103 lines
3.3 KiB
Python
103 lines
3.3 KiB
Python
#!/usr/bin/python
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# Copyright (c) 2014 SUSE Linux Products GmbH
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#
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be included in
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# all copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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# SOFTWARE.
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import struct
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class Cpio(object):
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def __init__(self, buf):
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self.buf = buf
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self.off = 0
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def __iter__(self):
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return self
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def next(self):
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f = CpioFile(self.off, self.buf)
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if f.fin():
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raise StopIteration
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self.off = self.off+f.length()
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return f
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class CpioFile(object):
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def __init__(self, off, buf):
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self.off = off
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self.buf = buf
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if off&3:
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raise Exception("invalid offset %d"% off)
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fmt = "6s8s8s8s8s8s8s8s8s8s8s8s8s8s"
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off = self.off + struct.calcsize(fmt)
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fields = struct.unpack(fmt, buf[self.off:off])
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if fields[0] != "070701":
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raise Exception("invalid cpio header %s"%self.c_magic)
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names = ("c_ino", "c_mode", "c_uid", "c_gid",
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"c_nlink", "c_mtime", "c_filesize",
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"c_devmajor", "c_devminor", "c_rdevmajor",
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"c_rdevminor", "c_namesize", "c_check")
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for (n, v) in zip(names, fields[1:]):
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setattr(self, n, int(v, 16))
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nlen = self.c_namesize - 1
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self.name = struct.unpack('%ds'%nlen, buf[off:off+nlen])[0]
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off = off + nlen + 1
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if off&3:
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off = off + 4-(off&3) # padding
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self.payloadstart = off
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def fin(self):
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return self.name == 'TRAILER!!!'
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def __str__(self):
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return "[%s %d]"%(self.name, self.c_filesize)
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def header(self):
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return self.buf[self.payloadstart:self.payloadstart+self.c_filesize]
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def length(self):
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l = self.payloadstart-self.off + self.c_filesize
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if self.c_filesize&3:
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l = l + 4-(self.c_filesize&3)
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return l
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if __name__ == '__main__':
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from optparse import OptionParser
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parser = OptionParser()
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parser.add_option("--debug", action="store_true", help="debug output")
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parser.add_option("--verbose", action="store_true", help="verbose")
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(options, args) = parser.parse_args()
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for fn in args:
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fh = open(fn, 'rb')
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cpio = Cpio(fh.read())
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for i in cpio:
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print i
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ofh = open(i.name, 'wb')
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ofh.write(i.header())
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ofh.close()
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# vim: sw=4 et
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