mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-30 08:02:30 +00:00
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>
111 lines
2.5 KiB
C
111 lines
2.5 KiB
C
/*
|
|
* xfrm4_output.c - Common IPsec encapsulation code for IPv4.
|
|
* 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/netfilter_ipv4.h>
|
|
#include <net/dst.h>
|
|
#include <net/ip.h>
|
|
#include <net/xfrm.h>
|
|
#include <net/icmp.h>
|
|
|
|
static int xfrm4_tunnel_check_size(struct sk_buff *skb)
|
|
{
|
|
int mtu, ret = 0;
|
|
|
|
if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
|
|
goto out;
|
|
|
|
if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->ignore_df)
|
|
goto out;
|
|
|
|
mtu = dst_mtu(skb_dst(skb));
|
|
if (skb->len > mtu) {
|
|
if (skb->sk)
|
|
xfrm_local_error(skb, mtu);
|
|
else
|
|
icmp_send(skb, ICMP_DEST_UNREACH,
|
|
ICMP_FRAG_NEEDED, htonl(mtu));
|
|
ret = -EMSGSIZE;
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
int err;
|
|
|
|
err = xfrm4_tunnel_check_size(skb);
|
|
if (err)
|
|
return err;
|
|
|
|
XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
|
|
|
|
return xfrm4_extract_header(skb);
|
|
}
|
|
|
|
int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
int err;
|
|
|
|
err = xfrm_inner_extract_output(x, skb);
|
|
if (err)
|
|
return err;
|
|
|
|
IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
|
|
skb->protocol = htons(ETH_P_IP);
|
|
|
|
return x->outer_mode->output2(x, skb);
|
|
}
|
|
EXPORT_SYMBOL(xfrm4_prepare_output);
|
|
|
|
int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
|
|
#endif
|
|
|
|
return xfrm_output(sk, skb);
|
|
}
|
|
|
|
static int __xfrm4_output(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct xfrm_state *x = skb_dst(skb)->xfrm;
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
if (!x) {
|
|
IPCB(skb)->flags |= IPSKB_REROUTED;
|
|
return dst_output_sk(sk, skb);
|
|
}
|
|
#endif
|
|
|
|
return x->outer_mode->afinfo->output_finish(sk, skb);
|
|
}
|
|
|
|
int xfrm4_output(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, sk, skb,
|
|
NULL, skb_dst(skb)->dev, __xfrm4_output,
|
|
!(IPCB(skb)->flags & IPSKB_REROUTED));
|
|
}
|
|
|
|
void xfrm4_local_error(struct sk_buff *skb, u32 mtu)
|
|
{
|
|
struct iphdr *hdr;
|
|
|
|
hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
|
|
ip_local_error(skb->sk, EMSGSIZE, hdr->daddr,
|
|
inet_sk(skb->sk)->inet_dport, mtu);
|
|
}
|