diff options
Diffstat (limited to 'kernel/net/ipv4/route.c')
| -rw-r--r-- | kernel/net/ipv4/route.c | 2800 |
1 files changed, 2800 insertions, 0 deletions
diff --git a/kernel/net/ipv4/route.c b/kernel/net/ipv4/route.c new file mode 100644 index 000000000..f45f2a12f --- /dev/null +++ b/kernel/net/ipv4/route.c @@ -0,0 +1,2800 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * ROUTE - implementation of the IP router. + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * Linus Torvalds, <Linus.Torvalds@helsinki.fi> + * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + * Fixes: + * Alan Cox : Verify area fixes. + * Alan Cox : cli() protects routing changes + * Rui Oliveira : ICMP routing table updates + * (rco@di.uminho.pt) Routing table insertion and update + * Linus Torvalds : Rewrote bits to be sensible + * Alan Cox : Added BSD route gw semantics + * Alan Cox : Super /proc >4K + * Alan Cox : MTU in route table + * Alan Cox : MSS actually. Also added the window + * clamper. + * Sam Lantinga : Fixed route matching in rt_del() + * Alan Cox : Routing cache support. + * Alan Cox : Removed compatibility cruft. + * Alan Cox : RTF_REJECT support. + * Alan Cox : TCP irtt support. + * Jonathan Naylor : Added Metric support. + * Miquel van Smoorenburg : BSD API fixes. + * Miquel van Smoorenburg : Metrics. + * Alan Cox : Use __u32 properly + * Alan Cox : Aligned routing errors more closely with BSD + * our system is still very different. + * Alan Cox : Faster /proc handling + * Alexey Kuznetsov : Massive rework to support tree based routing, + * routing caches and better behaviour. + * + * Olaf Erb : irtt wasn't being copied right. + * Bjorn Ekwall : Kerneld route support. + * Alan Cox : Multicast fixed (I hope) + * Pavel Krauz : Limited broadcast fixed + * Mike McLagan : Routing by source + * Alexey Kuznetsov : End of old history. Split to fib.c and + * route.c and rewritten from scratch. + * Andi Kleen : Load-limit warning messages. + * Vitaly E. Lavrov : Transparent proxy revived after year coma. + * Vitaly E. Lavrov : Race condition in ip_route_input_slow. + * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. + * Vladimir V. Ivanov : IP rule info (flowid) is really useful. + * Marc Boucher : routing by fwmark + * Robert Olsson : Added rt_cache statistics + * Arnaldo C. Melo : Convert proc stuff to seq_file + * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. + * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect + * Ilia Sotnikov : Removed TOS from hash calculations + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#define pr_fmt(fmt) "IPv4: " fmt + +#include <linux/module.h> +#include <asm/uaccess.h> +#include <linux/bitops.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/proc_fs.h> +#include <linux/init.h> +#include <linux/skbuff.h> +#include <linux/inetdevice.h> +#include <linux/igmp.h> +#include <linux/pkt_sched.h> +#include <linux/mroute.h> +#include <linux/netfilter_ipv4.h> +#include <linux/random.h> +#include <linux/rcupdate.h> +#include <linux/times.h> +#include <linux/slab.h> +#include <linux/jhash.h> +#include <net/dst.h> +#include <net/net_namespace.h> +#include <net/protocol.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/inetpeer.h> +#include <net/sock.h> +#include <net/ip_fib.h> +#include <net/arp.h> +#include <net/tcp.h> +#include <net/icmp.h> +#include <net/xfrm.h> +#include <net/netevent.h> +#include <net/rtnetlink.h> +#ifdef CONFIG_SYSCTL +#include <linux/sysctl.h> +#include <linux/kmemleak.h> +#endif +#include <net/secure_seq.h> + +#define RT_FL_TOS(oldflp4) \ + ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) + +#define RT_GC_TIMEOUT (300*HZ) + +static int ip_rt_max_size; +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_mtu_expires __read_mostly = 10 * 60 * HZ; +static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; +static int ip_rt_min_advmss __read_mostly = 256; + +/* + * Interface to generic destination cache. + */ + +static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); +static unsigned int ipv4_default_advmss(const struct dst_entry *dst); +static unsigned int ipv4_mtu(const struct dst_entry *dst); +static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); +static void ipv4_link_failure(struct sk_buff *skb); +static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu); +static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb); +static void ipv4_dst_destroy(struct dst_entry *dst); + +static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) +{ + WARN_ON(1); + return NULL; +} + +static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, + struct sk_buff *skb, + const void *daddr); + +static struct dst_ops ipv4_dst_ops = { + .family = AF_INET, + .check = ipv4_dst_check, + .default_advmss = ipv4_default_advmss, + .mtu = ipv4_mtu, + .cow_metrics = ipv4_cow_metrics, + .destroy = ipv4_dst_destroy, + .negative_advice = ipv4_negative_advice, + .link_failure = ipv4_link_failure, + .update_pmtu = ip_rt_update_pmtu, + .redirect = ip_do_redirect, + .local_out = __ip_local_out, + .neigh_lookup = ipv4_neigh_lookup, +}; + +#define ECN_OR_COST(class) TC_PRIO_##class + +const __u8 ip_tos2prio[16] = { + TC_PRIO_BESTEFFORT, + ECN_OR_COST(BESTEFFORT), + TC_PRIO_BESTEFFORT, + ECN_OR_COST(BESTEFFORT), + TC_PRIO_BULK, + ECN_OR_COST(BULK), + TC_PRIO_BULK, + ECN_OR_COST(BULK), + TC_PRIO_INTERACTIVE, + ECN_OR_COST(INTERACTIVE), + TC_PRIO_INTERACTIVE, + ECN_OR_COST(INTERACTIVE), + TC_PRIO_INTERACTIVE_BULK, + ECN_OR_COST(INTERACTIVE_BULK), + TC_PRIO_INTERACTIVE_BULK, + ECN_OR_COST(INTERACTIVE_BULK) +}; +EXPORT_SYMBOL(ip_tos2prio); + +static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); +#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) + +#ifdef CONFIG_PROC_FS +static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) +{ + if (*pos) + return NULL; + return SEQ_START_TOKEN; +} + +static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + ++*pos; + return NULL; +} + +static void rt_cache_seq_stop(struct seq_file *seq, void *v) +{ +} + +static int rt_cache_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_printf(seq, "%-127s\n", + "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" + "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" + "HHUptod\tSpecDst"); + return 0; +} + +static const struct seq_operations rt_cache_seq_ops = { + .start = rt_cache_seq_start, + .next = rt_cache_seq_next, + .stop = rt_cache_seq_stop, + .show = rt_cache_seq_show, +}; + +static int rt_cache_seq_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &rt_cache_seq_ops); +} + +static const struct file_operations rt_cache_seq_fops = { + .owner = THIS_MODULE, + .open = rt_cache_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + + +static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) +{ + int cpu; + + if (*pos == 0) + return SEQ_START_TOKEN; + + for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { + if (!cpu_possible(cpu)) + continue; + *pos = cpu+1; + return &per_cpu(rt_cache_stat, cpu); + } + return NULL; +} + +static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + int cpu; + + for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { + if (!cpu_possible(cpu)) + continue; + *pos = cpu+1; + return &per_cpu(rt_cache_stat, cpu); + } + return NULL; + +} + +static void rt_cpu_seq_stop(struct seq_file *seq, void *v) +{ + +} + +static int rt_cpu_seq_show(struct seq_file *seq, void *v) +{ + struct rt_cache_stat *st = v; + + if (v == SEQ_START_TOKEN) { + seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); + return 0; + } + + seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " + " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", + dst_entries_get_slow(&ipv4_dst_ops), + 0, /* 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, + + 0, /* st->out_hit */ + st->out_slow_tot, + st->out_slow_mc, + + 0, /* st->gc_total */ + 0, /* st->gc_ignored */ + 0, /* st->gc_goal_miss */ + 0, /* st->gc_dst_overflow */ + 0, /* st->in_hlist_search */ + 0 /* 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_create("rt_cache", S_IRUGO, net->proc_net, + &rt_cache_seq_fops); + if (!pde) + goto err1; + + pde = proc_create("rt_cache", S_IRUGO, + net->proc_net_stat, &rt_cpu_seq_fops); + if (!pde) + goto err2; + +#ifdef CONFIG_IP_ROUTE_CLASSID + pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); + if (!pde) + goto err3; +#endif + return 0; + +#ifdef CONFIG_IP_ROUTE_CLASSID +err3: + remove_proc_entry("rt_cache", net->proc_net_stat); +#endif +err2: + remove_proc_entry("rt_cache", net->proc_net); +err1: + return -ENOMEM; +} + +static void __net_exit ip_rt_do_proc_exit(struct net *net) +{ + remove_proc_entry("rt_cache", net->proc_net_stat); + remove_proc_entry("rt_cache", net->proc_net); +#ifdef CONFIG_IP_ROUTE_CLASSID + remove_proc_entry("rt_acct", net->proc_net); +#endif +} + +static struct pernet_operations ip_rt_proc_ops __net_initdata = { + .init = ip_rt_do_proc_init, + .exit = ip_rt_do_proc_exit, +}; + +static int __init ip_rt_proc_init(void) +{ + return register_pernet_subsys(&ip_rt_proc_ops); +} + +#else +static inline int ip_rt_proc_init(void) +{ + return 0; +} +#endif /* CONFIG_PROC_FS */ + +static inline bool rt_is_expired(const struct rtable *rth) +{ + return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); +} + +void rt_cache_flush(struct net *net) +{ + rt_genid_bump_ipv4(net); +} + +static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, + struct sk_buff *skb, + const void *daddr) +{ + struct net_device *dev = dst->dev; + const __be32 *pkey = daddr; + const struct rtable *rt; + struct neighbour *n; + + rt = (const struct rtable *) dst; + if (rt->rt_gateway) + pkey = (const __be32 *) &rt->rt_gateway; + else if (skb) + pkey = &ip_hdr(skb)->daddr; + + n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); + if (n) + return n; + return neigh_create(&arp_tbl, pkey, dev); +} + +#define IP_IDENTS_SZ 2048u +struct ip_ident_bucket { + atomic_t id; + u32 stamp32; +}; + +static struct ip_ident_bucket *ip_idents __read_mostly; + +/* In order to protect privacy, we add a perturbation to identifiers + * if one generator is seldom used. This makes hard for an attacker + * to infer how many packets were sent between two points in time. + */ +u32 ip_idents_reserve(u32 hash, int segs) +{ + struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ; + u32 old = ACCESS_ONCE(bucket->stamp32); + u32 now = (u32)jiffies; + u32 delta = 0; + + if (old != now && cmpxchg(&bucket->stamp32, old, now) == old) + delta = prandom_u32_max(now - old); + + return atomic_add_return(segs + delta, &bucket->id) - segs; +} +EXPORT_SYMBOL(ip_idents_reserve); + +void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) +{ + static u32 ip_idents_hashrnd __read_mostly; + u32 hash, id; + + net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd)); + + hash = jhash_3words((__force u32)iph->daddr, + (__force u32)iph->saddr, + iph->protocol ^ net_hash_mix(net), + ip_idents_hashrnd); + id = ip_idents_reserve(hash, segs); + iph->id = htons(id); +} +EXPORT_SYMBOL(__ip_select_ident); + +static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk, + const struct iphdr *iph, + int oif, u8 tos, + u8 prot, u32 mark, int flow_flags) +{ + if (sk) { + const struct inet_sock *inet = inet_sk(sk); + + oif = sk->sk_bound_dev_if; + mark = sk->sk_mark; + tos = RT_CONN_FLAGS(sk); + prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; + } + flowi4_init_output(fl4, oif, mark, tos, + RT_SCOPE_UNIVERSE, prot, + flow_flags, + iph->daddr, iph->saddr, 0, 0); +} + +static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, + const struct sock *sk) +{ + const struct iphdr *iph = ip_hdr(skb); + int oif = skb->dev->ifindex; + u8 tos = RT_TOS(iph->tos); + u8 prot = iph->protocol; + u32 mark = skb->mark; + + __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0); +} + +static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) +{ + const struct inet_sock *inet = inet_sk(sk); + const struct ip_options_rcu *inet_opt; + __be32 daddr = inet->inet_daddr; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, + RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, + inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, + inet_sk_flowi_flags(sk), + daddr, inet->inet_saddr, 0, 0); + rcu_read_unlock(); +} + +static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, + const struct sk_buff *skb) +{ + if (skb) + build_skb_flow_key(fl4, skb, sk); + else + build_sk_flow_key(fl4, sk); +} + +static inline void rt_free(struct rtable *rt) +{ + call_rcu(&rt->dst.rcu_head, dst_rcu_free); +} + +static DEFINE_SPINLOCK(fnhe_lock); + +static void fnhe_flush_routes(struct fib_nh_exception *fnhe) +{ + struct rtable *rt; + + rt = rcu_dereference(fnhe->fnhe_rth_input); + if (rt) { + RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); + rt_free(rt); + } + rt = rcu_dereference(fnhe->fnhe_rth_output); + if (rt) { + RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); + rt_free(rt); + } +} + +static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) +{ + struct fib_nh_exception *fnhe, *oldest; + + oldest = rcu_dereference(hash->chain); + for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; + fnhe = rcu_dereference(fnhe->fnhe_next)) { + if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) + oldest = fnhe; + } + fnhe_flush_routes(oldest); + return oldest; +} + +static inline u32 fnhe_hashfun(__be32 daddr) +{ + static u32 fnhe_hashrnd __read_mostly; + u32 hval; + + net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); + hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); + return hash_32(hval, FNHE_HASH_SHIFT); +} + +static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) +{ + rt->rt_pmtu = fnhe->fnhe_pmtu; + rt->dst.expires = fnhe->fnhe_expires; + + if (fnhe->fnhe_gw) { + rt->rt_flags |= RTCF_REDIRECTED; + rt->rt_gateway = fnhe->fnhe_gw; + rt->rt_uses_gateway = 1; + } +} + +static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, + u32 pmtu, unsigned long expires) +{ + struct fnhe_hash_bucket *hash; + struct fib_nh_exception *fnhe; + struct rtable *rt; + unsigned int i; + int depth; + u32 hval = fnhe_hashfun(daddr); + + spin_lock_bh(&fnhe_lock); + + hash = rcu_dereference(nh->nh_exceptions); + if (!hash) { + hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC); + if (!hash) + goto out_unlock; + rcu_assign_pointer(nh->nh_exceptions, hash); + } + + hash += hval; + + depth = 0; + for (fnhe = rcu_dereference(hash->chain); fnhe; + fnhe = rcu_dereference(fnhe->fnhe_next)) { + if (fnhe->fnhe_daddr == daddr) + break; + depth++; + } + + if (fnhe) { + if (gw) + fnhe->fnhe_gw = gw; + if (pmtu) { + fnhe->fnhe_pmtu = pmtu; + fnhe->fnhe_expires = max(1UL, expires); + } + /* Update all cached dsts too */ + rt = rcu_dereference(fnhe->fnhe_rth_input); + if (rt) + fill_route_from_fnhe(rt, fnhe); + rt = rcu_dereference(fnhe->fnhe_rth_output); + if (rt) + fill_route_from_fnhe(rt, fnhe); + } else { + if (depth > FNHE_RECLAIM_DEPTH) + fnhe = fnhe_oldest(hash); + else { + fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); + if (!fnhe) + goto out_unlock; + + fnhe->fnhe_next = hash->chain; + rcu_assign_pointer(hash->chain, fnhe); + } + fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev)); + fnhe->fnhe_daddr = daddr; + fnhe->fnhe_gw = gw; + fnhe->fnhe_pmtu = pmtu; + fnhe->fnhe_expires = expires; + + /* Exception created; mark the cached routes for the nexthop + * stale, so anyone caching it rechecks if this exception + * applies to them. + */ + rt = rcu_dereference(nh->nh_rth_input); + if (rt) + rt->dst.obsolete = DST_OBSOLETE_KILL; + + for_each_possible_cpu(i) { + struct rtable __rcu **prt; + prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i); + rt = rcu_dereference(*prt); + if (rt) + rt->dst.obsolete = DST_OBSOLETE_KILL; + } + } + + fnhe->fnhe_stamp = jiffies; + +out_unlock: + spin_unlock_bh(&fnhe_lock); +} + +static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, + bool kill_route) +{ + __be32 new_gw = icmp_hdr(skb)->un.gateway; + __be32 old_gw = ip_hdr(skb)->saddr; + struct net_device *dev = skb->dev; + struct in_device *in_dev; + struct fib_result res; + struct neighbour *n; + struct net *net; + + switch (icmp_hdr(skb)->code & 7) { + case ICMP_REDIR_NET: + case ICMP_REDIR_NETTOS: + case ICMP_REDIR_HOST: + case ICMP_REDIR_HOSTTOS: + break; + + default: + return; + } + + if (rt->rt_gateway != old_gw) + return; + + in_dev = __in_dev_get_rcu(dev); + if (!in_dev) + return; + + net = dev_net(dev); + if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || + ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || + ipv4_is_zeronet(new_gw)) + goto reject_redirect; + + if (!IN_DEV_SHARED_MEDIA(in_dev)) { + if (!inet_addr_onlink(in_dev, new_gw, old_gw)) + goto reject_redirect; + if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) + goto reject_redirect; + } else { + if (inet_addr_type(net, new_gw) != RTN_UNICAST) + goto reject_redirect; + } + + n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw); + if (!IS_ERR(n)) { + if (!(n->nud_state & NUD_VALID)) { + neigh_event_send(n, NULL); + } else { + if (fib_lookup(net, fl4, &res) == 0) { + struct fib_nh *nh = &FIB_RES_NH(res); + + update_or_create_fnhe(nh, fl4->daddr, new_gw, + 0, 0); + } + if (kill_route) + rt->dst.obsolete = DST_OBSOLETE_KILL; + call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); + } + neigh_release(n); + } + return; + +reject_redirect: +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (IN_DEV_LOG_MARTIANS(in_dev)) { + const struct iphdr *iph = (const struct iphdr *) skb->data; + __be32 daddr = iph->daddr; + __be32 saddr = iph->saddr; + + net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" + " Advised path = %pI4 -> %pI4\n", + &old_gw, dev->name, &new_gw, + &saddr, &daddr); + } +#endif + ; +} + +static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) +{ + struct rtable *rt; + struct flowi4 fl4; + const struct iphdr *iph = (const struct iphdr *) skb->data; + int oif = skb->dev->ifindex; + u8 tos = RT_TOS(iph->tos); + u8 prot = iph->protocol; + u32 mark = skb->mark; + + rt = (struct rtable *) dst; + + __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0); + __ip_do_redirect(rt, skb, &fl4, true); +} + +static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) +{ + struct rtable *rt = (struct rtable *)dst; + struct dst_entry *ret = dst; + + if (rt) { + if (dst->obsolete > 0) { + ip_rt_put(rt); + ret = NULL; + } else if ((rt->rt_flags & RTCF_REDIRECTED) || + rt->dst.expires) { + ip_rt_put(rt); + ret = NULL; + } + } + return ret; +} + +/* + * Algorithm: + * 1. The first ip_rt_redirect_number redirects are sent + * with exponential backoff, then we stop sending them at all, + * assuming that the host ignores our redirects. + * 2. If we did not see packets requiring redirects + * during ip_rt_redirect_silence, we assume that the host + * forgot redirected route and start to send redirects again. + * + * This algorithm is much cheaper and more intelligent than dumb load limiting + * in icmp.c. + * + * NOTE. Do not forget to inhibit load limiting for redirects (redundant) + * and "frag. need" (breaks PMTU discovery) in icmp.c. + */ + +void ip_rt_send_redirect(struct sk_buff *skb) +{ + struct rtable *rt = skb_rtable(skb); + struct in_device *in_dev; + struct inet_peer *peer; + struct net *net; + int log_martians; + + rcu_read_lock(); + in_dev = __in_dev_get_rcu(rt->dst.dev); + if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { + rcu_read_unlock(); + return; + } + log_martians = IN_DEV_LOG_MARTIANS(in_dev); + rcu_read_unlock(); + + net = dev_net(rt->dst.dev); + peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); + if (!peer) { + icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, + rt_nexthop(rt, ip_hdr(skb)->daddr)); + return; + } + + /* No redirected packets during ip_rt_redirect_silence; + * reset the algorithm. + */ + if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) + peer->rate_tokens = 0; + + /* Too many ignored redirects; do not send anything + * set dst.rate_last to the last seen redirected packet. + */ + if (peer->rate_tokens >= ip_rt_redirect_number) { + peer->rate_last = jiffies; + goto out_put_peer; + } + + /* Check for load limit; set rate_last to the latest sent + * redirect. + */ + if (peer->rate_tokens == 0 || + time_after(jiffies, + (peer->rate_last + + (ip_rt_redirect_load << peer->rate_tokens)))) { + __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); + + icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); + peer->rate_last = jiffies; + ++peer->rate_tokens; +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (log_martians && + peer->rate_tokens == ip_rt_redirect_number) + net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", + &ip_hdr(skb)->saddr, inet_iif(skb), + &ip_hdr(skb)->daddr, &gw); +#endif + } +out_put_peer: + inet_putpeer(peer); +} + +static int ip_error(struct sk_buff *skb) +{ + struct in_device *in_dev = __in_dev_get_rcu(skb->dev); + struct rtable *rt = skb_rtable(skb); + struct inet_peer *peer; + unsigned long now; + struct net *net; + bool send; + int code; + + /* IP on this device is disabled. */ + if (!in_dev) + goto out; + + net = dev_net(rt->dst.dev); + if (!IN_DEV_FORWARD(in_dev)) { + switch (rt->dst.error) { + case EHOSTUNREACH: + IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS); + break; + + case ENETUNREACH: + IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); + break; + } + goto out; + } + + switch (rt->dst.error) { + case EINVAL: + default: + goto out; + case EHOSTUNREACH: + code = ICMP_HOST_UNREACH; + break; + case ENETUNREACH: + code = ICMP_NET_UNREACH; + IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); + break; + case EACCES: + code = ICMP_PKT_FILTERED; + break; + } + + peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); + + send = true; + if (peer) { + now = jiffies; + peer->rate_tokens += now - peer->rate_last; + if (peer->rate_tokens > ip_rt_error_burst) + peer->rate_tokens = ip_rt_error_burst; + peer->rate_last = now; + if (peer->rate_tokens >= ip_rt_error_cost) + peer->rate_tokens -= ip_rt_error_cost; + else + send = false; + inet_putpeer(peer); + } + if (send) + icmp_send(skb, ICMP_DEST_UNREACH, code, 0); + +out: kfree_skb(skb); + return 0; +} + +static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) +{ + struct dst_entry *dst = &rt->dst; + struct fib_result res; + + if (dst_metric_locked(dst, RTAX_MTU)) + return; + + if (ipv4_mtu(dst) < mtu) + return; + + if (mtu < ip_rt_min_pmtu) + mtu = ip_rt_min_pmtu; + + if (rt->rt_pmtu == mtu && + time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) + return; + + rcu_read_lock(); + if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) { + struct fib_nh *nh = &FIB_RES_NH(res); + + update_or_create_fnhe(nh, fl4->daddr, 0, mtu, + jiffies + ip_rt_mtu_expires); + } + rcu_read_unlock(); +} + +static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu) +{ + struct rtable *rt = (struct rtable *) dst; + struct flowi4 fl4; + + ip_rt_build_flow_key(&fl4, sk, skb); + __ip_rt_update_pmtu(rt, &fl4, mtu); +} + +void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, + int oif, u32 mark, u8 protocol, int flow_flags) +{ + const struct iphdr *iph = (const struct iphdr *) skb->data; + struct flowi4 fl4; + struct rtable *rt; + + if (!mark) + mark = IP4_REPLY_MARK(net, skb->mark); + + __build_flow_key(&fl4, NULL, iph, oif, + RT_TOS(iph->tos), protocol, mark, flow_flags); + rt = __ip_route_output_key(net, &fl4); + if (!IS_ERR(rt)) { + __ip_rt_update_pmtu(rt, &fl4, mtu); + ip_rt_put(rt); + } +} +EXPORT_SYMBOL_GPL(ipv4_update_pmtu); + +static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) +{ + const struct iphdr *iph = (const struct iphdr *) skb->data; + struct flowi4 fl4; + struct rtable *rt; + + __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); + + if (!fl4.flowi4_mark) + fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); + + rt = __ip_route_output_key(sock_net(sk), &fl4); + if (!IS_ERR(rt)) { + __ip_rt_update_pmtu(rt, &fl4, mtu); + ip_rt_put(rt); + } +} + +void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) +{ + const struct iphdr *iph = (const struct iphdr *) skb->data; + struct flowi4 fl4; + struct rtable *rt; + struct dst_entry *odst = NULL; + bool new = false; + + bh_lock_sock(sk); + + if (!ip_sk_accept_pmtu(sk)) + goto out; + + odst = sk_dst_get(sk); + + if (sock_owned_by_user(sk) || !odst) { + __ipv4_sk_update_pmtu(skb, sk, mtu); + goto out; + } + + __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); + + rt = (struct rtable *)odst; + if (odst->obsolete && !odst->ops->check(odst, 0)) { + rt = ip_route_output_flow(sock_net(sk), &fl4, sk); + if (IS_ERR(rt)) + goto out; + + new = true; + } + + __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu); + + if (!dst_check(&rt->dst, 0)) { + if (new) + dst_release(&rt->dst); + + rt = ip_route_output_flow(sock_net(sk), &fl4, sk); + if (IS_ERR(rt)) + goto out; + + new = true; + } + + if (new) + sk_dst_set(sk, &rt->dst); + +out: + bh_unlock_sock(sk); + dst_release(odst); +} +EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); + +void ipv4_redirect(struct sk_buff *skb, struct net *net, + int oif, u32 mark, u8 protocol, int flow_flags) +{ + const struct iphdr *iph = (const struct iphdr *) skb->data; + struct flowi4 fl4; + struct rtable *rt; + + __build_flow_key(&fl4, NULL, iph, oif, + RT_TOS(iph->tos), protocol, mark, flow_flags); + rt = __ip_route_output_key(net, &fl4); + if (!IS_ERR(rt)) { + __ip_do_redirect(rt, skb, &fl4, false); + ip_rt_put(rt); + } +} +EXPORT_SYMBOL_GPL(ipv4_redirect); + +void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) +{ + const struct iphdr *iph = (const struct iphdr *) skb->data; + struct flowi4 fl4; + struct rtable *rt; + + __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); + rt = __ip_route_output_key(sock_net(sk), &fl4); + if (!IS_ERR(rt)) { + __ip_do_redirect(rt, skb, &fl4, false); + ip_rt_put(rt); + } +} +EXPORT_SYMBOL_GPL(ipv4_sk_redirect); + +static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) +{ + struct rtable *rt = (struct rtable *) dst; + + /* All IPV4 dsts are created with ->obsolete set to the value + * DST_OBSOLETE_FORCE_CHK which forces validation calls down + * into this function always. + * + * When a PMTU/redirect information update invalidates a route, + * this is indicated by setting obsolete to DST_OBSOLETE_KILL or + * DST_OBSOLETE_DEAD by dst_free(). + */ + if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) + return NULL; + return dst; +} + +static void ipv4_link_failure(struct sk_buff *skb) +{ + struct rtable *rt; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); + + rt = skb_rtable(skb); + if (rt) + dst_set_expires(&rt->dst, 0); +} + +static int ip_rt_bug(struct sock *sk, struct sk_buff *skb) +{ + pr_debug("%s: %pI4 -> %pI4, %s\n", + __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, + skb->dev ? skb->dev->name : "?"); + kfree_skb(skb); + WARN_ON(1); + return 0; +} + +/* + We do not cache source address of outgoing interface, + because it is used only by IP RR, TS and SRR options, + so that it out of fast path. + + BTW remember: "addr" is allowed to be not aligned + in IP options! + */ + +void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) +{ + __be32 src; + + if (rt_is_output_route(rt)) + src = ip_hdr(skb)->saddr; + else { + struct fib_result res; + struct flowi4 fl4; + struct iphdr *iph; + + iph = ip_hdr(skb); + + memset(&fl4, 0, sizeof(fl4)); + fl4.daddr = iph->daddr; + fl4.saddr = iph->saddr; + fl4.flowi4_tos = RT_TOS(iph->tos); + fl4.flowi4_oif = rt->dst.dev->ifindex; + fl4.flowi4_iif = skb->dev->ifindex; + fl4.flowi4_mark = skb->mark; + + rcu_read_lock(); + if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) + src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); + else + src = inet_select_addr(rt->dst.dev, + rt_nexthop(rt, iph->daddr), + RT_SCOPE_UNIVERSE); + rcu_read_unlock(); + } + memcpy(addr, &src, 4); +} + +#ifdef CONFIG_IP_ROUTE_CLASSID +static void set_class_tag(struct rtable *rt, u32 tag) +{ + if (!(rt->dst.tclassid & 0xFFFF)) + rt->dst.tclassid |= tag & 0xFFFF; + if (!(rt->dst.tclassid & 0xFFFF0000)) + rt->dst.tclassid |= tag & 0xFFFF0000; +} +#endif + +static unsigned int ipv4_default_advmss(const struct dst_entry *dst) +{ + unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); + + if (advmss == 0) { + advmss = max_t(unsigned int, dst->dev->mtu - 40, + ip_rt_min_advmss); + if (advmss > 65535 - 40) + advmss = 65535 - 40; + } + return advmss; +} + +static unsigned int ipv4_mtu(const struct dst_entry *dst) +{ + const struct rtable *rt = (const struct rtable *) dst; + unsigned int mtu = rt->rt_pmtu; + + if (!mtu || time_after_eq(jiffies, rt->dst.expires)) + mtu = dst_metric_raw(dst, RTAX_MTU); + + if (mtu) + return mtu; + + mtu = dst->dev->mtu; + + if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { + if (rt->rt_uses_gateway && mtu > 576) + mtu = 576; + } + + return min_t(unsigned int, mtu, IP_MAX_MTU); +} + +static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) +{ + struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); + struct fib_nh_exception *fnhe; + u32 hval; + + if (!hash) + return NULL; + + hval = fnhe_hashfun(daddr); + + for (fnhe = rcu_dereference(hash[hval].chain); fnhe; + fnhe = rcu_dereference(fnhe->fnhe_next)) { + if (fnhe->fnhe_daddr == daddr) + return fnhe; + } + return NULL; +} + +static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, + __be32 daddr) +{ + bool ret = false; + + spin_lock_bh(&fnhe_lock); + + if (daddr == fnhe->fnhe_daddr) { + struct rtable __rcu **porig; + struct rtable *orig; + int genid = fnhe_genid(dev_net(rt->dst.dev)); + + if (rt_is_input_route(rt)) + porig = &fnhe->fnhe_rth_input; + else + porig = &fnhe->fnhe_rth_output; + orig = rcu_dereference(*porig); + + if (fnhe->fnhe_genid != genid) { + fnhe->fnhe_genid = genid; + fnhe->fnhe_gw = 0; + fnhe->fnhe_pmtu = 0; + fnhe->fnhe_expires = 0; + fnhe_flush_routes(fnhe); + orig = NULL; + } + fill_route_from_fnhe(rt, fnhe); + if (!rt->rt_gateway) + rt->rt_gateway = daddr; + + if (!(rt->dst.flags & DST_NOCACHE)) { + rcu_assign_pointer(*porig, rt); + if (orig) + rt_free(orig); + ret = true; + } + + fnhe->fnhe_stamp = jiffies; + } + spin_unlock_bh(&fnhe_lock); + + return ret; +} + +static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) +{ + struct rtable *orig, *prev, **p; + bool ret = true; + + if (rt_is_input_route(rt)) { + p = (struct rtable **)&nh->nh_rth_input; + } else { + p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); + } + orig = *p; + + prev = cmpxchg(p, orig, rt); + if (prev == orig) { + if (orig) + rt_free(orig); + } else + ret = false; + + return ret; +} + +struct uncached_list { + spinlock_t lock; + struct list_head head; +}; + +static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); + +static void rt_add_uncached_list(struct rtable *rt) +{ + struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); + + rt->rt_uncached_list = ul; + + spin_lock_bh(&ul->lock); + list_add_tail(&rt->rt_uncached, &ul->head); + spin_unlock_bh(&ul->lock); +} + +static void ipv4_dst_destroy(struct dst_entry *dst) +{ + struct rtable *rt = (struct rtable *) dst; + + if (!list_empty(&rt->rt_uncached)) { + struct uncached_list *ul = rt->rt_uncached_list; + + spin_lock_bh(&ul->lock); + list_del(&rt->rt_uncached); + spin_unlock_bh(&ul->lock); + } +} + +void rt_flush_dev(struct net_device *dev) +{ + struct net *net = dev_net(dev); + struct rtable *rt; + int cpu; + + for_each_possible_cpu(cpu) { + struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); + + spin_lock_bh(&ul->lock); + list_for_each_entry(rt, &ul->head, rt_uncached) { + if (rt->dst.dev != dev) + continue; + rt->dst.dev = net->loopback_dev; + dev_hold(rt->dst.dev); + dev_put(dev); + } + spin_unlock_bh(&ul->lock); + } +} + +static bool rt_cache_valid(const struct rtable *rt) +{ + return rt && + rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && + !rt_is_expired(rt); +} + +static void rt_set_nexthop(struct rtable *rt, __be32 daddr, + const struct fib_result *res, + struct fib_nh_exception *fnhe, + struct fib_info *fi, u16 type, u32 itag) +{ + bool cached = false; + + if (fi) { + struct fib_nh *nh = &FIB_RES_NH(*res); + + if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { + rt->rt_gateway = nh->nh_gw; + rt->rt_uses_gateway = 1; + } + dst_init_metrics(&rt->dst, fi->fib_metrics, true); +#ifdef CONFIG_IP_ROUTE_CLASSID + rt->dst.tclassid = nh->nh_tclassid; +#endif + if (unlikely(fnhe)) + cached = rt_bind_exception(rt, fnhe, daddr); + else if (!(rt->dst.flags & DST_NOCACHE)) + cached = rt_cache_route(nh, rt); + if (unlikely(!cached)) { + /* Routes we intend to cache in nexthop exception or + * FIB nexthop have the DST_NOCACHE bit clear. + * However, if we are unsuccessful at storing this + * route into the cache we really need to set it. + */ + rt->dst.flags |= DST_NOCACHE; + if (!rt->rt_gateway) + rt->rt_gateway = daddr; + rt_add_uncached_list(rt); + } + } else + rt_add_uncached_list(rt); + +#ifdef CONFIG_IP_ROUTE_CLASSID +#ifdef CONFIG_IP_MULTIPLE_TABLES + set_class_tag(rt, res->tclassid); +#endif + set_class_tag(rt, itag); +#endif +} + +static struct rtable *rt_dst_alloc(struct net_device *dev, + bool nopolicy, bool noxfrm, bool will_cache) +{ + return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, + (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | + (nopolicy ? DST_NOPOLICY : 0) | + (noxfrm ? DST_NOXFRM : 0)); +} + +/* called in rcu_read_lock() section */ +static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev, int our) +{ + struct rtable *rth; + struct in_device *in_dev = __in_dev_get_rcu(dev); + u32 itag = 0; + int err; + + /* Primary sanity checks. */ + + if (!in_dev) + return -EINVAL; + + if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || + skb->protocol != htons(ETH_P_IP)) + goto e_inval; + + if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) + if (ipv4_is_loopback(saddr)) + goto e_inval; + + if (ipv4_is_zeronet(saddr)) { + if (!ipv4_is_local_multicast(daddr)) + goto e_inval; + } else { + err = fib_validate_source(skb, saddr, 0, tos, 0, dev, + in_dev, &itag); + if (err < 0) + goto e_err; + } + rth = rt_dst_alloc(dev_net(dev)->loopback_dev, + IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); + if (!rth) + goto e_nobufs; + +#ifdef CONFIG_IP_ROUTE_CLASSID + rth->dst.tclassid = itag; +#endif + rth->dst.output = ip_rt_bug; + + rth->rt_genid = rt_genid_ipv4(dev_net(dev)); + rth->rt_flags = RTCF_MULTICAST; + rth->rt_type = RTN_MULTICAST; + rth->rt_is_input= 1; + rth->rt_iif = 0; + rth->rt_pmtu = 0; + rth->rt_gateway = 0; + rth->rt_uses_gateway = 0; + INIT_LIST_HEAD(&rth->rt_uncached); + if (our) { + rth->dst.input= ip_local_deliver; + rth->rt_flags |= RTCF_LOCAL; + } + +#ifdef CONFIG_IP_MROUTE + if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) + rth->dst.input = ip_mr_input; +#endif + RT_CACHE_STAT_INC(in_slow_mc); + + skb_dst_set(skb, &rth->dst); + return 0; + +e_nobufs: + return -ENOBUFS; +e_inval: + return -EINVAL; +e_err: + return err; +} + + +static void ip_handle_martian_source(struct net_device *dev, + struct in_device *in_dev, + struct sk_buff *skb, + __be32 daddr, + __be32 saddr) +{ + RT_CACHE_STAT_INC(in_martian_src); +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { + /* + * RFC1812 recommendation, if source is martian, + * the only hint is MAC header. + */ + pr_warn("martian source %pI4 from %pI4, on dev %s\n", + &daddr, &saddr, dev->name); + if (dev->hard_header_len && skb_mac_header_was_set(skb)) { + print_hex_dump(KERN_WARNING, "ll header: ", + DUMP_PREFIX_OFFSET, 16, 1, + skb_mac_header(skb), + dev->hard_header_len, true); + } + } +#endif +} + +/* called in rcu_read_lock() section */ +static int __mkroute_input(struct sk_buff *skb, + const struct fib_result *res, + struct in_device *in_dev, + __be32 daddr, __be32 saddr, u32 tos) +{ + struct fib_nh_exception *fnhe; + struct rtable *rth; + int err; + struct in_device *out_dev; + unsigned int flags = 0; + bool do_cache; + u32 itag = 0; + + /* get a working reference to the output device */ + out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); + if (!out_dev) { + net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); + return -EINVAL; + } + + err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), + in_dev->dev, in_dev, &itag); + if (err < 0) { + ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, + saddr); + + goto cleanup; + } + + do_cache = res->fi && !itag; + if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && + skb->protocol == htons(ETH_P_IP) && + (IN_DEV_SHARED_MEDIA(out_dev) || + inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) + IPCB(skb)->flags |= IPSKB_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; + } + } + + fnhe = find_exception(&FIB_RES_NH(*res), daddr); + if (do_cache) { + if (fnhe) + rth = rcu_dereference(fnhe->fnhe_rth_input); + else + rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); + + if (rt_cache_valid(rth)) { + skb_dst_set_noref(skb, &rth->dst); + goto out; + } + } + + rth = rt_dst_alloc(out_dev->dev, + IN_DEV_CONF_GET(in_dev, NOPOLICY), + IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); + if (!rth) { + err = -ENOBUFS; + goto cleanup; + } + + rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev)); + rth->rt_flags = flags; + rth->rt_type = res->type; + rth->rt_is_input = 1; + rth->rt_iif = 0; + rth->rt_pmtu = 0; + rth->rt_gateway = 0; + rth->rt_uses_gateway = 0; + INIT_LIST_HEAD(&rth->rt_uncached); + RT_CACHE_STAT_INC(in_slow_tot); + + rth->dst.input = ip_forward; + rth->dst.output = ip_output; + + rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag); + skb_dst_set(skb, &rth->dst); +out: + err = 0; + cleanup: + return err; +} + +static int ip_mkroute_input(struct sk_buff *skb, + struct fib_result *res, + const struct flowi4 *fl4, + struct in_device *in_dev, + __be32 daddr, __be32 saddr, u32 tos) +{ +#ifdef CONFIG_IP_ROUTE_MULTIPATH + if (res->fi && res->fi->fib_nhs > 1) + fib_select_multipath(res); +#endif + + /* create a routing cache entry */ + return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); +} + +/* + * NOTE. We drop all the packets that has local source + * addresses, because every properly looped back packet + * must have correct destination already attached by output routine. + * + * Such approach solves two big problems: + * 1. Not simplex devices are handled properly. + * 2. IP spoofing attempts are filtered with 100% of guarantee. + * called with rcu_read_lock() + */ + +static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev) +{ + struct fib_result res; + struct in_device *in_dev = __in_dev_get_rcu(dev); + struct flowi4 fl4; + unsigned int flags = 0; + u32 itag = 0; + struct rtable *rth; + int err = -EINVAL; + struct net *net = dev_net(dev); + bool do_cache; + + /* IP on this device is disabled. */ + + if (!in_dev) + goto out; + + /* Check for the most weird martians, which can be not detected + by fib_lookup. + */ + + if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) + goto martian_source; + + res.fi = NULL; + if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) + goto brd_input; + + /* Accept zero addresses only to limited broadcast; + * I even do not know to fix it or not. Waiting for complains :-) + */ + if (ipv4_is_zeronet(saddr)) + goto martian_source; + + if (ipv4_is_zeronet(daddr)) + goto martian_destination; + + /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), + * and call it once if daddr or/and saddr are loopback addresses + */ + if (ipv4_is_loopback(daddr)) { + if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) + goto martian_destination; + } else if (ipv4_is_loopback(saddr)) { + if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) + goto martian_source; + } + + /* + * Now we are ready to route packet. + */ + fl4.flowi4_oif = 0; + fl4.flowi4_iif = dev->ifindex; + fl4.flowi4_mark = skb->mark; + fl4.flowi4_tos = tos; + fl4.flowi4_scope = RT_SCOPE_UNIVERSE; + fl4.daddr = daddr; + fl4.saddr = saddr; + err = fib_lookup(net, &fl4, &res); + if (err != 0) { + if (!IN_DEV_FORWARD(in_dev)) + err = -EHOSTUNREACH; + goto no_route; + } + + if (res.type == RTN_BROADCAST) + goto brd_input; + + if (res.type == RTN_LOCAL) { + err = fib_validate_source(skb, saddr, daddr, tos, + 0, dev, in_dev, &itag); + if (err < 0) + goto martian_source_keep_err; + goto local_input; + } + + if (!IN_DEV_FORWARD(in_dev)) { + err = -EHOSTUNREACH; + goto no_route; + } + if (res.type != RTN_UNICAST) + goto martian_destination; + + err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); +out: return err; + +brd_input: + if (skb->protocol != htons(ETH_P_IP)) + goto e_inval; + + if (!ipv4_is_zeronet(saddr)) { + err = fib_validate_source(skb, saddr, 0, tos, 0, dev, + in_dev, &itag); + if (err < 0) + goto martian_source_keep_err; + } + flags |= RTCF_BROADCAST; + res.type = RTN_BROADCAST; + RT_CACHE_STAT_INC(in_brd); + +local_input: + do_cache = false; + if (res.fi) { + if (!itag) { + rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); + if (rt_cache_valid(rth)) { + skb_dst_set_noref(skb, &rth->dst); + err = 0; + goto out; + } + do_cache = true; + } + } + + rth = rt_dst_alloc(net->loopback_dev, + IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); + if (!rth) + goto e_nobufs; + + rth->dst.input= ip_local_deliver; + rth->dst.output= ip_rt_bug; +#ifdef CONFIG_IP_ROUTE_CLASSID + rth->dst.tclassid = itag; +#endif + + rth->rt_genid = rt_genid_ipv4(net); + rth->rt_flags = flags|RTCF_LOCAL; + rth->rt_type = res.type; + rth->rt_is_input = 1; + rth->rt_iif = 0; + rth->rt_pmtu = 0; + rth->rt_gateway = 0; + rth->rt_uses_gateway = 0; + INIT_LIST_HEAD(&rth->rt_uncached); + RT_CACHE_STAT_INC(in_slow_tot); + if (res.type == RTN_UNREACHABLE) { + rth->dst.input= ip_error; + rth->dst.error= -err; + rth->rt_flags &= ~RTCF_LOCAL; + } + if (do_cache) { + if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) { + rth->dst.flags |= DST_NOCACHE; + rt_add_uncached_list(rth); + } + } + skb_dst_set(skb, &rth->dst); + err = 0; + goto out; + +no_route: + RT_CACHE_STAT_INC(in_no_route); + res.type = RTN_UNREACHABLE; + res.fi = NULL; + goto local_input; + + /* + * Do not cache martian addresses: they should be logged (RFC1812) + */ +martian_destination: + RT_CACHE_STAT_INC(in_martian_dst); +#ifdef CONFIG_IP_ROUTE_VERBOSE + if (IN_DEV_LOG_MARTIANS(in_dev)) + net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", + &daddr, &saddr, dev->name); +#endif + +e_inval: + err = -EINVAL; + goto out; + +e_nobufs: + err = -ENOBUFS; + goto out; + +martian_source: + err = -EINVAL; +martian_source_keep_err: + ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); + goto out; +} + +int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev) +{ + int res; + + rcu_read_lock(); + + /* Multicast recognition logic is moved from route cache to here. + The problem was that too many Ethernet cards have broken/missing + hardware multicast filters :-( As result the host on multicasting + network acquires a lot of useless route cache entries, sort of + SDR messages from all the world. Now we try to get rid of them. + Really, provided software IP multicast filter is organized + reasonably (at least, hashed), it does not result in a slowdown + comparing with route cache reject entries. + Note, that multicast routers are not affected, because + route cache entry is created eventually. + */ + if (ipv4_is_multicast(daddr)) { + struct in_device *in_dev = __in_dev_get_rcu(dev); + + if (in_dev) { + int our = ip_check_mc_rcu(in_dev, daddr, saddr, + ip_hdr(skb)->protocol); + if (our +#ifdef CONFIG_IP_MROUTE + || + (!ipv4_is_local_multicast(daddr) && + IN_DEV_MFORWARD(in_dev)) +#endif + ) { + int res = ip_route_input_mc(skb, daddr, saddr, + tos, dev, our); + rcu_read_unlock(); + return res; + } + } + rcu_read_unlock(); + return -EINVAL; + } + res = ip_route_input_slow(skb, daddr, saddr, tos, dev); + rcu_read_unlock(); + return res; +} +EXPORT_SYMBOL(ip_route_input_noref); + +/* called with rcu_read_lock() */ +static struct rtable *__mkroute_output(const struct fib_result *res, + const struct flowi4 *fl4, int orig_oif, + struct net_device *dev_out, + unsigned int flags) +{ + struct fib_info *fi = res->fi; + struct fib_nh_exception *fnhe; + struct in_device *in_dev; + u16 type = res->type; + struct rtable *rth; + bool do_cache; + + in_dev = __in_dev_get_rcu(dev_out); + if (!in_dev) + return ERR_PTR(-EINVAL); + + if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) + if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) + return ERR_PTR(-EINVAL); + + if (ipv4_is_lbcast(fl4->daddr)) + type = RTN_BROADCAST; + else if (ipv4_is_multicast(fl4->daddr)) + type = RTN_MULTICAST; + else if (ipv4_is_zeronet(fl4->daddr)) + return ERR_PTR(-EINVAL); + + if (dev_out->flags & IFF_LOOPBACK) + flags |= RTCF_LOCAL; + + do_cache = true; + 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; + else + do_cache = false; + /* If multicast route do not exist use + * default one, but do not gateway in this case. + * Yes, it is hack. + */ + if (fi && res->prefixlen < 4) + fi = NULL; + } + + fnhe = NULL; + do_cache &= fi != NULL; + if (do_cache) { + struct rtable __rcu **prth; + struct fib_nh *nh = &FIB_RES_NH(*res); + + fnhe = find_exception(nh, fl4->daddr); + if (fnhe) + prth = &fnhe->fnhe_rth_output; + else { + if (unlikely(fl4->flowi4_flags & + FLOWI_FLAG_KNOWN_NH && + !(nh->nh_gw && + nh->nh_scope == RT_SCOPE_LINK))) { + do_cache = false; + goto add; + } + prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); + } + rth = rcu_dereference(*prth); + if (rt_cache_valid(rth)) { + dst_hold(&rth->dst); + return rth; + } + } + +add: + rth = rt_dst_alloc(dev_out, + IN_DEV_CONF_GET(in_dev, NOPOLICY), + IN_DEV_CONF_GET(in_dev, NOXFRM), + do_cache); + if (!rth) + return ERR_PTR(-ENOBUFS); + + rth->dst.output = ip_output; + + rth->rt_genid = rt_genid_ipv4(dev_net(dev_out)); + rth->rt_flags = flags; + rth->rt_type = type; + rth->rt_is_input = 0; + rth->rt_iif = orig_oif ? : 0; + rth->rt_pmtu = 0; + rth->rt_gateway = 0; + rth->rt_uses_gateway = 0; + INIT_LIST_HEAD(&rth->rt_uncached); + + RT_CACHE_STAT_INC(out_slow_tot); + + if (flags & RTCF_LOCAL) + rth->dst.input = ip_local_deliver; + if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { + if (flags & RTCF_LOCAL && + !(dev_out->flags & IFF_LOOPBACK)) { + rth->dst.output = ip_mc_output; + RT_CACHE_STAT_INC(out_slow_mc); + } +#ifdef CONFIG_IP_MROUTE + if (type == RTN_MULTICAST) { + if (IN_DEV_MFORWARD(in_dev) && + !ipv4_is_local_multicast(fl4->daddr)) { + rth->dst.input = ip_mr_input; + rth->dst.output = ip_mc_output; + } + } +#endif + } + + rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); + + return rth; +} + +/* + * Major route resolver routine. + */ + +struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) +{ + struct net_device *dev_out = NULL; + __u8 tos = RT_FL_TOS(fl4); + unsigned int flags = 0; + struct fib_result res; + struct rtable *rth; + int orig_oif; + + res.tclassid = 0; + res.fi = NULL; + res.table = NULL; + + orig_oif = fl4->flowi4_oif; + + fl4->flowi4_iif = LOOPBACK_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) + 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) + 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 = LOOPBACK_IFINDEX; + res.type = RTN_LOCAL; + flags |= RTCF_LOCAL; + goto make_route; + } + + if (fib_lookup(net, fl4, &res)) { + res.fi = NULL; + res.table = NULL; + if (fl4->flowi4_oif) { + /* Apparently, routing tables are wrong. Assume, + that the destination is on link. + + WHY? DW. + Because we are allowed to send to iface + even if it has NO routes and NO assigned + addresses. When oif is specified, routing + tables are looked up with only one purpose: + to catch if destination is gatewayed, rather than + direct. Moreover, if MSG_DONTROUTE is set, + we send packet, ignoring both routing tables + and ifaddr state. --ANK + + + We could make it even if oif is unknown, + likely IPv6, but we do not. + */ + + if (fl4->saddr == 0) + fl4->saddr = inet_select_addr(dev_out, 0, + RT_SCOPE_LINK); + res.type = RTN_UNICAST; + goto make_route; + } + rth = ERR_PTR(-ENETUNREACH); + goto out; + } + + if (res.type == RTN_LOCAL) { + if (!fl4->saddr) { + if (res.fi->fib_prefsrc) + fl4->saddr = res.fi->fib_prefsrc; + else + fl4->saddr = fl4->daddr; + } + dev_out = net->loopback_dev; + fl4->flowi4_oif = dev_out->ifindex; + flags |= RTCF_LOCAL; + goto make_route; + } + +#ifdef CONFIG_IP_ROUTE_MULTIPATH + if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) + fib_select_multipath(&res); + else +#endif + if (!res.prefixlen && + res.table->tb_num_default > 1 && + res.type == RTN_UNICAST && !fl4->flowi4_oif) + fib_select_default(&res); + + if (!fl4->saddr) + fl4->saddr = FIB_RES_PREFSRC(net, res); + + dev_out = FIB_RES_DEV(res); + fl4->flowi4_oif = dev_out->ifindex; + + +make_route: + rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); + +out: + rcu_read_unlock(); + return rth; +} +EXPORT_SYMBOL_GPL(__ip_route_output_key); + +static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) +{ + return NULL; +} + +static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) +{ + unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); + + return mtu ? : dst->dev->mtu; +} + +static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu) +{ +} + +static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb) +{ +} + +static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, + unsigned long old) +{ + return NULL; +} + +static struct dst_ops ipv4_dst_blackhole_ops = { + .family = AF_INET, + .check = ipv4_blackhole_dst_check, + .mtu = ipv4_blackhole_mtu, + .default_advmss = ipv4_default_advmss, + .update_pmtu = ipv4_rt_blackhole_update_pmtu, + .redirect = ipv4_rt_blackhole_redirect, + .cow_metrics = ipv4_rt_blackhole_cow_metrics, + .neigh_lookup = ipv4_neigh_lookup, +}; + +struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) +{ + struct rtable *ort = (struct rtable *) dst_orig; + struct rtable *rt; + + rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); + if (rt) { + struct dst_entry *new = &rt->dst; + + new->__use = 1; + new->input = dst_discard; + new->output = dst_discard_sk; + + new->dev = ort->dst.dev; + if (new->dev) + dev_hold(new->dev); + + rt->rt_is_input = ort->rt_is_input; + rt->rt_iif = ort->rt_iif; + rt->rt_pmtu = ort->rt_pmtu; + + rt->rt_genid = rt_genid_ipv4(net); + rt->rt_flags = ort->rt_flags; + rt->rt_type = ort->rt_type; + rt->rt_gateway = ort->rt_gateway; + rt->rt_uses_gateway = ort->rt_uses_gateway; + + INIT_LIST_HEAD(&rt->rt_uncached); + + dst_free(new); + } + + dst_release(dst_orig); + + return rt ? &rt->dst : ERR_PTR(-ENOMEM); +} + +struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, + struct sock *sk) +{ + struct rtable *rt = __ip_route_output_key(net, flp4); + + if (IS_ERR(rt)) + return rt; + + if (flp4->flowi4_proto) + rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, + flowi4_to_flowi(flp4), + sk, 0); + + return rt; +} +EXPORT_SYMBOL_GPL(ip_route_output_flow); + +static int rt_fill_info(struct net *net, __be32 dst, __be32 src, + struct flowi4 *fl4, struct sk_buff *skb, u32 portid, + u32 seq, int event, int nowait, unsigned int flags) +{ + struct rtable *rt = skb_rtable(skb); + struct rtmsg *r; + struct nlmsghdr *nlh; + unsigned long expires = 0; + u32 error; + u32 metrics[RTAX_MAX]; + + nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); + if (!nlh) + return -EMSGSIZE; + + r = nlmsg_data(nlh); + r->rtm_family = AF_INET; + r->rtm_dst_len = 32; + r->rtm_src_len = 0; + r->rtm_tos = fl4->flowi4_tos; + r->rtm_table = RT_TABLE_MAIN; + if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) + goto nla_put_failure; + r->rtm_type = rt->rt_type; + r->rtm_scope = RT_SCOPE_UNIVERSE; + r->rtm_protocol = RTPROT_UNSPEC; + r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; + if (rt->rt_flags & RTCF_NOTIFY) + r->rtm_flags |= RTM_F_NOTIFY; + if (IPCB(skb)->flags & IPSKB_DOREDIRECT) + r->rtm_flags |= RTCF_DOREDIRECT; + + if (nla_put_in_addr(skb, RTA_DST, dst)) + goto nla_put_failure; + if (src) { + r->rtm_src_len = 32; + if (nla_put_in_addr(skb, RTA_SRC, src)) + goto nla_put_failure; + } + if (rt->dst.dev && + nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) + goto nla_put_failure; +#ifdef CONFIG_IP_ROUTE_CLASSID + if (rt->dst.tclassid && + nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) + goto nla_put_failure; +#endif + if (!rt_is_input_route(rt) && + fl4->saddr != src) { + if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) + goto nla_put_failure; + } + if (rt->rt_uses_gateway && + nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) + goto nla_put_failure; + + expires = rt->dst.expires; + if (expires) { + unsigned long now = jiffies; + + if (time_before(now, expires)) + expires -= now; + else + expires = 0; + } + + memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); + if (rt->rt_pmtu && expires) + metrics[RTAX_MTU - 1] = rt->rt_pmtu; + if (rtnetlink_put_metrics(skb, metrics) < 0) + goto nla_put_failure; + + if (fl4->flowi4_mark && + nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) + goto nla_put_failure; + + error = rt->dst.error; + + if (rt_is_input_route(rt)) { +#ifdef CONFIG_IP_MROUTE + if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && + IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { + int err = ipmr_get_route(net, skb, + fl4->saddr, fl4->daddr, + 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 + if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex)) + goto nla_put_failure; + } + + if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) + goto nla_put_failure; + + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) +{ + struct net *net = sock_net(in_skb->sk); + struct rtmsg *rtm; + struct nlattr *tb[RTA_MAX+1]; + struct rtable *rt = NULL; + struct flowi4 fl4; + __be32 dst = 0; + __be32 src = 0; + u32 iif; + int err; + int mark; + struct sk_buff *skb; + + err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); + if (err < 0) + goto errout; + + rtm = nlmsg_data(nlh); + + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + if (!skb) { + 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_in_addr(tb[RTA_SRC]) : 0; + dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; + iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; + mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; + + memset(&fl4, 0, sizeof(fl4)); + fl4.daddr = dst; + fl4.saddr = src; + fl4.flowi4_tos = rtm->rtm_tos; + fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; + fl4.flowi4_mark = mark; + + if (iif) { + struct net_device *dev; + + dev = __dev_get_by_index(net, iif); + if (!dev) { + err = -ENODEV; + goto errout_free; + } + + skb->protocol = htons(ETH_P_IP); + skb->dev = dev; + skb->mark = mark; + local_bh_disable(); + err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); + local_bh_enable(); + + rt = skb_rtable(skb); + if (err == 0 && rt->dst.error) + err = -rt->dst.error; + } else { + rt = ip_route_output_key(net, &fl4); + + err = 0; + if (IS_ERR(rt)) + err = PTR_ERR(rt); + } + + if (err) + goto errout_free; + + skb_dst_set(skb, &rt->dst); + if (rtm->rtm_flags & RTM_F_NOTIFY) + rt->rt_flags |= RTCF_NOTIFY; + + err = rt_fill_info(net, dst, src, &fl4, skb, + NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, + RTM_NEWROUTE, 0, 0); + if (err < 0) + goto errout_free; + + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); +errout: + return err; + +errout_free: + kfree_skb(skb); + goto errout; +} + +void ip_rt_multicast_event(struct in_device *in_dev) +{ + rt_cache_flush(dev_net(in_dev->dev)); +} + +#ifdef CONFIG_SYSCTL +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_gc_elasticity __read_mostly = 8; + +static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, + void __user *buffer, + size_t *lenp, loff_t *ppos) +{ + struct net *net = (struct net *)__ctl->extra1; + + if (write) { + rt_cache_flush(net); + fnhe_genid_bump(net); + return 0; + } + + return -EINVAL; +} + +static struct ctl_table ipv4_route_table[] = { + { + .procname = "gc_thresh", + .data = &ipv4_dst_ops.gc_thresh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "max_size", + .data = &ip_rt_max_size, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + /* Deprecated. Use gc_min_interval_ms */ + + .procname = "gc_min_interval", + .data = &ip_rt_gc_min_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "gc_min_interval_ms", + .data = &ip_rt_gc_min_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_ms_jiffies, + }, + { + .procname = "gc_timeout", + .data = &ip_rt_gc_timeout, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "gc_interval", + .data = &ip_rt_gc_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "redirect_load", + .data = &ip_rt_redirect_load, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "redirect_number", + .data = &ip_rt_redirect_number, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "redirect_silence", + .data = &ip_rt_redirect_silence, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "error_cost", + .data = &ip_rt_error_cost, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "error_burst", + .data = &ip_rt_error_burst, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "gc_elasticity", + .data = &ip_rt_gc_elasticity, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "mtu_expires", + .data = &ip_rt_mtu_expires, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "min_pmtu", + .data = &ip_rt_min_pmtu, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "min_adv_mss", + .data = &ip_rt_min_advmss, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static struct ctl_table ipv4_route_flush_table[] = { + { + .procname = "flush", + .maxlen = sizeof(int), + .mode = 0200, + .proc_handler = ipv4_sysctl_rtcache_flush, + }, + { }, +}; + +static __net_init int sysctl_route_net_init(struct net *net) +{ + struct ctl_table *tbl; + + tbl = ipv4_route_flush_table; + if (!net_eq(net, &init_net)) { + tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); + if (!tbl) + goto err_dup; + + /* Don't export sysctls to unprivileged users */ + if (net->user_ns != &init_user_ns) + tbl[0].procname = NULL; + } + tbl[0].extra1 = net; + + net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); + if (!net->ipv4.route_hdr) + 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) +{ + atomic_set(&net->ipv4.rt_genid, 0); + atomic_set(&net->fnhe_genid, 0); + get_random_bytes(&net->ipv4.dev_addr_genid, + sizeof(net->ipv4.dev_addr_genid)); + return 0; +} + +static __net_initdata struct pernet_operations rt_genid_ops = { + .init = rt_genid_init, +}; + +static int __net_init ipv4_inetpeer_init(struct net *net) +{ + struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); + + if (!bp) + return -ENOMEM; + inet_peer_base_init(bp); + net->ipv4.peers = bp; + return 0; +} + +static void __net_exit ipv4_inetpeer_exit(struct net *net) +{ + struct inet_peer_base *bp = net->ipv4.peers; + + net->ipv4.peers = NULL; + inetpeer_invalidate_tree(bp); + kfree(bp); +} + +static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { + .init = ipv4_inetpeer_init, + .exit = ipv4_inetpeer_exit, +}; + +#ifdef CONFIG_IP_ROUTE_CLASSID +struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; +#endif /* CONFIG_IP_ROUTE_CLASSID */ + +int __init ip_rt_init(void) +{ + int rc = 0; + int cpu; + + ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL); + if (!ip_idents) + panic("IP: failed to allocate ip_idents\n"); + + prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); + + for_each_possible_cpu(cpu) { + struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); + + INIT_LIST_HEAD(&ul->head); + spin_lock_init(&ul->lock); + } +#ifdef CONFIG_IP_ROUTE_CLASSID + ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); + if (!ip_rt_acct) + panic("IP: failed to allocate ip_rt_acct\n"); +#endif + + ipv4_dst_ops.kmem_cachep = + kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, + SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + + ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; + + if (dst_entries_init(&ipv4_dst_ops) < 0) + panic("IP: failed to allocate ipv4_dst_ops counter\n"); + + if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) + panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); + + ipv4_dst_ops.gc_thresh = ~0; + ip_rt_max_size = INT_MAX; + + devinet_init(); + ip_fib_init(); + + if (ip_rt_proc_init()) + pr_err("Unable to create route proc files\n"); +#ifdef CONFIG_XFRM + xfrm_init(); + xfrm4_init(); +#endif + rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); + +#ifdef CONFIG_SYSCTL + register_pernet_subsys(&sysctl_route_ops); +#endif + register_pernet_subsys(&rt_genid_ops); + register_pernet_subsys(&ipv4_inetpeer_ops); + return rc; +} + +#ifdef CONFIG_SYSCTL +/* + * We really need to sanitize the damn ipv4 init order, then all + * this nonsense will go away. + */ +void __init ip_static_sysctl_init(void) +{ + register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); +} +#endif |