Add a utility, utxrm(8).

Most of the ports I broke when I imported utmpx, were simple management
utilities for the utmp database, allowing you to add/remove entries
manually.

Add a small tool called utxrm(8), which allows you to remove an entry
from the utmpx database by hand. This is useful when a login daemon
crashes or fails to remove the entry during shutdown.

lib/libc/gen/getutxent.3

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd January 8, 2010
+.Dd February 19, 2011
 .Dt GETUTXENT 3
 .Os
 .Sh NAME
@@ -424,7 +424,8 @@ The file format is invalid.
 .Xr gettimeofday 2 ,
 .Xr tty 4 ,
 .Xr ac 8 ,
-.Xr newsyslog 8
+.Xr newsyslog 8 ,
+.Xr utxrm 8
 .Sh STANDARDS
 The
 .Fn endutxent ,

usr.sbin/Makefile

@@ -89,6 +89,7 @@ SUBDIR= adduser \
 	trpt \
 	tzsetup \
 	ugidfw \
+	utxrm \
 	vipw \
 	wake \
 	watch \

usr.sbin/utxrm/Makefile

@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+PROG=	utxrm
+MAN=	utxrm.8
+
+.include <bsd.prog.mk>

usr.sbin/utxrm/utxrm.8

@@ -0,0 +1,72 @@
+.\" Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd February 19, 2011
+.Dt UTXRM 8
+.Os
+.Sh NAME
+.Nm utxrm
+.Nd remove sessions from the user accounting database
+.Sh SYNOPSIS
+.Nm
+.Ar identifier
+.Ar ...
+.Sh DESCRIPTION
+The
+.Nm
+utility can be used to remove stale sessions from the user accounting
+database, by referring to their
+.Ar identifier .
+Stale sessions can occur if a login service exits prematurely or fails
+to remove the session from the accounting database.
+.Pp
+Utilities such as
+.Xr w 1
+will not display the identifier corresponding with a login session,
+since its value is typically only of use by the process managing the
+record.
+The following command can be used to obtain all records from the user
+accounting database's active session table, including its identifiers:
+.Pp
+.Dl getent utmpx active
+.Pp
+Identifiers can either be supplied in hexadecimal form as displayed by
+.Xr getent 1 ,
+or as a string if the identifier allows such a representation.
+.Pp
+Because this utility requires write-access to the user accounting
+database, its use is limited to the super-user.
+.Sh SEE ALSO
+.Xr getent 1 ,
+.Xr w 1 ,
+.Xr pututxline 3 .
+.Sh HISTORY
+The
+.Nm
+utility appeared in
+.Fx 9.0 .
+.Sh AUTHORS
+.An Ed Schouten Aq ed@FreeBSD.org

usr.sbin/utxrm/utxrm.c

@@ -0,0 +1,84 @@
+/*-
+ * Copyright (c) 2011 Ed Schouten <ed@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/time.h>
+#include <errno.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <utmpx.h>
+
+static int
+b16_pton(const char *in, char *out, size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len * 2; i++)
+		if (!isxdigit((unsigned char)in[i]))
+			return (1);
+	for (i = 0; i < len; i++)
+		sscanf(&in[i * 2], "%02hhx", &out[i]);
+	return (0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct utmpx utx = { .ut_type = DEAD_PROCESS };
+	size_t len;
+	int i, ret = 0;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: utxrm identifier ...\n");
+		return (1);
+	}
+
+	gettimeofday(&utx.ut_tv, NULL);
+	for (i = 1; i < argc; i++) {
+		len = strlen(argv[i]);
+		if (len <= sizeof(utx.ut_id)) {
+			/* Identifier as string. */
+			strncpy(utx.ut_id, argv[i], sizeof(utx.ut_id));
+		} else if (len != sizeof(utx.ut_id) * 2 ||
+		    b16_pton(argv[i], utx.ut_id, sizeof(utx.ut_id)) != 0) {
+			/* Also not hexadecimal. */
+			fprintf(stderr, "%s: Invalid identifier format\n",
+			    argv[i]);
+			ret = 1;
+			continue;
+		}
+
+		/* Zap the entry. */
+		if (pututxline(&utx) == NULL) {
+			perror(argv[i]);
+			ret = 1;
+		}
+	}
+	return (ret);
+}