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 udp_hdr(const struct sk_buff * skb)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 udp_hashfn(const struct net * net,u32 num,u32 mask)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 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 47 struct 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 97 #define udp_test_bit(nr, sk) \ 98 test_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 99 #define udp_set_bit(nr, sk) \ 100 set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 101 #define udp_test_and_set_bit(nr, sk) \ 102 test_and_set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 103 #define udp_clear_bit(nr, sk) \ 104 clear_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 105 #define udp_assign_bit(nr, sk, val) \ 106 assign_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags, val) 107 108 #define UDP_MAX_SEGMENTS (1 << 7UL) 109 110 #define udp_sk(ptr) container_of_const(ptr, struct udp_sock, inet.sk) 111 udp_set_no_check6_tx(struct sock * sk,bool val)112 static inline void udp_set_no_check6_tx(struct sock *sk, bool val) 113 { 114 udp_assign_bit(NO_CHECK6_TX, sk, val); 115 } 116 udp_set_no_check6_rx(struct sock * sk,bool val)117 static inline void udp_set_no_check6_rx(struct sock *sk, bool val) 118 { 119 udp_assign_bit(NO_CHECK6_RX, sk, val); 120 } 121 udp_get_no_check6_tx(const struct sock * sk)122 static inline bool udp_get_no_check6_tx(const struct sock *sk) 123 { 124 return udp_test_bit(NO_CHECK6_TX, sk); 125 } 126 udp_get_no_check6_rx(const struct sock * sk)127 static inline bool udp_get_no_check6_rx(const struct sock *sk) 128 { 129 return udp_test_bit(NO_CHECK6_RX, sk); 130 } 131 udp_cmsg_recv(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)132 static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, 133 struct sk_buff *skb) 134 { 135 int gso_size; 136 137 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { 138 gso_size = skb_shinfo(skb)->gso_size; 139 put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size); 140 } 141 } 142 143 DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key); 144 #if IS_ENABLED(CONFIG_IPV6) 145 DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key); 146 #endif 147 udp_encap_needed(void)148 static inline bool udp_encap_needed(void) 149 { 150 if (static_branch_unlikely(&udp_encap_needed_key)) 151 return true; 152 153 #if IS_ENABLED(CONFIG_IPV6) 154 if (static_branch_unlikely(&udpv6_encap_needed_key)) 155 return true; 156 #endif 157 158 return false; 159 } 160 udp_unexpected_gso(struct sock * sk,struct sk_buff * skb)161 static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) 162 { 163 if (!skb_is_gso(skb)) 164 return false; 165 166 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && 167 !udp_test_bit(ACCEPT_L4, sk)) 168 return true; 169 170 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && 171 !udp_test_bit(ACCEPT_FRAGLIST, sk)) 172 return true; 173 174 /* GSO packets lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits might still 175 * land in a tunnel as the socket check in udp_gro_receive cannot be 176 * foolproof. 177 */ 178 if (udp_encap_needed() && 179 READ_ONCE(udp_sk(sk)->encap_rcv) && 180 !(skb_shinfo(skb)->gso_type & 181 (SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM))) 182 return true; 183 184 return false; 185 } 186 udp_allow_gso(struct sock * sk)187 static inline void udp_allow_gso(struct sock *sk) 188 { 189 udp_set_bit(ACCEPT_L4, sk); 190 udp_set_bit(ACCEPT_FRAGLIST, sk); 191 } 192 193 #define udp_portaddr_for_each_entry(__sk, list) \ 194 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node) 195 196 #define udp_portaddr_for_each_entry_rcu(__sk, list) \ 197 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node) 198 199 #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE) 200 201 #endif /* _LINUX_UDP_H */ 202