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/* 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, <[email protected]>
*/
#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 (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;
};
#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 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 */
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