1 #include <linux/errno.h> 2 #include <linux/ip.h> 3 #include <linux/kernel.h> 4 #include <linux/module.h> 5 #include <linux/skbuff.h> 6 #include <linux/socket.h> 7 #include <linux/types.h> 8 #include <net/checksum.h> 9 #include <net/dst_cache.h> 10 #include <net/ip.h> 11 #include <net/ip6_fib.h> 12 #include <net/ip6_route.h> 13 #include <net/lwtunnel.h> 14 #include <net/protocol.h> 15 #include <uapi/linux/ila.h> 16 #include "ila.h" 17 18 struct ila_lwt { 19 struct ila_params p; 20 struct dst_cache dst_cache; 21 u32 connected : 1; 22 }; 23 24 static inline struct ila_lwt *ila_lwt_lwtunnel( 25 struct lwtunnel_state *lwt) 26 { 27 return (struct ila_lwt *)lwt->data; 28 } 29 30 static inline struct ila_params *ila_params_lwtunnel( 31 struct lwtunnel_state *lwt) 32 { 33 return &ila_lwt_lwtunnel(lwt)->p; 34 } 35 36 static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb) 37 { 38 struct dst_entry *orig_dst = skb_dst(skb); 39 struct rt6_info *rt = (struct rt6_info *)orig_dst; 40 struct ila_lwt *ilwt = ila_lwt_lwtunnel(orig_dst->lwtstate); 41 struct dst_entry *dst; 42 int err = -EINVAL; 43 44 if (skb->protocol != htons(ETH_P_IPV6)) 45 goto drop; 46 47 ila_update_ipv6_locator(skb, ila_params_lwtunnel(orig_dst->lwtstate), 48 true); 49 50 if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) { 51 /* Already have a next hop address in route, no need for 52 * dest cache route. 53 */ 54 return orig_dst->lwtstate->orig_output(net, sk, skb); 55 } 56 57 dst = dst_cache_get(&ilwt->dst_cache); 58 if (unlikely(!dst)) { 59 struct ipv6hdr *ip6h = ipv6_hdr(skb); 60 struct flowi6 fl6; 61 62 /* Lookup a route for the new destination. Take into 63 * account that the base route may already have a gateway. 64 */ 65 66 memset(&fl6, 0, sizeof(fl6)); 67 fl6.flowi6_oif = orig_dst->dev->ifindex; 68 fl6.flowi6_iif = LOOPBACK_IFINDEX; 69 fl6.daddr = *rt6_nexthop((struct rt6_info *)orig_dst, 70 &ip6h->daddr); 71 72 dst = ip6_route_output(net, NULL, &fl6); 73 if (dst->error) { 74 err = -EHOSTUNREACH; 75 dst_release(dst); 76 goto drop; 77 } 78 79 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 80 if (IS_ERR(dst)) { 81 err = PTR_ERR(dst); 82 goto drop; 83 } 84 85 if (ilwt->connected) 86 dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr); 87 } 88 89 skb_dst_set(skb, dst); 90 return dst_output(net, sk, skb); 91 92 drop: 93 kfree_skb(skb); 94 return -EINVAL; 95 } 96 97 static int ila_input(struct sk_buff *skb) 98 { 99 struct dst_entry *dst = skb_dst(skb); 100 101 if (skb->protocol != htons(ETH_P_IPV6)) 102 goto drop; 103 104 ila_update_ipv6_locator(skb, ila_params_lwtunnel(dst->lwtstate), false); 105 106 return dst->lwtstate->orig_input(skb); 107 108 drop: 109 kfree_skb(skb); 110 return -EINVAL; 111 } 112 113 static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = { 114 [ILA_ATTR_LOCATOR] = { .type = NLA_U64, }, 115 [ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, }, 116 }; 117 118 static int ila_build_state(struct nlattr *nla, 119 unsigned int family, const void *cfg, 120 struct lwtunnel_state **ts) 121 { 122 struct ila_lwt *ilwt; 123 struct ila_params *p; 124 struct nlattr *tb[ILA_ATTR_MAX + 1]; 125 struct lwtunnel_state *newts; 126 const struct fib6_config *cfg6 = cfg; 127 struct ila_addr *iaddr; 128 int ret; 129 130 if (family != AF_INET6) 131 return -EINVAL; 132 133 if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) { 134 /* Need to have full locator and at least type field 135 * included in destination 136 */ 137 return -EINVAL; 138 } 139 140 iaddr = (struct ila_addr *)&cfg6->fc_dst; 141 142 if (!ila_addr_is_ila(iaddr) || ila_csum_neutral_set(iaddr->ident)) { 143 /* Don't allow translation for a non-ILA address or checksum 144 * neutral flag to be set. 145 */ 146 return -EINVAL; 147 } 148 149 ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, NULL); 150 if (ret < 0) 151 return ret; 152 153 if (!tb[ILA_ATTR_LOCATOR]) 154 return -EINVAL; 155 156 newts = lwtunnel_state_alloc(sizeof(*ilwt)); 157 if (!newts) 158 return -ENOMEM; 159 160 ilwt = ila_lwt_lwtunnel(newts); 161 ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC); 162 if (ret) { 163 kfree(newts); 164 return ret; 165 } 166 167 p = ila_params_lwtunnel(newts); 168 169 p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]); 170 171 /* Precompute checksum difference for translation since we 172 * know both the old locator and the new one. 173 */ 174 p->locator_match = iaddr->loc; 175 p->csum_diff = compute_csum_diff8( 176 (__be32 *)&p->locator_match, (__be32 *)&p->locator); 177 178 if (tb[ILA_ATTR_CSUM_MODE]) 179 p->csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]); 180 181 ila_init_saved_csum(p); 182 183 newts->type = LWTUNNEL_ENCAP_ILA; 184 newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT | 185 LWTUNNEL_STATE_INPUT_REDIRECT; 186 187 if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr)) 188 ilwt->connected = 1; 189 190 *ts = newts; 191 192 return 0; 193 } 194 195 static void ila_destroy_state(struct lwtunnel_state *lwt) 196 { 197 dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache); 198 } 199 200 static int ila_fill_encap_info(struct sk_buff *skb, 201 struct lwtunnel_state *lwtstate) 202 { 203 struct ila_params *p = ila_params_lwtunnel(lwtstate); 204 205 if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64, 206 ILA_ATTR_PAD)) 207 goto nla_put_failure; 208 if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode)) 209 goto nla_put_failure; 210 211 return 0; 212 213 nla_put_failure: 214 return -EMSGSIZE; 215 } 216 217 static int ila_encap_nlsize(struct lwtunnel_state *lwtstate) 218 { 219 return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */ 220 nla_total_size(sizeof(u8)) + /* ILA_ATTR_CSUM_MODE */ 221 0; 222 } 223 224 static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) 225 { 226 struct ila_params *a_p = ila_params_lwtunnel(a); 227 struct ila_params *b_p = ila_params_lwtunnel(b); 228 229 return (a_p->locator.v64 != b_p->locator.v64); 230 } 231 232 static const struct lwtunnel_encap_ops ila_encap_ops = { 233 .build_state = ila_build_state, 234 .destroy_state = ila_destroy_state, 235 .output = ila_output, 236 .input = ila_input, 237 .fill_encap = ila_fill_encap_info, 238 .get_encap_size = ila_encap_nlsize, 239 .cmp_encap = ila_encap_cmp, 240 .owner = THIS_MODULE, 241 }; 242 243 int ila_lwt_init(void) 244 { 245 return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA); 246 } 247 248 void ila_lwt_fini(void) 249 { 250 lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA); 251 } 252