| 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 <asm/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/bootmem.h> |
| 74 | #include <linux/string.h> |
| 75 | #include <linux/socket.h> |
| 76 | #include <linux/sockios.h> |
| 77 | #include <linux/errno.h> |
| 78 | #include <linux/in.h> |
| 79 | #include <linux/inet.h> |
| 80 | #include <linux/netdevice.h> |
| 81 | #include <linux/proc_fs.h> |
| 82 | #include <linux/init.h> |
| 83 | #include <linux/workqueue.h> |
| 84 | #include <linux/skbuff.h> |
| 85 | #include <linux/inetdevice.h> |
| 86 | #include <linux/igmp.h> |
| 87 | #include <linux/pkt_sched.h> |
| 88 | #include <linux/mroute.h> |
| 89 | #include <linux/netfilter_ipv4.h> |
| 90 | #include <linux/random.h> |
| 91 | #include <linux/jhash.h> |
| 92 | #include <linux/rcupdate.h> |
| 93 | #include <linux/times.h> |
| 94 | #include <linux/slab.h> |
| 95 | #include <linux/prefetch.h> |
| 96 | #include <net/dst.h> |
| 97 | #include <net/net_namespace.h> |
| 98 | #include <net/protocol.h> |
| 99 | #include <net/ip.h> |
| 100 | #include <net/route.h> |
| 101 | #include <net/inetpeer.h> |
| 102 | #include <net/sock.h> |
| 103 | #include <net/ip_fib.h> |
| 104 | #include <net/arp.h> |
| 105 | #include <net/tcp.h> |
| 106 | #include <net/icmp.h> |
| 107 | #include <net/xfrm.h> |
| 108 | #include <net/netevent.h> |
| 109 | #include <net/rtnetlink.h> |
| 110 | #ifdef CONFIG_SYSCTL |
| 111 | #include <linux/sysctl.h> |
| 112 | #include <linux/kmemleak.h> |
| 113 | #endif |
| 114 | #include <net/secure_seq.h> |
| 115 | |
| 116 | #define RT_FL_TOS(oldflp4) \ |
| 117 | ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) |
| 118 | |
| 119 | #define IP_MAX_MTU 0xFFF0 |
| 120 | |
| 121 | #define RT_GC_TIMEOUT (300*HZ) |
| 122 | |
| 123 | static int ip_rt_max_size; |
| 124 | static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; |
| 125 | static int ip_rt_gc_interval __read_mostly = 60 * HZ; |
| 126 | static int ip_rt_gc_min_interval __read_mostly = HZ / 2; |
| 127 | static int ip_rt_redirect_number __read_mostly = 9; |
| 128 | static int ip_rt_redirect_load __read_mostly = HZ / 50; |
| 129 | static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); |
| 130 | static int ip_rt_error_cost __read_mostly = HZ; |
| 131 | static int ip_rt_error_burst __read_mostly = 5 * HZ; |
| 132 | static int ip_rt_gc_elasticity __read_mostly = 8; |
| 133 | static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; |
| 134 | static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; |
| 135 | static int ip_rt_min_advmss __read_mostly = 256; |
| 136 | |
| 137 | /* |
| 138 | * Interface to generic destination cache. |
| 139 | */ |
| 140 | |
| 141 | static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); |
| 142 | static unsigned int ipv4_default_advmss(const struct dst_entry *dst); |
| 143 | static unsigned int ipv4_mtu(const struct dst_entry *dst); |
| 144 | static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); |
| 145 | static void ipv4_link_failure(struct sk_buff *skb); |
| 146 | static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, |
| 147 | struct sk_buff *skb, u32 mtu); |
| 148 | static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, |
| 149 | struct sk_buff *skb); |
| 150 | |
| 151 | static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, |
| 152 | int how) |
| 153 | { |
| 154 | } |
| 155 | |
| 156 | static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) |
| 157 | { |
| 158 | WARN_ON(1); |
| 159 | return NULL; |
| 160 | } |
| 161 | |
| 162 | static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, |
| 163 | struct sk_buff *skb, |
| 164 | const void *daddr); |
| 165 | |
| 166 | static struct dst_ops ipv4_dst_ops = { |
| 167 | .family = AF_INET, |
| 168 | .protocol = cpu_to_be16(ETH_P_IP), |
| 169 | .check = ipv4_dst_check, |
| 170 | .default_advmss = ipv4_default_advmss, |
| 171 | .mtu = ipv4_mtu, |
| 172 | .cow_metrics = ipv4_cow_metrics, |
| 173 | .ifdown = ipv4_dst_ifdown, |
| 174 | .negative_advice = ipv4_negative_advice, |
| 175 | .link_failure = ipv4_link_failure, |
| 176 | .update_pmtu = ip_rt_update_pmtu, |
| 177 | .redirect = ip_do_redirect, |
| 178 | .local_out = __ip_local_out, |
| 179 | .neigh_lookup = ipv4_neigh_lookup, |
| 180 | }; |
| 181 | |
| 182 | #define ECN_OR_COST(class) TC_PRIO_##class |
| 183 | |
| 184 | const __u8 ip_tos2prio[16] = { |
| 185 | TC_PRIO_BESTEFFORT, |
| 186 | ECN_OR_COST(BESTEFFORT), |
| 187 | TC_PRIO_BESTEFFORT, |
| 188 | ECN_OR_COST(BESTEFFORT), |
| 189 | TC_PRIO_BULK, |
| 190 | ECN_OR_COST(BULK), |
| 191 | TC_PRIO_BULK, |
| 192 | ECN_OR_COST(BULK), |
| 193 | TC_PRIO_INTERACTIVE, |
| 194 | ECN_OR_COST(INTERACTIVE), |
| 195 | TC_PRIO_INTERACTIVE, |
| 196 | ECN_OR_COST(INTERACTIVE), |
| 197 | TC_PRIO_INTERACTIVE_BULK, |
| 198 | ECN_OR_COST(INTERACTIVE_BULK), |
| 199 | TC_PRIO_INTERACTIVE_BULK, |
| 200 | ECN_OR_COST(INTERACTIVE_BULK) |
| 201 | }; |
| 202 | EXPORT_SYMBOL(ip_tos2prio); |
| 203 | |
| 204 | static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); |
| 205 | #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) |
| 206 | |
| 207 | static inline int rt_genid(struct net *net) |
| 208 | { |
| 209 | return atomic_read(&net->ipv4.rt_genid); |
| 210 | } |
| 211 | |
| 212 | #ifdef CONFIG_PROC_FS |
| 213 | static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) |
| 214 | { |
| 215 | if (*pos) |
| 216 | return NULL; |
| 217 | return SEQ_START_TOKEN; |
| 218 | } |
| 219 | |
| 220 | static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| 221 | { |
| 222 | ++*pos; |
| 223 | return NULL; |
| 224 | } |
| 225 | |
| 226 | static void rt_cache_seq_stop(struct seq_file *seq, void *v) |
| 227 | { |
| 228 | } |
| 229 | |
| 230 | static int rt_cache_seq_show(struct seq_file *seq, void *v) |
| 231 | { |
| 232 | if (v == SEQ_START_TOKEN) |
| 233 | seq_printf(seq, "%-127s\n", |
| 234 | "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" |
| 235 | "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" |
| 236 | "HHUptod\tSpecDst"); |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | static const struct seq_operations rt_cache_seq_ops = { |
| 241 | .start = rt_cache_seq_start, |
| 242 | .next = rt_cache_seq_next, |
| 243 | .stop = rt_cache_seq_stop, |
| 244 | .show = rt_cache_seq_show, |
| 245 | }; |
| 246 | |
| 247 | static int rt_cache_seq_open(struct inode *inode, struct file *file) |
| 248 | { |
| 249 | return seq_open(file, &rt_cache_seq_ops); |
| 250 | } |
| 251 | |
| 252 | static const struct file_operations rt_cache_seq_fops = { |
| 253 | .owner = THIS_MODULE, |
| 254 | .open = rt_cache_seq_open, |
| 255 | .read = seq_read, |
| 256 | .llseek = seq_lseek, |
| 257 | .release = seq_release, |
| 258 | }; |
| 259 | |
| 260 | |
| 261 | static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) |
| 262 | { |
| 263 | int cpu; |
| 264 | |
| 265 | if (*pos == 0) |
| 266 | return SEQ_START_TOKEN; |
| 267 | |
| 268 | for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { |
| 269 | if (!cpu_possible(cpu)) |
| 270 | continue; |
| 271 | *pos = cpu+1; |
| 272 | return &per_cpu(rt_cache_stat, cpu); |
| 273 | } |
| 274 | return NULL; |
| 275 | } |
| 276 | |
| 277 | static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| 278 | { |
| 279 | int cpu; |
| 280 | |
| 281 | for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { |
| 282 | if (!cpu_possible(cpu)) |
| 283 | continue; |
| 284 | *pos = cpu+1; |
| 285 | return &per_cpu(rt_cache_stat, cpu); |
| 286 | } |
| 287 | return NULL; |
| 288 | |
| 289 | } |
| 290 | |
| 291 | static void rt_cpu_seq_stop(struct seq_file *seq, void *v) |
| 292 | { |
| 293 | |
| 294 | } |
| 295 | |
| 296 | static int rt_cpu_seq_show(struct seq_file *seq, void *v) |
| 297 | { |
| 298 | struct rt_cache_stat *st = v; |
| 299 | |
| 300 | if (v == SEQ_START_TOKEN) { |
| 301 | 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"); |
| 302 | return 0; |
| 303 | } |
| 304 | |
| 305 | seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " |
| 306 | " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", |
| 307 | dst_entries_get_slow(&ipv4_dst_ops), |
| 308 | st->in_hit, |
| 309 | st->in_slow_tot, |
| 310 | st->in_slow_mc, |
| 311 | st->in_no_route, |
| 312 | st->in_brd, |
| 313 | st->in_martian_dst, |
| 314 | st->in_martian_src, |
| 315 | |
| 316 | st->out_hit, |
| 317 | st->out_slow_tot, |
| 318 | st->out_slow_mc, |
| 319 | |
| 320 | st->gc_total, |
| 321 | st->gc_ignored, |
| 322 | st->gc_goal_miss, |
| 323 | st->gc_dst_overflow, |
| 324 | st->in_hlist_search, |
| 325 | st->out_hlist_search |
| 326 | ); |
| 327 | return 0; |
| 328 | } |
| 329 | |
| 330 | static const struct seq_operations rt_cpu_seq_ops = { |
| 331 | .start = rt_cpu_seq_start, |
| 332 | .next = rt_cpu_seq_next, |
| 333 | .stop = rt_cpu_seq_stop, |
| 334 | .show = rt_cpu_seq_show, |
| 335 | }; |
| 336 | |
| 337 | |
| 338 | static int rt_cpu_seq_open(struct inode *inode, struct file *file) |
| 339 | { |
| 340 | return seq_open(file, &rt_cpu_seq_ops); |
| 341 | } |
| 342 | |
| 343 | static const struct file_operations rt_cpu_seq_fops = { |
| 344 | .owner = THIS_MODULE, |
| 345 | .open = rt_cpu_seq_open, |
| 346 | .read = seq_read, |
| 347 | .llseek = seq_lseek, |
| 348 | .release = seq_release, |
| 349 | }; |
| 350 | |
| 351 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 352 | static int rt_acct_proc_show(struct seq_file *m, void *v) |
| 353 | { |
| 354 | struct ip_rt_acct *dst, *src; |
| 355 | unsigned int i, j; |
| 356 | |
| 357 | dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); |
| 358 | if (!dst) |
| 359 | return -ENOMEM; |
| 360 | |
| 361 | for_each_possible_cpu(i) { |
| 362 | src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); |
| 363 | for (j = 0; j < 256; j++) { |
| 364 | dst[j].o_bytes += src[j].o_bytes; |
| 365 | dst[j].o_packets += src[j].o_packets; |
| 366 | dst[j].i_bytes += src[j].i_bytes; |
| 367 | dst[j].i_packets += src[j].i_packets; |
| 368 | } |
| 369 | } |
| 370 | |
| 371 | seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); |
| 372 | kfree(dst); |
| 373 | return 0; |
| 374 | } |
| 375 | |
| 376 | static int rt_acct_proc_open(struct inode *inode, struct file *file) |
| 377 | { |
| 378 | return single_open(file, rt_acct_proc_show, NULL); |
| 379 | } |
| 380 | |
| 381 | static const struct file_operations rt_acct_proc_fops = { |
| 382 | .owner = THIS_MODULE, |
| 383 | .open = rt_acct_proc_open, |
| 384 | .read = seq_read, |
| 385 | .llseek = seq_lseek, |
| 386 | .release = single_release, |
| 387 | }; |
| 388 | #endif |
| 389 | |
| 390 | static int __net_init ip_rt_do_proc_init(struct net *net) |
| 391 | { |
| 392 | struct proc_dir_entry *pde; |
| 393 | |
| 394 | pde = proc_net_fops_create(net, "rt_cache", S_IRUGO, |
| 395 | &rt_cache_seq_fops); |
| 396 | if (!pde) |
| 397 | goto err1; |
| 398 | |
| 399 | pde = proc_create("rt_cache", S_IRUGO, |
| 400 | net->proc_net_stat, &rt_cpu_seq_fops); |
| 401 | if (!pde) |
| 402 | goto err2; |
| 403 | |
| 404 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 405 | pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); |
| 406 | if (!pde) |
| 407 | goto err3; |
| 408 | #endif |
| 409 | return 0; |
| 410 | |
| 411 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 412 | err3: |
| 413 | remove_proc_entry("rt_cache", net->proc_net_stat); |
| 414 | #endif |
| 415 | err2: |
| 416 | remove_proc_entry("rt_cache", net->proc_net); |
| 417 | err1: |
| 418 | return -ENOMEM; |
| 419 | } |
| 420 | |
| 421 | static void __net_exit ip_rt_do_proc_exit(struct net *net) |
| 422 | { |
| 423 | remove_proc_entry("rt_cache", net->proc_net_stat); |
| 424 | remove_proc_entry("rt_cache", net->proc_net); |
| 425 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 426 | remove_proc_entry("rt_acct", net->proc_net); |
| 427 | #endif |
| 428 | } |
| 429 | |
| 430 | static struct pernet_operations ip_rt_proc_ops __net_initdata = { |
| 431 | .init = ip_rt_do_proc_init, |
| 432 | .exit = ip_rt_do_proc_exit, |
| 433 | }; |
| 434 | |
| 435 | static int __init ip_rt_proc_init(void) |
| 436 | { |
| 437 | return register_pernet_subsys(&ip_rt_proc_ops); |
| 438 | } |
| 439 | |
| 440 | #else |
| 441 | static inline int ip_rt_proc_init(void) |
| 442 | { |
| 443 | return 0; |
| 444 | } |
| 445 | #endif /* CONFIG_PROC_FS */ |
| 446 | |
| 447 | static inline int rt_is_expired(struct rtable *rth) |
| 448 | { |
| 449 | return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); |
| 450 | } |
| 451 | |
| 452 | /* |
| 453 | * Perturbation of rt_genid by a small quantity [1..256] |
| 454 | * Using 8 bits of shuffling ensure we can call rt_cache_invalidate() |
| 455 | * many times (2^24) without giving recent rt_genid. |
| 456 | * Jenkins hash is strong enough that litle changes of rt_genid are OK. |
| 457 | */ |
| 458 | static void rt_cache_invalidate(struct net *net) |
| 459 | { |
| 460 | unsigned char shuffle; |
| 461 | |
| 462 | get_random_bytes(&shuffle, sizeof(shuffle)); |
| 463 | atomic_add(shuffle + 1U, &net->ipv4.rt_genid); |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | * delay < 0 : invalidate cache (fast : entries will be deleted later) |
| 468 | * delay >= 0 : invalidate & flush cache (can be long) |
| 469 | */ |
| 470 | void rt_cache_flush(struct net *net, int delay) |
| 471 | { |
| 472 | rt_cache_invalidate(net); |
| 473 | } |
| 474 | |
| 475 | static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, |
| 476 | struct sk_buff *skb, |
| 477 | const void *daddr) |
| 478 | { |
| 479 | struct net_device *dev = dst->dev; |
| 480 | const __be32 *pkey = daddr; |
| 481 | const struct rtable *rt; |
| 482 | struct neighbour *n; |
| 483 | |
| 484 | rt = (const struct rtable *) dst; |
| 485 | if (rt->rt_gateway) |
| 486 | pkey = (const __be32 *) &rt->rt_gateway; |
| 487 | else if (skb) |
| 488 | pkey = &ip_hdr(skb)->daddr; |
| 489 | |
| 490 | n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); |
| 491 | if (n) |
| 492 | return n; |
| 493 | return neigh_create(&arp_tbl, pkey, dev); |
| 494 | } |
| 495 | |
| 496 | /* |
| 497 | * Peer allocation may fail only in serious out-of-memory conditions. However |
| 498 | * we still can generate some output. |
| 499 | * Random ID selection looks a bit dangerous because we have no chances to |
| 500 | * select ID being unique in a reasonable period of time. |
| 501 | * But broken packet identifier may be better than no packet at all. |
| 502 | */ |
| 503 | static void ip_select_fb_ident(struct iphdr *iph) |
| 504 | { |
| 505 | static DEFINE_SPINLOCK(ip_fb_id_lock); |
| 506 | static u32 ip_fallback_id; |
| 507 | u32 salt; |
| 508 | |
| 509 | spin_lock_bh(&ip_fb_id_lock); |
| 510 | salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr); |
| 511 | iph->id = htons(salt & 0xFFFF); |
| 512 | ip_fallback_id = salt; |
| 513 | spin_unlock_bh(&ip_fb_id_lock); |
| 514 | } |
| 515 | |
| 516 | void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more) |
| 517 | { |
| 518 | struct net *net = dev_net(dst->dev); |
| 519 | struct inet_peer *peer; |
| 520 | |
| 521 | peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1); |
| 522 | if (peer) { |
| 523 | iph->id = htons(inet_getid(peer, more)); |
| 524 | inet_putpeer(peer); |
| 525 | return; |
| 526 | } |
| 527 | |
| 528 | ip_select_fb_ident(iph); |
| 529 | } |
| 530 | EXPORT_SYMBOL(__ip_select_ident); |
| 531 | |
| 532 | static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk, |
| 533 | const struct iphdr *iph, |
| 534 | int oif, u8 tos, |
| 535 | u8 prot, u32 mark, int flow_flags) |
| 536 | { |
| 537 | if (sk) { |
| 538 | const struct inet_sock *inet = inet_sk(sk); |
| 539 | |
| 540 | oif = sk->sk_bound_dev_if; |
| 541 | mark = sk->sk_mark; |
| 542 | tos = RT_CONN_FLAGS(sk); |
| 543 | prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; |
| 544 | } |
| 545 | flowi4_init_output(fl4, oif, mark, tos, |
| 546 | RT_SCOPE_UNIVERSE, prot, |
| 547 | flow_flags, |
| 548 | iph->daddr, iph->saddr, 0, 0); |
| 549 | } |
| 550 | |
| 551 | static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, |
| 552 | const struct sock *sk) |
| 553 | { |
| 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(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); |
| 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_SEQLOCK(fnhe_seqlock); |
| 591 | |
| 592 | static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) |
| 593 | { |
| 594 | struct fib_nh_exception *fnhe, *oldest; |
| 595 | |
| 596 | oldest = rcu_dereference(hash->chain); |
| 597 | for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; |
| 598 | fnhe = rcu_dereference(fnhe->fnhe_next)) { |
| 599 | if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) |
| 600 | oldest = fnhe; |
| 601 | } |
| 602 | return oldest; |
| 603 | } |
| 604 | |
| 605 | static inline u32 fnhe_hashfun(__be32 daddr) |
| 606 | { |
| 607 | u32 hval; |
| 608 | |
| 609 | hval = (__force u32) daddr; |
| 610 | hval ^= (hval >> 11) ^ (hval >> 22); |
| 611 | |
| 612 | return hval & (FNHE_HASH_SIZE - 1); |
| 613 | } |
| 614 | |
| 615 | static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, |
| 616 | u32 pmtu, unsigned long expires) |
| 617 | { |
| 618 | struct fnhe_hash_bucket *hash; |
| 619 | struct fib_nh_exception *fnhe; |
| 620 | int depth; |
| 621 | u32 hval = fnhe_hashfun(daddr); |
| 622 | |
| 623 | write_seqlock_bh(&fnhe_seqlock); |
| 624 | |
| 625 | hash = nh->nh_exceptions; |
| 626 | if (!hash) { |
| 627 | hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC); |
| 628 | if (!hash) |
| 629 | goto out_unlock; |
| 630 | nh->nh_exceptions = hash; |
| 631 | } |
| 632 | |
| 633 | hash += hval; |
| 634 | |
| 635 | depth = 0; |
| 636 | for (fnhe = rcu_dereference(hash->chain); fnhe; |
| 637 | fnhe = rcu_dereference(fnhe->fnhe_next)) { |
| 638 | if (fnhe->fnhe_daddr == daddr) |
| 639 | break; |
| 640 | depth++; |
| 641 | } |
| 642 | |
| 643 | if (fnhe) { |
| 644 | if (gw) |
| 645 | fnhe->fnhe_gw = gw; |
| 646 | if (pmtu) { |
| 647 | fnhe->fnhe_pmtu = pmtu; |
| 648 | fnhe->fnhe_expires = expires; |
| 649 | } |
| 650 | } else { |
| 651 | if (depth > FNHE_RECLAIM_DEPTH) |
| 652 | fnhe = fnhe_oldest(hash); |
| 653 | else { |
| 654 | fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); |
| 655 | if (!fnhe) |
| 656 | goto out_unlock; |
| 657 | |
| 658 | fnhe->fnhe_next = hash->chain; |
| 659 | rcu_assign_pointer(hash->chain, fnhe); |
| 660 | } |
| 661 | fnhe->fnhe_daddr = daddr; |
| 662 | fnhe->fnhe_gw = gw; |
| 663 | fnhe->fnhe_pmtu = pmtu; |
| 664 | fnhe->fnhe_expires = expires; |
| 665 | } |
| 666 | |
| 667 | fnhe->fnhe_stamp = jiffies; |
| 668 | |
| 669 | out_unlock: |
| 670 | write_sequnlock_bh(&fnhe_seqlock); |
| 671 | return; |
| 672 | } |
| 673 | |
| 674 | static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, |
| 675 | bool kill_route) |
| 676 | { |
| 677 | __be32 new_gw = icmp_hdr(skb)->un.gateway; |
| 678 | __be32 old_gw = ip_hdr(skb)->saddr; |
| 679 | struct net_device *dev = skb->dev; |
| 680 | struct in_device *in_dev; |
| 681 | struct fib_result res; |
| 682 | struct neighbour *n; |
| 683 | struct net *net; |
| 684 | |
| 685 | switch (icmp_hdr(skb)->code & 7) { |
| 686 | case ICMP_REDIR_NET: |
| 687 | case ICMP_REDIR_NETTOS: |
| 688 | case ICMP_REDIR_HOST: |
| 689 | case ICMP_REDIR_HOSTTOS: |
| 690 | break; |
| 691 | |
| 692 | default: |
| 693 | return; |
| 694 | } |
| 695 | |
| 696 | if (rt->rt_gateway != old_gw) |
| 697 | return; |
| 698 | |
| 699 | in_dev = __in_dev_get_rcu(dev); |
| 700 | if (!in_dev) |
| 701 | return; |
| 702 | |
| 703 | net = dev_net(dev); |
| 704 | if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || |
| 705 | ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || |
| 706 | ipv4_is_zeronet(new_gw)) |
| 707 | goto reject_redirect; |
| 708 | |
| 709 | if (!IN_DEV_SHARED_MEDIA(in_dev)) { |
| 710 | if (!inet_addr_onlink(in_dev, new_gw, old_gw)) |
| 711 | goto reject_redirect; |
| 712 | if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) |
| 713 | goto reject_redirect; |
| 714 | } else { |
| 715 | if (inet_addr_type(net, new_gw) != RTN_UNICAST) |
| 716 | goto reject_redirect; |
| 717 | } |
| 718 | |
| 719 | n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw); |
| 720 | if (n) { |
| 721 | if (!(n->nud_state & NUD_VALID)) { |
| 722 | neigh_event_send(n, NULL); |
| 723 | } else { |
| 724 | if (fib_lookup(net, fl4, &res) == 0) { |
| 725 | struct fib_nh *nh = &FIB_RES_NH(res); |
| 726 | |
| 727 | update_or_create_fnhe(nh, fl4->daddr, new_gw, |
| 728 | 0, 0); |
| 729 | } |
| 730 | if (kill_route) |
| 731 | rt->dst.obsolete = DST_OBSOLETE_KILL; |
| 732 | call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); |
| 733 | } |
| 734 | neigh_release(n); |
| 735 | } |
| 736 | return; |
| 737 | |
| 738 | reject_redirect: |
| 739 | #ifdef CONFIG_IP_ROUTE_VERBOSE |
| 740 | if (IN_DEV_LOG_MARTIANS(in_dev)) { |
| 741 | const struct iphdr *iph = (const struct iphdr *) skb->data; |
| 742 | __be32 daddr = iph->daddr; |
| 743 | __be32 saddr = iph->saddr; |
| 744 | |
| 745 | net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" |
| 746 | " Advised path = %pI4 -> %pI4\n", |
| 747 | &old_gw, dev->name, &new_gw, |
| 748 | &saddr, &daddr); |
| 749 | } |
| 750 | #endif |
| 751 | ; |
| 752 | } |
| 753 | |
| 754 | static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) |
| 755 | { |
| 756 | struct rtable *rt; |
| 757 | struct flowi4 fl4; |
| 758 | |
| 759 | rt = (struct rtable *) dst; |
| 760 | |
| 761 | ip_rt_build_flow_key(&fl4, sk, skb); |
| 762 | __ip_do_redirect(rt, skb, &fl4, true); |
| 763 | } |
| 764 | |
| 765 | static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) |
| 766 | { |
| 767 | struct rtable *rt = (struct rtable *)dst; |
| 768 | struct dst_entry *ret = dst; |
| 769 | |
| 770 | if (rt) { |
| 771 | if (dst->obsolete > 0) { |
| 772 | ip_rt_put(rt); |
| 773 | ret = NULL; |
| 774 | } else if ((rt->rt_flags & RTCF_REDIRECTED) || |
| 775 | rt->dst.expires) { |
| 776 | ip_rt_put(rt); |
| 777 | ret = NULL; |
| 778 | } |
| 779 | } |
| 780 | return ret; |
| 781 | } |
| 782 | |
| 783 | /* |
| 784 | * Algorithm: |
| 785 | * 1. The first ip_rt_redirect_number redirects are sent |
| 786 | * with exponential backoff, then we stop sending them at all, |
| 787 | * assuming that the host ignores our redirects. |
| 788 | * 2. If we did not see packets requiring redirects |
| 789 | * during ip_rt_redirect_silence, we assume that the host |
| 790 | * forgot redirected route and start to send redirects again. |
| 791 | * |
| 792 | * This algorithm is much cheaper and more intelligent than dumb load limiting |
| 793 | * in icmp.c. |
| 794 | * |
| 795 | * NOTE. Do not forget to inhibit load limiting for redirects (redundant) |
| 796 | * and "frag. need" (breaks PMTU discovery) in icmp.c. |
| 797 | */ |
| 798 | |
| 799 | void ip_rt_send_redirect(struct sk_buff *skb) |
| 800 | { |
| 801 | struct rtable *rt = skb_rtable(skb); |
| 802 | struct in_device *in_dev; |
| 803 | struct inet_peer *peer; |
| 804 | struct net *net; |
| 805 | int log_martians; |
| 806 | |
| 807 | rcu_read_lock(); |
| 808 | in_dev = __in_dev_get_rcu(rt->dst.dev); |
| 809 | if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { |
| 810 | rcu_read_unlock(); |
| 811 | return; |
| 812 | } |
| 813 | log_martians = IN_DEV_LOG_MARTIANS(in_dev); |
| 814 | rcu_read_unlock(); |
| 815 | |
| 816 | net = dev_net(rt->dst.dev); |
| 817 | peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); |
| 818 | if (!peer) { |
| 819 | icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); |
| 820 | return; |
| 821 | } |
| 822 | |
| 823 | /* No redirected packets during ip_rt_redirect_silence; |
| 824 | * reset the algorithm. |
| 825 | */ |
| 826 | if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) |
| 827 | peer->rate_tokens = 0; |
| 828 | |
| 829 | /* Too many ignored redirects; do not send anything |
| 830 | * set dst.rate_last to the last seen redirected packet. |
| 831 | */ |
| 832 | if (peer->rate_tokens >= ip_rt_redirect_number) { |
| 833 | peer->rate_last = jiffies; |
| 834 | goto out_put_peer; |
| 835 | } |
| 836 | |
| 837 | /* Check for load limit; set rate_last to the latest sent |
| 838 | * redirect. |
| 839 | */ |
| 840 | if (peer->rate_tokens == 0 || |
| 841 | time_after(jiffies, |
| 842 | (peer->rate_last + |
| 843 | (ip_rt_redirect_load << peer->rate_tokens)))) { |
| 844 | icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); |
| 845 | peer->rate_last = jiffies; |
| 846 | ++peer->rate_tokens; |
| 847 | #ifdef CONFIG_IP_ROUTE_VERBOSE |
| 848 | if (log_martians && |
| 849 | peer->rate_tokens == ip_rt_redirect_number) |
| 850 | net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", |
| 851 | &ip_hdr(skb)->saddr, rt->rt_iif, |
| 852 | &ip_hdr(skb)->daddr, &rt->rt_gateway); |
| 853 | #endif |
| 854 | } |
| 855 | out_put_peer: |
| 856 | inet_putpeer(peer); |
| 857 | } |
| 858 | |
| 859 | static int ip_error(struct sk_buff *skb) |
| 860 | { |
| 861 | struct in_device *in_dev = __in_dev_get_rcu(skb->dev); |
| 862 | struct rtable *rt = skb_rtable(skb); |
| 863 | struct inet_peer *peer; |
| 864 | unsigned long now; |
| 865 | struct net *net; |
| 866 | bool send; |
| 867 | int code; |
| 868 | |
| 869 | net = dev_net(rt->dst.dev); |
| 870 | if (!IN_DEV_FORWARD(in_dev)) { |
| 871 | switch (rt->dst.error) { |
| 872 | case EHOSTUNREACH: |
| 873 | IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS); |
| 874 | break; |
| 875 | |
| 876 | case ENETUNREACH: |
| 877 | IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); |
| 878 | break; |
| 879 | } |
| 880 | goto out; |
| 881 | } |
| 882 | |
| 883 | switch (rt->dst.error) { |
| 884 | case EINVAL: |
| 885 | default: |
| 886 | goto out; |
| 887 | case EHOSTUNREACH: |
| 888 | code = ICMP_HOST_UNREACH; |
| 889 | break; |
| 890 | case ENETUNREACH: |
| 891 | code = ICMP_NET_UNREACH; |
| 892 | IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); |
| 893 | break; |
| 894 | case EACCES: |
| 895 | code = ICMP_PKT_FILTERED; |
| 896 | break; |
| 897 | } |
| 898 | |
| 899 | peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); |
| 900 | |
| 901 | send = true; |
| 902 | if (peer) { |
| 903 | now = jiffies; |
| 904 | peer->rate_tokens += now - peer->rate_last; |
| 905 | if (peer->rate_tokens > ip_rt_error_burst) |
| 906 | peer->rate_tokens = ip_rt_error_burst; |
| 907 | peer->rate_last = now; |
| 908 | if (peer->rate_tokens >= ip_rt_error_cost) |
| 909 | peer->rate_tokens -= ip_rt_error_cost; |
| 910 | else |
| 911 | send = false; |
| 912 | inet_putpeer(peer); |
| 913 | } |
| 914 | if (send) |
| 915 | icmp_send(skb, ICMP_DEST_UNREACH, code, 0); |
| 916 | |
| 917 | out: kfree_skb(skb); |
| 918 | return 0; |
| 919 | } |
| 920 | |
| 921 | static u32 __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) |
| 922 | { |
| 923 | struct fib_result res; |
| 924 | |
| 925 | if (mtu < ip_rt_min_pmtu) |
| 926 | mtu = ip_rt_min_pmtu; |
| 927 | |
| 928 | if (fib_lookup(dev_net(rt->dst.dev), fl4, &res) == 0) { |
| 929 | struct fib_nh *nh = &FIB_RES_NH(res); |
| 930 | |
| 931 | update_or_create_fnhe(nh, fl4->daddr, 0, mtu, |
| 932 | jiffies + ip_rt_mtu_expires); |
| 933 | } |
| 934 | return mtu; |
| 935 | } |
| 936 | |
| 937 | static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, |
| 938 | struct sk_buff *skb, u32 mtu) |
| 939 | { |
| 940 | struct rtable *rt = (struct rtable *) dst; |
| 941 | struct flowi4 fl4; |
| 942 | |
| 943 | ip_rt_build_flow_key(&fl4, sk, skb); |
| 944 | mtu = __ip_rt_update_pmtu(rt, &fl4, mtu); |
| 945 | |
| 946 | if (!rt->rt_pmtu) { |
| 947 | dst->obsolete = DST_OBSOLETE_KILL; |
| 948 | } else { |
| 949 | rt->rt_pmtu = mtu; |
| 950 | dst_set_expires(&rt->dst, ip_rt_mtu_expires); |
| 951 | } |
| 952 | } |
| 953 | |
| 954 | void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, |
| 955 | int oif, u32 mark, u8 protocol, int flow_flags) |
| 956 | { |
| 957 | const struct iphdr *iph = (const struct iphdr *) skb->data; |
| 958 | struct flowi4 fl4; |
| 959 | struct rtable *rt; |
| 960 | |
| 961 | __build_flow_key(&fl4, NULL, iph, oif, |
| 962 | RT_TOS(iph->tos), protocol, mark, flow_flags); |
| 963 | rt = __ip_route_output_key(net, &fl4); |
| 964 | if (!IS_ERR(rt)) { |
| 965 | __ip_rt_update_pmtu(rt, &fl4, mtu); |
| 966 | ip_rt_put(rt); |
| 967 | } |
| 968 | } |
| 969 | EXPORT_SYMBOL_GPL(ipv4_update_pmtu); |
| 970 | |
| 971 | void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) |
| 972 | { |
| 973 | const struct iphdr *iph = (const struct iphdr *) skb->data; |
| 974 | struct flowi4 fl4; |
| 975 | struct rtable *rt; |
| 976 | |
| 977 | __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); |
| 978 | rt = __ip_route_output_key(sock_net(sk), &fl4); |
| 979 | if (!IS_ERR(rt)) { |
| 980 | __ip_rt_update_pmtu(rt, &fl4, mtu); |
| 981 | ip_rt_put(rt); |
| 982 | } |
| 983 | } |
| 984 | EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); |
| 985 | |
| 986 | void ipv4_redirect(struct sk_buff *skb, struct net *net, |
| 987 | int oif, u32 mark, u8 protocol, int flow_flags) |
| 988 | { |
| 989 | const struct iphdr *iph = (const struct iphdr *) skb->data; |
| 990 | struct flowi4 fl4; |
| 991 | struct rtable *rt; |
| 992 | |
| 993 | __build_flow_key(&fl4, NULL, iph, oif, |
| 994 | RT_TOS(iph->tos), protocol, mark, flow_flags); |
| 995 | rt = __ip_route_output_key(net, &fl4); |
| 996 | if (!IS_ERR(rt)) { |
| 997 | __ip_do_redirect(rt, skb, &fl4, false); |
| 998 | ip_rt_put(rt); |
| 999 | } |
| 1000 | } |
| 1001 | EXPORT_SYMBOL_GPL(ipv4_redirect); |
| 1002 | |
| 1003 | void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) |
| 1004 | { |
| 1005 | const struct iphdr *iph = (const struct iphdr *) skb->data; |
| 1006 | struct flowi4 fl4; |
| 1007 | struct rtable *rt; |
| 1008 | |
| 1009 | __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); |
| 1010 | rt = __ip_route_output_key(sock_net(sk), &fl4); |
| 1011 | if (!IS_ERR(rt)) { |
| 1012 | __ip_do_redirect(rt, skb, &fl4, false); |
| 1013 | ip_rt_put(rt); |
| 1014 | } |
| 1015 | } |
| 1016 | EXPORT_SYMBOL_GPL(ipv4_sk_redirect); |
| 1017 | |
| 1018 | static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) |
| 1019 | { |
| 1020 | struct rtable *rt = (struct rtable *) dst; |
| 1021 | |
| 1022 | /* All IPV4 dsts are created with ->obsolete set to the value |
| 1023 | * DST_OBSOLETE_FORCE_CHK which forces validation calls down |
| 1024 | * into this function always. |
| 1025 | * |
| 1026 | * When a PMTU/redirect information update invalidates a |
| 1027 | * route, this is indicated by setting obsolete to |
| 1028 | * DST_OBSOLETE_KILL. |
| 1029 | */ |
| 1030 | if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt)) |
| 1031 | return NULL; |
| 1032 | return dst; |
| 1033 | } |
| 1034 | |
| 1035 | static void ipv4_link_failure(struct sk_buff *skb) |
| 1036 | { |
| 1037 | struct rtable *rt; |
| 1038 | |
| 1039 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); |
| 1040 | |
| 1041 | rt = skb_rtable(skb); |
| 1042 | if (rt) |
| 1043 | dst_set_expires(&rt->dst, 0); |
| 1044 | } |
| 1045 | |
| 1046 | static int ip_rt_bug(struct sk_buff *skb) |
| 1047 | { |
| 1048 | pr_debug("%s: %pI4 -> %pI4, %s\n", |
| 1049 | __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, |
| 1050 | skb->dev ? skb->dev->name : "?"); |
| 1051 | kfree_skb(skb); |
| 1052 | WARN_ON(1); |
| 1053 | return 0; |
| 1054 | } |
| 1055 | |
| 1056 | /* |
| 1057 | We do not cache source address of outgoing interface, |
| 1058 | because it is used only by IP RR, TS and SRR options, |
| 1059 | so that it out of fast path. |
| 1060 | |
| 1061 | BTW remember: "addr" is allowed to be not aligned |
| 1062 | in IP options! |
| 1063 | */ |
| 1064 | |
| 1065 | void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) |
| 1066 | { |
| 1067 | __be32 src; |
| 1068 | |
| 1069 | if (rt_is_output_route(rt)) |
| 1070 | src = ip_hdr(skb)->saddr; |
| 1071 | else { |
| 1072 | struct fib_result res; |
| 1073 | struct flowi4 fl4; |
| 1074 | struct iphdr *iph; |
| 1075 | |
| 1076 | iph = ip_hdr(skb); |
| 1077 | |
| 1078 | memset(&fl4, 0, sizeof(fl4)); |
| 1079 | fl4.daddr = iph->daddr; |
| 1080 | fl4.saddr = iph->saddr; |
| 1081 | fl4.flowi4_tos = RT_TOS(iph->tos); |
| 1082 | fl4.flowi4_oif = rt->dst.dev->ifindex; |
| 1083 | fl4.flowi4_iif = skb->dev->ifindex; |
| 1084 | fl4.flowi4_mark = skb->mark; |
| 1085 | |
| 1086 | rcu_read_lock(); |
| 1087 | if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) |
| 1088 | src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); |
| 1089 | else |
| 1090 | src = inet_select_addr(rt->dst.dev, |
| 1091 | rt_nexthop(rt, iph->daddr), |
| 1092 | RT_SCOPE_UNIVERSE); |
| 1093 | rcu_read_unlock(); |
| 1094 | } |
| 1095 | memcpy(addr, &src, 4); |
| 1096 | } |
| 1097 | |
| 1098 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 1099 | static void set_class_tag(struct rtable *rt, u32 tag) |
| 1100 | { |
| 1101 | if (!(rt->dst.tclassid & 0xFFFF)) |
| 1102 | rt->dst.tclassid |= tag & 0xFFFF; |
| 1103 | if (!(rt->dst.tclassid & 0xFFFF0000)) |
| 1104 | rt->dst.tclassid |= tag & 0xFFFF0000; |
| 1105 | } |
| 1106 | #endif |
| 1107 | |
| 1108 | static unsigned int ipv4_default_advmss(const struct dst_entry *dst) |
| 1109 | { |
| 1110 | unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); |
| 1111 | |
| 1112 | if (advmss == 0) { |
| 1113 | advmss = max_t(unsigned int, dst->dev->mtu - 40, |
| 1114 | ip_rt_min_advmss); |
| 1115 | if (advmss > 65535 - 40) |
| 1116 | advmss = 65535 - 40; |
| 1117 | } |
| 1118 | return advmss; |
| 1119 | } |
| 1120 | |
| 1121 | static unsigned int ipv4_mtu(const struct dst_entry *dst) |
| 1122 | { |
| 1123 | const struct rtable *rt = (const struct rtable *) dst; |
| 1124 | unsigned int mtu = rt->rt_pmtu; |
| 1125 | |
| 1126 | if (mtu && time_after_eq(jiffies, rt->dst.expires)) |
| 1127 | mtu = 0; |
| 1128 | |
| 1129 | if (!mtu) |
| 1130 | mtu = dst_metric_raw(dst, RTAX_MTU); |
| 1131 | |
| 1132 | if (mtu && rt_is_output_route(rt)) |
| 1133 | return mtu; |
| 1134 | |
| 1135 | mtu = dst->dev->mtu; |
| 1136 | |
| 1137 | if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { |
| 1138 | if (rt->rt_gateway && mtu > 576) |
| 1139 | mtu = 576; |
| 1140 | } |
| 1141 | |
| 1142 | if (mtu > IP_MAX_MTU) |
| 1143 | mtu = IP_MAX_MTU; |
| 1144 | |
| 1145 | return mtu; |
| 1146 | } |
| 1147 | |
| 1148 | static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) |
| 1149 | { |
| 1150 | struct fnhe_hash_bucket *hash = nh->nh_exceptions; |
| 1151 | struct fib_nh_exception *fnhe; |
| 1152 | u32 hval; |
| 1153 | |
| 1154 | if (!hash) |
| 1155 | return NULL; |
| 1156 | |
| 1157 | hval = fnhe_hashfun(daddr); |
| 1158 | |
| 1159 | for (fnhe = rcu_dereference(hash[hval].chain); fnhe; |
| 1160 | fnhe = rcu_dereference(fnhe->fnhe_next)) { |
| 1161 | if (fnhe->fnhe_daddr == daddr) |
| 1162 | return fnhe; |
| 1163 | } |
| 1164 | return NULL; |
| 1165 | } |
| 1166 | |
| 1167 | static void rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, |
| 1168 | __be32 daddr) |
| 1169 | { |
| 1170 | __be32 fnhe_daddr, gw; |
| 1171 | unsigned long expires; |
| 1172 | unsigned int seq; |
| 1173 | u32 pmtu; |
| 1174 | |
| 1175 | restart: |
| 1176 | seq = read_seqbegin(&fnhe_seqlock); |
| 1177 | fnhe_daddr = fnhe->fnhe_daddr; |
| 1178 | gw = fnhe->fnhe_gw; |
| 1179 | pmtu = fnhe->fnhe_pmtu; |
| 1180 | expires = fnhe->fnhe_expires; |
| 1181 | if (read_seqretry(&fnhe_seqlock, seq)) |
| 1182 | goto restart; |
| 1183 | |
| 1184 | if (daddr != fnhe_daddr) |
| 1185 | return; |
| 1186 | |
| 1187 | if (pmtu) { |
| 1188 | unsigned long diff = expires - jiffies; |
| 1189 | |
| 1190 | if (time_before(jiffies, expires)) { |
| 1191 | rt->rt_pmtu = pmtu; |
| 1192 | dst_set_expires(&rt->dst, diff); |
| 1193 | } |
| 1194 | } |
| 1195 | if (gw) { |
| 1196 | rt->rt_flags |= RTCF_REDIRECTED; |
| 1197 | rt->rt_gateway = gw; |
| 1198 | } |
| 1199 | fnhe->fnhe_stamp = jiffies; |
| 1200 | } |
| 1201 | |
| 1202 | static inline void rt_release_rcu(struct rcu_head *head) |
| 1203 | { |
| 1204 | struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); |
| 1205 | dst_release(dst); |
| 1206 | } |
| 1207 | |
| 1208 | static void rt_cache_route(struct fib_nh *nh, struct rtable *rt) |
| 1209 | { |
| 1210 | struct rtable *orig, *prev, **p = &nh->nh_rth_output; |
| 1211 | |
| 1212 | if (rt_is_input_route(rt)) |
| 1213 | p = &nh->nh_rth_input; |
| 1214 | |
| 1215 | orig = *p; |
| 1216 | |
| 1217 | prev = cmpxchg(p, orig, rt); |
| 1218 | if (prev == orig) { |
| 1219 | dst_clone(&rt->dst); |
| 1220 | if (orig) |
| 1221 | call_rcu_bh(&orig->dst.rcu_head, rt_release_rcu); |
| 1222 | } |
| 1223 | } |
| 1224 | |
| 1225 | static bool rt_cache_valid(struct rtable *rt) |
| 1226 | { |
| 1227 | return (rt && rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK); |
| 1228 | } |
| 1229 | |
| 1230 | static void rt_set_nexthop(struct rtable *rt, __be32 daddr, |
| 1231 | const struct fib_result *res, |
| 1232 | struct fib_nh_exception *fnhe, |
| 1233 | struct fib_info *fi, u16 type, u32 itag) |
| 1234 | { |
| 1235 | if (fi) { |
| 1236 | struct fib_nh *nh = &FIB_RES_NH(*res); |
| 1237 | |
| 1238 | if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) |
| 1239 | rt->rt_gateway = nh->nh_gw; |
| 1240 | if (unlikely(fnhe)) |
| 1241 | rt_bind_exception(rt, fnhe, daddr); |
| 1242 | dst_init_metrics(&rt->dst, fi->fib_metrics, true); |
| 1243 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 1244 | rt->dst.tclassid = nh->nh_tclassid; |
| 1245 | #endif |
| 1246 | if (!(rt->dst.flags & DST_HOST)) |
| 1247 | rt_cache_route(nh, rt); |
| 1248 | } |
| 1249 | |
| 1250 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 1251 | #ifdef CONFIG_IP_MULTIPLE_TABLES |
| 1252 | set_class_tag(rt, res->tclassid); |
| 1253 | #endif |
| 1254 | set_class_tag(rt, itag); |
| 1255 | #endif |
| 1256 | } |
| 1257 | |
| 1258 | static struct rtable *rt_dst_alloc(struct net_device *dev, |
| 1259 | bool nopolicy, bool noxfrm, bool will_cache) |
| 1260 | { |
| 1261 | return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, |
| 1262 | (will_cache ? 0 : DST_HOST) | DST_NOCACHE | |
| 1263 | (nopolicy ? DST_NOPOLICY : 0) | |
| 1264 | (noxfrm ? DST_NOXFRM : 0)); |
| 1265 | } |
| 1266 | |
| 1267 | /* called in rcu_read_lock() section */ |
| 1268 | static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| 1269 | u8 tos, struct net_device *dev, int our) |
| 1270 | { |
| 1271 | struct rtable *rth; |
| 1272 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
| 1273 | u32 itag = 0; |
| 1274 | int err; |
| 1275 | |
| 1276 | /* Primary sanity checks. */ |
| 1277 | |
| 1278 | if (in_dev == NULL) |
| 1279 | return -EINVAL; |
| 1280 | |
| 1281 | if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || |
| 1282 | skb->protocol != htons(ETH_P_IP)) |
| 1283 | goto e_inval; |
| 1284 | |
| 1285 | if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) |
| 1286 | if (ipv4_is_loopback(saddr)) |
| 1287 | goto e_inval; |
| 1288 | |
| 1289 | if (ipv4_is_zeronet(saddr)) { |
| 1290 | if (!ipv4_is_local_multicast(daddr)) |
| 1291 | goto e_inval; |
| 1292 | } else { |
| 1293 | err = fib_validate_source(skb, saddr, 0, tos, 0, dev, |
| 1294 | in_dev, &itag); |
| 1295 | if (err < 0) |
| 1296 | goto e_err; |
| 1297 | } |
| 1298 | rth = rt_dst_alloc(dev_net(dev)->loopback_dev, |
| 1299 | IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); |
| 1300 | if (!rth) |
| 1301 | goto e_nobufs; |
| 1302 | |
| 1303 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 1304 | rth->dst.tclassid = itag; |
| 1305 | #endif |
| 1306 | rth->dst.output = ip_rt_bug; |
| 1307 | |
| 1308 | rth->rt_genid = rt_genid(dev_net(dev)); |
| 1309 | rth->rt_flags = RTCF_MULTICAST; |
| 1310 | rth->rt_type = RTN_MULTICAST; |
| 1311 | rth->rt_is_input= 1; |
| 1312 | rth->rt_iif = dev->ifindex; |
| 1313 | rth->rt_pmtu = 0; |
| 1314 | rth->rt_gateway = 0; |
| 1315 | if (our) { |
| 1316 | rth->dst.input= ip_local_deliver; |
| 1317 | rth->rt_flags |= RTCF_LOCAL; |
| 1318 | } |
| 1319 | |
| 1320 | #ifdef CONFIG_IP_MROUTE |
| 1321 | if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) |
| 1322 | rth->dst.input = ip_mr_input; |
| 1323 | #endif |
| 1324 | RT_CACHE_STAT_INC(in_slow_mc); |
| 1325 | |
| 1326 | skb_dst_set(skb, &rth->dst); |
| 1327 | return 0; |
| 1328 | |
| 1329 | e_nobufs: |
| 1330 | return -ENOBUFS; |
| 1331 | e_inval: |
| 1332 | return -EINVAL; |
| 1333 | e_err: |
| 1334 | return err; |
| 1335 | } |
| 1336 | |
| 1337 | |
| 1338 | static void ip_handle_martian_source(struct net_device *dev, |
| 1339 | struct in_device *in_dev, |
| 1340 | struct sk_buff *skb, |
| 1341 | __be32 daddr, |
| 1342 | __be32 saddr) |
| 1343 | { |
| 1344 | RT_CACHE_STAT_INC(in_martian_src); |
| 1345 | #ifdef CONFIG_IP_ROUTE_VERBOSE |
| 1346 | if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { |
| 1347 | /* |
| 1348 | * RFC1812 recommendation, if source is martian, |
| 1349 | * the only hint is MAC header. |
| 1350 | */ |
| 1351 | pr_warn("martian source %pI4 from %pI4, on dev %s\n", |
| 1352 | &daddr, &saddr, dev->name); |
| 1353 | if (dev->hard_header_len && skb_mac_header_was_set(skb)) { |
| 1354 | print_hex_dump(KERN_WARNING, "ll header: ", |
| 1355 | DUMP_PREFIX_OFFSET, 16, 1, |
| 1356 | skb_mac_header(skb), |
| 1357 | dev->hard_header_len, true); |
| 1358 | } |
| 1359 | } |
| 1360 | #endif |
| 1361 | } |
| 1362 | |
| 1363 | /* called in rcu_read_lock() section */ |
| 1364 | static int __mkroute_input(struct sk_buff *skb, |
| 1365 | const struct fib_result *res, |
| 1366 | struct in_device *in_dev, |
| 1367 | __be32 daddr, __be32 saddr, u32 tos, |
| 1368 | struct rtable **result) |
| 1369 | { |
| 1370 | struct rtable *rth; |
| 1371 | int err; |
| 1372 | struct in_device *out_dev; |
| 1373 | unsigned int flags = 0; |
| 1374 | bool do_cache; |
| 1375 | u32 itag; |
| 1376 | |
| 1377 | /* get a working reference to the output device */ |
| 1378 | out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); |
| 1379 | if (out_dev == NULL) { |
| 1380 | net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); |
| 1381 | return -EINVAL; |
| 1382 | } |
| 1383 | |
| 1384 | |
| 1385 | err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), |
| 1386 | in_dev->dev, in_dev, &itag); |
| 1387 | if (err < 0) { |
| 1388 | ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, |
| 1389 | saddr); |
| 1390 | |
| 1391 | goto cleanup; |
| 1392 | } |
| 1393 | |
| 1394 | if (err) |
| 1395 | flags |= RTCF_DIRECTSRC; |
| 1396 | |
| 1397 | if (out_dev == in_dev && err && |
| 1398 | (IN_DEV_SHARED_MEDIA(out_dev) || |
| 1399 | inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) |
| 1400 | flags |= RTCF_DOREDIRECT; |
| 1401 | |
| 1402 | if (skb->protocol != htons(ETH_P_IP)) { |
| 1403 | /* Not IP (i.e. ARP). Do not create route, if it is |
| 1404 | * invalid for proxy arp. DNAT routes are always valid. |
| 1405 | * |
| 1406 | * Proxy arp feature have been extended to allow, ARP |
| 1407 | * replies back to the same interface, to support |
| 1408 | * Private VLAN switch technologies. See arp.c. |
| 1409 | */ |
| 1410 | if (out_dev == in_dev && |
| 1411 | IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { |
| 1412 | err = -EINVAL; |
| 1413 | goto cleanup; |
| 1414 | } |
| 1415 | } |
| 1416 | |
| 1417 | do_cache = false; |
| 1418 | if (res->fi) { |
| 1419 | if (!(flags & RTCF_DIRECTSRC) && !itag) { |
| 1420 | rth = FIB_RES_NH(*res).nh_rth_input; |
| 1421 | if (rt_cache_valid(rth)) { |
| 1422 | dst_hold(&rth->dst); |
| 1423 | goto out; |
| 1424 | } |
| 1425 | do_cache = true; |
| 1426 | } |
| 1427 | } |
| 1428 | |
| 1429 | rth = rt_dst_alloc(out_dev->dev, |
| 1430 | IN_DEV_CONF_GET(in_dev, NOPOLICY), |
| 1431 | IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); |
| 1432 | if (!rth) { |
| 1433 | err = -ENOBUFS; |
| 1434 | goto cleanup; |
| 1435 | } |
| 1436 | |
| 1437 | rth->rt_genid = rt_genid(dev_net(rth->dst.dev)); |
| 1438 | rth->rt_flags = flags; |
| 1439 | rth->rt_type = res->type; |
| 1440 | rth->rt_is_input = 1; |
| 1441 | rth->rt_iif = in_dev->dev->ifindex; |
| 1442 | rth->rt_pmtu = 0; |
| 1443 | rth->rt_gateway = 0; |
| 1444 | |
| 1445 | rth->dst.input = ip_forward; |
| 1446 | rth->dst.output = ip_output; |
| 1447 | |
| 1448 | rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag); |
| 1449 | out: |
| 1450 | *result = rth; |
| 1451 | err = 0; |
| 1452 | cleanup: |
| 1453 | return err; |
| 1454 | } |
| 1455 | |
| 1456 | static int ip_mkroute_input(struct sk_buff *skb, |
| 1457 | struct fib_result *res, |
| 1458 | const struct flowi4 *fl4, |
| 1459 | struct in_device *in_dev, |
| 1460 | __be32 daddr, __be32 saddr, u32 tos) |
| 1461 | { |
| 1462 | struct rtable *rth = NULL; |
| 1463 | int err; |
| 1464 | |
| 1465 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| 1466 | if (res->fi && res->fi->fib_nhs > 1) |
| 1467 | fib_select_multipath(res); |
| 1468 | #endif |
| 1469 | |
| 1470 | /* create a routing cache entry */ |
| 1471 | err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth); |
| 1472 | if (err) |
| 1473 | return err; |
| 1474 | |
| 1475 | skb_dst_set(skb, &rth->dst); |
| 1476 | return 0; |
| 1477 | } |
| 1478 | |
| 1479 | /* |
| 1480 | * NOTE. We drop all the packets that has local source |
| 1481 | * addresses, because every properly looped back packet |
| 1482 | * must have correct destination already attached by output routine. |
| 1483 | * |
| 1484 | * Such approach solves two big problems: |
| 1485 | * 1. Not simplex devices are handled properly. |
| 1486 | * 2. IP spoofing attempts are filtered with 100% of guarantee. |
| 1487 | * called with rcu_read_lock() |
| 1488 | */ |
| 1489 | |
| 1490 | static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| 1491 | u8 tos, struct net_device *dev) |
| 1492 | { |
| 1493 | struct fib_result res; |
| 1494 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
| 1495 | struct flowi4 fl4; |
| 1496 | unsigned int flags = 0; |
| 1497 | u32 itag = 0; |
| 1498 | struct rtable *rth; |
| 1499 | int err = -EINVAL; |
| 1500 | struct net *net = dev_net(dev); |
| 1501 | bool do_cache; |
| 1502 | |
| 1503 | /* IP on this device is disabled. */ |
| 1504 | |
| 1505 | if (!in_dev) |
| 1506 | goto out; |
| 1507 | |
| 1508 | /* Check for the most weird martians, which can be not detected |
| 1509 | by fib_lookup. |
| 1510 | */ |
| 1511 | |
| 1512 | if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) |
| 1513 | goto martian_source; |
| 1514 | |
| 1515 | res.fi = NULL; |
| 1516 | if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) |
| 1517 | goto brd_input; |
| 1518 | |
| 1519 | /* Accept zero addresses only to limited broadcast; |
| 1520 | * I even do not know to fix it or not. Waiting for complains :-) |
| 1521 | */ |
| 1522 | if (ipv4_is_zeronet(saddr)) |
| 1523 | goto martian_source; |
| 1524 | |
| 1525 | if (ipv4_is_zeronet(daddr)) |
| 1526 | goto martian_destination; |
| 1527 | |
| 1528 | if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) { |
| 1529 | if (ipv4_is_loopback(daddr)) |
| 1530 | goto martian_destination; |
| 1531 | |
| 1532 | if (ipv4_is_loopback(saddr)) |
| 1533 | goto martian_source; |
| 1534 | } |
| 1535 | |
| 1536 | /* |
| 1537 | * Now we are ready to route packet. |
| 1538 | */ |
| 1539 | fl4.flowi4_oif = 0; |
| 1540 | fl4.flowi4_iif = dev->ifindex; |
| 1541 | fl4.flowi4_mark = skb->mark; |
| 1542 | fl4.flowi4_tos = tos; |
| 1543 | fl4.flowi4_scope = RT_SCOPE_UNIVERSE; |
| 1544 | fl4.daddr = daddr; |
| 1545 | fl4.saddr = saddr; |
| 1546 | err = fib_lookup(net, &fl4, &res); |
| 1547 | if (err != 0) |
| 1548 | goto no_route; |
| 1549 | |
| 1550 | RT_CACHE_STAT_INC(in_slow_tot); |
| 1551 | |
| 1552 | if (res.type == RTN_BROADCAST) |
| 1553 | goto brd_input; |
| 1554 | |
| 1555 | if (res.type == RTN_LOCAL) { |
| 1556 | err = fib_validate_source(skb, saddr, daddr, tos, |
| 1557 | net->loopback_dev->ifindex, |
| 1558 | dev, in_dev, &itag); |
| 1559 | if (err < 0) |
| 1560 | goto martian_source_keep_err; |
| 1561 | if (err) |
| 1562 | flags |= RTCF_DIRECTSRC; |
| 1563 | goto local_input; |
| 1564 | } |
| 1565 | |
| 1566 | if (!IN_DEV_FORWARD(in_dev)) |
| 1567 | goto no_route; |
| 1568 | if (res.type != RTN_UNICAST) |
| 1569 | goto martian_destination; |
| 1570 | |
| 1571 | err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); |
| 1572 | out: return err; |
| 1573 | |
| 1574 | brd_input: |
| 1575 | if (skb->protocol != htons(ETH_P_IP)) |
| 1576 | goto e_inval; |
| 1577 | |
| 1578 | if (!ipv4_is_zeronet(saddr)) { |
| 1579 | err = fib_validate_source(skb, saddr, 0, tos, 0, dev, |
| 1580 | in_dev, &itag); |
| 1581 | if (err < 0) |
| 1582 | goto martian_source_keep_err; |
| 1583 | if (err) |
| 1584 | flags |= RTCF_DIRECTSRC; |
| 1585 | } |
| 1586 | flags |= RTCF_BROADCAST; |
| 1587 | res.type = RTN_BROADCAST; |
| 1588 | RT_CACHE_STAT_INC(in_brd); |
| 1589 | |
| 1590 | local_input: |
| 1591 | do_cache = false; |
| 1592 | if (res.fi) { |
| 1593 | if (!(flags & RTCF_DIRECTSRC) && !itag) { |
| 1594 | rth = FIB_RES_NH(res).nh_rth_input; |
| 1595 | if (rt_cache_valid(rth)) { |
| 1596 | dst_hold(&rth->dst); |
| 1597 | goto set_and_out; |
| 1598 | } |
| 1599 | do_cache = true; |
| 1600 | } |
| 1601 | } |
| 1602 | |
| 1603 | rth = rt_dst_alloc(net->loopback_dev, |
| 1604 | IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); |
| 1605 | if (!rth) |
| 1606 | goto e_nobufs; |
| 1607 | |
| 1608 | rth->dst.input= ip_local_deliver; |
| 1609 | rth->dst.output= ip_rt_bug; |
| 1610 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 1611 | rth->dst.tclassid = itag; |
| 1612 | #endif |
| 1613 | |
| 1614 | rth->rt_genid = rt_genid(net); |
| 1615 | rth->rt_flags = flags|RTCF_LOCAL; |
| 1616 | rth->rt_type = res.type; |
| 1617 | rth->rt_is_input = 1; |
| 1618 | rth->rt_iif = dev->ifindex; |
| 1619 | rth->rt_pmtu = 0; |
| 1620 | rth->rt_gateway = 0; |
| 1621 | if (res.type == RTN_UNREACHABLE) { |
| 1622 | rth->dst.input= ip_error; |
| 1623 | rth->dst.error= -err; |
| 1624 | rth->rt_flags &= ~RTCF_LOCAL; |
| 1625 | } |
| 1626 | if (do_cache) |
| 1627 | rt_cache_route(&FIB_RES_NH(res), rth); |
| 1628 | set_and_out: |
| 1629 | skb_dst_set(skb, &rth->dst); |
| 1630 | err = 0; |
| 1631 | goto out; |
| 1632 | |
| 1633 | no_route: |
| 1634 | RT_CACHE_STAT_INC(in_no_route); |
| 1635 | res.type = RTN_UNREACHABLE; |
| 1636 | if (err == -ESRCH) |
| 1637 | err = -ENETUNREACH; |
| 1638 | goto local_input; |
| 1639 | |
| 1640 | /* |
| 1641 | * Do not cache martian addresses: they should be logged (RFC1812) |
| 1642 | */ |
| 1643 | martian_destination: |
| 1644 | RT_CACHE_STAT_INC(in_martian_dst); |
| 1645 | #ifdef CONFIG_IP_ROUTE_VERBOSE |
| 1646 | if (IN_DEV_LOG_MARTIANS(in_dev)) |
| 1647 | net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", |
| 1648 | &daddr, &saddr, dev->name); |
| 1649 | #endif |
| 1650 | |
| 1651 | e_inval: |
| 1652 | err = -EINVAL; |
| 1653 | goto out; |
| 1654 | |
| 1655 | e_nobufs: |
| 1656 | err = -ENOBUFS; |
| 1657 | goto out; |
| 1658 | |
| 1659 | martian_source: |
| 1660 | err = -EINVAL; |
| 1661 | martian_source_keep_err: |
| 1662 | ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); |
| 1663 | goto out; |
| 1664 | } |
| 1665 | |
| 1666 | int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| 1667 | u8 tos, struct net_device *dev) |
| 1668 | { |
| 1669 | int res; |
| 1670 | |
| 1671 | rcu_read_lock(); |
| 1672 | |
| 1673 | /* Multicast recognition logic is moved from route cache to here. |
| 1674 | The problem was that too many Ethernet cards have broken/missing |
| 1675 | hardware multicast filters :-( As result the host on multicasting |
| 1676 | network acquires a lot of useless route cache entries, sort of |
| 1677 | SDR messages from all the world. Now we try to get rid of them. |
| 1678 | Really, provided software IP multicast filter is organized |
| 1679 | reasonably (at least, hashed), it does not result in a slowdown |
| 1680 | comparing with route cache reject entries. |
| 1681 | Note, that multicast routers are not affected, because |
| 1682 | route cache entry is created eventually. |
| 1683 | */ |
| 1684 | if (ipv4_is_multicast(daddr)) { |
| 1685 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
| 1686 | |
| 1687 | if (in_dev) { |
| 1688 | int our = ip_check_mc_rcu(in_dev, daddr, saddr, |
| 1689 | ip_hdr(skb)->protocol); |
| 1690 | if (our |
| 1691 | #ifdef CONFIG_IP_MROUTE |
| 1692 | || |
| 1693 | (!ipv4_is_local_multicast(daddr) && |
| 1694 | IN_DEV_MFORWARD(in_dev)) |
| 1695 | #endif |
| 1696 | ) { |
| 1697 | int res = ip_route_input_mc(skb, daddr, saddr, |
| 1698 | tos, dev, our); |
| 1699 | rcu_read_unlock(); |
| 1700 | return res; |
| 1701 | } |
| 1702 | } |
| 1703 | rcu_read_unlock(); |
| 1704 | return -EINVAL; |
| 1705 | } |
| 1706 | res = ip_route_input_slow(skb, daddr, saddr, tos, dev); |
| 1707 | rcu_read_unlock(); |
| 1708 | return res; |
| 1709 | } |
| 1710 | EXPORT_SYMBOL(ip_route_input); |
| 1711 | |
| 1712 | /* called with rcu_read_lock() */ |
| 1713 | static struct rtable *__mkroute_output(const struct fib_result *res, |
| 1714 | const struct flowi4 *fl4, int orig_oif, |
| 1715 | struct net_device *dev_out, |
| 1716 | unsigned int flags) |
| 1717 | { |
| 1718 | struct fib_info *fi = res->fi; |
| 1719 | struct fib_nh_exception *fnhe; |
| 1720 | struct in_device *in_dev; |
| 1721 | u16 type = res->type; |
| 1722 | struct rtable *rth; |
| 1723 | |
| 1724 | in_dev = __in_dev_get_rcu(dev_out); |
| 1725 | if (!in_dev) |
| 1726 | return ERR_PTR(-EINVAL); |
| 1727 | |
| 1728 | if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) |
| 1729 | if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) |
| 1730 | return ERR_PTR(-EINVAL); |
| 1731 | |
| 1732 | if (ipv4_is_lbcast(fl4->daddr)) |
| 1733 | type = RTN_BROADCAST; |
| 1734 | else if (ipv4_is_multicast(fl4->daddr)) |
| 1735 | type = RTN_MULTICAST; |
| 1736 | else if (ipv4_is_zeronet(fl4->daddr)) |
| 1737 | return ERR_PTR(-EINVAL); |
| 1738 | |
| 1739 | if (dev_out->flags & IFF_LOOPBACK) |
| 1740 | flags |= RTCF_LOCAL; |
| 1741 | |
| 1742 | if (type == RTN_BROADCAST) { |
| 1743 | flags |= RTCF_BROADCAST | RTCF_LOCAL; |
| 1744 | fi = NULL; |
| 1745 | } else if (type == RTN_MULTICAST) { |
| 1746 | flags |= RTCF_MULTICAST | RTCF_LOCAL; |
| 1747 | if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, |
| 1748 | fl4->flowi4_proto)) |
| 1749 | flags &= ~RTCF_LOCAL; |
| 1750 | /* If multicast route do not exist use |
| 1751 | * default one, but do not gateway in this case. |
| 1752 | * Yes, it is hack. |
| 1753 | */ |
| 1754 | if (fi && res->prefixlen < 4) |
| 1755 | fi = NULL; |
| 1756 | } |
| 1757 | |
| 1758 | fnhe = NULL; |
| 1759 | if (fi) { |
| 1760 | fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr); |
| 1761 | if (!fnhe) { |
| 1762 | rth = FIB_RES_NH(*res).nh_rth_output; |
| 1763 | if (rt_cache_valid(rth)) { |
| 1764 | dst_hold(&rth->dst); |
| 1765 | return rth; |
| 1766 | } |
| 1767 | } |
| 1768 | } |
| 1769 | rth = rt_dst_alloc(dev_out, |
| 1770 | IN_DEV_CONF_GET(in_dev, NOPOLICY), |
| 1771 | IN_DEV_CONF_GET(in_dev, NOXFRM), |
| 1772 | fi && !fnhe); |
| 1773 | if (!rth) |
| 1774 | return ERR_PTR(-ENOBUFS); |
| 1775 | |
| 1776 | rth->dst.output = ip_output; |
| 1777 | |
| 1778 | rth->rt_genid = rt_genid(dev_net(dev_out)); |
| 1779 | rth->rt_flags = flags; |
| 1780 | rth->rt_type = type; |
| 1781 | rth->rt_is_input = 0; |
| 1782 | rth->rt_iif = orig_oif ? : dev_out->ifindex; |
| 1783 | rth->rt_pmtu = 0; |
| 1784 | rth->rt_gateway = 0; |
| 1785 | |
| 1786 | RT_CACHE_STAT_INC(out_slow_tot); |
| 1787 | |
| 1788 | if (flags & RTCF_LOCAL) |
| 1789 | rth->dst.input = ip_local_deliver; |
| 1790 | if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
| 1791 | if (flags & RTCF_LOCAL && |
| 1792 | !(dev_out->flags & IFF_LOOPBACK)) { |
| 1793 | rth->dst.output = ip_mc_output; |
| 1794 | RT_CACHE_STAT_INC(out_slow_mc); |
| 1795 | } |
| 1796 | #ifdef CONFIG_IP_MROUTE |
| 1797 | if (type == RTN_MULTICAST) { |
| 1798 | if (IN_DEV_MFORWARD(in_dev) && |
| 1799 | !ipv4_is_local_multicast(fl4->daddr)) { |
| 1800 | rth->dst.input = ip_mr_input; |
| 1801 | rth->dst.output = ip_mc_output; |
| 1802 | } |
| 1803 | } |
| 1804 | #endif |
| 1805 | } |
| 1806 | |
| 1807 | rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); |
| 1808 | |
| 1809 | return rth; |
| 1810 | } |
| 1811 | |
| 1812 | /* |
| 1813 | * Major route resolver routine. |
| 1814 | */ |
| 1815 | |
| 1816 | struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) |
| 1817 | { |
| 1818 | struct net_device *dev_out = NULL; |
| 1819 | __u8 tos = RT_FL_TOS(fl4); |
| 1820 | unsigned int flags = 0; |
| 1821 | struct fib_result res; |
| 1822 | struct rtable *rth; |
| 1823 | int orig_oif; |
| 1824 | |
| 1825 | res.tclassid = 0; |
| 1826 | res.fi = NULL; |
| 1827 | res.table = NULL; |
| 1828 | |
| 1829 | orig_oif = fl4->flowi4_oif; |
| 1830 | |
| 1831 | fl4->flowi4_iif = net->loopback_dev->ifindex; |
| 1832 | fl4->flowi4_tos = tos & IPTOS_RT_MASK; |
| 1833 | fl4->flowi4_scope = ((tos & RTO_ONLINK) ? |
| 1834 | RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); |
| 1835 | |
| 1836 | rcu_read_lock(); |
| 1837 | if (fl4->saddr) { |
| 1838 | rth = ERR_PTR(-EINVAL); |
| 1839 | if (ipv4_is_multicast(fl4->saddr) || |
| 1840 | ipv4_is_lbcast(fl4->saddr) || |
| 1841 | ipv4_is_zeronet(fl4->saddr)) |
| 1842 | goto out; |
| 1843 | |
| 1844 | /* I removed check for oif == dev_out->oif here. |
| 1845 | It was wrong for two reasons: |
| 1846 | 1. ip_dev_find(net, saddr) can return wrong iface, if saddr |
| 1847 | is assigned to multiple interfaces. |
| 1848 | 2. Moreover, we are allowed to send packets with saddr |
| 1849 | of another iface. --ANK |
| 1850 | */ |
| 1851 | |
| 1852 | if (fl4->flowi4_oif == 0 && |
| 1853 | (ipv4_is_multicast(fl4->daddr) || |
| 1854 | ipv4_is_lbcast(fl4->daddr))) { |
| 1855 | /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ |
| 1856 | dev_out = __ip_dev_find(net, fl4->saddr, false); |
| 1857 | if (dev_out == NULL) |
| 1858 | goto out; |
| 1859 | |
| 1860 | /* Special hack: user can direct multicasts |
| 1861 | and limited broadcast via necessary interface |
| 1862 | without fiddling with IP_MULTICAST_IF or IP_PKTINFO. |
| 1863 | This hack is not just for fun, it allows |
| 1864 | vic,vat and friends to work. |
| 1865 | They bind socket to loopback, set ttl to zero |
| 1866 | and expect that it will work. |
| 1867 | From the viewpoint of routing cache they are broken, |
| 1868 | because we are not allowed to build multicast path |
| 1869 | with loopback source addr (look, routing cache |
| 1870 | cannot know, that ttl is zero, so that packet |
| 1871 | will not leave this host and route is valid). |
| 1872 | Luckily, this hack is good workaround. |
| 1873 | */ |
| 1874 | |
| 1875 | fl4->flowi4_oif = dev_out->ifindex; |
| 1876 | goto make_route; |
| 1877 | } |
| 1878 | |
| 1879 | if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { |
| 1880 | /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ |
| 1881 | if (!__ip_dev_find(net, fl4->saddr, false)) |
| 1882 | goto out; |
| 1883 | } |
| 1884 | } |
| 1885 | |
| 1886 | |
| 1887 | if (fl4->flowi4_oif) { |
| 1888 | dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); |
| 1889 | rth = ERR_PTR(-ENODEV); |
| 1890 | if (dev_out == NULL) |
| 1891 | goto out; |
| 1892 | |
| 1893 | /* RACE: Check return value of inet_select_addr instead. */ |
| 1894 | if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { |
| 1895 | rth = ERR_PTR(-ENETUNREACH); |
| 1896 | goto out; |
| 1897 | } |
| 1898 | if (ipv4_is_local_multicast(fl4->daddr) || |
| 1899 | ipv4_is_lbcast(fl4->daddr)) { |
| 1900 | if (!fl4->saddr) |
| 1901 | fl4->saddr = inet_select_addr(dev_out, 0, |
| 1902 | RT_SCOPE_LINK); |
| 1903 | goto make_route; |
| 1904 | } |
| 1905 | if (fl4->saddr) { |
| 1906 | if (ipv4_is_multicast(fl4->daddr)) |
| 1907 | fl4->saddr = inet_select_addr(dev_out, 0, |
| 1908 | fl4->flowi4_scope); |
| 1909 | else if (!fl4->daddr) |
| 1910 | fl4->saddr = inet_select_addr(dev_out, 0, |
| 1911 | RT_SCOPE_HOST); |
| 1912 | } |
| 1913 | } |
| 1914 | |
| 1915 | if (!fl4->daddr) { |
| 1916 | fl4->daddr = fl4->saddr; |
| 1917 | if (!fl4->daddr) |
| 1918 | fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); |
| 1919 | dev_out = net->loopback_dev; |
| 1920 | fl4->flowi4_oif = net->loopback_dev->ifindex; |
| 1921 | res.type = RTN_LOCAL; |
| 1922 | flags |= RTCF_LOCAL; |
| 1923 | goto make_route; |
| 1924 | } |
| 1925 | |
| 1926 | if (fib_lookup(net, fl4, &res)) { |
| 1927 | res.fi = NULL; |
| 1928 | res.table = NULL; |
| 1929 | if (fl4->flowi4_oif) { |
| 1930 | /* Apparently, routing tables are wrong. Assume, |
| 1931 | that the destination is on link. |
| 1932 | |
| 1933 | WHY? DW. |
| 1934 | Because we are allowed to send to iface |
| 1935 | even if it has NO routes and NO assigned |
| 1936 | addresses. When oif is specified, routing |
| 1937 | tables are looked up with only one purpose: |
| 1938 | to catch if destination is gatewayed, rather than |
| 1939 | direct. Moreover, if MSG_DONTROUTE is set, |
| 1940 | we send packet, ignoring both routing tables |
| 1941 | and ifaddr state. --ANK |
| 1942 | |
| 1943 | |
| 1944 | We could make it even if oif is unknown, |
| 1945 | likely IPv6, but we do not. |
| 1946 | */ |
| 1947 | |
| 1948 | if (fl4->saddr == 0) |
| 1949 | fl4->saddr = inet_select_addr(dev_out, 0, |
| 1950 | RT_SCOPE_LINK); |
| 1951 | res.type = RTN_UNICAST; |
| 1952 | goto make_route; |
| 1953 | } |
| 1954 | rth = ERR_PTR(-ENETUNREACH); |
| 1955 | goto out; |
| 1956 | } |
| 1957 | |
| 1958 | if (res.type == RTN_LOCAL) { |
| 1959 | if (!fl4->saddr) { |
| 1960 | if (res.fi->fib_prefsrc) |
| 1961 | fl4->saddr = res.fi->fib_prefsrc; |
| 1962 | else |
| 1963 | fl4->saddr = fl4->daddr; |
| 1964 | } |
| 1965 | dev_out = net->loopback_dev; |
| 1966 | fl4->flowi4_oif = dev_out->ifindex; |
| 1967 | res.fi = NULL; |
| 1968 | flags |= RTCF_LOCAL; |
| 1969 | goto make_route; |
| 1970 | } |
| 1971 | |
| 1972 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| 1973 | if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) |
| 1974 | fib_select_multipath(&res); |
| 1975 | else |
| 1976 | #endif |
| 1977 | if (!res.prefixlen && |
| 1978 | res.table->tb_num_default > 1 && |
| 1979 | res.type == RTN_UNICAST && !fl4->flowi4_oif) |
| 1980 | fib_select_default(&res); |
| 1981 | |
| 1982 | if (!fl4->saddr) |
| 1983 | fl4->saddr = FIB_RES_PREFSRC(net, res); |
| 1984 | |
| 1985 | dev_out = FIB_RES_DEV(res); |
| 1986 | fl4->flowi4_oif = dev_out->ifindex; |
| 1987 | |
| 1988 | |
| 1989 | make_route: |
| 1990 | rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); |
| 1991 | |
| 1992 | out: |
| 1993 | rcu_read_unlock(); |
| 1994 | return rth; |
| 1995 | } |
| 1996 | EXPORT_SYMBOL_GPL(__ip_route_output_key); |
| 1997 | |
| 1998 | static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) |
| 1999 | { |
| 2000 | return NULL; |
| 2001 | } |
| 2002 | |
| 2003 | static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) |
| 2004 | { |
| 2005 | unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); |
| 2006 | |
| 2007 | return mtu ? : dst->dev->mtu; |
| 2008 | } |
| 2009 | |
| 2010 | static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, |
| 2011 | struct sk_buff *skb, u32 mtu) |
| 2012 | { |
| 2013 | } |
| 2014 | |
| 2015 | static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, |
| 2016 | struct sk_buff *skb) |
| 2017 | { |
| 2018 | } |
| 2019 | |
| 2020 | static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, |
| 2021 | unsigned long old) |
| 2022 | { |
| 2023 | return NULL; |
| 2024 | } |
| 2025 | |
| 2026 | static struct dst_ops ipv4_dst_blackhole_ops = { |
| 2027 | .family = AF_INET, |
| 2028 | .protocol = cpu_to_be16(ETH_P_IP), |
| 2029 | .check = ipv4_blackhole_dst_check, |
| 2030 | .mtu = ipv4_blackhole_mtu, |
| 2031 | .default_advmss = ipv4_default_advmss, |
| 2032 | .update_pmtu = ipv4_rt_blackhole_update_pmtu, |
| 2033 | .redirect = ipv4_rt_blackhole_redirect, |
| 2034 | .cow_metrics = ipv4_rt_blackhole_cow_metrics, |
| 2035 | .neigh_lookup = ipv4_neigh_lookup, |
| 2036 | }; |
| 2037 | |
| 2038 | struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) |
| 2039 | { |
| 2040 | struct rtable *ort = (struct rtable *) dst_orig; |
| 2041 | struct rtable *rt; |
| 2042 | |
| 2043 | rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); |
| 2044 | if (rt) { |
| 2045 | struct dst_entry *new = &rt->dst; |
| 2046 | |
| 2047 | new->__use = 1; |
| 2048 | new->input = dst_discard; |
| 2049 | new->output = dst_discard; |
| 2050 | |
| 2051 | new->dev = ort->dst.dev; |
| 2052 | if (new->dev) |
| 2053 | dev_hold(new->dev); |
| 2054 | |
| 2055 | rt->rt_is_input = ort->rt_is_input; |
| 2056 | rt->rt_iif = ort->rt_iif; |
| 2057 | rt->rt_pmtu = ort->rt_pmtu; |
| 2058 | |
| 2059 | rt->rt_genid = rt_genid(net); |
| 2060 | rt->rt_flags = ort->rt_flags; |
| 2061 | rt->rt_type = ort->rt_type; |
| 2062 | rt->rt_gateway = ort->rt_gateway; |
| 2063 | |
| 2064 | dst_free(new); |
| 2065 | } |
| 2066 | |
| 2067 | dst_release(dst_orig); |
| 2068 | |
| 2069 | return rt ? &rt->dst : ERR_PTR(-ENOMEM); |
| 2070 | } |
| 2071 | |
| 2072 | struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, |
| 2073 | struct sock *sk) |
| 2074 | { |
| 2075 | struct rtable *rt = __ip_route_output_key(net, flp4); |
| 2076 | |
| 2077 | if (IS_ERR(rt)) |
| 2078 | return rt; |
| 2079 | |
| 2080 | if (flp4->flowi4_proto) |
| 2081 | rt = (struct rtable *) xfrm_lookup(net, &rt->dst, |
| 2082 | flowi4_to_flowi(flp4), |
| 2083 | sk, 0); |
| 2084 | |
| 2085 | return rt; |
| 2086 | } |
| 2087 | EXPORT_SYMBOL_GPL(ip_route_output_flow); |
| 2088 | |
| 2089 | static int rt_fill_info(struct net *net, __be32 dst, __be32 src, |
| 2090 | struct flowi4 *fl4, struct sk_buff *skb, u32 pid, |
| 2091 | u32 seq, int event, int nowait, unsigned int flags) |
| 2092 | { |
| 2093 | struct rtable *rt = skb_rtable(skb); |
| 2094 | struct rtmsg *r; |
| 2095 | struct nlmsghdr *nlh; |
| 2096 | unsigned long expires = 0; |
| 2097 | u32 error; |
| 2098 | u32 metrics[RTAX_MAX]; |
| 2099 | |
| 2100 | nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); |
| 2101 | if (nlh == NULL) |
| 2102 | return -EMSGSIZE; |
| 2103 | |
| 2104 | r = nlmsg_data(nlh); |
| 2105 | r->rtm_family = AF_INET; |
| 2106 | r->rtm_dst_len = 32; |
| 2107 | r->rtm_src_len = 0; |
| 2108 | r->rtm_tos = fl4->flowi4_tos; |
| 2109 | r->rtm_table = RT_TABLE_MAIN; |
| 2110 | if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) |
| 2111 | goto nla_put_failure; |
| 2112 | r->rtm_type = rt->rt_type; |
| 2113 | r->rtm_scope = RT_SCOPE_UNIVERSE; |
| 2114 | r->rtm_protocol = RTPROT_UNSPEC; |
| 2115 | r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; |
| 2116 | if (rt->rt_flags & RTCF_NOTIFY) |
| 2117 | r->rtm_flags |= RTM_F_NOTIFY; |
| 2118 | |
| 2119 | if (nla_put_be32(skb, RTA_DST, dst)) |
| 2120 | goto nla_put_failure; |
| 2121 | if (src) { |
| 2122 | r->rtm_src_len = 32; |
| 2123 | if (nla_put_be32(skb, RTA_SRC, src)) |
| 2124 | goto nla_put_failure; |
| 2125 | } |
| 2126 | if (rt->dst.dev && |
| 2127 | nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) |
| 2128 | goto nla_put_failure; |
| 2129 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 2130 | if (rt->dst.tclassid && |
| 2131 | nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) |
| 2132 | goto nla_put_failure; |
| 2133 | #endif |
| 2134 | if (!rt_is_input_route(rt) && |
| 2135 | fl4->saddr != src) { |
| 2136 | if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr)) |
| 2137 | goto nla_put_failure; |
| 2138 | } |
| 2139 | if (rt->rt_gateway && |
| 2140 | nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway)) |
| 2141 | goto nla_put_failure; |
| 2142 | |
| 2143 | memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); |
| 2144 | if (rt->rt_pmtu) |
| 2145 | metrics[RTAX_MTU - 1] = rt->rt_pmtu; |
| 2146 | if (rtnetlink_put_metrics(skb, metrics) < 0) |
| 2147 | goto nla_put_failure; |
| 2148 | |
| 2149 | if (fl4->flowi4_mark && |
| 2150 | nla_put_be32(skb, RTA_MARK, fl4->flowi4_mark)) |
| 2151 | goto nla_put_failure; |
| 2152 | |
| 2153 | error = rt->dst.error; |
| 2154 | expires = rt->dst.expires; |
| 2155 | if (expires) { |
| 2156 | if (time_before(jiffies, expires)) |
| 2157 | expires -= jiffies; |
| 2158 | else |
| 2159 | expires = 0; |
| 2160 | } |
| 2161 | |
| 2162 | if (rt_is_input_route(rt)) { |
| 2163 | if (nla_put_u32(skb, RTA_IIF, rt->rt_iif)) |
| 2164 | goto nla_put_failure; |
| 2165 | } |
| 2166 | |
| 2167 | if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) |
| 2168 | goto nla_put_failure; |
| 2169 | |
| 2170 | return nlmsg_end(skb, nlh); |
| 2171 | |
| 2172 | nla_put_failure: |
| 2173 | nlmsg_cancel(skb, nlh); |
| 2174 | return -EMSGSIZE; |
| 2175 | } |
| 2176 | |
| 2177 | static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg) |
| 2178 | { |
| 2179 | struct net *net = sock_net(in_skb->sk); |
| 2180 | struct rtmsg *rtm; |
| 2181 | struct nlattr *tb[RTA_MAX+1]; |
| 2182 | struct rtable *rt = NULL; |
| 2183 | struct flowi4 fl4; |
| 2184 | __be32 dst = 0; |
| 2185 | __be32 src = 0; |
| 2186 | u32 iif; |
| 2187 | int err; |
| 2188 | int mark; |
| 2189 | struct sk_buff *skb; |
| 2190 | |
| 2191 | err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); |
| 2192 | if (err < 0) |
| 2193 | goto errout; |
| 2194 | |
| 2195 | rtm = nlmsg_data(nlh); |
| 2196 | |
| 2197 | skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); |
| 2198 | if (skb == NULL) { |
| 2199 | err = -ENOBUFS; |
| 2200 | goto errout; |
| 2201 | } |
| 2202 | |
| 2203 | /* Reserve room for dummy headers, this skb can pass |
| 2204 | through good chunk of routing engine. |
| 2205 | */ |
| 2206 | skb_reset_mac_header(skb); |
| 2207 | skb_reset_network_header(skb); |
| 2208 | |
| 2209 | /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ |
| 2210 | ip_hdr(skb)->protocol = IPPROTO_ICMP; |
| 2211 | skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); |
| 2212 | |
| 2213 | src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; |
| 2214 | dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; |
| 2215 | iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; |
| 2216 | mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; |
| 2217 | |
| 2218 | memset(&fl4, 0, sizeof(fl4)); |
| 2219 | fl4.daddr = dst; |
| 2220 | fl4.saddr = src; |
| 2221 | fl4.flowi4_tos = rtm->rtm_tos; |
| 2222 | fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; |
| 2223 | fl4.flowi4_mark = mark; |
| 2224 | |
| 2225 | if (iif) { |
| 2226 | struct net_device *dev; |
| 2227 | |
| 2228 | dev = __dev_get_by_index(net, iif); |
| 2229 | if (dev == NULL) { |
| 2230 | err = -ENODEV; |
| 2231 | goto errout_free; |
| 2232 | } |
| 2233 | |
| 2234 | skb->protocol = htons(ETH_P_IP); |
| 2235 | skb->dev = dev; |
| 2236 | skb->mark = mark; |
| 2237 | local_bh_disable(); |
| 2238 | err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); |
| 2239 | local_bh_enable(); |
| 2240 | |
| 2241 | rt = skb_rtable(skb); |
| 2242 | if (err == 0 && rt->dst.error) |
| 2243 | err = -rt->dst.error; |
| 2244 | } else { |
| 2245 | rt = ip_route_output_key(net, &fl4); |
| 2246 | |
| 2247 | err = 0; |
| 2248 | if (IS_ERR(rt)) |
| 2249 | err = PTR_ERR(rt); |
| 2250 | } |
| 2251 | |
| 2252 | if (err) |
| 2253 | goto errout_free; |
| 2254 | |
| 2255 | skb_dst_set(skb, &rt->dst); |
| 2256 | if (rtm->rtm_flags & RTM_F_NOTIFY) |
| 2257 | rt->rt_flags |= RTCF_NOTIFY; |
| 2258 | |
| 2259 | err = rt_fill_info(net, dst, src, &fl4, skb, |
| 2260 | NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, |
| 2261 | RTM_NEWROUTE, 0, 0); |
| 2262 | if (err <= 0) |
| 2263 | goto errout_free; |
| 2264 | |
| 2265 | err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); |
| 2266 | errout: |
| 2267 | return err; |
| 2268 | |
| 2269 | errout_free: |
| 2270 | kfree_skb(skb); |
| 2271 | goto errout; |
| 2272 | } |
| 2273 | |
| 2274 | int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) |
| 2275 | { |
| 2276 | return skb->len; |
| 2277 | } |
| 2278 | |
| 2279 | void ip_rt_multicast_event(struct in_device *in_dev) |
| 2280 | { |
| 2281 | rt_cache_flush(dev_net(in_dev->dev), 0); |
| 2282 | } |
| 2283 | |
| 2284 | #ifdef CONFIG_SYSCTL |
| 2285 | static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, |
| 2286 | void __user *buffer, |
| 2287 | size_t *lenp, loff_t *ppos) |
| 2288 | { |
| 2289 | if (write) { |
| 2290 | int flush_delay; |
| 2291 | ctl_table ctl; |
| 2292 | struct net *net; |
| 2293 | |
| 2294 | memcpy(&ctl, __ctl, sizeof(ctl)); |
| 2295 | ctl.data = &flush_delay; |
| 2296 | proc_dointvec(&ctl, write, buffer, lenp, ppos); |
| 2297 | |
| 2298 | net = (struct net *)__ctl->extra1; |
| 2299 | rt_cache_flush(net, flush_delay); |
| 2300 | return 0; |
| 2301 | } |
| 2302 | |
| 2303 | return -EINVAL; |
| 2304 | } |
| 2305 | |
| 2306 | static ctl_table ipv4_route_table[] = { |
| 2307 | { |
| 2308 | .procname = "gc_thresh", |
| 2309 | .data = &ipv4_dst_ops.gc_thresh, |
| 2310 | .maxlen = sizeof(int), |
| 2311 | .mode = 0644, |
| 2312 | .proc_handler = proc_dointvec, |
| 2313 | }, |
| 2314 | { |
| 2315 | .procname = "max_size", |
| 2316 | .data = &ip_rt_max_size, |
| 2317 | .maxlen = sizeof(int), |
| 2318 | .mode = 0644, |
| 2319 | .proc_handler = proc_dointvec, |
| 2320 | }, |
| 2321 | { |
| 2322 | /* Deprecated. Use gc_min_interval_ms */ |
| 2323 | |
| 2324 | .procname = "gc_min_interval", |
| 2325 | .data = &ip_rt_gc_min_interval, |
| 2326 | .maxlen = sizeof(int), |
| 2327 | .mode = 0644, |
| 2328 | .proc_handler = proc_dointvec_jiffies, |
| 2329 | }, |
| 2330 | { |
| 2331 | .procname = "gc_min_interval_ms", |
| 2332 | .data = &ip_rt_gc_min_interval, |
| 2333 | .maxlen = sizeof(int), |
| 2334 | .mode = 0644, |
| 2335 | .proc_handler = proc_dointvec_ms_jiffies, |
| 2336 | }, |
| 2337 | { |
| 2338 | .procname = "gc_timeout", |
| 2339 | .data = &ip_rt_gc_timeout, |
| 2340 | .maxlen = sizeof(int), |
| 2341 | .mode = 0644, |
| 2342 | .proc_handler = proc_dointvec_jiffies, |
| 2343 | }, |
| 2344 | { |
| 2345 | .procname = "gc_interval", |
| 2346 | .data = &ip_rt_gc_interval, |
| 2347 | .maxlen = sizeof(int), |
| 2348 | .mode = 0644, |
| 2349 | .proc_handler = proc_dointvec_jiffies, |
| 2350 | }, |
| 2351 | { |
| 2352 | .procname = "redirect_load", |
| 2353 | .data = &ip_rt_redirect_load, |
| 2354 | .maxlen = sizeof(int), |
| 2355 | .mode = 0644, |
| 2356 | .proc_handler = proc_dointvec, |
| 2357 | }, |
| 2358 | { |
| 2359 | .procname = "redirect_number", |
| 2360 | .data = &ip_rt_redirect_number, |
| 2361 | .maxlen = sizeof(int), |
| 2362 | .mode = 0644, |
| 2363 | .proc_handler = proc_dointvec, |
| 2364 | }, |
| 2365 | { |
| 2366 | .procname = "redirect_silence", |
| 2367 | .data = &ip_rt_redirect_silence, |
| 2368 | .maxlen = sizeof(int), |
| 2369 | .mode = 0644, |
| 2370 | .proc_handler = proc_dointvec, |
| 2371 | }, |
| 2372 | { |
| 2373 | .procname = "error_cost", |
| 2374 | .data = &ip_rt_error_cost, |
| 2375 | .maxlen = sizeof(int), |
| 2376 | .mode = 0644, |
| 2377 | .proc_handler = proc_dointvec, |
| 2378 | }, |
| 2379 | { |
| 2380 | .procname = "error_burst", |
| 2381 | .data = &ip_rt_error_burst, |
| 2382 | .maxlen = sizeof(int), |
| 2383 | .mode = 0644, |
| 2384 | .proc_handler = proc_dointvec, |
| 2385 | }, |
| 2386 | { |
| 2387 | .procname = "gc_elasticity", |
| 2388 | .data = &ip_rt_gc_elasticity, |
| 2389 | .maxlen = sizeof(int), |
| 2390 | .mode = 0644, |
| 2391 | .proc_handler = proc_dointvec, |
| 2392 | }, |
| 2393 | { |
| 2394 | .procname = "mtu_expires", |
| 2395 | .data = &ip_rt_mtu_expires, |
| 2396 | .maxlen = sizeof(int), |
| 2397 | .mode = 0644, |
| 2398 | .proc_handler = proc_dointvec_jiffies, |
| 2399 | }, |
| 2400 | { |
| 2401 | .procname = "min_pmtu", |
| 2402 | .data = &ip_rt_min_pmtu, |
| 2403 | .maxlen = sizeof(int), |
| 2404 | .mode = 0644, |
| 2405 | .proc_handler = proc_dointvec, |
| 2406 | }, |
| 2407 | { |
| 2408 | .procname = "min_adv_mss", |
| 2409 | .data = &ip_rt_min_advmss, |
| 2410 | .maxlen = sizeof(int), |
| 2411 | .mode = 0644, |
| 2412 | .proc_handler = proc_dointvec, |
| 2413 | }, |
| 2414 | { } |
| 2415 | }; |
| 2416 | |
| 2417 | static struct ctl_table ipv4_route_flush_table[] = { |
| 2418 | { |
| 2419 | .procname = "flush", |
| 2420 | .maxlen = sizeof(int), |
| 2421 | .mode = 0200, |
| 2422 | .proc_handler = ipv4_sysctl_rtcache_flush, |
| 2423 | }, |
| 2424 | { }, |
| 2425 | }; |
| 2426 | |
| 2427 | static __net_init int sysctl_route_net_init(struct net *net) |
| 2428 | { |
| 2429 | struct ctl_table *tbl; |
| 2430 | |
| 2431 | tbl = ipv4_route_flush_table; |
| 2432 | if (!net_eq(net, &init_net)) { |
| 2433 | tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); |
| 2434 | if (tbl == NULL) |
| 2435 | goto err_dup; |
| 2436 | } |
| 2437 | tbl[0].extra1 = net; |
| 2438 | |
| 2439 | net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); |
| 2440 | if (net->ipv4.route_hdr == NULL) |
| 2441 | goto err_reg; |
| 2442 | return 0; |
| 2443 | |
| 2444 | err_reg: |
| 2445 | if (tbl != ipv4_route_flush_table) |
| 2446 | kfree(tbl); |
| 2447 | err_dup: |
| 2448 | return -ENOMEM; |
| 2449 | } |
| 2450 | |
| 2451 | static __net_exit void sysctl_route_net_exit(struct net *net) |
| 2452 | { |
| 2453 | struct ctl_table *tbl; |
| 2454 | |
| 2455 | tbl = net->ipv4.route_hdr->ctl_table_arg; |
| 2456 | unregister_net_sysctl_table(net->ipv4.route_hdr); |
| 2457 | BUG_ON(tbl == ipv4_route_flush_table); |
| 2458 | kfree(tbl); |
| 2459 | } |
| 2460 | |
| 2461 | static __net_initdata struct pernet_operations sysctl_route_ops = { |
| 2462 | .init = sysctl_route_net_init, |
| 2463 | .exit = sysctl_route_net_exit, |
| 2464 | }; |
| 2465 | #endif |
| 2466 | |
| 2467 | static __net_init int rt_genid_init(struct net *net) |
| 2468 | { |
| 2469 | get_random_bytes(&net->ipv4.rt_genid, |
| 2470 | sizeof(net->ipv4.rt_genid)); |
| 2471 | get_random_bytes(&net->ipv4.dev_addr_genid, |
| 2472 | sizeof(net->ipv4.dev_addr_genid)); |
| 2473 | return 0; |
| 2474 | } |
| 2475 | |
| 2476 | static __net_initdata struct pernet_operations rt_genid_ops = { |
| 2477 | .init = rt_genid_init, |
| 2478 | }; |
| 2479 | |
| 2480 | static int __net_init ipv4_inetpeer_init(struct net *net) |
| 2481 | { |
| 2482 | struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); |
| 2483 | |
| 2484 | if (!bp) |
| 2485 | return -ENOMEM; |
| 2486 | inet_peer_base_init(bp); |
| 2487 | net->ipv4.peers = bp; |
| 2488 | return 0; |
| 2489 | } |
| 2490 | |
| 2491 | static void __net_exit ipv4_inetpeer_exit(struct net *net) |
| 2492 | { |
| 2493 | struct inet_peer_base *bp = net->ipv4.peers; |
| 2494 | |
| 2495 | net->ipv4.peers = NULL; |
| 2496 | inetpeer_invalidate_tree(bp); |
| 2497 | kfree(bp); |
| 2498 | } |
| 2499 | |
| 2500 | static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { |
| 2501 | .init = ipv4_inetpeer_init, |
| 2502 | .exit = ipv4_inetpeer_exit, |
| 2503 | }; |
| 2504 | |
| 2505 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 2506 | struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; |
| 2507 | #endif /* CONFIG_IP_ROUTE_CLASSID */ |
| 2508 | |
| 2509 | int __init ip_rt_init(void) |
| 2510 | { |
| 2511 | int rc = 0; |
| 2512 | |
| 2513 | #ifdef CONFIG_IP_ROUTE_CLASSID |
| 2514 | ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); |
| 2515 | if (!ip_rt_acct) |
| 2516 | panic("IP: failed to allocate ip_rt_acct\n"); |
| 2517 | #endif |
| 2518 | |
| 2519 | ipv4_dst_ops.kmem_cachep = |
| 2520 | kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, |
| 2521 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
| 2522 | |
| 2523 | ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; |
| 2524 | |
| 2525 | if (dst_entries_init(&ipv4_dst_ops) < 0) |
| 2526 | panic("IP: failed to allocate ipv4_dst_ops counter\n"); |
| 2527 | |
| 2528 | if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) |
| 2529 | panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); |
| 2530 | |
| 2531 | ipv4_dst_ops.gc_thresh = ~0; |
| 2532 | ip_rt_max_size = INT_MAX; |
| 2533 | |
| 2534 | devinet_init(); |
| 2535 | ip_fib_init(); |
| 2536 | |
| 2537 | if (ip_rt_proc_init()) |
| 2538 | pr_err("Unable to create route proc files\n"); |
| 2539 | #ifdef CONFIG_XFRM |
| 2540 | xfrm_init(); |
| 2541 | xfrm4_init(ip_rt_max_size); |
| 2542 | #endif |
| 2543 | rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); |
| 2544 | |
| 2545 | #ifdef CONFIG_SYSCTL |
| 2546 | register_pernet_subsys(&sysctl_route_ops); |
| 2547 | #endif |
| 2548 | register_pernet_subsys(&rt_genid_ops); |
| 2549 | register_pernet_subsys(&ipv4_inetpeer_ops); |
| 2550 | return rc; |
| 2551 | } |
| 2552 | |
| 2553 | #ifdef CONFIG_SYSCTL |
| 2554 | /* |
| 2555 | * We really need to sanitize the damn ipv4 init order, then all |
| 2556 | * this nonsense will go away. |
| 2557 | */ |
| 2558 | void __init ip_static_sysctl_init(void) |
| 2559 | { |
| 2560 | register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); |
| 2561 | } |
| 2562 | #endif |