pkg/host: move machine info functionality from syz-fuzzer

It's better to keep functionality in packages rather than in main.
It makes it reusable and better organized.
Move machine info functionality to pkg/host and do some cosmetic refactoring.

3 files changed, 305 insertions, 0 deletions

diff --git a/pkg/host/machine_info.go b/pkg/host/machine_info.go
new file mode 100644
index 000000000..7a7cd2612
--- /dev/null
+++ b/pkg/host/machine_info.go
@@ -0,0 +1,34 @@
+// Copyright 2020 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.
+
+package host
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"strings"
+)
+
+func CollectMachineInfo() ([]byte, error) {
+	buf := new(bytes.Buffer)
+	for _, pair := range machineInfoFuncs {
+		fmt.Fprintf(buf, "[%s]\n", pair.name)
+		err := pair.fn(buf)
+		if err != nil {
+			if !os.IsNotExist(err) {
+				return nil, err
+			}
+			fmt.Fprintf(buf, "%v\n", err)
+		}
+		fmt.Fprintf(buf, "%v\n\n", strings.Repeat("-", 80))
+	}
+	return buf.Bytes(), nil
+}
+
+var machineInfoFuncs []machineInfoFunc
+
+type machineInfoFunc struct {
+	name string
+	fn   func(*bytes.Buffer) error
+}
diff --git a/pkg/host/machine_info_linux.go b/pkg/host/machine_info_linux.go
new file mode 100644
index 000000000..da1ee481a
--- /dev/null
+++ b/pkg/host/machine_info_linux.go
@@ -0,0 +1,122 @@
+// Copyright 2020 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.
+
+package host
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func init() {
+	machineInfoFuncs = []machineInfoFunc{
+		{"CPU Info", readCPUInfo},
+		{"KVM", readKVMInfo},
+	}
+}
+
+func readCPUInfo(buffer *bytes.Buffer) error {
+	file, err := os.Open("/proc/cpuinfo")
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	scanCPUInfo(buffer, scanner)
+	return nil
+}
+
+func scanCPUInfo(buffer *bytes.Buffer, scanner *bufio.Scanner) {
+	keyIndices := make(map[string]int)
+	type keyValues struct {
+		key    string
+		values []string
+	}
+	var info []keyValues
+
+	for scanner.Scan() {
+		splitted := strings.Split(scanner.Text(), ":")
+		if len(splitted) != 2 {
+			continue
+		}
+		key := strings.TrimSpace(splitted[0])
+		val := strings.TrimSpace(splitted[1])
+
+		if idx, ok := keyIndices[key]; !ok {
+			idx = len(keyIndices)
+			keyIndices[key] = idx
+			info = append(info, keyValues{key, []string{val}})
+		} else {
+			info[idx].values = append(info[idx].values, val)
+		}
+	}
+
+	for _, kv := range info {
+		// It is guaranteed that len(vals) >= 1
+		key := kv.key
+		vals := kv.values
+		if allEqual(vals) {
+			fmt.Fprintf(buffer, "%-20s: %s\n", key, vals[0])
+		} else {
+			fmt.Fprintf(buffer, "%-20s: %s\n", key, strings.Join(vals, ", "))
+		}
+	}
+}
+
+func allEqual(slice []string) bool {
+	if len(slice) == 0 {
+		return true
+	}
+	for i := 1; i < len(slice); i++ {
+		if slice[i] != slice[0] {
+			return false
+		}
+	}
+	return true
+}
+
+func readKVMInfo(buffer *bytes.Buffer) error {
+	files, err := ioutil.ReadDir("/sys/module/")
+	if err != nil {
+		return err
+	}
+
+	for _, file := range files {
+		name := file.Name()
+		if !strings.HasPrefix(name, "kvm") {
+			continue
+		}
+
+		paramPath := filepath.Join("/sys", "module", name, "parameters")
+		params, err := ioutil.ReadDir(paramPath)
+		if err != nil {
+			if os.IsNotExist(err) {
+				continue
+			}
+			return err
+		}
+
+		if len(params) == 0 {
+			continue
+		}
+
+		fmt.Fprintf(buffer, "/sys/module/%s:\n", name)
+		for _, key := range params {
+			keyName := key.Name()
+			data, err := ioutil.ReadFile(filepath.Join(paramPath, keyName))
+			if err != nil {
+				return err
+			}
+			fmt.Fprintf(buffer, "\t%s: ", keyName)
+			buffer.Write(data)
+		}
+		buffer.WriteByte('\n')
+	}
+	return nil
+}
diff --git a/pkg/host/machine_info_test.go b/pkg/host/machine_info_test.go
new file mode 100644
index 000000000..49ef93fe0
--- /dev/null
+++ b/pkg/host/machine_info_test.go
@@ -0,0 +1,149 @@
+// Copyright 2020 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.
+
+package host
+
+import (
+	"bufio"
+	"bytes"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+func TestMachineInfoLinux(t *testing.T) {
+	if runtime.GOOS != "linux" {
+		t.Skip()
+	}
+	result, err := CollectMachineInfo()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	scanner := bufio.NewScanner(bytes.NewReader(result))
+
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		if line == "[CPU Info]" {
+			checkCPUInfo(t, scanner)
+		}
+		if line == "[KVM]" {
+			checkKVMInfo(t, scanner)
+		}
+	}
+}
+
+func checkCPUInfo(t *testing.T, scanner *bufio.Scanner) {
+	keys := make(map[string]bool)
+	for scanner.Scan() {
+		line := scanner.Text()
+		// End of CPU Info section.
+		if strings.HasPrefix(line, "-----") {
+			break
+		}
+		splitted := strings.Split(line, ":")
+		if len(splitted) != 2 {
+			t.Fatalf("the format of line \"%s\" is not correct", line)
+		}
+		key := strings.TrimSpace(splitted[0])
+		keys[key] = true
+	}
+
+	importantKeys := [][]string{
+		{"vendor", "vendor_id", "CPU implementer"},
+		{"model", "CPU part", "cpu model"},
+		{"flags", "features", "Features", "ASEs implemented", "type"},
+	}
+	for _, possibleNames := range importantKeys {
+		exists := false
+		for _, name := range possibleNames {
+			if keys[name] {
+				exists = true
+				break
+			}
+		}
+		if !exists {
+			t.Fatalf("one of {%s} should exists in the output, but not found",
+				strings.Join(possibleNames, ", "))
+		}
+	}
+}
+
+func checkKVMInfo(t *testing.T, scanner *bufio.Scanner) {
+	for scanner.Scan() {
+		line := scanner.Text()
+		if line == "" {
+			continue
+		}
+		if strings.HasPrefix(line, "-----") {
+			break
+		}
+		splitted := strings.Split(line, ":")
+		if len(splitted) != 2 {
+			t.Fatalf("the format of line \"%s\" is not correct", line)
+		}
+		key := strings.TrimSpace(splitted[0])
+		if key == "" {
+			t.Fatalf("empty key")
+		}
+		if key[0] != '/' {
+			continue
+		}
+
+		if !strings.HasPrefix(key, "/sys/module/kvm") {
+			t.Fatalf("the directory does not match /sys/module/kvm*")
+		}
+	}
+}
+
+func TestScanCPUInfo(t *testing.T) {
+	input := `A:	a
+B:	b
+
+C:	c1
+D:	d
+C:	c1
+D:	d
+C:	c2
+D:	d
+`
+
+	output := []struct {
+		key, val string
+	}{
+		{"A", "a"},
+		{"B", "b"},
+		{"C", "c1, c1, c2"},
+		{"D", "d"},
+	}
+	scanner := bufio.NewScanner(strings.NewReader(input))
+	buffer := new(bytes.Buffer)
+	scanCPUInfo(buffer, scanner)
+	result := bufio.NewScanner(buffer)
+
+	idx := 0
+	for result.Scan() {
+		line := result.Text()
+		splitted := strings.Split(line, ":")
+		if len(splitted) != 2 {
+			t.Fatalf("the format of line \"%s\" is not correct", line)
+		}
+		key := strings.TrimSpace(splitted[0])
+		val := strings.TrimSpace(splitted[1])
+		if idx >= len(output) {
+			t.Fatalf("additional line \"%s: %s\"", key, val)
+		}
+		expected := output[idx]
+		if key != expected.key || val != expected.val {
+			t.Fatalf("expected \"%s: %s\", got \"%s: %s\"",
+				expected.key, expected.val, key, val)
+		}
+		idx++
+	}
+	if idx < len(output) {
+		expected := output[idx]
+		t.Fatalf("expected \"%s: %s\", got end of output",
+			expected.key, expected.val)
+	}
+}