#include <linux/zutil.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/vmalloc.h> /* Utility function: initialize zlib, unpack binary blob, clean up zlib, * return len or negative error code. */ int zlib_inflate_blob(void *gunzip_buf, unsigned int sz, const void *buf, unsigned int len) { const u8 *zbuf = buf; struct z_stream_s *strm; int rc; rc = -ENOMEM; strm = kmalloc(sizeof(*strm), GFP_KERNEL); if (strm == NULL) goto gunzip_nomem1; strm->workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); if (strm->workspace == NULL) goto gunzip_nomem2; /* gzip header (1f,8b,08... 10 bytes total + possible asciz filename) * expected to be stripped from input */ strm->next_in = zbuf; strm->avail_in = len; strm->next_out = gunzip_buf; strm->avail_out = sz; rc = zlib_inflateInit2(strm, -MAX_WBITS); if (rc == Z_OK) { rc = zlib_inflate(strm, Z_FINISH); /* after Z_FINISH, only Z_STREAM_END is "we unpacked it all" */ if (rc == Z_STREAM_END) rc = sz - strm->avail_out; else rc = -EINVAL; zlib_inflateEnd(strm); } else rc = -EINVAL; kfree(strm->workspace); gunzip_nomem2: kfree(strm); gunzip_nomem1: return rc; /* returns Z_OK (0) if successful */ }