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1 /*-
2  * Copyright (c) 2011 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 #include <sys/param.h>
30 #include <sys/queue.h>
31 #include <sys/sbuf.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <assert.h>
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <grp.h>
38 #include <inttypes.h>
39 #include <pwd.h>
40 #include <stdarg.h>
41 #include <stdbool.h>
42 #include <stddef.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <strings.h>
47 #include <unistd.h>
48
49 #include "makefs.h"
50
51 #define IS_DOT(nm)      ((nm)[0] == '.' && (nm)[1] == '\0')
52 #define IS_DOTDOT(nm)   ((nm)[0] == '.' && (nm)[1] == '.' && (nm)[2] == '\0')
53
54 struct mtree_fileinfo {
55         SLIST_ENTRY(mtree_fileinfo) next;
56         FILE *fp;
57         const char *name;
58         u_int line;
59 };
60
61 /* Global state used while parsing. */
62 static SLIST_HEAD(, mtree_fileinfo) mtree_fileinfo =
63     SLIST_HEAD_INITIALIZER(mtree_fileinfo);
64 static fsnode *mtree_root;
65 static fsnode *mtree_current;
66 static fsnode mtree_global;
67 static fsinode mtree_global_inode;
68 static u_int errors, warnings;
69
70 static void mtree_error(const char *, ...) __printflike(1, 2);
71 static void mtree_warning(const char *, ...) __printflike(1, 2);
72
73 static int
74 mtree_file_push(const char *name, FILE *fp)
75 {
76         struct mtree_fileinfo *fi;
77
78         fi = malloc(sizeof(*fi));
79         if (fi == NULL)
80                 return (ENOMEM);
81
82         if (strcmp(name, "-") == 0)
83                 fi->name = strdup("(stdin)");
84         else
85                 fi->name = strdup(name);
86         if (fi->name == NULL) {
87                 free(fi);
88                 return (ENOMEM);
89         }
90
91         fi->fp = fp;
92         fi->line = 0;
93
94         SLIST_INSERT_HEAD(&mtree_fileinfo, fi, next);
95         return (0);
96 }
97
98 static void
99 mtree_print(const char *msgtype, const char *fmt, va_list ap)
100 {
101         struct mtree_fileinfo *fi;
102
103         if (msgtype != NULL) {
104                 fi = SLIST_FIRST(&mtree_fileinfo);
105                 if (fi != NULL)
106                         fprintf(stderr, "%s:%u: ", fi->name, fi->line);
107                 fprintf(stderr, "%s: ", msgtype);
108         }
109         vfprintf(stderr, fmt, ap);
110 }
111
112 static void
113 mtree_error(const char *fmt, ...)
114 {
115         va_list ap;
116
117         va_start(ap, fmt);
118         mtree_print("error", fmt, ap);
119         va_end(ap);
120
121         errors++;
122         fputc('\n', stderr);
123 }
124
125 static void
126 mtree_warning(const char *fmt, ...)
127 {
128         va_list ap;
129
130         va_start(ap, fmt);
131         mtree_print("warning", fmt, ap);
132         va_end(ap);
133
134         warnings++;
135         fputc('\n', stderr);
136 }
137
138 #ifndef MAKEFS_MAX_TREE_DEPTH
139 # define MAKEFS_MAX_TREE_DEPTH (MAXPATHLEN/2)
140 #endif
141
142 /* construct path to node->name */
143 static char *
144 mtree_file_path(fsnode *node)
145 {
146         fsnode *pnode;
147         struct sbuf *sb;
148         char *res, *rp[MAKEFS_MAX_TREE_DEPTH];
149         int depth;
150
151         depth = 0;
152         rp[depth] = node->name;
153         for (pnode = node->parent; pnode && depth < MAKEFS_MAX_TREE_DEPTH;
154              pnode = pnode->parent) {
155                 if (strcmp(pnode->name, ".") == 0)
156                         break;
157                 rp[++depth] = pnode->name;
158         }
159         
160         sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND);
161         if (sb == NULL) {
162                 errno = ENOMEM;
163                 return (NULL);
164         }
165         while (depth > 0) {
166                 sbuf_cat(sb, rp[depth--]);
167                 sbuf_putc(sb, '/');
168         }
169         sbuf_cat(sb, rp[depth]);
170         sbuf_finish(sb);
171         res = strdup(sbuf_data(sb));
172         sbuf_delete(sb);
173         if (res == NULL)
174                 errno = ENOMEM;
175         return res;
176
177 }
178
179 /* mtree_resolve() sets errno to indicate why NULL was returned. */
180 static char *
181 mtree_resolve(const char *spec, int *istemp)
182 {
183         struct sbuf *sb;
184         char *res, *var;
185         const char *base, *p, *v;
186         size_t len;
187         int c, error, quoted, subst;
188
189         len = strlen(spec);
190         if (len == 0) {
191                 errno = EINVAL;
192                 return (NULL);
193         }
194
195         c = (len > 1) ? (spec[0] == spec[len - 1]) ? spec[0] : 0 : 0;
196         *istemp = (c == '`') ? 1 : 0;
197         subst = (c == '`' || c == '"') ? 1 : 0;
198         quoted = (subst || c == '\'') ? 1 : 0;
199
200         if (!subst) {
201                 res = strdup(spec + quoted);
202                 if (res != NULL && quoted)
203                         res[len - 2] = '\0';
204                 return (res);
205         }
206
207         sb = sbuf_new_auto();
208         if (sb == NULL) {
209                 errno = ENOMEM;
210                 return (NULL);
211         }
212
213         base = spec + 1;
214         len -= 2;
215         error = 0;
216         while (len > 0) {
217                 p = strchr(base, '$');
218                 if (p == NULL) {
219                         sbuf_bcat(sb, base, len);
220                         base += len;
221                         len = 0;
222                         continue;
223                 }
224                 /* The following is safe. spec always starts with a quote. */
225                 if (p[-1] == '\\')
226                         p--;
227                 if (base != p) {
228                         sbuf_bcat(sb, base, p - base);
229                         len -= p - base;
230                         base = p;
231                 }
232                 if (*p == '\\') {
233                         sbuf_putc(sb, '$');
234                         base += 2;
235                         len -= 2;
236                         continue;
237                 }
238                 /* Skip the '$'. */
239                 base++;
240                 len--;
241                 /* Handle ${X} vs $X. */
242                 v = base;
243                 if (*base == '{') {
244                         p = strchr(v, '}');
245                         if (p == NULL)
246                                 p = v;
247                 } else
248                         p = v;
249                 len -= (p + 1) - base;
250                 base = p + 1;
251
252                 if (v == p) {
253                         sbuf_putc(sb, *v);
254                         continue;
255                 }
256
257                 error = ENOMEM;
258                 var = calloc(p - v, 1);
259                 if (var == NULL)
260                         break;
261
262                 memcpy(var, v + 1, p - v - 1);
263                 if (strcmp(var, ".CURDIR") == 0) {
264                         res = getcwd(NULL, 0);
265                         if (res == NULL)
266                                 break;
267                 } else if (strcmp(var, ".PROG") == 0) {
268                         res = strdup(getprogname());
269                         if (res == NULL)
270                                 break;
271                 } else {
272                         v = getenv(var);
273                         if (v != NULL) {
274                                 res = strdup(v);
275                                 if (res == NULL)
276                                         break;
277                         } else
278                                 res = NULL;
279                 }
280                 error = 0;
281
282                 if (res != NULL) {
283                         sbuf_cat(sb, res);
284                         free(res);
285                 }
286                 free(var);
287         }
288
289         sbuf_finish(sb);
290         res = (error == 0) ? strdup(sbuf_data(sb)) : NULL;
291         sbuf_delete(sb);
292         if (res == NULL)
293                 errno = ENOMEM;
294         return (res);
295 }
296
297 static int
298 skip_over(FILE *fp, const char *cs)
299 {
300         int c;
301
302         c = getc(fp);
303         while (c != EOF && strchr(cs, c) != NULL)
304                 c = getc(fp);
305         if (c != EOF) {
306                 ungetc(c, fp);
307                 return (0);
308         }
309         return (ferror(fp) ? errno : -1);
310 }
311
312 static int
313 skip_to(FILE *fp, const char *cs)
314 {
315         int c;
316
317         c = getc(fp);
318         while (c != EOF && strchr(cs, c) == NULL)
319                 c = getc(fp);
320         if (c != EOF) {
321                 ungetc(c, fp);
322                 return (0);
323         }
324         return (ferror(fp) ? errno : -1);
325 }
326
327 static int
328 read_word(FILE *fp, char *buf, size_t bufsz)
329 {
330         struct mtree_fileinfo *fi;
331         size_t idx, qidx;
332         int c, done, error, esc, qlvl;
333
334         if (bufsz == 0)
335                 return (EINVAL);
336
337         done = 0;
338         esc = 0;
339         idx = 0;
340         qidx = -1;
341         qlvl = 0;
342         do {
343                 c = getc(fp);
344                 switch (c) {
345                 case EOF:
346                         buf[idx] = '\0';
347                         error = ferror(fp) ? errno : -1;
348                         if (error == -1)
349                                 mtree_error("unexpected end of file");
350                         return (error);
351                 case '\\':
352                         esc++;
353                         if (esc == 1)
354                                 continue;
355                         break;
356                 case '`':
357                 case '\'':
358                 case '"':
359                         if (esc)
360                                 break;
361                         if (qlvl == 0) {
362                                 qlvl++;
363                                 qidx = idx;
364                         } else if (c == buf[qidx]) {
365                                 qlvl--;
366                                 if (qlvl > 0) {
367                                         do {
368                                                 qidx--;
369                                         } while (buf[qidx] != '`' &&
370                                             buf[qidx] != '\'' &&
371                                             buf[qidx] != '"');
372                                 } else
373                                         qidx = -1;
374                         } else {
375                                 qlvl++;
376                                 qidx = idx;
377                         }
378                         break;
379                 case ' ':
380                 case '\t':
381                 case '\n':
382                         if (!esc && qlvl == 0) {
383                                 ungetc(c, fp);
384                                 c = '\0';
385                                 done = 1;
386                                 break;
387                         }
388                         if (c == '\n') {
389                                 /*
390                                  * We going to eat the newline ourselves.
391                                  */
392                                 if (qlvl > 0)
393                                         mtree_warning("quoted word straddles "
394                                             "onto next line.");
395                                 fi = SLIST_FIRST(&mtree_fileinfo);
396                                 fi->line++;
397                         }
398                         break;
399                 case 'a':
400                         if (esc)
401                                 c = '\a';
402                         break;
403                 case 'b':
404                         if (esc)
405                                 c = '\b';
406                         break;
407                 case 'f':
408                         if (esc)
409                                 c = '\f';
410                         break;
411                 case 'n':
412                         if (esc)
413                                 c = '\n';
414                         break;
415                 case 'r':
416                         if (esc)
417                                 c = '\r';
418                         break;
419                 case 't':
420                         if (esc)
421                                 c = '\t';
422                         break;
423                 case 'v':
424                         if (esc)
425                                 c = '\v';
426                         break;
427                 }
428                 buf[idx++] = c;
429                 esc = 0;
430         } while (idx < bufsz && !done);
431
432         if (idx >= bufsz) {
433                 mtree_error("word too long to fit buffer (max %zu characters)",
434                     bufsz);
435                 skip_to(fp, " \t\n");
436         }
437         return (0);
438 }
439
440 static fsnode *
441 create_node(const char *name, u_int type, fsnode *parent, fsnode *global)
442 {
443         fsnode *n;
444
445         n = calloc(1, sizeof(*n));
446         if (n == NULL)
447                 return (NULL);
448
449         n->name = strdup(name);
450         if (n->name == NULL) {
451                 free(n);
452                 return (NULL);
453         }
454
455         n->type = (type == 0) ? global->type : type;
456         n->parent = parent;
457
458         n->inode = calloc(1, sizeof(*n->inode));
459         if (n->inode == NULL) {
460                 free(n->name);
461                 free(n);
462                 return (NULL);
463         }
464
465         /* Assign global options/defaults. */
466         bcopy(global->inode, n->inode, sizeof(*n->inode));
467         n->inode->st.st_mode = (n->inode->st.st_mode & ~S_IFMT) | n->type;
468
469         if (n->type == S_IFLNK)
470                 n->symlink = global->symlink;
471         else if (n->type == S_IFREG)
472                 n->contents = global->contents;
473
474         return (n);
475 }
476
477 static void
478 destroy_node(fsnode *n)
479 {
480
481         assert(n != NULL);
482         assert(n->name != NULL);
483         assert(n->inode != NULL);
484
485         free(n->inode);
486         free(n->name);
487         free(n);
488 }
489
490 static int
491 read_number(const char *tok, u_int base, intmax_t *res, intmax_t min,
492     intmax_t max)
493 {
494         char *end;
495         intmax_t val;
496
497         val = strtoimax(tok, &end, base);
498         if (end == tok || end[0] != '\0')
499                 return (EINVAL);
500         if (val < min || val > max)
501                 return (EDOM);
502         *res = val;
503         return (0);
504 }
505
506 static int
507 read_mtree_keywords(FILE *fp, fsnode *node)
508 {
509         char keyword[PATH_MAX];
510         char *name, *p, *value;
511         gid_t gid;
512         uid_t uid;
513         struct stat *st, sb;
514         intmax_t num;
515         u_long flset, flclr;
516         int error, istemp, type;
517
518         st = &node->inode->st;
519         do {
520                 error = skip_over(fp, " \t");
521                 if (error)
522                         break;
523
524                 error = read_word(fp, keyword, sizeof(keyword));
525                 if (error)
526                         break;
527
528                 if (keyword[0] == '\0')
529                         break;
530
531                 value = strchr(keyword, '=');
532                 if (value != NULL)
533                         *value++ = '\0';
534
535                 /*
536                  * We use EINVAL, ENOATTR, ENOSYS and ENXIO to signal
537                  * certain conditions:
538                  *   EINVAL -   Value provided for a keyword that does
539                  *              not take a value. The value is ignored.
540                  *   ENOATTR -  Value missing for a keyword that needs
541                  *              a value. The keyword is ignored.
542                  *   ENOSYS -   Unsupported keyword encountered. The
543                  *              keyword is ignored.
544                  *   ENXIO -    Value provided for a keyword that does
545                  *              not take a value. The value is ignored.
546                  */
547                 switch (keyword[0]) {
548                 case 'c':
549                         if (strcmp(keyword, "contents") == 0) {
550                                 if (value == NULL) {
551                                         error = ENOATTR;
552                                         break;
553                                 }
554                                 node->contents = strdup(value);
555                         } else
556                                 error = ENOSYS;
557                         break;
558                 case 'f':
559                         if (strcmp(keyword, "flags") == 0) {
560                                 if (value == NULL) {
561                                         error = ENOATTR;
562                                         break;
563                                 }
564                                 flset = flclr = 0;
565                                 if (!strtofflags(&value, &flset, &flclr)) {
566                                         st->st_flags &= ~flclr;
567                                         st->st_flags |= flset;
568                                 } else
569                                         error = errno;
570                         } else
571                                 error = ENOSYS;
572                         break;
573                 case 'g':
574                         if (strcmp(keyword, "gid") == 0) {
575                                 if (value == NULL) {
576                                         error = ENOATTR;
577                                         break;
578                                 }
579                                 error = read_number(value, 10, &num,
580                                     0, UINT_MAX);
581                                 if (!error)
582                                         st->st_gid = num;
583                         } else if (strcmp(keyword, "gname") == 0) {
584                                 if (value == NULL) {
585                                         error = ENOATTR;
586                                         break;
587                                 }
588                                 if (gid_from_group(value, &gid) == 0)
589                                         st->st_gid = gid;
590                                 else
591                                         error = EINVAL;
592                         } else
593                                 error = ENOSYS;
594                         break;
595                 case 'l':
596                         if (strcmp(keyword, "link") == 0) {
597                                 if (value == NULL) {
598                                         error = ENOATTR;
599                                         break;
600                                 }
601                                 node->symlink = strdup(value);
602                         } else
603                                 error = ENOSYS;
604                         break;
605                 case 'm':
606                         if (strcmp(keyword, "mode") == 0) {
607                                 if (value == NULL) {
608                                         error = ENOATTR;
609                                         break;
610                                 }
611                                 if (value[0] >= '0' && value[0] <= '9') {
612                                         error = read_number(value, 8, &num,
613                                             0, 07777);
614                                         if (!error) {
615                                                 st->st_mode &= S_IFMT;
616                                                 st->st_mode |= num;
617                                         }
618                                 } else {
619                                         /* Symbolic mode not supported. */
620                                         error = EINVAL;
621                                         break;
622                                 }
623                         } else
624                                 error = ENOSYS;
625                         break;
626                 case 'o':
627                         if (strcmp(keyword, "optional") == 0) {
628                                 if (value != NULL)
629                                         error = ENXIO;
630                                 node->flags |= FSNODE_F_OPTIONAL;
631                         } else
632                                 error = ENOSYS;
633                         break;
634                 case 's':
635                         if (strcmp(keyword, "size") == 0) {
636                                 if (value == NULL) {
637                                         error = ENOATTR;
638                                         break;
639                                 }
640                                 error = read_number(value, 10, &num,
641                                     0, INTMAX_MAX);
642                                 if (!error)
643                                         st->st_size = num;
644                         } else
645                                 error = ENOSYS;
646                         break;
647                 case 't':
648                         if (strcmp(keyword, "time") == 0) {
649                                 if (value == NULL) {
650                                         error = ENOATTR;
651                                         break;
652                                 }
653                                 p = strchr(value, '.');
654                                 if (p != NULL)
655                                         *p++ = '\0';
656                                 error = read_number(value, 10, &num, 0,
657                                     INTMAX_MAX);
658                                 if (error)
659                                         break;
660                                 st->st_atime = num;
661                                 st->st_ctime = num;
662                                 st->st_mtime = num;
663                                 error = read_number(p, 10, &num, 0,
664                                     INTMAX_MAX);
665                                 if (error)
666                                         break;
667                                 if (num != 0)
668                                         error = EINVAL;
669                         } else if (strcmp(keyword, "type") == 0) {
670                                 if (value == NULL) {
671                                         error = ENOATTR;
672                                         break;
673                                 }
674                                 if (strcmp(value, "dir") == 0)
675                                         node->type = S_IFDIR;
676                                 else if (strcmp(value, "file") == 0)
677                                         node->type = S_IFREG;
678                                 else if (strcmp(value, "link") == 0)
679                                         node->type = S_IFLNK;
680                                 else
681                                         error = EINVAL;
682                         } else
683                                 error = ENOSYS;
684                         break;
685                 case 'u':
686                         if (strcmp(keyword, "uid") == 0) {
687                                 if (value == NULL) {
688                                         error = ENOATTR;
689                                         break;
690                                 }
691                                 error = read_number(value, 10, &num,
692                                     0, UINT_MAX);
693                                 if (!error)
694                                         st->st_uid = num;
695                         } else if (strcmp(keyword, "uname") == 0) {
696                                 if (value == NULL) {
697                                         error = ENOATTR;
698                                         break;
699                                 }
700                                 if (uid_from_user(value, &uid) == 0)
701                                         st->st_uid = uid;
702                                 else
703                                         error = EINVAL;
704                         } else
705                                 error = ENOSYS;
706                         break;
707                 default:
708                         error = ENOSYS;
709                         break;
710                 }
711
712                 switch (error) {
713                 case EINVAL:
714                         mtree_error("%s: invalid value '%s'", keyword, value);
715                         break;
716                 case ENOATTR:
717                         mtree_error("%s: keyword needs a value", keyword);
718                         break;
719                 case ENOSYS:
720                         mtree_warning("%s: unsupported keyword", keyword);
721                         break;
722                 case ENXIO:
723                         mtree_error("%s: keyword does not take a value",
724                             keyword);
725                         break;
726                 }
727         } while (1);
728
729         if (error)
730                 return (error);
731
732         st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
733
734         /* Nothing more to do for the global defaults. */
735         if (node->name == NULL)
736                 return (0);
737
738         /*
739          * Be intelligent about the file type.
740          */
741         if (node->contents != NULL) {
742                 if (node->symlink != NULL) {
743                         mtree_error("%s: both link and contents keywords "
744                             "defined", node->name);
745                         return (0);
746                 }
747                 type = S_IFREG;
748         } else if (node->type != 0) {
749                 type = node->type;
750                 if (type == S_IFREG) {
751                         /* the named path is the default contents */
752                         node->contents = mtree_file_path(node);
753                 }
754         } else
755                 type = (node->symlink != NULL) ? S_IFLNK : S_IFDIR;
756
757         if (node->type == 0)
758                 node->type = type;
759
760         if (node->type != type) {
761                 mtree_error("%s: file type and defined keywords to not match",
762                     node->name);
763                 return (0);
764         }
765
766         st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
767
768         if (node->contents == NULL)
769                 return (0);
770
771         name = mtree_resolve(node->contents, &istemp);
772         if (name == NULL)
773                 return (errno);
774
775         if (stat(name, &sb) != 0) {
776                 mtree_error("%s: contents file '%s' not found", node->name,
777                     name);
778                 free(name);
779                 return (0);
780         }
781
782         /*
783          * Check for hardlinks. If the contents key is used, then the check
784          * will only trigger if the contents file is a link even if it is used
785          * by more than one file
786          */
787         if (sb.st_nlink > 1) {
788                 fsinode *curino;
789
790                 st->st_ino = sb.st_ino;
791                 st->st_dev = sb.st_dev;
792                 curino = link_check(node->inode);
793                 if (curino != NULL) {
794                         free(node->inode);
795                         node->inode = curino;
796                         node->inode->nlink++;
797                 }
798         }
799
800         free(node->contents);
801         node->contents = name;
802         st->st_size = sb.st_size;
803         return (0);
804 }
805
806 static int
807 read_mtree_command(FILE *fp)
808 {
809         char cmd[10];
810         int error;
811
812         error = read_word(fp, cmd, sizeof(cmd));
813         if (error)
814                 goto out;
815
816         error = read_mtree_keywords(fp, &mtree_global);
817
818  out:
819         skip_to(fp, "\n");
820         (void)getc(fp);
821         return (error);
822 }
823
824 static int
825 read_mtree_spec1(FILE *fp, bool def, const char *name)
826 {
827         fsnode *last, *node, *parent;
828         u_int type;
829         int error;
830
831         assert(name[0] != '\0');
832
833         /*
834          * Treat '..' specially, because it only changes our current
835          * directory. We don't create a node for it. We simply ignore
836          * any keywords that may appear on the line as well.
837          * Going up a directory is a little non-obvious. A directory
838          * node has a corresponding '.' child. The parent of '.' is
839          * not the '.' node of the parent directory, but the directory
840          * node within the parent to which the child relates. However,
841          * going up a directory means we need to find the '.' node to
842          * which the directoy node is linked.  This we can do via the
843          * first * pointer, because '.' is always the first entry in a
844          * directory.
845          */
846         if (IS_DOTDOT(name)) {
847                 /* This deals with NULL pointers as well. */
848                 if (mtree_current == mtree_root) {
849                         mtree_warning("ignoring .. in root directory");
850                         return (0);
851                 }
852
853                 node = mtree_current;
854
855                 assert(node != NULL);
856                 assert(IS_DOT(node->name));
857                 assert(node->first == node);
858
859                 /* Get the corresponding directory node in the parent. */
860                 node = mtree_current->parent;
861
862                 assert(node != NULL);
863                 assert(!IS_DOT(node->name));
864
865                 node = node->first;
866
867                 assert(node != NULL);
868                 assert(IS_DOT(node->name));
869                 assert(node->first == node);
870
871                 mtree_current = node;
872                 return (0);
873         }
874
875         /*
876          * If we don't have a current directory and the first specification
877          * (either implicit or defined) is not '.', then we need to create
878          * a '.' node first (using a recursive call).
879          */
880         if (!IS_DOT(name) && mtree_current == NULL) {
881                 error = read_mtree_spec1(fp, false, ".");
882                 if (error)
883                         return (error);
884         }
885
886         /*
887          * Lookup the name in the current directory (if we have a current
888          * directory) to make sure we do not create multiple nodes for the
889          * same component. For non-definitions, if we find a node with the
890          * same name, simply change the current directory. For definitions
891          * more happens.
892          */
893         last = NULL;
894         node = mtree_current;
895         while (node != NULL) {
896                 assert(node->first == mtree_current);
897
898                 if (strcmp(name, node->name) == 0) {
899                         if (def == true) {
900                                 if (!dupsok)
901                                         mtree_error(
902                                             "duplicate definition of %s",
903                                             name);
904                                 else
905                                         mtree_warning(
906                                             "duplicate definition of %s",
907                                             name);
908                                 return (0);
909                         }
910
911                         if (node->type != S_IFDIR) {
912                                 mtree_error("%s is not a directory", name);
913                                 return (0);
914                         }
915
916                         assert(!IS_DOT(name));
917
918                         node = node->child;
919
920                         assert(node != NULL);
921                         assert(IS_DOT(node->name));
922
923                         mtree_current = node;
924                         return (0);
925                 }
926
927                 last = node;
928                 node = last->next;
929         }
930
931         parent = (mtree_current != NULL) ? mtree_current->parent : NULL;
932         type = (def == false || IS_DOT(name)) ? S_IFDIR : 0;
933         node = create_node(name, type, parent, &mtree_global);
934         if (node == NULL)
935                 return (ENOMEM);
936
937         if (def == true) {
938                 error = read_mtree_keywords(fp, node);
939                 if (error) {
940                         destroy_node(node);
941                         return (error);
942                 }
943         }
944
945         node->first = (mtree_current != NULL) ? mtree_current : node;
946
947         if (last != NULL)
948                 last->next = node;
949
950         if (node->type != S_IFDIR)
951                 return (0);
952
953         if (!IS_DOT(node->name)) {
954                 parent = node;
955                 node = create_node(".", S_IFDIR, parent, parent);
956                 if (node == NULL) {
957                         last->next = NULL;
958                         destroy_node(parent);
959                         return (ENOMEM);
960                 }
961                 parent->child = node;
962                 node->first = node;
963         }
964
965         assert(node != NULL);
966         assert(IS_DOT(node->name));
967         assert(node->first == node);
968
969         mtree_current = node;
970         if (mtree_root == NULL)
971                 mtree_root = node;
972
973         return (0);
974 }
975
976 static int
977 read_mtree_spec(FILE *fp)
978 {
979         char pathspec[PATH_MAX];
980         char *cp;
981         int error;
982
983         error = read_word(fp, pathspec, sizeof(pathspec));
984         if (error)
985                 goto out;
986
987         cp = strchr(pathspec, '/');
988         if (cp != NULL) {
989                 /* Absolute pathname */
990                 mtree_current = mtree_root;
991
992                 do {
993                         *cp++ = '\0';
994
995                         /* Disallow '..' as a component. */
996                         if (IS_DOTDOT(pathspec)) {
997                                 mtree_error("absolute path cannot contain "
998                                     ".. component");
999                                 goto out;
1000                         }
1001
1002                         /* Ignore multiple adjacent slashes and '.'. */
1003                         if (pathspec[0] != '\0' && !IS_DOT(pathspec))
1004                                 error = read_mtree_spec1(fp, false, pathspec);
1005                         memmove(pathspec, cp, strlen(cp) + 1);
1006                         cp = strchr(pathspec, '/');
1007                 } while (!error && cp != NULL);
1008
1009                 /* Disallow '.' and '..' as the last component. */
1010                 if (!error && (IS_DOT(pathspec) || IS_DOTDOT(pathspec))) {
1011                         mtree_error("absolute path cannot contain . or .. "
1012                             "components");
1013                         goto out;
1014                 }
1015         }
1016
1017         /* Ignore absolute specfications that end with a slash. */
1018         if (!error && pathspec[0] != '\0')
1019                 error = read_mtree_spec1(fp, true, pathspec);
1020
1021  out:
1022         skip_to(fp, "\n");
1023         (void)getc(fp);
1024         return (error);
1025 }
1026
1027 fsnode *
1028 read_mtree(const char *fname, fsnode *node)
1029 {
1030         struct mtree_fileinfo *fi;
1031         FILE *fp;
1032         int c, error;
1033
1034         /* We do not yet support nesting... */
1035         assert(node == NULL);
1036
1037         if (strcmp(fname, "-") == 0)
1038                 fp = stdin;
1039         else {
1040                 fp = fopen(fname, "r");
1041                 if (fp == NULL)
1042                         err(1, "Can't open `%s'", fname);
1043         }
1044
1045         error = mtree_file_push(fname, fp);
1046         if (error)
1047                 goto out;
1048
1049         bzero(&mtree_global, sizeof(mtree_global));
1050         bzero(&mtree_global_inode, sizeof(mtree_global_inode));
1051         mtree_global.inode = &mtree_global_inode;
1052         mtree_global_inode.nlink = 1;
1053         mtree_global_inode.st.st_nlink = 1;
1054         mtree_global_inode.st.st_atime = mtree_global_inode.st.st_ctime =
1055             mtree_global_inode.st.st_mtime = time(NULL);
1056         errors = warnings = 0;
1057
1058         setgroupent(1);
1059         setpassent(1);
1060
1061         mtree_root = node;
1062         mtree_current = node;
1063         do {
1064                 /* Start of a new line... */
1065                 fi = SLIST_FIRST(&mtree_fileinfo);
1066                 fi->line++;
1067
1068                 error = skip_over(fp, " \t");
1069                 if (error)
1070                         break;
1071
1072                 c = getc(fp);
1073                 if (c == EOF) {
1074                         error = ferror(fp) ? errno : -1;
1075                         break;
1076                 }
1077
1078                 switch (c) {
1079                 case '\n':              /* empty line */
1080                         error = 0;
1081                         break;
1082                 case '#':               /* comment -- skip to end of line. */
1083                         error = skip_to(fp, "\n");
1084                         if (!error)
1085                                 (void)getc(fp);
1086                         break;
1087                 case '/':               /* special commands */
1088                         error = read_mtree_command(fp);
1089                         break;
1090                 default:                /* specification */
1091                         ungetc(c, fp);
1092                         error = read_mtree_spec(fp);
1093                         break;
1094                 }
1095         } while (!error);
1096
1097         endpwent();
1098         endgrent();
1099
1100         if (error <= 0 && (errors || warnings)) {
1101                 warnx("%u error(s) and %u warning(s) in mtree manifest",
1102                     errors, warnings);
1103                 if (errors)
1104                         exit(1);
1105         }
1106
1107  out:
1108         if (error > 0)
1109                 errc(1, error, "Error reading mtree file");
1110
1111         if (fp != stdin)
1112                 fclose(fp);
1113
1114         if (mtree_root != NULL)
1115                 return (mtree_root);
1116
1117         /* Handle empty specifications. */
1118         node = create_node(".", S_IFDIR, NULL, &mtree_global);
1119         node->first = node;
1120         return (node);
1121 }