hare / hared

hare.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <memory.h>
#include <sys/socket.h>

/*
 * hare.c (C)2018 by Jan-Piet Mens <jp@mens.de>
 */

#define PORTNO  8035

#define env(K)	( getenv(K) ? getenv(K) : "<unknown>" )

int main(int argc, char **argv)
{
	struct sockaddr_in servaddr;
	unsigned long addr;
	int sockfd;
	char *host = argv[1], buf[BUFSIZ], myhostname[BUFSIZ];
	char *pamtype = env("PAM_TYPE");	/* Linux */
	char *pamsm = env("PAM_SM_FUNC");	/* FreeBSD https://www.freebsd.org/cgi/man.cgi?query=pam_exec */

	if (strcmp(pamtype, "open_session") != 0 && strcmp(pamsm, "pam_sm_open_session") != 0) {
		fprintf(stderr, "Neither PAM open_session nor pam_sm_open_session detected\n");
		return 0;
	}

	if (argc != 2) {
		fprintf(stderr, "Usage: %s address\n", *argv);
		exit(2);
	}

	if (gethostname(myhostname, sizeof(myhostname)) != 0)
		strcpy(myhostname, "?");

	snprintf(buf, sizeof(buf), "%s login to %s from %s via %s",
		env("PAM_USER"),
		myhostname,
		env("PAM_RHOST"),
		env("PAM_SERVICE"));

	addr = inet_addr(host);

	memset(&servaddr, 0, sizeof(servaddr));
	servaddr.sin_family = AF_INET;
	servaddr.sin_port = htons(PORTNO);
	memcpy((void *)&servaddr.sin_addr, (void *)&addr, sizeof(addr));

	sockfd = socket(AF_INET, SOCK_DGRAM, 0);

	if (sendto(sockfd, (void *)buf, strlen(buf), 0, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0) {
		perror("sendto");
	}
	return (0);
}

hared.go

package main

import (
    "fmt"
    "net"
    "encoding/json"
    "github.com/eclipse/paho.mqtt.golang"
)

type Data struct {
    Host string `json:"host"`
    Msg string  `json:"msg"`
}

func main() {
    ServerAddr, _ := net.ResolveUDPAddr("udp",":8035")
    ServerConn, _ := net.ListenUDP("udp", ServerAddr)
    defer ServerConn.Close()

    buf := make([]byte, 1024)

    for {
        n,addr,_ := ServerConn.ReadFromUDP(buf)

        message := string(buf[0:n]);
        address := addr.IP.String();

        data := Data{Host: address, Msg: message}

        js, _ := json.Marshal(data)
        fmt.Println(string(js))

        opts := mqtt.NewClientOptions().AddBroker("tcp://192.168.1.130:1883")
        c := mqtt.NewClient(opts)
        if token := c.Connect(); token.Wait() && token.Error() != nil {
                    fmt.Println(token.Error())
        }
        if token := c.Publish("logging/hare", 0, false, js); token.Wait() && token.Error() != nil {
                    fmt.Println(token.Error())
        }
    }
}

hared.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import paho.mqtt.publish as mqtt
import socket
import json

__author__    = 'Jan-Piet Mens <jp()mens.de>'

server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server_socket.bind(('', 8035))

while True:
    message, address = server_socket.recvfrom(1024)
    host, port = address

    data = {
        'host' : host,
        'msg'  : message,
    }

    js = json.dumps(data)
    print js

    mqtt.single("logging/hare", js, hostname='192.168.1.130')