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root/net/ipv6/fib6_rules.c

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DEFINITIONS

This source file includes following definitions.
  1. fib6_rule_lookup
  2. fib6_rule_action
  3. fib6_rule_match
  4. fib6_rule_configure
  5. fib6_rule_compare
  6. fib6_rule_fill
  7. fib6_rule_default_pref
  8. fib6_rule_nlmsg_payload
  9. fib6_rules_net_init
  10. fib6_rules_net_exit
  11. fib6_rules_init
  12. fib6_rules_cleanup

/*
 * net/ipv6/fib6_rules.c        IPv6 Routing Policy Rules
 *
 * Copyright (C)2003-2006 Helsinki University of Technology
 * Copyright (C)2003-2006 USAGI/WIDE Project
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License as
 *      published by the Free Software Foundation, version 2.
 *
 * Authors
 *      Thomas Graf             <tgraf@suug.ch>
 *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
 */

#include <linux/netdevice.h>

#include <net/fib_rules.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/netlink.h>

struct fib6_rule
{
        struct fib_rule         common;
        struct rt6key           src;
        struct rt6key           dst;
        u8                      tclass;
};

struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi *fl,
                                   int flags, pol_lookup_t lookup)
{
        struct fib_lookup_arg arg = {
                .lookup_ptr = lookup,
        };

        fib_rules_lookup(net->ipv6.fib6_rules_ops, fl, flags, &arg);
        if (arg.rule)
                fib_rule_put(arg.rule);

        if (arg.result)
                return arg.result;

        dst_hold(&net->ipv6.ip6_null_entry->u.dst);
        return &net->ipv6.ip6_null_entry->u.dst;
}

static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
                            int flags, struct fib_lookup_arg *arg)
{
        struct rt6_info *rt = NULL;
        struct fib6_table *table;
        struct net *net = rule->fr_net;
        pol_lookup_t lookup = arg->lookup_ptr;

        switch (rule->action) {
        case FR_ACT_TO_TBL:
                break;
        case FR_ACT_UNREACHABLE:
                rt = net->ipv6.ip6_null_entry;
                goto discard_pkt;
        default:
        case FR_ACT_BLACKHOLE:
                rt = net->ipv6.ip6_blk_hole_entry;
                goto discard_pkt;
        case FR_ACT_PROHIBIT:
                rt = net->ipv6.ip6_prohibit_entry;
                goto discard_pkt;
        }

        table = fib6_get_table(net, rule->table);
        if (table)
                rt = lookup(net, table, flp, flags);

        if (rt != net->ipv6.ip6_null_entry) {
                struct fib6_rule *r = (struct fib6_rule *)rule;

                /*
                 * If we need to find a source address for this traffic,
                 * we check the result if it meets requirement of the rule.
                 */
                if ((rule->flags & FIB_RULE_FIND_SADDR) &&
                    r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
                        struct in6_addr saddr;
                        unsigned int srcprefs = 0;

                        if (flags & RT6_LOOKUP_F_SRCPREF_TMP)
                                srcprefs |= IPV6_PREFER_SRC_TMP;
                        if (flags & RT6_LOOKUP_F_SRCPREF_PUBLIC)
                                srcprefs |= IPV6_PREFER_SRC_PUBLIC;
                        if (flags & RT6_LOOKUP_F_SRCPREF_COA)
                                srcprefs |= IPV6_PREFER_SRC_COA;

                        if (ipv6_dev_get_saddr(net,
                                               ip6_dst_idev(&rt->u.dst)->dev,
                                               &flp->fl6_dst, srcprefs,
                                               &saddr))
                                goto again;
                        if (!ipv6_prefix_equal(&saddr, &r->src.addr,
                                               r->src.plen))
                                goto again;
                        ipv6_addr_copy(&flp->fl6_src, &saddr);
                }
                goto out;
        }
again:
        dst_release(&rt->u.dst);
        rt = NULL;
        goto out;

discard_pkt:
        dst_hold(&rt->u.dst);
out:
        arg->result = rt;
        return rt == NULL ? -EAGAIN : 0;
}


static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
{
        struct fib6_rule *r = (struct fib6_rule *) rule;

        if (r->dst.plen &&
            !ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
                return 0;

        /*
         * If FIB_RULE_FIND_SADDR is set and we do not have a
         * source address for the traffic, we defer check for
         * source address.
         */
        if (r->src.plen) {
                if (flags & RT6_LOOKUP_F_HAS_SADDR) {
                        if (!ipv6_prefix_equal(&fl->fl6_src, &r->src.addr,
                                               r->src.plen))
                                return 0;
                } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
                        return 0;
        }

        if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
                return 0;

        return 1;
}

static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
        FRA_GENERIC_POLICY,
};

static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
                               struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
                               struct nlattr **tb)
{
        int err = -EINVAL;
        struct net *net = sock_net(skb->sk);
        struct fib6_rule *rule6 = (struct fib6_rule *) rule;

        if (rule->action == FR_ACT_TO_TBL) {
                if (rule->table == RT6_TABLE_UNSPEC)
                        goto errout;

                if (fib6_new_table(net, rule->table) == NULL) {
                        err = -ENOBUFS;
                        goto errout;
                }
        }

        if (frh->src_len)
                nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
                           sizeof(struct in6_addr));

        if (frh->dst_len)
                nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
                           sizeof(struct in6_addr));

        rule6->src.plen = frh->src_len;
        rule6->dst.plen = frh->dst_len;
        rule6->tclass = frh->tos;

        err = 0;
errout:
        return err;
}

static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
                             struct nlattr **tb)
{
        struct fib6_rule *rule6 = (struct fib6_rule *) rule;

        if (frh->src_len && (rule6->src.plen != frh->src_len))
                return 0;

        if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
                return 0;

        if (frh->tos && (rule6->tclass != frh->tos))
                return 0;

        if (frh->src_len &&
            nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
                return 0;

        if (frh->dst_len &&
            nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
                return 0;

        return 1;
}

static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
                          struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
{
        struct fib6_rule *rule6 = (struct fib6_rule *) rule;

        frh->family = AF_INET6;
        frh->dst_len = rule6->dst.plen;
        frh->src_len = rule6->src.plen;
        frh->tos = rule6->tclass;

        if (rule6->dst.plen)
                NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
                        &rule6->dst.addr);

        if (rule6->src.plen)
                NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
                        &rule6->src.addr);

        return 0;

nla_put_failure:
        return -ENOBUFS;
}

static u32 fib6_rule_default_pref(struct fib_rules_ops *ops)
{
        return 0x3FFF;
}

static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
{
        return nla_total_size(16) /* dst */
               + nla_total_size(16); /* src */
}

static struct fib_rules_ops fib6_rules_ops_template = {
        .family                 = AF_INET6,
        .rule_size              = sizeof(struct fib6_rule),
        .addr_size              = sizeof(struct in6_addr),
        .action                 = fib6_rule_action,
        .match                  = fib6_rule_match,
        .configure              = fib6_rule_configure,
        .compare                = fib6_rule_compare,
        .fill                   = fib6_rule_fill,
        .default_pref           = fib6_rule_default_pref,
        .nlmsg_payload          = fib6_rule_nlmsg_payload,
        .nlgroup                = RTNLGRP_IPV6_RULE,
        .policy                 = fib6_rule_policy,
        .owner                  = THIS_MODULE,
        .fro_net                = &init_net,
};

static int fib6_rules_net_init(struct net *net)
{
        int err = -ENOMEM;

        net->ipv6.fib6_rules_ops = kmemdup(&fib6_rules_ops_template,
                                           sizeof(*net->ipv6.fib6_rules_ops),
                                           GFP_KERNEL);
        if (!net->ipv6.fib6_rules_ops)
                goto out;

        net->ipv6.fib6_rules_ops->fro_net = net;
        INIT_LIST_HEAD(&net->ipv6.fib6_rules_ops->rules_list);

        err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0,
                                   RT6_TABLE_LOCAL, FIB_RULE_PERMANENT);
        if (err)
                goto out_fib6_rules_ops;

        err = fib_default_rule_add(net->ipv6.fib6_rules_ops,
                                   0x7FFE, RT6_TABLE_MAIN, 0);
        if (err)
                goto out_fib6_default_rule_add;

        err = fib_rules_register(net->ipv6.fib6_rules_ops);
        if (err)
                goto out_fib6_default_rule_add;
out:
        return err;

out_fib6_default_rule_add:
        fib_rules_cleanup_ops(net->ipv6.fib6_rules_ops);
out_fib6_rules_ops:
        kfree(net->ipv6.fib6_rules_ops);
        goto out;
}

static void fib6_rules_net_exit(struct net *net)
{
        fib_rules_unregister(net->ipv6.fib6_rules_ops);
        kfree(net->ipv6.fib6_rules_ops);
}

static struct pernet_operations fib6_rules_net_ops = {
        .init = fib6_rules_net_init,
        .exit = fib6_rules_net_exit,
};

int __init fib6_rules_init(void)
{
        return register_pernet_subsys(&fib6_rules_net_ops);
}


void fib6_rules_cleanup(void)
{
        unregister_pernet_subsys(&fib6_rules_net_ops);
}

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