| /* |
| * xt_CONNMARK - Netfilter module to modify the connection mark values |
| * |
| * Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com> |
| * by Henrik Nordstrom <hno@marasystems.com> |
| * Copyright © CC Computer Consultants GmbH, 2007 - 2008 |
| * Jan Engelhardt <jengelh@computergmbh.de> |
| * |
| * 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. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| #include <linux/module.h> |
| #include <linux/skbuff.h> |
| #include <linux/ip.h> |
| #include <net/checksum.h> |
| |
| MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>"); |
| MODULE_DESCRIPTION("Xtables: connection mark modification"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("ipt_CONNMARK"); |
| MODULE_ALIAS("ip6t_CONNMARK"); |
| |
| #include <linux/netfilter/x_tables.h> |
| #include <linux/netfilter/xt_CONNMARK.h> |
| #include <net/netfilter/nf_conntrack_ecache.h> |
| |
| static unsigned int |
| connmark_tg_v0(struct sk_buff *skb, const struct net_device *in, |
| const struct net_device *out, unsigned int hooknum, |
| const struct xt_target *target, const void *targinfo) |
| { |
| const struct xt_connmark_target_info *markinfo = targinfo; |
| struct nf_conn *ct; |
| enum ip_conntrack_info ctinfo; |
| u_int32_t diff; |
| u_int32_t mark; |
| u_int32_t newmark; |
| |
| ct = nf_ct_get(skb, &ctinfo); |
| if (ct) { |
| switch(markinfo->mode) { |
| case XT_CONNMARK_SET: |
| newmark = (ct->mark & ~markinfo->mask) | markinfo->mark; |
| if (newmark != ct->mark) { |
| ct->mark = newmark; |
| nf_conntrack_event_cache(IPCT_MARK, ct); |
| } |
| break; |
| case XT_CONNMARK_SAVE: |
| newmark = (ct->mark & ~markinfo->mask) | |
| (skb->mark & markinfo->mask); |
| if (ct->mark != newmark) { |
| ct->mark = newmark; |
| nf_conntrack_event_cache(IPCT_MARK, ct); |
| } |
| break; |
| case XT_CONNMARK_RESTORE: |
| mark = skb->mark; |
| diff = (ct->mark ^ mark) & markinfo->mask; |
| skb->mark = mark ^ diff; |
| break; |
| } |
| } |
| |
| return XT_CONTINUE; |
| } |
| |
| static unsigned int |
| connmark_tg(struct sk_buff *skb, const struct net_device *in, |
| const struct net_device *out, unsigned int hooknum, |
| const struct xt_target *target, const void *targinfo) |
| { |
| const struct xt_connmark_tginfo1 *info = targinfo; |
| enum ip_conntrack_info ctinfo; |
| struct nf_conn *ct; |
| u_int32_t newmark; |
| |
| ct = nf_ct_get(skb, &ctinfo); |
| if (ct == NULL) |
| return XT_CONTINUE; |
| |
| switch (info->mode) { |
| case XT_CONNMARK_SET: |
| newmark = (ct->mark & ~info->ctmask) ^ info->ctmark; |
| if (ct->mark != newmark) { |
| ct->mark = newmark; |
| nf_conntrack_event_cache(IPCT_MARK, ct); |
| } |
| break; |
| case XT_CONNMARK_SAVE: |
| newmark = (ct->mark & ~info->ctmask) ^ |
| (skb->mark & info->nfmask); |
| if (ct->mark != newmark) { |
| ct->mark = newmark; |
| nf_conntrack_event_cache(IPCT_MARK, ct); |
| } |
| break; |
| case XT_CONNMARK_RESTORE: |
| newmark = (skb->mark & ~info->nfmask) ^ |
| (ct->mark & info->ctmask); |
| skb->mark = newmark; |
| break; |
| } |
| |
| return XT_CONTINUE; |
| } |
| |
| static bool |
| connmark_tg_check_v0(const char *tablename, const void *entry, |
| const struct xt_target *target, void *targinfo, |
| unsigned int hook_mask) |
| { |
| const struct xt_connmark_target_info *matchinfo = targinfo; |
| |
| if (matchinfo->mode == XT_CONNMARK_RESTORE) { |
| if (strcmp(tablename, "mangle") != 0) { |
| printk(KERN_WARNING "CONNMARK: restore can only be " |
| "called from \"mangle\" table, not \"%s\"\n", |
| tablename); |
| return false; |
| } |
| } |
| if (matchinfo->mark > 0xffffffff || matchinfo->mask > 0xffffffff) { |
| printk(KERN_WARNING "CONNMARK: Only supports 32bit mark\n"); |
| return false; |
| } |
| if (nf_ct_l3proto_try_module_get(target->family) < 0) { |
| printk(KERN_WARNING "can't load conntrack support for " |
| "proto=%u\n", target->family); |
| return false; |
| } |
| return true; |
| } |
| |
| static bool |
| connmark_tg_check(const char *tablename, const void *entry, |
| const struct xt_target *target, void *targinfo, |
| unsigned int hook_mask) |
| { |
| if (nf_ct_l3proto_try_module_get(target->family) < 0) { |
| printk(KERN_WARNING "cannot load conntrack support for " |
| "proto=%u\n", target->family); |
| return false; |
| } |
| return true; |
| } |
| |
| static void |
| connmark_tg_destroy(const struct xt_target *target, void *targinfo) |
| { |
| nf_ct_l3proto_module_put(target->family); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| struct compat_xt_connmark_target_info { |
| compat_ulong_t mark, mask; |
| u_int8_t mode; |
| u_int8_t __pad1; |
| u_int16_t __pad2; |
| }; |
| |
| static void connmark_tg_compat_from_user_v0(void *dst, void *src) |
| { |
| const struct compat_xt_connmark_target_info *cm = src; |
| struct xt_connmark_target_info m = { |
| .mark = cm->mark, |
| .mask = cm->mask, |
| .mode = cm->mode, |
| }; |
| memcpy(dst, &m, sizeof(m)); |
| } |
| |
| static int connmark_tg_compat_to_user_v0(void __user *dst, void *src) |
| { |
| const struct xt_connmark_target_info *m = src; |
| struct compat_xt_connmark_target_info cm = { |
| .mark = m->mark, |
| .mask = m->mask, |
| .mode = m->mode, |
| }; |
| return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0; |
| } |
| #endif /* CONFIG_COMPAT */ |
| |
| static struct xt_target connmark_tg_reg[] __read_mostly = { |
| { |
| .name = "CONNMARK", |
| .revision = 0, |
| .family = NFPROTO_IPV4, |
| .checkentry = connmark_tg_check_v0, |
| .destroy = connmark_tg_destroy, |
| .target = connmark_tg_v0, |
| .targetsize = sizeof(struct xt_connmark_target_info), |
| #ifdef CONFIG_COMPAT |
| .compatsize = sizeof(struct compat_xt_connmark_target_info), |
| .compat_from_user = connmark_tg_compat_from_user_v0, |
| .compat_to_user = connmark_tg_compat_to_user_v0, |
| #endif |
| .me = THIS_MODULE |
| }, |
| { |
| .name = "CONNMARK", |
| .revision = 0, |
| .family = NFPROTO_IPV6, |
| .checkentry = connmark_tg_check_v0, |
| .destroy = connmark_tg_destroy, |
| .target = connmark_tg_v0, |
| .targetsize = sizeof(struct xt_connmark_target_info), |
| #ifdef CONFIG_COMPAT |
| .compatsize = sizeof(struct compat_xt_connmark_target_info), |
| .compat_from_user = connmark_tg_compat_from_user_v0, |
| .compat_to_user = connmark_tg_compat_to_user_v0, |
| #endif |
| .me = THIS_MODULE |
| }, |
| { |
| .name = "CONNMARK", |
| .revision = 1, |
| .family = NFPROTO_IPV4, |
| .checkentry = connmark_tg_check, |
| .target = connmark_tg, |
| .targetsize = sizeof(struct xt_connmark_tginfo1), |
| .destroy = connmark_tg_destroy, |
| .me = THIS_MODULE, |
| }, |
| { |
| .name = "CONNMARK", |
| .revision = 1, |
| .family = NFPROTO_IPV6, |
| .checkentry = connmark_tg_check, |
| .target = connmark_tg, |
| .targetsize = sizeof(struct xt_connmark_tginfo1), |
| .destroy = connmark_tg_destroy, |
| .me = THIS_MODULE, |
| }, |
| }; |
| |
| static int __init connmark_tg_init(void) |
| { |
| return xt_register_targets(connmark_tg_reg, |
| ARRAY_SIZE(connmark_tg_reg)); |
| } |
| |
| static void __exit connmark_tg_exit(void) |
| { |
| xt_unregister_targets(connmark_tg_reg, ARRAY_SIZE(connmark_tg_reg)); |
| } |
| |
| module_init(connmark_tg_init); |
| module_exit(connmark_tg_exit); |