diff options
Diffstat (limited to 'net/netfilter/xt_CONNMARK.c')
| -rw-r--r-- | net/netfilter/xt_CONNMARK.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/net/netfilter/xt_CONNMARK.c b/net/netfilter/xt_CONNMARK.c new file mode 100644 index 0000000..d6e5ab4 --- /dev/null +++ b/net/netfilter/xt_CONNMARK.c @@ -0,0 +1,225 @@ +/* + * 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 xt_target_param *par) +{ + const struct xt_connmark_target_info *markinfo = par->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 xt_target_param *par) +{ + const struct xt_connmark_tginfo1 *info = par->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 struct xt_tgchk_param *par) +{ + const struct xt_connmark_target_info *matchinfo = par->targinfo; + + if (matchinfo->mode == XT_CONNMARK_RESTORE) { + if (strcmp(par->table, "mangle") != 0) { + printk(KERN_WARNING "CONNMARK: restore can only be " + "called from \"mangle\" table, not \"%s\"\n", + par->table); + 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(par->family) < 0) { + printk(KERN_WARNING "can't load conntrack support for " + "proto=%u\n", par->family); + return false; + } + return true; +} + +static bool connmark_tg_check(const struct xt_tgchk_param *par) +{ + if (nf_ct_l3proto_try_module_get(par->family) < 0) { + printk(KERN_WARNING "cannot load conntrack support for " + "proto=%u\n", par->family); + return false; + } + return true; +} + +static void connmark_tg_destroy(const struct xt_tgdtor_param *par) +{ + nf_ct_l3proto_module_put(par->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_UNSPEC, + .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_UNSPEC, + .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); |
