Fido2 (#727)
[proxmark3-svn] / client / tinycbor / open_memstream.c
1 /****************************************************************************
2 **
3 ** Copyright (C) 2015 Intel Corporation
4 **
5 ** Permission is hereby granted, free of charge, to any person obtaining a copy
6 ** of this software and associated documentation files (the "Software"), to deal
7 ** in the Software without restriction, including without limitation the rights
8 ** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 ** copies of the Software, and to permit persons to whom the Software is
10 ** furnished to do so, subject to the following conditions:
11 **
12 ** The above copyright notice and this permission notice shall be included in
13 ** all copies or substantial portions of the Software.
14 **
15 ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 ** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 ** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 ** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 ** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 ** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 ** THE SOFTWARE.
22 **
23 ****************************************************************************/
24
25 #define _BSD_SOURCE 1
26 #define _DEFAULT_SOURCE 1
27 #define _GNU_SOURCE 1
28
29 #include <sys/types.h>
30 #include <errno.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34
35 #if defined(__unix__) || defined(__APPLE__)
36 # include <unistd.h>
37 #endif
38 #ifdef __APPLE__
39 typedef int RetType;
40 typedef int LenType;
41 #elif __GLIBC__
42 typedef ssize_t RetType;
43 typedef size_t LenType;
44 #else
45 # error "Cannot implement open_memstream!"
46 #endif
47
48 #include "compilersupport_p.h"
49
50 struct Buffer
51 {
52 char **ptr;
53 size_t *len;
54 size_t alloc;
55 };
56
57 static RetType write_to_buffer(void *cookie, const char *data, LenType len)
58 {
59 struct Buffer *b = (struct Buffer *)cookie;
60 char *ptr = *b->ptr;
61 size_t newsize;
62
63 errno = EFBIG;
64 if (unlikely(add_check_overflow(*b->len, len, &newsize)))
65 return -1;
66
67 if (newsize >= b->alloc) { // NB! one extra byte is needed to avoid buffer overflow at close_buffer
68 // make room
69 size_t newalloc = newsize + newsize / 2 + 1; // give 50% more room
70 ptr = realloc(ptr, newalloc);
71 if (ptr == NULL)
72 return -1;
73 b->alloc = newalloc;
74 *b->ptr = ptr;
75 }
76
77 memcpy(ptr + *b->len, data, len);
78 *b->len = newsize;
79 return len;
80 }
81
82 static int close_buffer(void *cookie)
83 {
84 struct Buffer *b = (struct Buffer *)cookie;
85 if (*b->ptr)
86 (*b->ptr)[*b->len] = '\0';
87 free(b);
88 return 0;
89 }
90
91 FILE *open_memstream(char **bufptr, size_t *lenptr)
92 {
93 struct Buffer *b = (struct Buffer *)malloc(sizeof(struct Buffer));
94 if (b == NULL)
95 return NULL;
96 b->alloc = 0;
97 b->len = lenptr;
98 b->ptr = bufptr;
99 *bufptr = NULL;
100 *lenptr = 0;
101
102 #ifdef __APPLE__
103 return funopen(b, NULL, write_to_buffer, NULL, close_buffer);
104 #elif __GLIBC__
105 static const cookie_io_functions_t vtable = {
106 NULL,
107 write_to_buffer,
108 NULL,
109 close_buffer
110 };
111 return fopencookie(b, "w", vtable);
112 #endif
113 }
114
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