mailsrvr.c

	smb_t		smb;
	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_match;
	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;

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

	free(arg);

	socket=smtp.socket;

	lprintf(LOG_DEBUG,"%04d SMTP RX 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_ERR,"%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_match=alloca(sizeof(BOOL)*mailproc_count))==NULL) {
		lprintf(LOG_ERR,"%04d !SMTP ERROR allocating memory for mailproc_match", socket);
		sockprintf(socket,sys_error);
		mail_close_socket(socket);
		thread_down();
		return;
	} 
	memset(mailproc_match,FALSE,sizeof(BOOL)*mailproc_count);

	memset(&smb,0,sizeof(smb));
	memset(&msg,0,sizeof(msg));
	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);
		for(i=0;host!=NULL && host->h_aliases!=NULL && host->h_aliases[i]!=NULL;i++)
			lprintf(LOG_INFO,"%04d SMTP HostAlias: %s", socket, host->h_aliases[i]);
#if 0
		if(host!=NULL) {
			ip=resolve_ip(host_name);
			if(ip!=smtp.client_addr.sin_addr.s_addr) {
				smtp.client_addr.sin_addr.s_addr=ip;
				lprintf(LOG_WARNING,"%04d !SMTP DNS/IP ADDRESS MISMATCH: %s vs %s"
					,socket, inet_ntoa(smtp.client_addr.sin_addr), host_ip);
				sockprintf(socket,"550 DNS and IP address mismatch");
				mail_close_socket(socket);
				thread_down();
				return;
			}
		}
#endif
	}

	active_clients++, update_clients();

	SAFECOPY(hello_name,host_name);

	sprintf(spam_bait,"%sspambait.cfg",scfg.ctrl_dir);
	sprintf(spam_block,"%sspamblock.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)) {
			lprintf(LOG_NOTICE,"%04d !SMTP BLOCKED SERVER IP ADDRESS: %s"
				,socket, host_ip);
			sockprintf(socket,"550 Access denied.");
			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)) {
			lprintf(LOG_NOTICE,"%04d !SMTP BLOCKED SERVER HOSTNAME: %s"
				,socket, host_name);
			sockprintf(socket,"550 Access denied.");
			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_WARNING,"%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_WARNING,"%04d !SMTP REFUSED SESSION from blacklisted server"
					,socket);
				thread_down();
				if(active_clients)
					active_clients--, update_clients();
				return;
			}
		}
	}

	sprintf(smb.file,"%smail",scfg.data_dir);
	if(smb_islocked(&smb)) {
		lprintf(LOG_WARNING,"%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;
	}

	srand(time(NULL) ^ (DWORD)GetCurrentThreadId());	/* seed random number generator */
	rand();	/* throw-away first result */
	SAFEPRINTF4(session_id,"%x%x%x%lx",getpid(),socket,rand(),clock());
	SAFEPRINTF2(msgtxt_fname,"%sSBBS_SMTP.%s.msg", 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_ERR,"%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")) {
		sprintf(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);

	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);

				/* Twit-listing (sender's name and e-mail addresses) here */
				sprintf(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>"
						,socket, sender, sender_addr);
					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_name,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_name,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_name, rcpt_addr);
						else
							lprintf(LOG_ERR,"%04d !SMTP ERROR %d creating telegram from %s to %s <%s>"
								,socket, i, sender_addr, rcpt_name, 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++) {

						if(mailproc_list[i].disabled)
							continue;

						/* This processor is for specific recipients only and did not match */
						if(strListCount(mailproc_list[i].to) && !mailproc_match[i])
							continue;

						if(!mailproc_list[i].passthru)
							msg_handled=TRUE;

						mailcmdstr(mailproc_list[i].cmdline
							,msgtxt_fname, rcptlst_fname, proc_err_fname
							,host_name, host_ip, relay_user.number
							,sender, sender_addr, reverse_path, str);
						lprintf(LOG_DEBUG,"%04d SMTP Executing external process: %s"
							,socket, str);

						if(mailproc_list[i].native) {
							if((j=system(str))!=0)
								lprintf(LOG_WARNING,"%04d !SMTP system(%s) returned %d (errno: %d)"
									,socket, str, j, errno);
						} else  /* JavaScript */
							js_mailproc(socket, &client, &relay_user, str /* cmdline */
								,msgtxt_fname, rcptlst_fname, proc_err_fname
								,sender, sender_addr, reverse_path);
						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)) {
							if(!fgets(str,sizeof(str),proc_err))
								break;
							truncsp(str);
							lprintf(LOG_WARNING,"%04d !SMTP external process error: %s", socket, str);
							i=atoi(str);
							if(i>=100 && i<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_WARNING,"%04d SMTP External process removed %s file"
							,socket, 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"
						,socket);
					continue;
				}

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

					if(!strnicmp(buf, "SUBJECT:",8)) {
						p=buf+8;
						SKIP_WHITESPACE(p);
						if(relay_user.number==0	&& 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_WARNING,"%04d !SMTP TAGGED MAIL SUBJECT from blacklisted server with: %s"
								,socket, startup->dnsbl_tag);
						}
						smb_hfield_str(&msg, SUBJECT, p);
						continue;
					}
					if(!strnicmp(buf, "FROM:", 5)
						&& !chk_email_addr(socket,buf+5,host_name,host_ip,rcpt_addr,reverse_path,"FROM")) {
						errmsg="554 Sender not allowed.";
						smb_error=SMB_FAILURE;
						break;
					}
					if(!strnicmp(buf, "TO:", 3)
						&& !chk_email_addr(socket,buf+3,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);
					continue;
				}
				if((p=smb_get_hfield(&msg, RFC822TO, NULL))!=NULL) {
					if(*p=='<')	p++;
					SAFECOPY(rcpt_name,p);
					truncstr(rcpt_name,">");
				}
				if((p=smb_get_hfield(&msg, RFC822FROM, NULL))!=NULL) {
					parse_mail_address(p 
						,sender		,sizeof(sender)-1
						,sender_addr,sizeof(sender_addr)-1);
				}

				/* SPAM Filtering/Logging */
				if(relay_user.number==0 && msg.subj!=NULL && trashcan(&scfg,msg.subj,"subject")) {
					lprintf(LOG_WARNING,"%04d !SMTP BLOCKED SUBJECT (%s) from: %s"
						,socket, msg.subj, reverse_path);
					SAFEPRINTF2(tmp,"Blocked subject (%s) from: %s"
						,msg.subj, reverse_path);
					spamlog(&scfg, "SMTP", "REFUSED"
						,tmp, host_name, host_ip, rcpt_addr, reverse_path);
					sockprintf(socket, "554 Subject not allowed.");
					continue;
				}
				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 == RFC822HEADER
							&& strnicmp(msg.hfield_dat[i],"Received:",9)==0)  {
							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) {
					if(startup->options&MAIL_OPT_DNSBL_IGNORE) {
						lprintf(LOG_WARNING,"%04d !SMTP IGNORED MAIL from blacklisted server"
							,socket);
						SAFEPRINTF2(str,"Listed on %s as %s", dnsbl, inet_ntoa(dnsbl_result));
						spamlog(&scfg, "SMTP", "IGNORED"
							,str, host_name, dnsbl_ip, rcpt_addr, reverse_path);
						/* pretend we received it */
						sockprintf(socket,ok_rsp);
						continue;
					}
					/* 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_WARNING,"%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", socket);
					sockprintf(socket, "554 Mail header missing 'FROM' field");
					subnum=INVALID_SUB;
					continue;
				}
				nettype=NET_INTERNET;
				smb_hfield_str(&msg, SMTPREVERSEPATH, reverse_path);
				smb_hfield_str(&msg, SENDER, sender);
				smb_hfield(&msg, SENDERNETTYPE, sizeof(nettype), &nettype);
				smb_hfield_str(&msg, SENDERNETADDR, sender_addr);
				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;
					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,&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;
						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, 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);
						signal_smtp_sem();
					}
					free(msgbuf);
					smb_close(&smb);
					subnum=INVALID_SUB;
					continue;
				}

				/* E-mail */
				smb.subnum=INVALID_SUB;
				/* creates message data, but no header or index records (since msg.to==NULL) */
				i=savemsg(&scfg, &smb, &msg, &client, msgbuf);
				free(msgbuf);
				if(i!=SMB_SUCCESS) {
					smb_close(&smb);
					lprintf(LOG_ERR,"%04d !SMTP ERROR %d (%s) saving message"
						,socket,i,smb.last_error);
					sockprintf(socket, "452 ERROR %d (%s) saving message"
						,i,smb.last_error);
					continue;
				}

				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_name,iniReadString(rcptlst,section	,smb_hfieldtype(RECIPIENT),"unknown",value));
					usernum=iniReadInteger(rcptlst,section				,smb_hfieldtype(RECIPIENTEXT),0);
					agent=iniReadShortInt(rcptlst,section				,smb_hfieldtype(RECIPIENTAGENT),AGENT_PERSON);
					nettype=iniReadShortInt(rcptlst,section				,smb_hfieldtype(RECIPIENTNETTYPE),NET_NONE);
					sprintf(str,"#%u",usernum);
					SAFECOPY(rcpt_addr,iniReadString(rcptlst,section	,smb_hfieldtype(RECIPIENTNETADDR),str,value));

					if(nettype==NET_NONE /* Local destination */ && usernum==0) {
						lprintf(LOG_ERR,"%04d !SMTP can't deliver mail to user #0"
							,socket);
						break;
					}

					if((i=smb_copymsgmem(&smb,&newmsg,&msg))!=SMB_SUCCESS) {
						lprintf(LOG_ERR,"%04d !SMTP ERROR %d (%s) copying message"
							,socket, i, smb.last_error);
						break;
					}

					snprintf(hdrfield,sizeof(hdrfield),
						"Received: from %s (%s [%s])\r\n"
						"          by %s [%s] (Synchronet Mail Server %s-%s) with %s\r\n"
						"          for %s; %s"
						,host_name,hello_name,host_ip
						,startup->host_name,inet_ntoa(server_addr.sin_addr)
						,revision,PLATFORM_DESC
						,esmtp ? "ESMTP" : "SMTP"
						,rcpt_name,msgdate(msg.hdr.when_imported,date));
					smb_hfield_str(&newmsg, RFC822HEADER, hdrfield);

					smb_hfield_str(&newmsg, RECIPIENT, rcpt_name);

					if(usernum && nettype!=NET_INTERNET) {	/* Local destination or QWKnet routed */
						/* This is required for fixsmb to be able to rebuild the index */
						sprintf(str,"%u",usernum);
						smb_hfield_str(&newmsg, RECIPIENTEXT, str);
					}
					if(nettype!=NET_NONE) {
						smb_hfield(&newmsg, RECIPIENTNETTYPE, sizeof(nettype), &nettype);
						smb_hfield_str(&newmsg, RECIPIENTNETADDR, rcpt_addr);
					}
					if(agent!=newmsg.to_agent)
						smb_hfield(&newmsg, RECIPIENTAGENT, sizeof(agent), &agent);

					i=smb_addmsghdr(&smb,&newmsg,SMB_SELFPACK);
					smb_freemsgmem(&newmsg);
					if(i!=SMB_SUCCESS) {
						lprintf(LOG_ERR,"%04d !SMTP ERROR %d (%s) adding message header"
							,socket, i, smb.last_error);
						break;
					}
					lprintf(LOG_INFO,"%04d SMTP Created message #%ld from %s to %s <%s>"
						,socket, newmsg.hdr.number, sender, rcpt_name, rcpt_addr);
					if(!(startup->options&MAIL_OPT_NO_NOTIFY) && usernum
						&& !dnsbl_recvhdr && !dnsbl_result.s_addr) {
						safe_snprintf(str,sizeof(str)
							,"\7\1n\1hOn %.24s\r\n\1m%s \1n\1msent you e-mail from: "
							"\1h%s\1n\r\n"
							,timestr(&scfg,newmsg.hdr.when_imported.time,tmp)
							,sender,sender_addr);
						if(!newmsg.idx.to) {	/* Forwarding */
							strcat(str,"\1mand it was automatically forwarded to: \1h");
							strcat(str,rcpt_addr);
							strcat(str,"\1n\r\n");
						}
						putsmsg(&scfg, usernum, str);
					}
				}
				iniFreeStringList(sec_list);
				if(rcpt_count<1) {
					smb_freemsg_dfields(&smb,&msg,SMB_ALL_REFS);
					sockprintf(socket, insuf_stor);
				}
				else {
					if(rcpt_count>1)
						smb_incmsg_dfields(&smb,&msg,(ushort)(rcpt_count-1));
					sockprintf(socket,ok_rsp);
					signal_smtp_sem();
				}
#if 0 /* This shouldn't be necessary here */
				smb_close_da(&smb);
#endif
				smb_close(&smb);
				continue;
			}
			if(buf[0]==0 && state==SMTP_STATE_DATA_HEADER) {	
				state=SMTP_STATE_DATA_BODY;	/* Null line separates header and body */
				lines=0;
				if(msgtxt!=NULL) {
					fprintf(msgtxt, "\r\n");
					hdr_len=ftell(msgtxt);
				}
				continue;
			}
			if(state==SMTP_STATE_DATA_BODY) {
				p=buf;
				if(*p=='.') p++;	/* Transparency (RFC821 4.5.2) */
				if(msgtxt!=NULL) 
					fprintf(msgtxt, "%s\r\n", p);
				lines++;
				/* release time-slices every x lines */
				if(startup->lines_per_yield &&
					!(lines%startup->lines_per_yield))	
					YIELD();
				continue;
			}
			/* RFC822 Header parsing */
			if(startup->options&MAIL_OPT_DEBUG_RX_HEADER)
				lprintf(LOG_DEBUG,"%04d SMTP %s",socket, buf);

			if(!strnicmp(buf, "FROM:", 5))
				parse_mail_address(buf+5
					,sender,		sizeof(sender)-1
					,sender_addr,	sizeof(sender_addr)-1);

			if(msgtxt!=NULL) 
				fprintf(msgtxt, "%s\r\n", buf);
			hdr_lines++;
			continue;
		}
		strip_ctrl(buf);
		lprintf(LOG_DEBUG,"%04d SMTP RX: %s", socket, buf);
		if(!strnicmp(buf,"HELO",4)) {
			p=buf+4;
			SKIP_WHITESPACE(p);
			SAFECOPY(hello_name,p);
			sockprintf(socket,"250 %s",startup->host_name);
			esmtp=FALSE;
			state=SMTP_STATE_HELO;
			cmd=SMTP_CMD_NONE;
			telegram=FALSE;
			subnum=INVALID_SUB;
			continue;
		}
		if(!strnicmp(buf,"EHLO",4)) {
			p=buf+4;
			SKIP_WHITESPACE(p);
			SAFECOPY(hello_name,p);
			sockprintf(socket,"250-%s",startup->host_name);
			sockprintf(socket,"250 AUTH PLAIN LOGIN CRAM-MD5");
			esmtp=TRUE;
			state=SMTP_STATE_HELO;
			cmd=SMTP_CMD_NONE;
			telegram=FALSE;
			subnum=INVALID_SUB;
			continue;
		}
		if((auth_login=(stricmp(buf,"AUTH LOGIN")==0))==TRUE 
			|| strnicmp(buf,"AUTH PLAIN",10)==0) {
			if(auth_login) {
				sockprintf(socket,"334 VXNlcm5hbWU6");	/* Base64-encoded "Username:" */
				if((rd=sockreadline(socket, buf, sizeof(buf)))<1) {
					sockprintf(socket,badarg_rsp);
					continue;
				}
				if(startup->options&MAIL_OPT_DEBUG_RX_RSP) 
					lprintf(LOG_DEBUG,"%04d RX: %s",socket,buf);
				if(b64_decode(user_name,sizeof(user_name),buf,rd)<1) {
					sockprintf(socket,badarg_rsp);
					continue;
				}
				sockprintf(socket,"334 UGFzc3dvcmQ6");	/* Base64-encoded "Password:" */
				if((rd=sockreadline(socket, buf, sizeof(buf)))<1) {
					sockprintf(socket,badarg_rsp);
					continue;
				}
				if(startup->options&MAIL_OPT_DEBUG_RX_RSP) 
					lprintf(LOG_DEBUG,"%04d RX: %s",socket,buf);
				if(b64_decode(user_pass,sizeof(user_pass),buf,rd)<1) {
					sockprintf(socket,badarg_rsp);
					continue;
				}
			} else {	/* AUTH PLAIN b64(<username>\0<user-id>\0<password>) */
				p=buf+10;
				SKIP_WHITESPACE(p);
				if(*p==0) {
					sockprintf(socket,badarg_rsp);
					continue;
				}
				ZERO_VAR(tmp);
				if(b64_decode(tmp,sizeof(tmp),p,strlen(p))<1) {
					sockprintf(socket,badarg_rsp);
					continue;
				}
				p=tmp;
				while(*p) p++;	/* skip username */
				p++;			/* skip NULL */
				if(*p==0) {
					sockprintf(socket,badarg_rsp);
					continue;
				}
				SAFECOPY(user_name,p);
				while(*p) p++;	/* skip user-id */
				p++;			/* skip NULL */
				if(*p==0) {
					sockprintf(socket,badarg_rsp);
					continue;
				}
				SAFECOPY(user_pass,p);
			}

			if((relay_user.number=matchuser(&scfg,user_name,FALSE))==0) {
				if(scfg.sys_misc&SM_ECHO_PW)
					lprintf(LOG_WARNING,"%04d !SMTP UNKNOWN USER: %s (password: %s)"
						,socket, user_name, user_pass);
				else
					lprintf(LOG_WARNING,"%04d !SMTP UNKNOWN USER: %s"
						,socket, user_name);
				sockprintf(socket,badauth_rsp);
				continue;
			}
			if((i=getuserdat(&scfg, &relay_user))!=0) {
				lprintf(LOG_ERR,"%04d !SMTP ERROR %d getting data on user (%s)"
					,socket, i, user_name);
				sockprintf(socket,badauth_rsp);
				relay_user.number=0;
				continue;
			}
			if(relay_user.misc&(DELETED|INACTIVE)) {
				lprintf(LOG_WARNING,"%04d !SMTP DELETED or INACTIVE user #%u (%s)"
					,socket, relay_user.number, user_name);
				sockprintf(socket,badauth_rsp);
				relay_user.number=0;
				break;
			}
			if(stricmp(user_pass,relay_user.pass)) {
				if(scfg.sys_misc&SM_ECHO_PW)
					lprintf(LOG_WARNING,"%04d !SMTP FAILED Password attempt for user %s: '%s' expected '%s'"
						,socket, user_name, user_pass, relay_user.pass);
				else
					lprintf(LOG_WARNING,"%04d !SMTP FAILED Password attempt for user %s"
						,socket, user_name);
				sockprintf(socket,badauth_rsp);
				relay_user.number=0;
				break;
			}
			/* Update client display */
			client.user=relay_user.alias;
			client_on(socket,&client,TRUE /* update */);

			lprintf(LOG_INFO,"%04d SMTP %s authenticated using %s authentication"
				,socket,relay_user.alias,auth_login ? "LOGIN" : "PLAIN");
			sockprintf(socket,auth_ok);
			continue;
		}
		if(!stricmp(buf,"AUTH CRAM-MD5")) {
			safe_snprintf(challenge,sizeof(challenge),"<%x%x%lx%lx@%s>"
				,rand(),socket,(ulong)time(NULL),clock(),startup->host_name);
#if 0
			lprintf(LOG_DEBUG,"%04d SMTP CRAM-MD5 challenge: %s"
				,socket,challenge);
#endif
			b64_encode(str,sizeof(str),challenge,0);
			sockprintf(socket,"334 %s",str);
			if((rd=sockreadline(socket, buf, sizeof(buf)))<1) {
				sockprintf(socket,badarg_rsp);
				continue;
			}
			if(startup->options&MAIL_OPT_DEBUG_RX_RSP) 
				lprintf(LOG_DEBUG,"%04d RX: %s",socket,buf);

			if(b64_decode(response,sizeof(response),buf,rd)<1) {
				sockprintf(socket,badarg_rsp);
				continue;
			}
#if 0
			lprintf(LOG_DEBUG,"%04d SMTP CRAM-MD5 response: %s"
				,socket,response);
#endif
			if((p=strrchr(response,' '))!=NULL)
				*(p++)=0;
			else
				p=response;
			SAFECOPY(user_name,response);
			if((relay_user.number=matchuser(&scfg,user_name,FALSE))==0) {
				lprintf(LOG_WARNING,"%04d !SMTP UNKNOWN USER: %s"
					,socket, user_name);
				sockprintf(socket,badauth_rsp);
				continue;
			}
			if((i=getuserdat(&scfg, &relay_user))!=0) {
				lprintf(LOG_ERR,"%04d !SMTP ERROR %d getting data on user (%s)"
					,socket, i, user_name);
				sockprintf(socket,badauth_rsp);
				relay_user.number=0;
				continue;
			}
			if(relay_user.misc&(DELETED|INACTIVE)) {
				lprintf(LOG_WARNING,"%04d !SMTP DELETED or INACTIVE user #%u (%s)"
					,socket, relay_user.number, user_name);
				sockprintf(socket,badauth_rsp);
				relay_user.number=0;
				continue;
			}
			/* Calculate correct response */
			memset(secret,0,sizeof(secret));
			SAFECOPY(secret,relay_user.pass);
			strlwr(secret);	/* this is case sensitive, so convert to lowercase first */
			for(i=0;i<sizeof(secret);i++)
				md5_data[i]=secret[i]^0x36;	/* ipad */
			strcpy(md5_data+i,challenge);
			MD5_calc(digest,md5_data,sizeof(secret)+strlen(challenge));
			for(i=0;i<sizeof(secret);i++)
				md5_data[i]=secret[i]^0x5c;	/* opad */
			memcpy(md5_data+i,digest,sizeof(digest));
			MD5_calc(digest,md5_data,sizeof(secret)+sizeof(digest));
			MD5_hex(str,digest);
			if(strcmp(p,str)) {
				lprintf(LOG_WARNING,"%04d !SMTP %s FAILED CRAM-MD5 authentication"
					,socket,relay_user.alias);
#if 0
				lprintf(LOG_DEBUG,"%04d !SMTP calc digest: %s"
					,socket,str);
				lprintf(LOG_DEBUG,"%04d !SMTP resp digest: %s"
					,socket,p);
#endif
				sockprintf(socket,badauth_rsp);
				relay_user.number=0;
				continue;
			}
			/* Update client display */
			client.user=relay_user.alias;
			client_on(socket,&client,TRUE /* update */);

			lprintf(LOG_INFO,"%04d SMTP %s authenticated using CRAM-MD5 authentication"
				,socket,relay_user.alias);
			sockprintf(socket,auth_ok);
			continue;
		}
		if(!strnicmp(buf,"AUTH",4)) {
			sockprintf(socket,"504 Unrecognized authentication type.");
			continue;
		}
		if(!stricmp(buf,"QUIT")) {
			sockprintf(socket,"221 %s Service closing transmission channel",startup->host_name);
			break;
		} 
		if(!stricmp(buf,"NOOP")) {
			sockprintf(socket, ok_rsp);
			badcmds=0;
			continue;
		}
		if(state<SMTP_STATE_HELO) {
			/* RFC 821 4.1.1 "The first command in a session must be the HELO command." */
			lprintf(LOG_WARNING,"%04d !SMTP MISSING 'HELO' command",socket);
			sockprintf(socket, badseq_rsp);
			continue;
		}
		if(!stricmp(buf,"TURN")) {
			sockprintf(socket,"502 command not supported");
			badcmds=0;
			continue;
		}
		if(!stricmp(buf,"RSET")) {
			smb_freemsgmem(&msg);
			memset(&msg,0,sizeof(smbmsg_t));		/* Initialize message header */
			reverse_path[0]=0;
			state=SMTP_STATE_HELO;
			cmd=SMTP_CMD_NONE;
			telegram=FALSE;
			subnum=INVALID_SUB;

			/* reset recipient list */
			if((rcptlst=freopen(rcptlst_fname,"w+",rcptlst))==NULL) {
				lprintf(LOG_ERR,"%04d !SMTP ERROR %d re-opening %s"
					,socket, errno, rcptlst_fname);
				sockprintf(socket,sys_error);
				break;
			}
			rcpt_count=0;

			memset(mailproc_match,FALSE,sizeof(BOOL)*mailproc_count);

			sockprintf(socket,ok_rsp);
			badcmds=0;
			lprintf(LOG_INFO,"%04d SMTP Session reset",socket);
			continue;
		}
		if(!strnicmp(buf,"MAIL FROM:",10)
			|| !strnicmp(buf,"SEND FROM:",10)	/* Send a Message (Telegram) to a local ONLINE user */
			|| !strnicmp(buf,"SOML FROM:",10)	/* Send OR Mail a Message to a local user */
			|| !strnicmp(buf,"SAML FROM:",10)	/* Send AND Mail a Message to a local user */
			) {
			p=buf+10;
			if(!chk_email_addr(socket,p,host_name,host_ip,NULL,NULL,"REVERSE PATH")) {
				sockprintf(socket, "554 Sender not allowed.");