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 #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 30 static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask) 31 { 32 return (num + net_hash_mix(net)) & mask; 33 } 34 35 struct udp_sock { 36 /* inet_sock has to be the first member */ 37 struct inet_sock inet; 38 #define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0] 39 #define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1] 40 #define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node 41 int pending; /* Any pending frames ? */ 42 unsigned int corkflag; /* Cork is required */ 43 __u8 encap_type; /* Is this an Encapsulation socket? */ 44 unsigned char no_check6_tx:1,/* Send zero UDP6 checksums on TX? */ 45 no_check6_rx:1,/* Allow zero UDP6 checksums on RX? */ 46 encap_enabled:1, /* This socket enabled encap 47 * processing; UDP tunnels and 48 * different encapsulation layer set 49 * this 50 */ 51 gro_enabled:1, /* Request GRO aggregation */ 52 accept_udp_l4:1, 53 accept_udp_fraglist:1; 54 /* 55 * Following member retains the information to create a UDP header 56 * when the socket is uncorked. 57 */ 58 __u16 len; /* total length of pending frames */ 59 __u16 gso_size; 60 /* 61 * Fields specific to UDP-Lite. 62 */ 63 __u16 pcslen; 64 __u16 pcrlen; 65 /* indicator bits used by pcflag: */ 66 #define UDPLITE_BIT 0x1 /* set by udplite proto init function */ 67 #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ 68 #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ 69 __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ 70 __u8 unused[3]; 71 /* 72 * For encapsulation sockets. 73 */ 74 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 75 void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, int err, 76 __be16 port, u32 info, u8 *payload); 77 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb); 78 void (*encap_destroy)(struct sock *sk); 79 80 /* GRO functions for UDP socket */ 81 struct sk_buff * (*gro_receive)(struct sock *sk, 82 struct list_head *head, 83 struct sk_buff *skb); 84 int (*gro_complete)(struct sock *sk, 85 struct sk_buff *skb, 86 int nhoff); 87 88 /* udp_recvmsg try to use this before splicing sk_receive_queue */ 89 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp; 90 91 /* This field is dirtied by udp_recvmsg() */ 92 int forward_deficit; 93 94 /* This fields follows rcvbuf value, and is touched by udp_recvmsg */ 95 int forward_threshold; 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 if (!skb_is_gso(skb)) 139 return false; 140 141 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4) 142 return true; 143 144 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist) 145 return true; 146 147 return false; 148 } 149 150 static inline void udp_allow_gso(struct sock *sk) 151 { 152 udp_sk(sk)->accept_udp_l4 = 1; 153 udp_sk(sk)->accept_udp_fraglist = 1; 154 } 155 156 #define udp_portaddr_for_each_entry(__sk, list) \ 157 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node) 158 159 #define udp_portaddr_for_each_entry_rcu(__sk, list) \ 160 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node) 161 162 #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE) 163 164 #endif /* _LINUX_UDP_H */ 165