Files
gluetun/internal/routing/mutate.go
2021-08-23 21:12:28 +00:00

127 lines
3.5 KiB
Go

package routing
import (
"bytes"
"errors"
"fmt"
"net"
"strconv"
"github.com/qdm12/gluetun/internal/netlink"
)
var (
ErrRouteReplace = errors.New("cannot replace route")
ErrRouteDelete = errors.New("cannot delete route")
ErrRuleAdd = errors.New("cannot add routing rule")
ErrRuleDel = errors.New("cannot delete routing rule")
)
func (r *Routing) addRouteVia(destination net.IPNet, gateway net.IP, iface string, table int) error {
destinationStr := destination.String()
r.logger.Info("adding route for " + destinationStr)
r.logger.Debug("ip route replace " + destinationStr +
" via " + gateway.String() +
" dev " + iface +
" table " + strconv.Itoa(table))
link, err := r.netLinker.LinkByName(iface)
if err != nil {
return fmt.Errorf("%w: interface %s: %s", ErrLinkByName, iface, err)
}
route := netlink.Route{
Dst: &destination,
Gw: gateway,
LinkIndex: link.Attrs().Index,
Table: table,
}
if err := r.netLinker.RouteReplace(&route); err != nil {
return fmt.Errorf("%w: for subnet %s at interface %s: %s",
ErrRouteReplace, destinationStr, iface, err)
}
return nil
}
func (r *Routing) deleteRouteVia(destination net.IPNet, gateway net.IP, iface string, table int) (err error) {
destinationStr := destination.String()
r.logger.Info("deleting route for " + destinationStr)
r.logger.Debug("ip route delete " + destinationStr +
" via " + gateway.String() +
" dev " + iface +
" table " + strconv.Itoa(table))
link, err := r.netLinker.LinkByName(iface)
if err != nil {
return fmt.Errorf("%w: for interface %s: %s", ErrLinkByName, iface, err)
}
route := netlink.Route{
Dst: &destination,
Gw: gateway,
LinkIndex: link.Attrs().Index,
Table: table,
}
if err := r.netLinker.RouteDel(&route); err != nil {
return fmt.Errorf("%w: for subnet %s at interface %s: %s",
ErrRouteDelete, destinationStr, iface, err)
}
return nil
}
func (r *Routing) addIPRule(src net.IP, table, priority int) error {
r.logger.Debug("ip rule add from " + src.String() +
" lookup " + strconv.Itoa(table) +
" pref " + strconv.Itoa(priority))
rule := netlink.NewRule()
rule.Src = netlink.NewIPNet(src)
rule.Priority = priority
rule.Table = table
rules, err := r.netLinker.RuleList(netlink.FAMILY_ALL)
if err != nil {
return fmt.Errorf("%w: %s", ErrRulesList, err)
}
for _, existingRule := range rules {
if existingRule.Src != nil &&
existingRule.Src.IP.Equal(rule.Src.IP) &&
bytes.Equal(existingRule.Src.Mask, rule.Src.Mask) &&
existingRule.Priority == rule.Priority &&
existingRule.Table == rule.Table {
return nil // already exists
}
}
if err := r.netLinker.RuleAdd(rule); err != nil {
return fmt.Errorf("%w: for rule %q: %s", ErrRuleAdd, rule, err)
}
return nil
}
func (r *Routing) deleteIPRule(src net.IP, table, priority int) error {
r.logger.Debug("ip rule del from " + src.String() +
" lookup " + strconv.Itoa(table) +
" pref " + strconv.Itoa(priority))
rule := netlink.NewRule()
rule.Src = netlink.NewIPNet(src)
rule.Priority = priority
rule.Table = table
rules, err := r.netLinker.RuleList(netlink.FAMILY_ALL)
if err != nil {
return fmt.Errorf("%w: %s", ErrRulesList, err)
}
for _, existingRule := range rules {
if existingRule.Src != nil &&
existingRule.Src.IP.Equal(rule.Src.IP) &&
bytes.Equal(existingRule.Src.Mask, rule.Src.Mask) &&
existingRule.Priority == rule.Priority &&
existingRule.Table == rule.Table {
if err := r.netLinker.RuleDel(rule); err != nil {
return fmt.Errorf("%w: for rule %q: %s", ErrRuleDel, rule, err)
}
}
}
return nil
}