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, <[email protected]> 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 u32 udp_hashfn(const struct net *net, u32 num, u32 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 __u8 encap_type; /* Is this an Encapsulation socket? */ 51 unsigned char no_check6_tx:1,/* Send zero UDP6 checksums on TX? */ 52 no_check6_rx:1,/* Allow zero UDP6 checksums on RX? */ 53 encap_enabled:1, /* This socket enabled encap 54 * processing; UDP tunnels and 55 * different encapsulation layer set 56 * this 57 */ 58 gro_enabled:1; /* Can accept GRO packets */ 59 /* 60 * Following member retains the information to create a UDP header 61 * when the socket is uncorked. 62 */ 63 __u16 len; /* total length of pending frames */ 64 __u16 gso_size; 65 /* 66 * Fields specific to UDP-Lite. 67 */ 68 __u16 pcslen; 69 __u16 pcrlen; 70 /* indicator bits used by pcflag: */ 71 #define UDPLITE_BIT 0x1 /* set by udplite proto init function */ 72 #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ 73 #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ 74 __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ 75 __u8 unused[3]; 76 /* 77 * For encapsulation sockets. 78 */ 79 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 80 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb); 81 void (*encap_destroy)(struct sock *sk); 82 83 /* GRO functions for UDP socket */ 84 struct sk_buff * (*gro_receive)(struct sock *sk, 85 struct list_head *head, 86 struct sk_buff *skb); 87 int (*gro_complete)(struct sock *sk, 88 struct sk_buff *skb, 89 int nhoff); 90 91 /* udp_recvmsg try to use this before splicing sk_receive_queue */ 92 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp; 93 94 /* This field is dirtied by udp_recvmsg() */ 95 int forward_deficit; 96 }; 97 98 #define UDP_MAX_SEGMENTS (1 << 6UL) 99 100 static inline struct udp_sock *udp_sk(const struct sock *sk) 101 { 102 return (struct udp_sock *)sk; 103 } 104 105 static inline void udp_set_no_check6_tx(struct sock *sk, bool val) 106 { 107 udp_sk(sk)->no_check6_tx = val; 108 } 109 110 static inline void udp_set_no_check6_rx(struct sock *sk, bool val) 111 { 112 udp_sk(sk)->no_check6_rx = val; 113 } 114 115 static inline bool udp_get_no_check6_tx(struct sock *sk) 116 { 117 return udp_sk(sk)->no_check6_tx; 118 } 119 120 static inline bool udp_get_no_check6_rx(struct sock *sk) 121 { 122 return udp_sk(sk)->no_check6_rx; 123 } 124 125 static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, 126 struct sk_buff *skb) 127 { 128 int gso_size; 129 130 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { 131 gso_size = skb_shinfo(skb)->gso_size; 132 put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size); 133 } 134 } 135 136 static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) 137 { 138 return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) && 139 skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4; 140 } 141 142 #define udp_portaddr_for_each_entry(__sk, list) \ 143 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node) 144 145 #define udp_portaddr_for_each_entry_rcu(__sk, list) \ 146 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node) 147 148 #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE) 149 150 #endif /* _LINUX_UDP_H */ 151