1#define _BSD_SOURCE
  2#include <glob.h>
  3#include <fnmatch.h>
  4#include <sys/stat.h>
  5#include <dirent.h>
  6#include <limits.h>
  7#include <string.h>
  8#include <stdlib.h>
  9#include <errno.h>
 10#include <stddef.h>
 11#include <unistd.h>
 12#ifdef __wasilibc_unmodified_upstream // WASI has no usernames
 13#include <pwd.h>
 14#endif
 15
 16struct match
 17{
 18	struct match *next;
 19	char name[];
 20};
 21
 22static int append(struct match **tail, const char *name, size_t len, int mark)
 23{
 24	struct match *new = malloc(sizeof(struct match) + len + 2);
 25	if (!new) return -1;
 26	(*tail)->next = new;
 27	new->next = NULL;
 28	memcpy(new->name, name, len+1);
 29	if (mark && len && name[len-1]!='/') {
 30		new->name[len] = '/';
 31		new->name[len+1] = 0;
 32	}
 33	*tail = new;
 34	return 0;
 35}
 36
 37static int do_glob(char *buf, size_t pos, int type, char *pat, int flags, int (*errfunc)(const char *path, int err), struct match **tail)
 38{
 39	/* If GLOB_MARK is unused, we don't care about type. */
 40	if (!type && !(flags & GLOB_MARK)) type = DT_REG;
 41
 42	/* Special-case the remaining pattern being all slashes, in
 43	 * which case we can use caller-passed type if it's a dir. */
 44	if (*pat && type!=DT_DIR) type = 0;
 45	while (pos+1 < PATH_MAX && *pat=='/') buf[pos++] = *pat++;
 46
 47	/* Consume maximal [escaped-]literal prefix of pattern, copying
 48	 * and un-escaping it to the running buffer as we go. */
 49	ptrdiff_t i=0, j=0;
 50	int in_bracket = 0, overflow = 0;
 51	for (; pat[i]!='*' && pat[i]!='?' && (!in_bracket || pat[i]!=']'); i++) {
 52		if (!pat[i]) {
 53			if (overflow) return 0;
 54			pat += i;
 55			pos += j;
 56			i = j = 0;
 57			break;
 58		} else if (pat[i] == '[') {
 59			in_bracket = 1;
 60		} else if (pat[i] == '\\' && !(flags & GLOB_NOESCAPE)) {
 61			/* Backslashes inside a bracket are (at least by
 62			 * our interpretation) non-special, so if next
 63			 * char is ']' we have a complete expression. */
 64			if (in_bracket && pat[i+1]==']') break;
 65			/* Unpaired final backslash never matches. */
 66			if (!pat[i+1]) return 0;
 67			i++;
 68		}
 69		if (pat[i] == '/') {
 70			if (overflow) return 0;
 71			in_bracket = 0;
 72			pat += i+1;
 73			i = -1;
 74			pos += j+1;
 75			j = -1;
 76		}
 77		/* Only store a character if it fits in the buffer, but if
 78		 * a potential bracket expression is open, the overflow
 79		 * must be remembered and handled later only if the bracket
 80		 * is unterminated (and thereby a literal), so as not to
 81		 * disallow long bracket expressions with short matches. */
 82		if (pos+(j+1) < PATH_MAX) {
 83			buf[pos+j++] = pat[i];
 84		} else if (in_bracket) {
 85			overflow = 1;
 86		} else {
 87			return 0;
 88		}
 89		/* If we consume any new components, the caller-passed type
 90		 * or dummy type from above is no longer valid. */
 91		type = 0;
 92	}
 93	buf[pos] = 0;
 94	if (!*pat) {
 95		/* If we consumed any components above, or if GLOB_MARK is
 96		 * requested and we don't yet know if the match is a dir,
 97		 * we must confirm the file exists and/or determine its type.
 98		 *
 99		 * If marking dirs, symlink type is inconclusive; we need the
100		 * type for the symlink target, and therefore must try stat
101		 * first unless type is known not to be a symlink. Otherwise,
102		 * or if that fails, use lstat for determining existence to
103		 * avoid false negatives in the case of broken symlinks. */
104		struct stat st;
105		if ((flags & GLOB_MARK) && (!type||type==DT_LNK) && !stat(buf, &st)) {
106			if (S_ISDIR(st.st_mode)) type = DT_DIR;
107			else type = DT_REG;
108		}
109		if (!type && lstat(buf, &st)) {
110			if (errno!=ENOENT && (errfunc(buf, errno) || (flags & GLOB_ERR)))
111				return GLOB_ABORTED;
112			return 0;
113		}
114		if (append(tail, buf, pos, (flags & GLOB_MARK) && type==DT_DIR))
115			return GLOB_NOSPACE;
116		return 0;
117	}
118	char *p2 = strchr(pat, '/'), saved_sep = '/';
119	/* Check if the '/' was escaped and, if so, remove the escape char
120	 * so that it will not be unpaired when passed to fnmatch. */
121	if (p2 && !(flags & GLOB_NOESCAPE)) {
122		char *p;
123		for (p=p2; p>pat && p[-1]=='\\'; p--);
124		if ((p2-p)%2) {
125			p2--;
126			saved_sep = '\\';
127		}
128	}
129	DIR *dir = opendir(pos ? buf : ".");
130	if (!dir) {
131		if (errfunc(buf, errno) || (flags & GLOB_ERR))
132			return GLOB_ABORTED;
133		return 0;
134	}
135	int old_errno = errno;
136	struct dirent *de;
137	while (errno=0, de=readdir(dir)) {
138		/* Quickly skip non-directories when there's pattern left. */
139		if (p2 && de->d_type && de->d_type!=DT_DIR && de->d_type!=DT_LNK)
140			continue;
141
142		size_t l = strlen(de->d_name);
143		if (l >= PATH_MAX-pos) continue;
144
145		if (p2) *p2 = 0;
146
147		int fnm_flags= ((flags & GLOB_NOESCAPE) ? FNM_NOESCAPE : 0)
148			| ((!(flags & GLOB_PERIOD)) ? FNM_PERIOD : 0);
149
150		if (fnmatch(pat, de->d_name, fnm_flags))
151			continue;
152
153		/* With GLOB_PERIOD, don't allow matching . or .. unless
154		 * fnmatch would match them with FNM_PERIOD rules in effect. */
155		if (p2 && (flags & GLOB_PERIOD) && de->d_name[0]=='.'
156		    && (!de->d_name[1] || de->d_name[1]=='.' && !de->d_name[2])
157		    && fnmatch(pat, de->d_name, fnm_flags | FNM_PERIOD))
158			continue;
159
160		memcpy(buf+pos, de->d_name, l+1);
161		if (p2) *p2 = saved_sep;
162		int r = do_glob(buf, pos+l, de->d_type, p2 ? p2 : "", flags, errfunc, tail);
163		if (r) {
164			closedir(dir);
165			return r;
166		}
167	}
168	int readerr = errno;
169	if (p2) *p2 = saved_sep;
170	closedir(dir);
171	if (readerr && (errfunc(buf, errno) || (flags & GLOB_ERR)))
172		return GLOB_ABORTED;
173	errno = old_errno;
174	return 0;
175}
176
177static int ignore_err(const char *path, int err)
178{
179	return 0;
180}
181
182static void freelist(struct match *head)
183{
184	struct match *match, *next;
185	for (match=head->next; match; match=next) {
186		next = match->next;
187		free(match);
188	}
189}
190
191static int sort(const void *a, const void *b)
192{
193	return strcmp(*(const char **)a, *(const char **)b);
194}
195
196#ifdef __wasilibc_unmodified_upstream // WASI has no usernames
197static int expand_tilde(char **pat, char *buf, size_t *pos)
198{
199	char *p = *pat + 1;
200	size_t i = 0;
201
202	char delim, *name_end = __strchrnul(p, '/');
203	if ((delim = *name_end)) *name_end++ = 0;
204	*pat = name_end;
205
206	char *home = *p ? NULL : getenv("HOME");
207	if (!home) {
208		struct passwd pw, *res;
209		switch (*p ? getpwnam_r(p, &pw, buf, PATH_MAX, &res)
210			   : getpwuid_r(getuid(), &pw, buf, PATH_MAX, &res)) {
211		case ENOMEM:
212			return GLOB_NOSPACE;
213		case 0:
214			if (!res)
215		default:
216				return GLOB_NOMATCH;
217		}
218		home = pw.pw_dir;
219	}
220	while (i < PATH_MAX - 2 && *home)
221		buf[i++] = *home++;
222	if (*home)
223		return GLOB_NOMATCH;
224	if ((buf[i] = delim))
225		buf[++i] = 0;
226	*pos = i;
227	return 0;
228}
229#endif
230
231int glob(const char *restrict pat, int flags, int (*errfunc)(const char *path, int err), glob_t *restrict g)
232{
233	struct match head = { .next = NULL }, *tail = &head;
234	size_t cnt, i;
235	size_t offs = (flags & GLOB_DOOFFS) ? g->gl_offs : 0;
236	int error = 0;
237	char buf[PATH_MAX];
238	
239	if (!errfunc) errfunc = ignore_err;
240
241	if (!(flags & GLOB_APPEND)) {
242		g->gl_offs = offs;
243		g->gl_pathc = 0;
244		g->gl_pathv = NULL;
245	}
246
247	if (*pat) {
248		char *p = strdup(pat);
249		if (!p) return GLOB_NOSPACE;
250		buf[0] = 0;
251		size_t pos = 0;
252		char *s = p;
253#ifdef __wasilibc_unmodified_upstream // WASI has no usernames
254		if ((flags & (GLOB_TILDE | GLOB_TILDE_CHECK)) && *p == '~')
255			error = expand_tilde(&s, buf, &pos);
256#endif
257		if (!error)
258			error = do_glob(buf, pos, 0, s, flags, errfunc, &tail);
259		free(p);
260	}
261
262	if (error == GLOB_NOSPACE) {
263		freelist(&head);
264		return error;
265	}
266	
267	for (cnt=0, tail=head.next; tail; tail=tail->next, cnt++);
268	if (!cnt) {
269		if (flags & GLOB_NOCHECK) {
270			tail = &head;
271			if (append(&tail, pat, strlen(pat), 0))
272				return GLOB_NOSPACE;
273			cnt++;
274		} else if (!error)
275			return GLOB_NOMATCH;
276	}
277
278	if (flags & GLOB_APPEND) {
279		char **pathv = realloc(g->gl_pathv, (offs + g->gl_pathc + cnt + 1) * sizeof(char *));
280		if (!pathv) {
281			freelist(&head);
282			return GLOB_NOSPACE;
283		}
284		g->gl_pathv = pathv;
285		offs += g->gl_pathc;
286	} else {
287		g->gl_pathv = malloc((offs + cnt + 1) * sizeof(char *));
288		if (!g->gl_pathv) {
289			freelist(&head);
290			return GLOB_NOSPACE;
291		}
292		for (i=0; i<offs; i++)
293			g->gl_pathv[i] = NULL;
294	}
295	for (i=0, tail=head.next; i<cnt; tail=tail->next, i++)
296		g->gl_pathv[offs + i] = tail->name;
297	g->gl_pathv[offs + i] = NULL;
298	g->gl_pathc += cnt;
299
300	if (!(flags & GLOB_NOSORT))
301		qsort(g->gl_pathv+offs, cnt, sizeof(char *), sort);
302	
303	return error;
304}
305
306void globfree(glob_t *g)
307{
308	size_t i;
309	for (i=0; i<g->gl_pathc; i++)
310		free(g->gl_pathv[g->gl_offs + i] - offsetof(struct match, name));
311	free(g->gl_pathv);
312	g->gl_pathc = 0;
313	g->gl_pathv = NULL;
314}
315
316weak_alias(glob, glob64);
317weak_alias(globfree, globfree64);