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-rw-r--r--net/ipv6/fib6_rules.c522
1 files changed, 522 insertions, 0 deletions
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
new file mode 100644
index 000000000..7c2003833
--- /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 <tgraf@suug.ch>
+ * Ville Nuorvala <vnuorval@tcs.hut.fi>
+ */
+
+#include <linux/netdevice.h>
+#include <linux/notifier.h>
+#include <linux/export.h>
+#include <linux/indirect_call_wrapper.h>
+
+#include <net/fib_rules.h>
+#include <net/inet_dscp.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;
+ 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);
+}