Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 778 insertions, 0 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
new file mode 100644
index 000000000..9be2efe00
--- /dev/null
+++ b/include/net/ip.h
@@ -0,0 +1,778 @@
+/* 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 module.
+ *
+ * Version:	@(#)ip.h	1.0.2	05/07/93
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *
+ * Changes:
+ *		Mike McLagan    :       Routing by source
+ */
+#ifndef _IP_H
+#define _IP_H
+
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/skbuff.h>
+#include <linux/jhash.h>
+#include <linux/sockptr.h>
+
+#include <net/inet_sock.h>
+#include <net/route.h>
+#include <net/snmp.h>
+#include <net/flow.h>
+#include <net/flow_dissector.h>
+#include <net/netns/hash.h>
+#include <net/lwtunnel.h>
+
+#define IPV4_MAX_PMTU		65535U		/* RFC 2675, Section 5.1 */
+#define IPV4_MIN_MTU		68			/* RFC 791 */
+
+extern unsigned int sysctl_fib_sync_mem;
+extern unsigned int sysctl_fib_sync_mem_min;
+extern unsigned int sysctl_fib_sync_mem_max;
+
+struct sock;
+
+struct inet_skb_parm {
+	int			iif;
+	struct ip_options	opt;		/* Compiled IP options		*/
+	u16			flags;
+
+#define IPSKB_FORWARDED		BIT(0)
+#define IPSKB_XFRM_TUNNEL_SIZE	BIT(1)
+#define IPSKB_XFRM_TRANSFORMED	BIT(2)
+#define IPSKB_FRAG_COMPLETE	BIT(3)
+#define IPSKB_REROUTED		BIT(4)
+#define IPSKB_DOREDIRECT	BIT(5)
+#define IPSKB_FRAG_PMTU		BIT(6)
+#define IPSKB_L3SLAVE		BIT(7)
+#define IPSKB_NOPOLICY		BIT(8)
+#define IPSKB_MULTIPATH		BIT(9)
+
+	u16			frag_max_size;
+};
+
+static inline bool ipv4_l3mdev_skb(u16 flags)
+{
+	return !!(flags & IPSKB_L3SLAVE);
+}
+
+static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
+{
+	return ip_hdr(skb)->ihl * 4;
+}
+
+struct ipcm_cookie {
+	struct sockcm_cookie	sockc;
+	__be32			addr;
+	int			oif;
+	struct ip_options_rcu	*opt;
+	__u8			protocol;
+	__u8			ttl;
+	__s16			tos;
+	char			priority;
+	__u16			gso_size;
+};
+
+static inline void ipcm_init(struct ipcm_cookie *ipcm)
+{
+	*ipcm = (struct ipcm_cookie) { .tos = -1 };
+}
+
+static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
+				const struct inet_sock *inet)
+{
+	ipcm_init(ipcm);
+
+	ipcm->sockc.mark = inet->sk.sk_mark;
+	ipcm->sockc.tsflags = inet->sk.sk_tsflags;
+	ipcm->oif = inet->sk.sk_bound_dev_if;
+	ipcm->addr = inet->inet_saddr;
+	ipcm->protocol = inet->inet_num;
+}
+
+#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
+#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
+
+/* return enslaved device index if relevant */
+static inline int inet_sdif(struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+	if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
+		return IPCB(skb)->iif;
+#endif
+	return 0;
+}
+
+/* Special input handler for packets caught by router alert option.
+   They are selected only by protocol field, and then processed likely
+   local ones; but only if someone wants them! Otherwise, router
+   not running rsvpd will kill RSVP.
+
+   It is user level problem, what it will make with them.
+   I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
+   but receiver should be enough clever f.e. to forward mtrace requests,
+   sent to multicast group to reach destination designated router.
+ */
+
+struct ip_ra_chain {
+	struct ip_ra_chain __rcu *next;
+	struct sock		*sk;
+	union {
+		void			(*destructor)(struct sock *);
+		struct sock		*saved_sk;
+	};
+	struct rcu_head		rcu;
+};
+
+/* IP flags. */
+#define IP_CE		0x8000		/* Flag: "Congestion"		*/
+#define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
+#define IP_MF		0x2000		/* Flag: "More Fragments"	*/
+#define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
+
+#define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
+
+struct msghdr;
+struct net_device;
+struct packet_type;
+struct rtable;
+struct sockaddr;
+
+int igmp_mc_init(void);
+
+/*
+ *	Functions provided by ip.c
+ */
+
+int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
+			  __be32 saddr, __be32 daddr,
+			  struct ip_options_rcu *opt, u8 tos);
+int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
+	   struct net_device *orig_dev);
+void ip_list_rcv(struct list_head *head, struct packet_type *pt,
+		 struct net_device *orig_dev);
+int ip_local_deliver(struct sk_buff *skb);
+void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
+int ip_mr_input(struct sk_buff *skb);
+int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
+int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
+int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
+		   int (*output)(struct net *, struct sock *, struct sk_buff *));
+
+struct ip_fraglist_iter {
+	struct sk_buff	*frag;
+	struct iphdr	*iph;
+	int		offset;
+	unsigned int	hlen;
+};
+
+void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
+		      unsigned int hlen, struct ip_fraglist_iter *iter);
+void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
+
+static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter)
+{
+	struct sk_buff *skb = iter->frag;
+
+	iter->frag = skb->next;
+	skb_mark_not_on_list(skb);
+
+	return skb;
+}
+
+struct ip_frag_state {
+	bool		DF;
+	unsigned int	hlen;
+	unsigned int	ll_rs;
+	unsigned int	mtu;
+	unsigned int	left;
+	int		offset;
+	int		ptr;
+	__be16		not_last_frag;
+};
+
+void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs,
+		  unsigned int mtu, bool DF, struct ip_frag_state *state);
+struct sk_buff *ip_frag_next(struct sk_buff *skb,
+			     struct ip_frag_state *state);
+
+void ip_send_check(struct iphdr *ip);
+int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
+int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
+
+int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
+		    __u8 tos);
+void ip_init(void);
+int ip_append_data(struct sock *sk, struct flowi4 *fl4,
+		   int getfrag(void *from, char *to, int offset, int len,
+			       int odd, struct sk_buff *skb),
+		   void *from, int len, int protolen,
+		   struct ipcm_cookie *ipc,
+		   struct rtable **rt,
+		   unsigned int flags);
+int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
+		       struct sk_buff *skb);
+ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
+		       int offset, size_t size, int flags);
+struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
+			      struct sk_buff_head *queue,
+			      struct inet_cork *cork);
+int ip_send_skb(struct net *net, struct sk_buff *skb);
+int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
+void ip_flush_pending_frames(struct sock *sk);
+struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
+			    int getfrag(void *from, char *to, int offset,
+					int len, int odd, struct sk_buff *skb),
+			    void *from, int length, int transhdrlen,
+			    struct ipcm_cookie *ipc, struct rtable **rtp,
+			    struct inet_cork *cork, unsigned int flags);
+
+int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
+
+static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
+{
+	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
+}
+
+static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
+{
+	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
+}
+
+static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
+{
+	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
+}
+
+/* datagram.c */
+int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
+int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
+
+void ip4_datagram_release_cb(struct sock *sk);
+
+struct ip_reply_arg {
+	struct kvec iov[1];
+	int	    flags;
+	__wsum 	    csum;
+	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
+				/* -1 if not needed */
+	int	    bound_dev_if;
+	u8  	    tos;
+	kuid_t	    uid;
+};
+
+#define IP_REPLY_ARG_NOSRCCHECK 1
+
+static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
+{
+	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
+}
+
+void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
+			   const struct ip_options *sopt,
+			   __be32 daddr, __be32 saddr,
+			   const struct ip_reply_arg *arg,
+			   unsigned int len, u64 transmit_time);
+
+#define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
+#define __IP_INC_STATS(net, field)	__SNMP_INC_STATS64((net)->mib.ip_statistics, field)
+#define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
+#define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
+#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
+#define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
+#define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
+#define __NET_INC_STATS(net, field)	__SNMP_INC_STATS((net)->mib.net_statistics, field)
+#define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
+#define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
+
+u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
+unsigned long snmp_fold_field(void __percpu *mib, int offt);
+#if BITS_PER_LONG==32
+u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+			 size_t syncp_offset);
+u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
+#else
+static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+					size_t syncp_offset)
+{
+	return snmp_get_cpu_field(mib, cpu, offct);
+
+}
+
+static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
+{
+	return snmp_fold_field(mib, offt);
+}
+#endif
+
+#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
+{ \
+	int i, c; \
+	for_each_possible_cpu(c) { \
+		for (i = 0; stats_list[i].name; i++) \
+			buff64[i] += snmp_get_cpu_field64( \
+					mib_statistic, \
+					c, stats_list[i].entry, \
+					offset); \
+	} \
+}
+
+#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
+{ \
+	int i, c; \
+	for_each_possible_cpu(c) { \
+		for (i = 0; stats_list[i].name; i++) \
+			buff[i] += snmp_get_cpu_field( \
+						mib_statistic, \
+						c, stats_list[i].entry); \
+	} \
+}
+
+void inet_get_local_port_range(struct net *net, int *low, int *high);
+
+#ifdef CONFIG_SYSCTL
+static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
+{
+	if (!net->ipv4.sysctl_local_reserved_ports)
+		return false;
+	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
+}
+
+static inline bool sysctl_dev_name_is_allowed(const char *name)
+{
+	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
+}
+
+static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
+{
+	return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
+}
+
+#else
+static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
+{
+	return false;
+}
+
+static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
+{
+	return port < PROT_SOCK;
+}
+#endif
+
+__be32 inet_current_timestamp(void);
+
+/* From inetpeer.c */
+extern int inet_peer_threshold;
+extern int inet_peer_minttl;
+extern int inet_peer_maxttl;
+
+void ipfrag_init(void);
+
+void ip_static_sysctl_init(void);
+
+#define IP4_REPLY_MARK(net, mark) \
+	(READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0)
+
+static inline bool ip_is_fragment(const struct iphdr *iph)
+{
+	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
+}
+
+#ifdef CONFIG_INET
+#include <net/dst.h>
+
+/* The function in 2.2 was invalid, producing wrong result for
+ * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
+static inline
+int ip_decrease_ttl(struct iphdr *iph)
+{
+	u32 check = (__force u32)iph->check;
+	check += (__force u32)htons(0x0100);
+	iph->check = (__force __sum16)(check + (check>=0xFFFF));
+	return --iph->ttl;
+}
+
+static inline int ip_mtu_locked(const struct dst_entry *dst)
+{
+	const struct rtable *rt = (const struct rtable *)dst;
+
+	return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
+}
+
+static inline
+int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
+{
+	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
+
+	return  pmtudisc == IP_PMTUDISC_DO ||
+		(pmtudisc == IP_PMTUDISC_WANT &&
+		 !ip_mtu_locked(dst));
+}
+
+static inline bool ip_sk_accept_pmtu(const struct sock *sk)
+{
+	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
+	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
+}
+
+static inline bool ip_sk_use_pmtu(const struct sock *sk)
+{
+	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
+}
+
+static inline bool ip_sk_ignore_df(const struct sock *sk)
+{
+	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
+	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
+}
+
+static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
+						    bool forwarding)
+{
+	struct net *net = dev_net(dst->dev);
+	unsigned int mtu;
+
+	if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) ||
+	    ip_mtu_locked(dst) ||
+	    !forwarding)
+		return dst_mtu(dst);
+
+	/* 'forwarding = true' case should always honour route mtu */
+	mtu = dst_metric_raw(dst, RTAX_MTU);
+	if (!mtu)
+		mtu = min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
+
+	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
+}
+
+static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
+					  const struct sk_buff *skb)
+{
+	unsigned int mtu;
+
+	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
+		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
+
+		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
+	}
+
+	mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
+	return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu);
+}
+
+struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
+					int fc_mx_len,
+					struct netlink_ext_ack *extack);
+static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
+{
+	if (fib_metrics != &dst_default_metrics &&
+	    refcount_dec_and_test(&fib_metrics->refcnt))
+		kfree(fib_metrics);
+}
+
+/* ipv4 and ipv6 both use refcounted metrics if it is not the default */
+static inline
+void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
+{
+	dst_init_metrics(dst, fib_metrics->metrics, true);
+
+	if (fib_metrics != &dst_default_metrics) {
+		dst->_metrics |= DST_METRICS_REFCOUNTED;
+		refcount_inc(&fib_metrics->refcnt);
+	}
+}
+
+static inline
+void ip_dst_metrics_put(struct dst_entry *dst)
+{
+	struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
+
+	if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
+		kfree(p);
+}
+
+u32 ip_idents_reserve(u32 hash, int segs);
+void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
+
+static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
+					struct sock *sk, int segs)
+{
+	struct iphdr *iph = ip_hdr(skb);
+
+	/* We had many attacks based on IPID, use the private
+	 * generator as much as we can.
+	 */
+	if (sk && inet_sk(sk)->inet_daddr) {
+		iph->id = htons(inet_sk(sk)->inet_id);
+		inet_sk(sk)->inet_id += segs;
+		return;
+	}
+	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
+		iph->id = 0;
+	} else {
+		/* Unfortunately we need the big hammer to get a suitable IPID */
+		__ip_select_ident(net, iph, segs);
+	}
+}
+
+static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
+				   struct sock *sk)
+{
+	ip_select_ident_segs(net, skb, sk, 1);
+}
+
+static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
+				  skb->len, proto, 0);
+}
+
+/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
+ * Equivalent to :	flow->v4addrs.src = iph->saddr;
+ *			flow->v4addrs.dst = iph->daddr;
+ */
+static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
+					    const struct iphdr *iph)
+{
+	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
+		     offsetof(typeof(flow->addrs), v4addrs.src) +
+			      sizeof(flow->addrs.v4addrs.src));
+	memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs));
+	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
+}
+
+static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	const struct iphdr *iph = skb_gro_network_header(skb);
+
+	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
+				  skb_gro_len(skb), proto, 0);
+}
+
+/*
+ *	Map a multicast IP onto multicast MAC for type ethernet.
+ */
+
+static inline void ip_eth_mc_map(__be32 naddr, char *buf)
+{
+	__u32 addr=ntohl(naddr);
+	buf[0]=0x01;
+	buf[1]=0x00;
+	buf[2]=0x5e;
+	buf[5]=addr&0xFF;
+	addr>>=8;
+	buf[4]=addr&0xFF;
+	addr>>=8;
+	buf[3]=addr&0x7F;
+}
+
+/*
+ *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
+ *	Leave P_Key as 0 to be filled in by driver.
+ */
+
+static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
+{
+	__u32 addr;
+	unsigned char scope = broadcast[5] & 0xF;
+
+	buf[0]  = 0;		/* Reserved */
+	buf[1]  = 0xff;		/* Multicast QPN */
+	buf[2]  = 0xff;
+	buf[3]  = 0xff;
+	addr    = ntohl(naddr);
+	buf[4]  = 0xff;
+	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
+	buf[6]  = 0x40;		/* IPv4 signature */
+	buf[7]  = 0x1b;
+	buf[8]  = broadcast[8];		/* P_Key */
+	buf[9]  = broadcast[9];
+	buf[10] = 0;
+	buf[11] = 0;
+	buf[12] = 0;
+	buf[13] = 0;
+	buf[14] = 0;
+	buf[15] = 0;
+	buf[19] = addr & 0xff;
+	addr  >>= 8;
+	buf[18] = addr & 0xff;
+	addr  >>= 8;
+	buf[17] = addr & 0xff;
+	addr  >>= 8;
+	buf[16] = addr & 0x0f;
+}
+
+static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
+{
+	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
+		memcpy(buf, broadcast, 4);
+	else
+		memcpy(buf, &naddr, sizeof(naddr));
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <linux/ipv6.h>
+#endif
+
+static __inline__ void inet_reset_saddr(struct sock *sk)
+{
+	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == PF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
+
+		memset(&np->saddr, 0, sizeof(np->saddr));
+		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
+	}
+#endif
+}
+
+#endif
+
+static inline unsigned int ipv4_addr_hash(__be32 ip)
+{
+	return (__force unsigned int) ip;
+}
+
+static inline u32 ipv4_portaddr_hash(const struct net *net,
+				     __be32 saddr,
+				     unsigned int port)
+{
+	return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
+}
+
+bool ip_call_ra_chain(struct sk_buff *skb);
+
+/*
+ *	Functions provided by ip_fragment.c
+ */
+
+enum ip_defrag_users {
+	IP_DEFRAG_LOCAL_DELIVER,
+	IP_DEFRAG_CALL_RA_CHAIN,
+	IP_DEFRAG_CONNTRACK_IN,
+	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
+	IP_DEFRAG_CONNTRACK_OUT,
+	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
+	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
+	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
+	IP_DEFRAG_VS_IN,
+	IP_DEFRAG_VS_OUT,
+	IP_DEFRAG_VS_FWD,
+	IP_DEFRAG_AF_PACKET,
+	IP_DEFRAG_MACVLAN,
+};
+
+/* Return true if the value of 'user' is between 'lower_bond'
+ * and 'upper_bond' inclusively.
+ */
+static inline bool ip_defrag_user_in_between(u32 user,
+					     enum ip_defrag_users lower_bond,
+					     enum ip_defrag_users upper_bond)
+{
+	return user >= lower_bond && user <= upper_bond;
+}
+
+int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
+#ifdef CONFIG_INET
+struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
+#else
+static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
+{
+	return skb;
+}
+#endif
+
+/*
+ *	Functions provided by ip_forward.c
+ */
+
+int ip_forward(struct sk_buff *skb);
+
+/*
+ *	Functions provided by ip_options.c
+ */
+
+void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
+		      __be32 daddr, struct rtable *rt, int is_frag);
+
+int __ip_options_echo(struct net *net, struct ip_options *dopt,
+		      struct sk_buff *skb, const struct ip_options *sopt);
+static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
+				  struct sk_buff *skb)
+{
+	return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
+}
+
+void ip_options_fragment(struct sk_buff *skb);
+int __ip_options_compile(struct net *net, struct ip_options *opt,
+			 struct sk_buff *skb, __be32 *info);
+int ip_options_compile(struct net *net, struct ip_options *opt,
+		       struct sk_buff *skb);
+int ip_options_get(struct net *net, struct ip_options_rcu **optp,
+		   sockptr_t data, int optlen);
+void ip_options_undo(struct ip_options *opt);
+void ip_forward_options(struct sk_buff *skb);
+int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
+
+/*
+ *	Functions provided by ip_sockglue.c
+ */
+
+void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
+void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
+			 struct sk_buff *skb, int tlen, int offset);
+int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
+		 struct ipcm_cookie *ipc, bool allow_ipv6);
+int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
+		  unsigned int optlen);
+int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
+		  int __user *optlen);
+int ip_ra_control(struct sock *sk, unsigned char on,
+		  void (*destructor)(struct sock *));
+
+int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
+void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
+		   u32 info, u8 *payload);
+void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
+		    u32 info);
+
+static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
+{
+	ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
+}
+
+bool icmp_global_allow(void);
+extern int sysctl_icmp_msgs_per_sec;
+extern int sysctl_icmp_msgs_burst;
+
+#ifdef CONFIG_PROC_FS
+int ip_misc_proc_init(void);
+#endif
+
+int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
+				struct netlink_ext_ack *extack);
+
+static inline bool inetdev_valid_mtu(unsigned int mtu)
+{
+	return likely(mtu >= IPV4_MIN_MTU);
+}
+
+void ip_sock_set_freebind(struct sock *sk);
+int ip_sock_set_mtu_discover(struct sock *sk, int val);
+void ip_sock_set_pktinfo(struct sock *sk);
+void ip_sock_set_recverr(struct sock *sk);
+void ip_sock_set_tos(struct sock *sk, int val);
+
+#endif	/* _IP_H */