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 26#define UDP_HTABLE_SIZE_MIN_PERNET 128 27#define UDP_HTABLE_SIZE_MIN (CONFIG_BASE_SMALL ? 128 : 256) 28#define UDP_HTABLE_SIZE_MAX 65536 29 30static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask) 31{ 32 return (num + net_hash_mix(net)) & mask; 33} 34 35enum { 36 UDP_FLAGS_CORK, /* Cork is required */ 37 UDP_FLAGS_NO_CHECK6_TX, /* Send zero UDP6 checksums on TX? */ 38 UDP_FLAGS_NO_CHECK6_RX, /* Allow zero UDP6 checksums on RX? */ 39 UDP_FLAGS_GRO_ENABLED, /* Request GRO aggregation */ 40 UDP_FLAGS_ACCEPT_FRAGLIST, 41 UDP_FLAGS_ACCEPT_L4, 42 UDP_FLAGS_ENCAP_ENABLED, /* This socket enabled encap */ 43 UDP_FLAGS_UDPLITE_SEND_CC, /* set via udplite setsockopt */ 44 UDP_FLAGS_UDPLITE_RECV_CC, /* set via udplite setsockopt */ 45}; 46 47struct udp_sock { 48 /* inet_sock has to be the first member */ 49 struct inet_sock inet; 50#define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0] 51#define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1] 52#define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node 53 54 unsigned long udp_flags; 55 56 int pending; /* Any pending frames ? */ 57 __u8 encap_type; /* Is this an Encapsulation socket? */ 58 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 /* 71 * For encapsulation sockets. 72 */ 73 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 74 void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, int err, 75 __be16 port, u32 info, u8 *payload); 76 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb); 77 void (*encap_destroy)(struct sock *sk); 78 79 /* GRO functions for UDP socket */ 80 struct sk_buff * (*gro_receive)(struct sock *sk, 81 struct list_head *head, 82 struct sk_buff *skb); 83 int (*gro_complete)(struct sock *sk, 84 struct sk_buff *skb, 85 int nhoff); 86 87 /* udp_recvmsg try to use this before splicing sk_receive_queue */ 88 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp; 89 90 /* This field is dirtied by udp_recvmsg() */ 91 int forward_deficit; 92 93 /* This fields follows rcvbuf value, and is touched by udp_recvmsg */ 94 int forward_threshold; 95 96 /* Cache friendly copy of sk->sk_peek_off >= 0 */ 97 bool peeking_with_offset; 98}; 99 100#define udp_test_bit(nr, sk) \ 101 test_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 102#define udp_set_bit(nr, sk) \ 103 set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 104#define udp_test_and_set_bit(nr, sk) \ 105 test_and_set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 106#define udp_clear_bit(nr, sk) \ 107 clear_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 108#define udp_assign_bit(nr, sk, val) \ 109 assign_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags, val) 110 111#define UDP_MAX_SEGMENTS (1 << 6UL) 112 113#define udp_sk(ptr) container_of_const(ptr, struct udp_sock, inet.sk) 114 115static inline int udp_set_peek_off(struct sock *sk, int val) 116{ 117 sk_set_peek_off(sk, val); 118 WRITE_ONCE(udp_sk(sk)->peeking_with_offset, val >= 0); 119 return 0; 120} 121 122static inline void udp_set_no_check6_tx(struct sock *sk, bool val) 123{ 124 udp_assign_bit(NO_CHECK6_TX, sk, val); 125} 126 127static inline void udp_set_no_check6_rx(struct sock *sk, bool val) 128{ 129 udp_assign_bit(NO_CHECK6_RX, sk, val); 130} 131 132static inline bool udp_get_no_check6_tx(const struct sock *sk) 133{ 134 return udp_test_bit(NO_CHECK6_TX, sk); 135} 136 137static inline bool udp_get_no_check6_rx(const struct sock *sk) 138{ 139 return udp_test_bit(NO_CHECK6_RX, sk); 140} 141 142static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, 143 struct sk_buff *skb) 144{ 145 int gso_size; 146 147 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { 148 gso_size = skb_shinfo(skb)->gso_size; 149 put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size); 150 } 151} 152 153static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) 154{ 155 if (!skb_is_gso(skb)) 156 return false; 157 158 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && 159 !udp_test_bit(ACCEPT_L4, sk)) 160 return true; 161 162 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && 163 !udp_test_bit(ACCEPT_FRAGLIST, sk)) 164 return true; 165 166 return false; 167} 168 169static inline void udp_allow_gso(struct sock *sk) 170{ 171 udp_set_bit(ACCEPT_L4, sk); 172 udp_set_bit(ACCEPT_FRAGLIST, sk); 173} 174 175#define udp_portaddr_for_each_entry(__sk, list) \ 176 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node) 177 178#define udp_portaddr_for_each_entry_rcu(__sk, list) \ 179 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node) 180 181#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE) 182 183#endif /* _LINUX_UDP_H */ 184