| /* |
| * INET An implementation of the TCP/IP protocol suite for the LINUX |
| * operating system. INET is implemented using the BSD Socket |
| * interface as the means of communication with the user level. |
| * |
| * ROUTE - implementation of the IP router. |
| * |
| * Authors: Ross Biro |
| * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| * Alan Cox, <gw4pts@gw4pts.ampr.org> |
| * Linus Torvalds, <Linus.Torvalds@helsinki.fi> |
| * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| * |
| * Fixes: |
| * Alan Cox : Verify area fixes. |
| * Alan Cox : cli() protects routing changes |
| * Rui Oliveira : ICMP routing table updates |
| * (rco@di.uminho.pt) Routing table insertion and update |
| * Linus Torvalds : Rewrote bits to be sensible |
| * Alan Cox : Added BSD route gw semantics |
| * Alan Cox : Super /proc >4K |
| * Alan Cox : MTU in route table |
| * Alan Cox : MSS actually. Also added the window |
| * clamper. |
| * Sam Lantinga : Fixed route matching in rt_del() |
| * Alan Cox : Routing cache support. |
| * Alan Cox : Removed compatibility cruft. |
| * Alan Cox : RTF_REJECT support. |
| * Alan Cox : TCP irtt support. |
| * Jonathan Naylor : Added Metric support. |
| * Miquel van Smoorenburg : BSD API fixes. |
| * Miquel van Smoorenburg : Metrics. |
| * Alan Cox : Use __u32 properly |
| * Alan Cox : Aligned routing errors more closely with BSD |
| * our system is still very different. |
| * Alan Cox : Faster /proc handling |
| * Alexey Kuznetsov : Massive rework to support tree based routing, |
| * routing caches and better behaviour. |
| * |
| * Olaf Erb : irtt wasn't being copied right. |
| * Bjorn Ekwall : Kerneld route support. |
| * Alan Cox : Multicast fixed (I hope) |
| * Pavel Krauz : Limited broadcast fixed |
| * Mike McLagan : Routing by source |
| * Alexey Kuznetsov : End of old history. Split to fib.c and |
| * route.c and rewritten from scratch. |
| * Andi Kleen : Load-limit warning messages. |
| * Vitaly E. Lavrov : Transparent proxy revived after year coma. |
| * Vitaly E. Lavrov : Race condition in ip_route_input_slow. |
| * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. |
| * Vladimir V. Ivanov : IP rule info (flowid) is really useful. |
| * Marc Boucher : routing by fwmark |
| * Robert Olsson : Added rt_cache statistics |
| * Arnaldo C. Melo : Convert proc stuff to seq_file |
| * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. |
| * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect |
| * Ilia Sotnikov : Removed TOS from hash calculations |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #define pr_fmt(fmt) "IPv4: " fmt |
| |
| #include <linux/module.h> |
| #include <asm/uaccess.h> |
| #include <linux/bitops.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/string.h> |
| #include <linux/socket.h> |
| #include <linux/sockios.h> |
| #include <linux/errno.h> |
| #include <linux/in.h> |
| #include <linux/inet.h> |
| #include <linux/netdevice.h> |
| #include <linux/proc_fs.h> |
| #include <linux/init.h> |
| #include <linux/skbuff.h> |
| #include <linux/inetdevice.h> |
| #include <linux/igmp.h> |
| #include <linux/pkt_sched.h> |
| #include <linux/mroute.h> |
| #include <linux/netfilter_ipv4.h> |
| #include <linux/random.h> |
| #include <linux/rcupdate.h> |
| #include <linux/times.h> |
| #include <linux/slab.h> |
| #include <net/dst.h> |
| #include <net/net_namespace.h> |
| #include <net/protocol.h> |
| #include <net/ip.h> |
| #include <net/route.h> |
| #include <net/inetpeer.h> |
| #include <net/sock.h> |
| #include <net/ip_fib.h> |
| #include <net/arp.h> |
| #include <net/tcp.h> |
| #include <net/icmp.h> |
| #include <net/xfrm.h> |
| #include <net/netevent.h> |
| #include <net/rtnetlink.h> |
| #ifdef CONFIG_SYSCTL |
| #include <linux/sysctl.h> |
| #include <linux/kmemleak.h> |
| #endif |
| #include <net/secure_seq.h> |
| |
| #define RT_FL_TOS(oldflp4) \ |
| ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) |
| |
| #define IP_MAX_MTU 0xFFF0 |
| |
| #define RT_GC_TIMEOUT (300*HZ) |
| |
| static int ip_rt_max_size; |
| static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; |
| static int ip_rt_gc_interval __read_mostly = 60 * HZ; |
| static int ip_rt_gc_min_interval __read_mostly = HZ / 2; |
| static int ip_rt_redirect_number __read_mostly = 9; |
| static int ip_rt_redirect_load __read_mostly = HZ / 50; |
| static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); |
| static int ip_rt_error_cost __read_mostly = HZ; |
| static int ip_rt_error_burst __read_mostly = 5 * HZ; |
| static int ip_rt_gc_elasticity __read_mostly = 8; |
| static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; |
| static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; |
| static int ip_rt_min_advmss __read_mostly = 256; |
| |
| /* |
| * Interface to generic destination cache. |
| */ |
| |
| static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); |
| static unsigned int ipv4_default_advmss(const struct dst_entry *dst); |
| static unsigned int ipv4_mtu(const struct dst_entry *dst); |
| static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); |
| static void ipv4_link_failure(struct sk_buff *skb); |
| static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, |
| struct sk_buff *skb, u32 mtu); |
| static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, |
| struct sk_buff *skb); |
| static void ipv4_dst_destroy(struct dst_entry *dst); |
| |
| static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, |
| int how) |
| { |
| } |
| |
| static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) |
| { |
| WARN_ON(1); |
| return NULL; |
| } |
| |
| static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, |
| struct sk_buff *skb, |
| const void *daddr); |
| |
| static struct dst_ops ipv4_dst_ops = { |
| .family = AF_INET, |
| .protocol = cpu_to_be16(ETH_P_IP), |
| .check = ipv4_dst_check, |
| .default_advmss = ipv4_default_advmss, |
| .mtu = ipv4_mtu, |
| .cow_metrics = ipv4_cow_metrics, |
| .destroy = ipv4_dst_destroy, |
| .ifdown = ipv4_dst_ifdown, |
| .negative_advice = ipv4_negative_advice, |
| .link_failure = ipv4_link_failure, |
| .update_pmtu = ip_rt_update_pmtu, |
| .redirect = ip_do_redirect, |
| .local_out = __ip_local_out, |
| .neigh_lookup = ipv4_neigh_lookup, |
| }; |
| |
| #define ECN_OR_COST(class) TC_PRIO_##class |
| |
| const __u8 ip_tos2prio[16] = { |
| TC_PRIO_BESTEFFORT, |
| ECN_OR_COST(BESTEFFORT), |
| TC_PRIO_BESTEFFORT, |
| ECN_OR_COST(BESTEFFORT), |
| TC_PRIO_BULK, |
| ECN_OR_COST(BULK), |
| TC_PRIO_BULK, |
| ECN_OR_COST(BULK), |
| TC_PRIO_INTERACTIVE, |
| ECN_OR_COST(INTERACTIVE), |
| TC_PRIO_INTERACTIVE, |
| ECN_OR_COST(INTERACTIVE), |
| TC_PRIO_INTERACTIVE_BULK, |
| ECN_OR_COST(INTERACTIVE_BULK), |
| TC_PRIO_INTERACTIVE_BULK, |
| ECN_OR_COST(INTERACTIVE_BULK) |
| }; |
| EXPORT_SYMBOL(ip_tos2prio); |
| |
| static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); |
| #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) |
| |
| static inline int rt_genid(struct net *net) |
| { |
| return atomic_read(&net->ipv4.rt_genid); |
| } |
| |
| #ifdef CONFIG_PROC_FS |
| static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| if (*pos) |
| return NULL; |
| return SEQ_START_TOKEN; |
| } |
| |
| static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| ++*pos; |
| return NULL; |
| } |
| |
| static void rt_cache_seq_stop(struct seq_file *seq, void *v) |
| { |
| } |
| |
| static int rt_cache_seq_show(struct seq_file *seq, void *v) |
| { |
| if (v == SEQ_START_TOKEN) |
| seq_printf(seq, "%-127s\n", |
| "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" |
| "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" |
| "HHUptod\tSpecDst"); |
| return 0; |
| } |
| |
| static const struct seq_operations rt_cache_seq_ops = { |
| .start = rt_cache_seq_start, |
| .next = rt_cache_seq_next, |
| .stop = rt_cache_seq_stop, |
| .show = rt_cache_seq_show, |
| }; |
| |
| static int rt_cache_seq_open(struct inode *inode, struct file *file) |
| { |
| return seq_open(file, &rt_cache_seq_ops); |
| } |
| |
| static const struct file_operations rt_cache_seq_fops = { |
| .owner = THIS_MODULE, |
| .open = rt_cache_seq_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| |
| static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| int cpu; |
| |
| if (*pos == 0) |
| return SEQ_START_TOKEN; |
| |
| for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { |
| if (!cpu_possible(cpu)) |
| continue; |
| *pos = cpu+1; |
| return &per_cpu(rt_cache_stat, cpu); |
| } |
| return NULL; |
| } |
| |
| static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| int cpu; |
| |
| for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { |
| if (!cpu_possible(cpu)) |
| continue; |
| *pos = cpu+1; |
| return &per_cpu(rt_cache_stat, cpu); |
| } |
| return NULL; |
| |
| } |
| |
| static void rt_cpu_seq_stop(struct seq_file *seq, void *v) |
| { |
| |
| } |
| |
| static int rt_cpu_seq_show(struct seq_file *seq, void *v) |
| { |
| struct rt_cache_stat *st = v; |
| |
| if (v == SEQ_START_TOKEN) { |
| 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"); |
| return 0; |
| } |
| |
| seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " |
| " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", |
| dst_entries_get_slow(&ipv4_dst_ops), |
| st->in_hit, |
| st->in_slow_tot, |
| st->in_slow_mc, |
| st->in_no_route, |
| st->in_brd, |
| st->in_martian_dst, |
| st->in_martian_src, |
| |
| st->out_hit, |
| st->out_slow_tot, |
| st->out_slow_mc, |
| |
| st->gc_total, |
| st->gc_ignored, |
| st->gc_goal_miss, |
| st->gc_dst_overflow, |
| st->in_hlist_search, |
| st->out_hlist_search |
| ); |
| return 0; |
| } |
| |
| static const struct seq_operations rt_cpu_seq_ops = { |
| .start = rt_cpu_seq_start, |
| .next = rt_cpu_seq_next, |
| .stop = rt_cpu_seq_stop, |
| .show = rt_cpu_seq_show, |
| }; |
| |
| |
| static int rt_cpu_seq_open(struct inode *inode, struct file *file) |
| { |
| return seq_open(file, &rt_cpu_seq_ops); |
| } |
| |
| static const struct file_operations rt_cpu_seq_fops = { |
| .owner = THIS_MODULE, |
| .open = rt_cpu_seq_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| static int rt_acct_proc_show(struct seq_file *m, void *v) |
| { |
| struct ip_rt_acct *dst, *src; |
| unsigned int i, j; |
| |
| dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); |
| if (!dst) |
| return -ENOMEM; |
| |
| for_each_possible_cpu(i) { |
| src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); |
| for (j = 0; j < 256; j++) { |
| dst[j].o_bytes += src[j].o_bytes; |
| dst[j].o_packets += src[j].o_packets; |
| dst[j].i_bytes += src[j].i_bytes; |
| dst[j].i_packets += src[j].i_packets; |
| } |
| } |
| |
| seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); |
| kfree(dst); |
| return 0; |
| } |
| |
| static int rt_acct_proc_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, rt_acct_proc_show, NULL); |
| } |
| |
| static const struct file_operations rt_acct_proc_fops = { |
| .owner = THIS_MODULE, |
| .open = rt_acct_proc_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| }; |
| #endif |
| |
| static int __net_init ip_rt_do_proc_init(struct net *net) |
| { |
| struct proc_dir_entry *pde; |
| |
| pde = proc_net_fops_create(net, "rt_cache", S_IRUGO, |
| &rt_cache_seq_fops); |
| if (!pde) |
| goto err1; |
| |
| pde = proc_create("rt_cache", S_IRUGO, |
| net->proc_net_stat, &rt_cpu_seq_fops); |
| if (!pde) |
| goto err2; |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); |
| if (!pde) |
| goto err3; |
| #endif |
| return 0; |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| err3: |
| remove_proc_entry("rt_cache", net->proc_net_stat); |
| #endif |
| err2: |
| remove_proc_entry("rt_cache", net->proc_net); |
| err1: |
| return -ENOMEM; |
| } |
| |
| static void __net_exit ip_rt_do_proc_exit(struct net *net) |
| { |
| remove_proc_entry("rt_cache", net->proc_net_stat); |
| remove_proc_entry("rt_cache", net->proc_net); |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| remove_proc_entry("rt_acct", net->proc_net); |
| #endif |
| } |
| |
| static struct pernet_operations ip_rt_proc_ops __net_initdata = { |
| .init = ip_rt_do_proc_init, |
| .exit = ip_rt_do_proc_exit, |
| }; |
| |
| static int __init ip_rt_proc_init(void) |
| { |
| return register_pernet_subsys(&ip_rt_proc_ops); |
| } |
| |
| #else |
| static inline int ip_rt_proc_init(void) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_PROC_FS */ |
| |
| static inline bool rt_is_expired(const struct rtable *rth) |
| { |
| return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); |
| } |
| |
| /* |
| * Perturbation of rt_genid by a small quantity [1..256] |
| * Using 8 bits of shuffling ensure we can call rt_cache_invalidate() |
| * many times (2^24) without giving recent rt_genid. |
| * Jenkins hash is strong enough that litle changes of rt_genid are OK. |
| */ |
| static void rt_cache_invalidate(struct net *net) |
| { |
| unsigned char shuffle; |
| |
| get_random_bytes(&shuffle, sizeof(shuffle)); |
| atomic_add(shuffle + 1U, &net->ipv4.rt_genid); |
| } |
| |
| /* |
| * delay < 0 : invalidate cache (fast : entries will be deleted later) |
| * delay >= 0 : invalidate & flush cache (can be long) |
| */ |
| void rt_cache_flush(struct net *net, int delay) |
| { |
| rt_cache_invalidate(net); |
| } |
| |
| static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, |
| struct sk_buff *skb, |
| const void *daddr) |
| { |
| struct net_device *dev = dst->dev; |
| const __be32 *pkey = daddr; |
| const struct rtable *rt; |
| struct neighbour *n; |
| |
| rt = (const struct rtable *) dst; |
| if (rt->rt_gateway) |
| pkey = (const __be32 *) &rt->rt_gateway; |
| else if (skb) |
| pkey = &ip_hdr(skb)->daddr; |
| |
| n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); |
| if (n) |
| return n; |
| return neigh_create(&arp_tbl, pkey, dev); |
| } |
| |
| /* |
| * Peer allocation may fail only in serious out-of-memory conditions. However |
| * we still can generate some output. |
| * Random ID selection looks a bit dangerous because we have no chances to |
| * select ID being unique in a reasonable period of time. |
| * But broken packet identifier may be better than no packet at all. |
| */ |
| static void ip_select_fb_ident(struct iphdr *iph) |
| { |
| static DEFINE_SPINLOCK(ip_fb_id_lock); |
| static u32 ip_fallback_id; |
| u32 salt; |
| |
| spin_lock_bh(&ip_fb_id_lock); |
| salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr); |
| iph->id = htons(salt & 0xFFFF); |
| ip_fallback_id = salt; |
| spin_unlock_bh(&ip_fb_id_lock); |
| } |
| |
| void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more) |
| { |
| struct net *net = dev_net(dst->dev); |
| struct inet_peer *peer; |
| |
| peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1); |
| if (peer) { |
| iph->id = htons(inet_getid(peer, more)); |
| inet_putpeer(peer); |
| return; |
| } |
| |
| ip_select_fb_ident(iph); |
| } |
| EXPORT_SYMBOL(__ip_select_ident); |
| |
| static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk, |
| const struct iphdr *iph, |
| int oif, u8 tos, |
| u8 prot, u32 mark, int flow_flags) |
| { |
| if (sk) { |
| const struct inet_sock *inet = inet_sk(sk); |
| |
| oif = sk->sk_bound_dev_if; |
| mark = sk->sk_mark; |
| tos = RT_CONN_FLAGS(sk); |
| prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; |
| } |
| flowi4_init_output(fl4, oif, mark, tos, |
| RT_SCOPE_UNIVERSE, prot, |
| flow_flags, |
| iph->daddr, iph->saddr, 0, 0); |
| } |
| |
| static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, |
| const struct sock *sk) |
| { |
| const struct iphdr *iph = ip_hdr(skb); |
| int oif = skb->dev->ifindex; |
| u8 tos = RT_TOS(iph->tos); |
| u8 prot = iph->protocol; |
| u32 mark = skb->mark; |
| |
| __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0); |
| } |
| |
| static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) |
| { |
| const struct inet_sock *inet = inet_sk(sk); |
| const struct ip_options_rcu *inet_opt; |
| __be32 daddr = inet->inet_daddr; |
| |
| rcu_read_lock(); |
| inet_opt = rcu_dereference(inet->inet_opt); |
| if (inet_opt && inet_opt->opt.srr) |
| daddr = inet_opt->opt.faddr; |
| flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, |
| RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, |
| inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, |
| inet_sk_flowi_flags(sk), |
| daddr, inet->inet_saddr, 0, 0); |
| rcu_read_unlock(); |
| } |
| |
| static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, |
| const struct sk_buff *skb) |
| { |
| if (skb) |
| build_skb_flow_key(fl4, skb, sk); |
| else |
| build_sk_flow_key(fl4, sk); |
| } |
| |
| static inline void rt_free(struct rtable *rt) |
| { |
| call_rcu(&rt->dst.rcu_head, dst_rcu_free); |
| } |
| |
| static DEFINE_SPINLOCK(fnhe_lock); |
| |
| static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) |
| { |
| struct fib_nh_exception *fnhe, *oldest; |
| struct rtable *orig; |
| |
| oldest = rcu_dereference(hash->chain); |
| for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; |
| fnhe = rcu_dereference(fnhe->fnhe_next)) { |
| if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) |
| oldest = fnhe; |
| } |
| orig = rcu_dereference(oldest->fnhe_rth); |
| if (orig) { |
| RCU_INIT_POINTER(oldest->fnhe_rth, NULL); |
| rt_free(orig); |
| } |
| return oldest; |
| } |
| |
| static inline u32 fnhe_hashfun(__be32 daddr) |
| { |
| u32 hval; |
| |
| hval = (__force u32) daddr; |
| hval ^= (hval >> 11) ^ (hval >> 22); |
| |
| return hval & (FNHE_HASH_SIZE - 1); |
| } |
| |
| static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, |
| u32 pmtu, unsigned long expires) |
| { |
| struct fnhe_hash_bucket *hash; |
| struct fib_nh_exception *fnhe; |
| int depth; |
| u32 hval = fnhe_hashfun(daddr); |
| |
| spin_lock_bh(&fnhe_lock); |
| |
| hash = nh->nh_exceptions; |
| if (!hash) { |
| hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC); |
| if (!hash) |
| goto out_unlock; |
| nh->nh_exceptions = hash; |
| } |
| |
| hash += hval; |
| |
| depth = 0; |
| for (fnhe = rcu_dereference(hash->chain); fnhe; |
| fnhe = rcu_dereference(fnhe->fnhe_next)) { |
| if (fnhe->fnhe_daddr == daddr) |
| break; |
| depth++; |
| } |
| |
| if (fnhe) { |
| if (gw) |
| fnhe->fnhe_gw = gw; |
| if (pmtu) { |
| fnhe->fnhe_pmtu = pmtu; |
| fnhe->fnhe_expires = expires; |
| } |
| } else { |
| if (depth > FNHE_RECLAIM_DEPTH) |
| fnhe = fnhe_oldest(hash); |
| else { |
| fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); |
| if (!fnhe) |
| goto out_unlock; |
| |
| fnhe->fnhe_next = hash->chain; |
| rcu_assign_pointer(hash->chain, fnhe); |
| } |
| fnhe->fnhe_daddr = daddr; |
| fnhe->fnhe_gw = gw; |
| fnhe->fnhe_pmtu = pmtu; |
| fnhe->fnhe_expires = expires; |
| } |
| |
| fnhe->fnhe_stamp = jiffies; |
| |
| out_unlock: |
| spin_unlock_bh(&fnhe_lock); |
| return; |
| } |
| |
| static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, |
| bool kill_route) |
| { |
| __be32 new_gw = icmp_hdr(skb)->un.gateway; |
| __be32 old_gw = ip_hdr(skb)->saddr; |
| struct net_device *dev = skb->dev; |
| struct in_device *in_dev; |
| struct fib_result res; |
| struct neighbour *n; |
| struct net *net; |
| |
| switch (icmp_hdr(skb)->code & 7) { |
| case ICMP_REDIR_NET: |
| case ICMP_REDIR_NETTOS: |
| case ICMP_REDIR_HOST: |
| case ICMP_REDIR_HOSTTOS: |
| break; |
| |
| default: |
| return; |
| } |
| |
| if (rt->rt_gateway != old_gw) |
| return; |
| |
| in_dev = __in_dev_get_rcu(dev); |
| if (!in_dev) |
| return; |
| |
| net = dev_net(dev); |
| if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || |
| ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || |
| ipv4_is_zeronet(new_gw)) |
| goto reject_redirect; |
| |
| if (!IN_DEV_SHARED_MEDIA(in_dev)) { |
| if (!inet_addr_onlink(in_dev, new_gw, old_gw)) |
| goto reject_redirect; |
| if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) |
| goto reject_redirect; |
| } else { |
| if (inet_addr_type(net, new_gw) != RTN_UNICAST) |
| goto reject_redirect; |
| } |
| |
| n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw); |
| if (n) { |
| if (!(n->nud_state & NUD_VALID)) { |
| neigh_event_send(n, NULL); |
| } else { |
| if (fib_lookup(net, fl4, &res) == 0) { |
| struct fib_nh *nh = &FIB_RES_NH(res); |
| |
| update_or_create_fnhe(nh, fl4->daddr, new_gw, |
| 0, 0); |
| } |
| if (kill_route) |
| rt->dst.obsolete = DST_OBSOLETE_KILL; |
| call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); |
| } |
| neigh_release(n); |
| } |
| return; |
| |
| reject_redirect: |
| #ifdef CONFIG_IP_ROUTE_VERBOSE |
| if (IN_DEV_LOG_MARTIANS(in_dev)) { |
| const struct iphdr *iph = (const struct iphdr *) skb->data; |
| __be32 daddr = iph->daddr; |
| __be32 saddr = iph->saddr; |
| |
| net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" |
| " Advised path = %pI4 -> %pI4\n", |
| &old_gw, dev->name, &new_gw, |
| &saddr, &daddr); |
| } |
| #endif |
| ; |
| } |
| |
| static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) |
| { |
| struct rtable *rt; |
| struct flowi4 fl4; |
| |
| rt = (struct rtable *) dst; |
| |
| ip_rt_build_flow_key(&fl4, sk, skb); |
| __ip_do_redirect(rt, skb, &fl4, true); |
| } |
| |
| static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) |
| { |
| struct rtable *rt = (struct rtable *)dst; |
| struct dst_entry *ret = dst; |
| |
| if (rt) { |
| if (dst->obsolete > 0) { |
| ip_rt_put(rt); |
| ret = NULL; |
| } else if ((rt->rt_flags & RTCF_REDIRECTED) || |
| rt->dst.expires) { |
| ip_rt_put(rt); |
| ret = NULL; |
| } |
| } |
| return ret; |
| } |
| |
| /* |
| * Algorithm: |
| * 1. The first ip_rt_redirect_number redirects are sent |
| * with exponential backoff, then we stop sending them at all, |
| * assuming that the host ignores our redirects. |
| * 2. If we did not see packets requiring redirects |
| * during ip_rt_redirect_silence, we assume that the host |
| * forgot redirected route and start to send redirects again. |
| * |
| * This algorithm is much cheaper and more intelligent than dumb load limiting |
| * in icmp.c. |
| * |
| * NOTE. Do not forget to inhibit load limiting for redirects (redundant) |
| * and "frag. need" (breaks PMTU discovery) in icmp.c. |
| */ |
| |
| void ip_rt_send_redirect(struct sk_buff *skb) |
| { |
| struct rtable *rt = skb_rtable(skb); |
| struct in_device *in_dev; |
| struct inet_peer *peer; |
| struct net *net; |
| int log_martians; |
| |
| rcu_read_lock(); |
| in_dev = __in_dev_get_rcu(rt->dst.dev); |
| if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { |
| rcu_read_unlock(); |
| return; |
| } |
| log_martians = IN_DEV_LOG_MARTIANS(in_dev); |
| rcu_read_unlock(); |
| |
| net = dev_net(rt->dst.dev); |
| peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); |
| if (!peer) { |
| icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); |
| return; |
| } |
| |
| /* No redirected packets during ip_rt_redirect_silence; |
| * reset the algorithm. |
| */ |
| if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) |
| peer->rate_tokens = 0; |
| |
| /* Too many ignored redirects; do not send anything |
| * set dst.rate_last to the last seen redirected packet. |
| */ |
| if (peer->rate_tokens >= ip_rt_redirect_number) { |
| peer->rate_last = jiffies; |
| goto out_put_peer; |
| } |
| |
| /* Check for load limit; set rate_last to the latest sent |
| * redirect. |
| */ |
| if (peer->rate_tokens == 0 || |
| time_after(jiffies, |
| (peer->rate_last + |
| (ip_rt_redirect_load << peer->rate_tokens)))) { |
| icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); |
| peer->rate_last = jiffies; |
| ++peer->rate_tokens; |
| #ifdef CONFIG_IP_ROUTE_VERBOSE |
| if (log_martians && |
| peer->rate_tokens == ip_rt_redirect_number) |
| net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", |
| &ip_hdr(skb)->saddr, inet_iif(skb), |
| &ip_hdr(skb)->daddr, &rt->rt_gateway); |
| #endif |
| } |
| out_put_peer: |
| inet_putpeer(peer); |
| } |
| |
| static int ip_error(struct sk_buff *skb) |
| { |
| struct in_device *in_dev = __in_dev_get_rcu(skb->dev); |
| struct rtable *rt = skb_rtable(skb); |
| struct inet_peer *peer; |
| unsigned long now; |
| struct net *net; |
| bool send; |
| int code; |
| |
| net = dev_net(rt->dst.dev); |
| if (!IN_DEV_FORWARD(in_dev)) { |
| switch (rt->dst.error) { |
| case EHOSTUNREACH: |
| IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS); |
| break; |
| |
| case ENETUNREACH: |
| IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); |
| break; |
| } |
| goto out; |
| } |
| |
| switch (rt->dst.error) { |
| case EINVAL: |
| default: |
| goto out; |
| case EHOSTUNREACH: |
| code = ICMP_HOST_UNREACH; |
| break; |
| case ENETUNREACH: |
| code = ICMP_NET_UNREACH; |
| IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); |
| break; |
| case EACCES: |
| code = ICMP_PKT_FILTERED; |
| break; |
| } |
| |
| peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); |
| |
| send = true; |
| if (peer) { |
| now = jiffies; |
| peer->rate_tokens += now - peer->rate_last; |
| if (peer->rate_tokens > ip_rt_error_burst) |
| peer->rate_tokens = ip_rt_error_burst; |
| peer->rate_last = now; |
| if (peer->rate_tokens >= ip_rt_error_cost) |
| peer->rate_tokens -= ip_rt_error_cost; |
| else |
| send = false; |
| inet_putpeer(peer); |
| } |
| if (send) |
| icmp_send(skb, ICMP_DEST_UNREACH, code, 0); |
| |
| out: kfree_skb(skb); |
| return 0; |
| } |
| |
| static u32 __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) |
| { |
| struct fib_result res; |
| |
| if (mtu < ip_rt_min_pmtu) |
| mtu = ip_rt_min_pmtu; |
| |
| if (fib_lookup(dev_net(rt->dst.dev), fl4, &res) == 0) { |
| struct fib_nh *nh = &FIB_RES_NH(res); |
| |
| update_or_create_fnhe(nh, fl4->daddr, 0, mtu, |
| jiffies + ip_rt_mtu_expires); |
| } |
| return mtu; |
| } |
| |
| static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, |
| struct sk_buff *skb, u32 mtu) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| struct flowi4 fl4; |
| |
| ip_rt_build_flow_key(&fl4, sk, skb); |
| mtu = __ip_rt_update_pmtu(rt, &fl4, mtu); |
| |
| if (!rt->rt_pmtu) { |
| dst->obsolete = DST_OBSOLETE_KILL; |
| } else { |
| rt->rt_pmtu = mtu; |
| rt->dst.expires = max(1UL, jiffies + ip_rt_mtu_expires); |
| } |
| } |
| |
| void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, |
| int oif, u32 mark, u8 protocol, int flow_flags) |
| { |
| const struct iphdr *iph = (const struct iphdr *) skb->data; |
| struct flowi4 fl4; |
| struct rtable *rt; |
| |
| __build_flow_key(&fl4, NULL, iph, oif, |
| RT_TOS(iph->tos), protocol, mark, flow_flags); |
| rt = __ip_route_output_key(net, &fl4); |
| if (!IS_ERR(rt)) { |
| __ip_rt_update_pmtu(rt, &fl4, mtu); |
| ip_rt_put(rt); |
| } |
| } |
| EXPORT_SYMBOL_GPL(ipv4_update_pmtu); |
| |
| void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) |
| { |
| const struct iphdr *iph = (const struct iphdr *) skb->data; |
| struct flowi4 fl4; |
| struct rtable *rt; |
| |
| __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); |
| rt = __ip_route_output_key(sock_net(sk), &fl4); |
| if (!IS_ERR(rt)) { |
| __ip_rt_update_pmtu(rt, &fl4, mtu); |
| ip_rt_put(rt); |
| } |
| } |
| EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); |
| |
| void ipv4_redirect(struct sk_buff *skb, struct net *net, |
| int oif, u32 mark, u8 protocol, int flow_flags) |
| { |
| const struct iphdr *iph = (const struct iphdr *) skb->data; |
| struct flowi4 fl4; |
| struct rtable *rt; |
| |
| __build_flow_key(&fl4, NULL, iph, oif, |
| RT_TOS(iph->tos), protocol, mark, flow_flags); |
| rt = __ip_route_output_key(net, &fl4); |
| if (!IS_ERR(rt)) { |
| __ip_do_redirect(rt, skb, &fl4, false); |
| ip_rt_put(rt); |
| } |
| } |
| EXPORT_SYMBOL_GPL(ipv4_redirect); |
| |
| void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) |
| { |
| const struct iphdr *iph = (const struct iphdr *) skb->data; |
| struct flowi4 fl4; |
| struct rtable *rt; |
| |
| __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); |
| rt = __ip_route_output_key(sock_net(sk), &fl4); |
| if (!IS_ERR(rt)) { |
| __ip_do_redirect(rt, skb, &fl4, false); |
| ip_rt_put(rt); |
| } |
| } |
| EXPORT_SYMBOL_GPL(ipv4_sk_redirect); |
| |
| static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| |
| /* All IPV4 dsts are created with ->obsolete set to the value |
| * DST_OBSOLETE_FORCE_CHK which forces validation calls down |
| * into this function always. |
| * |
| * When a PMTU/redirect information update invalidates a |
| * route, this is indicated by setting obsolete to |
| * DST_OBSOLETE_KILL. |
| */ |
| if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt)) |
| return NULL; |
| return dst; |
| } |
| |
| static void ipv4_link_failure(struct sk_buff *skb) |
| { |
| struct rtable *rt; |
| |
| icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); |
| |
| rt = skb_rtable(skb); |
| if (rt) |
| dst_set_expires(&rt->dst, 0); |
| } |
| |
| static int ip_rt_bug(struct sk_buff *skb) |
| { |
| pr_debug("%s: %pI4 -> %pI4, %s\n", |
| __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, |
| skb->dev ? skb->dev->name : "?"); |
| kfree_skb(skb); |
| WARN_ON(1); |
| return 0; |
| } |
| |
| /* |
| We do not cache source address of outgoing interface, |
| because it is used only by IP RR, TS and SRR options, |
| so that it out of fast path. |
| |
| BTW remember: "addr" is allowed to be not aligned |
| in IP options! |
| */ |
| |
| void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) |
| { |
| __be32 src; |
| |
| if (rt_is_output_route(rt)) |
| src = ip_hdr(skb)->saddr; |
| else { |
| struct fib_result res; |
| struct flowi4 fl4; |
| struct iphdr *iph; |
| |
| iph = ip_hdr(skb); |
| |
| memset(&fl4, 0, sizeof(fl4)); |
| fl4.daddr = iph->daddr; |
| fl4.saddr = iph->saddr; |
| fl4.flowi4_tos = RT_TOS(iph->tos); |
| fl4.flowi4_oif = rt->dst.dev->ifindex; |
| fl4.flowi4_iif = skb->dev->ifindex; |
| fl4.flowi4_mark = skb->mark; |
| |
| rcu_read_lock(); |
| if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) |
| src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); |
| else |
| src = inet_select_addr(rt->dst.dev, |
| rt_nexthop(rt, iph->daddr), |
| RT_SCOPE_UNIVERSE); |
| rcu_read_unlock(); |
| } |
| memcpy(addr, &src, 4); |
| } |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| static void set_class_tag(struct rtable *rt, u32 tag) |
| { |
| if (!(rt->dst.tclassid & 0xFFFF)) |
| rt->dst.tclassid |= tag & 0xFFFF; |
| if (!(rt->dst.tclassid & 0xFFFF0000)) |
| rt->dst.tclassid |= tag & 0xFFFF0000; |
| } |
| #endif |
| |
| static unsigned int ipv4_default_advmss(const struct dst_entry *dst) |
| { |
| unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); |
| |
| if (advmss == 0) { |
| advmss = max_t(unsigned int, dst->dev->mtu - 40, |
| ip_rt_min_advmss); |
| if (advmss > 65535 - 40) |
| advmss = 65535 - 40; |
| } |
| return advmss; |
| } |
| |
| static unsigned int ipv4_mtu(const struct dst_entry *dst) |
| { |
| const struct rtable *rt = (const struct rtable *) dst; |
| unsigned int mtu = rt->rt_pmtu; |
| |
| if (mtu && time_after_eq(jiffies, rt->dst.expires)) |
| mtu = 0; |
| |
| if (!mtu) |
| mtu = dst_metric_raw(dst, RTAX_MTU); |
| |
| if (mtu && rt_is_output_route(rt)) |
| return mtu; |
| |
| mtu = dst->dev->mtu; |
| |
| if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { |
| if (rt->rt_gateway && mtu > 576) |
| mtu = 576; |
| } |
| |
| if (mtu > IP_MAX_MTU) |
| mtu = IP_MAX_MTU; |
| |
| return mtu; |
| } |
| |
| static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) |
| { |
| struct fnhe_hash_bucket *hash = nh->nh_exceptions; |
| struct fib_nh_exception *fnhe; |
| u32 hval; |
| |
| if (!hash) |
| return NULL; |
| |
| hval = fnhe_hashfun(daddr); |
| |
| for (fnhe = rcu_dereference(hash[hval].chain); fnhe; |
| fnhe = rcu_dereference(fnhe->fnhe_next)) { |
| if (fnhe->fnhe_daddr == daddr) |
| return fnhe; |
| } |
| return NULL; |
| } |
| |
| static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, |
| __be32 daddr) |
| { |
| bool ret = false; |
| |
| spin_lock_bh(&fnhe_lock); |
| |
| if (daddr == fnhe->fnhe_daddr) { |
| struct rtable *orig; |
| |
| if (fnhe->fnhe_pmtu) { |
| unsigned long expires = fnhe->fnhe_expires; |
| unsigned long diff = expires - jiffies; |
| |
| if (time_before(jiffies, expires)) { |
| rt->rt_pmtu = fnhe->fnhe_pmtu; |
| dst_set_expires(&rt->dst, diff); |
| } |
| } |
| if (fnhe->fnhe_gw) { |
| rt->rt_flags |= RTCF_REDIRECTED; |
| rt->rt_gateway = fnhe->fnhe_gw; |
| } |
| |
| orig = rcu_dereference(fnhe->fnhe_rth); |
| rcu_assign_pointer(fnhe->fnhe_rth, rt); |
| if (orig) |
| rt_free(orig); |
| |
| fnhe->fnhe_stamp = jiffies; |
| ret = true; |
| } else { |
| /* Routes we intend to cache in nexthop exception have |
| * the DST_NOCACHE bit clear. However, if we are |
| * unsuccessful at storing this route into the cache |
| * we really need to set it. |
| */ |
| rt->dst.flags |= DST_NOCACHE; |
| } |
| spin_unlock_bh(&fnhe_lock); |
| |
| return ret; |
| } |
| |
| static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) |
| { |
| struct rtable *orig, *prev, **p; |
| bool ret = true; |
| |
| if (rt_is_input_route(rt)) { |
| p = (struct rtable **)&nh->nh_rth_input; |
| } else { |
| if (!nh->nh_pcpu_rth_output) |
| goto nocache; |
| p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output); |
| } |
| orig = *p; |
| |
| prev = cmpxchg(p, orig, rt); |
| if (prev == orig) { |
| if (orig) |
| rt_free(orig); |
| } else { |
| /* Routes we intend to cache in the FIB nexthop have |
| * the DST_NOCACHE bit clear. However, if we are |
| * unsuccessful at storing this route into the cache |
| * we really need to set it. |
| */ |
| nocache: |
| rt->dst.flags |= DST_NOCACHE; |
| ret = false; |
| } |
| |
| return ret; |
| } |
| |
| static DEFINE_SPINLOCK(rt_uncached_lock); |
| static LIST_HEAD(rt_uncached_list); |
| |
| static void rt_add_uncached_list(struct rtable *rt) |
| { |
| spin_lock_bh(&rt_uncached_lock); |
| list_add_tail(&rt->rt_uncached, &rt_uncached_list); |
| spin_unlock_bh(&rt_uncached_lock); |
| } |
| |
| static void ipv4_dst_destroy(struct dst_entry *dst) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| |
| if (!list_empty(&rt->rt_uncached)) { |
| spin_lock_bh(&rt_uncached_lock); |
| list_del(&rt->rt_uncached); |
| spin_unlock_bh(&rt_uncached_lock); |
| } |
| } |
| |
| void rt_flush_dev(struct net_device *dev) |
| { |
| if (!list_empty(&rt_uncached_list)) { |
| struct net *net = dev_net(dev); |
| struct rtable *rt; |
| |
| spin_lock_bh(&rt_uncached_lock); |
| list_for_each_entry(rt, &rt_uncached_list, rt_uncached) { |
| if (rt->dst.dev != dev) |
| continue; |
| rt->dst.dev = net->loopback_dev; |
| dev_hold(rt->dst.dev); |
| dev_put(dev); |
| } |
| spin_unlock_bh(&rt_uncached_lock); |
| } |
| } |
| |
| static bool rt_cache_valid(const struct rtable *rt) |
| { |
| return rt && |
| rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && |
| !rt_is_expired(rt); |
| } |
| |
| static void rt_set_nexthop(struct rtable *rt, __be32 daddr, |
| const struct fib_result *res, |
| struct fib_nh_exception *fnhe, |
| struct fib_info *fi, u16 type, u32 itag) |
| { |
| bool cached = false; |
| |
| if (fi) { |
| struct fib_nh *nh = &FIB_RES_NH(*res); |
| |
| if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) |
| rt->rt_gateway = nh->nh_gw; |
| dst_init_metrics(&rt->dst, fi->fib_metrics, true); |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| rt->dst.tclassid = nh->nh_tclassid; |
| #endif |
| if (unlikely(fnhe)) |
| cached = rt_bind_exception(rt, fnhe, daddr); |
| else if (!(rt->dst.flags & DST_NOCACHE)) |
| cached = rt_cache_route(nh, rt); |
| } |
| if (unlikely(!cached)) |
| rt_add_uncached_list(rt); |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| #ifdef CONFIG_IP_MULTIPLE_TABLES |
| set_class_tag(rt, res->tclassid); |
| #endif |
| set_class_tag(rt, itag); |
| #endif |
| } |
| |
| static struct rtable *rt_dst_alloc(struct net_device *dev, |
| bool nopolicy, bool noxfrm, bool will_cache) |
| { |
| return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, |
| (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | |
| (nopolicy ? DST_NOPOLICY : 0) | |
| (noxfrm ? DST_NOXFRM : 0)); |
| } |
| |
| /* called in rcu_read_lock() section */ |
| static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| u8 tos, struct net_device *dev, int our) |
| { |
| struct rtable *rth; |
| struct in_device *in_dev = __in_dev_get_rcu(dev); |
| u32 itag = 0; |
| int err; |
| |
| /* Primary sanity checks. */ |
| |
| if (in_dev == NULL) |
| return -EINVAL; |
| |
| if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || |
| skb->protocol != htons(ETH_P_IP)) |
| goto e_inval; |
| |
| if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) |
| if (ipv4_is_loopback(saddr)) |
| goto e_inval; |
| |
| if (ipv4_is_zeronet(saddr)) { |
| if (!ipv4_is_local_multicast(daddr)) |
| goto e_inval; |
| } else { |
| err = fib_validate_source(skb, saddr, 0, tos, 0, dev, |
| in_dev, &itag); |
| if (err < 0) |
| goto e_err; |
| } |
| rth = rt_dst_alloc(dev_net(dev)->loopback_dev, |
| IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); |
| if (!rth) |
| goto e_nobufs; |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| rth->dst.tclassid = itag; |
| #endif |
| rth->dst.output = ip_rt_bug; |
| |
| rth->rt_genid = rt_genid(dev_net(dev)); |
| rth->rt_flags = RTCF_MULTICAST; |
| rth->rt_type = RTN_MULTICAST; |
| rth->rt_is_input= 1; |
| rth->rt_iif = 0; |
| rth->rt_pmtu = 0; |
| rth->rt_gateway = 0; |
| INIT_LIST_HEAD(&rth->rt_uncached); |
| if (our) { |
| rth->dst.input= ip_local_deliver; |
| rth->rt_flags |= RTCF_LOCAL; |
| } |
| |
| #ifdef CONFIG_IP_MROUTE |
| if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) |
| rth->dst.input = ip_mr_input; |
| #endif |
| RT_CACHE_STAT_INC(in_slow_mc); |
| |
| skb_dst_set(skb, &rth->dst); |
| return 0; |
| |
| e_nobufs: |
| return -ENOBUFS; |
| e_inval: |
| return -EINVAL; |
| e_err: |
| return err; |
| } |
| |
| |
| static void ip_handle_martian_source(struct net_device *dev, |
| struct in_device *in_dev, |
| struct sk_buff *skb, |
| __be32 daddr, |
| __be32 saddr) |
| { |
| RT_CACHE_STAT_INC(in_martian_src); |
| #ifdef CONFIG_IP_ROUTE_VERBOSE |
| if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { |
| /* |
| * RFC1812 recommendation, if source is martian, |
| * the only hint is MAC header. |
| */ |
| pr_warn("martian source %pI4 from %pI4, on dev %s\n", |
| &daddr, &saddr, dev->name); |
| if (dev->hard_header_len && skb_mac_header_was_set(skb)) { |
| print_hex_dump(KERN_WARNING, "ll header: ", |
| DUMP_PREFIX_OFFSET, 16, 1, |
| skb_mac_header(skb), |
| dev->hard_header_len, true); |
| } |
| } |
| #endif |
| } |
| |
| /* called in rcu_read_lock() section */ |
| static int __mkroute_input(struct sk_buff *skb, |
| const struct fib_result *res, |
| struct in_device *in_dev, |
| __be32 daddr, __be32 saddr, u32 tos) |
| { |
| struct rtable *rth; |
| int err; |
| struct in_device *out_dev; |
| unsigned int flags = 0; |
| bool do_cache; |
| u32 itag; |
| |
| /* get a working reference to the output device */ |
| out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); |
| if (out_dev == NULL) { |
| net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); |
| return -EINVAL; |
| } |
| |
| |
| err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), |
| in_dev->dev, in_dev, &itag); |
| if (err < 0) { |
| ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, |
| saddr); |
| |
| goto cleanup; |
| } |
| |
| if (out_dev == in_dev && err && |
| (IN_DEV_SHARED_MEDIA(out_dev) || |
| inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) |
| flags |= RTCF_DOREDIRECT; |
| |
| if (skb->protocol != htons(ETH_P_IP)) { |
| /* Not IP (i.e. ARP). Do not create route, if it is |
| * invalid for proxy arp. DNAT routes are always valid. |
| * |
| * Proxy arp feature have been extended to allow, ARP |
| * replies back to the same interface, to support |
| * Private VLAN switch technologies. See arp.c. |
| */ |
| if (out_dev == in_dev && |
| IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { |
| err = -EINVAL; |
| goto cleanup; |
| } |
| } |
| |
| do_cache = false; |
| if (res->fi) { |
| if (!itag) { |
| rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); |
| if (rt_cache_valid(rth)) { |
| skb_dst_set_noref(skb, &rth->dst); |
| goto out; |
| } |
| do_cache = true; |
| } |
| } |
| |
| rth = rt_dst_alloc(out_dev->dev, |
| IN_DEV_CONF_GET(in_dev, NOPOLICY), |
| IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); |
| if (!rth) { |
| err = -ENOBUFS; |
| goto cleanup; |
| } |
| |
| rth->rt_genid = rt_genid(dev_net(rth->dst.dev)); |
| rth->rt_flags = flags; |
| rth->rt_type = res->type; |
| rth->rt_is_input = 1; |
| rth->rt_iif = 0; |
| rth->rt_pmtu = 0; |
| rth->rt_gateway = 0; |
| INIT_LIST_HEAD(&rth->rt_uncached); |
| |
| rth->dst.input = ip_forward; |
| rth->dst.output = ip_output; |
| |
| rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag); |
| skb_dst_set(skb, &rth->dst); |
| out: |
| err = 0; |
| cleanup: |
| return err; |
| } |
| |
| static int ip_mkroute_input(struct sk_buff *skb, |
| struct fib_result *res, |
| const struct flowi4 *fl4, |
| struct in_device *in_dev, |
| __be32 daddr, __be32 saddr, u32 tos) |
| { |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (res->fi && res->fi->fib_nhs > 1) |
| fib_select_multipath(res); |
| #endif |
| |
| /* create a routing cache entry */ |
| return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); |
| } |
| |
| /* |
| * NOTE. We drop all the packets that has local source |
| * addresses, because every properly looped back packet |
| * must have correct destination already attached by output routine. |
| * |
| * Such approach solves two big problems: |
| * 1. Not simplex devices are handled properly. |
| * 2. IP spoofing attempts are filtered with 100% of guarantee. |
| * called with rcu_read_lock() |
| */ |
| |
| static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| u8 tos, struct net_device *dev) |
| { |
| struct fib_result res; |
| struct in_device *in_dev = __in_dev_get_rcu(dev); |
| struct flowi4 fl4; |
| unsigned int flags = 0; |
| u32 itag = 0; |
| struct rtable *rth; |
| int err = -EINVAL; |
| struct net *net = dev_net(dev); |
| bool do_cache; |
| |
| /* IP on this device is disabled. */ |
| |
| if (!in_dev) |
| goto out; |
| |
| /* Check for the most weird martians, which can be not detected |
| by fib_lookup. |
| */ |
| |
| if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) |
| goto martian_source; |
| |
| res.fi = NULL; |
| if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) |
| goto brd_input; |
| |
| /* Accept zero addresses only to limited broadcast; |
| * I even do not know to fix it or not. Waiting for complains :-) |
| */ |
| if (ipv4_is_zeronet(saddr)) |
| goto martian_source; |
| |
| if (ipv4_is_zeronet(daddr)) |
| goto martian_destination; |
| |
| if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) { |
| if (ipv4_is_loopback(daddr)) |
| goto martian_destination; |
| |
| if (ipv4_is_loopback(saddr)) |
| goto martian_source; |
| } |
| |
| /* |
| * Now we are ready to route packet. |
| */ |
| fl4.flowi4_oif = 0; |
| fl4.flowi4_iif = dev->ifindex; |
| fl4.flowi4_mark = skb->mark; |
| fl4.flowi4_tos = tos; |
| fl4.flowi4_scope = RT_SCOPE_UNIVERSE; |
| fl4.daddr = daddr; |
| fl4.saddr = saddr; |
| err = fib_lookup(net, &fl4, &res); |
| if (err != 0) |
| goto no_route; |
| |
| RT_CACHE_STAT_INC(in_slow_tot); |
| |
| if (res.type == RTN_BROADCAST) |
| goto brd_input; |
| |
| if (res.type == RTN_LOCAL) { |
| err = fib_validate_source(skb, saddr, daddr, tos, |
| net->loopback_dev->ifindex, |
| dev, in_dev, &itag); |
| if (err < 0) |
| goto martian_source_keep_err; |
| goto local_input; |
| } |
| |
| if (!IN_DEV_FORWARD(in_dev)) |
| goto no_route; |
| if (res.type != RTN_UNICAST) |
| goto martian_destination; |
| |
| err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); |
| out: return err; |
| |
| brd_input: |
| if (skb->protocol != htons(ETH_P_IP)) |
| goto e_inval; |
| |
| if (!ipv4_is_zeronet(saddr)) { |
| err = fib_validate_source(skb, saddr, 0, tos, 0, dev, |
| in_dev, &itag); |
| if (err < 0) |
| goto martian_source_keep_err; |
| } |
| flags |= RTCF_BROADCAST; |
| res.type = RTN_BROADCAST; |
| RT_CACHE_STAT_INC(in_brd); |
| |
| local_input: |
| do_cache = false; |
| if (res.fi) { |
| if (!itag) { |
| rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); |
| if (rt_cache_valid(rth)) { |
| skb_dst_set_noref(skb, &rth->dst); |
| err = 0; |
| goto out; |
| } |
| do_cache = true; |
| } |
| } |
| |
| rth = rt_dst_alloc(net->loopback_dev, |
| IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); |
| if (!rth) |
| goto e_nobufs; |
| |
| rth->dst.input= ip_local_deliver; |
| rth->dst.output= ip_rt_bug; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| rth->dst.tclassid = itag; |
| #endif |
| |
| rth->rt_genid = rt_genid(net); |
| rth->rt_flags = flags|RTCF_LOCAL; |
| rth->rt_type = res.type; |
| rth->rt_is_input = 1; |
| rth->rt_iif = 0; |
| rth->rt_pmtu = 0; |
| rth->rt_gateway = 0; |
| INIT_LIST_HEAD(&rth->rt_uncached); |
| if (res.type == RTN_UNREACHABLE) { |
| rth->dst.input= ip_error; |
| rth->dst.error= -err; |
| rth->rt_flags &= ~RTCF_LOCAL; |
| } |
| if (do_cache) |
| rt_cache_route(&FIB_RES_NH(res), rth); |
| skb_dst_set(skb, &rth->dst); |
| err = 0; |
| goto out; |
| |
| no_route: |
| RT_CACHE_STAT_INC(in_no_route); |
| res.type = RTN_UNREACHABLE; |
| if (err == -ESRCH) |
| err = -ENETUNREACH; |
| goto local_input; |
| |
| /* |
| * Do not cache martian addresses: they should be logged (RFC1812) |
| */ |
| martian_destination: |
| RT_CACHE_STAT_INC(in_martian_dst); |
| #ifdef CONFIG_IP_ROUTE_VERBOSE |
| if (IN_DEV_LOG_MARTIANS(in_dev)) |
| net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", |
| &daddr, &saddr, dev->name); |
| #endif |
| |
| e_inval: |
| err = -EINVAL; |
| goto out; |
| |
| e_nobufs: |
| err = -ENOBUFS; |
| goto out; |
| |
| martian_source: |
| err = -EINVAL; |
| martian_source_keep_err: |
| ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); |
| goto out; |
| } |
| |
| int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| u8 tos, struct net_device *dev) |
| { |
| int res; |
| |
| rcu_read_lock(); |
| |
| /* Multicast recognition logic is moved from route cache to here. |
| The problem was that too many Ethernet cards have broken/missing |
| hardware multicast filters :-( As result the host on multicasting |
| network acquires a lot of useless route cache entries, sort of |
| SDR messages from all the world. Now we try to get rid of them. |
| Really, provided software IP multicast filter is organized |
| reasonably (at least, hashed), it does not result in a slowdown |
| comparing with route cache reject entries. |
| Note, that multicast routers are not affected, because |
| route cache entry is created eventually. |
| */ |
| if (ipv4_is_multicast(daddr)) { |
| struct in_device *in_dev = __in_dev_get_rcu(dev); |
| |
| if (in_dev) { |
| int our = ip_check_mc_rcu(in_dev, daddr, saddr, |
| ip_hdr(skb)->protocol); |
| if (our |
| #ifdef CONFIG_IP_MROUTE |
| || |
| (!ipv4_is_local_multicast(daddr) && |
| IN_DEV_MFORWARD(in_dev)) |
| #endif |
| ) { |
| int res = ip_route_input_mc(skb, daddr, saddr, |
| tos, dev, our); |
| rcu_read_unlock(); |
| return res; |
| } |
| } |
| rcu_read_unlock(); |
| return -EINVAL; |
| } |
| res = ip_route_input_slow(skb, daddr, saddr, tos, dev); |
| rcu_read_unlock(); |
| return res; |
| } |
| EXPORT_SYMBOL(ip_route_input_noref); |
| |
| /* called with rcu_read_lock() */ |
| static struct rtable *__mkroute_output(const struct fib_result *res, |
| const struct flowi4 *fl4, int orig_oif, |
| struct net_device *dev_out, |
| unsigned int flags) |
| { |
| struct fib_info *fi = res->fi; |
| struct fib_nh_exception *fnhe; |
| struct in_device *in_dev; |
| u16 type = res->type; |
| struct rtable *rth; |
| |
| in_dev = __in_dev_get_rcu(dev_out); |
| if (!in_dev) |
| return ERR_PTR(-EINVAL); |
| |
| if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) |
| if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) |
| return ERR_PTR(-EINVAL); |
| |
| if (ipv4_is_lbcast(fl4->daddr)) |
| type = RTN_BROADCAST; |
| else if (ipv4_is_multicast(fl4->daddr)) |
| type = RTN_MULTICAST; |
| else if (ipv4_is_zeronet(fl4->daddr)) |
| return ERR_PTR(-EINVAL); |
| |
| if (dev_out->flags & IFF_LOOPBACK) |
| flags |= RTCF_LOCAL; |
| |
| if (type == RTN_BROADCAST) { |
| flags |= RTCF_BROADCAST | RTCF_LOCAL; |
| fi = NULL; |
| } else if (type == RTN_MULTICAST) { |
| flags |= RTCF_MULTICAST | RTCF_LOCAL; |
| if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, |
| fl4->flowi4_proto)) |
| flags &= ~RTCF_LOCAL; |
| /* If multicast route do not exist use |
| * default one, but do not gateway in this case. |
| * Yes, it is hack. |
| */ |
| if (fi && res->prefixlen < 4) |
| fi = NULL; |
| } |
| |
| fnhe = NULL; |
| if (fi) { |
| struct rtable __rcu **prth; |
| |
| fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr); |
| if (fnhe) |
| prth = &fnhe->fnhe_rth; |
| else |
| prth = __this_cpu_ptr(FIB_RES_NH(*res).nh_pcpu_rth_output); |
| rth = rcu_dereference(*prth); |
| if (rt_cache_valid(rth)) { |
| dst_hold(&rth->dst); |
| return rth; |
| } |
| } |
| rth = rt_dst_alloc(dev_out, |
| IN_DEV_CONF_GET(in_dev, NOPOLICY), |
| IN_DEV_CONF_GET(in_dev, NOXFRM), |
| fi); |
| if (!rth) |
| return ERR_PTR(-ENOBUFS); |
| |
| rth->dst.output = ip_output; |
| |
| rth->rt_genid = rt_genid(dev_net(dev_out)); |
| rth->rt_flags = flags; |
| rth->rt_type = type; |
| rth->rt_is_input = 0; |
| rth->rt_iif = orig_oif ? : 0; |
| rth->rt_pmtu = 0; |
| rth->rt_gateway = 0; |
| INIT_LIST_HEAD(&rth->rt_uncached); |
| |
| RT_CACHE_STAT_INC(out_slow_tot); |
| |
| if (flags & RTCF_LOCAL) |
| rth->dst.input = ip_local_deliver; |
| if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
| if (flags & RTCF_LOCAL && |
| !(dev_out->flags & IFF_LOOPBACK)) { |
| rth->dst.output = ip_mc_output; |
| RT_CACHE_STAT_INC(out_slow_mc); |
| } |
| #ifdef CONFIG_IP_MROUTE |
| if (type == RTN_MULTICAST) { |
| if (IN_DEV_MFORWARD(in_dev) && |
| !ipv4_is_local_multicast(fl4->daddr)) { |
| rth->dst.input = ip_mr_input; |
| rth->dst.output = ip_mc_output; |
| } |
| } |
| #endif |
| } |
| |
| rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); |
| |
| return rth; |
| } |
| |
| /* |
| * Major route resolver routine. |
| */ |
| |
| struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) |
| { |
| struct net_device *dev_out = NULL; |
| __u8 tos = RT_FL_TOS(fl4); |
| unsigned int flags = 0; |
| struct fib_result res; |
| struct rtable *rth; |
| int orig_oif; |
| |
| res.tclassid = 0; |
| res.fi = NULL; |
| res.table = NULL; |
| |
| orig_oif = fl4->flowi4_oif; |
| |
| fl4->flowi4_iif = net->loopback_dev->ifindex; |
| fl4->flowi4_tos = tos & IPTOS_RT_MASK; |
| fl4->flowi4_scope = ((tos & RTO_ONLINK) ? |
| RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); |
| |
| rcu_read_lock(); |
| if (fl4->saddr) { |
| rth = ERR_PTR(-EINVAL); |
| if (ipv4_is_multicast(fl4->saddr) || |
| ipv4_is_lbcast(fl4->saddr) || |
| ipv4_is_zeronet(fl4->saddr)) |
| goto out; |
| |
| /* I removed check for oif == dev_out->oif here. |
| It was wrong for two reasons: |
| 1. ip_dev_find(net, saddr) can return wrong iface, if saddr |
| is assigned to multiple interfaces. |
| 2. Moreover, we are allowed to send packets with saddr |
| of another iface. --ANK |
| */ |
| |
| if (fl4->flowi4_oif == 0 && |
| (ipv4_is_multicast(fl4->daddr) || |
| ipv4_is_lbcast(fl4->daddr))) { |
| /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ |
| dev_out = __ip_dev_find(net, fl4->saddr, false); |
| if (dev_out == NULL) |
| goto out; |
| |
| /* Special hack: user can direct multicasts |
| and limited broadcast via necessary interface |
| without fiddling with IP_MULTICAST_IF or IP_PKTINFO. |
| This hack is not just for fun, it allows |
| vic,vat and friends to work. |
| They bind socket to loopback, set ttl to zero |
| and expect that it will work. |
| From the viewpoint of routing cache they are broken, |
| because we are not allowed to build multicast path |
| with loopback source addr (look, routing cache |
| cannot know, that ttl is zero, so that packet |
| will not leave this host and route is valid). |
| Luckily, this hack is good workaround. |
| */ |
| |
| fl4->flowi4_oif = dev_out->ifindex; |
| goto make_route; |
| } |
| |
| if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { |
| /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ |
| if (!__ip_dev_find(net, fl4->saddr, false)) |
| goto out; |
| } |
| } |
| |
| |
| if (fl4->flowi4_oif) { |
| dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); |
| rth = ERR_PTR(-ENODEV); |
| if (dev_out == NULL) |
| goto out; |
| |
| /* RACE: Check return value of inet_select_addr instead. */ |
| if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { |
| rth = ERR_PTR(-ENETUNREACH); |
| goto out; |
| } |
| if (ipv4_is_local_multicast(fl4->daddr) || |
| ipv4_is_lbcast(fl4->daddr)) { |
| if (!fl4->saddr) |
| fl4->saddr = inet_select_addr(dev_out, 0, |
| RT_SCOPE_LINK); |
| goto make_route; |
| } |
| if (fl4->saddr) { |
| if (ipv4_is_multicast(fl4->daddr)) |
| fl4->saddr = inet_select_addr(dev_out, 0, |
| fl4->flowi4_scope); |
| else if (!fl4->daddr) |
| fl4->saddr = inet_select_addr(dev_out, 0, |
| RT_SCOPE_HOST); |
| } |
| } |
| |
| if (!fl4->daddr) { |
| fl4->daddr = fl4->saddr; |
| if (!fl4->daddr) |
| fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); |
| dev_out = net->loopback_dev; |
| fl4->flowi4_oif = net->loopback_dev->ifindex; |
| res.type = RTN_LOCAL; |
| flags |= RTCF_LOCAL; |
| goto make_route; |
| } |
| |
| if (fib_lookup(net, fl4, &res)) { |
| res.fi = NULL; |
| res.table = NULL; |
| if (fl4->flowi4_oif) { |
| /* Apparently, routing tables are wrong. Assume, |
| that the destination is on link. |
| |
| WHY? DW. |
| Because we are allowed to send to iface |
| even if it has NO routes and NO assigned |
| addresses. When oif is specified, routing |
| tables are looked up with only one purpose: |
| to catch if destination is gatewayed, rather than |
| direct. Moreover, if MSG_DONTROUTE is set, |
| we send packet, ignoring both routing tables |
| and ifaddr state. --ANK |
| |
| |
| We could make it even if oif is unknown, |
| likely IPv6, but we do not. |
| */ |
| |
| if (fl4->saddr == 0) |
| fl4->saddr = inet_select_addr(dev_out, 0, |
| RT_SCOPE_LINK); |
| res.type = RTN_UNICAST; |
| goto make_route; |
| } |
| rth = ERR_PTR(-ENETUNREACH); |
| goto out; |
| } |
| |
| if (res.type == RTN_LOCAL) { |
| if (!fl4->saddr) { |
| if (res.fi->fib_prefsrc) |
| fl4->saddr = res.fi->fib_prefsrc; |
| else |
| fl4->saddr = fl4->daddr; |
| } |
| dev_out = net->loopback_dev; |
| fl4->flowi4_oif = dev_out->ifindex; |
| flags |= RTCF_LOCAL; |
| goto make_route; |
| } |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) |
| fib_select_multipath(&res); |
| else |
| #endif |
| if (!res.prefixlen && |
| res.table->tb_num_default > 1 && |
| res.type == RTN_UNICAST && !fl4->flowi4_oif) |
| fib_select_default(&res); |
| |
| if (!fl4->saddr) |
| fl4->saddr = FIB_RES_PREFSRC(net, res); |
| |
| dev_out = FIB_RES_DEV(res); |
| fl4->flowi4_oif = dev_out->ifindex; |
| |
| |
| make_route: |
| rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); |
| |
| out: |
| rcu_read_unlock(); |
| return rth; |
| } |
| EXPORT_SYMBOL_GPL(__ip_route_output_key); |
| |
| static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) |
| { |
| return NULL; |
| } |
| |
| static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) |
| { |
| unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); |
| |
| return mtu ? : dst->dev->mtu; |
| } |
| |
| static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, |
| struct sk_buff *skb, u32 mtu) |
| { |
| } |
| |
| static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, |
| struct sk_buff *skb) |
| { |
| } |
| |
| static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, |
| unsigned long old) |
| { |
| return NULL; |
| } |
| |
| static struct dst_ops ipv4_dst_blackhole_ops = { |
| .family = AF_INET, |
| .protocol = cpu_to_be16(ETH_P_IP), |
| .check = ipv4_blackhole_dst_check, |
| .mtu = ipv4_blackhole_mtu, |
| .default_advmss = ipv4_default_advmss, |
| .update_pmtu = ipv4_rt_blackhole_update_pmtu, |
| .redirect = ipv4_rt_blackhole_redirect, |
| .cow_metrics = ipv4_rt_blackhole_cow_metrics, |
| .neigh_lookup = ipv4_neigh_lookup, |
| }; |
| |
| struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) |
| { |
| struct rtable *ort = (struct rtable *) dst_orig; |
| struct rtable *rt; |
| |
| rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); |
| if (rt) { |
| struct dst_entry *new = &rt->dst; |
| |
| new->__use = 1; |
| new->input = dst_discard; |
| new->output = dst_discard; |
| |
| new->dev = ort->dst.dev; |
| if (new->dev) |
| dev_hold(new->dev); |
| |
| rt->rt_is_input = ort->rt_is_input; |
| rt->rt_iif = ort->rt_iif; |
| rt->rt_pmtu = ort->rt_pmtu; |
| |
| rt->rt_genid = rt_genid(net); |
| rt->rt_flags = ort->rt_flags; |
| rt->rt_type = ort->rt_type; |
| rt->rt_gateway = ort->rt_gateway; |
| |
| INIT_LIST_HEAD(&rt->rt_uncached); |
| |
| dst_free(new); |
| } |
| |
| dst_release(dst_orig); |
| |
| return rt ? &rt->dst : ERR_PTR(-ENOMEM); |
| } |
| |
| struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, |
| struct sock *sk) |
| { |
| struct rtable *rt = __ip_route_output_key(net, flp4); |
| |
| if (IS_ERR(rt)) |
| return rt; |
| |
| if (flp4->flowi4_proto) |
| rt = (struct rtable *) xfrm_lookup(net, &rt->dst, |
| flowi4_to_flowi(flp4), |
| sk, 0); |
| |
| return rt; |
| } |
| EXPORT_SYMBOL_GPL(ip_route_output_flow); |
| |
| static int rt_fill_info(struct net *net, __be32 dst, __be32 src, |
| struct flowi4 *fl4, struct sk_buff *skb, u32 pid, |
| u32 seq, int event, int nowait, unsigned int flags) |
| { |
| struct rtable *rt = skb_rtable(skb); |
| struct rtmsg *r; |
| struct nlmsghdr *nlh; |
| unsigned long expires = 0; |
| u32 error; |
| u32 metrics[RTAX_MAX]; |
| |
| nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); |
| if (nlh == NULL) |
| return -EMSGSIZE; |
| |
| r = nlmsg_data(nlh); |
| r->rtm_family = AF_INET; |
| r->rtm_dst_len = 32; |
| r->rtm_src_len = 0; |
| r->rtm_tos = fl4->flowi4_tos; |
| r->rtm_table = RT_TABLE_MAIN; |
| if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) |
| goto nla_put_failure; |
| r->rtm_type = rt->rt_type; |
| r->rtm_scope = RT_SCOPE_UNIVERSE; |
| r->rtm_protocol = RTPROT_UNSPEC; |
| r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; |
| if (rt->rt_flags & RTCF_NOTIFY) |
| r->rtm_flags |= RTM_F_NOTIFY; |
| |
| if (nla_put_be32(skb, RTA_DST, dst)) |
| goto nla_put_failure; |
| if (src) { |
| r->rtm_src_len = 32; |
| if (nla_put_be32(skb, RTA_SRC, src)) |
| goto nla_put_failure; |
| } |
| if (rt->dst.dev && |
| nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) |
| goto nla_put_failure; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| if (rt->dst.tclassid && |
| nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) |
| goto nla_put_failure; |
| #endif |
| if (!rt_is_input_route(rt) && |
| fl4->saddr != src) { |
| if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr)) |
| goto nla_put_failure; |
| } |
| if (rt->rt_gateway && |
| nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway)) |
| goto nla_put_failure; |
| |
| memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); |
| if (rt->rt_pmtu) |
| metrics[RTAX_MTU - 1] = rt->rt_pmtu; |
| if (rtnetlink_put_metrics(skb, metrics) < 0) |
| goto nla_put_failure; |
| |
| if (fl4->flowi4_mark && |
| nla_put_be32(skb, RTA_MARK, fl4->flowi4_mark)) |
| goto nla_put_failure; |
| |
| error = rt->dst.error; |
| expires = rt->dst.expires; |
| if (expires) { |
| if (time_before(jiffies, expires)) |
| expires -= jiffies; |
| else |
| expires = 0; |
| } |
| |
| if (rt_is_input_route(rt)) { |
| if (nla_put_u32(skb, RTA_IIF, rt->rt_iif)) |
| goto nla_put_failure; |
| } |
| |
| if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) |
| goto nla_put_failure; |
| |
| return nlmsg_end(skb, nlh); |
| |
| nla_put_failure: |
| nlmsg_cancel(skb, nlh); |
| return -EMSGSIZE; |
| } |
| |
| static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg) |
| { |
| struct net *net = sock_net(in_skb->sk); |
| struct rtmsg *rtm; |
| struct nlattr *tb[RTA_MAX+1]; |
| struct rtable *rt = NULL; |
| struct flowi4 fl4; |
| __be32 dst = 0; |
| __be32 src = 0; |
| u32 iif; |
| int err; |
| int mark; |
| struct sk_buff *skb; |
| |
| err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); |
| if (err < 0) |
| goto errout; |
| |
| rtm = nlmsg_data(nlh); |
| |
| skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); |
| if (skb == NULL) { |
| err = -ENOBUFS; |
| goto errout; |
| } |
| |
| /* Reserve room for dummy headers, this skb can pass |
| through good chunk of routing engine. |
| */ |
| skb_reset_mac_header(skb); |
| skb_reset_network_header(skb); |
| |
| /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ |
| ip_hdr(skb)->protocol = IPPROTO_ICMP; |
| skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); |
| |
| src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; |
| dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; |
| iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; |
| mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; |
| |
| memset(&fl4, 0, sizeof(fl4)); |
| fl4.daddr = dst; |
| fl4.saddr = src; |
| fl4.flowi4_tos = rtm->rtm_tos; |
| fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; |
| fl4.flowi4_mark = mark; |
| |
| if (iif) { |
| struct net_device *dev; |
| |
| dev = __dev_get_by_index(net, iif); |
| if (dev == NULL) { |
| err = -ENODEV; |
| goto errout_free; |
| } |
| |
| skb->protocol = htons(ETH_P_IP); |
| skb->dev = dev; |
| skb->mark = mark; |
| local_bh_disable(); |
| err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); |
| local_bh_enable(); |
| |
| rt = skb_rtable(skb); |
| if (err == 0 && rt->dst.error) |
| err = -rt->dst.error; |
| } else { |
| rt = ip_route_output_key(net, &fl4); |
| |
| err = 0; |
| if (IS_ERR(rt)) |
| err = PTR_ERR(rt); |
| } |
| |
| if (err) |
| goto errout_free; |
| |
| skb_dst_set(skb, &rt->dst); |
| if (rtm->rtm_flags & RTM_F_NOTIFY) |
| rt->rt_flags |= RTCF_NOTIFY; |
| |
| err = rt_fill_info(net, dst, src, &fl4, skb, |
| NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, |
| RTM_NEWROUTE, 0, 0); |
| if (err <= 0) |
| goto errout_free; |
| |
| err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); |
| errout: |
| return err; |
| |
| errout_free: |
| kfree_skb(skb); |
| goto errout; |
| } |
| |
| int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) |
| { |
| return skb->len; |
| } |
| |
| void ip_rt_multicast_event(struct in_device *in_dev) |
| { |
| rt_cache_flush(dev_net(in_dev->dev), 0); |
| } |
| |
| #ifdef CONFIG_SYSCTL |
| static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, |
| void __user *buffer, |
| size_t *lenp, loff_t *ppos) |
| { |
| if (write) { |
| int flush_delay; |
| ctl_table ctl; |
| struct net *net; |
| |
| memcpy(&ctl, __ctl, sizeof(ctl)); |
| ctl.data = &flush_delay; |
| proc_dointvec(&ctl, write, buffer, lenp, ppos); |
| |
| net = (struct net *)__ctl->extra1; |
| rt_cache_flush(net, flush_delay); |
| return 0; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static ctl_table ipv4_route_table[] = { |
| { |
| .procname = "gc_thresh", |
| .data = &ipv4_dst_ops.gc_thresh, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| .procname = "max_size", |
| .data = &ip_rt_max_size, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| /* Deprecated. Use gc_min_interval_ms */ |
| |
| .procname = "gc_min_interval", |
| .data = &ip_rt_gc_min_interval, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_jiffies, |
| }, |
| { |
| .procname = "gc_min_interval_ms", |
| .data = &ip_rt_gc_min_interval, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_ms_jiffies, |
| }, |
| { |
| .procname = "gc_timeout", |
| .data = &ip_rt_gc_timeout, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_jiffies, |
| }, |
| { |
| .procname = "gc_interval", |
| .data = &ip_rt_gc_interval, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_jiffies, |
| }, |
| { |
| .procname = "redirect_load", |
| .data = &ip_rt_redirect_load, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| .procname = "redirect_number", |
| .data = &ip_rt_redirect_number, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| .procname = "redirect_silence", |
| .data = &ip_rt_redirect_silence, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| .procname = "error_cost", |
| .data = &ip_rt_error_cost, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| .procname = "error_burst", |
| .data = &ip_rt_error_burst, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| .procname = "gc_elasticity", |
| .data = &ip_rt_gc_elasticity, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| .procname = "mtu_expires", |
| .data = &ip_rt_mtu_expires, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_jiffies, |
| }, |
| { |
| .procname = "min_pmtu", |
| .data = &ip_rt_min_pmtu, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { |
| .procname = "min_adv_mss", |
| .data = &ip_rt_min_advmss, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { } |
| }; |
| |
| static struct ctl_table ipv4_route_flush_table[] = { |
| { |
| .procname = "flush", |
| .maxlen = sizeof(int), |
| .mode = 0200, |
| .proc_handler = ipv4_sysctl_rtcache_flush, |
| }, |
| { }, |
| }; |
| |
| static __net_init int sysctl_route_net_init(struct net *net) |
| { |
| struct ctl_table *tbl; |
| |
| tbl = ipv4_route_flush_table; |
| if (!net_eq(net, &init_net)) { |
| tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); |
| if (tbl == NULL) |
| goto err_dup; |
| } |
| tbl[0].extra1 = net; |
| |
| net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); |
| if (net->ipv4.route_hdr == NULL) |
| goto err_reg; |
| return 0; |
| |
| err_reg: |
| if (tbl != ipv4_route_flush_table) |
| kfree(tbl); |
| err_dup: |
| return -ENOMEM; |
| } |
| |
| static __net_exit void sysctl_route_net_exit(struct net *net) |
| { |
| struct ctl_table *tbl; |
| |
| tbl = net->ipv4.route_hdr->ctl_table_arg; |
| unregister_net_sysctl_table(net->ipv4.route_hdr); |
| BUG_ON(tbl == ipv4_route_flush_table); |
| kfree(tbl); |
| } |
| |
| static __net_initdata struct pernet_operations sysctl_route_ops = { |
| .init = sysctl_route_net_init, |
| .exit = sysctl_route_net_exit, |
| }; |
| #endif |
| |
| static __net_init int rt_genid_init(struct net *net) |
| { |
| get_random_bytes(&net->ipv4.rt_genid, |
| sizeof(net->ipv4.rt_genid)); |
| get_random_bytes(&net->ipv4.dev_addr_genid, |
| sizeof(net->ipv4.dev_addr_genid)); |
| return 0; |
| } |
| |
| static __net_initdata struct pernet_operations rt_genid_ops = { |
| .init = rt_genid_init, |
| }; |
| |
| static int __net_init ipv4_inetpeer_init(struct net *net) |
| { |
| struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); |
| |
| if (!bp) |
| return -ENOMEM; |
| inet_peer_base_init(bp); |
| net->ipv4.peers = bp; |
| return 0; |
| } |
| |
| static void __net_exit ipv4_inetpeer_exit(struct net *net) |
| { |
| struct inet_peer_base *bp = net->ipv4.peers; |
| |
| net->ipv4.peers = NULL; |
| inetpeer_invalidate_tree(bp); |
| kfree(bp); |
| } |
| |
| static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { |
| .init = ipv4_inetpeer_init, |
| .exit = ipv4_inetpeer_exit, |
| }; |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; |
| #endif /* CONFIG_IP_ROUTE_CLASSID */ |
| |
| int __init ip_rt_init(void) |
| { |
| int rc = 0; |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); |
| if (!ip_rt_acct) |
| panic("IP: failed to allocate ip_rt_acct\n"); |
| #endif |
| |
| ipv4_dst_ops.kmem_cachep = |
| kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, |
| SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
| |
| ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; |
| |
| if (dst_entries_init(&ipv4_dst_ops) < 0) |
| panic("IP: failed to allocate ipv4_dst_ops counter\n"); |
| |
| if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) |
| panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); |
| |
| ipv4_dst_ops.gc_thresh = ~0; |
| ip_rt_max_size = INT_MAX; |
| |
| devinet_init(); |
| ip_fib_init(); |
| |
| if (ip_rt_proc_init()) |
| pr_err("Unable to create route proc files\n"); |
| #ifdef CONFIG_XFRM |
| xfrm_init(); |
| xfrm4_init(ip_rt_max_size); |
| #endif |
| rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); |
| |
| #ifdef CONFIG_SYSCTL |
| register_pernet_subsys(&sysctl_route_ops); |
| #endif |
| register_pernet_subsys(&rt_genid_ops); |
| register_pernet_subsys(&ipv4_inetpeer_ops); |
| return rc; |
| } |
| |
| #ifdef CONFIG_SYSCTL |
| /* |
| * We really need to sanitize the damn ipv4 init order, then all |
| * this nonsense will go away. |
| */ |
| void __init ip_static_sysctl_init(void) |
| { |
| register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); |
| } |
| #endif |