sys/linux: improve AF_ALG alg name generation

There is effectively infinite number of possible crypto
algorithm names due to templates. Plus there is tricky
relation between algorithms and algorithm type names.

This change adds custom mutator for sockaddr_alg struct
to improve variance in generated algorithms.

1 files changed, 215 insertions, 0 deletions

diff --git a/sys/linux/alg_test.go b/sys/linux/alg_test.go
new file mode 100644
index 000000000..b3622a6c9
--- /dev/null
+++ b/sys/linux/alg_test.go
@@ -0,0 +1,215 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+// +build linux
+
+package linux
+
+import (
+	"flag"
+	"fmt"
+	"math/rand"
+	"strings"
+	"syscall"
+	"testing"
+	"unsafe"
+)
+
+// AF_ALG tests won't generally pass and intended for manual testing.
+// First, they require fresh kernel with _all_ crypto algorithms enabled.
+// Second, they require the newest hardware with all of SSE/AVX.
+// Finally, they still won't pass because some algorithms are arch-dependent.
+var flagRunAlgTests = flag.Bool("algtests", false, "run AF_ALG tests")
+
+func algTest(t *testing.T) {
+	if !*flagRunAlgTests {
+		t.Skip()
+	}
+	t.Parallel()
+}
+
+// TestAlgDescriptions checks that there are no duplicate names and that
+// templates mentioned in complete algorithms are also present as standalone templates.
+func TestAlgDescriptions(t *testing.T) {
+	algTest(t)
+	allall := make(map[string]bool)
+	for typ, algList := range allAlgs {
+		algs := make(map[string]bool)
+		templates := make(map[string]bool)
+		for _, alg := range algList {
+			allall[alg.name] = true
+			if algs[alg.name] {
+				t.Errorf("duplicate: %v", alg.name)
+			}
+			algs[alg.name] = true
+			if len(alg.args) > 0 {
+				templates[alg.name] = true
+			}
+		}
+		for _, alg := range algList {
+			if len(alg.args) > 0 || strings.HasPrefix(alg.name, "__") {
+				continue
+			}
+			brace := strings.IndexByte(alg.name, '(')
+			if brace == -1 {
+				continue
+			}
+			templ := alg.name[:brace]
+			if !templates[templ] {
+				t.Errorf("template %v is missing for type %v", templ, typ)
+			}
+			templates[templ] = true
+		}
+	}
+}
+
+// TestSingleAlg tests creation of all algorithms (not templates).
+func TestSingleAlg(t *testing.T) {
+	algTest(t)
+	for _, typ := range allTypes {
+		for _, alg := range allAlgs[typ.typ] {
+			if len(alg.args) != 0 {
+				continue
+			}
+			ok, skip := testAlg(t, typ.name, alg.name)
+			if skip {
+				t.Errorf("SKIP\t%10v\t%v", typ.name, alg.name)
+				continue
+			}
+			if !ok {
+				t.Errorf("FAIL\t%10v\t%v", typ.name, alg.name)
+				continue
+			}
+		}
+	}
+}
+
+// TestTemplateAlg1 tests creation of all templates with 1 argument.
+func TestTemplateAlg1(t *testing.T) {
+	algTest(t)
+	for _, typ := range allTypes {
+		for _, alg := range allAlgs[typ.typ] {
+			if len(alg.args) != 1 {
+				continue
+			}
+			var works []int
+		nextType:
+			for typ1, algs1 := range allAlgs {
+				var selection []algDesc
+				for _, x := range rand.Perm(len(algs1)) {
+					if len(algs1[x].args) != 0 {
+						continue
+					}
+					selection = append(selection, algs1[x])
+					if len(selection) == 10 {
+						break
+					}
+				}
+				for _, alg1 := range selection {
+					name := fmt.Sprintf("%v(%v)", alg.name, alg1.name)
+					ok, _ := testAlg(t, typ.name, name)
+					if ok {
+						works = append(works, typ1)
+						continue nextType
+					}
+				}
+			}
+			if len(works) == 1 && works[0] == alg.args[0] {
+				continue
+			}
+			t.Errorf("FAIL\t%10v\t%v\tclaimed %v works with %v",
+				typ.name, alg.name, alg.args[0], works)
+		}
+	}
+}
+
+// TestTemplateAlg2 tests creation of all templates with 2 argument.
+func TestTemplateAlg2(t *testing.T) {
+	algTest(t)
+	// Can't affort to test all permutations of 2 algorithms,
+	// 20 algorithm pairs for each type pair and use them.
+	selections := make(map[int][]int)
+	for typ1, algs1 := range allAlgs {
+		for typ2, algs2 := range allAlgs {
+			var pairs []int
+			for i1, alg1 := range algs1 {
+				if len(alg1.args) != 0 {
+					continue
+				}
+				for i2, alg2 := range algs2 {
+					if len(alg2.args) != 0 {
+						continue
+					}
+					pairs = append(pairs, i1*1000+i2)
+				}
+			}
+			var selection []int
+			for _, x := range rand.Perm(len(pairs)) {
+				selection = append(selection, pairs[x])
+				if len(selection) > 20 {
+					break
+				}
+			}
+			selections[typ1*1000+typ2] = selection
+		}
+	}
+	for _, typ := range allTypes {
+		for _, alg := range allAlgs[typ.typ] {
+			if len(alg.args) != 2 {
+				continue
+			}
+			for typ1, algs1 := range allAlgs {
+				for typ2, algs2 := range allAlgs {
+					selection := selections[typ1*1000+typ2]
+					for _, x := range selection {
+						alg1 := algs1[x/1000]
+						alg2 := algs2[x%1000]
+						name := fmt.Sprintf("%v(%v,%v)",
+							alg.name, alg1.name, alg2.name)
+						if ok, _ := testAlg(t, typ.name, name); ok {
+							t.Logf("%10v\t%v\tclaimed %v works with %v/%v (%v)",
+								typ.name, alg.name, alg.args, typ1, typ2, name)
+							break
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+type sockaddrAlg struct {
+	family uint16
+	typ    [14]byte
+	feat   uint32
+	mask   uint32
+	name   [64]byte
+}
+
+func testAlg(t *testing.T, typ, name string) (ok, skip bool) {
+	const AF_ALG = 0x26
+	addr := &sockaddrAlg{
+		family: AF_ALG,
+	}
+	if len(typ) >= int(unsafe.Sizeof(addr.typ)) ||
+		len(name) >= int(unsafe.Sizeof(addr.name)) {
+		return false, true
+	}
+	for i := 0; i < len(typ); i++ {
+		addr.typ[i] = typ[i]
+	}
+	for i := 0; i < len(name); i++ {
+		addr.name[i] = name[i]
+	}
+	sock, err := syscall.Socket(AF_ALG, syscall.SOCK_SEQPACKET, 0)
+	if err != nil {
+		t.Fatalf("failed to create AF_ALG socket: %v", err)
+	}
+	defer syscall.Close(sock)
+	_, _, errno := syscall.Syscall(syscall.SYS_BIND, uintptr(sock),
+		uintptr(unsafe.Pointer(addr)), unsafe.Sizeof(*addr))
+	if errno != 0 {
+		return false, false
+	}
+	return true, false
+}