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 <linux/unaligned.h> 13 #include "fs_context.h" 14 #include "cifsglob.h" 15 #include "../common/smbfsctl.h" 16 17 #define REPARSE_SYM_PATH_MAX 4060 18 19 /* 20 * Used only by cifs.ko to ignore reparse points from files when client or 21 * server doesn't support FSCTL_GET_REPARSE_POINT. 22 */ 23 #define IO_REPARSE_TAG_INTERNAL ((__u32)~0U) 24 25 static inline dev_t reparse_mkdev(void *ptr) 26 { 27 u64 v = get_unaligned_le64(ptr); 28 29 return MKDEV(v & 0xffffffff, v >> 32); 30 } 31 32 static inline kuid_t wsl_make_kuid(struct cifs_sb_info *cifs_sb, 33 void *ptr) 34 { 35 u32 uid = get_unaligned_le32(ptr); 36 37 if (cifs_sb_flags(cifs_sb) & CIFS_MOUNT_OVERR_UID) 38 return cifs_sb->ctx->linux_uid; 39 return make_kuid(current_user_ns(), uid); 40 } 41 42 static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb, 43 void *ptr) 44 { 45 u32 gid = get_unaligned_le32(ptr); 46 47 if (cifs_sb_flags(cifs_sb) & CIFS_MOUNT_OVERR_GID) 48 return cifs_sb->ctx->linux_gid; 49 return make_kgid(current_user_ns(), gid); 50 } 51 52 static inline u64 reparse_mode_nfs_type(mode_t mode) 53 { 54 switch (mode & S_IFMT) { 55 case S_IFLNK: return NFS_SPECFILE_LNK; 56 case S_IFBLK: return NFS_SPECFILE_BLK; 57 case S_IFCHR: return NFS_SPECFILE_CHR; 58 case S_IFIFO: return NFS_SPECFILE_FIFO; 59 case S_IFSOCK: return NFS_SPECFILE_SOCK; 60 } 61 return 0; 62 } 63 64 static inline u32 reparse_mode_wsl_tag(mode_t mode) 65 { 66 switch (mode & S_IFMT) { 67 case S_IFLNK: return IO_REPARSE_TAG_LX_SYMLINK; 68 case S_IFBLK: return IO_REPARSE_TAG_LX_BLK; 69 case S_IFCHR: return IO_REPARSE_TAG_LX_CHR; 70 case S_IFIFO: return IO_REPARSE_TAG_LX_FIFO; 71 case S_IFSOCK: return IO_REPARSE_TAG_AF_UNIX; 72 } 73 return 0; 74 } 75 76 /* 77 * Match a reparse point inode if reparse tag and ctime haven't changed. 78 * 79 * Windows Server updates ctime of reparse points when their data have changed. 80 * The server doesn't allow changing reparse tags from existing reparse points, 81 * though it's worth checking. 82 */ 83 static inline bool reparse_inode_match(struct inode *inode, 84 struct cifs_fattr *fattr) 85 { 86 struct cifsInodeInfo *cinode = CIFS_I(inode); 87 struct timespec64 ctime = inode_get_ctime(inode); 88 89 /* 90 * Do not match reparse tags when client or server doesn't support 91 * FSCTL_GET_REPARSE_POINT. @fattr->cf_cifstag should contain correct 92 * reparse tag from query dir response but the client won't be able to 93 * read the reparse point data anyway. This spares us a revalidation. 94 */ 95 if (cinode->reparse_tag != IO_REPARSE_TAG_INTERNAL && 96 cinode->reparse_tag != fattr->cf_cifstag) 97 return false; 98 return (cinode->cifsAttrs & ATTR_REPARSE_POINT) && 99 timespec64_equal(&ctime, &fattr->cf_ctime); 100 } 101 102 static inline u32 cifs_open_data_attrs(const struct cifs_open_info_data *data) 103 { 104 if (data->contains_posix_file_info) 105 return le32_to_cpu(data->posix_fi.DosAttributes); 106 107 return le32_to_cpu(data->fi.Attributes); 108 } 109 110 static inline bool cifs_open_data_reparse(struct cifs_open_info_data *data) 111 { 112 u32 attrs = cifs_open_data_attrs(data); 113 114 if (data->contains_posix_file_info) { 115 struct smb311_posix_qinfo *fi = &data->posix_fi; 116 117 if (data->reparse_point) { 118 attrs |= ATTR_REPARSE_POINT; 119 fi->DosAttributes = cpu_to_le32(attrs); 120 } 121 122 } else { 123 struct smb2_file_all_info *fi = &data->fi; 124 125 if (data->reparse_point) { 126 attrs |= ATTR_REPARSE_POINT; 127 fi->Attributes = cpu_to_le32(attrs); 128 } 129 } 130 131 return attrs & ATTR_REPARSE_POINT; 132 } 133 134 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb, 135 struct cifs_fattr *fattr, 136 struct cifs_open_info_data *data); 137 int create_reparse_symlink(const unsigned int xid, struct inode *inode, 138 struct dentry *dentry, struct cifs_tcon *tcon, 139 const char *full_path, const char *symname); 140 int mknod_reparse(unsigned int xid, struct inode *inode, struct dentry *dentry, 141 struct cifs_tcon *tcon, const char *full_path, umode_t mode, 142 dev_t dev); 143 struct reparse_data_buffer *smb2_get_reparse_point_buffer(const struct kvec *rsp_iov, 144 u32 *plen); 145 146 #endif /* _CIFS_REPARSE_H */ 147