SMB3: Add support for getting and setting SACLs

Add SYSTEM_SECURITY access flag and use with smb2 when opening
files for getting/setting SACLs. Add "system.cifs_ntsd_full"
extended attribute to allow user-space access to the functionality.
Avoid multiple server calls when setting owner, DACL, and SACL.

Signed-off-by: Boris Protopopov <pboris@amazon.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 19 insertions, 12 deletions

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 949cd1177147..4a1761139e00 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3214,7 +3214,7 @@ smb2_query_reparse_tag(const unsigned int xid, struct cifs_tcon *tcon,
 
 static struct cifs_ntsd *
 get_smb2_acl_by_fid(struct cifs_sb_info *cifs_sb,
-		const struct cifs_fid *cifsfid, u32 *pacllen)
+		    const struct cifs_fid *cifsfid, u32 *pacllen, u32 info)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	unsigned int xid;
@@ -3228,7 +3228,8 @@ get_smb2_acl_by_fid(struct cifs_sb_info *cifs_sb,
 	cifs_dbg(FYI, "trying to get acl\n");
 
 	rc = SMB2_query_acl(xid, tlink_tcon(tlink), cifsfid->persistent_fid,
-			    cifsfid->volatile_fid, (void **)&pntsd, pacllen);
+			    cifsfid->volatile_fid, (void **)&pntsd, pacllen,
+			    info);
 	free_xid(xid);
 
 	cifs_put_tlink(tlink);
@@ -3242,7 +3243,7 @@ get_smb2_acl_by_fid(struct cifs_sb_info *cifs_sb,
 
 static struct cifs_ntsd *
 get_smb2_acl_by_path(struct cifs_sb_info *cifs_sb,
-		const char *path, u32 *pacllen)
+		     const char *path, u32 *pacllen, u32 info)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
@@ -3280,12 +3281,16 @@ get_smb2_acl_by_path(struct cifs_sb_info *cifs_sb,
 	oparms.fid = &fid;
 	oparms.reconnect = false;
 
+	if (info & SACL_SECINFO)
+		oparms.desired_access |= SYSTEM_SECURITY;
+
 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL,
 		       NULL);
 	kfree(utf16_path);
 	if (!rc) {
 		rc = SMB2_query_acl(xid, tlink_tcon(tlink), fid.persistent_fid,
-			    fid.volatile_fid, (void **)&pntsd, pacllen);
+				    fid.volatile_fid, (void **)&pntsd, pacllen,
+				    info);
 		SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
 	}
 
@@ -3319,10 +3324,12 @@ set_smb2_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
 	tcon = tlink_tcon(tlink);
 	xid = get_xid();
 
-	if (aclflag == CIFS_ACL_OWNER || aclflag == CIFS_ACL_GROUP)
-		access_flags = WRITE_OWNER;
-	else
-		access_flags = WRITE_DAC;
+	if (aclflag & CIFS_ACL_OWNER || aclflag & CIFS_ACL_GROUP)
+		access_flags |= WRITE_OWNER;
+	if (aclflag & CIFS_ACL_SACL)
+		access_flags |= SYSTEM_SECURITY;
+	if (aclflag & CIFS_ACL_DACL)
+		access_flags |= WRITE_DAC;
 
 	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
 	if (!utf16_path) {
@@ -3356,8 +3363,8 @@ set_smb2_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
 /* Retrieve an ACL from the server */
 static struct cifs_ntsd *
 get_smb2_acl(struct cifs_sb_info *cifs_sb,
-				      struct inode *inode, const char *path,
-				      u32 *pacllen)
+	     struct inode *inode, const char *path,
+	     u32 *pacllen, u32 info)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	struct cifsFileInfo *open_file = NULL;
@@ -3365,9 +3372,9 @@ get_smb2_acl(struct cifs_sb_info *cifs_sb,
 	if (inode)
 		open_file = find_readable_file(CIFS_I(inode), true);
 	if (!open_file)
-		return get_smb2_acl_by_path(cifs_sb, path, pacllen);
+		return get_smb2_acl_by_path(cifs_sb, path, pacllen, info);
 
-	pntsd = get_smb2_acl_by_fid(cifs_sb, &open_file->fid, pacllen);
+	pntsd = get_smb2_acl_by_fid(cifs_sb, &open_file->fid, pacllen, info);
 	cifsFileInfo_put(open_file);
 	return pntsd;
 }