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 	/* Request a list of references. */
107 	GOTD_IMSG_LIST_REFS,
108 	GOTD_IMSG_LIST_REFS_INTERNAL,
109 
110 	/* References. */
111 	GOTD_IMSG_REFLIST,
112 	GOTD_IMSG_REF,
113 	GOTD_IMSG_SYMREF,
114 
115 	/* Git protocol capabilities. */
116 	GOTD_IMSG_CAPABILITIES,
117 	GOTD_IMSG_CAPABILITY,
118 
119 	/* Git protocol chatter. */
120 	GOTD_IMSG_WANT,		/* The client wants an object. */
121 	GOTD_IMSG_HAVE,		/* The client has an object. */
122 	GOTD_IMSG_ACK,		/* The server has an object or a reference. */
123 	GOTD_IMSG_NAK,		/* The server does not have an object/ref. */
124 	GOTD_IMSG_REF_UPDATE,	/* The client wants to update a reference. */
125 	GOTD_IMSG_REF_DELETE,	/* The client wants to delete a reference. */
126 	GOTD_IMSG_FLUSH,	/* The client sent a flush packet. */
127 	GOTD_IMSG_DONE,		/* The client is done chatting. */
128 
129 	/* Sending or receiving a pack file. */
130 	GOTD_IMSG_SEND_PACKFILE, /* The server is sending a pack file. */
131 	GOTD_IMSG_RECV_PACKFILE, /* The server is receiving a pack file. */
132 	GOTD_IMSG_PACKIDX_FILE,  /* Temporary file handle for new pack index. */
133 	GOTD_IMSG_PACKFILE_PIPE, /* Pipe to send/receive a pack file stream. */
134 	GOTD_IMSG_PACKFILE_PROGRESS, /* Progress reporting. */
135 	GOTD_IMSG_PACKFILE_READY, /* Pack file is ready to be sent. */
136 	GOTD_IMSG_PACKFILE_STATUS, /* Received pack success/failure status. */
137 	GOTD_IMSG_PACKFILE_INSTALL, /* Received pack file can be installed. */
138 	GOTD_IMSG_PACKFILE_DONE, /* Pack file has been sent/received. */
139 
140 	/* Reference updates. */
141 	GOTD_IMSG_REF_UPDATES_START, /* Ref updates starting. */
142 	GOTD_IMSG_REF_UPDATE_OK, /* Update went OK. */
143 	GOTD_IMSG_REF_UPDATE_NG, /* Update was not good. */
144 	GOTD_IMSG_REFS_UPDATED, /* The server proccessed all ref updates. */
145 
146 	/* Client is disconnecting. */
147 	GOTD_IMSG_DISCONNECT,
148 };
149 
150 /* Structure for GOTD_IMSG_ERROR. */
151 struct gotd_imsg_error {
152 	int code; /* an error code from got_error.h */
153 	int errno_code; /* in case code equals GOT_ERR_ERRNO */
154 	uint32_t client_id;
155 	char msg[GOT_ERR_MAX_MSG_SIZE];
156 } __attribute__((__packed__));
157 
158 /* Structure for GOTD_IMSG_LIST_REFS. */
159 struct gotd_imsg_list_refs {
160 	char repo_name[NAME_MAX];
161 	int client_is_reading; /* 1 if reading, 0 if writing */
162 };
163 
164 /* Structure for GOTD_IMSG_LIST_REFS_INTERNAL. */
165 struct gotd_imsg_list_refs_internal {
166 	uint32_t client_id;
167 };
168 
169 /* Structure for GOTD_IMSG_REFLIST. */
170 struct gotd_imsg_reflist {
171 	size_t nrefs;
172 
173 	/* Followed by nrefs times of gotd_imsg_ref/gotd_imsg_symref data. */
174 } __attribute__((__packed__));
175 
176 /* Structure for GOTD_IMSG_REF data. */
177 struct gotd_imsg_ref {
178 	uint8_t id[SHA1_DIGEST_LENGTH];
179 	size_t name_len;
180 	/* Followed by name_len data bytes. */
181 } __attribute__((__packed__));
182 
183 /* Structure for GOTD_IMSG_SYMREF data. */
184 struct gotd_imsg_symref {
185 	size_t name_len;
186 	size_t target_len;
187 	uint8_t target_id[SHA1_DIGEST_LENGTH];
188 
189 	/*
190 	 * Followed by name_len + target_len data bytes.
191 	 */
192 } __attribute__((__packed__));
193 
194 /* Structure for GOTD_IMSG_CAPABILITIES data. */
195 struct gotd_imsg_capabilities {
196 	size_t ncapabilities;
197 
198 	/*
199 	 * Followed by ncapabilities * GOTD_IMSG_CAPABILITY.
200 	 */
201 } __attribute__((__packed__));
202 
203 /* Structure for GOTD_IMSG_CAPABILITY data. */
204 struct gotd_imsg_capability {
205 	size_t key_len;
206 	size_t value_len;
207 
208 	/*
209 	 * Followed by key_len + value_len data bytes.
210 	 */
211 } __attribute__((__packed__));
212 
213 /* Structure for GOTD_IMSG_WANT data. */
214 struct gotd_imsg_want {
215 	uint8_t object_id[SHA1_DIGEST_LENGTH];
216 	uint32_t client_id;
217 } __attribute__((__packed__));
218 
219 /* Structure for GOTD_IMSG_HAVE data. */
220 struct gotd_imsg_have {
221 	uint8_t object_id[SHA1_DIGEST_LENGTH];
222 	uint32_t client_id;
223 } __attribute__((__packed__));
224 
225 /* Structure for GOTD_IMSG_ACK data. */
226 struct gotd_imsg_ack {
227 	uint8_t object_id[SHA1_DIGEST_LENGTH];
228 	uint32_t client_id;
229 } __attribute__((__packed__));
230 
231 /* Structure for GOTD_IMSG_NAK data. */
232 struct gotd_imsg_nak {
233 	uint8_t object_id[SHA1_DIGEST_LENGTH];
234 	uint32_t client_id;
235 } __attribute__((__packed__));
236 
237 /* Structure for GOTD_IMSG_PACKFILE_STATUS data. */
238 struct gotd_imsg_packfile_status {
239 	size_t reason_len;
240 
241 	/* Followed by reason_len data bytes. */
242 } __attribute__((__packed__));
243 
244 
245 /* Structure for GOTD_IMSG_REF_UPDATE data. */
246 struct gotd_imsg_ref_update {
247 	uint8_t old_id[SHA1_DIGEST_LENGTH];
248 	uint8_t new_id[SHA1_DIGEST_LENGTH];
249 	int ref_is_new;
250 	uint32_t client_id;
251 	size_t name_len;
252 
253 	/* Followed by name_len data bytes. */
254 } __attribute__((__packed__));
255 
256 /* Structure for GOTD_IMSG_REF_UPDATES_START data. */
257 struct gotd_imsg_ref_updates_start {
258 	int nref_updates;
259 	uint32_t client_id;
260 
261 	/* Followed by nref_updates GOT_IMSG_REF_UPDATE_OK/NG messages. */
262 };
263 
264 /* Structure for GOTD_IMSG_REF_UPDATE_OK data. */
265 struct gotd_imsg_ref_update_ok {
266 	uint8_t old_id[SHA1_DIGEST_LENGTH];
267 	uint8_t new_id[SHA1_DIGEST_LENGTH];
268 	int ref_is_new;
269 	uint32_t client_id;
270 	size_t name_len;
271 
272 	/* Followed by name_len data bytes. */
273 } __attribute__((__packed__));
274 
275 /* Structure for GOTD_IMSG_REF_UPDATE_NG data. */
276 struct gotd_imsg_ref_update_ng {
277 	uint8_t old_id[SHA1_DIGEST_LENGTH];
278 	uint8_t new_id[SHA1_DIGEST_LENGTH];
279 	uint32_t client_id;
280 	size_t name_len;
281 	size_t reason_len;
282 
283 	/* Followed by name_len + reason_len data bytes. */
284 } __attribute__((__packed__));
285 
286 /* Structure for GOTD_IMSG_SEND_PACKFILE data. */
287 struct gotd_imsg_send_packfile {
288 	uint32_t client_id;
289 	int report_progress;
290 
291 	/* delta cache file is sent as a file descriptor */
292 
293 	/* followed by two GOTD_IMSG_PACKFILE_PIPE messages */
294 };
295 
296 /* Structure for GOTD_IMSG_RECV_PACKFILE data. */
297 struct gotd_imsg_recv_packfile {
298 	uint32_t client_id;
299 	int report_status;
300 
301 	/* pack destination temp file is sent as a file descriptor */
302 };
303 
304 /* Structure for GOTD_IMSG_PACKFILE_PIPE data. */
305 struct gotd_imsg_packfile_pipe {
306 	uint32_t client_id;
307 };
308 
309 /* Structure for GOTD_IMSG_PACKIDX_FILE data. */
310 struct gotd_imsg_packidx_file {
311 	uint32_t client_id;
312 };
313 
314 
315 /*
316  * Structure for GOTD_IMSG_PACKFILE_PROGRESS and
317  * GOTD_IMSG_PACKFILE_READY data.
318  */
319 struct gotd_imsg_packfile_progress {
320 	uint32_t client_id;
321 	int ncolored;
322 	int nfound;
323 	int ntrees;
324 	off_t packfile_size;
325 	int ncommits;
326 	int nobj_total;
327 	int nobj_deltify;
328 	int nobj_written;
329 };
330 
331 /* Structure for GOTD_IMSG_PACKFILE_INSTALL. */
332 struct gotd_imsg_packfile_install {
333 	uint32_t client_id;
334 	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
335 };
336 
337 /* Structure for GOTD_IMSG_PACKFILE_DONE data. */
338 struct gotd_imsg_packfile_done {
339 	uint32_t client_id;
340 };
341 
342 /* Structure for GOTD_IMSG_DISCONNECT data. */
343 struct gotd_imsg_disconnect {
344 	uint32_t client_id;
345 };
346 
347 int parse_config(const char *, enum gotd_procid, struct gotd *);
348 
349 /* imsg.c */
350 const struct got_error *gotd_imsg_flush(struct imsgbuf *);
351 const struct got_error *gotd_imsg_recv(struct imsg *, struct imsgbuf *, size_t);
352 const struct got_error *gotd_imsg_poll_recv(struct imsg *, struct imsgbuf *,
353     size_t);
354 const struct got_error *gotd_imsg_recv_error(uint32_t *client_id,
355     struct imsg *imsg);
356 int gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t, uint32_t,
357     const struct got_error *);
358 int gotd_imsg_send_error_event(struct gotd_imsgev *, uint32_t, uint32_t,
359     const struct got_error *);
360 void gotd_imsg_event_add(struct gotd_imsgev *);
361 int gotd_imsg_compose_event(struct gotd_imsgev *, uint16_t, uint32_t, int,
362     void *, uint16_t);
363 int gotd_imsg_forward(struct gotd_imsgev *, struct imsg *, int);
364 
365 void gotd_imsg_send_ack(struct got_object_id *, struct imsgbuf *,
366     uint32_t, pid_t);
367 void gotd_imsg_send_nak(struct got_object_id *, struct imsgbuf *,
368     uint32_t, pid_t);