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paths.c revision 1.1
      1 /*	$NetBSD: paths.c,v 1.1 2007/01/15 00:39:02 pooka Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2007  Antti Kantee.  All Rights Reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the company nor the name of the author may be used to
     15  *    endorse or promote products derived from this software without specific
     16  *    prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     21  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 #include <sys/cdefs.h>
     32 #if !defined(lint)
     33 __RCSID("$NetBSD: paths.c,v 1.1 2007/01/15 00:39:02 pooka Exp $");
     34 #endif /* !lint */
     35 
     36 #include <assert.h>
     37 #include <errno.h>
     38 #include <puffs.h>
     39 #include <stdlib.h>
     40 
     41 #include "puffs_priv.h"
     42 
     43 /*
     44  * Generic routines for pathbuilding code
     45  */
     46 
     47 int
     48 puffs_path_pcnbuild(struct puffs_usermount *pu, struct puffs_cn *pcn,
     49 	void *parent)
     50 {
     51 	struct puffs_node *pn_parent = PU_CMAP(pu, parent);
     52 	struct puffs_cn pcn_orig;
     53 	struct puffs_pathobj po;
     54 	int rv;
     55 
     56 	assert(pn_parent->pn_po.po_path != NULL);
     57 
     58 	if (pu->pu_pathtransform) {
     59 		rv = pu->pu_pathtransform(pu, &pn_parent->pn_po, pcn, &po);
     60 		if (rv)
     61 			return rv;
     62 	} else {
     63 		po.po_path = pcn->pcn_name;
     64 		po.po_len = pcn->pcn_namelen;
     65 	}
     66 
     67 	if (pu->pu_namemod) {
     68 		/* XXX: gcc complains if I do assignment */
     69 		memcpy(&pcn_orig, pcn, sizeof(pcn_orig));
     70 		rv = pu->pu_namemod(pu, &pn_parent->pn_po, pcn);
     71 		if (rv)
     72 			return rv;
     73 	}
     74 
     75 	rv = pu->pu_pathbuild(pu, &pn_parent->pn_po, &po, 0,
     76 	    &pcn->pcn_po_full);
     77 
     78 	if (pu->pu_pathtransform)
     79 		pu->pu_pathfree(pu, &po);
     80 
     81 	if (pu->pu_namemod && rv)
     82 		*pcn = pcn_orig;
     83 
     84 	return rv;
     85 }
     86 
     87 /*
     88  * substitute all (child) patch prefixes.  called from nodewalk, which
     89  * in turn is called from rename
     90  */
     91 void *
     92 puffs_path_prefixadj(struct puffs_usermount *pu, struct puffs_node *pn,
     93 	void *arg)
     94 {
     95 	struct puffs_pathinfo *pi = arg;
     96 	struct puffs_pathobj localpo;
     97 	struct puffs_pathobj oldpo;
     98 	int rv;
     99 
    100 	/* can't be a path prefix */
    101 	if (pn->pn_po.po_len < pi->pi_old->po_len)
    102 		return NULL;
    103 
    104 	if (pu->pu_pathcmp(pu, &pn->pn_po, pi->pi_old, pi->pi_old->po_len))
    105 		return NULL;
    106 
    107 	/* otherwise we'd have two nodes with an equal path */
    108 	assert(pn->pn_po.po_len > pi->pi_old->po_len);
    109 
    110 	/* found a matching prefix */
    111 	rv = pu->pu_pathbuild(pu, pi->pi_new, &pn->pn_po,
    112 	    pi->pi_old->po_len, &localpo);
    113 	/*
    114 	 * XXX: technically we shouldn't fail, but this is the only
    115 	 * sensible thing to do here.  If the buildpath routine fails,
    116 	 * we will have paths in an inconsistent state.  Should fix this,
    117 	 * either by having two separate passes or by doing other tricks
    118 	 * to make an invalid path with BUILDPATHS acceptable.
    119 	 */
    120 	if (rv != 0)
    121 		abort();
    122 
    123 	/* out with the old and in with the new */
    124 	oldpo = pn->pn_po;
    125 	pn->pn_po = localpo;
    126 	pu->pu_pathfree(pu, &oldpo);
    127 
    128 	/* continue the walk */
    129 	return NULL;
    130 }
    131 
    132 
    133 /*
    134  * Routines provided to file systems which consider a path a tuple of
    135  * strings and / the component separator.
    136  */
    137 
    138 /*ARGSUSED*/
    139 int
    140 puffs_path_cmppath(struct puffs_usermount *pu, struct puffs_pathobj *c1,
    141 	struct puffs_pathobj *c2, size_t clen)
    142 {
    143 	char *p;
    144 	int rv;
    145 
    146 	rv = strncmp(c1->po_path, c2->po_path, clen);
    147 	if (rv)
    148 		return 1;
    149 
    150 	/* sanity for next step */
    151 	if (!(c1->po_len > c2->po_len))
    152 		return 1;
    153 
    154 	/* check if it's really a complete path prefix */
    155 	p = c1->po_path;
    156 	if ((*(p + clen)) != '/')
    157 		return 1;
    158 
    159 	return 0;
    160 }
    161 
    162 /*ARGSUSED*/
    163 int
    164 puffs_path_buildpath(struct puffs_usermount *pu, struct puffs_pathobj *po_pre,
    165 	struct puffs_pathobj *po_comp, size_t offset,
    166 	struct puffs_pathobj *newpath)
    167 {
    168 	char *path, *pcomp;
    169 	size_t plen, complen;
    170 
    171 	complen = po_comp->po_len - offset;
    172 
    173 	/* seek to correct place & remove all leading '/' from component */
    174 	pcomp = po_comp->po_path;
    175 	pcomp += offset;
    176 	while (*pcomp == '/') {
    177 		pcomp++;
    178 		complen--;
    179 	}
    180 
    181 	/* + '/' + '\0' */
    182 	plen = po_pre->po_len + 1 + complen;
    183 	path = malloc(plen + 1);
    184 	if (path == NULL)
    185 		return errno;
    186 
    187 	strcpy(path, po_pre->po_path);
    188 	strcat(path, "/");
    189 	strncat(path, pcomp, complen);
    190 
    191 	newpath->po_path = path;
    192 	newpath->po_len = plen;
    193 
    194 	return 0;
    195 }
    196 
    197 /*ARGSUSED*/
    198 void
    199 puffs_path_freepath(struct puffs_usermount *pu, struct puffs_pathobj *po)
    200 {
    201 
    202 	free(po->po_path);
    203 }
    204