X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/ad7a38341c19e71e3595c17368ac18f08b71482d..a8abce5c5e2dce2ba6dbccd5d3829da104b80f9c:/print-udld.c

diff --git a/print-udld.c b/print-udld.c
index c0fc793c..224d4825 100644
--- a/print-udld.c
+++ b/print-udld.c
@@ -12,25 +12,22 @@
  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE.
  *
- * UNIDIRECTIONAL LINK DETECTION (UDLD) as per
- * http://www.ietf.org/internet-drafts/draft-foschiano-udld-02.txt
- *
  * Original code by Carles Kishimoto <carles.kishimoto@gmail.com>
  */
 
+/* \summary: Cisco UniDirectional Link Detection (UDLD) protocol printer */
+
+/* specification: RFC 5171 */
+
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
-#include <tcpdump-stdinc.h>
-
-#include <stdio.h>
-#include <string.h>
+#include "netdissect-stdinc.h"
 
-#include "interface.h"
-#include "addrtoname.h"
+#include "netdissect.h"
 #include "extract.h"
-#include "nlpid.h"
+
 
 #define UDLD_HEADER_LEN			4
 #define UDLD_DEVICE_ID_TLV		0x0001
@@ -67,9 +64,10 @@ static const struct tok udld_flags_values[] = {
 };
 
 /*
+ * UDLD's Protocol Data Unit format:
  *
- * 0                   1                   2                   3
- * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  0                   1                   2                   3
+ *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  * | Ver | Opcode  |     Flags     |           Checksum            |
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
@@ -77,80 +75,104 @@ static const struct tok udld_flags_values[] = {
  * |                              ...                              |
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  *
+ * TLV format:
+ *
+ *  0                   1                   2                   3
+ *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |             TYPE              |            LENGTH             |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                             VALUE                             |
+ * |                              ...                              |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * LENGTH: Length in bytes of the Type, Length, and Value fields.
  */
 
 #define	UDLD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
 #define	UDLD_EXTRACT_OPCODE(x) ((x)&0x1f)
 
 void
-udld_print (const u_char *pptr, u_int length)
+udld_print(netdissect_options *ndo, const u_char *pptr, u_int length)
 {
     int code, type, len;
     const u_char *tptr;
 
+    ndo->ndo_protocol = "udld";
     if (length < UDLD_HEADER_LEN)
         goto trunc;
 
     tptr = pptr;
 
-    if (!TTEST2(*tptr, UDLD_HEADER_LEN))
-	goto trunc;
+    ND_TCHECK_LEN(tptr, UDLD_HEADER_LEN);
 
-    code = UDLD_EXTRACT_OPCODE(*tptr);
+    code = UDLD_EXTRACT_OPCODE(EXTRACT_U_1(tptr));
 
-    printf("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u",
-           UDLD_EXTRACT_VERSION(*tptr),
+    ND_PRINT("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u",
+           UDLD_EXTRACT_VERSION(EXTRACT_U_1(tptr)),
            tok2str(udld_code_values, "Reserved", code),
            code,
-           bittok2str(udld_flags_values, "none", *(tptr+1)),
-           *(tptr+1),
+           bittok2str(udld_flags_values, "none", EXTRACT_U_1((tptr + 1))),
+           EXTRACT_U_1((tptr + 1)),
            length);
 
     /*
      * In non-verbose mode, just print version and opcode type
      */
-    if (vflag < 1) {
+    if (ndo->ndo_vflag < 1) {
 	return;
     }
 
-    printf("\n\tChecksum 0x%04x (unverified)", EXTRACT_16BITS(tptr+2));
+    ND_PRINT("\n\tChecksum 0x%04x (unverified)", EXTRACT_BE_U_2(tptr + 2));
 
     tptr += UDLD_HEADER_LEN;
 
     while (tptr < (pptr+length)) {
 
-        if (!TTEST2(*tptr, 4))
-            goto trunc;
+        ND_TCHECK_4(tptr);
+	type = EXTRACT_BE_U_2(tptr);
+        len  = EXTRACT_BE_U_2(tptr + 2);
 
-	type = EXTRACT_16BITS(tptr);
-        len  = EXTRACT_16BITS(tptr+2);
-        len -= 4;
-        tptr += 4;
+        ND_PRINT("\n\t%s (0x%04x) TLV, length %u",
+               tok2str(udld_tlv_values, "Unknown", type),
+               type, len);
+
+        if (type == 0)
+            goto invalid;
 
         /* infinite loop check */
-        if (type == 0 || len == 0) {
-            return;
-        }
+        if (len <= 4)
+            goto invalid;
 
-        printf("\n\t%s (0x%04x) TLV, length %u",
-               tok2str(udld_tlv_values, "Unknown", type),
-               type, len);
+        len -= 4;
+        tptr += 4;
+
+        ND_TCHECK_LEN(tptr, len);
 
         switch (type) {
         case UDLD_DEVICE_ID_TLV:
         case UDLD_PORT_ID_TLV:
-        case UDLD_ECHO_TLV:
         case UDLD_DEVICE_NAME_TLV:
-            printf(", %s", tptr);
+            ND_PRINT(", ");
+            nd_printzp(ndo, tptr, len, NULL);
+            break;
+
+        case UDLD_ECHO_TLV:
+            ND_PRINT(", ");
+            (void)nd_printn(ndo, tptr, len, NULL);
             break;
 
         case UDLD_MESSAGE_INTERVAL_TLV:
         case UDLD_TIMEOUT_INTERVAL_TLV:
-            printf(", %us", (*tptr));
+            if (len != 1)
+                goto invalid;
+            ND_PRINT(", %us", (EXTRACT_U_1(tptr)));
             break;
 
         case UDLD_SEQ_NUMBER_TLV:
-            printf(", %u", EXTRACT_32BITS(tptr));
+            if (len != 4)
+                goto invalid;
+            ND_PRINT(", %u", EXTRACT_BE_U_4(tptr));
             break;
 
         default:
@@ -161,13 +183,9 @@ udld_print (const u_char *pptr, u_int length)
 
     return;
 
- trunc:
-    printf("[|udld]");
+invalid:
+    ND_PRINT("%s", istr);
+    return;
+trunc:
+    nd_print_trunc(ndo);
 }
-
-/*
- * Local Variables:
- * c-style: whitesmith
- * c-basic-offset: 4
- * End:
- */