[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/net/ipv4/route.c b/src/kernel/linux/v4.14/net/ipv4/route.c
new file mode 100644
index 0000000..6fcb12e
--- /dev/null
+++ b/src/kernel/linux/v4.14/net/ipv4/route.c
@@ -0,0 +1,3167 @@
+/*
+ * 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 <linux/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/dst_metadata.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/lwtunnel.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>
+#include <net/ip_tunnels.h>
+#include <net/l3mdev.h>
+
+#include "fib_lookup.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 u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
+static int ip_rt_min_advmss __read_mostly = 256;
+
+static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
+
+/*
+ * 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,
+ bool confirm_neigh);
+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 void ipv4_confirm_neigh(const struct dst_entry *dst, 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,
+ .confirm_neigh = ipv4_confirm_neigh,
+};
+
+#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);
+ }
+ (*pos)++;
+ 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);
+}
+
+static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
+{
+ struct net_device *dev = dst->dev;
+ const __be32 *pkey = daddr;
+ const struct rtable *rt;
+
+ rt = (const struct rtable *)dst;
+ if (rt->rt_gateway)
+ pkey = (const __be32 *)&rt->rt_gateway;
+ else if (!daddr ||
+ (rt->rt_flags &
+ (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL)))
+ return;
+
+ __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
+}
+
+#define IP_IDENTS_SZ 2048u
+
+static atomic_t *ip_idents __read_mostly;
+static u32 *ip_tstamps __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)
+{
+ u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
+ atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
+ u32 old = ACCESS_ONCE(*p_tstamp);
+ u32 now = (u32)jiffies;
+ u32 delta = 0;
+
+ if (old != now && cmpxchg(p_tstamp, old, now) == old)
+ delta = prandom_u32_max(now - old);
+
+ /* If UBSAN reports an error there, please make sure your compiler
+ * supports -fno-strict-overflow before reporting it that was a bug
+ * in UBSAN, and it has been fixed in GCC-8.
+ */
+ return atomic_add_return(segs + delta, p_id) - segs;
+}
+EXPORT_SYMBOL(ip_idents_reserve);
+
+void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
+{
+ u32 hash, id;
+
+ /* Note the following code is not safe, but this is okay. */
+ if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
+ get_random_bytes(&net->ipv4.ip_id_key,
+ sizeof(net->ipv4.ip_id_key));
+
+ hash = siphash_3u32((__force u32)iph->daddr,
+ (__force u32)iph->saddr,
+ iph->protocol,
+ &net->ipv4.ip_id_key);
+ id = ip_idents_reserve(hash, segs);
+ iph->id = htons(id);
+}
+EXPORT_SYMBOL(__ip_select_ident);
+
+static void __build_flow_key(const struct net *net, 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,
+ sock_net_uid(net, sk));
+}
+
+static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
+ const struct sock *sk)
+{
+ const struct net *net = dev_net(skb->dev);
+ 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(net, 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, sk->sk_uid);
+ 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 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);
+ dst_dev_put(&rt->dst);
+ dst_release(&rt->dst);
+ }
+ rt = rcu_dereference(fnhe->fnhe_rth_output);
+ if (rt) {
+ RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
+ dst_dev_put(&rt->dst);
+ dst_release(&rt->dst);
+ }
+}
+
+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->rt_mtu_locked = fnhe->fnhe_mtu_locked;
+ 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, bool lock, unsigned long expires)
+{
+ struct fnhe_hash_bucket *hash;
+ struct fib_nh_exception *fnhe;
+ struct rtable *rt;
+ u32 genid, hval;
+ unsigned int i;
+ int depth;
+
+ genid = fnhe_genid(dev_net(nh->nh_dev));
+ 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 (fnhe->fnhe_genid != genid)
+ fnhe->fnhe_genid = genid;
+ if (gw)
+ fnhe->fnhe_gw = gw;
+ if (pmtu) {
+ fnhe->fnhe_pmtu = pmtu;
+ fnhe->fnhe_mtu_locked = lock;
+ }
+ 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 = genid;
+ fnhe->fnhe_daddr = daddr;
+ fnhe->fnhe_gw = gw;
+ fnhe->fnhe_pmtu = pmtu;
+ fnhe->fnhe_mtu_locked = lock;
+ fnhe->fnhe_expires = max(1UL, 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.dev, new_gw);
+ if (!n)
+ n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
+ if (!IS_ERR(n)) {
+ if (!(n->nud_state & NUD_VALID)) {
+ neigh_event_send(n, NULL);
+ } else {
+ if (fib_lookup(net, fl4, &res, 0) == 0) {
+ struct fib_nh *nh = &FIB_RES_NH(res);
+
+ fib_select_path(net, &res, fl4, skb);
+ nh = &FIB_RES_NH(res);
+ update_or_create_fnhe(nh, fl4->daddr, new_gw,
+ 0, false,
+ jiffies + ip_rt_gc_timeout);
+ }
+ 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;
+ struct net *net = dev_net(skb->dev);
+ 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(net, &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;
+ int vif;
+
+ 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);
+ vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
+ rcu_read_unlock();
+
+ net = dev_net(rt->dst.dev);
+ peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 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;
+ peer->n_redirects = 0;
+ }
+
+ /* Too many ignored redirects; do not send anything
+ * set dst.rate_last to the last seen redirected packet.
+ */
+ if (peer->n_redirects >= 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->n_redirects == 0 ||
+ time_after(jiffies,
+ (peer->rate_last +
+ (ip_rt_redirect_load << peer->n_redirects)))) {
+ __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
+
+ icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
+ peer->rate_last = jiffies;
+ ++peer->n_redirects;
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+ if (log_martians &&
+ peer->n_redirects == 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(net, IPSTATS_MIB_INADDRERRORS);
+ break;
+
+ case ENETUNREACH:
+ __IP_INC_STATS(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(net, IPSTATS_MIB_INNOROUTES);
+ break;
+ case EACCES:
+ code = ICMP_PKT_FILTERED;
+ break;
+ }
+
+ peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
+ l3mdev_master_ifindex(skb->dev), 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 net *net = dev_net(dst->dev);
+ u32 old_mtu = ipv4_mtu(dst);
+ struct fib_result res;
+ bool lock = false;
+
+ if (ip_mtu_locked(dst))
+ return;
+
+ if (old_mtu < mtu)
+ return;
+
+ if (mtu < ip_rt_min_pmtu) {
+ lock = true;
+ mtu = min(old_mtu, ip_rt_min_pmtu);
+ }
+
+ if (rt->rt_pmtu == mtu && !lock &&
+ time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
+ return;
+
+ rcu_read_lock();
+ if (fib_lookup(net, fl4, &res, 0) == 0) {
+ struct fib_nh *nh;
+
+ fib_select_path(net, &res, fl4, NULL);
+ nh = &FIB_RES_NH(res);
+ update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock,
+ 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,
+ bool confirm_neigh)
+{
+ 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(net, &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(sock_net(sk), &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;
+ struct net *net = sock_net(sk);
+
+ 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(net, &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(net, &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;
+ struct net *net = sock_net(sk);
+
+ __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
+ 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_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_send_dest_unreach(struct sk_buff *skb)
+{
+ struct ip_options opt;
+ int res;
+
+ /* Recompile ip options since IPCB may not be valid anymore.
+ * Also check we have a reasonable ipv4 header.
+ */
+ if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) ||
+ ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5)
+ return;
+
+ memset(&opt, 0, sizeof(opt));
+ if (ip_hdr(skb)->ihl > 5) {
+ if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4))
+ return;
+ opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
+
+ rcu_read_lock();
+ res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL);
+ rcu_read_unlock();
+
+ if (res)
+ return;
+ }
+ __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
+}
+
+static void ipv4_link_failure(struct sk_buff *skb)
+{
+ struct rtable *rt;
+
+ ipv4_send_dest_unreach(skb);
+
+ rt = skb_rtable(skb);
+ if (rt)
+ dst_set_expires(&rt->dst, 0);
+}
+
+static int ip_rt_bug(struct net *net, 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) == 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 header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
+ unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
+ ip_rt_min_advmss);
+
+ return min(advmss, IPV4_MAX_PMTU - header_size);
+}
+
+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 = READ_ONCE(dst->dev->mtu);
+
+ if (unlikely(ip_mtu_locked(dst))) {
+ if (rt->rt_uses_gateway && mtu > 576)
+ mtu = 576;
+ }
+
+ mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
+
+ return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
+}
+
+static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
+{
+ struct fnhe_hash_bucket *hash;
+ struct fib_nh_exception *fnhe, __rcu **fnhe_p;
+ u32 hval = fnhe_hashfun(daddr);
+
+ spin_lock_bh(&fnhe_lock);
+
+ hash = rcu_dereference_protected(nh->nh_exceptions,
+ lockdep_is_held(&fnhe_lock));
+ hash += hval;
+
+ fnhe_p = &hash->chain;
+ fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
+ while (fnhe) {
+ if (fnhe->fnhe_daddr == daddr) {
+ rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
+ fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
+ /* set fnhe_daddr to 0 to ensure it won't bind with
+ * new dsts in rt_bind_exception().
+ */
+ fnhe->fnhe_daddr = 0;
+ fnhe_flush_routes(fnhe);
+ kfree_rcu(fnhe, rcu);
+ break;
+ }
+ fnhe_p = &fnhe->fnhe_next;
+ fnhe = rcu_dereference_protected(fnhe->fnhe_next,
+ lockdep_is_held(&fnhe_lock));
+ }
+
+ spin_unlock_bh(&fnhe_lock);
+}
+
+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) {
+ if (fnhe->fnhe_expires &&
+ time_after(jiffies, fnhe->fnhe_expires)) {
+ ip_del_fnhe(nh, daddr);
+ break;
+ }
+ return fnhe;
+ }
+ }
+ return NULL;
+}
+
+static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
+ __be32 daddr, const bool do_cache)
+{
+ 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 (do_cache) {
+ dst_hold(&rt->dst);
+ rcu_assign_pointer(*porig, rt);
+ if (orig) {
+ dst_dev_put(&orig->dst);
+ dst_release(&orig->dst);
+ }
+ 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;
+
+ /* hold dst before doing cmpxchg() to avoid race condition
+ * on this dst
+ */
+ dst_hold(&rt->dst);
+ prev = cmpxchg(p, orig, rt);
+ if (prev == orig) {
+ if (orig) {
+ dst_dev_put(&orig->dst);
+ dst_release(&orig->dst);
+ }
+ } else {
+ dst_release(&rt->dst);
+ 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 dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
+ struct rtable *rt = (struct rtable *) dst;
+
+ if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
+ kfree(p);
+
+ 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,
+ const bool do_cache)
+{
+ 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->metrics, true);
+ if (fi->fib_metrics != &dst_default_metrics) {
+ rt->dst._metrics |= DST_METRICS_REFCOUNTED;
+ refcount_inc(&fi->fib_metrics->refcnt);
+ }
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ rt->dst.tclassid = nh->nh_tclassid;
+#endif
+ rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
+ if (unlikely(fnhe))
+ cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
+ else if (do_cache)
+ 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.
+ */
+ 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
+}
+
+struct rtable *rt_dst_alloc(struct net_device *dev,
+ unsigned int flags, u16 type,
+ bool nopolicy, bool noxfrm, bool will_cache)
+{
+ struct rtable *rt;
+
+ rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
+ (will_cache ? 0 : DST_HOST) |
+ (nopolicy ? DST_NOPOLICY : 0) |
+ (noxfrm ? DST_NOXFRM : 0));
+
+ if (rt) {
+ rt->rt_genid = rt_genid_ipv4(dev_net(dev));
+ rt->rt_flags = flags;
+ rt->rt_type = type;
+ rt->rt_is_input = 0;
+ rt->rt_iif = 0;
+ rt->rt_pmtu = 0;
+ rt->rt_mtu_locked = 0;
+ rt->rt_gateway = 0;
+ rt->rt_uses_gateway = 0;
+ rt->rt_table_id = 0;
+ INIT_LIST_HEAD(&rt->rt_uncached);
+
+ rt->dst.output = ip_output;
+ if (flags & RTCF_LOCAL)
+ rt->dst.input = ip_local_deliver;
+ }
+
+ return rt;
+}
+EXPORT_SYMBOL(rt_dst_alloc);
+
+/* called in rcu_read_lock() section */
+int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ u8 tos, struct net_device *dev,
+ struct in_device *in_dev, u32 *itag)
+{
+ 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))
+ return -EINVAL;
+
+ if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
+ return -EINVAL;
+
+ if (ipv4_is_zeronet(saddr)) {
+ if (!ipv4_is_local_multicast(daddr))
+ return -EINVAL;
+ } else {
+ err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
+ in_dev, itag);
+ if (err < 0)
+ return err;
+ }
+ return 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 in_device *in_dev = __in_dev_get_rcu(dev);
+ unsigned int flags = RTCF_MULTICAST;
+ struct rtable *rth;
+ u32 itag = 0;
+ int err;
+
+ err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
+ if (err)
+ return err;
+
+ if (our)
+ flags |= RTCF_LOCAL;
+
+ rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
+ IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
+ if (!rth)
+ return -ENOBUFS;
+
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ rth->dst.tclassid = itag;
+#endif
+ rth->dst.output = ip_rt_bug;
+ rth->rt_is_input= 1;
+
+#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;
+}
+
+
+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
+}
+
+static void set_lwt_redirect(struct rtable *rth)
+{
+ if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
+ rth->dst.lwtstate->orig_output = rth->dst.output;
+ rth->dst.output = lwtunnel_output;
+ }
+
+ if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
+ rth->dst.lwtstate->orig_input = rth->dst.input;
+ rth->dst.input = lwtunnel_input;
+ }
+}
+
+/* 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;
+ 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, 0, res->type,
+ IN_DEV_CONF_GET(in_dev, NOPOLICY),
+ IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
+ if (!rth) {
+ err = -ENOBUFS;
+ goto cleanup;
+ }
+
+ rth->rt_is_input = 1;
+ if (res->table)
+ rth->rt_table_id = res->table->tb_id;
+ RT_CACHE_STAT_INC(in_slow_tot);
+
+ rth->dst.input = ip_forward;
+
+ rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
+ do_cache);
+ set_lwt_redirect(rth);
+ skb_dst_set(skb, &rth->dst);
+out:
+ err = 0;
+ cleanup:
+ return err;
+}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+/* To make ICMP packets follow the right flow, the multipath hash is
+ * calculated from the inner IP addresses.
+ */
+static void ip_multipath_l3_keys(const struct sk_buff *skb,
+ struct flow_keys *hash_keys)
+{
+ const struct iphdr *outer_iph = ip_hdr(skb);
+ const struct iphdr *inner_iph;
+ const struct icmphdr *icmph;
+ struct iphdr _inner_iph;
+ struct icmphdr _icmph;
+
+ hash_keys->addrs.v4addrs.src = outer_iph->saddr;
+ hash_keys->addrs.v4addrs.dst = outer_iph->daddr;
+ if (likely(outer_iph->protocol != IPPROTO_ICMP))
+ return;
+
+ if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
+ return;
+
+ icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
+ &_icmph);
+ if (!icmph)
+ return;
+
+ if (icmph->type != ICMP_DEST_UNREACH &&
+ icmph->type != ICMP_REDIRECT &&
+ icmph->type != ICMP_TIME_EXCEEDED &&
+ icmph->type != ICMP_PARAMETERPROB)
+ return;
+
+ inner_iph = skb_header_pointer(skb,
+ outer_iph->ihl * 4 + sizeof(_icmph),
+ sizeof(_inner_iph), &_inner_iph);
+ if (!inner_iph)
+ return;
+ hash_keys->addrs.v4addrs.src = inner_iph->saddr;
+ hash_keys->addrs.v4addrs.dst = inner_iph->daddr;
+}
+
+/* if skb is set it will be used and fl4 can be NULL */
+int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
+ const struct sk_buff *skb)
+{
+ struct net *net = fi->fib_net;
+ struct flow_keys hash_keys;
+ u32 mhash;
+
+ switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
+ case 0:
+ memset(&hash_keys, 0, sizeof(hash_keys));
+ hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
+ if (skb) {
+ ip_multipath_l3_keys(skb, &hash_keys);
+ } else {
+ hash_keys.addrs.v4addrs.src = fl4->saddr;
+ hash_keys.addrs.v4addrs.dst = fl4->daddr;
+ }
+ break;
+ case 1:
+ /* skb is currently provided only when forwarding */
+ if (skb) {
+ unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
+ struct flow_keys keys;
+
+ /* short-circuit if we already have L4 hash present */
+ if (skb->l4_hash)
+ return skb_get_hash_raw(skb) >> 1;
+ memset(&hash_keys, 0, sizeof(hash_keys));
+ skb_flow_dissect_flow_keys(skb, &keys, flag);
+
+ hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
+ hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
+ hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
+ hash_keys.ports.src = keys.ports.src;
+ hash_keys.ports.dst = keys.ports.dst;
+ hash_keys.basic.ip_proto = keys.basic.ip_proto;
+ } else {
+ memset(&hash_keys, 0, sizeof(hash_keys));
+ hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
+ hash_keys.addrs.v4addrs.src = fl4->saddr;
+ hash_keys.addrs.v4addrs.dst = fl4->daddr;
+ hash_keys.ports.src = fl4->fl4_sport;
+ hash_keys.ports.dst = fl4->fl4_dport;
+ hash_keys.basic.ip_proto = fl4->flowi4_proto;
+ }
+ break;
+ }
+ mhash = flow_hash_from_keys(&hash_keys);
+
+ return mhash >> 1;
+}
+EXPORT_SYMBOL_GPL(fib_multipath_hash);
+#endif /* CONFIG_IP_ROUTE_MULTIPATH */
+
+static int ip_mkroute_input(struct sk_buff *skb,
+ struct fib_result *res,
+ struct in_device *in_dev,
+ __be32 daddr, __be32 saddr, u32 tos)
+{
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (res->fi && res->fi->fib_nhs > 1) {
+ int h = fib_multipath_hash(res->fi, NULL, skb);
+
+ fib_select_multipath(res, h);
+ }
+#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 ip_tunnel_info *tun_info;
+ 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.
+ */
+
+ tun_info = skb_tunnel_info(skb);
+ if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
+ fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
+ else
+ fl4.flowi4_tun_key.tun_id = 0;
+ skb_dst_drop(skb);
+
+ if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
+ goto martian_source;
+
+ res->fi = NULL;
+ res->table = 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.flowi4_flags = 0;
+ fl4.daddr = daddr;
+ fl4.saddr = saddr;
+ fl4.flowi4_uid = sock_net_uid(net, NULL);
+ err = fib_lookup(net, &fl4, res, 0);
+ 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;
+ 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, 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;
+ }
+ 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(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
+ flags | RTCF_LOCAL, res->type,
+ IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
+ if (!rth)
+ goto e_nobufs;
+
+ rth->dst.output= ip_rt_bug;
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ rth->dst.tclassid = itag;
+#endif
+ rth->rt_is_input = 1;
+ if (res->table)
+ rth->rt_table_id = res->table->tb_id;
+
+ 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) {
+ struct fib_nh *nh = &FIB_RES_NH(*res);
+
+ rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
+ if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
+ WARN_ON(rth->dst.input == lwtunnel_input);
+ rth->dst.lwtstate->orig_input = rth->dst.input;
+ rth->dst.input = lwtunnel_input;
+ }
+
+ if (unlikely(!rt_cache_route(nh, rth)))
+ 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;
+ res->table = 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:
+ 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)
+{
+ struct fib_result res;
+ int err;
+
+ tos &= IPTOS_RT_MASK;
+ rcu_read_lock();
+ err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
+ rcu_read_unlock();
+
+ return err;
+}
+EXPORT_SYMBOL(ip_route_input_noref);
+
+/* called with rcu_read_lock held */
+int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ u8 tos, struct net_device *dev, struct fib_result *res)
+{
+ /* 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);
+ int our = 0;
+ int err = -EINVAL;
+
+ if (!in_dev)
+ return err;
+ our = ip_check_mc_rcu(in_dev, daddr, saddr,
+ ip_hdr(skb)->protocol);
+
+ /* check l3 master if no match yet */
+ if (!our && netif_is_l3_slave(dev)) {
+ struct in_device *l3_in_dev;
+
+ l3_in_dev = __in_dev_get_rcu(skb->dev);
+ if (l3_in_dev)
+ our = ip_check_mc_rcu(l3_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
+ ) {
+ err = ip_route_input_mc(skb, daddr, saddr,
+ tos, dev, our);
+ }
+ return err;
+ }
+
+ return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
+}
+
+/* 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) &&
+ !netif_is_l3_master(dev_out))
+ 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;
+ } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
+ (orig_oif != dev_out->ifindex)) {
+ /* For local routes that require a particular output interface
+ * we do not want to cache the result. Caching the result
+ * causes incorrect behaviour when there are multiple source
+ * addresses on the interface, the end result being that if the
+ * intended recipient is waiting on that interface for the
+ * packet he won't receive it because it will be delivered on
+ * the loopback interface and the IP_PKTINFO ipi_ifindex will
+ * be set to the loopback interface as well.
+ */
+ do_cache = false;
+ }
+
+ fnhe = NULL;
+ do_cache &= fi != NULL;
+ if (fi) {
+ struct rtable __rcu **prth;
+ struct fib_nh *nh = &FIB_RES_NH(*res);
+
+ fnhe = find_exception(nh, fl4->daddr);
+ if (!do_cache)
+ goto add;
+ 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_safe(&rth->dst))
+ return rth;
+ }
+
+add:
+ rth = rt_dst_alloc(dev_out, flags, type,
+ IN_DEV_CONF_GET(in_dev, NOPOLICY),
+ IN_DEV_CONF_GET(in_dev, NOXFRM),
+ do_cache);
+ if (!rth)
+ return ERR_PTR(-ENOBUFS);
+
+ rth->rt_iif = orig_oif;
+ if (res->table)
+ rth->rt_table_id = res->table->tb_id;
+
+ RT_CACHE_STAT_INC(out_slow_tot);
+
+ 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, do_cache);
+ set_lwt_redirect(rth);
+
+ return rth;
+}
+
+/*
+ * Major route resolver routine.
+ */
+
+struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
+ const struct sk_buff *skb)
+{
+ __u8 tos = RT_FL_TOS(fl4);
+ struct fib_result res = {
+ .type = RTN_UNSPEC,
+ .fi = NULL,
+ .table = NULL,
+ .tclassid = 0,
+ };
+ struct rtable *rth;
+
+ 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();
+ rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
+ rcu_read_unlock();
+
+ return rth;
+}
+EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
+
+struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
+ struct fib_result *res,
+ const struct sk_buff *skb)
+{
+ struct net_device *dev_out = NULL;
+ int orig_oif = fl4->flowi4_oif;
+ unsigned int flags = 0;
+ struct rtable *rth;
+ int err;
+
+ if (fl4->saddr) {
+ if (ipv4_is_multicast(fl4->saddr) ||
+ ipv4_is_lbcast(fl4->saddr) ||
+ ipv4_is_zeronet(fl4->saddr)) {
+ rth = ERR_PTR(-EINVAL);
+ goto out;
+ }
+
+ rth = ERR_PTR(-ENETUNREACH);
+
+ /* 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) ||
+ fl4->flowi4_proto == IPPROTO_IGMP) {
+ 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;
+ }
+
+ err = fib_lookup(net, fl4, res, 0);
+ if (err) {
+ res->fi = NULL;
+ res->table = NULL;
+ if (fl4->flowi4_oif &&
+ (ipv4_is_multicast(fl4->daddr) ||
+ !netif_index_is_l3_master(net, 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(err);
+ 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;
+ }
+
+ /* L3 master device is the loopback for that domain */
+ dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
+ net->loopback_dev;
+
+ /* make sure orig_oif points to fib result device even
+ * though packet rx/tx happens over loopback or l3mdev
+ */
+ orig_oif = FIB_RES_OIF(*res);
+
+ fl4->flowi4_oif = dev_out->ifindex;
+ flags |= RTCF_LOCAL;
+ goto make_route;
+ }
+
+ fib_select_path(net, res, fl4, skb);
+
+ dev_out = FIB_RES_DEV(*res);
+
+make_route:
+ rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
+
+out:
+ return rth;
+}
+
+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,
+ bool confirm_neigh)
+{
+}
+
+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_DEAD, 0);
+ if (rt) {
+ struct dst_entry *new = &rt->dst;
+
+ new->__use = 1;
+ new->input = dst_discard;
+ new->output = dst_discard_out;
+
+ new->dev = net->loopback_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_mtu_locked = ort->rt_mtu_locked;
+
+ 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_release(dst_orig);
+
+ return rt ? &rt->dst : ERR_PTR(-ENOMEM);
+}
+
+struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
+ const 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);
+
+/* called with rcu_read_lock held */
+static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id,
+ struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
+ u32 seq)
+{
+ 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, RTM_NEWROUTE, sizeof(*r), 0);
+ 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 = table_id < 256 ? table_id : RT_TABLE_COMPAT;
+ if (nla_put_u32(skb, RTA_TABLE, table_id))
+ 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 (rt->rt_mtu_locked && expires)
+ metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
+ 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;
+
+ if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
+ nla_put_u32(skb, RTA_UID,
+ from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
+ 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, portid);
+
+ if (err <= 0) {
+ if (err == 0)
+ return 0;
+ goto nla_put_failure;
+ }
+ } 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 netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(in_skb->sk);
+ struct rtmsg *rtm;
+ struct nlattr *tb[RTA_MAX+1];
+ struct fib_result res = {};
+ struct rtable *rt = NULL;
+ struct flowi4 fl4;
+ __be32 dst = 0;
+ __be32 src = 0;
+ u32 iif;
+ int err;
+ int mark;
+ struct sk_buff *skb;
+ u32 table_id = RT_TABLE_MAIN;
+ kuid_t uid;
+
+ err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy,
+ extack);
+ 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);
+
+ 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;
+ if (tb[RTA_UID])
+ uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
+ else
+ uid = (iif ? INVALID_UID : current_uid());
+
+ /* Bugfix: need to give ip_route_input enough of an IP header to
+ * not gag.
+ */
+ ip_hdr(skb)->protocol = IPPROTO_UDP;
+ ip_hdr(skb)->saddr = src;
+ ip_hdr(skb)->daddr = dst;
+
+ skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
+
+ 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;
+ fl4.flowi4_uid = uid;
+
+ rcu_read_lock();
+
+ if (iif) {
+ struct net_device *dev;
+
+ dev = dev_get_by_index_rcu(net, iif);
+ if (!dev) {
+ err = -ENODEV;
+ goto errout_free;
+ }
+
+ skb->protocol = htons(ETH_P_IP);
+ skb->dev = dev;
+ skb->mark = mark;
+ err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
+ dev, &res);
+
+ rt = skb_rtable(skb);
+ if (err == 0 && rt->dst.error)
+ err = -rt->dst.error;
+ } else {
+ fl4.flowi4_iif = LOOPBACK_IFINDEX;
+ rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
+ err = 0;
+ if (IS_ERR(rt))
+ err = PTR_ERR(rt);
+ else
+ skb_dst_set(skb, &rt->dst);
+ }
+
+ if (err)
+ goto errout_free;
+
+ if (rtm->rtm_flags & RTM_F_NOTIFY)
+ rt->rt_flags |= RTCF_NOTIFY;
+
+ if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
+ table_id = rt->rt_table_id;
+
+ if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
+ if (!res.fi) {
+ err = fib_props[res.type].error;
+ if (!err)
+ err = -EHOSTUNREACH;
+ goto errout_free;
+ }
+ err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
+ nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
+ rt->rt_type, res.prefix, res.prefixlen,
+ fl4.flowi4_tos, res.fi, 0);
+ } else {
+ err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
+ NETLINK_CB(in_skb).portid, nlh->nlmsg_seq);
+ }
+ if (err < 0)
+ goto errout_free;
+
+ rcu_read_unlock();
+
+ err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+errout:
+ return err;
+
+errout_free:
+ rcu_read_unlock();
+ 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_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 ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
+
+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_minmax,
+ .extra1 = &ip_min_valid_pmtu,
+ },
+ {
+ .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);
+ atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
+ 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));
+
+ ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
+ if (!ip_tstamps)
+ panic("IP: failed to allocate ip_tstamps\n");
+
+ 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,
+ RTNL_FLAG_DOIT_UNLOCKED);
+
+#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