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 = (struct 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 dst = dst_cache_get(&ilwt->dst_cache); 62 if (unlikely(!dst)) { 63 struct ipv6hdr *ip6h = ipv6_hdr(skb); 64 struct flowi6 fl6; 65 66 /* Lookup a route for the new destination. Take into 67 * account that the base route may already have a gateway. 68 */ 69 70 memset(&fl6, 0, sizeof(fl6)); 71 fl6.flowi6_oif = orig_dst->dev->ifindex; 72 fl6.flowi6_iif = LOOPBACK_IFINDEX; 73 fl6.daddr = *rt6_nexthop((struct rt6_info *)orig_dst, 74 &ip6h->daddr); 75 76 dst = ip6_route_output(net, NULL, &fl6); 77 if (dst->error) { 78 err = -EHOSTUNREACH; 79 dst_release(dst); 80 goto drop; 81 } 82 83 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 84 if (IS_ERR(dst)) { 85 err = PTR_ERR(dst); 86 goto drop; 87 } 88 89 if (ilwt->connected) 90 dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr); 91 } 92 93 skb_dst_set(skb, dst); 94 return dst_output(net, sk, skb); 95 96 drop: 97 kfree_skb(skb); 98 return err; 99 } 100 101 static int ila_input(struct sk_buff *skb) 102 { 103 struct dst_entry *dst = skb_dst(skb); 104 struct ila_lwt *ilwt = ila_lwt_lwtunnel(dst->lwtstate); 105 106 if (skb->protocol != htons(ETH_P_IPV6)) 107 goto drop; 108 109 if (!ilwt->lwt_output) 110 ila_update_ipv6_locator(skb, 111 ila_params_lwtunnel(dst->lwtstate), 112 false); 113 114 return dst->lwtstate->orig_input(skb); 115 116 drop: 117 kfree_skb(skb); 118 return -EINVAL; 119 } 120 121 static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = { 122 [ILA_ATTR_LOCATOR] = { .type = NLA_U64, }, 123 [ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, }, 124 [ILA_ATTR_IDENT_TYPE] = { .type = NLA_U8, }, 125 [ILA_ATTR_HOOK_TYPE] = { .type = NLA_U8, }, 126 }; 127 128 static int ila_build_state(struct nlattr *nla, 129 unsigned int family, const void *cfg, 130 struct lwtunnel_state **ts, 131 struct netlink_ext_ack *extack) 132 { 133 struct ila_lwt *ilwt; 134 struct ila_params *p; 135 struct nlattr *tb[ILA_ATTR_MAX + 1]; 136 struct lwtunnel_state *newts; 137 const struct fib6_config *cfg6 = cfg; 138 struct ila_addr *iaddr; 139 u8 ident_type = ILA_ATYPE_USE_FORMAT; 140 u8 hook_type = ILA_HOOK_ROUTE_OUTPUT; 141 u8 csum_mode = ILA_CSUM_NO_ACTION; 142 bool lwt_output = true; 143 u8 eff_ident_type; 144 int ret; 145 146 if (family != AF_INET6) 147 return -EINVAL; 148 149 ret = nla_parse_nested(tb, ILA_ATTR_MAX, nla, ila_nl_policy, extack); 150 if (ret < 0) 151 return ret; 152 153 if (!tb[ILA_ATTR_LOCATOR]) 154 return -EINVAL; 155 156 iaddr = (struct ila_addr *)&cfg6->fc_dst; 157 158 if (tb[ILA_ATTR_IDENT_TYPE]) 159 ident_type = nla_get_u8(tb[ILA_ATTR_IDENT_TYPE]); 160 161 if (ident_type == ILA_ATYPE_USE_FORMAT) { 162 /* Infer identifier type from type field in formatted 163 * identifier. 164 */ 165 166 if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) { 167 /* Need to have full locator and at least type field 168 * included in destination 169 */ 170 return -EINVAL; 171 } 172 173 eff_ident_type = iaddr->ident.type; 174 } else { 175 eff_ident_type = ident_type; 176 } 177 178 switch (eff_ident_type) { 179 case ILA_ATYPE_IID: 180 /* Don't allow ILA for IID type */ 181 return -EINVAL; 182 case ILA_ATYPE_LUID: 183 break; 184 case ILA_ATYPE_VIRT_V4: 185 case ILA_ATYPE_VIRT_UNI_V6: 186 case ILA_ATYPE_VIRT_MULTI_V6: 187 case ILA_ATYPE_NONLOCAL_ADDR: 188 /* These ILA formats are not supported yet. */ 189 default: 190 return -EINVAL; 191 } 192 193 if (tb[ILA_ATTR_HOOK_TYPE]) 194 hook_type = nla_get_u8(tb[ILA_ATTR_HOOK_TYPE]); 195 196 switch (hook_type) { 197 case ILA_HOOK_ROUTE_OUTPUT: 198 lwt_output = true; 199 break; 200 case ILA_HOOK_ROUTE_INPUT: 201 lwt_output = false; 202 break; 203 default: 204 return -EINVAL; 205 } 206 207 if (tb[ILA_ATTR_CSUM_MODE]) 208 csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]); 209 210 if (csum_mode == ILA_CSUM_NEUTRAL_MAP && 211 ila_csum_neutral_set(iaddr->ident)) { 212 /* Don't allow translation if checksum neutral bit is 213 * configured and it's set in the SIR address. 214 */ 215 return -EINVAL; 216 } 217 218 newts = lwtunnel_state_alloc(sizeof(*ilwt)); 219 if (!newts) 220 return -ENOMEM; 221 222 ilwt = ila_lwt_lwtunnel(newts); 223 ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC); 224 if (ret) { 225 kfree(newts); 226 return ret; 227 } 228 229 ilwt->lwt_output = !!lwt_output; 230 231 p = ila_params_lwtunnel(newts); 232 233 p->csum_mode = csum_mode; 234 p->ident_type = ident_type; 235 p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]); 236 237 /* Precompute checksum difference for translation since we 238 * know both the old locator and the new one. 239 */ 240 p->locator_match = iaddr->loc; 241 242 ila_init_saved_csum(p); 243 244 newts->type = LWTUNNEL_ENCAP_ILA; 245 newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT | 246 LWTUNNEL_STATE_INPUT_REDIRECT; 247 248 if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr)) 249 ilwt->connected = 1; 250 251 *ts = newts; 252 253 return 0; 254 } 255 256 static void ila_destroy_state(struct lwtunnel_state *lwt) 257 { 258 dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache); 259 } 260 261 static int ila_fill_encap_info(struct sk_buff *skb, 262 struct lwtunnel_state *lwtstate) 263 { 264 struct ila_params *p = ila_params_lwtunnel(lwtstate); 265 struct ila_lwt *ilwt = ila_lwt_lwtunnel(lwtstate); 266 267 if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64, 268 ILA_ATTR_PAD)) 269 goto nla_put_failure; 270 271 if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode)) 272 goto nla_put_failure; 273 274 if (nla_put_u8(skb, ILA_ATTR_IDENT_TYPE, (__force u8)p->ident_type)) 275 goto nla_put_failure; 276 277 if (nla_put_u8(skb, ILA_ATTR_HOOK_TYPE, 278 ilwt->lwt_output ? ILA_HOOK_ROUTE_OUTPUT : 279 ILA_HOOK_ROUTE_INPUT)) 280 goto nla_put_failure; 281 282 return 0; 283 284 nla_put_failure: 285 return -EMSGSIZE; 286 } 287 288 static int ila_encap_nlsize(struct lwtunnel_state *lwtstate) 289 { 290 return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */ 291 nla_total_size(sizeof(u8)) + /* ILA_ATTR_CSUM_MODE */ 292 nla_total_size(sizeof(u8)) + /* ILA_ATTR_IDENT_TYPE */ 293 nla_total_size(sizeof(u8)) + /* ILA_ATTR_HOOK_TYPE */ 294 0; 295 } 296 297 static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) 298 { 299 struct ila_params *a_p = ila_params_lwtunnel(a); 300 struct ila_params *b_p = ila_params_lwtunnel(b); 301 302 return (a_p->locator.v64 != b_p->locator.v64); 303 } 304 305 static const struct lwtunnel_encap_ops ila_encap_ops = { 306 .build_state = ila_build_state, 307 .destroy_state = ila_destroy_state, 308 .output = ila_output, 309 .input = ila_input, 310 .fill_encap = ila_fill_encap_info, 311 .get_encap_size = ila_encap_nlsize, 312 .cmp_encap = ila_encap_cmp, 313 .owner = THIS_MODULE, 314 }; 315 316 int ila_lwt_init(void) 317 { 318 return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA); 319 } 320 321 void ila_lwt_fini(void) 322 { 323 lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA); 324 } 325