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 ila_lwt_lwtunnel(struct lwtunnel_state * lwt)26 static inline struct ila_lwt *ila_lwt_lwtunnel( 27 struct lwtunnel_state *lwt) 28 { 29 return (struct ila_lwt *)lwt->data; 30 } 31 ila_params_lwtunnel(struct lwtunnel_state * lwt)32 static inline struct ila_params *ila_params_lwtunnel( 33 struct lwtunnel_state *lwt) 34 { 35 return &ila_lwt_lwtunnel(lwt)->p; 36 } 37 ila_output(struct net * net,struct sock * sk,struct sk_buff * skb)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 if (ilwt->connected) { 92 local_bh_disable(); 93 dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr); 94 local_bh_enable(); 95 } 96 } 97 98 skb_dst_set(skb, dst); 99 return dst_output(net, sk, skb); 100 101 drop: 102 kfree_skb(skb); 103 return err; 104 } 105 ila_input(struct sk_buff * skb)106 static int ila_input(struct sk_buff *skb) 107 { 108 struct dst_entry *dst = skb_dst(skb); 109 struct ila_lwt *ilwt = ila_lwt_lwtunnel(dst->lwtstate); 110 111 if (skb->protocol != htons(ETH_P_IPV6)) 112 goto drop; 113 114 if (!ilwt->lwt_output) 115 ila_update_ipv6_locator(skb, 116 ila_params_lwtunnel(dst->lwtstate), 117 false); 118 119 return dst->lwtstate->orig_input(skb); 120 121 drop: 122 kfree_skb(skb); 123 return -EINVAL; 124 } 125 126 static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = { 127 [ILA_ATTR_LOCATOR] = { .type = NLA_U64, }, 128 [ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, }, 129 [ILA_ATTR_IDENT_TYPE] = { .type = NLA_U8, }, 130 [ILA_ATTR_HOOK_TYPE] = { .type = NLA_U8, }, 131 }; 132 ila_build_state(struct net * net,struct nlattr * nla,unsigned int family,const void * cfg,struct lwtunnel_state ** ts,struct netlink_ext_ack * extack)133 static int ila_build_state(struct net *net, struct nlattr *nla, 134 unsigned int family, const void *cfg, 135 struct lwtunnel_state **ts, 136 struct netlink_ext_ack *extack) 137 { 138 struct ila_lwt *ilwt; 139 struct ila_params *p; 140 struct nlattr *tb[ILA_ATTR_MAX + 1]; 141 struct lwtunnel_state *newts; 142 const struct fib6_config *cfg6 = cfg; 143 struct ila_addr *iaddr; 144 u8 ident_type = ILA_ATYPE_USE_FORMAT; 145 u8 hook_type = ILA_HOOK_ROUTE_OUTPUT; 146 u8 csum_mode = ILA_CSUM_NO_ACTION; 147 bool lwt_output = true; 148 u8 eff_ident_type; 149 int ret; 150 151 if (family != AF_INET6) 152 return -EINVAL; 153 154 ret = nla_parse_nested_deprecated(tb, ILA_ATTR_MAX, nla, 155 ila_nl_policy, extack); 156 if (ret < 0) 157 return ret; 158 159 if (!tb[ILA_ATTR_LOCATOR]) 160 return -EINVAL; 161 162 iaddr = (struct ila_addr *)&cfg6->fc_dst; 163 164 if (tb[ILA_ATTR_IDENT_TYPE]) 165 ident_type = nla_get_u8(tb[ILA_ATTR_IDENT_TYPE]); 166 167 if (ident_type == ILA_ATYPE_USE_FORMAT) { 168 /* Infer identifier type from type field in formatted 169 * identifier. 170 */ 171 172 if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) { 173 /* Need to have full locator and at least type field 174 * included in destination 175 */ 176 return -EINVAL; 177 } 178 179 eff_ident_type = iaddr->ident.type; 180 } else { 181 eff_ident_type = ident_type; 182 } 183 184 switch (eff_ident_type) { 185 case ILA_ATYPE_IID: 186 /* Don't allow ILA for IID type */ 187 return -EINVAL; 188 case ILA_ATYPE_LUID: 189 break; 190 case ILA_ATYPE_VIRT_V4: 191 case ILA_ATYPE_VIRT_UNI_V6: 192 case ILA_ATYPE_VIRT_MULTI_V6: 193 case ILA_ATYPE_NONLOCAL_ADDR: 194 /* These ILA formats are not supported yet. */ 195 default: 196 return -EINVAL; 197 } 198 199 if (tb[ILA_ATTR_HOOK_TYPE]) 200 hook_type = nla_get_u8(tb[ILA_ATTR_HOOK_TYPE]); 201 202 switch (hook_type) { 203 case ILA_HOOK_ROUTE_OUTPUT: 204 lwt_output = true; 205 break; 206 case ILA_HOOK_ROUTE_INPUT: 207 lwt_output = false; 208 break; 209 default: 210 return -EINVAL; 211 } 212 213 if (tb[ILA_ATTR_CSUM_MODE]) 214 csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]); 215 216 if (csum_mode == ILA_CSUM_NEUTRAL_MAP && 217 ila_csum_neutral_set(iaddr->ident)) { 218 /* Don't allow translation if checksum neutral bit is 219 * configured and it's set in the SIR address. 220 */ 221 return -EINVAL; 222 } 223 224 newts = lwtunnel_state_alloc(sizeof(*ilwt)); 225 if (!newts) 226 return -ENOMEM; 227 228 ilwt = ila_lwt_lwtunnel(newts); 229 ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC); 230 if (ret) { 231 kfree(newts); 232 return ret; 233 } 234 235 ilwt->lwt_output = !!lwt_output; 236 237 p = ila_params_lwtunnel(newts); 238 239 p->csum_mode = csum_mode; 240 p->ident_type = ident_type; 241 p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]); 242 243 /* Precompute checksum difference for translation since we 244 * know both the old locator and the new one. 245 */ 246 p->locator_match = iaddr->loc; 247 248 ila_init_saved_csum(p); 249 250 newts->type = LWTUNNEL_ENCAP_ILA; 251 newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT | 252 LWTUNNEL_STATE_INPUT_REDIRECT; 253 254 if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr)) 255 ilwt->connected = 1; 256 257 *ts = newts; 258 259 return 0; 260 } 261 ila_destroy_state(struct lwtunnel_state * lwt)262 static void ila_destroy_state(struct lwtunnel_state *lwt) 263 { 264 dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache); 265 } 266 ila_fill_encap_info(struct sk_buff * skb,struct lwtunnel_state * lwtstate)267 static int ila_fill_encap_info(struct sk_buff *skb, 268 struct lwtunnel_state *lwtstate) 269 { 270 struct ila_params *p = ila_params_lwtunnel(lwtstate); 271 struct ila_lwt *ilwt = ila_lwt_lwtunnel(lwtstate); 272 273 if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64, 274 ILA_ATTR_PAD)) 275 goto nla_put_failure; 276 277 if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode)) 278 goto nla_put_failure; 279 280 if (nla_put_u8(skb, ILA_ATTR_IDENT_TYPE, (__force u8)p->ident_type)) 281 goto nla_put_failure; 282 283 if (nla_put_u8(skb, ILA_ATTR_HOOK_TYPE, 284 ilwt->lwt_output ? ILA_HOOK_ROUTE_OUTPUT : 285 ILA_HOOK_ROUTE_INPUT)) 286 goto nla_put_failure; 287 288 return 0; 289 290 nla_put_failure: 291 return -EMSGSIZE; 292 } 293 ila_encap_nlsize(struct lwtunnel_state * lwtstate)294 static int ila_encap_nlsize(struct lwtunnel_state *lwtstate) 295 { 296 return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */ 297 nla_total_size(sizeof(u8)) + /* ILA_ATTR_CSUM_MODE */ 298 nla_total_size(sizeof(u8)) + /* ILA_ATTR_IDENT_TYPE */ 299 nla_total_size(sizeof(u8)) + /* ILA_ATTR_HOOK_TYPE */ 300 0; 301 } 302 ila_encap_cmp(struct lwtunnel_state * a,struct lwtunnel_state * b)303 static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b) 304 { 305 struct ila_params *a_p = ila_params_lwtunnel(a); 306 struct ila_params *b_p = ila_params_lwtunnel(b); 307 308 return (a_p->locator.v64 != b_p->locator.v64); 309 } 310 311 static const struct lwtunnel_encap_ops ila_encap_ops = { 312 .build_state = ila_build_state, 313 .destroy_state = ila_destroy_state, 314 .output = ila_output, 315 .input = ila_input, 316 .fill_encap = ila_fill_encap_info, 317 .get_encap_size = ila_encap_nlsize, 318 .cmp_encap = ila_encap_cmp, 319 .owner = THIS_MODULE, 320 }; 321 ila_lwt_init(void)322 int ila_lwt_init(void) 323 { 324 return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA); 325 } 326 ila_lwt_fini(void)327 void ila_lwt_fini(void) 328 { 329 lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA); 330 } 331