inet_sock.h

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/*
 * 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 <[email protected]>
 *
 *      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 {
    __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;
    int         length; /* Total length of all frames */
    struct dst_entry    *dst;
    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 {
    /* 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 */