From 7dcaf1830e9e8c30606316bd8b98b4e1ae0cc6d0 Mon Sep 17 00:00:00 2001
From: "James M. Greene" <james.m.greene@gmail.com>
Date: Sat, 19 Aug 2017 16:11:41 -0500
Subject: [PATCH] Allow `ipaddr.IPv4.subnetMaskFromPrefixLength(32)`

Fixes #73
Fixes #64
---
 README.md               |  4 +--
 ipaddr.min.js           |  2 +-
 lib/ipaddr.js           | 38 +++++++++++---------
 src/ipaddr.coffee       | 31 ++++++++++-------
 test/ipaddr.test.coffee | 77 +++++++++++++++++++++--------------------
 5 files changed, 82 insertions(+), 70 deletions(-)

diff --git a/README.md b/README.md
index 938790e..6876a3b 100644
--- a/README.md
+++ b/README.md
@@ -183,8 +183,8 @@ ipaddr.IPv4.parse('255.192.164.0').prefixLengthFromSubnetMask()  == null
 `subnetMaskFromPrefixLength()` will return an IPv4 netmask for a valid CIDR prefix length.
 
 ```js
-ipaddr.IPv4.subnetMaskFromPrefixLength("24") == "255.255.255.0"
-ipaddr.IPv4.subnetMaskFromPrefixLength("29") == "255.255.255.248"
+ipaddr.IPv4.subnetMaskFromPrefixLength(24) == "255.255.255.0"
+ipaddr.IPv4.subnetMaskFromPrefixLength(29) == "255.255.255.248"
 ```
 
 `broadcastAddressFromCIDR()` will return the broadcast address for a given IPv4 interface and netmask in CIDR notation.
diff --git a/ipaddr.min.js b/ipaddr.min.js
index 4967da1..4931324 100644
--- a/ipaddr.min.js
+++ b/ipaddr.min.js
@@ -1 +1 @@
-(function(){var r,t,n,e,i,o,a,s,p;t={},s=this,"undefined"!=typeof module&&null!==module&&module.exports?module.exports=t:s.ipaddr=t,a=function(r,t,n,e){var i,o;if(r.length!==t.length)throw new Error("ipaddr: cannot match CIDR for objects with different lengths");for(i=0;e>0;){if((o=n-e)<0&&(o=0),r[i]>>o!=t[i]>>o)return!1;e-=n,i+=1}return!0},t.subnetMatch=function(r,t,n){var e,i,o,a,s;null==n&&(n="unicast");for(o in t)for(!(a=t[o])[0]||a[0]instanceof Array||(a=[a]),e=0,i=a.length;e<i;e++)if(s=a[e],r.kind()===s[0].kind()&&r.match.apply(r,s))return o;return n},t.IPv4=function(){function r(r){var t,n,e;if(4!==r.length)throw new Error("ipaddr: ipv4 octet count should be 4");for(t=0,n=r.length;t<n;t++)if(!(0<=(e=r[t])&&e<=255))throw new Error("ipaddr: ipv4 octet should fit in 8 bits");this.octets=r}return r.prototype.kind=function(){return"ipv4"},r.prototype.toString=function(){return this.octets.join(".")},r.prototype.toNormalizedString=function(){return this.toString()},r.prototype.toByteArray=function(){return this.octets.slice(0)},r.prototype.match=function(r,t){var n;if(void 0===t&&(r=(n=r)[0],t=n[1]),"ipv4"!==r.kind())throw new Error("ipaddr: cannot match ipv4 address with non-ipv4 one");return a(this.octets,r.octets,8,t)},r.prototype.SpecialRanges={unspecified:[[new r([0,0,0,0]),8]],broadcast:[[new r([255,255,255,255]),32]],multicast:[[new r([224,0,0,0]),4]],linkLocal:[[new r([169,254,0,0]),16]],loopback:[[new r([127,0,0,0]),8]],carrierGradeNat:[[new r([100,64,0,0]),10]],private:[[new r([10,0,0,0]),8],[new r([172,16,0,0]),12],[new r([192,168,0,0]),16]],reserved:[[new r([192,0,0,0]),24],[new r([192,0,2,0]),24],[new r([192,88,99,0]),24],[new r([198,51,100,0]),24],[new r([203,0,113,0]),24],[new r([240,0,0,0]),4]]},r.prototype.range=function(){return t.subnetMatch(this,this.SpecialRanges)},r.prototype.toIPv4MappedAddress=function(){return t.IPv6.parse("::ffff:"+this.toString())},r.prototype.prefixLengthFromSubnetMask=function(){var r,t,n,e,i,o,a;for(a={0:8,128:7,192:6,224:5,240:4,248:3,252:2,254:1,255:0},r=0,i=!1,t=n=3;n>=0;t=n+=-1){if(!((e=this.octets[t])in a))return null;if(o=a[e],i&&0!==o)return null;8!==o&&(i=!0),r+=o}return 32-r},r}(),n="(0?\\d+|0x[a-f0-9]+)",e={fourOctet:new RegExp("^"+n+"\\."+n+"\\."+n+"\\."+n+"$","i"),longValue:new RegExp("^"+n+"$","i")},t.IPv4.parser=function(r){var t,n,i,o,a;if(n=function(r){return"0"===r[0]&&"x"!==r[1]?parseInt(r,8):parseInt(r)},t=r.match(e.fourOctet))return function(){var r,e,o,a;for(a=[],r=0,e=(o=t.slice(1,6)).length;r<e;r++)i=o[r],a.push(n(i));return a}();if(t=r.match(e.longValue)){if((a=n(t[1]))>4294967295||a<0)throw new Error("ipaddr: address outside defined range");return function(){var r,t;for(t=[],o=r=0;r<=24;o=r+=8)t.push(a>>o&255);return t}().reverse()}return null},t.IPv6=function(){function r(r,t){var n,e,i,o,a,s;if(16===r.length)for(this.parts=[],n=e=0;e<=14;n=e+=2)this.parts.push(r[n]<<8|r[n+1]);else{if(8!==r.length)throw new Error("ipaddr: ipv6 part count should be 8 or 16");this.parts=r}for(i=0,o=(s=this.parts).length;i<o;i++)if(!(0<=(a=s[i])&&a<=65535))throw new Error("ipaddr: ipv6 part should fit in 16 bits");t&&(this.zoneId=t)}return r.prototype.kind=function(){return"ipv6"},r.prototype.toString=function(){var r,t,n,e,i,o,a,s,p;for(s=function(){var r,t,n,e;for(e=[],r=0,t=(n=this.parts).length;r<t;r++)i=n[r],e.push(i.toString(16));return e}.call(this),t=[],o=function(r){return t.push(r)},a=0,n=0,e=s.length;n<e;n++)switch(i=s[n],a){case 0:o("0"===i?"":i),a=1;break;case 1:"0"===i?a=2:o(i);break;case 2:"0"!==i&&(o(""),o(i),a=3);break;case 3:o(i)}return 2===a&&(o(""),o("")),r=t.join(":"),p="",this.zoneId&&(p="%"+this.zoneId),r+p},r.prototype.toByteArray=function(){var r,t,n,e,i;for(r=[],t=0,n=(i=this.parts).length;t<n;t++)e=i[t],r.push(e>>8),r.push(255&e);return r},r.prototype.toNormalizedString=function(){var r,t,n;return r=function(){var r,n,e,i;for(i=[],r=0,n=(e=this.parts).length;r<n;r++)t=e[r],i.push(t.toString(16));return i}.call(this).join(":"),n="",this.zoneId&&(n="%"+this.zoneId),r+n},r.prototype.match=function(r,t){var n;if(void 0===t&&(r=(n=r)[0],t=n[1]),"ipv6"!==r.kind())throw new Error("ipaddr: cannot match ipv6 address with non-ipv6 one");return a(this.parts,r.parts,16,t)},r.prototype.SpecialRanges={unspecified:[new r([0,0,0,0,0,0,0,0]),128],linkLocal:[new r([65152,0,0,0,0,0,0,0]),10],multicast:[new r([65280,0,0,0,0,0,0,0]),8],loopback:[new r([0,0,0,0,0,0,0,1]),128],uniqueLocal:[new r([64512,0,0,0,0,0,0,0]),7],ipv4Mapped:[new r([0,0,0,0,0,65535,0,0]),96],rfc6145:[new r([0,0,0,0,65535,0,0,0]),96],rfc6052:[new r([100,65435,0,0,0,0,0,0]),96],"6to4":[new r([8194,0,0,0,0,0,0,0]),16],teredo:[new r([8193,0,0,0,0,0,0,0]),32],reserved:[[new r([8193,3512,0,0,0,0,0,0]),32]]},r.prototype.range=function(){return t.subnetMatch(this,this.SpecialRanges)},r.prototype.isIPv4MappedAddress=function(){return"ipv4Mapped"===this.range()},r.prototype.toIPv4Address=function(){var r,n,e;if(!this.isIPv4MappedAddress())throw new Error("ipaddr: trying to convert a generic ipv6 address to ipv4");return e=this.parts.slice(-2),r=e[0],n=e[1],new t.IPv4([r>>8,255&r,n>>8,255&n])},r.prototype.prefixLengthFromSubnetMask=function(){var r,t,n,e,i,o,a;for(a={0:16,32768:15,49152:14,57344:13,61440:12,63488:11,64512:10,65024:9,65280:8,65408:7,65472:6,65504:5,65520:4,65528:3,65532:2,65534:1,65535:0},r=0,i=!1,t=n=7;n>=0;t=n+=-1){if(!((e=this.parts[t])in a))return null;if(o=a[e],i&&0!==o)return null;16!==o&&(i=!0),r+=o}return 128-r},r}(),i="(?:[0-9a-f]+::?)+",p="%[0-9a-z]{1,}",o={zoneIndex:new RegExp(p,"i"),native:new RegExp("^(::)?("+i+")?([0-9a-f]+)?(::)?("+p+")?$","i"),transitional:new RegExp("^((?:"+i+")|(?:::)(?:"+i+")?)"+n+"\\."+n+"\\."+n+"\\."+n+"(%[0-9a-z]{1,})?$","i")},r=function(r,t){var n,e,i,o,a,s;if(r.indexOf("::")!==r.lastIndexOf("::"))return null;for((s=(r.match(p)||[])[0])&&(s=s.substring(1),r=r.replace(/%.+$/,"")),n=0,e=-1;(e=r.indexOf(":",e+1))>=0;)n++;if("::"===r.substr(0,2)&&n--,"::"===r.substr(-2,2)&&n--,n>t)return null;for(a=t-n,o=":";a--;)o+="0:";return":"===(r=r.replace("::",o))[0]&&(r=r.slice(1)),":"===r[r.length-1]&&(r=r.slice(0,-1)),t=function(){var t,n,e,o;for(o=[],t=0,n=(e=r.split(":")).length;t<n;t++)i=e[t],o.push(parseInt(i,16));return o}(),{parts:t,zoneId:s}},t.IPv6.parser=function(t){var n,e,i,a,s,p;if(o.native.test(t))return r(t,8);if((a=t.match(o.transitional))&&(n=r(a[1].slice(0,-1),6)).parts){for(e=0,i=(p=[parseInt(a[2]),parseInt(a[3]),parseInt(a[4]),parseInt(a[5])]).length;e<i;e++)if(!(0<=(s=p[e])&&s<=255))return null;return n.parts.push(p[0]<<8|p[1]),n.parts.push(p[2]<<8|p[3]),{parts:n.parts,zoneId:n.zoneId}}return null},t.IPv4.isIPv4=t.IPv6.isIPv6=function(r){return null!==this.parser(r)},t.IPv4.isValid=function(r){try{return new this(this.parser(r)),!0}catch(r){return r,!1}},t.IPv4.isValidFourPartDecimal=function(r){return!(!t.IPv4.isValid(r)||!r.match(/^\d+(\.\d+){3}$/))},t.IPv6.isValid=function(r){var t;if("string"==typeof r&&-1===r.indexOf(":"))return!1;try{return t=this.parser(r),new this(t.parts,t.zoneId),!0}catch(r){return r,!1}},t.IPv4.parse=function(r){var t;if(null===(t=this.parser(r)))throw new Error("ipaddr: string is not formatted like ip address");return new this(t)},t.IPv6.parse=function(r){var t;if(null===(t=this.parser(r)).parts)throw new Error("ipaddr: string is not formatted like ip address");return new this(t.parts,t.zoneId)},t.IPv4.parseCIDR=function(r){var t,n;if((n=r.match(/^(.+)\/(\d+)$/))&&(t=parseInt(n[2]))>=0&&t<=32)return[this.parse(n[1]),t];throw new Error("ipaddr: string is not formatted like an IPv4 CIDR range")},t.IPv4.subnetMaskFromPrefixLength=function(r){var n,e;if(r<0||r>32)throw new Error("ipaddr: invalid prefix length");for(e=Array(4).fill(0),n=0;n<Math.floor(r/8);)e[n]=255,n++;return e[Math.floor(r/8)]=Math.pow(2,r%8)-1<<8-r%8,new t.IPv4(e)},t.IPv4.broadcastAddressFromCIDR=function(r){var n,e,i,o;try{for(e=t.IPv4.parseCIDR(r)[0],o=this.subnetMaskFromPrefixLength([t.IPv4.parseCIDR(r)[1]]),i=[],n=0;n<4;)i.push(parseInt(e.octets[n],10)|255^parseInt(o.octets[n],10)),n++;return new t.IPv4(i)}catch(r){throw r,new Error("ipaddr: the address does not have IPv4 CIDR format")}},t.IPv4.networkAddressFromCIDR=function(r){var n,e,i,o;try{for(e=t.IPv4.parseCIDR(r)[0],o=this.subnetMaskFromPrefixLength([t.IPv4.parseCIDR(r)[1]]),i=[],n=0;n<4;)i.push(parseInt(e.octets[n],10)&parseInt(o.octets[n],10)),n++;return new t.IPv4(i)}catch(r){throw r,new Error("ipaddr: the address does not have IPv4 CIDR format")}},t.IPv6.parseCIDR=function(r){var t,n;if((n=r.match(/^(.+)\/(\d+)$/))&&(t=parseInt(n[2]))>=0&&t<=128)return[this.parse(n[1]),t];throw new Error("ipaddr: string is not formatted like an IPv6 CIDR range")},t.isValid=function(r){return t.IPv6.isValid(r)||t.IPv4.isValid(r)},t.parse=function(r){if(t.IPv6.isValid(r))return t.IPv6.parse(r);if(t.IPv4.isValid(r))return t.IPv4.parse(r);throw new Error("ipaddr: the address has neither IPv6 nor IPv4 format")},t.parseCIDR=function(r){try{return t.IPv6.parseCIDR(r)}catch(n){n;try{return t.IPv4.parseCIDR(r)}catch(r){throw r,new Error("ipaddr: the address has neither IPv6 nor IPv4 CIDR format")}}},t.fromByteArray=function(r){var n;if(4===(n=r.length))return new t.IPv4(r);if(16===n)return new t.IPv6(r);throw new Error("ipaddr: the binary input is neither an IPv6 nor IPv4 address")},t.process=function(r){var t;return"ipv6"===(t=this.parse(r)).kind()&&t.isIPv4MappedAddress()?t.toIPv4Address():t}}).call(this);
\ No newline at end of file
+(function(){var r,t,n,e,i,o,a,s,p;t={},s=this,"undefined"!=typeof module&&null!==module&&module.exports?module.exports=t:s.ipaddr=t,a=function(r,t,n,e){var i,o;if(r.length!==t.length)throw new Error("ipaddr: cannot match CIDR for objects with different lengths");for(i=0;e>0;){if((o=n-e)<0&&(o=0),r[i]>>o!=t[i]>>o)return!1;e-=n,i+=1}return!0},t.subnetMatch=function(r,t,n){var e,i,o,a,s;null==n&&(n="unicast");for(o in t)for(!(a=t[o])[0]||a[0]instanceof Array||(a=[a]),e=0,i=a.length;e<i;e++)if(s=a[e],r.kind()===s[0].kind()&&r.match.apply(r,s))return o;return n},t.IPv4=function(){function r(r){var t,n,e;if(4!==r.length)throw new Error("ipaddr: ipv4 octet count should be 4");for(t=0,n=r.length;t<n;t++)if(!(0<=(e=r[t])&&e<=255))throw new Error("ipaddr: ipv4 octet should fit in 8 bits");this.octets=r}return r.prototype.kind=function(){return"ipv4"},r.prototype.toString=function(){return this.octets.join(".")},r.prototype.toNormalizedString=function(){return this.toString()},r.prototype.toByteArray=function(){return this.octets.slice(0)},r.prototype.match=function(r,t){var n;if(void 0===t&&(r=(n=r)[0],t=n[1]),"ipv4"!==r.kind())throw new Error("ipaddr: cannot match ipv4 address with non-ipv4 one");return a(this.octets,r.octets,8,t)},r.prototype.SpecialRanges={unspecified:[[new r([0,0,0,0]),8]],broadcast:[[new r([255,255,255,255]),32]],multicast:[[new r([224,0,0,0]),4]],linkLocal:[[new r([169,254,0,0]),16]],loopback:[[new r([127,0,0,0]),8]],carrierGradeNat:[[new r([100,64,0,0]),10]],private:[[new r([10,0,0,0]),8],[new r([172,16,0,0]),12],[new r([192,168,0,0]),16]],reserved:[[new r([192,0,0,0]),24],[new r([192,0,2,0]),24],[new r([192,88,99,0]),24],[new r([198,51,100,0]),24],[new r([203,0,113,0]),24],[new r([240,0,0,0]),4]]},r.prototype.range=function(){return t.subnetMatch(this,this.SpecialRanges)},r.prototype.toIPv4MappedAddress=function(){return t.IPv6.parse("::ffff:"+this.toString())},r.prototype.prefixLengthFromSubnetMask=function(){var r,t,n,e,i,o,a;for(a={0:8,128:7,192:6,224:5,240:4,248:3,252:2,254:1,255:0},r=0,i=!1,t=n=3;n>=0;t=n+=-1){if(!((e=this.octets[t])in a))return null;if(o=a[e],i&&0!==o)return null;8!==o&&(i=!0),r+=o}return 32-r},r}(),n="(0?\\d+|0x[a-f0-9]+)",e={fourOctet:new RegExp("^"+n+"\\."+n+"\\."+n+"\\."+n+"$","i"),longValue:new RegExp("^"+n+"$","i")},t.IPv4.parser=function(r){var t,n,i,o,a;if(n=function(r){return"0"===r[0]&&"x"!==r[1]?parseInt(r,8):parseInt(r)},t=r.match(e.fourOctet))return function(){var r,e,o,a;for(a=[],r=0,e=(o=t.slice(1,6)).length;r<e;r++)i=o[r],a.push(n(i));return a}();if(t=r.match(e.longValue)){if((a=n(t[1]))>4294967295||a<0)throw new Error("ipaddr: address outside defined range");return function(){var r,t;for(t=[],o=r=0;r<=24;o=r+=8)t.push(a>>o&255);return t}().reverse()}return null},t.IPv6=function(){function r(r,t){var n,e,i,o,a,s;if(16===r.length)for(this.parts=[],n=e=0;e<=14;n=e+=2)this.parts.push(r[n]<<8|r[n+1]);else{if(8!==r.length)throw new Error("ipaddr: ipv6 part count should be 8 or 16");this.parts=r}for(i=0,o=(s=this.parts).length;i<o;i++)if(!(0<=(a=s[i])&&a<=65535))throw new Error("ipaddr: ipv6 part should fit in 16 bits");t&&(this.zoneId=t)}return r.prototype.kind=function(){return"ipv6"},r.prototype.toString=function(){var r,t,n,e,i,o,a,s,p;for(s=function(){var r,t,n,e;for(e=[],r=0,t=(n=this.parts).length;r<t;r++)i=n[r],e.push(i.toString(16));return e}.call(this),t=[],o=function(r){return t.push(r)},a=0,n=0,e=s.length;n<e;n++)switch(i=s[n],a){case 0:o("0"===i?"":i),a=1;break;case 1:"0"===i?a=2:o(i);break;case 2:"0"!==i&&(o(""),o(i),a=3);break;case 3:o(i)}return 2===a&&(o(""),o("")),r=t.join(":"),p="",this.zoneId&&(p="%"+this.zoneId),r+p},r.prototype.toByteArray=function(){var r,t,n,e,i;for(r=[],t=0,n=(i=this.parts).length;t<n;t++)e=i[t],r.push(e>>8),r.push(255&e);return r},r.prototype.toNormalizedString=function(){var r,t,n;return r=function(){var r,n,e,i;for(i=[],r=0,n=(e=this.parts).length;r<n;r++)t=e[r],i.push(t.toString(16));return i}.call(this).join(":"),n="",this.zoneId&&(n="%"+this.zoneId),r+n},r.prototype.match=function(r,t){var n;if(void 0===t&&(r=(n=r)[0],t=n[1]),"ipv6"!==r.kind())throw new Error("ipaddr: cannot match ipv6 address with non-ipv6 one");return a(this.parts,r.parts,16,t)},r.prototype.SpecialRanges={unspecified:[new r([0,0,0,0,0,0,0,0]),128],linkLocal:[new r([65152,0,0,0,0,0,0,0]),10],multicast:[new r([65280,0,0,0,0,0,0,0]),8],loopback:[new r([0,0,0,0,0,0,0,1]),128],uniqueLocal:[new r([64512,0,0,0,0,0,0,0]),7],ipv4Mapped:[new r([0,0,0,0,0,65535,0,0]),96],rfc6145:[new r([0,0,0,0,65535,0,0,0]),96],rfc6052:[new r([100,65435,0,0,0,0,0,0]),96],"6to4":[new r([8194,0,0,0,0,0,0,0]),16],teredo:[new r([8193,0,0,0,0,0,0,0]),32],reserved:[[new r([8193,3512,0,0,0,0,0,0]),32]]},r.prototype.range=function(){return t.subnetMatch(this,this.SpecialRanges)},r.prototype.isIPv4MappedAddress=function(){return"ipv4Mapped"===this.range()},r.prototype.toIPv4Address=function(){var r,n,e;if(!this.isIPv4MappedAddress())throw new Error("ipaddr: trying to convert a generic ipv6 address to ipv4");return e=this.parts.slice(-2),r=e[0],n=e[1],new t.IPv4([r>>8,255&r,n>>8,255&n])},r.prototype.prefixLengthFromSubnetMask=function(){var r,t,n,e,i,o,a;for(a={0:16,32768:15,49152:14,57344:13,61440:12,63488:11,64512:10,65024:9,65280:8,65408:7,65472:6,65504:5,65520:4,65528:3,65532:2,65534:1,65535:0},r=0,i=!1,t=n=7;n>=0;t=n+=-1){if(!((e=this.parts[t])in a))return null;if(o=a[e],i&&0!==o)return null;16!==o&&(i=!0),r+=o}return 128-r},r}(),i="(?:[0-9a-f]+::?)+",p="%[0-9a-z]{1,}",o={zoneIndex:new RegExp(p,"i"),native:new RegExp("^(::)?("+i+")?([0-9a-f]+)?(::)?("+p+")?$","i"),transitional:new RegExp("^((?:"+i+")|(?:::)(?:"+i+")?)"+n+"\\."+n+"\\."+n+"\\."+n+"(%[0-9a-z]{1,})?$","i")},r=function(r,t){var n,e,i,o,a,s;if(r.indexOf("::")!==r.lastIndexOf("::"))return null;for((s=(r.match(p)||[])[0])&&(s=s.substring(1),r=r.replace(/%.+$/,"")),n=0,e=-1;(e=r.indexOf(":",e+1))>=0;)n++;if("::"===r.substr(0,2)&&n--,"::"===r.substr(-2,2)&&n--,n>t)return null;for(a=t-n,o=":";a--;)o+="0:";return":"===(r=r.replace("::",o))[0]&&(r=r.slice(1)),":"===r[r.length-1]&&(r=r.slice(0,-1)),t=function(){var t,n,e,o;for(o=[],t=0,n=(e=r.split(":")).length;t<n;t++)i=e[t],o.push(parseInt(i,16));return o}(),{parts:t,zoneId:s}},t.IPv6.parser=function(t){var n,e,i,a,s,p;if(o.native.test(t))return r(t,8);if((a=t.match(o.transitional))&&(n=r(a[1].slice(0,-1),6)).parts){for(e=0,i=(p=[parseInt(a[2]),parseInt(a[3]),parseInt(a[4]),parseInt(a[5])]).length;e<i;e++)if(!(0<=(s=p[e])&&s<=255))return null;return n.parts.push(p[0]<<8|p[1]),n.parts.push(p[2]<<8|p[3]),{parts:n.parts,zoneId:n.zoneId}}return null},t.IPv4.isIPv4=t.IPv6.isIPv6=function(r){return null!==this.parser(r)},t.IPv4.isValid=function(r){try{return new this(this.parser(r)),!0}catch(r){return r,!1}},t.IPv4.isValidFourPartDecimal=function(r){return!(!t.IPv4.isValid(r)||!r.match(/^\d+(\.\d+){3}$/))},t.IPv6.isValid=function(r){var t;if("string"==typeof r&&-1===r.indexOf(":"))return!1;try{return t=this.parser(r),new this(t.parts,t.zoneId),!0}catch(r){return r,!1}},t.IPv4.parse=function(r){var t;if(null===(t=this.parser(r)))throw new Error("ipaddr: string is not formatted like ip address");return new this(t)},t.IPv6.parse=function(r){var t;if(null===(t=this.parser(r)).parts)throw new Error("ipaddr: string is not formatted like ip address");return new this(t.parts,t.zoneId)},t.IPv4.parseCIDR=function(r){var t,n;if((n=r.match(/^(.+)\/(\d+)$/))&&(t=parseInt(n[2]))>=0&&t<=32)return[this.parse(n[1]),t];throw new Error("ipaddr: string is not formatted like an IPv4 CIDR range")},t.IPv4.subnetMaskFromPrefixLength=function(r){var t,n,e;if((r=parseInt(r))<0||r>32)throw new Error("ipaddr: invalid IPv4 prefix length");for(e=[0,0,0,0],n=0,t=Math.floor(r/8);n<t;)e[n]=255,n++;return t<4&&(e[t]=Math.pow(2,r%8)-1<<8-r%8),new this(e)},t.IPv4.broadcastAddressFromCIDR=function(r){var t,n,e,i,o;try{for(e=(t=this.parseCIDR(r))[0].toByteArray(),o=this.subnetMaskFromPrefixLength(t[1]).toByteArray(),i=[],n=0;n<4;)i.push(parseInt(e[n],10)|255^parseInt(o[n],10)),n++;return new this(i)}catch(r){throw r,new Error("ipaddr: the address does not have IPv4 CIDR format")}},t.IPv4.networkAddressFromCIDR=function(r){var t,n,e,i,o;try{for(e=(t=this.parseCIDR(r))[0].toByteArray(),o=this.subnetMaskFromPrefixLength(t[1]).toByteArray(),i=[],n=0;n<4;)i.push(parseInt(e[n],10)&parseInt(o[n],10)),n++;return new this(i)}catch(r){throw r,new Error("ipaddr: the address does not have IPv4 CIDR format")}},t.IPv6.parseCIDR=function(r){var t,n;if((n=r.match(/^(.+)\/(\d+)$/))&&(t=parseInt(n[2]))>=0&&t<=128)return[this.parse(n[1]),t];throw new Error("ipaddr: string is not formatted like an IPv6 CIDR range")},t.isValid=function(r){return t.IPv6.isValid(r)||t.IPv4.isValid(r)},t.parse=function(r){if(t.IPv6.isValid(r))return t.IPv6.parse(r);if(t.IPv4.isValid(r))return t.IPv4.parse(r);throw new Error("ipaddr: the address has neither IPv6 nor IPv4 format")},t.parseCIDR=function(r){try{return t.IPv6.parseCIDR(r)}catch(n){n;try{return t.IPv4.parseCIDR(r)}catch(r){throw r,new Error("ipaddr: the address has neither IPv6 nor IPv4 CIDR format")}}},t.fromByteArray=function(r){var n;if(4===(n=r.length))return new t.IPv4(r);if(16===n)return new t.IPv6(r);throw new Error("ipaddr: the binary input is neither an IPv6 nor IPv4 address")},t.process=function(r){var t;return"ipv6"===(t=this.parse(r)).kind()&&t.isIPv4MappedAddress()?t.toIPv4Address():t}}).call(this);
\ No newline at end of file
diff --git a/lib/ipaddr.js b/lib/ipaddr.js
index c6132ad..c464209 100644
--- a/lib/ipaddr.js
+++ b/lib/ipaddr.js
@@ -556,32 +556,37 @@
   };
 
   ipaddr.IPv4.subnetMaskFromPrefixLength = function(prefix) {
-    var j, octets;
+    var filledOctetCount, j, octets;
+    prefix = parseInt(prefix);
     if (prefix < 0 || prefix > 32) {
-      throw new Error('ipaddr: invalid prefix length');
+      throw new Error('ipaddr: invalid IPv4 prefix length');
     }
-    octets = Array(4).fill(0);
+    octets = [0, 0, 0, 0];
     j = 0;
-    while (j < Math.floor(prefix / 8)) {
+    filledOctetCount = Math.floor(prefix / 8);
+    while (j < filledOctetCount) {
       octets[j] = 255;
       j++;
     }
-    octets[Math.floor(prefix / 8)] = Math.pow(2, prefix % 8) - 1 << 8 - (prefix % 8);
-    return new ipaddr.IPv4(octets);
+    if (filledOctetCount < 4) {
+      octets[filledOctetCount] = Math.pow(2, prefix % 8) - 1 << 8 - (prefix % 8);
+    }
+    return new this(octets);
   };
 
   ipaddr.IPv4.broadcastAddressFromCIDR = function(string) {
-    var error, i, ipInterface, octets, subnetMask;
+    var cidr, error, i, ipInterfaceOctets, octets, subnetMaskOctets;
     try {
-      ipInterface = ipaddr.IPv4.parseCIDR(string)[0];
-      subnetMask = this.subnetMaskFromPrefixLength([ipaddr.IPv4.parseCIDR(string)[1]]);
+      cidr = this.parseCIDR(string);
+      ipInterfaceOctets = cidr[0].toByteArray();
+      subnetMaskOctets = this.subnetMaskFromPrefixLength(cidr[1]).toByteArray();
       octets = [];
       i = 0;
       while (i < 4) {
-        octets.push(parseInt(ipInterface.octets[i], 10) | parseInt(subnetMask.octets[i], 10) ^ 255);
+        octets.push(parseInt(ipInterfaceOctets[i], 10) | parseInt(subnetMaskOctets[i], 10) ^ 255);
         i++;
       }
-      return new ipaddr.IPv4(octets);
+      return new this(octets);
     } catch (error1) {
       error = error1;
       throw new Error('ipaddr: the address does not have IPv4 CIDR format');
@@ -589,17 +594,18 @@
   };
 
   ipaddr.IPv4.networkAddressFromCIDR = function(string) {
-    var error, i, ipInterface, octets, subnetMask;
+    var cidr, error, i, ipInterfaceOctets, octets, subnetMaskOctets;
     try {
-      ipInterface = ipaddr.IPv4.parseCIDR(string)[0];
-      subnetMask = this.subnetMaskFromPrefixLength([ipaddr.IPv4.parseCIDR(string)[1]]);
+      cidr = this.parseCIDR(string);
+      ipInterfaceOctets = cidr[0].toByteArray();
+      subnetMaskOctets = this.subnetMaskFromPrefixLength(cidr[1]).toByteArray();
       octets = [];
       i = 0;
       while (i < 4) {
-        octets.push(parseInt(ipInterface.octets[i], 10) & parseInt(subnetMask.octets[i], 10));
+        octets.push(parseInt(ipInterfaceOctets[i], 10) & parseInt(subnetMaskOctets[i], 10));
         i++;
       }
-      return new ipaddr.IPv4(octets);
+      return new this(octets);
     } catch (error1) {
       error = error1;
       throw new Error('ipaddr: the address does not have IPv4 CIDR format');
diff --git a/src/ipaddr.coffee b/src/ipaddr.coffee
index c62847b..f03a98b 100644
--- a/src/ipaddr.coffee
+++ b/src/ipaddr.coffee
@@ -494,28 +494,32 @@ ipaddr.IPv4.parseCIDR = (string) ->
 
 # A utility function to return subnet mask in IPv4 format given the prefix length
 ipaddr.IPv4.subnetMaskFromPrefixLength = (prefix) ->
+  prefix = parseInt(prefix)
   if prefix < 0 or prefix > 32
-    throw new Error('ipaddr: invalid prefix length')
-  octets = Array(4).fill(0)
+    throw new Error('ipaddr: invalid IPv4 prefix length')
+  octets = [0, 0, 0, 0]
   j = 0
-  while j < Math.floor(prefix / 8)
+  filledOctetCount = Math.floor(prefix / 8)
+  while j < filledOctetCount
     octets[j] = 255
     j++
-  octets[Math.floor(prefix / 8)] = Math.pow(2, (prefix % 8)) - 1 << 8 - (prefix % 8)
-  new (ipaddr.IPv4)(octets)
+  if filledOctetCount < 4
+    octets[filledOctetCount] = Math.pow(2, (prefix % 8)) - 1 << 8 - (prefix % 8)
+  new @(octets)
 
 # A utility function to return broadcast address given the IPv4 interface and prefix length in CIDR notation
 ipaddr.IPv4.broadcastAddressFromCIDR = (string) ->
   try
-    ipInterface = ipaddr.IPv4.parseCIDR(string)[0]
-    subnetMask = @subnetMaskFromPrefixLength([ ipaddr.IPv4.parseCIDR(string)[1] ])
+    cidr = @parseCIDR(string)
+    ipInterfaceOctets = cidr[0].toByteArray()
+    subnetMaskOctets = @subnetMaskFromPrefixLength(cidr[1]).toByteArray()
     octets = []
     i = 0
     while i < 4
       # Broadcast address is bitwise OR between ip interface and inverted mask
-      octets.push parseInt(ipInterface.octets[i], 10) | parseInt(subnetMask.octets[i], 10) ^ 255
+      octets.push parseInt(ipInterfaceOctets[i], 10) | parseInt(subnetMaskOctets[i], 10) ^ 255
       i++
-    return new (ipaddr.IPv4)(octets)
+    return new @(octets)
   catch error
     throw new Error('ipaddr: the address does not have IPv4 CIDR format')
   return
@@ -523,15 +527,16 @@ ipaddr.IPv4.broadcastAddressFromCIDR = (string) ->
 # A utility function to return network address given the IPv4 interface and prefix length in CIDR notation
 ipaddr.IPv4.networkAddressFromCIDR = (string) ->
   try
-    ipInterface = ipaddr.IPv4.parseCIDR(string)[0]
-    subnetMask = @subnetMaskFromPrefixLength([ ipaddr.IPv4.parseCIDR(string)[1] ])
+    cidr = @parseCIDR(string)
+    ipInterfaceOctets = cidr[0].toByteArray()
+    subnetMaskOctets = @subnetMaskFromPrefixLength(cidr[1]).toByteArray()
     octets = []
     i = 0
     while i < 4
       # Network address is bitwise AND between ip interface and mask
-      octets.push parseInt(ipInterface.octets[i], 10) & parseInt(subnetMask.octets[i], 10)
+      octets.push parseInt(ipInterfaceOctets[i], 10) & parseInt(subnetMaskOctets[i], 10)
       i++
-    return new (ipaddr.IPv4)(octets)
+    return new @(octets)
   catch error
     throw new Error('ipaddr: the address does not have IPv4 CIDR format')
   return
diff --git a/test/ipaddr.test.coffee b/test/ipaddr.test.coffee
index 839480d..b42387d 100644
--- a/test/ipaddr.test.coffee
+++ b/test/ipaddr.test.coffee
@@ -401,48 +401,49 @@ module.exports =
     test.equal(ipaddr.IPv6.parse('ffff:0:0:ffff::%z').prefixLengthFromSubnetMask(), null)
     test.done()
 
-  'subnetMaskFromPrefixLength returns correct subnet mask given prefix length': (test) ->
-
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("0"), "0.0.0.0");
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("1"), "128.0.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("2"), "192.0.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("3"), "224.0.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("4"), "240.0.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("5"), "248.0.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("6"), "252.0.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("7"), "254.0.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("8"), "255.0.0.0");
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("9"), "255.128.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("10"), "255.192.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("11"), "255.224.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("12"), "255.240.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("13"), "255.248.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("14"), "255.252.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("15"), "255.254.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("16"), "255.255.0.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("17"), "255.255.128.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("18"), "255.255.192.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("19"), "255.255.224.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("20"), "255.255.240.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("21"), "255.255.248.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("22"), "255.255.252.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("23"), "255.255.254.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("24"), "255.255.255.0")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("25"), "255.255.255.128")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("26"), "255.255.255.192")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("27"), "255.255.255.224")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("28"), "255.255.255.240")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("29"), "255.255.255.248")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("30"), "255.255.255.252")
-    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength("31"), "255.255.255.254")
-    test.done()
-
-  'broadcastAddressFromCIDR returns correct broadcast address': (test) ->
+  'subnetMaskFromPrefixLength returns correct IPv4 subnet mask given prefix length': (test) ->
+
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(0), "0.0.0.0");
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(1), "128.0.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(2), "192.0.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(3), "224.0.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(4), "240.0.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(5), "248.0.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(6), "252.0.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(7), "254.0.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(8), "255.0.0.0");
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(9), "255.128.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(10), "255.192.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(11), "255.224.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(12), "255.240.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(13), "255.248.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(14), "255.252.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(15), "255.254.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(16), "255.255.0.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(17), "255.255.128.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(18), "255.255.192.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(19), "255.255.224.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(20), "255.255.240.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(21), "255.255.248.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(22), "255.255.252.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(23), "255.255.254.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(24), "255.255.255.0")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(25), "255.255.255.128")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(26), "255.255.255.192")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(27), "255.255.255.224")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(28), "255.255.255.240")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(29), "255.255.255.248")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(30), "255.255.255.252")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(31), "255.255.255.254")
+    test.equal(ipaddr.IPv4.subnetMaskFromPrefixLength(32), "255.255.255.255")
+    test.done()
+
+  'broadcastAddressFromCIDR returns correct IPv4 broadcast address': (test) ->
     test.equal(ipaddr.IPv4.broadcastAddressFromCIDR("172.0.0.1/24"), "172.0.0.255")
     test.equal(ipaddr.IPv4.broadcastAddressFromCIDR("172.0.0.1/26"), "172.0.0.63")
     test.done()
 
-  'networkAddressFromCIDR returns correct network address': (test) ->
+  'networkAddressFromCIDR returns correct IPv4 network address': (test) ->
     test.equal(ipaddr.IPv4.networkAddressFromCIDR("172.0.0.1/24"), "172.0.0.0")
     test.equal(ipaddr.IPv4.networkAddressFromCIDR("172.0.0.1/5"), "168.0.0.0")
     test.done()