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[src/trunk]: src/lib/libc/rpc have __rpc_getxid.c
details: https://anonhg.NetBSD.org/src/rev/272794f007c6
branches: trunk
changeset: 551621:272794f007c6
user: itojun <itojun%NetBSD.org@localhost>
date: Tue Sep 09 03:56:23 2003 +0000
description:
have __rpc_getxid.c
diffstat:
lib/libc/rpc/Makefile.inc | 4 +-
lib/libc/rpc/__rpc_getxid.c | 196 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 198 insertions(+), 2 deletions(-)
diffs (218 lines):
diff -r e5b23b1044dd -r 272794f007c6 lib/libc/rpc/Makefile.inc
--- a/lib/libc/rpc/Makefile.inc Tue Sep 09 03:01:27 2003 +0000
+++ b/lib/libc/rpc/Makefile.inc Tue Sep 09 03:56:23 2003 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile.inc,v 1.14 2000/06/03 02:28:12 fvdl Exp $
+# $NetBSD: Makefile.inc,v 1.15 2003/09/09 03:56:23 itojun Exp $
# librpc sources
.PATH: ${.CURDIR}/arch/${MACHINE}/rpc ${.CURDIR}/rpc
@@ -14,7 +14,7 @@
svc.c svc_auth.c svc_dg.c svc_auth_unix.c svc_generic.c svc_raw.c \
svc_run.c svc_simple.c svc_vc.c \
xdr.c xdr_array.c xdr_float.c xdr_mem.c xdr_rec.c xdr_reference.c \
- xdr_stdio.c
+ xdr_stdio.c __rpc_getxid.c
CPPFLAGS+= -DPORTMAP
diff -r e5b23b1044dd -r 272794f007c6 lib/libc/rpc/__rpc_getxid.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libc/rpc/__rpc_getxid.c Tue Sep 09 03:56:23 2003 +0000
@@ -0,0 +1,196 @@
+/* $NetBSD: __rpc_getxid.c,v 1.1 2003/09/09 03:56:23 itojun Exp $ */
+/* $OpenBSD: ip_id.c,v 1.6 2002/03/15 18:19:52 millert Exp $ */
+
+/*
+ * Copyright 1998 Niels Provos <provos%citi.umich.edu@localhost>
+ * All rights reserved.
+ *
+ * Theo de Raadt <deraadt%openbsd.org@localhost> came up with the idea of using
+ * such a mathematical system to generate more random (yet non-repeating)
+ * ids to solve the resolver/named problem. But Niels designed the
+ * actual system based on the constraints.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by Niels Provos.
+ * 4. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * seed = random 31bit
+ * n = prime, g0 = generator to n,
+ * j = random so that gcd(j,n-1) == 1
+ * g = g0^j mod n will be a generator again.
+ *
+ * X[0] = random seed.
+ * X[n] = a*X[n-1]+b mod m is a Linear Congruential Generator
+ * with a = 7^(even random) mod m,
+ * b = random with gcd(b,m) == 1
+ * m = 1836660096 and a maximal period of m-1.
+ *
+ * The transaction id is determined by:
+ * id[n] = seed xor (g^X[n] mod n)
+ *
+ * Effectivly the id is restricted to the lower 31 bits, thus
+ * yielding two different cycles by toggling the msb on and off.
+ * This avoids reuse issues caused by reseeding.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: __rpc_getxid.c,v 1.1 2003/09/09 03:56:23 itojun Exp $");
+#endif
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <stdlib.h>
+#include <rpc/rpc.h>
+#include "rpc_internal.h"
+
+#define RU_OUT 180 /* Time after wich will be reseeded */
+#define RU_MAX 1000000000 /* Uniq cycle, avoid blackjack prediction */
+#define RU_GEN 2 /* Starting generator */
+#define RU_N 2147483629 /* RU_N-1 = 2^2*3^2*59652323 */
+#define RU_AGEN 7 /* determine ru_a as RU_AGEN^(2*rand) */
+#define RU_M 1836660096 /* RU_M = 2^7*3^15 - don't change */
+
+#define PFAC_N 3
+const static u_int32_t pfacts[PFAC_N] = {
+ 2,
+ 3,
+ 59652323
+};
+
+static u_int32_t ru_x;
+static u_int32_t ru_seed, ru_seed2;
+static u_int32_t ru_a, ru_b;
+static u_int32_t ru_g;
+static u_int32_t ru_counter = 0;
+static u_int32_t ru_msb = 0;
+static long ru_reseed;
+
+static u_int32_t pmod(u_int32_t, u_int32_t, u_int32_t);
+static void initid(void);
+
+/*
+ * Do a fast modular exponation, returned value will be in the range
+ * of 0 - (mod-1)
+ */
+static u_int32_t
+pmod(u_int32_t gen, u_int32_t exp, u_int32_t mod)
+{
+ u_int64_t s, t, u;
+
+ s = 1;
+ t = gen;
+ u = exp;
+
+ while (u) {
+ if (u & 1)
+ s = (s * t) % mod;
+ u >>= 1;
+ t = (t * t) % mod;
+ }
+ return ((u_int32_t)s & 0xffffffff);
+}
+
+/*
+ * Initalizes the seed and chooses a suitable generator. Also toggles
+ * the msb flag. The msb flag is used to generate two distinct
+ * cycles of random numbers and thus avoiding reuse of ids.
+ *
+ * This function is called from id_randomid() when needed, an
+ * application does not have to worry about it.
+ */
+static void
+initid(void)
+{
+ u_int32_t j, i;
+ int noprime = 1;
+ struct timeval tv;
+
+ ru_x = arc4random() % RU_M;
+
+ /* 31 bits of random seed */
+ ru_seed = arc4random() & INT32_MAX;
+ ru_seed2 = arc4random() & INT32_MAX;
+
+ /* Determine the LCG we use */
+ ru_b = arc4random() | 1;
+ ru_a = pmod(RU_AGEN, arc4random() & (~1U), RU_M);
+ while (ru_b % 3 == 0)
+ ru_b += 2;
+
+ j = arc4random() % RU_N;
+
+ /*
+ * Do a fast gcd(j,RU_N-1), so we can find a j with
+ * gcd(j, RU_N-1) == 1, giving a new generator for
+ * RU_GEN^j mod RU_N
+ */
+ while (noprime) {
+ for (i = 0; i < PFAC_N; i++)
+ if (j % pfacts[i] == 0)
+ break;
+
+ if (i >= PFAC_N)
+ noprime = 0;
+ else
+ j = (j + 1) % RU_N;
+ }
+
+ ru_g = pmod(RU_GEN, j, RU_N);
+ ru_counter = 0;
+
+ gettimeofday(&tv, NULL);
+ ru_reseed = tv.tv_sec + RU_OUT;
+ ru_msb = ru_msb ? 0 : 0x80000000;
+}
+
+u_int32_t
+__rpc_getxid(void)
+{
+ int i, n;
+ u_int32_t tmp;
+ struct timeval tv;
+
+ gettimeofday(&tv, NULL);
+ if (ru_counter >= RU_MAX || tv.tv_sec > ru_reseed)
+ initid();
+
+ tmp = arc4random();
+
+ /* Skip a random number of ids */
+ n = tmp & 0x3; tmp = tmp >> 2;
+ if (ru_counter + n >= RU_MAX)
+ initid();
+
+ for (i = 0; i <= n; i++) {
+ /* Linear Congruential Generator */
+ ru_x = (ru_a * ru_x + ru_b) % RU_M;
+ }
+
+ ru_counter += i;
+
+ return (ru_seed ^ pmod(ru_g, ru_seed2 ^ ru_x,RU_N)) | ru_msb;
+}
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