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[src/trunk]: src/sys/netinet6 netinet6: Mark randomid unused.
details: https://anonhg.NetBSD.org/src/rev/8a4d56a8249c
branches: trunk
changeset: 953376:8a4d56a8249c
user: christos <christos%NetBSD.org@localhost>
date: Sun Mar 07 14:59:36 2021 +0000
description:
netinet6: Mark randomid unused.
Will make merging and bisection easier if anything goes wrong with
flow label or fragment id randomization changes.
(from riastradh)
diffstat:
sys/netinet6/ip6_id.c | 245 ++++---------------------------------------------
1 files changed, 20 insertions(+), 225 deletions(-)
diffs (275 lines):
diff -r a82bd03650fe -r 8a4d56a8249c sys/netinet6/ip6_id.c
--- a/sys/netinet6/ip6_id.c Sun Mar 07 14:58:54 2021 +0000
+++ b/sys/netinet6/ip6_id.c Sun Mar 07 14:59:36 2021 +0000
@@ -1,9 +1,7 @@
-/* $NetBSD: ip6_id.c,v 1.19 2019/10/18 04:09:02 msaitoh Exp $ */
-/* $KAME: ip6_id.c,v 1.8 2003/09/06 13:41:06 itojun Exp $ */
-/* $OpenBSD: ip_id.c,v 1.6 2002/03/15 18:19:52 millert Exp $ */
+/* $NetBSD: ip6_id.c,v 1.20 2021/03/07 14:59:36 christos Exp $ */
-/*
- * Copyright (C) 2003 WIDE Project.
+/*-
+ * Copyright (c) 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -14,241 +12,38 @@
* 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. Neither the name of the project nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``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 PROJECT OR CONTRIBUTORS 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.
- */
-
-/*
- * 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.
*
- * 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 (bits - 1) bit
- * 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 = constant and a maximal period of m-1.
- *
- * The transaction id is determined by:
- * id[n] = seed xor (g^X[n] mod n)
- *
- * Effectively the id is restricted to the lower (bits - 1) bits, thus
- * yielding two different cycles by toggling the msb on and off.
- * This avoids reuse issues caused by reseeding.
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``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 FOUNDATION OR CONTRIBUTORS
+ * 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.
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ip6_id.c,v 1.19 2019/10/18 04:09:02 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ip6_id.c,v 1.20 2021/03/07 14:59:36 christos Exp $");
-#include <sys/param.h>
+#include <sys/types.h>
#include <sys/cprng.h>
-#include <lib/libkern/libkern.h>
-
-#include <net/if.h>
-#include <netinet/in.h>
-#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
-struct randomtab {
- const int ru_bits; /* resulting bits */
- const long ru_out; /* Time after wich will be reseeded */
- const u_int32_t ru_max; /* Uniq cycle, avoid blackjack prediction */
- const u_int32_t ru_gen; /* Starting generator */
- const u_int32_t ru_n; /* ru_n: prime, ru_n - 1: product of pfacts[] */
- const u_int32_t ru_agen; /* determine ru_a as ru_agen^(2*rand) */
- const u_int32_t ru_m; /* ru_m = 2^x*3^y */
- const u_int32_t ru_pfacts[4]; /* factors of ru_n */
-
- u_int32_t ru_counter;
- u_int32_t ru_msb;
-
- u_int32_t ru_x;
- u_int32_t ru_seed, ru_seed2;
- u_int32_t ru_a, ru_b;
- u_int32_t ru_g;
- long ru_reseed;
-};
-
-static struct randomtab randomtab_32 = {
- .ru_bits = 32, /* resulting bits */
- .ru_out = 180, /* Time after wich will be reseeded */
- .ru_max = 1000000000, /* Uniq cycle, avoid blackjack prediction */
- .ru_gen = 2, /* Starting generator */
- .ru_n = 2147483629, /* RU_N-1 = 2^2*3^2*59652323 */
- .ru_agen = 7, /* determine ru_a as RU_AGEN^(2*rand) */
- .ru_m = 1836660096, /* RU_M = 2^7*3^15 - don't change */
- .ru_pfacts = { 2, 3, 59652323, 0 }, /* factors of ru_n */
-};
-
-static struct randomtab randomtab_20 = {
- .ru_bits = 20, /* resulting bits */
- .ru_out = 180, /* Time after wich will be reseeded */
- .ru_max = 200000, /* Uniq cycle, avoid blackjack prediction */
- .ru_gen = 2, /* Starting generator */
- .ru_n = 524269, /* RU_N-1 = 2^2*3^2*14563 */
- .ru_agen = 7, /* determine ru_a as RU_AGEN^(2*rand) */
- .ru_m = 279936, /* RU_M = 2^7*3^7 - don't change */
- .ru_pfacts = { 2, 3, 14563, 0 }, /* factors of ru_n */
-};
-
-static u_int32_t pmod(u_int32_t, u_int32_t, u_int32_t);
-static void initid(struct randomtab *);
-static u_int32_t randomid(struct randomtab *);
-
-/*
- * 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 expo, u_int32_t mod)
-{
- u_int64_t s, t, u;
-
- s = 1;
- t = gen;
- u = expo;
-
- while (u) {
- if (u & 1)
- s = (s * t) % mod;
- u >>= 1;
- t = (t * t) % mod;
- }
- return (s);
-}
-
-/*
- * Initializes 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(struct randomtab *p)
-{
- u_int32_t j, i;
- int noprime = 1;
-
- p->ru_x = cprng_fast32() % p->ru_m;
-
- /* (bits - 1) bits of random seed */
- p->ru_seed = cprng_fast32() & (~0U >> (32 - p->ru_bits + 1));
- p->ru_seed2 = cprng_fast32() & (~0U >> (32 - p->ru_bits + 1));
-
- /* Determine the LCG we use */
- p->ru_b = (cprng_fast32() & (~0U >> (32 - p->ru_bits))) | 1;
- p->ru_a = pmod(p->ru_agen,
- (cprng_fast32() & (~0U >> (32 - p->ru_bits))) & (~1U), p->ru_m);
- while (p->ru_b % 3 == 0)
- p->ru_b += 2;
-
- j = cprng_fast32() % p->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; p->ru_pfacts[i] > 0; i++)
- if (j % p->ru_pfacts[i] == 0)
- break;
-
- if (p->ru_pfacts[i] == 0)
- noprime = 0;
- else
- j = (j + 1) % p->ru_n;
- }
-
- p->ru_g = pmod(p->ru_gen, j, p->ru_n);
- p->ru_counter = 0;
-
- p->ru_reseed = time_uptime + p->ru_out;
- p->ru_msb = p->ru_msb ? 0 : (1U << (p->ru_bits - 1));
-}
-
-static u_int32_t
-randomid(struct randomtab *p)
-{
- int i, n;
-
- if (p->ru_counter >= p->ru_max || time_uptime > p->ru_reseed)
- initid(p);
-
- /* Skip a random number of ids */
- n = cprng_fast32() & 0x3;
- if (p->ru_counter + n >= p->ru_max)
- initid(p);
-
- for (i = 0; i <= n; i++) {
- /* Linear Congruential Generator */
- p->ru_x = ((u_int64_t)p->ru_a * p->ru_x + p->ru_b) % p->ru_m;
- }
-
- p->ru_counter += i;
-
- return (p->ru_seed ^ pmod(p->ru_g, p->ru_seed2 + p->ru_x, p->ru_n)) |
- p->ru_msb;
-}
-
-u_int32_t
+uint32_t
ip6_randomid(void)
{
- return randomid(&randomtab_32);
+ return cprng_fast32();
}
-u_int32_t
+uint32_t
ip6_randomflowlabel(void)
{
- return randomid(&randomtab_20) & 0xfffff;
+ return cprng_fast32() & 0xfffff;
}
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