Fix VoIP VLAN request/assignment, clean up signed vs. unsigned.

0x000f is a query for a VoIP VLAN ID, 0x000e is the reply for that.
0x0010 is a power consumption message.

Display 2-byte VoIP VLAN queries.  Treat 2-byte VoIP VLAN replies as
errors; I've seen the former but not the latter.

Don't use unsigned long for values that fit in an unsigned int.

diff --git a/print-cdp.c b/print-cdp.c
index d07a62fbec32290351fd7f2e315699b417fe6024..1f0f07cd1df0a92182508a5ad7454e72315481d3 100644 (file)
--- a/print-cdp.c
+++ b/print-cdp.c
@@ -62,8 +62,8 @@ static const struct tok cdp_tlv_values[] = {
     { 0x09,             "VTP Management Domain"},
     { 0x0a,             "Native VLAN ID"},
     { 0x0b,             "Duplex"},
-    { 0x0e,             "ATA-186 VoIP VLAN request"},
-    { 0x0f,             "ATA-186 VoIP VLAN assignment"},
+    { 0x0e,             "ATA-186 VoIP VLAN assignment"},
+    { 0x0f,             "ATA-186 VoIP VLAN request"},
     { 0x10,             "power consumption"},
     { 0x11,             "MTU"},
     { 0x12,             "AVVID trust bitmap"},
@@ -86,15 +86,15 @@ static const struct tok cdp_capability_values[] = {
     { 0, NULL }
 };
 
-static int cdp_print_addr(netdissect_options *, const u_char *, int);
-static int cdp_print_prefixes(netdissect_options *, const u_char *, int);
-static unsigned long cdp_get_number(const u_char *, int);
+static int cdp_print_addr(netdissect_options *, const u_char *, u_int);
+static int cdp_print_prefixes(netdissect_options *, const u_char *, u_int);
+static unsigned int cdp_get_number(const u_char *, u_int);
 
 void
 cdp_print(netdissect_options *ndo,
           const u_char *pptr, u_int length, u_int caplen)
 {
-       int type, len, i, j;
+       u_int type, len, i, j;
        const u_char *tptr;
 
        if (caplen < CDP_HEADER_LEN) {
@@ -197,7 +197,7 @@ cdp_print(netdissect_options *ndo,
                    case 0x0a: /* Native VLAN ID - CDPv2 */
                        if (len < 2)
                            goto trunc;
-                       ND_PRINT("%d", EXTRACT_BE_U_2(tptr));
+                       ND_PRINT("%u", EXTRACT_BE_U_2(tptr));
                        break;
                    case 0x0b: /* Duplex - CDPv2 */
                        if (len < 1)
@@ -207,13 +207,30 @@ cdp_print(netdissect_options *ndo,
 
                    /* http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cata/186/2_12_m/english/release/notes/186rn21m.html
                     * plus more details from other sources
+                    *
+                    * There are apparently versions of the request with both
+                    * 2 bytes and 3 bytes of value.  The 3 bytes of value
+                    * appear to be a 1-byte application type followed by a
+                    * 2-byte VLAN ID; the 2 bytes of value are unknown
+                    * (they're 0x20 0x00 in some captures I've seen; that
+                    * is not a valid VLAN ID, as VLAN IDs are 12 bits).
+                    *
+                    * The replies all appear to be 3 bytes long.
                     */
-                   case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
+                   case 0x0e: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
                        if (len < 3)
                            goto trunc;
-                       ND_PRINT("app %d, vlan %d", EXTRACT_U_1((tptr)), EXTRACT_BE_U_2(tptr + 1));
+                       ND_PRINT("app %u, vlan %u", EXTRACT_U_1(tptr), EXTRACT_BE_U_2(tptr + 1));
                        break;
-                   case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
+                   case 0x0f: /* ATA-186 VoIP VLAN request - incomplete doc. */
+                       if (len < 2)
+                           goto trunc;
+                       if (len == 2)
+                           ND_PRINT("unknown 0x%04x", EXTRACT_BE_U_2(tptr));
+                       else
+                           ND_PRINT("app %u, vlan %u", EXTRACT_U_1(tptr), EXTRACT_BE_U_2(tptr + 1));
+                       break;
+                   case 0x10: /* Power - not documented */
                        ND_PRINT("%1.2fW", cdp_get_number(tptr, len) / 1000.0);
                        break;
                    case 0x11: /* MTU - not documented */
@@ -277,9 +294,9 @@ trunc:
 
 static int
 cdp_print_addr(netdissect_options *ndo,
-              const u_char * p, int l)
+              const u_char * p, u_int l)
 {
-       int pt, pl, al, num;
+       u_int pt, pl, al, num;
        const u_char *endp = p + l;
        static const u_char prot_ipv6[] = {
                0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
@@ -291,12 +308,12 @@ cdp_print_addr(netdissect_options *ndo,
        num = EXTRACT_BE_U_4(p);
        p += 4;
 
-       while (p < endp && num >= 0) {
+       while (p < endp && num != 0) {
                ND_TCHECK_2(p);
                if (p + 2 > endp)
                        goto trunc;
                pt = EXTRACT_U_1(p);            /* type of "protocol" field */
-               pl = EXTRACT_U_1(p + 1);                /* length of "protocol" field */
+               pl = EXTRACT_U_1(p + 1);        /* length of "protocol" field */
                p += 2;
 
                ND_TCHECK_2(p + pl);
@@ -342,7 +359,7 @@ cdp_print_addr(netdissect_options *ndo,
                        ND_TCHECK_LEN(p, pl);
                        if (p + pl > endp)
                                goto trunc;
-                       ND_PRINT("pt=0x%02x, pl=%d, pb=", EXTRACT_U_1((p - 2)), pl);
+                       ND_PRINT("pt=0x%02x, pl=%u, pb=", EXTRACT_U_1((p - 2)), pl);
                        while (pl-- > 0) {
                                ND_PRINT(" %02x", EXTRACT_U_1(p));
                                p++;
@@ -350,7 +367,7 @@ cdp_print_addr(netdissect_options *ndo,
                        ND_TCHECK_2(p);
                        if (p + 2 > endp)
                                goto trunc;
-                       ND_PRINT(", al=%d, a=", al);
+                       ND_PRINT(", al=%u, a=", al);
                        p += 2;
                        ND_TCHECK_LEN(p, al);
                        if (p + al > endp)
@@ -374,12 +391,12 @@ trunc:
 
 static int
 cdp_print_prefixes(netdissect_options *ndo,
-                  const u_char * p, int l)
+                  const u_char * p, u_int l)
 {
        if (l % 5)
                goto trunc;
 
-       ND_PRINT(" IPv4 Prefixes (%d):", l / 5);
+       ND_PRINT(" IPv4 Prefixes (%u):", l / 5);
 
        while (l > 0) {
                ND_PRINT(" %u.%u.%u.%u/%u",
@@ -396,11 +413,11 @@ trunc:
 }
 
 /* read in a <n>-byte number, MSB first
- * (of course this can handle max sizeof(long))
+ * (of course this can handle max sizeof(int))
  */
-static unsigned long cdp_get_number(const u_char * p, int l)
+static unsigned int cdp_get_number(const u_char * p, u_int l)
 {
-    unsigned long res=0;
+    unsigned int res=0;
     while( l>0 )
     {
        res = (res<<8) + EXTRACT_U_1(p);