net/ipv4/udp_tunnel_core.c

Source file repositories/reference/linux-study-clean/net/ipv4/udp_tunnel_core.c

File Facts

System
Linux kernel
Corpus path
net/ipv4/udp_tunnel_core.c
Extension
.c
Size
6867 bytes
Lines
276
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <net/dst_metadata.h>
#include <net/flow.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/inet_dscp.h>

int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
		     struct socket **sockp)
{
	int err;
	struct socket *sock = NULL;
	struct sockaddr_in udp_addr;

	err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 0, &sock);
	if (err < 0)
		goto error;

	if (cfg->bind_ifindex) {
		err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true);
		if (err < 0)
			goto error;
	}

	udp_addr.sin_family = AF_INET;
	udp_addr.sin_addr = cfg->local_ip;
	udp_addr.sin_port = cfg->local_udp_port;
	err = kernel_bind(sock, (struct sockaddr_unsized *)&udp_addr,
			  sizeof(udp_addr));
	if (err < 0)
		goto error;

	if (cfg->peer_udp_port) {
		udp_addr.sin_family = AF_INET;
		udp_addr.sin_addr = cfg->peer_ip;
		udp_addr.sin_port = cfg->peer_udp_port;
		err = kernel_connect(sock, (struct sockaddr_unsized *)&udp_addr,
				     sizeof(udp_addr), 0);
		if (err < 0)
			goto error;
	}

	sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;

	*sockp = sock;
	return 0;

error:
	if (sock) {
		kernel_sock_shutdown(sock, SHUT_RDWR);
		sock_release(sock);
	}
	*sockp = NULL;
	return err;
}
EXPORT_SYMBOL(udp_sock_create4);

static bool sk_saddr_any(struct sock *sk)
{
#if IS_ENABLED(CONFIG_IPV6)
	return ipv6_addr_any(&sk->sk_v6_rcv_saddr);
#else
	return !sk->sk_rcv_saddr;
#endif
}

void setup_udp_tunnel_sock(struct net *net, struct sock *sk,
			   struct udp_tunnel_sock_cfg *cfg)
{
	/* Disable multicast loopback */
	inet_clear_bit(MC_LOOP, sk);

	/* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
	inet_inc_convert_csum(sk);

	rcu_assign_sk_user_data(sk, cfg->sk_user_data);

	udp_sk(sk)->encap_type = cfg->encap_type;
	udp_sk(sk)->encap_rcv = cfg->encap_rcv;
	udp_sk(sk)->encap_err_rcv = cfg->encap_err_rcv;
	udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup;
	udp_sk(sk)->encap_destroy = cfg->encap_destroy;
	udp_sk(sk)->gro_receive = cfg->gro_receive;
	udp_sk(sk)->gro_complete = cfg->gro_complete;

	udp_tunnel_encap_enable(sk);

Annotation

Implementation Notes