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 log "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// NewDaemon 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)
83 if err != nil {
84 return err
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 {
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
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)
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)
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 {
205 case git.UploadPackService:
206 counter = uploadPackGitCounter
207 case git.UploadArchiveService:
208 counter = uploadArchiveGitCounter
209 case git.ReceivePackService, git.LFSTransferService:
210 // These services don't have counters in this context
211 d.fatal(c, git.ErrInvalidRequest)
212 return
213 default:
214 d.fatal(c, git.ErrInvalidRequest)
215 return
216 }
217
218 opts := bytes.SplitN(split[1], []byte{0}, 3)
219 if len(opts) < 2 {
220 d.fatal(c, git.ErrInvalidRequest)
221 return
222 }
223
224 host := strings.TrimPrefix(string(opts[1]), "host=")
225 extraParams := map[string]string{}
226
227 if len(opts) > 2 {
228 buf := bytes.TrimPrefix(opts[2], []byte{0})
229 for _, o := range bytes.Split(buf, []byte{0}) {
230 opt := string(o)
231 if opt == "" {
232 continue
233 }
234
235 kv := strings.SplitN(opt, "=", 2)
236 if len(kv) != 2 {
237 d.logger.Errorf("git: invalid option %q", opt)
238 continue
239 }
240
241 extraParams[kv[0]] = kv[1]
242 }
243
244 version := extraParams["version"]
245 if version != "" {
246 d.logger.Debugf("git: protocol version %s", version)
247 }
248 }
249
250 be := d.be
251 if !be.AllowKeyless(ctx) {
252 d.fatal(c, git.ErrNotAuthed)
253 return
254 }
255
256 name := utils.SanitizeRepo(string(opts[0]))
257 d.logger.Debugf("git: connect %s %s %s", c.RemoteAddr(), service, name)
258 defer d.logger.Debugf("git: disconnect %s %s %s", c.RemoteAddr(), service, name)
259
260 // git bare repositories should end in ".git"
261 // https://git-scm.com/docs/gitrepository-layout
262 repo := name + ".git"
263 reposDir := filepath.Join(d.cfg.DataPath, "repos")
264 if err := git.EnsureWithin(reposDir, repo); err != nil {
265 d.logger.Debugf("git: error ensuring repo path: %v", err)
266 d.fatal(c, git.ErrInvalidRepo)
267 return
268 }
269
270 if _, err := d.be.Repository(ctx, repo); err != nil {
271 d.fatal(c, git.ErrInvalidRepo)
272 return
273 }
274
275 auth := be.AccessLevel(ctx, name, "")
276 if auth < access.ReadOnlyAccess {
277 d.fatal(c, git.ErrNotAuthed)
278 return
279 }
280
281 // Environment variables to pass down to git hooks.
282 envs := []string{
283 "SOFT_SERVE_REPO_NAME=" + name,
284 "SOFT_SERVE_REPO_PATH=" + filepath.Join(reposDir, repo),
285 "SOFT_SERVE_HOST=" + host,
286 "SOFT_SERVE_LOG_PATH=" + filepath.Join(d.cfg.DataPath, "log", "hooks.log"),
287 }
288
289 // Add git protocol environment variable.
290 if len(extraParams) > 0 {
291 var gitProto string
292 for k, v := range extraParams {
293 if len(gitProto) > 0 {
294 gitProto += ":"
295 }
296 gitProto += k + "=" + v
297 }
298 envs = append(envs, "GIT_PROTOCOL="+gitProto)
299 }
300
301 envs = append(envs, d.cfg.Environ()...)
302
303 cmd := git.ServiceCommand{
304 Stdin: c,
305 Stdout: c,
306 Stderr: c,
307 Env: envs,
308 Dir: filepath.Join(reposDir, repo),
309 }
310
311 if err := service.Handler(ctx, cmd); err != nil {
312 d.logger.Debugf("git: error handling request: %v", err)
313 d.fatal(c, err)
314 return
315 }
316
317 counter.WithLabelValues(name)
318 }
319}
320
321// Close closes the underlying listener.
322func (d *GitDaemon) Close() error {
323 err := d.closeListener()
324 d.conns.CloseAll()
325 return err
326}
327
328// closeListener closes the listener and the finished channel.
329func (d *GitDaemon) closeListener() error {
330 if d.done.Load() {
331 return ErrServerClosed
332 }
333 var err error
334 d.liMu.Lock()
335 for _, l := range d.listeners {
336 if err = l.Close(); err != nil {
337 err = errors.Join(err, fmt.Errorf("close listener %s: %w", l.Addr(), err))
338 }
339 }
340 d.listeners = d.listeners[:0]
341 d.liMu.Unlock()
342 d.once.Do(func() {
343 d.done.Store(true)
344 close(d.finished)
345 })
346 return err
347}
348
349// Shutdown gracefully shuts down the daemon.
350func (d *GitDaemon) Shutdown(ctx context.Context) error {
351 if d.done.Load() {
352 return ErrServerClosed
353 }
354
355 err := d.closeListener()
356 finished := make(chan struct{}, 1)
357 go func() {
358 defer close(finished)
359 d.wg.Wait()
360 }()
361 select {
362 case <-ctx.Done():
363 return ctx.Err()
364 case <-finished:
365 return err
366 }
367}