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 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 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 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 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 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 */ 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 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