finit/src/log.c

/* Finit daemon log functions
 *
 * Copyright (c) 2008-2025  Joachim Wiberg <troglobit@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "config.h"		/* Generated by configure script */

#include <stdio.h>
#include <stdarg.h>
#include <time.h>
#ifdef _LIBITE_LITE
# include <libite/lite.h>
#else
# include <lite/lite.h>
#endif

#define SYSLOG_NAMES
#include <syslog.h>

#include "finit.h"
#include "helpers.h"
#include "log.h"
#include "util.h"

static int up       = 0;
static int loglevel = LOG_INFO;

void log_init(void)
{
	if (debug)
		loglevel = LOG_DEBUG;
	else
		loglevel = LOG_INFO;
}

/* If we enabled terse mode at boot, restore to previous setting at shutdown */
void log_exit(void)
{
	enable_progress(1);
}

static int log_open(void)
{
	int opts;

	if (up)
		return 1;
	if (access("/dev/log", W_OK))
		return 0;

	opts = LOG_CONS | LOG_PID;
	if (debug)
		opts |= LOG_PERROR;

	openlog("finit", opts, LOG_DAEMON);
	setlogmask(LOG_UPTO(loglevel));

	return up = 1;
}

static void log_close(void)
{
	closelog();
	up = 0;
}

/* Toggle debug mode */
void log_debug(void)
{
	debug = !debug;

	log_close();
	log_init();
	log_open();

	logit(LOG_NOTICE, "Debug mode %s", debug ? "enabled" : "disabled");
}

static const char *l2s(int prio)
{
	int level = prio & ~LOG_CONSOLE;

        switch (level) {
        case LOG_ERR:     return "ERR";
        case LOG_WARNING: return "WRN";
        case LOG_NOTICE:  return "NOT";
        case LOG_INFO:    return "NFO";
        case LOG_DEBUG:   return "DBG";
        default:          break;
        }
        return "UNK";
}

static int s2f(const char *str)
{
	for (int i = 0; facilitynames[i].c_name; i++) {
		if (string_match(facilitynames[i].c_name, str))
			return facilitynames[i].c_val;
	}

	return -1;
}

static int s2l(const char *str)
{
	for (int i = 0; prioritynames[i].c_name; i++) {
		if (string_match(prioritynames[i].c_name, str))
			return prioritynames[i].c_val;
	}

	return -1;
}

/*
 * Parse syslog facility.priority strings into their numerical values
 * using arrays defined in <syslog.h>.  Note, the 'prio' argument may
 * be one of:
 *
 *  - facility.level
 *  - facility
 *  - level
 *
 * It is up to the callee to assign defaults to 'facility' and 'level'
 * before calling this function.  If There is any match the respective
 * facility or level will be assigned and this function returns OK.
 */
int log_parse(char *prio, int *facility, int *level)
{
	char *fac = prio, *lvl;
	int f = -1;
	int l = -1;

	if (!prio || !facility || !level)
		return -1;

	lvl = strchr(prio, '.');
	if (lvl) {
		*lvl = 0;
		lvl++;
	}

	if (lvl && *lvl)
		l = s2l(lvl);

	f = s2f(fac);
	if (l < 0)
		l = s2l(fac);

	if (l < 0 && f <= 0)
		return -1;

	if (l <= LOG_DEBUG)
		*level = l;

	if (f <= LOG_LOCAL7)
		*facility = f;

	return 0;
}

/*
 * Log to /dev/kmsg until syslogd has started, then openlog()
 * and continue logging as a regular daemon.
 */
void logit(int prio, const char *fmt, ...)
{
	va_list ap;
	FILE *fp;

	va_start(ap, fmt);

	if (up || log_open()) {
		vsyslog(prio, fmt, ap);
		goto done;
	}

	if (LOG_PRI(prio) > loglevel)
		goto done;

	if (in_container() || !(fp = fopen("/dev/kmsg", "w"))) {
		static char buf[512];
		time_t now;
		size_t pos;

		now = time(NULL);
		pos = (int)strftime(buf, sizeof(buf), "%FT%T", localtime(&now));
		pos += snprintf(&buf[pos], sizeof(buf) - pos, " [%s]: ", l2s(prio));
		vsnprintf(&buf[pos], sizeof(buf) - pos, fmt, ap);
		strlcat(buf, "\n", sizeof(buf));
		fputs(buf, stderr);
		goto done;
	}

	fprintf(fp, "<%d>finit[1]: ", LOG_DAEMON | prio);
	vfprintf(fp, fmt, ap);
	fclose(fp);

	if (debug) {
		va_end(ap);
		va_start(ap, fmt);
		vfprintf(stderr, fmt, ap);
		fputs("\n", stderr);
	}

done:
	va_end(ap);
}

/*
 * Log to file, intended for debug only.
 */
void flog(char *file, const char *fmt, ...)
{
        char fn[80];
        va_list ap;
        FILE *fp;

        snprintf(fn, sizeof(fn), "/tmp/%s.log", file);
        fp = fopen(fn, "a");
        if (!fp)
                return;

        va_start(ap, fmt);
        vfprintf(fp, fmt, ap);
        va_end(ap);

        fclose(fp);
}


/**
 * Local Variables:
 *  indent-tabs-mode: t
 *  c-file-style: "linux"
 * End:
 */