1 /* Core interface of secnet, to be used by all modules */
3 * This file is part of secnet.
4 * See README for full list of copyright holders.
6 * secnet is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version d of the License, or
9 * (at your option) any later version.
11 * secnet is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * version 3 along with secnet; if not, see
18 * https://www.gnu.org/licenses/gpl.html.
24 #define ADNS_FEATURE_MANYAF
37 #include <sys/types.h>
40 #include <netinet/in.h>
41 #include <arpa/inet.h>
43 #include <bsd/sys/queue.h>
45 #define MAX_PEER_ADDRS 5
46 /* send at most this many copies; honour at most that many addresses */
51 typedef char *string_t
;
52 typedef const char *cstring_t
;
54 #define False (_Bool)0
60 struct sockaddr_in sin
;
62 struct sockaddr_in6 sin6
;
66 #define ASSERT(x) do { if (!(x)) { fatal("assertion failed line %d file " \
67 __FILE__,__LINE__); } } while(0)
71 extern char version
[];
74 extern uint32_t message_level
;
75 extern bool_t secnet_is_daemon
;
76 extern struct log_if
*system_log
;
79 extern void start_signal_handling(void);
82 /* Must be called before exec in every child made after
83 start_signal_handling. Safe to call in earlier children too. */
85 void childpersist_closefd_hook(void *fd_p
, uint32_t newphase
);
86 /* Convenience hook function for use with add_hook PHASE_CHILDPERSIST.
87 With `int fd' in your state struct, pass fd_p=&fd. The hook checks
88 whether fd>=0, so you can use it for an fd which is only sometimes
89 open. This function will set fd to -1, so it is idempotent. */
91 /***** CONFIGURATION support *****/
93 extern bool_t just_check_config
; /* If True then we're going to exit after
94 reading the configuration file */
95 extern bool_t background
; /* If True then we'll eventually run as a daemon */
97 typedef struct dict dict_t
; /* Configuration dictionary */
98 typedef struct closure closure_t
;
99 typedef struct item item_t
;
100 typedef struct list list_t
; /* A list of items */
102 /* Configuration file location, for error-reporting */
108 /* Modules export closures, which can be invoked from the configuration file.
109 "Invoking" a closure usually returns another closure (of a different
110 type), but can actually return any configuration object. */
111 typedef list_t
*(apply_fn
)(closure_t
*self
, struct cloc loc
,
112 dict_t
*context
, list_t
*data
);
114 cstring_t description
; /* For debugging */
115 uint32_t type
; /* Central registry... */
117 void *interface
; /* Interface for use inside secnet; depends on type */
120 enum types
{ t_null
, t_bool
, t_string
, t_number
, t_dict
, t_closure
};
133 /* Note that it is unwise to use this structure directly; use the list
134 manipulation functions instead. */
140 /* In the following two lookup functions, NULL means 'not found' */
141 /* Lookup a value in the specified dictionary, or its parents */
142 extern list_t
*dict_lookup(dict_t
*dict
, cstring_t key
);
143 /* Lookup a value in just the specified dictionary */
144 extern list_t
*dict_lookup_primitive(dict_t
*dict
, cstring_t key
);
145 /* Add a value to the specified dictionary */
146 extern void dict_add(dict_t
*dict
, cstring_t key
, list_t
*val
);
147 /* Obtain an array of keys in the dictionary. malloced; caller frees */
148 extern cstring_t
*dict_keys(dict_t
*dict
);
150 /* List-manipulation functions */
151 extern list_t
*list_new(void);
152 extern int32_t list_length(const list_t
*a
);
153 extern list_t
*list_append(list_t
*a
, item_t
*i
);
154 extern list_t
*list_append_list(list_t
*a
, list_t
*b
);
155 /* Returns an item from the list (index starts at 0), or NULL */
156 extern item_t
*list_elem(list_t
*l
, int32_t index
);
158 /* Convenience functions */
159 extern list_t
*new_closure(closure_t
*cl
);
160 extern void add_closure(dict_t
*dict
, cstring_t name
, apply_fn apply
);
161 extern void *find_cl_if(dict_t
*dict
, cstring_t name
, uint32_t type
,
162 bool_t fail_if_invalid
, cstring_t desc
,
164 extern item_t
*dict_find_item(dict_t
*dict
, cstring_t key
, bool_t required
,
165 cstring_t desc
, struct cloc loc
);
166 extern string_t
dict_read_string(dict_t
*dict
, cstring_t key
, bool_t required
,
167 cstring_t desc
, struct cloc loc
);
168 extern uint32_t dict_read_number(dict_t
*dict
, cstring_t key
, bool_t required
,
169 cstring_t desc
, struct cloc loc
,
171 /* return value can safely be assigned to int32_t */
172 extern bool_t
dict_read_bool(dict_t
*dict
, cstring_t key
, bool_t required
,
173 cstring_t desc
, struct cloc loc
, bool_t def
);
174 const char **dict_read_string_array(dict_t
*dict
, cstring_t key
,
175 bool_t required
, cstring_t desc
,
176 struct cloc loc
, const char *const *def
);
177 /* Return value is a NULL-terminated array obtained from malloc;
178 * Individual string values are still owned by config file machinery
179 * and must not be modified or freed. Returns NULL if key not
186 extern uint32_t string_to_word(cstring_t s
, struct cloc loc
,
187 struct flagstr
*f
, cstring_t desc
);
188 extern uint32_t string_list_to_word(list_t
*l
, struct flagstr
*f
,
191 /***** END of configuration support *****/
193 /***** UTILITY functions *****/
195 extern char *safe_strdup(const char *string
, const char *message
);
196 extern void *safe_malloc(size_t size
, const char *message
);
197 extern void *safe_malloc_ary(size_t size
, size_t count
, const char *message
);
198 extern void *safe_realloc_ary(void *p
, size_t size
, size_t count
,
199 const char *message
);
202 ((p)=safe_malloc(sizeof(*(p)), \
204 #define NEW_ARY(p,count) \
205 ((p)=safe_malloc_ary(sizeof(*(p)),(count), \
206 __FILE__ ":" #p "[" #count "]"))
207 #define REALLOC_ARY(p,count) \
208 ((p)=safe_realloc_ary((p),sizeof(*(p)),(count), \
209 __FILE__ ":" #p "[" #count "]"))
211 void setcloexec(int fd
); /* cannot fail */
212 void setnonblock(int fd
); /* cannot fail */
213 void pipe_cloexec(int fd
[2]); /* pipe(), setcloexec() twice; cannot fail */
215 extern int sys_cmd(const char *file
, const char *argc
, ...);
217 extern uint64_t now_global
;
218 extern struct timeval tv_now_global
;
220 static const uint64_t *const now
= &now_global
;
221 static const struct timeval
*const tv_now
= &tv_now_global
;
223 /* "now" is current program time, in milliseconds. It is derived
224 from tv_now. Both are provided by the event loop. */
226 /***** END of utility functions *****/
228 /***** START of max_start_pad handling *****/
230 extern int32_t site_max_start_pad
, transform_max_start_pad
,
233 void update_max_start_pad(int32_t *our_module_global
, int32_t our_instance
);
234 int32_t calculate_max_start_pad(void);
236 /***** END of max_start_pad handling *****/
238 /***** SCHEDULING support */
240 /* If nfds_io is insufficient for your needs, set it to the required
241 number and return ERANGE. timeout is in milliseconds; if it is too
242 high then lower it. It starts at -1 (==infinite). */
243 /* Note that beforepoll_fn may NOT do anything which might change the
244 fds or timeouts wanted by other registered poll loop loopers.
245 Callers should make sure of this by not making any calls into other
246 modules from the beforepoll_fn; the easiest way to ensure this is
247 for beforepoll_fn to only retreive information and not take any
250 typedef int beforepoll_fn(void *st
, struct pollfd
*fds
, int *nfds_io
,
252 typedef void afterpoll_fn(void *st
, struct pollfd
*fds
, int nfds
);
253 /* If beforepoll_fn returned ERANGE, afterpoll_fn gets nfds==0.
254 afterpoll_fn never gets !!(fds[].revents & POLLNVAL) - such
255 a report is detected as a fatal error by the event loop. */
257 /* void BEFOREPOLL_WANT_FDS(int want);
258 * Expects: int *nfds_io;
259 * Can perform non-local exit.
260 * Checks whether there is space for want fds. If so, sets *nfds_io.
261 * If not, sets *nfds_io and returns. */
262 #define BEFOREPOLL_WANT_FDS(want) do{ \
263 if (*nfds_io<(want)) { *nfds_io=(want); return ERANGE; } \
267 /* Register interest in the main loop of the program. Before a call
268 to poll() your supplied beforepoll function will be called. After
269 the call to poll() the supplied afterpoll function will be called. */
270 struct poll_interest
*register_for_poll(void *st
, beforepoll_fn
*before
,
271 afterpoll_fn
*after
, cstring_t desc
);
272 void deregister_for_poll(struct poll_interest
*i
);
274 /***** END of scheduling support */
276 /***** PROGRAM LIFETIME support */
278 /* The secnet program goes through a number of phases in its lifetime.
279 Module code may arrange to be called just as various phases are
282 Remember to update the table in util.c if changing the set of
287 PHASE_GETOPTS
, /* Process command-line arguments */
288 PHASE_READCONFIG
, /* Parse and process configuration file */
289 PHASE_SETUP
, /* Process information in configuration */
290 PHASE_DAEMONIZE
, /* Become a daemon (if necessary) */
291 PHASE_GETRESOURCES
, /* Obtain all external resources */
292 PHASE_DROPPRIV
, /* Last chance for privileged operations */
294 PHASE_SHUTDOWN
, /* About to die; delete key material, etc. */
295 PHASE_CHILDPERSIST
, /* Forked long-term child: close fds, etc. */
296 /* Keep this last: */
300 /* Each module should, in its CHILDPERSIST hooks, close all fds which
301 constitute ownership of important operating system resources, or
302 which are used for IPC with other processes who want to get the
303 usual disconnection effects if the main secnet process dies.
304 CHILDPERSIST hooks are not run if the child is going to exec;
305 so fds such as described above should be CLOEXEC too. */
307 typedef void hook_fn(void *self
, uint32_t newphase
);
308 bool_t
add_hook(uint32_t phase
, hook_fn
*f
, void *state
);
309 bool_t
remove_hook(uint32_t phase
, hook_fn
*f
, void *state
);
311 extern uint32_t current_phase
;
312 extern void enter_phase(uint32_t new_phase
);
314 void phase_hooks_init(void); /* for main() only */
315 void clear_phase_hooks(uint32_t phase
); /* for afterfork() */
317 /* Some features (like netlink 'soft' routes) require that secnet
318 retain root privileges. They should indicate that here when
320 extern bool_t require_root_privileges
;
321 extern cstring_t require_root_privileges_explanation
;
323 /* Some modules may want to know whether secnet is going to drop
324 privilege, so that they know whether to do privsep. Call only
325 in phases SETUP and later. */
326 bool_t
will_droppriv(void);
328 /***** END of program lifetime support *****/
330 /***** MODULE support *****/
332 /* Module initialisation function type - modules export one function of
333 this type which is called to initialise them. For dynamically loaded
334 modules it's called "secnet_module". */
335 typedef void init_module(dict_t
*dict
);
337 extern void init_builtin_modules(dict_t
*dict
);
339 extern init_module resolver_module
;
340 extern init_module random_module
;
341 extern init_module udp_module
;
342 extern init_module polypath_module
;
343 extern init_module util_module
;
344 extern init_module site_module
;
345 extern init_module transform_eax_module
;
346 extern init_module transform_cbcmac_module
;
347 extern init_module netlink_module
;
348 extern init_module rsa_module
;
349 extern init_module dh_module
;
350 extern init_module md5_module
;
351 extern init_module slip_module
;
352 extern init_module tun_module
;
353 extern init_module sha1_module
;
354 extern init_module log_module
;
356 /***** END of module support *****/
358 /***** CLOSURE TYPES and interface definitions *****/
361 #define CL_RESOLVER 1
362 #define CL_RANDOMSRC 2
363 #define CL_RSAPUBKEY 3
364 #define CL_RSAPRIVKEY 4
369 #define CL_TRANSFORM 9
373 #define CL_NETLINK 14
377 /* PURE closure requires no interface */
379 /* RESOLVER interface */
381 /* Answers to queries are delivered to a function of this
382 type. 'address' will be NULL if there was a problem with the query. It
383 will be freed once resolve_answer_fn returns. naddrs is the actual
384 size of the array at addrs; was_naddrs is the number of addresses
385 actually found in the DNS, which may be bigger if addrs is equal
386 to MAX_PEER_ADDRS (ie there were too many). */
387 typedef void resolve_answer_fn(void *st
, const struct comm_addr
*addrs
,
388 int naddrs
, int was_naddrs
,
389 const char *name
, const char *failwhy
);
390 /* name is the same ptr as passed to request, so its lifetime must
392 typedef bool_t
resolve_request_fn(void *st
, cstring_t name
,
393 int remoteport
, struct comm_if
*comm
,
394 resolve_answer_fn
*cb
, void *cst
);
397 resolve_request_fn
*request
;
400 /* RANDOMSRC interface */
402 /* Return some random data. Returns TRUE for success. */
403 typedef bool_t
random_fn(void *st
, int32_t bytes
, uint8_t *buff
);
411 /* RSAPUBKEY interface */
413 typedef bool_t
rsa_checksig_fn(void *st
, uint8_t *data
, int32_t datalen
,
414 cstring_t signature
);
415 struct rsapubkey_if
{
417 rsa_checksig_fn
*check
;
420 /* RSAPRIVKEY interface */
422 typedef string_t
rsa_makesig_fn(void *st
, uint8_t *data
, int32_t datalen
);
423 struct rsaprivkey_if
{
425 rsa_makesig_fn
*sign
;
431 /* This struct is pure data; in particular comm's clients may
433 struct comm_if
*comm
;
435 int ix
; /* see comment `Re comm_addr.ix' in udp.c */
438 /* Return True if the packet was processed, and shouldn't be passed to
439 any other potential receivers. (buf is freed iff True returned.) */
440 typedef bool_t
comm_notify_fn(void *state
, struct buffer_if
*buf
,
441 const struct comm_addr
*source
);
442 typedef void comm_request_notify_fn(void *commst
, void *nst
,
444 typedef void comm_release_notify_fn(void *commst
, void *nst
,
446 typedef bool_t
comm_sendmsg_fn(void *commst
, struct buffer_if
*buf
,
447 const struct comm_addr
*dest
);
448 /* Only returns false if (we know that) the local network
449 * environment is such that this address cannot work; transient
450 * or unknown/unexpected failures return true. */
451 typedef const char *comm_addr_to_string_fn(void *commst
,
452 const struct comm_addr
*ca
);
453 /* Returned string is in a static buffer. */
456 comm_request_notify_fn
*request_notify
;
457 comm_release_notify_fn
*release_notify
;
458 comm_sendmsg_fn
*sendmsg
;
459 comm_addr_to_string_fn
*addr_to_string
;
462 bool_t
iaddr_equal(const union iaddr
*ia
, const union iaddr
*ib
,
465 static inline const char *comm_addr_to_string(const struct comm_addr
*ca
)
467 return ca
->comm
->addr_to_string(ca
->comm
->st
, ca
);
470 static inline bool_t
comm_addr_equal(const struct comm_addr
*a
,
471 const struct comm_addr
*b
)
473 return a
->comm
==b
->comm
&& iaddr_equal(&a
->ia
,&b
->ia
,False
);
478 #define LOG_MESSAGE_BUFLEN 1023
480 typedef void log_msg_fn(void *st
, int class, const char *message
, ...);
481 typedef void log_vmsg_fn(void *st
, int class, const char *message
,
485 log_vmsg_fn
*vlogfn
; /* printf format checking. Use [v]slilog instead */
486 char buff
[LOG_MESSAGE_BUFLEN
+1];
488 /* (convenience functions, defined in util.c) */
489 extern void slilog(struct log_if
*lf
, int class, const char *message
, ...)
491 extern void vslilog(struct log_if
*lf
, int class, const char *message
, va_list)
494 /* Versions which take (parts of) (multiple) messages, using \n to
495 * distinguish one message from another. */
496 extern void slilog_part(struct log_if
*lf
, int class, const char *message
, ...)
498 extern void vslilog_part(struct log_if
*lf
, int class, const char *message
,
499 va_list) FORMAT(printf
,3,0);
503 /* Pretty much a placeholder; allows starting and stopping of processing,
505 typedef void site_control_fn(void *st
, bool_t run
);
506 typedef uint32_t site_status_fn(void *st
);
509 site_control_fn
*control
;
510 site_status_fn
*status
;
513 /* TRANSFORM interface */
515 /* A reversable transformation. Transforms buffer in-place; may add
516 data to start or end. (Reverse transformations decrease
517 length, of course.) Transformations may be key-dependent, in which
518 case key material is passed in at initialisation time. They may
519 also depend on internal factors (eg. time) and keep internal
520 state. A struct transform_if only represents a particular type of
521 transformation; instances of the transformation (eg. with
522 particular key material) have a different C type. The same
523 secret key will be used in opposite directions between a pair of
524 secnets; one of these pairs will get direction==False, the other True. */
526 typedef struct transform_inst_if
*transform_createinstance_fn(void *st
);
527 typedef bool_t
transform_setkey_fn(void *st
, uint8_t *key
, int32_t keylen
,
529 typedef bool_t
transform_valid_fn(void *st
); /* 0: no key; 1: ok */
530 typedef void transform_delkey_fn(void *st
);
531 typedef void transform_destroyinstance_fn(void *st
);
534 * 1: for any other problem
535 * 2: message decrypted but sequence number was out of range
537 typedef uint32_t transform_apply_fn(void *st
, struct buffer_if
*buf
,
538 const char **errmsg
);
540 struct transform_inst_if
{
542 transform_setkey_fn
*setkey
;
543 transform_valid_fn
*valid
;
544 transform_delkey_fn
*delkey
;
545 transform_apply_fn
*forwards
;
546 transform_apply_fn
*reverse
;
547 transform_destroyinstance_fn
*destroy
;
550 struct transform_if
{
552 int capab_transformnum
;
553 int32_t keylen
; /* <<< INT_MAX */
554 transform_createinstance_fn
*create
;
557 /* NETLINK interface */
559 /* Used by netlink to deliver to site, and by site to deliver to
560 netlink. cid is the client identifier returned by
561 netlink_regnets_fn. If buf has size 0 then the function is just
562 being called for its site-effects (eg. making the site code attempt
563 to bring up a network link) */
564 typedef void netlink_deliver_fn(void *st
, struct buffer_if
*buf
);
565 /* site code can tell netlink when outgoing packets will be dropped,
566 so netlink can generate appropriate ICMP and make routing decisions */
567 #define LINK_QUALITY_UNUSED 0 /* This link is unused, do not make this netlink */
568 #define LINK_QUALITY_DOWN 1 /* No chance of a packet being delivered right away*/
569 #define LINK_QUALITY_DOWN_STALE_ADDRESS 2 /* Link down, old address information */
570 #define LINK_QUALITY_DOWN_CURRENT_ADDRESS 3 /* Link down, current address information */
571 #define LINK_QUALITY_UP 4 /* Link active */
572 #define MAXIMUM_LINK_QUALITY 3
573 typedef void netlink_link_quality_fn(void *st
, uint32_t quality
);
574 typedef void netlink_register_fn(void *st
, netlink_deliver_fn
*deliver
,
575 void *dst
, uint32_t *localmtu_r
/* NULL ok */);
576 typedef void netlink_output_config_fn(void *st
, struct buffer_if
*buf
);
577 typedef bool_t
netlink_check_config_fn(void *st
, struct buffer_if
*buf
);
578 typedef void netlink_set_mtu_fn(void *st
, int32_t new_mtu
);
581 netlink_register_fn
*reg
;
582 netlink_deliver_fn
*deliver
;
583 netlink_link_quality_fn
*set_quality
;
584 netlink_set_mtu_fn
*set_mtu
;
589 /* Returns public key as a malloced hex string */
590 typedef string_t
dh_makepublic_fn(void *st
, uint8_t *secret
,
592 /* Fills buffer (up to buflen) with shared secret */
593 typedef void dh_makeshared_fn(void *st
, uint8_t *secret
,
594 int32_t secretlen
, cstring_t rempublic
,
595 uint8_t *sharedsecret
, int32_t buflen
);
598 int32_t len
; /* Approximate size of modulus in bytes */
599 int32_t ceil_len
; /* Number of bytes just sufficient to contain modulus */
600 dh_makepublic_fn
*makepublic
;
601 dh_makeshared_fn
*makeshared
;
606 typedef void *hash_init_fn(void);
607 typedef void hash_update_fn(void *st
, const void *buf
, int32_t len
);
608 typedef void hash_final_fn(void *st
, uint8_t *digest
);
610 int32_t len
; /* Hash output length in bytes */
612 hash_update_fn
*update
;
613 hash_final_fn
*final
;
616 /* BUFFER interface */
620 cstring_t owner
; /* Set to constant string */
621 uint32_t flags
; /* How paranoid should we be? */
622 struct cloc loc
; /* Where we were defined */
625 int32_t size
; /* Size of buffer contents */
626 int32_t alloclen
; /* Total length allocated at base */
629 /***** LOG functions *****/
631 #define M_DEBUG_CONFIG 0x001
632 #define M_DEBUG_PHASE 0x002
633 #define M_DEBUG 0x004
635 #define M_NOTICE 0x010
636 #define M_WARNING 0x020
638 #define M_SECURITY 0x080
639 #define M_FATAL 0x100
641 /* The fatal() family of functions require messages that do not end in '\n' */
642 extern NORETURN(fatal(const char *message
, ...)) FORMAT(printf
,1,2);
643 extern NORETURN(fatal_perror(const char *message
, ...)) FORMAT(printf
,1,2);
644 extern NORETURN(fatal_status(int status
, const char *message
, ...))
646 extern NORETURN(fatal_perror_status(int status
, const char *message
, ...))
649 /* Convenient nonfatal logging. Requires message that does not end in '\n'.
650 * If class contains M_FATAL, exits (after entering PHASE_SHUTDOWN).
651 * lg, errnoval and loc may sensibly be 0. desc must NOT be 0.
652 * lg_[v]perror save and restore errno. */
653 void lg_vperror(struct log_if
*lg
, const char *desc
, struct cloc
*loc
,
654 int class, int errnoval
, const char *fmt
, va_list al
)
656 void lg_perror(struct log_if
*lg
, const char *desc
, struct cloc
*loc
,
657 int class, int errnoval
, const char *fmt
, ...)
659 void lg_exitstatus(struct log_if
*lg
, const char *desc
, struct cloc
*loc
,
660 int class, int status
, const char *progname
);
662 /* The cfgfatal() family of functions require messages that end in '\n' */
663 extern NORETURN(cfgfatal(struct cloc loc
, cstring_t facility
,
664 const char *message
, ...)) FORMAT(printf
,3,4);
665 extern void cfgfile_postreadcheck(struct cloc loc
, FILE *f
);
666 extern NORETURN(vcfgfatal_maybefile(FILE *maybe_f
, struct cloc loc
,
667 cstring_t facility
, const char *message
,
670 extern NORETURN(cfgfatal_maybefile(FILE *maybe_f
, struct cloc loc
,
672 const char *message
, ...))
675 extern void Message(uint32_t class, const char *message
, ...)
677 extern void log_from_fd(int fd
, cstring_t prefix
, struct log_if
*log
);
679 /***** END of log functions *****/
681 #define STRING2(x) #x
682 #define STRING(x) STRING2(x)
684 #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj))))
685 #define ARRAY_SIZE(ary) (sizeof((ary))/sizeof((ary)[0]))
688 * void COPY_OBJ( OBJECT& dst, const OBJECT& src);
689 * void COPY_ARRAY(OBJECT *dst, const OBJECT *src, INTEGER count);
690 * // Typesafe: we check that the type OBJECT is the same in both cases.
691 * // It is OK to use COPY_OBJ on an array object, provided it's
692 * // _actually_ the whole array object and not decayed into a
693 * // pointer (e.g. a formal parameter).
695 #define COPY_OBJ(dst,src) \
696 (&(dst)==&(src), memcpy(&(dst),&(src),sizeof((dst))))
697 #define COPY_ARRAY(dst,src,count) \
698 (&(dst)[0]==&(src)[0], memcpy((dst),(src),sizeof((dst)[0])*(count)))
700 #endif /* secnet_h */