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