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