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 if (trailing < sizeof(*tlv)) 57 return false; 58 59 tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset); 60 tlv_len = sizeof(*tlv) + tlv->len; 61 62 trailing -= tlv_len; 63 if (trailing < 0) 64 return false; 65 66 tlv_offset += tlv_len; 67 } 68 69 return true; 70 } 71 72 static struct genl_family seg6_genl_family; 73 74 static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = { 75 [SEG6_ATTR_DST] = { .type = NLA_BINARY, 76 .len = sizeof(struct in6_addr) }, 77 [SEG6_ATTR_DSTLEN] = { .type = NLA_S32, }, 78 [SEG6_ATTR_HMACKEYID] = { .type = NLA_U32, }, 79 [SEG6_ATTR_SECRET] = { .type = NLA_BINARY, }, 80 [SEG6_ATTR_SECRETLEN] = { .type = NLA_U8, }, 81 [SEG6_ATTR_ALGID] = { .type = NLA_U8, }, 82 [SEG6_ATTR_HMACINFO] = { .type = NLA_NESTED, }, 83 }; 84 85 #ifdef CONFIG_IPV6_SEG6_HMAC 86 87 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info) 88 { 89 struct net *net = genl_info_net(info); 90 struct seg6_pernet_data *sdata; 91 struct seg6_hmac_info *hinfo; 92 u32 hmackeyid; 93 char *secret; 94 int err = 0; 95 u8 algid; 96 u8 slen; 97 98 sdata = seg6_pernet(net); 99 100 if (!info->attrs[SEG6_ATTR_HMACKEYID] || 101 !info->attrs[SEG6_ATTR_SECRETLEN] || 102 !info->attrs[SEG6_ATTR_ALGID]) 103 return -EINVAL; 104 105 hmackeyid = nla_get_u32(info->attrs[SEG6_ATTR_HMACKEYID]); 106 slen = nla_get_u8(info->attrs[SEG6_ATTR_SECRETLEN]); 107 algid = nla_get_u8(info->attrs[SEG6_ATTR_ALGID]); 108 109 if (hmackeyid == 0) 110 return -EINVAL; 111 112 if (slen > SEG6_HMAC_SECRET_LEN) 113 return -EINVAL; 114 115 mutex_lock(&sdata->lock); 116 hinfo = seg6_hmac_info_lookup(net, hmackeyid); 117 118 if (!slen) { 119 if (!hinfo) 120 err = -ENOENT; 121 122 err = seg6_hmac_info_del(net, hmackeyid); 123 124 goto out_unlock; 125 } 126 127 if (!info->attrs[SEG6_ATTR_SECRET]) { 128 err = -EINVAL; 129 goto out_unlock; 130 } 131 132 if (hinfo) { 133 err = seg6_hmac_info_del(net, hmackeyid); 134 if (err) 135 goto out_unlock; 136 } 137 138 secret = (char *)nla_data(info->attrs[SEG6_ATTR_SECRET]); 139 140 hinfo = kzalloc(sizeof(*hinfo), GFP_KERNEL); 141 if (!hinfo) { 142 err = -ENOMEM; 143 goto out_unlock; 144 } 145 146 memcpy(hinfo->secret, secret, slen); 147 hinfo->slen = slen; 148 hinfo->alg_id = algid; 149 hinfo->hmackeyid = hmackeyid; 150 151 err = seg6_hmac_info_add(net, hmackeyid, hinfo); 152 if (err) 153 kfree(hinfo); 154 155 out_unlock: 156 mutex_unlock(&sdata->lock); 157 return err; 158 } 159 160 #else 161 162 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info) 163 { 164 return -ENOTSUPP; 165 } 166 167 #endif 168 169 static int seg6_genl_set_tunsrc(struct sk_buff *skb, struct genl_info *info) 170 { 171 struct net *net = genl_info_net(info); 172 struct in6_addr *val, *t_old, *t_new; 173 struct seg6_pernet_data *sdata; 174 175 sdata = seg6_pernet(net); 176 177 if (!info->attrs[SEG6_ATTR_DST]) 178 return -EINVAL; 179 180 val = nla_data(info->attrs[SEG6_ATTR_DST]); 181 t_new = kmemdup(val, sizeof(*val), GFP_KERNEL); 182 if (!t_new) 183 return -ENOMEM; 184 185 mutex_lock(&sdata->lock); 186 187 t_old = sdata->tun_src; 188 rcu_assign_pointer(sdata->tun_src, t_new); 189 190 mutex_unlock(&sdata->lock); 191 192 synchronize_net(); 193 kfree(t_old); 194 195 return 0; 196 } 197 198 static int seg6_genl_get_tunsrc(struct sk_buff *skb, struct genl_info *info) 199 { 200 struct net *net = genl_info_net(info); 201 struct in6_addr *tun_src; 202 struct sk_buff *msg; 203 void *hdr; 204 205 msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 206 if (!msg) 207 return -ENOMEM; 208 209 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, 210 &seg6_genl_family, 0, SEG6_CMD_GET_TUNSRC); 211 if (!hdr) 212 goto free_msg; 213 214 rcu_read_lock(); 215 tun_src = rcu_dereference(seg6_pernet(net)->tun_src); 216 217 if (nla_put(msg, SEG6_ATTR_DST, sizeof(struct in6_addr), tun_src)) 218 goto nla_put_failure; 219 220 rcu_read_unlock(); 221 222 genlmsg_end(msg, hdr); 223 genlmsg_reply(msg, info); 224 225 return 0; 226 227 nla_put_failure: 228 rcu_read_unlock(); 229 genlmsg_cancel(msg, hdr); 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 ret = rhashtable_walk_start(iter); 310 if (ret && ret != -EAGAIN) 311 goto done; 312 313 for (;;) { 314 hinfo = rhashtable_walk_next(iter); 315 316 if (IS_ERR(hinfo)) { 317 if (PTR_ERR(hinfo) == -EAGAIN) 318 continue; 319 ret = PTR_ERR(hinfo); 320 goto done; 321 } else if (!hinfo) { 322 break; 323 } 324 325 ret = __seg6_genl_dumphmac_element(hinfo, 326 NETLINK_CB(cb->skb).portid, 327 cb->nlh->nlmsg_seq, 328 NLM_F_MULTI, 329 skb, SEG6_CMD_DUMPHMAC); 330 if (ret) 331 goto done; 332 } 333 334 ret = skb->len; 335 336 done: 337 rhashtable_walk_stop(iter); 338 return ret; 339 } 340 341 #else 342 343 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 344 { 345 return 0; 346 } 347 348 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 349 { 350 return 0; 351 } 352 353 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 354 { 355 return -ENOTSUPP; 356 } 357 358 #endif 359 360 static int __net_init seg6_net_init(struct net *net) 361 { 362 struct seg6_pernet_data *sdata; 363 364 sdata = kzalloc(sizeof(*sdata), GFP_KERNEL); 365 if (!sdata) 366 return -ENOMEM; 367 368 mutex_init(&sdata->lock); 369 370 sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL); 371 if (!sdata->tun_src) { 372 kfree(sdata); 373 return -ENOMEM; 374 } 375 376 net->ipv6.seg6_data = sdata; 377 378 #ifdef CONFIG_IPV6_SEG6_HMAC 379 seg6_hmac_net_init(net); 380 #endif 381 382 return 0; 383 } 384 385 static void __net_exit seg6_net_exit(struct net *net) 386 { 387 struct seg6_pernet_data *sdata = seg6_pernet(net); 388 389 #ifdef CONFIG_IPV6_SEG6_HMAC 390 seg6_hmac_net_exit(net); 391 #endif 392 393 kfree(sdata->tun_src); 394 kfree(sdata); 395 } 396 397 static struct pernet_operations ip6_segments_ops = { 398 .init = seg6_net_init, 399 .exit = seg6_net_exit, 400 }; 401 402 static const struct genl_ops seg6_genl_ops[] = { 403 { 404 .cmd = SEG6_CMD_SETHMAC, 405 .doit = seg6_genl_sethmac, 406 .policy = seg6_genl_policy, 407 .flags = GENL_ADMIN_PERM, 408 }, 409 { 410 .cmd = SEG6_CMD_DUMPHMAC, 411 .start = seg6_genl_dumphmac_start, 412 .dumpit = seg6_genl_dumphmac, 413 .done = seg6_genl_dumphmac_done, 414 .policy = seg6_genl_policy, 415 .flags = GENL_ADMIN_PERM, 416 }, 417 { 418 .cmd = SEG6_CMD_SET_TUNSRC, 419 .doit = seg6_genl_set_tunsrc, 420 .policy = seg6_genl_policy, 421 .flags = GENL_ADMIN_PERM, 422 }, 423 { 424 .cmd = SEG6_CMD_GET_TUNSRC, 425 .doit = seg6_genl_get_tunsrc, 426 .policy = seg6_genl_policy, 427 .flags = GENL_ADMIN_PERM, 428 }, 429 }; 430 431 static struct genl_family seg6_genl_family __ro_after_init = { 432 .hdrsize = 0, 433 .name = SEG6_GENL_NAME, 434 .version = SEG6_GENL_VERSION, 435 .maxattr = SEG6_ATTR_MAX, 436 .netnsok = true, 437 .parallel_ops = true, 438 .ops = seg6_genl_ops, 439 .n_ops = ARRAY_SIZE(seg6_genl_ops), 440 .module = THIS_MODULE, 441 }; 442 443 int __init seg6_init(void) 444 { 445 int err = -ENOMEM; 446 447 err = genl_register_family(&seg6_genl_family); 448 if (err) 449 goto out; 450 451 err = register_pernet_subsys(&ip6_segments_ops); 452 if (err) 453 goto out_unregister_genl; 454 455 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 456 err = seg6_iptunnel_init(); 457 if (err) 458 goto out_unregister_pernet; 459 460 err = seg6_local_init(); 461 if (err) 462 goto out_unregister_pernet; 463 #endif 464 465 #ifdef CONFIG_IPV6_SEG6_HMAC 466 err = seg6_hmac_init(); 467 if (err) 468 goto out_unregister_iptun; 469 #endif 470 471 pr_info("Segment Routing with IPv6\n"); 472 473 out: 474 return err; 475 #ifdef CONFIG_IPV6_SEG6_HMAC 476 out_unregister_iptun: 477 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 478 seg6_local_exit(); 479 seg6_iptunnel_exit(); 480 #endif 481 #endif 482 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 483 out_unregister_pernet: 484 unregister_pernet_subsys(&ip6_segments_ops); 485 #endif 486 out_unregister_genl: 487 genl_unregister_family(&seg6_genl_family); 488 goto out; 489 } 490 491 void seg6_exit(void) 492 { 493 #ifdef CONFIG_IPV6_SEG6_HMAC 494 seg6_hmac_exit(); 495 #endif 496 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 497 seg6_iptunnel_exit(); 498 #endif 499 unregister_pernet_subsys(&ip6_segments_ops); 500 genl_unregister_family(&seg6_genl_family); 501 } 502