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, skb->dev, 945 NULL, 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, skb->dev, 995 NULL, 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 .bh_lock = INIT_LOCAL_LOCK(bh_lock), 1385 }; 1386 1387 bool seg6_bpf_has_valid_srh(struct sk_buff *skb) 1388 { 1389 struct seg6_bpf_srh_state *srh_state = 1390 this_cpu_ptr(&seg6_bpf_srh_states); 1391 struct ipv6_sr_hdr *srh = srh_state->srh; 1392 1393 lockdep_assert_held(&srh_state->bh_lock); 1394 if (unlikely(srh == NULL)) 1395 return false; 1396 1397 if (unlikely(!srh_state->valid)) { 1398 if ((srh_state->hdrlen & 7) != 0) 1399 return false; 1400 1401 srh->hdrlen = (u8)(srh_state->hdrlen >> 3); 1402 if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3, true)) 1403 return false; 1404 1405 srh_state->valid = true; 1406 } 1407 1408 return true; 1409 } 1410 1411 static int input_action_end_bpf(struct sk_buff *skb, 1412 struct seg6_local_lwt *slwt) 1413 { 1414 struct seg6_bpf_srh_state *srh_state; 1415 struct ipv6_sr_hdr *srh; 1416 int ret; 1417 1418 srh = get_and_validate_srh(skb); 1419 if (!srh) { 1420 kfree_skb(skb); 1421 return -EINVAL; 1422 } 1423 advance_nextseg(srh, &ipv6_hdr(skb)->daddr); 1424 1425 /* The access to the per-CPU buffer srh_state is protected by running 1426 * always in softirq context (with disabled BH). On PREEMPT_RT the 1427 * required locking is provided by the following local_lock_nested_bh() 1428 * statement. It is also accessed by the bpf_lwt_seg6_* helpers via 1429 * bpf_prog_run_save_cb(). 1430 */ 1431 local_lock_nested_bh(&seg6_bpf_srh_states.bh_lock); 1432 srh_state = this_cpu_ptr(&seg6_bpf_srh_states); 1433 srh_state->srh = srh; 1434 srh_state->hdrlen = srh->hdrlen << 3; 1435 srh_state->valid = true; 1436 1437 rcu_read_lock(); 1438 bpf_compute_data_pointers(skb); 1439 ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb); 1440 rcu_read_unlock(); 1441 1442 switch (ret) { 1443 case BPF_OK: 1444 case BPF_REDIRECT: 1445 break; 1446 case BPF_DROP: 1447 goto drop; 1448 default: 1449 pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret); 1450 goto drop; 1451 } 1452 1453 if (srh_state->srh && !seg6_bpf_has_valid_srh(skb)) 1454 goto drop; 1455 local_unlock_nested_bh(&seg6_bpf_srh_states.bh_lock); 1456 1457 if (ret != BPF_REDIRECT) 1458 seg6_lookup_nexthop(skb, NULL, 0); 1459 1460 return dst_input(skb); 1461 1462 drop: 1463 local_unlock_nested_bh(&seg6_bpf_srh_states.bh_lock); 1464 kfree_skb(skb); 1465 return -EINVAL; 1466 } 1467 1468 static struct seg6_action_desc seg6_action_table[] = { 1469 { 1470 .action = SEG6_LOCAL_ACTION_END, 1471 .attrs = 0, 1472 .optattrs = SEG6_F_LOCAL_COUNTERS | 1473 SEG6_F_LOCAL_FLAVORS, 1474 .input = input_action_end, 1475 }, 1476 { 1477 .action = SEG6_LOCAL_ACTION_END_X, 1478 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6), 1479 .optattrs = SEG6_F_LOCAL_COUNTERS | 1480 SEG6_F_LOCAL_FLAVORS, 1481 .input = input_action_end_x, 1482 }, 1483 { 1484 .action = SEG6_LOCAL_ACTION_END_T, 1485 .attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE), 1486 .optattrs = SEG6_F_LOCAL_COUNTERS, 1487 .input = input_action_end_t, 1488 }, 1489 { 1490 .action = SEG6_LOCAL_ACTION_END_DX2, 1491 .attrs = SEG6_F_ATTR(SEG6_LOCAL_OIF), 1492 .optattrs = SEG6_F_LOCAL_COUNTERS, 1493 .input = input_action_end_dx2, 1494 }, 1495 { 1496 .action = SEG6_LOCAL_ACTION_END_DX6, 1497 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6), 1498 .optattrs = SEG6_F_LOCAL_COUNTERS, 1499 .input = input_action_end_dx6, 1500 }, 1501 { 1502 .action = SEG6_LOCAL_ACTION_END_DX4, 1503 .attrs = SEG6_F_ATTR(SEG6_LOCAL_NH4), 1504 .optattrs = SEG6_F_LOCAL_COUNTERS, 1505 .input = input_action_end_dx4, 1506 }, 1507 { 1508 .action = SEG6_LOCAL_ACTION_END_DT4, 1509 .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1510 .optattrs = SEG6_F_LOCAL_COUNTERS, 1511 #ifdef CONFIG_NET_L3_MASTER_DEV 1512 .input = input_action_end_dt4, 1513 .slwt_ops = { 1514 .build_state = seg6_end_dt4_build, 1515 }, 1516 #endif 1517 }, 1518 { 1519 .action = SEG6_LOCAL_ACTION_END_DT6, 1520 #ifdef CONFIG_NET_L3_MASTER_DEV 1521 .attrs = 0, 1522 .optattrs = SEG6_F_LOCAL_COUNTERS | 1523 SEG6_F_ATTR(SEG6_LOCAL_TABLE) | 1524 SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1525 .slwt_ops = { 1526 .build_state = seg6_end_dt6_build, 1527 }, 1528 #else 1529 .attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE), 1530 .optattrs = SEG6_F_LOCAL_COUNTERS, 1531 #endif 1532 .input = input_action_end_dt6, 1533 }, 1534 { 1535 .action = SEG6_LOCAL_ACTION_END_DT46, 1536 .attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE), 1537 .optattrs = SEG6_F_LOCAL_COUNTERS, 1538 #ifdef CONFIG_NET_L3_MASTER_DEV 1539 .input = input_action_end_dt46, 1540 .slwt_ops = { 1541 .build_state = seg6_end_dt46_build, 1542 }, 1543 #endif 1544 }, 1545 { 1546 .action = SEG6_LOCAL_ACTION_END_B6, 1547 .attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH), 1548 .optattrs = SEG6_F_LOCAL_COUNTERS, 1549 .input = input_action_end_b6, 1550 }, 1551 { 1552 .action = SEG6_LOCAL_ACTION_END_B6_ENCAP, 1553 .attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH), 1554 .optattrs = SEG6_F_LOCAL_COUNTERS, 1555 .input = input_action_end_b6_encap, 1556 .static_headroom = sizeof(struct ipv6hdr), 1557 }, 1558 { 1559 .action = SEG6_LOCAL_ACTION_END_BPF, 1560 .attrs = SEG6_F_ATTR(SEG6_LOCAL_BPF), 1561 .optattrs = SEG6_F_LOCAL_COUNTERS, 1562 .input = input_action_end_bpf, 1563 }, 1564 1565 }; 1566 1567 static struct seg6_action_desc *__get_action_desc(int action) 1568 { 1569 struct seg6_action_desc *desc; 1570 int i, count; 1571 1572 count = ARRAY_SIZE(seg6_action_table); 1573 for (i = 0; i < count; i++) { 1574 desc = &seg6_action_table[i]; 1575 if (desc->action == action) 1576 return desc; 1577 } 1578 1579 return NULL; 1580 } 1581 1582 static bool seg6_lwtunnel_counters_enabled(struct seg6_local_lwt *slwt) 1583 { 1584 return slwt->parsed_optattrs & SEG6_F_LOCAL_COUNTERS; 1585 } 1586 1587 static void seg6_local_update_counters(struct seg6_local_lwt *slwt, 1588 unsigned int len, int err) 1589 { 1590 struct pcpu_seg6_local_counters *pcounters; 1591 1592 pcounters = this_cpu_ptr(slwt->pcpu_counters); 1593 u64_stats_update_begin(&pcounters->syncp); 1594 1595 if (likely(!err)) { 1596 u64_stats_inc(&pcounters->packets); 1597 u64_stats_add(&pcounters->bytes, len); 1598 } else { 1599 u64_stats_inc(&pcounters->errors); 1600 } 1601 1602 u64_stats_update_end(&pcounters->syncp); 1603 } 1604 1605 static int seg6_local_input_core(struct net *net, struct sock *sk, 1606 struct sk_buff *skb) 1607 { 1608 struct dst_entry *orig_dst = skb_dst(skb); 1609 struct seg6_action_desc *desc; 1610 struct seg6_local_lwt *slwt; 1611 unsigned int len = skb->len; 1612 int rc; 1613 1614 slwt = seg6_local_lwtunnel(orig_dst->lwtstate); 1615 desc = slwt->desc; 1616 1617 rc = desc->input(skb, slwt); 1618 1619 if (!seg6_lwtunnel_counters_enabled(slwt)) 1620 return rc; 1621 1622 seg6_local_update_counters(slwt, len, rc); 1623 1624 return rc; 1625 } 1626 1627 static int seg6_local_input(struct sk_buff *skb) 1628 { 1629 if (skb->protocol != htons(ETH_P_IPV6)) { 1630 kfree_skb(skb); 1631 return -EINVAL; 1632 } 1633 1634 if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) 1635 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, 1636 dev_net(skb->dev), NULL, skb, skb->dev, NULL, 1637 seg6_local_input_core); 1638 1639 return seg6_local_input_core(dev_net(skb->dev), NULL, skb); 1640 } 1641 1642 static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = { 1643 [SEG6_LOCAL_ACTION] = { .type = NLA_U32 }, 1644 [SEG6_LOCAL_SRH] = { .type = NLA_BINARY }, 1645 [SEG6_LOCAL_TABLE] = { .type = NLA_U32 }, 1646 [SEG6_LOCAL_VRFTABLE] = { .type = NLA_U32 }, 1647 [SEG6_LOCAL_NH4] = { .type = NLA_BINARY, 1648 .len = sizeof(struct in_addr) }, 1649 [SEG6_LOCAL_NH6] = { .type = NLA_BINARY, 1650 .len = sizeof(struct in6_addr) }, 1651 [SEG6_LOCAL_IIF] = { .type = NLA_U32 }, 1652 [SEG6_LOCAL_OIF] = { .type = NLA_U32 }, 1653 [SEG6_LOCAL_BPF] = { .type = NLA_NESTED }, 1654 [SEG6_LOCAL_COUNTERS] = { .type = NLA_NESTED }, 1655 [SEG6_LOCAL_FLAVORS] = { .type = NLA_NESTED }, 1656 }; 1657 1658 static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1659 struct netlink_ext_ack *extack) 1660 { 1661 struct ipv6_sr_hdr *srh; 1662 int len; 1663 1664 srh = nla_data(attrs[SEG6_LOCAL_SRH]); 1665 len = nla_len(attrs[SEG6_LOCAL_SRH]); 1666 1667 /* SRH must contain at least one segment */ 1668 if (len < sizeof(*srh) + sizeof(struct in6_addr)) 1669 return -EINVAL; 1670 1671 if (!seg6_validate_srh(srh, len, false)) 1672 return -EINVAL; 1673 1674 slwt->srh = kmemdup(srh, len, GFP_KERNEL); 1675 if (!slwt->srh) 1676 return -ENOMEM; 1677 1678 slwt->headroom += len; 1679 1680 return 0; 1681 } 1682 1683 static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1684 { 1685 struct ipv6_sr_hdr *srh; 1686 struct nlattr *nla; 1687 int len; 1688 1689 srh = slwt->srh; 1690 len = (srh->hdrlen + 1) << 3; 1691 1692 nla = nla_reserve(skb, SEG6_LOCAL_SRH, len); 1693 if (!nla) 1694 return -EMSGSIZE; 1695 1696 memcpy(nla_data(nla), srh, len); 1697 1698 return 0; 1699 } 1700 1701 static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1702 { 1703 int len = (a->srh->hdrlen + 1) << 3; 1704 1705 if (len != ((b->srh->hdrlen + 1) << 3)) 1706 return 1; 1707 1708 return memcmp(a->srh, b->srh, len); 1709 } 1710 1711 static void destroy_attr_srh(struct seg6_local_lwt *slwt) 1712 { 1713 kfree(slwt->srh); 1714 } 1715 1716 static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1717 struct netlink_ext_ack *extack) 1718 { 1719 slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]); 1720 1721 return 0; 1722 } 1723 1724 static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1725 { 1726 if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table)) 1727 return -EMSGSIZE; 1728 1729 return 0; 1730 } 1731 1732 static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1733 { 1734 if (a->table != b->table) 1735 return 1; 1736 1737 return 0; 1738 } 1739 1740 static struct 1741 seg6_end_dt_info *seg6_possible_end_dt_info(struct seg6_local_lwt *slwt) 1742 { 1743 #ifdef CONFIG_NET_L3_MASTER_DEV 1744 return &slwt->dt_info; 1745 #else 1746 return ERR_PTR(-EOPNOTSUPP); 1747 #endif 1748 } 1749 1750 static int parse_nla_vrftable(struct nlattr **attrs, 1751 struct seg6_local_lwt *slwt, 1752 struct netlink_ext_ack *extack) 1753 { 1754 struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt); 1755 1756 if (IS_ERR(info)) 1757 return PTR_ERR(info); 1758 1759 info->vrf_table = nla_get_u32(attrs[SEG6_LOCAL_VRFTABLE]); 1760 1761 return 0; 1762 } 1763 1764 static int put_nla_vrftable(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1765 { 1766 struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt); 1767 1768 if (IS_ERR(info)) 1769 return PTR_ERR(info); 1770 1771 if (nla_put_u32(skb, SEG6_LOCAL_VRFTABLE, info->vrf_table)) 1772 return -EMSGSIZE; 1773 1774 return 0; 1775 } 1776 1777 static int cmp_nla_vrftable(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1778 { 1779 struct seg6_end_dt_info *info_a = seg6_possible_end_dt_info(a); 1780 struct seg6_end_dt_info *info_b = seg6_possible_end_dt_info(b); 1781 1782 if (info_a->vrf_table != info_b->vrf_table) 1783 return 1; 1784 1785 return 0; 1786 } 1787 1788 static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1789 struct netlink_ext_ack *extack) 1790 { 1791 memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]), 1792 sizeof(struct in_addr)); 1793 1794 return 0; 1795 } 1796 1797 static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1798 { 1799 struct nlattr *nla; 1800 1801 nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr)); 1802 if (!nla) 1803 return -EMSGSIZE; 1804 1805 memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr)); 1806 1807 return 0; 1808 } 1809 1810 static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1811 { 1812 return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr)); 1813 } 1814 1815 static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1816 struct netlink_ext_ack *extack) 1817 { 1818 memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]), 1819 sizeof(struct in6_addr)); 1820 1821 return 0; 1822 } 1823 1824 static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1825 { 1826 struct nlattr *nla; 1827 1828 nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr)); 1829 if (!nla) 1830 return -EMSGSIZE; 1831 1832 memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr)); 1833 1834 return 0; 1835 } 1836 1837 static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1838 { 1839 return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr)); 1840 } 1841 1842 static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1843 struct netlink_ext_ack *extack) 1844 { 1845 slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]); 1846 1847 return 0; 1848 } 1849 1850 static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1851 { 1852 if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif)) 1853 return -EMSGSIZE; 1854 1855 return 0; 1856 } 1857 1858 static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1859 { 1860 if (a->iif != b->iif) 1861 return 1; 1862 1863 return 0; 1864 } 1865 1866 static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1867 struct netlink_ext_ack *extack) 1868 { 1869 slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]); 1870 1871 return 0; 1872 } 1873 1874 static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1875 { 1876 if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif)) 1877 return -EMSGSIZE; 1878 1879 return 0; 1880 } 1881 1882 static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1883 { 1884 if (a->oif != b->oif) 1885 return 1; 1886 1887 return 0; 1888 } 1889 1890 #define MAX_PROG_NAME 256 1891 static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = { 1892 [SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, }, 1893 [SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING, 1894 .len = MAX_PROG_NAME }, 1895 }; 1896 1897 static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt, 1898 struct netlink_ext_ack *extack) 1899 { 1900 struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1]; 1901 struct bpf_prog *p; 1902 int ret; 1903 u32 fd; 1904 1905 ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_BPF_PROG_MAX, 1906 attrs[SEG6_LOCAL_BPF], 1907 bpf_prog_policy, NULL); 1908 if (ret < 0) 1909 return ret; 1910 1911 if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME]) 1912 return -EINVAL; 1913 1914 slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL); 1915 if (!slwt->bpf.name) 1916 return -ENOMEM; 1917 1918 fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]); 1919 p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL); 1920 if (IS_ERR(p)) { 1921 kfree(slwt->bpf.name); 1922 return PTR_ERR(p); 1923 } 1924 1925 slwt->bpf.prog = p; 1926 return 0; 1927 } 1928 1929 static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt) 1930 { 1931 struct nlattr *nest; 1932 1933 if (!slwt->bpf.prog) 1934 return 0; 1935 1936 nest = nla_nest_start_noflag(skb, SEG6_LOCAL_BPF); 1937 if (!nest) 1938 return -EMSGSIZE; 1939 1940 if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id)) 1941 return -EMSGSIZE; 1942 1943 if (slwt->bpf.name && 1944 nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name)) 1945 return -EMSGSIZE; 1946 1947 return nla_nest_end(skb, nest); 1948 } 1949 1950 static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 1951 { 1952 if (!a->bpf.name && !b->bpf.name) 1953 return 0; 1954 1955 if (!a->bpf.name || !b->bpf.name) 1956 return 1; 1957 1958 return strcmp(a->bpf.name, b->bpf.name); 1959 } 1960 1961 static void destroy_attr_bpf(struct seg6_local_lwt *slwt) 1962 { 1963 kfree(slwt->bpf.name); 1964 if (slwt->bpf.prog) 1965 bpf_prog_put(slwt->bpf.prog); 1966 } 1967 1968 static const struct 1969 nla_policy seg6_local_counters_policy[SEG6_LOCAL_CNT_MAX + 1] = { 1970 [SEG6_LOCAL_CNT_PACKETS] = { .type = NLA_U64 }, 1971 [SEG6_LOCAL_CNT_BYTES] = { .type = NLA_U64 }, 1972 [SEG6_LOCAL_CNT_ERRORS] = { .type = NLA_U64 }, 1973 }; 1974 1975 static int parse_nla_counters(struct nlattr **attrs, 1976 struct seg6_local_lwt *slwt, 1977 struct netlink_ext_ack *extack) 1978 { 1979 struct pcpu_seg6_local_counters __percpu *pcounters; 1980 struct nlattr *tb[SEG6_LOCAL_CNT_MAX + 1]; 1981 int ret; 1982 1983 ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_CNT_MAX, 1984 attrs[SEG6_LOCAL_COUNTERS], 1985 seg6_local_counters_policy, NULL); 1986 if (ret < 0) 1987 return ret; 1988 1989 /* basic support for SRv6 Behavior counters requires at least: 1990 * packets, bytes and errors. 1991 */ 1992 if (!tb[SEG6_LOCAL_CNT_PACKETS] || !tb[SEG6_LOCAL_CNT_BYTES] || 1993 !tb[SEG6_LOCAL_CNT_ERRORS]) 1994 return -EINVAL; 1995 1996 /* counters are always zero initialized */ 1997 pcounters = seg6_local_alloc_pcpu_counters(GFP_KERNEL); 1998 if (!pcounters) 1999 return -ENOMEM; 2000 2001 slwt->pcpu_counters = pcounters; 2002 2003 return 0; 2004 } 2005 2006 static int seg6_local_fill_nla_counters(struct sk_buff *skb, 2007 struct seg6_local_counters *counters) 2008 { 2009 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_PACKETS, counters->packets, 2010 SEG6_LOCAL_CNT_PAD)) 2011 return -EMSGSIZE; 2012 2013 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_BYTES, counters->bytes, 2014 SEG6_LOCAL_CNT_PAD)) 2015 return -EMSGSIZE; 2016 2017 if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_ERRORS, counters->errors, 2018 SEG6_LOCAL_CNT_PAD)) 2019 return -EMSGSIZE; 2020 2021 return 0; 2022 } 2023 2024 static int put_nla_counters(struct sk_buff *skb, struct seg6_local_lwt *slwt) 2025 { 2026 struct seg6_local_counters counters = { 0, 0, 0 }; 2027 struct nlattr *nest; 2028 int rc, i; 2029 2030 nest = nla_nest_start(skb, SEG6_LOCAL_COUNTERS); 2031 if (!nest) 2032 return -EMSGSIZE; 2033 2034 for_each_possible_cpu(i) { 2035 struct pcpu_seg6_local_counters *pcounters; 2036 u64 packets, bytes, errors; 2037 unsigned int start; 2038 2039 pcounters = per_cpu_ptr(slwt->pcpu_counters, i); 2040 do { 2041 start = u64_stats_fetch_begin(&pcounters->syncp); 2042 2043 packets = u64_stats_read(&pcounters->packets); 2044 bytes = u64_stats_read(&pcounters->bytes); 2045 errors = u64_stats_read(&pcounters->errors); 2046 2047 } while (u64_stats_fetch_retry(&pcounters->syncp, start)); 2048 2049 counters.packets += packets; 2050 counters.bytes += bytes; 2051 counters.errors += errors; 2052 } 2053 2054 rc = seg6_local_fill_nla_counters(skb, &counters); 2055 if (rc < 0) { 2056 nla_nest_cancel(skb, nest); 2057 return rc; 2058 } 2059 2060 return nla_nest_end(skb, nest); 2061 } 2062 2063 static int cmp_nla_counters(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 2064 { 2065 /* a and b are equal if both have pcpu_counters set or not */ 2066 return (!!((unsigned long)a->pcpu_counters)) ^ 2067 (!!((unsigned long)b->pcpu_counters)); 2068 } 2069 2070 static void destroy_attr_counters(struct seg6_local_lwt *slwt) 2071 { 2072 free_percpu(slwt->pcpu_counters); 2073 } 2074 2075 static const 2076 struct nla_policy seg6_local_flavors_policy[SEG6_LOCAL_FLV_MAX + 1] = { 2077 [SEG6_LOCAL_FLV_OPERATION] = { .type = NLA_U32 }, 2078 [SEG6_LOCAL_FLV_LCBLOCK_BITS] = { .type = NLA_U8 }, 2079 [SEG6_LOCAL_FLV_LCNODE_FN_BITS] = { .type = NLA_U8 }, 2080 }; 2081 2082 /* check whether the lengths of the Locator-Block and Locator-Node Function 2083 * are compatible with the dimension of a C-SID container. 2084 */ 2085 static int seg6_chk_next_csid_cfg(__u8 block_len, __u8 func_len) 2086 { 2087 /* Locator-Block and Locator-Node Function cannot exceed 128 bits 2088 * (i.e. C-SID container lenghts). 2089 */ 2090 if (next_csid_chk_cntr_bits(block_len, func_len)) 2091 return -EINVAL; 2092 2093 /* Locator-Block length must be greater than zero and evenly divisible 2094 * by 8. There must be room for a Locator-Node Function, at least. 2095 */ 2096 if (next_csid_chk_lcblock_bits(block_len)) 2097 return -EINVAL; 2098 2099 /* Locator-Node Function length must be greater than zero and evenly 2100 * divisible by 8. There must be room for the Locator-Block. 2101 */ 2102 if (next_csid_chk_lcnode_fn_bits(func_len)) 2103 return -EINVAL; 2104 2105 return 0; 2106 } 2107 2108 static int seg6_parse_nla_next_csid_cfg(struct nlattr **tb, 2109 struct seg6_flavors_info *finfo, 2110 struct netlink_ext_ack *extack) 2111 { 2112 __u8 func_len = SEG6_LOCAL_LCNODE_FN_DBITS; 2113 __u8 block_len = SEG6_LOCAL_LCBLOCK_DBITS; 2114 int rc; 2115 2116 if (tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]) 2117 block_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]); 2118 2119 if (tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]) 2120 func_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]); 2121 2122 rc = seg6_chk_next_csid_cfg(block_len, func_len); 2123 if (rc < 0) { 2124 NL_SET_ERR_MSG(extack, 2125 "Invalid Locator Block/Node Function lengths"); 2126 return rc; 2127 } 2128 2129 finfo->lcblock_bits = block_len; 2130 finfo->lcnode_func_bits = func_len; 2131 2132 return 0; 2133 } 2134 2135 static int parse_nla_flavors(struct nlattr **attrs, struct seg6_local_lwt *slwt, 2136 struct netlink_ext_ack *extack) 2137 { 2138 struct seg6_flavors_info *finfo = &slwt->flv_info; 2139 struct nlattr *tb[SEG6_LOCAL_FLV_MAX + 1]; 2140 int action = slwt->action; 2141 __u32 fops, supp_fops; 2142 int rc; 2143 2144 rc = nla_parse_nested_deprecated(tb, SEG6_LOCAL_FLV_MAX, 2145 attrs[SEG6_LOCAL_FLAVORS], 2146 seg6_local_flavors_policy, NULL); 2147 if (rc < 0) 2148 return rc; 2149 2150 /* this attribute MUST always be present since it represents the Flavor 2151 * operation(s) to be carried out. 2152 */ 2153 if (!tb[SEG6_LOCAL_FLV_OPERATION]) 2154 return -EINVAL; 2155 2156 fops = nla_get_u32(tb[SEG6_LOCAL_FLV_OPERATION]); 2157 rc = seg6_flv_supp_ops_by_action(action, &supp_fops); 2158 if (rc < 0 || (fops & ~supp_fops)) { 2159 NL_SET_ERR_MSG(extack, "Unsupported Flavor operation(s)"); 2160 return -EOPNOTSUPP; 2161 } 2162 2163 finfo->flv_ops = fops; 2164 2165 if (seg6_next_csid_enabled(fops)) { 2166 /* Locator-Block and Locator-Node Function lengths can be 2167 * provided by the user space. Otherwise, default values are 2168 * applied. 2169 */ 2170 rc = seg6_parse_nla_next_csid_cfg(tb, finfo, extack); 2171 if (rc < 0) 2172 return rc; 2173 } 2174 2175 return 0; 2176 } 2177 2178 static int seg6_fill_nla_next_csid_cfg(struct sk_buff *skb, 2179 struct seg6_flavors_info *finfo) 2180 { 2181 if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCBLOCK_BITS, finfo->lcblock_bits)) 2182 return -EMSGSIZE; 2183 2184 if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCNODE_FN_BITS, 2185 finfo->lcnode_func_bits)) 2186 return -EMSGSIZE; 2187 2188 return 0; 2189 } 2190 2191 static int put_nla_flavors(struct sk_buff *skb, struct seg6_local_lwt *slwt) 2192 { 2193 struct seg6_flavors_info *finfo = &slwt->flv_info; 2194 __u32 fops = finfo->flv_ops; 2195 struct nlattr *nest; 2196 int rc; 2197 2198 nest = nla_nest_start(skb, SEG6_LOCAL_FLAVORS); 2199 if (!nest) 2200 return -EMSGSIZE; 2201 2202 if (nla_put_u32(skb, SEG6_LOCAL_FLV_OPERATION, fops)) { 2203 rc = -EMSGSIZE; 2204 goto err; 2205 } 2206 2207 if (seg6_next_csid_enabled(fops)) { 2208 rc = seg6_fill_nla_next_csid_cfg(skb, finfo); 2209 if (rc < 0) 2210 goto err; 2211 } 2212 2213 return nla_nest_end(skb, nest); 2214 2215 err: 2216 nla_nest_cancel(skb, nest); 2217 return rc; 2218 } 2219 2220 static int seg6_cmp_nla_next_csid_cfg(struct seg6_flavors_info *finfo_a, 2221 struct seg6_flavors_info *finfo_b) 2222 { 2223 if (finfo_a->lcblock_bits != finfo_b->lcblock_bits) 2224 return 1; 2225 2226 if (finfo_a->lcnode_func_bits != finfo_b->lcnode_func_bits) 2227 return 1; 2228 2229 return 0; 2230 } 2231 2232 static int cmp_nla_flavors(struct seg6_local_lwt *a, struct seg6_local_lwt *b) 2233 { 2234 struct seg6_flavors_info *finfo_a = &a->flv_info; 2235 struct seg6_flavors_info *finfo_b = &b->flv_info; 2236 2237 if (finfo_a->flv_ops != finfo_b->flv_ops) 2238 return 1; 2239 2240 if (seg6_next_csid_enabled(finfo_a->flv_ops)) { 2241 if (seg6_cmp_nla_next_csid_cfg(finfo_a, finfo_b)) 2242 return 1; 2243 } 2244 2245 return 0; 2246 } 2247 2248 static int encap_size_flavors(struct seg6_local_lwt *slwt) 2249 { 2250 struct seg6_flavors_info *finfo = &slwt->flv_info; 2251 int nlsize; 2252 2253 nlsize = nla_total_size(0) + /* nest SEG6_LOCAL_FLAVORS */ 2254 nla_total_size(4); /* SEG6_LOCAL_FLV_OPERATION */ 2255 2256 if (seg6_next_csid_enabled(finfo->flv_ops)) 2257 nlsize += nla_total_size(1) + /* SEG6_LOCAL_FLV_LCBLOCK_BITS */ 2258 nla_total_size(1); /* SEG6_LOCAL_FLV_LCNODE_FN_BITS */ 2259 2260 return nlsize; 2261 } 2262 2263 struct seg6_action_param { 2264 int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt, 2265 struct netlink_ext_ack *extack); 2266 int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt); 2267 int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b); 2268 2269 /* optional destroy() callback useful for releasing resources which 2270 * have been previously acquired in the corresponding parse() 2271 * function. 2272 */ 2273 void (*destroy)(struct seg6_local_lwt *slwt); 2274 }; 2275 2276 static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = { 2277 [SEG6_LOCAL_SRH] = { .parse = parse_nla_srh, 2278 .put = put_nla_srh, 2279 .cmp = cmp_nla_srh, 2280 .destroy = destroy_attr_srh }, 2281 2282 [SEG6_LOCAL_TABLE] = { .parse = parse_nla_table, 2283 .put = put_nla_table, 2284 .cmp = cmp_nla_table }, 2285 2286 [SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4, 2287 .put = put_nla_nh4, 2288 .cmp = cmp_nla_nh4 }, 2289 2290 [SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6, 2291 .put = put_nla_nh6, 2292 .cmp = cmp_nla_nh6 }, 2293 2294 [SEG6_LOCAL_IIF] = { .parse = parse_nla_iif, 2295 .put = put_nla_iif, 2296 .cmp = cmp_nla_iif }, 2297 2298 [SEG6_LOCAL_OIF] = { .parse = parse_nla_oif, 2299 .put = put_nla_oif, 2300 .cmp = cmp_nla_oif }, 2301 2302 [SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf, 2303 .put = put_nla_bpf, 2304 .cmp = cmp_nla_bpf, 2305 .destroy = destroy_attr_bpf }, 2306 2307 [SEG6_LOCAL_VRFTABLE] = { .parse = parse_nla_vrftable, 2308 .put = put_nla_vrftable, 2309 .cmp = cmp_nla_vrftable }, 2310 2311 [SEG6_LOCAL_COUNTERS] = { .parse = parse_nla_counters, 2312 .put = put_nla_counters, 2313 .cmp = cmp_nla_counters, 2314 .destroy = destroy_attr_counters }, 2315 2316 [SEG6_LOCAL_FLAVORS] = { .parse = parse_nla_flavors, 2317 .put = put_nla_flavors, 2318 .cmp = cmp_nla_flavors }, 2319 }; 2320 2321 /* call the destroy() callback (if available) for each set attribute in 2322 * @parsed_attrs, starting from the first attribute up to the @max_parsed 2323 * (excluded) attribute. 2324 */ 2325 static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed, 2326 struct seg6_local_lwt *slwt) 2327 { 2328 struct seg6_action_param *param; 2329 int i; 2330 2331 /* Every required seg6local attribute is identified by an ID which is 2332 * encoded as a flag (i.e: 1 << ID) in the 'attrs' bitmask; 2333 * 2334 * We scan the 'parsed_attrs' bitmask, starting from the first attribute 2335 * up to the @max_parsed (excluded) attribute. 2336 * For each set attribute, we retrieve the corresponding destroy() 2337 * callback. If the callback is not available, then we skip to the next 2338 * attribute; otherwise, we call the destroy() callback. 2339 */ 2340 for (i = SEG6_LOCAL_SRH; i < max_parsed; ++i) { 2341 if (!(parsed_attrs & SEG6_F_ATTR(i))) 2342 continue; 2343 2344 param = &seg6_action_params[i]; 2345 2346 if (param->destroy) 2347 param->destroy(slwt); 2348 } 2349 } 2350 2351 /* release all the resources that may have been acquired during parsing 2352 * operations. 2353 */ 2354 static void destroy_attrs(struct seg6_local_lwt *slwt) 2355 { 2356 unsigned long attrs = slwt->desc->attrs | slwt->parsed_optattrs; 2357 2358 __destroy_attrs(attrs, SEG6_LOCAL_MAX + 1, slwt); 2359 } 2360 2361 static int parse_nla_optional_attrs(struct nlattr **attrs, 2362 struct seg6_local_lwt *slwt, 2363 struct netlink_ext_ack *extack) 2364 { 2365 struct seg6_action_desc *desc = slwt->desc; 2366 unsigned long parsed_optattrs = 0; 2367 struct seg6_action_param *param; 2368 int err, i; 2369 2370 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; ++i) { 2371 if (!(desc->optattrs & SEG6_F_ATTR(i)) || !attrs[i]) 2372 continue; 2373 2374 /* once here, the i-th attribute is provided by the 2375 * userspace AND it is identified optional as well. 2376 */ 2377 param = &seg6_action_params[i]; 2378 2379 err = param->parse(attrs, slwt, extack); 2380 if (err < 0) 2381 goto parse_optattrs_err; 2382 2383 /* current attribute has been correctly parsed */ 2384 parsed_optattrs |= SEG6_F_ATTR(i); 2385 } 2386 2387 /* store in the tunnel state all the optional attributed successfully 2388 * parsed. 2389 */ 2390 slwt->parsed_optattrs = parsed_optattrs; 2391 2392 return 0; 2393 2394 parse_optattrs_err: 2395 __destroy_attrs(parsed_optattrs, i, slwt); 2396 2397 return err; 2398 } 2399 2400 /* call the custom constructor of the behavior during its initialization phase 2401 * and after that all its attributes have been parsed successfully. 2402 */ 2403 static int 2404 seg6_local_lwtunnel_build_state(struct seg6_local_lwt *slwt, const void *cfg, 2405 struct netlink_ext_ack *extack) 2406 { 2407 struct seg6_action_desc *desc = slwt->desc; 2408 struct seg6_local_lwtunnel_ops *ops; 2409 2410 ops = &desc->slwt_ops; 2411 if (!ops->build_state) 2412 return 0; 2413 2414 return ops->build_state(slwt, cfg, extack); 2415 } 2416 2417 /* call the custom destructor of the behavior which is invoked before the 2418 * tunnel is going to be destroyed. 2419 */ 2420 static void seg6_local_lwtunnel_destroy_state(struct seg6_local_lwt *slwt) 2421 { 2422 struct seg6_action_desc *desc = slwt->desc; 2423 struct seg6_local_lwtunnel_ops *ops; 2424 2425 ops = &desc->slwt_ops; 2426 if (!ops->destroy_state) 2427 return; 2428 2429 ops->destroy_state(slwt); 2430 } 2431 2432 static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt, 2433 struct netlink_ext_ack *extack) 2434 { 2435 struct seg6_action_param *param; 2436 struct seg6_action_desc *desc; 2437 unsigned long invalid_attrs; 2438 int i, err; 2439 2440 desc = __get_action_desc(slwt->action); 2441 if (!desc) 2442 return -EINVAL; 2443 2444 if (!desc->input) 2445 return -EOPNOTSUPP; 2446 2447 slwt->desc = desc; 2448 slwt->headroom += desc->static_headroom; 2449 2450 /* Forcing the desc->optattrs *set* and the desc->attrs *set* to be 2451 * disjoined, this allow us to release acquired resources by optional 2452 * attributes and by required attributes independently from each other 2453 * without any interference. 2454 * In other terms, we are sure that we do not release some the acquired 2455 * resources twice. 2456 * 2457 * Note that if an attribute is configured both as required and as 2458 * optional, it means that the user has messed something up in the 2459 * seg6_action_table. Therefore, this check is required for SRv6 2460 * behaviors to work properly. 2461 */ 2462 invalid_attrs = desc->attrs & desc->optattrs; 2463 if (invalid_attrs) { 2464 WARN_ONCE(1, 2465 "An attribute cannot be both required AND optional"); 2466 return -EINVAL; 2467 } 2468 2469 /* parse the required attributes */ 2470 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2471 if (desc->attrs & SEG6_F_ATTR(i)) { 2472 if (!attrs[i]) 2473 return -EINVAL; 2474 2475 param = &seg6_action_params[i]; 2476 2477 err = param->parse(attrs, slwt, extack); 2478 if (err < 0) 2479 goto parse_attrs_err; 2480 } 2481 } 2482 2483 /* parse the optional attributes, if any */ 2484 err = parse_nla_optional_attrs(attrs, slwt, extack); 2485 if (err < 0) 2486 goto parse_attrs_err; 2487 2488 return 0; 2489 2490 parse_attrs_err: 2491 /* release any resource that may have been acquired during the i-1 2492 * parse() operations. 2493 */ 2494 __destroy_attrs(desc->attrs, i, slwt); 2495 2496 return err; 2497 } 2498 2499 static int seg6_local_build_state(struct net *net, struct nlattr *nla, 2500 unsigned int family, const void *cfg, 2501 struct lwtunnel_state **ts, 2502 struct netlink_ext_ack *extack) 2503 { 2504 struct nlattr *tb[SEG6_LOCAL_MAX + 1]; 2505 struct lwtunnel_state *newts; 2506 struct seg6_local_lwt *slwt; 2507 int err; 2508 2509 if (family != AF_INET6) 2510 return -EINVAL; 2511 2512 err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla, 2513 seg6_local_policy, extack); 2514 2515 if (err < 0) 2516 return err; 2517 2518 if (!tb[SEG6_LOCAL_ACTION]) 2519 return -EINVAL; 2520 2521 newts = lwtunnel_state_alloc(sizeof(*slwt)); 2522 if (!newts) 2523 return -ENOMEM; 2524 2525 slwt = seg6_local_lwtunnel(newts); 2526 slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]); 2527 2528 err = parse_nla_action(tb, slwt, extack); 2529 if (err < 0) 2530 goto out_free; 2531 2532 err = seg6_local_lwtunnel_build_state(slwt, cfg, extack); 2533 if (err < 0) 2534 goto out_destroy_attrs; 2535 2536 newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL; 2537 newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT; 2538 newts->headroom = slwt->headroom; 2539 2540 *ts = newts; 2541 2542 return 0; 2543 2544 out_destroy_attrs: 2545 destroy_attrs(slwt); 2546 out_free: 2547 kfree(newts); 2548 return err; 2549 } 2550 2551 static void seg6_local_destroy_state(struct lwtunnel_state *lwt) 2552 { 2553 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2554 2555 seg6_local_lwtunnel_destroy_state(slwt); 2556 2557 destroy_attrs(slwt); 2558 2559 return; 2560 } 2561 2562 static int seg6_local_fill_encap(struct sk_buff *skb, 2563 struct lwtunnel_state *lwt) 2564 { 2565 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2566 struct seg6_action_param *param; 2567 unsigned long attrs; 2568 int i, err; 2569 2570 if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action)) 2571 return -EMSGSIZE; 2572 2573 attrs = slwt->desc->attrs | slwt->parsed_optattrs; 2574 2575 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2576 if (attrs & SEG6_F_ATTR(i)) { 2577 param = &seg6_action_params[i]; 2578 err = param->put(skb, slwt); 2579 if (err < 0) 2580 return err; 2581 } 2582 } 2583 2584 return 0; 2585 } 2586 2587 static int seg6_local_get_encap_size(struct lwtunnel_state *lwt) 2588 { 2589 struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt); 2590 unsigned long attrs; 2591 int nlsize; 2592 2593 nlsize = nla_total_size(4); /* action */ 2594 2595 attrs = slwt->desc->attrs | slwt->parsed_optattrs; 2596 2597 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_SRH)) 2598 nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3); 2599 2600 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE)) 2601 nlsize += nla_total_size(4); 2602 2603 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH4)) 2604 nlsize += nla_total_size(4); 2605 2606 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH6)) 2607 nlsize += nla_total_size(16); 2608 2609 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_IIF)) 2610 nlsize += nla_total_size(4); 2611 2612 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_OIF)) 2613 nlsize += nla_total_size(4); 2614 2615 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_BPF)) 2616 nlsize += nla_total_size(sizeof(struct nlattr)) + 2617 nla_total_size(MAX_PROG_NAME) + 2618 nla_total_size(4); 2619 2620 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE)) 2621 nlsize += nla_total_size(4); 2622 2623 if (attrs & SEG6_F_LOCAL_COUNTERS) 2624 nlsize += nla_total_size(0) + /* nest SEG6_LOCAL_COUNTERS */ 2625 /* SEG6_LOCAL_CNT_PACKETS */ 2626 nla_total_size_64bit(sizeof(__u64)) + 2627 /* SEG6_LOCAL_CNT_BYTES */ 2628 nla_total_size_64bit(sizeof(__u64)) + 2629 /* SEG6_LOCAL_CNT_ERRORS */ 2630 nla_total_size_64bit(sizeof(__u64)); 2631 2632 if (attrs & SEG6_F_ATTR(SEG6_LOCAL_FLAVORS)) 2633 nlsize += encap_size_flavors(slwt); 2634 2635 return nlsize; 2636 } 2637 2638 static int seg6_local_cmp_encap(struct lwtunnel_state *a, 2639 struct lwtunnel_state *b) 2640 { 2641 struct seg6_local_lwt *slwt_a, *slwt_b; 2642 struct seg6_action_param *param; 2643 unsigned long attrs_a, attrs_b; 2644 int i; 2645 2646 slwt_a = seg6_local_lwtunnel(a); 2647 slwt_b = seg6_local_lwtunnel(b); 2648 2649 if (slwt_a->action != slwt_b->action) 2650 return 1; 2651 2652 attrs_a = slwt_a->desc->attrs | slwt_a->parsed_optattrs; 2653 attrs_b = slwt_b->desc->attrs | slwt_b->parsed_optattrs; 2654 2655 if (attrs_a != attrs_b) 2656 return 1; 2657 2658 for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) { 2659 if (attrs_a & SEG6_F_ATTR(i)) { 2660 param = &seg6_action_params[i]; 2661 if (param->cmp(slwt_a, slwt_b)) 2662 return 1; 2663 } 2664 } 2665 2666 return 0; 2667 } 2668 2669 static const struct lwtunnel_encap_ops seg6_local_ops = { 2670 .build_state = seg6_local_build_state, 2671 .destroy_state = seg6_local_destroy_state, 2672 .input = seg6_local_input, 2673 .fill_encap = seg6_local_fill_encap, 2674 .get_encap_size = seg6_local_get_encap_size, 2675 .cmp_encap = seg6_local_cmp_encap, 2676 .owner = THIS_MODULE, 2677 }; 2678 2679 int __init seg6_local_init(void) 2680 { 2681 /* If the max total number of defined attributes is reached, then your 2682 * kernel build stops here. 2683 * 2684 * This check is required to avoid arithmetic overflows when processing 2685 * behavior attributes and the maximum number of defined attributes 2686 * exceeds the allowed value. 2687 */ 2688 BUILD_BUG_ON(SEG6_LOCAL_MAX + 1 > BITS_PER_TYPE(unsigned long)); 2689 2690 /* Check whether the number of defined flavors exceeds the maximum 2691 * allowed value. 2692 */ 2693 BUILD_BUG_ON(SEG6_LOCAL_FLV_OP_MAX + 1 > BITS_PER_TYPE(__u32)); 2694 2695 /* If the default NEXT-C-SID Locator-Block/Node Function lengths (in 2696 * bits) have been changed with invalid values, kernel build stops 2697 * here. 2698 */ 2699 BUILD_BUG_ON(next_csid_chk_cntr_bits(SEG6_LOCAL_LCBLOCK_DBITS, 2700 SEG6_LOCAL_LCNODE_FN_DBITS)); 2701 BUILD_BUG_ON(next_csid_chk_lcblock_bits(SEG6_LOCAL_LCBLOCK_DBITS)); 2702 BUILD_BUG_ON(next_csid_chk_lcnode_fn_bits(SEG6_LOCAL_LCNODE_FN_DBITS)); 2703 2704 /* To be memory efficient, we use 'u8' to represent the different 2705 * actions related to RFC8986 flavors. If the kernel build stops here, 2706 * it means that it is not possible to correctly encode these actions 2707 * with the data type chosen for the action table. 2708 */ 2709 BUILD_BUG_ON(SEG6_LOCAL_FLV_ACT_MAX > (typeof(flv8986_act_tbl[0]))~0U); 2710 2711 return lwtunnel_encap_add_ops(&seg6_local_ops, 2712 LWTUNNEL_ENCAP_SEG6_LOCAL); 2713 } 2714 2715 void seg6_local_exit(void) 2716 { 2717 lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL); 2718 } 2719