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 free_msg: 230 nlmsg_free(msg); 231 return -ENOMEM; 232 } 233 234 #ifdef CONFIG_IPV6_SEG6_HMAC 235 236 static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo, 237 struct sk_buff *msg) 238 { 239 if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) || 240 nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) || 241 nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) || 242 nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id)) 243 return -1; 244 245 return 0; 246 } 247 248 static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo, 249 u32 portid, u32 seq, u32 flags, 250 struct sk_buff *skb, u8 cmd) 251 { 252 void *hdr; 253 254 hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd); 255 if (!hdr) 256 return -ENOMEM; 257 258 if (__seg6_hmac_fill_info(hinfo, skb) < 0) 259 goto nla_put_failure; 260 261 genlmsg_end(skb, hdr); 262 return 0; 263 264 nla_put_failure: 265 genlmsg_cancel(skb, hdr); 266 return -EMSGSIZE; 267 } 268 269 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 270 { 271 struct net *net = sock_net(cb->skb->sk); 272 struct seg6_pernet_data *sdata; 273 struct rhashtable_iter *iter; 274 275 sdata = seg6_pernet(net); 276 iter = (struct rhashtable_iter *)cb->args[0]; 277 278 if (!iter) { 279 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 280 if (!iter) 281 return -ENOMEM; 282 283 cb->args[0] = (long)iter; 284 } 285 286 rhashtable_walk_enter(&sdata->hmac_infos, iter); 287 288 return 0; 289 } 290 291 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 292 { 293 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; 294 295 rhashtable_walk_exit(iter); 296 297 kfree(iter); 298 299 return 0; 300 } 301 302 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 303 { 304 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; 305 struct seg6_hmac_info *hinfo; 306 int ret; 307 308 rhashtable_walk_start(iter); 309 310 for (;;) { 311 hinfo = rhashtable_walk_next(iter); 312 313 if (IS_ERR(hinfo)) { 314 if (PTR_ERR(hinfo) == -EAGAIN) 315 continue; 316 ret = PTR_ERR(hinfo); 317 goto done; 318 } else if (!hinfo) { 319 break; 320 } 321 322 ret = __seg6_genl_dumphmac_element(hinfo, 323 NETLINK_CB(cb->skb).portid, 324 cb->nlh->nlmsg_seq, 325 NLM_F_MULTI, 326 skb, SEG6_CMD_DUMPHMAC); 327 if (ret) 328 goto done; 329 } 330 331 ret = skb->len; 332 333 done: 334 rhashtable_walk_stop(iter); 335 return ret; 336 } 337 338 #else 339 340 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 341 { 342 return 0; 343 } 344 345 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 346 { 347 return 0; 348 } 349 350 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 351 { 352 return -ENOTSUPP; 353 } 354 355 #endif 356 357 static int __net_init seg6_net_init(struct net *net) 358 { 359 struct seg6_pernet_data *sdata; 360 361 sdata = kzalloc(sizeof(*sdata), GFP_KERNEL); 362 if (!sdata) 363 return -ENOMEM; 364 365 mutex_init(&sdata->lock); 366 367 sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL); 368 if (!sdata->tun_src) { 369 kfree(sdata); 370 return -ENOMEM; 371 } 372 373 net->ipv6.seg6_data = sdata; 374 375 #ifdef CONFIG_IPV6_SEG6_HMAC 376 seg6_hmac_net_init(net); 377 #endif 378 379 return 0; 380 } 381 382 static void __net_exit seg6_net_exit(struct net *net) 383 { 384 struct seg6_pernet_data *sdata = seg6_pernet(net); 385 386 #ifdef CONFIG_IPV6_SEG6_HMAC 387 seg6_hmac_net_exit(net); 388 #endif 389 390 kfree(sdata->tun_src); 391 kfree(sdata); 392 } 393 394 static struct pernet_operations ip6_segments_ops = { 395 .init = seg6_net_init, 396 .exit = seg6_net_exit, 397 }; 398 399 static const struct genl_ops seg6_genl_ops[] = { 400 { 401 .cmd = SEG6_CMD_SETHMAC, 402 .doit = seg6_genl_sethmac, 403 .policy = seg6_genl_policy, 404 .flags = GENL_ADMIN_PERM, 405 }, 406 { 407 .cmd = SEG6_CMD_DUMPHMAC, 408 .start = seg6_genl_dumphmac_start, 409 .dumpit = seg6_genl_dumphmac, 410 .done = seg6_genl_dumphmac_done, 411 .policy = seg6_genl_policy, 412 .flags = GENL_ADMIN_PERM, 413 }, 414 { 415 .cmd = SEG6_CMD_SET_TUNSRC, 416 .doit = seg6_genl_set_tunsrc, 417 .policy = seg6_genl_policy, 418 .flags = GENL_ADMIN_PERM, 419 }, 420 { 421 .cmd = SEG6_CMD_GET_TUNSRC, 422 .doit = seg6_genl_get_tunsrc, 423 .policy = seg6_genl_policy, 424 .flags = GENL_ADMIN_PERM, 425 }, 426 }; 427 428 static struct genl_family seg6_genl_family __ro_after_init = { 429 .hdrsize = 0, 430 .name = SEG6_GENL_NAME, 431 .version = SEG6_GENL_VERSION, 432 .maxattr = SEG6_ATTR_MAX, 433 .netnsok = true, 434 .parallel_ops = true, 435 .ops = seg6_genl_ops, 436 .n_ops = ARRAY_SIZE(seg6_genl_ops), 437 .module = THIS_MODULE, 438 }; 439 440 int __init seg6_init(void) 441 { 442 int err = -ENOMEM; 443 444 err = genl_register_family(&seg6_genl_family); 445 if (err) 446 goto out; 447 448 err = register_pernet_subsys(&ip6_segments_ops); 449 if (err) 450 goto out_unregister_genl; 451 452 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 453 err = seg6_iptunnel_init(); 454 if (err) 455 goto out_unregister_pernet; 456 457 err = seg6_local_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_local_exit(); 476 seg6_iptunnel_exit(); 477 #endif 478 #endif 479 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 480 out_unregister_pernet: 481 unregister_pernet_subsys(&ip6_segments_ops); 482 #endif 483 out_unregister_genl: 484 genl_unregister_family(&seg6_genl_family); 485 goto out; 486 } 487 488 void seg6_exit(void) 489 { 490 #ifdef CONFIG_IPV6_SEG6_HMAC 491 seg6_hmac_exit(); 492 #endif 493 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 494 seg6_iptunnel_exit(); 495 #endif 496 unregister_pernet_subsys(&ip6_segments_ops); 497 genl_unregister_family(&seg6_genl_family); 498 } 499