netmaker/logic/gateway.go
2022-08-07 20:28:10 -07:00

354 lines
13 KiB
Go

package logic
import (
"encoding/json"
"errors"
"fmt"
"strings"
"time"
"github.com/gravitl/netmaker/database"
"github.com/gravitl/netmaker/logger"
"github.com/gravitl/netmaker/models"
)
// CreateEgressGateway - creates an egress gateway
func CreateEgressGateway(gateway models.EgressGatewayRequest) (models.Node, error) {
node, err := GetNodeByID(gateway.NodeID)
if err != nil {
return models.Node{}, err
}
if node.OS != "linux" && node.OS != "freebsd" { // add in darwin later
return models.Node{}, errors.New(node.OS + " is unsupported for egress gateways")
}
if gateway.NatEnabled == "" {
gateway.NatEnabled = "yes"
}
err = ValidateEgressGateway(gateway)
if err != nil {
return models.Node{}, err
}
node.IsEgressGateway = "yes"
node.EgressGatewayRanges = gateway.Ranges
node.EgressGatewayNatEnabled = gateway.NatEnabled
node.EgressGatewayRequest = gateway // store entire request for use when preserving the egress gateway
postUpCmd := ""
postDownCmd := ""
logger.Log(3, "creating egress gateway firewall in use is '", node.FirewallInUse, "'")
if node.OS == "linux" {
switch node.FirewallInUse {
case models.FIREWALL_NFTABLES:
// nftables only supported on Linux
// assumes chains eg FORWARD and POSTROUTING already exist
logger.Log(3, "creating egress gateway nftables is present")
// down commands don't remove as removal of the rules leaves an empty chain while
// removing the chain with rules in it would remove all rules in that section (not safe
// if there are remaining rules on the host that need to stay). In practice the chain is removed
// when non-empty even though the removal of a non-empty chain should not be possible per nftables wiki.
postUpCmd, postDownCmd = firewallNFTCommandsCreateEgress(node.Interface, gateway.Interface, node.EgressGatewayNatEnabled)
default: // iptables assumed
logger.Log(3, "creating egress gateway nftables is not present")
postUpCmd, postDownCmd = firewallIPTablesCommandsCreateEgress(node.Interface, gateway.Interface, node.EgressGatewayNatEnabled)
}
}
if node.OS == "freebsd" {
postUpCmd = "kldload ipfw ipfw_nat ; "
postUpCmd += "ipfw disable one_pass ; "
postUpCmd += "ipfw nat 1 config if " + gateway.Interface + " same_ports unreg_only reset ; "
postUpCmd += "ipfw add 64000 reass all from any to any in ; "
postUpCmd += "ipfw add 64000 nat 1 ip from any to any in via " + gateway.Interface + " ; "
postUpCmd += "ipfw add 64000 check-state ; "
postUpCmd += "ipfw add 64000 nat 1 ip from any to any out via " + gateway.Interface + " ; "
postUpCmd += "ipfw add 65534 allow ip from any to any ; "
postDownCmd = "ipfw delete 64000 ; "
postDownCmd += "ipfw delete 65534 ; "
postDownCmd += "kldunload ipfw_nat ipfw"
}
if gateway.PostUp != "" {
postUpCmd = gateway.PostUp
}
if gateway.PostDown != "" {
postDownCmd = gateway.PostDown
}
if node.PostUp != "" {
if !strings.Contains(node.PostUp, postUpCmd) {
postUpCmd = node.PostUp + "; " + postUpCmd
}
}
if node.PostDown != "" {
if !strings.Contains(node.PostDown, postDownCmd) {
postDownCmd = node.PostDown + "; " + postDownCmd
}
}
node.PostUp = postUpCmd
node.PostDown = postDownCmd
node.SetLastModified()
nodeData, err := json.Marshal(&node)
if err != nil {
return node, err
}
if err = database.Insert(node.ID, string(nodeData), database.NODES_TABLE_NAME); err != nil {
return models.Node{}, err
}
if err = NetworkNodesUpdatePullChanges(node.Network); err != nil {
return models.Node{}, err
}
return node, nil
}
// ValidateEgressGateway - validates the egress gateway model
func ValidateEgressGateway(gateway models.EgressGatewayRequest) error {
var err error
empty := len(gateway.Ranges) == 0
if empty {
err = errors.New("IP Ranges Cannot Be Empty")
}
empty = gateway.Interface == ""
if empty {
err = errors.New("interface cannot be empty")
}
return err
}
// DeleteEgressGateway - deletes egress from node
func DeleteEgressGateway(network, nodeid string) (models.Node, error) {
node, err := GetNodeByID(nodeid)
if err != nil {
return models.Node{}, err
}
node.IsEgressGateway = "no"
node.EgressGatewayRanges = []string{}
node.EgressGatewayRequest = models.EgressGatewayRequest{} // remove preserved request as the egress gateway is gone
// needed in case we don't preserve a gateway (i.e., no ingress to preserve)
node.PostUp = ""
node.PostDown = ""
logger.Log(3, "deleting egress gateway firewall in use is '", node.FirewallInUse, "'")
if node.IsIngressGateway == "yes" { // check if node is still an ingress gateway before completely deleting postdown/up rules
// still have an ingress gateway so preserve it
if node.OS == "linux" {
switch node.FirewallInUse {
case models.FIREWALL_NFTABLES:
// nftables only supported on Linux
// assumes chains eg FORWARD and POSTROUTING already exist
logger.Log(3, "deleting egress gateway nftables is present")
node.PostUp, node.PostDown = firewallNFTCommandsCreateIngress(node.Interface)
default:
logger.Log(3, "deleting egress gateway nftables is not present")
node.PostUp, node.PostDown = firewallIPTablesCommandsCreateIngress(node.Interface)
}
}
// no need to preserve ingress gateway on FreeBSD as ingress is not supported on that OS
}
node.SetLastModified()
data, err := json.Marshal(&node)
if err != nil {
return models.Node{}, err
}
if err = database.Insert(node.ID, string(data), database.NODES_TABLE_NAME); err != nil {
return models.Node{}, err
}
if err = NetworkNodesUpdatePullChanges(network); err != nil {
return models.Node{}, err
}
return node, nil
}
// CreateIngressGateway - creates an ingress gateway
func CreateIngressGateway(netid string, nodeid string) (models.Node, error) {
var postUpCmd, postDownCmd string
node, err := GetNodeByID(nodeid)
if node.OS != "linux" { // add in darwin later
return models.Node{}, errors.New(node.OS + " is unsupported for ingress gateways")
}
if err != nil {
return models.Node{}, err
}
network, err := GetParentNetwork(netid)
if err != nil {
return models.Node{}, err
}
node.IsIngressGateway = "yes"
node.IngressGatewayRange = network.AddressRange
logger.Log(3, "creating ingress gateway firewall in use is '", node.FirewallInUse, "'")
switch node.FirewallInUse {
case models.FIREWALL_NFTABLES:
// nftables only supported on Linux
// assumes chains eg FORWARD and POSTROUTING already exist
logger.Log(3, "creating ingress gateway nftables is present")
postUpCmd, postDownCmd = firewallNFTCommandsCreateIngress(node.Interface)
default:
logger.Log(3, "creating ingress gateway using nftables is not present")
postUpCmd, postDownCmd = firewallIPTablesCommandsCreateIngress(node.Interface)
}
if node.PostUp != "" {
if !strings.Contains(node.PostUp, postUpCmd) {
postUpCmd = node.PostUp + "; " + postUpCmd
}
}
if node.PostDown != "" {
if !strings.Contains(node.PostDown, postDownCmd) {
postDownCmd = node.PostDown + "; " + postDownCmd
}
}
node.SetLastModified()
node.PostUp = postUpCmd
node.PostDown = postDownCmd
node.UDPHolePunch = "no"
data, err := json.Marshal(&node)
if err != nil {
return models.Node{}, err
}
err = database.Insert(node.ID, string(data), database.NODES_TABLE_NAME)
if err != nil {
return models.Node{}, err
}
err = SetNetworkNodesLastModified(netid)
return node, err
}
// DeleteIngressGateway - deletes an ingress gateway
func DeleteIngressGateway(networkName string, nodeid string) (models.Node, error) {
node, err := GetNodeByID(nodeid)
if err != nil {
return models.Node{}, err
}
network, err := GetParentNetwork(networkName)
if err != nil {
return models.Node{}, err
}
// delete ext clients belonging to ingress gateway
if err = DeleteGatewayExtClients(node.ID, networkName); err != nil {
return models.Node{}, err
}
logger.Log(3, "deleting ingress gateway")
node.UDPHolePunch = network.DefaultUDPHolePunch
node.LastModified = time.Now().Unix()
node.IsIngressGateway = "no"
node.IngressGatewayRange = ""
// default to removing postup and postdown
node.PostUp = ""
node.PostDown = ""
logger.Log(3, "deleting ingress gateway firewall in use is '", node.FirewallInUse, "' and isEgressGateway is", node.IsEgressGateway)
if node.EgressGatewayRequest.NodeID != "" {
_, err := CreateEgressGateway(node.EgressGatewayRequest)
if err != nil {
logger.Log(0, fmt.Sprintf("failed to create egress gateway on node [%s] on network [%s]: %v",
node.EgressGatewayRequest.NodeID, node.EgressGatewayRequest.NetID, err))
}
}
data, err := json.Marshal(&node)
if err != nil {
return models.Node{}, err
}
err = database.Insert(node.ID, string(data), database.NODES_TABLE_NAME)
if err != nil {
return models.Node{}, err
}
err = SetNetworkNodesLastModified(networkName)
return node, err
}
// DeleteGatewayExtClients - deletes ext clients based on gateway (mac) of ingress node and network
func DeleteGatewayExtClients(gatewayID string, networkName string) error {
currentExtClients, err := GetNetworkExtClients(networkName)
if err != nil && !database.IsEmptyRecord(err) {
return err
}
for _, extClient := range currentExtClients {
if extClient.IngressGatewayID == gatewayID {
if err = DeleteExtClient(networkName, extClient.ClientID); err != nil {
logger.Log(1, "failed to remove ext client", extClient.ClientID)
continue
}
}
}
return nil
}
// firewallNFTCommandsCreateIngress - used to centralize firewall command maintenance for creating an ingress gateway using the nftables firewall.
func firewallNFTCommandsCreateIngress(networkInterface string) (string, string) {
postUp := "nft add table ip filter ; "
postUp += "nft add chain ip filter FORWARD ; "
postUp += "nft add rule ip filter FORWARD iifname " + networkInterface + " counter accept ; "
postUp += "nft add rule ip filter FORWARD oifname " + networkInterface + " counter accept ; "
postUp += "nft add table nat ; "
postUp += "nft add chain nat POSTROUTING ; "
postUp += "nft add rule ip nat POSTROUTING oifname " + networkInterface + " counter masquerade"
// doesn't remove potentially empty tables or chains
postDown := "nft delete rule ip filter FORWARD iifname " + networkInterface + " counter accept ; "
postDown += "nft delete rule ip filter FORWARD oifname " + networkInterface + " counter accept ; "
postDown += "nft delete rule ip nat POSTROUTING oifname " + networkInterface + " counter masquerade"
return postUp, postDown
}
// firewallNFTCommandsCreateEgress - used to centralize firewall command maintenance for creating an egress gateway using the nftables firewall.
func firewallNFTCommandsCreateEgress(networkInterface string, gatewayInterface string, egressNatEnabled string) (string, string) {
postUp := "nft add table ip filter ; "
postUp += "nft add chain ip filter FORWARD ; "
postUp += "nft add rule ip filter FORWARD iifname " + networkInterface + " counter accept ; "
postUp += "nft add rule ip filter FORWARD oifname " + networkInterface + " counter accept ; "
postDown := "nft delete rule ip filter FORWARD iifname " + networkInterface + " counter accept ; "
postDown += "nft delete rule ip filter FORWARD oifname " + networkInterface + " counter accept ; "
if egressNatEnabled == "yes" {
postUp += "nft add table nat ; "
postUp += "nft add chain nat POSTROUTING ; "
postUp += "nft add rule ip nat POSTROUTING oifname " + gatewayInterface + " counter masquerade ;"
postDown += "nft delete rule ip nat POSTROUTING oifname " + gatewayInterface + " counter masquerade ;"
}
return postUp, postDown
}
// firewallIPTablesCommandsCreateIngress - used to centralize firewall command maintenance for creating an ingress gateway using the iptables firewall.
func firewallIPTablesCommandsCreateIngress(networkInterface string) (string, string) {
postUp := "iptables -A FORWARD -i " + networkInterface + " -j ACCEPT ; "
postUp += "iptables -A FORWARD -o " + networkInterface + " -j ACCEPT ; "
postUp += "iptables -t nat -A POSTROUTING -o " + networkInterface + " -j MASQUERADE"
// doesn't remove potentially empty tables or chains
postDown := "iptables -D FORWARD -i " + networkInterface + " -j ACCEPT ; "
postDown += "iptables -D FORWARD -o " + networkInterface + " -j ACCEPT ; "
postDown += "iptables -t nat -D POSTROUTING -o " + networkInterface + " -j MASQUERADE"
return postUp, postDown
}
// firewallIPTablesCommandsCreateEgress - used to centralize firewall command maintenance for creating an egress gateway using the iptables firewall.
func firewallIPTablesCommandsCreateEgress(networkInterface string, gatewayInterface string, egressNatEnabled string) (string, string) {
postUp := "iptables -A FORWARD -i " + networkInterface + " -j ACCEPT; "
postUp += "iptables -A FORWARD -o " + networkInterface + " -j ACCEPT"
postDown := "iptables -D FORWARD -i " + networkInterface + " -j ACCEPT; "
postDown += "iptables -D FORWARD -o " + networkInterface + " -j ACCEPT"
if egressNatEnabled == "yes" {
postUp += "; iptables -t nat -A POSTROUTING -o " + gatewayInterface + " -j MASQUERADE"
postDown += "; iptables -t nat -D POSTROUTING -o " + gatewayInterface + " -j MASQUERADE"
}
return postUp, postDown
}