absorb go-maddr-filter; rm stale Makefile targets; upgrade deps (#124)

Makefile

@@ -1,17 +1,3 @@
-gx:
-	go get github.com/whyrusleeping/gx
-	go get github.com/whyrusleeping/gx-go
-
-covertools:
-	go get golang.org/x/tools/cmd/cover
-
-deps: gx covertools
-	gx --verbose install --global
-	gx-go rewrite
-
-publish:
-	gx-go rewrite --undo
-
 conformance: tmp/multiaddr
 	go build -o tmp/multiaddr/test/go-multiaddr ./multiaddr
 	cd tmp/multiaddr/test && MULTIADDR_BIN="./go-multiaddr" go test -v
@@ -23,4 +9,4 @@ tmp/multiaddr:
 clean:
 	rm -rf tmp/
 
-.PHONY: gx covertools deps publish conformance clean
+.PHONY: conformance clean

filter.go

@@ -0,0 +1,179 @@
+package multiaddr
+
+import (
+	"net"
+	"sync"
+)
+
+// Action is an enum modelling all possible filter actions.
+type Action int32
+
+const (
+	ActionNone Action = iota // zero value.
+	ActionAccept
+	ActionDeny
+)
+
+type filterEntry struct {
+	f      net.IPNet
+	action Action
+}
+
+// Filters is a structure representing a collection of accept/deny
+// net.IPNet filters, together with the DefaultAction flag, which
+// represents the default filter policy.
+//
+// Note that the last policy added to the Filters is authoritative.
+type Filters struct {
+	DefaultAction Action
+
+	mu      sync.RWMutex
+	filters []*filterEntry
+}
+
+// NewFilters constructs and returns a new set of net.IPNet filters.
+// By default, the new filter accepts all addresses.
+func NewFilters() *Filters {
+	return &Filters{
+		DefaultAction: ActionAccept,
+		filters:       make([]*filterEntry, 0),
+	}
+}
+
+func (fs *Filters) find(ipnet net.IPNet) (int, *filterEntry) {
+	s := ipnet.String()
+	for idx, ft := range fs.filters {
+		if ft.f.String() == s {
+			return idx, ft
+		}
+	}
+	return -1, nil
+}
+
+// AddDialFilter adds a deny rule to this Filters set. Hosts
+// matching the given net.IPNet filter will be denied, unless
+// another rule is added which states that they should be accepted.
+//
+// No effort is made to prevent duplication of filters, or to simplify
+// the filters list.
+//
+// Deprecated: Use AddFilter().
+func (fs *Filters) AddDialFilter(f *net.IPNet) {
+	fs.AddFilter(*f, ActionDeny)
+}
+
+// AddFilter adds a rule to the Filters set, enforcing the desired action for
+// the provided IPNet mask.
+func (fs *Filters) AddFilter(ipnet net.IPNet, action Action) {
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
+
+	if _, f := fs.find(ipnet); f != nil {
+		f.action = action
+	} else {
+		fs.filters = append(fs.filters, &filterEntry{ipnet, action})
+	}
+}
+
+// RemoveLiteral removes the first filter associated with the supplied IPNet,
+// returning whether something was removed or not. It makes no distinction
+// between whether the rule is an accept or a deny.
+//
+// Deprecated: use RemoveLiteral() instead.
+func (fs *Filters) Remove(ipnet *net.IPNet) (removed bool) {
+	return fs.RemoveLiteral(*ipnet)
+}
+
+// RemoveLiteral removes the first filter associated with the supplied IPNet,
+// returning whether something was removed or not. It makes no distinction
+// between whether the rule is an accept or a deny.
+func (fs *Filters) RemoveLiteral(ipnet net.IPNet) (removed bool) {
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
+
+	if idx, _ := fs.find(ipnet); idx != -1 {
+		fs.filters = append(fs.filters[:idx], fs.filters[idx+1:]...)
+		return true
+	}
+	return false
+}
+
+// AddrBlocked parses a ma.Multiaddr and, if a valid netip is found, it applies the
+// Filter set rules, returning true if the given address should be denied, and false if
+// the given address is accepted.
+//
+// If a parsing error occurs, or no filter matches, the Filters'
+// default is returned.
+//
+// TODO: currently, the last filter to match wins always, but it shouldn't be that way.
+//  Instead, the highest-specific last filter should win; that way more specific filters
+//  override more general ones.
+func (fs *Filters) AddrBlocked(a Multiaddr) (deny bool) {
+	var (
+		netip net.IP
+		found bool
+	)
+
+	ForEach(a, func(c Component) bool {
+		switch c.Protocol().Code {
+		case P_IP6ZONE:
+			return true
+		case P_IP6, P_IP4:
+			found = true
+			netip = net.IP(c.RawValue())
+			return false
+		default:
+			return false
+		}
+	})
+
+	if !found {
+		return fs.DefaultAction == ActionDeny
+	}
+
+	fs.mu.RLock()
+	defer fs.mu.RUnlock()
+
+	action := fs.DefaultAction
+	for _, ft := range fs.filters {
+		if ft.f.Contains(netip) {
+			action = ft.action
+		}
+	}
+
+	return action == ActionDeny
+}
+
+// Filters returns the list of DENY net.IPNet masks. For backwards compatibility.
+//
+// A copy of the filters is made prior to returning, so the inner state is not exposed.
+//
+// Deprecated: Use FiltersForAction().
+func (fs *Filters) Filters() (result []*net.IPNet) {
+	ffa := fs.FiltersForAction(ActionDeny)
+	for _, res := range ffa {
+		res := res // allocate a new copy
+		result = append(result, &res)
+	}
+	return result
+}
+
+func (fs *Filters) ActionForFilter(ipnet net.IPNet) (action Action, ok bool) {
+	if _, f := fs.find(ipnet); f != nil {
+		return f.action, true
+	}
+	return ActionNone, false
+}
+
+// FiltersForAction returns the filters associated with the indicated action.
+func (fs *Filters) FiltersForAction(action Action) (result []net.IPNet) {
+	fs.mu.RLock()
+	defer fs.mu.RUnlock()
+
+	for _, ff := range fs.filters {
+		if ff.action == action {
+			result = append(result, ff.f)
+		}
+	}
+	return result
+}

filter_test.go

@@ -0,0 +1,202 @@
+package multiaddr
+
+import (
+	"net"
+	"testing"
+)
+
+func TestFilterListing(t *testing.T) {
+	f := NewFilters()
+	expected := map[string]bool{
+		"1.2.3.0/24":  true,
+		"4.3.2.1/32":  true,
+		"fd00::/8":    true,
+		"fc00::1/128": true,
+	}
+	for cidr := range expected {
+		_, ipnet, _ := net.ParseCIDR(cidr)
+		f.AddDialFilter(ipnet)
+	}
+
+	for _, filter := range f.Filters() {
+		cidr := filter.String()
+		if expected[cidr] {
+			delete(expected, cidr)
+		} else {
+			t.Errorf("unexected filter %s", cidr)
+		}
+	}
+	for cidr := range expected {
+		t.Errorf("expected filter %s", cidr)
+	}
+}
+
+func TestFilterBlocking(t *testing.T) {
+	f := NewFilters()
+
+	_, ipnet, _ := net.ParseCIDR("0.1.2.3/24")
+	f.AddDialFilter(ipnet)
+	filters := f.Filters()
+	if len(filters) != 1 {
+		t.Fatal("Expected only 1 filter")
+	}
+
+	if a, ok := f.ActionForFilter(*ipnet); !ok || a != ActionDeny {
+		t.Fatal("Expected filter with DENY action")
+	}
+
+	if !f.RemoveLiteral(*filters[0]) {
+		t.Error("expected true value from RemoveLiteral")
+	}
+
+	for _, cidr := range []string{
+		"1.2.3.0/24",
+		"4.3.2.1/32",
+		"fd00::/8",
+		"fc00::1/128",
+	} {
+		_, ipnet, _ := net.ParseCIDR(cidr)
+		f.AddDialFilter(ipnet)
+	}
+
+	// These addresses should all be blocked
+	for _, blocked := range []string{
+		"/ip4/1.2.3.4/tcp/123",
+		"/ip4/4.3.2.1/udp/123",
+		"/ip6/fd00::2/tcp/321",
+		"/ip6/fc00::1/udp/321",
+	} {
+		maddr, err := NewMultiaddr(blocked)
+		if err != nil {
+			t.Error(err)
+		}
+		if !f.AddrBlocked(maddr) {
+			t.Fatalf("expected %s to be blocked", blocked)
+		}
+	}
+
+	// test that other net intervals are not blocked
+	for _, addr := range []string{
+		"/ip4/1.2.4.1/tcp/123",
+		"/ip4/4.3.2.2/udp/123",
+		"/ip6/fe00::1/tcp/321",
+		"/ip6/fc00::2/udp/321",
+	} {
+		maddr, err := NewMultiaddr(addr)
+		if err != nil {
+			t.Error(err)
+		}
+		if f.AddrBlocked(maddr) {
+			t.Fatalf("expected %s to not be blocked", addr)
+		}
+	}
+}
+
+func TestFilterWhitelisting(t *testing.T) {
+	f := NewFilters()
+
+	// Add default reject filter
+	f.DefaultAction = ActionDeny
+
+	// Add a whitelist
+	_, ipnet, _ := net.ParseCIDR("1.2.3.0/24")
+	f.AddFilter(*ipnet, ActionAccept)
+
+	if a, ok := f.ActionForFilter(*ipnet); !ok || a != ActionAccept {
+		t.Fatal("Expected filter with ACCEPT action")
+	}
+
+	// That /24 should now be allowed
+	for _, addr := range []string{
+		"/ip4/1.2.3.1/tcp/123",
+		"/ip4/1.2.3.254/tcp/123",
+		"/ip4/1.2.3.254/udp/321",
+	} {
+		maddr, err := NewMultiaddr(addr)
+		if err != nil {
+			t.Error(err)
+		}
+		if f.AddrBlocked(maddr) {
+			t.Fatalf("expected %s to be whitelisted", addr)
+		}
+	}
+
+	// No policy matches these maddrs, they should be blocked by default
+	for _, blocked := range []string{
+		"/ip4/1.2.4.4/tcp/123",
+		"/ip4/4.3.2.1/udp/123",
+		"/ip6/fd00::2/tcp/321",
+		"/ip6/fc00::1/udp/321",
+	} {
+		maddr, err := NewMultiaddr(blocked)
+		if err != nil {
+			t.Error(err)
+		}
+		if !f.AddrBlocked(maddr) {
+			t.Fatalf("expected %s to be blocked", blocked)
+		}
+	}
+}
+
+func TestFiltersRemoveRules(t *testing.T) {
+	f := NewFilters()
+
+	ips := []string{
+		"/ip4/1.2.3.1/tcp/123",
+		"/ip4/1.2.3.254/tcp/123",
+	}
+
+	// Add default reject filter
+	f.DefaultAction = ActionDeny
+
+	// Add whitelisting
+	_, ipnet, _ := net.ParseCIDR("1.2.3.0/24")
+	f.AddFilter(*ipnet, ActionAccept)
+
+	if a, ok := f.ActionForFilter(*ipnet); !ok || a != ActionAccept {
+		t.Fatal("Expected filter with ACCEPT action")
+	}
+
+	// these are all whitelisted, should be OK
+	for _, addr := range ips {
+		maddr, err := NewMultiaddr(addr)
+		if err != nil {
+			t.Error(err)
+		}
+		if f.AddrBlocked(maddr) {
+			t.Fatalf("expected %s to be whitelisted", addr)
+		}
+	}
+
+	// Test removing the filter. It'll remove multiple, so make a dupe &
+	// a complement
+	f.AddDialFilter(ipnet)
+
+	// Show that they all apply, these are now blacklisted & should fail
+	for _, addr := range ips {
+		maddr, err := NewMultiaddr(addr)
+		if err != nil {
+			t.Error(err)
+		}
+		if !f.AddrBlocked(maddr) {
+			t.Fatalf("expected %s to be blacklisted", addr)
+		}
+	}
+
+	// remove those rules
+	if !f.RemoveLiteral(*ipnet) {
+		t.Error("expected true value from RemoveLiteral")
+	}
+
+	// our default is reject, so the 1.2.3.0/24 should be rejected now,
+	// along with everything else
+	for _, addr := range ips {
+		maddr, err := NewMultiaddr(addr)
+		if err != nil {
+			t.Error(err)
+		}
+		if !f.AddrBlocked(maddr) {
+			t.Fatalf("expected %s to be blocked", addr)
+		}
+	}
+}

go.mod

@@ -1,8 +1,8 @@
 module github.com/multiformats/go-multiaddr
 
+go 1.13
+
 require (
 	github.com/multiformats/go-multihash v0.0.13
-	github.com/multiformats/go-varint v0.0.2
+	github.com/multiformats/go-varint v0.0.5
 )
-
-go 1.13

go.sum

@@ -2,20 +2,10 @@ github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1 h1:lYpkrQH5ajf0
 github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1/go.mod h1:pD8RvIylQ358TN4wwqatJ8rNavkEINozVn9DtGI3dfQ=
 github.com/minio/sha256-simd v0.1.1-0.20190913151208-6de447530771 h1:MHkK1uRtFbVqvAgvWxafZe54+5uBxLluGylDiKgdhwo=
 github.com/minio/sha256-simd v0.1.1-0.20190913151208-6de447530771/go.mod h1:B5e1o+1/KgNmWrSQK08Y6Z1Vb5pwIktudl0J58iy0KM=
-github.com/mr-tron/base58 v1.1.2 h1:ZEw4I2EgPKDJ2iEw0cNmLB3ROrEmkOtXIkaG7wZg+78=
-github.com/mr-tron/base58 v1.1.2/go.mod h1:BinMc/sQntlIE1frQmRFPUoPA1Zkr8VRgBdjWI2mNwc=
 github.com/mr-tron/base58 v1.1.3 h1:v+sk57XuaCKGXpWtVBX8YJzO7hMGx4Aajh4TQbdEFdc=
 github.com/mr-tron/base58 v1.1.3/go.mod h1:BinMc/sQntlIE1frQmRFPUoPA1Zkr8VRgBdjWI2mNwc=
-github.com/multiformats/go-multihash v0.0.8 h1:wrYcW5yxSi3dU07n5jnuS5PrNwyHy0zRHGVoUugWvXg=
-github.com/multiformats/go-multihash v0.0.8/go.mod h1:YSLudS+Pi8NHE7o6tb3D8vrpKa63epEDmG8nTduyAew=
-github.com/multiformats/go-multihash v0.0.10 h1:lMoNbh2Ssd9PUF74Nz008KGzGPlfeV6wH3rit5IIGCM=
-github.com/multiformats/go-multihash v0.0.10/go.mod h1:YSLudS+Pi8NHE7o6tb3D8vrpKa63epEDmG8nTduyAew=
 github.com/multiformats/go-multihash v0.0.13 h1:06x+mk/zj1FoMsgNejLpy6QTvJqlSt/BhLEy87zidlc=
 github.com/multiformats/go-multihash v0.0.13/go.mod h1:VdAWLKTwram9oKAatUcLxBNUjdtcVwxObEQBtRfuyjc=
-github.com/multiformats/go-varint v0.0.1 h1:TR/0rdQtnNxuN2IhiB639xC3tWM4IUi7DkTBVTdGW/M=
-github.com/multiformats/go-varint v0.0.1/go.mod h1:3Ls8CIEsrijN6+B7PbrXRPxHRPuXSrVKRY101jdMZYE=
-github.com/multiformats/go-varint v0.0.2 h1:6sUvyh2YHpJCb8RZ6eYzj6iJQ4+chWYmyIHxszqlPTA=
-github.com/multiformats/go-varint v0.0.2/go.mod h1:3Ls8CIEsrijN6+B7PbrXRPxHRPuXSrVKRY101jdMZYE=
 github.com/multiformats/go-varint v0.0.5 h1:XVZwSo04Cs3j/jS0uAEPpT3JY6DzMcVLLoWOSnCxOjg=
 github.com/multiformats/go-varint v0.0.5/go.mod h1:3Ls8CIEsrijN6+B7PbrXRPxHRPuXSrVKRY101jdMZYE=
 github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=