[thirdparty/lldpd.git] / src / marshal.h

/* -*- mode: c; c-file-style: "openbsd" -*- */
/*
 * Copyright (c) 2012 Vincent Bernat <bernat@luffy.cx>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _MARSHAL_H
#define _MARSHAL_H

#include <stddef.h>
#include <stdint.h>
#include <sys/types.h>

struct marshal_info;
enum marshal_subinfo_kind {
	pointer,
	substruct,
	ignore,
};
#define MARSHAL_INFO_POINTER 1
#define MARSHAL_INFO_SUB 2
struct marshal_subinfo {
	size_t offset;			/* Offset compared to parent structure */
	size_t offset2;			/* Ancillary offset (for related data) */
	enum marshal_subinfo_kind kind; /* Kind of substructure */
	struct marshal_info *mi;
};
#define MARSHAL_SUBINFO_NULL                              \
  {                                                       \
    .offset = 0, .offset2 = 0, .kind = ignore, .mi = NULL \
  }
struct marshal_info {
	const char *name; /* Name of structure */
	size_t size;	  /* Size of the structure */
#if defined __GNUC__ && __GNUC__ < 3
	/* With gcc 2.96, flexible arrays are not supported, even with
	 * -std=gnu99. And with gcc 3.x, zero-sized arrays cannot be statically
	 * initialized (with more than one element). */
	struct marshal_subinfo pointers[0]; /* Pointer to other structures */
#else
	struct marshal_subinfo pointers[]; /* Pointer to other structures */
#endif
};
/* Special case for strings */
extern struct marshal_info marshal_info_string;
extern struct marshal_info marshal_info_fstring;
extern struct marshal_info marshal_info_ignore;

/* Declare a new marshal_info struct named after the type we want to
   marshal. The marshalled type has to be a structure. */
#define MARSHAL_INFO(type) marshal_info_##type
#ifdef MARSHAL_EXPORT
#  define MARSHAL_HELPER_FUNCTIONS(type, ttype)                               \
    ssize_t type##_serialize(ttype *source, void *buffer);                    \
    ssize_t type##_serialize(ttype *source, void *buffer)                     \
    {                                                                         \
      return marshal_serialize(type, source, buffer);                         \
    }                                                                         \
    size_t type##_unserialize(void *buffer, size_t len, ttype **destination); \
    size_t type##_unserialize(void *buffer, size_t len, ttype **destination)  \
    {                                                                         \
      void *p;                                                                \
      size_t rc;                                                              \
      rc = marshal_unserialize(type, buffer, len, &p);                        \
      if (rc <= 0) return rc;                                                 \
      *destination = p;                                                       \
      return rc;                                                              \
    }
#  define MARSHAL_BEGIN(type)         \
    struct marshal_info MARSHAL_INFO( \
	type) = { .name = #type, .size = sizeof(struct type), .pointers = {
#  define MARSHAL_ADD(_kind, type, subtype, member) \
    { .offset = offsetof(struct type, member),      \
	    .offset2 = 0,                           \
	    .kind = _kind,                          \
	    .mi = &MARSHAL_INFO(subtype) },
#  define MARSHAL_FSTR(type, member, len)          \
    { .offset = offsetof(struct type, member),     \
	    .offset2 = offsetof(struct type, len), \
	    .kind = pointer,                       \
	    .mi = &marshal_info_fstring },
#  define MARSHAL_END(type) \
    MARSHAL_SUBINFO_NULL    \
    }                       \
    }                       \
    ;                       \
    MARSHAL_HELPER_FUNCTIONS(type, struct type)
#else
#  define MARSHAL_HELPER_FUNCTIONS(type, ttype) \
    ssize_t type##_serialize(ttype *, void *);  \
    size_t type##_unserialize(void *, size_t, ttype **);
#  define MARSHAL_BEGIN(type) extern struct marshal_info MARSHAL_INFO(type);
#  define MARSHAL_ADD(...)
#  define MARSHAL_FSTR(...)
#  define MARSHAL_END(type) MARSHAL_HELPER_FUNCTIONS(type, struct type)
#endif
/* Shortcuts */
#define MARSHAL_POINTER(...) MARSHAL_ADD(pointer, ##__VA_ARGS__)
#define MARSHAL_SUBSTRUCT(...) MARSHAL_ADD(substruct, ##__VA_ARGS__)
#define MARSHAL_STR(type, member) MARSHAL_ADD(pointer, type, string, member)
#define MARSHAL_IGNORE(type, member) MARSHAL_ADD(ignore, type, ignore, member)
#define MARSHAL_TQE(type, field)              \
  MARSHAL_POINTER(type, type, field.tqe_next) \
  MARSHAL_IGNORE(type, field.tqe_prev)
/* Support for TAILQ list is partial. Access to last and previous
   elements is not available. Some operations are therefore not
   possible. However, TAILQ_FOREACH is still
   available. */
#define MARSHAL_TQH(type, subtype)          \
  MARSHAL_POINTER(type, subtype, tqh_first) \
  MARSHAL_IGNORE(type, tqh_last)
#define MARSHAL_SUBTQ(type, subtype, field)       \
  MARSHAL_POINTER(type, subtype, field.tqh_first) \
  MARSHAL_IGNORE(type, field.tqh_last)
#define MARSHAL(type) \
  MARSHAL_BEGIN(type) \
  MARSHAL_END(type)
#define MARSHAL_TQ(type, subtype) \
  MARSHAL_BEGIN(type)             \
  MARSHAL_TQH(type, subtype)      \
  MARSHAL_END(type)

/* Serialization */
ssize_t marshal_serialize_(struct marshal_info *, void *, void **, int, void *, int)
    __attribute__((nonnull(1, 2, 3)));
#define marshal_serialize(type, o, output) \
  marshal_serialize_(&MARSHAL_INFO(type), o, output, 0, NULL, 0)

/* Unserialization */
size_t marshal_unserialize_(struct marshal_info *, void *, size_t, void **, void *, int,
    int) __attribute__((nonnull(1, 2, 4)));
#define marshal_unserialize(type, o, l, input) \
  marshal_unserialize_(&MARSHAL_INFO(type), o, l, input, NULL, 0, 0)

#define marshal_repair_tailq(type, head, field)                              \
  do {                                                                       \
    struct type *__item, *__item_next;                                       \
    (head)->tqh_last = &(head)->tqh_first;                                   \
    for (__item = TAILQ_FIRST(head); __item != NULL; __item = __item_next) { \
      __item_next = TAILQ_NEXT(__item, field);                               \
      __item->field.tqe_prev = (head)->tqh_last;                             \
      *(head)->tqh_last = __item;                                            \
      (head)->tqh_last = &__item->field.tqe_next;                            \
    }                                                                        \
  } while (0)

#endif
Commit	Line	Data
	1	/* -- mode: c; c-file-style: "openbsd" -- */
	2	/*
	3	* Copyright (c) 2012 Vincent Bernat <bernat@luffy.cx>
	4	*
	5	* Permission to use, copy, modify, and/or distribute this software for any
	6	* purpose with or without fee is hereby granted, provided that the above
	7	* copyright notice and this permission notice appear in all copies.
	8	*
	9	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	10	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	11	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	12	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	13	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	14	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	15	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	16	*/
	17
	18	#ifndef _MARSHAL_H
	19	#define _MARSHAL_H
	20
	21	#include <stddef.h>
	22	#include <stdint.h>
	23	#include <sys/types.h>
	24
	25	struct marshal_info;
	26	enum marshal_subinfo_kind {
	27	pointer,
	28	substruct,
	29	ignore,
	30	};
	31	#define MARSHAL_INFO_POINTER 1
	32	#define MARSHAL_INFO_SUB 2
	33	struct marshal_subinfo {
	34	size_t offset; /* Offset compared to parent structure */
	35	size_t offset2; /* Ancillary offset (for related data) */
	36	enum marshal_subinfo_kind kind; /* Kind of substructure */
	37	struct marshal_info *mi;
	38	};
	39	#define MARSHAL_SUBINFO_NULL \
	40	{ \
	41	.offset = 0, .offset2 = 0, .kind = ignore, .mi = NULL \
	42	}
	43	struct marshal_info {
	44	const char name; / Name of structure */
	45	size_t size; /* Size of the structure */
	46	#if defined __GNUC__ && __GNUC__ < 3
	47	/* With gcc 2.96, flexible arrays are not supported, even with
	48	* -std=gnu99. And with gcc 3.x, zero-sized arrays cannot be statically
	49	* initialized (with more than one element). */
	50	struct marshal_subinfo pointers[0]; /* Pointer to other structures */
	51	#else
	52	struct marshal_subinfo pointers[]; /* Pointer to other structures */
	53	#endif
	54	};
	55	/* Special case for strings */
	56	extern struct marshal_info marshal_info_string;
	57	extern struct marshal_info marshal_info_fstring;
	58	extern struct marshal_info marshal_info_ignore;
	59
	60	/* Declare a new marshal_info struct named after the type we want to
	61	marshal. The marshalled type has to be a structure. */
	62	#define MARSHAL_INFO(type) marshal_info_##type
	63	#ifdef MARSHAL_EXPORT
	64	# define MARSHAL_HELPER_FUNCTIONS(type, ttype) \
	65	ssize_t type##_serialize(ttype source, void buffer); \
	66	ssize_t type##_serialize(ttype source, void buffer) \
	67	{ \
	68	return marshal_serialize(type, source, buffer); \
	69	} \
	70	size_t type##_unserialize(void buffer, size_t len, ttype *destination); \
	71	size_t type##_unserialize(void buffer, size_t len, ttype *destination) \
	72	{ \
	73	void *p; \
	74	size_t rc; \
	75	rc = marshal_unserialize(type, buffer, len, &p); \
	76	if (rc <= 0) return rc; \
	77	*destination = p; \
	78	return rc; \
	79	}
	80	# define MARSHAL_BEGIN(type) \
	81	struct marshal_info MARSHAL_INFO( \
	82	type) = { .name = #type, .size = sizeof(struct type), .pointers = {
	83	# define MARSHAL_ADD(_kind, type, subtype, member) \
	84	{ .offset = offsetof(struct type, member), \
	85	.offset2 = 0, \
	86	.kind = _kind, \
	87	.mi = &MARSHAL_INFO(subtype) },
	88	# define MARSHAL_FSTR(type, member, len) \
	89	{ .offset = offsetof(struct type, member), \
	90	.offset2 = offsetof(struct type, len), \
	91	.kind = pointer, \
	92	.mi = &marshal_info_fstring },
	93	# define MARSHAL_END(type) \
	94	MARSHAL_SUBINFO_NULL \
	95	} \
	96	} \
	97	; \
	98	MARSHAL_HELPER_FUNCTIONS(type, struct type)
	99	#else
	100	# define MARSHAL_HELPER_FUNCTIONS(type, ttype) \
	101	ssize_t type##_serialize(ttype , void ); \
	102	size_t type##_unserialize(void , size_t, ttype *);
	103	# define MARSHAL_BEGIN(type) extern struct marshal_info MARSHAL_INFO(type);
	104	# define MARSHAL_ADD(...)
	105	# define MARSHAL_FSTR(...)
	106	# define MARSHAL_END(type) MARSHAL_HELPER_FUNCTIONS(type, struct type)
	107	#endif
	108	/* Shortcuts */
	109	#define MARSHAL_POINTER(...) MARSHAL_ADD(pointer, ##__VA_ARGS__)
	110	#define MARSHAL_SUBSTRUCT(...) MARSHAL_ADD(substruct, ##__VA_ARGS__)
	111	#define MARSHAL_STR(type, member) MARSHAL_ADD(pointer, type, string, member)
	112	#define MARSHAL_IGNORE(type, member) MARSHAL_ADD(ignore, type, ignore, member)
	113	#define MARSHAL_TQE(type, field) \
	114	MARSHAL_POINTER(type, type, field.tqe_next) \
	115	MARSHAL_IGNORE(type, field.tqe_prev)
	116	/* Support for TAILQ list is partial. Access to last and previous
	117	elements is not available. Some operations are therefore not
	118	possible. However, TAILQ_FOREACH is still
	119	available. */
	120	#define MARSHAL_TQH(type, subtype) \
	121	MARSHAL_POINTER(type, subtype, tqh_first) \
	122	MARSHAL_IGNORE(type, tqh_last)
	123	#define MARSHAL_SUBTQ(type, subtype, field) \
	124	MARSHAL_POINTER(type, subtype, field.tqh_first) \
	125	MARSHAL_IGNORE(type, field.tqh_last)
	126	#define MARSHAL(type) \
	127	MARSHAL_BEGIN(type) \
	128	MARSHAL_END(type)
	129	#define MARSHAL_TQ(type, subtype) \
	130	MARSHAL_BEGIN(type) \
	131	MARSHAL_TQH(type, subtype) \
	132	MARSHAL_END(type)
	133
	134	/* Serialization */
	135	ssize_t marshal_serialize_(struct marshal_info , void , void *, int, void , int)
	136	__attribute__((nonnull(1, 2, 3)));
	137	#define marshal_serialize(type, o, output) \
	138	marshal_serialize_(&MARSHAL_INFO(type), o, output, 0, NULL, 0)
	139
	140	/* Unserialization */
	141	size_t marshal_unserialize_(struct marshal_info , void , size_t, void *, void , int,
	142	int) __attribute__((nonnull(1, 2, 4)));
	143	#define marshal_unserialize(type, o, l, input) \
	144	marshal_unserialize_(&MARSHAL_INFO(type), o, l, input, NULL, 0, 0)
	145
	146	#define marshal_repair_tailq(type, head, field) \
	147	do { \
	148	struct type __item, __item_next; \
	149	(head)->tqh_last = &(head)->tqh_first; \
	150	for (__item = TAILQ_FIRST(head); __item != NULL; __item = __item_next) { \
	151	__item_next = TAILQ_NEXT(__item, field); \
	152	__item->field.tqe_prev = (head)->tqh_last; \
	153	*(head)->tqh_last = __item; \
	154	(head)->tqh_last = &__item->field.tqe_next; \
	155	} \
	156	} while (0)
	157
	158	#endif