webnet/tailscale
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

feature/conn25: Update ConnectorTransitIPRequest handling (#18979)

Browse Source 
Changed the mapping to store the transit IPs to be indexed by
peer IP rather than NodeID because the data path only has access
to the peer's IP. This change means that IPv4 transit IPs need to
be indexed by the peer's IPv4 address, and IPv6 transit IPs need to
be indexed by the peer's IPv6 address. It is an error if the peer
does not have an address of the same family as the transit IP.
It is also an error if the transit and destination IP families do
not match.

Added a check to ensure that the TransitIPRequest.App matches a
configured app on the connector.

Added additional TransitIPResponse codes to identify the new errors
and change the exsting use of the Other code to use it's own
specific code.

Added logging for the error cases, since they generally indicate that
a peer has constructed a bad request or that there is a config
mismatch between the peer and the local netmap.

Added a test framework for handleConnectorTransitIPRequest and moved
the existing tests into the framework and added new tests.

Fixes tailscale/corp#37143

Signed-off-by: George Jones <george@tailscale.com>
This commit is contained in:
George Jones
2026-03-13 13:26:08 -04:00
committed by GitHub
parent 621f71981c
commit 660a4608d2
2 changed files with 414 additions and 182 deletions
Download Patch File Download Diff File Expand all files Collapse all files
feature/conn25/conn25.go
+82 -17
View File
@@ -26,6 +26,7 @@ import (
"tailscale.com/ipn/ipnext"
"tailscale.com/ipn/ipnlocal"
"tailscale.com/net/dns"
"tailscale.com/net/tsaddr"
"tailscale.com/tailcfg"
"tailscale.com/types/appctype"
"tailscale.com/types/logger"
@@ -131,7 +132,7 @@ func (e *extension) handleConnectorTransitIP(h ipnlocal.PeerAPIHandler, w http.R
http.Error(w, "Error decoding JSON", http.StatusBadRequest)
return
}
resp := e.conn25.handleConnectorTransitIPRequest(h.Peer().ID(), req)
resp := e.conn25.handleConnectorTransitIPRequest(h.Peer(), req)
bs, err := json.Marshal(resp)
if err != nil {
http.Error(w, "Error encoding JSON", http.StatusInternalServerError)
@@ -248,47 +249,94 @@ func (c *Conn25) mapDNSResponse(buf []byte) []byte {
}
const dupeTransitIPMessage = "Duplicate transit address in ConnectorTransitIPRequest"
const noMatchingPeerIPFamilyMessage = "No peer IP found with matching IP family"
const addrFamilyMismatchMessage = "Transit and Destination addresses must have matching IP family"
const unknownAppNameMessage = "The App name in the request does not match a configured App"
// handleConnectorTransitIPRequest creates a ConnectorTransitIPResponse in response
// to a ConnectorTransitIPRequest. It updates the connectors mapping of
// TransitIP->DestinationIP per peer (using the Peer's IP that matches the address
// family of the transitIP). If a peer has stored this mapping in the connector,
// Conn25 will route traffic to TransitIPs to DestinationIPs for that peer.
func (c *Conn25) handleConnectorTransitIPRequest(n tailcfg.NodeView, ctipr ConnectorTransitIPRequest) ConnectorTransitIPResponse {
var peerIPv4, peerIPv6 netip.Addr
for _, ip := range n.Addresses().All() {
if !ip.IsSingleIP() || !tsaddr.IsTailscaleIP(ip.Addr()) {
continue
}
if ip.Addr().Is4() && !peerIPv4.IsValid() {
peerIPv4 = ip.Addr()
} else if ip.Addr().Is6() && !peerIPv6.IsValid() {
peerIPv6 = ip.Addr()
}
}
// handleConnectorTransitIPRequest creates a ConnectorTransitIPResponse in response to a ConnectorTransitIPRequest.
// It updates the connectors mapping of TransitIP->DestinationIP per peer (tailcfg.NodeID).
// If a peer has stored this mapping in the connector Conn25 will route traffic to TransitIPs to DestinationIPs for that peer.
func (c *Conn25) handleConnectorTransitIPRequest(nid tailcfg.NodeID, ctipr ConnectorTransitIPRequest) ConnectorTransitIPResponse {
resp := ConnectorTransitIPResponse{}
seen := map[netip.Addr]bool{}
for _, each := range ctipr.TransitIPs {
if seen[each.TransitIP] {
resp.TransitIPs = append(resp.TransitIPs, TransitIPResponse{
Code: OtherFailure,
Code: DuplicateTransitIP,
Message: dupeTransitIPMessage,
})
c.connector.logf("[Unexpected] peer attempt to map a transit IP reused a transitIP: node: %s, IP: %v",
n.StableID(), each.TransitIP)
continue
}
tipresp := c.connector.handleTransitIPRequest(nid, each)
tipresp := c.connector.handleTransitIPRequest(n, peerIPv4, peerIPv6, each)
seen[each.TransitIP] = true
resp.TransitIPs = append(resp.TransitIPs, tipresp)
}
return resp
}
func (s *connector) handleTransitIPRequest(nid tailcfg.NodeID, tipr TransitIPRequest) TransitIPResponse {
func (s *connector) handleTransitIPRequest(n tailcfg.NodeView, peerV4 netip.Addr, peerV6 netip.Addr, tipr TransitIPRequest) TransitIPResponse {
if tipr.TransitIP.Is4() != tipr.DestinationIP.Is4() {
s.logf("[Unexpected] peer attempt to map a transit IP to dest IP did not have matching families: node: %s, tIPv4: %v dIPv4: %v",
n.StableID(), tipr.TransitIP.Is4(), tipr.DestinationIP.Is4())
return TransitIPResponse{Code: AddrFamilyMismatch, Message: addrFamilyMismatchMessage}
}
// Datapath lookups only have access to the peer IP, and that will match the family
// of the transit IP, so we need to store v4 and v6 mappings separately.
var peerAddr netip.Addr
if tipr.TransitIP.Is4() {
peerAddr = peerV4
} else {
peerAddr = peerV6
}
// If we couldn't find a matching family, return an error.
if !peerAddr.IsValid() {
s.logf("[Unexpected] peer attempt to map a transit IP did not have a matching address family: node: %s, IPv4: %v",
n.StableID(), tipr.TransitIP.Is4())
return TransitIPResponse{NoMatchingPeerIPFamily, noMatchingPeerIPFamilyMessage}
}
s.mu.Lock()
defer s.mu.Unlock()
if s.transitIPs == nil {
s.transitIPs = make(map[tailcfg.NodeID]map[netip.Addr]appAddr)
if _, ok := s.config.appsByName[tipr.App]; !ok {
s.logf("[Unexpected] peer attempt to map a transit IP referenced unknown app: node: %s, app: %q",
n.StableID(), tipr.App)
return TransitIPResponse{Code: UnknownAppName, Message: unknownAppNameMessage}
}
peerMap, ok := s.transitIPs[nid]
if s.transitIPs == nil {
s.transitIPs = make(map[netip.Addr]map[netip.Addr]appAddr)
}
peerMap, ok := s.transitIPs[peerAddr]
if !ok {
peerMap = make(map[netip.Addr]appAddr)
s.transitIPs[nid] = peerMap
s.transitIPs[peerAddr] = peerMap
}
peerMap[tipr.TransitIP] = appAddr{addr: tipr.DestinationIP, app: tipr.App}
return TransitIPResponse{}
}
func (s *connector) transitIPTarget(nid tailcfg.NodeID, tip netip.Addr) netip.Addr {
func (s *connector) transitIPTarget(peerIP, tip netip.Addr) netip.Addr {
s.mu.Lock()
defer s.mu.Unlock()
return s.transitIPs[nid][tip].addr
return s.transitIPs[peerIP][tip].addr
}
// TransitIPRequest details a single TransitIP allocation request from a client to a
@@ -322,8 +370,24 @@ const (
OK TransitIPResponseCode = 0
// OtherFailure indicates that the mapping failed for a reason that does not have
// another relevant [TransitIPResponsecode].
// another relevant [TransitIPResponseCode].
OtherFailure TransitIPResponseCode = 1
// DuplicateTransitIP indicates that the same transit address appeared more than
// once in a [ConnectorTransitIPRequest].
DuplicateTransitIP TransitIPResponseCode = 2
// NoMatchingPeerIPFamily indicates that the peer did not have an associated
// IP with the same family as transit IP being registered.
NoMatchingPeerIPFamily = 3
// AddrFamilyMismatch indicates that the transit IP and destination IP addresses
// do not belong to the same IP family.
AddrFamilyMismatch = 4
// UnknownAppName indicates that the connector is not configured to handle requests
// for the App name that was specified in the request.
UnknownAppName = 5
)
// TransitIPResponse is the response to a TransitIPRequest
@@ -651,8 +715,9 @@ type connector struct {
logf logger.Logf
mu sync.Mutex // protects the fields below
// transitIPs is a map of connector client peer NodeID -> client transitIPs that we update as connector client peers instruct us to, and then use to route traffic to its destination on behalf of connector clients.
transitIPs map[tailcfg.NodeID]map[netip.Addr]appAddr
// transitIPs is a map of connector client peer IP -> client transitIPs that we update as connector client peers instruct us to, and then use to route traffic to its destination on behalf of connector clients.
// Note that each peer could potentially have two maps: one for its IPv4 address, and one for its IPv6 address. The transit IPs map for a given peer IP will contain transit IPs of the same family as the peer's IP.
transitIPs map[netip.Addr]map[netip.Addr]appAddr
config config
}