ia64/linux-2.6.18-xen.hg

view fs/nfs_common/nfsacl.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
1 /*
2 * fs/nfs_common/nfsacl.c
3 *
4 * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
5 */
7 /*
8 * The Solaris nfsacl protocol represents some ACLs slightly differently
9 * than POSIX 1003.1e draft 17 does (and we do):
10 *
11 * - Minimal ACLs always have an ACL_MASK entry, so they have
12 * four instead of three entries.
13 * - The ACL_MASK entry in such minimal ACLs always has the same
14 * permissions as the ACL_GROUP_OBJ entry. (In extended ACLs
15 * the ACL_MASK and ACL_GROUP_OBJ entries may differ.)
16 * - The identifier fields of the ACL_USER_OBJ and ACL_GROUP_OBJ
17 * entries contain the identifiers of the owner and owning group.
18 * (In POSIX ACLs we always set them to ACL_UNDEFINED_ID).
19 * - ACL entries in the kernel are kept sorted in ascending order
20 * of (e_tag, e_id). Solaris ACLs are unsorted.
21 */
23 #include <linux/module.h>
24 #include <linux/fs.h>
25 #include <linux/sunrpc/xdr.h>
26 #include <linux/nfsacl.h>
27 #include <linux/nfs3.h>
28 #include <linux/sort.h>
30 MODULE_LICENSE("GPL");
32 EXPORT_SYMBOL(nfsacl_encode);
33 EXPORT_SYMBOL(nfsacl_decode);
35 struct nfsacl_encode_desc {
36 struct xdr_array2_desc desc;
37 unsigned int count;
38 struct posix_acl *acl;
39 int typeflag;
40 uid_t uid;
41 gid_t gid;
42 };
44 static int
45 xdr_nfsace_encode(struct xdr_array2_desc *desc, void *elem)
46 {
47 struct nfsacl_encode_desc *nfsacl_desc =
48 (struct nfsacl_encode_desc *) desc;
49 u32 *p = (u32 *) elem;
51 struct posix_acl_entry *entry =
52 &nfsacl_desc->acl->a_entries[nfsacl_desc->count++];
54 *p++ = htonl(entry->e_tag | nfsacl_desc->typeflag);
55 switch(entry->e_tag) {
56 case ACL_USER_OBJ:
57 *p++ = htonl(nfsacl_desc->uid);
58 break;
59 case ACL_GROUP_OBJ:
60 *p++ = htonl(nfsacl_desc->gid);
61 break;
62 case ACL_USER:
63 case ACL_GROUP:
64 *p++ = htonl(entry->e_id);
65 break;
66 default: /* Solaris depends on that! */
67 *p++ = 0;
68 break;
69 }
70 *p++ = htonl(entry->e_perm & S_IRWXO);
71 return 0;
72 }
74 unsigned int
75 nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode,
76 struct posix_acl *acl, int encode_entries, int typeflag)
77 {
78 int entries = (acl && acl->a_count) ? max_t(int, acl->a_count, 4) : 0;
79 struct nfsacl_encode_desc nfsacl_desc = {
80 .desc = {
81 .elem_size = 12,
82 .array_len = encode_entries ? entries : 0,
83 .xcode = xdr_nfsace_encode,
84 },
85 .acl = acl,
86 .typeflag = typeflag,
87 .uid = inode->i_uid,
88 .gid = inode->i_gid,
89 };
90 int err;
91 struct posix_acl *acl2 = NULL;
93 if (entries > NFS_ACL_MAX_ENTRIES ||
94 xdr_encode_word(buf, base, entries))
95 return -EINVAL;
96 if (encode_entries && acl && acl->a_count == 3) {
97 /* Fake up an ACL_MASK entry. */
98 acl2 = posix_acl_alloc(4, GFP_KERNEL);
99 if (!acl2)
100 return -ENOMEM;
101 /* Insert entries in canonical order: other orders seem
102 to confuse Solaris VxFS. */
103 acl2->a_entries[0] = acl->a_entries[0]; /* ACL_USER_OBJ */
104 acl2->a_entries[1] = acl->a_entries[1]; /* ACL_GROUP_OBJ */
105 acl2->a_entries[2] = acl->a_entries[1]; /* ACL_MASK */
106 acl2->a_entries[2].e_tag = ACL_MASK;
107 acl2->a_entries[3] = acl->a_entries[2]; /* ACL_OTHER */
108 nfsacl_desc.acl = acl2;
109 }
110 err = xdr_encode_array2(buf, base + 4, &nfsacl_desc.desc);
111 if (acl2)
112 posix_acl_release(acl2);
113 if (!err)
114 err = 8 + nfsacl_desc.desc.elem_size *
115 nfsacl_desc.desc.array_len;
116 return err;
117 }
119 struct nfsacl_decode_desc {
120 struct xdr_array2_desc desc;
121 unsigned int count;
122 struct posix_acl *acl;
123 };
125 static int
126 xdr_nfsace_decode(struct xdr_array2_desc *desc, void *elem)
127 {
128 struct nfsacl_decode_desc *nfsacl_desc =
129 (struct nfsacl_decode_desc *) desc;
130 u32 *p = (u32 *) elem;
131 struct posix_acl_entry *entry;
133 if (!nfsacl_desc->acl) {
134 if (desc->array_len > NFS_ACL_MAX_ENTRIES)
135 return -EINVAL;
136 nfsacl_desc->acl = posix_acl_alloc(desc->array_len, GFP_KERNEL);
137 if (!nfsacl_desc->acl)
138 return -ENOMEM;
139 nfsacl_desc->count = 0;
140 }
142 entry = &nfsacl_desc->acl->a_entries[nfsacl_desc->count++];
143 entry->e_tag = ntohl(*p++) & ~NFS_ACL_DEFAULT;
144 entry->e_id = ntohl(*p++);
145 entry->e_perm = ntohl(*p++);
147 switch(entry->e_tag) {
148 case ACL_USER_OBJ:
149 case ACL_USER:
150 case ACL_GROUP_OBJ:
151 case ACL_GROUP:
152 case ACL_OTHER:
153 if (entry->e_perm & ~S_IRWXO)
154 return -EINVAL;
155 break;
156 case ACL_MASK:
157 /* Solaris sometimes sets additonal bits in the mask */
158 entry->e_perm &= S_IRWXO;
159 break;
160 default:
161 return -EINVAL;
162 }
164 return 0;
165 }
167 static int
168 cmp_acl_entry(const void *x, const void *y)
169 {
170 const struct posix_acl_entry *a = x, *b = y;
172 if (a->e_tag != b->e_tag)
173 return a->e_tag - b->e_tag;
174 else if (a->e_id > b->e_id)
175 return 1;
176 else if (a->e_id < b->e_id)
177 return -1;
178 else
179 return 0;
180 }
182 /*
183 * Convert from a Solaris ACL to a POSIX 1003.1e draft 17 ACL.
184 */
185 static int
186 posix_acl_from_nfsacl(struct posix_acl *acl)
187 {
188 struct posix_acl_entry *pa, *pe,
189 *group_obj = NULL, *mask = NULL;
191 if (!acl)
192 return 0;
194 sort(acl->a_entries, acl->a_count, sizeof(struct posix_acl_entry),
195 cmp_acl_entry, NULL);
197 /* Clear undefined identifier fields and find the ACL_GROUP_OBJ
198 and ACL_MASK entries. */
199 FOREACH_ACL_ENTRY(pa, acl, pe) {
200 switch(pa->e_tag) {
201 case ACL_USER_OBJ:
202 pa->e_id = ACL_UNDEFINED_ID;
203 break;
204 case ACL_GROUP_OBJ:
205 pa->e_id = ACL_UNDEFINED_ID;
206 group_obj = pa;
207 break;
208 case ACL_MASK:
209 mask = pa;
210 /* fall through */
211 case ACL_OTHER:
212 pa->e_id = ACL_UNDEFINED_ID;
213 break;
214 }
215 }
216 if (acl->a_count == 4 && group_obj && mask &&
217 mask->e_perm == group_obj->e_perm) {
218 /* remove bogus ACL_MASK entry */
219 memmove(mask, mask+1, (3 - (mask - acl->a_entries)) *
220 sizeof(struct posix_acl_entry));
221 acl->a_count = 3;
222 }
223 return 0;
224 }
226 unsigned int
227 nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt,
228 struct posix_acl **pacl)
229 {
230 struct nfsacl_decode_desc nfsacl_desc = {
231 .desc = {
232 .elem_size = 12,
233 .xcode = pacl ? xdr_nfsace_decode : NULL,
234 },
235 };
236 u32 entries;
237 int err;
239 if (xdr_decode_word(buf, base, &entries) ||
240 entries > NFS_ACL_MAX_ENTRIES)
241 return -EINVAL;
242 nfsacl_desc.desc.array_maxlen = entries;
243 err = xdr_decode_array2(buf, base + 4, &nfsacl_desc.desc);
244 if (err)
245 return err;
246 if (pacl) {
247 if (entries != nfsacl_desc.desc.array_len ||
248 posix_acl_from_nfsacl(nfsacl_desc.acl) != 0) {
249 posix_acl_release(nfsacl_desc.acl);
250 return -EINVAL;
251 }
252 *pacl = nfsacl_desc.acl;
253 }
254 if (aclcnt)
255 *aclcnt = entries;
256 return 8 + nfsacl_desc.desc.elem_size *
257 nfsacl_desc.desc.array_len;
258 }