79 lines
1.6 KiB
Python
79 lines
1.6 KiB
Python
import uio
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def write_fqdn(buf, name):
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parts = name.split(".")
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for p in parts:
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buf.writebin("B", len(p))
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buf.write(p)
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buf.writebin("B", 0)
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def skip_fqdn(buf):
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while True:
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sz = buf.readbin("B")
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if not sz:
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break
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if sz >= 0xc0:
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buf.readbin("B")
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break
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buf.read(sz)
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def make_req(buf, fqdn, is_ipv6):
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typ = 1 # A
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if is_ipv6:
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typ = 28 # AAAA
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buf.writebin(">H", 0)
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buf.writebin(">H", 0x100)
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# q count
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buf.writebin(">H", 1)
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buf.writebin(">H", 0)
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# squashed together
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buf.writebin(">I", 0)
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write_fqdn(buf, fqdn)
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buf.writebin(">H", typ)
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buf.writebin(">H", 1) # Class
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def parse_resp(buf, is_ipv6):
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typ = 1 # A
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if is_ipv6:
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typ = 28 # AAAA
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id = buf.readbin(">H")
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flags = buf.readbin(">H")
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assert flags & 0x8000
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qcnt = buf.readbin(">H")
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acnt = buf.readbin(">H")
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nscnt = buf.readbin(">H")
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addcnt = buf.readbin(">H")
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#print(qcnt, acnt, nscnt, addcnt)
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skip_fqdn(buf)
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v = buf.readbin(">H")
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#print(v)
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v = buf.readbin(">H")
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#print(v)
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for i in range(acnt):
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#print("Resp #%d" % i)
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#v = read_fqdn(buf)
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#print(v)
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skip_fqdn(buf)
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t = buf.readbin(">H")
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#print("Type", t)
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v = buf.readbin(">H")
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#print("Class", v)
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v = buf.readbin(">I")
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#print("TTL", v)
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rlen = buf.readbin(">H")
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#print("rlen", rlen)
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rval = buf.read(rlen)
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#print(rval)
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if t == typ:
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return rval
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