diff options
Diffstat (limited to 'fs/smb/client/reparse.c')
-rw-r--r-- | fs/smb/client/reparse.c | 956 |
1 files changed, 840 insertions, 116 deletions
diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c index a0ffbda90733..5fa29a97ac15 100644 --- a/fs/smb/client/reparse.c +++ b/fs/smb/client/reparse.c @@ -14,39 +14,198 @@ #include "fs_context.h" #include "reparse.h" +static int mknod_nfs(unsigned int xid, struct inode *inode, + struct dentry *dentry, struct cifs_tcon *tcon, + const char *full_path, umode_t mode, dev_t dev, + const char *symname); + +static int mknod_wsl(unsigned int xid, struct inode *inode, + struct dentry *dentry, struct cifs_tcon *tcon, + const char *full_path, umode_t mode, dev_t dev, + const char *symname); + +static int create_native_symlink(const unsigned int xid, struct inode *inode, + struct dentry *dentry, struct cifs_tcon *tcon, + const char *full_path, const char *symname); + +static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb, + const unsigned int xid, + const char *full_path, + const char *symname, + bool *directory); + int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode, struct dentry *dentry, struct cifs_tcon *tcon, const char *full_path, const char *symname) { + switch (get_cifs_symlink_type(CIFS_SB(inode->i_sb))) { + case CIFS_SYMLINK_TYPE_NATIVE: + return create_native_symlink(xid, inode, dentry, tcon, full_path, symname); + case CIFS_SYMLINK_TYPE_NFS: + return mknod_nfs(xid, inode, dentry, tcon, full_path, S_IFLNK, 0, symname); + case CIFS_SYMLINK_TYPE_WSL: + return mknod_wsl(xid, inode, dentry, tcon, full_path, S_IFLNK, 0, symname); + default: + return -EOPNOTSUPP; + } +} + +static int create_native_symlink(const unsigned int xid, struct inode *inode, + struct dentry *dentry, struct cifs_tcon *tcon, + const char *full_path, const char *symname) +{ struct reparse_symlink_data_buffer *buf = NULL; - struct cifs_open_info_data data; + struct cifs_open_info_data data = {}; struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + const char *symroot = cifs_sb->ctx->symlinkroot; struct inode *new; struct kvec iov; - __le16 *path; - char *sym, sep = CIFS_DIR_SEP(cifs_sb); - u16 len, plen; + __le16 *path = NULL; + bool directory; + char *symlink_target = NULL; + char *sym = NULL; + char sep = CIFS_DIR_SEP(cifs_sb); + u16 len, plen, poff, slen; int rc = 0; - sym = kstrdup(symname, GFP_KERNEL); - if (!sym) - return -ENOMEM; + if (strlen(symname) > REPARSE_SYM_PATH_MAX) + return -ENAMETOOLONG; + + symlink_target = kstrdup(symname, GFP_KERNEL); + if (!symlink_target) { + rc = -ENOMEM; + goto out; + } data = (struct cifs_open_info_data) { .reparse_point = true, .reparse = { .tag = IO_REPARSE_TAG_SYMLINK, }, - .symlink_target = sym, + .symlink_target = symlink_target, }; - convert_delimiter(sym, sep); + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) && + symroot && symname[0] == '/') { + /* + * This is a request to create an absolute symlink on the server + * which does not support POSIX paths, and expects symlink in + * NT-style path. So convert absolute Linux symlink target path + * to the absolute NT-style path. Root of the NT-style path for + * symlinks is specified in "symlinkroot" mount option. This will + * ensure compatibility of this symlink stored in absolute form + * on the SMB server. + */ + if (!strstarts(symname, symroot)) { + /* + * If the absolute Linux symlink target path is not + * inside "symlinkroot" location then there is no way + * to convert such Linux symlink to NT-style path. + */ + cifs_dbg(VFS, + "absolute symlink '%s' cannot be converted to NT format " + "because it is outside of symlinkroot='%s'\n", + symname, symroot); + rc = -EINVAL; + goto out; + } + len = strlen(symroot); + if (symroot[len - 1] != '/') + len++; + if (symname[len] >= 'a' && symname[len] <= 'z' && + (symname[len+1] == '/' || symname[len+1] == '\0')) { + /* + * Symlink points to Linux target /symlinkroot/x/path/... + * where 'x' is the lowercase local Windows drive. + * NT-style path for 'x' has common form \??\X:\path\... + * with uppercase local Windows drive. + */ + int common_path_len = strlen(symname+len+1)+1; + sym = kzalloc(6+common_path_len, GFP_KERNEL); + if (!sym) { + rc = -ENOMEM; + goto out; + } + memcpy(sym, "\\??\\", 4); + sym[4] = symname[len] - ('a'-'A'); + sym[5] = ':'; + memcpy(sym+6, symname+len+1, common_path_len); + } else { + /* Unhandled absolute symlink. Report an error. */ + cifs_dbg( + VFS, + "absolute symlink '%s' cannot be converted to NT format " + "because it points to unknown target\n", + symname); + rc = -EINVAL; + goto out; + } + } else { + /* + * This is request to either create an absolute symlink on + * server which expects POSIX paths or it is an request to + * create a relative symlink from the current directory. + * These paths have same format as relative SMB symlinks, + * so no conversion is needed. So just take symname as-is. + */ + sym = kstrdup(symname, GFP_KERNEL); + if (!sym) { + rc = -ENOMEM; + goto out; + } + } + + if (sep == '\\') + convert_delimiter(sym, sep); + + /* + * For absolute NT symlinks it is required to pass also leading + * backslash and to not mangle NT object prefix "\\??\\" and not to + * mangle colon in drive letter. But cifs_convert_path_to_utf16() + * removes leading backslash and replaces '?' and ':'. So temporary + * mask these characters in NT object prefix by '_' and then change + * them back. + */ + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) && symname[0] == '/') + sym[0] = sym[1] = sym[2] = sym[5] = '_'; + path = cifs_convert_path_to_utf16(sym, cifs_sb); if (!path) { rc = -ENOMEM; goto out; } - plen = 2 * UniStrnlen((wchar_t *)path, PATH_MAX); - len = sizeof(*buf) + plen * 2; + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) && symname[0] == '/') { + sym[0] = '\\'; + sym[1] = sym[2] = '?'; + sym[5] = ':'; + path[0] = cpu_to_le16('\\'); + path[1] = path[2] = cpu_to_le16('?'); + path[5] = cpu_to_le16(':'); + } + + /* + * SMB distinguish between symlink to directory and symlink to file. + * They cannot be exchanged (symlink of file type which points to + * directory cannot be resolved and vice-versa). Try to detect if + * the symlink target could be a directory or not. When detection + * fails then treat symlink as a file (non-directory) symlink. + */ + directory = false; + rc = detect_directory_symlink_target(cifs_sb, xid, full_path, symname, &directory); + if (rc < 0) + goto out; + + slen = 2 * UniStrnlen((wchar_t *)path, REPARSE_SYM_PATH_MAX); + poff = 0; + plen = slen; + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) && symname[0] == '/') { + /* + * For absolute NT symlinks skip leading "\\??\\" in PrintName as + * PrintName is user visible location in DOS/Win32 format (not in NT format). + */ + poff = 4; + plen -= 2 * poff; + } + len = sizeof(*buf) + plen + slen; buf = kzalloc(len, GFP_KERNEL); if (!buf) { rc = -ENOMEM; @@ -55,34 +214,205 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode, buf->ReparseTag = cpu_to_le32(IO_REPARSE_TAG_SYMLINK); buf->ReparseDataLength = cpu_to_le16(len - sizeof(struct reparse_data_buffer)); + buf->SubstituteNameOffset = cpu_to_le16(plen); - buf->SubstituteNameLength = cpu_to_le16(plen); - memcpy(&buf->PathBuffer[plen], path, plen); + buf->SubstituteNameLength = cpu_to_le16(slen); + memcpy(&buf->PathBuffer[plen], path, slen); + buf->PrintNameOffset = 0; buf->PrintNameLength = cpu_to_le16(plen); - memcpy(buf->PathBuffer, path, plen); + memcpy(buf->PathBuffer, path+poff, plen); + buf->Flags = cpu_to_le32(*symname != '/' ? SYMLINK_FLAG_RELATIVE : 0); - if (*sym != sep) - buf->Flags = cpu_to_le32(SYMLINK_FLAG_RELATIVE); - convert_delimiter(sym, '/'); iov.iov_base = buf; iov.iov_len = len; new = smb2_get_reparse_inode(&data, inode->i_sb, xid, - tcon, full_path, &iov, NULL); + tcon, full_path, directory, + &iov, NULL); if (!IS_ERR(new)) d_instantiate(dentry, new); else rc = PTR_ERR(new); out: + kfree(sym); kfree(path); cifs_free_open_info(&data); kfree(buf); return rc; } -static int nfs_set_reparse_buf(struct reparse_posix_data *buf, +static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb, + const unsigned int xid, + const char *full_path, + const char *symname, + bool *directory) +{ + char sep = CIFS_DIR_SEP(cifs_sb); + struct cifs_open_parms oparms; + struct tcon_link *tlink; + struct cifs_tcon *tcon; + const char *basename; + struct cifs_fid fid; + char *resolved_path; + int full_path_len; + int basename_len; + int symname_len; + char *path_sep; + __u32 oplock; + int open_rc; + + /* + * First do some simple check. If the original Linux symlink target ends + * with slash, or last path component is dot or dot-dot then it is for + * sure symlink to the directory. + */ + basename = kbasename(symname); + basename_len = strlen(basename); + if (basename_len == 0 || /* symname ends with slash */ + (basename_len == 1 && basename[0] == '.') || /* last component is "." */ + (basename_len == 2 && basename[0] == '.' && basename[1] == '.')) { /* or ".." */ + *directory = true; + return 0; + } + + /* + * For absolute symlinks it is not possible to determinate + * if it should point to directory or file. + */ + if (symname[0] == '/') { + cifs_dbg(FYI, + "%s: cannot determinate if the symlink target path '%s' " + "is directory or not, creating '%s' as file symlink\n", + __func__, symname, full_path); + return 0; + } + + /* + * If it was not detected as directory yet and the symlink is relative + * then try to resolve the path on the SMB server, check if the path + * exists and determinate if it is a directory or not. + */ + + full_path_len = strlen(full_path); + symname_len = strlen(symname); + + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) + return PTR_ERR(tlink); + + resolved_path = kzalloc(full_path_len + symname_len + 1, GFP_KERNEL); + if (!resolved_path) { + cifs_put_tlink(tlink); + return -ENOMEM; + } + + /* + * Compose the resolved SMB symlink path from the SMB full path + * and Linux target symlink path. + */ + memcpy(resolved_path, full_path, full_path_len+1); + path_sep = strrchr(resolved_path, sep); + if (path_sep) + path_sep++; + else + path_sep = resolved_path; + memcpy(path_sep, symname, symname_len+1); + if (sep == '\\') + convert_delimiter(path_sep, sep); + + tcon = tlink_tcon(tlink); + oparms = CIFS_OPARMS(cifs_sb, tcon, resolved_path, + FILE_READ_ATTRIBUTES, FILE_OPEN, 0, ACL_NO_MODE); + oparms.fid = &fid; + + /* Try to open as a directory (NOT_FILE) */ + oplock = 0; + oparms.create_options = cifs_create_options(cifs_sb, + CREATE_NOT_FILE | OPEN_REPARSE_POINT); + open_rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL); + if (open_rc == 0) { + /* Successful open means that the target path is definitely a directory. */ + *directory = true; + tcon->ses->server->ops->close(xid, tcon, &fid); + } else if (open_rc == -ENOTDIR) { + /* -ENOTDIR means that the target path is definitely a file. */ + *directory = false; + } else if (open_rc == -ENOENT) { + /* -ENOENT means that the target path does not exist. */ + cifs_dbg(FYI, + "%s: symlink target path '%s' does not exist, " + "creating '%s' as file symlink\n", + __func__, symname, full_path); + } else { + /* Try to open as a file (NOT_DIR) */ + oplock = 0; + oparms.create_options = cifs_create_options(cifs_sb, + CREATE_NOT_DIR | OPEN_REPARSE_POINT); + open_rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL); + if (open_rc == 0) { + /* Successful open means that the target path is definitely a file. */ + *directory = false; + tcon->ses->server->ops->close(xid, tcon, &fid); + } else if (open_rc == -EISDIR) { + /* -EISDIR means that the target path is definitely a directory. */ + *directory = true; + } else { + /* + * This code branch is called when we do not have a permission to + * open the resolved_path or some other client/process denied + * opening the resolved_path. + * + * TODO: Try to use ops->query_dir_first on the parent directory + * of resolved_path, search for basename of resolved_path and + * check if the ATTR_DIRECTORY is set in fi.Attributes. In some + * case this could work also when opening of the path is denied. + */ + cifs_dbg(FYI, + "%s: cannot determinate if the symlink target path '%s' " + "is directory or not, creating '%s' as file symlink\n", + __func__, symname, full_path); + } + } + + kfree(resolved_path); + cifs_put_tlink(tlink); + return 0; +} + +static int create_native_socket(const unsigned int xid, struct inode *inode, + struct dentry *dentry, struct cifs_tcon *tcon, + const char *full_path) +{ + struct reparse_data_buffer buf = { + .ReparseTag = cpu_to_le32(IO_REPARSE_TAG_AF_UNIX), + .ReparseDataLength = cpu_to_le16(0), + }; + struct cifs_open_info_data data = { + .reparse_point = true, + .reparse = { .tag = IO_REPARSE_TAG_AF_UNIX, .buf = &buf, }, + }; + struct kvec iov = { + .iov_base = &buf, + .iov_len = sizeof(buf), + }; + struct inode *new; + int rc = 0; + + new = smb2_get_reparse_inode(&data, inode->i_sb, xid, + tcon, full_path, false, &iov, NULL); + if (!IS_ERR(new)) + d_instantiate(dentry, new); + else + rc = PTR_ERR(new); + cifs_free_open_info(&data); + return rc; +} + +static int nfs_set_reparse_buf(struct reparse_nfs_data_buffer *buf, mode_t mode, dev_t dev, + __le16 *symname_utf16, + int symname_utf16_len, struct kvec *iov) { u64 type; @@ -93,7 +423,13 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf, switch ((type = reparse_mode_nfs_type(mode))) { case NFS_SPECFILE_BLK: case NFS_SPECFILE_CHR: - dlen = sizeof(__le64); + dlen = 2 * sizeof(__le32); + ((__le32 *)buf->DataBuffer)[0] = cpu_to_le32(MAJOR(dev)); + ((__le32 *)buf->DataBuffer)[1] = cpu_to_le32(MINOR(dev)); + break; + case NFS_SPECFILE_LNK: + dlen = symname_utf16_len; + memcpy(buf->DataBuffer, symname_utf16, symname_utf16_len); break; case NFS_SPECFILE_FIFO: case NFS_SPECFILE_SOCK: @@ -108,8 +444,6 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf, buf->InodeType = cpu_to_le64(type); buf->ReparseDataLength = cpu_to_le16(len + dlen - sizeof(struct reparse_data_buffer)); - *(__le64 *)buf->DataBuffer = cpu_to_le64(((u64)MAJOR(dev) << 32) | - MINOR(dev)); iov->iov_base = buf; iov->iov_len = len + dlen; return 0; @@ -117,38 +451,73 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf, static int mknod_nfs(unsigned int xid, struct inode *inode, struct dentry *dentry, struct cifs_tcon *tcon, - const char *full_path, umode_t mode, dev_t dev) + const char *full_path, umode_t mode, dev_t dev, + const char *symname) { + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); struct cifs_open_info_data data; - struct reparse_posix_data *p; + struct reparse_nfs_data_buffer *p = NULL; + __le16 *symname_utf16 = NULL; + int symname_utf16_len = 0; struct inode *new; struct kvec iov; __u8 buf[sizeof(*p) + sizeof(__le64)]; int rc; - p = (struct reparse_posix_data *)buf; - rc = nfs_set_reparse_buf(p, mode, dev, &iov); + if (S_ISLNK(mode)) { + symname_utf16 = cifs_strndup_to_utf16(symname, strlen(symname), + &symname_utf16_len, + cifs_sb->local_nls, + NO_MAP_UNI_RSVD); + if (!symname_utf16) { + rc = -ENOMEM; + goto out; + } + symname_utf16_len -= 2; /* symlink is without trailing wide-nul */ + p = kzalloc(sizeof(*p) + symname_utf16_len, GFP_KERNEL); + if (!p) { + rc = -ENOMEM; + goto out; + } + } else { + p = (struct reparse_nfs_data_buffer *)buf; + } + rc = nfs_set_reparse_buf(p, mode, dev, symname_utf16, symname_utf16_len, &iov); if (rc) - return rc; + goto out; data = (struct cifs_open_info_data) { .reparse_point = true, - .reparse = { .tag = IO_REPARSE_TAG_NFS, .posix = p, }, + .reparse = { .tag = IO_REPARSE_TAG_NFS, .buf = (struct reparse_data_buffer *)p, }, + .symlink_target = kstrdup(symname, GFP_KERNEL), }; new = smb2_get_reparse_inode(&data, inode->i_sb, xid, - tcon, full_path, &iov, NULL); + tcon, full_path, false, &iov, NULL); if (!IS_ERR(new)) d_instantiate(dentry, new); else rc = PTR_ERR(new); cifs_free_open_info(&data); +out: + if (S_ISLNK(mode)) { + kfree(symname_utf16); + kfree(p); + } return rc; } -static int wsl_set_reparse_buf(struct reparse_data_buffer *buf, - mode_t mode, struct kvec *iov) +static int wsl_set_reparse_buf(struct reparse_data_buffer **buf, + mode_t mode, const char *symname, + struct cifs_sb_info *cifs_sb, + struct kvec *iov) { + struct reparse_wsl_symlink_data_buffer *symlink_buf; + __le16 *symname_utf16; + int symname_utf16_len; + int symname_utf8_maxlen; + int symname_utf8_len; + size_t buf_len; u32 tag; switch ((tag = reparse_mode_wsl_tag(mode))) { @@ -156,16 +525,45 @@ static int wsl_set_reparse_buf(struct reparse_data_buffer *buf, case IO_REPARSE_TAG_LX_CHR: case IO_REPARSE_TAG_LX_FIFO: case IO_REPARSE_TAG_AF_UNIX: + buf_len = sizeof(struct reparse_data_buffer); + *buf = kzalloc(buf_len, GFP_KERNEL); + if (!*buf) + return -ENOMEM; + break; + case IO_REPARSE_TAG_LX_SYMLINK: + symname_utf16 = cifs_strndup_to_utf16(symname, strlen(symname), + &symname_utf16_len, + cifs_sb->local_nls, + NO_MAP_UNI_RSVD); + if (!symname_utf16) + return -ENOMEM; + symname_utf8_maxlen = symname_utf16_len/2*3; + symlink_buf = kzalloc(sizeof(struct reparse_wsl_symlink_data_buffer) + + symname_utf8_maxlen, GFP_KERNEL); + if (!symlink_buf) { + kfree(symname_utf16); + return -ENOMEM; + } + /* Version field must be set to 2 (MS-FSCC 2.1.2.7) */ + symlink_buf->Version = cpu_to_le32(2); + /* Target for Version 2 is in UTF-8 but without trailing null-term byte */ + symname_utf8_len = utf16s_to_utf8s((wchar_t *)symname_utf16, symname_utf16_len/2, + UTF16_LITTLE_ENDIAN, + symlink_buf->Target, + symname_utf8_maxlen); + *buf = (struct reparse_data_buffer *)symlink_buf; + buf_len = sizeof(struct reparse_wsl_symlink_data_buffer) + symname_utf8_len; + kfree(symname_utf16); break; default: return -EOPNOTSUPP; } - buf->ReparseTag = cpu_to_le32(tag); - buf->Reserved = 0; - buf->ReparseDataLength = 0; - iov->iov_base = buf; - iov->iov_len = sizeof(*buf); + (*buf)->ReparseTag = cpu_to_le32(tag); + (*buf)->Reserved = 0; + (*buf)->ReparseDataLength = cpu_to_le16(buf_len - sizeof(struct reparse_data_buffer)); + iov->iov_base = *buf; + iov->iov_len = buf_len; return 0; } @@ -217,8 +615,8 @@ static int wsl_set_xattrs(struct inode *inode, umode_t _mode, memset(iov, 0, sizeof(*iov)); - /* Exclude $LXDEV xattr for sockets and fifos */ - if (S_ISSOCK(_mode) || S_ISFIFO(_mode)) + /* Exclude $LXDEV xattr for non-device files */ + if (!S_ISBLK(_mode) && !S_ISCHR(_mode)) num_xattrs = ARRAY_SIZE(xattrs) - 1; else num_xattrs = ARRAY_SIZE(xattrs); @@ -254,27 +652,32 @@ static int wsl_set_xattrs(struct inode *inode, umode_t _mode, static int mknod_wsl(unsigned int xid, struct inode *inode, struct dentry *dentry, struct cifs_tcon *tcon, - const char *full_path, umode_t mode, dev_t dev) + const char *full_path, umode_t mode, dev_t dev, + const char *symname) { + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); struct cifs_open_info_data data; - struct reparse_data_buffer buf; + struct reparse_data_buffer *buf; struct smb2_create_ea_ctx *cc; struct inode *new; unsigned int len; struct kvec reparse_iov, xattr_iov; int rc; - rc = wsl_set_reparse_buf(&buf, mode, &reparse_iov); + rc = wsl_set_reparse_buf(&buf, mode, symname, cifs_sb, &reparse_iov); if (rc) return rc; rc = wsl_set_xattrs(inode, mode, dev, &xattr_iov); - if (rc) + if (rc) { + kfree(buf); return rc; + } data = (struct cifs_open_info_data) { .reparse_point = true, - .reparse = { .tag = le32_to_cpu(buf.ReparseTag), .buf = &buf, }, + .reparse = { .tag = le32_to_cpu(buf->ReparseTag), .buf = buf, }, + .symlink_target = kstrdup(symname, GFP_KERNEL), }; cc = xattr_iov.iov_base; @@ -283,7 +686,7 @@ static int mknod_wsl(unsigned int xid, struct inode *inode, data.wsl.eas_len = len; new = smb2_get_reparse_inode(&data, inode->i_sb, - xid, tcon, full_path, + xid, tcon, full_path, false, &reparse_iov, &xattr_iov); if (!IS_ERR(new)) d_instantiate(dentry, new); @@ -291,6 +694,7 @@ static int mknod_wsl(unsigned int xid, struct inode *inode, rc = PTR_ERR(new); cifs_free_open_info(&data); kfree(xattr_iov.iov_base); + kfree(buf); return rc; } @@ -299,43 +703,73 @@ int smb2_mknod_reparse(unsigned int xid, struct inode *inode, const char *full_path, umode_t mode, dev_t dev) { struct smb3_fs_context *ctx = CIFS_SB(inode->i_sb)->ctx; - int rc = -EOPNOTSUPP; + + if (S_ISSOCK(mode) && !ctx->nonativesocket && ctx->reparse_type != CIFS_REPARSE_TYPE_NONE) + return create_native_socket(xid, inode, dentry, tcon, full_path); switch (ctx->reparse_type) { case CIFS_REPARSE_TYPE_NFS: - rc = mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev); - break; + return mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev, NULL); case CIFS_REPARSE_TYPE_WSL: - rc = mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev); - break; + return mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev, NULL); + default: + return -EOPNOTSUPP; } - return rc; } /* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */ -static int parse_reparse_posix(struct reparse_posix_data *buf, +static int parse_reparse_nfs(struct reparse_nfs_data_buffer *buf, struct cifs_sb_info *cifs_sb, struct cifs_open_info_data *data) { unsigned int len; u64 type; + len = le16_to_cpu(buf->ReparseDataLength); + if (len < sizeof(buf->InodeType)) { + cifs_dbg(VFS, "srv returned malformed nfs buffer\n"); + return -EIO; + } + + len -= sizeof(buf->InodeType); + switch ((type = le64_to_cpu(buf->InodeType))) { case NFS_SPECFILE_LNK: - len = le16_to_cpu(buf->ReparseDataLength); + if (len == 0 || (len % 2)) { + cifs_dbg(VFS, "srv returned malformed nfs symlink buffer\n"); + return -EIO; + } + /* + * Check that buffer does not contain UTF-16 null codepoint + * because Linux cannot process symlink with null byte. + */ + if (UniStrnlen((wchar_t *)buf->DataBuffer, len/2) != len/2) { + cifs_dbg(VFS, "srv returned null byte in nfs symlink target location\n"); + return -EIO; + } data->symlink_target = cifs_strndup_from_utf16(buf->DataBuffer, len, true, cifs_sb->local_nls); if (!data->symlink_target) return -ENOMEM; - convert_delimiter(data->symlink_target, '/'); cifs_dbg(FYI, "%s: target path: %s\n", __func__, data->symlink_target); break; case NFS_SPECFILE_CHR: case NFS_SPECFILE_BLK: + /* DataBuffer for block and char devices contains two 32-bit numbers */ + if (len != 8) { + cifs_dbg(VFS, "srv returned malformed nfs buffer for type: 0x%llx\n", type); + return -EIO; + } + break; case NFS_SPECFILE_FIFO: case NFS_SPECFILE_SOCK: + /* DataBuffer for fifos and sockets is empty */ + if (len != 0) { + cifs_dbg(VFS, "srv returned malformed nfs buffer for type: 0x%llx\n", type); + return -EIO; + } break; default: cifs_dbg(VFS, "%s: unhandled inode type: 0x%llx\n", @@ -345,9 +779,208 @@ static int parse_reparse_posix(struct reparse_posix_data *buf, return 0; } -static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym, - u32 plen, bool unicode, +int smb2_parse_native_symlink(char **target, const char *buf, unsigned int len, + bool relative, + const char *full_path, + struct cifs_sb_info *cifs_sb) +{ + const char *symroot = cifs_sb->ctx->symlinkroot; + char sep = CIFS_DIR_SEP(cifs_sb); + char *linux_target = NULL; + char *smb_target = NULL; + int symlinkroot_len; + int abs_path_len; + char *abs_path; + int levels; + int rc; + int i; + + /* Check that length it valid */ + if (!len || (len % 2)) { + cifs_dbg(VFS, "srv returned malformed symlink buffer\n"); + rc = -EIO; + goto out; + } + + /* + * Check that buffer does not contain UTF-16 null codepoint + * because Linux cannot process symlink with null byte. + */ + if (UniStrnlen((wchar_t *)buf, len/2) != len/2) { + cifs_dbg(VFS, "srv returned null byte in native symlink target location\n"); + rc = -EIO; + goto out; + } + + smb_target = cifs_strndup_from_utf16(buf, len, true, cifs_sb->local_nls); + if (!smb_target) { + rc = -ENOMEM; + goto out; + } + + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) && + symroot && !relative) { + /* + * This is an absolute symlink from the server which does not + * support POSIX paths, so the symlink is in NT-style path. + * So convert it to absolute Linux symlink target path. Root of + * the NT-style path for symlinks is specified in "symlinkroot" + * mount option. + * + * Root of the DOS and Win32 paths is at NT path \??\ + * It means that DOS/Win32 path C:\folder\file.txt is + * NT path \??\C:\folder\file.txt + * + * NT systems have some well-known object symlinks in their NT + * hierarchy, which is needed to take into account when resolving + * other symlinks. Most commonly used symlink paths are: + * \?? -> \GLOBAL?? + * \DosDevices -> \?? + * \GLOBAL??\GLOBALROOT -> \ + * \GLOBAL??\Global -> \GLOBAL?? + * \GLOBAL??\NUL -> \Device\Null + * \GLOBAL??\UNC -> \Device\Mup + * \GLOBAL??\PhysicalDrive0 -> \Device\Harddisk0\DR0 (for each harddisk) + * \GLOBAL??\A: -> \Device\Floppy0 (if A: is the first floppy) + * \GLOBAL??\C: -> \Device\HarddiskVolume1 (if C: is the first harddisk) + * \GLOBAL??\D: -> \Device\CdRom0 (if D: is first cdrom) + * \SystemRoot -> \Device\Harddisk0\Partition1\WINDOWS (or where is NT system installed) + * \Volume{...} -> \Device\HarddiskVolume1 (where ... is system generated guid) + * + * In most common cases, absolute NT symlinks points to path on + * DOS/Win32 drive letter, system-specific Volume or on UNC share. + * Here are few examples of commonly used absolute NT symlinks + * created by mklink.exe tool: + * \??\C:\folder\file.txt + * \??\\C:\folder\file.txt + * \??\UNC\server\share\file.txt + * \??\\UNC\server\share\file.txt + * \??\Volume{b75e2c83-0000-0000-0000-602f00000000}\folder\file.txt + * + * It means that the most common path prefix \??\ is also NT path + * symlink (to \GLOBAL??). It is less common that second path + * separator is double backslash, but it is valid. + * + * Volume guid is randomly generated by the target system and so + * only the target system knows the mapping between guid and the + * hardisk number. Over SMB it is not possible to resolve this + * mapping, therefore symlinks pointing to target location of + * volume guids are totally unusable over SMB. + * + * For now parse only symlink paths available for DOS and Win32. + * Those are paths with \??\ prefix or paths which points to \??\ + * via other NT symlink (\DosDevices\, \GLOBAL??\, ...). + */ + abs_path = smb_target; +globalroot: + if (strstarts(abs_path, "\\??\\")) + abs_path += sizeof("\\??\\")-1; + else if (strstarts(abs_path, "\\DosDevices\\")) + abs_path += sizeof("\\DosDevices\\")-1; + else if (strstarts(abs_path, "\\GLOBAL??\\")) + abs_path += sizeof("\\GLOBAL??\\")-1; + else + goto out_unhandled_target; + + /* Sometimes path separator after \?? is double backslash */ + if (abs_path[0] == '\\') + abs_path++; + + while (strstarts(abs_path, "Global\\")) + abs_path += sizeof("Global\\")-1; + + if (strstarts(abs_path, "GLOBALROOT\\")) { + /* Label globalroot requires path with leading '\\', so do not trim '\\' */ + abs_path += sizeof("GLOBALROOT")-1; + goto globalroot; + } + + /* For now parse only paths to drive letters */ + if (((abs_path[0] >= 'A' && abs_path[0] <= 'Z') || + (abs_path[0] >= 'a' && abs_path[0] <= 'z')) && + abs_path[1] == ':' && + (abs_path[2] == '\\' || abs_path[2] == '\0')) { + /* Convert drive letter to lowercase and drop colon */ + char drive_letter = abs_path[0]; + if (drive_letter >= 'A' && drive_letter <= 'Z') + drive_letter += 'a'-'A'; + abs_path++; + abs_path[0] = drive_letter; + } else { + goto out_unhandled_target; + } + + abs_path_len = strlen(abs_path)+1; + symlinkroot_len = strlen(symroot); + if (symroot[symlinkroot_len - 1] == '/') + symlinkroot_len--; + linux_target = kmalloc(symlinkroot_len + 1 + abs_path_len, GFP_KERNEL); + if (!linux_target) { + rc = -ENOMEM; + goto out; + } + memcpy(linux_target, symroot, symlinkroot_len); + linux_target[symlinkroot_len] = '/'; + memcpy(linux_target + symlinkroot_len + 1, abs_path, abs_path_len); + } else if (smb_target[0] == sep && relative) { + /* + * This is a relative SMB symlink from the top of the share, + * which is the top level directory of the Linux mount point. + * Linux does not support such relative symlinks, so convert + * it to the relative symlink from the current directory. + * full_path is the SMB path to the symlink (from which is + * extracted current directory) and smb_target is the SMB path + * where symlink points, therefore full_path must always be on + * the SMB share. + */ + int smb_target_len = strlen(smb_target)+1; + levels = 0; + for (i = 1; full_path[i]; i++) { /* i=1 to skip leading sep */ + if (full_path[i] == sep) + levels++; + } + linux_target = kmalloc(levels*3 + smb_target_len, GFP_KERNEL); + if (!linux_target) { + rc = -ENOMEM; + goto out; + } + for (i = 0; i < levels; i++) { + linux_target[i*3 + 0] = '.'; + linux_target[i*3 + 1] = '.'; + linux_target[i*3 + 2] = sep; + } + memcpy(linux_target + levels*3, smb_target+1, smb_target_len); /* +1 to skip leading sep */ + } else { + /* + * This is either an absolute symlink in POSIX-style format + * or relative SMB symlink from the current directory. + * These paths have same format as Linux symlinks, so no + * conversion is needed. + */ +out_unhandled_target: + linux_target = smb_target; + smb_target = NULL; + } + + if (sep == '\\') + convert_delimiter(linux_target, '/'); + + rc = 0; + *target = linux_target; + + cifs_dbg(FYI, "%s: symlink target: %s\n", __func__, *target); + +out: + if (rc != 0) + kfree(linux_target); + kfree(smb_target); + return rc; +} + +static int parse_reparse_native_symlink(struct reparse_symlink_data_buffer *sym, + u32 plen, struct cifs_sb_info *cifs_sb, + const char *full_path, struct cifs_open_info_data *data) { unsigned int len; @@ -362,64 +995,117 @@ static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym, return -EIO; } - data->symlink_target = cifs_strndup_from_utf16(sym->PathBuffer + offs, - len, unicode, + return smb2_parse_native_symlink(&data->symlink_target, + sym->PathBuffer + offs, + len, + le32_to_cpu(sym->Flags) & SYMLINK_FLAG_RELATIVE, + full_path, + cifs_sb); +} + +static int parse_reparse_wsl_symlink(struct reparse_wsl_symlink_data_buffer *buf, + struct cifs_sb_info *cifs_sb, + struct cifs_open_info_data *data) +{ + int len = le16_to_cpu(buf->ReparseDataLength); + int data_offset = offsetof(typeof(*buf), Target) - offsetof(typeof(*buf), Version); + int symname_utf8_len; + __le16 *symname_utf16; + int symname_utf16_len; + + if (len <= data_offset) { + cifs_dbg(VFS, "srv returned malformed wsl symlink buffer\n"); + return -EIO; + } + + /* MS-FSCC 2.1.2.7 defines layout of the Target field only for Version 2. */ + if (le32_to_cpu(buf->Version) != 2) { + cifs_dbg(VFS, "srv returned unsupported wsl symlink version %u\n", le32_to_cpu(buf->Version)); + return -EIO; + } + + /* Target for Version 2 is in UTF-8 but without trailing null-term byte */ + symname_utf8_len = len - data_offset; + /* + * Check that buffer does not contain null byte + * because Linux cannot process symlink with null byte. + */ + if (strnlen(buf->Target, symname_utf8_len) != symname_utf8_len) { + cifs_dbg(VFS, "srv returned null byte in wsl symlink target location\n"); + return -EIO; + } + symname_utf16 = kzalloc(symname_utf8_len * 2, GFP_KERNEL); + if (!symname_utf16) + return -ENOMEM; + symname_utf16_len = utf8s_to_utf16s(buf->Target, symname_utf8_len, + UTF16_LITTLE_ENDIAN, + (wchar_t *) symname_utf16, symname_utf8_len * 2); + if (symname_utf16_len < 0) { + kfree(symname_utf16); + return symname_utf16_len; + } + symname_utf16_len *= 2; /* utf8s_to_utf16s() returns number of u16 items, not byte length */ + + data->symlink_target = cifs_strndup_from_utf16((u8 *)symname_utf16, + symname_utf16_len, true, cifs_sb->local_nls); + kfree(symname_utf16); if (!data->symlink_target) return -ENOMEM; - convert_delimiter(data->symlink_target, '/'); - cifs_dbg(FYI, "%s: target path: %s\n", __func__, data->symlink_target); - return 0; } int parse_reparse_point(struct reparse_data_buffer *buf, u32 plen, struct cifs_sb_info *cifs_sb, - bool unicode, struct cifs_open_info_data *data) + const char *full_path, + struct cifs_open_info_data *data) { data->reparse.buf = buf; /* See MS-FSCC 2.1.2 */ switch (le32_to_cpu(buf->ReparseTag)) { case IO_REPARSE_TAG_NFS: - return parse_reparse_posix((struct reparse_posix_data *)buf, + return parse_reparse_nfs((struct reparse_nfs_data_buffer *)buf, cifs_sb, data); case IO_REPARSE_TAG_SYMLINK: - return parse_reparse_symlink( + return parse_reparse_native_symlink( (struct reparse_symlink_data_buffer *)buf, - plen, unicode, cifs_sb, data); + plen, cifs_sb, full_path, data); case IO_REPARSE_TAG_LX_SYMLINK: + return parse_reparse_wsl_symlink( + (struct reparse_wsl_symlink_data_buffer *)buf, + cifs_sb, data); case IO_REPARSE_TAG_AF_UNIX: case IO_REPARSE_TAG_LX_FIFO: case IO_REPARSE_TAG_LX_CHR: case IO_REPARSE_TAG_LX_BLK: + if (le16_to_cpu(buf->ReparseDataLength) != 0) { + cifs_dbg(VFS, "srv returned malformed buffer for reparse point: 0x%08x\n", + le32_to_cpu(buf->ReparseTag)); + return -EIO; + } return 0; default: - cifs_dbg(VFS, "%s: unhandled reparse tag: 0x%08x\n", - __func__, le32_to_cpu(buf->ReparseTag)); return -EOPNOTSUPP; } } -int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb, - struct kvec *rsp_iov, - struct cifs_open_info_data *data) +struct reparse_data_buffer *smb2_get_reparse_point_buffer(const struct kvec *rsp_iov, + u32 *plen) { - struct reparse_data_buffer *buf; struct smb2_ioctl_rsp *io = rsp_iov->iov_base; - u32 plen = le32_to_cpu(io->OutputCount); - - buf = (struct reparse_data_buffer *)((u8 *)io + - le32_to_cpu(io->OutputOffset)); - return parse_reparse_point(buf, plen, cifs_sb, true, data); + *plen = le32_to_cpu(io->OutputCount); + return (struct reparse_data_buffer *)((u8 *)io + + le32_to_cpu(io->OutputOffset)); } -static void wsl_to_fattr(struct cifs_open_info_data *data, +static bool wsl_to_fattr(struct cifs_open_info_data *data, struct cifs_sb_info *cifs_sb, u32 tag, struct cifs_fattr *fattr) { struct smb2_file_full_ea_info *ea; + bool have_xattr_dev = false; u32 next = 0; switch (tag) { @@ -462,71 +1148,109 @@ static void wsl_to_fattr(struct cifs_open_info_data *data, fattr->cf_uid = wsl_make_kuid(cifs_sb, v); else if (!strncmp(name, SMB2_WSL_XATTR_GID, nlen)) fattr->cf_gid = wsl_make_kgid(cifs_sb, v); - else if (!strncmp(name, SMB2_WSL_XATTR_MODE, nlen)) + else if (!strncmp(name, SMB2_WSL_XATTR_MODE, nlen)) { + /* File type in reparse point tag and in xattr mode must match. */ + if (S_DT(fattr->cf_mode) != S_DT(le32_to_cpu(*(__le32 *)v))) + return false; fattr->cf_mode = (umode_t)le32_to_cpu(*(__le32 *)v); - else if (!strncmp(name, SMB2_WSL_XATTR_DEV, nlen)) - fattr->cf_rdev = wsl_mkdev(v); + } else if (!strncmp(name, SMB2_WSL_XATTR_DEV, nlen)) { + fattr->cf_rdev = reparse_mkdev(v); + have_xattr_dev = true; + } } while (next); out: - fattr->cf_dtype = S_DT(fattr->cf_mode); + + /* Major and minor numbers for char and block devices are mandatory. */ + if (!have_xattr_dev && (tag == IO_REPARSE_TAG_LX_CHR || tag == IO_REPARSE_TAG_LX_BLK)) + return false; + + return true; } -bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb, - struct cifs_fattr *fattr, - struct cifs_open_info_data *data) +static bool posix_reparse_to_fattr(struct cifs_sb_info *cifs_sb, + struct cifs_fattr *fattr, + struct cifs_open_info_data *data) { - struct reparse_posix_data *buf = data->reparse.posix; - u32 tag = data->reparse.tag; + struct reparse_nfs_data_buffer *buf = (struct reparse_nfs_data_buffer *)data->reparse.buf; - if (tag == IO_REPARSE_TAG_NFS && buf) { - switch (le64_to_cpu(buf->InodeType)) { - case NFS_SPECFILE_CHR: - fattr->cf_mode |= S_IFCHR; - fattr->cf_rdev = reparse_nfs_mkdev(buf); - break; - case NFS_SPECFILE_BLK: - fattr->cf_mode |= S_IFBLK; - fattr->cf_rdev = reparse_nfs_mkdev(buf); - break; - case NFS_SPECFILE_FIFO: - fattr->cf_mode |= S_IFIFO; - break; - case NFS_SPECFILE_SOCK: - fattr->cf_mode |= S_IFSOCK; - break; - case NFS_SPECFILE_LNK: - fattr->cf_mode |= S_IFLNK; - break; - default: + if (buf == NULL) + return true; + + if (le16_to_cpu(buf->ReparseDataLength) < sizeof(buf->InodeType)) { + WARN_ON_ONCE(1); + return false; + } + + switch (le64_to_cpu(buf->InodeType)) { + case NFS_SPECFILE_CHR: + if (le16_to_cpu(buf->ReparseDataLength) != sizeof(buf->InodeType) + 8) { WARN_ON_ONCE(1); return false; } - goto out; + fattr->cf_mode |= S_IFCHR; + fattr->cf_rdev = reparse_mkdev(buf->DataBuffer); + break; + case NFS_SPECFILE_BLK: + if (le16_to_cpu(buf->ReparseDataLength) != sizeof(buf->InodeType) + 8) { + WARN_ON_ONCE(1); + return false; + } + fattr->cf_mode |= S_IFBLK; + fattr->cf_rdev = reparse_mkdev(buf->DataBuffer); + break; + case NFS_SPECFILE_FIFO: + fattr->cf_mode |= S_IFIFO; + break; + case NFS_SPECFILE_SOCK: + fattr->cf_mode |= S_IFSOCK; + break; + case NFS_SPECFILE_LNK: + fattr->cf_mode |= S_IFLNK; + break; + default: + WARN_ON_ONCE(1); + return false; } + return true; +} + +bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb, + struct cifs_fattr *fattr, + struct cifs_open_info_data *data) +{ + u32 tag = data->reparse.tag; + bool ok; switch (tag) { - case IO_REPARSE_TAG_DFS: - case IO_REPARSE_TAG_DFSR: - case IO_REPARSE_TAG_MOUNT_POINT: - /* See cifs_create_junction_fattr() */ - fattr->cf_mode = S_IFDIR | 0711; - break; case IO_REPARSE_TAG_LX_SYMLINK: case IO_REPARSE_TAG_LX_FIFO: case IO_REPARSE_TAG_AF_UNIX: case IO_REPARSE_TAG_LX_CHR: case IO_REPARSE_TAG_LX_BLK: - wsl_to_fattr(data, cifs_sb, tag, fattr); + ok = wsl_to_fattr(data, cifs_sb, tag, fattr); + if (!ok) + return false; + break; + case IO_REPARSE_TAG_NFS: + ok = posix_reparse_to_fattr(cifs_sb, fattr, data); + if (!ok) + return false; break; case 0: /* SMB1 symlink */ case IO_REPARSE_TAG_SYMLINK: - case IO_REPARSE_TAG_NFS: fattr->cf_mode |= S_IFLNK; break; default: - return false; + if (!(fattr->cf_cifsattrs & ATTR_DIRECTORY)) + return false; + if (!IS_REPARSE_TAG_NAME_SURROGATE(tag) && + tag != IO_REPARSE_TAG_INTERNAL) + return false; + /* See cifs_create_junction_fattr() */ + fattr->cf_mode = S_IFDIR | 0711; + break; } -out: + fattr->cf_dtype = S_DT(fattr->cf_mode); return true; } |