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
ceph_decode_64(void ** p)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 }
ceph_decode_32(void ** p)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 }
ceph_decode_16(void ** p)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 }
ceph_decode_8(void ** p)52 static inline u8 ceph_decode_8(void **p)
53 {
54 u8 v = *(u8 *)*p;
55 (*p)++;
56 return v;
57 }
ceph_decode_copy(void ** p,void * pv,size_t n)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 */
ceph_has_room(void ** p,void * end,size_t n)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 */
ceph_extract_encoded_string(void ** p,void * end,size_t * lenp,gfp_t gfp)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 */
ceph_decode_timespec(struct timespec * ts,const struct ceph_timespec * tv)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 }
ceph_encode_timespec(struct ceph_timespec * tv,const struct timespec * ts)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 */
ceph_encode_addr(struct ceph_entity_addr * a)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 }
ceph_decode_addr(struct ceph_entity_addr * a)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 */
ceph_encode_64(void ** p,u64 v)190 static inline void ceph_encode_64(void **p, u64 v)
191 {
192 put_unaligned_le64(v, (__le64 *)*p);
193 *p += sizeof(u64);
194 }
ceph_encode_32(void ** p,u32 v)195 static inline void ceph_encode_32(void **p, u32 v)
196 {
197 put_unaligned_le32(v, (__le32 *)*p);
198 *p += sizeof(u32);
199 }
ceph_encode_16(void ** p,u16 v)200 static inline void ceph_encode_16(void **p, u16 v)
201 {
202 put_unaligned_le16(v, (__le16 *)*p);
203 *p += sizeof(u16);
204 }
ceph_encode_8(void ** p,u8 v)205 static inline void ceph_encode_8(void **p, u8 v)
206 {
207 *(u8 *)*p = v;
208 (*p)++;
209 }
ceph_encode_copy(void ** p,const void * s,int len)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 */
ceph_encode_filepath(void ** p,void * end,u64 ino,const char * path)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
ceph_encode_string(void ** p,void * end,const char * s,u32 len)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