1 /*
2 * Dynamic data buffer
3 * Copyright (c) 2007-2012, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "includes.h"
10
11 #include "common.h"
12 #include "trace.h"
13 #include "wpabuf.h"
14
15 #ifdef WPA_TRACE
16 #define WPABUF_MAGIC 0x51a974e3
17
18 struct wpabuf_trace {
19 unsigned int magic;
20 } __attribute__((aligned(8)));
21
wpabuf_get_trace(const struct wpabuf * buf)22 static struct wpabuf_trace * wpabuf_get_trace(const struct wpabuf *buf)
23 {
24 return (struct wpabuf_trace *)
25 ((const u8 *) buf - sizeof(struct wpabuf_trace));
26 }
27 #endif /* WPA_TRACE */
28
29
wpabuf_overflow(const struct wpabuf * buf,size_t len)30 static void wpabuf_overflow(const struct wpabuf *buf, size_t len)
31 {
32 #ifdef WPA_TRACE
33 struct wpabuf_trace *trace = wpabuf_get_trace(buf);
34 if (trace->magic != WPABUF_MAGIC) {
35 wpa_printf(MSG_ERROR, "wpabuf: invalid magic %x",
36 trace->magic);
37 }
38 #endif /* WPA_TRACE */
39 wpa_printf(MSG_ERROR, "wpabuf %p (size=%lu used=%lu) overflow len=%lu",
40 buf, (unsigned long) buf->size, (unsigned long) buf->used,
41 (unsigned long) len);
42 wpa_trace_show("wpabuf overflow");
43 abort();
44 }
45
46
wpabuf_resize(struct wpabuf ** _buf,size_t add_len)47 int wpabuf_resize(struct wpabuf **_buf, size_t add_len)
48 {
49 struct wpabuf *buf = *_buf;
50 #ifdef WPA_TRACE
51 struct wpabuf_trace *trace;
52 #endif /* WPA_TRACE */
53
54 if (buf == NULL) {
55 *_buf = wpabuf_alloc(add_len);
56 return *_buf == NULL ? -1 : 0;
57 }
58
59 #ifdef WPA_TRACE
60 trace = wpabuf_get_trace(buf);
61 if (trace->magic != WPABUF_MAGIC) {
62 wpa_printf(MSG_ERROR, "wpabuf: invalid magic %x",
63 trace->magic);
64 wpa_trace_show("wpabuf_resize invalid magic");
65 abort();
66 }
67 #endif /* WPA_TRACE */
68
69 if (buf->used + add_len > buf->size) {
70 unsigned char *nbuf;
71 if (buf->flags & WPABUF_FLAG_EXT_DATA) {
72 nbuf = os_realloc(buf->buf, buf->used + add_len);
73 if (nbuf == NULL)
74 return -1;
75 os_memset(nbuf + buf->used, 0, add_len);
76 buf->buf = nbuf;
77 } else {
78 #ifdef WPA_TRACE
79 nbuf = os_realloc(trace, sizeof(struct wpabuf_trace) +
80 sizeof(struct wpabuf) +
81 buf->used + add_len);
82 if (nbuf == NULL)
83 return -1;
84 trace = (struct wpabuf_trace *) nbuf;
85 buf = (struct wpabuf *) (trace + 1);
86 os_memset(nbuf + sizeof(struct wpabuf_trace) +
87 sizeof(struct wpabuf) + buf->used, 0,
88 add_len);
89 #else /* WPA_TRACE */
90 nbuf = os_realloc(buf, sizeof(struct wpabuf) +
91 buf->used + add_len);
92 if (nbuf == NULL)
93 return -1;
94 buf = (struct wpabuf *) nbuf;
95 os_memset(nbuf + sizeof(struct wpabuf) + buf->used, 0,
96 add_len);
97 #endif /* WPA_TRACE */
98 buf->buf = (u8 *) (buf + 1);
99 *_buf = buf;
100 }
101 buf->size = buf->used + add_len;
102 }
103
104 return 0;
105 }
106
107
108 /**
109 * wpabuf_alloc - Allocate a wpabuf of the given size
110 * @len: Length for the allocated buffer
111 * Returns: Buffer to the allocated wpabuf or %NULL on failure
112 */
wpabuf_alloc(size_t len)113 struct wpabuf * wpabuf_alloc(size_t len)
114 {
115 #ifdef WPA_TRACE
116 struct wpabuf_trace *trace = os_zalloc(sizeof(struct wpabuf_trace) +
117 sizeof(struct wpabuf) + len);
118 struct wpabuf *buf;
119 if (trace == NULL)
120 return NULL;
121 trace->magic = WPABUF_MAGIC;
122 buf = (struct wpabuf *) (trace + 1);
123 #else /* WPA_TRACE */
124 struct wpabuf *buf = os_zalloc(sizeof(struct wpabuf) + len);
125 if (buf == NULL)
126 return NULL;
127 #endif /* WPA_TRACE */
128
129 buf->size = len;
130 buf->buf = (u8 *) (buf + 1);
131 return buf;
132 }
133
134
wpabuf_alloc_ext_data(u8 * data,size_t len)135 struct wpabuf * wpabuf_alloc_ext_data(u8 *data, size_t len)
136 {
137 #ifdef WPA_TRACE
138 struct wpabuf_trace *trace = os_zalloc(sizeof(struct wpabuf_trace) +
139 sizeof(struct wpabuf));
140 struct wpabuf *buf;
141 if (trace == NULL)
142 return NULL;
143 trace->magic = WPABUF_MAGIC;
144 buf = (struct wpabuf *) (trace + 1);
145 #else /* WPA_TRACE */
146 struct wpabuf *buf = os_zalloc(sizeof(struct wpabuf));
147 if (buf == NULL)
148 return NULL;
149 #endif /* WPA_TRACE */
150
151 buf->size = len;
152 buf->used = len;
153 buf->buf = data;
154 buf->flags |= WPABUF_FLAG_EXT_DATA;
155
156 return buf;
157 }
158
159
wpabuf_alloc_copy(const void * data,size_t len)160 struct wpabuf * wpabuf_alloc_copy(const void *data, size_t len)
161 {
162 struct wpabuf *buf = wpabuf_alloc(len);
163 if (buf)
164 wpabuf_put_data(buf, data, len);
165 return buf;
166 }
167
168
wpabuf_dup(const struct wpabuf * src)169 struct wpabuf * wpabuf_dup(const struct wpabuf *src)
170 {
171 struct wpabuf *buf = wpabuf_alloc(wpabuf_len(src));
172 if (buf)
173 wpabuf_put_data(buf, wpabuf_head(src), wpabuf_len(src));
174 return buf;
175 }
176
177
178 /**
179 * wpabuf_free - Free a wpabuf
180 * @buf: wpabuf buffer
181 */
wpabuf_free(struct wpabuf * buf)182 void wpabuf_free(struct wpabuf *buf)
183 {
184 #ifdef WPA_TRACE
185 struct wpabuf_trace *trace;
186 if (buf == NULL)
187 return;
188 trace = wpabuf_get_trace(buf);
189 if (trace->magic != WPABUF_MAGIC) {
190 wpa_printf(MSG_ERROR, "wpabuf_free: invalid magic %x",
191 trace->magic);
192 wpa_trace_show("wpabuf_free magic mismatch");
193 abort();
194 }
195 if (buf->flags & WPABUF_FLAG_EXT_DATA)
196 os_free(buf->buf);
197 os_free(trace);
198 #else /* WPA_TRACE */
199 if (buf == NULL)
200 return;
201 if (buf->flags & WPABUF_FLAG_EXT_DATA)
202 os_free(buf->buf);
203 os_free(buf);
204 #endif /* WPA_TRACE */
205 }
206
207
wpabuf_clear_free(struct wpabuf * buf)208 void wpabuf_clear_free(struct wpabuf *buf)
209 {
210 if (buf) {
211 os_memset(wpabuf_mhead(buf), 0, wpabuf_len(buf));
212 wpabuf_free(buf);
213 }
214 }
215
216
wpabuf_put(struct wpabuf * buf,size_t len)217 void * wpabuf_put(struct wpabuf *buf, size_t len)
218 {
219 void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf);
220 buf->used += len;
221 if (buf->used > buf->size) {
222 wpabuf_overflow(buf, len);
223 }
224 return tmp;
225 }
226
227
228 /**
229 * wpabuf_concat - Concatenate two buffers into a newly allocated one
230 * @a: First buffer
231 * @b: Second buffer
232 * Returns: wpabuf with concatenated a + b data or %NULL on failure
233 *
234 * Both buffers a and b will be freed regardless of the return value. Input
235 * buffers can be %NULL which is interpreted as an empty buffer.
236 */
wpabuf_concat(struct wpabuf * a,struct wpabuf * b)237 struct wpabuf * wpabuf_concat(struct wpabuf *a, struct wpabuf *b)
238 {
239 struct wpabuf *n = NULL;
240 size_t len = 0;
241
242 if (b == NULL)
243 return a;
244
245 if (a)
246 len += wpabuf_len(a);
247 if (b)
248 len += wpabuf_len(b);
249
250 n = wpabuf_alloc(len);
251 if (n) {
252 if (a)
253 wpabuf_put_buf(n, a);
254 if (b)
255 wpabuf_put_buf(n, b);
256 }
257
258 wpabuf_free(a);
259 wpabuf_free(b);
260
261 return n;
262 }
263
264
265 /**
266 * wpabuf_zeropad - Pad buffer with 0x00 octets (prefix) to specified length
267 * @buf: Buffer to be padded
268 * @len: Length for the padded buffer
269 * Returns: wpabuf padded to len octets or %NULL on failure
270 *
271 * If buf is longer than len octets or of same size, it will be returned as-is.
272 * Otherwise a new buffer is allocated and prefixed with 0x00 octets followed
273 * by the source data. The source buffer will be freed on error, i.e., caller
274 * will only be responsible on freeing the returned buffer. If buf is %NULL,
275 * %NULL will be returned.
276 */
wpabuf_zeropad(struct wpabuf * buf,size_t len)277 struct wpabuf * wpabuf_zeropad(struct wpabuf *buf, size_t len)
278 {
279 struct wpabuf *ret;
280 size_t blen;
281
282 if (buf == NULL)
283 return NULL;
284
285 blen = wpabuf_len(buf);
286 if (blen >= len)
287 return buf;
288
289 ret = wpabuf_alloc(len);
290 if (ret) {
291 os_memset(wpabuf_put(ret, len - blen), 0, len - blen);
292 wpabuf_put_buf(ret, buf);
293 }
294 wpabuf_free(buf);
295
296 return ret;
297 }
298
299
wpabuf_printf(struct wpabuf * buf,char * fmt,...)300 void wpabuf_printf(struct wpabuf *buf, char *fmt, ...)
301 {
302 va_list ap;
303 void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf);
304 int res;
305
306 va_start(ap, fmt);
307 res = vsnprintf(tmp, buf->size - buf->used, fmt, ap);
308 va_end(ap);
309 if (res < 0 || (size_t) res >= buf->size - buf->used)
310 wpabuf_overflow(buf, res);
311 buf->used += res;
312 }
313