net/ipv4/route.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  *              ROUTE - implementation of the IP router.
   7  *
   8  * Authors:     Ross Biro
   9  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  10  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  11  *              Linus Torvalds, <Linus.Torvalds@helsinki.fi>
  12  *              Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  13  *
  14  * Fixes:
  15  *              Alan Cox        :       Verify area fixes.
  16  *              Alan Cox        :       cli() protects routing changes
  17  *              Rui Oliveira    :       ICMP routing table updates
  18  *              (rco@di.uminho.pt)      Routing table insertion and update
  19  *              Linus Torvalds  :       Rewrote bits to be sensible
  20  *              Alan Cox        :       Added BSD route gw semantics
  21  *              Alan Cox        :       Super /proc >4K
  22  *              Alan Cox        :       MTU in route table
  23  *              Alan Cox        :       MSS actually. Also added the window
  24  *                                      clamper.
  25  *              Sam Lantinga    :       Fixed route matching in rt_del()
  26  *              Alan Cox        :       Routing cache support.
  27  *              Alan Cox        :       Removed compatibility cruft.
  28  *              Alan Cox        :       RTF_REJECT support.
  29  *              Alan Cox        :       TCP irtt support.
  30  *              Jonathan Naylor :       Added Metric support.
  31  *      Miquel van Smoorenburg  :       BSD API fixes.
  32  *      Miquel van Smoorenburg  :       Metrics.
  33  *              Alan Cox        :       Use __u32 properly
  34  *              Alan Cox        :       Aligned routing errors more closely with BSD
  35  *                                      our system is still very different.
  36  *              Alan Cox        :       Faster /proc handling
  37  *      Alexey Kuznetsov        :       Massive rework to support tree based routing,
  38  *                                      routing caches and better behaviour.
  39  *
  40  *              Olaf Erb        :       irtt wasn't being copied right.
  41  *              Bjorn Ekwall    :       Kerneld route support.
  42  *              Alan Cox        :       Multicast fixed (I hope)
  43  *              Pavel Krauz     :       Limited broadcast fixed
  44  *              Mike McLagan    :       Routing by source
  45  *      Alexey Kuznetsov        :       End of old history. Split to fib.c and
  46  *                                      route.c and rewritten from scratch.
  47  *              Andi Kleen      :       Load-limit warning messages.
  48  *      Vitaly E. Lavrov        :       Transparent proxy revived after year coma.
  49  *      Vitaly E. Lavrov        :       Race condition in ip_route_input_slow.
  50  *      Tobias Ringstrom        :       Uninitialized res.type in ip_route_output_slow.
  51  *      Vladimir V. Ivanov      :       IP rule info (flowid) is really useful.
  52  *              Marc Boucher    :       routing by fwmark
  53  *      Robert Olsson           :       Added rt_cache statistics
  54  *      Arnaldo C. Melo         :       Convert proc stuff to seq_file
  55  *      Eric Dumazet            :       hashed spinlocks and rt_check_expire() fixes.
  56  *      Ilia Sotnikov           :       Ignore TOS on PMTUD and Redirect
  57  *      Ilia Sotnikov           :       Removed TOS from hash calculations
  58  *
  59  *              This program is free software; you can redistribute it and/or
  60  *              modify it under the terms of the GNU General Public License
  61  *              as published by the Free Software Foundation; either version
  62  *              2 of the License, or (at your option) any later version.
  63  */
  64
  65 #define pr_fmt(fmt) "IPv4: " fmt
  66
  67 #include <linux/module.h>
  68 #include <linux/uaccess.h>
  69 #include <linux/bitops.h>
  70 #include <linux/types.h>
  71 #include <linux/kernel.h>
  72 #include <linux/mm.h>
  73 #include <linux/string.h>
  74 #include <linux/socket.h>
  75 #include <linux/sockios.h>
  76 #include <linux/errno.h>
  77 #include <linux/in.h>
  78 #include <linux/inet.h>
  79 #include <linux/netdevice.h>
  80 #include <linux/proc_fs.h>
  81 #include <linux/init.h>
  82 #include <linux/skbuff.h>
  83 #include <linux/inetdevice.h>
  84 #include <linux/igmp.h>
  85 #include <linux/pkt_sched.h>
  86 #include <linux/mroute.h>
  87 #include <linux/netfilter_ipv4.h>
  88 #include <linux/random.h>
  89 #include <linux/rcupdate.h>
  90 #include <linux/times.h>
  91 #include <linux/slab.h>
  92 #include <linux/jhash.h>
  93 #include <net/dst.h>
  94 #include <net/dst_metadata.h>
  95 #include <net/net_namespace.h>
  96 #include <net/protocol.h>
  97 #include <net/ip.h>
  98 #include <net/route.h>
  99 #include <net/inetpeer.h>
 100 #include <net/sock.h>
 101 #include <net/ip_fib.h>
 102 #include <net/arp.h>
 103 #include <net/tcp.h>
 104 #include <net/icmp.h>
 105 #include <net/xfrm.h>
 106 #include <net/lwtunnel.h>
 107 #include <net/netevent.h>
 108 #include <net/rtnetlink.h>
 109 #ifdef CONFIG_SYSCTL
 110 #include <linux/sysctl.h>
 111 #include <linux/kmemleak.h>
 112 #endif
 113 #include <net/secure_seq.h>
 114 #include <net/ip_tunnels.h>
 115 #include <net/l3mdev.h>
 116
 117 #include "fib_lookup.h"
 118
 119 #define RT_FL_TOS(oldflp4) \
 120         ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
 121
 122 #define RT_GC_TIMEOUT (300*HZ)
 123
 124 static int ip_rt_max_size;
 125 static int ip_rt_redirect_number __read_mostly  = 9;
 126 static int ip_rt_redirect_load __read_mostly    = HZ / 50;
 127 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
 128 static int ip_rt_error_cost __read_mostly       = HZ;
 129 static int ip_rt_error_burst __read_mostly      = 5 * HZ;
 130 static int ip_rt_mtu_expires __read_mostly      = 10 * 60 * HZ;
 131 static u32 ip_rt_min_pmtu __read_mostly         = 512 + 20 + 20;
 132 static int ip_rt_min_advmss __read_mostly       = 256;
 133
 134 static int ip_rt_gc_timeout __read_mostly       = RT_GC_TIMEOUT;
 135
 136 /*
 137  *      Interface to generic destination cache.
 138  */
 139
 140 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
 141 static unsigned int      ipv4_default_advmss(const struct dst_entry *dst);
 142 static unsigned int      ipv4_mtu(const struct dst_entry *dst);
 143 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
 144 static void              ipv4_link_failure(struct sk_buff *skb);
 145 static void              ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
 146                                            struct sk_buff *skb, u32 mtu);
 147 static void              ip_do_redirect(struct dst_entry *dst, struct sock *sk,
 148                                         struct sk_buff *skb);
 149 static void             ipv4_dst_destroy(struct dst_entry *dst);
 150
 151 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
 152 {
 153         WARN_ON(1);
 154         return NULL;
 155 }
 156
 157 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
 158                                            struct sk_buff *skb,
 159                                            const void *daddr);
 160 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
 161
 162 static struct dst_ops ipv4_dst_ops = {
 163         .family =               AF_INET,
 164         .check =                ipv4_dst_check,
 165         .default_advmss =       ipv4_default_advmss,
 166         .mtu =                  ipv4_mtu,
 167         .cow_metrics =          ipv4_cow_metrics,
 168         .destroy =              ipv4_dst_destroy,
 169         .negative_advice =      ipv4_negative_advice,
 170         .link_failure =         ipv4_link_failure,
 171         .update_pmtu =          ip_rt_update_pmtu,
 172         .redirect =             ip_do_redirect,
 173         .local_out =            __ip_local_out,
 174         .neigh_lookup =         ipv4_neigh_lookup,
 175         .confirm_neigh =        ipv4_confirm_neigh,
 176 };
 177
 178 #define ECN_OR_COST(class)      TC_PRIO_##class
 179
 180 const __u8 ip_tos2prio[16] = {
 181         TC_PRIO_BESTEFFORT,
 182         ECN_OR_COST(BESTEFFORT),
 183         TC_PRIO_BESTEFFORT,
 184         ECN_OR_COST(BESTEFFORT),
 185         TC_PRIO_BULK,
 186         ECN_OR_COST(BULK),
 187         TC_PRIO_BULK,
 188         ECN_OR_COST(BULK),
 189         TC_PRIO_INTERACTIVE,
 190         ECN_OR_COST(INTERACTIVE),
 191         TC_PRIO_INTERACTIVE,
 192         ECN_OR_COST(INTERACTIVE),
 193         TC_PRIO_INTERACTIVE_BULK,
 194         ECN_OR_COST(INTERACTIVE_BULK),
 195         TC_PRIO_INTERACTIVE_BULK,
 196         ECN_OR_COST(INTERACTIVE_BULK)
 197 };
 198 EXPORT_SYMBOL(ip_tos2prio);
 199
 200 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
 201 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
 202
 203 #ifdef CONFIG_PROC_FS
 204 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
 205 {
 206         if (*pos)
 207                 return NULL;
 208         return SEQ_START_TOKEN;
 209 }
 210
 211 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 212 {
 213         ++*pos;
 214         return NULL;
 215 }
 216
 217 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
 218 {
 219 }
 220
 221 static int rt_cache_seq_show(struct seq_file *seq, void *v)
 222 {
 223         if (v == SEQ_START_TOKEN)
 224                 seq_printf(seq, "%-127s\n",
 225                            "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
 226                            "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
 227                            "HHUptod\tSpecDst");
 228         return 0;
 229 }
 230
 231 static const struct seq_operations rt_cache_seq_ops = {
 232         .start  = rt_cache_seq_start,
 233         .next   = rt_cache_seq_next,
 234         .stop   = rt_cache_seq_stop,
 235         .show   = rt_cache_seq_show,
 236 };
 237
 238 static int rt_cache_seq_open(struct inode *inode, struct file *file)
 239 {
 240         return seq_open(file, &rt_cache_seq_ops);
 241 }
 242
 243 static const struct file_operations rt_cache_seq_fops = {
 244         .open    = rt_cache_seq_open,
 245         .read    = seq_read,
 246         .llseek  = seq_lseek,
 247         .release = seq_release,
 248 };
 249
 250
 251 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
 252 {
 253         int cpu;
 254
 255         if (*pos == 0)
 256                 return SEQ_START_TOKEN;
 257
 258         for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
 259                 if (!cpu_possible(cpu))
 260                         continue;
 261                 *pos = cpu+1;
 262                 return &per_cpu(rt_cache_stat, cpu);
 263         }
 264         return NULL;
 265 }
 266
 267 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 268 {
 269         int cpu;
 270
 271         for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
 272                 if (!cpu_possible(cpu))
 273                         continue;
 274                 *pos = cpu+1;
 275                 return &per_cpu(rt_cache_stat, cpu);
 276         }
 277         return NULL;
 278
 279 }
 280
 281 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
 282 {
 283
 284 }
 285
 286 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
 287 {
 288         struct rt_cache_stat *st = v;
 289
 290         if (v == SEQ_START_TOKEN) {
 291                 seq_printf(seq, "entries  in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src  out_hit out_slow_tot out_slow_mc  gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
 292                 return 0;
 293         }
 294
 295         seq_printf(seq,"%08x  %08x %08x %08x %08x %08x %08x %08x "
 296                    " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
 297                    dst_entries_get_slow(&ipv4_dst_ops),
 298                    0, /* st->in_hit */
 299                    st->in_slow_tot,
 300                    st->in_slow_mc,
 301                    st->in_no_route,
 302                    st->in_brd,
 303                    st->in_martian_dst,
 304                    st->in_martian_src,
 305
 306                    0, /* st->out_hit */
 307                    st->out_slow_tot,
 308                    st->out_slow_mc,
 309
 310                    0, /* st->gc_total */
 311                    0, /* st->gc_ignored */
 312                    0, /* st->gc_goal_miss */
 313                    0, /* st->gc_dst_overflow */
 314                    0, /* st->in_hlist_search */
 315                    0  /* st->out_hlist_search */
 316                 );
 317         return 0;
 318 }
 319
 320 static const struct seq_operations rt_cpu_seq_ops = {
 321         .start  = rt_cpu_seq_start,
 322         .next   = rt_cpu_seq_next,
 323         .stop   = rt_cpu_seq_stop,
 324         .show   = rt_cpu_seq_show,
 325 };
 326
 327
 328 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
 329 {
 330         return seq_open(file, &rt_cpu_seq_ops);
 331 }
 332
 333 static const struct file_operations rt_cpu_seq_fops = {
 334         .open    = rt_cpu_seq_open,
 335         .read    = seq_read,
 336         .llseek  = seq_lseek,
 337         .release = seq_release,
 338 };
 339
 340 #ifdef CONFIG_IP_ROUTE_CLASSID
 341 static int rt_acct_proc_show(struct seq_file *m, void *v)
 342 {
 343         struct ip_rt_acct *dst, *src;
 344         unsigned int i, j;
 345
 346         dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
 347         if (!dst)
 348                 return -ENOMEM;
 349
 350         for_each_possible_cpu(i) {
 351                 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
 352                 for (j = 0; j < 256; j++) {
 353                         dst[j].o_bytes   += src[j].o_bytes;
 354                         dst[j].o_packets += src[j].o_packets;
 355                         dst[j].i_bytes   += src[j].i_bytes;
 356                         dst[j].i_packets += src[j].i_packets;
 357                 }
 358         }
 359
 360         seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
 361         kfree(dst);
 362         return 0;
 363 }
 364
 365 static int rt_acct_proc_open(struct inode *inode, struct file *file)
 366 {
 367         return single_open(file, rt_acct_proc_show, NULL);
 368 }
 369
 370 static const struct file_operations rt_acct_proc_fops = {
 371         .open           = rt_acct_proc_open,
 372         .read           = seq_read,
 373         .llseek         = seq_lseek,
 374         .release        = single_release,
 375 };
 376 #endif
 377
 378 static int __net_init ip_rt_do_proc_init(struct net *net)
 379 {
 380         struct proc_dir_entry *pde;
 381
 382         pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
 383                           &rt_cache_seq_fops);
 384         if (!pde)
 385                 goto err1;
 386
 387         pde = proc_create("rt_cache", S_IRUGO,
 388                           net->proc_net_stat, &rt_cpu_seq_fops);
 389         if (!pde)
 390                 goto err2;
 391
 392 #ifdef CONFIG_IP_ROUTE_CLASSID
 393         pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
 394         if (!pde)
 395                 goto err3;
 396 #endif
 397         return 0;
 398
 399 #ifdef CONFIG_IP_ROUTE_CLASSID
 400 err3:
 401         remove_proc_entry("rt_cache", net->proc_net_stat);
 402 #endif
 403 err2:
 404         remove_proc_entry("rt_cache", net->proc_net);
 405 err1:
 406         return -ENOMEM;
 407 }
 408
 409 static void __net_exit ip_rt_do_proc_exit(struct net *net)
 410 {
 411         remove_proc_entry("rt_cache", net->proc_net_stat);
 412         remove_proc_entry("rt_cache", net->proc_net);
 413 #ifdef CONFIG_IP_ROUTE_CLASSID
 414         remove_proc_entry("rt_acct", net->proc_net);
 415 #endif
 416 }
 417
 418 static struct pernet_operations ip_rt_proc_ops __net_initdata =  {
 419         .init = ip_rt_do_proc_init,
 420         .exit = ip_rt_do_proc_exit,
 421 };
 422
 423 static int __init ip_rt_proc_init(void)
 424 {
 425         return register_pernet_subsys(&ip_rt_proc_ops);
 426 }
 427
 428 #else
 429 static inline int ip_rt_proc_init(void)
 430 {
 431         return 0;
 432 }
 433 #endif /* CONFIG_PROC_FS */
 434
 435 static inline bool rt_is_expired(const struct rtable *rth)
 436 {
 437         return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
 438 }
 439
 440 void rt_cache_flush(struct net *net)
 441 {
 442         rt_genid_bump_ipv4(net);
 443 }
 444
 445 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
 446                                            struct sk_buff *skb,
 447                                            const void *daddr)
 448 {
 449         struct net_device *dev = dst->dev;
 450         const __be32 *pkey = daddr;
 451         const struct rtable *rt;
 452         struct neighbour *n;
 453
 454         rt = (const struct rtable *) dst;
 455         if (rt->rt_gateway)
 456                 pkey = (const __be32 *) &rt->rt_gateway;
 457         else if (skb)
 458                 pkey = &ip_hdr(skb)->daddr;
 459
 460         n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
 461         if (n)
 462                 return n;
 463         return neigh_create(&arp_tbl, pkey, dev);
 464 }
 465
 466 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
 467 {
 468         struct net_device *dev = dst->dev;
 469         const __be32 *pkey = daddr;
 470         const struct rtable *rt;
 471
 472         rt = (const struct rtable *)dst;
 473         if (rt->rt_gateway)
 474                 pkey = (const __be32 *)&rt->rt_gateway;
 475         else if (!daddr ||
 476                  (rt->rt_flags &
 477                   (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL)))
 478                 return;
 479
 480         __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
 481 }
 482
 483 #define IP_IDENTS_SZ 2048u
 484
 485 static atomic_t *ip_idents __read_mostly;
 486 static u32 *ip_tstamps __read_mostly;
 487
 488 /* In order to protect privacy, we add a perturbation to identifiers
 489  * if one generator is seldom used. This makes hard for an attacker
 490  * to infer how many packets were sent between two points in time.
 491  */
 492 u32 ip_idents_reserve(u32 hash, int segs)
 493 {
 494         u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
 495         atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
 496         u32 old = READ_ONCE(*p_tstamp);
 497         u32 now = (u32)jiffies;
 498         u32 new, delta = 0;
 499
 500         if (old != now && cmpxchg(p_tstamp, old, now) == old)
 501                 delta = prandom_u32_max(now - old);
 502
 503         /* Do not use atomic_add_return() as it makes UBSAN unhappy */
 504         do {
 505                 old = (u32)atomic_read(p_id);
 506                 new = old + delta + segs;
 507         } while (atomic_cmpxchg(p_id, old, new) != old);
 508
 509         return new - segs;
 510 }
 511 EXPORT_SYMBOL(ip_idents_reserve);
 512
 513 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
 514 {
 515         static u32 ip_idents_hashrnd __read_mostly;
 516         u32 hash, id;
 517
 518         net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
 519
 520         hash = jhash_3words((__force u32)iph->daddr,
 521                             (__force u32)iph->saddr,
 522                             iph->protocol ^ net_hash_mix(net),
 523                             ip_idents_hashrnd);
 524         id = ip_idents_reserve(hash, segs);
 525         iph->id = htons(id);
 526 }
 527 EXPORT_SYMBOL(__ip_select_ident);
 528
 529 static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
 530                              const struct sock *sk,
 531                              const struct iphdr *iph,
 532                              int oif, u8 tos,
 533                              u8 prot, u32 mark, int flow_flags)
 534 {
 535         if (sk) {
 536                 const struct inet_sock *inet = inet_sk(sk);
 537
 538                 oif = sk->sk_bound_dev_if;
 539                 mark = sk->sk_mark;
 540                 tos = RT_CONN_FLAGS(sk);
 541                 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
 542         }
 543         flowi4_init_output(fl4, oif, mark, tos,
 544                            RT_SCOPE_UNIVERSE, prot,
 545                            flow_flags,
 546                            iph->daddr, iph->saddr, 0, 0,
 547                            sock_net_uid(net, sk));
 548 }
 549
 550 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
 551                                const struct sock *sk)
 552 {
 553         const struct net *net = dev_net(skb->dev);
 554         const struct iphdr *iph = ip_hdr(skb);
 555         int oif = skb->dev->ifindex;
 556         u8 tos = RT_TOS(iph->tos);
 557         u8 prot = iph->protocol;
 558         u32 mark = skb->mark;
 559
 560         __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
 561 }
 562
 563 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
 564 {
 565         const struct inet_sock *inet = inet_sk(sk);
 566         const struct ip_options_rcu *inet_opt;
 567         __be32 daddr = inet->inet_daddr;
 568
 569         rcu_read_lock();
 570         inet_opt = rcu_dereference(inet->inet_opt);
 571         if (inet_opt && inet_opt->opt.srr)
 572                 daddr = inet_opt->opt.faddr;
 573         flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
 574                            RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
 575                            inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
 576                            inet_sk_flowi_flags(sk),
 577                            daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
 578         rcu_read_unlock();
 579 }
 580
 581 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
 582                                  const struct sk_buff *skb)
 583 {
 584         if (skb)
 585                 build_skb_flow_key(fl4, skb, sk);
 586         else
 587                 build_sk_flow_key(fl4, sk);
 588 }
 589
 590 static DEFINE_SPINLOCK(fnhe_lock);
 591
 592 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
 593 {
 594         struct rtable *rt;
 595
 596         rt = rcu_dereference(fnhe->fnhe_rth_input);
 597         if (rt) {
 598                 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
 599                 dst_dev_put(&rt->dst);
 600                 dst_release(&rt->dst);
 601         }
 602         rt = rcu_dereference(fnhe->fnhe_rth_output);
 603         if (rt) {
 604                 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
 605                 dst_dev_put(&rt->dst);
 606                 dst_release(&rt->dst);
 607         }
 608 }
 609
 610 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
 611 {
 612         struct fib_nh_exception *fnhe, *oldest;
 613
 614         oldest = rcu_dereference(hash->chain);
 615         for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
 616              fnhe = rcu_dereference(fnhe->fnhe_next)) {
 617                 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
 618                         oldest = fnhe;
 619         }
 620         fnhe_flush_routes(oldest);
 621         return oldest;
 622 }
 623
 624 static inline u32 fnhe_hashfun(__be32 daddr)
 625 {
 626         static u32 fnhe_hashrnd __read_mostly;
 627         u32 hval;
 628
 629         net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
 630         hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
 631         return hash_32(hval, FNHE_HASH_SHIFT);
 632 }
 633
 634 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
 635 {
 636         rt->rt_pmtu = fnhe->fnhe_pmtu;
 637         rt->dst.expires = fnhe->fnhe_expires;
 638
 639         if (fnhe->fnhe_gw) {
 640                 rt->rt_flags |= RTCF_REDIRECTED;
 641                 rt->rt_gateway = fnhe->fnhe_gw;
 642                 rt->rt_uses_gateway = 1;
 643         }
 644 }
 645
 646 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
 647                                   u32 pmtu, unsigned long expires)
 648 {
 649         struct fnhe_hash_bucket *hash;
 650         struct fib_nh_exception *fnhe;
 651         struct rtable *rt;
 652         u32 genid, hval;
 653         unsigned int i;
 654         int depth;
 655
 656         genid = fnhe_genid(dev_net(nh->nh_dev));
 657         hval = fnhe_hashfun(daddr);
 658
 659         spin_lock_bh(&fnhe_lock);
 660
 661         hash = rcu_dereference(nh->nh_exceptions);
 662         if (!hash) {
 663                 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
 664                 if (!hash)
 665                         goto out_unlock;
 666                 rcu_assign_pointer(nh->nh_exceptions, hash);
 667         }
 668
 669         hash += hval;
 670
 671         depth = 0;
 672         for (fnhe = rcu_dereference(hash->chain); fnhe;
 673              fnhe = rcu_dereference(fnhe->fnhe_next)) {
 674                 if (fnhe->fnhe_daddr == daddr)
 675                         break;
 676                 depth++;
 677         }
 678
 679         if (fnhe) {
 680                 if (fnhe->fnhe_genid != genid)
 681                         fnhe->fnhe_genid = genid;
 682                 if (gw)
 683                         fnhe->fnhe_gw = gw;
 684                 if (pmtu)
 685                         fnhe->fnhe_pmtu = pmtu;
 686                 fnhe->fnhe_expires = max(1UL, expires);
 687                 /* Update all cached dsts too */
 688                 rt = rcu_dereference(fnhe->fnhe_rth_input);
 689                 if (rt)
 690                         fill_route_from_fnhe(rt, fnhe);
 691                 rt = rcu_dereference(fnhe->fnhe_rth_output);
 692                 if (rt)
 693                         fill_route_from_fnhe(rt, fnhe);
 694         } else {
 695                 if (depth > FNHE_RECLAIM_DEPTH)
 696                         fnhe = fnhe_oldest(hash);
 697                 else {
 698                         fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
 699                         if (!fnhe)
 700                                 goto out_unlock;
 701
 702                         fnhe->fnhe_next = hash->chain;
 703                         rcu_assign_pointer(hash->chain, fnhe);
 704                 }
 705                 fnhe->fnhe_genid = genid;
 706                 fnhe->fnhe_daddr = daddr;
 707                 fnhe->fnhe_gw = gw;
 708                 fnhe->fnhe_pmtu = pmtu;
 709                 fnhe->fnhe_expires = expires;
 710
 711                 /* Exception created; mark the cached routes for the nexthop
 712                  * stale, so anyone caching it rechecks if this exception
 713                  * applies to them.
 714                  */
 715                 rt = rcu_dereference(nh->nh_rth_input);
 716                 if (rt)
 717                         rt->dst.obsolete = DST_OBSOLETE_KILL;
 718
 719                 for_each_possible_cpu(i) {
 720                         struct rtable __rcu **prt;
 721                         prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
 722                         rt = rcu_dereference(*prt);
 723                         if (rt)
 724                                 rt->dst.obsolete = DST_OBSOLETE_KILL;
 725                 }
 726         }
 727
 728         fnhe->fnhe_stamp = jiffies;
 729
 730 out_unlock:
 731         spin_unlock_bh(&fnhe_lock);
 732 }
 733
 734 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
 735                              bool kill_route)
 736 {
 737         __be32 new_gw = icmp_hdr(skb)->un.gateway;
 738         __be32 old_gw = ip_hdr(skb)->saddr;
 739         struct net_device *dev = skb->dev;
 740         struct in_device *in_dev;
 741         struct fib_result res;
 742         struct neighbour *n;
 743         struct net *net;
 744
 745         switch (icmp_hdr(skb)->code & 7) {
 746         case ICMP_REDIR_NET:
 747         case ICMP_REDIR_NETTOS:
 748         case ICMP_REDIR_HOST:
 749         case ICMP_REDIR_HOSTTOS:
 750                 break;
 751
 752         default:
 753                 return;
 754         }
 755
 756         if (rt->rt_gateway != old_gw)
 757                 return;
 758
 759         in_dev = __in_dev_get_rcu(dev);
 760         if (!in_dev)
 761                 return;
 762
 763         net = dev_net(dev);
 764         if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
 765             ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
 766             ipv4_is_zeronet(new_gw))
 767                 goto reject_redirect;
 768
 769         if (!IN_DEV_SHARED_MEDIA(in_dev)) {
 770                 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
 771                         goto reject_redirect;
 772                 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
 773                         goto reject_redirect;
 774         } else {
 775                 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
 776                         goto reject_redirect;
 777         }
 778
 779         n = __ipv4_neigh_lookup(rt->dst.dev, new_gw);
 780         if (!n)
 781                 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
 782         if (!IS_ERR(n)) {
 783                 if (!(n->nud_state & NUD_VALID)) {
 784                         neigh_event_send(n, NULL);
 785                 } else {
 786                         if (fib_lookup(net, fl4, &res, 0) == 0) {
 787                                 struct fib_nh *nh = &FIB_RES_NH(res);
 788
 789                                 update_or_create_fnhe(nh, fl4->daddr, new_gw,
 790                                                 0, jiffies + ip_rt_gc_timeout);
 791                         }
 792                         if (kill_route)
 793                                 rt->dst.obsolete = DST_OBSOLETE_KILL;
 794                         call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
 795                 }
 796                 neigh_release(n);
 797         }
 798         return;
 799
 800 reject_redirect:
 801 #ifdef CONFIG_IP_ROUTE_VERBOSE
 802         if (IN_DEV_LOG_MARTIANS(in_dev)) {
 803                 const struct iphdr *iph = (const struct iphdr *) skb->data;
 804                 __be32 daddr = iph->daddr;
 805                 __be32 saddr = iph->saddr;
 806
 807                 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
 808                                      "  Advised path = %pI4 -> %pI4\n",
 809                                      &old_gw, dev->name, &new_gw,
 810                                      &saddr, &daddr);
 811         }
 812 #endif
 813         ;
 814 }
 815
 816 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
 817 {
 818         struct rtable *rt;
 819         struct flowi4 fl4;
 820         const struct iphdr *iph = (const struct iphdr *) skb->data;
 821         struct net *net = dev_net(skb->dev);
 822         int oif = skb->dev->ifindex;
 823         u8 tos = RT_TOS(iph->tos);
 824         u8 prot = iph->protocol;
 825         u32 mark = skb->mark;
 826
 827         rt = (struct rtable *) dst;
 828
 829         __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
 830         __ip_do_redirect(rt, skb, &fl4, true);
 831 }
 832
 833 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
 834 {
 835         struct rtable *rt = (struct rtable *)dst;
 836         struct dst_entry *ret = dst;
 837
 838         if (rt) {
 839                 if (dst->obsolete > 0) {
 840                         ip_rt_put(rt);
 841                         ret = NULL;
 842                 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
 843                            rt->dst.expires) {
 844                         ip_rt_put(rt);
 845                         ret = NULL;
 846                 }
 847         }
 848         return ret;
 849 }
 850
 851 /*
 852  * Algorithm:
 853  *      1. The first ip_rt_redirect_number redirects are sent
 854  *         with exponential backoff, then we stop sending them at all,
 855  *         assuming that the host ignores our redirects.
 856  *      2. If we did not see packets requiring redirects
 857  *         during ip_rt_redirect_silence, we assume that the host
 858  *         forgot redirected route and start to send redirects again.
 859  *
 860  * This algorithm is much cheaper and more intelligent than dumb load limiting
 861  * in icmp.c.
 862  *
 863  * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
 864  * and "frag. need" (breaks PMTU discovery) in icmp.c.
 865  */
 866
 867 void ip_rt_send_redirect(struct sk_buff *skb)
 868 {
 869         struct rtable *rt = skb_rtable(skb);
 870         struct in_device *in_dev;
 871         struct inet_peer *peer;
 872         struct net *net;
 873         int log_martians;
 874         int vif;
 875
 876         rcu_read_lock();
 877         in_dev = __in_dev_get_rcu(rt->dst.dev);
 878         if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
 879                 rcu_read_unlock();
 880                 return;
 881         }
 882         log_martians = IN_DEV_LOG_MARTIANS(in_dev);
 883         vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
 884         rcu_read_unlock();
 885
 886         net = dev_net(rt->dst.dev);
 887         peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
 888         if (!peer) {
 889                 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
 890                           rt_nexthop(rt, ip_hdr(skb)->daddr));
 891                 return;
 892         }
 893
 894         /* No redirected packets during ip_rt_redirect_silence;
 895          * reset the algorithm.
 896          */
 897         if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
 898                 peer->rate_tokens = 0;
 899
 900         /* Too many ignored redirects; do not send anything
 901          * set dst.rate_last to the last seen redirected packet.
 902          */
 903         if (peer->rate_tokens >= ip_rt_redirect_number) {
 904                 peer->rate_last = jiffies;
 905                 goto out_put_peer;
 906         }
 907
 908         /* Check for load limit; set rate_last to the latest sent
 909          * redirect.
 910          */
 911         if (peer->rate_tokens == 0 ||
 912             time_after(jiffies,
 913                        (peer->rate_last +
 914                         (ip_rt_redirect_load << peer->rate_tokens)))) {
 915                 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
 916
 917                 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
 918                 peer->rate_last = jiffies;
 919                 ++peer->rate_tokens;
 920 #ifdef CONFIG_IP_ROUTE_VERBOSE
 921                 if (log_martians &&
 922                     peer->rate_tokens == ip_rt_redirect_number)
 923                         net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
 924                                              &ip_hdr(skb)->saddr, inet_iif(skb),
 925                                              &ip_hdr(skb)->daddr, &gw);
 926 #endif
 927         }
 928 out_put_peer:
 929         inet_putpeer(peer);
 930 }
 931
 932 static int ip_error(struct sk_buff *skb)
 933 {
 934         struct rtable *rt = skb_rtable(skb);
 935         struct net_device *dev = skb->dev;
 936         struct in_device *in_dev;
 937         struct inet_peer *peer;
 938         unsigned long now;
 939         struct net *net;
 940         bool send;
 941         int code;
 942
 943         if (netif_is_l3_master(skb->dev)) {
 944                 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
 945                 if (!dev)
 946                         goto out;
 947         }
 948
 949         in_dev = __in_dev_get_rcu(dev);
 950
 951         /* IP on this device is disabled. */
 952         if (!in_dev)
 953                 goto out;
 954
 955         net = dev_net(rt->dst.dev);
 956         if (!IN_DEV_FORWARD(in_dev)) {
 957                 switch (rt->dst.error) {
 958                 case EHOSTUNREACH:
 959                         __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
 960                         break;
 961
 962                 case ENETUNREACH:
 963                         __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
 964                         break;
 965                 }
 966                 goto out;
 967         }
 968
 969         switch (rt->dst.error) {
 970         case EINVAL:
 971         default:
 972                 goto out;
 973         case EHOSTUNREACH:
 974                 code = ICMP_HOST_UNREACH;
 975                 break;
 976         case ENETUNREACH:
 977                 code = ICMP_NET_UNREACH;
 978                 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
 979                 break;
 980         case EACCES:
 981                 code = ICMP_PKT_FILTERED;
 982                 break;
 983         }
 984
 985         peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
 986                                l3mdev_master_ifindex(skb->dev), 1);
 987
 988         send = true;
 989         if (peer) {
 990                 now = jiffies;
 991                 peer->rate_tokens += now - peer->rate_last;
 992                 if (peer->rate_tokens > ip_rt_error_burst)
 993                         peer->rate_tokens = ip_rt_error_burst;
 994                 peer->rate_last = now;
 995                 if (peer->rate_tokens >= ip_rt_error_cost)
 996                         peer->rate_tokens -= ip_rt_error_cost;
 997                 else
 998                         send = false;
 999                 inet_putpeer(peer);
1000         }
1001         if (send)
1002                 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1003
1004 out:    kfree_skb(skb);
1005         return 0;
1006 }
1007
1008 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1009 {
1010         struct dst_entry *dst = &rt->dst;
1011         struct fib_result res;
1012
1013         if (dst_metric_locked(dst, RTAX_MTU))
1014                 return;
1015
1016         if (ipv4_mtu(dst) < mtu)
1017                 return;
1018
1019         if (mtu < ip_rt_min_pmtu)
1020                 mtu = ip_rt_min_pmtu;
1021
1022         if (rt->rt_pmtu == mtu &&
1023             time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
1024                 return;
1025
1026         rcu_read_lock();
1027         if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
1028                 struct fib_nh *nh = &FIB_RES_NH(res);
1029
1030                 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
1031                                       jiffies + ip_rt_mtu_expires);
1032         }
1033         rcu_read_unlock();
1034 }
1035
1036 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1037                               struct sk_buff *skb, u32 mtu)
1038 {
1039         struct rtable *rt = (struct rtable *) dst;
1040         struct flowi4 fl4;
1041
1042         ip_rt_build_flow_key(&fl4, sk, skb);
1043         __ip_rt_update_pmtu(rt, &fl4, mtu);
1044 }
1045
1046 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1047                       int oif, u32 mark, u8 protocol, int flow_flags)
1048 {
1049         const struct iphdr *iph = (const struct iphdr *) skb->data;
1050         struct flowi4 fl4;
1051         struct rtable *rt;
1052
1053         if (!mark)
1054                 mark = IP4_REPLY_MARK(net, skb->mark);
1055
1056         __build_flow_key(net, &fl4, NULL, iph, oif,
1057                          RT_TOS(iph->tos), protocol, mark, flow_flags);
1058         rt = __ip_route_output_key(net, &fl4);
1059         if (!IS_ERR(rt)) {
1060                 __ip_rt_update_pmtu(rt, &fl4, mtu);
1061                 ip_rt_put(rt);
1062         }
1063 }
1064 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1065
1066 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1067 {
1068         const struct iphdr *iph = (const struct iphdr *) skb->data;
1069         struct flowi4 fl4;
1070         struct rtable *rt;
1071
1072         __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1073
1074         if (!fl4.flowi4_mark)
1075                 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1076
1077         rt = __ip_route_output_key(sock_net(sk), &fl4);
1078         if (!IS_ERR(rt)) {
1079                 __ip_rt_update_pmtu(rt, &fl4, mtu);
1080                 ip_rt_put(rt);
1081         }
1082 }
1083
1084 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1085 {
1086         const struct iphdr *iph = (const struct iphdr *) skb->data;
1087         struct flowi4 fl4;
1088         struct rtable *rt;
1089         struct dst_entry *odst = NULL;
1090         bool new = false;
1091         struct net *net = sock_net(sk);
1092
1093         bh_lock_sock(sk);
1094
1095         if (!ip_sk_accept_pmtu(sk))
1096                 goto out;
1097
1098         odst = sk_dst_get(sk);
1099
1100         if (sock_owned_by_user(sk) || !odst) {
1101                 __ipv4_sk_update_pmtu(skb, sk, mtu);
1102                 goto out;
1103         }
1104
1105         __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1106
1107         rt = (struct rtable *)odst;
1108         if (odst->obsolete && !odst->ops->check(odst, 0)) {
1109                 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1110                 if (IS_ERR(rt))
1111                         goto out;
1112
1113                 new = true;
1114         }
1115
1116         __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu);
1117
1118         if (!dst_check(&rt->dst, 0)) {
1119                 if (new)
1120                         dst_release(&rt->dst);
1121
1122                 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1123                 if (IS_ERR(rt))
1124                         goto out;
1125
1126                 new = true;
1127         }
1128
1129         if (new)
1130                 sk_dst_set(sk, &rt->dst);
1131
1132 out:
1133         bh_unlock_sock(sk);
1134         dst_release(odst);
1135 }
1136 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1137
1138 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1139                    int oif, u32 mark, u8 protocol, int flow_flags)
1140 {
1141         const struct iphdr *iph = (const struct iphdr *) skb->data;
1142         struct flowi4 fl4;
1143         struct rtable *rt;
1144
1145         __build_flow_key(net, &fl4, NULL, iph, oif,
1146                          RT_TOS(iph->tos), protocol, mark, flow_flags);
1147         rt = __ip_route_output_key(net, &fl4);
1148         if (!IS_ERR(rt)) {
1149                 __ip_do_redirect(rt, skb, &fl4, false);
1150                 ip_rt_put(rt);
1151         }
1152 }
1153 EXPORT_SYMBOL_GPL(ipv4_redirect);
1154
1155 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1156 {
1157         const struct iphdr *iph = (const struct iphdr *) skb->data;
1158         struct flowi4 fl4;
1159         struct rtable *rt;
1160         struct net *net = sock_net(sk);
1161
1162         __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1163         rt = __ip_route_output_key(net, &fl4);
1164         if (!IS_ERR(rt)) {
1165                 __ip_do_redirect(rt, skb, &fl4, false);
1166                 ip_rt_put(rt);
1167         }
1168 }
1169 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1170
1171 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1172 {
1173         struct rtable *rt = (struct rtable *) dst;
1174
1175         /* All IPV4 dsts are created with ->obsolete set to the value
1176          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1177          * into this function always.
1178          *
1179          * When a PMTU/redirect information update invalidates a route,
1180          * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1181          * DST_OBSOLETE_DEAD by dst_free().
1182          */
1183         if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1184                 return NULL;
1185         return dst;
1186 }
1187
1188 static void ipv4_link_failure(struct sk_buff *skb)
1189 {
1190         struct rtable *rt;
1191
1192         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1193
1194         rt = skb_rtable(skb);
1195         if (rt)
1196                 dst_set_expires(&rt->dst, 0);
1197 }
1198
1199 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1200 {
1201         pr_debug("%s: %pI4 -> %pI4, %s\n",
1202                  __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1203                  skb->dev ? skb->dev->name : "?");
1204         kfree_skb(skb);
1205         WARN_ON(1);
1206         return 0;
1207 }
1208
1209 /*
1210    We do not cache source address of outgoing interface,
1211    because it is used only by IP RR, TS and SRR options,
1212    so that it out of fast path.
1213
1214    BTW remember: "addr" is allowed to be not aligned
1215    in IP options!
1216  */
1217
1218 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1219 {
1220         __be32 src;
1221
1222         if (rt_is_output_route(rt))
1223                 src = ip_hdr(skb)->saddr;
1224         else {
1225                 struct fib_result res;
1226                 struct flowi4 fl4;
1227                 struct iphdr *iph;
1228
1229                 iph = ip_hdr(skb);
1230
1231                 memset(&fl4, 0, sizeof(fl4));
1232                 fl4.daddr = iph->daddr;
1233                 fl4.saddr = iph->saddr;
1234                 fl4.flowi4_tos = RT_TOS(iph->tos);
1235                 fl4.flowi4_oif = rt->dst.dev->ifindex;
1236                 fl4.flowi4_iif = skb->dev->ifindex;
1237                 fl4.flowi4_mark = skb->mark;
1238
1239                 rcu_read_lock();
1240                 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1241                         src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1242                 else
1243                         src = inet_select_addr(rt->dst.dev,
1244                                                rt_nexthop(rt, iph->daddr),
1245                                                RT_SCOPE_UNIVERSE);
1246                 rcu_read_unlock();
1247         }
1248         memcpy(addr, &src, 4);
1249 }
1250
1251 #ifdef CONFIG_IP_ROUTE_CLASSID
1252 static void set_class_tag(struct rtable *rt, u32 tag)
1253 {
1254         if (!(rt->dst.tclassid & 0xFFFF))
1255                 rt->dst.tclassid |= tag & 0xFFFF;
1256         if (!(rt->dst.tclassid & 0xFFFF0000))
1257                 rt->dst.tclassid |= tag & 0xFFFF0000;
1258 }
1259 #endif
1260
1261 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1262 {
1263         unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1264         unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1265                                     ip_rt_min_advmss);
1266
1267         return min(advmss, IPV4_MAX_PMTU - header_size);
1268 }
1269
1270 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1271 {
1272         const struct rtable *rt = (const struct rtable *) dst;
1273         unsigned int mtu = rt->rt_pmtu;
1274
1275         if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1276                 mtu = dst_metric_raw(dst, RTAX_MTU);
1277
1278         if (mtu)
1279                 return mtu;
1280
1281         mtu = READ_ONCE(dst->dev->mtu);
1282
1283         if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1284                 if (rt->rt_uses_gateway && mtu > 576)
1285                         mtu = 576;
1286         }
1287
1288         mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1289
1290         return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1291 }
1292
1293 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1294 {
1295         struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1296         struct fib_nh_exception *fnhe;
1297         u32 hval;
1298
1299         if (!hash)
1300                 return NULL;
1301
1302         hval = fnhe_hashfun(daddr);
1303
1304         for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1305              fnhe = rcu_dereference(fnhe->fnhe_next)) {
1306                 if (fnhe->fnhe_daddr == daddr)
1307                         return fnhe;
1308         }
1309         return NULL;
1310 }
1311
1312 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1313                               __be32 daddr, const bool do_cache)
1314 {
1315         bool ret = false;
1316
1317         spin_lock_bh(&fnhe_lock);
1318
1319         if (daddr == fnhe->fnhe_daddr) {
1320                 struct rtable __rcu **porig;
1321                 struct rtable *orig;
1322                 int genid = fnhe_genid(dev_net(rt->dst.dev));
1323
1324                 if (rt_is_input_route(rt))
1325                         porig = &fnhe->fnhe_rth_input;
1326                 else
1327                         porig = &fnhe->fnhe_rth_output;
1328                 orig = rcu_dereference(*porig);
1329
1330                 if (fnhe->fnhe_genid != genid) {
1331                         fnhe->fnhe_genid = genid;
1332                         fnhe->fnhe_gw = 0;
1333                         fnhe->fnhe_pmtu = 0;
1334                         fnhe->fnhe_expires = 0;
1335                         fnhe_flush_routes(fnhe);
1336                         orig = NULL;
1337                 }
1338                 fill_route_from_fnhe(rt, fnhe);
1339                 if (!rt->rt_gateway)
1340                         rt->rt_gateway = daddr;
1341
1342                 if (do_cache) {
1343                         dst_hold(&rt->dst);
1344                         rcu_assign_pointer(*porig, rt);
1345                         if (orig) {
1346                                 dst_dev_put(&orig->dst);
1347                                 dst_release(&orig->dst);
1348                         }
1349                         ret = true;
1350                 }
1351
1352                 fnhe->fnhe_stamp = jiffies;
1353         }
1354         spin_unlock_bh(&fnhe_lock);
1355
1356         return ret;
1357 }
1358
1359 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1360 {
1361         struct rtable *orig, *prev, **p;
1362         bool ret = true;
1363
1364         if (rt_is_input_route(rt)) {
1365                 p = (struct rtable **)&nh->nh_rth_input;
1366         } else {
1367                 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1368         }
1369         orig = *p;
1370
1371         /* hold dst before doing cmpxchg() to avoid race condition
1372          * on this dst
1373          */
1374         dst_hold(&rt->dst);
1375         prev = cmpxchg(p, orig, rt);
1376         if (prev == orig) {
1377                 if (orig) {
1378                         dst_dev_put(&orig->dst);
1379                         dst_release(&orig->dst);
1380                 }
1381         } else {
1382                 dst_release(&rt->dst);
1383                 ret = false;
1384         }
1385
1386         return ret;
1387 }
1388
1389 struct uncached_list {
1390         spinlock_t              lock;
1391         struct list_head        head;
1392 };
1393
1394 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1395
1396 static void rt_add_uncached_list(struct rtable *rt)
1397 {
1398         struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1399
1400         rt->rt_uncached_list = ul;
1401
1402         spin_lock_bh(&ul->lock);
1403         list_add_tail(&rt->rt_uncached, &ul->head);
1404         spin_unlock_bh(&ul->lock);
1405 }
1406
1407 static void ipv4_dst_destroy(struct dst_entry *dst)
1408 {
1409         struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
1410         struct rtable *rt = (struct rtable *) dst;
1411
1412         if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
1413                 kfree(p);
1414
1415         if (!list_empty(&rt->rt_uncached)) {
1416                 struct uncached_list *ul = rt->rt_uncached_list;
1417
1418                 spin_lock_bh(&ul->lock);
1419                 list_del(&rt->rt_uncached);
1420                 spin_unlock_bh(&ul->lock);
1421         }
1422 }
1423
1424 void rt_flush_dev(struct net_device *dev)
1425 {
1426         struct net *net = dev_net(dev);
1427         struct rtable *rt;
1428         int cpu;
1429
1430         for_each_possible_cpu(cpu) {
1431                 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1432
1433                 spin_lock_bh(&ul->lock);
1434                 list_for_each_entry(rt, &ul->head, rt_uncached) {
1435                         if (rt->dst.dev != dev)
1436                                 continue;
1437                         rt->dst.dev = net->loopback_dev;
1438                         dev_hold(rt->dst.dev);
1439                         dev_put(dev);
1440                 }
1441                 spin_unlock_bh(&ul->lock);
1442         }
1443 }
1444
1445 static bool rt_cache_valid(const struct rtable *rt)
1446 {
1447         return  rt &&
1448                 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1449                 !rt_is_expired(rt);
1450 }
1451
1452 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1453                            const struct fib_result *res,
1454                            struct fib_nh_exception *fnhe,
1455                            struct fib_info *fi, u16 type, u32 itag,
1456                            const bool do_cache)
1457 {
1458         bool cached = false;
1459
1460         if (fi) {
1461                 struct fib_nh *nh = &FIB_RES_NH(*res);
1462
1463                 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1464                         rt->rt_gateway = nh->nh_gw;
1465                         rt->rt_uses_gateway = 1;
1466                 }
1467                 dst_init_metrics(&rt->dst, fi->fib_metrics->metrics, true);
1468                 if (fi->fib_metrics != &dst_default_metrics) {
1469                         rt->dst._metrics |= DST_METRICS_REFCOUNTED;
1470                         refcount_inc(&fi->fib_metrics->refcnt);
1471                 }
1472 #ifdef CONFIG_IP_ROUTE_CLASSID
1473                 rt->dst.tclassid = nh->nh_tclassid;
1474 #endif
1475                 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1476                 if (unlikely(fnhe))
1477                         cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1478                 else if (do_cache)
1479                         cached = rt_cache_route(nh, rt);
1480                 if (unlikely(!cached)) {
1481                         /* Routes we intend to cache in nexthop exception or
1482                          * FIB nexthop have the DST_NOCACHE bit clear.
1483                          * However, if we are unsuccessful at storing this
1484                          * route into the cache we really need to set it.
1485                          */
1486                         if (!rt->rt_gateway)
1487                                 rt->rt_gateway = daddr;
1488                         rt_add_uncached_list(rt);
1489                 }
1490         } else
1491                 rt_add_uncached_list(rt);
1492
1493 #ifdef CONFIG_IP_ROUTE_CLASSID
1494 #ifdef CONFIG_IP_MULTIPLE_TABLES
1495         set_class_tag(rt, res->tclassid);
1496 #endif
1497         set_class_tag(rt, itag);
1498 #endif
1499 }
1500
1501 struct rtable *rt_dst_alloc(struct net_device *dev,
1502                             unsigned int flags, u16 type,
1503                             bool nopolicy, bool noxfrm, bool will_cache)
1504 {
1505         struct rtable *rt;
1506
1507         rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1508                        (will_cache ? 0 : DST_HOST) |
1509                        (nopolicy ? DST_NOPOLICY : 0) |
1510                        (noxfrm ? DST_NOXFRM : 0));
1511
1512         if (rt) {
1513                 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1514                 rt->rt_flags = flags;
1515                 rt->rt_type = type;
1516                 rt->rt_is_input = 0;
1517                 rt->rt_iif = 0;
1518                 rt->rt_pmtu = 0;
1519                 rt->rt_gateway = 0;
1520                 rt->rt_uses_gateway = 0;
1521                 rt->rt_table_id = 0;
1522                 INIT_LIST_HEAD(&rt->rt_uncached);
1523
1524                 rt->dst.output = ip_output;
1525                 if (flags & RTCF_LOCAL)
1526                         rt->dst.input = ip_local_deliver;
1527         }
1528
1529         return rt;
1530 }
1531 EXPORT_SYMBOL(rt_dst_alloc);
1532
1533 /* called in rcu_read_lock() section */
1534 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1535                           u8 tos, struct net_device *dev,
1536                           struct in_device *in_dev, u32 *itag)
1537 {
1538         int err;
1539
1540         /* Primary sanity checks. */
1541         if (!in_dev)
1542                 return -EINVAL;
1543
1544         if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1545             skb->protocol != htons(ETH_P_IP))
1546                 return -EINVAL;
1547
1548         if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1549                 return -EINVAL;
1550
1551         if (ipv4_is_zeronet(saddr)) {
1552                 if (!ipv4_is_local_multicast(daddr))
1553                         return -EINVAL;
1554         } else {
1555                 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1556                                           in_dev, itag);
1557                 if (err < 0)
1558                         return err;
1559         }
1560         return 0;
1561 }
1562
1563 /* called in rcu_read_lock() section */
1564 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1565                              u8 tos, struct net_device *dev, int our)
1566 {
1567         struct in_device *in_dev = __in_dev_get_rcu(dev);
1568         unsigned int flags = RTCF_MULTICAST;
1569         struct rtable *rth;
1570         u32 itag = 0;
1571         int err;
1572
1573         err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1574         if (err)
1575                 return err;
1576
1577         if (our)
1578                 flags |= RTCF_LOCAL;
1579
1580         rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1581                            IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1582         if (!rth)
1583                 return -ENOBUFS;
1584
1585 #ifdef CONFIG_IP_ROUTE_CLASSID
1586         rth->dst.tclassid = itag;
1587 #endif
1588         rth->dst.output = ip_rt_bug;
1589         rth->rt_is_input= 1;
1590
1591 #ifdef CONFIG_IP_MROUTE
1592         if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1593                 rth->dst.input = ip_mr_input;
1594 #endif
1595         RT_CACHE_STAT_INC(in_slow_mc);
1596
1597         skb_dst_set(skb, &rth->dst);
1598         return 0;
1599 }
1600
1601
1602 static void ip_handle_martian_source(struct net_device *dev,
1603                                      struct in_device *in_dev,
1604                                      struct sk_buff *skb,
1605                                      __be32 daddr,
1606                                      __be32 saddr)
1607 {
1608         RT_CACHE_STAT_INC(in_martian_src);
1609 #ifdef CONFIG_IP_ROUTE_VERBOSE
1610         if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1611                 /*
1612                  *      RFC1812 recommendation, if source is martian,
1613                  *      the only hint is MAC header.
1614                  */
1615                 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1616                         &daddr, &saddr, dev->name);
1617                 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1618                         print_hex_dump(KERN_WARNING, "ll header: ",
1619                                        DUMP_PREFIX_OFFSET, 16, 1,
1620                                        skb_mac_header(skb),
1621                                        dev->hard_header_len, true);
1622                 }
1623         }
1624 #endif
1625 }
1626
1627 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
1628 {
1629         struct fnhe_hash_bucket *hash;
1630         struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1631         u32 hval = fnhe_hashfun(daddr);
1632
1633         spin_lock_bh(&fnhe_lock);
1634
1635         hash = rcu_dereference_protected(nh->nh_exceptions,
1636                                          lockdep_is_held(&fnhe_lock));
1637         hash += hval;
1638
1639         fnhe_p = &hash->chain;
1640         fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1641         while (fnhe) {
1642                 if (fnhe->fnhe_daddr == daddr) {
1643                         rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1644                                 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1645                         fnhe_flush_routes(fnhe);
1646                         kfree_rcu(fnhe, rcu);
1647                         break;
1648                 }
1649                 fnhe_p = &fnhe->fnhe_next;
1650                 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1651                                                  lockdep_is_held(&fnhe_lock));
1652         }
1653
1654         spin_unlock_bh(&fnhe_lock);
1655 }
1656
1657 static void set_lwt_redirect(struct rtable *rth)
1658 {
1659         if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
1660                 rth->dst.lwtstate->orig_output = rth->dst.output;
1661                 rth->dst.output = lwtunnel_output;
1662         }
1663
1664         if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
1665                 rth->dst.lwtstate->orig_input = rth->dst.input;
1666                 rth->dst.input = lwtunnel_input;
1667         }
1668 }
1669
1670 /* called in rcu_read_lock() section */
1671 static int __mkroute_input(struct sk_buff *skb,
1672                            const struct fib_result *res,
1673                            struct in_device *in_dev,
1674                            __be32 daddr, __be32 saddr, u32 tos)
1675 {
1676         struct fib_nh_exception *fnhe;
1677         struct rtable *rth;
1678         int err;
1679         struct in_device *out_dev;
1680         bool do_cache;
1681         u32 itag = 0;
1682
1683         /* get a working reference to the output device */
1684         out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1685         if (!out_dev) {
1686                 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1687                 return -EINVAL;
1688         }
1689
1690         err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1691                                   in_dev->dev, in_dev, &itag);
1692         if (err < 0) {
1693                 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1694                                          saddr);
1695
1696                 goto cleanup;
1697         }
1698
1699         do_cache = res->fi && !itag;
1700         if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1701             skb->protocol == htons(ETH_P_IP) &&
1702             (IN_DEV_SHARED_MEDIA(out_dev) ||
1703              inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1704                 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1705
1706         if (skb->protocol != htons(ETH_P_IP)) {
1707                 /* Not IP (i.e. ARP). Do not create route, if it is
1708                  * invalid for proxy arp. DNAT routes are always valid.
1709                  *
1710                  * Proxy arp feature have been extended to allow, ARP
1711                  * replies back to the same interface, to support
1712                  * Private VLAN switch technologies. See arp.c.
1713                  */
1714                 if (out_dev == in_dev &&
1715                     IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1716                         err = -EINVAL;
1717                         goto cleanup;
1718                 }
1719         }
1720
1721         fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1722         if (do_cache) {
1723                 if (fnhe) {
1724                         rth = rcu_dereference(fnhe->fnhe_rth_input);
1725                         if (rth && rth->dst.expires &&
1726                             time_after(jiffies, rth->dst.expires)) {
1727                                 ip_del_fnhe(&FIB_RES_NH(*res), daddr);
1728                                 fnhe = NULL;
1729                         } else {
1730                                 goto rt_cache;
1731                         }
1732                 }
1733
1734                 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1735
1736 rt_cache:
1737                 if (rt_cache_valid(rth)) {
1738                         skb_dst_set_noref(skb, &rth->dst);
1739                         goto out;
1740                 }
1741         }
1742
1743         rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1744                            IN_DEV_CONF_GET(in_dev, NOPOLICY),
1745                            IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1746         if (!rth) {
1747                 err = -ENOBUFS;
1748                 goto cleanup;
1749         }
1750
1751         rth->rt_is_input = 1;
1752         if (res->table)
1753                 rth->rt_table_id = res->table->tb_id;
1754         RT_CACHE_STAT_INC(in_slow_tot);
1755
1756         rth->dst.input = ip_forward;
1757
1758         rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1759                        do_cache);
1760         set_lwt_redirect(rth);
1761         skb_dst_set(skb, &rth->dst);
1762 out:
1763         err = 0;
1764  cleanup:
1765         return err;
1766 }
1767
1768 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1769 /* To make ICMP packets follow the right flow, the multipath hash is
1770  * calculated from the inner IP addresses.
1771  */
1772 static void ip_multipath_l3_keys(const struct sk_buff *skb,
1773                                  struct flow_keys *hash_keys)
1774 {
1775         const struct iphdr *outer_iph = ip_hdr(skb);
1776         const struct iphdr *inner_iph;
1777         const struct icmphdr *icmph;
1778         struct iphdr _inner_iph;
1779         struct icmphdr _icmph;
1780
1781         hash_keys->addrs.v4addrs.src = outer_iph->saddr;
1782         hash_keys->addrs.v4addrs.dst = outer_iph->daddr;
1783         if (likely(outer_iph->protocol != IPPROTO_ICMP))
1784                 return;
1785
1786         if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1787                 return;
1788
1789         icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1790                                    &_icmph);
1791         if (!icmph)
1792                 return;
1793
1794         if (icmph->type != ICMP_DEST_UNREACH &&
1795             icmph->type != ICMP_REDIRECT &&
1796             icmph->type != ICMP_TIME_EXCEEDED &&
1797             icmph->type != ICMP_PARAMETERPROB)
1798                 return;
1799
1800         inner_iph = skb_header_pointer(skb,
1801                                        outer_iph->ihl * 4 + sizeof(_icmph),
1802                                        sizeof(_inner_iph), &_inner_iph);
1803         if (!inner_iph)
1804                 return;
1805         hash_keys->addrs.v4addrs.src = inner_iph->saddr;
1806         hash_keys->addrs.v4addrs.dst = inner_iph->daddr;
1807 }
1808
1809 /* if skb is set it will be used and fl4 can be NULL */
1810 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
1811                        const struct sk_buff *skb)
1812 {
1813         struct net *net = fi->fib_net;
1814         struct flow_keys hash_keys;
1815         u32 mhash;
1816
1817         switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
1818         case 0:
1819                 memset(&hash_keys, 0, sizeof(hash_keys));
1820                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1821                 if (skb) {
1822                         ip_multipath_l3_keys(skb, &hash_keys);
1823                 } else {
1824                         hash_keys.addrs.v4addrs.src = fl4->saddr;
1825                         hash_keys.addrs.v4addrs.dst = fl4->daddr;
1826                 }
1827                 break;
1828         case 1:
1829                 /* skb is currently provided only when forwarding */
1830                 if (skb) {
1831                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
1832                         struct flow_keys keys;
1833
1834                         /* short-circuit if we already have L4 hash present */
1835                         if (skb->l4_hash)
1836                                 return skb_get_hash_raw(skb) >> 1;
1837                         memset(&hash_keys, 0, sizeof(hash_keys));
1838                         skb_flow_dissect_flow_keys(skb, &keys, flag);
1839
1840                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1841                         hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1842                         hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1843                         hash_keys.ports.src = keys.ports.src;
1844                         hash_keys.ports.dst = keys.ports.dst;
1845                         hash_keys.basic.ip_proto = keys.basic.ip_proto;
1846                 } else {
1847                         memset(&hash_keys, 0, sizeof(hash_keys));
1848                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1849                         hash_keys.addrs.v4addrs.src = fl4->saddr;
1850                         hash_keys.addrs.v4addrs.dst = fl4->daddr;
1851                         hash_keys.ports.src = fl4->fl4_sport;
1852                         hash_keys.ports.dst = fl4->fl4_dport;
1853                         hash_keys.basic.ip_proto = fl4->flowi4_proto;
1854                 }
1855                 break;
1856         }
1857         mhash = flow_hash_from_keys(&hash_keys);
1858
1859         return mhash >> 1;
1860 }
1861 EXPORT_SYMBOL_GPL(fib_multipath_hash);
1862 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1863
1864 static int ip_mkroute_input(struct sk_buff *skb,
1865                             struct fib_result *res,
1866                             struct in_device *in_dev,
1867                             __be32 daddr, __be32 saddr, u32 tos)
1868 {
1869 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1870         if (res->fi && res->fi->fib_nhs > 1) {
1871                 int h = fib_multipath_hash(res->fi, NULL, skb);
1872
1873                 fib_select_multipath(res, h);
1874         }
1875 #endif
1876
1877         /* create a routing cache entry */
1878         return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1879 }
1880
1881 /*
1882  *      NOTE. We drop all the packets that has local source
1883  *      addresses, because every properly looped back packet
1884  *      must have correct destination already attached by output routine.
1885  *
1886  *      Such approach solves two big problems:
1887  *      1. Not simplex devices are handled properly.
1888  *      2. IP spoofing attempts are filtered with 100% of guarantee.
1889  *      called with rcu_read_lock()
1890  */
1891
1892 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1893                                u8 tos, struct net_device *dev,
1894                                struct fib_result *res)
1895 {
1896         struct in_device *in_dev = __in_dev_get_rcu(dev);
1897         struct ip_tunnel_info *tun_info;
1898         struct flowi4   fl4;
1899         unsigned int    flags = 0;
1900         u32             itag = 0;
1901         struct rtable   *rth;
1902         int             err = -EINVAL;
1903         struct net    *net = dev_net(dev);
1904         bool do_cache;
1905
1906         /* IP on this device is disabled. */
1907
1908         if (!in_dev)
1909                 goto out;
1910
1911         /* Check for the most weird martians, which can be not detected
1912            by fib_lookup.
1913          */
1914
1915         tun_info = skb_tunnel_info(skb);
1916         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1917                 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1918         else
1919                 fl4.flowi4_tun_key.tun_id = 0;
1920         skb_dst_drop(skb);
1921
1922         if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1923                 goto martian_source;
1924
1925         res->fi = NULL;
1926         res->table = NULL;
1927         if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1928                 goto brd_input;
1929
1930         /* Accept zero addresses only to limited broadcast;
1931          * I even do not know to fix it or not. Waiting for complains :-)
1932          */
1933         if (ipv4_is_zeronet(saddr))
1934                 goto martian_source;
1935
1936         if (ipv4_is_zeronet(daddr))
1937                 goto martian_destination;
1938
1939         /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1940          * and call it once if daddr or/and saddr are loopback addresses
1941          */
1942         if (ipv4_is_loopback(daddr)) {
1943                 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1944                         goto martian_destination;
1945         } else if (ipv4_is_loopback(saddr)) {
1946                 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1947                         goto martian_source;
1948         }
1949
1950         /*
1951          *      Now we are ready to route packet.
1952          */
1953         fl4.flowi4_oif = 0;
1954         fl4.flowi4_iif = dev->ifindex;
1955         fl4.flowi4_mark = skb->mark;
1956         fl4.flowi4_tos = tos;
1957         fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1958         fl4.flowi4_flags = 0;
1959         fl4.daddr = daddr;
1960         fl4.saddr = saddr;
1961         fl4.flowi4_uid = sock_net_uid(net, NULL);
1962         err = fib_lookup(net, &fl4, res, 0);
1963         if (err != 0) {
1964                 if (!IN_DEV_FORWARD(in_dev))
1965                         err = -EHOSTUNREACH;
1966                 goto no_route;
1967         }
1968
1969         if (res->type == RTN_BROADCAST)
1970                 goto brd_input;
1971
1972         if (res->type == RTN_LOCAL) {
1973                 err = fib_validate_source(skb, saddr, daddr, tos,
1974                                           0, dev, in_dev, &itag);
1975                 if (err < 0)
1976                         goto martian_source;
1977                 goto local_input;
1978         }
1979
1980         if (!IN_DEV_FORWARD(in_dev)) {
1981                 err = -EHOSTUNREACH;
1982                 goto no_route;
1983         }
1984         if (res->type != RTN_UNICAST)
1985                 goto martian_destination;
1986
1987         err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1988 out:    return err;
1989
1990 brd_input:
1991         if (skb->protocol != htons(ETH_P_IP))
1992                 goto e_inval;
1993
1994         if (!ipv4_is_zeronet(saddr)) {
1995                 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1996                                           in_dev, &itag);
1997                 if (err < 0)
1998                         goto martian_source;
1999         }
2000         flags |= RTCF_BROADCAST;
2001         res->type = RTN_BROADCAST;
2002         RT_CACHE_STAT_INC(in_brd);
2003
2004 local_input:
2005         do_cache = false;
2006         if (res->fi) {
2007                 if (!itag) {
2008                         rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
2009                         if (rt_cache_valid(rth)) {
2010                                 skb_dst_set_noref(skb, &rth->dst);
2011                                 err = 0;
2012                                 goto out;
2013                         }
2014                         do_cache = true;
2015                 }
2016         }
2017
2018         rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
2019                            flags | RTCF_LOCAL, res->type,
2020                            IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
2021         if (!rth)
2022                 goto e_nobufs;
2023
2024         rth->dst.output= ip_rt_bug;
2025 #ifdef CONFIG_IP_ROUTE_CLASSID
2026         rth->dst.tclassid = itag;
2027 #endif
2028         rth->rt_is_input = 1;
2029         if (res->table)
2030                 rth->rt_table_id = res->table->tb_id;
2031
2032         RT_CACHE_STAT_INC(in_slow_tot);
2033         if (res->type == RTN_UNREACHABLE) {
2034                 rth->dst.input= ip_error;
2035                 rth->dst.error= -err;
2036                 rth->rt_flags   &= ~RTCF_LOCAL;
2037         }
2038
2039         if (do_cache) {
2040                 struct fib_nh *nh = &FIB_RES_NH(*res);
2041
2042                 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
2043                 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2044                         WARN_ON(rth->dst.input == lwtunnel_input);
2045                         rth->dst.lwtstate->orig_input = rth->dst.input;
2046                         rth->dst.input = lwtunnel_input;
2047                 }
2048
2049                 if (unlikely(!rt_cache_route(nh, rth)))
2050                         rt_add_uncached_list(rth);
2051         }
2052         skb_dst_set(skb, &rth->dst);
2053         err = 0;
2054         goto out;
2055
2056 no_route:
2057         RT_CACHE_STAT_INC(in_no_route);
2058         res->type = RTN_UNREACHABLE;
2059         res->fi = NULL;
2060         res->table = NULL;
2061         goto local_input;
2062
2063         /*
2064          *      Do not cache martian addresses: they should be logged (RFC1812)
2065          */
2066 martian_destination:
2067         RT_CACHE_STAT_INC(in_martian_dst);
2068 #ifdef CONFIG_IP_ROUTE_VERBOSE
2069         if (IN_DEV_LOG_MARTIANS(in_dev))
2070                 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2071                                      &daddr, &saddr, dev->name);
2072 #endif
2073
2074 e_inval:
2075         err = -EINVAL;
2076         goto out;
2077
2078 e_nobufs:
2079         err = -ENOBUFS;
2080         goto out;
2081
2082 martian_source:
2083         ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2084         goto out;
2085 }
2086
2087 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2088                          u8 tos, struct net_device *dev)
2089 {
2090         struct fib_result res;
2091         int err;
2092
2093         tos &= IPTOS_RT_MASK;
2094         rcu_read_lock();
2095         err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2096         rcu_read_unlock();
2097
2098         return err;
2099 }
2100 EXPORT_SYMBOL(ip_route_input_noref);
2101
2102 /* called with rcu_read_lock held */
2103 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2104                        u8 tos, struct net_device *dev, struct fib_result *res)
2105 {
2106         /* Multicast recognition logic is moved from route cache to here.
2107            The problem was that too many Ethernet cards have broken/missing
2108            hardware multicast filters :-( As result the host on multicasting
2109            network acquires a lot of useless route cache entries, sort of
2110            SDR messages from all the world. Now we try to get rid of them.
2111            Really, provided software IP multicast filter is organized
2112            reasonably (at least, hashed), it does not result in a slowdown
2113            comparing with route cache reject entries.
2114            Note, that multicast routers are not affected, because
2115            route cache entry is created eventually.
2116          */
2117         if (ipv4_is_multicast(daddr)) {
2118                 struct in_device *in_dev = __in_dev_get_rcu(dev);
2119                 int our = 0;
2120                 int err = -EINVAL;
2121
2122                 if (in_dev)
2123                         our = ip_check_mc_rcu(in_dev, daddr, saddr,
2124                                               ip_hdr(skb)->protocol);
2125
2126                 /* check l3 master if no match yet */
2127                 if ((!in_dev || !our) && netif_is_l3_slave(dev)) {
2128                         struct in_device *l3_in_dev;
2129
2130                         l3_in_dev = __in_dev_get_rcu(skb->dev);
2131                         if (l3_in_dev)
2132                                 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2133                                                       ip_hdr(skb)->protocol);
2134                 }
2135
2136                 if (our
2137 #ifdef CONFIG_IP_MROUTE
2138                         ||
2139                     (!ipv4_is_local_multicast(daddr) &&
2140                      IN_DEV_MFORWARD(in_dev))
2141 #endif
2142                    ) {
2143                         err = ip_route_input_mc(skb, daddr, saddr,
2144                                                 tos, dev, our);
2145                 }
2146                 return err;
2147         }
2148
2149         return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2150 }
2151
2152 /* called with rcu_read_lock() */
2153 static struct rtable *__mkroute_output(const struct fib_result *res,
2154                                        const struct flowi4 *fl4, int orig_oif,
2155                                        struct net_device *dev_out,
2156                                        unsigned int flags)
2157 {
2158         struct fib_info *fi = res->fi;
2159         struct fib_nh_exception *fnhe;
2160         struct in_device *in_dev;
2161         u16 type = res->type;
2162         struct rtable *rth;
2163         bool do_cache;
2164
2165         in_dev = __in_dev_get_rcu(dev_out);
2166         if (!in_dev)
2167                 return ERR_PTR(-EINVAL);
2168
2169         if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2170                 if (ipv4_is_loopback(fl4->saddr) &&
2171                     !(dev_out->flags & IFF_LOOPBACK) &&
2172                     !netif_is_l3_master(dev_out))
2173                         return ERR_PTR(-EINVAL);
2174
2175         if (ipv4_is_lbcast(fl4->daddr))
2176                 type = RTN_BROADCAST;
2177         else if (ipv4_is_multicast(fl4->daddr))
2178                 type = RTN_MULTICAST;
2179         else if (ipv4_is_zeronet(fl4->daddr))
2180                 return ERR_PTR(-EINVAL);
2181
2182         if (dev_out->flags & IFF_LOOPBACK)
2183                 flags |= RTCF_LOCAL;
2184
2185         do_cache = true;
2186         if (type == RTN_BROADCAST) {
2187                 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2188                 fi = NULL;
2189         } else if (type == RTN_MULTICAST) {
2190                 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2191                 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2192                                      fl4->flowi4_proto))
2193                         flags &= ~RTCF_LOCAL;
2194                 else
2195                         do_cache = false;
2196                 /* If multicast route do not exist use
2197                  * default one, but do not gateway in this case.
2198                  * Yes, it is hack.
2199                  */
2200                 if (fi && res->prefixlen < 4)
2201                         fi = NULL;
2202         } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2203                    (orig_oif != dev_out->ifindex)) {
2204                 /* For local routes that require a particular output interface
2205                  * we do not want to cache the result.  Caching the result
2206                  * causes incorrect behaviour when there are multiple source
2207                  * addresses on the interface, the end result being that if the
2208                  * intended recipient is waiting on that interface for the
2209                  * packet he won't receive it because it will be delivered on
2210                  * the loopback interface and the IP_PKTINFO ipi_ifindex will
2211                  * be set to the loopback interface as well.
2212                  */
2213                 fi = NULL;
2214         }
2215
2216         fnhe = NULL;
2217         do_cache &= fi != NULL;
2218         if (do_cache) {
2219                 struct rtable __rcu **prth;
2220                 struct fib_nh *nh = &FIB_RES_NH(*res);
2221
2222                 fnhe = find_exception(nh, fl4->daddr);
2223                 if (fnhe) {
2224                         prth = &fnhe->fnhe_rth_output;
2225                         rth = rcu_dereference(*prth);
2226                         if (rth && rth->dst.expires &&
2227                             time_after(jiffies, rth->dst.expires)) {
2228                                 ip_del_fnhe(nh, fl4->daddr);
2229                                 fnhe = NULL;
2230                         } else {
2231                                 goto rt_cache;
2232                         }
2233                 }
2234
2235                 if (unlikely(fl4->flowi4_flags &
2236                              FLOWI_FLAG_KNOWN_NH &&
2237                              !(nh->nh_gw &&
2238                                nh->nh_scope == RT_SCOPE_LINK))) {
2239                         do_cache = false;
2240                         goto add;
2241                 }
2242                 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2243                 rth = rcu_dereference(*prth);
2244
2245 rt_cache:
2246                 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2247                         return rth;
2248         }
2249
2250 add:
2251         rth = rt_dst_alloc(dev_out, flags, type,
2252                            IN_DEV_CONF_GET(in_dev, NOPOLICY),
2253                            IN_DEV_CONF_GET(in_dev, NOXFRM),
2254                            do_cache);
2255         if (!rth)
2256                 return ERR_PTR(-ENOBUFS);
2257
2258         rth->rt_iif = orig_oif;
2259         if (res->table)
2260                 rth->rt_table_id = res->table->tb_id;
2261
2262         RT_CACHE_STAT_INC(out_slow_tot);
2263
2264         if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2265                 if (flags & RTCF_LOCAL &&
2266                     !(dev_out->flags & IFF_LOOPBACK)) {
2267                         rth->dst.output = ip_mc_output;
2268                         RT_CACHE_STAT_INC(out_slow_mc);
2269                 }
2270 #ifdef CONFIG_IP_MROUTE
2271                 if (type == RTN_MULTICAST) {
2272                         if (IN_DEV_MFORWARD(in_dev) &&
2273                             !ipv4_is_local_multicast(fl4->daddr)) {
2274                                 rth->dst.input = ip_mr_input;
2275                                 rth->dst.output = ip_mc_output;
2276                         }
2277                 }
2278 #endif
2279         }
2280
2281         rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2282         set_lwt_redirect(rth);
2283
2284         return rth;
2285 }
2286
2287 /*
2288  * Major route resolver routine.
2289  */
2290
2291 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2292                                         const struct sk_buff *skb)
2293 {
2294         __u8 tos = RT_FL_TOS(fl4);
2295         struct fib_result res;
2296         struct rtable *rth;
2297
2298         res.tclassid    = 0;
2299         res.fi          = NULL;
2300         res.table       = NULL;
2301
2302         fl4->flowi4_iif = LOOPBACK_IFINDEX;
2303         fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2304         fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2305                          RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2306
2307         rcu_read_lock();
2308         rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2309         rcu_read_unlock();
2310
2311         return rth;
2312 }
2313 EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2314
2315 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2316                                             struct fib_result *res,
2317                                             const struct sk_buff *skb)
2318 {
2319         struct net_device *dev_out = NULL;
2320         int orig_oif = fl4->flowi4_oif;
2321         unsigned int flags = 0;
2322         struct rtable *rth;
2323         int err = -ENETUNREACH;
2324
2325         if (fl4->saddr) {
2326                 rth = ERR_PTR(-EINVAL);
2327                 if (ipv4_is_multicast(fl4->saddr) ||
2328                     ipv4_is_lbcast(fl4->saddr) ||
2329                     ipv4_is_zeronet(fl4->saddr))
2330                         goto out;
2331
2332                 /* I removed check for oif == dev_out->oif here.
2333                    It was wrong for two reasons:
2334                    1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2335                       is assigned to multiple interfaces.
2336                    2. Moreover, we are allowed to send packets with saddr
2337                       of another iface. --ANK
2338                  */
2339
2340                 if (fl4->flowi4_oif == 0 &&
2341                     (ipv4_is_multicast(fl4->daddr) ||
2342                      ipv4_is_lbcast(fl4->daddr))) {
2343                         /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2344                         dev_out = __ip_dev_find(net, fl4->saddr, false);
2345                         if (!dev_out)
2346                                 goto out;
2347
2348                         /* Special hack: user can direct multicasts
2349                            and limited broadcast via necessary interface
2350                            without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2351                            This hack is not just for fun, it allows
2352                            vic,vat and friends to work.
2353                            They bind socket to loopback, set ttl to zero
2354                            and expect that it will work.
2355                            From the viewpoint of routing cache they are broken,
2356                            because we are not allowed to build multicast path
2357                            with loopback source addr (look, routing cache
2358                            cannot know, that ttl is zero, so that packet
2359                            will not leave this host and route is valid).
2360                            Luckily, this hack is good workaround.
2361                          */
2362
2363                         fl4->flowi4_oif = dev_out->ifindex;
2364                         goto make_route;
2365                 }
2366
2367                 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2368                         /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2369                         if (!__ip_dev_find(net, fl4->saddr, false))
2370                                 goto out;
2371                 }
2372         }
2373
2374
2375         if (fl4->flowi4_oif) {
2376                 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2377                 rth = ERR_PTR(-ENODEV);
2378                 if (!dev_out)
2379                         goto out;
2380
2381                 /* RACE: Check return value of inet_select_addr instead. */
2382                 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2383                         rth = ERR_PTR(-ENETUNREACH);
2384                         goto out;
2385                 }
2386                 if (ipv4_is_local_multicast(fl4->daddr) ||
2387                     ipv4_is_lbcast(fl4->daddr) ||
2388                     fl4->flowi4_proto == IPPROTO_IGMP) {
2389                         if (!fl4->saddr)
2390                                 fl4->saddr = inet_select_addr(dev_out, 0,
2391                                                               RT_SCOPE_LINK);
2392                         goto make_route;
2393                 }
2394                 if (!fl4->saddr) {
2395                         if (ipv4_is_multicast(fl4->daddr))
2396                                 fl4->saddr = inet_select_addr(dev_out, 0,
2397                                                               fl4->flowi4_scope);
2398                         else if (!fl4->daddr)
2399                                 fl4->saddr = inet_select_addr(dev_out, 0,
2400                                                               RT_SCOPE_HOST);
2401                 }
2402         }
2403
2404         if (!fl4->daddr) {
2405                 fl4->daddr = fl4->saddr;
2406                 if (!fl4->daddr)
2407                         fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2408                 dev_out = net->loopback_dev;
2409                 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2410                 res->type = RTN_LOCAL;
2411                 flags |= RTCF_LOCAL;
2412                 goto make_route;
2413         }
2414
2415         err = fib_lookup(net, fl4, res, 0);
2416         if (err) {
2417                 res->fi = NULL;
2418                 res->table = NULL;
2419                 if (fl4->flowi4_oif &&
2420                     (ipv4_is_multicast(fl4->daddr) ||
2421                     !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
2422                         /* Apparently, routing tables are wrong. Assume,
2423                            that the destination is on link.
2424
2425                            WHY? DW.
2426                            Because we are allowed to send to iface
2427                            even if it has NO routes and NO assigned
2428                            addresses. When oif is specified, routing
2429                            tables are looked up with only one purpose:
2430                            to catch if destination is gatewayed, rather than
2431                            direct. Moreover, if MSG_DONTROUTE is set,
2432                            we send packet, ignoring both routing tables
2433                            and ifaddr state. --ANK
2434
2435
2436                            We could make it even if oif is unknown,
2437                            likely IPv6, but we do not.
2438                          */
2439
2440                         if (fl4->saddr == 0)
2441                                 fl4->saddr = inet_select_addr(dev_out, 0,
2442                                                               RT_SCOPE_LINK);
2443                         res->type = RTN_UNICAST;
2444                         goto make_route;
2445                 }
2446                 rth = ERR_PTR(err);
2447                 goto out;
2448         }
2449
2450         if (res->type == RTN_LOCAL) {
2451                 if (!fl4->saddr) {
2452                         if (res->fi->fib_prefsrc)
2453                                 fl4->saddr = res->fi->fib_prefsrc;
2454                         else
2455                                 fl4->saddr = fl4->daddr;
2456                 }
2457
2458                 /* L3 master device is the loopback for that domain */
2459                 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2460                         net->loopback_dev;
2461
2462                 /* make sure orig_oif points to fib result device even
2463                  * though packet rx/tx happens over loopback or l3mdev
2464                  */
2465                 orig_oif = FIB_RES_OIF(*res);
2466
2467                 fl4->flowi4_oif = dev_out->ifindex;
2468                 flags |= RTCF_LOCAL;
2469                 goto make_route;
2470         }
2471
2472         fib_select_path(net, res, fl4, skb);
2473
2474         dev_out = FIB_RES_DEV(*res);
2475         fl4->flowi4_oif = dev_out->ifindex;
2476
2477
2478 make_route:
2479         rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2480
2481 out:
2482         return rth;
2483 }
2484
2485 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2486 {
2487         return NULL;
2488 }
2489
2490 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2491 {
2492         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2493
2494         return mtu ? : dst->dev->mtu;
2495 }
2496
2497 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2498                                           struct sk_buff *skb, u32 mtu)
2499 {
2500 }
2501
2502 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2503                                        struct sk_buff *skb)
2504 {
2505 }
2506
2507 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2508                                           unsigned long old)
2509 {
2510         return NULL;
2511 }
2512
2513 static struct dst_ops ipv4_dst_blackhole_ops = {
2514         .family                 =       AF_INET,
2515         .check                  =       ipv4_blackhole_dst_check,
2516         .mtu                    =       ipv4_blackhole_mtu,
2517         .default_advmss         =       ipv4_default_advmss,
2518         .update_pmtu            =       ipv4_rt_blackhole_update_pmtu,
2519         .redirect               =       ipv4_rt_blackhole_redirect,
2520         .cow_metrics            =       ipv4_rt_blackhole_cow_metrics,
2521         .neigh_lookup           =       ipv4_neigh_lookup,
2522 };
2523
2524 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2525 {
2526         struct rtable *ort = (struct rtable *) dst_orig;
2527         struct rtable *rt;
2528
2529         rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
2530         if (rt) {
2531                 struct dst_entry *new = &rt->dst;
2532
2533                 new->__use = 1;
2534                 new->input = dst_discard;
2535                 new->output = dst_discard_out;
2536
2537                 new->dev = net->loopback_dev;
2538                 if (new->dev)
2539                         dev_hold(new->dev);
2540
2541                 rt->rt_is_input = ort->rt_is_input;
2542                 rt->rt_iif = ort->rt_iif;
2543                 rt->rt_pmtu = ort->rt_pmtu;
2544
2545                 rt->rt_genid = rt_genid_ipv4(net);
2546                 rt->rt_flags = ort->rt_flags;
2547                 rt->rt_type = ort->rt_type;
2548                 rt->rt_gateway = ort->rt_gateway;
2549                 rt->rt_uses_gateway = ort->rt_uses_gateway;
2550
2551                 INIT_LIST_HEAD(&rt->rt_uncached);
2552         }
2553
2554         dst_release(dst_orig);
2555
2556         return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2557 }
2558
2559 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2560                                     const struct sock *sk)
2561 {
2562         struct rtable *rt = __ip_route_output_key(net, flp4);
2563
2564         if (IS_ERR(rt))
2565                 return rt;
2566
2567         if (flp4->flowi4_proto)
2568                 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2569                                                         flowi4_to_flowi(flp4),
2570                                                         sk, 0);
2571
2572         return rt;
2573 }
2574 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2575
2576 /* called with rcu_read_lock held */
2577 static int rt_fill_info(struct net *net,  __be32 dst, __be32 src, u32 table_id,
2578                         struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2579                         u32 seq)
2580 {
2581         struct rtable *rt = skb_rtable(skb);
2582         struct rtmsg *r;
2583         struct nlmsghdr *nlh;
2584         unsigned long expires = 0;
2585         u32 error;
2586         u32 metrics[RTAX_MAX];
2587
2588         nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0);
2589         if (!nlh)
2590                 return -EMSGSIZE;
2591
2592         r = nlmsg_data(nlh);
2593         r->rtm_family    = AF_INET;
2594         r->rtm_dst_len  = 32;
2595         r->rtm_src_len  = 0;
2596         r->rtm_tos      = fl4->flowi4_tos;
2597         r->rtm_table    = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2598         if (nla_put_u32(skb, RTA_TABLE, table_id))
2599                 goto nla_put_failure;
2600         r->rtm_type     = rt->rt_type;
2601         r->rtm_scope    = RT_SCOPE_UNIVERSE;
2602         r->rtm_protocol = RTPROT_UNSPEC;
2603         r->rtm_flags    = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2604         if (rt->rt_flags & RTCF_NOTIFY)
2605                 r->rtm_flags |= RTM_F_NOTIFY;
2606         if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2607                 r->rtm_flags |= RTCF_DOREDIRECT;
2608
2609         if (nla_put_in_addr(skb, RTA_DST, dst))
2610                 goto nla_put_failure;
2611         if (src) {
2612                 r->rtm_src_len = 32;
2613                 if (nla_put_in_addr(skb, RTA_SRC, src))
2614                         goto nla_put_failure;
2615         }
2616         if (rt->dst.dev &&
2617             nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2618                 goto nla_put_failure;
2619 #ifdef CONFIG_IP_ROUTE_CLASSID
2620         if (rt->dst.tclassid &&
2621             nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2622                 goto nla_put_failure;
2623 #endif
2624         if (!rt_is_input_route(rt) &&
2625             fl4->saddr != src) {
2626                 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2627                         goto nla_put_failure;
2628         }
2629         if (rt->rt_uses_gateway &&
2630             nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2631                 goto nla_put_failure;
2632
2633         expires = rt->dst.expires;
2634         if (expires) {
2635                 unsigned long now = jiffies;
2636
2637                 if (time_before(now, expires))
2638                         expires -= now;
2639                 else
2640                         expires = 0;
2641         }
2642
2643         memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2644         if (rt->rt_pmtu && expires)
2645                 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2646         if (rtnetlink_put_metrics(skb, metrics) < 0)
2647                 goto nla_put_failure;
2648
2649         if (fl4->flowi4_mark &&
2650             nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2651                 goto nla_put_failure;
2652
2653         if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2654             nla_put_u32(skb, RTA_UID,
2655                         from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2656                 goto nla_put_failure;
2657
2658         error = rt->dst.error;
2659
2660         if (rt_is_input_route(rt)) {
2661 #ifdef CONFIG_IP_MROUTE
2662                 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2663                     IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2664                         int err = ipmr_get_route(net, skb,
2665                                                  fl4->saddr, fl4->daddr,
2666                                                  r, portid);
2667
2668                         if (err <= 0) {
2669                                 if (err == 0)
2670                                         return 0;
2671                                 goto nla_put_failure;
2672                         }
2673                 } else
2674 #endif
2675                         if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2676                                 goto nla_put_failure;
2677         }
2678
2679         if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2680                 goto nla_put_failure;
2681
2682         nlmsg_end(skb, nlh);
2683         return 0;
2684
2685 nla_put_failure:
2686         nlmsg_cancel(skb, nlh);
2687         return -EMSGSIZE;
2688 }
2689
2690 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2691                              struct netlink_ext_ack *extack)
2692 {
2693         struct net *net = sock_net(in_skb->sk);
2694         struct rtmsg *rtm;
2695         struct nlattr *tb[RTA_MAX+1];
2696         struct fib_result res = {};
2697         struct rtable *rt = NULL;
2698         struct flowi4 fl4;
2699         __be32 dst = 0;
2700         __be32 src = 0;
2701         u32 iif;
2702         int err;
2703         int mark;
2704         struct sk_buff *skb;
2705         u32 table_id = RT_TABLE_MAIN;
2706         kuid_t uid;
2707
2708         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy,
2709                           extack);
2710         if (err < 0)
2711                 goto errout;
2712
2713         rtm = nlmsg_data(nlh);
2714
2715         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2716         if (!skb) {
2717                 err = -ENOBUFS;
2718                 goto errout;
2719         }
2720
2721         /* Reserve room for dummy headers, this skb can pass
2722            through good chunk of routing engine.
2723          */
2724         skb_reset_mac_header(skb);
2725         skb_reset_network_header(skb);
2726
2727         src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2728         dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2729         iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2730         mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2731         if (tb[RTA_UID])
2732                 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2733         else
2734                 uid = (iif ? INVALID_UID : current_uid());
2735
2736         /* Bugfix: need to give ip_route_input enough of an IP header to
2737          * not gag.
2738          */
2739         ip_hdr(skb)->protocol = IPPROTO_UDP;
2740         ip_hdr(skb)->saddr = src;
2741         ip_hdr(skb)->daddr = dst;
2742
2743         skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2744
2745         memset(&fl4, 0, sizeof(fl4));
2746         fl4.daddr = dst;
2747         fl4.saddr = src;
2748         fl4.flowi4_tos = rtm->rtm_tos;
2749         fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2750         fl4.flowi4_mark = mark;
2751         fl4.flowi4_uid = uid;
2752
2753         rcu_read_lock();
2754
2755         if (iif) {
2756                 struct net_device *dev;
2757
2758                 dev = dev_get_by_index_rcu(net, iif);
2759                 if (!dev) {
2760                         err = -ENODEV;
2761                         goto errout_free;
2762                 }
2763
2764                 skb->protocol   = htons(ETH_P_IP);
2765                 skb->dev        = dev;
2766                 skb->mark       = mark;
2767                 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
2768                                          dev, &res);
2769
2770                 rt = skb_rtable(skb);
2771                 if (err == 0 && rt->dst.error)
2772                         err = -rt->dst.error;
2773         } else {
2774                 fl4.flowi4_iif = LOOPBACK_IFINDEX;
2775                 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
2776                 err = 0;
2777                 if (IS_ERR(rt))
2778                         err = PTR_ERR(rt);
2779                 else
2780                         skb_dst_set(skb, &rt->dst);
2781         }
2782
2783         if (err)
2784                 goto errout_free;
2785
2786         if (rtm->rtm_flags & RTM_F_NOTIFY)
2787                 rt->rt_flags |= RTCF_NOTIFY;
2788
2789         if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2790                 table_id = rt->rt_table_id;
2791
2792         if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2793                 if (!res.fi) {
2794                         err = fib_props[res.type].error;
2795                         if (!err)
2796                                 err = -EHOSTUNREACH;
2797                         goto errout_free;
2798                 }
2799                 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
2800                                     nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
2801                                     rt->rt_type, res.prefix, res.prefixlen,
2802                                     fl4.flowi4_tos, res.fi, 0);
2803         } else {
2804                 err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
2805                                    NETLINK_CB(in_skb).portid, nlh->nlmsg_seq);
2806         }
2807         if (err < 0)
2808                 goto errout_free;
2809
2810         rcu_read_unlock();
2811
2812         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2813 errout:
2814         return err;
2815
2816 errout_free:
2817         rcu_read_unlock();
2818         kfree_skb(skb);
2819         goto errout;
2820 }
2821
2822 void ip_rt_multicast_event(struct in_device *in_dev)
2823 {
2824         rt_cache_flush(dev_net(in_dev->dev));
2825 }
2826
2827 #ifdef CONFIG_SYSCTL
2828 static int ip_rt_gc_interval __read_mostly  = 60 * HZ;
2829 static int ip_rt_gc_min_interval __read_mostly  = HZ / 2;
2830 static int ip_rt_gc_elasticity __read_mostly    = 8;
2831 static int ip_min_valid_pmtu __read_mostly      = IPV4_MIN_MTU;
2832
2833 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2834                                         void __user *buffer,
2835                                         size_t *lenp, loff_t *ppos)
2836 {
2837         struct net *net = (struct net *)__ctl->extra1;
2838
2839         if (write) {
2840                 rt_cache_flush(net);
2841                 fnhe_genid_bump(net);
2842                 return 0;
2843         }
2844
2845         return -EINVAL;
2846 }
2847
2848 static struct ctl_table ipv4_route_table[] = {
2849         {
2850                 .procname       = "gc_thresh",
2851                 .data           = &ipv4_dst_ops.gc_thresh,
2852                 .maxlen         = sizeof(int),
2853                 .mode           = 0644,
2854                 .proc_handler   = proc_dointvec,
2855         },
2856         {
2857                 .procname       = "max_size",
2858                 .data           = &ip_rt_max_size,
2859                 .maxlen         = sizeof(int),
2860                 .mode           = 0644,
2861                 .proc_handler   = proc_dointvec,
2862         },
2863         {
2864                 /*  Deprecated. Use gc_min_interval_ms */
2865
2866                 .procname       = "gc_min_interval",
2867                 .data           = &ip_rt_gc_min_interval,
2868                 .maxlen         = sizeof(int),
2869                 .mode           = 0644,
2870                 .proc_handler   = proc_dointvec_jiffies,
2871         },
2872         {
2873                 .procname       = "gc_min_interval_ms",
2874                 .data           = &ip_rt_gc_min_interval,
2875                 .maxlen         = sizeof(int),
2876                 .mode           = 0644,
2877                 .proc_handler   = proc_dointvec_ms_jiffies,
2878         },
2879         {
2880                 .procname       = "gc_timeout",
2881                 .data           = &ip_rt_gc_timeout,
2882                 .maxlen         = sizeof(int),
2883                 .mode           = 0644,
2884                 .proc_handler   = proc_dointvec_jiffies,
2885         },
2886         {
2887                 .procname       = "gc_interval",
2888                 .data           = &ip_rt_gc_interval,
2889                 .maxlen         = sizeof(int),
2890                 .mode           = 0644,
2891                 .proc_handler   = proc_dointvec_jiffies,
2892         },
2893         {
2894                 .procname       = "redirect_load",
2895                 .data           = &ip_rt_redirect_load,
2896                 .maxlen         = sizeof(int),
2897                 .mode           = 0644,
2898                 .proc_handler   = proc_dointvec,
2899         },
2900         {
2901                 .procname       = "redirect_number",
2902                 .data           = &ip_rt_redirect_number,
2903                 .maxlen         = sizeof(int),
2904                 .mode           = 0644,
2905                 .proc_handler   = proc_dointvec,
2906         },
2907         {
2908                 .procname       = "redirect_silence",
2909                 .data           = &ip_rt_redirect_silence,
2910                 .maxlen         = sizeof(int),
2911                 .mode           = 0644,
2912                 .proc_handler   = proc_dointvec,
2913         },
2914         {
2915                 .procname       = "error_cost",
2916                 .data           = &ip_rt_error_cost,
2917                 .maxlen         = sizeof(int),
2918                 .mode           = 0644,
2919                 .proc_handler   = proc_dointvec,
2920         },
2921         {
2922                 .procname       = "error_burst",
2923                 .data           = &ip_rt_error_burst,
2924                 .maxlen         = sizeof(int),
2925                 .mode           = 0644,
2926                 .proc_handler   = proc_dointvec,
2927         },
2928         {
2929                 .procname       = "gc_elasticity",
2930                 .data           = &ip_rt_gc_elasticity,
2931                 .maxlen         = sizeof(int),
2932                 .mode           = 0644,
2933                 .proc_handler   = proc_dointvec,
2934         },
2935         {
2936                 .procname       = "mtu_expires",
2937                 .data           = &ip_rt_mtu_expires,
2938                 .maxlen         = sizeof(int),
2939                 .mode           = 0644,
2940                 .proc_handler   = proc_dointvec_jiffies,
2941         },
2942         {
2943                 .procname       = "min_pmtu",
2944                 .data           = &ip_rt_min_pmtu,
2945                 .maxlen         = sizeof(int),
2946                 .mode           = 0644,
2947                 .proc_handler   = proc_dointvec_minmax,
2948                 .extra1         = &ip_min_valid_pmtu,
2949         },
2950         {
2951                 .procname       = "min_adv_mss",
2952                 .data           = &ip_rt_min_advmss,
2953                 .maxlen         = sizeof(int),
2954                 .mode           = 0644,
2955                 .proc_handler   = proc_dointvec,
2956         },
2957         { }
2958 };
2959
2960 static struct ctl_table ipv4_route_flush_table[] = {
2961         {
2962                 .procname       = "flush",
2963                 .maxlen         = sizeof(int),
2964                 .mode           = 0200,
2965                 .proc_handler   = ipv4_sysctl_rtcache_flush,
2966         },
2967         { },
2968 };
2969
2970 static __net_init int sysctl_route_net_init(struct net *net)
2971 {
2972         struct ctl_table *tbl;
2973
2974         tbl = ipv4_route_flush_table;
2975         if (!net_eq(net, &init_net)) {
2976                 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2977                 if (!tbl)
2978                         goto err_dup;
2979
2980                 /* Don't export sysctls to unprivileged users */
2981                 if (net->user_ns != &init_user_ns)
2982                         tbl[0].procname = NULL;
2983         }
2984         tbl[0].extra1 = net;
2985
2986         net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2987         if (!net->ipv4.route_hdr)
2988                 goto err_reg;
2989         return 0;
2990
2991 err_reg:
2992         if (tbl != ipv4_route_flush_table)
2993                 kfree(tbl);
2994 err_dup:
2995         return -ENOMEM;
2996 }
2997
2998 static __net_exit void sysctl_route_net_exit(struct net *net)
2999 {
3000         struct ctl_table *tbl;
3001
3002         tbl = net->ipv4.route_hdr->ctl_table_arg;
3003         unregister_net_sysctl_table(net->ipv4.route_hdr);
3004         BUG_ON(tbl == ipv4_route_flush_table);
3005         kfree(tbl);
3006 }
3007
3008 static __net_initdata struct pernet_operations sysctl_route_ops = {
3009         .init = sysctl_route_net_init,
3010         .exit = sysctl_route_net_exit,
3011 };
3012 #endif
3013
3014 static __net_init int rt_genid_init(struct net *net)
3015 {
3016         atomic_set(&net->ipv4.rt_genid, 0);
3017         atomic_set(&net->fnhe_genid, 0);
3018         atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
3019         return 0;
3020 }
3021
3022 static __net_initdata struct pernet_operations rt_genid_ops = {
3023         .init = rt_genid_init,
3024 };
3025
3026 static int __net_init ipv4_inetpeer_init(struct net *net)
3027 {
3028         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3029
3030         if (!bp)
3031                 return -ENOMEM;
3032         inet_peer_base_init(bp);
3033         net->ipv4.peers = bp;
3034         return 0;
3035 }
3036
3037 static void __net_exit ipv4_inetpeer_exit(struct net *net)
3038 {
3039         struct inet_peer_base *bp = net->ipv4.peers;
3040
3041         net->ipv4.peers = NULL;
3042         inetpeer_invalidate_tree(bp);
3043         kfree(bp);
3044 }
3045
3046 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3047         .init   =       ipv4_inetpeer_init,
3048         .exit   =       ipv4_inetpeer_exit,
3049 };
3050
3051 #ifdef CONFIG_IP_ROUTE_CLASSID
3052 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3053 #endif /* CONFIG_IP_ROUTE_CLASSID */
3054
3055 int __init ip_rt_init(void)
3056 {
3057         int cpu;
3058
3059         ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
3060         if (!ip_idents)
3061                 panic("IP: failed to allocate ip_idents\n");
3062
3063         prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
3064
3065         ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
3066         if (!ip_tstamps)
3067                 panic("IP: failed to allocate ip_tstamps\n");
3068
3069         for_each_possible_cpu(cpu) {
3070                 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3071
3072                 INIT_LIST_HEAD(&ul->head);
3073                 spin_lock_init(&ul->lock);
3074         }
3075 #ifdef CONFIG_IP_ROUTE_CLASSID
3076         ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3077         if (!ip_rt_acct)
3078                 panic("IP: failed to allocate ip_rt_acct\n");
3079 #endif
3080
3081         ipv4_dst_ops.kmem_cachep =
3082                 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3083                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3084
3085         ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3086
3087         if (dst_entries_init(&ipv4_dst_ops) < 0)
3088                 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3089
3090         if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3091                 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3092
3093         ipv4_dst_ops.gc_thresh = ~0;
3094         ip_rt_max_size = INT_MAX;
3095
3096         devinet_init();
3097         ip_fib_init();
3098
3099         if (ip_rt_proc_init())
3100                 pr_err("Unable to create route proc files\n");
3101 #ifdef CONFIG_XFRM
3102         xfrm_init();
3103         xfrm4_init();
3104 #endif
3105         rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3106                       RTNL_FLAG_DOIT_UNLOCKED);
3107
3108 #ifdef CONFIG_SYSCTL
3109         register_pernet_subsys(&sysctl_route_ops);
3110 #endif
3111         register_pernet_subsys(&rt_genid_ops);
3112         register_pernet_subsys(&ipv4_inetpeer_ops);
3113         return 0;
3114 }
3115
3116 #ifdef CONFIG_SYSCTL
3117 /*
3118  * We really need to sanitize the damn ipv4 init order, then all
3119  * this nonsense will go away.
3120  */
3121 void __init ip_static_sysctl_init(void)
3122 {
3123         register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3124 }
3125 #endif