1 /* 2 * common UDP/RAW code 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * $Id: datagram.c,v 1.24 2002/02/01 22:01:04 davem Exp $ 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #include <linux/errno.h> 17 #include <linux/types.h> 18 #include <linux/kernel.h> 19 #include <linux/sched.h> 20 #include <linux/interrupt.h> 21 #include <linux/socket.h> 22 #include <linux/sockios.h> 23 #include <linux/in6.h> 24 #include <linux/ipv6.h> 25 #include <linux/route.h> 26 27 #include <net/ipv6.h> 28 #include <net/ndisc.h> 29 #include <net/addrconf.h> 30 #include <net/transp_v6.h> 31 #include <net/ip6_route.h> 32 33 #include <linux/errqueue.h> 34 #include <asm/uaccess.h> 35 36 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 37 { 38 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 39 struct inet_sock *inet = inet_sk(sk); 40 struct ipv6_pinfo *np = inet6_sk(sk); 41 struct in6_addr *daddr, *final_p = NULL, final; 42 struct dst_entry *dst; 43 struct flowi fl; 44 struct ip6_flowlabel *flowlabel = NULL; 45 int addr_type; 46 int err; 47 48 if (usin->sin6_family == AF_INET) { 49 if (__ipv6_only_sock(sk)) 50 return -EAFNOSUPPORT; 51 err = ip4_datagram_connect(sk, uaddr, addr_len); 52 goto ipv4_connected; 53 } 54 55 if (addr_len < SIN6_LEN_RFC2133) 56 return -EINVAL; 57 58 if (usin->sin6_family != AF_INET6) 59 return -EAFNOSUPPORT; 60 61 memset(&fl, 0, sizeof(fl)); 62 if (np->sndflow) { 63 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK; 64 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) { 65 flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel); 66 if (flowlabel == NULL) 67 return -EINVAL; 68 ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst); 69 } 70 } 71 72 addr_type = ipv6_addr_type(&usin->sin6_addr); 73 74 if (addr_type == IPV6_ADDR_ANY) { 75 /* 76 * connect to self 77 */ 78 usin->sin6_addr.s6_addr[15] = 0x01; 79 } 80 81 daddr = &usin->sin6_addr; 82 83 if (addr_type == IPV6_ADDR_MAPPED) { 84 struct sockaddr_in sin; 85 86 if (__ipv6_only_sock(sk)) { 87 err = -ENETUNREACH; 88 goto out; 89 } 90 sin.sin_family = AF_INET; 91 sin.sin_addr.s_addr = daddr->s6_addr32[3]; 92 sin.sin_port = usin->sin6_port; 93 94 err = ip4_datagram_connect(sk, 95 (struct sockaddr*) &sin, 96 sizeof(sin)); 97 98 ipv4_connected: 99 if (err) 100 goto out; 101 102 ipv6_addr_set(&np->daddr, 0, 0, htonl(0x0000ffff), inet->daddr); 103 104 if (ipv6_addr_any(&np->saddr)) { 105 ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000ffff), 106 inet->saddr); 107 } 108 109 if (ipv6_addr_any(&np->rcv_saddr)) { 110 ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000ffff), 111 inet->rcv_saddr); 112 } 113 goto out; 114 } 115 116 if (addr_type&IPV6_ADDR_LINKLOCAL) { 117 if (addr_len >= sizeof(struct sockaddr_in6) && 118 usin->sin6_scope_id) { 119 if (sk->sk_bound_dev_if && 120 sk->sk_bound_dev_if != usin->sin6_scope_id) { 121 err = -EINVAL; 122 goto out; 123 } 124 sk->sk_bound_dev_if = usin->sin6_scope_id; 125 if (!sk->sk_bound_dev_if && 126 (addr_type & IPV6_ADDR_MULTICAST)) 127 fl.oif = np->mcast_oif; 128 } 129 130 /* Connect to link-local address requires an interface */ 131 if (!sk->sk_bound_dev_if) { 132 err = -EINVAL; 133 goto out; 134 } 135 } 136 137 ipv6_addr_copy(&np->daddr, daddr); 138 np->flow_label = fl.fl6_flowlabel; 139 140 inet->dport = usin->sin6_port; 141 142 /* 143 * Check for a route to destination an obtain the 144 * destination cache for it. 145 */ 146 147 fl.proto = sk->sk_protocol; 148 ipv6_addr_copy(&fl.fl6_dst, &np->daddr); 149 ipv6_addr_copy(&fl.fl6_src, &np->saddr); 150 fl.oif = sk->sk_bound_dev_if; 151 fl.fl_ip_dport = inet->dport; 152 fl.fl_ip_sport = inet->sport; 153 154 if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST)) 155 fl.oif = np->mcast_oif; 156 157 if (flowlabel) { 158 if (flowlabel->opt && flowlabel->opt->srcrt) { 159 struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt; 160 ipv6_addr_copy(&final, &fl.fl6_dst); 161 ipv6_addr_copy(&fl.fl6_dst, rt0->addr); 162 final_p = &final; 163 } 164 } else if (np->opt && np->opt->srcrt) { 165 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt; 166 ipv6_addr_copy(&final, &fl.fl6_dst); 167 ipv6_addr_copy(&fl.fl6_dst, rt0->addr); 168 final_p = &final; 169 } 170 171 err = ip6_dst_lookup(sk, &dst, &fl); 172 if (err) 173 goto out; 174 if (final_p) 175 ipv6_addr_copy(&fl.fl6_dst, final_p); 176 177 if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) { 178 dst_release(dst); 179 goto out; 180 } 181 182 /* source address lookup done in ip6_dst_lookup */ 183 184 if (ipv6_addr_any(&np->saddr)) 185 ipv6_addr_copy(&np->saddr, &fl.fl6_src); 186 187 if (ipv6_addr_any(&np->rcv_saddr)) { 188 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src); 189 inet->rcv_saddr = LOOPBACK4_IPV6; 190 } 191 192 ip6_dst_store(sk, dst, 193 ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ? 194 &np->daddr : NULL); 195 196 sk->sk_state = TCP_ESTABLISHED; 197 out: 198 fl6_sock_release(flowlabel); 199 return err; 200 } 201 202 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 203 u16 port, u32 info, u8 *payload) 204 { 205 struct ipv6_pinfo *np = inet6_sk(sk); 206 struct icmp6hdr *icmph = (struct icmp6hdr *)skb->h.raw; 207 struct sock_exterr_skb *serr; 208 209 if (!np->recverr) 210 return; 211 212 skb = skb_clone(skb, GFP_ATOMIC); 213 if (!skb) 214 return; 215 216 serr = SKB_EXT_ERR(skb); 217 serr->ee.ee_errno = err; 218 serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6; 219 serr->ee.ee_type = icmph->icmp6_type; 220 serr->ee.ee_code = icmph->icmp6_code; 221 serr->ee.ee_pad = 0; 222 serr->ee.ee_info = info; 223 serr->ee.ee_data = 0; 224 serr->addr_offset = (u8*)&(((struct ipv6hdr*)(icmph+1))->daddr) - skb->nh.raw; 225 serr->port = port; 226 227 skb->h.raw = payload; 228 __skb_pull(skb, payload - skb->data); 229 230 if (sock_queue_err_skb(sk, skb)) 231 kfree_skb(skb); 232 } 233 234 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info) 235 { 236 struct ipv6_pinfo *np = inet6_sk(sk); 237 struct sock_exterr_skb *serr; 238 struct ipv6hdr *iph; 239 struct sk_buff *skb; 240 241 if (!np->recverr) 242 return; 243 244 skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC); 245 if (!skb) 246 return; 247 248 iph = (struct ipv6hdr*)skb_put(skb, sizeof(struct ipv6hdr)); 249 skb->nh.ipv6h = iph; 250 ipv6_addr_copy(&iph->daddr, &fl->fl6_dst); 251 252 serr = SKB_EXT_ERR(skb); 253 serr->ee.ee_errno = err; 254 serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL; 255 serr->ee.ee_type = 0; 256 serr->ee.ee_code = 0; 257 serr->ee.ee_pad = 0; 258 serr->ee.ee_info = info; 259 serr->ee.ee_data = 0; 260 serr->addr_offset = (u8*)&iph->daddr - skb->nh.raw; 261 serr->port = fl->fl_ip_dport; 262 263 skb->h.raw = skb->tail; 264 __skb_pull(skb, skb->tail - skb->data); 265 266 if (sock_queue_err_skb(sk, skb)) 267 kfree_skb(skb); 268 } 269 270 /* 271 * Handle MSG_ERRQUEUE 272 */ 273 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len) 274 { 275 struct ipv6_pinfo *np = inet6_sk(sk); 276 struct sock_exterr_skb *serr; 277 struct sk_buff *skb, *skb2; 278 struct sockaddr_in6 *sin; 279 struct { 280 struct sock_extended_err ee; 281 struct sockaddr_in6 offender; 282 } errhdr; 283 int err; 284 int copied; 285 286 err = -EAGAIN; 287 skb = skb_dequeue(&sk->sk_error_queue); 288 if (skb == NULL) 289 goto out; 290 291 copied = skb->len; 292 if (copied > len) { 293 msg->msg_flags |= MSG_TRUNC; 294 copied = len; 295 } 296 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 297 if (err) 298 goto out_free_skb; 299 300 sock_recv_timestamp(msg, sk, skb); 301 302 serr = SKB_EXT_ERR(skb); 303 304 sin = (struct sockaddr_in6 *)msg->msg_name; 305 if (sin) { 306 sin->sin6_family = AF_INET6; 307 sin->sin6_flowinfo = 0; 308 sin->sin6_port = serr->port; 309 sin->sin6_scope_id = 0; 310 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) { 311 ipv6_addr_copy(&sin->sin6_addr, 312 (struct in6_addr *)(skb->nh.raw + serr->addr_offset)); 313 if (np->sndflow) 314 sin->sin6_flowinfo = *(u32*)(skb->nh.raw + serr->addr_offset - 24) & IPV6_FLOWINFO_MASK; 315 if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL) 316 sin->sin6_scope_id = IP6CB(skb)->iif; 317 } else { 318 ipv6_addr_set(&sin->sin6_addr, 0, 0, 319 htonl(0xffff), 320 *(u32*)(skb->nh.raw + serr->addr_offset)); 321 } 322 } 323 324 memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err)); 325 sin = &errhdr.offender; 326 sin->sin6_family = AF_UNSPEC; 327 if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) { 328 sin->sin6_family = AF_INET6; 329 sin->sin6_flowinfo = 0; 330 sin->sin6_scope_id = 0; 331 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) { 332 ipv6_addr_copy(&sin->sin6_addr, &skb->nh.ipv6h->saddr); 333 if (np->rxopt.all) 334 datagram_recv_ctl(sk, msg, skb); 335 if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL) 336 sin->sin6_scope_id = IP6CB(skb)->iif; 337 } else { 338 struct inet_sock *inet = inet_sk(sk); 339 340 ipv6_addr_set(&sin->sin6_addr, 0, 0, 341 htonl(0xffff), 342 skb->nh.iph->saddr); 343 if (inet->cmsg_flags) 344 ip_cmsg_recv(msg, skb); 345 } 346 } 347 348 put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr); 349 350 /* Now we could try to dump offended packet options */ 351 352 msg->msg_flags |= MSG_ERRQUEUE; 353 err = copied; 354 355 /* Reset and regenerate socket error */ 356 spin_lock_bh(&sk->sk_error_queue.lock); 357 sk->sk_err = 0; 358 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { 359 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; 360 spin_unlock_bh(&sk->sk_error_queue.lock); 361 sk->sk_error_report(sk); 362 } else { 363 spin_unlock_bh(&sk->sk_error_queue.lock); 364 } 365 366 out_free_skb: 367 kfree_skb(skb); 368 out: 369 return err; 370 } 371 372 373 374 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb) 375 { 376 struct ipv6_pinfo *np = inet6_sk(sk); 377 struct inet6_skb_parm *opt = IP6CB(skb); 378 379 if (np->rxopt.bits.rxinfo) { 380 struct in6_pktinfo src_info; 381 382 src_info.ipi6_ifindex = opt->iif; 383 ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr); 384 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info); 385 } 386 387 if (np->rxopt.bits.rxhlim) { 388 int hlim = skb->nh.ipv6h->hop_limit; 389 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim); 390 } 391 392 if (np->rxopt.bits.rxflow && (*(u32*)skb->nh.raw & IPV6_FLOWINFO_MASK)) { 393 u32 flowinfo = *(u32*)skb->nh.raw & IPV6_FLOWINFO_MASK; 394 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo); 395 } 396 if (np->rxopt.bits.hopopts && opt->hop) { 397 u8 *ptr = skb->nh.raw + opt->hop; 398 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr); 399 } 400 if (np->rxopt.bits.dstopts && opt->dst0) { 401 u8 *ptr = skb->nh.raw + opt->dst0; 402 put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, (ptr[1]+1)<<3, ptr); 403 } 404 if (np->rxopt.bits.srcrt && opt->srcrt) { 405 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(skb->nh.raw + opt->srcrt); 406 put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, (rthdr->hdrlen+1) << 3, rthdr); 407 } 408 if (np->rxopt.bits.dstopts && opt->dst1) { 409 u8 *ptr = skb->nh.raw + opt->dst1; 410 put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, (ptr[1]+1)<<3, ptr); 411 } 412 return 0; 413 } 414 415 int datagram_send_ctl(struct msghdr *msg, struct flowi *fl, 416 struct ipv6_txoptions *opt, 417 int *hlimit) 418 { 419 struct in6_pktinfo *src_info; 420 struct cmsghdr *cmsg; 421 struct ipv6_rt_hdr *rthdr; 422 struct ipv6_opt_hdr *hdr; 423 int len; 424 int err = 0; 425 426 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { 427 int addr_type; 428 struct net_device *dev = NULL; 429 430 if (!CMSG_OK(msg, cmsg)) { 431 err = -EINVAL; 432 goto exit_f; 433 } 434 435 if (cmsg->cmsg_level != SOL_IPV6) 436 continue; 437 438 switch (cmsg->cmsg_type) { 439 case IPV6_PKTINFO: 440 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) { 441 err = -EINVAL; 442 goto exit_f; 443 } 444 445 src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg); 446 447 if (src_info->ipi6_ifindex) { 448 if (fl->oif && src_info->ipi6_ifindex != fl->oif) 449 return -EINVAL; 450 fl->oif = src_info->ipi6_ifindex; 451 } 452 453 addr_type = ipv6_addr_type(&src_info->ipi6_addr); 454 455 if (addr_type == IPV6_ADDR_ANY) 456 break; 457 458 if (addr_type & IPV6_ADDR_LINKLOCAL) { 459 if (!src_info->ipi6_ifindex) 460 return -EINVAL; 461 else { 462 dev = dev_get_by_index(src_info->ipi6_ifindex); 463 if (!dev) 464 return -ENODEV; 465 } 466 } 467 if (!ipv6_chk_addr(&src_info->ipi6_addr, dev, 0)) { 468 if (dev) 469 dev_put(dev); 470 err = -EINVAL; 471 goto exit_f; 472 } 473 if (dev) 474 dev_put(dev); 475 476 ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr); 477 break; 478 479 case IPV6_FLOWINFO: 480 if (cmsg->cmsg_len < CMSG_LEN(4)) { 481 err = -EINVAL; 482 goto exit_f; 483 } 484 485 if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) { 486 if ((fl->fl6_flowlabel^*(u32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) { 487 err = -EINVAL; 488 goto exit_f; 489 } 490 } 491 fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(u32 *)CMSG_DATA(cmsg); 492 break; 493 494 case IPV6_HOPOPTS: 495 if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) { 496 err = -EINVAL; 497 goto exit_f; 498 } 499 500 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg); 501 len = ((hdr->hdrlen + 1) << 3); 502 if (cmsg->cmsg_len < CMSG_LEN(len)) { 503 err = -EINVAL; 504 goto exit_f; 505 } 506 if (!capable(CAP_NET_RAW)) { 507 err = -EPERM; 508 goto exit_f; 509 } 510 opt->opt_nflen += len; 511 opt->hopopt = hdr; 512 break; 513 514 case IPV6_DSTOPTS: 515 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) { 516 err = -EINVAL; 517 goto exit_f; 518 } 519 520 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg); 521 len = ((hdr->hdrlen + 1) << 3); 522 if (cmsg->cmsg_len < CMSG_LEN(len)) { 523 err = -EINVAL; 524 goto exit_f; 525 } 526 if (!capable(CAP_NET_RAW)) { 527 err = -EPERM; 528 goto exit_f; 529 } 530 if (opt->dst1opt) { 531 err = -EINVAL; 532 goto exit_f; 533 } 534 opt->opt_flen += len; 535 opt->dst1opt = hdr; 536 break; 537 538 case IPV6_RTHDR: 539 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) { 540 err = -EINVAL; 541 goto exit_f; 542 } 543 544 rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg); 545 546 /* 547 * TYPE 0 548 */ 549 if (rthdr->type) { 550 err = -EINVAL; 551 goto exit_f; 552 } 553 554 len = ((rthdr->hdrlen + 1) << 3); 555 556 if (cmsg->cmsg_len < CMSG_LEN(len)) { 557 err = -EINVAL; 558 goto exit_f; 559 } 560 561 /* segments left must also match */ 562 if ((rthdr->hdrlen >> 1) != rthdr->segments_left) { 563 err = -EINVAL; 564 goto exit_f; 565 } 566 567 opt->opt_nflen += len; 568 opt->srcrt = rthdr; 569 570 if (opt->dst1opt) { 571 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3); 572 573 opt->opt_nflen += dsthdrlen; 574 opt->dst0opt = opt->dst1opt; 575 opt->dst1opt = NULL; 576 opt->opt_flen -= dsthdrlen; 577 } 578 579 break; 580 581 case IPV6_HOPLIMIT: 582 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) { 583 err = -EINVAL; 584 goto exit_f; 585 } 586 587 *hlimit = *(int *)CMSG_DATA(cmsg); 588 break; 589 590 default: 591 LIMIT_NETDEBUG( 592 printk(KERN_DEBUG "invalid cmsg type: %d\n", cmsg->cmsg_type)); 593 err = -EINVAL; 594 break; 595 }; 596 } 597 598 exit_f: 599 return err; 600 } 601