50 lines · c
1#include <linux/zutil.h>2#include <linux/errno.h>3#include <linux/slab.h>4#include <linux/vmalloc.h>5 6/* Utility function: initialize zlib, unpack binary blob, clean up zlib,7 * return len or negative error code.8 */9int zlib_inflate_blob(void *gunzip_buf, unsigned int sz,10 const void *buf, unsigned int len)11{12 const u8 *zbuf = buf;13 struct z_stream_s *strm;14 int rc;15 16 rc = -ENOMEM;17 strm = kmalloc(sizeof(*strm), GFP_KERNEL);18 if (strm == NULL)19 goto gunzip_nomem1;20 strm->workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);21 if (strm->workspace == NULL)22 goto gunzip_nomem2;23 24 /* gzip header (1f,8b,08... 10 bytes total + possible asciz filename)25 * expected to be stripped from input26 */27 strm->next_in = zbuf;28 strm->avail_in = len;29 strm->next_out = gunzip_buf;30 strm->avail_out = sz;31 32 rc = zlib_inflateInit2(strm, -MAX_WBITS);33 if (rc == Z_OK) {34 rc = zlib_inflate(strm, Z_FINISH);35 /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */36 if (rc == Z_STREAM_END)37 rc = sz - strm->avail_out;38 else39 rc = -EINVAL;40 zlib_inflateEnd(strm);41 } else42 rc = -EINVAL;43 44 kfree(strm->workspace);45gunzip_nomem2:46 kfree(strm);47gunzip_nomem1:48 return rc; /* returns Z_OK (0) if successful */49}50