Flat-memory backing for the shared unarchiver read seam. More...

#include "unarch_io.h"
#include <string.h>

Include dependency graph for unarch_io.c:

Functions
size_t	unarch_mem_read (void ctx, uint64_t offset, void buf, size_t len)
	unarch_read_fn over a flat unarch_mem_t view.

Detailed Description

Flat-memory backing for the shared unarchiver read seam.

Tag: [Ring 4 / Domain] {World: NS}

The one trivial unarch_read_fn implementation everybody shares: a bounds-clamped copy out of a unarch_mem_t view. Reads never touch a byte outside [base, base + len) regardless of the (untrusted) offset and length arguments, so the wrapped-open paths can point it at a decompressed arena without further guarding.

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: Version 0.1.0

Definition in file unarch_io.c.

Function Documentation

◆ unarch_mem_read()

size_t unarch_mem_read	(	void *	ctx,
		uint64_t	offset,
		void *	buf,
		size_t	len )

nodiscard

unarch_read_fn over a flat unarch_mem_t view.

Serves [offset, offset + len) clamped to the view's bounds by plain copy. Reads at or past the end return 0 (EOF); a NULL context or view base also returns 0, which every decoder treats as a failed read (fail-closed).

Parameters

[in]	ctx	The unarch_mem_t view (may be NULL: reads 0).
[in]	offset	Absolute byte offset within the view.
[out]	buf	Destination buffer (`len` writable bytes, non-NULL).
[in]	len	Bytes requested.

Returns: Bytes actually copied.

Return values

0	NULL view / NULL destination, EOF, or a zero-length request.

Precondition: buf holds len writable bytes when len > 0.; The view's base/len describe readable storage.

Postcondition: At most len bytes of buf are written; nothing else changes.; The view itself is never modified (pure read).

Note: Thread-safe: pure read of an immutable view.

See also: unarch_mem_t

Since: Version 0.1.0

Definition at line 24 of file unarch_io.c.

References unarch_mem_t::base, unarch_mem_t::len, and memcpy().

Referenced by internal_open_unwrapped().

Functions

Detailed Description

Function Documentation

◆ unarch_mem_read()