v4.19.13 snapshot.
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
new file mode 100644
index 0000000..f8eb78d
--- /dev/null
+++ b/net/ipv4/fib_rules.c
@@ -0,0 +1,425 @@
+/*
+ * INET An implementation of the TCP/IP protocol suite for the LINUX
+ * operating system. INET is implemented using the BSD Socket
+ * interface as the means of communication with the user level.
+ *
+ * IPv4 Forwarding Information Base: policy rules.
+ *
+ * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ * Thomas Graf <tgraf@suug.ch>
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Fixes:
+ * Rani Assaf : local_rule cannot be deleted
+ * Marc Boucher : routing by fwmark
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/netlink.h>
+#include <linux/inetdevice.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/export.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/ip_fib.h>
+#include <net/fib_rules.h>
+
+struct fib4_rule {
+ struct fib_rule common;
+ u8 dst_len;
+ u8 src_len;
+ u8 tos;
+ __be32 src;
+ __be32 srcmask;
+ __be32 dst;
+ __be32 dstmask;
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ u32 tclassid;
+#endif
+};
+
+static bool fib4_rule_matchall(const struct fib_rule *rule)
+{
+ struct fib4_rule *r = container_of(rule, struct fib4_rule, common);
+
+ if (r->dst_len || r->src_len || r->tos)
+ return false;
+ return fib_rule_matchall(rule);
+}
+
+bool fib4_rule_default(const struct fib_rule *rule)
+{
+ if (!fib4_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
+ rule->l3mdev)
+ return false;
+ if (rule->table != RT_TABLE_LOCAL && rule->table != RT_TABLE_MAIN &&
+ rule->table != RT_TABLE_DEFAULT)
+ return false;
+ return true;
+}
+EXPORT_SYMBOL_GPL(fib4_rule_default);
+
+int fib4_rules_dump(struct net *net, struct notifier_block *nb)
+{
+ return fib_rules_dump(net, nb, AF_INET);
+}
+
+unsigned int fib4_rules_seq_read(struct net *net)
+{
+ return fib_rules_seq_read(net, AF_INET);
+}
+
+int __fib_lookup(struct net *net, struct flowi4 *flp,
+ struct fib_result *res, unsigned int flags)
+{
+ struct fib_lookup_arg arg = {
+ .result = res,
+ .flags = flags,
+ };
+ int err;
+
+ /* update flow if oif or iif point to device enslaved to l3mdev */
+ l3mdev_update_flow(net, flowi4_to_flowi(flp));
+
+ err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ if (arg.rule)
+ res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
+ else
+ res->tclassid = 0;
+#endif
+
+ if (err == -ESRCH)
+ err = -ENETUNREACH;
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(__fib_lookup);
+
+static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
+ int flags, struct fib_lookup_arg *arg)
+{
+ int err = -EAGAIN;
+ struct fib_table *tbl;
+ 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;
+ }
+
+ rcu_read_lock();
+
+ tb_id = fib_rule_get_table(rule, arg);
+ tbl = fib_get_table(rule->fr_net, tb_id);
+ if (tbl)
+ err = fib_table_lookup(tbl, &flp->u.ip4,
+ (struct fib_result *)arg->result,
+ arg->flags);
+
+ rcu_read_unlock();
+ return err;
+}
+
+static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
+{
+ struct fib_result *result = (struct fib_result *) arg->result;
+ struct net_device *dev = NULL;
+
+ if (result->fi)
+ dev = result->fi->fib_dev;
+
+ /* do not accept result if the route does
+ * not meet the required prefix length
+ */
+ if (result->prefixlen <= 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:
+ if (!(arg->flags & FIB_LOOKUP_NOREF))
+ fib_info_put(result->fi);
+ return true;
+}
+
+static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
+{
+ struct fib4_rule *r = (struct fib4_rule *) rule;
+ struct flowi4 *fl4 = &fl->u.ip4;
+ __be32 daddr = fl4->daddr;
+ __be32 saddr = fl4->saddr;
+
+ if (((saddr ^ r->src) & r->srcmask) ||
+ ((daddr ^ r->dst) & r->dstmask))
+ return 0;
+
+ if (r->tos && (r->tos != fl4->flowi4_tos))
+ return 0;
+
+ if (rule->ip_proto && (rule->ip_proto != fl4->flowi4_proto))
+ return 0;
+
+ if (fib_rule_port_range_set(&rule->sport_range) &&
+ !fib_rule_port_inrange(&rule->sport_range, fl4->fl4_sport))
+ return 0;
+
+ if (fib_rule_port_range_set(&rule->dport_range) &&
+ !fib_rule_port_inrange(&rule->dport_range, fl4->fl4_dport))
+ return 0;
+
+ return 1;
+}
+
+static struct fib_table *fib_empty_table(struct net *net)
+{
+ u32 id;
+
+ for (id = 1; id <= RT_TABLE_MAX; id++)
+ if (!fib_get_table(net, id))
+ return fib_new_table(net, id);
+ return NULL;
+}
+
+static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
+ FRA_GENERIC_POLICY,
+ [FRA_FLOW] = { .type = NLA_U32 },
+};
+
+static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
+ struct fib_rule_hdr *frh,
+ struct nlattr **tb,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ int err = -EINVAL;
+ struct fib4_rule *rule4 = (struct fib4_rule *) rule;
+
+ if (frh->tos & ~IPTOS_TOS_MASK) {
+ NL_SET_ERR_MSG(extack, "Invalid tos");
+ goto errout;
+ }
+
+ /* split local/main if they are not already split */
+ err = fib_unmerge(net);
+ if (err)
+ goto errout;
+
+ if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) {
+ if (rule->action == FR_ACT_TO_TBL) {
+ struct fib_table *table;
+
+ table = fib_empty_table(net);
+ if (!table) {
+ err = -ENOBUFS;
+ goto errout;
+ }
+
+ rule->table = table->tb_id;
+ }
+ }
+
+ if (frh->src_len)
+ rule4->src = nla_get_in_addr(tb[FRA_SRC]);
+
+ if (frh->dst_len)
+ rule4->dst = nla_get_in_addr(tb[FRA_DST]);
+
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ if (tb[FRA_FLOW]) {
+ rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
+ if (rule4->tclassid)
+ net->ipv4.fib_num_tclassid_users++;
+ }
+#endif
+
+ if (fib_rule_requires_fldissect(rule))
+ net->ipv4.fib_rules_require_fldissect++;
+
+ rule4->src_len = frh->src_len;
+ rule4->srcmask = inet_make_mask(rule4->src_len);
+ rule4->dst_len = frh->dst_len;
+ rule4->dstmask = inet_make_mask(rule4->dst_len);
+ rule4->tos = frh->tos;
+
+ net->ipv4.fib_has_custom_rules = true;
+
+ err = 0;
+errout:
+ return err;
+}
+
+static int fib4_rule_delete(struct fib_rule *rule)
+{
+ struct net *net = rule->fr_net;
+ int err;
+
+ /* split local/main if they are not already split */
+ err = fib_unmerge(net);
+ if (err)
+ goto errout;
+
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ if (((struct fib4_rule *)rule)->tclassid)
+ net->ipv4.fib_num_tclassid_users--;
+#endif
+ net->ipv4.fib_has_custom_rules = true;
+
+ if (net->ipv4.fib_rules_require_fldissect &&
+ fib_rule_requires_fldissect(rule))
+ net->ipv4.fib_rules_require_fldissect--;
+errout:
+ return err;
+}
+
+static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
+ struct nlattr **tb)
+{
+ struct fib4_rule *rule4 = (struct fib4_rule *) rule;
+
+ if (frh->src_len && (rule4->src_len != frh->src_len))
+ return 0;
+
+ if (frh->dst_len && (rule4->dst_len != frh->dst_len))
+ return 0;
+
+ if (frh->tos && (rule4->tos != frh->tos))
+ return 0;
+
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
+ return 0;
+#endif
+
+ if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
+ return 0;
+
+ if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
+ return 0;
+
+ return 1;
+}
+
+static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
+ struct fib_rule_hdr *frh)
+{
+ struct fib4_rule *rule4 = (struct fib4_rule *) rule;
+
+ frh->dst_len = rule4->dst_len;
+ frh->src_len = rule4->src_len;
+ frh->tos = rule4->tos;
+
+ if ((rule4->dst_len &&
+ nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
+ (rule4->src_len &&
+ nla_put_in_addr(skb, FRA_SRC, rule4->src)))
+ goto nla_put_failure;
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ if (rule4->tclassid &&
+ nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
+ goto nla_put_failure;
+#endif
+ return 0;
+
+nla_put_failure:
+ return -ENOBUFS;
+}
+
+static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
+{
+ return nla_total_size(4) /* dst */
+ + nla_total_size(4) /* src */
+ + nla_total_size(4); /* flow */
+}
+
+static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
+{
+ rt_cache_flush(ops->fro_net);
+}
+
+static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
+ .family = AF_INET,
+ .rule_size = sizeof(struct fib4_rule),
+ .addr_size = sizeof(u32),
+ .action = fib4_rule_action,
+ .suppress = fib4_rule_suppress,
+ .match = fib4_rule_match,
+ .configure = fib4_rule_configure,
+ .delete = fib4_rule_delete,
+ .compare = fib4_rule_compare,
+ .fill = fib4_rule_fill,
+ .nlmsg_payload = fib4_rule_nlmsg_payload,
+ .flush_cache = fib4_rule_flush_cache,
+ .nlgroup = RTNLGRP_IPV4_RULE,
+ .policy = fib4_rule_policy,
+ .owner = THIS_MODULE,
+};
+
+static int fib_default_rules_init(struct fib_rules_ops *ops)
+{
+ int err;
+
+ err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
+ if (err < 0)
+ return err;
+ err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
+ if (err < 0)
+ return err;
+ err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
+ if (err < 0)
+ return err;
+ return 0;
+}
+
+int __net_init fib4_rules_init(struct net *net)
+{
+ int err;
+ struct fib_rules_ops *ops;
+
+ ops = fib_rules_register(&fib4_rules_ops_template, net);
+ if (IS_ERR(ops))
+ return PTR_ERR(ops);
+
+ err = fib_default_rules_init(ops);
+ if (err < 0)
+ goto fail;
+ net->ipv4.rules_ops = ops;
+ net->ipv4.fib_has_custom_rules = false;
+ net->ipv4.fib_rules_require_fldissect = 0;
+ return 0;
+
+fail:
+ /* also cleans all rules already added */
+ fib_rules_unregister(ops);
+ return err;
+}
+
+void __net_exit fib4_rules_exit(struct net *net)
+{
+ fib_rules_unregister(net->ipv4.rules_ops);
+}