1 /* $NetBSD: utmp_update.c,v 1.13 2015/04/26 08:56:19 mlelstv 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>
51 static __dead2 __printflike(2, 3) void
52 logerr(int e, const char *fmt, ...)
58 (void)asprintf(&s, "%s (%s)", fmt, strerror(e));
64 vsyslog(LOG_ERR, fmt, sap);
71 main(int argc, char *argv[])
86 (void)fprintf(stderr, "Usage: %s <vis-utmpx-entry>\n",
91 openlog(getprogname(), LOG_PID | LOG_NDELAY, LOG_AUTH);
92 if (seteuid(ruid) == -1)
93 logerr(errno, "Can't setuid %ld", (long)ruid);
95 len = strlen(argv[1]);
97 if (len > sizeof(*utx) * 4 + 1 || len < sizeof(*utx))
98 logerr(0, "Bad argument size %zu", len);
100 if ((utx = malloc(len+1)) == NULL)
101 logerr(errno, "Can't allocate %zu", len+1);
103 res = strunvis((char *)utx, argv[1]);
104 if (res != (int)sizeof(*utx))
105 logerr(0, "Decoding error %s %d != %zu", argv[1], res,
108 switch (utx->ut_type) {
113 logerr(0, "Invalid utmpx type %hd", utx->ut_type);
117 if ((pwd = getpwuid(ruid)) == NULL)
118 logerr(0, "User %ld does not exist in password"
119 " database", (long)ruid);
121 if (strcmp(pwd->pw_name, utx->ut_name) != 0)
122 logerr(0, "Current user `%s' does not match "
123 "`%s' in utmpx entry", pwd->pw_name, utx->ut_name);
126 (void)snprintf(tty, sizeof(tty), "%s%s", _PATH_DEV, utx->ut_line);
127 fd = open(tty, O_RDONLY|O_NONBLOCK, 0);
129 if (fstat(fd, &st) == -1)
130 logerr(errno, "Cannot stat `%s'", tty);
131 if (ruid != 0 && st.st_uid != ruid)
132 logerr(0, "%s: Is not owned by you", tty);
134 logerr(0, "%s: Not a tty device", tty);
136 if (access(tty, W_OK|R_OK) == -1)
137 logerr(errno, "Can't access `%s'", tty);
139 struct utmpx utold, *utoldp;
143 * A daemon like ftpd that does not use a tty line?
144 * We only allow it to kill its own existing entries
146 if (utx->ut_type != DEAD_PROCESS)
147 logerr(errno, "Cannot open `%s'", tty);
149 (void)memcpy(utold.ut_line, utx->ut_line, sizeof(utx->ut_line));
150 if ((utoldp = getutxline(&utold)) == NULL)
151 logerr(0, "Cannot find existing entry for `%s'",
153 if (utoldp->ut_pid != (ppid = getppid()))
154 logerr(0, "Cannot modify entry for `%s' "
155 "utmpx pid %ld != parent %ld", tty,
156 (long)utoldp->ut_pid, (long)ppid);
159 if (seteuid(euid) == 1)
160 logerr(errno, "Can't setuid %ld", (long)euid);
161 if (pututxline(utx) == NULL)
162 logerr(errno, "Cannot update utmpx entry");