xref: /linux/fs/smb/client/reparse.h (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (c) 2024 Paulo Alcantara <pc@manguebit.com>
4  */
5 
6 #ifndef _CIFS_REPARSE_H
7 #define _CIFS_REPARSE_H
8 
9 #include <linux/fs.h>
10 #include <linux/stat.h>
11 #include <linux/uidgid.h>
12 #include "fs_context.h"
13 #include "cifsglob.h"
14 
15 static inline dev_t reparse_nfs_mkdev(struct reparse_posix_data *buf)
16 {
17 	u64 v = le64_to_cpu(*(__le64 *)buf->DataBuffer);
18 
19 	return MKDEV(v >> 32, v & 0xffffffff);
20 }
21 
22 static inline dev_t wsl_mkdev(void *ptr)
23 {
24 	u64 v = le64_to_cpu(*(__le64 *)ptr);
25 
26 	return MKDEV(v & 0xffffffff, v >> 32);
27 }
28 
29 static inline kuid_t wsl_make_kuid(struct cifs_sb_info *cifs_sb,
30 				   void *ptr)
31 {
32 	u32 uid = le32_to_cpu(*(__le32 *)ptr);
33 
34 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
35 		return cifs_sb->ctx->linux_uid;
36 	return make_kuid(current_user_ns(), uid);
37 }
38 
39 static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb,
40 				   void *ptr)
41 {
42 	u32 gid = le32_to_cpu(*(__le32 *)ptr);
43 
44 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
45 		return cifs_sb->ctx->linux_gid;
46 	return make_kgid(current_user_ns(), gid);
47 }
48 
49 static inline u64 reparse_mode_nfs_type(mode_t mode)
50 {
51 	switch (mode & S_IFMT) {
52 	case S_IFBLK: return NFS_SPECFILE_BLK;
53 	case S_IFCHR: return NFS_SPECFILE_CHR;
54 	case S_IFIFO: return NFS_SPECFILE_FIFO;
55 	case S_IFSOCK: return NFS_SPECFILE_SOCK;
56 	}
57 	return 0;
58 }
59 
60 static inline u32 reparse_mode_wsl_tag(mode_t mode)
61 {
62 	switch (mode & S_IFMT) {
63 	case S_IFBLK: return IO_REPARSE_TAG_LX_BLK;
64 	case S_IFCHR: return IO_REPARSE_TAG_LX_CHR;
65 	case S_IFIFO: return IO_REPARSE_TAG_LX_FIFO;
66 	case S_IFSOCK: return IO_REPARSE_TAG_AF_UNIX;
67 	}
68 	return 0;
69 }
70 
71 /*
72  * Match a reparse point inode if reparse tag and ctime haven't changed.
73  *
74  * Windows Server updates ctime of reparse points when their data have changed.
75  * The server doesn't allow changing reparse tags from existing reparse points,
76  * though it's worth checking.
77  */
78 static inline bool reparse_inode_match(struct inode *inode,
79 				       struct cifs_fattr *fattr)
80 {
81 	struct timespec64 ctime = inode_get_ctime(inode);
82 
83 	return (CIFS_I(inode)->cifsAttrs & ATTR_REPARSE) &&
84 		CIFS_I(inode)->reparse_tag == fattr->cf_cifstag &&
85 		timespec64_equal(&ctime, &fattr->cf_ctime);
86 }
87 
88 static inline bool cifs_open_data_reparse(struct cifs_open_info_data *data)
89 {
90 	struct smb2_file_all_info *fi = &data->fi;
91 	u32 attrs = le32_to_cpu(fi->Attributes);
92 	bool ret;
93 
94 	ret = data->reparse_point || (attrs & ATTR_REPARSE);
95 	if (ret)
96 		attrs |= ATTR_REPARSE;
97 	fi->Attributes = cpu_to_le32(attrs);
98 	return ret;
99 }
100 
101 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb,
102 				 struct cifs_fattr *fattr,
103 				 struct cifs_open_info_data *data);
104 int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
105 				struct dentry *dentry, struct cifs_tcon *tcon,
106 				const char *full_path, const char *symname);
107 int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
108 		       struct dentry *dentry, struct cifs_tcon *tcon,
109 		       const char *full_path, umode_t mode, dev_t dev);
110 int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb, struct kvec *rsp_iov,
111 			     struct cifs_open_info_data *data);
112 
113 #endif /* _CIFS_REPARSE_H */
114