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juanfont.headscale/hscontrol/routes/primary.go
Kristoffer Dalby 50ed24847b debug: add json and improve
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2025-09-09 09:40:00 +02:00

308 lines
8.3 KiB
Go

package routes
import (
"fmt"
"net/netip"
"slices"
"sort"
"strings"
"sync"
"github.com/juanfont/headscale/hscontrol/types"
"github.com/juanfont/headscale/hscontrol/util"
"github.com/rs/zerolog/log"
xmaps "golang.org/x/exp/maps"
"tailscale.com/net/tsaddr"
"tailscale.com/util/set"
)
type PrimaryRoutes struct {
mu sync.Mutex
// routes is a map of prefixes that are adverties and approved and available
// in the global headscale state.
routes map[types.NodeID]set.Set[netip.Prefix]
// primaries is a map of prefixes to the node that is the primary for that prefix.
primaries map[netip.Prefix]types.NodeID
isPrimary map[types.NodeID]bool
}
func New() *PrimaryRoutes {
return &PrimaryRoutes{
routes: make(map[types.NodeID]set.Set[netip.Prefix]),
primaries: make(map[netip.Prefix]types.NodeID),
isPrimary: make(map[types.NodeID]bool),
}
}
// updatePrimaryLocked recalculates the primary routes and updates the internal state.
// It returns true if the primary routes have changed.
// It is assumed that the caller holds the lock.
// The algorithm is as follows:
// 1. Reset the primaries map.
// 2. Iterate over the routes and count the number of times a prefix is advertised.
// 3. If a prefix is advertised by at least two nodes, it is a primary route.
// 4. If the primary routes have changed, update the internal state and return true.
// 5. Otherwise, return false.
func (pr *PrimaryRoutes) updatePrimaryLocked() bool {
log.Debug().Caller().Msg("updatePrimaryLocked starting")
// reset the primaries map, as we are going to recalculate it.
allPrimaries := make(map[netip.Prefix][]types.NodeID)
pr.isPrimary = make(map[types.NodeID]bool)
changed := false
// sort the node ids so we can iterate over them in a deterministic order.
// this is important so the same node is chosen two times in a row
// as the primary route.
ids := types.NodeIDs(xmaps.Keys(pr.routes))
sort.Sort(ids)
// Create a map of prefixes to nodes that serve them so we
// can determine the primary route for each prefix.
for _, id := range ids {
routes := pr.routes[id]
for route := range routes {
if _, ok := allPrimaries[route]; !ok {
allPrimaries[route] = []types.NodeID{id}
} else {
allPrimaries[route] = append(allPrimaries[route], id)
}
}
}
// Go through all prefixes and determine the primary route for each.
// If the number of routes is below the minimum, remove the primary.
// If the current primary is still available, continue.
// If the current primary is not available, select a new one.
for prefix, nodes := range allPrimaries {
log.Debug().
Caller().
Str("prefix", prefix.String()).
Uints64("availableNodes", func() []uint64 {
ids := make([]uint64, len(nodes))
for i, id := range nodes {
ids[i] = id.Uint64()
}
return ids
}()).
Msg("Processing prefix for primary route selection")
if node, ok := pr.primaries[prefix]; ok {
// If the current primary is still available, continue.
if slices.Contains(nodes, node) {
log.Debug().
Caller().
Str("prefix", prefix.String()).
Uint64("currentPrimary", node.Uint64()).
Msg("Current primary still available, keeping it")
continue
} else {
log.Debug().
Caller().
Str("prefix", prefix.String()).
Uint64("oldPrimary", node.Uint64()).
Msg("Current primary no longer available")
}
}
if len(nodes) >= 1 {
pr.primaries[prefix] = nodes[0]
changed = true
log.Debug().
Caller().
Str("prefix", prefix.String()).
Uint64("newPrimary", nodes[0].Uint64()).
Msg("Selected new primary for prefix")
}
}
// Clean up any remaining primaries that are no longer valid.
for prefix := range pr.primaries {
if _, ok := allPrimaries[prefix]; !ok {
log.Debug().
Caller().
Str("prefix", prefix.String()).
Msg("Cleaning up primary route that no longer has available nodes")
delete(pr.primaries, prefix)
changed = true
}
}
// Populate the quick lookup index for primary routes
for _, nodeID := range pr.primaries {
pr.isPrimary[nodeID] = true
}
log.Debug().
Caller().
Bool("changed", changed).
Str("finalState", pr.stringLocked()).
Msg("updatePrimaryLocked completed")
return changed
}
// SetRoutes sets the routes for a given Node ID and recalculates the primary routes
// of the headscale.
// It returns true if there was a change in primary routes.
// All exit routes are ignored as they are not used in primary route context.
func (pr *PrimaryRoutes) SetRoutes(node types.NodeID, prefixes ...netip.Prefix) bool {
pr.mu.Lock()
defer pr.mu.Unlock()
log.Debug().
Caller().
Uint64("node.id", node.Uint64()).
Strs("prefixes", util.PrefixesToString(prefixes)).
Msg("PrimaryRoutes.SetRoutes called")
// If no routes are being set, remove the node from the routes map.
if len(prefixes) == 0 {
wasPresent := false
if _, ok := pr.routes[node]; ok {
delete(pr.routes, node)
wasPresent = true
log.Debug().
Caller().
Uint64("node.id", node.Uint64()).
Msg("Removed node from primary routes (no prefixes)")
}
changed := pr.updatePrimaryLocked()
log.Debug().
Caller().
Uint64("node.id", node.Uint64()).
Bool("wasPresent", wasPresent).
Bool("changed", changed).
Str("newState", pr.stringLocked()).
Msg("SetRoutes completed (remove)")
return changed
}
rs := make(set.Set[netip.Prefix], len(prefixes))
for _, prefix := range prefixes {
if !tsaddr.IsExitRoute(prefix) {
rs.Add(prefix)
}
}
if rs.Len() != 0 {
pr.routes[node] = rs
log.Debug().
Caller().
Uint64("node.id", node.Uint64()).
Strs("routes", util.PrefixesToString(rs.Slice())).
Msg("Updated node routes in primary route manager")
} else {
delete(pr.routes, node)
log.Debug().
Caller().
Uint64("node.id", node.Uint64()).
Msg("Removed node from primary routes (only exit routes)")
}
changed := pr.updatePrimaryLocked()
log.Debug().
Caller().
Uint64("node.id", node.Uint64()).
Bool("changed", changed).
Str("newState", pr.stringLocked()).
Msg("SetRoutes completed (update)")
return changed
}
func (pr *PrimaryRoutes) PrimaryRoutes(id types.NodeID) []netip.Prefix {
if pr == nil {
return nil
}
pr.mu.Lock()
defer pr.mu.Unlock()
// Short circuit if the node is not a primary for any route.
if _, ok := pr.isPrimary[id]; !ok {
return nil
}
var routes []netip.Prefix
for prefix, node := range pr.primaries {
if node == id {
routes = append(routes, prefix)
}
}
tsaddr.SortPrefixes(routes)
return routes
}
func (pr *PrimaryRoutes) String() string {
pr.mu.Lock()
defer pr.mu.Unlock()
return pr.stringLocked()
}
func (pr *PrimaryRoutes) stringLocked() string {
var sb strings.Builder
fmt.Fprintln(&sb, "Available routes:")
ids := types.NodeIDs(xmaps.Keys(pr.routes))
sort.Sort(ids)
for _, id := range ids {
prefixes := pr.routes[id]
fmt.Fprintf(&sb, "\nNode %d: %s", id, strings.Join(util.PrefixesToString(prefixes.Slice()), ", "))
}
fmt.Fprintln(&sb, "\n\nCurrent primary routes:")
for route, nodeID := range pr.primaries {
fmt.Fprintf(&sb, "\nRoute %s: %d", route, nodeID)
}
return sb.String()
}
// DebugRoutes represents the primary routes state in a structured format for JSON serialization.
type DebugRoutes struct {
// AvailableRoutes maps node IDs to their advertised routes
// In the context of primary routes, this represents the routes that are available
// for each node. A route will only be available if it is advertised by the node
// AND approved.
// Only routes by nodes currently connected to the headscale server are included.
AvailableRoutes map[types.NodeID][]netip.Prefix `json:"available_routes"`
// PrimaryRoutes maps route prefixes to the primary node serving them
PrimaryRoutes map[string]types.NodeID `json:"primary_routes"`
}
// DebugJSON returns a structured representation of the primary routes state suitable for JSON serialization.
func (pr *PrimaryRoutes) DebugJSON() DebugRoutes {
pr.mu.Lock()
defer pr.mu.Unlock()
debug := DebugRoutes{
AvailableRoutes: make(map[types.NodeID][]netip.Prefix),
PrimaryRoutes: make(map[string]types.NodeID),
}
// Populate available routes
for nodeID, routes := range pr.routes {
prefixes := routes.Slice()
tsaddr.SortPrefixes(prefixes)
debug.AvailableRoutes[nodeID] = prefixes
}
// Populate primary routes
for prefix, nodeID := range pr.primaries {
debug.PrimaryRoutes[prefix.String()] = nodeID
}
return debug
}