blob: 67ebc0f3b0c00cb90fc188b8bf6cced25414bb7a [file] [log] [blame] [edit]
/*
* Copyright (c) 2019 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
*
* PPP driver using uart_pipe. This is meant for network connectivity between
* two network end points.
*/
#define LOG_LEVEL CONFIG_NET_PPP_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(net_ppp, LOG_LEVEL);
#include <stdio.h>
#include <zephyr/kernel.h>
#include <stdbool.h>
#include <errno.h>
#include <stddef.h>
#include <zephyr/net/ppp.h>
#include <zephyr/net/buf.h>
#include <zephyr/net/net_pkt.h>
#include <zephyr/net/net_if.h>
#include <zephyr/net/net_core.h>
#include <zephyr/sys/ring_buffer.h>
#include <zephyr/sys/crc.h>
#include <zephyr/drivers/uart.h>
#include <zephyr/drivers/console/uart_mux.h>
#include <zephyr/random/rand32.h>
#include "../../subsys/net/ip/net_stats.h"
#include "../../subsys/net/ip/net_private.h"
#define UART_BUF_LEN CONFIG_NET_PPP_UART_BUF_LEN
#define UART_TX_BUF_LEN CONFIG_NET_PPP_ASYNC_UART_TX_BUF_LEN
enum ppp_driver_state {
STATE_HDLC_FRAME_START,
STATE_HDLC_FRAME_ADDRESS,
STATE_HDLC_FRAME_DATA,
};
#define PPP_WORKQ_PRIORITY CONFIG_NET_PPP_RX_PRIORITY
#define PPP_WORKQ_STACK_SIZE CONFIG_NET_PPP_RX_STACK_SIZE
K_KERNEL_STACK_DEFINE(ppp_workq, PPP_WORKQ_STACK_SIZE);
struct ppp_driver_context {
const struct device *dev;
struct net_if *iface;
/* This net_pkt contains pkt that is being read */
struct net_pkt *pkt;
/* How much free space we have in the net_pkt */
size_t available;
/* ppp data is read into this buf */
uint8_t buf[UART_BUF_LEN];
#if defined(CONFIG_NET_PPP_ASYNC_UART)
/* with async we use 2 rx buffers */
uint8_t buf2[UART_BUF_LEN];
struct k_work_delayable uart_recovery_work;
/* ppp buf use when sending data */
uint8_t send_buf[UART_TX_BUF_LEN];
#else
/* ppp buf use when sending data */
uint8_t send_buf[UART_BUF_LEN];
#endif
uint8_t mac_addr[6];
struct net_linkaddr ll_addr;
/* Flag that tells whether this instance is initialized or not */
atomic_t modem_init_done;
/* Incoming data is routed via ring buffer */
struct ring_buf rx_ringbuf;
uint8_t rx_buf[CONFIG_NET_PPP_RINGBUF_SIZE];
/* ISR function callback worker */
struct k_work cb_work;
struct k_work_q cb_workq;
#if defined(CONFIG_NET_STATISTICS_PPP)
struct net_stats_ppp stats;
#endif
enum ppp_driver_state state;
#if defined(CONFIG_PPP_CLIENT_CLIENTSERVER)
/* correctly received CLIENT bytes */
uint8_t client_index;
#endif
uint8_t init_done : 1;
uint8_t next_escaped : 1;
};
static struct ppp_driver_context ppp_driver_context_data;
#if defined(CONFIG_NET_PPP_ASYNC_UART)
static bool rx_retry_pending;
static bool uart_recovery_pending;
static uint8_t *next_buf;
static K_SEM_DEFINE(uarte_tx_finished, 0, 1);
static void uart_callback(const struct device *dev,
struct uart_event *evt,
void *user_data)
{
struct ppp_driver_context *context = user_data;
uint8_t *p;
int err, ret, len, space_left;
switch (evt->type) {
case UART_TX_DONE:
LOG_DBG("UART_TX_DONE: sent %d bytes", evt->data.tx.len);
k_sem_give(&uarte_tx_finished);
break;
case UART_TX_ABORTED:
LOG_DBG("Tx aborted");
k_sem_give(&uarte_tx_finished);
break;
case UART_RX_RDY:
len = evt->data.rx.len;
p = evt->data.rx.buf + evt->data.rx.offset;
LOG_DBG("Received data %d bytes", len);
ret = ring_buf_put(&context->rx_ringbuf, p, len);
if (ret < evt->data.rx.len) {
LOG_WRN("Rx buffer doesn't have enough space. "
"Bytes pending: %d, written only: %d. "
"Disabling RX for now.",
evt->data.rx.len, ret);
/* No possibility to set flow ctrl ON towards PC,
* thus workrounding this lack in async API by turning
* rx off for now and re-enabling that later.
*/
if (!rx_retry_pending) {
uart_rx_disable(dev);
rx_retry_pending = true;
}
}
space_left = ring_buf_space_get(&context->rx_ringbuf);
if (!rx_retry_pending && space_left < (sizeof(context->rx_buf) / 8)) {
/* Not much room left in buffer after a write to ring buffer.
* We submit a work, but enable flow ctrl also
* in this case to avoid packet losses.
*/
uart_rx_disable(dev);
rx_retry_pending = true;
LOG_WRN("%d written to RX buf, but after that only %d space left. "
"Disabling RX for now.",
ret, space_left);
}
k_work_submit_to_queue(&context->cb_workq, &context->cb_work);
break;
case UART_RX_BUF_REQUEST:
{
LOG_DBG("UART_RX_BUF_REQUEST: buf %p", next_buf);
if (next_buf) {
err = uart_rx_buf_rsp(dev, next_buf, sizeof(context->buf));
if (err) {
LOG_ERR("uart_rx_buf_rsp() err: %d", err);
}
}
break;
}
case UART_RX_BUF_RELEASED:
next_buf = evt->data.rx_buf.buf;
LOG_DBG("UART_RX_BUF_RELEASED: buf %p", next_buf);
break;
case UART_RX_DISABLED:
LOG_DBG("UART_RX_DISABLED - re-enabling in a while");
if (rx_retry_pending && !uart_recovery_pending) {
k_work_schedule(&context->uart_recovery_work,
K_MSEC(CONFIG_NET_PPP_ASYNC_UART_RX_RECOVERY_TIMEOUT));
rx_retry_pending = false;
uart_recovery_pending = true;
}
break;
case UART_RX_STOPPED:
LOG_DBG("UART_RX_STOPPED: stop reason %d", evt->data.rx_stop.reason);
if (evt->data.rx_stop.reason != 0) {
rx_retry_pending = true;
}
break;
}
}
static int ppp_async_uart_rx_enable(struct ppp_driver_context *context)
{
int err;
next_buf = context->buf2;
err = uart_callback_set(context->dev, uart_callback, (void *)context);
if (err) {
LOG_ERR("Failed to set uart callback, err %d", err);
}
err = uart_rx_enable(context->dev, context->buf, sizeof(context->buf),
CONFIG_NET_PPP_ASYNC_UART_RX_ENABLE_TIMEOUT * USEC_PER_MSEC);
if (err) {
LOG_ERR("uart_rx_enable() failed, err %d", err);
} else {
LOG_DBG("RX enabled");
}
rx_retry_pending = false;
return err;
}
static void uart_recovery(struct k_work *work)
{
struct ppp_driver_context *ppp =
CONTAINER_OF(work, struct ppp_driver_context, uart_recovery_work);
int ret;
ret = ring_buf_space_get(&ppp->rx_ringbuf);
if (ret >= (sizeof(ppp->rx_buf) / 2)) {
ret = ppp_async_uart_rx_enable(ppp);
if (ret) {
LOG_ERR("ppp_async_uart_rx_enable() failed, err %d", ret);
} else {
LOG_WRN("UART RX recovered");
}
uart_recovery_pending = false;
} else {
LOG_ERR("Rx buffer still doesn't have enough room %d to be re-enabled", ret);
k_work_schedule(&ppp->uart_recovery_work,
K_MSEC(CONFIG_NET_PPP_ASYNC_UART_RX_RECOVERY_TIMEOUT));
}
}
#endif
static int ppp_save_byte(struct ppp_driver_context *ppp, uint8_t byte)
{
int ret;
if (!ppp->pkt) {
ppp->pkt = net_pkt_rx_alloc_with_buffer(
ppp->iface,
CONFIG_NET_BUF_DATA_SIZE,
AF_UNSPEC, 0, K_NO_WAIT);
if (!ppp->pkt) {
LOG_ERR("[%p] cannot allocate pkt", ppp);
return -ENOMEM;
}
net_pkt_cursor_init(ppp->pkt);
ppp->available = net_pkt_available_buffer(ppp->pkt);
}
/* Extra debugging can be enabled separately if really
* needed. Normally it would just print too much data.
*/
if (0) {
LOG_DBG("Saving byte %02x", byte);
}
/* This is not very intuitive but we must allocate new buffer
* before we write a byte to last available cursor position.
*/
if (ppp->available == 1) {
ret = net_pkt_alloc_buffer(ppp->pkt,
CONFIG_NET_BUF_DATA_SIZE,
AF_UNSPEC, K_NO_WAIT);
if (ret < 0) {
LOG_ERR("[%p] cannot allocate new data buffer", ppp);
goto out_of_mem;
}
ppp->available = net_pkt_available_buffer(ppp->pkt);
}
if (ppp->available) {
ret = net_pkt_write_u8(ppp->pkt, byte);
if (ret < 0) {
LOG_ERR("[%p] Cannot write to pkt %p (%d)",
ppp, ppp->pkt, ret);
goto out_of_mem;
}
ppp->available--;
}
return 0;
out_of_mem:
net_pkt_unref(ppp->pkt);
ppp->pkt = NULL;
return -ENOMEM;
}
static const char *ppp_driver_state_str(enum ppp_driver_state state)
{
#if (CONFIG_NET_PPP_LOG_LEVEL >= LOG_LEVEL_DBG)
switch (state) {
case STATE_HDLC_FRAME_START:
return "START";
case STATE_HDLC_FRAME_ADDRESS:
return "ADDRESS";
case STATE_HDLC_FRAME_DATA:
return "DATA";
}
#else
ARG_UNUSED(state);
#endif
return "";
}
static void ppp_change_state(struct ppp_driver_context *ctx,
enum ppp_driver_state new_state)
{
NET_ASSERT(ctx);
if (ctx->state == new_state) {
return;
}
NET_ASSERT(new_state >= STATE_HDLC_FRAME_START &&
new_state <= STATE_HDLC_FRAME_DATA);
NET_DBG("[%p] state %s (%d) => %s (%d)",
ctx, ppp_driver_state_str(ctx->state), ctx->state,
ppp_driver_state_str(new_state), new_state);
ctx->state = new_state;
}
static int ppp_send_flush(struct ppp_driver_context *ppp, int off)
{
if (IS_ENABLED(CONFIG_NET_TEST)) {
return 0;
}
uint8_t *buf = ppp->send_buf;
/* If we're using gsm_mux, We don't want to use poll_out because sending
* one byte at a time causes each byte to get wrapped in muxing headers.
* But we can safely call uart_fifo_fill outside of ISR context when
* muxing because uart_mux implements it in software.
*/
if (IS_ENABLED(CONFIG_GSM_MUX)) {
(void)uart_fifo_fill(ppp->dev, buf, off);
} else if (IS_ENABLED(CONFIG_NET_PPP_ASYNC_UART)) {
#if defined(CONFIG_NET_PPP_ASYNC_UART)
int ret;
k_sem_take(&uarte_tx_finished, K_FOREVER);
ret = uart_tx(ppp->dev, buf, off,
CONFIG_NET_PPP_ASYNC_UART_TX_TIMEOUT * USEC_PER_MSEC);
if (ret) {
LOG_ERR("uart_tx() failed, err %d", ret);
k_sem_give(&uarte_tx_finished);
}
#endif
} else {
while (off--) {
uart_poll_out(ppp->dev, *buf++);
}
}
return 0;
}
static int ppp_send_bytes(struct ppp_driver_context *ppp,
const uint8_t *data, int len, int off)
{
int i;
for (i = 0; i < len; i++) {
ppp->send_buf[off++] = data[i];
if (off >= sizeof(ppp->send_buf)) {
off = ppp_send_flush(ppp, off);
}
}
return off;
}
#if defined(CONFIG_PPP_CLIENT_CLIENTSERVER)
#define CLIENT "CLIENT"
#define CLIENTSERVER "CLIENTSERVER"
static void ppp_handle_client(struct ppp_driver_context *ppp, uint8_t byte)
{
static const char *client = CLIENT;
static const char *clientserver = CLIENTSERVER;
int offset;
if (ppp->client_index >= (sizeof(CLIENT) - 1)) {
ppp->client_index = 0;
}
if (byte != client[ppp->client_index]) {
ppp->client_index = 0;
if (byte != client[ppp->client_index]) {
return;
}
}
++ppp->client_index;
if (ppp->client_index >= (sizeof(CLIENT) - 1)) {
LOG_DBG("Received complete CLIENT string");
offset = ppp_send_bytes(ppp, clientserver,
sizeof(CLIENTSERVER) - 1, 0);
(void)ppp_send_flush(ppp, offset);
ppp->client_index = 0;
}
}
#endif
static int ppp_input_byte(struct ppp_driver_context *ppp, uint8_t byte)
{
int ret = -EAGAIN;
switch (ppp->state) {
case STATE_HDLC_FRAME_START:
/* Synchronizing the flow with HDLC flag field */
if (byte == 0x7e) {
/* Note that we do not save the sync flag */
LOG_DBG("Sync byte (0x%02x) start", byte);
ppp_change_state(ppp, STATE_HDLC_FRAME_ADDRESS);
#if defined(CONFIG_PPP_CLIENT_CLIENTSERVER)
} else {
ppp_handle_client(ppp, byte);
#endif
}
break;
case STATE_HDLC_FRAME_ADDRESS:
if (byte != 0xff) {
/* Check if we need to sync again */
if (byte == 0x7e) {
/* Just skip to the start of the pkt byte */
return -EAGAIN;
}
LOG_DBG("Invalid (0x%02x) byte, expecting Address",
byte);
/* If address is != 0xff, then ignore this
* frame. RFC 1662 ch 3.1
*/
ppp_change_state(ppp, STATE_HDLC_FRAME_START);
} else {
LOG_DBG("Address byte (0x%02x) start", byte);
ppp_change_state(ppp, STATE_HDLC_FRAME_DATA);
/* Save the address field so that we can calculate
* the FCS. The address field will not be passed
* to upper stack.
*/
ret = ppp_save_byte(ppp, byte);
if (ret < 0) {
ppp_change_state(ppp, STATE_HDLC_FRAME_START);
}
ret = -EAGAIN;
}
break;
case STATE_HDLC_FRAME_DATA:
/* If the next frame starts, then send this one
* up in the network stack.
*/
if (byte == 0x7e) {
LOG_DBG("End of pkt (0x%02x)", byte);
ppp_change_state(ppp, STATE_HDLC_FRAME_ADDRESS);
ret = 0;
} else {
if (byte == 0x7d) {
/* RFC 1662, ch. 4.2 */
ppp->next_escaped = true;
break;
}
if (ppp->next_escaped) {
/* RFC 1662, ch. 4.2 */
byte ^= 0x20;
ppp->next_escaped = false;
}
ret = ppp_save_byte(ppp, byte);
if (ret < 0) {
ppp_change_state(ppp, STATE_HDLC_FRAME_START);
}
ret = -EAGAIN;
}
break;
default:
LOG_ERR("[%p] Invalid state %d", ppp, ppp->state);
break;
}
return ret;
}
static bool ppp_check_fcs(struct ppp_driver_context *ppp)
{
struct net_buf *buf;
uint16_t crc;
buf = ppp->pkt->buffer;
if (!buf) {
return false;
}
crc = crc16_ccitt(0xffff, buf->data, buf->len);
buf = buf->frags;
while (buf) {
crc = crc16_ccitt(crc, buf->data, buf->len);
buf = buf->frags;
}
if (crc != 0xf0b8) {
LOG_DBG("Invalid FCS (0x%x)", crc);
#if defined(CONFIG_NET_STATISTICS_PPP)
ppp->stats.chkerr++;
#endif
return false;
}
return true;
}
static void ppp_process_msg(struct ppp_driver_context *ppp)
{
if (LOG_LEVEL >= LOG_LEVEL_DBG) {
net_pkt_hexdump(ppp->pkt, "recv ppp");
}
if (IS_ENABLED(CONFIG_NET_PPP_VERIFY_FCS) && !ppp_check_fcs(ppp)) {
#if defined(CONFIG_NET_STATISTICS_PPP)
ppp->stats.drop++;
ppp->stats.pkts.rx++;
#endif
net_pkt_unref(ppp->pkt);
} else {
/* Remove the Address (0xff), Control (0x03) and
* FCS fields (16-bit) as the PPP L2 layer does not need
* those bytes.
*/
uint16_t addr_and_ctrl = net_buf_pull_be16(ppp->pkt->buffer);
/* Currently we do not support compressed Address and Control
* fields so they must always be present.
*/
if (addr_and_ctrl != (0xff << 8 | 0x03)) {
#if defined(CONFIG_NET_STATISTICS_PPP)
ppp->stats.drop++;
ppp->stats.pkts.rx++;
#endif
net_pkt_unref(ppp->pkt);
} else {
/* Remove FCS bytes (2) */
net_pkt_remove_tail(ppp->pkt, 2);
/* Make sure we now start reading from PPP header in
* PPP L2 recv()
*/
net_pkt_cursor_init(ppp->pkt);
net_pkt_set_overwrite(ppp->pkt, true);
if (net_recv_data(ppp->iface, ppp->pkt) < 0) {
net_pkt_unref(ppp->pkt);
}
}
}
ppp->pkt = NULL;
}
#if defined(CONFIG_NET_TEST)
static uint8_t *ppp_recv_cb(uint8_t *buf, size_t *off)
{
struct ppp_driver_context *ppp =
CONTAINER_OF(buf, struct ppp_driver_context, buf);
size_t i, len = *off;
for (i = 0; i < *off; i++) {
if (0) {
/* Extra debugging can be enabled separately if really
* needed. Normally it would just print too much data.
*/
LOG_DBG("[%zd] %02x", i, buf[i]);
}
if (ppp_input_byte(ppp, buf[i]) == 0) {
/* Ignore empty or too short frames */
if (ppp->pkt && net_pkt_get_len(ppp->pkt) > 3) {
ppp_process_msg(ppp);
break;
}
}
}
if (i == *off) {
*off = 0;
} else {
*off = len - i - 1;
memmove(&buf[0], &buf[i + 1], *off);
}
return buf;
}
void ppp_driver_feed_data(uint8_t *data, int data_len)
{
struct ppp_driver_context *ppp = &ppp_driver_context_data;
size_t recv_off = 0;
/* We are expecting that the tests are feeding data in large
* chunks so we can reset the uart buffer here.
*/
memset(ppp->buf, 0, UART_BUF_LEN);
ppp_change_state(ppp, STATE_HDLC_FRAME_START);
while (data_len > 0) {
int data_to_copy = MIN(data_len, UART_BUF_LEN);
int remaining;
LOG_DBG("Feeding %d bytes", data_to_copy);
memcpy(ppp->buf, data, data_to_copy);
recv_off = data_to_copy;
(void)ppp_recv_cb(ppp->buf, &recv_off);
remaining = data_to_copy - recv_off;
LOG_DBG("We copied %d bytes", remaining);
data_len -= remaining;
data += remaining;
}
}
#endif
static bool calc_fcs(struct net_pkt *pkt, uint16_t *fcs, uint16_t protocol)
{
struct net_buf *buf;
uint16_t crc;
uint16_t c;
buf = pkt->buffer;
if (!buf) {
return false;
}
/* HDLC Address and Control fields */
c = sys_cpu_to_be16(0xff << 8 | 0x03);
crc = crc16_ccitt(0xffff, (const uint8_t *)&c, sizeof(c));
if (protocol > 0) {
crc = crc16_ccitt(crc, (const uint8_t *)&protocol,
sizeof(protocol));
}
while (buf) {
crc = crc16_ccitt(crc, buf->data, buf->len);
buf = buf->frags;
}
crc ^= 0xffff;
*fcs = crc;
return true;
}
static uint16_t ppp_escape_byte(uint8_t byte, int *offset)
{
if (byte == 0x7e || byte == 0x7d || byte < 0x20) {
*offset = 0;
return (0x7d << 8) | (byte ^ 0x20);
}
*offset = 1;
return byte;
}
static int ppp_send(const struct device *dev, struct net_pkt *pkt)
{
struct ppp_driver_context *ppp = dev->data;
struct net_buf *buf = pkt->buffer;
uint16_t protocol = 0;
int send_off = 0;
uint32_t sync_addr_ctrl;
uint16_t fcs, escaped;
uint8_t byte;
int i, offset;
#if defined(CONFIG_NET_TEST)
return 0;
#endif
ARG_UNUSED(dev);
if (!buf) {
/* No data? */
return -ENODATA;
}
/* If the packet is a normal network packet, we must add the protocol
* value here.
*/
if (!net_pkt_is_ppp(pkt)) {
if (net_pkt_family(pkt) == AF_INET) {
protocol = htons(PPP_IP);
} else if (net_pkt_family(pkt) == AF_INET6) {
protocol = htons(PPP_IPV6);
} else {
return -EPROTONOSUPPORT;
}
}
if (!calc_fcs(pkt, &fcs, protocol)) {
return -ENOMEM;
}
/* Sync, Address & Control fields */
sync_addr_ctrl = sys_cpu_to_be32(0x7e << 24 | 0xff << 16 |
0x7d << 8 | 0x23);
send_off = ppp_send_bytes(ppp, (const uint8_t *)&sync_addr_ctrl,
sizeof(sync_addr_ctrl), send_off);
if (protocol > 0) {
escaped = htons(ppp_escape_byte(protocol, &offset));
send_off = ppp_send_bytes(ppp, (uint8_t *)&escaped + offset,
offset ? 1 : 2,
send_off);
escaped = htons(ppp_escape_byte(protocol >> 8, &offset));
send_off = ppp_send_bytes(ppp, (uint8_t *)&escaped + offset,
offset ? 1 : 2,
send_off);
}
/* Note that we do not print the first four bytes and FCS bytes at the
* end so that we do not need to allocate separate net_buf just for
* that purpose.
*/
if (LOG_LEVEL >= LOG_LEVEL_DBG) {
net_pkt_hexdump(pkt, "send ppp");
}
while (buf) {
for (i = 0; i < buf->len; i++) {
/* Escape illegal bytes */
escaped = htons(ppp_escape_byte(buf->data[i], &offset));
send_off = ppp_send_bytes(ppp,
(uint8_t *)&escaped + offset,
offset ? 1 : 2,
send_off);
}
buf = buf->frags;
}
escaped = htons(ppp_escape_byte(fcs, &offset));
send_off = ppp_send_bytes(ppp, (uint8_t *)&escaped + offset,
offset ? 1 : 2,
send_off);
escaped = htons(ppp_escape_byte(fcs >> 8, &offset));
send_off = ppp_send_bytes(ppp, (uint8_t *)&escaped + offset,
offset ? 1 : 2,
send_off);
byte = 0x7e;
send_off = ppp_send_bytes(ppp, &byte, 1, send_off);
(void)ppp_send_flush(ppp, send_off);
return 0;
}
#if !defined(CONFIG_NET_TEST)
static int ppp_consume_ringbuf(struct ppp_driver_context *ppp)
{
uint8_t *data;
size_t len, tmp;
int ret;
len = ring_buf_get_claim(&ppp->rx_ringbuf, &data,
CONFIG_NET_PPP_RINGBUF_SIZE);
if (len == 0) {
LOG_DBG("Ringbuf %p is empty!", &ppp->rx_ringbuf);
return 0;
}
/* This will print too much data, enable only if really needed */
if (0) {
LOG_HEXDUMP_DBG(data, len, ppp->dev->name);
}
tmp = len;
do {
if (ppp_input_byte(ppp, *data++) == 0) {
/* Ignore empty or too short frames */
if (ppp->pkt && net_pkt_get_len(ppp->pkt) > 3) {
ppp_process_msg(ppp);
}
}
} while (--tmp);
ret = ring_buf_get_finish(&ppp->rx_ringbuf, len);
if (ret < 0) {
LOG_DBG("Cannot flush ring buffer (%d)", ret);
}
return -EAGAIN;
}
static void ppp_isr_cb_work(struct k_work *work)
{
struct ppp_driver_context *ppp =
CONTAINER_OF(work, struct ppp_driver_context, cb_work);
int ret = -EAGAIN;
while (ret == -EAGAIN) {
ret = ppp_consume_ringbuf(ppp);
}
}
#endif /* !CONFIG_NET_TEST */
static int ppp_driver_init(const struct device *dev)
{
struct ppp_driver_context *ppp = dev->data;
LOG_DBG("[%p] dev %p", ppp, dev);
#if !defined(CONFIG_NET_TEST)
ring_buf_init(&ppp->rx_ringbuf, sizeof(ppp->rx_buf), ppp->rx_buf);
k_work_init(&ppp->cb_work, ppp_isr_cb_work);
k_work_queue_start(&ppp->cb_workq, ppp_workq,
K_KERNEL_STACK_SIZEOF(ppp_workq),
K_PRIO_COOP(PPP_WORKQ_PRIORITY), NULL);
k_thread_name_set(&ppp->cb_workq.thread, "ppp_workq");
#if defined(CONFIG_NET_PPP_ASYNC_UART)
k_work_init_delayable(&ppp->uart_recovery_work, uart_recovery);
#endif
#endif
ppp->pkt = NULL;
ppp_change_state(ppp, STATE_HDLC_FRAME_START);
#if defined(CONFIG_PPP_CLIENT_CLIENTSERVER)
ppp->client_index = 0;
#endif
return 0;
}
static inline struct net_linkaddr *ppp_get_mac(struct ppp_driver_context *ppp)
{
ppp->ll_addr.addr = ppp->mac_addr;
ppp->ll_addr.len = sizeof(ppp->mac_addr);
return &ppp->ll_addr;
}
static void ppp_iface_init(struct net_if *iface)
{
struct ppp_driver_context *ppp = net_if_get_device(iface)->data;
struct net_linkaddr *ll_addr;
LOG_DBG("[%p] iface %p", ppp, iface);
net_ppp_init(iface);
if (ppp->init_done) {
return;
}
ppp->init_done = true;
ppp->iface = iface;
/* The mac address is not really used but network interface expects
* to find one.
*/
ll_addr = ppp_get_mac(ppp);
if (CONFIG_PPP_MAC_ADDR[0] != 0) {
if (net_bytes_from_str(ppp->mac_addr, sizeof(ppp->mac_addr),
CONFIG_PPP_MAC_ADDR) < 0) {
goto use_random_mac;
}
} else {
use_random_mac:
/* 00-00-5E-00-53-xx Documentation RFC 7042 */
ppp->mac_addr[0] = 0x00;
ppp->mac_addr[1] = 0x00;
ppp->mac_addr[2] = 0x5E;
ppp->mac_addr[3] = 0x00;
ppp->mac_addr[4] = 0x53;
ppp->mac_addr[5] = sys_rand32_get();
}
net_if_set_link_addr(iface, ll_addr->addr, ll_addr->len,
NET_LINK_ETHERNET);
memset(ppp->buf, 0, sizeof(ppp->buf));
/* If we have a GSM modem with PPP support or interface autostart is disabled
* from Kconfig, then do not start the interface automatically but only
* after the modem is ready or when manually started.
*/
if (IS_ENABLED(CONFIG_MODEM_GSM_PPP) ||
IS_ENABLED(CONFIG_PPP_NET_IF_NO_AUTO_START)) {
net_if_flag_set(iface, NET_IF_NO_AUTO_START);
}
}
#if defined(CONFIG_NET_STATISTICS_PPP)
static struct net_stats_ppp *ppp_get_stats(const struct device *dev)
{
struct ppp_driver_context *context = dev->data;
return &context->stats;
}
#endif
#if !defined(CONFIG_NET_TEST) && !defined(CONFIG_NET_PPP_ASYNC_UART)
static void ppp_uart_flush(const struct device *dev)
{
uint8_t c;
while (uart_fifo_read(dev, &c, 1) > 0) {
continue;
}
}
static void ppp_uart_isr(const struct device *uart, void *user_data)
{
struct ppp_driver_context *context = user_data;
int rx = 0, ret;
/* get all of the data off UART as fast as we can */
while (uart_irq_update(uart) && uart_irq_rx_ready(uart)) {
rx = uart_fifo_read(uart, context->buf, sizeof(context->buf));
if (rx <= 0) {
continue;
}
ret = ring_buf_put(&context->rx_ringbuf, context->buf, rx);
if (ret < rx) {
LOG_ERR("Rx buffer doesn't have enough space. "
"Bytes pending: %d, written: %d",
rx, ret);
break;
}
k_work_submit_to_queue(&context->cb_workq, &context->cb_work);
}
}
#endif /* !CONFIG_NET_TEST && !CONFIG_NET_PPP_ASYNC_UART */
static int ppp_start(const struct device *dev)
{
struct ppp_driver_context *context = dev->data;
/* Init the PPP UART only once. This should only be done after
* the GSM muxing is setup and enabled. GSM modem will call this
* after everything is ready to be connected.
*/
#if !defined(CONFIG_NET_TEST)
if (atomic_cas(&context->modem_init_done, false, true)) {
/* Now try to figure out what device to open. If GSM muxing
* is enabled, then use it. If not, then check if modem
* configuration is enabled, and use that. If none are enabled,
* then use our own config.
*/
#if defined(CONFIG_GSM_MUX)
const struct device *mux;
mux = uart_mux_find(CONFIG_GSM_MUX_DLCI_PPP);
if (mux == NULL) {
LOG_ERR("Cannot find GSM mux dev for DLCI %d",
CONFIG_GSM_MUX_DLCI_PPP);
return -ENOENT;
}
context->dev = mux;
#elif IS_ENABLED(CONFIG_MODEM_GSM_PPP)
context->dev = DEVICE_DT_GET(DT_BUS(DT_INST(0, zephyr_gsm_ppp)));
#else
/* dts chosen zephyr,ppp-uart case */
context->dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_ppp_uart));
#endif
LOG_INF("Initializing PPP to use %s", context->dev->name);
if (!device_is_ready(context->dev)) {
LOG_ERR("Device %s is not ready", context->dev->name);
return -ENODEV;
}
#if defined(CONFIG_NET_PPP_ASYNC_UART)
k_sem_give(&uarte_tx_finished);
ppp_async_uart_rx_enable(context);
#else
uart_irq_rx_disable(context->dev);
uart_irq_tx_disable(context->dev);
ppp_uart_flush(context->dev);
uart_irq_callback_user_data_set(context->dev, ppp_uart_isr,
context);
uart_irq_rx_enable(context->dev);
#endif
}
#endif /* !CONFIG_NET_TEST */
net_ppp_carrier_on(context->iface);
return 0;
}
static int ppp_stop(const struct device *dev)
{
struct ppp_driver_context *context = dev->data;
net_ppp_carrier_off(context->iface);
context->modem_init_done = false;
return 0;
}
static const struct ppp_api ppp_if_api = {
.iface_api.init = ppp_iface_init,
.send = ppp_send,
.start = ppp_start,
.stop = ppp_stop,
#if defined(CONFIG_NET_STATISTICS_PPP)
.get_stats = ppp_get_stats,
#endif
};
NET_DEVICE_INIT(ppp, CONFIG_NET_PPP_DRV_NAME, ppp_driver_init,
NULL, &ppp_driver_context_data, NULL,
CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, &ppp_if_api,
PPP_L2, NET_L2_GET_CTX_TYPE(PPP_L2), PPP_MTU);