blob: 1e404730619ddf7566c19667ee65199b7efea559 [file] [log] [blame]
/**
* @file at.c
* Generic AT command handling library implementation
*/
/*
* Copyright (c) 2015-2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <stdarg.h>
#include <net/buf.h>
#include "at.h"
static void next_list(struct at_client *at)
{
if (at->buf[at->pos] == ',') {
at->pos++;
}
}
int at_check_byte(struct net_buf *buf, char check_byte)
{
const unsigned char *str = buf->data;
if (*str != check_byte) {
return -EINVAL;
}
net_buf_pull(buf, 1);
return 0;
}
static void skip_space(struct at_client *at)
{
while (at->buf[at->pos] == ' ') {
at->pos++;
}
}
int at_get_number(struct at_client *at, uint32_t *val)
{
uint32_t i;
skip_space(at);
for (i = 0, *val = 0; isdigit(at->buf[at->pos]); at->pos++, i++) {
*val = *val * 10 + at->buf[at->pos] - '0';
}
if (i == 0) {
return -ENODATA;
}
next_list(at);
return 0;
}
static bool str_has_prefix(const char *str, const char *prefix)
{
if (strncmp(str, prefix, strlen(prefix)) != 0) {
return false;
}
return true;
}
static int at_parse_result(const char *str, struct net_buf *buf,
enum at_result *result)
{
/* Map the result and check for end lf */
if ((!strncmp(str, "OK", 2)) && (at_check_byte(buf, '\n') == 0)) {
*result = AT_RESULT_OK;
return 0;
}
if ((!strncmp(str, "ERROR", 5)) && (at_check_byte(buf, '\n')) == 0) {
*result = AT_RESULT_ERROR;
return 0;
}
return -ENOMSG;
}
static int get_cmd_value(struct at_client *at, struct net_buf *buf,
char stop_byte, enum at_cmd_state cmd_state)
{
int cmd_len = 0;
uint8_t pos = at->pos;
const unsigned char *str = buf->data;
while (cmd_len < buf->len && at->pos != at->buf_max_len) {
if (*str != stop_byte) {
at->buf[at->pos++] = *str;
cmd_len++;
str++;
pos = at->pos;
} else {
cmd_len++;
at->buf[at->pos] = '\0';
at->pos = 0;
at->cmd_state = cmd_state;
break;
}
}
net_buf_pull(buf, cmd_len);
if (pos == at->buf_max_len) {
return -ENOBUFS;
}
return 0;
}
static int get_response_string(struct at_client *at, struct net_buf *buf,
char stop_byte, enum at_state state)
{
int cmd_len = 0;
uint8_t pos = at->pos;
const unsigned char *str = buf->data;
while (cmd_len < buf->len && at->pos != at->buf_max_len) {
if (*str != stop_byte) {
at->buf[at->pos++] = *str;
cmd_len++;
str++;
pos = at->pos;
} else {
cmd_len++;
at->buf[at->pos] = '\0';
at->pos = 0;
at->state = state;
break;
}
}
net_buf_pull(buf, cmd_len);
if (pos == at->buf_max_len) {
return -ENOBUFS;
}
return 0;
}
static void reset_buffer(struct at_client *at)
{
memset(at->buf, 0, at->buf_max_len);
at->pos = 0;
}
static int at_state_start(struct at_client *at, struct net_buf *buf)
{
int err;
err = at_check_byte(buf, '\r');
if (err < 0) {
return err;
}
at->state = AT_STATE_START_CR;
return 0;
}
static int at_state_start_cr(struct at_client *at, struct net_buf *buf)
{
int err;
err = at_check_byte(buf, '\n');
if (err < 0) {
return err;
}
at->state = AT_STATE_START_LF;
return 0;
}
static int at_state_start_lf(struct at_client *at, struct net_buf *buf)
{
reset_buffer(at);
if (at_check_byte(buf, '+') == 0) {
at->state = AT_STATE_GET_CMD_STRING;
return 0;
} else if (isalpha(*buf->data)) {
at->state = AT_STATE_GET_RESULT_STRING;
return 0;
}
return -ENODATA;
}
static int at_state_get_cmd_string(struct at_client *at, struct net_buf *buf)
{
return get_response_string(at, buf, ':', AT_STATE_PROCESS_CMD);
}
static bool is_cmer(struct at_client *at)
{
if (strncmp(at->buf, "CME ERROR", 9) == 0) {
return true;
}
return false;
}
static int at_state_process_cmd(struct at_client *at, struct net_buf *buf)
{
if (is_cmer(at)) {
at->state = AT_STATE_PROCESS_AG_NW_ERR;
return 0;
}
if (at->resp) {
at->resp(at, buf);
return 0;
}
at->state = AT_STATE_UNSOLICITED_CMD;
return 0;
}
static int at_state_get_result_string(struct at_client *at, struct net_buf *buf)
{
return get_response_string(at, buf, '\r', AT_STATE_PROCESS_RESULT);
}
static int at_state_process_result(struct at_client *at, struct net_buf *buf)
{
enum at_cme cme_err;
enum at_result result;
if (at_parse_result(at->buf, buf, &result) == 0) {
if (at->finish) {
/* cme_err is 0 - Is invalid until result is
* AT_RESULT_CME_ERROR
*/
cme_err = 0;
at->finish(at, result, cme_err);
}
}
/* Reset the state to process unsolicited response */
at->cmd_state = AT_CMD_START;
at->state = AT_STATE_START;
return 0;
}
int cme_handle(struct at_client *at)
{
enum at_cme cme_err;
int val;
if (!at_get_number(at, &val) && val <= CME_ERROR_NETWORK_NOT_ALLOWED) {
cme_err = val;
} else {
cme_err = CME_ERROR_UNKNOWN;
}
if (at->finish) {
at->finish(at, AT_RESULT_CME_ERROR, cme_err);
}
return 0;
}
static int at_state_process_ag_nw_err(struct at_client *at, struct net_buf *buf)
{
at->cmd_state = AT_CMD_GET_VALUE;
return at_parse_cmd_input(at, buf, NULL, cme_handle,
AT_CMD_TYPE_NORMAL);
}
static int at_state_unsolicited_cmd(struct at_client *at, struct net_buf *buf)
{
if (at->unsolicited) {
return at->unsolicited(at, buf);
}
return -ENODATA;
}
/* The order of handler function should match the enum at_state */
static handle_parse_input_t parser_cb[] = {
at_state_start, /* AT_STATE_START */
at_state_start_cr, /* AT_STATE_START_CR */
at_state_start_lf, /* AT_STATE_START_LF */
at_state_get_cmd_string, /* AT_STATE_GET_CMD_STRING */
at_state_process_cmd, /* AT_STATE_PROCESS_CMD */
at_state_get_result_string, /* AT_STATE_GET_RESULT_STRING */
at_state_process_result, /* AT_STATE_PROCESS_RESULT */
at_state_process_ag_nw_err, /* AT_STATE_PROCESS_AG_NW_ERR */
at_state_unsolicited_cmd /* AT_STATE_UNSOLICITED_CMD */
};
int at_parse_input(struct at_client *at, struct net_buf *buf)
{
int ret;
while (buf->len) {
if (at->state < AT_STATE_START || at->state >= AT_STATE_END) {
return -EINVAL;
}
ret = parser_cb[at->state](at, buf);
if (ret < 0) {
return ret;
}
}
return 0;
}
static int at_cmd_start(struct at_client *at, struct net_buf *buf,
const char *prefix, parse_val_t func,
enum at_cmd_type type)
{
if (!str_has_prefix(at->buf, prefix)) {
if (type == AT_CMD_TYPE_NORMAL) {
at->state = AT_STATE_UNSOLICITED_CMD;
}
return -ENODATA;
}
reset_buffer(at);
at->cmd_state = AT_CMD_GET_VALUE;
return 0;
}
static int at_cmd_get_value(struct at_client *at, struct net_buf *buf,
const char *prefix, parse_val_t func,
enum at_cmd_type type)
{
return get_cmd_value(at, buf, '\r', AT_CMD_PROCESS_VALUE);
}
static int at_cmd_process_value(struct at_client *at, struct net_buf *buf,
const char *prefix, parse_val_t func,
enum at_cmd_type type)
{
int ret;
ret = func(at);
at->cmd_state = AT_CMD_STATE_END_LF;
return ret;
}
static int at_cmd_state_end_lf(struct at_client *at, struct net_buf *buf,
const char *prefix, parse_val_t func,
enum at_cmd_type type)
{
int err;
err = at_check_byte(buf, '\n');
if (err < 0) {
return err;
}
at->cmd_state = AT_CMD_START;
at->state = AT_STATE_START;
return 0;
}
/* The order of handler function should match the enum at_cmd_state */
static handle_cmd_input_t cmd_parser_cb[] = {
at_cmd_start, /* AT_CMD_START */
at_cmd_get_value, /* AT_CMD_GET_VALUE */
at_cmd_process_value, /* AT_CMD_PROCESS_VALUE */
at_cmd_state_end_lf /* AT_CMD_STATE_END_LF */
};
int at_parse_cmd_input(struct at_client *at, struct net_buf *buf,
const char *prefix, parse_val_t func,
enum at_cmd_type type)
{
int ret;
while (buf->len) {
if (at->cmd_state < AT_CMD_START ||
at->cmd_state >= AT_CMD_STATE_END) {
return -EINVAL;
}
ret = cmd_parser_cb[at->cmd_state](at, buf, prefix, func, type);
if (ret < 0) {
return ret;
}
/* Check for main state, the end of cmd parsing and return. */
if (at->state == AT_STATE_START ||
(at->state == AT_STATE_UNSOLICITED_CMD &&
type == AT_CMD_TYPE_UNSOLICITED)) {
return 0;
}
}
return 0;
}
int at_has_next_list(struct at_client *at)
{
return at->buf[at->pos] != '\0';
}
int at_open_list(struct at_client *at)
{
skip_space(at);
/* The list shall start with '(' open parenthesis */
if (at->buf[at->pos] != '(') {
return -ENODATA;
}
at->pos++;
return 0;
}
int at_close_list(struct at_client *at)
{
skip_space(at);
if (at->buf[at->pos] != ')') {
return -ENODATA;
}
at->pos++;
next_list(at);
return 0;
}
int at_list_get_string(struct at_client *at, char *name, uint8_t len)
{
int i = 0;
skip_space(at);
if (at->buf[at->pos] != '"') {
return -ENODATA;
}
at->pos++;
while (at->buf[at->pos] != '\0' && at->buf[at->pos] != '"') {
if (i == len) {
return -ENODATA;
}
name[i++] = at->buf[at->pos++];
}
if (i == len) {
return -ENODATA;
}
name[i] = '\0';
if (at->buf[at->pos] != '"') {
return -ENODATA;
}
at->pos++;
skip_space(at);
next_list(at);
return 0;
}
int at_list_get_range(struct at_client *at, uint32_t *min, uint32_t *max)
{
uint32_t low, high;
int ret;
ret = at_get_number(at, &low);
if (ret < 0) {
return ret;
}
if (at->buf[at->pos] == '-') {
at->pos++;
goto out;
}
if (!isdigit(at->buf[at->pos])) {
return -ENODATA;
}
out:
ret = at_get_number(at, &high);
if (ret < 0) {
return ret;
}
*min = low;
*max = high;
next_list(at);
return 0;
}
void at_register_unsolicited(struct at_client *at, at_resp_cb_t unsolicited)
{
at->unsolicited = unsolicited;
}
void at_register(struct at_client *at, at_resp_cb_t resp, at_finish_cb_t finish)
{
at->resp = resp;
at->finish = finish;
at->state = AT_STATE_START;
}