1 /* $NetBSD: utmp_update.c,v 1.8 2008/04/28 20:23:04 martin Exp $ */
4 * Copyright (c) 2002 The NetBSD Foundation, Inc.
7 * This code is derived from software contributed to The NetBSD Foundation
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
31 #include <sys/cdefs.h>
33 #include <sys/types.h>
34 #include <sys/param.h>
49 main(int argc, char *argv[])
62 if (seteuid(ruid) == -1)
66 (void)fprintf(stderr, "Usage: %s <vis-utmpx-entry>\n",
71 len = strlen(argv[1]);
73 if (len > sizeof(*utx) * 4 + 1 || len < sizeof(*utx))
74 errx(1, "Bad argument");
76 if ((utx = malloc(len)) == NULL)
79 res = strunvis((char *)utx, argv[1]);
80 if (res != (int)sizeof(*utx))
81 errx(1, "Decoding error %s %d != %zu", argv[1], res, sizeof(*utx));
83 switch (utx->ut_type) {
88 errx(1, "Invalid utmpx type %d", (int)utx->ut_type);
92 if ((pwd = getpwuid(ruid)) == NULL)
93 errx(1, "User %lu does not exist in password database",
96 if (strcmp(pwd->pw_name, utx->ut_name) != 0)
97 errx(1, "Current user `%s' does not match "
98 "`%s' in utmpx entry", pwd->pw_name, utx->ut_name);
101 (void)snprintf(tty, sizeof(tty), "%s%s", _PATH_DEV, utx->ut_line);
102 fd = open(tty, O_RDONLY|O_NONBLOCK, 0);
104 if (fstat(fd, &st) == -1)
105 err(1, "Cannot stat `%s'", tty);
106 if (ruid != 0 && st.st_uid != ruid)
107 errx(1, "%s: Is not owned by you", tty);
109 errx(1, "%s: Not a tty device", tty);
111 if (access(tty, W_OK|R_OK) == -1)
114 struct utmpx utold, *utoldp;
116 * A daemon like ftpd that does not use a tty line?
117 * We only allow it to kill its own existing entries
119 if (utx->ut_type != DEAD_PROCESS)
120 err(1, "Cannot open `%s'", tty);
122 (void)memcpy(utold.ut_line, utx->ut_line, sizeof(utx->ut_line));
123 if ((utoldp = getutxline(&utold)) == NULL)
124 err(1, "Cannot find existing entry for `%s'",
126 if (utoldp->ut_pid != getppid())
127 err(1, "Cannot modify entry for `%s'", tty);
131 if (pututxline(utx) == NULL)
132 err(1, "Cannot update utmp entry");