diff options
Diffstat (limited to 'net/netfilter/xt_CONNMARK.c')
| -rw-r--r-- | net/netfilter/xt_CONNMARK.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/net/netfilter/xt_CONNMARK.c b/net/netfilter/xt_CONNMARK.c new file mode 100644 index 0000000000000..22506e376be5b --- /dev/null +++ b/net/netfilter/xt_CONNMARK.c @@ -0,0 +1,141 @@ +/* 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> + +static unsigned int +target(struct sk_buff **pskb, + const struct net_device *in, + const struct net_device *out, + unsigned int hooknum, + const void *targinfo, + void *userinfo) +{ + const struct xt_connmark_target_info *markinfo = targinfo; + u_int32_t diff; + u_int32_t nfmark; + 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; + break; + case XT_CONNMARK_SAVE: + newmark = (*ctmark & ~markinfo->mask) | ((*pskb)->nfmark & markinfo->mask); + if (*ctmark != newmark) + *ctmark = newmark; + break; + case XT_CONNMARK_RESTORE: + nfmark = (*pskb)->nfmark; + diff = (*ctmark ^ nfmark) & markinfo->mask; + if (diff != 0) + (*pskb)->nfmark = nfmark ^ diff; + break; + } + } + + return XT_CONTINUE; +} + +static int +checkentry(const char *tablename, + const void *entry, + void *targinfo, + unsigned int targinfosize, + unsigned int hook_mask) +{ + struct xt_connmark_target_info *matchinfo = targinfo; + if (targinfosize != XT_ALIGN(sizeof(struct xt_connmark_target_info))) { + printk(KERN_WARNING "CONNMARK: targinfosize %u != %Zu\n", + targinfosize, + XT_ALIGN(sizeof(struct xt_connmark_target_info))); + 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 struct xt_target connmark_reg = { + .name = "CONNMARK", + .target = &target, + .checkentry = &checkentry, + .me = THIS_MODULE +}; +static struct xt_target connmark6_reg = { + .name = "CONNMARK", + .target = &target, + .checkentry = &checkentry, + .me = THIS_MODULE +}; + +static int __init init(void) +{ + int ret; + + need_conntrack(); + + ret = xt_register_target(AF_INET, &connmark_reg); + if (ret) + return ret; + + ret = xt_register_target(AF_INET6, &connmark6_reg); + if (ret) + xt_unregister_target(AF_INET, &connmark_reg); + + return ret; +} + +static void __exit fini(void) +{ + xt_unregister_target(AF_INET, &connmark_reg); + xt_unregister_target(AF_INET6, &connmark6_reg); +} + +module_init(init); +module_exit(fini); |