dendrite/federationsender/internal/perform/join.go

71 lines
2.2 KiB
Go

package perform
import (
"context"
"fmt"
"github.com/matrix-org/gomatrixserverlib"
)
// This file contains helpers for the PerformJoin function.
type joinContext struct {
federation *gomatrixserverlib.FederationClient
keyRing *gomatrixserverlib.KeyRing
}
// Returns a new join context.
func JoinContext(f *gomatrixserverlib.FederationClient, k *gomatrixserverlib.KeyRing) *joinContext {
return &joinContext{
federation: f,
keyRing: k,
}
}
// checkSendJoinResponse checks that all of the signatures are correct
// and that the join is allowed by the supplied state.
func (r joinContext) CheckSendJoinResponse(
ctx context.Context,
event gomatrixserverlib.Event,
server gomatrixserverlib.ServerName,
respMakeJoin gomatrixserverlib.RespMakeJoin,
respSendJoin gomatrixserverlib.RespSendJoin,
) error {
// A list of events that we have retried, if they were not included in
// the auth events supplied in the send_join.
retries := map[string]bool{}
retryCheck:
// TODO: Can we expand Check here to return a list of missing auth
// events rather than failing one at a time?
if err := respSendJoin.Check(ctx, r.keyRing, event); err != nil {
switch e := err.(type) {
case gomatrixserverlib.MissingAuthEventError:
// Check that we haven't already retried for this event, prevents
// us from ending up in endless loops
if !retries[e.AuthEventID] {
// Ask the server that we're talking to right now for the event
tx, txerr := r.federation.GetEvent(ctx, server, e.AuthEventID)
if txerr != nil {
return fmt.Errorf("r.federation.GetEvent: %w", txerr)
}
// For each event returned, add it to the auth events.
for _, pdu := range tx.PDUs {
ev, everr := gomatrixserverlib.NewEventFromUntrustedJSON(pdu, respMakeJoin.RoomVersion)
if everr != nil {
return fmt.Errorf("gomatrixserverlib.NewEventFromUntrustedJSON: %w", everr)
}
respSendJoin.AuthEvents = append(respSendJoin.AuthEvents, ev)
}
// Mark the event as retried and then give the check another go.
retries[e.AuthEventID] = true
goto retryCheck
}
return fmt.Errorf("respSendJoin (after retries): %w", e)
default:
return fmt.Errorf("respSendJoin: %w", err)
}
}
return nil
}