Thomas Gleixner | 2874c5f | 2019-05-27 08:55:01 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
| 3 | * xfrm4_output.c - Common IPsec encapsulation code for IPv4. |
| 4 | * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | */ |
| 6 | |
Herbert Xu | 09b8f7a | 2006-06-22 03:08:03 -0700 | [diff] [blame] | 7 | #include <linux/if_ether.h> |
| 8 | #include <linux/kernel.h> |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 9 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/skbuff.h> |
Patrick McHardy | 16a6677 | 2006-01-06 23:01:48 -0800 | [diff] [blame] | 11 | #include <linux/netfilter_ipv4.h> |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 12 | #include <net/dst.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <net/ip.h> |
| 14 | #include <net/xfrm.h> |
| 15 | #include <net/icmp.h> |
| 16 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | static int xfrm4_tunnel_check_size(struct sk_buff *skb) |
| 18 | { |
| 19 | int mtu, ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
| 21 | if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE) |
| 22 | goto out; |
| 23 | |
WANG Cong | 60ff746 | 2014-05-04 16:39:18 -0700 | [diff] [blame] | 24 | if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->ignore_df) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | goto out; |
| 26 | |
Hannes Frederic Sowa | 5a25cf1 | 2013-08-26 12:31:19 +0200 | [diff] [blame] | 27 | mtu = dst_mtu(skb_dst(skb)); |
Steffen Klassert | d77e38e | 2017-04-14 10:06:10 +0200 | [diff] [blame] | 28 | if ((!skb_is_gso(skb) && skb->len > mtu) || |
Daniel Axtens | 80f5974 | 2018-03-01 17:13:39 +1100 | [diff] [blame] | 29 | (skb_is_gso(skb) && |
| 30 | !skb_gso_validate_network_len(skb, ip_skb_dst_mtu(skb->sk, skb)))) { |
Steffen Klassert | ca064bd | 2015-10-19 10:30:05 +0200 | [diff] [blame] | 31 | skb->protocol = htons(ETH_P_IP); |
| 32 | |
Steffen Klassert | b00897b8 | 2011-06-29 23:20:41 +0000 | [diff] [blame] | 33 | if (skb->sk) |
Hannes Frederic Sowa | 628e341 | 2013-08-14 13:05:23 +0200 | [diff] [blame] | 34 | xfrm_local_error(skb, mtu); |
Steffen Klassert | b00897b8 | 2011-06-29 23:20:41 +0000 | [diff] [blame] | 35 | else |
| 36 | icmp_send(skb, ICMP_DEST_UNREACH, |
| 37 | ICMP_FRAG_NEEDED, htonl(mtu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | ret = -EMSGSIZE; |
| 39 | } |
| 40 | out: |
| 41 | return ret; |
| 42 | } |
| 43 | |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 44 | int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | int err; |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 47 | |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 48 | err = xfrm4_tunnel_check_size(skb); |
| 49 | if (err) |
| 50 | return err; |
| 51 | |
Herbert Xu | 60d5fcf | 2007-11-19 18:47:58 -0800 | [diff] [blame] | 52 | XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol; |
| 53 | |
Herbert Xu | 36cf9ac | 2007-11-13 21:40:52 -0800 | [diff] [blame] | 54 | return xfrm4_extract_header(skb); |
| 55 | } |
| 56 | |
David Miller | 7026b1d | 2015-04-05 22:19:04 -0400 | [diff] [blame] | 57 | int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb) |
Herbert Xu | 09b8f7a | 2006-06-22 03:08:03 -0700 | [diff] [blame] | 58 | { |
Steffen Klassert | 5596732 | 2014-04-07 08:08:52 +0200 | [diff] [blame] | 59 | memset(IPCB(skb), 0, sizeof(*IPCB(skb))); |
Herbert Xu | 862b82c | 2007-11-13 21:43:11 -0800 | [diff] [blame] | 60 | |
Steffen Klassert | 5596732 | 2014-04-07 08:08:52 +0200 | [diff] [blame] | 61 | #ifdef CONFIG_NETFILTER |
Herbert Xu | 862b82c | 2007-11-13 21:43:11 -0800 | [diff] [blame] | 62 | IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED; |
Herbert Xu | 09b8f7a | 2006-06-22 03:08:03 -0700 | [diff] [blame] | 63 | #endif |
| 64 | |
David Miller | 7026b1d | 2015-04-05 22:19:04 -0400 | [diff] [blame] | 65 | return xfrm_output(sk, skb); |
Herbert Xu | 09b8f7a | 2006-06-22 03:08:03 -0700 | [diff] [blame] | 66 | } |
| 67 | |
Eric W. Biederman | 0c4b51f | 2015-09-15 20:04:18 -0500 | [diff] [blame] | 68 | static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
Steffen Klassert | 5596732 | 2014-04-07 08:08:52 +0200 | [diff] [blame] | 69 | { |
| 70 | struct xfrm_state *x = skb_dst(skb)->xfrm; |
Florian Westphal | 733a5fa | 2019-03-29 21:16:30 +0100 | [diff] [blame] | 71 | const struct xfrm_state_afinfo *afinfo; |
| 72 | int ret = -EAFNOSUPPORT; |
Steffen Klassert | 5596732 | 2014-04-07 08:08:52 +0200 | [diff] [blame] | 73 | |
| 74 | #ifdef CONFIG_NETFILTER |
| 75 | if (!x) { |
| 76 | IPCB(skb)->flags |= IPSKB_REROUTED; |
Eric W. Biederman | 13206b6 | 2015-10-07 16:48:35 -0500 | [diff] [blame] | 77 | return dst_output(net, sk, skb); |
Steffen Klassert | 5596732 | 2014-04-07 08:08:52 +0200 | [diff] [blame] | 78 | } |
| 79 | #endif |
| 80 | |
Florian Westphal | 733a5fa | 2019-03-29 21:16:30 +0100 | [diff] [blame] | 81 | rcu_read_lock(); |
Florian Westphal | c9500d7 | 2019-03-29 21:16:32 +0100 | [diff] [blame] | 82 | afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family); |
Florian Westphal | 733a5fa | 2019-03-29 21:16:30 +0100 | [diff] [blame] | 83 | if (likely(afinfo)) |
| 84 | ret = afinfo->output_finish(sk, skb); |
| 85 | else |
| 86 | kfree_skb(skb); |
| 87 | rcu_read_unlock(); |
| 88 | |
| 89 | return ret; |
Steffen Klassert | 5596732 | 2014-04-07 08:08:52 +0200 | [diff] [blame] | 90 | } |
| 91 | |
Eric W. Biederman | ede2059 | 2015-10-07 16:48:47 -0500 | [diff] [blame] | 92 | int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
Patrick McHardy | 16a6677 | 2006-01-06 23:01:48 -0800 | [diff] [blame] | 93 | { |
Eric W. Biederman | 29a26a5 | 2015-09-15 20:04:16 -0500 | [diff] [blame] | 94 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, |
| 95 | net, sk, skb, NULL, skb_dst(skb)->dev, |
| 96 | __xfrm4_output, |
Patrick McHardy | 48d5cad | 2006-02-15 15:10:22 -0800 | [diff] [blame] | 97 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
Patrick McHardy | 16a6677 | 2006-01-06 23:01:48 -0800 | [diff] [blame] | 98 | } |
Hannes Frederic Sowa | 628e341 | 2013-08-14 13:05:23 +0200 | [diff] [blame] | 99 | |
| 100 | void xfrm4_local_error(struct sk_buff *skb, u32 mtu) |
| 101 | { |
| 102 | struct iphdr *hdr; |
| 103 | |
| 104 | hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb); |
| 105 | ip_local_error(skb->sk, EMSGSIZE, hdr->daddr, |
| 106 | inet_sk(skb->sk)->inet_dport, mtu); |
| 107 | } |