Handle older OSes without DLT_PRISM_HEADER/DLT_AIRONET_HEADER/DLT_PPI.

[libpcap] / fmtutils.c

diff --git a/fmtutils.c b/fmtutils.c
index f1a8907327deb5e34083110d9ec0a838e2d0150a..0c527453547f2c2e68d60518f9d070a22b3c6db6 100644 (file)
--- a/fmtutils.c
+++ b/fmtutils.c
@@ -129,3 +129,59 @@ pcap_fmt_errmsg_for_errno(char *errbuf, size_t errbuflen, int errnum,
        pcap_snprintf(p, errbuflen_remaining, "%s", pcap_strerror(errnum));
 #endif
 }
+
+#ifdef _WIN32
+/*
+ * Generate a string for a Win32-specific error (i.e. an error generated when
+ * calling a Win32 API).
+ * For errors occurred during standard C calls, we still use pcap_strerror().
+ */
+void
+pcap_win32_err_to_str(DWORD error, char *errbuf)
+{
+       DWORD retval;
+       size_t errlen;
+       char *p;
+
+       /*
+        * 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, error, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+           errbuf, PCAP_ERRBUF_SIZE, NULL);
+       if (retval == 0) {
+               /*
+                * Failed.
+                */
+               pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                   "Couldn't get error message for error (%lu)", error);
+               return;
+       }
+
+       /*
+        * "FormatMessage()" "helpfully" sticks CR/LF at the end of the
+        * message.  Get rid of it.
+        *
+        * XXX - still true with FORMAT_MESSAGE_MAX_WIDTH_MASK?
+        */
+       errlen = strlen(errbuf);
+       if (errlen >= 2 &&
+           errbuf[errlen - 2] == '\r' && errbuf[errlen - 1] == '\n') {
+               errbuf[errlen - 2] = '\0';
+               errbuf[errlen - 1] = '\0';
+       }
+       p = strchr(errbuf, '\0');
+       pcap_snprintf(p, PCAP_ERRBUF_SIZE+1-(p-errbuf), " (%lu)", error);
+}
+#endif