7026b1ddb6
On the output paths in particular, we have to sometimes deal with two socket contexts. First, and usually skb->sk, is the local socket that generated the frame. And second, is potentially the socket used to control a tunneling socket, such as one the encapsulates using UDP. We do not want to disassociate skb->sk when encapsulating in order to fix this, because that would break socket memory accounting. The most extreme case where this can cause huge problems is an AF_PACKET socket transmitting over a vxlan device. We hit code paths doing checks that assume they are dealing with an ipv4 socket, but are actually operating upon the AF_PACKET one. Signed-off-by: David S. Miller <davem@davemloft.net>
174 lines
3.9 KiB
C
174 lines
3.9 KiB
C
/*
|
|
* xfrm6_output.c - Common IPsec encapsulation code for IPv6.
|
|
* Copyright (C) 2002 USAGI/WIDE Project
|
|
* Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/if_ether.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/icmpv6.h>
|
|
#include <linux/netfilter_ipv6.h>
|
|
#include <net/dst.h>
|
|
#include <net/ipv6.h>
|
|
#include <net/ip6_route.h>
|
|
#include <net/xfrm.h>
|
|
|
|
int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
|
|
u8 **prevhdr)
|
|
{
|
|
return ip6_find_1stfragopt(skb, prevhdr);
|
|
}
|
|
EXPORT_SYMBOL(xfrm6_find_1stfragopt);
|
|
|
|
static int xfrm6_local_dontfrag(struct sk_buff *skb)
|
|
{
|
|
int proto;
|
|
struct sock *sk = skb->sk;
|
|
|
|
if (sk) {
|
|
if (sk->sk_family != AF_INET6)
|
|
return 0;
|
|
|
|
proto = sk->sk_protocol;
|
|
if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
|
|
return inet6_sk(sk)->dontfrag;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
|
|
{
|
|
struct flowi6 fl6;
|
|
struct sock *sk = skb->sk;
|
|
|
|
fl6.flowi6_oif = sk->sk_bound_dev_if;
|
|
fl6.daddr = ipv6_hdr(skb)->daddr;
|
|
|
|
ipv6_local_rxpmtu(sk, &fl6, mtu);
|
|
}
|
|
|
|
void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
|
|
{
|
|
struct flowi6 fl6;
|
|
const struct ipv6hdr *hdr;
|
|
struct sock *sk = skb->sk;
|
|
|
|
hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
|
|
fl6.fl6_dport = inet_sk(sk)->inet_dport;
|
|
fl6.daddr = hdr->daddr;
|
|
|
|
ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
|
|
}
|
|
|
|
static int xfrm6_tunnel_check_size(struct sk_buff *skb)
|
|
{
|
|
int mtu, ret = 0;
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
|
|
mtu = dst_mtu(dst);
|
|
if (mtu < IPV6_MIN_MTU)
|
|
mtu = IPV6_MIN_MTU;
|
|
|
|
if (!skb->ignore_df && skb->len > mtu) {
|
|
skb->dev = dst->dev;
|
|
|
|
if (xfrm6_local_dontfrag(skb))
|
|
xfrm6_local_rxpmtu(skb, mtu);
|
|
else if (skb->sk)
|
|
xfrm_local_error(skb, mtu);
|
|
else
|
|
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
|
|
ret = -EMSGSIZE;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
int err;
|
|
|
|
err = xfrm6_tunnel_check_size(skb);
|
|
if (err)
|
|
return err;
|
|
|
|
XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
|
|
|
|
return xfrm6_extract_header(skb);
|
|
}
|
|
|
|
int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
int err;
|
|
|
|
err = xfrm_inner_extract_output(x, skb);
|
|
if (err)
|
|
return err;
|
|
|
|
skb->ignore_df = 1;
|
|
skb->protocol = htons(ETH_P_IPV6);
|
|
|
|
return x->outer_mode->output2(x, skb);
|
|
}
|
|
EXPORT_SYMBOL(xfrm6_prepare_output);
|
|
|
|
int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
|
|
#endif
|
|
|
|
return xfrm_output(sk, skb);
|
|
}
|
|
|
|
static int __xfrm6_output(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
struct xfrm_state *x = dst->xfrm;
|
|
int mtu;
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
if (!x) {
|
|
IP6CB(skb)->flags |= IP6SKB_REROUTED;
|
|
return dst_output_sk(sk, skb);
|
|
}
|
|
#endif
|
|
|
|
if (skb->protocol == htons(ETH_P_IPV6))
|
|
mtu = ip6_skb_dst_mtu(skb);
|
|
else
|
|
mtu = dst_mtu(skb_dst(skb));
|
|
|
|
if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
|
|
xfrm6_local_rxpmtu(skb, mtu);
|
|
return -EMSGSIZE;
|
|
} else if (!skb->ignore_df && skb->len > mtu && skb->sk) {
|
|
xfrm_local_error(skb, mtu);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
if (x->props.mode == XFRM_MODE_TUNNEL &&
|
|
((skb->len > mtu && !skb_is_gso(skb)) ||
|
|
dst_allfrag(skb_dst(skb)))) {
|
|
return ip6_fragment(sk, skb,
|
|
x->outer_mode->afinfo->output_finish);
|
|
}
|
|
return x->outer_mode->afinfo->output_finish(sk, skb);
|
|
}
|
|
|
|
int xfrm6_output(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, sk, skb,
|
|
NULL, skb_dst(skb)->dev, __xfrm6_output,
|
|
!(IP6CB(skb)->flags & IP6SKB_REROUTED));
|
|
}
|