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 /* flag indicating that flavors are set up for a given End* behavior */ 113 #define SEG6_F_LOCAL_FLAVORS SEG6_F_ATTR(SEG6_LOCAL_FLAVORS) 114 115 #define SEG6_F_LOCAL_FLV_OP(flvname) BIT(SEG6_LOCAL_FLV_OP_##flvname) 116 #define SEG6_F_LOCAL_FLV_NEXT_CSID SEG6_F_LOCAL_FLV_OP(NEXT_CSID) 117 #define SEG6_F_LOCAL_FLV_PSP SEG6_F_LOCAL_FLV_OP(PSP) 118 119 /* Supported RFC8986 Flavor operations are reported in this bitmask */ 120 #define SEG6_LOCAL_FLV8986_SUPP_OPS SEG6_F_LOCAL_FLV_PSP 121 122 #define SEG6_LOCAL_END_FLV_SUPP_OPS (SEG6_F_LOCAL_FLV_NEXT_CSID | \ 123 SEG6_LOCAL_FLV8986_SUPP_OPS) 124 #define SEG6_LOCAL_END_X_FLV_SUPP_OPS SEG6_F_LOCAL_FLV_NEXT_CSID 125 126 struct seg6_flavors_info { 127 /* Flavor operations */ 128 __u32 flv_ops; 129 130 /* Locator-Block length, expressed in bits */ 131 __u8 lcblock_bits; 132 /* Locator-Node Function length, expressed in bits*/ 133 __u8 lcnode_func_bits; 134 }; 135 136 enum seg6_end_dt_mode { 137 DT_INVALID_MODE = -EINVAL, 138 DT_LEGACY_MODE = 0, 139 DT_VRF_MODE = 1, 140 }; 141 142 struct seg6_end_dt_info { 143 enum seg6_end_dt_mode mode; 144 145 struct net *net; 146 /* VRF device associated to the routing table used by the SRv6 147 * End.DT4/DT6 behavior for routing IPv4/IPv6 packets. 148 */ 149 int vrf_ifindex; 150 int vrf_table; 151 152 /* tunneled packet family (IPv4 or IPv6). 153 * Protocol and header length are inferred from family. 154 */ 155 u16 family; 156 }; 157 158 struct pcpu_seg6_local_counters { 159 u64_stats_t packets; 160 u64_stats_t bytes; 161 u64_stats_t errors; 162 163 struct u64_stats_sync syncp; 164 }; 165 166 /* This struct groups all the SRv6 Behavior counters supported so far. 167 * 168 * put_nla_counters() makes use of this data structure to collect all counter 169 * values after the per-CPU counter evaluation has been performed. 170 * Finally, each counter value (in seg6_local_counters) is stored in the 171 * corresponding netlink attribute and sent to user space. 172 * 173 * NB: we don't want to expose this structure to user space! 174 */ 175 struct seg6_local_counters { 176 __u64 packets; 177 __u64 bytes; 178 __u64 errors; 179 }; 180 181 #define seg6_local_alloc_pcpu_counters(__gfp) \ 182 __netdev_alloc_pcpu_stats(struct pcpu_seg6_local_counters, \ 183 ((__gfp) | __GFP_ZERO)) 184 185 #define SEG6_F_LOCAL_COUNTERS SEG6_F_ATTR(SEG6_LOCAL_COUNTERS) 186 187 struct seg6_local_lwt { 188 int action; 189 struct ipv6_sr_hdr *srh; 190 int table; 191 struct in_addr nh4; 192 struct in6_addr nh6; 193 int iif; 194 int oif; 195 struct bpf_lwt_prog bpf; 196 #ifdef CONFIG_NET_L3_MASTER_DEV 197 struct seg6_end_dt_info dt_info; 198 #endif 199 struct seg6_flavors_info flv_info; 200 201 struct pcpu_seg6_local_counters __percpu *pcpu_counters; 202 203 int headroom; 204 struct seg6_action_desc *desc; 205 /* unlike the required attrs, we have to track the optional attributes 206 * that have been effectively parsed. 207 */ 208 unsigned long parsed_optattrs; 209 }; 210 211 static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt) 212 { 213 return (struct seg6_local_lwt *)lwt->data; 214 } 215 216 static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb) 217 { 218 struct ipv6_sr_hdr *srh; 219 220 srh = seg6_get_srh(skb, IP6_FH_F_SKIP_RH); 221 if (!srh) 222 return NULL; 223 224 #ifdef CONFIG_IPV6_SEG6_HMAC 225 if (!seg6_hmac_validate_skb(skb)) 226 return NULL; 227 #endif 228 229 return srh; 230 } 231 232 static bool decap_and_validate(struct sk_buff *skb, int proto) 233 { 234 struct ipv6_sr_hdr *srh; 235 unsigned int off = 0; 236 237 srh = seg6_get_srh(skb, 0); 238 if (srh && srh->segments_left > 0) 239 return false; 240 241 #ifdef CONFIG_IPV6_SEG6_HMAC 242 if (srh && !seg6_hmac_validate_skb(skb)) 243 return false; 244 #endif 245 246 if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0) 247 return false; 248 249 if (!pskb_pull(skb, off)) 250 return false; 251 252 skb_postpull_rcsum(skb, skb_network_header(skb), off); 253 254 skb_reset_network_header(skb); 255 skb_reset_transport_header(skb); 256 if (iptunnel_pull_offloads(skb)) 257 return false; 258 259 return true; 260 } 261 262 static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr) 263 { 264 struct in6_addr *addr; 265 266 srh->segments_left--; 267 addr = srh->segments + srh->segments_left; 268 *daddr = *addr; 269 } 270 271 static int 272 seg6_lookup_any_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, 273 u32 tbl_id, bool local_delivery) 274 { 275 struct net *net = dev_net(skb->dev); 276 struct ipv6hdr *hdr = ipv6_hdr(skb); 277 int flags = RT6_LOOKUP_F_HAS_SADDR; 278 struct dst_entry *dst = NULL; 279 struct rt6_info *rt; 280 struct flowi6 fl6; 281 int dev_flags = 0; 282 283 memset(&fl6, 0, sizeof(fl6)); 284 fl6.flowi6_iif = skb->dev->ifindex; 285 fl6.daddr = nhaddr ? *nhaddr : hdr->daddr; 286 fl6.saddr = hdr->saddr; 287 fl6.flowlabel = ip6_flowinfo(hdr); 288 fl6.flowi6_mark = skb->mark; 289 fl6.flowi6_proto = hdr->nexthdr; 290 291 if (nhaddr) 292 fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH; 293 294 if (!tbl_id) { 295 dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags); 296 } else { 297 struct fib6_table *table; 298 299 table = fib6_get_table(net, tbl_id); 300 if (!table) 301 goto out; 302 303 rt = ip6_pol_route(net, table, 0, &fl6, skb, flags); 304 dst = &rt->dst; 305 } 306 307 /* we want to discard traffic destined for local packet processing, 308 * if @local_delivery is set to false. 309 */ 310 if (!local_delivery) 311 dev_flags |= IFF_LOOPBACK; 312 313 if (dst && (dst->dev->flags & dev_flags) && !dst->error) { 314 dst_release(dst); 315 dst = NULL; 316 } 317 318 out: 319 if (!dst) { 320 rt = net->ipv6.ip6_blk_hole_entry; 321 dst = &rt->dst; 322 dst_hold(dst); 323 } 324 325 skb_dst_drop(skb); 326 skb_dst_set(skb, dst); 327 return dst->error; 328 } 329 330 int seg6_lookup_nexthop(struct sk_buff *skb, 331 struct in6_addr *nhaddr, u32 tbl_id) 332 { 333 return seg6_lookup_any_nexthop(skb, nhaddr, tbl_id, false); 334 } 335 336 static __u8 seg6_flv_lcblock_octects(const struct seg6_flavors_info *finfo) 337 { 338 return finfo->lcblock_bits >> 3; 339 } 340 341 static __u8 seg6_flv_lcnode_func_octects(const struct seg6_flavors_info *finfo) 342 { 343 return finfo->lcnode_func_bits >> 3; 344 } 345 346 static bool seg6_next_csid_is_arg_zero(const struct in6_addr *addr, 347 const struct seg6_flavors_info *finfo) 348 { 349 __u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo); 350 __u8 blk_octects = seg6_flv_lcblock_octects(finfo); 351 __u8 arg_octects; 352 int i; 353 354 arg_octects = 16 - blk_octects - fnc_octects; 355 for (i = 0; i < arg_octects; ++i) { 356 if (addr->s6_addr[blk_octects + fnc_octects + i] != 0x00) 357 return false; 358 } 359 360 return true; 361 } 362 363 /* assume that DA.Argument length > 0 */ 364 static void seg6_next_csid_advance_arg(struct in6_addr *addr, 365 const struct seg6_flavors_info *finfo) 366 { 367 __u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo); 368 __u8 blk_octects = seg6_flv_lcblock_octects(finfo); 369 370 /* advance DA.Argument */ 371 memmove(&addr->s6_addr[blk_octects], 372 &addr->s6_addr[blk_octects + fnc_octects], 373 16 - blk_octects - fnc_octects); 374 375 memset(&addr->s6_addr[16 - fnc_octects], 0x00, fnc_octects); 376 } 377 378 static int input_action_end_finish(struct sk_buff *skb, 379 struct seg6_local_lwt *slwt) 380 { 381 seg6_lookup_nexthop(skb, NULL, 0); 382 383 return dst_input(skb); 384 } 385 386 static int input_action_end_core(struct sk_buff *skb, 387 struct seg6_local_lwt *slwt) 388 { 389 struct ipv6_sr_hdr *srh; 390 391 srh = get_and_validate_srh(skb); 392 if (!srh) 393 goto drop; 394 395 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 396 397 return input_action_end_finish(skb, slwt); 398 399 drop: 400 kfree_skb(skb); 401 return -EINVAL; 402 } 403 404 static int end_next_csid_core(struct sk_buff *skb, struct seg6_local_lwt *slwt) 405 { 406 const struct seg6_flavors_info *finfo = &slwt->flv_info; 407 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 408 409 if (seg6_next_csid_is_arg_zero(daddr, finfo)) 410 return input_action_end_core(skb, slwt); 411 412 /* update DA */ 413 seg6_next_csid_advance_arg(daddr, finfo); 414 415 return input_action_end_finish(skb, slwt); 416 } 417 418 static int input_action_end_x_finish(struct sk_buff *skb, 419 struct seg6_local_lwt *slwt) 420 { 421 seg6_lookup_nexthop(skb, &slwt->nh6, 0); 422 423 return dst_input(skb); 424 } 425 426 static int input_action_end_x_core(struct sk_buff *skb, 427 struct seg6_local_lwt *slwt) 428 { 429 struct ipv6_sr_hdr *srh; 430 431 srh = get_and_validate_srh(skb); 432 if (!srh) 433 goto drop; 434 435 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 436 437 return input_action_end_x_finish(skb, slwt); 438 439 drop: 440 kfree_skb(skb); 441 return -EINVAL; 442 } 443 444 static int end_x_next_csid_core(struct sk_buff *skb, 445 struct seg6_local_lwt *slwt) 446 { 447 const struct seg6_flavors_info *finfo = &slwt->flv_info; 448 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 449 450 if (seg6_next_csid_is_arg_zero(daddr, finfo)) 451 return input_action_end_x_core(skb, slwt); 452 453 /* update DA */ 454 seg6_next_csid_advance_arg(daddr, finfo); 455 456 return input_action_end_x_finish(skb, slwt); 457 } 458 459 static bool seg6_next_csid_enabled(__u32 fops) 460 { 461 return fops & SEG6_F_LOCAL_FLV_NEXT_CSID; 462 } 463 464 /* Processing of SRv6 End, End.X, and End.T behaviors can be extended through 465 * the flavors framework. These behaviors must report the subset of (flavor) 466 * operations they currently implement. In this way, if a user specifies a 467 * flavor combination that is not supported by a given End* behavior, the 468 * kernel refuses to instantiate the tunnel reporting the error. 469 */ 470 static int seg6_flv_supp_ops_by_action(int action, __u32 *fops) 471 { 472 switch (action) { 473 case SEG6_LOCAL_ACTION_END: 474 *fops = SEG6_LOCAL_END_FLV_SUPP_OPS; 475 break; 476 case SEG6_LOCAL_ACTION_END_X: 477 *fops = SEG6_LOCAL_END_X_FLV_SUPP_OPS; 478 break; 479 default: 480 return -EOPNOTSUPP; 481 } 482 483 return 0; 484 } 485 486 /* We describe the packet state in relation to the absence/presence of the SRH 487 * and the Segment Left (SL) field. 488 * For our purposes, it is not necessary to record the exact value of the SL 489 * when the SID List consists of two or more segments. 490 */ 491 enum seg6_local_pktinfo { 492 /* the order really matters! */ 493 SEG6_LOCAL_PKTINFO_NOHDR = 0, 494 SEG6_LOCAL_PKTINFO_SL_ZERO, 495 SEG6_LOCAL_PKTINFO_SL_ONE, 496 SEG6_LOCAL_PKTINFO_SL_MORE, 497 __SEG6_LOCAL_PKTINFO_MAX, 498 }; 499 500 #define SEG6_LOCAL_PKTINFO_MAX (__SEG6_LOCAL_PKTINFO_MAX - 1) 501 502 static enum seg6_local_pktinfo seg6_get_srh_pktinfo(struct ipv6_sr_hdr *srh) 503 { 504 __u8 sgl; 505 506 if (!srh) 507 return SEG6_LOCAL_PKTINFO_NOHDR; 508 509 sgl = srh->segments_left; 510 if (sgl < 2) 511 return SEG6_LOCAL_PKTINFO_SL_ZERO + sgl; 512 513 return SEG6_LOCAL_PKTINFO_SL_MORE; 514 } 515 516 enum seg6_local_flv_action { 517 SEG6_LOCAL_FLV_ACT_UNSPEC = 0, 518 SEG6_LOCAL_FLV_ACT_END, 519 SEG6_LOCAL_FLV_ACT_PSP, 520 SEG6_LOCAL_FLV_ACT_USP, 521 SEG6_LOCAL_FLV_ACT_USD, 522 __SEG6_LOCAL_FLV_ACT_MAX 523 }; 524 525 #define SEG6_LOCAL_FLV_ACT_MAX (__SEG6_LOCAL_FLV_ACT_MAX - 1) 526 527 /* The action table for RFC8986 flavors (see the flv8986_act_tbl below) 528 * contains the actions (i.e. processing operations) to be applied on packets 529 * when flavors are configured for an End* behavior. 530 * By combining the pkinfo data and from the flavors mask, the macro 531 * computes the index used to access the elements (actions) stored in the 532 * action table. The index is structured as follows: 533 * 534 * index 535 * _______________/\________________ 536 * / \ 537 * +----------------+----------------+ 538 * | pf | afm | 539 * +----------------+----------------+ 540 * ph-1 ... p1 p0 fk-1 ... f1 f0 541 * MSB LSB 542 * 543 * where: 544 * - 'afm' (adjusted flavor mask) is the mask containing a combination of the 545 * RFC8986 flavors currently supported. 'afm' corresponds to the @fm 546 * argument of the macro whose value is righ-shifted by 1 bit. By doing so, 547 * we discard the SEG6_LOCAL_FLV_OP_UNSPEC flag (bit 0 in @fm) which is 548 * never used here; 549 * - 'pf' encodes the packet info (pktinfo) regarding the presence/absence of 550 * the SRH, SL = 0, etc. 'pf' is set with the value of @pf provided as 551 * argument to the macro. 552 */ 553 #define flv8986_act_tbl_idx(pf, fm) \ 554 ((((pf) << bits_per(SEG6_LOCAL_FLV8986_SUPP_OPS)) | \ 555 ((fm) & SEG6_LOCAL_FLV8986_SUPP_OPS)) >> SEG6_LOCAL_FLV_OP_PSP) 556 557 /* We compute the size of the action table by considering the RFC8986 flavors 558 * actually supported by the kernel. In this way, the size is automatically 559 * adjusted when new flavors are supported. 560 */ 561 #define FLV8986_ACT_TBL_SIZE \ 562 roundup_pow_of_two(flv8986_act_tbl_idx(SEG6_LOCAL_PKTINFO_MAX, \ 563 SEG6_LOCAL_FLV8986_SUPP_OPS)) 564 565 /* tbl_cfg(act, pf, fm) macro is used to easily configure the action 566 * table; it accepts 3 arguments: 567 * i) @act, the suffix from SEG6_LOCAL_FLV_ACT_{act} representing 568 * the action that should be applied on the packet; 569 * ii) @pf, the suffix from SEG6_LOCAL_PKTINFO_{pf} reporting the packet 570 * info about the lack/presence of SRH, SRH with SL = 0, etc; 571 * iii) @fm, the mask of flavors. 572 */ 573 #define tbl_cfg(act, pf, fm) \ 574 [flv8986_act_tbl_idx(SEG6_LOCAL_PKTINFO_##pf, \ 575 (fm))] = SEG6_LOCAL_FLV_ACT_##act 576 577 /* shorthand for improving readability */ 578 #define F_PSP SEG6_F_LOCAL_FLV_PSP 579 580 /* The table contains, for each combination of the pktinfo data and 581 * flavors, the action that should be taken on a packet (e.g. 582 * "standard" Endpoint processing, Penultimate Segment Pop, etc). 583 * 584 * By default, table entries not explicitly configured are initialized with the 585 * SEG6_LOCAL_FLV_ACT_UNSPEC action, which generally has the effect of 586 * discarding the processed packet. 587 */ 588 static const u8 flv8986_act_tbl[FLV8986_ACT_TBL_SIZE] = { 589 /* PSP variant for packet where SRH with SL = 1 */ 590 tbl_cfg(PSP, SL_ONE, F_PSP), 591 /* End for packet where the SRH with SL > 1*/ 592 tbl_cfg(END, SL_MORE, F_PSP), 593 }; 594 595 #undef F_PSP 596 #undef tbl_cfg 597 598 /* For each flavor defined in RFC8986 (or a combination of them) an action is 599 * performed on the packet. The specific action depends on: 600 * - info extracted from the packet (i.e. pktinfo data) regarding the 601 * lack/presence of the SRH, and if the SRH is available, on the value of 602 * Segment Left field; 603 * - the mask of flavors configured for the specific SRv6 End* behavior. 604 * 605 * The function combines both the pkinfo and the flavors mask to evaluate the 606 * corresponding action to be taken on the packet. 607 */ 608 static enum seg6_local_flv_action 609 seg6_local_flv8986_act_lookup(enum seg6_local_pktinfo pinfo, __u32 flvmask) 610 { 611 unsigned long index; 612 613 /* check if the provided mask of flavors is supported */ 614 if (unlikely(flvmask & ~SEG6_LOCAL_FLV8986_SUPP_OPS)) 615 return SEG6_LOCAL_FLV_ACT_UNSPEC; 616 617 index = flv8986_act_tbl_idx(pinfo, flvmask); 618 if (unlikely(index >= FLV8986_ACT_TBL_SIZE)) 619 return SEG6_LOCAL_FLV_ACT_UNSPEC; 620 621 return flv8986_act_tbl[index]; 622 } 623 624 /* skb->data must be aligned with skb->network_header */ 625 static bool seg6_pop_srh(struct sk_buff *skb, int srhoff) 626 { 627 struct ipv6_sr_hdr *srh; 628 struct ipv6hdr *iph; 629 __u8 srh_nexthdr; 630 int thoff = -1; 631 int srhlen; 632 int nhlen; 633 634 if (unlikely(srhoff < sizeof(*iph) || 635 !pskb_may_pull(skb, srhoff + sizeof(*srh)))) 636 return false; 637 638 srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); 639 srhlen = ipv6_optlen(srh); 640 641 /* we are about to mangle the pkt, let's check if we can write on it */ 642 if (unlikely(skb_ensure_writable(skb, srhoff + srhlen))) 643 return false; 644 645 /* skb_ensure_writable() may change skb pointers; evaluate srh again */ 646 srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); 647 srh_nexthdr = srh->nexthdr; 648 649 if (unlikely(!skb_transport_header_was_set(skb))) 650 goto pull; 651 652 nhlen = skb_network_header_len(skb); 653 /* we have to deal with the transport header: it could be set before 654 * the SRH, after the SRH, or within it (which is considered wrong, 655 * however). 656 */ 657 if (likely(nhlen <= srhoff)) 658 thoff = nhlen; 659 else if (nhlen >= srhoff + srhlen) 660 /* transport_header is set after the SRH */ 661 thoff = nhlen - srhlen; 662 else 663 /* transport_header falls inside the SRH; hence, we can't 664 * restore the transport_header pointer properly after 665 * SRH removing operation. 666 */ 667 return false; 668 pull: 669 /* we need to pop the SRH: 670 * 1) first of all, we pull out everything from IPv6 header up to SRH 671 * (included) evaluating also the rcsum; 672 * 2) we overwrite (and then remove) the SRH by properly moving the 673 * IPv6 along with any extension header that precedes the SRH; 674 * 3) At the end, we push back the pulled headers (except for SRH, 675 * obviously). 676 */ 677 skb_pull_rcsum(skb, srhoff + srhlen); 678 memmove(skb_network_header(skb) + srhlen, skb_network_header(skb), 679 srhoff); 680 skb_push(skb, srhoff); 681 682 skb_reset_network_header(skb); 683 skb_mac_header_rebuild(skb); 684 if (likely(thoff >= 0)) 685 skb_set_transport_header(skb, thoff); 686 687 iph = ipv6_hdr(skb); 688 if (iph->nexthdr == NEXTHDR_ROUTING) { 689 iph->nexthdr = srh_nexthdr; 690 } else { 691 /* we must look for the extension header (EXTH, for short) that 692 * immediately precedes the SRH we have just removed. 693 * Then, we update the value of the EXTH nexthdr with the one 694 * contained in the SRH nexthdr. 695 */ 696 unsigned int off = sizeof(*iph); 697 struct ipv6_opt_hdr *hp, _hdr; 698 __u8 nexthdr = iph->nexthdr; 699 700 for (;;) { 701 if (unlikely(!ipv6_ext_hdr(nexthdr) || 702 nexthdr == NEXTHDR_NONE)) 703 return false; 704 705 hp = skb_header_pointer(skb, off, sizeof(_hdr), &_hdr); 706 if (unlikely(!hp)) 707 return false; 708 709 if (hp->nexthdr == NEXTHDR_ROUTING) { 710 hp->nexthdr = srh_nexthdr; 711 break; 712 } 713 714 switch (nexthdr) { 715 case NEXTHDR_FRAGMENT: 716 fallthrough; 717 case NEXTHDR_AUTH: 718 /* we expect SRH before FRAG and AUTH */ 719 return false; 720 default: 721 off += ipv6_optlen(hp); 722 break; 723 } 724 725 nexthdr = hp->nexthdr; 726 } 727 } 728 729 iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 730 731 skb_postpush_rcsum(skb, iph, srhoff); 732 733 return true; 734 } 735 736 /* process the packet on the basis of the RFC8986 flavors set for the given 737 * SRv6 End behavior instance. 738 */ 739 static int end_flv8986_core(struct sk_buff *skb, struct seg6_local_lwt *slwt) 740 { 741 const struct seg6_flavors_info *finfo = &slwt->flv_info; 742 enum seg6_local_flv_action action; 743 enum seg6_local_pktinfo pinfo; 744 struct ipv6_sr_hdr *srh; 745 __u32 flvmask; 746 int srhoff; 747 748 srh = seg6_get_srh(skb, 0); 749 srhoff = srh ? ((unsigned char *)srh - skb->data) : 0; 750 pinfo = seg6_get_srh_pktinfo(srh); 751 #ifdef CONFIG_IPV6_SEG6_HMAC 752 if (srh && !seg6_hmac_validate_skb(skb)) 753 goto drop; 754 #endif 755 flvmask = finfo->flv_ops; 756 if (unlikely(flvmask & ~SEG6_LOCAL_FLV8986_SUPP_OPS)) { 757 pr_warn_once("seg6local: invalid RFC8986 flavors\n"); 758 goto drop; 759 } 760 761 /* retrieve the action triggered by the combination of pktinfo data and 762 * the flavors mask. 763 */ 764 action = seg6_local_flv8986_act_lookup(pinfo, flvmask); 765 switch (action) { 766 case SEG6_LOCAL_FLV_ACT_END: 767 /* process the packet as the "standard" End behavior */ 768 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 769 break; 770 case SEG6_LOCAL_FLV_ACT_PSP: 771 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 772 773 if (unlikely(!seg6_pop_srh(skb, srhoff))) 774 goto drop; 775 break; 776 case SEG6_LOCAL_FLV_ACT_UNSPEC: 777 fallthrough; 778 default: 779 /* by default, we drop the packet since we could not find a 780 * suitable action. 781 */ 782 goto drop; 783 } 784 785 return input_action_end_finish(skb, slwt); 786 787 drop: 788 kfree_skb(skb); 789 return -EINVAL; 790 } 791 792 /* regular endpoint function */ 793 static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt) 794 { 795 const struct seg6_flavors_info *finfo = &slwt->flv_info; 796 __u32 fops = finfo->flv_ops; 797 798 if (!fops) 799 return input_action_end_core(skb, slwt); 800 801 /* check for the presence of NEXT-C-SID since it applies first */ 802 if (seg6_next_csid_enabled(fops)) 803 return end_next_csid_core(skb, slwt); 804 805 /* the specific processing function to be performed on the packet 806 * depends on the combination of flavors defined in RFC8986 and some 807 * information extracted from the packet, e.g. presence/absence of SRH, 808 * Segment Left = 0, etc. 809 */ 810 return end_flv8986_core(skb, slwt); 811 } 812 813 /* regular endpoint, and forward to specified nexthop */ 814 static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt) 815 { 816 const struct seg6_flavors_info *finfo = &slwt->flv_info; 817 __u32 fops = finfo->flv_ops; 818 819 /* check for the presence of NEXT-C-SID since it applies first */ 820 if (seg6_next_csid_enabled(fops)) 821 return end_x_next_csid_core(skb, slwt); 822 823 return input_action_end_x_core(skb, slwt); 824 } 825 826 static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt) 827 { 828 struct ipv6_sr_hdr *srh; 829 830 srh = get_and_validate_srh(skb); 831 if (!srh) 832 goto drop; 833 834 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 835 836 seg6_lookup_nexthop(skb, NULL, slwt->table); 837 838 return dst_input(skb); 839 840 drop: 841 kfree_skb(skb); 842 return -EINVAL; 843 } 844 845 /* decapsulate and forward inner L2 frame on specified interface */ 846 static int input_action_end_dx2(struct sk_buff *skb, 847 struct seg6_local_lwt *slwt) 848 { 849 struct net *net = dev_net(skb->dev); 850 struct net_device *odev; 851 struct ethhdr *eth; 852 853 if (!decap_and_validate(skb, IPPROTO_ETHERNET)) 854 goto drop; 855 856 if (!pskb_may_pull(skb, ETH_HLEN)) 857 goto drop; 858 859 skb_reset_mac_header(skb); 860 eth = (struct ethhdr *)skb->data; 861 862 /* To determine the frame's protocol, we assume it is 802.3. This avoids 863 * a call to eth_type_trans(), which is not really relevant for our 864 * use case. 865 */ 866 if (!eth_proto_is_802_3(eth->h_proto)) 867 goto drop; 868 869 odev = dev_get_by_index_rcu(net, slwt->oif); 870 if (!odev) 871 goto drop; 872 873 /* As we accept Ethernet frames, make sure the egress device is of 874 * the correct type. 875 */ 876 if (odev->type != ARPHRD_ETHER) 877 goto drop; 878 879 if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev)) 880 goto drop; 881 882 skb_orphan(skb); 883 884 if (skb_warn_if_lro(skb)) 885 goto drop; 886 887 skb_forward_csum(skb); 888 889 if (skb->len - ETH_HLEN > odev->mtu) 890 goto drop; 891 892 skb->dev = odev; 893 skb->protocol = eth->h_proto; 894 895 return dev_queue_xmit(skb); 896 897 drop: 898 kfree_skb(skb); 899 return -EINVAL; 900 } 901 902 static int input_action_end_dx6_finish(struct net *net, struct sock *sk, 903 struct sk_buff *skb) 904 { 905 struct dst_entry *orig_dst = skb_dst(skb); 906 struct in6_addr *nhaddr = NULL; 907 struct seg6_local_lwt *slwt; 908 909 slwt = seg6_local_lwtunnel(orig_dst->lwtstate); 910 911 /* The inner packet is not associated to any local interface, 912 * so we do not call netif_rx(). 913 * 914 * If slwt->nh6 is set to ::, then lookup the nexthop for the 915 * inner packet's DA. Otherwise, use the specified nexthop. 916 */ 917 if (!ipv6_addr_any(&slwt->nh6)) 918 nhaddr = &slwt->nh6; 919 920 seg6_lookup_nexthop(skb, nhaddr, 0); 921 922 return dst_input(skb); 923 } 924 925 /* decapsulate and forward to specified nexthop */ 926 static int input_action_end_dx6(struct sk_buff *skb, 927 struct seg6_local_lwt *slwt) 928 { 929 /* this function accepts IPv6 encapsulated packets, with either 930 * an SRH with SL=0, or no SRH. 931 */ 932 933 if (!decap_and_validate(skb, IPPROTO_IPV6)) 934 goto drop; 935 936 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 937 goto drop; 938 939 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 940 nf_reset_ct(skb); 941 942 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) 943 return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, 944 dev_net(skb->dev), NULL, skb, NULL, 945 skb_dst(skb)->dev, input_action_end_dx6_finish); 946 947 return input_action_end_dx6_finish(dev_net(skb->dev), NULL, skb); 948 drop: 949 kfree_skb(skb); 950 return -EINVAL; 951 } 952 953 static int input_action_end_dx4_finish(struct net *net, struct sock *sk, 954 struct sk_buff *skb) 955 { 956 struct dst_entry *orig_dst = skb_dst(skb); 957 struct seg6_local_lwt *slwt; 958 struct iphdr *iph; 959 __be32 nhaddr; 960 int err; 961 962 slwt = seg6_local_lwtunnel(orig_dst->lwtstate); 963 964 iph = ip_hdr(skb); 965 966 nhaddr = slwt->nh4.s_addr ?: iph->daddr; 967 968 skb_dst_drop(skb); 969 970 err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev); 971 if (err) { 972 kfree_skb(skb); 973 return -EINVAL; 974 } 975 976 return dst_input(skb); 977 } 978 979 static int input_action_end_dx4(struct sk_buff *skb, 980 struct seg6_local_lwt *slwt) 981 { 982 if (!decap_and_validate(skb, IPPROTO_IPIP)) 983 goto drop; 984 985 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 986 goto drop; 987 988 skb->protocol = htons(ETH_P_IP); 989 skb_set_transport_header(skb, sizeof(struct iphdr)); 990 nf_reset_ct(skb); 991 992 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) 993 return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, 994 dev_net(skb->dev), NULL, skb, NULL, 995 skb_dst(skb)->dev, input_action_end_dx4_finish); 996 997 return input_action_end_dx4_finish(dev_net(skb->dev), NULL, skb); 998 drop: 999 kfree_skb(skb); 1000 return -EINVAL; 1001 } 1002 1003 #ifdef CONFIG_NET_L3_MASTER_DEV 1004 static struct net *fib6_config_get_net(const struct fib6_config *fib6_cfg) 1005 { 1006 const struct nl_info *nli = &fib6_cfg->fc_nlinfo; 1007 1008 return nli->nl_net; 1009 } 1010 1011 static int __seg6_end_dt_vrf_build(struct seg6_local_lwt *slwt, const void *cfg, 1012 u16 family, struct netlink_ext_ack *extack) 1013 { 1014 struct seg6_end_dt_info *info = &slwt->dt_info; 1015 int vrf_ifindex; 1016 struct net *net; 1017 1018 net = fib6_config_get_net(cfg); 1019 1020 /* note that vrf_table was already set by parse_nla_vrftable() */ 1021 vrf_ifindex = l3mdev_ifindex_lookup_by_table_id(L3MDEV_TYPE_VRF, net, 1022 info->vrf_table); 1023 if (vrf_ifindex < 0) { 1024 if (vrf_ifindex == -EPERM) { 1025 NL_SET_ERR_MSG(extack, 1026 "Strict mode for VRF is disabled"); 1027 } else if (vrf_ifindex == -ENODEV) { 1028 NL_SET_ERR_MSG(extack, 1029 "Table has no associated VRF device"); 1030 } else { 1031 pr_debug("seg6local: SRv6 End.DT* creation error=%d\n", 1032 vrf_ifindex); 1033 } 1034 1035 return vrf_ifindex; 1036 } 1037 1038 info->net = net; 1039 info->vrf_ifindex = vrf_ifindex; 1040 1041 info->family = family; 1042 info->mode = DT_VRF_MODE; 1043 1044 return 0; 1045 } 1046 1047 /* The SRv6 End.DT4/DT6 behavior extracts the inner (IPv4/IPv6) packet and 1048 * routes the IPv4/IPv6 packet by looking at the configured routing table. 1049 * 1050 * In the SRv6 End.DT4/DT6 use case, we can receive traffic (IPv6+Segment 1051 * Routing Header packets) from several interfaces and the outer IPv6 1052 * destination address (DA) is used for retrieving the specific instance of the 1053 * End.DT4/DT6 behavior that should process the packets. 1054 * 1055 * However, the inner IPv4/IPv6 packet is not really bound to any receiving 1056 * interface and thus the End.DT4/DT6 sets the VRF (associated with the 1057 * corresponding routing table) as the *receiving* interface. 1058 * In other words, the End.DT4/DT6 processes a packet as if it has been received 1059 * directly by the VRF (and not by one of its slave devices, if any). 1060 * In this way, the VRF interface is used for routing the IPv4/IPv6 packet in 1061 * according to the routing table configured by the End.DT4/DT6 instance. 1062 * 1063 * This design allows you to get some interesting features like: 1064 * 1) the statistics on rx packets; 1065 * 2) the possibility to install a packet sniffer on the receiving interface 1066 * (the VRF one) for looking at the incoming packets; 1067 * 3) the possibility to leverage the netfilter prerouting hook for the inner 1068 * IPv4 packet. 1069 * 1070 * This function returns: 1071 * - the sk_buff* when the VRF rcv handler has processed the packet correctly; 1072 * - NULL when the skb is consumed by the VRF rcv handler; 1073 * - a pointer which encodes a negative error number in case of error. 1074 * Note that in this case, the function takes care of freeing the skb. 1075 */ 1076 static struct sk_buff *end_dt_vrf_rcv(struct sk_buff *skb, u16 family, 1077 struct net_device *dev) 1078 { 1079 /* based on l3mdev_ip_rcv; we are only interested in the master */ 1080 if (unlikely(!netif_is_l3_master(dev) && !netif_has_l3_rx_handler(dev))) 1081 goto drop; 1082 1083 if (unlikely(!dev->l3mdev_ops->l3mdev_l3_rcv)) 1084 goto drop; 1085 1086 /* the decap packet IPv4/IPv6 does not come with any mac header info. 1087 * We must unset the mac header to allow the VRF device to rebuild it, 1088 * just in case there is a sniffer attached on the device. 1089 */ 1090 skb_unset_mac_header(skb); 1091 1092 skb = dev->l3mdev_ops->l3mdev_l3_rcv(dev, skb, family); 1093 if (!skb) 1094 /* the skb buffer was consumed by the handler */ 1095 return NULL; 1096 1097 /* when a packet is received by a VRF or by one of its slaves, the 1098 * master device reference is set into the skb. 1099 */ 1100 if (unlikely(skb->dev != dev || skb->skb_iif != dev->ifindex)) 1101 goto drop; 1102 1103 return skb; 1104 1105 drop: 1106 kfree_skb(skb); 1107 return ERR_PTR(-EINVAL); 1108 } 1109 1110 static struct net_device *end_dt_get_vrf_rcu(struct sk_buff *skb, 1111 struct seg6_end_dt_info *info) 1112 { 1113 int vrf_ifindex = info->vrf_ifindex; 1114 struct net *net = info->net; 1115 1116 if (unlikely(vrf_ifindex < 0)) 1117 goto error; 1118 1119 if (unlikely(!net_eq(dev_net(skb->dev), net))) 1120 goto error; 1121 1122 return dev_get_by_index_rcu(net, vrf_ifindex); 1123 1124 error: 1125 return NULL; 1126 } 1127 1128 static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb, 1129 struct seg6_local_lwt *slwt, u16 family) 1130 { 1131 struct seg6_end_dt_info *info = &slwt->dt_info; 1132 struct net_device *vrf; 1133 __be16 protocol; 1134 int hdrlen; 1135 1136 vrf = end_dt_get_vrf_rcu(skb, info); 1137 if (unlikely(!vrf)) 1138 goto drop; 1139 1140 switch (family) { 1141 case AF_INET: 1142 protocol = htons(ETH_P_IP); 1143 hdrlen = sizeof(struct iphdr); 1144 break; 1145 case AF_INET6: 1146 protocol = htons(ETH_P_IPV6); 1147 hdrlen = sizeof(struct ipv6hdr); 1148 break; 1149 case AF_UNSPEC: 1150 fallthrough; 1151 default: 1152 goto drop; 1153 } 1154 1155 if (unlikely(info->family != AF_UNSPEC && info->family != family)) { 1156 pr_warn_once("seg6local: SRv6 End.DT* family mismatch"); 1157 goto drop; 1158 } 1159 1160 skb->protocol = protocol; 1161 1162 skb_dst_drop(skb); 1163 1164 skb_set_transport_header(skb, hdrlen); 1165 nf_reset_ct(skb); 1166 1167 return end_dt_vrf_rcv(skb, family, vrf); 1168 1169 drop: 1170 kfree_skb(skb); 1171 return ERR_PTR(-EINVAL); 1172 } 1173 1174 static int input_action_end_dt4(struct sk_buff *skb, 1175 struct seg6_local_lwt *slwt) 1176 { 1177 struct iphdr *iph; 1178 int err; 1179 1180 if (!decap_and_validate(skb, IPPROTO_IPIP)) 1181 goto drop; 1182 1183 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 1184 goto drop; 1185 1186 skb = end_dt_vrf_core(skb, slwt, AF_INET); 1187 if (!skb) 1188 /* packet has been processed and consumed by the VRF */ 1189 return 0; 1190 1191 if (IS_ERR(skb)) 1192 return PTR_ERR(skb); 1193 1194 iph = ip_hdr(skb); 1195 1196 err = ip_route_input(skb, iph->daddr, iph->saddr, 0, skb->dev); 1197 if (unlikely(err)) 1198 goto drop; 1199 1200 return dst_input(skb); 1201 1202 drop: 1203 kfree_skb(skb); 1204 return -EINVAL; 1205 } 1206 1207 static int seg6_end_dt4_build(struct seg6_local_lwt *slwt, const void *cfg, 1208 struct netlink_ext_ack *extack) 1209 { 1210 return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET, extack); 1211 } 1212 1213 static enum 1214 seg6_end_dt_mode seg6_end_dt6_parse_mode(struct seg6_local_lwt *slwt) 1215 { 1216 unsigned long parsed_optattrs = slwt->parsed_optattrs; 1217 bool legacy, vrfmode; 1218 1219 legacy = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE)); 1220 vrfmode = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE)); 1221 1222 if (!(legacy ^ vrfmode)) 1223 /* both are absent or present: invalid DT6 mode */ 1224 return DT_INVALID_MODE; 1225 1226 return legacy ? DT_LEGACY_MODE : DT_VRF_MODE; 1227 } 1228 1229 static enum seg6_end_dt_mode seg6_end_dt6_get_mode(struct seg6_local_lwt *slwt) 1230 { 1231 struct seg6_end_dt_info *info = &slwt->dt_info; 1232 1233 return info->mode; 1234 } 1235 1236 static int seg6_end_dt6_build(struct seg6_local_lwt *slwt, const void *cfg, 1237 struct netlink_ext_ack *extack) 1238 { 1239 enum seg6_end_dt_mode mode = seg6_end_dt6_parse_mode(slwt); 1240 struct seg6_end_dt_info *info = &slwt->dt_info; 1241 1242 switch (mode) { 1243 case DT_LEGACY_MODE: 1244 info->mode = DT_LEGACY_MODE; 1245 return 0; 1246 case DT_VRF_MODE: 1247 return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET6, extack); 1248 default: 1249 NL_SET_ERR_MSG(extack, "table or vrftable must be specified"); 1250 return -EINVAL; 1251 } 1252 } 1253 #endif 1254 1255 static int input_action_end_dt6(struct sk_buff *skb, 1256 struct seg6_local_lwt *slwt) 1257 { 1258 if (!decap_and_validate(skb, IPPROTO_IPV6)) 1259 goto drop; 1260 1261 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 1262 goto drop; 1263 1264 #ifdef CONFIG_NET_L3_MASTER_DEV 1265 if (seg6_end_dt6_get_mode(slwt) == DT_LEGACY_MODE) 1266 goto legacy_mode; 1267 1268 /* DT6_VRF_MODE */ 1269 skb = end_dt_vrf_core(skb, slwt, AF_INET6); 1270 if (!skb) 1271 /* packet has been processed and consumed by the VRF */ 1272 return 0; 1273 1274 if (IS_ERR(skb)) 1275 return PTR_ERR(skb); 1276 1277 /* note: this time we do not need to specify the table because the VRF 1278 * takes care of selecting the correct table. 1279 */ 1280 seg6_lookup_any_nexthop(skb, NULL, 0, true); 1281 1282 return dst_input(skb); 1283 1284 legacy_mode: 1285 #endif 1286 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 1287 1288 seg6_lookup_any_nexthop(skb, NULL, slwt->table, true); 1289 1290 return dst_input(skb); 1291 1292 drop: 1293 kfree_skb(skb); 1294 return -EINVAL; 1295 } 1296 1297 #ifdef CONFIG_NET_L3_MASTER_DEV 1298 static int seg6_end_dt46_build(struct seg6_local_lwt *slwt, const void *cfg, 1299 struct netlink_ext_ack *extack) 1300 { 1301 return __seg6_end_dt_vrf_build(slwt, cfg, AF_UNSPEC, extack); 1302 } 1303 1304 static int input_action_end_dt46(struct sk_buff *skb, 1305 struct seg6_local_lwt *slwt) 1306 { 1307 unsigned int off = 0; 1308 int nexthdr; 1309 1310 nexthdr = ipv6_find_hdr(skb, &off, -1, NULL, NULL); 1311 if (unlikely(nexthdr < 0)) 1312 goto drop; 1313 1314 switch (nexthdr) { 1315 case IPPROTO_IPIP: 1316 return input_action_end_dt4(skb, slwt); 1317 case IPPROTO_IPV6: 1318 return input_action_end_dt6(skb, slwt); 1319 } 1320 1321 drop: 1322 kfree_skb(skb); 1323 return -EINVAL; 1324 } 1325 #endif 1326 1327 /* push an SRH on top of the current one */ 1328 static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1329 { 1330 struct ipv6_sr_hdr *srh; 1331 int err = -EINVAL; 1332 1333 srh = get_and_validate_srh(skb); 1334 if (!srh) 1335 goto drop; 1336 1337 err = seg6_do_srh_inline(skb, slwt->srh); 1338 if (err) 1339 goto drop; 1340 1341 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 1342 1343 seg6_lookup_nexthop(skb, NULL, 0); 1344 1345 return dst_input(skb); 1346 1347 drop: 1348 kfree_skb(skb); 1349 return err; 1350 } 1351 1352 /* encapsulate within an outer IPv6 header and a specified SRH */ 1353 static int input_action_end_b6_encap(struct sk_buff *skb, 1354 struct seg6_local_lwt *slwt) 1355 { 1356 struct ipv6_sr_hdr *srh; 1357 int err = -EINVAL; 1358 1359 srh = get_and_validate_srh(skb); 1360 if (!srh) 1361 goto drop; 1362 1363 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 1364 1365 skb_reset_inner_headers(skb); 1366 skb->encapsulation = 1; 1367 1368 err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6); 1369 if (err) 1370 goto drop; 1371 1372 skb_set_transport_header(skb, sizeof(struct ipv6hdr)); 1373 1374 seg6_lookup_nexthop(skb, NULL, 0); 1375 1376 return dst_input(skb); 1377 1378 drop: 1379 kfree_skb(skb); 1380 return err; 1381 } 1382 1383 DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states); 1384 1385 bool seg6_bpf_has_valid_srh(struct sk_buff *skb) 1386 { 1387 struct seg6_bpf_srh_state *srh_state = 1388 this_cpu_ptr(&seg6_bpf_srh_states); 1389 struct ipv6_sr_hdr *srh = srh_state->srh; 1390 1391 if (unlikely(srh == NULL)) 1392 return false; 1393 1394 if (unlikely(!srh_state->valid)) { 1395 if ((srh_state->hdrlen & 7) != 0) 1396 return false; 1397 1398 srh->hdrlen = (u8)(srh_state->hdrlen >> 3); 1399 if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3, true)) 1400 return false; 1401 1402 srh_state->valid = true; 1403 } 1404 1405 return true; 1406 } 1407 1408 static int input_action_end_bpf(struct sk_buff *skb, 1409 struct seg6_local_lwt *slwt) 1410 { 1411 struct seg6_bpf_srh_state *srh_state = 1412 this_cpu_ptr(&seg6_bpf_srh_states); 1413 struct ipv6_sr_hdr *srh; 1414 int ret; 1415 1416 srh = get_and_validate_srh(skb); 1417 if (!srh) { 1418 kfree_skb(skb); 1419 return -EINVAL; 1420 } 1421 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 1422 1423 /* preempt_disable is needed to protect the per-CPU buffer srh_state, 1424 * which is also accessed by the bpf_lwt_seg6_* helpers 1425 */ 1426 preempt_disable(); 1427 srh_state->srh = srh; 1428 srh_state->hdrlen = srh->hdrlen << 3; 1429 srh_state->valid = true; 1430 1431 rcu_read_lock(); 1432 bpf_compute_data_pointers(skb); 1433 ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb); 1434 rcu_read_unlock(); 1435 1436 switch (ret) { 1437 case BPF_OK: 1438 case BPF_REDIRECT: 1439 break; 1440 case BPF_DROP: 1441 goto drop; 1442 default: 1443 pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret); 1444 goto drop; 1445 } 1446 1447 if (srh_state->srh && !seg6_bpf_has_valid_srh(skb)) 1448 goto drop; 1449 1450 preempt_enable(); 1451 if (ret != BPF_REDIRECT) 1452 seg6_lookup_nexthop(skb, NULL, 0); 1453 1454 return dst_input(skb); 1455 1456 drop: 1457 preempt_enable(); 1458 kfree_skb(skb); 1459 return -EINVAL; 1460 } 1461 1462 static struct seg6_action_desc seg6_action_table[] = { 1463 { 1464 .action = SEG6_LOCAL_ACTION_END, 1465 .attrs = 0, 1466 .optattrs = SEG6_F_LOCAL_COUNTERS | 1467 SEG6_F_LOCAL_FLAVORS, 1468 .input = input_action_end, 1469 }, 1470 { 1471 .action = SEG6_LOCAL_ACTION_END_X, 1472 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6), 1473 .optattrs = SEG6_F_LOCAL_COUNTERS | 1474 SEG6_F_LOCAL_FLAVORS, 1475 .input = input_action_end_x, 1476 }, 1477 { 1478 .action = SEG6_LOCAL_ACTION_END_T, 1479 .attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE), 1480 .optattrs = SEG6_F_LOCAL_COUNTERS, 1481 .input = input_action_end_t, 1482 }, 1483 { 1484 .action = SEG6_LOCAL_ACTION_END_DX2, 1485 .attrs = SEG6_F_ATTR(SEG6_LOCAL_OIF), 1486 .optattrs = SEG6_F_LOCAL_COUNTERS, 1487 .input = input_action_end_dx2, 1488 }, 1489 { 1490 .action = SEG6_LOCAL_ACTION_END_DX6, 1491 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6), 1492 .optattrs = SEG6_F_LOCAL_COUNTERS, 1493 .input = input_action_end_dx6, 1494 }, 1495 { 1496 .action = SEG6_LOCAL_ACTION_END_DX4, 1497 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH4), 1498 .optattrs = SEG6_F_LOCAL_COUNTERS, 1499 .input = input_action_end_dx4, 1500 }, 1501 { 1502 .action = SEG6_LOCAL_ACTION_END_DT4, 1503 .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1504 .optattrs = SEG6_F_LOCAL_COUNTERS, 1505 #ifdef CONFIG_NET_L3_MASTER_DEV 1506 .input = input_action_end_dt4, 1507 .slwt_ops = { 1508 .build_state = seg6_end_dt4_build, 1509 }, 1510 #endif 1511 }, 1512 { 1513 .action = SEG6_LOCAL_ACTION_END_DT6, 1514 #ifdef CONFIG_NET_L3_MASTER_DEV 1515 .attrs = 0, 1516 .optattrs = SEG6_F_LOCAL_COUNTERS | 1517 SEG6_F_ATTR(SEG6_LOCAL_TABLE) | 1518 SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1519 .slwt_ops = { 1520 .build_state = seg6_end_dt6_build, 1521 }, 1522 #else 1523 .attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE), 1524 .optattrs = SEG6_F_LOCAL_COUNTERS, 1525 #endif 1526 .input = input_action_end_dt6, 1527 }, 1528 { 1529 .action = SEG6_LOCAL_ACTION_END_DT46, 1530 .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1531 .optattrs = SEG6_F_LOCAL_COUNTERS, 1532 #ifdef CONFIG_NET_L3_MASTER_DEV 1533 .input = input_action_end_dt46, 1534 .slwt_ops = { 1535 .build_state = seg6_end_dt46_build, 1536 }, 1537 #endif 1538 }, 1539 { 1540 .action = SEG6_LOCAL_ACTION_END_B6, 1541 .attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH), 1542 .optattrs = SEG6_F_LOCAL_COUNTERS, 1543 .input = input_action_end_b6, 1544 }, 1545 { 1546 .action = SEG6_LOCAL_ACTION_END_B6_ENCAP, 1547 .attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH), 1548 .optattrs = SEG6_F_LOCAL_COUNTERS, 1549 .input = input_action_end_b6_encap, 1550 .static_headroom = sizeof(struct ipv6hdr), 1551 }, 1552 { 1553 .action = SEG6_LOCAL_ACTION_END_BPF, 1554 .attrs = SEG6_F_ATTR(SEG6_LOCAL_BPF), 1555 .optattrs = SEG6_F_LOCAL_COUNTERS, 1556 .input = input_action_end_bpf, 1557 }, 1558 1559 }; 1560 1561 static struct seg6_action_desc *__get_action_desc(int action) 1562 { 1563 struct seg6_action_desc *desc; 1564 int i, count; 1565 1566 count = ARRAY_SIZE(seg6_action_table); 1567 for (i = 0; i < count; i++) { 1568 desc = &seg6_action_table[i]; 1569 if (desc->action == action) 1570 return desc; 1571 } 1572 1573 return NULL; 1574 } 1575 1576 static bool seg6_lwtunnel_counters_enabled(struct seg6_local_lwt *slwt) 1577 { 1578 return slwt->parsed_optattrs & SEG6_F_LOCAL_COUNTERS; 1579 } 1580 1581 static void seg6_local_update_counters(struct seg6_local_lwt *slwt, 1582 unsigned int len, int err) 1583 { 1584 struct pcpu_seg6_local_counters *pcounters; 1585 1586 pcounters = this_cpu_ptr(slwt->pcpu_counters); 1587 u64_stats_update_begin(&pcounters->syncp); 1588 1589 if (likely(!err)) { 1590 u64_stats_inc(&pcounters->packets); 1591 u64_stats_add(&pcounters->bytes, len); 1592 } else { 1593 u64_stats_inc(&pcounters->errors); 1594 } 1595 1596 u64_stats_update_end(&pcounters->syncp); 1597 } 1598 1599 static int seg6_local_input_core(struct net *net, struct sock *sk, 1600 struct sk_buff *skb) 1601 { 1602 struct dst_entry *orig_dst = skb_dst(skb); 1603 struct seg6_action_desc *desc; 1604 struct seg6_local_lwt *slwt; 1605 unsigned int len = skb->len; 1606 int rc; 1607 1608 slwt = seg6_local_lwtunnel(orig_dst->lwtstate); 1609 desc = slwt->desc; 1610 1611 rc = desc->input(skb, slwt); 1612 1613 if (!seg6_lwtunnel_counters_enabled(slwt)) 1614 return rc; 1615 1616 seg6_local_update_counters(slwt, len, rc); 1617 1618 return rc; 1619 } 1620 1621 static int seg6_local_input(struct sk_buff *skb) 1622 { 1623 if (skb->protocol != htons(ETH_P_IPV6)) { 1624 kfree_skb(skb); 1625 return -EINVAL; 1626 } 1627 1628 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) 1629 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, 1630 dev_net(skb->dev), NULL, skb, skb->dev, NULL, 1631 seg6_local_input_core); 1632 1633 return seg6_local_input_core(dev_net(skb->dev), NULL, skb); 1634 } 1635 1636 static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = { 1637 [SEG6_LOCAL_ACTION] = { .type = NLA_U32 }, 1638 [SEG6_LOCAL_SRH] = { .type = NLA_BINARY }, 1639 [SEG6_LOCAL_TABLE] = { .type = NLA_U32 }, 1640 [SEG6_LOCAL_VRFTABLE] = { .type = NLA_U32 }, 1641 [SEG6_LOCAL_NH4] = { .type = NLA_BINARY, 1642 .len = sizeof(struct in_addr) }, 1643 [SEG6_LOCAL_NH6] = { .type = NLA_BINARY, 1644 .len = sizeof(struct in6_addr) }, 1645 [SEG6_LOCAL_IIF] = { .type = NLA_U32 }, 1646 [SEG6_LOCAL_OIF] = { .type = NLA_U32 }, 1647 [SEG6_LOCAL_BPF] = { .type = NLA_NESTED }, 1648 [SEG6_LOCAL_COUNTERS] = { .type = NLA_NESTED }, 1649 [SEG6_LOCAL_FLAVORS] = { .type = NLA_NESTED }, 1650 }; 1651 1652 static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1653 struct netlink_ext_ack *extack) 1654 { 1655 struct ipv6_sr_hdr *srh; 1656 int len; 1657 1658 srh = nla_data(attrs[SEG6_LOCAL_SRH]); 1659 len = nla_len(attrs[SEG6_LOCAL_SRH]); 1660 1661 /* SRH must contain at least one segment */ 1662 if (len < sizeof(*srh) + sizeof(struct in6_addr)) 1663 return -EINVAL; 1664 1665 if (!seg6_validate_srh(srh, len, false)) 1666 return -EINVAL; 1667 1668 slwt->srh = kmemdup(srh, len, GFP_KERNEL); 1669 if (!slwt->srh) 1670 return -ENOMEM; 1671 1672 slwt->headroom += len; 1673 1674 return 0; 1675 } 1676 1677 static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1678 { 1679 struct ipv6_sr_hdr *srh; 1680 struct nlattr *nla; 1681 int len; 1682 1683 srh = slwt->srh; 1684 len = (srh->hdrlen + 1) << 3; 1685 1686 nla = nla_reserve(skb, SEG6_LOCAL_SRH, len); 1687 if (!nla) 1688 return -EMSGSIZE; 1689 1690 memcpy(nla_data(nla), srh, len); 1691 1692 return 0; 1693 } 1694 1695 static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1696 { 1697 int len = (a->srh->hdrlen + 1) << 3; 1698 1699 if (len != ((b->srh->hdrlen + 1) << 3)) 1700 return 1; 1701 1702 return memcmp(a->srh, b->srh, len); 1703 } 1704 1705 static void destroy_attr_srh(struct seg6_local_lwt *slwt) 1706 { 1707 kfree(slwt->srh); 1708 } 1709 1710 static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1711 struct netlink_ext_ack *extack) 1712 { 1713 slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]); 1714 1715 return 0; 1716 } 1717 1718 static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1719 { 1720 if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table)) 1721 return -EMSGSIZE; 1722 1723 return 0; 1724 } 1725 1726 static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1727 { 1728 if (a->table != b->table) 1729 return 1; 1730 1731 return 0; 1732 } 1733 1734 static struct 1735 seg6_end_dt_info *seg6_possible_end_dt_info(struct seg6_local_lwt *slwt) 1736 { 1737 #ifdef CONFIG_NET_L3_MASTER_DEV 1738 return &slwt->dt_info; 1739 #else 1740 return ERR_PTR(-EOPNOTSUPP); 1741 #endif 1742 } 1743 1744 static int parse_nla_vrftable(struct nlattr **attrs, 1745 struct seg6_local_lwt *slwt, 1746 struct netlink_ext_ack *extack) 1747 { 1748 struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt); 1749 1750 if (IS_ERR(info)) 1751 return PTR_ERR(info); 1752 1753 info->vrf_table = nla_get_u32(attrs[SEG6_LOCAL_VRFTABLE]); 1754 1755 return 0; 1756 } 1757 1758 static int put_nla_vrftable(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1759 { 1760 struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt); 1761 1762 if (IS_ERR(info)) 1763 return PTR_ERR(info); 1764 1765 if (nla_put_u32(skb, SEG6_LOCAL_VRFTABLE, info->vrf_table)) 1766 return -EMSGSIZE; 1767 1768 return 0; 1769 } 1770 1771 static int cmp_nla_vrftable(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1772 { 1773 struct seg6_end_dt_info *info_a = seg6_possible_end_dt_info(a); 1774 struct seg6_end_dt_info *info_b = seg6_possible_end_dt_info(b); 1775 1776 if (info_a->vrf_table != info_b->vrf_table) 1777 return 1; 1778 1779 return 0; 1780 } 1781 1782 static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1783 struct netlink_ext_ack *extack) 1784 { 1785 memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]), 1786 sizeof(struct in_addr)); 1787 1788 return 0; 1789 } 1790 1791 static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1792 { 1793 struct nlattr *nla; 1794 1795 nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr)); 1796 if (!nla) 1797 return -EMSGSIZE; 1798 1799 memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr)); 1800 1801 return 0; 1802 } 1803 1804 static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1805 { 1806 return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr)); 1807 } 1808 1809 static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1810 struct netlink_ext_ack *extack) 1811 { 1812 memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]), 1813 sizeof(struct in6_addr)); 1814 1815 return 0; 1816 } 1817 1818 static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1819 { 1820 struct nlattr *nla; 1821 1822 nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr)); 1823 if (!nla) 1824 return -EMSGSIZE; 1825 1826 memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr)); 1827 1828 return 0; 1829 } 1830 1831 static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1832 { 1833 return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr)); 1834 } 1835 1836 static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1837 struct netlink_ext_ack *extack) 1838 { 1839 slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]); 1840 1841 return 0; 1842 } 1843 1844 static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1845 { 1846 if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif)) 1847 return -EMSGSIZE; 1848 1849 return 0; 1850 } 1851 1852 static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1853 { 1854 if (a->iif != b->iif) 1855 return 1; 1856 1857 return 0; 1858 } 1859 1860 static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1861 struct netlink_ext_ack *extack) 1862 { 1863 slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]); 1864 1865 return 0; 1866 } 1867 1868 static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1869 { 1870 if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif)) 1871 return -EMSGSIZE; 1872 1873 return 0; 1874 } 1875 1876 static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1877 { 1878 if (a->oif != b->oif) 1879 return 1; 1880 1881 return 0; 1882 } 1883 1884 #define MAX_PROG_NAME 256 1885 static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = { 1886 [SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, }, 1887 [SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING, 1888 .len = MAX_PROG_NAME }, 1889 }; 1890 1891 static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1892 struct netlink_ext_ack *extack) 1893 { 1894 struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1]; 1895 struct bpf_prog *p; 1896 int ret; 1897 u32 fd; 1898 1899 ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_BPF_PROG_MAX, 1900 attrs[SEG6_LOCAL_BPF], 1901 bpf_prog_policy, NULL); 1902 if (ret < 0) 1903 return ret; 1904 1905 if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME]) 1906 return -EINVAL; 1907 1908 slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL); 1909 if (!slwt->bpf.name) 1910 return -ENOMEM; 1911 1912 fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]); 1913 p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL); 1914 if (IS_ERR(p)) { 1915 kfree(slwt->bpf.name); 1916 return PTR_ERR(p); 1917 } 1918 1919 slwt->bpf.prog = p; 1920 return 0; 1921 } 1922 1923 static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1924 { 1925 struct nlattr *nest; 1926 1927 if (!slwt->bpf.prog) 1928 return 0; 1929 1930 nest = nla_nest_start_noflag(skb, SEG6_LOCAL_BPF); 1931 if (!nest) 1932 return -EMSGSIZE; 1933 1934 if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id)) 1935 return -EMSGSIZE; 1936 1937 if (slwt->bpf.name && 1938 nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name)) 1939 return -EMSGSIZE; 1940 1941 return nla_nest_end(skb, nest); 1942 } 1943 1944 static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1945 { 1946 if (!a->bpf.name && !b->bpf.name) 1947 return 0; 1948 1949 if (!a->bpf.name || !b->bpf.name) 1950 return 1; 1951 1952 return strcmp(a->bpf.name, b->bpf.name); 1953 } 1954 1955 static void destroy_attr_bpf(struct seg6_local_lwt *slwt) 1956 { 1957 kfree(slwt->bpf.name); 1958 if (slwt->bpf.prog) 1959 bpf_prog_put(slwt->bpf.prog); 1960 } 1961 1962 static const struct 1963 nla_policy seg6_local_counters_policy[SEG6_LOCAL_CNT_MAX + 1] = { 1964 [SEG6_LOCAL_CNT_PACKETS] = { .type = NLA_U64 }, 1965 [SEG6_LOCAL_CNT_BYTES] = { .type = NLA_U64 }, 1966 [SEG6_LOCAL_CNT_ERRORS] = { .type = NLA_U64 }, 1967 }; 1968 1969 static int parse_nla_counters(struct nlattr **attrs, 1970 struct seg6_local_lwt *slwt, 1971 struct netlink_ext_ack *extack) 1972 { 1973 struct pcpu_seg6_local_counters __percpu *pcounters; 1974 struct nlattr *tb[SEG6_LOCAL_CNT_MAX + 1]; 1975 int ret; 1976 1977 ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_CNT_MAX, 1978 attrs[SEG6_LOCAL_COUNTERS], 1979 seg6_local_counters_policy, NULL); 1980 if (ret < 0) 1981 return ret; 1982 1983 /* basic support for SRv6 Behavior counters requires at least: 1984 * packets, bytes and errors. 1985 */ 1986 if (!tb[SEG6_LOCAL_CNT_PACKETS] || !tb[SEG6_LOCAL_CNT_BYTES] || 1987 !tb[SEG6_LOCAL_CNT_ERRORS]) 1988 return -EINVAL; 1989 1990 /* counters are always zero initialized */ 1991 pcounters = seg6_local_alloc_pcpu_counters(GFP_KERNEL); 1992 if (!pcounters) 1993 return -ENOMEM; 1994 1995 slwt->pcpu_counters = pcounters; 1996 1997 return 0; 1998 } 1999 2000 static int seg6_local_fill_nla_counters(struct sk_buff *skb, 2001 struct seg6_local_counters *counters) 2002 { 2003 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_PACKETS, counters->packets, 2004 SEG6_LOCAL_CNT_PAD)) 2005 return -EMSGSIZE; 2006 2007 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_BYTES, counters->bytes, 2008 SEG6_LOCAL_CNT_PAD)) 2009 return -EMSGSIZE; 2010 2011 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_ERRORS, counters->errors, 2012 SEG6_LOCAL_CNT_PAD)) 2013 return -EMSGSIZE; 2014 2015 return 0; 2016 } 2017 2018 static int put_nla_counters(struct sk_buff *skb, struct seg6_local_lwt *slwt) 2019 { 2020 struct seg6_local_counters counters = { 0, 0, 0 }; 2021 struct nlattr *nest; 2022 int rc, i; 2023 2024 nest = nla_nest_start(skb, SEG6_LOCAL_COUNTERS); 2025 if (!nest) 2026 return -EMSGSIZE; 2027 2028 for_each_possible_cpu(i) { 2029 struct pcpu_seg6_local_counters *pcounters; 2030 u64 packets, bytes, errors; 2031 unsigned int start; 2032 2033 pcounters = per_cpu_ptr(slwt->pcpu_counters, i); 2034 do { 2035 start = u64_stats_fetch_begin(&pcounters->syncp); 2036 2037 packets = u64_stats_read(&pcounters->packets); 2038 bytes = u64_stats_read(&pcounters->bytes); 2039 errors = u64_stats_read(&pcounters->errors); 2040 2041 } while (u64_stats_fetch_retry(&pcounters->syncp, start)); 2042 2043 counters.packets += packets; 2044 counters.bytes += bytes; 2045 counters.errors += errors; 2046 } 2047 2048 rc = seg6_local_fill_nla_counters(skb, &counters); 2049 if (rc < 0) { 2050 nla_nest_cancel(skb, nest); 2051 return rc; 2052 } 2053 2054 return nla_nest_end(skb, nest); 2055 } 2056 2057 static int cmp_nla_counters(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 2058 { 2059 /* a and b are equal if both have pcpu_counters set or not */ 2060 return (!!((unsigned long)a->pcpu_counters)) ^ 2061 (!!((unsigned long)b->pcpu_counters)); 2062 } 2063 2064 static void destroy_attr_counters(struct seg6_local_lwt *slwt) 2065 { 2066 free_percpu(slwt->pcpu_counters); 2067 } 2068 2069 static const 2070 struct nla_policy seg6_local_flavors_policy[SEG6_LOCAL_FLV_MAX + 1] = { 2071 [SEG6_LOCAL_FLV_OPERATION] = { .type = NLA_U32 }, 2072 [SEG6_LOCAL_FLV_LCBLOCK_BITS] = { .type = NLA_U8 }, 2073 [SEG6_LOCAL_FLV_LCNODE_FN_BITS] = { .type = NLA_U8 }, 2074 }; 2075 2076 /* check whether the lengths of the Locator-Block and Locator-Node Function 2077 * are compatible with the dimension of a C-SID container. 2078 */ 2079 static int seg6_chk_next_csid_cfg(__u8 block_len, __u8 func_len) 2080 { 2081 /* Locator-Block and Locator-Node Function cannot exceed 128 bits 2082 * (i.e. C-SID container lenghts). 2083 */ 2084 if (next_csid_chk_cntr_bits(block_len, func_len)) 2085 return -EINVAL; 2086 2087 /* Locator-Block length must be greater than zero and evenly divisible 2088 * by 8. There must be room for a Locator-Node Function, at least. 2089 */ 2090 if (next_csid_chk_lcblock_bits(block_len)) 2091 return -EINVAL; 2092 2093 /* Locator-Node Function length must be greater than zero and evenly 2094 * divisible by 8. There must be room for the Locator-Block. 2095 */ 2096 if (next_csid_chk_lcnode_fn_bits(func_len)) 2097 return -EINVAL; 2098 2099 return 0; 2100 } 2101 2102 static int seg6_parse_nla_next_csid_cfg(struct nlattr **tb, 2103 struct seg6_flavors_info *finfo, 2104 struct netlink_ext_ack *extack) 2105 { 2106 __u8 func_len = SEG6_LOCAL_LCNODE_FN_DBITS; 2107 __u8 block_len = SEG6_LOCAL_LCBLOCK_DBITS; 2108 int rc; 2109 2110 if (tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]) 2111 block_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]); 2112 2113 if (tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]) 2114 func_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]); 2115 2116 rc = seg6_chk_next_csid_cfg(block_len, func_len); 2117 if (rc < 0) { 2118 NL_SET_ERR_MSG(extack, 2119 "Invalid Locator Block/Node Function lengths"); 2120 return rc; 2121 } 2122 2123 finfo->lcblock_bits = block_len; 2124 finfo->lcnode_func_bits = func_len; 2125 2126 return 0; 2127 } 2128 2129 static int parse_nla_flavors(struct nlattr **attrs, struct seg6_local_lwt *slwt, 2130 struct netlink_ext_ack *extack) 2131 { 2132 struct seg6_flavors_info *finfo = &slwt->flv_info; 2133 struct nlattr *tb[SEG6_LOCAL_FLV_MAX + 1]; 2134 int action = slwt->action; 2135 __u32 fops, supp_fops; 2136 int rc; 2137 2138 rc = nla_parse_nested_deprecated(tb, SEG6_LOCAL_FLV_MAX, 2139 attrs[SEG6_LOCAL_FLAVORS], 2140 seg6_local_flavors_policy, NULL); 2141 if (rc < 0) 2142 return rc; 2143 2144 /* this attribute MUST always be present since it represents the Flavor 2145 * operation(s) to be carried out. 2146 */ 2147 if (!tb[SEG6_LOCAL_FLV_OPERATION]) 2148 return -EINVAL; 2149 2150 fops = nla_get_u32(tb[SEG6_LOCAL_FLV_OPERATION]); 2151 rc = seg6_flv_supp_ops_by_action(action, &supp_fops); 2152 if (rc < 0 || (fops & ~supp_fops)) { 2153 NL_SET_ERR_MSG(extack, "Unsupported Flavor operation(s)"); 2154 return -EOPNOTSUPP; 2155 } 2156 2157 finfo->flv_ops = fops; 2158 2159 if (seg6_next_csid_enabled(fops)) { 2160 /* Locator-Block and Locator-Node Function lengths can be 2161 * provided by the user space. Otherwise, default values are 2162 * applied. 2163 */ 2164 rc = seg6_parse_nla_next_csid_cfg(tb, finfo, extack); 2165 if (rc < 0) 2166 return rc; 2167 } 2168 2169 return 0; 2170 } 2171 2172 static int seg6_fill_nla_next_csid_cfg(struct sk_buff *skb, 2173 struct seg6_flavors_info *finfo) 2174 { 2175 if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCBLOCK_BITS, finfo->lcblock_bits)) 2176 return -EMSGSIZE; 2177 2178 if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCNODE_FN_BITS, 2179 finfo->lcnode_func_bits)) 2180 return -EMSGSIZE; 2181 2182 return 0; 2183 } 2184 2185 static int put_nla_flavors(struct sk_buff *skb, struct seg6_local_lwt *slwt) 2186 { 2187 struct seg6_flavors_info *finfo = &slwt->flv_info; 2188 __u32 fops = finfo->flv_ops; 2189 struct nlattr *nest; 2190 int rc; 2191 2192 nest = nla_nest_start(skb, SEG6_LOCAL_FLAVORS); 2193 if (!nest) 2194 return -EMSGSIZE; 2195 2196 if (nla_put_u32(skb, SEG6_LOCAL_FLV_OPERATION, fops)) { 2197 rc = -EMSGSIZE; 2198 goto err; 2199 } 2200 2201 if (seg6_next_csid_enabled(fops)) { 2202 rc = seg6_fill_nla_next_csid_cfg(skb, finfo); 2203 if (rc < 0) 2204 goto err; 2205 } 2206 2207 return nla_nest_end(skb, nest); 2208 2209 err: 2210 nla_nest_cancel(skb, nest); 2211 return rc; 2212 } 2213 2214 static int seg6_cmp_nla_next_csid_cfg(struct seg6_flavors_info *finfo_a, 2215 struct seg6_flavors_info *finfo_b) 2216 { 2217 if (finfo_a->lcblock_bits != finfo_b->lcblock_bits) 2218 return 1; 2219 2220 if (finfo_a->lcnode_func_bits != finfo_b->lcnode_func_bits) 2221 return 1; 2222 2223 return 0; 2224 } 2225 2226 static int cmp_nla_flavors(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 2227 { 2228 struct seg6_flavors_info *finfo_a = &a->flv_info; 2229 struct seg6_flavors_info *finfo_b = &b->flv_info; 2230 2231 if (finfo_a->flv_ops != finfo_b->flv_ops) 2232 return 1; 2233 2234 if (seg6_next_csid_enabled(finfo_a->flv_ops)) { 2235 if (seg6_cmp_nla_next_csid_cfg(finfo_a, finfo_b)) 2236 return 1; 2237 } 2238 2239 return 0; 2240 } 2241 2242 static int encap_size_flavors(struct seg6_local_lwt *slwt) 2243 { 2244 struct seg6_flavors_info *finfo = &slwt->flv_info; 2245 int nlsize; 2246 2247 nlsize = nla_total_size(0) + /* nest SEG6_LOCAL_FLAVORS */ 2248 nla_total_size(4); /* SEG6_LOCAL_FLV_OPERATION */ 2249 2250 if (seg6_next_csid_enabled(finfo->flv_ops)) 2251 nlsize += nla_total_size(1) + /* SEG6_LOCAL_FLV_LCBLOCK_BITS */ 2252 nla_total_size(1); /* SEG6_LOCAL_FLV_LCNODE_FN_BITS */ 2253 2254 return nlsize; 2255 } 2256 2257 struct seg6_action_param { 2258 int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt, 2259 struct netlink_ext_ack *extack); 2260 int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt); 2261 int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b); 2262 2263 /* optional destroy() callback useful for releasing resources which 2264 * have been previously acquired in the corresponding parse() 2265 * function. 2266 */ 2267 void (*destroy)(struct seg6_local_lwt *slwt); 2268 }; 2269 2270 static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = { 2271 [SEG6_LOCAL_SRH] = { .parse = parse_nla_srh, 2272 .put = put_nla_srh, 2273 .cmp = cmp_nla_srh, 2274 .destroy = destroy_attr_srh }, 2275 2276 [SEG6_LOCAL_TABLE] = { .parse = parse_nla_table, 2277 .put = put_nla_table, 2278 .cmp = cmp_nla_table }, 2279 2280 [SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4, 2281 .put = put_nla_nh4, 2282 .cmp = cmp_nla_nh4 }, 2283 2284 [SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6, 2285 .put = put_nla_nh6, 2286 .cmp = cmp_nla_nh6 }, 2287 2288 [SEG6_LOCAL_IIF] = { .parse = parse_nla_iif, 2289 .put = put_nla_iif, 2290 .cmp = cmp_nla_iif }, 2291 2292 [SEG6_LOCAL_OIF] = { .parse = parse_nla_oif, 2293 .put = put_nla_oif, 2294 .cmp = cmp_nla_oif }, 2295 2296 [SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf, 2297 .put = put_nla_bpf, 2298 .cmp = cmp_nla_bpf, 2299 .destroy = destroy_attr_bpf }, 2300 2301 [SEG6_LOCAL_VRFTABLE] = { .parse = parse_nla_vrftable, 2302 .put = put_nla_vrftable, 2303 .cmp = cmp_nla_vrftable }, 2304 2305 [SEG6_LOCAL_COUNTERS] = { .parse = parse_nla_counters, 2306 .put = put_nla_counters, 2307 .cmp = cmp_nla_counters, 2308 .destroy = destroy_attr_counters }, 2309 2310 [SEG6_LOCAL_FLAVORS] = { .parse = parse_nla_flavors, 2311 .put = put_nla_flavors, 2312 .cmp = cmp_nla_flavors }, 2313 }; 2314 2315 /* call the destroy() callback (if available) for each set attribute in 2316 * @parsed_attrs, starting from the first attribute up to the @max_parsed 2317 * (excluded) attribute. 2318 */ 2319 static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed, 2320 struct seg6_local_lwt *slwt) 2321 { 2322 struct seg6_action_param *param; 2323 int i; 2324 2325 /* Every required seg6local attribute is identified by an ID which is 2326 * encoded as a flag (i.e: 1 << ID) in the 'attrs' bitmask; 2327 * 2328 * We scan the 'parsed_attrs' bitmask, starting from the first attribute 2329 * up to the @max_parsed (excluded) attribute. 2330 * For each set attribute, we retrieve the corresponding destroy() 2331 * callback. If the callback is not available, then we skip to the next 2332 * attribute; otherwise, we call the destroy() callback. 2333 */ 2334 for (i = SEG6_LOCAL_SRH; i < max_parsed; ++i) { 2335 if (!(parsed_attrs & SEG6_F_ATTR(i))) 2336 continue; 2337 2338 param = &seg6_action_params[i]; 2339 2340 if (param->destroy) 2341 param->destroy(slwt); 2342 } 2343 } 2344 2345 /* release all the resources that may have been acquired during parsing 2346 * operations. 2347 */ 2348 static void destroy_attrs(struct seg6_local_lwt *slwt) 2349 { 2350 unsigned long attrs = slwt->desc->attrs | slwt->parsed_optattrs; 2351 2352 __destroy_attrs(attrs, SEG6_LOCAL_MAX + 1, slwt); 2353 } 2354 2355 static int parse_nla_optional_attrs(struct nlattr **attrs, 2356 struct seg6_local_lwt *slwt, 2357 struct netlink_ext_ack *extack) 2358 { 2359 struct seg6_action_desc *desc = slwt->desc; 2360 unsigned long parsed_optattrs = 0; 2361 struct seg6_action_param *param; 2362 int err, i; 2363 2364 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; ++i) { 2365 if (!(desc->optattrs & SEG6_F_ATTR(i)) || !attrs[i]) 2366 continue; 2367 2368 /* once here, the i-th attribute is provided by the 2369 * userspace AND it is identified optional as well. 2370 */ 2371 param = &seg6_action_params[i]; 2372 2373 err = param->parse(attrs, slwt, extack); 2374 if (err < 0) 2375 goto parse_optattrs_err; 2376 2377 /* current attribute has been correctly parsed */ 2378 parsed_optattrs |= SEG6_F_ATTR(i); 2379 } 2380 2381 /* store in the tunnel state all the optional attributed successfully 2382 * parsed. 2383 */ 2384 slwt->parsed_optattrs = parsed_optattrs; 2385 2386 return 0; 2387 2388 parse_optattrs_err: 2389 __destroy_attrs(parsed_optattrs, i, slwt); 2390 2391 return err; 2392 } 2393 2394 /* call the custom constructor of the behavior during its initialization phase 2395 * and after that all its attributes have been parsed successfully. 2396 */ 2397 static int 2398 seg6_local_lwtunnel_build_state(struct seg6_local_lwt *slwt, const void *cfg, 2399 struct netlink_ext_ack *extack) 2400 { 2401 struct seg6_action_desc *desc = slwt->desc; 2402 struct seg6_local_lwtunnel_ops *ops; 2403 2404 ops = &desc->slwt_ops; 2405 if (!ops->build_state) 2406 return 0; 2407 2408 return ops->build_state(slwt, cfg, extack); 2409 } 2410 2411 /* call the custom destructor of the behavior which is invoked before the 2412 * tunnel is going to be destroyed. 2413 */ 2414 static void seg6_local_lwtunnel_destroy_state(struct seg6_local_lwt *slwt) 2415 { 2416 struct seg6_action_desc *desc = slwt->desc; 2417 struct seg6_local_lwtunnel_ops *ops; 2418 2419 ops = &desc->slwt_ops; 2420 if (!ops->destroy_state) 2421 return; 2422 2423 ops->destroy_state(slwt); 2424 } 2425 2426 static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt, 2427 struct netlink_ext_ack *extack) 2428 { 2429 struct seg6_action_param *param; 2430 struct seg6_action_desc *desc; 2431 unsigned long invalid_attrs; 2432 int i, err; 2433 2434 desc = __get_action_desc(slwt->action); 2435 if (!desc) 2436 return -EINVAL; 2437 2438 if (!desc->input) 2439 return -EOPNOTSUPP; 2440 2441 slwt->desc = desc; 2442 slwt->headroom += desc->static_headroom; 2443 2444 /* Forcing the desc->optattrs *set* and the desc->attrs *set* to be 2445 * disjoined, this allow us to release acquired resources by optional 2446 * attributes and by required attributes independently from each other 2447 * without any interference. 2448 * In other terms, we are sure that we do not release some the acquired 2449 * resources twice. 2450 * 2451 * Note that if an attribute is configured both as required and as 2452 * optional, it means that the user has messed something up in the 2453 * seg6_action_table. Therefore, this check is required for SRv6 2454 * behaviors to work properly. 2455 */ 2456 invalid_attrs = desc->attrs & desc->optattrs; 2457 if (invalid_attrs) { 2458 WARN_ONCE(1, 2459 "An attribute cannot be both required AND optional"); 2460 return -EINVAL; 2461 } 2462 2463 /* parse the required attributes */ 2464 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2465 if (desc->attrs & SEG6_F_ATTR(i)) { 2466 if (!attrs[i]) 2467 return -EINVAL; 2468 2469 param = &seg6_action_params[i]; 2470 2471 err = param->parse(attrs, slwt, extack); 2472 if (err < 0) 2473 goto parse_attrs_err; 2474 } 2475 } 2476 2477 /* parse the optional attributes, if any */ 2478 err = parse_nla_optional_attrs(attrs, slwt, extack); 2479 if (err < 0) 2480 goto parse_attrs_err; 2481 2482 return 0; 2483 2484 parse_attrs_err: 2485 /* release any resource that may have been acquired during the i-1 2486 * parse() operations. 2487 */ 2488 __destroy_attrs(desc->attrs, i, slwt); 2489 2490 return err; 2491 } 2492 2493 static int seg6_local_build_state(struct net *net, struct nlattr *nla, 2494 unsigned int family, const void *cfg, 2495 struct lwtunnel_state **ts, 2496 struct netlink_ext_ack *extack) 2497 { 2498 struct nlattr *tb[SEG6_LOCAL_MAX + 1]; 2499 struct lwtunnel_state *newts; 2500 struct seg6_local_lwt *slwt; 2501 int err; 2502 2503 if (family != AF_INET6) 2504 return -EINVAL; 2505 2506 err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla, 2507 seg6_local_policy, extack); 2508 2509 if (err < 0) 2510 return err; 2511 2512 if (!tb[SEG6_LOCAL_ACTION]) 2513 return -EINVAL; 2514 2515 newts = lwtunnel_state_alloc(sizeof(*slwt)); 2516 if (!newts) 2517 return -ENOMEM; 2518 2519 slwt = seg6_local_lwtunnel(newts); 2520 slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]); 2521 2522 err = parse_nla_action(tb, slwt, extack); 2523 if (err < 0) 2524 goto out_free; 2525 2526 err = seg6_local_lwtunnel_build_state(slwt, cfg, extack); 2527 if (err < 0) 2528 goto out_destroy_attrs; 2529 2530 newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL; 2531 newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT; 2532 newts->headroom = slwt->headroom; 2533 2534 *ts = newts; 2535 2536 return 0; 2537 2538 out_destroy_attrs: 2539 destroy_attrs(slwt); 2540 out_free: 2541 kfree(newts); 2542 return err; 2543 } 2544 2545 static void seg6_local_destroy_state(struct lwtunnel_state *lwt) 2546 { 2547 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2548 2549 seg6_local_lwtunnel_destroy_state(slwt); 2550 2551 destroy_attrs(slwt); 2552 2553 return; 2554 } 2555 2556 static int seg6_local_fill_encap(struct sk_buff *skb, 2557 struct lwtunnel_state *lwt) 2558 { 2559 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2560 struct seg6_action_param *param; 2561 unsigned long attrs; 2562 int i, err; 2563 2564 if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action)) 2565 return -EMSGSIZE; 2566 2567 attrs = slwt->desc->attrs | slwt->parsed_optattrs; 2568 2569 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2570 if (attrs & SEG6_F_ATTR(i)) { 2571 param = &seg6_action_params[i]; 2572 err = param->put(skb, slwt); 2573 if (err < 0) 2574 return err; 2575 } 2576 } 2577 2578 return 0; 2579 } 2580 2581 static int seg6_local_get_encap_size(struct lwtunnel_state *lwt) 2582 { 2583 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2584 unsigned long attrs; 2585 int nlsize; 2586 2587 nlsize = nla_total_size(4); /* action */ 2588 2589 attrs = slwt->desc->attrs | slwt->parsed_optattrs; 2590 2591 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_SRH)) 2592 nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3); 2593 2594 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE)) 2595 nlsize += nla_total_size(4); 2596 2597 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH4)) 2598 nlsize += nla_total_size(4); 2599 2600 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH6)) 2601 nlsize += nla_total_size(16); 2602 2603 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_IIF)) 2604 nlsize += nla_total_size(4); 2605 2606 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_OIF)) 2607 nlsize += nla_total_size(4); 2608 2609 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_BPF)) 2610 nlsize += nla_total_size(sizeof(struct nlattr)) + 2611 nla_total_size(MAX_PROG_NAME) + 2612 nla_total_size(4); 2613 2614 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE)) 2615 nlsize += nla_total_size(4); 2616 2617 if (attrs & SEG6_F_LOCAL_COUNTERS) 2618 nlsize += nla_total_size(0) + /* nest SEG6_LOCAL_COUNTERS */ 2619 /* SEG6_LOCAL_CNT_PACKETS */ 2620 nla_total_size_64bit(sizeof(__u64)) + 2621 /* SEG6_LOCAL_CNT_BYTES */ 2622 nla_total_size_64bit(sizeof(__u64)) + 2623 /* SEG6_LOCAL_CNT_ERRORS */ 2624 nla_total_size_64bit(sizeof(__u64)); 2625 2626 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_FLAVORS)) 2627 nlsize += encap_size_flavors(slwt); 2628 2629 return nlsize; 2630 } 2631 2632 static int seg6_local_cmp_encap(struct lwtunnel_state *a, 2633 struct lwtunnel_state *b) 2634 { 2635 struct seg6_local_lwt *slwt_a, *slwt_b; 2636 struct seg6_action_param *param; 2637 unsigned long attrs_a, attrs_b; 2638 int i; 2639 2640 slwt_a = seg6_local_lwtunnel(a); 2641 slwt_b = seg6_local_lwtunnel(b); 2642 2643 if (slwt_a->action != slwt_b->action) 2644 return 1; 2645 2646 attrs_a = slwt_a->desc->attrs | slwt_a->parsed_optattrs; 2647 attrs_b = slwt_b->desc->attrs | slwt_b->parsed_optattrs; 2648 2649 if (attrs_a != attrs_b) 2650 return 1; 2651 2652 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2653 if (attrs_a & SEG6_F_ATTR(i)) { 2654 param = &seg6_action_params[i]; 2655 if (param->cmp(slwt_a, slwt_b)) 2656 return 1; 2657 } 2658 } 2659 2660 return 0; 2661 } 2662 2663 static const struct lwtunnel_encap_ops seg6_local_ops = { 2664 .build_state = seg6_local_build_state, 2665 .destroy_state = seg6_local_destroy_state, 2666 .input = seg6_local_input, 2667 .fill_encap = seg6_local_fill_encap, 2668 .get_encap_size = seg6_local_get_encap_size, 2669 .cmp_encap = seg6_local_cmp_encap, 2670 .owner = THIS_MODULE, 2671 }; 2672 2673 int __init seg6_local_init(void) 2674 { 2675 /* If the max total number of defined attributes is reached, then your 2676 * kernel build stops here. 2677 * 2678 * This check is required to avoid arithmetic overflows when processing 2679 * behavior attributes and the maximum number of defined attributes 2680 * exceeds the allowed value. 2681 */ 2682 BUILD_BUG_ON(SEG6_LOCAL_MAX + 1 > BITS_PER_TYPE(unsigned long)); 2683 2684 /* Check whether the number of defined flavors exceeds the maximum 2685 * allowed value. 2686 */ 2687 BUILD_BUG_ON(SEG6_LOCAL_FLV_OP_MAX + 1 > BITS_PER_TYPE(__u32)); 2688 2689 /* If the default NEXT-C-SID Locator-Block/Node Function lengths (in 2690 * bits) have been changed with invalid values, kernel build stops 2691 * here. 2692 */ 2693 BUILD_BUG_ON(next_csid_chk_cntr_bits(SEG6_LOCAL_LCBLOCK_DBITS, 2694 SEG6_LOCAL_LCNODE_FN_DBITS)); 2695 BUILD_BUG_ON(next_csid_chk_lcblock_bits(SEG6_LOCAL_LCBLOCK_DBITS)); 2696 BUILD_BUG_ON(next_csid_chk_lcnode_fn_bits(SEG6_LOCAL_LCNODE_FN_DBITS)); 2697 2698 /* To be memory efficient, we use 'u8' to represent the different 2699 * actions related to RFC8986 flavors. If the kernel build stops here, 2700 * it means that it is not possible to correctly encode these actions 2701 * with the data type chosen for the action table. 2702 */ 2703 BUILD_BUG_ON(SEG6_LOCAL_FLV_ACT_MAX > (typeof(flv8986_act_tbl[0]))~0U); 2704 2705 return lwtunnel_encap_add_ops(&seg6_local_ops, 2706 LWTUNNEL_ENCAP_SEG6_LOCAL); 2707 } 2708 2709 void seg6_local_exit(void) 2710 { 2711 lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL); 2712 } 2713