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 #include "../common/smbfsctl.h" 15 16 #define REPARSE_SYM_PATH_MAX 4060 17 18 /* 19 * Used only by cifs.ko to ignore reparse points from files when client or 20 * server doesn't support FSCTL_GET_REPARSE_POINT. 21 */ 22 #define IO_REPARSE_TAG_INTERNAL ((__u32)~0U) 23 24 static inline dev_t reparse_mkdev(void *ptr) 25 { 26 u64 v = le64_to_cpu(*(__le64 *)ptr); 27 28 return MKDEV(v & 0xffffffff, v >> 32); 29 } 30 31 static inline kuid_t wsl_make_kuid(struct cifs_sb_info *cifs_sb, 32 void *ptr) 33 { 34 u32 uid = le32_to_cpu(*(__le32 *)ptr); 35 36 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID) 37 return cifs_sb->ctx->linux_uid; 38 return make_kuid(current_user_ns(), uid); 39 } 40 41 static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb, 42 void *ptr) 43 { 44 u32 gid = le32_to_cpu(*(__le32 *)ptr); 45 46 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID) 47 return cifs_sb->ctx->linux_gid; 48 return make_kgid(current_user_ns(), gid); 49 } 50 51 static inline u64 reparse_mode_nfs_type(mode_t mode) 52 { 53 switch (mode & S_IFMT) { 54 case S_IFLNK: return NFS_SPECFILE_LNK; 55 case S_IFBLK: return NFS_SPECFILE_BLK; 56 case S_IFCHR: return NFS_SPECFILE_CHR; 57 case S_IFIFO: return NFS_SPECFILE_FIFO; 58 case S_IFSOCK: return NFS_SPECFILE_SOCK; 59 } 60 return 0; 61 } 62 63 static inline u32 reparse_mode_wsl_tag(mode_t mode) 64 { 65 switch (mode & S_IFMT) { 66 case S_IFLNK: return IO_REPARSE_TAG_LX_SYMLINK; 67 case S_IFBLK: return IO_REPARSE_TAG_LX_BLK; 68 case S_IFCHR: return IO_REPARSE_TAG_LX_CHR; 69 case S_IFIFO: return IO_REPARSE_TAG_LX_FIFO; 70 case S_IFSOCK: return IO_REPARSE_TAG_AF_UNIX; 71 } 72 return 0; 73 } 74 75 /* 76 * Match a reparse point inode if reparse tag and ctime haven't changed. 77 * 78 * Windows Server updates ctime of reparse points when their data have changed. 79 * The server doesn't allow changing reparse tags from existing reparse points, 80 * though it's worth checking. 81 */ 82 static inline bool reparse_inode_match(struct inode *inode, 83 struct cifs_fattr *fattr) 84 { 85 struct cifsInodeInfo *cinode = CIFS_I(inode); 86 struct timespec64 ctime = inode_get_ctime(inode); 87 88 /* 89 * Do not match reparse tags when client or server doesn't support 90 * FSCTL_GET_REPARSE_POINT. @fattr->cf_cifstag should contain correct 91 * reparse tag from query dir response but the client won't be able to 92 * read the reparse point data anyway. This spares us a revalidation. 93 */ 94 if (cinode->reparse_tag != IO_REPARSE_TAG_INTERNAL && 95 cinode->reparse_tag != fattr->cf_cifstag) 96 return false; 97 return (cinode->cifsAttrs & ATTR_REPARSE_POINT) && 98 timespec64_equal(&ctime, &fattr->cf_ctime); 99 } 100 101 static inline bool cifs_open_data_reparse(struct cifs_open_info_data *data) 102 { 103 u32 attrs; 104 bool ret; 105 106 if (data->contains_posix_file_info) { 107 struct smb311_posix_qinfo *fi = &data->posix_fi; 108 109 attrs = le32_to_cpu(fi->DosAttributes); 110 if (data->reparse_point) { 111 attrs |= ATTR_REPARSE_POINT; 112 fi->DosAttributes = cpu_to_le32(attrs); 113 } 114 115 } else { 116 struct smb2_file_all_info *fi = &data->fi; 117 118 attrs = le32_to_cpu(fi->Attributes); 119 if (data->reparse_point) { 120 attrs |= ATTR_REPARSE_POINT; 121 fi->Attributes = cpu_to_le32(attrs); 122 } 123 } 124 125 ret = attrs & ATTR_REPARSE_POINT; 126 127 return ret; 128 } 129 130 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb, 131 struct cifs_fattr *fattr, 132 struct cifs_open_info_data *data); 133 int create_reparse_symlink(const unsigned int xid, struct inode *inode, 134 struct dentry *dentry, struct cifs_tcon *tcon, 135 const char *full_path, const char *symname); 136 int mknod_reparse(unsigned int xid, struct inode *inode, struct dentry *dentry, 137 struct cifs_tcon *tcon, const char *full_path, umode_t mode, 138 dev_t dev); 139 struct reparse_data_buffer *smb2_get_reparse_point_buffer(const struct kvec *rsp_iov, 140 u32 *plen); 141 142 #endif /* _CIFS_REPARSE_H */ 143