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