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 /*
16 * Used only by cifs.ko to ignore reparse points from files when client or
17 * server doesn't support FSCTL_GET_REPARSE_POINT.
18 */
19 #define IO_REPARSE_TAG_INTERNAL ((__u32)~0U)
20
reparse_mkdev(void * ptr)21 static inline dev_t reparse_mkdev(void *ptr)
22 {
23 u64 v = le64_to_cpu(*(__le64 *)ptr);
24
25 return MKDEV(v & 0xffffffff, v >> 32);
26 }
27
wsl_make_kuid(struct cifs_sb_info * cifs_sb,void * ptr)28 static inline kuid_t wsl_make_kuid(struct cifs_sb_info *cifs_sb,
29 void *ptr)
30 {
31 u32 uid = le32_to_cpu(*(__le32 *)ptr);
32
33 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
34 return cifs_sb->ctx->linux_uid;
35 return make_kuid(current_user_ns(), uid);
36 }
37
wsl_make_kgid(struct cifs_sb_info * cifs_sb,void * ptr)38 static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb,
39 void *ptr)
40 {
41 u32 gid = le32_to_cpu(*(__le32 *)ptr);
42
43 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
44 return cifs_sb->ctx->linux_gid;
45 return make_kgid(current_user_ns(), gid);
46 }
47
reparse_mode_nfs_type(mode_t mode)48 static inline u64 reparse_mode_nfs_type(mode_t mode)
49 {
50 switch (mode & S_IFMT) {
51 case S_IFBLK: return NFS_SPECFILE_BLK;
52 case S_IFCHR: return NFS_SPECFILE_CHR;
53 case S_IFIFO: return NFS_SPECFILE_FIFO;
54 case S_IFSOCK: return NFS_SPECFILE_SOCK;
55 }
56 return 0;
57 }
58
reparse_mode_wsl_tag(mode_t mode)59 static inline u32 reparse_mode_wsl_tag(mode_t mode)
60 {
61 switch (mode & S_IFMT) {
62 case S_IFBLK: return IO_REPARSE_TAG_LX_BLK;
63 case S_IFCHR: return IO_REPARSE_TAG_LX_CHR;
64 case S_IFIFO: return IO_REPARSE_TAG_LX_FIFO;
65 case S_IFSOCK: return IO_REPARSE_TAG_AF_UNIX;
66 }
67 return 0;
68 }
69
70 /*
71 * Match a reparse point inode if reparse tag and ctime haven't changed.
72 *
73 * Windows Server updates ctime of reparse points when their data have changed.
74 * The server doesn't allow changing reparse tags from existing reparse points,
75 * though it's worth checking.
76 */
reparse_inode_match(struct inode * inode,struct cifs_fattr * fattr)77 static inline bool reparse_inode_match(struct inode *inode,
78 struct cifs_fattr *fattr)
79 {
80 struct cifsInodeInfo *cinode = CIFS_I(inode);
81 struct timespec64 ctime = inode_get_ctime(inode);
82
83 /*
84 * Do not match reparse tags when client or server doesn't support
85 * FSCTL_GET_REPARSE_POINT. @fattr->cf_cifstag should contain correct
86 * reparse tag from query dir response but the client won't be able to
87 * read the reparse point data anyway. This spares us a revalidation.
88 */
89 if (cinode->reparse_tag != IO_REPARSE_TAG_INTERNAL &&
90 cinode->reparse_tag != fattr->cf_cifstag)
91 return false;
92 return (cinode->cifsAttrs & ATTR_REPARSE) &&
93 timespec64_equal(&ctime, &fattr->cf_ctime);
94 }
95
cifs_open_data_reparse(struct cifs_open_info_data * data)96 static inline bool cifs_open_data_reparse(struct cifs_open_info_data *data)
97 {
98 struct smb2_file_all_info *fi = &data->fi;
99 u32 attrs = le32_to_cpu(fi->Attributes);
100 bool ret;
101
102 ret = data->reparse_point || (attrs & ATTR_REPARSE);
103 if (ret)
104 attrs |= ATTR_REPARSE;
105 fi->Attributes = cpu_to_le32(attrs);
106 return ret;
107 }
108
109 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb,
110 struct cifs_fattr *fattr,
111 struct cifs_open_info_data *data);
112 int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
113 struct dentry *dentry, struct cifs_tcon *tcon,
114 const char *full_path, const char *symname);
115 int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
116 struct dentry *dentry, struct cifs_tcon *tcon,
117 const char *full_path, umode_t mode, dev_t dev);
118 int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb, struct kvec *rsp_iov,
119 struct cifs_open_info_data *data);
120
121 #endif /* _CIFS_REPARSE_H */
122