| 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* |
| 3 | * Internet Control Message Protocol (ICMPv6) |
| 4 | * Linux INET6 implementation |
| 5 | * |
| 6 | * Authors: |
| 7 | * Pedro Roque <roque@di.fc.ul.pt> |
| 8 | * |
| 9 | * Based on net/ipv4/icmp.c |
| 10 | * |
| 11 | * RFC 1885 |
| 12 | */ |
| 13 | |
| 14 | /* |
| 15 | * Changes: |
| 16 | * |
| 17 | * Andi Kleen : exception handling |
| 18 | * Andi Kleen add rate limits. never reply to a icmp. |
| 19 | * add more length checks and other fixes. |
| 20 | * yoshfuji : ensure to sent parameter problem for |
| 21 | * fragments. |
| 22 | * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit. |
| 23 | * Randy Dunlap and |
| 24 | * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support |
| 25 | * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data |
| 26 | */ |
| 27 | |
| 28 | #define pr_fmt(fmt) "IPv6: " fmt |
| 29 | |
| 30 | #include <linux/module.h> |
| 31 | #include <linux/errno.h> |
| 32 | #include <linux/types.h> |
| 33 | #include <linux/socket.h> |
| 34 | #include <linux/in.h> |
| 35 | #include <linux/kernel.h> |
| 36 | #include <linux/sockios.h> |
| 37 | #include <linux/net.h> |
| 38 | #include <linux/skbuff.h> |
| 39 | #include <linux/init.h> |
| 40 | #include <linux/netfilter.h> |
| 41 | #include <linux/slab.h> |
| 42 | |
| 43 | #ifdef CONFIG_SYSCTL |
| 44 | #include <linux/sysctl.h> |
| 45 | #endif |
| 46 | |
| 47 | #include <linux/inet.h> |
| 48 | #include <linux/netdevice.h> |
| 49 | #include <linux/icmpv6.h> |
| 50 | |
| 51 | #include <net/ip.h> |
| 52 | #include <net/sock.h> |
| 53 | |
| 54 | #include <net/ipv6.h> |
| 55 | #include <net/ip6_checksum.h> |
| 56 | #include <net/ping.h> |
| 57 | #include <net/protocol.h> |
| 58 | #include <net/raw.h> |
| 59 | #include <net/rawv6.h> |
| 60 | #include <net/seg6.h> |
| 61 | #include <net/transp_v6.h> |
| 62 | #include <net/ip6_route.h> |
| 63 | #include <net/addrconf.h> |
| 64 | #include <net/icmp.h> |
| 65 | #include <net/xfrm.h> |
| 66 | #include <net/inet_common.h> |
| 67 | #include <net/dsfield.h> |
| 68 | #include <net/l3mdev.h> |
| 69 | |
| 70 | #include <linux/uaccess.h> |
| 71 | |
| 72 | static DEFINE_PER_CPU(struct sock *, ipv6_icmp_sk); |
| 73 | |
| 74 | static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
| 75 | u8 type, u8 code, int offset, __be32 info) |
| 76 | { |
| 77 | /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */ |
| 78 | struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset); |
| 79 | struct net *net = dev_net_rcu(skb->dev); |
| 80 | |
| 81 | if (type == ICMPV6_PKT_TOOBIG) |
| 82 | ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL)); |
| 83 | else if (type == NDISC_REDIRECT) |
| 84 | ip6_redirect(skb, net, skb->dev->ifindex, 0, |
| 85 | sock_net_uid(net, NULL)); |
| 86 | |
| 87 | if (!(type & ICMPV6_INFOMSG_MASK)) |
| 88 | if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST) |
| 89 | ping_err(skb, offset, ntohl(info)); |
| 90 | |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | static int icmpv6_rcv(struct sk_buff *skb); |
| 95 | |
| 96 | static const struct inet6_protocol icmpv6_protocol = { |
| 97 | .handler = icmpv6_rcv, |
| 98 | .err_handler = icmpv6_err, |
| 99 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
| 100 | }; |
| 101 | |
| 102 | /* Called with BH disabled */ |
| 103 | static struct sock *icmpv6_xmit_lock(struct net *net) |
| 104 | { |
| 105 | struct sock *sk; |
| 106 | |
| 107 | sk = this_cpu_read(ipv6_icmp_sk); |
| 108 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
| 109 | /* This can happen if the output path (f.e. SIT or |
| 110 | * ip6ip6 tunnel) signals dst_link_failure() for an |
| 111 | * outgoing ICMP6 packet. |
| 112 | */ |
| 113 | return NULL; |
| 114 | } |
| 115 | sock_net_set(sk, net); |
| 116 | return sk; |
| 117 | } |
| 118 | |
| 119 | static void icmpv6_xmit_unlock(struct sock *sk) |
| 120 | { |
| 121 | sock_net_set(sk, &init_net); |
| 122 | spin_unlock(&sk->sk_lock.slock); |
| 123 | } |
| 124 | |
| 125 | /* |
| 126 | * Figure out, may we reply to this packet with icmp error. |
| 127 | * |
| 128 | * We do not reply, if: |
| 129 | * - it was icmp error message. |
| 130 | * - it is truncated, so that it is known, that protocol is ICMPV6 |
| 131 | * (i.e. in the middle of some exthdr) |
| 132 | * |
| 133 | * --ANK (980726) |
| 134 | */ |
| 135 | |
| 136 | static bool is_ineligible(const struct sk_buff *skb) |
| 137 | { |
| 138 | int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; |
| 139 | int len = skb->len - ptr; |
| 140 | __u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
| 141 | __be16 frag_off; |
| 142 | |
| 143 | if (len < 0) |
| 144 | return true; |
| 145 | |
| 146 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off); |
| 147 | if (ptr < 0) |
| 148 | return false; |
| 149 | if (nexthdr == IPPROTO_ICMPV6) { |
| 150 | u8 _type, *tp; |
| 151 | tp = skb_header_pointer(skb, |
| 152 | ptr+offsetof(struct icmp6hdr, icmp6_type), |
| 153 | sizeof(_type), &_type); |
| 154 | |
| 155 | /* Based on RFC 8200, Section 4.5 Fragment Header, return |
| 156 | * false if this is a fragment packet with no icmp header info. |
| 157 | */ |
| 158 | if (!tp && frag_off != 0) |
| 159 | return false; |
| 160 | else if (!tp || !(*tp & ICMPV6_INFOMSG_MASK)) |
| 161 | return true; |
| 162 | } |
| 163 | return false; |
| 164 | } |
| 165 | |
| 166 | static bool icmpv6_mask_allow(struct net *net, int type) |
| 167 | { |
| 168 | if (type > ICMPV6_MSG_MAX) |
| 169 | return true; |
| 170 | |
| 171 | /* Limit if icmp type is set in ratemask. */ |
| 172 | if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask)) |
| 173 | return true; |
| 174 | |
| 175 | return false; |
| 176 | } |
| 177 | |
| 178 | static bool icmpv6_global_allow(struct net *net, int type, |
| 179 | bool *apply_ratelimit) |
| 180 | { |
| 181 | if (icmpv6_mask_allow(net, type)) |
| 182 | return true; |
| 183 | |
| 184 | if (icmp_global_allow(net)) { |
| 185 | *apply_ratelimit = true; |
| 186 | return true; |
| 187 | } |
| 188 | __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL); |
| 189 | return false; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Check the ICMP output rate limit |
| 194 | */ |
| 195 | static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, |
| 196 | struct flowi6 *fl6, bool apply_ratelimit) |
| 197 | { |
| 198 | struct net *net = sock_net(sk); |
| 199 | struct dst_entry *dst; |
| 200 | bool res = false; |
| 201 | |
| 202 | if (!apply_ratelimit) |
| 203 | return true; |
| 204 | |
| 205 | /* |
| 206 | * Look up the output route. |
| 207 | * XXX: perhaps the expire for routing entries cloned by |
| 208 | * this lookup should be more aggressive (not longer than timeout). |
| 209 | */ |
| 210 | dst = ip6_route_output(net, sk, fl6); |
| 211 | if (dst->error) { |
| 212 | IP6_INC_STATS(net, ip6_dst_idev(dst), |
| 213 | IPSTATS_MIB_OUTNOROUTES); |
| 214 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
| 215 | res = true; |
| 216 | } else { |
| 217 | struct rt6_info *rt = dst_rt6_info(dst); |
| 218 | int tmo = net->ipv6.sysctl.icmpv6_time; |
| 219 | struct inet_peer *peer; |
| 220 | |
| 221 | /* Give more bandwidth to wider prefixes. */ |
| 222 | if (rt->rt6i_dst.plen < 128) |
| 223 | tmo >>= ((128 - rt->rt6i_dst.plen)>>5); |
| 224 | |
| 225 | rcu_read_lock(); |
| 226 | peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr); |
| 227 | res = inet_peer_xrlim_allow(peer, tmo); |
| 228 | rcu_read_unlock(); |
| 229 | } |
| 230 | if (!res) |
| 231 | __ICMP6_INC_STATS(net, ip6_dst_idev(dst), |
| 232 | ICMP6_MIB_RATELIMITHOST); |
| 233 | else |
| 234 | icmp_global_consume(net); |
| 235 | dst_release(dst); |
| 236 | return res; |
| 237 | } |
| 238 | |
| 239 | static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type, |
| 240 | struct flowi6 *fl6) |
| 241 | { |
| 242 | struct net *net = sock_net(sk); |
| 243 | struct dst_entry *dst; |
| 244 | bool res = false; |
| 245 | |
| 246 | dst = ip6_route_output(net, sk, fl6); |
| 247 | if (!dst->error) { |
| 248 | struct rt6_info *rt = dst_rt6_info(dst); |
| 249 | struct in6_addr prefsrc; |
| 250 | |
| 251 | rt6_get_prefsrc(rt, &prefsrc); |
| 252 | res = !ipv6_addr_any(&prefsrc); |
| 253 | } |
| 254 | dst_release(dst); |
| 255 | return res; |
| 256 | } |
| 257 | |
| 258 | /* |
| 259 | * an inline helper for the "simple" if statement below |
| 260 | * checks if parameter problem report is caused by an |
| 261 | * unrecognized IPv6 option that has the Option Type |
| 262 | * highest-order two bits set to 10 |
| 263 | */ |
| 264 | |
| 265 | static bool opt_unrec(struct sk_buff *skb, __u32 offset) |
| 266 | { |
| 267 | u8 _optval, *op; |
| 268 | |
| 269 | offset += skb_network_offset(skb); |
| 270 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
| 271 | if (!op) |
| 272 | return true; |
| 273 | return (*op & 0xC0) == 0x80; |
| 274 | } |
| 275 | |
| 276 | void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, |
| 277 | struct icmp6hdr *thdr, int len) |
| 278 | { |
| 279 | struct sk_buff *skb; |
| 280 | struct icmp6hdr *icmp6h; |
| 281 | |
| 282 | skb = skb_peek(&sk->sk_write_queue); |
| 283 | if (!skb) |
| 284 | return; |
| 285 | |
| 286 | icmp6h = icmp6_hdr(skb); |
| 287 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
| 288 | icmp6h->icmp6_cksum = 0; |
| 289 | |
| 290 | if (skb_queue_len(&sk->sk_write_queue) == 1) { |
| 291 | skb->csum = csum_partial(icmp6h, |
| 292 | sizeof(struct icmp6hdr), skb->csum); |
| 293 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
| 294 | &fl6->daddr, |
| 295 | len, fl6->flowi6_proto, |
| 296 | skb->csum); |
| 297 | } else { |
| 298 | __wsum tmp_csum = 0; |
| 299 | |
| 300 | skb_queue_walk(&sk->sk_write_queue, skb) { |
| 301 | tmp_csum = csum_add(tmp_csum, skb->csum); |
| 302 | } |
| 303 | |
| 304 | tmp_csum = csum_partial(icmp6h, |
| 305 | sizeof(struct icmp6hdr), tmp_csum); |
| 306 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
| 307 | &fl6->daddr, |
| 308 | len, fl6->flowi6_proto, |
| 309 | tmp_csum); |
| 310 | } |
| 311 | ip6_push_pending_frames(sk); |
| 312 | } |
| 313 | |
| 314 | struct icmpv6_msg { |
| 315 | struct sk_buff *skb; |
| 316 | int offset; |
| 317 | uint8_t type; |
| 318 | }; |
| 319 | |
| 320 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) |
| 321 | { |
| 322 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; |
| 323 | struct sk_buff *org_skb = msg->skb; |
| 324 | __wsum csum; |
| 325 | |
| 326 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, |
| 327 | to, len); |
| 328 | skb->csum = csum_block_add(skb->csum, csum, odd); |
| 329 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
| 330 | nf_ct_attach(skb, org_skb); |
| 331 | return 0; |
| 332 | } |
| 333 | |
| 334 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
| 335 | static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) |
| 336 | { |
| 337 | struct ipv6hdr *iph = ipv6_hdr(skb); |
| 338 | struct ipv6_destopt_hao *hao; |
| 339 | int off; |
| 340 | |
| 341 | if (opt->dsthao) { |
| 342 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); |
| 343 | if (likely(off >= 0)) { |
| 344 | hao = (struct ipv6_destopt_hao *) |
| 345 | (skb_network_header(skb) + off); |
| 346 | swap(iph->saddr, hao->addr); |
| 347 | } |
| 348 | } |
| 349 | } |
| 350 | #else |
| 351 | static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {} |
| 352 | #endif |
| 353 | |
| 354 | static struct dst_entry *icmpv6_route_lookup(struct net *net, |
| 355 | struct sk_buff *skb, |
| 356 | struct sock *sk, |
| 357 | struct flowi6 *fl6) |
| 358 | { |
| 359 | struct dst_entry *dst, *dst2; |
| 360 | struct flowi6 fl2; |
| 361 | int err; |
| 362 | |
| 363 | err = ip6_dst_lookup(net, sk, &dst, fl6); |
| 364 | if (err) |
| 365 | return ERR_PTR(err); |
| 366 | |
| 367 | /* |
| 368 | * We won't send icmp if the destination is known |
| 369 | * anycast unless we need to treat anycast as unicast. |
| 370 | */ |
| 371 | if (!READ_ONCE(net->ipv6.sysctl.icmpv6_error_anycast_as_unicast) && |
| 372 | ipv6_anycast_destination(dst, &fl6->daddr)) { |
| 373 | net_dbg_ratelimited("icmp6_send: acast source\n"); |
| 374 | dst_release(dst); |
| 375 | return ERR_PTR(-EINVAL); |
| 376 | } |
| 377 | |
| 378 | /* No need to clone since we're just using its address. */ |
| 379 | dst2 = dst; |
| 380 | |
| 381 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); |
| 382 | if (!IS_ERR(dst)) { |
| 383 | if (dst != dst2) |
| 384 | return dst; |
| 385 | } else { |
| 386 | if (PTR_ERR(dst) == -EPERM) |
| 387 | dst = NULL; |
| 388 | else |
| 389 | return dst; |
| 390 | } |
| 391 | |
| 392 | err = xfrm_decode_session_reverse(net, skb, flowi6_to_flowi(&fl2), AF_INET6); |
| 393 | if (err) |
| 394 | goto relookup_failed; |
| 395 | |
| 396 | err = ip6_dst_lookup(net, sk, &dst2, &fl2); |
| 397 | if (err) |
| 398 | goto relookup_failed; |
| 399 | |
| 400 | dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); |
| 401 | if (!IS_ERR(dst2)) { |
| 402 | dst_release(dst); |
| 403 | dst = dst2; |
| 404 | } else { |
| 405 | err = PTR_ERR(dst2); |
| 406 | if (err == -EPERM) { |
| 407 | dst_release(dst); |
| 408 | return dst2; |
| 409 | } else |
| 410 | goto relookup_failed; |
| 411 | } |
| 412 | |
| 413 | relookup_failed: |
| 414 | if (dst) |
| 415 | return dst; |
| 416 | return ERR_PTR(err); |
| 417 | } |
| 418 | |
| 419 | static struct net_device *icmp6_dev(const struct sk_buff *skb) |
| 420 | { |
| 421 | struct net_device *dev = skb->dev; |
| 422 | |
| 423 | /* for local traffic to local address, skb dev is the loopback |
| 424 | * device. Check if there is a dst attached to the skb and if so |
| 425 | * get the real device index. Same is needed for replies to a link |
| 426 | * local address on a device enslaved to an L3 master device |
| 427 | */ |
| 428 | if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) { |
| 429 | const struct rt6_info *rt6 = skb_rt6_info(skb); |
| 430 | |
| 431 | /* The destination could be an external IP in Ext Hdr (SRv6, RPL, etc.), |
| 432 | * and ip6_null_entry could be set to skb if no route is found. |
| 433 | */ |
| 434 | if (rt6 && rt6->rt6i_idev) |
| 435 | dev = rt6->rt6i_idev->dev; |
| 436 | } |
| 437 | |
| 438 | return dev; |
| 439 | } |
| 440 | |
| 441 | static int icmp6_iif(const struct sk_buff *skb) |
| 442 | { |
| 443 | return icmp6_dev(skb)->ifindex; |
| 444 | } |
| 445 | |
| 446 | /* |
| 447 | * Send an ICMP message in response to a packet in error |
| 448 | */ |
| 449 | void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, |
| 450 | const struct in6_addr *force_saddr, |
| 451 | const struct inet6_skb_parm *parm) |
| 452 | { |
| 453 | struct inet6_dev *idev = NULL; |
| 454 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
| 455 | struct sock *sk; |
| 456 | struct net *net; |
| 457 | struct ipv6_pinfo *np; |
| 458 | const struct in6_addr *saddr = NULL; |
| 459 | bool apply_ratelimit = false; |
| 460 | struct dst_entry *dst; |
| 461 | struct icmp6hdr tmp_hdr; |
| 462 | struct flowi6 fl6; |
| 463 | struct icmpv6_msg msg; |
| 464 | struct ipcm6_cookie ipc6; |
| 465 | int iif = 0; |
| 466 | int addr_type = 0; |
| 467 | int len; |
| 468 | u32 mark; |
| 469 | |
| 470 | if ((u8 *)hdr < skb->head || |
| 471 | (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb)) |
| 472 | return; |
| 473 | |
| 474 | if (!skb->dev) |
| 475 | return; |
| 476 | |
| 477 | rcu_read_lock(); |
| 478 | |
| 479 | net = dev_net_rcu(skb->dev); |
| 480 | mark = IP6_REPLY_MARK(net, skb->mark); |
| 481 | /* |
| 482 | * Make sure we respect the rules |
| 483 | * i.e. RFC 1885 2.4(e) |
| 484 | * Rule (e.1) is enforced by not using icmp6_send |
| 485 | * in any code that processes icmp errors. |
| 486 | */ |
| 487 | addr_type = ipv6_addr_type(&hdr->daddr); |
| 488 | |
| 489 | if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) || |
| 490 | ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr)) |
| 491 | saddr = &hdr->daddr; |
| 492 | |
| 493 | /* |
| 494 | * Dest addr check |
| 495 | */ |
| 496 | |
| 497 | if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) { |
| 498 | if (type != ICMPV6_PKT_TOOBIG && |
| 499 | !(type == ICMPV6_PARAMPROB && |
| 500 | code == ICMPV6_UNK_OPTION && |
| 501 | (opt_unrec(skb, info)))) |
| 502 | goto out; |
| 503 | |
| 504 | saddr = NULL; |
| 505 | } |
| 506 | |
| 507 | addr_type = ipv6_addr_type(&hdr->saddr); |
| 508 | |
| 509 | /* |
| 510 | * Source addr check |
| 511 | */ |
| 512 | |
| 513 | if (__ipv6_addr_needs_scope_id(addr_type)) { |
| 514 | iif = icmp6_iif(skb); |
| 515 | } else { |
| 516 | /* |
| 517 | * The source device is used for looking up which routing table |
| 518 | * to use for sending an ICMP error. |
| 519 | */ |
| 520 | iif = l3mdev_master_ifindex(skb->dev); |
| 521 | } |
| 522 | |
| 523 | /* |
| 524 | * Must not send error if the source does not uniquely |
| 525 | * identify a single node (RFC2463 Section 2.4). |
| 526 | * We check unspecified / multicast addresses here, |
| 527 | * and anycast addresses will be checked later. |
| 528 | */ |
| 529 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { |
| 530 | net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n", |
| 531 | &hdr->saddr, &hdr->daddr); |
| 532 | goto out; |
| 533 | } |
| 534 | |
| 535 | /* |
| 536 | * Never answer to a ICMP packet. |
| 537 | */ |
| 538 | if (is_ineligible(skb)) { |
| 539 | net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n", |
| 540 | &hdr->saddr, &hdr->daddr); |
| 541 | goto out; |
| 542 | } |
| 543 | |
| 544 | /* Needed by both icmpv6_global_allow and icmpv6_xmit_lock */ |
| 545 | local_bh_disable(); |
| 546 | |
| 547 | /* Check global sysctl_icmp_msgs_per_sec ratelimit */ |
| 548 | if (!(skb->dev->flags & IFF_LOOPBACK) && |
| 549 | !icmpv6_global_allow(net, type, &apply_ratelimit)) |
| 550 | goto out_bh_enable; |
| 551 | |
| 552 | mip6_addr_swap(skb, parm); |
| 553 | |
| 554 | sk = icmpv6_xmit_lock(net); |
| 555 | if (!sk) |
| 556 | goto out_bh_enable; |
| 557 | |
| 558 | memset(&fl6, 0, sizeof(fl6)); |
| 559 | fl6.flowi6_proto = IPPROTO_ICMPV6; |
| 560 | fl6.daddr = hdr->saddr; |
| 561 | if (force_saddr) |
| 562 | saddr = force_saddr; |
| 563 | if (saddr) { |
| 564 | fl6.saddr = *saddr; |
| 565 | } else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) { |
| 566 | /* select a more meaningful saddr from input if */ |
| 567 | struct net_device *in_netdev; |
| 568 | |
| 569 | in_netdev = dev_get_by_index(net, parm->iif); |
| 570 | if (in_netdev) { |
| 571 | ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr, |
| 572 | inet6_sk(sk)->srcprefs, |
| 573 | &fl6.saddr); |
| 574 | dev_put(in_netdev); |
| 575 | } |
| 576 | } |
| 577 | fl6.flowi6_mark = mark; |
| 578 | fl6.flowi6_oif = iif; |
| 579 | fl6.fl6_icmp_type = type; |
| 580 | fl6.fl6_icmp_code = code; |
| 581 | fl6.flowi6_uid = sock_net_uid(net, NULL); |
| 582 | fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL); |
| 583 | security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6)); |
| 584 | |
| 585 | np = inet6_sk(sk); |
| 586 | |
| 587 | if (!icmpv6_xrlim_allow(sk, type, &fl6, apply_ratelimit)) |
| 588 | goto out_unlock; |
| 589 | |
| 590 | tmp_hdr.icmp6_type = type; |
| 591 | tmp_hdr.icmp6_code = code; |
| 592 | tmp_hdr.icmp6_cksum = 0; |
| 593 | tmp_hdr.icmp6_pointer = htonl(info); |
| 594 | |
| 595 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
| 596 | fl6.flowi6_oif = READ_ONCE(np->mcast_oif); |
| 597 | else if (!fl6.flowi6_oif) |
| 598 | fl6.flowi6_oif = READ_ONCE(np->ucast_oif); |
| 599 | |
| 600 | ipcm6_init_sk(&ipc6, sk); |
| 601 | ipc6.sockc.mark = mark; |
| 602 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); |
| 603 | |
| 604 | dst = icmpv6_route_lookup(net, skb, sk, &fl6); |
| 605 | if (IS_ERR(dst)) |
| 606 | goto out_unlock; |
| 607 | |
| 608 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); |
| 609 | |
| 610 | msg.skb = skb; |
| 611 | msg.offset = skb_network_offset(skb); |
| 612 | msg.type = type; |
| 613 | |
| 614 | len = skb->len - msg.offset; |
| 615 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr)); |
| 616 | if (len < 0) { |
| 617 | net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n", |
| 618 | &hdr->saddr, &hdr->daddr); |
| 619 | goto out_dst_release; |
| 620 | } |
| 621 | |
| 622 | idev = __in6_dev_get(skb->dev); |
| 623 | |
| 624 | if (ip6_append_data(sk, icmpv6_getfrag, &msg, |
| 625 | len + sizeof(struct icmp6hdr), |
| 626 | sizeof(struct icmp6hdr), |
| 627 | &ipc6, &fl6, dst_rt6_info(dst), |
| 628 | MSG_DONTWAIT)) { |
| 629 | ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); |
| 630 | ip6_flush_pending_frames(sk); |
| 631 | } else { |
| 632 | icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, |
| 633 | len + sizeof(struct icmp6hdr)); |
| 634 | } |
| 635 | |
| 636 | out_dst_release: |
| 637 | dst_release(dst); |
| 638 | out_unlock: |
| 639 | icmpv6_xmit_unlock(sk); |
| 640 | out_bh_enable: |
| 641 | local_bh_enable(); |
| 642 | out: |
| 643 | rcu_read_unlock(); |
| 644 | } |
| 645 | EXPORT_SYMBOL(icmp6_send); |
| 646 | |
| 647 | /* Slightly more convenient version of icmp6_send with drop reasons. |
| 648 | */ |
| 649 | void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos, |
| 650 | enum skb_drop_reason reason) |
| 651 | { |
| 652 | icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb)); |
| 653 | kfree_skb_reason(skb, reason); |
| 654 | } |
| 655 | |
| 656 | /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH |
| 657 | * if sufficient data bytes are available |
| 658 | * @nhs is the size of the tunnel header(s) : |
| 659 | * Either an IPv4 header for SIT encap |
| 660 | * an IPv4 header + GRE header for GRE encap |
| 661 | */ |
| 662 | int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type, |
| 663 | unsigned int data_len) |
| 664 | { |
| 665 | struct in6_addr temp_saddr; |
| 666 | struct rt6_info *rt; |
| 667 | struct sk_buff *skb2; |
| 668 | u32 info = 0; |
| 669 | |
| 670 | if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8)) |
| 671 | return 1; |
| 672 | |
| 673 | /* RFC 4884 (partial) support for ICMP extensions */ |
| 674 | if (data_len < 128 || (data_len & 7) || skb->len < data_len) |
| 675 | data_len = 0; |
| 676 | |
| 677 | skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC); |
| 678 | |
| 679 | if (!skb2) |
| 680 | return 1; |
| 681 | |
| 682 | skb_dst_drop(skb2); |
| 683 | skb_pull(skb2, nhs); |
| 684 | skb_reset_network_header(skb2); |
| 685 | |
| 686 | rt = rt6_lookup(dev_net_rcu(skb->dev), &ipv6_hdr(skb2)->saddr, |
| 687 | NULL, 0, skb, 0); |
| 688 | |
| 689 | if (rt && rt->dst.dev) |
| 690 | skb2->dev = rt->dst.dev; |
| 691 | |
| 692 | ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr); |
| 693 | |
| 694 | if (data_len) { |
| 695 | /* RFC 4884 (partial) support : |
| 696 | * insert 0 padding at the end, before the extensions |
| 697 | */ |
| 698 | __skb_push(skb2, nhs); |
| 699 | skb_reset_network_header(skb2); |
| 700 | memmove(skb2->data, skb2->data + nhs, data_len - nhs); |
| 701 | memset(skb2->data + data_len - nhs, 0, nhs); |
| 702 | /* RFC 4884 4.5 : Length is measured in 64-bit words, |
| 703 | * and stored in reserved[0] |
| 704 | */ |
| 705 | info = (data_len/8) << 24; |
| 706 | } |
| 707 | if (type == ICMP_TIME_EXCEEDED) |
| 708 | icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, |
| 709 | info, &temp_saddr, IP6CB(skb2)); |
| 710 | else |
| 711 | icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, |
| 712 | info, &temp_saddr, IP6CB(skb2)); |
| 713 | if (rt) |
| 714 | ip6_rt_put(rt); |
| 715 | |
| 716 | kfree_skb(skb2); |
| 717 | |
| 718 | return 0; |
| 719 | } |
| 720 | EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach); |
| 721 | |
| 722 | static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) |
| 723 | { |
| 724 | struct net *net = dev_net_rcu(skb->dev); |
| 725 | struct sock *sk; |
| 726 | struct inet6_dev *idev; |
| 727 | struct ipv6_pinfo *np; |
| 728 | const struct in6_addr *saddr = NULL; |
| 729 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
| 730 | bool apply_ratelimit = false; |
| 731 | struct icmp6hdr tmp_hdr; |
| 732 | struct flowi6 fl6; |
| 733 | struct icmpv6_msg msg; |
| 734 | struct dst_entry *dst; |
| 735 | struct ipcm6_cookie ipc6; |
| 736 | u32 mark = IP6_REPLY_MARK(net, skb->mark); |
| 737 | SKB_DR(reason); |
| 738 | bool acast; |
| 739 | u8 type; |
| 740 | |
| 741 | if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) && |
| 742 | net->ipv6.sysctl.icmpv6_echo_ignore_multicast) |
| 743 | return reason; |
| 744 | |
| 745 | saddr = &ipv6_hdr(skb)->daddr; |
| 746 | |
| 747 | acast = ipv6_anycast_destination(skb_dst(skb), saddr); |
| 748 | if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast) |
| 749 | return reason; |
| 750 | |
| 751 | if (!ipv6_unicast_destination(skb) && |
| 752 | !(net->ipv6.sysctl.anycast_src_echo_reply && acast)) |
| 753 | saddr = NULL; |
| 754 | |
| 755 | if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST) |
| 756 | type = ICMPV6_EXT_ECHO_REPLY; |
| 757 | else |
| 758 | type = ICMPV6_ECHO_REPLY; |
| 759 | |
| 760 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); |
| 761 | tmp_hdr.icmp6_type = type; |
| 762 | |
| 763 | memset(&fl6, 0, sizeof(fl6)); |
| 764 | if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES) |
| 765 | fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb)); |
| 766 | |
| 767 | fl6.flowi6_proto = IPPROTO_ICMPV6; |
| 768 | fl6.daddr = ipv6_hdr(skb)->saddr; |
| 769 | if (saddr) |
| 770 | fl6.saddr = *saddr; |
| 771 | fl6.flowi6_oif = icmp6_iif(skb); |
| 772 | fl6.fl6_icmp_type = type; |
| 773 | fl6.flowi6_mark = mark; |
| 774 | fl6.flowi6_uid = sock_net_uid(net, NULL); |
| 775 | security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6)); |
| 776 | |
| 777 | local_bh_disable(); |
| 778 | sk = icmpv6_xmit_lock(net); |
| 779 | if (!sk) |
| 780 | goto out_bh_enable; |
| 781 | np = inet6_sk(sk); |
| 782 | |
| 783 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
| 784 | fl6.flowi6_oif = READ_ONCE(np->mcast_oif); |
| 785 | else if (!fl6.flowi6_oif) |
| 786 | fl6.flowi6_oif = READ_ONCE(np->ucast_oif); |
| 787 | |
| 788 | if (ip6_dst_lookup(net, sk, &dst, &fl6)) |
| 789 | goto out; |
| 790 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); |
| 791 | if (IS_ERR(dst)) |
| 792 | goto out; |
| 793 | |
| 794 | /* Check the ratelimit */ |
| 795 | if ((!(skb->dev->flags & IFF_LOOPBACK) && |
| 796 | !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY, &apply_ratelimit)) || |
| 797 | !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6, apply_ratelimit)) |
| 798 | goto out_dst_release; |
| 799 | |
| 800 | idev = __in6_dev_get(skb->dev); |
| 801 | |
| 802 | msg.skb = skb; |
| 803 | msg.offset = 0; |
| 804 | msg.type = type; |
| 805 | |
| 806 | ipcm6_init_sk(&ipc6, sk); |
| 807 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); |
| 808 | ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb)); |
| 809 | ipc6.sockc.mark = mark; |
| 810 | |
| 811 | if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST) |
| 812 | if (!icmp_build_probe(skb, (struct icmphdr *)&tmp_hdr)) |
| 813 | goto out_dst_release; |
| 814 | |
| 815 | if (ip6_append_data(sk, icmpv6_getfrag, &msg, |
| 816 | skb->len + sizeof(struct icmp6hdr), |
| 817 | sizeof(struct icmp6hdr), &ipc6, &fl6, |
| 818 | dst_rt6_info(dst), MSG_DONTWAIT)) { |
| 819 | __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); |
| 820 | ip6_flush_pending_frames(sk); |
| 821 | } else { |
| 822 | icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, |
| 823 | skb->len + sizeof(struct icmp6hdr)); |
| 824 | reason = SKB_CONSUMED; |
| 825 | } |
| 826 | out_dst_release: |
| 827 | dst_release(dst); |
| 828 | out: |
| 829 | icmpv6_xmit_unlock(sk); |
| 830 | out_bh_enable: |
| 831 | local_bh_enable(); |
| 832 | return reason; |
| 833 | } |
| 834 | |
| 835 | enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type, |
| 836 | u8 code, __be32 info) |
| 837 | { |
| 838 | struct inet6_skb_parm *opt = IP6CB(skb); |
| 839 | struct net *net = dev_net_rcu(skb->dev); |
| 840 | const struct inet6_protocol *ipprot; |
| 841 | enum skb_drop_reason reason; |
| 842 | int inner_offset; |
| 843 | __be16 frag_off; |
| 844 | u8 nexthdr; |
| 845 | |
| 846 | reason = pskb_may_pull_reason(skb, sizeof(struct ipv6hdr)); |
| 847 | if (reason != SKB_NOT_DROPPED_YET) |
| 848 | goto out; |
| 849 | |
| 850 | seg6_icmp_srh(skb, opt); |
| 851 | |
| 852 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; |
| 853 | if (ipv6_ext_hdr(nexthdr)) { |
| 854 | /* now skip over extension headers */ |
| 855 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), |
| 856 | &nexthdr, &frag_off); |
| 857 | if (inner_offset < 0) { |
| 858 | SKB_DR_SET(reason, IPV6_BAD_EXTHDR); |
| 859 | goto out; |
| 860 | } |
| 861 | } else { |
| 862 | inner_offset = sizeof(struct ipv6hdr); |
| 863 | } |
| 864 | |
| 865 | /* Checkin header including 8 bytes of inner protocol header. */ |
| 866 | reason = pskb_may_pull_reason(skb, inner_offset + 8); |
| 867 | if (reason != SKB_NOT_DROPPED_YET) |
| 868 | goto out; |
| 869 | |
| 870 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
| 871 | Without this we will not able f.e. to make source routed |
| 872 | pmtu discovery. |
| 873 | Corresponding argument (opt) to notifiers is already added. |
| 874 | --ANK (980726) |
| 875 | */ |
| 876 | |
| 877 | ipprot = rcu_dereference(inet6_protos[nexthdr]); |
| 878 | if (ipprot && ipprot->err_handler) |
| 879 | ipprot->err_handler(skb, opt, type, code, inner_offset, info); |
| 880 | |
| 881 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
| 882 | return SKB_CONSUMED; |
| 883 | |
| 884 | out: |
| 885 | __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); |
| 886 | return reason; |
| 887 | } |
| 888 | |
| 889 | /* |
| 890 | * Handle icmp messages |
| 891 | */ |
| 892 | |
| 893 | static int icmpv6_rcv(struct sk_buff *skb) |
| 894 | { |
| 895 | enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; |
| 896 | struct net *net = dev_net_rcu(skb->dev); |
| 897 | struct net_device *dev = icmp6_dev(skb); |
| 898 | struct inet6_dev *idev = __in6_dev_get(dev); |
| 899 | const struct in6_addr *saddr, *daddr; |
| 900 | struct icmp6hdr *hdr; |
| 901 | u8 type; |
| 902 | |
| 903 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| 904 | struct sec_path *sp = skb_sec_path(skb); |
| 905 | int nh; |
| 906 | |
| 907 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
| 908 | XFRM_STATE_ICMP)) { |
| 909 | reason = SKB_DROP_REASON_XFRM_POLICY; |
| 910 | goto drop_no_count; |
| 911 | } |
| 912 | |
| 913 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr))) |
| 914 | goto drop_no_count; |
| 915 | |
| 916 | nh = skb_network_offset(skb); |
| 917 | skb_set_network_header(skb, sizeof(*hdr)); |
| 918 | |
| 919 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, |
| 920 | skb)) { |
| 921 | reason = SKB_DROP_REASON_XFRM_POLICY; |
| 922 | goto drop_no_count; |
| 923 | } |
| 924 | |
| 925 | skb_set_network_header(skb, nh); |
| 926 | } |
| 927 | |
| 928 | __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_INMSGS); |
| 929 | |
| 930 | saddr = &ipv6_hdr(skb)->saddr; |
| 931 | daddr = &ipv6_hdr(skb)->daddr; |
| 932 | |
| 933 | if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) { |
| 934 | net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n", |
| 935 | saddr, daddr); |
| 936 | goto csum_error; |
| 937 | } |
| 938 | |
| 939 | if (!pskb_pull(skb, sizeof(*hdr))) |
| 940 | goto discard_it; |
| 941 | |
| 942 | hdr = icmp6_hdr(skb); |
| 943 | |
| 944 | type = hdr->icmp6_type; |
| 945 | |
| 946 | ICMP6MSGIN_INC_STATS(dev_net_rcu(dev), idev, type); |
| 947 | |
| 948 | switch (type) { |
| 949 | case ICMPV6_ECHO_REQUEST: |
| 950 | if (!net->ipv6.sysctl.icmpv6_echo_ignore_all) |
| 951 | reason = icmpv6_echo_reply(skb); |
| 952 | break; |
| 953 | case ICMPV6_EXT_ECHO_REQUEST: |
| 954 | if (!net->ipv6.sysctl.icmpv6_echo_ignore_all && |
| 955 | READ_ONCE(net->ipv4.sysctl_icmp_echo_enable_probe)) |
| 956 | reason = icmpv6_echo_reply(skb); |
| 957 | break; |
| 958 | |
| 959 | case ICMPV6_ECHO_REPLY: |
| 960 | case ICMPV6_EXT_ECHO_REPLY: |
| 961 | ping_rcv(skb); |
| 962 | return 0; |
| 963 | |
| 964 | case ICMPV6_PKT_TOOBIG: |
| 965 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update |
| 966 | standard destination cache. Seems, only "advanced" |
| 967 | destination cache will allow to solve this problem |
| 968 | --ANK (980726) |
| 969 | */ |
| 970 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| 971 | goto discard_it; |
| 972 | hdr = icmp6_hdr(skb); |
| 973 | |
| 974 | /* to notify */ |
| 975 | fallthrough; |
| 976 | case ICMPV6_DEST_UNREACH: |
| 977 | case ICMPV6_TIME_EXCEED: |
| 978 | case ICMPV6_PARAMPROB: |
| 979 | reason = icmpv6_notify(skb, type, hdr->icmp6_code, |
| 980 | hdr->icmp6_mtu); |
| 981 | break; |
| 982 | |
| 983 | case NDISC_ROUTER_SOLICITATION: |
| 984 | case NDISC_ROUTER_ADVERTISEMENT: |
| 985 | case NDISC_NEIGHBOUR_SOLICITATION: |
| 986 | case NDISC_NEIGHBOUR_ADVERTISEMENT: |
| 987 | case NDISC_REDIRECT: |
| 988 | reason = ndisc_rcv(skb); |
| 989 | break; |
| 990 | |
| 991 | case ICMPV6_MGM_QUERY: |
| 992 | igmp6_event_query(skb); |
| 993 | return 0; |
| 994 | |
| 995 | case ICMPV6_MGM_REPORT: |
| 996 | igmp6_event_report(skb); |
| 997 | return 0; |
| 998 | |
| 999 | case ICMPV6_MGM_REDUCTION: |
| 1000 | case ICMPV6_NI_QUERY: |
| 1001 | case ICMPV6_NI_REPLY: |
| 1002 | case ICMPV6_MLD2_REPORT: |
| 1003 | case ICMPV6_DHAAD_REQUEST: |
| 1004 | case ICMPV6_DHAAD_REPLY: |
| 1005 | case ICMPV6_MOBILE_PREFIX_SOL: |
| 1006 | case ICMPV6_MOBILE_PREFIX_ADV: |
| 1007 | break; |
| 1008 | |
| 1009 | default: |
| 1010 | /* informational */ |
| 1011 | if (type & ICMPV6_INFOMSG_MASK) |
| 1012 | break; |
| 1013 | |
| 1014 | net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n", |
| 1015 | saddr, daddr); |
| 1016 | |
| 1017 | /* |
| 1018 | * error of unknown type. |
| 1019 | * must pass to upper level |
| 1020 | */ |
| 1021 | |
| 1022 | reason = icmpv6_notify(skb, type, hdr->icmp6_code, |
| 1023 | hdr->icmp6_mtu); |
| 1024 | } |
| 1025 | |
| 1026 | /* until the v6 path can be better sorted assume failure and |
| 1027 | * preserve the status quo behaviour for the rest of the paths to here |
| 1028 | */ |
| 1029 | if (reason) |
| 1030 | kfree_skb_reason(skb, reason); |
| 1031 | else |
| 1032 | consume_skb(skb); |
| 1033 | |
| 1034 | return 0; |
| 1035 | |
| 1036 | csum_error: |
| 1037 | reason = SKB_DROP_REASON_ICMP_CSUM; |
| 1038 | __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_CSUMERRORS); |
| 1039 | discard_it: |
| 1040 | __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_INERRORS); |
| 1041 | drop_no_count: |
| 1042 | kfree_skb_reason(skb, reason); |
| 1043 | return 0; |
| 1044 | } |
| 1045 | |
| 1046 | void icmpv6_flow_init(const struct sock *sk, struct flowi6 *fl6, u8 type, |
| 1047 | const struct in6_addr *saddr, |
| 1048 | const struct in6_addr *daddr, int oif) |
| 1049 | { |
| 1050 | memset(fl6, 0, sizeof(*fl6)); |
| 1051 | fl6->saddr = *saddr; |
| 1052 | fl6->daddr = *daddr; |
| 1053 | fl6->flowi6_proto = IPPROTO_ICMPV6; |
| 1054 | fl6->fl6_icmp_type = type; |
| 1055 | fl6->fl6_icmp_code = 0; |
| 1056 | fl6->flowi6_oif = oif; |
| 1057 | security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6)); |
| 1058 | } |
| 1059 | |
| 1060 | int __init icmpv6_init(void) |
| 1061 | { |
| 1062 | struct sock *sk; |
| 1063 | int err, i; |
| 1064 | |
| 1065 | for_each_possible_cpu(i) { |
| 1066 | err = inet_ctl_sock_create(&sk, PF_INET6, |
| 1067 | SOCK_RAW, IPPROTO_ICMPV6, &init_net); |
| 1068 | if (err < 0) { |
| 1069 | pr_err("Failed to initialize the ICMP6 control socket (err %d)\n", |
| 1070 | err); |
| 1071 | return err; |
| 1072 | } |
| 1073 | |
| 1074 | per_cpu(ipv6_icmp_sk, i) = sk; |
| 1075 | |
| 1076 | /* Enough space for 2 64K ICMP packets, including |
| 1077 | * sk_buff struct overhead. |
| 1078 | */ |
| 1079 | sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); |
| 1080 | } |
| 1081 | |
| 1082 | err = -EAGAIN; |
| 1083 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) |
| 1084 | goto fail; |
| 1085 | |
| 1086 | err = inet6_register_icmp_sender(icmp6_send); |
| 1087 | if (err) |
| 1088 | goto sender_reg_err; |
| 1089 | return 0; |
| 1090 | |
| 1091 | sender_reg_err: |
| 1092 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
| 1093 | fail: |
| 1094 | pr_err("Failed to register ICMP6 protocol\n"); |
| 1095 | return err; |
| 1096 | } |
| 1097 | |
| 1098 | void icmpv6_cleanup(void) |
| 1099 | { |
| 1100 | inet6_unregister_icmp_sender(icmp6_send); |
| 1101 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
| 1102 | } |
| 1103 | |
| 1104 | |
| 1105 | static const struct icmp6_err { |
| 1106 | int err; |
| 1107 | int fatal; |
| 1108 | } tab_unreach[] = { |
| 1109 | { /* NOROUTE */ |
| 1110 | .err = ENETUNREACH, |
| 1111 | .fatal = 0, |
| 1112 | }, |
| 1113 | { /* ADM_PROHIBITED */ |
| 1114 | .err = EACCES, |
| 1115 | .fatal = 1, |
| 1116 | }, |
| 1117 | { /* Was NOT_NEIGHBOUR, now reserved */ |
| 1118 | .err = EHOSTUNREACH, |
| 1119 | .fatal = 0, |
| 1120 | }, |
| 1121 | { /* ADDR_UNREACH */ |
| 1122 | .err = EHOSTUNREACH, |
| 1123 | .fatal = 0, |
| 1124 | }, |
| 1125 | { /* PORT_UNREACH */ |
| 1126 | .err = ECONNREFUSED, |
| 1127 | .fatal = 1, |
| 1128 | }, |
| 1129 | { /* POLICY_FAIL */ |
| 1130 | .err = EACCES, |
| 1131 | .fatal = 1, |
| 1132 | }, |
| 1133 | { /* REJECT_ROUTE */ |
| 1134 | .err = EACCES, |
| 1135 | .fatal = 1, |
| 1136 | }, |
| 1137 | }; |
| 1138 | |
| 1139 | int icmpv6_err_convert(u8 type, u8 code, int *err) |
| 1140 | { |
| 1141 | int fatal = 0; |
| 1142 | |
| 1143 | *err = EPROTO; |
| 1144 | |
| 1145 | switch (type) { |
| 1146 | case ICMPV6_DEST_UNREACH: |
| 1147 | fatal = 1; |
| 1148 | if (code < ARRAY_SIZE(tab_unreach)) { |
| 1149 | *err = tab_unreach[code].err; |
| 1150 | fatal = tab_unreach[code].fatal; |
| 1151 | } |
| 1152 | break; |
| 1153 | |
| 1154 | case ICMPV6_PKT_TOOBIG: |
| 1155 | *err = EMSGSIZE; |
| 1156 | break; |
| 1157 | |
| 1158 | case ICMPV6_PARAMPROB: |
| 1159 | *err = EPROTO; |
| 1160 | fatal = 1; |
| 1161 | break; |
| 1162 | |
| 1163 | case ICMPV6_TIME_EXCEED: |
| 1164 | *err = EHOSTUNREACH; |
| 1165 | break; |
| 1166 | } |
| 1167 | |
| 1168 | return fatal; |
| 1169 | } |
| 1170 | EXPORT_SYMBOL(icmpv6_err_convert); |
| 1171 | |
| 1172 | #ifdef CONFIG_SYSCTL |
| 1173 | static struct ctl_table ipv6_icmp_table_template[] = { |
| 1174 | { |
| 1175 | .procname = "ratelimit", |
| 1176 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
| 1177 | .maxlen = sizeof(int), |
| 1178 | .mode = 0644, |
| 1179 | .proc_handler = proc_dointvec_ms_jiffies, |
| 1180 | }, |
| 1181 | { |
| 1182 | .procname = "echo_ignore_all", |
| 1183 | .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all, |
| 1184 | .maxlen = sizeof(u8), |
| 1185 | .mode = 0644, |
| 1186 | .proc_handler = proc_dou8vec_minmax, |
| 1187 | }, |
| 1188 | { |
| 1189 | .procname = "echo_ignore_multicast", |
| 1190 | .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast, |
| 1191 | .maxlen = sizeof(u8), |
| 1192 | .mode = 0644, |
| 1193 | .proc_handler = proc_dou8vec_minmax, |
| 1194 | }, |
| 1195 | { |
| 1196 | .procname = "echo_ignore_anycast", |
| 1197 | .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast, |
| 1198 | .maxlen = sizeof(u8), |
| 1199 | .mode = 0644, |
| 1200 | .proc_handler = proc_dou8vec_minmax, |
| 1201 | }, |
| 1202 | { |
| 1203 | .procname = "ratemask", |
| 1204 | .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr, |
| 1205 | .maxlen = ICMPV6_MSG_MAX + 1, |
| 1206 | .mode = 0644, |
| 1207 | .proc_handler = proc_do_large_bitmap, |
| 1208 | }, |
| 1209 | { |
| 1210 | .procname = "error_anycast_as_unicast", |
| 1211 | .data = &init_net.ipv6.sysctl.icmpv6_error_anycast_as_unicast, |
| 1212 | .maxlen = sizeof(u8), |
| 1213 | .mode = 0644, |
| 1214 | .proc_handler = proc_dou8vec_minmax, |
| 1215 | .extra1 = SYSCTL_ZERO, |
| 1216 | .extra2 = SYSCTL_ONE, |
| 1217 | }, |
| 1218 | }; |
| 1219 | |
| 1220 | struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) |
| 1221 | { |
| 1222 | struct ctl_table *table; |
| 1223 | |
| 1224 | table = kmemdup(ipv6_icmp_table_template, |
| 1225 | sizeof(ipv6_icmp_table_template), |
| 1226 | GFP_KERNEL); |
| 1227 | |
| 1228 | if (table) { |
| 1229 | table[0].data = &net->ipv6.sysctl.icmpv6_time; |
| 1230 | table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all; |
| 1231 | table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast; |
| 1232 | table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast; |
| 1233 | table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr; |
| 1234 | table[5].data = &net->ipv6.sysctl.icmpv6_error_anycast_as_unicast; |
| 1235 | } |
| 1236 | return table; |
| 1237 | } |
| 1238 | |
| 1239 | size_t ipv6_icmp_sysctl_table_size(void) |
| 1240 | { |
| 1241 | return ARRAY_SIZE(ipv6_icmp_table_template); |
| 1242 | } |
| 1243 | #endif |