From 1be4a24e9b009c0397b02a402b9938146f52ef0a Mon Sep 17 00:00:00 2001
From: Gianmaria Del Monte <39946305+gmgigi96@users.noreply.github.com>
Date: Mon, 25 Oct 2021 07:37:36 +0200
Subject: [PATCH] Filter root paths according to user agent (#2193)
---
changelog/unreleased/storage-ua-filtering.md | 7 +++
pkg/ctx/agentctx.go | 44 +++++++++++++++++++
pkg/storage/registry/static/static.go | 45 ++++++++++++++++++--
3 files changed, 93 insertions(+), 3 deletions(-)
create mode 100644 changelog/unreleased/storage-ua-filtering.md
create mode 100644 pkg/ctx/agentctx.go
diff --git a/changelog/unreleased/storage-ua-filtering.md b/changelog/unreleased/storage-ua-filtering.md
new file mode 100644
index 0000000000..61e7731a7a
--- /dev/null
+++ b/changelog/unreleased/storage-ua-filtering.md
@@ -0,0 +1,7 @@
+Enhancement: Filter root paths according to user agent
+
+Adds a new rule setting in the storage registry ("allowed_user_agents"),
+that allows a user to specify which storage provider shows according
+to the user agent that made the request.
+
+https://github.com/cs3org/reva/pull/2193
diff --git a/pkg/ctx/agentctx.go b/pkg/ctx/agentctx.go
new file mode 100644
index 0000000000..6b361676e1
--- /dev/null
+++ b/pkg/ctx/agentctx.go
@@ -0,0 +1,44 @@
+// Copyright 2018-2021 CERN
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+package ctx
+
+import (
+ "context"
+
+ ua "github.com/mileusna/useragent"
+ "google.golang.org/grpc/metadata"
+)
+
+// ContextGetUserAgent returns the user agent if set in the given context.
+// see https://github.com/grpc/grpc-go/issues/1100
+func ContextGetUserAgent(ctx context.Context) (*ua.UserAgent, bool) {
+ md, ok := metadata.FromIncomingContext(ctx)
+ if !ok {
+ return nil, false
+ }
+ userAgentLst, ok := md["user-agent"]
+ if !ok {
+ return nil, false
+ }
+ if len(userAgentLst) == 0 {
+ return nil, false
+ }
+ userAgent := ua.Parse(userAgentLst[0])
+ return &userAgent, true
+}
diff --git a/pkg/storage/registry/static/static.go b/pkg/storage/registry/static/static.go
index 58d3845013..d5d84403e4 100644
--- a/pkg/storage/registry/static/static.go
+++ b/pkg/storage/registry/static/static.go
@@ -32,6 +32,7 @@ import (
"github.com/cs3org/reva/pkg/storage"
"github.com/cs3org/reva/pkg/storage/registry/registry"
"github.com/cs3org/reva/pkg/storage/utils/templates"
+ ua "github.com/mileusna/useragent"
"github.com/mitchellh/mapstructure"
"github.com/pkg/errors"
)
@@ -43,9 +44,10 @@ func init() {
var bracketRegex = regexp.MustCompile(`\[(.*?)\]`)
type rule struct {
- Mapping string `mapstructure:"mapping"`
- Address string `mapstructure:"address"`
- Aliases map[string]string `mapstructure:"aliases"`
+ Mapping string `mapstructure:"mapping"`
+ Address string `mapstructure:"address"`
+ Aliases map[string]string `mapstructure:"aliases"`
+ AllowedUserAgents []string `mapstructure:"allowed_user_agents"`
}
type config struct {
@@ -138,6 +140,27 @@ func (b *reg) GetHome(ctx context.Context) (*registrypb.ProviderInfo, error) {
return nil, errors.New("static: home not found")
}
+func userAgentIsAllowed(ua *ua.UserAgent, userAgents []string) bool {
+ for _, userAgent := range userAgents {
+ switch userAgent {
+ case "web":
+ if ua.IsChrome() || ua.IsEdge() || ua.IsFirefox() || ua.IsSafari() ||
+ ua.IsInternetExplorer() || ua.IsOpera() || ua.IsOperaMini() {
+ return true
+ }
+ case "desktop":
+ if ua.Desktop {
+ return true
+ }
+ case "grpc":
+ if strings.HasPrefix(ua.Name, "grpc") {
+ return true
+ }
+ }
+ }
+ return false
+}
+
func (b *reg) FindProviders(ctx context.Context, ref *provider.Reference) ([]*registrypb.ProviderInfo, error) {
// find longest match
var match *registrypb.ProviderInfo
@@ -173,6 +196,22 @@ func (b *reg) FindProviders(ctx context.Context, ref *provider.Reference) ([]*re
fn := path.Clean(ref.GetPath())
if fn != "" {
for prefix, rule := range b.c.Rules {
+
+ // check if the provider is allowed to be shown according to the
+ // user agent that made the request
+ // if the list of AllowedUserAgents is empty, this means that
+ // every agents that made the request could see the provider
+
+ if len(rule.AllowedUserAgents) != 0 {
+ ua, ok := ctxpkg.ContextGetUserAgent(ctx)
+ if !ok {
+ continue
+ }
+ if !userAgentIsAllowed(ua, rule.AllowedUserAgents) {
+ continue // skip this provider
+ }
+ }
+
addr := getProviderAddr(ctx, rule)
r, err := regexp.Compile("^" + prefix)
if err != nil {