LXR linux/include/linux/udp.h

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4 *              operating system.  INET is implemented using the  BSD Socket
   5 *              interface as the means of communication with the user level.
   6 *
   7 *              Definitions for the UDP protocol.
   8 *
   9 * Version:     @(#)udp.h       1.0.2   04/28/93
  10 *
  11 * Author:      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12 */
  13#ifndef _LINUX_UDP_H
  14#define _LINUX_UDP_H
  15
  16#include <net/inet_sock.h>
  17#include <linux/skbuff.h>
  18#include <net/netns/hash.h>
  19#include <uapi/linux/udp.h>
  20
  21static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
  22{
  23        return (struct udphdr *)skb_transport_header(skb);
  24}
  25
  26static inline struct udphdr *inner_udp_hdr(const struct sk_buff *skb)
  27{
  28        return (struct udphdr *)skb_inner_transport_header(skb);
  29}
  30
  31#define UDP_HTABLE_SIZE_MIN             (CONFIG_BASE_SMALL ? 128 : 256)
  32
  33static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
  34{
  35        return (num + net_hash_mix(net)) & mask;
  36}
  37
  38struct udp_sock {
  39        /* inet_sock has to be the first member */
  40        struct inet_sock inet;
  41#define udp_port_hash           inet.sk.__sk_common.skc_u16hashes[0]
  42#define udp_portaddr_hash       inet.sk.__sk_common.skc_u16hashes[1]
  43#define udp_portaddr_node       inet.sk.__sk_common.skc_portaddr_node
  44        int              pending;       /* Any pending frames ? */
  45        unsigned int     corkflag;      /* Cork is required */
  46        __u8             encap_type;    /* Is this an Encapsulation socket? */
  47        unsigned char    no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
  48                         no_check6_rx:1,/* Allow zero UDP6 checksums on RX? */
  49                         encap_enabled:1, /* This socket enabled encap
  50                                           * processing; UDP tunnels and
  51                                           * different encapsulation layer set
  52                                           * this
  53                                           */
  54                         gro_enabled:1, /* Request GRO aggregation */
  55                         accept_udp_l4:1,
  56                         accept_udp_fraglist:1;
  57        /*
  58         * Following member retains the information to create a UDP header
  59         * when the socket is uncorked.
  60         */
  61        __u16            len;           /* total length of pending frames */
  62        __u16            gso_size;
  63        /*
  64         * Fields specific to UDP-Lite.
  65         */
  66        __u16            pcslen;
  67        __u16            pcrlen;
  68/* indicator bits used by pcflag: */
  69#define UDPLITE_BIT      0x1            /* set by udplite proto init function */
  70#define UDPLITE_SEND_CC  0x2            /* set via udplite setsockopt         */
  71#define UDPLITE_RECV_CC  0x4            /* set via udplite setsocktopt        */
  72        __u8             pcflag;        /* marks socket as UDP-Lite if > 0    */
  73        __u8             unused[3];
  74        /*
  75         * For encapsulation sockets.
  76         */
  77        int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
  78        int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb);
  79        void (*encap_destroy)(struct sock *sk);
  80
  81        /* GRO functions for UDP socket */
  82        struct sk_buff *        (*gro_receive)(struct sock *sk,
  83                                               struct list_head *head,
  84                                               struct sk_buff *skb);
  85        int                     (*gro_complete)(struct sock *sk,
  86                                                struct sk_buff *skb,
  87                                                int nhoff);
  88
  89        /* udp_recvmsg try to use this before splicing sk_receive_queue */
  90        struct sk_buff_head     reader_queue ____cacheline_aligned_in_smp;
  91
  92        /* This field is dirtied by udp_recvmsg() */
  93        int             forward_deficit;
  94};
  95
  96#define UDP_MAX_SEGMENTS        (1 << 6UL)
  97
  98static inline struct udp_sock *udp_sk(const struct sock *sk)
  99{
 100        return (struct udp_sock *)sk;
 101}
 102
 103static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
 104{
 105        udp_sk(sk)->no_check6_tx = val;
 106}
 107
 108static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
 109{
 110        udp_sk(sk)->no_check6_rx = val;
 111}
 112
 113static inline bool udp_get_no_check6_tx(struct sock *sk)
 114{
 115        return udp_sk(sk)->no_check6_tx;
 116}
 117
 118static inline bool udp_get_no_check6_rx(struct sock *sk)
 119{
 120        return udp_sk(sk)->no_check6_rx;
 121}
 122
 123static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk,
 124                                 struct sk_buff *skb)
 125{
 126        int gso_size;
 127
 128        if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
 129                gso_size = skb_shinfo(skb)->gso_size;
 130                put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size);
 131        }
 132}
 133
 134static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb)
 135{
 136        if (!skb_is_gso(skb))
 137                return false;
 138
 139        if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4)
 140                return true;
 141
 142        if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist)
 143                return true;
 144
 145        return false;
 146}
 147
 148static inline void udp_allow_gso(struct sock *sk)
 149{
 150        udp_sk(sk)->accept_udp_l4 = 1;
 151        udp_sk(sk)->accept_udp_fraglist = 1;
 152}
 153
 154#define udp_portaddr_for_each_entry(__sk, list) \
 155        hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
 156
 157#define udp_portaddr_for_each_entry_rcu(__sk, list) \
 158        hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
 159
 160#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
 161
 162#endif  /* _LINUX_UDP_H */
 163