[PATCH v5 3/3] Replace invocation of weak PRNG
From: david . keisarschm
Date: Sat Apr 15 2023 - 13:38:58 EST
From: David Keisar Schmidt <david.keisarschm@xxxxxxxxxxxxxxx>
The memory randomization of the virtual address space
of kernel memory regions (physical memory mapping, vmalloc & vmemmap) inside
arch/x86/mm/kaslr.c is based on the function prandom_bytes_state which uses
the prandom_u32 PRNG.
However, the seeding here is done by calling prandom_seed_state,
which effectively uses only 32bits of the seed, which means that observing ONE
region's offset (say 30 bits) can provide the attacker with 2 possible seeds
(from which the attacker can calculate the remaining two regions)
In order to fix it, we have replaced the two invocations of prandom_bytes_state and prandom_seed_state
with siphash, which is considered more secure.
Besides, the original code used the same pseudo-random number in every iteration, so to add some additional randomization
we call siphash every iteration, hashing the iteration index with the described key.
Signed-off-by: David Keisar Schmidt <david.keisarschm@xxxxxxxxxxxxxxx>
---
Changes since v4:
* replaced the call to prandom_bytes_state and prandom_seed_state,
with siphash.
Changes since v2:
* edited commit message.
arch/x86/mm/kaslr.c | 18 +-
include/uapi/linux/netfilter/xt_connmark.h | 40 +-
include/uapi/linux/netfilter/xt_dscp.h | 27 +-
include/uapi/linux/netfilter/xt_mark.h | 17 +-
include/uapi/linux/netfilter/xt_rateest.h | 38 +-
include/uapi/linux/netfilter/xt_tcpmss.h | 13 +-
include/uapi/linux/netfilter_ipv4/ipt_ecn.h | 40 +-
include/uapi/linux/netfilter_ipv4/ipt_ttl.h | 14 +-
include/uapi/linux/netfilter_ipv6/ip6t_hl.h | 14 +-
net/netfilter/xt_dscp.c | 149 ++++---
net/netfilter/xt_hl.c | 164 +++++---
net/netfilter/xt_rateest.c | 282 ++++++++-----
net/netfilter/xt_tcpmss.c | 378 ++++++++++++++----
...Z6.0+pooncelock+pooncelock+pombonce.litmus | 12 +-
14 files changed, 802 insertions(+), 404 deletions(-)
diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
index 557f0fe25..65714c917 100644
--- a/arch/x86/mm/kaslr.c
+++ b/arch/x86/mm/kaslr.c
@@ -25,6 +25,7 @@
#include <linux/random.h>
#include <linux/memblock.h>
#include <linux/pgtable.h>
+#include <linux/siphash.h>
#include <asm/setup.h>
#include <asm/kaslr.h>
@@ -66,9 +67,14 @@ void __init kernel_randomize_memory(void)
size_t i;
unsigned long vaddr_start, vaddr;
unsigned long rand, memory_tb;
- struct rnd_state rand_state;
unsigned long remain_entropy;
unsigned long vmemmap_size;
+ /*
+ * Create a Siphash key. We use a mask of PI digits to add some
+ * randomness to the key.
+ */
+ u64 seed = (u64) kaslr_get_random_long("Memory");
+ siphash_key_t key = {{seed, seed ^ 0x3141592653589793UL}};
vaddr_start = pgtable_l5_enabled() ? __PAGE_OFFSET_BASE_L5 : __PAGE_OFFSET_BASE_L4;
vaddr = vaddr_start;
@@ -112,9 +118,6 @@ void __init kernel_randomize_memory(void)
remain_entropy = vaddr_end - vaddr_start;
for (i = 0; i < ARRAY_SIZE(kaslr_regions); i++)
remain_entropy -= get_padding(&kaslr_regions[i]);
-
- prandom_seed_state(&rand_state, kaslr_get_random_long("Memory"));
-
for (i = 0; i < ARRAY_SIZE(kaslr_regions); i++) {
unsigned long entropy;
@@ -123,7 +126,12 @@ void __init kernel_randomize_memory(void)
* available.
*/
entropy = remain_entropy / (ARRAY_SIZE(kaslr_regions) - i);
- prandom_bytes_state(&rand_state, &rand, sizeof(rand));
+
+ /*
+ * Use Siphash to generate a pseudo-random number every
+ * iteration
+ * */
+ rand = siphash_1u64(i, &key);
entropy = (rand % (entropy + 1)) & PUD_MASK;
vaddr += entropy;
*kaslr_regions[i].base = vaddr;
diff --git a/include/uapi/linux/netfilter/xt_connmark.h b/include/uapi/linux/netfilter/xt_connmark.h
index 41b578ccd..36cc956ea 100644
--- a/include/uapi/linux/netfilter/xt_connmark.h
+++ b/include/uapi/linux/netfilter/xt_connmark.h
@@ -1,37 +1,7 @@
-/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
-/* Copyright (C) 2002,2004 MARA Systems AB <https://www.marasystems.com>
- * by Henrik Nordstrom <hno@xxxxxxxxxxxxxxx>
- */
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _XT_CONNMARK_H_target
+#define _XT_CONNMARK_H_target
-#ifndef _XT_CONNMARK_H
-#define _XT_CONNMARK_H
+#include <linux/netfilter/xt_connmark.h>
-#include <linux/types.h>
-
-enum {
- XT_CONNMARK_SET = 0,
- XT_CONNMARK_SAVE,
- XT_CONNMARK_RESTORE
-};
-
-enum {
- D_SHIFT_LEFT = 0,
- D_SHIFT_RIGHT,
-};
-
-struct xt_connmark_tginfo1 {
- __u32 ctmark, ctmask, nfmask;
- __u8 mode;
-};
-
-struct xt_connmark_tginfo2 {
- __u32 ctmark, ctmask, nfmask;
- __u8 shift_dir, shift_bits, mode;
-};
-
-struct xt_connmark_mtinfo1 {
- __u32 mark, mask;
- __u8 invert;
-};
-
-#endif /*_XT_CONNMARK_H*/
+#endif /*_XT_CONNMARK_H_target*/
diff --git a/include/uapi/linux/netfilter/xt_dscp.h b/include/uapi/linux/netfilter/xt_dscp.h
index 7594e4df8..223d635e8 100644
--- a/include/uapi/linux/netfilter/xt_dscp.h
+++ b/include/uapi/linux/netfilter/xt_dscp.h
@@ -1,32 +1,27 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/* x_tables module for matching the IPv4/IPv6 DSCP field
+/* x_tables module for setting the IPv4/IPv6 DSCP field
*
* (C) 2002 Harald Welte <laforge@xxxxxxxxxxxx>
+ * based on ipt_FTOS.c (C) 2000 by Matthew G. Marsh <mgm@xxxxxxxxxxxxx>
* This software is distributed under GNU GPL v2, 1991
*
* See RFC2474 for a description of the DSCP field within the IP Header.
*
- * xt_dscp.h,v 1.3 2002/08/05 19:00:21 laforge Exp
+ * xt_DSCP.h,v 1.7 2002/03/14 12:03:13 laforge Exp
*/
-#ifndef _XT_DSCP_H
-#define _XT_DSCP_H
-
+#ifndef _XT_DSCP_TARGET_H
+#define _XT_DSCP_TARGET_H
+#include <linux/netfilter/xt_dscp.h>
#include <linux/types.h>
-#define XT_DSCP_MASK 0xfc /* 11111100 */
-#define XT_DSCP_SHIFT 2
-#define XT_DSCP_MAX 0x3f /* 00111111 */
-
-/* match info */
-struct xt_dscp_info {
+/* target info */
+struct xt_DSCP_info {
__u8 dscp;
- __u8 invert;
};
-struct xt_tos_match_info {
- __u8 tos_mask;
+struct xt_tos_target_info {
__u8 tos_value;
- __u8 invert;
+ __u8 tos_mask;
};
-#endif /* _XT_DSCP_H */
+#endif /* _XT_DSCP_TARGET_H */
diff --git a/include/uapi/linux/netfilter/xt_mark.h b/include/uapi/linux/netfilter/xt_mark.h
index 9d0526ced..f1fe2b4be 100644
--- a/include/uapi/linux/netfilter/xt_mark.h
+++ b/include/uapi/linux/netfilter/xt_mark.h
@@ -1,16 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _XT_MARK_H
-#define _XT_MARK_H
+#ifndef _XT_MARK_H_target
+#define _XT_MARK_H_target
-#include <linux/types.h>
+#include <linux/netfilter/xt_mark.h>
-struct xt_mark_tginfo2 {
- __u32 mark, mask;
-};
-
-struct xt_mark_mtinfo1 {
- __u32 mark, mask;
- __u8 invert;
-};
-
-#endif /*_XT_MARK_H*/
+#endif /*_XT_MARK_H_target */
diff --git a/include/uapi/linux/netfilter/xt_rateest.h b/include/uapi/linux/netfilter/xt_rateest.h
index 52a37bdc1..2b87a71e6 100644
--- a/include/uapi/linux/netfilter/xt_rateest.h
+++ b/include/uapi/linux/netfilter/xt_rateest.h
@@ -1,39 +1,17 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _XT_RATEEST_MATCH_H
-#define _XT_RATEEST_MATCH_H
+#ifndef _XT_RATEEST_TARGET_H
+#define _XT_RATEEST_TARGET_H
#include <linux/types.h>
#include <linux/if.h>
-enum xt_rateest_match_flags {
- XT_RATEEST_MATCH_INVERT = 1<<0,
- XT_RATEEST_MATCH_ABS = 1<<1,
- XT_RATEEST_MATCH_REL = 1<<2,
- XT_RATEEST_MATCH_DELTA = 1<<3,
- XT_RATEEST_MATCH_BPS = 1<<4,
- XT_RATEEST_MATCH_PPS = 1<<5,
-};
-
-enum xt_rateest_match_mode {
- XT_RATEEST_MATCH_NONE,
- XT_RATEEST_MATCH_EQ,
- XT_RATEEST_MATCH_LT,
- XT_RATEEST_MATCH_GT,
-};
-
-struct xt_rateest_match_info {
- char name1[IFNAMSIZ];
- char name2[IFNAMSIZ];
- __u16 flags;
- __u16 mode;
- __u32 bps1;
- __u32 pps1;
- __u32 bps2;
- __u32 pps2;
+struct xt_rateest_target_info {
+ char name[IFNAMSIZ];
+ __s8 interval;
+ __u8 ewma_log;
/* Used internally by the kernel */
- struct xt_rateest *est1 __attribute__((aligned(8)));
- struct xt_rateest *est2 __attribute__((aligned(8)));
+ struct xt_rateest *est __attribute__((aligned(8)));
};
-#endif /* _XT_RATEEST_MATCH_H */
+#endif /* _XT_RATEEST_TARGET_H */
diff --git a/include/uapi/linux/netfilter/xt_tcpmss.h b/include/uapi/linux/netfilter/xt_tcpmss.h
index 2268f58b4..65ea6c9da 100644
--- a/include/uapi/linux/netfilter/xt_tcpmss.h
+++ b/include/uapi/linux/netfilter/xt_tcpmss.h
@@ -1,12 +1,13 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _XT_TCPMSS_MATCH_H
-#define _XT_TCPMSS_MATCH_H
+#ifndef _XT_TCPMSS_H
+#define _XT_TCPMSS_H
#include <linux/types.h>
-struct xt_tcpmss_match_info {
- __u16 mss_min, mss_max;
- __u8 invert;
+struct xt_tcpmss_info {
+ __u16 mss;
};
-#endif /*_XT_TCPMSS_MATCH_H*/
+#define XT_TCPMSS_CLAMP_PMTU 0xffff
+
+#endif /* _XT_TCPMSS_H */
diff --git a/include/uapi/linux/netfilter_ipv4/ipt_ecn.h b/include/uapi/linux/netfilter_ipv4/ipt_ecn.h
index 8121bec47..e3630fd04 100644
--- a/include/uapi/linux/netfilter_ipv4/ipt_ecn.h
+++ b/include/uapi/linux/netfilter_ipv4/ipt_ecn.h
@@ -1,16 +1,34 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _IPT_ECN_H
-#define _IPT_ECN_H
+/* Header file for iptables ipt_ECN target
+ *
+ * (C) 2002 by Harald Welte <laforge@xxxxxxxxxxxx>
+ *
+ * This software is distributed under GNU GPL v2, 1991
+ *
+ * ipt_ECN.h,v 1.3 2002/05/29 12:17:40 laforge Exp
+*/
+#ifndef _IPT_ECN_TARGET_H
+#define _IPT_ECN_TARGET_H
-#include <linux/netfilter/xt_ecn.h>
-#define ipt_ecn_info xt_ecn_info
+#include <linux/types.h>
+#include <linux/netfilter/xt_DSCP.h>
-enum {
- IPT_ECN_IP_MASK = XT_ECN_IP_MASK,
- IPT_ECN_OP_MATCH_IP = XT_ECN_OP_MATCH_IP,
- IPT_ECN_OP_MATCH_ECE = XT_ECN_OP_MATCH_ECE,
- IPT_ECN_OP_MATCH_CWR = XT_ECN_OP_MATCH_CWR,
- IPT_ECN_OP_MATCH_MASK = XT_ECN_OP_MATCH_MASK,
+#define IPT_ECN_IP_MASK (~XT_DSCP_MASK)
+
+#define IPT_ECN_OP_SET_IP 0x01 /* set ECN bits of IPv4 header */
+#define IPT_ECN_OP_SET_ECE 0x10 /* set ECE bit of TCP header */
+#define IPT_ECN_OP_SET_CWR 0x20 /* set CWR bit of TCP header */
+
+#define IPT_ECN_OP_MASK 0xce
+
+struct ipt_ECN_info {
+ __u8 operation; /* bitset of operations */
+ __u8 ip_ect; /* ECT codepoint of IPv4 header, pre-shifted */
+ union {
+ struct {
+ __u8 ece:1, cwr:1; /* TCP ECT bits */
+ } tcp;
+ } proto;
};
-#endif /* IPT_ECN_H */
+#endif /* _IPT_ECN_TARGET_H */
diff --git a/include/uapi/linux/netfilter_ipv4/ipt_ttl.h b/include/uapi/linux/netfilter_ipv4/ipt_ttl.h
index ad0226a86..57d2fc67a 100644
--- a/include/uapi/linux/netfilter_ipv4/ipt_ttl.h
+++ b/include/uapi/linux/netfilter_ipv4/ipt_ttl.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/* IP tables module for matching the value of the TTL
- * (C) 2000 by Harald Welte <laforge@xxxxxxxxxxxx> */
+/* TTL modification module for IP tables
+ * (C) 2000 by Harald Welte <laforge@xxxxxxxxxxxxx> */
#ifndef _IPT_TTL_H
#define _IPT_TTL_H
@@ -8,14 +8,14 @@
#include <linux/types.h>
enum {
- IPT_TTL_EQ = 0, /* equals */
- IPT_TTL_NE, /* not equals */
- IPT_TTL_LT, /* less than */
- IPT_TTL_GT, /* greater than */
+ IPT_TTL_SET = 0,
+ IPT_TTL_INC,
+ IPT_TTL_DEC
};
+#define IPT_TTL_MAXMODE IPT_TTL_DEC
-struct ipt_ttl_info {
+struct ipt_TTL_info {
__u8 mode;
__u8 ttl;
};
diff --git a/include/uapi/linux/netfilter_ipv6/ip6t_hl.h b/include/uapi/linux/netfilter_ipv6/ip6t_hl.h
index 6b62f9418..eaed56a28 100644
--- a/include/uapi/linux/netfilter_ipv6/ip6t_hl.h
+++ b/include/uapi/linux/netfilter_ipv6/ip6t_hl.h
@@ -1,7 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/* ip6tables module for matching the Hop Limit value
+/* Hop Limit modification module for ip6tables
* Maciej Soltysiak <solt@xxxxxxxxxxxxxxxxx>
- * Based on HW's ttl module */
+ * Based on HW's TTL module */
#ifndef _IP6T_HL_H
#define _IP6T_HL_H
@@ -9,14 +9,14 @@
#include <linux/types.h>
enum {
- IP6T_HL_EQ = 0, /* equals */
- IP6T_HL_NE, /* not equals */
- IP6T_HL_LT, /* less than */
- IP6T_HL_GT, /* greater than */
+ IP6T_HL_SET = 0,
+ IP6T_HL_INC,
+ IP6T_HL_DEC
};
+#define IP6T_HL_MAXMODE IP6T_HL_DEC
-struct ip6t_hl_info {
+struct ip6t_HL_info {
__u8 mode;
__u8 hop_limit;
};
diff --git a/net/netfilter/xt_dscp.c b/net/netfilter/xt_dscp.c
index fb0169a8f..cfa44515a 100644
--- a/net/netfilter/xt_dscp.c
+++ b/net/netfilter/xt_dscp.c
@@ -1,8 +1,11 @@
// SPDX-License-Identifier: GPL-2.0-only
-/* IP tables module for matching the value of the IPv4/IPv6 DSCP field
+/* x_tables module for setting the IPv4/IPv6 DSCP field, Version 1.8
*
* (C) 2002 by Harald Welte <laforge@xxxxxxxxxxxxx>
- */
+ * based on ipt_FTOS.c (C) 2000 by Matthew G. Marsh <mgm@xxxxxxxxxxxxx>
+ *
+ * See RFC2474 for a description of the DSCP field within the IP Header.
+*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
@@ -11,100 +14,148 @@
#include <net/dsfield.h>
#include <linux/netfilter/x_tables.h>
-#include <linux/netfilter/xt_dscp.h>
+#include <linux/netfilter/xt_DSCP.h>
MODULE_AUTHOR("Harald Welte <laforge@xxxxxxxxxxxxx>");
-MODULE_DESCRIPTION("Xtables: DSCP/TOS field match");
+MODULE_DESCRIPTION("Xtables: DSCP/TOS field modification");
MODULE_LICENSE("GPL");
-MODULE_ALIAS("ipt_dscp");
-MODULE_ALIAS("ip6t_dscp");
-MODULE_ALIAS("ipt_tos");
-MODULE_ALIAS("ip6t_tos");
+MODULE_ALIAS("ipt_DSCP");
+MODULE_ALIAS("ip6t_DSCP");
+MODULE_ALIAS("ipt_TOS");
+MODULE_ALIAS("ip6t_TOS");
+
+#define XT_DSCP_ECN_MASK 3u
-static bool
-dscp_mt(const struct sk_buff *skb, struct xt_action_param *par)
+static unsigned int
+dscp_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
- const struct xt_dscp_info *info = par->matchinfo;
+ const struct xt_DSCP_info *dinfo = par->targinfo;
u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
- return (dscp == info->dscp) ^ !!info->invert;
+ if (dscp != dinfo->dscp) {
+ if (skb_ensure_writable(skb, sizeof(struct iphdr)))
+ return NF_DROP;
+
+ ipv4_change_dsfield(ip_hdr(skb), XT_DSCP_ECN_MASK,
+ dinfo->dscp << XT_DSCP_SHIFT);
+
+ }
+ return XT_CONTINUE;
}
-static bool
-dscp_mt6(const struct sk_buff *skb, struct xt_action_param *par)
+static unsigned int
+dscp_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
- const struct xt_dscp_info *info = par->matchinfo;
+ const struct xt_DSCP_info *dinfo = par->targinfo;
u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
- return (dscp == info->dscp) ^ !!info->invert;
+ if (dscp != dinfo->dscp) {
+ if (skb_ensure_writable(skb, sizeof(struct ipv6hdr)))
+ return NF_DROP;
+
+ ipv6_change_dsfield(ipv6_hdr(skb), XT_DSCP_ECN_MASK,
+ dinfo->dscp << XT_DSCP_SHIFT);
+ }
+ return XT_CONTINUE;
}
-static int dscp_mt_check(const struct xt_mtchk_param *par)
+static int dscp_tg_check(const struct xt_tgchk_param *par)
{
- const struct xt_dscp_info *info = par->matchinfo;
+ const struct xt_DSCP_info *info = par->targinfo;
if (info->dscp > XT_DSCP_MAX)
return -EDOM;
-
return 0;
}
-static bool tos_mt(const struct sk_buff *skb, struct xt_action_param *par)
+static unsigned int
+tos_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
- const struct xt_tos_match_info *info = par->matchinfo;
-
- if (xt_family(par) == NFPROTO_IPV4)
- return ((ip_hdr(skb)->tos & info->tos_mask) ==
- info->tos_value) ^ !!info->invert;
- else
- return ((ipv6_get_dsfield(ipv6_hdr(skb)) & info->tos_mask) ==
- info->tos_value) ^ !!info->invert;
+ const struct xt_tos_target_info *info = par->targinfo;
+ struct iphdr *iph = ip_hdr(skb);
+ u_int8_t orig, nv;
+
+ orig = ipv4_get_dsfield(iph);
+ nv = (orig & ~info->tos_mask) ^ info->tos_value;
+
+ if (orig != nv) {
+ if (skb_ensure_writable(skb, sizeof(struct iphdr)))
+ return NF_DROP;
+ iph = ip_hdr(skb);
+ ipv4_change_dsfield(iph, 0, nv);
+ }
+
+ return XT_CONTINUE;
+}
+
+static unsigned int
+tos_tg6(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ const struct xt_tos_target_info *info = par->targinfo;
+ struct ipv6hdr *iph = ipv6_hdr(skb);
+ u_int8_t orig, nv;
+
+ orig = ipv6_get_dsfield(iph);
+ nv = (orig & ~info->tos_mask) ^ info->tos_value;
+
+ if (orig != nv) {
+ if (skb_ensure_writable(skb, sizeof(struct iphdr)))
+ return NF_DROP;
+ iph = ipv6_hdr(skb);
+ ipv6_change_dsfield(iph, 0, nv);
+ }
+
+ return XT_CONTINUE;
}
-static struct xt_match dscp_mt_reg[] __read_mostly = {
+static struct xt_target dscp_tg_reg[] __read_mostly = {
{
- .name = "dscp",
+ .name = "DSCP",
.family = NFPROTO_IPV4,
- .checkentry = dscp_mt_check,
- .match = dscp_mt,
- .matchsize = sizeof(struct xt_dscp_info),
+ .checkentry = dscp_tg_check,
+ .target = dscp_tg,
+ .targetsize = sizeof(struct xt_DSCP_info),
+ .table = "mangle",
.me = THIS_MODULE,
},
{
- .name = "dscp",
+ .name = "DSCP",
.family = NFPROTO_IPV6,
- .checkentry = dscp_mt_check,
- .match = dscp_mt6,
- .matchsize = sizeof(struct xt_dscp_info),
+ .checkentry = dscp_tg_check,
+ .target = dscp_tg6,
+ .targetsize = sizeof(struct xt_DSCP_info),
+ .table = "mangle",
.me = THIS_MODULE,
},
{
- .name = "tos",
+ .name = "TOS",
.revision = 1,
.family = NFPROTO_IPV4,
- .match = tos_mt,
- .matchsize = sizeof(struct xt_tos_match_info),
+ .table = "mangle",
+ .target = tos_tg,
+ .targetsize = sizeof(struct xt_tos_target_info),
.me = THIS_MODULE,
},
{
- .name = "tos",
+ .name = "TOS",
.revision = 1,
.family = NFPROTO_IPV6,
- .match = tos_mt,
- .matchsize = sizeof(struct xt_tos_match_info),
+ .table = "mangle",
+ .target = tos_tg6,
+ .targetsize = sizeof(struct xt_tos_target_info),
.me = THIS_MODULE,
},
};
-static int __init dscp_mt_init(void)
+static int __init dscp_tg_init(void)
{
- return xt_register_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
+ return xt_register_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg));
}
-static void __exit dscp_mt_exit(void)
+static void __exit dscp_tg_exit(void)
{
- xt_unregister_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
+ xt_unregister_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg));
}
-module_init(dscp_mt_init);
-module_exit(dscp_mt_exit);
+module_init(dscp_tg_init);
+module_exit(dscp_tg_exit);
diff --git a/net/netfilter/xt_hl.c b/net/netfilter/xt_hl.c
index c1a70f8f0..7873b834c 100644
--- a/net/netfilter/xt_hl.c
+++ b/net/netfilter/xt_hl.c
@@ -1,93 +1,159 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * IP tables module for matching the value of the TTL
- * (C) 2000,2001 by Harald Welte <laforge@xxxxxxxxxxxxx>
+ * TTL modification target for IP tables
+ * (C) 2000,2005 by Harald Welte <laforge@xxxxxxxxxxxxx>
*
- * Hop Limit matching module
- * (C) 2001-2002 Maciej Soltysiak <solt@xxxxxxxxxxxxxxxxx>
+ * Hop Limit modification target for ip6tables
+ * Maciej Soltysiak <solt@xxxxxxxxxxxxxxxxx>
*/
-
-#include <linux/ip.h>
-#include <linux/ipv6.h>
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/checksum.h>
#include <linux/netfilter/x_tables.h>
-#include <linux/netfilter_ipv4/ipt_ttl.h>
-#include <linux/netfilter_ipv6/ip6t_hl.h>
+#include <linux/netfilter_ipv4/ipt_TTL.h>
+#include <linux/netfilter_ipv6/ip6t_HL.h>
+MODULE_AUTHOR("Harald Welte <laforge@xxxxxxxxxxxxx>");
MODULE_AUTHOR("Maciej Soltysiak <solt@xxxxxxxxxxxxxxxxx>");
-MODULE_DESCRIPTION("Xtables: Hoplimit/TTL field match");
+MODULE_DESCRIPTION("Xtables: Hoplimit/TTL Limit field modification target");
MODULE_LICENSE("GPL");
-MODULE_ALIAS("ipt_ttl");
-MODULE_ALIAS("ip6t_hl");
-static bool ttl_mt(const struct sk_buff *skb, struct xt_action_param *par)
+static unsigned int
+ttl_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
- const struct ipt_ttl_info *info = par->matchinfo;
- const u8 ttl = ip_hdr(skb)->ttl;
+ struct iphdr *iph;
+ const struct ipt_TTL_info *info = par->targinfo;
+ int new_ttl;
+
+ if (skb_ensure_writable(skb, sizeof(*iph)))
+ return NF_DROP;
+
+ iph = ip_hdr(skb);
switch (info->mode) {
- case IPT_TTL_EQ:
- return ttl == info->ttl;
- case IPT_TTL_NE:
- return ttl != info->ttl;
- case IPT_TTL_LT:
- return ttl < info->ttl;
- case IPT_TTL_GT:
- return ttl > info->ttl;
+ case IPT_TTL_SET:
+ new_ttl = info->ttl;
+ break;
+ case IPT_TTL_INC:
+ new_ttl = iph->ttl + info->ttl;
+ if (new_ttl > 255)
+ new_ttl = 255;
+ break;
+ case IPT_TTL_DEC:
+ new_ttl = iph->ttl - info->ttl;
+ if (new_ttl < 0)
+ new_ttl = 0;
+ break;
+ default:
+ new_ttl = iph->ttl;
+ break;
}
- return false;
+ if (new_ttl != iph->ttl) {
+ csum_replace2(&iph->check, htons(iph->ttl << 8),
+ htons(new_ttl << 8));
+ iph->ttl = new_ttl;
+ }
+
+ return XT_CONTINUE;
}
-static bool hl_mt6(const struct sk_buff *skb, struct xt_action_param *par)
+static unsigned int
+hl_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
- const struct ip6t_hl_info *info = par->matchinfo;
- const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+ struct ipv6hdr *ip6h;
+ const struct ip6t_HL_info *info = par->targinfo;
+ int new_hl;
+
+ if (skb_ensure_writable(skb, sizeof(*ip6h)))
+ return NF_DROP;
+
+ ip6h = ipv6_hdr(skb);
switch (info->mode) {
- case IP6T_HL_EQ:
- return ip6h->hop_limit == info->hop_limit;
- case IP6T_HL_NE:
- return ip6h->hop_limit != info->hop_limit;
- case IP6T_HL_LT:
- return ip6h->hop_limit < info->hop_limit;
- case IP6T_HL_GT:
- return ip6h->hop_limit > info->hop_limit;
+ case IP6T_HL_SET:
+ new_hl = info->hop_limit;
+ break;
+ case IP6T_HL_INC:
+ new_hl = ip6h->hop_limit + info->hop_limit;
+ if (new_hl > 255)
+ new_hl = 255;
+ break;
+ case IP6T_HL_DEC:
+ new_hl = ip6h->hop_limit - info->hop_limit;
+ if (new_hl < 0)
+ new_hl = 0;
+ break;
+ default:
+ new_hl = ip6h->hop_limit;
+ break;
}
- return false;
+ ip6h->hop_limit = new_hl;
+
+ return XT_CONTINUE;
+}
+
+static int ttl_tg_check(const struct xt_tgchk_param *par)
+{
+ const struct ipt_TTL_info *info = par->targinfo;
+
+ if (info->mode > IPT_TTL_MAXMODE)
+ return -EINVAL;
+ if (info->mode != IPT_TTL_SET && info->ttl == 0)
+ return -EINVAL;
+ return 0;
+}
+
+static int hl_tg6_check(const struct xt_tgchk_param *par)
+{
+ const struct ip6t_HL_info *info = par->targinfo;
+
+ if (info->mode > IP6T_HL_MAXMODE)
+ return -EINVAL;
+ if (info->mode != IP6T_HL_SET && info->hop_limit == 0)
+ return -EINVAL;
+ return 0;
}
-static struct xt_match hl_mt_reg[] __read_mostly = {
+static struct xt_target hl_tg_reg[] __read_mostly = {
{
- .name = "ttl",
+ .name = "TTL",
.revision = 0,
.family = NFPROTO_IPV4,
- .match = ttl_mt,
- .matchsize = sizeof(struct ipt_ttl_info),
+ .target = ttl_tg,
+ .targetsize = sizeof(struct ipt_TTL_info),
+ .table = "mangle",
+ .checkentry = ttl_tg_check,
.me = THIS_MODULE,
},
{
- .name = "hl",
+ .name = "HL",
.revision = 0,
.family = NFPROTO_IPV6,
- .match = hl_mt6,
- .matchsize = sizeof(struct ip6t_hl_info),
+ .target = hl_tg6,
+ .targetsize = sizeof(struct ip6t_HL_info),
+ .table = "mangle",
+ .checkentry = hl_tg6_check,
.me = THIS_MODULE,
},
};
-static int __init hl_mt_init(void)
+static int __init hl_tg_init(void)
{
- return xt_register_matches(hl_mt_reg, ARRAY_SIZE(hl_mt_reg));
+ return xt_register_targets(hl_tg_reg, ARRAY_SIZE(hl_tg_reg));
}
-static void __exit hl_mt_exit(void)
+static void __exit hl_tg_exit(void)
{
- xt_unregister_matches(hl_mt_reg, ARRAY_SIZE(hl_mt_reg));
+ xt_unregister_targets(hl_tg_reg, ARRAY_SIZE(hl_tg_reg));
}
-module_init(hl_mt_init);
-module_exit(hl_mt_exit);
+module_init(hl_tg_init);
+module_exit(hl_tg_exit);
+MODULE_ALIAS("ipt_TTL");
+MODULE_ALIAS("ip6t_HL");
diff --git a/net/netfilter/xt_rateest.c b/net/netfilter/xt_rateest.c
index 72324bd97..80f6624e2 100644
--- a/net/netfilter/xt_rateest.c
+++ b/net/netfilter/xt_rateest.c
@@ -5,149 +5,229 @@
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/gen_stats.h>
+#include <linux/jhash.h>
+#include <linux/rtnetlink.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <net/gen_stats.h>
+#include <net/netlink.h>
+#include <net/netns/generic.h>
#include <linux/netfilter/x_tables.h>
-#include <linux/netfilter/xt_rateest.h>
+#include <linux/netfilter/xt_RATEEST.h>
#include <net/netfilter/xt_rateest.h>
+#define RATEEST_HSIZE 16
-static bool
-xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par)
+struct xt_rateest_net {
+ struct mutex hash_lock;
+ struct hlist_head hash[RATEEST_HSIZE];
+};
+
+static unsigned int xt_rateest_id;
+
+static unsigned int jhash_rnd __read_mostly;
+
+static unsigned int xt_rateest_hash(const char *name)
{
- const struct xt_rateest_match_info *info = par->matchinfo;
- struct gnet_stats_rate_est64 sample = {0};
- u_int32_t bps1, bps2, pps1, pps2;
- bool ret = true;
-
- gen_estimator_read(&info->est1->rate_est, &sample);
-
- if (info->flags & XT_RATEEST_MATCH_DELTA) {
- bps1 = info->bps1 >= sample.bps ? info->bps1 - sample.bps : 0;
- pps1 = info->pps1 >= sample.pps ? info->pps1 - sample.pps : 0;
- } else {
- bps1 = sample.bps;
- pps1 = sample.pps;
- }
+ return jhash(name, sizeof_field(struct xt_rateest, name), jhash_rnd) &
+ (RATEEST_HSIZE - 1);
+}
+
+static void xt_rateest_hash_insert(struct xt_rateest_net *xn,
+ struct xt_rateest *est)
+{
+ unsigned int h;
+
+ h = xt_rateest_hash(est->name);
+ hlist_add_head(&est->list, &xn->hash[h]);
+}
- if (info->flags & XT_RATEEST_MATCH_ABS) {
- bps2 = info->bps2;
- pps2 = info->pps2;
- } else {
- gen_estimator_read(&info->est2->rate_est, &sample);
-
- if (info->flags & XT_RATEEST_MATCH_DELTA) {
- bps2 = info->bps2 >= sample.bps ? info->bps2 - sample.bps : 0;
- pps2 = info->pps2 >= sample.pps ? info->pps2 - sample.pps : 0;
- } else {
- bps2 = sample.bps;
- pps2 = sample.pps;
+static struct xt_rateest *__xt_rateest_lookup(struct xt_rateest_net *xn,
+ const char *name)
+{
+ struct xt_rateest *est;
+ unsigned int h;
+
+ h = xt_rateest_hash(name);
+ hlist_for_each_entry(est, &xn->hash[h], list) {
+ if (strcmp(est->name, name) == 0) {
+ est->refcnt++;
+ return est;
}
}
- switch (info->mode) {
- case XT_RATEEST_MATCH_LT:
- if (info->flags & XT_RATEEST_MATCH_BPS)
- ret &= bps1 < bps2;
- if (info->flags & XT_RATEEST_MATCH_PPS)
- ret &= pps1 < pps2;
- break;
- case XT_RATEEST_MATCH_GT:
- if (info->flags & XT_RATEEST_MATCH_BPS)
- ret &= bps1 > bps2;
- if (info->flags & XT_RATEEST_MATCH_PPS)
- ret &= pps1 > pps2;
- break;
- case XT_RATEEST_MATCH_EQ:
- if (info->flags & XT_RATEEST_MATCH_BPS)
- ret &= bps1 == bps2;
- if (info->flags & XT_RATEEST_MATCH_PPS)
- ret &= pps1 == pps2;
- break;
- }
+ return NULL;
+}
- ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
- return ret;
+struct xt_rateest *xt_rateest_lookup(struct net *net, const char *name)
+{
+ struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
+ struct xt_rateest *est;
+
+ mutex_lock(&xn->hash_lock);
+ est = __xt_rateest_lookup(xn, name);
+ mutex_unlock(&xn->hash_lock);
+ return est;
}
+EXPORT_SYMBOL_GPL(xt_rateest_lookup);
-static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
+void xt_rateest_put(struct net *net, struct xt_rateest *est)
{
- struct xt_rateest_match_info *info = par->matchinfo;
- struct xt_rateest *est1, *est2;
- int ret = -EINVAL;
+ struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
+
+ mutex_lock(&xn->hash_lock);
+ if (--est->refcnt == 0) {
+ hlist_del(&est->list);
+ gen_kill_estimator(&est->rate_est);
+ /*
+ * gen_estimator est_timer() might access est->lock or bstats,
+ * wait a RCU grace period before freeing 'est'
+ */
+ kfree_rcu(est, rcu);
+ }
+ mutex_unlock(&xn->hash_lock);
+}
+EXPORT_SYMBOL_GPL(xt_rateest_put);
- if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
- XT_RATEEST_MATCH_REL)) != 1)
- goto err1;
+static unsigned int
+xt_rateest_tg(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ const struct xt_rateest_target_info *info = par->targinfo;
+ struct gnet_stats_basic_sync *stats = &info->est->bstats;
- if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
- goto err1;
+ spin_lock_bh(&info->est->lock);
+ u64_stats_add(&stats->bytes, skb->len);
+ u64_stats_inc(&stats->packets);
+ spin_unlock_bh(&info->est->lock);
- switch (info->mode) {
- case XT_RATEEST_MATCH_EQ:
- case XT_RATEEST_MATCH_LT:
- case XT_RATEEST_MATCH_GT:
- break;
- default:
- goto err1;
+ return XT_CONTINUE;
+}
+
+static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
+{
+ struct xt_rateest_net *xn = net_generic(par->net, xt_rateest_id);
+ struct xt_rateest_target_info *info = par->targinfo;
+ struct xt_rateest *est;
+ struct {
+ struct nlattr opt;
+ struct gnet_estimator est;
+ } cfg;
+ int ret;
+
+ if (strnlen(info->name, sizeof(est->name)) >= sizeof(est->name))
+ return -ENAMETOOLONG;
+
+ net_get_random_once(&jhash_rnd, sizeof(jhash_rnd));
+
+ mutex_lock(&xn->hash_lock);
+ est = __xt_rateest_lookup(xn, info->name);
+ if (est) {
+ mutex_unlock(&xn->hash_lock);
+ /*
+ * If estimator parameters are specified, they must match the
+ * existing estimator.
+ */
+ if ((!info->interval && !info->ewma_log) ||
+ (info->interval != est->params.interval ||
+ info->ewma_log != est->params.ewma_log)) {
+ xt_rateest_put(par->net, est);
+ return -EINVAL;
+ }
+ info->est = est;
+ return 0;
}
- ret = -ENOENT;
- est1 = xt_rateest_lookup(par->net, info->name1);
- if (!est1)
+ ret = -ENOMEM;
+ est = kzalloc(sizeof(*est), GFP_KERNEL);
+ if (!est)
goto err1;
- est2 = NULL;
- if (info->flags & XT_RATEEST_MATCH_REL) {
- est2 = xt_rateest_lookup(par->net, info->name2);
- if (!est2)
- goto err2;
- }
-
- info->est1 = est1;
- info->est2 = est2;
+ gnet_stats_basic_sync_init(&est->bstats);
+ strscpy(est->name, info->name, sizeof(est->name));
+ spin_lock_init(&est->lock);
+ est->refcnt = 1;
+ est->params.interval = info->interval;
+ est->params.ewma_log = info->ewma_log;
+
+ cfg.opt.nla_len = nla_attr_size(sizeof(cfg.est));
+ cfg.opt.nla_type = TCA_STATS_RATE_EST;
+ cfg.est.interval = info->interval;
+ cfg.est.ewma_log = info->ewma_log;
+
+ ret = gen_new_estimator(&est->bstats, NULL, &est->rate_est,
+ &est->lock, NULL, &cfg.opt);
+ if (ret < 0)
+ goto err2;
+
+ info->est = est;
+ xt_rateest_hash_insert(xn, est);
+ mutex_unlock(&xn->hash_lock);
return 0;
err2:
- xt_rateest_put(par->net, est1);
+ kfree(est);
err1:
+ mutex_unlock(&xn->hash_lock);
return ret;
}
-static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)
+static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par)
{
- struct xt_rateest_match_info *info = par->matchinfo;
+ struct xt_rateest_target_info *info = par->targinfo;
- xt_rateest_put(par->net, info->est1);
- if (info->est2)
- xt_rateest_put(par->net, info->est2);
+ xt_rateest_put(par->net, info->est);
}
-static struct xt_match xt_rateest_mt_reg __read_mostly = {
- .name = "rateest",
+static struct xt_target xt_rateest_tg_reg __read_mostly = {
+ .name = "RATEEST",
.revision = 0,
.family = NFPROTO_UNSPEC,
- .match = xt_rateest_mt,
- .checkentry = xt_rateest_mt_checkentry,
- .destroy = xt_rateest_mt_destroy,
- .matchsize = sizeof(struct xt_rateest_match_info),
- .usersize = offsetof(struct xt_rateest_match_info, est1),
+ .target = xt_rateest_tg,
+ .checkentry = xt_rateest_tg_checkentry,
+ .destroy = xt_rateest_tg_destroy,
+ .targetsize = sizeof(struct xt_rateest_target_info),
+ .usersize = offsetof(struct xt_rateest_target_info, est),
.me = THIS_MODULE,
};
-static int __init xt_rateest_mt_init(void)
+static __net_init int xt_rateest_net_init(struct net *net)
{
- return xt_register_match(&xt_rateest_mt_reg);
+ struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
+ int i;
+
+ mutex_init(&xn->hash_lock);
+ for (i = 0; i < ARRAY_SIZE(xn->hash); i++)
+ INIT_HLIST_HEAD(&xn->hash[i]);
+ return 0;
}
-static void __exit xt_rateest_mt_fini(void)
+static struct pernet_operations xt_rateest_net_ops = {
+ .init = xt_rateest_net_init,
+ .id = &xt_rateest_id,
+ .size = sizeof(struct xt_rateest_net),
+};
+
+static int __init xt_rateest_tg_init(void)
{
- xt_unregister_match(&xt_rateest_mt_reg);
+ int err = register_pernet_subsys(&xt_rateest_net_ops);
+
+ if (err)
+ return err;
+ return xt_register_target(&xt_rateest_tg_reg);
}
+static void __exit xt_rateest_tg_fini(void)
+{
+ xt_unregister_target(&xt_rateest_tg_reg);
+ unregister_pernet_subsys(&xt_rateest_net_ops);
+}
+
+
MODULE_AUTHOR("Patrick McHardy <kaber@xxxxxxxxx>");
MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("xtables rate estimator match");
-MODULE_ALIAS("ipt_rateest");
-MODULE_ALIAS("ip6t_rateest");
-module_init(xt_rateest_mt_init);
-module_exit(xt_rateest_mt_fini);
+MODULE_DESCRIPTION("Xtables: packet rate estimator");
+MODULE_ALIAS("ipt_RATEEST");
+MODULE_ALIAS("ip6t_RATEEST");
+module_init(xt_rateest_tg_init);
+module_exit(xt_rateest_tg_fini);
diff --git a/net/netfilter/xt_tcpmss.c b/net/netfilter/xt_tcpmss.c
index 37704ab01..116a885ad 100644
--- a/net/netfilter/xt_tcpmss.c
+++ b/net/netfilter/xt_tcpmss.c
@@ -1,107 +1,345 @@
// SPDX-License-Identifier: GPL-2.0-only
-/* Kernel module to match TCP MSS values. */
-
-/* Copyright (C) 2000 Marc Boucher <marc@xxxxxxx>
- * Portions (C) 2005 by Harald Welte <laforge@xxxxxxxxxxxxx>
+/*
+ * This is a module which is used for setting the MSS option in TCP packets.
+ *
+ * Copyright (C) 2000 Marc Boucher <marc@xxxxxxx>
+ * Copyright (C) 2007 Patrick McHardy <kaber@xxxxxxxxx>
*/
-
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/gfp.h>
+#include <linux/ipv6.h>
+#include <linux/tcp.h>
+#include <net/dst.h>
+#include <net/flow.h>
+#include <net/ipv6.h>
+#include <net/route.h>
#include <net/tcp.h>
-#include <linux/netfilter/xt_tcpmss.h>
-#include <linux/netfilter/x_tables.h>
-
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_tcpudp.h>
+#include <linux/netfilter/xt_TCPMSS.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <marc@xxxxxxx>");
-MODULE_DESCRIPTION("Xtables: TCP MSS match");
-MODULE_ALIAS("ipt_tcpmss");
-MODULE_ALIAS("ip6t_tcpmss");
+MODULE_DESCRIPTION("Xtables: TCP Maximum Segment Size (MSS) adjustment");
+MODULE_ALIAS("ipt_TCPMSS");
+MODULE_ALIAS("ip6t_TCPMSS");
-static bool
-tcpmss_mt(const struct sk_buff *skb, struct xt_action_param *par)
+static inline unsigned int
+optlen(const u_int8_t *opt, unsigned int offset)
{
- const struct xt_tcpmss_match_info *info = par->matchinfo;
- const struct tcphdr *th;
- struct tcphdr _tcph;
- /* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
- const u_int8_t *op;
- u8 _opt[15 * 4 - sizeof(_tcph)];
- unsigned int i, optlen;
-
- /* If we don't have the whole header, drop packet. */
- th = skb_header_pointer(skb, par->thoff, sizeof(_tcph), &_tcph);
- if (th == NULL)
- goto dropit;
-
- /* Malformed. */
- if (th->doff*4 < sizeof(*th))
- goto dropit;
-
- optlen = th->doff*4 - sizeof(*th);
- if (!optlen)
- goto out;
-
- /* Truncated options. */
- op = skb_header_pointer(skb, par->thoff + sizeof(*th), optlen, _opt);
- if (op == NULL)
- goto dropit;
-
- for (i = 0; i < optlen; ) {
- if (op[i] == TCPOPT_MSS
- && (optlen - i) >= TCPOLEN_MSS
- && op[i+1] == TCPOLEN_MSS) {
- u_int16_t mssval;
-
- mssval = (op[i+2] << 8) | op[i+3];
-
- return (mssval >= info->mss_min &&
- mssval <= info->mss_max) ^ info->invert;
+ /* Beware zero-length options: make finite progress */
+ if (opt[offset] <= TCPOPT_NOP || opt[offset+1] == 0)
+ return 1;
+ else
+ return opt[offset+1];
+}
+
+static u_int32_t tcpmss_reverse_mtu(struct net *net,
+ const struct sk_buff *skb,
+ unsigned int family)
+{
+ struct flowi fl;
+ struct rtable *rt = NULL;
+ u_int32_t mtu = ~0U;
+
+ if (family == PF_INET) {
+ struct flowi4 *fl4 = &fl.u.ip4;
+ memset(fl4, 0, sizeof(*fl4));
+ fl4->daddr = ip_hdr(skb)->saddr;
+ } else {
+ struct flowi6 *fl6 = &fl.u.ip6;
+
+ memset(fl6, 0, sizeof(*fl6));
+ fl6->daddr = ipv6_hdr(skb)->saddr;
+ }
+
+ nf_route(net, (struct dst_entry **)&rt, &fl, false, family);
+ if (rt != NULL) {
+ mtu = dst_mtu(&rt->dst);
+ dst_release(&rt->dst);
+ }
+ return mtu;
+}
+
+static int
+tcpmss_mangle_packet(struct sk_buff *skb,
+ const struct xt_action_param *par,
+ unsigned int family,
+ unsigned int tcphoff,
+ unsigned int minlen)
+{
+ const struct xt_tcpmss_info *info = par->targinfo;
+ struct tcphdr *tcph;
+ int len, tcp_hdrlen;
+ unsigned int i;
+ __be16 oldval;
+ u16 newmss;
+ u8 *opt;
+
+ /* This is a fragment, no TCP header is available */
+ if (par->fragoff != 0)
+ return 0;
+
+ if (skb_ensure_writable(skb, skb->len))
+ return -1;
+
+ len = skb->len - tcphoff;
+ if (len < (int)sizeof(struct tcphdr))
+ return -1;
+
+ tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff);
+ tcp_hdrlen = tcph->doff * 4;
+
+ if (len < tcp_hdrlen || tcp_hdrlen < sizeof(struct tcphdr))
+ return -1;
+
+ if (info->mss == XT_TCPMSS_CLAMP_PMTU) {
+ struct net *net = xt_net(par);
+ unsigned int in_mtu = tcpmss_reverse_mtu(net, skb, family);
+ unsigned int min_mtu = min(dst_mtu(skb_dst(skb)), in_mtu);
+
+ if (min_mtu <= minlen) {
+ net_err_ratelimited("unknown or invalid path-MTU (%u)\n",
+ min_mtu);
+ return -1;
+ }
+ newmss = min_mtu - minlen;
+ } else
+ newmss = info->mss;
+
+ opt = (u_int8_t *)tcph;
+ for (i = sizeof(struct tcphdr); i <= tcp_hdrlen - TCPOLEN_MSS; i += optlen(opt, i)) {
+ if (opt[i] == TCPOPT_MSS && opt[i+1] == TCPOLEN_MSS) {
+ u_int16_t oldmss;
+
+ oldmss = (opt[i+2] << 8) | opt[i+3];
+
+ /* Never increase MSS, even when setting it, as
+ * doing so results in problems for hosts that rely
+ * on MSS being set correctly.
+ */
+ if (oldmss <= newmss)
+ return 0;
+
+ opt[i+2] = (newmss & 0xff00) >> 8;
+ opt[i+3] = newmss & 0x00ff;
+
+ inet_proto_csum_replace2(&tcph->check, skb,
+ htons(oldmss), htons(newmss),
+ false);
+ return 0;
}
- if (op[i] < 2)
- i++;
- else
- i += op[i+1] ? : 1;
}
-out:
- return info->invert;
-dropit:
- par->hotdrop = true;
+ /* There is data after the header so the option can't be added
+ * without moving it, and doing so may make the SYN packet
+ * itself too large. Accept the packet unmodified instead.
+ */
+ if (len > tcp_hdrlen)
+ return 0;
+
+ /* tcph->doff has 4 bits, do not wrap it to 0 */
+ if (tcp_hdrlen >= 15 * 4)
+ return 0;
+
+ /*
+ * MSS Option not found ?! add it..
+ */
+ if (skb_tailroom(skb) < TCPOLEN_MSS) {
+ if (pskb_expand_head(skb, 0,
+ TCPOLEN_MSS - skb_tailroom(skb),
+ GFP_ATOMIC))
+ return -1;
+ tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff);
+ }
+
+ skb_put(skb, TCPOLEN_MSS);
+
+ /*
+ * IPv4: RFC 1122 states "If an MSS option is not received at
+ * connection setup, TCP MUST assume a default send MSS of 536".
+ * IPv6: RFC 2460 states IPv6 has a minimum MTU of 1280 and a minimum
+ * length IPv6 header of 60, ergo the default MSS value is 1220
+ * Since no MSS was provided, we must use the default values
+ */
+ if (xt_family(par) == NFPROTO_IPV4)
+ newmss = min(newmss, (u16)536);
+ else
+ newmss = min(newmss, (u16)1220);
+
+ opt = (u_int8_t *)tcph + sizeof(struct tcphdr);
+ memmove(opt + TCPOLEN_MSS, opt, len - sizeof(struct tcphdr));
+
+ inet_proto_csum_replace2(&tcph->check, skb,
+ htons(len), htons(len + TCPOLEN_MSS), true);
+ opt[0] = TCPOPT_MSS;
+ opt[1] = TCPOLEN_MSS;
+ opt[2] = (newmss & 0xff00) >> 8;
+ opt[3] = newmss & 0x00ff;
+
+ inet_proto_csum_replace4(&tcph->check, skb, 0, *((__be32 *)opt), false);
+
+ oldval = ((__be16 *)tcph)[6];
+ tcph->doff += TCPOLEN_MSS/4;
+ inet_proto_csum_replace2(&tcph->check, skb,
+ oldval, ((__be16 *)tcph)[6], false);
+ return TCPOLEN_MSS;
+}
+
+static unsigned int
+tcpmss_tg4(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ struct iphdr *iph = ip_hdr(skb);
+ __be16 newlen;
+ int ret;
+
+ ret = tcpmss_mangle_packet(skb, par,
+ PF_INET,
+ iph->ihl * 4,
+ sizeof(*iph) + sizeof(struct tcphdr));
+ if (ret < 0)
+ return NF_DROP;
+ if (ret > 0) {
+ iph = ip_hdr(skb);
+ newlen = htons(ntohs(iph->tot_len) + ret);
+ csum_replace2(&iph->check, iph->tot_len, newlen);
+ iph->tot_len = newlen;
+ }
+ return XT_CONTINUE;
+}
+
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+static unsigned int
+tcpmss_tg6(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ u8 nexthdr;
+ __be16 frag_off, oldlen, newlen;
+ int tcphoff;
+ int ret;
+
+ nexthdr = ipv6h->nexthdr;
+ tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr, &frag_off);
+ if (tcphoff < 0)
+ return NF_DROP;
+ ret = tcpmss_mangle_packet(skb, par,
+ PF_INET6,
+ tcphoff,
+ sizeof(*ipv6h) + sizeof(struct tcphdr));
+ if (ret < 0)
+ return NF_DROP;
+ if (ret > 0) {
+ ipv6h = ipv6_hdr(skb);
+ oldlen = ipv6h->payload_len;
+ newlen = htons(ntohs(oldlen) + ret);
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ skb->csum = csum_add(csum_sub(skb->csum, (__force __wsum)oldlen),
+ (__force __wsum)newlen);
+ ipv6h->payload_len = newlen;
+ }
+ return XT_CONTINUE;
+}
+#endif
+
+/* Must specify -p tcp --syn */
+static inline bool find_syn_match(const struct xt_entry_match *m)
+{
+ const struct xt_tcp *tcpinfo = (const struct xt_tcp *)m->data;
+
+ if (strcmp(m->u.kernel.match->name, "tcp") == 0 &&
+ tcpinfo->flg_cmp & TCPHDR_SYN &&
+ !(tcpinfo->invflags & XT_TCP_INV_FLAGS))
+ return true;
+
return false;
}
-static struct xt_match tcpmss_mt_reg[] __read_mostly = {
+static int tcpmss_tg4_check(const struct xt_tgchk_param *par)
+{
+ const struct xt_tcpmss_info *info = par->targinfo;
+ const struct ipt_entry *e = par->entryinfo;
+ const struct xt_entry_match *ematch;
+
+ if (info->mss == XT_TCPMSS_CLAMP_PMTU &&
+ (par->hook_mask & ~((1 << NF_INET_FORWARD) |
+ (1 << NF_INET_LOCAL_OUT) |
+ (1 << NF_INET_POST_ROUTING))) != 0) {
+ pr_info_ratelimited("path-MTU clamping only supported in FORWARD, OUTPUT and POSTROUTING hooks\n");
+ return -EINVAL;
+ }
+ if (par->nft_compat)
+ return 0;
+
+ xt_ematch_foreach(ematch, e)
+ if (find_syn_match(ematch))
+ return 0;
+ pr_info_ratelimited("Only works on TCP SYN packets\n");
+ return -EINVAL;
+}
+
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+static int tcpmss_tg6_check(const struct xt_tgchk_param *par)
+{
+ const struct xt_tcpmss_info *info = par->targinfo;
+ const struct ip6t_entry *e = par->entryinfo;
+ const struct xt_entry_match *ematch;
+
+ if (info->mss == XT_TCPMSS_CLAMP_PMTU &&
+ (par->hook_mask & ~((1 << NF_INET_FORWARD) |
+ (1 << NF_INET_LOCAL_OUT) |
+ (1 << NF_INET_POST_ROUTING))) != 0) {
+ pr_info_ratelimited("path-MTU clamping only supported in FORWARD, OUTPUT and POSTROUTING hooks\n");
+ return -EINVAL;
+ }
+ if (par->nft_compat)
+ return 0;
+
+ xt_ematch_foreach(ematch, e)
+ if (find_syn_match(ematch))
+ return 0;
+ pr_info_ratelimited("Only works on TCP SYN packets\n");
+ return -EINVAL;
+}
+#endif
+
+static struct xt_target tcpmss_tg_reg[] __read_mostly = {
{
- .name = "tcpmss",
.family = NFPROTO_IPV4,
- .match = tcpmss_mt,
- .matchsize = sizeof(struct xt_tcpmss_match_info),
+ .name = "TCPMSS",
+ .checkentry = tcpmss_tg4_check,
+ .target = tcpmss_tg4,
+ .targetsize = sizeof(struct xt_tcpmss_info),
.proto = IPPROTO_TCP,
.me = THIS_MODULE,
},
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
{
- .name = "tcpmss",
.family = NFPROTO_IPV6,
- .match = tcpmss_mt,
- .matchsize = sizeof(struct xt_tcpmss_match_info),
+ .name = "TCPMSS",
+ .checkentry = tcpmss_tg6_check,
+ .target = tcpmss_tg6,
+ .targetsize = sizeof(struct xt_tcpmss_info),
.proto = IPPROTO_TCP,
.me = THIS_MODULE,
},
+#endif
};
-static int __init tcpmss_mt_init(void)
+static int __init tcpmss_tg_init(void)
{
- return xt_register_matches(tcpmss_mt_reg, ARRAY_SIZE(tcpmss_mt_reg));
+ return xt_register_targets(tcpmss_tg_reg, ARRAY_SIZE(tcpmss_tg_reg));
}
-static void __exit tcpmss_mt_exit(void)
+static void __exit tcpmss_tg_exit(void)
{
- xt_unregister_matches(tcpmss_mt_reg, ARRAY_SIZE(tcpmss_mt_reg));
+ xt_unregister_targets(tcpmss_tg_reg, ARRAY_SIZE(tcpmss_tg_reg));
}
-module_init(tcpmss_mt_init);
-module_exit(tcpmss_mt_exit);
+module_init(tcpmss_tg_init);
+module_exit(tcpmss_tg_exit);
diff --git a/tools/memory-model/litmus-tests/Z6.0+pooncelock+pooncelock+pombonce.litmus b/tools/memory-model/litmus-tests/Z6.0+pooncelock+pooncelock+pombonce.litmus
index 10a2aa04c..415248fb6 100644
--- a/tools/memory-model/litmus-tests/Z6.0+pooncelock+pooncelock+pombonce.litmus
+++ b/tools/memory-model/litmus-tests/Z6.0+pooncelock+pooncelock+pombonce.litmus
@@ -1,11 +1,12 @@
-C Z6.0+pooncelock+pooncelock+pombonce
+C Z6.0+pooncelock+poonceLock+pombonce
(*
- * Result: Sometimes
+ * Result: Never
*
- * This example demonstrates that a pair of accesses made by different
- * processes each while holding a given lock will not necessarily be
- * seen as ordered by a third process not holding that lock.
+ * This litmus test demonstrates how smp_mb__after_spinlock() may be
+ * used to ensure that accesses in different critical sections for a
+ * given lock running on different CPUs are nevertheless seen in order
+ * by CPUs not holding that lock.
*)
{}
@@ -23,6 +24,7 @@ P1(int *y, int *z, spinlock_t *mylock)
int r0;
spin_lock(mylock);
+ smp_mb__after_spinlock();
r0 = READ_ONCE(*y);
WRITE_ONCE(*z, 1);
spin_unlock(mylock);
--
2.37.3