summaryrefslogtreecommitdiffstats
path: root/fs/nfs_common/nfsacl.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/nfs_common/nfsacl.c')
-rw-r--r--fs/nfs_common/nfsacl.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c
new file mode 100644
index 00000000000..18c58c32e32
--- /dev/null
+++ b/fs/nfs_common/nfsacl.c
@@ -0,0 +1,257 @@
+/*
+ * fs/nfs_common/nfsacl.c
+ *
+ * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
+ */
+
+/*
+ * The Solaris nfsacl protocol represents some ACLs slightly differently
+ * than POSIX 1003.1e draft 17 does (and we do):
+ *
+ * - Minimal ACLs always have an ACL_MASK entry, so they have
+ * four instead of three entries.
+ * - The ACL_MASK entry in such minimal ACLs always has the same
+ * permissions as the ACL_GROUP_OBJ entry. (In extended ACLs
+ * the ACL_MASK and ACL_GROUP_OBJ entries may differ.)
+ * - The identifier fields of the ACL_USER_OBJ and ACL_GROUP_OBJ
+ * entries contain the identifiers of the owner and owning group.
+ * (In POSIX ACLs we always set them to ACL_UNDEFINED_ID).
+ * - ACL entries in the kernel are kept sorted in ascending order
+ * of (e_tag, e_id). Solaris ACLs are unsorted.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/nfsacl.h>
+#include <linux/nfs3.h>
+#include <linux/sort.h>
+
+MODULE_LICENSE("GPL");
+
+EXPORT_SYMBOL(nfsacl_encode);
+EXPORT_SYMBOL(nfsacl_decode);
+
+struct nfsacl_encode_desc {
+ struct xdr_array2_desc desc;
+ unsigned int count;
+ struct posix_acl *acl;
+ int typeflag;
+ uid_t uid;
+ gid_t gid;
+};
+
+static int
+xdr_nfsace_encode(struct xdr_array2_desc *desc, void *elem)
+{
+ struct nfsacl_encode_desc *nfsacl_desc =
+ (struct nfsacl_encode_desc *) desc;
+ u32 *p = (u32 *) elem;
+
+ if (nfsacl_desc->count < nfsacl_desc->acl->a_count) {
+ struct posix_acl_entry *entry =
+ &nfsacl_desc->acl->a_entries[nfsacl_desc->count++];
+
+ *p++ = htonl(entry->e_tag | nfsacl_desc->typeflag);
+ switch(entry->e_tag) {
+ case ACL_USER_OBJ:
+ *p++ = htonl(nfsacl_desc->uid);
+ break;
+ case ACL_GROUP_OBJ:
+ *p++ = htonl(nfsacl_desc->gid);
+ break;
+ case ACL_USER:
+ case ACL_GROUP:
+ *p++ = htonl(entry->e_id);
+ break;
+ default: /* Solaris depends on that! */
+ *p++ = 0;
+ break;
+ }
+ *p++ = htonl(entry->e_perm & S_IRWXO);
+ } else {
+ const struct posix_acl_entry *pa, *pe;
+ int group_obj_perm = ACL_READ|ACL_WRITE|ACL_EXECUTE;
+
+ FOREACH_ACL_ENTRY(pa, nfsacl_desc->acl, pe) {
+ if (pa->e_tag == ACL_GROUP_OBJ) {
+ group_obj_perm = pa->e_perm & S_IRWXO;
+ break;
+ }
+ }
+ /* fake up ACL_MASK entry */
+ *p++ = htonl(ACL_MASK | nfsacl_desc->typeflag);
+ *p++ = htonl(0);
+ *p++ = htonl(group_obj_perm);
+ }
+
+ return 0;
+}
+
+unsigned int
+nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode,
+ struct posix_acl *acl, int encode_entries, int typeflag)
+{
+ int entries = (acl && acl->a_count) ? max_t(int, acl->a_count, 4) : 0;
+ struct nfsacl_encode_desc nfsacl_desc = {
+ .desc = {
+ .elem_size = 12,
+ .array_len = encode_entries ? entries : 0,
+ .xcode = xdr_nfsace_encode,
+ },
+ .acl = acl,
+ .typeflag = typeflag,
+ .uid = inode->i_uid,
+ .gid = inode->i_gid,
+ };
+ int err;
+
+ if (entries > NFS_ACL_MAX_ENTRIES ||
+ xdr_encode_word(buf, base, entries))
+ return -EINVAL;
+ err = xdr_encode_array2(buf, base + 4, &nfsacl_desc.desc);
+ if (!err)
+ err = 8 + nfsacl_desc.desc.elem_size *
+ nfsacl_desc.desc.array_len;
+ return err;
+}
+
+struct nfsacl_decode_desc {
+ struct xdr_array2_desc desc;
+ unsigned int count;
+ struct posix_acl *acl;
+};
+
+static int
+xdr_nfsace_decode(struct xdr_array2_desc *desc, void *elem)
+{
+ struct nfsacl_decode_desc *nfsacl_desc =
+ (struct nfsacl_decode_desc *) desc;
+ u32 *p = (u32 *) elem;
+ struct posix_acl_entry *entry;
+
+ if (!nfsacl_desc->acl) {
+ if (desc->array_len > NFS_ACL_MAX_ENTRIES)
+ return -EINVAL;
+ nfsacl_desc->acl = posix_acl_alloc(desc->array_len, GFP_KERNEL);
+ if (!nfsacl_desc->acl)
+ return -ENOMEM;
+ nfsacl_desc->count = 0;
+ }
+
+ entry = &nfsacl_desc->acl->a_entries[nfsacl_desc->count++];
+ entry->e_tag = ntohl(*p++) & ~NFS_ACL_DEFAULT;
+ entry->e_id = ntohl(*p++);
+ entry->e_perm = ntohl(*p++);
+
+ switch(entry->e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_USER:
+ case ACL_GROUP_OBJ:
+ case ACL_GROUP:
+ case ACL_OTHER:
+ if (entry->e_perm & ~S_IRWXO)
+ return -EINVAL;
+ break;
+ case ACL_MASK:
+ /* Solaris sometimes sets additonal bits in the mask */
+ entry->e_perm &= S_IRWXO;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int
+cmp_acl_entry(const void *x, const void *y)
+{
+ const struct posix_acl_entry *a = x, *b = y;
+
+ if (a->e_tag != b->e_tag)
+ return a->e_tag - b->e_tag;
+ else if (a->e_id > b->e_id)
+ return 1;
+ else if (a->e_id < b->e_id)
+ return -1;
+ else
+ return 0;
+}
+
+/*
+ * Convert from a Solaris ACL to a POSIX 1003.1e draft 17 ACL.
+ */
+static int
+posix_acl_from_nfsacl(struct posix_acl *acl)
+{
+ struct posix_acl_entry *pa, *pe,
+ *group_obj = NULL, *mask = NULL;
+
+ if (!acl)
+ return 0;
+
+ sort(acl->a_entries, acl->a_count, sizeof(struct posix_acl_entry),
+ cmp_acl_entry, NULL);
+
+ /* Clear undefined identifier fields and find the ACL_GROUP_OBJ
+ and ACL_MASK entries. */
+ FOREACH_ACL_ENTRY(pa, acl, pe) {
+ switch(pa->e_tag) {
+ case ACL_USER_OBJ:
+ pa->e_id = ACL_UNDEFINED_ID;
+ break;
+ case ACL_GROUP_OBJ:
+ pa->e_id = ACL_UNDEFINED_ID;
+ group_obj = pa;
+ break;
+ case ACL_MASK:
+ mask = pa;
+ /* fall through */
+ case ACL_OTHER:
+ pa->e_id = ACL_UNDEFINED_ID;
+ break;
+ }
+ }
+ if (acl->a_count == 4 && group_obj && mask &&
+ mask->e_perm == group_obj->e_perm) {
+ /* remove bogus ACL_MASK entry */
+ memmove(mask, mask+1, (3 - (mask - acl->a_entries)) *
+ sizeof(struct posix_acl_entry));
+ acl->a_count = 3;
+ }
+ return 0;
+}
+
+unsigned int
+nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt,
+ struct posix_acl **pacl)
+{
+ struct nfsacl_decode_desc nfsacl_desc = {
+ .desc = {
+ .elem_size = 12,
+ .xcode = pacl ? xdr_nfsace_decode : NULL,
+ },
+ };
+ u32 entries;
+ int err;
+
+ if (xdr_decode_word(buf, base, &entries) ||
+ entries > NFS_ACL_MAX_ENTRIES)
+ return -EINVAL;
+ err = xdr_decode_array2(buf, base + 4, &nfsacl_desc.desc);
+ if (err)
+ return err;
+ if (pacl) {
+ if (entries != nfsacl_desc.desc.array_len ||
+ posix_acl_from_nfsacl(nfsacl_desc.acl) != 0) {
+ posix_acl_release(nfsacl_desc.acl);
+ return -EINVAL;
+ }
+ *pacl = nfsacl_desc.acl;
+ }
+ if (aclcnt)
+ *aclcnt = entries;
+ return 8 + nfsacl_desc.desc.elem_size *
+ nfsacl_desc.desc.array_len;
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-19 17:28:59 +0000