mailsrvr.c

	if(!stricmp(field, "IN-REPLY-TO"))
		return smb_hfield_str(msg, *type=RFC822REPLYID, p);

	if(!stricmp(field, "CC"))
		return smb_hfield_str(msg, *type=SMB_CARBONCOPY, p);

	if(!stricmp(field, "RECEIVED"))
		return smb_hfield_str(msg, *type=SMTPRECEIVED, p);

	if(!stricmp(field, "RETURN-PATH")) {
		*type=UNKNOWN;
		return SMB_SUCCESS;	/* Ignore existing "Return-Path" header fields */
	}

	/* Fall-through */
	return smb_hfield_str(msg, *type=RFC822HEADER, buf);
}

static int chk_received_hdr(SOCKET socket,const char *buf,IN_ADDR *dnsbl_result, char *dnsbl, char *dnsbl_ip)
{
	char		host_name[128];
	IN_ADDR		check_addr;
	char		*fromstr;
	char		ip[16];
	char		*p;
	char		*p2;
	char		*last;

	fromstr=(char *)malloc(strlen(buf)+1);
	if(fromstr==NULL)
		return(0);
	strcpy(fromstr,buf);
	strlwr(fromstr);
	do {
		p=strstr(fromstr,"from ");
		if(p==NULL)
			break;
		p+=4;
		SKIP_WHITESPACE(p);
		if(*p==0)
			break;
		p2=host_name;
		for(;*p && !isspace((unsigned char)*p) && p2<host_name+126;p++)  {
			*p2++=*p;
		}
		*p2=0;
		p=strtok_r(fromstr,"[",&last);
		if(p==NULL)
			break;
		p=strtok_r(NULL,"]",&last);
		if(p==NULL)
			break;
		strncpy(ip,p,16);
		ip[15]=0;
		check_addr.s_addr = inet_addr(ip);
		lprintf(LOG_DEBUG,"%04d SMTP DNSBL checking received header address %s [%s]",socket,host_name,ip);
		if((dnsbl_result->s_addr=dns_blacklisted(socket,check_addr,host_name,dnsbl,dnsbl_ip))!=0)
				lprintf(LOG_NOTICE,"%04d SMTP BLACKLISTED SERVER on %s: %s [%s] = %s"
					,socket, dnsbl, host_name, ip, inet_ntoa(*dnsbl_result));
	} while(0);
	free(fromstr);
	return(dnsbl_result->s_addr);
}

static void parse_mail_address(char* p
							   ,char* name, size_t name_len
							   ,char* addr, size_t addr_len)
{
	char*	tp;
	char	tmp[128];

	SKIP_WHITESPACE(p);

	/* Get the address */
	if((tp=strrchr(p,'<'))!=NULL)
		tp++;
	else
		tp=p;
	SKIP_WHITESPACE(tp);
	sprintf(addr,"%.*s",addr_len,tp);
	truncstr(addr,">( ");

	SAFECOPY(tmp,p);
	p=tmp;
	/* Get the "name" (if possible) */
	if((tp=strchr(p,'('))!=NULL) {			/* name in parenthesis? */
		p=tp+1;
		tp=strchr(p,')');
	} else if((tp=strchr(p,'"'))!=NULL) {	/* name in quotes? */
		p=tp+1;
		tp=strchr(p,'"');
	} else if(*p=='<') {					/* address in brackets? */
		p++;
		tp=strchr(p,'>');
	} else									/* name, then address in brackets */
		tp=strchr(p,'<');
	if(tp) *tp=0;
	sprintf(name,"%.*s",name_len,p);
	truncsp(name);
}

/* Decode quoted-printable content-transfer-encoded text */
/* Ignores (strips) unsupported ctrl chars and non-ASCII chars */
/* Does not enforce 76 char line length limit */
static char* qp_decode(uchar* buf)
{
	uchar*	p=buf;
	uchar*	dest=buf;

	for(;;p++) {
		if(*p==0) {
			*dest++='\r';
			*dest++='\n';
			break;
		}
		if(*p==' ' || (*p>='!' && *p<='~' && *p!='=') || *p=='\t')
			*dest++=*p;
		else if(*p=='=') {
			p++;
			if(*p==0) 	/* soft link break */
				break;
			if(isxdigit(*p) && isxdigit(*(p+1))) {
				char hex[3];
				hex[0]=*p;
				hex[1]=*(p+1);
				hex[2]=0;
				/* ToDo: what about encoded NULs and the like? */
				*dest++=(uchar)strtoul(hex,NULL,16);
				p++;
			} else {	/* bad encoding */
				*dest++='=';
				*dest++=*p;
			}
		}
	}
	*dest=0;
	return buf;
}

static BOOL checktag(scfg_t *scfg, char *tag, uint usernum)
{
	char	fname[MAX_PATH+1];

	if(tag==NULL)
		return(FALSE);
	SAFEPRINTF2(fname,"%suser/%04d.smtpblock",scfg->data_dir,usernum);
	return(findstr(tag, fname));
}

static BOOL smtp_splittag(char *in, char **name, char **tag)
{
	char	*last;

	if(in==NULL)
		return(FALSE);

	*name=strtok_r(in, "#", &last);
	if(*name) {
		*tag=strtok_r(NULL, "", &last);
		return(TRUE);
	}
	return(FALSE);
}

static uint smtp_matchuser(scfg_t *scfg, char *str, BOOL aliases, BOOL datdupe)
{
	char	*user=strdup(str);
	char	*name;
	char	*tag=NULL;
	uint	usernum=0;

	if(!user)
		return(0);

	if(!smtp_splittag(user, &name, &tag))
		goto end;

	if(datdupe)
		usernum=userdatdupe(scfg, 0, U_NAME, LEN_NAME, name, /* del */FALSE, /* next */FALSE);
	else
		usernum=matchuser(scfg, name, aliases);

	if(!usernum)
		goto end;

	if(checktag(scfg, tag, usernum))
		usernum=UINT_MAX;

end:
	free(user);
	return(usernum);
}

static void smtp_thread(void* arg)
{
	int			i,j;
	int			rd;
	char		str[512];
	char		tmp[128];
	char		path[MAX_PATH+1];
	char		value[INI_MAX_VALUE_LEN];
	str_list_t	sec_list;
	char*		section;
	char		buf[1024],*p,*tp,*cp;
	char		hdrfield[512];
	char		alias_buf[128];
	char		name_alias_buf[128];
	char		reverse_path[128];
	char		date[64];
	char		qwkid[32];
	char		rcpt_to[128];
	char		rcpt_name[128];
	char		rcpt_addr[128];
	char		sender[128];
	char		sender_ext[128];
	char		sender_addr[128];
	char		hello_name[128];
	char		user_name[LEN_ALIAS+1];
	char		user_pass[LEN_PASS+1];
	char		relay_list[MAX_PATH+1];
	char		domain_list[MAX_PATH+1];
	char		spam_bait[MAX_PATH+1];
	BOOL		spam_bait_result=FALSE;
	char		spam_block[MAX_PATH+1];
	char		spam_block_exempt[MAX_PATH+1];
	char		host_name[128];
	char		host_ip[64];
	char		dnsbl[256];
	char		dnsbl_ip[64];
	char*		telegram_buf;
	char*		msgbuf;
	char		challenge[256];
	char		response[128];
	char		secret[64];
	char		md5_data[384];
	char		digest[MD5_DIGEST_SIZE];
	char		dest_host[128];
	char*		errmsg;
	ushort		dest_port;
	socklen_t	addr_len;
	ushort		hfield_type;
	ushort		nettype;
	ushort		agent;
	uint		usernum;
	ulong		lines=0;
	ulong		hdr_lines=0;
	ulong		hdr_len=0;
	ulong		length;
	ulong		badcmds=0;
	BOOL		esmtp=FALSE;
	BOOL		telegram=FALSE;
	BOOL		forward=FALSE;
	BOOL		no_forward=FALSE;
	BOOL		auth_login;
	BOOL		routed=FALSE;
	BOOL		dnsbl_recvhdr;
	BOOL		msg_handled;
	uint		subnum=INVALID_SUB;
	FILE*		msgtxt=NULL;
	char		msgtxt_fname[MAX_PATH+1];
	char		newtxt_fname[MAX_PATH+1];
	char		logtxt_fname[MAX_PATH+1];
	FILE*		rcptlst;
	char		rcptlst_fname[MAX_PATH+1];
	ushort		rcpt_count=0;
	FILE*		proc_err;
	char		proc_err_fname[MAX_PATH+1];
	char		session_id[MAX_PATH+1];
	FILE*		spy=NULL;
	SOCKET		socket;
	HOSTENT*	host;
	int			smb_error;
	smb_t		smb;
	smb_t		spam;
	smbmsg_t	msg;
	smbmsg_t	newmsg;
	user_t		user;
	user_t		relay_user;
	node_t		node;
	client_t	client;
	smtp_t		smtp=*(smtp_t*)arg;
	SOCKADDR_IN server_addr;
	IN_ADDR		dnsbl_result;
	BOOL*		mailproc_to_match;
	int			mailproc_match;
	JSRuntime*	js_runtime=NULL;
	JSContext*	js_cx=NULL;
	JSObject*	js_glob=NULL;
	int32		js_result;
	list_node_t*	login_attempt;
	struct mailproc*	mailproc;

	enum {
			 SMTP_STATE_INITIAL
			,SMTP_STATE_HELO
			,SMTP_STATE_MAIL_FROM
			,SMTP_STATE_RCPT_TO
			,SMTP_STATE_DATA_HEADER
			,SMTP_STATE_DATA_BODY

	} state = SMTP_STATE_INITIAL;

	enum {
			 SMTP_CMD_NONE
			,SMTP_CMD_MAIL
			,SMTP_CMD_SEND
			,SMTP_CMD_SOML
			,SMTP_CMD_SAML

	} cmd = SMTP_CMD_NONE;

	enum {
			 ENCODING_NONE
			,ENCODING_BASE64
			,ENCODING_QUOTED_PRINTABLE
	} content_encoding = ENCODING_NONE;

	SetThreadName("SMTP");
	thread_up(TRUE /* setuid */);

	free(arg);

	socket=smtp.socket;

	lprintf(LOG_DEBUG,"%04d SMTP Session thread started", socket);

#ifdef _WIN32
	if(startup->inbound_sound[0] && !(startup->options&MAIL_OPT_MUTE)) 
		PlaySound(startup->inbound_sound, NULL, SND_ASYNC|SND_FILENAME);
#endif

	addr_len=sizeof(server_addr);
	if((i=getsockname(socket, (struct sockaddr *)&server_addr,&addr_len))!=0) {
		lprintf(LOG_CRIT,"%04d !SMTP ERROR %d (%d) getting address/port"
			,socket, i, ERROR_VALUE);
		sockprintf(socket,sys_error);
		mail_close_socket(socket);
		thread_down();
		return;
	} 

	if((mailproc_to_match=alloca(sizeof(BOOL)*mailproc_count))==NULL) {
		lprintf(LOG_CRIT,"%04d !SMTP ERROR allocating memory for mailproc_to_match", socket);
		sockprintf(socket,sys_error);
		mail_close_socket(socket);
		thread_down();
		return;
	} 
	memset(mailproc_to_match,FALSE,sizeof(BOOL)*mailproc_count);

	memset(&smb,0,sizeof(smb));
	memset(&msg,0,sizeof(msg));
	memset(&spam,0,sizeof(spam));
	memset(&user,0,sizeof(user));
	memset(&relay_user,0,sizeof(relay_user));

	SAFECOPY(host_ip,inet_ntoa(smtp.client_addr.sin_addr));

	lprintf(LOG_INFO,"%04d SMTP Connection accepted on port %u from: %s port %u"
		,socket, BE_INT16(server_addr.sin_port), host_ip, ntohs(smtp.client_addr.sin_port));

	if(startup->options&MAIL_OPT_NO_HOST_LOOKUP)
		host=NULL;
	else
		host=gethostbyaddr ((char *)&smtp.client_addr.sin_addr
			,sizeof(smtp.client_addr.sin_addr),AF_INET);

	if(host!=NULL && host->h_name!=NULL)
		SAFECOPY(host_name,host->h_name);
	else
		strcpy(host_name,"<no name>");

	if(!(startup->options&MAIL_OPT_NO_HOST_LOOKUP))
		lprintf(LOG_INFO,"%04d SMTP Hostname: %s", socket, host_name);

	active_clients++, update_clients();

	SAFECOPY(hello_name,host_name);

	SAFEPRINTF(spam_bait,"%sspambait.cfg",scfg.ctrl_dir);
	SAFEPRINTF(spam_block,"%sspamblock.cfg",scfg.ctrl_dir);
	SAFEPRINTF(spam_block_exempt,"%sspamblock_exempt.cfg",scfg.ctrl_dir);

	if(smtp.client_addr.sin_addr.s_addr==server_addr.sin_addr.s_addr 
		|| smtp.client_addr.sin_addr.s_addr==htonl(IPv4_LOCALHOST)) {
		/* local connection */
		dnsbl_result.s_addr=0;
	} else {
		if(trashcan(&scfg,host_ip,"ip") 
			|| (findstr(host_ip,spam_block) && !findstr(host_ip,spam_block_exempt))) {
			lprintf(LOG_NOTICE,"%04d !SMTP CLIENT IP ADDRESS BLOCKED: %s (%u total)"
				,socket, host_ip, ++stats.sessions_refused);
			sockprintf(socket,"550 CLIENT IP ADDRESS BLOCKED: %s", host_ip);
			mail_close_socket(socket);
			thread_down();
			if(active_clients)
				active_clients--, update_clients();
			return;
		}

		if(trashcan(&scfg,host_name,"host") 
			|| (findstr(host_name,spam_block) && !findstr(host_name,spam_block_exempt))) {
			lprintf(LOG_NOTICE,"%04d !SMTP CLIENT HOSTNAME BLOCKED: %s (%u total)"
				,socket, host_name, ++stats.sessions_refused);
			sockprintf(socket,"550 CLIENT HOSTNAME BLOCKED: %s", host_name);
			mail_close_socket(socket);
			thread_down();
			if(active_clients)
				active_clients--, update_clients();
			return;
		}

		/*  SPAM Filters (mail-abuse.org) */
		dnsbl_result.s_addr = dns_blacklisted(socket,smtp.client_addr.sin_addr,host_name,dnsbl,dnsbl_ip);
		if(dnsbl_result.s_addr) {
			lprintf(LOG_NOTICE,"%04d SMTP BLACKLISTED SERVER on %s: %s [%s] = %s"
				,socket, dnsbl, host_name, dnsbl_ip, inet_ntoa(dnsbl_result));
			if(startup->options&MAIL_OPT_DNSBL_REFUSE) {
				SAFEPRINTF2(str,"Listed on %s as %s", dnsbl, inet_ntoa(dnsbl_result));
				spamlog(&scfg, "SMTP", "SESSION REFUSED", str, host_name, dnsbl_ip, NULL, NULL);
				sockprintf(socket
					,"550 Mail from %s refused due to listing at %s"
					,dnsbl_ip, dnsbl);
				mail_close_socket(socket);
				lprintf(LOG_NOTICE,"%04d !SMTP REFUSED SESSION from blacklisted server (%u total)"
					,socket, ++stats.sessions_refused);
				thread_down();
				if(active_clients)
					active_clients--, update_clients();
				return;
			}
		}
	}

	SAFEPRINTF(smb.file,"%smail",scfg.data_dir);
	if(smb_islocked(&smb)) {
		lprintf(LOG_CRIT,"%04d !SMTP MAIL BASE LOCKED: %s"
			,socket, smb.last_error);
		sockprintf(socket,sys_unavail);
		mail_close_socket(socket);
		thread_down();
		if(active_clients)
			active_clients--, update_clients();
		return;
	}
	SAFEPRINTF(spam.file,"%sspam",scfg.data_dir);
	spam.retry_time=scfg.smb_retry_time;
	spam.subnum=INVALID_SUB;

	srand((unsigned int)(time(NULL) ^ (time_t)GetCurrentThreadId()));	/* seed random number generator */
	rand();	/* throw-away first result */
	SAFEPRINTF4(session_id,"%x%x%x%lx",getpid(),socket,rand(),clock());
	lprintf(LOG_DEBUG,"%04d SMTP Session ID=%s", socket, session_id);
	SAFEPRINTF2(msgtxt_fname,"%sSBBS_SMTP.%s.msg", scfg.temp_dir, session_id);
	SAFEPRINTF2(newtxt_fname,"%sSBBS_SMTP.%s.new", scfg.temp_dir, session_id);
	SAFEPRINTF2(logtxt_fname,"%sSBBS_SMTP.%s.log", scfg.temp_dir, session_id);
	SAFEPRINTF2(rcptlst_fname,"%sSBBS_SMTP.%s.lst", scfg.temp_dir, session_id);
	rcptlst=fopen(rcptlst_fname,"w+");
	if(rcptlst==NULL) {
		lprintf(LOG_CRIT,"%04d !SMTP ERROR %d creating recipient list: %s"
			,socket, errno, rcptlst_fname);
		sockprintf(socket,sys_error);
		mail_close_socket(socket);
		thread_down();
		if(active_clients)
			active_clients--, update_clients();
		return;
	}

	if(trashcan(&scfg,host_name,"smtpspy") 
		|| trashcan(&scfg,host_ip,"smtpspy")) {
		SAFEPRINTF(str,"%ssmtpspy.txt", scfg.logs_dir);
		spy=fopen(str,"a");
	}

	/* Initialize client display */
	client.size=sizeof(client);
	client.time=time(NULL);
	SAFECOPY(client.addr,host_ip);
	SAFECOPY(client.host,host_name);
	client.port=ntohs(smtp.client_addr.sin_port);
	client.protocol="SMTP";
	client.user="<unknown>";
	client_on(socket,&client,FALSE /* update */);

	SAFEPRINTF(str,"SMTP: %s",host_ip);
	status(str);

	if(startup->login_attempt_throttle
		&& (login_attempt=loginAttempted(startup->login_attempt_list, &smtp.client_addr)) != NULL
		&& ((login_attempt_t*)login_attempt->data)->count > 1) {
		lprintf(LOG_DEBUG,"%04d SMTP Throttling suspicious connection from: %s", socket, inet_ntoa(smtp.client_addr.sin_addr));
		mswait(((login_attempt_t*)login_attempt->data)->count*startup->login_attempt_throttle);
	}

	/* SMTP session active: */

	sockprintf(socket,"220 %s Synchronet SMTP Server %s-%s Ready"
		,startup->host_name,revision,PLATFORM_DESC);
	while(1) {
		rd = sockreadline(socket, buf, sizeof(buf));
		if(rd<0) 
			break;
		truncsp(buf);
		if(spy!=NULL)
			fprintf(spy,"%s\n",buf);
		if(relay_user.number==0 && dnsbl_result.s_addr && startup->options&MAIL_OPT_DNSBL_THROTTLE)
			mswait(DNSBL_THROTTLE_VALUE);
		if(state>=SMTP_STATE_DATA_HEADER) {
			if(!strcmp(buf,".")) {

				state=SMTP_STATE_HELO;	/* RESET state machine here in case of error */
				cmd=SMTP_CMD_NONE;

				if(msgtxt==NULL) {
					lprintf(LOG_ERR,"%04d !SMTP NO MESSAGE TEXT FILE POINTER?", socket);
					sockprintf(socket,"554 No message text");
					continue;
				}

				if(ftell(msgtxt)<1) {
					lprintf(LOG_ERR,"%04d !SMTP INVALID MESSAGE LENGTH: %ld (%lu lines)"
						, socket, ftell(msgtxt), lines);
					sockprintf(socket,"554 No message text");
					continue;
				}

				lprintf(LOG_INFO,"%04d SMTP End of message (body: %lu lines, %lu bytes, header: %lu lines, %lu bytes)"
					, socket, lines, ftell(msgtxt)-hdr_len, hdr_lines, hdr_len);

				if(!socket_check(socket, NULL, NULL, 0)) {
					lprintf(LOG_ERR,"%04d !SMTP sender disconnected (premature evacuation)", socket);
					continue;
				}

				stats.msgs_received++;

				/* Twit-listing (sender's name and e-mail addresses) here */
				SAFEPRINTF(path,"%stwitlist.cfg",scfg.ctrl_dir);
				if(fexist(path) && (findstr(sender,path) || findstr(sender_addr,path))) {
					lprintf(LOG_NOTICE,"%04d !SMTP FILTERING TWIT-LISTED SENDER: %s <%s> (%u total)"
						,socket, sender, sender_addr, ++stats.msgs_refused);
					SAFEPRINTF2(tmp,"Twit-listed sender: %s <%s>", sender, sender_addr);
					spamlog(&scfg, "SMTP", "REFUSED", tmp, host_name, host_ip, rcpt_addr, reverse_path);
					sockprintf(socket, "554 Sender not allowed.");
					continue;
				}

				if(telegram==TRUE) {		/* Telegram */
					const char* head="\1n\1h\1cInstant Message\1n from \1h\1y";
					const char* tail="\1n:\r\n\1h";
					rewind(msgtxt);
					length=filelength(fileno(msgtxt));
					
					p=strchr(sender_addr,'@');
					if(p==NULL || resolve_ip(p+1)!=smtp.client_addr.sin_addr.s_addr) 
						/* Append real IP and hostname if different */
						safe_snprintf(str,sizeof(str),"%s%s\r\n\1w[\1n%s\1h] (\1n%s\1h)%s"
							,head,sender_addr,host_ip,host_name,tail);
					else
						safe_snprintf(str,sizeof(str),"%s%s%s",head,sender_addr,tail);
					
					if((telegram_buf=(char*)malloc(length+strlen(str)+1))==NULL) {
						lprintf(LOG_CRIT,"%04d !SMTP ERROR allocating %lu bytes of memory for telegram from %s"
							,socket,length+strlen(str)+1,sender_addr);
						sockprintf(socket, insuf_stor);
						continue; 
					}
					strcpy(telegram_buf,str);	/* can't use SAFECOPY here */
					if(fread(telegram_buf+strlen(str),1,length,msgtxt)!=length) {
						lprintf(LOG_ERR,"%04d !SMTP ERROR reading %lu bytes from telegram file"
							,socket,length);
						sockprintf(socket, insuf_stor);
						free(telegram_buf);
						continue; 
					}
					telegram_buf[length+strlen(str)]=0;	/* Need ASCIIZ */

					/* Send telegram to users */
					sec_list=iniReadSectionList(rcptlst,NULL);	/* Each section is a recipient */
					for(rcpt_count=0; sec_list!=NULL
						&& sec_list[rcpt_count]!=NULL 
						&& rcpt_count<startup->max_recipients; rcpt_count++) {

						section=sec_list[rcpt_count];

						SAFECOPY(rcpt_to,iniReadString(rcptlst,section	,smb_hfieldtype(RECIPIENT),"unknown",value));
						usernum=iniReadInteger(rcptlst,section				,smb_hfieldtype(RECIPIENTEXT),0);
						SAFECOPY(rcpt_addr,iniReadString(rcptlst,section	,smb_hfieldtype(RECIPIENTNETADDR),rcpt_to,value));

						if((i=putsmsg(&scfg,usernum,telegram_buf))==0)
							lprintf(LOG_INFO,"%04d SMTP Created telegram (%ld/%u bytes) from %s to %s <%s>"
								,socket, length, strlen(telegram_buf), sender_addr, rcpt_to, rcpt_addr);
						else
							lprintf(LOG_ERR,"%04d !SMTP ERROR %d creating telegram from %s to %s <%s>"
								,socket, i, sender_addr, rcpt_to, rcpt_addr);
					}
					iniFreeStringList(sec_list);
					free(telegram_buf);
					sockprintf(socket,ok_rsp);
					telegram=FALSE;
					continue;
				}

				fclose(msgtxt), msgtxt=NULL;
				fclose(rcptlst), rcptlst=NULL;

				/* External Mail Processing here */
				msg_handled=FALSE;
				if(mailproc_count) {
					SAFEPRINTF2(proc_err_fname,"%sSBBS_SMTP.%s.err", scfg.temp_dir, session_id);
					remove(proc_err_fname);

					for(i=0;i<mailproc_count;i++) {
	
						mailproc=&mailproc_list[i];
						if(mailproc->disabled)
							continue;

						if(!mailproc->process_dnsbl && dnsbl_result.s_addr)
							continue;

						if(!mailproc->process_spam && spam_bait_result)
							continue;

						if(!chk_ar(&scfg,mailproc->ar,&relay_user,&client))
							continue;

						if(mailproc->to!=NULL && !mailproc_to_match[i])
							continue;

						if(mailproc->from!=NULL 
							&& !findstr_in_list(sender_addr, mailproc->from))
							continue;

						if(!mailproc->passthru)
							msg_handled=TRUE;

						mailcmdstr(mailproc->cmdline
							,msgtxt_fname, newtxt_fname, logtxt_fname
							,rcptlst_fname, proc_err_fname
							,host_name, host_ip, relay_user.number
							,rcpt_addr
							,sender, sender_addr, reverse_path, str);
						lprintf(LOG_INFO,"%04d SMTP Executing external mail processor: %s"
							,socket, mailproc->name);

						if(mailproc->native) {
							lprintf(LOG_DEBUG,"%04d SMTP Executing external command: %s"
								,socket, str);
							if((j=system(str))!=0) {
								lprintf(LOG_NOTICE,"%04d SMTP system(%s) returned %d (errno: %d)"
									,socket, str, j, errno);
								if(mailproc->ignore_on_error) {
									lprintf(LOG_WARNING,"%04d !SMTP IGNORED MAIL due to mail processor (%s) error: %d"
										,socket, mailproc->name, j);
									msg_handled=TRUE;
								}
							}
						} else {  /* JavaScript */
							if(!js_mailproc(socket, &client, &relay_user
								,mailproc
								,str /* cmdline */
								,msgtxt_fname, newtxt_fname, logtxt_fname
								,rcpt_addr
								,rcptlst_fname, proc_err_fname
								,sender, sender_addr, reverse_path, hello_name, &js_result
								,&js_runtime, &js_cx, &js_glob
								,"SMTP") || js_result!=0) {
#if 0 /* calling exit() in a script causes js_mailproc to return FALSE */
								lprintf(LOG_NOTICE,"%04d !SMTP JavaScript mailproc command (%s) failed (returned: %d)"
									,socket, str, js_result);
								if(mailproc->ignore_on_error) {
									lprintf(LOG_WARNING,"%04d !SMTP IGNORED MAIL due to mail processor (%s) failure"
										,socket, mailproc->name);
									msg_handled=TRUE;
								}
#endif
							}
						}
						if(flength(proc_err_fname)>0)
							break;
						if(!fexist(msgtxt_fname) || !fexist(rcptlst_fname))
							break;
					}
					if(flength(proc_err_fname)>0 
						&& (proc_err=fopen(proc_err_fname,"r"))!=NULL) {
						while(!feof(proc_err)) {
							int n;
							if(!fgets(str,sizeof(str),proc_err))
								break;
							truncsp(str);
							lprintf(LOG_WARNING,"%04d !SMTP External mail processor (%s) error: %s"
								,socket, mailproc->name, str);
							n=atoi(str);
							if(n>=100 && n<1000)
								sockprintf(socket,"%s", str);
							else
								sockprintf(socket,"554%c%s"
									,ftell(proc_err)<filelength(fileno(proc_err)) ? '-' : ' '
									,str);
						}
						fclose(proc_err);
						msg_handled=TRUE;
					}
					else if(!fexist(msgtxt_fname) || !fexist(rcptlst_fname)) {
						lprintf(LOG_NOTICE,"%04d SMTP External mail processor (%s) removed %s file"
							,socket
							,mailproc->name
							,fexist(msgtxt_fname)==FALSE ? "message text" : "recipient list");
						sockprintf(socket,ok_rsp);
						msg_handled=TRUE;
					}
					else if(msg_handled)
						sockprintf(socket,ok_rsp);
					remove(proc_err_fname);	/* Remove error file here */
				}

				/* Re-open files */
				/* We must do this before continuing for handled msgs */
				/* to prevent freopen(NULL) and orphaned temp files */
				if((rcptlst=fopen(rcptlst_fname,fexist(rcptlst_fname) ? "r":"w+"))==NULL) {
					lprintf(LOG_ERR,"%04d !SMTP ERROR %d re-opening recipient list: %s"
						,socket, errno, rcptlst_fname);
					if(!msg_handled)
						sockprintf(socket,sys_error);
					continue;
				}
			
				if(msg_handled) {
					lprintf(LOG_NOTICE,"%04d SMTP Message handled by external mail processor (%s, %u total)"
						,socket, mailproc->name, ++mailproc->handled);
					continue;
				}

				/* If mailproc has written new message text to .new file, use that instead of .msg */
				if(flength(newtxt_fname) > 0) {
					remove(msgtxt_fname);
					SAFECOPY(msgtxt_fname, newtxt_fname);
				} else
					remove(newtxt_fname);

				if((msgtxt=fopen(msgtxt_fname,"rb"))==NULL) {
					lprintf(LOG_ERR,"%04d !SMTP ERROR %d re-opening message file: %s"
						,socket, errno, msgtxt_fname);
					sockprintf(socket,sys_error);
					continue;
				}

				/* Initialize message header */
				smb_freemsgmem(&msg);
				memset(&msg,0,sizeof(smbmsg_t));		

				/* Parse message header here */
				hfield_type=UNKNOWN;
				smb_error=SMB_SUCCESS; /* no SMB error */
				errmsg=insuf_stor;
				while(!feof(msgtxt)) {
					char field[32];

					if(!fgets(buf,sizeof(buf),msgtxt))
						break;
					truncsp(buf);
					if(buf[0]==0)	/* blank line marks end of header */
						break;

					if((p=get_header_field(buf, field, sizeof(field)))!=NULL) {
						if(stricmp(field, "SUBJECT")==0) {
							/* SPAM Filtering/Logging */
							if(relay_user.number==0) {
								if(trashcan(&scfg,p,"subject")) {
									lprintf(LOG_NOTICE,"%04d !SMTP BLOCKED SUBJECT (%s) from: %s (%u total)"
										,socket, p, reverse_path, ++stats.msgs_refused);
									SAFEPRINTF2(tmp,"Blocked subject (%s) from: %s"
										,p, reverse_path);
									spamlog(&scfg, "SMTP", "REFUSED"
										,tmp, host_name, host_ip, rcpt_addr, reverse_path);
									errmsg="554 Subject not allowed.";
									smb_error=SMB_FAILURE;
									break;
								}
								if(dnsbl_result.s_addr && startup->dnsbl_tag[0] && !(startup->options&MAIL_OPT_DNSBL_IGNORE)) {
									safe_snprintf(str,sizeof(str),"%.*s: %.*s"
										,(int)sizeof(str)/2, startup->dnsbl_tag
										,(int)sizeof(str)/2, p);
									p=str;
									lprintf(LOG_NOTICE,"%04d SMTP TAGGED MAIL SUBJECT from blacklisted server with: %s"
										,socket, startup->dnsbl_tag);
								}
							}
							smb_hfield_str(&msg, SUBJECT, p);
							continue;
						}
						if(relay_user.number==0	&& stricmp(field, "FROM")==0
							&& !chk_email_addr(socket,p,host_name,host_ip,rcpt_addr,reverse_path,"FROM")) {
							errmsg="554 Sender not allowed.";
							smb_error=SMB_FAILURE;
							break;
						}
						if(relay_user.number==0 && stricmp(field, "TO")==0 && !spam_bait_result
							&& !chk_email_addr(socket,p,host_name,host_ip,rcpt_addr,reverse_path,"TO")) {
							errmsg="550 Unknown user.";
							smb_error=SMB_FAILURE;
							break;
						}
					}
					if((smb_error=parse_header_field(buf,&msg,&hfield_type))!=SMB_SUCCESS) {
						if(smb_error==SMB_ERR_HDR_LEN)
							lprintf(LOG_WARNING,"%04d !SMTP MESSAGE HEADER EXCEEDS %u BYTES"
								,socket, SMB_MAX_HDR_LEN);
						else
							lprintf(LOG_ERR,"%04d !SMTP ERROR %d adding header field: %s"
								,socket, smb_error, buf);
						break;
					}
				}
				if(smb_error!=SMB_SUCCESS) {	/* SMB Error */
					sockprintf(socket, errmsg);
					stats.msgs_refused++;
					continue;
				}
				if((p=smb_get_hfield(&msg, RFC822TO, NULL))!=NULL) {
					parse_mail_address(p
						,rcpt_name	,sizeof(rcpt_name)-1
						,rcpt_addr	,sizeof(rcpt_addr)-1);
				}
				if((p=smb_get_hfield(&msg, RFC822FROM, NULL))!=NULL) {
					parse_mail_address(p 
						,sender		,sizeof(sender)-1
						,sender_addr,sizeof(sender_addr)-1);
				}
				dnsbl_recvhdr=FALSE;
				if(startup->options&MAIL_OPT_DNSBL_CHKRECVHDRS)  {
					for(i=0;!dnsbl_result.s_addr && i<msg.total_hfields;i++)  {
						if(msg.hfield[i].type == SMTPRECEIVED)  {
							if(chk_received_hdr(socket,msg.hfield_dat[i],&dnsbl_result,dnsbl,dnsbl_ip)) {
								dnsbl_recvhdr=TRUE;
								break;
							}
						}
					}
				}
				if(relay_user.number==0 && dnsbl_result.s_addr && !(startup->options&MAIL_OPT_DNSBL_IGNORE)) {
					/* tag message as spam */
					if(startup->dnsbl_hdr[0]) {
						safe_snprintf(str,sizeof(str),"%s: %s is listed on %s as %s"
							,startup->dnsbl_hdr, dnsbl_ip
							,dnsbl, inet_ntoa(dnsbl_result));
						smb_hfield_str(&msg, RFC822HEADER, str);
						lprintf(LOG_NOTICE,"%04d SMTP TAGGED MAIL HEADER from blacklisted server with: %s"
							,socket, startup->dnsbl_hdr);
					}
					if(startup->dnsbl_hdr[0] || startup->dnsbl_tag[0]) {
						SAFEPRINTF2(str,"Listed on %s as %s", dnsbl, inet_ntoa(dnsbl_result));
						spamlog(&scfg, "SMTP", "TAGGED", str, host_name, dnsbl_ip, rcpt_addr, reverse_path);
					}
				}
				if(dnsbl_recvhdr)			/* DNSBL-listed IP found in Received header? */
					dnsbl_result.s_addr=0;	/* Reset DNSBL look-up result between messages */

				if(sender[0]==0) {
					lprintf(LOG_WARNING,"%04d !SMTP MISSING mail header 'FROM' field (%u total)"
						,socket, ++stats.msgs_refused);
					sockprintf(socket, "554 Mail header missing 'FROM' field");
					subnum=INVALID_SUB;
					continue;
				}
				if(relay_user.number) {
					SAFEPRINTF(str,"%u",relay_user.number);
					smb_hfield_str(&msg, SENDEREXT, str);
				}
				if(relay_user.number && subnum!=INVALID_SUB) {
					nettype=NET_NONE;
					smb_hfield_str(&msg, SENDER, relay_user.alias);
				} else {
					nettype=NET_INTERNET;
					smb_hfield_str(&msg, SENDER, sender);
					smb_hfield(&msg, SENDERNETTYPE, sizeof(nettype), &nettype);
					smb_hfield_str(&msg, SENDERNETADDR, sender_addr);
				}
				smb_hfield_str(&msg, SMTPREVERSEPATH, reverse_path);
				if(msg.subj==NULL)
					smb_hfield(&msg, SUBJECT, 0, NULL);

				length=filelength(fileno(msgtxt))-ftell(msgtxt);

				if(startup->max_msg_size && length>startup->max_msg_size) {
					lprintf(LOG_WARNING,"%04d !SMTP Message size (%lu) exceeds maximum: %lu bytes"
						,socket,length,startup->max_msg_size);
					sockprintf(socket, "552 Message size (%lu) exceeds maximum: %lu bytes"
						,length,startup->max_msg_size);
					subnum=INVALID_SUB;
					stats.msgs_refused++;
					continue;
				}

				if((msgbuf=(char*)malloc(length+1))==NULL) {
					lprintf(LOG_CRIT,"%04d !SMTP ERROR allocating %d bytes of memory"
						,socket,length+1);
					sockprintf(socket, insuf_stor);
					subnum=INVALID_SUB;
					continue;
				}
				fread(msgbuf,length,1,msgtxt);
				msgbuf[length]=0;	/* ASCIIZ */

				/* Do external JavaScript processing here? */

				if(subnum!=INVALID_SUB) {	/* Message Base */
					uint reason;
					if(relay_user.number==0)
						memset(&relay_user,0,sizeof(relay_user));

					if(!can_user_post(&scfg,subnum,&relay_user,&client,&reason)) {
						lprintf(LOG_WARNING,"%04d !SMTP %s (user #%u) cannot post on %s (reason: %u)"
							,socket, sender_addr, relay_user.number
							,scfg.sub[subnum]->sname, reason);
						sockprintf(socket,"550 Insufficient access");
						subnum=INVALID_SUB;
						stats.msgs_refused++;
						continue;
					}

					if(rcpt_name[0]==0)
						strcpy(rcpt_name,"All");
					smb_hfield_str(&msg, RECIPIENT, rcpt_name);

					smb.subnum=subnum;
					if((i=savemsg(&scfg, &smb, &msg, &client, startup->host_name, msgbuf))!=SMB_SUCCESS) {
						lprintf(LOG_WARNING,"%04d !SMTP ERROR %d (%s) saving message"
							,socket,i,smb.last_error);
						sockprintf(socket, "452 ERROR %d (%s) saving message"
							,i,smb.last_error);
					} else {
						lprintf(LOG_INFO,"%04d SMTP %s posted a message on %s"
							,socket, sender_addr, scfg.sub[subnum]->sname);
						sockprintf(socket,ok_rsp);
						if(relay_user.number != 0)
							user_posted_msg(&scfg, &relay_user, 1);
						signal_smtp_sem();
					}
					free(msgbuf);
					smb_close(&smb);
					subnum=INVALID_SUB;
					continue;
				}

				/* Create/check hashes of known SPAM */
				{
					hash_t**	hashes;
					BOOL		is_spam=spam_bait_result;
					long		sources=SMB_HASH_SOURCE_SPAM;

					if((dnsbl_recvhdr || dnsbl_result.s_addr) && startup->options&MAIL_OPT_DNSBL_SPAMHASH)
						is_spam=TRUE;

					if(msg.subj==NULL || strlen(msg.subj) < SPAM_HASH_SUBJECT_MIN_LEN)
						sources&=~(1<<SMB_HASH_SOURCE_SUBJECT);
					lprintf(LOG_DEBUG,"%04d SMTP Calculating message hashes (sources=%lx, msglen=%u)"
						,socket, sources, strlen(msgbuf));
					if((hashes=smb_msghashes(&msg, msgbuf, sources)) != NULL) {
						hash_t	found;

						for(i=0;hashes[i];i++)
							lprintf(LOG_DEBUG,"%04d SMTP Message %s crc32=%lx flags=%lx length=%u"
								,socket, smb_hashsourcetype(hashes[i]->source)
								,hashes[i]->crc32, hashes[i]->flags, hashes[i]->length);

						if((i=smb_findhash(&spam, hashes, &found, sources, /* Mark: */TRUE))==SMB_SUCCESS) {
							SAFEPRINTF3(str,"%s (%s) found in SPAM database (added on %s)"
								,smb_hashsourcetype(found.source)
								,smb_hashsource(&msg,found.source)
								,timestr(&scfg,found.time,tmp)
								);
							lprintf(LOG_NOTICE,"%04d SMTP Message %s", socket, str);
							if(!is_spam) {
								spamlog(&scfg, "SMTP", "IGNORED"
									,str, host_name, host_ip, rcpt_addr, reverse_path);
								is_spam=TRUE;
							}
						} else if(i!=SMB_ERR_NOT_FOUND)
							lprintf(LOG_ERR,"%04d !SMTP ERROR %d (%s) opening SPAM database"
								,socket, i, spam.last_error);
						
						if(is_spam) {
							size_t	n,total=0;
							for(n=0;hashes[n]!=NULL;n++)
								if(!(hashes[n]->flags&SMB_HASH_MARKED)) {
									lprintf(LOG_INFO,"%04d SMTP Adding message %s (%s) to SPAM database"
										,socket
										,smb_hashsourcetype(hashes[n]->source)
										,smb_hashsource(&msg,hashes[n]->source)
										);
									total++;
								}
							if(total) {
								lprintf(LOG_DEBUG,"%04d SMTP Adding %u message hashes to SPAM database", socket, total);
								smb_addhashes(&spam, hashes, /* skip_marked: */TRUE);
							}
							if(i!=SMB_SUCCESS && !spam_bait_result && (dnsbl_recvhdr || dnsbl_result.s_addr))