net: dsa: Fix dsa_is_user_port() test inversion
[muen/linux.git] / net / ipv6 / xfrm6_mode_tunnel.c
1 /*
2  * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
3  *
4  * Copyright (C) 2002 USAGI/WIDE Project
5  * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
6  */
7
8 #include <linux/gfp.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/skbuff.h>
13 #include <linux/stringify.h>
14 #include <net/dsfield.h>
15 #include <net/dst.h>
16 #include <net/inet_ecn.h>
17 #include <net/ip6_route.h>
18 #include <net/ipv6.h>
19 #include <net/xfrm.h>
20
21 static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
22 {
23         struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
24
25         if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
26                 IP6_ECN_set_ce(skb, inner_iph);
27 }
28
29 /* Add encapsulation header.
30  *
31  * The top IP header will be constructed per RFC 2401.
32  */
33 static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
34 {
35         struct dst_entry *dst = skb_dst(skb);
36         struct ipv6hdr *top_iph;
37         int dsfield;
38
39         skb_set_inner_network_header(skb, skb_network_offset(skb));
40         skb_set_inner_transport_header(skb, skb_transport_offset(skb));
41
42         skb_set_network_header(skb, -x->props.header_len);
43         skb->mac_header = skb->network_header +
44                           offsetof(struct ipv6hdr, nexthdr);
45         skb->transport_header = skb->network_header + sizeof(*top_iph);
46         top_iph = ipv6_hdr(skb);
47
48         top_iph->version = 6;
49
50         memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
51                sizeof(top_iph->flow_lbl));
52         top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
53
54         if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
55                 dsfield = 0;
56         else
57                 dsfield = XFRM_MODE_SKB_CB(skb)->tos;
58         dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
59         if (x->props.flags & XFRM_STATE_NOECN)
60                 dsfield &= ~INET_ECN_MASK;
61         ipv6_change_dsfield(top_iph, 0, dsfield);
62         top_iph->hop_limit = ip6_dst_hoplimit(xfrm_dst_child(dst));
63         top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
64         top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
65         return 0;
66 }
67
68 #define for_each_input_rcu(head, handler)       \
69         for (handler = rcu_dereference(head);   \
70              handler != NULL;                   \
71              handler = rcu_dereference(handler->next))
72
73
74 static int xfrm6_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_IPV6)
79                 goto out;
80         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
81                 goto out;
82
83         err = skb_unclone(skb, GFP_ATOMIC);
84         if (err)
85                 goto out;
86
87         if (x->props.flags & XFRM_STATE_DECAP_DSCP)
88                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
89                                ipipv6_hdr(skb));
90         if (!(x->props.flags & XFRM_STATE_NOECN))
91                 ipip6_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 *xfrm6_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 xfrm6_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 + sizeof(struct ipv6hdr);
117
118         skb_reset_mac_len(skb);
119         pskb_pull(skb, skb->mac_len + x->props.header_len);
120 }
121
122 static struct xfrm_mode xfrm6_tunnel_mode = {
123         .input2 = xfrm6_mode_tunnel_input,
124         .input = xfrm_prepare_input,
125         .output2 = xfrm6_mode_tunnel_output,
126         .output = xfrm6_prepare_output,
127         .gso_segment = xfrm6_mode_tunnel_gso_segment,
128         .xmit = xfrm6_mode_tunnel_xmit,
129         .owner = THIS_MODULE,
130         .encap = XFRM_MODE_TUNNEL,
131         .flags = XFRM_MODE_FLAG_TUNNEL,
132 };
133
134 static int __init xfrm6_mode_tunnel_init(void)
135 {
136         return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
137 }
138
139 static void __exit xfrm6_mode_tunnel_exit(void)
140 {
141         int err;
142
143         err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
144         BUG_ON(err);
145 }
146
147 module_init(xfrm6_mode_tunnel_init);
148 module_exit(xfrm6_mode_tunnel_exit);
149 MODULE_LICENSE("GPL");
150 MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);