debug.c

mobile ip 在linux下的一种实现

/* $Id: debug.c,v 1.8 2001/08/05 17:32:51 jm Exp $
 * Debug function for debugging messages
 *
 * Dynamic hierarchial IP tunnel
 * Copyright (C) 1998-2000, Dynamics group
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See README and COPYING for
 * more details.
 */

#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>

#include "debug.h"

/* bit field operations */

#define DYN_SET_BIT(bits, bit) \
        (bits[((bit) & 0xff) / 32] |= (1 << ((bit) & 0x1f)))
#define DYN_CLR_BIT(bits, bit) \
        (bits[((bit) & 0xff) / 32] &= ~(1 << ((bit) & 0x1f)))
#define DYN_BIT(bits, bit) \
        (bits[((bit) & 0xff) / 32] & (1 << ((bit) & 0x1f)))

extern int opt_debug;

/* bit field for debug flags */
static char debug_flags_set = 0;
static unsigned int debug_flags[8]; /* bit field, len = 256 */

/* debug */
static char *default_debug = "-LBhf";

static void debug_initialize(void)
{
	int i;
	char *env;

	env = getenv("DYNAMICS_DEBUG");
	if (env == NULL)
		env = default_debug;

	if (*env == '-') {
		/* set all bits */
		for (i = 0; i < 8; i++)
			debug_flags[i] = (unsigned int)-1;
	}

	if (*env == '-') {
		for (env++; *env != '\0'; env++) {
			DYN_CLR_BIT(debug_flags, (unsigned char) *env);
		}
	} else {
		for ( ; *env != '\0'; env++) {
			DYN_SET_BIT(debug_flags, (unsigned char) *env);
			printf("Setting %c\n", *env);
		}
	}

	debug_flags_set = 1;

	if (DYN_BIT(debug_flags, 'D')) {
		printf("DEBUG_FLAGS[");
		for (i = 0; i < 8; i++)
			printf("%08x", debug_flags[i]);
		printf("]\n");
	}
}

void debug(char flag, char *format, ...)
{
	va_list ap;

	if (!opt_debug) return;

	if (debug_flags_set == 0)
		debug_initialize();

	if (!DYN_BIT(debug_flags, (unsigned char)flag))
		return;

	va_start(ap, format);
	vfprintf(stdout, format, ap);
	fflush(stdout);
	va_end(ap);
}

void nodebug(char flag, char *format, ...)
{
}

void debug_hexdump(char flag, const char *title, const unsigned char *buf,
		   int len)
{
	int i, left;
	const unsigned char *c = buf;

	if (!opt_debug)
		return;

	if (debug_flags_set == 0)
		debug_initialize();

	if (!DYN_BIT(debug_flags, (unsigned char) flag))
		return;

	printf("%s - hexdump (len=%i)\n", title, len);
	left = len;
	while (left > 0) {
		printf("\t");
		for (i = 0; i < 16; i++) {
			printf("%02x ", *c++);
			left--;
			if (left == 0)
				break;
		}
		printf("\n");
	}
}