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
inner_udp_hdr(const struct sk_buff * skb)26 static inline struct udphdr *inner_udp_hdr(const struct sk_buff *skb)
27 {
28 return (struct udphdr *)skb_inner_transport_header(skb);
29 }
30
31 #define UDP_HTABLE_SIZE_MIN (CONFIG_BASE_SMALL ? 128 : 256)
32
udp_hashfn(const struct net * net,u32 num,u32 mask)33 static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
34 {
35 return (num + net_hash_mix(net)) & mask;
36 }
37
38 struct udp_sock {
39 /* inet_sock has to be the first member */
40 struct inet_sock inet;
41 #define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0]
42 #define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1]
43 #define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node
44 int pending; /* Any pending frames ? */
45 unsigned int corkflag; /* Cork is required */
46 __u8 encap_type; /* Is this an Encapsulation socket? */
47 unsigned char no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
48 no_check6_rx:1,/* Allow zero UDP6 checksums on RX? */
49 encap_enabled:1, /* This socket enabled encap
50 * processing; UDP tunnels and
51 * different encapsulation layer set
52 * this
53 */
54 gro_enabled:1, /* Request GRO aggregation */
55 accept_udp_l4:1,
56 accept_udp_fraglist:1;
57 /*
58 * Following member retains the information to create a UDP header
59 * when the socket is uncorked.
60 */
61 __u16 len; /* total length of pending frames */
62 __u16 gso_size;
63 /*
64 * Fields specific to UDP-Lite.
65 */
66 __u16 pcslen;
67 __u16 pcrlen;
68 /* indicator bits used by pcflag: */
69 #define UDPLITE_BIT 0x1 /* set by udplite proto init function */
70 #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */
71 #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */
72 __u8 pcflag; /* marks socket as UDP-Lite if > 0 */
73 __u8 unused[3];
74 /*
75 * For encapsulation sockets.
76 */
77 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
78 void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, unsigned int udp_offset);
79 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb);
80 void (*encap_destroy)(struct sock *sk);
81
82 /* GRO functions for UDP socket */
83 struct sk_buff * (*gro_receive)(struct sock *sk,
84 struct list_head *head,
85 struct sk_buff *skb);
86 int (*gro_complete)(struct sock *sk,
87 struct sk_buff *skb,
88 int nhoff);
89
90 /* udp_recvmsg try to use this before splicing sk_receive_queue */
91 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp;
92
93 /* This field is dirtied by udp_recvmsg() */
94 int forward_deficit;
95 };
96
97 #define UDP_MAX_SEGMENTS (1 << 6UL)
98
udp_sk(const struct sock * sk)99 static inline struct udp_sock *udp_sk(const struct sock *sk)
100 {
101 return (struct udp_sock *)sk;
102 }
103
udp_set_no_check6_tx(struct sock * sk,bool val)104 static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
105 {
106 udp_sk(sk)->no_check6_tx = val;
107 }
108
udp_set_no_check6_rx(struct sock * sk,bool val)109 static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
110 {
111 udp_sk(sk)->no_check6_rx = val;
112 }
113
udp_get_no_check6_tx(struct sock * sk)114 static inline bool udp_get_no_check6_tx(struct sock *sk)
115 {
116 return udp_sk(sk)->no_check6_tx;
117 }
118
udp_get_no_check6_rx(struct sock * sk)119 static inline bool udp_get_no_check6_rx(struct sock *sk)
120 {
121 return udp_sk(sk)->no_check6_rx;
122 }
123
udp_cmsg_recv(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)124 static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk,
125 struct sk_buff *skb)
126 {
127 int gso_size;
128
129 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
130 gso_size = skb_shinfo(skb)->gso_size;
131 put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size);
132 }
133 }
134
udp_unexpected_gso(struct sock * sk,struct sk_buff * skb)135 static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb)
136 {
137 if (!skb_is_gso(skb))
138 return false;
139
140 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4)
141 return true;
142
143 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist)
144 return true;
145
146 return false;
147 }
148
udp_allow_gso(struct sock * sk)149 static inline void udp_allow_gso(struct sock *sk)
150 {
151 udp_sk(sk)->accept_udp_l4 = 1;
152 udp_sk(sk)->accept_udp_fraglist = 1;
153 }
154
155 #define udp_portaddr_for_each_entry(__sk, list) \
156 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
157
158 #define udp_portaddr_for_each_entry_rcu(__sk, list) \
159 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
160
161 #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
162
163 #endif /* _LINUX_UDP_H */
164