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 };
89 TAILQ_HEAD(gotd_repolist, gotd_repo);
90 
91 enum gotd_client_state {
92 	GOTD_STATE_EXPECT_LIST_REFS,
93 	GOTD_STATE_EXPECT_CAPABILITIES,
94 	GOTD_STATE_EXPECT_WANT,
95 	GOTD_STATE_EXPECT_REF_UPDATE,
96 	GOTD_STATE_EXPECT_MORE_REF_UPDATES,
97 	GOTD_STATE_EXPECT_HAVE,
98 	GOTD_STATE_EXPECT_PACKFILE,
99 	GOTD_STATE_EXPECT_DONE,
100 	GOTD_STATE_DONE,
101 };
102 
103 struct gotd_client_capability {
104 	char *key;
105 	char *value;
106 };
107 
108 struct gotd_object_id_array {
109 	struct got_object_id		**ids;
110 	size_t				 nalloc;
111 	size_t				 nids;
112 };
113 
114 struct gotd_uid_connection_limit {
115 	uid_t uid;
116 	int max_connections;
117 };
118 
119 struct gotd {
120 	pid_t pid;
121 	char unix_socket_path[PATH_MAX];
122 	char user_name[32];
123 	struct gotd_repolist repos;
124 	int nrepos;
125 	struct gotd_child_proc listen_proc;
126 	struct timeval request_timeout;
127 	struct timeval auth_timeout;
128 	struct gotd_uid_connection_limit *connection_limits;
129 	size_t nconnection_limits;
130 
131 	char *argv0;
132 	const char *confpath;
133 	int daemonize;
134 	int verbosity;
135 };
136 
137 enum gotd_imsg_type {
138 	/* An error occured while processing a request. */
139 	GOTD_IMSG_ERROR,
140 
141 	/* Commands used by gotctl(8). */
142 	GOTD_IMSG_INFO,
143 	GOTD_IMSG_INFO_REPO,
144 	GOTD_IMSG_INFO_CLIENT,
145 	GOTD_IMSG_STOP,
146 
147 	/* Request a list of references. */
148 	GOTD_IMSG_LIST_REFS,
149 	GOTD_IMSG_LIST_REFS_INTERNAL,
150 
151 	/* References. */
152 	GOTD_IMSG_REFLIST,
153 	GOTD_IMSG_REF,
154 	GOTD_IMSG_SYMREF,
155 
156 	/* Git protocol capabilities. */
157 	GOTD_IMSG_CAPABILITIES,
158 	GOTD_IMSG_CAPABILITY,
159 
160 	/* Git protocol chatter. */
161 	GOTD_IMSG_WANT,		/* The client wants an object. */
162 	GOTD_IMSG_HAVE,		/* The client has an object. */
163 	GOTD_IMSG_ACK,		/* The server has an object or a reference. */
164 	GOTD_IMSG_NAK,		/* The server does not have an object/ref. */
165 	GOTD_IMSG_REF_UPDATE,	/* The client wants to update a reference. */
166 	GOTD_IMSG_REF_DELETE,	/* The client wants to delete a reference. */
167 	GOTD_IMSG_FLUSH,	/* The client sent a flush packet. */
168 	GOTD_IMSG_DONE,		/* The client is done chatting. */
169 
170 	/* Sending or receiving a pack file. */
171 	GOTD_IMSG_SEND_PACKFILE, /* The server is sending a pack file. */
172 	GOTD_IMSG_RECV_PACKFILE, /* The server is receiving a pack file. */
173 	GOTD_IMSG_PACKIDX_FILE,  /* Temporary file handle for new pack index. */
174 	GOTD_IMSG_PACKFILE_PIPE, /* Pipe to send/receive a pack file stream. */
175 	GOTD_IMSG_PACKFILE_PROGRESS, /* Progress reporting. */
176 	GOTD_IMSG_PACKFILE_READY, /* Pack file is ready to be sent. */
177 	GOTD_IMSG_PACKFILE_STATUS, /* Received pack success/failure status. */
178 	GOTD_IMSG_PACKFILE_INSTALL, /* Received pack file can be installed. */
179 	GOTD_IMSG_PACKFILE_DONE, /* Pack file has been sent/received. */
180 
181 	/* Reference updates. */
182 	GOTD_IMSG_REF_UPDATES_START, /* Ref updates starting. */
183 	GOTD_IMSG_REF_UPDATE_OK, /* Update went OK. */
184 	GOTD_IMSG_REF_UPDATE_NG, /* Update was not good. */
185 	GOTD_IMSG_REFS_UPDATED, /* The server proccessed all ref updates. */
186 
187 	/* Client connections. */
188 	GOTD_IMSG_DISCONNECT,
189 	GOTD_IMSG_CONNECT,
190 
191 	/* Child process management. */
192 	GOTD_IMSG_CLIENT_SESSION_READY,
193 	GOTD_IMSG_REPO_CHILD_READY,
194 	GOTD_IMSG_CONNECT_REPO_CHILD,
195 
196 	/* Auth child process. */
197 	GOTD_IMSG_AUTHENTICATE,
198 	GOTD_IMSG_ACCESS_GRANTED,
199 };
200 
201 /* Structure for GOTD_IMSG_ERROR. */
202 struct gotd_imsg_error {
203 	int code; /* an error code from got_error.h */
204 	int errno_code; /* in case code equals GOT_ERR_ERRNO */
205 	uint32_t client_id;
206 	char msg[GOT_ERR_MAX_MSG_SIZE];
207 } __attribute__((__packed__));
208 
209 /* Structure for GOTD_IMSG_INFO. */
210 struct gotd_imsg_info {
211 	pid_t pid;
212 	int verbosity;
213 	int nrepos;
214 	int nclients;
215 
216 	/* Followed by nrepos GOTD_IMSG_INFO_REPO messages. */
217 	/* Followed by nclients GOTD_IMSG_INFO_CLIENT messages. */
218 };
219 
220 /* Structure for GOTD_IMSG_INFO_REPO. */
221 struct gotd_imsg_info_repo {
222 	char repo_name[NAME_MAX];
223 	char repo_path[PATH_MAX];
224 };
225 
226 /* Structure for GOTD_IMSG_INFO_CLIENT */
227 struct gotd_imsg_info_client {
228 	uid_t euid;
229 	gid_t egid;
230 	char repo_name[NAME_MAX];
231 	int is_writing;
232 	enum gotd_client_state state;
233 	pid_t session_child_pid;
234 	pid_t repo_child_pid;
235 	size_t ncapabilities;
236 
237 	/* Followed by ncapabilities GOTD_IMSG_CAPABILITY. */
238 };
239 
240 /* Structure for GOTD_IMSG_LIST_REFS. */
241 struct gotd_imsg_list_refs {
242 	char repo_name[NAME_MAX];
243 	int client_is_reading; /* 1 if reading, 0 if writing */
244 };
245 
246 /* Structure for GOTD_IMSG_LIST_REFS_INTERNAL. */
247 struct gotd_imsg_list_refs_internal {
248 	uint32_t client_id;
249 };
250 
251 /* Structure for GOTD_IMSG_REFLIST. */
252 struct gotd_imsg_reflist {
253 	size_t nrefs;
254 
255 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
256 } __attribute__((__packed__));
257 
258 /* Structure for GOTD_IMSG_REF data. */
259 struct gotd_imsg_ref {
260 	uint8_t id[SHA1_DIGEST_LENGTH];
261 	size_t name_len;
262 	/* Followed by name_len data bytes. */
263 } __attribute__((__packed__));
264 
265 /* Structure for GOTD_IMSG_SYMREF data. */
266 struct gotd_imsg_symref {
267 	size_t name_len;
268 	size_t target_len;
269 	uint8_t target_id[SHA1_DIGEST_LENGTH];
270 
271 	/*
272 	 * Followed by name_len + target_len data bytes.
273 	 */
274 } __attribute__((__packed__));
275 
276 /* Structure for GOTD_IMSG_CAPABILITIES data. */
277 struct gotd_imsg_capabilities {
278 	size_t ncapabilities;
279 
280 	/*
281 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
282 	 */
283 } __attribute__((__packed__));
284 
285 /* Structure for GOTD_IMSG_CAPABILITY data. */
286 struct gotd_imsg_capability {
287 	size_t key_len;
288 	size_t value_len;
289 
290 	/*
291 	 * Followed by key_len + value_len data bytes.
292 	 */
293 } __attribute__((__packed__));
294 
295 /* Structure for GOTD_IMSG_WANT data. */
296 struct gotd_imsg_want {
297 	uint8_t object_id[SHA1_DIGEST_LENGTH];
298 	uint32_t client_id;
299 } __attribute__((__packed__));
300 
301 /* Structure for GOTD_IMSG_HAVE data. */
302 struct gotd_imsg_have {
303 	uint8_t object_id[SHA1_DIGEST_LENGTH];
304 	uint32_t client_id;
305 } __attribute__((__packed__));
306 
307 /* Structure for GOTD_IMSG_ACK data. */
308 struct gotd_imsg_ack {
309 	uint8_t object_id[SHA1_DIGEST_LENGTH];
310 	uint32_t client_id;
311 } __attribute__((__packed__));
312 
313 /* Structure for GOTD_IMSG_NAK data. */
314 struct gotd_imsg_nak {
315 	uint8_t object_id[SHA1_DIGEST_LENGTH];
316 	uint32_t client_id;
317 } __attribute__((__packed__));
318 
319 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
320 struct gotd_imsg_packfile_status {
321 	size_t reason_len;
322 
323 	/* Followed by reason_len data bytes. */
324 } __attribute__((__packed__));
325 
326 
327 /* Structure for GOTD_IMSG_REF_UPDATE data. */
328 struct gotd_imsg_ref_update {
329 	uint8_t old_id[SHA1_DIGEST_LENGTH];
330 	uint8_t new_id[SHA1_DIGEST_LENGTH];
331 	int ref_is_new;
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 *);
453 
454 /* imsg.c */
455 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
456 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
457 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
458     size_t);
459 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
460     struct imsg *imsg);
461 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
462     const struct got_error *);
463 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
464     const struct got_error *);
465 void gotd_imsg_event_add(struct gotd_imsgev *);
466 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
467     void *, uint16_t);
468 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
469 
470 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
471     uint32_t, pid_t);
472 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
473     uint32_t, pid_t);