382 lines
9.3 KiB
C
382 lines
9.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __CEPH_DECODE_H
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#define __CEPH_DECODE_H
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#include <linux/err.h>
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#include <linux/bug.h>
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#include <linux/slab.h>
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#include <linux/time.h>
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#include <asm/unaligned.h>
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#include <linux/ceph/types.h>
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/*
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* in all cases,
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* void **p pointer to position pointer
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* void *end pointer to end of buffer (last byte + 1)
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*/
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static inline u64 ceph_decode_64(void **p)
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{
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u64 v = get_unaligned_le64(*p);
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*p += sizeof(u64);
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return v;
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}
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static inline u32 ceph_decode_32(void **p)
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{
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u32 v = get_unaligned_le32(*p);
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*p += sizeof(u32);
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return v;
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}
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static inline u16 ceph_decode_16(void **p)
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{
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u16 v = get_unaligned_le16(*p);
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*p += sizeof(u16);
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return v;
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}
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static inline u8 ceph_decode_8(void **p)
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{
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u8 v = *(u8 *)*p;
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(*p)++;
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return v;
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}
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static inline void ceph_decode_copy(void **p, void *pv, size_t n)
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{
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memcpy(pv, *p, n);
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*p += n;
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}
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/*
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* bounds check input.
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*/
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static inline bool ceph_has_room(void **p, void *end, size_t n)
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{
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return end >= *p && n <= end - *p;
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}
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#define ceph_decode_need(p, end, n, bad) \
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do { \
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if (!likely(ceph_has_room(p, end, n))) \
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goto bad; \
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} while (0)
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#define ceph_decode_64_safe(p, end, v, bad) \
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do { \
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ceph_decode_need(p, end, sizeof(u64), bad); \
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v = ceph_decode_64(p); \
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} while (0)
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#define ceph_decode_32_safe(p, end, v, bad) \
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do { \
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ceph_decode_need(p, end, sizeof(u32), bad); \
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v = ceph_decode_32(p); \
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} while (0)
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#define ceph_decode_16_safe(p, end, v, bad) \
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do { \
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ceph_decode_need(p, end, sizeof(u16), bad); \
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v = ceph_decode_16(p); \
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} while (0)
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#define ceph_decode_8_safe(p, end, v, bad) \
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do { \
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ceph_decode_need(p, end, sizeof(u8), bad); \
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v = ceph_decode_8(p); \
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} while (0)
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#define ceph_decode_copy_safe(p, end, pv, n, bad) \
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do { \
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ceph_decode_need(p, end, n, bad); \
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ceph_decode_copy(p, pv, n); \
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} while (0)
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/*
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* Allocate a buffer big enough to hold the wire-encoded string, and
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* decode the string into it. The resulting string will always be
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* terminated with '\0'. If successful, *p will be advanced
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* past the decoded data. Also, if lenp is not a null pointer, the
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* length (not including the terminating '\0') will be recorded in
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* *lenp. Note that a zero-length string is a valid return value.
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*
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* Returns a pointer to the newly-allocated string buffer, or a
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* pointer-coded errno if an error occurs. Neither *p nor *lenp
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* will have been updated if an error is returned.
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*
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* There are two possible failures:
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* - converting the string would require accessing memory at or
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* beyond the "end" pointer provided (-ERANGE)
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* - memory could not be allocated for the result (-ENOMEM)
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*/
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static inline char *ceph_extract_encoded_string(void **p, void *end,
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size_t *lenp, gfp_t gfp)
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{
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u32 len;
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void *sp = *p;
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char *buf;
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ceph_decode_32_safe(&sp, end, len, bad);
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if (!ceph_has_room(&sp, end, len))
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goto bad;
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buf = kmalloc(len + 1, gfp);
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if (!buf)
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return ERR_PTR(-ENOMEM);
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if (len)
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memcpy(buf, sp, len);
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buf[len] = '\0';
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*p = (char *) *p + sizeof (u32) + len;
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if (lenp)
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*lenp = (size_t) len;
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return buf;
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bad:
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return ERR_PTR(-ERANGE);
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}
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/*
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* skip helpers
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*/
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#define ceph_decode_skip_n(p, end, n, bad) \
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do { \
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ceph_decode_need(p, end, n, bad); \
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*p += n; \
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} while (0)
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#define ceph_decode_skip_64(p, end, bad) \
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ceph_decode_skip_n(p, end, sizeof(u64), bad)
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#define ceph_decode_skip_32(p, end, bad) \
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ceph_decode_skip_n(p, end, sizeof(u32), bad)
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#define ceph_decode_skip_16(p, end, bad) \
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ceph_decode_skip_n(p, end, sizeof(u16), bad)
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#define ceph_decode_skip_8(p, end, bad) \
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ceph_decode_skip_n(p, end, sizeof(u8), bad)
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#define ceph_decode_skip_string(p, end, bad) \
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do { \
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u32 len; \
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\
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ceph_decode_32_safe(p, end, len, bad); \
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ceph_decode_skip_n(p, end, len, bad); \
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} while (0)
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#define ceph_decode_skip_set(p, end, type, bad) \
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do { \
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u32 len; \
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\
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ceph_decode_32_safe(p, end, len, bad); \
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while (len--) \
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ceph_decode_skip_##type(p, end, bad); \
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} while (0)
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#define ceph_decode_skip_map(p, end, ktype, vtype, bad) \
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do { \
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u32 len; \
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\
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ceph_decode_32_safe(p, end, len, bad); \
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while (len--) { \
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ceph_decode_skip_##ktype(p, end, bad); \
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ceph_decode_skip_##vtype(p, end, bad); \
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} \
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} while (0)
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#define ceph_decode_skip_map_of_map(p, end, ktype1, ktype2, vtype2, bad) \
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do { \
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u32 len; \
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\
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ceph_decode_32_safe(p, end, len, bad); \
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while (len--) { \
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ceph_decode_skip_##ktype1(p, end, bad); \
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ceph_decode_skip_map(p, end, ktype2, vtype2, bad); \
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} \
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} while (0)
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/*
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* struct ceph_timespec <-> struct timespec64
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*/
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static inline void ceph_decode_timespec64(struct timespec64 *ts,
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const struct ceph_timespec *tv)
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{
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/*
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* This will still overflow in year 2106. We could extend
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* the protocol to steal two more bits from tv_nsec to
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* add three more 136 year epochs after that the way ext4
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* does if necessary.
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*/
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ts->tv_sec = (time64_t)le32_to_cpu(tv->tv_sec);
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ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec);
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}
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static inline void ceph_encode_timespec64(struct ceph_timespec *tv,
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const struct timespec64 *ts)
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{
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tv->tv_sec = cpu_to_le32((u32)ts->tv_sec);
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tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec);
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}
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/*
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* sockaddr_storage <-> ceph_sockaddr
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*/
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static inline void ceph_encode_addr(struct ceph_entity_addr *a)
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{
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__be16 ss_family = htons(a->in_addr.ss_family);
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a->in_addr.ss_family = *(__u16 *)&ss_family;
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}
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static inline void ceph_decode_addr(struct ceph_entity_addr *a)
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{
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__be16 ss_family = *(__be16 *)&a->in_addr.ss_family;
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a->in_addr.ss_family = ntohs(ss_family);
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WARN_ON(a->in_addr.ss_family == 512);
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}
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/*
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* encoders
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*/
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static inline void ceph_encode_64(void **p, u64 v)
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{
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put_unaligned_le64(v, (__le64 *)*p);
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*p += sizeof(u64);
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}
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static inline void ceph_encode_32(void **p, u32 v)
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{
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put_unaligned_le32(v, (__le32 *)*p);
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*p += sizeof(u32);
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}
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static inline void ceph_encode_16(void **p, u16 v)
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{
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put_unaligned_le16(v, (__le16 *)*p);
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*p += sizeof(u16);
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}
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static inline void ceph_encode_8(void **p, u8 v)
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{
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*(u8 *)*p = v;
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(*p)++;
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}
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static inline void ceph_encode_copy(void **p, const void *s, int len)
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{
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memcpy(*p, s, len);
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*p += len;
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}
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/*
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* filepath, string encoders
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*/
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static inline void ceph_encode_filepath(void **p, void *end,
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u64 ino, const char *path)
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{
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u32 len = path ? strlen(path) : 0;
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BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end);
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ceph_encode_8(p, 1);
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ceph_encode_64(p, ino);
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ceph_encode_32(p, len);
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if (len)
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memcpy(*p, path, len);
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*p += len;
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}
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static inline void ceph_encode_string(void **p, void *end,
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const char *s, u32 len)
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{
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BUG_ON(*p + sizeof(len) + len > end);
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ceph_encode_32(p, len);
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if (len)
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memcpy(*p, s, len);
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*p += len;
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}
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/*
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* version and length starting block encoders/decoders
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*/
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/* current code version (u8) + compat code version (u8) + len of struct (u32) */
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#define CEPH_ENCODING_START_BLK_LEN 6
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/**
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* ceph_start_encoding - start encoding block
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* @struct_v: current (code) version of the encoding
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* @struct_compat: oldest code version that can decode it
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* @struct_len: length of struct encoding
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*/
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static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat,
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u32 struct_len)
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{
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ceph_encode_8(p, struct_v);
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ceph_encode_8(p, struct_compat);
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ceph_encode_32(p, struct_len);
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}
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/**
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* ceph_start_decoding - start decoding block
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* @v: current version of the encoding that the code supports
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* @name: name of the struct (free-form)
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* @struct_v: out param for the encoding version
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* @struct_len: out param for the length of struct encoding
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*
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* Validates the length of struct encoding, so unsafe ceph_decode_*
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* variants can be used for decoding.
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*/
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static inline int ceph_start_decoding(void **p, void *end, u8 v,
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const char *name, u8 *struct_v,
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u32 *struct_len)
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{
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u8 struct_compat;
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ceph_decode_need(p, end, CEPH_ENCODING_START_BLK_LEN, bad);
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*struct_v = ceph_decode_8(p);
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struct_compat = ceph_decode_8(p);
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if (v < struct_compat) {
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pr_warn("got struct_v %d struct_compat %d > %d of %s\n",
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*struct_v, struct_compat, v, name);
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return -EINVAL;
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}
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*struct_len = ceph_decode_32(p);
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ceph_decode_need(p, end, *struct_len, bad);
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return 0;
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bad:
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return -ERANGE;
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}
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#define ceph_encode_need(p, end, n, bad) \
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do { \
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if (!likely(ceph_has_room(p, end, n))) \
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goto bad; \
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} while (0)
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#define ceph_encode_64_safe(p, end, v, bad) \
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do { \
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ceph_encode_need(p, end, sizeof(u64), bad); \
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ceph_encode_64(p, v); \
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} while (0)
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#define ceph_encode_32_safe(p, end, v, bad) \
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do { \
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ceph_encode_need(p, end, sizeof(u32), bad); \
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ceph_encode_32(p, v); \
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} while (0)
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#define ceph_encode_16_safe(p, end, v, bad) \
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do { \
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ceph_encode_need(p, end, sizeof(u16), bad); \
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ceph_encode_16(p, v); \
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} while (0)
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#define ceph_encode_8_safe(p, end, v, bad) \
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do { \
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ceph_encode_need(p, end, sizeof(u8), bad); \
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ceph_encode_8(p, v); \
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} while (0)
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#define ceph_encode_copy_safe(p, end, pv, n, bad) \
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do { \
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ceph_encode_need(p, end, n, bad); \
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ceph_encode_copy(p, pv, n); \
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} while (0)
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#define ceph_encode_string_safe(p, end, s, n, bad) \
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do { \
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ceph_encode_need(p, end, n, bad); \
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ceph_encode_string(p, end, s, n); \
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} while (0)
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#endif
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