/*
* RFC 1908: Coexistence between SNMPv1 and SNMPv2
*
* These convert:
*
* V1 PDUs from an ** AGENT ** to V2 PDUs for an ** MANAGER **
* V2 PDUs from an ** MANAGER ** to V1 PDUs for an ** AGENT **
*
* We will never convert V1 information from a manager into V2 PDUs. V1
* requests are always honored by V2 agents, and the responses will be
* valid V1 responses. (I think. XXXXX)
*
*/
int
snmp_coexist_V2toV1(struct snmp_pdu *PDU)
{
/* Per 3.1.1:
*/
switch (PDU->command) {
case SNMP_PDU_GET:
case SNMP_PDU_GETNEXT:
#if SNMP_PDU_SET
case SNMP_PDU_SET:
#endif
return (1);
break;
case SNMP_PDU_GETBULK:
PDU->non_repeaters = 0;
PDU->max_repetitions = 0;
PDU->command = SNMP_PDU_GETNEXT;
return (1);
break;
default:
snmplib_debug(2, "Unable to translate PDU %d to SNMPv1!\n", PDU->command);
snmp_set_api_error(SNMPERR_PDU_TRANSLATION);
return (0);
}
}
u_char *
snmp_msg_Decode(u_char * Packet, int *PacketLenP,
u_char * Community, int *CommLenP,
int *Version, struct snmp_pdu * PDU)
{
u_char *bufp;
u_char type;
bufp = asn_parse_header(Packet, PacketLenP, &type);
if (bufp == NULL) {
snmplib_debug(4, "snmp_msg_Decode:Error decoding SNMP Message Header (Header)!\n");
ASN_PARSE_ERROR(NULL);
}
if (type != (ASN_SEQUENCE | ASN_CONSTRUCTOR)) {
snmplib_debug(4, "snmp_msg_Decode:Error decoding SNMP Message Header (Header)!\n");
ASN_PARSE_ERROR(NULL);
}
bufp = asn_parse_int(bufp, PacketLenP,
&type,
(int *) Version, sizeof(*Version));
if (bufp == NULL) {
snmplib_debug(4, "snmp_msg_Decode:Error decoding SNMP Message Header (Version)!\n");
ASN_PARSE_ERROR(NULL);
}
bufp = asn_parse_string(bufp, PacketLenP, &type, Community, CommLenP);
if (bufp == NULL) {
snmplib_debug(4, "snmp_msg_Decode:Error decoding SNMP Message Header (Community)!\n");
ASN_PARSE_ERROR(NULL);
}
Community[*CommLenP] = '\0';
if ((*Version != SNMP_VERSION_1) &&
(*Version != SNMP_VERSION_2)) {
/* Don't know how to handle this one. */
snmplib_debug(4, "snmp_msg_Decode:Unable to parse Version %u\n", *Version);
snmplib_debug(4, "snmp_msg_Decode:Continuing anyway\n");
}
/* Now that we know the header, decode the PDU */
/* XXXXX -- More than one PDU? */
bufp = snmp_pdu_decode(bufp, PacketLenP, PDU);
if (bufp == NULL)
/* snmp_pdu_decode registered failure */
return (NULL);
bufp = snmp_var_DecodeVarBind(bufp, PacketLenP, &(PDU->variables), *Version);
if (bufp == NULL)
/* snmp_var_DecodeVarBind registered failure */
return (NULL);
return (u_char *) bufp;
}
u_char *
snmp_msg_Encode(u_char * Buffer, int *BufLenP,
u_char * Community, int CommLen,
int Version,
struct snmp_pdu *PDU)
{
u_char *bufp, *tmp;
u_char *PDUHeaderPtr, *VARHeaderPtr;
u_char *PDUDataStart, *VARDataStart;
u_char *MsgPtr;
int FakeArg = 1024;
snmplib_debug(4, "Buffer=%p BufLenP=%p, buflen=%d\n", Buffer, BufLenP,
*BufLenP);
/* Header for the entire thing, with a false, large length */
bufp = asn_build_header(Buffer, BufLenP,
(u_char) (ASN_SEQUENCE |
ASN_CONSTRUCTOR),
(*BufLenP));
if (bufp == NULL) {
snmplib_debug(4, "snmp_msg_Encode:Error encoding SNMP Message Header (Header)!\n");
return (NULL);
}
MsgPtr = bufp;
/* Version */
bufp = asn_build_int(bufp, BufLenP,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_INTEGER),
(int *) (&Version), sizeof(Version));
if (bufp == NULL) {
snmplib_debug(4, "snmp_msg_Encode:Error encoding SNMP Message Header (Version)!\n");
return (NULL);
}
snmplib_debug(8, "snmp_msg_Encode: Encoding community (%s) (%d)\n", Community, CommLen);
/* Community */
bufp = asn_build_string(bufp, BufLenP,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
Community, CommLen);
if (bufp == NULL) {
snmplib_debug(4, "snmp_msg_Encode:Error encoding SNMP Message Header (Community)!\n");
return (NULL);
}
/* Encode the rest. */
/* A nice header for this PDU.
* Encoded with the wrong length. We'll fix it later.
*/
snmplib_debug(8, "snmp_msg_Encode:Encoding PDU Header at 0x%p (fake len %d) (%d bytes so far)\n",
bufp, *BufLenP, *BufLenP);
PDUHeaderPtr = bufp;
bufp = asn_build_header(bufp, BufLenP,
(u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
(*BufLenP));
if (bufp == NULL)
return (NULL);
/* Encode this PDU. */
PDUDataStart = bufp;
bufp = snmp_pdu_encode(bufp, BufLenP, PDU);
if (bufp == NULL)
return (NULL); /* snmp_pdu_encode registered failure */
VARHeaderPtr = bufp;
bufp = asn_build_header(bufp, BufLenP,
(u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
FakeArg);
if (bufp == NULL)
return (NULL);
VARDataStart = bufp;
/* And build the variables */
bufp = snmp_var_EncodeVarBind(bufp, BufLenP, PDU->variables, Version);
if (bufp == NULL)
return (NULL); /* snmp_var_EncodeVarBind registered failure */
/* Cool. Now insert the appropriate lengths.
*/
#if DEBUG_MSG_ENCODE
snmplib_debug(9, "Msg: Vars returned 0x%x. PDU Started at 0x%x\n",
bufp, PDUHeaderPtr);
snmplib_debug(9, "MSG: Entire PDU length is %d (0x%x - 0x%x)\n",
(int) (bufp - PDUDataStart), PDUHeaderPtr, bufp);
#endif
tmp = asn_build_header(PDUHeaderPtr, &FakeArg,
(u_char) PDU->command,
(int) (bufp - PDUDataStart));
/* Length of the PDU and Vars */
if (tmp == NULL)
return (NULL);
#if DEBUG_MSG_ENCODE
snmplib_debug(9, "MSG: Entire message length is %d (0x%x - 0x%x)\n",
(int) (bufp - MsgPtr), MsgPtr, bufp);
#endif
tmp = asn_build_header(Buffer,
&FakeArg,
(u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
(bufp - MsgPtr)); /* Length of everything */
if (tmp == NULL)
return (NULL);
tmp = asn_build_header(VARHeaderPtr,
&FakeArg,
(u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
(bufp - VARDataStart)); /* Length of everything */
if (tmp == NULL)
return (NULL);
*BufLenP = (bufp - Buffer);
return (u_char *) bufp;
}
static int
parse_subtree(struct snmp_mib_tree *subtree, char *input, oid *output, int *out_len)
{
char buf[128], *to = buf;
u_int subid = 0;
struct snmp_mib_tree *tp;
/*
* No empty strings. Can happen if there is a trailing '.' or two '.'s
* in a row, i.e. "..".
*/
if ((*input == '\0') ||
(*input == '.'))
return (0);
if (xisdigit(*input)) {
/*
* Read the number, then try to find it in the subtree.
*/
while (xisdigit(*input)) {
subid *= 10;
subid += *input++ - '0';
}
for (tp = subtree; tp; tp = tp->next_peer) {
if (tp->subid == subid)
goto found;
}
tp = NULL;
} else {
/*
* Read the name into a buffer.
*/
while ((*input != '\0') &&
(*input != '.')) {
*to++ = *input++;
}
*to = '\0';
/*
* Find the name in the subtree;
*/
for (tp = subtree; tp; tp = tp->next_peer) {
if (lc_cmp(tp->label, buf) == 0) {
subid = tp->subid;
goto found;
}
}
/*
* If we didn't find the entry, punt...
*/
if (tp == NULL) {
snmplib_debug(0, "sub-identifier not found: %s\n", buf);
return (0);
}
}
found:
if (subid > (u_int) MAX_SUBID) {
snmplib_debug(0, "sub-identifier too large: %s\n", buf);
return (0);
}
if ((*out_len)-- <= 0) {
snmplib_debug(0, "object identifier too long\n");
return (0);
}
*output++ = subid;
if (*input != '.')
return (1);
if ((*out_len =
parse_subtree(tp ? tp->child_list : NULL, ++input, output, out_len)) == 0)
return (0);
return (++*out_len);
}
/* 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 = NULL, **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)
return (NULL);
if (VarBindType != (u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR)) {
snmp_set_api_error(SNMPERR_PDU_PARSE);
return (NULL);
}
#ifdef DEBUG_VARS_DECODE
printf("VARS: All Variable length %d\n", AllVarLen);
#endif
#define PARSE_ERROR { snmp_var_free(Var); return(NULL); }
/* 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)
PARSE_ERROR;
/* 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);
PARSE_ERROR;
}
#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)
PARSE_ERROR;
if (VarBindType != (u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OBJECT_ID)) {
snmp_set_api_error(SNMPERR_PDU_PARSE);
PARSE_ERROR;
}
#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)
PARSE_ERROR;
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 *) xmalloc(sizeof(int));
if (Var->val.integer == NULL) {
snmp_set_api_error(SNMPERR_OS_ERR);
PARSE_ERROR;
}
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 *) xmalloc(sizeof(u_int));
if (Var->val.integer == NULL) {
snmp_set_api_error(SNMPERR_OS_ERR);
PARSE_ERROR;
}
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 *) xmalloc((unsigned) Var->val_len);
if (Var->val.string == NULL) {
snmp_set_api_error(SNMPERR_OS_ERR);
PARSE_ERROR;
}
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 *) xmalloc((unsigned) Var->val_len);
if (Var->val.integer == NULL) {
snmp_set_api_error(SNMPERR_OS_ERR);
PARSE_ERROR;
}
/* Only copy if we successfully decoded something */
if (bufp) {
xmemcpy((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:
break;
case SMI_COUNTER64:
snmplib_debug(2, "Unable to parse type SMI_COUNTER64!\n");
snmp_set_api_error(SNMPERR_UNSUPPORTED_TYPE);
PARSE_ERROR;
default:
snmplib_debug(2, "bad type returned (%x)\n", Var->type);
snmp_set_api_error(SNMPERR_PDU_PARSE);
PARSE_ERROR;
} /* End of var type switch */
if (bufp == NULL)
PARSE_ERROR;
#ifdef DEBUG_VARS_DECODE
printf("VARS: Adding to list.\n");
#endif
/* Add variable to the list */
*VarLastP = Var;
VarLastP = &(Var->next_variable);
}
#undef PARSE_ERROR
return (bufp);
}
/* Build a variable binding.
*
* RFC 1905: Protocol Operations for SNMPv2
*
* VarBind ::=
* SEQUENCE {
* name ObjectName
* CHOICE {
* value ObjectSyntax
* unSpecified NULL
* noSuchObject[0] NULL
* noSuchInstance[1] NULL
* endOfMibView[2] NULL
* }
* }
*/
u_char *
snmp_var_EncodeVarBind(u_char * Buffer, int *BufLenP,
variable_list * VarList,
int Version)
{
struct variable_list *Vars;
u_char *bufp;
u_char *HeaderStart;
u_char *HeaderEnd;
int FakeArg = *BufLenP;
bufp = Buffer;
for (Vars = VarList; Vars; Vars = Vars->next_variable) {
/* Build the header for this variable
*
* Use Maximum size.
*/
HeaderStart = bufp;
HeaderEnd = asn_build_header(HeaderStart, BufLenP,
(u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
FakeArg);
if (HeaderEnd == NULL)
return (NULL);
/* Now, let's put the Object Identifier into the buffer */
bufp = asn_build_objid(HeaderEnd, BufLenP,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OBJECT_ID),
Vars->name, Vars->name_length);
if (bufp == NULL)
return (NULL);
/* Now put the data in */
switch (Vars->type) {
case ASN_INTEGER:
bufp = asn_build_int(bufp,
BufLenP, Vars->type,
(int *) Vars->val.integer, Vars->val_len);
break;
case SMI_COUNTER32:
case SMI_GAUGE32:
/* case SMI_UNSIGNED32: */
case SMI_TIMETICKS:
bufp = asn_build_unsigned_int(bufp, BufLenP,
Vars->type,
(u_int *) Vars->val.integer, Vars->val_len);
break;
case ASN_OCTET_STR:
case SMI_IPADDRESS:
case SMI_OPAQUE:
bufp = asn_build_string(bufp, BufLenP, Vars->type,
Vars->val.string, Vars->val_len);
break;
case ASN_OBJECT_ID:
bufp = asn_build_objid(bufp, BufLenP, Vars->type,
(oid *) Vars->val.objid, Vars->val_len / sizeof(oid));
break;
case SMI_NOSUCHINSTANCE:
case SMI_NOSUCHOBJECT:
case SMI_ENDOFMIBVIEW:
if (Version == SNMP_VERSION_1) {
/* SNMP Version 1 does not support these error codes. */
bufp = asn_build_null(bufp, BufLenP, SMI_NOSUCHOBJECT);
} else {
bufp = asn_build_exception(bufp, BufLenP, Vars->type);
}
break;
case ASN_NULL:
bufp = asn_build_null(bufp, BufLenP, Vars->type);
break;
case SMI_COUNTER64:
snmplib_debug(2, "Unable to encode type SMI_COUNTER64!\n");
/* Fall through */
default:
snmp_set_api_error(SNMPERR_UNSUPPORTED_TYPE);
return (NULL);
}
/* ASSERT: bufp should now point to the next valid byte. */
if (bufp == NULL)
return (NULL);
/* Rebuild the header with the appropriate length */
HeaderEnd = asn_build_header(HeaderStart, &FakeArg,
(u_char) (ASN_SEQUENCE | ASN_CONSTRUCTOR),
(bufp - HeaderEnd));
/* Returns NULL */
if (HeaderEnd == NULL)
return (NULL);
}
/* or the end of the entire thing */
return (bufp);
}
