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 | 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 | /* Cache friendly copy of sk->sk_peek_off >= 0 */ |
97 | bool peeking_with_offset; |
98 | }; |
99 | |
100 | #define udp_test_bit(nr, sk) \ |
101 | test_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) |
102 | #define udp_set_bit(nr, sk) \ |
103 | set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) |
104 | #define udp_test_and_set_bit(nr, sk) \ |
105 | test_and_set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) |
106 | #define udp_clear_bit(nr, sk) \ |
107 | clear_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags) |
108 | #define udp_assign_bit(nr, sk, val) \ |
109 | assign_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags, val) |
110 | |
111 | #define UDP_MAX_SEGMENTS (1 << 7UL) |
112 | |
113 | #define udp_sk(ptr) container_of_const(ptr, struct udp_sock, inet.sk) |
114 | |
115 | static inline int udp_set_peek_off(struct sock *sk, int val) |
116 | { |
117 | sk_set_peek_off(sk, val); |
118 | WRITE_ONCE(udp_sk(sk)->peeking_with_offset, val >= 0); |
119 | return 0; |
120 | } |
121 | |
122 | static inline void udp_set_no_check6_tx(struct sock *sk, bool val) |
123 | { |
124 | udp_assign_bit(NO_CHECK6_TX, sk, val); |
125 | } |
126 | |
127 | static inline void udp_set_no_check6_rx(struct sock *sk, bool val) |
128 | { |
129 | udp_assign_bit(NO_CHECK6_RX, sk, val); |
130 | } |
131 | |
132 | static inline bool udp_get_no_check6_tx(const struct sock *sk) |
133 | { |
134 | return udp_test_bit(NO_CHECK6_TX, sk); |
135 | } |
136 | |
137 | static inline bool udp_get_no_check6_rx(const struct sock *sk) |
138 | { |
139 | return udp_test_bit(NO_CHECK6_RX, sk); |
140 | } |
141 | |
142 | static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, |
143 | struct sk_buff *skb) |
144 | { |
145 | int gso_size; |
146 | |
147 | if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { |
148 | gso_size = skb_shinfo(skb)->gso_size; |
149 | put_cmsg(msg, SOL_UDP, UDP_GRO, len: sizeof(gso_size), data: &gso_size); |
150 | } |
151 | } |
152 | |
153 | DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key); |
154 | #if IS_ENABLED(CONFIG_IPV6) |
155 | DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key); |
156 | #endif |
157 | |
158 | static inline bool udp_encap_needed(void) |
159 | { |
160 | if (static_branch_unlikely(&udp_encap_needed_key)) |
161 | return true; |
162 | |
163 | #if IS_ENABLED(CONFIG_IPV6) |
164 | if (static_branch_unlikely(&udpv6_encap_needed_key)) |
165 | return true; |
166 | #endif |
167 | |
168 | return false; |
169 | } |
170 | |
171 | static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) |
172 | { |
173 | if (!skb_is_gso(skb)) |
174 | return false; |
175 | |
176 | if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && |
177 | !udp_test_bit(ACCEPT_L4, sk)) |
178 | return true; |
179 | |
180 | if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && |
181 | !udp_test_bit(ACCEPT_FRAGLIST, sk)) |
182 | return true; |
183 | |
184 | /* GSO packets lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits might still |
185 | * land in a tunnel as the socket check in udp_gro_receive cannot be |
186 | * foolproof. |
187 | */ |
188 | if (udp_encap_needed() && |
189 | READ_ONCE(udp_sk(sk)->encap_rcv) && |
190 | !(skb_shinfo(skb)->gso_type & |
191 | (SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM))) |
192 | return true; |
193 | |
194 | return false; |
195 | } |
196 | |
197 | static inline void udp_allow_gso(struct sock *sk) |
198 | { |
199 | udp_set_bit(ACCEPT_L4, sk); |
200 | udp_set_bit(ACCEPT_FRAGLIST, sk); |
201 | } |
202 | |
203 | #define udp_portaddr_for_each_entry(__sk, list) \ |
204 | hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node) |
205 | |
206 | #define udp_portaddr_for_each_entry_rcu(__sk, list) \ |
207 | hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node) |
208 | |
209 | #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE) |
210 | |
211 | #endif /* _LINUX_UDP_H */ |
212 | |