ANDROID: sdcardfs: Switch strcasecmp for internal call
This moves our uses of strcasecmp over to an internal call so we can
easily change implementations later if we so desire. Additionally,
we leverage qstr's where appropriate to save time on comparisons.
Change-Id: I32fdc4fd0cd3b7b735dcfd82f60a2516fd8272a5
Signed-off-by: Daniel Rosenberg <drosen@google.com>
diff --git a/fs/sdcardfs/derived_perm.c b/fs/sdcardfs/derived_perm.c
index d2bff5e..0bb4423 100644
--- a/fs/sdcardfs/derived_perm.c
+++ b/fs/sdcardfs/derived_perm.c
@@ -51,11 +51,16 @@
}
/* While renaming, there is a point where we want the path from dentry, but the name from newdentry */
-void get_derived_permission_new(struct dentry *parent, struct dentry *dentry, const char *name)
+void get_derived_permission_new(struct dentry *parent, struct dentry *dentry, const struct qstr *name)
{
struct sdcardfs_inode_info *info = SDCARDFS_I(d_inode(dentry));
struct sdcardfs_inode_info *parent_info= SDCARDFS_I(d_inode(parent));
appid_t appid;
+ struct qstr q_Android = QSTR_LITERAL("Android");
+ struct qstr q_data = QSTR_LITERAL("data");
+ struct qstr q_obb = QSTR_LITERAL("obb");
+ struct qstr q_media = QSTR_LITERAL("media");
+ struct qstr q_cache = QSTR_LITERAL("cache");
/* By default, each inode inherits from its parent.
* the properties are maintained on its private fields
@@ -79,12 +84,12 @@
case PERM_PRE_ROOT:
/* Legacy internal layout places users at top level */
info->perm = PERM_ROOT;
- info->userid = simple_strtoul(name, NULL, 10);
+ info->userid = simple_strtoul(name->name, NULL, 10);
set_top(info, &info->vfs_inode);
break;
case PERM_ROOT:
/* Assume masked off by default. */
- if (!strcasecmp(name, "Android")) {
+ if (qstr_case_eq(name, &q_Android)) {
/* App-specific directories inside; let anyone traverse */
info->perm = PERM_ANDROID;
info->under_android = true;
@@ -92,17 +97,17 @@
}
break;
case PERM_ANDROID:
- if (!strcasecmp(name, "data")) {
+ if (qstr_case_eq(name, &q_data)) {
/* App-specific directories inside; let anyone traverse */
info->perm = PERM_ANDROID_DATA;
set_top(info, &info->vfs_inode);
- } else if (!strcasecmp(name, "obb")) {
+ } else if (qstr_case_eq(name, &q_obb)) {
/* App-specific directories inside; let anyone traverse */
info->perm = PERM_ANDROID_OBB;
info->under_obb = true;
set_top(info, &info->vfs_inode);
/* Single OBB directory is always shared */
- } else if (!strcasecmp(name, "media")) {
+ } else if (qstr_case_eq(name, &q_media)) {
/* App-specific directories inside; let anyone traverse */
info->perm = PERM_ANDROID_MEDIA;
set_top(info, &info->vfs_inode);
@@ -112,14 +117,14 @@
case PERM_ANDROID_DATA:
case PERM_ANDROID_MEDIA:
info->perm = PERM_ANDROID_PACKAGE;
- appid = get_appid(name);
- if (appid != 0 && !is_excluded(name, parent_info->userid)) {
+ appid = get_appid(name->name);
+ if (appid != 0 && !is_excluded(name->name, parent_info->userid)) {
info->d_uid = multiuser_get_uid(parent_info->userid, appid);
}
set_top(info, &info->vfs_inode);
break;
case PERM_ANDROID_PACKAGE:
- if (!strcasecmp(name, "cache")) {
+ if (qstr_case_eq(name, &q_cache)) {
info->perm = PERM_ANDROID_PACKAGE_CACHE;
info->under_cache = true;
}
@@ -129,7 +134,7 @@
void get_derived_permission(struct dentry *parent, struct dentry *dentry)
{
- get_derived_permission_new(parent, dentry, dentry->d_name.name);
+ get_derived_permission_new(parent, dentry, &dentry->d_name);
}
static appid_t get_type(const char *name) {
@@ -360,9 +365,10 @@
struct dentry *parent = dget_parent(dentry);
struct sdcardfs_inode_info *parent_info= SDCARDFS_I(d_inode(parent));
struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ struct qstr obb = QSTR_LITERAL("obb");
if(parent_info->perm == PERM_ANDROID &&
- !strcasecmp(dentry->d_name.name, "obb")) {
+ qstr_case_eq(&dentry->d_name, &obb)) {
/* /Android/obb is the base obbpath of DERIVED_UNIFIED */
if(!(sbi->options.multiuser == false
@@ -399,7 +405,7 @@
} else {
obbpath_s = d_path(&di->lower_path, path_buf, PATH_MAX);
if (d_unhashed(di->lower_path.dentry) ||
- strcasecmp(sbi->obbpath_s, obbpath_s)) {
+ !str_case_eq(sbi->obbpath_s, obbpath_s)) {
ret = 1;
}
kfree(path_buf);
@@ -419,15 +425,16 @@
struct dentry *parent = dget_parent(dentry);
struct sdcardfs_inode_info *parent_info= SDCARDFS_I(d_inode(parent));
struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ struct qstr q_obb = QSTR_LITERAL("obb");
spin_lock(&SDCARDFS_D(dentry)->lock);
if (sbi->options.multiuser) {
if(parent_info->perm == PERM_PRE_ROOT &&
- !strcasecmp(dentry->d_name.name, "obb")) {
+ qstr_case_eq(&dentry->d_name, &q_obb)) {
ret = 1;
}
} else if (parent_info->perm == PERM_ANDROID &&
- !strcasecmp(dentry->d_name.name, "obb")) {
+ qstr_case_eq(&dentry->d_name, &q_obb)) {
ret = 1;
}
spin_unlock(&SDCARDFS_D(dentry)->lock);
diff --git a/fs/sdcardfs/file.c b/fs/sdcardfs/file.c
index 006c6ff..23f8cd7 100644
--- a/fs/sdcardfs/file.c
+++ b/fs/sdcardfs/file.c
@@ -216,7 +216,7 @@
goto out_err;
}
- if(!check_caller_access_to_name(d_inode(parent), dentry->d_name.name)) {
+ if(!check_caller_access_to_name(d_inode(parent), &dentry->d_name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
diff --git a/fs/sdcardfs/inode.c b/fs/sdcardfs/inode.c
index cb05886..68e6150 100644
--- a/fs/sdcardfs/inode.c
+++ b/fs/sdcardfs/inode.c
@@ -66,7 +66,7 @@
struct fs_struct *saved_fs;
struct fs_struct *copied_fs;
- if(!check_caller_access_to_name(dir, dentry->d_name.name)) {
+ if(!check_caller_access_to_name(dir, &dentry->d_name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
@@ -168,7 +168,7 @@
struct path lower_path;
const struct cred *saved_cred = NULL;
- if(!check_caller_access_to_name(dir, dentry->d_name.name)) {
+ if(!check_caller_access_to_name(dir, &dentry->d_name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
@@ -275,8 +275,10 @@
int touch_err = 0;
struct fs_struct *saved_fs;
struct fs_struct *copied_fs;
+ struct qstr q_obb = QSTR_LITERAL("obb");
+ struct qstr q_data = QSTR_LITERAL("data");
- if(!check_caller_access_to_name(dir, dentry->d_name.name)) {
+ if(!check_caller_access_to_name(dir, &dentry->d_name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
@@ -351,13 +353,13 @@
set_nlink(dir, sdcardfs_lower_inode(dir)->i_nlink);
fixup_lower_ownership(dentry, dentry->d_name.name);
unlock_dir(lower_parent_dentry);
- if ((!sbi->options.multiuser) && (!strcasecmp(dentry->d_name.name, "obb"))
+ if ((!sbi->options.multiuser) && (qstr_case_eq(&dentry->d_name, &q_obb))
&& (pi->perm == PERM_ANDROID) && (pi->userid == 0))
make_nomedia_in_obb = 1;
/* When creating /Android/data and /Android/obb, mark them as .nomedia */
if (make_nomedia_in_obb ||
- ((pi->perm == PERM_ANDROID) && (!strcasecmp(dentry->d_name.name, "data")))) {
+ ((pi->perm == PERM_ANDROID) && (qstr_case_eq(&dentry->d_name, &q_data)))) {
REVERT_CRED(saved_cred);
OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred, SDCARDFS_I(d_inode(dentry)));
set_fs_pwd(current->fs, &lower_path);
@@ -388,7 +390,7 @@
struct path lower_path;
const struct cred *saved_cred = NULL;
- if(!check_caller_access_to_name(dir, dentry->d_name.name)) {
+ if(!check_caller_access_to_name(dir, &dentry->d_name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
@@ -476,8 +478,8 @@
struct path lower_old_path, lower_new_path;
const struct cred *saved_cred = NULL;
- if(!check_caller_access_to_name(old_dir, old_dentry->d_name.name) ||
- !check_caller_access_to_name(new_dir, new_dentry->d_name.name)) {
+ if(!check_caller_access_to_name(old_dir, &old_dentry->d_name) ||
+ !check_caller_access_to_name(new_dir, &new_dentry->d_name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" new_dentry: %s, task:%s\n",
__func__, new_dentry->d_name.name, current->comm);
@@ -523,7 +525,7 @@
sdcardfs_copy_and_fix_attrs(old_dir, d_inode(lower_old_dir_dentry));
fsstack_copy_inode_size(old_dir, d_inode(lower_old_dir_dentry));
}
- get_derived_permission_new(new_dentry->d_parent, old_dentry, new_dentry->d_name.name);
+ get_derived_permission_new(new_dentry->d_parent, old_dentry, &new_dentry->d_name);
fixup_tmp_permissions(d_inode(old_dentry));
fixup_lower_ownership(old_dentry, new_dentry->d_name.name);
drop_recursive(old_dentry); /* Can't fixup ownership recursively :( */
@@ -743,7 +745,7 @@
if (!err) {
/* check the Android group ID */
parent = dget_parent(dentry);
- if(!check_caller_access_to_name(d_inode(parent), dentry->d_name.name)) {
+ if(!check_caller_access_to_name(d_inode(parent), &dentry->d_name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
@@ -861,7 +863,7 @@
int err;
parent = dget_parent(dentry);
- if(!check_caller_access_to_name(d_inode(parent), dentry->d_name.name)) {
+ if(!check_caller_access_to_name(d_inode(parent), &dentry->d_name)) {
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
__func__, dentry->d_name.name, current->comm);
diff --git a/fs/sdcardfs/lookup.c b/fs/sdcardfs/lookup.c
index 3c9454e..9135866 100644
--- a/fs/sdcardfs/lookup.c
+++ b/fs/sdcardfs/lookup.c
@@ -219,9 +219,8 @@
struct vfsmount *lower_dir_mnt;
struct dentry *lower_dir_dentry = NULL;
struct dentry *lower_dentry;
- const char *name;
+ const struct qstr *name;
struct path lower_path;
- struct qstr this;
struct sdcardfs_sb_info *sbi;
sbi = SDCARDFS_SB(dentry->d_sb);
@@ -231,14 +230,14 @@
if (IS_ROOT(dentry))
goto out;
- name = dentry->d_name.name;
+ name = &dentry->d_name;
/* now start the actual lookup procedure */
lower_dir_dentry = lower_parent_path->dentry;
lower_dir_mnt = lower_parent_path->mnt;
/* Use vfs_path_lookup to check if the dentry exists or not */
- err = vfs_path_lookup(lower_dir_dentry, lower_dir_mnt, name, 0,
+ err = vfs_path_lookup(lower_dir_dentry, lower_dir_mnt, name->name, 0,
&lower_path);
/* check for other cases */
if (err == -ENOENT) {
@@ -248,7 +247,7 @@
spin_lock(&lower_dir_dentry->d_lock);
list_for_each_entry(child, &lower_dir_dentry->d_subdirs, d_child) {
if (child && d_inode(child)) {
- if (strcasecmp(child->d_name.name, name)==0) {
+ if (qstr_case_eq(&child->d_name, name)) {
match = dget(child);
break;
}
@@ -307,14 +306,11 @@
goto out;
/* instatiate a new negative dentry */
- this.name = name;
- this.len = strlen(name);
- this.hash = full_name_hash(this.name, this.len);
- lower_dentry = d_lookup(lower_dir_dentry, &this);
+ lower_dentry = d_lookup(lower_dir_dentry, name);
if (lower_dentry)
goto setup_lower;
- lower_dentry = d_alloc(lower_dir_dentry, &this);
+ lower_dentry = d_alloc(lower_dir_dentry, name);
if (!lower_dentry) {
err = -ENOMEM;
goto out;
@@ -359,7 +355,7 @@
parent = dget_parent(dentry);
- if(!check_caller_access_to_name(d_inode(parent), dentry->d_name.name)) {
+ if(!check_caller_access_to_name(d_inode(parent), &dentry->d_name)) {
ret = ERR_PTR(-EACCES);
printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
" dentry: %s, task:%s\n",
diff --git a/fs/sdcardfs/packagelist.c b/fs/sdcardfs/packagelist.c
index b02feef..d96fcde 100644
--- a/fs/sdcardfs/packagelist.c
+++ b/fs/sdcardfs/packagelist.c
@@ -65,7 +65,7 @@
rcu_read_lock();
hash_for_each_possible_rcu(package_to_appid, hash_cur, hlist, hash) {
- if (!strcasecmp(key->name, hash_cur->key.name)) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
ret_id = atomic_read(&hash_cur->value);
rcu_read_unlock();
return ret_id;
@@ -90,7 +90,7 @@
rcu_read_lock();
hash_for_each_possible_rcu(ext_to_groupid, hash_cur, hlist, hash) {
- if (!strcasecmp(key->name, hash_cur->key.name)) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
ret_id = atomic_read(&hash_cur->value);
rcu_read_unlock();
return ret_id;
@@ -115,7 +115,7 @@
rcu_read_lock();
hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
if (atomic_read(&hash_cur->value) == user &&
- !strcasecmp(app_name->name, hash_cur->key.name)) {
+ qstr_case_eq(app_name, &hash_cur->key)) {
rcu_read_unlock();
return 1;
}
@@ -124,24 +124,26 @@
return 0;
}
-appid_t is_excluded(const char *app_name, userid_t user)
+appid_t is_excluded(const char *key, userid_t user)
{
struct qstr q;
- qstr_init(&q, app_name);
+ qstr_init(&q, key);
return __is_excluded(&q, user);
}
-
/* Kernel has already enforced everything we returned through
* derive_permissions_locked(), so this is used to lock down access
* even further, such as enforcing that apps hold sdcard_rw. */
-int check_caller_access_to_name(struct inode *parent_node, const char* name) {
+int check_caller_access_to_name(struct inode *parent_node, const struct qstr *name) {
+ struct qstr q_autorun = QSTR_LITERAL("autorun.inf");
+ struct qstr q__android_secure = QSTR_LITERAL(".android_secure");
+ struct qstr q_android_secure = QSTR_LITERAL("android_secure");
/* Always block security-sensitive files at root */
if (parent_node && SDCARDFS_I(parent_node)->perm == PERM_ROOT) {
- if (!strcasecmp(name, "autorun.inf")
- || !strcasecmp(name, ".android_secure")
- || !strcasecmp(name, "android_secure")) {
+ if (qstr_case_eq(name, &q_autorun)
+ || qstr_case_eq(name, &q__android_secure)
+ || qstr_case_eq(name, &q_android_secure)) {
return 0;
}
}
@@ -193,7 +195,7 @@
unsigned int hash = key->hash;
hash_for_each_possible_rcu(package_to_appid, hash_cur, hlist, hash) {
- if (!strcasecmp(key->name, hash_cur->key.name)) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
atomic_set(&hash_cur->value, value);
return 0;
}
@@ -213,7 +215,7 @@
/* An extension can only belong to one gid */
hash_for_each_possible_rcu(ext_to_groupid, hash_cur, hlist, hash) {
- if (!strcasecmp(key->name, hash_cur->key.name))
+ if (qstr_case_eq(key, &hash_cur->key))
return -EINVAL;
}
new_entry = alloc_hashtable_entry(key, value);
@@ -232,7 +234,7 @@
/* Only insert if not already present */
hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
if (atomic_read(&hash_cur->value) == value &&
- !strcasecmp(key->name, hash_cur->key.name))
+ qstr_case_eq(key, &hash_cur->key))
return 0;
}
new_entry = alloc_hashtable_entry(key, value);
@@ -336,13 +338,13 @@
HLIST_HEAD(free_list);
hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
- if (!strcasecmp(key->name, hash_cur->key.name)) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
hash_del_rcu(&hash_cur->hlist);
hlist_add_head(&hash_cur->dlist, &free_list);
}
}
hash_for_each_possible_rcu(package_to_appid, hash_cur, hlist, hash) {
- if (!strcasecmp(key->name, hash_cur->key.name)) {
+ if (qstr_case_eq(key, &hash_cur->key)) {
hash_del_rcu(&hash_cur->hlist);
hlist_add_head(&hash_cur->dlist, &free_list);
break;
@@ -368,7 +370,7 @@
unsigned int hash = key->hash;
hash_for_each_possible_rcu(ext_to_groupid, hash_cur, hlist, hash) {
- if (!strcasecmp(key->name, hash_cur->key.name) && atomic_read(&hash_cur->value) == group) {
+ if (qstr_case_eq(key, &hash_cur->key) && atomic_read(&hash_cur->value) == group) {
hash_del_rcu(&hash_cur->hlist);
synchronize_rcu();
free_hashtable_entry(hash_cur);
@@ -419,7 +421,7 @@
unsigned int hash = key->hash;
hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
- if (!strcasecmp(key->name, hash_cur->key.name) &&
+ if (qstr_case_eq(key, &hash_cur->key) &&
atomic_read(&hash_cur->value) == userid) {
hash_del_rcu(&hash_cur->hlist);
synchronize_rcu();
@@ -528,7 +530,7 @@
rcu_read_lock();
hash_for_each_possible_rcu(package_to_userid, hash_cur, hlist, hash) {
- if (!strcasecmp(package_details->name.name, hash_cur->key.name))
+ if (qstr_case_eq(&package_details->name, &hash_cur->key))
count += scnprintf(page + count, PAGE_SIZE - count,
"%d ", atomic_read(&hash_cur->value));
}
@@ -757,7 +759,7 @@
hash_cur_app->key.name, atomic_read(&hash_cur_app->value));
hash = hash_cur_app->key.hash;
hash_for_each_possible_rcu(package_to_userid, hash_cur_user, hlist, hash) {
- if (!strcasecmp(hash_cur_app->key.name, hash_cur_user->key.name)) {
+ if (qstr_case_eq(&hash_cur_app->key, &hash_cur_user->key)) {
written += scnprintf(page + count + written - 1,
PAGE_SIZE - sizeof(errormsg) - count - written + 1,
" %d\n", atomic_read(&hash_cur_user->value)) - 1;
diff --git a/fs/sdcardfs/sdcardfs.h b/fs/sdcardfs/sdcardfs.h
index 03da961..f3cced3 100644
--- a/fs/sdcardfs/sdcardfs.h
+++ b/fs/sdcardfs/sdcardfs.h
@@ -459,7 +459,7 @@
extern appid_t get_appid(const char *app_name);
extern appid_t get_ext_gid(const char *app_name);
extern appid_t is_excluded(const char *app_name, userid_t userid);
-extern int check_caller_access_to_name(struct inode *parent_node, const char* name);
+extern int check_caller_access_to_name(struct inode *parent_node, const struct qstr* name);
extern int open_flags_to_access_mode(int open_flags);
extern int packagelist_init(void);
extern void packagelist_exit(void);
@@ -477,7 +477,7 @@
extern void setup_derived_state(struct inode *inode, perm_t perm, userid_t userid,
uid_t uid, bool under_android, struct inode *top);
extern void get_derived_permission(struct dentry *parent, struct dentry *dentry);
-extern void get_derived_permission_new(struct dentry *parent, struct dentry *dentry, const char *name);
+extern void get_derived_permission_new(struct dentry *parent, struct dentry *dentry, const struct qstr *name);
extern void drop_recursive(struct dentry *parent);
extern void fixup_top_recursive(struct dentry *parent);
extern void fixup_perms_recursive(struct dentry *dentry, struct limit_search *limit);
@@ -605,4 +605,17 @@
dest->i_flags = src->i_flags;
set_nlink(dest, src->i_nlink);
}
+
+static inline bool str_case_eq(const char *s1, const char *s2)
+{
+ return !strcasecmp(s1, s2);
+}
+
+static inline bool qstr_case_eq(const struct qstr *q1, const struct qstr *q2)
+{
+ return q1->len == q2->len && str_case_eq(q1->name, q2->name);
+}
+
+#define QSTR_LITERAL(string) QSTR_INIT(string, sizeof(string)-1)
+
#endif /* not _SDCARDFS_H_ */
