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 21 static inline struct udphdr *udp_hdr(const struct sk_buff *skb) 22 { 23 return (struct udphdr *)skb_transport_header(skb); 24 } 25 26 static 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 33 static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask) 34 { 35 return (num + net_hash_mix(net)) & mask; 36 } 37 38 struct 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 98 static inline struct udp_sock *udp_sk(const struct sock *sk) 99 { 100 return (struct udp_sock *)sk; 101 } 102 103 static inline void udp_set_no_check6_tx(struct sock *sk, bool val) 104 { 105 udp_sk(sk)->no_check6_tx = val; 106 } 107 108 static inline void udp_set_no_check6_rx(struct sock *sk, bool val) 109 { 110 udp_sk(sk)->no_check6_rx = val; 111 } 112 113 static inline bool udp_get_no_check6_tx(struct sock *sk) 114 { 115 return udp_sk(sk)->no_check6_tx; 116 } 117 118 static inline bool udp_get_no_check6_rx(struct sock *sk) 119 { 120 return udp_sk(sk)->no_check6_rx; 121 } 122 123 static 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 } 133 134 static 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 } 147 148 static 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