1 files changed, 242 insertions, 0 deletions
diff --git a/logfile.c b/logfile.c
new file mode 100644
index 0000000..ca8c983
--- /dev/null
+++ b/logfile.c
@@ -0,0 +1,242 @@
+/* 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 <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "syslogd.h"
+
+
+typedef struct logfile_t {
+	struct logfile_t *next;
+	size_t size;
+	int fd;
+	char filename[];
+} logfile_t;
+
+
+typedef struct {
+	log_backend_t base;
+	logfile_t *list;
+	size_t maxsize;
+	int flags;
+} log_backend_file_t;
+
+
+static int logfile_open(logfile_t *file)
+{
+	struct stat sb;
+
+	file->fd = open(file->filename, O_WRONLY | O_CREAT, 0640);
+	if (file->fd < 0) {
+		perror(file->filename);
+		return -1;
+	}
+
+	if (lseek(file->fd, 0, SEEK_END))
+		goto fail;
+
+	if (fstat(file->fd, &sb))
+		goto fail;
+
+	file->size = sb.st_size;
+	return 0;
+fail:
+	perror(file->filename);
+	close(file->fd);
+	file->fd = -1;
+	return -1;
+}
+
+static logfile_t *logfile_create(const char *filename)
+{
+	logfile_t *file = calloc(1, sizeof(*file) + strlen(filename) + 1);
+
+	if (file == NULL) {
+		perror("calloc");
+		return NULL;
+	}
+
+	strcpy(file->filename, filename);
+
+	if (logfile_open(file)) {
+		free(file);
+		return NULL;
+	}
+
+	return file;
+}
+
+static int logfile_write(logfile_t *file, const syslog_msg_t *msg)
+{
+	const char *lvl_str, *fac_name;
+	char timebuf[32];
+	struct tm tm;
+	int ret;
+
+	if (file->fd < 0 && logfile_open(file) != 0)
+		return -1;
+
+	lvl_str = level_id_to_string(msg->level);
+	if (lvl_str == NULL)
+		return -1;
+
+	gmtime_r(&msg->timestamp, &tm);
+	strftime(timebuf, sizeof(timebuf), "%FT%T", &tm);
+
+	if (msg->ident != NULL) {
+		fac_name = facility_id_to_string(msg->facility);
+		if (fac_name == NULL)
+			return -1;
+
+		ret = dprintf(file->fd, "[%s][%s][%s][%u] %s\n", timebuf,
+			      fac_name, lvl_str, msg->pid, msg->message);
+	} else {
+		ret = dprintf(file->fd, "[%s][%s][%u] %s\n", timebuf, lvl_str,
+			      msg->pid, msg->message);
+	}
+
+	fsync(file->fd);
+
+	if (ret > 0)
+		file->size += ret;
+	return 0;
+}
+
+static int logfile_rotate(logfile_t *f, int flags)
+{
+	char timebuf[32];
+	char *filename;
+	struct tm tm;
+	time_t now;
+
+	if (flags & LOG_ROTATE_OVERWRITE) {
+		strcpy(timebuf, "1");
+	} else {
+		now = time(NULL);
+		gmtime_r(&now, &tm);
+		strftime(timebuf, sizeof(timebuf), "%FT%T", &tm);
+	}
+
+	filename = alloca(strlen(f->filename) + strlen(timebuf) + 2);
+	sprintf(filename, "%s.%s", f->filename, timebuf);
+
+	if (rename(f->filename, filename)) {
+		perror(filename);
+		return -1;
+	}
+
+	close(f->fd);
+	logfile_open(f);
+	return 0;
+}
+
+/*****************************************************************************/
+
+static int file_backend_init(log_backend_t *backend, int flags,
+			     size_t sizelimit)
+{
+	log_backend_file_t *log = (log_backend_file_t *)backend;
+
+	log->flags = flags;
+	log->maxsize = sizelimit;
+	return 0;
+}
+
+static void file_backend_cleanup(log_backend_t *backend)
+{
+	log_backend_file_t *log = (log_backend_file_t *)backend;
+	logfile_t *f;
+
+	while (log->list != NULL) {
+		f = log->list;
+		log->list = f->next;
+
+		close(f->fd);
+		free(f);
+	}
+}
+
+static int file_backend_write(log_backend_t *backend, const syslog_msg_t *msg)
+{
+	log_backend_file_t *log = (log_backend_file_t *)backend;
+	const char *ident;
+	char *filename;
+	logfile_t *f;
+	size_t len;
+
+	if (msg->ident != NULL) {
+		ident = msg->ident;
+	} else {
+		ident = facility_id_to_string(msg->facility);
+		if (ident == NULL)
+			return -1;
+	}
+
+	len = strlen(ident) + strlen(".log") + 1;
+	filename = alloca(len);
+	strcpy(filename, ident);
+	strcat(filename, ".log");
+
+	for (f = log->list; f != NULL; f = f->next) {
+		if (strcmp(filename, f->filename) == 0)
+			break;
+	}
+
+	if (f == NULL) {
+		f = logfile_create(filename);
+		if (f == NULL)
+			return -1;
+		f->next = log->list;
+		log->list = f;
+	}
+
+	if (logfile_write(f, msg))
+		return -1;
+
+	if ((log->flags & LOG_ROTATE_SIZE_LIMIT) && f->size >= log->maxsize)
+		logfile_rotate(f, log->flags);
+
+	return 0;
+}
+
+static void file_backend_rotate(log_backend_t *backend)
+{
+	log_backend_file_t *log = (log_backend_file_t *)backend;
+	logfile_t *f;
+
+	for (f = log->list; f != NULL; f = f->next)
+		logfile_rotate(f, log->flags);
+}
+
+log_backend_file_t filebackend = {
+	.base = {
+		.init = file_backend_init,
+		.cleanup = file_backend_cleanup,
+		.write = file_backend_write,
+		.rotate = file_backend_rotate,
+	},
+	.list = NULL,
+};
+
+log_backend_t *logmgr = (log_backend_t *)&filebackend;