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2262 lines
53 KiB
2262 lines
53 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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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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* IPv4 Forwarding Information Base: semantics. |
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* |
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* Authors: Alexey Kuznetsov, <[email protected]> |
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*/ |
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|
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#include <linux/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/jiffies.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/inetdevice.h> |
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#include <linux/netdevice.h> |
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#include <linux/if_arp.h> |
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#include <linux/proc_fs.h> |
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#include <linux/skbuff.h> |
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#include <linux/init.h> |
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#include <linux/slab.h> |
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#include <linux/netlink.h> |
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#include <linux/hash.h> |
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|
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#include <net/arp.h> |
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#include <net/inet_dscp.h> |
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#include <net/ip.h> |
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#include <net/protocol.h> |
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#include <net/route.h> |
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#include <net/tcp.h> |
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#include <net/sock.h> |
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#include <net/ip_fib.h> |
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#include <net/ip6_fib.h> |
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#include <net/nexthop.h> |
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#include <net/netlink.h> |
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#include <net/rtnh.h> |
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#include <net/lwtunnel.h> |
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#include <net/fib_notifier.h> |
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#include <net/addrconf.h> |
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|
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#include "fib_lookup.h" |
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static DEFINE_SPINLOCK(fib_info_lock); |
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static struct hlist_head *fib_info_hash; |
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static struct hlist_head *fib_info_laddrhash; |
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static unsigned int fib_info_hash_size; |
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static unsigned int fib_info_hash_bits; |
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static unsigned int fib_info_cnt; |
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|
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#define DEVINDEX_HASHBITS 8 |
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#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) |
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static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; |
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|
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/* for_nexthops and change_nexthops only used when nexthop object |
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* is not set in a fib_info. The logic within can reference fib_nh. |
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*/ |
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#ifdef CONFIG_IP_ROUTE_MULTIPATH |
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|
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#define for_nexthops(fi) { \ |
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int nhsel; const struct fib_nh *nh; \ |
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for (nhsel = 0, nh = (fi)->fib_nh; \ |
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nhsel < fib_info_num_path((fi)); \ |
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nh++, nhsel++) |
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|
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#define change_nexthops(fi) { \ |
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int nhsel; struct fib_nh *nexthop_nh; \ |
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for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ |
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nhsel < fib_info_num_path((fi)); \ |
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nexthop_nh++, nhsel++) |
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|
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#else /* CONFIG_IP_ROUTE_MULTIPATH */ |
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|
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/* Hope, that gcc will optimize it to get rid of dummy loop */ |
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|
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#define for_nexthops(fi) { \ |
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int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \ |
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for (nhsel = 0; nhsel < 1; nhsel++) |
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|
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#define change_nexthops(fi) { \ |
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int nhsel; \ |
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struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ |
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for (nhsel = 0; nhsel < 1; nhsel++) |
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#endif /* CONFIG_IP_ROUTE_MULTIPATH */ |
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#define endfor_nexthops(fi) } |
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const struct fib_prop fib_props[RTN_MAX + 1] = { |
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[RTN_UNSPEC] = { |
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.error = 0, |
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.scope = RT_SCOPE_NOWHERE, |
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}, |
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[RTN_UNICAST] = { |
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.error = 0, |
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.scope = RT_SCOPE_UNIVERSE, |
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}, |
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[RTN_LOCAL] = { |
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.error = 0, |
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.scope = RT_SCOPE_HOST, |
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}, |
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[RTN_BROADCAST] = { |
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.error = 0, |
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.scope = RT_SCOPE_LINK, |
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}, |
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[RTN_ANYCAST] = { |
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.error = 0, |
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.scope = RT_SCOPE_LINK, |
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}, |
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[RTN_MULTICAST] = { |
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.error = 0, |
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.scope = RT_SCOPE_UNIVERSE, |
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}, |
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[RTN_BLACKHOLE] = { |
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.error = -EINVAL, |
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.scope = RT_SCOPE_UNIVERSE, |
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}, |
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[RTN_UNREACHABLE] = { |
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.error = -EHOSTUNREACH, |
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.scope = RT_SCOPE_UNIVERSE, |
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}, |
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[RTN_PROHIBIT] = { |
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.error = -EACCES, |
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.scope = RT_SCOPE_UNIVERSE, |
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}, |
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[RTN_THROW] = { |
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.error = -EAGAIN, |
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.scope = RT_SCOPE_UNIVERSE, |
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}, |
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[RTN_NAT] = { |
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.error = -EINVAL, |
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.scope = RT_SCOPE_NOWHERE, |
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}, |
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[RTN_XRESOLVE] = { |
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.error = -EINVAL, |
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.scope = RT_SCOPE_NOWHERE, |
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}, |
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}; |
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static void rt_fibinfo_free(struct rtable __rcu **rtp) |
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{ |
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struct rtable *rt = rcu_dereference_protected(*rtp, 1); |
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if (!rt) |
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return; |
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/* Not even needed : RCU_INIT_POINTER(*rtp, NULL); |
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* because we waited an RCU grace period before calling |
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* free_fib_info_rcu() |
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*/ |
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dst_dev_put(&rt->dst); |
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dst_release_immediate(&rt->dst); |
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} |
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static void free_nh_exceptions(struct fib_nh_common *nhc) |
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{ |
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struct fnhe_hash_bucket *hash; |
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int i; |
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hash = rcu_dereference_protected(nhc->nhc_exceptions, 1); |
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if (!hash) |
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return; |
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for (i = 0; i < FNHE_HASH_SIZE; i++) { |
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struct fib_nh_exception *fnhe; |
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|
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fnhe = rcu_dereference_protected(hash[i].chain, 1); |
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while (fnhe) { |
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struct fib_nh_exception *next; |
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next = rcu_dereference_protected(fnhe->fnhe_next, 1); |
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rt_fibinfo_free(&fnhe->fnhe_rth_input); |
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rt_fibinfo_free(&fnhe->fnhe_rth_output); |
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kfree(fnhe); |
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fnhe = next; |
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} |
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} |
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kfree(hash); |
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} |
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static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp) |
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{ |
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int cpu; |
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|
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if (!rtp) |
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return; |
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for_each_possible_cpu(cpu) { |
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struct rtable *rt; |
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rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1); |
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if (rt) { |
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dst_dev_put(&rt->dst); |
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dst_release_immediate(&rt->dst); |
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} |
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} |
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free_percpu(rtp); |
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} |
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void fib_nh_common_release(struct fib_nh_common *nhc) |
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{ |
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netdev_put(nhc->nhc_dev, &nhc->nhc_dev_tracker); |
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lwtstate_put(nhc->nhc_lwtstate); |
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rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output); |
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rt_fibinfo_free(&nhc->nhc_rth_input); |
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free_nh_exceptions(nhc); |
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} |
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EXPORT_SYMBOL_GPL(fib_nh_common_release); |
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void fib_nh_release(struct net *net, struct fib_nh *fib_nh) |
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{ |
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#ifdef CONFIG_IP_ROUTE_CLASSID |
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if (fib_nh->nh_tclassid) |
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atomic_dec(&net->ipv4.fib_num_tclassid_users); |
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#endif |
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fib_nh_common_release(&fib_nh->nh_common); |
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} |
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/* Release a nexthop info record */ |
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static void free_fib_info_rcu(struct rcu_head *head) |
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{ |
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struct fib_info *fi = container_of(head, struct fib_info, rcu); |
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if (fi->nh) { |
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nexthop_put(fi->nh); |
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} else { |
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change_nexthops(fi) { |
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fib_nh_release(fi->fib_net, nexthop_nh); |
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} endfor_nexthops(fi); |
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} |
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ip_fib_metrics_put(fi->fib_metrics); |
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kfree(fi); |
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} |
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void free_fib_info(struct fib_info *fi) |
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{ |
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if (fi->fib_dead == 0) { |
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pr_warn("Freeing alive fib_info %p\n", fi); |
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return; |
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} |
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call_rcu(&fi->rcu, free_fib_info_rcu); |
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} |
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EXPORT_SYMBOL_GPL(free_fib_info); |
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void fib_release_info(struct fib_info *fi) |
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{ |
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spin_lock_bh(&fib_info_lock); |
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if (fi && refcount_dec_and_test(&fi->fib_treeref)) { |
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hlist_del(&fi->fib_hash); |
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/* Paired with READ_ONCE() in fib_create_info(). */ |
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WRITE_ONCE(fib_info_cnt, fib_info_cnt - 1); |
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if (fi->fib_prefsrc) |
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hlist_del(&fi->fib_lhash); |
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if (fi->nh) { |
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list_del(&fi->nh_list); |
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} else { |
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change_nexthops(fi) { |
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if (!nexthop_nh->fib_nh_dev) |
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continue; |
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hlist_del(&nexthop_nh->nh_hash); |
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} endfor_nexthops(fi) |
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} |
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fi->fib_dead = 1; |
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fib_info_put(fi); |
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} |
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spin_unlock_bh(&fib_info_lock); |
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} |
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static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi) |
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{ |
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const struct fib_nh *onh; |
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|
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if (fi->nh || ofi->nh) |
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return nexthop_cmp(fi->nh, ofi->nh) ? 0 : -1; |
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if (ofi->fib_nhs == 0) |
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return 0; |
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for_nexthops(fi) { |
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onh = fib_info_nh(ofi, nhsel); |
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if (nh->fib_nh_oif != onh->fib_nh_oif || |
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nh->fib_nh_gw_family != onh->fib_nh_gw_family || |
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nh->fib_nh_scope != onh->fib_nh_scope || |
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#ifdef CONFIG_IP_ROUTE_MULTIPATH |
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nh->fib_nh_weight != onh->fib_nh_weight || |
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#endif |
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#ifdef CONFIG_IP_ROUTE_CLASSID |
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nh->nh_tclassid != onh->nh_tclassid || |
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#endif |
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lwtunnel_cmp_encap(nh->fib_nh_lws, onh->fib_nh_lws) || |
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((nh->fib_nh_flags ^ onh->fib_nh_flags) & ~RTNH_COMPARE_MASK)) |
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return -1; |
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if (nh->fib_nh_gw_family == AF_INET && |
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nh->fib_nh_gw4 != onh->fib_nh_gw4) |
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return -1; |
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if (nh->fib_nh_gw_family == AF_INET6 && |
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ipv6_addr_cmp(&nh->fib_nh_gw6, &onh->fib_nh_gw6)) |
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return -1; |
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} endfor_nexthops(fi); |
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return 0; |
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} |
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static inline unsigned int fib_devindex_hashfn(unsigned int val) |
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{ |
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return hash_32(val, DEVINDEX_HASHBITS); |
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} |
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static struct hlist_head * |
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fib_info_devhash_bucket(const struct net_device *dev) |
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{ |
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u32 val = net_hash_mix(dev_net(dev)) ^ dev->ifindex; |
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return &fib_info_devhash[fib_devindex_hashfn(val)]; |
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} |
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|
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static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope, |
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u32 prefsrc, u32 priority) |
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{ |
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unsigned int val = init_val; |
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|
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val ^= (protocol << 8) | scope; |
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val ^= prefsrc; |
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val ^= priority; |
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return val; |
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} |
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|
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static unsigned int fib_info_hashfn_result(unsigned int val) |
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{ |
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unsigned int mask = (fib_info_hash_size - 1); |
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|
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return (val ^ (val >> 7) ^ (val >> 12)) & mask; |
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} |
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|
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static inline unsigned int fib_info_hashfn(struct fib_info *fi) |
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{ |
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unsigned int val; |
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|
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val = fib_info_hashfn_1(fi->fib_nhs, fi->fib_protocol, |
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fi->fib_scope, (__force u32)fi->fib_prefsrc, |
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fi->fib_priority); |
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|
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if (fi->nh) { |
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val ^= fib_devindex_hashfn(fi->nh->id); |
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} else { |
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for_nexthops(fi) { |
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val ^= fib_devindex_hashfn(nh->fib_nh_oif); |
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} endfor_nexthops(fi) |
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} |
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return fib_info_hashfn_result(val); |
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} |
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|
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/* no metrics, only nexthop id */ |
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static struct fib_info *fib_find_info_nh(struct net *net, |
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const struct fib_config *cfg) |
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{ |
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struct hlist_head *head; |
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struct fib_info *fi; |
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unsigned int hash; |
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|
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hash = fib_info_hashfn_1(fib_devindex_hashfn(cfg->fc_nh_id), |
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cfg->fc_protocol, cfg->fc_scope, |
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(__force u32)cfg->fc_prefsrc, |
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cfg->fc_priority); |
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hash = fib_info_hashfn_result(hash); |
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head = &fib_info_hash[hash]; |
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|
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hlist_for_each_entry(fi, head, fib_hash) { |
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if (!net_eq(fi->fib_net, net)) |
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continue; |
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if (!fi->nh || fi->nh->id != cfg->fc_nh_id) |
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continue; |
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if (cfg->fc_protocol == fi->fib_protocol && |
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cfg->fc_scope == fi->fib_scope && |
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cfg->fc_prefsrc == fi->fib_prefsrc && |
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cfg->fc_priority == fi->fib_priority && |
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cfg->fc_type == fi->fib_type && |
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cfg->fc_table == fi->fib_tb_id && |
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!((cfg->fc_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK)) |
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return fi; |
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} |
|
|
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return NULL; |
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} |
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|
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static struct fib_info *fib_find_info(struct fib_info *nfi) |
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{ |
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struct hlist_head *head; |
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struct fib_info *fi; |
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unsigned int hash; |
|
|
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hash = fib_info_hashfn(nfi); |
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head = &fib_info_hash[hash]; |
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|
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hlist_for_each_entry(fi, head, fib_hash) { |
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if (!net_eq(fi->fib_net, nfi->fib_net)) |
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continue; |
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if (fi->fib_nhs != nfi->fib_nhs) |
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continue; |
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if (nfi->fib_protocol == fi->fib_protocol && |
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nfi->fib_scope == fi->fib_scope && |
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nfi->fib_prefsrc == fi->fib_prefsrc && |
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nfi->fib_priority == fi->fib_priority && |
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nfi->fib_type == fi->fib_type && |
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memcmp(nfi->fib_metrics, fi->fib_metrics, |
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sizeof(u32) * RTAX_MAX) == 0 && |
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!((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) && |
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nh_comp(fi, nfi) == 0) |
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return fi; |
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} |
|
|
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return NULL; |
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} |
|
|
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/* Check, that the gateway is already configured. |
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* Used only by redirect accept routine. |
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*/ |
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int ip_fib_check_default(__be32 gw, struct net_device *dev) |
|
{ |
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struct hlist_head *head; |
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struct fib_nh *nh; |
|
|
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spin_lock(&fib_info_lock); |
|
|
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head = fib_info_devhash_bucket(dev); |
|
|
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hlist_for_each_entry(nh, head, nh_hash) { |
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if (nh->fib_nh_dev == dev && |
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nh->fib_nh_gw4 == gw && |
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!(nh->fib_nh_flags & RTNH_F_DEAD)) { |
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spin_unlock(&fib_info_lock); |
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return 0; |
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} |
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} |
|
|
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spin_unlock(&fib_info_lock); |
|
|
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return -1; |
|
} |
|
|
|
size_t fib_nlmsg_size(struct fib_info *fi) |
|
{ |
|
size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) |
|
+ nla_total_size(4) /* RTA_TABLE */ |
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+ nla_total_size(4) /* RTA_DST */ |
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+ nla_total_size(4) /* RTA_PRIORITY */ |
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+ nla_total_size(4) /* RTA_PREFSRC */ |
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+ nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */ |
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unsigned int nhs = fib_info_num_path(fi); |
|
|
|
/* space for nested metrics */ |
|
payload += nla_total_size((RTAX_MAX * nla_total_size(4))); |
|
|
|
if (fi->nh) |
|
payload += nla_total_size(4); /* RTA_NH_ID */ |
|
|
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if (nhs) { |
|
size_t nh_encapsize = 0; |
|
/* Also handles the special case nhs == 1 */ |
|
|
|
/* each nexthop is packed in an attribute */ |
|
size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); |
|
unsigned int i; |
|
|
|
/* may contain flow and gateway attribute */ |
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nhsize += 2 * nla_total_size(4); |
|
|
|
/* grab encap info */ |
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for (i = 0; i < fib_info_num_path(fi); i++) { |
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struct fib_nh_common *nhc = fib_info_nhc(fi, i); |
|
|
|
if (nhc->nhc_lwtstate) { |
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/* RTA_ENCAP_TYPE */ |
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nh_encapsize += lwtunnel_get_encap_size( |
|
nhc->nhc_lwtstate); |
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/* RTA_ENCAP */ |
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nh_encapsize += nla_total_size(2); |
|
} |
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} |
|
|
|
/* all nexthops are packed in a nested attribute */ |
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payload += nla_total_size((nhs * nhsize) + nh_encapsize); |
|
|
|
} |
|
|
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return payload; |
|
} |
|
|
|
void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, |
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int dst_len, u32 tb_id, const struct nl_info *info, |
|
unsigned int nlm_flags) |
|
{ |
|
struct fib_rt_info fri; |
|
struct sk_buff *skb; |
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u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
|
int err = -ENOBUFS; |
|
|
|
skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); |
|
if (!skb) |
|
goto errout; |
|
|
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fri.fi = fa->fa_info; |
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fri.tb_id = tb_id; |
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fri.dst = key; |
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fri.dst_len = dst_len; |
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fri.dscp = fa->fa_dscp; |
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fri.type = fa->fa_type; |
|
fri.offload = READ_ONCE(fa->offload); |
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fri.trap = READ_ONCE(fa->trap); |
|
fri.offload_failed = READ_ONCE(fa->offload_failed); |
|
err = fib_dump_info(skb, info->portid, seq, event, &fri, nlm_flags); |
|
if (err < 0) { |
|
/* -EMSGSIZE implies BUG in fib_nlmsg_size() */ |
|
WARN_ON(err == -EMSGSIZE); |
|
kfree_skb(skb); |
|
goto errout; |
|
} |
|
rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE, |
|
info->nlh, GFP_KERNEL); |
|
return; |
|
errout: |
|
if (err < 0) |
|
rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err); |
|
} |
|
|
|
static int fib_detect_death(struct fib_info *fi, int order, |
|
struct fib_info **last_resort, int *last_idx, |
|
int dflt) |
|
{ |
|
const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); |
|
struct neighbour *n; |
|
int state = NUD_NONE; |
|
|
|
if (likely(nhc->nhc_gw_family == AF_INET)) |
|
n = neigh_lookup(&arp_tbl, &nhc->nhc_gw.ipv4, nhc->nhc_dev); |
|
else if (nhc->nhc_gw_family == AF_INET6) |
|
n = neigh_lookup(ipv6_stub->nd_tbl, &nhc->nhc_gw.ipv6, |
|
nhc->nhc_dev); |
|
else |
|
n = NULL; |
|
|
|
if (n) { |
|
state = n->nud_state; |
|
neigh_release(n); |
|
} else { |
|
return 0; |
|
} |
|
if (state == NUD_REACHABLE) |
|
return 0; |
|
if ((state & NUD_VALID) && order != dflt) |
|
return 0; |
|
if ((state & NUD_VALID) || |
|
(*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) { |
|
*last_resort = fi; |
|
*last_idx = order; |
|
} |
|
return 1; |
|
} |
|
|
|
int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc, |
|
struct nlattr *encap, u16 encap_type, |
|
void *cfg, gfp_t gfp_flags, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
int err; |
|
|
|
nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *, |
|
gfp_flags); |
|
if (!nhc->nhc_pcpu_rth_output) |
|
return -ENOMEM; |
|
|
|
if (encap) { |
|
struct lwtunnel_state *lwtstate; |
|
|
|
if (encap_type == LWTUNNEL_ENCAP_NONE) { |
|
NL_SET_ERR_MSG(extack, "LWT encap type not specified"); |
|
err = -EINVAL; |
|
goto lwt_failure; |
|
} |
|
err = lwtunnel_build_state(net, encap_type, encap, |
|
nhc->nhc_family, cfg, &lwtstate, |
|
extack); |
|
if (err) |
|
goto lwt_failure; |
|
|
|
nhc->nhc_lwtstate = lwtstate_get(lwtstate); |
|
} |
|
|
|
return 0; |
|
|
|
lwt_failure: |
|
rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output); |
|
nhc->nhc_pcpu_rth_output = NULL; |
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(fib_nh_common_init); |
|
|
|
int fib_nh_init(struct net *net, struct fib_nh *nh, |
|
struct fib_config *cfg, int nh_weight, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
int err; |
|
|
|
nh->fib_nh_family = AF_INET; |
|
|
|
err = fib_nh_common_init(net, &nh->nh_common, cfg->fc_encap, |
|
cfg->fc_encap_type, cfg, GFP_KERNEL, extack); |
|
if (err) |
|
return err; |
|
|
|
nh->fib_nh_oif = cfg->fc_oif; |
|
nh->fib_nh_gw_family = cfg->fc_gw_family; |
|
if (cfg->fc_gw_family == AF_INET) |
|
nh->fib_nh_gw4 = cfg->fc_gw4; |
|
else if (cfg->fc_gw_family == AF_INET6) |
|
nh->fib_nh_gw6 = cfg->fc_gw6; |
|
|
|
nh->fib_nh_flags = cfg->fc_flags; |
|
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID |
|
nh->nh_tclassid = cfg->fc_flow; |
|
if (nh->nh_tclassid) |
|
atomic_inc(&net->ipv4.fib_num_tclassid_users); |
|
#endif |
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
nh->fib_nh_weight = nh_weight; |
|
#endif |
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
|
|
static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
int nhs = 0; |
|
|
|
while (rtnh_ok(rtnh, remaining)) { |
|
nhs++; |
|
rtnh = rtnh_next(rtnh, &remaining); |
|
} |
|
|
|
/* leftover implies invalid nexthop configuration, discard it */ |
|
if (remaining > 0) { |
|
NL_SET_ERR_MSG(extack, |
|
"Invalid nexthop configuration - extra data after nexthops"); |
|
nhs = 0; |
|
} |
|
|
|
return nhs; |
|
} |
|
|
|
static int fib_gw_from_attr(__be32 *gw, struct nlattr *nla, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
if (nla_len(nla) < sizeof(*gw)) { |
|
NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_GATEWAY"); |
|
return -EINVAL; |
|
} |
|
|
|
*gw = nla_get_in_addr(nla); |
|
|
|
return 0; |
|
} |
|
|
|
/* only called when fib_nh is integrated into fib_info */ |
|
static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
|
int remaining, struct fib_config *cfg, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
struct net *net = fi->fib_net; |
|
struct fib_config fib_cfg; |
|
struct fib_nh *nh; |
|
int ret; |
|
|
|
change_nexthops(fi) { |
|
int attrlen; |
|
|
|
memset(&fib_cfg, 0, sizeof(fib_cfg)); |
|
|
|
if (!rtnh_ok(rtnh, remaining)) { |
|
NL_SET_ERR_MSG(extack, |
|
"Invalid nexthop configuration - extra data after nexthop"); |
|
return -EINVAL; |
|
} |
|
|
|
if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) { |
|
NL_SET_ERR_MSG(extack, |
|
"Invalid flags for nexthop - can not contain DEAD or LINKDOWN"); |
|
return -EINVAL; |
|
} |
|
|
|
fib_cfg.fc_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; |
|
fib_cfg.fc_oif = rtnh->rtnh_ifindex; |
|
|
|
attrlen = rtnh_attrlen(rtnh); |
|
if (attrlen > 0) { |
|
struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh); |
|
|
|
nla = nla_find(attrs, attrlen, RTA_GATEWAY); |
|
nlav = nla_find(attrs, attrlen, RTA_VIA); |
|
if (nla && nlav) { |
|
NL_SET_ERR_MSG(extack, |
|
"Nexthop configuration can not contain both GATEWAY and VIA"); |
|
return -EINVAL; |
|
} |
|
if (nla) { |
|
ret = fib_gw_from_attr(&fib_cfg.fc_gw4, nla, |
|
extack); |
|
if (ret) |
|
goto errout; |
|
|
|
if (fib_cfg.fc_gw4) |
|
fib_cfg.fc_gw_family = AF_INET; |
|
} else if (nlav) { |
|
ret = fib_gw_from_via(&fib_cfg, nlav, extack); |
|
if (ret) |
|
goto errout; |
|
} |
|
|
|
nla = nla_find(attrs, attrlen, RTA_FLOW); |
|
if (nla) { |
|
if (nla_len(nla) < sizeof(u32)) { |
|
NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW"); |
|
return -EINVAL; |
|
} |
|
fib_cfg.fc_flow = nla_get_u32(nla); |
|
} |
|
|
|
fib_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); |
|
/* RTA_ENCAP_TYPE length checked in |
|
* lwtunnel_valid_encap_type_attr |
|
*/ |
|
nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); |
|
if (nla) |
|
fib_cfg.fc_encap_type = nla_get_u16(nla); |
|
} |
|
|
|
ret = fib_nh_init(net, nexthop_nh, &fib_cfg, |
|
rtnh->rtnh_hops + 1, extack); |
|
if (ret) |
|
goto errout; |
|
|
|
rtnh = rtnh_next(rtnh, &remaining); |
|
} endfor_nexthops(fi); |
|
|
|
ret = -EINVAL; |
|
nh = fib_info_nh(fi, 0); |
|
if (cfg->fc_oif && nh->fib_nh_oif != cfg->fc_oif) { |
|
NL_SET_ERR_MSG(extack, |
|
"Nexthop device index does not match RTA_OIF"); |
|
goto errout; |
|
} |
|
if (cfg->fc_gw_family) { |
|
if (cfg->fc_gw_family != nh->fib_nh_gw_family || |
|
(cfg->fc_gw_family == AF_INET && |
|
nh->fib_nh_gw4 != cfg->fc_gw4) || |
|
(cfg->fc_gw_family == AF_INET6 && |
|
ipv6_addr_cmp(&nh->fib_nh_gw6, &cfg->fc_gw6))) { |
|
NL_SET_ERR_MSG(extack, |
|
"Nexthop gateway does not match RTA_GATEWAY or RTA_VIA"); |
|
goto errout; |
|
} |
|
} |
|
#ifdef CONFIG_IP_ROUTE_CLASSID |
|
if (cfg->fc_flow && nh->nh_tclassid != cfg->fc_flow) { |
|
NL_SET_ERR_MSG(extack, |
|
"Nexthop class id does not match RTA_FLOW"); |
|
goto errout; |
|
} |
|
#endif |
|
ret = 0; |
|
errout: |
|
return ret; |
|
} |
|
|
|
/* only called when fib_nh is integrated into fib_info */ |
|
static void fib_rebalance(struct fib_info *fi) |
|
{ |
|
int total; |
|
int w; |
|
|
|
if (fib_info_num_path(fi) < 2) |
|
return; |
|
|
|
total = 0; |
|
for_nexthops(fi) { |
|
if (nh->fib_nh_flags & RTNH_F_DEAD) |
|
continue; |
|
|
|
if (ip_ignore_linkdown(nh->fib_nh_dev) && |
|
nh->fib_nh_flags & RTNH_F_LINKDOWN) |
|
continue; |
|
|
|
total += nh->fib_nh_weight; |
|
} endfor_nexthops(fi); |
|
|
|
w = 0; |
|
change_nexthops(fi) { |
|
int upper_bound; |
|
|
|
if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) { |
|
upper_bound = -1; |
|
} else if (ip_ignore_linkdown(nexthop_nh->fib_nh_dev) && |
|
nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) { |
|
upper_bound = -1; |
|
} else { |
|
w += nexthop_nh->fib_nh_weight; |
|
upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, |
|
total) - 1; |
|
} |
|
|
|
atomic_set(&nexthop_nh->fib_nh_upper_bound, upper_bound); |
|
} endfor_nexthops(fi); |
|
} |
|
#else /* CONFIG_IP_ROUTE_MULTIPATH */ |
|
|
|
static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
|
int remaining, struct fib_config *cfg, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
NL_SET_ERR_MSG(extack, "Multipath support not enabled in kernel"); |
|
|
|
return -EINVAL; |
|
} |
|
|
|
#define fib_rebalance(fi) do { } while (0) |
|
|
|
#endif /* CONFIG_IP_ROUTE_MULTIPATH */ |
|
|
|
static int fib_encap_match(struct net *net, u16 encap_type, |
|
struct nlattr *encap, |
|
const struct fib_nh *nh, |
|
const struct fib_config *cfg, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
struct lwtunnel_state *lwtstate; |
|
int ret, result = 0; |
|
|
|
if (encap_type == LWTUNNEL_ENCAP_NONE) |
|
return 0; |
|
|
|
ret = lwtunnel_build_state(net, encap_type, encap, AF_INET, |
|
cfg, &lwtstate, extack); |
|
if (!ret) { |
|
result = lwtunnel_cmp_encap(lwtstate, nh->fib_nh_lws); |
|
lwtstate_free(lwtstate); |
|
} |
|
|
|
return result; |
|
} |
|
|
|
int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
struct rtnexthop *rtnh; |
|
int remaining; |
|
#endif |
|
|
|
if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
|
return 1; |
|
|
|
if (cfg->fc_nh_id) { |
|
if (fi->nh && cfg->fc_nh_id == fi->nh->id) |
|
return 0; |
|
return 1; |
|
} |
|
|
|
if (cfg->fc_oif || cfg->fc_gw_family) { |
|
struct fib_nh *nh; |
|
|
|
/* cannot match on nexthop object attributes */ |
|
if (fi->nh) |
|
return 1; |
|
|
|
nh = fib_info_nh(fi, 0); |
|
if (cfg->fc_encap) { |
|
if (fib_encap_match(net, cfg->fc_encap_type, |
|
cfg->fc_encap, nh, cfg, extack)) |
|
return 1; |
|
} |
|
#ifdef CONFIG_IP_ROUTE_CLASSID |
|
if (cfg->fc_flow && |
|
cfg->fc_flow != nh->nh_tclassid) |
|
return 1; |
|
#endif |
|
if ((cfg->fc_oif && cfg->fc_oif != nh->fib_nh_oif) || |
|
(cfg->fc_gw_family && |
|
cfg->fc_gw_family != nh->fib_nh_gw_family)) |
|
return 1; |
|
|
|
if (cfg->fc_gw_family == AF_INET && |
|
cfg->fc_gw4 != nh->fib_nh_gw4) |
|
return 1; |
|
|
|
if (cfg->fc_gw_family == AF_INET6 && |
|
ipv6_addr_cmp(&cfg->fc_gw6, &nh->fib_nh_gw6)) |
|
return 1; |
|
|
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
if (!cfg->fc_mp) |
|
return 0; |
|
|
|
rtnh = cfg->fc_mp; |
|
remaining = cfg->fc_mp_len; |
|
|
|
for_nexthops(fi) { |
|
int attrlen; |
|
|
|
if (!rtnh_ok(rtnh, remaining)) |
|
return -EINVAL; |
|
|
|
if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->fib_nh_oif) |
|
return 1; |
|
|
|
attrlen = rtnh_attrlen(rtnh); |
|
if (attrlen > 0) { |
|
struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh); |
|
int err; |
|
|
|
nla = nla_find(attrs, attrlen, RTA_GATEWAY); |
|
nlav = nla_find(attrs, attrlen, RTA_VIA); |
|
if (nla && nlav) { |
|
NL_SET_ERR_MSG(extack, |
|
"Nexthop configuration can not contain both GATEWAY and VIA"); |
|
return -EINVAL; |
|
} |
|
|
|
if (nla) { |
|
__be32 gw; |
|
|
|
err = fib_gw_from_attr(&gw, nla, extack); |
|
if (err) |
|
return err; |
|
|
|
if (nh->fib_nh_gw_family != AF_INET || |
|
gw != nh->fib_nh_gw4) |
|
return 1; |
|
} else if (nlav) { |
|
struct fib_config cfg2; |
|
|
|
err = fib_gw_from_via(&cfg2, nlav, extack); |
|
if (err) |
|
return err; |
|
|
|
switch (nh->fib_nh_gw_family) { |
|
case AF_INET: |
|
if (cfg2.fc_gw_family != AF_INET || |
|
cfg2.fc_gw4 != nh->fib_nh_gw4) |
|
return 1; |
|
break; |
|
case AF_INET6: |
|
if (cfg2.fc_gw_family != AF_INET6 || |
|
ipv6_addr_cmp(&cfg2.fc_gw6, |
|
&nh->fib_nh_gw6)) |
|
return 1; |
|
break; |
|
} |
|
} |
|
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID |
|
nla = nla_find(attrs, attrlen, RTA_FLOW); |
|
if (nla) { |
|
if (nla_len(nla) < sizeof(u32)) { |
|
NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW"); |
|
return -EINVAL; |
|
} |
|
if (nla_get_u32(nla) != nh->nh_tclassid) |
|
return 1; |
|
} |
|
#endif |
|
} |
|
|
|
rtnh = rtnh_next(rtnh, &remaining); |
|
} endfor_nexthops(fi); |
|
#endif |
|
return 0; |
|
} |
|
|
|
bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi) |
|
{ |
|
struct nlattr *nla; |
|
int remaining; |
|
|
|
if (!cfg->fc_mx) |
|
return true; |
|
|
|
nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { |
|
int type = nla_type(nla); |
|
u32 fi_val, val; |
|
|
|
if (!type) |
|
continue; |
|
if (type > RTAX_MAX) |
|
return false; |
|
|
|
if (type == RTAX_CC_ALGO) { |
|
char tmp[TCP_CA_NAME_MAX]; |
|
bool ecn_ca = false; |
|
|
|
nla_strscpy(tmp, nla, sizeof(tmp)); |
|
val = tcp_ca_get_key_by_name(fi->fib_net, tmp, &ecn_ca); |
|
} else { |
|
if (nla_len(nla) != sizeof(u32)) |
|
return false; |
|
val = nla_get_u32(nla); |
|
} |
|
|
|
fi_val = fi->fib_metrics->metrics[type - 1]; |
|
if (type == RTAX_FEATURES) |
|
fi_val &= ~DST_FEATURE_ECN_CA; |
|
|
|
if (fi_val != val) |
|
return false; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
static int fib_check_nh_v6_gw(struct net *net, struct fib_nh *nh, |
|
u32 table, struct netlink_ext_ack *extack) |
|
{ |
|
struct fib6_config cfg = { |
|
.fc_table = table, |
|
.fc_flags = nh->fib_nh_flags | RTF_GATEWAY, |
|
.fc_ifindex = nh->fib_nh_oif, |
|
.fc_gateway = nh->fib_nh_gw6, |
|
}; |
|
struct fib6_nh fib6_nh = {}; |
|
int err; |
|
|
|
err = ipv6_stub->fib6_nh_init(net, &fib6_nh, &cfg, GFP_KERNEL, extack); |
|
if (!err) { |
|
nh->fib_nh_dev = fib6_nh.fib_nh_dev; |
|
netdev_hold(nh->fib_nh_dev, &nh->fib_nh_dev_tracker, |
|
GFP_KERNEL); |
|
nh->fib_nh_oif = nh->fib_nh_dev->ifindex; |
|
nh->fib_nh_scope = RT_SCOPE_LINK; |
|
|
|
ipv6_stub->fib6_nh_release(&fib6_nh); |
|
} |
|
|
|
return err; |
|
} |
|
|
|
/* |
|
* Picture |
|
* ------- |
|
* |
|
* Semantics of nexthop is very messy by historical reasons. |
|
* We have to take into account, that: |
|
* a) gateway can be actually local interface address, |
|
* so that gatewayed route is direct. |
|
* b) gateway must be on-link address, possibly |
|
* described not by an ifaddr, but also by a direct route. |
|
* c) If both gateway and interface are specified, they should not |
|
* contradict. |
|
* d) If we use tunnel routes, gateway could be not on-link. |
|
* |
|
* Attempt to reconcile all of these (alas, self-contradictory) conditions |
|
* results in pretty ugly and hairy code with obscure logic. |
|
* |
|
* I chose to generalized it instead, so that the size |
|
* of code does not increase practically, but it becomes |
|
* much more general. |
|
* Every prefix is assigned a "scope" value: "host" is local address, |
|
* "link" is direct route, |
|
* [ ... "site" ... "interior" ... ] |
|
* and "universe" is true gateway route with global meaning. |
|
* |
|
* Every prefix refers to a set of "nexthop"s (gw, oif), |
|
* where gw must have narrower scope. This recursion stops |
|
* when gw has LOCAL scope or if "nexthop" is declared ONLINK, |
|
* which means that gw is forced to be on link. |
|
* |
|
* Code is still hairy, but now it is apparently logically |
|
* consistent and very flexible. F.e. as by-product it allows |
|
* to co-exists in peace independent exterior and interior |
|
* routing processes. |
|
* |
|
* Normally it looks as following. |
|
* |
|
* {universe prefix} -> (gw, oif) [scope link] |
|
* | |
|
* |-> {link prefix} -> (gw, oif) [scope local] |
|
* | |
|
* |-> {local prefix} (terminal node) |
|
*/ |
|
static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table, |
|
u8 scope, struct netlink_ext_ack *extack) |
|
{ |
|
struct net_device *dev; |
|
struct fib_result res; |
|
int err = 0; |
|
|
|
if (nh->fib_nh_flags & RTNH_F_ONLINK) { |
|
unsigned int addr_type; |
|
|
|
if (scope >= RT_SCOPE_LINK) { |
|
NL_SET_ERR_MSG(extack, "Nexthop has invalid scope"); |
|
return -EINVAL; |
|
} |
|
dev = __dev_get_by_index(net, nh->fib_nh_oif); |
|
if (!dev) { |
|
NL_SET_ERR_MSG(extack, "Nexthop device required for onlink"); |
|
return -ENODEV; |
|
} |
|
if (!(dev->flags & IFF_UP)) { |
|
NL_SET_ERR_MSG(extack, "Nexthop device is not up"); |
|
return -ENETDOWN; |
|
} |
|
addr_type = inet_addr_type_dev_table(net, dev, nh->fib_nh_gw4); |
|
if (addr_type != RTN_UNICAST) { |
|
NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway"); |
|
return -EINVAL; |
|
} |
|
if (!netif_carrier_ok(dev)) |
|
nh->fib_nh_flags |= RTNH_F_LINKDOWN; |
|
nh->fib_nh_dev = dev; |
|
netdev_hold(dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC); |
|
nh->fib_nh_scope = RT_SCOPE_LINK; |
|
return 0; |
|
} |
|
rcu_read_lock(); |
|
{ |
|
struct fib_table *tbl = NULL; |
|
struct flowi4 fl4 = { |
|
.daddr = nh->fib_nh_gw4, |
|
.flowi4_scope = scope + 1, |
|
.flowi4_oif = nh->fib_nh_oif, |
|
.flowi4_iif = LOOPBACK_IFINDEX, |
|
}; |
|
|
|
/* It is not necessary, but requires a bit of thinking */ |
|
if (fl4.flowi4_scope < RT_SCOPE_LINK) |
|
fl4.flowi4_scope = RT_SCOPE_LINK; |
|
|
|
if (table && table != RT_TABLE_MAIN) |
|
tbl = fib_get_table(net, table); |
|
|
|
if (tbl) |
|
err = fib_table_lookup(tbl, &fl4, &res, |
|
FIB_LOOKUP_IGNORE_LINKSTATE | |
|
FIB_LOOKUP_NOREF); |
|
|
|
/* on error or if no table given do full lookup. This |
|
* is needed for example when nexthops are in the local |
|
* table rather than the given table |
|
*/ |
|
if (!tbl || err) { |
|
err = fib_lookup(net, &fl4, &res, |
|
FIB_LOOKUP_IGNORE_LINKSTATE); |
|
} |
|
|
|
if (err) { |
|
NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway"); |
|
goto out; |
|
} |
|
} |
|
|
|
err = -EINVAL; |
|
if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) { |
|
NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway"); |
|
goto out; |
|
} |
|
nh->fib_nh_scope = res.scope; |
|
nh->fib_nh_oif = FIB_RES_OIF(res); |
|
nh->fib_nh_dev = dev = FIB_RES_DEV(res); |
|
if (!dev) { |
|
NL_SET_ERR_MSG(extack, |
|
"No egress device for nexthop gateway"); |
|
goto out; |
|
} |
|
netdev_hold(dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC); |
|
if (!netif_carrier_ok(dev)) |
|
nh->fib_nh_flags |= RTNH_F_LINKDOWN; |
|
err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN; |
|
out: |
|
rcu_read_unlock(); |
|
return err; |
|
} |
|
|
|
static int fib_check_nh_nongw(struct net *net, struct fib_nh *nh, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
struct in_device *in_dev; |
|
int err; |
|
|
|
if (nh->fib_nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) { |
|
NL_SET_ERR_MSG(extack, |
|
"Invalid flags for nexthop - PERVASIVE and ONLINK can not be set"); |
|
return -EINVAL; |
|
} |
|
|
|
rcu_read_lock(); |
|
|
|
err = -ENODEV; |
|
in_dev = inetdev_by_index(net, nh->fib_nh_oif); |
|
if (!in_dev) |
|
goto out; |
|
err = -ENETDOWN; |
|
if (!(in_dev->dev->flags & IFF_UP)) { |
|
NL_SET_ERR_MSG(extack, "Device for nexthop is not up"); |
|
goto out; |
|
} |
|
|
|
nh->fib_nh_dev = in_dev->dev; |
|
netdev_hold(nh->fib_nh_dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC); |
|
nh->fib_nh_scope = RT_SCOPE_LINK; |
|
if (!netif_carrier_ok(nh->fib_nh_dev)) |
|
nh->fib_nh_flags |= RTNH_F_LINKDOWN; |
|
err = 0; |
|
out: |
|
rcu_read_unlock(); |
|
return err; |
|
} |
|
|
|
int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
int err; |
|
|
|
if (nh->fib_nh_gw_family == AF_INET) |
|
err = fib_check_nh_v4_gw(net, nh, table, scope, extack); |
|
else if (nh->fib_nh_gw_family == AF_INET6) |
|
err = fib_check_nh_v6_gw(net, nh, table, extack); |
|
else |
|
err = fib_check_nh_nongw(net, nh, extack); |
|
|
|
return err; |
|
} |
|
|
|
static struct hlist_head * |
|
fib_info_laddrhash_bucket(const struct net *net, __be32 val) |
|
{ |
|
u32 slot = hash_32(net_hash_mix(net) ^ (__force u32)val, |
|
fib_info_hash_bits); |
|
|
|
return &fib_info_laddrhash[slot]; |
|
} |
|
|
|
static void fib_info_hash_move(struct hlist_head *new_info_hash, |
|
struct hlist_head *new_laddrhash, |
|
unsigned int new_size) |
|
{ |
|
struct hlist_head *old_info_hash, *old_laddrhash; |
|
unsigned int old_size = fib_info_hash_size; |
|
unsigned int i; |
|
|
|
spin_lock_bh(&fib_info_lock); |
|
old_info_hash = fib_info_hash; |
|
old_laddrhash = fib_info_laddrhash; |
|
fib_info_hash_size = new_size; |
|
fib_info_hash_bits = ilog2(new_size); |
|
|
|
for (i = 0; i < old_size; i++) { |
|
struct hlist_head *head = &fib_info_hash[i]; |
|
struct hlist_node *n; |
|
struct fib_info *fi; |
|
|
|
hlist_for_each_entry_safe(fi, n, head, fib_hash) { |
|
struct hlist_head *dest; |
|
unsigned int new_hash; |
|
|
|
new_hash = fib_info_hashfn(fi); |
|
dest = &new_info_hash[new_hash]; |
|
hlist_add_head(&fi->fib_hash, dest); |
|
} |
|
} |
|
fib_info_hash = new_info_hash; |
|
|
|
fib_info_laddrhash = new_laddrhash; |
|
for (i = 0; i < old_size; i++) { |
|
struct hlist_head *lhead = &old_laddrhash[i]; |
|
struct hlist_node *n; |
|
struct fib_info *fi; |
|
|
|
hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) { |
|
struct hlist_head *ldest; |
|
|
|
ldest = fib_info_laddrhash_bucket(fi->fib_net, |
|
fi->fib_prefsrc); |
|
hlist_add_head(&fi->fib_lhash, ldest); |
|
} |
|
} |
|
|
|
spin_unlock_bh(&fib_info_lock); |
|
|
|
kvfree(old_info_hash); |
|
kvfree(old_laddrhash); |
|
} |
|
|
|
__be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc, |
|
unsigned char scope) |
|
{ |
|
struct fib_nh *nh; |
|
|
|
if (nhc->nhc_family != AF_INET) |
|
return inet_select_addr(nhc->nhc_dev, 0, scope); |
|
|
|
nh = container_of(nhc, struct fib_nh, nh_common); |
|
nh->nh_saddr = inet_select_addr(nh->fib_nh_dev, nh->fib_nh_gw4, scope); |
|
nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid); |
|
|
|
return nh->nh_saddr; |
|
} |
|
|
|
__be32 fib_result_prefsrc(struct net *net, struct fib_result *res) |
|
{ |
|
struct fib_nh_common *nhc = res->nhc; |
|
|
|
if (res->fi->fib_prefsrc) |
|
return res->fi->fib_prefsrc; |
|
|
|
if (nhc->nhc_family == AF_INET) { |
|
struct fib_nh *nh; |
|
|
|
nh = container_of(nhc, struct fib_nh, nh_common); |
|
if (nh->nh_saddr_genid == atomic_read(&net->ipv4.dev_addr_genid)) |
|
return nh->nh_saddr; |
|
} |
|
|
|
return fib_info_update_nhc_saddr(net, nhc, res->fi->fib_scope); |
|
} |
|
|
|
static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc) |
|
{ |
|
if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || |
|
fib_prefsrc != cfg->fc_dst) { |
|
u32 tb_id = cfg->fc_table; |
|
int rc; |
|
|
|
if (tb_id == RT_TABLE_MAIN) |
|
tb_id = RT_TABLE_LOCAL; |
|
|
|
rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net, |
|
fib_prefsrc, tb_id); |
|
|
|
if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) { |
|
rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net, |
|
fib_prefsrc, RT_TABLE_LOCAL); |
|
} |
|
|
|
if (rc != RTN_LOCAL) |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
struct fib_info *fib_create_info(struct fib_config *cfg, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
int err; |
|
struct fib_info *fi = NULL; |
|
struct nexthop *nh = NULL; |
|
struct fib_info *ofi; |
|
int nhs = 1; |
|
struct net *net = cfg->fc_nlinfo.nl_net; |
|
|
|
if (cfg->fc_type > RTN_MAX) |
|
goto err_inval; |
|
|
|
/* Fast check to catch the most weird cases */ |
|
if (fib_props[cfg->fc_type].scope > cfg->fc_scope) { |
|
NL_SET_ERR_MSG(extack, "Invalid scope"); |
|
goto err_inval; |
|
} |
|
|
|
if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) { |
|
NL_SET_ERR_MSG(extack, |
|
"Invalid rtm_flags - can not contain DEAD or LINKDOWN"); |
|
goto err_inval; |
|
} |
|
|
|
if (cfg->fc_nh_id) { |
|
if (!cfg->fc_mx) { |
|
fi = fib_find_info_nh(net, cfg); |
|
if (fi) { |
|
refcount_inc(&fi->fib_treeref); |
|
return fi; |
|
} |
|
} |
|
|
|
nh = nexthop_find_by_id(net, cfg->fc_nh_id); |
|
if (!nh) { |
|
NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); |
|
goto err_inval; |
|
} |
|
nhs = 0; |
|
} |
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
if (cfg->fc_mp) { |
|
nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len, extack); |
|
if (nhs == 0) |
|
goto err_inval; |
|
} |
|
#endif |
|
|
|
err = -ENOBUFS; |
|
|
|
/* Paired with WRITE_ONCE() in fib_release_info() */ |
|
if (READ_ONCE(fib_info_cnt) >= fib_info_hash_size) { |
|
unsigned int new_size = fib_info_hash_size << 1; |
|
struct hlist_head *new_info_hash; |
|
struct hlist_head *new_laddrhash; |
|
size_t bytes; |
|
|
|
if (!new_size) |
|
new_size = 16; |
|
bytes = (size_t)new_size * sizeof(struct hlist_head *); |
|
new_info_hash = kvzalloc(bytes, GFP_KERNEL); |
|
new_laddrhash = kvzalloc(bytes, GFP_KERNEL); |
|
if (!new_info_hash || !new_laddrhash) { |
|
kvfree(new_info_hash); |
|
kvfree(new_laddrhash); |
|
} else { |
|
fib_info_hash_move(new_info_hash, new_laddrhash, new_size); |
|
} |
|
if (!fib_info_hash_size) |
|
goto failure; |
|
} |
|
|
|
fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL); |
|
if (!fi) |
|
goto failure; |
|
fi->fib_metrics = ip_fib_metrics_init(fi->fib_net, cfg->fc_mx, |
|
cfg->fc_mx_len, extack); |
|
if (IS_ERR(fi->fib_metrics)) { |
|
err = PTR_ERR(fi->fib_metrics); |
|
kfree(fi); |
|
return ERR_PTR(err); |
|
} |
|
|
|
fi->fib_net = net; |
|
fi->fib_protocol = cfg->fc_protocol; |
|
fi->fib_scope = cfg->fc_scope; |
|
fi->fib_flags = cfg->fc_flags; |
|
fi->fib_priority = cfg->fc_priority; |
|
fi->fib_prefsrc = cfg->fc_prefsrc; |
|
fi->fib_type = cfg->fc_type; |
|
fi->fib_tb_id = cfg->fc_table; |
|
|
|
fi->fib_nhs = nhs; |
|
if (nh) { |
|
if (!nexthop_get(nh)) { |
|
NL_SET_ERR_MSG(extack, "Nexthop has been deleted"); |
|
err = -EINVAL; |
|
} else { |
|
err = 0; |
|
fi->nh = nh; |
|
} |
|
} else { |
|
change_nexthops(fi) { |
|
nexthop_nh->nh_parent = fi; |
|
} endfor_nexthops(fi) |
|
|
|
if (cfg->fc_mp) |
|
err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg, |
|
extack); |
|
else |
|
err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack); |
|
} |
|
|
|
if (err != 0) |
|
goto failure; |
|
|
|
if (fib_props[cfg->fc_type].error) { |
|
if (cfg->fc_gw_family || cfg->fc_oif || cfg->fc_mp) { |
|
NL_SET_ERR_MSG(extack, |
|
"Gateway, device and multipath can not be specified for this route type"); |
|
goto err_inval; |
|
} |
|
goto link_it; |
|
} else { |
|
switch (cfg->fc_type) { |
|
case RTN_UNICAST: |
|
case RTN_LOCAL: |
|
case RTN_BROADCAST: |
|
case RTN_ANYCAST: |
|
case RTN_MULTICAST: |
|
break; |
|
default: |
|
NL_SET_ERR_MSG(extack, "Invalid route type"); |
|
goto err_inval; |
|
} |
|
} |
|
|
|
if (cfg->fc_scope > RT_SCOPE_HOST) { |
|
NL_SET_ERR_MSG(extack, "Invalid scope"); |
|
goto err_inval; |
|
} |
|
|
|
if (fi->nh) { |
|
err = fib_check_nexthop(fi->nh, cfg->fc_scope, extack); |
|
if (err) |
|
goto failure; |
|
} else if (cfg->fc_scope == RT_SCOPE_HOST) { |
|
struct fib_nh *nh = fi->fib_nh; |
|
|
|
/* Local address is added. */ |
|
if (nhs != 1) { |
|
NL_SET_ERR_MSG(extack, |
|
"Route with host scope can not have multiple nexthops"); |
|
goto err_inval; |
|
} |
|
if (nh->fib_nh_gw_family) { |
|
NL_SET_ERR_MSG(extack, |
|
"Route with host scope can not have a gateway"); |
|
goto err_inval; |
|
} |
|
nh->fib_nh_scope = RT_SCOPE_NOWHERE; |
|
nh->fib_nh_dev = dev_get_by_index(net, nh->fib_nh_oif); |
|
err = -ENODEV; |
|
if (!nh->fib_nh_dev) |
|
goto failure; |
|
netdev_tracker_alloc(nh->fib_nh_dev, &nh->fib_nh_dev_tracker, |
|
GFP_KERNEL); |
|
} else { |
|
int linkdown = 0; |
|
|
|
change_nexthops(fi) { |
|
err = fib_check_nh(cfg->fc_nlinfo.nl_net, nexthop_nh, |
|
cfg->fc_table, cfg->fc_scope, |
|
extack); |
|
if (err != 0) |
|
goto failure; |
|
if (nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) |
|
linkdown++; |
|
} endfor_nexthops(fi) |
|
if (linkdown == fi->fib_nhs) |
|
fi->fib_flags |= RTNH_F_LINKDOWN; |
|
} |
|
|
|
if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc)) { |
|
NL_SET_ERR_MSG(extack, "Invalid prefsrc address"); |
|
goto err_inval; |
|
} |
|
|
|
if (!fi->nh) { |
|
change_nexthops(fi) { |
|
fib_info_update_nhc_saddr(net, &nexthop_nh->nh_common, |
|
fi->fib_scope); |
|
if (nexthop_nh->fib_nh_gw_family == AF_INET6) |
|
fi->fib_nh_is_v6 = true; |
|
} endfor_nexthops(fi) |
|
|
|
fib_rebalance(fi); |
|
} |
|
|
|
link_it: |
|
ofi = fib_find_info(fi); |
|
if (ofi) { |
|
fi->fib_dead = 1; |
|
free_fib_info(fi); |
|
refcount_inc(&ofi->fib_treeref); |
|
return ofi; |
|
} |
|
|
|
refcount_set(&fi->fib_treeref, 1); |
|
refcount_set(&fi->fib_clntref, 1); |
|
spin_lock_bh(&fib_info_lock); |
|
fib_info_cnt++; |
|
hlist_add_head(&fi->fib_hash, |
|
&fib_info_hash[fib_info_hashfn(fi)]); |
|
if (fi->fib_prefsrc) { |
|
struct hlist_head *head; |
|
|
|
head = fib_info_laddrhash_bucket(net, fi->fib_prefsrc); |
|
hlist_add_head(&fi->fib_lhash, head); |
|
} |
|
if (fi->nh) { |
|
list_add(&fi->nh_list, &nh->fi_list); |
|
} else { |
|
change_nexthops(fi) { |
|
struct hlist_head *head; |
|
|
|
if (!nexthop_nh->fib_nh_dev) |
|
continue; |
|
head = fib_info_devhash_bucket(nexthop_nh->fib_nh_dev); |
|
hlist_add_head(&nexthop_nh->nh_hash, head); |
|
} endfor_nexthops(fi) |
|
} |
|
spin_unlock_bh(&fib_info_lock); |
|
return fi; |
|
|
|
err_inval: |
|
err = -EINVAL; |
|
|
|
failure: |
|
if (fi) { |
|
fi->fib_dead = 1; |
|
free_fib_info(fi); |
|
} |
|
|
|
return ERR_PTR(err); |
|
} |
|
|
|
int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc, |
|
u8 rt_family, unsigned char *flags, bool skip_oif) |
|
{ |
|
if (nhc->nhc_flags & RTNH_F_DEAD) |
|
*flags |= RTNH_F_DEAD; |
|
|
|
if (nhc->nhc_flags & RTNH_F_LINKDOWN) { |
|
*flags |= RTNH_F_LINKDOWN; |
|
|
|
rcu_read_lock(); |
|
switch (nhc->nhc_family) { |
|
case AF_INET: |
|
if (ip_ignore_linkdown(nhc->nhc_dev)) |
|
*flags |= RTNH_F_DEAD; |
|
break; |
|
case AF_INET6: |
|
if (ip6_ignore_linkdown(nhc->nhc_dev)) |
|
*flags |= RTNH_F_DEAD; |
|
break; |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
switch (nhc->nhc_gw_family) { |
|
case AF_INET: |
|
if (nla_put_in_addr(skb, RTA_GATEWAY, nhc->nhc_gw.ipv4)) |
|
goto nla_put_failure; |
|
break; |
|
case AF_INET6: |
|
/* if gateway family does not match nexthop family |
|
* gateway is encoded as RTA_VIA |
|
*/ |
|
if (rt_family != nhc->nhc_gw_family) { |
|
int alen = sizeof(struct in6_addr); |
|
struct nlattr *nla; |
|
struct rtvia *via; |
|
|
|
nla = nla_reserve(skb, RTA_VIA, alen + 2); |
|
if (!nla) |
|
goto nla_put_failure; |
|
|
|
via = nla_data(nla); |
|
via->rtvia_family = AF_INET6; |
|
memcpy(via->rtvia_addr, &nhc->nhc_gw.ipv6, alen); |
|
} else if (nla_put_in6_addr(skb, RTA_GATEWAY, |
|
&nhc->nhc_gw.ipv6) < 0) { |
|
goto nla_put_failure; |
|
} |
|
break; |
|
} |
|
|
|
*flags |= (nhc->nhc_flags & |
|
(RTNH_F_ONLINK | RTNH_F_OFFLOAD | RTNH_F_TRAP)); |
|
|
|
if (!skip_oif && nhc->nhc_dev && |
|
nla_put_u32(skb, RTA_OIF, nhc->nhc_dev->ifindex)) |
|
goto nla_put_failure; |
|
|
|
if (nhc->nhc_lwtstate && |
|
lwtunnel_fill_encap(skb, nhc->nhc_lwtstate, |
|
RTA_ENCAP, RTA_ENCAP_TYPE) < 0) |
|
goto nla_put_failure; |
|
|
|
return 0; |
|
|
|
nla_put_failure: |
|
return -EMSGSIZE; |
|
} |
|
EXPORT_SYMBOL_GPL(fib_nexthop_info); |
|
|
|
#if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6) |
|
int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc, |
|
int nh_weight, u8 rt_family, u32 nh_tclassid) |
|
{ |
|
const struct net_device *dev = nhc->nhc_dev; |
|
struct rtnexthop *rtnh; |
|
unsigned char flags = 0; |
|
|
|
rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); |
|
if (!rtnh) |
|
goto nla_put_failure; |
|
|
|
rtnh->rtnh_hops = nh_weight - 1; |
|
rtnh->rtnh_ifindex = dev ? dev->ifindex : 0; |
|
|
|
if (fib_nexthop_info(skb, nhc, rt_family, &flags, true) < 0) |
|
goto nla_put_failure; |
|
|
|
rtnh->rtnh_flags = flags; |
|
|
|
if (nh_tclassid && nla_put_u32(skb, RTA_FLOW, nh_tclassid)) |
|
goto nla_put_failure; |
|
|
|
/* length of rtnetlink header + attributes */ |
|
rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; |
|
|
|
return 0; |
|
|
|
nla_put_failure: |
|
return -EMSGSIZE; |
|
} |
|
EXPORT_SYMBOL_GPL(fib_add_nexthop); |
|
#endif |
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi) |
|
{ |
|
struct nlattr *mp; |
|
|
|
mp = nla_nest_start_noflag(skb, RTA_MULTIPATH); |
|
if (!mp) |
|
goto nla_put_failure; |
|
|
|
if (unlikely(fi->nh)) { |
|
if (nexthop_mpath_fill_node(skb, fi->nh, AF_INET) < 0) |
|
goto nla_put_failure; |
|
goto mp_end; |
|
} |
|
|
|
for_nexthops(fi) { |
|
u32 nh_tclassid = 0; |
|
#ifdef CONFIG_IP_ROUTE_CLASSID |
|
nh_tclassid = nh->nh_tclassid; |
|
#endif |
|
if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight, |
|
AF_INET, nh_tclassid) < 0) |
|
goto nla_put_failure; |
|
} endfor_nexthops(fi); |
|
|
|
mp_end: |
|
nla_nest_end(skb, mp); |
|
|
|
return 0; |
|
|
|
nla_put_failure: |
|
return -EMSGSIZE; |
|
} |
|
#else |
|
static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi) |
|
{ |
|
return 0; |
|
} |
|
#endif |
|
|
|
int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, |
|
const struct fib_rt_info *fri, unsigned int flags) |
|
{ |
|
unsigned int nhs = fib_info_num_path(fri->fi); |
|
struct fib_info *fi = fri->fi; |
|
u32 tb_id = fri->tb_id; |
|
struct nlmsghdr *nlh; |
|
struct rtmsg *rtm; |
|
|
|
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); |
|
if (!nlh) |
|
return -EMSGSIZE; |
|
|
|
rtm = nlmsg_data(nlh); |
|
rtm->rtm_family = AF_INET; |
|
rtm->rtm_dst_len = fri->dst_len; |
|
rtm->rtm_src_len = 0; |
|
rtm->rtm_tos = inet_dscp_to_dsfield(fri->dscp); |
|
if (tb_id < 256) |
|
rtm->rtm_table = tb_id; |
|
else |
|
rtm->rtm_table = RT_TABLE_COMPAT; |
|
if (nla_put_u32(skb, RTA_TABLE, tb_id)) |
|
goto nla_put_failure; |
|
rtm->rtm_type = fri->type; |
|
rtm->rtm_flags = fi->fib_flags; |
|
rtm->rtm_scope = fi->fib_scope; |
|
rtm->rtm_protocol = fi->fib_protocol; |
|
|
|
if (rtm->rtm_dst_len && |
|
nla_put_in_addr(skb, RTA_DST, fri->dst)) |
|
goto nla_put_failure; |
|
if (fi->fib_priority && |
|
nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority)) |
|
goto nla_put_failure; |
|
if (rtnetlink_put_metrics(skb, fi->fib_metrics->metrics) < 0) |
|
goto nla_put_failure; |
|
|
|
if (fi->fib_prefsrc && |
|
nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc)) |
|
goto nla_put_failure; |
|
|
|
if (fi->nh) { |
|
if (nla_put_u32(skb, RTA_NH_ID, fi->nh->id)) |
|
goto nla_put_failure; |
|
if (nexthop_is_blackhole(fi->nh)) |
|
rtm->rtm_type = RTN_BLACKHOLE; |
|
if (!READ_ONCE(fi->fib_net->ipv4.sysctl_nexthop_compat_mode)) |
|
goto offload; |
|
} |
|
|
|
if (nhs == 1) { |
|
const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); |
|
unsigned char flags = 0; |
|
|
|
if (fib_nexthop_info(skb, nhc, AF_INET, &flags, false) < 0) |
|
goto nla_put_failure; |
|
|
|
rtm->rtm_flags = flags; |
|
#ifdef CONFIG_IP_ROUTE_CLASSID |
|
if (nhc->nhc_family == AF_INET) { |
|
struct fib_nh *nh; |
|
|
|
nh = container_of(nhc, struct fib_nh, nh_common); |
|
if (nh->nh_tclassid && |
|
nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid)) |
|
goto nla_put_failure; |
|
} |
|
#endif |
|
} else { |
|
if (fib_add_multipath(skb, fi) < 0) |
|
goto nla_put_failure; |
|
} |
|
|
|
offload: |
|
if (fri->offload) |
|
rtm->rtm_flags |= RTM_F_OFFLOAD; |
|
if (fri->trap) |
|
rtm->rtm_flags |= RTM_F_TRAP; |
|
if (fri->offload_failed) |
|
rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED; |
|
|
|
nlmsg_end(skb, nlh); |
|
return 0; |
|
|
|
nla_put_failure: |
|
nlmsg_cancel(skb, nlh); |
|
return -EMSGSIZE; |
|
} |
|
|
|
/* |
|
* Update FIB if: |
|
* - local address disappeared -> we must delete all the entries |
|
* referring to it. |
|
* - device went down -> we must shutdown all nexthops going via it. |
|
*/ |
|
int fib_sync_down_addr(struct net_device *dev, __be32 local) |
|
{ |
|
int tb_id = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN; |
|
struct net *net = dev_net(dev); |
|
struct hlist_head *head; |
|
struct fib_info *fi; |
|
int ret = 0; |
|
|
|
if (!fib_info_laddrhash || local == 0) |
|
return 0; |
|
|
|
head = fib_info_laddrhash_bucket(net, local); |
|
hlist_for_each_entry(fi, head, fib_lhash) { |
|
if (!net_eq(fi->fib_net, net) || |
|
fi->fib_tb_id != tb_id) |
|
continue; |
|
if (fi->fib_prefsrc == local) { |
|
fi->fib_flags |= RTNH_F_DEAD; |
|
ret++; |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
static int call_fib_nh_notifiers(struct fib_nh *nh, |
|
enum fib_event_type event_type) |
|
{ |
|
bool ignore_link_down = ip_ignore_linkdown(nh->fib_nh_dev); |
|
struct fib_nh_notifier_info info = { |
|
.fib_nh = nh, |
|
}; |
|
|
|
switch (event_type) { |
|
case FIB_EVENT_NH_ADD: |
|
if (nh->fib_nh_flags & RTNH_F_DEAD) |
|
break; |
|
if (ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) |
|
break; |
|
return call_fib4_notifiers(dev_net(nh->fib_nh_dev), event_type, |
|
&info.info); |
|
case FIB_EVENT_NH_DEL: |
|
if ((ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) || |
|
(nh->fib_nh_flags & RTNH_F_DEAD)) |
|
return call_fib4_notifiers(dev_net(nh->fib_nh_dev), |
|
event_type, &info.info); |
|
break; |
|
default: |
|
break; |
|
} |
|
|
|
return NOTIFY_DONE; |
|
} |
|
|
|
/* Update the PMTU of exceptions when: |
|
* - the new MTU of the first hop becomes smaller than the PMTU |
|
* - the old MTU was the same as the PMTU, and it limited discovery of |
|
* larger MTUs on the path. With that limit raised, we can now |
|
* discover larger MTUs |
|
* A special case is locked exceptions, for which the PMTU is smaller |
|
* than the minimal accepted PMTU: |
|
* - if the new MTU is greater than the PMTU, don't make any change |
|
* - otherwise, unlock and set PMTU |
|
*/ |
|
void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig) |
|
{ |
|
struct fnhe_hash_bucket *bucket; |
|
int i; |
|
|
|
bucket = rcu_dereference_protected(nhc->nhc_exceptions, 1); |
|
if (!bucket) |
|
return; |
|
|
|
for (i = 0; i < FNHE_HASH_SIZE; i++) { |
|
struct fib_nh_exception *fnhe; |
|
|
|
for (fnhe = rcu_dereference_protected(bucket[i].chain, 1); |
|
fnhe; |
|
fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) { |
|
if (fnhe->fnhe_mtu_locked) { |
|
if (new <= fnhe->fnhe_pmtu) { |
|
fnhe->fnhe_pmtu = new; |
|
fnhe->fnhe_mtu_locked = false; |
|
} |
|
} else if (new < fnhe->fnhe_pmtu || |
|
orig == fnhe->fnhe_pmtu) { |
|
fnhe->fnhe_pmtu = new; |
|
} |
|
} |
|
} |
|
} |
|
|
|
void fib_sync_mtu(struct net_device *dev, u32 orig_mtu) |
|
{ |
|
struct hlist_head *head = fib_info_devhash_bucket(dev); |
|
struct fib_nh *nh; |
|
|
|
hlist_for_each_entry(nh, head, nh_hash) { |
|
if (nh->fib_nh_dev == dev) |
|
fib_nhc_update_mtu(&nh->nh_common, dev->mtu, orig_mtu); |
|
} |
|
} |
|
|
|
/* Event force Flags Description |
|
* NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host |
|
* NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host |
|
* NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed |
|
* NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed |
|
* |
|
* only used when fib_nh is built into fib_info |
|
*/ |
|
int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force) |
|
{ |
|
struct hlist_head *head = fib_info_devhash_bucket(dev); |
|
struct fib_info *prev_fi = NULL; |
|
int scope = RT_SCOPE_NOWHERE; |
|
struct fib_nh *nh; |
|
int ret = 0; |
|
|
|
if (force) |
|
scope = -1; |
|
|
|
hlist_for_each_entry(nh, head, nh_hash) { |
|
struct fib_info *fi = nh->nh_parent; |
|
int dead; |
|
|
|
BUG_ON(!fi->fib_nhs); |
|
if (nh->fib_nh_dev != dev || fi == prev_fi) |
|
continue; |
|
prev_fi = fi; |
|
dead = 0; |
|
change_nexthops(fi) { |
|
if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) |
|
dead++; |
|
else if (nexthop_nh->fib_nh_dev == dev && |
|
nexthop_nh->fib_nh_scope != scope) { |
|
switch (event) { |
|
case NETDEV_DOWN: |
|
case NETDEV_UNREGISTER: |
|
nexthop_nh->fib_nh_flags |= RTNH_F_DEAD; |
|
fallthrough; |
|
case NETDEV_CHANGE: |
|
nexthop_nh->fib_nh_flags |= RTNH_F_LINKDOWN; |
|
break; |
|
} |
|
call_fib_nh_notifiers(nexthop_nh, |
|
FIB_EVENT_NH_DEL); |
|
dead++; |
|
} |
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
if (event == NETDEV_UNREGISTER && |
|
nexthop_nh->fib_nh_dev == dev) { |
|
dead = fi->fib_nhs; |
|
break; |
|
} |
|
#endif |
|
} endfor_nexthops(fi) |
|
if (dead == fi->fib_nhs) { |
|
switch (event) { |
|
case NETDEV_DOWN: |
|
case NETDEV_UNREGISTER: |
|
fi->fib_flags |= RTNH_F_DEAD; |
|
fallthrough; |
|
case NETDEV_CHANGE: |
|
fi->fib_flags |= RTNH_F_LINKDOWN; |
|
break; |
|
} |
|
ret++; |
|
} |
|
|
|
fib_rebalance(fi); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/* Must be invoked inside of an RCU protected region. */ |
|
static void fib_select_default(const struct flowi4 *flp, struct fib_result *res) |
|
{ |
|
struct fib_info *fi = NULL, *last_resort = NULL; |
|
struct hlist_head *fa_head = res->fa_head; |
|
struct fib_table *tb = res->table; |
|
u8 slen = 32 - res->prefixlen; |
|
int order = -1, last_idx = -1; |
|
struct fib_alias *fa, *fa1 = NULL; |
|
u32 last_prio = res->fi->fib_priority; |
|
dscp_t last_dscp = 0; |
|
|
|
hlist_for_each_entry_rcu(fa, fa_head, fa_list) { |
|
struct fib_info *next_fi = fa->fa_info; |
|
struct fib_nh_common *nhc; |
|
|
|
if (fa->fa_slen != slen) |
|
continue; |
|
if (fa->fa_dscp && |
|
fa->fa_dscp != inet_dsfield_to_dscp(flp->flowi4_tos)) |
|
continue; |
|
if (fa->tb_id != tb->tb_id) |
|
continue; |
|
if (next_fi->fib_priority > last_prio && |
|
fa->fa_dscp == last_dscp) { |
|
if (last_dscp) |
|
continue; |
|
break; |
|
} |
|
if (next_fi->fib_flags & RTNH_F_DEAD) |
|
continue; |
|
last_dscp = fa->fa_dscp; |
|
last_prio = next_fi->fib_priority; |
|
|
|
if (next_fi->fib_scope != res->scope || |
|
fa->fa_type != RTN_UNICAST) |
|
continue; |
|
|
|
nhc = fib_info_nhc(next_fi, 0); |
|
if (!nhc->nhc_gw_family || nhc->nhc_scope != RT_SCOPE_LINK) |
|
continue; |
|
|
|
fib_alias_accessed(fa); |
|
|
|
if (!fi) { |
|
if (next_fi != res->fi) |
|
break; |
|
fa1 = fa; |
|
} else if (!fib_detect_death(fi, order, &last_resort, |
|
&last_idx, fa1->fa_default)) { |
|
fib_result_assign(res, fi); |
|
fa1->fa_default = order; |
|
goto out; |
|
} |
|
fi = next_fi; |
|
order++; |
|
} |
|
|
|
if (order <= 0 || !fi) { |
|
if (fa1) |
|
fa1->fa_default = -1; |
|
goto out; |
|
} |
|
|
|
if (!fib_detect_death(fi, order, &last_resort, &last_idx, |
|
fa1->fa_default)) { |
|
fib_result_assign(res, fi); |
|
fa1->fa_default = order; |
|
goto out; |
|
} |
|
|
|
if (last_idx >= 0) |
|
fib_result_assign(res, last_resort); |
|
fa1->fa_default = last_idx; |
|
out: |
|
return; |
|
} |
|
|
|
/* |
|
* Dead device goes up. We wake up dead nexthops. |
|
* It takes sense only on multipath routes. |
|
* |
|
* only used when fib_nh is built into fib_info |
|
*/ |
|
int fib_sync_up(struct net_device *dev, unsigned char nh_flags) |
|
{ |
|
struct fib_info *prev_fi; |
|
struct hlist_head *head; |
|
struct fib_nh *nh; |
|
int ret; |
|
|
|
if (!(dev->flags & IFF_UP)) |
|
return 0; |
|
|
|
if (nh_flags & RTNH_F_DEAD) { |
|
unsigned int flags = dev_get_flags(dev); |
|
|
|
if (flags & (IFF_RUNNING | IFF_LOWER_UP)) |
|
nh_flags |= RTNH_F_LINKDOWN; |
|
} |
|
|
|
prev_fi = NULL; |
|
head = fib_info_devhash_bucket(dev); |
|
ret = 0; |
|
|
|
hlist_for_each_entry(nh, head, nh_hash) { |
|
struct fib_info *fi = nh->nh_parent; |
|
int alive; |
|
|
|
BUG_ON(!fi->fib_nhs); |
|
if (nh->fib_nh_dev != dev || fi == prev_fi) |
|
continue; |
|
|
|
prev_fi = fi; |
|
alive = 0; |
|
change_nexthops(fi) { |
|
if (!(nexthop_nh->fib_nh_flags & nh_flags)) { |
|
alive++; |
|
continue; |
|
} |
|
if (!nexthop_nh->fib_nh_dev || |
|
!(nexthop_nh->fib_nh_dev->flags & IFF_UP)) |
|
continue; |
|
if (nexthop_nh->fib_nh_dev != dev || |
|
!__in_dev_get_rtnl(dev)) |
|
continue; |
|
alive++; |
|
nexthop_nh->fib_nh_flags &= ~nh_flags; |
|
call_fib_nh_notifiers(nexthop_nh, FIB_EVENT_NH_ADD); |
|
} endfor_nexthops(fi) |
|
|
|
if (alive > 0) { |
|
fi->fib_flags &= ~nh_flags; |
|
ret++; |
|
} |
|
|
|
fib_rebalance(fi); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
static bool fib_good_nh(const struct fib_nh *nh) |
|
{ |
|
int state = NUD_REACHABLE; |
|
|
|
if (nh->fib_nh_scope == RT_SCOPE_LINK) { |
|
struct neighbour *n; |
|
|
|
rcu_read_lock_bh(); |
|
|
|
if (likely(nh->fib_nh_gw_family == AF_INET)) |
|
n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev, |
|
(__force u32)nh->fib_nh_gw4); |
|
else if (nh->fib_nh_gw_family == AF_INET6) |
|
n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, |
|
&nh->fib_nh_gw6); |
|
else |
|
n = NULL; |
|
if (n) |
|
state = n->nud_state; |
|
|
|
rcu_read_unlock_bh(); |
|
} |
|
|
|
return !!(state & NUD_VALID); |
|
} |
|
|
|
void fib_select_multipath(struct fib_result *res, int hash) |
|
{ |
|
struct fib_info *fi = res->fi; |
|
struct net *net = fi->fib_net; |
|
bool first = false; |
|
|
|
if (unlikely(res->fi->nh)) { |
|
nexthop_path_fib_result(res, hash); |
|
return; |
|
} |
|
|
|
change_nexthops(fi) { |
|
if (READ_ONCE(net->ipv4.sysctl_fib_multipath_use_neigh)) { |
|
if (!fib_good_nh(nexthop_nh)) |
|
continue; |
|
if (!first) { |
|
res->nh_sel = nhsel; |
|
res->nhc = &nexthop_nh->nh_common; |
|
first = true; |
|
} |
|
} |
|
|
|
if (hash > atomic_read(&nexthop_nh->fib_nh_upper_bound)) |
|
continue; |
|
|
|
res->nh_sel = nhsel; |
|
res->nhc = &nexthop_nh->nh_common; |
|
return; |
|
} endfor_nexthops(fi); |
|
} |
|
#endif |
|
|
|
void fib_select_path(struct net *net, struct fib_result *res, |
|
struct flowi4 *fl4, const struct sk_buff *skb) |
|
{ |
|
if (fl4->flowi4_oif) |
|
goto check_saddr; |
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH |
|
if (fib_info_num_path(res->fi) > 1) { |
|
int h = fib_multipath_hash(net, fl4, skb, NULL); |
|
|
|
fib_select_multipath(res, h); |
|
} |
|
else |
|
#endif |
|
if (!res->prefixlen && |
|
res->table->tb_num_default > 1 && |
|
res->type == RTN_UNICAST) |
|
fib_select_default(fl4, res); |
|
|
|
check_saddr: |
|
if (!fl4->saddr) |
|
fl4->saddr = fib_result_prefsrc(net, res); |
|
}
|
|
|