From c1383a33568943c74be32e8aa718780bbd05d654 Mon Sep 17 00:00:00 2001 From: Adrien Rey-Jarthon Date: Mon, 20 Apr 2026 09:20:39 +0200 Subject: [PATCH] Fix private?, link_local? and loopback? methods to avoid mistaking public IPv6 as IPv4-mapped --- lib/ipaddr.rb | 10 +++++----- test/test_ipaddr.rb | 10 ++++++++++ 2 files changed, 15 insertions(+), 5 deletions(-) diff --git a/lib/ipaddr.rb b/lib/ipaddr.rb index 6b67d7e..cc55089 100644 --- a/lib/ipaddr.rb +++ b/lib/ipaddr.rb @@ -293,7 +293,7 @@ def loopback? @addr & 0xff000000 == 0x7f000000 # 127.0.0.1/8 when Socket::AF_INET6 @addr == 1 || # ::1 - (@addr & 0xffff_0000_0000 == 0xffff_0000_0000 && ( + (@addr >> 32 == 0xffff && ( @addr & 0xff000000 == 0x7f000000 # ::ffff:127.0.0.1/8 )) else @@ -314,10 +314,10 @@ def private? @addr & 0xffff0000 == 0xc0a80000 # 192.168.0.0/16 when Socket::AF_INET6 @addr & 0xfe00_0000_0000_0000_0000_0000_0000_0000 == 0xfc00_0000_0000_0000_0000_0000_0000_0000 || - (@addr & 0xffff_0000_0000 == 0xffff_0000_0000 && ( + (@addr >> 32 == 0xffff && ( @addr & 0xff000000 == 0x0a000000 || # ::ffff:10.0.0.0/8 - @addr & 0xfff00000 == 0xac100000 || # ::ffff::172.16.0.0/12 - @addr & 0xffff0000 == 0xc0a80000 # ::ffff::192.168.0.0/16 + @addr & 0xfff00000 == 0xac100000 || # ::ffff:172.16.0.0/12 + @addr & 0xffff0000 == 0xc0a80000 # ::ffff:192.168.0.0/16 )) else raise AddressFamilyError, "unsupported address family" @@ -335,7 +335,7 @@ def link_local? @addr & 0xffff0000 == 0xa9fe0000 # 169.254.0.0/16 when Socket::AF_INET6 @addr & 0xffc0_0000_0000_0000_0000_0000_0000_0000 == 0xfe80_0000_0000_0000_0000_0000_0000_0000 || # fe80::/10 - (@addr & 0xffff_0000_0000 == 0xffff_0000_0000 && ( + (@addr >> 32 == 0xffff && ( @addr & 0xffff0000 == 0xa9fe0000 # ::ffff:169.254.0.0/16 )) else diff --git a/test/test_ipaddr.rb b/test/test_ipaddr.rb index 4b7229f..c00626e 100644 --- a/test/test_ipaddr.rb +++ b/test/test_ipaddr.rb @@ -533,6 +533,9 @@ def test_loopback? assert_equal(false, IPAddr.new('::ffff:0.0.0.0').loopback?) assert_equal(false, IPAddr.new('::ffff:192.168.2.0').loopback?) assert_equal(false, IPAddr.new('::ffff:255.0.0.0').loopback?) + + # Global unicast addresses with 0xffff in group 5 must not be mistaken for ::ffff:127.x.x.x + assert_equal(false, IPAddr.new('2001:db8:1:1:0:ffff:7f00:1').loopback?) end def test_private? @@ -583,6 +586,10 @@ def test_private? assert_equal(false, IPAddr.new('::ffff:192.169.0.0').private?) assert_equal(false, IPAddr.new('::ffff:169.254.0.1').private?) + + # Global unicast addresses with 0xffff in group 5 must not be mistaken for ::ffff:10/172.16/192.168.x + assert_equal(false, IPAddr.new('2001:718:1404:c8:0:ffff:ac19:c80e').private?) + assert_equal(false, IPAddr.new('2001:db8:1:1:0:ffff:c0a8:1').private?) end def test_link_local? @@ -609,6 +616,9 @@ def test_link_local? assert_equal(true, IPAddr.new('::ffff:169.254.1.1').link_local?) assert_equal(true, IPAddr.new('::ffff:169.254.254.255').link_local?) + + # Global unicast addresses with 0xffff in group 5 must not be mistaken for ::ffff:169.254.x.x + assert_equal(false, IPAddr.new('2001:db8:1:1:0:ffff:a9fe:101').link_local?) end def test_hash