jojo/cmd/forgejo/forgejo.go
Mathieu Fenniak f93d2cb261 ci: detect and prevent empty case statements in Go code (#11593)
One of the security patches released 2026-03-09 [fixed a vulnerability](https://codeberg.org/forgejo/forgejo/pulls/11513/commits/d1c7b04d09f6a13896eaa1322ac690b2021539da) caused by a misapplication of Go `case` statements, where the implementation would have been correct if Go `case` statements automatically fall through to the next case block, but they do not.  This PR adds a semgrep rule which detects any empty `case` statement and raises an error, in order to prevent this coding mistake in the future.

For example, code like this will now trigger a build error:
```go
	switch setting.Protocol {
	case setting.HTTPUnix:
	case setting.FCGI:
	case setting.FCGIUnix:
	default:
		defaultLocalURL := string(setting.Protocol) + "://"
	}
```

Example error:
```
    cmd/web.go
   ❯❯❱ semgrep.config.forgejo-switch-empty-case
          switch has a case block with no content. This is treated as "break" by Go, but developers may
          confuse it for "fallthrough".  To fix this error, disambiguate by using "break" or
          "fallthrough".

          279┆ switch setting.Protocol {
          280┆ case setting.HTTPUnix:
          281┆ case setting.FCGI:
          282┆ case setting.FCGIUnix:
          283┆ default:
          284┆   defaultLocalURL := string(setting.Protocol) + "://"
          285┆   if setting.HTTPAddr == "0.0.0.0" {
          286┆           defaultLocalURL += "localhost"
          287┆   } else {
          288┆           defaultLocalURL += setting.HTTPAddr
```

As described in the error output, this error can be fixed by explicitly listing `break` (the real Go behaviour, to do nothing in the block), or by listing `fallthrough` (if the intent was to fall through).

All existing code triggering this detection has been changed to `break` (or, rarely, irrelevant cases have been removed), which should maintain the same code functionality.  While performing this fixup, a light analysis was performed on each case and they *appeared* correct, but with ~65 cases I haven't gone into extreme depth.

Tests are present for the semgrep rule in `.semgrep/tests/go.go`.

## Checklist

The [contributor guide](https://forgejo.org/docs/next/contributor/) contains information that will be helpful to first time contributors. There also are a few [conditions for merging Pull Requests in Forgejo repositories](https://codeberg.org/forgejo/governance/src/branch/main/PullRequestsAgreement.md). You are also welcome to join the [Forgejo development chatroom](https://matrix.to/#/#forgejo-development:matrix.org).

### Documentation

- [ ] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
- [x] I did not document these changes and I do not expect someone else to do it.

### Release notes

- [ ] This change will be noticed by a Forgejo user or admin (feature, bug fix, performance, etc.). I suggest to include a release note for this change.
- [x] This change is not visible to a Forgejo user or admin (refactor, dependency upgrade, etc.). I think there is no need to add a release note for this change.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/11593
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: Mathieu Fenniak <mathieu@fenniak.net>
Co-committed-by: Mathieu Fenniak <mathieu@fenniak.net>
2026-03-10 02:50:28 +01:00

172 lines
4 KiB
Go

// Copyright The Forgejo Authors.
// SPDX-License-Identifier: MIT
package forgejo
import (
"context"
"fmt"
"io"
"os"
"os/signal"
"syscall"
"forgejo.org/models/db"
"forgejo.org/modules/log"
"forgejo.org/modules/private"
"forgejo.org/modules/setting"
"github.com/urfave/cli/v3"
)
type key int
const (
noInitKey key = iota + 1
noExitKey
stdoutKey
stderrKey
stdinKey
)
func CmdForgejo(ctx context.Context) *cli.Command {
return &cli.Command{
Name: "forgejo-cli",
Usage: "Forgejo CLI",
Flags: []cli.Flag{},
Commands: []*cli.Command{
CmdActions(ctx),
CmdF3(ctx),
},
}
}
func ContextSetNoInit(ctx context.Context, value bool) context.Context {
return context.WithValue(ctx, noInitKey, value)
}
func ContextGetNoInit(ctx context.Context) bool {
value, ok := ctx.Value(noInitKey).(bool)
return ok && value
}
func ContextSetNoExit(ctx context.Context, value bool) context.Context {
return context.WithValue(ctx, noExitKey, value)
}
func ContextGetNoExit(ctx context.Context) bool {
value, ok := ctx.Value(noExitKey).(bool)
return ok && value
}
func ContextSetStderr(ctx context.Context, value io.Writer) context.Context {
return context.WithValue(ctx, stderrKey, value)
}
func ContextGetStderr(ctx context.Context) io.Writer {
value, ok := ctx.Value(stderrKey).(io.Writer)
if !ok {
return os.Stderr
}
return value
}
func ContextSetStdout(ctx context.Context, value io.Writer) context.Context {
return context.WithValue(ctx, stdoutKey, value)
}
func ContextGetStdout(ctx context.Context) io.Writer {
value, ok := ctx.Value(stderrKey).(io.Writer)
if !ok {
return os.Stdout
}
return value
}
func ContextSetStdin(ctx context.Context, value io.Reader) context.Context {
return context.WithValue(ctx, stdinKey, value)
}
func ContextGetStdin(ctx context.Context) io.Reader {
value, ok := ctx.Value(stdinKey).(io.Reader)
if !ok {
return os.Stdin
}
return value
}
// copied from ../cmd.go
func initDB(ctx context.Context) error {
setting.MustInstalled()
setting.LoadDBSetting()
setting.InitSQLLoggersForCli(log.INFO)
if setting.Database.Type == "" {
log.Fatal(`Database settings are missing from the configuration file: %q.
Ensure you are running in the correct environment or set the correct configuration file with -c.
If this is the intended configuration file complete the [database] section.`, setting.CustomConf)
}
if err := db.InitEngine(ctx); err != nil {
return fmt.Errorf("unable to initialize the database using the configuration in %q. Error: %w", setting.CustomConf, err)
}
return nil
}
// copied from ../cmd.go
func installSignals(ctx context.Context) (context.Context, context.CancelFunc) {
ctx, cancel := context.WithCancel(ctx)
go func() {
// install notify
signalChannel := make(chan os.Signal, 1)
signal.Notify(
signalChannel,
syscall.SIGINT,
syscall.SIGTERM,
)
select {
case <-signalChannel:
break
case <-ctx.Done():
break
}
cancel()
signal.Reset()
}()
return ctx, cancel
}
func handleCliResponseExtra(ctx context.Context, extra private.ResponseExtra) error {
if false && extra.UserMsg != "" {
if _, err := fmt.Fprintf(ContextGetStdout(ctx), "%s", extra.UserMsg); err != nil {
panic(err)
}
}
if ContextGetNoExit(ctx) {
return extra.Error
}
return cli.Exit(extra.Error, 1)
}
func prepareWorkPathAndCustomConf(ctx context.Context) func(ctx context.Context, cli *cli.Command) (context.Context, error) {
return func(ctx context.Context, cli *cli.Command) (context.Context, error) {
if !ContextGetNoInit(ctx) {
var args setting.ArgWorkPathAndCustomConf
// from children to parent, check the global flags
for _, curCtx := range cli.Lineage() {
if curCtx.IsSet("work-path") && args.WorkPath == "" {
args.WorkPath = curCtx.String("work-path")
}
if curCtx.IsSet("custom-path") && args.CustomPath == "" {
args.CustomPath = curCtx.String("custom-path")
}
if curCtx.IsSet("config") && args.CustomConf == "" {
args.CustomConf = curCtx.String("config")
}
}
setting.InitWorkPathAndCommonConfig(os.Getenv, args)
}
return ctx, nil
}
}