X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/7b2c5a11a7bc236d72b440c4db5263edb23b4880..69cb46af9119e8b5554bcc4bf1bf36f39cb82131:/print-vjc.c?ds=inline

diff --git a/print-vjc.c b/print-vjc.c
index fc7aafa9..65aa8e6a 100644
--- a/print-vjc.c
+++ b/print-vjc.c
@@ -70,6 +70,13 @@
  * We therefore leave "proto" - which is the PPP protocol type - in place,
  * *not* marked as unused, for now, so that GCC warnings about the
  * unused argument remind us that we should fix this some day.
+ *
+ * XXX - also, it fetches the TCP checksum field in COMPRESSED_TCP
+ * packets directly, rather than with EXTRACT_16BITS(); RFC 1144 says
+ * it's "the unmodified TCP checksum", which would imply that it's
+ * big-endian, but perhaps, on the platform where this was developed,
+ * the packets were munged by the networking stack before being handed
+ * to the packet capture mechanism.
  */
 int
 vjc_print(netdissect_options *ndo, register const char *bp, u_short proto _U_)
@@ -95,7 +102,7 @@ vjc_print(netdissect_options *ndo, register const char *bp, u_short proto _U_)
 		if (bp[1])
 			ND_PRINT((ndo, " "));
 		ND_PRINT((ndo, "C=0x%02x ", bp[2]));
-		ND_PRINT((ndo, "sum=0x%04x ", *(u_short *)&bp[3]));
+		ND_PRINT((ndo, "sum=0x%04x ", *(const u_short *)&bp[3]));
 		return -1;
 	case TYPE_ERROR:
 		if (ndo->ndo_eflag)