import (
"container/list"
+ "context"
"crypto/md5"
"encoding/json"
"fmt"
"regexp"
"runtime"
"strconv"
+ "strings"
"sync"
"time"
)
// Replace the current trash queue.
rest.HandleFunc(`/trash`, TrashHandler).Methods("PUT")
+ // Untrash moves blocks from trash back into store
+ rest.HandleFunc(`/untrash/{hash:[0-9a-f]{32}}`, UntrashHandler).Methods("PUT")
+
// Any request which does not match any of these routes gets
// 400 Bad Request.
rest.NotFoundHandler = http.HandlerFunc(BadRequestHandler)
// GetBlockHandler is a HandleFunc to address Get block requests.
func GetBlockHandler(resp http.ResponseWriter, req *http.Request) {
- if enforcePermissions {
+ ctx := contextForResponse(context.TODO(), resp)
+
+ if theConfig.RequireSignatures {
locator := req.URL.Path[1:] // strip leading slash
- if err := VerifySignature(locator, GetApiToken(req)); err != nil {
+ if err := VerifySignature(locator, GetAPIToken(req)); err != nil {
http.Error(resp, err.Error(), err.(*KeepError).HTTPCode)
return
}
}
- block, err := GetBlock(mux.Vars(req)["hash"])
+ // TODO: Probe volumes to check whether the block _might_
+ // exist. Some volumes/types could support a quick existence
+ // check without causing other operations to suffer. If all
+ // volumes support that, and assure us the block definitely
+ // isn't here, we can return 404 now instead of waiting for a
+ // buffer.
+
+ buf, err := getBufferWithContext(ctx, bufs, BlockSize)
if err != nil {
- // This type assertion is safe because the only errors
- // GetBlock can return are DiskHashError or NotFoundError.
- http.Error(resp, err.Error(), err.(*KeepError).HTTPCode)
+ http.Error(resp, err.Error(), http.StatusServiceUnavailable)
return
}
- defer bufs.Put(block)
+ defer bufs.Put(buf)
- resp.Header().Set("Content-Length", strconv.Itoa(len(block)))
+ size, err := GetBlock(ctx, mux.Vars(req)["hash"], buf, resp)
+ if err != nil {
+ code := http.StatusInternalServerError
+ if err, ok := err.(*KeepError); ok {
+ code = err.HTTPCode
+ }
+ http.Error(resp, err.Error(), code)
+ return
+ }
+
+ resp.Header().Set("Content-Length", strconv.Itoa(size))
resp.Header().Set("Content-Type", "application/octet-stream")
- resp.Write(block)
+ resp.Write(buf[:size])
+}
+
+// Return a new context that gets cancelled by resp's
+// CloseNotifier. If resp does not implement http.CloseNotifier,
+// return parent.
+func contextForResponse(parent context.Context, resp http.ResponseWriter) context.Context {
+ cn, ok := resp.(http.CloseNotifier)
+ if !ok {
+ return parent
+ }
+ ctx, cancel := context.WithCancel(parent)
+ go func(c <-chan bool) {
+ <-c
+ cancel()
+ }(cn.CloseNotify())
+ return ctx
+}
+
+// Get a buffer from the pool -- but give up and return a non-nil
+// error if ctx ends before we get a buffer.
+func getBufferWithContext(ctx context.Context, bufs *bufferPool, bufSize int) ([]byte, error) {
+ bufReady := make(chan []byte)
+ go func() {
+ bufReady <- bufs.Get(bufSize)
+ }()
+ select {
+ case buf := <-bufReady:
+ return buf, nil
+ case <-ctx.Done():
+ go func() {
+ // Even if closeNotifier happened first, we
+ // need to keep waiting for our buf so we can
+ // return it to the pool.
+ bufs.Put(<-bufReady)
+ }()
+ return nil, ErrClientDisconnect
+ }
}
// PutBlockHandler is a HandleFunc to address Put block requests.
func PutBlockHandler(resp http.ResponseWriter, req *http.Request) {
+ ctx := contextForResponse(context.TODO(), resp)
+
hash := mux.Vars(req)["hash"]
// Detect as many error conditions as possible before reading
return
}
- buf := bufs.Get(int(req.ContentLength))
- _, err := io.ReadFull(req.Body, buf)
+ buf, err := getBufferWithContext(ctx, bufs, int(req.ContentLength))
+ if err != nil {
+ http.Error(resp, err.Error(), http.StatusServiceUnavailable)
+ return
+ }
+
+ _, err = io.ReadFull(req.Body, buf)
if err != nil {
http.Error(resp, err.Error(), 500)
bufs.Put(buf)
return
}
- replication, err := PutBlock(buf, hash)
+ replication, err := PutBlock(ctx, buf, hash)
bufs.Put(buf)
if err != nil {
// Success; add a size hint, sign the locator if possible, and
// return it to the client.
returnHash := fmt.Sprintf("%s+%d", hash, req.ContentLength)
- apiToken := GetApiToken(req)
- if PermissionSecret != nil && apiToken != "" {
- expiry := time.Now().Add(blobSignatureTTL)
+ apiToken := GetAPIToken(req)
+ if theConfig.blobSigningKey != nil && apiToken != "" {
+ expiry := time.Now().Add(theConfig.BlobSignatureTTL.Duration())
returnHash = SignLocator(returnHash, apiToken, expiry)
}
resp.Header().Set("X-Keep-Replicas-Stored", strconv.Itoa(replication))
// IndexHandler is a HandleFunc to address /index and /index/{prefix} requests.
func IndexHandler(resp http.ResponseWriter, req *http.Request) {
// Reject unauthorized requests.
- if !IsDataManagerToken(GetApiToken(req)) {
+ if !IsSystemAuth(GetAPIToken(req)) {
http.Error(resp, UnauthorizedError.Error(), UnauthorizedError.HTTPCode)
return
}
hash := mux.Vars(req)["hash"]
// Confirm that this user is an admin and has a token with unlimited scope.
- var tok = GetApiToken(req)
+ var tok = GetAPIToken(req)
if tok == "" || !CanDelete(tok) {
http.Error(resp, PermissionError.Error(), PermissionError.HTTPCode)
return
}
- if neverDelete {
+ if !theConfig.EnableDelete {
http.Error(resp, MethodDisabledError.Error(), MethodDisabledError.HTTPCode)
return
}
Failed int `json:"copies_failed"`
}
for _, vol := range KeepVM.AllWritable() {
- if err := vol.Delete(hash); err == nil {
+ if err := vol.Trash(hash); err == nil {
result.Deleted++
} else if os.IsNotExist(err) {
continue
// PullHandler processes "PUT /pull" requests for the data manager.
func PullHandler(resp http.ResponseWriter, req *http.Request) {
// Reject unauthorized requests.
- if !IsDataManagerToken(GetApiToken(req)) {
+ if !IsSystemAuth(GetAPIToken(req)) {
http.Error(resp, UnauthorizedError.Error(), UnauthorizedError.HTTPCode)
return
}
// TrashHandler processes /trash requests.
func TrashHandler(resp http.ResponseWriter, req *http.Request) {
// Reject unauthorized requests.
- if !IsDataManagerToken(GetApiToken(req)) {
+ if !IsSystemAuth(GetAPIToken(req)) {
http.Error(resp, UnauthorizedError.Error(), UnauthorizedError.HTTPCode)
return
}
trashq.ReplaceQueue(tlist)
}
-// ==============================
+// UntrashHandler processes "PUT /untrash/{hash:[0-9a-f]{32}}" requests for the data manager.
+func UntrashHandler(resp http.ResponseWriter, req *http.Request) {
+ // Reject unauthorized requests.
+ if !IsSystemAuth(GetAPIToken(req)) {
+ http.Error(resp, UnauthorizedError.Error(), UnauthorizedError.HTTPCode)
+ return
+ }
+
+ hash := mux.Vars(req)["hash"]
+
+ if len(KeepVM.AllWritable()) == 0 {
+ http.Error(resp, "No writable volumes", http.StatusNotFound)
+ return
+ }
+
+ var untrashedOn, failedOn []string
+ var numNotFound int
+ for _, vol := range KeepVM.AllWritable() {
+ err := vol.Untrash(hash)
+
+ if os.IsNotExist(err) {
+ numNotFound++
+ } else if err != nil {
+ log.Printf("Error untrashing %v on volume %v", hash, vol.String())
+ failedOn = append(failedOn, vol.String())
+ } else {
+ log.Printf("Untrashed %v on volume %v", hash, vol.String())
+ untrashedOn = append(untrashedOn, vol.String())
+ }
+ }
+
+ if numNotFound == len(KeepVM.AllWritable()) {
+ http.Error(resp, "Block not found on any of the writable volumes", http.StatusNotFound)
+ return
+ }
+
+ if len(failedOn) == len(KeepVM.AllWritable()) {
+ http.Error(resp, "Failed to untrash on all writable volumes", http.StatusInternalServerError)
+ } else {
+ respBody := "Successfully untrashed on: " + strings.Join(untrashedOn, ",")
+ if len(failedOn) > 0 {
+ respBody += "; Failed to untrash on: " + strings.Join(failedOn, ",")
+ }
+ resp.Write([]byte(respBody))
+ }
+}
+
// GetBlock and PutBlock implement lower-level code for handling
// blocks by rooting through volumes connected to the local machine.
// Once the handler has determined that system policy permits the
// should be the only part of the code that cares about which volume a
// block is stored on, so it should be responsible for figuring out
// which volume to check for fetching blocks, storing blocks, etc.
-// ==============================
-// GetBlock fetches and returns the block identified by "hash".
-//
-// On success, GetBlock returns a byte slice with the block data, and
-// a nil error.
+// GetBlock fetches the block identified by "hash" into the provided
+// buf, and returns the data size.
//
// If the block cannot be found on any volume, returns NotFoundError.
//
// If the block found does not have the correct MD5 hash, returns
// DiskHashError.
//
-func GetBlock(hash string) ([]byte, error) {
+func GetBlock(ctx context.Context, hash string, buf []byte, resp http.ResponseWriter) (int, error) {
// Attempt to read the requested hash from a keep volume.
errorToCaller := NotFoundError
for _, vol := range KeepVM.AllReadable() {
- buf, err := vol.Get(hash)
+ size, err := vol.Get(ctx, hash, buf)
+ select {
+ case <-ctx.Done():
+ return 0, ctx.Err()
+ default:
+ }
if err != nil {
// IsNotExist is an expected error and may be
// ignored. All other errors are logged. In
}
// Check the file checksum.
//
- filehash := fmt.Sprintf("%x", md5.Sum(buf))
+ filehash := fmt.Sprintf("%x", md5.Sum(buf[:size]))
if filehash != hash {
// TODO: Try harder to tell a sysadmin about
// this.
log.Printf("%s: checksum mismatch for request %s (actual %s)",
vol, hash, filehash)
errorToCaller = DiskHashError
- bufs.Put(buf)
continue
}
if errorToCaller == DiskHashError {
log.Printf("%s: checksum mismatch for request %s but a good copy was found on another volume and returned",
vol, hash)
}
- return buf, nil
+ return size, nil
}
- return nil, errorToCaller
+ return 0, errorToCaller
}
// PutBlock Stores the BLOCK (identified by the content id HASH) in Keep.
//
-// PutBlock(block, hash)
+// PutBlock(ctx, block, hash)
// Stores the BLOCK (identified by the content id HASH) in Keep.
//
// The MD5 checksum of the block must be identical to the content id HASH.
// all writes failed). The text of the error message should
// provide as much detail as possible.
//
-func PutBlock(block []byte, hash string) (int, error) {
+func PutBlock(ctx context.Context, block []byte, hash string) (int, error) {
// Check that BLOCK's checksum matches HASH.
blockhash := fmt.Sprintf("%x", md5.Sum(block))
if blockhash != hash {
// Choose a Keep volume to write to.
// If this volume fails, try all of the volumes in order.
if vol := KeepVM.NextWritable(); vol != nil {
- if err := vol.Put(hash, block); err == nil {
+ if err := vol.Put(context.TODO(), hash, block); err == nil {
return vol.Replication(), nil // success!
}
}
allFull := true
for _, vol := range writables {
- err := vol.Put(hash, block)
+ err := vol.Put(ctx, hash, block)
+ select {
+ case <-ctx.Done():
+ return 0, ctx.Err()
+ default:
+ }
if err == nil {
return vol.Replication(), nil // success!
}
var authRe = regexp.MustCompile(`^OAuth2\s+(.*)`)
-// GetApiToken returns the OAuth2 token from the Authorization
+// GetAPIToken returns the OAuth2 token from the Authorization
// header of a HTTP request, or an empty string if no matching
// token is found.
-func GetApiToken(req *http.Request) string {
+func GetAPIToken(req *http.Request) string {
if auth, ok := req.Header["Authorization"]; ok {
if match := authRe.FindStringSubmatch(auth[0]); match != nil {
return match[1]
}
// Blocks may be deleted only when Keep has been configured with a
// data manager.
- if IsDataManagerToken(apiToken) {
+ if IsSystemAuth(apiToken) {
return true
}
// TODO(twp): look up apiToken with the API server
return false
}
-// IsDataManagerToken returns true if apiToken represents the data
-// manager's token.
-func IsDataManagerToken(apiToken string) bool {
- return dataManagerToken != "" && apiToken == dataManagerToken
+// IsSystemAuth returns true if the given token is allowed to perform
+// system level actions like deleting data.
+func IsSystemAuth(token string) bool {
+ return token != "" && token == theConfig.systemAuthToken
}