1 #ifndef __CEPH_DECODE_H
2 #define __CEPH_DECODE_H
6 #include <linux/slab.h>
7 #include <linux/time.h>
8 #include <asm/unaligned.h>
10 #include <linux/ceph/types.h>
14 * void **p pointer to position pointer
15 * void *end pointer to end of buffer (last byte + 1)
18 static inline u64 ceph_decode_64(void **p)
20 u64 v = get_unaligned_le64(*p);
24 static inline u32 ceph_decode_32(void **p)
26 u32 v = get_unaligned_le32(*p);
30 static inline u16 ceph_decode_16(void **p)
32 u16 v = get_unaligned_le16(*p);
36 static inline u8 ceph_decode_8(void **p)
42 static inline void ceph_decode_copy(void **p, void *pv, size_t n)
51 static inline bool ceph_has_room(void **p, void *end, size_t n)
53 return end >= *p && n <= end - *p;
56 #define ceph_decode_need(p, end, n, bad) \
58 if (!likely(ceph_has_room(p, end, n))) \
62 #define ceph_decode_64_safe(p, end, v, bad) \
64 ceph_decode_need(p, end, sizeof(u64), bad); \
65 v = ceph_decode_64(p); \
67 #define ceph_decode_32_safe(p, end, v, bad) \
69 ceph_decode_need(p, end, sizeof(u32), bad); \
70 v = ceph_decode_32(p); \
72 #define ceph_decode_16_safe(p, end, v, bad) \
74 ceph_decode_need(p, end, sizeof(u16), bad); \
75 v = ceph_decode_16(p); \
77 #define ceph_decode_8_safe(p, end, v, bad) \
79 ceph_decode_need(p, end, sizeof(u8), bad); \
80 v = ceph_decode_8(p); \
83 #define ceph_decode_copy_safe(p, end, pv, n, bad) \
85 ceph_decode_need(p, end, n, bad); \
86 ceph_decode_copy(p, pv, n); \
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.
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.
101 * There are two possible failures:
102 * - converting the string would require accessing memory at or
103 * beyond the "end" pointer provided (-ERANGE)
104 * - memory could not be allocated for the result (-ENOMEM)
106 static inline char *ceph_extract_encoded_string(void **p, void *end,
107 size_t *lenp, gfp_t gfp)
113 ceph_decode_32_safe(&sp, end, len, bad);
114 if (!ceph_has_room(&sp, end, len))
117 buf = kmalloc(len + 1, gfp);
119 return ERR_PTR(-ENOMEM);
122 memcpy(buf, sp, len);
125 *p = (char *) *p + sizeof (u32) + len;
127 *lenp = (size_t) len;
132 return ERR_PTR(-ERANGE);
136 * struct ceph_timespec <-> struct timespec
138 static inline void ceph_decode_timespec(struct timespec *ts,
139 const struct ceph_timespec *tv)
141 ts->tv_sec = (__kernel_time_t)le32_to_cpu(tv->tv_sec);
142 ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec);
144 static inline void ceph_encode_timespec(struct ceph_timespec *tv,
145 const struct timespec *ts)
147 tv->tv_sec = cpu_to_le32((u32)ts->tv_sec);
148 tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec);
152 * sockaddr_storage <-> ceph_sockaddr
154 static inline void ceph_encode_addr(struct ceph_entity_addr *a)
156 __be16 ss_family = htons(a->in_addr.ss_family);
157 a->in_addr.ss_family = *(__u16 *)&ss_family;
159 static inline void ceph_decode_addr(struct ceph_entity_addr *a)
161 __be16 ss_family = *(__be16 *)&a->in_addr.ss_family;
162 a->in_addr.ss_family = ntohs(ss_family);
163 WARN_ON(a->in_addr.ss_family == 512);
169 static inline void ceph_encode_64(void **p, u64 v)
171 put_unaligned_le64(v, (__le64 *)*p);
174 static inline void ceph_encode_32(void **p, u32 v)
176 put_unaligned_le32(v, (__le32 *)*p);
179 static inline void ceph_encode_16(void **p, u16 v)
181 put_unaligned_le16(v, (__le16 *)*p);
184 static inline void ceph_encode_8(void **p, u8 v)
189 static inline void ceph_encode_copy(void **p, const void *s, int len)
196 * filepath, string encoders
198 static inline void ceph_encode_filepath(void **p, void *end,
199 u64 ino, const char *path)
201 u32 len = path ? strlen(path) : 0;
202 BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end);
204 ceph_encode_64(p, ino);
205 ceph_encode_32(p, len);
207 memcpy(*p, path, len);
211 static inline void ceph_encode_string(void **p, void *end,
212 const char *s, u32 len)
214 BUG_ON(*p + sizeof(len) + len > end);
215 ceph_encode_32(p, len);
222 * version and length starting block encoders/decoders
225 /* current code version (u8) + compat code version (u8) + len of struct (u32) */
226 #define CEPH_ENCODING_START_BLK_LEN 6
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
234 static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat,
237 ceph_encode_8(p, struct_v);
238 ceph_encode_8(p, struct_compat);
239 ceph_encode_32(p, struct_len);
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
249 * Validates the length of struct encoding, so unsafe ceph_decode_*
250 * variants can be used for decoding.
252 static inline int ceph_start_decoding(void **p, void *end, u8 v,
253 const char *name, u8 *struct_v,
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);
267 *struct_len = ceph_decode_32(p);
268 ceph_decode_need(p, end, *struct_len, bad);
275 #define ceph_encode_need(p, end, n, bad) \
277 if (!likely(ceph_has_room(p, end, n))) \
281 #define ceph_encode_64_safe(p, end, v, bad) \
283 ceph_encode_need(p, end, sizeof(u64), bad); \
284 ceph_encode_64(p, v); \
286 #define ceph_encode_32_safe(p, end, v, bad) \
288 ceph_encode_need(p, end, sizeof(u32), bad); \
289 ceph_encode_32(p, v); \
291 #define ceph_encode_16_safe(p, end, v, bad) \
293 ceph_encode_need(p, end, sizeof(u16), bad); \
294 ceph_encode_16(p, v); \
296 #define ceph_encode_8_safe(p, end, v, bad) \
298 ceph_encode_need(p, end, sizeof(u8), bad); \
299 ceph_encode_8(p, v); \
302 #define ceph_encode_copy_safe(p, end, pv, n, bad) \
304 ceph_encode_need(p, end, n, bad); \
305 ceph_encode_copy(p, pv, n); \
307 #define ceph_encode_string_safe(p, end, s, n, bad) \
309 ceph_encode_need(p, end, n, bad); \
310 ceph_encode_string(p, end, s, n); \