From 879c7d27302e0fb0654529de4b88f210ee11b022 Mon Sep 17 00:00:00 2001 From: ed Date: Thu, 3 Dec 2009 15:48:24 +0000 Subject: Add a new library: libulog. One of the things I really want to do, is to get rid of the limitations of our current utmp(5) mechanism: - It only allows 8 byte TTY device names. - The hostname only allows 16 bytes of storage. I'm not a big fan of , but I think we should at least try to add parts of it. Unfortunately we cannot implement , because we miss various fields, such as ut_id, ut_pid, etc. The API provided by libulog shares some similarities with , so it shouldn't be too hard to port these applications eventually. In most simple cases, it should just be a matter of removing the ulog_ prefix everywhere. As a bonus, it also implements a function called ulog_login_pseudo(), which allows unprivileged applications to write log entries, provided they have a valid file descriptor to a pseudo-terminal master device. libulog will allow a smoother transition to a new file format by adding a library interface to deal with utmp/wtmp/lastlog files. I initially thought about adding the functionality to libutil, but because I'm not planning on keeping this library around forever, we'd better keep it separated. Next items on the todo list: 1. Port applications in the base system (and ports) to libulog, instead of letting them use . 2. Remove , implement and reimplement this library on top. 3. Port as many applications as possible back to . --- lib/libulog/ulog_login_pseudo.c | 93 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 lib/libulog/ulog_login_pseudo.c (limited to 'lib/libulog/ulog_login_pseudo.c') diff --git a/lib/libulog/ulog_login_pseudo.c b/lib/libulog/ulog_login_pseudo.c new file mode 100644 index 0000000..841a2db --- /dev/null +++ b/lib/libulog/ulog_login_pseudo.c @@ -0,0 +1,93 @@ +/*- + * Copyright (c) 2009 Ed Schouten + * 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 +__FBSDID("$FreeBSD$"); + +#include + +#include +#include +#include +#include +#include + +#include "ulog_internal.h" + +#define _PATH_ULOG_HELPER "/usr/libexec/ulog-helper" + +/* + * Registering login sessions. + */ + +static void +ulog_exec_helper(int fd, char const * const argv[]) +{ + sigset_t oblock, nblock; + pid_t pid, wpid; + int status; + + /* Block SIGCHLD. */ + sigemptyset(&nblock); + sigaddset(&nblock, SIGCHLD); + sigprocmask(SIG_BLOCK, &nblock, &oblock); + + switch (pid = fork()) { + case -1: + break; + case 0: + /* Execute helper program. */ + if (dup2(fd, STDIN_FILENO) == -1) + exit(EX_UNAVAILABLE); + sigprocmask(SIG_SETMASK, &oblock, NULL); + execv(_PATH_ULOG_HELPER, __DECONST(char * const *, argv)); + exit(EX_UNAVAILABLE); + default: + /* Wait for helper to finish. */ + do { + wpid = waitpid(pid, &status, 0); + } while (wpid == -1 && errno == EINTR); + break; + } + + sigprocmask(SIG_SETMASK, &oblock, NULL); +} + +void +ulog_login_pseudo(int fd, const char *host) +{ + char const * const args[4] = { "ulog-helper", "login", host, NULL }; + + ulog_exec_helper(fd, args); +} + +void +ulog_logout_pseudo(int fd) +{ + char const * const args[3] = { "ulog-helper", "logout", NULL }; + + ulog_exec_helper(fd, args); +} -- cgit v1.1