/* * Store Windows ACLs in xattrs. * * Copyright (C) Volker Lendecke, 2008 * Copyright (C) Jeremy Allison, 2008 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . */ /* NOTE: This is an experimental module, not yet finished. JRA. */ #include "includes.h" #include "librpc/gen_ndr/xattr.h" #include "librpc/gen_ndr/ndr_xattr.h" #undef DBGC_CLASS #define DBGC_CLASS DBGC_VFS /******************************************************************* Parse out a struct security_descriptor from a DATA_BLOB. *******************************************************************/ static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob, uint32 security_info, struct security_descriptor **ppdesc) { TALLOC_CTX *ctx = talloc_tos(); struct xattr_NTACL xacl; enum ndr_err_code ndr_err; size_t sd_size; ndr_err = ndr_pull_struct_blob(pblob, ctx, NULL, &xacl, (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DEBUG(5, ("parse_acl_blob: ndr_pull_xattr_NTACL failed: %s\n", ndr_errstr(ndr_err))); return ndr_map_error2ntstatus(ndr_err);; } if (xacl.version != 2) { return NT_STATUS_REVISION_MISMATCH; } *ppdesc = make_sec_desc(ctx, SEC_DESC_REVISION, xacl.info.sd_hs->sd->type | SEC_DESC_SELF_RELATIVE, (security_info & OWNER_SECURITY_INFORMATION) ? xacl.info.sd_hs->sd->owner_sid : NULL, (security_info & GROUP_SECURITY_INFORMATION) ? xacl.info.sd_hs->sd->group_sid : NULL, (security_info & SACL_SECURITY_INFORMATION) ? xacl.info.sd_hs->sd->sacl : NULL, (security_info & DACL_SECURITY_INFORMATION) ? xacl.info.sd_hs->sd->dacl : NULL, &sd_size); TALLOC_FREE(xacl.info.sd); return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY; } /******************************************************************* Pull a security descriptor into a DATA_BLOB from a xattr. *******************************************************************/ static NTSTATUS get_acl_blob(TALLOC_CTX *ctx, vfs_handle_struct *handle, files_struct *fsp, const char *name, DATA_BLOB *pblob) { size_t size = 1024; uint8_t *val = NULL; uint8_t *tmp; ssize_t sizeret; int saved_errno = 0; ZERO_STRUCTP(pblob); again: tmp = TALLOC_REALLOC_ARRAY(ctx, val, uint8_t, size); if (tmp == NULL) { TALLOC_FREE(val); return NT_STATUS_NO_MEMORY; } val = tmp; become_root(); if (fsp && fsp->fh->fd != -1) { sizeret = SMB_VFS_FGETXATTR(fsp, XATTR_NTACL_NAME, val, size); } else { sizeret = SMB_VFS_GETXATTR(handle->conn, name, XATTR_NTACL_NAME, val, size); } if (sizeret == -1) { saved_errno = errno; } unbecome_root(); /* Max ACL size is 65536 bytes. */ if (sizeret == -1) { errno = saved_errno; if ((errno == ERANGE) && (size != 65536)) { /* Too small, try again. */ size = 65536; goto again; } /* Real error - exit here. */ TALLOC_FREE(val); return map_nt_error_from_unix(errno); } pblob->data = val; pblob->length = sizeret; return NT_STATUS_OK; } /******************************************************************* Create a DATA_BLOB from a security descriptor. *******************************************************************/ static NTSTATUS create_acl_blob(const struct security_descriptor *psd, DATA_BLOB *pblob) { struct xattr_NTACL xacl; struct security_descriptor_hash sd_hs; enum ndr_err_code ndr_err; TALLOC_CTX *ctx = talloc_tos(); ZERO_STRUCT(xacl); ZERO_STRUCT(sd_hs); xacl.version = 2; xacl.info.sd_hs = &sd_hs; xacl.info.sd_hs->sd = CONST_DISCARD(struct security_descriptor *, psd); memset(&xacl.info.sd_hs->hash[0], '\0', 16); ndr_err = ndr_push_struct_blob( pblob, ctx, NULL, &xacl, (ndr_push_flags_fn_t)ndr_push_xattr_NTACL); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DEBUG(5, ("create_acl_blob: ndr_push_xattr_NTACL failed: %s\n", ndr_errstr(ndr_err))); return ndr_map_error2ntstatus(ndr_err);; } return NT_STATUS_OK; } /******************************************************************* Store a DATA_BLOB into an xattr given an fsp pointer. *******************************************************************/ static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle, files_struct *fsp, DATA_BLOB *pblob) { int ret; int saved_errno = 0; DEBUG(10,("store_acl_blob_fsp: storing blob length %u on file %s\n", (unsigned int)pblob->length, fsp->fsp_name)); become_root(); if (fsp->fh->fd != -1) { ret = SMB_VFS_FSETXATTR(fsp, XATTR_NTACL_NAME, pblob->data, pblob->length, 0); } else { ret = SMB_VFS_SETXATTR(fsp->conn, fsp->fsp_name, XATTR_NTACL_NAME, pblob->data, pblob->length, 0); } if (ret) { saved_errno = errno; } unbecome_root(); if (ret) { errno = saved_errno; DEBUG(5, ("store_acl_blob_fsp: setting attr failed for file %s" "with error %s\n", fsp->fsp_name, strerror(errno) )); return map_nt_error_from_unix(errno); } return NT_STATUS_OK; } /******************************************************************* Store a DATA_BLOB into an xattr given a pathname. *******************************************************************/ static NTSTATUS store_acl_blob_pathname(vfs_handle_struct *handle, const char *fname, DATA_BLOB *pblob) { connection_struct *conn = handle->conn; int ret; int saved_errno = 0; DEBUG(10,("store_acl_blob_pathname: storing blob " "length %u on file %s\n", (unsigned int)pblob->length, fname)); become_root(); ret = SMB_VFS_SETXATTR(conn, fname, XATTR_NTACL_NAME, pblob->data, pblob->length, 0); if (ret) { saved_errno = errno; } unbecome_root(); if (ret) { errno = saved_errno; DEBUG(5, ("store_acl_blob_pathname: setting attr failed " "for file %s with error %s\n", fname, strerror(errno) )); return map_nt_error_from_unix(errno); } return NT_STATUS_OK; } /******************************************************************* Store a DATA_BLOB into an xattr given a pathname. *******************************************************************/ static NTSTATUS get_nt_acl_xattr_internal(vfs_handle_struct *handle, files_struct *fsp, const char *name, uint32 security_info, struct security_descriptor **ppdesc) { TALLOC_CTX *ctx = talloc_tos(); DATA_BLOB blob; NTSTATUS status; if (fsp && name == NULL) { name = fsp->fsp_name; } DEBUG(10, ("get_nt_acl_xattr_internal: name=%s\n", name)); status = get_acl_blob(ctx, handle, fsp, name, &blob); if (!NT_STATUS_IS_OK(status)) { DEBUG(10, ("get_acl_blob returned %s\n", nt_errstr(status))); return status; } status = parse_acl_blob(&blob, security_info, ppdesc); if (!NT_STATUS_IS_OK(status)) { DEBUG(10, ("parse_acl_blob returned %s\n", nt_errstr(status))); return status; } TALLOC_FREE(blob.data); return status; } /********************************************************************* Create a default security descriptor for a file in case no inheritance exists. All permissions to the owner and SYSTEM. *********************************************************************/ static struct security_descriptor *default_file_sd(TALLOC_CTX *mem_ctx, SMB_STRUCT_STAT *psbuf) { struct dom_sid owner_sid, group_sid; size_t sd_size; struct security_ace *pace = NULL; struct security_acl *pacl = NULL; uid_to_sid(&owner_sid, psbuf->st_uid); gid_to_sid(&group_sid, psbuf->st_gid); pace = TALLOC_ARRAY(mem_ctx, struct security_ace, 2); if (!pace) { return NULL; } init_sec_ace(&pace[0], &owner_sid, SEC_ACE_TYPE_ACCESS_ALLOWED, SEC_RIGHTS_FILE_ALL, 0); init_sec_ace(&pace[1], &global_sid_System, SEC_ACE_TYPE_ACCESS_ALLOWED, SEC_RIGHTS_FILE_ALL, 0); pacl = make_sec_acl(mem_ctx, NT4_ACL_REVISION, 2, pace); if (!pacl) { return NULL; } return make_sec_desc(mem_ctx, SECURITY_DESCRIPTOR_REVISION_1, SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT, &owner_sid, &group_sid, NULL, pacl, &sd_size); } /********************************************************************* *********************************************************************/ static NTSTATUS inherit_new_acl(vfs_handle_struct *handle, const char *fname, files_struct *fsp, bool container) { TALLOC_CTX *ctx = talloc_tos(); NTSTATUS status; struct security_descriptor *parent_desc = NULL; struct security_descriptor *psd = NULL; DATA_BLOB blob; size_t size; char *parent_name; if (!parent_dirname_talloc(ctx, fname, &parent_name, NULL)) { return NT_STATUS_NO_MEMORY; } DEBUG(10,("inherit_new_acl: check directory %s\n", parent_name)); status = get_nt_acl_xattr_internal(handle, NULL, parent_name, (OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION | DACL_SECURITY_INFORMATION), &parent_desc); if (NT_STATUS_IS_OK(status)) { /* Create an inherited descriptor from the parent. */ if (DEBUGLEVEL >= 10) { DEBUG(10,("inherit_new_acl: parent acl is:\n")); NDR_PRINT_DEBUG(security_descriptor, parent_desc); } status = se_create_child_secdesc(ctx, &psd, &size, parent_desc, &handle->conn->server_info->ptok->user_sids[PRIMARY_USER_SID_INDEX], &handle->conn->server_info->ptok->user_sids[PRIMARY_GROUP_SID_INDEX], container); if (!NT_STATUS_IS_OK(status)) { return status; } if (DEBUGLEVEL >= 10) { DEBUG(10,("inherit_new_acl: child acl is:\n")); NDR_PRINT_DEBUG(security_descriptor, psd); } } else { DEBUG(10,("inherit_new_acl: directory %s failed " "to get acl %s\n", parent_name, nt_errstr(status) )); } if (!psd || psd->dacl == NULL) { SMB_STRUCT_STAT sbuf; int ret; TALLOC_FREE(psd); if (fsp && !fsp->is_directory && fsp->fh->fd != -1) { ret = SMB_VFS_FSTAT(fsp, &sbuf); } else { ret = SMB_VFS_STAT(handle->conn,fname, &sbuf); } if (ret == -1) { return map_nt_error_from_unix(errno); } psd = default_file_sd(ctx, &sbuf); if (!psd) { return NT_STATUS_NO_MEMORY; } if (DEBUGLEVEL >= 10) { DEBUG(10,("inherit_new_acl: default acl is:\n")); NDR_PRINT_DEBUG(security_descriptor, psd); } } status = create_acl_blob(psd, &blob); if (!NT_STATUS_IS_OK(status)) { return status; } if (fsp) { return store_acl_blob_fsp(handle, fsp, &blob); } else { return store_acl_blob_pathname(handle, fname, &blob); } } /********************************************************************* Check ACL on open. For new files inherit from parent directory. *********************************************************************/ static int open_acl_xattr(vfs_handle_struct *handle, const char *fname, files_struct *fsp, int flags, mode_t mode) { uint32_t access_granted = 0; struct security_descriptor *pdesc = NULL; bool file_existed = true; NTSTATUS status = get_nt_acl_xattr_internal(handle, NULL, fname, (OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION | DACL_SECURITY_INFORMATION), &pdesc); if (NT_STATUS_IS_OK(status)) { /* See if we can access it. */ status = smb1_file_se_access_check(pdesc, handle->conn->server_info->ptok, fsp->access_mask, &access_granted); if (!NT_STATUS_IS_OK(status)) { DEBUG(10,("open_acl_xattr: file %s open " "refused with error %s\n", fname, nt_errstr(status) )); errno = map_errno_from_nt_status(status); return -1; } } else if (NT_STATUS_EQUAL(status,NT_STATUS_OBJECT_NAME_NOT_FOUND)) { file_existed = false; } DEBUG(10,("open_acl_xattr: get_nt_acl_attr_internal for " "file %s returned %s\n", fname, nt_errstr(status) )); fsp->fh->fd = SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode); if (!file_existed && fsp->fh->fd != -1) { /* File was created. Inherit from parent directory. */ string_set(&fsp->fsp_name, fname); inherit_new_acl(handle, fname, fsp, false); } return fsp->fh->fd; } static int mkdir_acl_xattr(vfs_handle_struct *handle, const char *path, mode_t mode) { int ret = SMB_VFS_NEXT_MKDIR(handle, path, mode); if (ret == -1) { return ret; } /* New directory - inherit from parent. */ inherit_new_acl(handle, path, NULL, true); return ret; } /********************************************************************* Fetch a security descriptor given an fsp. *********************************************************************/ static NTSTATUS fget_nt_acl_xattr(vfs_handle_struct *handle, files_struct *fsp, uint32 security_info, struct security_descriptor **ppdesc) { NTSTATUS status = get_nt_acl_xattr_internal(handle, fsp, NULL, security_info, ppdesc); if (NT_STATUS_IS_OK(status)) { if (DEBUGLEVEL >= 10) { DEBUG(10,("fget_nt_acl_xattr: returning xattr sd for file %s\n", fsp->fsp_name)); NDR_PRINT_DEBUG(security_descriptor, *ppdesc); } return NT_STATUS_OK; } DEBUG(10,("fget_nt_acl_xattr: failed to get xattr sd for file %s, Error %s\n", fsp->fsp_name, nt_errstr(status) )); return SMB_VFS_NEXT_FGET_NT_ACL(handle, fsp, security_info, ppdesc); } /********************************************************************* Fetch a security descriptor given a pathname. *********************************************************************/ static NTSTATUS get_nt_acl_xattr(vfs_handle_struct *handle, const char *name, uint32 security_info, struct security_descriptor **ppdesc) { NTSTATUS status = get_nt_acl_xattr_internal(handle, NULL, name, security_info, ppdesc); if (NT_STATUS_IS_OK(status)) { if (DEBUGLEVEL >= 10) { DEBUG(10,("get_nt_acl_xattr: returning xattr sd for file %s\n", name)); NDR_PRINT_DEBUG(security_descriptor, *ppdesc); } return NT_STATUS_OK; } DEBUG(10,("get_nt_acl_xattr: failed to get xattr sd for file %s, Error %s\n", name, nt_errstr(status) )); return SMB_VFS_NEXT_GET_NT_ACL(handle, name, security_info, ppdesc); } /********************************************************************* Store a security descriptor given an fsp. *********************************************************************/ static NTSTATUS fset_nt_acl_xattr(vfs_handle_struct *handle, files_struct *fsp, uint32 security_info_sent, const struct security_descriptor *psd) { NTSTATUS status; DATA_BLOB blob; if (DEBUGLEVEL >= 10) { DEBUG(10,("fset_nt_acl_xattr: incoming sd for file %s\n", fsp->fsp_name)); NDR_PRINT_DEBUG(security_descriptor, CONST_DISCARD(struct security_descriptor *,psd)); } status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd); if (!NT_STATUS_IS_OK(status)) { return status; } /* Ensure owner and group are set. */ if (!psd->owner_sid || !psd->group_sid) { int ret; SMB_STRUCT_STAT sbuf; DOM_SID owner_sid, group_sid; struct security_descriptor *nc_psd = dup_sec_desc(talloc_tos(), psd); if (!nc_psd) { return NT_STATUS_OK; } if (fsp->is_directory || fsp->fh->fd == -1) { ret = SMB_VFS_STAT(fsp->conn,fsp->fsp_name, &sbuf); } else { ret = SMB_VFS_FSTAT(fsp, &sbuf); } if (ret == -1) { /* Lower level acl set succeeded, * so still return OK. */ return NT_STATUS_OK; } create_file_sids(&sbuf, &owner_sid, &group_sid); /* This is safe as nc_psd is discarded at fn exit. */ nc_psd->owner_sid = &owner_sid; nc_psd->group_sid = &group_sid; security_info_sent |= (OWNER_SECURITY_INFORMATION|GROUP_SECURITY_INFORMATION); psd = nc_psd; } if ((security_info_sent & DACL_SECURITY_INFORMATION) && psd->dacl != NULL && (psd->type & (SE_DESC_DACL_AUTO_INHERITED| SE_DESC_DACL_AUTO_INHERIT_REQ))== (SE_DESC_DACL_AUTO_INHERITED| SE_DESC_DACL_AUTO_INHERIT_REQ) ) { struct security_descriptor *new_psd = NULL; status = append_parent_acl(fsp, psd, &new_psd); if (!NT_STATUS_IS_OK(status)) { /* Lower level acl set succeeded, * so still return OK. */ return NT_STATUS_OK; } psd = new_psd; } if (DEBUGLEVEL >= 10) { DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n", fsp->fsp_name)); NDR_PRINT_DEBUG(security_descriptor, CONST_DISCARD(struct security_descriptor *,psd)); } create_acl_blob(psd, &blob); store_acl_blob_fsp(handle, fsp, &blob); return NT_STATUS_OK; } /********************************************************************* Remove a Windows ACL - we're setting the underlying POSIX ACL. *********************************************************************/ static int sys_acl_set_file_xattr(vfs_handle_struct *handle, const char *name, SMB_ACL_TYPE_T type, SMB_ACL_T theacl) { int ret = SMB_VFS_NEXT_SYS_ACL_SET_FILE(handle, name, type, theacl); if (ret == -1) { return -1; } become_root(); SMB_VFS_REMOVEXATTR(handle, name, XATTR_NTACL_NAME); unbecome_root(); return ret; } /********************************************************************* Remove a Windows ACL - we're setting the underlying POSIX ACL. *********************************************************************/ static int sys_acl_set_fd_xattr(vfs_handle_struct *handle, files_struct *fsp, SMB_ACL_T theacl) { int ret = SMB_VFS_NEXT_SYS_ACL_SET_FD(handle, fsp, theacl); if (ret == -1) { return -1; } become_root(); SMB_VFS_FREMOVEXATTR(handle, fsp, XATTR_NTACL_NAME); unbecome_root(); return ret; } /********************************************************************* Remove a Windows ACL - we're setting the underlying POSIX ACL. *********************************************************************/ static int sys_acl_set_file_xattr(vfs_handle_struct *handle, const char *name, SMB_ACL_TYPE_T type, SMB_ACL_T theacl) { int ret = SMB_VFS_NEXT_SYS_ACL_SET_FILE(handle, name, type, theacl); if (ret == -1) { return -1; } become_root(); SMB_VFS_REMOVEXATTR(handle->conn, name, XATTR_NTACL_NAME); unbecome_root(); return ret; } /********************************************************************* Remove a Windows ACL - we're setting the underlying POSIX ACL. *********************************************************************/ static int sys_acl_set_fd_xattr(vfs_handle_struct *handle, files_struct *fsp, SMB_ACL_T theacl) { int ret = SMB_VFS_NEXT_SYS_ACL_SET_FD(handle, fsp, theacl); if (ret == -1) { return -1; } become_root(); SMB_VFS_FREMOVEXATTR(fsp, XATTR_NTACL_NAME); unbecome_root(); return ret; } /* VFS operations structure */ static vfs_op_tuple skel_op_tuples[] = { {SMB_VFS_OP(mkdir_acl_xattr), SMB_VFS_OP_MKDIR, SMB_VFS_LAYER_TRANSPARENT}, {SMB_VFS_OP(open_acl_xattr), SMB_VFS_OP_OPEN, SMB_VFS_LAYER_TRANSPARENT}, /* NT File ACL operations */ {SMB_VFS_OP(fget_nt_acl_xattr),SMB_VFS_OP_FGET_NT_ACL,SMB_VFS_LAYER_TRANSPARENT}, {SMB_VFS_OP(get_nt_acl_xattr), SMB_VFS_OP_GET_NT_ACL, SMB_VFS_LAYER_TRANSPARENT}, {SMB_VFS_OP(fset_nt_acl_xattr),SMB_VFS_OP_FSET_NT_ACL,SMB_VFS_LAYER_TRANSPARENT}, /* POSIX ACL operations. */ {SMB_VFS_OP(sys_acl_set_file_xattr), SMB_VFS_OP_SYS_ACL_SET_FILE, SMB_VFS_LAYER_TRANSPARENT}, {SMB_VFS_OP(sys_acl_set_fd_xattr), SMB_VFS_OP_SYS_ACL_SET_FD, SMB_VFS_LAYER_TRANSPARENT}, /* POSIX ACL operations. */ {SMB_VFS_OP(sys_acl_set_file_xattr), SMB_VFS_OP_SYS_ACL_SET_FILE, SMB_VFS_LAYER_TRANSPARENT}, {SMB_VFS_OP(sys_acl_set_fd_xattr), SMB_VFS_OP_SYS_ACL_SET_FD, SMB_VFS_LAYER_TRANSPARENT}, {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP} }; NTSTATUS vfs_acl_xattr_init(void) { return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "acl_xattr", skel_op_tuples); }