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Extended gzip signature to 3 bytes.

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committer: mfx <mfx> 977403238 +0000
This commit is contained in:
Markus F.X.J. Oberhumer 2000-12-21 12:53:58 +00:00
parent 166d91ac48
commit e787805b81
1 changed files with 11 additions and 4 deletions
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15
src/p_vmlinz.cpp
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@ -126,20 +126,26 @@ int PackVmlinuzI386::uncompressKernel()
// estimate gzip-uncompressed kernel size & alloc buffer // estimate gzip-uncompressed kernel size & alloc buffer
ibuf.alloc((file_size - setup_size) * 3); ibuf.alloc((file_size - setup_size) * 3);
// find gzip/zlib header
for (int gzoff = setup_size; gzoff < file_size; gzoff++) for (int gzoff = setup_size; gzoff < file_size; gzoff++)
{ {
int off = find(obuf + gzoff, file_size - gzoff, "\x1F\x8B", 2); // find gzip header (2 bytes magic, 1 byte method "deflated")
int off = find(obuf + gzoff, file_size - gzoff, "\x1F\x8B\x08", 3);
if (off < 0) if (off < 0)
break; break;
gzoff += off; gzoff += off;
// try to decompress
fi->seek(gzoff, SEEK_SET); fi->seek(gzoff, SEEK_SET);
gzFile zf = gzdopen(fi->getFd(), "r"); gzFile zf = gzdopen(fi->getFd(), "r");
if (zf == 0) if (zf == 0)
break; break;
int klen = gzread(zf, ibuf, ibuf.getSize()); int klen = gzread(zf, ibuf, ibuf.getSize());
if (klen >= file_size) if (klen <= file_size)
return klen; continue;
// FIXME: check for special magic bytes in ibuf ???
// FIXME: check for kernel architecture ???
// FIXME: check for special klen size, e.g. (klen & 0xfff) == 0 ???
return klen;
} }
return 0; return 0;
@ -159,6 +165,7 @@ void PackVmlinuzI386::readKernel()
// copy the setup boot code // copy the setup boot code
setup_buf.alloc(setup_size); setup_buf.alloc(setup_size);
memcpy(setup_buf, obuf, setup_size); memcpy(setup_buf, obuf, setup_size);
//OutputFile::dump("setup.img", setup_buf, setup_size);
obuf.free(); obuf.free();
obuf.allocForCompression(klen); obuf.allocForCompression(klen);