1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3*0957b409SSimon J. Gerraty *
4*0957b409SSimon J. Gerraty * Permission is hereby granted, free of charge, to any person obtaining
5*0957b409SSimon J. Gerraty * a copy of this software and associated documentation files (the
6*0957b409SSimon J. Gerraty * "Software"), to deal in the Software without restriction, including
7*0957b409SSimon J. Gerraty * without limitation the rights to use, copy, modify, merge, publish,
8*0957b409SSimon J. Gerraty * distribute, sublicense, and/or sell copies of the Software, and to
9*0957b409SSimon J. Gerraty * permit persons to whom the Software is furnished to do so, subject to
10*0957b409SSimon J. Gerraty * the following conditions:
11*0957b409SSimon J. Gerraty *
12*0957b409SSimon J. Gerraty * The above copyright notice and this permission notice shall be
13*0957b409SSimon J. Gerraty * included in all copies or substantial portions of the Software.
14*0957b409SSimon J. Gerraty *
15*0957b409SSimon J. Gerraty * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16*0957b409SSimon J. Gerraty * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17*0957b409SSimon J. Gerraty * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18*0957b409SSimon J. Gerraty * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19*0957b409SSimon J. Gerraty * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20*0957b409SSimon J. Gerraty * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21*0957b409SSimon J. Gerraty * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*0957b409SSimon J. Gerraty * SOFTWARE.
23*0957b409SSimon J. Gerraty */
24*0957b409SSimon J. Gerraty
25*0957b409SSimon J. Gerraty #include "brssl.h"
26*0957b409SSimon J. Gerraty
27*0957b409SSimon J. Gerraty /*
28*0957b409SSimon J. Gerraty * Prepare a vector buffer for adding 'extra' elements.
29*0957b409SSimon J. Gerraty * buf current buffer
30*0957b409SSimon J. Gerraty * esize size of a vector element
31*0957b409SSimon J. Gerraty * ptr pointer to the 'ptr' vector field
32*0957b409SSimon J. Gerraty * len pointer to the 'len' vector field
33*0957b409SSimon J. Gerraty * extra number of elements to add
34*0957b409SSimon J. Gerraty *
35*0957b409SSimon J. Gerraty * If the buffer must be enlarged, then this function allocates the new
36*0957b409SSimon J. Gerraty * buffer and releases the old one. The new buffer address is then returned.
37*0957b409SSimon J. Gerraty * If the buffer needs not be enlarged, then the buffer address is returned.
38*0957b409SSimon J. Gerraty *
39*0957b409SSimon J. Gerraty * In case of enlargement, the 'len' field is adjusted accordingly. The
40*0957b409SSimon J. Gerraty * 'ptr' field is not modified.
41*0957b409SSimon J. Gerraty */
42*0957b409SSimon J. Gerraty void *
vector_expand(void * buf,size_t esize,size_t * ptr,size_t * len,size_t extra)43*0957b409SSimon J. Gerraty vector_expand(void *buf,
44*0957b409SSimon J. Gerraty size_t esize, size_t *ptr, size_t *len, size_t extra)
45*0957b409SSimon J. Gerraty {
46*0957b409SSimon J. Gerraty size_t nlen;
47*0957b409SSimon J. Gerraty void *nbuf;
48*0957b409SSimon J. Gerraty
49*0957b409SSimon J. Gerraty if (*len - *ptr >= extra) {
50*0957b409SSimon J. Gerraty return buf;
51*0957b409SSimon J. Gerraty }
52*0957b409SSimon J. Gerraty nlen = (*len << 1);
53*0957b409SSimon J. Gerraty if (nlen - *ptr < extra) {
54*0957b409SSimon J. Gerraty nlen = extra + *ptr;
55*0957b409SSimon J. Gerraty if (nlen < 8) {
56*0957b409SSimon J. Gerraty nlen = 8;
57*0957b409SSimon J. Gerraty }
58*0957b409SSimon J. Gerraty }
59*0957b409SSimon J. Gerraty nbuf = xmalloc(nlen * esize);
60*0957b409SSimon J. Gerraty if (buf != NULL) {
61*0957b409SSimon J. Gerraty memcpy(nbuf, buf, *len * esize);
62*0957b409SSimon J. Gerraty xfree(buf);
63*0957b409SSimon J. Gerraty }
64*0957b409SSimon J. Gerraty *len = nlen;
65*0957b409SSimon J. Gerraty return nbuf;
66*0957b409SSimon J. Gerraty }
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