![David S. Miller](/assets/img/avatar_default.png)
Three sets of overlapping changes. Nothing serious. Signed-off-by: David S. Miller <davem@davemloft.net>
2937 lines
71 KiB
C
2937 lines
71 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* ROUTE - implementation of the IP router.
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*
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* Authors: Ross Biro
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* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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* Alan Cox, <gw4pts@gw4pts.ampr.org>
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* Linus Torvalds, <Linus.Torvalds@helsinki.fi>
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* Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*
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* Fixes:
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* Alan Cox : Verify area fixes.
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* Alan Cox : cli() protects routing changes
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* Rui Oliveira : ICMP routing table updates
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* (rco@di.uminho.pt) Routing table insertion and update
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* Linus Torvalds : Rewrote bits to be sensible
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* Alan Cox : Added BSD route gw semantics
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* Alan Cox : Super /proc >4K
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* Alan Cox : MTU in route table
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* Alan Cox : MSS actually. Also added the window
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* clamper.
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* Sam Lantinga : Fixed route matching in rt_del()
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* Alan Cox : Routing cache support.
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* Alan Cox : Removed compatibility cruft.
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* Alan Cox : RTF_REJECT support.
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* Alan Cox : TCP irtt support.
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* Jonathan Naylor : Added Metric support.
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* Miquel van Smoorenburg : BSD API fixes.
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* Miquel van Smoorenburg : Metrics.
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* Alan Cox : Use __u32 properly
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* Alan Cox : Aligned routing errors more closely with BSD
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* our system is still very different.
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* Alan Cox : Faster /proc handling
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* Alexey Kuznetsov : Massive rework to support tree based routing,
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* routing caches and better behaviour.
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*
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* Olaf Erb : irtt wasn't being copied right.
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* Bjorn Ekwall : Kerneld route support.
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* Alan Cox : Multicast fixed (I hope)
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* Pavel Krauz : Limited broadcast fixed
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* Mike McLagan : Routing by source
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* Alexey Kuznetsov : End of old history. Split to fib.c and
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* route.c and rewritten from scratch.
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* Andi Kleen : Load-limit warning messages.
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* Vitaly E. Lavrov : Transparent proxy revived after year coma.
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* Vitaly E. Lavrov : Race condition in ip_route_input_slow.
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* Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
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* Vladimir V. Ivanov : IP rule info (flowid) is really useful.
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* Marc Boucher : routing by fwmark
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* Robert Olsson : Added rt_cache statistics
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* Arnaldo C. Melo : Convert proc stuff to seq_file
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* Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
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* Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
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* Ilia Sotnikov : Removed TOS from hash calculations
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#define pr_fmt(fmt) "IPv4: " fmt
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#include <linux/module.h>
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#include <asm/uaccess.h>
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#include <linux/bitops.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/socket.h>
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#include <linux/sockios.h>
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#include <linux/errno.h>
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#include <linux/in.h>
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#include <linux/inet.h>
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#include <linux/netdevice.h>
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#include <linux/proc_fs.h>
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <linux/inetdevice.h>
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#include <linux/igmp.h>
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#include <linux/pkt_sched.h>
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#include <linux/mroute.h>
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#include <linux/netfilter_ipv4.h>
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#include <linux/random.h>
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#include <linux/rcupdate.h>
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#include <linux/times.h>
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#include <linux/slab.h>
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#include <linux/jhash.h>
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#include <net/dst.h>
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#include <net/dst_metadata.h>
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#include <net/net_namespace.h>
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#include <net/protocol.h>
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#include <net/ip.h>
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#include <net/route.h>
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#include <net/inetpeer.h>
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#include <net/sock.h>
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#include <net/ip_fib.h>
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#include <net/arp.h>
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#include <net/tcp.h>
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#include <net/icmp.h>
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#include <net/xfrm.h>
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#include <net/lwtunnel.h>
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#include <net/netevent.h>
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#include <net/rtnetlink.h>
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#ifdef CONFIG_SYSCTL
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#include <linux/sysctl.h>
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#include <linux/kmemleak.h>
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#endif
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#include <net/secure_seq.h>
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#include <net/ip_tunnels.h>
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#include <net/l3mdev.h>
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#define RT_FL_TOS(oldflp4) \
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((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
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#define RT_GC_TIMEOUT (300*HZ)
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static int ip_rt_max_size;
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static int ip_rt_redirect_number __read_mostly = 9;
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static int ip_rt_redirect_load __read_mostly = HZ / 50;
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static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
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static int ip_rt_error_cost __read_mostly = HZ;
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static int ip_rt_error_burst __read_mostly = 5 * HZ;
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static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
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static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
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static int ip_rt_min_advmss __read_mostly = 256;
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static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
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/*
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* Interface to generic destination cache.
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*/
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static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
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static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
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static unsigned int ipv4_mtu(const struct dst_entry *dst);
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static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
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static void ipv4_link_failure(struct sk_buff *skb);
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static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
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struct sk_buff *skb, u32 mtu);
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static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
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struct sk_buff *skb);
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static void ipv4_dst_destroy(struct dst_entry *dst);
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static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
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{
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WARN_ON(1);
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return NULL;
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}
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static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
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struct sk_buff *skb,
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const void *daddr);
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static struct dst_ops ipv4_dst_ops = {
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.family = AF_INET,
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.check = ipv4_dst_check,
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.default_advmss = ipv4_default_advmss,
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.mtu = ipv4_mtu,
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.cow_metrics = ipv4_cow_metrics,
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.destroy = ipv4_dst_destroy,
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.negative_advice = ipv4_negative_advice,
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.link_failure = ipv4_link_failure,
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.update_pmtu = ip_rt_update_pmtu,
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.redirect = ip_do_redirect,
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.local_out = __ip_local_out,
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.neigh_lookup = ipv4_neigh_lookup,
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};
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#define ECN_OR_COST(class) TC_PRIO_##class
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const __u8 ip_tos2prio[16] = {
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TC_PRIO_BESTEFFORT,
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ECN_OR_COST(BESTEFFORT),
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TC_PRIO_BESTEFFORT,
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ECN_OR_COST(BESTEFFORT),
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TC_PRIO_BULK,
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ECN_OR_COST(BULK),
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TC_PRIO_BULK,
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ECN_OR_COST(BULK),
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TC_PRIO_INTERACTIVE,
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ECN_OR_COST(INTERACTIVE),
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TC_PRIO_INTERACTIVE,
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ECN_OR_COST(INTERACTIVE),
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TC_PRIO_INTERACTIVE_BULK,
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ECN_OR_COST(INTERACTIVE_BULK),
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TC_PRIO_INTERACTIVE_BULK,
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ECN_OR_COST(INTERACTIVE_BULK)
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};
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EXPORT_SYMBOL(ip_tos2prio);
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static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
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#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
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#ifdef CONFIG_PROC_FS
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static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
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{
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if (*pos)
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return NULL;
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return SEQ_START_TOKEN;
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}
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static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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++*pos;
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return NULL;
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}
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static void rt_cache_seq_stop(struct seq_file *seq, void *v)
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{
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}
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static int rt_cache_seq_show(struct seq_file *seq, void *v)
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{
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if (v == SEQ_START_TOKEN)
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seq_printf(seq, "%-127s\n",
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"Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
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"Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
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"HHUptod\tSpecDst");
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return 0;
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}
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static const struct seq_operations rt_cache_seq_ops = {
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.start = rt_cache_seq_start,
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.next = rt_cache_seq_next,
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.stop = rt_cache_seq_stop,
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.show = rt_cache_seq_show,
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};
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static int rt_cache_seq_open(struct inode *inode, struct file *file)
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{
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return seq_open(file, &rt_cache_seq_ops);
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}
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static const struct file_operations rt_cache_seq_fops = {
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.owner = THIS_MODULE,
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.open = rt_cache_seq_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
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{
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int cpu;
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if (*pos == 0)
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return SEQ_START_TOKEN;
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for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
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if (!cpu_possible(cpu))
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continue;
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*pos = cpu+1;
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return &per_cpu(rt_cache_stat, cpu);
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}
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return NULL;
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}
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static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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int cpu;
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for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
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if (!cpu_possible(cpu))
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continue;
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*pos = cpu+1;
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return &per_cpu(rt_cache_stat, cpu);
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}
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return NULL;
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}
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static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
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{
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}
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static int rt_cpu_seq_show(struct seq_file *seq, void *v)
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{
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struct rt_cache_stat *st = v;
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if (v == SEQ_START_TOKEN) {
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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");
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return 0;
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}
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seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
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" %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
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dst_entries_get_slow(&ipv4_dst_ops),
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0, /* st->in_hit */
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st->in_slow_tot,
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st->in_slow_mc,
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st->in_no_route,
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st->in_brd,
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st->in_martian_dst,
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st->in_martian_src,
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0, /* st->out_hit */
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st->out_slow_tot,
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st->out_slow_mc,
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0, /* st->gc_total */
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0, /* st->gc_ignored */
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0, /* st->gc_goal_miss */
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0, /* st->gc_dst_overflow */
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0, /* st->in_hlist_search */
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0 /* st->out_hlist_search */
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);
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return 0;
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}
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static const struct seq_operations rt_cpu_seq_ops = {
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.start = rt_cpu_seq_start,
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.next = rt_cpu_seq_next,
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.stop = rt_cpu_seq_stop,
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.show = rt_cpu_seq_show,
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};
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static int rt_cpu_seq_open(struct inode *inode, struct file *file)
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{
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return seq_open(file, &rt_cpu_seq_ops);
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}
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static const struct file_operations rt_cpu_seq_fops = {
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.owner = THIS_MODULE,
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.open = rt_cpu_seq_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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#ifdef CONFIG_IP_ROUTE_CLASSID
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static int rt_acct_proc_show(struct seq_file *m, void *v)
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{
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struct ip_rt_acct *dst, *src;
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unsigned int i, j;
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dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
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if (!dst)
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return -ENOMEM;
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for_each_possible_cpu(i) {
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src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
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for (j = 0; j < 256; j++) {
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dst[j].o_bytes += src[j].o_bytes;
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dst[j].o_packets += src[j].o_packets;
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dst[j].i_bytes += src[j].i_bytes;
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dst[j].i_packets += src[j].i_packets;
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}
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}
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seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
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kfree(dst);
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return 0;
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}
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static int rt_acct_proc_open(struct inode *inode, struct file *file)
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{
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return single_open(file, rt_acct_proc_show, NULL);
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}
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static const struct file_operations rt_acct_proc_fops = {
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.owner = THIS_MODULE,
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.open = rt_acct_proc_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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#endif
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static int __net_init ip_rt_do_proc_init(struct net *net)
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{
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struct proc_dir_entry *pde;
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pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
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&rt_cache_seq_fops);
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if (!pde)
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goto err1;
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|
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pde = proc_create("rt_cache", S_IRUGO,
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net->proc_net_stat, &rt_cpu_seq_fops);
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if (!pde)
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goto err2;
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|
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#ifdef CONFIG_IP_ROUTE_CLASSID
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pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
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if (!pde)
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goto err3;
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#endif
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return 0;
|
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|
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#ifdef CONFIG_IP_ROUTE_CLASSID
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err3:
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remove_proc_entry("rt_cache", net->proc_net_stat);
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#endif
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err2:
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remove_proc_entry("rt_cache", net->proc_net);
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err1:
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return -ENOMEM;
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}
|
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|
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static void __net_exit ip_rt_do_proc_exit(struct net *net)
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{
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remove_proc_entry("rt_cache", net->proc_net_stat);
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remove_proc_entry("rt_cache", net->proc_net);
|
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#ifdef CONFIG_IP_ROUTE_CLASSID
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remove_proc_entry("rt_acct", net->proc_net);
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#endif
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}
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|
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static struct pernet_operations ip_rt_proc_ops __net_initdata = {
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.init = ip_rt_do_proc_init,
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.exit = ip_rt_do_proc_exit,
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};
|
|
|
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static int __init ip_rt_proc_init(void)
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{
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return register_pernet_subsys(&ip_rt_proc_ops);
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}
|
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|
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#else
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static inline int ip_rt_proc_init(void)
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{
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return 0;
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}
|
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#endif /* CONFIG_PROC_FS */
|
|
|
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static inline bool rt_is_expired(const struct rtable *rth)
|
|
{
|
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return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
|
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}
|
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|
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void rt_cache_flush(struct net *net)
|
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{
|
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rt_genid_bump_ipv4(net);
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}
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|
|
static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
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struct sk_buff *skb,
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const void *daddr)
|
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{
|
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struct net_device *dev = dst->dev;
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const __be32 *pkey = daddr;
|
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const struct rtable *rt;
|
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struct neighbour *n;
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|
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rt = (const struct rtable *) dst;
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if (rt->rt_gateway)
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pkey = (const __be32 *) &rt->rt_gateway;
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else if (skb)
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pkey = &ip_hdr(skb)->daddr;
|
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|
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n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
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if (n)
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return n;
|
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return neigh_create(&arp_tbl, pkey, dev);
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}
|
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|
|
#define IP_IDENTS_SZ 2048u
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|
|
|
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 new, delta = 0;
|
|
|
|
if (old != now && cmpxchg(p_tstamp, old, now) == old)
|
|
delta = prandom_u32_max(now - old);
|
|
|
|
/* Do not use atomic_add_return() as it makes UBSAN unhappy */
|
|
do {
|
|
old = (u32)atomic_read(p_id);
|
|
new = old + delta + segs;
|
|
} while (atomic_cmpxchg(p_id, old, new) != old);
|
|
|
|
return new - segs;
|
|
}
|
|
EXPORT_SYMBOL(ip_idents_reserve);
|
|
|
|
void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
|
|
{
|
|
static u32 ip_idents_hashrnd __read_mostly;
|
|
u32 hash, id;
|
|
|
|
net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
|
|
|
|
hash = jhash_3words((__force u32)iph->daddr,
|
|
(__force u32)iph->saddr,
|
|
iph->protocol ^ net_hash_mix(net),
|
|
ip_idents_hashrnd);
|
|
id = ip_idents_reserve(hash, segs);
|
|
iph->id = htons(id);
|
|
}
|
|
EXPORT_SYMBOL(__ip_select_ident);
|
|
|
|
static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
|
|
const struct iphdr *iph,
|
|
int oif, u8 tos,
|
|
u8 prot, u32 mark, int flow_flags)
|
|
{
|
|
if (sk) {
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
|
|
oif = sk->sk_bound_dev_if;
|
|
mark = sk->sk_mark;
|
|
tos = RT_CONN_FLAGS(sk);
|
|
prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
|
|
}
|
|
flowi4_init_output(fl4, oif, mark, tos,
|
|
RT_SCOPE_UNIVERSE, prot,
|
|
flow_flags,
|
|
iph->daddr, iph->saddr, 0, 0);
|
|
}
|
|
|
|
static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
|
|
const struct sock *sk)
|
|
{
|
|
const struct iphdr *iph = ip_hdr(skb);
|
|
int oif = skb->dev->ifindex;
|
|
u8 tos = RT_TOS(iph->tos);
|
|
u8 prot = iph->protocol;
|
|
u32 mark = skb->mark;
|
|
|
|
__build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
|
|
}
|
|
|
|
static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
|
|
{
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
const struct ip_options_rcu *inet_opt;
|
|
__be32 daddr = inet->inet_daddr;
|
|
|
|
rcu_read_lock();
|
|
inet_opt = rcu_dereference(inet->inet_opt);
|
|
if (inet_opt && inet_opt->opt.srr)
|
|
daddr = inet_opt->opt.faddr;
|
|
flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
|
|
RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
|
|
inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
|
|
inet_sk_flowi_flags(sk),
|
|
daddr, inet->inet_saddr, 0, 0);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
|
|
const struct sk_buff *skb)
|
|
{
|
|
if (skb)
|
|
build_skb_flow_key(fl4, skb, sk);
|
|
else
|
|
build_sk_flow_key(fl4, sk);
|
|
}
|
|
|
|
static inline void rt_free(struct rtable *rt)
|
|
{
|
|
call_rcu(&rt->dst.rcu_head, dst_rcu_free);
|
|
}
|
|
|
|
static DEFINE_SPINLOCK(fnhe_lock);
|
|
|
|
static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
|
|
{
|
|
struct rtable *rt;
|
|
|
|
rt = rcu_dereference(fnhe->fnhe_rth_input);
|
|
if (rt) {
|
|
RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
|
|
rt_free(rt);
|
|
}
|
|
rt = rcu_dereference(fnhe->fnhe_rth_output);
|
|
if (rt) {
|
|
RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
|
|
rt_free(rt);
|
|
}
|
|
}
|
|
|
|
static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
|
|
{
|
|
struct fib_nh_exception *fnhe, *oldest;
|
|
|
|
oldest = rcu_dereference(hash->chain);
|
|
for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
|
|
fnhe = rcu_dereference(fnhe->fnhe_next)) {
|
|
if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
|
|
oldest = fnhe;
|
|
}
|
|
fnhe_flush_routes(oldest);
|
|
return oldest;
|
|
}
|
|
|
|
static inline u32 fnhe_hashfun(__be32 daddr)
|
|
{
|
|
static u32 fnhe_hashrnd __read_mostly;
|
|
u32 hval;
|
|
|
|
net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
|
|
hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
|
|
return hash_32(hval, FNHE_HASH_SHIFT);
|
|
}
|
|
|
|
static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
|
|
{
|
|
rt->rt_pmtu = fnhe->fnhe_pmtu;
|
|
rt->dst.expires = fnhe->fnhe_expires;
|
|
|
|
if (fnhe->fnhe_gw) {
|
|
rt->rt_flags |= RTCF_REDIRECTED;
|
|
rt->rt_gateway = fnhe->fnhe_gw;
|
|
rt->rt_uses_gateway = 1;
|
|
}
|
|
}
|
|
|
|
static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
|
|
u32 pmtu, unsigned long expires)
|
|
{
|
|
struct fnhe_hash_bucket *hash;
|
|
struct fib_nh_exception *fnhe;
|
|
struct rtable *rt;
|
|
unsigned int i;
|
|
int depth;
|
|
u32 hval = fnhe_hashfun(daddr);
|
|
|
|
spin_lock_bh(&fnhe_lock);
|
|
|
|
hash = rcu_dereference(nh->nh_exceptions);
|
|
if (!hash) {
|
|
hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
|
|
if (!hash)
|
|
goto out_unlock;
|
|
rcu_assign_pointer(nh->nh_exceptions, hash);
|
|
}
|
|
|
|
hash += hval;
|
|
|
|
depth = 0;
|
|
for (fnhe = rcu_dereference(hash->chain); fnhe;
|
|
fnhe = rcu_dereference(fnhe->fnhe_next)) {
|
|
if (fnhe->fnhe_daddr == daddr)
|
|
break;
|
|
depth++;
|
|
}
|
|
|
|
if (fnhe) {
|
|
if (gw)
|
|
fnhe->fnhe_gw = gw;
|
|
if (pmtu) {
|
|
fnhe->fnhe_pmtu = pmtu;
|
|
fnhe->fnhe_expires = max(1UL, expires);
|
|
}
|
|
/* Update all cached dsts too */
|
|
rt = rcu_dereference(fnhe->fnhe_rth_input);
|
|
if (rt)
|
|
fill_route_from_fnhe(rt, fnhe);
|
|
rt = rcu_dereference(fnhe->fnhe_rth_output);
|
|
if (rt)
|
|
fill_route_from_fnhe(rt, fnhe);
|
|
} else {
|
|
if (depth > FNHE_RECLAIM_DEPTH)
|
|
fnhe = fnhe_oldest(hash);
|
|
else {
|
|
fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
|
|
if (!fnhe)
|
|
goto out_unlock;
|
|
|
|
fnhe->fnhe_next = hash->chain;
|
|
rcu_assign_pointer(hash->chain, fnhe);
|
|
}
|
|
fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
|
|
fnhe->fnhe_daddr = daddr;
|
|
fnhe->fnhe_gw = gw;
|
|
fnhe->fnhe_pmtu = pmtu;
|
|
fnhe->fnhe_expires = expires;
|
|
|
|
/* Exception created; mark the cached routes for the nexthop
|
|
* stale, so anyone caching it rechecks if this exception
|
|
* applies to them.
|
|
*/
|
|
rt = rcu_dereference(nh->nh_rth_input);
|
|
if (rt)
|
|
rt->dst.obsolete = DST_OBSOLETE_KILL;
|
|
|
|
for_each_possible_cpu(i) {
|
|
struct rtable __rcu **prt;
|
|
prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
|
|
rt = rcu_dereference(*prt);
|
|
if (rt)
|
|
rt->dst.obsolete = DST_OBSOLETE_KILL;
|
|
}
|
|
}
|
|
|
|
fnhe->fnhe_stamp = jiffies;
|
|
|
|
out_unlock:
|
|
spin_unlock_bh(&fnhe_lock);
|
|
}
|
|
|
|
static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
|
|
bool kill_route)
|
|
{
|
|
__be32 new_gw = icmp_hdr(skb)->un.gateway;
|
|
__be32 old_gw = ip_hdr(skb)->saddr;
|
|
struct net_device *dev = skb->dev;
|
|
struct in_device *in_dev;
|
|
struct fib_result res;
|
|
struct neighbour *n;
|
|
struct net *net;
|
|
|
|
switch (icmp_hdr(skb)->code & 7) {
|
|
case ICMP_REDIR_NET:
|
|
case ICMP_REDIR_NETTOS:
|
|
case ICMP_REDIR_HOST:
|
|
case ICMP_REDIR_HOSTTOS:
|
|
break;
|
|
|
|
default:
|
|
return;
|
|
}
|
|
|
|
if (rt->rt_gateway != old_gw)
|
|
return;
|
|
|
|
in_dev = __in_dev_get_rcu(dev);
|
|
if (!in_dev)
|
|
return;
|
|
|
|
net = dev_net(dev);
|
|
if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
|
|
ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
|
|
ipv4_is_zeronet(new_gw))
|
|
goto reject_redirect;
|
|
|
|
if (!IN_DEV_SHARED_MEDIA(in_dev)) {
|
|
if (!inet_addr_onlink(in_dev, new_gw, old_gw))
|
|
goto reject_redirect;
|
|
if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
|
|
goto reject_redirect;
|
|
} else {
|
|
if (inet_addr_type(net, new_gw) != RTN_UNICAST)
|
|
goto reject_redirect;
|
|
}
|
|
|
|
n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
|
|
if (!IS_ERR(n)) {
|
|
if (!(n->nud_state & NUD_VALID)) {
|
|
neigh_event_send(n, NULL);
|
|
} else {
|
|
if (fib_lookup(net, fl4, &res, 0) == 0) {
|
|
struct fib_nh *nh = &FIB_RES_NH(res);
|
|
|
|
update_or_create_fnhe(nh, fl4->daddr, new_gw,
|
|
0, 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;
|
|
int oif = skb->dev->ifindex;
|
|
u8 tos = RT_TOS(iph->tos);
|
|
u8 prot = iph->protocol;
|
|
u32 mark = skb->mark;
|
|
|
|
rt = (struct rtable *) dst;
|
|
|
|
__build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
|
|
__ip_do_redirect(rt, skb, &fl4, true);
|
|
}
|
|
|
|
static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
|
|
{
|
|
struct rtable *rt = (struct rtable *)dst;
|
|
struct dst_entry *ret = dst;
|
|
|
|
if (rt) {
|
|
if (dst->obsolete > 0) {
|
|
ip_rt_put(rt);
|
|
ret = NULL;
|
|
} else if ((rt->rt_flags & RTCF_REDIRECTED) ||
|
|
rt->dst.expires) {
|
|
ip_rt_put(rt);
|
|
ret = NULL;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Algorithm:
|
|
* 1. The first ip_rt_redirect_number redirects are sent
|
|
* with exponential backoff, then we stop sending them at all,
|
|
* assuming that the host ignores our redirects.
|
|
* 2. If we did not see packets requiring redirects
|
|
* during ip_rt_redirect_silence, we assume that the host
|
|
* forgot redirected route and start to send redirects again.
|
|
*
|
|
* This algorithm is much cheaper and more intelligent than dumb load limiting
|
|
* in icmp.c.
|
|
*
|
|
* NOTE. Do not forget to inhibit load limiting for redirects (redundant)
|
|
* and "frag. need" (breaks PMTU discovery) in icmp.c.
|
|
*/
|
|
|
|
void ip_rt_send_redirect(struct sk_buff *skb)
|
|
{
|
|
struct rtable *rt = skb_rtable(skb);
|
|
struct in_device *in_dev;
|
|
struct inet_peer *peer;
|
|
struct net *net;
|
|
int log_martians;
|
|
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;
|
|
|
|
/* Too many ignored redirects; do not send anything
|
|
* set dst.rate_last to the last seen redirected packet.
|
|
*/
|
|
if (peer->rate_tokens >= ip_rt_redirect_number) {
|
|
peer->rate_last = jiffies;
|
|
goto out_put_peer;
|
|
}
|
|
|
|
/* Check for load limit; set rate_last to the latest sent
|
|
* redirect.
|
|
*/
|
|
if (peer->rate_tokens == 0 ||
|
|
time_after(jiffies,
|
|
(peer->rate_last +
|
|
(ip_rt_redirect_load << peer->rate_tokens)))) {
|
|
__be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
|
|
|
|
icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
|
|
peer->rate_last = jiffies;
|
|
++peer->rate_tokens;
|
|
#ifdef CONFIG_IP_ROUTE_VERBOSE
|
|
if (log_martians &&
|
|
peer->rate_tokens == ip_rt_redirect_number)
|
|
net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
|
|
&ip_hdr(skb)->saddr, inet_iif(skb),
|
|
&ip_hdr(skb)->daddr, &gw);
|
|
#endif
|
|
}
|
|
out_put_peer:
|
|
inet_putpeer(peer);
|
|
}
|
|
|
|
static int ip_error(struct sk_buff *skb)
|
|
{
|
|
struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
|
|
struct rtable *rt = skb_rtable(skb);
|
|
struct inet_peer *peer;
|
|
unsigned long now;
|
|
struct net *net;
|
|
bool send;
|
|
int code;
|
|
|
|
/* IP on this device is disabled. */
|
|
if (!in_dev)
|
|
goto out;
|
|
|
|
net = dev_net(rt->dst.dev);
|
|
if (!IN_DEV_FORWARD(in_dev)) {
|
|
switch (rt->dst.error) {
|
|
case EHOSTUNREACH:
|
|
__IP_INC_STATS(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 fib_result res;
|
|
|
|
if (dst_metric_locked(dst, RTAX_MTU))
|
|
return;
|
|
|
|
if (ipv4_mtu(dst) < mtu)
|
|
return;
|
|
|
|
if (mtu < ip_rt_min_pmtu)
|
|
mtu = ip_rt_min_pmtu;
|
|
|
|
if (rt->rt_pmtu == mtu &&
|
|
time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
|
|
return;
|
|
|
|
rcu_read_lock();
|
|
if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
|
|
struct fib_nh *nh = &FIB_RES_NH(res);
|
|
|
|
update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
|
|
jiffies + ip_rt_mtu_expires);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
|
|
struct sk_buff *skb, u32 mtu)
|
|
{
|
|
struct rtable *rt = (struct rtable *) dst;
|
|
struct flowi4 fl4;
|
|
|
|
ip_rt_build_flow_key(&fl4, sk, skb);
|
|
__ip_rt_update_pmtu(rt, &fl4, mtu);
|
|
}
|
|
|
|
void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
|
|
int oif, u32 mark, u8 protocol, int flow_flags)
|
|
{
|
|
const struct iphdr *iph = (const struct iphdr *) skb->data;
|
|
struct flowi4 fl4;
|
|
struct rtable *rt;
|
|
|
|
if (!mark)
|
|
mark = IP4_REPLY_MARK(net, skb->mark);
|
|
|
|
__build_flow_key(&fl4, NULL, iph, oif,
|
|
RT_TOS(iph->tos), protocol, mark, flow_flags);
|
|
rt = __ip_route_output_key(net, &fl4);
|
|
if (!IS_ERR(rt)) {
|
|
__ip_rt_update_pmtu(rt, &fl4, mtu);
|
|
ip_rt_put(rt);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
|
|
|
|
static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
|
|
{
|
|
const struct iphdr *iph = (const struct iphdr *) skb->data;
|
|
struct flowi4 fl4;
|
|
struct rtable *rt;
|
|
|
|
__build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
|
|
|
|
if (!fl4.flowi4_mark)
|
|
fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
|
|
|
|
rt = __ip_route_output_key(sock_net(sk), &fl4);
|
|
if (!IS_ERR(rt)) {
|
|
__ip_rt_update_pmtu(rt, &fl4, mtu);
|
|
ip_rt_put(rt);
|
|
}
|
|
}
|
|
|
|
void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
|
|
{
|
|
const struct iphdr *iph = (const struct iphdr *) skb->data;
|
|
struct flowi4 fl4;
|
|
struct rtable *rt;
|
|
struct dst_entry *odst = NULL;
|
|
bool new = false;
|
|
|
|
bh_lock_sock(sk);
|
|
|
|
if (!ip_sk_accept_pmtu(sk))
|
|
goto out;
|
|
|
|
odst = sk_dst_get(sk);
|
|
|
|
if (sock_owned_by_user(sk) || !odst) {
|
|
__ipv4_sk_update_pmtu(skb, sk, mtu);
|
|
goto out;
|
|
}
|
|
|
|
__build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
|
|
|
|
rt = (struct rtable *)odst;
|
|
if (odst->obsolete && !odst->ops->check(odst, 0)) {
|
|
rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
|
|
if (IS_ERR(rt))
|
|
goto out;
|
|
|
|
new = true;
|
|
}
|
|
|
|
__ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
|
|
|
|
if (!dst_check(&rt->dst, 0)) {
|
|
if (new)
|
|
dst_release(&rt->dst);
|
|
|
|
rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
|
|
if (IS_ERR(rt))
|
|
goto out;
|
|
|
|
new = true;
|
|
}
|
|
|
|
if (new)
|
|
sk_dst_set(sk, &rt->dst);
|
|
|
|
out:
|
|
bh_unlock_sock(sk);
|
|
dst_release(odst);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
|
|
|
|
void ipv4_redirect(struct sk_buff *skb, struct net *net,
|
|
int oif, u32 mark, u8 protocol, int flow_flags)
|
|
{
|
|
const struct iphdr *iph = (const struct iphdr *) skb->data;
|
|
struct flowi4 fl4;
|
|
struct rtable *rt;
|
|
|
|
__build_flow_key(&fl4, NULL, iph, oif,
|
|
RT_TOS(iph->tos), protocol, mark, flow_flags);
|
|
rt = __ip_route_output_key(net, &fl4);
|
|
if (!IS_ERR(rt)) {
|
|
__ip_do_redirect(rt, skb, &fl4, false);
|
|
ip_rt_put(rt);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(ipv4_redirect);
|
|
|
|
void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
|
|
{
|
|
const struct iphdr *iph = (const struct iphdr *) skb->data;
|
|
struct flowi4 fl4;
|
|
struct rtable *rt;
|
|
|
|
__build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
|
|
rt = __ip_route_output_key(sock_net(sk), &fl4);
|
|
if (!IS_ERR(rt)) {
|
|
__ip_do_redirect(rt, skb, &fl4, false);
|
|
ip_rt_put(rt);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
|
|
|
|
static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
|
|
{
|
|
struct rtable *rt = (struct rtable *) dst;
|
|
|
|
/* All IPV4 dsts are created with ->obsolete set to the value
|
|
* DST_OBSOLETE_FORCE_CHK which forces validation calls down
|
|
* into this function always.
|
|
*
|
|
* When a PMTU/redirect information update invalidates a route,
|
|
* this is indicated by setting obsolete to DST_OBSOLETE_KILL or
|
|
* DST_OBSOLETE_DEAD by dst_free().
|
|
*/
|
|
if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
|
|
return NULL;
|
|
return dst;
|
|
}
|
|
|
|
static void ipv4_link_failure(struct sk_buff *skb)
|
|
{
|
|
struct rtable *rt;
|
|
|
|
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
|
|
|
|
rt = skb_rtable(skb);
|
|
if (rt)
|
|
dst_set_expires(&rt->dst, 0);
|
|
}
|
|
|
|
static int ip_rt_bug(struct 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 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
|
|
|
|
if (advmss == 0) {
|
|
advmss = max_t(unsigned int, dst->dev->mtu - 40,
|
|
ip_rt_min_advmss);
|
|
if (advmss > 65535 - 40)
|
|
advmss = 65535 - 40;
|
|
}
|
|
return advmss;
|
|
}
|
|
|
|
static unsigned int ipv4_mtu(const struct dst_entry *dst)
|
|
{
|
|
const struct rtable *rt = (const struct rtable *) dst;
|
|
unsigned int mtu = rt->rt_pmtu;
|
|
|
|
if (!mtu || time_after_eq(jiffies, rt->dst.expires))
|
|
mtu = dst_metric_raw(dst, RTAX_MTU);
|
|
|
|
if (mtu)
|
|
return mtu;
|
|
|
|
mtu = dst->dev->mtu;
|
|
|
|
if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
|
|
if (rt->rt_uses_gateway && mtu > 576)
|
|
mtu = 576;
|
|
}
|
|
|
|
mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
|
|
|
|
return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
|
|
}
|
|
|
|
static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
|
|
{
|
|
struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
|
|
struct fib_nh_exception *fnhe;
|
|
u32 hval;
|
|
|
|
if (!hash)
|
|
return NULL;
|
|
|
|
hval = fnhe_hashfun(daddr);
|
|
|
|
for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
|
|
fnhe = rcu_dereference(fnhe->fnhe_next)) {
|
|
if (fnhe->fnhe_daddr == daddr)
|
|
return fnhe;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
|
|
__be32 daddr)
|
|
{
|
|
bool ret = false;
|
|
|
|
spin_lock_bh(&fnhe_lock);
|
|
|
|
if (daddr == fnhe->fnhe_daddr) {
|
|
struct rtable __rcu **porig;
|
|
struct rtable *orig;
|
|
int genid = fnhe_genid(dev_net(rt->dst.dev));
|
|
|
|
if (rt_is_input_route(rt))
|
|
porig = &fnhe->fnhe_rth_input;
|
|
else
|
|
porig = &fnhe->fnhe_rth_output;
|
|
orig = rcu_dereference(*porig);
|
|
|
|
if (fnhe->fnhe_genid != genid) {
|
|
fnhe->fnhe_genid = genid;
|
|
fnhe->fnhe_gw = 0;
|
|
fnhe->fnhe_pmtu = 0;
|
|
fnhe->fnhe_expires = 0;
|
|
fnhe_flush_routes(fnhe);
|
|
orig = NULL;
|
|
}
|
|
fill_route_from_fnhe(rt, fnhe);
|
|
if (!rt->rt_gateway)
|
|
rt->rt_gateway = daddr;
|
|
|
|
if (!(rt->dst.flags & DST_NOCACHE)) {
|
|
rcu_assign_pointer(*porig, rt);
|
|
if (orig)
|
|
rt_free(orig);
|
|
ret = true;
|
|
}
|
|
|
|
fnhe->fnhe_stamp = jiffies;
|
|
}
|
|
spin_unlock_bh(&fnhe_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
|
|
{
|
|
struct rtable *orig, *prev, **p;
|
|
bool ret = true;
|
|
|
|
if (rt_is_input_route(rt)) {
|
|
p = (struct rtable **)&nh->nh_rth_input;
|
|
} else {
|
|
p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
|
|
}
|
|
orig = *p;
|
|
|
|
prev = cmpxchg(p, orig, rt);
|
|
if (prev == orig) {
|
|
if (orig)
|
|
rt_free(orig);
|
|
} else
|
|
ret = false;
|
|
|
|
return ret;
|
|
}
|
|
|
|
struct uncached_list {
|
|
spinlock_t lock;
|
|
struct list_head head;
|
|
};
|
|
|
|
static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
|
|
|
|
static void rt_add_uncached_list(struct rtable *rt)
|
|
{
|
|
struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
|
|
|
|
rt->rt_uncached_list = ul;
|
|
|
|
spin_lock_bh(&ul->lock);
|
|
list_add_tail(&rt->rt_uncached, &ul->head);
|
|
spin_unlock_bh(&ul->lock);
|
|
}
|
|
|
|
static void ipv4_dst_destroy(struct dst_entry *dst)
|
|
{
|
|
struct rtable *rt = (struct rtable *) dst;
|
|
|
|
if (!list_empty(&rt->rt_uncached)) {
|
|
struct uncached_list *ul = rt->rt_uncached_list;
|
|
|
|
spin_lock_bh(&ul->lock);
|
|
list_del(&rt->rt_uncached);
|
|
spin_unlock_bh(&ul->lock);
|
|
}
|
|
}
|
|
|
|
void rt_flush_dev(struct net_device *dev)
|
|
{
|
|
struct net *net = dev_net(dev);
|
|
struct rtable *rt;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
|
|
|
|
spin_lock_bh(&ul->lock);
|
|
list_for_each_entry(rt, &ul->head, rt_uncached) {
|
|
if (rt->dst.dev != dev)
|
|
continue;
|
|
rt->dst.dev = net->loopback_dev;
|
|
dev_hold(rt->dst.dev);
|
|
dev_put(dev);
|
|
}
|
|
spin_unlock_bh(&ul->lock);
|
|
}
|
|
}
|
|
|
|
static bool rt_cache_valid(const struct rtable *rt)
|
|
{
|
|
return rt &&
|
|
rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
|
|
!rt_is_expired(rt);
|
|
}
|
|
|
|
static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
|
|
const struct fib_result *res,
|
|
struct fib_nh_exception *fnhe,
|
|
struct fib_info *fi, u16 type, u32 itag)
|
|
{
|
|
bool cached = false;
|
|
|
|
if (fi) {
|
|
struct fib_nh *nh = &FIB_RES_NH(*res);
|
|
|
|
if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
|
|
rt->rt_gateway = nh->nh_gw;
|
|
rt->rt_uses_gateway = 1;
|
|
}
|
|
dst_init_metrics(&rt->dst, fi->fib_metrics, true);
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
rt->dst.tclassid = nh->nh_tclassid;
|
|
#endif
|
|
rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
|
|
if (unlikely(fnhe))
|
|
cached = rt_bind_exception(rt, fnhe, daddr);
|
|
else if (!(rt->dst.flags & DST_NOCACHE))
|
|
cached = rt_cache_route(nh, rt);
|
|
if (unlikely(!cached)) {
|
|
/* Routes we intend to cache in nexthop exception or
|
|
* FIB nexthop have the DST_NOCACHE bit clear.
|
|
* However, if we are unsuccessful at storing this
|
|
* route into the cache we really need to set it.
|
|
*/
|
|
rt->dst.flags |= DST_NOCACHE;
|
|
if (!rt->rt_gateway)
|
|
rt->rt_gateway = daddr;
|
|
rt_add_uncached_list(rt);
|
|
}
|
|
} else
|
|
rt_add_uncached_list(rt);
|
|
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
#ifdef CONFIG_IP_MULTIPLE_TABLES
|
|
set_class_tag(rt, res->tclassid);
|
|
#endif
|
|
set_class_tag(rt, itag);
|
|
#endif
|
|
}
|
|
|
|
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 | DST_NOCACHE)) |
|
|
(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_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 */
|
|
static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
|
|
u8 tos, struct net_device *dev, int our)
|
|
{
|
|
struct rtable *rth;
|
|
struct in_device *in_dev = __in_dev_get_rcu(dev);
|
|
unsigned int flags = RTCF_MULTICAST;
|
|
u32 itag = 0;
|
|
int err;
|
|
|
|
/* Primary sanity checks. */
|
|
|
|
if (!in_dev)
|
|
return -EINVAL;
|
|
|
|
if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
|
|
skb->protocol != htons(ETH_P_IP))
|
|
goto e_inval;
|
|
|
|
if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
|
|
goto e_inval;
|
|
|
|
if (ipv4_is_zeronet(saddr)) {
|
|
if (!ipv4_is_local_multicast(daddr))
|
|
goto e_inval;
|
|
} else {
|
|
err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
|
|
in_dev, &itag);
|
|
if (err < 0)
|
|
goto e_err;
|
|
}
|
|
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)
|
|
goto e_nobufs;
|
|
|
|
#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;
|
|
|
|
e_nobufs:
|
|
return -ENOBUFS;
|
|
e_inval:
|
|
return -EINVAL;
|
|
e_err:
|
|
return err;
|
|
}
|
|
|
|
|
|
static void ip_handle_martian_source(struct net_device *dev,
|
|
struct in_device *in_dev,
|
|
struct sk_buff *skb,
|
|
__be32 daddr,
|
|
__be32 saddr)
|
|
{
|
|
RT_CACHE_STAT_INC(in_martian_src);
|
|
#ifdef CONFIG_IP_ROUTE_VERBOSE
|
|
if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
|
|
/*
|
|
* RFC1812 recommendation, if source is martian,
|
|
* the only hint is MAC header.
|
|
*/
|
|
pr_warn("martian source %pI4 from %pI4, on dev %s\n",
|
|
&daddr, &saddr, dev->name);
|
|
if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
|
|
print_hex_dump(KERN_WARNING, "ll header: ",
|
|
DUMP_PREFIX_OFFSET, 16, 1,
|
|
skb_mac_header(skb),
|
|
dev->hard_header_len, true);
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
|
|
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)));
|
|
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);
|
|
}
|
|
|
|
/* 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);
|
|
if (rth && rth->dst.expires &&
|
|
time_after(jiffies, rth->dst.expires)) {
|
|
ip_del_fnhe(&FIB_RES_NH(*res), daddr);
|
|
fnhe = NULL;
|
|
} else {
|
|
goto rt_cache;
|
|
}
|
|
}
|
|
|
|
rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
|
|
|
|
rt_cache:
|
|
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);
|
|
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;
|
|
}
|
|
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 in reverse order.
|
|
*/
|
|
static int ip_multipath_icmp_hash(struct sk_buff *skb)
|
|
{
|
|
const struct iphdr *outer_iph = ip_hdr(skb);
|
|
struct icmphdr _icmph;
|
|
const struct icmphdr *icmph;
|
|
struct iphdr _inner_iph;
|
|
const struct iphdr *inner_iph;
|
|
|
|
if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
|
|
goto standard_hash;
|
|
|
|
icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
|
|
&_icmph);
|
|
if (!icmph)
|
|
goto standard_hash;
|
|
|
|
if (icmph->type != ICMP_DEST_UNREACH &&
|
|
icmph->type != ICMP_REDIRECT &&
|
|
icmph->type != ICMP_TIME_EXCEEDED &&
|
|
icmph->type != ICMP_PARAMETERPROB) {
|
|
goto standard_hash;
|
|
}
|
|
|
|
inner_iph = skb_header_pointer(skb,
|
|
outer_iph->ihl * 4 + sizeof(_icmph),
|
|
sizeof(_inner_iph), &_inner_iph);
|
|
if (!inner_iph)
|
|
goto standard_hash;
|
|
|
|
return fib_multipath_hash(inner_iph->daddr, inner_iph->saddr);
|
|
|
|
standard_hash:
|
|
return fib_multipath_hash(outer_iph->saddr, outer_iph->daddr);
|
|
}
|
|
|
|
#endif /* CONFIG_IP_ROUTE_MULTIPATH */
|
|
|
|
static int ip_mkroute_input(struct sk_buff *skb,
|
|
struct fib_result *res,
|
|
const struct flowi4 *fl4,
|
|
struct in_device *in_dev,
|
|
__be32 daddr, __be32 saddr, u32 tos)
|
|
{
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (res->fi && res->fi->fib_nhs > 1) {
|
|
int h;
|
|
|
|
if (unlikely(ip_hdr(skb)->protocol == IPPROTO_ICMP))
|
|
h = ip_multipath_icmp_hash(skb);
|
|
else
|
|
h = fib_multipath_hash(saddr, daddr);
|
|
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;
|
|
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, &fl4, in_dev, daddr, saddr, tos);
|
|
out: return err;
|
|
|
|
brd_input:
|
|
if (skb->protocol != htons(ETH_P_IP))
|
|
goto e_inval;
|
|
|
|
if (!ipv4_is_zeronet(saddr)) {
|
|
err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
|
|
in_dev, &itag);
|
|
if (err < 0)
|
|
goto martian_source;
|
|
}
|
|
flags |= RTCF_BROADCAST;
|
|
res.type = RTN_BROADCAST;
|
|
RT_CACHE_STAT_INC(in_brd);
|
|
|
|
local_input:
|
|
do_cache = false;
|
|
if (res.fi) {
|
|
if (!itag) {
|
|
rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
|
|
if (rt_cache_valid(rth)) {
|
|
skb_dst_set_noref(skb, &rth->dst);
|
|
err = 0;
|
|
goto out;
|
|
}
|
|
do_cache = true;
|
|
}
|
|
}
|
|
|
|
rth = rt_dst_alloc(net->loopback_dev, 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) {
|
|
if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
|
|
rth->dst.flags |= DST_NOCACHE;
|
|
rt_add_uncached_list(rth);
|
|
}
|
|
}
|
|
skb_dst_set(skb, &rth->dst);
|
|
err = 0;
|
|
goto out;
|
|
|
|
no_route:
|
|
RT_CACHE_STAT_INC(in_no_route);
|
|
res.type = RTN_UNREACHABLE;
|
|
res.fi = NULL;
|
|
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)
|
|
{
|
|
int res;
|
|
|
|
rcu_read_lock();
|
|
|
|
/* Multicast recognition logic is moved from route cache to here.
|
|
The problem was that too many Ethernet cards have broken/missing
|
|
hardware multicast filters :-( As result the host on multicasting
|
|
network acquires a lot of useless route cache entries, sort of
|
|
SDR messages from all the world. Now we try to get rid of them.
|
|
Really, provided software IP multicast filter is organized
|
|
reasonably (at least, hashed), it does not result in a slowdown
|
|
comparing with route cache reject entries.
|
|
Note, that multicast routers are not affected, because
|
|
route cache entry is created eventually.
|
|
*/
|
|
if (ipv4_is_multicast(daddr)) {
|
|
struct in_device *in_dev = __in_dev_get_rcu(dev);
|
|
|
|
if (in_dev) {
|
|
int our = ip_check_mc_rcu(in_dev, daddr, saddr,
|
|
ip_hdr(skb)->protocol);
|
|
if (our
|
|
#ifdef CONFIG_IP_MROUTE
|
|
||
|
|
(!ipv4_is_local_multicast(daddr) &&
|
|
IN_DEV_MFORWARD(in_dev))
|
|
#endif
|
|
) {
|
|
int res = ip_route_input_mc(skb, daddr, saddr,
|
|
tos, dev, our);
|
|
rcu_read_unlock();
|
|
return res;
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
return -EINVAL;
|
|
}
|
|
res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
|
|
rcu_read_unlock();
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(ip_route_input_noref);
|
|
|
|
/* called with rcu_read_lock() */
|
|
static struct rtable *__mkroute_output(const struct fib_result *res,
|
|
const struct flowi4 *fl4, int orig_oif,
|
|
struct net_device *dev_out,
|
|
unsigned int flags)
|
|
{
|
|
struct fib_info *fi = res->fi;
|
|
struct fib_nh_exception *fnhe;
|
|
struct in_device *in_dev;
|
|
u16 type = res->type;
|
|
struct rtable *rth;
|
|
bool do_cache;
|
|
|
|
in_dev = __in_dev_get_rcu(dev_out);
|
|
if (!in_dev)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
|
|
if (ipv4_is_loopback(fl4->saddr) &&
|
|
!(dev_out->flags & IFF_LOOPBACK) &&
|
|
!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.
|
|
*/
|
|
fi = NULL;
|
|
}
|
|
|
|
fnhe = NULL;
|
|
do_cache &= fi != NULL;
|
|
if (do_cache) {
|
|
struct rtable __rcu **prth;
|
|
struct fib_nh *nh = &FIB_RES_NH(*res);
|
|
|
|
fnhe = find_exception(nh, fl4->daddr);
|
|
if (fnhe) {
|
|
prth = &fnhe->fnhe_rth_output;
|
|
rth = rcu_dereference(*prth);
|
|
if (rth && rth->dst.expires &&
|
|
time_after(jiffies, rth->dst.expires)) {
|
|
ip_del_fnhe(nh, fl4->daddr);
|
|
fnhe = NULL;
|
|
} else {
|
|
goto rt_cache;
|
|
}
|
|
}
|
|
|
|
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);
|
|
|
|
rt_cache:
|
|
if (rt_cache_valid(rth)) {
|
|
dst_hold(&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 ? : 0;
|
|
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);
|
|
if (lwtunnel_output_redirect(rth->dst.lwtstate))
|
|
rth->dst.output = lwtunnel_output;
|
|
|
|
return rth;
|
|
}
|
|
|
|
/*
|
|
* Major route resolver routine.
|
|
*/
|
|
|
|
struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
|
|
int mp_hash)
|
|
{
|
|
struct net_device *dev_out = NULL;
|
|
__u8 tos = RT_FL_TOS(fl4);
|
|
unsigned int flags = 0;
|
|
struct fib_result res;
|
|
struct rtable *rth;
|
|
int orig_oif;
|
|
int err = -ENETUNREACH;
|
|
|
|
res.tclassid = 0;
|
|
res.fi = NULL;
|
|
res.table = NULL;
|
|
|
|
orig_oif = fl4->flowi4_oif;
|
|
|
|
fl4->flowi4_iif = LOOPBACK_IFINDEX;
|
|
fl4->flowi4_tos = tos & IPTOS_RT_MASK;
|
|
fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
|
|
RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
|
|
|
|
rcu_read_lock();
|
|
if (fl4->saddr) {
|
|
rth = ERR_PTR(-EINVAL);
|
|
if (ipv4_is_multicast(fl4->saddr) ||
|
|
ipv4_is_lbcast(fl4->saddr) ||
|
|
ipv4_is_zeronet(fl4->saddr))
|
|
goto out;
|
|
|
|
/* I removed check for oif == dev_out->oif here.
|
|
It was wrong for two reasons:
|
|
1. ip_dev_find(net, saddr) can return wrong iface, if saddr
|
|
is assigned to multiple interfaces.
|
|
2. Moreover, we are allowed to send packets with saddr
|
|
of another iface. --ANK
|
|
*/
|
|
|
|
if (fl4->flowi4_oif == 0 &&
|
|
(ipv4_is_multicast(fl4->daddr) ||
|
|
ipv4_is_lbcast(fl4->daddr))) {
|
|
/* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
|
|
dev_out = __ip_dev_find(net, fl4->saddr, false);
|
|
if (!dev_out)
|
|
goto out;
|
|
|
|
/* Special hack: user can direct multicasts
|
|
and limited broadcast via necessary interface
|
|
without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
|
|
This hack is not just for fun, it allows
|
|
vic,vat and friends to work.
|
|
They bind socket to loopback, set ttl to zero
|
|
and expect that it will work.
|
|
From the viewpoint of routing cache they are broken,
|
|
because we are not allowed to build multicast path
|
|
with loopback source addr (look, routing cache
|
|
cannot know, that ttl is zero, so that packet
|
|
will not leave this host and route is valid).
|
|
Luckily, this hack is good workaround.
|
|
*/
|
|
|
|
fl4->flowi4_oif = dev_out->ifindex;
|
|
goto make_route;
|
|
}
|
|
|
|
if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
|
|
/* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
|
|
if (!__ip_dev_find(net, fl4->saddr, false))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
|
|
if (fl4->flowi4_oif) {
|
|
dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
|
|
rth = ERR_PTR(-ENODEV);
|
|
if (!dev_out)
|
|
goto out;
|
|
|
|
/* RACE: Check return value of inet_select_addr instead. */
|
|
if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
|
|
rth = ERR_PTR(-ENETUNREACH);
|
|
goto out;
|
|
}
|
|
if (ipv4_is_local_multicast(fl4->daddr) ||
|
|
ipv4_is_lbcast(fl4->daddr) ||
|
|
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) {
|
|
/* 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(dev_out) ? : net->loopback_dev;
|
|
fl4->flowi4_oif = dev_out->ifindex;
|
|
flags |= RTCF_LOCAL;
|
|
goto make_route;
|
|
}
|
|
|
|
fib_select_path(net, &res, fl4, mp_hash);
|
|
|
|
dev_out = FIB_RES_DEV(res);
|
|
fl4->flowi4_oif = dev_out->ifindex;
|
|
|
|
|
|
make_route:
|
|
rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
|
|
|
|
out:
|
|
rcu_read_unlock();
|
|
return rth;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__ip_route_output_key_hash);
|
|
|
|
static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
|
|
{
|
|
unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
|
|
|
|
return mtu ? : dst->dev->mtu;
|
|
}
|
|
|
|
static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
|
|
struct sk_buff *skb, u32 mtu)
|
|
{
|
|
}
|
|
|
|
static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
|
|
struct sk_buff *skb)
|
|
{
|
|
}
|
|
|
|
static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
|
|
unsigned long old)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static struct dst_ops ipv4_dst_blackhole_ops = {
|
|
.family = AF_INET,
|
|
.check = ipv4_blackhole_dst_check,
|
|
.mtu = ipv4_blackhole_mtu,
|
|
.default_advmss = ipv4_default_advmss,
|
|
.update_pmtu = ipv4_rt_blackhole_update_pmtu,
|
|
.redirect = ipv4_rt_blackhole_redirect,
|
|
.cow_metrics = ipv4_rt_blackhole_cow_metrics,
|
|
.neigh_lookup = ipv4_neigh_lookup,
|
|
};
|
|
|
|
struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
|
|
{
|
|
struct rtable *ort = (struct rtable *) dst_orig;
|
|
struct rtable *rt;
|
|
|
|
rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
|
|
if (rt) {
|
|
struct dst_entry *new = &rt->dst;
|
|
|
|
new->__use = 1;
|
|
new->input = dst_discard;
|
|
new->output = dst_discard_out;
|
|
|
|
new->dev = ort->dst.dev;
|
|
if (new->dev)
|
|
dev_hold(new->dev);
|
|
|
|
rt->rt_is_input = ort->rt_is_input;
|
|
rt->rt_iif = ort->rt_iif;
|
|
rt->rt_pmtu = ort->rt_pmtu;
|
|
|
|
rt->rt_genid = rt_genid_ipv4(net);
|
|
rt->rt_flags = ort->rt_flags;
|
|
rt->rt_type = ort->rt_type;
|
|
rt->rt_gateway = ort->rt_gateway;
|
|
rt->rt_uses_gateway = ort->rt_uses_gateway;
|
|
|
|
INIT_LIST_HEAD(&rt->rt_uncached);
|
|
dst_free(new);
|
|
}
|
|
|
|
dst_release(dst_orig);
|
|
|
|
return rt ? &rt->dst : ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
|
|
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);
|
|
|
|
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, int event, int nowait, unsigned int flags)
|
|
{
|
|
struct rtable *rt = skb_rtable(skb);
|
|
struct rtmsg *r;
|
|
struct nlmsghdr *nlh;
|
|
unsigned long expires = 0;
|
|
u32 error;
|
|
u32 metrics[RTAX_MAX];
|
|
|
|
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
|
|
if (!nlh)
|
|
return -EMSGSIZE;
|
|
|
|
r = nlmsg_data(nlh);
|
|
r->rtm_family = AF_INET;
|
|
r->rtm_dst_len = 32;
|
|
r->rtm_src_len = 0;
|
|
r->rtm_tos = fl4->flowi4_tos;
|
|
r->rtm_table = table_id;
|
|
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 (rtnetlink_put_metrics(skb, metrics) < 0)
|
|
goto nla_put_failure;
|
|
|
|
if (fl4->flowi4_mark &&
|
|
nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
|
|
goto nla_put_failure;
|
|
|
|
error = rt->dst.error;
|
|
|
|
if (rt_is_input_route(rt)) {
|
|
#ifdef CONFIG_IP_MROUTE
|
|
if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
|
|
IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
|
|
int err = ipmr_get_route(net, skb,
|
|
fl4->saddr, fl4->daddr,
|
|
r, nowait, portid);
|
|
|
|
if (err <= 0) {
|
|
if (!nowait) {
|
|
if (err == 0)
|
|
return 0;
|
|
goto nla_put_failure;
|
|
} else {
|
|
if (err == -EMSGSIZE)
|
|
goto nla_put_failure;
|
|
error = err;
|
|
}
|
|
}
|
|
} else
|
|
#endif
|
|
if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
|
|
goto nla_put_failure;
|
|
}
|
|
|
|
if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
|
|
goto nla_put_failure;
|
|
|
|
nlmsg_end(skb, nlh);
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
nlmsg_cancel(skb, nlh);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
|
|
{
|
|
struct net *net = sock_net(in_skb->sk);
|
|
struct rtmsg *rtm;
|
|
struct nlattr *tb[RTA_MAX+1];
|
|
struct rtable *rt = NULL;
|
|
struct flowi4 fl4;
|
|
__be32 dst = 0;
|
|
__be32 src = 0;
|
|
u32 iif;
|
|
int err;
|
|
int mark;
|
|
struct sk_buff *skb;
|
|
u32 table_id = RT_TABLE_MAIN;
|
|
|
|
err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
|
|
if (err < 0)
|
|
goto errout;
|
|
|
|
rtm = nlmsg_data(nlh);
|
|
|
|
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
|
|
if (!skb) {
|
|
err = -ENOBUFS;
|
|
goto errout;
|
|
}
|
|
|
|
/* Reserve room for dummy headers, this skb can pass
|
|
through good chunk of routing engine.
|
|
*/
|
|
skb_reset_mac_header(skb);
|
|
skb_reset_network_header(skb);
|
|
|
|
/* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
|
|
ip_hdr(skb)->protocol = IPPROTO_ICMP;
|
|
skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
|
|
|
|
src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
|
|
dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
|
|
iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
|
|
mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
|
|
|
|
memset(&fl4, 0, sizeof(fl4));
|
|
fl4.daddr = dst;
|
|
fl4.saddr = src;
|
|
fl4.flowi4_tos = rtm->rtm_tos;
|
|
fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
|
|
fl4.flowi4_mark = mark;
|
|
|
|
if (iif) {
|
|
struct net_device *dev;
|
|
|
|
dev = __dev_get_by_index(net, iif);
|
|
if (!dev) {
|
|
err = -ENODEV;
|
|
goto errout_free;
|
|
}
|
|
|
|
skb->protocol = htons(ETH_P_IP);
|
|
skb->dev = dev;
|
|
skb->mark = mark;
|
|
local_bh_disable();
|
|
err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
|
|
local_bh_enable();
|
|
|
|
rt = skb_rtable(skb);
|
|
if (err == 0 && rt->dst.error)
|
|
err = -rt->dst.error;
|
|
} else {
|
|
rt = ip_route_output_key(net, &fl4);
|
|
|
|
err = 0;
|
|
if (IS_ERR(rt))
|
|
err = PTR_ERR(rt);
|
|
}
|
|
|
|
if (err)
|
|
goto errout_free;
|
|
|
|
skb_dst_set(skb, &rt->dst);
|
|
if (rtm->rtm_flags & RTM_F_NOTIFY)
|
|
rt->rt_flags |= RTCF_NOTIFY;
|
|
|
|
if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
|
|
table_id = rt->rt_table_id;
|
|
|
|
err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
|
|
NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
|
|
RTM_NEWROUTE, 0, 0);
|
|
if (err < 0)
|
|
goto errout_free;
|
|
|
|
err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
|
|
errout:
|
|
return err;
|
|
|
|
errout_free:
|
|
kfree_skb(skb);
|
|
goto errout;
|
|
}
|
|
|
|
void ip_rt_multicast_event(struct in_device *in_dev)
|
|
{
|
|
rt_cache_flush(dev_net(in_dev->dev));
|
|
}
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
static int ip_rt_gc_interval __read_mostly = 60 * HZ;
|
|
static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
|
|
static int ip_rt_gc_elasticity __read_mostly = 8;
|
|
|
|
static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
|
|
void __user *buffer,
|
|
size_t *lenp, loff_t *ppos)
|
|
{
|
|
struct net *net = (struct net *)__ctl->extra1;
|
|
|
|
if (write) {
|
|
rt_cache_flush(net);
|
|
fnhe_genid_bump(net);
|
|
return 0;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static struct ctl_table ipv4_route_table[] = {
|
|
{
|
|
.procname = "gc_thresh",
|
|
.data = &ipv4_dst_ops.gc_thresh,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
.procname = "max_size",
|
|
.data = &ip_rt_max_size,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
/* Deprecated. Use gc_min_interval_ms */
|
|
|
|
.procname = "gc_min_interval",
|
|
.data = &ip_rt_gc_min_interval,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_jiffies,
|
|
},
|
|
{
|
|
.procname = "gc_min_interval_ms",
|
|
.data = &ip_rt_gc_min_interval,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_ms_jiffies,
|
|
},
|
|
{
|
|
.procname = "gc_timeout",
|
|
.data = &ip_rt_gc_timeout,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_jiffies,
|
|
},
|
|
{
|
|
.procname = "gc_interval",
|
|
.data = &ip_rt_gc_interval,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_jiffies,
|
|
},
|
|
{
|
|
.procname = "redirect_load",
|
|
.data = &ip_rt_redirect_load,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
.procname = "redirect_number",
|
|
.data = &ip_rt_redirect_number,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
.procname = "redirect_silence",
|
|
.data = &ip_rt_redirect_silence,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
.procname = "error_cost",
|
|
.data = &ip_rt_error_cost,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
.procname = "error_burst",
|
|
.data = &ip_rt_error_burst,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
.procname = "gc_elasticity",
|
|
.data = &ip_rt_gc_elasticity,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
.procname = "mtu_expires",
|
|
.data = &ip_rt_mtu_expires,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_jiffies,
|
|
},
|
|
{
|
|
.procname = "min_pmtu",
|
|
.data = &ip_rt_min_pmtu,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{
|
|
.procname = "min_adv_mss",
|
|
.data = &ip_rt_min_advmss,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{ }
|
|
};
|
|
|
|
static struct ctl_table ipv4_route_flush_table[] = {
|
|
{
|
|
.procname = "flush",
|
|
.maxlen = sizeof(int),
|
|
.mode = 0200,
|
|
.proc_handler = ipv4_sysctl_rtcache_flush,
|
|
},
|
|
{ },
|
|
};
|
|
|
|
static __net_init int sysctl_route_net_init(struct net *net)
|
|
{
|
|
struct ctl_table *tbl;
|
|
|
|
tbl = ipv4_route_flush_table;
|
|
if (!net_eq(net, &init_net)) {
|
|
tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
|
|
if (!tbl)
|
|
goto err_dup;
|
|
|
|
/* Don't export sysctls to unprivileged users */
|
|
if (net->user_ns != &init_user_ns)
|
|
tbl[0].procname = NULL;
|
|
}
|
|
tbl[0].extra1 = net;
|
|
|
|
net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
|
|
if (!net->ipv4.route_hdr)
|
|
goto err_reg;
|
|
return 0;
|
|
|
|
err_reg:
|
|
if (tbl != ipv4_route_flush_table)
|
|
kfree(tbl);
|
|
err_dup:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static __net_exit void sysctl_route_net_exit(struct net *net)
|
|
{
|
|
struct ctl_table *tbl;
|
|
|
|
tbl = net->ipv4.route_hdr->ctl_table_arg;
|
|
unregister_net_sysctl_table(net->ipv4.route_hdr);
|
|
BUG_ON(tbl == ipv4_route_flush_table);
|
|
kfree(tbl);
|
|
}
|
|
|
|
static __net_initdata struct pernet_operations sysctl_route_ops = {
|
|
.init = sysctl_route_net_init,
|
|
.exit = sysctl_route_net_exit,
|
|
};
|
|
#endif
|
|
|
|
static __net_init int rt_genid_init(struct net *net)
|
|
{
|
|
atomic_set(&net->ipv4.rt_genid, 0);
|
|
atomic_set(&net->fnhe_genid, 0);
|
|
get_random_bytes(&net->ipv4.dev_addr_genid,
|
|
sizeof(net->ipv4.dev_addr_genid));
|
|
return 0;
|
|
}
|
|
|
|
static __net_initdata struct pernet_operations rt_genid_ops = {
|
|
.init = rt_genid_init,
|
|
};
|
|
|
|
static int __net_init ipv4_inetpeer_init(struct net *net)
|
|
{
|
|
struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
|
|
|
|
if (!bp)
|
|
return -ENOMEM;
|
|
inet_peer_base_init(bp);
|
|
net->ipv4.peers = bp;
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit ipv4_inetpeer_exit(struct net *net)
|
|
{
|
|
struct inet_peer_base *bp = net->ipv4.peers;
|
|
|
|
net->ipv4.peers = NULL;
|
|
inetpeer_invalidate_tree(bp);
|
|
kfree(bp);
|
|
}
|
|
|
|
static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
|
|
.init = ipv4_inetpeer_init,
|
|
.exit = ipv4_inetpeer_exit,
|
|
};
|
|
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
|
|
#endif /* CONFIG_IP_ROUTE_CLASSID */
|
|
|
|
int __init ip_rt_init(void)
|
|
{
|
|
int rc = 0;
|
|
int cpu;
|
|
|
|
ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
|
|
if (!ip_idents)
|
|
panic("IP: failed to allocate ip_idents\n");
|
|
|
|
prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
|
|
|
|
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, NULL);
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
register_pernet_subsys(&sysctl_route_ops);
|
|
#endif
|
|
register_pernet_subsys(&rt_genid_ops);
|
|
register_pernet_subsys(&ipv4_inetpeer_ops);
|
|
return rc;
|
|
}
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
/*
|
|
* We really need to sanitize the damn ipv4 init order, then all
|
|
* this nonsense will go away.
|
|
*/
|
|
void __init ip_static_sysctl_init(void)
|
|
{
|
|
register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
|
|
}
|
|
#endif
|