+ rewrites: support deeper level wildcards - select the more specific one

2020-04-27 17:24:55 +03:00
parent 08b033dd04
commit b33653ec48
3 changed files with 145 additions and 96 deletions
--- a/dnsfilter/rewrites_test.go
+++ b/dnsfilter/rewrites_test.go
@@ -0,0 +1,127 @@
+package dnsfilter
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRewrites(t *testing.T) {
+	d := Dnsfilter{}
+	// CNAME, A, AAAA
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"somecname", "somehost.com", 0, nil},
+		RewriteEntry{"somehost.com", "0.0.0.0", 0, nil},
+
+		RewriteEntry{"host.com", "1.2.3.4", 0, nil},
+		RewriteEntry{"host.com", "1.2.3.5", 0, nil},
+		RewriteEntry{"host.com", "1:2:3::4", 0, nil},
+		RewriteEntry{"www.host.com", "host.com", 0, nil},
+	}
+	d.prepareRewrites()
+	r := d.processRewrites("host2.com")
+	assert.Equal(t, NotFilteredNotFound, r.Reason)
+
+	r = d.processRewrites("www.host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, "host.com", r.CanonName)
+	assert.True(t, len(r.IPList) == 3)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+	assert.True(t, r.IPList[1].Equal(net.ParseIP("1.2.3.5")))
+	assert.True(t, r.IPList[2].Equal(net.ParseIP("1:2:3::4")))
+
+	// wildcard
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"host.com", "1.2.3.4", 0, nil},
+		RewriteEntry{"*.host.com", "1.2.3.5", 0, nil},
+	}
+	d.prepareRewrites()
+	r = d.processRewrites("host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+
+	r = d.processRewrites("www.host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.5")))
+
+	r = d.processRewrites("www.host2.com")
+	assert.Equal(t, NotFilteredNotFound, r.Reason)
+
+	// override a wildcard
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"a.host.com", "1.2.3.4", 0, nil},
+		RewriteEntry{"*.host.com", "1.2.3.5", 0, nil},
+	}
+	d.prepareRewrites()
+	r = d.processRewrites("a.host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.True(t, len(r.IPList) == 1)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+
+	// wildcard + CNAME
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"host.com", "1.2.3.4", 0, nil},
+		RewriteEntry{"*.host.com", "host.com", 0, nil},
+	}
+	d.prepareRewrites()
+	r = d.processRewrites("www.host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, "host.com", r.CanonName)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+
+	// 2 CNAMEs
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"b.host.com", "a.host.com", 0, nil},
+		RewriteEntry{"a.host.com", "host.com", 0, nil},
+		RewriteEntry{"host.com", "1.2.3.4", 0, nil},
+	}
+	d.prepareRewrites()
+	r = d.processRewrites("b.host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, "host.com", r.CanonName)
+	assert.True(t, len(r.IPList) == 1)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+
+	// 2 CNAMEs + wildcard
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"b.host.com", "a.host.com", 0, nil},
+		RewriteEntry{"a.host.com", "x.somehost.com", 0, nil},
+		RewriteEntry{"*.somehost.com", "1.2.3.4", 0, nil},
+	}
+	d.prepareRewrites()
+	r = d.processRewrites("b.host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, "x.somehost.com", r.CanonName)
+	assert.True(t, len(r.IPList) == 1)
+	assert.True(t, r.IPList[0].Equal(net.ParseIP("1.2.3.4")))
+}
+
+func TestRewritesLevels(t *testing.T) {
+	d := Dnsfilter{}
+	// exact host, wildcard L2, wildcard L3
+	d.Rewrites = []RewriteEntry{
+		RewriteEntry{"host.com", "1.1.1.1", 0, nil},
+		RewriteEntry{"*.host.com", "2.2.2.2", 0, nil},
+		RewriteEntry{"*.sub.host.com", "3.3.3.3", 0, nil},
+	}
+	d.prepareRewrites()
+
+	// match exact
+	r := d.processRewrites("host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, 1, len(r.IPList))
+	assert.Equal(t, "1.1.1.1", r.IPList[0].String())
+
+	// match L2
+	r = d.processRewrites("sub.host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, 1, len(r.IPList))
+	assert.Equal(t, "2.2.2.2", r.IPList[0].String())
+
+	// match L3
+	r = d.processRewrites("my.sub.host.com")
+	assert.Equal(t, ReasonRewrite, r.Reason)
+	assert.Equal(t, 1, len(r.IPList))
+	assert.Equal(t, "3.3.3.3", r.IPList[0].String())
+}