path: root/include/net/ip_vs.h

/* SPDX-License-Identifier: GPL-2.0 */
/* IP Virtual Server
 * data structure and functionality definitions
 */

#ifndef _NET_IP_VS_H
#define _NET_IP_VS_H

#include <linux/ip_vs.h>                /* definitions shared with userland */

#include <asm/types.h>                  /* for __uXX types */

#include <linux/list.h>                 /* for struct list_head */
#include <linux/spinlock.h>             /* for struct rwlock_t */
#include <linux/atomic.h>               /* for struct atomic_t */
#include <linux/refcount.h>             /* for struct refcount_t */

#include <linux/compiler.h>
#include <linux/timer.h>
#include <linux/bug.h>

#include <net/checksum.h>
#include <linux/netfilter.h>		/* for union nf_inet_addr */
#include <linux/ip.h>
#include <linux/ipv6.h>			/* for struct ipv6hdr */
#include <net/ipv6.h>
#if IS_ENABLED(CONFIG_IP_VS_IPV6)
#include <linux/netfilter_ipv6/ip6_tables.h>
#endif
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
#include <net/netfilter/nf_conntrack.h>
#endif
#include <net/net_namespace.h>		/* Netw namespace */

#define IP_VS_HDR_INVERSE	1
#define IP_VS_HDR_ICMP		2

/* Generic access of ipvs struct */
static inline struct netns_ipvs *net_ipvs(struct net* net)
{
	return net->ipvs;
}

/* This one needed for single_open_net since net is stored directly in
 * private not as a struct i.e. seq_file_net can't be used.
 */
static inline struct net *seq_file_single_net(struct seq_file *seq)
{
#ifdef CONFIG_NET_NS
	return (struct net *)seq->private;
#else
	return &init_net;
#endif
}

/* Connections' size value needed by ip_vs_ctl.c */
extern int ip_vs_conn_tab_size;

struct ip_vs_iphdr {
	int hdr_flags;	/* ipvs flags */
	__u32 off;	/* Where IP or IPv4 header starts */
	__u32 len;	/* IPv4 simply where L4 starts
			 * IPv6 where L4 Transport Header starts */
	__u16 fragoffs; /* IPv6 fragment offset, 0 if first frag (or not frag)*/
	__s16 protocol;
	__s32 flags;
	union nf_inet_addr saddr;
	union nf_inet_addr daddr;
};

static inline void *frag_safe_skb_hp(const struct sk_buff *skb, int offset,
				      int len, void *buffer)
{
	return skb_header_pointer(skb, offset, len, buffer);
}

/* This function handles filling *ip_vs_iphdr, both for IPv4 and IPv6.
 * IPv6 requires some extra work, as finding proper header position,
 * depend on the IPv6 extension headers.
 */
static inline int
ip_vs_fill_iph_skb_off(int af, const struct sk_buff *skb, int offset,
		       int hdr_flags, struct ip_vs_iphdr *iphdr)
{
	iphdr->hdr_flags = hdr_flags;
	iphdr->off = offset;

#ifdef CONFIG_IP_VS_IPV6
	if (af == AF_INET6) {
		struct ipv6hdr _iph;
		const struct ipv6hdr *iph = skb_header_pointer(
			skb, offset, sizeof(_iph), &_iph);
		if (!iph)
			return 0;

		iphdr->saddr.in6 = iph->saddr;
		iphdr->daddr.in6 = iph->daddr;
		/* ipv6_find_hdr() updates len, flags */
		iphdr->len	 = offset;
		iphdr->flags	 = 0;
		iphdr->protocol  = ipv6_find_hdr(skb, &iphdr->len, -1,
						 &iphdr->fragoffs,
						 &iphdr->flags);
		if (iphdr->protocol < 0)
			return 0;
	} else
#endif
	{
		struct iphdr _iph;
		const struct iphdr *iph = skb_header_pointer(
			skb, offset, sizeof(_iph), &_iph);
		if (!iph)
			return 0;

		iphdr->len	= offset + iph->ihl * 4;
		iphdr->fragoffs	= 0;
		iphdr->protocol	= iph->protocol;
		iphdr->saddr.ip	= iph->saddr;
		iphdr->daddr.ip	= iph->daddr;
	}

	return 1;
}

static inline int
ip_vs_fill_iph_skb_icmp(int af, const struct sk_buff *skb, int offset,
			bool inverse, struct ip_vs_iphdr *iphdr)
{
	int hdr_flags = IP_VS_HDR_ICMP;

	if (inverse)
		hdr_flags |= IP_VS_HDR_INVERSE;

	return ip_