safing-portmaster/network/communication.go

365 lines
8.8 KiB
Go

// Copyright Safing ICS Technologies GmbH. Use of this source code is governed by the AGPL license that can be found in the LICENSE file.
package network
import (
"errors"
"fmt"
"net"
"sync"
"time"
"github.com/Safing/portbase/database/record"
"github.com/Safing/portmaster/intel"
"github.com/Safing/portmaster/network/netutils"
"github.com/Safing/portmaster/network/packet"
"github.com/Safing/portmaster/process"
"github.com/Safing/portmaster/profile"
)
// Communication describes a logical connection between a process and a domain.
type Communication struct {
record.Base
sync.Mutex
Domain string
Direction bool
Intel *intel.Intel
process *process.Process
Verdict Verdict
Reason string
Inspect bool
FirstLinkEstablished int64
LastLinkEstablished int64
LinkCount uint
profileUpdateVersion uint32
}
// Process returns the process that owns the connection.
func (comm *Communication) Process() *process.Process {
comm.Lock()
defer comm.Unlock()
return comm.process
}
// ResetVerdict resets the verdict to VerdictUndecided.
func (comm *Communication) ResetVerdict() {
comm.Lock()
defer comm.Unlock()
comm.Verdict = VerdictUndecided
comm.Reason = ""
}
// GetVerdict returns the current verdict.
func (comm *Communication) GetVerdict() Verdict {
comm.Lock()
defer comm.Unlock()
return comm.Verdict
}
// Accept accepts the communication and adds the given reason.
func (comm *Communication) Accept(reason string) {
comm.AddReason(reason)
comm.UpdateVerdict(VerdictAccept)
}
// Deny blocks or drops the communication depending on the connection direction and adds the given reason.
func (comm *Communication) Deny(reason string) {
if comm.Direction {
comm.Drop(reason)
} else {
comm.Block(reason)
}
}
// Block blocks the communication and adds the given reason.
func (comm *Communication) Block(reason string) {
comm.AddReason(reason)
comm.UpdateVerdict(VerdictBlock)
}
// Drop drops the communication and adds the given reason.
func (comm *Communication) Drop(reason string) {
comm.AddReason(reason)
comm.UpdateVerdict(VerdictDrop)
}
// UpdateVerdict sets a new verdict for this link, making sure it does not interfere with previous verdicts.
func (comm *Communication) UpdateVerdict(newVerdict Verdict) {
comm.Lock()
defer comm.Unlock()
if newVerdict > comm.Verdict {
comm.Verdict = newVerdict
go comm.Save()
}
}
// SetReason sets/replaces a human readable string as to why a certain verdict was set in regard to this communication.
func (comm *Communication) SetReason(reason string) {
if reason == "" {
return
}
comm.Lock()
defer comm.Unlock()
comm.Reason = reason
}
// AddReason adds a human readable string as to why a certain verdict was set in regard to this communication.
func (comm *Communication) AddReason(reason string) {
if reason == "" {
return
}
comm.Lock()
defer comm.Unlock()
if comm.Reason != "" {
comm.Reason += " | "
}
comm.Reason += reason
}
// NeedsReevaluation returns whether the decision on this communication should be re-evaluated.
func (comm *Communication) NeedsReevaluation() bool {
comm.Lock()
defer comm.Unlock()
oldVersion := comm.profileUpdateVersion
comm.profileUpdateVersion = profile.GetUpdateVersion()
if oldVersion == 0 {
return false
}
if oldVersion != comm.profileUpdateVersion {
return true
}
return false
}
// GetCommunicationByFirstPacket returns the matching communication from the internal storage.
func GetCommunicationByFirstPacket(pkt packet.Packet) (*Communication, error) {
// get Process
proc, direction, err := process.GetProcessByPacket(pkt)
if err != nil {
return nil, err
}
var domain string
// Incoming
if direction {
switch netutils.ClassifyIP(pkt.Info().Src) {
case netutils.HostLocal:
domain = IncomingHost
case netutils.LinkLocal, netutils.SiteLocal, netutils.LocalMulticast:
domain = IncomingLAN
case netutils.Global, netutils.GlobalMulticast:
domain = IncomingInternet
case netutils.Invalid:
domain = IncomingInvalid
}
communication, ok := GetCommunication(proc.Pid, domain)
if !ok {
communication = &Communication{
Domain: domain,
Direction: Inbound,
process: proc,
Inspect: true,
FirstLinkEstablished: time.Now().Unix(),
}
}
communication.process.AddCommunication()
return communication, nil
}
// get domain
ipinfo, err := intel.GetIPInfo(pkt.FmtRemoteIP())
// PeerToPeer
if err != nil {
// if no domain could be found, it must be a direct connection (ie. no DNS)
switch netutils.ClassifyIP(pkt.Info().Dst) {
case netutils.HostLocal:
domain = PeerHost
case netutils.LinkLocal, netutils.SiteLocal, netutils.LocalMulticast:
domain = PeerLAN
case netutils.Global, netutils.GlobalMulticast:
domain = PeerInternet
case netutils.Invalid:
domain = PeerInvalid
}
communication, ok := GetCommunication(proc.Pid, domain)
if !ok {
communication = &Communication{
Domain: domain,
Direction: Outbound,
process: proc,
Inspect: true,
FirstLinkEstablished: time.Now().Unix(),
}
}
communication.process.AddCommunication()
return communication, nil
}
// To Domain
// FIXME: how to handle multiple possible domains?
communication, ok := GetCommunication(proc.Pid, ipinfo.Domains[0])
if !ok {
communication = &Communication{
Domain: ipinfo.Domains[0],
Direction: Outbound,
process: proc,
Inspect: true,
FirstLinkEstablished: time.Now().Unix(),
}
}
communication.process.AddCommunication()
return communication, nil
}
// var localhost = net.IPv4(127, 0, 0, 1)
var (
dnsAddress = net.IPv4(127, 0, 0, 1)
dnsPort uint16 = 53
)
// GetCommunicationByDNSRequest returns the matching communication from the internal storage.
func GetCommunicationByDNSRequest(ip net.IP, port uint16, fqdn string) (*Communication, error) {
// get Process
proc, err := process.GetProcessByEndpoints(ip, port, dnsAddress, dnsPort, packet.UDP)
if err != nil {
return nil, err
}
communication, ok := GetCommunication(proc.Pid, fqdn)
if !ok {
communication = &Communication{
Domain: fqdn,
process: proc,
Inspect: true,
}
communication.process.AddCommunication()
communication.Save()
}
return communication, nil
}
// GetCommunication fetches a connection object from the internal storage.
func GetCommunication(pid int, domain string) (comm *Communication, ok bool) {
commsLock.RLock()
defer commsLock.RUnlock()
comm, ok = comms[fmt.Sprintf("%d/%s", pid, domain)]
return
}
func (comm *Communication) makeKey() string {
return fmt.Sprintf("%d/%s", comm.process.Pid, comm.Domain)
}
// Save saves the connection object in the storage and propagates the change.
func (comm *Communication) Save() error {
comm.Lock()
defer comm.Unlock()
if comm.process == nil {
return errors.New("cannot save connection without process")
}
if !comm.KeyIsSet() {
comm.SetKey(fmt.Sprintf("network:tree/%d/%s", comm.process.Pid, comm.Domain))
comm.CreateMeta()
}
key := comm.makeKey()
commsLock.RLock()
_, ok := comms[key]
commsLock.RUnlock()
if !ok {
commsLock.Lock()
comms[key] = comm
commsLock.Unlock()
}
go dbController.PushUpdate(comm)
return nil
}
// Delete deletes a connection from the storage and propagates the change.
func (comm *Communication) Delete() {
comm.Lock()
defer comm.Unlock()
commsLock.Lock()
delete(comms, comm.makeKey())
commsLock.Unlock()
comm.Meta().Delete()
go dbController.PushUpdate(comm)
comm.process.RemoveCommunication()
go comm.process.Save()
}
// AddLink applies the Communication to the Link and increases sets counter and timestamps.
func (comm *Communication) AddLink(link *Link) {
link.Lock()
link.comm = comm
link.Verdict = comm.Verdict
link.Inspect = comm.Inspect
link.Unlock()
link.Save()
comm.Lock()
comm.LinkCount++
comm.LastLinkEstablished = time.Now().Unix()
if comm.FirstLinkEstablished == 0 {
comm.FirstLinkEstablished = comm.LastLinkEstablished
}
comm.Unlock()
comm.Save()
}
// RemoveLink lowers the link counter by one.
func (comm *Communication) RemoveLink() {
comm.Lock()
defer comm.Unlock()
if comm.LinkCount > 0 {
comm.LinkCount--
}
}
// String returns a string representation of Communication.
func (comm *Communication) String() string {
comm.Lock()
defer comm.Unlock()
switch comm.Domain {
case IncomingHost, IncomingLAN, IncomingInternet, IncomingInvalid:
if comm.process == nil {
return "? <- *"
}
return fmt.Sprintf("%s <- *", comm.process.String())
case PeerHost, PeerLAN, PeerInternet, PeerInvalid:
if comm.process == nil {
return "? -> *"
}
return fmt.Sprintf("%s -> *", comm.process.String())
default:
if comm.process == nil {
return fmt.Sprintf("? -> %s", comm.Domain)
}
return fmt.Sprintf("%s -> %s", comm.process.String(), comm.Domain)
}
}