Add file-based logging

We can now log to a specific file on the filesystem.
Signed-off-by: Shawn Webb <shawn.webb@hardenedbsd.org>
Sponsored-by:	BlackhawkNest, Inc

Makefile

@@ -4,6 +4,7 @@ INCS=		liblattutil.h
 
 SRCS+=		config.c
 SRCS+=		log-dummy.c
+SRCS+=		log-file.c
 SRCS+=		log-main.c
 SRCS+=		log-stdio.c
 SRCS+=		log-sqlite3.c

include/liblattutil.h

@@ -284,6 +284,15 @@ bool lattutil_log_syslog_init(lattutil_log_t *, int, int);
  */
 void lattutil_log_dummy_init(lattutil_log_t *);
 
+/*
+ * Initialize file-based logging
+ *
+ * @param Logging object
+ * @param Path to file, or NULL for "/dev/stdout"
+ * @return True on success, false otherwise
+ */
+bool lattutil_log_file_init(lattutil_log_t *, const char *);
+
 /**
  * Initialize stdio-based logging
  *

src/log-file.c

+/*-
+ * Copyright (c) 2021 Shawn Webb <shawn.webb@hardenedbsd.org>
+ *
+ * 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 ``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 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <pthread.h>
+
+#include "liblattutil.h"
+
+typedef struct _log_file_aux {
+	FILE		*lfa_file;
+	pthread_mutex_t	 lfa_mtx;
+} log_file_aux_t;
+
+static ssize_t _lattutil_log_file_debug(lattutil_log_t *, int,
+    const char *, ...);
+static ssize_t _lattutil_log_file_err(lattutil_log_t *, int,
+    const char *, ...);
+static ssize_t _lattutil_log_file_info(lattutil_log_t *, int,
+    const char *, ...);
+static ssize_t _lattutil_log_file_warn(lattutil_log_t *, int,
+    const char *, ...);
+static void _lattutil_log_file_close(lattutil_log_t *);
+
+EXPORTED_SYM
+bool
+lattutil_log_file_init(lattutil_log_t *logp, const char *path)
+{
+	log_file_aux_t *lfile;
+
+	if (path == NULL) {
+		path = "/dev/stdout";
+	}
+
+	lfile = calloc(1, sizeof(*lfile));
+	if (lfile == NULL) {
+		return (false);
+	}
+
+	if (pthread_mutex_init(&(lfile->lfa_mtx), NULL)) {
+		free(lfile);
+		return (false);
+	}
+
+	lfile->lfa_file = fopen(path, "ae");
+	if (lfile->lfa_file == NULL) {
+		pthread_mutex_destroy(&(lfile->lfa_mtx));
+		free(lfile);
+		return (false);
+	}
+
+	lattutil_log_set_aux(logp, lfile, sizeof(*lfile));
+
+	logp->ll_log_close = _lattutil_log_file_close;
+	logp->ll_log_debug = _lattutil_log_file_debug;
+	logp->ll_log_err = _lattutil_log_file_err;
+	logp->ll_log_info = _lattutil_log_file_info;
+	logp->ll_log_warn = _lattutil_log_file_warn;
+
+	return (true);
+}
+
+static ssize_t
+_lattutil_log_file_debug(lattutil_log_t *logp, int verbose,
+    const char *fmt, ...)
+{
+	log_file_aux_t *lfile;
+	va_list args;
+	size_t len;
+	char *msg;
+
+	if (logp == NULL || fmt == NULL) {
+		return (-1);
+	}
+
+	va_start(args, fmt);
+	if (verbose == -1  || verbose >= logp->ll_verbosity) {
+		len = 0;
+		lfile = lattutil_log_get_aux(logp, &len);
+		if (lfile == NULL || len != sizeof(*lfile)) {
+			len = -1;
+			goto end;
+		}
+		msg = NULL;
+		vasprintf(&msg, fmt, args);
+		if (msg == NULL) {
+			len = -1;
+			goto end;
+		}
+		len = strlen(msg);
+		pthread_mutex_lock(&(lfile->lfa_mtx));
+		fprintf(lfile->lfa_file, "DEBUG: %s\n", msg);
+		fflush(lfile->lfa_file);
+		pthread_mutex_unlock(&(lfile->lfa_mtx));
+		free(msg);
+	}
+	va_end(args);
+
+end:
+	return (len);
+}
+
+static ssize_t
+_lattutil_log_file_err(lattutil_log_t *logp, int verbose,
+    const char *fmt, ...)
+{
+	log_file_aux_t *lfile;
+	va_list args;
+	size_t len;
+	char *msg;
+
+	if (logp == NULL || fmt == NULL) {
+		return (-1);
+	}
+
+	va_start(args, fmt);
+	if (verbose == -1  || verbose >= logp->ll_verbosity) {
+		len = 0;
+		lfile = lattutil_log_get_aux(logp, &len);
+		if (lfile == NULL || len != sizeof(*lfile)) {
+			len = -1;
+			goto end;
+		}
+		msg = NULL;
+		vasprintf(&msg, fmt, args);
+		if (msg == NULL) {
+			len = -1;
+			goto end;
+		}
+		len = strlen(msg);
+		pthread_mutex_lock(&(lfile->lfa_mtx));
+		fprintf(lfile->lfa_file, "ERROR: %s\n", msg);
+		fflush(lfile->lfa_file);
+		pthread_mutex_unlock(&(lfile->lfa_mtx));
+		free(msg);
+	}
+	va_end(args);
+
+end:
+	return (len);
+}
+
+static ssize_t
+_lattutil_log_file_info(lattutil_log_t *logp, int verbose,
+    const char *fmt, ...)
+{
+	log_file_aux_t *lfile;
+	va_list args;
+	size_t len;
+	char *msg;
+
+	if (logp == NULL || fmt == NULL) {
+		return (-1);
+	}
+
+	va_start(args, fmt);
+	if (verbose == -1  || verbose >= logp->ll_verbosity) {
+		len = 0;
+		lfile = lattutil_log_get_aux(logp, &len);
+		if (lfile == NULL || len != sizeof(*lfile)) {
+			len = -1;
+			goto end;
+		}
+		msg = NULL;
+		vasprintf(&msg, fmt, args);
+		if (msg == NULL) {
+			len = -1;
+			goto end;
+		}
+		len = strlen(msg);
+		pthread_mutex_lock(&(lfile->lfa_mtx));
+		fprintf(lfile->lfa_file, "INFO: %s\n", msg);
+		fflush(lfile->lfa_file);
+		pthread_mutex_unlock(&(lfile->lfa_mtx));
+		free(msg);
+	}
+	va_end(args);
+
+end:
+	return (len);
+}
+
+static ssize_t
+_lattutil_log_file_warn(lattutil_log_t *logp, int verbose,
+    const char *fmt, ...)
+{
+	log_file_aux_t *lfile;
+	va_list args;
+	size_t len;
+	char *msg;
+
+	if (logp == NULL || fmt == NULL) {
+		return (-1);
+	}
+
+	va_start(args, fmt);
+	if (verbose == -1  || verbose >= logp->ll_verbosity) {
+		len = 0;
+		lfile = lattutil_log_get_aux(logp, &len);
+		if (lfile == NULL || len != sizeof(*lfile)) {
+			len = -1;
+			goto end;
+		}
+		msg = NULL;
+		vasprintf(&msg, fmt, args);
+		if (msg == NULL) {
+			len = -1;
+			goto end;
+		}
+		len = strlen(msg);
+		pthread_mutex_lock(&(lfile->lfa_mtx));
+		fprintf(lfile->lfa_file, "WARNING: %s\n", msg);
+		fflush(lfile->lfa_file);
+		pthread_mutex_unlock(&(lfile->lfa_mtx));
+		free(msg);
+	}
+	va_end(args);
+
+end:
+	return (len);
+}
+
+static void
+_lattutil_log_file_close(lattutil_log_t *logp)
+{
+
+}