dns.py 文件源码

def i2m(self, pkt, s):
        if pkt.type == 1: # A
            if s:
                s = inet_aton(s)
        elif pkt.type in [2,3,4,5]: # NS, MD, MF, CNAME
            s = "".join(map(lambda x: chr(len(x))+x, s.split(".")))
            if ord(s[-1]):
                s += "\x00"
        elif pkt.type == 16: # TXT
            if s:
                ret_s = ""
                # The initial string must be splitted into a list of strings
                # prepended with theirs sizes.
                while len(s) >= 255:
                    ret_s += "\xff" + s[:255]
                    s = s[255:]
                # The remaining string is less than 255 bytes long    
                if len(s):
                    ret_s += struct.pack("!B", len(s)) + s
                s = ret_s
        elif pkt.type == 28: # AAAA
            if s:
                s = inet_pton(socket.AF_INET6, s)
        return s