1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * SR-IPv6 implementation 4 * 5 * Authors: 6 * David Lebrun <david.lebrun@uclouvain.be> 7 * eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com> 8 */ 9 10 #include <linux/filter.h> 11 #include <linux/types.h> 12 #include <linux/skbuff.h> 13 #include <linux/net.h> 14 #include <linux/module.h> 15 #include <net/ip.h> 16 #include <net/lwtunnel.h> 17 #include <net/netevent.h> 18 #include <net/netns/generic.h> 19 #include <net/ip6_fib.h> 20 #include <net/route.h> 21 #include <net/seg6.h> 22 #include <linux/seg6.h> 23 #include <linux/seg6_local.h> 24 #include <net/addrconf.h> 25 #include <net/ip6_route.h> 26 #include <net/dst_cache.h> 27 #include <net/ip_tunnels.h> 28 #ifdef CONFIG_IPV6_SEG6_HMAC 29 #include <net/seg6_hmac.h> 30 #endif 31 #include <net/seg6_local.h> 32 #include <linux/etherdevice.h> 33 #include <linux/bpf.h> 34 #include <linux/netfilter.h> 35 36 #define SEG6_F_ATTR(i) BIT(i) 37 38 struct seg6_local_lwt; 39 40 /* callbacks used for customizing the creation and destruction of a behavior */ 41 struct seg6_local_lwtunnel_ops { 42 int (*build_state)(struct seg6_local_lwt *slwt, const void *cfg, 43 struct netlink_ext_ack *extack); 44 void (*destroy_state)(struct seg6_local_lwt *slwt); 45 }; 46 47 struct seg6_action_desc { 48 int action; 49 unsigned long attrs; 50 51 /* The optattrs field is used for specifying all the optional 52 * attributes supported by a specific behavior. 53 * It means that if one of these attributes is not provided in the 54 * netlink message during the behavior creation, no errors will be 55 * returned to the userspace. 56 * 57 * Each attribute can be only of two types (mutually exclusive): 58 * 1) required or 2) optional. 59 * Every user MUST obey to this rule! If you set an attribute as 60 * required the same attribute CANNOT be set as optional and vice 61 * versa. 62 */ 63 unsigned long optattrs; 64 65 int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt); 66 int static_headroom; 67 68 struct seg6_local_lwtunnel_ops slwt_ops; 69 }; 70 71 struct bpf_lwt_prog { 72 struct bpf_prog *prog; 73 char *name; 74 }; 75 76 /* default length values (expressed in bits) for both Locator-Block and 77 * Locator-Node Function. 78 * 79 * Both SEG6_LOCAL_LCBLOCK_DBITS and SEG6_LOCAL_LCNODE_FN_DBITS *must* be: 80 * i) greater than 0; 81 * ii) evenly divisible by 8. In other terms, the lengths of the 82 * Locator-Block and Locator-Node Function must be byte-aligned (we can 83 * relax this constraint in the future if really needed). 84 * 85 * Moreover, a third condition must hold: 86 * iii) SEG6_LOCAL_LCBLOCK_DBITS + SEG6_LOCAL_LCNODE_FN_DBITS <= 128. 87 * 88 * The correctness of SEG6_LOCAL_LCBLOCK_DBITS and SEG6_LOCAL_LCNODE_FN_DBITS 89 * values are checked during the kernel compilation. If the compilation stops, 90 * check the value of these parameters to see if they meet conditions (i), (ii) 91 * and (iii). 92 */ 93 #define SEG6_LOCAL_LCBLOCK_DBITS 32 94 #define SEG6_LOCAL_LCNODE_FN_DBITS 16 95 96 /* The following next_csid_chk_{cntr,lcblock,lcblock_fn}_bits macros can be 97 * used directly to check whether the lengths (in bits) of Locator-Block and 98 * Locator-Node Function are valid according to (i), (ii), (iii). 99 */ 100 #define next_csid_chk_cntr_bits(blen, flen) \ 101 ((blen) + (flen) > 128) 102 103 #define next_csid_chk_lcblock_bits(blen) \ 104 ({ \ 105 typeof(blen) __tmp = blen; \ 106 (!__tmp || __tmp > 120 || (__tmp & 0x07)); \ 107 }) 108 109 #define next_csid_chk_lcnode_fn_bits(flen) \ 110 next_csid_chk_lcblock_bits(flen) 111 112 /* Supported Flavor operations are reported in this bitmask */ 113 #define SEG6_LOCAL_FLV_SUPP_OPS (BIT(SEG6_LOCAL_FLV_OP_NEXT_CSID)) 114 115 struct seg6_flavors_info { 116 /* Flavor operations */ 117 __u32 flv_ops; 118 119 /* Locator-Block length, expressed in bits */ 120 __u8 lcblock_bits; 121 /* Locator-Node Function length, expressed in bits*/ 122 __u8 lcnode_func_bits; 123 }; 124 125 enum seg6_end_dt_mode { 126 DT_INVALID_MODE = -EINVAL, 127 DT_LEGACY_MODE = 0, 128 DT_VRF_MODE = 1, 129 }; 130 131 struct seg6_end_dt_info { 132 enum seg6_end_dt_mode mode; 133 134 struct net *net; 135 /* VRF device associated to the routing table used by the SRv6 136 * End.DT4/DT6 behavior for routing IPv4/IPv6 packets. 137 */ 138 int vrf_ifindex; 139 int vrf_table; 140 141 /* tunneled packet family (IPv4 or IPv6). 142 * Protocol and header length are inferred from family. 143 */ 144 u16 family; 145 }; 146 147 struct pcpu_seg6_local_counters { 148 u64_stats_t packets; 149 u64_stats_t bytes; 150 u64_stats_t errors; 151 152 struct u64_stats_sync syncp; 153 }; 154 155 /* This struct groups all the SRv6 Behavior counters supported so far. 156 * 157 * put_nla_counters() makes use of this data structure to collect all counter 158 * values after the per-CPU counter evaluation has been performed. 159 * Finally, each counter value (in seg6_local_counters) is stored in the 160 * corresponding netlink attribute and sent to user space. 161 * 162 * NB: we don't want to expose this structure to user space! 163 */ 164 struct seg6_local_counters { 165 __u64 packets; 166 __u64 bytes; 167 __u64 errors; 168 }; 169 170 #define seg6_local_alloc_pcpu_counters(__gfp) \ 171 __netdev_alloc_pcpu_stats(struct pcpu_seg6_local_counters, \ 172 ((__gfp) | __GFP_ZERO)) 173 174 #define SEG6_F_LOCAL_COUNTERS SEG6_F_ATTR(SEG6_LOCAL_COUNTERS) 175 176 struct seg6_local_lwt { 177 int action; 178 struct ipv6_sr_hdr *srh; 179 int table; 180 struct in_addr nh4; 181 struct in6_addr nh6; 182 int iif; 183 int oif; 184 struct bpf_lwt_prog bpf; 185 #ifdef CONFIG_NET_L3_MASTER_DEV 186 struct seg6_end_dt_info dt_info; 187 #endif 188 struct seg6_flavors_info flv_info; 189 190 struct pcpu_seg6_local_counters __percpu *pcpu_counters; 191 192 int headroom; 193 struct seg6_action_desc *desc; 194 /* unlike the required attrs, we have to track the optional attributes 195 * that have been effectively parsed. 196 */ 197 unsigned long parsed_optattrs; 198 }; 199 200 static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt) 201 { 202 return (struct seg6_local_lwt *)lwt->data; 203 } 204 205 static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb) 206 { 207 struct ipv6_sr_hdr *srh; 208 209 srh = seg6_get_srh(skb, IP6_FH_F_SKIP_RH); 210 if (!srh) 211 return NULL; 212 213 #ifdef CONFIG_IPV6_SEG6_HMAC 214 if (!seg6_hmac_validate_skb(skb)) 215 return NULL; 216 #endif 217 218 return srh; 219 } 220 221 static bool decap_and_validate(struct sk_buff *skb, int proto) 222 { 223 struct ipv6_sr_hdr *srh; 224 unsigned int off = 0; 225 226 srh = seg6_get_srh(skb, 0); 227 if (srh && srh->segments_left > 0) 228 return false; 229 230 #ifdef CONFIG_IPV6_SEG6_HMAC 231 if (srh && !seg6_hmac_validate_skb(skb)) 232 return false; 233 #endif 234 235 if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0) 236 return false; 237 238 if (!pskb_pull(skb, off)) 239 return false; 240 241 skb_postpull_rcsum(skb, skb_network_header(skb), off); 242 243 skb_reset_network_header(skb); 244 skb_reset_transport_header(skb); 245 if (iptunnel_pull_offloads(skb)) 246 return false; 247 248 return true; 249 } 250 251 static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr) 252 { 253 struct in6_addr *addr; 254 255 srh->segments_left--; 256 addr = srh->segments + srh->segments_left; 257 *daddr = *addr; 258 } 259 260 static int 261 seg6_lookup_any_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, 262 u32 tbl_id, bool local_delivery) 263 { 264 struct net *net = dev_net(skb->dev); 265 struct ipv6hdr *hdr = ipv6_hdr(skb); 266 int flags = RT6_LOOKUP_F_HAS_SADDR; 267 struct dst_entry *dst = NULL; 268 struct rt6_info *rt; 269 struct flowi6 fl6; 270 int dev_flags = 0; 271 272 memset(&fl6, 0, sizeof(fl6)); 273 fl6.flowi6_iif = skb->dev->ifindex; 274 fl6.daddr = nhaddr ? *nhaddr : hdr->daddr; 275 fl6.saddr = hdr->saddr; 276 fl6.flowlabel = ip6_flowinfo(hdr); 277 fl6.flowi6_mark = skb->mark; 278 fl6.flowi6_proto = hdr->nexthdr; 279 280 if (nhaddr) 281 fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH; 282 283 if (!tbl_id) { 284 dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags); 285 } else { 286 struct fib6_table *table; 287 288 table = fib6_get_table(net, tbl_id); 289 if (!table) 290 goto out; 291 292 rt = ip6_pol_route(net, table, 0, &fl6, skb, flags); 293 dst = &rt->dst; 294 } 295 296 /* we want to discard traffic destined for local packet processing, 297 * if @local_delivery is set to false. 298 */ 299 if (!local_delivery) 300 dev_flags |= IFF_LOOPBACK; 301 302 if (dst && (dst->dev->flags & dev_flags) && !dst->error) { 303 dst_release(dst); 304 dst = NULL; 305 } 306 307 out: 308 if (!dst) { 309 rt = net->ipv6.ip6_blk_hole_entry; 310 dst = &rt->dst; 311 dst_hold(dst); 312 } 313 314 skb_dst_drop(skb); 315 skb_dst_set(skb, dst); 316 return dst->error; 317 } 318 319 int seg6_lookup_nexthop(struct sk_buff *skb, 320 struct in6_addr *nhaddr, u32 tbl_id) 321 { 322 return seg6_lookup_any_nexthop(skb, nhaddr, tbl_id, false); 323 } 324 325 static __u8 seg6_flv_lcblock_octects(const struct seg6_flavors_info *finfo) 326 { 327 return finfo->lcblock_bits >> 3; 328 } 329 330 static __u8 seg6_flv_lcnode_func_octects(const struct seg6_flavors_info *finfo) 331 { 332 return finfo->lcnode_func_bits >> 3; 333 } 334 335 static bool seg6_next_csid_is_arg_zero(const struct in6_addr *addr, 336 const struct seg6_flavors_info *finfo) 337 { 338 __u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo); 339 __u8 blk_octects = seg6_flv_lcblock_octects(finfo); 340 __u8 arg_octects; 341 int i; 342 343 arg_octects = 16 - blk_octects - fnc_octects; 344 for (i = 0; i < arg_octects; ++i) { 345 if (addr->s6_addr[blk_octects + fnc_octects + i] != 0x00) 346 return false; 347 } 348 349 return true; 350 } 351 352 /* assume that DA.Argument length > 0 */ 353 static void seg6_next_csid_advance_arg(struct in6_addr *addr, 354 const struct seg6_flavors_info *finfo) 355 { 356 __u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo); 357 __u8 blk_octects = seg6_flv_lcblock_octects(finfo); 358 359 /* advance DA.Argument */ 360 memmove(&addr->s6_addr[blk_octects], 361 &addr->s6_addr[blk_octects + fnc_octects], 362 16 - blk_octects - fnc_octects); 363 364 memset(&addr->s6_addr[16 - fnc_octects], 0x00, fnc_octects); 365 } 366 367 static int input_action_end_core(struct sk_buff *skb, 368 struct seg6_local_lwt *slwt) 369 { 370 struct ipv6_sr_hdr *srh; 371 372 srh = get_and_validate_srh(skb); 373 if (!srh) 374 goto drop; 375 376 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 377 378 seg6_lookup_nexthop(skb, NULL, 0); 379 380 return dst_input(skb); 381 382 drop: 383 kfree_skb(skb); 384 return -EINVAL; 385 } 386 387 static int end_next_csid_core(struct sk_buff *skb, struct seg6_local_lwt *slwt) 388 { 389 const struct seg6_flavors_info *finfo = &slwt->flv_info; 390 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 391 392 if (seg6_next_csid_is_arg_zero(daddr, finfo)) 393 return input_action_end_core(skb, slwt); 394 395 /* update DA */ 396 seg6_next_csid_advance_arg(daddr, finfo); 397 398 seg6_lookup_nexthop(skb, NULL, 0); 399 400 return dst_input(skb); 401 } 402 403 static bool seg6_next_csid_enabled(__u32 fops) 404 { 405 return fops & BIT(SEG6_LOCAL_FLV_OP_NEXT_CSID); 406 } 407 408 /* regular endpoint function */ 409 static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt) 410 { 411 const struct seg6_flavors_info *finfo = &slwt->flv_info; 412 413 if (seg6_next_csid_enabled(finfo->flv_ops)) 414 return end_next_csid_core(skb, slwt); 415 416 return input_action_end_core(skb, slwt); 417 } 418 419 /* regular endpoint, and forward to specified nexthop */ 420 static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt) 421 { 422 struct ipv6_sr_hdr *srh; 423 424 srh = get_and_validate_srh(skb); 425 if (!srh) 426 goto drop; 427 428 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 429 430 seg6_lookup_nexthop(skb, &slwt->nh6, 0); 431 432 return dst_input(skb); 433 434 drop: 435 kfree_skb(skb); 436 return -EINVAL; 437 } 438 439 static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt) 440 { 441 struct ipv6_sr_hdr *srh; 442 443 srh = get_and_validate_srh(skb); 444 if (!srh) 445 goto drop; 446 447 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 448 449 seg6_lookup_nexthop(skb, NULL, slwt->table); 450 451 return dst_input(skb); 452 453 drop: 454 kfree_skb(skb); 455 return -EINVAL; 456 } 457 458 /* decapsulate and forward inner L2 frame on specified interface */ 459 static int input_action_end_dx2(struct sk_buff *skb, 460 struct seg6_local_lwt *slwt) 461 { 462 struct net *net = dev_net(skb->dev); 463 struct net_device *odev; 464 struct ethhdr *eth; 465 466 if (!decap_and_validate(skb, IPPROTO_ETHERNET)) 467 goto drop; 468 469 if (!pskb_may_pull(skb, ETH_HLEN)) 470 goto drop; 471 472 skb_reset_mac_header(skb); 473 eth = (struct ethhdr *)skb->data; 474 475 /* To determine the frame's protocol, we assume it is 802.3. This avoids 476 * a call to eth_type_trans(), which is not really relevant for our 477 * use case. 478 */ 479 if (!eth_proto_is_802_3(eth->h_proto)) 480 goto drop; 481 482 odev = dev_get_by_index_rcu(net, slwt->oif); 483 if (!odev) 484 goto drop; 485 486 /* As we accept Ethernet frames, make sure the egress device is of 487 * the correct type. 488 */ 489 if (odev->type != ARPHRD_ETHER) 490 goto drop; 491 492 if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev)) 493 goto drop; 494 495 skb_orphan(skb); 496 497 if (skb_warn_if_lro(skb)) 498 goto drop; 499 500 skb_forward_csum(skb); 501 502 if (skb->len - ETH_HLEN > odev->mtu) 503 goto drop; 504 505 skb->dev = odev; 506 skb->protocol = eth->h_proto; 507 508 return dev_queue_xmit(skb); 509 510 drop: 511 kfree_skb(skb); 512 return -EINVAL; 513 } 514 515 static int input_action_end_dx6_finish(struct net *net, struct sock *sk, 516 struct sk_buff *skb) 517 { 518 struct dst_entry *orig_dst = skb_dst(skb); 519 struct in6_addr *nhaddr = NULL; 520 struct seg6_local_lwt *slwt; 521 522 slwt = seg6_local_lwtunnel(orig_dst->lwtstate); 523 524 /* The inner packet is not associated to any local interface, 525 * so we do not call netif_rx(). 526 * 527 * If slwt->nh6 is set to ::, then lookup the nexthop for the 528 * inner packet's DA. Otherwise, use the specified nexthop. 529 */ 530 if (!ipv6_addr_any(&slwt->nh6)) 531 nhaddr = &slwt->nh6; 532 533 seg6_lookup_nexthop(skb, nhaddr, 0); 534 535 return dst_input(skb); 536 } 537 538 /* decapsulate and forward to specified nexthop */ 539 static int input_action_end_dx6(struct sk_buff *skb, 540 struct seg6_local_lwt *slwt) 541 { 542 /* this function accepts IPv6 encapsulated packets, with either 543 * an SRH with SL=0, or no SRH. 544 */ 545 546 if (!decap_and_validate(skb, IPPROTO_IPV6)) 547 goto drop; 548 549 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 550 goto drop; 551 552 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 553 nf_reset_ct(skb); 554 555 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) 556 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, 557 dev_net(skb->dev), NULL, skb, NULL, 558 skb_dst(skb)->dev, input_action_end_dx6_finish); 559 560 return input_action_end_dx6_finish(dev_net(skb->dev), NULL, skb); 561 drop: 562 kfree_skb(skb); 563 return -EINVAL; 564 } 565 566 static int input_action_end_dx4_finish(struct net *net, struct sock *sk, 567 struct sk_buff *skb) 568 { 569 struct dst_entry *orig_dst = skb_dst(skb); 570 struct seg6_local_lwt *slwt; 571 struct iphdr *iph; 572 __be32 nhaddr; 573 int err; 574 575 slwt = seg6_local_lwtunnel(orig_dst->lwtstate); 576 577 iph = ip_hdr(skb); 578 579 nhaddr = slwt->nh4.s_addr ?: iph->daddr; 580 581 skb_dst_drop(skb); 582 583 err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev); 584 if (err) { 585 kfree_skb(skb); 586 return -EINVAL; 587 } 588 589 return dst_input(skb); 590 } 591 592 static int input_action_end_dx4(struct sk_buff *skb, 593 struct seg6_local_lwt *slwt) 594 { 595 if (!decap_and_validate(skb, IPPROTO_IPIP)) 596 goto drop; 597 598 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 599 goto drop; 600 601 skb->protocol = htons(ETH_P_IP); 602 skb_set_transport_header(skb, sizeof(struct iphdr)); 603 nf_reset_ct(skb); 604 605 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) 606 return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, 607 dev_net(skb->dev), NULL, skb, NULL, 608 skb_dst(skb)->dev, input_action_end_dx4_finish); 609 610 return input_action_end_dx4_finish(dev_net(skb->dev), NULL, skb); 611 drop: 612 kfree_skb(skb); 613 return -EINVAL; 614 } 615 616 #ifdef CONFIG_NET_L3_MASTER_DEV 617 static struct net *fib6_config_get_net(const struct fib6_config *fib6_cfg) 618 { 619 const struct nl_info *nli = &fib6_cfg->fc_nlinfo; 620 621 return nli->nl_net; 622 } 623 624 static int __seg6_end_dt_vrf_build(struct seg6_local_lwt *slwt, const void *cfg, 625 u16 family, struct netlink_ext_ack *extack) 626 { 627 struct seg6_end_dt_info *info = &slwt->dt_info; 628 int vrf_ifindex; 629 struct net *net; 630 631 net = fib6_config_get_net(cfg); 632 633 /* note that vrf_table was already set by parse_nla_vrftable() */ 634 vrf_ifindex = l3mdev_ifindex_lookup_by_table_id(L3MDEV_TYPE_VRF, net, 635 info->vrf_table); 636 if (vrf_ifindex < 0) { 637 if (vrf_ifindex == -EPERM) { 638 NL_SET_ERR_MSG(extack, 639 "Strict mode for VRF is disabled"); 640 } else if (vrf_ifindex == -ENODEV) { 641 NL_SET_ERR_MSG(extack, 642 "Table has no associated VRF device"); 643 } else { 644 pr_debug("seg6local: SRv6 End.DT* creation error=%d\n", 645 vrf_ifindex); 646 } 647 648 return vrf_ifindex; 649 } 650 651 info->net = net; 652 info->vrf_ifindex = vrf_ifindex; 653 654 info->family = family; 655 info->mode = DT_VRF_MODE; 656 657 return 0; 658 } 659 660 /* The SRv6 End.DT4/DT6 behavior extracts the inner (IPv4/IPv6) packet and 661 * routes the IPv4/IPv6 packet by looking at the configured routing table. 662 * 663 * In the SRv6 End.DT4/DT6 use case, we can receive traffic (IPv6+Segment 664 * Routing Header packets) from several interfaces and the outer IPv6 665 * destination address (DA) is used for retrieving the specific instance of the 666 * End.DT4/DT6 behavior that should process the packets. 667 * 668 * However, the inner IPv4/IPv6 packet is not really bound to any receiving 669 * interface and thus the End.DT4/DT6 sets the VRF (associated with the 670 * corresponding routing table) as the *receiving* interface. 671 * In other words, the End.DT4/DT6 processes a packet as if it has been received 672 * directly by the VRF (and not by one of its slave devices, if any). 673 * In this way, the VRF interface is used for routing the IPv4/IPv6 packet in 674 * according to the routing table configured by the End.DT4/DT6 instance. 675 * 676 * This design allows you to get some interesting features like: 677 * 1) the statistics on rx packets; 678 * 2) the possibility to install a packet sniffer on the receiving interface 679 * (the VRF one) for looking at the incoming packets; 680 * 3) the possibility to leverage the netfilter prerouting hook for the inner 681 * IPv4 packet. 682 * 683 * This function returns: 684 * - the sk_buff* when the VRF rcv handler has processed the packet correctly; 685 * - NULL when the skb is consumed by the VRF rcv handler; 686 * - a pointer which encodes a negative error number in case of error. 687 * Note that in this case, the function takes care of freeing the skb. 688 */ 689 static struct sk_buff *end_dt_vrf_rcv(struct sk_buff *skb, u16 family, 690 struct net_device *dev) 691 { 692 /* based on l3mdev_ip_rcv; we are only interested in the master */ 693 if (unlikely(!netif_is_l3_master(dev) && !netif_has_l3_rx_handler(dev))) 694 goto drop; 695 696 if (unlikely(!dev->l3mdev_ops->l3mdev_l3_rcv)) 697 goto drop; 698 699 /* the decap packet IPv4/IPv6 does not come with any mac header info. 700 * We must unset the mac header to allow the VRF device to rebuild it, 701 * just in case there is a sniffer attached on the device. 702 */ 703 skb_unset_mac_header(skb); 704 705 skb = dev->l3mdev_ops->l3mdev_l3_rcv(dev, skb, family); 706 if (!skb) 707 /* the skb buffer was consumed by the handler */ 708 return NULL; 709 710 /* when a packet is received by a VRF or by one of its slaves, the 711 * master device reference is set into the skb. 712 */ 713 if (unlikely(skb->dev != dev || skb->skb_iif != dev->ifindex)) 714 goto drop; 715 716 return skb; 717 718 drop: 719 kfree_skb(skb); 720 return ERR_PTR(-EINVAL); 721 } 722 723 static struct net_device *end_dt_get_vrf_rcu(struct sk_buff *skb, 724 struct seg6_end_dt_info *info) 725 { 726 int vrf_ifindex = info->vrf_ifindex; 727 struct net *net = info->net; 728 729 if (unlikely(vrf_ifindex < 0)) 730 goto error; 731 732 if (unlikely(!net_eq(dev_net(skb->dev), net))) 733 goto error; 734 735 return dev_get_by_index_rcu(net, vrf_ifindex); 736 737 error: 738 return NULL; 739 } 740 741 static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb, 742 struct seg6_local_lwt *slwt, u16 family) 743 { 744 struct seg6_end_dt_info *info = &slwt->dt_info; 745 struct net_device *vrf; 746 __be16 protocol; 747 int hdrlen; 748 749 vrf = end_dt_get_vrf_rcu(skb, info); 750 if (unlikely(!vrf)) 751 goto drop; 752 753 switch (family) { 754 case AF_INET: 755 protocol = htons(ETH_P_IP); 756 hdrlen = sizeof(struct iphdr); 757 break; 758 case AF_INET6: 759 protocol = htons(ETH_P_IPV6); 760 hdrlen = sizeof(struct ipv6hdr); 761 break; 762 case AF_UNSPEC: 763 fallthrough; 764 default: 765 goto drop; 766 } 767 768 if (unlikely(info->family != AF_UNSPEC && info->family != family)) { 769 pr_warn_once("seg6local: SRv6 End.DT* family mismatch"); 770 goto drop; 771 } 772 773 skb->protocol = protocol; 774 775 skb_dst_drop(skb); 776 777 skb_set_transport_header(skb, hdrlen); 778 nf_reset_ct(skb); 779 780 return end_dt_vrf_rcv(skb, family, vrf); 781 782 drop: 783 kfree_skb(skb); 784 return ERR_PTR(-EINVAL); 785 } 786 787 static int input_action_end_dt4(struct sk_buff *skb, 788 struct seg6_local_lwt *slwt) 789 { 790 struct iphdr *iph; 791 int err; 792 793 if (!decap_and_validate(skb, IPPROTO_IPIP)) 794 goto drop; 795 796 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 797 goto drop; 798 799 skb = end_dt_vrf_core(skb, slwt, AF_INET); 800 if (!skb) 801 /* packet has been processed and consumed by the VRF */ 802 return 0; 803 804 if (IS_ERR(skb)) 805 return PTR_ERR(skb); 806 807 iph = ip_hdr(skb); 808 809 err = ip_route_input(skb, iph->daddr, iph->saddr, 0, skb->dev); 810 if (unlikely(err)) 811 goto drop; 812 813 return dst_input(skb); 814 815 drop: 816 kfree_skb(skb); 817 return -EINVAL; 818 } 819 820 static int seg6_end_dt4_build(struct seg6_local_lwt *slwt, const void *cfg, 821 struct netlink_ext_ack *extack) 822 { 823 return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET, extack); 824 } 825 826 static enum 827 seg6_end_dt_mode seg6_end_dt6_parse_mode(struct seg6_local_lwt *slwt) 828 { 829 unsigned long parsed_optattrs = slwt->parsed_optattrs; 830 bool legacy, vrfmode; 831 832 legacy = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE)); 833 vrfmode = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE)); 834 835 if (!(legacy ^ vrfmode)) 836 /* both are absent or present: invalid DT6 mode */ 837 return DT_INVALID_MODE; 838 839 return legacy ? DT_LEGACY_MODE : DT_VRF_MODE; 840 } 841 842 static enum seg6_end_dt_mode seg6_end_dt6_get_mode(struct seg6_local_lwt *slwt) 843 { 844 struct seg6_end_dt_info *info = &slwt->dt_info; 845 846 return info->mode; 847 } 848 849 static int seg6_end_dt6_build(struct seg6_local_lwt *slwt, const void *cfg, 850 struct netlink_ext_ack *extack) 851 { 852 enum seg6_end_dt_mode mode = seg6_end_dt6_parse_mode(slwt); 853 struct seg6_end_dt_info *info = &slwt->dt_info; 854 855 switch (mode) { 856 case DT_LEGACY_MODE: 857 info->mode = DT_LEGACY_MODE; 858 return 0; 859 case DT_VRF_MODE: 860 return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET6, extack); 861 default: 862 NL_SET_ERR_MSG(extack, "table or vrftable must be specified"); 863 return -EINVAL; 864 } 865 } 866 #endif 867 868 static int input_action_end_dt6(struct sk_buff *skb, 869 struct seg6_local_lwt *slwt) 870 { 871 if (!decap_and_validate(skb, IPPROTO_IPV6)) 872 goto drop; 873 874 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 875 goto drop; 876 877 #ifdef CONFIG_NET_L3_MASTER_DEV 878 if (seg6_end_dt6_get_mode(slwt) == DT_LEGACY_MODE) 879 goto legacy_mode; 880 881 /* DT6_VRF_MODE */ 882 skb = end_dt_vrf_core(skb, slwt, AF_INET6); 883 if (!skb) 884 /* packet has been processed and consumed by the VRF */ 885 return 0; 886 887 if (IS_ERR(skb)) 888 return PTR_ERR(skb); 889 890 /* note: this time we do not need to specify the table because the VRF 891 * takes care of selecting the correct table. 892 */ 893 seg6_lookup_any_nexthop(skb, NULL, 0, true); 894 895 return dst_input(skb); 896 897 legacy_mode: 898 #endif 899 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 900 901 seg6_lookup_any_nexthop(skb, NULL, slwt->table, true); 902 903 return dst_input(skb); 904 905 drop: 906 kfree_skb(skb); 907 return -EINVAL; 908 } 909 910 #ifdef CONFIG_NET_L3_MASTER_DEV 911 static int seg6_end_dt46_build(struct seg6_local_lwt *slwt, const void *cfg, 912 struct netlink_ext_ack *extack) 913 { 914 return __seg6_end_dt_vrf_build(slwt, cfg, AF_UNSPEC, extack); 915 } 916 917 static int input_action_end_dt46(struct sk_buff *skb, 918 struct seg6_local_lwt *slwt) 919 { 920 unsigned int off = 0; 921 int nexthdr; 922 923 nexthdr = ipv6_find_hdr(skb, &off, -1, NULL, NULL); 924 if (unlikely(nexthdr < 0)) 925 goto drop; 926 927 switch (nexthdr) { 928 case IPPROTO_IPIP: 929 return input_action_end_dt4(skb, slwt); 930 case IPPROTO_IPV6: 931 return input_action_end_dt6(skb, slwt); 932 } 933 934 drop: 935 kfree_skb(skb); 936 return -EINVAL; 937 } 938 #endif 939 940 /* push an SRH on top of the current one */ 941 static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt) 942 { 943 struct ipv6_sr_hdr *srh; 944 int err = -EINVAL; 945 946 srh = get_and_validate_srh(skb); 947 if (!srh) 948 goto drop; 949 950 err = seg6_do_srh_inline(skb, slwt->srh); 951 if (err) 952 goto drop; 953 954 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 955 956 seg6_lookup_nexthop(skb, NULL, 0); 957 958 return dst_input(skb); 959 960 drop: 961 kfree_skb(skb); 962 return err; 963 } 964 965 /* encapsulate within an outer IPv6 header and a specified SRH */ 966 static int input_action_end_b6_encap(struct sk_buff *skb, 967 struct seg6_local_lwt *slwt) 968 { 969 struct ipv6_sr_hdr *srh; 970 int err = -EINVAL; 971 972 srh = get_and_validate_srh(skb); 973 if (!srh) 974 goto drop; 975 976 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 977 978 skb_reset_inner_headers(skb); 979 skb->encapsulation = 1; 980 981 err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6); 982 if (err) 983 goto drop; 984 985 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 986 987 seg6_lookup_nexthop(skb, NULL, 0); 988 989 return dst_input(skb); 990 991 drop: 992 kfree_skb(skb); 993 return err; 994 } 995 996 DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states); 997 998 bool seg6_bpf_has_valid_srh(struct sk_buff *skb) 999 { 1000 struct seg6_bpf_srh_state *srh_state = 1001 this_cpu_ptr(&seg6_bpf_srh_states); 1002 struct ipv6_sr_hdr *srh = srh_state->srh; 1003 1004 if (unlikely(srh == NULL)) 1005 return false; 1006 1007 if (unlikely(!srh_state->valid)) { 1008 if ((srh_state->hdrlen & 7) != 0) 1009 return false; 1010 1011 srh->hdrlen = (u8)(srh_state->hdrlen >> 3); 1012 if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3, true)) 1013 return false; 1014 1015 srh_state->valid = true; 1016 } 1017 1018 return true; 1019 } 1020 1021 static int input_action_end_bpf(struct sk_buff *skb, 1022 struct seg6_local_lwt *slwt) 1023 { 1024 struct seg6_bpf_srh_state *srh_state = 1025 this_cpu_ptr(&seg6_bpf_srh_states); 1026 struct ipv6_sr_hdr *srh; 1027 int ret; 1028 1029 srh = get_and_validate_srh(skb); 1030 if (!srh) { 1031 kfree_skb(skb); 1032 return -EINVAL; 1033 } 1034 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 1035 1036 /* preempt_disable is needed to protect the per-CPU buffer srh_state, 1037 * which is also accessed by the bpf_lwt_seg6_* helpers 1038 */ 1039 preempt_disable(); 1040 srh_state->srh = srh; 1041 srh_state->hdrlen = srh->hdrlen << 3; 1042 srh_state->valid = true; 1043 1044 rcu_read_lock(); 1045 bpf_compute_data_pointers(skb); 1046 ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb); 1047 rcu_read_unlock(); 1048 1049 switch (ret) { 1050 case BPF_OK: 1051 case BPF_REDIRECT: 1052 break; 1053 case BPF_DROP: 1054 goto drop; 1055 default: 1056 pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret); 1057 goto drop; 1058 } 1059 1060 if (srh_state->srh && !seg6_bpf_has_valid_srh(skb)) 1061 goto drop; 1062 1063 preempt_enable(); 1064 if (ret != BPF_REDIRECT) 1065 seg6_lookup_nexthop(skb, NULL, 0); 1066 1067 return dst_input(skb); 1068 1069 drop: 1070 preempt_enable(); 1071 kfree_skb(skb); 1072 return -EINVAL; 1073 } 1074 1075 static struct seg6_action_desc seg6_action_table[] = { 1076 { 1077 .action = SEG6_LOCAL_ACTION_END, 1078 .attrs = 0, 1079 .optattrs = SEG6_F_LOCAL_COUNTERS | 1080 SEG6_F_ATTR(SEG6_LOCAL_FLAVORS), 1081 .input = input_action_end, 1082 }, 1083 { 1084 .action = SEG6_LOCAL_ACTION_END_X, 1085 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6), 1086 .optattrs = SEG6_F_LOCAL_COUNTERS, 1087 .input = input_action_end_x, 1088 }, 1089 { 1090 .action = SEG6_LOCAL_ACTION_END_T, 1091 .attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE), 1092 .optattrs = SEG6_F_LOCAL_COUNTERS, 1093 .input = input_action_end_t, 1094 }, 1095 { 1096 .action = SEG6_LOCAL_ACTION_END_DX2, 1097 .attrs = SEG6_F_ATTR(SEG6_LOCAL_OIF), 1098 .optattrs = SEG6_F_LOCAL_COUNTERS, 1099 .input = input_action_end_dx2, 1100 }, 1101 { 1102 .action = SEG6_LOCAL_ACTION_END_DX6, 1103 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6), 1104 .optattrs = SEG6_F_LOCAL_COUNTERS, 1105 .input = input_action_end_dx6, 1106 }, 1107 { 1108 .action = SEG6_LOCAL_ACTION_END_DX4, 1109 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH4), 1110 .optattrs = SEG6_F_LOCAL_COUNTERS, 1111 .input = input_action_end_dx4, 1112 }, 1113 { 1114 .action = SEG6_LOCAL_ACTION_END_DT4, 1115 .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1116 .optattrs = SEG6_F_LOCAL_COUNTERS, 1117 #ifdef CONFIG_NET_L3_MASTER_DEV 1118 .input = input_action_end_dt4, 1119 .slwt_ops = { 1120 .build_state = seg6_end_dt4_build, 1121 }, 1122 #endif 1123 }, 1124 { 1125 .action = SEG6_LOCAL_ACTION_END_DT6, 1126 #ifdef CONFIG_NET_L3_MASTER_DEV 1127 .attrs = 0, 1128 .optattrs = SEG6_F_LOCAL_COUNTERS | 1129 SEG6_F_ATTR(SEG6_LOCAL_TABLE) | 1130 SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1131 .slwt_ops = { 1132 .build_state = seg6_end_dt6_build, 1133 }, 1134 #else 1135 .attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE), 1136 .optattrs = SEG6_F_LOCAL_COUNTERS, 1137 #endif 1138 .input = input_action_end_dt6, 1139 }, 1140 { 1141 .action = SEG6_LOCAL_ACTION_END_DT46, 1142 .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1143 .optattrs = SEG6_F_LOCAL_COUNTERS, 1144 #ifdef CONFIG_NET_L3_MASTER_DEV 1145 .input = input_action_end_dt46, 1146 .slwt_ops = { 1147 .build_state = seg6_end_dt46_build, 1148 }, 1149 #endif 1150 }, 1151 { 1152 .action = SEG6_LOCAL_ACTION_END_B6, 1153 .attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH), 1154 .optattrs = SEG6_F_LOCAL_COUNTERS, 1155 .input = input_action_end_b6, 1156 }, 1157 { 1158 .action = SEG6_LOCAL_ACTION_END_B6_ENCAP, 1159 .attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH), 1160 .optattrs = SEG6_F_LOCAL_COUNTERS, 1161 .input = input_action_end_b6_encap, 1162 .static_headroom = sizeof(struct ipv6hdr), 1163 }, 1164 { 1165 .action = SEG6_LOCAL_ACTION_END_BPF, 1166 .attrs = SEG6_F_ATTR(SEG6_LOCAL_BPF), 1167 .optattrs = SEG6_F_LOCAL_COUNTERS, 1168 .input = input_action_end_bpf, 1169 }, 1170 1171 }; 1172 1173 static struct seg6_action_desc *__get_action_desc(int action) 1174 { 1175 struct seg6_action_desc *desc; 1176 int i, count; 1177 1178 count = ARRAY_SIZE(seg6_action_table); 1179 for (i = 0; i < count; i++) { 1180 desc = &seg6_action_table[i]; 1181 if (desc->action == action) 1182 return desc; 1183 } 1184 1185 return NULL; 1186 } 1187 1188 static bool seg6_lwtunnel_counters_enabled(struct seg6_local_lwt *slwt) 1189 { 1190 return slwt->parsed_optattrs & SEG6_F_LOCAL_COUNTERS; 1191 } 1192 1193 static void seg6_local_update_counters(struct seg6_local_lwt *slwt, 1194 unsigned int len, int err) 1195 { 1196 struct pcpu_seg6_local_counters *pcounters; 1197 1198 pcounters = this_cpu_ptr(slwt->pcpu_counters); 1199 u64_stats_update_begin(&pcounters->syncp); 1200 1201 if (likely(!err)) { 1202 u64_stats_inc(&pcounters->packets); 1203 u64_stats_add(&pcounters->bytes, len); 1204 } else { 1205 u64_stats_inc(&pcounters->errors); 1206 } 1207 1208 u64_stats_update_end(&pcounters->syncp); 1209 } 1210 1211 static int seg6_local_input_core(struct net *net, struct sock *sk, 1212 struct sk_buff *skb) 1213 { 1214 struct dst_entry *orig_dst = skb_dst(skb); 1215 struct seg6_action_desc *desc; 1216 struct seg6_local_lwt *slwt; 1217 unsigned int len = skb->len; 1218 int rc; 1219 1220 slwt = seg6_local_lwtunnel(orig_dst->lwtstate); 1221 desc = slwt->desc; 1222 1223 rc = desc->input(skb, slwt); 1224 1225 if (!seg6_lwtunnel_counters_enabled(slwt)) 1226 return rc; 1227 1228 seg6_local_update_counters(slwt, len, rc); 1229 1230 return rc; 1231 } 1232 1233 static int seg6_local_input(struct sk_buff *skb) 1234 { 1235 if (skb->protocol != htons(ETH_P_IPV6)) { 1236 kfree_skb(skb); 1237 return -EINVAL; 1238 } 1239 1240 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) 1241 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, 1242 dev_net(skb->dev), NULL, skb, skb->dev, NULL, 1243 seg6_local_input_core); 1244 1245 return seg6_local_input_core(dev_net(skb->dev), NULL, skb); 1246 } 1247 1248 static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = { 1249 [SEG6_LOCAL_ACTION] = { .type = NLA_U32 }, 1250 [SEG6_LOCAL_SRH] = { .type = NLA_BINARY }, 1251 [SEG6_LOCAL_TABLE] = { .type = NLA_U32 }, 1252 [SEG6_LOCAL_VRFTABLE] = { .type = NLA_U32 }, 1253 [SEG6_LOCAL_NH4] = { .type = NLA_BINARY, 1254 .len = sizeof(struct in_addr) }, 1255 [SEG6_LOCAL_NH6] = { .type = NLA_BINARY, 1256 .len = sizeof(struct in6_addr) }, 1257 [SEG6_LOCAL_IIF] = { .type = NLA_U32 }, 1258 [SEG6_LOCAL_OIF] = { .type = NLA_U32 }, 1259 [SEG6_LOCAL_BPF] = { .type = NLA_NESTED }, 1260 [SEG6_LOCAL_COUNTERS] = { .type = NLA_NESTED }, 1261 [SEG6_LOCAL_FLAVORS] = { .type = NLA_NESTED }, 1262 }; 1263 1264 static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1265 struct netlink_ext_ack *extack) 1266 { 1267 struct ipv6_sr_hdr *srh; 1268 int len; 1269 1270 srh = nla_data(attrs[SEG6_LOCAL_SRH]); 1271 len = nla_len(attrs[SEG6_LOCAL_SRH]); 1272 1273 /* SRH must contain at least one segment */ 1274 if (len < sizeof(*srh) + sizeof(struct in6_addr)) 1275 return -EINVAL; 1276 1277 if (!seg6_validate_srh(srh, len, false)) 1278 return -EINVAL; 1279 1280 slwt->srh = kmemdup(srh, len, GFP_KERNEL); 1281 if (!slwt->srh) 1282 return -ENOMEM; 1283 1284 slwt->headroom += len; 1285 1286 return 0; 1287 } 1288 1289 static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1290 { 1291 struct ipv6_sr_hdr *srh; 1292 struct nlattr *nla; 1293 int len; 1294 1295 srh = slwt->srh; 1296 len = (srh->hdrlen + 1) << 3; 1297 1298 nla = nla_reserve(skb, SEG6_LOCAL_SRH, len); 1299 if (!nla) 1300 return -EMSGSIZE; 1301 1302 memcpy(nla_data(nla), srh, len); 1303 1304 return 0; 1305 } 1306 1307 static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1308 { 1309 int len = (a->srh->hdrlen + 1) << 3; 1310 1311 if (len != ((b->srh->hdrlen + 1) << 3)) 1312 return 1; 1313 1314 return memcmp(a->srh, b->srh, len); 1315 } 1316 1317 static void destroy_attr_srh(struct seg6_local_lwt *slwt) 1318 { 1319 kfree(slwt->srh); 1320 } 1321 1322 static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1323 struct netlink_ext_ack *extack) 1324 { 1325 slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]); 1326 1327 return 0; 1328 } 1329 1330 static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1331 { 1332 if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table)) 1333 return -EMSGSIZE; 1334 1335 return 0; 1336 } 1337 1338 static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1339 { 1340 if (a->table != b->table) 1341 return 1; 1342 1343 return 0; 1344 } 1345 1346 static struct 1347 seg6_end_dt_info *seg6_possible_end_dt_info(struct seg6_local_lwt *slwt) 1348 { 1349 #ifdef CONFIG_NET_L3_MASTER_DEV 1350 return &slwt->dt_info; 1351 #else 1352 return ERR_PTR(-EOPNOTSUPP); 1353 #endif 1354 } 1355 1356 static int parse_nla_vrftable(struct nlattr **attrs, 1357 struct seg6_local_lwt *slwt, 1358 struct netlink_ext_ack *extack) 1359 { 1360 struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt); 1361 1362 if (IS_ERR(info)) 1363 return PTR_ERR(info); 1364 1365 info->vrf_table = nla_get_u32(attrs[SEG6_LOCAL_VRFTABLE]); 1366 1367 return 0; 1368 } 1369 1370 static int put_nla_vrftable(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1371 { 1372 struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt); 1373 1374 if (IS_ERR(info)) 1375 return PTR_ERR(info); 1376 1377 if (nla_put_u32(skb, SEG6_LOCAL_VRFTABLE, info->vrf_table)) 1378 return -EMSGSIZE; 1379 1380 return 0; 1381 } 1382 1383 static int cmp_nla_vrftable(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1384 { 1385 struct seg6_end_dt_info *info_a = seg6_possible_end_dt_info(a); 1386 struct seg6_end_dt_info *info_b = seg6_possible_end_dt_info(b); 1387 1388 if (info_a->vrf_table != info_b->vrf_table) 1389 return 1; 1390 1391 return 0; 1392 } 1393 1394 static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1395 struct netlink_ext_ack *extack) 1396 { 1397 memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]), 1398 sizeof(struct in_addr)); 1399 1400 return 0; 1401 } 1402 1403 static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1404 { 1405 struct nlattr *nla; 1406 1407 nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr)); 1408 if (!nla) 1409 return -EMSGSIZE; 1410 1411 memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr)); 1412 1413 return 0; 1414 } 1415 1416 static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1417 { 1418 return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr)); 1419 } 1420 1421 static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1422 struct netlink_ext_ack *extack) 1423 { 1424 memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]), 1425 sizeof(struct in6_addr)); 1426 1427 return 0; 1428 } 1429 1430 static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1431 { 1432 struct nlattr *nla; 1433 1434 nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr)); 1435 if (!nla) 1436 return -EMSGSIZE; 1437 1438 memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr)); 1439 1440 return 0; 1441 } 1442 1443 static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1444 { 1445 return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr)); 1446 } 1447 1448 static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1449 struct netlink_ext_ack *extack) 1450 { 1451 slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]); 1452 1453 return 0; 1454 } 1455 1456 static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1457 { 1458 if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif)) 1459 return -EMSGSIZE; 1460 1461 return 0; 1462 } 1463 1464 static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1465 { 1466 if (a->iif != b->iif) 1467 return 1; 1468 1469 return 0; 1470 } 1471 1472 static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1473 struct netlink_ext_ack *extack) 1474 { 1475 slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]); 1476 1477 return 0; 1478 } 1479 1480 static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1481 { 1482 if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif)) 1483 return -EMSGSIZE; 1484 1485 return 0; 1486 } 1487 1488 static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1489 { 1490 if (a->oif != b->oif) 1491 return 1; 1492 1493 return 0; 1494 } 1495 1496 #define MAX_PROG_NAME 256 1497 static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = { 1498 [SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, }, 1499 [SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING, 1500 .len = MAX_PROG_NAME }, 1501 }; 1502 1503 static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1504 struct netlink_ext_ack *extack) 1505 { 1506 struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1]; 1507 struct bpf_prog *p; 1508 int ret; 1509 u32 fd; 1510 1511 ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_BPF_PROG_MAX, 1512 attrs[SEG6_LOCAL_BPF], 1513 bpf_prog_policy, NULL); 1514 if (ret < 0) 1515 return ret; 1516 1517 if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME]) 1518 return -EINVAL; 1519 1520 slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL); 1521 if (!slwt->bpf.name) 1522 return -ENOMEM; 1523 1524 fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]); 1525 p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL); 1526 if (IS_ERR(p)) { 1527 kfree(slwt->bpf.name); 1528 return PTR_ERR(p); 1529 } 1530 1531 slwt->bpf.prog = p; 1532 return 0; 1533 } 1534 1535 static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1536 { 1537 struct nlattr *nest; 1538 1539 if (!slwt->bpf.prog) 1540 return 0; 1541 1542 nest = nla_nest_start_noflag(skb, SEG6_LOCAL_BPF); 1543 if (!nest) 1544 return -EMSGSIZE; 1545 1546 if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id)) 1547 return -EMSGSIZE; 1548 1549 if (slwt->bpf.name && 1550 nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name)) 1551 return -EMSGSIZE; 1552 1553 return nla_nest_end(skb, nest); 1554 } 1555 1556 static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1557 { 1558 if (!a->bpf.name && !b->bpf.name) 1559 return 0; 1560 1561 if (!a->bpf.name || !b->bpf.name) 1562 return 1; 1563 1564 return strcmp(a->bpf.name, b->bpf.name); 1565 } 1566 1567 static void destroy_attr_bpf(struct seg6_local_lwt *slwt) 1568 { 1569 kfree(slwt->bpf.name); 1570 if (slwt->bpf.prog) 1571 bpf_prog_put(slwt->bpf.prog); 1572 } 1573 1574 static const struct 1575 nla_policy seg6_local_counters_policy[SEG6_LOCAL_CNT_MAX + 1] = { 1576 [SEG6_LOCAL_CNT_PACKETS] = { .type = NLA_U64 }, 1577 [SEG6_LOCAL_CNT_BYTES] = { .type = NLA_U64 }, 1578 [SEG6_LOCAL_CNT_ERRORS] = { .type = NLA_U64 }, 1579 }; 1580 1581 static int parse_nla_counters(struct nlattr **attrs, 1582 struct seg6_local_lwt *slwt, 1583 struct netlink_ext_ack *extack) 1584 { 1585 struct pcpu_seg6_local_counters __percpu *pcounters; 1586 struct nlattr *tb[SEG6_LOCAL_CNT_MAX + 1]; 1587 int ret; 1588 1589 ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_CNT_MAX, 1590 attrs[SEG6_LOCAL_COUNTERS], 1591 seg6_local_counters_policy, NULL); 1592 if (ret < 0) 1593 return ret; 1594 1595 /* basic support for SRv6 Behavior counters requires at least: 1596 * packets, bytes and errors. 1597 */ 1598 if (!tb[SEG6_LOCAL_CNT_PACKETS] || !tb[SEG6_LOCAL_CNT_BYTES] || 1599 !tb[SEG6_LOCAL_CNT_ERRORS]) 1600 return -EINVAL; 1601 1602 /* counters are always zero initialized */ 1603 pcounters = seg6_local_alloc_pcpu_counters(GFP_KERNEL); 1604 if (!pcounters) 1605 return -ENOMEM; 1606 1607 slwt->pcpu_counters = pcounters; 1608 1609 return 0; 1610 } 1611 1612 static int seg6_local_fill_nla_counters(struct sk_buff *skb, 1613 struct seg6_local_counters *counters) 1614 { 1615 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_PACKETS, counters->packets, 1616 SEG6_LOCAL_CNT_PAD)) 1617 return -EMSGSIZE; 1618 1619 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_BYTES, counters->bytes, 1620 SEG6_LOCAL_CNT_PAD)) 1621 return -EMSGSIZE; 1622 1623 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_ERRORS, counters->errors, 1624 SEG6_LOCAL_CNT_PAD)) 1625 return -EMSGSIZE; 1626 1627 return 0; 1628 } 1629 1630 static int put_nla_counters(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1631 { 1632 struct seg6_local_counters counters = { 0, 0, 0 }; 1633 struct nlattr *nest; 1634 int rc, i; 1635 1636 nest = nla_nest_start(skb, SEG6_LOCAL_COUNTERS); 1637 if (!nest) 1638 return -EMSGSIZE; 1639 1640 for_each_possible_cpu(i) { 1641 struct pcpu_seg6_local_counters *pcounters; 1642 u64 packets, bytes, errors; 1643 unsigned int start; 1644 1645 pcounters = per_cpu_ptr(slwt->pcpu_counters, i); 1646 do { 1647 start = u64_stats_fetch_begin(&pcounters->syncp); 1648 1649 packets = u64_stats_read(&pcounters->packets); 1650 bytes = u64_stats_read(&pcounters->bytes); 1651 errors = u64_stats_read(&pcounters->errors); 1652 1653 } while (u64_stats_fetch_retry(&pcounters->syncp, start)); 1654 1655 counters.packets += packets; 1656 counters.bytes += bytes; 1657 counters.errors += errors; 1658 } 1659 1660 rc = seg6_local_fill_nla_counters(skb, &counters); 1661 if (rc < 0) { 1662 nla_nest_cancel(skb, nest); 1663 return rc; 1664 } 1665 1666 return nla_nest_end(skb, nest); 1667 } 1668 1669 static int cmp_nla_counters(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1670 { 1671 /* a and b are equal if both have pcpu_counters set or not */ 1672 return (!!((unsigned long)a->pcpu_counters)) ^ 1673 (!!((unsigned long)b->pcpu_counters)); 1674 } 1675 1676 static void destroy_attr_counters(struct seg6_local_lwt *slwt) 1677 { 1678 free_percpu(slwt->pcpu_counters); 1679 } 1680 1681 static const 1682 struct nla_policy seg6_local_flavors_policy[SEG6_LOCAL_FLV_MAX + 1] = { 1683 [SEG6_LOCAL_FLV_OPERATION] = { .type = NLA_U32 }, 1684 [SEG6_LOCAL_FLV_LCBLOCK_BITS] = { .type = NLA_U8 }, 1685 [SEG6_LOCAL_FLV_LCNODE_FN_BITS] = { .type = NLA_U8 }, 1686 }; 1687 1688 /* check whether the lengths of the Locator-Block and Locator-Node Function 1689 * are compatible with the dimension of a C-SID container. 1690 */ 1691 static int seg6_chk_next_csid_cfg(__u8 block_len, __u8 func_len) 1692 { 1693 /* Locator-Block and Locator-Node Function cannot exceed 128 bits 1694 * (i.e. C-SID container lenghts). 1695 */ 1696 if (next_csid_chk_cntr_bits(block_len, func_len)) 1697 return -EINVAL; 1698 1699 /* Locator-Block length must be greater than zero and evenly divisible 1700 * by 8. There must be room for a Locator-Node Function, at least. 1701 */ 1702 if (next_csid_chk_lcblock_bits(block_len)) 1703 return -EINVAL; 1704 1705 /* Locator-Node Function length must be greater than zero and evenly 1706 * divisible by 8. There must be room for the Locator-Block. 1707 */ 1708 if (next_csid_chk_lcnode_fn_bits(func_len)) 1709 return -EINVAL; 1710 1711 return 0; 1712 } 1713 1714 static int seg6_parse_nla_next_csid_cfg(struct nlattr **tb, 1715 struct seg6_flavors_info *finfo, 1716 struct netlink_ext_ack *extack) 1717 { 1718 __u8 func_len = SEG6_LOCAL_LCNODE_FN_DBITS; 1719 __u8 block_len = SEG6_LOCAL_LCBLOCK_DBITS; 1720 int rc; 1721 1722 if (tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]) 1723 block_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]); 1724 1725 if (tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]) 1726 func_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]); 1727 1728 rc = seg6_chk_next_csid_cfg(block_len, func_len); 1729 if (rc < 0) { 1730 NL_SET_ERR_MSG(extack, 1731 "Invalid Locator Block/Node Function lengths"); 1732 return rc; 1733 } 1734 1735 finfo->lcblock_bits = block_len; 1736 finfo->lcnode_func_bits = func_len; 1737 1738 return 0; 1739 } 1740 1741 static int parse_nla_flavors(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1742 struct netlink_ext_ack *extack) 1743 { 1744 struct seg6_flavors_info *finfo = &slwt->flv_info; 1745 struct nlattr *tb[SEG6_LOCAL_FLV_MAX + 1]; 1746 unsigned long fops; 1747 int rc; 1748 1749 rc = nla_parse_nested_deprecated(tb, SEG6_LOCAL_FLV_MAX, 1750 attrs[SEG6_LOCAL_FLAVORS], 1751 seg6_local_flavors_policy, NULL); 1752 if (rc < 0) 1753 return rc; 1754 1755 /* this attribute MUST always be present since it represents the Flavor 1756 * operation(s) to be carried out. 1757 */ 1758 if (!tb[SEG6_LOCAL_FLV_OPERATION]) 1759 return -EINVAL; 1760 1761 fops = nla_get_u32(tb[SEG6_LOCAL_FLV_OPERATION]); 1762 if (fops & ~SEG6_LOCAL_FLV_SUPP_OPS) { 1763 NL_SET_ERR_MSG(extack, "Unsupported Flavor operation(s)"); 1764 return -EOPNOTSUPP; 1765 } 1766 1767 finfo->flv_ops = fops; 1768 1769 if (seg6_next_csid_enabled(fops)) { 1770 /* Locator-Block and Locator-Node Function lengths can be 1771 * provided by the user space. Otherwise, default values are 1772 * applied. 1773 */ 1774 rc = seg6_parse_nla_next_csid_cfg(tb, finfo, extack); 1775 if (rc < 0) 1776 return rc; 1777 } 1778 1779 return 0; 1780 } 1781 1782 static int seg6_fill_nla_next_csid_cfg(struct sk_buff *skb, 1783 struct seg6_flavors_info *finfo) 1784 { 1785 if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCBLOCK_BITS, finfo->lcblock_bits)) 1786 return -EMSGSIZE; 1787 1788 if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCNODE_FN_BITS, 1789 finfo->lcnode_func_bits)) 1790 return -EMSGSIZE; 1791 1792 return 0; 1793 } 1794 1795 static int put_nla_flavors(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1796 { 1797 struct seg6_flavors_info *finfo = &slwt->flv_info; 1798 __u32 fops = finfo->flv_ops; 1799 struct nlattr *nest; 1800 int rc; 1801 1802 nest = nla_nest_start(skb, SEG6_LOCAL_FLAVORS); 1803 if (!nest) 1804 return -EMSGSIZE; 1805 1806 if (nla_put_u32(skb, SEG6_LOCAL_FLV_OPERATION, fops)) { 1807 rc = -EMSGSIZE; 1808 goto err; 1809 } 1810 1811 if (seg6_next_csid_enabled(fops)) { 1812 rc = seg6_fill_nla_next_csid_cfg(skb, finfo); 1813 if (rc < 0) 1814 goto err; 1815 } 1816 1817 return nla_nest_end(skb, nest); 1818 1819 err: 1820 nla_nest_cancel(skb, nest); 1821 return rc; 1822 } 1823 1824 static int seg6_cmp_nla_next_csid_cfg(struct seg6_flavors_info *finfo_a, 1825 struct seg6_flavors_info *finfo_b) 1826 { 1827 if (finfo_a->lcblock_bits != finfo_b->lcblock_bits) 1828 return 1; 1829 1830 if (finfo_a->lcnode_func_bits != finfo_b->lcnode_func_bits) 1831 return 1; 1832 1833 return 0; 1834 } 1835 1836 static int cmp_nla_flavors(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1837 { 1838 struct seg6_flavors_info *finfo_a = &a->flv_info; 1839 struct seg6_flavors_info *finfo_b = &b->flv_info; 1840 1841 if (finfo_a->flv_ops != finfo_b->flv_ops) 1842 return 1; 1843 1844 if (seg6_next_csid_enabled(finfo_a->flv_ops)) { 1845 if (seg6_cmp_nla_next_csid_cfg(finfo_a, finfo_b)) 1846 return 1; 1847 } 1848 1849 return 0; 1850 } 1851 1852 static int encap_size_flavors(struct seg6_local_lwt *slwt) 1853 { 1854 struct seg6_flavors_info *finfo = &slwt->flv_info; 1855 int nlsize; 1856 1857 nlsize = nla_total_size(0) + /* nest SEG6_LOCAL_FLAVORS */ 1858 nla_total_size(4); /* SEG6_LOCAL_FLV_OPERATION */ 1859 1860 if (seg6_next_csid_enabled(finfo->flv_ops)) 1861 nlsize += nla_total_size(1) + /* SEG6_LOCAL_FLV_LCBLOCK_BITS */ 1862 nla_total_size(1); /* SEG6_LOCAL_FLV_LCNODE_FN_BITS */ 1863 1864 return nlsize; 1865 } 1866 1867 struct seg6_action_param { 1868 int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1869 struct netlink_ext_ack *extack); 1870 int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt); 1871 int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b); 1872 1873 /* optional destroy() callback useful for releasing resources which 1874 * have been previously acquired in the corresponding parse() 1875 * function. 1876 */ 1877 void (*destroy)(struct seg6_local_lwt *slwt); 1878 }; 1879 1880 static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = { 1881 [SEG6_LOCAL_SRH] = { .parse = parse_nla_srh, 1882 .put = put_nla_srh, 1883 .cmp = cmp_nla_srh, 1884 .destroy = destroy_attr_srh }, 1885 1886 [SEG6_LOCAL_TABLE] = { .parse = parse_nla_table, 1887 .put = put_nla_table, 1888 .cmp = cmp_nla_table }, 1889 1890 [SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4, 1891 .put = put_nla_nh4, 1892 .cmp = cmp_nla_nh4 }, 1893 1894 [SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6, 1895 .put = put_nla_nh6, 1896 .cmp = cmp_nla_nh6 }, 1897 1898 [SEG6_LOCAL_IIF] = { .parse = parse_nla_iif, 1899 .put = put_nla_iif, 1900 .cmp = cmp_nla_iif }, 1901 1902 [SEG6_LOCAL_OIF] = { .parse = parse_nla_oif, 1903 .put = put_nla_oif, 1904 .cmp = cmp_nla_oif }, 1905 1906 [SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf, 1907 .put = put_nla_bpf, 1908 .cmp = cmp_nla_bpf, 1909 .destroy = destroy_attr_bpf }, 1910 1911 [SEG6_LOCAL_VRFTABLE] = { .parse = parse_nla_vrftable, 1912 .put = put_nla_vrftable, 1913 .cmp = cmp_nla_vrftable }, 1914 1915 [SEG6_LOCAL_COUNTERS] = { .parse = parse_nla_counters, 1916 .put = put_nla_counters, 1917 .cmp = cmp_nla_counters, 1918 .destroy = destroy_attr_counters }, 1919 1920 [SEG6_LOCAL_FLAVORS] = { .parse = parse_nla_flavors, 1921 .put = put_nla_flavors, 1922 .cmp = cmp_nla_flavors }, 1923 }; 1924 1925 /* call the destroy() callback (if available) for each set attribute in 1926 * @parsed_attrs, starting from the first attribute up to the @max_parsed 1927 * (excluded) attribute. 1928 */ 1929 static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed, 1930 struct seg6_local_lwt *slwt) 1931 { 1932 struct seg6_action_param *param; 1933 int i; 1934 1935 /* Every required seg6local attribute is identified by an ID which is 1936 * encoded as a flag (i.e: 1 << ID) in the 'attrs' bitmask; 1937 * 1938 * We scan the 'parsed_attrs' bitmask, starting from the first attribute 1939 * up to the @max_parsed (excluded) attribute. 1940 * For each set attribute, we retrieve the corresponding destroy() 1941 * callback. If the callback is not available, then we skip to the next 1942 * attribute; otherwise, we call the destroy() callback. 1943 */ 1944 for (i = SEG6_LOCAL_SRH; i < max_parsed; ++i) { 1945 if (!(parsed_attrs & SEG6_F_ATTR(i))) 1946 continue; 1947 1948 param = &seg6_action_params[i]; 1949 1950 if (param->destroy) 1951 param->destroy(slwt); 1952 } 1953 } 1954 1955 /* release all the resources that may have been acquired during parsing 1956 * operations. 1957 */ 1958 static void destroy_attrs(struct seg6_local_lwt *slwt) 1959 { 1960 unsigned long attrs = slwt->desc->attrs | slwt->parsed_optattrs; 1961 1962 __destroy_attrs(attrs, SEG6_LOCAL_MAX + 1, slwt); 1963 } 1964 1965 static int parse_nla_optional_attrs(struct nlattr **attrs, 1966 struct seg6_local_lwt *slwt, 1967 struct netlink_ext_ack *extack) 1968 { 1969 struct seg6_action_desc *desc = slwt->desc; 1970 unsigned long parsed_optattrs = 0; 1971 struct seg6_action_param *param; 1972 int err, i; 1973 1974 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; ++i) { 1975 if (!(desc->optattrs & SEG6_F_ATTR(i)) || !attrs[i]) 1976 continue; 1977 1978 /* once here, the i-th attribute is provided by the 1979 * userspace AND it is identified optional as well. 1980 */ 1981 param = &seg6_action_params[i]; 1982 1983 err = param->parse(attrs, slwt, extack); 1984 if (err < 0) 1985 goto parse_optattrs_err; 1986 1987 /* current attribute has been correctly parsed */ 1988 parsed_optattrs |= SEG6_F_ATTR(i); 1989 } 1990 1991 /* store in the tunnel state all the optional attributed successfully 1992 * parsed. 1993 */ 1994 slwt->parsed_optattrs = parsed_optattrs; 1995 1996 return 0; 1997 1998 parse_optattrs_err: 1999 __destroy_attrs(parsed_optattrs, i, slwt); 2000 2001 return err; 2002 } 2003 2004 /* call the custom constructor of the behavior during its initialization phase 2005 * and after that all its attributes have been parsed successfully. 2006 */ 2007 static int 2008 seg6_local_lwtunnel_build_state(struct seg6_local_lwt *slwt, const void *cfg, 2009 struct netlink_ext_ack *extack) 2010 { 2011 struct seg6_action_desc *desc = slwt->desc; 2012 struct seg6_local_lwtunnel_ops *ops; 2013 2014 ops = &desc->slwt_ops; 2015 if (!ops->build_state) 2016 return 0; 2017 2018 return ops->build_state(slwt, cfg, extack); 2019 } 2020 2021 /* call the custom destructor of the behavior which is invoked before the 2022 * tunnel is going to be destroyed. 2023 */ 2024 static void seg6_local_lwtunnel_destroy_state(struct seg6_local_lwt *slwt) 2025 { 2026 struct seg6_action_desc *desc = slwt->desc; 2027 struct seg6_local_lwtunnel_ops *ops; 2028 2029 ops = &desc->slwt_ops; 2030 if (!ops->destroy_state) 2031 return; 2032 2033 ops->destroy_state(slwt); 2034 } 2035 2036 static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt, 2037 struct netlink_ext_ack *extack) 2038 { 2039 struct seg6_action_param *param; 2040 struct seg6_action_desc *desc; 2041 unsigned long invalid_attrs; 2042 int i, err; 2043 2044 desc = __get_action_desc(slwt->action); 2045 if (!desc) 2046 return -EINVAL; 2047 2048 if (!desc->input) 2049 return -EOPNOTSUPP; 2050 2051 slwt->desc = desc; 2052 slwt->headroom += desc->static_headroom; 2053 2054 /* Forcing the desc->optattrs *set* and the desc->attrs *set* to be 2055 * disjoined, this allow us to release acquired resources by optional 2056 * attributes and by required attributes independently from each other 2057 * without any interference. 2058 * In other terms, we are sure that we do not release some the acquired 2059 * resources twice. 2060 * 2061 * Note that if an attribute is configured both as required and as 2062 * optional, it means that the user has messed something up in the 2063 * seg6_action_table. Therefore, this check is required for SRv6 2064 * behaviors to work properly. 2065 */ 2066 invalid_attrs = desc->attrs & desc->optattrs; 2067 if (invalid_attrs) { 2068 WARN_ONCE(1, 2069 "An attribute cannot be both required AND optional"); 2070 return -EINVAL; 2071 } 2072 2073 /* parse the required attributes */ 2074 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2075 if (desc->attrs & SEG6_F_ATTR(i)) { 2076 if (!attrs[i]) 2077 return -EINVAL; 2078 2079 param = &seg6_action_params[i]; 2080 2081 err = param->parse(attrs, slwt, extack); 2082 if (err < 0) 2083 goto parse_attrs_err; 2084 } 2085 } 2086 2087 /* parse the optional attributes, if any */ 2088 err = parse_nla_optional_attrs(attrs, slwt, extack); 2089 if (err < 0) 2090 goto parse_attrs_err; 2091 2092 return 0; 2093 2094 parse_attrs_err: 2095 /* release any resource that may have been acquired during the i-1 2096 * parse() operations. 2097 */ 2098 __destroy_attrs(desc->attrs, i, slwt); 2099 2100 return err; 2101 } 2102 2103 static int seg6_local_build_state(struct net *net, struct nlattr *nla, 2104 unsigned int family, const void *cfg, 2105 struct lwtunnel_state **ts, 2106 struct netlink_ext_ack *extack) 2107 { 2108 struct nlattr *tb[SEG6_LOCAL_MAX + 1]; 2109 struct lwtunnel_state *newts; 2110 struct seg6_local_lwt *slwt; 2111 int err; 2112 2113 if (family != AF_INET6) 2114 return -EINVAL; 2115 2116 err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla, 2117 seg6_local_policy, extack); 2118 2119 if (err < 0) 2120 return err; 2121 2122 if (!tb[SEG6_LOCAL_ACTION]) 2123 return -EINVAL; 2124 2125 newts = lwtunnel_state_alloc(sizeof(*slwt)); 2126 if (!newts) 2127 return -ENOMEM; 2128 2129 slwt = seg6_local_lwtunnel(newts); 2130 slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]); 2131 2132 err = parse_nla_action(tb, slwt, extack); 2133 if (err < 0) 2134 goto out_free; 2135 2136 err = seg6_local_lwtunnel_build_state(slwt, cfg, extack); 2137 if (err < 0) 2138 goto out_destroy_attrs; 2139 2140 newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL; 2141 newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT; 2142 newts->headroom = slwt->headroom; 2143 2144 *ts = newts; 2145 2146 return 0; 2147 2148 out_destroy_attrs: 2149 destroy_attrs(slwt); 2150 out_free: 2151 kfree(newts); 2152 return err; 2153 } 2154 2155 static void seg6_local_destroy_state(struct lwtunnel_state *lwt) 2156 { 2157 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2158 2159 seg6_local_lwtunnel_destroy_state(slwt); 2160 2161 destroy_attrs(slwt); 2162 2163 return; 2164 } 2165 2166 static int seg6_local_fill_encap(struct sk_buff *skb, 2167 struct lwtunnel_state *lwt) 2168 { 2169 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2170 struct seg6_action_param *param; 2171 unsigned long attrs; 2172 int i, err; 2173 2174 if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action)) 2175 return -EMSGSIZE; 2176 2177 attrs = slwt->desc->attrs | slwt->parsed_optattrs; 2178 2179 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2180 if (attrs & SEG6_F_ATTR(i)) { 2181 param = &seg6_action_params[i]; 2182 err = param->put(skb, slwt); 2183 if (err < 0) 2184 return err; 2185 } 2186 } 2187 2188 return 0; 2189 } 2190 2191 static int seg6_local_get_encap_size(struct lwtunnel_state *lwt) 2192 { 2193 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2194 unsigned long attrs; 2195 int nlsize; 2196 2197 nlsize = nla_total_size(4); /* action */ 2198 2199 attrs = slwt->desc->attrs | slwt->parsed_optattrs; 2200 2201 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_SRH)) 2202 nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3); 2203 2204 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE)) 2205 nlsize += nla_total_size(4); 2206 2207 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH4)) 2208 nlsize += nla_total_size(4); 2209 2210 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH6)) 2211 nlsize += nla_total_size(16); 2212 2213 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_IIF)) 2214 nlsize += nla_total_size(4); 2215 2216 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_OIF)) 2217 nlsize += nla_total_size(4); 2218 2219 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_BPF)) 2220 nlsize += nla_total_size(sizeof(struct nlattr)) + 2221 nla_total_size(MAX_PROG_NAME) + 2222 nla_total_size(4); 2223 2224 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE)) 2225 nlsize += nla_total_size(4); 2226 2227 if (attrs & SEG6_F_LOCAL_COUNTERS) 2228 nlsize += nla_total_size(0) + /* nest SEG6_LOCAL_COUNTERS */ 2229 /* SEG6_LOCAL_CNT_PACKETS */ 2230 nla_total_size_64bit(sizeof(__u64)) + 2231 /* SEG6_LOCAL_CNT_BYTES */ 2232 nla_total_size_64bit(sizeof(__u64)) + 2233 /* SEG6_LOCAL_CNT_ERRORS */ 2234 nla_total_size_64bit(sizeof(__u64)); 2235 2236 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_FLAVORS)) 2237 nlsize += encap_size_flavors(slwt); 2238 2239 return nlsize; 2240 } 2241 2242 static int seg6_local_cmp_encap(struct lwtunnel_state *a, 2243 struct lwtunnel_state *b) 2244 { 2245 struct seg6_local_lwt *slwt_a, *slwt_b; 2246 struct seg6_action_param *param; 2247 unsigned long attrs_a, attrs_b; 2248 int i; 2249 2250 slwt_a = seg6_local_lwtunnel(a); 2251 slwt_b = seg6_local_lwtunnel(b); 2252 2253 if (slwt_a->action != slwt_b->action) 2254 return 1; 2255 2256 attrs_a = slwt_a->desc->attrs | slwt_a->parsed_optattrs; 2257 attrs_b = slwt_b->desc->attrs | slwt_b->parsed_optattrs; 2258 2259 if (attrs_a != attrs_b) 2260 return 1; 2261 2262 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2263 if (attrs_a & SEG6_F_ATTR(i)) { 2264 param = &seg6_action_params[i]; 2265 if (param->cmp(slwt_a, slwt_b)) 2266 return 1; 2267 } 2268 } 2269 2270 return 0; 2271 } 2272 2273 static const struct lwtunnel_encap_ops seg6_local_ops = { 2274 .build_state = seg6_local_build_state, 2275 .destroy_state = seg6_local_destroy_state, 2276 .input = seg6_local_input, 2277 .fill_encap = seg6_local_fill_encap, 2278 .get_encap_size = seg6_local_get_encap_size, 2279 .cmp_encap = seg6_local_cmp_encap, 2280 .owner = THIS_MODULE, 2281 }; 2282 2283 int __init seg6_local_init(void) 2284 { 2285 /* If the max total number of defined attributes is reached, then your 2286 * kernel build stops here. 2287 * 2288 * This check is required to avoid arithmetic overflows when processing 2289 * behavior attributes and the maximum number of defined attributes 2290 * exceeds the allowed value. 2291 */ 2292 BUILD_BUG_ON(SEG6_LOCAL_MAX + 1 > BITS_PER_TYPE(unsigned long)); 2293 2294 /* If the default NEXT-C-SID Locator-Block/Node Function lengths (in 2295 * bits) have been changed with invalid values, kernel build stops 2296 * here. 2297 */ 2298 BUILD_BUG_ON(next_csid_chk_cntr_bits(SEG6_LOCAL_LCBLOCK_DBITS, 2299 SEG6_LOCAL_LCNODE_FN_DBITS)); 2300 BUILD_BUG_ON(next_csid_chk_lcblock_bits(SEG6_LOCAL_LCBLOCK_DBITS)); 2301 BUILD_BUG_ON(next_csid_chk_lcnode_fn_bits(SEG6_LOCAL_LCNODE_FN_DBITS)); 2302 2303 return lwtunnel_encap_add_ops(&seg6_local_ops, 2304 LWTUNNEL_ENCAP_SEG6_LOCAL); 2305 } 2306 2307 void seg6_local_exit(void) 2308 { 2309 lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL); 2310 } 2311