felhom.eu/hub/internal/api/wg.go

package api

// S1 offsite connectivity (doc 06 §3.2/§5): the operator admin surface for the WG endpoint
// record + peer registry. GLOBAL key ONLY on every route (the handleAdminSetDesiredState gate) —
// a per-host key must never author the peer list; the box-facing registration path is S2.
// DELETE takes the pubkey in the JSON body: WG pubkeys are std base64 ('/' and '+'), so a pubkey
// NEVER appears in a URL path — and no, URL-escaping is not the fix (see the S1 spec §8).

import (
	"context"
	"database/sql"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/netip"
	"time"

	"gitea.dooplex.hu/admin/felhom-hub/internal/store"
)

// WGSyncer is the reconciler seam (satisfied by *wgsync.Reconciler; tests inject a fake). nil =
// peer-sync disabled: mutations still hit the DB (the source of truth) and report sync:"disabled".
type WGSyncer interface {
	SyncNow(ctx context.Context) error
	Trigger()
}

// SetWGSyncer wires the wgsync reconciler (mirror of SetLatestVersionProvider; nil-safe).
func (h *Handler) SetWGSyncer(s WGSyncer) {
	h.wgSyncer = s
}

// validateWGPubkey enforces the exact WG public-key shape: 44 chars of std base64 decoding to
// 32 bytes. Anything else is rejected before any allocation.
func validateWGPubkey(pk string) error {
	if len(pk) != 44 {
		return fmt.Errorf("pubkey must be 44 base64 chars, got %d", len(pk))
	}
	raw, err := base64.StdEncoding.DecodeString(pk)
	if err != nil {
		return fmt.Errorf("pubkey is not valid base64: %v", err)
	}
	if len(raw) != 32 {
		return fmt.Errorf("pubkey must decode to 32 bytes, got %d", len(raw))
	}
	return nil
}

// syncAfterMutation runs an inline sync after a peer mutation. The DB write already happened —
// it is the source of truth — so a push failure is REPORTED, not rolled back: the reconciler's
// next tick converges the endpoint (Scenario D).
func (h *Handler) syncAfterMutation(ctx context.Context) string {
	if h.wgSyncer == nil {
		return "disabled"
	}
	syncCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
	defer cancel()
	if err := h.wgSyncer.SyncNow(syncCtx); err != nil {
		h.logger.Printf("[ERROR] wgsync: inline push after mutation failed: %v (reconciler will retry)", err)
		h.wgSyncer.Trigger()
		return "deferred: " + err.Error()
	}
	return "ok"
}

// handleAdminSetWGEndpoint — PUT /admin/wg/endpoint. Upserts the endpoint record.
func (h *Handler) handleAdminSetWGEndpoint(w http.ResponseWriter, r *http.Request) {
	_, _, isGlobal, ok := h.checkAuthHost(r)
	if !ok || !isGlobal {
		http.Error(w, "Forbidden: global key required", http.StatusForbidden)
		return
	}
	body, err := io.ReadAll(io.LimitReader(r.Body, 1<<20))
	if err != nil {
		http.Error(w, "Bad request", http.StatusBadRequest)
		return
	}
	var req struct {
		EndpointID   string `json:"endpoint_id"`
		DNSName      string `json:"dns_name"`
		WGPort       int    `json:"wg_port"`
		ServerPubkey string `json:"server_pubkey"`
		TunnelSubnet string `json:"tunnel_subnet"`
		PBSTunnelIP  string `json:"pbs_tunnel_ip"`
	}
	if err := json.Unmarshal(body, &req); err != nil {
		http.Error(w, "Invalid payload: body must be JSON", http.StatusBadRequest)
		return
	}
	if req.DNSName == "" {
		http.Error(w, "Invalid payload: dns_name required", http.StatusBadRequest)
		return
	}
	if req.WGPort < 1 || req.WGPort > 65535 {
		http.Error(w, "Invalid payload: wg_port must be 1-65535", http.StatusBadRequest)
		return
	}
	if err := validateWGPubkey(req.ServerPubkey); err != nil {
		http.Error(w, "Invalid payload: server_pubkey: "+err.Error(), http.StatusBadRequest)
		return
	}
	prefix, err := netip.ParsePrefix(req.TunnelSubnet)
	if err != nil {
		http.Error(w, "Invalid payload: tunnel_subnet must be CIDR", http.StatusBadRequest)
		return
	}
	pbsAddr, err := netip.ParseAddr(req.PBSTunnelIP)
	if err != nil || !prefix.Contains(pbsAddr) {
		http.Error(w, "Invalid payload: pbs_tunnel_ip must be an address inside tunnel_subnet", http.StatusBadRequest)
		return
	}
	if err := h.store.SetWGEndpoint(&store.WGEndpoint{
		EndpointID: req.EndpointID, DNSName: req.DNSName, WGPort: req.WGPort,
		ServerPubkey: req.ServerPubkey, TunnelSubnet: req.TunnelSubnet, PBSTunnelIP: req.PBSTunnelIP,
	}); err != nil {
		h.logger.Printf("[ERROR] set wg endpoint: %v", err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	h.logger.Printf("[INFO] wg endpoint set: %s (%s:%d, subnet %s)", req.DNSName, req.DNSName, req.WGPort, req.TunnelSubnet)
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	w.Write([]byte(`{"status":"ok"}`))
}

// handleAdminGetWGEndpoint — GET /admin/wg/endpoint.
func (h *Handler) handleAdminGetWGEndpoint(w http.ResponseWriter, r *http.Request) {
	_, _, isGlobal, ok := h.checkAuthHost(r)
	if !ok || !isGlobal {
		http.Error(w, "Forbidden: global key required", http.StatusForbidden)
		return
	}
	e, err := h.store.GetWGEndpoint()
	if err == sql.ErrNoRows {
		http.Error(w, "wg endpoint not configured", http.StatusNotFound)
		return
	}
	if err != nil {
		h.logger.Printf("[ERROR] get wg endpoint: %v", err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{
		"endpoint_id": e.EndpointID, "dns_name": e.DNSName, "wg_port": e.WGPort,
		"server_pubkey": e.ServerPubkey, "tunnel_subnet": e.TunnelSubnet, "pbs_tunnel_ip": e.PBSTunnelIP,
	})
}

// handleAdminAddWGPeer — POST /admin/wg/peers. Allocates a /32 (idempotent on pubkey) and
// pushes the full list inline (sync semantics: ok | deferred | disabled).
func (h *Handler) handleAdminAddWGPeer(w http.ResponseWriter, r *http.Request) {
	_, _, isGlobal, ok := h.checkAuthHost(r)
	if !ok || !isGlobal {
		http.Error(w, "Forbidden: global key required", http.StatusForbidden)
		return
	}
	body, err := io.ReadAll(io.LimitReader(r.Body, 1<<20))
	if err != nil {
		http.Error(w, "Bad request", http.StatusBadRequest)
		return
	}
	var req struct {
		Pubkey string `json:"pubkey"`
		HostID string `json:"host_id"`
		Note   string `json:"note"`
	}
	if err := json.Unmarshal(body, &req); err != nil {
		http.Error(w, "Invalid payload: body must be JSON", http.StatusBadRequest)
		return
	}
	if err := validateWGPubkey(req.Pubkey); err != nil {
		http.Error(w, "Invalid payload: "+err.Error(), http.StatusBadRequest)
		return
	}
	ip, existed, err := h.store.AddWGPeer(req.Pubkey, req.HostID, req.Note)
	if err == store.ErrWGEndpointUnset {
		http.Error(w, "wg endpoint not configured", http.StatusConflict)
		return
	}
	if err == store.ErrWGSubnetExhausted {
		http.Error(w, "tunnel subnet exhausted", http.StatusConflict)
		return
	}
	if err != nil {
		h.logger.Printf("[ERROR] add wg peer: %v", err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	syncStatus := h.syncAfterMutation(r.Context())
	h.logger.Printf("[INFO] wg peer added: %s -> %s/32 (existed=%v, sync=%s)", req.Pubkey, ip, existed, syncStatus)
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]interface{}{
		"pubkey": req.Pubkey, "assigned_ip": ip + "/32", "existed": existed, "sync": syncStatus,
	})
}

// handleAdminDeleteWGPeer — DELETE /admin/wg/peers, pubkey in the JSON body (never the URL).
// Unknown pubkey → 404 with NO sync (nothing changed). Known → delete + inline push: the pushed
// full list no longer contains the peer, so revocation lands with the push (Scenario B).
func (h *Handler) handleAdminDeleteWGPeer(w http.ResponseWriter, r *http.Request) {
	_, _, isGlobal, ok := h.checkAuthHost(r)
	if !ok || !isGlobal {
		http.Error(w, "Forbidden: global key required", http.StatusForbidden)
		return
	}
	body, err := io.ReadAll(io.LimitReader(r.Body, 1<<20))
	if err != nil {
		http.Error(w, "Bad request", http.StatusBadRequest)
		return
	}
	var req struct {
		Pubkey string `json:"pubkey"`
	}
	if err := json.Unmarshal(body, &req); err != nil {
		http.Error(w, "Invalid payload: body must be JSON", http.StatusBadRequest)
		return
	}
	if err := validateWGPubkey(req.Pubkey); err != nil {
		http.Error(w, "Invalid payload: "+err.Error(), http.StatusBadRequest)
		return
	}
	err = h.store.RemoveWGPeer(req.Pubkey)
	if err == sql.ErrNoRows {
		http.Error(w, "Unknown pubkey", http.StatusNotFound)
		return
	}
	if err != nil {
		h.logger.Printf("[ERROR] remove wg peer: %v", err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	syncStatus := h.syncAfterMutation(r.Context())
	h.logger.Printf("[INFO] wg peer removed: %s (sync=%s)", req.Pubkey, syncStatus)
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]interface{}{"status": "ok", "sync": syncStatus})
}

// handleAdminListWGPeers — GET /admin/wg/peers. The verification surface (S2 builds UI on top).
func (h *Handler) handleAdminListWGPeers(w http.ResponseWriter, r *http.Request) {
	_, _, isGlobal, ok := h.checkAuthHost(r)
	if !ok || !isGlobal {
		http.Error(w, "Forbidden: global key required", http.StatusForbidden)
		return
	}
	peers, err := h.store.ListWGPeers()
	if err != nil {
		h.logger.Printf("[ERROR] list wg peers: %v", err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	out := make([]map[string]interface{}, 0, len(peers))
	for _, p := range peers {
		out = append(out, map[string]interface{}{
			"pubkey": p.Pubkey, "assigned_ip": p.AssignedIP + "/32", "host_id": p.HostID, "note": p.Note,
		})
	}
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{"peers": out})
}