fs/ceph/decode.h

   1 #ifndef __CEPH_DECODE_H
   2 #define __CEPH_DECODE_H
   3
   4 #include <asm/unaligned.h>
   5
   6 #include "types.h"
   7
   8 /*
   9  * in all cases,
  10  *   void **p     pointer to position pointer
  11  *   void *end    pointer to end of buffer (last byte + 1)
  12  */
  13
  14 static inline u64 ceph_decode_64(void **p)
  15 {
  16         u64 v = get_unaligned_le64(*p);
  17         *p += sizeof(u64);
  18         return v;
  19 }
  20 static inline u32 ceph_decode_32(void **p)
  21 {
  22         u32 v = get_unaligned_le32(*p);
  23         *p += sizeof(u32);
  24         return v;
  25 }
  26 static inline u16 ceph_decode_16(void **p)
  27 {
  28         u16 v = get_unaligned_le16(*p);
  29         *p += sizeof(u16);
  30         return v;
  31 }
  32 static inline u8 ceph_decode_8(void **p)
  33 {
  34         u8 v = *(u8 *)*p;
  35         (*p)++;
  36         return v;
  37 }
  38 static inline void ceph_decode_copy(void **p, void *pv, size_t n)
  39 {
  40         memcpy(pv, *p, n);
  41         *p += n;
  42 }
  43
  44 /*
  45  * bounds check input.
  46  */
  47 #define ceph_decode_need(p, end, n, bad)                \
  48         do {                                            \
  49                 if (unlikely(*(p) + (n) > (end)))       \
  50                         goto bad;                       \
  51         } while (0)
  52
  53 #define ceph_decode_64_safe(p, end, v, bad)                     \
  54         do {                                                    \
  55                 ceph_decode_need(p, end, sizeof(u64), bad);     \
  56                 v = ceph_decode_64(p);                          \
  57         } while (0)
  58 #define ceph_decode_32_safe(p, end, v, bad)                     \
  59         do {                                                    \
  60                 ceph_decode_need(p, end, sizeof(u32), bad);     \
  61                 v = ceph_decode_32(p);                          \
  62         } while (0)
  63 #define ceph_decode_16_safe(p, end, v, bad)                     \
  64         do {                                                    \
  65                 ceph_decode_need(p, end, sizeof(u16), bad);     \
  66                 v = ceph_decode_16(p);                          \
  67         } while (0)
  68
  69 #define ceph_decode_copy_safe(p, end, pv, n, bad)               \
  70         do {                                                    \
  71                 ceph_decode_need(p, end, n, bad);               \
  72                 ceph_decode_copy(p, pv, n);                     \
  73         } while (0)
  74
  75 /*
  76  * struct ceph_timespec <-> struct timespec
  77  */
  78 static inline void ceph_decode_timespec(struct timespec *ts,
  79                                         const struct ceph_timespec *tv)
  80 {
  81         ts->tv_sec = le32_to_cpu(tv->tv_sec);
  82         ts->tv_nsec = le32_to_cpu(tv->tv_nsec);
  83 }
  84 static inline void ceph_encode_timespec(struct ceph_timespec *tv,
  85                                         const struct timespec *ts)
  86 {
  87         tv->tv_sec = cpu_to_le32(ts->tv_sec);
  88         tv->tv_nsec = cpu_to_le32(ts->tv_nsec);
  89 }
  90
  91 /*
  92  * sockaddr_storage <-> ceph_sockaddr
  93  */
  94 static inline void ceph_encode_addr(struct ceph_entity_addr *a)
  95 {
  96         a->in_addr.ss_family = htons(a->in_addr.ss_family);
  97 }
  98 static inline void ceph_decode_addr(struct ceph_entity_addr *a)
  99 {
 100         a->in_addr.ss_family = ntohs(a->in_addr.ss_family);
 101         WARN_ON(a->in_addr.ss_family == 512);
 102 }
 103
 104 /*
 105  * encoders
 106  */
 107 static inline void ceph_encode_64(void **p, u64 v)
 108 {
 109         put_unaligned_le64(v, (__le64 *)*p);
 110         *p += sizeof(u64);
 111 }
 112 static inline void ceph_encode_32(void **p, u32 v)
 113 {
 114         put_unaligned_le32(v, (__le32 *)*p);
 115         *p += sizeof(u32);
 116 }
 117 static inline void ceph_encode_16(void **p, u16 v)
 118 {
 119         put_unaligned_le16(v, (__le16 *)*p);
 120         *p += sizeof(u16);
 121 }
 122 static inline void ceph_encode_8(void **p, u8 v)
 123 {
 124         *(u8 *)*p = v;
 125         (*p)++;
 126 }
 127 static inline void ceph_encode_copy(void **p, const void *s, int len)
 128 {
 129         memcpy(*p, s, len);
 130         *p += len;
 131 }
 132
 133 /*
 134  * filepath, string encoders
 135  */
 136 static inline void ceph_encode_filepath(void **p, void *end,
 137                                         u64 ino, const char *path)
 138 {
 139         u32 len = path ? strlen(path) : 0;
 140         BUG_ON(*p + sizeof(ino) + sizeof(len) + len > end);
 141         ceph_encode_8(p, 1);
 142         ceph_encode_64(p, ino);
 143         ceph_encode_32(p, len);
 144         if (len)
 145                 memcpy(*p, path, len);
 146         *p += len;
 147 }
 148
 149 static inline void ceph_encode_string(void **p, void *end,
 150                                       const char *s, u32 len)
 151 {
 152         BUG_ON(*p + sizeof(len) + len > end);
 153         ceph_encode_32(p, len);
 154         if (len)
 155                 memcpy(*p, s, len);
 156         *p += len;
 157 }
 158
 159
 160 #endif