/src/libpcap/fmtutils.c

Source (jump to first uncovered line)
/*
 * 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.
 */

#include <config.h>

#include "ftmacros.h"

#include <stddef.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#include "pcap-int.h"

#include "portability.h"

#include "fmtutils.h"

#ifdef _WIN32
#include "charconv.h"
#endif

/*
 * Set the encoding.
 */
#ifdef _WIN32
/*
 * True if we should use UTF-8.
 */
static int use_utf_8;

void
pcapint_fmt_set_encoding(unsigned int opts)
{
  if (opts == PCAP_CHAR_ENC_UTF_8)
    use_utf_8 = 1;
}
#else
void
pcapint_fmt_set_encoding(unsigned int opts _U_)
{
  /*
   * Nothing to do here.
   */
}
#endif

#ifdef _WIN32
/*
 * Convert a null-terminated UTF-16LE string to UTF-8, putting it into
 * a buffer starting at the specified location and stopping if we go
 * past the specified size.  This will only put out complete UTF-8
 * sequences.
 *
 * We do this ourselves because Microsoft doesn't offer a "convert and
 * stop at a UTF-8 character boundary if we run out of space" routine.
 */
#define IS_LEADING_SURROGATE(c) \
  ((c) >= 0xd800 && (c) < 0xdc00)
#define IS_TRAILING_SURROGATE(c) \
  ((c) >= 0xdc00 && (c) < 0xe000)
#define SURROGATE_VALUE(leading, trailing) \
  (((((leading) - 0xd800) << 10) | ((trailing) - 0xdc00)) + 0x10000)
#define REPLACEMENT_CHARACTER 0x0FFFD

static char *
utf_16le_to_utf_8_truncated(const wchar_t *utf_16, char *utf_8,
    size_t utf_8_len)
{
  wchar_t c, c2;
  uint32_t uc;

  if (utf_8_len == 0) {
    /*
     * Not even enough room for a trailing '\0'.
     * Don't put anything into the buffer.
     */
    return (utf_8);
  }

  while ((c = *utf_16++) != '\0') {
    if (IS_LEADING_SURROGATE(c)) {
      /*
       * Leading surrogate.  Must be followed by
       * a trailing surrogate.
       */
      c2 = *utf_16;
      if (c2 == '\0') {
        /*
         * Oops, string ends with a lead
         * surrogate.  Try to drop in
         * a REPLACEMENT CHARACTER, and
         * don't move the string pointer,
         * so on the next trip through
         * the loop we grab the terminating
         * '\0' and quit.
         */
        uc = REPLACEMENT_CHARACTER;
      } else {
        /*
         * OK, we can consume this 2-octet
         * value.
         */
        utf_16++;
        if (IS_TRAILING_SURROGATE(c2)) {
          /*
           * Trailing surrogate.
           * This calculation will,
           * for c being a leading
           * surrogate and c2 being
           * a trailing surrogate,
           * produce a value between
           * 0x100000 and 0x10ffff,
           * so it's always going to be
           * a valid Unicode code point.
           */
          uc = SURROGATE_VALUE(c, c2);
        } else {
          /*
           * Not a trailing surrogate;
           * try to drop in a
           * REPLACEMENT CHARACTER.
           */
          uc = REPLACEMENT_CHARACTER;
        }
      }
    } else {
      /*
       * Not a leading surrogate.
       */
      if (IS_TRAILING_SURROGATE(c)) {
        /*
         * Trailing surrogate without
         * a preceding leading surrogate.
         * Try to drop in a REPLACEMENT
         * CHARACTER.
         */
        uc = REPLACEMENT_CHARACTER;
      } else {
        /*
         * This is a valid BMP character;
         * drop it in.
         */
        uc = c;
      }
    }

    /*
     * OK, uc is a valid Unicode character; how
     * many bytes worth of UTF-8 does it require?
     */
    if (uc < 0x0080) {
      /* 1 byte. */
      if (utf_8_len < 2) {
        /*
         * Not enough room for that byte
         * plus a trailing '\0'.
         */
        break;
      }
      *utf_8++ = (char)uc;
      utf_8_len--;
    } else if (uc < 0x0800) {
      /* 2 bytes. */
      if (utf_8_len < 3) {
        /*
         * Not enough room for those bytes
         * plus a trailing '\0'.
         */
        break;
      }
      *utf_8++ = ((uc >> 6) & 0x3F) | 0xC0;
      *utf_8++ = ((uc >> 0) & 0x3F) | 0x80;
      utf_8_len -= 2;
    } else if (uc < 0x010000) {
      /* 3 bytes. */
      if (utf_8_len < 4) {
        /*
         * Not enough room for those bytes
         * plus a trailing '\0'.
         */
        break;
      }
      *utf_8++ = ((uc >> 12) & 0x0F) | 0xE0;
      *utf_8++ = ((uc >> 6) & 0x3F) | 0x80;
      *utf_8++ = ((uc >> 0) & 0x3F) | 0x80;
      utf_8_len -= 3;
    } else {
      /* 4 bytes. */
      if (utf_8_len < 5) {
        /*
         * Not enough room for those bytes
         * plus a trailing '\0'.
         */
        break;
      }
      *utf_8++ = ((uc >> 18) & 0x03) | 0xF0;
      *utf_8++ = ((uc >> 12) & 0x3F) | 0x80;
      *utf_8++ = ((uc >> 6) & 0x3F) | 0x80;
      *utf_8++ = ((uc >> 0) & 0x3F) | 0x80;
      utf_8_len -= 3;
    }
  }

  /*
   * OK, we have enough room for (at least) a trailing '\0'.
   * (We started out with enough room, thanks to the test
   * for a zero-length buffer at the beginning, and if
   * there wasn't enough room for any character we wanted
   * to put into the buffer *plus* a trailing '\0',
   * we'd have quit before putting it into the buffer,
   * and thus would have left enough room for the trailing
   * '\0'.)
   *
   * Drop it in.
   */
  *utf_8 = '\0';

  /*
   * Return a pointer to the terminating '\0', in case we
   * want to drop something in after that.
   */
  return (utf_8);
}
#endif /* _WIN32 */

/*
 * Generate an error message based on a format, arguments, and an
 * errno, with a message for the errno after the formatted output.
 */
void
pcapint_fmt_errmsg_for_errno(char *errbuf, size_t errbuflen, int errnum,
    const char *fmt, ...)
{
  va_list ap;

  va_start(ap, fmt);
  pcapint_vfmt_errmsg_for_errno(errbuf, errbuflen, errnum, fmt, ap);
  va_end(ap);
}

void
pcapint_vfmt_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;

  (void)vsnprintf(errbuf, errbuflen, fmt, 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';
  errbuflen_remaining -= 2;

  /*
   * Now append the string for the error code.
   */
#if defined(HAVE__WCSERROR_S)
  /*
   * We have a Windows-style _wcserror_s().
   * Generate a UTF-16LE error message.
   */
  wchar_t utf_16_errbuf[PCAP_ERRBUF_SIZE];
  errno_t err = _wcserror_s(utf_16_errbuf, PCAP_ERRBUF_SIZE, errnum);
  if (err != 0) {
    /*
     * It doesn't appear to be documented anywhere obvious
     * what the error returns from _wcserror_s().
     */
    snprintf(p, errbuflen_remaining, "Error %d", errnum);
    return;
  }

  /*
   * Now convert it from UTF-16LE to UTF-8, dropping it in the
   * remaining space in the buffer, and truncating it - cleanly,
   * on a UTF-8 character boundary - if it doesn't fit.
   */
  utf_16le_to_utf_8_truncated(utf_16_errbuf, p, errbuflen_remaining);

  /*
   * Now, if we're not in UTF-8 mode, convert errbuf to the
   * local code page.
   */
  if (!use_utf_8)
    utf_8_to_acp_truncated(errbuf);
#else
  /*
   * Either Windows without _wcserror_s() or not Windows.  Let pcap_strerror()
   * solve the non-UTF-16 part of this problem space.
   */
  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
pcapint_fmt_errmsg_for_win32_err(char *errbuf, size_t errbuflen, DWORD errnum,
    const char *fmt, ...)
{
  va_list ap;

  va_start(ap, fmt);
  pcapint_vfmt_errmsg_for_win32_err(errbuf, errbuflen, errnum, fmt, ap);
  va_end(ap);
}

void
pcapint_vfmt_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;
  wchar_t utf_16_errbuf[PCAP_ERRBUF_SIZE];
  size_t utf_8_len;

  vsnprintf(errbuf, errbuflen, fmt, 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 = FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS|FORMAT_MESSAGE_MAX_WIDTH_MASK,
      NULL, errnum, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
      utf_16_errbuf, PCAP_ERRBUF_SIZE, NULL);
  if (retval == 0) {
    /*
     * Failed.
     */
    snprintf(p, errbuflen_remaining,
        "Couldn't get error message for error (%lu)", errnum);
    return;
  }

  /*
   * Now convert it from UTF-16LE to UTF-8.
   */
  p = utf_16le_to_utf_8_truncated(utf_16_errbuf, p, errbuflen_remaining);

  /*
   * Now append the error number, if it fits.
   */
  utf_8_len = p - errbuf;
  errbuflen_remaining -= utf_8_len;
  if (utf_8_len == 0) {
    /* The message was empty. */
    snprintf(p, errbuflen_remaining, "(%lu)", errnum);
  } else
    snprintf(p, errbuflen_remaining, " (%lu)", errnum);

  /*
   * Now, if we're not in UTF-8 mode, convert errbuf to the
   * local code page.
   */
  if (!use_utf_8)
    utf_8_to_acp_truncated(errbuf);
}
#endif

Coverage Report

Created: 2024-07-23 06:08

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
3		* The Regents of the University of California. All rights reserved.
4		*
5		* Redistribution and use in source and binary forms, with or without
6		* modification, are permitted provided that the following conditions
7		* are met:
8		* 1. Redistributions of source code must retain the above copyright
9		* notice, this list of conditions and the following disclaimer.
10		* 2. Redistributions in binary form must reproduce the above copyright
11		* notice, this list of conditions and the following disclaimer in the
12		* documentation and/or other materials provided with the distribution.
13		* 3. All advertising materials mentioning features or use of this software
14		* must display the following acknowledgement:
15		* This product includes software developed by the Computer Systems
16		* Engineering Group at Lawrence Berkeley Laboratory.
17		* 4. Neither the name of the University nor of the Laboratory may be used
18		* to endorse or promote products derived from this software without
19		* specific prior written permission.
20		*
21		* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22		* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23		* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24		* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25		* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26		* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27		* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28		* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29		* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30		* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31		* SUCH DAMAGE.
32		*/
33
34		/*
35		* Utilities for message formatting used both by libpcap and rpcapd.
36		*/
37
38		#include <config.h>
39
40		#include "ftmacros.h"
41
42		#include <stddef.h>
43		#include <stdarg.h>
44		#include <stdio.h>
45		#include <string.h>
46		#include <errno.h>
47
48		#include "pcap-int.h"
49
50		#include "portability.h"
51
52		#include "fmtutils.h"
53
54		#ifdef _WIN32
55		#include "charconv.h"
56		#endif
57
58		/*
59		* Set the encoding.
60		*/
61		#ifdef _WIN32
62		/*
63		* True if we should use UTF-8.
64		*/
65		static int use_utf_8;
66
67		void
68		pcapint_fmt_set_encoding(unsigned int opts)
69		{
70		if (opts == PCAP_CHAR_ENC_UTF_8)
71		use_utf_8 = 1;
72		}
73		#else
74		void
75		pcapint_fmt_set_encoding(unsigned int opts _U_)
76	0	{
77		/*
78		* Nothing to do here.
79		*/
80	0	}
81		#endif
82
83		#ifdef _WIN32
84		/*
85		* Convert a null-terminated UTF-16LE string to UTF-8, putting it into
86		* a buffer starting at the specified location and stopping if we go
87		* past the specified size. This will only put out complete UTF-8
88		* sequences.
89		*
90		* We do this ourselves because Microsoft doesn't offer a "convert and
91		* stop at a UTF-8 character boundary if we run out of space" routine.
92		*/
93		#define IS_LEADING_SURROGATE(c) \
94		((c) >= 0xd800 && (c) < 0xdc00)
95		#define IS_TRAILING_SURROGATE(c) \
96		((c) >= 0xdc00 && (c) < 0xe000)
97		#define SURROGATE_VALUE(leading, trailing) \
98		(((((leading) - 0xd800) << 10) \| ((trailing) - 0xdc00)) + 0x10000)
99		#define REPLACEMENT_CHARACTER 0x0FFFD
100
101		static char *
102		utf_16le_to_utf_8_truncated(const wchar_t utf_16, char utf_8,
103		size_t utf_8_len)
104		{
105		wchar_t c, c2;
106		uint32_t uc;
107
108		if (utf_8_len == 0) {
109		/*
110		* Not even enough room for a trailing '\0'.
111		* Don't put anything into the buffer.
112		*/
113		return (utf_8);
114		}
115
116		while ((c = *utf_16++) != '\0') {
117		if (IS_LEADING_SURROGATE(c)) {
118		/*
119		* Leading surrogate. Must be followed by
120		* a trailing surrogate.
121		*/
122		c2 = *utf_16;
123		if (c2 == '\0') {
124		/*
125		* Oops, string ends with a lead
126		* surrogate. Try to drop in
127		* a REPLACEMENT CHARACTER, and
128		* don't move the string pointer,
129		* so on the next trip through
130		* the loop we grab the terminating
131		* '\0' and quit.
132		*/
133		uc = REPLACEMENT_CHARACTER;
134		} else {
135		/*
136		* OK, we can consume this 2-octet
137		* value.
138		*/
139		utf_16++;
140		if (IS_TRAILING_SURROGATE(c2)) {
141		/*
142		* Trailing surrogate.
143		* This calculation will,
144		* for c being a leading
145		* surrogate and c2 being
146		* a trailing surrogate,
147		* produce a value between
148		* 0x100000 and 0x10ffff,
149		* so it's always going to be
150		* a valid Unicode code point.
151		*/
152		uc = SURROGATE_VALUE(c, c2);
153		} else {
154		/*
155		* Not a trailing surrogate;
156		* try to drop in a
157		* REPLACEMENT CHARACTER.
158		*/
159		uc = REPLACEMENT_CHARACTER;
160		}
161		}
162		} else {
163		/*
164		* Not a leading surrogate.
165		*/
166		if (IS_TRAILING_SURROGATE(c)) {
167		/*
168		* Trailing surrogate without
169		* a preceding leading surrogate.
170		* Try to drop in a REPLACEMENT
171		* CHARACTER.
172		*/
173		uc = REPLACEMENT_CHARACTER;
174		} else {
175		/*
176		* This is a valid BMP character;
177		* drop it in.
178		*/
179		uc = c;
180		}
181		}
182
183		/*
184		* OK, uc is a valid Unicode character; how
185		* many bytes worth of UTF-8 does it require?
186		*/
187		if (uc < 0x0080) {
188		/* 1 byte. */
189		if (utf_8_len < 2) {
190		/*
191		* Not enough room for that byte
192		* plus a trailing '\0'.
193		*/
194		break;
195		}
196		*utf_8++ = (char)uc;
197		utf_8_len--;
198		} else if (uc < 0x0800) {
199		/* 2 bytes. */
200		if (utf_8_len < 3) {
201		/*
202		* Not enough room for those bytes
203		* plus a trailing '\0'.
204		*/
205		break;
206		}
207		*utf_8++ = ((uc >> 6) & 0x3F) \| 0xC0;
208		*utf_8++ = ((uc >> 0) & 0x3F) \| 0x80;
209		utf_8_len -= 2;
210		} else if (uc < 0x010000) {
211		/* 3 bytes. */
212		if (utf_8_len < 4) {
213		/*
214		* Not enough room for those bytes
215		* plus a trailing '\0'.
216		*/
217		break;
218		}
219		*utf_8++ = ((uc >> 12) & 0x0F) \| 0xE0;
220		*utf_8++ = ((uc >> 6) & 0x3F) \| 0x80;
221		*utf_8++ = ((uc >> 0) & 0x3F) \| 0x80;
222		utf_8_len -= 3;
223		} else {
224		/* 4 bytes. */
225		if (utf_8_len < 5) {
226		/*
227		* Not enough room for those bytes
228		* plus a trailing '\0'.
229		*/
230		break;
231		}
232		*utf_8++ = ((uc >> 18) & 0x03) \| 0xF0;
233		*utf_8++ = ((uc >> 12) & 0x3F) \| 0x80;
234		*utf_8++ = ((uc >> 6) & 0x3F) \| 0x80;
235		*utf_8++ = ((uc >> 0) & 0x3F) \| 0x80;
236		utf_8_len -= 3;
237		}
238		}
239
240		/*
241		* OK, we have enough room for (at least) a trailing '\0'.
242		* (We started out with enough room, thanks to the test
243		* for a zero-length buffer at the beginning, and if
244		* there wasn't enough room for any character we wanted
245		* to put into the buffer plus a trailing '\0',
246		* we'd have quit before putting it into the buffer,
247		* and thus would have left enough room for the trailing
248		* '\0'.)
249		*
250		* Drop it in.
251		*/
252		*utf_8 = '\0';
253
254		/*
255		* Return a pointer to the terminating '\0', in case we
256		* want to drop something in after that.
257		*/
258		return (utf_8);
259		}
260		#endif /* _WIN32 */
261
262		/*
263		* Generate an error message based on a format, arguments, and an
264		* errno, with a message for the errno after the formatted output.
265		*/
266		void
267		pcapint_fmt_errmsg_for_errno(char *errbuf, size_t errbuflen, int errnum,
268		const char *fmt, ...)
269	0	{
270	0	va_list ap;
271
272	0	va_start(ap, fmt);
273	0	pcapint_vfmt_errmsg_for_errno(errbuf, errbuflen, errnum, fmt, ap);
274	0	va_end(ap);
275	0	}
276
277		void
278		pcapint_vfmt_errmsg_for_errno(char *errbuf, size_t errbuflen, int errnum,
279		const char *fmt, va_list ap)
280	0	{
281	0	size_t msglen;
282	0	char *p;
283	0	size_t errbuflen_remaining;
284
285	0	(void)vsnprintf(errbuf, errbuflen, fmt, ap);
286	0	msglen = strlen(errbuf);
287
288		/*
289		* Do we have enough space to append ": "?
290		* Including the terminating '\0', that's 3 bytes.
291		*/
292	0	if (msglen + 3 > errbuflen) {
293		/* No - just give them what we've produced. */
294	0	return;
295	0	}
296	0	p = errbuf + msglen;
297	0	errbuflen_remaining = errbuflen - msglen;
298	0	*p++ = ':';
299	0	*p++ = ' ';
300	0	*p = '\0';
301	0	errbuflen_remaining -= 2;
302
303		/*
304		* Now append the string for the error code.
305		*/
306		#if defined(HAVE__WCSERROR_S)
307		/*
308		* We have a Windows-style _wcserror_s().
309		* Generate a UTF-16LE error message.
310		*/
311		wchar_t utf_16_errbuf[PCAP_ERRBUF_SIZE];
312		errno_t err = _wcserror_s(utf_16_errbuf, PCAP_ERRBUF_SIZE, errnum);
313		if (err != 0) {
314		/*
315		* It doesn't appear to be documented anywhere obvious
316		* what the error returns from _wcserror_s().
317		*/
318		snprintf(p, errbuflen_remaining, "Error %d", errnum);
319		return;
320		}
321
322		/*
323		* Now convert it from UTF-16LE to UTF-8, dropping it in the
324		* remaining space in the buffer, and truncating it - cleanly,
325		* on a UTF-8 character boundary - if it doesn't fit.
326		*/
327		utf_16le_to_utf_8_truncated(utf_16_errbuf, p, errbuflen_remaining);
328
329		/*
330		* Now, if we're not in UTF-8 mode, convert errbuf to the
331		* local code page.
332		*/
333		if (!use_utf_8)
334		utf_8_to_acp_truncated(errbuf);
335		#else
336		/*
337		* Either Windows without _wcserror_s() or not Windows. Let pcap_strerror()
338		* solve the non-UTF-16 part of this problem space.
339		*/
340	0	snprintf(p, errbuflen_remaining, "%s", pcap_strerror(errnum));
341	0	#endif
342	0	}
343
344		#ifdef _WIN32
345		/*
346		* Generate an error message based on a format, arguments, and a
347		* Win32 error, with a message for the Win32 error after the formatted output.
348		*/
349		void
350		pcapint_fmt_errmsg_for_win32_err(char *errbuf, size_t errbuflen, DWORD errnum,
351		const char *fmt, ...)
352		{
353		va_list ap;
354
355		va_start(ap, fmt);
356		pcapint_vfmt_errmsg_for_win32_err(errbuf, errbuflen, errnum, fmt, ap);
357		va_end(ap);
358		}
359
360		void
361		pcapint_vfmt_errmsg_for_win32_err(char *errbuf, size_t errbuflen, DWORD errnum,
362		const char *fmt, va_list ap)
363		{
364		size_t msglen;
365		char *p;
366		size_t errbuflen_remaining;
367		DWORD retval;
368		wchar_t utf_16_errbuf[PCAP_ERRBUF_SIZE];
369		size_t utf_8_len;
370
371		vsnprintf(errbuf, errbuflen, fmt, ap);
372		msglen = strlen(errbuf);
373
374		/*
375		* Do we have enough space to append ": "?
376		* Including the terminating '\0', that's 3 bytes.
377		*/
378		if (msglen + 3 > errbuflen) {
379		/* No - just give them what we've produced. */
380		return;
381		}
382		p = errbuf + msglen;
383		errbuflen_remaining = errbuflen - msglen;
384		*p++ = ':';
385		*p++ = ' ';
386		*p = '\0';
387		msglen += 2;
388		errbuflen_remaining -= 2;
389
390		/*
391		* Now append the string for the error code.
392		*
393		* XXX - what language ID to use?
394		*
395		* For UN*Xes, pcap_strerror() may or may not return localized
396		* strings.
397		*
398		* We currently don't have localized messages for libpcap, but
399		* we might want to do so. On the other hand, if most of these
400		* messages are going to be read by libpcap developers and
401		* perhaps by developers of libpcap-based applications, English
402		* might be a better choice, so the developer doesn't have to
403		* get the message translated if it's in a language they don't
404		* happen to understand.
405		*/
406		retval = FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM\|FORMAT_MESSAGE_IGNORE_INSERTS\|FORMAT_MESSAGE_MAX_WIDTH_MASK,
407		NULL, errnum, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
408		utf_16_errbuf, PCAP_ERRBUF_SIZE, NULL);
409		if (retval == 0) {
410		/*
411		* Failed.
412		*/
413		snprintf(p, errbuflen_remaining,
414		"Couldn't get error message for error (%lu)", errnum);
415		return;
416		}
417
418		/*
419		* Now convert it from UTF-16LE to UTF-8.
420		*/
421		p = utf_16le_to_utf_8_truncated(utf_16_errbuf, p, errbuflen_remaining);
422
423		/*
424		* Now append the error number, if it fits.
425		*/
426		utf_8_len = p - errbuf;
427		errbuflen_remaining -= utf_8_len;
428		if (utf_8_len == 0) {
429		/* The message was empty. */
430		snprintf(p, errbuflen_remaining, "(%lu)", errnum);
431		} else
432		snprintf(p, errbuflen_remaining, " (%lu)", errnum);
433
434		/*
435		* Now, if we're not in UTF-8 mode, convert errbuf to the
436		* local code page.
437		*/
438		if (!use_utf_8)
439		utf_8_to_acp_truncated(errbuf);
440		}
441		#endif