4 files changed, 320 insertions, 0 deletions
diff --git a/syslogd/Makemodule.am b/syslogd/Makemodule.am
new file mode 100644
index 0000000..489acc9
--- /dev/null
+++ b/syslogd/Makemodule.am
@@ -0,0 +1,8 @@
+usyslogd_SOURCES = syslogd/main.c
+usyslogd_SOURCES += syslogd/logfile.c syslogd/logfile.h
+usyslogd_CPPFLAGS = $(AM_CPPFLAGS)
+usyslogd_CFLAGS = $(AM_CFLAGS)
+usyslogd_LDFLAGS = $(AM_LDFLAGS)
+usyslogd_LDADD = libinit.a
+
+sbin_PROGRAMS += usyslogd
diff --git a/syslogd/logfile.c b/syslogd/logfile.c
new file mode 100644
index 0000000..a59f7e7
--- /dev/null
+++ b/syslogd/logfile.c
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * Copyright (C) 2018 - David Oberhollenzer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <fcntl.h>
+
+#include "logfile.h"
+
+
+logfile_t *logfile_create(const char *name)
+{
+	logfile_t *file;
+
+	file = calloc(1, sizeof(*file) + strlen(name) + 1);
+	if (file == NULL) {
+		perror("calloc");
+		return NULL;
+	}
+
+	strcpy(file->name, name);
+
+	file->fd = open(file->name, O_WRONLY | O_CREAT, 0640);
+	if (file->fd < 0)
+		goto fail;
+
+	if (lseek(file->fd, 0, SEEK_END))
+		goto fail;
+
+	return file;
+fail:
+	perror(file->name);
+	free(file);
+	return NULL;
+}
+
+void logfile_destroy(logfile_t *file)
+{
+	close(file->fd);
+	free(file);
+}
+
+void logfile_write(logfile_t *file, const char *format, ...)
+{
+	va_list ap;
+
+	va_start(ap, format);
+	vdprintf(file->fd, format, ap);
+	va_end(ap);
+
+	fsync(file->fd);
+}
diff --git a/syslogd/logfile.h b/syslogd/logfile.h
new file mode 100644
index 0000000..58da272
--- /dev/null
+++ b/syslogd/logfile.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * Copyright (C) 2018 - David Oberhollenzer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#ifndef LOGFILE_H
+#define LOGFILE_H
+
+typedef struct logfile_t {
+	struct logfile_t *next;
+	int fd;
+
+	char name[];
+} logfile_t;
+
+logfile_t *logfile_create(const char *name);
+
+void logfile_destroy(logfile_t *file);
+
+void logfile_write(logfile_t *file, const char *format, ...);
+
+#endif /* LOGFILE_H */
diff --git a/syslogd/main.c b/syslogd/main.c
new file mode 100644
index 0000000..a5702b7
--- /dev/null
+++ b/syslogd/main.c
@@ -0,0 +1,209 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * Copyright (C) 2018 - David Oberhollenzer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#include "logfile.h"
+#include "util.h"
+
+
+#define SYSLOG_SOCKET "/dev/log"
+#define SYSLOG_PATH "/var/log"
+
+
+static volatile sig_atomic_t syslog_run = 1;
+static logfile_t *logfiles = NULL;
+
+static const enum_map_t facilities[] = {
+	{ "kernel.log", 0 },
+	{ "user.log", 1 },
+	{ "mail.log", 2 },
+	{ "daemon.log", 3 },
+	{ "auth.log", 4 },
+	{ "syslog.log", 5 },
+	{ "lpr.log", 6 },
+	{ "news.log", 7 },
+	{ "uucp.log", 8 },
+	{ "clock.log", 9 },
+	{ "authpriv.log", 10 },
+	{ "ftp.log", 11 },
+	{ "ntp.log", 12 },
+	{ "audit.log", 13 },
+	{ "alert.log", 14 },
+	{ "cron.log", 15 },
+	{ "local0.log", 16 },
+	{ "local1.log", 17 },
+	{ "local2.log", 18 },
+	{ "local3.log", 19 },
+	{ "local4.log", 20 },
+	{ "local5.log", 21 },
+	{ "local6.log", 22 },
+	{ "local7.log", 23 },
+	{ NULL, 0 },
+};
+
+static const enum_map_t levels[] = {
+	{ "emergency", 0 },
+	{ "alert", 1 },
+	{ "critical", 2 },
+	{ "error", 3 },
+	{ "warning", 4 },
+	{ "notice", 5 },
+	{ "info", 6 },
+	{ "debug", 7 },
+	{ NULL, 0 },
+};
+
+
+static int directory_setup(void)
+{
+	if (mkdir(SYSLOG_PATH, 0755)) {
+		if (errno != EEXIST) {
+			perror("mkdir " SYSLOG_PATH);
+			return -1;
+		}
+	}
+
+	if (chdir(SYSLOG_PATH)) {
+		perror("cd " SYSLOG_PATH);
+		return -1;
+	}
+
+	return 0;
+}
+
+static void sighandler(int signo)
+{
+	switch (signo) {
+	case SIGINT:
+	case SIGTERM:
+		syslog_run = 0;
+		break;
+	default:
+		break;
+	}
+}
+
+static void signal_setup(void)
+{
+	struct sigaction act;
+
+	memset(&act, 0, sizeof(act));
+	act.sa_handler = sighandler;
+
+	sigaction(SIGINT, &act, NULL);
+	sigaction(SIGTERM, &act, NULL);
+}
+
+static int print_to_log(int facility, int level, const char *data)
+{
+	const char *fac_name, *lvl_str;
+	logfile_t *log;
+
+	fac_name = enum_to_name(facilities, facility);
+	if (fac_name == NULL)
+		return -1;
+
+	lvl_str = enum_to_name(levels, level);
+	if (lvl_str == NULL)
+		return -1;
+
+	for (log = logfiles; log != NULL; log = log->next) {
+		if (!strcmp(log->name, fac_name))
+			break;
+	}
+
+	if (log == NULL) {
+		log = logfile_create(fac_name);
+		if (log == NULL)
+			return -1;
+		log->next = logfiles;
+		logfiles = log;
+	}
+
+	logfile_write(log, "[%s] %s", lvl_str, data);
+	return 0;
+}
+
+static int handle_data(int fd)
+{
+	char buffer[2048], *ptr;
+	int i = 0, priority;
+	ssize_t ret;
+
+	memset(buffer, 0, sizeof(buffer));
+
+	ret = read(fd, buffer, sizeof(buffer));
+	if (ret <= 0)
+		return -1;
+
+	for (ptr = buffer; isspace(*ptr); ++ptr)
+		;
+	if (*(ptr++) != '<')
+		return -1;
+	if (!isdigit(*ptr))
+		return -1;
+	for (priority = 0; isdigit(*ptr); ++ptr)
+		priority = priority * 10 + (*ptr) - '0';
+	if (*(ptr++) != '>')
+		return -1;
+	while (isspace(*ptr))
+		++ptr;
+
+	return print_to_log(priority >> 3, priority & 0x07, ptr);
+}
+
+int main(void)
+{
+	int sfd, status = EXIT_FAILURE;
+	logfile_t *log;
+
+	signal_setup();
+
+	sfd = mksock(SYSLOG_SOCKET, SOCK_FLAG_EVERYONE | SOCK_FLAG_DGRAM);
+	if (sfd < 0)
+		return EXIT_FAILURE;
+
+	if (directory_setup())
+		goto out;
+
+	while (syslog_run) {
+		handle_data(sfd);
+	}
+
+	status = EXIT_SUCCESS;
+out:
+	while (logfiles != NULL) {
+		log = logfiles;
+		logfiles = logfiles->next;
+
+		logfile_destroy(log);
+	}
+	if (sfd > 0)
+		close(sfd);
+	unlink(SYSLOG_SOCKET);
+	return status;
+}