/*

 * Dynamic data buffer

 * Copyright (c) 2007-2012, Jouni Malinen <j@w1.fi>

 *

 * This software may be distributed under the terms of the BSD license.

 * See README 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;

} __attribute__((aligned(8)));

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->flags & WPABUF_FLAG_EXT_DATA) {

      nbuf = os_realloc(buf->buf, buf->used + add_len);

      if (nbuf == NULL)

        return -1;

      os_memset(nbuf + buf->used, 0, add_len);

      buf->buf = 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 = (u8 *) (buf + 1);

      *_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;

  buf->buf = (u8 *) (buf + 1);

  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->buf = data;

  buf->flags |= WPABUF_FLAG_EXT_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();

  }

  if (buf->flags & WPABUF_FLAG_EXT_DATA)

    os_free(buf->buf);

  os_free(trace);

#else /* WPA_TRACE */

  if (buf == NULL)

    return;

  if (buf->flags & WPABUF_FLAG_EXT_DATA)

    os_free(buf->buf);

  os_free(buf);

#endif /* WPA_TRACE */

}

void wpabuf_clear_free(struct wpabuf *buf)

{

  if (buf) {

    os_memset(wpabuf_mhead(buf), 0, wpabuf_len(buf));

    wpabuf_free(buf);

  }

}

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);

  len += wpabuf_len(b);

  n = wpabuf_alloc(len);

  if (n) {

    if (a)

      wpabuf_put_buf(n, a);

    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;

}

/**

 * wpabuf_parse_bin - Parse a null terminated string of binary data to a wpabuf

 * @buf: Buffer with null terminated string (hexdump) of binary data

 * Returns: wpabuf or %NULL on failure

 *

 * The string len must be a multiple of two and contain only hexadecimal digits.

 */

struct wpabuf * wpabuf_parse_bin(const char *buf)

{

  size_t len;

  struct wpabuf *ret;

  len = os_strlen(buf);

  if (len & 0x01)

    return NULL;

  len /= 2;

  ret = wpabuf_alloc(len);

  if (ret == NULL)

    return NULL;

  if (hexstr2bin(buf, wpabuf_put(ret, len), len)) {

    wpabuf_free(ret);

    return NULL;

  }

  return ret;

}