[src/trunk]: src/usr.sbin/rwhod Add -u option: rwhod will drop privledges and...

[tsarna <tsarna%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a41f2816e660
branches:  trunk
changeset: 584284:a41f2816e660
user:      tsarna <tsarna%NetBSD.org@localhost>
date:      Mon Sep 12 16:13:13 2005 +0000

description:
Add -u option: rwhod will drop privledges and become the given user.

reviewed by jwise

diffstat:

 usr.sbin/rwhod/rwhod.8 |   6 ++++--
 usr.sbin/rwhod/rwhod.c |  50 +++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 51 insertions(+), 5 deletions(-)

diffs (135 lines):

diff -r 179cb4035e90 -r a41f2816e660 usr.sbin/rwhod/rwhod.8
--- a/usr.sbin/rwhod/rwhod.8    Mon Sep 12 16:10:11 2005 +0000
+++ b/usr.sbin/rwhod/rwhod.8    Mon Sep 12 16:13:13 2005 +0000
@@ -26,7 +26,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     from: @(#)rwhod.8      8.2 (Berkeley) 12/11/93
-.\"    $NetBSD: rwhod.8,v 1.18 2005/09/11 23:45:04 wiz Exp $
+.\"    $NetBSD: rwhod.8,v 1.19 2005/09/12 16:13:13 tsarna Exp $
 .\"
 .Dd August 9, 2005
 .Dt RWHOD 8
@@ -47,7 +47,7 @@
 .Em broadcast
 messages on a network.
 .Pp
-The following option is available:
+The following options are available:
 .Bl -tag -width XXXXXXXXXXX
 .It Fl i Ar interval
 Allows for the broadcast interval to be changed from the default 3 minutes.
@@ -61,6 +61,8 @@
 because higher values will cause
 .Xr ruptime 1
 to mark the host as being down.
+.It Fl u Ar user
+drop privledges and become the named user.
 .El
 .Pp
 .Nm
diff -r 179cb4035e90 -r a41f2816e660 usr.sbin/rwhod/rwhod.c
--- a/usr.sbin/rwhod/rwhod.c    Mon Sep 12 16:10:11 2005 +0000
+++ b/usr.sbin/rwhod/rwhod.c    Mon Sep 12 16:13:13 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rwhod.c,v 1.30 2005/07/05 02:46:36 christos Exp $      */
+/*     $NetBSD: rwhod.c,v 1.31 2005/09/12 16:13:13 tsarna Exp $        */
 
 /*
  * Copyright (c) 1983, 1993
@@ -39,7 +39,7 @@
 #if 0
 static char sccsid[] = "@(#)rwhod.c    8.1 (Berkeley) 6/6/93";
 #else
-__RCSID("$NetBSD: rwhod.c,v 1.30 2005/07/05 02:46:36 christos Exp $");
+__RCSID("$NetBSD: rwhod.c,v 1.31 2005/09/12 16:13:13 tsarna Exp $");
 #endif
 #endif /* not lint */
 
@@ -108,6 +108,7 @@
 static void     handleread(int);
 static void     quit(const char *);
 static void     rt_xaddrs(void *, void *, struct rt_addrinfo *);
+static int      drop_privs(char *);
 static void     usage(void) __attribute__((__noreturn__));
 static int      verify(const char *);
 #ifdef DEBUG
@@ -128,13 +129,14 @@
        struct sockaddr_in sasin;
        struct pollfd pfd[1];
        struct timeval delta, next, now;
+       char *newuser = NULL;
 
        setprogname(argv[0]);
 
        if (getuid())
                errx(EXIT_FAILURE, "not super user");
 
-       while ((ch = getopt(argc, argv, "i:")) != -1) {
+       while ((ch = getopt(argc, argv, "i:u:")) != -1) {
                switch (ch) {
                case 'i':
                        time_interval = (int)strtol(optarg, &ep, 10);
@@ -160,6 +162,11 @@
                                errx(1, "Interval cannot be greater than"
                                    " %d minutes", MAX_INTERVAL / 60);
                        break;
+
+               case 'u':
+                       newuser = optarg;
+                       break;
+                       
                default:
                        usage();        
                }
@@ -206,6 +213,10 @@
        if (!configure(s))
                exit(EXIT_FAILURE);
 
+       if (newuser)
+               if (!drop_privs(newuser))
+                       exit(EXIT_FAILURE);
+
        send_host_information(s);
        delta.tv_sec = time_interval;
        delta.tv_usec = 0;
@@ -595,6 +606,39 @@
 }
 #endif
 
+static int
+drop_privs(char *newuser)
+{
+       struct passwd *pw;
+       gid_t gidset[1];
+       
+       pw = getpwnam(newuser);
+       if (pw == NULL) {
+               syslog(LOG_ERR, "no user %.100s", newuser);
+               return 0;
+       }
+
+       endpwent();     
+
+       gidset[0] = pw->pw_gid;
+       if (setgroups(1, gidset) == -1) {
+               syslog(LOG_ERR, "setgroups: %m");
+               return 0;
+       }
+
+       if (setgid(pw->pw_gid) == -1) {
+               syslog(LOG_ERR, "setgid: %m");
+               return 0;
+       }
+
+       if (setuid(pw->pw_uid) == -1) {
+               syslog(LOG_ERR, "setuid: %m");
+               return 0;
+       }
+
+       return 1;
+}
+
 static void
 usage(void)
 {