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 
24 #define GOTD_MAXCLIENTS		1024
25 #define GOTD_FD_RESERVE		5
26 #define GOTD_FD_NEEDED		6
27 #define GOTD_SOCK_FILENO	3
28 
29 /* Client hash tables need some extra room. */
30 #define GOTD_CLIENT_TABLE_SIZE (GOTD_MAXCLIENTS * 4)
31 
32 enum gotd_procid {
33 	PROC_GOTD	= 0,
34 	PROC_REPO_READ,
35 	PROC_REPO_WRITE,
36 	PROC_MAX,
37 };
38 
39 struct gotd_imsgev {
40 	struct imsgbuf	 ibuf;
41 	void		(*handler)(int, short, void *);
42 	void		*handler_arg;
43 	struct event	 ev;
44 	short		 events;
45 };
46 
47 struct gotd_child_proc {
48 	pid_t pid;
49 	enum gotd_procid type;
50 	char repo_name[NAME_MAX];
51 	char chroot_path[PATH_MAX];
52 	int pipe[2];
53 	struct gotd_imsgev iev;
54 	size_t nhelpers;
55 };
56 
57 enum gotd_access {
58 	GOTD_ACCESS_PERMITTED = 1,
59 	GOTD_ACCESS_DENIED
60 };
61 
62 struct gotd_access_rule {
63 	STAILQ_ENTRY(gotd_access_rule) entry;
64 
65 	enum gotd_access access;
66 
67 	int authorization;
68 #define GOTD_AUTH_READ		0x1
69 #define GOTD_AUTH_WRITE		0x2
70 
71 	char *identifier;
72 };
73 STAILQ_HEAD(gotd_access_rule_list, gotd_access_rule);
74 
75 struct gotd_repo {
76 	TAILQ_ENTRY(gotd_repo)	 entry;
77 
78 	char name[NAME_MAX];
79 	char path[PATH_MAX];
80 
81 	struct gotd_access_rule_list rules;
82 };
83 TAILQ_HEAD(gotd_repolist, gotd_repo);
84 
85 enum gotd_client_state {
86 	GOTD_STATE_EXPECT_LIST_REFS,
87 	GOTD_STATE_EXPECT_CAPABILITIES,
88 	GOTD_STATE_EXPECT_WANT,
89 	GOTD_STATE_EXPECT_REF_UPDATE,
90 	GOTD_STATE_EXPECT_MORE_REF_UPDATES,
91 	GOTD_STATE_EXPECT_HAVE,
92 	GOTD_STATE_EXPECT_PACKFILE,
93 	GOTD_STATE_EXPECT_DONE,
94 	GOTD_STATE_DONE,
95 };
96 
97 struct gotd_client_capability {
98 	char *key;
99 	char *value;
100 };
101 
102 struct gotd_object_id_array {
103 	struct got_object_id		**ids;
104 	size_t				 nalloc;
105 	size_t				 nids;
106 };
107 
108 struct gotd {
109 	pid_t pid;
110 	char unix_socket_path[PATH_MAX];
111 	char unix_group_name[32];
112 	char user_name[32];
113 	struct gotd_repolist repos;
114 	int nrepos;
115 	int verbosity;
116 	struct event ev;
117 	struct event pause;
118 	struct gotd_child_proc *procs;
119 	int nprocs;
120 };
121 
122 enum gotd_imsg_type {
123 	/* An error occured while processing a request. */
124 	GOTD_IMSG_ERROR,
125 
126 	/* Commands used by gotctl(8). */
127 	GOTD_IMSG_INFO,
128 	GOTD_IMSG_INFO_REPO,
129 	GOTD_IMSG_INFO_CLIENT,
130 	GOTD_IMSG_STOP,
131 
132 	/* Request a list of references. */
133 	GOTD_IMSG_LIST_REFS,
134 	GOTD_IMSG_LIST_REFS_INTERNAL,
135 
136 	/* References. */
137 	GOTD_IMSG_REFLIST,
138 	GOTD_IMSG_REF,
139 	GOTD_IMSG_SYMREF,
140 
141 	/* Git protocol capabilities. */
142 	GOTD_IMSG_CAPABILITIES,
143 	GOTD_IMSG_CAPABILITY,
144 
145 	/* Git protocol chatter. */
146 	GOTD_IMSG_WANT,		/* The client wants an object. */
147 	GOTD_IMSG_HAVE,		/* The client has an object. */
148 	GOTD_IMSG_ACK,		/* The server has an object or a reference. */
149 	GOTD_IMSG_NAK,		/* The server does not have an object/ref. */
150 	GOTD_IMSG_REF_UPDATE,	/* The client wants to update a reference. */
151 	GOTD_IMSG_REF_DELETE,	/* The client wants to delete a reference. */
152 	GOTD_IMSG_FLUSH,	/* The client sent a flush packet. */
153 	GOTD_IMSG_DONE,		/* The client is done chatting. */
154 
155 	/* Sending or receiving a pack file. */
156 	GOTD_IMSG_SEND_PACKFILE, /* The server is sending a pack file. */
157 	GOTD_IMSG_RECV_PACKFILE, /* The server is receiving a pack file. */
158 	GOTD_IMSG_PACKIDX_FILE,  /* Temporary file handle for new pack index. */
159 	GOTD_IMSG_PACKFILE_PIPE, /* Pipe to send/receive a pack file stream. */
160 	GOTD_IMSG_PACKFILE_PROGRESS, /* Progress reporting. */
161 	GOTD_IMSG_PACKFILE_READY, /* Pack file is ready to be sent. */
162 	GOTD_IMSG_PACKFILE_STATUS, /* Received pack success/failure status. */
163 	GOTD_IMSG_PACKFILE_INSTALL, /* Received pack file can be installed. */
164 	GOTD_IMSG_PACKFILE_DONE, /* Pack file has been sent/received. */
165 
166 	/* Reference updates. */
167 	GOTD_IMSG_REF_UPDATES_START, /* Ref updates starting. */
168 	GOTD_IMSG_REF_UPDATE_OK, /* Update went OK. */
169 	GOTD_IMSG_REF_UPDATE_NG, /* Update was not good. */
170 	GOTD_IMSG_REFS_UPDATED, /* The server proccessed all ref updates. */
171 
172 	/* Client is disconnecting. */
173 	GOTD_IMSG_DISCONNECT,
174 };
175 
176 /* Structure for GOTD_IMSG_ERROR. */
177 struct gotd_imsg_error {
178 	int code; /* an error code from got_error.h */
179 	int errno_code; /* in case code equals GOT_ERR_ERRNO */
180 	uint32_t client_id;
181 	char msg[GOT_ERR_MAX_MSG_SIZE];
182 } __attribute__((__packed__));
183 
184 /* Structure for GOTD_IMSG_INFO. */
185 struct gotd_imsg_info {
186 	pid_t pid;
187 	int verbosity;
188 	int nrepos;
189 	int nclients;
190 
191 	/* Followed by nrepos GOTD_IMSG_INFO_REPO messages. */
192 	/* Followed by nclients GOTD_IMSG_INFO_CLIENT messages. */
193 };
194 
195 /* Structure for GOTD_IMSG_INFO_REPO. */
196 struct gotd_imsg_info_repo {
197 	char repo_name[NAME_MAX];
198 	char repo_path[PATH_MAX];
199 };
200 
201 /* Structure for GOTD_IMSG_INFO_CLIENT */
202 struct gotd_imsg_info_client {
203 	uid_t euid;
204 	gid_t egid;
205 	char repo_name[NAME_MAX];
206 	int is_writing;
207 	enum gotd_client_state state;
208 	size_t ncapabilities;
209 
210 	/* Followed by ncapabilities GOTD_IMSG_CAPABILITY. */
211 };
212 
213 /* Structure for GOTD_IMSG_LIST_REFS. */
214 struct gotd_imsg_list_refs {
215 	char repo_name[NAME_MAX];
216 	int client_is_reading; /* 1 if reading, 0 if writing */
217 };
218 
219 /* Structure for GOTD_IMSG_LIST_REFS_INTERNAL. */
220 struct gotd_imsg_list_refs_internal {
221 	uint32_t client_id;
222 };
223 
224 /* Structure for GOTD_IMSG_REFLIST. */
225 struct gotd_imsg_reflist {
226 	size_t nrefs;
227 
228 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
229 } __attribute__((__packed__));
230 
231 /* Structure for GOTD_IMSG_REF data. */
232 struct gotd_imsg_ref {
233 	uint8_t id[SHA1_DIGEST_LENGTH];
234 	size_t name_len;
235 	/* Followed by name_len data bytes. */
236 } __attribute__((__packed__));
237 
238 /* Structure for GOTD_IMSG_SYMREF data. */
239 struct gotd_imsg_symref {
240 	size_t name_len;
241 	size_t target_len;
242 	uint8_t target_id[SHA1_DIGEST_LENGTH];
243 
244 	/*
245 	 * Followed by name_len + target_len data bytes.
246 	 */
247 } __attribute__((__packed__));
248 
249 /* Structure for GOTD_IMSG_CAPABILITIES data. */
250 struct gotd_imsg_capabilities {
251 	size_t ncapabilities;
252 
253 	/*
254 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
255 	 */
256 } __attribute__((__packed__));
257 
258 /* Structure for GOTD_IMSG_CAPABILITY data. */
259 struct gotd_imsg_capability {
260 	size_t key_len;
261 	size_t value_len;
262 
263 	/*
264 	 * Followed by key_len + value_len data bytes.
265 	 */
266 } __attribute__((__packed__));
267 
268 /* Structure for GOTD_IMSG_WANT data. */
269 struct gotd_imsg_want {
270 	uint8_t object_id[SHA1_DIGEST_LENGTH];
271 	uint32_t client_id;
272 } __attribute__((__packed__));
273 
274 /* Structure for GOTD_IMSG_HAVE data. */
275 struct gotd_imsg_have {
276 	uint8_t object_id[SHA1_DIGEST_LENGTH];
277 	uint32_t client_id;
278 } __attribute__((__packed__));
279 
280 /* Structure for GOTD_IMSG_ACK data. */
281 struct gotd_imsg_ack {
282 	uint8_t object_id[SHA1_DIGEST_LENGTH];
283 	uint32_t client_id;
284 } __attribute__((__packed__));
285 
286 /* Structure for GOTD_IMSG_NAK data. */
287 struct gotd_imsg_nak {
288 	uint8_t object_id[SHA1_DIGEST_LENGTH];
289 	uint32_t client_id;
290 } __attribute__((__packed__));
291 
292 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
293 struct gotd_imsg_packfile_status {
294 	size_t reason_len;
295 
296 	/* Followed by reason_len data bytes. */
297 } __attribute__((__packed__));
298 
299 
300 /* Structure for GOTD_IMSG_REF_UPDATE data. */
301 struct gotd_imsg_ref_update {
302 	uint8_t old_id[SHA1_DIGEST_LENGTH];
303 	uint8_t new_id[SHA1_DIGEST_LENGTH];
304 	int ref_is_new;
305 	uint32_t client_id;
306 	size_t name_len;
307 
308 	/* Followed by name_len data bytes. */
309 } __attribute__((__packed__));
310 
311 /* Structure for GOTD_IMSG_REF_UPDATES_START data. */
312 struct gotd_imsg_ref_updates_start {
313 	int nref_updates;
314 	uint32_t client_id;
315 
316 	/* Followed by nref_updates GOT_IMSG_REF_UPDATE_OK/NG messages. */
317 };
318 
319 /* Structure for GOTD_IMSG_REF_UPDATE_OK data. */
320 struct gotd_imsg_ref_update_ok {
321 	uint8_t old_id[SHA1_DIGEST_LENGTH];
322 	uint8_t new_id[SHA1_DIGEST_LENGTH];
323 	int ref_is_new;
324 	uint32_t client_id;
325 	size_t name_len;
326 
327 	/* Followed by name_len data bytes. */
328 } __attribute__((__packed__));
329 
330 /* Structure for GOTD_IMSG_REF_UPDATE_NG data. */
331 struct gotd_imsg_ref_update_ng {
332 	uint8_t old_id[SHA1_DIGEST_LENGTH];
333 	uint8_t new_id[SHA1_DIGEST_LENGTH];
334 	uint32_t client_id;
335 	size_t name_len;
336 	size_t reason_len;
337 
338 	/* Followed by name_len + reason_len data bytes. */
339 } __attribute__((__packed__));
340 
341 /* Structure for GOTD_IMSG_SEND_PACKFILE data. */
342 struct gotd_imsg_send_packfile {
343 	uint32_t client_id;
344 	int report_progress;
345 
346 	/* delta cache file is sent as a file descriptor */
347 
348 	/* followed by two GOTD_IMSG_PACKFILE_PIPE messages */
349 };
350 
351 /* Structure for GOTD_IMSG_RECV_PACKFILE data. */
352 struct gotd_imsg_recv_packfile {
353 	uint32_t client_id;
354 	int report_status;
355 
356 	/* pack destination temp file is sent as a file descriptor */
357 };
358 
359 /* Structure for GOTD_IMSG_PACKFILE_PIPE data. */
360 struct gotd_imsg_packfile_pipe {
361 	uint32_t client_id;
362 };
363 
364 /* Structure for GOTD_IMSG_PACKIDX_FILE data. */
365 struct gotd_imsg_packidx_file {
366 	uint32_t client_id;
367 };
368 
369 
370 /*
371  * Structure for GOTD_IMSG_PACKFILE_PROGRESS and
372  * GOTD_IMSG_PACKFILE_READY data.
373  */
374 struct gotd_imsg_packfile_progress {
375 	uint32_t client_id;
376 	int ncolored;
377 	int nfound;
378 	int ntrees;
379 	off_t packfile_size;
380 	int ncommits;
381 	int nobj_total;
382 	int nobj_deltify;
383 	int nobj_written;
384 };
385 
386 /* Structure for GOTD_IMSG_PACKFILE_INSTALL. */
387 struct gotd_imsg_packfile_install {
388 	uint32_t client_id;
389 	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
390 };
391 
392 /* Structure for GOTD_IMSG_PACKFILE_DONE data. */
393 struct gotd_imsg_packfile_done {
394 	uint32_t client_id;
395 };
396 
397 /* Structure for GOTD_IMSG_DISCONNECT data. */
398 struct gotd_imsg_disconnect {
399 	uint32_t client_id;
400 };
401 
402 int parse_config(const char *, enum gotd_procid, struct gotd *);
403 
404 /* imsg.c */
405 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
406 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
407 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
408     size_t);
409 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
410     struct imsg *imsg);
411 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
412     const struct got_error *);
413 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
414     const struct got_error *);
415 void gotd_imsg_event_add(struct gotd_imsgev *);
416 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
417     void *, uint16_t);
418 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
419 
420 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
421     uint32_t, pid_t);
422 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
423     uint32_t, pid_t);