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