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 (IS_ENABLED(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 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 /* per NUMA structure for lockless producer usage. */ 48 struct udp_prod_queue { 49 struct llist_head ll_root ____cacheline_aligned_in_smp; 50 atomic_t rmem_alloc; 51 }; 52 53 struct udp_sock { 54 /* inet_sock has to be the first member */ 55 struct inet_sock inet; 56 #define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0] 57 #define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1] 58 #define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node 59 60 unsigned long udp_flags; 61 62 int pending; /* Any pending frames ? */ 63 __u8 encap_type; /* Is this an Encapsulation socket? */ 64 65 #if !IS_ENABLED(CONFIG_BASE_SMALL) 66 /* For UDP 4-tuple hash */ 67 __u16 udp_lrpa_hash; 68 struct hlist_nulls_node udp_lrpa_node; 69 #endif 70 71 /* 72 * Following member retains the information to create a UDP header 73 * when the socket is uncorked. 74 */ 75 __u16 len; /* total length of pending frames */ 76 __u16 gso_size; 77 /* 78 * Fields specific to UDP-Lite. 79 */ 80 __u16 pcslen; 81 __u16 pcrlen; 82 /* 83 * For encapsulation sockets. 84 */ 85 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 86 void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, int err, 87 __be16 port, u32 info, u8 *payload); 88 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb); 89 void (*encap_destroy)(struct sock *sk); 90 91 /* GRO functions for UDP socket */ 92 struct sk_buff * (*gro_receive)(struct sock *sk, 93 struct list_head *head, 94 struct sk_buff *skb); 95 int (*gro_complete)(struct sock *sk, 96 struct sk_buff *skb, 97 int nhoff); 98 99 struct udp_prod_queue *udp_prod_queue; 100 101 /* udp_recvmsg try to use this before splicing sk_receive_queue */ 102 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp; 103 104 /* This field is dirtied by udp_recvmsg() */ 105 int forward_deficit; 106 107 /* This fields follows rcvbuf value, and is touched by udp_recvmsg */ 108 int forward_threshold; 109 110 /* Cache friendly copy of sk->sk_peek_off >= 0 */ 111 bool peeking_with_offset; 112 113 /* 114 * Accounting for the tunnel GRO fastpath. 115 * Unprotected by compilers guard, as it uses space available in 116 * the last UDP socket cacheline. 117 */ 118 struct hlist_node tunnel_list; 119 struct numa_drop_counters drop_counters; 120 }; 121 122 #define udp_test_bit(nr, sk) \ 123 test_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 124 #define udp_set_bit(nr, sk) \ 125 set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 126 #define udp_test_and_set_bit(nr, sk) \ 127 test_and_set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 128 #define udp_clear_bit(nr, sk) \ 129 clear_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) 130 #define udp_assign_bit(nr, sk, val) \ 131 assign_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags, val) 132 133 #define UDP_MAX_SEGMENTS (1 << 7UL) 134 135 #define udp_sk(ptr) container_of_const(ptr, struct udp_sock, inet.sk) 136 137 static inline int udp_set_peek_off(struct sock *sk, int val) 138 { 139 sk_set_peek_off(sk, val); 140 WRITE_ONCE(udp_sk(sk)->peeking_with_offset, val >= 0); 141 return 0; 142 } 143 144 static inline void udp_set_no_check6_tx(struct sock *sk, bool val) 145 { 146 udp_assign_bit(NO_CHECK6_TX, sk, val); 147 } 148 149 static inline void udp_set_no_check6_rx(struct sock *sk, bool val) 150 { 151 udp_assign_bit(NO_CHECK6_RX, sk, val); 152 } 153 154 static inline bool udp_get_no_check6_tx(const struct sock *sk) 155 { 156 return udp_test_bit(NO_CHECK6_TX, sk); 157 } 158 159 static inline bool udp_get_no_check6_rx(const struct sock *sk) 160 { 161 return udp_test_bit(NO_CHECK6_RX, sk); 162 } 163 164 static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, 165 struct sk_buff *skb) 166 { 167 int gso_size; 168 169 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { 170 gso_size = skb_shinfo(skb)->gso_size; 171 put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size); 172 } 173 } 174 175 DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key); 176 #if IS_ENABLED(CONFIG_IPV6) 177 DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key); 178 #endif 179 180 static inline bool udp_encap_needed(void) 181 { 182 if (static_branch_unlikely(&udp_encap_needed_key)) 183 return true; 184 185 #if IS_ENABLED(CONFIG_IPV6) 186 if (static_branch_unlikely(&udpv6_encap_needed_key)) 187 return true; 188 #endif 189 190 return false; 191 } 192 193 static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) 194 { 195 if (!skb_is_gso(skb)) 196 return false; 197 198 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && 199 !udp_test_bit(ACCEPT_L4, sk)) 200 return true; 201 202 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && 203 !udp_test_bit(ACCEPT_FRAGLIST, sk)) 204 return true; 205 206 /* GSO packets lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits might still 207 * land in a tunnel as the socket check in udp_gro_receive cannot be 208 * foolproof. 209 */ 210 if (udp_encap_needed() && 211 READ_ONCE(udp_sk(sk)->encap_rcv) && 212 !(skb_shinfo(skb)->gso_type & 213 (SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM))) 214 return true; 215 216 return false; 217 } 218 219 static inline void udp_allow_gso(struct sock *sk) 220 { 221 udp_set_bit(ACCEPT_L4, sk); 222 udp_set_bit(ACCEPT_FRAGLIST, sk); 223 } 224 225 #define udp_portaddr_for_each_entry(__sk, list) \ 226 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node) 227 228 #define udp_portaddr_for_each_entry_from(__sk) \ 229 hlist_for_each_entry_from(__sk, __sk_common.skc_portaddr_node) 230 231 #define udp_portaddr_for_each_entry_rcu(__sk, list) \ 232 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node) 233 234 #if !IS_ENABLED(CONFIG_BASE_SMALL) 235 #define udp_lrpa_for_each_entry_rcu(__up, node, list) \ 236 hlist_nulls_for_each_entry_rcu(__up, node, list, udp_lrpa_node) 237 #endif 238 239 #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE) 240 241 static inline struct sock *udp_tunnel_sk(const struct net *net, bool is_ipv6) 242 { 243 #if IS_ENABLED(CONFIG_NET_UDP_TUNNEL) 244 return rcu_dereference(net->ipv4.udp_tunnel_gro[is_ipv6].sk); 245 #else 246 return NULL; 247 #endif 248 } 249 250 #endif /* _LINUX_UDP_H */ 251