1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __CEPH_DECODE_H 3 #define __CEPH_DECODE_H 4 5 #include <linux/err.h> 6 #include <linux/bug.h> 7 #include <linux/slab.h> 8 #include <linux/time.h> 9 #include <linux/unaligned.h> 10 11 #include <linux/ceph/types.h> 12 13 /* 14 * in all cases, 15 * void **p pointer to position pointer 16 * void *end pointer to end of buffer (last byte + 1) 17 */ 18 ceph_decode_64(void ** p)19 static inline u64 ceph_decode_64(void **p) 20 { 21 u64 v = get_unaligned_le64(*p); 22 *p += sizeof(u64); 23 return v; 24 } ceph_decode_32(void ** p)25 static inline u32 ceph_decode_32(void **p) 26 { 27 u32 v = get_unaligned_le32(*p); 28 *p += sizeof(u32); 29 return v; 30 } ceph_decode_16(void ** p)31 static inline u16 ceph_decode_16(void **p) 32 { 33 u16 v = get_unaligned_le16(*p); 34 *p += sizeof(u16); 35 return v; 36 } ceph_decode_8(void ** p)37 static inline u8 ceph_decode_8(void **p) 38 { 39 u8 v = *(u8 *)*p; 40 (*p)++; 41 return v; 42 } ceph_decode_copy(void ** p,void * pv,size_t n)43 static inline void ceph_decode_copy(void **p, void *pv, size_t n) 44 { 45 memcpy(pv, *p, n); 46 *p += n; 47 } 48 49 /* 50 * bounds check input. 51 */ ceph_has_room(void ** p,void * end,size_t n)52 static inline bool ceph_has_room(void **p, void *end, size_t n) 53 { 54 return end >= *p && n <= end - *p; 55 } 56 57 #define ceph_decode_need(p, end, n, bad) \ 58 do { \ 59 if (!likely(ceph_has_room(p, end, n))) \ 60 goto bad; \ 61 } while (0) 62 63 #define ceph_decode_64_safe(p, end, v, bad) \ 64 do { \ 65 ceph_decode_need(p, end, sizeof(u64), bad); \ 66 v = ceph_decode_64(p); \ 67 } while (0) 68 #define ceph_decode_32_safe(p, end, v, bad) \ 69 do { \ 70 ceph_decode_need(p, end, sizeof(u32), bad); \ 71 v = ceph_decode_32(p); \ 72 } while (0) 73 #define ceph_decode_16_safe(p, end, v, bad) \ 74 do { \ 75 ceph_decode_need(p, end, sizeof(u16), bad); \ 76 v = ceph_decode_16(p); \ 77 } while (0) 78 #define ceph_decode_8_safe(p, end, v, bad) \ 79 do { \ 80 ceph_decode_need(p, end, sizeof(u8), bad); \ 81 v = ceph_decode_8(p); \ 82 } while (0) 83 84 #define ceph_decode_copy_safe(p, end, pv, n, bad) \ 85 do { \ 86 ceph_decode_need(p, end, n, bad); \ 87 ceph_decode_copy(p, pv, n); \ 88 } while (0) 89 90 /* 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. 97 * 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. 101 * 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) 106 */ ceph_extract_encoded_string(void ** p,void * end,size_t * lenp,gfp_t gfp)107 static inline char *ceph_extract_encoded_string(void **p, void *end, 108 size_t *lenp, gfp_t gfp) 109 { 110 u32 len; 111 void *sp = *p; 112 char *buf; 113 114 ceph_decode_32_safe(&sp, end, len, bad); 115 if (!ceph_has_room(&sp, end, len)) 116 goto bad; 117 118 buf = kmalloc(len + 1, gfp); 119 if (!buf) 120 return ERR_PTR(-ENOMEM); 121 122 if (len) 123 memcpy(buf, sp, len); 124 buf[len] = '\0'; 125 126 *p = (char *) *p + sizeof (u32) + len; 127 if (lenp) 128 *lenp = (size_t) len; 129 130 return buf; 131 132 bad: 133 return ERR_PTR(-ERANGE); 134 } 135 136 /* 137 * skip helpers 138 */ 139 #define ceph_decode_skip_n(p, end, n, bad) \ 140 do { \ 141 ceph_decode_need(p, end, n, bad); \ 142 *p += n; \ 143 } while (0) 144 145 #define ceph_decode_skip_64(p, end, bad) \ 146 ceph_decode_skip_n(p, end, sizeof(u64), bad) 147 148 #define ceph_decode_skip_32(p, end, bad) \ 149 ceph_decode_skip_n(p, end, sizeof(u32), bad) 150 151 #define ceph_decode_skip_16(p, end, bad) \ 152 ceph_decode_skip_n(p, end, sizeof(u16), bad) 153 154 #define ceph_decode_skip_8(p, end, bad) \ 155 ceph_decode_skip_n(p, end, sizeof(u8), bad) 156 157 #define ceph_decode_skip_string(p, end, bad) \ 158 do { \ 159 u32 len; \ 160 \ 161 ceph_decode_32_safe(p, end, len, bad); \ 162 ceph_decode_skip_n(p, end, len, bad); \ 163 } while (0) 164 165 #define ceph_decode_skip_set(p, end, type, bad) \ 166 do { \ 167 u32 len; \ 168 \ 169 ceph_decode_32_safe(p, end, len, bad); \ 170 while (len--) \ 171 ceph_decode_skip_##type(p, end, bad); \ 172 } while (0) 173 174 #define ceph_decode_skip_map(p, end, ktype, vtype, bad) \ 175 do { \ 176 u32 len; \ 177 \ 178 ceph_decode_32_safe(p, end, len, bad); \ 179 while (len--) { \ 180 ceph_decode_skip_##ktype(p, end, bad); \ 181 ceph_decode_skip_##vtype(p, end, bad); \ 182 } \ 183 } while (0) 184 185 #define ceph_decode_skip_map_of_map(p, end, ktype1, ktype2, vtype2, bad) \ 186 do { \ 187 u32 len; \ 188 \ 189 ceph_decode_32_safe(p, end, len, bad); \ 190 while (len--) { \ 191 ceph_decode_skip_##ktype1(p, end, bad); \ 192 ceph_decode_skip_map(p, end, ktype2, vtype2, bad); \ 193 } \ 194 } while (0) 195 196 /* 197 * struct ceph_timespec <-> struct timespec64 198 */ ceph_decode_timespec64(struct timespec64 * ts,const struct ceph_timespec * tv)199 static inline void ceph_decode_timespec64(struct timespec64 *ts, 200 const struct ceph_timespec *tv) 201 { 202 /* 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 206 * does if necessary. 207 */ 208 ts->tv_sec = (time64_t)le32_to_cpu(tv->tv_sec); 209 ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec); 210 } ceph_encode_timespec64(struct ceph_timespec * tv,const struct timespec64 * ts)211 static inline void ceph_encode_timespec64(struct ceph_timespec *tv, 212 const struct timespec64 *ts) 213 { 214 tv->tv_sec = cpu_to_le32((u32)ts->tv_sec); 215 tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec); 216 } 217 218 /* 219 * sockaddr_storage <-> ceph_sockaddr 220 */ 221 #define CEPH_ENTITY_ADDR_TYPE_NONE 0 222 #define CEPH_ENTITY_ADDR_TYPE_LEGACY __cpu_to_le32(1) 223 #define CEPH_ENTITY_ADDR_TYPE_MSGR2 __cpu_to_le32(2) 224 #define CEPH_ENTITY_ADDR_TYPE_ANY __cpu_to_le32(3) 225 ceph_encode_banner_addr(struct ceph_entity_addr * a)226 static inline void ceph_encode_banner_addr(struct ceph_entity_addr *a) 227 { 228 __be16 ss_family = htons(a->in_addr.ss_family); 229 a->in_addr.ss_family = *(__u16 *)&ss_family; 230 231 /* Banner addresses require TYPE_NONE */ 232 a->type = CEPH_ENTITY_ADDR_TYPE_NONE; 233 } ceph_decode_banner_addr(struct ceph_entity_addr * a)234 static inline void ceph_decode_banner_addr(struct ceph_entity_addr *a) 235 { 236 __be16 ss_family = *(__be16 *)&a->in_addr.ss_family; 237 a->in_addr.ss_family = ntohs(ss_family); 238 WARN_ON(a->in_addr.ss_family == 512); 239 a->type = CEPH_ENTITY_ADDR_TYPE_LEGACY; 240 } 241 242 extern int ceph_decode_entity_addr(void **p, void *end, 243 struct ceph_entity_addr *addr); 244 int ceph_decode_entity_addrvec(void **p, void *end, bool msgr2, 245 struct ceph_entity_addr *addr); 246 247 int ceph_entity_addr_encoding_len(const struct ceph_entity_addr *addr); 248 void ceph_encode_entity_addr(void **p, const struct ceph_entity_addr *addr); 249 250 /* 251 * encoders 252 */ ceph_encode_64(void ** p,u64 v)253 static inline void ceph_encode_64(void **p, u64 v) 254 { 255 put_unaligned_le64(v, (__le64 *)*p); 256 *p += sizeof(u64); 257 } ceph_encode_32(void ** p,u32 v)258 static inline void ceph_encode_32(void **p, u32 v) 259 { 260 put_unaligned_le32(v, (__le32 *)*p); 261 *p += sizeof(u32); 262 } ceph_encode_16(void ** p,u16 v)263 static inline void ceph_encode_16(void **p, u16 v) 264 { 265 put_unaligned_le16(v, (__le16 *)*p); 266 *p += sizeof(u16); 267 } ceph_encode_8(void ** p,u8 v)268 static inline void ceph_encode_8(void **p, u8 v) 269 { 270 *(u8 *)*p = v; 271 (*p)++; 272 } ceph_encode_copy(void ** p,const void * s,int len)273 static inline void ceph_encode_copy(void **p, const void *s, int len) 274 { 275 memcpy(*p, s, len); 276 *p += len; 277 } 278 279 /* 280 * filepath, string encoders 281 */ ceph_encode_filepath(void ** p,void * end,u64 ino,const char * path)282 static inline void ceph_encode_filepath(void **p, void *end, 283 u64 ino, const char *path) 284 { 285 u32 len = path ? strlen(path) : 0; 286 BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end); 287 ceph_encode_8(p, 1); 288 ceph_encode_64(p, ino); 289 ceph_encode_32(p, len); 290 if (len) 291 memcpy(*p, path, len); 292 *p += len; 293 } 294 ceph_encode_string(void ** p,void * end,const char * s,u32 len)295 static inline void ceph_encode_string(void **p, void *end, 296 const char *s, u32 len) 297 { 298 BUG_ON(*p + sizeof(len) + len > end); 299 ceph_encode_32(p, len); 300 if (len) 301 memcpy(*p, s, len); 302 *p += len; 303 } 304 305 /* 306 * version and length starting block encoders/decoders 307 */ 308 309 /* current code version (u8) + compat code version (u8) + len of struct (u32) */ 310 #define CEPH_ENCODING_START_BLK_LEN 6 311 312 /** 313 * ceph_start_encoding - start encoding block 314 * @struct_v: current (code) version of the encoding 315 * @struct_compat: oldest code version that can decode it 316 * @struct_len: length of struct encoding 317 */ ceph_start_encoding(void ** p,u8 struct_v,u8 struct_compat,u32 struct_len)318 static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat, 319 u32 struct_len) 320 { 321 ceph_encode_8(p, struct_v); 322 ceph_encode_8(p, struct_compat); 323 ceph_encode_32(p, struct_len); 324 } 325 326 /** 327 * ceph_start_decoding - start decoding block 328 * @v: current version of the encoding that the code supports 329 * @name: name of the struct (free-form) 330 * @struct_v: out param for the encoding version 331 * @struct_len: out param for the length of struct encoding 332 * 333 * Validates the length of struct encoding, so unsafe ceph_decode_* 334 * variants can be used for decoding. 335 */ ceph_start_decoding(void ** p,void * end,u8 v,const char * name,u8 * struct_v,u32 * struct_len)336 static inline int ceph_start_decoding(void **p, void *end, u8 v, 337 const char *name, u8 *struct_v, 338 u32 *struct_len) 339 { 340 u8 struct_compat; 341 342 ceph_decode_need(p, end, CEPH_ENCODING_START_BLK_LEN, bad); 343 *struct_v = ceph_decode_8(p); 344 struct_compat = ceph_decode_8(p); 345 if (v < struct_compat) { 346 pr_warn("got struct_v %d struct_compat %d > %d of %s\n", 347 *struct_v, struct_compat, v, name); 348 return -EINVAL; 349 } 350 351 *struct_len = ceph_decode_32(p); 352 ceph_decode_need(p, end, *struct_len, bad); 353 return 0; 354 355 bad: 356 return -ERANGE; 357 } 358 359 #define ceph_encode_need(p, end, n, bad) \ 360 do { \ 361 if (!likely(ceph_has_room(p, end, n))) \ 362 goto bad; \ 363 } while (0) 364 365 #define ceph_encode_64_safe(p, end, v, bad) \ 366 do { \ 367 ceph_encode_need(p, end, sizeof(u64), bad); \ 368 ceph_encode_64(p, v); \ 369 } while (0) 370 #define ceph_encode_32_safe(p, end, v, bad) \ 371 do { \ 372 ceph_encode_need(p, end, sizeof(u32), bad); \ 373 ceph_encode_32(p, v); \ 374 } while (0) 375 #define ceph_encode_16_safe(p, end, v, bad) \ 376 do { \ 377 ceph_encode_need(p, end, sizeof(u16), bad); \ 378 ceph_encode_16(p, v); \ 379 } while (0) 380 #define ceph_encode_8_safe(p, end, v, bad) \ 381 do { \ 382 ceph_encode_need(p, end, sizeof(u8), bad); \ 383 ceph_encode_8(p, v); \ 384 } while (0) 385 386 #define ceph_encode_copy_safe(p, end, pv, n, bad) \ 387 do { \ 388 ceph_encode_need(p, end, n, bad); \ 389 ceph_encode_copy(p, pv, n); \ 390 } while (0) 391 #define ceph_encode_string_safe(p, end, s, n, bad) \ 392 do { \ 393 ceph_encode_need(p, end, n, bad); \ 394 ceph_encode_string(p, end, s, n); \ 395 } while (0) 396 397 398 #endif 399