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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/jffs2/acl.c
Initial import
Diffstat (limited to 'fs/jffs2/acl.c')
-rw-r--r--fs/jffs2/acl.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
new file mode 100644
index 000000000..2f7a3c090
--- /dev/null
+++ b/fs/jffs2/acl.c
@@ -0,0 +1,309 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2006 NEC Corporation
+ *
+ * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <linux/crc32.h>
+#include <linux/jffs2.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/mtd/mtd.h>
+#include "nodelist.h"
+
+static size_t jffs2_acl_size(int count)
+{
+ if (count <= 4) {
+ return sizeof(struct jffs2_acl_header)
+ + count * sizeof(struct jffs2_acl_entry_short);
+ } else {
+ return sizeof(struct jffs2_acl_header)
+ + 4 * sizeof(struct jffs2_acl_entry_short)
+ + (count - 4) * sizeof(struct jffs2_acl_entry);
+ }
+}
+
+static int jffs2_acl_count(size_t size)
+{
+ size_t s;
+
+ size -= sizeof(struct jffs2_acl_header);
+ if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
+ if (size % sizeof(struct jffs2_acl_entry_short))
+ return -1;
+ return size / sizeof(struct jffs2_acl_entry_short);
+ } else {
+ s = size - 4 * sizeof(struct jffs2_acl_entry_short);
+ if (s % sizeof(struct jffs2_acl_entry))
+ return -1;
+ return s / sizeof(struct jffs2_acl_entry) + 4;
+ }
+}
+
+static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
+{
+ void *end = value + size;
+ struct jffs2_acl_header *header = value;
+ struct jffs2_acl_entry *entry;
+ struct posix_acl *acl;
+ uint32_t ver;
+ int i, count;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(struct jffs2_acl_header))
+ return ERR_PTR(-EINVAL);
+ ver = je32_to_cpu(header->a_version);
+ if (ver != JFFS2_ACL_VERSION) {
+ JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
+ return ERR_PTR(-EINVAL);
+ }
+
+ value += sizeof(struct jffs2_acl_header);
+ count = jffs2_acl_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+
+ acl = posix_acl_alloc(count, GFP_KERNEL);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+
+ for (i=0; i < count; i++) {
+ entry = value;
+ if (value + sizeof(struct jffs2_acl_entry_short) > end)
+ goto fail;
+ acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
+ acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
+ switch (acl->a_entries[i].e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ value += sizeof(struct jffs2_acl_entry_short);
+ break;
+
+ case ACL_USER:
+ value += sizeof(struct jffs2_acl_entry);
+ if (value > end)
+ goto fail;
+ acl->a_entries[i].e_uid =
+ make_kuid(&init_user_ns,
+ je32_to_cpu(entry->e_id));
+ break;
+ case ACL_GROUP:
+ value += sizeof(struct jffs2_acl_entry);
+ if (value > end)
+ goto fail;
+ acl->a_entries[i].e_gid =
+ make_kgid(&init_user_ns,
+ je32_to_cpu(entry->e_id));
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ if (value != end)
+ goto fail;
+ return acl;
+ fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+
+static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
+{
+ struct jffs2_acl_header *header;
+ struct jffs2_acl_entry *entry;
+ void *e;
+ size_t i;
+
+ *size = jffs2_acl_size(acl->a_count);
+ header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
+ if (!header)
+ return ERR_PTR(-ENOMEM);
+ header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
+ e = header + 1;
+ for (i=0; i < acl->a_count; i++) {
+ const struct posix_acl_entry *acl_e = &acl->a_entries[i];
+ entry = e;
+ entry->e_tag = cpu_to_je16(acl_e->e_tag);
+ entry->e_perm = cpu_to_je16(acl_e->e_perm);
+ switch(acl_e->e_tag) {
+ case ACL_USER:
+ entry->e_id = cpu_to_je32(
+ from_kuid(&init_user_ns, acl_e->e_uid));
+ e += sizeof(struct jffs2_acl_entry);
+ break;
+ case ACL_GROUP:
+ entry->e_id = cpu_to_je32(
+ from_kgid(&init_user_ns, acl_e->e_gid));
+ e += sizeof(struct jffs2_acl_entry);
+ break;
+
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ e += sizeof(struct jffs2_acl_entry_short);
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ return header;
+ fail:
+ kfree(header);
+ return ERR_PTR(-EINVAL);
+}
+
+struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
+{
+ struct posix_acl *acl;
+ char *value = NULL;
+ int rc, xprefix;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ xprefix = JFFS2_XPREFIX_ACL_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
+ break;
+ default:
+ BUG();
+ }
+ rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
+ if (rc > 0) {
+ value = kmalloc(rc, GFP_KERNEL);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
+ }
+ if (rc > 0) {
+ acl = jffs2_acl_from_medium(value, rc);
+ } else if (rc == -ENODATA || rc == -ENOSYS) {
+ acl = NULL;
+ } else {
+ acl = ERR_PTR(rc);
+ }
+ kfree(value);
+ if (!IS_ERR(acl))
+ set_cached_acl(inode, type, acl);
+ return acl;
+}
+
+static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
+{
+ char *value = NULL;
+ size_t size = 0;
+ int rc;
+
+ if (acl) {
+ value = jffs2_acl_to_medium(acl, &size);
+ if (IS_ERR(value))
+ return PTR_ERR(value);
+ }
+ rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
+ if (!value && rc == -ENODATA)
+ rc = 0;
+ kfree(value);
+
+ return rc;
+}
+
+int jffs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ int rc, xprefix;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ xprefix = JFFS2_XPREFIX_ACL_ACCESS;
+ if (acl) {
+ umode_t mode = inode->i_mode;
+ rc = posix_acl_equiv_mode(acl, &mode);
+ if (rc < 0)
+ return rc;
+ if (inode->i_mode != mode) {
+ struct iattr attr;
+
+ attr.ia_valid = ATTR_MODE | ATTR_CTIME;
+ attr.ia_mode = mode;
+ attr.ia_ctime = CURRENT_TIME_SEC;
+ rc = jffs2_do_setattr(inode, &attr);
+ if (rc < 0)
+ return rc;
+ }
+ if (rc == 0)
+ acl = NULL;
+ }
+ break;
+ case ACL_TYPE_DEFAULT:
+ xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+ rc = __jffs2_set_acl(inode, xprefix, acl);
+ if (!rc)
+ set_cached_acl(inode, type, acl);
+ return rc;
+}
+
+int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
+{
+ struct posix_acl *default_acl, *acl;
+ int rc;
+
+ cache_no_acl(inode);
+
+ rc = posix_acl_create(dir_i, i_mode, &default_acl, &acl);
+ if (rc)
+ return rc;
+
+ if (default_acl) {
+ set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
+ posix_acl_release(default_acl);
+ }
+ if (acl) {
+ set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
+ posix_acl_release(acl);
+ }
+ return 0;
+}
+
+int jffs2_init_acl_post(struct inode *inode)
+{
+ int rc;
+
+ if (inode->i_default_acl) {
+ rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
+ if (rc)
+ return rc;
+ }
+
+ if (inode->i_acl) {
+ rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}