diff options
Diffstat (limited to 'libexec/ulog-helper')
| -rw-r--r-- | libexec/ulog-helper/Makefile | 10 | ||||
| -rw-r--r-- | libexec/ulog-helper/Makefile.depend | 19 | ||||
| -rw-r--r-- | libexec/ulog-helper/ulog-helper.c | 99 |
3 files changed, 128 insertions, 0 deletions
diff --git a/libexec/ulog-helper/Makefile b/libexec/ulog-helper/Makefile new file mode 100644 index 000000000000..b763643fb5d9 --- /dev/null +++ b/libexec/ulog-helper/Makefile @@ -0,0 +1,10 @@ +# $FreeBSD$ + +PROG= ulog-helper +BINOWN= root +BINMODE=4555 +MAN= + +LIBADD= ulog + +.include <bsd.prog.mk> diff --git a/libexec/ulog-helper/Makefile.depend b/libexec/ulog-helper/Makefile.depend new file mode 100644 index 000000000000..e9d5b7d57150 --- /dev/null +++ b/libexec/ulog-helper/Makefile.depend @@ -0,0 +1,19 @@ +# $FreeBSD$ +# Autogenerated - do NOT edit! + +DIRDEPS = \ + gnu/lib/csu \ + include \ + include/xlocale \ + lib/${CSU_DIR} \ + lib/libc \ + lib/libcompiler_rt \ + lib/libmd \ + lib/libulog \ + + +.include <dirdeps.mk> + +.if ${DEP_RELDIR} == ${_DEP_RELDIR} +# local dependencies - needed for -jN in clean tree +.endif diff --git a/libexec/ulog-helper/ulog-helper.c b/libexec/ulog-helper/ulog-helper.c new file mode 100644 index 000000000000..3b525f4fe76e --- /dev/null +++ b/libexec/ulog-helper/ulog-helper.c @@ -0,0 +1,99 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <pwd.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <sysexits.h> +#include <ulog.h> + +/* + * This setuid helper utility writes user login records to disk. + * Unprivileged processes are not capable of writing records to utmpx, + * but we do want to allow this for pseudo-terminals. Because a file + * descriptor to a pseudo-terminal master device can only be obtained by + * processes using the pseudo-terminal, we expect such a descriptor on + * stdin. + * + * It uses the real user ID of the calling process to determine the + * username. It does allow users to log arbitrary hostnames. + */ + +static const char * +get_username(void) +{ + const struct passwd *pw; + const char *login; + uid_t uid; + + /* + * Attempt to determine the username corresponding to this login + * session. First, validate the results of getlogin() against + * the password database. If getlogin() returns invalid data, + * return an arbitrary username corresponding to this uid. + */ + uid = getuid(); + if ((login = getlogin()) != NULL && (pw = getpwnam(login)) != NULL && + pw->pw_uid == uid) + return (login); + if ((pw = getpwuid(uid)) != NULL) + return (pw->pw_name); + return (NULL); +} + +int +main(int argc, char *argv[]) +{ + const char *line, *user, *host; + + /* Device line name. */ + if ((line = ptsname(STDIN_FILENO)) == NULL) + return (EX_USAGE); + + if ((argc == 2 || argc == 3) && strcmp(argv[1], "login") == 0) { + /* Username. */ + user = get_username(); + if (user == NULL) + return (EX_OSERR); + + /* Hostname. */ + host = argc == 3 ? argv[2] : NULL; + + ulog_login(line, user, host); + return (EX_OK); + } else if (argc == 2 && strcmp(argv[1], "logout") == 0) { + ulog_logout(line); + return (EX_OK); + } + + return (EX_USAGE); +} |