On most systems, bit-swap the bytes of an FDDI MAC address. (List of

systems on which you don't bit-swap them taken from "tcpdump"; the list
may not be complete.)

svn path=/trunk/; revision=48

1 files changed, 67 insertions, 8 deletions

diff --git a/packet-fddi.c b/packet-fddi.c
index 45f3256b1e..51ad3df218 100644
--- a/packet-fddi.c
+++ b/packet-fddi.c
@@ -3,7 +3,7 @@
  *
  * Laurent Deniel <deniel@worldnet.fr>
  *
- * $Id: packet-fddi.c,v 1.4 1998/10/13 05:55:45 guy Exp $
+ * $Id: packet-fddi.c,v 1.5 1998/10/13 07:48:03 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -74,22 +74,83 @@
 #define FDDI_P_DHOST		1
 #define FDDI_P_SHOST		7
 
-void dissect_fddi(const u_char *pd, frame_data *fd, GtkTree *tree) 
+/* On some systems, the FDDI MAC addresses are bit-swapped. */
+#if !defined(ultrix) && !defined(__alpha) && !defined(__bsdi)
+#define BIT_SWAPPED_MAC_ADDRS
+#endif
+
+#ifdef BIT_SWAPPED_MAC_ADDRS
+/* "swaptab[i]" is the value of "i" with the bits reversed. */
+static u_char swaptab[256] = {
+  0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
+  0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
+  0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
+  0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
+  0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
+  0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
+  0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
+  0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
+  0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
+  0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
+  0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
+  0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
+  0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
+  0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
+  0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
+  0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
+  0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
+  0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
+  0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
+  0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
+  0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
+  0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
+  0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
+  0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
+  0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
+  0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
+  0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
+  0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
+  0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
+  0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
+  0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
+  0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff,
+};
+#endif
+
+static void get_mac_addr(u_char *swapped_addr, const u_char *addr)
 {
+  int i;
 
+  for (i = 0; i < 6; i++) {
+#ifdef BIT_SWAPPED_MAC_ADDRS
+    swapped_addr[i] = swaptab[addr[i]];
+#else
+    swapped_addr[i] = addr[i];
+#endif
+  }
+}
+
+void dissect_fddi(const u_char *pd, frame_data *fd, GtkTree *tree) 
+{
   int        offset = 0, fc;
   GtkWidget *fh_tree, *ti;
+  u_char     src[6], dst[6];
 
   if (fd->cap_len < FDDI_HEADER_SIZE) {
     dissect_data(pd, offset, fd, tree);
     return;
   }
 
+  /* Extract the source and destination addresses, possibly bit-swapping
+     them. */
+  get_mac_addr(dst, (u_char *)&pd[FDDI_P_DHOST]);
+  get_mac_addr(src, (u_char *)&pd[FDDI_P_SHOST]);
+
   fc = (int) pd[FDDI_P_FC];
 
   if (fd->win_info[COL_NUM]) {
-    strcpy(fd->win_info[COL_DESTINATION], get_ether_name((u_char *)&pd[FDDI_P_DHOST]));
-    strcpy(fd->win_info[COL_SOURCE], get_ether_name((u_char *)&pd[FDDI_P_SHOST]));
+    strcpy(fd->win_info[COL_DESTINATION], get_ether_name(dst));
+    strcpy(fd->win_info[COL_SOURCE], get_ether_name(src));
     strcpy(fd->win_info[COL_INFO], "FDDI");
   }
 
@@ -103,11 +164,9 @@ void dissect_fddi(const u_char *pd, frame_data *fd, GtkTree *tree)
       add_subtree(ti, fh_tree, ETT_FDDI);
       add_item_to_tree(fh_tree, FDDI_P_FC, 1, "Frame Control: 0x%02x", fc);
       add_item_to_tree(fh_tree, FDDI_P_DHOST, 6, "Destination: %s (%s)",
-		       ether_to_str((guint8 *) &pd[FDDI_P_DHOST]),
-		       get_ether_name((u_char *) &pd[FDDI_P_DHOST]));
+		       ether_to_str(dst), get_ether_name(dst));
       add_item_to_tree(fh_tree, FDDI_P_SHOST, 6, "Source: %s (%s)",
-		       ether_to_str((guint8 *) &pd[FDDI_P_SHOST]),
-		       get_ether_name((u_char *)&pd[FDDI_P_SHOST]));
+		       ether_to_str(src), get_ether_name(src));
     }
 
   offset = FDDI_HEADER_SIZE;