include/linux/udp.h

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              Definitions for the UDP protocol.
   7  *
   8  * Version:     @(#)udp.h       1.0.2   04/28/93
   9  *
  10  * Author:      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  11  *
  12  *              This program is free software; you can redistribute it and/or
  13  *              modify it under the terms of the GNU General Public License
  14  *              as published by the Free Software Foundation; either version
  15  *              2 of the License, or (at your option) any later version.
  16  */
  17 #ifndef _LINUX_UDP_H
  18 #define _LINUX_UDP_H
  19
  20 #include <net/inet_sock.h>
  21 #include <linux/skbuff.h>
  22 #include <net/netns/hash.h>
  23 #include <uapi/linux/udp.h>
  24
  25 static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
  26 {
  27         return (struct udphdr *)skb_transport_header(skb);
  28 }
  29
  30 static inline struct udphdr *inner_udp_hdr(const struct sk_buff *skb)
  31 {
  32         return (struct udphdr *)skb_inner_transport_header(skb);
  33 }
  34
  35 #define UDP_HTABLE_SIZE_MIN             (CONFIG_BASE_SMALL ? 128 : 256)
  36
  37 static inline int udp_hashfn(struct net *net, unsigned num, unsigned mask)
  38 {
  39         return (num + net_hash_mix(net)) & mask;
  40 }
  41
  42 struct udp_sock {
  43         /* inet_sock has to be the first member */
  44         struct inet_sock inet;
  45 #define udp_port_hash           inet.sk.__sk_common.skc_u16hashes[0]
  46 #define udp_portaddr_hash       inet.sk.__sk_common.skc_u16hashes[1]
  47 #define udp_portaddr_node       inet.sk.__sk_common.skc_portaddr_node
  48         int              pending;       /* Any pending frames ? */
  49         unsigned int     corkflag;      /* Cork is required */
  50         __u16            encap_type;    /* Is this an Encapsulation socket? */
  51         /*
  52          * Following member retains the information to create a UDP header
  53          * when the socket is uncorked.
  54          */
  55         __u16            len;           /* total length of pending frames */
  56         /*
  57          * Fields specific to UDP-Lite.
  58          */
  59         __u16            pcslen;
  60         __u16            pcrlen;
  61 /* indicator bits used by pcflag: */
  62 #define UDPLITE_BIT      0x1            /* set by udplite proto init function */
  63 #define UDPLITE_SEND_CC  0x2            /* set via udplite setsockopt         */
  64 #define UDPLITE_RECV_CC  0x4            /* set via udplite setsocktopt        */
  65         __u8             pcflag;        /* marks socket as UDP-Lite if > 0    */
  66         __u8             unused[3];
  67         /*
  68          * For encapsulation sockets.
  69          */
  70         int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
  71         void (*encap_destroy)(struct sock *sk);
  72 };
  73
  74 static inline struct udp_sock *udp_sk(const struct sock *sk)
  75 {
  76         return (struct udp_sock *)sk;
  77 }
  78
  79 #define udp_portaddr_for_each_entry(__sk, node, list) \
  80         hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node)
  81
  82 #define udp_portaddr_for_each_entry_rcu(__sk, node, list) \
  83         hlist_nulls_for_each_entry_rcu(__sk, node, list, __sk_common.skc_portaddr_node)
  84
  85 #define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)
  86
  87 #endif  /* _LINUX_UDP_H */