[src/trunk]: src/lib/libc/gen misc cleanups:

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/15908116aa7d
branches:  trunk
changeset: 777839:15908116aa7d
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Mar 05 19:40:08 2012 +0000

description:
misc cleanups:
- const for mibs
- #define for magic constants
- casts

diffstat:

 lib/libc/gen/arc4random.c |  31 ++++++++++++-------------------
 1 files changed, 12 insertions(+), 19 deletions(-)

diffs (106 lines):

diff -r fbd6e470f6fa -r 15908116aa7d lib/libc/gen/arc4random.c
--- a/lib/libc/gen/arc4random.c Mon Mar 05 16:53:59 2012 +0000
+++ b/lib/libc/gen/arc4random.c Mon Mar 05 19:40:08 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: arc4random.c,v 1.12 2012/03/04 00:36:43 tls Exp $      */
+/*     $NetBSD: arc4random.c,v 1.13 2012/03/05 19:40:08 christos Exp $ */
 /*     $OpenBSD: arc4random.c,v 1.6 2001/06/05 05:05:38 pvalchev Exp $ */
 
 /*
@@ -27,7 +27,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: arc4random.c,v 1.12 2012/03/04 00:36:43 tls Exp $");
+__RCSID("$NetBSD: arc4random.c,v 1.13 2012/03/05 19:40:08 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 
 #include "namespace.h"
@@ -44,12 +44,13 @@
 __weak_alias(arc4random,_arc4random)
 #endif
 
+#define RSIZE 256
 struct arc4_stream {
        mutex_t mtx;
        int initialized;
        uint8_t i;
        uint8_t j;
-       uint8_t s[256];
+       uint8_t s[RSIZE];
 };
 
 /* XXX lint explodes with an internal error if only mtx is initialized! */
@@ -64,9 +65,7 @@
 static inline void
 arc4_init(struct arc4_stream *as)
 {
-       int     n;
-
-       for (n = 0; n < 256; n++)
+       for (int n = 0; n < RSIZE; n++)
                as->s[n] = n;
        as->i = 0;
        as->j = 0;
@@ -78,11 +77,10 @@
 static inline void
 arc4_addrandom(struct arc4_stream *as, u_char *dat, int datlen)
 {
-       int     n;
        uint8_t si;
 
        as->i--;
-       for (n = 0; n < 256; n++) {
+       for (int n = 0; n < RSIZE; n++) {
                as->i = (as->i + 1);
                si = as->s[as->i];
                as->j = (as->j + si + dat[n % datlen]);
@@ -95,10 +93,8 @@
 static void
 arc4_stir(struct arc4_stream *as)
 {
-       int rdat[128 / sizeof(int)];
-       int     n;
-       int mib[2];
-       unsigned int i;
+       int rdat[32];
+       static const int mib[] = { CTL_KERN, KERN_URND };
        size_t len;
 
        /*
@@ -110,23 +106,20 @@
         * for us but much friendlier to other entropy consumers.
         */
 
-       mib[0] = CTL_KERN;
-       mib[1] = KERN_URND;
-
-       for (i = 0; i < sizeof(rdat) / sizeof(int); i++) {
+       for (size_t i = 0; i < __arraycount(rdat); i++) {
                len = sizeof(rdat[i]);
                if (sysctl(mib, 2, &rdat[i], &len, NULL, 0) == -1)
                        abort();
        }
 
-       arc4_addrandom(as, (void *) &rdat, sizeof(rdat));
+       arc4_addrandom(as, (void *) &rdat, (int)sizeof(rdat));
 
        /*
         * Throw away the first N words of output, as suggested in the
         * paper "Weaknesses in the Key Scheduling Algorithm of RC4"
         * by Fluher, Mantin, and Shamir.  (N = 256 in our case.)
         */
-       for (n = 0; n < 256 * 4; n++)
+       for (size_t j = 0; j < RSIZE * 4; j++)
                arc4_getbyte(as);
 }
 
@@ -284,7 +277,7 @@
                return 0;
 
 #if defined(ULONG_MAX) && (ULONG_MAX > 0xFFFFFFFFUL)
-       min = 0x100000000UL % upper_bound;
+       min = (uint32_t)(0x100000000U % upper_bound);
 #else
        /* calculate (2^32 % upper_bound) avoiding 64-bit math */
        if (upper_bound > 0x80000000U)