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31b8006e SW |
1 | #ifndef __CEPH_DECODE_H |
2 | #define __CEPH_DECODE_H | |
3 | ||
f8c36c58 | 4 | #include <linux/err.h> |
187f1882 | 5 | #include <linux/bug.h> |
b2aa5d0b | 6 | #include <linux/slab.h> |
c7e337d6 | 7 | #include <linux/time.h> |
187f1882 | 8 | #include <asm/unaligned.h> |
31b8006e | 9 | |
a1ce3928 | 10 | #include <linux/ceph/types.h> |
c89136ea | 11 | |
31b8006e SW |
12 | /* |
13 | * in all cases, | |
14 | * void **p pointer to position pointer | |
15 | * void *end pointer to end of buffer (last byte + 1) | |
16 | */ | |
17 | ||
c89136ea SW |
18 | static inline u64 ceph_decode_64(void **p) |
19 | { | |
20 | u64 v = get_unaligned_le64(*p); | |
21 | *p += sizeof(u64); | |
22 | return v; | |
23 | } | |
24 | static inline u32 ceph_decode_32(void **p) | |
25 | { | |
26 | u32 v = get_unaligned_le32(*p); | |
27 | *p += sizeof(u32); | |
28 | return v; | |
29 | } | |
30 | static inline u16 ceph_decode_16(void **p) | |
31 | { | |
32 | u16 v = get_unaligned_le16(*p); | |
33 | *p += sizeof(u16); | |
34 | return v; | |
35 | } | |
36 | static inline u8 ceph_decode_8(void **p) | |
37 | { | |
38 | u8 v = *(u8 *)*p; | |
39 | (*p)++; | |
40 | return v; | |
41 | } | |
42 | static inline void ceph_decode_copy(void **p, void *pv, size_t n) | |
43 | { | |
44 | memcpy(pv, *p, n); | |
45 | *p += n; | |
46 | } | |
47 | ||
31b8006e SW |
48 | /* |
49 | * bounds check input. | |
50 | */ | |
3b33f692 | 51 | static inline bool ceph_has_room(void **p, void *end, size_t n) |
76aa542f XW |
52 | { |
53 | return end >= *p && n <= end - *p; | |
54 | } | |
55 | ||
dd5f049d AE |
56 | #define ceph_decode_need(p, end, n, bad) \ |
57 | do { \ | |
58 | if (!likely(ceph_has_room(p, end, n))) \ | |
59 | goto bad; \ | |
31b8006e SW |
60 | } while (0) |
61 | ||
31b8006e SW |
62 | #define ceph_decode_64_safe(p, end, v, bad) \ |
63 | do { \ | |
64 | ceph_decode_need(p, end, sizeof(u64), bad); \ | |
c89136ea | 65 | v = ceph_decode_64(p); \ |
31b8006e SW |
66 | } while (0) |
67 | #define ceph_decode_32_safe(p, end, v, bad) \ | |
68 | do { \ | |
69 | ceph_decode_need(p, end, sizeof(u32), bad); \ | |
c89136ea | 70 | v = ceph_decode_32(p); \ |
31b8006e SW |
71 | } while (0) |
72 | #define ceph_decode_16_safe(p, end, v, bad) \ | |
73 | do { \ | |
74 | ceph_decode_need(p, end, sizeof(u16), bad); \ | |
c89136ea | 75 | v = ceph_decode_16(p); \ |
31b8006e | 76 | } while (0) |
c7e337d6 SW |
77 | #define ceph_decode_8_safe(p, end, v, bad) \ |
78 | do { \ | |
79 | ceph_decode_need(p, end, sizeof(u8), bad); \ | |
80 | v = ceph_decode_8(p); \ | |
81 | } while (0) | |
31b8006e SW |
82 | |
83 | #define ceph_decode_copy_safe(p, end, pv, n, bad) \ | |
84 | do { \ | |
85 | ceph_decode_need(p, end, n, bad); \ | |
86 | ceph_decode_copy(p, pv, n); \ | |
87 | } while (0) | |
88 | ||
f8c36c58 AE |
89 | /* |
90 | * Allocate a buffer big enough to hold the wire-encoded string, and | |
91 | * decode the string into it. The resulting string will always be | |
92 | * terminated with '\0'. If successful, *p will be advanced | |
93 | * past the decoded data. Also, if lenp is not a null pointer, the | |
94 | * length (not including the terminating '\0') will be recorded in | |
95 | * *lenp. Note that a zero-length string is a valid return value. | |
96 | * | |
97 | * Returns a pointer to the newly-allocated string buffer, or a | |
98 | * pointer-coded errno if an error occurs. Neither *p nor *lenp | |
99 | * will have been updated if an error is returned. | |
100 | * | |
101 | * There are two possible failures: | |
102 | * - converting the string would require accessing memory at or | |
dd5f049d AE |
103 | * beyond the "end" pointer provided (-ERANGE) |
104 | * - memory could not be allocated for the result (-ENOMEM) | |
f8c36c58 AE |
105 | */ |
106 | static inline char *ceph_extract_encoded_string(void **p, void *end, | |
107 | size_t *lenp, gfp_t gfp) | |
108 | { | |
109 | u32 len; | |
110 | void *sp = *p; | |
111 | char *buf; | |
112 | ||
113 | ceph_decode_32_safe(&sp, end, len, bad); | |
114 | if (!ceph_has_room(&sp, end, len)) | |
115 | goto bad; | |
116 | ||
117 | buf = kmalloc(len + 1, gfp); | |
118 | if (!buf) | |
119 | return ERR_PTR(-ENOMEM); | |
120 | ||
121 | if (len) | |
122 | memcpy(buf, sp, len); | |
123 | buf[len] = '\0'; | |
124 | ||
125 | *p = (char *) *p + sizeof (u32) + len; | |
126 | if (lenp) | |
127 | *lenp = (size_t) len; | |
128 | ||
129 | return buf; | |
130 | ||
131 | bad: | |
132 | return ERR_PTR(-ERANGE); | |
133 | } | |
134 | ||
31b8006e SW |
135 | /* |
136 | * struct ceph_timespec <-> struct timespec | |
137 | */ | |
c89136ea | 138 | static inline void ceph_decode_timespec(struct timespec *ts, |
63f2d211 | 139 | const struct ceph_timespec *tv) |
c89136ea | 140 | { |
c3f56102 AE |
141 | ts->tv_sec = (__kernel_time_t)le32_to_cpu(tv->tv_sec); |
142 | ts->tv_nsec = (long)le32_to_cpu(tv->tv_nsec); | |
c89136ea SW |
143 | } |
144 | static inline void ceph_encode_timespec(struct ceph_timespec *tv, | |
63f2d211 | 145 | const struct timespec *ts) |
c89136ea | 146 | { |
c3f56102 AE |
147 | tv->tv_sec = cpu_to_le32((u32)ts->tv_sec); |
148 | tv->tv_nsec = cpu_to_le32((u32)ts->tv_nsec); | |
c89136ea | 149 | } |
31b8006e | 150 | |
63f2d211 SW |
151 | /* |
152 | * sockaddr_storage <-> ceph_sockaddr | |
153 | */ | |
154 | static inline void ceph_encode_addr(struct ceph_entity_addr *a) | |
155 | { | |
cd84db6e YS |
156 | __be16 ss_family = htons(a->in_addr.ss_family); |
157 | a->in_addr.ss_family = *(__u16 *)&ss_family; | |
63f2d211 SW |
158 | } |
159 | static inline void ceph_decode_addr(struct ceph_entity_addr *a) | |
160 | { | |
cd84db6e YS |
161 | __be16 ss_family = *(__be16 *)&a->in_addr.ss_family; |
162 | a->in_addr.ss_family = ntohs(ss_family); | |
4e7a5dcd | 163 | WARN_ON(a->in_addr.ss_family == 512); |
63f2d211 SW |
164 | } |
165 | ||
31b8006e SW |
166 | /* |
167 | * encoders | |
168 | */ | |
c89136ea SW |
169 | static inline void ceph_encode_64(void **p, u64 v) |
170 | { | |
171 | put_unaligned_le64(v, (__le64 *)*p); | |
172 | *p += sizeof(u64); | |
173 | } | |
174 | static inline void ceph_encode_32(void **p, u32 v) | |
175 | { | |
176 | put_unaligned_le32(v, (__le32 *)*p); | |
177 | *p += sizeof(u32); | |
178 | } | |
179 | static inline void ceph_encode_16(void **p, u16 v) | |
180 | { | |
181 | put_unaligned_le16(v, (__le16 *)*p); | |
182 | *p += sizeof(u16); | |
183 | } | |
184 | static inline void ceph_encode_8(void **p, u8 v) | |
185 | { | |
186 | *(u8 *)*p = v; | |
187 | (*p)++; | |
188 | } | |
4e7a5dcd SW |
189 | static inline void ceph_encode_copy(void **p, const void *s, int len) |
190 | { | |
191 | memcpy(*p, s, len); | |
192 | *p += len; | |
193 | } | |
31b8006e SW |
194 | |
195 | /* | |
196 | * filepath, string encoders | |
197 | */ | |
198 | static inline void ceph_encode_filepath(void **p, void *end, | |
199 | u64 ino, const char *path) | |
200 | { | |
201 | u32 len = path ? strlen(path) : 0; | |
c61a1abd | 202 | BUG_ON(*p + 1 + sizeof(ino) + sizeof(len) + len > end); |
ac8839d7 | 203 | ceph_encode_8(p, 1); |
31b8006e SW |
204 | ceph_encode_64(p, ino); |
205 | ceph_encode_32(p, len); | |
206 | if (len) | |
207 | memcpy(*p, path, len); | |
208 | *p += len; | |
209 | } | |
210 | ||
211 | static inline void ceph_encode_string(void **p, void *end, | |
212 | const char *s, u32 len) | |
213 | { | |
214 | BUG_ON(*p + sizeof(len) + len > end); | |
215 | ceph_encode_32(p, len); | |
216 | if (len) | |
217 | memcpy(*p, s, len); | |
218 | *p += len; | |
219 | } | |
220 | ||
22748f9d ID |
221 | /* |
222 | * version and length starting block encoders/decoders | |
223 | */ | |
224 | ||
225 | /* current code version (u8) + compat code version (u8) + len of struct (u32) */ | |
226 | #define CEPH_ENCODING_START_BLK_LEN 6 | |
227 | ||
228 | /** | |
229 | * ceph_start_encoding - start encoding block | |
230 | * @struct_v: current (code) version of the encoding | |
231 | * @struct_compat: oldest code version that can decode it | |
232 | * @struct_len: length of struct encoding | |
233 | */ | |
234 | static inline void ceph_start_encoding(void **p, u8 struct_v, u8 struct_compat, | |
235 | u32 struct_len) | |
236 | { | |
237 | ceph_encode_8(p, struct_v); | |
238 | ceph_encode_8(p, struct_compat); | |
239 | ceph_encode_32(p, struct_len); | |
240 | } | |
241 | ||
242 | /** | |
243 | * ceph_start_decoding - start decoding block | |
244 | * @v: current version of the encoding that the code supports | |
245 | * @name: name of the struct (free-form) | |
246 | * @struct_v: out param for the encoding version | |
247 | * @struct_len: out param for the length of struct encoding | |
248 | * | |
249 | * Validates the length of struct encoding, so unsafe ceph_decode_* | |
250 | * variants can be used for decoding. | |
251 | */ | |
252 | static inline int ceph_start_decoding(void **p, void *end, u8 v, | |
253 | const char *name, u8 *struct_v, | |
254 | u32 *struct_len) | |
255 | { | |
256 | u8 struct_compat; | |
257 | ||
258 | ceph_decode_need(p, end, CEPH_ENCODING_START_BLK_LEN, bad); | |
259 | *struct_v = ceph_decode_8(p); | |
260 | struct_compat = ceph_decode_8(p); | |
261 | if (v < struct_compat) { | |
262 | pr_warn("got struct_v %d struct_compat %d > %d of %s\n", | |
263 | *struct_v, struct_compat, v, name); | |
264 | return -EINVAL; | |
265 | } | |
266 | ||
267 | *struct_len = ceph_decode_32(p); | |
268 | ceph_decode_need(p, end, *struct_len, bad); | |
269 | return 0; | |
270 | ||
271 | bad: | |
272 | return -ERANGE; | |
273 | } | |
274 | ||
dd5f049d AE |
275 | #define ceph_encode_need(p, end, n, bad) \ |
276 | do { \ | |
277 | if (!likely(ceph_has_room(p, end, n))) \ | |
278 | goto bad; \ | |
c7e337d6 SW |
279 | } while (0) |
280 | ||
281 | #define ceph_encode_64_safe(p, end, v, bad) \ | |
282 | do { \ | |
283 | ceph_encode_need(p, end, sizeof(u64), bad); \ | |
284 | ceph_encode_64(p, v); \ | |
285 | } while (0) | |
286 | #define ceph_encode_32_safe(p, end, v, bad) \ | |
287 | do { \ | |
288 | ceph_encode_need(p, end, sizeof(u32), bad); \ | |
dd5f049d | 289 | ceph_encode_32(p, v); \ |
c7e337d6 SW |
290 | } while (0) |
291 | #define ceph_encode_16_safe(p, end, v, bad) \ | |
292 | do { \ | |
293 | ceph_encode_need(p, end, sizeof(u16), bad); \ | |
dd5f049d AE |
294 | ceph_encode_16(p, v); \ |
295 | } while (0) | |
296 | #define ceph_encode_8_safe(p, end, v, bad) \ | |
297 | do { \ | |
298 | ceph_encode_need(p, end, sizeof(u8), bad); \ | |
299 | ceph_encode_8(p, v); \ | |
c7e337d6 SW |
300 | } while (0) |
301 | ||
302 | #define ceph_encode_copy_safe(p, end, pv, n, bad) \ | |
303 | do { \ | |
304 | ceph_encode_need(p, end, n, bad); \ | |
305 | ceph_encode_copy(p, pv, n); \ | |
306 | } while (0) | |
ae1533b6 YS |
307 | #define ceph_encode_string_safe(p, end, s, n, bad) \ |
308 | do { \ | |
309 | ceph_encode_need(p, end, n, bad); \ | |
310 | ceph_encode_string(p, end, s, n); \ | |
311 | } while (0) | |
c7e337d6 | 312 | |
31b8006e SW |
313 | |
314 | #endif |