Don't directly fetch multi-byte integers from packets.

Use the EXTRACT_ macros to extract multi-byte integral values from
packets, rather than just dereferencing pointers into the packet; there
is no guarantee that the packet data will be aligned on the right
boundary, and there is no guarantee that, if they're not, a direct
access will work correctly.

diff --git a/token.h b/token.h
index b1d92a3f1a170a1182080849e368f90b207e3f65..73a82711544c4b508faebea6129fe2b9e4dd40e0 100644 (file)
--- a/token.h
+++ b/token.h
@@ -34,12 +34,12 @@
 #define FRAME_TYPE(trp)                (((trp)->token_fc & 0xC0) >> 6)
 #define TOKEN_FC_LLC           1
 
-#define BROADCAST(trp)         ((ntohs((trp)->token_rcf) & 0xE000) >> 13)
-#define RIF_LENGTH(trp)                ((ntohs((trp)->token_rcf) & 0x1f00) >> 8)
-#define DIRECTION(trp)         ((ntohs((trp)->token_rcf) & 0x0080) >> 7)
-#define LARGEST_FRAME(trp)     ((ntohs((trp)->token_rcf) & 0x0070) >> 4)
-#define RING_NUMBER(trp, x)    ((ntohs((trp)->token_rseg[x]) & 0xfff0) >> 4)
-#define BRIDGE_NUMBER(trp, x)  ((ntohs((trp)->token_rseg[x]) & 0x000f))
+#define BROADCAST(trp)         ((EXTRACT_16BITS(&(trp)->token_rcf) & 0xE000) >> 13)
+#define RIF_LENGTH(trp)                ((EXTRACT_16BITS(&(trp)->token_rcf) & 0x1f00) >> 8)
+#define DIRECTION(trp)         ((EXTRACT_16BITS(&(trp)->token_rcf) & 0x0080) >> 7)
+#define LARGEST_FRAME(trp)     ((EXTRACT_16BITS(&(trp)->token_rcf) & 0x0070) >> 4)
+#define RING_NUMBER(trp, x)    ((EXTRACT_16BITS(&(trp)->token_rseg[x]) & 0xfff0) >> 4)
+#define BRIDGE_NUMBER(trp, x)  ((EXTRACT_16BITS(&(trp)->token_rseg[x]) & 0x000f))
 #define SEGMENT_COUNT(trp)     ((int)((RIF_LENGTH(trp) - 2) / 2))
 
 struct token_header {