/* * 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 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 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); }