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