/* Libsmtp - (C)opyright 2000-2001 Kristian Van Der Vliet

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA */

#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include <unistd.h>
#include <signal.h>

#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netdb.h>

#include <platon/net/smtp/smtp.h>

#ifdef __SMTP_DEBUG
#  include <stdio.h>
#endif	/* __SMTP_DEBUG */

/* Socket *has* to be a global */
int __smtpGlobalSocket;

/* Timeout must also be global */
unsigned long __smtpTimeout  = 30;
unsigned char __smtpTimedOut = 0;	/* 0==FALSE 1==TRUE */

#define __SMTP_ALARM_SET \
	signal(SIGALRM, smtp_alarm); \
	(void) alarm(__smtpTimeout);
#define __SMTP_ALARM_CLEAR \
	signal(SIGALRM, SIG_DFL); \
	(void) alarm(0);

int smtp_clear_buf(int nSocket);
void smtp_alarm(int unused);

int smtp_connect(const char* zServer, int nPort)
{
	struct sockaddr_in sSocketAddr;	/* Socket connection details */
	struct hostent* sServer;			/* Host details */

	char nRecvBuf[3];					/* Receive buffer */
	int nBytesRecv,nBytesSend;		/* Number of bytes read by recv &
									   send*/

	char zHostName[255];				/* Hostname of this computer */
	char* nHeloMsg;					/* Message sent when we HELO
									   with the server */

#ifdef __SMTP_DEBUG
	printf("libsmtp: smtp_connect: Server is \"%s\", port %i\n",
			zServer,nPort);
#endif /* __SMTP_DEBUG */

	/* Lookup the hostname of the server */

	sServer=gethostbyname(zServer);
	if(sServer==NULL)
		return(-SMTP_UNKNOWN_SERVER);

#ifdef __SMTP_DEBUG
	printf("libsmtp: smtp_connect: IP address %s\n",
			inet_ntoa(*((struct in_addr *)sServer->h_addr)));
#endif /* __SMTP_DEBUG */

	/* Now attempt to open a socket to the server */
	__smtpGlobalSocket=socket(PF_INET,SOCK_STREAM,0);

	sSocketAddr.sin_family=AF_INET;
	sSocketAddr.sin_port=htons(nPort);

	/* FIXME:  Don't even ask.  The code is ugly.  It does it ass	*/
	/* backwards.  It sucks.  But it works.  Want to fix it?		*/
	/* Please do :)													*/

	if(inet_aton( inet_ntoa(*((struct in_addr *)sServer->h_addr)),
				&(sSocketAddr.sin_addr))==0)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_connect: Connect failed at inet_ntoa()\n");
#endif	/* __SMTP_DEBUG */
		return(-SMTP_CONNECT_FAILED);
	}

	memset(&(sSocketAddr.sin_zero),'\0',8);

	/* Set the timeout alarm */
	__SMTP_ALARM_SET

		if(connect(__smtpGlobalSocket, (struct sockaddr*)&sSocketAddr,
					sizeof(struct sockaddr))==-1)
		{
#ifdef __SMTP_DEBUG
			printf("libsmtp: smtp_connect: Connect failed at connect()\n");
#endif	/* __SMTP_DEBUG */
			return(-SMTP_CONNECT_FAILED);
		}

	/* Clear the timeout alarm & see if we timedout */
	__SMTP_ALARM_CLEAR
		if(__smtpTimedOut==1)
			return(-SMTP_TIMED_OUT);

#ifdef __SMTP_DEBUG
	printf("libsmtp: smtp_connect: Connected\n");
#endif	/* __SMTP_DEBUG */

	/* We should now have a socket connection to the server,
	   on the requested port
	   The SMTP server should send a 220 Service Ready response */

	nBytesRecv=recv(__smtpGlobalSocket,(void*)&nRecvBuf,3,0);
	if(nBytesRecv<3)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_connect: Server did not respond correctly!\n");
#endif	/* __SMTP_DEBUG */
		return(-SMTP_CONNECT_FAILED);
	}

	nRecvBuf[3]='\0';		/* Terminate after the first 3 bytes, which
							   will be just the return code, as we use strcmp on the buffer */

	if(strcmp(nRecvBuf,"220")!=0)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_connect: Server responded %s\n",
				nRecvBuf);
#endif	/* __SMTP_DEBUG */
		return(-SMTP_CONNECT_FAILED);
	}

	/* Clear out the rest of the buffer */

	smtp_clear_buf(__smtpGlobalSocket);

	/* Create our "HELO" message */
	gethostname(zHostName, sizeof(zHostName));

	nHeloMsg=(char*)malloc(8+strlen(zHostName));
	nHeloMsg=(char*)memset(nHeloMsg,'\0',8+strlen(zHostName));

	nHeloMsg=strcpy(nHeloMsg,"HELO ");
	nHeloMsg=strcat(nHeloMsg,zHostName);
	nHeloMsg=strcat(nHeloMsg,"\r\n\0");

#ifdef __SMTP_DEBUG
	printf("libsmtp: smtp_connectt: HELO message is %s\n",nHeloMsg);
#endif	/* __SMTP_DEBUG */

	/* Now send the HELO line & wait for the response */

#ifdef __SMTP_DEBUG
	printf("libsmtp: smtp_connect: Sending HELO\n");
#endif	/* __SMTP_DEBUG */

	nBytesSend=send(__smtpGlobalSocket,nHeloMsg,strlen(nHeloMsg),0);

	if(nBytesSend!=strlen(nHeloMsg))
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_connect: Didn't send entire HELO\n");
#endif	/* __SMTP_DEBUG */

	/* Get server response, which should be 250 if we're good to go */
	/* Set the timeout alarm */
	__SMTP_ALARM_SET

		nBytesRecv=recv(__smtpGlobalSocket,(void*)&nRecvBuf,3,0);
	if(nBytesRecv<3)
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_connect: Recieved less than 3 bytes\n");
#endif	/* __SMTP_DEBUG */

	/* Clear the timeout alarm & see if we timedout */
	__SMTP_ALARM_CLEAR
		if(__smtpTimedOut==1)
			return(-SMTP_TIMED_OUT);

	nRecvBuf[3]='\0';		/* Terminate after the first 3 bytes, which
							   will be just the return code, as we use strcmp on the buffer */

	if(strcmp(nRecvBuf,"250")!=0)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_connect: HELO failed\n");
		printf("libsmtp: smtp_connect: Server responded %s\n",
				nRecvBuf);
#endif	/* __SMTP_DEBUG */
		return(-SMTP_CONNECT_FAILED);
	}

	/* The server is ready to recieve email from us */

#ifdef __SMTP_DEBUG
	printf("libsmtp: smtp_connect: Ready to send\n");
#endif	/* __SMTP_DEBUG */

	/* Clear out the rest of the buffer */

	smtp_clear_buf(__smtpGlobalSocket);

	/* The connection is open and the server waiting for us */
	return(SMTP_OK);
}

int smtp_sendmail(const char* zTo, const char* zFrom, const char* zBody)
{
	/* Send the mail zBody FROM: zFrom, TO: zTo */

	int nLength;				/* Used to calculate line
								   lengths etc */
	int nBytesRecv,nBytesSend;	/* Returns from send() & recv() */
	char nRecvBuf[3];			/* Return code recieve buffer
	*/
	char *nFromMsg, *nRcptMsg;	/* Mail from & rcpt to messages */

	/* Build our "MAIL FROM:" line */
	nLength=strlen(zFrom);
	nLength+=14;	/* 14 is the length of the string "MAIL FROM: " + \r\n\0 */

	nFromMsg=(char*)malloc(nLength);

	nFromMsg=strcpy(nFromMsg,"MAIL FROM: ");
	nFromMsg=strcat(nFromMsg,zFrom);
	nFromMsg=strcat(nFromMsg,"\r\n\0");

	/* Send the MAIL FROM: line */
	nBytesSend=send(__smtpGlobalSocket,nFromMsg,strlen(nFromMsg),0);

	/* If we're O.K, server should respond with a 250 */
	/* Set the timeout alarm */
	__SMTP_ALARM_SET

		nBytesRecv=recv(__smtpGlobalSocket,(void*)&nRecvBuf,3,0);
	if(nBytesRecv<3)
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: Recieved less than 3 bytes\n");
#endif	/* __SMTP_DEBUG */

	/* Clear the timeout alarm & see if we timedout */
	__SMTP_ALARM_CLEAR
		if(__smtpTimedOut==1)
			return(-SMTP_TIMED_OUT);

	nRecvBuf[3]='\0';		/* Terminate after the first 3 bytes, which
							   will be just the return code, as we use strcmp on the buffer */

	if(strcmp(nRecvBuf,"250")!=0)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: MAIL FROM: failed\n");
		printf("libsmtp: smtp_sendmail: Server responded %s\n", nRecvBuf);
#endif	/* __SMTP_DEBUG */
		return(-SMTP_INVALID_FROM);
	}

	/* Clear out the rest of the buffer */

	smtp_clear_buf(__smtpGlobalSocket);

	/* Now send the RCPT TO: */
	/* Build our "RCPT TO:" line */
	nLength=strlen(zTo);
	nLength+=12;	/* 12 is the length of the string "RCPT TO: " + \r\n\0 */

	nRcptMsg=(char*)malloc(nLength);

	nRcptMsg=strcpy(nRcptMsg,"RCPT TO: ");
	nRcptMsg=strcat(nRcptMsg,zTo);
	nRcptMsg=strcat(nRcptMsg,"\r\n\0");

	/* Send the RCPT TO: line */
	nBytesSend=send(__smtpGlobalSocket,nRcptMsg,strlen(nRcptMsg),0);

	/* If we're O.K, server should respond with a 250 */

	/* Set the timeout alarm */
	__SMTP_ALARM_SET

		nBytesRecv=recv(__smtpGlobalSocket,(void*)&nRecvBuf,3,0);
	if(nBytesRecv<3)
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: Recieved less than 3 bytes\n");
#endif	/* __SMTP_DEBUG */

	/* Clear the timeout alarm & see if we timedout */
	__SMTP_ALARM_CLEAR
		if(__smtpTimedOut==1)
			return(-SMTP_TIMED_OUT);

	nRecvBuf[3]='\0';		/* Terminate after the first 3 bytes, which
							   will be just the return code, as we use strcmp on the buffer */

	if(strcmp(nRecvBuf,"250")!=0)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: RCPT TO: failed\n");
		printf("libsmtp: smtp_sendmail: Server responded %s\n",
				nRecvBuf);
#endif	/* __SMTP_DEBUG */
		return(-SMTP_INVALID_TO);
	}

	/* Clear out the rest of the buffer */

	smtp_clear_buf(__smtpGlobalSocket);

	/* Now send DATA & the message */
	nBytesSend=send(__smtpGlobalSocket,"DATA\r\n",6,0);

	/* DATA should respond with a 354*/
	/* Set the timeout alarm */
	__SMTP_ALARM_SET

		nBytesRecv=recv(__smtpGlobalSocket,(void*)&nRecvBuf,3,0);
	if(nBytesRecv<3)
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: Recieved less than 3 bytes\n");
#endif	/* __SMTP_DEBUG */

	/* Clear the timeout alarm & see if we timedout */
	__SMTP_ALARM_CLEAR
		if(__smtpTimedOut==1)
			return(-SMTP_TIMED_OUT);

	nRecvBuf[3]='\0';		/* Terminate after the first 3 bytes, which
							   will be just the return code, as we use strcmp on the buffer */

	if(strcmp(nRecvBuf,"354")!=0)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: DATA failed\n");
		printf("libsmtp: smtp_sendmail: Server responded %s\n", nRecvBuf);
#endif	/* __SMTP_DEBUG */
		return(-SMTP_SEND_FAILED);
	}

	/* Clear out the rest of the buffer */

	smtp_clear_buf(__smtpGlobalSocket);

	/* Send the message */
	nBytesSend=send(__smtpGlobalSocket,zBody,strlen(zBody),0);

	if(nBytesSend<strlen(zBody))
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: "
				"Failed to send entire message body\n");
#endif	/* __SMTP_DEBUG */
		return(-SMTP_SEND_FAILED);
	}

	/* Terminate the message with the .CRLF string */
	nBytesSend=send(__smtpGlobalSocket,".\r\n",3,0);

	/* Check the return code to ensure the message was sent O.K */
	/* Set the timeout alarm */
	__SMTP_ALARM_SET

		nBytesRecv=recv(__smtpGlobalSocket,(void*)&nRecvBuf,3,0);
	if(nBytesRecv<3)
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: Recieved less than 3 bytes\n");
#endif	/* __SMTP_DEBUG */

	/* Clear the timeout alarm & see if we timedout */
	__SMTP_ALARM_CLEAR
		if(__smtpTimedOut==1)
			return(-SMTP_TIMED_OUT);

	nRecvBuf[3]='\0';		/* Terminate after the first 3 bytes, which
							   will be just the return code, as we use strcmp on the buffer */

	if(strcmp(nRecvBuf,"250")!=0)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_sendmail: "
				"Send failed after message send completed\n");
		printf("libsmtp: smtp_sendmail: Server responded %s\n",
				nRecvBuf);
#endif	/* __SMTP_DEBUG */
		return(-SMTP_SEND_FAILED);
	}

	/* Clear out the rest of the buffer */

	smtp_clear_buf(__smtpGlobalSocket);

	/* All done, message sent & server ready for the next message */
	return(SMTP_OK);
}

int smtp_disconnect(void)
{
	/* Disconnect politly from the mail server */

	int nBytesRecv,nBytesSend;	/* Returns from send() & recv() */
	char nRecvBuf[3];			/* Return code recieve buffer
	*/

	/* Send the QUIT command */
	nBytesSend=send(__smtpGlobalSocket,"QUIT\r\n",6,0);

	/* Check to make sure we've disconnected O.K */
	/* Set the timeout alarm */
	__SMTP_ALARM_SET

		nBytesRecv=recv(__smtpGlobalSocket,(void*)&nRecvBuf,3,0);
	if(nBytesRecv<3)
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_disconnect: Recieved less than 3 bytes\n");
#endif	/* __SMTP_DEBUG */

	/* Clear the timeout alarm & see if we timedout */
	__SMTP_ALARM_CLEAR
		if(__smtpTimedOut==1)
			return(-SMTP_TIMED_OUT);

	nRecvBuf[3]='\0';		/* Terminate after the first 3 bytes, which
							   will be just the return code, as we use strcmp on the buffer */

	if(strcmp(nRecvBuf,"221")!=0)
	{
#ifdef __SMTP_DEBUG
		printf("libsmtp: smtp_disconnect: QUIT failed\n");
		printf("libsmtp: smtp_disconnect: Server responded %s\n",
				nRecvBuf);
#endif	/* __SMTP_DEBUG */
		return(-SMTP_DISCONNECT_FAILED);
	}

	/* Clear out the rest of the buffer */

	smtp_clear_buf(__smtpGlobalSocket);

	/* Close the socket! */

	close(__smtpGlobalSocket);

	/* Done */
	return(SMTP_OK);
}

int smtp_set_timeout(unsigned long nTimeout)
	/* Set the new server timeout value */
{
	__smtpTimeout=nTimeout;
	return(SMTP_OK);
}

int smtp_clear_buf(int nSocket)
	/* Read through the buffer one byte at a time until we hit a CRLF */
{
	char nBufByte;

	/* Set the timeout alarm */
	__SMTP_ALARM_SET

		while(recv(nSocket,(void*)&nBufByte,1,0)>0)
		{
			if(nBufByte=='\r')
				/* Chomp the \n */
			{
				recv(nSocket,(void*)&nBufByte,1,0);

				__SMTP_ALARM_CLEAR
					if(__smtpTimedOut==1)	/* See if we timed out */
						break;

				return(SMTP_OK);
			}
		}

	return(-1);
}

void smtp_alarm(int unused)
	/* Callback function for alarm() */
{
#ifdef __SMTP_DEBUG
	printf("libsmtp: smtp_alarm: Timed out!\n");
#endif

	__smtpTimedOut=1;
	return;
}

#if defined(SELF) || defined(SELFTEST) || defined(SELF_SMTP)

#include <stdio.h>

int main(int argc, char **argv)
{
	register int port = SMTP_PORT;
	char *server = "localhost";

	char message[] =
		"From: frodo@bagend.com\r\n"
		"To: fred@foo.com, jane@baz.org\r\n"
		"Subject: Libsmtp example\r\n\r\n"
		"This is a message to show libsmtp in action\r\n";

	if (argc < 2) {
		fprintf(stderr, "Usage: %s <RCPT_TO_address>"
				" [ <smpt_server> [ <port> ]]\n", argv[0]);
		return 1;
	}
	if (argc > 2) {
		server = argv[2];
	}
	if (argc > 3) {
		port = atoi(argv[3]);
		if (port == 0)
			port = SMTP_PORT;
	}

	/* Obviously you can build your message dynamically.  This message does not
	   include all the headers required by RFC2822, only the bare minimum */

	printf("Connecting to server\n");
	if(smtp_connect(server, port)<0)
	{
		printf("Failed to connect to server!\n");
		return(1);
	}

	printf("Connected\nSending mail\n");

	if (smtp_sendmail(argv[1],
				"user@localhost", message) < 0) {
		printf("Failed to send mail\n");
		/* Attempt to disconnect from the server */
		smtp_disconnect();

		return(1);
	}

	printf("Mail sent successfully\nDisconnecting\n");

	smtp_disconnect();

	printf("All done!\n");

	return(0);
}

#endif