spec.c revision 1.73
1/*	$NetBSD: spec.c,v 1.73 2009/04/07 18:06:41 apb Exp $	*/
2
3/*-
4 * Copyright (c) 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32/*-
33 * Copyright (c) 2001-2004 The NetBSD Foundation, Inc.
34 * All rights reserved.
35 *
36 * This code is derived from software contributed to The NetBSD Foundation
37 * by Luke Mewburn of Wasabi Systems.
38 *
39 * Redistribution and use in source and binary forms, with or without
40 * modification, are permitted provided that the following conditions
41 * are met:
42 * 1. Redistributions of source code must retain the above copyright
43 *    notice, this list of conditions and the following disclaimer.
44 * 2. Redistributions in binary form must reproduce the above copyright
45 *    notice, this list of conditions and the following disclaimer in the
46 *    documentation and/or other materials provided with the distribution.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
49 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
50 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
51 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
52 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
53 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
54 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
55 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
56 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
57 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
58 * POSSIBILITY OF SUCH DAMAGE.
59 */
60
61#if HAVE_NBTOOL_CONFIG_H
62#include "nbtool_config.h"
63#endif
64
65#include <sys/cdefs.h>
66#if defined(__RCSID) && !defined(lint)
67#if 0
68static char sccsid[] = "@(#)spec.c	8.2 (Berkeley) 4/28/95";
69#else
70__RCSID("$NetBSD: spec.c,v 1.73 2009/04/07 18:06:41 apb Exp $");
71#endif
72#endif /* not lint */
73
74#include <sys/param.h>
75#include <sys/stat.h>
76
77#include <ctype.h>
78#include <errno.h>
79#include <grp.h>
80#include <pwd.h>
81#include <stdio.h>
82#include <stdlib.h>
83#include <string.h>
84#include <unistd.h>
85#include <vis.h>
86#include <util.h>
87
88#include "extern.h"
89#include "pack_dev.h"
90
91size_t	mtree_lineno;			/* Current spec line number */
92int	mtree_Mflag;			/* Merge duplicate entries */
93int	mtree_Wflag;			/* Don't "whack" permissions */
94
95static	dev_t	parsedev(char *);
96static	void	replacenode(NODE *, NODE *);
97static	void	set(char *, NODE *);
98static	void	unset(char *, NODE *);
99static	void	addchild(NODE *, NODE *);
100static	int	nodecmp(const NODE *, const NODE *);
101
102#define REPLACEPTR(x,v)	do { if ((x)) free((x)); (x) = (v); } while (0)
103
104NODE *
105spec(FILE *fp)
106{
107	NODE *centry, *last, *pathparent, *cur;
108	char *p, *e, *next;
109	NODE ginfo, *root;
110	char *buf, *tname, *ntname;
111	size_t tnamelen, plen;
112
113	root = NULL;
114	centry = last = NULL;
115	tname = NULL;
116	tnamelen = 0;
117	memset(&ginfo, 0, sizeof(ginfo));
118	for (mtree_lineno = 0;
119	    (buf = fparseln(fp, NULL, &mtree_lineno, NULL,
120		FPARSELN_UNESCCOMM));
121	    free(buf)) {
122		/* Skip leading whitespace. */
123		for (p = buf; *p && isspace((unsigned char)*p); ++p)
124			continue;
125
126		/* If nothing but whitespace, continue. */
127		if (!*p)
128			continue;
129
130#ifdef DEBUG
131		fprintf(stderr, "line %lu: {%s}\n",
132		    (u_long)mtree_lineno, p);
133#endif
134		/* Grab file name, "$", "set", or "unset". */
135		next = buf;
136		while ((p = strsep(&next, " \t")) != NULL && *p == '\0')
137			continue;
138		if (p == NULL)
139			mtree_err("missing field");
140
141		if (p[0] == '/') {
142			if (strcmp(p + 1, "set") == 0)
143				set(next, &ginfo);
144			else if (strcmp(p + 1, "unset") == 0)
145				unset(next, &ginfo);
146			else
147				mtree_err("invalid specification `%s'", p);
148			continue;
149		}
150
151		if (strcmp(p, "..") == 0) {
152			/* Don't go up, if haven't gone down. */
153			if (root == NULL)
154				goto noparent;
155			if (last->type != F_DIR || last->flags & F_DONE) {
156				if (last == root)
157					goto noparent;
158				last = last->parent;
159			}
160			last->flags |= F_DONE;
161			continue;
162
163noparent:		mtree_err("no parent node");
164		}
165
166		plen = strlen(p) + 1;
167		if (plen > tnamelen) {
168			if ((ntname = realloc(tname, plen)) == NULL)
169				mtree_err("realloc: %s", strerror(errno));
170			tname = ntname;
171			tnamelen = plen;
172		}
173		if (strunvis(tname, p) == -1)
174			mtree_err("strunvis failed on `%s'", p);
175		p = tname;
176
177		pathparent = NULL;
178		if (strchr(p, '/') != NULL) {
179			cur = root;
180			for (; (e = strchr(p, '/')) != NULL; p = e+1) {
181				if (p == e)
182					continue;	/* handle // */
183				*e = '\0';
184				if (strcmp(p, ".") != 0) {
185					while (cur &&
186					    strcmp(cur->name, p) != 0) {
187						cur = cur->next;
188					}
189				}
190				if (cur == NULL || cur->type != F_DIR) {
191					mtree_err("%s: %s", tname,
192					    strerror(ENOENT));
193				}
194				*e = '/';
195				pathparent = cur;
196				cur = cur->child;
197			}
198			if (*p == '\0')
199				mtree_err("%s: empty leaf element", tname);
200		}
201
202		if ((centry = calloc(1, sizeof(NODE) + strlen(p))) == NULL)
203			mtree_err("%s", strerror(errno));
204		*centry = ginfo;
205		centry->lineno = mtree_lineno;
206		strcpy(centry->name, p);
207#define	MAGIC	"?*["
208		if (strpbrk(p, MAGIC))
209			centry->flags |= F_MAGIC;
210		set(next, centry);
211
212		if (root == NULL) {
213				/*
214				 * empty tree
215				 */
216			if (strcmp(centry->name, ".") != 0 ||
217			    centry->type != F_DIR)
218				mtree_err(
219				    "root node must be the directory `.'");
220			last = root = centry;
221			root->parent = root;
222		} else if (pathparent != NULL) {
223				/*
224				 * full path entry; add or replace
225				 */
226			centry->parent = pathparent;
227			addchild(pathparent, centry);
228			last = centry;
229		} else if (strcmp(centry->name, ".") == 0) {
230				/*
231				 * duplicate "." entry; always replace
232				 */
233			replacenode(root, centry);
234		} else if (last->type == F_DIR && !(last->flags & F_DONE)) {
235				/*
236				 * new relative child in current dir;
237				 * add or replace
238				 */
239			centry->parent = last;
240			addchild(last, centry);
241			last = centry;
242		} else {
243				/*
244				 * new relative child in parent dir
245				 * (after encountering ".." entry);
246				 * add or replace
247				 */
248			centry->parent = last->parent;
249			addchild(last->parent, centry);
250			last = centry;
251		}
252	}
253	return (root);
254}
255
256void
257free_nodes(NODE *root)
258{
259	NODE	*cur, *next;
260
261	if (root == NULL)
262		return;
263
264	next = NULL;
265	for (cur = root; cur != NULL; cur = next) {
266		next = cur->next;
267		free_nodes(cur->child);
268		REPLACEPTR(cur->slink, NULL);
269		REPLACEPTR(cur->md5digest, NULL);
270		REPLACEPTR(cur->rmd160digest, NULL);
271		REPLACEPTR(cur->sha1digest, NULL);
272		REPLACEPTR(cur->sha256digest, NULL);
273		REPLACEPTR(cur->sha384digest, NULL);
274		REPLACEPTR(cur->sha512digest, NULL);
275		REPLACEPTR(cur->tags, NULL);
276		REPLACEPTR(cur, NULL);
277	}
278}
279
280/*
281 * dump_nodes --
282 *	dump the NODEs from `cur', based in the directory `dir'.
283 *	if pathlast is none zero, print the path last, otherwise print
284 *	it first.
285 */
286void
287dump_nodes(const char *dir, NODE *root, int pathlast)
288{
289	NODE	*cur;
290	char	path[MAXPATHLEN];
291	const char *name;
292	char	*str;
293	char	*p, *q;
294
295	for (cur = root; cur != NULL; cur = cur->next) {
296		if (cur->type != F_DIR && !matchtags(cur))
297			continue;
298
299		if (snprintf(path, sizeof(path), "%s%s%s",
300		    dir, *dir ? "/" : "", cur->name)
301		    >= (int)sizeof(path))
302			mtree_err("Pathname too long.");
303
304		if (!pathlast)
305			printf("%s ", vispath(path));
306
307#define MATCHFLAG(f)	((keys & (f)) && (cur->flags & (f)))
308		if (MATCHFLAG(F_TYPE))
309			printf("type=%s ", nodetype(cur->type));
310		if (MATCHFLAG(F_UID | F_UNAME)) {
311			if (keys & F_UNAME &&
312			    (name = user_from_uid(cur->st_uid, 1)) != NULL)
313				printf("uname=%s ", name);
314			else
315				printf("uid=%u ", cur->st_uid);
316		}
317		if (MATCHFLAG(F_GID | F_GNAME)) {
318			if (keys & F_GNAME &&
319			    (name = group_from_gid(cur->st_gid, 1)) != NULL)
320				printf("gname=%s ", name);
321			else
322				printf("gid=%u ", cur->st_gid);
323		}
324		if (MATCHFLAG(F_MODE))
325			printf("mode=%#o ", cur->st_mode);
326		if (MATCHFLAG(F_DEV) &&
327		    (cur->type == F_BLOCK || cur->type == F_CHAR))
328			printf("device=%#llx ", (long long)cur->st_rdev);
329		if (MATCHFLAG(F_NLINK))
330			printf("nlink=%d ", cur->st_nlink);
331		if (MATCHFLAG(F_SLINK))
332			printf("link=%s ", vispath(cur->slink));
333		if (MATCHFLAG(F_SIZE))
334			printf("size=%lld ", (long long)cur->st_size);
335		if (MATCHFLAG(F_TIME))
336			printf("time=%lld.%ld ",
337			    (long long)cur->st_mtimespec.tv_sec,
338			    cur->st_mtimespec.tv_nsec);
339		if (MATCHFLAG(F_CKSUM))
340			printf("cksum=%lu ", cur->cksum);
341		if (MATCHFLAG(F_MD5))
342			printf("md5=%s ", cur->md5digest);
343		if (MATCHFLAG(F_RMD160))
344			printf("rmd160=%s ", cur->rmd160digest);
345		if (MATCHFLAG(F_SHA1))
346			printf("sha1=%s ", cur->sha1digest);
347		if (MATCHFLAG(F_SHA256))
348			printf("sha256=%s ", cur->sha256digest);
349		if (MATCHFLAG(F_SHA384))
350			printf("sha384=%s ", cur->sha384digest);
351		if (MATCHFLAG(F_SHA512))
352			printf("sha512=%s ", cur->sha512digest);
353		if (MATCHFLAG(F_FLAGS)) {
354			str = flags_to_string(cur->st_flags, "none");
355			printf("flags=%s ", str);
356			free(str);
357		}
358		if (MATCHFLAG(F_IGN))
359			printf("ignore ");
360		if (MATCHFLAG(F_OPT))
361			printf("optional ");
362		if (MATCHFLAG(F_TAGS)) {
363			/* don't output leading or trailing commas */
364			p = cur->tags;
365			while (*p == ',')
366				p++;
367			q = p + strlen(p);
368			while(q > p && q[-1] == ',')
369				q--;
370			printf("tags=%.*s ", (int)(q - p), p);
371		}
372		puts(pathlast ? vispath(path) : "");
373
374		if (cur->child)
375			dump_nodes(path, cur->child, pathlast);
376	}
377}
378
379/*
380 * vispath --
381 *	strsvis(3) encodes path, which must not be longer than MAXPATHLEN
382 *	characters long, and returns a pointer to a static buffer containing
383 *	the result.
384 */
385char *
386vispath(const char *path)
387{
388	const char extra[] = { ' ', '\t', '\n', '\\', '#', '\0' };
389	static char pathbuf[4*MAXPATHLEN + 1];
390
391	strsvis(pathbuf, path, VIS_CSTYLE, extra);
392	return(pathbuf);
393}
394
395
396static dev_t
397parsedev(char *arg)
398{
399#define MAX_PACK_ARGS	3
400	u_long	numbers[MAX_PACK_ARGS];
401	char	*p, *ep, *dev;
402	int	argc;
403	pack_t	*pack;
404	dev_t	result;
405	const char *error = NULL;
406
407	if ((dev = strchr(arg, ',')) != NULL) {
408		*dev++='\0';
409		if ((pack = pack_find(arg)) == NULL)
410			mtree_err("unknown format `%s'", arg);
411		argc = 0;
412		while ((p = strsep(&dev, ",")) != NULL) {
413			if (*p == '\0')
414				mtree_err("missing number");
415			numbers[argc++] = strtoul(p, &ep, 0);
416			if (*ep != '\0')
417				mtree_err("invalid number `%s'",
418				    p);
419			if (argc > MAX_PACK_ARGS)
420				mtree_err("too many arguments");
421		}
422		if (argc < 2)
423			mtree_err("not enough arguments");
424		result = (*pack)(argc, numbers, &error);
425		if (error != NULL)
426			mtree_err("%s", error);
427	} else {
428		result = (dev_t)strtoul(arg, &ep, 0);
429		if (*ep != '\0')
430			mtree_err("invalid device `%s'", arg);
431	}
432	return (result);
433}
434
435static void
436replacenode(NODE *cur, NODE *new)
437{
438
439#define REPLACE(x)	cur->x = new->x
440#define REPLACESTR(x)	REPLACEPTR(cur->x,new->x)
441
442	if (cur->type != new->type) {
443		if (mtree_Mflag) {
444				/*
445				 * merge entries with different types; we
446				 * don't want children retained in this case.
447				 */
448			REPLACE(type);
449			free_nodes(cur->child);
450			cur->child = NULL;
451		} else {
452			mtree_err(
453			    "existing entry for `%s', type `%s'"
454			    " does not match type `%s'",
455			    cur->name, nodetype(cur->type),
456			    nodetype(new->type));
457		}
458	}
459
460	REPLACE(st_size);
461	REPLACE(st_mtimespec);
462	REPLACESTR(slink);
463	if (cur->slink != NULL) {
464		if ((cur->slink = strdup(new->slink)) == NULL)
465			mtree_err("memory allocation error");
466		if (strunvis(cur->slink, new->slink) == -1)
467			mtree_err("strunvis failed on `%s'", new->slink);
468		free(new->slink);
469	}
470	REPLACE(st_uid);
471	REPLACE(st_gid);
472	REPLACE(st_mode);
473	REPLACE(st_rdev);
474	REPLACE(st_flags);
475	REPLACE(st_nlink);
476	REPLACE(cksum);
477	REPLACESTR(md5digest);
478	REPLACESTR(rmd160digest);
479	REPLACESTR(sha1digest);
480	REPLACESTR(sha256digest);
481	REPLACESTR(sha384digest);
482	REPLACESTR(sha512digest);
483	REPLACESTR(tags);
484	REPLACE(lineno);
485	REPLACE(flags);
486	free(new);
487}
488
489static void
490set(char *t, NODE *ip)
491{
492	int	type, value, len;
493	gid_t	gid;
494	uid_t	uid;
495	char	*kw, *val, *md, *ep;
496	void	*m;
497
498	while ((kw = strsep(&t, "= \t")) != NULL) {
499		if (*kw == '\0')
500			continue;
501		if (strcmp(kw, "all") == 0)
502			mtree_err("invalid keyword `all'");
503		ip->flags |= type = parsekey(kw, &value);
504		if (!value)
505			/* Just set flag bit (F_IGN and F_OPT) */
506			continue;
507		while ((val = strsep(&t, " \t")) != NULL && *val == '\0')
508			continue;
509		if (val == NULL)
510			mtree_err("missing value");
511		switch (type) {
512		case F_CKSUM:
513			ip->cksum = strtoul(val, &ep, 10);
514			if (*ep)
515				mtree_err("invalid checksum `%s'", val);
516			break;
517		case F_DEV:
518			ip->st_rdev = parsedev(val);
519			break;
520		case F_FLAGS:
521			if (strcmp("none", val) == 0)
522				ip->st_flags = 0;
523			else if (string_to_flags(&val, &ip->st_flags, NULL)
524			    != 0)
525				mtree_err("invalid flag `%s'", val);
526			break;
527		case F_GID:
528			ip->st_gid = (gid_t)strtoul(val, &ep, 10);
529			if (*ep)
530				mtree_err("invalid gid `%s'", val);
531			break;
532		case F_GNAME:
533			if (mtree_Wflag)	/* don't parse if whacking */
534				break;
535			if (gid_from_group(val, &gid) == -1)
536				mtree_err("unknown group `%s'", val);
537			ip->st_gid = gid;
538			break;
539		case F_MD5:
540			if (val[0]=='0' && val[1]=='x')
541				md=&val[2];
542			else
543				md=val;
544			if ((ip->md5digest = strdup(md)) == NULL)
545				mtree_err("memory allocation error");
546			break;
547		case F_MODE:
548			if ((m = setmode(val)) == NULL)
549				mtree_err("cannot set file mode `%s' (%s)",
550				    val, strerror(errno));
551			ip->st_mode = getmode(m, 0);
552			free(m);
553			break;
554		case F_NLINK:
555			ip->st_nlink = (nlink_t)strtoul(val, &ep, 10);
556			if (*ep)
557				mtree_err("invalid link count `%s'", val);
558			break;
559		case F_RMD160:
560			if (val[0]=='0' && val[1]=='x')
561				md=&val[2];
562			else
563				md=val;
564			if ((ip->rmd160digest = strdup(md)) == NULL)
565				mtree_err("memory allocation error");
566			break;
567		case F_SHA1:
568			if (val[0]=='0' && val[1]=='x')
569				md=&val[2];
570			else
571				md=val;
572			if ((ip->sha1digest = strdup(md)) == NULL)
573				mtree_err("memory allocation error");
574			break;
575		case F_SIZE:
576			ip->st_size = (off_t)strtoll(val, &ep, 10);
577			if (*ep)
578				mtree_err("invalid size `%s'", val);
579			break;
580		case F_SLINK:
581			if ((ip->slink = strdup(val)) == NULL)
582				mtree_err("memory allocation error");
583			if (strunvis(ip->slink, val) == -1)
584				mtree_err("strunvis failed on `%s'", val);
585			break;
586		case F_TAGS:
587			len = strlen(val) + 3;	/* "," + str + ",\0" */
588			if ((ip->tags = malloc(len)) == NULL)
589				mtree_err("memory allocation error");
590			snprintf(ip->tags, len, ",%s,", val);
591			break;
592		case F_TIME:
593			ip->st_mtimespec.tv_sec =
594			    (time_t)strtoll(val, &ep, 10);
595			if (*ep != '.')
596				mtree_err("invalid time `%s'", val);
597			val = ep + 1;
598			ip->st_mtimespec.tv_nsec = strtol(val, &ep, 10);
599			if (*ep)
600				mtree_err("invalid time `%s'", val);
601			break;
602		case F_TYPE:
603			ip->type = parsetype(val);
604			break;
605		case F_UID:
606			ip->st_uid = (uid_t)strtoul(val, &ep, 10);
607			if (*ep)
608				mtree_err("invalid uid `%s'", val);
609			break;
610		case F_UNAME:
611			if (mtree_Wflag)	/* don't parse if whacking */
612				break;
613			if (uid_from_user(val, &uid) == -1)
614				mtree_err("unknown user `%s'", val);
615			ip->st_uid = uid;
616			break;
617		case F_SHA256:
618			if (val[0]=='0' && val[1]=='x')
619				md=&val[2];
620			else
621				md=val;
622			if ((ip->sha256digest = strdup(md)) == NULL)
623				mtree_err("memory allocation error");
624			break;
625		case F_SHA384:
626			if (val[0]=='0' && val[1]=='x')
627				md=&val[2];
628			else
629				md=val;
630			if ((ip->sha384digest = strdup(md)) == NULL)
631				mtree_err("memory allocation error");
632			break;
633		case F_SHA512:
634			if (val[0]=='0' && val[1]=='x')
635				md=&val[2];
636			else
637				md=val;
638			if ((ip->sha512digest = strdup(md)) == NULL)
639				mtree_err("memory allocation error");
640			break;
641		default:
642			mtree_err(
643			    "set(): unsupported key type 0x%x (INTERNAL ERROR)",
644			    type);
645			/* NOTREACHED */
646		}
647	}
648}
649
650static void
651unset(char *t, NODE *ip)
652{
653	char *p;
654
655	while ((p = strsep(&t, " \t")) != NULL) {
656		if (*p == '\0')
657			continue;
658		ip->flags &= ~parsekey(p, NULL);
659	}
660}
661
662/*
663 * addchild --
664 *	Add the centry node as a child of the pathparent node.	If
665 *	centry is a duplicate, call replacenode().  If centry is not
666 *	a duplicate, insert it into the linked list referenced by
667 *	pathparent->child.  Keep the list sorted.
668 */
669static void
670addchild(NODE *pathparent, NODE *centry)
671{
672	NODE *cur, *insertpos;
673	int cmp;
674
675	cur = pathparent->child;
676	if (cur == NULL) {
677		/* centry is pathparent's first and only child node so far */
678		pathparent->child = centry;
679		return;
680	}
681
682	/*
683	 * pathparent already has at least one other child, so add the
684	 * centry node to the list.
685	 *
686	 * To keep the list sorted, the new centry node will be
687	 * inserted just after the existing insertpos node, if any;
688	 * otherwise it will be inserted at the start of the list.
689	 */
690	insertpos = NULL;
691	for (; cur != NULL; cur = cur->next) {
692		cmp = nodecmp(centry, cur);
693		if (cmp == 0) {
694			/* existing entry; replace */
695			replacenode(cur, centry);
696			break;
697		} else if (cmp > 0) {
698			/* centry appears after cur in sort order */
699			insertpos = cur;
700		}
701		if (cmp < 0 || cur->next == NULL) {
702			/*
703			 * centry appears before cur in sort order,
704			 * or we reached the end of the list; insert
705			 * centry either just after insertpos, or at the
706			 * beginning of the list.
707			 */
708			if (insertpos) {
709				centry->next = insertpos->next;
710				insertpos->next = centry;
711				centry->prev = insertpos;
712				if (centry->next)
713					centry->next->prev = centry;
714			} else {
715				pathparent->child->prev = centry;
716				centry->next = pathparent->child;
717				pathparent->child = centry;
718			}
719			break;
720		}
721	}
722	return;
723}
724
725/*
726 * nodecmp --
727 *	used as a comparison function by addchild() to control the order
728 *	in which entries appear within a list of sibling nodes.	 We make
729 *	directories sort after non-directories, but otherwise sort in
730 *	strcmp() order.
731 *
732 * Keep this in sync with dcmp() in create.c.
733 */
734static int
735nodecmp(const NODE *a, const NODE *b)
736{
737
738	if ((a->type & F_DIR) != 0) {
739		if ((b->type & F_DIR) == 0)
740			return 1;
741	} else if ((b->type & F_DIR) != 0)
742		return -1;
743	return strcmp(a->name, b->name);
744}
745