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https://github.com/Fishwaldo/Star64_linux.git
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0c4b51f005
This is immediately motivated by the bridge code that chains functions that call into netfilter. Without passing net into the okfns the bridge code would need to guess about the best expression for the network namespace to process packets in. As net is frequently one of the first things computed in continuation functions after netfilter has done it's job passing in the desired network namespace is in many cases a code simplification. To support this change the function dst_output_okfn is introduced to simplify passing dst_output as an okfn. For the moment dst_output_okfn just silently drops the struct net. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
113 lines
2.6 KiB
C
113 lines
2.6 KiB
C
/*
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* xfrm4_output.c - Common IPsec encapsulation code for IPv4.
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* Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/if_ether.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter_ipv4.h>
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#include <net/dst.h>
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#include <net/ip.h>
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#include <net/xfrm.h>
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#include <net/icmp.h>
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static int xfrm4_tunnel_check_size(struct sk_buff *skb)
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{
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int mtu, ret = 0;
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if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
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goto out;
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if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->ignore_df)
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goto out;
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mtu = dst_mtu(skb_dst(skb));
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if (skb->len > mtu) {
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if (skb->sk)
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xfrm_local_error(skb, mtu);
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else
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icmp_send(skb, ICMP_DEST_UNREACH,
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ICMP_FRAG_NEEDED, htonl(mtu));
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ret = -EMSGSIZE;
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}
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out:
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return ret;
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}
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int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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int err;
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err = xfrm4_tunnel_check_size(skb);
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if (err)
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return err;
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XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
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return xfrm4_extract_header(skb);
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}
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int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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int err;
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err = xfrm_inner_extract_output(x, skb);
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if (err)
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return err;
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IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
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skb->protocol = htons(ETH_P_IP);
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return x->outer_mode->output2(x, skb);
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}
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EXPORT_SYMBOL(xfrm4_prepare_output);
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int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb)
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{
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memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
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#ifdef CONFIG_NETFILTER
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IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
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#endif
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return xfrm_output(sk, skb);
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}
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static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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struct xfrm_state *x = skb_dst(skb)->xfrm;
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#ifdef CONFIG_NETFILTER
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if (!x) {
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IPCB(skb)->flags |= IPSKB_REROUTED;
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return dst_output(sk, skb);
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}
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#endif
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return x->outer_mode->afinfo->output_finish(sk, skb);
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}
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int xfrm4_output(struct sock *sk, struct sk_buff *skb)
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{
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struct net *net = dev_net(skb_dst(skb)->dev);
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return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
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net, sk, skb, NULL, skb_dst(skb)->dev,
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__xfrm4_output,
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!(IPCB(skb)->flags & IPSKB_REROUTED));
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}
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void xfrm4_local_error(struct sk_buff *skb, u32 mtu)
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{
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struct iphdr *hdr;
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hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
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ip_local_error(skb->sk, EMSGSIZE, hdr->daddr,
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inet_sk(skb->sk)->inet_dport, mtu);
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}
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