1 /* $OpenBSD: strtonum.c,v 1.6 2004/08/03 19:38:01 millert Exp $ */
2
3 /*
4 * Copyright (c) 2004 Ted Unangst and Todd Miller
5 * All rights reserved.
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 #pragma ident "%Z%%M% %I% %E% SMI"
21
22 #include <errno.h>
23 #include <limits.h>
24 #include <stdlib.h>
25
26 #define INVALID 1
27 #define TOOSMALL 2
28 #define TOOLARGE 3
29
30 unsigned int
strtonum(const char * numstr,unsigned int minval,unsigned int maxval,const char ** errstrp)31 strtonum(const char *numstr, unsigned int minval, unsigned int maxval,
32 const char **errstrp)
33 {
34 long long ll = 0;
35 char *ep;
36 int error = 0;
37 struct errval {
38 const char *errstr;
39 int err;
40 } ev[4] = {
41 { NULL, 0 },
42 { "invalid", EINVAL },
43 { "too small", ERANGE },
44 { "too large", ERANGE },
45 };
46
47 ev[0].err = errno;
48 errno = 0;
49 if (minval > maxval)
50 error = INVALID;
51 else {
52 ll = strtoll(numstr, &ep, 10);
53 if (numstr == ep || *ep != '\0')
54 error = INVALID;
55 else if ((ll == LLONG_MIN && errno == ERANGE) || ll < minval)
56 error = TOOSMALL;
57 else if ((ll == LLONG_MAX && errno == ERANGE) || ll > maxval)
58 error = TOOLARGE;
59 }
60 if (errstrp != NULL)
61 *errstrp = ev[error].errstr;
62 errno = ev[error].err;
63 if (error)
64 ll = 0;
65
66 /*
67 * we have already checked boundaries above so we can safely
68 * convert return type here
69 */
70 return ((unsigned int)ll);
71 }
72