1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __CEPH_DECODE_H
3 #define __CEPH_DECODE_H
7 #include <linux/slab.h>
8 #include <linux/time.h>
9 #include <asm/unaligned.h>
11 #include <linux/ceph/types.h>
15 * void **p pointer to position pointer
16 * void *end pointer to end of buffer (last byte + 1)
19 static inline u64 ceph_decode_64(void **p)
21 u64 v = get_unaligned_le64(*p);
25 static inline u32 ceph_decode_32(void **p)
27 u32 v = get_unaligned_le32(*p);
31 static inline u16 ceph_decode_16(void **p)
33 u16 v = get_unaligned_le16(*p);
37 static inline u8 ceph_decode_8(void **p)
43 static inline void ceph_decode_copy(void **p, void *pv, size_t n)
52 static inline bool ceph_has_room(void **p, void *end, size_t n)
54 return end >= *p && n <= end - *p;
57 #define ceph_decode_need(p, end, n, bad) \
59 if (!likely(ceph_has_room(p, end, n))) \
63 #define ceph_decode_64_safe(p, end, v, bad) \
65 ceph_decode_need(p, end, sizeof(u64), bad); \
66 v = ceph_decode_64(p); \
68 #define ceph_decode_32_safe(p, end, v, bad) \
70 ceph_decode_need(p, end, sizeof(u32), bad); \
71 v = ceph_decode_32(p); \
73 #define ceph_decode_16_safe(p, end, v, bad) \
75 ceph_decode_need(p, end, sizeof(u16), bad); \
76 v = ceph_decode_16(p); \
78 #define ceph_decode_8_safe(p, end, v, bad) \
80 ceph_decode_need(p, end, sizeof(u8), bad); \
81 v = ceph_decode_8(p); \
84 #define ceph_decode_copy_safe(p, end, pv, n, bad) \
86 ceph_decode_need(p, end, n, bad); \
87 ceph_decode_copy(p, pv, n); \
91 * Allocate a buffer big enough to hold the wire-encoded string, and
92 * decode the string into it. The resulting string will always be
93 * terminated with '\0'. If successful, *p will be advanced
94 * past the decoded data. Also, if lenp is not a null pointer, the
95 * length (not including the terminating '\0') will be recorded in
96 * *lenp. Note that a zero-length string is a valid return value.
98 * Returns a pointer to the newly-allocated string buffer, or a
99 * pointer-coded errno if an error occurs. Neither *p nor *lenp
100 * will have been updated if an error is returned.
102 * There are two possible failures:
103 * - converting the string would require accessing memory at or
104 * beyond the "end" pointer provided (-ERANGE)
105 * - memory could not be allocated for the result (-ENOMEM)
107 static inline char *ceph_extract_encoded_string(void **p, void *end,
108 size_t *lenp, gfp_t gfp)
114 ceph_decode_32_safe(&sp, end, len, bad);
115 if (!ceph_has_room(&sp, end, len))
118 buf = kmalloc(len + 1, gfp);
120 return ERR_PTR(-ENOMEM);
123 memcpy(buf, sp, len);
126 *p = (char *) *p + sizeof (u32) + len;
128 *lenp = (size_t) len;
133 return ERR_PTR(-ERANGE);
139 #define ceph_decode_skip_n(p, end, n, bad) \
141 ceph_decode_need(p, end, n, bad); \
145 #define ceph_decode_skip_64(p, end, bad) \
146 ceph_decode_skip_n(p, end, sizeof(u64), bad)
148 #define ceph_decode_skip_32(p, end, bad) \
149 ceph_decode_skip_n(p, end, sizeof(u32), bad)
151 #define ceph_decode_skip_16(p, end, bad) \
152 ceph_decode_skip_n(p, end, sizeof(u16), bad)
154 #define ceph_decode_skip_8(p, end, bad) \
155 ceph_decode_skip_n(p, end, sizeof(u8), bad)
157 #define ceph_decode_skip_string(p, end, bad) \
161 ceph_decode_32_safe(p, end, len, bad); \
162 ceph_decode_skip_n(p, end, len, bad); \
165 #define ceph_decode_skip_set(p, end, type, bad) \
169 ceph_decode_32_safe(p, end, len, bad); \
171 ceph_decode_skip_##type(p, end, bad); \
174 #define ceph_decode_skip_map(p, end, ktype, vtype, bad) \
178 ceph_decode_32_safe(p, end, len, bad); \
180 ceph_decode_skip_##ktype(p, end, bad); \
181 ceph_decode_skip_##vtype(p, end, bad); \
185 #define ceph_decode_skip_map_of_map(p, end, ktype1, ktype2, vtype2, bad) \
189 ceph_decode_32_safe(p, end, len, bad); \
191 ceph_decode_skip_##ktype1(p, end, bad); \
192 ceph_decode_skip_map(p, end, ktype2, vtype2, bad); \
197 * struct ceph_timespec <-> struct timespec64
199 static inline void ceph_decode_timespec64(struct timespec64 *ts,
200 const struct ceph_timespec *tv)
203 * This will still overflow in year 2106. We could extend
204 * the protocol to steal two more bits from tv_nsec to
205 * add three more 136 year epochs after that the way ext4
208 ts->tv_sec = (time64_t)le32_to_cpu(tv->tv_sec);
209 ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec);
211 static inline void ceph_encode_timespec64(struct ceph_timespec *tv,
212 const struct timespec64 *ts)
214 tv->tv_sec = cpu_to_le32((u32)ts->tv_sec);
215 tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec);
219 * sockaddr_storage <-> ceph_sockaddr
221 static inline void ceph_encode_addr(struct ceph_entity_addr *a)
223 __be16 ss_family = htons(a->in_addr.ss_family);
224 a->in_addr.ss_family = *(__u16 *)&ss_family;
226 static inline void ceph_decode_addr(struct ceph_entity_addr *a)
228 __be16 ss_family = *(__be16 *)&a->in_addr.ss_family;
229 a->in_addr.ss_family = ntohs(ss_family);
230 WARN_ON(a->in_addr.ss_family == 512);
236 static inline void ceph_encode_64(void **p, u64 v)
238 put_unaligned_le64(v, (__le64 *)*p);
241 static inline void ceph_encode_32(void **p, u32 v)
243 put_unaligned_le32(v, (__le32 *)*p);
246 static inline void ceph_encode_16(void **p, u16 v)
248 put_unaligned_le16(v, (__le16 *)*p);
251 static inline void ceph_encode_8(void **p, u8 v)
256 static inline void ceph_encode_copy(void **p, const void *s, int len)
263 * filepath, string encoders
265 static inline void ceph_encode_filepath(void **p, void *end,
266 u64 ino, const char *path)
268 u32 len = path ? strlen(path) : 0;
269 BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end);
271 ceph_encode_64(p, ino);
272 ceph_encode_32(p, len);
274 memcpy(*p, path, len);
278 static inline void ceph_encode_string(void **p, void *end,
279 const char *s, u32 len)
281 BUG_ON(*p + sizeof(len) + len > end);
282 ceph_encode_32(p, len);
289 * version and length starting block encoders/decoders
292 /* current code version (u8) + compat code version (u8) + len of struct (u32) */
293 #define CEPH_ENCODING_START_BLK_LEN 6
296 * ceph_start_encoding - start encoding block
297 * @struct_v: current (code) version of the encoding
298 * @struct_compat: oldest code version that can decode it
299 * @struct_len: length of struct encoding
301 static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat,
304 ceph_encode_8(p, struct_v);
305 ceph_encode_8(p, struct_compat);
306 ceph_encode_32(p, struct_len);
310 * ceph_start_decoding - start decoding block
311 * @v: current version of the encoding that the code supports
312 * @name: name of the struct (free-form)
313 * @struct_v: out param for the encoding version
314 * @struct_len: out param for the length of struct encoding
316 * Validates the length of struct encoding, so unsafe ceph_decode_*
317 * variants can be used for decoding.
319 static inline int ceph_start_decoding(void **p, void *end, u8 v,
320 const char *name, u8 *struct_v,
325 ceph_decode_need(p, end, CEPH_ENCODING_START_BLK_LEN, bad);
326 *struct_v = ceph_decode_8(p);
327 struct_compat = ceph_decode_8(p);
328 if (v < struct_compat) {
329 pr_warn("got struct_v %d struct_compat %d > %d of %s\n",
330 *struct_v, struct_compat, v, name);
334 *struct_len = ceph_decode_32(p);
335 ceph_decode_need(p, end, *struct_len, bad);
342 #define ceph_encode_need(p, end, n, bad) \
344 if (!likely(ceph_has_room(p, end, n))) \
348 #define ceph_encode_64_safe(p, end, v, bad) \
350 ceph_encode_need(p, end, sizeof(u64), bad); \
351 ceph_encode_64(p, v); \
353 #define ceph_encode_32_safe(p, end, v, bad) \
355 ceph_encode_need(p, end, sizeof(u32), bad); \
356 ceph_encode_32(p, v); \
358 #define ceph_encode_16_safe(p, end, v, bad) \
360 ceph_encode_need(p, end, sizeof(u16), bad); \
361 ceph_encode_16(p, v); \
363 #define ceph_encode_8_safe(p, end, v, bad) \
365 ceph_encode_need(p, end, sizeof(u8), bad); \
366 ceph_encode_8(p, v); \
369 #define ceph_encode_copy_safe(p, end, pv, n, bad) \
371 ceph_encode_need(p, end, n, bad); \
372 ceph_encode_copy(p, pv, n); \
374 #define ceph_encode_string_safe(p, end, s, n, bad) \
376 ceph_encode_need(p, end, n, bad); \
377 ceph_encode_string(p, end, s, n); \