2000-08-25 H.J. Lu <hjl@lucon.org>

	* support/include/tcpwrapper.h: New for the tcp wrapper
	support.
	* support/misc/Makefile: Likewise.
	* support/misc/from_local.c: Likewise.
	* support/misc/tcpwrapper.c: Likewise.

	* aclocal.m4 (AC_TCP_WRAPPER): New.
	* configure.in: Use it. Substitute LIBWRAP.
	* configure: Rebuilt.

	* config.mk.in (LIBNSL): New.
	(LIBWRAP): Likewise.

	* support/Makefile (SUBDIRS): Add misc.

	* support/lib/Makefile (LIBS): Add libmisc.a.

	* utils/rquotad/Makefile (LIBS): Add

		-lmisc $(LIBWRAP) $(LIBNSL)

	* utils/statd/Makefile (LIBS): Likewise.

	* utils/rquotad/rquota_svc.c: Include "tcpwrapper.h" if
	HAVE_TCP_WRAPPER is defined.
	(rquotaprog_1): Call check_default () if HAVE_TCP_WRAPPER is
	defined. Reject an RPC call if check_default () fails.

	* utils/statd/statd.c: Include "tcpwrapper.h" if
	HAVE_TCP_WRAPPER is defined.
	(sm_prog_1_wrapper): New. A wrapper for sm_prog_1. Call
	check_default () before calling sm_prog_1 (). Define it as
	sm_prog_1_wrapper if HAVE_TCP_WRAPPER is defined.

1 files changed, 256 insertions, 0 deletions

diff --git a/support/misc/tcpwrapper.c b/support/misc/tcpwrapper.c
new file mode 100644
index 0000000..498a829
--- /dev/null
+++ b/support/misc/tcpwrapper.c
@@ -0,0 +1,256 @@
+/* This is copied from portmap 4.0-29 in RedHat. */
+
+ /*
+  * pmap_check - additional portmap security.
+  * 
+  * Always reject non-local requests to update the portmapper tables.
+  * 
+  * Refuse to forward mount requests to the nfs mount daemon. Otherwise, the
+  * requests would appear to come from the local system, and nfs export
+  * restrictions could be bypassed.
+  * 
+  * Refuse to forward requests to the nfsd process.
+  * 
+  * Refuse to forward requests to NIS (YP) daemons; The only exception is the
+  * YPPROC_DOMAIN_NONACK broadcast rpc call that is used to establish initial
+  * contact with the NIS server.
+  * 
+  * Always allocate an unprivileged port when forwarding a request.
+  * 
+  * If compiled with -DCHECK_PORT, require that requests to register or
+  * unregister a privileged port come from a privileged port. This makes it
+  * more difficult to replace a critical service by a trojan.
+  * 
+  * If compiled with -DHOSTS_ACCESS, reject requests from hosts that are not
+  * authorized by the /etc/hosts.{allow,deny} files. The local system is
+  * always treated as an authorized host. The access control tables are never
+  * consulted for requests from the local system, and are always consulted
+  * for requests from other hosts. Access control is based on IP addresses
+  * only; attempts to map an address to a host name might cause the
+  * portmapper to hang.
+  * 
+  * Author: Wietse Venema (wietse@wzv.win.tue.nl), dept. of Mathematics and
+  * Computing Science, Eindhoven University of Technology, The Netherlands.
+  */
+
+#include "tcpwrapper.h"
+
+#include <unistd.h>
+#include <string.h>
+#include <rpc/rpc.h>
+#include <rpc/pmap_prot.h>
+#include <syslog.h>
+#include <netdb.h>
+#include <pwd.h>
+#include <sys/types.h>
+#include <sys/signal.h>
+#ifdef SYSV40
+#include <netinet/in.h>
+#include <rpc/rpcent.h>
+#endif
+
+static void logit();
+static void toggle_verboselog();
+int     verboselog = 0;
+int     allow_severity = LOG_INFO;
+int     deny_severity = LOG_WARNING;
+
+/* A handful of macros for "readability". */
+
+/* coming from libwrap.a (tcp_wrappers) */
+extern int hosts_ctl(char *daemon, char *name, char *addr, char *user);
+
+#define	legal_port(a,p) \
+  (ntohs((a)->sin_port) < IPPORT_RESERVED || (p) >= IPPORT_RESERVED)
+
+#define log_bad_port(addr, proc, prog) \
+  logit(deny_severity, addr, proc, prog, ": request from unprivileged port")
+
+#define log_bad_host(addr, proc, prog) \
+  logit(deny_severity, addr, proc, prog, ": request from unauthorized host")
+
+#define log_bad_owner(addr, proc, prog) \
+  logit(deny_severity, addr, proc, prog, ": request from non-local host")
+
+#define	log_no_forward(addr, proc, prog) \
+  logit(deny_severity, addr, proc, prog, ": request not forwarded")
+
+#define log_client(addr, proc, prog) \
+  logit(allow_severity, addr, proc, prog, "")
+
+int
+good_client(daemon, addr)
+char *daemon;
+struct sockaddr_in *addr;
+{
+    struct hostent *hp;
+    char **sp;
+    char *tmpname;
+
+    /* Check the IP address first. */
+    if (hosts_ctl(daemon, "", inet_ntoa(addr->sin_addr), ""))
+	return 1;
+
+    /* Check the hostname. */
+    hp = gethostbyaddr ((const char *) &(addr->sin_addr),
+			sizeof (addr->sin_addr), AF_INET);
+
+    if (!hp)
+	return 0;
+
+    /* must make sure the hostent is authorative. */
+    tmpname = alloca (strlen (hp->h_name) + 1);
+    strcpy (tmpname, hp->h_name);
+    hp = gethostbyname(tmpname);
+    if (hp) {
+	/* now make sure the "addr->sin_addr" is on the list */
+	for (sp = hp->h_addr_list ; *sp ; sp++) {
+	    if (memcmp(*sp, &(addr->sin_addr), hp->h_length)==0)
+		break;
+	}
+	if (!*sp)
+	    /* it was a FAKE. */
+	    return 0;
+    }
+    else
+	   /* never heard of it. misconfigured DNS? */
+	   return 0;
+
+   /* Check the official name first. */
+   if (hosts_ctl(daemon, "", hp->h_name, ""))
+	return 1;
+
+   /* Check aliases. */
+   for (sp = hp->h_aliases; *sp ; sp++) {
+	if (hosts_ctl(daemon, "", *sp, ""))
+	    return 1;
+   }
+
+   /* No match */
+   return 0;
+}
+
+/* check_startup - additional startup code */
+
+void    check_startup()
+{
+
+    /*
+     * Give up root privileges so that we can never allocate a privileged
+     * port when forwarding an rpc request.
+     *
+     * Fix 8/3/00 Philipp Knirsch: First lookup our rpc user. If we find it,
+     * switch to that uid, otherwise simply resue the old bin user and print
+     * out a warning in syslog.
+     */
+
+    struct passwd *pwent;
+
+    pwent = getpwnam("rpc");
+    if (pwent == NULL) {
+        syslog(LOG_WARNING, "user rpc not found, reverting to user bin");
+        if (setuid(1) == -1) {
+            syslog(LOG_ERR, "setuid(1) failed: %m");
+            exit(1);
+        }
+    }
+    else {
+        if (setuid(pwent->pw_uid) == -1) {
+            syslog(LOG_WARNING, "setuid() to rpc user failed: %m");
+            if (setuid(1) == -1) {
+                syslog(LOG_ERR, "setuid(1) failed: %m");
+                exit(1);
+            }
+        }
+    }
+
+    (void) signal(SIGINT, toggle_verboselog);
+}
+
+/* check_default - additional checks for NULL, DUMP, GETPORT and unknown */
+
+int
+check_default(daemon, addr, proc, prog)
+char *daemon;
+struct sockaddr_in *addr;
+u_long  proc;
+u_long  prog;
+{
+    if (!(from_local(addr) || good_client(daemon, addr))) {
+	log_bad_host(addr, proc, prog);
+	return (FALSE);
+    }
+    if (verboselog)
+	log_client(addr, proc, prog);
+    return (TRUE);
+}
+
+/* check_privileged_port - additional checks for privileged-port updates */
+int
+check_privileged_port(addr, proc, prog, port)
+struct sockaddr_in *addr;
+u_long  proc;
+u_long  prog;
+u_long  port;
+{
+#ifdef CHECK_PORT
+    if (!legal_port(addr, port)) {
+	log_bad_port(addr, proc, prog);
+	return (FALSE);
+    }
+#endif
+    return (TRUE);
+}
+
+/* toggle_verboselog - toggle verbose logging flag */
+
+static void toggle_verboselog(sig)
+int     sig;
+{
+    (void) signal(sig, toggle_verboselog);
+    verboselog = !verboselog;
+}
+
+/* logit - report events of interest via the syslog daemon */
+
+static void logit(severity, addr, procnum, prognum, text)
+int     severity;
+struct sockaddr_in *addr;
+u_long  procnum;
+u_long  prognum;
+char   *text;
+{
+    char   *procname;
+    char    procbuf[4 * sizeof(u_long)];
+    char   *progname;
+    char    progbuf[4 * sizeof(u_long)];
+    struct rpcent *rpc;
+
+    /*
+     * Fork off a process or the portmap daemon might hang while
+     * getrpcbynumber() or syslog() does its thing.
+     */
+
+    if (fork() == 0) {
+
+	/* Try to map program number to name. */
+
+	if (prognum == 0) {
+	    progname = "";
+	} else if ((rpc = getrpcbynumber((int) prognum))) {
+	    progname = rpc->r_name;
+	} else {
+	    sprintf(progname = progbuf, "%lu", prognum);
+	}
+
+	/* Try to map procedure number to name. */
+
+	sprintf(procname = procbuf, "%lu", (u_long) procnum);
+
+	/* Write syslog record. */
+
+	syslog(severity, "connect from %s to %s(%s)%s",
+	       inet_ntoa(addr->sin_addr), procname, progname, text);
+	exit(0);
+    }
+}