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- /* This kernel module is used to modify the connection mark values, or
- * to optionally restore the skb nfmark from the connection mark
- *
- * 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.
- *
- * 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@marasytems.com>");
- MODULE_DESCRIPTION("IP tables CONNMARK matching module");
- MODULE_LICENSE("GPL");
- MODULE_ALIAS("ipt_CONNMARK");
- #include <linux/netfilter/x_tables.h>
- #include <linux/netfilter/xt_CONNMARK.h>
- #include <net/netfilter/nf_conntrack_compat.h>
- #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
- #include <net/netfilter/nf_conntrack_ecache.h>
- #endif
- static unsigned int
- target(struct sk_buff **pskb,
- 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;
- u_int32_t diff;
- u_int32_t mark;
- u_int32_t newmark;
- u_int32_t ctinfo;
- u_int32_t *ctmark = nf_ct_get_mark(*pskb, &ctinfo);
- if (ctmark) {
- switch(markinfo->mode) {
- case XT_CONNMARK_SET:
- newmark = (*ctmark & ~markinfo->mask) | markinfo->mark;
- if (newmark != *ctmark) {
- *ctmark = newmark;
- #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
- ip_conntrack_event_cache(IPCT_MARK, *pskb);
- #else
- nf_conntrack_event_cache(IPCT_MARK, *pskb);
- #endif
- }
- break;
- case XT_CONNMARK_SAVE:
- newmark = (*ctmark & ~markinfo->mask) |
- ((*pskb)->mark & markinfo->mask);
- if (*ctmark != newmark) {
- *ctmark = newmark;
- #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
- ip_conntrack_event_cache(IPCT_MARK, *pskb);
- #else
- nf_conntrack_event_cache(IPCT_MARK, *pskb);
- #endif
- }
- break;
- case XT_CONNMARK_RESTORE:
- mark = (*pskb)->mark;
- diff = (*ctmark ^ mark) & markinfo->mask;
- (*pskb)->mark = mark ^ diff;
- break;
- }
- }
- return XT_CONTINUE;
- }
- static int
- checkentry(const char *tablename,
- const void *entry,
- const struct xt_target *target,
- void *targinfo,
- unsigned int hook_mask)
- {
- struct xt_connmark_target_info *matchinfo = targinfo;
- if (nf_ct_l3proto_try_module_get(target->family) < 0) {
- printk(KERN_WARNING "can't load conntrack support for "
- "proto=%d\n", target->family);
- return 0;
- }
- 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 0;
- }
- }
- if (matchinfo->mark > 0xffffffff || matchinfo->mask > 0xffffffff) {
- printk(KERN_WARNING "CONNMARK: Only supports 32bit mark\n");
- return 0;
- }
- return 1;
- }
- static void
- 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 compat_from_user(void *dst, void *src)
- {
- 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 compat_to_user(void __user *dst, void *src)
- {
- 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 xt_connmark_target[] = {
- {
- .name = "CONNMARK",
- .family = AF_INET,
- .checkentry = checkentry,
- .destroy = destroy,
- .target = target,
- .targetsize = sizeof(struct xt_connmark_target_info),
- #ifdef CONFIG_COMPAT
- .compatsize = sizeof(struct compat_xt_connmark_target_info),
- .compat_from_user = compat_from_user,
- .compat_to_user = compat_to_user,
- #endif
- .me = THIS_MODULE
- },
- {
- .name = "CONNMARK",
- .family = AF_INET6,
- .checkentry = checkentry,
- .destroy = destroy,
- .target = target,
- .targetsize = sizeof(struct xt_connmark_target_info),
- .me = THIS_MODULE
- },
- };
- static int __init xt_connmark_init(void)
- {
- return xt_register_targets(xt_connmark_target,
- ARRAY_SIZE(xt_connmark_target));
- }
- static void __exit xt_connmark_fini(void)
- {
- xt_unregister_targets(xt_connmark_target,
- ARRAY_SIZE(xt_connmark_target));
- }
- module_init(xt_connmark_init);
- module_exit(xt_connmark_fini);
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