Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
new file mode 100644
index 0000000..9f91a116
--- /dev/null
+++ b/net/ipv4/route.c
@@ -0,0 +1,3177 @@
+/*
+ * INET An implementation of the TCP/IP protocol suite for the LINUX
+ * operating system. INET is implemented using the BSD Socket
+ * interface as the means of communication with the user level.
+ *
+ * ROUTE - implementation of the IP router.
+ *
+ * Version: $Id: route.c,v 1.103 2002/01/12 07:44:09 davem Exp $
+ *
+ * Authors: Ross Biro, <bir7@leland.Stanford.Edu>
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.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/rtnetlink.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/pkt_sched.h>
+#include <linux/mroute.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+#include <linux/rcupdate.h>
+#include <linux/times.h>
+#include <net/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/ip_mp_alg.h>
+#ifdef CONFIG_SYSCTL
+#include <linux/sysctl.h>
+#endif
+
+#define RT_FL_TOS(oldflp) \
+ ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
+
+#define IP_MAX_MTU 0xFFF0
+
+#define RT_GC_TIMEOUT (300*HZ)
+
+static int ip_rt_min_delay = 2 * HZ;
+static int ip_rt_max_delay = 10 * HZ;
+static int ip_rt_max_size;
+static int ip_rt_gc_timeout = RT_GC_TIMEOUT;
+static int ip_rt_gc_interval = 60 * HZ;
+static int ip_rt_gc_min_interval = HZ / 2;
+static int ip_rt_redirect_number = 9;
+static int ip_rt_redirect_load = HZ / 50;
+static int ip_rt_redirect_silence = ((HZ / 50) << (9 + 1));
+static int ip_rt_error_cost = HZ;
+static int ip_rt_error_burst = 5 * HZ;
+static int ip_rt_gc_elasticity = 8;
+static int ip_rt_mtu_expires = 10 * 60 * HZ;
+static int ip_rt_min_pmtu = 512 + 20 + 20;
+static int ip_rt_min_advmss = 256;
+static int ip_rt_secret_interval = 10 * 60 * HZ;
+static unsigned long rt_deadline;
+
+#define RTprint(a...) printk(KERN_DEBUG a)
+
+static struct timer_list rt_flush_timer;
+static struct timer_list rt_periodic_timer;
+static struct timer_list rt_secret_timer;
+
+/*
+ * Interface to generic destination cache.
+ */
+
+static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
+static void ipv4_dst_destroy(struct dst_entry *dst);
+static void ipv4_dst_ifdown(struct dst_entry *dst,
+ struct net_device *dev, int how);
+static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
+static void ipv4_link_failure(struct sk_buff *skb);
+static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
+static int rt_garbage_collect(void);
+
+
+static struct dst_ops ipv4_dst_ops = {
+ .family = AF_INET,
+ .protocol = __constant_htons(ETH_P_IP),
+ .gc = rt_garbage_collect,
+ .check = ipv4_dst_check,
+ .destroy = ipv4_dst_destroy,
+ .ifdown = ipv4_dst_ifdown,
+ .negative_advice = ipv4_negative_advice,
+ .link_failure = ipv4_link_failure,
+ .update_pmtu = ip_rt_update_pmtu,
+ .entry_size = sizeof(struct rtable),
+};
+
+#define ECN_OR_COST(class) TC_PRIO_##class
+
+__u8 ip_tos2prio[16] = {
+ TC_PRIO_BESTEFFORT,
+ ECN_OR_COST(FILLER),
+ TC_PRIO_BESTEFFORT,
+ ECN_OR_COST(BESTEFFORT),
+ TC_PRIO_BULK,
+ ECN_OR_COST(BULK),
+ TC_PRIO_BULK,
+ ECN_OR_COST(BULK),
+ TC_PRIO_INTERACTIVE,
+ ECN_OR_COST(INTERACTIVE),
+ TC_PRIO_INTERACTIVE,
+ ECN_OR_COST(INTERACTIVE),
+ TC_PRIO_INTERACTIVE_BULK,
+ ECN_OR_COST(INTERACTIVE_BULK),
+ TC_PRIO_INTERACTIVE_BULK,
+ ECN_OR_COST(INTERACTIVE_BULK)
+};
+
+
+/*
+ * Route cache.
+ */
+
+/* The locking scheme is rather straight forward:
+ *
+ * 1) Read-Copy Update protects the buckets of the central route hash.
+ * 2) Only writers remove entries, and they hold the lock
+ * as they look at rtable reference counts.
+ * 3) Only readers acquire references to rtable entries,
+ * they do so with atomic increments and with the
+ * lock held.
+ */
+
+struct rt_hash_bucket {
+ struct rtable *chain;
+ spinlock_t lock;
+} __attribute__((__aligned__(8)));
+
+static struct rt_hash_bucket *rt_hash_table;
+static unsigned rt_hash_mask;
+static int rt_hash_log;
+static unsigned int rt_hash_rnd;
+
+struct rt_cache_stat *rt_cache_stat;
+
+static int rt_intern_hash(unsigned hash, struct rtable *rth,
+ struct rtable **res);
+
+static unsigned int rt_hash_code(u32 daddr, u32 saddr, u8 tos)
+{
+ return (jhash_3words(daddr, saddr, (u32) tos, rt_hash_rnd)
+ & rt_hash_mask);
+}
+
+#ifdef CONFIG_PROC_FS
+struct rt_cache_iter_state {
+ int bucket;
+};
+
+static struct rtable *rt_cache_get_first(struct seq_file *seq)
+{
+ struct rtable *r = NULL;
+ struct rt_cache_iter_state *st = seq->private;
+
+ for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
+ rcu_read_lock_bh();
+ r = rt_hash_table[st->bucket].chain;
+ if (r)
+ break;
+ rcu_read_unlock_bh();
+ }
+ return r;
+}
+
+static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r)
+{
+ struct rt_cache_iter_state *st = rcu_dereference(seq->private);
+
+ r = r->u.rt_next;
+ while (!r) {
+ rcu_read_unlock_bh();
+ if (--st->bucket < 0)
+ break;
+ rcu_read_lock_bh();
+ r = rt_hash_table[st->bucket].chain;
+ }
+ return r;
+}
+
+static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
+{
+ struct rtable *r = rt_cache_get_first(seq);
+
+ if (r)
+ while (pos && (r = rt_cache_get_next(seq, r)))
+ --pos;
+ return pos ? NULL : r;
+}
+
+static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ return *pos ? rt_cache_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct rtable *r = NULL;
+
+ if (v == SEQ_START_TOKEN)
+ r = rt_cache_get_first(seq);
+ else
+ r = rt_cache_get_next(seq, v);
+ ++*pos;
+ return r;
+}
+
+static void rt_cache_seq_stop(struct seq_file *seq, void *v)
+{
+ if (v && v != SEQ_START_TOKEN)
+ rcu_read_unlock_bh();
+}
+
+static int rt_cache_seq_show(struct seq_file *seq, void *v)
+{
+ if (v == SEQ_START_TOKEN)
+ seq_printf(seq, "%-127s\n",
+ "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
+ "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
+ "HHUptod\tSpecDst");
+ else {
+ struct rtable *r = v;
+ char temp[256];
+
+ sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
+ "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",
+ r->u.dst.dev ? r->u.dst.dev->name : "*",
+ (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
+ r->rt_flags, atomic_read(&r->u.dst.__refcnt),
+ r->u.dst.__use, 0, (unsigned long)r->rt_src,
+ (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
+ (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
+ dst_metric(&r->u.dst, RTAX_WINDOW),
+ (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
+ dst_metric(&r->u.dst, RTAX_RTTVAR)),
+ r->fl.fl4_tos,
+ r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
+ r->u.dst.hh ? (r->u.dst.hh->hh_output ==
+ dev_queue_xmit) : 0,
+ r->rt_spec_dst);
+ seq_printf(seq, "%-127s\n", temp);
+ }
+ return 0;
+}
+
+static 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)
+{
+ struct seq_file *seq;
+ int rc = -ENOMEM;
+ struct rt_cache_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
+
+ if (!s)
+ goto out;
+ rc = seq_open(file, &rt_cache_seq_ops);
+ if (rc)
+ goto out_kfree;
+ seq = file->private_data;
+ seq->private = s;
+ memset(s, 0, sizeof(*s));
+out:
+ return rc;
+out_kfree:
+ kfree(s);
+ goto out;
+}
+
+static struct file_operations rt_cache_seq_fops = {
+ .owner = THIS_MODULE,
+ .open = rt_cache_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+
+static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ int cpu;
+
+ if (*pos == 0)
+ return SEQ_START_TOKEN;
+
+ for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
+ if (!cpu_possible(cpu))
+ continue;
+ *pos = cpu+1;
+ return per_cpu_ptr(rt_cache_stat, cpu);
+ }
+ return NULL;
+}
+
+static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ int cpu;
+
+ for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
+ if (!cpu_possible(cpu))
+ continue;
+ *pos = cpu+1;
+ return per_cpu_ptr(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_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
+ return 0;
+ }
+
+ seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
+ " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
+ atomic_read(&ipv4_dst_ops.entries),
+ st->in_hit,
+ st->in_slow_tot,
+ st->in_slow_mc,
+ st->in_no_route,
+ st->in_brd,
+ st->in_martian_dst,
+ st->in_martian_src,
+
+ st->out_hit,
+ st->out_slow_tot,
+ st->out_slow_mc,
+
+ st->gc_total,
+ st->gc_ignored,
+ st->gc_goal_miss,
+ st->gc_dst_overflow,
+ st->in_hlist_search,
+ st->out_hlist_search
+ );
+ return 0;
+}
+
+static 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 struct file_operations rt_cpu_seq_fops = {
+ .owner = THIS_MODULE,
+ .open = rt_cpu_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+#endif /* CONFIG_PROC_FS */
+
+static __inline__ void rt_free(struct rtable *rt)
+{
+ multipath_remove(rt);
+ call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
+}
+
+static __inline__ void rt_drop(struct rtable *rt)
+{
+ multipath_remove(rt);
+ ip_rt_put(rt);
+ call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
+}
+
+static __inline__ int rt_fast_clean(struct rtable *rth)
+{
+ /* Kill broadcast/multicast entries very aggresively, if they
+ collide in hash table with more useful entries */
+ return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
+ rth->fl.iif && rth->u.rt_next;
+}
+
+static __inline__ int rt_valuable(struct rtable *rth)
+{
+ return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
+ rth->u.dst.expires;
+}
+
+static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
+{
+ unsigned long age;
+ int ret = 0;
+
+ if (atomic_read(&rth->u.dst.__refcnt))
+ goto out;
+
+ ret = 1;
+ if (rth->u.dst.expires &&
+ time_after_eq(jiffies, rth->u.dst.expires))
+ goto out;
+
+ age = jiffies - rth->u.dst.lastuse;
+ ret = 0;
+ if ((age <= tmo1 && !rt_fast_clean(rth)) ||
+ (age <= tmo2 && rt_valuable(rth)))
+ goto out;
+ ret = 1;
+out: return ret;
+}
+
+/* Bits of score are:
+ * 31: very valuable
+ * 30: not quite useless
+ * 29..0: usage counter
+ */
+static inline u32 rt_score(struct rtable *rt)
+{
+ u32 score = jiffies - rt->u.dst.lastuse;
+
+ score = ~score & ~(3<<30);
+
+ if (rt_valuable(rt))
+ score |= (1<<31);
+
+ if (!rt->fl.iif ||
+ !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
+ score |= (1<<30);
+
+ return score;
+}
+
+static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
+{
+ return memcmp(&fl1->nl_u.ip4_u, &fl2->nl_u.ip4_u, sizeof(fl1->nl_u.ip4_u)) == 0 &&
+ fl1->oif == fl2->oif &&
+ fl1->iif == fl2->iif;
+}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+static struct rtable **rt_remove_balanced_route(struct rtable **chain_head,
+ struct rtable *expentry,
+ int *removed_count)
+{
+ int passedexpired = 0;
+ struct rtable **nextstep = NULL;
+ struct rtable **rthp = chain_head;
+ struct rtable *rth;
+
+ if (removed_count)
+ *removed_count = 0;
+
+ while ((rth = *rthp) != NULL) {
+ if (rth == expentry)
+ passedexpired = 1;
+
+ if (((*rthp)->u.dst.flags & DST_BALANCED) != 0 &&
+ compare_keys(&(*rthp)->fl, &expentry->fl)) {
+ if (*rthp == expentry) {
+ *rthp = rth->u.rt_next;
+ continue;
+ } else {
+ *rthp = rth->u.rt_next;
+ rt_free(rth);
+ if (removed_count)
+ ++(*removed_count);
+ }
+ } else {
+ if (!((*rthp)->u.dst.flags & DST_BALANCED) &&
+ passedexpired && !nextstep)
+ nextstep = &rth->u.rt_next;
+
+ rthp = &rth->u.rt_next;
+ }
+ }
+
+ rt_free(expentry);
+ if (removed_count)
+ ++(*removed_count);
+
+ return nextstep;
+}
+#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
+
+
+/* This runs via a timer and thus is always in BH context. */
+static void rt_check_expire(unsigned long dummy)
+{
+ static int rover;
+ int i = rover, t;
+ struct rtable *rth, **rthp;
+ unsigned long now = jiffies;
+
+ for (t = ip_rt_gc_interval << rt_hash_log; t >= 0;
+ t -= ip_rt_gc_timeout) {
+ unsigned long tmo = ip_rt_gc_timeout;
+
+ i = (i + 1) & rt_hash_mask;
+ rthp = &rt_hash_table[i].chain;
+
+ spin_lock(&rt_hash_table[i].lock);
+ while ((rth = *rthp) != NULL) {
+ if (rth->u.dst.expires) {
+ /* Entry is expired even if it is in use */
+ if (time_before_eq(now, rth->u.dst.expires)) {
+ tmo >>= 1;
+ rthp = &rth->u.rt_next;
+ continue;
+ }
+ } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
+ tmo >>= 1;
+ rthp = &rth->u.rt_next;
+ continue;
+ }
+
+ /* Cleanup aged off entries. */
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ /* remove all related balanced entries if necessary */
+ if (rth->u.dst.flags & DST_BALANCED) {
+ rthp = rt_remove_balanced_route(
+ &rt_hash_table[i].chain,
+ rth, NULL);
+ if (!rthp)
+ break;
+ } else {
+ *rthp = rth->u.rt_next;
+ rt_free(rth);
+ }
+#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
+ *rthp = rth->u.rt_next;
+ rt_free(rth);
+#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
+ }
+ spin_unlock(&rt_hash_table[i].lock);
+
+ /* Fallback loop breaker. */
+ if (time_after(jiffies, now))
+ break;
+ }
+ rover = i;
+ mod_timer(&rt_periodic_timer, now + ip_rt_gc_interval);
+}
+
+/* This can run from both BH and non-BH contexts, the latter
+ * in the case of a forced flush event.
+ */
+static void rt_run_flush(unsigned long dummy)
+{
+ int i;
+ struct rtable *rth, *next;
+
+ rt_deadline = 0;
+
+ get_random_bytes(&rt_hash_rnd, 4);
+
+ for (i = rt_hash_mask; i >= 0; i--) {
+ spin_lock_bh(&rt_hash_table[i].lock);
+ rth = rt_hash_table[i].chain;
+ if (rth)
+ rt_hash_table[i].chain = NULL;
+ spin_unlock_bh(&rt_hash_table[i].lock);
+
+ for (; rth; rth = next) {
+ next = rth->u.rt_next;
+ rt_free(rth);
+ }
+ }
+}
+
+static DEFINE_SPINLOCK(rt_flush_lock);
+
+void rt_cache_flush(int delay)
+{
+ unsigned long now = jiffies;
+ int user_mode = !in_softirq();
+
+ if (delay < 0)
+ delay = ip_rt_min_delay;
+
+ /* flush existing multipath state*/
+ multipath_flush();
+
+ spin_lock_bh(&rt_flush_lock);
+
+ if (del_timer(&rt_flush_timer) && delay > 0 && rt_deadline) {
+ long tmo = (long)(rt_deadline - now);
+
+ /* If flush timer is already running
+ and flush request is not immediate (delay > 0):
+
+ if deadline is not achieved, prolongate timer to "delay",
+ otherwise fire it at deadline time.
+ */
+
+ if (user_mode && tmo < ip_rt_max_delay-ip_rt_min_delay)
+ tmo = 0;
+
+ if (delay > tmo)
+ delay = tmo;
+ }
+
+ if (delay <= 0) {
+ spin_unlock_bh(&rt_flush_lock);
+ rt_run_flush(0);
+ return;
+ }
+
+ if (rt_deadline == 0)
+ rt_deadline = now + ip_rt_max_delay;
+
+ mod_timer(&rt_flush_timer, now+delay);
+ spin_unlock_bh(&rt_flush_lock);
+}
+
+static void rt_secret_rebuild(unsigned long dummy)
+{
+ unsigned long now = jiffies;
+
+ rt_cache_flush(0);
+ mod_timer(&rt_secret_timer, now + ip_rt_secret_interval);
+}
+
+/*
+ Short description of GC goals.
+
+ We want to build algorithm, which will keep routing cache
+ at some equilibrium point, when number of aged off entries
+ is kept approximately equal to newly generated ones.
+
+ Current expiration strength is variable "expire".
+ We try to adjust it dynamically, so that if networking
+ is idle expires is large enough to keep enough of warm entries,
+ and when load increases it reduces to limit cache size.
+ */
+
+static int rt_garbage_collect(void)
+{
+ static unsigned long expire = RT_GC_TIMEOUT;
+ static unsigned long last_gc;
+ static int rover;
+ static int equilibrium;
+ struct rtable *rth, **rthp;
+ unsigned long now = jiffies;
+ int goal;
+
+ /*
+ * Garbage collection is pretty expensive,
+ * do not make it too frequently.
+ */
+
+ RT_CACHE_STAT_INC(gc_total);
+
+ if (now - last_gc < ip_rt_gc_min_interval &&
+ atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
+ RT_CACHE_STAT_INC(gc_ignored);
+ goto out;
+ }
+
+ /* Calculate number of entries, which we want to expire now. */
+ goal = atomic_read(&ipv4_dst_ops.entries) -
+ (ip_rt_gc_elasticity << rt_hash_log);
+ if (goal <= 0) {
+ if (equilibrium < ipv4_dst_ops.gc_thresh)
+ equilibrium = ipv4_dst_ops.gc_thresh;
+ goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
+ if (goal > 0) {
+ equilibrium += min_t(unsigned int, goal / 2, rt_hash_mask + 1);
+ goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
+ }
+ } else {
+ /* We are in dangerous area. Try to reduce cache really
+ * aggressively.
+ */
+ goal = max_t(unsigned int, goal / 2, rt_hash_mask + 1);
+ equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
+ }
+
+ if (now - last_gc >= ip_rt_gc_min_interval)
+ last_gc = now;
+
+ if (goal <= 0) {
+ equilibrium += goal;
+ goto work_done;
+ }
+
+ do {
+ int i, k;
+
+ for (i = rt_hash_mask, k = rover; i >= 0; i--) {
+ unsigned long tmo = expire;
+
+ k = (k + 1) & rt_hash_mask;
+ rthp = &rt_hash_table[k].chain;
+ spin_lock_bh(&rt_hash_table[k].lock);
+ while ((rth = *rthp) != NULL) {
+ if (!rt_may_expire(rth, tmo, expire)) {
+ tmo >>= 1;
+ rthp = &rth->u.rt_next;
+ continue;
+ }
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ /* remove all related balanced entries
+ * if necessary
+ */
+ if (rth->u.dst.flags & DST_BALANCED) {
+ int r;
+
+ rthp = rt_remove_balanced_route(
+ &rt_hash_table[i].chain,
+ rth,
+ &r);
+ goal -= r;
+ if (!rthp)
+ break;
+ } else {
+ *rthp = rth->u.rt_next;
+ rt_free(rth);
+ goal--;
+ }
+#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
+ *rthp = rth->u.rt_next;
+ rt_free(rth);
+ goal--;
+#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
+ }
+ spin_unlock_bh(&rt_hash_table[k].lock);
+ if (goal <= 0)
+ break;
+ }
+ rover = k;
+
+ if (goal <= 0)
+ goto work_done;
+
+ /* Goal is not achieved. We stop process if:
+
+ - if expire reduced to zero. Otherwise, expire is halfed.
+ - if table is not full.
+ - if we are called from interrupt.
+ - jiffies check is just fallback/debug loop breaker.
+ We will not spin here for long time in any case.
+ */
+
+ RT_CACHE_STAT_INC(gc_goal_miss);
+
+ if (expire == 0)
+ break;
+
+ expire >>= 1;
+#if RT_CACHE_DEBUG >= 2
+ printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
+ atomic_read(&ipv4_dst_ops.entries), goal, i);
+#endif
+
+ if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
+ goto out;
+ } while (!in_softirq() && time_before_eq(jiffies, now));
+
+ if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
+ goto out;
+ if (net_ratelimit())
+ printk(KERN_WARNING "dst cache overflow\n");
+ RT_CACHE_STAT_INC(gc_dst_overflow);
+ return 1;
+
+work_done:
+ expire += ip_rt_gc_min_interval;
+ if (expire > ip_rt_gc_timeout ||
+ atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
+ expire = ip_rt_gc_timeout;
+#if RT_CACHE_DEBUG >= 2
+ printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
+ atomic_read(&ipv4_dst_ops.entries), goal, rover);
+#endif
+out: return 0;
+}
+
+static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
+{
+ struct rtable *rth, **rthp;
+ unsigned long now;
+ struct rtable *cand, **candp;
+ u32 min_score;
+ int chain_length;
+ int attempts = !in_softirq();
+
+restart:
+ chain_length = 0;
+ min_score = ~(u32)0;
+ cand = NULL;
+ candp = NULL;
+ now = jiffies;
+
+ rthp = &rt_hash_table[hash].chain;
+
+ spin_lock_bh(&rt_hash_table[hash].lock);
+ while ((rth = *rthp) != NULL) {
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ if (!(rth->u.dst.flags & DST_BALANCED) &&
+ compare_keys(&rth->fl, &rt->fl)) {
+#else
+ if (compare_keys(&rth->fl, &rt->fl)) {
+#endif
+ /* Put it first */
+ *rthp = rth->u.rt_next;
+ /*
+ * Since lookup is lockfree, the deletion
+ * must be visible to another weakly ordered CPU before
+ * the insertion at the start of the hash chain.
+ */
+ rcu_assign_pointer(rth->u.rt_next,
+ rt_hash_table[hash].chain);
+ /*
+ * Since lookup is lockfree, the update writes
+ * must be ordered for consistency on SMP.
+ */
+ rcu_assign_pointer(rt_hash_table[hash].chain, rth);
+
+ rth->u.dst.__use++;
+ dst_hold(&rth->u.dst);
+ rth->u.dst.lastuse = now;
+ spin_unlock_bh(&rt_hash_table[hash].lock);
+
+ rt_drop(rt);
+ *rp = rth;
+ return 0;
+ }
+
+ if (!atomic_read(&rth->u.dst.__refcnt)) {
+ u32 score = rt_score(rth);
+
+ if (score <= min_score) {
+ cand = rth;
+ candp = rthp;
+ min_score = score;
+ }
+ }
+
+ chain_length++;
+
+ rthp = &rth->u.rt_next;
+ }
+
+ if (cand) {
+ /* ip_rt_gc_elasticity used to be average length of chain
+ * length, when exceeded gc becomes really aggressive.
+ *
+ * The second limit is less certain. At the moment it allows
+ * only 2 entries per bucket. We will see.
+ */
+ if (chain_length > ip_rt_gc_elasticity) {
+ *candp = cand->u.rt_next;
+ rt_free(cand);
+ }
+ }
+
+ /* Try to bind route to arp only if it is output
+ route or unicast forwarding path.
+ */
+ if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
+ int err = arp_bind_neighbour(&rt->u.dst);
+ if (err) {
+ spin_unlock_bh(&rt_hash_table[hash].lock);
+
+ if (err != -ENOBUFS) {
+ rt_drop(rt);
+ return err;
+ }
+
+ /* Neighbour tables are full and nothing
+ can be released. Try to shrink route cache,
+ it is most likely it holds some neighbour records.
+ */
+ if (attempts-- > 0) {
+ int saved_elasticity = ip_rt_gc_elasticity;
+ int saved_int = ip_rt_gc_min_interval;
+ ip_rt_gc_elasticity = 1;
+ ip_rt_gc_min_interval = 0;
+ rt_garbage_collect();
+ ip_rt_gc_min_interval = saved_int;
+ ip_rt_gc_elasticity = saved_elasticity;
+ goto restart;
+ }
+
+ if (net_ratelimit())
+ printk(KERN_WARNING "Neighbour table overflow.\n");
+ rt_drop(rt);
+ return -ENOBUFS;
+ }
+ }
+
+ rt->u.rt_next = rt_hash_table[hash].chain;
+#if RT_CACHE_DEBUG >= 2
+ if (rt->u.rt_next) {
+ struct rtable *trt;
+ printk(KERN_DEBUG "rt_cache @%02x: %u.%u.%u.%u", hash,
+ NIPQUAD(rt->rt_dst));
+ for (trt = rt->u.rt_next; trt; trt = trt->u.rt_next)
+ printk(" . %u.%u.%u.%u", NIPQUAD(trt->rt_dst));
+ printk("\n");
+ }
+#endif
+ rt_hash_table[hash].chain = rt;
+ spin_unlock_bh(&rt_hash_table[hash].lock);
+ *rp = rt;
+ return 0;
+}
+
+void rt_bind_peer(struct rtable *rt, int create)
+{
+ static DEFINE_SPINLOCK(rt_peer_lock);
+ struct inet_peer *peer;
+
+ peer = inet_getpeer(rt->rt_dst, create);
+
+ spin_lock_bh(&rt_peer_lock);
+ if (rt->peer == NULL) {
+ rt->peer = peer;
+ peer = NULL;
+ }
+ spin_unlock_bh(&rt_peer_lock);
+ if (peer)
+ inet_putpeer(peer);
+}
+
+/*
+ * Peer allocation may fail only in serious out-of-memory conditions. However
+ * we still can generate some output.
+ * Random ID selection looks a bit dangerous because we have no chances to
+ * select ID being unique in a reasonable period of time.
+ * But broken packet identifier may be better than no packet at all.
+ */
+static void ip_select_fb_ident(struct iphdr *iph)
+{
+ static DEFINE_SPINLOCK(ip_fb_id_lock);
+ static u32 ip_fallback_id;
+ u32 salt;
+
+ spin_lock_bh(&ip_fb_id_lock);
+ salt = secure_ip_id(ip_fallback_id ^ iph->daddr);
+ iph->id = htons(salt & 0xFFFF);
+ ip_fallback_id = salt;
+ spin_unlock_bh(&ip_fb_id_lock);
+}
+
+void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
+{
+ struct rtable *rt = (struct rtable *) dst;
+
+ if (rt) {
+ if (rt->peer == NULL)
+ rt_bind_peer(rt, 1);
+
+ /* If peer is attached to destination, it is never detached,
+ so that we need not to grab a lock to dereference it.
+ */
+ if (rt->peer) {
+ iph->id = htons(inet_getid(rt->peer, more));
+ return;
+ }
+ } else
+ printk(KERN_DEBUG "rt_bind_peer(0) @%p\n", NET_CALLER(iph));
+
+ ip_select_fb_ident(iph);
+}
+
+static void rt_del(unsigned hash, struct rtable *rt)
+{
+ struct rtable **rthp;
+
+ spin_lock_bh(&rt_hash_table[hash].lock);
+ ip_rt_put(rt);
+ for (rthp = &rt_hash_table[hash].chain; *rthp;
+ rthp = &(*rthp)->u.rt_next)
+ if (*rthp == rt) {
+ *rthp = rt->u.rt_next;
+ rt_free(rt);
+ break;
+ }
+ spin_unlock_bh(&rt_hash_table[hash].lock);
+}
+
+void ip_rt_redirect(u32 old_gw, u32 daddr, u32 new_gw,
+ u32 saddr, u8 tos, struct net_device *dev)
+{
+ int i, k;
+ struct in_device *in_dev = in_dev_get(dev);
+ struct rtable *rth, **rthp;
+ u32 skeys[2] = { saddr, 0 };
+ int ikeys[2] = { dev->ifindex, 0 };
+
+ tos &= IPTOS_RT_MASK;
+
+ if (!in_dev)
+ return;
+
+ if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
+ || MULTICAST(new_gw) || BADCLASS(new_gw) || 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(new_gw) != RTN_UNICAST)
+ goto reject_redirect;
+ }
+
+ for (i = 0; i < 2; i++) {
+ for (k = 0; k < 2; k++) {
+ unsigned hash = rt_hash_code(daddr,
+ skeys[i] ^ (ikeys[k] << 5),
+ tos);
+
+ rthp=&rt_hash_table[hash].chain;
+
+ rcu_read_lock();
+ while ((rth = rcu_dereference(*rthp)) != NULL) {
+ struct rtable *rt;
+
+ if (rth->fl.fl4_dst != daddr ||
+ rth->fl.fl4_src != skeys[i] ||
+ rth->fl.fl4_tos != tos ||
+ rth->fl.oif != ikeys[k] ||
+ rth->fl.iif != 0) {
+ rthp = &rth->u.rt_next;
+ continue;
+ }
+
+ if (rth->rt_dst != daddr ||
+ rth->rt_src != saddr ||
+ rth->u.dst.error ||
+ rth->rt_gateway != old_gw ||
+ rth->u.dst.dev != dev)
+ break;
+
+ dst_hold(&rth->u.dst);
+ rcu_read_unlock();
+
+ rt = dst_alloc(&ipv4_dst_ops);
+ if (rt == NULL) {
+ ip_rt_put(rth);
+ in_dev_put(in_dev);
+ return;
+ }
+
+ /* Copy all the information. */
+ *rt = *rth;
+ INIT_RCU_HEAD(&rt->u.dst.rcu_head);
+ rt->u.dst.__use = 1;
+ atomic_set(&rt->u.dst.__refcnt, 1);
+ rt->u.dst.child = NULL;
+ if (rt->u.dst.dev)
+ dev_hold(rt->u.dst.dev);
+ if (rt->idev)
+ in_dev_hold(rt->idev);
+ rt->u.dst.obsolete = 0;
+ rt->u.dst.lastuse = jiffies;
+ rt->u.dst.path = &rt->u.dst;
+ rt->u.dst.neighbour = NULL;
+ rt->u.dst.hh = NULL;
+ rt->u.dst.xfrm = NULL;
+
+ rt->rt_flags |= RTCF_REDIRECTED;
+
+ /* Gateway is different ... */
+ rt->rt_gateway = new_gw;
+
+ /* Redirect received -> path was valid */
+ dst_confirm(&rth->u.dst);
+
+ if (rt->peer)
+ atomic_inc(&rt->peer->refcnt);
+
+ if (arp_bind_neighbour(&rt->u.dst) ||
+ !(rt->u.dst.neighbour->nud_state &
+ NUD_VALID)) {
+ if (rt->u.dst.neighbour)
+ neigh_event_send(rt->u.dst.neighbour, NULL);
+ ip_rt_put(rth);
+ rt_drop(rt);
+ goto do_next;
+ }
+
+ rt_del(hash, rth);
+ if (!rt_intern_hash(hash, rt, &rt))
+ ip_rt_put(rt);
+ goto do_next;
+ }
+ rcu_read_unlock();
+ do_next:
+ ;
+ }
+ }
+ in_dev_put(in_dev);
+ return;
+
+reject_redirect:
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+ if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
+ printk(KERN_INFO "Redirect from %u.%u.%u.%u on %s about "
+ "%u.%u.%u.%u ignored.\n"
+ " Advised path = %u.%u.%u.%u -> %u.%u.%u.%u, "
+ "tos %02x\n",
+ NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
+ NIPQUAD(saddr), NIPQUAD(daddr), tos);
+#endif
+ in_dev_put(in_dev);
+}
+
+static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
+{
+ struct rtable *rt = (struct rtable*)dst;
+ struct dst_entry *ret = dst;
+
+ if (rt) {
+ if (dst->obsolete) {
+ ip_rt_put(rt);
+ ret = NULL;
+ } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
+ rt->u.dst.expires) {
+ unsigned hash = rt_hash_code(rt->fl.fl4_dst,
+ rt->fl.fl4_src ^
+ (rt->fl.oif << 5),
+ rt->fl.fl4_tos);
+#if RT_CACHE_DEBUG >= 1
+ printk(KERN_DEBUG "ip_rt_advice: redirect to "
+ "%u.%u.%u.%u/%02x dropped\n",
+ NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
+#endif
+ rt_del(hash, rt);
+ ret = NULL;
+ }
+ }
+ return ret;
+}
+
+/*
+ * Algorithm:
+ * 1. The first ip_rt_redirect_number redirects are sent
+ * with exponential backoff, then we stop sending them at all,
+ * assuming that the host ignores our redirects.
+ * 2. If we did not see packets requiring redirects
+ * during ip_rt_redirect_silence, we assume that the host
+ * forgot redirected route and start to send redirects again.
+ *
+ * This algorithm is much cheaper and more intelligent than dumb load limiting
+ * in icmp.c.
+ *
+ * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
+ * and "frag. need" (breaks PMTU discovery) in icmp.c.
+ */
+
+void ip_rt_send_redirect(struct sk_buff *skb)
+{
+ struct rtable *rt = (struct rtable*)skb->dst;
+ struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
+
+ if (!in_dev)
+ return;
+
+ if (!IN_DEV_TX_REDIRECTS(in_dev))
+ goto out;
+
+ /* No redirected packets during ip_rt_redirect_silence;
+ * reset the algorithm.
+ */
+ if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
+ rt->u.dst.rate_tokens = 0;
+
+ /* Too many ignored redirects; do not send anything
+ * set u.dst.rate_last to the last seen redirected packet.
+ */
+ if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
+ rt->u.dst.rate_last = jiffies;
+ goto out;
+ }
+
+ /* Check for load limit; set rate_last to the latest sent
+ * redirect.
+ */
+ if (time_after(jiffies,
+ (rt->u.dst.rate_last +
+ (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
+ icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
+ rt->u.dst.rate_last = jiffies;
+ ++rt->u.dst.rate_tokens;
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+ if (IN_DEV_LOG_MARTIANS(in_dev) &&
+ rt->u.dst.rate_tokens == ip_rt_redirect_number &&
+ net_ratelimit())
+ printk(KERN_WARNING "host %u.%u.%u.%u/if%d ignores "
+ "redirects for %u.%u.%u.%u to %u.%u.%u.%u.\n",
+ NIPQUAD(rt->rt_src), rt->rt_iif,
+ NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
+#endif
+ }
+out:
+ in_dev_put(in_dev);
+}
+
+static int ip_error(struct sk_buff *skb)
+{
+ struct rtable *rt = (struct rtable*)skb->dst;
+ unsigned long now;
+ int code;
+
+ switch (rt->u.dst.error) {
+ case EINVAL:
+ default:
+ goto out;
+ case EHOSTUNREACH:
+ code = ICMP_HOST_UNREACH;
+ break;
+ case ENETUNREACH:
+ code = ICMP_NET_UNREACH;
+ break;
+ case EACCES:
+ code = ICMP_PKT_FILTERED;
+ break;
+ }
+
+ now = jiffies;
+ rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
+ if (rt->u.dst.rate_tokens > ip_rt_error_burst)
+ rt->u.dst.rate_tokens = ip_rt_error_burst;
+ rt->u.dst.rate_last = now;
+ if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
+ rt->u.dst.rate_tokens -= ip_rt_error_cost;
+ icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
+ }
+
+out: kfree_skb(skb);
+ return 0;
+}
+
+/*
+ * The last two values are not from the RFC but
+ * are needed for AMPRnet AX.25 paths.
+ */
+
+static unsigned short mtu_plateau[] =
+{32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
+
+static __inline__ unsigned short guess_mtu(unsigned short old_mtu)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
+ if (old_mtu > mtu_plateau[i])
+ return mtu_plateau[i];
+ return 68;
+}
+
+unsigned short ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu)
+{
+ int i;
+ unsigned short old_mtu = ntohs(iph->tot_len);
+ struct rtable *rth;
+ u32 skeys[2] = { iph->saddr, 0, };
+ u32 daddr = iph->daddr;
+ u8 tos = iph->tos & IPTOS_RT_MASK;
+ unsigned short est_mtu = 0;
+
+ if (ipv4_config.no_pmtu_disc)
+ return 0;
+
+ for (i = 0; i < 2; i++) {
+ unsigned hash = rt_hash_code(daddr, skeys[i], tos);
+
+ rcu_read_lock();
+ for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
+ rth = rcu_dereference(rth->u.rt_next)) {
+ if (rth->fl.fl4_dst == daddr &&
+ rth->fl.fl4_src == skeys[i] &&
+ rth->rt_dst == daddr &&
+ rth->rt_src == iph->saddr &&
+ rth->fl.fl4_tos == tos &&
+ rth->fl.iif == 0 &&
+ !(dst_metric_locked(&rth->u.dst, RTAX_MTU))) {
+ unsigned short mtu = new_mtu;
+
+ if (new_mtu < 68 || new_mtu >= old_mtu) {
+
+ /* BSD 4.2 compatibility hack :-( */
+ if (mtu == 0 &&
+ old_mtu >= rth->u.dst.metrics[RTAX_MTU-1] &&
+ old_mtu >= 68 + (iph->ihl << 2))
+ old_mtu -= iph->ihl << 2;
+
+ mtu = guess_mtu(old_mtu);
+ }
+ if (mtu <= rth->u.dst.metrics[RTAX_MTU-1]) {
+ if (mtu < rth->u.dst.metrics[RTAX_MTU-1]) {
+ dst_confirm(&rth->u.dst);
+ if (mtu < ip_rt_min_pmtu) {
+ mtu = ip_rt_min_pmtu;
+ rth->u.dst.metrics[RTAX_LOCK-1] |=
+ (1 << RTAX_MTU);
+ }
+ rth->u.dst.metrics[RTAX_MTU-1] = mtu;
+ dst_set_expires(&rth->u.dst,
+ ip_rt_mtu_expires);
+ }
+ est_mtu = mtu;
+ }
+ }
+ }
+ rcu_read_unlock();
+ }
+ return est_mtu ? : new_mtu;
+}
+
+static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
+{
+ if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= 68 &&
+ !(dst_metric_locked(dst, RTAX_MTU))) {
+ if (mtu < ip_rt_min_pmtu) {
+ mtu = ip_rt_min_pmtu;
+ dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
+ }
+ dst->metrics[RTAX_MTU-1] = mtu;
+ dst_set_expires(dst, ip_rt_mtu_expires);
+ }
+}
+
+static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
+{
+ return NULL;
+}
+
+static void ipv4_dst_destroy(struct dst_entry *dst)
+{
+ struct rtable *rt = (struct rtable *) dst;
+ struct inet_peer *peer = rt->peer;
+ struct in_device *idev = rt->idev;
+
+ if (peer) {
+ rt->peer = NULL;
+ inet_putpeer(peer);
+ }
+
+ if (idev) {
+ rt->idev = NULL;
+ in_dev_put(idev);
+ }
+}
+
+static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+ int how)
+{
+ struct rtable *rt = (struct rtable *) dst;
+ struct in_device *idev = rt->idev;
+ if (dev != &loopback_dev && idev && idev->dev == dev) {
+ struct in_device *loopback_idev = in_dev_get(&loopback_dev);
+ if (loopback_idev) {
+ rt->idev = loopback_idev;
+ in_dev_put(idev);
+ }
+ }
+}
+
+static void ipv4_link_failure(struct sk_buff *skb)
+{
+ struct rtable *rt;
+
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
+
+ rt = (struct rtable *) skb->dst;
+ if (rt)
+ dst_set_expires(&rt->u.dst, 0);
+}
+
+static int ip_rt_bug(struct sk_buff *skb)
+{
+ printk(KERN_DEBUG "ip_rt_bug: %u.%u.%u.%u -> %u.%u.%u.%u, %s\n",
+ NIPQUAD(skb->nh.iph->saddr), NIPQUAD(skb->nh.iph->daddr),
+ skb->dev ? skb->dev->name : "?");
+ kfree_skb(skb);
+ return 0;
+}
+
+/*
+ We do not cache source address of outgoing interface,
+ because it is used only by IP RR, TS and SRR options,
+ so that it out of fast path.
+
+ BTW remember: "addr" is allowed to be not aligned
+ in IP options!
+ */
+
+void ip_rt_get_source(u8 *addr, struct rtable *rt)
+{
+ u32 src;
+ struct fib_result res;
+
+ if (rt->fl.iif == 0)
+ src = rt->rt_src;
+ else if (fib_lookup(&rt->fl, &res) == 0) {
+ src = FIB_RES_PREFSRC(res);
+ fib_res_put(&res);
+ } else
+ src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
+ RT_SCOPE_UNIVERSE);
+ memcpy(addr, &src, 4);
+}
+
+#ifdef CONFIG_NET_CLS_ROUTE
+static void set_class_tag(struct rtable *rt, u32 tag)
+{
+ if (!(rt->u.dst.tclassid & 0xFFFF))
+ rt->u.dst.tclassid |= tag & 0xFFFF;
+ if (!(rt->u.dst.tclassid & 0xFFFF0000))
+ rt->u.dst.tclassid |= tag & 0xFFFF0000;
+}
+#endif
+
+static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
+{
+ struct fib_info *fi = res->fi;
+
+ if (fi) {
+ if (FIB_RES_GW(*res) &&
+ FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
+ rt->rt_gateway = FIB_RES_GW(*res);
+ memcpy(rt->u.dst.metrics, fi->fib_metrics,
+ sizeof(rt->u.dst.metrics));
+ if (fi->fib_mtu == 0) {
+ rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
+ if (rt->u.dst.metrics[RTAX_LOCK-1] & (1 << RTAX_MTU) &&
+ rt->rt_gateway != rt->rt_dst &&
+ rt->u.dst.dev->mtu > 576)
+ rt->u.dst.metrics[RTAX_MTU-1] = 576;
+ }
+#ifdef CONFIG_NET_CLS_ROUTE
+ rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
+#endif
+ } else
+ rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
+
+ if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
+ rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
+ if (rt->u.dst.metrics[RTAX_MTU-1] > IP_MAX_MTU)
+ rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
+ if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0)
+ rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
+ ip_rt_min_advmss);
+ if (rt->u.dst.metrics[RTAX_ADVMSS-1] > 65535 - 40)
+ rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
+
+#ifdef CONFIG_NET_CLS_ROUTE
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+ set_class_tag(rt, fib_rules_tclass(res));
+#endif
+ set_class_tag(rt, itag);
+#endif
+ rt->rt_type = res->type;
+}
+
+static int ip_route_input_mc(struct sk_buff *skb, u32 daddr, u32 saddr,
+ u8 tos, struct net_device *dev, int our)
+{
+ unsigned hash;
+ struct rtable *rth;
+ u32 spec_dst;
+ struct in_device *in_dev = in_dev_get(dev);
+ u32 itag = 0;
+
+ /* Primary sanity checks. */
+
+ if (in_dev == NULL)
+ return -EINVAL;
+
+ if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr) ||
+ skb->protocol != htons(ETH_P_IP))
+ goto e_inval;
+
+ if (ZERONET(saddr)) {
+ if (!LOCAL_MCAST(daddr))
+ goto e_inval;
+ spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
+ } else if (fib_validate_source(saddr, 0, tos, 0,
+ dev, &spec_dst, &itag) < 0)
+ goto e_inval;
+
+ rth = dst_alloc(&ipv4_dst_ops);
+ if (!rth)
+ goto e_nobufs;
+
+ rth->u.dst.output= ip_rt_bug;
+
+ atomic_set(&rth->u.dst.__refcnt, 1);
+ rth->u.dst.flags= DST_HOST;
+ if (in_dev->cnf.no_policy)
+ rth->u.dst.flags |= DST_NOPOLICY;
+ rth->fl.fl4_dst = daddr;
+ rth->rt_dst = daddr;
+ rth->fl.fl4_tos = tos;
+#ifdef CONFIG_IP_ROUTE_FWMARK
+ rth->fl.fl4_fwmark= skb->nfmark;
+#endif
+ rth->fl.fl4_src = saddr;
+ rth->rt_src = saddr;
+#ifdef CONFIG_NET_CLS_ROUTE
+ rth->u.dst.tclassid = itag;
+#endif
+ rth->rt_iif =
+ rth->fl.iif = dev->ifindex;
+ rth->u.dst.dev = &loopback_dev;
+ dev_hold(rth->u.dst.dev);
+ rth->idev = in_dev_get(rth->u.dst.dev);
+ rth->fl.oif = 0;
+ rth->rt_gateway = daddr;
+ rth->rt_spec_dst= spec_dst;
+ rth->rt_type = RTN_MULTICAST;
+ rth->rt_flags = RTCF_MULTICAST;
+ if (our) {
+ rth->u.dst.input= ip_local_deliver;
+ rth->rt_flags |= RTCF_LOCAL;
+ }
+
+#ifdef CONFIG_IP_MROUTE
+ if (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
+ rth->u.dst.input = ip_mr_input;
+#endif
+ RT_CACHE_STAT_INC(in_slow_mc);
+
+ in_dev_put(in_dev);
+ hash = rt_hash_code(daddr, saddr ^ (dev->ifindex << 5), tos);
+ return rt_intern_hash(hash, rth, (struct rtable**) &skb->dst);
+
+e_nobufs:
+ in_dev_put(in_dev);
+ return -ENOBUFS;
+
+e_inval:
+ in_dev_put(in_dev);
+ return -EINVAL;
+}
+
+
+static void ip_handle_martian_source(struct net_device *dev,
+ struct in_device *in_dev,
+ struct sk_buff *skb,
+ u32 daddr,
+ u32 saddr)
+{
+ RT_CACHE_STAT_INC(in_martian_src);
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+ if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
+ /*
+ * RFC1812 recommendation, if source is martian,
+ * the only hint is MAC header.
+ */
+ printk(KERN_WARNING "martian source %u.%u.%u.%u from "
+ "%u.%u.%u.%u, on dev %s\n",
+ NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
+ if (dev->hard_header_len) {
+ int i;
+ unsigned char *p = skb->mac.raw;
+ printk(KERN_WARNING "ll header: ");
+ for (i = 0; i < dev->hard_header_len; i++, p++) {
+ printk("%02x", *p);
+ if (i < (dev->hard_header_len - 1))
+ printk(":");
+ }
+ printk("\n");
+ }
+ }
+#endif
+}
+
+static inline int __mkroute_input(struct sk_buff *skb,
+ struct fib_result* res,
+ struct in_device *in_dev,
+ u32 daddr, u32 saddr, u32 tos,
+ struct rtable **result)
+{
+
+ struct rtable *rth;
+ int err;
+ struct in_device *out_dev;
+ unsigned flags = 0;
+ u32 spec_dst, itag;
+
+ /* get a working reference to the output device */
+ out_dev = in_dev_get(FIB_RES_DEV(*res));
+ if (out_dev == NULL) {
+ if (net_ratelimit())
+ printk(KERN_CRIT "Bug in ip_route_input" \
+ "_slow(). Please, report\n");
+ return -EINVAL;
+ }
+
+
+ err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
+ in_dev->dev, &spec_dst, &itag);
+ if (err < 0) {
+ ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
+ saddr);
+
+ err = -EINVAL;
+ goto cleanup;
+ }
+
+ if (err)
+ flags |= RTCF_DIRECTSRC;
+
+ if (out_dev == in_dev && err && !(flags & (RTCF_NAT | RTCF_MASQ)) &&
+ (IN_DEV_SHARED_MEDIA(out_dev) ||
+ inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
+ flags |= RTCF_DOREDIRECT;
+
+ if (skb->protocol != htons(ETH_P_IP)) {
+ /* Not IP (i.e. ARP). Do not create route, if it is
+ * invalid for proxy arp. DNAT routes are always valid.
+ */
+ if (out_dev == in_dev && !(flags & RTCF_DNAT)) {
+ err = -EINVAL;
+ goto cleanup;
+ }
+ }
+
+
+ rth = dst_alloc(&ipv4_dst_ops);
+ if (!rth) {
+ err = -ENOBUFS;
+ goto cleanup;
+ }
+
+ rth->u.dst.flags= DST_HOST;
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ if (res->fi->fib_nhs > 1)
+ rth->u.dst.flags |= DST_BALANCED;
+#endif
+ if (in_dev->cnf.no_policy)
+ rth->u.dst.flags |= DST_NOPOLICY;
+ if (in_dev->cnf.no_xfrm)
+ rth->u.dst.flags |= DST_NOXFRM;
+ rth->fl.fl4_dst = daddr;
+ rth->rt_dst = daddr;
+ rth->fl.fl4_tos = tos;
+#ifdef CONFIG_IP_ROUTE_FWMARK
+ rth->fl.fl4_fwmark= skb->nfmark;
+#endif
+ rth->fl.fl4_src = saddr;
+ rth->rt_src = saddr;
+ rth->rt_gateway = daddr;
+ rth->rt_iif =
+ rth->fl.iif = in_dev->dev->ifindex;
+ rth->u.dst.dev = (out_dev)->dev;
+ dev_hold(rth->u.dst.dev);
+ rth->idev = in_dev_get(rth->u.dst.dev);
+ rth->fl.oif = 0;
+ rth->rt_spec_dst= spec_dst;
+
+ rth->u.dst.input = ip_forward;
+ rth->u.dst.output = ip_output;
+
+ rt_set_nexthop(rth, res, itag);
+
+ rth->rt_flags = flags;
+
+ *result = rth;
+ err = 0;
+ cleanup:
+ /* release the working reference to the output device */
+ in_dev_put(out_dev);
+ return err;
+}
+
+static inline int ip_mkroute_input_def(struct sk_buff *skb,
+ struct fib_result* res,
+ const struct flowi *fl,
+ struct in_device *in_dev,
+ u32 daddr, u32 saddr, u32 tos)
+{
+ struct rtable* rth;
+ int err;
+ unsigned hash;
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
+ fib_select_multipath(fl, res);
+#endif
+
+ /* create a routing cache entry */
+ err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
+ if (err)
+ return err;
+ atomic_set(&rth->u.dst.__refcnt, 1);
+
+ /* put it into the cache */
+ hash = rt_hash_code(daddr, saddr ^ (fl->iif << 5), tos);
+ return rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
+}
+
+static inline int ip_mkroute_input(struct sk_buff *skb,
+ struct fib_result* res,
+ const struct flowi *fl,
+ struct in_device *in_dev,
+ u32 daddr, u32 saddr, u32 tos)
+{
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ struct rtable* rth;
+ unsigned char hop, hopcount, lasthop;
+ int err = -EINVAL;
+ unsigned int hash;
+
+ if (res->fi)
+ hopcount = res->fi->fib_nhs;
+ else
+ hopcount = 1;
+
+ lasthop = hopcount - 1;
+
+ /* distinguish between multipath and singlepath */
+ if (hopcount < 2)
+ return ip_mkroute_input_def(skb, res, fl, in_dev, daddr,
+ saddr, tos);
+
+ /* add all alternatives to the routing cache */
+ for (hop = 0; hop < hopcount; hop++) {
+ res->nh_sel = hop;
+
+ /* create a routing cache entry */
+ err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos,
+ &rth);
+ if (err)
+ return err;
+
+ /* put it into the cache */
+ hash = rt_hash_code(daddr, saddr ^ (fl->iif << 5), tos);
+ err = rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
+ if (err)
+ return err;
+
+ /* forward hop information to multipath impl. */
+ multipath_set_nhinfo(rth,
+ FIB_RES_NETWORK(*res),
+ FIB_RES_NETMASK(*res),
+ res->prefixlen,
+ &FIB_RES_NH(*res));
+
+ /* only for the last hop the reference count is handled
+ * outside
+ */
+ if (hop == lasthop)
+ atomic_set(&(skb->dst->__refcnt), 1);
+ }
+ return err;
+#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
+ return ip_mkroute_input_def(skb, res, fl, in_dev, daddr, saddr, tos);
+#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
+}
+
+
+/*
+ * NOTE. We drop all the packets that has local source
+ * addresses, because every properly looped back packet
+ * must have correct destination already attached by output routine.
+ *
+ * Such approach solves two big problems:
+ * 1. Not simplex devices are handled properly.
+ * 2. IP spoofing attempts are filtered with 100% of guarantee.
+ */
+
+static int ip_route_input_slow(struct sk_buff *skb, u32 daddr, u32 saddr,
+ u8 tos, struct net_device *dev)
+{
+ struct fib_result res;
+ struct in_device *in_dev = in_dev_get(dev);
+ struct flowi fl = { .nl_u = { .ip4_u =
+ { .daddr = daddr,
+ .saddr = saddr,
+ .tos = tos,
+ .scope = RT_SCOPE_UNIVERSE,
+#ifdef CONFIG_IP_ROUTE_FWMARK
+ .fwmark = skb->nfmark
+#endif
+ } },
+ .iif = dev->ifindex };
+ unsigned flags = 0;
+ u32 itag = 0;
+ struct rtable * rth;
+ unsigned hash;
+ u32 spec_dst;
+ int err = -EINVAL;
+ int free_res = 0;
+
+ /* 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 (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr))
+ goto martian_source;
+
+ if (daddr == 0xFFFFFFFF || (saddr == 0 && daddr == 0))
+ goto brd_input;
+
+ /* Accept zero addresses only to limited broadcast;
+ * I even do not know to fix it or not. Waiting for complains :-)
+ */
+ if (ZERONET(saddr))
+ goto martian_source;
+
+ if (BADCLASS(daddr) || ZERONET(daddr) || LOOPBACK(daddr))
+ goto martian_destination;
+
+ /*
+ * Now we are ready to route packet.
+ */
+ if ((err = fib_lookup(&fl, &res)) != 0) {
+ if (!IN_DEV_FORWARD(in_dev))
+ goto e_inval;
+ goto no_route;
+ }
+ free_res = 1;
+
+ RT_CACHE_STAT_INC(in_slow_tot);
+
+ if (res.type == RTN_BROADCAST)
+ goto brd_input;
+
+ if (res.type == RTN_LOCAL) {
+ int result;
+ result = fib_validate_source(saddr, daddr, tos,
+ loopback_dev.ifindex,
+ dev, &spec_dst, &itag);
+ if (result < 0)
+ goto martian_source;
+ if (result)
+ flags |= RTCF_DIRECTSRC;
+ spec_dst = daddr;
+ goto local_input;
+ }
+
+ if (!IN_DEV_FORWARD(in_dev))
+ goto e_inval;
+ if (res.type != RTN_UNICAST)
+ goto martian_destination;
+
+ err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
+ if (err == -ENOBUFS)
+ goto e_nobufs;
+ if (err == -EINVAL)
+ goto e_inval;
+
+done:
+ in_dev_put(in_dev);
+ if (free_res)
+ fib_res_put(&res);
+out: return err;
+
+brd_input:
+ if (skb->protocol != htons(ETH_P_IP))
+ goto e_inval;
+
+ if (ZERONET(saddr))
+ spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
+ else {
+ err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
+ &itag);
+ if (err < 0)
+ goto martian_source;
+ if (err)
+ flags |= RTCF_DIRECTSRC;
+ }
+ flags |= RTCF_BROADCAST;
+ res.type = RTN_BROADCAST;
+ RT_CACHE_STAT_INC(in_brd);
+
+local_input:
+ rth = dst_alloc(&ipv4_dst_ops);
+ if (!rth)
+ goto e_nobufs;
+
+ rth->u.dst.output= ip_rt_bug;
+
+ atomic_set(&rth->u.dst.__refcnt, 1);
+ rth->u.dst.flags= DST_HOST;
+ if (in_dev->cnf.no_policy)
+ rth->u.dst.flags |= DST_NOPOLICY;
+ rth->fl.fl4_dst = daddr;
+ rth->rt_dst = daddr;
+ rth->fl.fl4_tos = tos;
+#ifdef CONFIG_IP_ROUTE_FWMARK
+ rth->fl.fl4_fwmark= skb->nfmark;
+#endif
+ rth->fl.fl4_src = saddr;
+ rth->rt_src = saddr;
+#ifdef CONFIG_NET_CLS_ROUTE
+ rth->u.dst.tclassid = itag;
+#endif
+ rth->rt_iif =
+ rth->fl.iif = dev->ifindex;
+ rth->u.dst.dev = &loopback_dev;
+ dev_hold(rth->u.dst.dev);
+ rth->idev = in_dev_get(rth->u.dst.dev);
+ rth->rt_gateway = daddr;
+ rth->rt_spec_dst= spec_dst;
+ rth->u.dst.input= ip_local_deliver;
+ rth->rt_flags = flags|RTCF_LOCAL;
+ if (res.type == RTN_UNREACHABLE) {
+ rth->u.dst.input= ip_error;
+ rth->u.dst.error= -err;
+ rth->rt_flags &= ~RTCF_LOCAL;
+ }
+ rth->rt_type = res.type;
+ hash = rt_hash_code(daddr, saddr ^ (fl.iif << 5), tos);
+ err = rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
+ goto done;
+
+no_route:
+ RT_CACHE_STAT_INC(in_no_route);
+ spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
+ res.type = RTN_UNREACHABLE;
+ goto local_input;
+
+ /*
+ * Do not cache martian addresses: they should be logged (RFC1812)
+ */
+martian_destination:
+ RT_CACHE_STAT_INC(in_martian_dst);
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+ if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
+ printk(KERN_WARNING "martian destination %u.%u.%u.%u from "
+ "%u.%u.%u.%u, dev %s\n",
+ NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
+#endif
+e_inval:
+ err = -EINVAL;
+ goto done;
+
+e_nobufs:
+ err = -ENOBUFS;
+ goto done;
+
+martian_source:
+ ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
+ goto e_inval;
+}
+
+int ip_route_input(struct sk_buff *skb, u32 daddr, u32 saddr,
+ u8 tos, struct net_device *dev)
+{
+ struct rtable * rth;
+ unsigned hash;
+ int iif = dev->ifindex;
+
+ tos &= IPTOS_RT_MASK;
+ hash = rt_hash_code(daddr, saddr ^ (iif << 5), tos);
+
+ rcu_read_lock();
+ for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
+ rth = rcu_dereference(rth->u.rt_next)) {
+ if (rth->fl.fl4_dst == daddr &&
+ rth->fl.fl4_src == saddr &&
+ rth->fl.iif == iif &&
+ rth->fl.oif == 0 &&
+#ifdef CONFIG_IP_ROUTE_FWMARK
+ rth->fl.fl4_fwmark == skb->nfmark &&
+#endif
+ rth->fl.fl4_tos == tos) {
+ rth->u.dst.lastuse = jiffies;
+ dst_hold(&rth->u.dst);
+ rth->u.dst.__use++;
+ RT_CACHE_STAT_INC(in_hit);
+ rcu_read_unlock();
+ skb->dst = (struct dst_entry*)rth;
+ return 0;
+ }
+ RT_CACHE_STAT_INC(in_hlist_search);
+ }
+ rcu_read_unlock();
+
+ /* Multicast recognition logic is moved from route cache to here.
+ The problem was that too many Ethernet cards have broken/missing
+ hardware multicast filters :-( As result the host on multicasting
+ network acquires a lot of useless route cache entries, sort of
+ SDR messages from all the world. Now we try to get rid of them.
+ Really, provided software IP multicast filter is organized
+ reasonably (at least, hashed), it does not result in a slowdown
+ comparing with route cache reject entries.
+ Note, that multicast routers are not affected, because
+ route cache entry is created eventually.
+ */
+ if (MULTICAST(daddr)) {
+ struct in_device *in_dev;
+
+ rcu_read_lock();
+ if ((in_dev = __in_dev_get(dev)) != NULL) {
+ int our = ip_check_mc(in_dev, daddr, saddr,
+ skb->nh.iph->protocol);
+ if (our
+#ifdef CONFIG_IP_MROUTE
+ || (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
+#endif
+ ) {
+ rcu_read_unlock();
+ return ip_route_input_mc(skb, daddr, saddr,
+ tos, dev, our);
+ }
+ }
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+ return ip_route_input_slow(skb, daddr, saddr, tos, dev);
+}
+
+static inline int __mkroute_output(struct rtable **result,
+ struct fib_result* res,
+ const struct flowi *fl,
+ const struct flowi *oldflp,
+ struct net_device *dev_out,
+ unsigned flags)
+{
+ struct rtable *rth;
+ struct in_device *in_dev;
+ u32 tos = RT_FL_TOS(oldflp);
+ int err = 0;
+
+ if (LOOPBACK(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
+ return -EINVAL;
+
+ if (fl->fl4_dst == 0xFFFFFFFF)
+ res->type = RTN_BROADCAST;
+ else if (MULTICAST(fl->fl4_dst))
+ res->type = RTN_MULTICAST;
+ else if (BADCLASS(fl->fl4_dst) || ZERONET(fl->fl4_dst))
+ return -EINVAL;
+
+ if (dev_out->flags & IFF_LOOPBACK)
+ flags |= RTCF_LOCAL;
+
+ /* get work reference to inet device */
+ in_dev = in_dev_get(dev_out);
+ if (!in_dev)
+ return -EINVAL;
+
+ if (res->type == RTN_BROADCAST) {
+ flags |= RTCF_BROADCAST | RTCF_LOCAL;
+ if (res->fi) {
+ fib_info_put(res->fi);
+ res->fi = NULL;
+ }
+ } else if (res->type == RTN_MULTICAST) {
+ flags |= RTCF_MULTICAST|RTCF_LOCAL;
+ if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
+ oldflp->proto))
+ flags &= ~RTCF_LOCAL;
+ /* If multicast route do not exist use
+ default one, but do not gateway in this case.
+ Yes, it is hack.
+ */
+ if (res->fi && res->prefixlen < 4) {
+ fib_info_put(res->fi);
+ res->fi = NULL;
+ }
+ }
+
+
+ rth = dst_alloc(&ipv4_dst_ops);
+ if (!rth) {
+ err = -ENOBUFS;
+ goto cleanup;
+ }
+
+ rth->u.dst.flags= DST_HOST;
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ if (res->fi) {
+ rth->rt_multipath_alg = res->fi->fib_mp_alg;
+ if (res->fi->fib_nhs > 1)
+ rth->u.dst.flags |= DST_BALANCED;
+ }
+#endif
+ if (in_dev->cnf.no_xfrm)
+ rth->u.dst.flags |= DST_NOXFRM;
+ if (in_dev->cnf.no_policy)
+ rth->u.dst.flags |= DST_NOPOLICY;
+
+ rth->fl.fl4_dst = oldflp->fl4_dst;
+ rth->fl.fl4_tos = tos;
+ rth->fl.fl4_src = oldflp->fl4_src;
+ rth->fl.oif = oldflp->oif;
+#ifdef CONFIG_IP_ROUTE_FWMARK
+ rth->fl.fl4_fwmark= oldflp->fl4_fwmark;
+#endif
+ rth->rt_dst = fl->fl4_dst;
+ rth->rt_src = fl->fl4_src;
+ rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
+ /* get references to the devices that are to be hold by the routing
+ cache entry */
+ rth->u.dst.dev = dev_out;
+ dev_hold(dev_out);
+ rth->idev = in_dev_get(dev_out);
+ rth->rt_gateway = fl->fl4_dst;
+ rth->rt_spec_dst= fl->fl4_src;
+
+ rth->u.dst.output=ip_output;
+
+ RT_CACHE_STAT_INC(out_slow_tot);
+
+ if (flags & RTCF_LOCAL) {
+ rth->u.dst.input = ip_local_deliver;
+ rth->rt_spec_dst = fl->fl4_dst;
+ }
+ if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
+ rth->rt_spec_dst = fl->fl4_src;
+ if (flags & RTCF_LOCAL &&
+ !(dev_out->flags & IFF_LOOPBACK)) {
+ rth->u.dst.output = ip_mc_output;
+ RT_CACHE_STAT_INC(out_slow_mc);
+ }
+#ifdef CONFIG_IP_MROUTE
+ if (res->type == RTN_MULTICAST) {
+ if (IN_DEV_MFORWARD(in_dev) &&
+ !LOCAL_MCAST(oldflp->fl4_dst)) {
+ rth->u.dst.input = ip_mr_input;
+ rth->u.dst.output = ip_mc_output;
+ }
+ }
+#endif
+ }
+
+ rt_set_nexthop(rth, res, 0);
+
+ rth->rt_flags = flags;
+
+ *result = rth;
+ cleanup:
+ /* release work reference to inet device */
+ in_dev_put(in_dev);
+
+ return err;
+}
+
+static inline int ip_mkroute_output_def(struct rtable **rp,
+ struct fib_result* res,
+ const struct flowi *fl,
+ const struct flowi *oldflp,
+ struct net_device *dev_out,
+ unsigned flags)
+{
+ struct rtable *rth;
+ int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
+ unsigned hash;
+ if (err == 0) {
+ u32 tos = RT_FL_TOS(oldflp);
+
+ atomic_set(&rth->u.dst.__refcnt, 1);
+
+ hash = rt_hash_code(oldflp->fl4_dst,
+ oldflp->fl4_src ^ (oldflp->oif << 5), tos);
+ err = rt_intern_hash(hash, rth, rp);
+ }
+
+ return err;
+}
+
+static inline int ip_mkroute_output(struct rtable** rp,
+ struct fib_result* res,
+ const struct flowi *fl,
+ const struct flowi *oldflp,
+ struct net_device *dev_out,
+ unsigned flags)
+{
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ u32 tos = RT_FL_TOS(oldflp);
+ unsigned char hop;
+ unsigned hash;
+ int err = -EINVAL;
+ struct rtable *rth;
+
+ if (res->fi && res->fi->fib_nhs > 1) {
+ unsigned char hopcount = res->fi->fib_nhs;
+
+ for (hop = 0; hop < hopcount; hop++) {
+ struct net_device *dev2nexthop;
+
+ res->nh_sel = hop;
+
+ /* hold a work reference to the output device */
+ dev2nexthop = FIB_RES_DEV(*res);
+ dev_hold(dev2nexthop);
+
+ err = __mkroute_output(&rth, res, fl, oldflp,
+ dev2nexthop, flags);
+
+ if (err != 0)
+ goto cleanup;
+
+ hash = rt_hash_code(oldflp->fl4_dst,
+ oldflp->fl4_src ^
+ (oldflp->oif << 5), tos);
+ err = rt_intern_hash(hash, rth, rp);
+
+ /* forward hop information to multipath impl. */
+ multipath_set_nhinfo(rth,
+ FIB_RES_NETWORK(*res),
+ FIB_RES_NETMASK(*res),
+ res->prefixlen,
+ &FIB_RES_NH(*res));
+ cleanup:
+ /* release work reference to output device */
+ dev_put(dev2nexthop);
+
+ if (err != 0)
+ return err;
+ }
+ atomic_set(&(*rp)->u.dst.__refcnt, 1);
+ return err;
+ } else {
+ return ip_mkroute_output_def(rp, res, fl, oldflp, dev_out,
+ flags);
+ }
+#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
+ return ip_mkroute_output_def(rp, res, fl, oldflp, dev_out, flags);
+#endif
+}
+
+/*
+ * Major route resolver routine.
+ */
+
+static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
+{
+ u32 tos = RT_FL_TOS(oldflp);
+ struct flowi fl = { .nl_u = { .ip4_u =
+ { .daddr = oldflp->fl4_dst,
+ .saddr = oldflp->fl4_src,
+ .tos = tos & IPTOS_RT_MASK,
+ .scope = ((tos & RTO_ONLINK) ?
+ RT_SCOPE_LINK :
+ RT_SCOPE_UNIVERSE),
+#ifdef CONFIG_IP_ROUTE_FWMARK
+ .fwmark = oldflp->fl4_fwmark
+#endif
+ } },
+ .iif = loopback_dev.ifindex,
+ .oif = oldflp->oif };
+ struct fib_result res;
+ unsigned flags = 0;
+ struct net_device *dev_out = NULL;
+ int free_res = 0;
+ int err;
+
+
+ res.fi = NULL;
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+ res.r = NULL;
+#endif
+
+ if (oldflp->fl4_src) {
+ err = -EINVAL;
+ if (MULTICAST(oldflp->fl4_src) ||
+ BADCLASS(oldflp->fl4_src) ||
+ ZERONET(oldflp->fl4_src))
+ goto out;
+
+ /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+ dev_out = ip_dev_find(oldflp->fl4_src);
+ if (dev_out == NULL)
+ goto out;
+
+ /* I removed check for oif == dev_out->oif here.
+ It was wrong for two reasons:
+ 1. ip_dev_find(saddr) can return wrong iface, if saddr is
+ assigned to multiple interfaces.
+ 2. Moreover, we are allowed to send packets with saddr
+ of another iface. --ANK
+ */
+
+ if (oldflp->oif == 0
+ && (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst == 0xFFFFFFFF)) {
+ /* Special hack: user can direct multicasts
+ and limited broadcast via necessary interface
+ without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
+ This hack is not just for fun, it allows
+ vic,vat and friends to work.
+ They bind socket to loopback, set ttl to zero
+ and expect that it will work.
+ From the viewpoint of routing cache they are broken,
+ because we are not allowed to build multicast path
+ with loopback source addr (look, routing cache
+ cannot know, that ttl is zero, so that packet
+ will not leave this host and route is valid).
+ Luckily, this hack is good workaround.
+ */
+
+ fl.oif = dev_out->ifindex;
+ goto make_route;
+ }
+ if (dev_out)
+ dev_put(dev_out);
+ dev_out = NULL;
+ }
+
+
+ if (oldflp->oif) {
+ dev_out = dev_get_by_index(oldflp->oif);
+ err = -ENODEV;
+ if (dev_out == NULL)
+ goto out;
+ if (__in_dev_get(dev_out) == NULL) {
+ dev_put(dev_out);
+ goto out; /* Wrong error code */
+ }
+
+ if (LOCAL_MCAST(oldflp->fl4_dst) || oldflp->fl4_dst == 0xFFFFFFFF) {
+ if (!fl.fl4_src)
+ fl.fl4_src = inet_select_addr(dev_out, 0,
+ RT_SCOPE_LINK);
+ goto make_route;
+ }
+ if (!fl.fl4_src) {
+ if (MULTICAST(oldflp->fl4_dst))
+ fl.fl4_src = inet_select_addr(dev_out, 0,
+ fl.fl4_scope);
+ else if (!oldflp->fl4_dst)
+ fl.fl4_src = inet_select_addr(dev_out, 0,
+ RT_SCOPE_HOST);
+ }
+ }
+
+ if (!fl.fl4_dst) {
+ fl.fl4_dst = fl.fl4_src;
+ if (!fl.fl4_dst)
+ fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
+ if (dev_out)
+ dev_put(dev_out);
+ dev_out = &loopback_dev;
+ dev_hold(dev_out);
+ fl.oif = loopback_dev.ifindex;
+ res.type = RTN_LOCAL;
+ flags |= RTCF_LOCAL;
+ goto make_route;
+ }
+
+ if (fib_lookup(&fl, &res)) {
+ res.fi = NULL;
+ if (oldflp->oif) {
+ /* Apparently, routing tables are wrong. Assume,
+ that the destination is on link.
+
+ WHY? DW.
+ Because we are allowed to send to iface
+ even if it has NO routes and NO assigned
+ addresses. When oif is specified, routing
+ tables are looked up with only one purpose:
+ to catch if destination is gatewayed, rather than
+ direct. Moreover, if MSG_DONTROUTE is set,
+ we send packet, ignoring both routing tables
+ and ifaddr state. --ANK
+
+
+ We could make it even if oif is unknown,
+ likely IPv6, but we do not.
+ */
+
+ if (fl.fl4_src == 0)
+ fl.fl4_src = inet_select_addr(dev_out, 0,
+ RT_SCOPE_LINK);
+ res.type = RTN_UNICAST;
+ goto make_route;
+ }
+ if (dev_out)
+ dev_put(dev_out);
+ err = -ENETUNREACH;
+ goto out;
+ }
+ free_res = 1;
+
+ if (res.type == RTN_LOCAL) {
+ if (!fl.fl4_src)
+ fl.fl4_src = fl.fl4_dst;
+ if (dev_out)
+ dev_put(dev_out);
+ dev_out = &loopback_dev;
+ dev_hold(dev_out);
+ fl.oif = dev_out->ifindex;
+ if (res.fi)
+ fib_info_put(res.fi);
+ res.fi = NULL;
+ flags |= RTCF_LOCAL;
+ goto make_route;
+ }
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (res.fi->fib_nhs > 1 && fl.oif == 0)
+ fib_select_multipath(&fl, &res);
+ else
+#endif
+ if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
+ fib_select_default(&fl, &res);
+
+ if (!fl.fl4_src)
+ fl.fl4_src = FIB_RES_PREFSRC(res);
+
+ if (dev_out)
+ dev_put(dev_out);
+ dev_out = FIB_RES_DEV(res);
+ dev_hold(dev_out);
+ fl.oif = dev_out->ifindex;
+
+
+make_route:
+ err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
+
+
+ if (free_res)
+ fib_res_put(&res);
+ if (dev_out)
+ dev_put(dev_out);
+out: return err;
+}
+
+int __ip_route_output_key(struct rtable **rp, const struct flowi *flp)
+{
+ unsigned hash;
+ struct rtable *rth;
+
+ hash = rt_hash_code(flp->fl4_dst, flp->fl4_src ^ (flp->oif << 5), flp->fl4_tos);
+
+ rcu_read_lock_bh();
+ for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
+ rth = rcu_dereference(rth->u.rt_next)) {
+ if (rth->fl.fl4_dst == flp->fl4_dst &&
+ rth->fl.fl4_src == flp->fl4_src &&
+ rth->fl.iif == 0 &&
+ rth->fl.oif == flp->oif &&
+#ifdef CONFIG_IP_ROUTE_FWMARK
+ rth->fl.fl4_fwmark == flp->fl4_fwmark &&
+#endif
+ !((rth->fl.fl4_tos ^ flp->fl4_tos) &
+ (IPTOS_RT_MASK | RTO_ONLINK))) {
+
+ /* check for multipath routes and choose one if
+ * necessary
+ */
+ if (multipath_select_route(flp, rth, rp)) {
+ dst_hold(&(*rp)->u.dst);
+ RT_CACHE_STAT_INC(out_hit);
+ rcu_read_unlock_bh();
+ return 0;
+ }
+
+ rth->u.dst.lastuse = jiffies;
+ dst_hold(&rth->u.dst);
+ rth->u.dst.__use++;
+ RT_CACHE_STAT_INC(out_hit);
+ rcu_read_unlock_bh();
+ *rp = rth;
+ return 0;
+ }
+ RT_CACHE_STAT_INC(out_hlist_search);
+ }
+ rcu_read_unlock_bh();
+
+ return ip_route_output_slow(rp, flp);
+}
+
+int ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags)
+{
+ int err;
+
+ if ((err = __ip_route_output_key(rp, flp)) != 0)
+ return err;
+
+ if (flp->proto) {
+ if (!flp->fl4_src)
+ flp->fl4_src = (*rp)->rt_src;
+ if (!flp->fl4_dst)
+ flp->fl4_dst = (*rp)->rt_dst;
+ return xfrm_lookup((struct dst_entry **)rp, flp, sk, flags);
+ }
+
+ return 0;
+}
+
+int ip_route_output_key(struct rtable **rp, struct flowi *flp)
+{
+ return ip_route_output_flow(rp, flp, NULL, 0);
+}
+
+static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
+ int nowait)
+{
+ struct rtable *rt = (struct rtable*)skb->dst;
+ struct rtmsg *r;
+ struct nlmsghdr *nlh;
+ unsigned char *b = skb->tail;
+ struct rta_cacheinfo ci;
+#ifdef CONFIG_IP_MROUTE
+ struct rtattr *eptr;
+#endif
+ nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*r));
+ r = NLMSG_DATA(nlh);
+ nlh->nlmsg_flags = (nowait && pid) ? NLM_F_MULTI : 0;
+ r->rtm_family = AF_INET;
+ r->rtm_dst_len = 32;
+ r->rtm_src_len = 0;
+ r->rtm_tos = rt->fl.fl4_tos;
+ r->rtm_table = RT_TABLE_MAIN;
+ 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;
+ RTA_PUT(skb, RTA_DST, 4, &rt->rt_dst);
+ if (rt->fl.fl4_src) {
+ r->rtm_src_len = 32;
+ RTA_PUT(skb, RTA_SRC, 4, &rt->fl.fl4_src);
+ }
+ if (rt->u.dst.dev)
+ RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->u.dst.dev->ifindex);
+#ifdef CONFIG_NET_CLS_ROUTE
+ if (rt->u.dst.tclassid)
+ RTA_PUT(skb, RTA_FLOW, 4, &rt->u.dst.tclassid);
+#endif
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ if (rt->rt_multipath_alg != IP_MP_ALG_NONE) {
+ __u32 alg = rt->rt_multipath_alg;
+
+ RTA_PUT(skb, RTA_MP_ALGO, 4, &alg);
+ }
+#endif
+ if (rt->fl.iif)
+ RTA_PUT(skb, RTA_PREFSRC, 4, &rt->rt_spec_dst);
+ else if (rt->rt_src != rt->fl.fl4_src)
+ RTA_PUT(skb, RTA_PREFSRC, 4, &rt->rt_src);
+ if (rt->rt_dst != rt->rt_gateway)
+ RTA_PUT(skb, RTA_GATEWAY, 4, &rt->rt_gateway);
+ if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
+ goto rtattr_failure;
+ ci.rta_lastuse = jiffies_to_clock_t(jiffies - rt->u.dst.lastuse);
+ ci.rta_used = rt->u.dst.__use;
+ ci.rta_clntref = atomic_read(&rt->u.dst.__refcnt);
+ if (rt->u.dst.expires)
+ ci.rta_expires = jiffies_to_clock_t(rt->u.dst.expires - jiffies);
+ else
+ ci.rta_expires = 0;
+ ci.rta_error = rt->u.dst.error;
+ ci.rta_id = ci.rta_ts = ci.rta_tsage = 0;
+ if (rt->peer) {
+ ci.rta_id = rt->peer->ip_id_count;
+ if (rt->peer->tcp_ts_stamp) {
+ ci.rta_ts = rt->peer->tcp_ts;
+ ci.rta_tsage = xtime.tv_sec - rt->peer->tcp_ts_stamp;
+ }
+ }
+#ifdef CONFIG_IP_MROUTE
+ eptr = (struct rtattr*)skb->tail;
+#endif
+ RTA_PUT(skb, RTA_CACHEINFO, sizeof(ci), &ci);
+ if (rt->fl.iif) {
+#ifdef CONFIG_IP_MROUTE
+ u32 dst = rt->rt_dst;
+
+ if (MULTICAST(dst) && !LOCAL_MCAST(dst) &&
+ ipv4_devconf.mc_forwarding) {
+ int err = ipmr_get_route(skb, r, nowait);
+ if (err <= 0) {
+ if (!nowait) {
+ if (err == 0)
+ return 0;
+ goto nlmsg_failure;
+ } else {
+ if (err == -EMSGSIZE)
+ goto nlmsg_failure;
+ ((struct rta_cacheinfo*)RTA_DATA(eptr))->rta_error = err;
+ }
+ }
+ } else
+#endif
+ RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fl.iif);
+ }
+
+ nlh->nlmsg_len = skb->tail - b;
+ return skb->len;
+
+nlmsg_failure:
+rtattr_failure:
+ skb_trim(skb, b - skb->data);
+ return -1;
+}
+
+int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
+{
+ struct rtattr **rta = arg;
+ struct rtmsg *rtm = NLMSG_DATA(nlh);
+ struct rtable *rt = NULL;
+ u32 dst = 0;
+ u32 src = 0;
+ int iif = 0;
+ int err = -ENOBUFS;
+ struct sk_buff *skb;
+
+ skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (!skb)
+ goto out;
+
+ /* Reserve room for dummy headers, this skb can pass
+ through good chunk of routing engine.
+ */
+ skb->mac.raw = skb->data;
+ skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
+
+ if (rta[RTA_SRC - 1])
+ memcpy(&src, RTA_DATA(rta[RTA_SRC - 1]), 4);
+ if (rta[RTA_DST - 1])
+ memcpy(&dst, RTA_DATA(rta[RTA_DST - 1]), 4);
+ if (rta[RTA_IIF - 1])
+ memcpy(&iif, RTA_DATA(rta[RTA_IIF - 1]), sizeof(int));
+
+ if (iif) {
+ struct net_device *dev = __dev_get_by_index(iif);
+ err = -ENODEV;
+ if (!dev)
+ goto out_free;
+ skb->protocol = htons(ETH_P_IP);
+ skb->dev = dev;
+ local_bh_disable();
+ err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
+ local_bh_enable();
+ rt = (struct rtable*)skb->dst;
+ if (!err && rt->u.dst.error)
+ err = -rt->u.dst.error;
+ } else {
+ struct flowi fl = { .nl_u = { .ip4_u = { .daddr = dst,
+ .saddr = src,
+ .tos = rtm->rtm_tos } } };
+ int oif = 0;
+ if (rta[RTA_OIF - 1])
+ memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
+ fl.oif = oif;
+ err = ip_route_output_key(&rt, &fl);
+ }
+ if (err)
+ goto out_free;
+
+ skb->dst = &rt->u.dst;
+ if (rtm->rtm_flags & RTM_F_NOTIFY)
+ rt->rt_flags |= RTCF_NOTIFY;
+
+ NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
+
+ err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
+ RTM_NEWROUTE, 0);
+ if (!err)
+ goto out_free;
+ if (err < 0) {
+ err = -EMSGSIZE;
+ goto out_free;
+ }
+
+ err = netlink_unicast(rtnl, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
+ if (err > 0)
+ err = 0;
+out: return err;
+
+out_free:
+ kfree_skb(skb);
+ goto out;
+}
+
+int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct rtable *rt;
+ int h, s_h;
+ int idx, s_idx;
+
+ s_h = cb->args[0];
+ s_idx = idx = cb->args[1];
+ for (h = 0; h <= rt_hash_mask; h++) {
+ if (h < s_h) continue;
+ if (h > s_h)
+ s_idx = 0;
+ rcu_read_lock_bh();
+ for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
+ rt = rcu_dereference(rt->u.rt_next), idx++) {
+ if (idx < s_idx)
+ continue;
+ skb->dst = dst_clone(&rt->u.dst);
+ if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
+ cb->nlh->nlmsg_seq,
+ RTM_NEWROUTE, 1) <= 0) {
+ dst_release(xchg(&skb->dst, NULL));
+ rcu_read_unlock_bh();
+ goto done;
+ }
+ dst_release(xchg(&skb->dst, NULL));
+ }
+ rcu_read_unlock_bh();
+ }
+
+done:
+ cb->args[0] = h;
+ cb->args[1] = idx;
+ return skb->len;
+}
+
+void ip_rt_multicast_event(struct in_device *in_dev)
+{
+ rt_cache_flush(0);
+}
+
+#ifdef CONFIG_SYSCTL
+static int flush_delay;
+
+static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
+ struct file *filp, void __user *buffer,
+ size_t *lenp, loff_t *ppos)
+{
+ if (write) {
+ proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
+ rt_cache_flush(flush_delay);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
+ int __user *name,
+ int nlen,
+ void __user *oldval,
+ size_t __user *oldlenp,
+ void __user *newval,
+ size_t newlen,
+ void **context)
+{
+ int delay;
+ if (newlen != sizeof(int))
+ return -EINVAL;
+ if (get_user(delay, (int __user *)newval))
+ return -EFAULT;
+ rt_cache_flush(delay);
+ return 0;
+}
+
+ctl_table ipv4_route_table[] = {
+ {
+ .ctl_name = NET_IPV4_ROUTE_FLUSH,
+ .procname = "flush",
+ .data = &flush_delay,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &ipv4_sysctl_rtcache_flush,
+ .strategy = &ipv4_sysctl_rtcache_flush_strategy,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_MIN_DELAY,
+ .procname = "min_delay",
+ .data = &ip_rt_min_delay,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_MAX_DELAY,
+ .procname = "max_delay",
+ .data = &ip_rt_max_delay,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
+ .procname = "gc_thresh",
+ .data = &ipv4_dst_ops.gc_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_MAX_SIZE,
+ .procname = "max_size",
+ .data = &ip_rt_max_size,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ /* Deprecated. Use gc_min_interval_ms */
+
+ .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL,
+ .procname = "gc_min_interval",
+ .data = &ip_rt_gc_min_interval,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
+ .procname = "gc_min_interval_ms",
+ .data = &ip_rt_gc_min_interval,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_ms_jiffies,
+ .strategy = &sysctl_ms_jiffies,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT,
+ .procname = "gc_timeout",
+ .data = &ip_rt_gc_timeout,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL,
+ .procname = "gc_interval",
+ .data = &ip_rt_gc_interval,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD,
+ .procname = "redirect_load",
+ .data = &ip_rt_redirect_load,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER,
+ .procname = "redirect_number",
+ .data = &ip_rt_redirect_number,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE,
+ .procname = "redirect_silence",
+ .data = &ip_rt_redirect_silence,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_ERROR_COST,
+ .procname = "error_cost",
+ .data = &ip_rt_error_cost,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_ERROR_BURST,
+ .procname = "error_burst",
+ .data = &ip_rt_error_burst,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY,
+ .procname = "gc_elasticity",
+ .data = &ip_rt_gc_elasticity,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES,
+ .procname = "mtu_expires",
+ .data = &ip_rt_mtu_expires,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_MIN_PMTU,
+ .procname = "min_pmtu",
+ .data = &ip_rt_min_pmtu,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS,
+ .procname = "min_adv_mss",
+ .data = &ip_rt_min_advmss,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL,
+ .procname = "secret_interval",
+ .data = &ip_rt_secret_interval,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
+ { .ctl_name = 0 }
+};
+#endif
+
+#ifdef CONFIG_NET_CLS_ROUTE
+struct ip_rt_acct *ip_rt_acct;
+
+/* This code sucks. But you should have seen it before! --RR */
+
+/* IP route accounting ptr for this logical cpu number. */
+#define IP_RT_ACCT_CPU(i) (ip_rt_acct + i * 256)
+
+#ifdef CONFIG_PROC_FS
+static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
+ int length, int *eof, void *data)
+{
+ unsigned int i;
+
+ if ((offset & 3) || (length & 3))
+ return -EIO;
+
+ if (offset >= sizeof(struct ip_rt_acct) * 256) {
+ *eof = 1;
+ return 0;
+ }
+
+ if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
+ length = sizeof(struct ip_rt_acct) * 256 - offset;
+ *eof = 1;
+ }
+
+ offset /= sizeof(u32);
+
+ if (length > 0) {
+ u32 *src = ((u32 *) IP_RT_ACCT_CPU(0)) + offset;
+ u32 *dst = (u32 *) buffer;
+
+ /* Copy first cpu. */
+ *start = buffer;
+ memcpy(dst, src, length);
+
+ /* Add the other cpus in, one int at a time */
+ for_each_cpu(i) {
+ unsigned int j;
+
+ src = ((u32 *) IP_RT_ACCT_CPU(i)) + offset;
+
+ for (j = 0; j < length/4; j++)
+ dst[j] += src[j];
+ }
+ }
+ return length;
+}
+#endif /* CONFIG_PROC_FS */
+#endif /* CONFIG_NET_CLS_ROUTE */
+
+static __initdata unsigned long rhash_entries;
+static int __init set_rhash_entries(char *str)
+{
+ if (!str)
+ return 0;
+ rhash_entries = simple_strtoul(str, &str, 0);
+ return 1;
+}
+__setup("rhash_entries=", set_rhash_entries);
+
+int __init ip_rt_init(void)
+{
+ int i, order, goal, rc = 0;
+
+ rt_hash_rnd = (int) ((num_physpages ^ (num_physpages>>8)) ^
+ (jiffies ^ (jiffies >> 7)));
+
+#ifdef CONFIG_NET_CLS_ROUTE
+ for (order = 0;
+ (PAGE_SIZE << order) < 256 * sizeof(struct ip_rt_acct) * NR_CPUS; order++)
+ /* NOTHING */;
+ ip_rt_acct = (struct ip_rt_acct *)__get_free_pages(GFP_KERNEL, order);
+ if (!ip_rt_acct)
+ panic("IP: failed to allocate ip_rt_acct\n");
+ memset(ip_rt_acct, 0, PAGE_SIZE << order);
+#endif
+
+ ipv4_dst_ops.kmem_cachep = kmem_cache_create("ip_dst_cache",
+ sizeof(struct rtable),
+ 0, SLAB_HWCACHE_ALIGN,
+ NULL, NULL);
+
+ if (!ipv4_dst_ops.kmem_cachep)
+ panic("IP: failed to allocate ip_dst_cache\n");
+
+ goal = num_physpages >> (26 - PAGE_SHIFT);
+ if (rhash_entries)
+ goal = (rhash_entries * sizeof(struct rt_hash_bucket)) >> PAGE_SHIFT;
+ for (order = 0; (1UL << order) < goal; order++)
+ /* NOTHING */;
+
+ do {
+ rt_hash_mask = (1UL << order) * PAGE_SIZE /
+ sizeof(struct rt_hash_bucket);
+ while (rt_hash_mask & (rt_hash_mask - 1))
+ rt_hash_mask--;
+ rt_hash_table = (struct rt_hash_bucket *)
+ __get_free_pages(GFP_ATOMIC, order);
+ } while (rt_hash_table == NULL && --order > 0);
+
+ if (!rt_hash_table)
+ panic("Failed to allocate IP route cache hash table\n");
+
+ printk(KERN_INFO "IP: routing cache hash table of %u buckets, %ldKbytes\n",
+ rt_hash_mask,
+ (long) (rt_hash_mask * sizeof(struct rt_hash_bucket)) / 1024);
+
+ for (rt_hash_log = 0; (1 << rt_hash_log) != rt_hash_mask; rt_hash_log++)
+ /* NOTHING */;
+
+ rt_hash_mask--;
+ for (i = 0; i <= rt_hash_mask; i++) {
+ spin_lock_init(&rt_hash_table[i].lock);
+ rt_hash_table[i].chain = NULL;
+ }
+
+ ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
+ ip_rt_max_size = (rt_hash_mask + 1) * 16;
+
+ rt_cache_stat = alloc_percpu(struct rt_cache_stat);
+ if (!rt_cache_stat)
+ return -ENOMEM;
+
+ devinet_init();
+ ip_fib_init();
+
+ init_timer(&rt_flush_timer);
+ rt_flush_timer.function = rt_run_flush;
+ init_timer(&rt_periodic_timer);
+ rt_periodic_timer.function = rt_check_expire;
+ init_timer(&rt_secret_timer);
+ rt_secret_timer.function = rt_secret_rebuild;
+
+ /* All the timers, started at system startup tend
+ to synchronize. Perturb it a bit.
+ */
+ rt_periodic_timer.expires = jiffies + net_random() % ip_rt_gc_interval +
+ ip_rt_gc_interval;
+ add_timer(&rt_periodic_timer);
+
+ rt_secret_timer.expires = jiffies + net_random() % ip_rt_secret_interval +
+ ip_rt_secret_interval;
+ add_timer(&rt_secret_timer);
+
+#ifdef CONFIG_PROC_FS
+ {
+ struct proc_dir_entry *rtstat_pde = NULL; /* keep gcc happy */
+ if (!proc_net_fops_create("rt_cache", S_IRUGO, &rt_cache_seq_fops) ||
+ !(rtstat_pde = create_proc_entry("rt_cache", S_IRUGO,
+ proc_net_stat))) {
+ free_percpu(rt_cache_stat);
+ return -ENOMEM;
+ }
+ rtstat_pde->proc_fops = &rt_cpu_seq_fops;
+ }
+#ifdef CONFIG_NET_CLS_ROUTE
+ create_proc_read_entry("rt_acct", 0, proc_net, ip_rt_acct_read, NULL);
+#endif
+#endif
+#ifdef CONFIG_XFRM
+ xfrm_init();
+ xfrm4_init();
+#endif
+ return rc;
+}
+
+EXPORT_SYMBOL(__ip_select_ident);
+EXPORT_SYMBOL(ip_route_input);
+EXPORT_SYMBOL(ip_route_output_key);