gotosocial/internal/federation/dereferencing/account.go
2022-02-08 13:17:10 +01:00

395 lines
14 KiB
Go

/*
GoToSocial
Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package dereferencing
import (
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net/url"
"strings"
"sync"
"time"
"github.com/sirupsen/logrus"
"github.com/superseriousbusiness/activity/streams"
"github.com/superseriousbusiness/activity/streams/vocab"
"github.com/superseriousbusiness/gotosocial/internal/ap"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
"github.com/superseriousbusiness/gotosocial/internal/id"
"github.com/superseriousbusiness/gotosocial/internal/media"
"github.com/superseriousbusiness/gotosocial/internal/transport"
)
func instanceAccount(account *gtsmodel.Account) bool {
return strings.EqualFold(account.Username, account.Domain) ||
account.FollowersURI == "" ||
account.FollowingURI == "" ||
(account.Username == "internal.fetch" && strings.Contains(account.Note, "internal service actor"))
}
// GetRemoteAccount completely dereferences a remote account, converts it to a GtS model account,
// puts it in the database, and returns it to a caller.
//
// Refresh indicates whether--if the account exists in our db already--it should be refreshed by calling
// the remote instance again. Blocking indicates whether the function should block until processing of
// the fetched account is complete.
//
// SIDE EFFECTS: remote account will be stored in the database, or updated if it already exists (and refresh is true).
func (d *deref) GetRemoteAccount(ctx context.Context, username string, remoteAccountID *url.URL, blocking bool, refresh bool) (*gtsmodel.Account, error) {
new := true
// check if we already have the account in our db, and just return it unless we'd doing a refresh
remoteAccount, err := d.db.GetAccountByURI(ctx, remoteAccountID.String())
if err == nil {
new = false
if !refresh {
// make sure the account fields are populated before returning:
// even if we're not doing a refresh, the caller might want to block
// until everything is loaded
changed, err := d.populateAccountFields(ctx, remoteAccount, username, refresh, blocking)
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error populating remoteAccount fields: %s", err)
}
if changed {
updatedAccount, err := d.db.UpdateAccount(ctx, remoteAccount)
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error updating remoteAccount: %s", err)
}
return updatedAccount, err
}
return remoteAccount, nil
}
}
if new {
// we haven't seen this account before: dereference it from remote
accountable, err := d.dereferenceAccountable(ctx, username, remoteAccountID)
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error dereferencing accountable: %s", err)
}
newAccount, err := d.typeConverter.ASRepresentationToAccount(ctx, accountable, refresh)
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error converting accountable to account: %s", err)
}
ulid, err := id.NewRandomULID()
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error generating new id for account: %s", err)
}
newAccount.ID = ulid
if _, err := d.populateAccountFields(ctx, newAccount, username, refresh, blocking); err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error populating further account fields: %s", err)
}
if err := d.db.Put(ctx, newAccount); err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error putting new account: %s", err)
}
return newAccount, nil
}
// we have seen this account before, but we have to refresh it
refreshedAccountable, err := d.dereferenceAccountable(ctx, username, remoteAccountID)
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error dereferencing refreshedAccountable: %s", err)
}
refreshedAccount, err := d.typeConverter.ASRepresentationToAccount(ctx, refreshedAccountable, refresh)
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error converting refreshedAccountable to refreshedAccount: %s", err)
}
refreshedAccount.ID = remoteAccount.ID
changed, err := d.populateAccountFields(ctx, refreshedAccount, username, refresh, blocking)
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error populating further refreshedAccount fields: %s", err)
}
if changed {
updatedAccount, err := d.db.UpdateAccount(ctx, refreshedAccount)
if err != nil {
return nil, fmt.Errorf("GetRemoteAccount: error updating refreshedAccount: %s", err)
}
return updatedAccount, nil
}
return refreshedAccount, nil
}
// dereferenceAccountable calls remoteAccountID with a GET request, and tries to parse whatever
// it finds as something that an account model can be constructed out of.
//
// Will work for Person, Application, or Service models.
func (d *deref) dereferenceAccountable(ctx context.Context, username string, remoteAccountID *url.URL) (ap.Accountable, error) {
d.startHandshake(username, remoteAccountID)
defer d.stopHandshake(username, remoteAccountID)
if blocked, err := d.db.IsDomainBlocked(ctx, remoteAccountID.Host); blocked || err != nil {
return nil, fmt.Errorf("DereferenceAccountable: domain %s is blocked", remoteAccountID.Host)
}
transport, err := d.transportController.NewTransportForUsername(ctx, username)
if err != nil {
return nil, fmt.Errorf("DereferenceAccountable: transport err: %s", err)
}
b, err := transport.Dereference(ctx, remoteAccountID)
if err != nil {
return nil, fmt.Errorf("DereferenceAccountable: error deferencing %s: %s", remoteAccountID.String(), err)
}
m := make(map[string]interface{})
if err := json.Unmarshal(b, &m); err != nil {
return nil, fmt.Errorf("DereferenceAccountable: error unmarshalling bytes into json: %s", err)
}
t, err := streams.ToType(ctx, m)
if err != nil {
return nil, fmt.Errorf("DereferenceAccountable: error resolving json into ap vocab type: %s", err)
}
switch t.GetTypeName() {
case ap.ActorApplication:
p, ok := t.(vocab.ActivityStreamsApplication)
if !ok {
return nil, errors.New("DereferenceAccountable: error resolving type as activitystreams application")
}
return p, nil
case ap.ActorGroup:
p, ok := t.(vocab.ActivityStreamsGroup)
if !ok {
return nil, errors.New("DereferenceAccountable: error resolving type as activitystreams group")
}
return p, nil
case ap.ActorOrganization:
p, ok := t.(vocab.ActivityStreamsOrganization)
if !ok {
return nil, errors.New("DereferenceAccountable: error resolving type as activitystreams organization")
}
return p, nil
case ap.ActorPerson:
p, ok := t.(vocab.ActivityStreamsPerson)
if !ok {
return nil, errors.New("DereferenceAccountable: error resolving type as activitystreams person")
}
return p, nil
case ap.ActorService:
p, ok := t.(vocab.ActivityStreamsService)
if !ok {
return nil, errors.New("DereferenceAccountable: error resolving type as activitystreams service")
}
return p, nil
}
return nil, fmt.Errorf("DereferenceAccountable: type name %s not supported", t.GetTypeName())
}
// populateAccountFields populates any fields on the given account that weren't populated by the initial
// dereferencing. This includes things like header and avatar etc.
func (d *deref) populateAccountFields(ctx context.Context, account *gtsmodel.Account, requestingUsername string, blocking bool, refresh bool) (bool, error) {
// if we're dealing with an instance account, just bail, we don't need to do anything
if instanceAccount(account) {
return false, nil
}
accountURI, err := url.Parse(account.URI)
if err != nil {
return false, fmt.Errorf("populateAccountFields: couldn't parse account URI %s: %s", account.URI, err)
}
if blocked, err := d.db.IsDomainBlocked(ctx, accountURI.Host); blocked || err != nil {
return false, fmt.Errorf("populateAccountFields: domain %s is blocked", accountURI.Host)
}
t, err := d.transportController.NewTransportForUsername(ctx, requestingUsername)
if err != nil {
return false, fmt.Errorf("populateAccountFields: error getting transport for user: %s", err)
}
// fetch the header and avatar
changed, err := d.fetchRemoteAccountMedia(ctx, account, t, refresh, blocking)
if err != nil {
return false, fmt.Errorf("populateAccountFields: error fetching header/avi for account: %s", err)
}
return changed, nil
}
// fetchRemoteAccountMedia fetches and stores the header and avatar for a remote account,
// using a transport on behalf of requestingUsername.
//
// The returned boolean indicates whether anything changed -- in other words, whether the
// account should be updated in the database.
//
// targetAccount's AvatarMediaAttachmentID and HeaderMediaAttachmentID will be updated as necessary.
//
// If refresh is true, then the media will be fetched again even if it's already been fetched before.
//
// If blocking is true, then the calls to the media manager made by this function will be blocking:
// in other words, the function won't return until the header and the avatar have been fully processed.
func (d *deref) fetchRemoteAccountMedia(ctx context.Context, targetAccount *gtsmodel.Account, t transport.Transport, blocking bool, refresh bool) (bool, error) {
changed := false
accountURI, err := url.Parse(targetAccount.URI)
if err != nil {
return changed, fmt.Errorf("fetchRemoteAccountMedia: couldn't parse account URI %s: %s", targetAccount.URI, err)
}
if blocked, err := d.db.IsDomainBlocked(ctx, accountURI.Host); blocked || err != nil {
return changed, fmt.Errorf("fetchRemoteAccountMedia: domain %s is blocked", accountURI.Host)
}
if targetAccount.AvatarRemoteURL != "" && (targetAccount.AvatarMediaAttachmentID == "" || refresh) {
var processingMedia *media.ProcessingMedia
d.dereferencingAvatarsLock.Lock() // LOCK HERE
// first check if we're already processing this media
if alreadyProcessing, ok := d.dereferencingAvatars[targetAccount.ID]; ok {
// we're already on it, no worries
processingMedia = alreadyProcessing
}
if processingMedia == nil {
// we're not already processing it so start now
avatarIRI, err := url.Parse(targetAccount.AvatarRemoteURL)
if err != nil {
d.dereferencingAvatarsLock.Unlock()
return changed, err
}
data := func(innerCtx context.Context) (io.Reader, int, error) {
return t.DereferenceMedia(innerCtx, avatarIRI)
}
avatar := true
newProcessing, err := d.mediaManager.ProcessMedia(ctx, data, targetAccount.ID, &media.AdditionalMediaInfo{
RemoteURL: &targetAccount.AvatarRemoteURL,
Avatar: &avatar,
})
if err != nil {
d.dereferencingAvatarsLock.Unlock()
return changed, err
}
// store it in our map to indicate it's in process
d.dereferencingAvatars[targetAccount.ID] = newProcessing
processingMedia = newProcessing
}
d.dereferencingAvatarsLock.Unlock() // UNLOCK HERE
// block until loaded if required...
if blocking {
if err := lockAndLoad(ctx, d.dereferencingAvatarsLock, processingMedia, d.dereferencingAvatars, targetAccount.ID); err != nil {
return changed, err
}
} else {
// ...otherwise do it async
go func() {
dlCtx, done := context.WithDeadline(context.Background(), time.Now().Add(1*time.Minute))
if err := lockAndLoad(dlCtx, d.dereferencingAvatarsLock, processingMedia, d.dereferencingAvatars, targetAccount.ID); err != nil {
logrus.Errorf("fetchRemoteAccountMedia: error during async lock and load of avatar: %s", err)
}
done()
}()
}
targetAccount.AvatarMediaAttachmentID = processingMedia.AttachmentID()
changed = true
}
if targetAccount.HeaderRemoteURL != "" && (targetAccount.HeaderMediaAttachmentID == "" || refresh) {
var processingMedia *media.ProcessingMedia
d.dereferencingHeadersLock.Lock() // LOCK HERE
// first check if we're already processing this media
if alreadyProcessing, ok := d.dereferencingHeaders[targetAccount.ID]; ok {
// we're already on it, no worries
processingMedia = alreadyProcessing
}
if processingMedia == nil {
// we're not already processing it so start now
headerIRI, err := url.Parse(targetAccount.HeaderRemoteURL)
if err != nil {
d.dereferencingAvatarsLock.Unlock()
return changed, err
}
data := func(innerCtx context.Context) (io.Reader, int, error) {
return t.DereferenceMedia(innerCtx, headerIRI)
}
header := true
newProcessing, err := d.mediaManager.ProcessMedia(ctx, data, targetAccount.ID, &media.AdditionalMediaInfo{
RemoteURL: &targetAccount.HeaderRemoteURL,
Header: &header,
})
if err != nil {
d.dereferencingAvatarsLock.Unlock()
return changed, err
}
// store it in our map to indicate it's in process
d.dereferencingHeaders[targetAccount.ID] = newProcessing
processingMedia = newProcessing
}
d.dereferencingHeadersLock.Unlock() // UNLOCK HERE
// block until loaded if required...
if blocking {
if err := lockAndLoad(ctx, d.dereferencingHeadersLock, processingMedia, d.dereferencingHeaders, targetAccount.ID); err != nil {
return changed, err
}
} else {
// ...otherwise do it async
go func() {
dlCtx, done := context.WithDeadline(context.Background(), time.Now().Add(1*time.Minute))
if err := lockAndLoad(dlCtx, d.dereferencingHeadersLock, processingMedia, d.dereferencingHeaders, targetAccount.ID); err != nil {
logrus.Errorf("fetchRemoteAccountMedia: error during async lock and load of header: %s", err)
}
done()
}()
}
targetAccount.HeaderMediaAttachmentID = processingMedia.AttachmentID()
changed = true
}
return changed, nil
}
func lockAndLoad(ctx context.Context, lock *sync.Mutex, processing *media.ProcessingMedia, processingMap map[string]*media.ProcessingMedia, accountID string) error {
// whatever happens, remove the in-process media from the map
defer func() {
lock.Lock()
delete(processingMap, accountID)
lock.Unlock()
}()
// try and load it
_, err := processing.LoadAttachment(ctx)
return err
}