1package daemon
2
3import (
4 "bytes"
5 "context"
6 "errors"
7 "fmt"
8 "net"
9 "path/filepath"
10 "strings"
11 "sync"
12 "sync/atomic"
13 "time"
14
15 "github.com/charmbracelet/log/v2"
16 "github.com/charmbracelet/soft-serve/pkg/access"
17 "github.com/charmbracelet/soft-serve/pkg/backend"
18 "github.com/charmbracelet/soft-serve/pkg/config"
19 "github.com/charmbracelet/soft-serve/pkg/git"
20 "github.com/charmbracelet/soft-serve/pkg/utils"
21 "github.com/go-git/go-git/v5/plumbing/format/pktline"
22 "github.com/prometheus/client_golang/prometheus"
23 "github.com/prometheus/client_golang/prometheus/promauto"
24)
25
26var (
27 uploadPackGitCounter = promauto.NewCounterVec(prometheus.CounterOpts{
28 Namespace: "soft_serve",
29 Subsystem: "git",
30 Name: "git_upload_pack_total",
31 Help: "The total number of git-upload-pack requests",
32 }, []string{"repo"})
33
34 uploadArchiveGitCounter = promauto.NewCounterVec(prometheus.CounterOpts{
35 Namespace: "soft_serve",
36 Subsystem: "git",
37 Name: "git_upload_archive_total",
38 Help: "The total number of git-upload-archive requests",
39 }, []string{"repo"})
40)
41
42// ErrServerClosed indicates that the server has been closed.
43var ErrServerClosed = fmt.Errorf("git: %w", net.ErrClosed)
44
45// GitDaemon represents a Git daemon.
46type GitDaemon struct {
47 ctx context.Context
48 addr string
49 finished chan struct{}
50 conns connections
51 cfg *config.Config
52 be *backend.Backend
53 wg sync.WaitGroup
54 once sync.Once
55 logger *log.Logger
56 done atomic.Bool // indicates if the server has been closed
57 listeners []net.Listener
58 liMu sync.Mutex
59}
60
61// NewGitDaemon returns a new Git daemon.
62func NewGitDaemon(ctx context.Context) (*GitDaemon, error) {
63 cfg := config.FromContext(ctx)
64 addr := cfg.Git.ListenAddr
65 d := &GitDaemon{
66 ctx: ctx,
67 addr: addr,
68 finished: make(chan struct{}, 1),
69 cfg: cfg,
70 be: backend.FromContext(ctx),
71 conns: connections{m: make(map[net.Conn]struct{})},
72 logger: log.FromContext(ctx).WithPrefix("gitdaemon"),
73 }
74 return d, nil
75}
76
77// ListenAndServe starts the Git TCP daemon.
78func (d *GitDaemon) ListenAndServe() error {
79 if d.done.Load() {
80 return ErrServerClosed
81 }
82 listener, err := net.Listen("tcp", d.addr) //nolint:noctx
83 if err != nil {
84 return err //nolint:wrapcheck
85 }
86 return d.Serve(listener)
87}
88
89// Serve listens on the TCP network address and serves Git requests.
90func (d *GitDaemon) Serve(listener net.Listener) error {
91 if d.done.Load() {
92 return ErrServerClosed
93 }
94
95 d.wg.Add(1)
96 defer d.wg.Done()
97 d.liMu.Lock()
98 d.listeners = append(d.listeners, listener)
99 d.liMu.Unlock()
100
101 var tempDelay time.Duration
102 for {
103 conn, err := listener.Accept()
104 if err != nil { //nolint:nestif
105 select {
106 case <-d.finished:
107 return ErrServerClosed
108 default:
109 d.logger.Debugf("git: error accepting connection: %v", err)
110 }
111 if ne, ok := err.(net.Error); ok && ne.Temporary() { //nolint:staticcheck
112 if tempDelay == 0 {
113 tempDelay = 5 * time.Millisecond
114 } else {
115 tempDelay *= 2
116 }
117 if max := 1 * time.Second; tempDelay > max { //nolint:revive
118 tempDelay = max
119 }
120 time.Sleep(tempDelay)
121 continue
122 }
123 return err //nolint:wrapcheck
124 }
125
126 // Close connection if there are too many open connections.
127 if d.conns.Size()+1 >= d.cfg.Git.MaxConnections {
128 d.logger.Debugf("git: max connections reached, closing %s", conn.RemoteAddr())
129 d.fatal(conn, git.ErrMaxConnections)
130 continue
131 }
132
133 d.wg.Add(1)
134 go func() {
135 d.handleClient(conn)
136 d.wg.Done()
137 }()
138 }
139}
140
141func (d *GitDaemon) fatal(c net.Conn, err error) {
142 git.WritePktlineErr(c, err) //nolint:errcheck,gosec
143 if err := c.Close(); err != nil {
144 d.logger.Debugf("git: error closing connection: %v", err)
145 }
146}
147
148// handleClient handles a git protocol client.
149func (d *GitDaemon) handleClient(conn net.Conn) {
150 ctx, cancel := context.WithCancel(context.Background())
151 idleTimeout := time.Duration(d.cfg.Git.IdleTimeout) * time.Second
152 c := &serverConn{
153 Conn: conn,
154 idleTimeout: idleTimeout,
155 closeCanceler: cancel,
156 }
157 if d.cfg.Git.MaxTimeout > 0 {
158 dur := time.Duration(d.cfg.Git.MaxTimeout) * time.Second
159 c.maxDeadline = time.Now().Add(dur)
160 }
161 d.conns.Add(c)
162 defer func() {
163 d.conns.Close(c) //nolint:errcheck,gosec
164 }()
165
166 errc := make(chan error, 1)
167
168 s := pktline.NewScanner(c)
169 go func() {
170 if !s.Scan() {
171 if err := s.Err(); err != nil {
172 errc <- err
173 }
174 }
175 errc <- nil
176 }()
177
178 select {
179 case <-ctx.Done():
180 if err := ctx.Err(); err != nil {
181 d.logger.Debugf("git: connection context error: %v", err)
182 d.fatal(c, git.ErrTimeout)
183 }
184 return
185 case err := <-errc:
186 if nerr, ok := err.(net.Error); ok && nerr.Timeout() {
187 d.fatal(c, git.ErrTimeout)
188 return
189 } else if err != nil {
190 d.logger.Debugf("git: error scanning pktline: %v", err)
191 d.fatal(c, git.ErrSystemMalfunction)
192 return
193 }
194
195 line := s.Bytes()
196 split := bytes.SplitN(line, []byte{' '}, 2)
197 if len(split) != 2 {
198 d.fatal(c, git.ErrInvalidRequest)
199 return
200 }
201
202 var counter *prometheus.CounterVec
203 service := git.Service(split[0])
204 switch service { //nolint:exhaustive
205 case git.UploadPackService:
206 counter = uploadPackGitCounter
207 case git.UploadArchiveService:
208 counter = uploadArchiveGitCounter
209 default:
210 d.fatal(c, git.ErrInvalidRequest)
211 return
212 }
213
214 opts := bytes.SplitN(split[1], []byte{0}, 3)
215 if len(opts) < 2 {
216 d.fatal(c, git.ErrInvalidRequest)
217 return
218 }
219
220 host := strings.TrimPrefix(string(opts[1]), "host=")
221 extraParams := map[string]string{}
222
223 if len(opts) > 2 {
224 buf := bytes.TrimPrefix(opts[2], []byte{0})
225 for _, o := range bytes.Split(buf, []byte{0}) {
226 opt := string(o)
227 if opt == "" {
228 continue
229 }
230
231 kv := strings.SplitN(opt, "=", 2)
232 if len(kv) != 2 {
233 d.logger.Errorf("git: invalid option %q", opt)
234 continue
235 }
236
237 extraParams[kv[0]] = kv[1]
238 }
239
240 version := extraParams["version"]
241 if version != "" {
242 d.logger.Debugf("git: protocol version %s", version)
243 }
244 }
245
246 be := d.be
247 if !be.AllowKeyless(ctx) {
248 d.fatal(c, git.ErrNotAuthed)
249 return
250 }
251
252 name := utils.SanitizeRepo(string(opts[0]))
253 d.logger.Debugf("git: connect %s %s %s", c.RemoteAddr(), service, name)
254 defer d.logger.Debugf("git: disconnect %s %s %s", c.RemoteAddr(), service, name)
255
256 // git bare repositories should end in ".git"
257 // https://git-scm.com/docs/gitrepository-layout
258 repo := name + ".git"
259 reposDir := filepath.Join(d.cfg.DataPath, "repos")
260 if err := git.EnsureWithin(reposDir, repo); err != nil {
261 d.logger.Debugf("git: error ensuring repo path: %v", err)
262 d.fatal(c, git.ErrInvalidRepo)
263 return
264 }
265
266 if _, err := d.be.Repository(ctx, repo); err != nil {
267 d.fatal(c, git.ErrInvalidRepo)
268 return
269 }
270
271 auth := be.AccessLevel(ctx, name, "")
272 if auth < access.ReadOnlyAccess {
273 d.fatal(c, git.ErrNotAuthed)
274 return
275 }
276
277 // Environment variables to pass down to git hooks.
278 envs := []string{
279 "SOFT_SERVE_REPO_NAME=" + name,
280 "SOFT_SERVE_REPO_PATH=" + filepath.Join(reposDir, repo),
281 "SOFT_SERVE_HOST=" + host,
282 "SOFT_SERVE_LOG_PATH=" + filepath.Join(d.cfg.DataPath, "log", "hooks.log"),
283 }
284
285 // Add git protocol environment variable.
286 if len(extraParams) > 0 {
287 var gitProto string
288 for k, v := range extraParams {
289 if len(gitProto) > 0 {
290 gitProto += ":"
291 }
292 gitProto += k + "=" + v
293 }
294 envs = append(envs, "GIT_PROTOCOL="+gitProto)
295 }
296
297 envs = append(envs, d.cfg.Environ()...)
298
299 cmd := git.ServiceCommand{
300 Stdin: c,
301 Stdout: c,
302 Stderr: c,
303 Env: envs,
304 Dir: filepath.Join(reposDir, repo),
305 }
306
307 if err := service.Handler(ctx, cmd); err != nil {
308 d.logger.Debugf("git: error handling request: %v", err)
309 d.fatal(c, err)
310 return
311 }
312
313 counter.WithLabelValues(name)
314 }
315}
316
317// Close closes the underlying listener.
318func (d *GitDaemon) Close() error {
319 err := d.closeListener()
320 d.conns.CloseAll() //nolint:errcheck,gosec
321 return err
322}
323
324// closeListener closes the listener and the finished channel.
325func (d *GitDaemon) closeListener() error {
326 if d.done.Load() {
327 return ErrServerClosed
328 }
329 var err error
330 d.liMu.Lock()
331 for _, l := range d.listeners {
332 if err = l.Close(); err != nil {
333 err = errors.Join(err, fmt.Errorf("close listener %s: %w", l.Addr(), err))
334 }
335 }
336 d.listeners = d.listeners[:0]
337 d.liMu.Unlock()
338 d.once.Do(func() {
339 d.done.Store(true)
340 close(d.finished)
341 })
342 return err
343}
344
345// Shutdown gracefully shuts down the daemon.
346func (d *GitDaemon) Shutdown(ctx context.Context) error {
347 if d.done.Load() {
348 return ErrServerClosed
349 }
350
351 err := d.closeListener()
352 finished := make(chan struct{}, 1)
353 go func() {
354 defer close(finished)
355 d.wg.Wait()
356 }()
357 select {
358 case <-ctx.Done():
359 return ctx.Err() //nolint:wrapcheck
360 case <-finished:
361 return err
362 }
363}