kore-jsonrtc/jsonrtc/src/jsonrtc.c

/* 
 * This file is part of the jsonrtc.
 * written in 2018 by Helmut Pozimski.
 * 
 * This program is free software: you can redistribute it and/or modify  
 * it under the terms of the GNU General Public License as published by  
 * the Free Software Foundation, version 2.
 *
 * This program is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <kore/kore.h>
#include <kore/http.h>

#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include <linux/rtc.h>
#include <cjson/cJSON.h>

#define IOCTL_DS13307_ALRM _IOR('p', 0x15, unsigned char)

int		page(struct http_request *);
int handle_time(struct http_request *);
int handle_wkalrm(struct http_request *);
int detect_device(struct http_request *);
int handle_nvmem(struct http_request *);

int
page(struct http_request *req)
{
	http_response(req, 200, NULL, 0);
	return (KORE_RESULT_OK);
}

static char * read_body(struct http_request *req) {
	int ret;
	struct kore_buf * buf;
	u_int8_t data[128];
	char * body;
	buf = kore_buf_alloc(128);
	while(1) {
		ret = http_body_read(req, data, sizeof(data));
		if (ret == -1) {
			kore_buf_free(buf);
			return NULL;
                } else if (ret == 0) {
			break;
                }
			kore_buf_append(buf,data,ret);
	}
	body = kore_buf_stringify(buf, NULL);
        kore_buf_free(buf);
	return body;
}

int handle_time(struct http_request *req) {
	int fdesc;
	struct rtc_time time;
	int ret;
	char *result_string;
	cJSON *time_json, *json_min, *json_hour, *json_mday,
		*json_mon, *json_year, *json_sec, *json_wday;
	if(req->method == HTTP_METHOD_GET) {
		time_json = cJSON_CreateObject();
		fdesc = open("/dev/rtc", O_RDONLY);
		ret = ioctl(fdesc, RTC_RD_TIME, &time);
		close(fdesc);
		if (!ret) {
			json_sec = cJSON_CreateNumber(time.tm_sec);
			json_min = cJSON_CreateNumber(time.tm_min);
			json_hour = cJSON_CreateNumber(time.tm_hour);
			json_mday = cJSON_CreateNumber(time.tm_mday);
			json_mon = cJSON_CreateNumber(time.tm_mon);
			json_year = cJSON_CreateNumber(time.tm_year);
			json_wday = cJSON_CreateNumber(time.tm_wday);
			cJSON_AddItemToObject(time_json, "seconds", json_sec);
			cJSON_AddItemToObject(time_json, "minutes", json_min);
			cJSON_AddItemToObject(time_json, "hour", json_hour);
			cJSON_AddItemToObject(time_json, "mday", json_mday);
			cJSON_AddItemToObject(time_json, "month", json_mon);
			cJSON_AddItemToObject(time_json, "year", json_year);
			cJSON_AddItemToObject(time_json, "wday", json_wday);
			result_string = cJSON_Print(time_json);
			cJSON_Delete(time_json);
			http_response_header(req, "Content-Type", "application/json");
            http_response_header(req, "Access-Control-Allow-Origin", "*");
			http_response(req, 200, result_string, strlen(result_string));
			return KORE_RESULT_OK;
		}
		cJSON_Delete(time_json);
		result_string = "Error: could not get time from /dev/rtc\n";
		http_response(req, 500, result_string, strlen(result_string));
		return KORE_RESULT_OK;
	} else if (req->method == HTTP_METHOD_POST) {
		char * body;
		body = read_body(req);
		if (body == NULL) {
			result_string = "Error: could not read request body\n";
			http_response(req, 500, result_string, strlen(result_string));
			return (KORE_RESULT_OK);
		}
		time_json = cJSON_Parse(body);
		if (time_json == NULL) {
			result_string = "Error: could not parse json\n";
			http_response(req, 500, result_string, strlen(result_string));
			return (KORE_RESULT_OK);
		}
		json_sec = cJSON_GetObjectItemCaseSensitive(time_json, "seconds");
		json_min = cJSON_GetObjectItemCaseSensitive(time_json, "minutes");
		json_hour = cJSON_GetObjectItemCaseSensitive(time_json, "hour");
		json_mday = cJSON_GetObjectItemCaseSensitive(time_json, "mday");
		json_mon = cJSON_GetObjectItemCaseSensitive(time_json, "month");
		json_year = cJSON_GetObjectItemCaseSensitive(time_json, "year");
		json_wday = cJSON_GetObjectItemCaseSensitive(time_json, "wday");
		if (cJSON_IsNumber(json_sec) && cJSON_IsNumber(json_min) && cJSON_IsNumber(json_hour) && 
			cJSON_IsNumber(json_mday) && cJSON_IsNumber(json_mon) && 
			cJSON_IsNumber(json_year) && cJSON_IsNumber(json_wday)) {
			time.tm_sec = json_sec->valueint;
			time.tm_min = json_min->valueint;
			time.tm_hour = json_hour->valueint;
			time.tm_mday = json_mday->valueint;
			time.tm_mon = json_mon->valueint;
			time.tm_year = json_year->valueint;
			time.tm_wday = json_wday->valueint;
		} else {
			cJSON_Delete(time_json);
			result_string = "Error: invalid or missing values in json object\n";
			http_response(req, 500, result_string, strlen(result_string));
                        return (KORE_RESULT_OK);
		}
		cJSON_Delete(time_json);
		fdesc = open("/dev/rtc", O_WRONLY);
		ret = ioctl(fdesc, RTC_SET_TIME, &time);
		close(fdesc);
		if (ret) {
			result_string = "Error: Could not set time via /dev/rtc\n";
			http_response(req, 500, result_string, strlen(result_string));
                        return (KORE_RESULT_OK);
		}
                http_response(req, 200, NULL, 0);
                return KORE_RESULT_OK;
	} else {
		http_response(req, HTTP_STATUS_METHOD_NOT_ALLOWED, NULL, 0);
		return (KORE_RESULT_OK);
	}
}

int handle_wkalrm(struct http_request *req) {
	char *result_string;
	struct rtc_wkalrm alarm;
	int fdesc, ret;
	unsigned char alarm_bit;
	cJSON *alarm_json, *json_min, *json_hour, *json_mday,
                *json_mon, *json_year, *json_sec, *json_wday,
		*json_enabled, *json_pending;
	if(req->method == HTTP_METHOD_GET) {
		alarm_json = cJSON_CreateObject();
		fdesc = open("/dev/rtc", O_RDONLY);
		ret = ioctl(fdesc, RTC_WKALM_RD, &alarm);
		ret |= ioctl(fdesc, IOCTL_DS13307_ALRM, &alarm_bit);
		close(fdesc);
		if (!ret) {
			json_sec = cJSON_CreateNumber(alarm.time.tm_sec);
                        json_min = cJSON_CreateNumber(alarm.time.tm_min);
                        json_hour = cJSON_CreateNumber(alarm.time.tm_hour);
                        json_mday = cJSON_CreateNumber(alarm.time.tm_mday);
                        json_mon = cJSON_CreateNumber(alarm.time.tm_mon);
                        json_year = cJSON_CreateNumber(alarm.time.tm_year);
                        json_wday = cJSON_CreateNumber(alarm.time.tm_wday);
			json_enabled = cJSON_CreateNumber(alarm.enabled);
			json_pending = cJSON_CreateNumber(alarm_bit);
			cJSON_AddItemToObject(alarm_json, "seconds", json_sec);
                        cJSON_AddItemToObject(alarm_json, "minutes", json_min);
                        cJSON_AddItemToObject(alarm_json, "hour", json_hour);
                        cJSON_AddItemToObject(alarm_json, "mday", json_mday);
                        cJSON_AddItemToObject(alarm_json, "month", json_mon);
                        cJSON_AddItemToObject(alarm_json, "year", json_year);
                        cJSON_AddItemToObject(alarm_json, "wday", json_wday);
			cJSON_AddItemToObject(alarm_json, "enabled", json_enabled);
			cJSON_AddItemToObject(alarm_json, "pending", json_pending);
			result_string = cJSON_Print(alarm_json);
			cJSON_Delete(alarm_json);
                        http_response_header(req, "Content-Type", "application/json");
                        http_response_header(req, "Access-Control-Allow-Origin", "*");
                        http_response(req, 200, result_string, strlen(result_string));
                        return KORE_RESULT_OK;
		} 
		cJSON_Delete(alarm_json);
                result_string = "Error: could not get alarm from /dev/rtc\n";
                http_response(req, 500, result_string, strlen(result_string));
                return KORE_RESULT_OK;
	} else if (req->method == HTTP_METHOD_POST) {
		char * body = read_body(req);
		if (body == NULL) {
			result_string = "Error: could not read request body\n";
			http_response(req, 500, result_string, strlen(result_string));
			return (KORE_RESULT_OK);
                }
		alarm_json = cJSON_Parse(body);
		if (alarm_json == NULL) {
                        result_string = "Error: could not parse json\n";
                        http_response(req, 500, result_string, strlen(result_string));
                        return (KORE_RESULT_OK);
                }
		json_sec = cJSON_GetObjectItemCaseSensitive(alarm_json, "seconds");
                json_min = cJSON_GetObjectItemCaseSensitive(alarm_json, "minutes");
                json_hour = cJSON_GetObjectItemCaseSensitive(alarm_json, "hour");
                json_mday = cJSON_GetObjectItemCaseSensitive(alarm_json, "mday");
                json_mon = cJSON_GetObjectItemCaseSensitive(alarm_json, "month");
                json_year = cJSON_GetObjectItemCaseSensitive(alarm_json, "year");
                json_wday = cJSON_GetObjectItemCaseSensitive(alarm_json, "wday");
		json_enabled = cJSON_GetObjectItemCaseSensitive(alarm_json, "enabled");
		if (cJSON_IsNumber(json_sec) && cJSON_IsNumber(json_min) && cJSON_IsNumber(json_hour) &&
                        cJSON_IsNumber(json_mday) && cJSON_IsNumber(json_mon) &&
                        cJSON_IsNumber(json_year) && cJSON_IsNumber(json_wday) &&
			cJSON_IsNumber(json_enabled)) {
                        alarm.time.tm_sec = json_sec->valueint;
                        alarm.time.tm_min = json_min->valueint;
                        alarm.time.tm_hour = json_hour->valueint;
                        alarm.time.tm_mday = json_mday->valueint;
                        alarm.time.tm_mon = json_mon->valueint;
                        alarm.time.tm_year = json_year->valueint;
                        alarm.time.tm_wday = json_wday->valueint;
			alarm.enabled = json_enabled->valueint;
                } else {
                        cJSON_Delete(alarm_json);
                        result_string = "Error: invalid or missing values in json object\n";
                        http_response(req, 500, result_string, strlen(result_string));
                        return (KORE_RESULT_OK);
                }
		cJSON_Delete(alarm_json);
                fdesc = open("/dev/rtc", O_WRONLY);
                ret = ioctl(fdesc, RTC_WKALM_SET, &alarm);
                close(fdesc);
                if (ret) {
                        result_string = "Error: Could not set alarm via /dev/rtc\n";
                        http_response(req, 500, result_string, strlen(result_string));
                        return (KORE_RESULT_OK);
                }
                http_response(req, 200, NULL, 0);
                return KORE_RESULT_OK;
	} else {
                http_response(req, HTTP_STATUS_METHOD_NOT_ALLOWED, NULL, 0);
                return (KORE_RESULT_OK);
	}
}

int detect_device(struct http_request *req) {
	if(req->method == HTTP_METHOD_GET) {
		if (access("/sys/bus/nvmem/devices/ds1307_nvram0/nvmem", F_OK) != -1) {
			http_response(req, 200, "DS1307", 6);
		} else {
			http_response(req, 200, "DS1337", 6);
		}
		return KORE_RESULT_OK;
	} else {
		http_response(req, HTTP_STATUS_METHOD_NOT_ALLOWED, NULL, 0);
                return (KORE_RESULT_OK);
	}
}

int handle_nvmem(struct http_request *req) {
	int fdesc, bytes_read;
	unsigned char buf[56];
	char r_string[113];
	char buf2[3];
	char * result_object;
	char * result_string;
	cJSON *json_response, *json_string;
	if(req->method == HTTP_METHOD_GET) {
		fdesc = open("/sys/bus/nvmem/devices/ds1307_nvram0/nvmem", O_RDONLY);
		bytes_read = read(fdesc, &buf, 56);
		close(fdesc);
		if(bytes_read == 56) {
			r_string[112] = '\0';
			for(int i=0; i<56; i++) {
				if (buf[i] <= 15) {
					sprintf(buf2, "0%x", buf[i]);
				} else {
					sprintf(buf2, "%x", buf[i]);
				}
				strcpy(r_string + i*2, buf2);
			}
			json_response = cJSON_CreateObject();
			json_string = cJSON_CreateString(r_string);
			cJSON_AddItemToObject(json_response, "content", json_string);	
			result_object = cJSON_Print(json_response);
                        cJSON_Delete(json_response);
                        http_response_header(req, "Content-Type", "application/json");
                        http_response_header(req, "Access-Control-Allow-Origin", "*");
			http_response(req, 200, result_object, strlen(result_object));
		} else {
                        result_string = "Error: could not read from nvmem\n";
                        http_response(req, 500, result_string, strlen(result_string));
                }
		return KORE_RESULT_OK;
	} else if (req->method == HTTP_METHOD_POST) {
		unsigned char to_write[56];
		int buf3 = 0;
		int bytes_written;
		cJSON *body_json, *input_json;
		char * input_string;
		char * body = read_body(req);
		if (body == NULL) {
                        result_string = "Error: could not read request body\n";
                        http_response(req, 500, result_string, strlen(result_string));
                        return (KORE_RESULT_OK);
                }
		body_json = cJSON_Parse(body);
		input_json = cJSON_GetObjectItemCaseSensitive(body_json, "content");
		if (cJSON_IsString(input_json)) {
			input_string = input_json->valuestring;	
		} else {
			result_string = "Error: invalid value in json content\n";
                        http_response(req, 500, result_string, strlen(result_string));
                        return (KORE_RESULT_OK);
		}
		for (int i=0; i<112; i++) {
			if(i%2 == 0) {
				buf3 = 0;
			} else {
				buf3 = buf3 <<4;
			}
			if((input_string[i] >= '0') && (input_string[i] <= '9')) {
				buf3 += input_string[i] - '0';
			} else if ((input_string[i] >= 'A') && (input_string[i] <= 'Z')) {
				buf3 += input_string[i] - 55;
			}
			if (i%2 != 0) {
				to_write[i/2] = (unsigned char) buf3;
			}
		}
		cJSON_Delete(body_json);
		fdesc = open("/sys/bus/nvmem/devices/ds1307_nvram0/nvmem", O_WRONLY);
		bytes_written = write(fdesc, to_write, 56);
		close(fdesc);
		if (bytes_written == 56) {
			http_response(req, 200, NULL, 0);
                        return (KORE_RESULT_OK);
		}
		result_string = "Error: could not write to nvmem\n";
		http_response(req, 500, result_string, strlen(result_string));
		return (KORE_RESULT_OK);
	} else {
                http_response(req, HTTP_STATUS_METHOD_NOT_ALLOWED, NULL, 0);
                return (KORE_RESULT_OK);
        }
}