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