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 return genlmsg_reply(msg, info); 225 226 nla_put_failure: 227 rcu_read_unlock(); 228 free_msg: 229 nlmsg_free(msg); 230 return -ENOMEM; 231 } 232 233 #ifdef CONFIG_IPV6_SEG6_HMAC 234 235 static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo, 236 struct sk_buff *msg) 237 { 238 if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) || 239 nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) || 240 nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) || 241 nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id)) 242 return -1; 243 244 return 0; 245 } 246 247 static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo, 248 u32 portid, u32 seq, u32 flags, 249 struct sk_buff *skb, u8 cmd) 250 { 251 void *hdr; 252 253 hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd); 254 if (!hdr) 255 return -ENOMEM; 256 257 if (__seg6_hmac_fill_info(hinfo, skb) < 0) 258 goto nla_put_failure; 259 260 genlmsg_end(skb, hdr); 261 return 0; 262 263 nla_put_failure: 264 genlmsg_cancel(skb, hdr); 265 return -EMSGSIZE; 266 } 267 268 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 269 { 270 struct net *net = sock_net(cb->skb->sk); 271 struct seg6_pernet_data *sdata; 272 struct rhashtable_iter *iter; 273 274 sdata = seg6_pernet(net); 275 iter = (struct rhashtable_iter *)cb->args[0]; 276 277 if (!iter) { 278 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 279 if (!iter) 280 return -ENOMEM; 281 282 cb->args[0] = (long)iter; 283 } 284 285 rhashtable_walk_enter(&sdata->hmac_infos, iter); 286 287 return 0; 288 } 289 290 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 291 { 292 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; 293 294 rhashtable_walk_exit(iter); 295 296 kfree(iter); 297 298 return 0; 299 } 300 301 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 302 { 303 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0]; 304 struct seg6_hmac_info *hinfo; 305 int ret; 306 307 rhashtable_walk_start(iter); 308 309 for (;;) { 310 hinfo = rhashtable_walk_next(iter); 311 312 if (IS_ERR(hinfo)) { 313 if (PTR_ERR(hinfo) == -EAGAIN) 314 continue; 315 ret = PTR_ERR(hinfo); 316 goto done; 317 } else if (!hinfo) { 318 break; 319 } 320 321 ret = __seg6_genl_dumphmac_element(hinfo, 322 NETLINK_CB(cb->skb).portid, 323 cb->nlh->nlmsg_seq, 324 NLM_F_MULTI, 325 skb, SEG6_CMD_DUMPHMAC); 326 if (ret) 327 goto done; 328 } 329 330 ret = skb->len; 331 332 done: 333 rhashtable_walk_stop(iter); 334 return ret; 335 } 336 337 #else 338 339 static int seg6_genl_dumphmac_start(struct netlink_callback *cb) 340 { 341 return 0; 342 } 343 344 static int seg6_genl_dumphmac_done(struct netlink_callback *cb) 345 { 346 return 0; 347 } 348 349 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb) 350 { 351 return -ENOTSUPP; 352 } 353 354 #endif 355 356 static int __net_init seg6_net_init(struct net *net) 357 { 358 struct seg6_pernet_data *sdata; 359 360 sdata = kzalloc(sizeof(*sdata), GFP_KERNEL); 361 if (!sdata) 362 return -ENOMEM; 363 364 mutex_init(&sdata->lock); 365 366 sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL); 367 if (!sdata->tun_src) { 368 kfree(sdata); 369 return -ENOMEM; 370 } 371 372 net->ipv6.seg6_data = sdata; 373 374 #ifdef CONFIG_IPV6_SEG6_HMAC 375 seg6_hmac_net_init(net); 376 #endif 377 378 return 0; 379 } 380 381 static void __net_exit seg6_net_exit(struct net *net) 382 { 383 struct seg6_pernet_data *sdata = seg6_pernet(net); 384 385 #ifdef CONFIG_IPV6_SEG6_HMAC 386 seg6_hmac_net_exit(net); 387 #endif 388 389 kfree(sdata->tun_src); 390 kfree(sdata); 391 } 392 393 static struct pernet_operations ip6_segments_ops = { 394 .init = seg6_net_init, 395 .exit = seg6_net_exit, 396 }; 397 398 static const struct genl_ops seg6_genl_ops[] = { 399 { 400 .cmd = SEG6_CMD_SETHMAC, 401 .doit = seg6_genl_sethmac, 402 .policy = seg6_genl_policy, 403 .flags = GENL_ADMIN_PERM, 404 }, 405 { 406 .cmd = SEG6_CMD_DUMPHMAC, 407 .start = seg6_genl_dumphmac_start, 408 .dumpit = seg6_genl_dumphmac, 409 .done = seg6_genl_dumphmac_done, 410 .policy = seg6_genl_policy, 411 .flags = GENL_ADMIN_PERM, 412 }, 413 { 414 .cmd = SEG6_CMD_SET_TUNSRC, 415 .doit = seg6_genl_set_tunsrc, 416 .policy = seg6_genl_policy, 417 .flags = GENL_ADMIN_PERM, 418 }, 419 { 420 .cmd = SEG6_CMD_GET_TUNSRC, 421 .doit = seg6_genl_get_tunsrc, 422 .policy = seg6_genl_policy, 423 .flags = GENL_ADMIN_PERM, 424 }, 425 }; 426 427 static struct genl_family seg6_genl_family __ro_after_init = { 428 .hdrsize = 0, 429 .name = SEG6_GENL_NAME, 430 .version = SEG6_GENL_VERSION, 431 .maxattr = SEG6_ATTR_MAX, 432 .netnsok = true, 433 .parallel_ops = true, 434 .ops = seg6_genl_ops, 435 .n_ops = ARRAY_SIZE(seg6_genl_ops), 436 .module = THIS_MODULE, 437 }; 438 439 int __init seg6_init(void) 440 { 441 int err = -ENOMEM; 442 443 err = genl_register_family(&seg6_genl_family); 444 if (err) 445 goto out; 446 447 err = register_pernet_subsys(&ip6_segments_ops); 448 if (err) 449 goto out_unregister_genl; 450 451 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 452 err = seg6_iptunnel_init(); 453 if (err) 454 goto out_unregister_pernet; 455 456 err = seg6_local_init(); 457 if (err) 458 goto out_unregister_pernet; 459 #endif 460 461 #ifdef CONFIG_IPV6_SEG6_HMAC 462 err = seg6_hmac_init(); 463 if (err) 464 goto out_unregister_iptun; 465 #endif 466 467 pr_info("Segment Routing with IPv6\n"); 468 469 out: 470 return err; 471 #ifdef CONFIG_IPV6_SEG6_HMAC 472 out_unregister_iptun: 473 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL 474 seg6_local_exit(); 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