net/ipv4/ip_sockglue.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              The IP to API glue.
   7  *
   8  * Authors:     see ip.c
   9  *
  10  * Fixes:
  11  *              Many            :       Split from ip.c , see ip.c for history.
  12  *              Martin Mares    :       TOS setting fixed.
  13  *              Alan Cox        :       Fixed a couple of oopses in Martin's
  14  *                                      TOS tweaks.
  15  *              Mike McLagan    :       Routing by source
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/types.h>
  20 #include <linux/mm.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/ip.h>
  23 #include <linux/icmp.h>
  24 #include <linux/inetdevice.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/slab.h>
  27 #include <net/sock.h>
  28 #include <net/ip.h>
  29 #include <net/icmp.h>
  30 #include <net/tcp_states.h>
  31 #include <linux/udp.h>
  32 #include <linux/igmp.h>
  33 #include <linux/netfilter.h>
  34 #include <linux/route.h>
  35 #include <linux/mroute.h>
  36 #include <net/inet_ecn.h>
  37 #include <net/route.h>
  38 #include <net/xfrm.h>
  39 #include <net/compat.h>
  40 #include <net/checksum.h>
  41 #if IS_ENABLED(CONFIG_IPV6)
  42 #include <net/transp_v6.h>
  43 #endif
  44 #include <net/ip_fib.h>
  45
  46 #include <linux/errqueue.h>
  47 #include <asm/uaccess.h>
  48
  49 /*
  50  *      SOL_IP control messages.
  51  */
  52
  53 static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
  54 {
  55         struct in_pktinfo info = *PKTINFO_SKB_CB(skb);
  56
  57         info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
  58
  59         put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
  60 }
  61
  62 static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
  63 {
  64         int ttl = ip_hdr(skb)->ttl;
  65         put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
  66 }
  67
  68 static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
  69 {
  70         put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
  71 }
  72
  73 static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
  74 {
  75         if (IPCB(skb)->opt.optlen == 0)
  76                 return;
  77
  78         put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
  79                  ip_hdr(skb) + 1);
  80 }
  81
  82
  83 static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
  84 {
  85         unsigned char optbuf[sizeof(struct ip_options) + 40];
  86         struct ip_options *opt = (struct ip_options *)optbuf;
  87
  88         if (IPCB(skb)->opt.optlen == 0)
  89                 return;
  90
  91         if (ip_options_echo(opt, skb)) {
  92                 msg->msg_flags |= MSG_CTRUNC;
  93                 return;
  94         }
  95         ip_options_undo(opt);
  96
  97         put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
  98 }
  99
 100 static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
 101                                   int offset)
 102 {
 103         __wsum csum = skb->csum;
 104
 105         if (skb->ip_summed != CHECKSUM_COMPLETE)
 106                 return;
 107
 108         if (offset != 0)
 109                 csum = csum_sub(csum, csum_partial(skb->data, offset, 0));
 110
 111         put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum);
 112 }
 113
 114 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 115 {
 116         char *secdata;
 117         u32 seclen, secid;
 118         int err;
 119
 120         err = security_socket_getpeersec_dgram(NULL, skb, &secid);
 121         if (err)
 122                 return;
 123
 124         err = security_secid_to_secctx(secid, &secdata, &seclen);
 125         if (err)
 126                 return;
 127
 128         put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
 129         security_release_secctx(secdata, seclen);
 130 }
 131
 132 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
 133 {
 134         struct sockaddr_in sin;
 135         const struct iphdr *iph = ip_hdr(skb);
 136         __be16 *ports = (__be16 *)skb_transport_header(skb);
 137
 138         if (skb_transport_offset(skb) + 4 > skb->len)
 139                 return;
 140
 141         /* All current transport protocols have the port numbers in the
 142          * first four bytes of the transport header and this function is
 143          * written with this assumption in mind.
 144          */
 145
 146         sin.sin_family = AF_INET;
 147         sin.sin_addr.s_addr = iph->daddr;
 148         sin.sin_port = ports[1];
 149         memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
 150
 151         put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
 152 }
 153
 154 void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb,
 155                          int offset)
 156 {
 157         struct inet_sock *inet = inet_sk(skb->sk);
 158         unsigned int flags = inet->cmsg_flags;
 159
 160         /* Ordered by supposed usage frequency */
 161         if (flags & IP_CMSG_PKTINFO) {
 162                 ip_cmsg_recv_pktinfo(msg, skb);
 163
 164                 flags &= ~IP_CMSG_PKTINFO;
 165                 if (!flags)
 166                         return;
 167         }
 168
 169         if (flags & IP_CMSG_TTL) {
 170                 ip_cmsg_recv_ttl(msg, skb);
 171
 172                 flags &= ~IP_CMSG_TTL;
 173                 if (!flags)
 174                         return;
 175         }
 176
 177         if (flags & IP_CMSG_TOS) {
 178                 ip_cmsg_recv_tos(msg, skb);
 179
 180                 flags &= ~IP_CMSG_TOS;
 181                 if (!flags)
 182                         return;
 183         }
 184
 185         if (flags & IP_CMSG_RECVOPTS) {
 186                 ip_cmsg_recv_opts(msg, skb);
 187
 188                 flags &= ~IP_CMSG_RECVOPTS;
 189                 if (!flags)
 190                         return;
 191         }
 192
 193         if (flags & IP_CMSG_RETOPTS) {
 194                 ip_cmsg_recv_retopts(msg, skb);
 195
 196                 flags &= ~IP_CMSG_RETOPTS;
 197                 if (!flags)
 198                         return;
 199         }
 200
 201         if (flags & IP_CMSG_PASSSEC) {
 202                 ip_cmsg_recv_security(msg, skb);
 203
 204                 flags &= ~IP_CMSG_PASSSEC;
 205                 if (!flags)
 206                         return;
 207         }
 208
 209         if (flags & IP_CMSG_ORIGDSTADDR) {
 210                 ip_cmsg_recv_dstaddr(msg, skb);
 211
 212                 flags &= ~IP_CMSG_ORIGDSTADDR;
 213                 if (!flags)
 214                         return;
 215         }
 216
 217         if (flags & IP_CMSG_CHECKSUM)
 218                 ip_cmsg_recv_checksum(msg, skb, offset);
 219 }
 220 EXPORT_SYMBOL(ip_cmsg_recv_offset);
 221
 222 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc,
 223                  bool allow_ipv6)
 224 {
 225         int err, val;
 226         struct cmsghdr *cmsg;
 227
 228         for_each_cmsghdr(cmsg, msg) {
 229                 if (!CMSG_OK(msg, cmsg))
 230                         return -EINVAL;
 231 #if IS_ENABLED(CONFIG_IPV6)
 232                 if (allow_ipv6 &&
 233                     cmsg->cmsg_level == SOL_IPV6 &&
 234                     cmsg->cmsg_type == IPV6_PKTINFO) {
 235                         struct in6_pktinfo *src_info;
 236
 237                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info)))
 238                                 return -EINVAL;
 239                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 240                         if (!ipv6_addr_v4mapped(&src_info->ipi6_addr))
 241                                 return -EINVAL;
 242                         ipc->oif = src_info->ipi6_ifindex;
 243                         ipc->addr = src_info->ipi6_addr.s6_addr32[3];
 244                         continue;
 245                 }
 246 #endif
 247                 if (cmsg->cmsg_level != SOL_IP)
 248                         continue;
 249                 switch (cmsg->cmsg_type) {
 250                 case IP_RETOPTS:
 251                         err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
 252                         err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
 253                                              err < 40 ? err : 40);
 254                         if (err)
 255                                 return err;
 256                         break;
 257                 case IP_PKTINFO:
 258                 {
 259                         struct in_pktinfo *info;
 260                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
 261                                 return -EINVAL;
 262                         info = (struct in_pktinfo *)CMSG_DATA(cmsg);
 263                         ipc->oif = info->ipi_ifindex;
 264                         ipc->addr = info->ipi_spec_dst.s_addr;
 265                         break;
 266                 }
 267                 case IP_TTL:
 268                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 269                                 return -EINVAL;
 270                         val = *(int *)CMSG_DATA(cmsg);
 271                         if (val < 1 || val > 255)
 272                                 return -EINVAL;
 273                         ipc->ttl = val;
 274                         break;
 275                 case IP_TOS:
 276                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 277                                 return -EINVAL;
 278                         val = *(int *)CMSG_DATA(cmsg);
 279                         if (val < 0 || val > 255)
 280                                 return -EINVAL;
 281                         ipc->tos = val;
 282                         ipc->priority = rt_tos2priority(ipc->tos);
 283                         break;
 284
 285                 default:
 286                         return -EINVAL;
 287                 }
 288         }
 289         return 0;
 290 }
 291
 292
 293 /* Special input handler for packets caught by router alert option.
 294    They are selected only by protocol field, and then processed likely
 295    local ones; but only if someone wants them! Otherwise, router
 296    not running rsvpd will kill RSVP.
 297
 298    It is user level problem, what it will make with them.
 299    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
 300    but receiver should be enough clever f.e. to forward mtrace requests,
 301    sent to multicast group to reach destination designated router.
 302  */
 303 struct ip_ra_chain __rcu *ip_ra_chain;
 304 static DEFINE_SPINLOCK(ip_ra_lock);
 305
 306
 307 static void ip_ra_destroy_rcu(struct rcu_head *head)
 308 {
 309         struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
 310
 311         sock_put(ra->saved_sk);
 312         kfree(ra);
 313 }
 314
 315 int ip_ra_control(struct sock *sk, unsigned char on,
 316                   void (*destructor)(struct sock *))
 317 {
 318         struct ip_ra_chain *ra, *new_ra;
 319         struct ip_ra_chain __rcu **rap;
 320
 321         if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
 322                 return -EINVAL;
 323
 324         new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
 325
 326         spin_lock_bh(&ip_ra_lock);
 327         for (rap = &ip_ra_chain;
 328              (ra = rcu_dereference_protected(*rap,
 329                         lockdep_is_held(&ip_ra_lock))) != NULL;
 330              rap = &ra->next) {
 331                 if (ra->sk == sk) {
 332                         if (on) {
 333                                 spin_unlock_bh(&ip_ra_lock);
 334                                 kfree(new_ra);
 335                                 return -EADDRINUSE;
 336                         }
 337                         /* dont let ip_call_ra_chain() use sk again */
 338                         ra->sk = NULL;
 339                         RCU_INIT_POINTER(*rap, ra->next);
 340                         spin_unlock_bh(&ip_ra_lock);
 341
 342                         if (ra->destructor)
 343                                 ra->destructor(sk);
 344                         /*
 345                          * Delay sock_put(sk) and kfree(ra) after one rcu grace
 346                          * period. This guarantee ip_call_ra_chain() dont need
 347                          * to mess with socket refcounts.
 348                          */
 349                         ra->saved_sk = sk;
 350                         call_rcu(&ra->rcu, ip_ra_destroy_rcu);
 351                         return 0;
 352                 }
 353         }
 354         if (new_ra == NULL) {
 355                 spin_unlock_bh(&ip_ra_lock);
 356                 return -ENOBUFS;
 357         }
 358         new_ra->sk = sk;
 359         new_ra->destructor = destructor;
 360
 361         RCU_INIT_POINTER(new_ra->next, ra);
 362         rcu_assign_pointer(*rap, new_ra);
 363         sock_hold(sk);
 364         spin_unlock_bh(&ip_ra_lock);
 365
 366         return 0;
 367 }
 368
 369 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 370                    __be16 port, u32 info, u8 *payload)
 371 {
 372         struct sock_exterr_skb *serr;
 373
 374         skb = skb_clone(skb, GFP_ATOMIC);
 375         if (!skb)
 376                 return;
 377
 378         serr = SKB_EXT_ERR(skb);
 379         serr->ee.ee_errno = err;
 380         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
 381         serr->ee.ee_type = icmp_hdr(skb)->type;
 382         serr->ee.ee_code = icmp_hdr(skb)->code;
 383         serr->ee.ee_pad = 0;
 384         serr->ee.ee_info = info;
 385         serr->ee.ee_data = 0;
 386         serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
 387                                    skb_network_header(skb);
 388         serr->port = port;
 389
 390         if (skb_pull(skb, payload - skb->data) != NULL) {
 391                 skb_reset_transport_header(skb);
 392                 if (sock_queue_err_skb(sk, skb) == 0)
 393                         return;
 394         }
 395         kfree_skb(skb);
 396 }
 397
 398 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
 399 {
 400         struct inet_sock *inet = inet_sk(sk);
 401         struct sock_exterr_skb *serr;
 402         struct iphdr *iph;
 403         struct sk_buff *skb;
 404
 405         if (!inet->recverr)
 406                 return;
 407
 408         skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
 409         if (!skb)
 410                 return;
 411
 412         skb_put(skb, sizeof(struct iphdr));
 413         skb_reset_network_header(skb);
 414         iph = ip_hdr(skb);
 415         iph->daddr = daddr;
 416
 417         serr = SKB_EXT_ERR(skb);
 418         serr->ee.ee_errno = err;
 419         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 420         serr->ee.ee_type = 0;
 421         serr->ee.ee_code = 0;
 422         serr->ee.ee_pad = 0;
 423         serr->ee.ee_info = info;
 424         serr->ee.ee_data = 0;
 425         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 426         serr->port = port;
 427
 428         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 429         skb_reset_transport_header(skb);
 430
 431         if (sock_queue_err_skb(sk, skb))
 432                 kfree_skb(skb);
 433 }
 434
 435 static bool ipv4_pktinfo_prepare_errqueue(const struct sock *sk,
 436                                           const struct sk_buff *skb,
 437                                           int ee_origin)
 438 {
 439         struct in_pktinfo *info = PKTINFO_SKB_CB(skb);
 440
 441         if ((ee_origin != SO_EE_ORIGIN_TIMESTAMPING) ||
 442             (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG)) ||
 443             (!skb->dev))
 444                 return false;
 445
 446         info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
 447         info->ipi_ifindex = skb->dev->ifindex;
 448         return true;
 449 }
 450
 451 /*
 452  *      Handle MSG_ERRQUEUE
 453  */
 454 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 455 {
 456         struct sock_exterr_skb *serr;
 457         struct sk_buff *skb;
 458         DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 459         struct {
 460                 struct sock_extended_err ee;
 461                 struct sockaddr_in       offender;
 462         } errhdr;
 463         int err;
 464         int copied;
 465
 466         WARN_ON_ONCE(sk->sk_family == AF_INET6);
 467
 468         err = -EAGAIN;
 469         skb = sock_dequeue_err_skb(sk);
 470         if (skb == NULL)
 471                 goto out;
 472
 473         copied = skb->len;
 474         if (copied > len) {
 475                 msg->msg_flags |= MSG_TRUNC;
 476                 copied = len;
 477         }
 478         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 479         if (err)
 480                 goto out_free_skb;
 481
 482         sock_recv_timestamp(msg, sk, skb);
 483
 484         serr = SKB_EXT_ERR(skb);
 485
 486         if (sin && skb->len) {
 487                 sin->sin_family = AF_INET;
 488                 sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
 489                                                    serr->addr_offset);
 490                 sin->sin_port = serr->port;
 491                 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
 492                 *addr_len = sizeof(*sin);
 493         }
 494
 495         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 496         sin = &errhdr.offender;
 497         memset(sin, 0, sizeof(*sin));
 498
 499         if (skb->len &&
 500             (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 501              ipv4_pktinfo_prepare_errqueue(sk, skb, serr->ee.ee_origin))) {
 502                 sin->sin_family = AF_INET;
 503                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 504                 if (inet_sk(sk)->cmsg_flags)
 505                         ip_cmsg_recv(msg, skb);
 506         }
 507
 508         put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
 509
 510         /* Now we could try to dump offended packet options */
 511
 512         msg->msg_flags |= MSG_ERRQUEUE;
 513         err = copied;
 514
 515 out_free_skb:
 516         kfree_skb(skb);
 517 out:
 518         return err;
 519 }
 520
 521
 522 /*
 523  *      Socket option code for IP. This is the end of the line after any
 524  *      TCP,UDP etc options on an IP socket.
 525  */
 526
 527 static int do_ip_setsockopt(struct sock *sk, int level,
 528                             int optname, char __user *optval, unsigned int optlen)
 529 {
 530         struct inet_sock *inet = inet_sk(sk);
 531         int val = 0, err;
 532
 533         switch (optname) {
 534         case IP_PKTINFO:
 535         case IP_RECVTTL:
 536         case IP_RECVOPTS:
 537         case IP_RECVTOS:
 538         case IP_RETOPTS:
 539         case IP_TOS:
 540         case IP_TTL:
 541         case IP_HDRINCL:
 542         case IP_MTU_DISCOVER:
 543         case IP_RECVERR:
 544         case IP_ROUTER_ALERT:
 545         case IP_FREEBIND:
 546         case IP_PASSSEC:
 547         case IP_TRANSPARENT:
 548         case IP_MINTTL:
 549         case IP_NODEFRAG:
 550         case IP_UNICAST_IF:
 551         case IP_MULTICAST_TTL:
 552         case IP_MULTICAST_ALL:
 553         case IP_MULTICAST_LOOP:
 554         case IP_RECVORIGDSTADDR:
 555         case IP_CHECKSUM:
 556                 if (optlen >= sizeof(int)) {
 557                         if (get_user(val, (int __user *) optval))
 558                                 return -EFAULT;
 559                 } else if (optlen >= sizeof(char)) {
 560                         unsigned char ucval;
 561
 562                         if (get_user(ucval, (unsigned char __user *) optval))
 563                                 return -EFAULT;
 564                         val = (int) ucval;
 565                 }
 566         }
 567
 568         /* If optlen==0, it is equivalent to val == 0 */
 569
 570         if (ip_mroute_opt(optname))
 571                 return ip_mroute_setsockopt(sk, optname, optval, optlen);
 572
 573         err = 0;
 574         lock_sock(sk);
 575
 576         switch (optname) {
 577         case IP_OPTIONS:
 578         {
 579                 struct ip_options_rcu *old, *opt = NULL;
 580
 581                 if (optlen > 40)
 582                         goto e_inval;
 583                 err = ip_options_get_from_user(sock_net(sk), &opt,
 584                                                optval, optlen);
 585                 if (err)
 586                         break;
 587                 old = rcu_dereference_protected(inet->inet_opt,
 588                                                 sock_owned_by_user(sk));
 589                 if (inet->is_icsk) {
 590                         struct inet_connection_sock *icsk = inet_csk(sk);
 591 #if IS_ENABLED(CONFIG_IPV6)
 592                         if (sk->sk_family == PF_INET ||
 593                             (!((1 << sk->sk_state) &
 594                                (TCPF_LISTEN | TCPF_CLOSE)) &&
 595                              inet->inet_daddr != LOOPBACK4_IPV6)) {
 596 #endif
 597                                 if (old)
 598                                         icsk->icsk_ext_hdr_len -= old->opt.optlen;
 599                                 if (opt)
 600                                         icsk->icsk_ext_hdr_len += opt->opt.optlen;
 601                                 icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
 602 #if IS_ENABLED(CONFIG_IPV6)
 603                         }
 604 #endif
 605                 }
 606                 rcu_assign_pointer(inet->inet_opt, opt);
 607                 if (old)
 608                         kfree_rcu(old, rcu);
 609                 break;
 610         }
 611         case IP_PKTINFO:
 612                 if (val)
 613                         inet->cmsg_flags |= IP_CMSG_PKTINFO;
 614                 else
 615                         inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
 616                 break;
 617         case IP_RECVTTL:
 618                 if (val)
 619                         inet->cmsg_flags |=  IP_CMSG_TTL;
 620                 else
 621                         inet->cmsg_flags &= ~IP_CMSG_TTL;
 622                 break;
 623         case IP_RECVTOS:
 624                 if (val)
 625                         inet->cmsg_flags |=  IP_CMSG_TOS;
 626                 else
 627                         inet->cmsg_flags &= ~IP_CMSG_TOS;
 628                 break;
 629         case IP_RECVOPTS:
 630                 if (val)
 631                         inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
 632                 else
 633                         inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
 634                 break;
 635         case IP_RETOPTS:
 636                 if (val)
 637                         inet->cmsg_flags |= IP_CMSG_RETOPTS;
 638                 else
 639                         inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
 640                 break;
 641         case IP_PASSSEC:
 642                 if (val)
 643                         inet->cmsg_flags |= IP_CMSG_PASSSEC;
 644                 else
 645                         inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
 646                 break;
 647         case IP_RECVORIGDSTADDR:
 648                 if (val)
 649                         inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
 650                 else
 651                         inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
 652                 break;
 653         case IP_CHECKSUM:
 654                 if (val) {
 655                         if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
 656                                 inet_inc_convert_csum(sk);
 657                                 inet->cmsg_flags |= IP_CMSG_CHECKSUM;
 658                         }
 659                 } else {
 660                         if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
 661                                 inet_dec_convert_csum(sk);
 662                                 inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
 663                         }
 664                 }
 665                 break;
 666         case IP_TOS:    /* This sets both TOS and Precedence */
 667                 if (sk->sk_type == SOCK_STREAM) {
 668                         val &= ~INET_ECN_MASK;
 669                         val |= inet->tos & INET_ECN_MASK;
 670                 }
 671                 if (inet->tos != val) {
 672                         inet->tos = val;
 673                         sk->sk_priority = rt_tos2priority(val);
 674                         sk_dst_reset(sk);
 675                 }
 676                 break;
 677         case IP_TTL:
 678                 if (optlen < 1)
 679                         goto e_inval;
 680                 if (val != -1 && (val < 1 || val > 255))
 681                         goto e_inval;
 682                 inet->uc_ttl = val;
 683                 break;
 684         case IP_HDRINCL:
 685                 if (sk->sk_type != SOCK_RAW) {
 686                         err = -ENOPROTOOPT;
 687                         break;
 688                 }
 689                 inet->hdrincl = val ? 1 : 0;
 690                 break;
 691         case IP_NODEFRAG:
 692                 if (sk->sk_type != SOCK_RAW) {
 693                         err = -ENOPROTOOPT;
 694                         break;
 695                 }
 696                 inet->nodefrag = val ? 1 : 0;
 697                 break;
 698         case IP_MTU_DISCOVER:
 699                 if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
 700                         goto e_inval;
 701                 inet->pmtudisc = val;
 702                 break;
 703         case IP_RECVERR:
 704                 inet->recverr = !!val;
 705                 if (!val)
 706                         skb_queue_purge(&sk->sk_error_queue);
 707                 break;
 708         case IP_MULTICAST_TTL:
 709                 if (sk->sk_type == SOCK_STREAM)
 710                         goto e_inval;
 711                 if (optlen < 1)
 712                         goto e_inval;
 713                 if (val == -1)
 714                         val = 1;
 715                 if (val < 0 || val > 255)
 716                         goto e_inval;
 717                 inet->mc_ttl = val;
 718                 break;
 719         case IP_MULTICAST_LOOP:
 720                 if (optlen < 1)
 721                         goto e_inval;
 722                 inet->mc_loop = !!val;
 723                 break;
 724         case IP_UNICAST_IF:
 725         {
 726                 struct net_device *dev = NULL;
 727                 int ifindex;
 728
 729                 if (optlen != sizeof(int))
 730                         goto e_inval;
 731
 732                 ifindex = (__force int)ntohl((__force __be32)val);
 733                 if (ifindex == 0) {
 734                         inet->uc_index = 0;
 735                         err = 0;
 736                         break;
 737                 }
 738
 739                 dev = dev_get_by_index(sock_net(sk), ifindex);
 740                 err = -EADDRNOTAVAIL;
 741                 if (!dev)
 742                         break;
 743                 dev_put(dev);
 744
 745                 err = -EINVAL;
 746                 if (sk->sk_bound_dev_if)
 747                         break;
 748
 749                 inet->uc_index = ifindex;
 750                 err = 0;
 751                 break;
 752         }
 753         case IP_MULTICAST_IF:
 754         {
 755                 struct ip_mreqn mreq;
 756                 struct net_device *dev = NULL;
 757
 758                 if (sk->sk_type == SOCK_STREAM)
 759                         goto e_inval;
 760                 /*
 761                  *      Check the arguments are allowable
 762                  */
 763
 764                 if (optlen < sizeof(struct in_addr))
 765                         goto e_inval;
 766
 767                 err = -EFAULT;
 768                 if (optlen >= sizeof(struct ip_mreqn)) {
 769                         if (copy_from_user(&mreq, optval, sizeof(mreq)))
 770                                 break;
 771                 } else {
 772                         memset(&mreq, 0, sizeof(mreq));
 773                         if (optlen >= sizeof(struct ip_mreq)) {
 774                                 if (copy_from_user(&mreq, optval,
 775                                                    sizeof(struct ip_mreq)))
 776                                         break;
 777                         } else if (optlen >= sizeof(struct in_addr)) {
 778                                 if (copy_from_user(&mreq.imr_address, optval,
 779                                                    sizeof(struct in_addr)))
 780                                         break;
 781                         }
 782                 }
 783
 784                 if (!mreq.imr_ifindex) {
 785                         if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
 786                                 inet->mc_index = 0;
 787                                 inet->mc_addr  = 0;
 788                                 err = 0;
 789                                 break;
 790                         }
 791                         dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
 792                         if (dev)
 793                                 mreq.imr_ifindex = dev->ifindex;
 794                 } else
 795                         dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
 796
 797
 798                 err = -EADDRNOTAVAIL;
 799                 if (!dev)
 800                         break;
 801                 dev_put(dev);
 802
 803                 err = -EINVAL;
 804                 if (sk->sk_bound_dev_if &&
 805                     mreq.imr_ifindex != sk->sk_bound_dev_if)
 806                         break;
 807
 808                 inet->mc_index = mreq.imr_ifindex;
 809                 inet->mc_addr  = mreq.imr_address.s_addr;
 810                 err = 0;
 811                 break;
 812         }
 813
 814         case IP_ADD_MEMBERSHIP:
 815         case IP_DROP_MEMBERSHIP:
 816         {
 817                 struct ip_mreqn mreq;
 818
 819                 err = -EPROTO;
 820                 if (inet_sk(sk)->is_icsk)
 821                         break;
 822
 823                 if (optlen < sizeof(struct ip_mreq))
 824                         goto e_inval;
 825                 err = -EFAULT;
 826                 if (optlen >= sizeof(struct ip_mreqn)) {
 827                         if (copy_from_user(&mreq, optval, sizeof(mreq)))
 828                                 break;
 829                 } else {
 830                         memset(&mreq, 0, sizeof(mreq));
 831                         if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
 832                                 break;
 833                 }
 834
 835                 if (optname == IP_ADD_MEMBERSHIP)
 836                         err = ip_mc_join_group(sk, &mreq);
 837                 else
 838                         err = ip_mc_leave_group(sk, &mreq);
 839                 break;
 840         }
 841         case IP_MSFILTER:
 842         {
 843                 struct ip_msfilter *msf;
 844
 845                 if (optlen < IP_MSFILTER_SIZE(0))
 846                         goto e_inval;
 847                 if (optlen > sysctl_optmem_max) {
 848                         err = -ENOBUFS;
 849                         break;
 850                 }
 851                 msf = kmalloc(optlen, GFP_KERNEL);
 852                 if (!msf) {
 853                         err = -ENOBUFS;
 854                         break;
 855                 }
 856                 err = -EFAULT;
 857                 if (copy_from_user(msf, optval, optlen)) {
 858                         kfree(msf);
 859                         break;
 860                 }
 861                 /* numsrc >= (1G-4) overflow in 32 bits */
 862                 if (msf->imsf_numsrc >= 0x3ffffffcU ||
 863                     msf->imsf_numsrc > sysctl_igmp_max_msf) {
 864                         kfree(msf);
 865                         err = -ENOBUFS;
 866                         break;
 867                 }
 868                 if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
 869                         kfree(msf);
 870                         err = -EINVAL;
 871                         break;
 872                 }
 873                 err = ip_mc_msfilter(sk, msf, 0);
 874                 kfree(msf);
 875                 break;
 876         }
 877         case IP_BLOCK_SOURCE:
 878         case IP_UNBLOCK_SOURCE:
 879         case IP_ADD_SOURCE_MEMBERSHIP:
 880         case IP_DROP_SOURCE_MEMBERSHIP:
 881         {
 882                 struct ip_mreq_source mreqs;
 883                 int omode, add;
 884
 885                 if (optlen != sizeof(struct ip_mreq_source))
 886                         goto e_inval;
 887                 if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
 888                         err = -EFAULT;
 889                         break;
 890                 }
 891                 if (optname == IP_BLOCK_SOURCE) {
 892                         omode = MCAST_EXCLUDE;
 893                         add = 1;
 894                 } else if (optname == IP_UNBLOCK_SOURCE) {
 895                         omode = MCAST_EXCLUDE;
 896                         add = 0;
 897                 } else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
 898                         struct ip_mreqn mreq;
 899
 900                         mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
 901                         mreq.imr_address.s_addr = mreqs.imr_interface;
 902                         mreq.imr_ifindex = 0;
 903                         err = ip_mc_join_group(sk, &mreq);
 904                         if (err && err != -EADDRINUSE)
 905                                 break;
 906                         omode = MCAST_INCLUDE;
 907                         add = 1;
 908                 } else /* IP_DROP_SOURCE_MEMBERSHIP */ {
 909                         omode = MCAST_INCLUDE;
 910                         add = 0;
 911                 }
 912                 err = ip_mc_source(add, omode, sk, &mreqs, 0);
 913                 break;
 914         }
 915         case MCAST_JOIN_GROUP:
 916         case MCAST_LEAVE_GROUP:
 917         {
 918                 struct group_req greq;
 919                 struct sockaddr_in *psin;
 920                 struct ip_mreqn mreq;
 921
 922                 if (optlen < sizeof(struct group_req))
 923                         goto e_inval;
 924                 err = -EFAULT;
 925                 if (copy_from_user(&greq, optval, sizeof(greq)))
 926                         break;
 927                 psin = (struct sockaddr_in *)&greq.gr_group;
 928                 if (psin->sin_family != AF_INET)
 929                         goto e_inval;
 930                 memset(&mreq, 0, sizeof(mreq));
 931                 mreq.imr_multiaddr = psin->sin_addr;
 932                 mreq.imr_ifindex = greq.gr_interface;
 933
 934                 if (optname == MCAST_JOIN_GROUP)
 935                         err = ip_mc_join_group(sk, &mreq);
 936                 else
 937                         err = ip_mc_leave_group(sk, &mreq);
 938                 break;
 939         }
 940         case MCAST_JOIN_SOURCE_GROUP:
 941         case MCAST_LEAVE_SOURCE_GROUP:
 942         case MCAST_BLOCK_SOURCE:
 943         case MCAST_UNBLOCK_SOURCE:
 944         {
 945                 struct group_source_req greqs;
 946                 struct ip_mreq_source mreqs;
 947                 struct sockaddr_in *psin;
 948                 int omode, add;
 949
 950                 if (optlen != sizeof(struct group_source_req))
 951                         goto e_inval;
 952                 if (copy_from_user(&greqs, optval, sizeof(greqs))) {
 953                         err = -EFAULT;
 954                         break;
 955                 }
 956                 if (greqs.gsr_group.ss_family != AF_INET ||
 957                     greqs.gsr_source.ss_family != AF_INET) {
 958                         err = -EADDRNOTAVAIL;
 959                         break;
 960                 }
 961                 psin = (struct sockaddr_in *)&greqs.gsr_group;
 962                 mreqs.imr_multiaddr = psin->sin_addr.s_addr;
 963                 psin = (struct sockaddr_in *)&greqs.gsr_source;
 964                 mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
 965                 mreqs.imr_interface = 0; /* use index for mc_source */
 966
 967                 if (optname == MCAST_BLOCK_SOURCE) {
 968                         omode = MCAST_EXCLUDE;
 969                         add = 1;
 970                 } else if (optname == MCAST_UNBLOCK_SOURCE) {
 971                         omode = MCAST_EXCLUDE;
 972                         add = 0;
 973                 } else if (optname == MCAST_JOIN_SOURCE_GROUP) {
 974                         struct ip_mreqn mreq;
 975
 976                         psin = (struct sockaddr_in *)&greqs.gsr_group;
 977                         mreq.imr_multiaddr = psin->sin_addr;
 978                         mreq.imr_address.s_addr = 0;
 979                         mreq.imr_ifindex = greqs.gsr_interface;
 980                         err = ip_mc_join_group(sk, &mreq);
 981                         if (err && err != -EADDRINUSE)
 982                                 break;
 983                         greqs.gsr_interface = mreq.imr_ifindex;
 984                         omode = MCAST_INCLUDE;
 985                         add = 1;
 986                 } else /* MCAST_LEAVE_SOURCE_GROUP */ {
 987                         omode = MCAST_INCLUDE;
 988                         add = 0;
 989                 }
 990                 err = ip_mc_source(add, omode, sk, &mreqs,
 991                                    greqs.gsr_interface);
 992                 break;
 993         }
 994         case MCAST_MSFILTER:
 995         {
 996                 struct sockaddr_in *psin;
 997                 struct ip_msfilter *msf = NULL;
 998                 struct group_filter *gsf = NULL;
 999                 int msize, i, ifindex;
1000
1001                 if (optlen < GROUP_FILTER_SIZE(0))
1002                         goto e_inval;
1003                 if (optlen > sysctl_optmem_max) {
1004                         err = -ENOBUFS;
1005                         break;
1006                 }
1007                 gsf = kmalloc(optlen, GFP_KERNEL);
1008                 if (!gsf) {
1009                         err = -ENOBUFS;
1010                         break;
1011                 }
1012                 err = -EFAULT;
1013                 if (copy_from_user(gsf, optval, optlen))
1014                         goto mc_msf_out;
1015
1016                 /* numsrc >= (4G-140)/128 overflow in 32 bits */
1017                 if (gsf->gf_numsrc >= 0x1ffffff ||
1018                     gsf->gf_numsrc > sysctl_igmp_max_msf) {
1019                         err = -ENOBUFS;
1020                         goto mc_msf_out;
1021                 }
1022                 if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
1023                         err = -EINVAL;
1024                         goto mc_msf_out;
1025                 }
1026                 msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
1027                 msf = kmalloc(msize, GFP_KERNEL);
1028                 if (!msf) {
1029                         err = -ENOBUFS;
1030                         goto mc_msf_out;
1031                 }
1032                 ifindex = gsf->gf_interface;
1033                 psin = (struct sockaddr_in *)&gsf->gf_group;
1034                 if (psin->sin_family != AF_INET) {
1035                         err = -EADDRNOTAVAIL;
1036                         goto mc_msf_out;
1037                 }
1038                 msf->imsf_multiaddr = psin->sin_addr.s_addr;
1039                 msf->imsf_interface = 0;
1040                 msf->imsf_fmode = gsf->gf_fmode;
1041                 msf->imsf_numsrc = gsf->gf_numsrc;
1042                 err = -EADDRNOTAVAIL;
1043                 for (i = 0; i < gsf->gf_numsrc; ++i) {
1044                         psin = (struct sockaddr_in *)&gsf->gf_slist[i];
1045
1046                         if (psin->sin_family != AF_INET)
1047                                 goto mc_msf_out;
1048                         msf->imsf_slist[i] = psin->sin_addr.s_addr;
1049                 }
1050                 kfree(gsf);
1051                 gsf = NULL;
1052
1053                 err = ip_mc_msfilter(sk, msf, ifindex);
1054 mc_msf_out:
1055                 kfree(msf);
1056                 kfree(gsf);
1057                 break;
1058         }
1059         case IP_MULTICAST_ALL:
1060                 if (optlen < 1)
1061                         goto e_inval;
1062                 if (val != 0 && val != 1)
1063                         goto e_inval;
1064                 inet->mc_all = val;
1065                 break;
1066         case IP_ROUTER_ALERT:
1067                 err = ip_ra_control(sk, val ? 1 : 0, NULL);
1068                 break;
1069
1070         case IP_FREEBIND:
1071                 if (optlen < 1)
1072                         goto e_inval;
1073                 inet->freebind = !!val;
1074                 break;
1075
1076         case IP_IPSEC_POLICY:
1077         case IP_XFRM_POLICY:
1078                 err = -EPERM;
1079                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1080                         break;
1081                 err = xfrm_user_policy(sk, optname, optval, optlen);
1082                 break;
1083
1084         case IP_TRANSPARENT:
1085                 if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1086                     !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1087                         err = -EPERM;
1088                         break;
1089                 }
1090                 if (optlen < 1)
1091                         goto e_inval;
1092                 inet->transparent = !!val;
1093                 break;
1094
1095         case IP_MINTTL:
1096                 if (optlen < 1)
1097                         goto e_inval;
1098                 if (val < 0 || val > 255)
1099                         goto e_inval;
1100                 inet->min_ttl = val;
1101                 break;
1102
1103         default:
1104                 err = -ENOPROTOOPT;
1105                 break;
1106         }
1107         release_sock(sk);
1108         return err;
1109
1110 e_inval:
1111         release_sock(sk);
1112         return -EINVAL;
1113 }
1114
1115 /**
1116  * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1117  * @sk: socket
1118  * @skb: buffer
1119  *
1120  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1121  * destination in skb->cb[] before dst drop.
1122  * This way, receiver doesn't make cache line misses to read rtable.
1123  */
1124 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1125 {
1126         struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1127         bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1128                        ipv6_sk_rxinfo(sk);
1129
1130         if (prepare && skb_rtable(skb)) {
1131                 pktinfo->ipi_ifindex = inet_iif(skb);
1132                 pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1133         } else {
1134                 pktinfo->ipi_ifindex = 0;
1135                 pktinfo->ipi_spec_dst.s_addr = 0;
1136         }
1137         skb_dst_drop(skb);
1138 }
1139
1140 int ip_setsockopt(struct sock *sk, int level,
1141                 int optname, char __user *optval, unsigned int optlen)
1142 {
1143         int err;
1144
1145         if (level != SOL_IP)
1146                 return -ENOPROTOOPT;
1147
1148         err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1149 #ifdef CONFIG_NETFILTER
1150         /* we need to exclude all possible ENOPROTOOPTs except default case */
1151         if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1152                         optname != IP_IPSEC_POLICY &&
1153                         optname != IP_XFRM_POLICY &&
1154                         !ip_mroute_opt(optname)) {
1155                 lock_sock(sk);
1156                 err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1157                 release_sock(sk);
1158         }
1159 #endif
1160         return err;
1161 }
1162 EXPORT_SYMBOL(ip_setsockopt);
1163
1164 #ifdef CONFIG_COMPAT
1165 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1166                          char __user *optval, unsigned int optlen)
1167 {
1168         int err;
1169
1170         if (level != SOL_IP)
1171                 return -ENOPROTOOPT;
1172
1173         if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1174                 return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1175                         ip_setsockopt);
1176
1177         err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1178 #ifdef CONFIG_NETFILTER
1179         /* we need to exclude all possible ENOPROTOOPTs except default case */
1180         if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1181                         optname != IP_IPSEC_POLICY &&
1182                         optname != IP_XFRM_POLICY &&
1183                         !ip_mroute_opt(optname)) {
1184                 lock_sock(sk);
1185                 err = compat_nf_setsockopt(sk, PF_INET, optname,
1186                                            optval, optlen);
1187                 release_sock(sk);
1188         }
1189 #endif
1190         return err;
1191 }
1192 EXPORT_SYMBOL(compat_ip_setsockopt);
1193 #endif
1194
1195 /*
1196  *      Get the options. Note for future reference. The GET of IP options gets
1197  *      the _received_ ones. The set sets the _sent_ ones.
1198  */
1199
1200 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1201                             char __user *optval, int __user *optlen, unsigned int flags)
1202 {
1203         struct inet_sock *inet = inet_sk(sk);
1204         int val;
1205         int len;
1206
1207         if (level != SOL_IP)
1208                 return -EOPNOTSUPP;
1209
1210         if (ip_mroute_opt(optname))
1211                 return ip_mroute_getsockopt(sk, optname, optval, optlen);
1212
1213         if (get_user(len, optlen))
1214                 return -EFAULT;
1215         if (len < 0)
1216                 return -EINVAL;
1217
1218         lock_sock(sk);
1219
1220         switch (optname) {
1221         case IP_OPTIONS:
1222         {
1223                 unsigned char optbuf[sizeof(struct ip_options)+40];
1224                 struct ip_options *opt = (struct ip_options *)optbuf;
1225                 struct ip_options_rcu *inet_opt;
1226
1227                 inet_opt = rcu_dereference_protected(inet->inet_opt,
1228                                                      sock_owned_by_user(sk));
1229                 opt->optlen = 0;
1230                 if (inet_opt)
1231                         memcpy(optbuf, &inet_opt->opt,
1232                                sizeof(struct ip_options) +
1233                                inet_opt->opt.optlen);
1234                 release_sock(sk);
1235
1236                 if (opt->optlen == 0)
1237                         return put_user(0, optlen);
1238
1239                 ip_options_undo(opt);
1240
1241                 len = min_t(unsigned int, len, opt->optlen);
1242                 if (put_user(len, optlen))
1243                         return -EFAULT;
1244                 if (copy_to_user(optval, opt->__data, len))
1245                         return -EFAULT;
1246                 return 0;
1247         }
1248         case IP_PKTINFO:
1249                 val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1250                 break;
1251         case IP_RECVTTL:
1252                 val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1253                 break;
1254         case IP_RECVTOS:
1255                 val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1256                 break;
1257         case IP_RECVOPTS:
1258                 val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1259                 break;
1260         case IP_RETOPTS:
1261                 val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1262                 break;
1263         case IP_PASSSEC:
1264                 val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1265                 break;
1266         case IP_RECVORIGDSTADDR:
1267                 val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1268                 break;
1269         case IP_CHECKSUM:
1270                 val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1271                 break;
1272         case IP_TOS:
1273                 val = inet->tos;
1274                 break;
1275         case IP_TTL:
1276                 val = (inet->uc_ttl == -1 ?
1277                        sysctl_ip_default_ttl :
1278                        inet->uc_ttl);
1279                 break;
1280         case IP_HDRINCL:
1281                 val = inet->hdrincl;
1282                 break;
1283         case IP_NODEFRAG:
1284                 val = inet->nodefrag;
1285                 break;
1286         case IP_MTU_DISCOVER:
1287                 val = inet->pmtudisc;
1288                 break;
1289         case IP_MTU:
1290         {
1291                 struct dst_entry *dst;
1292                 val = 0;
1293                 dst = sk_dst_get(sk);
1294                 if (dst) {
1295                         val = dst_mtu(dst);
1296                         dst_release(dst);
1297                 }
1298                 if (!val) {
1299                         release_sock(sk);
1300                         return -ENOTCONN;
1301                 }
1302                 break;
1303         }
1304         case IP_RECVERR:
1305                 val = inet->recverr;
1306                 break;
1307         case IP_MULTICAST_TTL:
1308                 val = inet->mc_ttl;
1309                 break;
1310         case IP_MULTICAST_LOOP:
1311                 val = inet->mc_loop;
1312                 break;
1313         case IP_UNICAST_IF:
1314                 val = (__force int)htonl((__u32) inet->uc_index);
1315                 break;
1316         case IP_MULTICAST_IF:
1317         {
1318                 struct in_addr addr;
1319                 len = min_t(unsigned int, len, sizeof(struct in_addr));
1320                 addr.s_addr = inet->mc_addr;
1321                 release_sock(sk);
1322
1323                 if (put_user(len, optlen))
1324                         return -EFAULT;
1325                 if (copy_to_user(optval, &addr, len))
1326                         return -EFAULT;
1327                 return 0;
1328         }
1329         case IP_MSFILTER:
1330         {
1331                 struct ip_msfilter msf;
1332                 int err;
1333
1334                 if (len < IP_MSFILTER_SIZE(0)) {
1335                         release_sock(sk);
1336                         return -EINVAL;
1337                 }
1338                 if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1339                         release_sock(sk);
1340                         return -EFAULT;
1341                 }
1342                 err = ip_mc_msfget(sk, &msf,
1343                                    (struct ip_msfilter __user *)optval, optlen);
1344                 release_sock(sk);
1345                 return err;
1346         }
1347         case MCAST_MSFILTER:
1348         {
1349                 struct group_filter gsf;
1350                 int err;
1351
1352                 if (len < GROUP_FILTER_SIZE(0)) {
1353                         release_sock(sk);
1354                         return -EINVAL;
1355                 }
1356                 if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1357                         release_sock(sk);
1358                         return -EFAULT;
1359                 }
1360                 err = ip_mc_gsfget(sk, &gsf,
1361                                    (struct group_filter __user *)optval,
1362                                    optlen);
1363                 release_sock(sk);
1364                 return err;
1365         }
1366         case IP_MULTICAST_ALL:
1367                 val = inet->mc_all;
1368                 break;
1369         case IP_PKTOPTIONS:
1370         {
1371                 struct msghdr msg;
1372
1373                 release_sock(sk);
1374
1375                 if (sk->sk_type != SOCK_STREAM)
1376                         return -ENOPROTOOPT;
1377
1378                 msg.msg_control = (__force void *) optval;
1379                 msg.msg_controllen = len;
1380                 msg.msg_flags = flags;
1381
1382                 if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1383                         struct in_pktinfo info;
1384
1385                         info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1386                         info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1387                         info.ipi_ifindex = inet->mc_index;
1388                         put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1389                 }
1390                 if (inet->cmsg_flags & IP_CMSG_TTL) {
1391                         int hlim = inet->mc_ttl;
1392                         put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1393                 }
1394                 if (inet->cmsg_flags & IP_CMSG_TOS) {
1395                         int tos = inet->rcv_tos;
1396                         put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1397                 }
1398                 len -= msg.msg_controllen;
1399                 return put_user(len, optlen);
1400         }
1401         case IP_FREEBIND:
1402                 val = inet->freebind;
1403                 break;
1404         case IP_TRANSPARENT:
1405                 val = inet->transparent;
1406                 break;
1407         case IP_MINTTL:
1408                 val = inet->min_ttl;
1409                 break;
1410         default:
1411                 release_sock(sk);
1412                 return -ENOPROTOOPT;
1413         }
1414         release_sock(sk);
1415
1416         if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1417                 unsigned char ucval = (unsigned char)val;
1418                 len = 1;
1419                 if (put_user(len, optlen))
1420                         return -EFAULT;
1421                 if (copy_to_user(optval, &ucval, 1))
1422                         return -EFAULT;
1423         } else {
1424                 len = min_t(unsigned int, sizeof(int), len);
1425                 if (put_user(len, optlen))
1426                         return -EFAULT;
1427                 if (copy_to_user(optval, &val, len))
1428                         return -EFAULT;
1429         }
1430         return 0;
1431 }
1432
1433 int ip_getsockopt(struct sock *sk, int level,
1434                   int optname, char __user *optval, int __user *optlen)
1435 {
1436         int err;
1437
1438         err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1439 #ifdef CONFIG_NETFILTER
1440         /* we need to exclude all possible ENOPROTOOPTs except default case */
1441         if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1442                         !ip_mroute_opt(optname)) {
1443                 int len;
1444
1445                 if (get_user(len, optlen))
1446                         return -EFAULT;
1447
1448                 lock_sock(sk);
1449                 err = nf_getsockopt(sk, PF_INET, optname, optval,
1450                                 &len);
1451                 release_sock(sk);
1452                 if (err >= 0)
1453                         err = put_user(len, optlen);
1454                 return err;
1455         }
1456 #endif
1457         return err;
1458 }
1459 EXPORT_SYMBOL(ip_getsockopt);
1460
1461 #ifdef CONFIG_COMPAT
1462 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1463                          char __user *optval, int __user *optlen)
1464 {
1465         int err;
1466
1467         if (optname == MCAST_MSFILTER)
1468                 return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1469                         ip_getsockopt);
1470
1471         err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1472                 MSG_CMSG_COMPAT);
1473
1474 #ifdef CONFIG_NETFILTER
1475         /* we need to exclude all possible ENOPROTOOPTs except default case */
1476         if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1477                         !ip_mroute_opt(optname)) {
1478                 int len;
1479
1480                 if (get_user(len, optlen))
1481                         return -EFAULT;
1482
1483                 lock_sock(sk);
1484                 err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1485                 release_sock(sk);
1486                 if (err >= 0)
1487                         err = put_user(len, optlen);
1488                 return err;
1489         }
1490 #endif
1491         return err;
1492 }
1493 EXPORT_SYMBOL(compat_ip_getsockopt);
1494 #endif