include/uapi/linux/erspan.h

File Facts

System

Linux kernel

Corpus path

include/uapi/linux/erspan.h

Extension

.h

Size

1074 bytes

Lines

53

Domain

Core OS

Bucket

Core Kernel Interface

Inferred role

Core OS: implementation source

Status

source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/types.h
• asm/byteorder.h

Detected Declarations

• struct erspan_md2
• struct erspan_metadata

Annotated Snippet

struct erspan_md2 {
	__be32 timestamp;
	__be16 sgt;	/* security group tag */
#if defined(__LITTLE_ENDIAN_BITFIELD)
	__u8	hwid_upper:2,
		ft:5,
		p:1;
	__u8	o:1,
		gra:2,
		dir:1,
		hwid:4;
#elif defined(__BIG_ENDIAN_BITFIELD)
	__u8	p:1,
		ft:5,
		hwid_upper:2;
	__u8	hwid:4,
		dir:1,
		gra:2,
		o:1;
#else
#error "Please fix <asm/byteorder.h>"
#endif
};

struct erspan_metadata {
	int version;
	union {
		__be32 index;		/* Version 1 (type II)*/
		struct erspan_md2 md2;	/* Version 2 (type III) */
	} u;
};

#endif /* _UAPI_ERSPAN_H */

Annotation

• Immediate include surface: `linux/types.h`, `asm/byteorder.h`.
• Detected declarations: `struct erspan_md2`, `struct erspan_metadata`.
• Atlas domain: Core OS / Core Kernel Interface.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.