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 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 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 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 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 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 */ 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 98 static inline bool cifs_open_data_reparse(struct cifs_open_info_data *data) 99 { 100 struct smb2_file_all_info *fi = &data->fi; 101 u32 attrs = le32_to_cpu(fi->Attributes); 102 bool ret; 103 104 ret = data->reparse_point || (attrs & ATTR_REPARSE); 105 if (ret) 106 attrs |= ATTR_REPARSE; 107 fi->Attributes = cpu_to_le32(attrs); 108 return ret; 109 } 110 111 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb, 112 struct cifs_fattr *fattr, 113 struct cifs_open_info_data *data); 114 int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode, 115 struct dentry *dentry, struct cifs_tcon *tcon, 116 const char *full_path, const char *symname); 117 int smb2_mknod_reparse(unsigned int xid, struct inode *inode, 118 struct dentry *dentry, struct cifs_tcon *tcon, 119 const char *full_path, umode_t mode, dev_t dev); 120 int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb, 121 const char *full_path, 122 struct kvec *rsp_iov, 123 struct cifs_open_info_data *data); 124 125 #endif /* _CIFS_REPARSE_H */ 126