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 #include <linux/rhashtable.h> 21 22 #include <net/ipv6.h> 23 #include <net/protocol.h> 24 25 #include <net/seg6.h> 26 #include <net/genetlink.h> 27 #include <linux/seg6.h> 28 #include <linux/seg6_genl.h> 29 #ifdef CONFIG_IPV6_SEG6_HMAC 30 #include <net/seg6_hmac.h> 31 #endif 32 33 bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len) 34 { 35 int trailing; 36 unsigned int tlv_offset; 37 38 if (srh->type != IPV6_SRCRT_TYPE_4) 39 return false; 40 41 if (((srh->hdrlen + 1) << 3) != len) 42 return false; 43 44 if (srh->segments_left > srh->first_segment) 45 return false; 46 47 tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4); 48 49 trailing = len - tlv_offset; 50 if (trailing < 0) 51 return false; 52 53 while (trailing) { 54 struct sr6_tlv *tlv; 55 unsigned int tlv_len; 56 57 if (trailing < sizeof(*tlv)) 58 return false; 59 60 tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset); 61 tlv_len = sizeof(*tlv) + tlv->len; 62 63 trailing -= tlv_len; 64 if (trailing < 0) 65 return false; 66 67 tlv_offset += tlv_len; 68 } 69 70 return true; 71 } 72 73 static struct genl_family seg6_genl_family; 74 75 static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = { 76 [SEG6_ATTR_DST] = { .type = NLA_BINARY, 77 .len = sizeof(struct in6_addr) }, 78 [SEG6_ATTR_DSTLEN] = { .type = NLA_S32, }, 79 [SEG6_ATTR_HMACKEYID] = { .type = NLA_U32, }, 80 [SEG6_ATTR_SECRET] = { .type = NLA_BINARY, }, 81 [SEG6_ATTR_SECRETLEN] = { .type = NLA_U8, }, 82 [SEG6_ATTR_ALGID] = { .type = NLA_U8, }, 83 [SEG6_ATTR_HMACINFO] = { .type = NLA_NESTED, }, 84 }; 85 86 #ifdef CONFIG_IPV6_SEG6_HMAC 87 88 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info) 89 { 90 struct net *net = genl_info_net(info); 91 struct seg6_pernet_data *sdata; 92 struct seg6_hmac_info *hinfo; 93 u32 hmackeyid; 94 char *secret; 95 int err = 0; 96 u8 algid; 97 u8 slen; 98 99 sdata = seg6_pernet(net); 100 101 if (!info->attrs[SEG6_ATTR_HMACKEYID] || 102 !info->attrs[SEG6_ATTR_SECRETLEN] || 103 !info->attrs[SEG6_ATTR_ALGID]) 104 return -EINVAL; 105 106 hmackeyid = nla_get_u32(info->attrs[SEG6_ATTR_HMACKEYID]); 107 slen = nla_get_u8(info->attrs[SEG6_ATTR_SECRETLEN]); 108 algid = nla_get_u8(info->attrs[SEG6_ATTR_ALGID]); 109 110 if (hmackeyid == 0) 111 return -EINVAL; 112 113 if (slen > SEG6_HMAC_SECRET_LEN) 114 return -EINVAL; 115 116 mutex_lock(&sdata->lock); 117 hinfo = seg6_hmac_info_lookup(net, hmackeyid); 118 119 if (!slen) { 120 if (!hinfo) 121 err = -ENOENT; 122 123 err = seg6_hmac_info_del(net, hmackeyid); 124 125 goto out_unlock; 126 } 127 128 if (!info->attrs[SEG6_ATTR_SECRET]) { 129 err = -EINVAL; 130 goto out_unlock; 131 } 132 133 if (hinfo) { 134 err = seg6_hmac_info_del(net, hmackeyid); 135 if (err) 136 goto out_unlock; 137 } 138 139 secret = (char *)nla_data(info->attrs[SEG6_ATTR_SECRET]); 140 141 hinfo = kzalloc(sizeof(*hinfo), GFP_KERNEL); 142 if (!hinfo) { 143 err = -ENOMEM; 144 goto out_unlock; 145 } 146 147 memcpy(hinfo->secret, secret, slen); 148 hinfo->slen = slen; 149 hinfo->alg_id = algid; 150 hinfo->hmackeyid = hmackeyid; 151 152 err = seg6_hmac_info_add(net, hmackeyid, hinfo); 153 if (err) 154 kfree(hinfo); 155 156 out_unlock: 157 mutex_unlock(&sdata->lock); 158 return err; 159 } 160 161 #else 162 163 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info) 164 { 165 return -ENOTSUPP; 166 } 167 168 #endif 169 170 static int seg6_genl_set_tunsrc(struct sk_buff *skb, struct genl_info *info) 171 { 172 struct net *net = genl_info_net(info); 173 struct in6_addr *val, *t_old, *t_new; 174 struct seg6_pernet_data *sdata; 175 176 sdata = seg6_pernet(net); 177 178 if (!info->attrs[SEG6_ATTR_DST]) 179 return -EINVAL; 180 181 val = nla_data(info->attrs[SEG6_ATTR_DST]); 182 t_new = kmemdup(val, sizeof(*val), GFP_KERNEL); 183 if (!t_new) 184 return -ENOMEM; 185 186 mutex_lock(&sdata->lock); 187 188 t_old = sdata->tun_src; 189 rcu_assign_pointer(sdata->tun_src, t_new); 190 191 mutex_unlock(&sdata->lock); 192 193 synchronize_net(); 194 kfree(t_old); 195 196 return 0; 197 } 198 199 static int seg6_genl_get_tunsrc(struct sk_buff *skb, struct genl_info *info) 200 { 201 struct net *net = genl_info_net(info); 202 struct in6_addr *tun_src; 203 struct sk_buff *msg; 204 void *hdr; 205 206 msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 207 if (!msg) 208 return -ENOMEM; 209 210 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, 211 &seg6_genl_family, 0, SEG6_CMD_GET_TUNSRC); 212 if (!hdr) 213 goto free_msg; 214 215 rcu_read_lock(); 216 tun_src = rcu_dereference(seg6_pernet(net)->tun_src); 217 218 if (nla_put(msg, SEG6_ATTR_DST, sizeof(struct in6_addr), tun_src)) 219 goto nla_put_failure; 220 221 rcu_read_unlock(); 222 223 genlmsg_end(msg, hdr); 224 genlmsg_reply(msg, info); 225 226 return 0; 227 228 nla_put_failure: 229 rcu_read_unlock(); 230 free_msg: 231 nlmsg_free(msg); 232 return -ENOMEM; 233 } 234 235 #ifdef CONFIG_IPV6_SEG6_HMAC 236 237 static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo, 238 struct sk_buff *msg) 239 { 240 if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) || 241 nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) || 242 nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) || 243 nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id)) 244 return -1; 245 246 return 0; 247 } 248 249 static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo, 250 u32 portid, u32 seq, u32 flags, 251 struct sk_buff *skb, u8 cmd) 252 { 253 void *hdr; 254 255 hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd); 256 if (!hdr) 257 return -ENOMEM; 258 259 if (__seg6_hmac_fill_info(hinfo, skb) < 0) 260 goto nla_put_failure; 261 262 genlmsg_end(skb, hdr); 263 return 0; 264 265 nla_put_failure: 266 genlmsg_cancel(skb, hdr); 267 return -EMSGSIZE; 268 } 269 270 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 271 { 272 struct net *net = sock_net(cb->skb->sk); 273 struct seg6_pernet_data *sdata; 274 struct rhashtable_iter *iter; 275 276 sdata = seg6_pernet(net); 277 iter = (struct rhashtable_iter *)cb->args[0]; 278 279 if (!iter) { 280 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 281 if (!iter) 282 return -ENOMEM; 283 284 cb->args[0] = (long)iter; 285 } 286 287 rhashtable_walk_enter(&sdata->hmac_infos, iter); 288 289 return 0; 290 } 291 292 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 293 { 294 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; 295 296 rhashtable_walk_exit(iter); 297 298 kfree(iter); 299 300 return 0; 301 } 302 303 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 304 { 305 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; 306 struct seg6_hmac_info *hinfo; 307 int ret; 308 309 rhashtable_walk_start(iter); 310 311 for (;;) { 312 hinfo = rhashtable_walk_next(iter); 313 314 if (IS_ERR(hinfo)) { 315 if (PTR_ERR(hinfo) == -EAGAIN) 316 continue; 317 ret = PTR_ERR(hinfo); 318 goto done; 319 } else if (!hinfo) { 320 break; 321 } 322 323 ret = __seg6_genl_dumphmac_element(hinfo, 324 NETLINK_CB(cb->skb).portid, 325 cb->nlh->nlmsg_seq, 326 NLM_F_MULTI, 327 skb, SEG6_CMD_DUMPHMAC); 328 if (ret) 329 goto done; 330 } 331 332 ret = skb->len; 333 334 done: 335 rhashtable_walk_stop(iter); 336 return ret; 337 } 338 339 #else 340 341 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 342 { 343 return 0; 344 } 345 346 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 347 { 348 return 0; 349 } 350 351 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 352 { 353 return -ENOTSUPP; 354 } 355 356 #endif 357 358 static int __net_init seg6_net_init(struct net *net) 359 { 360 struct seg6_pernet_data *sdata; 361 362 sdata = kzalloc(sizeof(*sdata), GFP_KERNEL); 363 if (!sdata) 364 return -ENOMEM; 365 366 mutex_init(&sdata->lock); 367 368 sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL); 369 if (!sdata->tun_src) { 370 kfree(sdata); 371 return -ENOMEM; 372 } 373 374 net->ipv6.seg6_data = sdata; 375 376 #ifdef CONFIG_IPV6_SEG6_HMAC 377 seg6_hmac_net_init(net); 378 #endif 379 380 return 0; 381 } 382 383 static void __net_exit seg6_net_exit(struct net *net) 384 { 385 struct seg6_pernet_data *sdata = seg6_pernet(net); 386 387 #ifdef CONFIG_IPV6_SEG6_HMAC 388 seg6_hmac_net_exit(net); 389 #endif 390 391 kfree(sdata->tun_src); 392 kfree(sdata); 393 } 394 395 static struct pernet_operations ip6_segments_ops = { 396 .init = seg6_net_init, 397 .exit = seg6_net_exit, 398 }; 399 400 static const struct genl_ops seg6_genl_ops[] = { 401 { 402 .cmd = SEG6_CMD_SETHMAC, 403 .doit = seg6_genl_sethmac, 404 .policy = seg6_genl_policy, 405 .flags = GENL_ADMIN_PERM, 406 }, 407 { 408 .cmd = SEG6_CMD_DUMPHMAC, 409 .start = seg6_genl_dumphmac_start, 410 .dumpit = seg6_genl_dumphmac, 411 .done = seg6_genl_dumphmac_done, 412 .policy = seg6_genl_policy, 413 .flags = GENL_ADMIN_PERM, 414 }, 415 { 416 .cmd = SEG6_CMD_SET_TUNSRC, 417 .doit = seg6_genl_set_tunsrc, 418 .policy = seg6_genl_policy, 419 .flags = GENL_ADMIN_PERM, 420 }, 421 { 422 .cmd = SEG6_CMD_GET_TUNSRC, 423 .doit = seg6_genl_get_tunsrc, 424 .policy = seg6_genl_policy, 425 .flags = GENL_ADMIN_PERM, 426 }, 427 }; 428 429 static struct genl_family seg6_genl_family __ro_after_init = { 430 .hdrsize = 0, 431 .name = SEG6_GENL_NAME, 432 .version = SEG6_GENL_VERSION, 433 .maxattr = SEG6_ATTR_MAX, 434 .netnsok = true, 435 .parallel_ops = true, 436 .ops = seg6_genl_ops, 437 .n_ops = ARRAY_SIZE(seg6_genl_ops), 438 .module = THIS_MODULE, 439 }; 440 441 int __init seg6_init(void) 442 { 443 int err = -ENOMEM; 444 445 err = genl_register_family(&seg6_genl_family); 446 if (err) 447 goto out; 448 449 err = register_pernet_subsys(&ip6_segments_ops); 450 if (err) 451 goto out_unregister_genl; 452 453 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 454 err = seg6_iptunnel_init(); 455 if (err) 456 goto out_unregister_pernet; 457 458 err = seg6_local_init(); 459 if (err) 460 goto out_unregister_pernet; 461 #endif 462 463 #ifdef CONFIG_IPV6_SEG6_HMAC 464 err = seg6_hmac_init(); 465 if (err) 466 goto out_unregister_iptun; 467 #endif 468 469 pr_info("Segment Routing with IPv6\n"); 470 471 out: 472 return err; 473 #ifdef CONFIG_IPV6_SEG6_HMAC 474 out_unregister_iptun: 475 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 476 seg6_local_exit(); 477 seg6_iptunnel_exit(); 478 #endif 479 #endif 480 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 481 out_unregister_pernet: 482 unregister_pernet_subsys(&ip6_segments_ops); 483 #endif 484 out_unregister_genl: 485 genl_unregister_family(&seg6_genl_family); 486 goto out; 487 } 488 489 void seg6_exit(void) 490 { 491 #ifdef CONFIG_IPV6_SEG6_HMAC 492 seg6_hmac_exit(); 493 #endif 494 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 495 seg6_iptunnel_exit(); 496 #endif 497 unregister_pernet_subsys(&ip6_segments_ops); 498 genl_unregister_family(&seg6_genl_family); 499 } 500