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