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