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_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 enum { 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 }; 40 41 struct udp_sock { 42 /* inet_sock has to be the first member */ 43 struct inet_sock inet; 44 #define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0] 45 #define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1] 46 #define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node 47 48 unsigned long udp_flags; 49 50 int pending; /* Any pending frames ? */ 51 __u8 encap_type; /* Is this an Encapsulation socket? */ 52 unsigned char encap_enabled:1, /* This socket enabled encap 53 * processing; UDP tunnels and 54 * different encapsulation layer set 55 * this 56 */ 57 gro_enabled:1, /* Request GRO aggregation */ 58 accept_udp_l4:1, 59 accept_udp_fraglist:1; 60 /* indicator bits used by pcflag: */ 61 #define UDPLITE_BIT 0x1 /* set by udplite proto init function */ 62 #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ 63 #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ 64 __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ 65 /* 66 * Following member retains the information to create a UDP header 67 * when the socket is uncorked. 68 */ 69 __u16 len; /* total length of pending frames */ 70 __u16 gso_size; 71 /* 72 * Fields specific to UDP-Lite. 73 */ 74 __u16 pcslen; 75 __u16 pcrlen; 76 /* 77 * For encapsulation sockets. 78 */ 79 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 80 void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, int err, 81 __be16 port, u32 info, u8 *payload); 82 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb); 83 void (*encap_destroy)(struct sock *sk); 84 85 /* GRO functions for UDP socket */ 86 struct sk_buff * (*gro_receive)(struct sock *sk, 87 struct list_head *head, 88 struct sk_buff *skb); 89 int (*gro_complete)(struct sock *sk, 90 struct sk_buff *skb, 91 int nhoff); 92 93 /* udp_recvmsg try to use this before splicing sk_receive_queue */ 94 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp; 95 96 /* This field is dirtied by udp_recvmsg() */ 97 int forward_deficit; 98 99 /* This fields follows rcvbuf value, and is touched by udp_recvmsg */ 100 int forward_threshold; 101 }; 102 103 #define udp_test_bit(nr, sk) \ 104 test_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 105 #define udp_set_bit(nr, sk) \ 106 set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 107 #define udp_clear_bit(nr, sk) \ 108 clear_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 109 #define udp_assign_bit(nr, sk, val) \ 110 assign_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags, val) 111 112 #define UDP_MAX_SEGMENTS (1 << 6UL) 113 114 #define udp_sk(ptr) container_of_const(ptr, struct udp_sock, inet.sk) 115 116 static inline void udp_set_no_check6_tx(struct sock *sk, bool val) 117 { 118 udp_assign_bit(NO_CHECK6_TX, sk, val); 119 } 120 121 static inline void udp_set_no_check6_rx(struct sock *sk, bool val) 122 { 123 udp_assign_bit(NO_CHECK6_RX, sk, val); 124 } 125 126 static inline bool udp_get_no_check6_tx(const struct sock *sk) 127 { 128 return udp_test_bit(NO_CHECK6_TX, sk); 129 } 130 131 static inline bool udp_get_no_check6_rx(const struct sock *sk) 132 { 133 return udp_test_bit(NO_CHECK6_RX, sk); 134 } 135 136 static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, 137 struct sk_buff *skb) 138 { 139 int gso_size; 140 141 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { 142 gso_size = skb_shinfo(skb)->gso_size; 143 put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size); 144 } 145 } 146 147 static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) 148 { 149 if (!skb_is_gso(skb)) 150 return false; 151 152 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4) 153 return true; 154 155 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist) 156 return true; 157 158 return false; 159 } 160 161 static inline void udp_allow_gso(struct sock *sk) 162 { 163 udp_sk(sk)->accept_udp_l4 = 1; 164 udp_sk(sk)->accept_udp_fraglist = 1; 165 } 166 167 #define udp_portaddr_for_each_entry(__sk, list) \ 168 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node) 169 170 #define udp_portaddr_for_each_entry_rcu(__sk, list) \ 171 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node) 172 173 #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE) 174 175 #endif /* _LINUX_UDP_H */ 176