X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/7bf069c2517690262aacbddc437731af991b31a7..de0c7fc746c37eb83e15a6890d30dc6f608e9d76:/print-tftp.c

diff --git a/print-tftp.c b/print-tftp.c
index 69bc601f..314dfb41 100644
--- a/print-tftp.c
+++ b/print-tftp.c
@@ -46,21 +46,6 @@
 #define	TFTP_ERROR	05			/* error code */
 #define OACK	06			/* option acknowledgement */
 
-struct	tftphdr {
-	unsigned short	th_opcode;		/* packet type */
-	union {
-		unsigned short	tu_block;	/* block # */
-		unsigned short	tu_code;	/* error code */
-		char	tu_stuff[1];	/* request packet stuff */
-	} th_u;
-	char	th_data[1];		/* data or error string */
-};
-
-#define	th_block	th_u.tu_block
-#define	th_code		th_u.tu_code
-#define	th_stuff	th_u.tu_stuff
-#define	th_msg		th_data
-
 /*
  * Error codes.
  */
@@ -106,80 +91,75 @@ void
 tftp_print(netdissect_options *ndo,
            register const u_char *bp, u_int length)
 {
-	register const struct tftphdr *tp;
 	register const char *cp;
-	register const u_char *p;
 	register int opcode;
 	u_int ui;
 
-	tp = (const struct tftphdr *)bp;
-
 	/* Print length */
 	ND_PRINT((ndo, " %d", length));
 
 	/* Print tftp request type */
 	if (length < 2)
 		goto trunc;
-	ND_TCHECK(tp->th_opcode);
-	opcode = EXTRACT_16BITS(&tp->th_opcode);
+	ND_TCHECK_2(bp);
+	opcode = EXTRACT_BE_U_2(bp);
 	cp = tok2str(op2str, "tftp-#%d", opcode);
-	length -= 2;
 	ND_PRINT((ndo, " %s", cp));
 	/* Bail if bogus opcode */
 	if (*cp == 't')
 		return;
+	bp += 2;
+	length -= 2;
 
 	switch (opcode) {
 
 	case RRQ:
 	case WRQ:
-		p = (const u_char *)tp->th_stuff;
 		if (length == 0)
 			goto trunc;
 		ND_PRINT((ndo, " "));
 		/* Print filename */
 		ND_PRINT((ndo, "\""));
-		ui = fn_printztn(ndo, p, length, ndo->ndo_snapend);
+		ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
 		ND_PRINT((ndo, "\""));
 		if (ui == 0)
 			goto trunc;
-		p += ui;
+		bp += ui;
 		length -= ui;
 
 		/* Print the mode - RRQ and WRQ only */
 		if (length == 0)
 			goto trunc;	/* no mode */
 		ND_PRINT((ndo, " "));
-		ui = fn_printztn(ndo, p, length, ndo->ndo_snapend);
+		ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
 		if (ui == 0)
 			goto trunc;
-		p += ui;
+		bp += ui;
 		length -= ui;
 
 		/* Print options, if any */
 		while (length != 0) {
-			ND_TCHECK(*p);
-			if (*p != '\0')
+			ND_TCHECK(*bp);
+			if (*bp != '\0')
 				ND_PRINT((ndo, " "));
-			ui = fn_printztn(ndo, p, length, ndo->ndo_snapend);
+			ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
 			if (ui == 0)
 				goto trunc;
-			p += ui;
+			bp += ui;
 			length -= ui;
 		}
 		break;
 
 	case OACK:
-		p = (const u_char *)tp->th_stuff;
 		/* Print options */
 		while (length != 0) {
-			ND_TCHECK(*p);
-			if (*p != '\0')
+			ND_TCHECK(*bp);
+			if (*bp != '\0')
 				ND_PRINT((ndo, " "));
-			ui = fn_printztn(ndo, p, length, ndo->ndo_snapend);
+			ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
 			if (ui == 0)
 				goto trunc;
-			p += ui;
+			bp += ui;
 			length -= ui;
 		}
 		break;
@@ -188,23 +168,24 @@ tftp_print(netdissect_options *ndo,
 	case DATA:
 		if (length < 2)
 			goto trunc;	/* no block number */
-		ND_TCHECK(tp->th_block);
-		ND_PRINT((ndo, " block %d", EXTRACT_16BITS(&tp->th_block)));
+		ND_TCHECK_2(bp);
+		ND_PRINT((ndo, " block %d", EXTRACT_BE_U_2(bp)));
 		break;
 
 	case TFTP_ERROR:
 		/* Print error code string */
 		if (length < 2)
 			goto trunc;	/* no error code */
-		ND_TCHECK(tp->th_code);
+		ND_TCHECK_2(bp);
 		ND_PRINT((ndo, " %s", tok2str(err2str, "tftp-err-#%d \"",
-				       EXTRACT_16BITS(&tp->th_code))));
+				       EXTRACT_BE_U_2(bp))));
+		bp += 2;
 		length -= 2;
 		/* Print error message string */
 		if (length == 0)
 			goto trunc;	/* no error message */
 		ND_PRINT((ndo, " \""));
-		ui = fn_printztn(ndo, (const u_char *)tp->th_data, length, ndo->ndo_snapend);
+		ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
 		ND_PRINT((ndo, "\""));
 		if (ui == 0)
 			goto trunc;