lib/decompress_inflate.c

Source file repositories/reference/linux-study-clean/lib/decompress_inflate.c

File Facts

System
Linux kernel
Corpus path
lib/decompress_inflate.c
Extension
.c
Size
4873 bytes
Lines
220
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: implementation source
Status
source implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

void(*error)(char *x)) {
	u8 *zbuf;
	struct z_stream_s *strm;
	int rc;

	rc = -1;
	if (flush) {
		out_len = 0x8000; /* 32 K */
		out_buf = malloc(out_len);
	} else {
		if (!out_len)
			out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */
	}
	if (!out_buf) {
		error("Out of memory while allocating output buffer");
		goto gunzip_nomem1;
	}

	if (buf)
		zbuf = buf;
	else {
		zbuf = malloc(GZIP_IOBUF_SIZE);
		len = 0;
	}
	if (!zbuf) {
		error("Out of memory while allocating input buffer");
		goto gunzip_nomem2;
	}

	strm = malloc(sizeof(*strm));
	if (strm == NULL) {
		error("Out of memory while allocating z_stream");
		goto gunzip_nomem3;
	}

	strm->workspace = malloc(flush ? zlib_inflate_workspacesize() :
#ifdef CONFIG_ZLIB_DFLTCC
	/* Always allocate the full workspace for DFLTCC */
				 zlib_inflate_workspacesize());
#else
				 sizeof(struct inflate_state));
#endif
	if (strm->workspace == NULL) {
		error("Out of memory while allocating workspace");
		goto gunzip_nomem4;
	}

	if (!fill)
		fill = nofill;

	if (len == 0)
		len = fill(zbuf, GZIP_IOBUF_SIZE);

	/* verify the gzip header */
	if (len < 10 ||
	   zbuf[0] != 0x1f || zbuf[1] != 0x8b || zbuf[2] != 0x08) {
		if (pos)
			*pos = 0;
		error("Not a gzip file");
		goto gunzip_5;
	}

	/* skip over gzip header (1f,8b,08... 10 bytes total +
	 * possible asciz filename)
	 */
	strm->next_in = zbuf + 10;
	strm->avail_in = len - 10;
	/* skip over asciz filename */
	if (zbuf[3] & 0x8) {
		do {
			/*
			 * If the filename doesn't fit into the buffer,
			 * the file is very probably corrupt. Don't try
			 * to read more data.
			 */
			if (strm->avail_in == 0) {
				error("header error");
				goto gunzip_5;
			}
			--strm->avail_in;
		} while (*strm->next_in++);
	}

	strm->next_out = out_buf;
	strm->avail_out = out_len;

	rc = zlib_inflateInit2(strm, -MAX_WBITS);

#ifdef CONFIG_ZLIB_DFLTCC
	/* Always keep the window for DFLTCC */

Annotation

Implementation Notes