| 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 | }; |
| 21 | |
| 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 | |
| 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 | |
| 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 | */ |
| 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 | |
| 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 | |
| 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 | |
| 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 | */ |
| 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 | |
| 208 | void * wpabuf_put(struct wpabuf *buf, size_t len) |
| 209 | { |
| 210 | void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf); |
| 211 | buf->used += len; |
| 212 | if (buf->used > buf->size) { |
| 213 | wpabuf_overflow(buf, len); |
| 214 | } |
| 215 | return tmp; |
| 216 | } |
| 217 | |
| 218 | |
| 219 | /** |
| 220 | * wpabuf_concat - Concatenate two buffers into a newly allocated one |
| 221 | * @a: First buffer |
| 222 | * @b: Second buffer |
| 223 | * Returns: wpabuf with concatenated a + b data or %NULL on failure |
| 224 | * |
| 225 | * Both buffers a and b will be freed regardless of the return value. Input |
| 226 | * buffers can be %NULL which is interpreted as an empty buffer. |
| 227 | */ |
| 228 | struct wpabuf * wpabuf_concat(struct wpabuf *a, struct wpabuf *b) |
| 229 | { |
| 230 | struct wpabuf *n = NULL; |
| 231 | size_t len = 0; |
| 232 | |
| 233 | if (b == NULL) |
| 234 | return a; |
| 235 | |
| 236 | if (a) |
| 237 | len += wpabuf_len(a); |
| 238 | if (b) |
| 239 | len += wpabuf_len(b); |
| 240 | |
| 241 | n = wpabuf_alloc(len); |
| 242 | if (n) { |
| 243 | if (a) |
| 244 | wpabuf_put_buf(n, a); |
| 245 | if (b) |
| 246 | wpabuf_put_buf(n, b); |
| 247 | } |
| 248 | |
| 249 | wpabuf_free(a); |
| 250 | wpabuf_free(b); |
| 251 | |
| 252 | return n; |
| 253 | } |
| 254 | |
| 255 | |
| 256 | /** |
| 257 | * wpabuf_zeropad - Pad buffer with 0x00 octets (prefix) to specified length |
| 258 | * @buf: Buffer to be padded |
| 259 | * @len: Length for the padded buffer |
| 260 | * Returns: wpabuf padded to len octets or %NULL on failure |
| 261 | * |
| 262 | * If buf is longer than len octets or of same size, it will be returned as-is. |
| 263 | * Otherwise a new buffer is allocated and prefixed with 0x00 octets followed |
| 264 | * by the source data. The source buffer will be freed on error, i.e., caller |
| 265 | * will only be responsible on freeing the returned buffer. If buf is %NULL, |
| 266 | * %NULL will be returned. |
| 267 | */ |
| 268 | struct wpabuf * wpabuf_zeropad(struct wpabuf *buf, size_t len) |
| 269 | { |
| 270 | struct wpabuf *ret; |
| 271 | size_t blen; |
| 272 | |
| 273 | if (buf == NULL) |
| 274 | return NULL; |
| 275 | |
| 276 | blen = wpabuf_len(buf); |
| 277 | if (blen >= len) |
| 278 | return buf; |
| 279 | |
| 280 | ret = wpabuf_alloc(len); |
| 281 | if (ret) { |
| 282 | os_memset(wpabuf_put(ret, len - blen), 0, len - blen); |
| 283 | wpabuf_put_buf(ret, buf); |
| 284 | } |
| 285 | wpabuf_free(buf); |
| 286 | |
| 287 | return ret; |
| 288 | } |
| 289 | |
| 290 | |
| 291 | void wpabuf_printf(struct wpabuf *buf, char *fmt, ...) |
| 292 | { |
| 293 | va_list ap; |
| 294 | void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf); |
| 295 | int res; |
| 296 | |
| 297 | va_start(ap, fmt); |
| 298 | res = vsnprintf(tmp, buf->size - buf->used, fmt, ap); |
| 299 | va_end(ap); |
| 300 | if (res < 0 || (size_t) res >= buf->size - buf->used) |
| 301 | wpabuf_overflow(buf, res); |
| 302 | buf->used += res; |
| 303 | } |