*** /tmp/,RCSt1a05857	Mon Sep 29 16:38:29 1997
--- smtpserver.c	Thu Sep 18 17:59:21 1997
***************
*** 23,30 ****
--- 23,31 ----
  #define	RKEY_FROM	"from"		/* mail from address verification */
  #define	RKEY_TO		"to"		/* recipient to address verification */
  #define	RKEY_VERIFY	"verify"	/* verify this address */
  #define	RKEY_EXPAND	"expand"	/* expand this address */
+ #define	RKEY_HELO	"helo"		/* HELO name verification */
  
  
  #include <stdio.h>
  #include "hostenv.h"
***************
*** 67,74 ****
--- 68,81 ----
  #ifndef	MAXHOSTNAMELEN
  #define	MAXHOSTNAMELEN 64
  #endif	/* MAXHOSTNAMELEN */
  
+ #ifdef	WRAPPERS
+ #include	"tcpd.h"
+ int		allow_severity = LOG_INFO;
+ int		deny_severity = LOG_WARNING;
+ #endif
+ 
  /*
   * Early inetd's, which may be found on 4.2BSD based systems (e.g.
   * Sun OS 3.x), are incapable of passing a flag to indicate we are
   * being run by inetd rather than directly.  Some hackery to detect
***************
*** 136,150 ****
--- 143,166 ----
  int	skeptical = 1;
  int	pid, routerpid;
  FILE	*logfp = NULL;
  
+ /* Connection limiting stuff */
+ int		maxkids = -1;
+ volatile int	curkids = 0;
+ int		nicekids = 0;		/* Do we give a 421 message? */
+ 
+ /* listen size. */
+ int		listensize = 5;
+ 
  /*
   * The "style" variable controls when the router is interrogated about the
   * validity of something.  It is a string of letter-flags:
   * f:	check MAIL FROM addresses
   * t:	check RCPT TO addresses
   * v:	check VRFY command argument
   * e:	check EXPN command argument
+  * h:	check HELO command argument
   */
  
  char	*style = "ve";
  
***************
*** 201,209 ****
  		(void) fprintf(stderr, "%s: gethostname(): %s\n",
  				       progname, strerror(errno));
  		exit(1);
  	}
! 	while ((c = getopt(argc, argv, "igl:np:P:R:s:V")) != EOF) {
  		switch (c) {
  		case 'i':	/* interactive */
  			daemon = 0;
  			break;
--- 217,225 ----
  		(void) fprintf(stderr, "%s: gethostname(): %s\n",
  				       progname, strerror(errno));
  		exit(1);
  	}
! 	while ((c = getopt(argc, argv, "igl:np:P:R:s:Vm:ML:")) != EOF) {
  		switch (c) {
  		case 'i':	/* interactive */
  			daemon = 0;
  			break;
***************
*** 237,244 ****
--- 253,272 ----
  		case 'V':
  			prversion("smtpserver");
  			exit(0);
  			break;	/* paranoia */
+ 
+ 		case 'm':	/* max simultaneous connections */
+ 			maxkids = atoi(optarg);
+ 			break;
+ 		case 'M':	/* give a 421 message when too many xns */
+ 			nicekids = 1;
+ 			break;
+ 		case 'L':	/* listen() backlog size */
+ 			listensize = atoi(optarg);
+ 			listensize = listensize > 0 ? listensize : 5;
+ 			break;
+ 
  		default:
  			++errflg;
  			break;
  		}
***************
*** 331,339 ****
  			(void) fprintf(stderr, "%s: bind(): %s\n",
  					       progname, strerror(errno));
  			exit(1);
  		}
! 		if (listen(s, 5) < 0) {
  			(void) fprintf(stderr, "%s: listen(): %s\n",
  					       progname, strerror(errno));
  			exit(1);
  		}
--- 359,367 ----
  			(void) fprintf(stderr, "%s: bind(): %s\n",
  					       progname, strerror(errno));
  			exit(1);
  		}
! 		if (listen(s, listensize) < 0) {
  			(void) fprintf(stderr, "%s: listen(): %s\n",
  					       progname, strerror(errno));
  			exit(1);
  		}
***************
*** 370,377 ****
--- 398,412 ----
  						       strerror(errno));
  					exit(1);
  				}
  			}
+ 
+ 			if (maxkids >= 0 && curkids >= maxkids && !nicekids) {
+ 				/* Just bail. */
+ 				(void) close(msgfd);
+ 				continue;
+ 			}
+ 
  			if ((pid = fork()) < 0) {	/* can't fork! */
  				(void) close(msgfd);
  				(void) fprintf(stderr,
  					       "%s: fork(): %s\n",
***************
*** 386,401 ****
  				if (msgfd != 1)
  					(void) dup2(msgfd, 1);
  				if (msgfd > 1)
  					(void) close(msgfd);
  				rport = raddr.sin_port;
  				setrhostname(&raddr);
  				smtpserver(1);
  				if (routerpid > 0)
  					killr(routerpid);
  				_exit(0);
! 			} else
  				(void) close(msgfd);
  		}
  	}
  #else	/* !USE_INET */
  	{
--- 421,444 ----
  				if (msgfd != 1)
  					(void) dup2(msgfd, 1);
  				if (msgfd > 1)
  					(void) close(msgfd);
+ 				/* If this is true, then we're being nice
+ 				   and giving a come-back-later message. */
+ 				if (maxkids >= 0 && curkids >= maxkids) {
+ 					type(421, "Service temporarily unavailable.");
+ 					_exit(0);
+ 				}
  				rport = raddr.sin_port;
  				setrhostname(&raddr);
  				smtpserver(1);
  				if (routerpid > 0)
  					killr(routerpid);
  				_exit(0);
! 			} else {
  				(void) close(msgfd);
+ 				curkids ++;
+ 			}
  		}
  	}
  #else	/* !USE_INET */
  	{
***************
*** 495,503 ****
  	while (wait3(&status, WNOHANG, (struct rusage *)NULL) > 0)
  #else	/* !WNOHANG */
  	while (wait(&status) > 0)
  #endif	/* WNOHANG */
! 		continue;
  	(void) signal(SIGCHLD, reaper);
  }
  
  void
--- 538,546 ----
  	while (wait3(&status, WNOHANG, (struct rusage *)NULL) > 0)
  #else	/* !WNOHANG */
  	while (wait(&status) > 0)
  #endif	/* WNOHANG */
! 		{ curkids --; continue; }
  	(void) signal(SIGCHLD, reaper);
  }
  
  void
***************
*** 537,544 ****
--- 580,628 ----
  	extern char *router(), *strerror();
  	extern int errno;
  	extern int cistrcmp(), partridge(), cistrncmp(), runastrusteduser();
  
+ #ifdef	WRAPPERS
+ 	struct request_info	rq;
+ 	struct sockaddr		sname;
+ 	int				snlen = sizeof(sname);
+ 	char			*dolog, *doreject;
+ 	/*
+ 	 * Check TCP wrappers configuration. Note that we do logging only
+ 	 * on rejected connections, since the smtpserver will already log good
+ 	 * ones. We log via the daemon facility to match the other TCPwrappers
+ 	 * stuff, and thus must closelog() afterwards so the later openlog() to
+ 	 * the mail facility will work.
+ 	 *	- cks
+ 	 */
+ 	/* Make tcpwrappers happy by only asking it about IP sockets. */
+ 	if (getsockname(1, &sname, &snlen) == 0 && sname.sa_family == AF_INET) {
+ 		(void) openlog("smtpserver", LOG_PID, LOG_DAEMON);
+ 		(void) request_init(&rq, RQ_FILE, 1, RQ_DAEMON, "smtpserver", 0);
+ 		fromhost(&rq);
+ 		if (!hosts_access(&rq)) {
+ 			/* Figure out what to do with it */
+ 			doreject = getenv("OPTREJECT");
+ 			dolog = getenv("OPTLOG");
+ 			if (!doreject || strcmp(doreject, "none") != 0)
+ 				type(550, doreject ? doreject : "Connection rejected due to connection origin.");
+ 			if (!dolog || strcmp(dolog, "none") != 0)
+ 				if (dolog)
+ 					syslog(deny_severity, "refused connect from %s: %s", eval_client(&rq), dolog);
+ 				else
+ 					syslog(deny_severity, "refused connect from %s", eval_client(&rq));
+ 			closelog();
+ 			/* Tear down the connection. */
+ 			return;
+ 		} else {
+ 			dolog = getenv("OPTLOG");
+ 			if (dolog && strcmp(dolog, "none") != 0)
+ 				syslog(allow_severity, "accepted connect from %s: %s", eval_client(&rq), dolog);
+ 		}
+ 		closelog();
+ 	}
+ #endif
+ 
  	/* opening the logfile should be done before we reset the uid */
  	if (logfile != NULL) {
  		if ((fd = open(logfile, O_CREAT|O_APPEND|O_WRONLY, 0644)) < 0) {
  			if (!insecure)
***************
*** 643,655 ****
--- 727,769 ----
  				}
  				type(503, cp);
  				break;
  			}
+ #if	0
  			if (sscanf(cp, "%s", helobuf) != 1) {
  				type(501, "What is your domain name?");
  				break;
  			}
+ #else
  			/*
+ 			 * parse the argument to HELO, if any, trimming off
+ 			 * leading and trailing spaces before we go on.
+ 			 * sscanf is not sufficient, because we want to catch
+ 			 * the case of spaces in the middle of the HELO, and
+ 			 * sscanf will normally stop as soon as it finds one.
+ 			 *			- cks
+ 			 */
+ 			{ char *tcp = cp; int ti;
+ 			while (isascii(*tcp) && isspace(*tcp))
+ 				tcp++;
+ 			if (*tcp == '\0') {
+ 				type(501, "What is your domain name?");
+ 				break;
+ 			} else {
+ 				/* this unguarded copy is safe, because
+ 				   we know that cp points into buf, and
+ 				   tcp points after cp, and that helobuf
+ 				   and buf are the same size.	- cks */
+ 				strcpy(helobuf, tcp);
+ 				ti = strlen(helobuf) - 1;
+ 				while (isascii(helobuf[ti]) &&
+ 				       isspace(helobuf[ti]))
+ 					ti--;
+ 				helobuf[ti+1] = '\0';
+ 			}
+ 			}
+ #endif
+ 			/*
  			 * Craig P. says we have to spit back syntactically
  			 * invalid helo parameters at this stage, which is
  			 * hard to do right since it requires a full '822
  			 * tokenizer.  We do a half-hearted attempt here.
***************
*** 665,672 ****
--- 779,800 ----
  				else
  					type(501, "Sorry, access denied.");
  				break;
  			}
+ 			/* Validate HELO if asked to. */
+ 			s = NULL;
+ 			if (STYLE(cfinfo, 'h')) {
+ 				if ((s = router(RKEY_HELO, 1, helobuf)) == NULL) {
+ 					/* the error was printed in router() */
+ 					break;
+ 				}
+ 				if (atoi(s) / 100 != 2) {
+ 					/* verification failed */
+ 					type(atoi(s), "%s", s+4);
+ 					free(s);
+ 					break;
+ 				}
+ 			}
  			/* check helobuf corresponds to the reverse address */
  			if (ihostaddr[0] != '\0'
  			    && rhostname[0] != '\0' && rhostname[0] != '['
  			    && cistrcmp(helobuf, rhostname) != 0) {
***************
*** 733,741 ****
  					/* the error was printed in router() */
  					break;
  				if (atoi(s) / 100 != 2) {
  					/* verification failed */
! 					type(atoi(s), s+4, "Failed", "Failed");
  					free(s);
  					break;
  				}
  			}
--- 861,869 ----
  					/* the error was printed in router() */
  					break;
  				if (atoi(s) / 100 != 2) {
  					/* verification failed */
! 					type(atoi(s), "%s", s+4);
  					free(s);
  					break;
  				}
  			}
***************
*** 831,839 ****
  					/* the error was printed in router() */
  					break;
  				if (atoi(s) / 100 != 2) {
  					/* verification failed */
! 					type(atoi(s), s+4, "Failed", "Failed");
  					free(s);
  					break;
  				}
  			}
--- 959,967 ----
  					/* the error was printed in router() */
  					break;
  				if (atoi(s) / 100 != 2) {
  					/* verification failed */
! 					type(atoi(s), "%s", s+4);
  					free(s);
  					break;
  				}
  			}
***************
*** 1238,1246 ****
  	}
  
  	bufsize = 10;
  	cp = buf = emalloc(bufsize);
! 	while ((*cp = getc(fp)) != EOF) {
  		if (*cp == '\n') {
  			*flagp = 0;
  			break;
  		}
--- 1366,1374 ----
  	}
  
  	bufsize = 10;
  	cp = buf = emalloc(bufsize);
! 	while (((*cp = getc(fp))) != EOF) {
  		if (*cp == '\n') {
  			*flagp = 0;
  			break;
  		}
***************
*** 1256,1264 ****
  			cp += s - buf;
  			buf = s;
  		}
  	}
! 	if (*cp == EOF) {
  		(void) printf("got EOF!\n");
  		free(buf);
  		return NULL;
  	}
--- 1384,1392 ----
  			cp += s - buf;
  			buf = s;
  		}
  	}
! 	if ((*cp) == EOF) {
  		(void) printf("got EOF!\n");
  		free(buf);
  		return NULL;
  	}