gotosocial/internal/processing/media/getfile.go

286 lines
11 KiB
Go

// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// 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 media
import (
"context"
"fmt"
"io"
"net/url"
"strings"
apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
"github.com/superseriousbusiness/gotosocial/internal/gtscontext"
"github.com/superseriousbusiness/gotosocial/internal/gtserror"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
"github.com/superseriousbusiness/gotosocial/internal/media"
"github.com/superseriousbusiness/gotosocial/internal/uris"
)
// GetFile retrieves a file from storage and streams it back to the caller via an io.reader embedded in *apimodel.Content.
func (p *Processor) GetFile(ctx context.Context, requestingAccount *gtsmodel.Account, form *apimodel.GetContentRequestForm) (*apimodel.Content, gtserror.WithCode) {
// parse the form fields
mediaSize, err := parseSize(form.MediaSize)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("media size %s not valid", form.MediaSize))
}
mediaType, err := parseType(form.MediaType)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("media type %s not valid", form.MediaType))
}
spl := strings.Split(form.FileName, ".")
if len(spl) != 2 || spl[0] == "" || spl[1] == "" {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("file name %s not parseable", form.FileName))
}
wantedMediaID := spl[0]
owningAccountID := form.AccountID
// get the account that owns the media and make sure it's not suspended
owningAccount, err := p.state.DB.GetAccountByID(ctx, owningAccountID)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("account with id %s could not be selected from the db: %s", owningAccountID, err))
}
if !owningAccount.SuspendedAt.IsZero() {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("account with id %s is suspended", owningAccountID))
}
// make sure the requesting account and the media account don't block each other
if requestingAccount != nil {
blocked, err := p.state.DB.IsEitherBlocked(ctx, requestingAccount.ID, owningAccountID)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("block status could not be established between accounts %s and %s: %s", owningAccountID, requestingAccount.ID, err))
}
if blocked {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("block exists between accounts %s and %s", owningAccountID, requestingAccount.ID))
}
}
// the way we store emojis is a little different from the way we store other attachments,
// so we need to take different steps depending on the media type being requested
switch mediaType {
case media.TypeEmoji:
return p.getEmojiContent(ctx, wantedMediaID, owningAccountID, mediaSize)
case media.TypeAttachment, media.TypeHeader, media.TypeAvatar:
return p.getAttachmentContent(ctx, requestingAccount, wantedMediaID, owningAccountID, mediaSize)
default:
return nil, gtserror.NewErrorNotFound(fmt.Errorf("media type %s not recognized", mediaType))
}
}
/*
UTIL FUNCTIONS
*/
func parseType(s string) (media.Type, error) {
switch s {
case string(media.TypeAttachment):
return media.TypeAttachment, nil
case string(media.TypeHeader):
return media.TypeHeader, nil
case string(media.TypeAvatar):
return media.TypeAvatar, nil
case string(media.TypeEmoji):
return media.TypeEmoji, nil
}
return "", fmt.Errorf("%s not a recognized media.Type", s)
}
func parseSize(s string) (media.Size, error) {
switch s {
case string(media.SizeSmall):
return media.SizeSmall, nil
case string(media.SizeOriginal):
return media.SizeOriginal, nil
case string(media.SizeStatic):
return media.SizeStatic, nil
}
return "", fmt.Errorf("%s not a recognized media.Size", s)
}
func (p *Processor) getAttachmentContent(ctx context.Context, requestingAccount *gtsmodel.Account, wantedMediaID string, owningAccountID string, mediaSize media.Size) (*apimodel.Content, gtserror.WithCode) {
// retrieve attachment from the database and do basic checks on it
a, err := p.state.DB.GetAttachmentByID(ctx, wantedMediaID)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("attachment %s could not be taken from the db: %w", wantedMediaID, err))
}
if a.AccountID != owningAccountID {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("attachment %s is not owned by %s", wantedMediaID, owningAccountID))
}
if !*a.Cached {
// if we don't have it cached, then we can assume two things:
// 1. this is remote media, since local media should never be uncached
// 2. we need to fetch it again using a transport and the media manager
remoteMediaIRI, err := url.Parse(a.RemoteURL)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("error parsing remote media iri %s: %w", a.RemoteURL, err))
}
// use an empty string as requestingUsername to use the instance account, unless the request for this
// media has been http signed, then use the requesting account to make the request to remote server
var requestingUsername string
if requestingAccount != nil {
requestingUsername = requestingAccount.Username
}
// Pour one out for tobi's original streamed recache
// (streaming data both to the client and storage).
// Gone and forever missed <3
//
// [
// the reason it was removed was because a slow
// client connection could hold open a storage
// recache operation -> holding open a media worker.
// ]
dataFn := func(ctx context.Context) (io.ReadCloser, int64, error) {
t, err := p.transportController.NewTransportForUsername(ctx, requestingUsername)
if err != nil {
return nil, 0, err
}
return t.DereferenceMedia(gtscontext.SetFastFail(ctx), remoteMediaIRI)
}
// Start recaching this media with the prepared data function.
processingMedia, err := p.mediaManager.PreProcessMediaRecache(ctx, dataFn, wantedMediaID)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("error recaching media: %w", err))
}
// Load attachment and block until complete
a, err = processingMedia.LoadAttachment(ctx)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("error loading recached attachment: %w", err))
}
}
var (
storagePath string
attachmentContent = &apimodel.Content{
ContentUpdated: a.UpdatedAt,
}
)
// get file information from the attachment depending on the requested media size
switch mediaSize {
case media.SizeOriginal:
attachmentContent.ContentType = a.File.ContentType
attachmentContent.ContentLength = int64(a.File.FileSize)
storagePath = a.File.Path
case media.SizeSmall:
attachmentContent.ContentType = a.Thumbnail.ContentType
attachmentContent.ContentLength = int64(a.Thumbnail.FileSize)
storagePath = a.Thumbnail.Path
default:
return nil, gtserror.NewErrorNotFound(fmt.Errorf("media size %s not recognized for attachment", mediaSize))
}
// ... so now we can safely return it
return p.retrieveFromStorage(ctx, storagePath, attachmentContent)
}
func (p *Processor) getEmojiContent(ctx context.Context, fileName string, owningAccountID string, emojiSize media.Size) (*apimodel.Content, gtserror.WithCode) {
emojiContent := &apimodel.Content{}
var storagePath string
// reconstruct the static emoji image url -- reason
// for using the static URL rather than full size url
// is that static emojis are always encoded as png,
// so this is more reliable than using full size url
imageStaticURL := uris.GenerateURIForAttachment(
owningAccountID,
string(media.TypeEmoji),
string(media.SizeStatic),
fileName,
"png",
)
e, err := p.state.DB.GetEmojiByStaticURL(ctx, imageStaticURL)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("emoji %s could not be taken from the db: %w", fileName, err))
}
if *e.Disabled {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("emoji %s has been disabled", fileName))
}
if !*e.Cached {
// if we don't have it cached, then we can assume two things:
// 1. this is remote emoji, since local emoji should never be uncached
// 2. we need to fetch it again using a transport and the media manager
remoteURL, err := url.Parse(e.ImageRemoteURL)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("error parsing remote emoji iri %s: %w", e.ImageRemoteURL, err))
}
dataFn := func(ctx context.Context) (io.ReadCloser, int64, error) {
t, err := p.transportController.NewTransportForUsername(ctx, "")
if err != nil {
return nil, 0, err
}
return t.DereferenceMedia(gtscontext.SetFastFail(ctx), remoteURL)
}
// Start recaching this emoji with the prepared data function.
processingEmoji, err := p.mediaManager.PreProcessEmojiRecache(ctx, dataFn, e.ID)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("error recaching emoji: %w", err))
}
// Load attachment and block until complete
e, err = processingEmoji.LoadEmoji(ctx)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("error loading recached emoji: %w", err))
}
}
switch emojiSize {
case media.SizeOriginal:
emojiContent.ContentType = e.ImageContentType
emojiContent.ContentLength = int64(e.ImageFileSize)
storagePath = e.ImagePath
case media.SizeStatic:
emojiContent.ContentType = e.ImageStaticContentType
emojiContent.ContentLength = int64(e.ImageStaticFileSize)
storagePath = e.ImageStaticPath
default:
return nil, gtserror.NewErrorNotFound(fmt.Errorf("media size %s not recognized for emoji", emojiSize))
}
return p.retrieveFromStorage(ctx, storagePath, emojiContent)
}
func (p *Processor) retrieveFromStorage(ctx context.Context, storagePath string, content *apimodel.Content) (*apimodel.Content, gtserror.WithCode) {
// If running on S3 storage with proxying disabled then
// just fetch a pre-signed URL instead of serving the content.
if url := p.state.Storage.URL(ctx, storagePath); url != nil {
content.URL = url
return content, nil
}
reader, err := p.state.Storage.GetStream(ctx, storagePath)
if err != nil {
return nil, gtserror.NewErrorNotFound(fmt.Errorf("error retrieving from storage: %s", err))
}
content.Content = reader
return content, nil
}