1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/errno.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/skbuff.h>
7 #include <linux/socket.h>
8 #include <linux/types.h>
9 #include <net/checksum.h>
10 #include <net/dst_cache.h>
12 #include <net/ip6_fib.h>
13 #include <net/ip6_route.h>
14 #include <net/lwtunnel.h>
15 #include <net/protocol.h>
16 #include <uapi/linux/ila.h>
21 struct dst_cache dst_cache;
25 static inline struct ila_lwt *ila_lwt_lwtunnel(
26 struct lwtunnel_state *lwt)
28 return (struct ila_lwt *)lwt->data;
31 static inline struct ila_params *ila_params_lwtunnel(
32 struct lwtunnel_state *lwt)
34 return &ila_lwt_lwtunnel(lwt)->p;
37 static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
39 struct dst_entry *orig_dst = skb_dst(skb);
40 struct rt6_info *rt = (struct rt6_info *)orig_dst;
41 struct ila_lwt *ilwt = ila_lwt_lwtunnel(orig_dst->lwtstate);
42 struct dst_entry *dst;
45 if (skb->protocol != htons(ETH_P_IPV6))
48 ila_update_ipv6_locator(skb, ila_params_lwtunnel(orig_dst->lwtstate),
51 if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) {
52 /* Already have a next hop address in route, no need for
55 return orig_dst->lwtstate->orig_output(net, sk, skb);
58 dst = dst_cache_get(&ilwt->dst_cache);
60 struct ipv6hdr *ip6h = ipv6_hdr(skb);
63 /* Lookup a route for the new destination. Take into
64 * account that the base route may already have a gateway.
67 memset(&fl6, 0, sizeof(fl6));
68 fl6.flowi6_oif = orig_dst->dev->ifindex;
69 fl6.flowi6_iif = LOOPBACK_IFINDEX;
70 fl6.daddr = *rt6_nexthop((struct rt6_info *)orig_dst,
73 dst = ip6_route_output(net, NULL, &fl6);
80 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
87 dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr);
90 skb_dst_set(skb, dst);
91 return dst_output(net, sk, skb);
98 static int ila_input(struct sk_buff *skb)
100 struct dst_entry *dst = skb_dst(skb);
102 if (skb->protocol != htons(ETH_P_IPV6))
105 ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate), false);
107 return dst->lwtstate->orig_input(skb);
114 static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
115 [ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
116 [ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
119 static int ila_build_state(struct nlattr *nla,
120 unsigned int family, const void *cfg,
121 struct lwtunnel_state **ts,
122 struct netlink_ext_ack *extack)
124 struct ila_lwt *ilwt;
125 struct ila_params *p;
126 struct nlattr *tb[ILA_ATTR_MAX + 1];
127 struct lwtunnel_state *newts;
128 const struct fib6_config *cfg6 = cfg;
129 struct ila_addr *iaddr;
132 if (family != AF_INET6)
135 if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) {
136 /* Need to have full locator and at least type field
137 * included in destination
142 iaddr = (struct ila_addr *)&cfg6->fc_dst;
144 if (!ila_addr_is_ila(iaddr) || ila_csum_neutral_set(iaddr->ident)) {
145 /* Don't allow translation for a non-ILA address or checksum
146 * neutral flag to be set.
151 ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, extack);
155 if (!tb[ILA_ATTR_LOCATOR])
158 newts = lwtunnel_state_alloc(sizeof(*ilwt));
162 ilwt = ila_lwt_lwtunnel(newts);
163 ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC);
169 p = ila_params_lwtunnel(newts);
171 p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]);
173 /* Precompute checksum difference for translation since we
174 * know both the old locator and the new one.
176 p->locator_match = iaddr->loc;
177 p->csum_diff = compute_csum_diff8(
178 (__be32 *)&p->locator_match, (__be32 *)&p->locator);
180 if (tb[ILA_ATTR_CSUM_MODE])
181 p->csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]);
183 ila_init_saved_csum(p);
185 newts->type = LWTUNNEL_ENCAP_ILA;
186 newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT |
187 LWTUNNEL_STATE_INPUT_REDIRECT;
189 if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr))
197 static void ila_destroy_state(struct lwtunnel_state *lwt)
199 dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache);
202 static int ila_fill_encap_info(struct sk_buff *skb,
203 struct lwtunnel_state *lwtstate)
205 struct ila_params *p = ila_params_lwtunnel(lwtstate);
207 if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64,
209 goto nla_put_failure;
210 if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode))
211 goto nla_put_failure;
219 static int ila_encap_nlsize(struct lwtunnel_state *lwtstate)
221 return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */
222 nla_total_size(sizeof(u8)) + /* ILA_ATTR_CSUM_MODE */
226 static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
228 struct ila_params *a_p = ila_params_lwtunnel(a);
229 struct ila_params *b_p = ila_params_lwtunnel(b);
231 return (a_p->locator.v64 != b_p->locator.v64);
234 static const struct lwtunnel_encap_ops ila_encap_ops = {
235 .build_state = ila_build_state,
236 .destroy_state = ila_destroy_state,
237 .output = ila_output,
239 .fill_encap = ila_fill_encap_info,
240 .get_encap_size = ila_encap_nlsize,
241 .cmp_encap = ila_encap_cmp,
242 .owner = THIS_MODULE,
245 int ila_lwt_init(void)
247 return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
250 void ila_lwt_fini(void)
252 lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);