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_session_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 	pid_t session_child_pid;
233 	pid_t repo_child_pid;
234 };
235 
236 /* Structure for GOTD_IMSG_LIST_REFS. */
237 struct gotd_imsg_list_refs {
238 	char repo_name[NAME_MAX];
239 	int client_is_reading; /* 1 if reading, 0 if writing */
240 };
241 
242 /* Structure for GOTD_IMSG_LIST_REFS_INTERNAL. */
243 struct gotd_imsg_list_refs_internal {
244 	uint32_t client_id;
245 };
246 
247 /* Structure for GOTD_IMSG_REFLIST. */
248 struct gotd_imsg_reflist {
249 	size_t nrefs;
250 
251 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
252 } __attribute__((__packed__));
253 
254 /* Structure for GOTD_IMSG_REF data. */
255 struct gotd_imsg_ref {
256 	uint8_t id[SHA1_DIGEST_LENGTH];
257 	size_t name_len;
258 	/* Followed by name_len data bytes. */
259 } __attribute__((__packed__));
260 
261 /* Structure for GOTD_IMSG_SYMREF data. */
262 struct gotd_imsg_symref {
263 	size_t name_len;
264 	size_t target_len;
265 	uint8_t target_id[SHA1_DIGEST_LENGTH];
266 
267 	/*
268 	 * Followed by name_len + target_len data bytes.
269 	 */
270 } __attribute__((__packed__));
271 
272 /* Structure for GOTD_IMSG_CAPABILITIES data. */
273 struct gotd_imsg_capabilities {
274 	size_t ncapabilities;
275 
276 	/*
277 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
278 	 */
279 } __attribute__((__packed__));
280 
281 /* Structure for GOTD_IMSG_CAPABILITY data. */
282 struct gotd_imsg_capability {
283 	size_t key_len;
284 	size_t value_len;
285 
286 	/*
287 	 * Followed by key_len + value_len data bytes.
288 	 */
289 } __attribute__((__packed__));
290 
291 /* Structure for GOTD_IMSG_WANT data. */
292 struct gotd_imsg_want {
293 	uint8_t object_id[SHA1_DIGEST_LENGTH];
294 	uint32_t client_id;
295 } __attribute__((__packed__));
296 
297 /* Structure for GOTD_IMSG_HAVE data. */
298 struct gotd_imsg_have {
299 	uint8_t object_id[SHA1_DIGEST_LENGTH];
300 	uint32_t client_id;
301 } __attribute__((__packed__));
302 
303 /* Structure for GOTD_IMSG_ACK data. */
304 struct gotd_imsg_ack {
305 	uint8_t object_id[SHA1_DIGEST_LENGTH];
306 	uint32_t client_id;
307 } __attribute__((__packed__));
308 
309 /* Structure for GOTD_IMSG_NAK data. */
310 struct gotd_imsg_nak {
311 	uint8_t object_id[SHA1_DIGEST_LENGTH];
312 	uint32_t client_id;
313 } __attribute__((__packed__));
314 
315 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
316 struct gotd_imsg_packfile_status {
317 	size_t reason_len;
318 
319 	/* Followed by reason_len data bytes. */
320 } __attribute__((__packed__));
321 
322 
323 /* Structure for GOTD_IMSG_REF_UPDATE data. */
324 struct gotd_imsg_ref_update {
325 	uint8_t old_id[SHA1_DIGEST_LENGTH];
326 	uint8_t new_id[SHA1_DIGEST_LENGTH];
327 	int ref_is_new;
328 	int delete_ref;
329 	uint32_t client_id;
330 	size_t name_len;
331 
332 	/* Followed by name_len data bytes. */
333 } __attribute__((__packed__));
334 
335 /* Structure for GOTD_IMSG_REF_UPDATES_START data. */
336 struct gotd_imsg_ref_updates_start {
337 	int nref_updates;
338 	uint32_t client_id;
339 
340 	/* Followed by nref_updates GOT_IMSG_REF_UPDATE_OK/NG messages. */
341 };
342 
343 /* Structure for GOTD_IMSG_REF_UPDATE_OK data. */
344 struct gotd_imsg_ref_update_ok {
345 	uint8_t old_id[SHA1_DIGEST_LENGTH];
346 	uint8_t new_id[SHA1_DIGEST_LENGTH];
347 	int ref_is_new;
348 	uint32_t client_id;
349 	size_t name_len;
350 
351 	/* Followed by name_len data bytes. */
352 } __attribute__((__packed__));
353 
354 /* Structure for GOTD_IMSG_REF_UPDATE_NG data. */
355 struct gotd_imsg_ref_update_ng {
356 	uint8_t old_id[SHA1_DIGEST_LENGTH];
357 	uint8_t new_id[SHA1_DIGEST_LENGTH];
358 	uint32_t client_id;
359 	size_t name_len;
360 	size_t reason_len;
361 
362 	/* Followed by name_len + reason_len data bytes. */
363 } __attribute__((__packed__));
364 
365 /* Structure for GOTD_IMSG_SEND_PACKFILE data. */
366 struct gotd_imsg_send_packfile {
367 	uint32_t client_id;
368 	int report_progress;
369 
370 	/* delta cache file is sent as a file descriptor */
371 
372 	/* followed by two GOTD_IMSG_PACKFILE_PIPE messages */
373 };
374 
375 /* Structure for GOTD_IMSG_RECV_PACKFILE data. */
376 struct gotd_imsg_recv_packfile {
377 	uint32_t client_id;
378 	int report_status;
379 
380 	/* pack destination temp file is sent as a file descriptor */
381 };
382 
383 /* Structure for GOTD_IMSG_PACKFILE_PIPE data. */
384 struct gotd_imsg_packfile_pipe {
385 	uint32_t client_id;
386 };
387 
388 /* Structure for GOTD_IMSG_PACKIDX_FILE data. */
389 struct gotd_imsg_packidx_file {
390 	uint32_t client_id;
391 };
392 
393 
394 /*
395  * Structure for GOTD_IMSG_PACKFILE_PROGRESS and
396  * GOTD_IMSG_PACKFILE_READY data.
397  */
398 struct gotd_imsg_packfile_progress {
399 	uint32_t client_id;
400 	int ncolored;
401 	int nfound;
402 	int ntrees;
403 	off_t packfile_size;
404 	int ncommits;
405 	int nobj_total;
406 	int nobj_deltify;
407 	int nobj_written;
408 };
409 
410 /* Structure for GOTD_IMSG_PACKFILE_INSTALL. */
411 struct gotd_imsg_packfile_install {
412 	uint32_t client_id;
413 	uint8_t pack_hash[SHA1_DIGEST_LENGTH];
414 };
415 
416 /* Structure for GOTD_IMSG_PACKFILE_DONE data. */
417 struct gotd_imsg_packfile_done {
418 	uint32_t client_id;
419 };
420 
421 /* Structure for GOTD_IMSG_DISCONNECT data. */
422 struct gotd_imsg_disconnect {
423 	uint32_t client_id;
424 };
425 
426 /* Structure for GOTD_IMSG_CONNECT. */
427 struct gotd_imsg_connect {
428 	uint32_t client_id;
429 	uid_t euid;
430 	gid_t egid;
431 };
432 
433 /* Structure for GOTD_IMSG_CONNECT_REPO_CHILD. */
434 struct gotd_imsg_connect_repo_child {
435 	uint32_t client_id;
436 	enum gotd_procid proc_id;
437 
438 	/* repo child imsg pipe is passed via imsg fd */
439 };
440 
441 /* Structure for GOTD_IMSG_AUTHENTICATE. */
442 struct gotd_imsg_auth {
443 	uid_t euid;
444 	gid_t egid;
445 	int required_auth;
446 	uint32_t client_id;
447 };
448 
449 int parse_config(const char *, enum gotd_procid, struct gotd *);
450 
451 /* imsg.c */
452 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
453 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
454 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
455     size_t);
456 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
457     struct imsg *imsg);
458 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
459     const struct got_error *);
460 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
461     const struct got_error *);
462 void gotd_imsg_event_add(struct gotd_imsgev *);
463 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
464     void *, uint16_t);
465 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
466 
467 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
468     uint32_t, pid_t);
469 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
470     uint32_t, pid_t);