1 files changed, 397 insertions, 0 deletions

diff --git a/include/net/route.h b/include/net/route.h
new file mode 100644
index 000000000..2551f3f03
--- /dev/null
+++ b/include/net/route.h
@@ -0,0 +1,397 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * 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.
+ *
+ *		Definitions for the IP router.
+ *
+ * Version:	@(#)route.h	1.0.4	05/27/93
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ * Fixes:
+ *		Alan Cox	:	Reformatted. Added ip_rt_local()
+ *		Alan Cox	:	Support for TCP parameters.
+ *		Alexey Kuznetsov:	Major changes for new routing code.
+ *		Mike McLagan    :	Routing by source
+ *		Robert Olsson   :	Added rt_cache statistics
+ */
+#ifndef _ROUTE_H
+#define _ROUTE_H
+
+#include <net/dst.h>
+#include <net/inetpeer.h>
+#include <net/flow.h>
+#include <net/inet_sock.h>
+#include <net/ip_fib.h>
+#include <net/arp.h>
+#include <net/ndisc.h>
+#include <linux/in_route.h>
+#include <linux/rtnetlink.h>
+#include <linux/rcupdate.h>
+#include <linux/route.h>
+#include <linux/ip.h>
+#include <linux/cache.h>
+#include <linux/security.h>
+
+/* IPv4 datagram length is stored into 16bit field (tot_len) */
+#define IP_MAX_MTU	0xFFFFU
+
+#define RTO_ONLINK	0x01
+
+#define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
+#define RT_CONN_FLAGS_TOS(sk,tos)   (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))
+
+struct fib_nh;
+struct fib_info;
+struct uncached_list;
+struct rtable {
+	struct dst_entry	dst;
+
+	int			rt_genid;
+	unsigned int		rt_flags;
+	__u16			rt_type;
+	__u8			rt_is_input;
+	__u8			rt_uses_gateway;
+
+	int			rt_iif;
+
+	u8			rt_gw_family;
+	/* Info on neighbour */
+	union {
+		__be32		rt_gw4;
+		struct in6_addr	rt_gw6;
+	};
+
+	/* Miscellaneous cached information */
+	u32			rt_mtu_locked:1,
+				rt_pmtu:31;
+
+	struct list_head	rt_uncached;
+	struct uncached_list	*rt_uncached_list;
+};
+
+static inline bool rt_is_input_route(const struct rtable *rt)
+{
+	return rt->rt_is_input != 0;
+}
+
+static inline bool rt_is_output_route(const struct rtable *rt)
+{
+	return rt->rt_is_input == 0;
+}
+
+static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr)
+{
+	if (rt->rt_gw_family == AF_INET)
+		return rt->rt_gw4;
+	return daddr;
+}
+
+struct ip_rt_acct {
+	__u32 	o_bytes;
+	__u32 	o_packets;
+	__u32 	i_bytes;
+	__u32 	i_packets;
+};
+
+struct rt_cache_stat {
+        unsigned int in_slow_tot;
+        unsigned int in_slow_mc;
+        unsigned int in_no_route;
+        unsigned int in_brd;
+        unsigned int in_martian_dst;
+        unsigned int in_martian_src;
+        unsigned int out_slow_tot;
+        unsigned int out_slow_mc;
+};
+
+extern struct ip_rt_acct __percpu *ip_rt_acct;
+
+struct in_device;
+
+int ip_rt_init(void);
+void rt_cache_flush(struct net *net);
+void rt_flush_dev(struct net_device *dev);
+struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp,
+					const struct sk_buff *skb);
+struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp,
+					    struct fib_result *res,
+					    const struct sk_buff *skb);
+
+static inline struct rtable *__ip_route_output_key(struct net *net,
+						   struct flowi4 *flp)
+{
+	return ip_route_output_key_hash(net, flp, NULL);
+}
+
+struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
+				    const struct sock *sk);
+struct rtable *ip_route_output_tunnel(struct sk_buff *skb,
+				      struct net_device *dev,
+				      struct net *net, __be32 *saddr,
+				      const struct ip_tunnel_info *info,
+				      u8 protocol, bool use_cache);
+
+struct dst_entry *ipv4_blackhole_route(struct net *net,
+				       struct dst_entry *dst_orig);
+
+static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp)
+{
+	return ip_route_output_flow(net, flp, NULL);
+}
+
+static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
+					     __be32 saddr, u8 tos, int oif)
+{
+	struct flowi4 fl4 = {
+		.flowi4_oif = oif,
+		.flowi4_tos = tos,
+		.daddr = daddr,
+		.saddr = saddr,
+	};
+	return ip_route_output_key(net, &fl4);
+}
+
+static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4,
+						   struct sock *sk,
+						   __be32 daddr, __be32 saddr,
+						   __be16 dport, __be16 sport,
+						   __u8 proto, __u8 tos, int oif)
+{
+	flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos,
+			   RT_SCOPE_UNIVERSE, proto,
+			   sk ? inet_sk_flowi_flags(sk) : 0,
+			   daddr, saddr, dport, sport, sock_net_uid(net, sk));
+	if (sk)
+		security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
+	return ip_route_output_flow(net, fl4, sk);
+}
+
+static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4,
+						 __be32 daddr, __be32 saddr,
+						 __be32 gre_key, __u8 tos, int oif)
+{
+	memset(fl4, 0, sizeof(*fl4));
+	fl4->flowi4_oif = oif;
+	fl4->daddr = daddr;
+	fl4->saddr = saddr;
+	fl4->flowi4_tos = tos;
+	fl4->flowi4_proto = IPPROTO_GRE;
+	fl4->fl4_gre_key = gre_key;
+	return ip_route_output_key(net, fl4);
+}
+int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+			  u8 tos, struct net_device *dev,
+			  struct in_device *in_dev, u32 *itag);
+int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
+			 u8 tos, struct net_device *devin);
+int ip_route_input_rcu(struct sk_buff *skb, __be32 dst, __be32 src,
+		       u8 tos, struct net_device *devin,
+		       struct fib_result *res);
+
+int ip_route_use_hint(struct sk_buff *skb, __be32 dst, __be32 src,
+		      u8 tos, struct net_device *devin,
+		      const struct sk_buff *hint);
+
+static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
+				 u8 tos, struct net_device *devin)
+{
+	int err;
+
+	rcu_read_lock();
+	err = ip_route_input_noref(skb, dst, src, tos, devin);
+	if (!err) {
+		skb_dst_force(skb);
+		if (!skb_dst(skb))
+			err = -EINVAL;
+	}
+	rcu_read_unlock();
+
+	return err;
+}
+
+void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,
+		      u8 protocol);
+void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);
+void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u8 protocol);
+void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk);
+void ip_rt_send_redirect(struct sk_buff *skb);
+
+unsigned int inet_addr_type(struct net *net, __be32 addr);
+unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);
+unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
+				__be32 addr);
+unsigned int inet_addr_type_dev_table(struct net *net,
+				      const struct net_device *dev,
+				      __be32 addr);
+void ip_rt_multicast_event(struct in_device *);
+int ip_rt_ioctl(struct net *, unsigned int cmd, struct rtentry *rt);
+void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt);
+struct rtable *rt_dst_alloc(struct net_device *dev,
+			     unsigned int flags, u16 type,
+			     bool nopolicy, bool noxfrm);
+struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt);
+
+struct in_ifaddr;
+void fib_add_ifaddr(struct in_ifaddr *);
+void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);
+void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric);
+
+void rt_add_uncached_list(struct rtable *rt);
+void rt_del_uncached_list(struct rtable *rt);
+
+int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
+		       u32 table_id, struct fib_info *fi,
+		       int *fa_index, int fa_start, unsigned int flags);
+
+static inline void ip_rt_put(struct rtable *rt)
+{
+	/* dst_release() accepts a NULL parameter.
+	 * We rely on dst being first structure in struct rtable
+	 */
+	BUILD_BUG_ON(offsetof(struct rtable, dst) != 0);
+	dst_release(&rt->dst);
+}
+
+#define IPTOS_RT_MASK	(IPTOS_TOS_MASK & ~3)
+
+extern const __u8 ip_tos2prio[16];
+
+static inline char rt_tos2priority(u8 tos)
+{
+	return ip_tos2prio[IPTOS_TOS(tos)>>1];
+}
+
+/* ip_route_connect() and ip_route_newports() work in tandem whilst
+ * binding a socket for a new outgoing connection.
+ *
+ * In order to use IPSEC properly, we must, in the end, have a
+ * route that was looked up using all available keys including source
+ * and destination ports.
+ *
+ * However, if a source port needs to be allocated (the user specified
+ * a wildcard source port) we need to obtain addressing information
+ * in order to perform that allocation.
+ *
+ * So ip_route_connect() looks up a route using wildcarded source and
+ * destination ports in the key, simply so that we can get a pair of
+ * addresses to use for port allocation.
+ *
+ * Later, once the ports are allocated, ip_route_newports() will make
+ * another route lookup if needed to make sure we catch any IPSEC
+ * rules keyed on the port information.
+ *
+ * The callers allocate the flow key on their stack, and must pass in
+ * the same flowi4 object to both the ip_route_connect() and the
+ * ip_route_newports() calls.
+ */
+
+static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src,
+					 u32 tos, int oif, u8 protocol,
+					 __be16 sport, __be16 dport,
+					 struct sock *sk)
+{
+	__u8 flow_flags = 0;
+
+	if (inet_sk(sk)->transparent)
+		flow_flags |= FLOWI_FLAG_ANYSRC;
+
+	flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
+			   protocol, flow_flags, dst, src, dport, sport,
+			   sk->sk_uid);
+}
+
+static inline struct rtable *ip_route_connect(struct flowi4 *fl4,
+					      __be32 dst, __be32 src, u32 tos,
+					      int oif, u8 protocol,
+					      __be16 sport, __be16 dport,
+					      struct sock *sk)
+{
+	struct net *net = sock_net(sk);
+	struct rtable *rt;
+
+	ip_route_connect_init(fl4, dst, src, tos, oif, protocol,
+			      sport, dport, sk);
+
+	if (!dst || !src) {
+		rt = __ip_route_output_key(net, fl4);
+		if (IS_ERR(rt))
+			return rt;
+		ip_rt_put(rt);
+		flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr);
+	}
+	security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
+	return ip_route_output_flow(net, fl4, sk);
+}
+
+static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt,
+					       __be16 orig_sport, __be16 orig_dport,
+					       __be16 sport, __be16 dport,
+					       struct sock *sk)
+{
+	if (sport != orig_sport || dport != orig_dport) {
+		fl4->fl4_dport = dport;
+		fl4->fl4_sport = sport;
+		ip_rt_put(rt);
+		flowi4_update_output(fl4, sk->sk_bound_dev_if,
+				     RT_CONN_FLAGS(sk), fl4->daddr,
+				     fl4->saddr);
+		security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
+		return ip_route_output_flow(sock_net(sk), fl4, sk);
+	}
+	return rt;
+}
+
+static inline int inet_iif(const struct sk_buff *skb)
+{
+	struct rtable *rt = skb_rtable(skb);
+
+	if (rt && rt->rt_iif)
+		return rt->rt_iif;
+
+	return skb->skb_iif;
+}
+
+static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
+{
+	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
+	struct net *net = dev_net(dst->dev);
+
+	if (hoplimit == 0)
+		hoplimit = net->ipv4.sysctl_ip_default_ttl;
+	return hoplimit;
+}
+
+static inline struct neighbour *ip_neigh_gw4(struct net_device *dev,
+					     __be32 daddr)
+{
+	struct neighbour *neigh;
+
+	neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)daddr);
+	if (unlikely(!neigh))
+		neigh = __neigh_create(&arp_tbl, &daddr, dev, false);
+
+	return neigh;
+}
+
+static inline struct neighbour *ip_neigh_for_gw(struct rtable *rt,
+						struct sk_buff *skb,
+						bool *is_v6gw)
+{
+	struct net_device *dev = rt->dst.dev;
+	struct neighbour *neigh;
+
+	if (likely(rt->rt_gw_family == AF_INET)) {
+		neigh = ip_neigh_gw4(dev, rt->rt_gw4);
+	} else if (rt->rt_gw_family == AF_INET6) {
+		neigh = ip_neigh_gw6(dev, &rt->rt_gw6);
+		*is_v6gw = true;
+	} else {
+		neigh = ip_neigh_gw4(dev, ip_hdr(skb)->daddr);
+	}
+	return neigh;
+}
+
+#endif	/* _ROUTE_H */