1 /* 2 * SR-IPv6 implementation 3 * 4 * Author: 5 * David Lebrun <david.lebrun@uclouvain.be> 6 * 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 #include <linux/errno.h> 15 #include <linux/types.h> 16 #include <linux/socket.h> 17 #include <linux/net.h> 18 #include <linux/in6.h> 19 #include <linux/slab.h> 20 21 #include <net/ipv6.h> 22 #include <net/protocol.h> 23 24 #include <net/seg6.h> 25 #include <net/genetlink.h> 26 #include <linux/seg6.h> 27 #include <linux/seg6_genl.h> 28 #ifdef CONFIG_IPV6_SEG6_HMAC 29 #include <net/seg6_hmac.h> 30 #endif 31 32 bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len) 33 { 34 int trailing; 35 unsigned int tlv_offset; 36 37 if (srh->type != IPV6_SRCRT_TYPE_4) 38 return false; 39 40 if (((srh->hdrlen + 1) << 3) != len) 41 return false; 42 43 if (srh->segments_left != srh->first_segment) 44 return false; 45 46 tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4); 47 48 trailing = len - tlv_offset; 49 if (trailing < 0) 50 return false; 51 52 while (trailing) { 53 struct sr6_tlv *tlv; 54 unsigned int tlv_len; 55 56 tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset); 57 tlv_len = sizeof(*tlv) + tlv->len; 58 59 trailing -= tlv_len; 60 if (trailing < 0) 61 return false; 62 63 tlv_offset += tlv_len; 64 } 65 66 return true; 67 } 68 69 static struct genl_family seg6_genl_family; 70 71 static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = { 72 [SEG6_ATTR_DST] = { .type = NLA_BINARY, 73 .len = sizeof(struct in6_addr) }, 74 [SEG6_ATTR_DSTLEN] = { .type = NLA_S32, }, 75 [SEG6_ATTR_HMACKEYID] = { .type = NLA_U32, }, 76 [SEG6_ATTR_SECRET] = { .type = NLA_BINARY, }, 77 [SEG6_ATTR_SECRETLEN] = { .type = NLA_U8, }, 78 [SEG6_ATTR_ALGID] = { .type = NLA_U8, }, 79 [SEG6_ATTR_HMACINFO] = { .type = NLA_NESTED, }, 80 }; 81 82 #ifdef CONFIG_IPV6_SEG6_HMAC 83 84 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info) 85 { 86 struct net *net = genl_info_net(info); 87 struct seg6_pernet_data *sdata; 88 struct seg6_hmac_info *hinfo; 89 u32 hmackeyid; 90 char *secret; 91 int err = 0; 92 u8 algid; 93 u8 slen; 94 95 sdata = seg6_pernet(net); 96 97 if (!info->attrs[SEG6_ATTR_HMACKEYID] || 98 !info->attrs[SEG6_ATTR_SECRETLEN] || 99 !info->attrs[SEG6_ATTR_ALGID]) 100 return -EINVAL; 101 102 hmackeyid = nla_get_u32(info->attrs[SEG6_ATTR_HMACKEYID]); 103 slen = nla_get_u8(info->attrs[SEG6_ATTR_SECRETLEN]); 104 algid = nla_get_u8(info->attrs[SEG6_ATTR_ALGID]); 105 106 if (hmackeyid == 0) 107 return -EINVAL; 108 109 if (slen > SEG6_HMAC_SECRET_LEN) 110 return -EINVAL; 111 112 mutex_lock(&sdata->lock); 113 hinfo = seg6_hmac_info_lookup(net, hmackeyid); 114 115 if (!slen) { 116 if (!hinfo) 117 err = -ENOENT; 118 119 err = seg6_hmac_info_del(net, hmackeyid); 120 121 goto out_unlock; 122 } 123 124 if (!info->attrs[SEG6_ATTR_SECRET]) { 125 err = -EINVAL; 126 goto out_unlock; 127 } 128 129 if (hinfo) { 130 err = seg6_hmac_info_del(net, hmackeyid); 131 if (err) 132 goto out_unlock; 133 } 134 135 secret = (char *)nla_data(info->attrs[SEG6_ATTR_SECRET]); 136 137 hinfo = kzalloc(sizeof(*hinfo), GFP_KERNEL); 138 if (!hinfo) { 139 err = -ENOMEM; 140 goto out_unlock; 141 } 142 143 memcpy(hinfo->secret, secret, slen); 144 hinfo->slen = slen; 145 hinfo->alg_id = algid; 146 hinfo->hmackeyid = hmackeyid; 147 148 err = seg6_hmac_info_add(net, hmackeyid, hinfo); 149 if (err) 150 kfree(hinfo); 151 152 out_unlock: 153 mutex_unlock(&sdata->lock); 154 return err; 155 } 156 157 #else 158 159 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info) 160 { 161 return -ENOTSUPP; 162 } 163 164 #endif 165 166 static int seg6_genl_set_tunsrc(struct sk_buff *skb, struct genl_info *info) 167 { 168 struct net *net = genl_info_net(info); 169 struct in6_addr *val, *t_old, *t_new; 170 struct seg6_pernet_data *sdata; 171 172 sdata = seg6_pernet(net); 173 174 if (!info->attrs[SEG6_ATTR_DST]) 175 return -EINVAL; 176 177 val = nla_data(info->attrs[SEG6_ATTR_DST]); 178 t_new = kmemdup(val, sizeof(*val), GFP_KERNEL); 179 if (!t_new) 180 return -ENOMEM; 181 182 mutex_lock(&sdata->lock); 183 184 t_old = sdata->tun_src; 185 rcu_assign_pointer(sdata->tun_src, t_new); 186 187 mutex_unlock(&sdata->lock); 188 189 synchronize_net(); 190 kfree(t_old); 191 192 return 0; 193 } 194 195 static int seg6_genl_get_tunsrc(struct sk_buff *skb, struct genl_info *info) 196 { 197 struct net *net = genl_info_net(info); 198 struct in6_addr *tun_src; 199 struct sk_buff *msg; 200 void *hdr; 201 202 msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 203 if (!msg) 204 return -ENOMEM; 205 206 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, 207 &seg6_genl_family, 0, SEG6_CMD_GET_TUNSRC); 208 if (!hdr) 209 goto free_msg; 210 211 rcu_read_lock(); 212 tun_src = rcu_dereference(seg6_pernet(net)->tun_src); 213 214 if (nla_put(msg, SEG6_ATTR_DST, sizeof(struct in6_addr), tun_src)) 215 goto nla_put_failure; 216 217 rcu_read_unlock(); 218 219 genlmsg_end(msg, hdr); 220 genlmsg_reply(msg, info); 221 222 return 0; 223 224 nla_put_failure: 225 rcu_read_unlock(); 226 genlmsg_cancel(msg, hdr); 227 free_msg: 228 nlmsg_free(msg); 229 return -ENOMEM; 230 } 231 232 #ifdef CONFIG_IPV6_SEG6_HMAC 233 234 static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo, 235 struct sk_buff *msg) 236 { 237 if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) || 238 nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) || 239 nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) || 240 nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id)) 241 return -1; 242 243 return 0; 244 } 245 246 static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo, 247 u32 portid, u32 seq, u32 flags, 248 struct sk_buff *skb, u8 cmd) 249 { 250 void *hdr; 251 252 hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd); 253 if (!hdr) 254 return -ENOMEM; 255 256 if (__seg6_hmac_fill_info(hinfo, skb) < 0) 257 goto nla_put_failure; 258 259 genlmsg_end(skb, hdr); 260 return 0; 261 262 nla_put_failure: 263 genlmsg_cancel(skb, hdr); 264 return -EMSGSIZE; 265 } 266 267 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 268 { 269 struct net *net = sock_net(cb->skb->sk); 270 struct seg6_pernet_data *sdata; 271 struct rhashtable_iter *iter; 272 273 sdata = seg6_pernet(net); 274 iter = (struct rhashtable_iter *)cb->args[0]; 275 276 if (!iter) { 277 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 278 if (!iter) 279 return -ENOMEM; 280 281 cb->args[0] = (long)iter; 282 } 283 284 rhashtable_walk_enter(&sdata->hmac_infos, iter); 285 286 return 0; 287 } 288 289 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 290 { 291 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; 292 293 rhashtable_walk_exit(iter); 294 295 kfree(iter); 296 297 return 0; 298 } 299 300 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 301 { 302 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; 303 struct net *net = sock_net(skb->sk); 304 struct seg6_pernet_data *sdata; 305 struct seg6_hmac_info *hinfo; 306 int ret; 307 308 sdata = seg6_pernet(net); 309 310 ret = rhashtable_walk_start(iter); 311 if (ret && ret != -EAGAIN) 312 goto done; 313 314 for (;;) { 315 hinfo = rhashtable_walk_next(iter); 316 317 if (IS_ERR(hinfo)) { 318 if (PTR_ERR(hinfo) == -EAGAIN) 319 continue; 320 ret = PTR_ERR(hinfo); 321 goto done; 322 } else if (!hinfo) { 323 break; 324 } 325 326 ret = __seg6_genl_dumphmac_element(hinfo, 327 NETLINK_CB(cb->skb).portid, 328 cb->nlh->nlmsg_seq, 329 NLM_F_MULTI, 330 skb, SEG6_CMD_DUMPHMAC); 331 if (ret) 332 goto done; 333 } 334 335 ret = skb->len; 336 337 done: 338 rhashtable_walk_stop(iter); 339 return ret; 340 } 341 342 #else 343 344 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 345 { 346 return 0; 347 } 348 349 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 350 { 351 return 0; 352 } 353 354 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 355 { 356 return -ENOTSUPP; 357 } 358 359 #endif 360 361 static int __net_init seg6_net_init(struct net *net) 362 { 363 struct seg6_pernet_data *sdata; 364 365 sdata = kzalloc(sizeof(*sdata), GFP_KERNEL); 366 if (!sdata) 367 return -ENOMEM; 368 369 mutex_init(&sdata->lock); 370 371 sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL); 372 if (!sdata->tun_src) { 373 kfree(sdata); 374 return -ENOMEM; 375 } 376 377 net->ipv6.seg6_data = sdata; 378 379 #ifdef CONFIG_IPV6_SEG6_HMAC 380 seg6_hmac_net_init(net); 381 #endif 382 383 return 0; 384 } 385 386 static void __net_exit seg6_net_exit(struct net *net) 387 { 388 struct seg6_pernet_data *sdata = seg6_pernet(net); 389 390 #ifdef CONFIG_IPV6_SEG6_HMAC 391 seg6_hmac_net_exit(net); 392 #endif 393 394 kfree(sdata->tun_src); 395 kfree(sdata); 396 } 397 398 static struct pernet_operations ip6_segments_ops = { 399 .init = seg6_net_init, 400 .exit = seg6_net_exit, 401 }; 402 403 static const struct genl_ops seg6_genl_ops[] = { 404 { 405 .cmd = SEG6_CMD_SETHMAC, 406 .doit = seg6_genl_sethmac, 407 .policy = seg6_genl_policy, 408 .flags = GENL_ADMIN_PERM, 409 }, 410 { 411 .cmd = SEG6_CMD_DUMPHMAC, 412 .start = seg6_genl_dumphmac_start, 413 .dumpit = seg6_genl_dumphmac, 414 .done = seg6_genl_dumphmac_done, 415 .policy = seg6_genl_policy, 416 .flags = GENL_ADMIN_PERM, 417 }, 418 { 419 .cmd = SEG6_CMD_SET_TUNSRC, 420 .doit = seg6_genl_set_tunsrc, 421 .policy = seg6_genl_policy, 422 .flags = GENL_ADMIN_PERM, 423 }, 424 { 425 .cmd = SEG6_CMD_GET_TUNSRC, 426 .doit = seg6_genl_get_tunsrc, 427 .policy = seg6_genl_policy, 428 .flags = GENL_ADMIN_PERM, 429 }, 430 }; 431 432 static struct genl_family seg6_genl_family __ro_after_init = { 433 .hdrsize = 0, 434 .name = SEG6_GENL_NAME, 435 .version = SEG6_GENL_VERSION, 436 .maxattr = SEG6_ATTR_MAX, 437 .netnsok = true, 438 .parallel_ops = true, 439 .ops = seg6_genl_ops, 440 .n_ops = ARRAY_SIZE(seg6_genl_ops), 441 .module = THIS_MODULE, 442 }; 443 444 int __init seg6_init(void) 445 { 446 int err = -ENOMEM; 447 448 err = genl_register_family(&seg6_genl_family); 449 if (err) 450 goto out; 451 452 err = register_pernet_subsys(&ip6_segments_ops); 453 if (err) 454 goto out_unregister_genl; 455 456 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 457 err = seg6_iptunnel_init(); 458 if (err) 459 goto out_unregister_pernet; 460 #endif 461 462 #ifdef CONFIG_IPV6_SEG6_HMAC 463 err = seg6_hmac_init(); 464 if (err) 465 goto out_unregister_iptun; 466 #endif 467 468 pr_info("Segment Routing with IPv6\n"); 469 470 out: 471 return err; 472 #ifdef CONFIG_IPV6_SEG6_HMAC 473 out_unregister_iptun: 474 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 475 seg6_iptunnel_exit(); 476 #endif 477 #endif 478 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 479 out_unregister_pernet: 480 unregister_pernet_subsys(&ip6_segments_ops); 481 #endif 482 out_unregister_genl: 483 genl_unregister_family(&seg6_genl_family); 484 goto out; 485 } 486 487 void seg6_exit(void) 488 { 489 #ifdef CONFIG_IPV6_SEG6_HMAC 490 seg6_hmac_exit(); 491 #endif 492 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 493 seg6_iptunnel_exit(); 494 #endif 495 unregister_pernet_subsys(&ip6_segments_ops); 496 genl_unregister_family(&seg6_genl_family); 497 } 498