---
name: "packet.application.rpc"
section: "3"
platform: "linux"
package: "nfstest"
version: "3.2-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/packet.application.rpc"
---

# packet.application.rpc(3)

RPC module

## NAME

packet.application.rpc - RPC module

## DESCRIPTION

Decode RPC layer.

## CLASSES

### class Header(baseobj.BaseObj)

```
Header object
```

**Methods defined here:** ---------------------

**\_\_init\_\_(self, size, last\_fragment)** Constructor which takes the size and last fragment as inputs

### class Prog(baseobj.BaseObj)

```
Prog object
```

**Methods defined here:** ---------------------

**\_\_init\_\_(self, unpack)** Constructor which takes the Unpack object as input

### class RPC(packet.application.gss.GSS)

```
RPC object
Usage:
    from packet.application.rpc import RPC
    # Decode the RPC header
    x = RPC(pktt_obj, proto=6)
    # Decode NFS layer
    nfs = x.decode_payload()
Object definition:
RPC(
    [
        # If TCP
        fragment_hdr = Header(
            last_fragment = int,
            size          = int,
        ),
    ]
    xid  = int,
    type = int,
    [
        # If type == 0 (RPC call)
        rpc_version = int,
        program     = int,
        version     = int,
        procedure   = int,
        credential  = Credential(
            data   = string,
            flavor = int,
            size   = int,
        ),
        verifier = Credential(
            data   = string,
            flavor = int,
            size   = int,
        ),
    ] | [
        # If type == 1 (RPC reply)
        reply_status = int,
        [
            # If reply_status == 0
            verifier = Credential(
                data   = string,
                flavor = int,
                size   = int,
            ),
            accepted_status = int,
            [
                # If accepted_status == 2
                prog_mismatch = Prog(
                    low  = int,
                    high = int,
                )
            ]
        ] | [
            # If reply_status != 0
            rejected_status = int,
            [
                # If rejected_status == 0
                prog_mismatch = Prog(
                    low  = int,
                    high = int,
                )
            ] | [
                # If rejected_status != 0
                auth_status = int,
            ]
        ]
    ]
    psize = int,    # payload data size
    [data = string] # raw data of payload if unable to decode
)
```

**Methods defined here:** ---------------------

**\_\_bool\_\_(self)** Truth value testing for the built-in operation bool()

**\_\_init\_\_(self, pktt, proto=17, state=True)** Constructor

Initialize object's private data.

- **pktt:**

  Packet trace object (packet.pktt.Pktt) so this layer has access to the parent layers.

- **proto:**

  Transport layer protocol.

- **state:**

  Save call state. \[default: True\]

**\_\_str\_\_(self)** String representation of object

The representation depends on the verbose level set by debug\_repr(). If set to 0 the generic object representation is returned. If set to 1 the representation of the object is:\
     'RPC call   program: 100003, version: 4, procedure: 0, xid: 0xe37d3d5 '

If set to 2 the representation of the object is as follows:\
     'CALL(0), program: 100003, version: 4, procedure: 0, xid: 0xe37d3d5'

**decode\_payload(self)** Decode RPC load

For RPC calls it is easy to decide if the RPC payload is an NFS packet since the RPC program is in the RPC header, which for NFS the program number is 100003. On the other hand, for RPC replies the RPC header does not have any information on what the payload is, so the transaction ID (xid) is used to map the replies to their calls and thus deciding if RPC payload is an NFS packet or not. This is further complicated when trying to decode callbacks, since the program number for callbacks could be any number in the transient program range \[0x40000000, 0x5FFFFFFF\]. Therefore, any program number in the transient range is considered a callback and if the decoding succeeds then this is an NFS callback, otherwise it is not.

Since the RPC replies do not contain any information about what type of payload, when they are decoded correctly as NFS replies this information is inserted in the RPC (pkt.rpc) object. This information includes program number, RPC version, procedure number as well as the call\_index which is the packet index of its corresponding call for each reply.

x.pkt.nfs = \<NFSobject\>

where \<NFSobject\> is an object of type COMPOUND4args or COMPOUND4res

class COMPOUND4args(\
     tag          = string,\
     minorversion = int,\
     argarray     = \[\], )

The argarray is a list of nfs\_argop4 objects:

class nfs\_argop4(\
     argop = int,\
     \[\<opobject\> = \<opargobject\>,\] )

where opobject could be opsequence, opgetattr, etc., and opargobject is the object which has the arguments for the given opobject, e.g., SEQUENCE4args, GETATTR4args, etc.

class COMPOUND4res(\
     tag      = string,\
     status   = int,\
     resarray = \[\], )

The resarray is a list of nfs\_resop4 objects:

class nfs\_resop4(\
     resop = int,\
     \[\<opobject\> = \<opresobject\>,\] )

where opobject could be opsequence, opgetattr, etc., and opresobject is the object which has the results for the given opobject, e.g., SEQUENCE4res, GETATTR4res, etc.

### class accept\_stat\_enum(packet.utils.Enum)

```
enum accept_stat
```

### class auth\_stat\_enum(packet.utils.Enum)

```
enum auth_stat
```

### class reject\_stat\_enum(packet.utils.Enum)

```
enum reject_stat
```

## SEE ALSO

**[baseobj(3)](/baseobj/3.md),** **[packet.application.gss(3)](/packet.application.gss/3.md),** **[packet.application.rpc\_const(3)](/packet.application.rpc_const/3.md),** **[packet.application.rpc\_creds(3)](/packet.application.rpc_creds/3.md),** **[packet.nfs.mount3(3)](/packet.nfs.mount3/3.md),** **[packet.nfs.nfs(3)](/packet.nfs.nfs/3.md),** **[packet.nfs.nlm4(3)](/packet.nfs.nlm4/3.md),** **[packet.nfs.portmap2(3)](/packet.nfs.portmap2/3.md),** **[packet.utils(3)](/packet.utils/3.md)**

## BUGS

No known bugs.

## AUTHOR

Jorge Mora (mora@netapp.com)