dist/wpa/src/utils/wpabuf.c

   1 /*
   2  * Dynamic data buffer
   3  * Copyright (c) 2007-2008, 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 "wpabuf.h"
  19
  20 static void wpabuf_overflow(const struct wpabuf *buf, size_t len)
  21 {
  22         wpa_printf(MSG_ERROR, "wpabuf %p (size=%lu used=%lu) overflow len=%lu",
  23                    buf, (unsigned long) buf->size, (unsigned long) buf->used,
  24                    (unsigned long) len);
  25         abort();
  26 }
  27
  28
  29 int wpabuf_resize(struct wpabuf **_buf, size_t add_len)
  30 {
  31         struct wpabuf *buf = *_buf;
  32         if (buf->used + add_len > buf->size) {
  33                 unsigned char *nbuf;
  34                 if (buf->ext_data) {
  35                         nbuf = os_realloc(buf->ext_data, buf->used + add_len);
  36                         if (nbuf == NULL)
  37                                 return -1;
  38                         os_memset(nbuf + buf->used, 0, add_len);
  39                         buf->ext_data = nbuf;
  40                 } else {
  41                         nbuf = os_realloc(buf, sizeof(struct wpabuf) +
  42                                           buf->used + add_len);
  43                         if (nbuf == NULL)
  44                                 return -1;
  45                         buf = (struct wpabuf *) nbuf;
  46                         os_memset(nbuf + sizeof(struct wpabuf) + buf->used, 0,
  47                                   add_len);
  48                         *_buf = buf;
  49                 }
  50                 buf->size = buf->used + add_len;
  51         }
  52
  53         return 0;
  54 }
  55
  56
  57 /**
  58  * wpabuf_alloc - Allocate a wpabuf of the given size
  59  * @len: Length for the allocated buffer
  60  * Returns: Buffer to the allocated wpabuf or %NULL on failure
  61  */
  62 struct wpabuf * wpabuf_alloc(size_t len)
  63 {
  64         struct wpabuf *buf = os_zalloc(sizeof(struct wpabuf) + len);
  65         if (buf == NULL)
  66                 return NULL;
  67         buf->size = len;
  68         return buf;
  69 }
  70
  71
  72 struct wpabuf * wpabuf_alloc_ext_data(u8 *data, size_t len)
  73 {
  74         struct wpabuf *buf = os_zalloc(sizeof(struct wpabuf));
  75         if (buf == NULL)
  76                 return NULL;
  77
  78         buf->size = len;
  79         buf->used = len;
  80         buf->ext_data = data;
  81
  82         return buf;
  83 }
  84
  85
  86 struct wpabuf * wpabuf_alloc_copy(const void *data, size_t len)
  87 {
  88         struct wpabuf *buf = wpabuf_alloc(len);
  89         if (buf)
  90                 wpabuf_put_data(buf, data, len);
  91         return buf;
  92 }
  93
  94
  95 struct wpabuf * wpabuf_dup(const struct wpabuf *src)
  96 {
  97         struct wpabuf *buf = wpabuf_alloc(wpabuf_len(src));
  98         if (buf)
  99                 wpabuf_put_data(buf, wpabuf_head(src), wpabuf_len(src));
 100         return buf;
 101 }
 102
 103
 104 /**
 105  * wpabuf_free - Free a wpabuf
 106  * @buf: wpabuf buffer
 107  */
 108 void wpabuf_free(struct wpabuf *buf)
 109 {
 110         if (buf == NULL)
 111                 return;
 112         os_free(buf->ext_data);
 113         os_free(buf);
 114 }
 115
 116
 117 void * wpabuf_put(struct wpabuf *buf, size_t len)
 118 {
 119         void *tmp = wpabuf_mhead_u8(buf) + wpabuf_len(buf);
 120         buf->used += len;
 121         if (buf->used > buf->size) {
 122                 wpabuf_overflow(buf, len);
 123         }
 124         return tmp;
 125 }
 126
 127
 128 /**
 129  * wpabuf_concat - Concatenate two buffers into a newly allocated one
 130  * @a: First buffer
 131  * @b: Second buffer
 132  * Returns: wpabuf with concatenated a + b data or %NULL on failure
 133  *
 134  * Both buffers a and b will be freed regardless of the return value. Input
 135  * buffers can be %NULL which is interpreted as an empty buffer.
 136  */
 137 struct wpabuf * wpabuf_concat(struct wpabuf *a, struct wpabuf *b)
 138 {
 139         struct wpabuf *n = NULL;
 140         size_t len = 0;
 141
 142         if (b == NULL)
 143                 return a;
 144
 145         if (a)
 146                 len += wpabuf_len(a);
 147         if (b)
 148                 len += wpabuf_len(b);
 149
 150         n = wpabuf_alloc(len);
 151         if (n) {
 152                 if (a)
 153                         wpabuf_put_buf(n, a);
 154                 if (b)
 155                         wpabuf_put_buf(n, b);
 156         }
 157
 158         wpabuf_free(a);
 159         wpabuf_free(b);
 160
 161         return n;
 162 }