zephyr/drivers/net/loopback.c

162 lines
3.8 KiB
C

/*
* Copyright (c) 2015 Intel Corporation
* Copyright (c) 2017 Linaro Limited
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
*
* Network loopback interface implementation.
*/
#define LOG_MODULE_NAME netlo
#define LOG_LEVEL CONFIG_NET_LOOPBACK_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(LOG_MODULE_NAME);
#include <zephyr/net/net_pkt.h>
#include <zephyr/net_buf.h>
#include <zephyr/net/net_ip.h>
#include <zephyr/net/net_if.h>
#include <zephyr/net/loopback.h>
#include <zephyr/net/dummy.h>
int loopback_dev_init(const struct device *dev)
{
ARG_UNUSED(dev);
return 0;
}
static void loopback_init(struct net_if *iface)
{
struct net_if_addr *ifaddr;
/* RFC 7042, s.2.1.1. address to use in documentation */
net_if_set_link_addr(iface, "\x00\x00\x5e\x00\x53\xff", 6,
NET_LINK_DUMMY);
if (IS_ENABLED(CONFIG_NET_IPV4)) {
struct in_addr ipv4_loopback = INADDR_LOOPBACK_INIT;
struct in_addr netmask = { { { 255, 0, 0, 0 } } };
ifaddr = net_if_ipv4_addr_add(iface, &ipv4_loopback,
NET_ADDR_AUTOCONF, 0);
if (!ifaddr) {
LOG_ERR("Failed to register IPv4 loopback address");
}
net_if_ipv4_set_netmask_by_addr(iface, &ipv4_loopback, &netmask);
}
if (IS_ENABLED(CONFIG_NET_IPV6)) {
struct in6_addr ipv6_loopback = IN6ADDR_LOOPBACK_INIT;
ifaddr = net_if_ipv6_addr_add(iface, &ipv6_loopback,
NET_ADDR_AUTOCONF, 0);
if (!ifaddr) {
LOG_ERR("Failed to register IPv6 loopback address");
}
}
}
#ifdef CONFIG_NET_LOOPBACK_SIMULATE_PACKET_DROP
static float loopback_packet_drop_ratio = 0.0f;
static float loopback_packet_drop_state = 0.0f;
static int loopback_packet_dropped_count;
int loopback_set_packet_drop_ratio(float ratio)
{
if (ratio < 0.0f || ratio > 1.0f) {
return -EINVAL;
}
loopback_packet_drop_ratio = ratio;
return 0;
}
int loopback_get_num_dropped_packets(void)
{
return loopback_packet_dropped_count;
}
#endif
static int loopback_send(const struct device *dev, struct net_pkt *pkt)
{
struct net_pkt *cloned;
int res;
ARG_UNUSED(dev);
#ifdef CONFIG_NET_LOOPBACK_SIMULATE_PACKET_DROP
/* Drop packets based on the loopback_packet_drop_ratio
* a ratio of 0.2 will drop one every 5 packets
*/
loopback_packet_drop_state += loopback_packet_drop_ratio;
if (loopback_packet_drop_state >= 1.0f) {
/* Administrate we dropped a packet */
loopback_packet_drop_state -= 1.0f;
loopback_packet_dropped_count++;
return 0;
}
#endif
if (!pkt->frags) {
LOG_ERR("No data to send");
return -ENODATA;
}
/* We should simulate normal driver meaning that if the packet is
* properly sent (which is always in this driver), then the packet
* must be dropped. This is very much needed for TCP packets where
* the packet is reference counted in various stages of sending.
*/
cloned = net_pkt_rx_clone(pkt, K_MSEC(100));
if (!cloned) {
res = -ENOMEM;
goto out;
}
/* We need to swap the IP addresses because otherwise
* the packet will be dropped.
*/
if (net_pkt_family(pkt) == AF_INET6) {
net_ipv6_addr_copy_raw(NET_IPV6_HDR(cloned)->src,
NET_IPV6_HDR(pkt)->dst);
net_ipv6_addr_copy_raw(NET_IPV6_HDR(cloned)->dst,
NET_IPV6_HDR(pkt)->src);
} else {
net_ipv4_addr_copy_raw(NET_IPV4_HDR(cloned)->src,
NET_IPV4_HDR(pkt)->dst);
net_ipv4_addr_copy_raw(NET_IPV4_HDR(cloned)->dst,
NET_IPV4_HDR(pkt)->src);
}
res = net_recv_data(net_pkt_iface(cloned), cloned);
if (res < 0) {
LOG_ERR("Data receive failed.");
}
out:
/* Let the receiving thread run now */
k_yield();
return res;
}
static struct dummy_api loopback_api = {
.iface_api.init = loopback_init,
.send = loopback_send,
};
NET_DEVICE_INIT(loopback, "lo",
loopback_dev_init, NULL, NULL, NULL,
CONFIG_KERNEL_INIT_PRIORITY_DEFAULT,
&loopback_api, DUMMY_L2,
NET_L2_GET_CTX_TYPE(DUMMY_L2), CONFIG_NET_LOOPBACK_MTU);