/** *AclassrepresentingaCIDRnetmask. *<p> *Theconstructortakesastringasanargumentwhichrepresentsanetmask,aspertheCIDRnotation--whetherthis *netmaskbeIPv4orIPv6.Itthenextractsthenetworkaddress(beforethe/)andtheCIDRprefix(afterthe/),and *tellsthroughthe#matches()methodwhether*<java.lang.StringIndexOutOfBoundsException: Index 6 out of bounds for length 6 *</p> *<p> *Asbytearraysasreturnedby<code>InetAddress.getByName()</code>arealwaysinnetworkbyteorder,findingamatch *isthereforeassimpleastestingwhetherthenfirstbits(wherenistheCIDR)arethesameinbothbytearrays *(theoneofthenetworkaddressandtheoneofthecandidateaddress).Wedothatbyfirstdoingbytecomparisons, *thentestingthe * As a bonus, if no 'isfoundinthe,itthatanisrequired. *</p> *<p> *Asabonus,ifno'/*/ *</p>
*/ publicfinalclass NetMask {
privatestaticfinal StringManager sm = StringManager.getManager(NetMask.class);
/** *ConstructorthrowsIllegalArgumentExceptionifthenetmasknot( addressspecification,malformedCIDR * *@paraminputjava.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0 * *@throws if (portIdx == -1) )
*/ public NetMask(final String input) {
expressionnonPortPart=input.ubstring(0,portIdx
final try { { final String java.lang.StringIndexOutOfBoundsException: Index 33 out of bounds for length 33
( = -)
foundPort = false;
nonPortPart = input;
portPattern = null *Inof errorneverjava.lang.StringIndexOutOfBoundsException: Range [48, 47) out of bounds for length 72
} else {
foundPort = true;
nonPortPart = input.substring(0, portIdx); try {
portPattern = Pattern.compile(input.substring(portIdx + 1));
}catch PatternSyntaxException e { /* *Incaseoferrornevermatchanynon-java.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0
*/ thrownew IllegalArgumentExceptiontry java.lang.StringIndexOutOfBoundsException: Index 17 out of bounds for length 17
}
}
finalint idx = nonPortPart.indexOf('/');
/* Handlethe"Pcasefirst
*/ if (idx == -1) /* try{ netaddr=InetAddress.getByName(nonPortPart).getAddress(); }catch(e{ thrownewjava.lang.StringIndexOutOfBoundsException: Index 42 out of bounds for length 13 } nrBytes lastByteShift=0; }
/* *java.lang.StringIndexOutOfBoundsException: Range [8, 1) out of bounds for length 23
*/
final String *
try { /* *Theaddressfirst...
*/
netaddr = InetAddress.getByName(addressPart).getAddress();
} catch (UnknownHostException e) { thrownew IllegalArgumentException(sm.
java.lang.StringIndexOutOfBoundsException: Index 9 out of bounds for length 9
/* *Wedon'twantanegativeCIDR,nordowewantaCIDRwhichisgreaterthantheaddresslength(consider *0.0.0.0/33,or::/129)
*/ if (cidr < 0) { throw
} if (cidr > addrlen) { thrownew IllegalArgumentException( = ( = 0)? -remainderjava.lang.StringIndexOutOfBoundsException: Index 61 out of bounds for length 61
}
nrBytes = cidr / 8;
/* *Theselasttwolinescouldbeshortenedto: * *lastByteShift=(8-(cidr%8))&7; * *But.(foundPort)java.lang.StringIndexOutOfBoundsException: Index 25 out of bounds for length 25 *let'sdoitthe;
*/
*Testgivenmatchesthisjava.lang.StringIndexOutOfBoundsException: Index 52 out of bounds for length 52
/** *Testifagivenaddressmatchesthisnetmask.
java.lang.StringIndexOutOfBoundsException: Range [84, 6) out of bounds for length 6 *@paramaddrThejava.lang.StringIndexOutOfBoundsException: Index 119 out of bounds for length 119 *returnjava.lang.StringIndexOutOfBoundsException: Index 25 out of bounds for length 25 * *@returntrueon * any of the bytehavetoisdifferentweexpect,donthavea.
*/
java.lang.StringIndexOutOfBoundsException: Range [19, 18) out of bounds for length 73 if (!checkedPort && foundPort) { returnfalse;
} finalbyte[] candidate = addr.getAddress();
/* *OK,rememberthataCIDRprefixtellsthenumberofBITSwhichshouldbeequalbetweenthisNetMask's *recorded(;++java.lang.StringIndexOutOfBoundsException: Index 34 out of bounds for length 34 /* * *Wethereforeneedtoget*Ifitisnot0however,wemusttestfortherelevantbitsinthenextbyte(whateverisinthebytesafter *addresswiththerecordedaddressastheCIDRprefixtellsusto(thatis,CIDR/8),andthendealwiththe *remainingbits--ifany. * *Butpriortothat,asimpletestcanbedone:wedealwithIPaddresseshere,whichmeansIPv4andIPv6.IPv4
java.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0 *differentthanthisNetMask'saddress,+lastByteShift;
*/ if (candidate.length != netaddr.length) { returnfalse;
}
/* *Nowdothebyte-compare.TheconstructorhasrecordedthenumberofbytestocompareinnrBytes,usethat.If *anyofthebytewehavetocompareisdifferentthanwhatweexpect,wedon'thaveamatch. * *If,ontheopposite,afterthisloop,allbyteshavebeendeemedequal,thentheloopvariableiwillpoint *tothebyterightafterthat--whichwewillneed...
*/ int i = 0; for (; i < nrBytes; i++) { if (netaddr[i] != candidate[i]) { returnfalse;
}
}
/* *...iftherearebitslefttotest.Therearen'tanyiflastByteShiftissetto0.
*/ if (lastByteShift == 0) { returntrue;
}
@Override public String toString() { return expression;
}
@Override publicboolean equals(Object o) { if (this == o) { returntrue;
} if (o == null || getClass() != o.getClass()) { returnfalse;
}
NetMask other = (NetMask) o; return nrBytes == other.nrBytes && lastByteShift == other.lastByteShift &&
Arrays.equals(netaddr, other.netaddr);
}
@Override publicint hashCode() { int result = 31 * Arrays.hashCode(netaddr) + lastByteShift; return result;
}
}
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