zephyr/drivers/net/slip.c

433 lines
8.2 KiB
C

/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
*
* SLIP driver using uart_pipe. This is meant for network connectivity between
* host and qemu. The host will need to run tunslip process.
*/
#define LOG_MODULE_NAME slip
#define LOG_LEVEL CONFIG_SLIP_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(LOG_MODULE_NAME);
#include <stdio.h>
#include <zephyr/kernel.h>
#include <errno.h>
#include <stddef.h>
#include <zephyr/sys/util.h>
#include <zephyr/net/ethernet.h>
#include <zephyr/net/net_core.h>
#include <zephyr/net/dummy.h>
#include <zephyr/drivers/uart_pipe.h>
#include <zephyr/random/random.h>
#include "slip.h"
#define SLIP_END 0300
#define SLIP_ESC 0333
#define SLIP_ESC_END 0334
#define SLIP_ESC_ESC 0335
enum slip_state {
STATE_GARBAGE,
STATE_OK,
STATE_ESC,
};
#if defined(CONFIG_NET_BUF_FIXED_DATA_SIZE)
#define SLIP_FRAG_LEN CONFIG_NET_BUF_DATA_SIZE
#else
#define SLIP_FRAG_LEN _SLIP_MTU
#endif /* CONFIG_NET_BUF_FIXED_DATA_SIZE */
static inline void slip_writeb(unsigned char c)
{
uint8_t buf[1] = { c };
uart_pipe_send(&buf[0], 1);
}
/**
* @brief Write byte to SLIP, escape if it is END or ESC character
*
* @param c a byte to write
*/
static void slip_writeb_esc(unsigned char c)
{
switch (c) {
case SLIP_END:
/* If it's the same code as an END character,
* we send a special two character code so as
* not to make the receiver think we sent
* an END.
*/
slip_writeb(SLIP_ESC);
slip_writeb(SLIP_ESC_END);
break;
case SLIP_ESC:
/* If it's the same code as an ESC character,
* we send a special two character code so as
* not to make the receiver think we sent
* an ESC.
*/
slip_writeb(SLIP_ESC);
slip_writeb(SLIP_ESC_ESC);
break;
default:
slip_writeb(c);
}
}
int slip_send(const struct device *dev, struct net_pkt *pkt)
{
struct net_buf *buf;
uint8_t *ptr;
uint16_t i;
uint8_t c;
ARG_UNUSED(dev);
if (!pkt->buffer) {
/* No data? */
return -ENODATA;
}
slip_writeb(SLIP_END);
for (buf = pkt->buffer; buf; buf = buf->frags) {
ptr = buf->data;
for (i = 0U; i < buf->len; ++i) {
c = *ptr++;
slip_writeb_esc(c);
}
if (LOG_LEVEL >= LOG_LEVEL_DBG) {
LOG_DBG("sent data %d bytes", buf->len);
if (buf->len) {
LOG_HEXDUMP_DBG(buf->data,
buf->len, "<slip ");
}
}
}
slip_writeb(SLIP_END);
return 0;
}
static struct net_pkt *slip_poll_handler(struct slip_context *slip)
{
if (slip->last && slip->last->len) {
return slip->rx;
}
return NULL;
}
static inline struct net_if *get_iface(struct slip_context *context,
uint16_t vlan_tag)
{
#if defined(CONFIG_NET_VLAN)
struct net_if *iface;
iface = net_eth_get_vlan_iface(context->iface, vlan_tag);
if (!iface) {
return context->iface;
}
return iface;
#else
ARG_UNUSED(vlan_tag);
return context->iface;
#endif
}
static void process_msg(struct slip_context *slip)
{
uint16_t vlan_tag = NET_VLAN_TAG_UNSPEC;
struct net_pkt *pkt;
pkt = slip_poll_handler(slip);
if (!pkt || !pkt->buffer) {
return;
}
#if defined(CONFIG_NET_VLAN)
{
struct net_eth_hdr *hdr = NET_ETH_HDR(pkt);
if (ntohs(hdr->type) == NET_ETH_PTYPE_VLAN) {
struct net_eth_vlan_hdr *hdr_vlan =
(struct net_eth_vlan_hdr *)NET_ETH_HDR(pkt);
net_pkt_set_vlan_tci(pkt, ntohs(hdr_vlan->vlan.tci));
vlan_tag = net_pkt_vlan_tag(pkt);
}
}
#endif
if (net_recv_data(get_iface(slip, vlan_tag), pkt) < 0) {
net_pkt_unref(pkt);
}
slip->rx = NULL;
slip->last = NULL;
}
static inline int slip_input_byte(struct slip_context *slip,
unsigned char c)
{
switch (slip->state) {
case STATE_GARBAGE:
if (c == SLIP_END) {
slip->state = STATE_OK;
}
return 0;
case STATE_ESC:
if (c == SLIP_ESC_END) {
c = SLIP_END;
} else if (c == SLIP_ESC_ESC) {
c = SLIP_ESC;
} else {
slip->state = STATE_GARBAGE;
SLIP_STATS(slip->garbage++);
return 0;
}
slip->state = STATE_OK;
break;
case STATE_OK:
if (c == SLIP_ESC) {
slip->state = STATE_ESC;
return 0;
}
if (c == SLIP_END) {
slip->state = STATE_OK;
slip->first = false;
if (slip->rx) {
return 1;
}
return 0;
}
if (slip->first && !slip->rx) {
/* Must have missed buffer allocation on first byte. */
return 0;
}
if (!slip->first) {
slip->first = true;
slip->rx = net_pkt_rx_alloc_on_iface(slip->iface,
K_NO_WAIT);
if (!slip->rx) {
LOG_ERR("[%p] cannot allocate pkt", slip);
return 0;
}
slip->last = net_pkt_get_frag(slip->rx, SLIP_FRAG_LEN,
K_NO_WAIT);
if (!slip->last) {
LOG_ERR("[%p] cannot allocate 1st data buffer",
slip);
net_pkt_unref(slip->rx);
slip->rx = NULL;
return 0;
}
net_pkt_append_buffer(slip->rx, slip->last);
slip->ptr = net_pkt_ip_data(slip->rx);
}
break;
}
/* It is possible that slip->last is not set during the startup
* of the device. If this happens do not continue and overwrite
* some random memory.
*/
if (!slip->last) {
return 0;
}
if (!net_buf_tailroom(slip->last)) {
/* We need to allocate a new buffer */
struct net_buf *buf;
buf = net_pkt_get_reserve_rx_data(SLIP_FRAG_LEN, K_NO_WAIT);
if (!buf) {
LOG_ERR("[%p] cannot allocate next data buf", slip);
net_pkt_unref(slip->rx);
slip->rx = NULL;
slip->last = NULL;
return 0;
}
net_buf_frag_insert(slip->last, buf);
slip->last = buf;
slip->ptr = slip->last->data;
}
/* The net_buf_add_u8() cannot add data to ll header so we need
* a way to do it.
*/
if (slip->ptr < slip->last->data) {
*slip->ptr = c;
} else {
slip->ptr = net_buf_add_u8(slip->last, c);
}
slip->ptr++;
return 0;
}
static uint8_t *recv_cb(uint8_t *buf, size_t *off)
{
struct slip_context *slip =
CONTAINER_OF(buf, struct slip_context, buf[0]);
size_t i;
if (!slip->init_done) {
*off = 0;
return buf;
}
for (i = 0; i < *off; i++) {
if (slip_input_byte(slip, buf[i])) {
if (LOG_LEVEL >= LOG_LEVEL_DBG) {
struct net_buf *rx_buf = slip->rx->buffer;
int bytes = net_buf_frags_len(rx_buf);
int count = 0;
while (bytes && rx_buf) {
char msg[6 + 10 + 1];
snprintk(msg, sizeof(msg),
">slip %2d", count);
LOG_HEXDUMP_DBG(rx_buf->data, rx_buf->len,
msg);
rx_buf = rx_buf->frags;
count++;
}
LOG_DBG("[%p] received data %d bytes", slip,
bytes);
}
process_msg(slip);
break;
}
}
*off = 0;
return buf;
}
int slip_init(const struct device *dev)
{
struct slip_context *slip = dev->data;
LOG_DBG("[%p] dev %p", slip, dev);
slip->state = STATE_OK;
slip->rx = NULL;
slip->first = false;
#if defined(CONFIG_SLIP_TAP) && defined(CONFIG_NET_IPV4)
LOG_DBG("ARP enabled");
#endif
uart_pipe_register(slip->buf, sizeof(slip->buf), recv_cb);
return 0;
}
static inline struct net_linkaddr *slip_get_mac(struct slip_context *slip)
{
slip->ll_addr.addr = slip->mac_addr;
slip->ll_addr.len = sizeof(slip->mac_addr);
return &slip->ll_addr;
}
void slip_iface_init(struct net_if *iface)
{
struct slip_context *slip = net_if_get_device(iface)->data;
struct net_linkaddr *ll_addr;
#if defined(CONFIG_SLIP_TAP) && defined(CONFIG_NET_L2_ETHERNET)
ethernet_init(iface);
#endif
#if defined(CONFIG_NET_LLDP)
net_lldp_set_lldpdu(iface);
#endif
if (slip->init_done) {
return;
}
ll_addr = slip_get_mac(slip);
slip->init_done = true;
slip->iface = iface;
if (CONFIG_SLIP_MAC_ADDR[0] != 0) {
if (net_bytes_from_str(slip->mac_addr, sizeof(slip->mac_addr),
CONFIG_SLIP_MAC_ADDR) < 0) {
goto use_random_mac;
}
} else {
use_random_mac:
/* 00-00-5E-00-53-xx Documentation RFC 7042 */
slip->mac_addr[0] = 0x00;
slip->mac_addr[1] = 0x00;
slip->mac_addr[2] = 0x5E;
slip->mac_addr[3] = 0x00;
slip->mac_addr[4] = 0x53;
slip->mac_addr[5] = sys_rand8_get();
}
net_if_set_link_addr(iface, ll_addr->addr, ll_addr->len,
NET_LINK_ETHERNET);
}
#if !defined(CONFIG_SLIP_TAP)
static struct slip_context slip_context_data;
static const struct dummy_api slip_if_api = {
.iface_api.init = slip_iface_init,
.send = slip_send,
};
#define _SLIP_L2_LAYER DUMMY_L2
#define _SLIP_L2_CTX_TYPE NET_L2_GET_CTX_TYPE(DUMMY_L2)
NET_DEVICE_INIT(slip, CONFIG_SLIP_DRV_NAME, slip_init, NULL,
&slip_context_data, NULL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT,
&slip_if_api, _SLIP_L2_LAYER, _SLIP_L2_CTX_TYPE, _SLIP_MTU);
#endif