From 91a13247760499930356a89f2bd314208f73a941 Mon Sep 17 00:00:00 2001 From: Steven Allen Date: Thu, 25 Jul 2019 17:30:35 -0700 Subject: [PATCH] fix and improve the writable gateway 1. Fix a panic due to an unchecked type assertion. 2. Fix handling of PUT. The simple implementation was the correct implementation, I have no idea what was going on here. 3. Use MFS everywhere to reduce code duplication and add support for sharded directories. 4. _Correctly_ block IPNS. 5. Remove the dependency on `core.IpfsNode`. --- core/corehttp/gateway.go | 2 +- core/corehttp/gateway_handler.go | 261 +++++++++++++------------------ 2 files changed, 109 insertions(+), 154 deletions(-) diff --git a/core/corehttp/gateway.go b/core/corehttp/gateway.go index d3600bb73c7d..24d26739b052 100644 --- a/core/corehttp/gateway.go +++ b/core/corehttp/gateway.go @@ -87,7 +87,7 @@ func GatewayOption(writable bool, paths ...string) ServeOption { "X-Stream-Output", }, headers[ACEHeadersName]...)) - gateway := newGatewayHandler(n, GatewayConfig{ + gateway := newGatewayHandler(GatewayConfig{ Headers: headers, Writable: writable, PathPrefixes: cfg.Gateway.PathPrefixes, diff --git a/core/corehttp/gateway_handler.go b/core/corehttp/gateway_handler.go index 1aa343a5502d..542ecf2e4388 100644 --- a/core/corehttp/gateway_handler.go +++ b/core/corehttp/gateway_handler.go @@ -2,7 +2,6 @@ package corehttp import ( "context" - "errors" "fmt" "io" "net/http" @@ -12,20 +11,13 @@ import ( "strings" "time" - "github.com/ipfs/go-ipfs/core" - "github.com/ipfs/go-ipfs/dagutils" - "github.com/ipfs/go-ipfs/namesys/resolve" - "github.com/dustin/go-humanize" "github.com/ipfs/go-cid" - chunker "github.com/ipfs/go-ipfs-chunker" files "github.com/ipfs/go-ipfs-files" - ipld "github.com/ipfs/go-ipld-format" dag "github.com/ipfs/go-merkledag" + "github.com/ipfs/go-mfs" "github.com/ipfs/go-path" "github.com/ipfs/go-path/resolver" - ft "github.com/ipfs/go-unixfs" - "github.com/ipfs/go-unixfs/importer" coreiface "github.com/ipfs/interface-go-ipfs-core" ipath "github.com/ipfs/interface-go-ipfs-core/path" routing "github.com/libp2p/go-libp2p-core/routing" @@ -40,27 +32,36 @@ const ( // gatewayHandler is a HTTP handler that serves IPFS objects (accessible by default at /ipfs/) // (it serves requests like GET /ipfs/QmVRzPKPzNtSrEzBFm2UZfxmPAgnaLke4DMcerbsGGSaFe/link) type gatewayHandler struct { - node *core.IpfsNode config GatewayConfig api coreiface.CoreAPI } -func newGatewayHandler(n *core.IpfsNode, c GatewayConfig, api coreiface.CoreAPI) *gatewayHandler { +func newGatewayHandler(c GatewayConfig, api coreiface.CoreAPI) *gatewayHandler { i := &gatewayHandler{ - node: n, config: c, api: api, } return i } -// TODO(cryptix): find these helpers somewhere else -func (i *gatewayHandler) newDagFromReader(r io.Reader) (ipld.Node, error) { - // TODO(cryptix): change and remove this helper once PR1136 is merged - // return ufs.AddFromReader(i.node, r.Body) - return importer.BuildDagFromReader( - i.node.DAG, - chunker.DefaultSplitter(r)) +func parseIpfsPath(p string) (cid.Cid, string, error) { + rootPath, err := path.ParsePath(p) + if err != nil { + return cid.Cid{}, "", err + } + + // Check the path. + rsegs := rootPath.Segments() + if rsegs[0] != "ipfs" { + return cid.Cid{}, "", fmt.Errorf("WritableGateway: only ipfs paths supported", rsegs[0]) + } + + rootCid, err := cid.Decode(rsegs[1]) + if err != nil { + return cid.Cid{}, "", err + } + + return rootCid, path.Join(rsegs[2:]), nil } func (i *gatewayHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { @@ -160,10 +161,12 @@ func (i *gatewayHandler) getOrHeadHandler(w http.ResponseWriter, r *http.Request // Resolve path to the final DAG node for the ETag resolvedPath, err := i.api.ResolvePath(r.Context(), parsedPath) - if err == coreiface.ErrOffline && !i.node.IsOnline { + switch err { + case nil: + case coreiface.ErrOffline: webError(w, "ipfs resolve -r "+escapedURLPath, err, http.StatusServiceUnavailable) return - } else if err != nil { + default: webError(w, "ipfs resolve -r "+escapedURLPath, err, http.StatusNotFound) return } @@ -395,102 +398,72 @@ func (i *gatewayHandler) postHandler(w http.ResponseWriter, r *http.Request) { } func (i *gatewayHandler) putHandler(w http.ResponseWriter, r *http.Request) { - rootPath, err := path.ParsePath(r.URL.Path) + ctx := r.Context() + ds := i.api.Dag() + + // Parse the path + rootCid, newPath, err := parseIpfsPath(r.URL.Path) if err != nil { - webError(w, "putHandler: IPFS path not valid", err, http.StatusBadRequest) + webError(w, "WritableGateway: failed to parse the path", err, http.StatusBadRequest) return } - - rsegs := rootPath.Segments() - if rsegs[0] == ipnsPathPrefix { - webError(w, "putHandler: updating named entries not supported", errors.New("WritableGateway: ipns put not supported"), http.StatusBadRequest) + if newPath == "" || newPath == "/" { + http.Error(w, "WritableGateway: empty path", http.StatusBadRequest) return } + newDirectory, _ := gopath.Split(newPath) - var newnode ipld.Node - if rsegs[len(rsegs)-1] == "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn" { - newnode = ft.EmptyDirNode() - } else { - putNode, err := i.newDagFromReader(r.Body) - if err != nil { - webError(w, "putHandler: Could not create DAG from request", err, http.StatusInternalServerError) - return - } - newnode = putNode - } + // Resolve the old root. - var newPath string - if len(rsegs) > 1 { - newPath = path.Join(rsegs[2:]) + rnode, err := ds.Get(ctx, rootCid) + if err != nil { + webError(w, "WritableGateway: Could not create DAG from request", err, http.StatusInternalServerError) + return } - var newcid cid.Cid - rnode, err := resolve.Resolve(r.Context(), i.node.Namesys, i.node.Resolver, rootPath) - switch ev := err.(type) { - case resolver.ErrNoLink: - // ev.Node < node where resolve failed - // ev.Name < new link - // but we need to patch from the root - c, err := cid.Decode(rsegs[1]) - if err != nil { - webError(w, "putHandler: bad input path", err, http.StatusBadRequest) - return - } - - rnode, err := i.node.DAG.Get(r.Context(), c) - if err != nil { - webError(w, "putHandler: Could not create DAG from request", err, http.StatusInternalServerError) - return - } - - pbnd, ok := rnode.(*dag.ProtoNode) - if !ok { - webError(w, "Cannot read non protobuf nodes through gateway", dag.ErrNotProtobuf, http.StatusBadRequest) - return - } - - e := dagutils.NewDagEditor(pbnd, i.node.DAG) - err = e.InsertNodeAtPath(r.Context(), newPath, newnode, ft.EmptyDirNode) - if err != nil { - webError(w, "putHandler: InsertNodeAtPath failed", err, http.StatusInternalServerError) - return - } - - nnode, err := e.Finalize(r.Context(), i.node.DAG) - if err != nil { - webError(w, "putHandler: could not get node", err, http.StatusInternalServerError) - return - } + pbnd, ok := rnode.(*dag.ProtoNode) + if !ok { + webError(w, "Cannot read non protobuf nodes through gateway", dag.ErrNotProtobuf, http.StatusBadRequest) + return + } - newcid = nnode.Cid() + // Create the new file. + newFilePath, err := i.api.Unixfs().Add(ctx, files.NewReaderFile(r.Body)) + if err != nil { + webError(w, "WritableGateway: could not create DAG from request", err, http.StatusInternalServerError) + return + } - case nil: - pbnd, ok := rnode.(*dag.ProtoNode) - if !ok { - webError(w, "Cannot read non protobuf nodes through gateway", dag.ErrNotProtobuf, http.StatusBadRequest) - return - } + newFile, err := ds.Get(ctx, newFilePath.Cid()) + if err != nil { + webError(w, "WritableGateway: failed to resolve new file", err, http.StatusInternalServerError) + return + } - pbnewnode, ok := newnode.(*dag.ProtoNode) - if !ok { - webError(w, "Cannot read non protobuf nodes through gateway", dag.ErrNotProtobuf, http.StatusBadRequest) - return - } + // Patch the new file into the old root. - // object set-data case - pbnd.SetData(pbnewnode.Data()) + root, err := mfs.NewRoot(ctx, ds, pbnd, nil) + if err != nil { + webError(w, "WritableGateway: failed to create MFS root", err, http.StatusBadRequest) + return + } - newcid = pbnd.Cid() - err = i.node.DAG.Add(r.Context(), pbnd) + if newDirectory != "" { + err := mfs.Mkdir(root, newDirectory, mfs.MkdirOpts{Mkparents: true, Flush: false}) if err != nil { - nnk := newnode.Cid() - webError(w, fmt.Sprintf("putHandler: Could not add newnode(%q) to root(%q)", nnk.String(), newcid.String()), err, http.StatusInternalServerError) + webError(w, "WritableGateway: failed to create MFS directory", err, http.StatusInternalServerError) return } - default: - webError(w, "could not resolve root DAG", ev, http.StatusInternalServerError) - return } + err = mfs.PutNode(root, newPath, newFile) + if err != nil { + webError(w, "WritableGateway: failed to link file into directory", err, http.StatusInternalServerError) + } + nnode, err := root.GetDirectory().GetNode() + if err != nil { + webError(w, "WritableGateway: failed to finalize", err, http.StatusInternalServerError) + } + newcid := nnode.Cid() i.addUserHeaders(w) // ok, _now_ write user's headers. w.Header().Set("IPFS-Hash", newcid.String()) @@ -498,91 +471,73 @@ func (i *gatewayHandler) putHandler(w http.ResponseWriter, r *http.Request) { } func (i *gatewayHandler) deleteHandler(w http.ResponseWriter, r *http.Request) { - urlPath := r.URL.Path + ctx := r.Context() + + // parse the path - p, err := path.ParsePath(urlPath) + rootCid, newPath, err := parseIpfsPath(r.URL.Path) if err != nil { - webError(w, "failed to parse path", err, http.StatusBadRequest) + webError(w, "WritableGateway: failed to parse the path", err, http.StatusBadRequest) return } - - c, components, err := path.SplitAbsPath(p) - if err != nil { - webError(w, "Could not split path", err, http.StatusInternalServerError) + if newPath == "" || newPath == "/" { + http.Error(w, "WritableGateway: empty path", http.StatusBadRequest) return } + directory, filename := gopath.Split(newPath) + + // lookup the root - pathNodes, err := i.resolvePathComponents(r.Context(), c, components) + rootNodeIPLD, err := i.api.Dag().Get(ctx, rootCid) if err != nil { - webError(w, "Could not resolve path components", err, http.StatusBadRequest) + webError(w, "WritableGateway: failed to resolve root CID", err, http.StatusInternalServerError) return } - - pbnd, ok := pathNodes[len(pathNodes)-1].(*dag.ProtoNode) + rootNode, ok := rootNodeIPLD.(*dag.ProtoNode) if !ok { - webError(w, "Cannot read non protobuf nodes through gateway", dag.ErrNotProtobuf, http.StatusBadRequest) + http.Error(w, "WritableGateway: empty path", http.StatusInternalServerError) return } - // TODO(cyrptix): assumes len(pathNodes) > 1 - not found is an error above? - err = pbnd.RemoveNodeLink(components[len(components)-1]) + // construct the mfs root + + root, err := mfs.NewRoot(ctx, i.api.Dag(), rootNode, nil) if err != nil { - webError(w, "Could not delete link", err, http.StatusBadRequest) + webError(w, "WritableGateway: failed to construct the MFS root", err, http.StatusBadRequest) return } - var newnode *dag.ProtoNode = pbnd - for j := len(pathNodes) - 2; j >= 0; j-- { - if err := i.node.DAG.Add(r.Context(), newnode); err != nil { - webError(w, "Could not add node", err, http.StatusInternalServerError) - return - } - - pathpb, ok := pathNodes[j].(*dag.ProtoNode) - if !ok { - webError(w, "Cannot read non protobuf nodes through gateway", dag.ErrNotProtobuf, http.StatusBadRequest) - return - } + // lookup the parent directory - newnode, err = pathpb.UpdateNodeLink(components[j], newnode) - if err != nil { - webError(w, "Could not update node links", err, http.StatusInternalServerError) - return - } + parentNode, err := mfs.Lookup(root, directory) + if err != nil { + webError(w, "WritableGateway: failed to look up parent", err, http.StatusInternalServerError) + return } - if err := i.node.DAG.Add(r.Context(), newnode); err != nil { - webError(w, "Could not add root node", err, http.StatusInternalServerError) + parent, ok := parentNode.(*mfs.Directory) + if !ok { + http.Error(w, "WritableGateway: parent is not a directory", http.StatusInternalServerError) return } - // Redirect to new path - ncid := newnode.Cid() - - i.addUserHeaders(w) // ok, _now_ write user's headers. - w.Header().Set("IPFS-Hash", ncid.String()) - http.Redirect(w, r, gopath.Join(ipfsPathPrefix+ncid.String(), path.Join(components[:len(components)-1])), http.StatusCreated) -} - -func (i *gatewayHandler) resolvePathComponents( - ctx context.Context, - c cid.Cid, - components []string, -) ([]ipld.Node, error) { - tctx, cancel := context.WithTimeout(ctx, time.Minute) - defer cancel() + // delete the file - rootnd, err := i.node.Resolver.DAG.Get(tctx, c) + err = parent.Unlink(filename) if err != nil { - return nil, fmt.Errorf("Could not resolve root object: %s", err) + webError(w, "WritableGateway: failed to remove file", err, http.StatusInternalServerError) + return } - pathNodes, err := i.node.Resolver.ResolveLinks(tctx, rootnd, components[:len(components)-1]) + nnode, err := root.GetDirectory().GetNode() if err != nil { - return nil, fmt.Errorf("Could not resolve parent object: %s", err) + webError(w, "WritableGateway: failed to finalize", err, http.StatusInternalServerError) } + ncid := nnode.Cid() - return pathNodes, nil + i.addUserHeaders(w) // ok, _now_ write user's headers. + w.Header().Set("IPFS-Hash", ncid.String()) + http.Redirect(w, r, gopath.Join(ipfsPathPrefix+ncid.String(), directory), http.StatusCreated) } func (i *gatewayHandler) addUserHeaders(w http.ResponseWriter) {