[PATCH 3/3] nfs-utils: Enabling TCP wrappers

[Steve Dickson <SteveD@redhat.com>]

commit e1956712782b4bb7b4369420bfada972e5bc4398
Author: Steve Dickson <steved@redhat.com>
Date:   Mon Dec 15 11:44:51 2008 -0500

    To ensure the hash table of clients has valid
    access rights, check the modification times on
    both access files. If one of them have change,
    update the hash entry instead of creating a
    new entry.
    
    Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/support/misc/tcpwrapper.c b/support/misc/tcpwrapper.c
index f7fd3a9..c0c5af7 100644
--- a/support/misc/tcpwrapper.c
+++ b/support/misc/tcpwrapper.c
@@ -45,6 +45,9 @@
 #include <sys/types.h>
 #include <sys/signal.h>
 #include <sys/queue.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
 #ifdef SYSV40
 #include <netinet/in.h>
 #include <rpc/rpcent.h>
@@ -246,6 +249,33 @@ void    check_startup(void)
     (void) signal(SIGINT, toggle_verboselog);
 }
 
+/* check_files - check to see if either access files have changed */
+
+int check_files()
+{
+	static time_t allow_mtime, deny_mtime;
+	struct stat astat, dstat;
+	int changed = 0;
+
+	if (stat("/etc/hosts.allow", &astat) < 0)
+		astat.st_mtime = 0;
+	if (stat("/etc/hosts.deny", &dstat) < 0)
+		dstat.st_mtime = 0;
+
+	if(!astat.st_mtime || !dstat.st_mtime)
+		return changed;
+
+	if (astat.st_mtime != allow_mtime)
+		changed = 1;
+	else if (dstat.st_mtime != deny_mtime)
+		changed = 1;
+
+	allow_mtime = astat.st_mtime;
+	deny_mtime = dstat.st_mtime;
+
+	return changed;
+}
+
 /* check_default - additional checks for NULL, DUMP, GETPORT and unknown */
 
 int
@@ -256,20 +286,27 @@ u_long  proc;
 u_long  prog;
 {
 	haccess_t *acc = NULL;
+	int changed = check_files();
 
 	acc = haccess_lookup(addr, proc, prog);
-	if (acc)
+	if (acc && changed == 0)
 		return (acc->access);
 
 	if (!(from_local(addr) || good_client(daemon, addr))) {
 		log_bad_host(addr, proc, prog);
-		haccess_add(addr, proc, prog, FALSE);
+		if (acc)
+			acc->access = FALSE;
+		else 
+			haccess_add(addr, proc, prog, FALSE);
 		return (FALSE);
 	}
 	if (verboselog)
 		log_client(addr, proc, prog);
 
-	haccess_add(addr, proc, prog, TRUE);
+	if (acc)
+		acc->access = TRUE;
+	else 
+		haccess_add(addr, proc, prog, TRUE);
     return (TRUE);
 }