From 563d36eb3fb22dd04da9aa6f12e1b9ba0ac115f3 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Wed, 18 Feb 2009 18:38:40 +0100 Subject: [PATCH] netfilter: Combine ipt_TTL and ip6t_HL source Suggested by: James King Similarly to commit c9fd49680954714473d6cbd2546d6ff120f96840, merge TTL and HL. Since HL does not depend on any IPv6-specific function, no new module dependencies would arise. With slight adjustments to the Kconfig help text. Signed-off-by: Jan Engelhardt Signed-off-by: Patrick McHardy --- net/ipv4/netfilter/Kconfig | 15 --- net/ipv4/netfilter/Makefile | 1 - net/ipv4/netfilter/ipt_TTL.c | 97 -------------------- net/ipv6/netfilter/Kconfig | 17 ---- net/ipv6/netfilter/Makefile | 1 - net/ipv6/netfilter/ip6t_HL.c | 95 ------------------- net/netfilter/Kconfig | 15 +++ net/netfilter/Makefile | 1 + net/netfilter/xt_HL.c | 171 +++++++++++++++++++++++++++++++++++ 9 files changed, 187 insertions(+), 226 deletions(-) delete mode 100644 net/ipv4/netfilter/ipt_TTL.c delete mode 100644 net/ipv6/netfilter/ip6t_HL.c create mode 100644 net/netfilter/xt_HL.c diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index 3816e1dc929..3ad9f43b4c4 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -322,21 +322,6 @@ config IP_NF_TARGET_ECN To compile it as a module, choose M here. If unsure, say N. -config IP_NF_TARGET_TTL - tristate 'TTL target support' - depends on IP_NF_MANGLE - depends on NETFILTER_ADVANCED - help - This option adds a `TTL' target, which enables the user to modify - the TTL value of the IP header. - - While it is safe to decrement/lower the TTL, this target also enables - functionality to increment and set the TTL value of the IP header to - arbitrary values. This is EXTREMELY DANGEROUS since you can easily - create immortal packets that loop forever on the network. - - To compile it as a module, choose M here. If unsure, say N. - # raw + specific targets config IP_NF_RAW tristate 'raw table support (required for NOTRACK/TRACE)' diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index 5f9b650d90f..20b0c37155f 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -61,7 +61,6 @@ obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o -obj-$(CONFIG_IP_NF_TARGET_TTL) += ipt_TTL.o obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o # generic ARP tables diff --git a/net/ipv4/netfilter/ipt_TTL.c b/net/ipv4/netfilter/ipt_TTL.c deleted file mode 100644 index 6d76aae90cc..00000000000 --- a/net/ipv4/netfilter/ipt_TTL.c +++ /dev/null @@ -1,97 +0,0 @@ -/* TTL modification target for IP tables - * (C) 2000,2005 by Harald Welte - * - * 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 - * published by the Free Software Foundation. - * - */ - -#include -#include -#include -#include - -#include -#include - -MODULE_AUTHOR("Harald Welte "); -MODULE_DESCRIPTION("Xtables: IPv4 TTL field modification target"); -MODULE_LICENSE("GPL"); - -static unsigned int -ttl_tg(struct sk_buff *skb, const struct xt_target_param *par) -{ - struct iphdr *iph; - const struct ipt_TTL_info *info = par->targinfo; - int new_ttl; - - if (!skb_make_writable(skb, skb->len)) - return NF_DROP; - - iph = ip_hdr(skb); - - switch (info->mode) { - 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; - } - - 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 ttl_tg_check(const struct xt_tgchk_param *par) -{ - const struct ipt_TTL_info *info = par->targinfo; - - if (info->mode > IPT_TTL_MAXMODE) { - printk(KERN_WARNING "ipt_TTL: invalid or unknown Mode %u\n", - info->mode); - return false; - } - if (info->mode != IPT_TTL_SET && info->ttl == 0) - return false; - return true; -} - -static struct xt_target ttl_tg_reg __read_mostly = { - .name = "TTL", - .family = NFPROTO_IPV4, - .target = ttl_tg, - .targetsize = sizeof(struct ipt_TTL_info), - .table = "mangle", - .checkentry = ttl_tg_check, - .me = THIS_MODULE, -}; - -static int __init ttl_tg_init(void) -{ - return xt_register_target(&ttl_tg_reg); -} - -static void __exit ttl_tg_exit(void) -{ - xt_unregister_target(&ttl_tg_reg); -} - -module_init(ttl_tg_init); -module_exit(ttl_tg_exit); diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig index 53ea512c460..6a42a968c49 100644 --- a/net/ipv6/netfilter/Kconfig +++ b/net/ipv6/netfilter/Kconfig @@ -170,23 +170,6 @@ config IP6_NF_MANGLE To compile it as a module, choose M here. If unsure, say N. -config IP6_NF_TARGET_HL - tristate 'HL (hoplimit) target support' - depends on IP6_NF_MANGLE - depends on NETFILTER_ADVANCED - help - This option adds a `HL' target, which enables the user to decrement - the hoplimit value of the IPv6 header or set it to a given (lower) - value. - - While it is safe to decrement the hoplimit value, this option also - enables functionality to increment and set the hoplimit value of the - IPv6 header to arbitrary values. This is EXTREMELY DANGEROUS since - you can easily create immortal packets that loop forever on the - network. - - To compile it as a module, choose M here. If unsure, say N. - config IP6_NF_RAW tristate 'raw table support (required for TRACE)' depends on NETFILTER_ADVANCED diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile index 3f17c948eef..61a4570d0ed 100644 --- a/net/ipv6/netfilter/Makefile +++ b/net/ipv6/netfilter/Makefile @@ -27,6 +27,5 @@ obj-$(CONFIG_IP6_NF_MATCH_OPTS) += ip6t_hbh.o obj-$(CONFIG_IP6_NF_MATCH_RT) += ip6t_rt.o # targets -obj-$(CONFIG_IP6_NF_TARGET_HL) += ip6t_HL.o obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_LOG.o obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o diff --git a/net/ipv6/netfilter/ip6t_HL.c b/net/ipv6/netfilter/ip6t_HL.c deleted file mode 100644 index 27b5adf670a..00000000000 --- a/net/ipv6/netfilter/ip6t_HL.c +++ /dev/null @@ -1,95 +0,0 @@ -/* - * Hop Limit modification target for ip6tables - * Maciej Soltysiak - * Based on HW's TTL module - * - * This software is distributed under the terms of GNU GPL - */ - -#include -#include -#include -#include - -#include -#include - -MODULE_AUTHOR("Maciej Soltysiak "); -MODULE_DESCRIPTION("Xtables: IPv6 Hop Limit field modification target"); -MODULE_LICENSE("GPL"); - -static unsigned int -hl_tg6(struct sk_buff *skb, const struct xt_target_param *par) -{ - struct ipv6hdr *ip6h; - const struct ip6t_HL_info *info = par->targinfo; - int new_hl; - - if (!skb_make_writable(skb, skb->len)) - return NF_DROP; - - ip6h = ipv6_hdr(skb); - - switch (info->mode) { - 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; - } - - ip6h->hop_limit = new_hl; - - return XT_CONTINUE; -} - -static bool hl_tg6_check(const struct xt_tgchk_param *par) -{ - const struct ip6t_HL_info *info = par->targinfo; - - if (info->mode > IP6T_HL_MAXMODE) { - printk(KERN_WARNING "ip6t_HL: invalid or unknown Mode %u\n", - info->mode); - return false; - } - if (info->mode != IP6T_HL_SET && info->hop_limit == 0) { - printk(KERN_WARNING "ip6t_HL: increment/decrement doesn't " - "make sense with value 0\n"); - return false; - } - return true; -} - -static struct xt_target hl_tg6_reg __read_mostly = { - .name = "HL", - .family = NFPROTO_IPV6, - .target = hl_tg6, - .targetsize = sizeof(struct ip6t_HL_info), - .table = "mangle", - .checkentry = hl_tg6_check, - .me = THIS_MODULE -}; - -static int __init hl_tg6_init(void) -{ - return xt_register_target(&hl_tg6_reg); -} - -static void __exit hl_tg6_exit(void) -{ - xt_unregister_target(&hl_tg6_reg); -} - -module_init(hl_tg6_init); -module_exit(hl_tg6_exit); diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index c2bac9cd0ca..d99f29b7b98 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -357,6 +357,21 @@ config NETFILTER_XT_TARGET_DSCP To compile it as a module, choose M here. If unsure, say N. +config NETFILTER_XT_TARGET_HL + tristate '"HL" hoplimit target support' + depends on IP_NF_MANGLE || IP6_NF_MANGLE + depends on NETFILTER_ADVANCED + ---help--- + This option adds the "HL" (for IPv6) and "TTL" (for IPv4) + targets, which enable the user to change the + hoplimit/time-to-live value of the IP header. + + While it is safe to decrement the hoplimit/TTL value, the + modules also allow to increment and set the hoplimit value of + the header to arbitrary values. This is EXTREMELY DANGEROUS + since you can easily create immortal packets that loop + forever on the network. + config NETFILTER_XT_TARGET_MARK tristate '"MARK" target support' default m if NETFILTER_ADVANCED=n diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index da3d909e053..6ebe0482265 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -45,6 +45,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_CLASSIFY) += xt_CLASSIFY.o obj-$(CONFIG_NETFILTER_XT_TARGET_CONNMARK) += xt_CONNMARK.o obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o obj-$(CONFIG_NETFILTER_XT_TARGET_DSCP) += xt_DSCP.o +obj-$(CONFIG_NETFILTER_XT_TARGET_HL) += xt_HL.o obj-$(CONFIG_NETFILTER_XT_TARGET_MARK) += xt_MARK.o obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o diff --git a/net/netfilter/xt_HL.c b/net/netfilter/xt_HL.c new file mode 100644 index 00000000000..10e789e2d12 --- /dev/null +++ b/net/netfilter/xt_HL.c @@ -0,0 +1,171 @@ +/* + * TTL modification target for IP tables + * (C) 2000,2005 by Harald Welte + * + * Hop Limit modification target for ip6tables + * Maciej Soltysiak + * + * 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 + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include + +#include +#include +#include + +MODULE_AUTHOR("Harald Welte "); +MODULE_AUTHOR("Maciej Soltysiak "); +MODULE_DESCRIPTION("Xtables: Hoplimit/TTL Limit field modification target"); +MODULE_LICENSE("GPL"); + +static unsigned int +ttl_tg(struct sk_buff *skb, const struct xt_target_param *par) +{ + struct iphdr *iph; + const struct ipt_TTL_info *info = par->targinfo; + int new_ttl; + + if (!skb_make_writable(skb, skb->len)) + return NF_DROP; + + iph = ip_hdr(skb); + + switch (info->mode) { + 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; + } + + 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 unsigned int +hl_tg6(struct sk_buff *skb, const struct xt_target_param *par) +{ + struct ipv6hdr *ip6h; + const struct ip6t_HL_info *info = par->targinfo; + int new_hl; + + if (!skb_make_writable(skb, skb->len)) + return NF_DROP; + + ip6h = ipv6_hdr(skb); + + switch (info->mode) { + 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; + } + + ip6h->hop_limit = new_hl; + + return XT_CONTINUE; +} + +static bool ttl_tg_check(const struct xt_tgchk_param *par) +{ + const struct ipt_TTL_info *info = par->targinfo; + + if (info->mode > IPT_TTL_MAXMODE) { + printk(KERN_WARNING "ipt_TTL: invalid or unknown Mode %u\n", + info->mode); + return false; + } + if (info->mode != IPT_TTL_SET && info->ttl == 0) + return false; + return true; +} + +static bool hl_tg6_check(const struct xt_tgchk_param *par) +{ + const struct ip6t_HL_info *info = par->targinfo; + + if (info->mode > IP6T_HL_MAXMODE) { + printk(KERN_WARNING "ip6t_HL: invalid or unknown Mode %u\n", + info->mode); + return false; + } + if (info->mode != IP6T_HL_SET && info->hop_limit == 0) { + printk(KERN_WARNING "ip6t_HL: increment/decrement doesn't " + "make sense with value 0\n"); + return false; + } + return true; +} + +static struct xt_target hl_tg_reg[] __read_mostly = { + { + .name = "TTL", + .revision = 0, + .family = NFPROTO_IPV4, + .target = ttl_tg, + .targetsize = sizeof(struct ipt_TTL_info), + .table = "mangle", + .checkentry = ttl_tg_check, + .me = THIS_MODULE, + }, + { + .name = "HL", + .revision = 0, + .family = NFPROTO_IPV6, + .target = hl_tg6, + .targetsize = sizeof(struct ip6t_HL_info), + .table = "mangle", + .checkentry = hl_tg6_check, + .me = THIS_MODULE, + }, +}; + +static int __init hl_tg_init(void) +{ + return xt_register_targets(hl_tg_reg, ARRAY_SIZE(hl_tg_reg)); +} + +static void __exit hl_tg_exit(void) +{ + xt_unregister_targets(hl_tg_reg, ARRAY_SIZE(hl_tg_reg)); +} + +module_init(hl_tg_init); +module_exit(hl_tg_exit); +MODULE_ALIAS("ipt_TTL"); +MODULE_ALIAS("ip6t_HL");