1 /* Convert characters in input buffer using conversion descriptor to
2    output buffer.
3    Copyright (C) 1997-2022 Free Software Foundation, Inc.
4    This file is part of the GNU C Library.
5 
6    The GNU C Library is free software; you can redistribute it and/or
7    modify it under the terms of the GNU Lesser General Public
8    License as published by the Free Software Foundation; either
9    version 2.1 of the License, or (at your option) any later version.
10 
11    The GNU C Library is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14    Lesser General Public License for more details.
15 
16    You should have received a copy of the GNU Lesser General Public
17    License along with the GNU C Library; if not, see
18    <https://www.gnu.org/licenses/>.  */
19 
20 #include <stddef.h> /* for NULL */
21 #include <errno.h>
22 #include <iconv.h>
23 
24 #include <gconv_int.h>
25 
26 #include <assert.h>
27 
28 
29 size_t
iconv(iconv_t cd,char ** inbuf,size_t * inbytesleft,char ** outbuf,size_t * outbytesleft)30 iconv (iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf,
31        size_t *outbytesleft)
32 {
33   __gconv_t gcd = (__gconv_t) cd;
34   char *outstart = outbuf ? *outbuf : NULL;
35   size_t irreversible;
36   int result;
37 
38   if (__glibc_unlikely (inbuf == NULL || *inbuf == NULL))
39     {
40       if (outbuf == NULL || *outbuf == NULL)
41 	result = __gconv (gcd, NULL, NULL, NULL, NULL, &irreversible);
42       else
43 	result = __gconv (gcd, NULL, NULL, (unsigned char **) outbuf,
44 			  (unsigned char *) (outstart + *outbytesleft),
45 			  &irreversible);
46     }
47   else
48     {
49       const char *instart = *inbuf;
50 
51       result = __gconv (gcd, (const unsigned char **) inbuf,
52 			(const unsigned char *)  (*inbuf + *inbytesleft),
53 			(unsigned char **) outbuf,
54 			(unsigned char *) (*outbuf + *outbytesleft),
55 			&irreversible);
56 
57       *inbytesleft -= *inbuf - instart;
58     }
59   if (outstart != NULL)
60     *outbytesleft -= *outbuf - outstart;
61 
62   switch (__builtin_expect (result, __GCONV_OK))
63     {
64     case __GCONV_ILLEGAL_DESCRIPTOR:
65       __set_errno (EBADF);
66       irreversible = (size_t) -1L;
67       break;
68 
69     case __GCONV_ILLEGAL_INPUT:
70       __set_errno (EILSEQ);
71       irreversible = (size_t) -1L;
72       break;
73 
74     case __GCONV_FULL_OUTPUT:
75       __set_errno (E2BIG);
76       irreversible = (size_t) -1L;
77       break;
78 
79     case __GCONV_INCOMPLETE_INPUT:
80       __set_errno (EINVAL);
81       irreversible = (size_t) -1L;
82       break;
83 
84     case __GCONV_EMPTY_INPUT:
85     case __GCONV_OK:
86       /* Nothing.  */
87       break;
88 
89     default:
90       assert (!"Nothing like this should happen");
91     }
92 
93   return irreversible;
94 }
95