cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

netfilter.c (2639B)

      1/*
      2 * IPv4 specific functions of netfilter core
      3 *
      4 * Rusty Russell (C) 2000 -- This code is GPL.
      5 * Patrick McHardy (C) 2006-2012
      6 */
      7#include <linux/kernel.h>
      8#include <linux/netfilter.h>
      9#include <linux/netfilter_ipv4.h>
     10#include <linux/ip.h>
     11#include <linux/skbuff.h>
     12#include <linux/gfp.h>
     13#include <linux/export.h>
     14#include <net/route.h>
     15#include <net/xfrm.h>
     16#include <net/ip.h>
     17#include <net/netfilter/nf_queue.h>
     18
     19/* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */
     20int ip_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb, unsigned int addr_type)
     21{
     22	const struct iphdr *iph = ip_hdr(skb);
     23	struct rtable *rt;
     24	struct flowi4 fl4 = {};
     25	__be32 saddr = iph->saddr;
     26	__u8 flags;
     27	struct net_device *dev = skb_dst(skb)->dev;
     28	struct flow_keys flkeys;
     29	unsigned int hh_len;
     30
     31	sk = sk_to_full_sk(sk);
     32	flags = sk ? inet_sk_flowi_flags(sk) : 0;
     33
     34	if (addr_type == RTN_UNSPEC)
     35		addr_type = inet_addr_type_dev_table(net, dev, saddr);
     36	if (addr_type == RTN_LOCAL || addr_type == RTN_UNICAST)
     37		flags |= FLOWI_FLAG_ANYSRC;
     38	else
     39		saddr = 0;
     40
     41	/* some non-standard hacks like ipt_REJECT.c:send_reset() can cause
     42	 * packets with foreign saddr to appear on the NF_INET_LOCAL_OUT hook.
     43	 */
     44	fl4.daddr = iph->daddr;
     45	fl4.saddr = saddr;
     46	fl4.flowi4_tos = RT_TOS(iph->tos);
     47	fl4.flowi4_oif = sk ? sk->sk_bound_dev_if : 0;
     48	fl4.flowi4_l3mdev = l3mdev_master_ifindex(dev);
     49	fl4.flowi4_mark = skb->mark;
     50	fl4.flowi4_flags = flags;
     51	fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys);
     52	rt = ip_route_output_key(net, &fl4);
     53	if (IS_ERR(rt))
     54		return PTR_ERR(rt);
     55
     56	/* Drop old route. */
     57	skb_dst_drop(skb);
     58	skb_dst_set(skb, &rt->dst);
     59
     60	if (skb_dst(skb)->error)
     61		return skb_dst(skb)->error;
     62
     63#ifdef CONFIG_XFRM
     64	if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
     65	    xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) {
     66		struct dst_entry *dst = skb_dst(skb);
     67		skb_dst_set(skb, NULL);
     68		dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0);
     69		if (IS_ERR(dst))
     70			return PTR_ERR(dst);
     71		skb_dst_set(skb, dst);
     72	}
     73#endif
     74
     75	/* Change in oif may mean change in hh_len. */
     76	hh_len = skb_dst(skb)->dev->hard_header_len;
     77	if (skb_headroom(skb) < hh_len &&
     78	    pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
     79				0, GFP_ATOMIC))
     80		return -ENOMEM;
     81
     82	return 0;
     83}
     84EXPORT_SYMBOL(ip_route_me_harder);
     85
     86int nf_ip_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
     87		bool strict __always_unused)
     88{
     89	struct rtable *rt = ip_route_output_key(net, &fl->u.ip4);
     90	if (IS_ERR(rt))
     91		return PTR_ERR(rt);
     92	*dst = &rt->dst;
     93	return 0;
     94}
     95EXPORT_SYMBOL_GPL(nf_ip_route);