summaryrefslogtreecommitdiff
path: root/include/linux/udp.h
blob: 3eb3f2b9a2a052452fe5f3e0208cf80e89a8ea39 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Definitions for the UDP protocol.
 *
 * Version:	@(#)udp.h	1.0.2	04/28/93
 *
 * Author:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 */
#ifndef _LINUX_UDP_H
#define _LINUX_UDP_H

#include <net/inet_sock.h>
#include <linux/skbuff.h>
#include <net/netns/hash.h>
#include <uapi/linux/udp.h>

static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
{
	return (struct udphdr *)skb_transport_header(skb);
}

#define UDP_HTABLE_SIZE_MIN_PERNET	128
#define UDP_HTABLE_SIZE_MIN		(IS_ENABLED(CONFIG_BASE_SMALL) ? 128 : 256)
#define UDP_HTABLE_SIZE_MAX		65536

static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
{
	return (num + net_hash_mix(net)) & mask;
}

enum {
	UDP_FLAGS_CORK,		/* Cork is required */
	UDP_FLAGS_NO_CHECK6_TX, /* Send zero UDP6 checksums on TX? */
	UDP_FLAGS_NO_CHECK6_RX, /* Allow zero UDP6 checksums on RX? */
	UDP_FLAGS_GRO_ENABLED,	/* Request GRO aggregation */
	UDP_FLAGS_ACCEPT_FRAGLIST,
	UDP_FLAGS_ACCEPT_L4,
	UDP_FLAGS_ENCAP_ENABLED, /* This socket enabled encap */
	UDP_FLAGS_UDPLITE_SEND_CC, /* set via udplite setsockopt */
	UDP_FLAGS_UDPLITE_RECV_CC, /* set via udplite setsockopt */
};

struct udp_sock {
	/* inet_sock has to be the first member */
	struct inet_sock inet;
#define udp_port_hash		inet.sk.__sk_common.skc_u16hashes[0]
#define udp_portaddr_hash	inet.sk.__sk_common.skc_u16hashes[1]
#define udp_portaddr_node	inet.sk.__sk_common.skc_portaddr_node

	unsigned long	 udp_flags;

	int		 pending;	/* Any pending frames ? */
	__u8		 encap_type;	/* Is this an Encapsulation socket? */

	/*
	 * Following member retains the information to create a UDP header
	 * when the socket is uncorked.
	 */
	__u16		 len;		/* total length of pending frames */
	__u16		 gso_size;
	/*
	 * Fields specific to UDP-Lite.
	 */
	__u16		 pcslen;
	__u16		 pcrlen;
	/*
	 * For encapsulation sockets.
	 */
	int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
	void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, int err,
			      __be16 port, u32 info, u8 *payload);
	int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb);
	void (*encap_destroy)(struct sock *sk);

	/* GRO functions for UDP socket */
	struct sk_buff *	(*gro_receive)(struct sock *sk,
					       struct list_head *head,
					       struct sk_buff *skb);
	int			(*gro_complete)(struct sock *sk,
						struct sk_buff *skb,
						int nhoff);

	/* udp_recvmsg try to use this before splicing sk_receive_queue */
	struct sk_buff_head	reader_queue ____cacheline_aligned_in_smp;

	/* This field is dirtied by udp_recvmsg() */
	int		forward_deficit;

	/* This fields follows rcvbuf value, and is touched by udp_recvmsg */
	int		forward_threshold;

	/* Cache friendly copy of sk->sk_peek_off >= 0 */
	bool		peeking_with_offset;
};

#define udp_test_bit(nr, sk)			\
	test_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags)
#define udp_set_bit(nr, sk)			\
	set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags)
#define udp_test_and_set_bit(nr, sk)		\
	test_and_set_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags)
#define udp_clear_bit(nr, sk)			\
	clear_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags)
#define udp_assign_bit(nr, sk, val)		\
	assign_bit(UDP_FLAGS_##nr, &udp_sk(sk)->udp_flags, val)

#define UDP_MAX_SEGMENTS	(1 << 7UL)

#define udp_sk(ptr) container_of_const(ptr, struct udp_sock, inet.sk)

static inline int udp_set_peek_off(struct sock *sk, int val)
{
	sk_set_peek_off(sk, val);
	WRITE_ONCE(udp_sk(sk)->peeking_with_offset, val >= 0);
	return 0;
}

static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
{
	udp_assign_bit(NO_CHECK6_TX, sk, val);
}

static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
{
	udp_assign_bit(NO_CHECK6_RX, sk, val);
}

static inline bool udp_get_no_check6_tx(const struct sock *sk)
{
	return udp_test_bit(NO_CHECK6_TX, sk);
}

static inline bool udp_get_no_check6_rx(const struct sock *sk)
{
	return udp_test_bit(NO_CHECK6_RX, sk);
}

static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk,
				 struct sk_buff *skb)
{
	int gso_size;

	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
		gso_size = skb_shinfo(skb)->gso_size;
		put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size);
	}
}

DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key);
#if IS_ENABLED(CONFIG_IPV6)
DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
#endif

static inline bool udp_encap_needed(void)
{
	if (static_branch_unlikely(&udp_encap_needed_key))
		return true;

#if IS_ENABLED(CONFIG_IPV6)
	if (static_branch_unlikely(&udpv6_encap_needed_key))
		return true;
#endif

	return false;
}

static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb)
{
	if (!skb_is_gso(skb))
		return false;

	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 &&
	    !udp_test_bit(ACCEPT_L4, sk))
		return true;

	if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST &&
	    !udp_test_bit(ACCEPT_FRAGLIST, sk))
		return true;

	/* GSO packets lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits might still
	 * land in a tunnel as the socket check in udp_gro_receive cannot be
	 * foolproof.
	 */
	if (udp_encap_needed() &&
	    READ_ONCE(udp_sk(sk)->encap_rcv) &&
	    !(skb_shinfo(skb)->gso_type &
	      (SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM)))
		return true;

	return false;
}

static inline void udp_allow_gso(struct sock *sk)
{
	udp_set_bit(ACCEPT_L4, sk);
	udp_set_bit(ACCEPT_FRAGLIST, sk);
}

#define udp_portaddr_for_each_entry(__sk, list) \
	hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)

#define udp_portaddr_for_each_entry_rcu(__sk, list) \
	hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)

#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)

#endif	/* _LINUX_UDP_H */