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Author SHA1 Message Date
cgy f39cf4183f 加了空格试试 2024-12-31 15:11:17 +08:00
cgy f40b6c4f9f only check out no any change 2024-12-31 10:13:36 +08:00
14 changed files with 492 additions and 815 deletions

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@ -1,6 +1,31 @@
#ifndef _XT_CONNMARK_H_target #ifndef _XT_CONNMARK_H
#define _XT_CONNMARK_H_target #define _XT_CONNMARK_H
#include <linux/netfilter/xt_connmark.h> #include <linux/types.h>
#endif /*_XT_CONNMARK_H_target*/ /* Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
* by Henrik Nordstrom <hno@marasystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
enum {
XT_CONNMARK_SET = 0,
XT_CONNMARK_SAVE,
XT_CONNMARK_RESTORE
};
struct xt_connmark_tginfo1 {
__u32 ctmark, ctmask, nfmask;
__u8 mode;
};
struct xt_connmark_mtinfo1 {
__u32 mark, mask;
__u8 invert;
};
#endif /*_XT_CONNMARK_H*/

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@ -1,26 +1,31 @@
/* x_tables module for setting the IPv4/IPv6 DSCP field /* x_tables module for matching the IPv4/IPv6 DSCP field
* *
* (C) 2002 Harald Welte <laforge@gnumonks.org> * (C) 2002 Harald Welte <laforge@gnumonks.org>
* based on ipt_FTOS.c (C) 2000 by Matthew G. Marsh <mgm@paktronix.com>
* This software is distributed under GNU GPL v2, 1991 * This software is distributed under GNU GPL v2, 1991
* *
* See RFC2474 for a description of the DSCP field within the IP Header. * See RFC2474 for a description of the DSCP field within the IP Header.
* *
* xt_DSCP.h,v 1.7 2002/03/14 12:03:13 laforge Exp * xt_dscp.h,v 1.3 2002/08/05 19:00:21 laforge Exp
*/ */
#ifndef _XT_DSCP_TARGET_H #ifndef _XT_DSCP_H
#define _XT_DSCP_TARGET_H #define _XT_DSCP_H
#include <linux/netfilter/xt_dscp.h>
#include <linux/types.h> #include <linux/types.h>
/* target info */ #define XT_DSCP_MASK 0xfc /* 11111100 */
struct xt_DSCP_info { #define XT_DSCP_SHIFT 2
#define XT_DSCP_MAX 0x3f /* 00111111 */
/* match info */
struct xt_dscp_info {
__u8 dscp; __u8 dscp;
__u8 invert;
}; };
struct xt_tos_target_info { struct xt_tos_match_info {
__u8 tos_value;
__u8 tos_mask; __u8 tos_mask;
__u8 tos_value;
__u8 invert;
}; };
#endif /* _XT_DSCP_TARGET_H */ #endif /* _XT_DSCP_H */

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@ -1,6 +1,15 @@
#ifndef _XT_MARK_H_target #ifndef _XT_MARK_H
#define _XT_MARK_H_target #define _XT_MARK_H
#include <linux/netfilter/xt_mark.h> #include <linux/types.h>
#endif /*_XT_MARK_H_target */ struct xt_mark_tginfo2 {
__u32 mark, mask;
};
struct xt_mark_mtinfo1 {
__u32 mark, mask;
__u8 invert;
};
#endif /*_XT_MARK_H*/

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@ -1,15 +1,37 @@
#ifndef _XT_RATEEST_TARGET_H #ifndef _XT_RATEEST_MATCH_H
#define _XT_RATEEST_TARGET_H #define _XT_RATEEST_MATCH_H
#include <linux/types.h> #include <linux/types.h>
struct xt_rateest_target_info { enum xt_rateest_match_flags {
char name[IFNAMSIZ]; XT_RATEEST_MATCH_INVERT = 1<<0,
__s8 interval; XT_RATEEST_MATCH_ABS = 1<<1,
__u8 ewma_log; XT_RATEEST_MATCH_REL = 1<<2,
XT_RATEEST_MATCH_DELTA = 1<<3,
/* Used internally by the kernel */ XT_RATEEST_MATCH_BPS = 1<<4,
struct xt_rateest *est __attribute__((aligned(8))); XT_RATEEST_MATCH_PPS = 1<<5,
}; };
#endif /* _XT_RATEEST_TARGET_H */ 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;
/* Used internally by the kernel */
struct xt_rateest *est1 __attribute__((aligned(8)));
struct xt_rateest *est2 __attribute__((aligned(8)));
};
#endif /* _XT_RATEEST_MATCH_H */

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@ -1,12 +1,11 @@
#ifndef _XT_TCPMSS_H #ifndef _XT_TCPMSS_MATCH_H
#define _XT_TCPMSS_H #define _XT_TCPMSS_MATCH_H
#include <linux/types.h> #include <linux/types.h>
struct xt_tcpmss_info { struct xt_tcpmss_match_info {
__u16 mss; __u16 mss_min, mss_max;
__u8 invert;
}; };
#define XT_TCPMSS_CLAMP_PMTU 0xffff #endif /*_XT_TCPMSS_MATCH_H*/
#endif /* _XT_TCPMSS_H */

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@ -1,33 +1,35 @@
/* Header file for iptables ipt_ECN target /* iptables module for matching the ECN header in IPv4 and TCP header
* *
* (C) 2002 by Harald Welte <laforge@gnumonks.org> * (C) 2002 Harald Welte <laforge@gnumonks.org>
* *
* This software is distributed under GNU GPL v2, 1991 * This software is distributed under GNU GPL v2, 1991
* *
* ipt_ECN.h,v 1.3 2002/05/29 12:17:40 laforge Exp * ipt_ecn.h,v 1.4 2002/08/05 19:39:00 laforge Exp
*/ */
#ifndef _IPT_ECN_TARGET_H #ifndef _IPT_ECN_H
#define _IPT_ECN_TARGET_H #define _IPT_ECN_H
#include <linux/types.h> #include <linux/types.h>
#include <linux/netfilter/xt_DSCP.h> #include <linux/netfilter/xt_dscp.h>
#define IPT_ECN_IP_MASK (~XT_DSCP_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_MATCH_IP 0x01
#define IPT_ECN_OP_SET_ECE 0x10 /* set ECE bit of TCP header */ #define IPT_ECN_OP_MATCH_ECE 0x10
#define IPT_ECN_OP_SET_CWR 0x20 /* set CWR bit of TCP header */ #define IPT_ECN_OP_MATCH_CWR 0x20
#define IPT_ECN_OP_MASK 0xce #define IPT_ECN_OP_MATCH_MASK 0xce
struct ipt_ECN_info { /* match info */
__u8 operation; /* bitset of operations */ struct ipt_ecn_info {
__u8 ip_ect; /* ECT codepoint of IPv4 header, pre-shifted */ __u8 operation;
__u8 invert;
__u8 ip_ect;
union { union {
struct { struct {
__u8 ece:1, cwr:1; /* TCP ECT bits */ __u8 ect;
} tcp; } tcp;
} proto; } proto;
}; };
#endif /* _IPT_ECN_TARGET_H */ #endif /* _IPT_ECN_H */

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@ -1,5 +1,5 @@
/* TTL modification module for IP tables /* IP tables module for matching the value of the TTL
* (C) 2000 by Harald Welte <laforge@netfilter.org> */ * (C) 2000 by Harald Welte <laforge@gnumonks.org> */
#ifndef _IPT_TTL_H #ifndef _IPT_TTL_H
#define _IPT_TTL_H #define _IPT_TTL_H
@ -7,14 +7,14 @@
#include <linux/types.h> #include <linux/types.h>
enum { enum {
IPT_TTL_SET = 0, IPT_TTL_EQ = 0, /* equals */
IPT_TTL_INC, IPT_TTL_NE, /* not equals */
IPT_TTL_DEC IPT_TTL_LT, /* less than */
IPT_TTL_GT, /* greater than */
}; };
#define IPT_TTL_MAXMODE IPT_TTL_DEC
struct ipt_TTL_info { struct ipt_ttl_info {
__u8 mode; __u8 mode;
__u8 ttl; __u8 ttl;
}; };

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@ -1,6 +1,6 @@
/* Hop Limit modification module for ip6tables /* ip6tables module for matching the Hop Limit value
* Maciej Soltysiak <solt@dns.toxicfilms.tv> * Maciej Soltysiak <solt@dns.toxicfilms.tv>
* Based on HW's TTL module */ * Based on HW's ttl module */
#ifndef _IP6T_HL_H #ifndef _IP6T_HL_H
#define _IP6T_HL_H #define _IP6T_HL_H
@ -8,14 +8,14 @@
#include <linux/types.h> #include <linux/types.h>
enum { enum {
IP6T_HL_SET = 0, IP6T_HL_EQ = 0, /* equals */
IP6T_HL_INC, IP6T_HL_NE, /* not equals */
IP6T_HL_DEC IP6T_HL_LT, /* less than */
IP6T_HL_GT, /* greater than */
}; };
#define IP6T_HL_MAXMODE IP6T_HL_DEC
struct ip6t_HL_info { struct ip6t_hl_info {
__u8 mode; __u8 mode;
__u8 hop_limit; __u8 hop_limit;
}; };

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@ -68,9 +68,9 @@
*/ */
int acct_parm[3] = {4, 2, 30}; int acct_parm[3] = {4, 2, 30};
#define RESUME (acct_parm[0]) /* >foo% free space - resume */ #define RESUME (acct_parm[0]) /* >foo% free space - resume */
#define SUSPEND (acct_parm[1]) /* <foo% free space - suspend */ #define SUSPEND (acct_parm[1]) /* <foo% free space - suspend */
#define ACCT_TIMEOUT (acct_parm[2]) /* foo second timeout between checks */ #define ACCT_TIMEOUT (acct_parm[2]) /* foo second timeout between checks */
/* /*
* External references and all of the globals. * External references and all of the globals.

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@ -1,138 +1,127 @@
/* iptables module for the IPv4 and TCP ECN bits, Version 1.5 /* IP tables module for matching the value of the IPv4 and TCP ECN bits
* *
* (C) 2002 by Harald Welte <laforge@netfilter.org> * (C) 2002 by Harald Welte <laforge@gnumonks.org>
* *
* This program is free software; you can redistribute it and/or modify * This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as * it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. * published by the Free Software Foundation.
*/ */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/in.h> #include <linux/in.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h> #include <linux/ip.h>
#include <net/ip.h> #include <net/ip.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/tcp.h> #include <linux/tcp.h>
#include <net/checksum.h>
#include <linux/netfilter/x_tables.h> #include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ip_tables.h> #include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_ECN.h> #include <linux/netfilter_ipv4/ipt_ecn.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag modification"); MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag match for IPv4");
MODULE_LICENSE("GPL");
/* set ECT codepoint from IP header. static inline bool match_ip(const struct sk_buff *skb,
* return false if there was an error. */ const struct ipt_ecn_info *einfo)
static inline bool
set_ect_ip(struct sk_buff *skb, const struct ipt_ECN_info *einfo)
{ {
struct iphdr *iph = ip_hdr(skb); return ((ip_hdr(skb)->tos & IPT_ECN_IP_MASK) == einfo->ip_ect) ^
!!(einfo->invert & IPT_ECN_OP_MATCH_IP);
}
if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) { static inline bool match_tcp(const struct sk_buff *skb,
__u8 oldtos; const struct ipt_ecn_info *einfo,
if (!skb_make_writable(skb, sizeof(struct iphdr))) bool *hotdrop)
{
struct tcphdr _tcph;
const struct tcphdr *th;
/* In practice, TCP match does this, so can't fail. But let's
* be good citizens.
*/
th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
if (th == NULL) {
*hotdrop = false;
return false;
}
if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
if (einfo->invert & IPT_ECN_OP_MATCH_ECE) {
if (th->ece == 1)
return false;
} else {
if (th->ece == 0)
return false;
}
}
if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
if (einfo->invert & IPT_ECN_OP_MATCH_CWR) {
if (th->cwr == 1)
return false;
} else {
if (th->cwr == 0)
return false;
}
}
return true;
}
static bool ecn_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct ipt_ecn_info *info = par->matchinfo;
if (info->operation & IPT_ECN_OP_MATCH_IP)
if (!match_ip(skb, info))
return false;
if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) {
if (!match_tcp(skb, info, &par->hotdrop))
return false; return false;
iph = ip_hdr(skb);
oldtos = iph->tos;
iph->tos &= ~IPT_ECN_IP_MASK;
iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK);
csum_replace2(&iph->check, htons(oldtos), htons(iph->tos));
} }
return true; return true;
} }
/* Return false if there was an error. */ static int ecn_mt_check(const struct xt_mtchk_param *par)
static inline bool
set_ect_tcp(struct sk_buff *skb, const struct ipt_ECN_info *einfo)
{ {
struct tcphdr _tcph, *tcph; const struct ipt_ecn_info *info = par->matchinfo;
__be16 oldval; const struct ipt_ip *ip = par->entryinfo;
/* Not enough header? */ if (info->operation & IPT_ECN_OP_MATCH_MASK)
tcph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph); return -EINVAL;
if (!tcph)
return false;
if ((!(einfo->operation & IPT_ECN_OP_SET_ECE) || if (info->invert & IPT_ECN_OP_MATCH_MASK)
tcph->ece == einfo->proto.tcp.ece) && return -EINVAL;
(!(einfo->operation & IPT_ECN_OP_SET_CWR) ||
tcph->cwr == einfo->proto.tcp.cwr))
return true;
if (!skb_make_writable(skb, ip_hdrlen(skb) + sizeof(*tcph))) if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR) &&
return false; (ip->proto != IPPROTO_TCP || ip->invflags & IPT_INV_PROTO)) {
tcph = (void *)ip_hdr(skb) + ip_hdrlen(skb); pr_info("cannot match TCP bits in rule for non-tcp packets\n");
oldval = ((__be16 *)tcph)[6];
if (einfo->operation & IPT_ECN_OP_SET_ECE)
tcph->ece = einfo->proto.tcp.ece;
if (einfo->operation & IPT_ECN_OP_SET_CWR)
tcph->cwr = einfo->proto.tcp.cwr;
inet_proto_csum_replace2(&tcph->check, skb,
oldval, ((__be16 *)tcph)[6], 0);
return true;
}
static unsigned int
ecn_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct ipt_ECN_info *einfo = par->targinfo;
if (einfo->operation & IPT_ECN_OP_SET_IP)
if (!set_ect_ip(skb, einfo))
return NF_DROP;
if (einfo->operation & (IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR) &&
ip_hdr(skb)->protocol == IPPROTO_TCP)
if (!set_ect_tcp(skb, einfo))
return NF_DROP;
return XT_CONTINUE;
}
static int ecn_tg_check(const struct xt_tgchk_param *par)
{
const struct ipt_ECN_info *einfo = par->targinfo;
const struct ipt_entry *e = par->entryinfo;
if (einfo->operation & IPT_ECN_OP_MASK) {
pr_info("unsupported ECN operation %x\n", einfo->operation);
return -EINVAL;
}
if (einfo->ip_ect & ~IPT_ECN_IP_MASK) {
pr_info("new ECT codepoint %x out of mask\n", einfo->ip_ect);
return -EINVAL;
}
if ((einfo->operation & (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR)) &&
(e->ip.proto != IPPROTO_TCP || (e->ip.invflags & XT_INV_PROTO))) {
pr_info("cannot use TCP operations on a non-tcp rule\n");
return -EINVAL; return -EINVAL;
} }
return 0; return 0;
} }
static struct xt_target ecn_tg_reg __read_mostly = { static struct xt_match ecn_mt_reg __read_mostly = {
.name = "ECN", .name = "ecn",
.family = NFPROTO_IPV4, .family = NFPROTO_IPV4,
.target = ecn_tg, .match = ecn_mt,
.targetsize = sizeof(struct ipt_ECN_info), .matchsize = sizeof(struct ipt_ecn_info),
.table = "mangle", .checkentry = ecn_mt_check,
.checkentry = ecn_tg_check,
.me = THIS_MODULE, .me = THIS_MODULE,
}; };
static int __init ecn_tg_init(void) static int __init ecn_mt_init(void)
{ {
return xt_register_target(&ecn_tg_reg); return xt_register_match(&ecn_mt_reg);
} }
static void __exit ecn_tg_exit(void) static void __exit ecn_mt_exit(void)
{ {
xt_unregister_target(&ecn_tg_reg); xt_unregister_match(&ecn_mt_reg);
} }
module_init(ecn_tg_init); module_init(ecn_mt_init);
module_exit(ecn_tg_exit); module_exit(ecn_mt_exit);

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@ -1,14 +1,11 @@
/* x_tables module for setting the IPv4/IPv6 DSCP field, Version 1.8 /* IP tables module for matching the value of the IPv4/IPv6 DSCP field
* *
* (C) 2002 by Harald Welte <laforge@netfilter.org> * (C) 2002 by Harald Welte <laforge@netfilter.org>
* based on ipt_FTOS.c (C) 2000 by Matthew G. Marsh <mgm@paktronix.com>
* *
* This program is free software; you can redistribute it and/or modify * This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as * it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. * published by the Free Software Foundation.
* */
* See RFC2474 for a description of the DSCP field within the IP Header.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h> #include <linux/module.h>
#include <linux/skbuff.h> #include <linux/skbuff.h>
@ -17,148 +14,102 @@
#include <net/dsfield.h> #include <net/dsfield.h>
#include <linux/netfilter/x_tables.h> #include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_DSCP.h> #include <linux/netfilter/xt_dscp.h>
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("Xtables: DSCP/TOS field modification"); MODULE_DESCRIPTION("Xtables: DSCP/TOS field match");
MODULE_LICENSE("GPL"); MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_DSCP"); MODULE_ALIAS("ipt_dscp");
MODULE_ALIAS("ip6t_DSCP"); MODULE_ALIAS("ip6t_dscp");
MODULE_ALIAS("ipt_TOS"); MODULE_ALIAS("ipt_tos");
MODULE_ALIAS("ip6t_TOS"); MODULE_ALIAS("ip6t_tos");
static unsigned int static bool
dscp_tg(struct sk_buff *skb, const struct xt_action_param *par) dscp_mt(const struct sk_buff *skb, struct xt_action_param *par)
{ {
const struct xt_DSCP_info *dinfo = par->targinfo; const struct xt_dscp_info *info = par->matchinfo;
u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT; u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
if (dscp != dinfo->dscp) { return (dscp == info->dscp) ^ !!info->invert;
if (!skb_make_writable(skb, sizeof(struct iphdr)))
return NF_DROP;
ipv4_change_dsfield(ip_hdr(skb), (__u8)(~XT_DSCP_MASK),
dinfo->dscp << XT_DSCP_SHIFT);
}
return XT_CONTINUE;
} }
static unsigned int static bool
dscp_tg6(struct sk_buff *skb, const struct xt_action_param *par) dscp_mt6(const struct sk_buff *skb, struct xt_action_param *par)
{ {
const struct xt_DSCP_info *dinfo = par->targinfo; const struct xt_dscp_info *info = par->matchinfo;
u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT; u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
if (dscp != dinfo->dscp) { return (dscp == info->dscp) ^ !!info->invert;
if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
return NF_DROP;
ipv6_change_dsfield(ipv6_hdr(skb), (__u8)(~XT_DSCP_MASK),
dinfo->dscp << XT_DSCP_SHIFT);
}
return XT_CONTINUE;
} }
static int dscp_tg_check(const struct xt_tgchk_param *par) static int dscp_mt_check(const struct xt_mtchk_param *par)
{ {
const struct xt_DSCP_info *info = par->targinfo; const struct xt_dscp_info *info = par->matchinfo;
if (info->dscp > XT_DSCP_MAX) { if (info->dscp > XT_DSCP_MAX) {
pr_info("dscp %x out of range\n", info->dscp); pr_info("dscp %x out of range\n", info->dscp);
return -EDOM; return -EDOM;
} }
return 0; return 0;
} }
static unsigned int static bool tos_mt(const struct sk_buff *skb, struct xt_action_param *par)
tos_tg(struct sk_buff *skb, const struct xt_action_param *par)
{ {
const struct xt_tos_target_info *info = par->targinfo; const struct xt_tos_match_info *info = par->matchinfo;
struct iphdr *iph = ip_hdr(skb);
u_int8_t orig, nv;
orig = ipv4_get_dsfield(iph); if (par->family == NFPROTO_IPV4)
nv = (orig & ~info->tos_mask) ^ info->tos_value; return ((ip_hdr(skb)->tos & info->tos_mask) ==
info->tos_value) ^ !!info->invert;
if (orig != nv) { else
if (!skb_make_writable(skb, sizeof(struct iphdr))) return ((ipv6_get_dsfield(ipv6_hdr(skb)) & info->tos_mask) ==
return NF_DROP; info->tos_value) ^ !!info->invert;
iph = ip_hdr(skb);
ipv4_change_dsfield(iph, 0, nv);
}
return XT_CONTINUE;
} }
static unsigned int static struct xt_match dscp_mt_reg[] __read_mostly = {
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_make_writable(skb, sizeof(struct iphdr)))
return NF_DROP;
iph = ipv6_hdr(skb);
ipv6_change_dsfield(iph, 0, nv);
}
return XT_CONTINUE;
}
static struct xt_target dscp_tg_reg[] __read_mostly = {
{ {
.name = "DSCP", .name = "dscp",
.family = NFPROTO_IPV4, .family = NFPROTO_IPV4,
.checkentry = dscp_tg_check, .checkentry = dscp_mt_check,
.target = dscp_tg, .match = dscp_mt,
.targetsize = sizeof(struct xt_DSCP_info), .matchsize = sizeof(struct xt_dscp_info),
.table = "mangle",
.me = THIS_MODULE, .me = THIS_MODULE,
}, },
{ {
.name = "DSCP", .name = "dscp",
.family = NFPROTO_IPV6, .family = NFPROTO_IPV6,
.checkentry = dscp_tg_check, .checkentry = dscp_mt_check,
.target = dscp_tg6, .match = dscp_mt6,
.targetsize = sizeof(struct xt_DSCP_info), .matchsize = sizeof(struct xt_dscp_info),
.table = "mangle",
.me = THIS_MODULE, .me = THIS_MODULE,
}, },
{ {
.name = "TOS", .name = "tos",
.revision = 1, .revision = 1,
.family = NFPROTO_IPV4, .family = NFPROTO_IPV4,
.table = "mangle", .match = tos_mt,
.target = tos_tg, .matchsize = sizeof(struct xt_tos_match_info),
.targetsize = sizeof(struct xt_tos_target_info),
.me = THIS_MODULE, .me = THIS_MODULE,
}, },
{ {
.name = "TOS", .name = "tos",
.revision = 1, .revision = 1,
.family = NFPROTO_IPV6, .family = NFPROTO_IPV6,
.table = "mangle", .match = tos_mt,
.target = tos_tg6, .matchsize = sizeof(struct xt_tos_match_info),
.targetsize = sizeof(struct xt_tos_target_info),
.me = THIS_MODULE, .me = THIS_MODULE,
}, },
}; };
static int __init dscp_tg_init(void) static int __init dscp_mt_init(void)
{ {
return xt_register_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg)); return xt_register_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
} }
static void __exit dscp_tg_exit(void) static void __exit dscp_mt_exit(void)
{ {
xt_unregister_targets(dscp_tg_reg, ARRAY_SIZE(dscp_tg_reg)); xt_unregister_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
} }
module_init(dscp_tg_init); module_init(dscp_mt_init);
module_exit(dscp_tg_exit); module_exit(dscp_mt_exit);

View File

@ -1,169 +1,96 @@
/* /*
* TTL modification target for IP tables * IP tables module for matching the value of the TTL
* (C) 2000,2005 by Harald Welte <laforge@netfilter.org> * (C) 2000,2001 by Harald Welte <laforge@netfilter.org>
* *
* Hop Limit modification target for ip6tables * Hop Limit matching module
* Maciej Soltysiak <solt@dns.toxicfilms.tv> * (C) 2001-2002 Maciej Soltysiak <solt@dns.toxicfilms.tv>
* *
* This program is free software; you can redistribute it and/or modify * This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as * it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. * published by the Free Software Foundation.
*/ */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h> #include <linux/ip.h>
#include <linux/ipv6.h> #include <linux/ipv6.h>
#include <net/checksum.h> #include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter/x_tables.h> #include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ipt_TTL.h> #include <linux/netfilter_ipv4/ipt_ttl.h>
#include <linux/netfilter_ipv6/ip6t_HL.h> #include <linux/netfilter_ipv6/ip6t_hl.h>
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_AUTHOR("Maciej Soltysiak <solt@dns.toxicfilms.tv>"); MODULE_AUTHOR("Maciej Soltysiak <solt@dns.toxicfilms.tv>");
MODULE_DESCRIPTION("Xtables: Hoplimit/TTL Limit field modification target"); MODULE_DESCRIPTION("Xtables: Hoplimit/TTL field match");
MODULE_LICENSE("GPL"); MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_ttl");
MODULE_ALIAS("ip6t_hl");
static unsigned int static bool ttl_mt(const struct sk_buff *skb, struct xt_action_param *par)
ttl_tg(struct sk_buff *skb, const struct xt_action_param *par)
{ {
struct iphdr *iph; const struct ipt_ttl_info *info = par->matchinfo;
const struct ipt_TTL_info *info = par->targinfo; const u8 ttl = ip_hdr(skb)->ttl;
int new_ttl;
if (!skb_make_writable(skb, skb->len))
return NF_DROP;
iph = ip_hdr(skb);
switch (info->mode) { switch (info->mode) {
case IPT_TTL_SET: case IPT_TTL_EQ:
new_ttl = info->ttl; return ttl == info->ttl;
break; case IPT_TTL_NE:
case IPT_TTL_INC: return ttl != info->ttl;
new_ttl = iph->ttl + info->ttl; case IPT_TTL_LT:
if (new_ttl > 255) return ttl < info->ttl;
new_ttl = 255; case IPT_TTL_GT:
break; return ttl > info->ttl;
case IPT_TTL_DEC:
new_ttl = iph->ttl - info->ttl;
if (new_ttl < 0)
new_ttl = 0;
break;
default:
new_ttl = iph->ttl;
break;
} }
if (new_ttl != iph->ttl) { return false;
csum_replace2(&iph->check, htons(iph->ttl << 8),
htons(new_ttl << 8));
iph->ttl = new_ttl;
}
return XT_CONTINUE;
} }
static unsigned int static bool hl_mt6(const struct sk_buff *skb, struct xt_action_param *par)
hl_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{ {
struct ipv6hdr *ip6h; const struct ip6t_hl_info *info = par->matchinfo;
const struct ip6t_HL_info *info = par->targinfo; const struct ipv6hdr *ip6h = ipv6_hdr(skb);
int new_hl;
if (!skb_make_writable(skb, skb->len))
return NF_DROP;
ip6h = ipv6_hdr(skb);
switch (info->mode) { switch (info->mode) {
case IP6T_HL_SET: case IP6T_HL_EQ:
new_hl = info->hop_limit; return ip6h->hop_limit == info->hop_limit;
break; case IP6T_HL_NE:
case IP6T_HL_INC: return ip6h->hop_limit != info->hop_limit;
new_hl = ip6h->hop_limit + info->hop_limit; case IP6T_HL_LT:
if (new_hl > 255) return ip6h->hop_limit < info->hop_limit;
new_hl = 255; case IP6T_HL_GT:
break; return ip6h->hop_limit > info->hop_limit;
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;
} }
ip6h->hop_limit = new_hl; return false;
return XT_CONTINUE;
} }
static int ttl_tg_check(const struct xt_tgchk_param *par) static struct xt_match hl_mt_reg[] __read_mostly = {
{
const struct ipt_TTL_info *info = par->targinfo;
if (info->mode > IPT_TTL_MAXMODE) {
pr_info("TTL: invalid or unknown mode %u\n", info->mode);
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) {
pr_info("invalid or unknown mode %u\n", info->mode);
return -EINVAL;
}
if (info->mode != IP6T_HL_SET && info->hop_limit == 0) {
pr_info("increment/decrement does not "
"make sense with value 0\n");
return -EINVAL;
}
return 0;
}
static struct xt_target hl_tg_reg[] __read_mostly = {
{ {
.name = "TTL", .name = "ttl",
.revision = 0, .revision = 0,
.family = NFPROTO_IPV4, .family = NFPROTO_IPV4,
.target = ttl_tg, .match = ttl_mt,
.targetsize = sizeof(struct ipt_TTL_info), .matchsize = sizeof(struct ipt_ttl_info),
.table = "mangle",
.checkentry = ttl_tg_check,
.me = THIS_MODULE, .me = THIS_MODULE,
}, },
{ {
.name = "HL", .name = "hl",
.revision = 0, .revision = 0,
.family = NFPROTO_IPV6, .family = NFPROTO_IPV6,
.target = hl_tg6, .match = hl_mt6,
.targetsize = sizeof(struct ip6t_HL_info), .matchsize = sizeof(struct ip6t_hl_info),
.table = "mangle",
.checkentry = hl_tg6_check,
.me = THIS_MODULE, .me = THIS_MODULE,
}, },
}; };
static int __init hl_tg_init(void) static int __init hl_mt_init(void)
{ {
return xt_register_targets(hl_tg_reg, ARRAY_SIZE(hl_tg_reg)); return xt_register_matches(hl_mt_reg, ARRAY_SIZE(hl_mt_reg));
} }
static void __exit hl_tg_exit(void) static void __exit hl_mt_exit(void)
{ {
xt_unregister_targets(hl_tg_reg, ARRAY_SIZE(hl_tg_reg)); xt_unregister_matches(hl_mt_reg, ARRAY_SIZE(hl_mt_reg));
} }
module_init(hl_tg_init); module_init(hl_mt_init);
module_exit(hl_tg_exit); module_exit(hl_mt_exit);
MODULE_ALIAS("ipt_TTL");
MODULE_ALIAS("ip6t_HL");

View File

@ -8,194 +8,151 @@
#include <linux/module.h> #include <linux/module.h>
#include <linux/skbuff.h> #include <linux/skbuff.h>
#include <linux/gen_stats.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 <linux/netfilter/x_tables.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> #include <net/netfilter/xt_rateest.h>
static DEFINE_MUTEX(xt_rateest_mutex);
#define RATEEST_HSIZE 16 static bool
static struct hlist_head rateest_hash[RATEEST_HSIZE] __read_mostly; xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par)
static unsigned int jhash_rnd __read_mostly;
static bool rnd_inited __read_mostly;
static unsigned int xt_rateest_hash(const char *name)
{ {
return jhash(name, FIELD_SIZEOF(struct xt_rateest, name), jhash_rnd) & const struct xt_rateest_match_info *info = par->matchinfo;
(RATEEST_HSIZE - 1); struct gnet_stats_rate_est *r;
} u_int32_t bps1, bps2, pps1, pps2;
bool ret = true;
static void xt_rateest_hash_insert(struct xt_rateest *est) spin_lock_bh(&info->est1->lock);
{ r = &info->est1->rstats;
unsigned int h; if (info->flags & XT_RATEEST_MATCH_DELTA) {
bps1 = info->bps1 >= r->bps ? info->bps1 - r->bps : 0;
pps1 = info->pps1 >= r->pps ? info->pps1 - r->pps : 0;
} else {
bps1 = r->bps;
pps1 = r->pps;
}
spin_unlock_bh(&info->est1->lock);
h = xt_rateest_hash(est->name); if (info->flags & XT_RATEEST_MATCH_ABS) {
hlist_add_head(&est->list, &rateest_hash[h]); bps2 = info->bps2;
} pps2 = info->pps2;
} else {
struct xt_rateest *xt_rateest_lookup(const char *name) spin_lock_bh(&info->est2->lock);
{ r = &info->est2->rstats;
struct xt_rateest *est; if (info->flags & XT_RATEEST_MATCH_DELTA) {
struct hlist_node *n; bps2 = info->bps2 >= r->bps ? info->bps2 - r->bps : 0;
unsigned int h; pps2 = info->pps2 >= r->pps ? info->pps2 - r->pps : 0;
} else {
h = xt_rateest_hash(name); bps2 = r->bps;
mutex_lock(&xt_rateest_mutex); pps2 = r->pps;
hlist_for_each_entry(est, n, &rateest_hash[h], list) {
if (strcmp(est->name, name) == 0) {
est->refcnt++;
mutex_unlock(&xt_rateest_mutex);
return est;
} }
} spin_unlock_bh(&info->est2->lock);
mutex_unlock(&xt_rateest_mutex);
return NULL;
}
EXPORT_SYMBOL_GPL(xt_rateest_lookup);
static void xt_rateest_free_rcu(struct rcu_head *head)
{
kfree(container_of(head, struct xt_rateest, rcu));
}
void xt_rateest_put(struct xt_rateest *est)
{
mutex_lock(&xt_rateest_mutex);
if (--est->refcnt == 0) {
hlist_del(&est->list);
gen_kill_estimator(&est->bstats, &est->rstats);
/*
* gen_estimator est_timer() might access est->lock or bstats,
* wait a RCU grace period before freeing 'est'
*/
call_rcu(&est->rcu, xt_rateest_free_rcu);
}
mutex_unlock(&xt_rateest_mutex);
}
EXPORT_SYMBOL_GPL(xt_rateest_put);
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_packed *stats = &info->est->bstats;
spin_lock_bh(&info->est->lock);
stats->bytes += skb->len;
stats->packets++;
spin_unlock_bh(&info->est->lock);
return XT_CONTINUE;
}
static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
{
struct xt_rateest_target_info *info = par->targinfo;
struct xt_rateest *est;
struct {
struct nlattr opt;
struct gnet_estimator est;
} cfg;
int ret;
if (unlikely(!rnd_inited)) {
get_random_bytes(&jhash_rnd, sizeof(jhash_rnd));
rnd_inited = true;
} }
est = xt_rateest_lookup(info->name); switch (info->mode) {
if (est) { case XT_RATEEST_MATCH_LT:
/* if (info->flags & XT_RATEEST_MATCH_BPS)
* If estimator parameters are specified, they must match the ret &= bps1 < bps2;
* existing estimator. if (info->flags & XT_RATEEST_MATCH_PPS)
*/ ret &= pps1 < pps2;
if ((!info->interval && !info->ewma_log) || break;
(info->interval != est->params.interval || case XT_RATEEST_MATCH_GT:
info->ewma_log != est->params.ewma_log)) { if (info->flags & XT_RATEEST_MATCH_BPS)
xt_rateest_put(est); ret &= bps1 > bps2;
return -EINVAL; if (info->flags & XT_RATEEST_MATCH_PPS)
} ret &= pps1 > pps2;
info->est = est; break;
return 0; 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;
} }
ret = -ENOMEM; ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
est = kzalloc(sizeof(*est), GFP_KERNEL);
if (!est)
goto err1;
strlcpy(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, &est->rstats,
&est->lock, &cfg.opt);
if (ret < 0)
goto err2;
info->est = est;
xt_rateest_hash_insert(est);
return 0;
err2:
kfree(est);
err1:
return ret; return ret;
} }
static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par) static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
{ {
struct xt_rateest_target_info *info = par->targinfo; struct xt_rateest_match_info *info = par->matchinfo;
struct xt_rateest *est1, *est2;
int ret = false;
xt_rateest_put(info->est); if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
XT_RATEEST_MATCH_REL)) != 1)
goto err1;
if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
goto err1;
switch (info->mode) {
case XT_RATEEST_MATCH_EQ:
case XT_RATEEST_MATCH_LT:
case XT_RATEEST_MATCH_GT:
break;
default:
goto err1;
}
ret = -ENOENT;
est1 = xt_rateest_lookup(info->name1);
if (!est1)
goto err1;
if (info->flags & XT_RATEEST_MATCH_REL) {
est2 = xt_rateest_lookup(info->name2);
if (!est2)
goto err2;
} else
est2 = NULL;
info->est1 = est1;
info->est2 = est2;
return 0;
err2:
xt_rateest_put(est1);
err1:
return -EINVAL;
} }
static struct xt_target xt_rateest_tg_reg __read_mostly = { static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)
.name = "RATEEST", {
struct xt_rateest_match_info *info = par->matchinfo;
xt_rateest_put(info->est1);
if (info->est2)
xt_rateest_put(info->est2);
}
static struct xt_match xt_rateest_mt_reg __read_mostly = {
.name = "rateest",
.revision = 0, .revision = 0,
.family = NFPROTO_UNSPEC, .family = NFPROTO_UNSPEC,
.target = xt_rateest_tg, .match = xt_rateest_mt,
.checkentry = xt_rateest_tg_checkentry, .checkentry = xt_rateest_mt_checkentry,
.destroy = xt_rateest_tg_destroy, .destroy = xt_rateest_mt_destroy,
.targetsize = sizeof(struct xt_rateest_target_info), .matchsize = sizeof(struct xt_rateest_match_info),
.me = THIS_MODULE, .me = THIS_MODULE,
}; };
static int __init xt_rateest_tg_init(void) static int __init xt_rateest_mt_init(void)
{ {
unsigned int i; return xt_register_match(&xt_rateest_mt_reg);
for (i = 0; i < ARRAY_SIZE(rateest_hash); i++)
INIT_HLIST_HEAD(&rateest_hash[i]);
return xt_register_target(&xt_rateest_tg_reg);
} }
static void __exit xt_rateest_tg_fini(void) static void __exit xt_rateest_mt_fini(void)
{ {
xt_unregister_target(&xt_rateest_tg_reg); xt_unregister_match(&xt_rateest_mt_reg);
rcu_barrier(); /* Wait for completion of call_rcu()'s (xt_rateest_free_rcu) */
} }
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_LICENSE("GPL"); MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Xtables: packet rate estimator"); MODULE_DESCRIPTION("xtables rate estimator match");
MODULE_ALIAS("ipt_RATEEST"); MODULE_ALIAS("ipt_rateest");
MODULE_ALIAS("ip6t_RATEEST"); MODULE_ALIAS("ip6t_rateest");
module_init(xt_rateest_tg_init); module_init(xt_rateest_mt_init);
module_exit(xt_rateest_tg_fini); module_exit(xt_rateest_mt_fini);

View File

@ -1,319 +1,110 @@
/* /* Kernel module to match TCP MSS values. */
* This is a module which is used for setting the MSS option in TCP packets.
* /* Copyright (C) 2000 Marc Boucher <marc@mbsi.ca>
* Copyright (C) 2000 Marc Boucher <marc@mbsi.ca> * Portions (C) 2005 by Harald Welte <laforge@netfilter.org>
* *
* This program is free software; you can redistribute it and/or modify * This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as * it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. * published by the Free Software Foundation.
*/ */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h> #include <linux/module.h>
#include <linux/skbuff.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 <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_ipv4/ip_tables.h>
#include <linux/netfilter_ipv6/ip6_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_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_DESCRIPTION("Xtables: TCP Maximum Segment Size (MSS) adjustment"); MODULE_DESCRIPTION("Xtables: TCP MSS match");
MODULE_ALIAS("ipt_TCPMSS"); MODULE_ALIAS("ipt_tcpmss");
MODULE_ALIAS("ip6t_TCPMSS"); MODULE_ALIAS("ip6t_tcpmss");
static inline unsigned int static bool
optlen(const u_int8_t *opt, unsigned int offset) tcpmss_mt(const struct sk_buff *skb, struct xt_action_param *par)
{ {
/* Beware zero-length options: make finite progress */ const struct xt_tcpmss_match_info *info = par->matchinfo;
if (opt[offset] <= TCPOPT_NOP || opt[offset+1] == 0) const struct tcphdr *th;
return 1; struct tcphdr _tcph;
else /* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
return opt[offset+1]; const u_int8_t *op;
} u8 _opt[15 * 4 - sizeof(_tcph)];
unsigned int i, optlen;
static int /* If we don't have the whole header, drop packet. */
tcpmss_mangle_packet(struct sk_buff *skb, th = skb_header_pointer(skb, par->thoff, sizeof(_tcph), &_tcph);
const struct xt_tcpmss_info *info, if (th == NULL)
unsigned int in_mtu, goto dropit;
unsigned int tcphoff,
unsigned int minlen)
{
struct tcphdr *tcph;
unsigned int tcplen, i;
__be16 oldval;
u16 newmss;
u8 *opt;
if (!skb_make_writable(skb, skb->len)) /* Malformed. */
return -1; if (th->doff*4 < sizeof(*th))
goto dropit;
tcplen = skb->len - tcphoff; optlen = th->doff*4 - sizeof(*th);
tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff); if (!optlen)
goto out;
/* Header cannot be larger than the packet */ /* Truncated options. */
if (tcplen < tcph->doff*4) op = skb_header_pointer(skb, par->thoff + sizeof(*th), optlen, _opt);
return -1; if (op == NULL)
goto dropit;
if (info->mss == XT_TCPMSS_CLAMP_PMTU) { for (i = 0; i < optlen; ) {
if (dst_mtu(skb_dst(skb)) <= minlen) { if (op[i] == TCPOPT_MSS
if (net_ratelimit()) && (optlen - i) >= TCPOLEN_MSS
pr_err("unknown or invalid path-MTU (%u)\n", && op[i+1] == TCPOLEN_MSS) {
dst_mtu(skb_dst(skb))); u_int16_t mssval;
return -1;
} mssval = (op[i+2] << 8) | op[i+3];
if (in_mtu <= minlen) {
if (net_ratelimit()) return (mssval >= info->mss_min &&
pr_err("unknown or invalid path-MTU (%u)\n", mssval <= info->mss_max) ^ info->invert;
in_mtu);
return -1;
}
newmss = min(dst_mtu(skb_dst(skb)), in_mtu) - minlen;
} else
newmss = info->mss;
opt = (u_int8_t *)tcph;
for (i = sizeof(struct tcphdr); i < tcph->doff*4; i += optlen(opt, i)) {
if (opt[i] == TCPOPT_MSS && tcph->doff*4 - i >= TCPOLEN_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),
0);
return 0;
} }
if (op[i] < 2)
i++;
else
i += op[i+1] ? : 1;
} }
out:
return info->invert;
/* There is data after the header so the option can't be added dropit:
without moving it, and doing so may make the SYN packet par->hotdrop = true;
itself too large. Accept the packet unmodified instead. */
if (tcplen > tcph->doff*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);
opt = (u_int8_t *)tcph + sizeof(struct tcphdr);
memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr));
inet_proto_csum_replace2(&tcph->check, skb,
htons(tcplen), htons(tcplen + TCPOLEN_MSS), 1);
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), 0);
oldval = ((__be16 *)tcph)[6];
tcph->doff += TCPOLEN_MSS/4;
inet_proto_csum_replace2(&tcph->check, skb,
oldval, ((__be16 *)tcph)[6], 0);
return TCPOLEN_MSS;
}
static u_int32_t tcpmss_reverse_mtu(const struct sk_buff *skb,
unsigned int family)
{
struct flowi fl;
const struct nf_afinfo *ai;
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));
ipv6_addr_copy(&fl6->daddr, &ipv6_hdr(skb)->saddr);
}
rcu_read_lock();
ai = nf_get_afinfo(family);
if (ai != NULL)
ai->route(&init_net, (struct dst_entry **)&rt, &fl, false);
rcu_read_unlock();
if (rt != NULL) {
mtu = dst_mtu(&rt->dst);
dst_release(&rt->dst);
}
return mtu;
}
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->targinfo,
tcpmss_reverse_mtu(skb, 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 defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
static unsigned int
tcpmss_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
u8 nexthdr;
int tcphoff;
int ret;
nexthdr = ipv6h->nexthdr;
tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr);
if (tcphoff < 0)
return NF_DROP;
ret = tcpmss_mangle_packet(skb, par->targinfo,
tcpmss_reverse_mtu(skb, PF_INET6),
tcphoff,
sizeof(*ipv6h) + sizeof(struct tcphdr));
if (ret < 0)
return NF_DROP;
if (ret > 0) {
ipv6h = ipv6_hdr(skb);
ipv6h->payload_len = htons(ntohs(ipv6h->payload_len) + ret);
}
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; return false;
} }
static int tcpmss_tg4_check(const struct xt_tgchk_param *par) static struct xt_match tcpmss_mt_reg[] __read_mostly = {
{
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("path-MTU clamping only supported in "
"FORWARD, OUTPUT and POSTROUTING hooks\n");
return -EINVAL;
}
xt_ematch_foreach(ematch, e)
if (find_syn_match(ematch))
return 0;
pr_info("Only works on TCP SYN packets\n");
return -EINVAL;
}
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
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("path-MTU clamping only supported in "
"FORWARD, OUTPUT and POSTROUTING hooks\n");
return -EINVAL;
}
xt_ematch_foreach(ematch, e)
if (find_syn_match(ematch))
return 0;
pr_info("Only works on TCP SYN packets\n");
return -EINVAL;
}
#endif
static struct xt_target tcpmss_tg_reg[] __read_mostly = {
{ {
.name = "tcpmss",
.family = NFPROTO_IPV4, .family = NFPROTO_IPV4,
.name = "TCPMSS", .match = tcpmss_mt,
.checkentry = tcpmss_tg4_check, .matchsize = sizeof(struct xt_tcpmss_match_info),
.target = tcpmss_tg4,
.targetsize = sizeof(struct xt_tcpmss_info),
.proto = IPPROTO_TCP, .proto = IPPROTO_TCP,
.me = THIS_MODULE, .me = THIS_MODULE,
}, },
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
{ {
.name = "tcpmss",
.family = NFPROTO_IPV6, .family = NFPROTO_IPV6,
.name = "TCPMSS", .match = tcpmss_mt,
.checkentry = tcpmss_tg6_check, .matchsize = sizeof(struct xt_tcpmss_match_info),
.target = tcpmss_tg6,
.targetsize = sizeof(struct xt_tcpmss_info),
.proto = IPPROTO_TCP, .proto = IPPROTO_TCP,
.me = THIS_MODULE, .me = THIS_MODULE,
}, },
#endif
}; };
static int __init tcpmss_tg_init(void) static int __init tcpmss_mt_init(void)
{ {
return xt_register_targets(tcpmss_tg_reg, ARRAY_SIZE(tcpmss_tg_reg)); return xt_register_matches(tcpmss_mt_reg, ARRAY_SIZE(tcpmss_mt_reg));
} }
static void __exit tcpmss_tg_exit(void) static void __exit tcpmss_mt_exit(void)
{ {
xt_unregister_targets(tcpmss_tg_reg, ARRAY_SIZE(tcpmss_tg_reg)); xt_unregister_matches(tcpmss_mt_reg, ARRAY_SIZE(tcpmss_mt_reg));
} }
module_init(tcpmss_tg_init); module_init(tcpmss_mt_init);
module_exit(tcpmss_tg_exit); module_exit(tcpmss_mt_exit);