/* $Id: plugin_pop3.c,v 1.6 2004/06/26 12:05:00 reinelt Exp $
 *
 * Plugin to check POP3 mail accounts
 *
 * Copyright 2004 Javi Garcia Dominguez (aka Stolz) <javi@gsmlandia.com>
 * Based on code from  pop3check (c) 1999 http://sourceforge.net/projects/pop3check
 *     Simon Liddington <squidly@users.sourceforge.net> is the pop3check current maintainer.
 *     The pop3check original author is Steven Radack <steve@lconn.net>.
 *
 * Copyright 2004 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
 *
 * This file is a pluging for LCD4Linux.
 *
 * LCD4Linux 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; either version 2, or (at your option)
 * any later version.
 *
 * LCD4Linux 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, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 * $Log: plugin_pop3.c,v $
 * Revision 1.6  2004/06/26 12:05:00  reinelt
 *
 * uh-oh... the last CVS log message messed up things a lot...
 *
 * Revision 1.5  2004/06/26 09:27:21  reinelt
 *
 * added '-W' to CFLAGS
 * changed all C++ comments to C ones
 * cleaned up a lot of signed/unsigned mistakes
 *
 * Revision 1.4  2004/05/31 21:05:13  reinelt
 *
 * fixed lots of bugs in the Cwlinux driver
 * do not emit EAGAIN error on the first retry
 * made plugin_i2c_sensors a bit less 'chatty'
 * moved init and exit functions to the bottom of plugin_pop3
 *
 * Revision 1.3  2004/05/20 07:14:46  reinelt
 * made all local functions static
 *
 * Revision 1.2  2004/04/17 13:03:34  nicowallmeier
 * minor bugfix
 *
 * Revision 1.1  2004/04/08 11:59:26  reinelt
 * added plugin_pop3 from Javi
 *
 */


#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "debug.h"
#include "plugin.h"
#include "cfg.h"

/*added */
#include <sys/socket.h>
#include <sys/types.h>
/*#include <netinet/in.h> */
#include <netdb.h>
#include <unistd.h>
/*#include <pwd.h> */
#include <stdio.h>

#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif

   /*POP 3 */
#define POPERR			"-ERR"
#define LOCKEDERR		"-ERR account is locked by another session or for maintenance, try again."
#define BUFSIZE	8192
#define POP3PORT	110
#define MAX_NUM_ACCOUNTS	3


struct check {
	int	id;
	char	*username;
	char	*password;
	char	*server;
	int	port;
	int	messages;
	struct check *next;
};

/************************ PROTOTYPES  ********************************/
/* list */
static struct check *check_node_alloc(void);
static void check_node_add(struct check **head, struct check *new_check);
static void check_destroy(struct check **head);
/* pop3 */
static void pop3_check_messages(struct check *hi,int verbose);
static void pop3_recv_crlf_terminated(int sockfd, char *buf, int size);
/* socket  */
static int tcp_connect(struct check *hi);
/************************ GLOBAL ***********************************/
static char Section[] = "Plugin:POP3";
static struct check	*head = NULL;
/********************************************************************/
static void my_POP3check (RESULT *result, RESULT *check)
{
	double value;
	double param=R2N(check);
	
	struct check *node = NULL;

	for (node = head; node; node = node->next)
	{
		if (node->id == param)
			break;
	}
	if (node == NULL) /*Inexistent account */
		value=-1.0;
	else
		pop3_check_messages(node,0);
	value = (double)node->messages;
	SetResult(&result, R_NUMBER, &value); 
}

static int getConfig (void)
{
	struct check	*node = NULL;
	int i,n=0;
	char	*user= (char *)calloc(1, sizeof("user")+sizeof(int));
	char	*password= (char *)calloc(1, sizeof("password")+sizeof(int));
	char	*server=(char *)calloc(1, sizeof("server")+sizeof(int));
	char *port= (char *)calloc(1, sizeof("port")+sizeof(int));
	
 	for (i =1;i <= MAX_NUM_ACCOUNTS; i++)
	{
		char *x;
		sprintf(user,"user%d",i);
		sprintf(password,"password%d",i);
		sprintf(server,"server%d",i);
		sprintf(port,"port%d",i);
	
		x = cfg_get (Section, server, "");
		if (*x=='\0') 
		{
			info ("[POP3] No '%s.%s' entry from %s, disabling POP3 account #%d", Section, server, cfg_source(),i);
			free(x);
		}
		else
		{   
			node = check_node_alloc();
			node->id = i;
			node->server = x;
			node->messages = 0;
			node->next = NULL;
			
			x = cfg_get (Section, user, "");
			if (*x=='\0') 
			{
				info ("[POP3] No '%s.%s' entry from %s, disabling POP3 account #%d", Section, user, cfg_source(),i);
				free(x);
			}
			else
			{   
				node->username = x;
				x = cfg_get (Section, password, "");
				if (*x=='\0')
				{
					info ("[POP3] No '%s.%s' entry from %s, disabling POP3 account #%d", Section, password, cfg_source(),i);
					free(x);
				}
				else
				{
					node->password = x;
 					if (cfg_number(Section, port, POP3PORT, 1, 65536, &node->port)<1) 
 						info("[POP3] No '%s.%s' entry from %s, %d will be used for account #%d", Section, port, cfg_source(),POP3PORT,i);
					check_node_add(&head, node);
					n++;
				}
			}
		}
 	}
	return(n);
}

/************************ LIST  ***********************************/
static struct check *check_node_alloc(void)
{
	struct check *new_check;
	new_check = (struct check *)calloc(1, sizeof(struct check));
	if (new_check == NULL)
	{
		error( "[POP3] out of memory\n");
	}
	return new_check;
}

static void check_node_add(struct check **head, struct check *new_check)
{
	new_check->next = *head ;
	*head = new_check;
}

static void check_destroy(struct check **head)
{	
	struct check *iter;
	while (*head)
	{
		iter = (*head)->next;
		free((*head)->username);
		free((*head)->password);
		free((*head)->server);
		free(*head);
		*head = iter;
	}
	*head = NULL;
}

/************************ POP3  ********************************/
static void pop3_check_messages(struct check *hi,int verbose)
{
	char				buf[BUFSIZE];
	int					sockfd;

	if ((sockfd = tcp_connect(hi)) < 0)
	{
		hi->messages = -1;
		return;
	}
	
	pop3_recv_crlf_terminated(sockfd, buf, sizeof(buf)); /* server greeting */
	if (verbose)
		info("[POP3] %s -> %s\n", hi->server, buf);

	snprintf(buf, sizeof(buf), "USER %s\r\n", hi->username);
	write(sockfd, buf, strlen(buf));
	buf[strlen(buf)-1] = '\0';
	if (verbose)
		info("[POP3] %s <- %s\n", hi->server, buf);
	pop3_recv_crlf_terminated(sockfd, buf, sizeof(buf)); /* response from USER command */
	if (verbose)
		info("[POP3] %s -> %s\n", hi->server, buf);

	snprintf(buf, sizeof(buf), "PASS %s\r\n", hi->password);
	write(sockfd, buf, strlen(buf));
	if (verbose)
		info("[POP3] %s <- PASS ???\n", hi->server);
	pop3_recv_crlf_terminated(sockfd, buf, sizeof(buf)); /* response from PASS command */
	if (verbose)
		info("[POP3] %s -> %s\n", hi->server, buf);

	if (strncmp(buf, LOCKEDERR, strlen(LOCKEDERR)) == 0)
	{
		hi->messages = -2;
		close(sockfd);
		return;
	}
	if (strncmp(buf, POPERR, strlen(POPERR)) == 0)
	{
		error("[POP3] error logging into %s\n", hi->server);
		error("[POP3] server responded: %s\n", buf);
		hi->messages = -1;
		close(sockfd);
		return;
	}
	
	snprintf(buf, sizeof(buf), "STAT\r\n");
	write(sockfd, buf, strlen(buf));
	if (verbose)
		info("[POP3] %s <- STAT\n", hi->server);
	pop3_recv_crlf_terminated(sockfd, buf, sizeof(buf)); /* response from PASS command */
	if (verbose)
		info("[POP3] %s -> %s\n", hi->server, buf);

	strtok(buf, " ");
	hi->messages =  atoi(strtok(NULL, " "));

	snprintf(buf, sizeof(buf), "QUIT\r\n");
	write(sockfd, buf, strlen(buf));
	if (verbose)
		info("[POP3] %s <- QUIT\n", hi->server);
	pop3_recv_crlf_terminated(sockfd, buf, sizeof(buf)); /* response from QUIT command */
	if (verbose)
		info("[POP3] %s -> %s\n", hi->server, buf);
	
	close(sockfd);
}

static void pop3_recv_crlf_terminated(int sockfd, char *buf, int size)
{
/* receive one line server responses terminated with CRLF */
	char			*pos;
	int				bytes = 0;
	memset(buf, 0, size);
	while ((pos = strstr(buf, "\r\n")) == NULL)
		bytes += read(sockfd, buf+bytes, size-bytes);
	*pos = '\0';
}

/************************ SOCKET  ********************************/
static int tcp_connect(struct check *hi)
{
	struct sockaddr_in		addr;
	struct hostent			*he = gethostbyname(hi->server);
	int						sockfd;

	if (hi == NULL)
		return -1;	

	if (!he)
	{
		error("[POP3] Failed to lookup %s\n",hi->server);
		return(-1);
	}

	memset((char *)&addr, 0, sizeof(struct sockaddr_in));
	addr.sin_family = AF_INET;
	memcpy(&(addr.sin_addr.s_addr), he->h_addr, he->h_length);
	addr.sin_port = htons(hi->port);

	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	{
		perror("socket()");
		return(-1);
	}
	
	if (connect(sockfd, (struct sockaddr *)&addr, sizeof(struct sockaddr)) < 0)
	{
		perror("connect()");
		close(sockfd);
		return(-1);
	}

	return(sockfd);
}


int plugin_init_pop3(void)
{
	
	int n = getConfig();
	/* by now, head should point to a list of all our accounts */
	if (head)
	{
		info("[POP3] %d POP3 accounts have been succesfully defined",n);
		AddFunction ("POP3check",  1, my_POP3check);
	}
	return 0;
}

void plugin_exit_pop3(void) 
{
	check_destroy(&head);
}