Files
Gokapi/internal/storage/FileServing.go

273 lines
8.2 KiB
Go

package storage
/**
Serving and processing uploaded files
*/
import (
"Gokapi/internal/configuration"
"Gokapi/internal/configuration/downloadstatus"
"Gokapi/internal/helper"
"Gokapi/internal/models"
"Gokapi/internal/storage/aws"
"bytes"
"crypto/sha1"
"encoding/hex"
"fmt"
"io"
"io/ioutil"
"mime/multipart"
"net/http"
"os"
"path/filepath"
"strconv"
"strings"
"time"
)
// NewFile creates a new file in the system. Called after an upload has been completed. If a file with the same sha256 hash
// already exists, it is deduplicated. This function gathers information about the file, creates an ID and saves
// it into the global configuration.
func NewFile(fileContent io.Reader, fileHeader *multipart.FileHeader, uploadRequest models.UploadRequest) (models.File, error) {
id := helper.GenerateRandomString(configuration.GetLengthId())
reader, hash, tempFile := generateHash(fileContent, fileHeader, uploadRequest)
defer deleteTempFile(tempFile)
file := models.File{
Id: id,
Name: fileHeader.Filename,
SHA256: hex.EncodeToString(hash),
Size: helper.ByteCountSI(fileHeader.Size),
ExpireAt: uploadRequest.ExpiryTimestamp,
ExpireAtString: time.Unix(uploadRequest.ExpiryTimestamp, 0).Format("2006-01-02 15:04"),
DownloadsRemaining: uploadRequest.AllowedDownloads,
PasswordHash: configuration.HashPassword(uploadRequest.Password, true),
ContentType: fileHeader.Header.Get("Content-Type"),
}
addHotlink(&file)
settings := configuration.GetServerSettings()
filename := settings.DataDir + "/" + file.SHA256
dataDir := settings.DataDir
file.AwsBucket = settings.AwsBucket
settings.Files[id] = file
configuration.ReleaseAndSave()
if !aws.IsCredentialProvided(false) {
if !helper.FileExists(dataDir + "/" + file.SHA256) {
destinationFile, err := os.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
if err != nil {
return models.File{}, err
}
defer destinationFile.Close()
_, err = io.Copy(destinationFile, reader)
if err != nil {
return models.File{}, err
}
}
} else {
_, err := aws.Upload(reader, file)
if err != nil {
return models.File{}, err
}
}
return file, nil
}
func deleteTempFile(file *os.File) {
if file == nil {
return
}
file.Close()
err := os.Remove(file.Name())
helper.Check(err)
}
func generateHash(fileContent io.Reader, fileHeader *multipart.FileHeader, uploadRequest models.UploadRequest) (io.Reader, []byte, *os.File) {
hash := sha1.New()
if fileHeader.Size <= int64(uploadRequest.MaxMemory)*1024*1024 {
content, err := ioutil.ReadAll(fileContent)
helper.Check(err)
hash.Write(content)
return bytes.NewReader(content), hash.Sum(nil), nil
}
tempFile, err := os.CreateTemp(uploadRequest.DataDir, "upload")
helper.Check(err)
_, err = io.Copy(tempFile, fileContent)
helper.Check(err)
_, err = io.Copy(hash, tempFile)
helper.Check(err)
_, err = tempFile.Seek(0, io.SeekStart)
helper.Check(err)
return tempFile, hash.Sum(nil), tempFile
}
var imageFileExtensions = []string{".jpg", ".jpeg", ".png", ".gif", ".webp", ".bmp", ".svg"}
// If file is an image, create link for hotlinking
func addHotlink(file *models.File) {
extension := strings.ToLower(filepath.Ext(file.Name))
if !helper.IsInArray(imageFileExtensions, extension) {
return
}
link := helper.GenerateRandomString(40) + extension
file.HotlinkId = link
settings := configuration.GetServerSettings()
settings.Hotlinks[link] = models.Hotlink{
Id: link,
FileId: file.Id,
}
configuration.Release()
}
// GetFile gets the file by id. Returns (empty File, false) if invalid / expired file
// or (file, true) if valid file
func GetFile(id string) (models.File, bool) {
var emptyResult = models.File{}
if id == "" {
return emptyResult, false
}
settings := configuration.GetServerSettings()
file := settings.Files[id]
configuration.Release()
if file.ExpireAt < time.Now().Unix() || file.DownloadsRemaining < 1 {
return emptyResult, false
}
if !FileExists(file, settings.DataDir) {
return emptyResult, false
}
return file, true
}
// GetFileByHotlink gets the file by hotlink id. Returns (empty File, false) if invalid / expired file
// or (file, true) if valid file
func GetFileByHotlink(id string) (models.File, bool) {
var emptyResult = models.File{}
if id == "" {
return emptyResult, false
}
settings := configuration.GetServerSettings()
hotlink := settings.Hotlinks[id]
configuration.Release()
return GetFile(hotlink.FileId)
}
// ServeFile subtracts a download allowance and serves the file to the browser
func ServeFile(file models.File, w http.ResponseWriter, r *http.Request, forceDownload bool) {
file.DownloadsRemaining = file.DownloadsRemaining - 1
settings := configuration.GetServerSettings()
settings.Files[file.Id] = file
dataDir := settings.DataDir
configuration.Release()
// If file is not stored on AWS
if file.AwsBucket == "" {
storageData, size := getFileHandler(file, dataDir)
defer storageData.Close()
if forceDownload {
w.Header().Set("Content-Disposition", "attachment; filename=\""+file.Name+"\"")
}
w.Header().Set("Content-Length", strconv.FormatInt(size, 10))
w.Header().Set("Content-Type", file.ContentType)
statusId := downloadstatus.SetDownload(file)
http.ServeContent(w, r, file.Name, time.Now(), storageData)
downloadstatus.SetComplete(statusId)
} else {
// If file is stored on AWS
downloadstatus.SetDownload(file)
err := aws.RedirectToDownload(w, r, file)
helper.Check(err)
// We are not setting a download complete status, as there is no reliable way to confirm that the
// file has been completely downloaded. It expires automatically after 24 hours.
}
}
func getFileHandler(file models.File, dataDir string) (*os.File, int64) {
storageData, err := os.OpenFile(dataDir+"/"+file.SHA256, os.O_RDONLY, 0644)
helper.Check(err)
size, err := helper.GetFileSize(storageData)
helper.Check(err)
return storageData, size
}
// FileExists checks if the file exists locally or in S3
func FileExists(file models.File, dataDir string) bool {
if file.AwsBucket != "" {
result, err := aws.FileExists(file)
if err != nil {
fmt.Println("Warning, cannot check file " + file.Id + ": " + err.Error())
return true
}
return result
}
return helper.FileExists(dataDir + "/" + file.SHA256)
}
// CleanUp removes expired files from the config and from the filesystem if they are not referenced by other files anymore
// Will be called periodically or after a file has been manually deleted in the admin view.
// If parameter periodic is true, this function is recursive and calls itself every hour.
func CleanUp(periodic bool) {
downloadstatus.Clean()
timeNow := time.Now().Unix()
wasItemDeleted := false
settings := configuration.GetServerSettings()
for key, element := range settings.Files {
fileExists := FileExists(element, settings.DataDir)
if (element.ExpireAt < timeNow || element.DownloadsRemaining < 1 || !fileExists) && !downloadstatus.IsCurrentlyDownloading(element, settings) {
deleteFile := true
for _, secondLoopElement := range settings.Files {
if element.Id != secondLoopElement.Id && element.SHA256 == secondLoopElement.SHA256 {
deleteFile = false
}
}
if deleteFile && fileExists {
deleteSource(element, settings.DataDir)
}
if element.HotlinkId != "" {
delete(settings.Hotlinks, element.HotlinkId)
}
delete(settings.Files, key)
wasItemDeleted = true
}
}
if wasItemDeleted {
configuration.ReleaseAndSave()
CleanUp(false)
} else {
configuration.Release()
}
if periodic {
time.Sleep(time.Hour)
go CleanUp(periodic)
}
}
func deleteSource(file models.File, dataDir string) {
var err error
if file.AwsBucket != "" {
_, err = aws.DeleteObject(file)
helper.Check(err)
} else {
err = os.Remove(dataDir + "/" + file.SHA256)
}
if err != nil {
fmt.Println(err)
}
}
// DeleteFile is called when an admin requests deletion of a file
// Returns true if file was deleted or false if ID did not exist
func DeleteFile(keyId string) bool {
if keyId == "" {
return false
}
settings := configuration.GetServerSettings()
item, ok := settings.Files[keyId]
if !ok {
configuration.Release()
return false
}
item.ExpireAt = 0
settings.Files[keyId] = item
configuration.Release()
CleanUp(false)
return true
}