Upgrade to tcpdump 4.7.4.
Bug: http://b/24902618
Change-Id: I7c3605015d90453b0a8c339b1774e285796f8775
diff --git a/print-loopback.c b/print-loopback.c
new file mode 100644
index 0000000..9a74ae6
--- /dev/null
+++ b/print-loopback.c
@@ -0,0 +1,136 @@
+/*
+ * This module implements decoding of the Loopback Protocol, originally
+ * defined as the Configuration Testing Protocol. It is based on the following
+ * specification:
+ * http://www.mit.edu/people/jhawk/ctp.pdf
+ *
+ * Copyright (c) 2014 The TCPDUMP project
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT HOLDER 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.
+ */
+
+#define NETDISSECT_REWORKED
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <tcpdump-stdinc.h>
+
+#include "interface.h"
+#include "extract.h"
+#include "ether.h"
+#include "addrtoname.h"
+
+static const char tstr[] = " [|loopback]";
+static const char cstr[] = " (corrupt)";
+
+#define LOOPBACK_REPLY 1
+#define LOOPBACK_FWDDATA 2
+
+static const struct tok fcode_str[] = {
+ { LOOPBACK_REPLY, "Reply" },
+ { LOOPBACK_FWDDATA, "Forward Data" },
+ { 0, NULL }
+};
+
+static void
+loopback_message_print(netdissect_options *ndo, const u_char *cp, const u_int len)
+{
+ const u_char *ep = cp + len;
+ uint16_t function;
+
+ if (len < 2)
+ goto corrupt;
+ /* function */
+ ND_TCHECK2(*cp, 2);
+ function = EXTRACT_LE_16BITS(cp);
+ cp += 2;
+ ND_PRINT((ndo, ", %s", tok2str(fcode_str, " invalid (%u)", function)));
+
+ switch (function) {
+ case LOOPBACK_REPLY:
+ if (len < 4)
+ goto corrupt;
+ /* receipt number */
+ ND_TCHECK2(*cp, 2);
+ ND_PRINT((ndo, ", receipt number %u", EXTRACT_LE_16BITS(cp)));
+ cp += 2;
+ /* data */
+ ND_PRINT((ndo, ", data (%u octets)", len - 4));
+ ND_TCHECK2(*cp, len - 4);
+ break;
+ case LOOPBACK_FWDDATA:
+ if (len < 8)
+ goto corrupt;
+ /* forwarding address */
+ ND_TCHECK2(*cp, ETHER_ADDR_LEN);
+ ND_PRINT((ndo, ", forwarding address %s", etheraddr_string(ndo, cp)));
+ cp += ETHER_ADDR_LEN;
+ /* data */
+ ND_PRINT((ndo, ", data (%u octets)", len - 8));
+ ND_TCHECK2(*cp, len - 8);
+ break;
+ default:
+ ND_TCHECK2(*cp, len - 2);
+ break;
+ }
+ return;
+
+corrupt:
+ ND_PRINT((ndo, "%s", cstr));
+ ND_TCHECK2(*cp, ep - cp);
+ return;
+trunc:
+ ND_PRINT((ndo, "%s", tstr));
+}
+
+void
+loopback_print(netdissect_options *ndo, const u_char *cp, const u_int len)
+{
+ const u_char *ep = cp + len;
+ uint16_t skipCount;
+
+ ND_PRINT((ndo, "Loopback"));
+ if (len < 2)
+ goto corrupt;
+ /* skipCount */
+ ND_TCHECK2(*cp, 2);
+ skipCount = EXTRACT_LE_16BITS(cp);
+ cp += 2;
+ ND_PRINT((ndo, ", skipCount %u", skipCount));
+ if (skipCount % 8)
+ ND_PRINT((ndo, " (bogus)"));
+ if (skipCount > len - 2)
+ goto corrupt;
+ loopback_message_print(ndo, cp + skipCount, len - 2 - skipCount);
+ return;
+
+corrupt:
+ ND_PRINT((ndo, "%s", cstr));
+ ND_TCHECK2(*cp, ep - cp);
+ return;
+trunc:
+ ND_PRINT((ndo, "%s", tstr));
+}
+