safing-portmaster/firewall/api.go
2019-08-09 17:16:56 +02:00

110 lines
2.6 KiB
Go

package firewall
import (
"context"
"errors"
"fmt"
"net"
"net/http"
"strconv"
"strings"
"github.com/safing/portbase/utils"
"github.com/safing/portmaster/core/structure"
"github.com/safing/portbase/log"
"github.com/safing/portmaster/network/packet"
"github.com/safing/portmaster/process"
"github.com/safing/portbase/api"
)
var (
dataRoot *utils.DirStructure
apiPortSet bool
apiPort uint16
)
func prepAPIAuth() error {
dataRoot = structure.Root()
return api.SetAuthenticator(apiAuthenticator)
}
func startAPIAuth() {
var err error
_, apiPort, err = parseHostPort(apiListenAddress())
if err != nil {
log.Warningf("firewall: failed to parse API address for improved api auth mechanism: %s", err)
return
}
apiPortSet = true
log.Tracef("firewall: api port set to %d", apiPort)
}
func apiAuthenticator(s *http.Server, r *http.Request) (grantAccess bool, err error) {
if devMode() {
return true, nil
}
// get local IP/Port
localIP, localPort, err := parseHostPort(s.Addr)
if err != nil {
return false, fmt.Errorf("failed to get local IP/Port: %s", err)
}
// get remote IP/Port
remoteIP, remotePort, err := parseHostPort(r.RemoteAddr)
if err != nil {
return false, fmt.Errorf("failed to get remote IP/Port: %s", err)
}
var procsChecked []string
// get process
proc, err := process.GetProcessByEndpoints(r.Context(), remoteIP, remotePort, localIP, localPort, packet.TCP) // switch reverse/local to get remote process
if err != nil {
return false, fmt.Errorf("failed to get process: %s", err)
}
// go up up to two levels, if we don't match
for i := 0; i < 3; i++ {
// check if the requesting process is in database root / updates dir
if strings.HasPrefix(proc.Path, dataRoot.Path) {
return true, nil
}
// add checked process to list
procsChecked = append(procsChecked, proc.Path)
if i < 2 {
// get parent process
proc, err = process.GetOrFindProcess(context.Background(), proc.ParentPid)
if err != nil {
return false, fmt.Errorf("failed to get process: %s", err)
}
}
}
log.Debugf("firewall: denying api access to %s - also checked %s (trusted root is %s)", procsChecked[0], strings.Join(procsChecked[1:], " "), dataRoot.Path)
return false, nil
}
func parseHostPort(address string) (net.IP, uint16, error) {
ipString, portString, err := net.SplitHostPort(address)
if err != nil {
return nil, 0, err
}
ip := net.ParseIP(ipString)
if ip == nil {
return nil, 0, errors.New("invalid IP address")
}
port, err := strconv.ParseUint(portString, 10, 16)
if err != nil {
return nil, 0, err
}
return ip, uint16(port), nil
}