314 lines · 7.5 KB · C
RawDownload
#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