feat: ability to manipulate extended attribute

[lunaix-os.git] / lunaix-os / kernel / fs / xattr.c

diff --git a/lunaix-os/kernel/fs/xattr.c b/lunaix-os/kernel/fs/xattr.c
new file mode 100644 (file)
index 0000000..94f85b7
--- /dev/null
+++ b/lunaix-os/kernel/fs/xattr.c
@@ -0,0 +1,257 @@
+#include <klibc/string.h>
+#include <lunaix/fs.h>
+#include <lunaix/mm/valloc.h>
+#include <lunaix/syscall.h>
+
+struct v_xattr_entry*
+xattr_new(struct hstr* name)
+{
+    struct v_xattr_entry* entry = valloc(sizeof(*entry));
+    if (!entry) {
+        return NULL;
+    }
+    *entry =
+      (struct v_xattr_entry){ .name = HHSTR(valloc(VFS_NAME_MAXLEN), 0, 0) };
+
+    hstrcpy(&entry->name, name);
+    return entry;
+}
+
+void
+xattr_free(struct v_xattr_entry* entry)
+{
+    vfree(entry->name.value);
+    vfree(entry);
+}
+
+struct v_xattr_entry*
+xattr_getcache(struct v_inode* inode, struct hstr* name)
+{
+    struct v_xattr_entry *pos, *n;
+    llist_for_each(pos, n, &inode->xattrs, entries)
+    {
+        if (HSTR_EQ(&pos->name, name)) {
+            return pos;
+        }
+    }
+
+    return NULL;
+}
+
+void
+xattr_addcache(struct v_inode* inode, struct v_xattr_entry* xattr)
+{
+    llist_append(&inode->xattrs, &xattr->entries);
+}
+
+void
+xattr_delcache(struct v_inode* inode, struct v_xattr_entry* xattr)
+{
+    llist_delete(&xattr->entries);
+}
+
+int
+__vfs_getxattr(struct v_inode* inode,
+               struct v_xattr_entry** xentry,
+               const char* name)
+{
+    if (!inode->ops->getxattr) {
+        return ENOTSUP;
+    }
+
+    int errno = 0;
+    size_t len = strlen(name);
+
+    if (len > VFS_NAME_MAXLEN) {
+        return ERANGE;
+    }
+
+    struct hstr hname = HSTR(name, len);
+
+    hstr_rehash(&hname, HSTR_FULL_HASH);
+
+    struct v_xattr_entry* entry = xattr_getcache(inode, &hname);
+    if (!entry) {
+        if (!(entry = xattr_new(&hname))) {
+            return ENOMEM;
+        }
+    }
+
+    if (!(errno = inode->ops->getxattr(inode, entry))) {
+        *xentry = entry;
+        xattr_addcache(inode, entry);
+    } else {
+        xattr_free(entry);
+    }
+    return errno;
+}
+
+int
+__vfs_setxattr(struct v_inode* inode,
+               const char* name,
+               const void* data,
+               size_t len)
+{
+    if (!inode->ops->setxattr || !inode->ops->delxattr) {
+        return ENOTSUP;
+    }
+
+    int errno = 0;
+    size_t slen = strlen(name);
+
+    if (slen > VFS_NAME_MAXLEN) {
+        return ERANGE;
+    }
+
+    struct hstr hname = HSTR(name, slen);
+
+    hstr_rehash(&hname, HSTR_FULL_HASH);
+
+    struct v_xattr_entry* entry = xattr_getcache(inode, &hname);
+    if (!entry) {
+        if (!(entry = xattr_new(&hname))) {
+            return ENOMEM;
+        }
+    } else {
+        xattr_delcache(inode, entry);
+    }
+
+    if ((errno = inode->ops->delxattr(inode, entry))) {
+        xattr_free(entry);
+        goto done;
+    }
+
+    entry->value = data;
+    entry->len = len;
+
+    if ((errno = inode->ops->setxattr(inode, entry))) {
+        xattr_free(entry);
+        goto done;
+    }
+
+    xattr_addcache(inode, entry);
+done:
+    return errno;
+}
+
+__DEFINE_LXSYSCALL4(int,
+                    getxattr,
+                    const char*,
+                    path,
+                    const char*,
+                    name,
+                    void*,
+                    value,
+                    size_t,
+                    len)
+{
+    struct v_dnode* dnode;
+    struct v_xattr_entry* xattr;
+    int errno = 0;
+
+    if ((errno = vfs_walk_proc(path, &dnode, NULL, 0))) {
+        goto done;
+    }
+
+    if ((errno = __vfs_getxattr(dnode->inode, &xattr, name))) {
+        goto done;
+    }
+
+    if (len < xattr->len) {
+        errno = ERANGE;
+        goto done;
+    }
+
+    memcpy(value, xattr->value, len);
+
+done:
+    return DO_STATUS(errno);
+}
+
+__DEFINE_LXSYSCALL4(int,
+                    setxattr,
+                    const char*,
+                    path,
+                    const char*,
+                    name,
+                    void*,
+                    value,
+                    size_t,
+                    len)
+{
+    struct v_dnode* dnode;
+    struct v_xattr_entry* xattr;
+    int errno = 0;
+
+    if ((errno = vfs_walk_proc(path, &dnode, NULL, 0))) {
+        goto done;
+    }
+
+    if ((errno = __vfs_setxattr(dnode->inode, name, value, len))) {
+        goto done;
+    }
+
+done:
+    return DO_STATUS(errno);
+}
+
+__DEFINE_LXSYSCALL4(int,
+                    fgetxattr,
+                    int,
+                    fd,
+                    const char*,
+                    name,
+                    void*,
+                    value,
+                    size_t,
+                    len)
+{
+    struct v_fd* fd_s;
+    struct v_xattr_entry* xattr;
+    int errno = 0;
+
+    if ((errno = vfs_getfd(fd, &fd_s))) {
+        goto done;
+    }
+
+    if ((errno = __vfs_getxattr(fd_s->file->inode, &xattr, name))) {
+        goto done;
+    }
+
+    if (len < xattr->len) {
+        errno = ERANGE;
+        goto done;
+    }
+
+    memcpy(value, xattr->value, len);
+
+done:
+    return DO_STATUS(errno);
+}
+
+__DEFINE_LXSYSCALL4(int,
+                    fsetxattr,
+                    int,
+                    fd,
+                    const char*,
+                    name,
+                    void*,
+                    value,
+                    size_t,
+                    len)
+{
+    struct v_fd* fd_s;
+    struct v_xattr_entry* xattr;
+    int errno = 0;
+
+    if ((errno = vfs_getfd(fd, &fd_s))) {
+        goto done;
+    }
+
+    if ((errno = __vfs_setxattr(fd_s->file->inode, name, value, len))) {
+        goto done;
+    }
+
+done:
+    return DO_STATUS(errno);
+}
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