1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/errno.h> 3 #include <linux/ip.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> 11 #include <net/ip.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> 17 #include "ila.h" 18 19 struct ila_lwt { 20 struct ila_params p; 21 struct dst_cache dst_cache; 22 u32 connected : 1; 23 u32 lwt_output : 1; 24 }; 25 26 static inline struct ila_lwt *ila_lwt_lwtunnel( 27 struct lwtunnel_state *lwt) 28 { 29 return (struct ila_lwt *)lwt->data; 30 } 31 32 static inline struct ila_params *ila_params_lwtunnel( 33 struct lwtunnel_state *lwt) 34 { 35 return &ila_lwt_lwtunnel(lwt)->p; 36 } 37 38 static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb) 39 { 40 struct dst_entry *orig_dst = skb_dst(skb); 41 struct rt6_info *rt = dst_rt6_info(orig_dst); 42 struct ila_lwt *ilwt = ila_lwt_lwtunnel(orig_dst->lwtstate); 43 struct dst_entry *dst; 44 int err = -EINVAL; 45 46 if (skb->protocol != htons(ETH_P_IPV6)) 47 goto drop; 48 49 if (ilwt->lwt_output) 50 ila_update_ipv6_locator(skb, 51 ila_params_lwtunnel(orig_dst->lwtstate), 52 true); 53 54 if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) { 55 /* Already have a next hop address in route, no need for 56 * dest cache route. 57 */ 58 return orig_dst->lwtstate->orig_output(net, sk, skb); 59 } 60 61 local_bh_disable(); 62 dst = dst_cache_get(&ilwt->dst_cache); 63 local_bh_enable(); 64 if (unlikely(!dst)) { 65 struct ipv6hdr *ip6h = ipv6_hdr(skb); 66 struct flowi6 fl6; 67 68 /* Lookup a route for the new destination. Take into 69 * account that the base route may already have a gateway. 70 */ 71 72 memset(&fl6, 0, sizeof(fl6)); 73 fl6.flowi6_oif = orig_dst->dev->ifindex; 74 fl6.flowi6_iif = LOOPBACK_IFINDEX; 75 fl6.daddr = *rt6_nexthop(dst_rt6_info(orig_dst), 76 &ip6h->daddr); 77 78 dst = ip6_route_output(net, NULL, &fl6); 79 if (dst->error) { 80 err = -EHOSTUNREACH; 81 dst_release(dst); 82 goto drop; 83 } 84 85 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 86 if (IS_ERR(dst)) { 87 err = PTR_ERR(dst); 88 goto drop; 89 } 90 91 /* cache only if we don't create a dst reference loop */ 92 if (ilwt->connected && orig_dst->lwtstate != dst->lwtstate) { 93 local_bh_disable(); 94 dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr); 95 local_bh_enable(); 96 } 97 } 98 99 skb_dst_drop(skb); 100 skb_dst_set(skb, dst); 101 return dst_output(net, sk, skb); 102 103 drop: 104 kfree_skb(skb); 105 return err; 106 } 107 108 static int ila_input(struct sk_buff *skb) 109 { 110 struct dst_entry *dst = skb_dst(skb); 111 struct ila_lwt *ilwt = ila_lwt_lwtunnel(dst->lwtstate); 112 113 if (skb->protocol != htons(ETH_P_IPV6)) 114 goto drop; 115 116 if (!ilwt->lwt_output) 117 ila_update_ipv6_locator(skb, 118 ila_params_lwtunnel(dst->lwtstate), 119 false); 120 121 return dst->lwtstate->orig_input(skb); 122 123 drop: 124 kfree_skb(skb); 125 return -EINVAL; 126 } 127 128 static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = { 129 [ILA_ATTR_LOCATOR] = { .type = NLA_U64, }, 130 [ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, }, 131 [ILA_ATTR_IDENT_TYPE] = { .type = NLA_U8, }, 132 [ILA_ATTR_HOOK_TYPE] = { .type = NLA_U8, }, 133 }; 134 135 static int ila_build_state(struct net *net, struct nlattr *nla, 136 unsigned int family, const void *cfg, 137 struct lwtunnel_state **ts, 138 struct netlink_ext_ack *extack) 139 { 140 struct ila_lwt *ilwt; 141 struct ila_params *p; 142 struct nlattr *tb[ILA_ATTR_MAX + 1]; 143 struct lwtunnel_state *newts; 144 const struct fib6_config *cfg6 = cfg; 145 struct ila_addr *iaddr; 146 u8 ident_type = ILA_ATYPE_USE_FORMAT; 147 u8 hook_type = ILA_HOOK_ROUTE_OUTPUT; 148 u8 csum_mode = ILA_CSUM_NO_ACTION; 149 bool lwt_output = true; 150 u8 eff_ident_type; 151 int ret; 152 153 if (family != AF_INET6) 154 return -EINVAL; 155 156 ret = nla_parse_nested_deprecated(tb, ILA_ATTR_MAX, nla, 157 ila_nl_policy, extack); 158 if (ret < 0) 159 return ret; 160 161 if (!tb[ILA_ATTR_LOCATOR]) 162 return -EINVAL; 163 164 iaddr = (struct ila_addr *)&cfg6->fc_dst; 165 166 if (tb[ILA_ATTR_IDENT_TYPE]) 167 ident_type = nla_get_u8(tb[ILA_ATTR_IDENT_TYPE]); 168 169 if (ident_type == ILA_ATYPE_USE_FORMAT) { 170 /* Infer identifier type from type field in formatted 171 * identifier. 172 */ 173 174 if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) { 175 /* Need to have full locator and at least type field 176 * included in destination 177 */ 178 return -EINVAL; 179 } 180 181 eff_ident_type = iaddr->ident.type; 182 } else { 183 eff_ident_type = ident_type; 184 } 185 186 switch (eff_ident_type) { 187 case ILA_ATYPE_IID: 188 /* Don't allow ILA for IID type */ 189 return -EINVAL; 190 case ILA_ATYPE_LUID: 191 break; 192 case ILA_ATYPE_VIRT_V4: 193 case ILA_ATYPE_VIRT_UNI_V6: 194 case ILA_ATYPE_VIRT_MULTI_V6: 195 case ILA_ATYPE_NONLOCAL_ADDR: 196 /* These ILA formats are not supported yet. */ 197 default: 198 return -EINVAL; 199 } 200 201 if (tb[ILA_ATTR_HOOK_TYPE]) 202 hook_type = nla_get_u8(tb[ILA_ATTR_HOOK_TYPE]); 203 204 switch (hook_type) { 205 case ILA_HOOK_ROUTE_OUTPUT: 206 lwt_output = true; 207 break; 208 case ILA_HOOK_ROUTE_INPUT: 209 lwt_output = false; 210 break; 211 default: 212 return -EINVAL; 213 } 214 215 if (tb[ILA_ATTR_CSUM_MODE]) 216 csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]); 217 218 if (csum_mode == ILA_CSUM_NEUTRAL_MAP && 219 ila_csum_neutral_set(iaddr->ident)) { 220 /* Don't allow translation if checksum neutral bit is 221 * configured and it's set in the SIR address. 222 */ 223 return -EINVAL; 224 } 225 226 newts = lwtunnel_state_alloc(sizeof(*ilwt)); 227 if (!newts) 228 return -ENOMEM; 229 230 ilwt = ila_lwt_lwtunnel(newts); 231 ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC); 232 if (ret) { 233 kfree(newts); 234 return ret; 235 } 236 237 ilwt->lwt_output = !!lwt_output; 238 239 p = ila_params_lwtunnel(newts); 240 241 p->csum_mode = csum_mode; 242 p->ident_type = ident_type; 243 p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]); 244 245 /* Precompute checksum difference for translation since we 246 * know both the old locator and the new one. 247 */ 248 p->locator_match = iaddr->loc; 249 250 ila_init_saved_csum(p); 251 252 newts->type = LWTUNNEL_ENCAP_ILA; 253 newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT | 254 LWTUNNEL_STATE_INPUT_REDIRECT; 255 256 if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr)) 257 ilwt->connected = 1; 258 259 *ts = newts; 260 261 return 0; 262 } 263 264 static void ila_destroy_state(struct lwtunnel_state *lwt) 265 { 266 dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache); 267 } 268 269 static int ila_fill_encap_info(struct sk_buff *skb, 270 struct lwtunnel_state *lwtstate) 271 { 272 struct ila_params *p = ila_params_lwtunnel(lwtstate); 273 struct ila_lwt *ilwt = ila_lwt_lwtunnel(lwtstate); 274 275 if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64, 276 ILA_ATTR_PAD)) 277 goto nla_put_failure; 278 279 if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode)) 280 goto nla_put_failure; 281 282 if (nla_put_u8(skb, ILA_ATTR_IDENT_TYPE, (__force u8)p->ident_type)) 283 goto nla_put_failure; 284 285 if (nla_put_u8(skb, ILA_ATTR_HOOK_TYPE, 286 ilwt->lwt_output ? ILA_HOOK_ROUTE_OUTPUT : 287 ILA_HOOK_ROUTE_INPUT)) 288 goto nla_put_failure; 289 290 return 0; 291 292 nla_put_failure: 293 return -EMSGSIZE; 294 } 295 296 static int ila_encap_nlsize(struct lwtunnel_state *lwtstate) 297 { 298 return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */ 299 nla_total_size(sizeof(u8)) + /* ILA_ATTR_CSUM_MODE */ 300 nla_total_size(sizeof(u8)) + /* ILA_ATTR_IDENT_TYPE */ 301 nla_total_size(sizeof(u8)) + /* ILA_ATTR_HOOK_TYPE */ 302 0; 303 } 304 305 static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) 306 { 307 struct ila_params *a_p = ila_params_lwtunnel(a); 308 struct ila_params *b_p = ila_params_lwtunnel(b); 309 310 return (a_p->locator.v64 != b_p->locator.v64); 311 } 312 313 static const struct lwtunnel_encap_ops ila_encap_ops = { 314 .build_state = ila_build_state, 315 .destroy_state = ila_destroy_state, 316 .output = ila_output, 317 .input = ila_input, 318 .fill_encap = ila_fill_encap_info, 319 .get_encap_size = ila_encap_nlsize, 320 .cmp_encap = ila_encap_cmp, 321 .owner = THIS_MODULE, 322 }; 323 324 int ila_lwt_init(void) 325 { 326 return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA); 327 } 328 329 void ila_lwt_fini(void) 330 { 331 lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA); 332 } 333