- 论坛徽章:
- 0
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static int
match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const struct xt_match *match,
const void *matchinfo,
int offset,
unsigned int protoff,
int *hotdrop)
{
const struct xt_conntrack_info *sinfo = matchinfo;
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
unsigned int statebit;
ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
#define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
if (ct == &nf_conntrack_untracked)
statebit = XT_CONNTRACK_STATE_UNTRACKED;
else if (ct)
statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
else
statebit = XT_CONNTRACK_STATE_INVALID;
if(sinfo->flags & XT_CONNTRACK_STATE) {
if (ct) {
if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip !=
ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip)
statebit |= XT_CONNTRACK_STATE_SNAT;
if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip !=
ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip)
statebit |= XT_CONNTRACK_STATE_DNAT;
}
if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE))
return 0;
}
if(sinfo->flags & XT_CONNTRACK_PROTO) {
if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, XT_CONNTRACK_PROTO))
return 0;
}
if(sinfo->flags & XT_CONNTRACK_ORIGSRC) {
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))
return 0;
}
if(sinfo->flags & XT_CONNTRACK_ORIGDST) {
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))
return 0;
}
if(sinfo->flags & XT_CONNTRACK_REPLSRC) {
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))
return 0;
}
if(sinfo->flags & XT_CONNTRACK_REPLDST) {
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))
return 0;
}
if(sinfo->flags & XT_CONNTRACK_STATUS) {
if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS))
return 0;
}
if(sinfo->flags & XT_CONNTRACK_EXPIRES) {
unsigned long expires;
if(!ct)
return 0;
expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;
if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), XT_CONNTRACK_EXPIRES))
return 0;
}
return 1;
} |
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