hostap/src/utils/wpabuf.c
2009-12-28 16:02:11 +02:00

304 lines
6.8 KiB
C

/*
* Dynamic data buffer
* Copyright (c) 2007-2009, Jouni Malinen <j@w1.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#include "includes.h"
#include "common.h"
#include "trace.h"
#include "wpabuf.h"
#ifdef WPA_TRACE
#define WPABUF_MAGIC 0x51a974e3
struct wpabuf_trace {
unsigned int magic;
};
static struct wpabuf_trace * wpabuf_get_trace(const struct wpabuf *buf)
{
return (struct wpabuf_trace *)
((const u8 *) buf - sizeof(struct wpabuf_trace));
}
#endif /* WPA_TRACE */
static void wpabuf_overflow(const struct wpabuf *buf, size_t len)
{
#ifdef WPA_TRACE
struct wpabuf_trace *trace = wpabuf_get_trace(buf);
if (trace->magic != WPABUF_MAGIC) {
wpa_printf(MSG_ERROR, "wpabuf: invalid magic %x",
trace->magic);
}
#endif /* WPA_TRACE */
wpa_printf(MSG_ERROR, "wpabuf %p (size=%lu used=%lu) overflow len=%lu",
buf, (unsigned long) buf->size, (unsigned long) buf->used,
(unsigned long) len);
wpa_trace_show("wpabuf overflow");
abort();
}
int wpabuf_resize(struct wpabuf **_buf, size_t add_len)
{
struct wpabuf *buf = *_buf;
#ifdef WPA_TRACE
struct wpabuf_trace *trace;
#endif /* WPA_TRACE */
if (buf == NULL) {
*_buf = wpabuf_alloc(add_len);
return *_buf == NULL ? -1 : 0;
}
#ifdef WPA_TRACE
trace = wpabuf_get_trace(buf);
if (trace->magic != WPABUF_MAGIC) {
wpa_printf(MSG_ERROR, "wpabuf: invalid magic %x",
trace->magic);
wpa_trace_show("wpabuf_resize invalid magic");
abort();
}
#endif /* WPA_TRACE */
if (buf->used + add_len > buf->size) {
unsigned char *nbuf;
if (buf->ext_data) {
nbuf = os_realloc(buf->ext_data, buf->used + add_len);
if (nbuf == NULL)
return -1;
os_memset(nbuf + buf->used, 0, add_len);
buf->ext_data = nbuf;
} else {
#ifdef WPA_TRACE
nbuf = os_realloc(trace, sizeof(struct wpabuf_trace) +
sizeof(struct wpabuf) +
buf->used + add_len);
if (nbuf == NULL)
return -1;
trace = (struct wpabuf_trace *) nbuf;
buf = (struct wpabuf *) (trace + 1);
os_memset(nbuf + sizeof(struct wpabuf_trace) +
sizeof(struct wpabuf) + buf->used, 0,
add_len);
#else /* WPA_TRACE */
nbuf = os_realloc(buf, sizeof(struct wpabuf) +
buf->used + add_len);
if (nbuf == NULL)
return -1;
buf = (struct wpabuf *) nbuf;
os_memset(nbuf + sizeof(struct wpabuf) + buf->used, 0,
add_len);
#endif /* WPA_TRACE */
*_buf = buf;
}
buf->size = buf->used + add_len;
}
return 0;
}
/**
* wpabuf_alloc - Allocate a wpabuf of the given size
* @len: Length for the allocated buffer
* Returns: Buffer to the allocated wpabuf or %NULL on failure
*/
struct wpabuf * wpabuf_alloc(size_t len)
{
#ifdef WPA_TRACE
struct wpabuf_trace *trace = os_zalloc(sizeof(struct wpabuf_trace) +
sizeof(struct wpabuf) + len);
struct wpabuf *buf;
if (trace == NULL)
return NULL;
trace->magic = WPABUF_MAGIC;
buf = (struct wpabuf *) (trace + 1);
#else /* WPA_TRACE */
struct wpabuf *buf = os_zalloc(sizeof(struct wpabuf) + len);
if (buf == NULL)
return NULL;
#endif /* WPA_TRACE */
buf->size = len;
return buf;
}
struct wpabuf * wpabuf_alloc_ext_data(u8 *data, size_t len)
{
#ifdef WPA_TRACE
struct wpabuf_trace *trace = os_zalloc(sizeof(struct wpabuf_trace) +
sizeof(struct wpabuf));
struct wpabuf *buf;
if (trace == NULL)
return NULL;
trace->magic = WPABUF_MAGIC;
buf = (struct wpabuf *) (trace + 1);
#else /* WPA_TRACE */
struct wpabuf *buf = os_zalloc(sizeof(struct wpabuf));
if (buf == NULL)
return NULL;
#endif /* WPA_TRACE */
buf->size = len;
buf->used = len;
buf->ext_data = data;
return buf;
}
struct wpabuf * wpabuf_alloc_copy(const void *data, size_t len)
{
struct wpabuf *buf = wpabuf_alloc(len);
if (buf)
wpabuf_put_data(buf, data, len);
return buf;
}
struct wpabuf * wpabuf_dup(const struct wpabuf *src)
{
struct wpabuf *buf = wpabuf_alloc(wpabuf_len(src));
if (buf)
wpabuf_put_data(buf, wpabuf_head(src), wpabuf_len(src));
return buf;
}
/**
* wpabuf_free - Free a wpabuf
* @buf: wpabuf buffer
*/
void wpabuf_free(struct wpabuf *buf)
{
#ifdef WPA_TRACE
struct wpabuf_trace *trace;
if (buf == NULL)
return;
trace = wpabuf_get_trace(buf);
if (trace->magic != WPABUF_MAGIC) {
wpa_printf(MSG_ERROR, "wpabuf_free: invalid magic %x",
trace->magic);
wpa_trace_show("wpabuf_free magic mismatch");
abort();
}
os_free(buf->ext_data);
os_free(trace);
#else /* WPA_TRACE */
if (buf == NULL)
return;
os_free(buf->ext_data);
os_free(buf);
#endif /* WPA_TRACE */
}
void * wpabuf_put(struct wpabuf *buf, size_t len)
{
void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf);
buf->used += len;
if (buf->used > buf->size) {
wpabuf_overflow(buf, len);
}
return tmp;
}
/**
* wpabuf_concat - Concatenate two buffers into a newly allocated one
* @a: First buffer
* @b: Second buffer
* Returns: wpabuf with concatenated a + b data or %NULL on failure
*
* Both buffers a and b will be freed regardless of the return value. Input
* buffers can be %NULL which is interpreted as an empty buffer.
*/
struct wpabuf * wpabuf_concat(struct wpabuf *a, struct wpabuf *b)
{
struct wpabuf *n = NULL;
size_t len = 0;
if (b == NULL)
return a;
if (a)
len += wpabuf_len(a);
if (b)
len += wpabuf_len(b);
n = wpabuf_alloc(len);
if (n) {
if (a)
wpabuf_put_buf(n, a);
if (b)
wpabuf_put_buf(n, b);
}
wpabuf_free(a);
wpabuf_free(b);
return n;
}
/**
* wpabuf_zeropad - Pad buffer with 0x00 octets (prefix) to specified length
* @buf: Buffer to be padded
* @len: Length for the padded buffer
* Returns: wpabuf padded to len octets or %NULL on failure
*
* If buf is longer than len octets or of same size, it will be returned as-is.
* Otherwise a new buffer is allocated and prefixed with 0x00 octets followed
* by the source data. The source buffer will be freed on error, i.e., caller
* will only be responsible on freeing the returned buffer. If buf is %NULL,
* %NULL will be returned.
*/
struct wpabuf * wpabuf_zeropad(struct wpabuf *buf, size_t len)
{
struct wpabuf *ret;
size_t blen;
if (buf == NULL)
return NULL;
blen = wpabuf_len(buf);
if (blen >= len)
return buf;
ret = wpabuf_alloc(len);
if (ret) {
os_memset(wpabuf_put(ret, len - blen), 0, len - blen);
wpabuf_put_buf(ret, buf);
}
wpabuf_free(buf);
return ret;
}
void wpabuf_printf(struct wpabuf *buf, char *fmt, ...)
{
va_list ap;
void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf);
int res;
va_start(ap, fmt);
res = vsnprintf(tmp, buf->size - buf->used, fmt, ap);
va_end(ap);
if (res < 0 || (size_t) res >= buf->size - buf->used)
wpabuf_overflow(buf, res);
buf->used += res;
}