/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _IPV6_H
#define _IPV6_H

#include <uapi/linux/ipv6.h>
#include <linux/cache.h>

#define ipv6_optlen(p)  (((p)->hdrlen+1) << 3)
#define ipv6_authlen(p) (((p)->hdrlen+2) << 2)
/*
 * This structure contains configuration options per IPv6 link.
 */
struct ipv6_devconf {
        /* RX & TX fastpath fields. */
        __cacheline_group_begin(ipv6_devconf_read_txrx);
        __s32           disable_ipv6;
        __s32           hop_limit;
        __s32           mtu6;
        __s32           forwarding;
        __s32           force_forwarding;
        __s32           disable_policy;
        __s32           proxy_ndp;
        __cacheline_group_end(ipv6_devconf_read_txrx);

        __s32           accept_ra;
        __s32           accept_redirects;
        __s32           autoconf;
        __s32           dad_transmits;
        __s32           rtr_solicits;
        __s32           rtr_solicit_interval;
        __s32           rtr_solicit_max_interval;
        __s32           rtr_solicit_delay;
        __s32           force_mld_version;
        __s32           mldv1_unsolicited_report_interval;
        __s32           mldv2_unsolicited_report_interval;
        __s32           use_tempaddr;
        __s32           temp_valid_lft;
        __s32           temp_prefered_lft;
        __s32           regen_min_advance;
        __s32           regen_max_retry;
        __s32           max_desync_factor;
        __s32           max_addresses;
        __s32           accept_ra_defrtr;
        __u32           ra_defrtr_metric;
        __s32           accept_ra_min_hop_limit;
        __s32           accept_ra_min_lft;
        __s32           accept_ra_pinfo;
        __s32           ignore_routes_with_linkdown;
#ifdef CONFIG_IPV6_ROUTER_PREF
        __s32           accept_ra_rtr_pref;
        __s32           rtr_probe_interval;
#ifdef CONFIG_IPV6_ROUTE_INFO
        __s32           accept_ra_rt_info_min_plen;
        __s32           accept_ra_rt_info_max_plen;
#endif
#endif
        __s32           accept_source_route;
        __s32           accept_ra_from_local;
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
        __s32           optimistic_dad;
        __s32           use_optimistic;
#endif
#ifdef CONFIG_IPV6_MROUTE
        atomic_t        mc_forwarding;
#endif
        __s32           drop_unicast_in_l2_multicast;
        __s32           accept_dad;
        __s32           force_tllao;
        __s32           ndisc_notify;
        __s32           suppress_frag_ndisc;
        __s32           accept_ra_mtu;
        __s32           drop_unsolicited_na;
        __s32           accept_untracked_na;
        struct ipv6_stable_secret {
                bool initialized;
                struct in6_addr secret;
        } stable_secret;
        __s32           use_oif_addrs_only;
        __s32           keep_addr_on_down;
        __s32           seg6_enabled;
#ifdef CONFIG_IPV6_SEG6_HMAC
        __s32           seg6_require_hmac;
#endif
        __u32           enhanced_dad;
        __u32           addr_gen_mode;
        __s32           ndisc_tclass;
        __s32           rpl_seg_enabled;
        __u32           ioam6_id;
        __u32           ioam6_id_wide;
        __u8            ioam6_enabled;
        __u8            ndisc_evict_nocarrier;
        __u8            ra_honor_pio_life;
        __u8            ra_honor_pio_pflag;

        struct ctl_table_header *sysctl_header;
};

struct ipv6_params {
        __s32 disable_ipv6;
        __s32 autoconf;
};
extern struct ipv6_params ipv6_defaults;
#include <linux/tcp.h>
#include <linux/udp.h>

#include <net/inet_sock.h>

static inline struct ipv6hdr *ipv6_hdr(const struct sk_buff *skb)
{
        return (struct ipv6hdr *)skb_network_header(skb);
}

static inline struct ipv6hdr *inner_ipv6_hdr(const struct sk_buff *skb)
{
        return (struct ipv6hdr *)skb_inner_network_header(skb);
}

static inline struct ipv6hdr *ipipv6_hdr(const struct sk_buff *skb)
{
        return (struct ipv6hdr *)skb_transport_header(skb);
}

static inline unsigned int ipv6_transport_len(const struct sk_buff *skb)
{
        return ntohs(ipv6_hdr(skb)->payload_len) + sizeof(struct ipv6hdr) -
               skb_network_header_len(skb);
}

static inline unsigned int
ipv6_payload_len(const struct sk_buff *skb, const struct ipv6hdr *ip6)
{
        u32 len = ntohs(ip6->payload_len);

        return (len || !skb_is_gso(skb) || !skb_is_gso_tcp(skb)) ?
                len :
                skb->len - skb_network_offset(skb) - sizeof(struct ipv6hdr);
}

static inline unsigned int skb_ipv6_payload_len(const struct sk_buff *skb)
{
        return ipv6_payload_len(skb, ipv6_hdr(skb));
}

#define IPV6_MAXPLEN            65535

static inline void ipv6_set_payload_len(struct ipv6hdr *ip6, unsigned int len)
{
        ip6->payload_len = len <= IPV6_MAXPLEN ? htons(len) : 0;
}

/* 
   This structure contains results of exthdrs parsing
   as offsets from skb->nh.
 */

struct inet6_skb_parm {
        int                     iif;
        __be16                  ra;
        __u16                   dst0;
        __u16                   srcrt;
        __u16                   dst1;
        __u16                   lastopt;
        __u16                   nhoff;
        __u16                   flags;
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
        __u16                   dsthao;
#endif
        __u16                   frag_max_size;
        __u16                   srhoff;

#define IP6SKB_XFRM_TRANSFORMED 1
#define IP6SKB_FORWARDED        2
#define IP6SKB_REROUTED         4
#define IP6SKB_ROUTERALERT      8
#define IP6SKB_FRAGMENTED      16
#define IP6SKB_HOPBYHOP        32
#define IP6SKB_L3SLAVE         64
#define IP6SKB_JUMBOGRAM      128
#define IP6SKB_SEG6           256
#define IP6SKB_MULTIPATH      1024
#define IP6SKB_MCROUTE        2048
};

#if defined(CONFIG_NET_L3_MASTER_DEV)
static inline bool ipv6_l3mdev_skb(__u16 flags)
{
        return flags & IP6SKB_L3SLAVE;
}
#else
static inline bool ipv6_l3mdev_skb(__u16 flags)
{
        return false;
}
#endif

#define IP6CB(skb)      ((struct inet6_skb_parm*)((skb)->cb))
#define IP6CBMTU(skb)   ((struct ip6_mtuinfo *)((skb)->cb))

static inline int inet6_iif(const struct sk_buff *skb)
{
        bool l3_slave = ipv6_l3mdev_skb(IP6CB(skb)->flags);

        return l3_slave ? skb->skb_iif : IP6CB(skb)->iif;
}

static inline bool inet6_is_jumbogram(const struct sk_buff *skb)
{
        return !!(IP6CB(skb)->flags & IP6SKB_JUMBOGRAM);
}

/* can not be used in TCP layer after tcp_v6_fill_cb */
static inline int inet6_sdif(const struct sk_buff *skb)
{
#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
        if (skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
                return IP6CB(skb)->iif;
#endif
        return 0;
}

struct tcp6_request_sock {
        struct tcp_request_sock   tcp6rsk_tcp;
};

struct ipv6_mc_socklist;
struct ipv6_ac_socklist;
struct ipv6_fl_socklist;

/* struct ipv6_pinfo - ipv6 private area */
struct ipv6_pinfo {
        /* Used in tx path (inet6_csk_route_socket(), ip6_xmit()) */
        struct in6_addr         saddr;
        union {
                struct in6_addr daddr;
                struct in6_addr final;
        };
        __be32                  flow_label;
        u32                     dst_cookie;
        struct ipv6_txoptions __rcu     *opt;
        s16                     hop_limit;
        u8                      pmtudisc;
        u8                      tclass;
#ifdef CONFIG_IPV6_SUBTREES
        bool                    saddr_cache;
#endif
        bool                    daddr_cache;

        u8                      mcast_hops;
        u32                     frag_size;

        int                     ucast_oif;
        int                     mcast_oif;

        /* pktoption flags */
        union {
                struct {
                        u16     srcrt:1,
                                osrcrt:1,
                                rxinfo:1,
                                rxoinfo:1,
                                rxhlim:1,
                                rxohlim:1,
                                hopopts:1,
                                ohopopts:1,
                                dstopts:1,
                                odstopts:1,
                                rxflow:1,
                                rxtclass:1,
                                rxpmtu:1,
                                rxorigdstaddr:1,
                                recvfragsize:1;
                                /* 1 bits hole */
                } bits;
                u16             all;
        } rxopt;

        /* sockopt flags */
        u8                      srcprefs;       /* 001: prefer temporary address
                                                 * 010: prefer public address
                                                 * 100: prefer care-of address
                                                 */
        u8                      min_hopcount;
        __be32                  rcv_flowinfo;
        struct in6_pktinfo      sticky_pktinfo;

        struct sk_buff          *pktoptions;
        struct sk_buff          *rxpmtu;

        struct ipv6_mc_socklist __rcu *ipv6_mc_list;
        struct ipv6_ac_socklist *ipv6_ac_list;
};

/* We currently use available bits from inet_sk(sk)->inet_flags,
 * this could change in the future.
 */
#define inet6_test_bit(nr, sk)                  \
        test_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
#define inet6_set_bit(nr, sk)                   \
        set_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
#define inet6_clear_bit(nr, sk)                 \
        clear_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags)
#define inet6_assign_bit(nr, sk, val)           \
        assign_bit(INET_FLAGS_##nr, &inet_sk(sk)->inet_flags, val)

/* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
struct raw6_sock {
        /* inet_sock has to be the first member of raw6_sock */
        struct inet_sock        inet;
        __u32                   checksum;       /* perform checksum */
        __u32                   offset;         /* checksum offset  */
        struct icmp6_filter     filter;
        __u32                   ip6mr_table;
        struct numa_drop_counters drop_counters;
        struct ipv6_pinfo       inet6;
};

struct udp6_sock {
        struct udp_sock   udp;

        struct ipv6_pinfo inet6;
};

struct tcp6_sock {
        struct tcp_sock   tcp;

        struct ipv6_pinfo inet6;
};

extern int inet6_sk_rebuild_header(struct sock *sk);

struct tcp6_timewait_sock {
        struct tcp_timewait_sock   tcp6tw_tcp;
};

#if IS_ENABLED(CONFIG_IPV6)
extern int disable_ipv6_mod;

static inline bool ipv6_mod_enabled(void)
{
        return disable_ipv6_mod == 0;
}

static inline struct ipv6_pinfo *inet6_sk(const struct sock *__sk)
{
        return sk_fullsock(__sk) ? inet_sk(__sk)->pinet6 : NULL;
}

#define raw6_sk(ptr) container_of_const(ptr, struct raw6_sock, inet.sk)

#define ipv6_only_sock(sk)      (sk->sk_ipv6only)
#define ipv6_sk_rxinfo(sk)      ((sk)->sk_family == PF_INET6 && \
                                 inet6_sk(sk)->rxopt.bits.rxinfo)

static inline const struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
{
        if (sk->sk_family == AF_INET6)
                return &sk->sk_v6_rcv_saddr;
        return NULL;
}

static inline int inet_v6_ipv6only(const struct sock *sk)
{
        /* ipv6only field is at same position for timewait and other sockets */
        return ipv6_only_sock(sk);
}
#else
#define ipv6_only_sock(sk)      0
#define ipv6_sk_rxinfo(sk)      0

static inline bool ipv6_mod_enabled(void)
{
        return false;
}

static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
{
        return NULL;
}

static inline struct raw6_sock *raw6_sk(const struct sock *sk)
{
        return NULL;
}

#define inet6_rcv_saddr(__sk)   NULL
#define inet_v6_ipv6only(__sk)          0
#endif /* IS_ENABLED(CONFIG_IPV6) */
#endif /* _IPV6_H */