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 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 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