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 #define REPARSE_SYM_PATH_MAX 4060
16
17 /*
18 * Used only by cifs.ko to ignore reparse points from files when client or
19 * server doesn't support FSCTL_GET_REPARSE_POINT.
20 */
21 #define IO_REPARSE_TAG_INTERNAL ((__u32)~0U)
22
reparse_mkdev(void * ptr)23 static inline dev_t reparse_mkdev(void *ptr)
24 {
25 u64 v = le64_to_cpu(*(__le64 *)ptr);
26
27 return MKDEV(v & 0xffffffff, v >> 32);
28 }
29
wsl_make_kuid(struct cifs_sb_info * cifs_sb,void * ptr)30 static inline kuid_t wsl_make_kuid(struct cifs_sb_info *cifs_sb,
31 void *ptr)
32 {
33 u32 uid = le32_to_cpu(*(__le32 *)ptr);
34
35 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
36 return cifs_sb->ctx->linux_uid;
37 return make_kuid(current_user_ns(), uid);
38 }
39
wsl_make_kgid(struct cifs_sb_info * cifs_sb,void * ptr)40 static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb,
41 void *ptr)
42 {
43 u32 gid = le32_to_cpu(*(__le32 *)ptr);
44
45 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
46 return cifs_sb->ctx->linux_gid;
47 return make_kgid(current_user_ns(), gid);
48 }
49
reparse_mode_nfs_type(mode_t mode)50 static inline u64 reparse_mode_nfs_type(mode_t mode)
51 {
52 switch (mode & S_IFMT) {
53 case S_IFBLK: return NFS_SPECFILE_BLK;
54 case S_IFCHR: return NFS_SPECFILE_CHR;
55 case S_IFIFO: return NFS_SPECFILE_FIFO;
56 case S_IFSOCK: return NFS_SPECFILE_SOCK;
57 }
58 return 0;
59 }
60
reparse_mode_wsl_tag(mode_t mode)61 static inline u32 reparse_mode_wsl_tag(mode_t mode)
62 {
63 switch (mode & S_IFMT) {
64 case S_IFBLK: return IO_REPARSE_TAG_LX_BLK;
65 case S_IFCHR: return IO_REPARSE_TAG_LX_CHR;
66 case S_IFIFO: return IO_REPARSE_TAG_LX_FIFO;
67 case S_IFSOCK: return IO_REPARSE_TAG_AF_UNIX;
68 }
69 return 0;
70 }
71
72 /*
73 * Match a reparse point inode if reparse tag and ctime haven't changed.
74 *
75 * Windows Server updates ctime of reparse points when their data have changed.
76 * The server doesn't allow changing reparse tags from existing reparse points,
77 * though it's worth checking.
78 */
reparse_inode_match(struct inode * inode,struct cifs_fattr * fattr)79 static inline bool reparse_inode_match(struct inode *inode,
80 struct cifs_fattr *fattr)
81 {
82 struct cifsInodeInfo *cinode = CIFS_I(inode);
83 struct timespec64 ctime = inode_get_ctime(inode);
84
85 /*
86 * Do not match reparse tags when client or server doesn't support
87 * FSCTL_GET_REPARSE_POINT. @fattr->cf_cifstag should contain correct
88 * reparse tag from query dir response but the client won't be able to
89 * read the reparse point data anyway. This spares us a revalidation.
90 */
91 if (cinode->reparse_tag != IO_REPARSE_TAG_INTERNAL &&
92 cinode->reparse_tag != fattr->cf_cifstag)
93 return false;
94 return (cinode->cifsAttrs & ATTR_REPARSE) &&
95 timespec64_equal(&ctime, &fattr->cf_ctime);
96 }
97
cifs_open_data_reparse(struct cifs_open_info_data * data)98 static inline bool cifs_open_data_reparse(struct cifs_open_info_data *data)
99 {
100 u32 attrs;
101 bool ret;
102
103 if (data->contains_posix_file_info) {
104 struct smb311_posix_qinfo *fi = &data->posix_fi;
105
106 attrs = le32_to_cpu(fi->DosAttributes);
107 if (data->reparse_point) {
108 attrs |= ATTR_REPARSE;
109 fi->DosAttributes = cpu_to_le32(attrs);
110 }
111
112 } else {
113 struct smb2_file_all_info *fi = &data->fi;
114
115 attrs = le32_to_cpu(fi->Attributes);
116 if (data->reparse_point) {
117 attrs |= ATTR_REPARSE;
118 fi->Attributes = cpu_to_le32(attrs);
119 }
120 }
121
122 ret = attrs & ATTR_REPARSE;
123
124 return ret;
125 }
126
127 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb,
128 struct cifs_fattr *fattr,
129 struct cifs_open_info_data *data);
130 int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
131 struct dentry *dentry, struct cifs_tcon *tcon,
132 const char *full_path, const char *symname);
133 int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
134 struct dentry *dentry, struct cifs_tcon *tcon,
135 const char *full_path, umode_t mode, dev_t dev);
136 int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb,
137 const char *full_path,
138 struct kvec *rsp_iov,
139 struct cifs_open_info_data *data);
140
141 #endif /* _CIFS_REPARSE_H */
142