/*

 * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998

 *	The Regents of the University of California.  All rights reserved.

 *

 * 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.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *	This product includes software developed by the Computer Systems

 *	Engineering Group at Lawrence Berkeley Laboratory.

 * 4. Neither the name of the University nor of the Laboratory may be used

 *    to endorse or promote products derived from this software without

 *    specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.

 */

/*

 * Utilities for message formatting used both by libpcap and rpcapd.

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include "ftmacros.h"

#include <stddef.h>

#include <stdarg.h>

#include <stdio.h>

#include <string.h>

#include <errno.h>

#include <pcap/pcap.h>

#include "portability.h"

#include "fmtutils.h"

/*

 * Generate an error message based on a format, arguments, and an

 * errno, with a message for the errno after the formatted output.

 */

void

pcap_fmt_errmsg_for_errno(char *errbuf, size_t errbuflen, int errnum,

    const char *fmt, ...)

{

	va_list ap;

	size_t msglen;

	char *p;

	size_t errbuflen_remaining;

	va_start(ap, fmt);

	pcap_vsnprintf(errbuf, errbuflen, fmt, ap);

	va_end(ap);

	msglen = strlen(errbuf);

	/*

	 * Do we have enough space to append ": "?

	 * Including the terminating '\0', that's 3 bytes.

	 */

	if (msglen + 3 > errbuflen) {

		/* No - just give them what we've produced. */

		return;

	}

	p = errbuf + msglen;

	errbuflen_remaining = errbuflen - msglen;

	*p++ = ':';

	*p++ = ' ';

	*p = '\0';

	msglen += 2;

	errbuflen_remaining -= 2;

	/*

	 * Now append the string for the error code.

	 */

#if defined(HAVE_STRERROR_S)

	/*

	 * We have a Windows-style strerror_s().

	 */

	errno_t err = strerror_s(p, errbuflen_remaining, errnum);

	if (err != 0) {

		/*

		 * It doesn't appear to be documented anywhere obvious

		 * what the error returns from strerror_s().

		 */

		pcap_snprintf(p, errbuflen_remaining, "Error %d", errnum);

	}

#elif defined(HAVE_GNU_STRERROR_R)

	/*

	 * We have a GNU-style strerror_r(), which is *not* guaranteed to

	 * do anything to the buffer handed to it, and which returns a

	 * pointer to the error string, which may or may not be in

	 * the buffer.

	 *

	 * It is, however, guaranteed to succeed.

	 */

	char strerror_buf[PCAP_ERRBUF_SIZE];

	char *errstring = strerror_r(errnum, strerror_buf, PCAP_ERRBUF_SIZE);

	pcap_snprintf(p, errbuflen_remaining, "%s", errstring);

#elif defined(HAVE_POSIX_STRERROR_R)

	/*

	 * We have a POSIX-style strerror_r(), which is guaranteed to fill

	 * in the buffer, but is not guaranteed to succeed.

	 */

	int err = strerror_r(errnum, p, errbuflen_remaining);

	if (err == EINVAL) {

		/*

		 * UNIX 03 says this isn't guaranteed to produce a

		 * fallback error message.

		 */

		pcap_snprintf(p, errbuflen_remaining, "Unknown error: %d",

		    errnum);

	} else if (err == ERANGE) {

		/*

		 * UNIX 03 says this isn't guaranteed to produce a

		 * fallback error message.

		 */

		pcap_snprintf(p, errbuflen_remaining,

		    "Message for error %d is too long", errnum);

	}

#else

	/*

	 * We have neither strerror_s() nor strerror_r(), so we're

	 * stuck with using pcap_strerror().

	 */

	pcap_snprintf(p, errbuflen_remaining, "%s", pcap_strerror(errnum));

#endif

}

#ifdef _WIN32

/*

 * Generate an error message based on a format, arguments, and a

 * Win32 error, with a message for the Win32 error after the formatted output.

 */

void

pcap_fmt_errmsg_for_win32_err(char *errbuf, size_t errbuflen, DWORD errnum,

    const char *fmt, ...)

{

	va_list ap;

	size_t msglen;

	char *p;

	size_t errbuflen_remaining;

	DWORD retval;

	char win32_errbuf[PCAP_ERRBUF_SIZE+1];

	va_start(ap, fmt);

	pcap_vsnprintf(errbuf, errbuflen, fmt, ap);

	va_end(ap);

	msglen = strlen(errbuf);

	/*

	 * Do we have enough space to append ": "?

	 * Including the terminating '\0', that's 3 bytes.

	 */

	if (msglen + 3 > errbuflen) {

		/* No - just give them what we've produced. */

		return;

	}

	p = errbuf + msglen;

	errbuflen_remaining = errbuflen - msglen;

	*p++ = ':';

	*p++ = ' ';

	*p = '\0';

	msglen += 2;

	errbuflen_remaining -= 2;

	/*

	 * Now append the string for the error code.

	 *

	 * XXX - what language ID to use?

	 *

	 * For UN*Xes, pcap_strerror() may or may not return localized

	 * strings.

	 *

	 * We currently don't have localized messages for libpcap, but

	 * we might want to do so.  On the other hand, if most of these

	 * messages are going to be read by libpcap developers and

	 * perhaps by developers of libpcap-based applications, English

	 * might be a better choice, so the developer doesn't have to

	 * get the message translated if it's in a language they don't

	 * happen to understand.

	 */

	retval = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS|FORMAT_MESSAGE_MAX_WIDTH_MASK,

	    NULL, errnum, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

	    win32_errbuf, PCAP_ERRBUF_SIZE, NULL);

	if (retval == 0) {

		/*

		 * Failed.

		 */

		pcap_snprintf(p, errbuflen_remaining,

		    "Couldn't get error message for error (%lu)", errnum);

		return;

	}

	pcap_snprintf(p, errbuflen_remaining, "%s (%lu)", win32_errbuf, errnum);

}

#endif