xref: /netbsd-src/lib/libperfuse/subr.c (revision b757af438b42b93f8c6571f026d8b8ef3eaf5fc9)
1 /*  $NetBSD: subr.c,v 1.17 2012/03/21 10:10:36 matt Exp $ */
2 
3 /*-
4  *  Copyright (c) 2010-2011 Emmanuel Dreyfus. 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  *
15  *  THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
16  *  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17  *  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18  *  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
19  *  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  *  POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <err.h>
31 #include <errno.h>
32 #include <sysexits.h>
33 #include <syslog.h>
34 #include <puffs.h>
35 #include <paths.h>
36 #include <sys/extattr.h>
37 
38 #include "perfuse_priv.h"
39 
40 struct perfuse_ns_map {
41 	const char *pnm_ns;
42 	const size_t pnm_nslen;
43 	const int pnm_native_ns;
44 };
45 
46 #define PERFUSE_NS_MAP(ns, native_ns)	\
47 	{ ns ".", sizeof(ns), native_ns }
48 
49 static size_t node_path(puffs_cookie_t, char *, size_t);
50 
51 struct puffs_node *
52 perfuse_new_pn(struct puffs_usermount *pu, const char *name,
53 	struct puffs_node *parent)
54 {
55 	struct puffs_node *pn;
56 	struct perfuse_node_data *pnd;
57 
58 	if ((pnd = malloc(sizeof(*pnd))) == NULL)
59 		DERR(EX_OSERR, "%s: malloc failed", __func__);
60 
61 	if ((pn = puffs_pn_new(pu, pnd)) == NULL)
62 		DERR(EX_SOFTWARE, "%s: puffs_pn_new failed", __func__);
63 
64 	(void)memset(pnd, 0, sizeof(*pnd));
65 	pnd->pnd_rfh = FUSE_UNKNOWN_FH;
66 	pnd->pnd_wfh = FUSE_UNKNOWN_FH;
67 	pnd->pnd_nodeid = PERFUSE_UNKNOWN_NODEID;
68 	pnd->pnd_fuse_nlookup = 1;
69 	pnd->pnd_puffs_nlookup = 1;
70 	pnd->pnd_parent = parent;
71 	pnd->pnd_pn = (puffs_cookie_t)pn;
72 	(void)strlcpy(pnd->pnd_name, name, MAXPATHLEN);
73 	TAILQ_INIT(&pnd->pnd_pcq);
74 	TAILQ_INIT(&pnd->pnd_children);
75 
76 	if (parent != NULL) {
77 		struct perfuse_node_data *parent_pnd;
78 
79 		parent_pnd = PERFUSE_NODE_DATA(parent);
80 		TAILQ_INSERT_TAIL(&parent_pnd->pnd_children, pnd, pnd_next);
81 
82 		parent_pnd->pnd_childcount++;
83 	}
84 
85 	return pn;
86 }
87 
88 void
89 perfuse_destroy_pn(struct puffs_node *pn)
90 {
91 	struct perfuse_node_data *pnd;
92 
93 	pnd = PERFUSE_NODE_DATA(pn);
94 
95 	if (pnd->pnd_parent != NULL) {
96 		struct perfuse_node_data *parent_pnd;
97 
98 		parent_pnd = PERFUSE_NODE_DATA(pnd->pnd_parent);
99 		TAILQ_REMOVE(&parent_pnd->pnd_children, pnd, pnd_next);
100 	}
101 
102 	if ((pnd = puffs_pn_getpriv(pn)) != NULL) {
103 		if (pnd->pnd_parent != NULL)
104 			PERFUSE_NODE_DATA(pnd->pnd_parent)->pnd_childcount--;
105 
106 		if (pnd->pnd_dirent != NULL)
107 			free(pnd->pnd_dirent);
108 
109 		if (pnd->pnd_all_fd != NULL)
110 			free(pnd->pnd_all_fd);
111 #ifdef PERFUSE_DEBUG
112 		if (pnd->pnd_flags & PND_OPEN)
113 			DERRX(EX_SOFTWARE, "%s: file open", __func__);
114 
115 		if (!TAILQ_EMPTY(&pnd->pnd_pcq))
116 			DERRX(EX_SOFTWARE, "%s: non empty pnd_pcq", __func__);
117 
118 		if (pnd == NULL)
119 			DERRX(EX_SOFTWARE, "%s: pnd == NULL ???", __func__);
120 #endif /* PERFUSE_DEBUG */
121 
122 		free(pnd);
123 	}
124 
125 	puffs_pn_put(pn);
126 
127 	return;
128 }
129 
130 
131 void
132 perfuse_new_fh(puffs_cookie_t opc, uint64_t fh, int mode)
133 {
134 	struct perfuse_node_data *pnd;
135 
136 	pnd = PERFUSE_NODE_DATA(opc);
137 
138 	if (mode & FWRITE) {
139 		if (pnd->pnd_flags & PND_WFH)
140 			DERRX(EX_SOFTWARE, "%s: opc = %p, write fh already set",
141 			      __func__, (void *)opc);
142 		pnd->pnd_wfh = fh;
143 		pnd->pnd_flags |= PND_WFH;
144 	}
145 
146 	if (mode & FREAD) {
147 		if (pnd->pnd_flags & PND_RFH)
148 			DERRX(EX_SOFTWARE, "%s: opc = %p, read fh already set",
149 			      __func__, (void *)opc);
150 		pnd->pnd_rfh = fh;
151 		pnd->pnd_flags |= PND_RFH;
152 	}
153 
154 	return;
155 }
156 
157 void
158 perfuse_destroy_fh(puffs_cookie_t opc, uint64_t fh)
159 {
160 	struct perfuse_node_data *pnd;
161 
162 	pnd = PERFUSE_NODE_DATA(opc);
163 
164 	if (fh == pnd->pnd_rfh) {
165 		if (!(pnd->pnd_flags & PND_RFH) && (fh != FUSE_UNKNOWN_FH))
166 			DERRX(EX_SOFTWARE,
167 			      "%s: opc = %p, unset rfh = %"PRIx64"",
168 			      __func__, (void *)opc, fh);
169 		pnd->pnd_rfh = FUSE_UNKNOWN_FH;
170 		pnd->pnd_flags &= ~PND_RFH;
171 	}
172 
173 	if (fh == pnd->pnd_wfh) {
174 		if (!(pnd->pnd_flags & PND_WFH) && (fh != FUSE_UNKNOWN_FH))
175 			DERRX(EX_SOFTWARE,
176 			      "%s: opc = %p, unset wfh = %"PRIx64"",
177 			      __func__, (void *)opc, fh);
178 		pnd->pnd_wfh = FUSE_UNKNOWN_FH;
179 		pnd->pnd_flags &= ~PND_WFH;
180 	}
181 
182 	return;
183 }
184 
185 uint64_t
186 perfuse_get_fh(puffs_cookie_t opc, int mode)
187 {
188 	struct perfuse_node_data *pnd;
189 
190 	pnd = PERFUSE_NODE_DATA(opc);
191 
192 	if (mode & FWRITE) {
193 		if (pnd->pnd_flags & PND_WFH)
194 			return pnd->pnd_wfh;
195 	}
196 
197 	if (mode & FREAD) {
198 		if (pnd->pnd_flags & PND_RFH)
199 			return pnd->pnd_rfh;
200 
201 		if (pnd->pnd_flags & PND_WFH)
202 			return pnd->pnd_wfh;
203 
204 	}
205 
206 	return FUSE_UNKNOWN_FH;
207 }
208 
209 static size_t
210 node_path(puffs_cookie_t opc, char *buf, size_t buflen)
211 {
212 	struct perfuse_node_data *pnd;
213 	size_t written;
214 
215 	pnd = PERFUSE_NODE_DATA(opc);
216 	if (pnd->pnd_parent == opc)
217 		return 0;
218 
219 	written = node_path(pnd->pnd_parent, buf, buflen);
220 	buf += written;
221 	buflen -= written;
222 
223 	return written + snprintf(buf, buflen, "/%s", pnd->pnd_name);
224 }
225 
226 char *
227 perfuse_node_path(puffs_cookie_t opc)
228 {
229 	static char buf[MAXPATHLEN + 1];
230 
231 	if (node_path(opc, buf, sizeof(buf)) == 0)
232 		sprintf(buf, "/");
233 
234 	return buf;
235 }
236 
237 const char *
238 perfuse_native_ns(const int attrnamespace, const char *attrname,
239 	char *fuse_attrname)
240 {
241 	const struct perfuse_ns_map *pnm;
242 	const struct perfuse_ns_map perfuse_ns_map[] = {
243 		PERFUSE_NS_MAP("trusted", EXTATTR_NAMESPACE_SYSTEM),
244 		PERFUSE_NS_MAP("security", EXTATTR_NAMESPACE_SYSTEM),
245 		PERFUSE_NS_MAP("system", EXTATTR_NAMESPACE_SYSTEM),
246 		PERFUSE_NS_MAP("user", EXTATTR_NAMESPACE_USER),
247 		{ NULL, 0, EXTATTR_NAMESPACE_USER },
248 	};
249 
250 	/*
251 	 * If attribute has a reserved Linux namespace (e.g.: trusted.foo)
252 	 * and that namespace matches the requested native namespace
253 	 * we have nothing to do.
254 	 * Otherwise we have either:
255 	 * (system|trusted|security).* with user namespace: prepend user.
256 	 * anything else with system napespace: prepend system.
257 	 */
258 	for (pnm = perfuse_ns_map; pnm->pnm_ns; pnm++) {
259 		if (strncmp(attrname, pnm->pnm_ns, pnm->pnm_nslen) != 0)
260 			continue;
261 
262 		if (attrnamespace == pnm->pnm_native_ns)
263 			return attrname;
264 
265 	 	/* (system|trusted|security).* with user namespace */
266 		if (attrnamespace == EXTATTR_NAMESPACE_USER) {
267 			(void)snprintf(fuse_attrname, LINUX_XATTR_NAME_MAX,
268 				       "user.%s", attrname);
269 			return (const char *)fuse_attrname;
270 		}
271 	}
272 
273 	/* anything else with system napespace */
274 	if (attrnamespace == EXTATTR_NAMESPACE_SYSTEM) {
275 		(void)snprintf(fuse_attrname, LINUX_XATTR_NAME_MAX,
276 			       "system.%s", attrname);
277 		return (const char *)fuse_attrname;
278 	}
279 
280 	return (const char *)attrname;
281 }
282