summaryrefslogtreecommitdiffstats
path: root/net/core/secure_seq.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /net/core/secure_seq.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/core/secure_seq.c')
-rw-r--r--net/core/secure_seq.c200
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..b0ff6153b
--- /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_aligned_key_t net_secret;
+static siphash_aligned_key_t ts_secret;
+
+#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