1 #ifndef __CEPH_DECODE_H 2 #define __CEPH_DECODE_H 3 4 #include <linux/err.h> 5 #include <linux/bug.h> 6 #include <linux/time.h> 7 #include <asm/unaligned.h> 8 9 #include <linux/ceph/types.h> 10 11 /* This seemed to be the easiest place to define these */ 12 13 #define U8_MAX ((u8)(~0U)) 14 #define U16_MAX ((u16)(~0U)) 15 #define U32_MAX ((u32)(~0U)) 16 #define U64_MAX ((u64)(~0ULL)) 17 18 #define S8_MAX ((s8)(U8_MAX >> 1)) 19 #define S16_MAX ((s16)(U16_MAX >> 1)) 20 #define S32_MAX ((s32)(U32_MAX >> 1)) 21 #define S64_MAX ((s64)(U64_MAX >> 1LL)) 22 23 #define S8_MIN ((s8)(-S8_MAX - 1)) 24 #define S16_MIN ((s16)(-S16_MAX - 1)) 25 #define S32_MIN ((s32)(-S32_MAX - 1)) 26 #define S64_MIN ((s64)(-S64_MAX - 1LL)) 27 28 /* 29 * in all cases, 30 * void **p pointer to position pointer 31 * void *end pointer to end of buffer (last byte + 1) 32 */ 33 34 static inline u64 ceph_decode_64(void **p) 35 { 36 u64 v = get_unaligned_le64(*p); 37 *p += sizeof(u64); 38 return v; 39 } 40 static inline u32 ceph_decode_32(void **p) 41 { 42 u32 v = get_unaligned_le32(*p); 43 *p += sizeof(u32); 44 return v; 45 } 46 static inline u16 ceph_decode_16(void **p) 47 { 48 u16 v = get_unaligned_le16(*p); 49 *p += sizeof(u16); 50 return v; 51 } 52 static inline u8 ceph_decode_8(void **p) 53 { 54 u8 v = *(u8 *)*p; 55 (*p)++; 56 return v; 57 } 58 static inline void ceph_decode_copy(void **p, void *pv, size_t n) 59 { 60 memcpy(pv, *p, n); 61 *p += n; 62 } 63 64 /* 65 * bounds check input. 66 */ 67 static inline int ceph_has_room(void **p, void *end, size_t n) 68 { 69 return end >= *p && n <= end - *p; 70 } 71 72 #define ceph_decode_need(p, end, n, bad) \ 73 do { \ 74 if (!likely(ceph_has_room(p, end, n))) \ 75 goto bad; \ 76 } while (0) 77 78 #define ceph_decode_64_safe(p, end, v, bad) \ 79 do { \ 80 ceph_decode_need(p, end, sizeof(u64), bad); \ 81 v = ceph_decode_64(p); \ 82 } while (0) 83 #define ceph_decode_32_safe(p, end, v, bad) \ 84 do { \ 85 ceph_decode_need(p, end, sizeof(u32), bad); \ 86 v = ceph_decode_32(p); \ 87 } while (0) 88 #define ceph_decode_16_safe(p, end, v, bad) \ 89 do { \ 90 ceph_decode_need(p, end, sizeof(u16), bad); \ 91 v = ceph_decode_16(p); \ 92 } while (0) 93 #define ceph_decode_8_safe(p, end, v, bad) \ 94 do { \ 95 ceph_decode_need(p, end, sizeof(u8), bad); \ 96 v = ceph_decode_8(p); \ 97 } while (0) 98 99 #define ceph_decode_copy_safe(p, end, pv, n, bad) \ 100 do { \ 101 ceph_decode_need(p, end, n, bad); \ 102 ceph_decode_copy(p, pv, n); \ 103 } while (0) 104 105 /* 106 * Allocate a buffer big enough to hold the wire-encoded string, and 107 * decode the string into it. The resulting string will always be 108 * terminated with '\0'. If successful, *p will be advanced 109 * past the decoded data. Also, if lenp is not a null pointer, the 110 * length (not including the terminating '\0') will be recorded in 111 * *lenp. Note that a zero-length string is a valid return value. 112 * 113 * Returns a pointer to the newly-allocated string buffer, or a 114 * pointer-coded errno if an error occurs. Neither *p nor *lenp 115 * will have been updated if an error is returned. 116 * 117 * There are two possible failures: 118 * - converting the string would require accessing memory at or 119 * beyond the "end" pointer provided (-ERANGE) 120 * - memory could not be allocated for the result (-ENOMEM) 121 */ 122 static inline char *ceph_extract_encoded_string(void **p, void *end, 123 size_t *lenp, gfp_t gfp) 124 { 125 u32 len; 126 void *sp = *p; 127 char *buf; 128 129 ceph_decode_32_safe(&sp, end, len, bad); 130 if (!ceph_has_room(&sp, end, len)) 131 goto bad; 132 133 buf = kmalloc(len + 1, gfp); 134 if (!buf) 135 return ERR_PTR(-ENOMEM); 136 137 if (len) 138 memcpy(buf, sp, len); 139 buf[len] = '\0'; 140 141 *p = (char *) *p + sizeof (u32) + len; 142 if (lenp) 143 *lenp = (size_t) len; 144 145 return buf; 146 147 bad: 148 return ERR_PTR(-ERANGE); 149 } 150 151 /* 152 * struct ceph_timespec <-> struct timespec 153 */ 154 static inline void ceph_decode_timespec(struct timespec *ts, 155 const struct ceph_timespec *tv) 156 { 157 ts->tv_sec = (__kernel_time_t)le32_to_cpu(tv->tv_sec); 158 ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec); 159 } 160 static inline void ceph_encode_timespec(struct ceph_timespec *tv, 161 const struct timespec *ts) 162 { 163 BUG_ON(ts->tv_sec < 0); 164 BUG_ON(ts->tv_sec > (__kernel_time_t)U32_MAX); 165 BUG_ON(ts->tv_nsec < 0); 166 BUG_ON(ts->tv_nsec > (long)U32_MAX); 167 168 tv->tv_sec = cpu_to_le32((u32)ts->tv_sec); 169 tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec); 170 } 171 172 /* 173 * sockaddr_storage <-> ceph_sockaddr 174 */ 175 static inline void ceph_encode_addr(struct ceph_entity_addr *a) 176 { 177 __be16 ss_family = htons(a->in_addr.ss_family); 178 a->in_addr.ss_family = *(__u16 *)&ss_family; 179 } 180 static inline void ceph_decode_addr(struct ceph_entity_addr *a) 181 { 182 __be16 ss_family = *(__be16 *)&a->in_addr.ss_family; 183 a->in_addr.ss_family = ntohs(ss_family); 184 WARN_ON(a->in_addr.ss_family == 512); 185 } 186 187 /* 188 * encoders 189 */ 190 static inline void ceph_encode_64(void **p, u64 v) 191 { 192 put_unaligned_le64(v, (__le64 *)*p); 193 *p += sizeof(u64); 194 } 195 static inline void ceph_encode_32(void **p, u32 v) 196 { 197 put_unaligned_le32(v, (__le32 *)*p); 198 *p += sizeof(u32); 199 } 200 static inline void ceph_encode_16(void **p, u16 v) 201 { 202 put_unaligned_le16(v, (__le16 *)*p); 203 *p += sizeof(u16); 204 } 205 static inline void ceph_encode_8(void **p, u8 v) 206 { 207 *(u8 *)*p = v; 208 (*p)++; 209 } 210 static inline void ceph_encode_copy(void **p, const void *s, int len) 211 { 212 memcpy(*p, s, len); 213 *p += len; 214 } 215 216 /* 217 * filepath, string encoders 218 */ 219 static inline void ceph_encode_filepath(void **p, void *end, 220 u64 ino, const char *path) 221 { 222 u32 len = path ? strlen(path) : 0; 223 BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end); 224 ceph_encode_8(p, 1); 225 ceph_encode_64(p, ino); 226 ceph_encode_32(p, len); 227 if (len) 228 memcpy(*p, path, len); 229 *p += len; 230 } 231 232 static inline void ceph_encode_string(void **p, void *end, 233 const char *s, u32 len) 234 { 235 BUG_ON(*p + sizeof(len) + len > end); 236 ceph_encode_32(p, len); 237 if (len) 238 memcpy(*p, s, len); 239 *p += len; 240 } 241 242 #define ceph_encode_need(p, end, n, bad) \ 243 do { \ 244 if (!likely(ceph_has_room(p, end, n))) \ 245 goto bad; \ 246 } while (0) 247 248 #define ceph_encode_64_safe(p, end, v, bad) \ 249 do { \ 250 ceph_encode_need(p, end, sizeof(u64), bad); \ 251 ceph_encode_64(p, v); \ 252 } while (0) 253 #define ceph_encode_32_safe(p, end, v, bad) \ 254 do { \ 255 ceph_encode_need(p, end, sizeof(u32), bad); \ 256 ceph_encode_32(p, v); \ 257 } while (0) 258 #define ceph_encode_16_safe(p, end, v, bad) \ 259 do { \ 260 ceph_encode_need(p, end, sizeof(u16), bad); \ 261 ceph_encode_16(p, v); \ 262 } while (0) 263 #define ceph_encode_8_safe(p, end, v, bad) \ 264 do { \ 265 ceph_encode_need(p, end, sizeof(u8), bad); \ 266 ceph_encode_8(p, v); \ 267 } while (0) 268 269 #define ceph_encode_copy_safe(p, end, pv, n, bad) \ 270 do { \ 271 ceph_encode_need(p, end, n, bad); \ 272 ceph_encode_copy(p, pv, n); \ 273 } while (0) 274 #define ceph_encode_string_safe(p, end, s, n, bad) \ 275 do { \ 276 ceph_encode_need(p, end, n, bad); \ 277 ceph_encode_string(p, end, s, n); \ 278 } while (0) 279 280 281 #endif 282