Mach messages: doubleagent_mig

Message catalog and dispatch · All subsystem ranges · Kernel entry map

osfmk/mach/doubleagent_mig.defs. Service/callback interface outside the ordinary kernel kobject table. Follow local sender/receiver evidence; external service bodies are not supplied by the declaration. Registration evidence: mig_e.

Reading these entries

IDs are computed from the explicit preprocessing profiles in the catalog guide, counting both routines and skip slots. They are not discovered from a running kernel. Each entry retains all observed names/declaration locations; the displayed fields come from the first non-skipped profile. Alternative declarations can have different fields. simpleroutine is one-way at the MIG interface level.

An interface contract block quotes the adjacent local .defs comment with whitespace normalized. Mechanism paragraphs explain selected implementation decisions. Local body links and call names identify implementation evidence; syntactic call lists are reading aids, not a proof that every listed call executes on every path. Short complete implementation bodies are included where especially useful.

Complete routine and reserved-slot catalog

6300: doubleagent_lookup_xattr

Request lookup of a mediated extended attribute from the external service.

Mechanism: The caller opens the AppleDouble backing file with a shared lock, creates a fileport, drops its vnode iocount and asks the daemon for offset/length. It maps transport failure to EIO, reacquires a vnode reference on success and performs the actual VNOP_READ locally. The daemon parses metadata; file bytes and uio accounting remain on the kernel path. Local path.

Declarations: doubleagent_lookup_xattr (server64, server32, client64, client32, libsyscall64, sender64, local64).

Fields after preprocessing (server64):

routine doubleagent_lookup_xattr(
    server : mach_port_t;
    in file_port : mach_port_move_send_t;
    in file_size : int64_t;
    in name : xattrname;
    out err : int;
    out value_offset : uint64_t;
    out value_length : uint64_t
);

Implementation boundary: no same-symbol receiver body was resolved in the indexed local C/C++ implementation files. Local source occurrences to follow: bsd/vfs/vfs_xattr.c:1690. These may be senders, wrappers or declarations; they do not establish a local receiver.

6301: doubleagent_allocate_xattr

Request allocation/storage for a mediated extended attribute.

Mechanism: Opens/creates the backing file with an exclusive lock, exports a fileport and asks the daemon to allocate metadata for the name/length/options. After successful response and vnode reacquisition, the kernel adjusts the uio offset and writes bytes locally. A daemon allocation can precede a later local write failure; this is not a single rollback transaction. Local path.

Declarations: doubleagent_allocate_xattr (server64, server32, client64, client32, libsyscall64, sender64, local64).

Fields after preprocessing (server64):

routine doubleagent_allocate_xattr(
    server : mach_port_t;
    in file_port : mach_port_move_send_t;
    in file_size : int64_t;
    in name : xattrname;
    in size : uint64_t;
    in options : uint32_t;
    out err : int;
    out value_offset : uint64_t
);

Implementation boundary: no same-symbol receiver body was resolved in the indexed local C/C++ implementation files. Local source occurrences to follow: bsd/vfs/vfs_xattr.c:1957. These may be senders, wrappers or declarations; they do not establish a local receiver.

6302: doubleagent_list_xattrs

Request the names of mediated extended attributes.

Mechanism: Exports the backing file capability and receives a fixed-format result containing names. On successful RPC/error status, reacquires the vnode, checks caller uio capacity and copies names; local copy errors remain possible after the daemon completed. The daemon's AppleDouble parsing is external. Local path.

Declarations: doubleagent_list_xattrs (server64, server32, client64, client32, libsyscall64, sender64, local64).

Fields after preprocessing (server64):

routine doubleagent_list_xattrs(
    server : mach_port_t;
    in file_port : mach_port_move_send_t;
    in file_size : int64_t;
    out err : int;
    out result : listxattrs_result_t
);

Implementation boundary: no same-symbol receiver body was resolved in the indexed local C/C++ implementation files. Local source occurrences to follow: bsd/vfs/vfs_xattr.c:1787. These may be senders, wrappers or declarations; they do not establish a local receiver.

6303: doubleagent_remove_xattr

Request removal of a mediated extended attribute.

Mechanism: Sends the backing file capability/name under the caller's exclusive-file operation and receives status plus an empty-file indication. After successful response and vnode reacquisition, the kernel removes the backing file when empty or closes it otherwise. The RPC result and later local cleanup are separate operations. Local path.

Declarations: doubleagent_remove_xattr (server64, server32, client64, client32, libsyscall64, sender64, local64).

Fields after preprocessing (server64):

routine doubleagent_remove_xattr(
    server : mach_port_t;
    in file_port : mach_port_move_send_t;
    in file_size : int64_t;
    in name : xattrname;
    out err : int;
    out is_empty : boolean_t
);

Implementation boundary: no same-symbol receiver body was resolved in the indexed local C/C++ implementation files. Local source occurrences to follow: bsd/vfs/vfs_xattr.c:2061. These may be senders, wrappers or declarations; they do not establish a local receiver.