/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_ICMPV6_H
#define _LINUX_ICMPV6_H

#include <linux/skbuff.h>
#include <linux/ipv6.h>
#include <uapi/linux/icmpv6.h>

static inline struct icmp6hdr *icmp6_hdr(const struct sk_buff *skb)
{
        return (struct icmp6hdr *)skb_transport_header(skb);
}

#include <linux/netdevice.h>

#if IS_ENABLED(CONFIG_IPV6)

typedef void ip6_icmp_send_t(struct sk_buff *skb, u8 type, u8 code, __u32 info,
                             const struct in6_addr *force_saddr,
                             const struct inet6_skb_parm *parm);
void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
                const struct in6_addr *force_saddr,
                const struct inet6_skb_parm *parm);
#if IS_BUILTIN(CONFIG_IPV6)
static inline void __icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
                                 const struct inet6_skb_parm *parm)
{
        icmp6_send(skb, type, code, info, NULL, parm);
}
static inline int inet6_register_icmp_sender(ip6_icmp_send_t *fn)
{
        BUILD_BUG_ON(fn != icmp6_send);
        return 0;
}
static inline int inet6_unregister_icmp_sender(ip6_icmp_send_t *fn)
{
        BUILD_BUG_ON(fn != icmp6_send);
        return 0;
}
#else
extern void __icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
                          const struct inet6_skb_parm *parm);
extern int inet6_register_icmp_sender(ip6_icmp_send_t *fn);
extern int inet6_unregister_icmp_sender(ip6_icmp_send_t *fn);
#endif

static inline void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
{
        __icmpv6_send(skb, type, code, info, IP6CB(skb));
}

int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
                               unsigned int data_len);

#if IS_ENABLED(CONFIG_NF_NAT)
void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info);
#else
static inline void icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8 code, __u32 info)
{
        struct inet6_skb_parm parm = { 0 };
        __icmpv6_send(skb_in, type, code, info, &parm);
}
#endif

#else

static inline void icmpv6_send(struct sk_buff *skb,
                               u8 type, u8 code, __u32 info)
{
}

static inline void icmpv6_ndo_send(struct sk_buff *skb,
                                   u8 type, u8 code, __u32 info)
{
}
#endif

extern int                              icmpv6_init(void);
extern int                              icmpv6_err_convert(u8 type, u8 code,
                                                           int *err);
extern void                             icmpv6_cleanup(void);
extern void                             icmpv6_param_prob_reason(struct sk_buff *skb,
                                                                 u8 code, int pos,
                                                                 enum skb_drop_reason reason);

struct flowi6;
struct in6_addr;

void icmpv6_flow_init(const struct sock *sk, struct flowi6 *fl6, u8 type,
                      const struct in6_addr *saddr,
                      const struct in6_addr *daddr, int oif);

static inline void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
{
        icmpv6_param_prob_reason(skb, code, pos,
                                 SKB_DROP_REASON_NOT_SPECIFIED);
}

static inline bool icmpv6_is_err(int type)
{
        switch (type) {
        case ICMPV6_DEST_UNREACH:
        case ICMPV6_PKT_TOOBIG:
        case ICMPV6_TIME_EXCEED:
        case ICMPV6_PARAMPROB:
                return true;
        }

        return false;
}

#endif