![Stephen Hemminger](/assets/img/avatar_default.png)
The FIB algorithim for IPV4 is set at compile time, but kernel goes through the overhead of function call indirection at runtime. Save some cycles by turning the indirect calls to direct calls to either hash or trie code. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
330 lines
7 KiB
C
330 lines
7 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* IPv4 Forwarding Information Base: policy rules.
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*
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* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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* Thomas Graf <tgraf@suug.ch>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Fixes:
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* Rani Assaf : local_rule cannot be deleted
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* Marc Boucher : routing by fwmark
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/netlink.h>
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#include <linux/inetdevice.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/rcupdate.h>
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#include <net/ip.h>
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#include <net/route.h>
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#include <net/tcp.h>
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#include <net/ip_fib.h>
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#include <net/fib_rules.h>
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struct fib4_rule
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{
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struct fib_rule common;
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u8 dst_len;
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u8 src_len;
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u8 tos;
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__be32 src;
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__be32 srcmask;
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__be32 dst;
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__be32 dstmask;
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#ifdef CONFIG_NET_CLS_ROUTE
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u32 tclassid;
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#endif
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};
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#ifdef CONFIG_NET_CLS_ROUTE
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u32 fib_rules_tclass(struct fib_result *res)
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{
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return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
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}
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#endif
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int fib_lookup(struct net *net, struct flowi *flp, struct fib_result *res)
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{
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struct fib_lookup_arg arg = {
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.result = res,
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};
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int err;
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err = fib_rules_lookup(net->ipv4.rules_ops, flp, 0, &arg);
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res->r = arg.rule;
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return err;
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}
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static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
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int flags, struct fib_lookup_arg *arg)
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{
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int err = -EAGAIN;
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struct fib_table *tbl;
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switch (rule->action) {
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case FR_ACT_TO_TBL:
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break;
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case FR_ACT_UNREACHABLE:
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err = -ENETUNREACH;
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goto errout;
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case FR_ACT_PROHIBIT:
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err = -EACCES;
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goto errout;
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case FR_ACT_BLACKHOLE:
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default:
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err = -EINVAL;
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goto errout;
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}
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if ((tbl = fib_get_table(rule->fr_net, rule->table)) == NULL)
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goto errout;
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err = fib_table_lookup(tbl, flp, (struct fib_result *) arg->result);
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if (err > 0)
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err = -EAGAIN;
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errout:
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return err;
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}
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static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
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{
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struct fib4_rule *r = (struct fib4_rule *) rule;
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__be32 daddr = fl->fl4_dst;
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__be32 saddr = fl->fl4_src;
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if (((saddr ^ r->src) & r->srcmask) ||
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((daddr ^ r->dst) & r->dstmask))
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return 0;
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if (r->tos && (r->tos != fl->fl4_tos))
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return 0;
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return 1;
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}
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static struct fib_table *fib_empty_table(struct net *net)
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{
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u32 id;
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for (id = 1; id <= RT_TABLE_MAX; id++)
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if (fib_get_table(net, id) == NULL)
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return fib_new_table(net, id);
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return NULL;
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}
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static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
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FRA_GENERIC_POLICY,
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[FRA_FLOW] = { .type = NLA_U32 },
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};
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static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
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struct fib_rule_hdr *frh,
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struct nlattr **tb)
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{
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struct net *net = sock_net(skb->sk);
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int err = -EINVAL;
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struct fib4_rule *rule4 = (struct fib4_rule *) rule;
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if (frh->tos & ~IPTOS_TOS_MASK)
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goto errout;
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if (rule->table == RT_TABLE_UNSPEC) {
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if (rule->action == FR_ACT_TO_TBL) {
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struct fib_table *table;
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table = fib_empty_table(net);
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if (table == NULL) {
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err = -ENOBUFS;
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goto errout;
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}
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rule->table = table->tb_id;
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}
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}
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if (frh->src_len)
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rule4->src = nla_get_be32(tb[FRA_SRC]);
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if (frh->dst_len)
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rule4->dst = nla_get_be32(tb[FRA_DST]);
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#ifdef CONFIG_NET_CLS_ROUTE
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if (tb[FRA_FLOW])
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rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
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#endif
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rule4->src_len = frh->src_len;
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rule4->srcmask = inet_make_mask(rule4->src_len);
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rule4->dst_len = frh->dst_len;
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rule4->dstmask = inet_make_mask(rule4->dst_len);
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rule4->tos = frh->tos;
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err = 0;
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errout:
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return err;
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}
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static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
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struct nlattr **tb)
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{
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struct fib4_rule *rule4 = (struct fib4_rule *) rule;
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if (frh->src_len && (rule4->src_len != frh->src_len))
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return 0;
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if (frh->dst_len && (rule4->dst_len != frh->dst_len))
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return 0;
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if (frh->tos && (rule4->tos != frh->tos))
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return 0;
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#ifdef CONFIG_NET_CLS_ROUTE
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if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
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return 0;
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#endif
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if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
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return 0;
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if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
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return 0;
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return 1;
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}
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static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
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struct fib_rule_hdr *frh)
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{
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struct fib4_rule *rule4 = (struct fib4_rule *) rule;
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frh->family = AF_INET;
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frh->dst_len = rule4->dst_len;
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frh->src_len = rule4->src_len;
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frh->tos = rule4->tos;
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if (rule4->dst_len)
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NLA_PUT_BE32(skb, FRA_DST, rule4->dst);
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if (rule4->src_len)
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NLA_PUT_BE32(skb, FRA_SRC, rule4->src);
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#ifdef CONFIG_NET_CLS_ROUTE
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if (rule4->tclassid)
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NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
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#endif
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return 0;
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nla_put_failure:
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return -ENOBUFS;
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}
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static u32 fib4_rule_default_pref(struct fib_rules_ops *ops)
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{
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struct list_head *pos;
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struct fib_rule *rule;
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if (!list_empty(&ops->rules_list)) {
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pos = ops->rules_list.next;
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if (pos->next != &ops->rules_list) {
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rule = list_entry(pos->next, struct fib_rule, list);
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if (rule->pref)
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return rule->pref - 1;
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}
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}
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return 0;
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}
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static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
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{
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return nla_total_size(4) /* dst */
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+ nla_total_size(4) /* src */
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+ nla_total_size(4); /* flow */
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}
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static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
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{
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rt_cache_flush(ops->fro_net, -1);
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}
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static struct fib_rules_ops fib4_rules_ops_template = {
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.family = AF_INET,
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.rule_size = sizeof(struct fib4_rule),
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.addr_size = sizeof(u32),
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.action = fib4_rule_action,
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.match = fib4_rule_match,
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.configure = fib4_rule_configure,
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.compare = fib4_rule_compare,
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.fill = fib4_rule_fill,
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.default_pref = fib4_rule_default_pref,
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.nlmsg_payload = fib4_rule_nlmsg_payload,
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.flush_cache = fib4_rule_flush_cache,
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.nlgroup = RTNLGRP_IPV4_RULE,
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.policy = fib4_rule_policy,
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.owner = THIS_MODULE,
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};
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static int fib_default_rules_init(struct fib_rules_ops *ops)
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{
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int err;
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err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, FIB_RULE_PERMANENT);
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if (err < 0)
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return err;
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err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
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if (err < 0)
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return err;
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err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
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if (err < 0)
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return err;
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return 0;
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}
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int __net_init fib4_rules_init(struct net *net)
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{
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int err;
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struct fib_rules_ops *ops;
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ops = kmemdup(&fib4_rules_ops_template, sizeof(*ops), GFP_KERNEL);
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if (ops == NULL)
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return -ENOMEM;
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INIT_LIST_HEAD(&ops->rules_list);
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ops->fro_net = net;
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fib_rules_register(ops);
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err = fib_default_rules_init(ops);
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if (err < 0)
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goto fail;
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net->ipv4.rules_ops = ops;
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return 0;
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fail:
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/* also cleans all rules already added */
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fib_rules_unregister(ops);
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kfree(ops);
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return err;
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}
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void __net_exit fib4_rules_exit(struct net *net)
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{
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fib_rules_unregister(net->ipv4.rules_ops);
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kfree(net->ipv4.rules_ops);
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}
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