efa741656e
The size is verified by x_tables and isn't needed by the modules anymore. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
254 lines
7.4 KiB
C
254 lines
7.4 KiB
C
/* Kernel module to match connection tracking information.
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* Superset of Rusty's minimalistic state match.
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*
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* (C) 2001 Marc Boucher (marc@mbsi.ca).
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
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#include <linux/netfilter_ipv4/ip_conntrack.h>
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#include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
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#else
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#include <net/netfilter/nf_conntrack.h>
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#endif
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_conntrack.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
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MODULE_DESCRIPTION("iptables connection tracking match module");
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MODULE_ALIAS("ipt_conntrack");
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#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
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static int
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match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const struct xt_match *match,
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const void *matchinfo,
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int offset,
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unsigned int protoff,
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int *hotdrop)
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{
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const struct xt_conntrack_info *sinfo = matchinfo;
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struct ip_conntrack *ct;
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enum ip_conntrack_info ctinfo;
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unsigned int statebit;
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ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
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#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
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if (ct == &ip_conntrack_untracked)
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statebit = XT_CONNTRACK_STATE_UNTRACKED;
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else if (ct)
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statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
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else
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statebit = XT_CONNTRACK_STATE_INVALID;
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if(sinfo->flags & XT_CONNTRACK_STATE) {
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if (ct) {
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if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip !=
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ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip)
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statebit |= XT_CONNTRACK_STATE_SNAT;
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if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip !=
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ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip)
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statebit |= XT_CONNTRACK_STATE_DNAT;
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}
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if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_PROTO) {
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if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, XT_CONNTRACK_PROTO))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_ORIGSRC) {
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if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, XT_CONNTRACK_ORIGSRC))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_ORIGDST) {
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if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, XT_CONNTRACK_ORIGDST))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_REPLSRC) {
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if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, XT_CONNTRACK_REPLSRC))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_REPLDST) {
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if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, XT_CONNTRACK_REPLDST))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_STATUS) {
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if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_EXPIRES) {
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unsigned long expires;
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if(!ct)
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return 0;
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expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;
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if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), XT_CONNTRACK_EXPIRES))
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return 0;
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}
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return 1;
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}
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#else /* CONFIG_IP_NF_CONNTRACK */
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static int
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match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const struct xt_match *match,
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const void *matchinfo,
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int offset,
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unsigned int protoff,
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int *hotdrop)
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{
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const struct xt_conntrack_info *sinfo = matchinfo;
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struct nf_conn *ct;
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enum ip_conntrack_info ctinfo;
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unsigned int statebit;
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ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
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#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
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if (ct == &nf_conntrack_untracked)
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statebit = XT_CONNTRACK_STATE_UNTRACKED;
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else if (ct)
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statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
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else
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statebit = XT_CONNTRACK_STATE_INVALID;
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if(sinfo->flags & XT_CONNTRACK_STATE) {
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if (ct) {
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if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip !=
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ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip)
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statebit |= XT_CONNTRACK_STATE_SNAT;
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if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip !=
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ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip)
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statebit |= XT_CONNTRACK_STATE_DNAT;
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}
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if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_PROTO) {
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if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, XT_CONNTRACK_PROTO))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_ORIGSRC) {
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if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, XT_CONNTRACK_ORIGSRC))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_ORIGDST) {
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if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, XT_CONNTRACK_ORIGDST))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_REPLSRC) {
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if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, XT_CONNTRACK_REPLSRC))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_REPLDST) {
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if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, XT_CONNTRACK_REPLDST))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_STATUS) {
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if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS))
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return 0;
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}
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if(sinfo->flags & XT_CONNTRACK_EXPIRES) {
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unsigned long expires;
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if(!ct)
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return 0;
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expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;
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if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), XT_CONNTRACK_EXPIRES))
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return 0;
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}
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return 1;
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}
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#endif /* CONFIG_NF_IP_CONNTRACK */
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static int
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checkentry(const char *tablename,
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const void *ip,
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const struct xt_match *match,
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void *matchinfo,
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unsigned int hook_mask)
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{
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#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
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if (nf_ct_l3proto_try_module_get(match->family) < 0) {
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printk(KERN_WARNING "can't load nf_conntrack support for "
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"proto=%d\n", match->family);
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return 0;
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}
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#endif
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return 1;
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}
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static void
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destroy(const struct xt_match *match, void *matchinfo)
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{
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#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
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nf_ct_l3proto_module_put(match->family);
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#endif
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}
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static struct xt_match conntrack_match = {
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.name = "conntrack",
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.match = match,
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.checkentry = checkentry,
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.destroy = destroy,
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.matchsize = sizeof(struct xt_conntrack_info),
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.family = AF_INET,
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.me = THIS_MODULE,
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};
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static int __init xt_conntrack_init(void)
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{
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need_conntrack();
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return xt_register_match(&conntrack_match);
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}
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static void __exit xt_conntrack_fini(void)
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{
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xt_unregister_match(&conntrack_match);
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}
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module_init(xt_conntrack_init);
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module_exit(xt_conntrack_fini);
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