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_FD_RESERVE		5
27 #define GOTD_FD_NEEDED		6
28 #define GOTD_FILENO_MSG_PIPE	3
29 
30 /* Client hash tables need some extra room. */
31 #define GOTD_CLIENT_TABLE_SIZE (GOTD_MAXCLIENTS * 4)
32 
33 enum gotd_procid {
34 	PROC_GOTD	= 0,
35 	PROC_LISTEN,
36 	PROC_REPO_READ,
37 	PROC_REPO_WRITE,
38 	PROC_MAX,
39 };
40 
41 struct gotd_imsgev {
42 	struct imsgbuf	 ibuf;
43 	void		(*handler)(int, short, void *);
44 	void		*handler_arg;
45 	struct event	 ev;
46 	short		 events;
47 };
48 
49 struct gotd_child_proc {
50 	pid_t pid;
51 	enum gotd_procid type;
52 	char repo_name[NAME_MAX];
53 	char repo_path[PATH_MAX];
54 	int pipe[2];
55 	struct gotd_imsgev iev;
56 	size_t nhelpers;
57 };
58 
59 enum gotd_access {
60 	GOTD_ACCESS_PERMITTED = 1,
61 	GOTD_ACCESS_DENIED
62 };
63 
64 struct gotd_access_rule {
65 	STAILQ_ENTRY(gotd_access_rule) entry;
66 
67 	enum gotd_access access;
68 
69 	int authorization;
70 #define GOTD_AUTH_READ		0x1
71 #define GOTD_AUTH_WRITE		0x2
72 
73 	char *identifier;
74 };
75 STAILQ_HEAD(gotd_access_rule_list, gotd_access_rule);
76 
77 struct gotd_repo {
78 	TAILQ_ENTRY(gotd_repo)	 entry;
79 
80 	char name[NAME_MAX];
81 	char path[PATH_MAX];
82 
83 	struct gotd_access_rule_list rules;
84 };
85 TAILQ_HEAD(gotd_repolist, gotd_repo);
86 
87 enum gotd_client_state {
88 	GOTD_STATE_EXPECT_LIST_REFS,
89 	GOTD_STATE_EXPECT_CAPABILITIES,
90 	GOTD_STATE_EXPECT_WANT,
91 	GOTD_STATE_EXPECT_REF_UPDATE,
92 	GOTD_STATE_EXPECT_MORE_REF_UPDATES,
93 	GOTD_STATE_EXPECT_HAVE,
94 	GOTD_STATE_EXPECT_PACKFILE,
95 	GOTD_STATE_EXPECT_DONE,
96 	GOTD_STATE_DONE,
97 };
98 
99 struct gotd_client_capability {
100 	char *key;
101 	char *value;
102 };
103 
104 struct gotd_object_id_array {
105 	struct got_object_id		**ids;
106 	size_t				 nalloc;
107 	size_t				 nids;
108 };
109 
110 struct gotd {
111 	pid_t pid;
112 	char unix_socket_path[PATH_MAX];
113 	char unix_group_name[32];
114 	char user_name[32];
115 	struct gotd_repolist repos;
116 	int nrepos;
117 	struct gotd_child_proc listen_proc;
118 
119 	char *argv0;
120 	const char *confpath;
121 	int daemonize;
122 	int verbosity;
123 };
124 
125 enum gotd_imsg_type {
126 	/* An error occured while processing a request. */
127 	GOTD_IMSG_ERROR,
128 
129 	/* Commands used by gotctl(8). */
130 	GOTD_IMSG_INFO,
131 	GOTD_IMSG_INFO_REPO,
132 	GOTD_IMSG_INFO_CLIENT,
133 	GOTD_IMSG_STOP,
134 
135 	/* Request a list of references. */
136 	GOTD_IMSG_LIST_REFS,
137 	GOTD_IMSG_LIST_REFS_INTERNAL,
138 
139 	/* References. */
140 	GOTD_IMSG_REFLIST,
141 	GOTD_IMSG_REF,
142 	GOTD_IMSG_SYMREF,
143 
144 	/* Git protocol capabilities. */
145 	GOTD_IMSG_CAPABILITIES,
146 	GOTD_IMSG_CAPABILITY,
147 
148 	/* Git protocol chatter. */
149 	GOTD_IMSG_WANT,		/* The client wants an object. */
150 	GOTD_IMSG_HAVE,		/* The client has an object. */
151 	GOTD_IMSG_ACK,		/* The server has an object or a reference. */
152 	GOTD_IMSG_NAK,		/* The server does not have an object/ref. */
153 	GOTD_IMSG_REF_UPDATE,	/* The client wants to update a reference. */
154 	GOTD_IMSG_REF_DELETE,	/* The client wants to delete a reference. */
155 	GOTD_IMSG_FLUSH,	/* The client sent a flush packet. */
156 	GOTD_IMSG_DONE,		/* The client is done chatting. */
157 
158 	/* Sending or receiving a pack file. */
159 	GOTD_IMSG_SEND_PACKFILE, /* The server is sending a pack file. */
160 	GOTD_IMSG_RECV_PACKFILE, /* The server is receiving a pack file. */
161 	GOTD_IMSG_PACKIDX_FILE,  /* Temporary file handle for new pack index. */
162 	GOTD_IMSG_PACKFILE_PIPE, /* Pipe to send/receive a pack file stream. */
163 	GOTD_IMSG_PACKFILE_PROGRESS, /* Progress reporting. */
164 	GOTD_IMSG_PACKFILE_READY, /* Pack file is ready to be sent. */
165 	GOTD_IMSG_PACKFILE_STATUS, /* Received pack success/failure status. */
166 	GOTD_IMSG_PACKFILE_INSTALL, /* Received pack file can be installed. */
167 	GOTD_IMSG_PACKFILE_DONE, /* Pack file has been sent/received. */
168 
169 	/* Reference updates. */
170 	GOTD_IMSG_REF_UPDATES_START, /* Ref updates starting. */
171 	GOTD_IMSG_REF_UPDATE_OK, /* Update went OK. */
172 	GOTD_IMSG_REF_UPDATE_NG, /* Update was not good. */
173 	GOTD_IMSG_REFS_UPDATED, /* The server proccessed all ref updates. */
174 
175 	/* Client connections. */
176 	GOTD_IMSG_DISCONNECT,
177 	GOTD_IMSG_CONNECT,
178 
179 	/* Child process management. */
180 	GOTD_IMSG_REPO_CHILD_READY,
181 };
182 
183 /* Structure for GOTD_IMSG_ERROR. */
184 struct gotd_imsg_error {
185 	int code; /* an error code from got_error.h */
186 	int errno_code; /* in case code equals GOT_ERR_ERRNO */
187 	uint32_t client_id;
188 	char msg[GOT_ERR_MAX_MSG_SIZE];
189 } __attribute__((__packed__));
190 
191 /* Structure for GOTD_IMSG_INFO. */
192 struct gotd_imsg_info {
193 	pid_t pid;
194 	int verbosity;
195 	int nrepos;
196 	int nclients;
197 
198 	/* Followed by nrepos GOTD_IMSG_INFO_REPO messages. */
199 	/* Followed by nclients GOTD_IMSG_INFO_CLIENT messages. */
200 };
201 
202 /* Structure for GOTD_IMSG_INFO_REPO. */
203 struct gotd_imsg_info_repo {
204 	char repo_name[NAME_MAX];
205 	char repo_path[PATH_MAX];
206 };
207 
208 /* Structure for GOTD_IMSG_INFO_CLIENT */
209 struct gotd_imsg_info_client {
210 	uid_t euid;
211 	gid_t egid;
212 	char repo_name[NAME_MAX];
213 	int is_writing;
214 	enum gotd_client_state state;
215 	size_t ncapabilities;
216 
217 	/* Followed by ncapabilities GOTD_IMSG_CAPABILITY. */
218 };
219 
220 /* Structure for GOTD_IMSG_LIST_REFS. */
221 struct gotd_imsg_list_refs {
222 	char repo_name[NAME_MAX];
223 	int client_is_reading; /* 1 if reading, 0 if writing */
224 };
225 
226 /* Structure for GOTD_IMSG_LIST_REFS_INTERNAL. */
227 struct gotd_imsg_list_refs_internal {
228 	uint32_t client_id;
229 };
230 
231 /* Structure for GOTD_IMSG_REFLIST. */
232 struct gotd_imsg_reflist {
233 	size_t nrefs;
234 
235 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
236 } __attribute__((__packed__));
237 
238 /* Structure for GOTD_IMSG_REF data. */
239 struct gotd_imsg_ref {
240 	uint8_t id[SHA1_DIGEST_LENGTH];
241 	size_t name_len;
242 	/* Followed by name_len data bytes. */
243 } __attribute__((__packed__));
244 
245 /* Structure for GOTD_IMSG_SYMREF data. */
246 struct gotd_imsg_symref {
247 	size_t name_len;
248 	size_t target_len;
249 	uint8_t target_id[SHA1_DIGEST_LENGTH];
250 
251 	/*
252 	 * Followed by name_len + target_len data bytes.
253 	 */
254 } __attribute__((__packed__));
255 
256 /* Structure for GOTD_IMSG_CAPABILITIES data. */
257 struct gotd_imsg_capabilities {
258 	size_t ncapabilities;
259 
260 	/*
261 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
262 	 */
263 } __attribute__((__packed__));
264 
265 /* Structure for GOTD_IMSG_CAPABILITY data. */
266 struct gotd_imsg_capability {
267 	size_t key_len;
268 	size_t value_len;
269 
270 	/*
271 	 * Followed by key_len + value_len data bytes.
272 	 */
273 } __attribute__((__packed__));
274 
275 /* Structure for GOTD_IMSG_WANT data. */
276 struct gotd_imsg_want {
277 	uint8_t object_id[SHA1_DIGEST_LENGTH];
278 	uint32_t client_id;
279 } __attribute__((__packed__));
280 
281 /* Structure for GOTD_IMSG_HAVE data. */
282 struct gotd_imsg_have {
283 	uint8_t object_id[SHA1_DIGEST_LENGTH];
284 	uint32_t client_id;
285 } __attribute__((__packed__));
286 
287 /* Structure for GOTD_IMSG_ACK data. */
288 struct gotd_imsg_ack {
289 	uint8_t object_id[SHA1_DIGEST_LENGTH];
290 	uint32_t client_id;
291 } __attribute__((__packed__));
292 
293 /* Structure for GOTD_IMSG_NAK data. */
294 struct gotd_imsg_nak {
295 	uint8_t object_id[SHA1_DIGEST_LENGTH];
296 	uint32_t client_id;
297 } __attribute__((__packed__));
298 
299 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
300 struct gotd_imsg_packfile_status {
301 	size_t reason_len;
302 
303 	/* Followed by reason_len data bytes. */
304 } __attribute__((__packed__));
305 
306 
307 /* Structure for GOTD_IMSG_REF_UPDATE data. */
308 struct gotd_imsg_ref_update {
309 	uint8_t old_id[SHA1_DIGEST_LENGTH];
310 	uint8_t new_id[SHA1_DIGEST_LENGTH];
311 	int ref_is_new;
312 	uint32_t client_id;
313 	size_t name_len;
314 
315 	/* Followed by name_len data bytes. */
316 } __attribute__((__packed__));
317 
318 /* Structure for GOTD_IMSG_REF_UPDATES_START data. */
319 struct gotd_imsg_ref_updates_start {
320 	int nref_updates;
321 	uint32_t client_id;
322 
323 	/* Followed by nref_updates GOT_IMSG_REF_UPDATE_OK/NG messages. */
324 };
325 
326 /* Structure for GOTD_IMSG_REF_UPDATE_OK data. */
327 struct gotd_imsg_ref_update_ok {
328 	uint8_t old_id[SHA1_DIGEST_LENGTH];
329 	uint8_t new_id[SHA1_DIGEST_LENGTH];
330 	int ref_is_new;
331 	uint32_t client_id;
332 	size_t name_len;
333 
334 	/* Followed by name_len data bytes. */
335 } __attribute__((__packed__));
336 
337 /* Structure for GOTD_IMSG_REF_UPDATE_NG data. */
338 struct gotd_imsg_ref_update_ng {
339 	uint8_t old_id[SHA1_DIGEST_LENGTH];
340 	uint8_t new_id[SHA1_DIGEST_LENGTH];
341 	uint32_t client_id;
342 	size_t name_len;
343 	size_t reason_len;
344 
345 	/* Followed by name_len + reason_len data bytes. */
346 } __attribute__((__packed__));
347 
348 /* Structure for GOTD_IMSG_SEND_PACKFILE data. */
349 struct gotd_imsg_send_packfile {
350 	uint32_t client_id;
351 	int report_progress;
352 
353 	/* delta cache file is sent as a file descriptor */
354 
355 	/* followed by two GOTD_IMSG_PACKFILE_PIPE messages */
356 };
357 
358 /* Structure for GOTD_IMSG_RECV_PACKFILE data. */
359 struct gotd_imsg_recv_packfile {
360 	uint32_t client_id;
361 	int report_status;
362 
363 	/* pack destination temp file is sent as a file descriptor */
364 };
365 
366 /* Structure for GOTD_IMSG_PACKFILE_PIPE data. */
367 struct gotd_imsg_packfile_pipe {
368 	uint32_t client_id;
369 };
370 
371 /* Structure for GOTD_IMSG_PACKIDX_FILE data. */
372 struct gotd_imsg_packidx_file {
373 	uint32_t client_id;
374 };
375 
376 
377 /*
378  * Structure for GOTD_IMSG_PACKFILE_PROGRESS and
379  * GOTD_IMSG_PACKFILE_READY data.
380  */
381 struct gotd_imsg_packfile_progress {
382 	uint32_t client_id;
383 	int ncolored;
384 	int nfound;
385 	int ntrees;
386 	off_t packfile_size;
387 	int ncommits;
388 	int nobj_total;
389 	int nobj_deltify;
390 	int nobj_written;
391 };
392 
393 /* Structure for GOTD_IMSG_PACKFILE_INSTALL. */
394 struct gotd_imsg_packfile_install {
395 	uint32_t client_id;
396 	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
397 };
398 
399 /* Structure for GOTD_IMSG_PACKFILE_DONE data. */
400 struct gotd_imsg_packfile_done {
401 	uint32_t client_id;
402 };
403 
404 /* Structure for GOTD_IMSG_DISCONNECT data. */
405 struct gotd_imsg_disconnect {
406 	uint32_t client_id;
407 };
408 
409 /* Structure for GOTD_IMSG_CONNECT. */
410 struct gotd_imsg_connect {
411 	uint32_t client_id;
412 };
413 
414 int parse_config(const char *, enum gotd_procid, struct gotd *);
415 
416 /* imsg.c */
417 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
418 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
419 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
420     size_t);
421 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
422     struct imsg *imsg);
423 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
424     const struct got_error *);
425 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
426     const struct got_error *);
427 void gotd_imsg_event_add(struct gotd_imsgev *);
428 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
429     void *, uint16_t);
430 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
431 
432 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
433     uint32_t, pid_t);
434 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
435     uint32_t, pid_t);