cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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nf_conntrack_broadcast.c (1965B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *      broadcast connection tracking helper
      4 *
      5 *      (c) 2005 Patrick McHardy <kaber@trash.net>
      6 */
      7
      8#include <linux/module.h>
      9#include <linux/ip.h>
     10#include <net/route.h>
     11#include <linux/inetdevice.h>
     12#include <linux/skbuff.h>
     13
     14#include <net/netfilter/nf_conntrack.h>
     15#include <net/netfilter/nf_conntrack_helper.h>
     16#include <net/netfilter/nf_conntrack_expect.h>
     17
     18int nf_conntrack_broadcast_help(struct sk_buff *skb,
     19				struct nf_conn *ct,
     20				enum ip_conntrack_info ctinfo,
     21				unsigned int timeout)
     22{
     23	struct nf_conntrack_expect *exp;
     24	struct iphdr *iph = ip_hdr(skb);
     25	struct rtable *rt = skb_rtable(skb);
     26	struct in_device *in_dev;
     27	struct nf_conn_help *help = nfct_help(ct);
     28	__be32 mask = 0;
     29
     30	/* we're only interested in locally generated packets */
     31	if (skb->sk == NULL || !net_eq(nf_ct_net(ct), sock_net(skb->sk)))
     32		goto out;
     33	if (rt == NULL || !(rt->rt_flags & RTCF_BROADCAST))
     34		goto out;
     35	if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
     36		goto out;
     37
     38	in_dev = __in_dev_get_rcu(rt->dst.dev);
     39	if (in_dev != NULL) {
     40		const struct in_ifaddr *ifa;
     41
     42		in_dev_for_each_ifa_rcu(ifa, in_dev) {
     43			if (ifa->ifa_flags & IFA_F_SECONDARY)
     44				continue;
     45
     46			if (ifa->ifa_broadcast == iph->daddr) {
     47				mask = ifa->ifa_mask;
     48				break;
     49			}
     50		}
     51	}
     52
     53	if (mask == 0)
     54		goto out;
     55
     56	exp = nf_ct_expect_alloc(ct);
     57	if (exp == NULL)
     58		goto out;
     59
     60	exp->tuple                = ct->tuplehash[IP_CT_DIR_REPLY].tuple;
     61	exp->tuple.src.u.udp.port = help->helper->tuple.src.u.udp.port;
     62
     63	exp->mask.src.u3.ip       = mask;
     64	exp->mask.src.u.udp.port  = htons(0xFFFF);
     65
     66	exp->expectfn             = NULL;
     67	exp->flags                = NF_CT_EXPECT_PERMANENT;
     68	exp->class		  = NF_CT_EXPECT_CLASS_DEFAULT;
     69	exp->helper               = NULL;
     70
     71	nf_ct_expect_related(exp, 0);
     72	nf_ct_expect_put(exp);
     73
     74	nf_ct_refresh(ct, skb, timeout * HZ);
     75out:
     76	return NF_ACCEPT;
     77}
     78EXPORT_SYMBOL_GPL(nf_conntrack_broadcast_help);
     79
     80MODULE_LICENSE("GPL");