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 #ifdef HAVE_CONFIG_H
39 #include <config.h>
40 #endif
41
42 #include "ftmacros.h"
43
44 #include <stddef.h>
45 #include <stdarg.h>
46 #include <stdio.h>
47 #include <string.h>
48 #include <errno.h>
49
50 #include <pcap/pcap.h>
51
52 #include "portability.h"
53
54 #include "fmtutils.h"
55
56 /*
57 * Generate an error message based on a format, arguments, and an
58 * errno, with a message for the errno after the formatted output.
59 */
60 void
pcap_fmt_errmsg_for_errno(char * errbuf,size_t errbuflen,int errnum,const char * fmt,...)61 pcap_fmt_errmsg_for_errno(char *errbuf, size_t errbuflen, int errnum,
62 const char *fmt, ...)
63 {
64 va_list ap;
65 size_t msglen;
66 char *p;
67 size_t errbuflen_remaining;
68
69 va_start(ap, fmt);
70 pcap_vsnprintf(errbuf, errbuflen, fmt, ap);
71 va_end(ap);
72 msglen = strlen(errbuf);
73
74 /*
75 * Do we have enough space to append ": "?
76 * Including the terminating '\0', that's 3 bytes.
77 */
78 if (msglen + 3 > errbuflen) {
79 /* No - just give them what we've produced. */
80 return;
81 }
82 p = errbuf + msglen;
83 errbuflen_remaining = errbuflen - msglen;
84 *p++ = ':';
85 *p++ = ' ';
86 *p = '\0';
87 msglen += 2;
88 errbuflen_remaining -= 2;
89
90 /*
91 * Now append the string for the error code.
92 */
93 #if defined(HAVE_STRERROR_S)
94 /*
95 * We have a Windows-style strerror_s().
96 */
97 errno_t err = strerror_s(p, errbuflen_remaining, errnum);
98 if (err != 0) {
99 /*
100 * It doesn't appear to be documented anywhere obvious
101 * what the error returns from strerror_s().
102 */
103 pcap_snprintf(p, errbuflen_remaining, "Error %d", errnum);
104 }
105 #elif defined(HAVE_GNU_STRERROR_R)
106 /*
107 * We have a GNU-style strerror_r(), which is *not* guaranteed to
108 * do anything to the buffer handed to it, and which returns a
109 * pointer to the error string, which may or may not be in
110 * the buffer.
111 *
112 * It is, however, guaranteed to succeed.
113 */
114 char strerror_buf[PCAP_ERRBUF_SIZE];
115 char *errstring = strerror_r(errnum, strerror_buf, PCAP_ERRBUF_SIZE);
116 pcap_snprintf(p, errbuflen_remaining, "%s", errstring);
117 #elif defined(HAVE_POSIX_STRERROR_R)
118 /*
119 * We have a POSIX-style strerror_r(), which is guaranteed to fill
120 * in the buffer, but is not guaranteed to succeed.
121 */
122 int err = strerror_r(errnum, p, errbuflen_remaining);
123 if (err == EINVAL) {
124 /*
125 * UNIX 03 says this isn't guaranteed to produce a
126 * fallback error message.
127 */
128 pcap_snprintf(p, errbuflen_remaining, "Unknown error: %d",
129 errnum);
130 } else if (err == ERANGE) {
131 /*
132 * UNIX 03 says this isn't guaranteed to produce a
133 * fallback error message.
134 */
135 pcap_snprintf(p, errbuflen_remaining,
136 "Message for error %d is too long", errnum);
137 }
138 #else
139 /*
140 * We have neither strerror_s() nor strerror_r(), so we're
141 * stuck with using pcap_strerror().
142 */
143 pcap_snprintf(p, errbuflen_remaining, "%s", pcap_strerror(errnum));
144 #endif
145 }
146
147 #ifdef _WIN32
148 /*
149 * Generate an error message based on a format, arguments, and a
150 * Win32 error, with a message for the Win32 error after the formatted output.
151 */
152 void
pcap_fmt_errmsg_for_win32_err(char * errbuf,size_t errbuflen,DWORD errnum,const char * fmt,...)153 pcap_fmt_errmsg_for_win32_err(char *errbuf, size_t errbuflen, DWORD errnum,
154 const char *fmt, ...)
155 {
156 va_list ap;
157 size_t msglen;
158 char *p;
159 size_t errbuflen_remaining;
160 DWORD retval;
161 char win32_errbuf[PCAP_ERRBUF_SIZE+1];
162
163 va_start(ap, fmt);
164 pcap_vsnprintf(errbuf, errbuflen, fmt, ap);
165 va_end(ap);
166 msglen = strlen(errbuf);
167
168 /*
169 * Do we have enough space to append ": "?
170 * Including the terminating '\0', that's 3 bytes.
171 */
172 if (msglen + 3 > errbuflen) {
173 /* No - just give them what we've produced. */
174 return;
175 }
176 p = errbuf + msglen;
177 errbuflen_remaining = errbuflen - msglen;
178 *p++ = ':';
179 *p++ = ' ';
180 *p = '\0';
181 msglen += 2;
182 errbuflen_remaining -= 2;
183
184 /*
185 * Now append the string for the error code.
186 *
187 * XXX - what language ID to use?
188 *
189 * For UN*Xes, pcap_strerror() may or may not return localized
190 * strings.
191 *
192 * We currently don't have localized messages for libpcap, but
193 * we might want to do so. On the other hand, if most of these
194 * messages are going to be read by libpcap developers and
195 * perhaps by developers of libpcap-based applications, English
196 * might be a better choice, so the developer doesn't have to
197 * get the message translated if it's in a language they don't
198 * happen to understand.
199 */
200 retval = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS|FORMAT_MESSAGE_MAX_WIDTH_MASK,
201 NULL, errnum, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
202 win32_errbuf, PCAP_ERRBUF_SIZE, NULL);
203 if (retval == 0) {
204 /*
205 * Failed.
206 */
207 pcap_snprintf(p, errbuflen_remaining,
208 "Couldn't get error message for error (%lu)", errnum);
209 return;
210 }
211
212 pcap_snprintf(p, errbuflen_remaining, "%s (%lu)", win32_errbuf, errnum);
213 }
214 #endif
215