net: dsa: Fix dsa_is_user_port() test inversion
[muen/linux.git] / net / ipv4 / xfrm4_mode_tunnel.c
1 /*
2  * xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4.
3  *
4  * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
5  */
6
7 #include <linux/gfp.h>
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/skbuff.h>
12 #include <linux/stringify.h>
13 #include <net/dst.h>
14 #include <net/inet_ecn.h>
15 #include <net/ip.h>
16 #include <net/xfrm.h>
17
18 static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
19 {
20         struct iphdr *inner_iph = ipip_hdr(skb);
21
22         if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
23                 IP_ECN_set_ce(inner_iph);
24 }
25
26 /* Add encapsulation header.
27  *
28  * The top IP header will be constructed per RFC 2401.
29  */
30 static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
31 {
32         struct dst_entry *dst = skb_dst(skb);
33         struct iphdr *top_iph;
34         int flags;
35
36         skb_set_inner_network_header(skb, skb_network_offset(skb));
37         skb_set_inner_transport_header(skb, skb_transport_offset(skb));
38
39         skb_set_network_header(skb, -x->props.header_len);
40         skb->mac_header = skb->network_header +
41                           offsetof(struct iphdr, protocol);
42         skb->transport_header = skb->network_header + sizeof(*top_iph);
43         top_iph = ip_hdr(skb);
44
45         top_iph->ihl = 5;
46         top_iph->version = 4;
47
48         top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);
49
50         /* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
51         if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
52                 top_iph->tos = 0;
53         else
54                 top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
55         top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
56                                             XFRM_MODE_SKB_CB(skb)->tos);
57
58         flags = x->props.flags;
59         if (flags & XFRM_STATE_NOECN)
60                 IP_ECN_clear(top_iph);
61
62         top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
63                 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
64
65         top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst));
66
67         top_iph->saddr = x->props.saddr.a4;
68         top_iph->daddr = x->id.daddr.a4;
69         ip_select_ident(dev_net(dst->dev), skb, NULL);
70
71         return 0;
72 }
73
74 static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
75 {
76         int err = -EINVAL;
77
78         if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
79                 goto out;
80
81         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
82                 goto out;
83
84         err = skb_unclone(skb, GFP_ATOMIC);
85         if (err)
86                 goto out;
87
88         if (x->props.flags & XFRM_STATE_DECAP_DSCP)
89                 ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
90         if (!(x->props.flags & XFRM_STATE_NOECN))
91                 ipip_ecn_decapsulate(skb);
92
93         skb_reset_network_header(skb);
94         skb_mac_header_rebuild(skb);
95         eth_hdr(skb)->h_proto = skb->protocol;
96
97         err = 0;
98
99 out:
100         return err;
101 }
102
103 static struct sk_buff *xfrm4_mode_tunnel_gso_segment(struct xfrm_state *x,
104                                                      struct sk_buff *skb,
105                                                      netdev_features_t features)
106 {
107         __skb_push(skb, skb->mac_len);
108         return skb_mac_gso_segment(skb, features);
109 }
110
111 static void xfrm4_mode_tunnel_xmit(struct xfrm_state *x, struct sk_buff *skb)
112 {
113         struct xfrm_offload *xo = xfrm_offload(skb);
114
115         if (xo->flags & XFRM_GSO_SEGMENT)
116                 skb->transport_header = skb->network_header +
117                                         sizeof(struct iphdr);
118
119         skb_reset_mac_len(skb);
120         pskb_pull(skb, skb->mac_len + x->props.header_len);
121 }
122
123 static struct xfrm_mode xfrm4_tunnel_mode = {
124         .input2 = xfrm4_mode_tunnel_input,
125         .input = xfrm_prepare_input,
126         .output2 = xfrm4_mode_tunnel_output,
127         .output = xfrm4_prepare_output,
128         .gso_segment = xfrm4_mode_tunnel_gso_segment,
129         .xmit = xfrm4_mode_tunnel_xmit,
130         .owner = THIS_MODULE,
131         .encap = XFRM_MODE_TUNNEL,
132         .flags = XFRM_MODE_FLAG_TUNNEL,
133 };
134
135 static int __init xfrm4_mode_tunnel_init(void)
136 {
137         return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET);
138 }
139
140 static void __exit xfrm4_mode_tunnel_exit(void)
141 {
142         int err;
143
144         err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET);
145         BUG_ON(err);
146 }
147
148 module_init(xfrm4_mode_tunnel_init);
149 module_exit(xfrm4_mode_tunnel_exit);
150 MODULE_LICENSE("GPL");
151 MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL);