From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- net/ipv6/fib6_rules.c | 522 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 522 insertions(+) create mode 100644 net/ipv6/fib6_rules.c (limited to 'net/ipv6/fib6_rules.c') diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c new file mode 100644 index 0000000000..7c20038330 --- /dev/null +++ b/net/ipv6/fib6_rules.c @@ -0,0 +1,522 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * net/ipv6/fib6_rules.c IPv6 Routing Policy Rules + * + * Copyright (C)2003-2006 Helsinki University of Technology + * Copyright (C)2003-2006 USAGI/WIDE Project + * + * Authors + * Thomas Graf + * Ville Nuorvala + */ + +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +struct fib6_rule { + struct fib_rule common; + struct rt6key src; + struct rt6key dst; + dscp_t dscp; +}; + +static bool fib6_rule_matchall(const struct fib_rule *rule) +{ + struct fib6_rule *r = container_of(rule, struct fib6_rule, common); + + if (r->dst.plen || r->src.plen || r->dscp) + return false; + return fib_rule_matchall(rule); +} + +bool fib6_rule_default(const struct fib_rule *rule) +{ + if (!fib6_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL || + rule->l3mdev) + return false; + if (rule->table != RT6_TABLE_LOCAL && rule->table != RT6_TABLE_MAIN) + return false; + return true; +} +EXPORT_SYMBOL_GPL(fib6_rule_default); + +int fib6_rules_dump(struct net *net, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + return fib_rules_dump(net, nb, AF_INET6, extack); +} + +unsigned int fib6_rules_seq_read(struct net *net) +{ + return fib_rules_seq_read(net, AF_INET6); +} + +/* called with rcu lock held; no reference taken on fib6_info */ +int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, + struct fib6_result *res, int flags) +{ + int err; + + if (net->ipv6.fib6_has_custom_rules) { + struct fib_lookup_arg arg = { + .lookup_ptr = fib6_table_lookup, + .lookup_data = &oif, + .result = res, + .flags = FIB_LOOKUP_NOREF, + }; + + l3mdev_update_flow(net, flowi6_to_flowi(fl6)); + + err = fib_rules_lookup(net->ipv6.fib6_rules_ops, + flowi6_to_flowi(fl6), flags, &arg); + } else { + err = fib6_table_lookup(net, net->ipv6.fib6_local_tbl, oif, + fl6, res, flags); + if (err || res->f6i == net->ipv6.fib6_null_entry) + err = fib6_table_lookup(net, net->ipv6.fib6_main_tbl, + oif, fl6, res, flags); + } + + return err; +} + +struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, + const struct sk_buff *skb, + int flags, pol_lookup_t lookup) +{ + if (net->ipv6.fib6_has_custom_rules) { + struct fib6_result res = {}; + struct fib_lookup_arg arg = { + .lookup_ptr = lookup, + .lookup_data = skb, + .result = &res, + .flags = FIB_LOOKUP_NOREF, + }; + + /* update flow if oif or iif point to device enslaved to l3mdev */ + l3mdev_update_flow(net, flowi6_to_flowi(fl6)); + + fib_rules_lookup(net->ipv6.fib6_rules_ops, + flowi6_to_flowi(fl6), flags, &arg); + + if (res.rt6) + return &res.rt6->dst; + } else { + struct rt6_info *rt; + + rt = pol_lookup_func(lookup, + net, net->ipv6.fib6_local_tbl, fl6, skb, flags); + if (rt != net->ipv6.ip6_null_entry && rt->dst.error != -EAGAIN) + return &rt->dst; + ip6_rt_put_flags(rt, flags); + rt = pol_lookup_func(lookup, + net, net->ipv6.fib6_main_tbl, fl6, skb, flags); + if (rt->dst.error != -EAGAIN) + return &rt->dst; + ip6_rt_put_flags(rt, flags); + } + + if (!(flags & RT6_LOOKUP_F_DST_NOREF)) + dst_hold(&net->ipv6.ip6_null_entry->dst); + return &net->ipv6.ip6_null_entry->dst; +} + +static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags, + struct flowi6 *flp6, const struct net_device *dev) +{ + 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; + + if (ipv6_dev_get_saddr(net, dev, &flp6->daddr, + rt6_flags2srcprefs(flags), &saddr)) + return -EAGAIN; + + if (!ipv6_prefix_equal(&saddr, &r->src.addr, r->src.plen)) + return -EAGAIN; + + flp6->saddr = saddr; + } + + return 0; +} + +static int fib6_rule_action_alt(struct fib_rule *rule, struct flowi *flp, + int flags, struct fib_lookup_arg *arg) +{ + struct fib6_result *res = arg->result; + struct flowi6 *flp6 = &flp->u.ip6; + struct net *net = rule->fr_net; + struct fib6_table *table; + int err, *oif; + u32 tb_id; + + switch (rule->action) { + case FR_ACT_TO_TBL: + break; + case FR_ACT_UNREACHABLE: + return -ENETUNREACH; + case FR_ACT_PROHIBIT: + return -EACCES; + case FR_ACT_BLACKHOLE: + default: + return -EINVAL; + } + + tb_id = fib_rule_get_table(rule, arg); + table = fib6_get_table(net, tb_id); + if (!table) + return -EAGAIN; + + oif = (int *)arg->lookup_data; + err = fib6_table_lookup(net, table, *oif, flp6, res, flags); + if (!err && res->f6i != net->ipv6.fib6_null_entry) + err = fib6_rule_saddr(net, rule, flags, flp6, + res->nh->fib_nh_dev); + else + err = -EAGAIN; + + return err; +} + +static int __fib6_rule_action(struct fib_rule *rule, struct flowi *flp, + int flags, struct fib_lookup_arg *arg) +{ + struct fib6_result *res = arg->result; + struct flowi6 *flp6 = &flp->u.ip6; + struct rt6_info *rt = NULL; + struct fib6_table *table; + struct net *net = rule->fr_net; + pol_lookup_t lookup = arg->lookup_ptr; + int err = 0; + u32 tb_id; + + switch (rule->action) { + case FR_ACT_TO_TBL: + break; + case FR_ACT_UNREACHABLE: + err = -ENETUNREACH; + rt = net->ipv6.ip6_null_entry; + goto discard_pkt; + default: + case FR_ACT_BLACKHOLE: + err = -EINVAL; + rt = net->ipv6.ip6_blk_hole_entry; + goto discard_pkt; + case FR_ACT_PROHIBIT: + err = -EACCES; + rt = net->ipv6.ip6_prohibit_entry; + goto discard_pkt; + } + + tb_id = fib_rule_get_table(rule, arg); + table = fib6_get_table(net, tb_id); + if (!table) { + err = -EAGAIN; + goto out; + } + + rt = pol_lookup_func(lookup, + net, table, flp6, arg->lookup_data, flags); + if (rt != net->ipv6.ip6_null_entry) { + err = fib6_rule_saddr(net, rule, flags, flp6, + ip6_dst_idev(&rt->dst)->dev); + + if (err == -EAGAIN) + goto again; + + err = rt->dst.error; + if (err != -EAGAIN) + goto out; + } +again: + ip6_rt_put_flags(rt, flags); + err = -EAGAIN; + rt = NULL; + goto out; + +discard_pkt: + if (!(flags & RT6_LOOKUP_F_DST_NOREF)) + dst_hold(&rt->dst); +out: + res->rt6 = rt; + return err; +} + +INDIRECT_CALLABLE_SCOPE int fib6_rule_action(struct fib_rule *rule, + struct flowi *flp, int flags, + struct fib_lookup_arg *arg) +{ + if (arg->lookup_ptr == fib6_table_lookup) + return fib6_rule_action_alt(rule, flp, flags, arg); + + return __fib6_rule_action(rule, flp, flags, arg); +} + +INDIRECT_CALLABLE_SCOPE bool fib6_rule_suppress(struct fib_rule *rule, + int flags, + struct fib_lookup_arg *arg) +{ + struct fib6_result *res = arg->result; + struct rt6_info *rt = res->rt6; + struct net_device *dev = NULL; + + if (!rt) + return false; + + if (rt->rt6i_idev) + dev = rt->rt6i_idev->dev; + + /* do not accept result if the route does + * not meet the required prefix length + */ + if (rt->rt6i_dst.plen <= rule->suppress_prefixlen) + goto suppress_route; + + /* do not accept result if the route uses a device + * belonging to a forbidden interface group + */ + if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup) + goto suppress_route; + + return false; + +suppress_route: + ip6_rt_put_flags(rt, flags); + return true; +} + +INDIRECT_CALLABLE_SCOPE int fib6_rule_match(struct fib_rule *rule, + struct flowi *fl, int flags) +{ + struct fib6_rule *r = (struct fib6_rule *) rule; + struct flowi6 *fl6 = &fl->u.ip6; + + if (r->dst.plen && + !ipv6_prefix_equal(&fl6->daddr, &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(&fl6->saddr, &r->src.addr, + r->src.plen)) + return 0; + } else if (!(r->common.flags & FIB_RULE_FIND_SADDR)) + return 0; + } + + if (r->dscp && r->dscp != ip6_dscp(fl6->flowlabel)) + return 0; + + if (rule->ip_proto && (rule->ip_proto != fl6->flowi6_proto)) + return 0; + + if (fib_rule_port_range_set(&rule->sport_range) && + !fib_rule_port_inrange(&rule->sport_range, fl6->fl6_sport)) + return 0; + + if (fib_rule_port_range_set(&rule->dport_range) && + !fib_rule_port_inrange(&rule->dport_range, fl6->fl6_dport)) + return 0; + + return 1; +} + +static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb, + struct fib_rule_hdr *frh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + int err = -EINVAL; + struct net *net = sock_net(skb->sk); + struct fib6_rule *rule6 = (struct fib6_rule *) rule; + + if (!inet_validate_dscp(frh->tos)) { + NL_SET_ERR_MSG(extack, + "Invalid dsfield (tos): ECN bits must be 0"); + goto errout; + } + rule6->dscp = inet_dsfield_to_dscp(frh->tos); + + if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) { + if (rule->table == RT6_TABLE_UNSPEC) { + NL_SET_ERR_MSG(extack, "Invalid table"); + goto errout; + } + + if (fib6_new_table(net, rule->table) == NULL) { + err = -ENOBUFS; + goto errout; + } + } + + if (frh->src_len) + rule6->src.addr = nla_get_in6_addr(tb[FRA_SRC]); + + if (frh->dst_len) + rule6->dst.addr = nla_get_in6_addr(tb[FRA_DST]); + + rule6->src.plen = frh->src_len; + rule6->dst.plen = frh->dst_len; + + if (fib_rule_requires_fldissect(rule)) + net->ipv6.fib6_rules_require_fldissect++; + + net->ipv6.fib6_has_custom_rules = true; + err = 0; +errout: + return err; +} + +static int fib6_rule_delete(struct fib_rule *rule) +{ + struct net *net = rule->fr_net; + + if (net->ipv6.fib6_rules_require_fldissect && + fib_rule_requires_fldissect(rule)) + net->ipv6.fib6_rules_require_fldissect--; + + return 0; +} + +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 && inet_dscp_to_dsfield(rule6->dscp) != 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->dst_len = rule6->dst.plen; + frh->src_len = rule6->src.plen; + frh->tos = inet_dscp_to_dsfield(rule6->dscp); + + if ((rule6->dst.plen && + nla_put_in6_addr(skb, FRA_DST, &rule6->dst.addr)) || + (rule6->src.plen && + nla_put_in6_addr(skb, FRA_SRC, &rule6->src.addr))) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -ENOBUFS; +} + +static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule) +{ + return nla_total_size(16) /* dst */ + + nla_total_size(16); /* src */ +} + +static const struct fib_rules_ops __net_initconst 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, + .suppress = fib6_rule_suppress, + .configure = fib6_rule_configure, + .delete = fib6_rule_delete, + .compare = fib6_rule_compare, + .fill = fib6_rule_fill, + .nlmsg_payload = fib6_rule_nlmsg_payload, + .nlgroup = RTNLGRP_IPV6_RULE, + .owner = THIS_MODULE, + .fro_net = &init_net, +}; + +static int __net_init fib6_rules_net_init(struct net *net) +{ + struct fib_rules_ops *ops; + int err; + + ops = fib_rules_register(&fib6_rules_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); + + err = fib_default_rule_add(ops, 0, RT6_TABLE_LOCAL, 0); + if (err) + goto out_fib6_rules_ops; + + err = fib_default_rule_add(ops, 0x7FFE, RT6_TABLE_MAIN, 0); + if (err) + goto out_fib6_rules_ops; + + net->ipv6.fib6_rules_ops = ops; + net->ipv6.fib6_rules_require_fldissect = 0; +out: + return err; + +out_fib6_rules_ops: + fib_rules_unregister(ops); + goto out; +} + +static void __net_exit fib6_rules_net_exit_batch(struct list_head *net_list) +{ + struct net *net; + + rtnl_lock(); + list_for_each_entry(net, net_list, exit_list) { + fib_rules_unregister(net->ipv6.fib6_rules_ops); + cond_resched(); + } + rtnl_unlock(); +} + +static struct pernet_operations fib6_rules_net_ops = { + .init = fib6_rules_net_init, + .exit_batch = fib6_rules_net_exit_batch, +}; + +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); +} -- cgit v1.2.3