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 <asm/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 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 } 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 } 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 } 37 static inline u8 ceph_decode_8(void **p) 38 { 39 u8 v = *(u8 *)*p; 40 (*p)++; 41 return v; 42 } 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 */ 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 */ 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 */ 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 } 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) 223 224 static inline void ceph_encode_banner_addr(struct ceph_entity_addr *a) 225 { 226 __be16 ss_family = htons(a->in_addr.ss_family); 227 a->in_addr.ss_family = *(__u16 *)&ss_family; 228 229 /* Banner addresses require TYPE_NONE */ 230 a->type = CEPH_ENTITY_ADDR_TYPE_NONE; 231 } 232 static inline void ceph_decode_banner_addr(struct ceph_entity_addr *a) 233 { 234 __be16 ss_family = *(__be16 *)&a->in_addr.ss_family; 235 a->in_addr.ss_family = ntohs(ss_family); 236 WARN_ON(a->in_addr.ss_family == 512); 237 a->type = CEPH_ENTITY_ADDR_TYPE_LEGACY; 238 } 239 240 extern int ceph_decode_entity_addr(void **p, void *end, 241 struct ceph_entity_addr *addr); 242 /* 243 * encoders 244 */ 245 static inline void ceph_encode_64(void **p, u64 v) 246 { 247 put_unaligned_le64(v, (__le64 *)*p); 248 *p += sizeof(u64); 249 } 250 static inline void ceph_encode_32(void **p, u32 v) 251 { 252 put_unaligned_le32(v, (__le32 *)*p); 253 *p += sizeof(u32); 254 } 255 static inline void ceph_encode_16(void **p, u16 v) 256 { 257 put_unaligned_le16(v, (__le16 *)*p); 258 *p += sizeof(u16); 259 } 260 static inline void ceph_encode_8(void **p, u8 v) 261 { 262 *(u8 *)*p = v; 263 (*p)++; 264 } 265 static inline void ceph_encode_copy(void **p, const void *s, int len) 266 { 267 memcpy(*p, s, len); 268 *p += len; 269 } 270 271 /* 272 * filepath, string encoders 273 */ 274 static inline void ceph_encode_filepath(void **p, void *end, 275 u64 ino, const char *path) 276 { 277 u32 len = path ? strlen(path) : 0; 278 BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end); 279 ceph_encode_8(p, 1); 280 ceph_encode_64(p, ino); 281 ceph_encode_32(p, len); 282 if (len) 283 memcpy(*p, path, len); 284 *p += len; 285 } 286 287 static inline void ceph_encode_string(void **p, void *end, 288 const char *s, u32 len) 289 { 290 BUG_ON(*p + sizeof(len) + len > end); 291 ceph_encode_32(p, len); 292 if (len) 293 memcpy(*p, s, len); 294 *p += len; 295 } 296 297 /* 298 * version and length starting block encoders/decoders 299 */ 300 301 /* current code version (u8) + compat code version (u8) + len of struct (u32) */ 302 #define CEPH_ENCODING_START_BLK_LEN 6 303 304 /** 305 * ceph_start_encoding - start encoding block 306 * @struct_v: current (code) version of the encoding 307 * @struct_compat: oldest code version that can decode it 308 * @struct_len: length of struct encoding 309 */ 310 static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat, 311 u32 struct_len) 312 { 313 ceph_encode_8(p, struct_v); 314 ceph_encode_8(p, struct_compat); 315 ceph_encode_32(p, struct_len); 316 } 317 318 /** 319 * ceph_start_decoding - start decoding block 320 * @v: current version of the encoding that the code supports 321 * @name: name of the struct (free-form) 322 * @struct_v: out param for the encoding version 323 * @struct_len: out param for the length of struct encoding 324 * 325 * Validates the length of struct encoding, so unsafe ceph_decode_* 326 * variants can be used for decoding. 327 */ 328 static inline int ceph_start_decoding(void **p, void *end, u8 v, 329 const char *name, u8 *struct_v, 330 u32 *struct_len) 331 { 332 u8 struct_compat; 333 334 ceph_decode_need(p, end, CEPH_ENCODING_START_BLK_LEN, bad); 335 *struct_v = ceph_decode_8(p); 336 struct_compat = ceph_decode_8(p); 337 if (v < struct_compat) { 338 pr_warn("got struct_v %d struct_compat %d > %d of %s\n", 339 *struct_v, struct_compat, v, name); 340 return -EINVAL; 341 } 342 343 *struct_len = ceph_decode_32(p); 344 ceph_decode_need(p, end, *struct_len, bad); 345 return 0; 346 347 bad: 348 return -ERANGE; 349 } 350 351 #define ceph_encode_need(p, end, n, bad) \ 352 do { \ 353 if (!likely(ceph_has_room(p, end, n))) \ 354 goto bad; \ 355 } while (0) 356 357 #define ceph_encode_64_safe(p, end, v, bad) \ 358 do { \ 359 ceph_encode_need(p, end, sizeof(u64), bad); \ 360 ceph_encode_64(p, v); \ 361 } while (0) 362 #define ceph_encode_32_safe(p, end, v, bad) \ 363 do { \ 364 ceph_encode_need(p, end, sizeof(u32), bad); \ 365 ceph_encode_32(p, v); \ 366 } while (0) 367 #define ceph_encode_16_safe(p, end, v, bad) \ 368 do { \ 369 ceph_encode_need(p, end, sizeof(u16), bad); \ 370 ceph_encode_16(p, v); \ 371 } while (0) 372 #define ceph_encode_8_safe(p, end, v, bad) \ 373 do { \ 374 ceph_encode_need(p, end, sizeof(u8), bad); \ 375 ceph_encode_8(p, v); \ 376 } while (0) 377 378 #define ceph_encode_copy_safe(p, end, pv, n, bad) \ 379 do { \ 380 ceph_encode_need(p, end, n, bad); \ 381 ceph_encode_copy(p, pv, n); \ 382 } while (0) 383 #define ceph_encode_string_safe(p, end, s, n, bad) \ 384 do { \ 385 ceph_encode_need(p, end, n, bad); \ 386 ceph_encode_string(p, end, s, n); \ 387 } while (0) 388 389 390 #endif 391