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_UNIX_GROUP	"_gotsh"
21 #define GOTD_USER	"_gotd"
22 #define GOTD_CONF_PATH	"/etc/gotd.conf"
23 #define GOTD_EMPTY_PATH	"/var/empty"
24 
25 #define GOTD_MAXCLIENTS		1024
26 #define GOTD_MAX_CONN_PER_UID	4
27 #define GOTD_FD_RESERVE		5
28 #define GOTD_FD_NEEDED		6
29 #define GOTD_FILENO_MSG_PIPE	3
30 
31 #define GOTD_DEFAULT_REQUEST_TIMEOUT	3600
32 
33 /* Client hash tables need some extra room. */
34 #define GOTD_CLIENT_TABLE_SIZE (GOTD_MAXCLIENTS * 4)
35 
36 enum gotd_procid {
37 	PROC_GOTD	= 0,
38 	PROC_LISTEN,
39 	PROC_AUTH,
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 unix_group_name[32];
123 	char user_name[32];
124 	struct gotd_repolist repos;
125 	int nrepos;
126 	struct gotd_child_proc listen_proc;
127 	struct timeval request_timeout;
128 	struct timeval auth_timeout;
129 	struct gotd_uid_connection_limit *connection_limits;
130 	size_t nconnection_limits;
131 
132 	char *argv0;
133 	const char *confpath;
134 	int daemonize;
135 	int verbosity;
136 };
137 
138 enum gotd_imsg_type {
139 	/* An error occured while processing a request. */
140 	GOTD_IMSG_ERROR,
141 
142 	/* Commands used by gotctl(8). */
143 	GOTD_IMSG_INFO,
144 	GOTD_IMSG_INFO_REPO,
145 	GOTD_IMSG_INFO_CLIENT,
146 	GOTD_IMSG_STOP,
147 
148 	/* Request a list of references. */
149 	GOTD_IMSG_LIST_REFS,
150 	GOTD_IMSG_LIST_REFS_INTERNAL,
151 
152 	/* References. */
153 	GOTD_IMSG_REFLIST,
154 	GOTD_IMSG_REF,
155 	GOTD_IMSG_SYMREF,
156 
157 	/* Git protocol capabilities. */
158 	GOTD_IMSG_CAPABILITIES,
159 	GOTD_IMSG_CAPABILITY,
160 
161 	/* Git protocol chatter. */
162 	GOTD_IMSG_WANT,		/* The client wants an object. */
163 	GOTD_IMSG_HAVE,		/* The client has an object. */
164 	GOTD_IMSG_ACK,		/* The server has an object or a reference. */
165 	GOTD_IMSG_NAK,		/* The server does not have an object/ref. */
166 	GOTD_IMSG_REF_UPDATE,	/* The client wants to update a reference. */
167 	GOTD_IMSG_REF_DELETE,	/* The client wants to delete a reference. */
168 	GOTD_IMSG_FLUSH,	/* The client sent a flush packet. */
169 	GOTD_IMSG_DONE,		/* The client is done chatting. */
170 
171 	/* Sending or receiving a pack file. */
172 	GOTD_IMSG_SEND_PACKFILE, /* The server is sending a pack file. */
173 	GOTD_IMSG_RECV_PACKFILE, /* The server is receiving a pack file. */
174 	GOTD_IMSG_PACKIDX_FILE,  /* Temporary file handle for new pack index. */
175 	GOTD_IMSG_PACKFILE_PIPE, /* Pipe to send/receive a pack file stream. */
176 	GOTD_IMSG_PACKFILE_PROGRESS, /* Progress reporting. */
177 	GOTD_IMSG_PACKFILE_READY, /* Pack file is ready to be sent. */
178 	GOTD_IMSG_PACKFILE_STATUS, /* Received pack success/failure status. */
179 	GOTD_IMSG_PACKFILE_INSTALL, /* Received pack file can be installed. */
180 	GOTD_IMSG_PACKFILE_DONE, /* Pack file has been sent/received. */
181 
182 	/* Reference updates. */
183 	GOTD_IMSG_REF_UPDATES_START, /* Ref updates starting. */
184 	GOTD_IMSG_REF_UPDATE_OK, /* Update went OK. */
185 	GOTD_IMSG_REF_UPDATE_NG, /* Update was not good. */
186 	GOTD_IMSG_REFS_UPDATED, /* The server proccessed all ref updates. */
187 
188 	/* Client connections. */
189 	GOTD_IMSG_DISCONNECT,
190 	GOTD_IMSG_CONNECT,
191 
192 	/* Child process management. */
193 	GOTD_IMSG_REPO_CHILD_READY,
194 
195 	/* Auth child process. */
196 	GOTD_IMSG_AUTHENTICATE,
197 	GOTD_IMSG_ACCESS_GRANTED,
198 };
199 
200 /* Structure for GOTD_IMSG_ERROR. */
201 struct gotd_imsg_error {
202 	int code; /* an error code from got_error.h */
203 	int errno_code; /* in case code equals GOT_ERR_ERRNO */
204 	uint32_t client_id;
205 	char msg[GOT_ERR_MAX_MSG_SIZE];
206 } __attribute__((__packed__));
207 
208 /* Structure for GOTD_IMSG_INFO. */
209 struct gotd_imsg_info {
210 	pid_t pid;
211 	int verbosity;
212 	int nrepos;
213 	int nclients;
214 
215 	/* Followed by nrepos GOTD_IMSG_INFO_REPO messages. */
216 	/* Followed by nclients GOTD_IMSG_INFO_CLIENT messages. */
217 };
218 
219 /* Structure for GOTD_IMSG_INFO_REPO. */
220 struct gotd_imsg_info_repo {
221 	char repo_name[NAME_MAX];
222 	char repo_path[PATH_MAX];
223 };
224 
225 /* Structure for GOTD_IMSG_INFO_CLIENT */
226 struct gotd_imsg_info_client {
227 	uid_t euid;
228 	gid_t egid;
229 	char repo_name[NAME_MAX];
230 	int is_writing;
231 	enum gotd_client_state state;
232 	size_t ncapabilities;
233 
234 	/* Followed by ncapabilities GOTD_IMSG_CAPABILITY. */
235 };
236 
237 /* Structure for GOTD_IMSG_LIST_REFS. */
238 struct gotd_imsg_list_refs {
239 	char repo_name[NAME_MAX];
240 	int client_is_reading; /* 1 if reading, 0 if writing */
241 };
242 
243 /* Structure for GOTD_IMSG_LIST_REFS_INTERNAL. */
244 struct gotd_imsg_list_refs_internal {
245 	uint32_t client_id;
246 };
247 
248 /* Structure for GOTD_IMSG_REFLIST. */
249 struct gotd_imsg_reflist {
250 	size_t nrefs;
251 
252 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
253 } __attribute__((__packed__));
254 
255 /* Structure for GOTD_IMSG_REF data. */
256 struct gotd_imsg_ref {
257 	uint8_t id[SHA1_DIGEST_LENGTH];
258 	size_t name_len;
259 	/* Followed by name_len data bytes. */
260 } __attribute__((__packed__));
261 
262 /* Structure for GOTD_IMSG_SYMREF data. */
263 struct gotd_imsg_symref {
264 	size_t name_len;
265 	size_t target_len;
266 	uint8_t target_id[SHA1_DIGEST_LENGTH];
267 
268 	/*
269 	 * Followed by name_len + target_len data bytes.
270 	 */
271 } __attribute__((__packed__));
272 
273 /* Structure for GOTD_IMSG_CAPABILITIES data. */
274 struct gotd_imsg_capabilities {
275 	size_t ncapabilities;
276 
277 	/*
278 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
279 	 */
280 } __attribute__((__packed__));
281 
282 /* Structure for GOTD_IMSG_CAPABILITY data. */
283 struct gotd_imsg_capability {
284 	size_t key_len;
285 	size_t value_len;
286 
287 	/*
288 	 * Followed by key_len + value_len data bytes.
289 	 */
290 } __attribute__((__packed__));
291 
292 /* Structure for GOTD_IMSG_WANT data. */
293 struct gotd_imsg_want {
294 	uint8_t object_id[SHA1_DIGEST_LENGTH];
295 	uint32_t client_id;
296 } __attribute__((__packed__));
297 
298 /* Structure for GOTD_IMSG_HAVE data. */
299 struct gotd_imsg_have {
300 	uint8_t object_id[SHA1_DIGEST_LENGTH];
301 	uint32_t client_id;
302 } __attribute__((__packed__));
303 
304 /* Structure for GOTD_IMSG_ACK data. */
305 struct gotd_imsg_ack {
306 	uint8_t object_id[SHA1_DIGEST_LENGTH];
307 	uint32_t client_id;
308 } __attribute__((__packed__));
309 
310 /* Structure for GOTD_IMSG_NAK data. */
311 struct gotd_imsg_nak {
312 	uint8_t object_id[SHA1_DIGEST_LENGTH];
313 	uint32_t client_id;
314 } __attribute__((__packed__));
315 
316 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
317 struct gotd_imsg_packfile_status {
318 	size_t reason_len;
319 
320 	/* Followed by reason_len data bytes. */
321 } __attribute__((__packed__));
322 
323 
324 /* Structure for GOTD_IMSG_REF_UPDATE data. */
325 struct gotd_imsg_ref_update {
326 	uint8_t old_id[SHA1_DIGEST_LENGTH];
327 	uint8_t new_id[SHA1_DIGEST_LENGTH];
328 	int ref_is_new;
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_sha1[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_AUTHENTICATE. */
434 struct gotd_imsg_auth {
435 	uid_t euid;
436 	gid_t egid;
437 	int required_auth;
438 	uint32_t client_id;
439 };
440 
441 int parse_config(const char *, enum gotd_procid, struct gotd *);
442 
443 /* imsg.c */
444 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
445 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
446 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
447     size_t);
448 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
449     struct imsg *imsg);
450 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
451     const struct got_error *);
452 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
453     const struct got_error *);
454 void gotd_imsg_event_add(struct gotd_imsgev *);
455 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
456     void *, uint16_t);
457 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
458 
459 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
460     uint32_t, pid_t);
461 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
462     uint32_t, pid_t);