1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 
18 #define GOTD_UNIX_SOCKET "/var/run/gotd.sock"
19 #define GOTD_UNIX_SOCKET_BACKLOG 10
20 #define GOTD_USER	"_gotd"
21 #define GOTD_CONF_PATH	"/etc/gotd.conf"
22 #define GOTD_EMPTY_PATH	"/var/empty"
23 
24 #ifndef GOT_LIBEXECDIR
25 #define GOT_LIBEXECDIR /usr/libexec
26 #endif
27 
28 #define GOTD_STRINGIFY(x) #x
29 #define GOTD_STRINGVAL(x) GOTD_STRINGIFY(x)
30 
31 #define GOTD_PROG_NOTIFY_EMAIL	got-notify-email
32 #define GOTD_PROG_NOTIFY_HTTP	got-notify-http
33 
34 #define GOTD_PATH_PROG_NOTIFY_EMAIL \
35 	GOTD_STRINGVAL(GOT_LIBEXECDIR) "/" \
36 	GOTD_STRINGVAL(GOTD_PROG_NOTIFY_EMAIL)
37 #define GOTD_PATH_PROG_NOTIFY_HTTP \
38 	GOTD_STRINGVAL(GOT_LIBEXECDIR) "/" \
39 	GOTD_STRINGVAL(GOTD_PROG_NOTIFY_HTTP)
40 
41 #define GOTD_MAXCLIENTS		1024
42 #define GOTD_MAX_CONN_PER_UID	4
43 #define GOTD_FD_RESERVE		5
44 #define GOTD_FD_NEEDED		6
45 #define GOTD_FILENO_MSG_PIPE	3
46 
47 #define GOTD_DEFAULT_REQUEST_TIMEOUT	3600
48 
49 /* Client hash tables need some extra room. */
50 #define GOTD_CLIENT_TABLE_SIZE (GOTD_MAXCLIENTS * 4)
51 
52 enum gotd_procid {
53 	PROC_GOTD	= 0,
54 	PROC_LISTEN,
55 	PROC_AUTH,
56 	PROC_SESSION_READ,
57 	PROC_SESSION_WRITE,
58 	PROC_REPO_READ,
59 	PROC_REPO_WRITE,
60 	PROC_GITWRAPPER,
61 	PROC_NOTIFY,
62 	PROC_MAX,
63 };
64 
65 struct gotd_imsgev {
66 	struct imsgbuf	 ibuf;
67 	void		(*handler)(int, short, void *);
68 	void		*handler_arg;
69 	struct event	 ev;
70 	short		 events;
71 };
72 
73 enum gotd_access {
74 	GOTD_ACCESS_PERMITTED = 1,
75 	GOTD_ACCESS_DENIED
76 };
77 
78 struct gotd_access_rule {
79 	STAILQ_ENTRY(gotd_access_rule) entry;
80 
81 	enum gotd_access access;
82 
83 	int authorization;
84 #define GOTD_AUTH_READ		0x1
85 #define GOTD_AUTH_WRITE		0x2
86 
87 	char *identifier;
88 };
89 STAILQ_HEAD(gotd_access_rule_list, gotd_access_rule);
90 
91 enum gotd_notification_target_type {
92 	GOTD_NOTIFICATION_VIA_EMAIL,
93 	GOTD_NOTIFICATION_VIA_HTTP
94 };
95 
96 struct gotd_notification_target {
97 	STAILQ_ENTRY(gotd_notification_target) entry;
98 
99 	enum gotd_notification_target_type type;
100 	union {
101 		struct {
102 			char *sender;
103 			char *recipient;
104 			char *responder;
105 			char *hostname;
106 			char *port;
107 		} email;
108 		struct {
109 			char *url;
110 			char *user;
111 			char *password;
112 		} http;
113 	} conf;
114 };
115 STAILQ_HEAD(gotd_notification_targets, gotd_notification_target);
116 
117 struct gotd_repo {
118 	TAILQ_ENTRY(gotd_repo)	 entry;
119 
120 	char name[NAME_MAX];
121 	char path[PATH_MAX];
122 
123 	struct gotd_access_rule_list rules;
124 	struct got_pathlist_head protected_tag_namespaces;
125 	struct got_pathlist_head protected_branch_namespaces;
126 	struct got_pathlist_head protected_branches;
127 
128 	struct got_pathlist_head notification_refs;
129 	struct got_pathlist_head notification_ref_namespaces;
130 	struct gotd_notification_targets notification_targets;
131 };
132 TAILQ_HEAD(gotd_repolist, gotd_repo);
133 
134 enum gotd_session_state {
135 	GOTD_STATE_EXPECT_LIST_REFS,
136 	GOTD_STATE_EXPECT_CAPABILITIES,
137 	GOTD_STATE_EXPECT_WANT,
138 	GOTD_STATE_EXPECT_REF_UPDATE,
139 	GOTD_STATE_EXPECT_MORE_REF_UPDATES,
140 	GOTD_STATE_EXPECT_HAVE,
141 	GOTD_STATE_EXPECT_PACKFILE,
142 	GOTD_STATE_EXPECT_DONE,
143 	GOTD_STATE_DONE,
144 	GOTD_STATE_NOTIFY,
145 };
146 
147 struct gotd_client_capability {
148 	char *key;
149 	char *value;
150 };
151 
152 struct gotd_object_id_array {
153 	struct got_object_id		**ids;
154 	size_t				 nalloc;
155 	size_t				 nids;
156 };
157 
158 struct gotd_uid_connection_limit {
159 	uid_t uid;
160 	int max_connections;
161 };
162 
163 struct gotd_child_proc;
164 
165 struct gotd {
166 	pid_t pid;
167 	char unix_socket_path[PATH_MAX];
168 	char user_name[32];
169 	struct gotd_repolist repos;
170 	int nrepos;
171 	struct gotd_child_proc *listen_proc;
172 	struct gotd_child_proc *notify_proc;
173 	int notifications_enabled;
174 	struct timeval request_timeout;
175 	struct timeval auth_timeout;
176 	struct gotd_uid_connection_limit *connection_limits;
177 	size_t nconnection_limits;
178 
179 	char *argv0;
180 	const char *confpath;
181 	int daemonize;
182 	int verbosity;
183 };
184 
185 enum gotd_imsg_type {
186 	/* An error occured while processing a request. */
187 	GOTD_IMSG_ERROR,
188 
189 	/* Commands used by gotctl(8). */
190 	GOTD_IMSG_INFO,
191 	GOTD_IMSG_INFO_REPO,
192 	GOTD_IMSG_INFO_CLIENT,
193 	GOTD_IMSG_STOP,
194 
195 	/* Request a list of references. */
196 	GOTD_IMSG_LIST_REFS,
197 	GOTD_IMSG_LIST_REFS_INTERNAL,
198 
199 	/* References. */
200 	GOTD_IMSG_REFLIST,
201 	GOTD_IMSG_REF,
202 	GOTD_IMSG_SYMREF,
203 
204 	/* Git protocol capabilities. */
205 	GOTD_IMSG_CAPABILITIES,
206 	GOTD_IMSG_CAPABILITY,
207 
208 	/* Git protocol chatter. */
209 	GOTD_IMSG_WANT,		/* The client wants an object. */
210 	GOTD_IMSG_HAVE,		/* The client has an object. */
211 	GOTD_IMSG_ACK,		/* The server has an object or a reference. */
212 	GOTD_IMSG_NAK,		/* The server does not have an object/ref. */
213 	GOTD_IMSG_REF_UPDATE,	/* The client wants to update a reference. */
214 	GOTD_IMSG_REF_DELETE,	/* The client wants to delete a reference. */
215 	GOTD_IMSG_FLUSH,	/* The client sent a flush packet. */
216 	GOTD_IMSG_DONE,		/* The client is done chatting. */
217 
218 	/* Sending or receiving a pack file. */
219 	GOTD_IMSG_SEND_PACKFILE, /* The server is sending a pack file. */
220 	GOTD_IMSG_RECV_PACKFILE, /* The server is receiving a pack file. */
221 	GOTD_IMSG_PACKIDX_FILE,  /* Temporary file handle for new pack index. */
222 	GOTD_IMSG_PACKFILE_PIPE, /* Pipe to send/receive a pack file stream. */
223 	GOTD_IMSG_PACKFILE_PROGRESS, /* Progress reporting. */
224 	GOTD_IMSG_PACKFILE_READY, /* Pack file is ready to be sent. */
225 	GOTD_IMSG_PACKFILE_STATUS, /* Received pack success/failure status. */
226 	GOTD_IMSG_PACKFILE_INSTALL, /* Received pack file can be installed. */
227 	GOTD_IMSG_PACKFILE_DONE, /* Pack file has been sent/received. */
228 
229 	/* Reference updates. */
230 	GOTD_IMSG_REF_UPDATES_START, /* Ref updates starting. */
231 	GOTD_IMSG_REF_UPDATE_OK, /* Update went OK. */
232 	GOTD_IMSG_REF_UPDATE_NG, /* Update was not good. */
233 	GOTD_IMSG_REFS_UPDATED, /* The server proccessed all ref updates. */
234 
235 	/* Client connections. */
236 	GOTD_IMSG_DISCONNECT,
237 	GOTD_IMSG_CONNECT,
238 
239 	/* Child process management. */
240 	GOTD_IMSG_CLIENT_SESSION_READY,
241 	GOTD_IMSG_REPO_CHILD_READY,
242 	GOTD_IMSG_CONNECT_REPO_CHILD,
243 
244 	/* Auth child process. */
245 	GOTD_IMSG_AUTHENTICATE,
246 	GOTD_IMSG_ACCESS_GRANTED,
247 
248 	/* Notify child process. */
249 	GOTD_IMSG_CONNECT_NOTIFIER,
250 	GOTD_IMSG_CONNECT_SESSION,
251 	GOTD_IMSG_NOTIFY,
252 	GOTD_IMSG_NOTIFICATION_SENT
253 };
254 
255 /* Structure for GOTD_IMSG_ERROR. */
256 struct gotd_imsg_error {
257 	int code; /* an error code from got_error.h */
258 	int errno_code; /* in case code equals GOT_ERR_ERRNO */
259 	uint32_t client_id;
260 	char msg[GOT_ERR_MAX_MSG_SIZE];
261 } __attribute__((__packed__));
262 
263 /* Structure for GOTD_IMSG_INFO. */
264 struct gotd_imsg_info {
265 	pid_t pid;
266 	int verbosity;
267 	int nrepos;
268 	int nclients;
269 
270 	/* Followed by nrepos GOTD_IMSG_INFO_REPO messages. */
271 	/* Followed by nclients GOTD_IMSG_INFO_CLIENT messages. */
272 };
273 
274 /* Structure for GOTD_IMSG_INFO_REPO. */
275 struct gotd_imsg_info_repo {
276 	char repo_name[NAME_MAX];
277 	char repo_path[PATH_MAX];
278 };
279 
280 /* Structure for GOTD_IMSG_INFO_CLIENT */
281 struct gotd_imsg_info_client {
282 	uid_t euid;
283 	gid_t egid;
284 	char repo_name[NAME_MAX];
285 	int is_writing;
286 	pid_t session_child_pid;
287 	pid_t repo_child_pid;
288 };
289 
290 /* Structure for GOTD_IMSG_LIST_REFS. */
291 struct gotd_imsg_list_refs {
292 	char repo_name[NAME_MAX];
293 	int client_is_reading; /* 1 if reading, 0 if writing */
294 };
295 
296 /* Structure for GOTD_IMSG_LIST_REFS_INTERNAL. */
297 struct gotd_imsg_list_refs_internal {
298 	uint32_t client_id;
299 };
300 
301 /* Structure for GOTD_IMSG_REFLIST. */
302 struct gotd_imsg_reflist {
303 	size_t nrefs;
304 
305 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
306 } __attribute__((__packed__));
307 
308 /* Structure for GOTD_IMSG_REF data. */
309 struct gotd_imsg_ref {
310 	uint8_t id[SHA1_DIGEST_LENGTH];
311 	size_t name_len;
312 	/* Followed by name_len data bytes. */
313 } __attribute__((__packed__));
314 
315 /* Structure for GOTD_IMSG_SYMREF data. */
316 struct gotd_imsg_symref {
317 	size_t name_len;
318 	size_t target_len;
319 	uint8_t target_id[SHA1_DIGEST_LENGTH];
320 
321 	/*
322 	 * Followed by name_len + target_len data bytes.
323 	 */
324 } __attribute__((__packed__));
325 
326 /* Structure for GOTD_IMSG_CAPABILITIES data. */
327 struct gotd_imsg_capabilities {
328 	size_t ncapabilities;
329 
330 	/*
331 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
332 	 */
333 } __attribute__((__packed__));
334 
335 /* Structure for GOTD_IMSG_CAPABILITY data. */
336 struct gotd_imsg_capability {
337 	size_t key_len;
338 	size_t value_len;
339 
340 	/*
341 	 * Followed by key_len + value_len data bytes.
342 	 */
343 } __attribute__((__packed__));
344 
345 /* Structure for GOTD_IMSG_WANT data. */
346 struct gotd_imsg_want {
347 	uint8_t object_id[SHA1_DIGEST_LENGTH];
348 	uint32_t client_id;
349 } __attribute__((__packed__));
350 
351 /* Structure for GOTD_IMSG_HAVE data. */
352 struct gotd_imsg_have {
353 	uint8_t object_id[SHA1_DIGEST_LENGTH];
354 	uint32_t client_id;
355 } __attribute__((__packed__));
356 
357 /* Structure for GOTD_IMSG_ACK data. */
358 struct gotd_imsg_ack {
359 	uint8_t object_id[SHA1_DIGEST_LENGTH];
360 	uint32_t client_id;
361 } __attribute__((__packed__));
362 
363 /* Structure for GOTD_IMSG_NAK data. */
364 struct gotd_imsg_nak {
365 	uint8_t object_id[SHA1_DIGEST_LENGTH];
366 	uint32_t client_id;
367 } __attribute__((__packed__));
368 
369 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
370 struct gotd_imsg_packfile_status {
371 	size_t reason_len;
372 
373 	/* Followed by reason_len data bytes. */
374 } __attribute__((__packed__));
375 
376 
377 /* Structure for GOTD_IMSG_REF_UPDATE data. */
378 struct gotd_imsg_ref_update {
379 	uint8_t old_id[SHA1_DIGEST_LENGTH];
380 	uint8_t new_id[SHA1_DIGEST_LENGTH];
381 	int ref_is_new;
382 	int delete_ref;
383 	uint32_t client_id;
384 	size_t name_len;
385 
386 	/* Followed by name_len data bytes. */
387 } __attribute__((__packed__));
388 
389 /* Structure for GOTD_IMSG_REF_UPDATES_START data. */
390 struct gotd_imsg_ref_updates_start {
391 	int nref_updates;
392 	uint32_t client_id;
393 
394 	/* Followed by nref_updates GOT_IMSG_REF_UPDATE_OK/NG messages. */
395 };
396 
397 /* Structure for GOTD_IMSG_REF_UPDATE_OK data. */
398 struct gotd_imsg_ref_update_ok {
399 	uint8_t old_id[SHA1_DIGEST_LENGTH];
400 	uint8_t new_id[SHA1_DIGEST_LENGTH];
401 	int ref_is_new;
402 	uint32_t client_id;
403 	size_t name_len;
404 
405 	/* Followed by name_len data bytes. */
406 } __attribute__((__packed__));
407 
408 /* Structure for GOTD_IMSG_REF_UPDATE_NG data. */
409 struct gotd_imsg_ref_update_ng {
410 	uint8_t old_id[SHA1_DIGEST_LENGTH];
411 	uint8_t new_id[SHA1_DIGEST_LENGTH];
412 	uint32_t client_id;
413 	size_t name_len;
414 	size_t reason_len;
415 
416 	/* Followed by name_len + reason_len data bytes. */
417 } __attribute__((__packed__));
418 
419 /* Structure for GOTD_IMSG_SEND_PACKFILE data. */
420 struct gotd_imsg_send_packfile {
421 	uint32_t client_id;
422 	int report_progress;
423 
424 	/* delta cache file is sent as a file descriptor */
425 
426 	/* followed by two GOTD_IMSG_PACKFILE_PIPE messages */
427 };
428 
429 /* Structure for GOTD_IMSG_RECV_PACKFILE data. */
430 struct gotd_imsg_recv_packfile {
431 	uint32_t client_id;
432 	int report_status;
433 
434 	/* pack destination temp file is sent as a file descriptor */
435 };
436 
437 /* Structure for GOTD_IMSG_PACKFILE_PIPE data. */
438 struct gotd_imsg_packfile_pipe {
439 	uint32_t client_id;
440 };
441 
442 /* Structure for GOTD_IMSG_PACKIDX_FILE data. */
443 struct gotd_imsg_packidx_file {
444 	uint32_t client_id;
445 };
446 
447 
448 /*
449  * Structure for GOTD_IMSG_PACKFILE_PROGRESS and
450  * GOTD_IMSG_PACKFILE_READY data.
451  */
452 struct gotd_imsg_packfile_progress {
453 	uint32_t client_id;
454 	int ncolored;
455 	int nfound;
456 	int ntrees;
457 	off_t packfile_size;
458 	int ncommits;
459 	int nobj_total;
460 	int nobj_deltify;
461 	int nobj_written;
462 };
463 
464 /* Structure for GOTD_IMSG_PACKFILE_INSTALL. */
465 struct gotd_imsg_packfile_install {
466 	uint32_t client_id;
467 	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
468 };
469 
470 /* Structure for GOTD_IMSG_PACKFILE_DONE data. */
471 struct gotd_imsg_packfile_done {
472 	uint32_t client_id;
473 };
474 
475 /* Structure for GOTD_IMSG_DISCONNECT data. */
476 struct gotd_imsg_disconnect {
477 	uint32_t client_id;
478 };
479 
480 /* Structure for GOTD_IMSG_CONNECT. */
481 struct gotd_imsg_connect {
482 	uint32_t client_id;
483 	uid_t euid;
484 	gid_t egid;
485 	size_t username_len;
486 
487 	/* Followed by username_len data bytes. */
488 };
489 
490 /* Structure for GOTD_IMSG_CONNECT_REPO_CHILD. */
491 struct gotd_imsg_connect_repo_child {
492 	uint32_t client_id;
493 	enum gotd_procid proc_id;
494 
495 	/* repo child imsg pipe is passed via imsg fd */
496 };
497 
498 /* Structure for GOTD_IMSG_AUTHENTICATE. */
499 struct gotd_imsg_auth {
500 	uid_t euid;
501 	gid_t egid;
502 	int required_auth;
503 	uint32_t client_id;
504 };
505 
506 /* Structures for GOTD_IMSG_NOTIFY. */
507 enum gotd_notification_action {
508 	GOTD_NOTIF_ACTION_CREATED,
509 	GOTD_NOTIF_ACTION_REMOVED,
510 	GOTD_NOTIF_ACTION_CHANGED
511 };
512 /* IMSG_NOTIFY session <-> repo_write */
513 struct gotd_imsg_notification_content {
514 	uint32_t client_id;
515 	enum gotd_notification_action action;
516 	uint8_t old_id[SHA1_DIGEST_LENGTH];
517 	uint8_t new_id[SHA1_DIGEST_LENGTH];
518 	size_t refname_len;
519 	/* Followed by refname_len data bytes. */
520 };
521 /* IMSG_NOTIFY session -> notify*/
522 struct gotd_imsg_notify {
523 	char repo_name[NAME_MAX];
524 	char subject_line[64];
525 };
526 
527 int parse_config(const char *, enum gotd_procid, struct gotd *);
528 struct gotd_repo *gotd_find_repo_by_name(const char *, struct gotd_repolist *);
529 struct gotd_repo *gotd_find_repo_by_path(const char *, struct gotd *);
530 struct gotd_uid_connection_limit *gotd_find_uid_connection_limit(
531     struct gotd_uid_connection_limit *limits, size_t nlimits, uid_t uid);
532 int gotd_parseuid(const char *s, uid_t *uid);
533 const struct got_error *gotd_parse_url(char **, char **, char **,
534     char **, const char *);
535 
536 /* imsg.c */
537 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
538 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
539 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
540     size_t);
541 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
542     struct imsg *imsg);
543 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
544     const struct got_error *);
545 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
546     const struct got_error *);
547 void gotd_imsg_event_add(struct gotd_imsgev *);
548 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
549     void *, uint16_t);
550 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
551 
552 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
553     uint32_t, pid_t);
554 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
555     uint32_t, pid_t);