1 /*
2  * Copyright (c) 2019 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 #include <sys/types.h>
18 #include <sys/queue.h>
19 #include <sys/uio.h>
20 #include <sys/time.h>
21 
22 #include <stdint.h>
23 #include <imsg.h>
24 #include <limits.h>
25 #include <signal.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sha1.h>
30 #include <sha2.h>
31 #include <unistd.h>
32 #include <zlib.h>
33 
34 #include "got_error.h"
35 #include "got_object.h"
36 #include "got_repository.h"
37 
38 #include "got_lib_delta.h"
39 #include "got_lib_object.h"
40 #include "got_lib_privsep.h"
41 #include "got_lib_gitconfig.h"
42 
43 static volatile sig_atomic_t sigint_received;
44 
45 static void
46 catch_sigint(int signo)
47 {
48 	sigint_received = 1;
49 }
50 
51 static const struct got_error *
52 send_gitconfig_int(struct imsgbuf *ibuf, int value)
53 {
54 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_INT_VAL, 0, 0, -1,
55 	    &value, sizeof(value)) == -1)
56 		return got_error_from_errno("imsg_compose GITCONFIG_INT_VAL");
57 
58 	return got_privsep_flush_imsg(ibuf);
59 }
60 
61 static const struct got_error *
62 gitconfig_num_request(struct imsgbuf *ibuf, struct got_gitconfig *gitconfig,
63     const char *section, const char *tag, int def)
64 {
65 	int value;
66 
67 	if (gitconfig == NULL)
68 		return got_error(GOT_ERR_PRIVSEP_MSG);
69 
70 	value = got_gitconfig_get_num(gitconfig, section, tag, def);
71 	return send_gitconfig_int(ibuf, value);
72 }
73 
74 static const struct got_error *
75 send_gitconfig_str(struct imsgbuf *ibuf, const char *value)
76 {
77 	size_t len = value ? strlen(value) : 0;
78 
79 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_STR_VAL, 0, 0, -1,
80 	    value, len) == -1)
81 		return got_error_from_errno("imsg_compose GITCONFIG_STR_VAL");
82 
83 	return got_privsep_flush_imsg(ibuf);
84 }
85 
86 static const struct got_error *
87 send_gitconfig_pair(struct imsgbuf *ibuf, const char *key, const char *val)
88 {
89 	struct ibuf *wbuf;
90 	size_t klen = key ? strlen(key) : 0;
91 	size_t vlen = val ? strlen(val) : 0;
92 	size_t tot = sizeof(klen) + sizeof(vlen) + klen + vlen;
93 
94 	if (tot > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
95 		return got_error(GOT_ERR_NO_SPACE);
96 
97 	wbuf = imsg_create(ibuf, GOT_IMSG_GITCONFIG_PAIR, 0, 0, tot);
98 	if (wbuf == NULL)
99 		return got_error_from_errno("imsg_create GITCONFIG_PAIR");
100 
101 	/* Keep in sync with got_imsg_gitconfig_pair */
102 	if (imsg_add(wbuf, &klen, sizeof(klen)) == -1)
103 		return got_error_from_errno("imsg_add GITCONFIG_PAIR");
104 	if (imsg_add(wbuf, &vlen, sizeof(vlen)) == -1)
105 		return got_error_from_errno("imsg_add GITCONFIG_PAIR");
106 	if (imsg_add(wbuf, key, klen) == -1)
107 		return got_error_from_errno("imsg_add GITCONFIG_PAIR");
108 	if (imsg_add(wbuf, val, vlen) == -1)
109 		return got_error_from_errno("imsg_add GITCONFIG_PAIR");
110 
111 	wbuf->fd = -1;
112 	imsg_close(ibuf, wbuf);
113 	return got_privsep_flush_imsg(ibuf);
114 }
115 
116 static const struct got_error *
117 gitconfig_str_request(struct imsgbuf *ibuf, struct got_gitconfig *gitconfig,
118     const char *section, const char *tag)
119 {
120 	char *value;
121 
122 	if (gitconfig == NULL)
123 		return got_error(GOT_ERR_PRIVSEP_MSG);
124 
125 	value = got_gitconfig_get_str(gitconfig, section, tag);
126 	return send_gitconfig_str(ibuf, value);
127 }
128 
129 static const struct got_error *
130 send_gitconfig_remotes(struct imsgbuf *ibuf, struct got_remote_repo *remotes,
131     int nremotes)
132 {
133 	const struct got_error *err = NULL;
134 	struct got_imsg_remotes iremotes;
135 	int i;
136 
137 	iremotes.nremotes = nremotes;
138 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_REMOTES, 0, 0, -1,
139 	    &iremotes, sizeof(iremotes)) == -1)
140 		return got_error_from_errno("imsg_compose GITCONFIG_REMOTES");
141 
142 	err = got_privsep_flush_imsg(ibuf);
143 	imsg_clear(ibuf);
144 	if (err)
145 		return err;
146 
147 	for (i = 0; i < nremotes; i++) {
148 		struct got_imsg_remote iremote;
149 		size_t len = sizeof(iremote);
150 		struct ibuf *wbuf;
151 
152 		iremote.mirror_references = remotes[i].mirror_references;
153 		iremote.name_len = strlen(remotes[i].name);
154 		len += iremote.name_len;
155 		iremote.fetch_url_len = strlen(remotes[i].fetch_url);
156 		len += iremote.fetch_url_len;
157 		iremote.send_url_len = strlen(remotes[i].send_url);
158 		len += iremote.send_url_len;
159 
160 		wbuf = imsg_create(ibuf, GOT_IMSG_GITCONFIG_REMOTE, 0, 0, len);
161 		if (wbuf == NULL)
162 			return got_error_from_errno(
163 			    "imsg_create GITCONFIG_REMOTE");
164 
165 		if (imsg_add(wbuf, &iremote, sizeof(iremote)) == -1)
166 			return got_error_from_errno(
167 			    "imsg_add GITCONFIG_REMOTE");
168 
169 		if (imsg_add(wbuf, remotes[i].name, iremote.name_len) == -1)
170 			return got_error_from_errno(
171 			    "imsg_add GITCONFIG_REMOTE");
172 		if (imsg_add(wbuf, remotes[i].fetch_url, iremote.fetch_url_len) == -1)
173 			return got_error_from_errno(
174 			    "imsg_add GITCONFIG_REMOTE");
175 		if (imsg_add(wbuf, remotes[i].send_url, iremote.send_url_len) == -1)
176 			return got_error_from_errno(
177 			    "imsg_add GITCONFIG_REMOTE");
178 
179 		wbuf->fd = -1;
180 		imsg_close(ibuf, wbuf);
181 		err = got_privsep_flush_imsg(ibuf);
182 		if (err)
183 			return err;
184 	}
185 
186 	return NULL;
187 }
188 
189 static int
190 get_boolean_val(char *val)
191 {
192     return (strcasecmp(val, "true") == 0 ||
193 	strcasecmp(val, "on") == 0 ||
194 	strcasecmp(val, "yes") == 0 ||
195 	strcmp(val, "1") == 0);
196 }
197 
198 static int
199 skip_node(struct got_gitconfig *gitconfig, struct got_gitconfig_list_node *node)
200 {
201 	/*
202 	 * Skip config nodes which do not describe remotes, and remotes
203 	 * which do not have a fetch URL defined (as used by git-annex).
204 	 */
205 	return (strncasecmp("remote \"", node->field, 8) != 0 ||
206 	    got_gitconfig_get_str(gitconfig, node->field, "url") == NULL);
207 }
208 
209 static const struct got_error *
210 gitconfig_remotes_request(struct imsgbuf *ibuf, struct got_gitconfig *gitconfig)
211 {
212 	const struct got_error *err = NULL;
213 	struct got_gitconfig_list *sections;
214 	struct got_gitconfig_list_node *node;
215 	struct got_remote_repo *remotes = NULL;
216 	int nremotes = 0, i;
217 
218 	if (gitconfig == NULL)
219 		return got_error(GOT_ERR_PRIVSEP_MSG);
220 
221 	err = got_gitconfig_get_section_list(&sections, gitconfig);
222 	if (err)
223 		return err;
224 
225 	TAILQ_FOREACH(node, &sections->fields, link) {
226 		if (skip_node(gitconfig, node))
227 			continue;
228 		nremotes++;
229 	}
230 
231 	if (nremotes == 0) {
232 		err = send_gitconfig_remotes(ibuf, NULL, 0);
233 		goto done;
234 	}
235 
236 	remotes = recallocarray(NULL, 0, nremotes, sizeof(*remotes));
237 	if (remotes == NULL) {
238 		err = got_error_from_errno("recallocarray");
239 		goto done;
240 	}
241 
242 	i = 0;
243 	TAILQ_FOREACH(node, &sections->fields, link) {
244 		char *name, *end, *mirror;
245 
246 		if (skip_node(gitconfig, node))
247 			continue;
248 
249 		name = strdup(node->field + 8);
250 		if (name == NULL) {
251 			err = got_error_from_errno("strdup");
252 			goto done;
253 		}
254 		end = strrchr(name, '"');
255 		if (end)
256 			*end = '\0';
257 		remotes[i].name = name;
258 
259 		remotes[i].fetch_url = got_gitconfig_get_str(gitconfig,
260 		    node->field, "url");
261 
262 		remotes[i].send_url = got_gitconfig_get_str(gitconfig,
263 		    node->field, "pushurl");
264 		if (remotes[i].send_url == NULL)
265 			remotes[i].send_url = remotes[i].fetch_url;
266 
267 		remotes[i].mirror_references = 0;
268 		mirror = got_gitconfig_get_str(gitconfig, node->field,
269 		    "mirror");
270 		if (mirror != NULL && get_boolean_val(mirror))
271 			remotes[i].mirror_references = 1;
272 
273 		i++;
274 	}
275 
276 	err = send_gitconfig_remotes(ibuf, remotes, nremotes);
277 done:
278 	for (i = 0; i < nremotes; i++)
279 		free(remotes[i].name);
280 	free(remotes);
281 	got_gitconfig_free_list(sections);
282 	return err;
283 }
284 
285 static const struct got_error *
286 gitconfig_owner_request(struct imsgbuf *ibuf, struct got_gitconfig *gitconfig)
287 {
288 	char *value;
289 
290 	if (gitconfig == NULL)
291 		return got_error(GOT_ERR_PRIVSEP_MSG);
292 
293 	value = got_gitconfig_get_str(gitconfig, "gotweb", "owner");
294 	if (value)
295 		return send_gitconfig_str(ibuf, value);
296 	value = got_gitconfig_get_str(gitconfig, "gitweb", "owner");
297 	return send_gitconfig_str(ibuf, value);
298 }
299 
300 static const struct got_error *
301 gitconfig_extensions_request(struct imsgbuf *ibuf,
302     struct got_gitconfig *gitconfig)
303 {
304 	const struct got_error *err = NULL;
305 	struct got_gitconfig_list *tags;
306 	struct got_gitconfig_list_node *node;
307 	int nextensions = 0;
308 	char *val;
309 
310 	if (gitconfig == NULL)
311 		return got_error(GOT_ERR_PRIVSEP_MSG);
312 
313 	tags = got_gitconfig_get_tag_list(gitconfig, "extensions");
314 	if (tags == NULL)
315 		return send_gitconfig_int(ibuf, 0);
316 
317 	TAILQ_FOREACH(node, &tags->fields, link)
318 		nextensions++;
319 
320 	err = send_gitconfig_int(ibuf, nextensions);
321 	if (err)
322 		goto done;
323 
324 	TAILQ_FOREACH(node, &tags->fields, link) {
325 		val = got_gitconfig_get_str(gitconfig, "extensions",
326 		    node->field);
327 		err = send_gitconfig_pair(ibuf, node->field, val);
328 		if (err)
329 			goto done;
330 	}
331 done:
332 	got_gitconfig_free_list(tags);
333 	return err;
334 }
335 
336 int
337 main(int argc, char *argv[])
338 {
339 	const struct got_error *err = NULL;
340 	struct imsgbuf ibuf;
341 	size_t datalen;
342 	struct got_gitconfig *gitconfig = NULL;
343 #if 0
344 	static int attached;
345 
346 	while (!attached)
347 		sleep(1);
348 #endif
349 	signal(SIGINT, catch_sigint);
350 
351 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
352 
353 #ifndef PROFILE
354 	/* revoke access to most system calls */
355 	if (pledge("stdio recvfd", NULL) == -1) {
356 		err = got_error_from_errno("pledge");
357 		got_privsep_send_error(&ibuf, err);
358 		return 1;
359 	}
360 #endif
361 
362 	for (;;) {
363 		struct imsg imsg;
364 
365 		memset(&imsg, 0, sizeof(imsg));
366 		imsg.fd = -1;
367 
368 		if (sigint_received) {
369 			err = got_error(GOT_ERR_CANCELLED);
370 			break;
371 		}
372 
373 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
374 		if (err) {
375 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
376 				err = NULL;
377 			break;
378 		}
379 
380 		if (imsg.hdr.type == GOT_IMSG_STOP)
381 			break;
382 
383 		switch (imsg.hdr.type) {
384 		case GOT_IMSG_GITCONFIG_PARSE_REQUEST:
385 			datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
386 			if (datalen != 0) {
387 				err = got_error(GOT_ERR_PRIVSEP_LEN);
388 				break;
389 			}
390 			if (imsg.fd == -1){
391 				err = got_error(GOT_ERR_PRIVSEP_NO_FD);
392 				break;
393 			}
394 
395 			if (gitconfig)
396 				got_gitconfig_close(gitconfig);
397 			err = got_gitconfig_open(&gitconfig, imsg.fd);
398 			break;
399 		case GOT_IMSG_GITCONFIG_REPOSITORY_FORMAT_VERSION_REQUEST:
400 			err = gitconfig_num_request(&ibuf, gitconfig, "core",
401 			    "repositoryformatversion", 0);
402 			break;
403 		case GOT_IMSG_GITCONFIG_REPOSITORY_EXTENSIONS_REQUEST:
404 			err = gitconfig_extensions_request(&ibuf, gitconfig);
405 			break;
406 		case GOT_IMSG_GITCONFIG_AUTHOR_NAME_REQUEST:
407 			err = gitconfig_str_request(&ibuf, gitconfig, "user",
408 			    "name");
409 			break;
410 		case GOT_IMSG_GITCONFIG_AUTHOR_EMAIL_REQUEST:
411 			err = gitconfig_str_request(&ibuf, gitconfig, "user",
412 			    "email");
413 			break;
414 		case GOT_IMSG_GITCONFIG_REMOTES_REQUEST:
415 			err = gitconfig_remotes_request(&ibuf, gitconfig);
416 			break;
417 		case GOT_IMSG_GITCONFIG_OWNER_REQUEST:
418 			err = gitconfig_owner_request(&ibuf, gitconfig);
419 			break;
420 		default:
421 			err = got_error(GOT_ERR_PRIVSEP_MSG);
422 			break;
423 		}
424 
425 		if (imsg.fd != -1) {
426 			if (close(imsg.fd) == -1 && err == NULL)
427 				err = got_error_from_errno("close");
428 		}
429 
430 		imsg_free(&imsg);
431 		if (err)
432 			break;
433 	}
434 
435 	imsg_clear(&ibuf);
436 	if (err) {
437 		if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
438 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
439 			got_privsep_send_error(&ibuf, err);
440 		}
441 	}
442 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
443 		err = got_error_from_errno("close");
444 	return err ? 1 : 0;
445 }