1 files changed, 153 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/modules/openvpn/client/client.go b/src/go/collectors/go.d.plugin/modules/openvpn/client/client.go
new file mode 100644
index 000000000..ddbfdeafb
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/modules/openvpn/client/client.go
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package client
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/socket"
+)
+
+var (
+	reLoadStats = regexp.MustCompile(`^SUCCESS: nclients=([0-9]+),bytesin=([0-9]+),bytesout=([0-9]+)`)
+	reVersion   = regexp.MustCompile(`^OpenVPN Version: OpenVPN ([0-9]+)\.([0-9]+)\.([0-9]+) .+Management Version: ([0-9])`)
+)
+
+const maxLinesToRead = 500
+
+// New creates new OpenVPN client.
+func New(config socket.Config) *Client {
+	return &Client{Client: socket.New(config)}
+}
+
+// Client represents OpenVPN client.
+type Client struct {
+	socket.Client
+}
+
+// Users Users.
+func (c *Client) Users() (Users, error) {
+	lines, err := c.get(commandStatus3, readUntilEND)
+	if err != nil {
+		return nil, err
+	}
+	return decodeUsers(lines)
+}
+
+// LoadStats LoadStats.
+func (c *Client) LoadStats() (*LoadStats, error) {
+	lines, err := c.get(commandLoadStats, readOneLine)
+	if err != nil {
+		return nil, err
+	}
+	return decodeLoadStats(lines)
+}
+
+// Version Version.
+func (c *Client) Version() (*Version, error) {
+	lines, err := c.get(commandVersion, readUntilEND)
+	if err != nil {
+		return nil, err
+	}
+	return decodeVersion(lines)
+}
+
+func (c *Client) get(command string, stopRead stopReadFunc) (output []string, err error) {
+	var num int
+	var maxLinesErr error
+	err = c.Command(command, func(bytes []byte) bool {
+		line := string(bytes)
+		num++
+		if num > maxLinesToRead {
+			maxLinesErr = fmt.Errorf("read line limit exceeded (%d)", maxLinesToRead)
+			return false
+		}
+
+		// skip real-time messages
+		if strings.HasPrefix(line, ">") {
+			return true
+		}
+
+		line = strings.Trim(line, "\r\n ")
+		output = append(output, line)
+		if stopRead != nil && stopRead(line) {
+			return false
+		}
+		return true
+	})
+	if maxLinesErr != nil {
+		return nil, maxLinesErr
+	}
+	return output, err
+}
+
+type stopReadFunc func(string) bool
+
+func readOneLine(_ string) bool { return true }
+
+func readUntilEND(s string) bool { return strings.HasSuffix(s, "END") }
+
+func decodeLoadStats(src []string) (*LoadStats, error) {
+	m := reLoadStats.FindStringSubmatch(strings.Join(src, " "))
+	if len(m) == 0 {
+		return nil, fmt.Errorf("parse failed : %v", src)
+	}
+	return &LoadStats{
+		NumOfClients: mustParseInt(m[1]),
+		BytesIn:      mustParseInt(m[2]),
+		BytesOut:     mustParseInt(m[3]),
+	}, nil
+}
+
+func decodeVersion(src []string) (*Version, error) {
+	m := reVersion.FindStringSubmatch(strings.Join(src, " "))
+	if len(m) == 0 {
+		return nil, fmt.Errorf("parse failed : %v", src)
+	}
+	return &Version{
+		Major:      mustParseInt(m[1]),
+		Minor:      mustParseInt(m[2]),
+		Patch:      mustParseInt(m[3]),
+		Management: mustParseInt(m[4]),
+	}, nil
+}
+
+// works only for `status 3\n`
+func decodeUsers(src []string) (Users, error) {
+	var users Users
+
+	// [CLIENT_LIST common_name 178.66.34.194:54200 10.9.0.5 9319 8978 Thu May 9 05:01:44 2019 1557345704 username]
+	for _, v := range src {
+		if !strings.HasPrefix(v, "CLIENT_LIST") {
+			continue
+		}
+		parts := strings.Fields(v)
+		// Right after the connection there are no virtual ip, and both common name and username UNDEF
+		// CLIENT_LIST	UNDEF	178.70.95.93:39324		1411	3474	Fri May 10 07:41:54 2019	1557441714	UNDEF
+		if len(parts) != 13 {
+			continue
+		}
+		u := User{
+			CommonName:     parts[1],
+			RealAddress:    parts[2],
+			VirtualAddress: parts[3],
+			BytesReceived:  mustParseInt(parts[4]),
+			BytesSent:      mustParseInt(parts[5]),
+			ConnectedSince: mustParseInt(parts[11]),
+			Username:       parts[12],
+		}
+		users = append(users, u)
+	}
+	return users, nil
+}
+
+func mustParseInt(str string) int64 {
+	v, err := strconv.ParseInt(str, 10, 64)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}