Add the ``blacklist'' feature, which allows a path to a filename to

be used as a valid pattern in the access control language.

Patch obtained from ftp://ftp.porcupine.org/pub/security/ .

Requested by:	markm

contrib/tcp_wrappers/hosts_access.5

@@ -89,6 +89,13 @@ An expression of the form `n.n.n.n/m.m.m.m\' is interpreted as a
 bitwise AND of the address and the `mask\'. For example, the net/mask
 pattern `131.155.72.0/255.255.254.0\' matches every address in the
 range `131.155.72.0\' through `131.155.73.255\'.
+.IP \(bu
+A string that begins with a `/\' character is treated as a file
+name. A host name or address is matched if it matches any host name
+or address pattern listed in the named file. The file format is
+zero or more lines with zero or more host name or address patterns
+separated by whitespace.  A file name pattern can be used anywhere
+a host name or address pattern can be used.
 .SH WILDCARDS
 The access control language supports explicit wildcards:
 .IP ALL
@@ -326,7 +333,7 @@ in.tftpd: ALL: (/some/where/safe_finger -l @%h | \\
 	/usr/ucb/mail -s %d-%h root) &
 .fi
 .PP
-The safe_finger command comes with the tcpd wrapper and should be
+The safe_finger command is intended for use in back-fingering and should be
 installed in a suitable place. It limits possible damage from data sent
 by the remote finger server.  It gives better protection than the
 standard finger command.
@@ -350,6 +357,12 @@ capacity of an internal buffer; when an access control rule is not
 terminated by a newline character; when the result of %<letter>
 expansion would overflow an internal buffer; when a system call fails
 that shouldn\'t.  All problems are reported via the syslog daemon.
+.SH IMPLEMENTATION NOTES
+Some operating systems are distributed with TCP Wrappers as part of the
+base system. It is common for such systems to build wrapping functionality
+into networking utilities. Notably, some systems offer an \fIinetd\fR(8)
+which does not require the use of the \fItcpd\fR(8). Check your system's
+documentation for details.
 .SH FILES
 .na
 .nf
@@ -376,3 +389,4 @@ Eindhoven University of Technology
 Den Dolech 2, P.O. Box 513, 
 5600 MB Eindhoven, The Netherlands
 \" @(#) hosts_access.5 1.20 95/01/30 19:51:46
+\" $FreeBSD$

contrib/tcp_wrappers/hosts_access.c

@@ -15,6 +15,8 @@
   * Compile with -DNETGROUP if your library provides support for netgroups.
   * 
   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+  *
+  * $FreeBSD$
   */
 
 #ifndef lint
@@ -240,6 +242,26 @@ struct request_info *request;
     }
 }
 
+/* hostfile_match - look up host patterns from file */
+
+static int hostfile_match(path, host)
+char   *path;
+struct hosts_info *host;
+{
+    char    tok[BUFSIZ];
+    int     match = NO;
+    FILE   *fp;
+
+    if ((fp = fopen(path, "r")) != 0) {
+	while (fscanf(fp, "%s", tok) == 1 && !(match = host_match(tok, host)))
+	     /* void */ ;
+	fclose(fp);
+    } else if (errno != ENOENT) {
+	tcpd_warn("open %s: %m", path);
+    }
+    return (match);
+}
+
 /* host_match - match host name and/or address against pattern */
 
 static int host_match(tok, host)
@@ -267,6 +289,8 @@ struct host_info *host;
 	tcpd_warn("netgroup support is disabled");	/* not tcpd_jump() */
 	return (NO);
 #endif
+    } else if (tok[0] == '/') {			/* /file hack */
+	return (hostfile_match(tok, host));
     } else if (STR_EQ(tok, "KNOWN")) {		/* check address and name */
 	char   *name = eval_hostname(host);
 	return (STR_NE(eval_hostaddr(host), unknown) && HOSTNAME_KNOWN(name));

contrib/tcp_wrappers/tcpdchk.c

@@ -12,6 +12,8 @@
   * -v: show all rules.
   * 
   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+  *
+  * $FreeBSD$
   */
 
 #ifndef lint
@@ -350,6 +352,8 @@ char   *pat;
 {
     if (pat[0] == '@') {
 	tcpd_warn("%s: daemon name begins with \"@\"", pat);
+    } else if (pat[0] == '/') {
+	tcpd_warn("%s: daemon name begins with \"/\"", pat);
     } else if (pat[0] == '.') {
 	tcpd_warn("%s: daemon name begins with dot", pat);
     } else if (pat[strlen(pat) - 1] == '.') {
@@ -382,6 +386,8 @@ char   *pat;
 {
     if (pat[0] == '@') {			/* @netgroup */
 	tcpd_warn("%s: user name begins with \"@\"", pat);
+    } else if (pat[0] == '/') {
+	tcpd_warn("%s: user name begins with \"/\"", pat);
     } else if (pat[0] == '.') {
 	tcpd_warn("%s: user name begins with dot", pat);
     } else if (pat[strlen(pat) - 1] == '.') {
@@ -402,8 +408,13 @@ char   *pat;
 static int check_host(pat)
 char   *pat;
 {
+    char    buf[BUFSIZ];
     char   *mask;
     int     addr_count = 1;
+    FILE   *fp;
+    struct tcpd_context saved_context;
+    char   *cp;
+    char   *wsp = " \t\r\n";
 
     if (pat[0] == '@') {			/* @netgroup */
 #ifdef NO_NETGRENT
@@ -422,6 +433,21 @@ char   *pat;
 	tcpd_warn("netgroup support disabled");
 #endif
 #endif
+    } else if (pat[0] == '/') {			/* /path/name */
+	if ((fp = fopen(pat, "r")) != 0) {
+	    saved_context = tcpd_context;
+	    tcpd_context.file = pat;
+	    tcpd_context.line = 0;
+	    while (fgets(buf, sizeof(buf), fp)) {
+		tcpd_context.line++;
+		for (cp = strtok(buf, wsp); cp; cp = strtok((char *) 0, wsp))
+		    check_host(cp);
+	    }
+	    tcpd_context = saved_context;
+	    fclose(fp);
+	} else if (errno != ENOENT) {
+	    tcpd_warn("open %s: %m", pat);
+	}
     } else if (mask = split_at(pat, '/')) {	/* network/netmask */
 	if (dot_quad_addr(pat) == INADDR_NONE
 	    || dot_quad_addr(mask) == INADDR_NONE)