a938167a22
Signed-off-by: Massimiliano Culpo <massimiliano.culpo@gmail.com> Co-authored-by: Harmen Stoppels <harmenstoppels@gmail.com>
105 lines
3.1 KiB
Python
105 lines
3.1 KiB
Python
"""
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Class to read the symbol table from a Mach-O header
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"""
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from __future__ import with_statement
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import sys
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from _vendoring.macholib.mach_o import (
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MH_CIGAM_64,
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MH_MAGIC_64,
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dylib_module,
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dylib_reference,
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dylib_table_of_contents,
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nlist,
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nlist_64,
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relocation_info,
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)
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__all__ = ["SymbolTable"]
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if sys.version_info[0] == 2:
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range = xrange # noqa: F821
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class SymbolTable(object):
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def __init__(self, macho, header=None, openfile=None):
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if openfile is None:
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openfile = open
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if header is None:
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header = macho.headers[0]
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self.macho_header = header
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with openfile(macho.filename, "rb") as fh:
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self.symtab = header.getSymbolTableCommand()
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self.dysymtab = header.getDynamicSymbolTableCommand()
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if self.symtab is not None:
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self.nlists = self.readSymbolTable(fh)
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if self.dysymtab is not None:
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self.readDynamicSymbolTable(fh)
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def readSymbolTable(self, fh):
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cmd = self.symtab
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fh.seek(self.macho_header.offset + cmd.stroff)
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strtab = fh.read(cmd.strsize)
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fh.seek(self.macho_header.offset + cmd.symoff)
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nlists = []
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if self.macho_header.MH_MAGIC in [MH_MAGIC_64, MH_CIGAM_64]:
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cls = nlist_64
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else:
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cls = nlist
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for _i in range(cmd.nsyms):
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cmd = cls.from_fileobj(fh, _endian_=self.macho_header.endian)
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if cmd.n_un == 0:
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nlists.append((cmd, ""))
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else:
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nlists.append(
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(
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cmd,
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strtab[cmd.n_un : strtab.find(b"\x00", cmd.n_un)], # noqa: E203
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)
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)
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return nlists
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def readDynamicSymbolTable(self, fh):
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cmd = self.dysymtab
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nlists = self.nlists
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self.localsyms = nlists[
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cmd.ilocalsym : cmd.ilocalsym + cmd.nlocalsym # noqa: E203
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]
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self.extdefsyms = nlists[
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cmd.iextdefsym : cmd.iextdefsym + cmd.nextdefsym # noqa: E203
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]
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self.undefsyms = nlists[
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cmd.iundefsym : cmd.iundefsym + cmd.nundefsym # noqa: E203
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]
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if cmd.tocoff == 0:
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self.toc = None
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else:
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self.toc = self.readtoc(fh, cmd.tocoff, cmd.ntoc)
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def readtoc(self, fh, off, n):
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fh.seek(self.macho_header.offset + off)
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return [dylib_table_of_contents.from_fileobj(fh) for i in range(n)]
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def readmodtab(self, fh, off, n):
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fh.seek(self.macho_header.offset + off)
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return [dylib_module.from_fileobj(fh) for i in range(n)]
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def readsym(self, fh, off, n):
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fh.seek(self.macho_header.offset + off)
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refs = []
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for _i in range(n):
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ref = dylib_reference.from_fileobj(fh)
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isym, flags = divmod(ref.isym_flags, 256)
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refs.append((self.nlists[isym], flags))
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return refs
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def readrel(self, fh, off, n):
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fh.seek(self.macho_header.offset + off)
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return [relocation_info.from_fileobj(fh) for i in range(n)]
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