| /* |
| * 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. |
| */ |
| |
| #include <linux/module.h> |
| #include <asm/uaccess.h> |
| #include <asm/system.h> |
| #include <linux/bitops.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/bootmem.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/workqueue.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/jhash.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> |
| #endif |
| |
| #define RT_FL_TOS(oldflp4) \ |
| ((u32)(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; |
| static int rt_chain_length_max __read_mostly = 20; |
| |
| /* |
| * 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_default_mtu(const struct dst_entry *dst); |
| static void ipv4_dst_destroy(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, u32 mtu); |
| static int rt_garbage_collect(struct dst_ops *ops); |
| |
| 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) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| struct inet_peer *peer; |
| u32 *p = NULL; |
| |
| if (!rt->peer) |
| rt_bind_peer(rt, 1); |
| |
| peer = rt->peer; |
| if (peer) { |
| u32 *old_p = __DST_METRICS_PTR(old); |
| unsigned long prev, new; |
| |
| p = peer->metrics; |
| if (inet_metrics_new(peer)) |
| memcpy(p, old_p, sizeof(u32) * RTAX_MAX); |
| |
| new = (unsigned long) p; |
| prev = cmpxchg(&dst->_metrics, old, new); |
| |
| if (prev != old) { |
| p = __DST_METRICS_PTR(prev); |
| if (prev & DST_METRICS_READ_ONLY) |
| p = NULL; |
| } else { |
| if (rt->fi) { |
| fib_info_put(rt->fi); |
| rt->fi = NULL; |
| } |
| } |
| } |
| return p; |
| } |
| |
| static struct dst_ops ipv4_dst_ops = { |
| .family = AF_INET, |
| .protocol = cpu_to_be16(ETH_P_IP), |
| .gc = rt_garbage_collect, |
| .check = ipv4_dst_check, |
| .default_advmss = ipv4_default_advmss, |
| .default_mtu = ipv4_default_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, |
| .local_out = __ip_local_out, |
| }; |
| |
| #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) |
| }; |
| |
| |
| /* |
| * Route cache. |
| */ |
| |
| /* The locking scheme is rather straight forward: |
| * |
| * 1) Read-Copy Update protects the buckets of the central route hash. |
| * 2) Only writers remove entries, and they hold the lock |
| * as they look at rtable reference counts. |
| * 3) Only readers acquire references to rtable entries, |
| * they do so with atomic increments and with the |
| * lock held. |
| */ |
| |
| struct rt_hash_bucket { |
| struct rtable __rcu *chain; |
| }; |
| |
| #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ |
| defined(CONFIG_PROVE_LOCKING) |
| /* |
| * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks |
| * The size of this table is a power of two and depends on the number of CPUS. |
| * (on lockdep we have a quite big spinlock_t, so keep the size down there) |
| */ |
| #ifdef CONFIG_LOCKDEP |
| # define RT_HASH_LOCK_SZ 256 |
| #else |
| # if NR_CPUS >= 32 |
| # define RT_HASH_LOCK_SZ 4096 |
| # elif NR_CPUS >= 16 |
| # define RT_HASH_LOCK_SZ 2048 |
| # elif NR_CPUS >= 8 |
| # define RT_HASH_LOCK_SZ 1024 |
| # elif NR_CPUS >= 4 |
| # define RT_HASH_LOCK_SZ 512 |
| # else |
| # define RT_HASH_LOCK_SZ 256 |
| # endif |
| #endif |
| |
| static spinlock_t *rt_hash_locks; |
| # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)] |
| |
| static __init void rt_hash_lock_init(void) |
| { |
| int i; |
| |
| rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, |
| GFP_KERNEL); |
| if (!rt_hash_locks) |
| panic("IP: failed to allocate rt_hash_locks\n"); |
| |
| for (i = 0; i < RT_HASH_LOCK_SZ; i++) |
| spin_lock_init(&rt_hash_locks[i]); |
| } |
| #else |
| # define rt_hash_lock_addr(slot) NULL |
| |
| static inline void rt_hash_lock_init(void) |
| { |
| } |
| #endif |
| |
| static struct rt_hash_bucket *rt_hash_table __read_mostly; |
| static unsigned rt_hash_mask __read_mostly; |
| static unsigned int rt_hash_log __read_mostly; |
| |
| 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 unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx, |
| int genid) |
| { |
| return jhash_3words((__force u32)daddr, (__force u32)saddr, |
| idx, genid) |
| & rt_hash_mask; |
| } |
| |
| static inline int rt_genid(struct net *net) |
| { |
| return atomic_read(&net->ipv4.rt_genid); |
| } |
| |
| #ifdef CONFIG_PROC_FS |
| struct rt_cache_iter_state { |
| struct seq_net_private p; |
| int bucket; |
| int genid; |
| }; |
| |
| static struct rtable *rt_cache_get_first(struct seq_file *seq) |
| { |
| struct rt_cache_iter_state *st = seq->private; |
| struct rtable *r = NULL; |
| |
| for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) { |
| if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain)) |
| continue; |
| rcu_read_lock_bh(); |
| r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); |
| while (r) { |
| if (dev_net(r->dst.dev) == seq_file_net(seq) && |
| r->rt_genid == st->genid) |
| return r; |
| r = rcu_dereference_bh(r->dst.rt_next); |
| } |
| rcu_read_unlock_bh(); |
| } |
| return r; |
| } |
| |
| static struct rtable *__rt_cache_get_next(struct seq_file *seq, |
| struct rtable *r) |
| { |
| struct rt_cache_iter_state *st = seq->private; |
| |
| r = rcu_dereference_bh(r->dst.rt_next); |
| while (!r) { |
| rcu_read_unlock_bh(); |
| do { |
| if (--st->bucket < 0) |
| return NULL; |
| } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain)); |
| rcu_read_lock_bh(); |
| r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); |
| } |
| return r; |
| } |
| |
| static struct rtable *rt_cache_get_next(struct seq_file *seq, |
| struct rtable *r) |
| { |
| struct rt_cache_iter_state *st = seq->private; |
| while ((r = __rt_cache_get_next(seq, r)) != NULL) { |
| if (dev_net(r->dst.dev) != seq_file_net(seq)) |
| continue; |
| if (r->rt_genid == st->genid) |
| break; |
| } |
| return r; |
| } |
| |
| static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos) |
| { |
| struct rtable *r = rt_cache_get_first(seq); |
| |
| if (r) |
| while (pos && (r = rt_cache_get_next(seq, r))) |
| --pos; |
| return pos ? NULL : r; |
| } |
| |
| static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct rt_cache_iter_state *st = seq->private; |
| if (*pos) |
| return rt_cache_get_idx(seq, *pos - 1); |
| st->genid = rt_genid(seq_file_net(seq)); |
| return SEQ_START_TOKEN; |
| } |
| |
| static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| struct rtable *r; |
| |
| if (v == SEQ_START_TOKEN) |
| r = rt_cache_get_first(seq); |
| else |
| r = rt_cache_get_next(seq, v); |
| ++*pos; |
| return r; |
| } |
| |
| static void rt_cache_seq_stop(struct seq_file *seq, void *v) |
| { |
| if (v && v != SEQ_START_TOKEN) |
| rcu_read_unlock_bh(); |
| } |
| |
| 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"); |
| else { |
| struct rtable *r = v; |
| int len; |
| |
| seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t" |
| "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n", |
| r->dst.dev ? r->dst.dev->name : "*", |
| (__force u32)r->rt_dst, |
| (__force u32)r->rt_gateway, |
| r->rt_flags, atomic_read(&r->dst.__refcnt), |
| r->dst.__use, 0, (__force u32)r->rt_src, |
| dst_metric_advmss(&r->dst) + 40, |
| dst_metric(&r->dst, RTAX_WINDOW), |
| (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) + |
| dst_metric(&r->dst, RTAX_RTTVAR)), |
| r->rt_tos, |
| r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1, |
| r->dst.hh ? (r->dst.hh->hh_output == |
| dev_queue_xmit) : 0, |
| r->rt_spec_dst, &len); |
| |
| seq_printf(seq, "%*s\n", 127 - len, ""); |
| } |
| 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_net(inode, file, &rt_cache_seq_ops, |
| sizeof(struct rt_cache_iter_state)); |
| } |
| |
| 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_net, |
| }; |
| |
| |
| 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 void rt_free(struct rtable *rt) |
| { |
| call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); |
| } |
| |
| static inline void rt_drop(struct rtable *rt) |
| { |
| ip_rt_put(rt); |
| call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); |
| } |
| |
| static inline int rt_fast_clean(struct rtable *rth) |
| { |
| /* Kill broadcast/multicast entries very aggresively, if they |
| collide in hash table with more useful entries */ |
| return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) && |
| rt_is_input_route(rth) && rth->dst.rt_next; |
| } |
| |
| static inline int rt_valuable(struct rtable *rth) |
| { |
| return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) || |
| (rth->peer && rth->peer->pmtu_expires); |
| } |
| |
| static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2) |
| { |
| unsigned long age; |
| int ret = 0; |
| |
| if (atomic_read(&rth->dst.__refcnt)) |
| goto out; |
| |
| age = jiffies - rth->dst.lastuse; |
| if ((age <= tmo1 && !rt_fast_clean(rth)) || |
| (age <= tmo2 && rt_valuable(rth))) |
| goto out; |
| ret = 1; |
| out: return ret; |
| } |
| |
| /* Bits of score are: |
| * 31: very valuable |
| * 30: not quite useless |
| * 29..0: usage counter |
| */ |
| static inline u32 rt_score(struct rtable *rt) |
| { |
| u32 score = jiffies - rt->dst.lastuse; |
| |
| score = ~score & ~(3<<30); |
| |
| if (rt_valuable(rt)) |
| score |= (1<<31); |
| |
| if (rt_is_output_route(rt) || |
| !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL))) |
| score |= (1<<30); |
| |
| return score; |
| } |
| |
| static inline bool rt_caching(const struct net *net) |
| { |
| return net->ipv4.current_rt_cache_rebuild_count <= |
| net->ipv4.sysctl_rt_cache_rebuild_count; |
| } |
| |
| static inline bool compare_hash_inputs(const struct rtable *rt1, |
| const struct rtable *rt2) |
| { |
| return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | |
| ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | |
| (rt1->rt_iif ^ rt2->rt_iif)) == 0); |
| } |
| |
| static inline int compare_keys(struct rtable *rt1, struct rtable *rt2) |
| { |
| return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | |
| ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | |
| (rt1->rt_mark ^ rt2->rt_mark) | |
| (rt1->rt_tos ^ rt2->rt_tos) | |
| (rt1->rt_oif ^ rt2->rt_oif) | |
| (rt1->rt_iif ^ rt2->rt_iif)) == 0; |
| } |
| |
| static inline int compare_netns(struct rtable *rt1, struct rtable *rt2) |
| { |
| return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev)); |
| } |
| |
| static inline int rt_is_expired(struct rtable *rth) |
| { |
| return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); |
| } |
| |
| /* |
| * Perform a full scan of hash table and free all entries. |
| * Can be called by a softirq or a process. |
| * In the later case, we want to be reschedule if necessary |
| */ |
| static void rt_do_flush(struct net *net, int process_context) |
| { |
| unsigned int i; |
| struct rtable *rth, *next; |
| |
| for (i = 0; i <= rt_hash_mask; i++) { |
| struct rtable __rcu **pprev; |
| struct rtable *list; |
| |
| if (process_context && need_resched()) |
| cond_resched(); |
| rth = rcu_dereference_raw(rt_hash_table[i].chain); |
| if (!rth) |
| continue; |
| |
| spin_lock_bh(rt_hash_lock_addr(i)); |
| |
| list = NULL; |
| pprev = &rt_hash_table[i].chain; |
| rth = rcu_dereference_protected(*pprev, |
| lockdep_is_held(rt_hash_lock_addr(i))); |
| |
| while (rth) { |
| next = rcu_dereference_protected(rth->dst.rt_next, |
| lockdep_is_held(rt_hash_lock_addr(i))); |
| |
| if (!net || |
| net_eq(dev_net(rth->dst.dev), net)) { |
| rcu_assign_pointer(*pprev, next); |
| rcu_assign_pointer(rth->dst.rt_next, list); |
| list = rth; |
| } else { |
| pprev = &rth->dst.rt_next; |
| } |
| rth = next; |
| } |
| |
| spin_unlock_bh(rt_hash_lock_addr(i)); |
| |
| for (; list; list = next) { |
| next = rcu_dereference_protected(list->dst.rt_next, 1); |
| rt_free(list); |
| } |
| } |
| } |
| |
| /* |
| * While freeing expired entries, we compute average chain length |
| * and standard deviation, using fixed-point arithmetic. |
| * This to have an estimation of rt_chain_length_max |
| * rt_chain_length_max = max(elasticity, AVG + 4*SD) |
| * We use 3 bits for frational part, and 29 (or 61) for magnitude. |
| */ |
| |
| #define FRACT_BITS 3 |
| #define ONE (1UL << FRACT_BITS) |
| |
| /* |
| * Given a hash chain and an item in this hash chain, |
| * find if a previous entry has the same hash_inputs |
| * (but differs on tos, mark or oif) |
| * Returns 0 if an alias is found. |
| * Returns ONE if rth has no alias before itself. |
| */ |
| static int has_noalias(const struct rtable *head, const struct rtable *rth) |
| { |
| const struct rtable *aux = head; |
| |
| while (aux != rth) { |
| if (compare_hash_inputs(aux, rth)) |
| return 0; |
| aux = rcu_dereference_protected(aux->dst.rt_next, 1); |
| } |
| return ONE; |
| } |
| |
| /* |
| * 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); |
| if (delay >= 0) |
| rt_do_flush(net, !in_softirq()); |
| } |
| |
| /* Flush previous cache invalidated entries from the cache */ |
| void rt_cache_flush_batch(struct net *net) |
| { |
| rt_do_flush(net, !in_softirq()); |
| } |
| |
| static void rt_emergency_hash_rebuild(struct net *net) |
| { |
| if (net_ratelimit()) |
| printk(KERN_WARNING "Route hash chain too long!\n"); |
| rt_cache_invalidate(net); |
| } |
| |
| /* |
| Short description of GC goals. |
| |
| We want to build algorithm, which will keep routing cache |
| at some equilibrium point, when number of aged off entries |
| is kept approximately equal to newly generated ones. |
| |
| Current expiration strength is variable "expire". |
| We try to adjust it dynamically, so that if networking |
| is idle expires is large enough to keep enough of warm entries, |
| and when load increases it reduces to limit cache size. |
| */ |
| |
| static int rt_garbage_collect(struct dst_ops *ops) |
| { |
| static unsigned long expire = RT_GC_TIMEOUT; |
| static unsigned long last_gc; |
| static int rover; |
| static int equilibrium; |
| struct rtable *rth; |
| struct rtable __rcu **rthp; |
| unsigned long now = jiffies; |
| int goal; |
| int entries = dst_entries_get_fast(&ipv4_dst_ops); |
| |
| /* |
| * Garbage collection is pretty expensive, |
| * do not make it too frequently. |
| */ |
| |
| RT_CACHE_STAT_INC(gc_total); |
| |
| if (now - last_gc < ip_rt_gc_min_interval && |
| entries < ip_rt_max_size) { |
| RT_CACHE_STAT_INC(gc_ignored); |
| goto out; |
| } |
| |
| entries = dst_entries_get_slow(&ipv4_dst_ops); |
| /* Calculate number of entries, which we want to expire now. */ |
| goal = entries - (ip_rt_gc_elasticity << rt_hash_log); |
| if (goal <= 0) { |
| if (equilibrium < ipv4_dst_ops.gc_thresh) |
| equilibrium = ipv4_dst_ops.gc_thresh; |
| goal = entries - equilibrium; |
| if (goal > 0) { |
| equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1); |
| goal = entries - equilibrium; |
| } |
| } else { |
| /* We are in dangerous area. Try to reduce cache really |
| * aggressively. |
| */ |
| goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1); |
| equilibrium = entries - goal; |
| } |
| |
| if (now - last_gc >= ip_rt_gc_min_interval) |
| last_gc = now; |
| |
| if (goal <= 0) { |
| equilibrium += goal; |
| goto work_done; |
| } |
| |
| do { |
| int i, k; |
| |
| for (i = rt_hash_mask, k = rover; i >= 0; i--) { |
| unsigned long tmo = expire; |
| |
| k = (k + 1) & rt_hash_mask; |
| rthp = &rt_hash_table[k].chain; |
| spin_lock_bh(rt_hash_lock_addr(k)); |
| while ((rth = rcu_dereference_protected(*rthp, |
| lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) { |
| if (!rt_is_expired(rth) && |
| !rt_may_expire(rth, tmo, expire)) { |
| tmo >>= 1; |
| rthp = &rth->dst.rt_next; |
| continue; |
| } |
| *rthp = rth->dst.rt_next; |
| rt_free(rth); |
| goal--; |
| } |
| spin_unlock_bh(rt_hash_lock_addr(k)); |
| if (goal <= 0) |
| break; |
| } |
| rover = k; |
| |
| if (goal <= 0) |
| goto work_done; |
| |
| /* Goal is not achieved. We stop process if: |
| |
| - if expire reduced to zero. Otherwise, expire is halfed. |
| - if table is not full. |
| - if we are called from interrupt. |
| - jiffies check is just fallback/debug loop breaker. |
| We will not spin here for long time in any case. |
| */ |
| |
| RT_CACHE_STAT_INC(gc_goal_miss); |
| |
| if (expire == 0) |
| break; |
| |
| expire >>= 1; |
| #if RT_CACHE_DEBUG >= 2 |
| printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire, |
| dst_entries_get_fast(&ipv4_dst_ops), goal, i); |
| #endif |
| |
| if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) |
| goto out; |
| } while (!in_softirq() && time_before_eq(jiffies, now)); |
| |
| if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) |
| goto out; |
| if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size) |
| goto out; |
| if (net_ratelimit()) |
| printk(KERN_WARNING "dst cache overflow\n"); |
| RT_CACHE_STAT_INC(gc_dst_overflow); |
| return 1; |
| |
| work_done: |
| expire += ip_rt_gc_min_interval; |
| if (expire > ip_rt_gc_timeout || |
| dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh || |
| dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh) |
| expire = ip_rt_gc_timeout; |
| #if RT_CACHE_DEBUG >= 2 |
| printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire, |
| dst_entries_get_fast(&ipv4_dst_ops), goal, rover); |
| #endif |
| out: return 0; |
| } |
| |
| /* |
| * Returns number of entries in a hash chain that have different hash_inputs |
| */ |
| static int slow_chain_length(const struct rtable *head) |
| { |
| int length = 0; |
| const struct rtable *rth = head; |
| |
| while (rth) { |
| length += has_noalias(head, rth); |
| rth = rcu_dereference_protected(rth->dst.rt_next, 1); |
| } |
| return length >> FRACT_BITS; |
| } |
| |
| static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt, |
| struct sk_buff *skb, int ifindex) |
| { |
| struct rtable *rth, *cand; |
| struct rtable __rcu **rthp, **candp; |
| unsigned long now; |
| u32 min_score; |
| int chain_length; |
| int attempts = !in_softirq(); |
| |
| restart: |
| chain_length = 0; |
| min_score = ~(u32)0; |
| cand = NULL; |
| candp = NULL; |
| now = jiffies; |
| |
| if (!rt_caching(dev_net(rt->dst.dev))) { |
| /* |
| * If we're not caching, just tell the caller we |
| * were successful and don't touch the route. The |
| * caller hold the sole reference to the cache entry, and |
| * it will be released when the caller is done with it. |
| * If we drop it here, the callers have no way to resolve routes |
| * when we're not caching. Instead, just point *rp at rt, so |
| * the caller gets a single use out of the route |
| * Note that we do rt_free on this new route entry, so that |
| * once its refcount hits zero, we are still able to reap it |
| * (Thanks Alexey) |
| * Note: To avoid expensive rcu stuff for this uncached dst, |
| * we set DST_NOCACHE so that dst_release() can free dst without |
| * waiting a grace period. |
| */ |
| |
| rt->dst.flags |= DST_NOCACHE; |
| if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) { |
| int err = arp_bind_neighbour(&rt->dst); |
| if (err) { |
| if (net_ratelimit()) |
| printk(KERN_WARNING |
| "Neighbour table failure & not caching routes.\n"); |
| ip_rt_put(rt); |
| return ERR_PTR(err); |
| } |
| } |
| |
| goto skip_hashing; |
| } |
| |
| rthp = &rt_hash_table[hash].chain; |
| |
| spin_lock_bh(rt_hash_lock_addr(hash)); |
| while ((rth = rcu_dereference_protected(*rthp, |
| lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { |
| if (rt_is_expired(rth)) { |
| *rthp = rth->dst.rt_next; |
| rt_free(rth); |
| continue; |
| } |
| if (compare_keys(rth, rt) && compare_netns(rth, rt)) { |
| /* Put it first */ |
| *rthp = rth->dst.rt_next; |
| /* |
| * Since lookup is lockfree, the deletion |
| * must be visible to another weakly ordered CPU before |
| * the insertion at the start of the hash chain. |
| */ |
| rcu_assign_pointer(rth->dst.rt_next, |
| rt_hash_table[hash].chain); |
| /* |
| * Since lookup is lockfree, the update writes |
| * must be ordered for consistency on SMP. |
| */ |
| rcu_assign_pointer(rt_hash_table[hash].chain, rth); |
| |
| dst_use(&rth->dst, now); |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| |
| rt_drop(rt); |
| if (skb) |
| skb_dst_set(skb, &rth->dst); |
| return rth; |
| } |
| |
| if (!atomic_read(&rth->dst.__refcnt)) { |
| u32 score = rt_score(rth); |
| |
| if (score <= min_score) { |
| cand = rth; |
| candp = rthp; |
| min_score = score; |
| } |
| } |
| |
| chain_length++; |
| |
| rthp = &rth->dst.rt_next; |
| } |
| |
| if (cand) { |
| /* ip_rt_gc_elasticity used to be average length of chain |
| * length, when exceeded gc becomes really aggressive. |
| * |
| * The second limit is less certain. At the moment it allows |
| * only 2 entries per bucket. We will see. |
| */ |
| if (chain_length > ip_rt_gc_elasticity) { |
| *candp = cand->dst.rt_next; |
| rt_free(cand); |
| } |
| } else { |
| if (chain_length > rt_chain_length_max && |
| slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) { |
| struct net *net = dev_net(rt->dst.dev); |
| int num = ++net->ipv4.current_rt_cache_rebuild_count; |
| if (!rt_caching(net)) { |
| printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n", |
| rt->dst.dev->name, num); |
| } |
| rt_emergency_hash_rebuild(net); |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| |
| hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, |
| ifindex, rt_genid(net)); |
| goto restart; |
| } |
| } |
| |
| /* Try to bind route to arp only if it is output |
| route or unicast forwarding path. |
| */ |
| if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) { |
| int err = arp_bind_neighbour(&rt->dst); |
| if (err) { |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| |
| if (err != -ENOBUFS) { |
| rt_drop(rt); |
| return ERR_PTR(err); |
| } |
| |
| /* Neighbour tables are full and nothing |
| can be released. Try to shrink route cache, |
| it is most likely it holds some neighbour records. |
| */ |
| if (attempts-- > 0) { |
| int saved_elasticity = ip_rt_gc_elasticity; |
| int saved_int = ip_rt_gc_min_interval; |
| ip_rt_gc_elasticity = 1; |
| ip_rt_gc_min_interval = 0; |
| rt_garbage_collect(&ipv4_dst_ops); |
| ip_rt_gc_min_interval = saved_int; |
| ip_rt_gc_elasticity = saved_elasticity; |
| goto restart; |
| } |
| |
| if (net_ratelimit()) |
| printk(KERN_WARNING "ipv4: Neighbour table overflow.\n"); |
| rt_drop(rt); |
| return ERR_PTR(-ENOBUFS); |
| } |
| } |
| |
| rt->dst.rt_next = rt_hash_table[hash].chain; |
| |
| #if RT_CACHE_DEBUG >= 2 |
| if (rt->dst.rt_next) { |
| struct rtable *trt; |
| printk(KERN_DEBUG "rt_cache @%02x: %pI4", |
| hash, &rt->rt_dst); |
| for (trt = rt->dst.rt_next; trt; trt = trt->dst.rt_next) |
| printk(" . %pI4", &trt->rt_dst); |
| printk("\n"); |
| } |
| #endif |
| /* |
| * Since lookup is lockfree, we must make sure |
| * previous writes to rt are committed to memory |
| * before making rt visible to other CPUS. |
| */ |
| rcu_assign_pointer(rt_hash_table[hash].chain, rt); |
| |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| |
| skip_hashing: |
| if (skb) |
| skb_dst_set(skb, &rt->dst); |
| return rt; |
| } |
| |
| static atomic_t __rt_peer_genid = ATOMIC_INIT(0); |
| |
| static u32 rt_peer_genid(void) |
| { |
| return atomic_read(&__rt_peer_genid); |
| } |
| |
| void rt_bind_peer(struct rtable *rt, int create) |
| { |
| struct inet_peer *peer; |
| |
| peer = inet_getpeer_v4(rt->rt_dst, create); |
| |
| if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL) |
| inet_putpeer(peer); |
| else |
| rt->rt_peer_genid = rt_peer_genid(); |
| } |
| |
| /* |
| * 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 rtable *rt = (struct rtable *) dst; |
| |
| if (rt) { |
| if (rt->peer == NULL) |
| rt_bind_peer(rt, 1); |
| |
| /* If peer is attached to destination, it is never detached, |
| so that we need not to grab a lock to dereference it. |
| */ |
| if (rt->peer) { |
| iph->id = htons(inet_getid(rt->peer, more)); |
| return; |
| } |
| } else |
| printk(KERN_DEBUG "rt_bind_peer(0) @%p\n", |
| __builtin_return_address(0)); |
| |
| ip_select_fb_ident(iph); |
| } |
| EXPORT_SYMBOL(__ip_select_ident); |
| |
| static void rt_del(unsigned hash, struct rtable *rt) |
| { |
| struct rtable __rcu **rthp; |
| struct rtable *aux; |
| |
| rthp = &rt_hash_table[hash].chain; |
| spin_lock_bh(rt_hash_lock_addr(hash)); |
| ip_rt_put(rt); |
| while ((aux = rcu_dereference_protected(*rthp, |
| lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { |
| if (aux == rt || rt_is_expired(aux)) { |
| *rthp = aux->dst.rt_next; |
| rt_free(aux); |
| continue; |
| } |
| rthp = &aux->dst.rt_next; |
| } |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| } |
| |
| /* called in rcu_read_lock() section */ |
| void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, |
| __be32 saddr, struct net_device *dev) |
| { |
| struct in_device *in_dev = __in_dev_get_rcu(dev); |
| struct inet_peer *peer; |
| struct net *net; |
| |
| 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; |
| } |
| |
| peer = inet_getpeer_v4(daddr, 1); |
| if (peer) { |
| peer->redirect_learned.a4 = new_gw; |
| |
| inet_putpeer(peer); |
| |
| atomic_inc(&__rt_peer_genid); |
| } |
| return; |
| |
| reject_redirect: |
| #ifdef CONFIG_IP_ROUTE_VERBOSE |
| if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) |
| printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n" |
| " Advised path = %pI4 -> %pI4\n", |
| &old_gw, dev->name, &new_gw, |
| &saddr, &daddr); |
| #endif |
| ; |
| } |
| |
| 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) { |
| unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, |
| rt->rt_oif, |
| rt_genid(dev_net(dst->dev))); |
| #if RT_CACHE_DEBUG >= 1 |
| printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n", |
| &rt->rt_dst, rt->rt_tos); |
| #endif |
| rt_del(hash, rt); |
| ret = NULL; |
| } else if (rt->peer && |
| rt->peer->pmtu_expires && |
| time_after_eq(jiffies, rt->peer->pmtu_expires)) { |
| unsigned long orig = rt->peer->pmtu_expires; |
| |
| if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig) |
| dst_metric_set(dst, RTAX_MTU, |
| rt->peer->pmtu_orig); |
| } |
| } |
| 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; |
| 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(); |
| |
| if (!rt->peer) |
| rt_bind_peer(rt, 1); |
| peer = rt->peer; |
| 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; |
| return; |
| } |
| |
| /* 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_ratelimit()) |
| printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n", |
| &rt->rt_src, rt->rt_iif, |
| &rt->rt_dst, &rt->rt_gateway); |
| #endif |
| } |
| } |
| |
| static int ip_error(struct sk_buff *skb) |
| { |
| struct rtable *rt = skb_rtable(skb); |
| struct inet_peer *peer; |
| unsigned long now; |
| bool send; |
| int code; |
| |
| 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(dev_net(rt->dst.dev), |
| IPSTATS_MIB_INNOROUTES); |
| break; |
| case EACCES: |
| code = ICMP_PKT_FILTERED; |
| break; |
| } |
| |
| if (!rt->peer) |
| rt_bind_peer(rt, 1); |
| peer = rt->peer; |
| |
| 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; |
| } |
| if (send) |
| icmp_send(skb, ICMP_DEST_UNREACH, code, 0); |
| |
| out: kfree_skb(skb); |
| return 0; |
| } |
| |
| /* |
| * The last two values are not from the RFC but |
| * are needed for AMPRnet AX.25 paths. |
| */ |
| |
| static const unsigned short mtu_plateau[] = |
| {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 }; |
| |
| static inline unsigned short guess_mtu(unsigned short old_mtu) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++) |
| if (old_mtu > mtu_plateau[i]) |
| return mtu_plateau[i]; |
| return 68; |
| } |
| |
| unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph, |
| unsigned short new_mtu, |
| struct net_device *dev) |
| { |
| unsigned short old_mtu = ntohs(iph->tot_len); |
| unsigned short est_mtu = 0; |
| struct inet_peer *peer; |
| |
| peer = inet_getpeer_v4(iph->daddr, 1); |
| if (peer) { |
| unsigned short mtu = new_mtu; |
| |
| if (new_mtu < 68 || new_mtu >= old_mtu) { |
| /* BSD 4.2 derived systems incorrectly adjust |
| * tot_len by the IP header length, and report |
| * a zero MTU in the ICMP message. |
| */ |
| if (mtu == 0 && |
| old_mtu >= 68 + (iph->ihl << 2)) |
| old_mtu -= iph->ihl << 2; |
| mtu = guess_mtu(old_mtu); |
| } |
| |
| if (mtu < ip_rt_min_pmtu) |
| mtu = ip_rt_min_pmtu; |
| if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { |
| unsigned long pmtu_expires; |
| |
| pmtu_expires = jiffies + ip_rt_mtu_expires; |
| if (!pmtu_expires) |
| pmtu_expires = 1UL; |
| |
| est_mtu = mtu; |
| peer->pmtu_learned = mtu; |
| peer->pmtu_expires = pmtu_expires; |
| } |
| |
| inet_putpeer(peer); |
| |
| atomic_inc(&__rt_peer_genid); |
| } |
| return est_mtu ? : new_mtu; |
| } |
| |
| static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer) |
| { |
| unsigned long expires = peer->pmtu_expires; |
| |
| if (time_before(jiffies, expires)) { |
| u32 orig_dst_mtu = dst_mtu(dst); |
| if (peer->pmtu_learned < orig_dst_mtu) { |
| if (!peer->pmtu_orig) |
| peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU); |
| dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned); |
| } |
| } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires) |
| dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig); |
| } |
| |
| static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| struct inet_peer *peer; |
| |
| dst_confirm(dst); |
| |
| if (!rt->peer) |
| rt_bind_peer(rt, 1); |
| peer = rt->peer; |
| if (peer) { |
| if (mtu < ip_rt_min_pmtu) |
| mtu = ip_rt_min_pmtu; |
| if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { |
| unsigned long pmtu_expires; |
| |
| pmtu_expires = jiffies + ip_rt_mtu_expires; |
| if (!pmtu_expires) |
| pmtu_expires = 1UL; |
| |
| peer->pmtu_learned = mtu; |
| peer->pmtu_expires = pmtu_expires; |
| |
| atomic_inc(&__rt_peer_genid); |
| rt->rt_peer_genid = rt_peer_genid(); |
| } |
| check_peer_pmtu(dst, peer); |
| } |
| } |
| |
| static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| __be32 orig_gw = rt->rt_gateway; |
| |
| dst_confirm(&rt->dst); |
| |
| neigh_release(rt->dst.neighbour); |
| rt->dst.neighbour = NULL; |
| |
| rt->rt_gateway = peer->redirect_learned.a4; |
| if (arp_bind_neighbour(&rt->dst) || |
| !(rt->dst.neighbour->nud_state & NUD_VALID)) { |
| if (rt->dst.neighbour) |
| neigh_event_send(rt->dst.neighbour, NULL); |
| rt->rt_gateway = orig_gw; |
| return -EAGAIN; |
| } else { |
| rt->rt_flags |= RTCF_REDIRECTED; |
| call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, |
| rt->dst.neighbour); |
| } |
| return 0; |
| } |
| |
| static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| |
| if (rt_is_expired(rt)) |
| return NULL; |
| if (rt->rt_peer_genid != rt_peer_genid()) { |
| struct inet_peer *peer; |
| |
| if (!rt->peer) |
| rt_bind_peer(rt, 0); |
| |
| peer = rt->peer; |
| if (peer && peer->pmtu_expires) |
| check_peer_pmtu(dst, peer); |
| |
| if (peer && peer->redirect_learned.a4 && |
| peer->redirect_learned.a4 != rt->rt_gateway) { |
| if (check_peer_redir(dst, peer)) |
| return NULL; |
| } |
| |
| rt->rt_peer_genid = rt_peer_genid(); |
| } |
| return dst; |
| } |
| |
| static void ipv4_dst_destroy(struct dst_entry *dst) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| struct inet_peer *peer = rt->peer; |
| |
| if (rt->fi) { |
| fib_info_put(rt->fi); |
| rt->fi = NULL; |
| } |
| if (peer) { |
| rt->peer = NULL; |
| inet_putpeer(peer); |
| } |
| } |
| |
| |
| 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 && |
| rt->peer && |
| rt->peer->pmtu_expires) { |
| unsigned long orig = rt->peer->pmtu_expires; |
| |
| if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig) |
| dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig); |
| } |
| } |
| |
| static int ip_rt_bug(struct sk_buff *skb) |
| { |
| printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n", |
| &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, |
| skb->dev ? skb->dev->name : "?"); |
| kfree_skb(skb); |
| 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 rtable *rt) |
| { |
| __be32 src; |
| struct fib_result res; |
| |
| if (rt_is_output_route(rt)) |
| src = rt->rt_src; |
| else { |
| struct flowi4 fl4 = { |
| .daddr = rt->rt_key_dst, |
| .saddr = rt->rt_key_src, |
| .flowi4_tos = rt->rt_tos, |
| .flowi4_oif = rt->rt_oif, |
| .flowi4_iif = rt->rt_iif, |
| .flowi4_mark = rt->rt_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->rt_gateway, |
| 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_default_mtu(const struct dst_entry *dst) |
| { |
| unsigned int mtu = dst->dev->mtu; |
| |
| if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { |
| const struct rtable *rt = (const struct rtable *) dst; |
| |
| if (rt->rt_gateway != rt->rt_dst && mtu > 576) |
| mtu = 576; |
| } |
| |
| if (mtu > IP_MAX_MTU) |
| mtu = IP_MAX_MTU; |
| |
| return mtu; |
| } |
| |
| static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4, |
| struct fib_info *fi) |
| { |
| struct inet_peer *peer; |
| int create = 0; |
| |
| /* If a peer entry exists for this destination, we must hook |
| * it up in order to get at cached metrics. |
| */ |
| if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS)) |
| create = 1; |
| |
| rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create); |
| if (peer) { |
| rt->rt_peer_genid = rt_peer_genid(); |
| if (inet_metrics_new(peer)) |
| memcpy(peer->metrics, fi->fib_metrics, |
| sizeof(u32) * RTAX_MAX); |
| dst_init_metrics(&rt->dst, peer->metrics, false); |
| |
| if (peer->pmtu_expires) |
| check_peer_pmtu(&rt->dst, peer); |
| if (peer->redirect_learned.a4 && |
| peer->redirect_learned.a4 != rt->rt_gateway) { |
| rt->rt_gateway = peer->redirect_learned.a4; |
| rt->rt_flags |= RTCF_REDIRECTED; |
| } |
| } else { |
| if (fi->fib_metrics != (u32 *) dst_default_metrics) { |
| rt->fi = fi; |
| atomic_inc(&fi->fib_clntref); |
| } |
| dst_init_metrics(&rt->dst, fi->fib_metrics, true); |
| } |
| } |
| |
| static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4, |
| const struct fib_result *res, |
| struct fib_info *fi, u16 type, u32 itag) |
| { |
| struct dst_entry *dst = &rt->dst; |
| |
| if (fi) { |
| if (FIB_RES_GW(*res) && |
| FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) |
| rt->rt_gateway = FIB_RES_GW(*res); |
| rt_init_metrics(rt, fl4, fi); |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| dst->tclassid = FIB_RES_NH(*res).nh_tclassid; |
| #endif |
| } |
| |
| if (dst_mtu(dst) > IP_MAX_MTU) |
| dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU); |
| if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40) |
| dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40); |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| #ifdef CONFIG_IP_MULTIPLE_TABLES |
| set_class_tag(rt, fib_rules_tclass(res)); |
| #endif |
| set_class_tag(rt, itag); |
| #endif |
| } |
| |
| static struct rtable *rt_dst_alloc(struct net_device *dev, |
| bool nopolicy, bool noxfrm) |
| { |
| return dst_alloc(&ipv4_dst_ops, dev, 1, -1, |
| DST_HOST | |
| (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) |
| { |
| unsigned int hash; |
| struct rtable *rth; |
| __be32 spec_dst; |
| 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) || |
| ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP)) |
| goto e_inval; |
| |
| if (ipv4_is_zeronet(saddr)) { |
| if (!ipv4_is_local_multicast(daddr)) |
| goto e_inval; |
| spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); |
| } else { |
| err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, |
| &itag); |
| if (err < 0) |
| goto e_err; |
| } |
| rth = rt_dst_alloc(init_net.loopback_dev, |
| IN_DEV_CONF_GET(in_dev, NOPOLICY), false); |
| if (!rth) |
| goto e_nobufs; |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| rth->dst.tclassid = itag; |
| #endif |
| rth->dst.output = ip_rt_bug; |
| |
| rth->rt_key_dst = daddr; |
| rth->rt_key_src = saddr; |
| rth->rt_genid = rt_genid(dev_net(dev)); |
| rth->rt_flags = RTCF_MULTICAST; |
| rth->rt_type = RTN_MULTICAST; |
| rth->rt_tos = tos; |
| rth->rt_dst = daddr; |
| rth->rt_src = saddr; |
| rth->rt_route_iif = dev->ifindex; |
| rth->rt_iif = dev->ifindex; |
| rth->rt_oif = 0; |
| rth->rt_mark = skb->mark; |
| rth->rt_gateway = daddr; |
| rth->rt_spec_dst= spec_dst; |
| rth->rt_peer_genid = 0; |
| rth->peer = NULL; |
| rth->fi = NULL; |
| 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); |
| |
| hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev))); |
| rth = rt_intern_hash(hash, rth, skb, dev->ifindex); |
| err = 0; |
| if (IS_ERR(rth)) |
| err = PTR_ERR(rth); |
| |
| 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. |
| */ |
| printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n", |
| &daddr, &saddr, dev->name); |
| if (dev->hard_header_len && skb_mac_header_was_set(skb)) { |
| int i; |
| const unsigned char *p = skb_mac_header(skb); |
| printk(KERN_WARNING "ll header: "); |
| for (i = 0; i < dev->hard_header_len; i++, p++) { |
| printk("%02x", *p); |
| if (i < (dev->hard_header_len - 1)) |
| printk(":"); |
| } |
| printk("\n"); |
| } |
| } |
| #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 **result) |
| { |
| struct rtable *rth; |
| int err; |
| struct in_device *out_dev; |
| unsigned int flags = 0; |
| __be32 spec_dst; |
| u32 itag; |
| |
| /* get a working reference to the output device */ |
| out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); |
| if (out_dev == NULL) { |
| if (net_ratelimit()) |
| printk(KERN_CRIT "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, &spec_dst, &itag); |
| if (err < 0) { |
| ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, |
| saddr); |
| |
| goto cleanup; |
| } |
| |
| if (err) |
| flags |= RTCF_DIRECTSRC; |
| |
| 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; |
| } |
| } |
| |
| rth = rt_dst_alloc(out_dev->dev, |
| IN_DEV_CONF_GET(in_dev, NOPOLICY), |
| IN_DEV_CONF_GET(out_dev, NOXFRM)); |
| if (!rth) { |
| err = -ENOBUFS; |
| goto cleanup; |
| } |
| |
| rth->rt_key_dst = daddr; |
| rth->rt_key_src = saddr; |
| rth->rt_genid = rt_genid(dev_net(rth->dst.dev)); |
| rth->rt_flags = flags; |
| rth->rt_type = res->type; |
| rth->rt_tos = tos; |
| rth->rt_dst = daddr; |
| rth->rt_src = saddr; |
| rth->rt_route_iif = in_dev->dev->ifindex; |
| rth->rt_iif = in_dev->dev->ifindex; |
| rth->rt_oif = 0; |
| rth->rt_mark = skb->mark; |
| rth->rt_gateway = daddr; |
| rth->rt_spec_dst= spec_dst; |
| rth->rt_peer_genid = 0; |
| rth->peer = NULL; |
| rth->fi = NULL; |
| |
| rth->dst.input = ip_forward; |
| rth->dst.output = ip_output; |
| |
| rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag); |
| |
| *result = rth; |
| 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) |
| { |
| struct rtable* rth = NULL; |
| int err; |
| unsigned hash; |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (res->fi && res->fi->fib_nhs > 1) |
| fib_select_multipath(res); |
| #endif |
| |
| /* create a routing cache entry */ |
| err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth); |
| if (err) |
| return err; |
| |
| /* put it into the cache */ |
| hash = rt_hash(daddr, saddr, fl4->flowi4_iif, |
| rt_genid(dev_net(rth->dst.dev))); |
| rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif); |
| if (IS_ERR(rth)) |
| return PTR_ERR(rth); |
| return 0; |
| } |
| |
| /* |
| * 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 flags = 0; |
| u32 itag = 0; |
| struct rtable * rth; |
| unsigned hash; |
| __be32 spec_dst; |
| int err = -EINVAL; |
| struct net * net = dev_net(dev); |
| |
| /* 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) || |
| ipv4_is_loopback(saddr)) |
| goto martian_source; |
| |
| 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) || ipv4_is_loopback(daddr)) |
| goto martian_destination; |
| |
| /* |
| * 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) { |
| if (!IN_DEV_FORWARD(in_dev)) |
| goto e_hostunreach; |
| 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, &spec_dst, &itag); |
| if (err < 0) |
| goto martian_source_keep_err; |
| if (err) |
| flags |= RTCF_DIRECTSRC; |
| spec_dst = daddr; |
| goto local_input; |
| } |
| |
| if (!IN_DEV_FORWARD(in_dev)) |
| goto e_hostunreach; |
| 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)) |
| spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); |
| else { |
| err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, |
| &itag); |
| if (err < 0) |
| goto martian_source_keep_err; |
| if (err) |
| flags |= RTCF_DIRECTSRC; |
| } |
| flags |= RTCF_BROADCAST; |
| res.type = RTN_BROADCAST; |
| RT_CACHE_STAT_INC(in_brd); |
| |
| local_input: |
| rth = rt_dst_alloc(net->loopback_dev, |
| IN_DEV_CONF_GET(in_dev, NOPOLICY), false); |
| 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_key_dst = daddr; |
| rth->rt_key_src = saddr; |
| rth->rt_genid = rt_genid(net); |
| rth->rt_flags = flags|RTCF_LOCAL; |
| rth->rt_type = res.type; |
| rth->rt_tos = tos; |
| rth->rt_dst = daddr; |
| rth->rt_src = saddr; |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| rth->dst.tclassid = itag; |
| #endif |
| rth->rt_route_iif = dev->ifindex; |
| rth->rt_iif = dev->ifindex; |
| rth->rt_oif = 0; |
| rth->rt_mark = skb->mark; |
| rth->rt_gateway = daddr; |
| rth->rt_spec_dst= spec_dst; |
| rth->rt_peer_genid = 0; |
| rth->peer = NULL; |
| rth->fi = NULL; |
| if (res.type == RTN_UNREACHABLE) { |
| rth->dst.input= ip_error; |
| rth->dst.error= -err; |
| rth->rt_flags &= ~RTCF_LOCAL; |
| } |
| hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net)); |
| rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif); |
| err = 0; |
| if (IS_ERR(rth)) |
| err = PTR_ERR(rth); |
| goto out; |
| |
| no_route: |
| RT_CACHE_STAT_INC(in_no_route); |
| spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); |
| 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_ratelimit()) |
| printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n", |
| &daddr, &saddr, dev->name); |
| #endif |
| |
| e_hostunreach: |
| err = -EHOSTUNREACH; |
| goto out; |
| |
| 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_common(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| u8 tos, struct net_device *dev, bool noref) |
| { |
| struct rtable * rth; |
| unsigned hash; |
| int iif = dev->ifindex; |
| struct net *net; |
| int res; |
| |
| net = dev_net(dev); |
| |
| rcu_read_lock(); |
| |
| if (!rt_caching(net)) |
| goto skip_cache; |
| |
| tos &= IPTOS_RT_MASK; |
| hash = rt_hash(daddr, saddr, iif, rt_genid(net)); |
| |
| for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; |
| rth = rcu_dereference(rth->dst.rt_next)) { |
| if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) | |
| ((__force u32)rth->rt_key_src ^ (__force u32)saddr) | |
| (rth->rt_iif ^ iif) | |
| rth->rt_oif | |
| (rth->rt_tos ^ tos)) == 0 && |
| rth->rt_mark == skb->mark && |
| net_eq(dev_net(rth->dst.dev), net) && |
| !rt_is_expired(rth)) { |
| if (noref) { |
| dst_use_noref(&rth->dst, jiffies); |
| skb_dst_set_noref(skb, &rth->dst); |
| } else { |
| dst_use(&rth->dst, jiffies); |
| skb_dst_set(skb, &rth->dst); |
| } |
| RT_CACHE_STAT_INC(in_hit); |
| rcu_read_unlock(); |
| return 0; |
| } |
| RT_CACHE_STAT_INC(in_hlist_search); |
| } |
| |
| skip_cache: |
| /* 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_common); |
| |
| /* called with rcu_read_lock() */ |
| static struct rtable *__mkroute_output(const struct fib_result *res, |
| const struct flowi4 *fl4, |
| __be32 orig_daddr, __be32 orig_saddr, |
| int orig_oif, struct net_device *dev_out, |
| unsigned int flags) |
| { |
| struct fib_info *fi = res->fi; |
| u32 tos = RT_FL_TOS(fl4); |
| struct in_device *in_dev; |
| u16 type = res->type; |
| struct rtable *rth; |
| |
| 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; |
| |
| in_dev = __in_dev_get_rcu(dev_out); |
| if (!in_dev) |
| return ERR_PTR(-EINVAL); |
| |
| 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; |
| } |
| |
| rth = rt_dst_alloc(dev_out, |
| IN_DEV_CONF_GET(in_dev, NOPOLICY), |
| IN_DEV_CONF_GET(in_dev, NOXFRM)); |
| if (!rth) |
| return ERR_PTR(-ENOBUFS); |
| |
| rth->dst.output = ip_output; |
| |
| rth->rt_key_dst = orig_daddr; |
| rth->rt_key_src = orig_saddr; |
| rth->rt_genid = rt_genid(dev_net(dev_out)); |
| rth->rt_flags = flags; |
| rth->rt_type = type; |
| rth->rt_tos = tos; |
| rth->rt_dst = fl4->daddr; |
| rth->rt_src = fl4->saddr; |
| rth->rt_route_iif = 0; |
| rth->rt_iif = orig_oif ? : dev_out->ifindex; |
| rth->rt_oif = orig_oif; |
| rth->rt_mark = fl4->flowi4_mark; |
| rth->rt_gateway = fl4->daddr; |
| rth->rt_spec_dst= fl4->saddr; |
| rth->rt_peer_genid = 0; |
| rth->peer = NULL; |
| rth->fi = NULL; |
| |
| RT_CACHE_STAT_INC(out_slow_tot); |
| |
| if (flags & RTCF_LOCAL) { |
| rth->dst.input = ip_local_deliver; |
| rth->rt_spec_dst = fl4->daddr; |
| } |
| if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
| rth->rt_spec_dst = fl4->saddr; |
| 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, res, fi, type, 0); |
| |
| return rth; |
| } |
| |
| /* |
| * Major route resolver routine. |
| * called with rcu_read_lock(); |
| */ |
| |
| static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4) |
| { |
| struct net_device *dev_out = NULL; |
| u32 tos = RT_FL_TOS(fl4); |
| unsigned int flags = 0; |
| struct fib_result res; |
| struct rtable *rth; |
| __be32 orig_daddr; |
| __be32 orig_saddr; |
| int orig_oif; |
| |
| res.fi = NULL; |
| #ifdef CONFIG_IP_MULTIPLE_TABLES |
| res.r = NULL; |
| #endif |
| |
| orig_daddr = fl4->daddr; |
| orig_saddr = fl4->saddr; |
| 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; |
| 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; |
| res.fi = NULL; |
| 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_daddr, orig_saddr, orig_oif, |
| dev_out, flags); |
| if (!IS_ERR(rth)) { |
| unsigned int hash; |
| |
| hash = rt_hash(orig_daddr, orig_saddr, orig_oif, |
| rt_genid(dev_net(dev_out))); |
| rth = rt_intern_hash(hash, rth, NULL, orig_oif); |
| } |
| |
| out: |
| rcu_read_unlock(); |
| return rth; |
| } |
| |
| struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4) |
| { |
| struct rtable *rth; |
| unsigned int hash; |
| |
| if (!rt_caching(net)) |
| goto slow_output; |
| |
| hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net)); |
| |
| rcu_read_lock_bh(); |
| for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth; |
| rth = rcu_dereference_bh(rth->dst.rt_next)) { |
| if (rth->rt_key_dst == flp4->daddr && |
| rth->rt_key_src == flp4->saddr && |
| rt_is_output_route(rth) && |
| rth->rt_oif == flp4->flowi4_oif && |
| rth->rt_mark == flp4->flowi4_mark && |
| !((rth->rt_tos ^ flp4->flowi4_tos) & |
| (IPTOS_RT_MASK | RTO_ONLINK)) && |
| net_eq(dev_net(rth->dst.dev), net) && |
| !rt_is_expired(rth)) { |
| dst_use(&rth->dst, jiffies); |
| RT_CACHE_STAT_INC(out_hit); |
| rcu_read_unlock_bh(); |
| return rth; |
| } |
| RT_CACHE_STAT_INC(out_hlist_search); |
| } |
| rcu_read_unlock_bh(); |
| |
| slow_output: |
| return ip_route_output_slow(net, flp4); |
| } |
| 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_default_mtu(const struct dst_entry *dst) |
| { |
| return 0; |
| } |
| |
| static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) |
| { |
| } |
| |
| 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), |
| .destroy = ipv4_dst_destroy, |
| .check = ipv4_blackhole_dst_check, |
| .default_mtu = ipv4_blackhole_default_mtu, |
| .default_advmss = ipv4_default_advmss, |
| .update_pmtu = ipv4_rt_blackhole_update_pmtu, |
| .cow_metrics = ipv4_rt_blackhole_cow_metrics, |
| }; |
| |
| struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) |
| { |
| struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0); |
| struct rtable *ort = (struct rtable *) dst_orig; |
| |
| if (rt) { |
| struct dst_entry *new = &rt->dst; |
| |
| new->__use = 1; |
| new->input = dst_discard; |
| new->output = dst_discard; |
| dst_copy_metrics(new, &ort->dst); |
| |
| new->dev = ort->dst.dev; |
| if (new->dev) |
| dev_hold(new->dev); |
| |
| rt->rt_key_dst = ort->rt_key_dst; |
| rt->rt_key_src = ort->rt_key_src; |
| rt->rt_tos = ort->rt_tos; |
| rt->rt_route_iif = ort->rt_route_iif; |
| rt->rt_iif = ort->rt_iif; |
| rt->rt_oif = ort->rt_oif; |
| rt->rt_mark = ort->rt_mark; |
| |
| rt->rt_genid = rt_genid(net); |
| rt->rt_flags = ort->rt_flags; |
| rt->rt_type = ort->rt_type; |
| rt->rt_dst = ort->rt_dst; |
| rt->rt_src = ort->rt_src; |
| rt->rt_gateway = ort->rt_gateway; |
| rt->rt_spec_dst = ort->rt_spec_dst; |
| rt->peer = ort->peer; |
| if (rt->peer) |
| atomic_inc(&rt->peer->refcnt); |
| rt->fi = ort->fi; |
| if (rt->fi) |
| atomic_inc(&rt->fi->fib_clntref); |
| |
| 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) { |
| if (!flp4->saddr) |
| flp4->saddr = rt->rt_src; |
| if (!flp4->daddr) |
| flp4->daddr = rt->rt_dst; |
| 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, |
| 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; |
| long expires; |
| u32 id = 0, ts = 0, tsage = 0, error; |
| |
| 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 = rt->rt_tos; |
| r->rtm_table = RT_TABLE_MAIN; |
| NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN); |
| 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; |
| |
| NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst); |
| |
| if (rt->rt_key_src) { |
| r->rtm_src_len = 32; |
| NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src); |
| } |
| if (rt->dst.dev) |
| NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex); |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| if (rt->dst.tclassid) |
| NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid); |
| #endif |
| if (rt_is_input_route(rt)) |
| NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst); |
| else if (rt->rt_src != rt->rt_key_src) |
| NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src); |
| |
| if (rt->rt_dst != rt->rt_gateway) |
| NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway); |
| |
| if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0) |
| goto nla_put_failure; |
| |
| if (rt->rt_mark) |
| NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark); |
| |
| error = rt->dst.error; |
| expires = (rt->peer && rt->peer->pmtu_expires) ? |
| rt->peer->pmtu_expires - jiffies : 0; |
| if (rt->peer) { |
| inet_peer_refcheck(rt->peer); |
| id = atomic_read(&rt->peer->ip_id_count) & 0xffff; |
| if (rt->peer->tcp_ts_stamp) { |
| ts = rt->peer->tcp_ts; |
| tsage = get_seconds() - rt->peer->tcp_ts_stamp; |
| } |
| } |
| |
| if (rt_is_input_route(rt)) { |
| #ifdef CONFIG_IP_MROUTE |
| __be32 dst = rt->rt_dst; |
| |
| if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && |
| IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { |
| int err = ipmr_get_route(net, skb, r, nowait); |
| if (err <= 0) { |
| if (!nowait) { |
| if (err == 0) |
| return 0; |
| goto nla_put_failure; |
| } else { |
| if (err == -EMSGSIZE) |
| goto nla_put_failure; |
| error = err; |
| } |
| } |
| } else |
| #endif |
| NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif); |
| } |
| |
| if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage, |
| 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; |
| __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; |
| |
| 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 { |
| struct flowi4 fl4 = { |
| .daddr = dst, |
| .saddr = src, |
| .flowi4_tos = rtm->rtm_tos, |
| .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0, |
| .flowi4_mark = mark, |
| }; |
| 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, 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) |
| { |
| struct rtable *rt; |
| int h, s_h; |
| int idx, s_idx; |
| struct net *net; |
| |
| net = sock_net(skb->sk); |
| |
| s_h = cb->args[0]; |
| if (s_h < 0) |
| s_h = 0; |
| s_idx = idx = cb->args[1]; |
| for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) { |
| if (!rt_hash_table[h].chain) |
| continue; |
| rcu_read_lock_bh(); |
| for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt; |
| rt = rcu_dereference_bh(rt->dst.rt_next), idx++) { |
| if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx) |
| continue; |
| if (rt_is_expired(rt)) |
| continue; |
| skb_dst_set_noref(skb, &rt->dst); |
| if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid, |
| cb->nlh->nlmsg_seq, RTM_NEWROUTE, |
| 1, NLM_F_MULTI) <= 0) { |
| skb_dst_drop(skb); |
| rcu_read_unlock_bh(); |
| goto done; |
| } |
| skb_dst_drop(skb); |
| } |
| rcu_read_unlock_bh(); |
| } |
| |
| done: |
| cb->args[0] = h; |
| cb->args[1] = idx; |
| 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 empty[1]; |
| |
| static struct ctl_table ipv4_skeleton[] = |
| { |
| { .procname = "route", |
| .mode = 0555, .child = ipv4_route_table}, |
| { .procname = "neigh", |
| .mode = 0555, .child = empty}, |
| { } |
| }; |
| |
| static __net_initdata struct ctl_path ipv4_path[] = { |
| { .procname = "net", }, |
| { .procname = "ipv4", }, |
| { }, |
| }; |
| |
| static struct ctl_table ipv4_route_flush_table[] = { |
| { |
| .procname = "flush", |
| .maxlen = sizeof(int), |
| .mode = 0200, |
| .proc_handler = ipv4_sysctl_rtcache_flush, |
| }, |
| { }, |
| }; |
| |
| static __net_initdata struct ctl_path ipv4_route_path[] = { |
| { .procname = "net", }, |
| { .procname = "ipv4", }, |
| { .procname = "route", }, |
| { }, |
| }; |
| |
| 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_table(net, ipv4_route_path, 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, |
| }; |
| |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; |
| #endif /* CONFIG_IP_ROUTE_CLASSID */ |
| |
| static __initdata unsigned long rhash_entries; |
| static int __init set_rhash_entries(char *str) |
| { |
| if (!str) |
| return 0; |
| rhash_entries = simple_strtoul(str, &str, 0); |
| return 1; |
| } |
| __setup("rhash_entries=", set_rhash_entries); |
| |
| 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"); |
| |
| rt_hash_table = (struct rt_hash_bucket *) |
| alloc_large_system_hash("IP route cache", |
| sizeof(struct rt_hash_bucket), |
| rhash_entries, |
| (totalram_pages >= 128 * 1024) ? |
| 15 : 17, |
| 0, |
| &rt_hash_log, |
| &rt_hash_mask, |
| rhash_entries ? 0 : 512 * 1024); |
| memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket)); |
| rt_hash_lock_init(); |
| |
| ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1); |
| ip_rt_max_size = (rt_hash_mask + 1) * 16; |
| |
| devinet_init(); |
| ip_fib_init(); |
| |
| if (ip_rt_proc_init()) |
| printk(KERN_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); |
| |
| #ifdef CONFIG_SYSCTL |
| register_pernet_subsys(&sysctl_route_ops); |
| #endif |
| register_pernet_subsys(&rt_genid_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_sysctl_paths(ipv4_path, ipv4_skeleton); |
| } |
| #endif |