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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xfrm6_output.c (2718B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
      4 * Copyright (C) 2002 USAGI/WIDE Project
      5 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
      6 */
      7
      8#include <linux/if_ether.h>
      9#include <linux/kernel.h>
     10#include <linux/module.h>
     11#include <linux/skbuff.h>
     12#include <linux/icmpv6.h>
     13#include <linux/netfilter_ipv6.h>
     14#include <net/dst.h>
     15#include <net/ipv6.h>
     16#include <net/ip6_route.h>
     17#include <net/xfrm.h>
     18
     19void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
     20{
     21	struct flowi6 fl6;
     22	struct sock *sk = skb->sk;
     23
     24	fl6.flowi6_oif = sk->sk_bound_dev_if;
     25	fl6.daddr = ipv6_hdr(skb)->daddr;
     26
     27	ipv6_local_rxpmtu(sk, &fl6, mtu);
     28}
     29
     30void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
     31{
     32	struct flowi6 fl6;
     33	const struct ipv6hdr *hdr;
     34	struct sock *sk = skb->sk;
     35
     36	hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
     37	fl6.fl6_dport = inet_sk(sk)->inet_dport;
     38	fl6.daddr = hdr->daddr;
     39
     40	ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
     41}
     42
     43static int __xfrm6_output_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
     44{
     45	return xfrm_output(sk, skb);
     46}
     47
     48static int xfrm6_noneed_fragment(struct sk_buff *skb)
     49{
     50	struct frag_hdr *fh;
     51	u8 prevhdr = ipv6_hdr(skb)->nexthdr;
     52
     53	if (prevhdr != NEXTHDR_FRAGMENT)
     54		return 0;
     55	fh = (struct frag_hdr *)(skb->data + sizeof(struct ipv6hdr));
     56	if (fh->nexthdr == NEXTHDR_ESP || fh->nexthdr == NEXTHDR_AUTH)
     57		return 1;
     58	return 0;
     59}
     60
     61static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
     62{
     63	struct dst_entry *dst = skb_dst(skb);
     64	struct xfrm_state *x = dst->xfrm;
     65	unsigned int mtu;
     66	bool toobig;
     67
     68#ifdef CONFIG_NETFILTER
     69	if (!x) {
     70		IP6CB(skb)->flags |= IP6SKB_REROUTED;
     71		return dst_output(net, sk, skb);
     72	}
     73#endif
     74
     75	if (x->props.mode != XFRM_MODE_TUNNEL)
     76		goto skip_frag;
     77
     78	if (skb->protocol == htons(ETH_P_IPV6))
     79		mtu = ip6_skb_dst_mtu(skb);
     80	else
     81		mtu = dst_mtu(skb_dst(skb));
     82
     83	toobig = skb->len > mtu && !skb_is_gso(skb);
     84
     85	if (toobig && xfrm6_local_dontfrag(skb->sk)) {
     86		xfrm6_local_rxpmtu(skb, mtu);
     87		kfree_skb(skb);
     88		return -EMSGSIZE;
     89	} else if (toobig && xfrm6_noneed_fragment(skb)) {
     90		skb->ignore_df = 1;
     91		goto skip_frag;
     92	} else if (!skb->ignore_df && toobig && skb->sk) {
     93		xfrm_local_error(skb, mtu);
     94		kfree_skb(skb);
     95		return -EMSGSIZE;
     96	}
     97
     98	if (toobig || dst_allfrag(skb_dst(skb)))
     99		return ip6_fragment(net, sk, skb,
    100				    __xfrm6_output_finish);
    101
    102skip_frag:
    103	return xfrm_output(sk, skb);
    104}
    105
    106int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
    107{
    108	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
    109			    net, sk, skb,  skb->dev, skb_dst(skb)->dev,
    110			    __xfrm6_output,
    111			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
    112}