Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 200 insertions, 0 deletions

diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c
new file mode 100644
index 000000000..189eea137
--- /dev/null
+++ b/net/core/secure_seq.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/cache.h>
+#include <linux/random.h>
+#include <linux/hrtimer.h>
+#include <linux/ktime.h>
+#include <linux/string.h>
+#include <linux/net.h>
+#include <linux/siphash.h>
+#include <net/secure_seq.h>
+
+#if IS_ENABLED(CONFIG_IPV6) || IS_ENABLED(CONFIG_INET)
+#include <linux/in6.h>
+#include <net/tcp.h>
+
+static siphash_key_t net_secret __read_mostly;
+static siphash_key_t ts_secret __read_mostly;
+
+#define EPHEMERAL_PORT_SHUFFLE_PERIOD (10 * HZ)
+
+static __always_inline void net_secret_init(void)
+{
+	net_get_random_once(&net_secret, sizeof(net_secret));
+}
+
+static __always_inline void ts_secret_init(void)
+{
+	net_get_random_once(&ts_secret, sizeof(ts_secret));
+}
+#endif
+
+#ifdef CONFIG_INET
+static u32 seq_scale(u32 seq)
+{
+	/*
+	 *	As close as possible to RFC 793, which
+	 *	suggests using a 250 kHz clock.
+	 *	Further reading shows this assumes 2 Mb/s networks.
+	 *	For 10 Mb/s Ethernet, a 1 MHz clock is appropriate.
+	 *	For 10 Gb/s Ethernet, a 1 GHz clock should be ok, but
+	 *	we also need to limit the resolution so that the u32 seq
+	 *	overlaps less than one time per MSL (2 minutes).
+	 *	Choosing a clock of 64 ns period is OK. (period of 274 s)
+	 */
+	return seq + (ktime_get_real_ns() >> 6);
+}
+#endif
+
+#if IS_ENABLED(CONFIG_IPV6)
+u32 secure_tcpv6_ts_off(const struct net *net,
+			const __be32 *saddr, const __be32 *daddr)
+{
+	const struct {
+		struct in6_addr saddr;
+		struct in6_addr daddr;
+	} __aligned(SIPHASH_ALIGNMENT) combined = {
+		.saddr = *(struct in6_addr *)saddr,
+		.daddr = *(struct in6_addr *)daddr,
+	};
+
+	if (READ_ONCE(net->ipv4.sysctl_tcp_timestamps) != 1)
+		return 0;
+
+	ts_secret_init();
+	return siphash(&combined, offsetofend(typeof(combined), daddr),
+		       &ts_secret);
+}
+EXPORT_SYMBOL(secure_tcpv6_ts_off);
+
+u32 secure_tcpv6_seq(const __be32 *saddr, const __be32 *daddr,
+		     __be16 sport, __be16 dport)
+{
+	const struct {
+		struct in6_addr saddr;
+		struct in6_addr daddr;
+		__be16 sport;
+		__be16 dport;
+	} __aligned(SIPHASH_ALIGNMENT) combined = {
+		.saddr = *(struct in6_addr *)saddr,
+		.daddr = *(struct in6_addr *)daddr,
+		.sport = sport,
+		.dport = dport
+	};
+	u32 hash;
+
+	net_secret_init();
+	hash = siphash(&combined, offsetofend(typeof(combined), dport),
+		       &net_secret);
+	return seq_scale(hash);
+}
+EXPORT_SYMBOL(secure_tcpv6_seq);
+
+u64 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
+			       __be16 dport)
+{
+	const struct {
+		struct in6_addr saddr;
+		struct in6_addr daddr;
+		unsigned int timeseed;
+		__be16 dport;
+	} __aligned(SIPHASH_ALIGNMENT) combined = {
+		.saddr = *(struct in6_addr *)saddr,
+		.daddr = *(struct in6_addr *)daddr,
+		.timeseed = jiffies / EPHEMERAL_PORT_SHUFFLE_PERIOD,
+		.dport = dport,
+	};
+	net_secret_init();
+	return siphash(&combined, offsetofend(typeof(combined), dport),
+		       &net_secret);
+}
+EXPORT_SYMBOL(secure_ipv6_port_ephemeral);
+#endif
+
+#ifdef CONFIG_INET
+u32 secure_tcp_ts_off(const struct net *net, __be32 saddr, __be32 daddr)
+{
+	if (READ_ONCE(net->ipv4.sysctl_tcp_timestamps) != 1)
+		return 0;
+
+	ts_secret_init();
+	return siphash_2u32((__force u32)saddr, (__force u32)daddr,
+			    &ts_secret);
+}
+
+/* secure_tcp_seq_and_tsoff(a, b, 0, d) == secure_ipv4_port_ephemeral(a, b, d),
+ * but fortunately, `sport' cannot be 0 in any circumstances. If this changes,
+ * it would be easy enough to have the former function use siphash_4u32, passing
+ * the arguments as separate u32.
+ */
+u32 secure_tcp_seq(__be32 saddr, __be32 daddr,
+		   __be16 sport, __be16 dport)
+{
+	u32 hash;
+
+	net_secret_init();
+	hash = siphash_3u32((__force u32)saddr, (__force u32)daddr,
+			    (__force u32)sport << 16 | (__force u32)dport,
+			    &net_secret);
+	return seq_scale(hash);
+}
+EXPORT_SYMBOL_GPL(secure_tcp_seq);
+
+u64 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
+{
+	net_secret_init();
+	return siphash_4u32((__force u32)saddr, (__force u32)daddr,
+			    (__force u16)dport,
+			    jiffies / EPHEMERAL_PORT_SHUFFLE_PERIOD,
+			    &net_secret);
+}
+EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral);
+#endif
+
+#if IS_ENABLED(CONFIG_IP_DCCP)
+u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
+				__be16 sport, __be16 dport)
+{
+	u64 seq;
+	net_secret_init();
+	seq = siphash_3u32((__force u32)saddr, (__force u32)daddr,
+			   (__force u32)sport << 16 | (__force u32)dport,
+			   &net_secret);
+	seq += ktime_get_real_ns();
+	seq &= (1ull << 48) - 1;
+	return seq;
+}
+EXPORT_SYMBOL(secure_dccp_sequence_number);
+
+#if IS_ENABLED(CONFIG_IPV6)
+u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
+				  __be16 sport, __be16 dport)
+{
+	const struct {
+		struct in6_addr saddr;
+		struct in6_addr daddr;
+		__be16 sport;
+		__be16 dport;
+	} __aligned(SIPHASH_ALIGNMENT) combined = {
+		.saddr = *(struct in6_addr *)saddr,
+		.daddr = *(struct in6_addr *)daddr,
+		.sport = sport,
+		.dport = dport
+	};
+	u64 seq;
+	net_secret_init();
+	seq = siphash(&combined, offsetofend(typeof(combined), dport),
+		      &net_secret);
+	seq += ktime_get_real_ns();
+	seq &= (1ull << 48) - 1;
+	return seq;
+}
+EXPORT_SYMBOL(secure_dccpv6_sequence_number);
+#endif
+#endif