1 /*
2 * Dynamic data buffer
3 * Copyright (c) 2007-2009, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15 #include "includes.h"
16
17 #include "common.h"
18 #include "trace.h"
19 #include "wpabuf.h"
20
21 #ifdef WPA_TRACE
22 #define WPABUF_MAGIC 0x51a974e3
23
24 struct wpabuf_trace {
25 unsigned int magic;
26 };
27
wpabuf_get_trace(const struct wpabuf * buf)28 static struct wpabuf_trace * wpabuf_get_trace(const struct wpabuf *buf)
29 {
30 return (struct wpabuf_trace *)
31 ((const u8 *) buf - sizeof(struct wpabuf_trace));
32 }
33 #endif /* WPA_TRACE */
34
35
wpabuf_overflow(const struct wpabuf * buf,size_t len)36 static void wpabuf_overflow(const struct wpabuf *buf, size_t len)
37 {
38 #ifdef WPA_TRACE
39 struct wpabuf_trace *trace = wpabuf_get_trace(buf);
40 if (trace->magic != WPABUF_MAGIC) {
41 wpa_printf(MSG_ERROR, "wpabuf: invalid magic %x",
42 trace->magic);
43 }
44 #endif /* WPA_TRACE */
45 wpa_printf(MSG_ERROR, "wpabuf %p (size=%lu used=%lu) overflow len=%lu",
46 buf, (unsigned long) buf->size, (unsigned long) buf->used,
47 (unsigned long) len);
48 wpa_trace_show("wpabuf overflow");
49 abort();
50 }
51
52
wpabuf_resize(struct wpabuf ** _buf,size_t add_len)53 int wpabuf_resize(struct wpabuf **_buf, size_t add_len)
54 {
55 struct wpabuf *buf = *_buf;
56 #ifdef WPA_TRACE
57 struct wpabuf_trace *trace;
58 #endif /* WPA_TRACE */
59
60 if (buf == NULL) {
61 *_buf = wpabuf_alloc(add_len);
62 return *_buf == NULL ? -1 : 0;
63 }
64
65 #ifdef WPA_TRACE
66 trace = wpabuf_get_trace(buf);
67 if (trace->magic != WPABUF_MAGIC) {
68 wpa_printf(MSG_ERROR, "wpabuf: invalid magic %x",
69 trace->magic);
70 wpa_trace_show("wpabuf_resize invalid magic");
71 abort();
72 }
73 #endif /* WPA_TRACE */
74
75 if (buf->used + add_len > buf->size) {
76 unsigned char *nbuf;
77 if (buf->ext_data) {
78 nbuf = os_realloc(buf->ext_data, buf->used + add_len);
79 if (nbuf == NULL)
80 return -1;
81 os_memset(nbuf + buf->used, 0, add_len);
82 buf->ext_data = nbuf;
83 } else {
84 #ifdef WPA_TRACE
85 nbuf = os_realloc(trace, sizeof(struct wpabuf_trace) +
86 sizeof(struct wpabuf) +
87 buf->used + add_len);
88 if (nbuf == NULL)
89 return -1;
90 trace = (struct wpabuf_trace *) nbuf;
91 buf = (struct wpabuf *) (trace + 1);
92 os_memset(nbuf + sizeof(struct wpabuf_trace) +
93 sizeof(struct wpabuf) + buf->used, 0,
94 add_len);
95 #else /* WPA_TRACE */
96 nbuf = os_realloc(buf, sizeof(struct wpabuf) +
97 buf->used + add_len);
98 if (nbuf == NULL)
99 return -1;
100 buf = (struct wpabuf *) nbuf;
101 os_memset(nbuf + sizeof(struct wpabuf) + buf->used, 0,
102 add_len);
103 #endif /* WPA_TRACE */
104 *_buf = buf;
105 }
106 buf->size = buf->used + add_len;
107 }
108
109 return 0;
110 }
111
112
113 /**
114 * wpabuf_alloc - Allocate a wpabuf of the given size
115 * @len: Length for the allocated buffer
116 * Returns: Buffer to the allocated wpabuf or %NULL on failure
117 */
wpabuf_alloc(size_t len)118 struct wpabuf * wpabuf_alloc(size_t len)
119 {
120 #ifdef WPA_TRACE
121 struct wpabuf_trace *trace = os_zalloc(sizeof(struct wpabuf_trace) +
122 sizeof(struct wpabuf) + len);
123 struct wpabuf *buf;
124 if (trace == NULL)
125 return NULL;
126 trace->magic = WPABUF_MAGIC;
127 buf = (struct wpabuf *) (trace + 1);
128 #else /* WPA_TRACE */
129 struct wpabuf *buf = os_zalloc(sizeof(struct wpabuf) + len);
130 if (buf == NULL)
131 return NULL;
132 #endif /* WPA_TRACE */
133
134 buf->size = len;
135 return buf;
136 }
137
138
wpabuf_alloc_ext_data(u8 * data,size_t len)139 struct wpabuf * wpabuf_alloc_ext_data(u8 *data, size_t len)
140 {
141 #ifdef WPA_TRACE
142 struct wpabuf_trace *trace = os_zalloc(sizeof(struct wpabuf_trace) +
143 sizeof(struct wpabuf));
144 struct wpabuf *buf;
145 if (trace == NULL)
146 return NULL;
147 trace->magic = WPABUF_MAGIC;
148 buf = (struct wpabuf *) (trace + 1);
149 #else /* WPA_TRACE */
150 struct wpabuf *buf = os_zalloc(sizeof(struct wpabuf));
151 if (buf == NULL)
152 return NULL;
153 #endif /* WPA_TRACE */
154
155 buf->size = len;
156 buf->used = len;
157 buf->ext_data = data;
158
159 return buf;
160 }
161
162
wpabuf_alloc_copy(const void * data,size_t len)163 struct wpabuf * wpabuf_alloc_copy(const void *data, size_t len)
164 {
165 struct wpabuf *buf = wpabuf_alloc(len);
166 if (buf)
167 wpabuf_put_data(buf, data, len);
168 return buf;
169 }
170
171
wpabuf_dup(const struct wpabuf * src)172 struct wpabuf * wpabuf_dup(const struct wpabuf *src)
173 {
174 struct wpabuf *buf = wpabuf_alloc(wpabuf_len(src));
175 if (buf)
176 wpabuf_put_data(buf, wpabuf_head(src), wpabuf_len(src));
177 return buf;
178 }
179
180
181 /**
182 * wpabuf_free - Free a wpabuf
183 * @buf: wpabuf buffer
184 */
wpabuf_free(struct wpabuf * buf)185 void wpabuf_free(struct wpabuf *buf)
186 {
187 #ifdef WPA_TRACE
188 struct wpabuf_trace *trace;
189 if (buf == NULL)
190 return;
191 trace = wpabuf_get_trace(buf);
192 if (trace->magic != WPABUF_MAGIC) {
193 wpa_printf(MSG_ERROR, "wpabuf_free: invalid magic %x",
194 trace->magic);
195 wpa_trace_show("wpabuf_free magic mismatch");
196 abort();
197 }
198 os_free(buf->ext_data);
199 os_free(trace);
200 #else /* WPA_TRACE */
201 if (buf == NULL)
202 return;
203 os_free(buf->ext_data);
204 os_free(buf);
205 #endif /* WPA_TRACE */
206 }
207
208
wpabuf_put(struct wpabuf * buf,size_t len)209 void * wpabuf_put(struct wpabuf *buf, size_t len)
210 {
211 void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf);
212 buf->used += len;
213 if (buf->used > buf->size) {
214 wpabuf_overflow(buf, len);
215 }
216 return tmp;
217 }
218
219
220 /**
221 * wpabuf_concat - Concatenate two buffers into a newly allocated one
222 * @a: First buffer
223 * @b: Second buffer
224 * Returns: wpabuf with concatenated a + b data or %NULL on failure
225 *
226 * Both buffers a and b will be freed regardless of the return value. Input
227 * buffers can be %NULL which is interpreted as an empty buffer.
228 */
wpabuf_concat(struct wpabuf * a,struct wpabuf * b)229 struct wpabuf * wpabuf_concat(struct wpabuf *a, struct wpabuf *b)
230 {
231 struct wpabuf *n = NULL;
232 size_t len = 0;
233
234 if (b == NULL)
235 return a;
236
237 if (a)
238 len += wpabuf_len(a);
239 if (b)
240 len += wpabuf_len(b);
241
242 n = wpabuf_alloc(len);
243 if (n) {
244 if (a)
245 wpabuf_put_buf(n, a);
246 if (b)
247 wpabuf_put_buf(n, b);
248 }
249
250 wpabuf_free(a);
251 wpabuf_free(b);
252
253 return n;
254 }
255
256
257 /**
258 * wpabuf_zeropad - Pad buffer with 0x00 octets (prefix) to specified length
259 * @buf: Buffer to be padded
260 * @len: Length for the padded buffer
261 * Returns: wpabuf padded to len octets or %NULL on failure
262 *
263 * If buf is longer than len octets or of same size, it will be returned as-is.
264 * Otherwise a new buffer is allocated and prefixed with 0x00 octets followed
265 * by the source data. The source buffer will be freed on error, i.e., caller
266 * will only be responsible on freeing the returned buffer. If buf is %NULL,
267 * %NULL will be returned.
268 */
wpabuf_zeropad(struct wpabuf * buf,size_t len)269 struct wpabuf * wpabuf_zeropad(struct wpabuf *buf, size_t len)
270 {
271 struct wpabuf *ret;
272 size_t blen;
273
274 if (buf == NULL)
275 return NULL;
276
277 blen = wpabuf_len(buf);
278 if (blen >= len)
279 return buf;
280
281 ret = wpabuf_alloc(len);
282 if (ret) {
283 os_memset(wpabuf_put(ret, len - blen), 0, len - blen);
284 wpabuf_put_buf(ret, buf);
285 }
286 wpabuf_free(buf);
287
288 return ret;
289 }
290
291
wpabuf_printf(struct wpabuf * buf,char * fmt,...)292 void wpabuf_printf(struct wpabuf *buf, char *fmt, ...)
293 {
294 va_list ap;
295 void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf);
296 int res;
297
298 va_start(ap, fmt);
299 res = vsnprintf(tmp, buf->size - buf->used, fmt, ap);
300 va_end(ap);
301 if (res < 0 || (size_t) res >= buf->size - buf->used)
302 wpabuf_overflow(buf, res);
303 buf->used += res;
304 }
305