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 struct gotd_client_capability {
135 	char *key;
136 	char *value;
137 };
138 
139 struct gotd_object_id_array {
140 	struct got_object_id		**ids;
141 	size_t				 nalloc;
142 	size_t				 nids;
143 };
144 
145 struct gotd_uid_connection_limit {
146 	uid_t uid;
147 	int max_connections;
148 };
149 
150 struct gotd_child_proc;
151 
152 struct gotd {
153 	pid_t pid;
154 	char unix_socket_path[PATH_MAX];
155 	char user_name[32];
156 	struct gotd_repolist repos;
157 	int nrepos;
158 	struct gotd_child_proc *listen_proc;
159 	struct gotd_child_proc *notify_proc;
160 	int notifications_enabled;
161 	struct timeval request_timeout;
162 	struct timeval auth_timeout;
163 	struct gotd_uid_connection_limit *connection_limits;
164 	size_t nconnection_limits;
165 
166 	char *argv0;
167 	const char *confpath;
168 	int daemonize;
169 	int verbosity;
170 };
171 
172 enum gotd_imsg_type {
173 	/* An error occured while processing a request. */
174 	GOTD_IMSG_ERROR,
175 
176 	/* Commands used by gotctl(8). */
177 	GOTD_IMSG_INFO,
178 	GOTD_IMSG_INFO_REPO,
179 	GOTD_IMSG_INFO_CLIENT,
180 	GOTD_IMSG_STOP,
181 
182 	/* Request a list of references. */
183 	GOTD_IMSG_LIST_REFS,
184 	GOTD_IMSG_LIST_REFS_INTERNAL,
185 
186 	/* References. */
187 	GOTD_IMSG_REFLIST,
188 	GOTD_IMSG_REF,
189 	GOTD_IMSG_SYMREF,
190 
191 	/* Git protocol capabilities. */
192 	GOTD_IMSG_CAPABILITIES,
193 	GOTD_IMSG_CAPABILITY,
194 
195 	/* Git protocol chatter. */
196 	GOTD_IMSG_WANT,		/* The client wants an object. */
197 	GOTD_IMSG_HAVE,		/* The client has an object. */
198 	GOTD_IMSG_ACK,		/* The server has an object or a reference. */
199 	GOTD_IMSG_NAK,		/* The server does not have an object/ref. */
200 	GOTD_IMSG_REF_UPDATE,	/* The client wants to update a reference. */
201 	GOTD_IMSG_REF_DELETE,	/* The client wants to delete a reference. */
202 	GOTD_IMSG_FLUSH,	/* The client sent a flush packet. */
203 	GOTD_IMSG_DONE,		/* The client is done chatting. */
204 
205 	/* Sending or receiving a pack file. */
206 	GOTD_IMSG_SEND_PACKFILE, /* The server is sending a pack file. */
207 	GOTD_IMSG_RECV_PACKFILE, /* The server is receiving a pack file. */
208 	GOTD_IMSG_PACKIDX_FILE,  /* Temporary file handle for new pack index. */
209 	GOTD_IMSG_PACKFILE_PIPE, /* Pipe to send/receive a pack file stream. */
210 	GOTD_IMSG_PACKFILE_PROGRESS, /* Progress reporting. */
211 	GOTD_IMSG_PACKFILE_READY, /* Pack file is ready to be sent. */
212 	GOTD_IMSG_PACKFILE_STATUS, /* Received pack success/failure status. */
213 	GOTD_IMSG_PACKFILE_INSTALL, /* Received pack file can be installed. */
214 	GOTD_IMSG_PACKFILE_DONE, /* Pack file has been sent/received. */
215 
216 	/* Reference updates. */
217 	GOTD_IMSG_REF_UPDATES_START, /* Ref updates starting. */
218 	GOTD_IMSG_REF_UPDATE_OK, /* Update went OK. */
219 	GOTD_IMSG_REF_UPDATE_NG, /* Update was not good. */
220 	GOTD_IMSG_REFS_UPDATED, /* The server proccessed all ref updates. */
221 
222 	/* Client connections. */
223 	GOTD_IMSG_DISCONNECT,
224 	GOTD_IMSG_CONNECT,
225 
226 	/* Child process management. */
227 	GOTD_IMSG_CLIENT_SESSION_READY,
228 	GOTD_IMSG_REPO_CHILD_READY,
229 	GOTD_IMSG_CONNECT_REPO_CHILD,
230 
231 	/* Auth child process. */
232 	GOTD_IMSG_AUTHENTICATE,
233 	GOTD_IMSG_ACCESS_GRANTED,
234 
235 	/* Notify child process. */
236 	GOTD_IMSG_CONNECT_NOTIFIER,
237 	GOTD_IMSG_CONNECT_SESSION,
238 	GOTD_IMSG_NOTIFY,
239 	GOTD_IMSG_NOTIFICATION_SENT
240 };
241 
242 /* Structure for GOTD_IMSG_ERROR. */
243 struct gotd_imsg_error {
244 	int code; /* an error code from got_error.h */
245 	int errno_code; /* in case code equals GOT_ERR_ERRNO */
246 	uint32_t client_id;
247 	char msg[GOT_ERR_MAX_MSG_SIZE];
248 } __attribute__((__packed__));
249 
250 /* Structure for GOTD_IMSG_INFO. */
251 struct gotd_imsg_info {
252 	pid_t pid;
253 	int verbosity;
254 	int nrepos;
255 	int nclients;
256 
257 	/* Followed by nrepos GOTD_IMSG_INFO_REPO messages. */
258 	/* Followed by nclients GOTD_IMSG_INFO_CLIENT messages. */
259 };
260 
261 /* Structure for GOTD_IMSG_INFO_REPO. */
262 struct gotd_imsg_info_repo {
263 	char repo_name[NAME_MAX];
264 	char repo_path[PATH_MAX];
265 };
266 
267 /* Structure for GOTD_IMSG_INFO_CLIENT */
268 struct gotd_imsg_info_client {
269 	uid_t euid;
270 	gid_t egid;
271 	char repo_name[NAME_MAX];
272 	int is_writing;
273 	pid_t session_child_pid;
274 	pid_t repo_child_pid;
275 };
276 
277 /* Structure for GOTD_IMSG_LIST_REFS. */
278 struct gotd_imsg_list_refs {
279 	char repo_name[NAME_MAX];
280 	int client_is_reading; /* 1 if reading, 0 if writing */
281 };
282 
283 /* Structure for GOTD_IMSG_REFLIST. */
284 struct gotd_imsg_reflist {
285 	size_t nrefs;
286 
287 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
288 } __attribute__((__packed__));
289 
290 /* Structure for GOTD_IMSG_REF data. */
291 struct gotd_imsg_ref {
292 	uint8_t id[SHA1_DIGEST_LENGTH];
293 	size_t name_len;
294 	/* Followed by name_len data bytes. */
295 } __attribute__((__packed__));
296 
297 /* Structure for GOTD_IMSG_SYMREF data. */
298 struct gotd_imsg_symref {
299 	size_t name_len;
300 	size_t target_len;
301 	uint8_t target_id[SHA1_DIGEST_LENGTH];
302 
303 	/*
304 	 * Followed by name_len + target_len data bytes.
305 	 */
306 } __attribute__((__packed__));
307 
308 /* Structure for GOTD_IMSG_CAPABILITIES data. */
309 struct gotd_imsg_capabilities {
310 	size_t ncapabilities;
311 
312 	/*
313 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
314 	 */
315 } __attribute__((__packed__));
316 
317 /* Structure for GOTD_IMSG_CAPABILITY data. */
318 struct gotd_imsg_capability {
319 	size_t key_len;
320 	size_t value_len;
321 
322 	/*
323 	 * Followed by key_len + value_len data bytes.
324 	 */
325 } __attribute__((__packed__));
326 
327 /* Structure for GOTD_IMSG_WANT data. */
328 struct gotd_imsg_want {
329 	uint8_t object_id[SHA1_DIGEST_LENGTH];
330 } __attribute__((__packed__));
331 
332 /* Structure for GOTD_IMSG_HAVE data. */
333 struct gotd_imsg_have {
334 	uint8_t object_id[SHA1_DIGEST_LENGTH];
335 } __attribute__((__packed__));
336 
337 /* Structure for GOTD_IMSG_ACK data. */
338 struct gotd_imsg_ack {
339 	uint8_t object_id[SHA1_DIGEST_LENGTH];
340 } __attribute__((__packed__));
341 
342 /* Structure for GOTD_IMSG_NAK data. */
343 struct gotd_imsg_nak {
344 	uint8_t object_id[SHA1_DIGEST_LENGTH];
345 } __attribute__((__packed__));
346 
347 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
348 struct gotd_imsg_packfile_status {
349 	size_t reason_len;
350 
351 	/* Followed by reason_len data bytes. */
352 } __attribute__((__packed__));
353 
354 
355 /* Structure for GOTD_IMSG_REF_UPDATE data. */
356 struct gotd_imsg_ref_update {
357 	uint8_t old_id[SHA1_DIGEST_LENGTH];
358 	uint8_t new_id[SHA1_DIGEST_LENGTH];
359 	int ref_is_new;
360 	int delete_ref;
361 	size_t name_len;
362 
363 	/* Followed by name_len data bytes. */
364 } __attribute__((__packed__));
365 
366 /* Structure for GOTD_IMSG_REF_UPDATES_START data. */
367 struct gotd_imsg_ref_updates_start {
368 	int nref_updates;
369 
370 	/* Followed by nref_updates GOT_IMSG_REF_UPDATE_OK/NG messages. */
371 };
372 
373 /* Structure for GOTD_IMSG_REF_UPDATE_OK data. */
374 struct gotd_imsg_ref_update_ok {
375 	uint8_t old_id[SHA1_DIGEST_LENGTH];
376 	uint8_t new_id[SHA1_DIGEST_LENGTH];
377 	int ref_is_new;
378 	size_t name_len;
379 
380 	/* Followed by name_len data bytes. */
381 } __attribute__((__packed__));
382 
383 /* Structure for GOTD_IMSG_REF_UPDATE_NG data. */
384 struct gotd_imsg_ref_update_ng {
385 	uint8_t old_id[SHA1_DIGEST_LENGTH];
386 	uint8_t new_id[SHA1_DIGEST_LENGTH];
387 	size_t name_len;
388 	size_t reason_len;
389 
390 	/* Followed by name_len + reason_len data bytes. */
391 } __attribute__((__packed__));
392 
393 /* Structure for GOTD_IMSG_SEND_PACKFILE data. */
394 struct gotd_imsg_send_packfile {
395 	int report_progress;
396 
397 	/* delta cache file is sent as a file descriptor */
398 
399 	/* followed by two GOTD_IMSG_PACKFILE_PIPE messages */
400 };
401 
402 /* Structure for GOTD_IMSG_RECV_PACKFILE data. */
403 struct gotd_imsg_recv_packfile {
404 	int report_status;
405 
406 	/* pack destination temp file is sent as a file descriptor */
407 };
408 
409 /*
410  * Structure for GOTD_IMSG_PACKFILE_PROGRESS and
411  * GOTD_IMSG_PACKFILE_READY data.
412  */
413 struct gotd_imsg_packfile_progress {
414 	int ncolored;
415 	int nfound;
416 	int ntrees;
417 	off_t packfile_size;
418 	int ncommits;
419 	int nobj_total;
420 	int nobj_deltify;
421 	int nobj_written;
422 };
423 
424 /* Structure for GOTD_IMSG_PACKFILE_INSTALL. */
425 struct gotd_imsg_packfile_install {
426 	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
427 };
428 
429 /* Structure for GOTD_IMSG_DISCONNECT data. */
430 struct gotd_imsg_disconnect {
431 	uint32_t client_id;
432 };
433 
434 /* Structure for GOTD_IMSG_CONNECT. */
435 struct gotd_imsg_connect {
436 	uint32_t client_id;
437 	uid_t euid;
438 	gid_t egid;
439 	size_t username_len;
440 
441 	/* Followed by username_len data bytes. */
442 };
443 
444 /* Structure for GOTD_IMSG_CONNECT_REPO_CHILD. */
445 struct gotd_imsg_connect_repo_child {
446 	enum gotd_procid proc_id;
447 
448 	/* repo child imsg pipe is passed via imsg fd */
449 };
450 
451 /* Structure for GOTD_IMSG_AUTHENTICATE. */
452 struct gotd_imsg_auth {
453 	uid_t euid;
454 	gid_t egid;
455 	int required_auth;
456 	uint32_t client_id;
457 };
458 
459 /* Structures for GOTD_IMSG_NOTIFY. */
460 enum gotd_notification_action {
461 	GOTD_NOTIF_ACTION_CREATED,
462 	GOTD_NOTIF_ACTION_REMOVED,
463 	GOTD_NOTIF_ACTION_CHANGED
464 };
465 /* IMSG_NOTIFY session <-> repo_write */
466 struct gotd_imsg_notification_content {
467 	enum gotd_notification_action action;
468 	uint8_t old_id[SHA1_DIGEST_LENGTH];
469 	uint8_t new_id[SHA1_DIGEST_LENGTH];
470 	size_t refname_len;
471 	/* Followed by refname_len data bytes. */
472 };
473 /* IMSG_NOTIFY session -> notify*/
474 struct gotd_imsg_notify {
475 	char repo_name[NAME_MAX];
476 	char subject_line[64];
477 };
478 
479 int parse_config(const char *, enum gotd_procid, struct gotd *);
480 struct gotd_repo *gotd_find_repo_by_name(const char *, struct gotd_repolist *);
481 struct gotd_repo *gotd_find_repo_by_path(const char *, struct gotd *);
482 struct gotd_uid_connection_limit *gotd_find_uid_connection_limit(
483     struct gotd_uid_connection_limit *limits, size_t nlimits, uid_t uid);
484 int gotd_parseuid(const char *s, uid_t *uid);
485 const struct got_error *gotd_parse_url(char **, char **, char **,
486     char **, const char *);
487 
488 /* imsg.c */
489 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
490 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
491 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
492     size_t);
493 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
494     struct imsg *imsg);
495 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
496     const struct got_error *);
497 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
498     const struct got_error *);
499 void gotd_imsg_event_add(struct gotd_imsgev *);
500 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
501     void *, uint16_t);
502 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
503 
504 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
505     uint32_t, pid_t);
506 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
507     uint32_t, pid_t);