Refactor logging and add logfile support

idevicerestore will now also create a logfile automatically, unless
disabled with --logfile=NONE.

1 files changed, 210 insertions, 0 deletions

diff --git a/src/log.c b/src/log.c
new file mode 100644
index 0000000..e6a3c8a
--- /dev/null
+++ b/src/log.c
@@ -0,0 +1,210 @@
+/*
+ * log.c
+ *
+ * Copyright (c) 2024 Nikias Bassen. All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <time.h>
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <sys/time.h>
+#endif
+#include <errno.h>
+
+#include <libimobiledevice-glue/thread.h>
+#include <plist/plist.h>
+
+#include "log.h"
+
+static int stderr_enabled = 1;
+
+int log_level = LL_VERBOSE;
+int print_level = LL_INFO;
+
+static void (*print_func)(int level, const char* fmt, va_list) = NULL;
+
+const char *_level_label[6] = {
+	"  <Error>",
+	"<Warning>",
+	" <Notice>",
+	"   <Info>",
+	"<Verbose>",
+	"  <Debug>"	
+};
+
+// Reference: https://stackoverflow.com/a/2390626/1806760
+// Initializer/finalizer sample for MSVC and GCC/Clang.
+// 2010-2016 Joe Lowe. Released into the public domain.
+
+#ifdef __cplusplus
+    #define INITIALIZER(f) \
+        static void f(void); \
+        struct f##_t_ { f##_t_(void) { f(); } }; static f##_t_ f##_; \
+        static void f(void)
+#elif defined(_MSC_VER)
+    #pragma section(".CRT$XCU",read)
+    #define INITIALIZER2_(f,p) \
+        static void f(void); \
+        __declspec(allocate(".CRT$XCU")) void (*f##_)(void) = f; \
+        __pragma(comment(linker,"/include:" p #f "_")) \
+        static void f(void)
+    #ifdef _WIN64
+        #define INITIALIZER(f) INITIALIZER2_(f,"")
+    #else
+        #define INITIALIZER(f) INITIALIZER2_(f,"_")
+    #endif
+#else
+    #define INITIALIZER(f) \
+        static void f(void) __attribute__((__constructor__)); \
+        static void f(void)
+#endif
+
+static mutex_t log_mutex;
+
+static void logger_deinit(void)
+{
+	mutex_destroy(&log_mutex);
+}
+
+INITIALIZER(logger_init)
+{
+	mutex_init(&log_mutex);
+	atexit(logger_deinit);
+}
+
+void logger(enum loglevel level, const char *fmt, ...)
+{
+	va_list ap;
+	char *fs;
+
+	if (level > log_level)
+		return;
+
+	mutex_lock(&log_mutex);
+
+	size_t fslen = 24 + strlen(fmt);
+	fs = malloc(fslen);
+
+#ifdef _WIN32
+	SYSTEMTIME lt;
+	GetLocalTime(&lt);
+	snprintf(fs, 24, "%02d:%02d:%02d.%03d", lt.wHour, lt.wMinute, lt.wSecond, lt.wMilliseconds);
+#else
+	struct timeval ts;
+	struct tm tp_;
+	struct tm *tp;
+
+	gettimeofday(&ts, NULL);
+#ifdef HAVE_LOCALTIME_R
+	tp = localtime_r(&ts.tv_sec, &tp_);
+#else
+	tp = localtime(&ts.tv_sec);
+#endif
+
+	strftime(fs, 9, "%H:%M:%S", tp);
+	snprintf(fs+8, fslen-8, ".%03d %s %s", (int)(ts.tv_usec / 1000), _level_label[level], fmt);
+#endif
+
+	va_start(ap, fmt);
+	if (print_func) {
+		if (stderr_enabled) {
+			vfprintf(stderr, fs, ap);
+			fflush(stderr);
+		}
+		if (level <= print_level) {
+			// skip the timestamp and log level string
+			print_func(level, fs+23, ap);
+		}
+	} else {
+		vprintf(fs, ap);
+	}
+
+	va_end(ap);
+
+	free(fs);
+
+	mutex_unlock(&log_mutex);
+}
+
+void logger_dump_hex(enum loglevel level, const void* buf, unsigned int len)
+{
+	char *fs;
+
+	if (level > log_level)
+		return;
+
+	mutex_lock(&log_mutex);
+
+	fs = (char*)malloc(len * 3 + 1);
+	for (unsigned int i = 0; i < len; i++) {
+		snprintf(fs + i*3, 3, "%02x%c", ((unsigned char*)buf)[i], (i < len-1) ? ' ' : '\n');
+	}
+	if (print_func) {
+		if (stderr_enabled) {
+			fprintf(stderr, "%s", fs);
+			fflush(stderr);
+		}
+		if (level <= print_level) {
+			print_func(level, "%s", fs);
+		}
+	} else {
+		printf("%s", fs);
+	}
+	free(fs);
+	
+	mutex_unlock(&log_mutex);
+}
+
+void logger_dump_plist(enum loglevel level, plist_t plist, int human_readable)
+{
+	if (level > log_level)
+		return;
+	mutex_lock(&log_mutex);
+	plist_write_to_stream(plist, stderr_enabled ? stderr : stdout, (human_readable) ? PLIST_FORMAT_PRINT : PLIST_FORMAT_XML, PLIST_OPT_NONE);
+	mutex_unlock(&log_mutex);
+}
+
+int logger_set_logfile(const char* path)
+{
+	if (!path || !strcasecmp(path, "NULL") || !strcasecmp(path, "NONE")) {
+		stderr_enabled = 0;
+		return 0;
+	}
+	stderr_enabled = 1;
+	if (strcmp(path, "-")) {
+		FILE* newf = freopen(path, "w", stderr);
+		if (!newf) {
+			logger(LL_ERROR, "Could not open logfile '%s': %s\n", path, strerror(errno));
+			return -1;
+		}
+	}
+	return 0;
+}
+
+void logger_set_print_func(void (*func)(int, const char*, va_list))
+{
+	print_func = func;
+}