Files
gluetun/internal/provider/utils/pick.go
T
2026-05-04 03:29:35 +00:00

125 lines
3.3 KiB
Go

package utils
import (
"encoding/binary"
"errors"
"fmt"
"hash/fnv"
"net/netip"
"sync"
"github.com/qdm12/gluetun/internal/configuration/settings"
"github.com/qdm12/gluetun/internal/constants/vpn"
"github.com/qdm12/gluetun/internal/models"
)
// ConnectionPicker is a struct that holds the state of the connection pool cycler.
type ConnectionPicker struct {
mutex sync.Mutex
fingerprint uint64
nextIndex uint
}
func NewConnectionPicker() *ConnectionPicker {
return &ConnectionPicker{}
}
func (c *ConnectionPicker) pickConnection(connections []models.Connection,
) models.Connection {
fingerprint := fingerprintPool(connections)
c.mutex.Lock()
defer c.mutex.Unlock()
if c.fingerprint != fingerprint || c.nextIndex >= uint(len(connections)) {
c.fingerprint = fingerprint
c.nextIndex = 0
}
connection := connections[c.nextIndex]
c.nextIndex++
if c.nextIndex >= uint(len(connections)) {
c.nextIndex = 0
}
return connection
}
func fingerprintPool(connections []models.Connection) uint64 {
hasher := fnv.New64a()
for _, connection := range connections {
_, _ = hasher.Write([]byte(connection.Type))
_, _ = hasher.Write([]byte("|"))
_, _ = hasher.Write(connection.IP.AsSlice())
_, _ = hasher.Write([]byte("|"))
_, _ = hasher.Write(binary.BigEndian.AppendUint16(nil, connection.Port))
_, _ = hasher.Write([]byte("|"))
_, _ = hasher.Write([]byte(connection.Protocol))
_, _ = hasher.Write([]byte("|"))
_, _ = hasher.Write([]byte(connection.Hostname))
_, _ = hasher.Write([]byte("|"))
_, _ = hasher.Write([]byte(connection.PubKey))
_, _ = hasher.Write([]byte("|"))
_, _ = hasher.Write([]byte(connection.ServerName))
_, _ = hasher.Write([]byte("|"))
if connection.PortForward {
_, _ = hasher.Write([]byte("1"))
} else {
_, _ = hasher.Write([]byte("0"))
}
_, _ = hasher.Write([]byte("\n"))
}
return hasher.Sum64()
}
// pickConnection picks a connection from a pool of connections.
// If the VPN protocol is Wireguard and the target IP is set,
// it finds the connection corresponding to this target IP.
// Otherwise, it cycles through the pool of connections.
// and sets the target IP address as the IP if this one is set.
func pickConnection(connections []models.Connection,
selection settings.ServerSelection, picker *ConnectionPicker) (
connection models.Connection, err error,
) {
if len(connections) == 0 {
return connection, errors.New("no connection to pick from")
}
var targetIP netip.Addr
switch selection.VPN {
case vpn.OpenVPN:
targetIP = selection.OpenVPN.EndpointIP
case vpn.Wireguard, vpn.AmneziaWg:
targetIP = selection.Wireguard.EndpointIP
default:
panic("unknown VPN type: " + selection.VPN)
}
targetIPSet := targetIP.IsValid() && !targetIP.IsUnspecified()
if targetIPSet && selection.VPN == vpn.Wireguard {
// we need the right public key
return getTargetIPConnection(connections, targetIP)
}
connection = picker.pickConnection(connections)
if targetIPSet {
connection.IP = targetIP
}
return connection, nil
}
func getTargetIPConnection(connections []models.Connection,
targetIP netip.Addr,
) (connection models.Connection, err error) {
for _, connection := range connections {
if targetIP == connection.IP {
return connection, nil
}
}
return connection, fmt.Errorf("target IP address not found: in %d filtered connections",
len(connections))
}