/*
 * 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 inet_sock
 *
 * Authors:     Many, reorganised here by
 *              Arnaldo Carvalho de Melo <acme@mandriva.com>
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 */
#ifndef _INET_SOCK_H
#define _INET_SOCK_H


#include <linux/kmemcheck.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/jhash.h>
#include <linux/netdevice.h>

#include <net/flow.h>
#include <net/sock.h>
#include <net/request_sock.h>
#include <net/netns/hash.h>

/** struct ip_options - IP Options
 *
 * @faddr - Saved first hop address
 * @nexthop - Saved nexthop address in LSRR and SSRR
 * @is_data - Options in __data, rather than skb
 * @is_strictroute - Strict source route
 * @srr_is_hit - Packet destination addr was our one
 * @is_changed - IP checksum more not valid
 * @rr_needaddr - Need to record addr of outgoing dev
 * @ts_needtime - Need to record timestamp
 * @ts_needaddr - Need to record addr of outgoing dev
 */
struct ip_options {
        __be32          faddr;
        __be32          nexthop;
        unsigned char   optlen;
        unsigned char   srr;
        unsigned char   rr;
        unsigned char   ts;
        unsigned char   is_strictroute:1,
                        srr_is_hit:1,
                        is_changed:1,
                        rr_needaddr:1,
                        ts_needtime:1,
                        ts_needaddr:1;
        unsigned char   router_alert;
        unsigned char   cipso;
        unsigned char   __pad2;
        unsigned char   __data[0];
};

struct ip_options_rcu {
        struct rcu_head rcu;
        struct ip_options opt;
};

struct ip_options_data {
        struct ip_options_rcu   opt;
        char                    data[40];
};

struct inet_request_sock {
        struct request_sock     req;
#if IS_ENABLED(CONFIG_IPV6)
        u16                     inet6_rsk_offset;
#endif
        __be16                  loc_port;
        __be32                  loc_addr;
        __be32                  rmt_addr;
        __be16                  rmt_port;
        kmemcheck_bitfield_begin(flags);
        u16                     snd_wscale : 4,
                                rcv_wscale : 4,
                                tstamp_ok  : 1,
                                sack_ok    : 1,
                                wscale_ok  : 1,
                                ecn_ok     : 1,
                                acked      : 1,
                                no_srccheck: 1;
        kmemcheck_bitfield_end(flags);
        struct ip_options_rcu   *opt;
};

static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
{
        return (struct inet_request_sock *)sk;
}

struct inet_cork {
        unsigned int            flags;
        __be32                  addr;
        struct ip_options       *opt;
        unsigned int            fragsize;
        struct dst_entry        *dst;
        int                     length; /* Total length of all frames */
        struct page             *page;
        u32                     off;
        u8                      tx_flags;
};

struct inet_cork_full {
        struct inet_cork        base;
        struct flowi            fl;
};

struct ip_mc_socklist;
struct ipv6_pinfo;
struct rtable;

/** struct inet_sock - representation of INET sockets
 *
 * @sk - ancestor class
 * @pinet6 - pointer to IPv6 control block
 * @inet_daddr - Foreign IPv4 addr
 * @inet_rcv_saddr - Bound local IPv4 addr
 * @inet_dport - Destination port
 * @inet_num - Local port
 * @inet_saddr - Sending source
 * @uc_ttl - Unicast TTL
 * @inet_sport - Source port
 * @inet_id - ID counter for DF pkts
 * @tos - TOS
 * @mc_ttl - Multicasting TTL
 * @is_icsk - is this an inet_connection_sock?
 * @uc_index - Unicast outgoing device index
 * @mc_index - Multicast device index
 * @mc_list - Group array
 * @cork - info to build ip hdr on each ip frag while socket is corked
 */
struct inet_sock {
        /* sk and pinet6 has to be the first two members of inet_sock */
        struct sock             sk;
#if IS_ENABLED(CONFIG_IPV6)
        struct ipv6_pinfo       *pinet6;
#endif
        /* Socket demultiplex comparisons on incoming packets. */
#define inet_daddr              sk.__sk_common.skc_daddr
#define inet_rcv_saddr          sk.__sk_common.skc_rcv_saddr

        __be16                  inet_dport;
        __u16                   inet_num;
        __be32                  inet_saddr;
        __s16                   uc_ttl;
        __u16                   cmsg_flags;
        __be16                  inet_sport;
        __u16                   inet_id;

        struct ip_options_rcu __rcu     *inet_opt;
        __u8                    tos;
        __u8                    min_ttl;
        __u8                    mc_ttl;
        __u8                    pmtudisc;
        __u8                    recverr:1,
                                is_icsk:1,
                                freebind:1,
                                hdrincl:1,
                                mc_loop:1,
                                transparent:1,
                                mc_all:1,
                                nodefrag:1;
        __u8                    rcv_tos;
        int                     uc_index;
        int                     mc_index;
        __be32                  mc_addr;
        int                     rx_dst_ifindex;
        struct ip_mc_socklist __rcu     *mc_list;
        struct inet_cork_full   cork;
};

#define IPCORK_OPT      1       /* ip-options has been held in ipcork.opt */
#define IPCORK_ALLFRAG  2       /* always fragment (for ipv6 for now) */

static inline struct inet_sock *inet_sk(const struct sock *sk)
{
        return (struct inet_sock *)sk;
}

static inline void __inet_sk_copy_descendant(struct sock *sk_to,
                                             const struct sock *sk_from,
                                             const int ancestor_size)
{
        memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
               sk_from->sk_prot->obj_size - ancestor_size);
}
#if !(IS_ENABLED(CONFIG_IPV6))
static inline void inet_sk_copy_descendant(struct sock *sk_to,
                                           const struct sock *sk_from)
{
        __inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
}
#endif

extern int inet_sk_rebuild_header(struct sock *sk);

extern u32 inet_ehash_secret;
extern void build_ehash_secret(void);

static inline unsigned int inet_ehashfn(struct net *net,
                                        const __be32 laddr, const __u16 lport,
                                        const __be32 faddr, const __be16 fport)
{
        return jhash_3words((__force __u32) laddr,
                            (__force __u32) faddr,
                            ((__u32) lport) << 16 | (__force __u32)fport,
                            inet_ehash_secret + net_hash_mix(net));
}

static inline int inet_sk_ehashfn(const struct sock *sk)
{
        const struct inet_sock *inet = inet_sk(sk);
        const __be32 laddr = inet->inet_rcv_saddr;
        const __u16 lport = inet->inet_num;
        const __be32 faddr = inet->inet_daddr;
        const __be16 fport = inet->inet_dport;
        struct net *net = sock_net(sk);

        return inet_ehashfn(net, laddr, lport, faddr, fport);
}

static inline struct request_sock *inet_reqsk_alloc(struct request_sock_ops *ops)
{
        struct request_sock *req = reqsk_alloc(ops);
        struct inet_request_sock *ireq = inet_rsk(req);

        if (req != NULL) {
                kmemcheck_annotate_bitfield(ireq, flags);
                ireq->opt = NULL;
        }

        return req;
}

static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
{
        __u8 flags = 0;

        if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
                flags |= FLOWI_FLAG_ANYSRC;
        return flags;
}

#endif  /* _INET_SOCK_H */