mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-09-04 20:19:47 +08:00
a53110609c
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
546 lines
14 KiB
C
546 lines
14 KiB
C
/* 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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* Definitions for the Forwarding Information Base.
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*
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* Authors: A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*/
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#ifndef _NET_IP_FIB_H
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#define _NET_IP_FIB_H
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#include <net/flow.h>
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#include <linux/seq_file.h>
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#include <linux/rcupdate.h>
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#include <net/fib_notifier.h>
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#include <net/fib_rules.h>
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#include <net/inetpeer.h>
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#include <linux/percpu.h>
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#include <linux/notifier.h>
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#include <linux/refcount.h>
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struct fib_config {
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u8 fc_dst_len;
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u8 fc_tos;
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u8 fc_protocol;
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u8 fc_scope;
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u8 fc_type;
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u8 fc_gw_family;
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/* 2 bytes unused */
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u32 fc_table;
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__be32 fc_dst;
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union {
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__be32 fc_gw4;
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struct in6_addr fc_gw6;
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};
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int fc_oif;
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u32 fc_flags;
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u32 fc_priority;
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__be32 fc_prefsrc;
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u32 fc_nh_id;
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struct nlattr *fc_mx;
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struct rtnexthop *fc_mp;
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int fc_mx_len;
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int fc_mp_len;
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u32 fc_flow;
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u32 fc_nlflags;
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struct nl_info fc_nlinfo;
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struct nlattr *fc_encap;
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u16 fc_encap_type;
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};
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struct fib_info;
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struct rtable;
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struct fib_nh_exception {
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struct fib_nh_exception __rcu *fnhe_next;
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int fnhe_genid;
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__be32 fnhe_daddr;
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u32 fnhe_pmtu;
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bool fnhe_mtu_locked;
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__be32 fnhe_gw;
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unsigned long fnhe_expires;
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struct rtable __rcu *fnhe_rth_input;
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struct rtable __rcu *fnhe_rth_output;
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unsigned long fnhe_stamp;
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struct rcu_head rcu;
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};
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struct fnhe_hash_bucket {
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struct fib_nh_exception __rcu *chain;
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};
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#define FNHE_HASH_SHIFT 11
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#define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT)
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#define FNHE_RECLAIM_DEPTH 5
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struct fib_nh_common {
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struct net_device *nhc_dev;
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int nhc_oif;
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unsigned char nhc_scope;
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u8 nhc_family;
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u8 nhc_gw_family;
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unsigned char nhc_flags;
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struct lwtunnel_state *nhc_lwtstate;
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union {
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__be32 ipv4;
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struct in6_addr ipv6;
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} nhc_gw;
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int nhc_weight;
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atomic_t nhc_upper_bound;
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/* v4 specific, but allows fib6_nh with v4 routes */
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struct rtable __rcu * __percpu *nhc_pcpu_rth_output;
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struct rtable __rcu *nhc_rth_input;
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struct fnhe_hash_bucket __rcu *nhc_exceptions;
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};
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struct fib_nh {
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struct fib_nh_common nh_common;
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struct hlist_node nh_hash;
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struct fib_info *nh_parent;
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#ifdef CONFIG_IP_ROUTE_CLASSID
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__u32 nh_tclassid;
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#endif
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__be32 nh_saddr;
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int nh_saddr_genid;
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#define fib_nh_family nh_common.nhc_family
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#define fib_nh_dev nh_common.nhc_dev
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#define fib_nh_oif nh_common.nhc_oif
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#define fib_nh_flags nh_common.nhc_flags
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#define fib_nh_lws nh_common.nhc_lwtstate
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#define fib_nh_scope nh_common.nhc_scope
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#define fib_nh_gw_family nh_common.nhc_gw_family
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#define fib_nh_gw4 nh_common.nhc_gw.ipv4
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#define fib_nh_gw6 nh_common.nhc_gw.ipv6
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#define fib_nh_weight nh_common.nhc_weight
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#define fib_nh_upper_bound nh_common.nhc_upper_bound
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};
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/*
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* This structure contains data shared by many of routes.
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*/
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struct nexthop;
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struct fib_info {
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struct hlist_node fib_hash;
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struct hlist_node fib_lhash;
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struct list_head nh_list;
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struct net *fib_net;
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int fib_treeref;
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refcount_t fib_clntref;
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unsigned int fib_flags;
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unsigned char fib_dead;
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unsigned char fib_protocol;
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unsigned char fib_scope;
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unsigned char fib_type;
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__be32 fib_prefsrc;
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u32 fib_tb_id;
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u32 fib_priority;
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struct dst_metrics *fib_metrics;
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#define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
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#define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
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#define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
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#define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
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int fib_nhs;
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bool fib_nh_is_v6;
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bool nh_updated;
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struct nexthop *nh;
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struct rcu_head rcu;
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struct fib_nh fib_nh[];
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};
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#ifdef CONFIG_IP_MULTIPLE_TABLES
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struct fib_rule;
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#endif
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struct fib_table;
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struct fib_result {
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__be32 prefix;
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unsigned char prefixlen;
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unsigned char nh_sel;
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unsigned char type;
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unsigned char scope;
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u32 tclassid;
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struct fib_nh_common *nhc;
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struct fib_info *fi;
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struct fib_table *table;
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struct hlist_head *fa_head;
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};
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struct fib_result_nl {
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__be32 fl_addr; /* To be looked up*/
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u32 fl_mark;
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unsigned char fl_tos;
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unsigned char fl_scope;
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unsigned char tb_id_in;
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unsigned char tb_id; /* Results */
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unsigned char prefixlen;
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unsigned char nh_sel;
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unsigned char type;
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unsigned char scope;
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int err;
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};
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#ifdef CONFIG_IP_MULTIPLE_TABLES
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#define FIB_TABLE_HASHSZ 256
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#else
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#define FIB_TABLE_HASHSZ 2
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#endif
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__be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
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unsigned char scope);
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__be32 fib_result_prefsrc(struct net *net, struct fib_result *res);
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#define FIB_RES_NHC(res) ((res).nhc)
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#define FIB_RES_DEV(res) (FIB_RES_NHC(res)->nhc_dev)
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#define FIB_RES_OIF(res) (FIB_RES_NHC(res)->nhc_oif)
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struct fib_rt_info {
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struct fib_info *fi;
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u32 tb_id;
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__be32 dst;
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int dst_len;
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u8 tos;
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u8 type;
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u8 offload:1,
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trap:1,
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unused:6;
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};
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struct fib_entry_notifier_info {
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struct fib_notifier_info info; /* must be first */
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u32 dst;
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int dst_len;
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struct fib_info *fi;
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u8 tos;
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u8 type;
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u32 tb_id;
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};
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struct fib_nh_notifier_info {
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struct fib_notifier_info info; /* must be first */
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struct fib_nh *fib_nh;
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};
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int call_fib4_notifier(struct notifier_block *nb,
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enum fib_event_type event_type,
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struct fib_notifier_info *info);
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int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
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struct fib_notifier_info *info);
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int __net_init fib4_notifier_init(struct net *net);
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void __net_exit fib4_notifier_exit(struct net *net);
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void fib_info_notify_update(struct net *net, struct nl_info *info);
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int fib_notify(struct net *net, struct notifier_block *nb,
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struct netlink_ext_ack *extack);
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struct fib_table {
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struct hlist_node tb_hlist;
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u32 tb_id;
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int tb_num_default;
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struct rcu_head rcu;
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unsigned long *tb_data;
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unsigned long __data[];
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};
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struct fib_dump_filter {
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u32 table_id;
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/* filter_set is an optimization that an entry is set */
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bool filter_set;
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bool dump_all_families;
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bool dump_routes;
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bool dump_exceptions;
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unsigned char protocol;
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unsigned char rt_type;
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unsigned int flags;
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struct net_device *dev;
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};
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int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
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struct fib_result *res, int fib_flags);
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int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
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struct netlink_ext_ack *extack);
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int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
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struct netlink_ext_ack *extack);
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int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
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struct netlink_callback *cb, struct fib_dump_filter *filter);
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int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all);
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struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
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void fib_table_flush_external(struct fib_table *table);
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void fib_free_table(struct fib_table *tb);
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#ifndef CONFIG_IP_MULTIPLE_TABLES
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#define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
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#define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
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static inline struct fib_table *fib_get_table(struct net *net, u32 id)
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{
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struct hlist_node *tb_hlist;
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struct hlist_head *ptr;
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ptr = id == RT_TABLE_LOCAL ?
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&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
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&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
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tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
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return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
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}
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static inline struct fib_table *fib_new_table(struct net *net, u32 id)
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{
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return fib_get_table(net, id);
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}
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static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
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struct fib_result *res, unsigned int flags)
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{
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struct fib_table *tb;
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int err = -ENETUNREACH;
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rcu_read_lock();
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tb = fib_get_table(net, RT_TABLE_MAIN);
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if (tb)
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err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
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if (err == -EAGAIN)
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err = -ENETUNREACH;
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rcu_read_unlock();
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return err;
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}
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static inline bool fib4_has_custom_rules(const struct net *net)
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{
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return false;
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}
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static inline bool fib4_rule_default(const struct fib_rule *rule)
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{
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return true;
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}
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static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb,
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struct netlink_ext_ack *extack)
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{
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return 0;
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}
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static inline unsigned int fib4_rules_seq_read(struct net *net)
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{
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return 0;
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}
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static inline bool fib4_rules_early_flow_dissect(struct net *net,
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struct sk_buff *skb,
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struct flowi4 *fl4,
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struct flow_keys *flkeys)
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{
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return false;
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}
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#else /* CONFIG_IP_MULTIPLE_TABLES */
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int __net_init fib4_rules_init(struct net *net);
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void __net_exit fib4_rules_exit(struct net *net);
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struct fib_table *fib_new_table(struct net *net, u32 id);
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struct fib_table *fib_get_table(struct net *net, u32 id);
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int __fib_lookup(struct net *net, struct flowi4 *flp,
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struct fib_result *res, unsigned int flags);
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static inline int fib_lookup(struct net *net, struct flowi4 *flp,
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struct fib_result *res, unsigned int flags)
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{
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struct fib_table *tb;
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int err = -ENETUNREACH;
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flags |= FIB_LOOKUP_NOREF;
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if (net->ipv4.fib_has_custom_rules)
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return __fib_lookup(net, flp, res, flags);
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rcu_read_lock();
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res->tclassid = 0;
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tb = rcu_dereference_rtnl(net->ipv4.fib_main);
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if (tb)
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err = fib_table_lookup(tb, flp, res, flags);
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if (!err)
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goto out;
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tb = rcu_dereference_rtnl(net->ipv4.fib_default);
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if (tb)
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err = fib_table_lookup(tb, flp, res, flags);
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out:
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if (err == -EAGAIN)
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err = -ENETUNREACH;
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rcu_read_unlock();
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return err;
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}
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static inline bool fib4_has_custom_rules(const struct net *net)
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{
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return net->ipv4.fib_has_custom_rules;
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}
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bool fib4_rule_default(const struct fib_rule *rule);
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int fib4_rules_dump(struct net *net, struct notifier_block *nb,
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struct netlink_ext_ack *extack);
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unsigned int fib4_rules_seq_read(struct net *net);
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static inline bool fib4_rules_early_flow_dissect(struct net *net,
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struct sk_buff *skb,
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struct flowi4 *fl4,
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struct flow_keys *flkeys)
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{
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unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
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if (!net->ipv4.fib_rules_require_fldissect)
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return false;
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skb_flow_dissect_flow_keys(skb, flkeys, flag);
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fl4->fl4_sport = flkeys->ports.src;
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fl4->fl4_dport = flkeys->ports.dst;
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fl4->flowi4_proto = flkeys->basic.ip_proto;
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return true;
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}
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#endif /* CONFIG_IP_MULTIPLE_TABLES */
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/* Exported by fib_frontend.c */
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extern const struct nla_policy rtm_ipv4_policy[];
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void ip_fib_init(void);
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int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
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struct netlink_ext_ack *extack);
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__be32 fib_compute_spec_dst(struct sk_buff *skb);
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bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev);
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int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
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u8 tos, int oif, struct net_device *dev,
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struct in_device *idev, u32 *itag);
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#ifdef CONFIG_IP_ROUTE_CLASSID
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static inline int fib_num_tclassid_users(struct net *net)
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{
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return net->ipv4.fib_num_tclassid_users;
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}
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#else
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static inline int fib_num_tclassid_users(struct net *net)
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{
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return 0;
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}
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#endif
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int fib_unmerge(struct net *net);
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/* Exported by fib_semantics.c */
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int ip_fib_check_default(__be32 gw, struct net_device *dev);
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int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
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int fib_sync_down_addr(struct net_device *dev, __be32 local);
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int fib_sync_up(struct net_device *dev, unsigned char nh_flags);
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void fib_sync_mtu(struct net_device *dev, u32 orig_mtu);
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void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig);
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#ifdef CONFIG_IP_ROUTE_MULTIPATH
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int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
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const struct sk_buff *skb, struct flow_keys *flkeys);
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#endif
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int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
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struct netlink_ext_ack *extack);
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void fib_select_multipath(struct fib_result *res, int hash);
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void fib_select_path(struct net *net, struct fib_result *res,
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struct flowi4 *fl4, const struct sk_buff *skb);
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int fib_nh_init(struct net *net, struct fib_nh *fib_nh,
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struct fib_config *cfg, int nh_weight,
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struct netlink_ext_ack *extack);
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void fib_nh_release(struct net *net, struct fib_nh *fib_nh);
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int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *fc_encap,
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u16 fc_encap_type, void *cfg, gfp_t gfp_flags,
|
|
struct netlink_ext_ack *extack);
|
|
void fib_nh_common_release(struct fib_nh_common *nhc);
|
|
|
|
/* Exported by fib_trie.c */
|
|
void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri);
|
|
void fib_trie_init(void);
|
|
struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
|
|
|
|
static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
|
|
{
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
struct fib_nh_common *nhc = res->nhc;
|
|
#ifdef CONFIG_IP_MULTIPLE_TABLES
|
|
u32 rtag;
|
|
#endif
|
|
if (nhc->nhc_family == AF_INET) {
|
|
struct fib_nh *nh;
|
|
|
|
nh = container_of(nhc, struct fib_nh, nh_common);
|
|
*itag = nh->nh_tclassid << 16;
|
|
} else {
|
|
*itag = 0;
|
|
}
|
|
|
|
#ifdef CONFIG_IP_MULTIPLE_TABLES
|
|
rtag = res->tclassid;
|
|
if (*itag == 0)
|
|
*itag = (rtag<<16);
|
|
*itag |= (rtag>>16);
|
|
#endif
|
|
#endif
|
|
}
|
|
|
|
void fib_flush(struct net *net);
|
|
void free_fib_info(struct fib_info *fi);
|
|
|
|
static inline void fib_info_hold(struct fib_info *fi)
|
|
{
|
|
refcount_inc(&fi->fib_clntref);
|
|
}
|
|
|
|
static inline void fib_info_put(struct fib_info *fi)
|
|
{
|
|
if (refcount_dec_and_test(&fi->fib_clntref))
|
|
free_fib_info(fi);
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
int __net_init fib_proc_init(struct net *net);
|
|
void __net_exit fib_proc_exit(struct net *net);
|
|
#else
|
|
static inline int fib_proc_init(struct net *net)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void fib_proc_exit(struct net *net)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
|
|
|
|
int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
|
|
struct fib_dump_filter *filter,
|
|
struct netlink_callback *cb);
|
|
|
|
int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh,
|
|
u8 rt_family, unsigned char *flags, bool skip_oif);
|
|
int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh,
|
|
int nh_weight, u8 rt_family);
|
|
#endif /* _NET_FIB_H */
|