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 }
 102
 103 /*
 104  * encoders
 105  */
 106 static inline void ceph_encode_64(void **p, u64 v)
 107 {
 108         put_unaligned_le64(v, (__le64 *)*p);
 109         *p += sizeof(u64);
 110 }
 111 static inline void ceph_encode_32(void **p, u32 v)
 112 {
 113         put_unaligned_le32(v, (__le32 *)*p);
 114         *p += sizeof(u32);
 115 }
 116 static inline void ceph_encode_16(void **p, u16 v)
 117 {
 118         put_unaligned_le16(v, (__le16 *)*p);
 119         *p += sizeof(u16);
 120 }
 121 static inline void ceph_encode_8(void **p, u8 v)
 122 {
 123         *(u8 *)*p = v;
 124         (*p)++;
 125 }
 126
 127 /*
 128  * filepath, string encoders
 129  */
 130 static inline void ceph_encode_filepath(void **p, void *end,
 131                                         u64 ino, const char *path)
 132 {
 133         u32 len = path ? strlen(path) : 0;
 134         BUG_ON(*p + sizeof(ino) + sizeof(len) + len > end);
 135         ceph_encode_64(p, ino);
 136         ceph_encode_32(p, len);
 137         if (len)
 138                 memcpy(*p, path, len);
 139         *p += len;
 140 }
 141
 142 static inline void ceph_encode_string(void **p, void *end,
 143                                       const char *s, u32 len)
 144 {
 145         BUG_ON(*p + sizeof(len) + len > end);
 146         ceph_encode_32(p, len);
 147         if (len)
 148                 memcpy(*p, s, len);
 149         *p += len;
 150 }
 151
 152
 153 #endif