[deliverable/linux.git] / include / linux / ceph / decode.h

#ifndef __CEPH_DECODE_H
#define __CEPH_DECODE_H

#include <linux/err.h>
#include <linux/bug.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <asm/unaligned.h>

#include <linux/ceph/types.h>

/*
 * in all cases,
 *   void **p     pointer to position pointer
 *   void *end    pointer to end of buffer (last byte + 1)
 */

static inline u64 ceph_decode_64(void **p)
{
	u64 v = get_unaligned_le64(*p);
	*p += sizeof(u64);
	return v;
}
static inline u32 ceph_decode_32(void **p)
{
	u32 v = get_unaligned_le32(*p);
	*p += sizeof(u32);
	return v;
}
static inline u16 ceph_decode_16(void **p)
{
	u16 v = get_unaligned_le16(*p);
	*p += sizeof(u16);
	return v;
}
static inline u8 ceph_decode_8(void **p)
{
	u8 v = *(u8 *)*p;
	(*p)++;
	return v;
}
static inline void ceph_decode_copy(void **p, void *pv, size_t n)
{
	memcpy(pv, *p, n);
	*p += n;
}

/*
 * bounds check input.
 */
static inline bool ceph_has_room(void **p, void *end, size_t n)
{
	return end >= *p && n <= end - *p;
}

#define ceph_decode_need(p, end, n, bad)			\
	do {							\
		if (!likely(ceph_has_room(p, end, n)))		\
			goto bad;				\
	} while (0)

#define ceph_decode_64_safe(p, end, v, bad)			\
	do {							\
		ceph_decode_need(p, end, sizeof(u64), bad);	\
		v = ceph_decode_64(p);				\
	} while (0)
#define ceph_decode_32_safe(p, end, v, bad)			\
	do {							\
		ceph_decode_need(p, end, sizeof(u32), bad);	\
		v = ceph_decode_32(p);				\
	} while (0)
#define ceph_decode_16_safe(p, end, v, bad)			\
	do {							\
		ceph_decode_need(p, end, sizeof(u16), bad);	\
		v = ceph_decode_16(p);				\
	} while (0)
#define ceph_decode_8_safe(p, end, v, bad)			\
	do {							\
		ceph_decode_need(p, end, sizeof(u8), bad);	\
		v = ceph_decode_8(p);				\
	} while (0)

#define ceph_decode_copy_safe(p, end, pv, n, bad)		\
	do {							\
		ceph_decode_need(p, end, n, bad);		\
		ceph_decode_copy(p, pv, n);			\
	} while (0)

/*
 * Allocate a buffer big enough to hold the wire-encoded string, and
 * decode the string into it.  The resulting string will always be
 * terminated with '\0'.  If successful, *p will be advanced
 * past the decoded data.  Also, if lenp is not a null pointer, the
 * length (not including the terminating '\0') will be recorded in
 * *lenp.  Note that a zero-length string is a valid return value.
 *
 * Returns a pointer to the newly-allocated string buffer, or a
 * pointer-coded errno if an error occurs.  Neither *p nor *lenp
 * will have been updated if an error is returned.
 *
 * There are two possible failures:
 *   - converting the string would require accessing memory at or
 *     beyond the "end" pointer provided (-ERANGE)
 *   - memory could not be allocated for the result (-ENOMEM)
 */
static inline char *ceph_extract_encoded_string(void **p, void *end,
						size_t *lenp, gfp_t gfp)
{
	u32 len;
	void *sp = *p;
	char *buf;

	ceph_decode_32_safe(&sp, end, len, bad);
	if (!ceph_has_room(&sp, end, len))
		goto bad;

	buf = kmalloc(len + 1, gfp);
	if (!buf)
		return ERR_PTR(-ENOMEM);

	if (len)
		memcpy(buf, sp, len);
	buf[len] = '\0';

	*p = (char *) *p + sizeof (u32) + len;
	if (lenp)
		*lenp = (size_t) len;

	return buf;

bad:
	return ERR_PTR(-ERANGE);
}

/*
 * struct ceph_timespec <-> struct timespec
 */
static inline void ceph_decode_timespec(struct timespec *ts,
					const struct ceph_timespec *tv)
{
	ts->tv_sec = (__kernel_time_t)le32_to_cpu(tv->tv_sec);
	ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec);
}
static inline void ceph_encode_timespec(struct ceph_timespec *tv,
					const struct timespec *ts)
{
	tv->tv_sec = cpu_to_le32((u32)ts->tv_sec);
	tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec);
}

/*
 * sockaddr_storage <-> ceph_sockaddr
 */
static inline void ceph_encode_addr(struct ceph_entity_addr *a)
{
	__be16 ss_family = htons(a->in_addr.ss_family);
	a->in_addr.ss_family = *(__u16 *)&ss_family;
}
static inline void ceph_decode_addr(struct ceph_entity_addr *a)
{
	__be16 ss_family = *(__be16 *)&a->in_addr.ss_family;
	a->in_addr.ss_family = ntohs(ss_family);
	WARN_ON(a->in_addr.ss_family == 512);
}

/*
 * encoders
 */
static inline void ceph_encode_64(void **p, u64 v)
{
	put_unaligned_le64(v, (__le64 *)*p);
	*p += sizeof(u64);
}
static inline void ceph_encode_32(void **p, u32 v)
{
	put_unaligned_le32(v, (__le32 *)*p);
	*p += sizeof(u32);
}
static inline void ceph_encode_16(void **p, u16 v)
{
	put_unaligned_le16(v, (__le16 *)*p);
	*p += sizeof(u16);
}
static inline void ceph_encode_8(void **p, u8 v)
{
	*(u8 *)*p = v;
	(*p)++;
}
static inline void ceph_encode_copy(void **p, const void *s, int len)
{
	memcpy(*p, s, len);
	*p += len;
}

/*
 * filepath, string encoders
 */
static inline void ceph_encode_filepath(void **p, void *end,
					u64 ino, const char *path)
{
	u32 len = path ? strlen(path) : 0;
	BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end);
	ceph_encode_8(p, 1);
	ceph_encode_64(p, ino);
	ceph_encode_32(p, len);
	if (len)
		memcpy(*p, path, len);
	*p += len;
}

static inline void ceph_encode_string(void **p, void *end,
				      const char *s, u32 len)
{
	BUG_ON(*p + sizeof(len) + len > end);
	ceph_encode_32(p, len);
	if (len)
		memcpy(*p, s, len);
	*p += len;
}

/*
 * version and length starting block encoders/decoders
 */

/* current code version (u8) + compat code version (u8) + len of struct (u32) */
#define CEPH_ENCODING_START_BLK_LEN 6

/**
 * ceph_start_encoding - start encoding block
 * @struct_v: current (code) version of the encoding
 * @struct_compat: oldest code version that can decode it
 * @struct_len: length of struct encoding
 */
static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat,
				       u32 struct_len)
{
	ceph_encode_8(p, struct_v);
	ceph_encode_8(p, struct_compat);
	ceph_encode_32(p, struct_len);
}

/**
 * ceph_start_decoding - start decoding block
 * @v: current version of the encoding that the code supports
 * @name: name of the struct (free-form)
 * @struct_v: out param for the encoding version
 * @struct_len: out param for the length of struct encoding
 *
 * Validates the length of struct encoding, so unsafe ceph_decode_*
 * variants can be used for decoding.
 */
static inline int ceph_start_decoding(void **p, void *end, u8 v,
				      const char *name, u8 *struct_v,
				      u32 *struct_len)
{
	u8 struct_compat;

	ceph_decode_need(p, end, CEPH_ENCODING_START_BLK_LEN, bad);
	*struct_v = ceph_decode_8(p);
	struct_compat = ceph_decode_8(p);
	if (v < struct_compat) {
		pr_warn("got struct_v %d struct_compat %d > %d of %s\n",
			*struct_v, struct_compat, v, name);
		return -EINVAL;
	}

	*struct_len = ceph_decode_32(p);
	ceph_decode_need(p, end, *struct_len, bad);
	return 0;

bad:
	return -ERANGE;
}

#define ceph_encode_need(p, end, n, bad)			\
	do {							\
		if (!likely(ceph_has_room(p, end, n)))		\
			goto bad;				\
	} while (0)

#define ceph_encode_64_safe(p, end, v, bad)			\
	do {							\
		ceph_encode_need(p, end, sizeof(u64), bad);	\
		ceph_encode_64(p, v);				\
	} while (0)
#define ceph_encode_32_safe(p, end, v, bad)			\
	do {							\
		ceph_encode_need(p, end, sizeof(u32), bad);	\
		ceph_encode_32(p, v);				\
	} while (0)
#define ceph_encode_16_safe(p, end, v, bad)			\
	do {							\
		ceph_encode_need(p, end, sizeof(u16), bad);	\
		ceph_encode_16(p, v);				\
	} while (0)
#define ceph_encode_8_safe(p, end, v, bad)			\
	do {							\
		ceph_encode_need(p, end, sizeof(u8), bad);	\
		ceph_encode_8(p, v);				\
	} while (0)

#define ceph_encode_copy_safe(p, end, pv, n, bad)		\
	do {							\
		ceph_encode_need(p, end, n, bad);		\
		ceph_encode_copy(p, pv, n);			\
	} while (0)
#define ceph_encode_string_safe(p, end, s, n, bad)		\
	do {							\
		ceph_encode_need(p, end, n, bad);		\
		ceph_encode_string(p, end, s, n);		\
	} while (0)


#endif
Commit	Line	Data
31b8006e SW	1	#ifndef __CEPH_DECODE_H
	2	#define __CEPH_DECODE_H
	3
f8c36c58	4	#include <linux/err.h>
187f1882	5	#include <linux/bug.h>
b2aa5d0b	6	#include <linux/slab.h>
c7e337d6	7	#include <linux/time.h>
187f1882	8	#include <asm/unaligned.h>
31b8006e	9
a1ce3928	10	#include <linux/ceph/types.h>
c89136ea	11
31b8006e SW	12	/*
	13	* in all cases,
	14	* void **p pointer to position pointer
	15	* void *end pointer to end of buffer (last byte + 1)
	16	*/
	17
c89136ea SW	18	static inline u64 ceph_decode_64(void **p)
	19	{
	20	u64 v = get_unaligned_le64(*p);
	21	*p += sizeof(u64);
	22	return v;
	23	}
	24	static inline u32 ceph_decode_32(void **p)
	25	{
	26	u32 v = get_unaligned_le32(*p);
	27	*p += sizeof(u32);
	28	return v;
	29	}
	30	static inline u16 ceph_decode_16(void **p)
	31	{
	32	u16 v = get_unaligned_le16(*p);
	33	*p += sizeof(u16);
	34	return v;
	35	}
	36	static inline u8 ceph_decode_8(void **p)
	37	{
	38	u8 v = (u8 )*p;
	39	(*p)++;
	40	return v;
	41	}
	42	static inline void ceph_decode_copy(void *p, void pv, size_t n)
	43	{
	44	memcpy(pv, *p, n);
	45	*p += n;
	46	}
	47
31b8006e SW	48	/*
	49	* bounds check input.
	50	*/
3b33f692	51	static inline bool ceph_has_room(void *p, void end, size_t n)
76aa542f XW	52	{
	53	return end >= p && n <= end - p;
	54	}
	55
dd5f049d AE	56	#define ceph_decode_need(p, end, n, bad) \
	57	do { \
	58	if (!likely(ceph_has_room(p, end, n))) \
	59	goto bad; \
31b8006e SW	60	} while (0)
31b8006e SW	61
31b8006e SW	62	#define ceph_decode_64_safe(p, end, v, bad) \
	63	do { \
	64	ceph_decode_need(p, end, sizeof(u64), bad); \
c89136ea	65	v = ceph_decode_64(p); \
31b8006e SW	66	} while (0)
	67	#define ceph_decode_32_safe(p, end, v, bad) \
	68	do { \
	69	ceph_decode_need(p, end, sizeof(u32), bad); \
c89136ea	70	v = ceph_decode_32(p); \
31b8006e SW	71	} while (0)
	72	#define ceph_decode_16_safe(p, end, v, bad) \
	73	do { \
	74	ceph_decode_need(p, end, sizeof(u16), bad); \
c89136ea	75	v = ceph_decode_16(p); \
31b8006e	76	} while (0)
c7e337d6 SW	77	#define ceph_decode_8_safe(p, end, v, bad) \
	78	do { \
	79	ceph_decode_need(p, end, sizeof(u8), bad); \
	80	v = ceph_decode_8(p); \
	81	} while (0)
31b8006e SW	82
	83	#define ceph_decode_copy_safe(p, end, pv, n, bad) \
	84	do { \
	85	ceph_decode_need(p, end, n, bad); \
	86	ceph_decode_copy(p, pv, n); \
	87	} while (0)
	88
f8c36c58 AE	89	/*
	90	* Allocate a buffer big enough to hold the wire-encoded string, and
	91	* decode the string into it. The resulting string will always be
	92	* terminated with '\0'. If successful, *p will be advanced
	93	* past the decoded data. Also, if lenp is not a null pointer, the
	94	* length (not including the terminating '\0') will be recorded in
	95	* *lenp. Note that a zero-length string is a valid return value.
	96	*
	97	* Returns a pointer to the newly-allocated string buffer, or a
	98	* pointer-coded errno if an error occurs. Neither p nor lenp
	99	* will have been updated if an error is returned.
	100	*
	101	* There are two possible failures:
	102	* - converting the string would require accessing memory at or
dd5f049d AE	103	* beyond the "end" pointer provided (-ERANGE)
dd5f049d AE	104	* - memory could not be allocated for the result (-ENOMEM)
f8c36c58 AE	105	*/
	106	static inline char ceph_extract_encoded_string(void p, void end,
	107	size_t *lenp, gfp_t gfp)
	108	{
	109	u32 len;
	110	void sp = p;
	111	char *buf;
	112
	113	ceph_decode_32_safe(&sp, end, len, bad);
	114	if (!ceph_has_room(&sp, end, len))
	115	goto bad;
	116
	117	buf = kmalloc(len + 1, gfp);
	118	if (!buf)
	119	return ERR_PTR(-ENOMEM);
	120
	121	if (len)
	122	memcpy(buf, sp, len);
	123	buf[len] = '\0';
	124
	125	p = (char ) *p + sizeof (u32) + len;
	126	if (lenp)
	127	*lenp = (size_t) len;
	128
	129	return buf;
	130
	131	bad:
	132	return ERR_PTR(-ERANGE);
	133	}
	134
31b8006e SW	135	/*
	136	* struct ceph_timespec <-> struct timespec
	137	*/
c89136ea	138	static inline void ceph_decode_timespec(struct timespec *ts,
63f2d211	139	const struct ceph_timespec *tv)
c89136ea	140	{
c3f56102 AE	141	ts->tv_sec = (__kernel_time_t)le32_to_cpu(tv->tv_sec);
c3f56102 AE	142	ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec);
c89136ea SW	143	}
c89136ea SW	144	static inline void ceph_encode_timespec(struct ceph_timespec *tv,
63f2d211	145	const struct timespec *ts)
c89136ea	146	{
c3f56102 AE	147	tv->tv_sec = cpu_to_le32((u32)ts->tv_sec);
c3f56102 AE	148	tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec);
c89136ea	149	}
31b8006e	150
63f2d211 SW	151	/*
	152	* sockaddr_storage <-> ceph_sockaddr
	153	*/
	154	static inline void ceph_encode_addr(struct ceph_entity_addr *a)
	155	{
cd84db6e YS	156	__be16 ss_family = htons(a->in_addr.ss_family);
cd84db6e YS	157	a->in_addr.ss_family = (__u16 )&ss_family;
63f2d211 SW	158	}
	159	static inline void ceph_decode_addr(struct ceph_entity_addr *a)
	160	{
cd84db6e YS	161	__be16 ss_family = (__be16 )&a->in_addr.ss_family;
cd84db6e YS	162	a->in_addr.ss_family = ntohs(ss_family);
4e7a5dcd	163	WARN_ON(a->in_addr.ss_family == 512);
63f2d211 SW	164	}
63f2d211 SW	165
31b8006e SW	166	/*
	167	* encoders
	168	*/
c89136ea SW	169	static inline void ceph_encode_64(void **p, u64 v)
	170	{
	171	put_unaligned_le64(v, (__le64 )p);
	172	*p += sizeof(u64);
	173	}
	174	static inline void ceph_encode_32(void **p, u32 v)
	175	{
	176	put_unaligned_le32(v, (__le32 )p);
	177	*p += sizeof(u32);
	178	}
	179	static inline void ceph_encode_16(void **p, u16 v)
	180	{
	181	put_unaligned_le16(v, (__le16 )p);
	182	*p += sizeof(u16);
	183	}
	184	static inline void ceph_encode_8(void **p, u8 v)
	185	{
	186	(u8 )*p = v;
	187	(*p)++;
	188	}
4e7a5dcd SW	189	static inline void ceph_encode_copy(void *p, const void s, int len)
	190	{
	191	memcpy(*p, s, len);
	192	*p += len;
	193	}
31b8006e SW	194
	195	/*
	196	* filepath, string encoders
	197	*/
	198	static inline void ceph_encode_filepath(void *p, void end,
	199	u64 ino, const char *path)
	200	{
	201	u32 len = path ? strlen(path) : 0;
c61a1abd	202	BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end);
ac8839d7	203	ceph_encode_8(p, 1);
31b8006e SW	204	ceph_encode_64(p, ino);
	205	ceph_encode_32(p, len);
	206	if (len)
	207	memcpy(*p, path, len);
	208	*p += len;
	209	}
	210
	211	static inline void ceph_encode_string(void *p, void end,
	212	const char *s, u32 len)
	213	{
	214	BUG_ON(*p + sizeof(len) + len > end);
	215	ceph_encode_32(p, len);
	216	if (len)
	217	memcpy(*p, s, len);
	218	*p += len;
	219	}
	220
22748f9d ID	221	/*
	222	* version and length starting block encoders/decoders
	223	*/
	224
	225	/* current code version (u8) + compat code version (u8) + len of struct (u32) */
	226	#define CEPH_ENCODING_START_BLK_LEN 6
	227
	228	/**
	229	* ceph_start_encoding - start encoding block
	230	* @struct_v: current (code) version of the encoding
	231	* @struct_compat: oldest code version that can decode it
	232	* @struct_len: length of struct encoding
	233	*/
	234	static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat,
	235	u32 struct_len)
	236	{
	237	ceph_encode_8(p, struct_v);
	238	ceph_encode_8(p, struct_compat);
	239	ceph_encode_32(p, struct_len);
	240	}
	241
	242	/**
	243	* ceph_start_decoding - start decoding block
	244	* @v: current version of the encoding that the code supports
	245	* @name: name of the struct (free-form)
	246	* @struct_v: out param for the encoding version
	247	* @struct_len: out param for the length of struct encoding
	248	*
	249	* Validates the length of struct encoding, so unsafe ceph_decode_*
	250	* variants can be used for decoding.
	251	*/
	252	static inline int ceph_start_decoding(void *p, void end, u8 v,
	253	const char name, u8 struct_v,
	254	u32 *struct_len)
	255	{
	256	u8 struct_compat;
	257
	258	ceph_decode_need(p, end, CEPH_ENCODING_START_BLK_LEN, bad);
	259	*struct_v = ceph_decode_8(p);
	260	struct_compat = ceph_decode_8(p);
	261	if (v < struct_compat) {
	262	pr_warn("got struct_v %d struct_compat %d > %d of %s\n",
	263	*struct_v, struct_compat, v, name);
	264	return -EINVAL;
	265	}
	266
	267	*struct_len = ceph_decode_32(p);
	268	ceph_decode_need(p, end, *struct_len, bad);
	269	return 0;
	270
	271	bad:
	272	return -ERANGE;
	273	}
	274
dd5f049d AE	275	#define ceph_encode_need(p, end, n, bad) \
	276	do { \
	277	if (!likely(ceph_has_room(p, end, n))) \
	278	goto bad; \
c7e337d6 SW	279	} while (0)
	280
	281	#define ceph_encode_64_safe(p, end, v, bad) \
	282	do { \
	283	ceph_encode_need(p, end, sizeof(u64), bad); \
	284	ceph_encode_64(p, v); \
	285	} while (0)
	286	#define ceph_encode_32_safe(p, end, v, bad) \
	287	do { \
	288	ceph_encode_need(p, end, sizeof(u32), bad); \
dd5f049d	289	ceph_encode_32(p, v); \
c7e337d6 SW	290	} while (0)
	291	#define ceph_encode_16_safe(p, end, v, bad) \
	292	do { \
	293	ceph_encode_need(p, end, sizeof(u16), bad); \
dd5f049d AE	294	ceph_encode_16(p, v); \
	295	} while (0)
	296	#define ceph_encode_8_safe(p, end, v, bad) \
	297	do { \
	298	ceph_encode_need(p, end, sizeof(u8), bad); \
	299	ceph_encode_8(p, v); \
c7e337d6 SW	300	} while (0)
	301
	302	#define ceph_encode_copy_safe(p, end, pv, n, bad) \
	303	do { \
	304	ceph_encode_need(p, end, n, bad); \
	305	ceph_encode_copy(p, pv, n); \
	306	} while (0)
ae1533b6 YS	307	#define ceph_encode_string_safe(p, end, s, n, bad) \
	308	do { \
	309	ceph_encode_need(p, end, n, bad); \
	310	ceph_encode_string(p, end, s, n); \
	311	} while (0)
c7e337d6	312
31b8006e SW	313
31b8006e SW	314	#endif