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 #define GOTD_MAXCLIENTS		1024
25 #define GOTD_MAX_CONN_PER_UID	4
26 #define GOTD_FD_RESERVE		5
27 #define GOTD_FD_NEEDED		6
28 #define GOTD_FILENO_MSG_PIPE	3
29 
30 #define GOTD_DEFAULT_REQUEST_TIMEOUT	3600
31 
32 /* Client hash tables need some extra room. */
33 #define GOTD_CLIENT_TABLE_SIZE (GOTD_MAXCLIENTS * 4)
34 
35 enum gotd_procid {
36 	PROC_GOTD	= 0,
37 	PROC_LISTEN,
38 	PROC_AUTH,
39 	PROC_SESSION,
40 	PROC_REPO_READ,
41 	PROC_REPO_WRITE,
42 	PROC_MAX,
43 };
44 
45 struct gotd_imsgev {
46 	struct imsgbuf	 ibuf;
47 	void		(*handler)(int, short, void *);
48 	void		*handler_arg;
49 	struct event	 ev;
50 	short		 events;
51 };
52 
53 struct gotd_child_proc {
54 	pid_t pid;
55 	enum gotd_procid type;
56 	char repo_name[NAME_MAX];
57 	char repo_path[PATH_MAX];
58 	int pipe[2];
59 	struct gotd_imsgev iev;
60 	size_t nhelpers;
61 };
62 
63 enum gotd_access {
64 	GOTD_ACCESS_PERMITTED = 1,
65 	GOTD_ACCESS_DENIED
66 };
67 
68 struct gotd_access_rule {
69 	STAILQ_ENTRY(gotd_access_rule) entry;
70 
71 	enum gotd_access access;
72 
73 	int authorization;
74 #define GOTD_AUTH_READ		0x1
75 #define GOTD_AUTH_WRITE		0x2
76 
77 	char *identifier;
78 };
79 STAILQ_HEAD(gotd_access_rule_list, gotd_access_rule);
80 
81 struct gotd_repo {
82 	TAILQ_ENTRY(gotd_repo)	 entry;
83 
84 	char name[NAME_MAX];
85 	char path[PATH_MAX];
86 
87 	struct gotd_access_rule_list rules;
88 	struct got_pathlist_head protected_tag_namespaces;
89 	struct got_pathlist_head protected_branch_namespaces;
90 	struct got_pathlist_head protected_branches;
91 };
92 TAILQ_HEAD(gotd_repolist, gotd_repo);
93 
94 enum gotd_session_state {
95 	GOTD_STATE_EXPECT_LIST_REFS,
96 	GOTD_STATE_EXPECT_CAPABILITIES,
97 	GOTD_STATE_EXPECT_WANT,
98 	GOTD_STATE_EXPECT_REF_UPDATE,
99 	GOTD_STATE_EXPECT_MORE_REF_UPDATES,
100 	GOTD_STATE_EXPECT_HAVE,
101 	GOTD_STATE_EXPECT_PACKFILE,
102 	GOTD_STATE_EXPECT_DONE,
103 	GOTD_STATE_DONE,
104 };
105 
106 struct gotd_client_capability {
107 	char *key;
108 	char *value;
109 };
110 
111 struct gotd_object_id_array {
112 	struct got_object_id		**ids;
113 	size_t				 nalloc;
114 	size_t				 nids;
115 };
116 
117 struct gotd_uid_connection_limit {
118 	uid_t uid;
119 	int max_connections;
120 };
121 
122 struct gotd {
123 	pid_t pid;
124 	char unix_socket_path[PATH_MAX];
125 	char user_name[32];
126 	struct gotd_repolist repos;
127 	int nrepos;
128 	struct gotd_child_proc listen_proc;
129 	struct timeval request_timeout;
130 	struct timeval auth_timeout;
131 	struct gotd_uid_connection_limit *connection_limits;
132 	size_t nconnection_limits;
133 
134 	char *argv0;
135 	const char *confpath;
136 	int daemonize;
137 	int verbosity;
138 };
139 
140 enum gotd_imsg_type {
141 	/* An error occured while processing a request. */
142 	GOTD_IMSG_ERROR,
143 
144 	/* Commands used by gotctl(8). */
145 	GOTD_IMSG_INFO,
146 	GOTD_IMSG_INFO_REPO,
147 	GOTD_IMSG_INFO_CLIENT,
148 	GOTD_IMSG_STOP,
149 
150 	/* Request a list of references. */
151 	GOTD_IMSG_LIST_REFS,
152 	GOTD_IMSG_LIST_REFS_INTERNAL,
153 
154 	/* References. */
155 	GOTD_IMSG_REFLIST,
156 	GOTD_IMSG_REF,
157 	GOTD_IMSG_SYMREF,
158 
159 	/* Git protocol capabilities. */
160 	GOTD_IMSG_CAPABILITIES,
161 	GOTD_IMSG_CAPABILITY,
162 
163 	/* Git protocol chatter. */
164 	GOTD_IMSG_WANT,		/* The client wants an object. */
165 	GOTD_IMSG_HAVE,		/* The client has an object. */
166 	GOTD_IMSG_ACK,		/* The server has an object or a reference. */
167 	GOTD_IMSG_NAK,		/* The server does not have an object/ref. */
168 	GOTD_IMSG_REF_UPDATE,	/* The client wants to update a reference. */
169 	GOTD_IMSG_REF_DELETE,	/* The client wants to delete a reference. */
170 	GOTD_IMSG_FLUSH,	/* The client sent a flush packet. */
171 	GOTD_IMSG_DONE,		/* The client is done chatting. */
172 
173 	/* Sending or receiving a pack file. */
174 	GOTD_IMSG_SEND_PACKFILE, /* The server is sending a pack file. */
175 	GOTD_IMSG_RECV_PACKFILE, /* The server is receiving a pack file. */
176 	GOTD_IMSG_PACKIDX_FILE,  /* Temporary file handle for new pack index. */
177 	GOTD_IMSG_PACKFILE_PIPE, /* Pipe to send/receive a pack file stream. */
178 	GOTD_IMSG_PACKFILE_PROGRESS, /* Progress reporting. */
179 	GOTD_IMSG_PACKFILE_READY, /* Pack file is ready to be sent. */
180 	GOTD_IMSG_PACKFILE_STATUS, /* Received pack success/failure status. */
181 	GOTD_IMSG_PACKFILE_INSTALL, /* Received pack file can be installed. */
182 	GOTD_IMSG_PACKFILE_DONE, /* Pack file has been sent/received. */
183 
184 	/* Reference updates. */
185 	GOTD_IMSG_REF_UPDATES_START, /* Ref updates starting. */
186 	GOTD_IMSG_REF_UPDATE_OK, /* Update went OK. */
187 	GOTD_IMSG_REF_UPDATE_NG, /* Update was not good. */
188 	GOTD_IMSG_REFS_UPDATED, /* The server proccessed all ref updates. */
189 
190 	/* Client connections. */
191 	GOTD_IMSG_DISCONNECT,
192 	GOTD_IMSG_CONNECT,
193 
194 	/* Child process management. */
195 	GOTD_IMSG_CLIENT_SESSION_READY,
196 	GOTD_IMSG_REPO_CHILD_READY,
197 	GOTD_IMSG_CONNECT_REPO_CHILD,
198 
199 	/* Auth child process. */
200 	GOTD_IMSG_AUTHENTICATE,
201 	GOTD_IMSG_ACCESS_GRANTED,
202 };
203 
204 /* Structure for GOTD_IMSG_ERROR. */
205 struct gotd_imsg_error {
206 	int code; /* an error code from got_error.h */
207 	int errno_code; /* in case code equals GOT_ERR_ERRNO */
208 	uint32_t client_id;
209 	char msg[GOT_ERR_MAX_MSG_SIZE];
210 } __attribute__((__packed__));
211 
212 /* Structure for GOTD_IMSG_INFO. */
213 struct gotd_imsg_info {
214 	pid_t pid;
215 	int verbosity;
216 	int nrepos;
217 	int nclients;
218 
219 	/* Followed by nrepos GOTD_IMSG_INFO_REPO messages. */
220 	/* Followed by nclients GOTD_IMSG_INFO_CLIENT messages. */
221 };
222 
223 /* Structure for GOTD_IMSG_INFO_REPO. */
224 struct gotd_imsg_info_repo {
225 	char repo_name[NAME_MAX];
226 	char repo_path[PATH_MAX];
227 };
228 
229 /* Structure for GOTD_IMSG_INFO_CLIENT */
230 struct gotd_imsg_info_client {
231 	uid_t euid;
232 	gid_t egid;
233 	char repo_name[NAME_MAX];
234 	int is_writing;
235 	pid_t session_child_pid;
236 	pid_t repo_child_pid;
237 };
238 
239 /* Structure for GOTD_IMSG_LIST_REFS. */
240 struct gotd_imsg_list_refs {
241 	char repo_name[NAME_MAX];
242 	int client_is_reading; /* 1 if reading, 0 if writing */
243 };
244 
245 /* Structure for GOTD_IMSG_LIST_REFS_INTERNAL. */
246 struct gotd_imsg_list_refs_internal {
247 	uint32_t client_id;
248 };
249 
250 /* Structure for GOTD_IMSG_REFLIST. */
251 struct gotd_imsg_reflist {
252 	size_t nrefs;
253 
254 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
255 } __attribute__((__packed__));
256 
257 /* Structure for GOTD_IMSG_REF data. */
258 struct gotd_imsg_ref {
259 	uint8_t id[SHA1_DIGEST_LENGTH];
260 	size_t name_len;
261 	/* Followed by name_len data bytes. */
262 } __attribute__((__packed__));
263 
264 /* Structure for GOTD_IMSG_SYMREF data. */
265 struct gotd_imsg_symref {
266 	size_t name_len;
267 	size_t target_len;
268 	uint8_t target_id[SHA1_DIGEST_LENGTH];
269 
270 	/*
271 	 * Followed by name_len + target_len data bytes.
272 	 */
273 } __attribute__((__packed__));
274 
275 /* Structure for GOTD_IMSG_CAPABILITIES data. */
276 struct gotd_imsg_capabilities {
277 	size_t ncapabilities;
278 
279 	/*
280 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
281 	 */
282 } __attribute__((__packed__));
283 
284 /* Structure for GOTD_IMSG_CAPABILITY data. */
285 struct gotd_imsg_capability {
286 	size_t key_len;
287 	size_t value_len;
288 
289 	/*
290 	 * Followed by key_len + value_len data bytes.
291 	 */
292 } __attribute__((__packed__));
293 
294 /* Structure for GOTD_IMSG_WANT data. */
295 struct gotd_imsg_want {
296 	uint8_t object_id[SHA1_DIGEST_LENGTH];
297 	uint32_t client_id;
298 } __attribute__((__packed__));
299 
300 /* Structure for GOTD_IMSG_HAVE data. */
301 struct gotd_imsg_have {
302 	uint8_t object_id[SHA1_DIGEST_LENGTH];
303 	uint32_t client_id;
304 } __attribute__((__packed__));
305 
306 /* Structure for GOTD_IMSG_ACK data. */
307 struct gotd_imsg_ack {
308 	uint8_t object_id[SHA1_DIGEST_LENGTH];
309 	uint32_t client_id;
310 } __attribute__((__packed__));
311 
312 /* Structure for GOTD_IMSG_NAK data. */
313 struct gotd_imsg_nak {
314 	uint8_t object_id[SHA1_DIGEST_LENGTH];
315 	uint32_t client_id;
316 } __attribute__((__packed__));
317 
318 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
319 struct gotd_imsg_packfile_status {
320 	size_t reason_len;
321 
322 	/* Followed by reason_len data bytes. */
323 } __attribute__((__packed__));
324 
325 
326 /* Structure for GOTD_IMSG_REF_UPDATE data. */
327 struct gotd_imsg_ref_update {
328 	uint8_t old_id[SHA1_DIGEST_LENGTH];
329 	uint8_t new_id[SHA1_DIGEST_LENGTH];
330 	int ref_is_new;
331 	int delete_ref;
332 	uint32_t client_id;
333 	size_t name_len;
334 
335 	/* Followed by name_len data bytes. */
336 } __attribute__((__packed__));
337 
338 /* Structure for GOTD_IMSG_REF_UPDATES_START data. */
339 struct gotd_imsg_ref_updates_start {
340 	int nref_updates;
341 	uint32_t client_id;
342 
343 	/* Followed by nref_updates GOT_IMSG_REF_UPDATE_OK/NG messages. */
344 };
345 
346 /* Structure for GOTD_IMSG_REF_UPDATE_OK data. */
347 struct gotd_imsg_ref_update_ok {
348 	uint8_t old_id[SHA1_DIGEST_LENGTH];
349 	uint8_t new_id[SHA1_DIGEST_LENGTH];
350 	int ref_is_new;
351 	uint32_t client_id;
352 	size_t name_len;
353 
354 	/* Followed by name_len data bytes. */
355 } __attribute__((__packed__));
356 
357 /* Structure for GOTD_IMSG_REF_UPDATE_NG data. */
358 struct gotd_imsg_ref_update_ng {
359 	uint8_t old_id[SHA1_DIGEST_LENGTH];
360 	uint8_t new_id[SHA1_DIGEST_LENGTH];
361 	uint32_t client_id;
362 	size_t name_len;
363 	size_t reason_len;
364 
365 	/* Followed by name_len + reason_len data bytes. */
366 } __attribute__((__packed__));
367 
368 /* Structure for GOTD_IMSG_SEND_PACKFILE data. */
369 struct gotd_imsg_send_packfile {
370 	uint32_t client_id;
371 	int report_progress;
372 
373 	/* delta cache file is sent as a file descriptor */
374 
375 	/* followed by two GOTD_IMSG_PACKFILE_PIPE messages */
376 };
377 
378 /* Structure for GOTD_IMSG_RECV_PACKFILE data. */
379 struct gotd_imsg_recv_packfile {
380 	uint32_t client_id;
381 	int report_status;
382 
383 	/* pack destination temp file is sent as a file descriptor */
384 };
385 
386 /* Structure for GOTD_IMSG_PACKFILE_PIPE data. */
387 struct gotd_imsg_packfile_pipe {
388 	uint32_t client_id;
389 };
390 
391 /* Structure for GOTD_IMSG_PACKIDX_FILE data. */
392 struct gotd_imsg_packidx_file {
393 	uint32_t client_id;
394 };
395 
396 
397 /*
398  * Structure for GOTD_IMSG_PACKFILE_PROGRESS and
399  * GOTD_IMSG_PACKFILE_READY data.
400  */
401 struct gotd_imsg_packfile_progress {
402 	uint32_t client_id;
403 	int ncolored;
404 	int nfound;
405 	int ntrees;
406 	off_t packfile_size;
407 	int ncommits;
408 	int nobj_total;
409 	int nobj_deltify;
410 	int nobj_written;
411 };
412 
413 /* Structure for GOTD_IMSG_PACKFILE_INSTALL. */
414 struct gotd_imsg_packfile_install {
415 	uint32_t client_id;
416 	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
417 };
418 
419 /* Structure for GOTD_IMSG_PACKFILE_DONE data. */
420 struct gotd_imsg_packfile_done {
421 	uint32_t client_id;
422 };
423 
424 /* Structure for GOTD_IMSG_DISCONNECT data. */
425 struct gotd_imsg_disconnect {
426 	uint32_t client_id;
427 };
428 
429 /* Structure for GOTD_IMSG_CONNECT. */
430 struct gotd_imsg_connect {
431 	uint32_t client_id;
432 	uid_t euid;
433 	gid_t egid;
434 };
435 
436 /* Structure for GOTD_IMSG_CONNECT_REPO_CHILD. */
437 struct gotd_imsg_connect_repo_child {
438 	uint32_t client_id;
439 	enum gotd_procid proc_id;
440 
441 	/* repo child imsg pipe is passed via imsg fd */
442 };
443 
444 /* Structure for GOTD_IMSG_AUTHENTICATE. */
445 struct gotd_imsg_auth {
446 	uid_t euid;
447 	gid_t egid;
448 	int required_auth;
449 	uint32_t client_id;
450 };
451 
452 int parse_config(const char *, enum gotd_procid, struct gotd *, int);
453 struct gotd_repo *gotd_find_repo_by_name(const char *, struct gotd *);
454 struct gotd_repo *gotd_find_repo_by_path(const char *, struct gotd *);
455 struct gotd_uid_connection_limit *gotd_find_uid_connection_limit(
456     struct gotd_uid_connection_limit *limits, size_t nlimits, uid_t uid);
457 int gotd_parseuid(const char *s, uid_t *uid);
458 
459 /* imsg.c */
460 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
461 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
462 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
463     size_t);
464 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
465     struct imsg *imsg);
466 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
467     const struct got_error *);
468 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
469     const struct got_error *);
470 void gotd_imsg_event_add(struct gotd_imsgev *);
471 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
472     void *, uint16_t);
473 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
474 
475 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
476     uint32_t, pid_t);
477 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
478     uint32_t, pid_t);