diff options
Diffstat (limited to 'include/linux/ceph/decode.h')
| -rw-r--r-- | include/linux/ceph/decode.h | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/include/linux/ceph/decode.h b/include/linux/ceph/decode.h new file mode 100644 index 000000000..04f3ace57 --- /dev/null +++ b/include/linux/ceph/decode.h @@ -0,0 +1,398 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __CEPH_DECODE_H +#define __CEPH_DECODE_H + +#include <linux/err.h> +#include <linux/bug.h> +#include <linux/slab.h> +#include <linux/time.h> +#include <asm/unaligned.h> + +#include <linux/ceph/types.h> + +/* + * in all cases, + * void **p pointer to position pointer + * void *end pointer to end of buffer (last byte + 1) + */ + +static inline u64 ceph_decode_64(void **p) +{ + u64 v = get_unaligned_le64(*p); + *p += sizeof(u64); + return v; +} +static inline u32 ceph_decode_32(void **p) +{ + u32 v = get_unaligned_le32(*p); + *p += sizeof(u32); + return v; +} +static inline u16 ceph_decode_16(void **p) +{ + u16 v = get_unaligned_le16(*p); + *p += sizeof(u16); + return v; +} +static inline u8 ceph_decode_8(void **p) +{ + u8 v = *(u8 *)*p; + (*p)++; + return v; +} +static inline void ceph_decode_copy(void **p, void *pv, size_t n) +{ + memcpy(pv, *p, n); + *p += n; +} + +/* + * bounds check input. + */ +static inline bool ceph_has_room(void **p, void *end, size_t n) +{ + return end >= *p && n <= end - *p; +} + +#define ceph_decode_need(p, end, n, bad) \ + do { \ + if (!likely(ceph_has_room(p, end, n))) \ + goto bad; \ + } while (0) + +#define ceph_decode_64_safe(p, end, v, bad) \ + do { \ + ceph_decode_need(p, end, sizeof(u64), bad); \ + v = ceph_decode_64(p); \ + } while (0) +#define ceph_decode_32_safe(p, end, v, bad) \ + do { \ + ceph_decode_need(p, end, sizeof(u32), bad); \ + v = ceph_decode_32(p); \ + } while (0) +#define ceph_decode_16_safe(p, end, v, bad) \ + do { \ + ceph_decode_need(p, end, sizeof(u16), bad); \ + v = ceph_decode_16(p); \ + } while (0) +#define ceph_decode_8_safe(p, end, v, bad) \ + do { \ + ceph_decode_need(p, end, sizeof(u8), bad); \ + v = ceph_decode_8(p); \ + } while (0) + +#define ceph_decode_copy_safe(p, end, pv, n, bad) \ + do { \ + ceph_decode_need(p, end, n, bad); \ + ceph_decode_copy(p, pv, n); \ + } while (0) + +/* + * Allocate a buffer big enough to hold the wire-encoded string, and + * decode the string into it. The resulting string will always be + * terminated with '\0'. If successful, *p will be advanced + * past the decoded data. Also, if lenp is not a null pointer, the + * length (not including the terminating '\0') will be recorded in + * *lenp. Note that a zero-length string is a valid return value. + * + * Returns a pointer to the newly-allocated string buffer, or a + * pointer-coded errno if an error occurs. Neither *p nor *lenp + * will have been updated if an error is returned. + * + * There are two possible failures: + * - converting the string would require accessing memory at or + * beyond the "end" pointer provided (-ERANGE) + * - memory could not be allocated for the result (-ENOMEM) + */ +static inline char *ceph_extract_encoded_string(void **p, void *end, + size_t *lenp, gfp_t gfp) +{ + u32 len; + void *sp = *p; + char *buf; + + ceph_decode_32_safe(&sp, end, len, bad); + if (!ceph_has_room(&sp, end, len)) + goto bad; + + buf = kmalloc(len + 1, gfp); + if (!buf) + return ERR_PTR(-ENOMEM); + + if (len) + memcpy(buf, sp, len); + buf[len] = '\0'; + + *p = (char *) *p + sizeof (u32) + len; + if (lenp) + *lenp = (size_t) len; + + return buf; + +bad: + return ERR_PTR(-ERANGE); +} + +/* + * skip helpers + */ +#define ceph_decode_skip_n(p, end, n, bad) \ + do { \ + ceph_decode_need(p, end, n, bad); \ + *p += n; \ + } while (0) + +#define ceph_decode_skip_64(p, end, bad) \ +ceph_decode_skip_n(p, end, sizeof(u64), bad) + +#define ceph_decode_skip_32(p, end, bad) \ +ceph_decode_skip_n(p, end, sizeof(u32), bad) + +#define ceph_decode_skip_16(p, end, bad) \ +ceph_decode_skip_n(p, end, sizeof(u16), bad) + +#define ceph_decode_skip_8(p, end, bad) \ +ceph_decode_skip_n(p, end, sizeof(u8), bad) + +#define ceph_decode_skip_string(p, end, bad) \ + do { \ + u32 len; \ + \ + ceph_decode_32_safe(p, end, len, bad); \ + ceph_decode_skip_n(p, end, len, bad); \ + } while (0) + +#define ceph_decode_skip_set(p, end, type, bad) \ + do { \ + u32 len; \ + \ + ceph_decode_32_safe(p, end, len, bad); \ + while (len--) \ + ceph_decode_skip_##type(p, end, bad); \ + } while (0) + +#define ceph_decode_skip_map(p, end, ktype, vtype, bad) \ + do { \ + u32 len; \ + \ + ceph_decode_32_safe(p, end, len, bad); \ + while (len--) { \ + ceph_decode_skip_##ktype(p, end, bad); \ + ceph_decode_skip_##vtype(p, end, bad); \ + } \ + } while (0) + +#define ceph_decode_skip_map_of_map(p, end, ktype1, ktype2, vtype2, bad) \ + do { \ + u32 len; \ + \ + ceph_decode_32_safe(p, end, len, bad); \ + while (len--) { \ + ceph_decode_skip_##ktype1(p, end, bad); \ + ceph_decode_skip_map(p, end, ktype2, vtype2, bad); \ + } \ + } while (0) + +/* + * struct ceph_timespec <-> struct timespec64 + */ +static inline void ceph_decode_timespec64(struct timespec64 *ts, + const struct ceph_timespec *tv) +{ + /* + * This will still overflow in year 2106. We could extend + * the protocol to steal two more bits from tv_nsec to + * add three more 136 year epochs after that the way ext4 + * does if necessary. + */ + ts->tv_sec = (time64_t)le32_to_cpu(tv->tv_sec); + ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec); +} +static inline void ceph_encode_timespec64(struct ceph_timespec *tv, + const struct timespec64 *ts) +{ + tv->tv_sec = cpu_to_le32((u32)ts->tv_sec); + tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec); +} + +/* + * sockaddr_storage <-> ceph_sockaddr + */ +#define CEPH_ENTITY_ADDR_TYPE_NONE 0 +#define CEPH_ENTITY_ADDR_TYPE_LEGACY __cpu_to_le32(1) +#define CEPH_ENTITY_ADDR_TYPE_MSGR2 __cpu_to_le32(2) +#define CEPH_ENTITY_ADDR_TYPE_ANY __cpu_to_le32(3) + +static inline void ceph_encode_banner_addr(struct ceph_entity_addr *a) +{ + __be16 ss_family = htons(a->in_addr.ss_family); + a->in_addr.ss_family = *(__u16 *)&ss_family; + + /* Banner addresses require TYPE_NONE */ + a->type = CEPH_ENTITY_ADDR_TYPE_NONE; +} +static inline void ceph_decode_banner_addr(struct ceph_entity_addr *a) +{ + __be16 ss_family = *(__be16 *)&a->in_addr.ss_family; + a->in_addr.ss_family = ntohs(ss_family); + WARN_ON(a->in_addr.ss_family == 512); + a->type = CEPH_ENTITY_ADDR_TYPE_LEGACY; +} + +extern int ceph_decode_entity_addr(void **p, void *end, + struct ceph_entity_addr *addr); +int ceph_decode_entity_addrvec(void **p, void *end, bool msgr2, + struct ceph_entity_addr *addr); + +int ceph_entity_addr_encoding_len(const struct ceph_entity_addr *addr); +void ceph_encode_entity_addr(void **p, const struct ceph_entity_addr *addr); + +/* + * encoders + */ +static inline void ceph_encode_64(void **p, u64 v) +{ + put_unaligned_le64(v, (__le64 *)*p); + *p += sizeof(u64); +} +static inline void ceph_encode_32(void **p, u32 v) +{ + put_unaligned_le32(v, (__le32 *)*p); + *p += sizeof(u32); +} +static inline void ceph_encode_16(void **p, u16 v) +{ + put_unaligned_le16(v, (__le16 *)*p); + *p += sizeof(u16); +} +static inline void ceph_encode_8(void **p, u8 v) +{ + *(u8 *)*p = v; + (*p)++; +} +static inline void ceph_encode_copy(void **p, const void *s, int len) +{ + memcpy(*p, s, len); + *p += len; +} + +/* + * filepath, string encoders + */ +static inline void ceph_encode_filepath(void **p, void *end, + u64 ino, const char *path) +{ + u32 len = path ? strlen(path) : 0; + BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end); + ceph_encode_8(p, 1); + ceph_encode_64(p, ino); + ceph_encode_32(p, len); + if (len) + memcpy(*p, path, len); + *p += len; +} + +static inline void ceph_encode_string(void **p, void *end, + const char *s, u32 len) +{ + BUG_ON(*p + sizeof(len) + len > end); + ceph_encode_32(p, len); + if (len) + memcpy(*p, s, len); + *p += len; +} + +/* + * version and length starting block encoders/decoders + */ + +/* current code version (u8) + compat code version (u8) + len of struct (u32) */ +#define CEPH_ENCODING_START_BLK_LEN 6 + +/** + * ceph_start_encoding - start encoding block + * @struct_v: current (code) version of the encoding + * @struct_compat: oldest code version that can decode it + * @struct_len: length of struct encoding + */ +static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat, + u32 struct_len) +{ + ceph_encode_8(p, struct_v); + ceph_encode_8(p, struct_compat); + ceph_encode_32(p, struct_len); +} + +/** + * ceph_start_decoding - start decoding block + * @v: current version of the encoding that the code supports + * @name: name of the struct (free-form) + * @struct_v: out param for the encoding version + * @struct_len: out param for the length of struct encoding + * + * Validates the length of struct encoding, so unsafe ceph_decode_* + * variants can be used for decoding. + */ +static inline int ceph_start_decoding(void **p, void *end, u8 v, + const char *name, u8 *struct_v, + u32 *struct_len) +{ + u8 struct_compat; + + ceph_decode_need(p, end, CEPH_ENCODING_START_BLK_LEN, bad); + *struct_v = ceph_decode_8(p); + struct_compat = ceph_decode_8(p); + if (v < struct_compat) { + pr_warn("got struct_v %d struct_compat %d > %d of %s\n", + *struct_v, struct_compat, v, name); + return -EINVAL; + } + + *struct_len = ceph_decode_32(p); + ceph_decode_need(p, end, *struct_len, bad); + return 0; + +bad: + return -ERANGE; +} + +#define ceph_encode_need(p, end, n, bad) \ + do { \ + if (!likely(ceph_has_room(p, end, n))) \ + goto bad; \ + } while (0) + +#define ceph_encode_64_safe(p, end, v, bad) \ + do { \ + ceph_encode_need(p, end, sizeof(u64), bad); \ + ceph_encode_64(p, v); \ + } while (0) +#define ceph_encode_32_safe(p, end, v, bad) \ + do { \ + ceph_encode_need(p, end, sizeof(u32), bad); \ + ceph_encode_32(p, v); \ + } while (0) +#define ceph_encode_16_safe(p, end, v, bad) \ + do { \ + ceph_encode_need(p, end, sizeof(u16), bad); \ + ceph_encode_16(p, v); \ + } while (0) +#define ceph_encode_8_safe(p, end, v, bad) \ + do { \ + ceph_encode_need(p, end, sizeof(u8), bad); \ + ceph_encode_8(p, v); \ + } while (0) + +#define ceph_encode_copy_safe(p, end, pv, n, bad) \ + do { \ + ceph_encode_need(p, end, n, bad); \ + ceph_encode_copy(p, pv, n); \ + } while (0) +#define ceph_encode_string_safe(p, end, s, n, bad) \ + do { \ + ceph_encode_need(p, end, n, bad); \ + ceph_encode_string(p, end, s, n); \ + } while (0) + + +#endif |