int);
bufp = asn_parse_int(DataPtr, &ThisVarLen,
&Var->type, (int *)Var->val.integer,
Var->val_len);
#ifdef DEBUG_VARS_DECODE
printf("VARS: Decoded integer '%d' (%d bytes left)\n",
*(Var->val.integer), ThisVarLen);
#endif
break;
case SMI_COUNTER32:
case SMI_GAUGE32:
/* case SMI_UNSIGNED32: */
case SMI_TIMETICKS:
Var->val.integer = (int *)malloc(sizeof(u_int));
if (Var->val.integer == NULL) {
snmp_set_api_error(SNMPERR_OS_ERR);
return(NULL);
}
Var->val_len = sizeof(u_int);
bufp = asn_parse_unsigned_int(DataPtr, &ThisVarLen,
&Var->type, (u_int *)Var->val.integer,
Var->val_len);
#ifdef DEBUG_VARS_DECODE
printf("VARS: Decoded timeticks '%d' (%d bytes left)\n",
*(Var->val.integer), ThisVarLen);
#endif
break;
case ASN_OCTET_STR:
case SMI_IPADDRESS:
case SMI_OPAQUE:
Var->val_len = *&ThisVarLen; /* String is this at most */
Var->val.string = (u_char *)malloc((unsigned)Var->val_len);
if (Var->val.string == NULL) {
snmp_set_api_error(SNMPERR_OS_ERR);
return(NULL);
}
bufp = asn_parse_string(DataPtr, &ThisVarLen,
&Var->type, Var->val.string,
&Var->val_len);
#ifdef DEBUG_VARS_DECODE
printf("VARS: Decoded string '%s' (length %d) (%d bytes left)\n",
(Var->val.string), Var->val_len, ThisVarLen);
#endif
break;
case ASN_OBJECT_ID:
Var->val_len = MAX_NAME_LEN;
bufp = asn_parse_objid(DataPtr, &ThisVarLen,
&Var->type, TmpBuf, &Var->val_len);
Var->val_len *= sizeof(oid);
Var->val.objid = (oid *)malloc((unsigned)Var->val_len);
if (Var->val.integer == NULL) {
snmp_set_api_error(SNMPERR_OS_ERR);
return(NULL);
}
/* Only copy if we successfully decoded something */
if (bufp) {
memcpy((char *)Var->val.objid, (char *)TmpBuf, Var->val_len);
}
#ifdef DEBUG_VARS_DECODE
printf("VARS: Decoded OBJID (length %d) (%d bytes left)\n",
Var->val_len, ThisVarLen);
#endif
break;
case ASN_NULL:
case SMI_NOSUCHINSTANCE:
case SMI_NOSUCHOBJECT:
case SMI_ENDOFMIBVIEW:
Var->val_len = 0;
Var->val.objid = NULL;
bufp = asn_parse_null(DataPtr, &ThisVarLen, &Var->type);
#ifdef DEBUG_VARS_DECODE
printf("VARS: Decoded ASN_NULL (length %d) (%d bytes left)\n",
Var->val_len, ThisVarLen);
#endif
break;
case SMI_COUNTER64:
#ifdef STDERR_OUTPUT
fprintf(stderr, WIDE("Unable to parse type SMI_COUNTER64!\n"));
#endif
snmp_set_api_error(SNMPERR_UNSUPPORTED_TYPE);
return(NULL);
break;
default:
#ifdef STDERR_OUTPUT
fprintf(stderr, WIDE("bad type returned (%x)\n"), Var->type);
#endif
snmp_set_api_error(SNMPERR_PDU_PARSE);
return(NULL);
break;
} /* End of var type switch */
/* Why is this here? XXXXX */
if (bufp == NULL)
return(NULL);
#ifdef DEBUG_VARS_DECODE
printf("VARS: Adding to list of decoded variables. (%d bytes remain.)\n", AllVarLen);
#endif
/* Add variable to the list */
*VarLastP = Var;
VarLastP = &(Var->next_variable);
}
return(bufp);
}
char *
snmp_parse_trap(u_char * trapdata, /* IN - actual trap data from packet */
unsigned datalen, /* IN - length of trapdata */
struct trap_info * trapInfo) /* IN/OUT - struct to fill in */
{
u_char * more; /* pointer to next unparsed PDU data */
u_char * nextVar; /* pointer to next unparsed TRAP variable */
unsigned left; /* length of more */
long version; /* SNMP version, always v1 */
u_char type; /* data types for checking */
u_char * varValPtr;
int vars_in_struct;
struct trapVar * vars; /* trap variables data structures */
u_long trapType;
unsigned length; /* scratch for passing to asn1 */
/* do some basic setup of the passed data structures */
vars_in_struct = trapInfo->trapVars;
trapInfo->trapVars = 0; /* bump later if vars are present */
left = datalen;
more = snmp_auth_parse(trapdata, &left, (u_char*)trapInfo->community,
(unsigned*)&trapInfo->commLen, &version);
if (!more)
return "community parse";
more = asn_parse_header(more, &left, &type);
if (!more || type != TRP_REQ_MSG)
return "trap pdu header";
more = asn_parse_objid(more, &left, &type, &trapInfo->objId[0],
(unsigned*)&trapInfo->objLen);
if (!more || type != ASN_OBJECT_ID)
return "sys ObjId";
length = 4; /* number of bytes in IP address buffer */
more = asn_parse_string(more, &left, &type,
(u_char*)(&trapInfo->agent_ip), &length);
if (!more || type != IPADDRESS)
return "agent's IP address";
more = asn_parse_int(more, &left, &type, (long*)&trapType, sizeof(long));
if (!more || type != ASN_INTEGER || trapType > 6)
return "trap type";
trapInfo->trapType = trapType;
more = asn_parse_int(more, &left, &type, (long*)&trapType, sizeof(long));
if (!more || type != ASN_INTEGER)
return "specific type";
trapInfo->trapSpecific = trapType;
more = asn_parse_int(more, &left, &type, (long*)&trapInfo->time, sizeof(long));
if (!more || type != TIMETICKS)
return "timestamp";
if (!left) /* no variables in trap ? */
return NULL;
/* rest of packet is a sequence of variables */
more = asn_parse_header(more, &left, &type); /* strip off leading SEQ */
if (!more || type != SEQUENCE)
return "trap vars header";
vars = trapInfo->vars; /* set pointer array to receive variables data */
while (left) /* keep parsing & counting vars as long as there's data */
{
/* extract variable info for this var */
length = left; /* number of valid bytes left in packet buffer */
varNameLen = MAX_OID_LEN ; /* define the max size of varName */
nextVar = snmp_parse_var_op(more, varName, &varNameLen, &varType,
&varLen, &varValPtr, &left);
if (!nextVar) /* quit if parse failed */
return ("var_op header");
/* extract the variable's value; pointed to by varValPtr: */
length -= more - nextVar; /* deduct size of header -> max. length of var */
switch (varType)
{
case ASN_INTEGER:
case GAUGE:
case COUNTER:
case TIMETICKS:
varLen = sizeof(long); /* size required by asn_parse_int() */
nextVar = asn_parse_int(varValPtr, &length, &varType,
(long *)(&varVal[0]), varLen);
break;
case ASN_OCTET_STR:
case IPADDRESS:
case OPAQUE:
varLen = MAX_TRAP_VAR;
nextVar = asn_parse_string(varValPtr, &length, &varType,
varVal, &varLen);
break;
case ASN_OBJECT_ID:
varLen = MAX_TRAP_VAR;
nextVar = asn_parse_objid(varValPtr, &length, &varType,
(oid *)(&varVal[0]), &varLen);
break;
case ASN_NULL:
nextVar = asn_parse_null(varValPtr, &length, &varType);
break;
default:
SNMPERROR("wrong type");
return NULL;
}
if (!nextVar)
return("variable");
/* if another trap variable info slot is available, fill it in */
if (trapInfo->trapVars <= vars_in_struct)
{
oidcpy(vars->varName, varName, varNameLen);
if (vars->varBufLen <= varLen) /* need to truncate? */
vars->varValLen = vars->varBufLen-1;
else /* we have room for the full variable data field */
vars->varValLen = varLen;
MEMCPY(vars->varBuf, varVal, vars->varValLen);
vars->varNameLen = varNameLen;
vars->varType = varType;
vars++; /* point to next variable info structure */
}
trapInfo->trapVars++; /* another var */
more = nextVar; /* bump pointer to pdu */
}
return NULL;
}
