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Date:: Tue Sep 21 20:34:22 2021 UTC
Message:: portable: initial Linux compilation This commit modifies the GoT main branch to be able to compile it under linux.
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1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  * Copyright (c) 2015 Theo de Raadt <deraadt@openbsd.org>
4  * Copyright (c) 1997 Todd C. Miller <millert@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/stat.h>
20 
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <limits.h>
24 #include <libgen.h>
25 #include <stdlib.h>
26 #include <unistd.h>
27 #include <stdio.h>
28 #include <string.h>
29 #include <dirent.h>
30 #include <paths.h>
31 
32 #include "got_compat.h"
33 
34 #include "got_error.h"
35 #include "got_path.h"
36 
37 #ifndef MIN
38 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
39 #endif
40 
41 int
42 got_path_is_absolute(const char *path)
43 {
44 	return path[0] == '/';
45 }
46 
47 /* based on canonpath() from kern_pledge.c */
48 const struct got_error *
49 got_canonpath(const char *input, char *buf, size_t bufsize)
50 {
51 	const char *p;
52 	char *q;
53 
54 	/* can't canon relative paths, don't bother */
55 	if (!got_path_is_absolute(input)) {
56 		if (strlcpy(buf, input, bufsize) >= bufsize)
57 			return got_error(GOT_ERR_NO_SPACE);
58 		return NULL;
59 	}
60 
61 	p = input;
62 	q = buf;
63 	while (*p && (q - buf < bufsize)) {
64 		if (p[0] == '/' && (p[1] == '/' || p[1] == '\0')) {
65 			p += 1;
66 
67 		} else if (p[0] == '/' && p[1] == '.' &&
68 		    (p[2] == '/' || p[2] == '\0')) {
69 			p += 2;
70 
71 		} else if (p[0] == '/' && p[1] == '.' && p[2] == '.' &&
72 		    (p[3] == '/' || p[3] == '\0')) {
73 			p += 3;
74 			if (q != buf)	/* "/../" at start of buf */
75 				while (*--q != '/')
76 					continue;
77 
78 		} else {
79 			*q++ = *p++;
80 		}
81 	}
82 	if ((*p == '\0') && (q - buf < bufsize)) {
83 		*q = 0;
84 		return NULL;
85 	} else
86 		return got_error(GOT_ERR_NO_SPACE);
87 }
88 
89 const struct got_error *
90 got_path_skip_common_ancestor(char **child, const char *parent_abspath,
91     const char *abspath)
92 {
93 	const struct got_error *err = NULL;
94 	size_t len_parent, len, bufsize;
95 
96 	*child = NULL;
97 
98 	len_parent = strlen(parent_abspath);
99 	len = strlen(abspath);
100 	if (len_parent >= len)
101 		return got_error_path(abspath, GOT_ERR_BAD_PATH);
102 	if (strncmp(parent_abspath, abspath, len_parent) != 0)
103 		return got_error_path(abspath, GOT_ERR_BAD_PATH);
104 	if (!got_path_is_root_dir(parent_abspath) && abspath[len_parent] != '/')
105 		return got_error_path(abspath, GOT_ERR_BAD_PATH);
106 	while (abspath[len_parent] == '/')
107 		abspath++;
108 	bufsize = len - len_parent + 1;
109 	*child = malloc(bufsize);
110 	if (*child == NULL)
111 		return got_error_from_errno("malloc");
112 	if (strlcpy(*child, abspath + len_parent, bufsize) >= bufsize) {
113 		err = got_error_from_errno("strlcpy");
114 		free(*child);
115 		*child = NULL;
116 		return err;
117 	}
118 	return NULL;
119 }
120 
121 int
122 got_path_is_root_dir(const char *path)
123 {
124 	while (*path == '/')
125 		path++;
126 	return (*path == '\0');
127 }
128 
129 int
130 got_path_is_current_dir(const char *path)
131 {
132 	return (path[0] == '.' && path[1] == '\0');
133 }
134 
135 int
136 got_path_is_child(const char *child, const char *parent, size_t parent_len)
137 {
138 	if (parent_len == 0 || got_path_is_root_dir(parent))
139 		return 1;
140 
141 	if (strncmp(parent, child, parent_len) != 0)
142 		return 0;
143 	if (child[parent_len] != '/')
144 		return 0;
145 
146 	return 1;
147 }
148 
149 int
150 got_path_cmp(const char *path1, const char *path2, size_t len1, size_t len2)
151 {
152 	size_t min_len;
153 	size_t i = 0;
154 
155 	/* Leading directory separators are insignificant. */
156 	while (path1[0] == '/') {
157 		path1++;
158 		len1--;
159 	}
160 	while (path2[0] == '/') {
161 		path2++;
162 		len2--;
163 	}
164 
165 	min_len = MIN(len1, len2);
166 
167 	/* Skip over common prefix. */
168 	while (i < min_len && path1[i] == path2[i])
169 		i++;
170 
171 	/* Are the paths exactly equal (besides path separators)? */
172 	if (len1 == len2 && i >= min_len)
173 		return 0;
174 
175 	/* Skip over redundant trailing path seperators. */
176 	while (path1[i] == '/' && path1[i + 1] == '/')
177 		path1++;
178 	while (path2[i] == '/' && path2[i + 1] == '/')
179 		path2++;
180 
181 	/* Trailing path separators are insignificant. */
182 	if (path1[i] == '/' && path1[i + 1] == '\0' && path2[i] == '\0')
183 		return 0;
184 	if (path2[i] == '/' && path2[i + 1] == '\0' && path1[i] == '\0')
185 		return 0;
186 
187 	/* Order children in subdirectories directly after their parents. */
188 	if (path1[i] == '/' && path2[i] == '\0')
189 		return 1;
190 	if (path2[i] == '/' && path1[i] == '\0')
191 		return -1;
192 	if (path1[i] == '/' && path2[i] != '\0')
193 		return -1;
194 	if (path2[i] == '/' && path1[i] != '\0')
195 		return 1;
196 
197 	/* Next character following the common prefix determines order. */
198 	return (unsigned char)path1[i] < (unsigned char)path2[i] ? -1 : 1;
199 }
200 
201 const struct got_error *
202 got_pathlist_insert(struct got_pathlist_entry **inserted,
203     struct got_pathlist_head *pathlist, const char *path, void *data)
204 {
205 	struct got_pathlist_entry *new, *pe;
206 
207 	if (inserted)
208 		*inserted = NULL;
209 
210 	new = malloc(sizeof(*new));
211 	if (new == NULL)
212 		return got_error_from_errno("malloc");
213 	new->path = path;
214 	new->path_len = strlen(path);
215 	new->data = data;
216 
217 	/*
218 	 * Many callers will provide paths in a somewhat sorted order while
219 	 * constructing a path list from inputs such as tree objects or
220 	 * dirents. Iterating backwards from the tail of the list should
221 	 * be more efficient than traversing through the entire list each
222 	 * time an element is inserted.
223 	 */
224 	pe = TAILQ_LAST(pathlist, got_pathlist_head);
225 	while (pe) {
226 		int cmp = got_path_cmp(pe->path, new->path,
227 		    pe->path_len, new->path_len);
228 		if (cmp == 0) {
229 			free(new); /* duplicate */
230 			return NULL;
231 		} else if (cmp < 0) {
232 			TAILQ_INSERT_AFTER(pathlist, pe, new, entry);
233 			if (inserted)
234 				*inserted = new;
235 			return NULL;
236 		}
237 		pe = TAILQ_PREV(pe, got_pathlist_head, entry);
238 	}
239 
240 	TAILQ_INSERT_HEAD(pathlist, new, entry);
241 	if (inserted)
242 		*inserted = new;
243 	return NULL;
244 }
245 
246 const struct got_error *
247 got_pathlist_append(struct got_pathlist_head *pathlist,
248     const char *path, void *data)
249 {
250 	struct got_pathlist_entry *new;
251 
252 	new = malloc(sizeof(*new));
253 	if (new == NULL)
254 		return got_error_from_errno("malloc");
255 	new->path = path;
256 	new->path_len = strlen(path);
257 	new->data = data;
258 	TAILQ_INSERT_TAIL(pathlist, new, entry);
259 	return NULL;
260 }
261 
262 void
263 got_pathlist_free(struct got_pathlist_head *pathlist)
264 {
265 	struct got_pathlist_entry *pe;
266 
267 	while ((pe = TAILQ_FIRST(pathlist)) != NULL) {
268 		TAILQ_REMOVE(pathlist, pe, entry);
269 		free(pe);
270 	}
271 }
272 
273 static const struct got_error *
274 make_parent_dirs(const char *abspath)
275 {
276 	const struct got_error *err = NULL;
277 	char *parent;
278 
279 	err = got_path_dirname(&parent, abspath);
280 	if (err)
281 		return err;
282 
283 	if (mkdir(parent, GOT_DEFAULT_DIR_MODE) == -1) {
284 		if (errno == ENOENT) {
285 			err = make_parent_dirs(parent);
286 			if (err)
287 				goto done;
288 			if (mkdir(parent, GOT_DEFAULT_DIR_MODE) == -1) {
289 				err = got_error_from_errno2("mkdir", parent);
290 				goto done;
291 			}
292 		} else
293 			err = got_error_from_errno2("mkdir", parent);
294 	}
295 done:
296 	free(parent);
297 	return err;
298 }
299 
300 const struct got_error *
301 got_path_mkdir(const char *abspath)
302 {
303 	const struct got_error *err = NULL;
304 
305 	if (mkdir(abspath, GOT_DEFAULT_DIR_MODE) == -1) {
306 		if (errno == ENOENT) {
307 			err = make_parent_dirs(abspath);
308 			if (err)
309 				goto done;
310 			if (mkdir(abspath, GOT_DEFAULT_DIR_MODE) == -1)
311 				err = got_error_from_errno2("mkdir", abspath);
312 		} else
313 			err = got_error_from_errno2("mkdir", abspath);
314 	}
315 
316 done:
317 	return err;
318 }
319 
320 int
321 got_path_dir_is_empty(const char *dir)
322 {
323 	DIR *d;
324 	struct dirent *dent;
325 	int empty = 1;
326 
327 	d = opendir(dir);
328 	if (d == NULL)
329 		return 1;
330 
331 	while ((dent = readdir(d)) != NULL) {
332 		if (strcmp(dent->d_name, ".") == 0 ||
333 		    strcmp(dent->d_name, "..") == 0)
334 			continue;
335 
336 		empty = 0;
337 		break;
338 	}
339 
340 	closedir(d);
341 	return empty;
342 }
343 
344 const struct got_error *
345 got_path_dirname(char **parent, const char *path)
346 {
347 	char buf[PATH_MAX];
348 	char *p;
349 
350 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
351 		return got_error(GOT_ERR_NO_SPACE);
352 
353 	p = dirname(buf);
354 	if (p == NULL)
355 		return got_error_from_errno2("dirname", path);
356 
357 	if (p[0] == '.' && p[1] == '\0')
358 		return got_error_path(path, GOT_ERR_BAD_PATH);
359 
360 	*parent = strdup(p);
361 	if (*parent == NULL)
362 		return got_error_from_errno("strdup");
363 
364 	return NULL;
365 }
366 
367 const struct got_error *
368 got_path_dirent_type(int *type, const char *path_parent, struct dirent *dent)
369 {
370 	const struct got_error *err = NULL;
371 	char *path_child;
372 	struct stat sb;
373 
374 	if (dent->d_type != DT_UNKNOWN) {
375 		*type = dent->d_type;
376 		return NULL;
377 	}
378 
379 	*type = DT_UNKNOWN;
380 
381 	/*
382 	 * This is a fallback to accommodate filesystems which do not
383 	 * provide directory entry type information. DT_UNKNOWN directory
384 	 * entries occur on NFS mounts without "readdir plus" RPC.
385 	 */
386 
387 	if (asprintf(&path_child, "%s/%s", path_parent, dent->d_name) == -1)
388 		return got_error_from_errno("asprintf");
389 
390 	if (lstat(path_child, &sb) == -1) {
391 		err = got_error_from_errno2("lstat", path_child);
392 		goto done;
393 	}
394 
395 	if (S_ISFIFO(sb.st_mode))
396 		*type = DT_FIFO;
397 	else if (S_ISCHR(sb.st_mode))
398 		*type = DT_CHR;
399 	else if (S_ISDIR(sb.st_mode))
400 		*type = DT_DIR;
401 	else if (S_ISBLK(sb.st_mode))
402 		*type = DT_BLK;
403 	else if (S_ISLNK(sb.st_mode))
404 		*type = DT_LNK;
405 	else if (S_ISREG(sb.st_mode))
406 		*type = DT_REG;
407 	else if (S_ISSOCK(sb.st_mode))
408 		*type = DT_SOCK;
409 done:
410 	free(path_child);
411 	return err;
412 }
413 
414 const struct got_error *
415 got_path_basename(char **s, const char *path)
416 {
417 	char buf[PATH_MAX];
418 	char *base;
419 
420 	if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf))
421 		return got_error(GOT_ERR_NO_SPACE);
422 
423 	base = basename(buf);
424 	if (base == NULL)
425 		return got_error_from_errno2("basename", path);
426 
427 	*s = strdup(base);
428 	if (*s == NULL)
429 		return got_error_from_errno("strdup");
430 
431 	return NULL;
432 }
433 
434 void
435 got_path_strip_trailing_slashes(char *path)
436 {
437 	size_t x;
438 
439 	x = strlen(path);
440 	while (x-- > 0 && path[x] == '/')
441 		path[x] = '\0';
442 }
443 
444 /* based on findprog() from usr.sbin/which/which.c */
445 const struct got_error *
446 got_path_find_prog(char **filename, const char *prog)
447 {
448 	const struct got_error *err = NULL;
449 	char *p;
450 	int len;
451 	struct stat sbuf;
452 	char *path, *pathcpy;
453 
454 	*filename = NULL;
455 
456 	path = getenv("PATH");
457 	if (path == NULL)
458 		path = _PATH_DEFPATH;
459 
460 	/* Special case if prog contains '/' */
461 	if (strchr(prog, '/')) {
462 		if ((stat(prog, &sbuf) == 0) && S_ISREG(sbuf.st_mode) &&
463 		    access(prog, X_OK) == 0) {
464 			*filename = strdup(prog);
465 			if (*filename == NULL)
466 				return got_error_from_errno("strdup");
467 		}
468 		return NULL;
469 	}
470 
471 	if ((path = strdup(path)) == NULL)
472 		return got_error_from_errno("strdup");
473 	pathcpy = path;
474 
475 	while ((p = strsep(&pathcpy, ":")) != NULL) {
476 		if (*p == '\0')
477 			p = ".";
478 
479 		len = strlen(p);
480 		while (len > 0 && p[len-1] == '/')
481 			p[--len] = '\0';	/* strip trailing '/' */
482 
483 		if (asprintf(filename, "%s/%s", p, prog) == -1) {
484 			err = got_error_from_errno("asprintf");
485 			break;
486 		}
487 		if ((stat(*filename, &sbuf) == 0) && S_ISREG(sbuf.st_mode) &&
488 		    access(*filename, X_OK) == 0)
489 			break;
490 		free(*filename);
491 		*filename = NULL;
492 		continue;
493 	}
494 	free(path);
495 	return err;
496 }
497 
498 const struct got_error *
499 got_path_create_file(const char *path, const char *content)
500 {
501 	const struct got_error *err = NULL;
502 	int fd = -1;
503 
504 	fd = open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW,
505 	    GOT_DEFAULT_FILE_MODE);
506 	if (fd == -1) {
507 		err = got_error_from_errno2("open", path);
508 		goto done;
509 	}
510 
511 	if (content) {
512 		int len = dprintf(fd, "%s\n", content);
513 		if (len != strlen(content) + 1) {
514 			err = got_error_from_errno("dprintf");
515 			goto done;
516 		}
517 	}
518 
519 done:
520 	if (fd != -1 && close(fd) == -1 && err == NULL)
521 		err = got_error_from_errno("close");
522 	return err;
523 }