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
 253                         /* Our caller is responsible for freeing ipc->opt */
 254                         err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
 255                                              err < 40 ? err : 40);
 256                         if (err)
 257                                 return err;
 258                         break;
 259                 case IP_PKTINFO:
 260                 {
 261                         struct in_pktinfo *info;
 262                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
 263                                 return -EINVAL;
 264                         info = (struct in_pktinfo *)CMSG_DATA(cmsg);
 265                         ipc->oif = info->ipi_ifindex;
 266                         ipc->addr = info->ipi_spec_dst.s_addr;
 267                         break;
 268                 }
 269                 case IP_TTL:
 270                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 271                                 return -EINVAL;
 272                         val = *(int *)CMSG_DATA(cmsg);
 273                         if (val < 1 || val > 255)
 274                                 return -EINVAL;
 275                         ipc->ttl = val;
 276                         break;
 277                 case IP_TOS:
 278                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 279                                 return -EINVAL;
 280                         val = *(int *)CMSG_DATA(cmsg);
 281                         if (val < 0 || val > 255)
 282                                 return -EINVAL;
 283                         ipc->tos = val;
 284                         ipc->priority = rt_tos2priority(ipc->tos);
 285                         break;
 286
 287                 default:
 288                         return -EINVAL;
 289                 }
 290         }
 291         return 0;
 292 }
 293
 294
 295 /* Special input handler for packets caught by router alert option.
 296    They are selected only by protocol field, and then processed likely
 297    local ones; but only if someone wants them! Otherwise, router
 298    not running rsvpd will kill RSVP.
 299
 300    It is user level problem, what it will make with them.
 301    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
 302    but receiver should be enough clever f.e. to forward mtrace requests,
 303    sent to multicast group to reach destination designated router.
 304  */
 305 struct ip_ra_chain __rcu *ip_ra_chain;
 306 static DEFINE_SPINLOCK(ip_ra_lock);
 307
 308
 309 static void ip_ra_destroy_rcu(struct rcu_head *head)
 310 {
 311         struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
 312
 313         sock_put(ra->saved_sk);
 314         kfree(ra);
 315 }
 316
 317 int ip_ra_control(struct sock *sk, unsigned char on,
 318                   void (*destructor)(struct sock *))
 319 {
 320         struct ip_ra_chain *ra, *new_ra;
 321         struct ip_ra_chain __rcu **rap;
 322
 323         if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
 324                 return -EINVAL;
 325
 326         new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
 327
 328         spin_lock_bh(&ip_ra_lock);
 329         for (rap = &ip_ra_chain;
 330              (ra = rcu_dereference_protected(*rap,
 331                         lockdep_is_held(&ip_ra_lock))) != NULL;
 332              rap = &ra->next) {
 333                 if (ra->sk == sk) {
 334                         if (on) {
 335                                 spin_unlock_bh(&ip_ra_lock);
 336                                 kfree(new_ra);
 337                                 return -EADDRINUSE;
 338                         }
 339                         /* dont let ip_call_ra_chain() use sk again */
 340                         ra->sk = NULL;
 341                         RCU_INIT_POINTER(*rap, ra->next);
 342                         spin_unlock_bh(&ip_ra_lock);
 343
 344                         if (ra->destructor)
 345                                 ra->destructor(sk);
 346                         /*
 347                          * Delay sock_put(sk) and kfree(ra) after one rcu grace
 348                          * period. This guarantee ip_call_ra_chain() dont need
 349                          * to mess with socket refcounts.
 350                          */
 351                         ra->saved_sk = sk;
 352                         call_rcu(&ra->rcu, ip_ra_destroy_rcu);
 353                         return 0;
 354                 }
 355         }
 356         if (!new_ra) {
 357                 spin_unlock_bh(&ip_ra_lock);
 358                 return -ENOBUFS;
 359         }
 360         new_ra->sk = sk;
 361         new_ra->destructor = destructor;
 362
 363         RCU_INIT_POINTER(new_ra->next, ra);
 364         rcu_assign_pointer(*rap, new_ra);
 365         sock_hold(sk);
 366         spin_unlock_bh(&ip_ra_lock);
 367
 368         return 0;
 369 }
 370
 371 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 372                    __be16 port, u32 info, u8 *payload)
 373 {
 374         struct sock_exterr_skb *serr;
 375
 376         skb = skb_clone(skb, GFP_ATOMIC);
 377         if (!skb)
 378                 return;
 379
 380         serr = SKB_EXT_ERR(skb);
 381         serr->ee.ee_errno = err;
 382         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
 383         serr->ee.ee_type = icmp_hdr(skb)->type;
 384         serr->ee.ee_code = icmp_hdr(skb)->code;
 385         serr->ee.ee_pad = 0;
 386         serr->ee.ee_info = info;
 387         serr->ee.ee_data = 0;
 388         serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
 389                                    skb_network_header(skb);
 390         serr->port = port;
 391
 392         if (skb_pull(skb, payload - skb->data)) {
 393                 skb_reset_transport_header(skb);
 394                 if (sock_queue_err_skb(sk, skb) == 0)
 395                         return;
 396         }
 397         kfree_skb(skb);
 398 }
 399
 400 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
 401 {
 402         struct inet_sock *inet = inet_sk(sk);
 403         struct sock_exterr_skb *serr;
 404         struct iphdr *iph;
 405         struct sk_buff *skb;
 406
 407         if (!inet->recverr)
 408                 return;
 409
 410         skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
 411         if (!skb)
 412                 return;
 413
 414         skb_put(skb, sizeof(struct iphdr));
 415         skb_reset_network_header(skb);
 416         iph = ip_hdr(skb);
 417         iph->daddr = daddr;
 418
 419         serr = SKB_EXT_ERR(skb);
 420         serr->ee.ee_errno = err;
 421         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 422         serr->ee.ee_type = 0;
 423         serr->ee.ee_code = 0;
 424         serr->ee.ee_pad = 0;
 425         serr->ee.ee_info = info;
 426         serr->ee.ee_data = 0;
 427         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 428         serr->port = port;
 429
 430         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 431         skb_reset_transport_header(skb);
 432
 433         if (sock_queue_err_skb(sk, skb))
 434                 kfree_skb(skb);
 435 }
 436
 437 /* For some errors we have valid addr_offset even with zero payload and
 438  * zero port. Also, addr_offset should be supported if port is set.
 439  */
 440 static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
 441 {
 442         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 443                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 444 }
 445
 446 /* IPv4 supports cmsg on all imcp errors and some timestamps
 447  *
 448  * Timestamp code paths do not initialize the fields expected by cmsg:
 449  * the PKTINFO fields in skb->cb[]. Fill those in here.
 450  */
 451 static bool ipv4_datagram_support_cmsg(const struct sock *sk,
 452                                        struct sk_buff *skb,
 453                                        int ee_origin)
 454 {
 455         struct in_pktinfo *info;
 456
 457         if (ee_origin == SO_EE_ORIGIN_ICMP)
 458                 return true;
 459
 460         if (ee_origin == SO_EE_ORIGIN_LOCAL)
 461                 return false;
 462
 463         /* Support IP_PKTINFO on tstamp packets if requested, to correlate
 464          * timestamp with egress dev. Not possible for packets without dev
 465          * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
 466          */
 467         if ((!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG)) ||
 468             (!skb->dev))
 469                 return false;
 470
 471         info = PKTINFO_SKB_CB(skb);
 472         info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
 473         info->ipi_ifindex = skb->dev->ifindex;
 474         return true;
 475 }
 476
 477 /*
 478  *      Handle MSG_ERRQUEUE
 479  */
 480 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 481 {
 482         struct sock_exterr_skb *serr;
 483         struct sk_buff *skb;
 484         DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 485         struct {
 486                 struct sock_extended_err ee;
 487                 struct sockaddr_in       offender;
 488         } errhdr;
 489         int err;
 490         int copied;
 491
 492         WARN_ON_ONCE(sk->sk_family == AF_INET6);
 493
 494         err = -EAGAIN;
 495         skb = sock_dequeue_err_skb(sk);
 496         if (!skb)
 497                 goto out;
 498
 499         copied = skb->len;
 500         if (copied > len) {
 501                 msg->msg_flags |= MSG_TRUNC;
 502                 copied = len;
 503         }
 504         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 505         if (err)
 506                 goto out_free_skb;
 507
 508         sock_recv_timestamp(msg, sk, skb);
 509
 510         serr = SKB_EXT_ERR(skb);
 511
 512         if (sin && ipv4_datagram_support_addr(serr)) {
 513                 sin->sin_family = AF_INET;
 514                 sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
 515                                                    serr->addr_offset);
 516                 sin->sin_port = serr->port;
 517                 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
 518                 *addr_len = sizeof(*sin);
 519         }
 520
 521         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 522         sin = &errhdr.offender;
 523         memset(sin, 0, sizeof(*sin));
 524
 525         if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
 526                 sin->sin_family = AF_INET;
 527                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 528                 if (inet_sk(sk)->cmsg_flags)
 529                         ip_cmsg_recv(msg, skb);
 530         }
 531
 532         put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
 533
 534         /* Now we could try to dump offended packet options */
 535
 536         msg->msg_flags |= MSG_ERRQUEUE;
 537         err = copied;
 538
 539 out_free_skb:
 540         kfree_skb(skb);
 541 out:
 542         return err;
 543 }
 544
 545
 546 /*
 547  *      Socket option code for IP. This is the end of the line after any
 548  *      TCP,UDP etc options on an IP socket.
 549  */
 550 static bool setsockopt_needs_rtnl(int optname)
 551 {
 552         switch (optname) {
 553         case IP_ADD_MEMBERSHIP:
 554         case IP_ADD_SOURCE_MEMBERSHIP:
 555         case IP_BLOCK_SOURCE:
 556         case IP_DROP_MEMBERSHIP:
 557         case IP_DROP_SOURCE_MEMBERSHIP:
 558         case IP_MSFILTER:
 559         case IP_UNBLOCK_SOURCE:
 560         case MCAST_BLOCK_SOURCE:
 561         case MCAST_MSFILTER:
 562         case MCAST_JOIN_GROUP:
 563         case MCAST_JOIN_SOURCE_GROUP:
 564         case MCAST_LEAVE_GROUP:
 565         case MCAST_LEAVE_SOURCE_GROUP:
 566         case MCAST_UNBLOCK_SOURCE:
 567                 return true;
 568         }
 569         return false;
 570 }
 571
 572 static int do_ip_setsockopt(struct sock *sk, int level,
 573                             int optname, char __user *optval, unsigned int optlen)
 574 {
 575         struct inet_sock *inet = inet_sk(sk);
 576         int val = 0, err;
 577         bool needs_rtnl = setsockopt_needs_rtnl(optname);
 578
 579         switch (optname) {
 580         case IP_PKTINFO:
 581         case IP_RECVTTL:
 582         case IP_RECVOPTS:
 583         case IP_RECVTOS:
 584         case IP_RETOPTS:
 585         case IP_TOS:
 586         case IP_TTL:
 587         case IP_HDRINCL:
 588         case IP_MTU_DISCOVER:
 589         case IP_RECVERR:
 590         case IP_ROUTER_ALERT:
 591         case IP_FREEBIND:
 592         case IP_PASSSEC:
 593         case IP_TRANSPARENT:
 594         case IP_MINTTL:
 595         case IP_NODEFRAG:
 596         case IP_BIND_ADDRESS_NO_PORT:
 597         case IP_UNICAST_IF:
 598         case IP_MULTICAST_TTL:
 599         case IP_MULTICAST_ALL:
 600         case IP_MULTICAST_LOOP:
 601         case IP_RECVORIGDSTADDR:
 602         case IP_CHECKSUM:
 603                 if (optlen >= sizeof(int)) {
 604                         if (get_user(val, (int __user *) optval))
 605                                 return -EFAULT;
 606                 } else if (optlen >= sizeof(char)) {
 607                         unsigned char ucval;
 608
 609                         if (get_user(ucval, (unsigned char __user *) optval))
 610                                 return -EFAULT;
 611                         val = (int) ucval;
 612                 }
 613         }
 614
 615         /* If optlen==0, it is equivalent to val == 0 */
 616
 617         if (ip_mroute_opt(optname))
 618                 return ip_mroute_setsockopt(sk, optname, optval, optlen);
 619
 620         err = 0;
 621         if (needs_rtnl)
 622                 rtnl_lock();
 623         lock_sock(sk);
 624
 625         switch (optname) {
 626         case IP_OPTIONS:
 627         {
 628                 struct ip_options_rcu *old, *opt = NULL;
 629
 630                 if (optlen > 40)
 631                         goto e_inval;
 632                 err = ip_options_get_from_user(sock_net(sk), &opt,
 633                                                optval, optlen);
 634                 if (err)
 635                         break;
 636                 old = rcu_dereference_protected(inet->inet_opt,
 637                                                 sock_owned_by_user(sk));
 638                 if (inet->is_icsk) {
 639                         struct inet_connection_sock *icsk = inet_csk(sk);
 640 #if IS_ENABLED(CONFIG_IPV6)
 641                         if (sk->sk_family == PF_INET ||
 642                             (!((1 << sk->sk_state) &
 643                                (TCPF_LISTEN | TCPF_CLOSE)) &&
 644                              inet->inet_daddr != LOOPBACK4_IPV6)) {
 645 #endif
 646                                 if (old)
 647                                         icsk->icsk_ext_hdr_len -= old->opt.optlen;
 648                                 if (opt)
 649                                         icsk->icsk_ext_hdr_len += opt->opt.optlen;
 650                                 icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
 651 #if IS_ENABLED(CONFIG_IPV6)
 652                         }
 653 #endif
 654                 }
 655                 rcu_assign_pointer(inet->inet_opt, opt);
 656                 if (old)
 657                         kfree_rcu(old, rcu);
 658                 break;
 659         }
 660         case IP_PKTINFO:
 661                 if (val)
 662                         inet->cmsg_flags |= IP_CMSG_PKTINFO;
 663                 else
 664                         inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
 665                 break;
 666         case IP_RECVTTL:
 667                 if (val)
 668                         inet->cmsg_flags |=  IP_CMSG_TTL;
 669                 else
 670                         inet->cmsg_flags &= ~IP_CMSG_TTL;
 671                 break;
 672         case IP_RECVTOS:
 673                 if (val)
 674                         inet->cmsg_flags |=  IP_CMSG_TOS;
 675                 else
 676                         inet->cmsg_flags &= ~IP_CMSG_TOS;
 677                 break;
 678         case IP_RECVOPTS:
 679                 if (val)
 680                         inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
 681                 else
 682                         inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
 683                 break;
 684         case IP_RETOPTS:
 685                 if (val)
 686                         inet->cmsg_flags |= IP_CMSG_RETOPTS;
 687                 else
 688                         inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
 689                 break;
 690         case IP_PASSSEC:
 691                 if (val)
 692                         inet->cmsg_flags |= IP_CMSG_PASSSEC;
 693                 else
 694                         inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
 695                 break;
 696         case IP_RECVORIGDSTADDR:
 697                 if (val)
 698                         inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
 699                 else
 700                         inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
 701                 break;
 702         case IP_CHECKSUM:
 703                 if (val) {
 704                         if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
 705                                 inet_inc_convert_csum(sk);
 706                                 inet->cmsg_flags |= IP_CMSG_CHECKSUM;
 707                         }
 708                 } else {
 709                         if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
 710                                 inet_dec_convert_csum(sk);
 711                                 inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
 712                         }
 713                 }
 714                 break;
 715         case IP_TOS:    /* This sets both TOS and Precedence */
 716                 if (sk->sk_type == SOCK_STREAM) {
 717                         val &= ~INET_ECN_MASK;
 718                         val |= inet->tos & INET_ECN_MASK;
 719                 }
 720                 if (inet->tos != val) {
 721                         inet->tos = val;
 722                         sk->sk_priority = rt_tos2priority(val);
 723                         sk_dst_reset(sk);
 724                 }
 725                 break;
 726         case IP_TTL:
 727                 if (optlen < 1)
 728                         goto e_inval;
 729                 if (val != -1 && (val < 1 || val > 255))
 730                         goto e_inval;
 731                 inet->uc_ttl = val;
 732                 break;
 733         case IP_HDRINCL:
 734                 if (sk->sk_type != SOCK_RAW) {
 735                         err = -ENOPROTOOPT;
 736                         break;
 737                 }
 738                 inet->hdrincl = val ? 1 : 0;
 739                 break;
 740         case IP_NODEFRAG:
 741                 if (sk->sk_type != SOCK_RAW) {
 742                         err = -ENOPROTOOPT;
 743                         break;
 744                 }
 745                 inet->nodefrag = val ? 1 : 0;
 746                 break;
 747         case IP_BIND_ADDRESS_NO_PORT:
 748                 inet->bind_address_no_port = val ? 1 : 0;
 749                 break;
 750         case IP_MTU_DISCOVER:
 751                 if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
 752                         goto e_inval;
 753                 inet->pmtudisc = val;
 754                 break;
 755         case IP_RECVERR:
 756                 inet->recverr = !!val;
 757                 if (!val)
 758                         skb_queue_purge(&sk->sk_error_queue);
 759                 break;
 760         case IP_MULTICAST_TTL:
 761                 if (sk->sk_type == SOCK_STREAM)
 762                         goto e_inval;
 763                 if (optlen < 1)
 764                         goto e_inval;
 765                 if (val == -1)
 766                         val = 1;
 767                 if (val < 0 || val > 255)
 768                         goto e_inval;
 769                 inet->mc_ttl = val;
 770                 break;
 771         case IP_MULTICAST_LOOP:
 772                 if (optlen < 1)
 773                         goto e_inval;
 774                 inet->mc_loop = !!val;
 775                 break;
 776         case IP_UNICAST_IF:
 777         {
 778                 struct net_device *dev = NULL;
 779                 int ifindex;
 780
 781                 if (optlen != sizeof(int))
 782                         goto e_inval;
 783
 784                 ifindex = (__force int)ntohl((__force __be32)val);
 785                 if (ifindex == 0) {
 786                         inet->uc_index = 0;
 787                         err = 0;
 788                         break;
 789                 }
 790
 791                 dev = dev_get_by_index(sock_net(sk), ifindex);
 792                 err = -EADDRNOTAVAIL;
 793                 if (!dev)
 794                         break;
 795                 dev_put(dev);
 796
 797                 err = -EINVAL;
 798                 if (sk->sk_bound_dev_if)
 799                         break;
 800
 801                 inet->uc_index = ifindex;
 802                 err = 0;
 803                 break;
 804         }
 805         case IP_MULTICAST_IF:
 806         {
 807                 struct ip_mreqn mreq;
 808                 struct net_device *dev = NULL;
 809
 810                 if (sk->sk_type == SOCK_STREAM)
 811                         goto e_inval;
 812                 /*
 813                  *      Check the arguments are allowable
 814                  */
 815
 816                 if (optlen < sizeof(struct in_addr))
 817                         goto e_inval;
 818
 819                 err = -EFAULT;
 820                 if (optlen >= sizeof(struct ip_mreqn)) {
 821                         if (copy_from_user(&mreq, optval, sizeof(mreq)))
 822                                 break;
 823                 } else {
 824                         memset(&mreq, 0, sizeof(mreq));
 825                         if (optlen >= sizeof(struct ip_mreq)) {
 826                                 if (copy_from_user(&mreq, optval,
 827                                                    sizeof(struct ip_mreq)))
 828                                         break;
 829                         } else if (optlen >= sizeof(struct in_addr)) {
 830                                 if (copy_from_user(&mreq.imr_address, optval,
 831                                                    sizeof(struct in_addr)))
 832                                         break;
 833                         }
 834                 }
 835
 836                 if (!mreq.imr_ifindex) {
 837                         if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
 838                                 inet->mc_index = 0;
 839                                 inet->mc_addr  = 0;
 840                                 err = 0;
 841                                 break;
 842                         }
 843                         dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
 844                         if (dev)
 845                                 mreq.imr_ifindex = dev->ifindex;
 846                 } else
 847                         dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
 848
 849
 850                 err = -EADDRNOTAVAIL;
 851                 if (!dev)
 852                         break;
 853                 dev_put(dev);
 854
 855                 err = -EINVAL;
 856                 if (sk->sk_bound_dev_if &&
 857                     mreq.imr_ifindex != sk->sk_bound_dev_if)
 858                         break;
 859
 860                 inet->mc_index = mreq.imr_ifindex;
 861                 inet->mc_addr  = mreq.imr_address.s_addr;
 862                 err = 0;
 863                 break;
 864         }
 865
 866         case IP_ADD_MEMBERSHIP:
 867         case IP_DROP_MEMBERSHIP:
 868         {
 869                 struct ip_mreqn mreq;
 870
 871                 err = -EPROTO;
 872                 if (inet_sk(sk)->is_icsk)
 873                         break;
 874
 875                 if (optlen < sizeof(struct ip_mreq))
 876                         goto e_inval;
 877                 err = -EFAULT;
 878                 if (optlen >= sizeof(struct ip_mreqn)) {
 879                         if (copy_from_user(&mreq, optval, sizeof(mreq)))
 880                                 break;
 881                 } else {
 882                         memset(&mreq, 0, sizeof(mreq));
 883                         if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
 884                                 break;
 885                 }
 886
 887                 if (optname == IP_ADD_MEMBERSHIP)
 888                         err = ip_mc_join_group(sk, &mreq);
 889                 else
 890                         err = ip_mc_leave_group(sk, &mreq);
 891                 break;
 892         }
 893         case IP_MSFILTER:
 894         {
 895                 struct ip_msfilter *msf;
 896
 897                 if (optlen < IP_MSFILTER_SIZE(0))
 898                         goto e_inval;
 899                 if (optlen > sysctl_optmem_max) {
 900                         err = -ENOBUFS;
 901                         break;
 902                 }
 903                 msf = kmalloc(optlen, GFP_KERNEL);
 904                 if (!msf) {
 905                         err = -ENOBUFS;
 906                         break;
 907                 }
 908                 err = -EFAULT;
 909                 if (copy_from_user(msf, optval, optlen)) {
 910                         kfree(msf);
 911                         break;
 912                 }
 913                 /* numsrc >= (1G-4) overflow in 32 bits */
 914                 if (msf->imsf_numsrc >= 0x3ffffffcU ||
 915                     msf->imsf_numsrc > sysctl_igmp_max_msf) {
 916                         kfree(msf);
 917                         err = -ENOBUFS;
 918                         break;
 919                 }
 920                 if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
 921                         kfree(msf);
 922                         err = -EINVAL;
 923                         break;
 924                 }
 925                 err = ip_mc_msfilter(sk, msf, 0);
 926                 kfree(msf);
 927                 break;
 928         }
 929         case IP_BLOCK_SOURCE:
 930         case IP_UNBLOCK_SOURCE:
 931         case IP_ADD_SOURCE_MEMBERSHIP:
 932         case IP_DROP_SOURCE_MEMBERSHIP:
 933         {
 934                 struct ip_mreq_source mreqs;
 935                 int omode, add;
 936
 937                 if (optlen != sizeof(struct ip_mreq_source))
 938                         goto e_inval;
 939                 if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
 940                         err = -EFAULT;
 941                         break;
 942                 }
 943                 if (optname == IP_BLOCK_SOURCE) {
 944                         omode = MCAST_EXCLUDE;
 945                         add = 1;
 946                 } else if (optname == IP_UNBLOCK_SOURCE) {
 947                         omode = MCAST_EXCLUDE;
 948                         add = 0;
 949                 } else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
 950                         struct ip_mreqn mreq;
 951
 952                         mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
 953                         mreq.imr_address.s_addr = mreqs.imr_interface;
 954                         mreq.imr_ifindex = 0;
 955                         err = ip_mc_join_group(sk, &mreq);
 956                         if (err && err != -EADDRINUSE)
 957                                 break;
 958                         omode = MCAST_INCLUDE;
 959                         add = 1;
 960                 } else /* IP_DROP_SOURCE_MEMBERSHIP */ {
 961                         omode = MCAST_INCLUDE;
 962                         add = 0;
 963                 }
 964                 err = ip_mc_source(add, omode, sk, &mreqs, 0);
 965                 break;
 966         }
 967         case MCAST_JOIN_GROUP:
 968         case MCAST_LEAVE_GROUP:
 969         {
 970                 struct group_req greq;
 971                 struct sockaddr_in *psin;
 972                 struct ip_mreqn mreq;
 973
 974                 if (optlen < sizeof(struct group_req))
 975                         goto e_inval;
 976                 err = -EFAULT;
 977                 if (copy_from_user(&greq, optval, sizeof(greq)))
 978                         break;
 979                 psin = (struct sockaddr_in *)&greq.gr_group;
 980                 if (psin->sin_family != AF_INET)
 981                         goto e_inval;
 982                 memset(&mreq, 0, sizeof(mreq));
 983                 mreq.imr_multiaddr = psin->sin_addr;
 984                 mreq.imr_ifindex = greq.gr_interface;
 985
 986                 if (optname == MCAST_JOIN_GROUP)
 987                         err = ip_mc_join_group(sk, &mreq);
 988                 else
 989                         err = ip_mc_leave_group(sk, &mreq);
 990                 break;
 991         }
 992         case MCAST_JOIN_SOURCE_GROUP:
 993         case MCAST_LEAVE_SOURCE_GROUP:
 994         case MCAST_BLOCK_SOURCE:
 995         case MCAST_UNBLOCK_SOURCE:
 996         {
 997                 struct group_source_req greqs;
 998                 struct ip_mreq_source mreqs;
 999                 struct sockaddr_in *psin;
1000                 int omode, add;
1001
1002                 if (optlen != sizeof(struct group_source_req))
1003                         goto e_inval;
1004                 if (copy_from_user(&greqs, optval, sizeof(greqs))) {
1005                         err = -EFAULT;
1006                         break;
1007                 }
1008                 if (greqs.gsr_group.ss_family != AF_INET ||
1009                     greqs.gsr_source.ss_family != AF_INET) {
1010                         err = -EADDRNOTAVAIL;
1011                         break;
1012                 }
1013                 psin = (struct sockaddr_in *)&greqs.gsr_group;
1014                 mreqs.imr_multiaddr = psin->sin_addr.s_addr;
1015                 psin = (struct sockaddr_in *)&greqs.gsr_source;
1016                 mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
1017                 mreqs.imr_interface = 0; /* use index for mc_source */
1018
1019                 if (optname == MCAST_BLOCK_SOURCE) {
1020                         omode = MCAST_EXCLUDE;
1021                         add = 1;
1022                 } else if (optname == MCAST_UNBLOCK_SOURCE) {
1023                         omode = MCAST_EXCLUDE;
1024                         add = 0;
1025                 } else if (optname == MCAST_JOIN_SOURCE_GROUP) {
1026                         struct ip_mreqn mreq;
1027
1028                         psin = (struct sockaddr_in *)&greqs.gsr_group;
1029                         mreq.imr_multiaddr = psin->sin_addr;
1030                         mreq.imr_address.s_addr = 0;
1031                         mreq.imr_ifindex = greqs.gsr_interface;
1032                         err = ip_mc_join_group(sk, &mreq);
1033                         if (err && err != -EADDRINUSE)
1034                                 break;
1035                         greqs.gsr_interface = mreq.imr_ifindex;
1036                         omode = MCAST_INCLUDE;
1037                         add = 1;
1038                 } else /* MCAST_LEAVE_SOURCE_GROUP */ {
1039                         omode = MCAST_INCLUDE;
1040                         add = 0;
1041                 }
1042                 err = ip_mc_source(add, omode, sk, &mreqs,
1043                                    greqs.gsr_interface);
1044                 break;
1045         }
1046         case MCAST_MSFILTER:
1047         {
1048                 struct sockaddr_in *psin;
1049                 struct ip_msfilter *msf = NULL;
1050                 struct group_filter *gsf = NULL;
1051                 int msize, i, ifindex;
1052
1053                 if (optlen < GROUP_FILTER_SIZE(0))
1054                         goto e_inval;
1055                 if (optlen > sysctl_optmem_max) {
1056                         err = -ENOBUFS;
1057                         break;
1058                 }
1059                 gsf = kmalloc(optlen, GFP_KERNEL);
1060                 if (!gsf) {
1061                         err = -ENOBUFS;
1062                         break;
1063                 }
1064                 err = -EFAULT;
1065                 if (copy_from_user(gsf, optval, optlen))
1066                         goto mc_msf_out;
1067
1068                 /* numsrc >= (4G-140)/128 overflow in 32 bits */
1069                 if (gsf->gf_numsrc >= 0x1ffffff ||
1070                     gsf->gf_numsrc > sysctl_igmp_max_msf) {
1071                         err = -ENOBUFS;
1072                         goto mc_msf_out;
1073                 }
1074                 if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
1075                         err = -EINVAL;
1076                         goto mc_msf_out;
1077                 }
1078                 msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
1079                 msf = kmalloc(msize, GFP_KERNEL);
1080                 if (!msf) {
1081                         err = -ENOBUFS;
1082                         goto mc_msf_out;
1083                 }
1084                 ifindex = gsf->gf_interface;
1085                 psin = (struct sockaddr_in *)&gsf->gf_group;
1086                 if (psin->sin_family != AF_INET) {
1087                         err = -EADDRNOTAVAIL;
1088                         goto mc_msf_out;
1089                 }
1090                 msf->imsf_multiaddr = psin->sin_addr.s_addr;
1091                 msf->imsf_interface = 0;
1092                 msf->imsf_fmode = gsf->gf_fmode;
1093                 msf->imsf_numsrc = gsf->gf_numsrc;
1094                 err = -EADDRNOTAVAIL;
1095                 for (i = 0; i < gsf->gf_numsrc; ++i) {
1096                         psin = (struct sockaddr_in *)&gsf->gf_slist[i];
1097
1098                         if (psin->sin_family != AF_INET)
1099                                 goto mc_msf_out;
1100                         msf->imsf_slist[i] = psin->sin_addr.s_addr;
1101                 }
1102                 kfree(gsf);
1103                 gsf = NULL;
1104
1105                 err = ip_mc_msfilter(sk, msf, ifindex);
1106 mc_msf_out:
1107                 kfree(msf);
1108                 kfree(gsf);
1109                 break;
1110         }
1111         case IP_MULTICAST_ALL:
1112                 if (optlen < 1)
1113                         goto e_inval;
1114                 if (val != 0 && val != 1)
1115                         goto e_inval;
1116                 inet->mc_all = val;
1117                 break;
1118         case IP_ROUTER_ALERT:
1119                 err = ip_ra_control(sk, val ? 1 : 0, NULL);
1120                 break;
1121
1122         case IP_FREEBIND:
1123                 if (optlen < 1)
1124                         goto e_inval;
1125                 inet->freebind = !!val;
1126                 break;
1127
1128         case IP_IPSEC_POLICY:
1129         case IP_XFRM_POLICY:
1130                 err = -EPERM;
1131                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1132                         break;
1133                 err = xfrm_user_policy(sk, optname, optval, optlen);
1134                 break;
1135
1136         case IP_TRANSPARENT:
1137                 if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1138                     !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1139                         err = -EPERM;
1140                         break;
1141                 }
1142                 if (optlen < 1)
1143                         goto e_inval;
1144                 inet->transparent = !!val;
1145                 break;
1146
1147         case IP_MINTTL:
1148                 if (optlen < 1)
1149                         goto e_inval;
1150                 if (val < 0 || val > 255)
1151                         goto e_inval;
1152                 inet->min_ttl = val;
1153                 break;
1154
1155         default:
1156                 err = -ENOPROTOOPT;
1157                 break;
1158         }
1159         release_sock(sk);
1160         if (needs_rtnl)
1161                 rtnl_unlock();
1162         return err;
1163
1164 e_inval:
1165         release_sock(sk);
1166         if (needs_rtnl)
1167                 rtnl_unlock();
1168         return -EINVAL;
1169 }
1170
1171 /**
1172  * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1173  * @sk: socket
1174  * @skb: buffer
1175  *
1176  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1177  * destination in skb->cb[] before dst drop.
1178  * This way, receiver doesn't make cache line misses to read rtable.
1179  */
1180 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1181 {
1182         struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1183         bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1184                        ipv6_sk_rxinfo(sk);
1185
1186         if (prepare && skb_rtable(skb)) {
1187                 pktinfo->ipi_ifindex = inet_iif(skb);
1188                 pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1189         } else {
1190                 pktinfo->ipi_ifindex = 0;
1191                 pktinfo->ipi_spec_dst.s_addr = 0;
1192         }
1193         skb_dst_drop(skb);
1194 }
1195
1196 int ip_setsockopt(struct sock *sk, int level,
1197                 int optname, char __user *optval, unsigned int optlen)
1198 {
1199         int err;
1200
1201         if (level != SOL_IP)
1202                 return -ENOPROTOOPT;
1203
1204         err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1205 #ifdef CONFIG_NETFILTER
1206         /* we need to exclude all possible ENOPROTOOPTs except default case */
1207         if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1208                         optname != IP_IPSEC_POLICY &&
1209                         optname != IP_XFRM_POLICY &&
1210                         !ip_mroute_opt(optname)) {
1211                 lock_sock(sk);
1212                 err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1213                 release_sock(sk);
1214         }
1215 #endif
1216         return err;
1217 }
1218 EXPORT_SYMBOL(ip_setsockopt);
1219
1220 #ifdef CONFIG_COMPAT
1221 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1222                          char __user *optval, unsigned int optlen)
1223 {
1224         int err;
1225
1226         if (level != SOL_IP)
1227                 return -ENOPROTOOPT;
1228
1229         if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1230                 return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1231                         ip_setsockopt);
1232
1233         err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1234 #ifdef CONFIG_NETFILTER
1235         /* we need to exclude all possible ENOPROTOOPTs except default case */
1236         if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1237                         optname != IP_IPSEC_POLICY &&
1238                         optname != IP_XFRM_POLICY &&
1239                         !ip_mroute_opt(optname)) {
1240                 lock_sock(sk);
1241                 err = compat_nf_setsockopt(sk, PF_INET, optname,
1242                                            optval, optlen);
1243                 release_sock(sk);
1244         }
1245 #endif
1246         return err;
1247 }
1248 EXPORT_SYMBOL(compat_ip_setsockopt);
1249 #endif
1250
1251 /*
1252  *      Get the options. Note for future reference. The GET of IP options gets
1253  *      the _received_ ones. The set sets the _sent_ ones.
1254  */
1255
1256 static bool getsockopt_needs_rtnl(int optname)
1257 {
1258         switch (optname) {
1259         case IP_MSFILTER:
1260         case MCAST_MSFILTER:
1261                 return true;
1262         }
1263         return false;
1264 }
1265
1266 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1267                             char __user *optval, int __user *optlen, unsigned int flags)
1268 {
1269         struct inet_sock *inet = inet_sk(sk);
1270         bool needs_rtnl = getsockopt_needs_rtnl(optname);
1271         int val, err = 0;
1272         int len;
1273
1274         if (level != SOL_IP)
1275                 return -EOPNOTSUPP;
1276
1277         if (ip_mroute_opt(optname))
1278                 return ip_mroute_getsockopt(sk, optname, optval, optlen);
1279
1280         if (get_user(len, optlen))
1281                 return -EFAULT;
1282         if (len < 0)
1283                 return -EINVAL;
1284
1285         if (needs_rtnl)
1286                 rtnl_lock();
1287         lock_sock(sk);
1288
1289         switch (optname) {
1290         case IP_OPTIONS:
1291         {
1292                 unsigned char optbuf[sizeof(struct ip_options)+40];
1293                 struct ip_options *opt = (struct ip_options *)optbuf;
1294                 struct ip_options_rcu *inet_opt;
1295
1296                 inet_opt = rcu_dereference_protected(inet->inet_opt,
1297                                                      sock_owned_by_user(sk));
1298                 opt->optlen = 0;
1299                 if (inet_opt)
1300                         memcpy(optbuf, &inet_opt->opt,
1301                                sizeof(struct ip_options) +
1302                                inet_opt->opt.optlen);
1303                 release_sock(sk);
1304
1305                 if (opt->optlen == 0)
1306                         return put_user(0, optlen);
1307
1308                 ip_options_undo(opt);
1309
1310                 len = min_t(unsigned int, len, opt->optlen);
1311                 if (put_user(len, optlen))
1312                         return -EFAULT;
1313                 if (copy_to_user(optval, opt->__data, len))
1314                         return -EFAULT;
1315                 return 0;
1316         }
1317         case IP_PKTINFO:
1318                 val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1319                 break;
1320         case IP_RECVTTL:
1321                 val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1322                 break;
1323         case IP_RECVTOS:
1324                 val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1325                 break;
1326         case IP_RECVOPTS:
1327                 val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1328                 break;
1329         case IP_RETOPTS:
1330                 val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1331                 break;
1332         case IP_PASSSEC:
1333                 val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1334                 break;
1335         case IP_RECVORIGDSTADDR:
1336                 val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1337                 break;
1338         case IP_CHECKSUM:
1339                 val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1340                 break;
1341         case IP_TOS:
1342                 val = inet->tos;
1343                 break;
1344         case IP_TTL:
1345                 val = (inet->uc_ttl == -1 ?
1346                        sysctl_ip_default_ttl :
1347                        inet->uc_ttl);
1348                 break;
1349         case IP_HDRINCL:
1350                 val = inet->hdrincl;
1351                 break;
1352         case IP_NODEFRAG:
1353                 val = inet->nodefrag;
1354                 break;
1355         case IP_BIND_ADDRESS_NO_PORT:
1356                 val = inet->bind_address_no_port;
1357                 break;
1358         case IP_MTU_DISCOVER:
1359                 val = inet->pmtudisc;
1360                 break;
1361         case IP_MTU:
1362         {
1363                 struct dst_entry *dst;
1364                 val = 0;
1365                 dst = sk_dst_get(sk);
1366                 if (dst) {
1367                         val = dst_mtu(dst);
1368                         dst_release(dst);
1369                 }
1370                 if (!val) {
1371                         release_sock(sk);
1372                         return -ENOTCONN;
1373                 }
1374                 break;
1375         }
1376         case IP_RECVERR:
1377                 val = inet->recverr;
1378                 break;
1379         case IP_MULTICAST_TTL:
1380                 val = inet->mc_ttl;
1381                 break;
1382         case IP_MULTICAST_LOOP:
1383                 val = inet->mc_loop;
1384                 break;
1385         case IP_UNICAST_IF:
1386                 val = (__force int)htonl((__u32) inet->uc_index);
1387                 break;
1388         case IP_MULTICAST_IF:
1389         {
1390                 struct in_addr addr;
1391                 len = min_t(unsigned int, len, sizeof(struct in_addr));
1392                 addr.s_addr = inet->mc_addr;
1393                 release_sock(sk);
1394
1395                 if (put_user(len, optlen))
1396                         return -EFAULT;
1397                 if (copy_to_user(optval, &addr, len))
1398                         return -EFAULT;
1399                 return 0;
1400         }
1401         case IP_MSFILTER:
1402         {
1403                 struct ip_msfilter msf;
1404
1405                 if (len < IP_MSFILTER_SIZE(0)) {
1406                         err = -EINVAL;
1407                         goto out;
1408                 }
1409                 if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1410                         err = -EFAULT;
1411                         goto out;
1412                 }
1413                 err = ip_mc_msfget(sk, &msf,
1414                                    (struct ip_msfilter __user *)optval, optlen);
1415                 goto out;
1416         }
1417         case MCAST_MSFILTER:
1418         {
1419                 struct group_filter gsf;
1420
1421                 if (len < GROUP_FILTER_SIZE(0)) {
1422                         err = -EINVAL;
1423                         goto out;
1424                 }
1425                 if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1426                         err = -EFAULT;
1427                         goto out;
1428                 }
1429                 err = ip_mc_gsfget(sk, &gsf,
1430                                    (struct group_filter __user *)optval,
1431                                    optlen);
1432                 goto out;
1433         }
1434         case IP_MULTICAST_ALL:
1435                 val = inet->mc_all;
1436                 break;
1437         case IP_PKTOPTIONS:
1438         {
1439                 struct msghdr msg;
1440
1441                 release_sock(sk);
1442
1443                 if (sk->sk_type != SOCK_STREAM)
1444                         return -ENOPROTOOPT;
1445
1446                 msg.msg_control = (__force void *) optval;
1447                 msg.msg_controllen = len;
1448                 msg.msg_flags = flags;
1449
1450                 if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1451                         struct in_pktinfo info;
1452
1453                         info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1454                         info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1455                         info.ipi_ifindex = inet->mc_index;
1456                         put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1457                 }
1458                 if (inet->cmsg_flags & IP_CMSG_TTL) {
1459                         int hlim = inet->mc_ttl;
1460                         put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1461                 }
1462                 if (inet->cmsg_flags & IP_CMSG_TOS) {
1463                         int tos = inet->rcv_tos;
1464                         put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1465                 }
1466                 len -= msg.msg_controllen;
1467                 return put_user(len, optlen);
1468         }
1469         case IP_FREEBIND:
1470                 val = inet->freebind;
1471                 break;
1472         case IP_TRANSPARENT:
1473                 val = inet->transparent;
1474                 break;
1475         case IP_MINTTL:
1476                 val = inet->min_ttl;
1477                 break;
1478         default:
1479                 release_sock(sk);
1480                 return -ENOPROTOOPT;
1481         }
1482         release_sock(sk);
1483
1484         if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1485                 unsigned char ucval = (unsigned char)val;
1486                 len = 1;
1487                 if (put_user(len, optlen))
1488                         return -EFAULT;
1489                 if (copy_to_user(optval, &ucval, 1))
1490                         return -EFAULT;
1491         } else {
1492                 len = min_t(unsigned int, sizeof(int), len);
1493                 if (put_user(len, optlen))
1494                         return -EFAULT;
1495                 if (copy_to_user(optval, &val, len))
1496                         return -EFAULT;
1497         }
1498         return 0;
1499
1500 out:
1501         release_sock(sk);
1502         if (needs_rtnl)
1503                 rtnl_unlock();
1504         return err;
1505 }
1506
1507 int ip_getsockopt(struct sock *sk, int level,
1508                   int optname, char __user *optval, int __user *optlen)
1509 {
1510         int err;
1511
1512         err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1513 #ifdef CONFIG_NETFILTER
1514         /* we need to exclude all possible ENOPROTOOPTs except default case */
1515         if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1516                         !ip_mroute_opt(optname)) {
1517                 int len;
1518
1519                 if (get_user(len, optlen))
1520                         return -EFAULT;
1521
1522                 lock_sock(sk);
1523                 err = nf_getsockopt(sk, PF_INET, optname, optval,
1524                                 &len);
1525                 release_sock(sk);
1526                 if (err >= 0)
1527                         err = put_user(len, optlen);
1528                 return err;
1529         }
1530 #endif
1531         return err;
1532 }
1533 EXPORT_SYMBOL(ip_getsockopt);
1534
1535 #ifdef CONFIG_COMPAT
1536 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1537                          char __user *optval, int __user *optlen)
1538 {
1539         int err;
1540
1541         if (optname == MCAST_MSFILTER)
1542                 return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1543                         ip_getsockopt);
1544
1545         err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1546                 MSG_CMSG_COMPAT);
1547
1548 #ifdef CONFIG_NETFILTER
1549         /* we need to exclude all possible ENOPROTOOPTs except default case */
1550         if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1551                         !ip_mroute_opt(optname)) {
1552                 int len;
1553
1554                 if (get_user(len, optlen))
1555                         return -EFAULT;
1556
1557                 lock_sock(sk);
1558                 err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1559                 release_sock(sk);
1560                 if (err >= 0)
1561                         err = put_user(len, optlen);
1562                 return err;
1563         }
1564 #endif
1565         return err;
1566 }
1567 EXPORT_SYMBOL(compat_ip_getsockopt);
1568 #endif