| /* |
| * 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. |
| * |
| * Version: $Id: route.c,v 1.103 2002/01/12 07:44:09 davem Exp $ |
| * |
| * 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 <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(oldflp) \ |
| ((u32)(oldflp->fl4_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 ip_rt_secret_interval __read_mostly = 10 * 60 * HZ; |
| |
| static void rt_worker_func(struct work_struct *work); |
| static DECLARE_DELAYED_WORK(expires_work, rt_worker_func); |
| static struct timer_list rt_secret_timer; |
| |
| /* |
| * Interface to generic destination cache. |
| */ |
| |
| static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); |
| 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 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 struct dst_ops ipv4_dst_ops = { |
| .family = AF_INET, |
| .protocol = __constant_htons(ETH_P_IP), |
| .gc = rt_garbage_collect, |
| .check = ipv4_dst_check, |
| .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, |
| .entry_size = sizeof(struct rtable), |
| .entries = ATOMIC_INIT(0), |
| }; |
| |
| #define ECN_OR_COST(class) TC_PRIO_##class |
| |
| const __u8 ip_tos2prio[16] = { |
| TC_PRIO_BESTEFFORT, |
| ECN_OR_COST(FILLER), |
| 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 *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 atomic_t rt_genid __read_mostly; |
| |
| static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); |
| #define RT_CACHE_STAT_INC(field) \ |
| (__raw_get_cpu_var(rt_cache_stat).field++) |
| |
| static unsigned int rt_hash_code(u32 daddr, u32 saddr) |
| { |
| return jhash_2words(daddr, saddr, atomic_read(&rt_genid)) |
| & rt_hash_mask; |
| } |
| |
| #define rt_hash(daddr, saddr, idx) \ |
| rt_hash_code((__force u32)(__be32)(daddr),\ |
| (__force u32)(__be32)(saddr) ^ ((idx) << 5)) |
| |
| #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 rt_cache_iter_state *st) |
| { |
| struct rtable *r = NULL; |
| |
| for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) { |
| rcu_read_lock_bh(); |
| r = rcu_dereference(rt_hash_table[st->bucket].chain); |
| while (r) { |
| if (dev_net(r->u.dst.dev) == st->p.net && |
| r->rt_genid == st->genid) |
| return r; |
| r = rcu_dereference(r->u.dst.rt_next); |
| } |
| rcu_read_unlock_bh(); |
| } |
| return r; |
| } |
| |
| static struct rtable *__rt_cache_get_next(struct rt_cache_iter_state *st, |
| struct rtable *r) |
| { |
| r = r->u.dst.rt_next; |
| while (!r) { |
| rcu_read_unlock_bh(); |
| if (--st->bucket < 0) |
| break; |
| rcu_read_lock_bh(); |
| r = rt_hash_table[st->bucket].chain; |
| } |
| return rcu_dereference(r); |
| } |
| |
| static struct rtable *rt_cache_get_next(struct rt_cache_iter_state *st, |
| struct rtable *r) |
| { |
| while ((r = __rt_cache_get_next(st, r)) != NULL) { |
| if (dev_net(r->u.dst.dev) != st->p.net) |
| continue; |
| if (r->rt_genid == st->genid) |
| break; |
| } |
| return r; |
| } |
| |
| static struct rtable *rt_cache_get_idx(struct rt_cache_iter_state *st, loff_t pos) |
| { |
| struct rtable *r = rt_cache_get_first(st); |
| |
| if (r) |
| while (pos && (r = rt_cache_get_next(st, 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(st, *pos - 1); |
| st->genid = atomic_read(&rt_genid); |
| return SEQ_START_TOKEN; |
| } |
| |
| static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| struct rtable *r; |
| struct rt_cache_iter_state *st = seq->private; |
| |
| if (v == SEQ_START_TOKEN) |
| r = rt_cache_get_first(st); |
| else |
| r = rt_cache_get_next(st, 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; |
| char temp[256]; |
| |
| sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t" |
| "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X", |
| r->u.dst.dev ? r->u.dst.dev->name : "*", |
| (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway, |
| r->rt_flags, atomic_read(&r->u.dst.__refcnt), |
| r->u.dst.__use, 0, (unsigned long)r->rt_src, |
| (dst_metric(&r->u.dst, RTAX_ADVMSS) ? |
| (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0), |
| dst_metric(&r->u.dst, RTAX_WINDOW), |
| (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) + |
| dst_metric(&r->u.dst, RTAX_RTTVAR)), |
| r->fl.fl4_tos, |
| r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1, |
| r->u.dst.hh ? (r->u.dst.hh->hh_output == |
| dev_queue_xmit) : 0, |
| r->rt_spec_dst); |
| seq_printf(seq, "%-127s\n", temp); |
| } |
| 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_CPUS; ++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_CPUS; ++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", |
| atomic_read(&ipv4_dst_ops.entries), |
| 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_NET_CLS_ROUTE |
| static int ip_rt_acct_read(char *buffer, char **start, off_t offset, |
| int length, int *eof, void *data) |
| { |
| unsigned int i; |
| |
| if ((offset & 3) || (length & 3)) |
| return -EIO; |
| |
| if (offset >= sizeof(struct ip_rt_acct) * 256) { |
| *eof = 1; |
| return 0; |
| } |
| |
| if (offset + length >= sizeof(struct ip_rt_acct) * 256) { |
| length = sizeof(struct ip_rt_acct) * 256 - offset; |
| *eof = 1; |
| } |
| |
| offset /= sizeof(u32); |
| |
| if (length > 0) { |
| u32 *dst = (u32 *) buffer; |
| |
| *start = buffer; |
| memset(dst, 0, length); |
| |
| for_each_possible_cpu(i) { |
| unsigned int j; |
| u32 *src; |
| |
| src = ((u32 *) per_cpu_ptr(ip_rt_acct, i)) + offset; |
| for (j = 0; j < length/4; j++) |
| dst[j] += src[j]; |
| } |
| } |
| return length; |
| } |
| #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_NET_CLS_ROUTE |
| pde = create_proc_read_entry("rt_acct", 0, net->proc_net, |
| ip_rt_acct_read, NULL); |
| if (!pde) |
| goto err3; |
| #endif |
| return 0; |
| |
| #ifdef CONFIG_NET_CLS_ROUTE |
| 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); |
| remove_proc_entry("rt_acct", net->proc_net); |
| } |
| |
| 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->u.dst.rcu_head, dst_rcu_free); |
| } |
| |
| static __inline__ void rt_drop(struct rtable *rt) |
| { |
| ip_rt_put(rt); |
| call_rcu_bh(&rt->u.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)) && |
| rth->fl.iif && rth->u.dst.rt_next; |
| } |
| |
| static __inline__ int rt_valuable(struct rtable *rth) |
| { |
| return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) || |
| rth->u.dst.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->u.dst.__refcnt)) |
| goto out; |
| |
| ret = 1; |
| if (rth->u.dst.expires && |
| time_after_eq(jiffies, rth->u.dst.expires)) |
| goto out; |
| |
| age = jiffies - rth->u.dst.lastuse; |
| ret = 0; |
| 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->u.dst.lastuse; |
| |
| score = ~score & ~(3<<30); |
| |
| if (rt_valuable(rt)) |
| score |= (1<<31); |
| |
| if (!rt->fl.iif || |
| !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL))) |
| score |= (1<<30); |
| |
| return score; |
| } |
| |
| static inline int compare_keys(struct flowi *fl1, struct flowi *fl2) |
| { |
| return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) | |
| (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) | |
| (fl1->mark ^ fl2->mark) | |
| (*(u16 *)&fl1->nl_u.ip4_u.tos ^ |
| *(u16 *)&fl2->nl_u.ip4_u.tos) | |
| (fl1->oif ^ fl2->oif) | |
| (fl1->iif ^ fl2->iif)) == 0; |
| } |
| |
| static inline int compare_netns(struct rtable *rt1, struct rtable *rt2) |
| { |
| return dev_net(rt1->u.dst.dev) == dev_net(rt2->u.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(int process_context) |
| { |
| unsigned int i; |
| struct rtable *rth, *next; |
| |
| for (i = 0; i <= rt_hash_mask; i++) { |
| if (process_context && need_resched()) |
| cond_resched(); |
| rth = rt_hash_table[i].chain; |
| if (!rth) |
| continue; |
| |
| spin_lock_bh(rt_hash_lock_addr(i)); |
| rth = rt_hash_table[i].chain; |
| rt_hash_table[i].chain = NULL; |
| spin_unlock_bh(rt_hash_lock_addr(i)); |
| |
| for (; rth; rth = next) { |
| next = rth->u.dst.rt_next; |
| rt_free(rth); |
| } |
| } |
| } |
| |
| static void rt_check_expire(void) |
| { |
| static unsigned int rover; |
| unsigned int i = rover, goal; |
| struct rtable *rth, **rthp; |
| u64 mult; |
| |
| mult = ((u64)ip_rt_gc_interval) << rt_hash_log; |
| if (ip_rt_gc_timeout > 1) |
| do_div(mult, ip_rt_gc_timeout); |
| goal = (unsigned int)mult; |
| if (goal > rt_hash_mask) |
| goal = rt_hash_mask + 1; |
| for (; goal > 0; goal--) { |
| unsigned long tmo = ip_rt_gc_timeout; |
| |
| i = (i + 1) & rt_hash_mask; |
| rthp = &rt_hash_table[i].chain; |
| |
| if (need_resched()) |
| cond_resched(); |
| |
| if (*rthp == NULL) |
| continue; |
| spin_lock_bh(rt_hash_lock_addr(i)); |
| while ((rth = *rthp) != NULL) { |
| if (rth->rt_genid != atomic_read(&rt_genid)) { |
| *rthp = rth->u.dst.rt_next; |
| rt_free(rth); |
| continue; |
| } |
| if (rth->u.dst.expires) { |
| /* Entry is expired even if it is in use */ |
| if (time_before_eq(jiffies, rth->u.dst.expires)) { |
| tmo >>= 1; |
| rthp = &rth->u.dst.rt_next; |
| continue; |
| } |
| } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) { |
| tmo >>= 1; |
| rthp = &rth->u.dst.rt_next; |
| continue; |
| } |
| |
| /* Cleanup aged off entries. */ |
| *rthp = rth->u.dst.rt_next; |
| rt_free(rth); |
| } |
| spin_unlock_bh(rt_hash_lock_addr(i)); |
| } |
| rover = i; |
| } |
| |
| /* |
| * rt_worker_func() is run in process context. |
| * we call rt_check_expire() to scan part of the hash table |
| */ |
| static void rt_worker_func(struct work_struct *work) |
| { |
| rt_check_expire(); |
| schedule_delayed_work(&expires_work, ip_rt_gc_interval); |
| } |
| |
| /* |
| * Pertubation 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(void) |
| { |
| unsigned char shuffle; |
| |
| get_random_bytes(&shuffle, sizeof(shuffle)); |
| atomic_add(shuffle + 1U, &rt_genid); |
| } |
| |
| /* |
| * delay < 0 : invalidate cache (fast : entries will be deleted later) |
| * delay >= 0 : invalidate & flush cache (can be long) |
| */ |
| void rt_cache_flush(int delay) |
| { |
| rt_cache_invalidate(); |
| if (delay >= 0) |
| rt_do_flush(!in_softirq()); |
| } |
| |
| /* |
| * We change rt_genid and let gc do the cleanup |
| */ |
| static void rt_secret_rebuild(unsigned long dummy) |
| { |
| rt_cache_invalidate(); |
| mod_timer(&rt_secret_timer, jiffies + ip_rt_secret_interval); |
| } |
| |
| /* |
| 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, **rthp; |
| unsigned long now = jiffies; |
| int goal; |
| |
| /* |
| * 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 && |
| atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) { |
| RT_CACHE_STAT_INC(gc_ignored); |
| goto out; |
| } |
| |
| /* Calculate number of entries, which we want to expire now. */ |
| goal = atomic_read(&ipv4_dst_ops.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 = atomic_read(&ipv4_dst_ops.entries) - equilibrium; |
| if (goal > 0) { |
| equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1); |
| goal = atomic_read(&ipv4_dst_ops.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 = atomic_read(&ipv4_dst_ops.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 = *rthp) != NULL) { |
| if (rth->rt_genid == atomic_read(&rt_genid) && |
| !rt_may_expire(rth, tmo, expire)) { |
| tmo >>= 1; |
| rthp = &rth->u.dst.rt_next; |
| continue; |
| } |
| *rthp = rth->u.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, |
| atomic_read(&ipv4_dst_ops.entries), goal, i); |
| #endif |
| |
| if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) |
| goto out; |
| } while (!in_softirq() && time_before_eq(jiffies, now)); |
| |
| if (atomic_read(&ipv4_dst_ops.entries) < 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 || |
| atomic_read(&ipv4_dst_ops.entries) < 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, |
| atomic_read(&ipv4_dst_ops.entries), goal, rover); |
| #endif |
| out: return 0; |
| } |
| |
| static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp) |
| { |
| struct rtable *rth, **rthp; |
| unsigned long now; |
| struct rtable *cand, **candp; |
| u32 min_score; |
| int chain_length; |
| int attempts = !in_softirq(); |
| |
| restart: |
| chain_length = 0; |
| min_score = ~(u32)0; |
| cand = NULL; |
| candp = NULL; |
| now = jiffies; |
| |
| rthp = &rt_hash_table[hash].chain; |
| |
| spin_lock_bh(rt_hash_lock_addr(hash)); |
| while ((rth = *rthp) != NULL) { |
| if (rth->rt_genid != atomic_read(&rt_genid)) { |
| *rthp = rth->u.dst.rt_next; |
| rt_free(rth); |
| continue; |
| } |
| if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) { |
| /* Put it first */ |
| *rthp = rth->u.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->u.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->u.dst, now); |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| |
| rt_drop(rt); |
| *rp = rth; |
| return 0; |
| } |
| |
| if (!atomic_read(&rth->u.dst.__refcnt)) { |
| u32 score = rt_score(rth); |
| |
| if (score <= min_score) { |
| cand = rth; |
| candp = rthp; |
| min_score = score; |
| } |
| } |
| |
| chain_length++; |
| |
| rthp = &rth->u.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->u.dst.rt_next; |
| rt_free(cand); |
| } |
| } |
| |
| /* Try to bind route to arp only if it is output |
| route or unicast forwarding path. |
| */ |
| if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) { |
| int err = arp_bind_neighbour(&rt->u.dst); |
| if (err) { |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| |
| if (err != -ENOBUFS) { |
| rt_drop(rt); |
| return 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 "Neighbour table overflow.\n"); |
| rt_drop(rt); |
| return -ENOBUFS; |
| } |
| } |
| |
| rt->u.dst.rt_next = rt_hash_table[hash].chain; |
| #if RT_CACHE_DEBUG >= 2 |
| if (rt->u.dst.rt_next) { |
| struct rtable *trt; |
| printk(KERN_DEBUG "rt_cache @%02x: %u.%u.%u.%u", hash, |
| NIPQUAD(rt->rt_dst)); |
| for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next) |
| printk(" . %u.%u.%u.%u", NIPQUAD(trt->rt_dst)); |
| printk("\n"); |
| } |
| #endif |
| rt_hash_table[hash].chain = rt; |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| *rp = rt; |
| return 0; |
| } |
| |
| void rt_bind_peer(struct rtable *rt, int create) |
| { |
| static DEFINE_SPINLOCK(rt_peer_lock); |
| struct inet_peer *peer; |
| |
| peer = inet_getpeer(rt->rt_dst, create); |
| |
| spin_lock_bh(&rt_peer_lock); |
| if (rt->peer == NULL) { |
| rt->peer = peer; |
| peer = NULL; |
| } |
| spin_unlock_bh(&rt_peer_lock); |
| if (peer) |
| inet_putpeer(peer); |
| } |
| |
| /* |
| * 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); |
| } |
| |
| static void rt_del(unsigned hash, struct rtable *rt) |
| { |
| struct rtable **rthp, *aux; |
| |
| rthp = &rt_hash_table[hash].chain; |
| spin_lock_bh(rt_hash_lock_addr(hash)); |
| ip_rt_put(rt); |
| while ((aux = *rthp) != NULL) { |
| if (aux == rt || (aux->rt_genid != atomic_read(&rt_genid))) { |
| *rthp = aux->u.dst.rt_next; |
| rt_free(aux); |
| continue; |
| } |
| rthp = &aux->u.dst.rt_next; |
| } |
| spin_unlock_bh(rt_hash_lock_addr(hash)); |
| } |
| |
| void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, |
| __be32 saddr, struct net_device *dev) |
| { |
| int i, k; |
| struct in_device *in_dev = in_dev_get(dev); |
| struct rtable *rth, **rthp; |
| __be32 skeys[2] = { saddr, 0 }; |
| int ikeys[2] = { dev->ifindex, 0 }; |
| struct netevent_redirect netevent; |
| 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; |
| } |
| |
| for (i = 0; i < 2; i++) { |
| for (k = 0; k < 2; k++) { |
| unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]); |
| |
| rthp=&rt_hash_table[hash].chain; |
| |
| rcu_read_lock(); |
| while ((rth = rcu_dereference(*rthp)) != NULL) { |
| struct rtable *rt; |
| |
| if (rth->fl.fl4_dst != daddr || |
| rth->fl.fl4_src != skeys[i] || |
| rth->fl.oif != ikeys[k] || |
| rth->fl.iif != 0 || |
| rth->rt_genid != atomic_read(&rt_genid) || |
| dev_net(rth->u.dst.dev) != net) { |
| rthp = &rth->u.dst.rt_next; |
| continue; |
| } |
| |
| if (rth->rt_dst != daddr || |
| rth->rt_src != saddr || |
| rth->u.dst.error || |
| rth->rt_gateway != old_gw || |
| rth->u.dst.dev != dev) |
| break; |
| |
| dst_hold(&rth->u.dst); |
| rcu_read_unlock(); |
| |
| rt = dst_alloc(&ipv4_dst_ops); |
| if (rt == NULL) { |
| ip_rt_put(rth); |
| in_dev_put(in_dev); |
| return; |
| } |
| |
| /* Copy all the information. */ |
| *rt = *rth; |
| INIT_RCU_HEAD(&rt->u.dst.rcu_head); |
| rt->u.dst.__use = 1; |
| atomic_set(&rt->u.dst.__refcnt, 1); |
| rt->u.dst.child = NULL; |
| if (rt->u.dst.dev) |
| dev_hold(rt->u.dst.dev); |
| if (rt->idev) |
| in_dev_hold(rt->idev); |
| rt->u.dst.obsolete = 0; |
| rt->u.dst.lastuse = jiffies; |
| rt->u.dst.path = &rt->u.dst; |
| rt->u.dst.neighbour = NULL; |
| rt->u.dst.hh = NULL; |
| rt->u.dst.xfrm = NULL; |
| rt->rt_genid = atomic_read(&rt_genid); |
| rt->rt_flags |= RTCF_REDIRECTED; |
| |
| /* Gateway is different ... */ |
| rt->rt_gateway = new_gw; |
| |
| /* Redirect received -> path was valid */ |
| dst_confirm(&rth->u.dst); |
| |
| if (rt->peer) |
| atomic_inc(&rt->peer->refcnt); |
| |
| if (arp_bind_neighbour(&rt->u.dst) || |
| !(rt->u.dst.neighbour->nud_state & |
| NUD_VALID)) { |
| if (rt->u.dst.neighbour) |
| neigh_event_send(rt->u.dst.neighbour, NULL); |
| ip_rt_put(rth); |
| rt_drop(rt); |
| goto do_next; |
| } |
| |
| netevent.old = &rth->u.dst; |
| netevent.new = &rt->u.dst; |
| call_netevent_notifiers(NETEVENT_REDIRECT, |
| &netevent); |
| |
| rt_del(hash, rth); |
| if (!rt_intern_hash(hash, rt, &rt)) |
| ip_rt_put(rt); |
| goto do_next; |
| } |
| rcu_read_unlock(); |
| do_next: |
| ; |
| } |
| } |
| in_dev_put(in_dev); |
| return; |
| |
| reject_redirect: |
| #ifdef CONFIG_IP_ROUTE_VERBOSE |
| if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) |
| printk(KERN_INFO "Redirect from %u.%u.%u.%u on %s about " |
| "%u.%u.%u.%u ignored.\n" |
| " Advised path = %u.%u.%u.%u -> %u.%u.%u.%u\n", |
| NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw), |
| NIPQUAD(saddr), NIPQUAD(daddr)); |
| #endif |
| in_dev_put(in_dev); |
| } |
| |
| 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) { |
| ip_rt_put(rt); |
| ret = NULL; |
| } else if ((rt->rt_flags & RTCF_REDIRECTED) || |
| rt->u.dst.expires) { |
| unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src, |
| rt->fl.oif); |
| #if RT_CACHE_DEBUG >= 1 |
| printk(KERN_DEBUG "ipv4_negative_advice: redirect to " |
| "%u.%u.%u.%u/%02x dropped\n", |
| NIPQUAD(rt->rt_dst), rt->fl.fl4_tos); |
| #endif |
| rt_del(hash, 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; |
| struct in_device *in_dev = in_dev_get(rt->u.dst.dev); |
| |
| if (!in_dev) |
| return; |
| |
| if (!IN_DEV_TX_REDIRECTS(in_dev)) |
| goto out; |
| |
| /* No redirected packets during ip_rt_redirect_silence; |
| * reset the algorithm. |
| */ |
| if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence)) |
| rt->u.dst.rate_tokens = 0; |
| |
| /* Too many ignored redirects; do not send anything |
| * set u.dst.rate_last to the last seen redirected packet. |
| */ |
| if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) { |
| rt->u.dst.rate_last = jiffies; |
| goto out; |
| } |
| |
| /* Check for load limit; set rate_last to the latest sent |
| * redirect. |
| */ |
| if (rt->u.dst.rate_tokens == 0 || |
| time_after(jiffies, |
| (rt->u.dst.rate_last + |
| (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) { |
| icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); |
| rt->u.dst.rate_last = jiffies; |
| ++rt->u.dst.rate_tokens; |
| #ifdef CONFIG_IP_ROUTE_VERBOSE |
| if (IN_DEV_LOG_MARTIANS(in_dev) && |
| rt->u.dst.rate_tokens == ip_rt_redirect_number && |
| net_ratelimit()) |
| printk(KERN_WARNING "host %u.%u.%u.%u/if%d ignores " |
| "redirects for %u.%u.%u.%u to %u.%u.%u.%u.\n", |
| NIPQUAD(rt->rt_src), rt->rt_iif, |
| NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway)); |
| #endif |
| } |
| out: |
| in_dev_put(in_dev); |
| } |
| |
| static int ip_error(struct sk_buff *skb) |
| { |
| struct rtable *rt = skb->rtable; |
| unsigned long now; |
| int code; |
| |
| switch (rt->u.dst.error) { |
| case EINVAL: |
| default: |
| goto out; |
| case EHOSTUNREACH: |
| code = ICMP_HOST_UNREACH; |
| break; |
| case ENETUNREACH: |
| code = ICMP_NET_UNREACH; |
| IP_INC_STATS_BH(IPSTATS_MIB_INNOROUTES); |
| break; |
| case EACCES: |
| code = ICMP_PKT_FILTERED; |
| break; |
| } |
| |
| now = jiffies; |
| rt->u.dst.rate_tokens += now - rt->u.dst.rate_last; |
| if (rt->u.dst.rate_tokens > ip_rt_error_burst) |
| rt->u.dst.rate_tokens = ip_rt_error_burst; |
| rt->u.dst.rate_last = now; |
| if (rt->u.dst.rate_tokens >= ip_rt_error_cost) { |
| rt->u.dst.rate_tokens -= ip_rt_error_cost; |
| 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, struct iphdr *iph, |
| unsigned short new_mtu) |
| { |
| int i; |
| unsigned short old_mtu = ntohs(iph->tot_len); |
| struct rtable *rth; |
| __be32 skeys[2] = { iph->saddr, 0, }; |
| __be32 daddr = iph->daddr; |
| unsigned short est_mtu = 0; |
| |
| if (ipv4_config.no_pmtu_disc) |
| return 0; |
| |
| for (i = 0; i < 2; i++) { |
| unsigned hash = rt_hash(daddr, skeys[i], 0); |
| |
| rcu_read_lock(); |
| for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; |
| rth = rcu_dereference(rth->u.dst.rt_next)) { |
| if (rth->fl.fl4_dst == daddr && |
| rth->fl.fl4_src == skeys[i] && |
| rth->rt_dst == daddr && |
| rth->rt_src == iph->saddr && |
| rth->fl.iif == 0 && |
| !(dst_metric_locked(&rth->u.dst, RTAX_MTU)) && |
| dev_net(rth->u.dst.dev) == net && |
| rth->rt_genid == atomic_read(&rt_genid)) { |
| unsigned short mtu = new_mtu; |
| |
| if (new_mtu < 68 || new_mtu >= old_mtu) { |
| |
| /* BSD 4.2 compatibility hack :-( */ |
| if (mtu == 0 && |
| old_mtu >= rth->u.dst.metrics[RTAX_MTU-1] && |
| old_mtu >= 68 + (iph->ihl << 2)) |
| old_mtu -= iph->ihl << 2; |
| |
| mtu = guess_mtu(old_mtu); |
| } |
| if (mtu <= rth->u.dst.metrics[RTAX_MTU-1]) { |
| if (mtu < rth->u.dst.metrics[RTAX_MTU-1]) { |
| dst_confirm(&rth->u.dst); |
| if (mtu < ip_rt_min_pmtu) { |
| mtu = ip_rt_min_pmtu; |
| rth->u.dst.metrics[RTAX_LOCK-1] |= |
| (1 << RTAX_MTU); |
| } |
| rth->u.dst.metrics[RTAX_MTU-1] = mtu; |
| dst_set_expires(&rth->u.dst, |
| ip_rt_mtu_expires); |
| } |
| est_mtu = mtu; |
| } |
| } |
| } |
| rcu_read_unlock(); |
| } |
| return est_mtu ? : new_mtu; |
| } |
| |
| static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) |
| { |
| if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= 68 && |
| !(dst_metric_locked(dst, RTAX_MTU))) { |
| if (mtu < ip_rt_min_pmtu) { |
| mtu = ip_rt_min_pmtu; |
| dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU); |
| } |
| dst->metrics[RTAX_MTU-1] = mtu; |
| dst_set_expires(dst, ip_rt_mtu_expires); |
| call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst); |
| } |
| } |
| |
| static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) |
| { |
| return NULL; |
| } |
| |
| static void ipv4_dst_destroy(struct dst_entry *dst) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| struct inet_peer *peer = rt->peer; |
| struct in_device *idev = rt->idev; |
| |
| if (peer) { |
| rt->peer = NULL; |
| inet_putpeer(peer); |
| } |
| |
| if (idev) { |
| rt->idev = NULL; |
| in_dev_put(idev); |
| } |
| } |
| |
| static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, |
| int how) |
| { |
| struct rtable *rt = (struct rtable *) dst; |
| struct in_device *idev = rt->idev; |
| if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) { |
| struct in_device *loopback_idev = |
| in_dev_get(dev_net(dev)->loopback_dev); |
| if (loopback_idev) { |
| rt->idev = loopback_idev; |
| in_dev_put(idev); |
| } |
| } |
| } |
| |
| 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; |
| if (rt) |
| dst_set_expires(&rt->u.dst, 0); |
| } |
| |
| static int ip_rt_bug(struct sk_buff *skb) |
| { |
| printk(KERN_DEBUG "ip_rt_bug: %u.%u.%u.%u -> %u.%u.%u.%u, %s\n", |
| NIPQUAD(ip_hdr(skb)->saddr), NIPQUAD(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->fl.iif == 0) |
| src = rt->rt_src; |
| else if (fib_lookup(dev_net(rt->u.dst.dev), &rt->fl, &res) == 0) { |
| src = FIB_RES_PREFSRC(res); |
| fib_res_put(&res); |
| } else |
| src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway, |
| RT_SCOPE_UNIVERSE); |
| memcpy(addr, &src, 4); |
| } |
| |
| #ifdef CONFIG_NET_CLS_ROUTE |
| static void set_class_tag(struct rtable *rt, u32 tag) |
| { |
| if (!(rt->u.dst.tclassid & 0xFFFF)) |
| rt->u.dst.tclassid |= tag & 0xFFFF; |
| if (!(rt->u.dst.tclassid & 0xFFFF0000)) |
| rt->u.dst.tclassid |= tag & 0xFFFF0000; |
| } |
| #endif |
| |
| static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag) |
| { |
| struct fib_info *fi = res->fi; |
| |
| if (fi) { |
| if (FIB_RES_GW(*res) && |
| FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) |
| rt->rt_gateway = FIB_RES_GW(*res); |
| memcpy(rt->u.dst.metrics, fi->fib_metrics, |
| sizeof(rt->u.dst.metrics)); |
| if (fi->fib_mtu == 0) { |
| rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu; |
| if (rt->u.dst.metrics[RTAX_LOCK-1] & (1 << RTAX_MTU) && |
| rt->rt_gateway != rt->rt_dst && |
| rt->u.dst.dev->mtu > 576) |
| rt->u.dst.metrics[RTAX_MTU-1] = 576; |
| } |
| #ifdef CONFIG_NET_CLS_ROUTE |
| rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid; |
| #endif |
| } else |
| rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu; |
| |
| if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0) |
| rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl; |
| if (rt->u.dst.metrics[RTAX_MTU-1] > IP_MAX_MTU) |
| rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU; |
| if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0) |
| rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40, |
| ip_rt_min_advmss); |
| if (rt->u.dst.metrics[RTAX_ADVMSS-1] > 65535 - 40) |
| rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40; |
| |
| #ifdef CONFIG_NET_CLS_ROUTE |
| #ifdef CONFIG_IP_MULTIPLE_TABLES |
| set_class_tag(rt, fib_rules_tclass(res)); |
| #endif |
| set_class_tag(rt, itag); |
| #endif |
| rt->rt_type = res->type; |
| } |
| |
| static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| u8 tos, struct net_device *dev, int our) |
| { |
| unsigned hash; |
| struct rtable *rth; |
| __be32 spec_dst; |
| struct in_device *in_dev = in_dev_get(dev); |
| u32 itag = 0; |
| |
| /* 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 if (fib_validate_source(saddr, 0, tos, 0, |
| dev, &spec_dst, &itag) < 0) |
| goto e_inval; |
| |
| rth = dst_alloc(&ipv4_dst_ops); |
| if (!rth) |
| goto e_nobufs; |
| |
| rth->u.dst.output= ip_rt_bug; |
| |
| atomic_set(&rth->u.dst.__refcnt, 1); |
| rth->u.dst.flags= DST_HOST; |
| if (IN_DEV_CONF_GET(in_dev, NOPOLICY)) |
| rth->u.dst.flags |= DST_NOPOLICY; |
| rth->fl.fl4_dst = daddr; |
| rth->rt_dst = daddr; |
| rth->fl.fl4_tos = tos; |
| rth->fl.mark = skb->mark; |
| rth->fl.fl4_src = saddr; |
| rth->rt_src = saddr; |
| #ifdef CONFIG_NET_CLS_ROUTE |
| rth->u.dst.tclassid = itag; |
| #endif |
| rth->rt_iif = |
| rth->fl.iif = dev->ifindex; |
| rth->u.dst.dev = init_net.loopback_dev; |
| dev_hold(rth->u.dst.dev); |
| rth->idev = in_dev_get(rth->u.dst.dev); |
| rth->fl.oif = 0; |
| rth->rt_gateway = daddr; |
| rth->rt_spec_dst= spec_dst; |
| rth->rt_genid = atomic_read(&rt_genid); |
| rth->rt_flags = RTCF_MULTICAST; |
| rth->rt_type = RTN_MULTICAST; |
| if (our) { |
| rth->u.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->u.dst.input = ip_mr_input; |
| #endif |
| RT_CACHE_STAT_INC(in_slow_mc); |
| |
| in_dev_put(in_dev); |
| hash = rt_hash(daddr, saddr, dev->ifindex); |
| return rt_intern_hash(hash, rth, &skb->rtable); |
| |
| e_nobufs: |
| in_dev_put(in_dev); |
| return -ENOBUFS; |
| |
| e_inval: |
| in_dev_put(in_dev); |
| return -EINVAL; |
| } |
| |
| |
| 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 %u.%u.%u.%u from " |
| "%u.%u.%u.%u, on dev %s\n", |
| NIPQUAD(daddr), NIPQUAD(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 |
| } |
| |
| static inline int __mkroute_input(struct sk_buff *skb, |
| 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 flags = 0; |
| __be32 spec_dst; |
| u32 itag; |
| |
| /* get a working reference to the output device */ |
| out_dev = in_dev_get(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(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); |
| |
| err = -EINVAL; |
| goto cleanup; |
| } |
| |
| if (err) |
| flags |= RTCF_DIRECTSRC; |
| |
| if (out_dev == in_dev && err && !(flags & RTCF_MASQ) && |
| (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. |
| */ |
| if (out_dev == in_dev) { |
| err = -EINVAL; |
| goto cleanup; |
| } |
| } |
| |
| |
| rth = dst_alloc(&ipv4_dst_ops); |
| if (!rth) { |
| err = -ENOBUFS; |
| goto cleanup; |
| } |
| |
| atomic_set(&rth->u.dst.__refcnt, 1); |
| rth->u.dst.flags= DST_HOST; |
| if (IN_DEV_CONF_GET(in_dev, NOPOLICY)) |
| rth->u.dst.flags |= DST_NOPOLICY; |
| if (IN_DEV_CONF_GET(out_dev, NOXFRM)) |
| rth->u.dst.flags |= DST_NOXFRM; |
| rth->fl.fl4_dst = daddr; |
| rth->rt_dst = daddr; |
| rth->fl.fl4_tos = tos; |
| rth->fl.mark = skb->mark; |
| rth->fl.fl4_src = saddr; |
| rth->rt_src = saddr; |
| rth->rt_gateway = daddr; |
| rth->rt_iif = |
| rth->fl.iif = in_dev->dev->ifindex; |
| rth->u.dst.dev = (out_dev)->dev; |
| dev_hold(rth->u.dst.dev); |
| rth->idev = in_dev_get(rth->u.dst.dev); |
| rth->fl.oif = 0; |
| rth->rt_spec_dst= spec_dst; |
| |
| rth->u.dst.input = ip_forward; |
| rth->u.dst.output = ip_output; |
| rth->rt_genid = atomic_read(&rt_genid); |
| |
| rt_set_nexthop(rth, res, itag); |
| |
| rth->rt_flags = flags; |
| |
| *result = rth; |
| err = 0; |
| cleanup: |
| /* release the working reference to the output device */ |
| in_dev_put(out_dev); |
| return err; |
| } |
| |
| static inline int ip_mkroute_input(struct sk_buff *skb, |
| struct fib_result* res, |
| const struct flowi *fl, |
| 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 && fl->oif == 0) |
| fib_select_multipath(fl, 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, fl->iif); |
| return rt_intern_hash(hash, rth, &skb->rtable); |
| } |
| |
| /* |
| * 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. |
| */ |
| |
| 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(dev); |
| struct flowi fl = { .nl_u = { .ip4_u = |
| { .daddr = daddr, |
| .saddr = saddr, |
| .tos = tos, |
| .scope = RT_SCOPE_UNIVERSE, |
| } }, |
| .mark = skb->mark, |
| .iif = dev->ifindex }; |
| unsigned flags = 0; |
| u32 itag = 0; |
| struct rtable * rth; |
| unsigned hash; |
| __be32 spec_dst; |
| int err = -EINVAL; |
| int free_res = 0; |
| 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 (daddr == htonl(0xFFFFFFFF) || (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_lbcast(daddr) || ipv4_is_zeronet(daddr) || |
| ipv4_is_loopback(daddr)) |
| goto martian_destination; |
| |
| /* |
| * Now we are ready to route packet. |
| */ |
| if ((err = fib_lookup(net, &fl, &res)) != 0) { |
| if (!IN_DEV_FORWARD(in_dev)) |
| goto e_hostunreach; |
| goto no_route; |
| } |
| free_res = 1; |
| |
| RT_CACHE_STAT_INC(in_slow_tot); |
| |
| if (res.type == RTN_BROADCAST) |
| goto brd_input; |
| |
| if (res.type == RTN_LOCAL) { |
| int result; |
| result = fib_validate_source(saddr, daddr, tos, |
| net->loopback_dev->ifindex, |
| dev, &spec_dst, &itag); |
| if (result < 0) |
| goto martian_source; |
| if (result) |
| 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, &fl, in_dev, daddr, saddr, tos); |
| done: |
| in_dev_put(in_dev); |
| if (free_res) |
| fib_res_put(&res); |
| 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(saddr, 0, tos, 0, dev, &spec_dst, |
| &itag); |
| if (err < 0) |
| goto martian_source; |
| if (err) |
| flags |= RTCF_DIRECTSRC; |
| } |
| flags |= RTCF_BROADCAST; |
| res.type = RTN_BROADCAST; |
| RT_CACHE_STAT_INC(in_brd); |
| |
| local_input: |
| rth = dst_alloc(&ipv4_dst_ops); |
| if (!rth) |
| goto e_nobufs; |
| |
| rth->u.dst.output= ip_rt_bug; |
| rth->rt_genid = atomic_read(&rt_genid); |
| |
| atomic_set(&rth->u.dst.__refcnt, 1); |
| rth->u.dst.flags= DST_HOST; |
| if (IN_DEV_CONF_GET(in_dev, NOPOLICY)) |
| rth->u.dst.flags |= DST_NOPOLICY; |
| rth->fl.fl4_dst = daddr; |
| rth->rt_dst = daddr; |
| rth->fl.fl4_tos = tos; |
| rth->fl.mark = skb->mark; |
| rth->fl.fl4_src = saddr; |
| rth->rt_src = saddr; |
| #ifdef CONFIG_NET_CLS_ROUTE |
| rth->u.dst.tclassid = itag; |
| #endif |
| rth->rt_iif = |
| rth->fl.iif = dev->ifindex; |
| rth->u.dst.dev = net->loopback_dev; |
| dev_hold(rth->u.dst.dev); |
| rth->idev = in_dev_get(rth->u.dst.dev); |
| rth->rt_gateway = daddr; |
| rth->rt_spec_dst= spec_dst; |
| rth->u.dst.input= ip_local_deliver; |
| rth->rt_flags = flags|RTCF_LOCAL; |
| if (res.type == RTN_UNREACHABLE) { |
| rth->u.dst.input= ip_error; |
| rth->u.dst.error= -err; |
| rth->rt_flags &= ~RTCF_LOCAL; |
| } |
| rth->rt_type = res.type; |
| hash = rt_hash(daddr, saddr, fl.iif); |
| err = rt_intern_hash(hash, rth, &skb->rtable); |
| goto done; |
| |
| 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 %u.%u.%u.%u from " |
| "%u.%u.%u.%u, dev %s\n", |
| NIPQUAD(daddr), NIPQUAD(saddr), dev->name); |
| #endif |
| |
| e_hostunreach: |
| err = -EHOSTUNREACH; |
| goto done; |
| |
| e_inval: |
| err = -EINVAL; |
| goto done; |
| |
| e_nobufs: |
| err = -ENOBUFS; |
| goto done; |
| |
| martian_source: |
| ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); |
| goto e_inval; |
| } |
| |
| int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr, |
| u8 tos, struct net_device *dev) |
| { |
| struct rtable * rth; |
| unsigned hash; |
| int iif = dev->ifindex; |
| struct net *net; |
| |
| net = dev_net(dev); |
| tos &= IPTOS_RT_MASK; |
| hash = rt_hash(daddr, saddr, iif); |
| |
| rcu_read_lock(); |
| for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; |
| rth = rcu_dereference(rth->u.dst.rt_next)) { |
| if (rth->fl.fl4_dst == daddr && |
| rth->fl.fl4_src == saddr && |
| rth->fl.iif == iif && |
| rth->fl.oif == 0 && |
| rth->fl.mark == skb->mark && |
| rth->fl.fl4_tos == tos && |
| dev_net(rth->u.dst.dev) == net && |
| rth->rt_genid == atomic_read(&rt_genid)) { |
| dst_use(&rth->u.dst, jiffies); |
| RT_CACHE_STAT_INC(in_hit); |
| rcu_read_unlock(); |
| skb->rtable = rth; |
| return 0; |
| } |
| RT_CACHE_STAT_INC(in_hlist_search); |
| } |
| rcu_read_unlock(); |
| |
| /* 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; |
| |
| rcu_read_lock(); |
| if ((in_dev = __in_dev_get_rcu(dev)) != NULL) { |
| int our = ip_check_mc(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 |
| ) { |
| rcu_read_unlock(); |
| return ip_route_input_mc(skb, daddr, saddr, |
| tos, dev, our); |
| } |
| } |
| rcu_read_unlock(); |
| return -EINVAL; |
| } |
| return ip_route_input_slow(skb, daddr, saddr, tos, dev); |
| } |
| |
| static inline int __mkroute_output(struct rtable **result, |
| struct fib_result* res, |
| const struct flowi *fl, |
| const struct flowi *oldflp, |
| struct net_device *dev_out, |
| unsigned flags) |
| { |
| struct rtable *rth; |
| struct in_device *in_dev; |
| u32 tos = RT_FL_TOS(oldflp); |
| int err = 0; |
| |
| if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK)) |
| return -EINVAL; |
| |
| if (fl->fl4_dst == htonl(0xFFFFFFFF)) |
| res->type = RTN_BROADCAST; |
| else if (ipv4_is_multicast(fl->fl4_dst)) |
| res->type = RTN_MULTICAST; |
| else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst)) |
| return -EINVAL; |
| |
| if (dev_out->flags & IFF_LOOPBACK) |
| flags |= RTCF_LOCAL; |
| |
| /* get work reference to inet device */ |
| in_dev = in_dev_get(dev_out); |
| if (!in_dev) |
| return -EINVAL; |
| |
| if (res->type == RTN_BROADCAST) { |
| flags |= RTCF_BROADCAST | RTCF_LOCAL; |
| if (res->fi) { |
| fib_info_put(res->fi); |
| res->fi = NULL; |
| } |
| } else if (res->type == RTN_MULTICAST) { |
| flags |= RTCF_MULTICAST|RTCF_LOCAL; |
| if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src, |
| oldflp->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 (res->fi && res->prefixlen < 4) { |
| fib_info_put(res->fi); |
| res->fi = NULL; |
| } |
| } |
| |
| |
| rth = dst_alloc(&ipv4_dst_ops); |
| if (!rth) { |
| err = -ENOBUFS; |
| goto cleanup; |
| } |
| |
| atomic_set(&rth->u.dst.__refcnt, 1); |
| rth->u.dst.flags= DST_HOST; |
| if (IN_DEV_CONF_GET(in_dev, NOXFRM)) |
| rth->u.dst.flags |= DST_NOXFRM; |
| if (IN_DEV_CONF_GET(in_dev, NOPOLICY)) |
| rth->u.dst.flags |= DST_NOPOLICY; |
| |
| rth->fl.fl4_dst = oldflp->fl4_dst; |
| rth->fl.fl4_tos = tos; |
| rth->fl.fl4_src = oldflp->fl4_src; |
| rth->fl.oif = oldflp->oif; |
| rth->fl.mark = oldflp->mark; |
| rth->rt_dst = fl->fl4_dst; |
| rth->rt_src = fl->fl4_src; |
| rth->rt_iif = oldflp->oif ? : dev_out->ifindex; |
| /* get references to the devices that are to be hold by the routing |
| cache entry */ |
| rth->u.dst.dev = dev_out; |
| dev_hold(dev_out); |
| rth->idev = in_dev_get(dev_out); |
| rth->rt_gateway = fl->fl4_dst; |
| rth->rt_spec_dst= fl->fl4_src; |
| |
| rth->u.dst.output=ip_output; |
| rth->rt_genid = atomic_read(&rt_genid); |
| |
| RT_CACHE_STAT_INC(out_slow_tot); |
| |
| if (flags & RTCF_LOCAL) { |
| rth->u.dst.input = ip_local_deliver; |
| rth->rt_spec_dst = fl->fl4_dst; |
| } |
| if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
| rth->rt_spec_dst = fl->fl4_src; |
| if (flags & RTCF_LOCAL && |
| !(dev_out->flags & IFF_LOOPBACK)) { |
| rth->u.dst.output = ip_mc_output; |
| RT_CACHE_STAT_INC(out_slow_mc); |
| } |
| #ifdef CONFIG_IP_MROUTE |
| if (res->type == RTN_MULTICAST) { |
| if (IN_DEV_MFORWARD(in_dev) && |
| !ipv4_is_local_multicast(oldflp->fl4_dst)) { |
| rth->u.dst.input = ip_mr_input; |
| rth->u.dst.output = ip_mc_output; |
| } |
| } |
| #endif |
| } |
| |
| rt_set_nexthop(rth, res, 0); |
| |
| rth->rt_flags = flags; |
| |
| *result = rth; |
| cleanup: |
| /* release work reference to inet device */ |
| in_dev_put(in_dev); |
| |
| return err; |
| } |
| |
| static inline int ip_mkroute_output(struct rtable **rp, |
| struct fib_result* res, |
| const struct flowi *fl, |
| const struct flowi *oldflp, |
| struct net_device *dev_out, |
| unsigned flags) |
| { |
| struct rtable *rth = NULL; |
| int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags); |
| unsigned hash; |
| if (err == 0) { |
| hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif); |
| err = rt_intern_hash(hash, rth, rp); |
| } |
| |
| return err; |
| } |
| |
| /* |
| * Major route resolver routine. |
| */ |
| |
| static int ip_route_output_slow(struct net *net, struct rtable **rp, |
| const struct flowi *oldflp) |
| { |
| u32 tos = RT_FL_TOS(oldflp); |
| struct flowi fl = { .nl_u = { .ip4_u = |
| { .daddr = oldflp->fl4_dst, |
| .saddr = oldflp->fl4_src, |
| .tos = tos & IPTOS_RT_MASK, |
| .scope = ((tos & RTO_ONLINK) ? |
| RT_SCOPE_LINK : |
| RT_SCOPE_UNIVERSE), |
| } }, |
| .mark = oldflp->mark, |
| .iif = net->loopback_dev->ifindex, |
| .oif = oldflp->oif }; |
| struct fib_result res; |
| unsigned flags = 0; |
| struct net_device *dev_out = NULL; |
| int free_res = 0; |
| int err; |
| |
| |
| res.fi = NULL; |
| #ifdef CONFIG_IP_MULTIPLE_TABLES |
| res.r = NULL; |
| #endif |
| |
| if (oldflp->fl4_src) { |
| err = -EINVAL; |
| if (ipv4_is_multicast(oldflp->fl4_src) || |
| ipv4_is_lbcast(oldflp->fl4_src) || |
| ipv4_is_zeronet(oldflp->fl4_src)) |
| goto out; |
| |
| /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ |
| dev_out = ip_dev_find(net, oldflp->fl4_src); |
| if (dev_out == NULL) |
| 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 (oldflp->oif == 0 |
| && (ipv4_is_multicast(oldflp->fl4_dst) || |
| oldflp->fl4_dst == htonl(0xFFFFFFFF))) { |
| /* 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. |
| */ |
| |
| fl.oif = dev_out->ifindex; |
| goto make_route; |
| } |
| if (dev_out) |
| dev_put(dev_out); |
| dev_out = NULL; |
| } |
| |
| |
| if (oldflp->oif) { |
| dev_out = dev_get_by_index(net, oldflp->oif); |
| err = -ENODEV; |
| if (dev_out == NULL) |
| goto out; |
| |
| /* RACE: Check return value of inet_select_addr instead. */ |
| if (__in_dev_get_rtnl(dev_out) == NULL) { |
| dev_put(dev_out); |
| goto out; /* Wrong error code */ |
| } |
| |
| if (ipv4_is_local_multicast(oldflp->fl4_dst) || |
| oldflp->fl4_dst == htonl(0xFFFFFFFF)) { |
| if (!fl.fl4_src) |
| fl.fl4_src = inet_select_addr(dev_out, 0, |
| RT_SCOPE_LINK); |
| goto make_route; |
| } |
| if (!fl.fl4_src) { |
| if (ipv4_is_multicast(oldflp->fl4_dst)) |
| fl.fl4_src = inet_select_addr(dev_out, 0, |
| fl.fl4_scope); |
| else if (!oldflp->fl4_dst) |
| fl.fl4_src = inet_select_addr(dev_out, 0, |
| RT_SCOPE_HOST); |
| } |
| } |
| |
| if (!fl.fl4_dst) { |
| fl.fl4_dst = fl.fl4_src; |
| if (!fl.fl4_dst) |
| fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK); |
| if (dev_out) |
| dev_put(dev_out); |
| dev_out = net->loopback_dev; |
| dev_hold(dev_out); |
| fl.oif = net->loopback_dev->ifindex; |
| res.type = RTN_LOCAL; |
| flags |= RTCF_LOCAL; |
| goto make_route; |
| } |
| |
| if (fib_lookup(net, &fl, &res)) { |
| res.fi = NULL; |
| if (oldflp->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 (fl.fl4_src == 0) |
| fl.fl4_src = inet_select_addr(dev_out, 0, |
| RT_SCOPE_LINK); |
| res.type = RTN_UNICAST; |
| goto make_route; |
| } |
| if (dev_out) |
| dev_put(dev_out); |
| err = -ENETUNREACH; |
| goto out; |
| } |
| free_res = 1; |
| |
| if (res.type == RTN_LOCAL) { |
| if (!fl.fl4_src) |
| fl.fl4_src = fl.fl4_dst; |
| if (dev_out) |
| dev_put(dev_out); |
| dev_out = net->loopback_dev; |
| dev_hold(dev_out); |
| fl.oif = dev_out->ifindex; |
| if (res.fi) |
| fib_info_put(res.fi); |
| res.fi = NULL; |
| flags |= RTCF_LOCAL; |
| goto make_route; |
| } |
| |
| #ifdef CONFIG_IP_ROUTE_MULTIPATH |
| if (res.fi->fib_nhs > 1 && fl.oif == 0) |
| fib_select_multipath(&fl, &res); |
| else |
| #endif |
| if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif) |
| fib_select_default(net, &fl, &res); |
| |
| if (!fl.fl4_src) |
| fl.fl4_src = FIB_RES_PREFSRC(res); |
| |
| if (dev_out) |
| dev_put(dev_out); |
| dev_out = FIB_RES_DEV(res); |
| dev_hold(dev_out); |
| fl.oif = dev_out->ifindex; |
| |
| |
| make_route: |
| err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags); |
| |
| |
| if (free_res) |
| fib_res_put(&res); |
| if (dev_out) |
| dev_put(dev_out); |
| out: return err; |
| } |
| |
| int __ip_route_output_key(struct net *net, struct rtable **rp, |
| const struct flowi *flp) |
| { |
| unsigned hash; |
| struct rtable *rth; |
| |
| hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif); |
| |
| rcu_read_lock_bh(); |
| for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; |
| rth = rcu_dereference(rth->u.dst.rt_next)) { |
| if (rth->fl.fl4_dst == flp->fl4_dst && |
| rth->fl.fl4_src == flp->fl4_src && |
| rth->fl.iif == 0 && |
| rth->fl.oif == flp->oif && |
| rth->fl.mark == flp->mark && |
| !((rth->fl.fl4_tos ^ flp->fl4_tos) & |
| (IPTOS_RT_MASK | RTO_ONLINK)) && |
| dev_net(rth->u.dst.dev) == net && |
| rth->rt_genid == atomic_read(&rt_genid)) { |
| dst_use(&rth->u.dst, jiffies); |
| RT_CACHE_STAT_INC(out_hit); |
| rcu_read_unlock_bh(); |
| *rp = rth; |
| return 0; |
| } |
| RT_CACHE_STAT_INC(out_hlist_search); |
| } |
| rcu_read_unlock_bh(); |
| |
| return ip_route_output_slow(net, rp, flp); |
| } |
| |
| EXPORT_SYMBOL_GPL(__ip_route_output_key); |
| |
| static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) |
| { |
| } |
| |
| static struct dst_ops ipv4_dst_blackhole_ops = { |
| .family = AF_INET, |
| .protocol = __constant_htons(ETH_P_IP), |
| .destroy = ipv4_dst_destroy, |
| .check = ipv4_dst_check, |
| .update_pmtu = ipv4_rt_blackhole_update_pmtu, |
| .entry_size = sizeof(struct rtable), |
| .entries = ATOMIC_INIT(0), |
| }; |
| |
| |
| static int ipv4_dst_blackhole(struct rtable **rp, struct flowi *flp) |
| { |
| struct rtable *ort = *rp; |
| struct rtable *rt = (struct rtable *) |
| dst_alloc(&ipv4_dst_blackhole_ops); |
| |
| if (rt) { |
| struct dst_entry *new = &rt->u.dst; |
| |
| atomic_set(&new->__refcnt, 1); |
| new->__use = 1; |
| new->input = dst_discard; |
| new->output = dst_discard; |
| memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32)); |
| |
| new->dev = ort->u.dst.dev; |
| if (new->dev) |
| dev_hold(new->dev); |
| |
| rt->fl = ort->fl; |
| |
| rt->idev = ort->idev; |
| if (rt->idev) |
| in_dev_hold(rt->idev); |
| rt->rt_genid = atomic_read(&rt_genid); |
| 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_iif = ort->rt_iif; |
| 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); |
| |
| dst_free(new); |
| } |
| |
| dst_release(&(*rp)->u.dst); |
| *rp = rt; |
| return (rt ? 0 : -ENOMEM); |
| } |
| |
| int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp, |
| struct sock *sk, int flags) |
| { |
| int err; |
| |
| if ((err = __ip_route_output_key(net, rp, flp)) != 0) |
| return err; |
| |
| if (flp->proto) { |
| if (!flp->fl4_src) |
| flp->fl4_src = (*rp)->rt_src; |
| if (!flp->fl4_dst) |
| flp->fl4_dst = (*rp)->rt_dst; |
| err = __xfrm_lookup((struct dst_entry **)rp, flp, sk, |
| flags ? XFRM_LOOKUP_WAIT : 0); |
| if (err == -EREMOTE) |
| err = ipv4_dst_blackhole(rp, flp); |
| |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| EXPORT_SYMBOL_GPL(ip_route_output_flow); |
| |
| int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp) |
| { |
| return ip_route_output_flow(net, rp, flp, NULL, 0); |
| } |
| |
| static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event, |
| int nowait, unsigned int flags) |
| { |
| struct rtable *rt = skb->rtable; |
| 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->fl.fl4_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->fl.fl4_src) { |
| r->rtm_src_len = 32; |
| NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src); |
| } |
| if (rt->u.dst.dev) |
| NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex); |
| #ifdef CONFIG_NET_CLS_ROUTE |
| if (rt->u.dst.tclassid) |
| NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid); |
| #endif |
| if (rt->fl.iif) |
| NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst); |
| else if (rt->rt_src != rt->fl.fl4_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, rt->u.dst.metrics) < 0) |
| goto nla_put_failure; |
| |
| error = rt->u.dst.error; |
| expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0; |
| if (rt->peer) { |
| id = rt->peer->ip_id_count; |
| if (rt->peer->tcp_ts_stamp) { |
| ts = rt->peer->tcp_ts; |
| tsage = get_seconds() - rt->peer->tcp_ts_stamp; |
| } |
| } |
| |
| if (rt->fl.iif) { |
| #ifdef CONFIG_IP_MROUTE |
| __be32 dst = rt->rt_dst; |
| |
| if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && |
| IPV4_DEVCONF_ALL(&init_net, MC_FORWARDING)) { |
| int err = ipmr_get_route(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->fl.iif); |
| } |
| |
| if (rtnl_put_cacheinfo(skb, &rt->u.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; |
| 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; |
| |
| 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; |
| local_bh_disable(); |
| err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); |
| local_bh_enable(); |
| |
| rt = skb->rtable; |
| if (err == 0 && rt->u.dst.error) |
| err = -rt->u.dst.error; |
| } else { |
| struct flowi fl = { |
| .nl_u = { |
| .ip4_u = { |
| .daddr = dst, |
| .saddr = src, |
| .tos = rtm->rtm_tos, |
| }, |
| }, |
| .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0, |
| }; |
| err = ip_route_output_key(net, &rt, &fl); |
| } |
| |
| if (err) |
| goto errout_free; |
| |
| skb->rtable = rt; |
| if (rtm->rtm_flags & RTM_F_NOTIFY) |
| rt->rt_flags |= RTCF_NOTIFY; |
| |
| err = rt_fill_info(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++) { |
| rcu_read_lock_bh(); |
| for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt; |
| rt = rcu_dereference(rt->u.dst.rt_next), idx++) { |
| if (dev_net(rt->u.dst.dev) != net || idx < s_idx) |
| continue; |
| if (rt->rt_genid != atomic_read(&rt_genid)) |
| continue; |
| skb->dst = dst_clone(&rt->u.dst); |
| if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid, |
| cb->nlh->nlmsg_seq, RTM_NEWROUTE, |
| 1, NLM_F_MULTI) <= 0) { |
| dst_release(xchg(&skb->dst, NULL)); |
| rcu_read_unlock_bh(); |
| goto done; |
| } |
| dst_release(xchg(&skb->dst, NULL)); |
| } |
| rcu_read_unlock_bh(); |
| s_idx = 0; |
| } |
| |
| 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(0); |
| } |
| |
| #ifdef CONFIG_SYSCTL |
| static int flush_delay; |
| |
| static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write, |
| struct file *filp, void __user *buffer, |
| size_t *lenp, loff_t *ppos) |
| { |
| if (write) { |
| proc_dointvec(ctl, write, filp, buffer, lenp, ppos); |
| rt_cache_flush(flush_delay); |
| return 0; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table, |
| int __user *name, |
| int nlen, |
| void __user *oldval, |
| size_t __user *oldlenp, |
| void __user *newval, |
| size_t newlen) |
| { |
| int delay; |
| if (newlen != sizeof(int)) |
| return -EINVAL; |
| if (get_user(delay, (int __user *)newval)) |
| return -EFAULT; |
| rt_cache_flush(delay); |
| return 0; |
| } |
| |
| ctl_table ipv4_route_table[] = { |
| { |
| .ctl_name = NET_IPV4_ROUTE_FLUSH, |
| .procname = "flush", |
| .data = &flush_delay, |
| .maxlen = sizeof(int), |
| .mode = 0200, |
| .proc_handler = &ipv4_sysctl_rtcache_flush, |
| .strategy = &ipv4_sysctl_rtcache_flush_strategy, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_GC_THRESH, |
| .procname = "gc_thresh", |
| .data = &ipv4_dst_ops.gc_thresh, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_MAX_SIZE, |
| .procname = "max_size", |
| .data = &ip_rt_max_size, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| /* Deprecated. Use gc_min_interval_ms */ |
| |
| .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL, |
| .procname = "gc_min_interval", |
| .data = &ip_rt_gc_min_interval, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec_jiffies, |
| .strategy = &sysctl_jiffies, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS, |
| .procname = "gc_min_interval_ms", |
| .data = &ip_rt_gc_min_interval, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec_ms_jiffies, |
| .strategy = &sysctl_ms_jiffies, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT, |
| .procname = "gc_timeout", |
| .data = &ip_rt_gc_timeout, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec_jiffies, |
| .strategy = &sysctl_jiffies, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL, |
| .procname = "gc_interval", |
| .data = &ip_rt_gc_interval, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec_jiffies, |
| .strategy = &sysctl_jiffies, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD, |
| .procname = "redirect_load", |
| .data = &ip_rt_redirect_load, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER, |
| .procname = "redirect_number", |
| .data = &ip_rt_redirect_number, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE, |
| .procname = "redirect_silence", |
| .data = &ip_rt_redirect_silence, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_ERROR_COST, |
| .procname = "error_cost", |
| .data = &ip_rt_error_cost, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_ERROR_BURST, |
| .procname = "error_burst", |
| .data = &ip_rt_error_burst, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY, |
| .procname = "gc_elasticity", |
| .data = &ip_rt_gc_elasticity, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES, |
| .procname = "mtu_expires", |
| .data = &ip_rt_mtu_expires, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec_jiffies, |
| .strategy = &sysctl_jiffies, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_MIN_PMTU, |
| .procname = "min_pmtu", |
| .data = &ip_rt_min_pmtu, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS, |
| .procname = "min_adv_mss", |
| .data = &ip_rt_min_advmss, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec, |
| }, |
| { |
| .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL, |
| .procname = "secret_interval", |
| .data = &ip_rt_secret_interval, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = &proc_dointvec_jiffies, |
| .strategy = &sysctl_jiffies, |
| }, |
| { .ctl_name = 0 } |
| }; |
| #endif |
| |
| #ifdef CONFIG_NET_CLS_ROUTE |
| struct ip_rt_acct *ip_rt_acct __read_mostly; |
| #endif /* CONFIG_NET_CLS_ROUTE */ |
| |
| 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; |
| |
| atomic_set(&rt_genid, (int) ((num_physpages ^ (num_physpages>>8)) ^ |
| (jiffies ^ (jiffies >> 7)))); |
| |
| #ifdef CONFIG_NET_CLS_ROUTE |
| ip_rt_acct = __alloc_percpu(256 * sizeof(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; |
| |
| rt_hash_table = (struct rt_hash_bucket *) |
| alloc_large_system_hash("IP route cache", |
| sizeof(struct rt_hash_bucket), |
| rhash_entries, |
| (num_physpages >= 128 * 1024) ? |
| 15 : 17, |
| 0, |
| &rt_hash_log, |
| &rt_hash_mask, |
| 0); |
| 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(); |
| |
| setup_timer(&rt_secret_timer, rt_secret_rebuild, 0); |
| |
| /* All the timers, started at system startup tend |
| to synchronize. Perturb it a bit. |
| */ |
| schedule_delayed_work(&expires_work, |
| net_random() % ip_rt_gc_interval + ip_rt_gc_interval); |
| |
| rt_secret_timer.expires = jiffies + net_random() % ip_rt_secret_interval + |
| ip_rt_secret_interval; |
| add_timer(&rt_secret_timer); |
| |
| if (ip_rt_proc_init()) |
| printk(KERN_ERR "Unable to create route proc files\n"); |
| #ifdef CONFIG_XFRM |
| xfrm_init(); |
| xfrm4_init(); |
| #endif |
| rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL); |
| |
| return rc; |
| } |
| |
| EXPORT_SYMBOL(__ip_select_ident); |
| EXPORT_SYMBOL(ip_route_input); |
| EXPORT_SYMBOL(ip_route_output_key); |