1de7b4b805
Mainly focus on files that use BSD 2-Clause license, however the tool I was using misidentified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. No functional change intended.
565 lines
14 KiB
C
565 lines
14 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Berkeley Software Design Inc's name may not be used to endorse or
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* promote products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* From BSDI: daemon.c,v 1.2 1996/08/15 01:11:09 jch Exp
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/mman.h>
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#include <sys/wait.h>
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#include <fcntl.h>
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#include <err.h>
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#include <errno.h>
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#include <libutil.h>
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#include <login_cap.h>
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#include <pwd.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <strings.h>
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#define SYSLOG_NAMES
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#include <syslog.h>
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#include <time.h>
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#include <assert.h>
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#define LBUF_SIZE 4096
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struct log_params {
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int dosyslog;
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int logpri;
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int noclose;
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int outfd;
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};
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static void restrict_process(const char *);
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static void handle_term(int);
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static void handle_chld(int);
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static int listen_child(int, struct log_params *);
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static int get_log_mapping(const char *, const CODE *);
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static void open_pid_files(const char *, const char *, struct pidfh **,
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struct pidfh **);
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static void do_output(const unsigned char *, size_t, struct log_params *);
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static void daemon_sleep(time_t, long);
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static void usage(void);
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static volatile sig_atomic_t terminate = 0, child_gone = 0, pid = 0;
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int
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main(int argc, char *argv[])
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{
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const char *pidfile, *ppidfile, *title, *user, *outfn, *logtag;
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int ch, nochdir, noclose, restart, dosyslog, child_eof;
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sigset_t mask_susp, mask_orig, mask_read, mask_term;
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struct log_params logpar;
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int pfd[2] = { -1, -1 }, outfd = -1;
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int stdmask, logpri, logfac;
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struct pidfh *ppfh, *pfh;
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char *p;
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memset(&logpar, 0, sizeof(logpar));
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stdmask = STDOUT_FILENO | STDERR_FILENO;
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ppidfile = pidfile = user = NULL;
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nochdir = noclose = 1;
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logpri = LOG_NOTICE;
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logfac = LOG_DAEMON;
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logtag = "daemon";
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restart = 0;
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dosyslog = 0;
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outfn = NULL;
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title = NULL;
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while ((ch = getopt(argc, argv, "cfSp:P:ru:o:s:l:t:l:m:T:")) != -1) {
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switch (ch) {
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case 'c':
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nochdir = 0;
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break;
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case 'f':
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noclose = 0;
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break;
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case 'l':
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logfac = get_log_mapping(optarg, facilitynames);
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if (logfac == -1)
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errx(5, "unrecognized syslog facility");
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dosyslog = 1;
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break;
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case 'm':
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stdmask = strtol(optarg, &p, 10);
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if (p == optarg || stdmask < 0 || stdmask > 3)
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errx(6, "unrecognized listening mask");
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break;
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case 'o':
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outfn = optarg;
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break;
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case 'p':
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pidfile = optarg;
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break;
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case 'P':
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ppidfile = optarg;
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break;
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case 'r':
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restart = 1;
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break;
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case 's':
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logpri = get_log_mapping(optarg, prioritynames);
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if (logpri == -1)
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errx(4, "unrecognized syslog priority");
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dosyslog = 1;
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break;
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case 'S':
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dosyslog = 1;
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break;
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case 't':
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title = optarg;
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break;
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case 'T':
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logtag = optarg;
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dosyslog = 1;
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break;
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case 'u':
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user = optarg;
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break;
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default:
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usage();
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}
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}
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argc -= optind;
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argv += optind;
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if (argc == 0)
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usage();
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if (!title)
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title = argv[0];
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if (outfn) {
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outfd = open(outfn, O_CREAT | O_WRONLY | O_APPEND | O_CLOEXEC, 0600);
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if (outfd == -1)
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err(7, "open");
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}
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if (dosyslog)
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openlog(logtag, LOG_PID | LOG_NDELAY, logfac);
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ppfh = pfh = NULL;
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/*
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* Try to open the pidfile before calling daemon(3),
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* to be able to report the error intelligently
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*/
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open_pid_files(pidfile, ppidfile, &pfh, &ppfh);
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if (daemon(nochdir, noclose) == -1) {
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warn("daemon");
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goto exit;
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}
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/* Write out parent pidfile if needed. */
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pidfile_write(ppfh);
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/*
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* If the pidfile or restart option is specified the daemon
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* executes the command in a forked process and wait on child
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* exit to remove the pidfile or restart the command. Normally
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* we don't want the monitoring daemon to be terminated
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* leaving the running process and the stale pidfile, so we
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* catch SIGTERM and forward it to the children expecting to
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* get SIGCHLD eventually. We also must fork() to obtain a
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* readable pipe with the child for writing to a log file
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* and syslog.
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*/
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pid = -1;
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if (pidfile || ppidfile || restart || outfd != -1 || dosyslog) {
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struct sigaction act_term, act_chld;
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/* Avoid PID racing with SIGCHLD and SIGTERM. */
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memset(&act_term, 0, sizeof(act_term));
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act_term.sa_handler = handle_term;
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sigemptyset(&act_term.sa_mask);
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sigaddset(&act_term.sa_mask, SIGCHLD);
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memset(&act_chld, 0, sizeof(act_chld));
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act_chld.sa_handler = handle_chld;
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sigemptyset(&act_chld.sa_mask);
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sigaddset(&act_chld.sa_mask, SIGTERM);
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/* Block these when avoiding racing before sigsuspend(). */
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sigemptyset(&mask_susp);
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sigaddset(&mask_susp, SIGTERM);
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sigaddset(&mask_susp, SIGCHLD);
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/* Block SIGTERM when we lack a valid child PID. */
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sigemptyset(&mask_term);
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sigaddset(&mask_term, SIGTERM);
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/*
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* When reading, we wish to avoid SIGCHLD. SIGTERM
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* has to be caught, otherwise we'll be stuck until
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* the read() returns - if it returns.
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*/
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sigemptyset(&mask_read);
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sigaddset(&mask_read, SIGCHLD);
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/* Block SIGTERM to avoid racing until we have forked. */
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if (sigprocmask(SIG_BLOCK, &mask_term, &mask_orig)) {
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warn("sigprocmask");
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goto exit;
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}
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if (sigaction(SIGTERM, &act_term, NULL) == -1) {
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warn("sigaction");
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goto exit;
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}
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if (sigaction(SIGCHLD, &act_chld, NULL) == -1) {
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warn("sigaction");
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goto exit;
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}
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/*
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* Try to protect against pageout kill. Ignore the
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* error, madvise(2) will fail only if a process does
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* not have superuser privileges.
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*/
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(void)madvise(NULL, 0, MADV_PROTECT);
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logpar.outfd = outfd;
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logpar.dosyslog = dosyslog;
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logpar.logpri = logpri;
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logpar.noclose = noclose;
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restart:
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if (pipe(pfd))
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err(1, "pipe");
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/*
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* Spawn a child to exec the command.
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*/
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child_gone = 0;
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pid = fork();
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if (pid == -1) {
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warn("fork");
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goto exit;
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} else if (pid > 0) {
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/*
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* Unblock SIGTERM after we know we have a valid
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* child PID to signal.
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*/
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if (sigprocmask(SIG_UNBLOCK, &mask_term, NULL)) {
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warn("sigprocmask");
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goto exit;
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}
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close(pfd[1]);
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pfd[1] = -1;
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}
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}
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if (pid <= 0) {
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/* Now that we are the child, write out the pid. */
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pidfile_write(pfh);
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if (user != NULL)
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restrict_process(user);
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/*
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* When forking, the child gets the original sigmask,
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* and dup'd pipes.
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*/
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if (pid == 0) {
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close(pfd[0]);
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if (sigprocmask(SIG_SETMASK, &mask_orig, NULL))
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err(1, "sigprogmask");
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if (stdmask & STDERR_FILENO) {
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if (dup2(pfd[1], STDERR_FILENO) == -1)
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err(1, "dup2");
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}
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if (stdmask & STDOUT_FILENO) {
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if (dup2(pfd[1], STDOUT_FILENO) == -1)
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err(1, "dup2");
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}
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if (pfd[1] != STDERR_FILENO &&
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pfd[1] != STDOUT_FILENO)
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close(pfd[1]);
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}
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execvp(argv[0], argv);
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/*
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* execvp() failed -- report the error. The child is
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* now running, so the exit status doesn't matter.
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*/
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err(1, "%s", argv[0]);
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}
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setproctitle("%s[%d]", title, (int)pid);
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/*
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* As we have closed the write end of pipe for parent process,
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* we might detect the child's exit by reading EOF. The child
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* might have closed its stdout and stderr, so we must wait for
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* the SIGCHLD to ensure that the process is actually gone.
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*/
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child_eof = 0;
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for (;;) {
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/*
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* We block SIGCHLD when listening, but SIGTERM we accept
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* so the read() won't block if we wish to depart.
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*
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* Upon receiving SIGTERM, we have several options after
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* sending the SIGTERM to our child:
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* - read until EOF
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* - read until EOF but only for a while
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* - bail immediately
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*
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* We go for the third, as otherwise we have no guarantee
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* that we won't block indefinitely if the child refuses
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* to depart. To handle the second option, a different
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* approach would be needed (procctl()?)
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*/
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if (child_gone && child_eof) {
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break;
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} else if (terminate) {
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goto exit;
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} else if (!child_eof) {
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if (sigprocmask(SIG_BLOCK, &mask_read, NULL)) {
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warn("sigprocmask");
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goto exit;
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}
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child_eof = !listen_child(pfd[0], &logpar);
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if (sigprocmask(SIG_UNBLOCK, &mask_read, NULL)) {
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warn("sigprocmask");
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goto exit;
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}
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} else {
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if (sigprocmask(SIG_BLOCK, &mask_susp, NULL)) {
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warn("sigprocmask");
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goto exit;
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}
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while (!terminate && !child_gone)
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sigsuspend(&mask_orig);
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if (sigprocmask(SIG_UNBLOCK, &mask_susp, NULL)) {
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warn("sigprocmask");
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goto exit;
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}
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}
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}
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if (sigprocmask(SIG_BLOCK, &mask_term, NULL)) {
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warn("sigprocmask");
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goto exit;
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}
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if (restart && !terminate) {
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daemon_sleep(1, 0);
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close(pfd[0]);
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pfd[0] = -1;
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goto restart;
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}
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exit:
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close(outfd);
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close(pfd[0]);
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close(pfd[1]);
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if (dosyslog)
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closelog();
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pidfile_remove(pfh);
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pidfile_remove(ppfh);
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exit(1); /* If daemon(3) succeeded exit status does not matter. */
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}
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static void
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daemon_sleep(time_t secs, long nsecs)
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{
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struct timespec ts = { secs, nsecs };
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while (nanosleep(&ts, &ts) == -1) {
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if (errno != EINTR)
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err(1, "nanosleep");
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}
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}
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static void
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open_pid_files(const char *pidfile, const char *ppidfile,
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struct pidfh **pfh, struct pidfh **ppfh)
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{
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pid_t fpid;
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int serrno;
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if (pidfile) {
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*pfh = pidfile_open(pidfile, 0600, &fpid);
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if (*pfh == NULL) {
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if (errno == EEXIST) {
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errx(3, "process already running, pid: %d",
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fpid);
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}
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err(2, "pidfile ``%s''", pidfile);
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}
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}
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/* Do the same for the actual daemon process. */
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if (ppidfile) {
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*ppfh = pidfile_open(ppidfile, 0600, &fpid);
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if (*ppfh == NULL) {
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serrno = errno;
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pidfile_remove(*pfh);
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errno = serrno;
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if (errno == EEXIST) {
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errx(3, "process already running, pid: %d",
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fpid);
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}
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err(2, "ppidfile ``%s''", ppidfile);
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}
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}
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}
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static int
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get_log_mapping(const char *str, const CODE *c)
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{
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const CODE *cp;
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for (cp = c; cp->c_name; cp++)
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if (strcmp(cp->c_name, str) == 0)
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return cp->c_val;
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return -1;
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}
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static void
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restrict_process(const char *user)
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{
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struct passwd *pw = NULL;
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pw = getpwnam(user);
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if (pw == NULL)
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errx(1, "unknown user: %s", user);
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if (setusercontext(NULL, pw, pw->pw_uid, LOGIN_SETALL) != 0)
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errx(1, "failed to set user environment");
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}
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/*
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* We try to collect whole lines terminated by '\n'. Otherwise we collect a
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* full buffer, and then output it.
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*
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* Return value of 0 is assumed to mean EOF or error, and 1 indicates to
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* continue reading.
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*/
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static int
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listen_child(int fd, struct log_params *logpar)
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{
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static unsigned char buf[LBUF_SIZE];
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static size_t bytes_read = 0;
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int rv;
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assert(logpar);
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assert(bytes_read < LBUF_SIZE - 1);
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rv = read(fd, buf + bytes_read, LBUF_SIZE - bytes_read - 1);
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if (rv > 0) {
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unsigned char *cp;
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bytes_read += rv;
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assert(bytes_read <= LBUF_SIZE - 1);
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/* Always NUL-terminate just in case. */
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buf[LBUF_SIZE - 1] = '\0';
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/*
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* Chomp line by line until we run out of buffer.
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* This does not take NUL characters into account.
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*/
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while ((cp = memchr(buf, '\n', bytes_read)) != NULL) {
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size_t bytes_line = cp - buf + 1;
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assert(bytes_line <= bytes_read);
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do_output(buf, bytes_line, logpar);
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bytes_read -= bytes_line;
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memmove(buf, cp + 1, bytes_read);
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}
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/* Wait until the buffer is full. */
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if (bytes_read < LBUF_SIZE - 1)
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return 1;
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do_output(buf, bytes_read, logpar);
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bytes_read = 0;
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return 1;
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} else if (rv == -1) {
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/* EINTR should trigger another read. */
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if (errno == EINTR) {
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return 1;
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} else {
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warn("read");
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return 0;
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}
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}
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/* Upon EOF, we have to flush what's left of the buffer. */
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if (bytes_read > 0) {
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do_output(buf, bytes_read, logpar);
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bytes_read = 0;
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}
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return 0;
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}
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/*
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* The default behavior is to stay silent if the user wants to redirect
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* output to a file and/or syslog. If neither are provided, then we bounce
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* everything back to parent's stdout.
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*/
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static void
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do_output(const unsigned char *buf, size_t len, struct log_params *logpar)
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{
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assert(len <= LBUF_SIZE);
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assert(logpar);
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if (len < 1)
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|
return;
|
|
if (logpar->dosyslog)
|
|
syslog(logpar->logpri, "%.*s", (int)len, buf);
|
|
if (logpar->outfd != -1) {
|
|
if (write(logpar->outfd, buf, len) == -1)
|
|
warn("write");
|
|
}
|
|
if (logpar->noclose && !logpar->dosyslog && logpar->outfd == -1)
|
|
printf("%.*s", (int)len, buf);
|
|
}
|
|
|
|
/*
|
|
* We use the global PID acquired directly from fork. If there is no valid
|
|
* child pid, the handler should be blocked and/or child_gone == 1.
|
|
*/
|
|
static void
|
|
handle_term(int signo)
|
|
{
|
|
if (pid > 0 && !child_gone)
|
|
kill(pid, signo);
|
|
terminate = 1;
|
|
}
|
|
|
|
static void
|
|
handle_chld(int signo)
|
|
{
|
|
(void)signo;
|
|
for (;;) {
|
|
int rv = waitpid(-1, NULL, WNOHANG);
|
|
if (pid == rv) {
|
|
child_gone = 1;
|
|
break;
|
|
} else if (rv == -1 && errno != EINTR) {
|
|
warn("waitpid");
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
usage(void)
|
|
{
|
|
(void)fprintf(stderr,
|
|
"usage: daemon [-cfrS] [-p child_pidfile] [-P supervisor_pidfile]\n"
|
|
" [-u user] [-o output_file] [-t title]\n"
|
|
" [-l syslog_facility] [-s syslog_priority]\n"
|
|
" [-T syslog_tag] [-m output_mask]\n"
|
|
"command arguments ...\n");
|
|
exit(1);
|
|
}
|